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氧化锌压敏陶瓷脉冲放电特性研究进展 预览
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作者 解光勇 尹帅帅 +2 位作者 武孟媛 张扬 徐含馨 《功能材料》 EI CAS CSCD 北大核心 2019年第2期2001-2005,共5页
氧化锌(ZnO)压敏陶瓷材料具有非线性指数值高、响应时间短、漏电流小、通流能力强和性价比高等优点,因而被广泛应用于各种电路的过压保护。ZnO压敏电阻快脉冲放电特性的研究对材料的制备及其应用具有重要的意义。分析了ZnO压敏陶瓷材料... 氧化锌(ZnO)压敏陶瓷材料具有非线性指数值高、响应时间短、漏电流小、通流能力强和性价比高等优点,因而被广泛应用于各种电路的过压保护。ZnO压敏电阻快脉冲放电特性的研究对材料的制备及其应用具有重要的意义。分析了ZnO压敏陶瓷材料的微观结构形貌及物理模型;比较了基于电磁脉冲发生器、空气隙开关和脉冲整形装置技术的ZnO压敏陶瓷放电特性研究方法;讨论了8/20μs电磁脉冲和陡波脉冲激励下材料的击穿放电特性;提出了研究纳秒量级及更快电脉冲激励下的ZnO压敏陶瓷导电特性的问题。 展开更多
关键词 氧化锌 压敏陶瓷 脉冲激励 放电 导电特性
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Theoretical analysis of cross-plane lattice thermal conduction in graphite
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作者 顾云风 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第6期317-323,共7页
A theoretical analysis of the cross-plane lattice thermal conduction in graphite is performed by using first-principles calculations and in the single-mode relaxation time approximation. The out-of-plane phonon acoust... A theoretical analysis of the cross-plane lattice thermal conduction in graphite is performed by using first-principles calculations and in the single-mode relaxation time approximation. The out-of-plane phonon acoustic mode ZA and optical mode ZO have almost 80% and 20% of contributions to cross-plane heat transfer, respectively. However, these two branches have a small part of total specific heat above 300 K. Phonons in the central 16% of Brillouin zone contribute80% of cross-plane transport. If the group velocity angle with respect to the graphite layer normal is less than 30?, then the contribution is 50% at 300 K. The ZA phonons with long cross-plane mean free path are focused in the cross-plane direction, and the largest mean free path is on the order of several micrometers at room temperature. The average value of cross-plane mean free path at 300 K is 112 nm for ZA phonons with group velocity angle with respect to the layer normal being less than 15?. The average value is dropped to 15 nm when phonons of all branches in the whole Brillouin zone are taken into account, which happens because most phonons have small or even no contributions. 展开更多
关键词 GRAPHITE cross-plane thermal conduction PHONON mean free path LAYERED systems
2018年热超构材料研发热点回眸
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作者 黄吉平 《科技导报》 CAS CSCD 北大核心 2019年第1期99-105,共7页
热超构材料研发活动在2018年再次取得丰硕的研究成果。回顾了热超构材料2018年在热传导、热对流、热辐射3种传热方式方面的研究进展及应用,归纳为7个研究热点:结构表面高效调控热传导、非均匀热学结构理论进展及应用开发、热学零折射隐... 热超构材料研发活动在2018年再次取得丰硕的研究成果。回顾了热超构材料2018年在热传导、热对流、热辐射3种传热方式方面的研究进展及应用,归纳为7个研究热点:结构表面高效调控热传导、非均匀热学结构理论进展及应用开发、热学零折射隐身斗篷、建立了变换热对流理论、反常对流传热现象、从太阳和太空中同步收集能量、热超构材料应用设计与集成开发。 展开更多
关键词 变换热学 热学器件 热传导 热对流 热辐射
Use of improved cold-finger technique to assess effects of basicity on heat transfer through solidified mold flux
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作者 Karina Lara Santos Assis Petrus Christiaan Pistorius 《钢铁研究学报:英文版》 SCIE EI CAS CSCD 2019年第4期393-402,共10页
Cold-finger measurements were used to estimate the contact resistance and average thermal conductivity of mold flux films solidified on a water-cooled copper probe.Five industrial mold fluxes,with basicities from low ... Cold-finger measurements were used to estimate the contact resistance and average thermal conductivity of mold flux films solidified on a water-cooled copper probe.Five industrial mold fluxes,with basicities from low to high,were tested.The steady-state rate of convective heat transfer between the solid film and liquid flux was compared with calculations based on natural convection correlations;the comparison indicates that the surface of the solid film(in contact with molten flux)is approximately at its solidus temperature.The roughness of the mold flux film in contact with copper was larger for films grown from higher-temperature mold flux and for higher-basicity mold fluxes.The glassy(low-basicity)film had an estimated thermal conductivity of 1.1 W/(m K).The crystalline or partially crystalline films had higher estimated thermal conductivities of 2.2-3.2 W/(m K).The measured values of thermal resistance were extrapolated to typical mold flux film thicknesses for industrial conditions;the extrapolations confirmed that the high contact resistance of higher-basicity mold fluxes can yield higher thermal resistances than the low-basicity flux.The morphology of the rough interface of higherbasicity mold flux films that gives the higher contact resistance is consistent with that observed in previous work and appears not to be directly related to crystallization. 展开更多
