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Chinese Journal of Chemistry 2023年第3期41卷 294-300页

作者： Jian Chen gao deng You Wang Shaolin Zhu State Key Laboratory of Coordination Chemistry Jiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringNanjing UniversityNanjingJiangsu210093 China School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiangHenan453007 China

NiH-catalyzed multicomponent reductive hydrofunctionalization of alkenes is an attractive but poorly explored approach to rapidly increasing molecular *** this process,the selective generation of the desired product can be ***,we report that a highly chemo-,regio-and enantioselective reductive hydrocarbonylation of alkenes has been achieved using a chloroformate ester as a source of CO.A wide range of structurally diverseα-hydroxy ketones,privileged structural elements in bioactive molecules and useful building blocks,were obtained from such reactions with high enantiomeric purity.

关键词： Alkenes Asymmetric catalysis Hydrofunctionalization Multicomponent reactions Nickel Nickel hydride Synthetic methods Hydrocarbonylation

Modification of nanometer calcium carbonate for water-borne architectural coatings

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Journal of China University of Mining and Technology 2008年第1期18卷 76-81页

作者： WANG Xun-qiu JIANG deng-gao School of Chemical Engineering Zhengzhou University Zhengzhou Henan 450002 China

A kind of modifier was synthesized to modify the surface of nanometer calcium carbonate （abbreviated as nano-CaCO3）, which is used in architectural coatings. The modification technology of the nano-CaCO3 was studied through orthogonal experimental methods. The factors studied were rotation speed, modifier dosage, emulsification temperature, emulsification time and heat aging time after emulsification. Optimized conditions for modification of the surface were： rotation speed 16000 r/min; modifier dosage 3%; emulsification temperature 75 ℃; emulsification time 60 min and aging time 40 min. The modified nano-CaCO3 was also studied by size-distribution measurements, transmission electron microscopy, infrared spectroscopy and thermal analysis. The results show that the size distribution of the modified nano-CaCO3 is uniform and that there are chemi-sorption and physi-sorption between the nano-CaCO3 and the modifier. Compared to traditional architectural coatings without nano-CaCO3, the nanometer composite coatings are obviously improved in respect to dirt resistance, scrub resistance, thixotropy, water resistance, alkalinity resistance and aging resistance.

关键词： nanometer calcium carbonate surface modification modifier architectural coatings

Global Existence of Solutions for the Kawahara Equation in Sobolev Spaces of Negative Indices

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Acta Mathematica Sinica,English Series 2007年第8期23卷 1435-1446页

作者： Hua WANG Shang Bin CUI Dong gao deng Department of Mathematics Sun Yat-Sen University Guangdong 510275 P. R. China

We first prove that the Cauchy problem of the Kawahara equation, δtu ＋ uδxu ＋βδx^3u＋γδx^5u = 0, is locally solvable if the initial data belong to H^r（R） and r〉 r≥-7/5, thus improving the known local well-posedness result of this equation. Next we use this local result and the method of ＂almost conservation law＂ to prove that global solutions exist if the initial data belong to H^r（R） and r〉-1/2.

关键词： Kawahara equation Cauchy problem global solution almost conservation law

Seismic stability and permanent displacement of landfill along liners

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Science China(Technological Sciences) 2008年第4期51卷 407-423页

作者： CHEN YunMin gao deng ZHU Bin CHEN RenPeng MOE Key Laboratory of Soft Solis and Geoenvironmental Engineering Zhejiang UniversityHangzhou 310027China

The three-part wedge limit equilibrium method for seismic stability analysis of the landfill along liners is presented. The approximate solutions of the factor of safety and the yield acceleration coefficient are obtained. Parametric studies show that the interface strength of liners, the shear strength of waste and the height of retaining wall can influence the seismic stability of landfill along liners. The density and the shear wave velocity of the field waste are obtained by the borehole investigation and the spectral analysis of surface wave (SASW), respectively. The strain-dependent shear modulus and damping ratio of the artifical waste are obtained by the moderate-scale dynamic triaxial tests. The onedimensional (1D) equivalent linear dynamic response analysis is used to calculate the horizontal equivalent seismic coefficient-time history of the sliding landfill during earthquake. The seismic permanent displacement of the landfill along liners with different site conditons and heights is evaluated by the Newmark method. The catculated results show that ratio of ky /kmax, site conditions, the amplitude and frequency content of the bedrock motion can affect the seismic permanent displacement of the landfill along liners in some degree. Finally, the seismic stability and permanent displacements of three expanded configurations of a certain landfill case are analyzed.

