Seismic effectiveness evaluation and optimized design of tie up method for securing museum collections

To quantify the seismic effectiveness of the most commonly used fishing line tie up method for securing museum collections and optimize fixed strategies for exhibitions,shaking table tests of the seismic systems used for typical museum collection replicas have been carried out.The influence of body shape and fixed measure parameters on the seismic responses of replicas and the interaction behavior between replicas and fixed measures have been explored.Based on the results,seismic effectiveness evaluation indexes of the tie up method are proposed.Reasonable suggestions for fixed strategies are given,which provide a basis for the exhibition of delicate museum collections considering the principle of minimizing seismic responses and intervention.The analysis results show that a larger ratio of height of mass center to bottom diameter led to more intense rocking responses.Increasing the initial pretension of fishing lines was conducive to reducing the seismic responses and stress variation of the lines.Through comprehensive consideration of the interaction forces and effective securement,it is recommended to apply 20%of breaking stress as the initial pretension.For specific museum collections that cannot be effectively protected by the independent tie up method,an optimized strategy of a combination of fishing lines and fasteners is recommended.

基于TCIA和CVM的皇家园林游憩价值评估研究——以北京市颐和园为例

运用科学方法评估皇家园林游憩价值对旅游资源的有效保护与合理利用具有重要意义。通过对北京市颐和园皇家园林运用旅行费用区间法(TCIA)和条件价值法(CVM)进行评估,得出以下结论:1)从使用价值来看,旅游者实际旅行费用>旅游消费者剩余,颐和园皇家园林在游憩资源利用方面已经基本满足了游客的体验需求,但仍有提升空间;2)从非使用价值的角度来看,存在价值最高,其次为遗产价值,最后为选择价值,游憩非使用价值量居于中上等水平。由于游客对皇家园林的保护意识存在显著差异,导致人均WTP也有所不同;3)从综合角度来看,颐和园皇家园林的游憩使用价值远大于非使用价值,说明颐和园皇家园林的游憩资源非使用价值并未得到充分利用,仍有很大的挖掘潜力;4)从两种方法的适用性来看,TCIA和CVM方法适用于与颐和园相似的皇家园林的游憩价值评估。

Optimal Design of Aperture Illuminations for Microwave Power Transmission with Annular Collection Areas

This work presents an optimal design method of antenna aperture illumination for microwave power transmission with an annular collection area.The objective is to maximize the ratio of the power radiated on the annular collection area to the total transmitted power.By formulating the aperture amplitude distribution through a summation of a special set of series,the optimal design problem can be reduced to finding the maximum ratio of two real quadratic forms.Based on the theory of matrices,the solution to the formulated optimization problem is to determine the largest characteristic value and its associated characteristic vector.To meet security requirements,the peak radiation levels outside the receiving area are considered to be extra constraints.A hybrid grey wolf optimizer and Nelder–Mead simplex method is developed to deal with this constrained optimization problem.In order to demonstrate the effectiveness of the proposed method,numerical experiments on continuous apertures are conducted;then,discrete arrays of isotropic elements are employed to validate the correctness of the optimized results.Finally,patch arrays are adopted to further verify the validity of the proposed method.

Opinion consensus incorporating higher-order interactions in individual-collective networks

In the current information society, the dissemination mechanisms and evolution laws of individual or collective opinions and their behaviors are the research hot topics in the field of opinion dynamics. First, in this paper, a two-layer network consisting of an individual-opinion layer and a collective-opinion layer is constructed, and a dissemination model of opinions incorporating higher-order interactions(i.e. OIHOI dissemination model) is proposed. Furthermore, the dynamic equations of opinion dissemination for both individuals and groups are presented. Using Lyapunov's first method,two equilibrium points, including the negative consensus point and positive consensus point, and the dynamic equations obtained for opinion dissemination, are analyzed theoretically. In addition, for individual opinions and collective opinions,some conditions for reaching negative consensus and positive consensus as well as the theoretical expression for the dissemination threshold are put forward. Numerical simulations are carried to verify the feasibility and effectiveness of the proposed theoretical results, as well as the influence of the intra-structure, inter-connections, and higher-order interactions on the dissemination and evolution of individual opinions. The main results are as follows.(i) When the intra-structure of the collective-opinion layer meets certain characteristics, then a negative or positive consensus is easier to reach for individuals.(ii) Both negative consensus and positive consensus perform best in mixed type of inter-connections in the two-layer network.(iii) Higher-order interactions can quickly eliminate differences in individual opinions, thereby enabling individuals to reach consensus faster.