关键词 MOLD flux Heat transfer Conduction Contact resistance-Cold-finger TECHNIQUE
Stochastic dynamics of conduction failure of action potential along nerve fiber with Hopf bifurcation
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作者 ZHANG XinJing GU HuaGuang GUAN LiNan 《中国科学:技术科学英文版》 SCIE EI CAS CSCD 2019年第9期1502-1511,共10页
Action potentials can be induced by external electronic impulsive stimulations applied at one end of the unmyelinated fibers(C-fibers), while some action potentials fail to conduct to the other end of the fiber when t... Action potentials can be induced by external electronic impulsive stimulations applied at one end of the unmyelinated fibers(C-fibers), while some action potentials fail to conduct to the other end of the fiber when the stimulation frequency becomes high. Such a phenomenon is called as conduction failure, which was observed in the biological experiments and related to the painful diabetic neuropathy, inflammation, and trauma in the previous studies. On-off firing pattern was recorded from the fiber when conduction failure happened. In the present study, the diffusion Hodgkin-Huxley(HH) model with resting state near a Hopf bifurcation is adopted to simulate the experimental observations. When the periodic electrical pulses with high frequency are applied to one end of the fiber described by the deterministic HH model, conduction failure and the corresponding firing patterns different from the on-off firing pattern are simulated. When noise is introduced to form the stochastic HH model, the firing pattern corresponding to conduction failure becomes the on-off firing pattern, which is characterised by transition behaviors between on-phase(continuous action potentials) and off-phase(a long quiescent state) and large variations in the durations of both phases. Furthermore, the increase of potassium conductance can enhance the conduction failure degree, which closely matches those observed in the experiment and is suggested to be related to the reduction of pain signals. The results show that noise is an important factor to evoke the on-off firing pattern, reveal the functional capability in the pain signals propagation along C-fiber,and present a possible measure for the treatment of chronic pain. 展开更多
关键词 neural FIRING conduction FAILURE HOPF bifurcation periodic pulse STIMULUS C-FIBER
注干用10%甲氨基阿维菌素苯甲酸盐可溶粒剂的研制及对松材线虫病的防治效果
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作者 张欣伟 韩群琦 +2 位作者 汪天娜 吴利平 陈安良 《农药学学报》 CAS CSCD 北大核心 2019年第4期538-544,共7页
为有效防治松材线虫病,研制了注干用10%甲氨基阿维菌素苯甲酸盐(以下简称甲维盐)可溶粒剂,并通过在马尾松树干基部钻孔施药,考察了其对松材线虫病的防治效果。以苯甲酸钠、单水乳糖、可溶性淀粉和羧甲基纤维素为水溶性载体,采用混料均... 为有效防治松材线虫病,研制了注干用10%甲氨基阿维菌素苯甲酸盐(以下简称甲维盐)可溶粒剂,并通过在马尾松树干基部钻孔施药,考察了其对松材线虫病的防治效果。以苯甲酸钠、单水乳糖、可溶性淀粉和羧甲基纤维素为水溶性载体,采用混料均匀试验设计及偏最小二乘回归分析法对水溶性载体的配方进行了优化。将水溶性载体与溶于正丁醇和乳化剂OP-10的甲维盐(油相)在不同时间下混合并造粒,通过对其性能指标的追踪检测得出粒剂最佳配比和混合时间。结果表明:10%甲维盐可溶粒剂的最佳配比(质量分数)为:甲维盐10.0%(折纯),乳化剂OP-10 6.7%,正丁醇12.0%,苯甲酸钠39.0%,单水乳糖20.5%,水溶性淀粉3.0%和羧甲基纤维素4.5%;机械混合时间为10 min,粒剂外观为乳白色圆柱体,各项性能指标合格。注干施药结果表明:在浙江临安东湖村松材线虫病疫区,注干110棵马尾松,1 a后马尾松死亡率为0,对照区为6.1%;在福建泉州仙公山疫区,注干230棵马尾松,1 a后马尾松死亡率为1.7%,对照区10.8%。结果表明,所研制的10%甲维盐可溶粒剂可在松脂分泌旺盛的松树上注干施药,制剂造粒工艺简单,无包装物污染,对松材线虫病防治效果显著。 展开更多
关键词 注干施药 甲氨基阿维菌素苯甲酸盐 可溶粒剂 松材线虫病 传导性 防治效果
The dimension splitting element-free Galerkin method for 3D transient heat conduction problems
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作者 ZhiJuan Meng Heng Cheng +1 位作者 LiDong Ma YuMin Cheng 《中国科学:物理学、力学、天文学英文版》 SCIE EI CAS CSCD 2019年第4期45-56,共12页
