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Enantioselective Degradation of Rac-Metolachlor and S-Metolachlor in Soil

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Pedosphere 2006年第4期16卷 489-494页

作者： MA Yun LIU wei-ping WEN Yue-Zhong Institute of Environmental Science Zhejiang University P. O. Box 31 74 Hangzhou 310029 （China） Researeh Center of Green Chirality College of Biological and Environmental Engineering Zhejiang University of Technology Hangzhou 310015 （China）

Separation of chiral enantiomers and the dissipation of rac-metolachlor and S-metolachlor in soil were evaluated using achiral high-performance liquid chromatography (HPLC) and chiral gas chromatography (GC) methods. Under the experimental conditions the possible metabolite was considered to be N-(2-ethyl-6-methyl-phenyl)-2-hydroxy-acetamide. Because of the presence of two chiral elements (asymmetrically substituted carbon and chiral axis), the baseline separation of metolachlor enantiomers was not achieved. S-metolachlor degraded faster in soil than rac-metolachlor. After a 42-day incubation, 73.4% of rac-metolachlor and 90.0% of S-metolachlor were degraded. However, due to the absence of biological processes the degradation process in sterilized soil showed no enantioselectivity. The results indicated that enantioselective degradations could greatly affect the environmental fate of metolachlor and should be considered when the environmental behavior of these compounds was assessed.

关键词： chiral separation degradation rac-metolachlor S-metolachlor soil

Sensitivity of the Ag/SiO_(2) Mesoporous Composite on Ambiences in the Optical Absorption

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Chinese Physics Letters 1997年第2期14卷 138-140页

作者： CAI wei-ping ZHANG Li-de Institute of Solid State Physics Chinese Academy of SciencesHefei 230031

The influence of ambient conditions on the optical absorption has been investigated for the porous silica dispersed with silver nano-particles(about 3nm)within its *** has been shown that in the process of alternative exposure to the ambience and annealing,this new material assumes the optical memory effect and the reversible transition between the transparency and opacity in the visible wave band.

关键词： silver transparency ambient

Synthesis and Structure of 5-Amino-6-(4-fluorophenylamino)-3-methylthio-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one

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Chinese Journal of Structural Chemistry 2006年第9期25卷 1105-1109页

作者： WANG Hong-Qing ZHOU wei-ping LIU Zhao-Jie College of Chemistry ＆ Chemical Engineering Nanhua University Hengyang 421001 China College of Chemistry Central China Normal University Wuhan 430079 China Key Laboratory of Pesticide Chemistry ＆ Application Technology Ministry of Agriculture Beijing 100094 China

The title compound （C18H15FN6OS） has been synthesized and its crystal structure was determined by X-ray analysis. The crystal belongs to monoclinic system, space group P2 1/n with a = 13.983（10）, b = 7.337（5）, c = 16.702（12） A, α = 90, β = 98.277（12）, γ = 90°, V = 1696（2） A^3, Z = 4, Dc= 1.498 g/cm^3, Mr = 382.42,μ = 0.224 mm^-1, F（000） = 792, the final R = 0.0362 and wR = 0.0878 for 2579 observed reflections with 1 〉 2σ（I）. In the title compound, the atoms of C（1 ）, C（2）, C（3）, C（4）, C（5）, N（1）, N（2）, N（3）, N（4）, N（5）, N（6）, O（1） and S（1） form a fully delocalized system with the average deviation of 0.0307 A. There exists a part of electron delocalization over the planes of Ⅰ （pyrazolo[3,4-d]pyrimidin-4-one moiety）, Ⅱ （phenyl moiety） and Ⅲ （p-fluorophenylamine moiety）. In the molecule, intermolecular hydrogen bonds between N（6）-H（6）…O（1） and C（ 15）-H（15）…O（ 1 ） are observed.

关键词： 1,5-dihydroe synthesis crystal structure

Bi-variable damage model for fatigue life prediction of metal components

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Acta Mechanica Sinica 2011年第3期27卷 416-425页

作者： Miao Zhang Qing-Chun Meng Xing Zhang wei-ping Hu Division 508 School of Aeronautic Science and Engineering Beihang University 100191 Beijing China

Based on the theory of continuum damage mechanics,a bi-variable damage mechanics model is developed,which,according to thermodynamics,is accessible to derivation of damage driving force,damage evolution equation and damage evolution criteria. Furthermore,damage evolution equations of time rate are established by the generalized Drucker＇s postulate. The damage evolution equation of cycle rate is obtained by integrating the time damage evolution equations,and the fatigue life prediction method for smooth specimens under repeated loading with constant strain amplitude is constructed. Likewise,for notched specimens under the repeated loading with constant strain amplitude,the fatigue life prediction method is obtained on the ground of the theory of conservative integral in damage mechanics. Thus,the material parameters in the damage evolution equation can be obtained by reference to the fatigue test results of standard specimens with stress concentration factor equal to 1,2 and 3.

关键词： Bi-variable damage model - Damage evolution equation . Life prediction - Fatigue . Damage mechanics

Two-Dimensional Spatial Solitons in Nematic Liquid Crystals

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Communications in Theoretical Physics 2009年第2期51卷 324-330页

作者： ZHONG wei-ping YANG Zheng-ping XIE Rui-Hua Milivoj Beliè Goong Chen Department of Electronic Engineering Shunde College Shunde 528300 China Laboratory of Laser Sports Medicine College of Sports Science/Life Science South China Normal University Guangzhou 510631 China Department of Mathematics Texas A ＆ M University College Station TX 77843 USA Texas A＆M University at Qatar P.O. Box 23874 Doha Qatar

We study the propagation of spatial solitons in nematic liquid crystals, using the self-similar method. Analytical solutions in the form of self-similar solitons are obtained exactly. We confirm the stability of these solutions by direct numerical simulation, and find that the stable spatial solitons can exist in various forms, such as Oaussian solitons, radially symmetric solitons, multipole solitons, and soliton vortices.

