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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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Imaging plaque inflammation in asymptomatic cocaine addicted individuals with simultaneous positron emission tomography/magnetic resonance imaging 预览
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作者 Keren Bachi Venkatesh Mani +4 位作者 Audrey E Kaufman Nadia Alie Rita Z Goldstein Zahi A Fayad Nelly Alia-Klein 《世界放射学杂志:英文版(电子版)》 2019年第5期62-73,共12页
BACKGROUND Chronic cocaine use is associated with stroke, coronary artery disease and myocardial infarction, resulting in severe impairments or sudden mortality. In the absence of clear cardiovascular symptoms, indivi... BACKGROUND Chronic cocaine use is associated with stroke, coronary artery disease and myocardial infarction, resulting in severe impairments or sudden mortality. In the absence of clear cardiovascular symptoms, individuals with cocaine use disorder (iCUD) seeking addiction treatment receive mostly psychotherapy and psychiatric pharmacotherapy, with no attention to vascular disease (i.e., atherosclerosis). Little is known about the pre-clinical signs of cardiovascular risk in iCUD and early signs of vascular disease are undetected in this underserved population. AIM To assess inflammation, plaque burden and plaque composition in iCUD aiming to detect markers of atherosclerosis and vascular disease. METHODS The bilateral carotid arteries were imaged with positron emission tomography/magnetic resonance imaging (PET/MRI) in iCUD asymptomatic for cardiovascular disease, healthy controls, and individuals with cardiovascular risk. PET with 18F-fluorodeoxyglucose (18F-FDG) evaluated vascular inflammation and 3-D dark-blood MRI assessed plaque burden including wall area and thickness. Drug use and severity of addiction were assessed with standardized instruments. RESULTS The majority of iCUD and controls had carotid FDG-PET signal greater than 1.6 but lower than 3, indicating the presence of mild to moderate inflammation. However, the MRI measure of wall structure was thicker in iCUD as compared to the controls and cardiovascular risk group, indicating greater carotid plaque burden. iCUD had larger wall area as compared to the healthy controls but not as compared to the cardiovascular risk group, indicating structural wall similarities between the non-control study groups. In iCUD, wall area correlated with greater cocaine withdrawal and craving. CONCLUSION These preliminary results show markers of carotid artery disease burden in cardiovascular disease-asymptomatic iCUD. Broader trials are warranted to develop protocols for early detection of cardiovascular risk and preventive intervention in iCUD. 展开更多
关键词 3-D dark-blood magnetic resonance imaging 18F-fluorodeoxyglucose POSITRON emission TOMOGRAPHY SIMULTANEOUS POSITRON emission TOMOGRAPHY Magnetic resonance Substance use disorder COCAINE addiction Atherosclerosis PLAQUE burden Vascular INFLAMMATION
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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
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
Field-variable magnetic domain characterization of individual 10 nm Fe3O4 nanoparticles
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作者 李正华 李翔 陆伟 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第7期470-474,共5页
The local detection of magnetic domains of isolated 10 nm Fe3O4 magnetic nanoparticles(MNPs) has been achieved by field-variable magnetic force microscopy(MFM) with high spatial resolution.The domain configuration of ... The local detection of magnetic domains of isolated 10 nm Fe3O4 magnetic nanoparticles(MNPs) has been achieved by field-variable magnetic force microscopy(MFM) with high spatial resolution.The domain configuration of an individual MNP shows a typical dipolar response.The magnetization reversal of MNP domains is governed by a coherent rotation mechanism, which is consistent with the theoretical results given by micromagnetic calculations.Present results suggest that the field-variable MFM has great potential in providing nanoscale magnetic information on magnetic nanostructures,such as nanoparticles, nanodots, skyrmions, and vortices, with high spatial resolution.This is crucial for the development and application of magnetic nanostructures and devices. 展开更多
关键词 Fe3O4 nanoparticles MAGNETIC force MICROSCOPY MAGNETIC DOMAIN
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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Magnetization Reversal in Magnetic Bilayer Systems
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作者 金礼鹏 刘拥军 《中国物理快报:英文版》 SCIE CAS CSCD 2019年第6期88-92,共5页
Magnetization reversal in magnetic soft/hard bilayer systems is studied analytically by means of a variational method for magnetic energies in a continuum model. The demagnetization curve is involved with nonlinear eq... Magnetization reversal in magnetic soft/hard bilayer systems is studied analytically by means of a variational method for magnetic energies in a continuum model. The demagnetization curve is involved with nonlinear equations,and the solution is given implicitly in the form of Jacobi functions,which is valid for the total reversal process. Based on the non-trivial solutions, hysteresis loops, as well as the maximum energy product(BH)max versus thicknesses of soft/hard layers are obtained. With regard to(BH)max, improvement of the remanence competes with loss of coercive force. As a result, an optimum condition exists. For a given thickness of the hard layer, the optimum condition at which the largest(BH)max could be achieved is discussed, which is slightly different from previous works. 展开更多
