检索结果-南通市图书馆

Characteristic atom arranging crystallogphy of alloy phases for Au-Cu system

Science china(Technological Sciences) 2011年第6期54卷 1560-1567页

作者： XIE YouQing1,2,3.LIU XinBi1,2,3.PENG HongJian4,NIE YaoZhuang5,LI XiaoBo6 & LI YanFen1,2,3.1 School of Materials Science and engineering,Central South university,changsha 410083.{3. 2 Powder Metallurgy Research Institute,Central South university,changsha 410083.{3. 3.State Key Laboratory of Powder Metallurgy,Central South university,changsha 410083.{3. 4 School of chemistry and chemical engineering,Central South university,changsha 410083.{3. 5 School of Physical Science and Technique,Central South university,changsha,410083.{3. 6 college of Mechanical engineering,Xiangtan university,Xiangtan 411105,{3. School of Materials Science and engineering Central South University Changsha China Powder Metallurgy Research Institute Central South University Changsha China State Key Laboratory of Powder Metallurgy Central South University Changsha China School of chemistry and chemical engineering Central South University Changsha China School of Physical Science and Technique Central South University Changsha China college of Mechanical engineering Xiangtan University Xiangtan China

In this paper,it is pointed out that the descriptions of alloy phase structures are dependent on structural unit *** the systematic science of alloys(SSA),the alloy phase structures are described by means of the symmetry element sequence combining with characteristic atom *** is named the characteristic atom arranging structure,which can display the characteristic atoms at the lattice sites and the micro-inhomogeneity,besides the *** characteristic atom has its own characters:neighboring configuration,potential energy,volume and electronic *** micro-inhomogeneity of alloy phases can be described by concentrations and short-range ordered parameters of characteristic *** differences between the electronic structures of alloy phases and electronic structures of characteristic atoms in the alloy phases are also discussed.

关键词： systematic science of alloys Au-Cu system alloy phase structure micro-inhomogeneity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Synthesis and Thermal Stability of Antimony Tris (Thioethyl Stearate) for PVC

引用

Journal of Central South university 2000年第3期12卷 146-148页

作者： LIU You nian,WANG Chun jiang,SHU Wan gen,ZENG Dong ming,Chen Qi yuan (college of chemistry and chemical {3.ing, Central South university, changsha 410083. china) college of chemistry and chemical {3.ing Central South University Changsha China

A novel type of thermal stabilizer-antimony tris (thioethyl stearate) (ATS) was synthsized. Its thermal stability was measured by heat-aging oven test when incorporated into PVC. ATS was synthesized from stearic acid, antimony trioxide and 2-mercaptoethanol in two steps. The reaction conditions of synthesis were optimized through orthogonal test. Experimental results show that the molar ratio of stearic acid and antimony tris (2-hydroxyethylthiolate) was 1.2, adding 0.6%tetra-n-butyl titanate as catalyst and xylene as azeotropic solvent, heating and refluxing for about 4 h, and the yield of ATS is 83.9%. The thermal stability time is about 40 min(at 200 °C) when added 2phr(per hundred resin) in PVC. The thermal stability of ATS is better than that of Ca-Zn complex and basic lead stabilizers, and equal to that of dibutyltin dilaurate.

关键词： thermal stabilizer antimony thiolate synthesis thermal stability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Analysis of volatile oil in Rhizoma Ligustici Chuanxiong-Radix Paeoniae Rubra by gas chromatography-mass spectrometry and chemometric resolution

引用

Acta Pharmacologica Sinica 2006年第4期27卷 491-498页

作者： Xiao-ru LI Yi-zeng LIANG~2 Fang-qiu GUO college of chemistry and chemical {3.ing,Research Center of Modernization of Traditional Chinese Medicines,Central South university,changsha 410083.china college of chemistry and chemical {3.ing Research Center of Modernization of Traditional Chinese Medicines Central South University Changsha China

