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Evolving role of magnetic resonance techniques in primary sclerosing cholangitis 预览
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作者 Emmanuel A Selvaraj Emma L Culver +3 位作者 Helen Bungay Adam Bailey Roger W Chapman Michael Pavlides 《世界胃肠病学杂志:英文版》 SCIE CAS 2019年第6期644-658,共15页
Development of non-invasive methods to risk-stratify patients and predict clinical endpoints have been identified as one of the key research priorities in primary sclerosing cholangitis(PSC).In addition to serum and h... Development of non-invasive methods to risk-stratify patients and predict clinical endpoints have been identified as one of the key research priorities in primary sclerosing cholangitis(PSC).In addition to serum and histological biomarkers,there has been much recent interest in developing imaging biomarkers that can predict disease course and clinical outcomes in PSC.Magnetic resonance imaging/magnetic resonance cholangiopancreatography(MRI/MRCP)continue to play a central role in the diagnosis and follow-up of PSC patients.Magnetic resonance(MR)techniques have undergone significant advancement over the last three decades both in MR data acquisition and interpretation.The progression from a qualitative to quantitative approach in MR acquisition techniques and data interpretation,offers the opportunity for the development of objective and reproducible imaging biomarkers that can potentially be incorporated as an additional endpoint in clinical trials.This review article will discuss how the role of MR techniques have evolved over the last three decades from emerging as an alternative diagnostic tool to endoscopic retrograde cholangiopancreatography,to being instrumental in the ongoing search for imaging biomarker of disease stage,progression and prognosis in PSC. 展开更多
关键词 Primary SCLEROSING cholangitis MAGNETIC RESONANCE IMAGING MAGNETIC RESONANCE CHOLANGIOPANCREATOGRAPHY MAGNETIC RESONANCE ELASTOGRAPHY Diffusion MAGNETIC RESONANCE IMAGING Endoscopic retrograde CHOLANGIOPANCREATOGRAPHY
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Evaluation of tumor response to antiangiogenic therapy in patients with recurrent gliomas using contrast-enhanced perfusion-weighted magnetic resonance imaging techniques: A meta-analysis 预览
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作者 Akanganyira Kasenene Aju Baidya +1 位作者 Salman Shams Hai-Bo Xu 《世界荟萃分析杂志》 2019年第2期51-65,共15页
BACKGROUND It is of vital importance to find radiologic biomarkers that can accurately predict treatment response. Usually, the initiation of antiangiogenic therapy causes a rapid decrease in the contrast enhancing tu... BACKGROUND It is of vital importance to find radiologic biomarkers that can accurately predict treatment response. Usually, the initiation of antiangiogenic therapy causes a rapid decrease in the contrast enhancing tumor. However, the treatment response is observed only in a fraction of patients due to the partial radiological response secondary to stabilization of abnormal vessels which does not essentially indicate a true antitumor effect. Perfusion-weighted magnetic resonance imaging (PWMRI) techniques have shown implicitness as a strong imaging biomarker for gliomas since they give hemodynamic information of blood vessels. Hence, there is a rapid expansion of PW-MRI related studies and clinical applications. AIM To determine the diagnostic performance of PW-MRI techniques including:(A) dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI);and (B) dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) for evaluating response to antiangiogenic therapy in patients with recurrent gliomas. METHODS Databases such as PubMed (MEDLINE included), EMBASE, and Google Scholar were searched for relevant original articles. The included studies were assessed for methodological quality with the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Medical imaging follow-up or histopathological analysis was used as the reference standard. The data were extracted by two reviewers independently, and then the sensitivity, specificity, summary receiver operating characteristic curve, area under the curve (AUC), and heterogeneity were calculated using Meta-Disc 1.4 software.RESULTS This study analyzed a total of six articles. The overall sensitivity for DCE-MRI and DSC-MRI was 0.69 [95% confidence interval (CI): 0.53-0.82], and the specificity was 0.99 (95%CI: 0.93-1) by a random effects model (DerSimonianee- Laird model). The likelihood ratio (LR)+, LR-, and diagnostic odds ratio (DOR) were 12.84 (4.54-36.28), 0.35 (0.22-0.53), and 24.44 (7.19-83.06), respectively. The AUC (± SE) was 0.9921 (± 0.0120), 展开更多