Computational Study of Collective Cell Migration By Meshfree Method

The collective cell migration behavior on a substrate was studied using RKPM meshfree method.The cells were modeled as nematic liquid crystal with hyperelastic cell nucleus.The cell-substrate and cell-cell interactions were modeled by coarse-grained potential forces.Through this study,the pulling and pushing phenomenon during collective cell migration process was observed and it was found that the individual cell mobility significantly influenced the collective cell migratory behavior.More self-propelled cells are in the system along the same direction,the faster the collective group migrates toward coordinated direction.The parametric study on cell-cell adhesion strength indicated that as the adhesion strength increases,the collective cell migration speed increases.It also showed that the mechanical stress in leader cell is higher than stress in follower cells.

Core Collection of Cassava ( Manihot esculenta Crantz) Germplasm

[Objective] This paper aimed to construct the core collection of cassava germplasm. [Methods] Parameter values of six traits of 161 clones were ana-lyzed and evaluated. [ Results] Minkowski genetic distance was established for cluster analysis of core collection. Preferred sampling method （D 2C5S3） was suit-able for the construction of the core collection of cassava. A total of 25 core collections were obtained, which accounted for 15% of the original germplasm and could represent the genetic diversity and integrity of the original germplasms. Meanwhile, it reflected that the genetic background of the tested cassava germplasm was nar-row and the range of genetic diversity was quite small with genetic redundancy. [ Conclusions] Constructing core collection provided a theoretical foundation for the protection and utilization of cassava germplasms.

Collecting Statistical Methods for the Analysis of Climate Data as Service for Adaptation Projects

The development of adaptation measures to climate change relies on data from climate models or impact models. In order to analyze these large data sets or an ensemble of these data sets, the use of statistical methods is required. In this paper, the methodological approach to collecting, structuring and publishing the methods, which have been used or developed by former or present adaptation initiatives, is described. The intention is to communicate achieved knowledge and thus support future users. A key component is the participation of users in the development process. Main elements of the approach are standardized, template-based descriptions of the methods including the specific applications, references, and method assessment. All contributions have been quality checked, sorted, and placed in a larger context. The result is a report on statistical methods which is freely available as printed or online version. Examples of how to use the methods are presented in this paper and are also included in the brochure.

Sperm collection in Black-legged Kittiwakes and characterization of sperm velocity and morphology

Background:Collecting and studying live sperm is central to many important fields of biology.Yet,a simple method to collect live sperm is lacking in wild seabird species.Here,we describe a non?invasive method to collect viable sperm samples based on a simple massage technique applied to male Black?legged Kittiwakes(Rissa tridactyla).Methods:We studied a colony breeding at Kongsfjorden,Svalbard and successfully obtained sperm samples from 32 males.With a subset of samples(n = 12 males),we compared the suitability of several extenders(0.9% NaCl,PBS,Earle's balance salt solution,Dulbecco's modified Eagle medium) in maintaining sperm alive long enough for analyses.With another 18 ejaculates,we conducted computer assisted sperm analyses using the CASA plugin for ImageJ.We provide details about the settings to be used for such analyses.Lastly,droplets from 20 ejaculates were smeared on glass slides and preserved with formalin to characterize sperm morphology in terms of total sperm length,sperm head length,midpiece length and flagellum length,and percentage of abnormal sperm.Results:With this method and under field conditions,we were able to obtain sufficient amounts of live sperm to assess traits related to sperm quality(e.g.sperm morphology,percentage of motile sperm,sperm velocity).We found that two extenders,Earle's balanced salt solution and Dulbecco modified Eagle's medium,yielded similarly good results.Additionally,we investigated whether specific behaviours were associated with successful sperm collection and whether sperm collection success depended on how long before laying sperm collection was attempted.Finally,we provide mean values for sperm morphology,sperm swimming ability and percentage of motile sperm,which may prove useful for future comparative analyses,and we report high levels of sperm abnormality and within?ejaculate variation in sperm morphology.Conclusions:We discuss the high percentage of abnormal sperm and high within?ejaculate variation in sperm morphology in light of sperm competition theory and conclude that these figures are likely due to relaxed post?cop?ulatory sexual selection,kittiwakes being strictly monogamous.Finally,we suggest that this method could be applied to other seabird species sharing similar ecology.

