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One-pot Two-Step Cycloaddition Reaction for Convenient Synthesis of Polycyclic Spirooxindole-fused [1,3]Oxazines

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Chinese Journal of Chemistry 2015年第9期33卷 1049-1056页

作者： jing Sun Hui gong Chaoguo Yan College of Chemistry & Chemical Engineering Yangzhou University Yangzhou Jiangsu 225002 China

The novel spirooxindoline fused [1,3]oxazines were efficiently synthesized from Diels-Alder reaction of N-arylmaleimides with 1,2-dihydro-2-oxospiro[3H-indole-3,2＇-[2H,9aH-pyrido[2,1-b][l,3]oxazines], which were generated in situ from three-component reactions of substituted pyridines and isatins with methyl propiolate, or di- methyl acetylenedicarboxylate. The stereochemistry of the products was clearly clarified by the analysis of 1H NMR data and single crystal structures of the obtained polycyclic compounds.

关键词： Diels-Alder reaction one-pot reaction diastereoselectivity spirooxindole oxazine maleimide

A curved surface solar radiation pressure force model for solar sail deformation

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Science China(Physics,Mechanics & Astronomy) 2012年第1期55卷 141-155页

作者： HE jing gong ShengPing LI JunFeng School of Aerospace Tsinghua University Beijing 100084 China

A precise force model is of vital importance for dynamics and control of solar sails. Among various factors, deviations from the ideal flat sails, elastic deformations of the sails, are really important as most solar sails are large flexible membranes. In this study, the deformed sails are modeled as smooth curved surfaces and a general total force model (GTFM) for the deformed sails is proposed. Various simplified versions of this GTFM are also derived for the symmetric deformation cases. Furthermore, differences between the ideal force models and our precise GTFM are investigated. The numerical results demonstrate that both the previous ideal reflected model and flat optical model are not as satisfactory as claimed before, by contrast with the actual dynamics from the GTFM. Thus this work paves the way for sail craft's precise navigation where exact forces are needed.

关键词： solar sail deformation curved surface solar radiation pressure force model

Packet scheduling for OFDMA based relay networks

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The Journal of China Universities of Posts and Telecommunications 2008年第4期15卷 40-45页

作者： HAN jing gong Ping WU Wei-ling School of Information Engineering Beijing University of Posts and Telecommunications Beijing 100876 China.

The combination of relay networks with orthogonal frequency division multiple access （OFDMA） has been proposed as a promising solution for the next generation wireless system. Considering different traffic classes and user quality of service （QoS）, three efficient scheduling algorithms are introduced in such networks. The round-robin （RR） algorithm in relay networks serves as a performance benchmark. Numerical results show that the proposed algorithms achieve significant improvement on system throughput and decrease system packet loss rate, compared with the RR and absence of relaying system （traditional network）. Furthermore, comparisons have been carried out among the three proposed algorithms.

关键词： OFDMA QoS relay scheduling

Parametric formulae for axial stiffness of CHS X-joints subjected to brace axial tension

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第2期12卷 121-130页

作者： Guo-zhi QIU jing-hai gong Jin-cheng ZHAO Department of Civil Engineering Shanghai Jiao Tong University Shanghai 200240 China

Recent research has shown that circular hollow section(CHS) joints may exhibit non-rigid behavior under axial load or bending. The non-rigid behavior significantly affects the mechanical performance of structures. This paper is concerned with the parametric formulae for predicting axial stiffness of CHS X-joints while braces are in tension. The factors influencing the axial stiffness of CHS X-joints under brace axial tension are investigated,including the joint geometric parameters,the axial force of the chord,and bending moments of braces in two directions,etc. Effects of various parameters on axial stiffness of CHS X-joints are examined by systematic single-parameter nonlinear analysis using shell finite element methods. The analysis is implemented in a finite element code,ANSYS. The observed trends form the basis of the formulae for calculating the joint axial stiffness under brace axial tension by multivariate regression technique. In order to simplify the formulae,two non-dimensional variables are introduced. The proposed formulae can be used to calculate the joint axial stiffness in the design of single-layer steel tubular structures.

关键词： Joint stiffness Brace tension Parametric analysis Stiffness formula

Characteristics of air flow driven by the free surface of the open channel

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Journal of Hydrodynamics 2022年第1期34卷 69-75页

作者： jing gong Jun Deng Wang-ru Wei Wei-wei Li State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu610065China

Spillway tunnels are a key structure in large-scale water conservancies. The high-head water inlet makes the water surface-velocity extremely high, and the air is driven by the free surface of the water to move downstream. This paper studies the air velocity distribution above the water surface through the model tests, under the assumption that the airflow is a turbulent boundary layer with a rough interface, and the influence of the water depth and the water velocity on the air velocity distribution is analyzed. It is shown that the air velocity is in an exponential distribution. As the measured position moves upward, the air velocity gradually decreases, and the gradient decreases. When the water depth increases, the air velocity increases but with the same distribution form. With the increase of the water surface-velocity, the air velocity at the same measuring point increases, the variation range near the water surface is large, the air boundary layer height increases slightly, and the index coefficient of the air velocity distribution function decreases. Through numerical fitting, the calculation formula of the air boundary layer thickness at different water surface velocities is obtained, along with the numerical value of the index coefficient.