By transforming a 3D problem into some related 2D problems, the dimension splitting element-free Galerkin(DSEFG) method is proposed to solve 3D transient heat conduction problems. The improved element-free Galerkin(IE... By transforming a 3D problem into some related 2D problems, the dimension splitting element-free Galerkin(DSEFG) method is proposed to solve 3D transient heat conduction problems. The improved element-free Galerkin(IEFG) method is used for 2D transient heat conduction problems, and the finite difference method is applied in the splitting direction. The discretized system equation is obtained based on the Galerkin weak form of 2D problem;the essential boundary conditions are imposed with the penalty method;and the finite difference method is employed in the time domain. Four exemplary problems are chosen to verify the efficiency of the DSEFG method. The numerical solutions show that the efficiency and precision of the DSEFG method are greater than ones of the IEFG method for 3D problems. 展开更多
关键词 improved element-free GALERKIN (IEFG) METHOD DIMENSION SPLITTING METHOD finite DIFFERENCE METHOD DIMENSION SPLITTING element-free GALERKIN (DSEFG) METHOD TRANSIENT heat conduction problem
A rare case of Staphylococcus lugdunensis septicemia associated with myocarditis and atrioventricular block 预览
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作者 Alex Tsz Lai Nganh Sharen Lee +6 位作者 Tong LIU Mark Tam Ka Hou Christien Li Michelle Vangi Wong Michael Huen Sum Lam Gary Tse Ishan Lakhani 《老年心脏病学杂志:英文版》 SCIE CAS CSCD 2019年第1期63-66,共4页
Myocarditis is a relatively rare,possibly life-threatening disease characterized by the inflammation of the myocardium.111 The disease pathogenesis is primarily initiated by acute injury and necrosis of cardiomyocytes... Myocarditis is a relatively rare,possibly life-threatening disease characterized by the inflammation of the myocardium.111 The disease pathogenesis is primarily initiated by acute injury and necrosis of cardiomyocytes,leading to an inflammatory response mediated by the immune system that can potentially cause further aggravation of myocardial damage and organ dysfunction.Prognosis in patients with myocarditis depends on the clinical presentation,which ranges from an asymptomatic disease course to the concomitant development of cardiac arrhythmias,heart failure,cardiogenic shock and even the occurrence of death in extreme cases[1]. 展开更多
关键词 Atrioventricular BLOCK Conduction INFLAMMATION MYOCARDITIS STAPHYLOCOCCUS lugdunensis
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Growth of high quality Sr2IrO4 epitaxial thin films on conductive substrates
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作者 徐珲 崔璋璋 +1 位作者 翟晓芳 陆亚林 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第7期490-494,共5页
Ruddlesden–Popper iridium oxides have attracted considerable interest because of the many proposed novel quantum states that arise from the large spin–orbit coupling of the heavy iridium atoms in them.A prominent ex... Ruddlesden–Popper iridium oxides have attracted considerable interest because of the many proposed novel quantum states that arise from the large spin–orbit coupling of the heavy iridium atoms in them.A prominent example is the single layer Sr2IrO4, in which superconductivity has been proposed under electron doping.However, the synthesis of Sr2IrO4 high quality thin films has been a huge challenge due to the easy formation of impurities associated with different numbers of SrO layers.Thus techniques to optimize the growth of pure phase Sr2IrO4 are urgently required.Here we report the deposition of high quality Sr2IrO4 thin films on both insulating SrTiO3 and conducting SrTiO3:Nb substrates using pulsed laser deposition assisted with reflective high-energy electron diffraction.The optimal deposition temperature of Sr2IrO4 epitaxial films on SrTiO3:Nb substrates is about 90℃ lower than that on SrTiO3 substrates.The electrical transports of high quality Sr2IrO4 films are measured, which follow the three-dimensional Mott variable-range hopping model.The film magnetizations are measured, which show weak ferromagnetism below ~240 K with a saturation magnetization of~ 0.2 μB/Ir at 5 K.This study provides applicable methods to prepare high quality 5 d Sr2IrO4 epitaxial films, which could be extended to other Ruddlesden–Popper phases and potentially help the future study of exotic quantum phenomena in them. 展开更多
