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Cyclomatic Complexity-Based Encapsulation, Data Hiding, and Separation of Concerns 认领
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作者 Charles W. Butler Thomas J. McCabe 《软件工程与应用(英文)》 2021年第1期44-66,共23页
<div style="text-align:justify;"> <span style="font-family:Verdana;">Three design principles are prominent in software development-encapsulation, data hiding, and separation of concerns... <div style="text-align:justify;"> <span style="font-family:Verdana;">Three design principles are prominent in software development-encapsulation, data hiding, and separation of concerns. These principles are used as subjective quality criteria for both procedural and object-oriented applications. The purpose of research is to quantify encapsulation, data hiding, and separation of concerns is quantified using cyclomatic-based metrics. As a result of this research, the derived design metrics, coefficient of encapsulation, coefficient of data hiding, and coefficient of separation of concerns, are defined and applied to production software indicating whether the software has low or high encapsulation, data hiding, and separation of concerns.</span> </div> 展开更多
关键词 Object-Oriented Design Methods RELIABILITY Complexity Measures Software Design ENCAPSULATION Information Hiding Separation of Concerns McCabe Metrics Coefficient of Encapsulation Coefficient of Data Hiding Coefficient of Separation of Concerns
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文章速递Tailoring Morphology of PVDF-HFP Membrane via One-step Reactive Vapor Induced Phase Separation for Efficient Oil-Water Separation 认领
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作者 Peng Huo Cheng-Tang Zhong Xiao-Peng Xiong 《高分子科学:英文版》 SCIE CAS CSCD 2021年第5期610-619,I0007,共11页
Poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)receives increasing attention in membrane separation field based on its advantages such as high mechanical strength,thermal and chemical stability.However,cont... Poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)receives increasing attention in membrane separation field based on its advantages such as high mechanical strength,thermal and chemical stability.However,controlling the microporous structure is still challenging.In this work,we attempted to tailor the morphology of PVDF-HFP membrane via a one-step reactive vapor induced phase separation method.Namely,PVDF-HFP was dissolved in a volatile solvent and then was cast in an ammonia water vapor atmosphere.After complete evaporation of solvent,membranes with adjustable porous structure were prepared,and the microstructures of the membranes were analyzed by scanning electron microscopy,Fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy and X-ray diffraction characterizations.Based on the results,a mechanism of dehydrofluorination induced cross-linking of PVDF-HFP has been suggested to understand the morphology tailoring.To our knowledge,this is the first report of one-step reactive vapor induced phase separation strategy to tailor morphology of PVDF-HFP membrane.In addition,the membranes prepared in the ammonia water vapor exhibited enhanced mechanical strength and achieved satisfactory separation efficiency for water-in-oil emulsions,suggesting promising potential. 展开更多
关键词 PVDF-HFP Membrane Tailoring Vapor induced phase separation Oil-water separation
Optimization and verification of wind tunnel free-flight similarity law for separation of cluster munition 认领