Aim:To analyze the volatile chemical components of the herbal pair RhizomaLigustici Chuanxiong-Radix Paeoniae Rubra(RLC-RPR)and compare them withthose of each of the herbs ***:Gas chromatography-mass spectrom-etry(GC-MS),a chemometric resolution technique using the heuristic evolvinglatent projections(HELP)method,and the overall volume integration methodwere ***:In total,52,3.,and 61 volatile chemical components in RLC,RPR,and RLC-RPR essential oils were determined,respectively,accounting for95.14%,95.19%,and 89.68% of the total contents of essential oil of RLC,RPR,andRLC-RPR,*** main volatile chemical components werebutyldienephthalide(20.65%)and ligustilide(50.15%)for RLC;and n-hexadecanoicacid(20.18%),[Z,Z]9,12-octadecadienoic acid(3..11%),2-hydroxy-benzaldehyde(17.08%)for RPR,and butyldienephthalide(14.80%),and ligustilide(3..91%)*** main volatile chemical components of RLC-RPR were almost thesame as those of RLC,but the relative amounts were ***:Thenumber of volatile chemical components in RLC-RPR was almost equal to the sumof the number in the 2 constituent herbs,but the relative amounts were ***,an acid-base reaction takes place during the process of decoctingthe *** data gathered in this study may be helpful for understanding thesynergistic nature of this herb pair in traditional Chinese medicine.

关键词： herbal pair Rhizoma Ligustici Chuanxiong-Radix Paeoniae Rubra essential oil gas chromatography-mass spectrometry chemometric resolution method

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Oscillation Conditions for An Electrode-separated Piezoelectric Sensor in Electrolyte Solution

引用

chemical Research in Chinese Universities 1996年第1期12卷 22-31页

作者： SHEN Da-zhong(chemistry college, Shandong university, Jinan, 250100)KANG Qi({3. engineering Department, Jinan Branch of Shandong Institute of Mining and Technology, Jinan, 25003. )YAO Shou-zhuo(New Material Institute, hunan university, changsha, 4100 SHANDONG UNIV COLL CHEMJINAN 250100PEOPLES R CHINA INST MIN & TECHNOL DEPT CHEM ENGNJINAN 250031PEOPLES R CHINA hunan UNIV NEW MAT INSTCHANGSHA 410082PEOPLES R CHINA

Based on the needs of the oscillation equation and frequency stability, three oscillation conditions are proposed and have been experimentally verified for an electrode-separated piezoelectric sensor (ESPS ) in electrolyte solutions. The present paper covers the dependence of the minimum cell constant needed for the ESPS on solution conductivity. The oscillation conditions of the classical liquid piezoelectric sensor are discussed. The 'cease-to-oscillate' frequencies of the ESPS were measured.

关键词： Piezoelectric sensor Quartz crystal Cell constant Conductivity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Separation of cobalt and nickel by non-equilibrium solvent extraction

引用

Journal of Central South university of Technology 2001年第1期8卷 50-53页

作者： WANG Kai yi, NIU Cong wei, QIAN Dong, LIU Ju hong, CHEN Xiao yi, LAI De yong (college of chemistry and chemical {3.ing, Central South university, changsha 410083. china) college of chemistry and chemical {3.ing Central South University Changsha China

The separation of cobalt and nickel in the ammoniacal sulfate solution by non equilibrium solvent extraction with a phosphate (P3.3. as extractant was studied. In the experiment, the effects of equilibrium pH value in aqueous phase, contact time of the two phases, the air blowing time for feed liquor in the open beaker on percentage extraction of cobalt and nickel and percentage reextraction of nickel from the loaded organic phase with dilute H 2SO 4. etc were studied. The results showed that: Co(Ⅱ) can be oxidized to Co(Ⅲ) ammino complex by adding (NH 4) 2S 2O 8 or blowing air to the aqueous phase, and Co(Ⅲ) ammino complex is a kind of kinetically inert complex. Its extractive speed is very slow, while the nickel′s is much faster than that of cobalt. By controlling the contact time of the two phases, nickel can be separated from cobalt by non equilibrium solvent extraction. Then nickel was reextracted from the loaded organic phase with dilute H 2SO 4.

