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A novel highly selective fluorescent chemosensor for Hg(Ⅱ) in fully aqueous media

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Chinese Chemical Letters 2007年第10期18卷 1209-1212页

作者： Xiang ming meng Man Zhou Zhu Qing Xiang Guo Department of Chemistry University of Science and Technology of China Hefei 230026 China

A novel fluorescent Hg^2＋ chemosensor based on dithia-dioxa-monoaza crown ether was synthesized in four steps from inexpensive starting materials. This new sensor exhibited very strong fluorescence response to Hg^2＋... 详细信息

关键词： Hg^2+ sensor Fluorescence PET Fluorescein Selectivity

Effects of the Bridging Bond on Electronic Transport in a D-B-A Device

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Chinese Physics Letters 2013年第8期30卷 136-139页

作者： LI ming-Jun LONG meng-Qiu XU Hui School of Physics and Electronics Central South UniversityChangsha 410083 Institute of Super Microstructure and Ultrafast Process Central South UniversityChangsha 410083

By using density functional theory combined with a nonequilibrium Green's functions approach,the electronic transport properties of different bridges connecting benzene-based heterojunction molecular devices are *** focus on the effects of the bridging bond polarity and its bond *** results show that the polar bond plays a significant role in determining the overall conductance of the molecular *** effects of a current plateau and the negative differential resistance can be *** simulation results suggest that the proposed models may be helpful for designing practical molecular devices.

关键词： bridges connecting bridging

Development and evaluation of the refined zenith tropospheric delay(ZTD)models

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Satellite Navigation 2021年第1期2卷 296-304页

作者： Fei Yang Xiaolin meng Jiming Guo Debao Yuan ming Chen College of Geoscience and Surveying Engineering China University of Mining and Technology-Beijing100083 BeijingChina Global Geospatial Engineering Ltd. The Sino-UK Geospatial Engineering Centre18 Radford Bridge RoadNottingham NG81NAUK School of Geodesy and Geomatics Wuhan University129 Luoyu RoadWuhan 430079China National Geomatics Center of China Beijing 100830China.

The tropospheric delay is a significant error source in Global Navigation Satellite System(GNSS)positioning and *** is usually projected into zenith direction by using a mapping *** is particularly important to establish a model that can provide stable and accurate Zenith Tropospheric Delay(ZTD).Because of the regional accuracy difference and poor stability of the traditional ZTD models,this paper proposed two methods to refine the Hopfield and Saastamoinen ZTD *** is by adding annual and semi-annual periodic terms and the other is based on Back-Propagation Artificial Neutral Network(BP-ANN).Using 5-year data from 2011 to 2015 collected at 67 GNSS reference stations in China and its surrounding regions,the four refined models were *** tropospheric products at these GNSS stations were derived from the site-wise Vienna Mapping Function 1(VMP1).The spatial analysis,temporal analysis,and residual distribution analysis for all the six models were conducted using the data from 2016 to *** results show that the refined models can effectively improve the accuracy compared with the traditional *** the Hopfield model,the improvement for the Root Mean Square Error(RMSE)and bias reached 24.5/49.7 and 34.0/52.8 mm,*** values became 8.8/26.7 and 14.7/28.8 mm when the Saastamoinen model was refined using the two *** exploration is conducive to GNSS navigation and positioning and GNSS meteorology by providing more accurate tropospheric prior information.

关键词： GNSS Tropospheric delay ZTD Refined model ANN

Innovation Analysis Approach to Design Parameters of High Speed Train Carriage and Their Intrinsic Complexity Relationships

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Chinese Journal of Mechanical Engineering 2017年第5期30卷 1091-1100页

作者： Shou-Ne Xiao ming-meng Wang Guang-Zhong Hu Guang-Wu Yang State Key Laboratory of Traction Power Southwest Jiaotong University School of Mechanical Engineering Sichuan University of Science & Engineering

