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Chinese Chemical Letters 2020年第11期31卷 2933-2936页

作者： Yuyu Wang Houna Duan Hongyuan Shi Shiwei Zhang Yufang Xu Weiping Zhu Xuhong qian State Key Laboratory of Bioreactor Engineering Shanghai Key Laboratory of Chemical BiologySchool of PharmacyEast China University of Science and TechnologyShanghai 200237China Department of Radiology Jiangsu Province HospitalFirst Affiliated Hospital of Nanjing Medical UniversityNanjing 210029China

A highly sensitive fluorescent sensor ZnDN was designed,synthesized and used for tracking intracellular zinc ions in various living cells and direct imaging of prostatic tissue in *** was prepared from the heterocyclic-fused naphthalimide fluorophore,and the zinc receptor,N,N-bis(2-pyridylmethyl)ethylenediamine(BPEN).Upon addition of Zn2+to the solutions of ZnDN,a remarkable fluorescence enhancement was observed,which could be attributed to the photo-induced electron transfer(PET)*** ZnDN exhibited high sensitivity toward Zn2+in phosphate buffer solution,with a limit of detection of 4.0 x 10-9 mol/L,it was further applied for the imaging of exogenous and endogenous Zn21 in different living *** cells imaging experiments suggested that ZnDN could image the changes of intracellular free zinc ions,and could be used for two-photon ***,flow cytometry suggested that ZnDN could distinguish cancerous prostate cells from normal *** experiments indicated that ZnDN had the potential in imaging prostate tissue in vivo.

关键词： Fluorescent probe Zinc ion Prostate cells Naphthalimide In vivo imaging

Effect of Short Chain Alcohols upon Viscosity of TTAB Solution

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Chinese Journal of Chemical Physics 2008年第2期21卷 169-173页

作者： Yun-fei Yan Hua-zhen Li Hai-yang Yang Jia-sheng qian Ping-ping Zhu Ping-sheng He Department of Polymer science and Engineering University of Science and Technology of China Hefei 230026 China

The effect of ethanol （C2H5OH）, propanol （C3H7OH）, and butanol （C4H9OH） upon the viscosity of tetradecyltrimethylammonium bromide （TTAB） solution in the presence or absence of KBr at 30℃was investigated, where the surfactant concentration CS is kept constant. In the absence of KBr, the relative viscosity ηr of TTAB solution increases linearly with the alcohol concentration CA, indicating that the alcohols do not promote micelle formation of TTAB. In the presence of KBr, ηr linearly decreases with CA for C2H5OH, but it exhibits a maximum with increasing CA for C3H7OH or C4H9OH. The facts reveal that C2H5OH or C4H9OH promotes the micelle formation of TTAB. A possible explanation is that the hydrophobicity of the mieellar interior is enhanced by KBr, so that C2H5OH or C4H9OH can dissolve in micelle and promotes micelle formation. In the presence of KCl, which is less efficient in promoting the micelle formation of cationic surfactant, both C3H7OH and C4H9OH have only a slight effect on the micelle formation. In contrast, due to the hydrophilicity, C2H5OH cannot dissolve in micelles in the presence of KBr or KCl.

关键词： Relative viscosity Cationic surfactant Organic additive Hydrophobic interaction

Effect of Coarse Aggregate Size on and Crack Opening in Normal and Relationship between Stress High Strength Concretes

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Journal of Materials science & technology 2005年第5期21卷 691-700页

作者： Jun ZHANG qian LIU Lin WANG Department of Civil Engineering Tsinghua University Beijing 100084 China

Fine and coarse aggregates play an important role in the fracture of concrete. However, quantitative information available on the effect of the coarse aggregate size on the fracture properties of concrete is still limited. In the present paper, the effect of coarse aggregate size （single grade of 5～10, 10～16, 16～20 and 20～25 mm） on stress-crack opening （σ-w） relation in normal and high strength concretes （compressive strength of 40 and 80 MPa, respectively） was studied. The investigation was based on three-point bending tests implemented by fictitious crack analysis. The result shows that coarse aggregate size and cement matrix strength significantly influence the shape of σ-w curve. For a given total aggregate content, in normal strength concrete, smaller size of aggregate leads to a high tensile strength and a sharp stress drop after the peak stress. The smaller the coarse aggregate, the steeper the σ-w curve. By contrast, in high strength concrete, the effect of aggregate size on σ-w relation almost vanishes. A similar σ-w relation is obtained for the concrete except for the case of 20～25 mm coarse aggregate size. The stress drop after the peak stress is more significant for high strength concrete than that for normal strength concrete. Meanwhile, the smaller the coarse aggregate size, the higher the flexural strength. Fracture energy and characteristic length increase with increasing coarse aggregate size in both normal and high strength concretes.