关键词 SUBSTRATES PULSED LASER DEPOSITION iridates conduction mechanism
Transdermal delivery of 4-aminopyridine accelerates motor functional recovery and improves nerve morphology following sciatic nerve crush injury in mice 预览
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作者 Andrew RClark Chia George Hsu +2 位作者 M A Hassan Talukder Mark Noble John CElfar 《中国神经再生研究:英文版》 SCIE CAS CSCD 2020年第1期136-144,共9页
Oral 4-aminopyridine(4-AP)is clinically used for symptomatic relief in multiple sclerosis and we recently demonstrated that systemic 4-AP had previously unknown clinically-relevant effects after traumatic peripheral n... Oral 4-aminopyridine(4-AP)is clinically used for symptomatic relief in multiple sclerosis and we recently demonstrated that systemic 4-AP had previously unknown clinically-relevant effects after traumatic peripheral nerve injury including the promotion of re-myelination,improvement of nerve conductivity,and acceleration of functional recovery.We hypothesized that,instead of oral or injection administration,transdermal 4-AP(TD-4-AP)could also improve functional recovery after traumatic peripheral nerve injury.Mice with surgical traumatic peripheral nerve injury received TD-4AP or vehicle alone and were examined for skin permeability,pharmacokinetics,functional,electrophysiological,and nerve morphological properties.4-AP showed linear pharmacokinetics and the maximum plasma 4-AP concentrations were proportional to TD-4-AP dose.While a single dose of TD-4-AP administration demonstrated rapid transient improvement in motor function,chronic TD-4-AP treatment significantly improved motor function and nerve conduction and these effects were associated with fewer degenerating axons and thicker myelin sheaths than those from vehicle controls.These findings provide direct evidence for the potential transdermal applicability of 4-AP and demonstrate that 4-AP delivered through the skin can enhance in-vivo functional recovery and nerve conduction while decreasing axonal degeneration.The animal experiments were approved by the University Committee on Animal Research(UCAR)at the University of Rochester(UCAR-2009-019)on March 31,2017. 展开更多
关键词 4-AMINOPYRIDINE electron microscopy functional recovery nerve conduction velocity peripheral nerve injury PHARMACOKINETICS transdermal administration
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Towards Improvement of Photovoltaic Performance of Aqueous Dye-sensitized Solar Cells by Tungsten-doped Mesoporous Nanobeads TiO2 Working Electrode
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作者 郭言荣 ZOU Tingting +2 位作者 CHENG Qin JIAO Binqing 张晓俐 《武汉理工大学学报:材料科学英文版》 SCIE EI CAS 2019年第1期17-22,共6页
Tungsten doped(W-doped) TiO2 mesoporous nanobeads, possessing high surface area and superior scattering effect, were used for photoanode preparation. The W-doping would induce a positive shift of the TiO2 conduction b... Tungsten doped(W-doped) TiO2 mesoporous nanobeads, possessing high surface area and superior scattering effect, were used for photoanode preparation. The W-doping would induce a positive shift of the TiO2 conduction band, and enhance the driving force for electron injection and collection efficiencies. The electrochemical impedance spectra indicated a retarded charge recombination and increased electron diffusion length after W-doping. By fine-tuning the W-doping concentration to 0.25%, aqueous DSCs produced a significant improved the open circuit voltage of 712 mV and a short circuit current of 7.05 mA·cm-2, leading to an overall increased power conversion efficiency of 3.40% at 1 000 W·m-2 simulated irradiation, which is roughly 25% enhancement compared to that without W-doping photoanode. 展开更多
