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Electrooxidation of Hydroxypivalaldehyde in an Undivided Cell

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Chemical Research in Chinese Universities 2006年第5期22卷 626-630页

作者： yu Jian-guo CAO Xue-jing zhang heng-bin zhang yu-min LI Ke-chang College of Chemistry Jilin University Changchun 130021 P. R. China

The factors affecting the electrooxidation of hydroxypivalaldehyde（HPAL） in an undivided cell were studied by using cyclic voltammetry（CV）, linear scan voltammetry（ LSV）, and potentiostatic electrolysis. The electrocatalytic activity and stability of a PbO2 electrode in sulfuric acid, acetic acid, and phosphoric acid were studied. The selectivity and the current efficiency for producing hydroxypivalic acid were explored with different supporting electrolytes, concentrations of HPAL, and pH values. The results show that higher selectivity and current efficiency for producing hydroxypivalic acid can be achieved when sulfuric acid with a high concentration is used as the supporting electrolyte and the selectivity and the current efficiency can reach 80% and 60%. resvectively.

关键词： Hydroxypivalaldehyde Hydroxypivalic acid Electrooxidation Electrosynthesis

Dy_(2-x)Y_xTi_2O_7: phonon vibration and magnetization with dilution

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Rare Metals 2015年第2期34卷 81-88页

作者： Hui Liu You-Ming Zou Shi-Le zhang Ran-Ran zhang Chang-Jin zhang yu-heng zhang High Magnetic Field Laboratory Chinese Academy of Sciences and University of Science and Technology of China

In this paper, the dilution effects of non-magnetic Y ions on spin-ice compound Dy_2Ti_2O_7 by infrared and Raman spectra and magnetization measurements were investigated. An anomalous phonon softening with temperature decreasing is found in both the parent and diluted compounds, and Y doping can relax the softening of phonons except that of the IR mode near 233 cm^-1, indicating a strong phonon–phonon coupling in the spin-ice *** magnetization measurements reveal that the nonmagnetic impurities do not severely influence the spin-ice rules in the ground state when the level of dilution is not very high. However, a large amount of dilution enhance the disorder and break the spin-ice state because the collective spin-flip clusters are no longer available.

关键词： Dilution effect Spin ice Pyrochlore Frustration

First total synthesis of (±)-puyanin and (±)-4'-O-methylbonannione

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Chinese Chemical Letters 2010年第11期21卷 1267-1269页

作者： Jin Hui Yang yu heng zhang Hong Jun Li Shi Zhi Jiang yun Feng Li Key Laboratory of Energy Sources and Chemical Engineering of Ningxia Ningxia University Yinchuan 750021 China

A facile approach for the first total synthesis of two naturally occurring geranylated flavonoids,（±）-puyanin 1 and（±）-4＇-O- methylbonannione 2 has been obtained with total yield 27%and 21%,*** key steps were regioselective cyclization of geranylated trihydroxychalcone and regioselective geranylation of 2,4,6-trihydroxyacetophenone.

关键词： Puyanin 4'-O-Methylbonannione Flavanone Geranylated flavonoids Total synthesis

Research on the readout noise suppression method for digital correlated double sampling

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Research in Astronomy and Astrophysics 2021年第1期21卷 127-135页

作者： Wei Duan Qian Song Ming-Zhi Wei Zhao-Wang Zhao Wei Wang yu-heng zhang Zhi-Wei Feng National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesBeijing 100101China

As the areas of CCD detectors and CCD mosaics have become larger and larger,the number of readout channels in astronomical cameras has increased accordingly to keep the image readout time within an acceptable *** the large area cameras or the mosaic cameras,the analog Correlated Double Sampling(aCDS)circuit used in traditional astronomical cameras for suppressing readout noise is difficult to integrate into the camera controllers within the constraints of the space and energy ***,digital CDS(dCDS)technology has been developed to solve this problem,which also offers novel analysis and noise suppression *** this study,a mathematical model is presented to conveniently analyze the frequency characteristic of a dCDS circuit,which is then simulated by a numerical method for investigating the noise suppression capability with different sampling ***,using this model,the extreme point with lowest readout noise can be predicted for a certain dCDS model;and for a specific CCD readout frequency,readout noise can be suppressed by selecting the proper dCDS model.A testing system is then constructed for validating the efficiency of the proposed method.

关键词： instrumentation:detectors methods:analytical methods:numerical

First total synthesis of(±)-sepicanin A

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Chinese Chemical Letters 2012年第2期23卷 127-129页

作者： Jin Hui Yang Wen Qian Huang Jun Shan Luo Dong Dong Guo yu heng zhang Hong Jun Li State Key Laboratory Cultivation Base of Natural Gas Conversion Ningxia UniversityYinchuan 750021China Received 6 September 2011

A facile approach for the first total synthesis of naturally occurring geranylated flavanoids sepicanin A has been obtained with total yield 16%starting from 2,4,6-trihydroxyacetophenone after four *** key step was the protic acids（HCl or p-TsOH）-catalyzed benzopyrone formation in a protic polar solvent by deprotection and cycUzation of chalcone in one step.

