检索结果-南通市图书馆

Adsorption of surfactants onto acrylic ester resins with different pore size distribution

Science china Chemistry 2006年第5期49卷 445-453页

作者： YANG Weiben1,2,3.LI Aimin1,3.CAI Jianguo1,3.MENG Guanhua1,3.& ZHANG Quanxing1,3.1. State Key Laboratory of Pollution Control and Resource Reuse,school of the environment,Nanjing University,Nanjing 210093.china 2. Nanjing College of {3. technology,Nanjing 210048,china 3. Jiangsu engineering & technology Research Center for Organic Toxicant Control and Resource Reuse,Nanjing 21003.,china 1. State Key Laboratory of Pollution Control and Resource Reuse School of the Environment Nanjing University Nanjing 210093 China 2. Nanjing College of chemical technology Nanjing 210048 China 3. Jiangsu engineering & technology Research Center for Organic Toxicant Control and Resource Reuse Nanjing 210038 China

In this study, a series of acrylic ester resins with different pore size distribution were prepared successfully by varying the type and the amount of pore-forming agents. In order to inves-tigate the adsorption behavior and mechanism of surfactants on acrylic ester resins, three kinds of surfactants were utilized as adsorbates that were sodium 6-dodecyl benzenesulfonate (6-NaDBS), sodium 1-dodecyl benzene sulfonate (1-NaDBS) and sodium 1-dodecyl sulfonate, respectively. It was observed that the surface area was available in a particular pore size and an appropriate pore size of resins appeared to be more important for the adsorption of surfactants. As compared to commercial acrylic ester resins XAD-7 and HP2MG, 50# and 3.# resins exhibited more excellent adsorption properties toward 1-NaDBS and 6-NaDBS. The experimental equilibrium data were fitted to the Langmuir, and double-Langmuir models. Two models provided very good fittings for all resins over the temperature range studied. The investigation indicated that electrostatic attraction and hydrogen bond between resins and surfactants were the main forces and had an obvious effect on adsorption proc-ess.

关键词： acrylic ester resin, surfactant, adsorption, pore size distribution, isotherm.

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

An efficient chiral synthesis of (R)-N-[3.acetyl-4-(2-hydroxy-3.isopropylamino-propoxy)phenyl]-butanamide with high enantioselectivity

引用

Science china Chemistry 2009年第8期52卷 1216-1219页

作者： WANG NaiXing1,2 & TANG XinLiang1,3.1 Technical institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100080,china 2 College of Chemistry and chemical {3.,Graduate University of Chinese Academy of Sciences,Beijing 100049,china 3.school of chemical engineering and environment,Beijing institute of technology,Beijing 100081,china 1. Technical institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100080 China 2. College of Chemistry and chemical engineering Graduate University of Chinese Academy of Sciences Beijing 100049 China 3. school of chemical engineering and {3. Beijing Institute of Technology Beijing 100081 China

R-Enantiomer of the β-receptor antagonist N-[3.acetyl-4-(2-hydroxy-3.isopropylamino-propoxy)phenyl] butanamide with high enantioselectivity was synthesized from cheap starting materials and enantiopure chiral reagent through an efficient,convenient and practical synthetic *** product was detected by 1H NMR,13. NMR,and MS,and the enatiomeric excess was determined by chiral HPLC analysis using a chiracel AD-H column.

关键词： chiral synthesis enantioselectivity enatiomeric excess chiral HPLC analysis

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

Mining and Integrating Reliable Decision Rules for Imbalanced Cancer Gene Expression Data Sets

引用

Tsinghua Science and technology 2012年第6期17卷 666-673页

作者： Hualong Yu 1 , Jun Ni 2 , Yuanyuan Dan 3., Sen Xu 4 1. school of Computer Science and engineering, Jiangsu University of Science and technology, Zhenjiang 212003. {3. 2. Department of Radiology, Carver College of Medicine, The University of Iowa, Iowa City, IA 52242, USA 3. school of Biology and chemical engineering, Jiangsu University of Science and technology, Zhenjiang 212003. {3. 4. school of Information engineering, Yancheng institute of technology, Yancheng 224051, {3. school of Computer Science and engineering Jiangsu University of Science and Technology Zhenjiang 212003 China|c|