关键词 tungsten-doping DYE-SENSITIZED solar cells AQUEOUS ELECTROLYTE conduction band
Efficacy of autologous bone marrow mononuclear cell transplantation therapy in patients with refractory diabetic peripheral neuropathy
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作者 Hong Mao Wei Wei +5 位作者 Xiu-Li Fu Jing-Jian Dong Xiao-Yu Lyu Ting Jia Yang Tang Shi Zhao 《中华医学杂志:英文版》 SCIE CAS CSCD 2019年第1期11-16,共6页
Background:Owing to the multifactorial nature of the pathogenesis of diabetic peripheral neuropathy (DPN),conventional drug therapies have not been effective.The application of stem cells transplantation may be useful... Background:Owing to the multifactorial nature of the pathogenesis of diabetic peripheral neuropathy (DPN),conventional drug therapies have not been effective.The application of stem cells transplantation may be useful for the treatment of DPN.This study was designed to assess the safety and therapeutic effects of autologous bone marrow mononuclear cells (BMMNCs) transplantation on the treatment of refractory DPN.Methods:One hundred and sixty-eight patients with refractory DPN were recruited and enrolled in the study.They received intramuscular injection of BMMNCs and followed at 1,3,6,12,18,24,and 36 months after the transplantation.Clinical data,Toronto Clinical Scoring System (TCSS),and nerve conduction studies (NCSs) were compared before and after the transplantation.Results:The signs and symptoms of neuropathy were significantly improved after BMMNCs transplantation.The values of the TCSS scores at 1 month (9.68 ± 2.49 vs.12.55 ± 2.19,P<0.001) and 3 months (8.47 ± 2.39 vs.12.55 ± 2.19,P<0.001) after the treatment reduced significantly compared with the baseline value.This decrement remained persistent until the end of the study.The conduction velocity and action potential and sensory nerves were significantly improved after transplantation (3 and 12 months after the treatment vs.the baseline:motor nerve conduction velocity,40.24 ± 2.80 and 41.00 ± 2.22 m/s vs.38.21 ± 2.28 m/s,P<0.001;sensory nerve conduction velocity,36.96 ± 2.26 and 39.15 ± 2.61 m/s vs.40.41 ± 2.22 m/s,P<0.001;compound muscle action potential,4.67 ± 1.05 and 5.50 ± 1.20 μV vs.5.68 ± 1.08 μV,P<0.001;sensory nerve action potential,4.29 ± 0.99 and 5.14 ± 1.26 μV vs.5.41 ± 1.14 μV,P<0.001).No adverse event associated with the treatment was observed during the follow-up period.Conclusions:Autologous transplantation of BMMNCs may be an effective and promising therapeutic strategy for the treatment of refractory DPN. 展开更多
关键词 Bone marrow MONONUCLEAR cells diabetic peripheral NEUROPATHY AUTOLOGOUS TRANSPLANTATION TORONTO clinical SCORING system nerve conduction
Modeling and Dynamic Analysis of Fractional-Order Buck Converter in Continuous Conduction Mode 预览
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作者 Dawei Ding Zongzhi Li Nian Wang 《哈尔滨工业大学学报:英文版》 EI CAS 2019年第4期58-68,共11页
According to the fact that the actual inductor and actual capacitor are fractional, the mathematical and state-space averaging models of fractional order Buck converters in continuous conduction mode(CCM) are construc... According to the fact that the actual inductor and actual capacitor are fractional, the mathematical and state-space averaging models of fractional order Buck converters in continuous conduction mode(CCM) are constructed by using fractional calculus theory. Firstly, the parameter conditions that ensure that the converter working in CCM is given and transfer functions are derived. Also, the inductor current and the output voltage are analyzed. Then the difference between the mathematical model and the circuit model are analyzed, and the effect of fractional order is studied by comparing the integer order with fractional order model. Finally, the dynamic behavior of the current-controlled Buck converter is investigated. Simulation experiments are achieved via the use of Matlab/Simulink. The experimental results verify the correctness of theoretical analysis, the order should be taken as a significant parameter. When the order is taken as a bifurcation parameter, the dynamic behavior of the converter will be affected and bifurcation points will be changed as order varies. 展开更多
