自愿参与机制下的公共物品博弈与合作演化

在自愿参与机制下,采用多维马尔科夫过程对随机演化公共物品博弈中系统的状态进行建模.利用马氏过程的极限分布研究了随机系统的均衡和群体合作行为.将结果与确定性复制动态模型进行了对比.研究发现,强度趋于零的随机性会改变系统的演化行为,相同的博弈参数下两类系统表现出不同的演化结果;对于随机系统,较小的投资收益系数和固定收益即能有效阻止背叛策略的复制,较大的投资收益系数和固定收益即能有效促进合作策略的复制.总体上,随机系统更有利于群体合作的演化.

社会困境博弈中群体合作行为演化研究综述

人类复杂行为模式下合作自发涌现的条件已成为多个学科关注的焦点,探讨合作产生的条件对于理解人类社会中的制度安排有着重要的科学意义和理论价值。社会困境博弈为研究多人合作问题提供了理论原型。演化博弈论作为一种包含参与人学习和策略调整过程的动态分析框架,目前已成为分析社会困境中合作演化最有效的方法。对采用演化博弈方法研究社会困境博弈中群体合作问题的研究进展进行了系统总结和评述。具体包括:社会困境博弈模型、演化博弈论及均衡分析方法的研究进展;奖惩机制和声誉机制下的社会困境博弈与合作演化研究进展;具有分离策略和剥削策略的社会困境博弈与合作演化研究进展;网络互惠下的社会困境博弈与合作演化研究进展。最后对这一领域可以进一步拓展的研究问题进行了展望。

基于风险链和风险地图的风险识别和分析方法——以某海外EPC电力工程为例

为了更有效地对海外EPC工程项目进行风险分析和风险控制管理,对工程风险中涉及的风险源、风险因素、风险事件、风险后果及风险损失概念进行了界定和分类。从总承包商的角度,给出了海外EPC建设工程项目的相应风险清单。提出了基于风险链和风险地图的风险识别和分析方法,用具体的海外EPC电力总承包工程作为算例进行了项目风险地图的构建。此套方法可使风险识别和分析的过程程序化,并将所有的风险都统一成费用进行分析,风险链和风险地图的构建过程即为分析风险对费用影响的过程,极大程度地方便了后续风险评估环节的工作。

Design of the upstream decay pipe window of the long baseline neutrino facility

The beam windows of high-energy beam lines are important,and it is sometimes difficult to design because it is necessary to ensure particle propagation with minimum disturbance and fulfill mechanical requirements at the same time.The upstream decay pipe window of the long baseline neutrino facility at Fermilab has an extremely large diameter(1.8 m),with a thickness of only 1.5 mm to separate the helium atmosphere in the decay pipe and the nitrogen atmosphere on the other side.Furthermore,the center of this dish-shaped window is expected to be a200-mm-diameter beryllium dish welded to the outside aluminum alloy A6061,and this welded combination must withstand extreme conditions of a 2.4-MW,high-energy proton beam without leakage.These severe conditions make the design of this window an unprecedented challenge.This paper describes the static thermal-structural analyses based on which the structure has been optimized,as well as dynamic analyses for understanding the shockwave effects originating in the beam.After optimization,the maximum von Mises stresses in the window decreased significantly in both normal operation and accident cases,making our design very reasonable.

法学名著读书会在本科教学中的实践探索——以辽宁大学法学名著读书会为例

在法学院本科教学之外,由本科班主任教师主持法学名著读书会,旨在纾解学生不想读、没空读、读不懂名著的问题,并将思政教育与法学专业知识相融合。主持法学名著读书会,要明确读书会的预期目标,探索读书会的运行机制,并在未来的读书会改革中,将读书会与本科班主任制度深度融合,加入量化考核机制,还与外语学院师生联合,共建新文科本科教学。

不同喷涂工艺对Cr3+掺杂Al2O3陶瓷涂层相结构及发光性能影响研究

通过火焰喷涂工艺和等离子喷涂工艺制备了Cr^3+掺杂Al2O3陶瓷涂层。采用扫描电镜、X射线衍射、荧光光谱仪等方法表征了涂层的微观形貌、孔隙率、相结构及发光性能等。对比两种不同工艺制备的Cr^3+掺杂Al2O3陶瓷涂层性能结果表明:等离子喷涂制备的涂层形貌、颗粒熔化状态、厚度均一性均优于火焰喷涂涂层,但火焰喷涂工艺涂层的发光性能远优于等离子工艺涂层,其原因是火焰喷涂制备的涂层中Al2O3粒子的熔融状态更差,保留了更多的α-Al2O3相,未熔粒子部分将以喷涂原粉中稳定的α-Al2O3结构存在涂层中进而影响其光学性能。

