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Risk analysis for clustered check dams due to heavy rainfall

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International Journal of Sediment Research 2021年第2期36卷 291-305页

作者： Zuyu Chen Xieping Huang Shu Yu Wei Cao Weiqin Dang yangqiang wang Institute of Geotechnical Engineering Zhejiang University Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources and Hydropower Research Suide Experimental Station for Soil and Water Conservation Yellow River Conservancy Commission Department of Hydraulic Engineering Tsinghua University

Check dams are commonly constructed around the world for alleviating soil erosion and preventing sedimentation of downstream rivers and reservoirs. Check dams are more vulnerable to failure due to their less stringent flood control standards compared to other dams. Determining the critical precipitation that will result in overtopping of a dam is a useful approach to assessing the risk of failure on a probabilistic basis and for providing early warning in case of an emergency. However, many check dams are built in groups, spreading in several tributaries in cascade forms, comprising a complex *** the critical precipitation for dam overtopping requires a knowledge of its upstream dams on whether they survived or were overtopped during the same storm, while these upstream dams in turn need the information for their upstream dams. The current paper presents an approach of decomposing the dam cluster into(1) the heading dam,(2) border dams, and(3) intermediate dams. The algorithm begins with the border dams that have no upstream dams and proceeds with upgraded maps without the previous border dams until all the dams have been checked. It is believed that this approach is applicable for small-scale check dam systems where the time lag of flood routing can be neglected. As a pilot study, the current paper presents the analytical results for the wangmaogou Check Dam System that has 22 dams connected in series and parallel. The algorithm clearly identified 7 surviving dams, with the remaining ones being overtopped for a storm of 179.6 mm in 12 h, which is associated with a return period of one in 200 years.

关键词： Risk analysis Check dam Critical precipitation Cascade dams

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地基承载力深度和宽度修正系数分析

清华大学学报（自然科学版） 2023年第11期63卷 1897-1908页

作者：介玉新傅志斌王杨强殷常运清华大学水沙科学与水利水电工程国家重点实验室北京100084 建设综合勘察研究设计院有限公司北京100007

在大面积人工填土的地基承载力计算中,中国现行《建筑地基基础设计规范》(以下简称《规范》)不考虑对基础宽度的修正,得到的地基承载力偏小,对工程安全有利,但在一些情况下却不够经济。该文对这一问题进行探讨,分析了地基承载力的定义... 详细信息

在大面积人工填土的地基承载力计算中,中国现行《建筑地基基础设计规范》(以下简称《规范》)不考虑对基础宽度的修正,得到的地基承载力偏小,对工程安全有利,但在一些情况下却不够经济。该文对这一问题进行探讨,分析了地基承载力的定义、度量方法、相关理论原理和容许承载力的取值方法,探讨并推测了此前在人工填土、软弱下卧层等地基承载力修正系数选择上的可能依据。考虑到当前施工和监测技术相较于早期规范制定时已有很大进步,认为在满足一定条件下可考虑修正地基承载力宽度,并且可适当提高现有的深度和宽度修正系数取值。

关键词：地基极限承载力容许承载力深度修正系数宽度修正系数

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完整结肠系膜切除术治疗右半结肠癌的疗效

中国卫生标准管理 2020年第23期11卷 91-94页

作者：王洋强福建医科大学附属泉州第一医院胃肠外科福建泉州362000

目的分析完整结肠系膜切除术(complete mesocolic excision,CME)治疗右半结肠癌的临床效果。方法选取2017年1月—2018年3月在本院治疗的79例右半结肠癌患者临床资料实施回顾性分析,以上对象按照手术方式分组,分为观察组(n=49)和对照组(n... 详细信息

目的分析完整结肠系膜切除术(complete mesocolic excision,CME)治疗右半结肠癌的临床效果。方法选取2017年1月—2018年3月在本院治疗的79例右半结肠癌患者临床资料实施回顾性分析,以上对象按照手术方式分组,分为观察组(n=49)和对照组(n=30),患者分别行CME和腹腔镜结肠癌根治术进行治疗。观察并比较不同手术方式患者的各项手术治疗指标、并发症发生情况、复发率和死亡率。结果两组患者的手术指标比较,其中的手术时间比较差异无统计学意义(P> 0.05);但术中出血量、术后引流量、术后排气时间及总淋巴结清扫个数等指标,观察组患者均较对照组有明显优势,比较差异均有统计学意义(P <0.05);两组患者的术后恢复效果比较,其中术后并发症发生率、复发率和死亡率,观察组患者均较对照组有明显优势,组间比较差异均有统计学意义(P <0.05)。结论 CME治疗右半结肠癌,能够有效改善患者的手术治疗指标,并能够降低患者术后的并发症率、复发率和死亡发生率,可显著改善患者的预后效果。

