检索结果-南通市图书馆

Improved direct power control of a grid-connected voltage source converter during network unbalance

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第10期11卷 817-823页

作者： peng ZHOU wei zhang Yi-kang HE Rong ZENG School of Electrical Engineering Zhejiang University Hangzhou 310027 China

This paper deals with an improved direct power control(DPC) strategy for the pulse width modulation(PWM) voltage source converter(VSC) under unbalanced grid voltage *** order to provide enhanced control performance for the VSC,the resonant controllers tuned at the double grid frequency are applied in the DPC design to eliminate the power pulsations and dc link voltage ripples produced by the transient unbalanced grid *** this way,the output power and dc link voltage of the VSC can be directly regulated without positive and negative sequential *** a result,and as has been verified by experiment,the proposed method can provide fast dynamic response with easy implementation.

关键词： Voltage source converter Direct oower control Unbalance Resonant controller

First-principles calculations and experimental studies of Sn-Zn alloys as negative electrode materials for lithium-ion batteries

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2011年第2期30卷 160-165页

作者： RU Qiang peng wei zhang Zhiwen HU Shejun LI Yanling Laboratory of Quantum Information Technology School of Physics and Telecommunication Engineering South China Normal University Guangzhou 510006 China

The physical characters and electrochemical properties of various phases in a Sn-Zn electrode, such as formation energy, plateau potential, specific capacity, as well as volume expansion, were calculated by the first-principles plane-wave pseudo-potential method based on the den- sity functional theory. Sn-Zn films were also deposited on copper foils by an electroless plating technique. The actual composition and chemical characters were explored by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, plasma atomic emission spectrometry （ICP）, and constant current charge/discharge measurements （CC）. The results show that separation phases with tin and zinc including a small quantity of Cu6Sn5 phase were obtained, the initial lithium insertion capacity of the Sn-Zn film was 661 mAh/g, and obvious potential pla- teaus of about 0.4 V and 0.7 V were displayed, which is in accordance with the results of theoretical calculations. The capacity of the Sn-Zn film decreased seriously with the increase of cycle number.

关键词： lithium batteries electrochemical electrodes tin alloys first-principles calculations

Wave-front correction of high-intensity fs laser beams by using closed-loop adaptive optics system

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2005年第1期48卷 122-128页

作者： WANG Zhaohua JIN Zhan ZHENG Jiaan WANG peng wei Zhiyi zhang Jie Laboratory of Optical Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China Laboratory of Optical Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China Laboratory of Optical Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China Laboratory of Optical Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China Laboratory of Optical Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China Laboratory of Optical Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China

We developed an adaptive optics system to correct the wave-front distortion of an intense fs laser beam from our multi-TW laser system, Jiguang II. In this paper, the instruments of the adaptive optical system are described and the experimental results of the closed-loop wave-front correction are presented. A distorted laser wave-front of 20 wavelengths of P-V values was corrected to 0.15 wavelength of P-V values. The beam quality of the laser system varies from 3.5 diffraction limit to 1.5 diffraction limit.

关键词： Shack-Hartmann wave-front sensor, adaptive optics system, femtosecond laser, diffraction limit.

New cytotoxic C-3 dehydrated bufadienolides from the venom of Bufo bufo gargarizans

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2014年第7期25卷 1104-1106页

作者： Hai-Yan Tian peng-wei zhang Jun-Shan Liu Dong-Mei zhang Xiao-Qi zhang Ren-Wang Jiang Wen-Cai Ye Institute of Traditional Chinese Medicine and Natural Products College of PharmacyJi’nan University School of Traditional Chinese Medicine Southern Medical University Southern Medical University JNU-HKUST Joint Laboratory for Neuroscience & Innovative Drug Research Ji’nan University

Three new C-3 dehydrated bufadienolides were isolated from the venom of Bufo bufo gargarizans. Their structures were elucidated as 5β,12β-12,14-dihydroxy-11-oxobufa-3,20,22-trienolide （1）, 5β,12β- 12,14-dihydroxy-11 -oxobufa-2,20,22-trienolide （2）, and 5β,12β-12,14-dihydroxy-11 -oxobufa-2,20,22- trienolide （3） on the basis of extensive spectroscopic analysis, especially 1D NMR and 2D NMR data. In addition, all three compounds were tested for their cytotoxic activities against A549 and HepG2 cancer cell lines. Compounds 2 and 3 showed significant cytotoxicities with IC50 values less than 10 μmol/L on both cancer cells.

