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One-pot Approach to the Conversion of Alcohols into α-Halo-α, β-unsaturated Esters

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Chinese Chemical Letters 2006年第3期17卷 329-332页

作者： Gui sheng DENG Chun yu liu College of Chemistry and Chemical Engineering Hunan Normal University Changsha 410081

The sequential oxidation-Horner-Wadsworth-Emmons reaction of alcohols to prepare α-Halo-α,β-unsaturated esters （halo =F, Cl） with middle to excellent （Z）-selectivity was developed.

关键词： Horner-Wadsworth-Emmons reaction,α-Halo-α,β--unsaturated esters alcohol one-pot approach synthesis.

Absorption and Fluorescence Emission Spectra of Molecules Containing Azo and/or Oxadiazole Units

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Chemical Research in Chinese Universities 2013年第4期29卷 776-781页

作者： WANG Chang-sheng yu Nan liu Peng School of Chemistry and Chemical Engineering Liaoning Normal University Dalian 116029 P. R. China

The ground state structures of a series of organic molecules containing azo and/or oxadiazole units were obtained by means of density functional theory B3LYP/6-3IG（d） method. The first singlet excited state structures were optimized by virtue of singlet-excitation configuration interaction CIS/6-31G（d） method. The absorption and fluorescence emission spectra were then evaluated via the time-dependent density functional theory B3LYP and PBE1PBE methods with 6-31 l＋＋G（3df,2p） basis set. The calculation results show that compared with those of their parent molecules A-H, B-H, C-H, D-H, the absorption and emission wavelength values of all the derivatives show red shifts. The derivatives containing both the oxadiazole and methoxyl units are good candidates for longer absorption wavelength materials. The effects of azo, oxadiazole, and methoxyl units on the absorption and emission wavelength were discussed.

关键词： Azo Azobenzene Oxadiazole Absorption spectrum Fluorescence emission spectrum Excited state

Transient fuel performance analysis of UO_(2)–BeO fuel with composite SiC coated with Cr cladding based on multiphysics method

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Nuclear Science and Techniques 2023年第12期34卷 93-108页

作者： Chun‑yu Yin Shi‑Xin Gao sheng‑yu liu Rong liu Guang‑Hui Su Li‑Bo Qian School of Nuclear Science and Technology Xi’an Jiaotong UniversityXi’an 710049China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610213China School of Electric Power South China University of TechnologyGuangzhou 510640China

The transient multiphysics models were updated in CAMPUS to evaluate the accident-tolerant fuel performance under accident *** is a fuel performance code developed based on *** simulated results of the UO_(2)–Zircaloy fuel performance under accident conditions were compared with those of the FRAPTRAN code and the experimental data to verify the correctness of the updated ***,multiphysics models of the UO_(2)–BeO fuel and composite SiC coated with Cr(SiC_(f)/SiC-Cr)cladding were implemented in ***,the fuel performance of the three types of fuel cladding systems under Loss of Coolant Accident(LOCA)and Reactivity Insertion Accident(RIA)conditions was evaluated and compared,including the temperature distribution,stress distribution,pressure evolution,and cladding failure *** results showed that the fuel temperature of the UO_(2) fuel under accident conditions without pre-irradiation was lower after being combined with SiC_(f)/SiC-Cr ***,the centerline and outer surface temperatures of the UO_(2)–BeO fuel combined with SiC_(f)/SiC-Cr cladding reduced further under accident *** cladding temperature increased after the combination with the SiC_(f)/SiC-Cr cladding under accident conditions with *** addition,the use of SiC_(f)/SiC-Cr cladding significantly reduced the cladding hoop strain and plenum pressure.

关键词： Accident condition Fuel performance UO2–BeO fuel SiCf/SiC-Cr cladding

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中国北方典型地区人群活动模式特色数据集

Chinese Medical Sciences Journal 2024年第1期39卷 69-73,I0007页

作者：杨意森刘盛宇梅亚园周全赵梅朵许群吴思竹中国医学科学院基础医学研究所北京协和医学院基础学院流行病与卫生统计学系北京100005 中国医学科学院北京协和医学院环境与健康研究中心北京100005 中国医学科学院北京协和医学院医学信息研究所医学数据共享研究室北京100020

本文介绍了《典型地区活动模式特色数据集》(Typical Regional Activity Patterns,TRAP),此数据集依托于“大气重污染成因与治理攻关项目”。为了探索大气污染与体力活动的交互效应,我们在空气污染物浓度高于周边地区的典型区域(济南市... 详细信息