关键词 Glioma Perfusion-weighted MAGNETIC RESONANCE IMAGING DYNAMIC contrastenhanced MAGNETIC RESONANCE IMAGING DYNAMIC susceptibility contrast MAGNETIC RESONANCE IMAGING Anti-vascular endothelial growth factor ANTIANGIOGENIC Metaanalysis
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Synthesis of PEI-Functionalized Magnetic Nanoparticles for Capturing Bacteria
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作者 陈保利 谢浩 +4 位作者 ZHANG Ao LIU Nian LI Qichang GUO Junhui SU Baolian 《武汉理工大学学报:材料科学英文版》 SCIE EI CAS 2019年第1期236-242,共7页
Polyethyleneimine(PEI) functionalized Fe3O4 MNPs were synthesized by a modified hypothermal oxidative hydrolysis method. The magnetic nanoparticles showed positively charged surface, strong magnetic responsivity and u... Polyethyleneimine(PEI) functionalized Fe3O4 MNPs were synthesized by a modified hypothermal oxidative hydrolysis method. The magnetic nanoparticles showed positively charged surface, strong magnetic responsivity and uniform particle size distribution at 56.1±0.6 nm. Aggregation of these magnetic nanoparticles were observed on the surface of different type of bacteria. Magnetic capturing of bacteria were facilitated by these magnetic nanoparticles. The capturing efficiency could reach 90% after two rounds of interactions of 5 minutes. The mechanism and process of interactions between bacteria and polyethyleneimine functionalized Fe3O4 magnetic nanoparticles were explored and discussed. The present study not only provides insight into interactions between Fe3O4@PEI MNPs and bacterial cells, but also opens a new avenue for designing and applying Fe3O4@PEI MNPs as biosensors in microbiology, medicine, and environmental science. 展开更多
关键词 MAGNETIC nanoparticles(MNPs) polyethyleneimine(PEI) MAGNETIC separation BACTERIAL surface
Chiral phase structure of the sixteen meson states in the SU(3) Polyakov linear-sigma model for finite temperature and chemical potential in a strong magnetic field
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作者 Abdel Nasser Tawfik Abdel Magied Diab M.T.Hussein 《中国物理C:英文版》 SCIE CAS CSCD 2019年第3期56-71,共16页
In characterizing the chiral phase-structure of pseudoscalar(Jpc = 0-+), scalar(Jpc = 0++), vector(Jpc =1--) and axial-vector(Jpc = 1++t) meson states and their dependence on temperature, chemical potential, and magne... In characterizing the chiral phase-structure of pseudoscalar(Jpc = 0-+), scalar(Jpc = 0++), vector(Jpc =1--) and axial-vector(Jpc = 1++t) meson states and their dependence on temperature, chemical potential, and magnetic field,we utilize the SU(3) Polyakov linear-sigma model(PLSM) in the mean-field approximation. We first determine the chiral(non)strange quark condensates,σl and σs, and the corresponding deconfinement order parameters, φ and φ*, in thermal and dense(finite chemical potential) medium and finite magnetic field. The temperature and the chemical potential characteristics of nonet meson states normalized to the lowest bosonic Matsubara frequency are analyzed. We note that all normalized meson masses become temperature independent at different critical temperatures. We observe that the chiral and deconfinement phase transitions are shifted to lower quasicritical temperatures with increasing chemical potential and magnetic field. Thus, we conclude that the magnetic field seems to have almost the same effect as the chemical potential, especially on accelerating the phase transition, i.e. inverse magnetic catalysis. We also find that increasing the chemical potential enhances the mass degeneracy of the various meson masses, while increasing the magnetic field seems to reduce the critical chemical potential, at which the chiral phase transition takes place. Our mass spectrum calculations agree well with the recent PDG compilations and PNJL, lattice QCD calculations, and QMD/UrQMD simulations. 展开更多
关键词 CHIRAL transition MAGNETIC fields MAGNETIC catalysis critical temperature viscous properties of QGP
Enhanced soft magnetic properties of iron powders through coating MnZn ferrite by one-step sol–gel synthesis
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作者 刘冬 高善民 +4 位作者 金仁成 王峰 初晓晓 高太平 王玉宝 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第5期300-304,共5页