In view of the problem that it＇s difficult to accurately grasp the influence range and transmission path of the vehicle top design requirements on the underlying design parameters. Applying directed-weighted complex network to product parameter model is an important method that can clarify the relationships between product parameters and establish the top-down design of a product. The relationships of the product parameters of each node are calculated via a simple path searching algorithm, and the main design parameters are extracted by analysis and comparison. A uniform definition of the index formula for out-in degree can be provided based on the analysis of out- in-degree width and depth and control strength of train carriage body parameters. Vehicle gauge, axle load, crosswind and other parameters with higher values of the out-degree index are the most important boundary condi- tions; the most considerable performance indices are the parameters that have higher values of the out-in-degree index including torsional stiffness, maximum testing speed, service life of the vehicle, and so on; the main design parameters contain train carriage body weight, train weight per extended metre, train height and other parameters with higher values of the in-degree index. The network not only provides theoretical guidance for exploring the relationship of design parameters, but also further enriches the appli- cation of forward design method to high-speed trains.

关键词： Train carriage body parameters Complexnetwork Width influence Depth influence Parametercontrol strength

Fracture Behavior of Cold Sprayed 304 Stainless Steel Coating During Cold Rolling

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Journal of Iron and Steel Research International 2012年第11期19卷 57-63页

作者： meng Xian-ming ZHANG Jun-bao HAN Wei ZHAO Jie School of Materials Science and Engineering Dalian University of Technology Dalian 116024 LiaoningChina Baosteel Research Institute Baoshan Iron and Steel Co Ltd Shanghai 201900 China

The fracture behavior of cold sprayed 304 stainless steel coating in cold rolling process was studied. The 304 stainless steel coatings were deposited on low carbon steel substrate by cold gas dynamic spray （CGDS） and then cold rolled, respectively. The fracture morphology of the coatings was observed and analyzed, and the crack distri- butions along the longitudinal rolling direction of the coatings were also investigated and discussed. The results showed that the cohesive strength of the cold sprayed 304 stainless steel coating was too low to be cold rolled. Mi crocracks were formed in the as-sprayed coatings and ran perpendicularly to the rolling direction. The spacing dis- tance between these cracks decreased with the increase of the cold rolling reduction. In addition, it was also found that the initial crack generated at the surface of the coating and propagated from the surface to the interface along the weakly bonded particles. A theoretical analysis was developed for the coating fracture. It gave a critical minimum cohesive bonding strength of the coating for non-breaking in cold rolling process. The crack propagation manner of the cold rolled coatings was also discussed.

关键词： fracture cold spraying cold rolling 304 stainless steel coating microstructure

Transverse phase space reconstruction study in Shanghai soft X-ray FEL facility

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Nuclear Science and Techniques 2018年第1期29卷 9-15页

作者： Qing-Lin Yu Duan Gu meng Zhang ming-Hua Zhao Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China University of Chinese Academy of Sciences Beijing 100049China

Phase space is one of the most important parameters used to describe beam properties. Computer tomography, as a method for reconstructing phase space and measuring beam emittance, has been used in many accelerators over the past few decades. In this paper, we demonstrate a transverse phase space reconstruction study in the Shanghai soft X-ray free electron laser facility. First,we discuss the basic principles of phase space reconstruction and the advantage of reconstructing beam distribution in normalized phase space. Then, the phase space reconstruction results by different computer tomography methods based on the maximum entropy(MENT) algorithm and the filtered back projection algorithm in normalized phase space are presented. The simulation results indicate that,with proper configuration of the phase advance between adjacent screens, the MENT algorithm is feasible and has good efficiency. The beam emittance and Twiss parameters are also calculated using the reconstructed phase space.

