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A ketone-functionalized aromatic saddle as a potential building block for negatively curved carbon nanobelts

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Chinese Chemical Letters 2019年第8期30卷 1506-1508页

作者： Kwan yin Cheung qian Miao Department of Chemistry The Chinese University of Hong Kong

A novel ketone-functionalized aromatic saddle consisting of 72 sp^2 carbon atoms is successfully synthesized and unambiguously identified with X-ray *** can,in principle,be used as a building block for synthesis of ne... 详细信息

关键词： Polycyclic arenes Synthesis Negatively curved carbon allotropes Carbon nanobelts Scholl reaction

Control structure comparison for three-product Petlyuk column

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Chinese Journal of Chemical Engineering 2018年第8期26卷 1621-1630页

作者： Shengkun Jia xing qian Xigang Yuan Sigurd Skogestad School of Chemical Engineering and Technology Chemical Engineering Research Center Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)State Key Laboratory of Chemical Engineering Tianjin University Department of Chemical Engineering Norwegian University of Science and Technology (NTNU)

The focus of this paper is to investigate different control structures(single-loop PI control) for a dividing wall(Petlyuk) column for separating ethanol, n-propanol and n-butanol. Four control structures are studied. All the results are simulations based on Aspen Plus. Control structure 1(CS1) is stabilizing control structure with only temperature controllers. CS2, CS3 and CS4, containing also composition controllers, are introduced to reduce the steady state composition deviations. CS2 adds a distillate composition controller(CCDB) on top of CS1. CS3 is much more complicated with three temperature-composition cascade controllers and in addition a selector to the reboiler duty to control the maximum controller output of light impurity composition control in side stream and bottom impurity control in the prefractionator. CS4 adds another high selector to control the light impurity in the sidestream. Surprisingly, when considering the dynamic and even steady state performance of the proposed control structures, CS1 proves to be the best control structure to handle feed disturbances inserted into the three-product Petlyuk column.

关键词： Distillation columns Automatic process control Computer-aided control system design Petlyuk columns

Separation of methyl linolenate and its analogues by functional mixture of imidazolium based ionic liquid-organic solvent-cuprous salt

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Chinese Journal of Chemical Engineering 2019年第4期27卷 811-817页

作者： Xianghong Lu Jiajian Zhu xing qian Jianbing Ji Zhejiang Provincial Key Laboratory of Biofuel College of Chemical EngineeringZhejiang University of Technology

Methyl linolenate was separated from its analogues by a new extraction system constructed by solvent,imidazolium based ionic liquids and cuprous salt. Firstly, the effect of ionic liquid on the dissolution of CuCl in acetonitrile, N,N-dimethylformamide(DMF), methanol and water was evaluated by visual observation.[C4Mim][Cl]can improve the dissolution of CuCl in acetonitrile. Then, for the new system as acetonitrile-ILs-CuCl, extraction equilibrium, distribution ratio and selectivity of methyl linolenate and its analogues were determined by gas chromatography analysis and the mass balance. The extraction time, IL structures and CuCl concentrations were investigated. Distribution ratio decreased slightly, but selectivity increased significantly with the addition of CuCl,[C4Mim][Cl] or [C4Vim][NTF2] into acetonitrile.[C4Vim][NTF2] had higher selectivity than [C4Mim][Cl].But the selectivity of the system combining CuCl with [C4Vim][NTF2] was much lower than with [C4 Mim][Cl].For the CuCl-[C4Mim][Cl]-acetonitrile, the extraction efficiency was better than CuCl-acetonitrile, increasing Cu^+ concentration effectively improved the separation selectivity when ratio of CuCl/[C4Mim][Cl] was less than 1. Compared with previous aqueous AgNO3 extractions, the method of using CuCl is a much cheaper and practical way to enrich unsaturated fatty acid.

关键词： Methyl linolenate Cuprous salt Ionic liquid Cosolvent Extraction

The Closed Orbits of a Class of Cubic Vector Fields in R^(3)

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Acta Mathematica Sinica,English Series 2020年第12期36卷 1429-1440页

作者： Hong Yan yin Da ZHOU xing An ZHANG School of Mathematics and Statistics Central China Normal UniversityWuhan 430079P.R.China School of Mathematics and Statistics South-Central University for NationalitiesWuhan 430074P.R.China School of Mathematical Sciences Xiamen UniversityXiamen 361005P.R.China

In this paper,we investigate the isolated closed orbits of two types of cubic vector fields in R^3 by using the idea of central projection transformation,which sets up a bridge connecting the vector field X(x)in R^3 with the planar vector *** have proved that the cubic vector field in R^3 can have two isolated closed orbits or one closed orbit on the invariant *** an application of this result,we have shown that a class of 3-dimensional cubic system has at least 10 isolated closed orbits located on 5 invariant cones,and another type of 3-dimensional cubic system has at least 26 isolated closed orbits located on 13 invariant cones or 26 invariant cones.

