期刊文献+
共找到680,249篇文章
< 1 2 250 >
每页显示 20 50 100
Thermal and Electrical Modelling of a CPV/T System Varying Its Configuration
1
作者 RENNO Carlo 《热科学学报:英文版》 SCIE EI CAS CSCD 2019年第1期123-132,共10页
In this paper,the main aim is the performances modelling from the electrical and thermal point of view of a concentrating photovoltaic and thermal (CPV/T)system in order to evaluate the primary energy and economic sav... In this paper,the main aim is the performances modelling from the electrical and thermal point of view of a concentrating photovoltaic and thermal (CPV/T)system in order to evaluate the primary energy and economic savings respect to a traditional system,when the same energy loads are satisfied.This study is realized by both varying the CPV/T system configuration and considering two different users.In particular,the point-focus (PF),and linear focus (LF)configurations of the CPV/T system are considered in order to match the residential user and hotel energy loads.The CPV/T system is sized adopting as input data:the Direct Normal Irradiance (DN1)modelled by an artificial neural network and the users'energy demands.In these hypotheses,the performances of the PF and LF systems are evaluated and then compared for the two users located in Southern Italy,in terms of electrical and thermal energy production,cells number,space occupied,energy and economic savings and CO2 emissions avoided.Finally,the PF system shows a lower simple pay-back and a higher primary energy saving,while the space occupied by a LF system results to be lower respect to the PF configuration. 展开更多
关键词 CPV/T system point-focus CONFIGURATION linear FOCUS CONFIGURATION THERMAL ANALYSIS electrical ANALYSIS primary energy SAVING economic ANALYSIS
Seismic reliability assessment of a steel moment-resisting frame with two different ductility levels using a cloud analysis approach 预览
2
作者 Seyed Bahram Beheshti Aval Amir Masoumi Verki 《地震工程与工程振动:英文版》 SCIE EI CSCD 2019年第1期171-185,共15页
A cloud method for generating percentile engineering demand parameter versus intensity measure(EDP-IM) curves of a structure subjected to a set of synthetic ground motions is presented. To this end, an ensemble of syn... A cloud method for generating percentile engineering demand parameter versus intensity measure(EDP-IM) curves of a structure subjected to a set of synthetic ground motions is presented. To this end, an ensemble of synthetic ground motions based on available real ones is generated. This is done by using attenuation relationships, duration and suitable Gutenberg-Richter relations attributed to the considered seismic hazard at a given site by estimating a suitable distribution of magnitude and site to source distance. The study aims to clarify the significance of the duration and frequency content on the seismic performance of structures, which were not considered in developing percentile incremental dynamic analysis(IDA) curves. The collapse probabilities of two steel moment-resisting frames with different ductility levels generated by IDA and the proposed cloud method are compared at different intensity levels. When compared with conventional IDA, the suggested cloud analysis(SCA) methodology with the same run number of dynamic analyses was able to develop response hazard curves that were more consistent with site-specific seismic hazards. Eliminating the need to find many real records by generating synthetic records consistent with site-specific seismic hazards from a few available recorded ground motions is another advantage of using this scheme over the IDA method. 展开更多
关键词 CLOUD ANALYSIS (CA) multiple-strip ANALYSIS (MSA) INCREMENTAL dynamic ANALYSIS (IDA) synthetic ground MOTIONS
在线阅读 下载PDF
Bioinformatics Based Therapeutic Effects of Sinomenium Acutum
3
作者 LI Yu-yan ZHENG Guang LIU Liang 《中国结合医学杂志:英文版》 SCIE CAS CSCD 2019年第2期122-130,共9页
Objective: To decipher the possible mechanisms of Sinomenium Acutum(SA) in treating diseases by a bioinformatics method. Methods: SA ingredients were searched according to Chinese Pharmacopoeia, Chinese Medicine Dicti... Objective: To decipher the possible mechanisms of Sinomenium Acutum(SA) in treating diseases by a bioinformatics method. Methods: SA ingredients were searched according to Chinese Pharmacopoeia, Chinese Medicine Dictionary and Traditional Chinese Medicines Database(TCMD). Active compounds and target proteins of SA were acquired through the Pubchem platform. Pathway, network and function analyses of SA were performed with ingenuity pathway analysis(IPA), a bioinformatics analysis platform. Disease, biofunction-target networks were established with Cytoscape. Results: Eighteen ingredients from SA were obtained. Seven active ingredients with 31 active target proteins were acquired according to PubChem Bioassay test. By IPA analysis, 277 canonical pathways belonging to 17 function categories were collected, 23 kinds of diseases, 21 categories bio-functions were obtained. Based on P value, calculated by IPA, the top 5 significant pathway of SA targets include phosphatidylinositol 3 kinase/Akt(PI3 K/Akt) signaling, prostate cancer signaling, macrophage migration inhibitory factor(MIF) regulation of innate immunity, Guanosine-binding protein coupled receptor(GPCR) signaling, and ataxia telangiectasia mutated protein(ATM) signaling. Disease and bio-function network analysis indicated that mitogen activated protein kinase 1(MAPK1), MAPK3, p65 nuclear factor κB(RELA), nuclear factor of κB inhibitor alpha(NFκBIA), interleukin 1β(IL-1β), prostaglandin G/H synthase 2(PTGS2) and tumor protein 53(TP53) were the critical targets in various diseases treated by SA. Conclusions: In the different view of target, pathway, disease and bio-function, inflammation was found to be a central theme in many chronic conditions. SA could be used not only as an anti-inflammatory agent, but also for the treatment of cancers, neurological diseases, psychological disorders and metabolic diseases. 展开更多
