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Copper and amine free Sonogashira cross-coupling reaction catalyzed by efficient diphosphane-palladium catalyst

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Chinese Chemical Letters 2011年第10期22卷 1175-1178页

作者： Ting He Lei Lei Wu Xing Li Fu Hai Yan Fu Hua Chen Rui Xiang Li Key lab of Green Chemistry and Technology Ministry of Education College of Chemistry Sichuan University Chengdu 610064 China Guangxi Vocational ＆ technical Institute of Industry Nanning 530001 China

The commercially available diphosphane ligand MeO-BIPHEP was first investigated in the palladium-catalyzed Sonogashira reaction in the absence of copper and amine. The coupling of various aryl bromides and aryl chlori... 详细信息

关键词： MeO-BIPHEP Sonogashira reaction Diphosphane ligand Palladium complex

Finite Element Numerical Simulation and PIV Measurement of Flow Field inside Metering-in Spool Valve

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Chinese Journal of Mechanical Engineering 2009年第1期22卷 102-108页

作者： GAO Dianrong QIAO Haijun LU Xianghui Hebei Province Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Qinhuangdao 066004 China School of Vehicle and Energy Engineering Yanshan University Qinhuangdao 066004 China Hebei Vocational ＆ technical College of Building Materials Qinhuangdao 066004 China

The finite element method （FEM） and particle image velocimetry （PIV） technique are utilized to get the flow field along the inlet passage, the chamber, the metering port and the outlet passage of spool valve at three different valve openings. For FEM numerical simulation, the stream function ψ-vorticity ω forms of continuity and Navier-Stokes equations are employed and FEM is applied to discrete the equations. homemade simulation codes are executed to compute the values of stream function and vorticity at each node in the flow domain, then according to the correlation between stream function and velocity components, the velocity vectors of the whole field are calculated. For PIV experiment, pulse Nd： YAG laser is exploited to generate laser beam, cylindrical and spherical lenses are combined each other to produce 1.0 mm thickness laser sheet to illuminate the object plane, Polystyrene spherical particle with diameter of 30-50 μm is seeded in the fluid as a tracing particles, Kodak ES 1.0 CCD camera is employed to capture the images of interested, the images are processed with fast Fourier transform （FFT） cross-correlation algorithm and the processing results is displayed. Both results of numerical simulation and PIV experimental show that there are three main areas in the spool valve where vortex is formed. Numerical results also indicate that the valve opening have some effects on the flow structure of the valve. The investigation is helpful for qualitatively analyzing the energy loss, noise generating, steady state flow forces and even designing the geometry structure and flow passage.

关键词： flow field spool valve finite element method (FEM) particle image velocimetry (PIV)

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高氯酸杂环配合物金属盐的激光起爆(英文)

含能材料 2006年第6期14卷 401-405页

作者： Mikhail A.Ilyushin Igor V.Tselinsky Irina V.Bachurina Emil Ya.Seidov Anatolii S.Kozlov Dmitrii V.Korolev Alexei E.Olenin Saint-Petersburg State Institute of Technology (technical university) Russia

Several d-metal perchlorate complexes with 3-hydrazino-4-amino-5-R-1,2,4-triazoles as ligands （where R=H, CH3, SH） were investigated. It was shown that SH-group inhibited radical processes of thermal decomposition and burning of the complexes and also increased the thresholds of their Q-switch IR-laser initiation compared with the salts where as R=H, CH3-groups decreased the sensitivity of the metal complexes to laser initiation.

