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人类排放情景的设计与全球变暖预估

气候变化研究进展 2024年第2期20卷 261-264页

作者：赵宗慈罗勇黄建斌清华大学地球系统科学系北京100084 中国气象局国家气候中心北京100081 中国科学院大学资源环境学院北京100049

1气候变化的原因全球气候变化除地球系统内部变率外,自然强迫和人为强迫是重要的外部驱动力。其中自然强迫包括太阳活动和火山活动。人为强迫即人类活动,包括大量化石燃料燃烧排放温室气体、土地利用,以及气溶胶与污染排放等,其强度取... 详细信息

1气候变化的原因全球气候变化除地球系统内部变率外,自然强迫和人为强迫是重要的外部驱动力。其中自然强迫包括太阳活动和火山活动。人为强迫即人类活动,包括大量化石燃料燃烧排放温室气体、土地利用,以及气溶胶与污染排放等,其强度取决于人口发展与变化、社会经济发展、技术变化及其内部的协调性等。本文重点给出人类强迫的影响。IPCC第六次评估报告明确表明,近百年特别是近几十年来观测到的全球变暖归因为人类活动的影响。

关键词：太阳活动火山活动排放情景全球变暖社会经济发展全球气候变化人类强迫变率

Post-layout simulation driven analog circuit sizing

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Science China(Information Sciences) 2024年第4期67卷 289-300页

作者： Xiaohan GAO Ha.yi zHANG Siyuan yE Mingjie LIU David z.PAN Linxiao SHEN Runsheng WANG yibo LIN Ru HUANG School of Integrated Circuits Peking University School of Computer Science Peking University Department of Electrical and Computer Engineering University of Texas at Austin Institute of Electronic Design Automation Peking University

Post-layout simulation provides accurate guidance for analog circuit design, but post-layout performance is hard to be directly optimized at early design stages. Prior work on analog circuit sizing often utilizes pre-layout simulation results as the optimization objective. In this work, we propose a post-layoutsimulation-driven(post-simulation-driven for short) analog circuit sizing framework that directly optimizes the post-layout simulation performance. The framework integrates automated layout generation into the optimization loop of transistor sizing and leverages a coupled Bayesian optimization algorithm to search for the best post-simulation performance. Experimental results demonstrate that our framework can achieve over 20% better post-layout performance in competitive time than manual design and the method that only considers pre-layout optimization.

关键词： analog EDA transistor sizing Bayesian optimization post-layout simulation

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岩石圈内榴辉岩的命运

中国科学：地球科学 2024年第3期54卷 897-901页

作者：王振胜徐义贤中国地质大学地质过程与矿产资源国家重点实验室武汉430074 浙江省地学大数据和地球深部资源重点实验室浙江大学地球科学学院杭州310058

1榴辉岩及其黏性排出的概念榴辉岩是由洋壳或陆壳岩石在俯冲、碰撞等构造埋深作用下,增压到1~1.5GPa以上,发生超高压变质作用(ultra-high pressure metamorphism)而生成的以石榴子石和绿辉石为主要矿物组成的特殊岩石类型.深源捕虏体研... 详细信息

1榴辉岩及其黏性排出的概念榴辉岩是由洋壳或陆壳岩石在俯冲、碰撞等构造埋深作用下,增压到1~1.5GPa以上,发生超高压变质作用(ultra-high pressure metamorphism)而生成的以石榴子石和绿辉石为主要矿物组成的特殊岩石类型.深源捕虏体研究表明克拉通岩石圈地幔中也存在一定量的榴辉岩,可能与早期俯冲或地幔柱活动有关(Aulbach和Smart, 2023).

