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多沙河流悬移质含沙量预测方法探讨

水利技术监督 2025年第1期 155-157页

作者：邢晶尧辽宁省沈阳水文局辽宁沈阳110043

为提高多泥沙河流含沙量预测的适用性,文章采用队列回归模型,以辽宁地区多泥沙河流柳河为具体实例,结合柳河彰武站近20年含沙量实测数据,分析队列回归模型对多泥沙河流含沙量预测的适用性。结果表明,队列回归模型通过建立含沙量回归模型... 详细信息

为提高多泥沙河流含沙量预测的适用性,文章采用队列回归模型,以辽宁地区多泥沙河流柳河为具体实例,结合柳河彰武站近20年含沙量实测数据,分析队列回归模型对多泥沙河流含沙量预测的适用性。结果表明,队列回归模型通过建立含沙量回归模型,其含沙量预测误差总体在±20%以内,适合于多泥沙河流含沙量预测。

关键词：含沙量预测队列回归模型适用性分析多泥沙河流

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浑河橡胶坝调水冲沙原型试验分析

水利技术监督 2025年第1期 296-299页

作者：邢钧策辽宁省沈阳水文局辽宁沈阳110000

为降低橡胶坝长期运行淤积后对行洪安全的影响,文章采用原型观测方式对浑河各级橡胶坝下的调水冲沙进行分析,确定调水冲沙的最优方式。结果表明,采用逐级塌坝并结合上游水库放水方式下可有效降低橡胶坝泥沙淤积,从而保障浑河的行洪安全... 详细信息

为降低橡胶坝长期运行淤积后对行洪安全的影响,文章采用原型观测方式对浑河各级橡胶坝下的调水冲沙进行分析,确定调水冲沙的最优方式。结果表明,采用逐级塌坝并结合上游水库放水方式下可有效降低橡胶坝泥沙淤积,从而保障浑河的行洪安全。研究成果对于其他河流橡胶坝运行方式具有一定参考价值。

关键词：泥沙淤积调水冲沙原型观测试验浑河

Theoretical Study on the Stable Structures and Aromaticities for Pnictogen Dianionic Sb4^2-, Bi4^2-, and （SbBi）2^2- Clusters

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Chinese Journal of Chemical Physics 2009年第1期22卷 75-81页

作者： xing-bao Wang Xian-xing Chi School of Physics and Electronic Information Wenzhou University Wenzhou 325027 China

Through the theoretical calculation of structural optimization, vibrational frequencies and atomization energies with one method of density functional theory （B3LYP） and two post- Hartree-Fock approaches （MP2, CCSD（T））, several stable isomers for new three pnictogen dianionic Sb4^2-, Bi4^2-, and （SbBi）2^2- species were determined. For two homoatomic Sb4^2- and Bi4^2- species, there are three stable isomers： square （D4h）, roof-shaped （C2v-1）, and C2v-2 structure with the square isomer being the ground state. For the heteroatomic dian- ionic （SbBi）2^2- species, there are also three stable isomers： rhombus （D2h）, roof-shaped （C1）, and C2v structures with the rhombic isomer being the ground state. The calculated NICS values show that nucleus-independent chemical shifts （NICS） values of roof-shaped isomers for Sb4^2-, Bi4^2-, and （SbBi）2^2- species are all negative, consequently indicating that these roof-shaped isomers possess aromaticities. NICS values for the planar ring isomers are all positive, suggesting that these three planar ring isomers have antiaromatic characters. The aromaticity for the two stable roof-shaped and square isomers are preliminarily explained and discussed with MO analysis.

关键词： Pnictogen cluster Ab initio Aromaticity Nucleus-independent chemical shift

SIF-based fracture criterion for interface cracks

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Acta Mechanica Sinica 2016年第3期32卷 491-496页

作者： xing Ji School of Aerospace Engineering and Applied Mechanics Tongji University

The complex stress intensity factor K governing the stress field of an interface crack tip may be split into two parts, i.e.,■ and s^（-iε）, so that K = ■ s^（-iε）, s is a characteristic length and ε is the oscillatory index. ■ has the same dimension as the classical stress intensity factor and characterizes the interface crack tip field. That means a criterion for interface cracks may be formulated directly with■, as Irwin（ASME J. Appl. Mech. 24：361–364, 1957） did in 1957 for the classical fracture mechanics. Then, for an interface crack,it is demonstrated that the quasi Mode I and Mode II tip fields can be defined and distinguished from the coupled mode tip fields. Built upon SIF-based fracture criteria for quasi Mode I and Mode II, the stress intensity factor（SIF）-based fracture criterion for mixed mode interface cracks is proposed and validated against existing experimental results.

关键词： Interface crack Stress singularity Fracture criterion Stress intensity factor

Differential Evolution Based Receding Horizon Control for UAV Motion Planning in Dynamic Environments

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机器人 2013年第1期35卷 107-114页

作者： ZHANG xing School of Automation Beijing Institute of Technology Beijing 100081 China Key Laboratory of Complex System Intelligent Control and Decision Ministry of Education Beijing 100081 China Decision and Cognitive Sciences Research Centre Manchester Business School University of Manchester Manchester M15 6PB UK

This paper presents online motion planning for UAV(unmanned aerial vehicle) in complex threat field,including both static threats and moving threats,which can be formulated as a dynamic constrained optimal control *** horizon control(RHC) based on differential evolution(DE) algorithm is adopted.A location-predicting model of moving threats is established to assess the value of threat that UAV faces in *** flyable paths can be generated by the control inputs which are optimized by DE under the guidance of the objective *** results demonstrate that the proposed method not only generates smooth and flyable paths,but also enables UAV to avoid threats efficiently and arrive at destination safely.

