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| 1 | Extraction and Crystal Structure of Karounidiol显示文摘The title compound of karounidiol (C30H48O2), a main active triterpene component of snakegourd seed, was isolated from unsaponifiable matter of the seed oil of Trichosanthes kirilowii Maxim., and characterized by X-ray diffraction analysis. It crystallizes in orthorhombic system, space group P212121 with C30H48O2CH3OHH2O (C31H54O4), a = 7.515(1), b = 14.407(1), c = 27.799(2) , V = 3009.8(5) 3, Z = 4, Dx = 1.087 g/cm3, Mr = 490.77, F(000) = 1088 and = 0.086 mm-1. The final R = 0.0840 and wR = 0.2289 for 2752 observed reflections (|F|2 ≥ 2|F|2). The molecular crystal structure of karounidiol shows relative stereochemistry of (3,13,14, 20)-3,29-dihydroxy-13-methyl-26-norolean-7,9(11)-diene. The molecule is composed of five six- membered rings with ring junctures of A/B trans, C/D trans and D/E cis. | CHAOZhi-Mao WANGCheng | 2003 | Chinese Journal of Structural Chemistry2003，22，4： | 7 |
| 2 | Microstructures and characteristics of deep trap levels in ZnO varistors doped with Y_2O_3显示文摘In this paper discussions on ZnO based varistor ceramics doped with different ratios of Y2O3 are presented.Analysis on the phase and microstructures of the samples indicates that an additional phase is detected in the samples doped with Y2O3,and the average grain size of the specimens decreases from about 9.2μm to 4.5μm,with an increase in the addition of Y2O3 from 0 mol%to 3 mol%.The corresponding varistor’s voltage gradient markedly increases from 462 V/mm to 2340 V/mm,while the nonlinear coefficient decreases from 22.3 to 11.5,respectively.Furthermore,the characteristics of deep trap levels in these ZnO samples are investigated by measuring their dielectric spectroscopies.The trap energy level and capture cross section evaluated by relaxation peak of the Cole-Cole plot vary slightly as the addition of Y2O3 increases.These traps may be ascribed to the intrinsic defects of ZnO lattice. | LIU Jun 1 ,HU Jun 1 ,HE JinLiang 1 ,LIN YuanHua 2 &LONG WangCheng 1 1State Key Laboratory of Power Systems,Department of Electrical Engineering,Tsinghua University,Beijing 100084,China 2State Key Laboratory of New Ceramics and Fine Processing,Department of Material Science and Engineering,Tsinghua University, Beijing 100084,China | 2009 | Science China(Technological Sciences)2009，52，12： | 5 |
| 3 | COMBINED DAMAGE FRACTURE CRITERIA FOR PIEZOELECTRIC CERAMICS显示文摘Mechanical and electrical damages are introduced to study the fracture mechanics of piezoelectric ceramics in this paper. Two kinds of piezoelectric fracture criteria are established using the method of least squares combined with a damage analysis of the well-known piezoelectric fracture experiments of Park and Sun’s. One is based on a linear combination of the mechanical and electrical damages and the other on their nonlinear combination. When the combined damage D is up to its critical value Dc, piezoelectric fracture occurs. It is found from the qualitative comparison of the numerical results with the experimental data that the nonlinearly combined damage fracture criterion can give a better prediction of piezoelectric fracture. And it is concluded from the nonlinearly combined damage fracture criterion that a negative electric feld impedes fracture whereas the efect of a positive electric feld on fracture depends on its magnitude. | YangXinhua ChenChuanyao HuYuantai WangCheng | 2005 | Acta Mechanica Solida Sinica2005，18，1： | 4 |
