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Interaction of aerodynamic roughness length and windflow conditions and its parameterization over vegetation surface

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Chinese Science Bulletin 2012年第13期57卷 1559-1567页

作者： ZHANG Qiang ZENG Jian yao tong Institute of Arid Meteorology China Meteorological Administration(CMA)Key Laboratory of Arid Climatic Change and Disaster Reduction of Gansu ProvinceKey Open Laboratory of Arid Climatic Change and Disaster Reduction of CMALanzhou 730020China Meteorological Bureau of Gansu Lanzhou 730020China Beijing Meteorological Bureau Beijing 100089China College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China

Surface aerodynamic roughness length is usually taken as a constant. In fact, it displays a remarkable dynamic change over underlying vegetation surfaces, because of the coupling of land surface roughness elements and windflow conditions. Current international research on this dynamic change and associated mechanisms is very limited. Using observations from different underlying surfaces (including forest, farmland and grassland) provided by a northern China coordinated observation test, the variation of aerodynamic roughness length, along with wind speed and friction velocity, is analyzed. We introduce two relationship fits, between aerodynamic roughness length and wind speed u, and dynamic variable u2/u*. Results show that aerodynamic roughness length has a clear dynamic change, and has complicated interactions with near-surface windflow. Further, the relationship fits between aerodynamic roughness length, u and u2/u*, are not only related to the roughness properties of the underlying vegetation surface (e.g. plant height), but also to plant dynamic response characteristics (e.g. flexibility). Aerodynamic roughness length decreases with increasing wind speed, because near-surface windflow conditions can change both plant roughness properties and airflow. However, the change of aerodynamic roughness length with friction velocity is complicated, and its sensitivities and transition points significantly depend on vegetation type. For underlying surfaces of forest and corn, with relatively substantial vegetative cover, roughness length correlates well with wind speed. For a surface with short vegetative cover, like natural lawn, the correlation is low. However, for all of the three vegetative surfaces, there is a close relation between roughness length and u2/u*, and their coefficients of fit from testing essentially represent the plant height and flexibility of different vegetation types. The test results also indicate that the parameterized relationships of roughness

关键词：粗糙度长度空气动力学表面粗糙度植被类型相互作用观测试验动态变化动态响应特性

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A two‐branch network with pyramid‐based local and spatial attention global feature learning for vehicle re‐identification

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CAAI Transactions on Intelligence Technology 2021年第1期6卷 46-54页

作者： Jucheng Yang Di Xing Zhiqiang Hu tong yao College of Artificial Intelligence Tianjin University of Science and TechnologyTianjinPeople’s Republic of China

In recent years,vehicle re‐identification has attracted more and more *** to learn the discriminative information from multi‐view vehicle images becomes one of the challenging problems in vehicle re‐identification *** example,when the viewpoint of the image changes,the features extracted from one image may be lost in another image.A two‐branch network with pyramid‐based local and spatial attention global feature learning(PSA)is proposed for vehicle re‐identification to solve this ***,one branch learns local features at different scales by building pyramid from coarse to fine and the other branch learns attentive global features by using spatial attention ***,pooling operation by using global maximum pooling(GMP)for local features and global average pooling(GAP)for global feature is ***,local feature vectors and global feature vector extracted from the last pooling layer,respectively,are employed for identity re‐*** experimental results demonstrate that the proposed method achieves state‐of‐the‐art results on the VeRi‐776 dataset and VehicleID dataset.

关键词： branch pyramid learning

A Mechanism Study of a Novel Acid-Activatable Michael-Type Fluorescent Probe for Thiols

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Chinese Journal of Chemical Physics 2015年第3期28卷 277-287,I0001页

作者： yao tong Chun-guang Dai Yi Ren Shi-wei Luo Department of Chemistry University of Science and Technology of China Hefei 230026 China College of Chemistry and State Key Laboratory of Biotherapy Sichuan University Chengdu 610064 China

A Michael addition is usually taken as a base-catalysed reaction. However, our synthesized 2-（quinolin-2-ylmethylene） malonic acid （QMA） as a Michael-type thiol fluorescent probe is acid-active in its sensing reaction. In this work, based on theoretic calculation and experimental study on 7-hydroxy-2-（quinolin-2-ylmethylene） malonic acid, we demonstrated that QMA as a Michael acceptor is acid-activatable, i.e., it works only in solutions at pH〈7, and the lower the pH of solutions is, the higher reactivity QMA has. In alkaline solution, the malonate QMA[-2H＋]2- cannot react with both RSand RSH. In contrast, 2-（quinolin-2- ylmethylene） malonic ester （QME）, the ester of QMA, reveal a contrary pH effect on its sensing reaction, that is, it can sense thiols in alkaline solutions but not in acidic solutions, like a normal base-catalysed Michael addition. The values of activation enthalpies from theoretic calculation support the above sensing behavior of two probes under different pH conditions. In acidic solutions, the protonated QMA is more highly reactive towards electrophilic attack over its other ionized states in neutral and alkaline solutions, and so can react with lowly reactive RSH. In contrast, there is a big energy barrier in the interaction of QME with RSH （acidic solutions）, and the reaction of QME with the highly reactive nucleophile RS- is a low activation energy process （in alkaline solutions）. Theoretic calculation reveals that the sensing reaction of QMA undergoes a 1,4-addition process with neutral thiols （RSH）, and a 1,2-addition pathway for the sensing reaction of QME with RS-. Therefore, the sensing reaction of QMA is an acid-catalysed Michael addition via a 1,4-addition, and a normal base-catalysed Michael addition via a 1,2-addition.