项目管理沙盘模拟教学实践探索

高校教学中,教师通常采用多媒体教学,但是课堂效果并不理想,这种现象与教师的授课无趣有直接关系。工程类课程大多是实践性非常强的科目,学生听不懂,没有概念,没有想象,所以引发此现象。以我校土木工程专业学生课堂引入沙盘实践项目为例,模拟项目的全过程管理。学生通过策划、实施等活动感受项目过程,学习管理技巧,提高动手能力,并且加强团队意识。通过教学改革,沙盘实践取得了比较好的效果,提出后续推广计划,并针对我校实际提出建议。

CEPC Technical Design Report

The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs factory.In its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs bosons.Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of magnitude.This Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering aspects.Additionally,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection procedures.Construction is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 years.The commencement of experiments and data collection could potentially be initiated in the mid-2030s.

具有惩罚策略的公共物品博弈与合作演化

采用演化博弈方法,研究具有代价的第二方惩罚机制对于公共物品博弈均衡选择及群体合作行为的影响.将群体策略选择过程描述成一个多维马氏过程,通过极限分布分析系统演化稳定状态.分别考虑只对背叛策略进行惩罚的一阶惩罚机制和同时对背叛及不惩罚背叛的合作(二阶背叛)都进行惩罚的二阶惩罚机制.研究发现,与一阶惩罚相比,二阶惩罚机制可以在更大参数范围内促进群体合作的产生,系统存在选择不同均衡结果的惩罚参数临界值.并将结果与复制动态模型进行了对比.

Some Analytical Properties of the Model for Stochastic Evolutionary Games in Finite Populations with Non-uniform Interaction Rate

Traditional evolutionary games assume uniform interaction rate, which means that the rate at which individuals meet and interact is independent of their strategies. But in some systems, especially biological systems, the players interact with each other discriminately. Taylor and Nowak (2006) were the first to establish the corresponding non-uniform interaction rate model by allowing the interaction rates to depend on strategies. Their model is based on replicator dynamics which assumes an infinite size population. But in reality, the number of individuals in the population is always finite, and there will be some random interference in the individuals' strategy selection process. Therefore, it is more practical to establish the corresponding stochastic evolutionary model in finite populations. In fact, the analysis of evolutionary games in a finite size population is more difficult. Just as Taylor and Nowak said in the outlook section of their paper, 'The analysis of non-uniform interaction rates should be extended to stochastic game dynamics of finite populations.' In this paper, we are exactly doing this work. We extend Taylor and Nowak's model from infinite to finite case, especially focusing on the influence of non-uniform connection characteristics on the evolutionary stable state of the system. We model the strategy evolutionary process of the population by a continuous ergodic Markov process. Based on the limit distribution of the process, we can give the evolutionary stable state of the system. We make a complete classification of the symmetric 2×2 games. For each case game, the corresponding limit distribution of the Markov-based process is given when noise intensity is small enough. In contrast with most literatures in evolutionary games using the simulation method, all our results obtained are analytical. Especially, in the dominant-case game, coexistence of the two strategies may become evolutionary stable states in our model. This result can be used to explain the emergence of cooperation in the Prisoner is Dilemma Games to some extent. Some specific examples are given to illustrate our results.