关键词：物理化学爆炸物脉冲激光技术

Comparison of Defuzzification Operators on Geographic Data of Ratio Scale

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Intelligent Information Management 2023年第5期15卷 373-389页

作者： Thomas Hatzichristos Dimitrios Ntzanis Department of Geography and Regional Planning School of Surveying & Geoinformatics Engineering National Technical University of Athens Athens Greece Department of Construction and Urban Planning Municipality of Agrinio Agrinio Greece

Fuzzy logic is a contemporary theory that has found numerous applications in Geographic Information Systems (GIS). Fuzzy logic allows for the representation of uncertainty and imprecision in spatial data, making it a valuable tool for dealing with the inherent ambiguity present in many geographic datasets. To solve a problem using a knowledge-based fuzzy system, the description and processing of the influencing factors or variables in fuzzy terms is required. The key components of a knowledge-based fuzzy system within the context of GIS are: Fuzzification, definition of the knowledge base, processing of the rules and finally defuzzification. Defuzzification is an important aspect of fuzzy logic and fuzzy set theory, as it helps convert fuzzy linguistic terms or fuzzy sets into crisp values that can be used in decision-making or analysis. Moreover, this might seem contradictory to the primary objective of fuzzy set theory, which is to model and work with uncertainty and imprecision. The aim of this paper is, first, to review defuzzification operators that are suitable for handling geographic data of ratio scale and second to compare these defuzzification operators by applying them to actual geographic data sets. For this reason, a case study based on pollution data of the municipality of Athens, Greece, was carried out to estimate pollution produced by SO2. The results of the application of defuzzification operators for the above geographic data set are compared and final conclusions are presented.

关键词： Fuzzy Logic Defuzzification GIS

Low conductance of nickel atomic junctions in hydrogen atmosphere

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Frontiers of physics 2017年第4期12卷 153-157页

作者： Shuaishuai Li Yi-Qun Xie Yibin Hu Department of Physics Shanghai Normal University Shanghai 200234 China National Laboratory for Infrared Physics Shanghai Institute of Technical Physics Chinese Academy of Sciences Shanghai 200083 China

The low conductance of nickel atomic junctions in tile hydrogen environment is studied using the nonequilibrium Green＇s function theory combined with first-principles calculations. The Ni junction bridged by a H2 molecule has a conductance of approximately 0.7 Go. This conductance is contributed by the anti-bonding state of the H2 molecule, which forms a bonding state with tile 3d orbitals of the nearby Ni atoms. In contrast, the Ni junction bridged by the two single H atoms has a conductance of approximately 1 Go, which is weakly spin-polarized. The spin-up channels were found to contribute mostly to the conductance at a small junction gap, while the spin-down channels play a dominant role at a larger junction gap.

关键词： atomic junction conductance nickel hydrogen

The Merits of Passive Compliant Joints in Legged Locomotion： Fast Learning, Superior Energy Efficiency and Versatile Sensing in a Quadruped Robot

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Journal of Bionic Engineering 2017年第1期14卷 1-14页

作者： Matej hoffmann Jakub Simanek iCub Facility Istituto Italiano di Tecnologia Genova 16123 Italy Artificial Intelligence Laboratory Department of lnformatics University of Zurich Zurich 8050 Switzerland Department of Measurement Faculty of Electrical Engineering Czech Technical University in Prague Prague 166 27 Czech Republic

A quadruped robot with four actuated hip joints and four passive highly compliant knee joints is used to demonstrate the potential of underactuation from two standpoints： learning locomotion and perception. First, we show that：（i） forward locomotion on flat ground can be learned rapidly （minutes of optimization time）; （ii） a simulation study reveals that a passive knee configuration leads to faster, more stable, and more efficient locomotion than a variant of the robot with active knees; （iii） the robot is capable of learning turning gaits as well. The merits of underactuation （reduced controller complexity, weight, and energy consumption） are thus preserved without compromising the versatility of behavior. Direct optimization on the reduced space of active joints leads to effective learning of model-free controllers. Second, we find passive compliant joints with po- tentiometers to effectively complement inertial sensors in a velocity estimation task and to outperform inertial and pressure sensors in a terrain detection task. Encoders on passive compliant joints thus constitute a cheap and compact but powerful sensing device that gauges joint position and force/torque, and -- if mounted more distally than the last actuated joints in a legged robot -- it delivers valuable information about the interaction of the robot with the ground.

