检索结果-南通市图书馆

Synthesis of novel quaternary ammonium surfactants containing adamantane

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2012年第6期23卷 653-656页

作者： Jian Wei Guo Xing zhong hua Zhu li Juan Feng Ying De Cui Faculty of Chemical Engineering ＆ light Industry Guangdong University of Technology Guangzhou 510006 China

A series of novel quaternary ammonium surfactants containing adamantane were designed and synthesized from 1-adamanta- necarboxylic acid. The structures of target surfactants were confirmed by 1H NMR, elements analysis and FFIR. Surface properties of these surfactants were investigated. Due to the lipophilicity of adamantane, the critical micelle concentration （CMC） and C2o values of the synthesized quaternary ammonium surfactants are lower than that of conventional quaternary ammonium surfactants.

关键词： Adamantane Synthesis Quaternary ammonium surfactants 1-(Alkyldimethylammoniamethyl) adamantane bromide

Synthesis and Characterization of Novel Layered lithium Sodium Silicate (Silinaite) and the Mesoporous Materials from Silinaite

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2006年第4期17卷 525-528页

作者： Chun Hui ZHOU Hong Qiang GUO Hui Jun CAO Xiao Nian li zhong hua GE Jie li College of Chemical Engineering and Materials Science Zhejiang University of Technology Hangzhou 310032

Novel layered silinaite has been synthesized using an aqueous mixture of water glass, liOH and NaOH under hydrothermal crystallization. Subsequently transformation of silinaite into mesoporous materials （SDM） was achieved at mild condition using cetyltfimethylammonium bromide as structure-directing agents. The resulting samples were characterized by XRD, SEM, FTIR nitrogen adsorption-desorption isotherms and catalytic performance in bulky molecular involved reaction. The results revealed that synthesized mesoporous materials derived from the silinaite exhibited an ordered hexagonal crystal structure with average pore diameter 2.7 nm and BET surface area 817m^2/g. The SDM-supported ZnCl2 catalyst, prepared by impregnationevaporation method, retained the mesoporous structure and showed high selectivity in alkylation of benzene with benzyl chloride.

关键词： Silinaite mesoporous materials layered solid catalysts characterization.

Metallurgy of aluminum-inspired formation of aluminosilicate-coated nanosilicon for lithium-ion battery anode

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2022年第6期41卷 1880-1888页

作者： Yu Zhou Peng-Hu Niu zhong-hua li Pan-Pan Zhang Ming-Ru Su Ai-Chun Dou Xiao-Wei li Yun-Jian liu School of Material Science and Engineering.Jiangsu University Zhenjiang 212013China

Modification of Si anode with various coating matrixes is a promising strategy to resolve the unsta-ble solid electrolyte interphase ***,the com-plex preparation process and inherently weak interaction between Si and other matrixes impede its practical *** by the metallurgical process of aluminum,an aluminosilicate matrix was prepared as coating layer on the surface of Si nanoparticles after heat *** nanoparticles with a uniform native oxide layer were used as seed crystals for the adsorption of aluminum *** strong symbiosis and bond between alumina and silica,such as mullite(3Al_(2)O_(3)·2SiO_(2))or kaolin(Al2O_(3)·SiO_(2)·2H_(2)O),provide homogeneous and durable contact coating *** as-produced Si/SiO_(2)·Al_(2)O_(3)composite delivers a charge capacity of 1440 mAh·g^(-1)at 100 mA·g^(-1)and remains 879 mAh·g^(-1)at 3 A·g^(-1).After 200 cycles,the capacity retention remains high at 76%.The enhanced properties were ascribed to SiO_(2)·Al_(2)O_(3)syner-gistic composite coating layer,which could hinder the interfacial side chemical reaction and buffer volume change of Si.