| 4 | Effects of manganese dioxide additives on the electrical characteristics of Al-doped ZnO varistors显示文摘The effects of manganese dioxide (MnO 2 ) additives on the electrical characteristics of the Al-doped ZnO varistors are investigated. The leakage current densities of the samples decrease first and then increase again with the increase of the amount of MnO 2 additives. Correspondingly, the nonlinear coefficients of the samples keep on increasing and then decrease. In addition, the donor densities increase monotonously with the amount of the doped MnO 2 increasing. The effects of MnO 2 additives on the electrical characteristics of the samples are different from the conclusion of previous literatures. The reasons of the distinct effects are supposed to be related with the donor and interface state densities of the samples. | LONG WangCheng HU Jun HE JinLiang LIU Jun ZENG Rong | 2011 | Science China(Technological Sciences)2011，54，8： | 3 |
| 5 | The dependence of sintering temperature on Schottky barrier and bulk electron traps of ZnO varistors显示文摘In order to investigate the influence of sintering temperature on the Schottky barrier and bulk electron traps of ZnO varistors,ZnO-Bi2O3 based varistor ceramic samples were sintered at 1000,1100,1200 and 1300°C,respectively.The measured results indicate that the sample sintered at 1300°C possesses the lowest voltage gradient and nonlinear coefficient,compared with other samples.The barrier height of the samples decreased as the sintering temperature increased,which resulted in the deterioration of nonlinearity.Furthermore,two bulk electron traps determined by admittance spectroscopy were generally independent of sintering temperature,which indicated that these two traps might originate from the intrinsic defects in ZnO lattice. | LIU Jun HE JinLiang HU Jun LONG WangCheng | 2011 | Science China(Technological Sciences)2011，54，2： | 3 |
| 6 | Al2O3 supported hybrid Pd-CeO2 colloidal spheres and its enhanced catalytic performances for methane combustion显示文摘Fabrication of novel nano-catalyst with improved activity and stability has been a hot topic in heterogeneous catalysis. Herein a novel approach was designed to synthesize Pd-CeO2 colloidal assembled spheres(CASs) in one-pot fashion. The Pd clusters were encompassed by the CeO2 nanocrystals with a high dispersity. Based on this hybrid structure, the Pd/ceria interface area can be greatly improved. After Pd-CeO2 CASs was supported on γ-Al2O3, its catalytic activity for CH4 combustion was evaluated. The result shows that Al2O3 supported Pd-CeO2 CASs exhibits an improved catalytic activity and stability,compared to the Pd/CeO2 catalyst prepared by impregnation method. The results of several characterization techniques indicate that the enhanced catalytic activity of Al2O3 supported Pd-CeO2 CASs can be attributed to the more interfacial Pd-O-Ce species and the more surface active oxygen species. | Xinwei Yang Chenhao Du Yanglong Guo Yun Guo Li Wang Yunsong Wang Wangcheng Zhan | 2019 | Journal of Rare Earths2019，37，7： | 2 |
| 7 | Catalytic wet oxidation of N,N-dimethyl formamide over ruthenium supported on CeO_2 and Ce_(0.7)Zr_(0.3)O_2 catalysts显示文摘A series of Ru supported on CeO_2 and Ce_(0.7)Zr_(0.3)O_2(CeZrO) was prepared by incipient-wet impregnation method and investigated in the catalytic wet oxidation of N,N-dimethyl formamide(DMF) in batch reactor. The physicochemical property of the catalysts was characterized by Brunauer-Emmett-Teller(BET), X-ray diffraction(XRD), H_2 temperature-programmed reduction(H_2-TPR), X-ray photoelectron spectroscopy(XPS) and thermogravimetry(TG). Compared with 3%Ru/CeO_2, 3%Ru/Ce_(0.7)Zr_(0.3)O_2 catalyst exhibits much higher performance for DMF degradation due to the promotion of Ru dispersion and the transfer of active oxygen, and 99% DMF conversion and 97% COD elimination are obtained at 453 K,2.5 MPa oxygen pressure after 5 h. The reaction mechanism of DMF degradation was suggested. The carbonaceous species deposition and oxidation of Ru can be responsible for catalyst deactivation. And the catalyst activity can be recovered by air calcination and H_2 reduction. | Jiawen Gong Dongzhi Li Li Wang Wangcheng Zhan Yanglong Guo Yunsong Wang Yun Guo | 2019 | Journal of Rare Earths2019，37，3： | 2 |