关键词 Sinomenium Acutum BIOINFORMATICS ANALYSIS INGENUITY PATHWAY ANALYSIS NETWORK PHARMACOLOGY
Progress on the development of DNA-mediated metal nanomaterials for environmental and biological analysis
4
作者 Jingtai Fu Zhuomin Zhang Gongke Li 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第2期285-291,共7页
Nowadays, DNA-mediated metal nanomaterials have received more and more attention due to their distinctive properties of easy synthesis, high stability and good biocompatibility. As a kind of efficient template to medi... Nowadays, DNA-mediated metal nanomaterials have received more and more attention due to their distinctive properties of easy synthesis, high stability and good biocompatibility. As a kind of efficient template to mediate the precise synthesis of metal nanomaterials, DNA can not only increase their recognition and biocompatibility, but also precisely control their morphology, structure and further analytical performance. DNA-mediated metal nanomaterials as ultrasensitive and selective probes have unique advantages for in situ rapid analysis of targets in complex samples. Herein, we reviewed the recent progress on synthesis strategies, morphologies, specific properties of DNA-mediated metal nanomaterials including nanoparticles and nanoclusters. Moreover, the applications of DNA-mediated metal nanomaterials to environmental and biological analysis were also summarized. Finally, the developing prospect of DNA-mediated metal nanomaterials in analytical chemistry was discussed and proposed. 展开更多
关键词 DNA-mediated METAL NANOMATERIALS METAL nanoparticles METAL nanoclusters ENVIRONMENTAL ANALYSIS Biological ANALYSIS
Rockfall seismic features analysis based on in situ tests:frequency, amplitude, and duration
5
作者 Liang FENG Veronica PAZZI +2 位作者 Emanuele INTRIERI Teresa GRACCHI Giovanni GIGLI 《山地科学学报:英文版》 SCIE CSCD 2019年第5期955-973,共19页
In the seismic event classification,determining the seismic features of rockfall is significantly important for the automatic classification of seismic events because of the huge amount of raw data recorded by seismic... In the seismic event classification,determining the seismic features of rockfall is significantly important for the automatic classification of seismic events because of the huge amount of raw data recorded by seismic stations in continuous monitoring. At the same time, the rockfall seismic features are still not completely understood.This study concentrates on the rockfall frequency content, amplitude(ground velocity), seismic waveform and duration analysis, of an artificial rockfall test at Torgiovannetto(a former quarry in Central Italy). A total of 90 blocks were released in the test, and their seismic signals and moving trajectories were recorded by four tri-axial seismic stations and four cameras, respectively. In the analysis processing,all the artificial rockfall signal traces were cut separately and the seismic features were extracted individually and automatically. In this study, the relationships between a) frequency content and impacted materials, b) frequency content and the distance between block releasing position and seismic station(source-receiver distance) were discussed. As a result, we found that the frequency content of rockfall focuses on 10-60 Hz and 80-90 Hz within a source-receiver distance of 200 m, and it is well correlated with impacted material and source-receiver distance. To evaluate the difference between earthquake and rockfall, 23 clear earthquake signals recorded in a seven month-long continuous seismic monitoring, carried out with the four seismic stations, were picked out, according to the Italian national earthquakes database(INGV). On these traces we performed the same analysis as in the artificial rockfall traces, and two parameters were defined to separate rockfall events from earthquake noise. The first one, the amplitude ratio, is related to the amplitude variation of rockfall between two stations and is greater than that of earthquakes, because of the higher attenuation occurring for rockfall events, which consists in high frequencies whereas for earthquakes it consists 展开更多
关键词 ROCKFALL SEISMIC noise ANALYSIS Fourier TRANSFORM SEISMIC events classification Time-series ANALYSIS SEISMIC monitoring
Pressure Transient Analysis of an Intersecting Rollover Faulted Crest Boundary in Niger Delta Oil Field 预览
6
作者 K.K.Ihekoronye I.P.Nwosu 《长江油气(英文版)》 2019年第2期125-143,共19页