关键词： Closed orbit central projection transformation tangent vector field invariant cone

A review of inexact optimization modeling and its application to integrated water resources management

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Frontiers of Earth Science 2015年第1期9卷 51-64页

作者： Ran WANG yin LI qian TAN State Key Laboratory of Grassland Agro-ecosystems Institute of Arid Agroecology School of Life Sciences Lanzhou University Lanzhou 730000 China Research Institute of Highway Ministry of Transport Beijing 100088 China MOE Key Laboratory of Regional Energy and Environmental Systems Optimization Resources and Environmental Research Academy North China Electric Power University Beijing 102206 China Institute for Energy Environment and Sustainable Communities University of Regina Saskatchewan S4S 7H9 Canada

Water is crucial in supporting people＇s daily life and the continual quest for socio-economic development. It is also a fundamental resource for ecosystems. Due to the associated complexities and uncertainties, as well as intensive competition over limited water resources between human beings and ecosystems, decision makers are facing increased pressure to respond effectively to various water-related issues and conflicts from an integrated point of view. This quandary requires a focused effort to resolve a wide range of issues related to water resources, as well as the associated economic and environmental implications. Effective systems analysis approaches under uncertainty that successfully address interactions, complexities, uncertainties, and changing conditions associated with water resources, human activities, and ecological conditions are desired, which requires a systematic investigation of the previous studies in relevant areas. Systems analysis and optimization modeling for integrated water resources management under uncertainty is thus comprehensively reviewed in this paper. A number of related methodologies and applications related to stochastic, fuzzy, and interval mathematical optimization modeling are examined. Then, their applica- tions to integrated water resources management are presented. Perspectives of effective management schemes are investigated, demonstrating many demanding areas for enhanced research efforts, which include issues of data availability and reliability, concerns over uncertainty, necessity of post-modeling analysis, and the usefulness of the development of simulation techniques.

关键词： inexact optimization stochastic fuzzy sets,integrated water resources management uncertainty

Physics problems in bio or bioinspired additive manufacturing

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Bio-Design and Manufacturing 2023年第2期6卷 99-102页

作者： Jun yin Jin qian Yong Huang The State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversityHangzhou 310028China Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province School of Mechanical EngineeringZhejiang UniversityHangzhou 310028China Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province Department of Engineering MechanicsZhejiang UniversityHangzhou 310027China Department of Mechanical and Aerospace Engineering University of FloridaGainesvilleFL 32611USA

Additive manufacturing,also known as three-dimensional(3D)printing,has attracted increasing attention due to the innovations in materials science and manufacturing over recent decades[1].Recently,innovations in biocompatible materials and biology have enabled the extension of 3D printing techniques into bioadditive manufacturing,which focuses on the fabrication of 3D engineered native-like tissues/organs[2].Currently,bioadditive manufacturing technologies can be categorized into inkjet-based bioprinting,microextrusion-based bioprinting,digital light processing(DLP)bioprinting,electric field-assisted bioprinting,and fused deposition modeling(FDM),to name a few[3,4](Fig.1).Artificial tissues and organs with delicate structures,such as the heart[5]and liver[6],have been successfully fabricated using various bioadditive manufacturing techniques.

关键词： printing additive organs

Harmoniousness analysis of total amount control of water use

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Water Science and Engineering 2014年第1期7卷 49-59页

作者： qian-qi yin Guo-hua FANG College of Water Conservancy and Hydropower Engineering Hohai University

Based on the fundamental principles of total amount control of water use, the harmony theory was used in this study to develop a concept of the degree of harmony of total amount control of water use. Based on this concept, the harmoniousness of total amount control of water use was analyzed in terms of the supply and demand of water resources, water resources management, water use benefits, and water-saving level. An evaluation index system of the degree of harmony of total amount control of water use was established, and a method for calculation of the degree of harmony of total amount control of water use was developed based on the analytic hierarchy process （AHP） and fuzzy comprehensive analysis （FCA） methods. The new evaluation index system was applied to a certain area in Jiangsu Province, China. The degree of harmony of total amount control of water use over this area was calculated for different years. Results indicate that the evaluation index system and calculation method proposed in this study are feasible, and such a harmoniousness analysis can provide scientific references for the strict water resources management system that will be implemented in China in the near future.