| 8 | Understanding the role of tungsten on Pt/CeO_(2)for vinyl chloride catalytic combustion显示文摘Spherical CeO_(2)synthesized by the hydrothermal process was used as support to prepare Pt/WO_(3)/CeO_(2),and the effects of tungsten(W)contents on activity,stability and polychlorinated by-products were investigated to understand the role of W for vinyl chloride(VC)catalytic oxidation.The introduction of12 wt%W to Pt/CeO_(2)(P12 WC)exhibits the highest catalytic activity with 90%conversion of VC at 250℃,meanwhile the stability improves and the polychlorinated by-products in the tail gas significantly decrease due to the removal of dissociated Cl species in the formation of HCl.The beneficial effects of W on Pt/CeO_(2)are closely related to the chemical state of Pt,redox and surface acid sites distribution.The doped W not only makes Pt disperse evenly on the support with the high valence,but also weakens the interaction between Pt and CeO_(2)by the formation of Pt-O-W and Pt-O-W-O-Ce species,which facilitates oxygen mobility.In addition,the modification of W species also significantly increases the surface acidity amount and changes the distribution of acid sites. | Qifeng Zhang Zhengbo Zhou Tian Fang Han Gu Yanglong Guo Wangcheng Zhan Yun Guo Li Wang | 2022 | Journal of Rare Earths2022，40，9： | 2 |
| 9 | H2SO4-Bassisted hydrothermal preparation of gamma-AlOOH nanorods显示文摘 | Taobo He Lan Xiang Wangcheng Zhu Shenlin Zhu | 2008 | Materials Letters2008，62，29： | 1 |
| 10 | Oriented structure and crystallography of directionally solidified LaB6ZrB2 eutectic显示文摘 | CHEN Changming ZHOU Wangcheng ZHANG Litong | 1998 | J Am Ceram Soc1998，81，1： | 1 |
| 11 | Characterization of LaB6ZrB2 eutectic composite growthby the floating zone method显示文摘 | CHEN Changming ZHOU Wangcheng ZHANG Litong | 1998 | J Cryst Growth1998，191，3： | 1 |
| 12 | 显示文摘 | GAOYong(高勇) WANGCheng(王诚) PUWei-Hua(蒲薇华) etal | | Dianchi0，，： | 1 |
| 13 | Synthesis of Lanthanum-Doped MCM-48 Molecular Sieves and Its Catalytic Performance for the Oxidation of Styrene显示文摘 | Zhan Wangcheng Guo Yanlnng Wang Yanqing | 2007 | Journal of Physical Chemistry:B2007，111，12： | 1 |
| 14 | Migration of Heavy Metal Elements in Reclaimed Irrigation Water-Soil-Plant System and Potential Risk to Human Health显示文摘[Objectives]To study the impact of heavy metal pollution of soil and plants during the process of reclaimed water for irrigation of green land in arid areas and the potential health risks to humans during use.[Methods]Taking Zhongwei City in Ningxia,a typical arid area,as the research area,the irrigation water,soil and green grass in the reclaimed water irrigation region and the original green water irrigation region were sampled,the heavy elements Hg,As,Zn,Pb,Cd,Cr were detected,and the Nemerow method,biological absorption coefficient,and health risk assessment were employed to evaluate the degree of soil pollution,plant absorption capacity,and human health risks.