关键词： Fluorescent probe Thiols Michael addition DFT calculation Transitionstate Activation enthalpy

Strength-toughness improvement of 13Cr4NiMo martensitic stainless steel with thermal cyclic heat treatment

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Journal of Iron and Steel Research International 2023年第8期30卷 1499-1510页

作者： Jie Xiong yao-lin tong Jie-long Peng Sheng-hua Zhang State Key Laboratory of Featured Metal Materials and Life-Cycle Safety for Composite Structures MOE Key Laboratory of New Processing Technology for Nonferrous Metals and Materialsand School of ResourcesEnvironment and MaterialsGuangxi UniversityNanning 530004GuangxiChina Key Laboratory of High Performance Structural Materials and Thermo-Surface Processing Education Department of Guangxi Zhuang Autonomous RegionGuangxi UniversityNanning 530004GuangxiChina

To improve the strength-toughness of 13Cr4NiMo martensitic stainless steel(13-4MSS),a thermal cyclic heat treatment(TCHT)combined with the advantage of tempering was *** microstructures were characterized by scanning electron microscopy,X-ray diffraction and electron backscattered diffraction,and the mechanical behaviors in terms of tensile properties and impact toughness were analyzed in correlation with microstructural *** was found that grains and the martensitic matrix were refined by TCHT through the cyclic quenching transformation and austenite recrystallization,which was conducive to more nucleation quantity of reversed austenite during ***-sphericalcap nucleation model was used to explain the effect of refined grains of TCHT on the nucleation of reversed *** refinement by TCHT improved the brittle fracture stress to reduce the ductile-brittle transition temperature and thus improved the cryogenic impact toughness of *** austenite distributed at the martensitic lath boundary enhances the crack arrest performance and increases the britle fracture *** is concluded that reasonable TCHT plus tempering process significantly improves the strength-toughness of 13-4MSS,reflecting the comprehensive effect of grain refinement and reversed austenite.

关键词： Strength-Toughness 13Cr4NiMo martensitic stainless steel Thermal cyclic heat treatment Grain refinement Reversed austenite

Ice-and-snow tourism and its sustainable development in China: A new perspective of poverty alleviation

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Advances in Climate Change Research 2021年第6期12卷 881-893页

作者： AN Hong-Min XIAO Cun-De tong yao FAN Jie State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing100875China Climate Change Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing100029China Yingkou Meteorological Bureau Yingkou110001China Key Laboratory of Regional Sustainable Development Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing100101China

The development of ice-and-snow tourism (IST) has great potential for poverty alleviation and is of great significance for promoting the sustainable development of alpine areas. However, little attention has been given to evaluating the suitability and potential of ice-and-snow tourism in poverty-stricken areas. Taking 832 poverty-stricken counties in China as samples, this study proposed an integrity suitability index (ISI) based on natural and socioeconomic factors to evaluate the suitability and potential of developing ice-and-snow tourism in poverty-stricken counties. The results showed that there are significant differences between the spatial distributions of the suitability of glacier- and ski-related tourism. The former is mainly distributed in the Qinghai‒Tibet Plateau, while the latter is distributed in low-altitude mountainous areas. Additionally, 36.0% of the total number of poverty-stricken counties have the potential to match medium-to high-level ISIs of ice-and-snow tourism, of which 2.5%, 32.9% and 0.2% are suitable for glacier excursions, ski sports and both, respectively. Furthermore, climate change and environmental protection are the main constraints on the development of ice-and-snow tourism and corresponding development strategies are proposed. This study can provide references for scientific planning and policy making regarding the sustainable development in poverty-stricken areas.

关键词： Ice-and-snow tourism Poverty alleviation Cryosphere service Sustainable development Ski tourism Glacier tourism

Effectiveness and safety of herbal medicines in the treatment of irritable bowel syndrome:A systematic review

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World Journal of Gastroenterology 2008年第3期14卷 454-462页

作者： Jun Shi yao tong Jian-Gang Shen Hai-Xia Li Department of Traditional Chinese Medicine and Western Medicine Liyuan Hospital TongJi Medical College HuaZhongUniversity of Sciences and Technology. Wuhan 430077 HebeiProvince China School of Chinese Medicine University of Hong Kong 10 Sassoon Road HongKong China

