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Lithium cobaltate:a novel host material enables high-rate and stable lithium-sulfur batteries

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Rare Metals 2018年第11期37卷 929-935页

作者： Wen Ma qing xu GRINM Bohan (Beijing) Publisher Co. Ltd.GRINM Group Co.Ltd. Subinstitute of Standardization Theory and Strategy China National Institute of Standardization

Element sulfur is highly attractive due to their potentially low cost and environmental ***, polysulfides dissolution hinders the lithiumsulfur(Li-S) batteries toward commercialization. To overcome these issues, in this work, lithium cobaltate as a commercial material, for the first time, was devoted to engineering the electrode structure and composition to improve the performance. When incorporated with 80% sulfur powder, the synergetic effects of cobalt atoms and interlayer spaces effectively enable the production of Li-S batteries with a relatively high discharge capacity of 1420 mAh·g-1at the low surface current density of 1 mA·cm-2and stable capacity retention of 650 mAh·g-1at high surface current density of 6 mA·cm-2. The introduction of lithium cobaltate is a viable approach for successfully developing practical Li-S batteries.

关键词： Lithium cobaltate Polysulfides dissolution Electrochemical properties Lithium-sulfur batteries

Biological impacts of "hot-spot" mutations of hepatitis B virus X proteins are genotype B and C differentiated

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World Journal of Gastroenterology 2005年第30期11卷 4703-4708页

作者： xu Lin Xiao xu qing-Ling Huang yu-qing Liu Da-Li Zheng Wan-Nan Chen Jian-Yin Lin Research Center of Molecular Medicine Fujian Medical University Fuzhou 350004 Fujian Province China Centre for the Study of Liver Disease and Department of Surgery The University of Hong Kong Pokfulam Hong Kong China

AIM: To investigate the biological impacts of 'hot-spot'mutations on genotype B and C HBV X proteins (HBx).METHODS: Five types of'hot-spot' mutations of genotype B or C HBV X genes, which sequentially lead to the amino acid substitutions of HBx as I127T, F132Y, K130M+V131I,I127T+K130M+V131I, or K130M+V131I+F132Y, respectively,were generated by means of site-directed *** evaluate the anti-proliferative effects, HBx or related mutants' expression vectors were transfected separately to the Chang cells by lipofectamine, and the cells were cultured in hygromycin selective medium for 14 d, drug-resistant colonies were fixed with cold methanol, stained with Giemsa dyes and scored (increase of the colonies indicated the reduction of the anti-proliferation activity,and vice versa). Different types of HBx expression vectors were co-transfected separately with the reporter plasmid pCMVβ to Chang cells, which were lysed 48 h post-transfection and the intra-cellular β-galactosidase activities were monitored (increase of the β-galactosidase activities indicated the reduction of the transactivation activity, and vice versa). All data obtained were calculated by paired-samples ***: As compared to standard genotype B HBx,mutants of I127T and I127T+K130M+V131I showed higher transactivation and anti-proliferative activities, while the mutants of F132Y, K130M+V131I, and K130M+V131I+F132Y showed lower activities. As compared to standard genotype C HBx, I127T mutant showed higher transactivation activity, while the other four types of mutants showed no differences. With regard to anti-proliferative activity,compared to standard genotype C HBx, F132Y and K130M+V131I mutants showed lower activities, and K130M+V131I +F132Y mutant, on the other hand, showed higher activity,while the mutants of I127T and I127T+K130M+V131I showed no ***: 'Hot-spot' mutations affect the antiproliferation and transactivation activities of genotype B and/or C HBx, and the

关键词： Hepatitis B virus Genotype X gene Mutation

电刺激诱导miR-741-3p调控Radil促进施万细胞的迁移

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中国组织工程研究 2025年第19期29卷 4038-4043页

作者：刘庆高博杨霄姜宇王培承德医学院附属医院河北省承德市067000 承德医学院河北省承德市067000

背景:越来越多的动物实验和临床研究证实电刺激可以促进周围神经损伤修复,具体的机制尚未完全明确。目的:探讨电刺激诱导miR-741-3p调控Radil对施万细胞迁移的影响。方法:①12只雄性SD大鼠,随机分为电刺激组和对照组,电刺激组在坐骨神... 详细信息