The MnZn ferrite coating formed on the surface of iron-based soft magnetic powders via facile and modified sol–gel process has been fabricated to obtain better magnetic performance due to its higher permeability comp... The MnZn ferrite coating formed on the surface of iron-based soft magnetic powders via facile and modified sol–gel process has been fabricated to obtain better magnetic performance due to its higher permeability compared with traditional nonmagnetic insulation coatings.The influence of the MnZn ferrite contents on the magnetic performance of the soft magnetic composites (SMCs) has been studied.As the MnZn insulation content increases,the core loss first experiences a decreasing trend that is followed by progressive increase,while the permeability follows an increasing trend and subsequently degrades.The optimized magnetic performance is achieved with 2.0 wt% MnZn ferrite,which results from the decrement of inter-particle eddy current losses based on loss separation.A uniform and compact coating layer composed of MnZn ferrite and oxides with an average thickness of 0.38±0.08 μm is obtained by utilizing ion beam technology,and the interface between the powders and the coating shows satisfied adhesiveness compared with the sample directly prepared by mechanical mixing.The evolution of the coating layers during the calcination process has been presented based on careful analysis of the composition and microstructure. 展开更多
关键词 soft MAGNETIC POWDERS MAGNETIC performance COATING layer ion beam technology
Magnetic separation of pentlandite from serpentine by selective magnetic coating 预览
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作者 Ji-wei Lu Zhi-tao Yuan +2 位作者 Xiao-fei Guo Zhong-yun Tong Li-xia Li 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2019年第1期1-10,共10页
In this study,pentlandite was selectively separated from serpentine using magnetic coating technology by adjusting and optimizing pH,stirring speeds,magnetic field intensities,and dosages of sodium hexametaphosphate(S... In this study,pentlandite was selectively separated from serpentine using magnetic coating technology by adjusting and optimizing pH,stirring speeds,magnetic field intensities,and dosages of sodium hexametaphosphate(SHMP)and sodium oleate(SO).A magnetic concentrate with Ni grade of 20.8%and Ni recovery of 80.5%was attained under the optimized operating conditions.Considering the above,the adsorption behaviors of SHMP and SO and the surface properties of minerals after the magnetic coating were studied by Fourier transform infrared(FTIR)spectroscopy,X-ray diffraction(XRD),and scanning electron microscopy(SEM).The results show that magnetite was preferentially coated on the pentlandite surfaces and sparingly coated on the serpentine surfaces in the presence of SHMP and SO.Furthermore,calculations by Derjaguin-Landau-Verwey-Overbeek(DLVO)theory indicate that the preferential adsorption of magnetite on the pentlandite surfaces is due to the presence of a hydrophobic interaction between the magnetite and pentlandite,which is much stronger than the interaction between magnetite and serpentine. 展开更多
关键词 DISPERSANT COAGULANT MAGNETIC COATING MAGNETIC separation hydrophobic interaction
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钙钛矿锰氧化物La0.8-xEuxSr0.2MnO3(x=0,0.05)的磁性和磁熵变研究
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作者 曹凤泽 陈红伟 +6 位作者 藏宝 刘娇 田野 周敏 鲁毅 赵建军 金香 《低温物理学报》 CAS 北大核心 2019年第1期42-48,共7页
本篇文章主要研究钙钛矿氧化物La0.8-xEuxSr0.2MnO3(x=0,0.05)中A位掺杂铕(Eu)后对样品的磁性和磁熵变的影响。采用传统的固相反应法制备多晶样品,根据数据拟合得到XRD图像和晶格参数,通过对两样品的M-T曲线和M-H曲线研究发现:x=0和x=0... 本篇文章主要研究钙钛矿氧化物La0.8-xEuxSr0.2MnO3(x=0,0.05)中A位掺杂铕(Eu)后对样品的磁性和磁熵变的影响。采用传统的固相反应法制备多晶样品,根据数据拟合得到XRD图像和晶格参数,通过对两样品的M-T曲线和M-H曲线研究发现:x=0和x=0.05两样品在高温区均表现出顺磁性,居里温度Tc分别为283 K(x=0)和284 K(x=0.05),且在居里温度附近表现出铁磁性。随着掺杂量增加,样品的居里外斯温度降低(θ_(x=0)=322 K、θ_(x=0.05)=304 K),表明Eu^(3+)掺杂改变了系统内的铁磁耦合。在7 T磁场下磁熵变的最大值分别为2.73 J/kg·K和4.19 J/kg·K,表明Eu^(3+)掺杂使得最大磁熵变值增大。对比制冷效率,发现该系列样品具有作为磁制冷材料的潜质。 展开更多
关键词 钙钛矿 磁性 磁熵变
Accuracy of multi-echo Dixon sequence in quantification of hepatic steatosis in Chinese children and adolescents 预览
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作者 Yu-Zhen Zhao Yun-Gen Gan +7 位作者 Jian-Li Zhou Jia-Qi Liu Wei-Guo Cao Shu-Mei Cheng Da-Ming Bai Meng-Zhu Wang Fang-Qin Gao Shao-Ming Zhou 《世界胃肠病学杂志:英文版》 SCIE CAS 2019年第12期1513-1523,共11页
BACKGROUND Nonalcoholic fatty liver disease (NAFLD) is currently the outstanding cause of chronic liver disease in children and adolescents, especially in overweight and obese groups. Liver biopsy is the reference sta... BACKGROUND Nonalcoholic fatty liver disease (NAFLD) is currently the outstanding cause of chronic liver disease in children and adolescents, especially in overweight and obese groups. Liver biopsy is the reference standard to diagnose NAFLD but invasive, thus it is not the best choice in clinical diagnosis and follow-up. Magnetic resonance (MR) is widely used in clinical trials to noninvasively quantify liver fat content in adults and children in foreign countries. While currently, it is rarely used in Chinese children and adolescents. We postulated that quantifying hepatic steatosis by MR could be extended to children and adolescents in China. AIM To investigate