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Kinetics and mechanistic insights into the active sites of Au catalysts for selective propylene oxidation

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Nano Research 2023年第5期16卷 6220-6227页

作者： Qianhong Wang Zhihua Zhang Keng sang Wenyao Chen Gang Qian Jing Zhang Xinggui Zhou Xuezhi Duan State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China

Identification of the catalytically active sites emerges as the prerequisite for an atomic-level comprehensive understanding and further rational design of highly efficient catalysts.Here,we demonstrate a kinetics strategy to identify the active sites of Au catalyst for the disentanglement of geometric and electronic effects on the selective oxidation of propylene to acrolein.Both the Ti-containing titanium-silicalite-1(TS-1)and Ti-free silicalite-1(S-1)were employed as supports to immobilize Au catalysts,which were investigated by a combination of multiple characterization,kinetics analysis,crystal structure modelling.The Au(111)sites are identified as the main active site for acrolein formation,while their electronic effects are highly relevant to the presence or absence of Ti.Moreover,propylene epoxide(PO)formation mainly involves the co-participation of Au and Ti sites,the proximity between Au and Ti sites is found to have less influences on PO formation in a certain distance.In comparison,acrolein is very likely to generate over Au(111)sites via the hydrogen-assisted O_(2) activation to oxygenated species for its oxidizing propylene.The insights gained here could guide the design and preparation of Au catalysts for selective propylene oxidation.

关键词： propylene oxidation Au catalysts active site geometric and electronic effects Au-Ti proximity

新加坡研究型大学教师评价的关键特征与实践启示

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黑龙江高教研究 2023年第4期41卷 90-95页

作者：金晨 WANG Chee keng John 杭州师范大学浙江杭州311121 新加坡南洋理工大学新加坡637616

基于新加坡南洋理工大学国立教育学院的教师评价文本,分析其指标体系的关键特征。其在教学评价方面,创造性地引入教学学术理念;在研究评价方面,注重学术影响力的多渠道扩散;在服务评价方面,关注教师社会活动的边界拓展。基于此,我国研... 详细信息

基于新加坡南洋理工大学国立教育学院的教师评价文本,分析其指标体系的关键特征。其在教学评价方面,创造性地引入教学学术理念;在研究评价方面,注重学术影响力的多渠道扩散;在服务评价方面,关注教师社会活动的边界拓展。基于此,我国研究型高校的教师评价应将教学学术理念嵌入教师的教学评价、研究评价应重视学术影响力及其扩散表现、服务评价应遵循专业化和强辐射的原则。

关键词：研究型大学教师评价关键特征国际比较

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基于发展战略的柬埔寨发电规划研究

基于发展战略的柬埔寨发电规划研究

作者： keng CHANRASMEY 华北电力大学(北京)

学位级别：硕士

如今,柬埔寨的经济已经从低收入国家转变为中等收入国家。国家战略发展计划敦促该县经济在所有部门中快速增长。由于最近十年的增长,电力需求的增长非常迅速,这使得实际需求变得高于柬埔寨电力和能源部（MME）在2015年研究的柬埔寨电力... 详细信息

如今,柬埔寨的经济已经从低收入国家转变为中等收入国家。国家战略发展计划敦促该县经济在所有部门中快速增长。由于最近十年的增长,电力需求的增长非常迅速,这使得实际需求变得高于柬埔寨电力和能源部（MME）在2015年研究的柬埔寨电力发展总体计划中的预测需求。在这种情况下,柬埔寨政府迫切需要重建新的柬埔寨电力发展总体计划。这项研究的重点是解决和准备柬埔寨发电规划发展战略的方法和重点。该项目有两个主要部分需要分析和讨论。第一部分是长期电力需求预测,用于预测2020-2030年的能源需求（GWh）和高峰需求（MW）。由于电力需求的增长是相关的,并且还取决于经济和人口的增长,因此研究人员提出了多元线性回归模型,以GDP增长,每个部门和人口的电价为主要参数来预测电力需求,电力需求为分为工业,住宅和商业三个主要领域。选择工具“simple-e”进行仿真和分析,然后通过模型方程计算预测结果。第二部分是发电计划,研究该县一次能源的潜力。遵循政府降低电价,减少从邻国进口电力的政策,与MME国家发电计划中的现有计划讨论储备保证金以确保需求供应和电力平衡的建议,鼓励绿色和可再生能源发电能源,例如水能太阳能和风能发电厂以及液化天然气发电厂,应考虑并提出发电计划,以减少燃煤和HFO发电厂的发电量。结论将找出并提出一些建议,以了解弱点,挑战,面临的问题,人力资源以及用于制定2020-2030年柬埔寨发电计划的新技术。

关键词：电力需求预测发电计划储备裕度可再生能源

On the Curvature Conjecture of Hua Loo-keng

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Acta Mathematica Sinica,English Series 2012年第2期28卷 295-298页

作者： Qi keng LU Institute of Mathematics Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190 P.R.China

It is proved that both the holomorphic sectional and the bisectional curvatures of the conformal Bergman metric

关键词： Conformal metric curvature

“数字经济时代信息技术在应急管理中的理论与实践”专刊前言

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信息资源管理学报 2022年第3期12卷 4-6页

作者：萧文龙 keng Siau 于媛许荣华浙江工业大学管理学院杭州310023 香港城市大学信息系统系中国香港999077 武汉大学信息管理学院武汉430072

随着信息技术和信息系统的不断改进和发展,我国社会进入数字经济时代。数据分析、数据科学、人工智能和机器学习等新技术逐步被引入应急管理中,复杂的突发公共事件,比如突发公共卫生事件、自然灾害、火灾、大型事故灾害等事件的应急管... 详细信息