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作者 Fei XUE Jun TANG +4 位作者 Huaqiang WANG Zenghui JIANG Yuchao WANG Han QIN Peng BAI 《中国航空学报:英文版》 SCIE EI CAS CSCD 2021年第3期61-70,共10页
In view of the separation form of the separator from the back of the carrier upward and from the side of the carrier outward, separation-safety research is carried out by taking the separation of a cluster munition as... In view of the separation form of the separator from the back of the carrier upward and from the side of the carrier outward, separation-safety research is carried out by taking the separation of a cluster munition as an example. In previous wind tunnel free-flight tests, the similarity law of vertical, downward, moving submunition was used to design submunitions at different positions in different initial-velocity directions, which resulted in large discrepancies between wind tunnel test results and real flight. In a wind tunnel test, each submunition has an independent time-reduction ratio with respect to the dispenser. Even if the separation trajectory of a single submunition is accurate, there will be errors in the position of each submunition at a given time. Therefore, it is necessary to determine the time-reduction ratio between submunitions, and to modify the test results later. In order to ensure the accuracy of wind tunnel test results, the similarity law of a freeflight test in a wind tunnel is derived in this paper. The time-correction scheme to ensure motion similarity between submunitions is solved. Numerical simulation is used to simulate the separation of a wind tunnel test and real aircraft, and the motion parameters of different submunitions are solved. The results show that the new similarity laws derived for different types of submunitions can greatly reduce the errors caused by previous similarity laws. In addition to the case for the separation of a cluster munition, the similarity law can also be applied to the free-flight test design of wind tunnels for vertical separation and horizontal separation of other kinds of aircraft. 展开更多
关键词 Cluster munition Ejection separation Free-flight wind tunnel test Multi-body separation Similarity-law derivation
Multi-scale separation of aeromagnetic abnormality based on dual-tree complex wavelet 认领
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作者 GONG Mingxu ZENG Zhaofa +1 位作者 ZHANG Jianmin JIANG Dandan 《世界地质:英文版》 2021年第1期49-57,共9页
Bit-field separation is an important part of gravity and magnetic data processing.In order to extract different levels of anomaly information better,this paper introduces the dual-tree complex wavelet multi-scale sepa... Bit-field separation is an important part of gravity and magnetic data processing.In order to extract different levels of anomaly information better,this paper introduces the dual-tree complex wavelet multi-scale separation to the processing of bit-field data firstly and uses the geological model of different buried depth to ve-rify its feasibility.Finally,the dual-tree complex wavelet is applied to the aeromagnetic anomaly in Jinchuan copper nickel mining area.The results show that the method can effectively separate the anomaly information of different scales and analyze the output results with relevant geological data. 展开更多
关键词 aeromagnetic abnormality multi-scale separation bit-field separation dual-tree complex wavelet Jinchuan
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Oily Water Treatment by Ceramic Membrane: Modeling and Simulation 认领