关键词： Toad venom Bufo bufo gargarizans 3-Dehydrated bufadienolide Cytotoxicity

Pollution source identification methods and remediation technologies of groundwater: A review

在线全文

学校读者我要写书评

暂无评论

China Geology 2024年第1期7卷 125-137页

作者： Ya-ci Liu Yu-hong Fei Ya-song Li Xi-lin Bao peng-wei zhang Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes Institute of Hydrogeology and Environmental GeologyChinese Academy of Geological SciencesXiamen 361000China Key Laboratory of Water and Soil Resources Conservation and Restoration in the Middle and Lower Reaches of Yellow River Basin MNRZhengzhou 450016China

Groundwater is an important source of drinking *** pollution severely endangers drinking water safety and sustainable social *** the case of groundwater pollution,the top priority is to identify pollution sources,and accurate information on pollution sources is the premise of efficient ***,an appropriate pollution remediation scheme should be developed according to information on pollution sources,site conditions,and economic *** methods for identifying pollution sources mainly include geophysical exploration,geochemistry,isotopic tracing,and numerical *** these identification methods,only the numerical modeling can recognize various information on pollution sources,while other methods can only identify a certain aspect of pollution *** remediation technologies of groundwater can be divided into in-situ and ex-situ remediation technologies according to the remediation *** in-situ remediation technologies enjoy low costs and a wide remediation range,but their remediation performance is prone to be affected by environmental conditions and cause secondary *** ex-situ remediation technologies boast high remediation efficiency,high processing capacity,and high treatment concentration but suffer high *** methods for pollution source identification and remediation technologies are applicable to different *** achieve the expected identification and remediation results,it is feasible to combine several methods and technologies according to the actual hydrogeological conditions of contaminated sites and the nature of ***,detailed knowledge about the hydrogeological conditions and stratigraphic structure of the contaminated site is the basis of all work regardless of the adopted identification methods or remediation technologies.

关键词： Groundwater pollution Identification of pollution sources Geophysical exploration identification Geochemistry identification Isotopic tracing Numerical modeling Remediation technology Hydrogeological conditions Hydrogeological survey engineering

Electrodeposition and Characterization of Polyaniline Film

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2012年第1期28卷 133-136页

作者： WANG Hong-zhi, zhang peng, zhang wei-guo and YAO Su-wei Shanshan Research Office of Surface Technology, College of Chemical Engineering, Tianjin University, Tianjin 300072, P. R. China Tianjin Univ Shanshan Res Off Surface Technol Coll Chem Engn Tianjin 300072 Peoples R China

Abstract Polyaniline film was prepared by electrochemical method in an acidic solution of aniline. The micromor- phology of the polyaniline film was transformed to three-dimensional network structure instead of little particles while the deposition time was extended. The peak wavelength of the photoluminescence spectrum was 491 nm. The luminous intensity increased with the extension of deposition time, and so did the electrochemical activity.

关键词： Polyaniline Electrodeposition Photoluminescence Electrochemical activity

Cloning and Expression Analysis of a Mitogen-Activated Protein Kinase Gene OsMPK14 in Rice

在线全文

学校读者我要写书评

暂无评论

Rice science 2010年第4期17卷 269-275页

作者： LIANG wei-hong BI Jia-jia peng wei-feng zhang Fan SHI Hong-hao LI Li College of Life Science Henan Normal University Xinxiang 453007 China

Mitogen activated-protein kinases （MAPKs） are important components in signal transduction pathways responding to various biotic and abiotic stresses. An MAPK gene, OsMPK14 （GenBank Accession No. GQ265780） from rice （Oryza sativa L.）, was cloned by RT-PCR. The full-length cDNA of OsMPK14 consists of 1660 bp in size, containing an open reading frame of 1629 bp, which encodes a 542-amino-acid polypeptide and has a typical protein kinase domain and a phosphorylation activation motif TDY. Sequence alignment and analysis revealed that OsMPK14 was located on rice chromosome 5, and composed of nine exons and eight introns in the coding region. Semi-quantitative RT-PCR was performed to detect the expression patterns of OsMPK14 in rice shoots and roots under darkness, drought, high salinity, low temperature and abscisic acid treatments. The OsMPK14 mRNA was induced by abscisic acid, low temperature and high salinity, but weakly inhibited by drought. In addition, the expression of OsMPK14 was up-regulated in roots, but down-regulated in shoots by light. The results indicate that OsMPK14 could be implicated in diverse rice stimuli-responsive signaling cascades, and its expression might be regulated by multiple factors.