本文介绍了《典型地区活动模式特色数据集》(Typical Regional Activity Patterns,TRAP),此数据集依托于“大气重污染成因与治理攻关项目”。为了探索大气污染与体力活动的交互效应,我们在空气污染物浓度高于周边地区的典型区域(济南市和保定市)收集了9,221名不同职业和生活方式居民连续3天的活动模式数据。TRAP数据集包括人口学指标(人口学、职业信息、个人习惯和居住条件)和体力活动模式数据(活动地点和活动强度)信息。此数据集提供了体力活动模式的暴露测量数据,数据使用者可以根据自己的特定目的将其与各种终点指标匹配。此数据集可为探究中国北方居民活动模式属性提供证据,为跨学科研究人员制定健康教育及健康促进策略和措施提供证据。

关键词：活动模式典型地区行为监测大气污染中国

Two‑parameter dynamical scaling analysis of single‑phase natural circulation in a simple rectangular loop based on dilation transformation

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Nuclear Science and Techniques 2022年第12期33卷 59-74页

作者： Jia‑Ning Xu Xiang‑Bin Li yu‑sheng liu Shuai Yang De‑Chen Zhang Qiao Wu School of Nuclear Science and Engineering North China Electric Power UniversityBeijing 102206China Beijing Key Laboratory of Passive Safety Technology for Nuclear Energy Beijing 102206China Nuclear and Radiation Safety Center MEEBeijing 100082China Department of Nuclear Engineering Oregon State UniversityCorvallisOR 97331USA

Scaling analysis is widely used to design scaled-down experimental facilities through which the prototype phenomena can be effectively *** a new method,dynamic system scaling(DSS)must be verified as a rational and applicable method.A DSS method based on dilation transformation was evaluated using single-phase natural circulation in a simple rectangular *** scaled-down cases were constructed based on two parameters—length ratio and dilation number—and the corresponding transient processes were simulated using the Relap5 computational *** results show that this DSS method can simulate the dynamic flow characteristics of scaled-down *** transient deviation of the temperature difference and mass flow rate of the scaled cases decrease with increases in the length ratio and dilation *** distortion of the transient temperature difference is smaller than that of the mass flow;however,the overall deviation is within a reasonable range.

关键词： Dynamical system scaling analysis Single-phase natural circulation Transient scaling deviation Dilation transformation

Mechanism of anomalous low friction phenomenon in deep block rock mass

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Mining Science and Technology 2009年第4期19卷 409-419页

作者： WU Hao FANG Qin ZHANG Ya-dong LU yu-sheng liu Jin-chun Engineering Institute of Engineering Corps PLA University of Science and Technology Nanjing Jiangsu 210007 China

Deep rock mass has the unique ＂self-stressed＂ block-hierarchical structure, anomalous low friction （ALF） was one of the typical nonlinear get-mechanical and dynamic responses in deep block rock mass, which occurred as the result of movements of large-scale get-blocks under the impact of external pulses （such as a deep confined explosion, earthquakes, rock bursts and etc.）. ALF phenomenon obtained its name to describe the curious phenomenon that the friction between interacting get-blocks qua- si-periodically disappears at some discrete points in time along the direction orthogonal to the direction of the external pulse. With the objective to confirm the existence of the ALF phenomenon and study the get-mechanical conditions for its occurrence experi- mentally and theoretically, laboratory tests on granite and cement mortar block models were carried out on a multipurpose testing system developed independently. The ALF phenomenon was realized under two loading schemes, i.e., blocks model and a working block were acted upon jointly by the action of a vertical impact and a horizontal static force, as well as the joint action of both ver- tical and horizontal impacts with differently delayed time intervals. We obtained the rules on variation of horizontal displacements of working blocks when the ALF phenomenon was realized in two tests. The discrete time delay intervals, corresponding to local maxima and minima of the horizontal displacement amplitudes and residual horizontal displacements of the working block, satis- fied canonical sequences multiplied by （√2）＇. Some of these time intervals satisfied the quantitative expression （√2）＇ ,alva. At last, 1D dynamic theoretical model was established, the analytical results agreed better with the test data, while the quantitative expression drawn from test data was not validated well in theoretical analyses.