关键词 BUCK converter FRACTIONAL order continuous conduction mode(CCM) MODELING dynamic analysis BIFURCATION
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Atomic-layer-deposited (ALD) Al2O3 passivation dependent interface chemistry, band alignment and electrical properties of HfYO/Si gate stacks
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作者 Shuang Liang Gang He +1 位作者 Die Wang Fen Qiao 《材料科学技术学报:英文版》 SCIE EI CAS CSCD 2019年第5期769-776,共8页
In this work, the effects of atomic-layer-deposited(ALD) Al2O3 passivation layers with different thicknesses on the interface chemistry and electrical properties of sputtering-derived HfYO gate dielectrics on Si subst... In this work, the effects of atomic-layer-deposited(ALD) Al2O3 passivation layers with different thicknesses on the interface chemistry and electrical properties of sputtering-derived HfYO gate dielectrics on Si substrates have been investigated. The results of electrical measurements and X-ray photoelectron sepectroscopy(XPS) showed that 1-nm-thick Al2O3 passivation layer is optimized to obtain excellent electrical and interfacial properties for HfYO/Si gate stack. Then, the metal-oxide-semiconductor capacitors with HfYO/1-nm Al2O3/Si/Al gate stack were fabricated and annealed at different temperatures in forming gas(95% N2+5% H2). Capacitance-voltage(C-V) and current density-voltage(J-V) characteristics showed that the 250℃-annealed HYO high-k gate dielectric thin film demonstrated the lowest border trapped oxide charge density(-3.3 × 1010 cm-2), smallest gate-leakage current(2.45 × 10-6 A/cm2 at 2 V)compared with other samples. Moreover, the annealing temperature dependent leakage current conduction mechanism for Al/HfYO/Al2O3/Si/Al MOS capacitor has been investigated systematically. Detailed electrical measurements reveal that Poole-Frenkle emission is the main dominant emission in the region of low and medium electric fields while direct tunneling is dominant conduction mechanism at high electric fields. 展开更多
关键词 Al2O3passivation LAYER Co-sputtering HYO films Annealing ELECTRICAL properties Conduction mechanism
Causes of geothermal fields and characteristics of ground temperature fields in China 预览
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作者 MAO Xiao-ping LI Ke-wen WANG Xin-wei 《地下水科学与工程:英文版》 2019年第1期15-28,共14页
There are many arguments on energy sources and main controlling factors of geothermal fields, so a systematic study on the distribution of ground temperature fields shall be necessary. In this paper the thermal conduc... There are many arguments on energy sources and main controlling factors of geothermal fields, so a systematic study on the distribution of ground temperature fields shall be necessary. In this paper the thermal conduction forward method of geothermal field is used to simulate cooling rate of abnormal heat sources and heat transfer of the paleo-uplift model. Combined with a large number of geothermal field exploration cases and oil exploration well temperature curves of domestic and foreign, the following conclusions are drawn:(1) According to the magmatic activity time, the magmatism activities are divided into two categories: Magma active areas (activity time < 500 000 years) and weak/magma inactive areas (activity time > 500 000 years). The latter has a fast cooling rate (the cooling time of the magma pocket buried around 10 km is less than 200 000 years) after it has intruded into the shallow layer and it has no direct contribution to modern geothermal fields;(2) China belongs to a weak/magma inactive area such as Tengchong region and Qinghai-Tibet region because the chronological data of these regions show that its magma activity time is more than 500 000 years;(3) The temperature of most geothermal fields can be obviously divided into three segments in the vertical direction: A high geothermal gradient segment (Segment H) at the surface, then a low geothermal gradient segment (Segment L) at a secondary depth, and finally a lower temperature segment (Segment D) at a deeper depth. The temperature isoline presents a mirror reflection relation on the temperature profile, indicating that geothermal field is dominated by heat conduction, rather than having an abnormally high temperature “heat source” to provide heat;(4) Near-surface (0-5 km) materials’ lateral heterogeneity caused by tectonic movement shall probably be the main controlling factor of ground temperature fields. 展开更多