[Results]Compared with the original green water,the Hg,Cd,and Cr pollution of the reclaimed water irrigated green land was higher,the As,Zn,Pb pollution was lower,and the content of Hg and Cd was higher than the environmental background values of soil in Ningxia;the Cr content exceeded the risk intervention values of the first type of land in the Soil Environmental Quality—Risk Control Standard for Soil Contamination of Development Land(GB 36600-2018).Compared with the original green water irrigation region,it is found that the reclaimed water irrigation reduced the heavy metal pollution of the soil to a certain extent.The heavy metal content of tall fescue grass(Festuca arundinacea)in the reclaimed water irrigation region was Zn,Cr,Pb,As,Cd,and Hg from high to low;the order of the biological absorption coefficient was Cd>As>Zn>Pb>Hg>Cr;irrigation water exerted a certain effect on the content of heavy metals in plants and the biological absorption coefficient through the soil.Using the health risk assessment method recommended by Environmental Protection Agency of the United States of America(USEPA),it was found that the reclaimed water has the highest risk through the inhalation route,and the occupational population has a higher risk of skin contact with soil and plants.[Conclusions]This study is intended to provide data support and theoretical basis for the environmental safety risk research of the application of reclaimed water in arid areas to urban greening. | Zixi LIU Juncang TIAN Wangcheng LI Lian TANG Jie WANG Haiyan GAO | 2021 | Asian Agricultural Research2021，13，10： | 1 |
| 15 | 显示文摘 | WANGCheng(王程) SHIHui-Dheng(施惠生) LIYan(李艳) etal | 2011 | 无机化学学报2011，27，： | 1 |
| 16 | Reduction of excess sludge production in sequencing batch reactor (SBR) by lysis–cryptic growth using homogenization disruption显示文摘 | Wangcheng Lan Yiyong Li Qi Bi Yongyou Hu | 2013 | Bioresource Technology2013，，： | 1 |
| 17 | 显示文摘 | WangCheng(王成) JuShaohua(巨少华) XunShilling(荀淑玲)etal | 2009 | 材料导报2009，23，2： | 1 |
| 18 | Synthesis of Lanthanum-doped MCM-48 molecular sieves and its catalytic performance for the oxidation of styrene显示文摘 | Zhan Wangcheng Guo Yanglong Wang Yanqin | 2007 | J Phys Chem B2007，111，12： | 1 |
| 19 | Jahn-Teller distortion assisted interstitial nitrogen engineering:Enhanced oxygen dehydrogenation activity of N-doped Mn_(x)Co_(3-x)O_(4) hierarchical micro-nano particles显示文摘Rational design of earth-abundant transition metal oxides catalysts is highly desirable for developing sustainable chemical processes.Herein,we demonstrate a prospective interstitial nitrogen engineering for fabricating oxygen vacancies(OVs)-rich nitrogen-doped-Mn_(x)Co_(3-x)O_(4)(N-Mn_(x)Co_(3-x)O_(4))oxide catalyst,in which the ratio of OVs concentration of N-Mn_(x)Co_(3-x)O_(4)to Mn species is as high as 1:1,according to the characterizations of X-ray absorption(XAS)and X-ray photoelectron(XPS)spectroscopies.The promising strategy of interstitial nitrogen engineering through lattice distortion caused by the Jahn-Teller effect can significantly increase the amount of interstitial nitrogen.The resulting catalyst enables an additive-free aerobic dehydrogenation coupling of aromatic amine to afford azo compounds with>99%yield and>99%selectivity at 60☆.We observed the superb catalytic activity is promoted by the enhanced oxygen mobility in OVs,which were created by the interstitial nitrogen in the catalyst matrix.The presence of interstitial nitrogen in transition metal oxides in this study shows how the manipulation of catalyst matrix can increase the OV sites to promote aerobic oxidation reaction. | Yangxin Jin Fengfeng Li Peixin Cui Yun Yang Qingping Ke Minh Ngoc Ha Wangcheng Zhan Fei Ruan Chao Wan Zhao Lei Van Noi Nguyen Wei Chen Jun Tang | 2021 | Nano Research2021，14，8： | 1 |
| 20 | H2SO4- assisted hydrothermal preparation of gamma-AlOOH nanorods显示文摘 | HE Taobo XIANG Lan ZHU Wangcheng | 2008 | Materials Letters2008，62，1718： | 1 |
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