检索结果-南通市图书馆

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

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

Bioinspired Ultrasensitive Flexible Strain Sensors for Real‑Time Wireless Detection of Liquid Leakage

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第3期17卷 310-327页

作者： Weilong Zhou yu Du Yingying Chen Congyuan zhang Xiaowei Ning heng Xie Ting Wu Jinlian Hu Jinping Qu Key Laboratory of Material Chemistry for Energy Conversion and Storage Ministry of EducationHubei Key Laboratory of Material Chemistry and Service Failure and Hubei Engineering Research Center for Biomaterials and Medical Protective MaterialsSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan 430074People’s Republic of China School of Materials Science and Engineering Wuhan Institute of TechnologyWuhan 430205People’s Republic of China Department of Biomedical Engineering City University of Hong KongHong KongSAR 999077People’s Republic of China

Liquid leakage of pipeline networks not only results in considerableresource wastage but also leads to environmental pollution and ecological *** response to this global issue, a bioinspired superhydrophobic thermoplastic polyurethane/carbon nanotubes/graphene nanosheets flexible strain sensor (TCGS) hasbeen developed using a combination of micro-extrusion compression molding andsurface modification for real-time wireless detection of liquid leakage. The TCGSutilizes the synergistic effects of Archimedean spiral crack arrays and micropores,which are inspired by the remarkable sensory capabilities of scorpions. This designachieves a sensitivity of 218.13 at a strain of 2%, which is an increase of 4300%. Additionally, it demonstrates exceptional durability bywithstanding over 5000 usage cycles. The robust superhydrophobicity of the TCGS significantly enhances sensitivity and stability indetecting small-scale liquid leakage, enabling precise monitoring of liquid leakage across a wide range of sizes, velocities, and compositionswhile issuing prompt alerts. This provides critical early warnings for both industrial pipelines and potential liquid leakage scenariosin everyday life. The development and utilization of bioinspired ultrasensitive flexible strain sensors offer an innovative and effectivesolution for the early wireless detection of liquid leakage.

关键词： Thermoplastic polyurethane Bioinspired Cracks Liquid leakage Flexible strain sensor

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Method for Estimating the State of Health of Lithium-ion Batteries Based on Differential Thermal Voltammetry and Sparrow Search Algorithm-Elman Neural Network

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy Engineering 2025年第1期122卷 203-220页

作者： yu zhang Daoyu zhang TiezhouWu School of Electrical and Electronic Engineering Hubei University of TechnologyWuhan430068China

Precisely estimating the state of health(SOH)of lithium-ion batteries is essential for battery management systems(BMS),as it plays a key role in ensuring the safe and reliable operation of battery ***,current SOH estimation methods often overlook the valuable temperature information that can effectively characterize battery aging during capacity ***,the Elman neural network,which is commonly employed for SOH estimation,exhibits several drawbacks,including slow training speed,a tendency to become trapped in local minima,and the initialization of weights and thresholds using pseudo-random numbers,leading to unstable model *** address these issues,this study addresses the challenge of precise and effective SOH detection by proposing a method for estimating the SOH of lithium-ion batteries based on differential thermal voltammetry(DTV)and an SSA-Elman neural ***,two health features(HFs)considering temperature factors and battery voltage are extracted fromthe differential thermal voltammetry curves and incremental capacity ***,the Sparrow Search Algorithm(SSA)is employed to optimize the initial weights and thresholds of the Elman neural network,forming the SSA-Elman neural network *** validate the performance,various neural networks,including the proposed SSA-Elman network,are tested using the Oxford battery aging *** experimental results demonstrate that the method developed in this study achieves superior accuracy and robustness,with a mean absolute error(MAE)of less than 0.9%and a rootmean square error(RMSE)below 1.4%.

关键词： Lithium-ion battery state of health differential thermal voltammetry Sparrow Search Algorithm