关键词： lithium-ion batteries Silicon anode Alumina coating Interface stability

Cooperative enhancement of mechanical and tribological properties through tailoring TiN transition interface in boron nitride nanosheets reinforced copper composites

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第10期43卷 5202-5215页

作者： zhong-hua li liang liu Xin You Jian-Hong Yi Rui Bao Ming-Yi Zhu Song Lu Jun-Jun Pai Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China Key Laboratory of Advanced Materials of Yunnan Province Kunming University of Science and TechnologyKunming 650093China

Strengthening interface bonding between boron nitride nanosheets(BNNS)and copper matrix is an essential prerequisite for exploiting a new generation of copper matrix composites(CMCs)with high strength and wear ***,BNNS/Cu composites were fabricated by the powder metallurgy route,matrix-alloying(adding 1.0 wt%Ti)strategy was adopted to improve the interfacial wettability and strengthen interface adhesion.A typical"sandwich"-like multiply interface structure involving TiN transition layers,BNNS and Cu matrix had been well constructed through the rational heat treatment(900℃ for 120 min).Additionally,nano-sized TiB whisker was in situ formed in the vicinity of the interface,it had linked the BNNS-Cu-TiN multiply interface,which played a role of"threading the needle"and significantly strengthened the multi-interfaces *** specific interface structure was finely characterized,and the formation mechanism of solid-state interfacial reaction feature was *** results demonstrated that the ultimate tensile strength(UTS)of BNNS/Cu-(Ti)-900℃ increased from 248 to 530 MPa(increased by 114%),and the coefficient of friction(COF)decreased from 0.51 to 0.28 than pure *** work highlights the importance of interface configuration design,which contributes to the development of CMCs with prominent comprehensive properties.

关键词： Copper matrix composites Boron nitride nanosheets Interface structure Mechanical and frictional properties

DSMC modeling of rarefied ionization reactions and applications to hypervelocity spacecraft reentry flows

在线全文

学校读者我要写书评

暂无评论

Advances in Aerodynamics 2020年第1期2卷 120-144页

作者： Ming Fang Zhi-Hui li zhong-hua li Jie liang Yong-Hao Zhang Hypervelocity Aerodynamics Institute China Aerodynamics Research and Development CenterP.O.Box 211Mianyang 621000China National Laboratory for Computational Fluid Dynamics BUAANo.37 Xueyuan RoadBeijing 100191China James Weir Fluids Laboratory Department of Mechanical&Aerospace EngineeringUniversity of StrathclydeGlasgow G11XJUK

The DSMC modeling is developed to simulate three-dimensional(3D)rarefied ionization flows and numerically forecast the communication blackout around spacecraft during hypervelocity reentry.A new weighting factor scheme for rare species is introduced,whose key point is to modify the corresponding chemical reaction coefficients involving electrons,meanwhile reproduce the rare species in resultants and preserve/delete common species in reactants according to the weighting *** resulting DSMC method is highly efficient in simulating weakly inhomogeneous flows including the Couette shear flow and controlling statistical fluctuation with high *** accurate reliability of the present DSMC modeling is also validated by the comparison with a series of experimental measurements of the Shenzhou reentry capsule tested in a low-density wind tunnel from the HAI of *** obtained electron number density distribution for the RAM-C II vehicle agrees well with the flight experiment data,while the electron density contours for the Stardust hypervelocity reentry match the reference data *** addition,the present 3D DSMC algorithm can capture distribution of the electron,N+and O+number densities better than the axis-symmetric DSMC *** introduction of rare species weighting factor scheme can significantly improve the smoothness of the number density contours of rare species,especially for that of electron in weak ionization case,while it has negligible effect on the macroscopic flow *** ionization characteristics of the Chinese lunar capsule reentry process are numerically analyzed and forecasted in the rarefied transitional flow regime at the flying altitudes between 80 and 97 km,and the simulations predict communication blackout altitudes which are in good agreement with the actual reentry flight *** the spacecraft reentry with hypervelocity larger than the second cosmic speed,it is forecasted and verified by the present DSMC modeling

关键词： Spacecraft hypervelocity reentry Chemical reaction Air ionization effect Rarefied gas dynamics DSMC method Communication blackout

Experimental study on the variation law of coal temperature during excavation in coal mines

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Coal Science & Engineering(China) 2013年第2期19卷 133-135页