关键词 MAGNETIZATION REVERSAL MAGNETIC BILAYER SYSTEMS MAGNETIC ENERGIES
Magnetic properties and magnetic entropy change of perovskite manganites La0.9-xEuxSr0.1MnO3(x=0.000,0.075) by experimental method and numerical fitting
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作者 Xiang Jin Jianjun Zhao +8 位作者 Hongye Wu Bao Xu Yunbin Sun Xiaodong Sun Fengze Cao Kai Wang Wenxing Wang Yutong Zhang Yi Lu 《中国稀土学报:英文版》 SCIE EI CAS CSCD 2019年第6期622-627,共6页
Polycrystalline samples La0.9-xEuxSr0.1MnO3(x = 0.000, 0.075) were prepared by the standard solid-state reaction method. The results show that the samples preform a characteristic of clusters spin-glass state at low t... Polycrystalline samples La0.9-xEuxSr0.1MnO3(x = 0.000, 0.075) were prepared by the standard solid-state reaction method. The results show that the samples preform a characteristic of clusters spin-glass state at low temperature. The samples show a characteristic of ferromagnetism(FM) characteristic in the temperature range of 15-125 K and 15-150 K respectively;the samples show preformed clusters in the temperature range of 125-343 K and 150-325 K, respectively, the samples show paramagnetism(PM)characteristic above 343 and 325 K, respectively. The second-order transitions are found at 118 and 135 K for undoped and doped sample, respectively. When the applied magnetic field is 7 T, the maximum magnetic entropy change |△SM| value of the samples is near the Curie temperature(Tc), and the value of|△SM| reaches 2.76 and 3.03 J/(K kg), respectively. In addition, the relative cooling power(RCP) is found to be 425.28 and 443.53 J/kg. The numerical fitting data fit well with experimental data. These results indicate that both the samples have the potential to realize magnetic refrigeration in the high temperature region(T > 77 K). 展开更多
关键词 PEROVSKITE MAGNETIC properties MAGNETIC ENTROPY change Preforming cluster phase Least SQUARE method Rare earths
The predicaments and expectations in development of magnetic semiconductors 预览
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作者 Qiang Cao Shishen Yan 《半导体学报:英文版》 EI CAS CSCD 2019年第8期9-19,共11页
Over the past half a century, considerable research activities have been directing towards the development of magnetic semiconductors that can work at room temperature. These efforts were aimed at seeking room tempera... Over the past half a century, considerable research activities have been directing towards the development of magnetic semiconductors that can work at room temperature. These efforts were aimed at seeking room temperature magnetic semiconductors with strong and controllable s, p-d exchange interaction. With this s, p-d exchange interaction, one can utilize the spin degree of freedom to design applicable spintronics devices with very attractive functions that are not available in conventional semiconductors. Here, we first review the progress in understanding of this particular material and the dilemma to prepare a room temperature magnetic semiconductor. Then we discuss recent experimental progresses to pursue strong s, p-d interaction to realize room temperature magnetic semiconductors, which are achieved by introducing a very high concentration of magnetic atoms by means of low-temperature nonequilibrium growth. 展开更多
关键词 MAGNETIC SEMICONDUCTORS s p-d interaction high concentration of MAGNETIC ATOMS low temperature NONEQUILIBRIUM growth SEMICONDUCTOR SPINTRONICS
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Progress on microscopic properties of diluted magnetic semiconductors by NMR and μSR 预览
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作者 Yilun Gu Shengli Guo Fanlong Ning 《半导体学报:英文版》 EI CAS CSCD 2019年第8期57-63,共7页
Diluted magnetic semiconductors (DMSs) that possess both properties of semiconductors and ferromagnetism, have attracted a lot of attentions due to its potential applications for spin-sensitive electronic devices. Rec... Diluted magnetic semiconductors (DMSs) that possess both properties of semiconductors and ferromagnetism, have attracted a lot of attentions due to its potential applications for spin-sensitive electronic devices. Recently, a series of bulk form DMSs isostructural to iron-based superconductors have been reported, which can be readily investigated by microscopic experimental techniques such as nuclear magnetic resonance (NMR) and muon spin rotation (μSR). The measurements have demonstrated that homogeneous ferromagnetism is achieved in these DMSs. In this review article, we summarize experimental evidences from both NMR and μSR measurements. NMR results have shown that carriers facilitate the interactions between distant Mn atoms, while μSR results indicate that these bulk form DMSs and (Ga,Mn)As share a common mechanism for the ferromagnetic exchange interactions. 展开更多
关键词 DILUTED MAGNETIC SEMICONDUCTORS MUON spin rotation nuclear MAGNETIC resonance FERROMAGNETISM
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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