关键词： deep block rock mass block-hierarchical structure optical fiber displacement meter anomalous low friction canonical sequence

Theoretical Studies on the Structures and Reactions of Halocarbenoids(Ⅰ)Structures and Stability of Chlorocarbenoid CHCl_2

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Chemical Research in Chinese Universities 1997年第3期13卷 256-261页

作者： Li LI Ji-hai, FENG sheng-yu,liu Wei (Chemical College,Shandong University,Jinan, 250100) SHANDONG UNIV CHEM COLLJINAN 250100PEOPLES R CHINA

The chlorocarbenoid , CHCl2Li , was studied by means of ab initio molecular or- bital theory. Three equilibrium structures and two isomerization transition states were located. The calculations showed that the three-membered ring structure is the most stable. The 'classical tetrahedral' structure is not the local minimum on the potential energy surface.

关键词： Chlorocarbenoid isomeric structure Ab initio molecular orbital calcu- lation

Nitrogen-doped carbon dots as photocatalysts for organic synthesis:Effect of nitrogen content on catalytic activity

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Nano Research 2024年第6期17卷 4825-4833页

作者： Kai-Kai Niu Chao-Qun Ma Rui-Zhi Dong Hui liu sheng-sheng yu Ling-Bao Xing School of Chemistry and Chemical Engineering Shandong University of TechnologyZibo 255000China

Regulating the doping of carbon dots(CDs)and the generation of reactive oxygen species(ROS)is essential to selectively control their application in photocatalytic organic *** study successfully synthesized five newly developed nitrogen-doped carbon dots(CDs 1-5)with varying nitrogen content,which have the ability to generate ROS when exposed to light radiation,specifically superoxide anion radicals(O_(2)•-)and singlet oxygen(^(1)O_(2)).The utilization of the aforementioned nitrogen-doped CDs as photocatalysts enables the realization of their potential in facilitating efficient photocatalytic organic ***,it was observed that the photocatalytic efficiency exhibited a gradual decrease when the nitrogen content in the CDs *** order to provide more evidence for this claim,we employed a set of five CDs in the context of photocatalytic dehalogenation ofα-bromoacetophenone,photocatalytic oxidative coupling reaction of amines to imines,photooxidation reaction of sulfides to sulfoxides,and cross-dehydrogenation coupling(CDC)reaction,in which it was further observed that there was a steady decrease in the yields of photocatalytic organic reactions as the nitrogen content in CDs ***,CDs 1 exhibited the best photocatalytic efficiency,thereby reinforcing the hypothesis that a higher nitrogen content corresponds to a decreased catalytic *** study not only investigates the impact of the nitrogen content on the catalytic performance of CDs,but also offers valuable insights for the future utilization of CDs for photocatalytic organic reactions in water.

关键词： carbon dots nitrogen-doped reactive oxygen species photocatalysis

Fractal model of spontaneous imbibition in low-permeability reservoirs coupled with heterogeneity of pore seepage channels and threshold pressure

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Petroleum Science 2024年第2期21卷 1002-1017页

作者： Ming-sheng Zuo Hao Chen Xi-Liang liu Hai-Peng liu Yi Wu Xin-yu Qi National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China College of Safety and Ocean Engineering China University of Petroleum(Beijing)Beijing102249China

Spontaneous imbibition(SI)is an important mechanism for enhancing oil recovery in low-permeability *** to the strong heterogeneity,and the non-Darcy flow,the construction of SI model for lowpermeability reservoirs is extremely ***,traditional SI models based on single or averaged capillary tortuosity ignore the influence of heterogeneity of pore seepage channels and the threshold pressure(TP)on ***,in this work,based on capillary model and fractal theory,a mathematical model of characterizing SI considering heterogeneity of pore seepage channels is *** this basis,the threshold pressure was introduced to determine the pore radius at which the wetted phase can displace *** proposed new SI model was verified by imbibition experimental *** study shows that for weakly heterogeneous cores with permeability of 0-1 m D,the traditional SI model can characterize the imbibition process relatively accurately,and the new imbibition model can increase the coefficient of determination by 1.05 ***,traditional model has serious deviations in predicting the imbibition recovery for cores with permeability of 10-50 m *** new SI model coupling with heterogeneity of pore seepage channels and threshold pressure effectively solves this problem,and the determination coefficient is increased from 0.344 to 0.922,which is increased by2.68 *** low-permeability reservoirs,the production of the oil in transitional pores(0.01-0.1μm)and mesopores(0.1-1μm)significantly affects the imbibition recovery,as the research shows that when the heterogeneity of pore seepage channels is ignored,the oil recovery in transitional pores and mesopores decreases by 7.54%and 4.26%,*** analysis shows that increasing interfacial tension,decreasing contact angle,oil-water viscosity ratio and threshold pressure will increase imbibition *** addition,there are critical values for the influence of these factors o

关键词： Spontaneous imbibition Low-permeability reservoir Fractal model Threshold pressure Capillary tube