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Photoinduced Bending and Curling Motions in Molecular Microcrystals of Naphthyl Meldrum’s Acid Derivative Based on E-to-Z Photoisomerization

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Chemical Research in Chinese Universities 2024年第5期40卷 907-913页

作者： zhang Xiaowen XU Tianyi zhang chenchen TONG Fei Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research CenterFrontiers Science Center for Materiobiology and Dynamic ChemistrySchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai200237P.R.China

Dynamic photoresponsive molecular crystals are promising candidates for making intelligent devices and materials in the ***,we synthesized a new photoactive molecule(E)-2,2-dimethyl-5-[3-(naphthalen-1-yl)allylide]-1,3-dioxane-4,6-dione[(E)-DNADD]that undergoes an E-to-Z photoisomerization in both liquid solution and solids when exposed to visible light(405 nm).Compared to the bulk crystals,the photoresponsive behavior in microcrystals was profoundly *** crystalline(E)-DNADD microplate crystals exhibit robust motions,including bending,curling,and coiling under light *** photoproduct conversion of the photochemical reaction in the microplate is no more than 20%,while the large bending curvature of the coiled illuminated samples was estimated at approximately 150–300 mm−1,comparable to some photoactive *** results indicate that shrinking crystal dimensions can boost the photoresponses in molecular crystals and provide a facile strategy for developing dynamic molecular crystals at the microscopic scale.

关键词： Photochemistry Molecular crystal E-to-Z photoisomerization Photoinduced motion

Damage on lining concrete in highway tunnels under combined sulfate and chloride attack

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Frontiers of Structural and Civil Engineering 2018年第3期12卷 331-340页

作者： Rongrong YIN chenchen zhang Qing WU Baocheng LI He XIE School of Architeture and Civil Engineering Jiangsu University of Science and Technology Zhenjiang 212003 China

The combined effect from sulfate and chloride is one of the important reasons to cause the damage of lining concrete in highway tunnels. To investigate the effect of chloride ions on the corrosion of lining concretes under sulfate attack, ultrasonic detecting, compression test and X-ray Diffraction （XRD） were performed on the concretes to obtain the ultrasonic velocity, corrosion thickness, compression strength and corrosion products. The ultrasonic results, compression strength and XRD patterns confirmed that the existence of chloride certainly depressed the corrosion damage on the lining concretes under sulfate attack, and the depressing effect increased with the content of chloride in the composite solution. The corrosion damage on the concretes experienced three stages independent of the composition of corrosive solution： initial slower enhancement on the strength, stabilization period and linear degradation period. The existence of chloride mainly affected the final degradation stage and obviously decreased the corrosion thickness.

关键词： lining concrete sulfate chloride compression ultrasonic

Analytical Modelling and Experiment of Novel Rotary Electro-Mechanical Converter with Negative Feedback Mechanism for 2D Valve

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Chinese Journal of Mechanical Engineering 2022年第5期35卷 162-182页

作者： Bin Meng Mingzhu Dai Chenhang Zhu chenchen zhang Chuan Ding Jian Ruan College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China

The manufacturing of spiral groove structure of two-dimensional valve(2D valve)feedback mechanism has shortcomings of both high cost and *** paper presents a novel configuration of rotary electro-mechanical converter with negative feedback mechanism(REMC-NFM)in order to replace the feedback mechanism of spiral groove and thus reduce cost of valve *** order to rapidly and quantitative evaluate the driving and feedback performance of the REMC-NFM,an analytical model taking leakage flux,edge effect and permeability nonlinearity into account is formulated based on the equivalent magnetic circuit *** the model is properly simplified in order to obtain the optimal pitch *** simulation is used to study the influence of crucial parameters on the performance of REMC-NFM.A prototype of REMC-NFM is designed and machined,and an exclusive experimental platform is *** torque-angle characteristics,torque-displacement characteristics,and magnetic flux density in the working air gap with different excitation currents are *** experimental results are in good agreement with the analytical and FEM simulated results,which verifies the correctness of the analytical *** torque-angle characteristics,the overall torque increases with both current and rotation angle,which reaches about 0.48 N·m with 1.5 A and 1.5°.While for torque-displacement characteristics,the overall torque increases with current yet decrease with armature displacement due to the negative feedback mechanism,which is about 0.16 N·m with 1.5 A and 0.8 ***,experimental results of conventional torque motor are compared with counterparts of REMC-NFM in order to validate the simplified *** research indicates that the REMC-NFM can be potentially used as the electro-mechanical converter for 2D valves in civil servo areas.