关键词： Emittance Phase space reconstruction MENT algorithm SXFEL

Using simulation in layout verification of solar module assembly workshop

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International Journal of Modeling, Simulation, and Scientific Computing 2018年第2期9卷 138-160页

作者： Zhongqing Liao ming Cong Dong Liu Fanjie meng School of Mechanical Engineering Dalian University of Technology No.2 Linggong RoadDalian City 116024P.R.China Research and Development Department Yingkou Jinchen Machinery Co. Ltd.No.95 XinGang Main StreetYingkou City 115000P.R.China

Facility layout problem(FLP)contemplates the optimization of space utilization,costs,and material *** simulation softwares are commonly used to validate layouts by simulating the real world material flow and production *** validate a layout scenario of a solar module assembly workshop,a 3D simulation model is presented which was designed on VisualComponents *** begin with,we introduce the layout characteristics and use the systematic layout planning(SLP)method to design the block layout of ***,we built components library which contains all the facilities needed in the production line,specifically conveyors,processing equipments,robots,***,we have established a simulation layout model using the components in the customized library according to the block layout,and configured the components which were allocated in the layout by setting the parameters and building the connection between components via *** improve the performance of the workshop,we have found the best work-in-process(WIP)value for the workshop and the optimal number of ***,the layout model was used to test collision and *** demonstrated the production process in a realistic simulation environment which helped in the sales process as *** reusable component models we have built make it easy to build a layout within a short time and validate the effectiveness of the layout scenarios for any other projects.

关键词： Facility layout problem production line simulation realistic simulation VisualComponents material flow work-in-process.

Thickness measurement approach for plasma sprayed coatings using ultrasonic testing technique

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中国有色金属学会会刊：英文版 2004年第z1期14卷 88-91页

作者： LIN Li LI Xi-meng XU Zhi-hui LEI ming-kai NDT&E Laboratory NDT&E Laboratory NDT&E Laboratory Surface Engineering Laboratory Dalian University of Technology Dalian 116024 China

The special ultrasonic testing system has been developed for thickness measurement of plasma sprayed coatings. The ultrasonic immersion method was used to obtain stable coupling condition and avoid other disadvantages of contact method. Spherical acoustic lens were designed to focus ultrasonic beam so as to improve beam directivity and concentrate ultrasonic energy. To increase testing precision and avoid mussy wave signals, moderate pulse width and frequency of the transducer has been selected. The displacement of transducer in X-Y-Z directions was precisely manipulated by step-controlled system to insure the accuracy of focus length and repetition of measurement. Optimized testing conditions (with the transducer of center frequency of 10 MHz and crystal diameter of 8 mm, focus length of 9.5 mm, diameter of focal column of 0. 1 mm and length of focal column of 0.27 mm) were selected to determine the thickness between 285 -414 μm of ZrO2 coatings plasma sprayed on the nickel based superalloy. The frequency interval of the periodic extremums in ultrasonic power spectra decreases with increasing coating thickness. The ultrasonic results accord with those of metallographical method.

关键词： plasma sprayed coatings thickness measurement ultrasonic testing interference

Tensor Coupling Effects on Spin Symmetry in the Anti-Lambda Spectrum of Hypernuclei

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Chinese Physics Letters 2011年第9期28卷 80-83页

作者： SONG Chun-Yan YAO Jiang-ming meng Jie State Key Laboratory of Software Development Environment and School of Physics and Nuclear Energy EngineeringBeihang UniversityBeijing 100191 School of Physical Science and Technology Southwest UniversityChongqing 400715 State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871 School of Physics and Nuclear Energy Engineering Beihang UniversityBeijing 100191 Department of Physics University of StellenboschStellenboschSouth Africa

Effects ofΛΛω−tensor coupling on the spin symmetry ofΛspectra inΛ−nucleus systems are studied using relativistic mean-field *** 12C+Λas an example,it is found that the tensor coupling enlarges the spin−orbit splittings ofΛby a factor of 5 but has a negligible effect on the wave functions ofΛ.Similar conclusions are observed in otherΛ−nuclei,including ^(16)O+Λ,^(40)Ca+Λand ^(208)Pb+Λ.It is indicated that the spin symmetry in anti-lambda-nucleus systems is still a good approximation irrespective of the tensor coupling.

关键词： theory tensor symmetry