背景:越来越多的动物实验和临床研究证实电刺激可以促进周围神经损伤修复,具体的机制尚未完全明确。目的:探讨电刺激诱导miR-741-3p调控Radil对施万细胞迁移的影响。方法:①12只雄性SD大鼠,随机分为电刺激组和对照组,电刺激组在坐骨神经挤压伤后连续电刺激7 d,对照组在坐骨神经挤压后不做任何处理。术后第7天取损伤处神经,利用荧光原位杂交技术检测两组miR-741-3p的表达差异。②通过miRDB、TargetScan和miRWalk数据库预测miR-741-3p靶基因。③将miR-741-3p模拟物及其对照、miR-741-3p抑制物及其对照、Radil siRNA及其对照、miR-741-3p抑制物+Radil siRNA及miR-741-3p抑制物+siRNA对照对施万细胞进行转染,采用RT-PCR检测转染效率,Transwell小室检测施万细胞的迁移能力。结果与结论:①电刺激组神经残端miR-741-3p荧光强度低于对照组;②数据库预测结果显示有69个基因可能是miR-741-3p靶基因,Radil是预测靶基因之一,主要参与细胞黏附和迁移;③与miR-741-3p抑制物对照组相比,miR-741-3p抑制物组施万细胞迁移数增多(P<0.05);与miR-741-3p模拟物对照组相比,miR-741-3p模拟物组施万细胞迁移数减少(P<0.05);与siRNA对照组相比,Radil siRNA组施万细胞迁移数减少(P<0.05);④与miR-741-3p抑制物对照组相比,miR-741-3p抑制物组Radil的表达水平升高;与miR-741-3p模拟物对照组相比,miR-741-3p模拟物组Radil的表达水平降低;⑤与miR-741-3p抑制物+siRNA对照组相比,miR-741-3p抑制物+Radil siRNA组施万细胞迁移数减少(P<0.05)。结果表明,电刺激通过下调miR-741-3p调控Radi的表达来促进施万细胞迁移。

关键词：施万细胞电刺激 miR-741-3p Radil 细胞迁移神经再生

Structure and intrinsic magnetic properties of Sm_(1-x)Pr_xCo_5(x=0–0.6) compounds

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Rare Metals 2016年第8期35卷 627-631页

作者： Miao-Ling xu Ming yue yu-qing Li Qiong Wu yun Gao College of Materials Science and Engineering Beijing University of TechnologyBeijing 100124China Samsung Advanced Institute of Technology Beijing 100028China

In this work, the effects of Pr content on the structure and intrinsic magnetic properties of Sml-xPrxCO5 （x = 0-0.6） compounds prepared by induction melting were systematically investigated by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, and magnetic measurements. Microstructural observation and chemical composition analysis show that Sml xPrxCos compounds are composed of （Sin, Pr）Co （1：5） phase and （Sm, Pr）-rich grain boundary phase. XRD results show that all the Sml-xPrxCO5 compounds have a （Sm, Pr）lCo main phase with the hexagonal CaCus-type crystal structure and the （Sm, Pr）2 Co7 impurity phase. In addition, the detailed research shows that the lattice constants （a, c） and unit volume （V） are all enlarged with the increases in Pr con- tent. According to the magnetic measurements, as the Pr content increases to larger than 0.4, both the Curie tem- perature （Tc） and the anisotropy field （HA） of all the Pr- doped compounds decrease rapidly. Meanwhile, the mag- netization of Sml_***5 compounds at applied field of 14 T （MI4 T） are observably improved with Pr doping content of x 〉 0.3. Among them, Smo.6Pro.4Co5 compound exhibits slightly lower HA and Tc, but much higher M14 T than those of the binary SmCos, indicating that doping of proper Pr content into SmCo5 compound can optimize the intrinsic magnetic properties. As a result, the optimal intrinsic magnetic properties of HA = 29.11 T,Tc = 989 K, and M14 T = 102.31 mA.m2.g-1 are obtained in Smo.6Pro.4C05 compound.

关键词： Sml-xPrxCo5 compounds Microstructure Crystal structure Intrinsic magnetic property

AN EFFICIENT RED BLOOD CELL MODEL IN THE FRAME OF IB-LBM AND ITS APPLICATION

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International Journal of Biomathematics 2013年第1期6卷 1-22页

作者： yuAN-qing xu FANG-BAO TIAN yu-LIN DENG School of Life Science Beijing Institute of Technology Beijing 100081 P. R. China Department of Mechanical Engineering Vanderbilt University2301 Vanderbilt Place Nashville Tennessee 37235-1592 USA

A two-dinmnsional red blood cell （RBC） membrane model based on elastic and Euler- Bernoulli beam theories is introduced in the frame of immersed boundary-lattice Boltz- mann method （IB-LBM）. The effect of the flexible membrane is handled by the immersed boundary method in which the stress exerted by the RBC on the ambient fluid is spread onto the collocated grid points near the boundary. The fluid dynamics is obtained by solving the discrete lattice Boltzmann equation. A ＂ghost shape＂, to which the RBC returns when restoring, is introduced by prescribing a bending force along the bound- ary. Numerical examples involving tumbling, tank-treading and RBC aggregation in shear flow and deformation and restoration in poiseuille flow are presented to verify the method and illustrate its efficiency. As an application of the present method, a ten-RBC colony being compressed through a stenotic microvessel is studied focusing the cell-cell interaction strength. Quantitative comparisons of the pressure and velocity on speci- fled microvessel interfaces are made between each aggregation case. It reveals that the stronger aggregation may lead to more resistance against blood flow and result in higher pressure difference at the stenosis.

关键词： IB-LBM Euler Bernoulli beam microvessel RBC aggregation stenosis.