关键词 Ground temperature FIELD BASEMENT HEAT flow GEOTHERMAL FIELD MAGMA pocket Coefficient of HEAT conduction Palaeouplifth MAGNETOTELLURIC
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Study on the correlation between apolipoprotein A1 and apolipoprotein B and carotid-femoral pulse wave velocity
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作者 Xiao-Xiao Zhao Huan Liu +2 位作者 Jin-Bo Liu Hong-Wei Zhao Hong-Yu Wang 《海南医科大学学报(英文版)》 2019年第12期1-6,共6页
Objective:To explore the association between lipoprotein and arteriosclerosis in hospitalized and outpatient populations in western Beijing.Methods:Patients enrolled in the outpatient department and hospitalization fr... Objective:To explore the association between lipoprotein and arteriosclerosis in hospitalized and outpatient populations in western Beijing.Methods:Patients enrolled in the outpatient department and hospitalization from January 2013 to December 2017 were selected and eventually 258 cases were included in the study according to strict enrollment and exclusion criteria. The data were true and reliable. Statistically, an independent sample t-test and correlation analysis method were used, and the receiver operating characteristic curve was plotted using the predicted values of apolipoprotein A1 and apolipoprotein B for arteriosclerosis by controlling confounding factors.Results: Correlation analysis showed that there was a significant correlation between apolipoprotein B (P=0.007, correlation coefficient: -0.203) and carotid-femoral pulse wave velocity. Apolipoprotein A1 and apolipoprotein B had a strong diagnostic value for arteriosclerosis in patients without coronary heart disease. Conclusions: There is a significant negative correlation between apolipoprotein B and carotid-pulse wave velocity in the unconflicted patients in this study. Apolipoprotein A1 and apolipoprotein B have diagnostic value for arteriosclerosis. 展开更多
关键词 CARDIOLOGY APOLIPOPROTEIN CORRELATION analysis ARTERIOSCLEROSIS Carotid-pulse wave conduction velocity
Unifying quantum heat transfer and superradiant signature in a nonequilibrium collective-qubit system:A polaron-transformed Redfield approach
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作者 陈许敏 王晨 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第5期48-56,共9页
We investigate full counting statistics of quantum heat transfer in a collective-qubit system constructed by multiqubits interacting with two thermal baths.The nonequilibrium polaron-transformed Redfield approach embe... We investigate full counting statistics of quantum heat transfer in a collective-qubit system constructed by multiqubits interacting with two thermal baths.The nonequilibrium polaron-transformed Redfield approach embedded with an auxiliary counting field is applied to obtain the steady state heat current and fluctuations,which enables us to study the impact of the qubit–bath interaction in a wide regime.The heat current,current noise,and skewness are all found to clearly unify the limiting results in the weak and strong couplings.Moreover,the superradiant heat transfer is clarified as a system-size-dependent effect,and large number of qubits dramatically suppress the nonequilibrium superradiant signature. 展开更多
关键词 QUANTUM transport heat conduction PHONONS or vibrational states in LOW-DIMENSIONAL structures and nanoscale materials NONEQUILIBRIUM and IRREVERSIBLE thermodynamics
Qian-Zheng-San promotes regeneration after sciatic nerve crush injury in rats 预览