There have been many skewed cancer gene expression datasets in the post-genomic era. Extraction of differential expression genes or construction of decision rules using these skewed datasets by traditional algorithms will seriously underestimate the performance of the minority class, leading to inaccurate diagnosis in clinical trails. This paper presents a skewed gene selection algorithm that introduces a weighted metric into the gene selection procedure. The extracted genes are paired as decision rules to distinguish both classes, with these decision rules then integrated into an ensemble learning framework by majority voting to recognize test examples; thus avoiding tedious data normalization and classifier construction. The mining and integrating of a few reliable decision rules gave higher or at least comparable classification performance than many traditional class imbalance learning algorithms on four benchmark imbalanced cancer gene expression datasets.

关键词： cancer gene expression data class imbalance paired differential expression genes decision ruleensemble learning majority voting

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

Process optimization of reaction of acid leaching residue of asbestos tailing and sodium hydroxide aqueous solution

引用

Science china(Technological Sciences) 2009年第1期52卷 204-209页

作者： DU GaoXiang1,3. ZHENG ShuiLin2 & DING Hao1 1 school of Materials Science and technology, china University of Geosciences (Beijing), Beijing, 100083. china 2 school of chemical and environment engineering, china University of Mining and technology (Beijing), Beijing 100083. china 3.Hebei Qinghe Refractory Group Co. Ltd., Xingtai 054804, china 1. school of Materials Science and technology China University of Geosciences (Beijing) Beijing 100083 China 3. Hebei Qinghe Refractory Group Co. Ltd. Xingtai 054804 China 2. school of chemical and environment {3. China University of Mining and Technology (Beijing) Beijing 100083 China

Silica is the major component of the acid leaching residue of asbestos tailing. The waterglass solution can be prepared by the reaction of the residue with sodium hydroxide aqueous solution. Compared to the high temperature reaction method, this process is environmental friendly and low cost. In this paper, the reaction process of the residue and the sodium hydroxide aqueous solution is optimized. The optimum reaction process parameters are as follows: the usage of sodium hydroxide is 26.4 g/100 g acid leaching residue, the reaction temperature is 90℃, the reaction time is 1 h, and the ratio of the liquid/solid is 2.0. The significance sequence of the process parameters to the alkali leaching reaction effect is the usage of sodium hydroxide > the ratio of the liquid/solid > the reaction time > the reaction temperature. The significance sequence to the leaching ratio of SiO2 is the ratio of the liquid/solid > the usage of sodium hydroxide > the reaction time > the reaction temperature. The significance sequence to the modulus of the sodium silicate is the ratio of the liquid/solid > the usage of sodium hydroxide > the reaction time > the reaction temperature. Under the optimum conditions, the leaching ratio of the SiO2 is 77.5%, and the modulus of the sodium silicate is 3.15. The XRD analysis result indicates that the major components of the alkali leaching residue are serpentine, talc, quartz and some albite.

关键词： asbestos tailing acid leaching residue sodium hydroxide process optimization

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

Morphological Evolution of Nb_2O_5 in a Solvothermal Reaction: From Nb_2O_5 Grains to Nb_2O_5 Nanorods and Hexagonal Nb_2O_5 Nanoplatelets

引用

Journal of Wuhan University of technology(Materials Science) 2009年第2期24卷 245-248页

作者：胡卫兵 school of chemical and environmental {3. Hubei Institute for Nationalities Department of Physics Huazhong University of Science and Technology

Novel Nb2O5 nanorods and polygonal Nb2O5 platelets were generated by a simple solvothermal technique. The geometry evolution of the resultant Nb2O5 from amorphous nanoparticles to crystallized particles, from polygonal platelets to well-elongated nanorods was been studied in detail. The processing parameters, including the reaction temperature, reaction time, concentration of the precursors, and pH value of the solution, which affect the shape and size of the nanorods, were investigated. The Nb2O5 nanorods with different aspect ratios were examined by XRD, SEM and TEM. The experimental results show that Nb2O5 nanorod is the orthorhombic structure and well-crystallized. The growth of the nanorods follows their [001] direction. The successful generation of high quality Nb2O5 nanorods is not only important for transition metal oxide research, but also potentially important for further formation of new Nb-based 1-D nanostructures, such as NbS2 and NbN.