关键词： Aggregate size Stress-crack opening relation Fracture energy Bending test

Biodiversity Sustainability Assessment of Principal Ecosystems in Hebei,china

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Wuhan university Journal of Natural sciences 2007年第4期12卷 749-754页

作者： WANG Hongmei qian Jinping ZHANG Xiulan HE Xiubin Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 Sichuan China Graduate university of Chinese Academy of sciences Beijing 100049 China College of Resources and Environment science Hebei Normal University Shijiazhuang 050016 Hebei China Departerment of Geography Xingtai University Xingtai 054001 Hebei China

Aiming at providing theoretical basis for effective protection of biodiversity, the study presents a cascade method which combines both qualitative and quantitative methods, incorporates basic data with RS（remote sense） technology, and ranks the ecosystems according to its ability of biodiversity sustainability in Hebei Province. The results indicate that the most important areas for protection in Hebei Province are forest and meadow ecosystems in some highlands around Xiaowutai Mountain, Wuling Mountain, North Hebei, Taihang Mountain and East Hebei; grass ecosystems in part of plateau area and North Hebei; and some scattered wetlands in the plain and inshore areas. This method is suitable for undertaking large-scale investigations especially when the data are not adequate or unevenly distributed spatially.

关键词： biodiversity sustainability assessment cascade method ecosystem

Novel synthesis of N-doped graphene as an efficient electrocatalyst towards oxygen reduction

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Nano Research 2016年第3期9卷 808-819页

作者： Ruguanq Ma Xiaodong Ren Bao Yu Xia Yao Zhou Chi Sun qian Liu Jianjun Liu Jiacheng Wang State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of Ceramics Chinese Academy of Sciences 1295 Dingxi Road Shanghai200050 China Shanghai Institute of Materials Genome 99 Shangda Road Shanghai 200444 China School of Chemical and Biomedical Engineering Nanyang Technological University 62 Nanyang Drive Singapore 637459 Singapore

Nitrogen-doped graphene （NG） was successfully synthesized by a novel, facile, and scalable bottom-up method. The annealed NG （NG-A） possessed high specific surface area and a hierarchical porous texture, and exhibited remarkably improved electrocatalytic activity in the oxygen reduction reaction in both alkaline and acidic media. Ab initio molecular dynamic simulations indicated that rapid H transfer and the thermodynamic stability of six-membered N structures promoted the transformation of N-containing species from pyrrolic to pyridinic at 600 ℃ In O2-staturated 0.1 M KOH solution, the half-wave potential （El/2） of NG-A was only 62 mV lower than that of a commercial Pt/C catalyst, and the limiting current density of NG-A was 0.5 ***-2 larger than that of Pt/C. Koutecky-Levich （K-L） plots and rotating ring-disk electrode measurement indicated a four-electron- transfer pathway in NG-A, which could be ascribed to its high content of pyridinic N.

关键词： nitrogen doping graphene moleculardynamic simulation oxygen reduction reaction

The Spatial Statistics Analysis of Housing Market Bubbles

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Journal of Systems science and Information 2017年第3期8卷 250-266页

作者： qian SUN Yong TANG Aimee YANG Management School Hunan City University Department of technology and Society State University of New York at Stony Brook Department of Sociology State University of New York College at Buffalo Business School University of East Anglia

With the incorporation of spatial statistic method, this paper constructs a state-space model of housing market bubbles, discussing the spatial pattern of housing market bubbles in china,and identifying the dynamic evolution process. The results show that: The bubbles of housing market walked along a path from low level to high level and then downsized to a low level during the period of 2009 and 2014, and the highest level stayed at 2011. From overall, the level of housing market bubbles had shown significant spatial autocorrelation and spatial agglomeration. In detail, the direction of North-South in china showed the inverted U shape, i.e., Central region was with high bubbles, and two ends contained low bubbles; from East-West direction, the East had high bubbles and the West contained comparatively low bubbles. Local spatial test indicates that there were some approximate spatial features in housing market bubbles among the adjacent regions. Observed from the level of housing market bubbles, china contained 3 plates: The first was the plate with low bubble level,including 3 provinces in North-East china(provinces of Jilin, Heilongjiang and Liaoning were included,but Dalian in Liaoning province was excluded; the second was the Central and West plate(the provinces of Yunnan, Guizhou, Sichuan, Guangdong, Guangxi, Hunan, Hubei, Gansu, Fujian, Jiangxi and Hainan were included in this plate), which was also featured with low bubble; and the third was Central East plate(provinces or provincial regions of beijing, Tianjin, Hebei, Jiangsu, Zhejiang, Shanghai, Shandong,Anhui, Shanxi, Shaanxi and Inner Mongolia were included), which was characterized as high bubble region.