Pressure transient analysis has been extensively applied to detect anomalies in a reservoir system.These anomalies may be presented in the form of an intersection of the crestal and the antithetic fault associated wit... Pressure transient analysis has been extensively applied to detect anomalies in a reservoir system.These anomalies may be presented in the form of an intersection of the crestal and the antithetic fault associated with a growth fault.Interpretation of this fault can only be achieved through the use of pressure transient analysis.The objective of the research work is to analyze and test the faulted crest,depth of the anticline structure and examine the near well bore conditions in order to evaluate whether the well productivity is governed by wellbore effects(skin effects+well bore effect)or the reservoir at large.A case study of a well in the Niger delta is considered with a series of build up test carried out in two intervals of both upper and lower gauge readings.In this study,a computer aided design which uses a pressure derivative approach is used in this work to match the pressure derivative of an intersecting fault(angle)model to the field data,and the model assumes the characteristics of the reservoir.Based on the result of the interpreted data,simulation is done by using a non linear regression method(least square).The simulated data interpreted are achieved through the regression coefficient which provides a quantitative measure of the agreement between field data and the model.In conclusion,the best cases are taken from all the results and a nodal analysis is performed to diagnose the inflow performance of the well through the transient analysis in order to optimize the recovery of the oilfield. 展开更多
关键词 PRESSURE TRANSIENT ANALYSIS Fault NODAL ANALYSIS Wellbore Effect
在线阅读 免费下载
Differences between Contrastive Analysis and Error Analysis on English Writing for Chinese EFL learners 预览
7
作者 卢伟 《海外英语》 2019年第8期271-272,共2页
With the increasing importance of English writing, how to improve students’writing ability is a big challenge. Contrastive analysis and error analysis are two popular approaches to error correction in English writing... With the increasing importance of English writing, how to improve students’writing ability is a big challenge. Contrastive analysis and error analysis are two popular approaches to error correction in English writing. This paper is going to compare the differences between contrastive analysis and error analysis, in English writing for Chinese EFL learners, from perspectives, such as, English writing purpose, English writing errors and attitude towards English writing. After that, some better suggestions will be given at the end of the paper. 展开更多
关键词 CONTRASTIVE ANALYSIS Error ANALYSIS Chinese EFL LEARNERS Writing
在线阅读 免费下载
Analysis and design of axially loaded piles in rock 预览
8
作者 C.M.Haberfield A.L.E.Lochaden 《岩石力学与岩土工程学报:英文版》 CSCD 2019年第3期535-548,共14页
Despite significant advancements in in situ test techniques,construction practices,understanding of rock joint and rock mass behaviours,and numerical analysis methods,the design of bored concrete cast-insitu piles in ... Despite significant advancements in in situ test techniques,construction practices,understanding of rock joint and rock mass behaviours,and numerical analysis methods,the design of bored concrete cast-insitu piles in rock is still largely based on the assessment of bearing capacity.However,for many of the rock conditions encountered,the bearing capacity of piles is a nebulous concept and a figment of the designer’s imagination.Even if it can be reasonably quantified,it has little,if any,significance to the performance of a pile in rock.The load carrying capacity of even low strength rock(in most situations)is far in excess of the strength of the structure(for example,a building column)transmitting the load.Unsatisfactory performance of a pile in rock is usually a displacement issue and is a function of rock mass stiffness rather than rock mass strength.In addition,poor pile performance is much more likely to result from poor construction practices than excessive displacement of the rock mass.Exceptions occur for footings that are undermined,or where unfavourable structure in the rock allows movement towards a free surface to occur.Standards,codes of practices,reference books and other sources of design information should focus foundation design in rock on displacement rather than strength performance.Ground investigations should measure rock mass stiffness and defect properties,as well as intact rock strength.This paper summarises the fundamental concepts relating to performance of piles in rock and provides a basis for displacement focused design of piles in rock.It also presents comments relating to how piles are modelled in widely used commercial finite element software for soil-structure interaction analysis,within the context of the back-analysis of a pile load test,and proposes recommendations for pile analysis and design. 展开更多
关键词 PILE design PILE ANALYSIS PILE load test FINITE element ANALYSIS
在线阅读 下载PDF
Slope reliability and back analysis of failure with geotechnical parameters estimated using Bayesian inference 预览
9
作者 Luis-Fernando Contreras Edwin T.Brown 《岩石力学与岩土工程学报:英文版》 CSCD 2019年第3期628-643,共16页