基于条件价值法(CVM)的西黑冠长臂猿非使用价值评估

对野生动物资源进行价值评估是保护生物学研究的核心,也是管理决策制定与生态补偿的重要依据。利用条件价值法(CVM),通过简单随机抽样的方式对景东城镇居民的支付意愿(WTP)进行调查,评估西黑冠长臂猿的非使用价值。结果表明:85.52%的受访者认为应该对该物种进行保护,86.43%的受访者愿意支付一定的费用来保护该物种。利用中位值法和平均值法得出城镇居民的支付意愿为51.86—54.04元·a^(-1),推测得西黑冠长臂猿的非使用价值为421.87—439.60亿元·a^(-1)。Logit和Probit模型实证分析结果表明,支付意愿与受访者学历、个人收入以及对西黑冠长臂猿的了解程度呈显著正相关(P<0.05),与年龄呈显著负相关(P<0.05),与性别、民族等相关性不显著(P>0.05)。

A Study of Data Collection based on the Analysis of Interviews and Questionnaires

There are several approaches to data collection, such as questionnaires, interviews, observations, focus groups and so on. This essay will look at two specific methods, interviews and questionnaires. It will involve individual strengths and weaknesses at first and then have a brief clarification of'why'and'when'to use. Finally, this essay will list out some problems that researchers might face during the process.

基于CVM的气象指数保险支付意愿分析

支付意愿在一定程度上反映了保险购买者的需求状况,即使是经济发达地区也存在支付意愿不强的问题。首先,以条件价值估算法(CVM)获取的淡水鱼养殖户调研数据为依据,对养殖户购买气象指数保险的平均支付意愿进行测算,得出平均支付意愿为2956.35元/hm^(2),远低于实际保费。运用Logit模型对农户购买气象指数保险支付意愿的影响因素进行实证分析,发现家庭总资产与支付意愿显著负相关,养殖淡水鱼收入占总收入的比重和养殖户对气象指数保险的认可度与支付意愿显著正相关。最后,根据实证结果提出有利于提升气象指数保险支付意愿的几点建议。

离散元法在月面建造力学分析中的研究及应用

【目的】为了深入了解月面建造过程中月壤的力学特性,评估月基装备性能,优化月面建造作业,开展离散元法(discrete element method,DEM)在月壤接触力学领域的应用调查研究,旨在利用离散元法为未来月球基地建设提供理论指导和技术支持。【研究现状】基于地质勘探、资源采集及运输、建造作业等月面原位建造任务场景,分析月壤颗粒的建模与参数标定,介绍月基装备与月壤的接触作用研究现状,概述离散元法在钻-壤作用模拟、铲-壤作用模拟、轮-壤作用模拟及足-壤作用模拟中的应用,探讨基于离散元法的天然月基承载力分析。【结论与展望】提出降低几何模型复杂度、优化粒间接触模型及参数是提高宏观尺度月壤离散元建模精度以应对大规模月面建造场景的有效方法。认为利用离散元法进行铲挖式月壤采集装置及足式月球车设计在未来可以为月面建造提供可靠的技术支持。面向月面建造,离散元法将在水冰资源利用、建筑物月面承载力分析等方面提供科学依据。

大数据税收征管对企业风险承担的影响研究

当前我国企业的风险承担处于较低水平,这给企业的可持续发展和国家的长期繁荣带来了极大的挑战。借助“金税三期”工程这一准自然实验,采用多期双重差分法研究了大数据税收征管对企业风险承担的影响及作用机制,研究表明:大数据税收征管对企业风险承担具有显著促进作用。机制检验发现,大数据税收征管通过抑制代理行为、缓解融资约束、增进税负公平、优化营商环境来促进企业风险承担。进一步的分析表明,大数据税收征管对非国有企业和有产业政策扶持企业风险承担的促进作用更大。

基于幅度和相位融合的微波两相流测量系统设计

针对油井开采过程中需要对各相含量进行精确预测以调整开采策略的实际问题,设计了一种基于微波法的油水两相流检测系统。该系统利用微波在不同介质中透射能力的差异,构建了一套包含微波信号源、功率放大器、功率分配器、检波器和STM32F103ZET6核心板的硬件电路系统,通过编写AD采集和串口通信的软件代码,来接收检波器端幅度和相位数据。在数据处理方面,分别对幅度数据、相位数据和幅度-相位融合数据采用BP神经网络的方法预测含水率。实验表明:在使用融合数据时,预测准确度可以提高至96.33%,取得了较理想的效果。

