检索结果-南通市图书馆

Preparation of a novel PAN/cellulose acetate-Ag based activated carbon nanofiber and its adsorption performance for low-concentration SO_2

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2015年第4期22卷 437-445页

作者： yan-bo wu Jun Bi Ting Lou Tie-ben Song Hong-quan Yu School of Environmental and Chemical Engineering Dalian Jiaotong University

Polyacrylonitrile （PAN）, PAN/cellulose acetate （CA）, and PAN/CA-Ag based activated carbon nanofiber （ACNF） were prepared using electrostatic spinning and further heat treatment. Thermogravimetrylifferential scanning calorimetry （TG-DSC） analysis indicated that the addition of CA or Ag did not have a significant impact on the thermal decomposition of PAN materials but the yields of fibers could be improved. Scanning electron microscopy （SEM） analysis showed that the micromorphologies of produced fibers were greatly influenced by the viscosity and conductivity of precursor solutions. Fourier transform infrared spectroscopy （FT-IR） analysis proved that a cyclized or trapezoidal structure could form and the carbon scaffold composed of C=C bonds appeared in the PAN-based ACNFs. The characteristic dif- fraction peaks in X-ray diffraction （XRD） spectra were the evidence of a turbostratic structure and silver existed in the PAN/CA-Ag based ACNF. Brurmer-Emmett-Teller （BET） analysis showed that the doping of CA and Ag increased surface area and micropore volume of fi- bers; particularly, PAN/CA-Ag based ACNF exhibited the best porosity feature. Furthermore, SO2 adsorption experiments indicated that all the three fibers had good adsorption effects on lower concentrations of SO2 at room temperature; especially, the PAN/CA-Ag based ACNF showed the best adsorption performance, and it may be one of the most promising adsorbents used in the fields of chemical industry and en- vironment protection.

关键词： activated carbon nanofibers polyacrylonitrile electrospinning adsorption sulfur dioxide

Preparation of metal oxide doped ACNFs and their adsorption performance for low concentration SO_2

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2013年第11期20卷 1102-1106页

作者： Hong-quan Yu yan-bo wu Tie-ben Song Yue Li Yu Shen College of Environmental and Chemical Engineering Dalian Jiaotong University

Metal oxide （TiO2 or Co304） doped activated carbon nanofibers （ACNFs） were prepared by electrospinning. These nanofibers were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and Brunner- Emmett-Teller method （BET）. The results show that the average diameters of ACNFs were within the range of 200-500 nm, and the lengths were several tens of micrometers. The specific surface areas were 1146.7 m2/g for TiO2-doped ACNFs and 1238.5 m2/g for Co304-doped ACNFs, respectively. The electrospun nanofibers were used for adsorption of low concentration sulfur dioxide （SO2）. The results showed that the adsorption rates of these ACNFs increased with an increase in SO2concentration. When the SO2 concentration was 1.0 μg/mL, the adsorption rates of TiO2-doped ACNFs and Co3Oa-doped ACNFs were 66.2% and 67.1%, respectively. The adsorption rate also increased as the adsorption time increased. When the adsorption time was 40 min, the adsorption rates were 67.6% and 69.0% for TiO2-doped ACNFs and Co304-doped ACNFs, respectively. The adsorption rate decreased as the adsorption temperature increased below 60℃, while it increased as the adsorption temperature increased to more than 60℃.

关键词： activated carbon nanofibers metal oxides electrospinning adsorption sulfur dioxide

Origins of regio-and stereoselectivity in Cu-catalyzed alkyne difunctionalization with CO_(2) and organoboranes

在线全文

学校读者我要写书评

暂无评论

Organic Chemistry Frontiers 2022年第4期9卷 1033-1039页

作者： Lingfei Hu Han Gao yanlei Hu Xiangying Lv yan-bo wu Gang Lu School of Chemistry and Chemical Engineering Key Laboratory of Colloid and Interface ChemistryMinistry of EducationShandong UniversityJinanShandong 250100China Key Lab for Materials of Energy Conversion and Storage of Shanxi Province and Key Lab of Chemical Biology and Molecular Engineering of Ministry of Education Institute of Molecular ScienceShanxi UniversityTaiyuanShanxi 030006China

The mechanism and origins of regio-and stereoselectivities of Cu-catalyzed alkyne difunctionalization with CO_(2) and trialkyl boranes were computationally *** results show that the vicinal addition to alkyne is disfavored due to the kinetical inertness of the alkyl copper *** favored geminal addition proceeds through the cationic Cu-mediated stereoselective 1,2-migration *** energy decomposition analysis indicates that theσ)(πPauli repulsion is the dominant factor for controlling the stereoselectivity.

