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Cloud Water Resource in North China in 2017 Simulated by the CMA-CPEFS Cloud Resolving Model:Validation and Quantification

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Journal of Meteorological Research 2022年第3期36卷 520-538页

作者： chao tan Miao CAI Yuquan ZHOU Weiguo LIU Zhijin HU CMA Key Laboratory for Cloud Physics Weather Modification CenterChina Meteorological Administration(CMA)Beijing 100081

Based on the concept of cloud water resource(CWR)and the cloud microphysical scheme developed by the Chinese Academy of Meteorological Sciences(CAMS),a coupled mesoscale and cloud-resolving model system is developed in the study for CWR numerical quantification(CWR-NQ)in North China for 2017.The results show that(1)the model system is stable and capable for performing 1-yr continuous simulation with a water budget error of less than 0.2%,which indicates a good water balance.(2)Compared with the observational data,it is confirmed that the simulating capability of the CWR-NQ approach is decent for the spatial distribution of yearly cumulative precipitation,daily precipitation intensity,yearly average spatial distribution of water vapor.(3)Compared with the CWR diagnostic quantification(CWR-DQ),the results from the CWR-NQ differ mainly in cloud condensation and cloud evaporation.However,the deviation of the net condensation(condensation minus evaporation)between the two methods is less than 1%.For other composition variables,such as water vapor advection,surface evaporation,precipitation,cloud condensation,and total atmospheric water substances,the relative differences between the CWR-NQ and the CWR-DQ are less than 5%.(4)The spatiotemporal features of the CWR in North China are also studied.The positive correlation between water vapor convergence and precipitation on monthly and seasonal scales,and the lag of precipitation relative to water vapor convergence on hourly and daily scales are analyzed in detail,indicating the significance of the state term on hourly and daily scales.The effects of different spatial scales on the state term,advection term,source-sink term,and total amount are analyzed.It is shown that the advective term varies greatly at different spatiotemporal scales,which leads to differences at different spatiotemporal scales in CWR and related characteristic quantities.

关键词： cloud water resource atmospheric moisture budget long-term continuous simulation model validation spatiotemporal characteristics

Defect repairing in two-dimensional transition metal dichalcogenides

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Frontiers of physics 2023年第5期18卷 47-64页

作者： Shiyan Zeng Fang Li chao tan Lei Yang Zegao Wang College of Materials Science and Engineering Sichuan UniversityChengdu 610065China

Atomically thin two-dimensional(2D)transition metal dichalcogenides(TMDCs)have stimulated enormous research interest due to rich phase structure,high theoretical carrier mobility and layer-dependent bandgap.In view of the close correlation between defects and properties in 2D TMDCs,more attentions have been paid on the defect engineering in recent years,however the mechanism is still unclear.Herein,we review the critical progress of defect engineering and provide an extensive way to modulate the properties depressed by defects.To insight into the defect engineering,we firstly introduce two common kinds of defects during the growth progress of TMDCs and the possible distribution of energy levels those defects could induce.Then,various methods to improve point defects and grain boundaries during the period of growth are discussed intensively,with the assistance of which more large-area TMDCs films can be obtained.Considering the defects in TMDCs are inevitable regardless of concentration,we also highlight strategies to heal the defects after growth.Through dry methods or wet methods,the chalcogen vacancies can be repaired and thus,the performance of electronic device would be significantly enhanced.Finally,we propose the challenges and prospective for defect engineering in 2D TMDCs materials to support the optimization of device and lead them to wide applied fields.