随着信息技术和信息系统的不断改进和发展,我国社会进入数字经济时代。数据分析、数据科学、人工智能和机器学习等新技术逐步被引入应急管理中,复杂的突发公共事件,比如突发公共卫生事件、自然灾害、火灾、大型事故灾害等事件的应急管理与决策支持服务水平不断提升。与此同时,应急信息管理过程中的信息收集、信息分析、信息共享和信息管理等流程的改进和发展也促进信息技术和信息系统的加速演进。

关键词：信息技术信息系统机器学习信息管理人工智能信息共享突发公共卫生事件理论与实践

Vitamin C exerts anti-cadmium induced fracture functions/targets:bioinformatic and biostructural findings

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Food Science and Human Wellness 2022年第5期11卷 1384-1391页

作者： Rong Li Songzuo Yu Xiao Liang Yu Li keng Po Lai Laboratory of Environmental Pollution and Integrative Omics Guangxi Key Laboratory of Tumor Immunology and Microenvironmental RegulationGuilin Medical UniversityGuilin 541004China Department of Neurosurgery Guigang City People's HospitalThe Eighth Affi liated Hospital of Guangxi Medical UniversityGuigang 537100China

Background:Epidemiological data indicate an association between cadmium exposure and risk of bone fracture;however,clinical treatment of cadmium-induced fracture is limited.Although vitamin C(VC)reportedly reduces cadmium-induced fracture,its pharmacological mechanism remains unexplored.Methods:Thus,we used a network pharmacology approach and molecular docking analysis to identify core targets,functional processes,and biological pathways involved in the anti-fracture action of VC.Results:Bioinformatics identified 17 intersection targets of VC and cadmium-induced fracture,Nine core targets were characterized,including tumor protein p53,epidermal growth factor receptor,proto-oncogene c,mitogen-activated protein kinase-1(MAPK1),MAPK3,signal transducer and activator of transcription-3,MAPK14,prostaglandin-endoperoxide synthase 2,and estrogen receptor alpha.Interestingly,findings of molecular docking analysis indicated that VC exerted effective binding capacity in cadmium-induced fracture.Furthermore,biological processes,cell components,molecular functions,and pharmacological pathways involved in the action of VC against cadmium-induced fracture were identified and visualized.Conclusions:Based on these findings,we conclude that VC exhibits its anti-cadmium-induced fracture effects by promoting osteoblastic regeneration and proliferation,and inhibiting inflammatory stress.The core targets may serve as biomarkers for diagnosing cadmium-induced fractures.

关键词： Cadmium Fracture Vitamin C Network pharmacology Mechanism

Perceptual quantization parameter selection for crime scene investigation tool images

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Frontiers of Computer Science 2023年第1期17卷 241-243页

作者： Yanchao GONG Zhao LI Zhuang WANG Kaifang YANG Ying LIU keng Pang LIM School of Communications and Information Engineering Xi’an University of Posts and TelecommunicationsXi’an 710121China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China School of Electronic and Information Engineering Chongqing Three Gorges UniversityChongqing 404000China School of Computer Science Shaanxi Normal UniversityXi’an 710119China XsecPro Pte.Ltd. Singapore 787820Singapore

1 Introduction Crime scene investigation(CSI)is critical for solving criminal cases and court trials.Currently,all CSI data must be kept as electronic files in specific systems according to relevant regulations.Electronic files,including reconstructed CSI images,provides great convenience for the public security and court to store,manage,display,and analyze CSI data more effectively.Image coding which pursues higher reconstructed quality of CSI images using lower coding rate plays a very important role in the above process.Compared with the previous image coding standards,high efficiency video coding(HEVC)still image coding technique significantly improves the image coding efficiency.The coding efficiency of HEVC is closely related to the selected quantization parameter(QP).

关键词： parameter image CSI

Laser sintering of Cu nanoparticles on PET polymer substrate for printed electronics at different wavelengths and process conditions

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Frontiers of Mechanical Engineering 2020年第2期15卷 303-318页

作者： Juan Carlos HERNANDEZ-CASTANEDA Boon keng LOK Hongyu ZHENG Singapore Institute of Manufacturing Technology Singapore 138634Singapore School of Mechanical Engineering Shandong University of TechnologyZibo 255049China

This study explores the feasibility of different laser systems to sinter screen-printed lines from nonconductive copper nanoparticles(Cu NPs)on polyethylene terephthalate polymer film.These materials are commonly used in manufacturing functional printed electronics for large-area applications.Here,optical and thermal characterization of the materials is conducted to identify suitable laser sources and process conditions.Direct diode(808 nm),Nd:YAG(1064 nm and second harmonic of 532 nm),and ytterbium fiber(1070 nm)lasers are explored.Optimal parameters for sintering the Cu NPs are identified for each laser system,which targets low resistivity and high processing speed.Finally,the quality of the sintered tracks is quantified,and the laser sintering mechanisms observed under different wavelengths are analyzed.Practical considerations are discussed to improve the laser sintering process of Cu NPs.

关键词： laser sintering copper nanoparticles printed electronics

Adaptive learning tracking control of robotic manipulators with uncertainties

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控制理论与应用（英文版） 2010年第2期8卷 160-165页

作者： keng Peng TEE Institute for Infocomm Research 1 Fusionopolis Way #21-01 Connexis Singapore 138632

An adaptive learning tracking control scheme is developed for robotic manipulators by a synthesis of adaptive control and learning control approaches. The proposed controller possesses both adaptive and learning properties and thereby is able to handle robotic systems with both time-varying periodic uncertainties and time invariant parameters. Theoretical proofs are established to show that proposed controllers ensure asymptotical tracking performance. The effectiveness of the proposed approaches is validated through extensive numerical simulation results.

关键词： Adaptive control Learning control Robotic dynamic systems Uncertainties