Design of imaging system for CSNS near-target beam diagnostics

Introduction China Spallation Neutron Source(CSNS)is an accelerator-based pulsed neutron source which produces neutron with spallation reaction induced by proton bombarding tungsten target.With increasing beam powers and influences on target,near-target monitoring becomes extreme necessary.In this situation,an optical imaging system for proton beam diagnostics and monitoring near the target is being developed at CSNS,which can provide real-time images of the beam on target and beam distribution information.Target imaging system design and development In the design of CSNS target imaging system,coating of Cr^(3+):Al_(2)O_(3) is used to convert particle radiation into emission light.According to the geometry limits of CSNS target station,a special optical system was designed and fabricated to collect the emission light.When the proton beams strike on the target,the coating on the target will be excited,emitting luminescence at the same time.The mirrors and lenses of the optical system image the distribution of emission light into a radiation-hard imaging fiber,which transmits the images to the GigE camera located at low-dose area outside of the target station.Software was written on the LabView platform to control the camera and analyze the images on line.Mock-up of the imaging system was manufactured to test and evaluate the performances of the system.Some important characteristics of the system were obtained and studied.Conclusion Tests on the mock-up of the system present reliably expectation for beam diagnostics.The imaging system has been installed at CSNS recently.More work will be continued to improve the properties of the system.

Measurements and characteristics of Al_(2)O_(3):Cr^(3+) coating for the proton beam imaging system

Introduction To set up an online proton beam diagnostic system near the neutron production target of China Spallation Neutron Source(CSNS),a luminescence coating sprayed on the target windowand a corresponding optic system were fabricated.In the work,the fabrication of Al_(2)O_(3):Cr^(3+) coating was explored.Measurements on the sprayed samples were performed to analyze the characteristics of the Al_(2)O_(3):Cr^(3+) coating.Fabrication and tests of coating samples Three kinds of powders with different Cr concentrations were used to fabricate the luminescence coating samples.The flame spraying,plasma spraying and D-gun spraying processes were explored.Photoluminescence(PL),X-ray diffraction(XRD),scanned electron mirror(SEM)and radioluminescence experiment by 300 MeV deuterium beam were carried out to analyze and characterize the samples.Results The emission spectrum excited by 532-nm laser has two obvious peaks at 692.9 nm and 694.3 nm.The samples by flame spraying process with the powders obtained from melting method show higher luminescence intensity than the samples by plasma spraying process.It is observed that the luminescence intensity has some relationships with the alpha phase in the samples,which is deduced from the XRD and photoluminescence tests results.A lower temperature during the flame spraying process will help to keep more alpha phase in the material.The selected four samples show successful fluoresced results in the radioluminescence experiment.Conclusions The luminescence intensity of the coating is improved greatly by the studies on the fabrication process and the characteristics of the samples.The luminescence coating used in beam diagnostics will be fabricated by the confirmed technical process.More works will be continued to improve the characteristics of the luminescence light by controlling Cr concentration and annealing in 1200∼2000℃ environment in the future.

韩国土地征收法制——以营农损失补偿制度为中心

中韩两国土地制度存在一定趋同性,即均面临人多地少、土地资源匮乏的现实问题。本文系统介绍了韩国土地征收制度,并在此背景下分析营农损失补偿制度。营农损失补偿制度是一种生活补偿制度,但不同于土地及地上附着物的补偿。损失补偿的间接损失或逸失损失①也可作为现代意义上的财产权,韩国在《宪法》第23条明确规定了正当补偿的内容。但是,相比一般损失补偿制度,营农补偿制度呈现较强的社会拘束性以及相对宽泛的立法裁量空间。因此有必要明确营农补偿制度的法律性质及其具体基准。我国在2019年8月26日第十三届全国人大常委会第十二次会议通过了修改《土地管理法》的决定,在原补偿基础上增加农村村民的住宅补偿和社会保障费。在完善和发展生活补偿的相关法律制度方面,韩国的经验在比较研究上具有借鉴意义。

韩国土地公法史

本文主要检讨韩国公法领域的土地法制变迁历程。韩国以规制国民财产权为方向制定及修订了相关土地法律,通过合理有效利用土地促进国土资源均衡发展、增进公共福利。尽管过去韩国为了土地法制体系化做了很大努力,但土地相关法制未能实现克服时代变化引发的状况,以及进行必要的分散性整顿和限制的立法需求。法律体系的规范整合性以及完成度不足、计划缺乏连接性、国土管理及规划不善,导致土地利用混乱、以居民为核心的利害关系人参与计划不足、欠缺实效性、缺乏环境保护反馈等诸多问题。土地法制应协调土地的社会拘束性以及公法规范,并且考虑到土地既是生活基础又是有限资源的特性,应以双面协调视角将内容体系分为所有和利用、管理和保全、开发和纠纷解决三个部分,这也应该是日后土地法典的形成体系。