the accuracy of MR imaging (MRI) in quantifying liver fat with MR spectroscopy (MRS) as a reference. A secondary goal was to assess the prevalence of NAFLD in overweight and obese Chinese children and adolescents. METHODS There were 86 children and adolescents enrolled in this study, including 65 overweight and obese children and 21 healthy children. The participants underwent MRI and MRS. MRI and MRS were performed using multi-echo Dixon and HISTO sequences, respectively, to calculate hepatic proton density fat fraction (PDFF). Hepatic steatosis was diagnosed using MRS-PDFF>5% as the threshold. Spearman’s analysis was used to evaluate the correlation between MRI and MRS. The agreement between these two methods was assessed by Bland- Altman analysis. RESULTS The MRI-PDFF in the MRS region of interest and the entire liver was 9.9%±10.3% with a range of 0.3%-39.9%, and 10.6%±9.4% with a range of 1.9%-38.9%, respectively. The MRS-PDFF was 9.1%±10.0%, with a range of 0.5%-37.8%. The incidence of hepatic steatosis detected by MRS-PDFF was 46.5%(40/86) of all participants, all of whom belonged to the overweight and obese group. Spearman’s analysis indicated an excellent correlation between multi-echo Dixon and MRS (r>0.9, P<0.01). Bland-Altman analysis also demonstrated a good agreement between these two methods. CONCLUSION Multi-echo Dixon shows an exc 展开更多
关键词 NONALCOHOLIC FATTY liver disease MAGNETIC RESONANCE imaging MAGNETIC RESONANCE spectroscopy Children and adolescents Hepatic STEATOSIS
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Subwavelength negative-index waveguiding enabled by coupled spoof magnetic localized surface plasmons
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作者 Zhen Liao Guo Qing Luo +2 位作者 Ben Geng Cai Bai Cao Pan Wen Hui Cao 《光子学研究:英文版》 CSCD 2019年第3期274-282,共9页
Magnetic localized surface plasmon modes are supported on metallic spiral structures. Coupling mechanisms for these metamaterial resonators, which are the joint action of magnetic and electric coupling, are studied. B... Magnetic localized surface plasmon modes are supported on metallic spiral structures. Coupling mechanisms for these metamaterial resonators, which are the joint action of magnetic and electric coupling, are studied. Based on the strong coupling, spoof magnetic plasmon modes propagating in the backward direction are proposed along a chain of subwavelength resonators. The theoretical analysis, numerical simulations, and experiments are in good agreement. The proposed novel route for achieving negative-index waveguiding has potential applications in integrated devices and circuits. 展开更多
关键词 SUBWAVELENGTH NEGATIVE-INDEX waveguiding COUPLED spoof MAGNETIC LOCALIZED SURFACE plasmons MAGNETIC LOCALIZED SURFACE plasmon modes
Preparation of magnetically separable mesoporous activated carbons from brown coal with Fe3O4 预览
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作者 Yong Jiang Qiang Xie +3 位作者 Yanhai Zhang Cuiyu Geng Bin Yu Juan Chi 《矿业科学技术学报:英文版》 CSCD 2019年第3期513-519,共7页
Magnetically separable mesoporous activated carbon was prepared from brown coal in the presence of Fe3O4 as a bi-functional additive.Magnetic activated carbon(MAC)was characterized by lowtemperature nitrogen adsorptio... Magnetically separable mesoporous activated carbon was prepared from brown coal in the presence of Fe3O4 as a bi-functional additive.Magnetic activated carbon(MAC)was characterized by lowtemperature nitrogen adsorption,scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS)and vibrating sample magnetometry(VSM).The evolution behaviors and transition mechanism of Fe3O4 during the preparation of MAC were investigated.The results show that prepared MAC with 6 wt%Fe3O4 addition having a specific surface area and mesopore ratio of 370 m^2·g^-1 and 55.7%,which meet the requirements of adsorption application and magnetic recovery.Highly dispersed iron-containing aggregates with the size of 0.1 lm in the MAC were observed.During the preparation of MAC,Fe3O4 could enhance the escape of volatiles during the carbonization.Fe3O4 could also accelerate burning off the carbon wall during activation,which leads to enlarging micropore size,then resulting in the generation of mesopore and macropore.As a result,a part of Fe3O4 converted into FeO,FeOOH,a-Fe,c-Fe,Fe2SiO4 and compound of Aluminum-iron-silicon.The prepared activated carbon,which was magnetized by both of residual Fe3O4,reduced a-Fe and c-Fe,can be easily separated from the original solution by external magnetic field. 展开更多
关键词 MAGNETIC ACTIVATED carbon PREPARATION BROWN coal Ferroferric oxide MAGNETIC separation