Dense copper azide synthesized by in-situ reaction of assembled nanoporous copper microspheres and its initiation performance

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Defence Technology（防务技术） 2022年第6期18卷 1065-1072页

作者： Xing-yu Wu Ming-yu Li qing-xuan Zeng qing-xia yu State Key Laboratory of Explosion and Technology Beijing Institute of TechnologyBeijing100081PR China

Copper azide with high density was successfully synthesized by in-situ reaction of nanoporous copper(NPC)precursor with HN_(3) *** with pore size of about 529 nm has been prepared by electroless plating using polystyrene(PS)as *** copper shells thickness of NPC was controlled by adjusting the PS loading *** effects of copper shell on the morphology,structure and density of copper azide were *** conversion increased from 87.12%to 95.31%when copper shell thickness decrease from 100 to 50 ***,the density of copper azide prepared by 529 nm NPC for 24 h was up to 2.38 g/cm^(3).The hollow structure of this NPC was filled by swelling of copper azide which guaranteed enough filling volume for keeping the same shape as well as improving the charge ***,HNS-IV explosive was successfully initiated by copper azide with minimum charge thickness of 0.55 mm,showing that copper azide prepared has excellent initiation performance,which has more advantages in the application of miniaturized explosive systems.

关键词： Nanoporous copper Electroless plating In-situ reaction Copper azide

Gram-scale preparation of dialkylideneacetones through Ca(OH)_2-catalyzed Claisen-Schmidt condensation in dilute aqueous EtOH

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Chinese Chemical Letters 2019年第1期30卷 263-265页

作者： Hao Zhang Mengting Han Chenggen Yang Lei yu qing xu Guangling College Yangzhou University School of Chemistry and Chemical Engineering Yangzhou University

A synthetic method of dialkylideneacetones has been developed. Compared with known protocols, the method employed catalytic Ca(OH)_2 as the cheap, mild base catalyst and dilute aqueous EtOH(20%, v/v)as the green and safe solvent. The procedure was easily operated: In most cases, the product could be isolated by a simple filtration, and purified by washing with water. This paper provided experimental details of the reactions, which could be applied in gram-scale synthesis and should be a very reliable and practical protocol to prepare these useful compounds in laboratory and at the industrial level.

关键词： Claisen-Schmidt condensation Acetone Aldehyde α,β-Unsaturated ketone Dialkylideneacetone

Numerical simulation of hydraulic fracture propagation in tight oil reservoirs by volumetric fracturing

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Petroleum Science 2015年第4期12卷 674-682页

作者： Shi-Cheng Zhang Xin Lei yu-Shi Zhou Guo-qing xu College of Petroleum Engineering University of Petroleum

Volumetric fracturing is a primary stimulation technology for economical and effective exploitation of tight oil reservoirs. The main mechanism is to connect natural fractures to generate a fracture network system which can enhance the stimulated reservoir volume. By using the combined finite and discrete element method, a model was built to describe hydraulic fracture propagation in tight oil reservoirs. Considering the effect of horizontal stress difference, number and spacing of perforation clus- ters, injection rate, and the density of natural fractures on fracture propagation, we used this model to simulate the fracture propagation in a tight formation of a certain oil- field. Simulation results show that when the horizontal stress difference is lower than 5 MPa, it is beneficial to form a complex fracture network system. If the horizontal stress difference is higher than 6 MPa, it is easy to form a planar fracture system; with high horizontal stress differ- ence, increasing the number of perforation clusters is beneficial to open and connect more natural fractures, and to improve the complexity of fracture network and the stimulated reservoir volume （SRV）. As the injection rate increases, the effect of volumetric fracturing may be improved; the density of natural fractures may only have a great influence on the effect of volume stimulation in a low horizontal stress difference.

关键词： Tight oil reservoir Volumetric fracturingFracture propagation Horizontal stress difference Stimulated reservoir volume

A Flow Stress Model for High Strength Steels with Low Carbon Bainite Structure

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Journal of Iron and Steel Research International 2016年第4期23卷 372-379页

作者： Bao-sheng XIE qing-wu CAI Wei yu Shi-xin xu Ban WANG Collaborative Innovation Center of Steel Technology University of Science and Technology Beijing National Engineering Research Center of Advanced Rolling University of Science and Technology Beijing

Two kinds of steels （YP960 and YP690） with low carbon bainite structure were designed, and their flow stress and strain hardening exponents were studied. The results showed that, when Hollomon relation was applied to descrihe the flow stress, there were significanl errors between the experimental and calculated points in specimens tempered below 400 ℃, while a high precision was ohserved in samples tempered above 400℃. Whereas, the modijied Voce relation could effectively predici the flow stress as well as the strain hardening exponent at different tempe ring temperatures, which was verified by unbiased estimators such as maximum relative error （MRXE） and average ahsolute relative error （AARE）. Besides, the modified Voee relation was also applied to estimate the maximum uniform strain, and the correlation coefficients （R） between the experimental data and calculated maximum uniform strain were more than 0.91. The high correlation coefficients indicated that the modified Vote relation could effec lively predict the uniform deformation ability of high strength steels with low carbon bainite structure at different tempering temperatures.

关键词： tempering temperature flow stress low carbon bainite Voce type relation strain hardening exponent