关键词： nonlinear optics spatial solitons self-similar method nematic liquid crystals

A Tracking Registration Method for Augmented Reality Based on Multi-modal Template Matching and Point Clouds

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International Journal of Automation and computing 2021年第2期18卷 288-299页

作者： Peng-Xia Cao Wen-Xin Li wei-ping Ma Lanzhou Institute of Physics China Academy of Space TechnologyLanzhou 730000China

In order to overcome the defects where the surface of the object lacks sufficient texture features and the algorithm cannot meet the real-time requirements of augmented reality,a markerless augmented reality tracking registration method based on multimodal template matching and point clouds is *** method first adapts the linear parallel multi-modal LineMod template matching method with scale invariance to identify the texture-less target and obtain the reference image as the key frame that is most similar to the current ***,we can obtain the initial pose of the camera and solve the problem of re-initialization because of tracking registration interruption.A point cloud-based method is used to calculate the precise pose of the camera in real *** order to solve the problem that the traditional iterative closest point(ICP)algorithm cannot meet the real-time requirements of the system,Kdtree(k-dimensional tree)is used under the graphics processing unit(GPU)to replace the part of finding the nearest points in the original ICP algorithm to improve the speed of tracking *** the same time,the random sample consensus(RANSAC)algorithm is used to remove the error point pairs to improve the accuracy of the *** results show that the proposed tracking registration method has good real-time performance and robustness.

关键词： Augmented reality markerless tracking registration LineMod iterative closest point(ICP)algorithm

Binocular Vision Object Positioning Method for Robots Based on Coarse-fine Stereo Matching

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International Journal of Automation and computing 2020年第4期17卷 562-571页

作者： wei-ping Ma Wen-Xin Li Peng-Xia Cao Lanzhou Institute of Physics China Academy of Space TechnologyLanzhou 730000China

In order to improve the low positioning accuracy and execution efficiency of the robot binocular vision,a binocular vision positioning method based on coarse-fine stereo matching is proposed to achieve object *** random fern is used in the coarse matching to identify objects in the left and right images,and the pixel coordinates of the object center points in the two images are calculated to complete the center *** the fine matching,the right center point is viewed as an estimated value to set the search range of the right image,in which the region matching is implemented to find the best matched point of the left center ***,the similar triangle principle of the binocular vision model is used to calculate the 3D coordinates of the center point,achieving fast and accurate object ***,the proposed method is applied to the object scene images and the robotic arm grasping *** experimental results show that the average absolute positioning error and average relative positioning error of the proposed method are 8.22 mm and 1.96%respectively when the object's depth distance is within 600 mm,the time consumption is less than *** method can meet the needs of the robot grasping system,and has better accuracy and robustness.

关键词： Object positioning stereo matching random fern normalized cross correlation binocular vision model

Coupled Responses of Sewol,Twin Barges and Slings During Salvage

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China Ocean Engineering 2018年第2期32卷 226-235页

作者： YAO Zong WANG wei-ping JIANG Yan CHEN Shi-hai Shanghai Salvage Company Shanghai 200090China

Korean Sewol is successfully lifted up with the strand jack system based on twin barges. During the salvage operation, two barges and Sewol encounter offshore environmental conditions of wave, current and wind. It is inevitable that the relative motions among the three bodies are coupled with the sling tensions, which may cause big dynamic loads for the lifting system. During the project engineering phase and the site operation, it is necessary to build up a simulation model that can precisely generate the coupled responses in order to define a suitable weather window and monitor risks for the salvage operation. A special method for calculating multibody coupled responses is introduced into Sewol salvage project. Each body’s hydrodynamic force and moment in multibody configuration is calculated in the way that one body is treated as freely moving in space, while other bodies are set as fixed *** hydrodynamic force and moment are then applied into a numerical simulation model with some calibration coefficients being inserted. These coefficients are calibrated with the model test results. The simulation model built up this way can predict coupled responses with the similar accuracy as the model test and full scale measurement,and particularly generate multibody shielding effects. Site measured responses and the responses only resulted from from the simulation keep project management simultaneously to judge risks of each salvage stage, which are important for success of Sewol salvage.

关键词： salvage lifting barge coupled response numerical simulation model test site measurement

Tracking Registration Algorithm for Augmented Reality Based on Template Tracking

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International Journal of Automation and computing 2020年第2期17卷 257-266页

作者： Peng-Xia Cao Wen-Xin Li wei-ping Ma Lanzhou Institute of Physics China Academy of Space TechnologyLanzhou 730000China

Tracking registration is a key issue in augmented reality applications,particularly where there are no artificial identifier placed *** this paper,an efficient markerless tracking registration algorithm which combines the detector and the tracker is presented for the augmented reality *** capture the target images in real scenes as template images,use the random ferns classifier for target detection and solve the problem of reinitialization after tracking registration failures due to changes in ambient lighting or occlusion of *** the target has been successfully detected,the pyramid Lucas-Kanade(LK)optical flow tracker is used to track the detected target in real time to solve the problem of slow *** least median of squares(LMedS)method is used to adaptively calculate the homography matrix,and then the three-dimensional pose is estimated and the virtual object is rendered and *** results demonstrate that the algorithm is more accurate,faster and more robust.

关键词： Tracking registration augmented reality markerless random ferns Lucas-Kanade(LK)optical flow