AIM： To explore the efficacy and safety of herba medicines （HM） in the treatment of irritable bowe syndrome （IBS）. METHODS： A computer-based as well as manual literature search was performed. We reviewed randomized controlled trials on the treatment of IBS with and without HM. RESULTS： A total of 22 studies with 25 HMs met the inclusion criteria. Four of these studies were of good quality, while the remaining 18 studies involving 17 Chinese herbal medicine （CHM） formulas were of poor quality. Eight of these reports using 9 HMs showed global improvement of IBS symptoms, 4 studies with 3 HMs were efficacious in diarrhea-predominant IBS, and 2 studies with 2 HMs showed improvement in constipation- predominant IBS. Out of a total of 1279 patients, 15 adverse events in 47 subjects were reported with HM. No serious adverse events or abnormal laboratory tests were observed. The incidence of the adverse events was low （2.97%; 95% CI： 2.04%-3.90%）. CONCLUSION： Herbal medicines have therapeutic benefit in IBS, and adverse events are seldom reported in literature. Nevertheless, herbal medicines should be used with caution. It is necessary to conduct rigorous, well-designed clinical trials to evaluate their effectiveness and safety in the treatment of IBS.

关键词： Irritable bowel syndrome Herbal medicine Systematic review

Camera-Radar Fusion Sensing System Based on Multi-Layer Perceptron

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Journal of Shanghai Jiaotong university(Science) 2021年第5期26卷 561-568页

作者： yao tong WANG Chunxiang QIAN Yeqiang Department of Automation Shanghai Jiao Tong UniversityShanghai 200240China University of Michigan-Shanghai Jiao tong University Joint Institute Shanghai Jiao Tong UniversityShanghai 200240China

Environmental perception is a key technology for autonomous *** to the limitations of a single sensor,multiple sensors are often used in practical ***,multi-sensor fusion faces some problems,such as the choice of sensors and fusion *** solve these issues,we proposed a machine learning-based fusion sensing system that uses a camera and radar,and that can be used in intelligent ***,the object detection algorithm is used to detect the image obtained by the camera;in sequence,the radar data is preprocessed,coordinate transformation is performed,and a multi-layer perceptron model for correlating the camera detection results with the radar data is *** proposed fusion sensing system was verified by comparative experiments in a real-world *** experimental results show that the system can effectively integrate camera and radar data results,and obtain accurate and comprehensive object information in front of intelligent vehicles.

关键词： intelligent vehicle environmental perception system sensor fusion multi-layer perceptron

Synthesis and Crystal Structure of 4-(4-Bromophenyl)- 3,4-dihydro-6-methyl quinolin-2(1H)-one

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Chinese Journal of Structural Chemistry 2007年第5期26卷 533-536页

作者： YU Chen-Xia ZHU Xiao-tong yao Chang-Sheng TU Shu-Jiang Department of Chemistry Xuzhou Normal University Xuzhou 221116 China Key Laboratory of Biotechnology for Medical Plants of Jiangsu Province Xuzhou 221116 China

The title compound （C16H14BrNO） has been synthesized by the reaction of p-tolylamine, Meldrum’s acid and 4-bromo-benzaldehyde, and its structure was characterized by IR, 1H NMR and X-ray single-crystal diffraction. The crystal belongs to monoclinic, space group P21/n with a = 7.6850（11）, b = 8.3004（11）, c = 21.301（3）A, β = 95.110（2）°, V = 1353.4（3） A^3, Mr = 316.19, Z = 4, Dc = 1.552 g/cm^3, μ（MoKα） = 3.028 mm-1, F（000） = 640, the final R = 0.0345 and wR = 0.0768. X-ray analysis reveals that the atoms of C（1）, C（2）, C（3）, C（4）, C（5） and N（1） form a six-membered ring of boat conformation.

关键词： quinoline crystal structure

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ZnO induced self-crystallization of CsPb(Br/I)_(3) nanocrystal glasses with improved stability for backlight display application

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Journal of Materials Science & Technology 2022年第26期121卷 140-147页

作者： Qin Wang yao tong Meiting Yang Hangtao Ye Xiaojuan Liang Xin Wang Weidong Xiang College of Life and Environmental Science Wenzhou UniversityWenzhou 325035China College of Chemistry and Materials Engineering Wenzhou UniversityWenzhou 325035China College of Materials and Environmental Engineering Hangzhou Dianzi UniversityHangzhou 310012China

In the current situation of energy shortages,saving energy and reducing consumption are undoubtedly valid methods to relieve the pressure on ***_(3)(X=Cl,Br,and I)perovskites as star inorganic materials have drawn growing attention owing to their unique properties,making them suitable for applications such as light-emitting diodes(LEDs),solar cells,photodetectors,or *** work presents zinc oxide(ZnO)induced self-crystallized CsPb(Br/I)_(3) perovskite with a 26%photoluminescence quantum yield(PLQY)prepared by the traditional melt-quenching ***,the full width at half maximum(FWHM)(34–44 nm)can be regulated by the ZnO *** addition,as a downconverter,CsPb(Br/I)_(3) perovskite nanocrystals(NCs)realize a bright red backlight that covers≈94%Rec.2020 standards in the CIE 1931 color space and 126%of National Television System Committee(NTSC).This finding undoubtedly confirms an effective path for fabricating perovskite materials in a green,low-cost,and time-saving way,enriching the knowledge of glass crystallization mechanisms and promoting their applications in wide color gamut backlights.

关键词： Perovskite glass Self-crystallization Backlight display

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