关键词： landfill liner seismic stability permanent displacement Newmark method

Model tests on interaction between soil and geosynthetics subjected to localized subsidence in landfills

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第6期13卷 433-444页

作者： Bin ZHU deng gao Jun-chao LI Yun-min CHEN MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Department of Civil EngineeringZhejiang UniversityHangzhou 310058China

In a landfill, excessive tensile strains or failure of the liner system due to localized subsidence underneath the geosynthetic liner, is a concern in design and operation of the landfill. The localized subsidence can be commonly withstood by reinforcements such as geogrids. A total of nine model tests were carried out to study the influence of soil arching in overburden sandy soil on the geosynthetics and the interaction between the soil and the geosynthetics. The localized subsidence was modeled by a strip trapdoor under the geosynthetic reinforcements. The reinforcement includes several layers of polyvinylchlorid （PVC） membrane or both PVC membrane and a compacted clay layer. Test results show that the vertical soil pressure acting on the geosynthetics within the subsidence zone is strongly related to the deflection of the geosynthefics. The soil pressure acting on the deflected geosynthetics will decrease to a minimum value with respect to its deflection if the final deflection is large enough, and this minimum value is almost independent of the overburden height. Otherwise, the deflection of geosynthetics cannot result in a full degree of soil arching, and the soil pressure within the subsidence zone increases with the increase of overburden height. Deflections and strains of the geosynthetics obviously decrease with the increase of their tensile stiffness. The presence of a compacted clay layer buffer can therefore reduce both deflections and strains of the geosynthetics. Finally, a composite liner structure is recommended for landfills to withstand the localized subsidences.

关键词： Landfill Soil arching Trapdoor Model test Geosynthetics

Global Existence of Solutions for the Cauchy Problem of the Kawahara Equation with L^2 Initial Data

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Acta Mathematica Sinica,English Series 2006年第5期22卷 1457-1466页

作者： Shang Bin CUI Dong gao deng Shuang Ping TAO Department of Mathematics Sun Yat-Sen University Guangzhou 510275 P. R. China Department of Mathematics Northwest Normal University Lanzhou 730070 P. R. China

In this paper we study solvability of the Cauchy problem of the Kawahara equation 偏导dtu ＋ au偏导dzu ＋ β偏导d^3xu ＋γ偏导d^5xu = 0 with L^2 initial data. By working on the Bourgain space X^r,s（R^2） associated with this equation, we prove that the Cauchy problem of the Kawahara equation is locally solvable if initial data belong to H^r（R） and -1 〈 r ≤ 0. This result combined with the energy conservation law of the Kawahara equation yields that global solutions exist if initial data belong to L^2（R）.

关键词： Kawahara equation Cauchy problem global solution

Research on Development of Agricultural Geographic Information Ontology

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Journal of Integrative Agriculture 2012年第5期11卷 865-877页

作者： HUANG Yong-qi CUI Wei-hong ZHANG Yang-jian deng gao-yan Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 P.R. China Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization Huanggang Normal University Huanggang 438000 P.R.China Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 P.R.China Huanggang Normal University Huanggang 438000 P.R. China

This paper first analyzes the reason that agricultural geographic information gives rise to semantic heterogeneity and solution thereof. Although OWL （web ontology language） is the standard of ontology representation language in semantic web, it is insufficient in representing spatial characteristics, especially spatial relationship. Consequently it is pointed out to build geo-ontology by virtue of three theories such as mereology, location theory and topology in this paper. This paper introduces mereology, location theory and topology, and then discusses how to adopt these three theories to build geo-ontology. The outcome of experiment shows that solution put forward by this paper is feasible.

关键词： agricultural geographic information semantic heterogeneity mereology location topology geo-ontology

Environmentally Tough and Stretchable MXene Organohydrogel with Exceptionally Enhanced Electromagnetic Interference Shielding Performances

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Nano-Micro Letters 2022年第5期14卷 77-91页

作者： Yuanhang Yu Peng Yi Wenbin Xu Xin Sun gao deng Xiaofang Liu Jianglan Shui Ronghai Yu School of Materials Science and Engineering Beihang UniversityBeijing 100191People’s Republic of China Science and Technology on Optical Radiation Laboratory Beijing Institute of Environmental FeaturesBeijing 100854People’s Republic of China Science and Technology on Electromagnetic Scattering Laboratory Beijing Institute of Environmental FeaturesBeijing 100854People’s Republic of China