A Bayesian approach is proposed for the inference of the geotechnical parameters used in slope design.The methodology involves the construction of posterior probability distributions that combine prior information on ... A Bayesian approach is proposed for the inference of the geotechnical parameters used in slope design.The methodology involves the construction of posterior probability distributions that combine prior information on the parameter values with typical data from laboratory tests and site investigations used in design.The posterior distributions are often complex,multidimensional functions whose analysis requires the use of Markov chain Monte Carlo(MCMC)methods.These procedures are used to draw representative samples of the parameters investigated,providing information on their best estimate values,variability and correlations.The paper describes the methodology to define the posterior distributions of the input parameters for slope design and the use of these results for evaluation of the reliability of a slope with the first order reliability method(FORM).The reliability analysis corresponds to a forward stability analysis of the slope where the factor of safety(FS)is calculated with a surrogate model from the more likely values of the input parameters.The Bayesian model is also used to update the estimation of the input parameters based on the back analysis of slope failure.In this case,the condition FS?1 is treated as a data point that is compared with the model prediction of FS.The analysis requires a sufficient number of observations of failure to outbalance the effect of the initial input parameters.The parameters are updated according to their uncertainty,which is determined by the amount of data supporting them.The methodology is illustrated with an example of a rock slope characterised with a Hoek-Brown rock mass strength.The example is used to highlight the advantages of using Bayesian methods for the slope reliability analysis and to show the effects of data support on the results of the updating process from back analysis of failure. 展开更多
关键词 BAYESIAN ANALYSIS HOEK-BROWN CRITERION SLOPE reliability Back ANALYSIS of FAILURE
在线阅读 下载PDF
Two methodological approaches to assess the seismic vulnerability of masonry bridges
10
作者 Diego Maria Barbieri 《交通运输工程学报(英文版)》 CSCD 2019年第1期49-64,共16页
This work describes the seismic vulnerability assessment of a railway masonry arch bridge.Its conservation state is initially investigated by means of a thorough field and laboratory test campaign, comprising destruct... This work describes the seismic vulnerability assessment of a railway masonry arch bridge.Its conservation state is initially investigated by means of a thorough field and laboratory test campaign, comprising destructive and non-destructive tests. Two different methods are used to evaluate the bridge seismic vulnerability. The first method adopts a deterministic approach and corresponds to a single non-linear static analysis, performed as described in the Eurocodes. The second method employs a probabilistic approach and considers the variability of the involved mechanical parameters(structure geometry and properties of the building materials) and seismic parameters(intensity of the action and site conditions). This method associates the probabilistic values of ground acceleration exceedance to the estimated seismic vulnerability. This is shown by means of fragility curves, which allow to take into consideration the uncertainty of the various components involved in the definition of the seismic vulnerability and display the seismic damage scenarios. Currently no code requires to perform this calculation procedure. In addition,this work compares the values of masonry mechanical properties specified in the Eurocodes with those obtained in an extensive investigation campaign involving more than one hundred masonry bridges. Compressive strength and longitudinal elasticity modulus are the relevant mechanical parameters investigated. The outcomes of this research can contribute to the development of a more efficient maintenance system of the masonry bridges belonging to the railway network. This has an important role when it comes to establishing the priority order of assets intervention. 展开更多
关键词 Railway MASONRY ARCH BRIDGE BRIDGE maintenance and conservation MASONRY mechanical parameters NON-LINEAR static ANALYSIS Seismic FRAGILITY Finite element ANALYSIS
Establishment of HPLC Fingerprint, Cluster Analysis and Principle Component Analysis of Citri Reticulatae Pericarpium Viride 预览
11
作者 Beibei JIN Xiangping PEI Huizhen LIANG 《药用植物研究(英文版)》 2019年第1期69-73,共5页