关键词： defect repairing two-dimensional transition metal dichalcogenides

Emerging MoS_(2)Wafer-Scale Technique for Integrated Circuits

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Nano-Micro Letters 2023年第3期15卷 129-170页

作者： Zimeng Ye chao tan Xiaolei Huang Yi Ouyang Lei Yang Zegao Wang Mingdong Dong College of Materials Science and Engineering Sichuan UniversityChengdu 610065People’s Republic of China State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi’an 710072People’s Republic of China Interdisciplinary Nanoscience Center Aarhus University8000 Aarhus CDenmark

As an outstanding representative of layered materials,molybdenum disulfide(MoS_(2))has excellent physical properties,such as high carrier mobility,stability,and abundance on earth.Moreover,its reasonable band gap and microelectronic compatible fabrication characteristics makes it the most promising candidate in future advanced integrated circuits such as logical electronics,flexible electronics,and focal-plane photodetector.However,to realize the all-aspects application of MoS_(2),the research on obtaining high-quality and large-area films need to be continuously explored to promote its industrialization.Although the MoS_(2)grain size has already improved from several micrometers to sub-millimeters,the high-quality growth of wafer-scale MoS_(2)is still of great challenge.Herein,this review mainly focuses on the evolution of MoS_(2)by including chemical vapor deposition,metal–organic chemical vapor deposition,physical vapor deposition,and thermal conversion technology methods.The state-of-the-art research on the growth and optimization mechanism,including nucleation,orientation,grain,and defect engineering,is systematically summarized.Then,this review summarizes the wafer-scale application of MoS_(2)in a transistor,inverter,electronics,and photodetectors.Finally,the current challenges and future perspectives are outlined for the wafer-scale growth and application of MoS_(2).

关键词： Wafer-scale growth Molybdenum disulfide Gas deposition Integrated circuits

Diagnostic Quantification of the Cloud Water Resource in China during 2000–2019

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Journal of Meteorological Research 2022年第2期36卷 292-310页

作者： Miao CAI Yuquan ZHOU Jianzhao LIU Yahui tanG chao tan Junjie ZHAO Jianjun OU CMA Key Laboratory for Cloud Physics Weather Modification CenterChina Meteorological Administration(CMA)Beijing 100081 Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102 University of Chinese Academy of Sciences Beijing 100049 Meteorological Disaster Prevention Technology Center of Shanxi Taiyuan 030032 Shanghai By Weather Technology Co. Shanghai 201306

By using the diagnostic quantification method for cloud water resource(CWR),the three-dimensional(3D)cloud fields of 1°×1°resolution during 2000-2019 in China are firstly obtained based on the NCEP reanalysis data and related satellite data.Then,combined with the Global Precipitation Climatology Project(GPCP)products,a 1°×1°gridded CWR dataset of China in recent 20 years is established.On this basis,the monthly and annual CWR and related variables in China and its six weather modification operation sub-regions are obtained,and the CWR characteristics in different regions are analyzed finally.The results show that in the past 20 years,the annual total amount of atmospheric hydrometeors(GM_(h))and water vapor(GM_(v))in the Chinese mainland are about 838.1 and 3835.9 mm,respectively.After deducting the annual mean precipitation of China(P_(s),661.7 mm),the annual CWR is about 176.4 mm.Among the six sub-regions,the southeast region has the largest amount of cloud condensation(C_(vh))and precipitation,leading to the largest GM_(h) and CWR there.In contrast,the annual P_(s),GM_(h),and CWR are all the least in the northwest region.Furthermore,the monthly and interannual variation trends of P_(s),C_(vh),and GM_(h) in different regions are identical,and the evolution characteristics of CWR are also consistent with the hydrometeor inflow(Q_(hi)).For the north,northwest,and northeast regions,in spring and autumn the precipitation efficiency of hydrometeors(PEh)is not high(20%-60%),the renewal time of hydrometeors(RT_(h))is relatively long(5-25 h),and GM_(h) is relatively high.Therefore,there is great potential for the development of CWR through artificial precipitation enhancement(APE).For the central region,spring,autumn,and winter are suitable seasons for CWR development.For the southeast and southwest regions,P_(s) and PE_(h) in summer are so high that the development of CWR should be avoided.For different spatial scales,there are significant differences in the characteristics of CWR.