关键词：超高压变质作用石榴子石绿辉石深源捕虏体榴辉岩岩石类型克拉通岩石圈地幔柱活动

Bell Polynomial Approach for the Solutions of Fredholm Integro- Differential Equations with Variable Coefficients

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Computer Modeling in Engineering & Sciences 2020年第6期123卷 973-993页

作者： Gökçe yıldız Gültekin Tınaztepe Mehmet Sezer Department of Mathematics Faculty of ScienceManisa Celal Bayar UniversityManisaTurkey Vocational School of Technical Sciences Akdeniz UniversityAntalyaTurkey

In this article,we approximate the solution of high order linear Fredholm integro-differential equations with a variable coefficient under the initial-bounda.y conditions by Bell *** collocation points and treating the solution as a linear combination of Bell polynomials,the problem is reduced to linear system of equations whose unknown variables are Bell *** solution to this algebraic system determines the approximate *** estimation of approximate solution is *** examples are provided to illustrate the performance of the *** numerical results are compared with the collocation method based on Legendre polynomials and the other two methods based on Taylor *** is observed that the method is better than Legendre collocation method and as accurate as the methods involving Taylor polynomials.

关键词： Bell polynomials collocation points matrix method Fredholm integrodifferential equations.

Increasing polymer scission rate by tying an overhand knot

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Science China Chemistry 2024年第11期67卷 3498-3499页

作者： yuheng Hu Jennifer T.Ou Jim y.Huang yuanning Feng Department of Chemistry and Biochemistry The University of Oklahoma

Similar to the phenomenon of knotted ropes in life, knotted climbing ropes will reduce their strength due to knots. Although computer simulations [1], theoretical speculation[2,3], and intuition [3] suggest that similar processes may occur at the nanoscale, this hypothesis has not been experimentally proven before. With the increasing maturity of molecular recognition and self-assembly, a research communication by Leigh et al. [4] published in Nature Chemistry introduced a molecular overhand knot into a polymer to study its effect on the scission rate of the polymer chain under tension.

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Violence toward emergency physicians: A prospective-descriptive study

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World Journal of Emergency Medicine 2021年第2期12卷 111-116页

作者： Kasım Turgut Erdal yavuz Mine Kayacıyıldız Mehmet Kaan Poyraz Department of Emergency Medicine Research and Training HospitalAdiyaman UniversityAdiyaman 02100Turkey

BACKGROUND: The highest rate of workplace violence occurs in the health sector, although most cases remain unreported. Emergency services face the majority of these incidents for ma.y reasons, such as the patient profile, long waiting time, and overcrowding. We aimed to determine the characteristics and causes of violence toward emergency physicians. METHODS: The acts of violence toward emergency physicians over a one-year period were prospectively recorded. After a violent incident took place, a third party separately interviewed the physician exposed to the violent behavior and the perpetrator who displayed this behavior. We examined the perpetrator's reasons for violence, their demographic characteristics, and the medical complaints of patients involved in such events to determine the characteristics and causes of ***: Of the violent acts investigated, 85.1% were verbal, and most were directed toward male doctors by the young male relatives of the patients. More than half of the violent acts occurred within the 15 minutes of presentation to emergency service(60.5%) and at off-hours(69.4%). Concerning the health insurance, 20.4% of the cases were covered by the free green card system, and a small number of the perpetrators of violence lived in rural areas(38.2%). The most common reason for violent behavior was the patients' or their relatives' dissatisfaction with the examination or treatment method(38.2%).CONCLUSIONS: Appropriate communication should be established with the patients, and they should be adequately informed about the treatments and interventions to be performed in order to prevent possible acts of violence.

关键词： Violence Emergency physician Emergency department

Conventional and micro scale finite element modeling for metal cutting process:A review

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Chinese Journal of Aeronautics 2024年第2期37卷 199-232页

作者： Le WANG Caixu yUE Xianli LIU Ming LI yongshi XU Steven y.LIANG Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin University of Science and TechnologyHarbin 150080China George W.Woodruff School of Mechanical Engineering Georgia Institute of TechnologyAtlanta 30332USA