关键词： Electro-mechanical converter Magnetic circuit topology Analytical modeling 2D valve

Theoretical and experimental investigation on the efficiency of a novel roller piston pump

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2023年第9期24卷 762-781页

作者： chenchen zhang Yiren ZANG Heyuan WANG Bin MENG Sheng LI Jian RUAN College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China

This study presents a novel roller piston pump,in which a cam guide-roller type rolling support is adopted to replace the sliding pair support of the swash plate-slipper pair to achieve the oil suction and discharge of the piston *** addition,the shaft distribution is used to replace the original valve plate distribution and the driving shaft is used as the distribution shaft to remove the valve plate structure,which greatly simplifies the design of the axial piston *** a configuration largely reduces the number of sliding friction pairs of the pump,and avoids the influence of the sliding friction pair on it under high-speed and variable-speed ***,mathematical models of the mechanical and volumetric efficiencies of the roller pump are deduced respectively through force analysis and the compressibility *** on the numerical simulation of MATLAB and AMESim,the effects of load pressure and rotational speed on mechanical and volumetric efficiencies are studied respectively,and it is verified that the roller pump has no structural flow *** prototype pump is then designed and built,along with a special test *** outlet pressure,outlet flow,and torque of the pump under different load pressures and rotational speeds are measured,and the mechanical and volumetric efficiencies of the prototype pump under various load pressures and rotational speeds are *** experimental results are in good agreement with the simulated *** the load pressure is 8 MPa and the speed is 5000 r/min,the mechanical and the volumetric efficiencies are 85.5% and 96.8%,*** the speed is increased to 10000 r/min,the mechanical and the volumetric efficiencies are 66.7% and 95.6%,*** experimental results show that the proposed roller piston pump has excellent efficiency under wide-speed and high-speed conditions and can be a potential solution as a fuel pump in aerospace fuel systems.

关键词： Roller piston pump Shaft distribution mechanism Mechanical efficiency Volumetric efficiency Aerospace pump

Small-molecule based thermally activated delayed fluorescence materials with dual-emission characteristics

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Science China Chemistry 2021年第4期64卷 534-546页

作者： Xuping Li Shen Shen chenchen zhang Miaoqing Liu Jianjun Lu Liangliang Zhu Key Laboratory of Coal Science and Technology Ministry of Education and Shanxi Province Taiyuan University of TechnologyTaiyuan 030024China State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200438China

Organic thermally activated delayed fluorescence(TADF)emitters have attracted increasing concerns,owing to their atypical photophysical features that can pave the way to the innovative engineering *** cutting-edge type of luminescent molecules,however,most of them only exert a single-wavelength emission from the lowest excited state,according to Kasha’s *** develop their potential applications in multicolor luminescence and multi-functional luminescent probes for biological imaging,researchers have begun to turn their attention to design organic TADF molecules with dual-emission characteristics,by employing an additional fluorescence,phosphorescence,or TADF signal within a single-component *** herein summarized the design principles as well as the luminescence mechanism of organic donor-acceptor TADF compounds with dual-emission characteristics,the superiority of which can cover unique material applications in modern luminescencerelated fields.

