检索结果-南通市图书馆

Effects of ethanol on the in situ synthesized Cu/SiO_2 catalyst:Texture,structure,and the catalytic performance in hydrogenation dimethyl oxalate to ethylene glycol

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2011年第3期22卷 362-365页

作者： Shu Rong Wang Ling Jun zhu Ying Ying zhu xiao Lan Ge Xin Bao Li State Key Laboratory of Clean Energy Utilization Zhejiang University Hangzhou 310027 China

The Cu/SiO_2 catalysts were in situ synthesized by the hydrolysis of tetraethyl orthosilicate（TEOS） in one phase solution using ethanol as co-solvent or TEOS/H_2O two phases solution,followed by the precipitation of copper on SiO_2 by ammonia evaporation. In the hydrogenation of dimethyl oxalate,the catalyst prepared by one phase hydrolysis exhibited higher activity and ethylene glycol（EG） selectivity at lower temperature than that of two phases due to its larger BET surface area and multimodal pore *** 488-503 K,the catalyst prepared in one phase solution with water/ethanol（W/E） volume ratio of 3：1 exhibited 90- 95%EG selectivity,while catalyst prepared by two phase hydrolysis reached 90%EG selectivity only at 498-503 K.

关键词： Ethanol Cu/SiO2 TEOS Hydrogenation Dimethyl oxalate Ethylene glycol

Selective parsing to enhance SIP performance

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2009年第5期16卷 50-55页

作者： CAO Yu-fei LIAO Jian-xin QI qi zhu xiao-min State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China EB Information Technology Ltd. Beijing 100190 China

The session initiation protocol （SIP） is used as the signaling protocol in the IP multimedia subsystem （IMS） and the signaling is becoming computing intensive comparing to the current telecommunication network. The SIP is a text-based protocol with characteristics of unordered and verbose headers, variable-size message, and case-insensitive keyword. It imposes challenges for an efficient message processing. The property of SIP elements being able to process SIP messages quickly is critical for the performance of IMS networks. This article investigates the performance of SIP message processed in SIP servers, mainly focusing on improving message parsing by introducing a method named selective parsing for SIP message （SP4SIP）. By modeling and analyzing a SIP server with a tandem Jackson network, it is concluded that parsing messages is the bottleneck of a SIP server performance, i.e., it is the most processing intensive activity in the system. To validate the approach, it has been implemented in a high-performance SIP server in the authors＇ lab. The results show that selective parsing for SIP message can indeed reduce processing time.

关键词： SP4SIP signaling performance SIP

A Curvature-Compensated Bandgap Reference with Improved PSRR

在线全文

学校读者我要写书评

暂无评论

A Curvature-Compensated Bandgap Reference with Improved PSRR

Electrolyte perspective on stabilizing LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)cathode for lithium-ion batteries

2005 6th International Conference on ASIC

作者： xiao Du Li Wei-min zhu xiao-fei Fu xiao-dong Beijing Microelectronics Technology Institute

ISBN: (纸本)0780392108

A curvature-compensated current mode bandgap reference with improved PSRR is *** circuit takes advantage of a simplified straightforward implementation of the curvature compensation method, the reference achieves a temperature coefficient of 7ppm/℃over the temperature range of-20℃to +80℃. And by using negative feedback to generate a regulated supply,the power supply rejection ration(PSRR) of the proposed circuit can be increased up to 90dB at *** circuit is designed using 0.8μm BiCMOS technology and silicon area is 1.07×0.92 mm.

关键词： Photonic band gap Voltage Power supplies Operational amplifiers Temperature distribution Feedback circuits Silicon Circuit stability Resistors Temperature dependence

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Rare Metals 2023年第2期42卷 387-398页

作者： xiao-Feng zhu Xiu Li Tian-Quan Liang Xin-Hua Liu Jian-Min Ma School of Resources Environment and MaterialsGuangxi UniversityNanning530004China School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu611731China School of Transportation Science and Engineering Beihang UniversityBeijing102206China

Nickel-rich LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)is regarded as the promising cathode for lithium-ion batteries(LIBs).However,the challenges such as safety issues and poor cycling performance have seriously hindered its commercial *** order to overcome these difficulties,there has been extensive research and development of electrolyte modifications for high-energy-density LIBs with Ni-rich ***,this review introduces the research progress based on solvent additives,salt type additives and other electrolytes for LIBs with NCM811cathode materials and discusses how they control the interface *** particular,some recommendations for further modification of enhancing electrolyte stability and improving NCM811 electrochemical properties are summarized and proposed,which put forward new design rules for the screening and customizing ideal electrolyte additives for high performance NCM811 cathode-based LIBs.