关键词： non equilibrium solvent extraction separation cobalt nickel

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A new method to improve surface morphology of Ni-Fe-Mo-Co alloy electrode and its catalytic activity for HER

引用

Rare Metals 2007年第3期26卷 205-212页

作者： LUO Beiping REN Buye XU You ZHENG Yajie Department of chemistry and chemical engineering Hunan Institute of Science and Technology Yueyang 414000 China college of Metallurgical Science and engineering Central South University Changsha 410083 China Research Institute of Materials Science South China University of Technology Guangzhou 510640 China

A new pretreatment method has been developed to improve the catalytic activity of the Ni-Fe-Mo-Co alloy electrode for hydrogen evolution reaction （HER）. The procedure involves pre-electrolyzing the Ni-Fe-Mo-Co alloy electrode in 3.% KOH solution containing 10% potassium sodium tartrate at 70℃ for 2 h, until some of the Mo and Fe elements are leached out. The surface morphology of the Ni-Fe-Mo-Co alloy demonstrates a unique hive-like structure after the pre- treatment, which has the pore size in a nanometer range （about 50 nm）, a very large real surface area, and good stability. The results of the electrochemical studies show that compared to other similar electrode materials and the treated Ni-Fe-Mo-Co electrode by leaching method, the pre-treated Ni-Fe-Mo-Co electrode has a much lower overpotential and much higher exchange current density for HER. In addition, a long-term continuous electrolysis test with a current interruption shows that the Ni-Fe-Mo-Co alloy has excellent catalytic stability.

关键词： catalytic activity surface treatment Ni-Fe-Mo-Co alloy hydrogen evolution electrodeposition

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

溶胶-凝胶工艺合成Ti(C,N)超细粉末

引用

无机材料学报 1998年第5期13卷 739-744页

作者：向军辉肖汉宁湖南大学化学化工学院长沙410082

以TiO（OH）2溶胶和炭黑为主原料，采用溶胶-凝胶工艺。经N2气氛下碳热还原合成了Ti（C，N）超细粉末．分析了合成过程的热力学，探讨了原料配比、合成温度、保温时间和氮气流量等工艺参数对Ti（C,N）组成和性能的影响．通过控制工艺条... 详细信息

以TiO（OH）2溶胶和炭黑为主原料，采用溶胶-凝胶工艺。经N2气氛下碳热还原合成了Ti（C，N）超细粉末．分析了合成过程的热力学，探讨了原料配比、合成温度、保温时间和氮气流量等工艺参数对Ti（C,N）组成和性能的影响．通过控制工艺条件，可以得到x值为0．2～0．7，粒径＜100nm的Ti（C1-x，Nx）超细粉末.

关键词：溶胶凝胶碳氮化钛超细粉末粉末冶金

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Ribozyme probe based on molecular beacon for real time monitoring of enzymatic cleavage process

引用

Chinese Science Bulletin 2003年第23期48卷 2581-2584页

作者： MENG Xiangxian, WANG Kemin, TAN Weihong, LI Jun, TANG Zhiwen, GUO Qiuping, HUANG Shasheng & LI Du State Key Laboratory of Chemo/Biosensing and Chemometrics, Institute of Biological Technology, college of chemistry and chemical Engi-neering,{3., changsha 410082, china Correspondence should be addressed to Wang Kemin (e-mail: kmwang @***) State Key Laboratory of Chemo/Biosensing and Chemometrics Institute of Biological Technology College of Chemistry and Chemical Engineering Hunan University Changsha China

Ribozyme probe based on molecular beacon (MBR) for monitoring enzymatic cleavage process in real time is designed and studied. The approach relies on ri-bozyme substrates modified at the two arms, with a fluores-cent moiety attached to the end of one arm and a non-fluorescent quenching moiety attached to the end of the other arm. MBR is employed to directly convert the cleavage information into fluorescence signal in real time. Compared with traditional approach, this method provides a no-radiolabeling, sensitive and effective way to research on the ribozyme activity, enzymatic dynamic process and ri-bozyme function during gene therapy. The activity of the ribozyme against hepatitis C virus RNA (HCV-RNA) is stud-ied based on this assay.