关键词： housing market bubbles spatial statistics state-space model

On modeling and control of a flexible air-breathing hypersonic vehicle based on LPV method

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Frontiers of Electrical and Electronic Engineering in china 2012年第1期7卷 56-68页

作者： Changyin SUN Yiqing HUANG Chengshan qian Li WANG School of Automation Southeast University Nanjing 210096China College of Information and Control Nanjing University of Infor-mation Science ＆ Technology Nanjing 210044 China

This article develops a polytopic linear pa- rameter varying （LPV） model and presents a non-fragile H2 gain-scheduled control for a flexible air-breathing hypersonic vehicle （FAHV）. First, the polytopic LPV model of the FAHV can be obtained by using Jacobian linearization and tensor-product （TP） model transfor- mation approach, simulation verification illustrates that the polytopic LPV model captures the local nonlinear- ities of the original nonlinear system. Second, based on the developed polytopic LPV model, a non-fragile gain- scheduled control method is proposed in order to reduce the fragility encountered in controller implementation, a convex optimisation problem with linear matrix in- equalities （LMIs） constraints is formulated for designing a velocity and altitude tracking controller, which guar- antees//2 control performance index. Finally, numerical simulations have demonstrated the effectiveness of the proposed approach.

关键词： linear parameter varying (LPV) non- fragile gain-scheduled control flexible air-breathing hy- personic vehicle (FAHV)

Derivative-free reinforcement learning:a review

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Frontiers of Computer science 2021年第6期15卷 75-93页

作者： Hong qian Yang YU National Key Laboratory for Novel Software technology Nanjing UniversityNanjing 210023China

Reinforcement learning is about learning agent models that make the best sequential decisions in unknown *** an unknown environment,the agent needs to explore the environment while exploiting the collected information,which usually forms a sophisticated problem to ***-free optimization,meanwhile,is capable of solving sophisticated *** commonly uses a sampling-andupdating framework to iteratively improve the solution,where exploration and exploitation are also needed to be well ***,derivative-free optimization deals with a similar core issue as reinforcement learning,and has been introduced in reinforcement learning approaches,under the names of learning classifier systems and neuroevolution/evolutionary reinforcement *** such methods have been developed for decades,recently,derivative-free reinforcement learning exhibits attracting increasing ***,recent survey on this topic is still *** this article,we summarize methods of derivative-free reinforcement learning to date,and organize the methods in aspects including parameter updating,model selection,exploration,and parallel/distributed ***,we discuss some current limitations and possible future directions,hoping that this article could bring more attentions to this topic and serve as a catalyst for developing novel and efficient approaches.

关键词： reinforcement learning derivative-free optimization neuroevolution reinforcement learning neural architecture search

Synthesis, Fluorescence and Dielectric Properties of Two Novel Compounds Based on Triethylenediamine Derivatives

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Chinese Journal of Structural Chemistry 2019年第4期38卷 605-612页

作者： DENG Si-Yu qian Xiu LI Mu CHEN Li-Zhuang School of Environmental and Chemical Engineering Jiangsu University of Science and Technology

Two compounds C_8H_(18)N_2Br_3Mn_(0.5)(1) and C_(12)H_(26)N_2Cl_4Mn(2) based on triethylenediamine derivatives were synthesized by solution method and were characterized by elemental analysis, infrared spectroscopy, single-crystal X-ray structure analysis, fluorescence test, circular dichroism(CD) analysis and dielectric measurement, respectively. According to single-crystal X-ray determination, compound 1 crystallizes in the cubic system, space group Pa3 with a = b = c = 13.7246(5) ?, Z = 24, V = 2585.2(3) ?~3; and compound 2 crystallizes in the orthorhombic system, space group P212121 with a = 7.9716(13), b = 15.309(3), c = 15.804(3) ?, Z = 4 and V = 1928.7(6) ?3. Fluorescent analysis of compound 1 showed an intense emission band at 670 nm when the exciting radiation was set at 378 nm and fluorescent analysis of compound 2 showed an intense emission band at 515 nm when the exciting radiation was set at 363 nm. Dielectric constants of compounds 1 and 2 were measured at different frequencies with temperature variation.

关键词： triethylenediamine derivatives fluorescent compounds crystal structure permittivity properties

Hepcidin and OX26-hepcidin inhibit expression of iron uptake proteins in mice brain and neurons

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Hepcidin and OX26-hepcidin inhibit expression of iron uptake...