关键词： cloud water resource(CWR) diagnostic quantification weather modification regions monthly and annual variation development characteristics

基于环形电导传感器的气液两相流流型识别与过程参数测量

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化工进展 2024年第2期43卷 637-648页

作者：史雪薇谭超董峰天津大学电气自动化与信息工程学院天津市过程检测与控制重点实验室天津300072

针对水平管道气液两相流,提出一种仅采用单模态电导传感器实现流型准确辨识和流速、含率准确测量的综合性测试方法。首先,采用由6个电极环组成的电导传感器在线获取不同流动状态下含率和速度的相关信息。其次,在信号波动分析基础上,揭... 详细信息

针对水平管道气液两相流,提出一种仅采用单模态电导传感器实现流型准确辨识和流速、含率准确测量的综合性测试方法。首先,采用由6个电极环组成的电导传感器在线获取不同流动状态下含率和速度的相关信息。其次,在信号波动分析基础上,揭示了不同流型下的流动特性,进而提取了量纲为1电压序列的均值和方差及互相关速度作为流型表征的特征向量;采用适用于小样本的支持向量机方法,以“一对一”策略构建了15个以径向基为核函数的二分类器用于分层流、波状流、泡状流、塞状流、弹状流和环状流的划分,采用交叉验证方法对模型参数进行了优化选取,实现了6种流型的准确识别,平均识别率为93.1%。最后,在流型划分基础上,针对性地提出利用量纲为1电压和互相关速度获取不同流型下分相含率和平均速度的计算模型,并与入口参考含率和参考流速进行了对比。动态实验表明,含水率和含气率的均方根误差分别为2.56%和2.73%,平均流速的均方根误差为0.69m/s。

关键词：气液两相流仪器仪表流速含率测量流型识别

In situ preparation of Ag@AgCl/Bio-veins composites and their photocatalytic activity and recyclability

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Frontiers of Chemical Science and Engineering 2023年第7期17卷 906-917页

作者： Min Zou chao tan Zhengqiu Yuan Ming Wu Jian Jian Lei Zhang Yan Zhang Zhou Ma Hu Zhou School of Resource&Environment and Safety Engineering Hunan University of Science and TechnologyXiangtan 411201China Key Laboratory of Theoretical Organic Chemistry and Functional Molecules Ministry of EducationFunctional Film Materials Engineering Research Center of Hunan ProvinceHunan Provincial Key Laboratory of Advanced Materials for New Energy Storage and ConversionSchool of Chemistry and Chemical EngineeringHunan University of Science and TechnologyXiangtan 411201China School of Information and Electrical Engineering Hunan University of Science and TechnologyXiangtan 411201China

The industrial application of nano-photocatalysts in wastewater treatment has been severely restricted for a long time due to their difficult separation,poor reusability,and low efficiency.In this work,a facile strategy was proposed to enhance the photocatalytic activity and recovery performance of Ag@AgCl nanocatalysts.Biological veins(Bio-veins)with a unique 3D porous construction were used as carriers for the in-situ growth of Ag@AgCl nanoparticles.Scanning electron microscopy results showed that the Ag@AgCl nanoparticles were uniformly loaded on the surface and interior of the Bio-veins,and the size of the Ag@AgCl nanoparticles immobilized on the Bio-veins(50–300 nm)was significantly smaller than Ag@AgCl obtained by the co-precipitation method(1–3μm).The Bio-veins played a vital role in the photocatalysis reaction system.The degradation efficiency of the Ag@AgCl/Bio-veins(CI4)was up to 3.50 times as high as pure Ag@AgCl.Furthermore,the composites also exhibited excellent recyclability and stability under both visible and solar light.This work provided a suitable strategy for nano-photocatalysts for practical application and may also offer new possibilities for the high-value utilization of biomass materials.