新型农村集体经济高质量发展赋能共同富裕——基于20个革命老区的实证

文章基于系统理论和组态视角,聚焦革命老区新型农村集体经济高质量发展对共同富裕的赋能作用及其多因素联动效应。采用动态QCA方法分析2016—2021年我国20个革命老区重点城市的面板数据,探索新型农村集体经济高质量发展在时间维度上的组态效应,并通过Kruskal-Wallis秩和检验探究各组态在革命老区覆盖度上的空间分布差异。研究发现:单个因素并不构成高共同富裕水平的必要条件,但科技创新与技术进步、人力资本的必要性存在逐渐递增的时间效应。四条组态的一致性水平均较高,都在0.85以上,进一步提炼出共同富裕的四条组态路径,分别为“人力-科技联动型”“制度创新主导型”“科技创新驱动型”及“乡土资源开发利用型”,其中,人力资本与土地利用之间存在替代效应;在时间维度上,总体表现为解释力逐步增强,且2020年出现骤增拐点;在空间维度上,有两条组态的覆盖度存在明显的地区分布差异。

中国近岸区域微塑料污染的研究进展

为全面评估我国近岸微塑料的污染现状,本文综述了我国近岸大气、陆地和海洋不同区域微塑料的采集分离、分析方法、污染分布特征及生态危害等的研究进展,并展望了我国近岸微塑料未来研究方向.研究表明,近岸大气、沉积物和海水均有微塑料的存在,相较于全球其他近岸海域,我国近岸微塑料丰度范围整体上处于中低水平.此外,微塑料及其复合污染物对我国近海生态造成一定危害.我国近岸微塑料在时空分布、源汇格局及生态风险机制方面尚不明确,建议未来在微塑料研究方法标准化的基础上,对微塑料污染进行大范围的长期监测,关注微塑料在大气-陆地-海洋之间的迁移输运,并对微塑料复合暴露的毒理机制及其对人类潜在健康风险等方面进行探索和研究,为我国海洋微塑料污染评估和治理提供参考.

基于三维虚拟试衣系统的服装类藏品虚拟展示方法

服装类藏品虚拟展示往往由于未计算服装虚拟模型与人体真实模型的匹配度,导致虚拟展示方法的应用效果不佳,故设计了基于三维虚拟试衣系统的服装类藏品虚拟展示方法。利用数码相机采集服装类藏品的数据信息,根据服装结构特性对采集的数据信息进行聚类处理,输入三维虚拟试衣系统中,生成服装虚拟模型并与相应的人体模型匹配,计算两者之间的匹配度,根据匹配结果构建虚拟模型并计算相关参数,实现服装类藏品的虚拟展示。与以往的服装类藏品虚拟展示方法相比,该方法所需的展示时间仅为2.64 ms,应用效果更好。

税收征管规范化与企业盈余管理--基于税务行政处罚裁量基准的准自然实验

以2013—2022十年里我国A股上市公司数据为样本探究税收征管规范化与企业盈余管理之间的关系。研究结果表明,各地税务行政处罚裁量基准的实施显著降低了企业的盈余管理水平,并且进一步发现该现象在非国有产权性质和内部控制薄弱的企业中更为明显。

基于CVM的景观游憩价值评估研究--以太白山国家森林公园为例

采用意愿调查法(CVM),在随机抽取500名游客进行调查的基础上,获取了游客对太白山森林公园景观游憩功能的支付意愿(WTP)、支付意愿值及其相关影响因素,计算出WTP中位值为50.00元,并采用列联表分析和χ2检验法对相关影响因素进行显著性检验,分析得出文化程度、技术职称和经济收入等因素对WTP值极显著相关,计算出了2004年太白山森林景观游憩功能的总支付意愿为5242万元,并为CVM今后的应用提出了合理的建议。

基于CVM的旅游资源非使用价值评估——以历史文化名城阆中为例

在实地调查的基础上,采用条件价值法(CVM)对古城阆中旅游资源的非使用价值进行评估,结果表明当地居民的支付意愿(WTP)较低,运用相关与logistic回归分析,得出WTP受到居住地、教育程度等诸多因素影响,建议地方政府和古城旅游公司依据不同主体地位采取相应的引导措施及方案,使居民有效参与古城旅游开发,促进旅游可持续发展.