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Effects of muscle fiber orientation to main magnetic field on muscle metabolite profiles for magnetic resonance spectroscopy acquisition 预览
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作者 Duanghathai Pasanta Tipparat Kongseha Suchart Kothan 《世界放射学杂志:英文版(电子版)》 2019年第1期1-9,共9页
BACKGROUND Proton magnetic resonance spectroscopy(1H MRS)is a technique widely used for investigating metabolites in humans.Lipids are stored outside the muscle cell are called extramyocellular lipids(EMCL),and lipids... BACKGROUND Proton magnetic resonance spectroscopy(1H MRS)is a technique widely used for investigating metabolites in humans.Lipids are stored outside the muscle cell are called extramyocellular lipids(EMCL),and lipids stored on the inside of muscle cells are called intramyocellular lipids(IMCL).The relationship between metabolic syndrome and IMCL has been extensively studied.AIM To determine the effects of muscle fiber orientations on muscle metabolites using 1H MRS.METHODS Chicken muscles were used as the subject in this study.MRS spectra were performed on a 1.5T Magnetic resonance imaging machine(1.5 Tesla Philips Achieva).A single voxel(8 mm×8 mm×20 mm)was placed on the chicken extensor iliotibialis lateralis muscle with the muscle fiber oriented at 0°,30°,60°,and 90°to the main magnetic field.1H MRS spectra were acquired using a pointresolved spectroscopy,TR=2000 ms,TE=30 ms,and NSA=256.Metabolites of interest from each orientation to the main magnetic field were compared using Wilcoxon signed-rank test.Differences less than 0.05 were considered to be statistically significant with 95%CI.RESULTS The metabolite profiles were different for each orientation of muscle fibers to the main magnetic field.The orientation at 90°was the most different compared to other orientations.The quantity of IMCL and EMCL exhibited statistically significantly changes with impacts at 30°,60°,and 90°when compared with muscles aligned at 0°to the main magnetic field.Statistical analysis showed statistically significant IMCL(CH3),EMCL(CH3),and IMCL(CH2)at 30°,60°,and 90°(P=0.017,0.018,and 0.018,respectively)and EMCL(CH2)at 30°and 60°(P=0.017 and 0.042,respectively).EMCL(CH2)at 90°was unable to be measured in this study.The muscle lipids quantified at 30°,60°,and 90°tended to be lower when compared to 0°.CONCLUSION Careful positioning is one of the most important factors to consider when studying 1H MRS metabolites in muscles to ensure reproducibility and uniformity of muscle metabolite spectra. 展开更多
关键词 PROTON MAGNETIC resonance spectroscopy METABOLITE MUSCLE fiber ORIENTATION Intramyocellular LIPIDS Extramyocellular LIPIDS MAGNETIC susceptibility
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Dynamic metabolite alterations of Portunus trituberculatus during larval development 预览
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作者 SHI Ce ZENG Tinglan +3 位作者 LI Ronghua WANG Chunlin YE Yangfang MU Changkao 《海洋湖沼学报(英文)》 SCIE CAS CSCD 2019年第1期361-372,共12页
A mass mortality often occurs from molting to the megalopa stage during the larval development of the swimming crab Portunus trituberculatus.Larvae with insufficient nutrient accumulation during the zoeal stages are p... A mass mortality often occurs from molting to the megalopa stage during the larval development of the swimming crab Portunus trituberculatus.Larvae with insufficient nutrient accumulation during the zoeal stages are probably unable to develop into juvenile swimming crabs.However,the nutritional information such as the primary metabolites is scarce for P.trituberculatus larvae.The aim of this work is to obtain an insight into the metabolite traits of P.trituberculatus at early developmental stages.1 H nuclear magnetic resonance spectroscopy coupled with multivariate data analysis was used to determine how the metabolite profiles shift during larval development in P.trituberculatus.Our results show that the trend of total metabolites exhibited a rise from zoea 1 to zoea 3,followed by a drop from zoea 4 to megalopa and recovery during the first juvenile stage.A large-scale depletion of total metabolites in the zoea 4 and megalopa stages suggests a deep depression of metabolic activity,which may be linked to the mass mortality from molting to the megalopa stage.These findings provided essential metabolic information about the larval development of P.trituberculatus and important clues for understanding the nutritional requirements of P.trituberculatus in early developmental stages. 展开更多
关键词 Portunus TRITUBERCULATUS LARVAL development METABOLITE PHENOTYPE NUCLEAR magnetic resonance(NMR)
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Enhanced structural and magnetic properties of microwave sintered Li–Ni–Co ferrites prepared by sol–gel method