关键词：完整结肠系膜切除术右半结肠癌治疗效果手术指标并发症复发率死亡率

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腹腔镜辅助远端胃癌根治手术的疗效观察

中国卫生标准管理 2020年第22期11卷 96-98页

作者：王洋强福建省泉州市第一医院胃肠外科福建泉州362000

目的研究腹腔镜辅助远端胃癌根治与传统开腹远端胃癌根治手术的临床疗效。方法回顾性分析2016年1月—2018年12月在我院治疗的80例II期、III期胃癌患者,其中,开腹组25例,使用传统开腹远端胃癌根治手术,腔镜组55例,使用腹腔镜辅助远端胃... 详细信息

目的研究腹腔镜辅助远端胃癌根治与传统开腹远端胃癌根治手术的临床疗效。方法回顾性分析2016年1月—2018年12月在我院治疗的80例II期、III期胃癌患者,其中,开腹组25例,使用传统开腹远端胃癌根治手术,腔镜组55例,使用腹腔镜辅助远端胃癌手术,对比两组患者术中及术后的相关指标。结果腔镜组与开腹组在手术时间、淋巴结清扫数目、远切缘及近切缘长度、1年生存率上差异无统计学意义(P>0.05);腔镜组在手术出血量、首次下床时间和首次肛门排气排便时间方面则腔镜组优于开腹组,差异具有统计学意义(P<0.05)。结论腹腔镜辅助远端胃癌根治手术和传统开腹远端胃癌根治手术相比较,腹腔镜辅助远端胃癌根治手术疗效更好,能够有效减少肿瘤复发。

关键词：腹腔镜临床疗效肿瘤复发推广价值远端胃癌胃癌根治手术

The reformation of catalyst:From a trial-and-error synthesis to rational design

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Nano Research 2024年第4期17卷 3261-3301页

作者： Ligang wang Jiabin Wu Shunwu wang Huan Liu Yao wang Dingsheng wang Department of Chemistry Tsinghua UniversityBeijing 100084China

The appropriate catalysts can accelerate the reaction rate and effectively boost the efficient conversion of various molecules,which is of great importance in the study of chemistry,chemical industry,energy,materials and environmental ***,efficient,environmentally friendly,and easy to operate synthesis methods have been used to prepare various types of *** previous studies have reported the synthesis and characterization of the aforementioned catalysts,more still remain in trial and error methods,without in-depth consideration and improvement of traditional synthesis ***,we comprehensively summarize and compare the preparation methods of the trial-and-error synthesis strategy,structure–activity relationships and density functional theory(DFT)guided catalysts rational design for nanomaterials and atomically dispersed *** also discuss in detail the utilization of the nanomaterials and single atom catalysts for converting small molecules(H_(2)O,O_(2),CO_(2),N_(2),etc.)into value-added products driven by electrocatalysis,photocatalysis,and ***,the challenges and outlooks of mass preparation and production of efficient and green catalysts through conventional trial and error synthesis and DFT theory are featured in accordance with its current development.

关键词： trial-and-error synthesis structure–activity relationships density functional theory(DFT)guidance nanomaterials atomically dispersed catalysts

Numerical Analysis of PRISM-PY Calculations for Hard-and Soft-Core Generic Polymer Models

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Chinese Journal of Polymer Science 2024年第4期42卷 532-543页

作者： Qiang wang Department of Chemical and Biological Engineering Colorado State University1370 Campus DeliveryFort CollinsCO80523-1370USA

Generic polymer models capturing the chain connectivity and excluded-volume interactions between polymer segments can be classified, according to whether or not the 3D integral of the latter diverges, into hard- and soft-core models. Taking homogeneous systems of compressible homopolymer melts (or equivalently homopolymer solutions in an implicit, good solvent) in the continuum as an example, we recently compared the correlation effects on the structural and thermodynamic properties of the hard- and soft-core models given by the polymer reference interaction site model (PRISM) theory with the Percus-Yevick (PY) closure (Polymers 2023, 15, 1180). Here we analyzed in detail the numerical errors and behavior of the interchain pair correlation functions (PCFs) given by the PRISM-PY calculations of these models using an efficient numerical approach that we proposed. Our numerical approach has the least number of independent variables to be iteratively solved, analytically treats the discontinuities caused by the non-bonded pair potential (such as that of the hard spheres) and takes only the inverse Fourier transform of the interchain indirect PCF between polymer segments (which is continuous and decays towards 0 with increasing wavenumber much faster than both the interchain direct and total PCFs), and is essential for us to accurately solve the PRISM-PY theory for chain length N as large as 106. To capture the correlation-hole effect, the real-space cut-off in the PRISM calculations should be proportional to the square root of N.