关键词：酶探测器分裂过程动力学酶活性基因治疗肝炎

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Study on Syntheses and Characterizations of Polymethylphenethylsilane, Polymethylcyclohexylsilane and their Copolymers

引用

Journal of Central South university 2000年第2期12卷 92-96页

作者： HU Hui ping 1,HUANG Ke long 1,PAN Chun yue 1,CHEN De ben 2 (1 college of chemistry and chemical {3.ing, Central South university of Technology, changsha 410083. china 2 Department of chemistry, Sichuan university, Chengdu 610064, china college of chemistry and chemical {3.ing Central South University of Technology Changsha China Department of chemistry Sichuan University Chengdu China

The effects of adding cosolvents of diglyme and 15-crown-5 to the reaction mixture of Wurtz-type coupling of dichlorosilanes on the yield and relative molecular mass dispersity of polymethylphenethylsilane(PMPES) were discussed. The results show that addition of 10%(volume ratio of diglyme to toluene) diglyme as a cosolvent to the reaction mixture leads to the yield increase of PMPES with a monomodal distribution of relative molecular masses. Adding 10%diglyme to the reaction mixtures, the yields of polymethylcyclohexylsilane(PMCS) and copolymers (polymethylphenethylsilane-co-methylcyclohexylsilane), (the molar ratios of methylphenethyldichlorosilane to methylcyclohexyldichlorosilane were 2.0, 1.0 and 0.5, and the copolymers were abbreviated by Copolymers I, II, III, respectively) are 47%, 52%, 54%, 53., respectively. Their relative molecular masses ([`(M)]w )(\bar M_w ) almost reach 105. These polysilanes were characterized by 1H-NMR, IR and UV absorption spectrum.

关键词： polysilane cosolvent synthesis characterization

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Influences of Ti substitution on the structure and electrochemical properties of Mg_(1-x)Ti_xNi(x=0,0.1, 0.2, and 0.3. hydrogen storage alloys

引用

Rare Metals 2009年第5期28卷 504-510页

作者： HUANG Hongxia HUANG Kelong LIU Suqin CHEN Dongyang college of chemistry and chemical {3.ing Central South University Changsha 410083 China Department of Materials and chemical engineering Guilin University of Technology Guilin 541004 China

MgNi-based hydrogen storage alloys Mg1–xTixNi （x = 0, 0.1, 0.2, and 0.3. were prepared by means of mechanical alloying. Mg in the alloy was partially substituted by Ti to improve the cycle stability of the alloys. The effects of the substitution of Ti for Mg on the microstructure and electrochemical performances of the alloys were investigated in detail. The results indicate that the substitution of Ti for Mg obviously decreases the discharge capacity, but it significantly improves their cycle stabilities. The microstructure of the alloys analyzed by X-ray diffraction （XRD） and scanning electron microscopy （SEM） shows that the alloys have a dominatingly amorphous structure. The substitution of Ti for Mg helps to improve the anti-oxidation/corrosion ability of the MgNi alloy but demolishes the electrochemical kinetics of hydrogenation/dehydrogenation. The Mg0.9Ti0.1Ni alloy electrode milled for 80 h exhibits the best integrative capability, which has the maximal discharge capacity of 3.1.66 mAh/g and the C3./Cmax of 63.65%.

关键词： hydrogen storage alloys Ti substitution structural characteristic electrochemical properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：