关键词： Sepicanin A Flavanone Geranylated flavonoids Total synthesis

The Effect of PM2.5 on Economic Situation of Beijing and Solutions

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Journal of Zhouyi Research 2014年第6期 40-42页

作者： Guang-jing He Rong-ge Xiao yu-heng zhang School of Earth Sciences and Resources China University ofGeosciences Beijing China School of Land Science and Technology China University ofGeosciences Beijing China

The Effect of PM2.5 on Economic Situation of Beijing and Solutions

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International English Education Research 2015年第3期 40-42页

作者： Guang-jing He Rong-ge Xiao yu-heng zhang School of Earth Sciences and Resources China University ofGeosciences Beijing China School of Earth Sciences and Resources China University ofGeosciences Beijing. China School of Land Science and Technology China University ofGeosciences Beijing China

China＇s environmental problems have become increasingly serious, which have caused great attention of the relevant departments of the state. Through the survey, we found that in most of the cities in our country, the inhalable particulate matter PM10 is one of the main pollutants, especially in the capital of China -- Beijing, which is the arch-criminal cause of the air pollution. According to the quality control report released in Beijing City Environmental Protection Bureau, as can be learned, in recent years, Beijing＇s air quality goes from bad to worse, and in the overall atmospheric pollutants, the PM10 is up to above nine tenths. There are more reports saying that the air pollution levels in Beijing have been not suitable for the human habitation. With the increasing of the air pollution, the term PM2.5 is also more and more familiar to us. The air more intensified the pollution is, the greater the ratio of PM2.5 in PM10 is. In that case, it not only seriously affects the people＇s health, but also brings the huge economic losses. This paper is aimed to analyze the influence of PM2.5 on the economic situation of Beijing, and puts forward the concrete solutions.

关键词： Economic condition in Beijing PM2.5 influence solution

Research on the knee region of cosmic ray by using a novel type of electron-neutron detector array

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Frontiers of physics 2024年第4期19卷 13-24页

作者： Bing-Bing Li Xin-Hua Ma Shu-Wang Cui Hao-Kun Chen Tian-Lu Chen Danzengluobu Wei Gao Hai-Bing Hu Denis Kuleshov Kirill Kurinov Hu Liu Mao-yuan Liu Ye Liu Da-yu Peng Yao-Hui Qi Oleg Shchegolev yuri Stenkin Li-Qiao Yin heng-yu zhang Liang-Wei zhang College of Physics Hebei Normal UniversityShijiazhuang 050024China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China TIANFU Cosmic Ray Research Center Chengdu 610000China College of Science Tibet UniversityLhasa 850000China Key Laboratory of Comic Rays Ministry of EducationTibet UniversityLhasa 850000China Institute for Nuclear Research of the Russian Academy of Sciences Moscow 117312Russia School of Physical Science and Technology Southwest Jiaotong UniversityChengdu 610031China School of Management Science and Engineering Hebei University of Economics and BusinessShijiazhuang 050061China Moscow Institute of Physics and Technology Moscow 141700Russia

By accurately measuring composition and energy spectrum of cosmic ray,the origin problem of so called“knee”region(energy>one PeV)can be ***,up to the present,the results of the spectrum in the knee region obtained by several previous experiments have shown obvious differences,so they cannot give effective evidence for judging the theoretical models on the origin of the ***,the Large High Altitude Air Shower Observatory(LHAASO)has reported several major breakthroughs and important results in astro-particle physics *** on its advantages of wide-sky survey,high altitude location and large area detector arrays,the research content of LHAASO experiment mainly includes ultra high-energy gamma-ray astronomy,measurement of cosmic ray spectra in the knee region,searching for dark matter and new phenomena of particle physics at higher *** electron and thermal neutron detector(EN-Detector)is a new scintillator detector which applies thermal neutron detection technology to measure cosmic ray extensive air shower(EAS).This technology is an extension of *** EN-Detector Array(ENDA)can highly efficiently measure thermal neutrons generated by secondary hadrons so called“skeleton”of *** this paper,we perform the optimization of ENDA configuration,and obtain expectations on the ENDA results,including thermal neutron distribution,trigger efficiency and capability of cosmic ray composition *** obtained real data results are consistent with those by the Monte Carlo simulation.

关键词： cosmic ray EAS knee region LHAASO ENDA

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液力变矩器的闭锁控制

交通运输工程学报 2016年第5期16卷 66-73页

作者：惠记庄郭云欣郑恒玉张泽宇胡浩长安大学公路养护装备国家工程实验室陕西西安710064

以某型号工程车辆为研究对象,针对其工况特点,以闭锁控制原理为基础,计算并选择在不同油门开度下的常用闭锁点。以油门开度和涡轮转速为基础,以制动信号、档位信号和冷却水温度信号为辅助,设计了多参数闭锁控制策略,并建立了相应的闭锁... 详细信息

以某型号工程车辆为研究对象,针对其工况特点,以闭锁控制原理为基础,计算并选择在不同油门开度下的常用闭锁点。以油门开度和涡轮转速为基础,以制动信号、档位信号和冷却水温度信号为辅助,设计了多参数闭锁控制策略,并建立了相应的闭锁流程。运用MATLAB/Simulink软件建立了由闭锁控制模型、发动机模型、液力变矩器模型、液力变矩器输出模型、变速箱模型和外界阻力模型组成的整车模型,并对整车模型进行仿真。仿真结果表明:闭锁信号能对水温与档位信号做出正确响应,车辆在设定的闭锁点处实现闭锁;闭锁控制模型符合制定的闭锁控制策略,且其传动系统的输出模型符合实际工况,为车辆的闭锁控制提供了理论依据,也为车辆传动效率的提高与车辆节能减排提供了一种新方案。

关键词：车辆工程液力变矩器 Simulink 闭锁控制涡轮泵轮