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作者 Adriana Barbosa da Costa Pereira Hortência Luma Fernandes Magalhães +5 位作者 Leonardo Pereira de Lucena Silva Cristiane Arcoverde Passos Ricardo Soares Gomez Balbina Raquel de Brito Correia Severino Rodrigues de Farias Neto Antonio Gilson Barbosa de Lima 《流体动力学(英文)》 2021年第1期1-19,共19页
The separation process of oily water using membranes has attracted the attention of researchers and engineers. The greater problem in the use of membrane separation process is the reduction in permeate flux due to clo... The separation process of oily water using membranes has attracted the attention of researchers and engineers. The greater problem in the use of membrane separation process is the reduction in permeate flux due to clogged pores by oil deposition inside the membrane or by the effect of the concentration polarization. For this purpose, a theoretical study of a water/oil separation module was performed. This device consists of a tubular ceramic membrane provided with a rectangular inlet section. Numerical simulations were performed using Ansys CFX software to solve the mass and momentum conservation equations in the fluid and porous domains. Here was adopted the RNG k-ε turbulence model. The effect of the membrane porosity and the inlet velocity of the fluid mixture on the two-phase flow behavior inside the separation module were evaluated. Results of the volumetric fraction, velocity and pressure fields of the oil and water phases are presented and analyzed. The results indicate a higher oil concentration within the membrane for the cases of higher porosity, and that the inlet fluid mixture velocity does not substantially affect the velocity profile within the separation module. It is found that the maximum separation efficiency of the module was obtained with feed velocity of 40 m/s and membrane porosity of 0.44. 展开更多
关键词 Ceramic Membranes Separation Process Computational Fluid Dynamics CFX
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Analysis of CO<sub>2</sub>Pressure Swing Adsorption Simulation by Considering the Transport Phenomena in the Adsorber 认领
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作者 Takehiro Esaki Hideaki Kuronuma Noriyuki Kobayashi 《材料科学与化学工程(英文)》 2021年第3期39-54,共16页
This study focused on CO<sub>2</sub> separation technology with adsorption. This paper describes the analysis carried out by a CO<sub>2</sub> pressure swing adsorption simulation to scale up th... This study focused on CO<sub>2</sub> separation technology with adsorption. This paper describes the analysis carried out by a CO<sub>2</sub> pressure swing adsorption simulation to scale up the absorber. An unsteady one-dimensional balance model was constructed by considering the material, energy, and momentum. In the CO<sub>2</sub> breakthrough test, the beginning time and CO<sub>2</sub> concentration at outlet of CO<sub>2</sub> breakthrough in the calculation were almost equivalent to that of experiment results. The correlation consistency of the calculation results with the analysis model and the experimental results obtained by a bench scale experiment was evaluated. The transport phenomena in the adsorber were investigated at the adsorption, rinse, and desorption steps according to the calculation results. The starting time of CO<sub>2</sub> breakthrough obtained by the analysis is equal to that obtained by the adsorption breakthrough experiment. This confirms that the CO<sub>2</sub> adsorption, and the temperature and velocity distribution in the adsorber, change as a function of the adsorption, rinse, and desorption steps, respectively. Additionally, the CO<sub>2</sub> concentration of the captured gas and the amount of CO<sub>2</sub> quantity were 93.4% per day and 2.9 ton/day, respectively. These values are equal to those obtained by the bench scale experiment. 展开更多