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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Magnetic field topology modeling under resonant magnetic perturbations on EAST
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作者 黄杰 铃木康浩 +6 位作者 梁云峰 贾曼妮 孙有文 楚南 许吉禅 吴木泉 EAST team 《等离子体科学与技术:英文版》 SCIE EI CAS CSCD 2019年第6期98-105,共8页
In order to understand the mechanism by which the resonant magnetic perturbation (RMP)mitigates or suppresses the edge-localized mode (ELM),the topological study of the edge magnetic field in ELM mitigation or suppres... In order to understand the mechanism by which the resonant magnetic perturbation (RMP)mitigates or suppresses the edge-localized mode (ELM),the topological study of the edge magnetic field in ELM mitigation or suppression phase is a critical issue.To model the three-dimensional magnetic field topology superposed RMP on Experimental Advanced Superconducting Tokamak,a numerical model using the field line tracing method for both vacuum and ideal plasma response approximations is proposed.Using the numerical model,the topological change and the penetration depth of the stochastic field lines in the edge magnetic field are studied in an RMP experiment.Comparing profiles of minimum9 on edge stochastic field lines and the particle flux pattem,the ideal plasma response changes the field line penetration depth while remaining similar profile relative to vacuum approximation.To mitigate and suppress ELM strongly,the deep penetration of RMP fields and topological changes of the edge magnetic field is a key from our modeling. 展开更多
关键词 MAGNETIC topology IDEAL plasma response TOKAMAKS RESONANT MAGNETIC PERTURBATION
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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Highly efficient and flexible preparation of water-dispersed Fe3O4 nanoclusters using a micromixer
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作者 Xiaojing Liu Yangcheng Lu 《颗粒学报:英文版》 SCIE EI CAS CSCD 2019年第4期42-48,共7页
Solvent exchange is widely used to synthesize magnetic nanoclusters (MNCs).However,it remains a challenge to increase the production and decrease the addition ofsurfactants,both of which are important for the applicat... Solvent exchange is widely used to synthesize magnetic nanoclusters (MNCs).However,it remains a challenge to increase the production and decrease the addition ofsurfactants,both of which are important for the application and functionalization of MNCs.Herein,we use a rapid and tunable mixing method to control the assembly of Fe3O4 nanoparticles.This method involves shear-mixing in a channel of a Tjunction micromixer.Smaller and more monodisperse MNCs were synthesized with less surfactant,when compared with conventional bulk synthesis.Varying the mixing rate and the formula of the magnetic suspension allowed for the flexible adjustment of the nanocluster size while maintaining a uniformly sized MNCs.The flow synthesis and ease of scale-up make this method potentially suitable for broad industrial application. 展开更多
关键词 FE3O4 MAGNETIC nanoparticle MAGNETIC NANOCLUSTER Micromixer-assisted continuous SYNTHESIS Bulk SYNTHESIS
Experimental Realization of an Intrinsic Magnetic Topological Insulator
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作者 龚演 郭景文 +21 位作者 李佳恒 朱科静 廖孟涵 刘效治 张庆华 谷林 唐林 冯硝 张定 李渭 宋灿立 王立莉 于浦 陈曦 王亚愚 姚宏 段文晖 徐勇 张首晟 马旭村 薛其坤 何珂 《中国物理快报:英文版》 SCIE CAS CSCD 2019年第7期66-71,共6页
An intrinsic magnetic topological insulator(TI) is a stoichiometric magnetic compound possessing both inherent magnetic order and topological electronic states. Such a material can provide a shortcut to various novel ... An intrinsic magnetic topological insulator(TI) is a stoichiometric magnetic compound possessing both inherent magnetic order and topological electronic states. Such a material can provide a shortcut to various novel topological quantum effects but remained elusive experimentally for a long time. Here we report the experimental realization of thin films of an intrinsic magnetic TI, MnBi2Te4, by alternate growth of a Bi2Te3 quintuple layer and a MnTe bilayer with molecular beam epitaxy. The material shows the archetypical Dirac surface states in angle-resolved photoemission spectroscopy and is demonstrated to be an antiferromagnetic topological insulator with ferromagnetic surfaces by magnetic and transport measurements as well as first-principles calculations. The unique magnetic and topological electronic structures and their interplays enable the material to embody rich quantum phases such as quantum anomalous Hall insulators and axion insulators at higher temperature and in a well-controlled way. 展开更多
关键词 INTRINSIC MAGNETIC STOICHIOMETRIC MAGNETIC well-controlled WAY
两种方法摘出眼内磁性异物的效果比较
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作者 高燕 原莉莉 +1 位作者 张东昌 李冬平 《中华眼外伤职业眼病杂志》 2019年第8期576-579,共4页
目的比较眼内磁性异物摘出的两种不同方法的效果。方法回顾性分析本院2016年1月至2017年12月165例眼内磁性异物摘出手术的资料。患者随机分为两组:A组89例由原伤口以磁铁吸引摘出,B组76例经玻璃体摘出。术后随访12~15个月进行分析。结... 目的比较眼内磁性异物摘出的两种不同方法的效果。方法回顾性分析本院2016年1月至2017年12月165例眼内磁性异物摘出手术的资料。患者随机分为两组:A组89例由原伤口以磁铁吸引摘出,B组76例经玻璃体摘出。术后随访12~15个月进行分析。结果术后A组视力提高64眼(71.91%),视力不变6眼(6.74%),B组视力提高66眼(86.89%),视力不变7眼(9.21%),两组视力提高率比较,差异无统计学意义(χ2=0.055,P=0.801)。结论两种摘出方法效果相似。 展开更多
关键词 异物 眼内 磁性 摘出术 磁吸 原伤口 摘出术 经玻璃体
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