关键词： thermally activated delayed fluorescence dual-emission excited states donor-acceptor

Synthesis, structure and photocatalysis properties of two 3D Isostructural Ln (Ⅲ)-MOFs based 2,6-Pyridinedicarboxylic acid

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Journal of Materials Science & Technology 2018年第9期34卷 1526-1531页

作者： chenchen zhang Siyue Wei Lixian Sun Fen Xu Pengru Huang Hongliang Peng School of Material Science and Engineering Guilin University of Electronic Technology Guilin 541004 China Guangxi Key Laboratory of Information Materials Guilin 541004 China Guangxi Collaborative Innovation Center of Structure and Property for New Energy and Materials Guilin 541004 China

Two new 3 D metal-organic frameworks（MOFs） named [Pr2（PDA）3-3 H2 O]-H2 O（1） and[Nd2（PDA）3-3 H2 O] H2 O（2） [2,6-Pyridinedicarboxylic acid（H2 PDA）] were synthesized by solvothermal method. They were characterized by elemental analyses（EA）, infrared spectroscopy（FT-IR）, thermogravimetric analysis（TG）, photocatalysis performance and single crystal X-ray diffraction studies（XRD）.The XRD analysis indicated that MOFs（1） and（2） both belong to the monoclinic system with space group P2（1）/C. The structural model were drawn by the diamond software, and the structure revel that MOFs（1） and（2） adopt three-dimensional（3 D） frameworks constructed by cross-linking of one-dimensional（1 D） infinite chain secondary building unit（SBU） by 2,6-Pyridinedicarboxylic acid and hydrogen bond as linker. These frameworks feature channels inside which coordinated H20 solvent molecules are located. Thermogravimetric analysis showed that both MOFs are thermally stable, the photocatalytic evaluation showed the materials have a good prospect in degration methylene blue. As for complex1, the decomposition efficiency of Methylene blue was about 91.08% after 130 min and the complex 2 reach 90.45% after 160 min under the sun light.

关键词： Metal-organic frameworks Solvothermal method Photocatalysis performance

Extreme Temperature Change of the Last 110 Years in Changchun,Northeast China

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Advances in Atmospheric Sciences 2020年第4期37卷 347-358,I0002-I0006页

作者： Xiujing YU Guoyu REN Panfeng zhang Jingbiao HU Ning LIU Jianping LI chenchen zhang Jilin Climate Center Changchun 130062China Department of Atmospheric Science School of Environmental StudiesChina University of GeosciencesWuhan 430074China Laboratory for Climate Studies National Climate CenterChina Meteorological AdministrationBeijing 100081China Jilin Province Weather Modification Office Changchun 130062China Institute of Meteorological Sciences of Jilin Province Changchun 130062China

In China and East Asia,the long-term continuous observational data at daily resolution are insufficient,and thus there is a lack of good understanding of the extreme climate variation over the last 100 years *** this study,the extreme temperature indices defined by ETCCDI(Expert Team on Climate Change Detection and Indices)and local meteorological administrations were analyzed for Changchun City,Northeast China,by using the daily maximum temperature(Tmax)and daily minimum temperature(Tmin)over 1909?*** results showed that extreme cold events,such as cold days,cold nights,frost days,icing days,and low temperature days,decreased significantly at rates of?0.41 d(10 yr)^?1,?1.45 d(10 yr)^?1,?2.28 d(10 yr)^?1,?1.16 d(10 yr)?1 and?1.90 d(10 yr)^?1,*** nights increased significantly at a rate of 1.71 d(10 yr)^?1,but warm days decreased slightly and the number of high temperature days decreased at a rate of?0.20 d(10 yr)?*** frequency of cold surge events increased significantly at a rate of 0.25 d(10 yr)^?1,occurring mainly from the mid-1950s to *** average Tmax,average Tmin and extreme Tmin increased at rates of 0.09℃(10 yr)^?1,0.36℃(10 yr)^?1 and 0.54℃(10 yr)^?1,respectively;and extreme Tmax decreased significantly at a rate of?0.17℃(10 yr)^?*** 1909?2018,1951?2018 and 1979?2018,the indices related to cold events decreased,while the trends of the indices related to warm events were different for different periods.