The metal cutting process is accompanied by complex stress field,strain field,temperature *** comprehensive effects of process parameters on chip morphology,cutting force,tool wear and residual stress are complex and *** element method(FEM)is considered as an effective method to predict process variables and reveal microscopic physical phenomena in the cutting ***,the finite element(FE)simulation is used to research the conventional and micro scale cutting process,and the differences in the establishment of process variable FE simulation models are distinguished,thereby improving the accura.y of FE *** reliability and effectiveness of FE simulation model largely depend on the accura.y of the simulation method,constitutive model,friction model,damage model in describing mesh element,the dynamic mechanical behavior of materials,the tool-chip-workpiece contact process and the chip formation *** this paper,the FE models of conventional and micro process variables are comprehensively and up-to-date reviewed for different materials and machining *** purpose is to establish a FE model that is more in line with the real cutting conditions,and to provide the possibility for optimizing the cutting process *** development direction of FE simulation of metal cutting process is discussed,which provides guidance for future cutting process modeling.

关键词： Conventional and micro scale Finite element simulation Metal cutting process Micro cutting Modeling

A particle-resolved heat-particle-fluid coupling model by DEM-IMB-LBM

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2267-2281页

作者： Ming Xia Jinlong Fu y.T.Feng Fengqiang Gong Jin yu Hunan Key Laboratory of Geomechanics and Engineering Safety Xiangtan UniversityXiangtan411105China zienkiewicz Institute for Modelling Data and AISwansea UniversitySwanseaSA18EPUK School of Civil Engineering Southeast UniversityNanjing211189China Fujian Research Center for Tunneling and Urban Underground Space Engineering Huaqiao UniversityXiamen361021China

Multifield coupling is frequently encountered and also an active area of research in geotechnical *** this work,a particle-resolved direct numerical simulation(PR-DNS)technique is extended to simulate particle-fluid interaction problems involving heat transfer at the grain *** this extended technique,an immersed moving bounda.y(IMB)scheme is used to couple the discrete element method(DEM)and lattice Boltzmann method(LBM),while a recently proposed Dirichlet-type thermal bounda.y condition is also adapted to account for heat transfer between fluid phase and solid *** resulting DEM-IBM-LBM model is robust to simulate moving curved boundaries with constant temperature in thermal *** facilitate the understanding and implementation of this coupled model for non-isothermal problems,a complete list is given for the conversion of relevant physical variables to lattice ***,benchmark tests,including a single-particle sedimentation and a two-particle drafting-kissing-tumbling(DKT)simulation with heat transfer,are carried out to validate the accura.y of our coupled *** further investigate the role of heat transfer in particle-laden flows,two multiple-particle problems with heat transfer are *** examples demonstrate that the proposed coupling model is a promising high-resolution approach for simulating the heat-particle-fluid coupling at the grain level.

关键词： Particle-fluid interaction Heat transfer Discrete element method(DEM) Lattice Boltzmann method(LBM) Dirichlet-type thermal bounda.y Direct numerical simulation

Optimal Coordination of Transportable Power Sources and Repair Crews for Service Restoration of Distribution Networks Considering Uncertainty of Traffic Congestion

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 189-201页

作者： zhao Shi yan Xu Dunjian Xie Shiwei Xie Amer M.y.M.Ghias Na.yang Technological University Singapore the School of Electrical Engineering and Automation Fuzhou UniversityFuzhou 350108China

This paper proposes a new method for service restoration of distribution network with the support of transportable power sources(TPSs)and repair crews(RCs).Firstly,a coupling model of distribution networks and vehicle routing of TPSs and RCs is proposed,where the TPSs serve as emergency power supply sources,and the RCs are used to repair the faulted *** the uncertainty of traffic congestion,the probability distribution of the travel time spent on each road is derived based on the Nesterov user equilibrium model,and a two-stage stochastic program is formulated to determine the optimal routings of TPSs and *** efficiently solve the proposed stochastic mixed-integer linear program(MILP),a two-phase scenario reduction method is then developed to scale down the problem size,and an adaptive progressive hedging algorithm is used for an efficient *** effectiveness of the proposed methods and algorithms has been illustrated in a modified IEEE 33-bus system.

关键词： Service restoration distribution network traffic uncertainty transportable power source repair crew stochastic program