关键词： catalyzed alkyl addition

Injection of a Self-propelled Polymer into a Small Circular Cavity

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 Journal of Polymer Science 2024年第6期42卷 886-894页

作者： Chao Wang yan-Li Zhou Xiao yang Fan wu Meng-bo Luo Department of Physics Taizhou UniversityTaizhou318000China Department of Physics Zhejiang UniversityHangzhou310027China

The injection of a polymer chain into a small circular cavity under tangential self-propelled force is studied by using Langevin dynamics *** indicate that the injection dynamics of the active polymer shows strong correlation with the polymer conformation inside the cavity depending on the polymer rigidity(k_(b)).The injection timeτvaries nonmonotonously with increasing k_(b),and reaches its minimum at k_(b)^(*).When k_(b) is small(k_(b)≪k_(b)^(*)),the polymer is nearly random coil in the cavity,and spends a long time at the final stage of the injection process due to the large repulsion between monomers inside the *** k_(b) is moderate(k_(b)∼k_(b)^(*)),the part of polymer inside the cavity forms spiral configuration under the tangential active force,and the whole polymer moves synchronously with a constant velocity during the injection process,leading to a small injection *** k_(b) is large(k_(b)≫k_(b)^(*)),the polymer is nearly straight at the initial stage of the injection process,and takes a long time to bend itself,leading to a large injection time.

关键词： Active Polymer Injection Dynamics Simulation

在线全文

学校读者我要写书评

暂无评论

氧化钒薄膜的性能和制备

压电与声光 2006年第2期28卷 179-181,184页

作者：晏伯武黄石理工学院计算机与信息工程系

为制备低相变温度、高相变特性的氧化钒薄膜,分析了氧化钒的结构,及其结构决定的特有相变,相变前后独特的光电性能及其应用。比较研究了各种制备方法,得到最低相变温度、最高的电阻变化率和电阻温度系数分别达24℃、105-、5.2%K-1,研究... 详细信息

为制备低相变温度、高相变特性的氧化钒薄膜,分析了氧化钒的结构,及其结构决定的特有相变,相变前后独特的光电性能及其应用。比较研究了各种制备方法,得到最低相变温度、最高的电阻变化率和电阻温度系数分别达24℃、105-、5.2%K-1,研究表明,掺杂改性及新的成膜工艺的研究是氧化钒薄膜的发展方向。

关键词：氧化钒薄膜制备性能

PBSZT压电陶瓷机械损耗和介电损耗的研究

在线全文

学校读者我要写书评

暂无评论

压电与声光 2008年第3期30卷 308-310,314页

作者：晏伯武黄石理工学院计算机学院

为探索Pb0.9Ba0.05Sr0.05(Sn1/3Nb2/3)0.06(Zn1/3Nb2/3)0.06Ti0.44Zr0.44O3+0.5%Sb2O3+0.5%Mn(NO3)2(质量分数)铅基压电陶瓷材料的损耗机理,进行成型工艺、烧结工艺的实验研究,实验制备的凝胶注模成型样品得到较低的介电损耗tanδ为0.25%,而干压成型得到更大的品质因数Qm为2 065。从微观结构角度来看,机械损耗主要依赖陶瓷微观结构的致密性,而tanδ较多的依赖于陶瓷结构的均匀性。

关键词：压电陶瓷介电损耗掺杂锆钛酸铅

Breakdown of Valence Shell Electron Pair Repulsion Theory in an H-bond-Stabilized Linear sp-Hybridized Sulfur

在线全文

学校读者我要写书评

暂无评论

CCS Chemistry 2021年第10期3卷 2584-2590页

作者： Jin wu bo Jin Xiang Wang Yayun Ding Xiao-Li Wang Dandan Tang Xiaohong Li Jie Shu Dong-Sheng Li Qipu Lin yan-bo wu Tao wu College of Chemistry Chemical Engineering and Material SciencesSoochow UniversitySuzhou 215123 The Key Laboratory of the Materials for Energy Storage and Conversion of Shanxi Province Institute of Molecular ScienceShanxi UniversityTaiyuan 030006 Testing and Analysis Centre Soochow UniversitySuzhou 215123 College of Materials and Chemical Engineering Hubei Provincial Collaborative Innovation Center for New Energy MicrogridKey Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion MaterialsChina Three Gorges UniversityYichang 443002 State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002