关键词： Nickel-rich LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811) Interface Electrolyte additives Cathode electrolyte interphase(CEI) Electrolyte

A numerical study of hydrodynamic characteristics and hydrological processes in the coastal wetlands during extreme events

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2023年第5期35卷 963-979页

作者： Ming-liang Zhang xiao-sen zhu Yu-jia Wang Heng-zhi Jiang Lei Cui College of Ocean Science and Environment Dalian Ocean UniversityDalian116023China Technology Innovation Center for Coastal Ecological Environment and Disaster Protection Liaoning ProvinceDalian116023China National Marine Environmental Monitoring Center Dalian116023China

Providing accurate predictions of extreme water levels through numerical simulation has become essential for disaster prevention and damage mitigation in coastal wetland *** study applies the FVCOM model to simulate storm surges caused by several typhoons in the Bohai Sea and the North Huanghai *** vegetation drag force caused by salt marsh plants is inserted into the FVCOM model for model improvement with vegetation effect by integrating RS and GIS technologies.A parametric typhoon model is coupled with background wind fields derived to acquire the spatio-temporal variations of wind and pressure fields in the computational *** simulation results reproduce the extreme storm surges induced by typhoon events very *** modeling results are compared by validating with literature results to examine the effect of vegetation on tidal waves in tidal mud ***,the coupled model is also applied to explore storm surge attenuation and land intrusion during Typhoon Winnie in the wetlands of the Liao River *** simulation results indicate that salt marsh plants can reduce the flow current with little impact on tide flooding/ebbing in vegetated ***,the results show that typhoon presence increases the inundation depth and extendes the flood time in the tidal wetlands of the study *** FVCOM model incorporating the method with vegetation drag force can provide new insights to understand the comprehensive impact of tidal wetland plants on hydrodynamic characteristics in the Bohai Sea and other waters,hence presents a more accurate quantification of the hydrological process of storm surge in the tidal wetlands.

关键词： FVCOM circulation model Parametric typhoon model coastal wetlands storm surge hydrological process

Dielectric and ferroelectric characteristics of Ba(Ti_(0.25)Zr_(0.25)Hf_(0.25)Sn_(0.25))O_(3)high-entropy ceramics

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 Materiomics 2023年第4期9卷 634-641页

作者： Rui Hu Mi Bu Hang Chen xiao Li zhu Xiang Ming Chen School of Materials Science and Engineering Zhejiang UniversityHangzhou310027China

Ba(Ti_(0.25)Zr_(0.25)Hf_(0.25)Sn_(0.25))O_(3)high-entropy ceramics were prepared by a standard solid state reaction process,and the dielectric and ferroelectric characteristics were investigated together with the *** X-ray diffraction(XRD)and energy dispersive spectroscopy(EDS)analysis demonstrated a single-phase perovskite structure in the present ceramics.A broad dielectric peak with strong frequency dispersion feature was determined,which indicated the typical relaxor nature originating from the nanoscale ferroelectric domain *** resulted from the structural distortion and chemical disorder due to high-entropy,where the long-range order of ferroelectric domains was *** homogeneous microstructure led to the reduced leakage current density and significantly improved dielectric strength,which was desired for the practical *** with the similar systems of Ba(Ti_(1-x)Zr_(x))O_(3)&Ba(Ti_(1-x)Sn_(x))O_(3),the present high-entropy ceramics indicated better relaxor ferroelectric characteristics.

关键词： High-entropy ceramic Microstructure Perovskite Relaxor ferroelectric

A weakly-solvated ether-based electrolyte for fast-charging graphite anode

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

Chinese Chemical Letters 2024年第8期35卷 526-532页

作者： xiao zhu Yanbing Mo Jiawei Chen Gaopan Liu Yonggang Wang xiaoli Dong Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Institute of New EnergyiChEM(Collaborative Innovation Center of Chemistry for Energy Materials)Fudan UniversityShanghai 200433China

Weakly-solvated electrolytes(WSEs)utilizing solvents with weak coordination ability offer advantages for low-potential graphite anode owing to their facile desolvation process and anions-derived inorganic-rich solid electrolyte interphase(SEI)***,these electrolytes face challenges in achieving a balance between the weak solvation affinity and high ionic conductivity,as well as between rigid inorganic-rich SEI and flexible SEI for long-term ***,we introduce 1,3-dioxolane(DOL)and lithium bis(trifluoromethanesulfonyl)-imide(LiTFSI)as functional additives into a WSE based on nonpolar cyclic ether(1,4-dioxane).The well-formulated WSE not only preserves the weakly solvated features and anion-dominated solvation sheath,but also utilizes DOL to contribute organic species for stabilizing the SEI *** from these merits,the optimized electrolyte enables graphite anode with excellent fast-charging performance(210 mAh/g at 5 C)and outstanding cycling stability(600 cycles with a capacity retention of 82.0%at room temperature and 400 cycles with a capacity retention of 80.4%at high temper-ature).Furthermore,the fabricated LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)||graphite full cells demonstrate stable operation for 140 cycles with high capacity retention of 80.3%.This work highlights the potential of tailoring solvation sheath and interphase properties in WSEs for advanced electrolyte design in graphite-based lithium-ion batteries.

