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Electrochemical Synthesis of Sulfonyl Fluorides with Triethylamine Hydrofluoride

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Chinese Journal of Chemistry 2022年第14期40卷 1687-1692页

作者： Lei Zhang Xu Cheng qi-Lin zhou State Key Laboratory and Institute of Elemento-Organic Chemistry College of ChemistryNankai UniversityTianjin 300071China Institute of Chemistry and Biomedical Sciences Jjiangsu Key Laboratory of Advanced Organic MaterialsNational Demon-stration Center for Experimental Chemistry EducationSchool of Chemistry and Chemical EngineeringNanjing UniversityNanjingJjiangsu 210023China

Hydrofluoride is an industry-preferred fluoride source,and finds extensively application to manufacture diverse fluoro *** Et3N-3HF complex is a liquid HF with improve *** this work,we report electrochemical synthesis of a series of sulfonyl fluoride with Et3N-3HF as fluoride *** sulfinic salt is a smell-less,non-volatile,and air-stable sulfur source in this *** the combination of Et3N-3HF and aryl/alkyl sulfinic salt,the sulfonyl fluorides are achieved without the use of external *** addition,we demonstrate further advantage in a tandem reaction involving Pd-catalyzed C—S cross-coupling and formation of S—F bond.A variety of functional groups including amino acids,heterocycles,halides are well tolerated.

关键词： Electrochemicstry Fluorides Click chemistry Sulfinic salt Dehydrogenation

Formation of multiple trimethylsilyl derivatives in the derivatization of 17α-ethinylestradiol with BSTFA or MSTFA followed by gas chromatography-mass spectrometry determination

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Journal of Environmental Sciences 2007年第7期19卷 879-884页

作者： zhou yi-qi WANG Zi-jian JIA Ning Sate Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China. College of Environment and Energy Engineering Beijing University of Technology Beijing 100022 China

N,O-bis（trimethylsily）trifluoroacetamide （BSTFA） and N-methyl-N（trimethylsily） trifluoroacetamide （MSTFA） are common derivatization reagents used in the GC-MS analysis of estrogen steroids such as estrone （El） and 17α-ethinylestradiol （EE2）. In this study, three trimethylsilyl （TMS） steroid derivatives, mono- and di-trimethylsilyl EE2 and mono-trimethylsilyl El, were observed during the derivatization of EE2 with BSTFA or MSTFA and/or GC separation. Factors influencing the production of multiple TMS derivatives and their relative abundance were examined. It was found that both methanol and bisphenol A competed with estrogenic esteroids when reacting with silylation reagents, and thus affected the formation of TMS derivatives and their relative abundance in the derivatization products. Methanol was found to be more reactive than bisphenol A with the BSTFA reagent. None of the three solvents tested in this study could prevent the generation of multiple TMS derivatives during the derivatization of EE2 with BSTFA, followed by GC analysis. A similar result was observed using MSTFA as the derivative reagent followed by GC analysis. Thus, the suitability of BSTFA or MSTFA as the derivatization reagent for the determination of E1 and EE2 by GC-MS, under the conditions reported here, is questionable. This problem can be solved by adding trimethylsilylimidaz （TMSI） in the BSTFA reagent as recommended, and the performance of the method has been proved in this study.

关键词： estrogens water sample GC/MS determination trimethylsilyl steroid derivatives

Finite Frequency Fuzzy H∞Control for Uncertain Active Suspension Systems With Sensor Failure

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IEEE/CAA Journal of Automatica Sinica 2018年第4期5卷 777-786页

作者： Zhenxing Zhang Hongyi Li Chengwei Wu qi zhou School of Mathematics and Physics Bohai UniversityJinzhou 121013China College of Engineering Bohai UniversityJinzhou 121013China School of Automation Guangdong University of TechnologyGuangzhou 510006China Department of Control Science and Engineering School of AstronauticsHarbin Institute of TechnologyHarbin 150001China College of Information Science and Technology Bohai UniversityJinzhou 121013China IEEE

This paper investigates the problem of finite frequency fuzzy H_∞ control for uncertain active vehicle suspension systems, in which sensor failure is taken into account. TakagiSugeno(T-S) fuzzy model is established for considered suspension systems. In order to describe the sensor fault effectively, a corresponding model is introduced. A vital performance index,H_∞ performance, is utilized to measure the drive comfort. In the framework of Kalman-yakubovich-Popov theory, the H_∞ norm from external perturbation to controlled output is optimized effectively in the frequency domain of 4 Hz-8 Hz to enhance ride comfort level. Meanwhile, three suspension constrained requirements, i.e., ride comfort level, manipulation stability,suspension deflection are also guaranteed. Furthermore, sufficient conditions are developed to design a fuzzy controller to guarantee the desired performance of active suspension systems. Finally, the proposed control scheme is applied to a quarter-vehicle active suspension, and simulation results are given to illustrate the effectiveness of the proposed approach.

关键词： Active vehicle suspension systems finite frequency control sensor failure Takagi-Sugeno fuzzy model

Environmental effects induced by excavation

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第1期9卷 50-57页

作者： yu-qi LI Jian zhou Kang-he XIE Department of Civil Engineering Shanghai University Shanghai 200072 China Department of Geotechnical Engineering Tongji University Shanghai 200092 China Institute of Geotechnical Engineering Zhejiang University Hangzhou 310027 China

Based on 3D Biot’s consolidation theory and nonlinear Duncan-Chang’s model, a 3D FEM (finite element method) program is developed considering the coupling of groundwater seepage and soil skeleton deformation during excavation. The comparison between the analysis result considering the variation of water head difference and that without considering it shows that the porewater pressure distribution of the former is distinctly different from that of the latter and that the foundation pit de- formations of the former are larger than those of the latter, so that the result without considering the variation of water head dif- ference is unreliable. The distribution rules of soil horizontal and vertical displacements around the pit and excess porewater pressure are analyzed in detail in time and space, which is very significant for guiding underground engineering construction and ensuring environment safety around the pit.