Exploring the unusual orbital hybridization types of atoms and their new connection modes contributes to the development of chemical bond theory and can inspire compounds with unique molecular *** sulfur(S)atoms(or anions)with sp3 hybridization in a bent-bridging mode are commonly observed in many inorganic and organic ***,sp-hybridized S species have,thus far,been extremely rare,and the linearly bridging mode has only been“forcibly”achieved with the aid of metal–S multiple bonds and/or significant steric hindrance from the surrounding organic ligands.

关键词： sp-hybridized sulfur linear coo rdinat ion hydrogen bond indium sulfide VSEPR theory

Simple preparation of C(CS)/g-C_(3)N_(4)/Co carbon aerogel and its catalytic performance for ammonium perchlorate

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

Defence Technology（防务技术） 2024年第3期33卷 186-196页

作者： Yujie yan bo Jin Rufang Peng State Key Laboratory of Environment-friendly Energy Materials School of Materials Science and EngineeringSouthwest University of Science and TechnologyMianyang621010China

Biomass chitosan(CS)was used as a template,graphitic phase carbon nitride(g-C_(3)N_(4))with high nitrogen content and certain catalytic activity was used as a dopant,and nano-transition metal cobalt(Co)was used as a catalytic center *** carbon aerogel(C(CS)/g-C_(3)N_(4)/Co)with a three-dimensional network-like structure was prepared by assembling the three materials through experimental operations such as freeze-drying and high-temperature *** was demonstrated by scanning and transmission characterization that the CS in the carbon aerogel could provide more active sites for the cobalt nanoparticles,and the doping of graphite-phase carbon nitride as a template dispersed the cobalt nanoparticles and changed the conductivity of the *** investigate the catalytic effect of carbon aerogel on ammonium perchlorate(AP),it was investigated by differential thermal analyzer and TG thermal *** carbon aerogel was very effective in catalyzing AP,and the 10 wt% content of the catalyst reduced the AP pyrolysis peak from 703.9 to 595.5 *** to further investigate the synergistic effect of the three materials,further carbon aerogels such as C(CS)/Co,g-C_(3)N_(4)/Co were prepared and applied to catalyze AP,and the same ratio reduced the AP pyrolysis peak by 98.1℃ and 97.7℃.This result indicates a synergistic effect of the assembly of the three materials.

关键词： g-C_(3)N_(4) Chitosan Co Ammonium perchlorate Pyrolysis kinetics

Transition-Metal-Free Allylic Defluorination Cross-Electrophile Coupling Employing Rongalite

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第12期42卷 1360-1366页

作者： Xiang-Long Chen Chun-yan wu Dong-Sheng yang bo-Cheng Tang Huai-Yu Wang Zhi-Cheng Yu Anling Li yan-Dong wu An-Xin wu National Key Laboratory of Green Pesticide International Joint Research Center for Intelligent Biosensor Technology and HealthCollege of ChemistryCentral China Normal UniversityWuhanHubei 430079China state Key Laboratory of Chemical Biology and Drug Discovery Department of Applied Biology and Chemical Technology The HongKong Polytechnic UniversityKowloonHong Kong SARChina Department of Clinical Laboratory Center for Gene Diagnosisand Program of Clinical Laboratory MedicineZhongnan Hospital of Wuhan UniversityWuhanHubei 430062China

Comprehensive Summary The conversion of CF3-alkenes to gem-difluoroalkenes using reductive cross-coupling strategy has received much attention in recent years,however,the use of green and readily available reducing salt to mediate these reactions remains to be *** this work,a concise construction of gem-difluoroalkenes,which requires neither a catalyst nor a metal reducing agent,was ***,a safe and inexpensive industrial product,was employed as both a radical initiator and *** procedure was compatible with both linear and cyclic diaryliodonium salts,enabling a wide variety of substrates(>70 examples).The utility of this approach was demonstrated through gram-scale synthesis and efficient late-stage functionalizations of anti-inflammatory drugs.

关键词： Defluoroarylation Transition metal free gem-Difluoroalkenes Rongalite Single electron transfer C-C coupling Redox reactions Cross-coupling