关键词： Open channel air velocity distribution air boundary layer height index coefficient

Convergence analysis and application of the central force optimization algorithm

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Science China(Information Sciences) 2015年第5期58卷 208-210页

作者： MENG Chao gong jing LIU SanMin SUN ZhiXin Key Laboratory of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and TelecommunicationsMinistry of Education College of Mathematics & Physics Nanjing University of Posts and Telecommunications College of Computer and Information Anhui Polytechnic University

Dear editor,The Central Force Optimization(CFO)[1]is a new heuristic *** contrast with the stochastic algorithms such as Particle Swarm Optimization(PSO)[2],Ant Colony Optimization[3]and other such algorithms[4–6],CF... 详细信息

关键词： CFO Convergence analysis and application of the central force optimization algorithm

Progress in Processes and Catalysts for Dehydrogenation of Cyclohexanol to Cyclohexanone

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Transactions of Tianjin University 2023年第3期29卷 196-208页

作者： jing gong Shixin Hou Yue Wang Xinbin Ma Key Laboratory for Green Chemical Technology of Ministry of Education Collaborative Innovation Center of Chemical Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityBinhai New CityFuzhou 350207China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China

The dehydrogenation of cyclohexanol to cyclohexanone is a crucial industrial process in the production of caprolactam and adipic acid, both of which serve as important precursors in nylon textiles. This endothermic reaction is constrained by thermodynamic equilibrium and involves a complex reaction network, leading to a heightened focus on catalysts and process design. Copper-based catalysts have been extensively studied and exhibit exceptional low-temperature catalytic performance in cyclohexanol dehydrogenation, with some being commercially used in the industry. This paper specifically concentrates on research advancement concerning active species, reaction mechanisms, factors influencing product selectivity, and the deactivation behaviors of copper-based catalysts. Moreover, a brief introduction to the new processes that break thermodynamic equilibrium via reaction coupling and their corresponding catalysts is summarized here as well. These reviews may off er guidance and potential avenues for further investigations into catalysts and processes for cyclohexanol dehydrogenation.

关键词： Cyclohexanol Dehydrogenation Cyclohexanone Copper-based catalyst Reaction coupling processes

A MODEL FOR PREDICTING PHASE INVERSION IN OIL-WATER TWO-PHASE PIPE FLOW

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Journal of Hydrodynamics 2006年第3期18卷 310-314页

作者： gong jing LI Qing-ping YAO Hai-yuan YU Da Department of Oil and Gas Storage and Transportation China University of Petroleum （Beijing） Beijing 102249China China National Offshore Oil Cooperation Research Center Jing Xin Mansion Beijing 100027 China

Experiments of phase inversion characteristics for horizontal oil-water two-phase flow in a stainless steel pipe loop （25.7 mm inner diameter,52 m long） are conducted. A new viewpoint is brought forward about the process of phase inversion in oil-water two-phase pipe flow. Using the relations between the total free energies of the pre-inversion and post-inversion dispersions, a model for predicting phase inversion in oil-water two-phase pipe flow has been developed that considers the characteristics of pipe flow. This model is compared against other models with relevant data of phase inversion in oil-water two-phase pipe flow. Results indicate that this model is better than other models in terms of calculation precision and applicability. The model is useful for guiding the design for optimal performance and safety in the operation of oil-water two-phase pipe flow in oil fields.

关键词： two-phase flow oil water phase inversion,prediction model

Clinical characteristics and risk factors for liver injury in COVID-19 patients in Wuhan

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World Journal of Gastroenterology 2020年第31期26卷 4694-4702页

作者： Hu Zhang Yu-Sheng Liao jing gong jing Liu Heng Zhang Department of Gastroenterology the Central Hospital of WuhanTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430014Hubei ProvinceChina

BACKGROUND Coronavirus disease 2019(COVID-19)has become a worldwide *** investigated the clinical characteristics and risk factors for liver injury in COVID-19 patients in Wuhan by retrospectively analyzing the epidemiological,clinical,and laboratory data for 218 COVID-19 patients and identifying the risk factors for liver injury by multivariate *** To investigate the clinical characteristics and risk factors for liver injury in COVID-19 patients in *** The 218 patients included 94 males(43.1%),aged 22 to 94(50.1±18.4)*** aspartate aminotransferase(AST)and alanine aminotransferase(ALT)were present in 42(53.2%)and 36(45.6%)cases,respectively,and 79(36.2%)patients had abnormally elevated transaminase levels at *** with liver injury were older than those with normal liver function by a median of 12 years,with a significantly higher frequency of males(68.4%vs 28.8%,P5×***γ-glutamyl transpeptidase was present in 45(57.0%)patients,and 86.7%of these had aγ-glutamyl-transpeptidase level<135 U/L(3×ULN).Serum alkaline phosphatase levels were almost normal in all *** with severe liver injury had a significantly higher frequency of abnormal transaminases than non-severe patients,but only one case had very high levels of *** Multivariate analysis revealed that male sex,high D-dimer level,and high neutrophil percentage were linked to a higher risk of liver *** early stage of COVID-19 may be associated with mildly elevated aminotransferase levels in patients in *** sex and high

关键词： COVID-19 Liver injury Clinical characteristics Risk factors