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作者 NANDeibam Nilima M Maisnam Sumitra Phanjoubam 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第2期358-362,共5页
The properties of lithium ferrites are very sensitive to chemical composition, synthesis method, and sintering techniques. Li–Ni–Co ferrites with compositional formula Li0.45-0.5xNi0.1CoxFe2.45-0.5xO4, where 0.00 ≤... The properties of lithium ferrites are very sensitive to chemical composition, synthesis method, and sintering techniques. Li–Ni–Co ferrites with compositional formula Li0.45-0.5xNi0.1CoxFe2.45-0.5xO4, where 0.00 ≤ x ≤ 0.1 in steps of 0.02 were prepared by chemical sol–gel method and sintered by microwave sintering technique. The x-ray diffraction patterns confirmed the formation of single phase with spinel structure in all the samples. The structural parameter viz.lattice constant, crystallite size, and x-ray density for these samples were studied and compared with those measured from samples of similar composition prepared by the sol–gel method and sintered by conventional sintering technique. Enhancement in the magnetic properties like Curie temperature, hysteresis parameters was observed by employing sol–gel synthesis combined with microwave sintering. The results obtained and mechanisms involved are discussed in the paper. 展开更多
关键词 LITHIUM ferrites sol–gel CHEMISTRY MAGNETIC properties x-ray DIFFRACTION
Incorporating the magnetic alignment of GO composites into Pebax matrix for gas separation 预览
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作者 Weifang Zhu Yun Qin +3 位作者 Zhongming Wang Jianshu Zhang Ruili Guo Xueqin Li 《能源化学:英文版》 SCIE EI CAS CSCD 2019年第4期1-10,共10页
The mixed matrix membranes (MMMs) were developed by incorporating graphite oxide (GO) flakes functionalized with iron oxide (Fe3O4) into Pebax matrix.The Pebax/Fe3O4-GO MMMs were used to separate CO2/CH4 and CO2/N2 ga... The mixed matrix membranes (MMMs) were developed by incorporating graphite oxide (GO) flakes functionalized with iron oxide (Fe3O4) into Pebax matrix.The Pebax/Fe3O4-GO MMMs were used to separate CO2/CH4 and CO2/N2 gas mixture.The results showed that the MMMs with magnetic alignment presented the better gas separation performance than that of random arrangement of Pebax/Fe3O4-GO mixed matrix membranes.The reason was that the Fe3O4-GO flakes arranged magnetically in the membrane played a multiple role in improving the performance of MMMs.Firstly,under the action of the magnetic field,the magnetic alignment of Fe3O4-GO flakes in Pebax matrix constructed the shorter transfer path for gas molecule,increasing the CO2 permeability.Secondly,the hydroxyl groups in GO flakes and the presence of Fe3O4 have stronger binding force for water,improving the CO2 solubility selectivity.Thirdly,the better interaction between the magnetic alignment of GO composites and polymer matrix,reduced the interface defects.Especially,the optimum gas separation performance was obtai ned at the Fe3O4-GO flakes content of 3 wt% in Pebax matrix at vertical arrangement with selectivity of 47 and 75 for CO2/CH4 and CO2/N2,respectively,and CO2 permeability of 538 Barrer at 0.2 MPa and room temperature. 展开更多
关键词 CO2 separation The mixed MATRIX membranes Fe3O4–GO FLAKES CO2 PERMEABILITY Magnetic ALIGNMENT
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Tuning spin reorientation in Er1–xYxFeO3 single crystal family
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作者 Ning Yuan Ru-Bin Li +6 位作者 You-Shuang Yu Zheng-Jie Feng Bao-Juan Kang Shi-Yi Zhuo Jun-Yi Ge Jin-Cang Zhang Shi-Xun Cao 《物理学前沿:英文版》 SCIE CSCD 2019年第1期105-110,共6页
A temperature-induced spin reorientation transition between &Gcy;4 (Gx, Ay, Fz) and &Gcy;2 (Fx, Cy, Gz) has been studied in the family of Er1–xYxFeO3 (x = 0, 0.25, 0.5, 0.75, 1) single crystals. By doping non... A temperature-induced spin reorientation transition between &Gcy;4 (Gx, Ay, Fz) and &Gcy;2 (Fx, Cy, Gz) has been studied in the family of Er1–xYxFeO3 (x = 0, 0.25, 0.5, 0.75, 1) single crystals. By doping nonmagnetic Y3+, we tuned the spin reorientation temperature to low temperature with increasing x. Moreover, the typical compensation point and spin flip transition of ErFeO3 also decreases with doping, and disappears above x = 0.75. We also report the Rietveld refinements and Raman spectroscopy of Er1–xYxFeO3, where some Raman peaks are shifted to low frequency with increasing doping. Our results shed light on the understanding of the interaction between two magnetic sub-lattices of rare earth (R3+) and iron (Fe3+) ions, and will also contribute to the materials design and potential applications. 展开更多
关键词 Er1–xYxFeO3 single CRYSTAL GROWTH MAGNETIC MEASUREMENTS