关键词： Ag@AgCl biological veins photocatalytic activity recyclability

LKLR: A Local tangent Space-Alignment Kernel Least-Squares Regression Algorithm

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Tsinghua Science and Technology 2019年第4期24卷 389-399页

作者： chao tan Genlin Ji the School of Computer Science and Engineering Southeast University the School of Computer Science and Technology Nanjing Normal University the School of Computer Science and Technology Nanjing Normal University

In the fields of machine learning and data mining, label learning is a nascent area of research, and within this paradigm, there is much room for improving multi-label manifold learning algorithms for high-dimensional data. Thus far, researchers have experimented with mapping relationships from the feature space to the traditional logical label space(using neighbors in the label space, for example, to predict logical label vectors from the feature space's manifold structure). Here we combine the feature manifold's and label space's local topological structures to reconstruct the label manifold. To achieve this, we use a nonlinear manifold learning algorithm to transform the local topological structure from the feature space to the label space. Our algorithm adopts a regularized leastsquares kernel method to realize the reconstruction process, employing an optimization function to find the best solution. Extensive experiments show that our algorithm significantly improves multi-label manifold learning in terms of learning accuracy and time complexity.

关键词： multi-label manifold learning local topological structure regularized least squares kernel method

焊接残余应力对高强钢点焊接头裂纹扩展及疲劳性能的影响

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机械强度 2024年第2期46卷 439-445页

作者：罗家元李鑫谭超重庆交通大学机电与车辆工程学院重庆400074

点焊接头因高度应力集中,极易于熔核边缘萌生疲劳裂纹,点焊产生的残余应力会影响其扩展。为探究点焊残余应力对疲劳裂纹扩展的影响规律,建立DP600高强钢点焊接头三维裂纹有限元仿真模型。基于热-弹塑性理论求解点焊残余应力场,在此基础... 详细信息

点焊接头因高度应力集中,极易于熔核边缘萌生疲劳裂纹,点焊产生的残余应力会影响其扩展。为探究点焊残余应力对疲劳裂纹扩展的影响规律,建立DP600高强钢点焊接头三维裂纹有限元仿真模型。基于热-弹塑性理论求解点焊残余应力场,在此基础上计算有无残余应力时折线裂纹的局部应力强度因子(Stress Intensity Factor,SIF)解,通过分析两种条件下裂纹最深点局部SIF随裂纹深度比变化的曲线,研究点焊残余应力对折线裂纹扩展的影响规律;基于断裂力学理论,采用改进的双参数模型预测有无残余应力时的疲劳寿命。结果表明,点焊残余应力使局部SIF显著提高,且随着裂纹深度比的增加,残余应力对其的影响程度也增加;考虑残余应力后裂纹整体扩展趋势不变但扩展速率显著增加,疲劳寿命由35616次下降至12564次。

关键词：点焊残余应力折线裂纹应力强度因子疲劳寿命

一种基于中心频率匹配的超声流量计ToF算法

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工程热物理学报 2024年第2期45卷 460-464页

作者：谭超江逸舟鲍勇董峰天津市过程检测与控制重点实验室天津大学电气自动化与信息工程学院天津300072

随着工业领域的不断发展,对流量的高精度、在线检测的需求也愈发迫切。以氢气循环泵为例,在小管径下,对氢气的流量监测精度直接影响循环泵的性能。超声流量计凭借其高精度、非侵入、无压损等优点,一直是流量检测领域关注的重点,可以满... 详细信息

随着工业领域的不断发展,对流量的高精度、在线检测的需求也愈发迫切。以氢气循环泵为例,在小管径下,对氢气的流量监测精度直接影响循环泵的性能。超声流量计凭借其高精度、非侵入、无压损等优点,一直是流量检测领域关注的重点,可以满足不同场景下的测量需求。渡越时间提取算法是超声流量计设计的关键环节,对流量测量精度有着十分重要的影响。渡越时间的精度和鲁棒性直接影响着超声流量计流量测量的结果。本文针对氢气循环泵的测量场景,提出了一种基于探头中心频率匹配的ToF算法,并采用了仿真软件来进行模拟实验。结果显示,相比传统的超声渡越时间算法,标准差分别是其他两种算法的5.21%和32.14%,而误差则分别是二者的15.41%和36.43%。

关键词：超声流量计中心频率渡越时间