基于长江经济带的金融资源与农业资本化耦合实证研究

农业资本化的本质是农业资本投入的不断增加,金融资源是实现农业资本化的根本保障,只有顺应农业资本化方向的金融资源才可减少无效或低效供给,增加有效或高效供给。本文首先从理论出发论述了金融资源与农业资本化存在相互作用的耦合机制。金融资源通过资本形成机制、技术进步机制和要素替代机制促进农业资本化发展,农业资本化的发展能带来农业生产效率和数量的提高,促进农业经营性收益增加,从而刺激农村地区金融服务产品的需求和供给得到提升,为金融资源总量增加提供累积空间。再基于长江经济带10省市2008—2019年样本数据,通过构建金融资源与农业资本化两大指标体系,运用熵值法和耦合协调度模型对金融资源与农业资本化的耦合协调程度进行实证检验。结果表明,金融资源与农业资本化的发展整体呈上升趋势,但二者存在背离的现象,农村金融资源不足或错配阻碍着金融资源与农业资本化相互促进的良性循环。     

在坚守与转换中思索人性:刘庆邦小说的空间书写

刘庆邦着眼于我国城乡社会结构的变迁,多年来坚持书写农村题材和普通矿工的平凡生活,新世纪以来创作的“保姆在北京”系列小说则将创作视点转移至进城打工的保姆群体,不变的是他对底层百姓的人道主义关怀及对人性问题的深入思索。不论是城乡交叉地带的煤矿叙事所呈现出的物理空间、心理空间和社会空间,还是“保姆在北京”系列小说中空间权力对进城乡下女性的规约与限制,都表现出刘庆邦小说明显的空间意识,也体现了他小说创作的独特价值。     

Generalized Leverage and its Applications

The generalized leverage of an estimator is defined in regression models as a measure of the importance of individual observations. We derive a simple but powerful result, developing an explicit expression for leverage in a general M -estimation problem, of which the maximum likelihood problems are special cases. A variety of applications are considered, most notably to the exponential family non-linear models. The relationship between leverage and local influence is also discussed. Numerical examples are given to illustrate our results     

宽带卫星通信和星际链路间激光通信的应用前景

提出了由于信息化社会、Ｉｎｔｅｒｎｅｔ、Ｉｎｔｒａｎｅｔ和多媒体技术的出现,从而要求卫星通信向多体制、多功能发展。文中着重分析了具有独特优点的激光通信在宽带卫星通信和星际链路中的现实商用前景。     

獭兔养殖综合技术研究

对獭兔的适应性、饲养管理、疾病防治、产品加工等养殖综合技术进行了研究,提出了獭兔的“三改、两杯、两早一分和两选两适”规范化饲养管理制度和疾病综合防治技术措施,探索出了优质獭兔毛皮和“富钙兔肉脯”的加工工艺以及獭兔良种推广的有效途径。     

Marriage selection and age patterns of mortality: a mathematical investigation

"In this paper, we use simulation models to demonstrate the complexity of the relationship between the marriage selection process and the resulting RMRs [relative mortality ratios]. In particular, we show that marriage selection alone can produce a relative mortality ratio which remains large and relatively constant at ages far beyond the marriage span....Our general objective...is to determine the range of age patterns of relative mortality which could, in theory, result from marriage selection on the basis of health characteristics. We also evaluate the effects of variations in the marriage selection mechanisms on the resulting mortality patterns....We develop and apply several simple mathematical models of the marriage selection process. In order to distinguish the potential consequences of marriage selection from marriage protection, we consider hypothetical populations in which causal effects are absent....We begin by considering an extremely simple marriage selection process and subsequently explore a more realistic selection model based on recent death and marriage rates for Japan."     

基于产品创新的管理集成及其实施结构体系研究

本文简单地概括了国内外产品创新中管理集成的研究现状,分析了产品创新中管理集成的内涵,揭示了管理集成与信息集成、过程集成和企业集成等相关概念之间的区别和联系,提出了基于产品创新的管理集成实施的结构体系,指出这个结构体系是由核心层、使能层和技术支撑层构成的,并对其内容进行了详细的阐述。     

新产品市场扩展的宏观技术经济特征:──日、美化工、电气产品的实证研究

本文通过实证研究,揭示发达国家新产品的市场扩展过程。发现新产品伴随一系列技术创新而成长,继而推动相关工业的发展；新产品市场扩展遵循Logistic扩展规律,扩展参数呈现不同的行业分布；虽然经济危机对其产生严重阻扰影响,但新产品扩展具有顽强的规律回复功能。     

Inapproximability and approximability of maximal tree routing and coloring

Let G be a undirected connected graph. Given g groups each being a subset of V(G) and a number of colors, we consider how to find a subgroup of subsets such that there exists a tree interconnecting all vertices in each subset and all trees can be colored properly with given colors (no two trees sharing a common edge receive the same color); the objective is to maximize the number of subsets in the subgroup. This problem arises from the application of multicast communication in all optical networks. In this paper, we first obtain an explicit lower bound on the approximability of this problem and prove Ω(g^1−ε)-inapproximability even when G is a mesh. We then propose a simple greedy algorithm that achieves performance ratio O√|E(G)|, which matches the theoretical bounds. Supported in part by the NSF of China under Grant No. 70221001 and 60373012.