关键词 Carbon Dioxide Separation Pressure Swing Adsorption Numerical Analysis
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甲烷/氢气在超微孔金属有机骨架中的吸附与分离性能研究 认领
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作者 刘秀英 袁俊鹏 +1 位作者 李晓东 于景新 《化工新型材料》 CAS CSCD 北大核心 2021年第2期178-181,186,共5页
使用巨正则蒙特卡罗方法(GCMC)对CH4和H2在3种具有不同结构的超微孔金属有机骨架(UM-MOFs)中的吸附与分离性能进行了研究。获得了这3种材料对CH4和H2分子的单组分吸附。通过分析它们对CH4/H2二元混合物的吸附数据,获... 使用巨正则蒙特卡罗方法(GCMC)对CH4和H2在3种具有不同结构的超微孔金属有机骨架(UM-MOFs)中的吸附与分离性能进行了研究。获得了这3种材料对CH4和H2分子的单组分吸附。通过分析它们对CH4/H2二元混合物的吸附数据,获得了相应的吸附选择性分布曲线,探索了UM-MOFs对CH4/H2分子的吸附与分离机理。 展开更多
关键词 超微孔金属有机骨架 甲烷 氢气 吸附 分离
Two isostructural Ni(Ⅱ)/Co(Ⅱ)-based metal-organic frameworks for selective dye adsorption and catalytic cycloaddition of CO_2 with epoxides 认领
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作者 Hui Hu Dashuai Zhang +8 位作者 Huiling Liu Yaoqiang Jin Jun Gao Yongzheng Zhang Zhongmin Liu Xiuling Zhang Longlong Geng Suijun Liu Ranhui Zhang 《中国化学快报:英文版》 SCIE CAS CSCD 2021年第1期557-560,共4页
Two isostructu ral Ni(Ⅱ)/Co(Ⅱ)-based metal-organic frameworks(MOFs),namely {[M_3(L)_2(bpb)_3(H_2 O)_4]·2 DMF·2 H_2 O}_n [M=Ni(HL-5,HL is short for Hui-Ling Liu);M=Co(HL-6);H_3 L=2',6'-dimethyl-[1,1... Two isostructu ral Ni(Ⅱ)/Co(Ⅱ)-based metal-organic frameworks(MOFs),namely {[M_3(L)_2(bpb)_3(H_2 O)_4]·2 DMF·2 H_2 O}_n [M=Ni(HL-5,HL is short for Hui-Ling Liu);M=Co(HL-6);H_3 L=2',6'-dimethyl-[1,1'-biphenyl]-3,4',5-tricarboxylic acid;bpb=1,4-bis(pyrid-4-yl)benzene],have been hydrothermally synthesized and structu rally characterized.Both HL-5 and HL-6,which have the same three-interpenetrated3 D pillared-layer framework with sqc306 type topology,present good selective methyl orange(MO)adsorption over rhodamine B(RhB).Moreover,the catalytic CO_2 cycloaddition properties with epoxides of the two MOFs have also been studied at ambient pressure and temperature. 展开更多
关键词 Metal-organic frameworks Dye separation Heterogeneous catalysis CO_2 cycloaddition Coordination polymers
苯并咪唑聚合物树脂吸附分离Pd(Ⅱ) 认领
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作者 蒋绍松 陈慕涵 +2 位作者 金次 邵敏 黄章杰 《云南大学学报:自然科学版》 CAS CSCD 北大核心 2021年第1期125-131,共7页
将2-巯基苯并咪唑杂环化合物接枝到氯球聚合物基体上,制备了苯并咪唑聚合物树脂(PS-MBI)吸附剂,用于氯化介质中选择性回收Pd(Ⅱ);研究优化吸附分离参数,探讨了吸附分离机理.研究结果表明,在0.1 mol·L−1的盐酸水溶液中,PS-MBI对... 将2-巯基苯并咪唑杂环化合物接枝到氯球聚合物基体上,制备了苯并咪唑聚合物树脂(PS-MBI)吸附剂,用于氯化介质中选择性回收Pd(Ⅱ);研究优化吸附分离参数,探讨了吸附分离机理.研究结果表明,在0.1 mol·L−1的盐酸水溶液中,PS-MBI对Pd(Ⅱ)有较佳的吸附效果,最大吸附容量为138.8 mg·g−1,PS-MBI可从Pd(Ⅱ),Pt(Ⅳ),Rh(Ⅲ),Cu2+,Ni2+,Fe3+,和Zn2+的混合溶液中分离Pd(Ⅱ),一步即可完成金属混合溶液中钯的分离,分离系数β(Pd/M)(M:Pt,Rh,Cu,Ni,Fe,Zn)均高于1.0×103;PS-MBI具有良好的重复使用性能,经3次吸附−洗脱循环,PS-MBI吸附Pd(Ⅱ)的回收率仍高于92.0%.FT-IR和XPS分析表明:PS-MBI吸附Pd(Ⅱ)为配位机理,Pd(Ⅱ)通过与咪唑环上N原子形成配位键,实现其与金属离子混合溶液的分离. 展开更多
关键词 杂环聚合物 吸附 分离 机理
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基于共价有机框架材料的纳滤膜制备研究进展 认领
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作者 毛晨岳 赵颂 +2 位作者 何鹏鹏 王志 王纪孝 《高校化学工程学报》 EI CAS CSCD 北大核心 2021年第1期13-23,共11页
共价有机框架(COFs)材料是由有机结构单元通过共价键连接形成的多孔纳米材料,具有比表面积大、孔隙率高、结构规整有序、稳定性好的优点,是制备高性能分离膜的理想材料,因而在纳滤膜研究领域引起广泛关注。文章综述了近几年来研究者利... 共价有机框架(COFs)材料是由有机结构单元通过共价键连接形成的多孔纳米材料,具有比表面积大、孔隙率高、结构规整有序、稳定性好的优点,是制备高性能分离膜的理想材料,因而在纳滤膜研究领域引起广泛关注。文章综述了近几年来研究者利用掺杂法、层层组装法、界面聚合法、原位生长法等制备COFs纳滤膜的研究成果,对不同制膜方法的特点进行分析,并指出目前COFs纳滤膜研究中存在的问题,最后对COFs纳滤膜的未来发展前景作出展望。 展开更多
关键词 共价有机框架材料 纳滤 分离 层层组装 界面聚合 原位生长
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Nd同位素溯源铀矿石浓缩物产地研究 认领