关键词： Environmental effect Excavation Deformation Excess porewater pressure

APPLICATION OF ELECTRON DIFFRACTION IN THE STRUCTURE CHARACTERIZATION OF POLyMER CRySTALS

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Chinese Journal of Polymer Science 2013年第6期31卷 841-841,842-852页

作者： Jiang Wu Hai-xin zhou qi Liu 闫寿科 Kunming University of Science and Technology State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology

The dependence of properties on the structure and morphology of semicrystalline polymers offers an effective way to tailor the properties of these materials through structure control. To this end, establishing the structure and property relationship is of great importance. For a right characterization of the crystal structure, several techniques can be used. Among these techniques, electron diffraction has its advantage for determining the crystal structure related to specific formation condition since it can combine with bright and dark fields observation of the sample. This feature article describes the application of electron diffraction in determining the crystal structure of semicrystalline polymers with elaborately selected examples. We focus on how the electron diffraction can be used to disclose the crystal structure, mutual orientation of different crystals, as well as the disorders included in the polymer crystals.

关键词： Electron diffraction Semicrystalline polymer Crystal structure Orientation Defect.

Partition and planning:A human-like motion decision for UAV in trap environment

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Science China(Technological Sciences) 2024年第4期67卷 1226-1237页

作者： CHEN JinTao zhou qi REN HongRu LI Hongyi School of Automation Guangdong University of TechnologyGuangzhou 510006China Provincial Key Laboratory of Intelligent Decision and Cooperative Control Guangdong University of Technology Guangzhou 510006Chi

This paper presents a human-like motion decision-making method for unmanned aerial vehicles(UAVs)navigating in trap *** proposed a space partitioning method based on sampling and consistency control to conduct a preliminary analysis of the indoor environment based on architectural *** method reduces the dimensionality of the path planning problem,thereby enhancing the ***,we designed a target-switching logic for the dynamic window *** improvement endows the UAV with the capability of both real-time obstacle avoidance and global navigation,enhancing the efficiency of the UAV in flying to task spots ***,by applying human-like methods of batch distance perception and obstacle perception to this scheme,we have further enhanced the robustness and efficiency of path ***,considering the scenario of high-rise fire rescue,we conducted simulation *** demonstrates that our scheme enhances the efficiency and robustness of path planning.

关键词： path planning indoor environment spacial partition high-rise fire rescue

Variable strength combinatorial testing of concurrent programs

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Frontiers of Computer Science 2016年第4期10卷 631-643页

作者： Xiaofang qi Jun HE Peng WANG Huayang zhou School of Computer Science and Engineering Southeast University Nanjing 211189 China Key Laboratory of Computer Network and Information Integration Ministry of Education Southeast University Nanjing 211189 China NARI Relays Electric Cooperation Nanjing 211102 China

Reachability testing is an important approach to testing concurrent programs. It generates and exercises syn- chronization sequences automatically and on-the-fly without saving any test history. Existing reach, ability testing can be classified into exhaustive and t-way testing. Exhaustive testing is impractical in many cases whilie t-way testing may decrease the capability of fault detection in some cases. In this paper, we present a variable strengda reachability testing strategy, which adopts the dynamic framework of reachability testing and uses a variable strength combinatorial strategy. Different parameter groups are provided with different covering strength. Variable strength testing covers no t-way combinations but the necessary combinations of parameters having mutual interactions in a concurrent program. It is more reasonable than t-way testing because uniform interactions between parameters do not often exist in concurrent systems. We propose a merging algorithm that implements the variable strength combinatorial testing strategy and conduct our experiment on several concurrent programs. The experimental results indicate that our variable strength reachability testing reaches a good tradeoff between the effectiveness and efficiency. It can keep the same capability of fault detection as exhaustive reachability testing while substantially reducing the number of synchronization sequences and decreasing the execution time in most cases.

关键词： software testing variable strength combinatorial testing concurrency testing reachability testing

Compositions and Transformations on Spherical Convex Sets

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Wuhan University Journal of Natural Sciences 2020年第4期25卷 277-285页

作者： zhou Xia GUO qi Department of Mathematics Suzhou University of Science and TechnologySuzhou 215009JiangsuChina

In this paper,we first study some compositions/transformations,such as the scalar-multiplication,spherical addition and canonical transformation,etc.,on the unit sphere of Euclidean spaces,and in turn on spherically convex sets in the unit *** we study valuations on the families of spherically convex *** particular,we show that the spherical projections defined recently by Ferreira et al are valuations in some cases.

关键词： spherical convexity radial projection projection to sphere valuation

New stem cell types for versatile applications

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National Science Review 2017年第4期4卷 528-530页

作者： Wei Li qi zhou State Key Laboratory of Stem Cell and Reproductive Biology Institute of ZoologyChinese Academy of Sciences University of Chinese Academy of Sciences

Haploids,being widespread in lower organisms like bacteria and fungi,can efficiently reveal the recessive traits due to the lack of second compensation allele,and thus have been widely used in biological research[1].However,haploidy only exists in highly specialized gametes in mammals,posing huge challenges for its application in mammalian

关键词： New stem cell types for versatile applications