关键词： Generic polymer models Soft potentials Polymer reference interaction site model theory

Linear-Quadratic Pareto Cooperative Game for Mean-Field Backward Stochastic System

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Journal of Systems Science & Complexity 2024年第3期37卷 947-964页

作者： wang Yu School of Control Science and Engineering Shandong UniversityJinan 250061China

This paper focuses on a Pareto cooperative differential game with a linear mean-field backward stochastic system and a quadratic form cost functional. Based on a weighted sum optimality method, the Pareto game is equivalently converted to an optimal control problem. In the first place,the feedback form of Pareto optimal strategy is derived by virtue of decoupling technology, which is represented by four Riccati equations, a mean-field forward stochastic differential equation(MF-FSDE),and a mean-field backward stochastic differential equation(MF-BSDE). In addition, the corresponding Pareto optimal solution is further obtained. Finally, the author solves a problem in mathematical finance to illustrate the application of the theoretical results.

关键词： Backward stochastic differential equation linear-quadratic control mean-field Pareto optimality

A multi-source information fusion layer counting method for penetration fuze based on TCN-LSTM

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Defence Technology（防务技术） 2024年第3期33卷 463-474页

作者： Yili wang Changsheng Li Xiaofeng wang Nanjing University of Science and Technology Nanjing 210094JiangsuChina State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

When employing penetration ammunition to strike multi-story buildings,the detection methods using acceleration sensors suffer from signal aliasing,while magnetic detection methods are susceptible to interference from ferromagnetic materials,thereby posing challenges in accurately determining the number of *** address this issue,this research proposes a layer counting method for penetration fuze that incorporates multi-source information fusion,utilizing both the temporal convolutional network(TCN)and the long short-term memory(LSTM)recurrent *** leveraging the strengths of these two network structures,the method extracts temporal and high-dimensional features from the multi-source physical field during the penetration process,establishing a relationship between the multi-source physical field and the distance between the fuze and the target plate.A simulation model is developed to simulate the overload and magnetic field of a projectile penetrating multiple layers of target plates,capturing the multi-source physical field signals and their patterns during the penetration *** analysis reveals that the proposed multi-source fusion layer counting method reduces errors by 60% and 50% compared to single overload layer counting and single magnetic anomaly signal layer counting,*** model's predictive performance is evaluated under various operating conditions,including different ratios of added noise to random sample positions,penetration speeds,and spacing between target *** maximum errors in fuze penetration time predicted by the three modes are 0.08 ms,0.12 ms,and 0.16 ms,respectively,confirming the robustness of the proposed ***,the model's predictions indicate that the fitting degree for large interlayer spacings is superior to that for small interlayer spacings due to the influence of stress waves.

关键词： Penetration fuze Temporal convolutional network(TCN) Long short-term memory(LSTM) Layer counting Multi-source fusion

Framework for Preventive Control of Power Systems to Defend Against Extreme Events

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 856-870页

作者： Yuwei Xiang Tong wang Zengping wang State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China

Enhancing power system resilience against extreme events is becoming increasingly critical. This paper discusses a unified framework for preventive control of power systems to enhance system resilience, which includes three parts: resilience assessment, resilience grading, and resilience enhancement. First, the resilience assessment contains facility-level and system-level resilience assessment. The concept of fragility curve is used in the facility-level resilience assessment. Various resilience indices are developed in system-level resilience assessment to roundly depict the impacts of extreme events on power systems and determine the system resilience. On this basis, the resilience is divided into different levels by resilience grading strategy, which can efficiently quantify the severity of the impact of extreme events and provide decision-making for the resilience enhancement strategies. Then, control strategies for enhancing power system resilience are also divided according to different resilience levels. A controlled islanding based preventive control is proposed to enhance system resilience, which aims to strengthen the first defensive line of power systems to deal with extreme events. Finally, taking the typhoon disaster in extreme events as an example, two tests carried out with two typhoons demonstrate the efficiency of the proposed method.

关键词： Controlled islanding extreme events power system resilience preventive control