关键词： rice mitogen-activated protein kinase gene gene clone abiotic stress expression analysis

Ilizarov technique for treating elbow stiffness caused by myositis ossificans:A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第17期12卷 3144-3150页

作者： Ming-Wang Zhou peng-wei zhang An-Le zhang Chang-Hao wei Yu-De Xu wei Chen Zhi-Bin Fu Department of Orthopedics Medicine Gansu Province Hospital of Chinese MedicineLanzhou 730050Gansu ProvinceChina Gansu University of Chinese Medicine Clinical College of Traditional Chinese MedicineLanzhou 730000Gansu ProvinceChina

BACKGROUND Myositis ossificans(MO)is a rare disease involving the formation of bone outside the musculoskeletal *** surgical intervention is the main treatment approach,preventing recurrence and standardized rehabilitation are also ***,we present a surgical strategy to prevent the recurrence of *** SUMMARY A 28-year-old female patient was admitted for the first time for a comminuted fracture of the left ***,incorrect postoperative rehabilitation resulted in the development of elbow joint stiffness with ectopic ossification,causing a loss of normal range of *** patient was diagnosed with MO based on physical examination,X-ray findings,and clinical *** devised a surgical strategy to remove MO,followed by fixation with an Ilizarov frame,and implemented a scientifically reasonable rehabilitation *** surgery lasted for 3 h with an estimated blood loss of 45 mL.A drainage tube was placed after surgery,and fluid was aspirated through ultrasound-guided *** patient experienced a significant reduction in joint stiffness after *** the final follow-up at 9 mouths,there was evident improvement in the range of motion of the elbow joint,and no other symptoms were *** The Ilizarov frame is an advantageous surgical technique for facilitating rehabilitation after MO *** offers benefits such as passive recovery,individualized treatment,and prompt recovery.

关键词： Myositis ossificans Ilizarov frame Rehabilitation strategy Stiffness Case report

Deciphering the role of ultra-low-loaded rhodium in NiFe-MIL-53 for superior oxygen evolution reaction

维普期刊数据库评论

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 Energy Chemistry 2025年第1期100卷 77-86页

作者： Jinzhi Jia Jinhua zhang Kailu Guo Lanyue zhang Gening Du Hao You Junfeng Huang Mudong Tu Hua Li Yong peng wei Dou Cailing Xu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical Engineering School of Materials and Energy Lanzhou University College of Chemistry and Chemical Engineering Luoyang Normal University

Designing highly active and stable electrocatalysts of oxygen evolution reaction （OER） is one of the crucial *** this study,a novel OER electrocatalyst,NiFe-MIL-53 modified with ultra-low rhodium（Rh@NiFe-MIL-53）,is successfully prepared via the hydrothermal ***-situ Raman spectroscopy and electrochemical impedance spectroscopy reveal that the doped Rh accelerates the phase transformation of NiFe-MIL-53 and the in-situ formed Rh@NiFeOOH is the actual active *** importantly,the enhanced reversibility of electrochemical reconstruction between NiFeOOH and NiFe（OH）2after doping Rh is beneficial for improving the electrochemical stability of the catalyst.X-ray photoelectron spectroscopy spectra show the strong electronic interaction between single-atom Rh and Ni/Fe in Rh@***,theoretical calculations confirm that the integration of single-atom Rh into the NiFeOOH successfully reduces the band gap,regulates the d-band center （εd）,accelerates the charge transfer,and optimizes the adsorption behavior of oxygen-containing intermediates,thereby lowering the energy barrier of rate-determining ***,the optimized Rh@NiFe-MIL-53 exhibits excellent OER activity （240 mV） with a small Tafel slope of 48.2 mV dec-1and long-term durability (over1270 h at 10 m A cm-2and 110 h at 200 mA cm-2).This work presents a new perspective on designing highly efficient OER electrocatalysts.

关键词： NiFe-MIL-53 Rh Electrochemical reconstruction Catalytic mechanism Oxygen evolution reaction