关键词： total amount control of water usel degree of harmony evaluation index system quantification method analytic hierarchy process method fuzzy comprehensive analysis method

Characterization of 4-Aryl-5-ethoxycarbonyl-6-methyl-3,4-dihydro-pyrimidin-2(1H)-thiones by EI-TOF Mass Spectrometry

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Chemical Research in Chinese Universities 2006年第1期22卷 40-44页

作者： LI qian-rong XUE Song yin Hao Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemistry University of Science and Technology of China Hefei 230026 P. R. China

The electron impact （EI） time-of-flight mass spectra （TOFMS） of the title compounds （ thioxo-Biginelli compounds） were studied to establish their fragmentation pathways. With a TOF instrument of high resolution, the exact mass for each fragment was determined. These data were used to infer the molecular formulas and the ionic elemental compositions for all the compounds through interpretation by software. By further applying chemical intuition, majority of the fragmentation ions were fully assigned. All the compounds give strong signals（ average 76% ） for their molecular ions in the El spectra. Two kinds of characteristic fragmentation pathways from the molecular ion were observed. One is related to the loss of the ester group, forming a resonance stabilized ion with a moderate abundance（ average 40% ）. The other concerns the loss of the aromatic-ring radical, forming another resonance stabilized ion at m/z 199 with a high abundance（ average 79% ）, from which further important fragmentations including the formation of an ion at m/z 171 （average 24% ） by the loss of C2H2 （via the McLafferty rearrangement）, and an ion at m/z 153（ average 10% ） by the elimination of a water molecule preceed. In addition, ion [ M - Et ]^＋ with a high abundance（average 62% ） is a characteristic for the Biginelli compounds with an ethoxycarbonyl group. Differences and similarities among the fragmentations observed from the EI-TOFMS of oxo-Biginelli compounds are discussed.

关键词： Beginelli compound 3,4-Dihydropyrimidinthione Time-of-flight mass spectrometry Electron impact

Classification of yearly extreme precipitation events and associated flood risk in the Yangtze-Huaihe River Valley

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Science China Earth Sciences 2018年第9期61卷 1341-1356页

作者： Zhiqing XIE yin DU Yan ZENG qian MIAO Jiangsu Climate Center Nanfing 210009 China Key Laboratory of Meteorological Disaster Ministry of Education International Joint Laboratory on Climate and Environment Change Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Climate Dynamics Research Center Nanjing University of Information Science and Technology Nanjing 210044 China Huaihe Basin Meteorological Center Hefei 230031 China

Fifty cases of regional yearly extreme precipitation events （RYEPEs） were identified over the Yangtze-Huaihe River Valley （YHRV） during 1979-2016 applying the statistical percentile method. There were five types of RYEPEs, namely Yangtze Meiyu （YM-RYEPE）, Huaihe Meiyu （HM-RYEPE）, southwest-northeast-oriented Meiyu （SWNE-RYEPE） and typhoon I and II （TC-RYEPE） types of RYEPEs. Potential vorticity diagnosis showed that propagation trajectories of the RYEPEs along the Western Pacific Subtropical High and its steering flow were concentrated over the southern YHRV. As a result, the strongest and most frequently RYEPEs events, about 16-21 cases with average rainfall above 100 mm, occurred in the southern YHRV, particularly in the Nanjing metropolitan area. There have been 14 cases of flood-inducing RYEPEs since 1979, with the submerged area exceeding 120 km2 as simulated by the FloodArea hydraulic model, comprising six HM-RYEPEs, five YM- RYEPEs, two TC-RYEPEs, and one SWNE-RYEPE. The combination of evolving RYEPEs and rapid expansion of urban agglomeration is most likely to change the flood risk distribution over the Nanjing metropolitan area in the future. In the RCP6.0 （RCPS.5） scenario, the built-up area increases at a rate of about 10.41 km2 （10 yr）-t（24.67 km2 （10 yr）-1） from 2010 to 2100, and the area of high flood risk correspondingly increases from 3.86 km2（3.86 km2） to 9.00 kin2（13.51 km2）. Areas of high flood risk are mainly located at Chishan Lake in Jurong, Lukou International Airport in Nanjing, Dongshan in Jiangning District, Lishui District and other low-lying areas. The accurate simulation of flood scenarios can help reduce losses due to torrential flooding and improve early warnings, evacuation planning and risk analysis. More attention should be paid to the projected high flood risk because of the concentrated population, industrial zones and social wealth throughout the Nanjing metropolitan area.

关键词： Yangtze-Huaihe River Valley Extreme precipitation events FloodArea model Flood risk