作者： Yi-Shan PAN lian-Man XU zhong-hua li Guo-Zhen li School of Mechanics and Engineering Liaoning Technical University Fuxin 123000 China

By testing the temperature of the coal and the stress of the working surface, we got the variation law of coal temperature and coal stress during the excavation. The result shows that the activities of mining affect the coal temperature, the fluctuation of coal temperature and the coal stress is synchronous. During the smooth change of crustal stress, the coal temperature basically keeps unchanged, when the dynamic phenomenon appears, the coal temperature changes, as well the coal stress. Therefore, we can use the online coal temperature monitoring system to test the coal temperature of the working surface continuously, and it can provide basic information for forecasting coal mine power disaster before it happens.

关键词： coal temperature coal stress coal fracturing gas desorption

Differentially expressed genes identified by microarray analysis Following leptin treatment of hepatic stellate cells

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Medical Journal 2010年第6期123卷 726-729页

作者： zhong li-hua CHENG Jun ZHU li-ying Department of Infectious Diseases Forth Affiliated Hospital of Harbin Medical UniversityHarbinHeilongjiang 150001China Institute of Infectious Diseases Beijing Ditan HospitalBeijing 100011China

Background liver fibrosis is the process through which numerous chronic liver diseases develop into liver cirrhosis. Leptin can activate hepatic stellate cells （HSCs） and play an important role in the formation of liver fibrosis. However, the process by which leptin activates HSCs is complicated, and research on this process is limited. The aim of this study was to explore the related changes in gene expression and the control mechanisms involved in leptin activated HSCs to understand the overall mechanism of liver fibrosis development. Methods We cultivate rat HSCs, with and without stimulation by leptin, and extracted mRNA. Differentially expressed genes were detected by microarray analysis. Results The differentially expressed genes identified included six upregulated genes and six downregulated genes. The representative upregulated genes included short chain dehydrogenase （CY5/CY3=2.265） and pulmonary surfactant protein A1 （CY5/CY3=2.036）. The significant downregulated gene encoded hepatic stearoyl coenzyme A desaturase 1 （SCD-1）（CY5/CY3=0.351）.Conclusion Leptin might mediate the molecular biological mechanisms of liver fibrosis.

关键词： leptin hepatic stellate cells microarray analysis

Local magnetic moment oscillation around an Anderson impurity on graphene

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 192-201页

作者： Shuai li Zhen Ma Jin-hua Gao School of Science Hebei University of Science and Technology School of Electronics and Information Zhengzhou University of Light Industry School of Physics and Wuhan National High Magnetic Field Center Huazhong University of Science and Technology

We theoretically investigate the spin resolved Friedel oscillation （FO） and quasiparticle interference （QPI） in graphene induced by an Anderson *** the impurity becomes magnetic,the resulted FO becomes spin dependent,which gives rise to a local magnetic moment oscillation with an envelop decaying as r-2in real space in the doping ***,at half filling,the electron density and local magnetic moment will not oscillate but decay as *** spin resolved FO has both sublattice and spin ***,the local magnetic moment decay at half filling only occurs at one sublattice of graphene,which is quite like the phenomenon observed in the STM experiment (***ález-Herrero et al.,Science 352,437 （2016）).We further give an analytic formula about such spin dependent FO based on the stationary phase ***,we study the interference of quasiparticles around the magnetic impurity by calculating the spin dependent Fourier-transformed local density of states （FT-LDOS）.Our work gives a comprehensive understanding about the local magnetic moment oscillation around an Anderson impurity on graphene.

关键词： Friedel oscillation local magnetic moment graphene Anderson impurity

脉冲Leslie-Gower型捕食者-食饵系统的概周期解

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

东北师大学报（自然科学版） 2016年第3期48卷 48-53页

作者：钟丽华北华大学数学与统计学院吉林吉林132013

考虑了食饵具避难效应的脉冲Leslie-Gower型生物系统.利用相应的常微分方程系统解和脉肿系统解的关系,得到脉冲生物系统的持久性及唯一概周期解的存在性.

关键词：脉冲系统 Leslie-Gower型捕食者-食饵模型概周期解持久性