关键词： solvothermal morphological evolution Nb2O5 nanomateraials

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 land surface model incorporated with soil freeze/thaw and its application in GAME/Tibet

引用

Science china Earth Sciences 2006年第12期49卷 1311-1322页

作者： HU Heping1, YE Baisheng2, ZHOU Yuhua3.& TIAN Fuqiang1 1. Department of Hydraulic engineering, Tsinghua University, Beijing 100084, china 2. Cold and Arid Regions environmental and engineering Research institute, Chinese Academy of Sciences, Lanzhou 73.000, china 3. Department of Civil engineering, Massachusetts institute of technology, USA 1. Department of Hydraulic engineering Tsinghua University Beijing 100084 China 2. Cold and Arid Regions environmental and engineering Research institute Chinese Academy of Sciences Lanzhou 730000 China 3. Department of Civil engineering Massachusetts Institute of Technology USA

Land surface process is of great importance in global climate change, moisture and heat exchange in the interface of the earth and atmosphere, human impacts on the environment and eco- system, etc. Soil freeze/thaw plays an important role in cold land surface processes. In this work the diurnal freeze/thaw effects on energy partition in the context of GAME/Tibet are studied. A sophisti- cated land surface model is developed, the particular aspect of which is its physical consideration of soil freeze/thaw and vapor flux. The simultaneous water and heat transfer soil sub-model not only reflects the water flow from unfrozen zone to frozen fringe in freezing/thawing soil, but also demon- strates the change of moisture and temperature field induced by vapor flux from high temperature zone to low temperature zone, which makes the model applicable for various circumstances. The modified Picard numerical method is employed to help with the water balance and convergence of the numerical scheme. Finally, the model is applied to analyze the diurnal energy and water cycle char- acteristics over the Tibetan Plateau using the Game/Tibet datasets observed in May and July of 1998. Heat and energy transfer simulation shows that: (i) There exists a negative feedback mechanism between soil freeze/thaw and soil temperature/ground heat flux; (ii) during freezing period all three heat fluxes do not vary apparently, in spite of the fact that the negative soil temperature is higher than that not considering soil freeze; (iii) during thawing period, ground heat flux increases, and sensible heat flux decreases, but latent heat flux does not change much; and (iv) during freezing period, soil temperature decreases, though ground heat flux increases.

关键词： land surface model,soil freeze/thaw,GAME/Tibet,simultaneous liquid,vapor and heat transfer.

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

One-pot synthesis of crystalline SnO_2 nanoparticles and their low-temperature ethanol sensing characteristics

引用

Science china(Physics,Mechanics & Astronomy) 2009年第10期52卷 1601-1605页

作者： CHEN YuJin1,2,3.ZHU ChunLing4,WANG LiJiao3.& WANG TaiHong2 1 school of Materials Science and engineering,Beijing institute of {3.,Beijing 100081,china 2 Micro-Nano Technologies Research Center,Hunan University,Changsha 410082,china 3.College of Science,Harbin engineering University,Harbin 150001,china 4 College of Material Science and chemical engineering,Harbin engineering University,Harbin 150001,china school of Materials Science and engineering Beijing Institute of Technology Beijing 100081 China Micro-Nano Technologies Research Center Hunan University Changsha 410082 China College of Science Harbin Engineering University Harbin 150001 China College of Material Science and chemical engineering Harbin Engineering University Harbin 150001 China

Crystalline SnO2 nanoparticles(NPs) with a diameter less than 6 nm are synthesized using potassium stannate trihydrate as the precursor in a basic *** synthesized NPs can detect ethanol at a ppm level even at 100℃.Furthermore,the NPs have good selectivity to *** excellent ethanol sensing performances are attributed to the small size effect according to the space-charge model.