[Objectives] This study aimed to establish HPLC fingerprint and conduct cluster analysis and principle component analysis for Citri Reticulatae Pericarpium Viride. [Methods] Using the HPLC method, the determination wa... [Objectives] This study aimed to establish HPLC fingerprint and conduct cluster analysis and principle component analysis for Citri Reticulatae Pericarpium Viride. [Methods] Using the HPLC method, the determination was performed on XSelect&#x00AE;HSS T3-C18 column with mobile phase of acetonitrile-0.5% acetic acid solution(gradient elution) at the flow rate of 1.0 mL/min. The detection wavelength was 360 nm. The column temperature was 25℃. The sample size was 10 μL. With peak of hesperidin as the reference, HPLC fingerprints of 10 batches of Citri Reticulatae Pericarpium Viride were determined. The similarity of the 10 batches of samples was evaluated by Similarity Evaluation System for Chromatographic Fingerprint of TCM(2012 edition) to determine the common peaks. Cluster analysis and principal component analysis were performed by using SPSS 17.0 statistical software. [Results] The HPLC fingerprints of the 10 batches of medicinal materials had total 11 common peaks, and the similarity was 0.919-1.000, indicating that the chemical composition of the 10 batches of medicinal materials was consistent. There were 11 common components in the 10 batches of medicinal materials, but their contents were different. When the Euclidean distance was 20, the 10 batches of samples were divided into two categories, S4 in the first category, and the others in the second one. When the Euclidean distance was 5, the second category could be further divided into two sub-categories, S1 and S10 in one sub-category, and S2, S3, S5, S6, S7, S8 and S9 in the other one. The principle component analysis showed that cumulative contribution rate of the two main component factors was 92.797%, and the comprehensive score of S7 was the highest with the best quality. [Conclusions] The results of HPLC fingerprinting, cluster analysis and principle component analysis can provide reference for the quality control of Citri Reticulatae Pericarpium Viride. 展开更多
关键词 Citri Reticulatae Pericarpium Viride HPLC FINGERPRINT CLUSTER ANALYSIS PRINCIPLE COMPONENT ANALYSIS
在线阅读 免费下载
Estimation of peak runoff and frequency in an ungauged stream of a forested watershed for flood hazard mapping 预览
12
作者 Refik Karagul Tarik Citgez 《林业研究:英文版》 CAS CSCD 2019年第2期555-564,共10页
frequencies.The aim of this research was to determine the measures needed to protect the towns and villages from this type of damage.Daily total precipitation data for 1975–2010 were analysed,and rainfall-runoff mode... frequencies.The aim of this research was to determine the measures needed to protect the towns and villages from this type of damage.Daily total precipitation data for 1975–2010 were analysed,and rainfall-runoff models developed to estimate the potential yearly maximum discharge from each stream of sub-watersheds dominated by forests and/or agriculture.This was then calculated for different frequencies of the yearly maximum discharge.Flood analysis and mapping was modified via the one-dimensional Hydrologic Engineering Centers-River Analysis System software to produce potential maximum discharge and geometric data for Kaynasli Creek.As the main creek of the sub-watershed,its crosssection was shown to be insufficient and incapable of containing the maximum discharge at the 100-year frequency presumed for the watershed,and subsequently was seen as having a high level of casualty risk.It was concluded that the one dimensional model could be useful,but 2D models were more suitable for these types of watersheds. 展开更多
关键词 Flood FREQUENCY ANALYSIS FLOODPLAIN MAPPING Flow simulation Hydrologic Engineering Centers-River ANALYSIS System(HEC-RAS) Soil Conservation Service Curve Number(SCS-CN)
在线阅读 下载PDF
Using uncertainty and sensitivity analysis for finding the best rainfall-runoff model in mountainous watersheds(Case study: the Navrood watershed in Iran)
13
作者 Arash ADIB Morteza LOTFIRAD Ali HAGHIGHI 《山地科学学报:英文版》 SCIE CSCD 2019年第3期529-541,共13页
In watersheds that have not sufficient meteorological and hydrometric data for simulating rainfall-runoff events, using geomorphologic and geomorphoclimatic characteristics of watershed is a conventional method for th... In watersheds that have not sufficient meteorological and hydrometric data for simulating rainfall-runoff events, using geomorphologic and geomorphoclimatic characteristics of watershed is a conventional method for the simulation. A number of rainfall-runoff models utilize these characteristics such as Nash-IUH, Clark-IUH, Geomorphologic Instantaneous Unit Hydrograph(GIUH), Geomorphoclimatic Instantaneous Unit Hydrograph(GcIUH), GIUH-based Nash(GIUH-Nash) and GcIUH-based Clark(GcIUH-Clark). But all these models are not appropriate for mountainous watersheds. Therefore, the objective of this study is to select the best of them for the simulation. The procedure of this study is: a) selecting appropriate rainfall-runoff events for calibration and validation of six hybrid models, b) distinguishing the best model based on different performance criteria(Percentage Error in Volume(PEV);Percentage Error in Peak(PEP);Percentage Error in Time to Peak(PETP);Root Mean Square Error(RMSE) and Nash-Sutcliffe model efficiency coefficient(ENS)), c) Sensitivity analysis for determination of the most effective parameter at each model, d) Uncertainty determination of different parameters in each model and confirmation of the obtained results by application of the performance criteria. For application of this procedure, the Navrood watershed in the north of Iran as a mountainous watershed has been considered. The results showed that the ClarkIUH and GcIUH-Clark are suitable models for simulation of flood hydrographs, while other models cannot simulate flood hydrographs appropriately. The sensitivity analysis shows that the most sensitive parameters are the infiltration constant rate and time of concentration in the Clark-IUH model. Also, the most sensitive parameters include the infiltration constant rate and storage coefficient in the GcIUHClark model. The Clark-IUH and GcIUH-Clark models are more sensitive to their parameters. The Latin Hypercube Sampling(LHS) on Monte Carlo(MC) simulation method was used for evaluation of uncertai 展开更多