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作者 周佳骏 李力力 +2 位作者 姜小燕 任同祥 赵立飞 《原子能科学技术》 EI CAS CSCD 北大核心 2021年第4期620-626,共7页
铀矿石浓缩物(UOC)是核法证学中溯源研究的核材料之一,通过测量其中Nd同位素丰度比能提供地理指示信息。本文基于TRU树脂对铀和稀土元素的吸附特性,通过条件实验获得了最佳淋洗酸度和体积,分离稀土元素和大量铀基体;利用LN树脂分离镧系... 铀矿石浓缩物(UOC)是核法证学中溯源研究的核材料之一,通过测量其中Nd同位素丰度比能提供地理指示信息。本文基于TRU树脂对铀和稀土元素的吸附特性,通过条件实验获得了最佳淋洗酸度和体积,分离稀土元素和大量铀基体;利用LN树脂分离镧系元素的特性,分离具有同量异位素干扰的Sm,使用TRU和LN树脂联用方式有效分离了Nd,建立了一种能分离UOC中U、Sm和Nd的方法。应用该方法对UOC样品进行多次测量,洗脱液中U含量低于5 ng/g,有效实现了UOC中大量U与微量Nd的分离。采用多接收电感耦合等离子质谱对Nd同位素进行测量,测量精度达0.002%,满足Nd同位素测量需求。该方法已用于实际UOC样品中的Nd分离,并进行了初步溯源研究。 展开更多
关键词 铀矿浓缩物 分离 质谱 ND同位素
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Computational design of heterogeneous catalysts and gas separation materials for advanced chemical processing 认领
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作者 Huaiwei Shi Teng Zhou 《化学科学与工程前沿:英文版》 SCIE EI CSCD 2021年第1期49-59,共11页
Functional materials are widely used in chemical industry in order to reduce the process cost while simultaneously increase the product quality.Considering their significant effects,systematic methods for the optimal ... Functional materials are widely used in chemical industry in order to reduce the process cost while simultaneously increase the product quality.Considering their significant effects,systematic methods for the optimal selection and design of materials are essential.The conventional synthesis-and-test method for materials development is inefficient and costly.Additionally,the performance of the resulting materials is usually limited by the designer’s expertise.During the past few decades,computational methods have been significantly developed and they now become a very important tool for the optimal design of functional materials for various chemical processes.This article selectively focuses on two important process functional materials,namely heterogeneous catalyst and gas separation agent.Theoretical methods and representative works for computational screening and design of these materials are reviewed. 展开更多
关键词 heterogeneous catalyst gas separation SOLVENT porous adsorbent material screening and design
Isolation and structural elucidation of the compounds from the fruits of Camptotheca acuminate 认领
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作者 Jingxian Ren Zhuoyang Cheng +2 位作者 Huan He Xiaoxiao Huang Shaojiang Song 《亚洲传统医药》 CAS 2021年第2期69-75,共7页
The fruit of Camptotheca acuminate is used as a traditional Chinese medicine.Eight compounds were isolated from the fruit of Camptotheca acuminate for the first time,including(+)-(S)-abscisic acid(1),blumenol A(2),(E)... The fruit of Camptotheca acuminate is used as a traditional Chinese medicine.Eight compounds were isolated from the fruit of Camptotheca acuminate for the first time,including(+)-(S)-abscisic acid(1),blumenol A(2),(E)-3-hydroxymegastigm-7-en-9-one(3),(-)-(3R)-3,5-dimethyl-8-methoxy-3,4-dihydroisocoumarin(4),(-)-(3R)-8-methoxy-3-methyl-3,4-dihydro-1H-isochromen-1-one(5),neocnidilide(6),(3S)-butylphthalide(7)and senkyunolide I(8).Their structures were determined by comprehensive spectroscopic methods,including HRESIMS and 1D NMR. 展开更多
关键词 Camptotheca acuminate separation and purification structure elucidation
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Effects of surface roughness on the aerodynamic performance of a high subsonic compressor airfoil at low Reynolds number 认领
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作者 Mingyang WANG Chengwu YANG +3 位作者 Ziliang LI Shengfeng ZHAO Yanfeng ZHANG Xin’gen LU 《中国航空学报:英文版》 SCIE EI CAS CSCD 2021年第3期71-81,共11页