关键词：无人机在线运动规划动态约束目标函数

Direct numerical simulation of Open Von Kármán Swirling Flow

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Journal of Hydrodynamics 2014年第2期26卷 165-177页

作者： xing Tao Department of Mechanical Engineering College of EngineeringUniversity of Idaho

Direct numerical simulations are used to investigate the Open Von Kfirmfin Swirling Flow, a new type of unsteady three-dimensional flow that is formed between two counter-rotating coaxial disks with an axial extraction enclosed by a cylinder chamber. Solution verification shows that monotonic convergence is achieved on three systematically refined grids for average pressure at the disk periphery with a small grid uncertainty at 3.5%. Effects of the rotational speeds and flow rates on the flow field are examined. When the disks are rotating at the lowest speed, ＋100 RPM, only circular vortices are formed regardless of the flow rates. When the disks are rotating at ＋300 RPM and ＋500 RPM, negative spiral vortex network is formed. The radial counterflow concept for such spiral vortex network is verified by examining various horizontal cuts and radial velocity component, which show radial outflows in two bands near the two disks and radial inflow in one band between them. Overall, the flow is similar to the Stewartson type flow but with significant differences for all three velocity components due to the axial suction at the upper disk center and gap between the disk periphery and chamber wall.

关键词： direct numerical simulation Open Von Kfirmfin flow swirling radial counterflow

A general framework for verification and validation of large eddy simulations

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Journal of Hydrodynamics 2015年第2期27卷 163-175页

作者： xing Tao Department of Mechanical Engineering College of EngineeringUniversity of Idaho

A general framework（methodology and procedures） for verification and validation（V＆V） of large eddy simulations in computational fluid dynamics（CFD） is derived based on two hypotheses. The framework allows for quantitative estimations of numerical error, modeling error, their coupling, and the associated uncertainties. To meet different needs of users based on their affordable computational cost, various large eddy simulation（LES） V＆V methods are proposed. These methods range from the most sophisticated seven equation estimator to the simplest one-grid estimator, which will be calibrated using factors of safety to achieve the objective reliability and confidence level. Evaluation, calibration and validation of various LES V＆V methods in this study will be performed using rigorous statistical analysis based on an extensive database. Identification of the error sources and magnitudes has the potential to improve existing or derive new LES models. Based on extensive parametric studies in the database, it is expected that guidelines for performing large eddy simulations that meet pre-specified quality and credibility criteria can be obtained. Extension of this framework to bubbly flow is also discussed.

关键词： framework verification and validation large eddy simulation(LES)

Runtime model based approach to IoT application development

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Frontiers of Computer Science 2015年第4期9卷 540-553页

作者： xing CHEN College of Mathematics and Computer Science Fuzhou University Fuzhou 350116 China Fujian Provincial Key Laboratory of Networking Computing and Intelligent Information Processing Fuzhou 350116 China Key Laboratory of High Confidence Software Technologies (Ministry of Education) Beijing 100871 China School of Electronics Engineering and Computer Science Peking University Beijing 100871 China

The internet of things （loT） attracts great interest in many application domains concerned with monitoring and ：ontrol of physical phenomena. However, application devel- opment is still one of the main hurdles to a wide adoption of IoT technology. Application development is done at a low level, very close to the operating system and requires pro- grammers to focus on low-level system issues. The under- lying APIs can be very complicated and the amount of data collected can be huge. This can be very hard to deal with as a developer. In this paper, we present a runtime model based approach to IoT application development. First, the manage- ability of sensor devices is abstracted as runtime models that are automatically connected with the corresponding systems. Second, a customized model is constructed according to a personalized application scenario and the synchronization be- tween the customized model and sensor device runtime mod- els is ensured through model transformation. Thus, all the application logic can be carried out by executing programs on the customized model. An experiment on a real-world ap- plication scenario demonstrates the feasibility, effectiveness, and benefits of the new approach to IoT application develop- ment.

关键词： IoT application development software architec-ture models at runtime

Soil Enzyme Activities under Agroforestry Systems in Northern Jiangsu Province

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Forestry Studies in China 2004年第2期6卷 21-26页

作者： WanFuxu chenping CollegeofForestryResourceandEnvironment NanjingForestryUniversityNanjing210037ER.China

The authors presented the enzyme characteristics of catalase, sucrase, urease and alkaline phosphatase under agroforestry systems in northern Jiangsu Province. The results show that soil enzyme activities reduce gradually from top to bottom layer of the soil profile, and the fluctuations of catalase and urease are smaller than those of sucrase and alkaline phosphatase. Soil enzyme activities differe significantly in different samples, and the order is arranged as poplar-crop intercropping segment (A, D) > paulownia-crop intercropping segment (B, C) > CK. Furthermore, soil enzyme activities increase with intercropping age. On the other hand, in the same plot, there are closer relationships between enzymes in the soil samples. Catalase, alkaline phosphatase and urease are negatively related, while alkaline phosphatase and urease are positively related (except in samples B and C). In addition, the enzyme activities have a close relationship with the fertilizers. Catalase is positively correlated with the soil pH value (r = 0.854, 0.804, 0.078 and 0.082, respectively), and is negatively correlated with total N (r = –0.201, –0.529, –0.221 and –0.821, respectively), total P (r = –0.143, –0.213, –0.362 and –0.751, respectively) and available P (r = –0.339, –0.351, –0.576, and –0.676, respectively). Sucrase, urease and alkaline phosphatase are negatively correlated with the pH value, while positively correlated with the other fertilizers (r 1). The authors suggest that enzyme activity will be a great potential as an indicator of soil quality.

关键词： catalase sucrase urease alkaline phosphatase intercropping