Conductive hydrogels have potential applications in shielding electromagnetic(EM)radiation interference in deformable and wearable electronic devices,but usually suffer from poor environmental stability and stretching-induced shielding performance *** organohydrogels can improve the environmental stability of materials,their development is at the expense of reducing electrical conductivity and thus weakening EM interference shielding ***,a MXene organohydrogel is prepared which is composed of MXene network for electron conduction,binary solvent channels for ion conduction,and abundant solvent-polymer-MXene interfaces for EM wave *** organohydrogel possesses excellent anti-drying ability,low-temperature tolerance,stretchability,shape adaptability,adhesion and rapid self-healing *** effective strategies have been proposed to solve the problems of current organohydrogel shielding *** reasonably controlling the MXene content and the glycerol-water ratio in the gel,MXene organohydrogel can exhibit exceptionally enhanced EM interference shielding performances compared to MXene hydrogel due to the increased physical cross-linking density of the ***,MXene organohydrogel shows attractive stretching-enhanced interference effectiveness,caused by the connection and parallel arrangement of MXene *** well-designed MXene organohydrogel has potential applications in shielding EM interference in deformable and wearable electronic devices.

关键词： Electromagnetic interference shielding MXene organohydrogel Stretchable conductive film Anti-drying ability Lowtemperature tolerance

Double Roots of Mandibular Premolar in Full-mouth Periapical Films

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Chinese Medical Sciences Journal 2015年第3期30卷 174-178页

作者： Ling-jia Kong Kuo Wan deng-gao Liu Department of Stomatology Peking Union Medical College HospitalChinese Academy of Medical Sciences & Peking Union Medical College Department of Radiology Peking University School of Stomatology

Objective To evaluate the incidence of two-rooted mandibular premolar morphology using full-mouth periapical film series in a Chinese population,with particular emphasis on bilateral incidence,so as to provide a clinical anatomical basis for root canal treatment in mandibular *** A total of 2015 patients who underwent dental treatment and had full mouth periapical radiographs at the Peking University School of Stomatology from April 2011 to April 2012 were enrolled in this *** experienced dentists reviewed the patients' periapical films and classified the root morphology of mandibular premolars *** incidence of unilateral and bilateral double roots were recorded and calculated,including confirmed and suspected bucco-lingual root *** In terms of the morphology of two-rooted mandibular first premolars,of the 2015 cases with complete root formation,two-rooted first premolars were detected in 120 cases,with a total number of 159 *** to the number of teeth,the overall incidence of double roots was 4.03%(159/3972).In terms of the morphology of two-rooted mandibular second premolars,of the 2015 cases with complete root formation,two-rooted second premolars were detected in 24 cases,with a total number of 33 *** to the number of teeth,the overall incidence of double roots was 0.85%(33/3880).Conclusions The roots of mandibular premolars display specific morphological *** on a large sample,we observed and calculated not only the occurrence rate of bucco-lingual and mesio-distal double roots in first and second mandibular premolars,but also the incidence of unilateral or bilateral double roots within the same *** findings could provide useful information on the anatomical structure of mandibular premolars for endodontic,prosthodontic and surgical procedures,and could improve the quality of treatment and reduce complications.

关键词： first mandibular premolar second mandibular premolar double roots full-mouth periapical film

Dehydration Characteristics of C-S-H with Ca/Si Ratio 1.0 Prepared Via Precipitation

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Journal of Wuhan University of Technology(Materials Science) 2018年第3期33卷 619-624页

作者：何永佳 ZHENG Xiaohui 吕林女 YU Shumei deng gao HU Shuguang State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology) Wuhan 430070 China School of Materials Science and Engineering Wuhan University of Technology Wuhan 430070 China Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics (School of Science Wuhan University of Technology) Wuhan 430070 China

Calcium silicate hydrate（C-S-H） with Ca/Si ratio 1.0 was prepared via precipitation in solution and heated at various temperatures to investigate its dehydration behavior. The dehydration, structural collapse and recrystallization characteristics of C-S-H and its microstructural change during heating process were investigated by XRD, SEM, Raman and TG-DSC techniques. C-S-H gradually lost non-evaporable water upon heating, about 50% and 80% non-evaporable water was removed below 200 and 400 ℃, respectively, and the rest was removed up to about 1 000 ℃. At 400 ℃, dehydrated C-S-H exhibited the increasing disordering of calcium/silicon environment and the decreasing symmetrical bending vibration of Si-O-Si of Q^2 silicate chains. At 650 ℃ non-bridging oxygen atoms（O（non）） attached to silicon were almost removed, and significant structural change occurred, and at 815 ℃ C-S-H dehydrated to wollastonite.

关键词： C-S-H heat dehydration structure morphology