The aerodynamic performance of compressor airfoil is significantly affected by the surface roughness at low Reynolds number(Re).In the present study,numerical simulations have been conducted to investigate the impact ... The aerodynamic performance of compressor airfoil is significantly affected by the surface roughness at low Reynolds number(Re).In the present study,numerical simulations have been conducted to investigate the impact of surface roughness on the profile loss of a high subsonic compressor airfoil at Re=1.5×105.Four roughness locations,covering 10%,30%,50%and 100%of the suction surface from the leading edge and seven roughness magnitudes(Ra)ranging from 52 to525 lm were selected.Results showed that the surface roughness mainly determined the loss generation process by influencing the structure of the Laminar Separation Bubble(LSB)and the turbulence level near the wall.For all the roughness locations,the variation trend for the profile loss with the roughness magnitude was similar.In the transitionally rough region,the negative displacement effect of the LSB was suppressed with the increase of roughness magnitude,leading to a maximum decrease of 14.6%,16.04%,16.45%and 10.20%in the profile loss at Ra=157 lm for the four roughness locations,respectively.However,with a further increase of the roughness magnitude in the fully rough region,the stronger turbulent dissipation enhanced the growth rate of the turbulent boundary layer and increased the profile loss instead.By comparison,the leading edge roughness played a dominant role in the boundary layer development and performance variation.To take fully advantage of the surface roughness reducing profile loss at low Re,the effects of roughness on suppressing LSB and inducing strong turbulent dissipation should be balanced effectively. 展开更多
关键词 Aerodynamic performance Compressor airfoil Low Reynolds number Separation bubble Surface roughness Viscous dissipation
Isolation and identification of chemical constituents from Elephantopus scaber Linn. 认领
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作者 Wei Xu Ming Bai Xiaoxiao Huang 《亚洲传统医药》 CAS 2021年第2期98-104,共7页
Elephantopus scaber L.,as a popular Chinese medicinal herb of the Compositae family,is widely distributed in America,Africa and Asia.In the present study,five compounds were isolated from the 70%EtOH extract of the wh... Elephantopus scaber L.,as a popular Chinese medicinal herb of the Compositae family,is widely distributed in America,Africa and Asia.In the present study,five compounds were isolated from the 70%EtOH extract of the whole herb from Elephantopus scaber L.,including two lignans and three flavones.Their chemical structures were identified based on NMR spectroscopic analysis and comparison with the data reported in literature.It is noteworthy that compounds 1-5 were isolated from Elephantopus scaber L.for the first time and their chemotaxonomic significance was discussed. 展开更多
关键词 Elephantopus scaber L. separation and purification chemical constituents structural elucidation
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一/二价离子分离膜材料研究进展 认领
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作者 黄清波 刘公平 金万勤 《化工学报》 EI CAS CSCD 北大核心 2021年第1期334-350,共17页
一/二价离子分离膜在能源存储和转换、污染监测和控制、清洁工业过程等领域发挥重要作用。本文旨在回顾近年来一/二价离子分离膜材料的研究进展,重点综述聚合物膜、混合基质膜及金属有机骨架和二维材料等新型膜用于一/二价离子分离的研... 一/二价离子分离膜在能源存储和转换、污染监测和控制、清洁工业过程等领域发挥重要作用。本文旨在回顾近年来一/二价离子分离膜材料的研究进展,重点综述聚合物膜、混合基质膜及金属有机骨架和二维材料等新型膜用于一/二价离子分离的研究现状,深入讨论界面聚合、层层组装、沉积、共混等不同制备方法对膜微结构和分离性能的影响,探讨一/二价离子分离膜面临的主要挑战和未来研究方向。 展开更多