关键词： legged robots underactuated robots compliant joints learning locomotion force and tactile sensing haptic terrain classification

High power supercontinuum generation by dual-color femtosecond laser pulses in fused silica

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Chinese Physics B 2022年第8期31卷 436-439页

作者： Saba Zafar 李东伟 Acner Camino 常峻巍郝作强 Shandong Provincial Engineering and technical Center of Light Manipulation&Shandong Provincial Key Laboratory of Optics and Photonic Device School of Physics and ElectronicsShandong Normal UniversityJinan 250358China Department of Physics Women University MardanMardan 23200Pakistan School of Science Changchun University of Science and TechnologyChangchun 130022China

High power supercontinuum(SC) is generated by focusing 800 nm and 400 nm femtosecond laser pulses in fused silica with a microlens array. It is found that the spectrum of the SC is getting broader compared with the case of a single laser pulse, and the spectral energy density between the two fundamental laser wavelengths is getting significantly higher by optimizing the phase matching angle of the BBO. It exceeds μJ/nm over 490 nm range which is from 380 nm to 870 nm,overcoming the disadvantage of relative lower power in the ranges far from the fundamental wavelength.

关键词： filamentation supercontinuum generation microlens array

Acid Separation, Catalytic Oxidation and Coagulation for ATC Waste Liquid Treatment

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Transactions of Tianjin university 2005年第2期11卷 97-100页

作者：丁晓玲贾春宁 Vocational and technical Education School Tianjin University Tianjin 300072 China Tianjin Environmental Protection Scientific Technology Information Center Tianjin 300191 China

It is difficult to treat 2-amino-thiazoline-4-carboxylic acid （ATC） waste liquid effectively at present for its characteristics of high chemical oxygen demand （COD）, high salinity and low biodegradability. In order to solve this problem, this paper presents several kinds of physical-chemical treatment unit techniques, including acid separation, catalytic oxidation and coagulation. First of all, acid separation was adopted to precipitate relevant organics at isoelectric point. When the temperature and pH value of acid separation were controlled at about 5 ℃ and 2.2 respectively, the COD removal rate could reach 27.600. Secondly, oxidation was used to break chemical constitution of refractory organics. The optimal reaction parameters of catalytic oxidation should be 20 ℃, pH adjusted to 5.0 and [Fe2+] 300 mg/L. Then with 500 H2O2 added and after one-hour reaction, the COD removal rate could achieve about 5200. Finally, coagulation was adopted to remove a portion of refractory organics, and 1500 polymeric molysite flocculant was the best for the coagulation, and the COD removal rate could reach about 1500. Therefore, the proposed feasible process of physical-chemical pretreatment for ATC waste liquid could have about 7000 COD removed in total.

关键词：酸分离法催化氧化反应凝结物废水处理工艺 2-氨基-二氢噻唑-4-羧基酸

Visible light catalyzed aromatization of 1,3,5-triaryl-2-pyrazolines by platinum(Ⅱ) polypyridyl complex under oxidant-free condition

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Science China Chemistry 2016年第2期59卷 175-179页

作者： Pan Ye Deng-Hui Wang Bin Chen Qing-Yuan Meng Chen-ho Tung Li-Zhu Wu School of Chemistry and Chemical Engineering Shandong University Jinan 250100 China Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and chemistry Chinese Academy of Sciences Beijing 100190 China

With visible light(λ=450 nm) irradiation of a catalytic amount of platinum(Ⅱ) terpyridyl complex, 1,3,5-triaryl-2-pyrazolines can be smoothly converted to their corresponding pyrazoles and hydrogen in quantitative y... 详细信息

关键词：铂(Ⅱ) 多吡啶配合物光催化氧化剂芳构化吡唑类化合物吡啶络合物可见光