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作者 Zhi-Yong Wang Li-Hua Qin +2 位作者 Wei-Guang Zhang Pei-Xun Zhang Bao-Guo Jiang 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第4期683-691,共9页
Qian-Zheng-San,a traditional Chinese prescription consisting of Typhonii Rhizoma,Bombyx Batryticatus,Scorpio,has been found to play an active therapeutic role in central nervous system diseases.However,it is unclear w... Qian-Zheng-San,a traditional Chinese prescription consisting of Typhonii Rhizoma,Bombyx Batryticatus,Scorpio,has been found to play an active therapeutic role in central nervous system diseases.However,it is unclear whether Qian-Zheng-San has therapeutic value for peripheral nerve injury.Therefore,we used Sprague-Dawley rats to investigate this.A sciatic nerve crush injury model was induced by clamping the right sciatic nerve.Subsequently,rats in the treatment group were administered 2 mL Qian-Zheng-San(1.75 g/mL)daily as systemic therapy for 1,2,4,or 8 weeks.Rats in the control group were not administered Qian-Zheng-San.Rats in sham group did not undergo surgery and systemic therapy.Footprint analysis was used to assess nerve motor function.Electrophysiological experiments were used to detect nerve conduction function.Immunofluorescence staining was used to assess axon counts and morphological analysis.Immunohistochemical staining was used to observe myelin regeneration of the sciatic nerve and the number of motoneurons in the anterior horn of the spinal cord.At 2 and 4 weeks postoperatively,the sciatic nerve function index,nerve conduction velocity,the number of distant regenerated axons and the axon diameter of the sciatic nerve increased in the Qian-Zheng-San treatment group compared with the control group.At 2 weeks postoperatively,nerve fiber diameter,myelin thickness,and the number of motor neurons in the lumbar spinal cord anterior horn increased in the Qian-Zheng-San treatment group compared with the control group.These results indicate that Qian-Zheng-San has a positive effect on peripheral nerve regeneration. 展开更多
关键词 NERVE REGENERATION traditional Chinese medicine CRUSH INJURY peripheral NERVE REGENERATION NERVE conduction velocity SCIATIC function index NERVE INJURY NERVE repair formula SCORPION neural REGENERATION
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麻醉方式对高龄髋关节骨折术后心肺并发症的影响
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作者 白冰 阮侠 +5 位作者 张越伦 陈棣 金欣星 田园 唐帅 黄宇光 《中华医学杂志》 CSCD 北大核心 2018年第40期3240-3243,共4页
目的比较不同麻醉方式对接受单侧髋关节骨折手术且年龄≥80岁的高龄患者术后心肺并发症的影响。方法收集2009年7月至2014年6月在北京协和医院接受单侧髋关节骨折手术且年龄≥80岁患者的围手术期资料,根据麻醉方式分为全身麻醉组、椎管... 目的比较不同麻醉方式对接受单侧髋关节骨折手术且年龄≥80岁的高龄患者术后心肺并发症的影响。方法收集2009年7月至2014年6月在北京协和医院接受单侧髋关节骨折手术且年龄≥80岁患者的围手术期资料,根据麻醉方式分为全身麻醉组、椎管内麻醉组、神经阻滞组。记录3组患者术前一般情况(年龄、性别、骨折类型、ASA分级、术前心肺合并症),术中情况(手术类型、手术时间、出血量、术中输液总量),以及术后情况(住院天数、术后住院天数、ICU停留时间、术后新发心肺并发症、术后院内死亡、住院费用),并分析不同麻醉方式对高龄患者髋关节骨折术后心肺并发症的影响。结果经检索,共219份病历符合纳入标准,分别为全身麻醉组(n=46)、椎管内麻醉组(n=90)、神经阻滞组(n=83)。除全身麻醉组中术前有肺部合并症的患者比例(15例,32.6%)明显低于椎管内麻醉组(45例,50%)和神经阻滞组(47例,56.6%)之外(X^2=6.912,P=0.032),3组术前心血管合并症及其余指标差异均无统计学意义(均P〉0.05)。3组术后心肺并发症发生率差异无统计学意义。椎管内麻醉组和神经阻滞组的住院总费用分别为(4.56±2.14)万元和(4.82±2.58)万元,显著低于全身麻醉组的(5.63±2.16)万元,差异有统计学意义(F=9.951,P=0.007)。结论对于高龄接受单侧髋关节手术的患者,麻醉方式不影响术后心肺并发症的发生率,椎管内麻醉和神经阻滞可以降低住院费用。 展开更多
关键词 老年人 髋关节 外科手术 手术后并发症 麻醉 传导
选择性脊髓麻醉动物模型的复制 预览
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作者 张鹏 李耀 叶菱 《中国现代医学杂志》 2018年第34期1-5,共5页
目的利用乳化七氟烷独特药代动力学特点,用新西兰大白兔复制一种小动物选择性脊髓麻醉模型。方法选取16只雄性新西兰大白兔,分为动脉组和静脉组。动脉组经腹主动脉(T12~L1)导管按8ml/(kg·h)持续泵入8%乳化七氟烷;静脉组经右侧耳缘... 目的利用乳化七氟烷独特药代动力学特点,用新西兰大白兔复制一种小动物选择性脊髓麻醉模型。方法选取16只雄性新西兰大白兔,分为动脉组和静脉组。动脉组经腹主动脉(T12~L1)导管按8ml/(kg·h)持续泵入8%乳化七氟烷;静脉组经右侧耳缘静脉泵入相同剂量的乳化七氟烷。气相色谱仪和顶空二次平衡法测量颈动脉、颈静脉(代表脑)和股动脉、股静脉(代表脊髓)血液中七氟烷浓度和分压。结果静脉组动物不同部位血液中七氟烷浓度、分压比较差异无统计学意义(P>0.05)。动脉组颈动脉和颈静脉,股动脉和股静脉中七氟烷浓度、分压比较差异无统计学意义(P>0.05);动脉组股动脉和颈动脉,股静脉和颈静脉中七氟烷分压比较差异有统计学意义(P<0.05)。股动脉七氟烷分压是颈动脉的(3.26±0.37)倍;股静脉七氟烷分压是颈静脉的(3.87±0.85)倍。结论在保留新西兰大白兔脑和脊髓正常血液循环结构基础上,利用新西兰大白兔节段性脊髓血供特点和乳化七氟烷独特药代动力学模型,成功复制了一种小动物选择性脊髓(腰骶段)麻醉模型。 展开更多
关键词 麻醉 传导 模型 动物 七氟烷/麻醉药
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