关键词 分离 选择性 一/二价离子 离子筛分
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A polypropylene melt-blown strategy for the facile and efficient membrane separation of oil-water mixtures 认领
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作者 Zhenqiang Zhang Danfeng Yu +7 位作者 Xiubin Xu Huayi Li Taoyan Mao Cheng Zheng Jianjia Huang Hui Yang Zihan Niu Xu Wu 《中国化学工程学报:英文版》 SCIE EI CAS CSCD 2021年第1期383-390,共8页
Porous materials with selective wettability and permeability have significant importance in oil-water separation,but complex fabrication processes are typically required to obtain the desired structures with suitable ... Porous materials with selective wettability and permeability have significant importance in oil-water separation,but complex fabrication processes are typically required to obtain the desired structures with suitable surface chemistry.In this work,an industrial melt-blown strategy that utilized commercially available polypropylene(PP)was used for the large-scale fabrication of superhydrophobic/superoleophilic membranes with staggered fabric structures.These membranes could readily separate different oils including pump oil and crude oil from various aqueous solutions such as strongly acidic,alkaline,and saline media.In addition,the separation efficiencies of these membranes exceeded 99%,and they could remain functional even after exposure to corrosive media.We anticipate that this work will further the design of membranes and enhance their applicability in oil-water separation,and provide researchers and engineers with a more effective tool for performing challenging separations and mitigating pollution. 展开更多
关键词 SEPARATION Polypropylene membranes Surface SUPERHYDROPHOBICITY Superoleophilicity Environment
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Intelligent deformation of biomedical polyurethane 认领
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作者 Maolan ZHANG Huan WANG +2 位作者 Junjie MAO Da SUN Xiaoling LIAO 《材料学前沿:英文版》 SCIE CSCD 2021年第1期1-9,共9页
Polyurethane is a general term for a class of polymerscontaining a carbamate group(-NHCOO-)in its mainchain structure,including thermoplastic elastomers,flexi-ble and rigid foams,and other species[1-2].The existenceof... Polyurethane is a general term for a class of polymerscontaining a carbamate group(-NHCOO-)in its mainchain structure,including thermoplastic elastomers,flexi-ble and rigid foams,and other species[1-2].The existenceof thermodynamically incompatible soft segments and hardsegments in the structure of polyurethane can causemicrophase separation,which gives polyurethane somesuperior characteristics.Its performance can be adjusted byredesigning the proportion and the structure of soft andhard segments[3-5]. 展开更多
关键词 POLYURETHANE STRUCTURE SEPARATION
镅(Ⅲ)与铕(Ⅲ)离子的分离方法研究进展 认领
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作者 刘姝菂 《山东化工》 CAS 2021年第6期69-71,76,共4页
镅是核燃料反应堆运行过程中产生的一种长寿命超铀元素,具有极强的放射性和化学毒性,不利于核燃料的循环利用和放射性废物的处置,严重威胁生态环境和人类生命安全,需要将其进行分离嬗变处理。但在分离过程中镧系元素由于结构与性质的相... 镅是核燃料反应堆运行过程中产生的一种长寿命超铀元素,具有极强的放射性和化学毒性,不利于核燃料的循环利用和放射性废物的处置,严重威胁生态环境和人类生命安全,需要将其进行分离嬗变处理。但在分离过程中镧系元素由于结构与性质的相似性,会对分离及后续的嬗变处理造成干扰。因此,本文综述了近十年内镅(Ⅲ)与铕(Ⅲ)离子的分离方法,期望为核燃料的循环以及核工业的发展提供参考。 展开更多
关键词 分离 检测
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从2G到5G核心网的发展演进 认领
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作者 解殿禄 《工程建设(重庆)》 2021年第2期35-37,共3页
5G网络已经商用,核心网也已经建设,要熟悉5G核心网的功能,必须熟悉、了解移动通信核心网的发展及功能。本文主要对2G、3G、4G到现在的5G核心网的发展及组网进行介绍;同时对核心网的网关功能简单明了的做了介绍。
关键词 核心网 MSC 分离 PGW NFV
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