关键词： SnO2 nanoparticles sensing characteristics

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

Modification of LiCo_(1/3.Ni_(1/3.Mn_(1/3.O_2 cathode material by CeO_2-coating

引用

Science china(Technological Sciences) 2009年第9期52卷 2737-2741页

作者： WANG Meng,WU Feng,SU YueFeng & CHEN Shi Beijing Key Laboratory of environment,school of chemical {3. and environment,Beijing institute of technology National Development Center of High technology Green Materials,Beijing 100081,china Beijing Key Laboratory of environment School of Chemical Engineering and Environment Beijing Institute of Technology Beijing China National Development Center of High technology Green Materials Beijing 100081 China

LiCo1/3.i1/3.n1/3.2 was coated by a layer of 1.0 wt% CeO2 via sol-gel method. The bared and coated LiMn1/3.o1/3.i1/3.2 was characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM),cyclic voltammogram (CV) and galvanotactic charge-discharge test. The results show that the coating layer has no effect on the crystal structure,only coating on the surface; the 1.0 wt% CeO2-coated LiCo1/3.i1/3.n1/3.2 exhibits better discharge capacity and cycling performance than the bared LiCo1/3.i1/3.n1/3.2. The discharge capacity of 1.0 wt% CeO2-coated cathode is 182.5 mAh.g-1 at a current density of 20 mA.g-1,in contrast to 165.8 mAh.g-1of the bared sample. The discharge capacity retention of 1.0 wt% CeO2-coated sample after 12 cycles reaches 93.2%,in comparison with 86.6% of the bared sample. CV results show that the CeO2 coating could suppress phase transitions and prevent the surface of cathode material from direct contact with the electrolyte,thus enhance the electro-chemical performance of the coated material.

关键词： LiCo1/3.i1/3.n1/3.2 CeO2 coating Lithium-ion battery

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

Determination of the Thermal Expansion Coefficient of Concrete at Early Ages by Using Temperature-stress Testing Machine

引用

Journal of Wuhan University of technology(Materials Science) 2006年第4期21卷 146-149页

作者：霍凯成 Hubei Key Laboratory of Roadway Bridge & Structure engineering Wuhan University of TechnologyWuhan 430070China

By using the uptodate temperatuer-stress testing machine, the thermal expansion coefficient of concrete at early ages was studied and indicative conclusions were achieved ： temperature rising due to hydration heat is not directly correlated with cracking, but the temperature and stress evolation process should be taken into consideration in the same time. Proper chemical admixtures and mineral cornpasitions can improve the mechanical properties of concrete such as thermal expansion coefficient, which is very indicative in practice.

关键词： concrete coefficient of thermal expansion temperature-stress test

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

Thermal Insulation and Strength of Autoclaved Light Concrete

引用

Journal of Wuhan University of technology(Materials Science) 2011年第1期26卷 132-136页

作者：杨若冲吴智深 school of Transportation Southeast University institute of Urban engineering Science & technology Southeast University

The primary objective of this study was to develop an autoclaved light concrete （ALC） material with ultra-thermal insulation property and to investigate the relationship between its physical characteristics and mechanical properties. Through tests of dry bulk density and compressive strength, relationship of physical characteristics and mechanical properties of samples were studied, resulting in a material with ultra-thermal insulation property. Scanning electron microscope （SEM） and energy-dispersive X-ray spectroscopy （EDX） were applied to analyze the micro-morphology and elemental composition of samples. To identify the product phases, X-ray diffraction （XRD） was engaged. The test results showed that compressive strength and thermal coefficient were reduced with the increasing of aluminum powder within the mixtures. As a result the optimal thermal coefficient and compressive strength of samples were improved to 0.061 W/（m·k） and 1.2 MPa, respectively. SEM, EDX and XRD analyses showed that calcium silicate hydrate and tobermorite crystal were main resultant phases.

关键词： autoclaved light concrete ultra-thermal insulation microscopic appearance and phase analysis tobermorite crystal

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：