关键词 Sensitivity ANALYSIS UNCERTAINTY ANALYSIS Clark-IUH GcIUH-Clark GIUH-Nash Monte Carlo simulation method
Identification and Prediction of Interdisciplinary Research Topics: A Study Based on the Concept Lattice Theory
14
作者 Haiyun Xu Chao Wang +1 位作者 Kun Dong Zenghui Yue 《数据与情报科学学报:英文版》 CSCD 2019年第1期60-88,共29页
Purpose: Formal concept analysis (FCA) and concept lattice theory (CLT) are introduced for constructing a network of IDR topics and for evaluating their effectiveness for knowledge structure exploration.Design/methodo... Purpose: Formal concept analysis (FCA) and concept lattice theory (CLT) are introduced for constructing a network of IDR topics and for evaluating their effectiveness for knowledge structure exploration.Design/methodology/approach: We introduced the theory and applications of FCA and CLT, and then proposed a method for interdisciplinary knowledge discovery based on CLT. As an example of empirical analysis, interdisciplinary research (IDR) topics in Information & Library Science (LIS) and Medical Informatics, and in LIS and Geography-Physical, were utilized as empirical fields. Subsequently, we carried out a comparative analysis with two other IDR topic recognition methods.Findings: The CLT approach is suitable for IDR topic identification and predictions.Research limitations: IDR topic recognition based on the CLT is not sensitive to the interdisciplinarity of topic terms, since the data can only reflect whether there is a relationship between the discipline and the topic terms. Moreover, the CLT cannot clearly represent a large amounts of concepts.Practical implications: A deeper understanding of the IDR topics was obtained as the structural and hierarchical relationships between them were identified, which can help to get more precise identification and prediction to IDR topics.Originality/value: IDR topics identification based on CLT have performed well and this theory has several advantages for identifying and predicting IDR topics. First, in a concept lattice, there is a partial order relation between interconnected nodes, and consequently, a complete concept lattice can present hierarchical properties. Second, clustering analysis of IDR topics based on concept lattices can yield clusters that highlight the essential knowledge features and help display the semantic relationship between different IDR topics. Furthermore, the Hasse diagram automatically displays all the IDR topics associated with the different disciplines, thus forming clusters of specific concepts and visually retaining and presenting the ass 展开更多
关键词 INTERDISCIPLINARY research IDR TOPICS CONCEPT lattice FORMAL ANALYSIS Cluster ANALYSIS
Characterization of machine tools and measurement system for micromilling 预览
15
作者 Andrea Abeni Matteo Lancini Aldo Attansio 《纳米技术与精密工程(英文)》 CAS CSCD 2019年第1期23-28,共6页
Technological progress has led to increased demand for small components with tiny features,which cannot be achieved through conventional machining.Industrial application of processes based on microcutting is limited b... Technological progress has led to increased demand for small components with tiny features,which cannot be achieved through conventional machining.Industrial application of processes based on microcutting is limited by some issues concerning the geometrical scale.The process performance is significantly affected by millingmachine,tool holder,tool,workpiecematerialmicrostructure,workpiece fixtures,and process parameters.At present,an ultimate micromachining assessment procedure is not available.This study aims to propose and conduct an experiment on a testing procedure for micromilling.The set up to be implemented and the output to be considered are defined and described.Threemajor stages are identified:estimation of the effective bandwidth of the load cell–tool holder system,the millingmachine natural frequency measurement,and micromilling test execution.The entire procedure is performed,and its robustness is demonstrated. 展开更多
关键词 MICROMILLING Machine TOOL performance test TOOL run-out FORCE ANALYSIS MODAL ANALYSIS
在线阅读 下载PDF
A novel approach to correlate heat transfer and pressure fluctuation in gas-solid spouted bed
16
作者 P.K. Mollick P.S. Goswamib +2 位作者 M. Krishnana P.K. Vijayanc A.B. Panditd 《中国颗粒学报:英文版》 SCIE EI CAS CSCD 2019年第1期26-34,共9页