Artificial intelligence system of faster region-based convolutional neural network surpassing senior radiologists in evaluation of metastatic lymph nodes of rectal cancer
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作者 Lei Ding Guang-Wei Liu +11 位作者 Bao-Chun Zhao Yun-Peng Zhou Shuai Li Zheng-Dong Zhang Yu-Ting Guo Ai-Qin Li Yun Lu Hong-Wei Yao Wei-Tang Yuan Gui-Ying Wang Dian-Liang Zhang Lei Wang 《中华医学杂志:英文版》 SCIE CAS CSCD 2019年第4期379-387,共9页
Background: An artificial intelligence system of Faster Region-based Convolutional Neural Network (Faster R-CNN) is newly developed for the diagnosis of metastatic lymph node (LN) in rectal cancer patients. The primar... Background: An artificial intelligence system of Faster Region-based Convolutional Neural Network (Faster R-CNN) is newly developed for the diagnosis of metastatic lymph node (LN) in rectal cancer patients. The primary objective of this study was to comprehensively verify its accuracy in clinical use. Methods: Four hundred fourteen patients with rectal cancer discharged between January 2013 and March 2015 were collected from 6 clinical centers, and the magnetic resonance imaging data for pelvic metastatic LNs of each patient was identified by Faster R-CNN. Faster R-CNN based diagnoses were compared with radiologist based diagnoses and pathologist based diagnoses for methodological verification, using correlation analyses and consistency check. For clinical verification, the patients were retrospectively followed up by telephone for 36 months, with post-operative recurrence of rectal cancer as a clinical outcome;recurrence-free survivals of the patients were compared among different diagnostic groups, by methods of Kaplan-Meier and Cox hazards regression model. Results: Significant correlations were observed between any 2 factors among the numbers of metastatic LNs separately diagnosed by radiologists, Faster R-CNN and pathologists, as evidenced by rradiologist-Faster R-CNN of 0.912, rPathologist-radiologist of 0.134, and rPathologist-Faster R-CNN of 0.448 respectively. The value of kappa coefficient in N staging between Faster R-CNN and pathologists was 0.573, and this value between radiologists and pathologists was 0.473. The 3 groups of Faster R-CNN, radiologists and pathologists showed no significant differences in the recurrence-free survival time for stage N0 and N1 patients, but significant differences were found for stage N2 patients. Conclusion: Faster R-CNN surpasses radiologists in the evaluation of pelvic metastatic LNs of rectal cancer, but is not on par with pathologists. 展开更多
关键词 AI (Artificial Intelligence) Magnetic resonance imaging PATHOLOGY LYMPH NODES RECTAL cancer
Mn(Ⅱ) Based Coordination Polymer Involving 1,2,4,5-Benzenetetraboxylic Acid and 4,4-Bis(imidazol-1-ylmethyl)biphenyl: Synthetic, Structure and Magnetic Property 预览
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作者 王潇 韩友 +4 位作者 韩星星 邹彩常 刘怡阳 李婧 侯向阳 《结构化学》 SCIE CAS CSCD 2019年第5期791-796,670共7页
A novel Mn(Ⅱ)coordination polymer(CP),[Mn(BBA)0.5(BIYB)]n(1),was gained by the 1,2,4,5-benzenetetracarboxylic acid(H4BBA),4,4-bis(imidazol-1-ylmethyl)biphenyl(BIYB),and Mn(CH3COO)2·4H2O under hydrothermal reacti... A novel Mn(Ⅱ)coordination polymer(CP),[Mn(BBA)0.5(BIYB)]n(1),was gained by the 1,2,4,5-benzenetetracarboxylic acid(H4BBA),4,4-bis(imidazol-1-ylmethyl)biphenyl(BIYB),and Mn(CH3COO)2·4H2O under hydrothermal reaction.CP 1 was characterized and structurally determined by elemental analyses,PXRD,IR spectra,thermal behaviors,and X-ray single-crystal diffraction.The framework structure of 1 shows a novel(2,5,6)-connected 3Dnetwork with a Schlafli symbol of(4^3.6^6.8)^2(4^6.6^9)(6)^2.It crystallizes in triclinic system,space group P1,with a=7.5898(5),b=9.8201(6),c=14.1307(9)A,α=97.5850(10),β=99.6810(10),γ=111.6580(10)o,V=943.01(10)A3,Z=2,C23H15MnN 4O4,Mr=466.33,Dc=1.462 g/cm^3,F(000)=476,S=1.082,R=0.0361 and wR=0.1008.The magnetic property of CP 1 was investigated.The weak antiferromagnetic interactions are observed between the Mn(Ⅱ)ions. 展开更多
关键词 synthesis STRUCTURE magnetic properties
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Molecular characterization, spatial-temporal expression and magnetic response patterns of iron-sulfur cluster assembly1 (IscA1) in the rice planthopper, Nilaparvata lugens
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作者 Jing-Jing Xu Ying-Chao Zhang +6 位作者 Jian-Qi Wu Wei-Hong Wang Yue Li Gui-Jun Wan Fa-Jun Chen Gregory A. Sword Wei-Dong Pan 《昆虫科学:英文版》 SCIE CAS CSCD 2019年第3期413-423,共11页