关键词： Weakly-solvated solvent Bisalt ether-based electrolyte Graphite anode NCM||graphite battery Interfacial optimization

Corrosion resistance of biodegradable polymeric layer-by-layer coatings on magnesium alloy AZ31

在线全文

学校读者我要写书评

暂无评论

Frontiers of Materials Science 2016年第2期10卷 134-146页

作者： Lan-Yue CUI Rong-Chang ZENG xiao-xiao zhu Ting-Ting PANG Shuo-Qi LI Fen ZHANG College of Materials Science and Engineering Shandong University of Science and Technology Qingdao 266590 China State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology Shandong University of Science and Technology Qingdao 266590 China

Biocompatible polyelectrolyte multilayers （PEMs） and polysiloxane hybrid coatings were prepared to improve the corrosion resistance of biodegradable Mg alloy AZ31. The PEMs, which contained alternating poly（sodium 4-styrenesulfonate）（PSS） and poly（allylamine hydrochloride）（PAH）, were first self-assembled on the surface of the AZ31 alloy substrate via electrostatic interactions, designated as （PAH/PSS）s/AZ31. Then, the （PAH/PSS）5/AZ31 samples were dipped into a methyltrimethoxysilane （MTMS） solution to fabricate the PMTMS films, designated as PMTMS/（PAH/PSS）5/AZ31. The surface morphologies, microstructures and chemical compositions of the films were investigated by FE-SEM, FTIR, XRD and XPS. Potentiodynamic polarization, electro- chemical impedance spectroscopy and hydrogen evolution measurements demonstrated that the PMTMS/（PAH/PSS）s/AZ31 composite film significantly enhanced the corrosion resistance of the AZ31 alloy in Hank＇s balanced salt solution （HBSS）. The PAH and PSS films effectively improved the deposition of Ca-P compounds including Ca3（PO4）2 and hydroxyapatite （HA）. Moreover, the corrosion mechanism of the composite coating was discussed. These coatings could be an alternative candidate coating for biodegradable Mg alloys.

关键词： magnesium alloy polyelectrolyte polysiloxane corrosion layer-by-layer

Pyramiding of Pi46 and Pita to improve blast resistance and to evaluate the resistance effect of the two R genes

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2016年第10期15卷 2290-2298页

作者： xiao Wu-ming LUO Li-xin WANG Hui GUO Tao LIU Yong-zhu ZHOU Ji-yong zhu xiao-yuan YANG Qi-yun CHEN Zhi-qiang National Engineering Research Center of Plant Space Breeding South China Agricultural University Plant Protection Research Institute Guangdong Academy of Agricultural Sciences/Guangdong Provincial Key Laboratory of High Technology for Plant Protection

Utilization of R（resistance） genes to develop resistant cultivars is an effective strategy to combat against rice blast disease. In this study, R genes Pi46 and Pita in a resistant accession H4 were introgressed into an elite restorer line Hang-Hui-179（HH179） using the marker-assisted backcross breeding（MABB） procedure. As a result, three improved lines（e.g., R1791 carrying Pi46 alone, R1792 carrying Pita alone and R1793 carrying both Pi46 and Pita） were developed. The three improved lines had significant genetic similarities with the recurrent parent HH179. Thus, they and HH179 could be recognized as near isogenic lines（NILs）. The resistance spectrum of the three improved lines, which was tested at seedling stage, reached 91.1, 64.7 and 97.1%, respectively. This was markedly broader than that of HH179（23.5%）. Interestingly, R1793 showed resistance to panicle blast but neither R1791 nor R1792 exhibited resistance at two natural blast nurseries. The results implied that the stacking of Pi46 and Pita resulted in enhanced resistance, which was unachievable by either R gene alone. Further comparison indicated that the three improved lines were similar to HH179 in multiple agronomic traits; including plant height, tillers per plant, panicle length, spikelet fertility, and 1 000-grain weight. Thus, the three improved lines with different R genes can be used as new sources of resistance for developing variety. There is a complementary effect between the two R genes Pi46 and Pita.

关键词： rice blast resistance gene improvement marker-assisted selection