Statistical analysis of pressure fluctuations in spouted beds has been used as a well-established diagnostic tool to determine bed and flow characteristics because of its smooth operation. However, in many recent and ... Statistical analysis of pressure fluctuations in spouted beds has been used as a well-established diagnostic tool to determine bed and flow characteristics because of its smooth operation. However, in many recent and conventional applications of spouted beds such as drying, coal gasification, catalytic conversion, biomass treatment, and chemical vapor deposition, direct estimation of the heat transfer rate from the solid bed to the gas or vice versa has proven to be difficult. A variance and spectral analysis of pressure fluctuation is extended here to characterize the heat transfer phenomena in a spouted bed. In the present study, zirconia and alumina were used as the bed materials, and argon and nitrogen were used as the spouting gases. Experiments were conducted at various heating rates for different superficial gas velocities for a range of temperatures up to 300 °C. Significant changes in the gas density and viscosity with different extents of heat transfer were observed to affect the momentum diffusivity and gas–particle interaction, which in turn led to local pressure fluctuations, causing the bed to behave differently. In the present work, a novel approach is proposed to establish a link between local pressure fluctuation and the extent of heat transfer in the bed. This method shows potential for correlation of the statistics of pressure fluctuation with the thermal properties of individual solids and gases. Thus, the technique can be extended to many industrial applications for the indirect estimation of the extent of heat transfer and prediction of unknown thermal properties of products in solids or gases. 展开更多
关键词 Spouted BED Heat transfer Pressure FLUCTUATION STATISTICAL ANALYSIS Power spectral density ANALYSIS Thermal properties
Analysis of the autophagy gene expression profile of pancreatic cancer based on autophagy-related protein microtubule-associated protein 1A/1B-light chain 3 预览
17
作者 Yan-Hui Yang Yu-Xiang Zhang +3 位作者 Yang Gui Jiang-Bo Liu Jun-Jun Sun Hua Fan 《世界胃肠病学杂志:英文版》 SCIE CAS 2019年第17期2086-2098,共13页
BACKGROUND Pancreatic cancer is a highly invasive malignant tumor. Expression levels of the autophagy-related protein microtubule-associated protein 1A/1B-light chain 3 (LC3) and perineural invasion (PNI) are closely ... BACKGROUND Pancreatic cancer is a highly invasive malignant tumor. Expression levels of the autophagy-related protein microtubule-associated protein 1A/1B-light chain 3 (LC3) and perineural invasion (PNI) are closely related to its occurrence and development. Our previous results showed that the high expression of LC3 was positively correlated with PNI in the patients with pancreatic cancer. In this study, we further searched for differential genes involved in autophagy of pancreatic cancer by gene expression profiling and analyzed their biological functions in pancreatic cancer, which provides a theoretical basis for elucidating the pathophysiological mechanism of autophagy in pancreatic cancer and PNI. AIM To identify differentially expressed genes involved in pancreatic cancer autophagy and explore the pathogenesis at the molecular level. METHODS Two sets of gene expression profiles of pancreatic cancer/normal tissue (GSE16515 and GSE15471) were collected from the Gene Expression Omnibus. Significance analysis of microarrays algorithm was used to screen differentially expressed genes related to pancreatic cancer. Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were used to analyze the functional enrichment of the differentially expressed genes. Protein interaction data containing only differentially expressed genes was downloaded from String database and screened. Module mining was carried out by Cytoscape software and ClusterOne plug-in. The interaction relationship between the modules was analyzed and the pivot nodes between the functional modules were determined according to the information of the functional modules and the data of reliable protein interaction network.RESULTS Based on the above two data sets of pancreatic tissue total gene expression, 6098 and 12928 differentially expressed genes were obtained by analysis of genes with higher phenotypic correlation. After extracting the intersection of the two differential gene sets, 4870 genes were determined 展开更多
关键词 Pancreatic cancer Autophagy-related PROTEIN microtubule-associated PROTEIN 1A/1B-light chain 3 Perineural invasion Gene Ontology ANALYSIS Kyoto ENCYCLOPEDIA of Genes and Genomes pathway ANALYSIS Ubiquitin C
在线阅读 免费下载
MicroRNA changes of bone marrow-derived mesenchymal stem cells differentiated into neuronallike cells by Schwann cell-conditioned medium 预览
18
作者 Zhi-Jian Wei Bao-You Fan +9 位作者 Yang Liu Han Ding Hao-Shuai Tang Da-Yu Pan Jia-Xiao Shi Peng-Yuan Zheng Hong-Yu Shi Heng Wu Ang Li Shi-Qing Feng 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第8期1462-1469,共8页
Bone marrow-derived mesenchymal stem cells differentiate into neurons under the induction of Schwann cells. However, key microRNAs and related pathways for differentiation remain unclear. This study screened and ident... Bone marrow-derived mesenchymal stem cells differentiate into neurons under the induction of Schwann cells. However, key microRNAs and related pathways for differentiation remain unclear. This study screened and identified differentially expressed microRNAs in bone marrow- derived mesenchymal stem cells induced by Schwann cell-conditioned medium, and explored targets and related pathways involved in their differentiation into neuronal-like cells. Primary bone marrow-derived mesenchymal stem cells were isolated from femoral and tibial bones, while primary Schwann cells were isolated