The mechanisms of magnetoreception have been proposed as the magnetitebased, the chemical radical-pair and biocompass model, in which magnetite particles, the cryptochrome (Cry) or iron-sulfur cluster assembly 1 (IscA... The mechanisms of magnetoreception have been proposed as the magnetitebased, the chemical radical-pair and biocompass model, in which magnetite particles, the cryptochrome (Cry) or iron-sulfur cluster assembly 1 (IscA1) may be involved. However, little is known about the association among the molecules. Here we investigated the molecular characterization and the mRNA expression of IscA1 in different developmental stages, tissues and magnetic fields in the migratory brown planthopper (BPH), Nilaparvata lugens. NlIscA1 contains an open reading frame of 390 bp, encoding amino acids of 129, with the predicted molecular weight of 14.0 kDa and the isoelectric point of 9.10. Well-conserved Fe-S cluster binding sites were observed in the predicted protein. Phylogenetic analysis demonstrated NlIscA1 to be clustered into the insect's IscA1. NlIscA1 showed up-regulated mRNA expression during the period of migration. The mRNA expression of NlIscA1 could be detected in all the three tissues of head, thorax and abdomen, with the highest expression level in the abdomen. For the macropterous migratory Nilaparvata lugens, mRNA expression of NlIscA1 and N. lugens cryptochromel (Nlcry1) were up-regulated under the magnetic fields of 5 Gauss and 10 Gauss in strength (vs. local geomagnetic field), while N. lugens cryptochrome 2 (Nlcry2) remained stable. For the brachyterous non-migratory Nilaparvata lugens, no significant changes were found in mRNA expression of NlIscA1, Nlcry1 and Nlcry2 among different magnetic fields. These findings preliminarily reveal that the expression of NlIscA1 and Nlcry1 exhibited coordinated responses to the magnetic field. It suggests some potential associations among the putative magneto-sensitive molecules of cryptochrome and iron-sulfur cluster assembly. 展开更多
关键词 CRYPTOCHROME iron-sulfur cluster assemblyl magnetic field migratory NILAPARVATA LUGENS
Magnetochemistry and chemical synthesis
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作者 胡林 夏国良 陈乾旺 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第3期5-16,共12页
High magnetic field is one of the effective tools to control a chemical reaction and materials synthesis. In this review,we summarized the magnetic field effects on chemical reactions, such as reaction pathway, growth... High magnetic field is one of the effective tools to control a chemical reaction and materials synthesis. In this review,we summarized the magnetic field effects on chemical reactions, such as reaction pathway, growth behavior of nanomaterials, product phase, and magnetic domain of materials. The surface spins and activity of catalysts under magnetic fields were also discussed. 展开更多
关键词 MAGNETOCHEMISTRY MAGNETIC FIELD EFFECTS
Effect of retained austenite and nonmetallic inclusions on the thermal/electrical properties and resistance spot welding nuggets of Si-containing TRIP steels 预览
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作者 V.H.Vargas I.Mejía +1 位作者 V.H.Baltazar-Hernández C.Maldonado 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2019年第1期52-63,共12页
Five advanced high-strength transformation-induced plasticity(TRIP)steels with different chemical compositions were studied to correlate the retained austenite and nonmetallic inclusion content with their physical pro... Five advanced high-strength transformation-induced plasticity(TRIP)steels with different chemical compositions were studied to correlate the retained austenite and nonmetallic inclusion content with their physical properties and the characteristics of the resistance spot welding nuggets.Electrical and thermal properties and equilibrium phases of TRIP steels were predicted using the JMatPro software.Retained austenite and nonmetallic inclusions were quantified by X-ray diffraction and saturation magnetization techniques.The nonmetallic inclusions were characterized by scanning electron microscopy.The results show that the contents of Si,C,Al,and Mn in TRIP steels increase both the retained austenite and the nonmetallic inclusion contents.We found that nonmetallic inclusions affect the thermal and electrical properties of the TRIP steels and that the differences between these properties tend to result in different cooling rates during the welding process.The results are discussed in terms of the electrical and thermal properties determined from the chemical composition and their impact on the resistance spot welding nuggets. 展开更多
关键词 transformation-induced plasticity steel retained austenite non-metallic inclusions magnetic saturation electrical PROPERTIES THERMAL PROPERTIES resistance spot welding NUGGET
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