关键词： extreme temperature climate change long-term series observation Changchun Northeast China

An insight into the enhanced mechanism of Ru–MoO_(2)interfacial chemical bonding for hydrogen evolution reaction in alkaline media

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Nano Research 2023年第2期16卷 2230-2235页

作者： Ying Yuan Wei Han chenchen zhang Qi Sun Yingxin Hao Jiamin Zhao Jinsheng Zhao Xiujuan Zhong Ningqiang zhang School of Chemistry and Chemical Engineering Liaocheng UniversityLiaocheng 252059China National Energy R&D Center for Petroleum Refining Technology Research Institute of Petroleum ProcessingChina Petroleum&Chemical Corporation(SINOPEC)Beijing 100083China Institute for Catalysis Hokkaido UniversityN-21W-10SapporoHokkaido 001-0021Japan

An effective strategy was proposed to control the formation of the interfacial bonding between Ru and molybdenum oxide support to stabilize the Ru atoms with the aim to enhance the hydrogen evolution reaction(HER)activity of the resultant catalysts in alkaline *** different interfacial chemical bonds,including Ru–O,Ru–O–Mo,and mixed Ru–Mo/Ru–O–Mo,were prepared using an induced activation strategy by controlling the composition of reducing agents in the calcination *** the regulation mechanism of the interfacial chemical bonds in molybdenum oxide supported Ru catalysts for optimizing HER activity was investigated by density functional theory(DFT)and experimental *** found that a controlled interfacial chemical Ru–O–Mo bonding in Ru-MoO_(2)/C manifests a 12-fold activity increase in catalyzing the hydrogen evolution reaction relative to the conventional metal/metal oxide catalyst(Ru-O-MoO_(2)/C).In a bifunctional effect,the interfacial chemical Ru-O-Mo sites promoted the dissociation of water and the production of hydrogen intermediates that were then adsorbed on the nearby Ru surfaces and recombined into molecular *** compared,the nearby Ru surfaces in Ru–Mo bonding have weak adsorption capacity for the generation of these hydrogen intermediates,resulting in a 5-fold increase HER activity for Ru-Mo-MoO_(2)/C catalyst compared with Ru-O-MoO_(2)/C.

关键词： interfacial chemical bonds alkaline media hydrogen evolution reaction Ru–O–Mo

Freeze-drying and hot-pressing strategy to embed two-dimensional Ti_(0.87)O_(2) monolayers in commercial polypropylene films with enhanced dielectric properties

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Journal of Advanced Ceramics 2021年第2期10卷 368-376页

作者： Wenchao Tian Fei Yan Cailing Cai Zeyi Wu chenchen zhang Ting Yin Sijia Lao Linfeng Hu Department of Materials Science Fudan UniversityShanghai200433China State Grid Anhui Electric Power Institute Hefei230022China China Electric Power Research Institute Beijing100192China

The dielectric capacitor has been widely used in advanced electronic and electrical power systems due to its capability of ultrafast charging–discharging and ultrahigh power ***,its energy density is still limited by the low dielectric constant(≈2.2)of the commercial dielectric polypropylene(PP).The conventional enhancement strategy by embedding inorganic fillers in PP matrix is still difficult and challenging due to that PP hardly dissolves in any inorganic/organic *** this work,we develop a new strategy including freeze-drying,surface functionalization,and hot-pressing to incorporate Ti_(0.87)O_(2) monolayers in PP film.A series of uniform composited Ti_(0.87)O_(2)@PP film has been successfully fabricated with Ti0.87O2 content range of 0–15 wt%.The maximum dielectric constant of the as-prepared Ti_(0.87)O_(2)@PP film is 3.27 when the Ti_(0.87)O_(2) content is 9 wt%,which is about 1.5 times higher than that of pure *** study provides a feasible strategy to embed two-dimensional material into commercial PP thin-film with superior dielectric performance for practical application.

关键词： Ti_(0.87)O_(2)nanosheets polypropylene(PP) freeze-drying surface functionalization hot-pressing dielectric constant