from bilateral saphenous nerves. Bone marrow-derived mesenchymal stem cells were cultured in unconditioned (control group) and Schwann cell-conditioned medium (bone marrow-derived mesenchymal stem cell + Schwann cell group). Neuronal differentiation of bone marrow-derived mesenchymal stem cells induced by Schwann cell-conditioned medium was observed by time-lapse imaging. Upon induction, the morphology of bone marrow-derived mesencaymal stem cells changed into a neural shape with neurites. Results of quantitative reverse transcription-polymerase chain reaction revealed that nestin mRNA expression was upregulated from 1 to 3 days and downregulated from 3 to 7 days in the bone marrow-derived mesenchymal stem cell + Schwann cell group. Compared with the control group, microtubule-associated protein 2 mRNA expression gradually increased from 1 to 7 days in the bone marrow-derived mesenchymal stem cell + Schwann cell group. After 7 days of induction, microRNA analysis iden:ified 83 significantly differentially expressed microRNAs between the two groups. Gene Ontology analysis indicated enrichment of microRNA target genes for neuronal projection development, regulation of axonogenesis, and positive regulation of cell proliferation. Kyoto Encyclopedia of Genes and Genomes pathway analysis demonstrated that Hippo, Wnt, transforming growth factor-beta, and Hedgehog signaling pathv/ays were potentially associated with neural differentiation of b 展开更多
关键词 nerve REGENERATION MICRORNA analysis bone marrow-derived mesenchymal stem cells: Schwann CELLS neuronal-like CELLS neuronal differentiation Gene Ontology analysis Hippo SIGNALING PATHWAY Wnt SIGNALING PATHWAY transforming growth FACTOR-BETA SIGNALING PATHWAY Hedgehog SIGNALING PATHWAY neural REGENERATION
在线阅读 下载PDF
The interactions between surface Kuroshio transport and the eddy field east of Taiwan using satellite altimeter data 预览
19
作者 Huizan Wang Quanhong Liu +2 位作者 Hengqian Yan Bo Song Weimin Zhang 《海洋学报:英文版》 SCIE CAS CSCD 2019年第4期116-125,共10页
Based on the daily sea surface height and absolute geostrophic velocity data from 1993 to 2015 provided by the AVISO Center of French Space Agency,the surface Kuroshio transport east of Taiwan and its adjacent eddy fi... Based on the daily sea surface height and absolute geostrophic velocity data from 1993 to 2015 provided by the AVISO Center of French Space Agency,the surface Kuroshio transport east of Taiwan and its adjacent eddy field(sea surface height anomaly)were analyzed.Four main periods of the surface Kuroshio transport and eddy field east of Taiwan were obtained,which were used to reveal their interactions.The main conclusions are as follows:(1)Based on the wavelet analysis,the surface Kuroshio transport east of Taiwan and its nearby eddy field showed significant seasonal,annual and interannual periods.In addition to the obvious periods of 182 days(0.5 year)and 365 days(1 year),there were also more obvious periods of about 860 days(2.35 years)and 2 472 days(6.8 years)for the surface Kuroshio transport.There were also four more obvious periods corresponding to the eddy field of 200 days(0.55 year),374 days(1 year),889 days(2.43 years)and 2 374 days(6.5 years),although there were latitudinal variations.(2)Based on both the correlation and causal analysis,the correlation between the surface Kuroshio transport and the nearby eddy field over the above four periods was analyzed,and different Kuroshioeddy interactions,with period and latitudinal variability,were revealed. 展开更多
关键词 wavelet ANALYSIS CAUSAL ANALYSIS KUROSHIO EAST of TAIWAN correlation sea level ANOMALY
在线阅读 下载PDF
Research on emotion space of film and television scene images based on subjective perception
20
作者 Su Zhibin Qian Yahong +1 位作者 Gu Yu Ren Hui 《中国邮电高校学报:英文版》 EI CSCD 2019年第1期75-81,104共8页
The premise of image emotion recognition is to determine its representative emotional adjectives and establish the quantifiable emotion space. In this paper, focusing on aroused emotion from film and television(TV) sc... The premise of image emotion recognition is to determine its representative emotional adjectives and establish the quantifiable emotion space. In this paper, focusing on aroused emotion from film and television(TV) scene images, a method of selecting emotional adjectives and establishing the emotion space based on subjective perception experiment is proposed. Firstly, a special data set about film and TV scene images was established and a set of initial emotional adjectives was collected. Then the subjective perception experiment was designed to let subjects to evaluate the affection of all the initial adjectives during watching these scene images. Then the method of principal basis analysis was used for variable selection. Finally, the factor analysis was applied to accomplish the second dimension reduction to form a 5-dimensional(5 D) orthogonal emotion space. The optimized emotion space can explain more than 94% of original emotional adjectives, which greatly reduces the dimension of emotional adjectives and lays a foundation for the further research on image content and emotion recognition. 展开更多
关键词 film and TELEVISION SCENE images SUBJECTIVE PERCEPTION EMOTION space principal basis ANALYSIS factor ANALYSIS
上一页 1 2 250 下一页 到第
使用帮助 返回顶部 意见反馈