加入WTO与我国畜牧业发展

阐述了加入WTO对我国畜牧业发展的积极影响,以及对我国畜产品市场的影响,在此基础上提出我国畜牧业发展的思路、政策、措施:一是调整发展思路;二是深化畜牧经济体制改革;三是加大立法、执法力度,提高畜产品质量;四是实现畜牧业的产业化经营;五是强化畜牧业发展扶持力度.     

弱电统一规范理论中的费曼规则

在R-ε规范条件下,导出了规范场、希格斯场、规范固定项及鬼场的拉格朗日密度,并据此给出了弱电统一规范理论中的费曼规则.     

基于随机占优准则的山岳型景区游客感知测评研究——以中华五岳为例

游客感知是旅游者对旅游体验的认识和评价结果,关乎其旅游决策和满意度,对于山岳型景区的可持续发展有着重要意义。文中以中华五岳为例,利用第三方平台数据并基于随机占优准则和PROMETHEE-Ⅱ法对山岳型景区游客感知进行研究。结果表明:游客对于五岳景区生态环境和文化底蕴的评价较高,而对于景区管理和服务意识的评价偏低,并且针对个别影响因素出现了不同的游客体验倾向。在此基础上,利用实地考察对数据结果进行验证,提出五岳景区需针对其短板做出不同的改进策略,因地制宜对各景区进行整改完善,真正做到可持续、稳定地发展,这对提升山岳型景区形象及落实可持续发展具有重要意义。     

国家法与民间规则互动中的土地产权选择——兼论“特别法人”制度进入《民法典》

土地的空间固着特性与人的所有权心理存在着天然的矛盾，土地法因此经常表现出国家法与民间规则的互动。这种互动既是土地的公共职能与经济属性、个人使用与公众利用之间的不同追求所造成的，同时也是土地价值的多重性决定的。将土地产权设为公共所有可以协调土地多重价值与"所有"心理之间的关系、可以限制制度冲突的空间，从而保持制度的稳定，以此平衡土地的多重价值并及时对制度的发展方向做出调整。《民法典》因其稳定性和权威性而对较为成熟的规则作出规定，但"特别法人"作为集体经济组织的主体却是一项新的制度。土地公共所有及其主体归属的理论仍需进一步沉淀。     

What controls fish functional diversity patterns in Colombian Andean streams?

Understanding the mechanisms that structure communities have been a major challenge in ecological theory. Functional trait-based approaches are increasingly used for studying the processes underlying community assembly. However, species-poor systems of Andean streams these processes are largely unknown. Tropical Andean streams are highly variable in space-time and characterised by the harsh or stable environment, resulting in a high taxonomic and ecological diversity. In this study, we tested the influence of environmental variables on the fish functional structure. We proposed that in ecosystems with harsh environments, environmental filtering will structure fish assemblages, and in ecosystems with a more stable environment, limiting similarity will prevail, increasing functional diversity. We analysed fish assemblages using functional diversity indices, fourth-corner RLQ analyses and multiple regression models. Environmental variables such as altitude, stream width, sub-Andean vegetation and pH influenced functional diversity. For instance, high values of functional redundancy were registered at high elevation streams, reflecting fish assemblages composed of highly dominant species with similar functional traits such as species of the genus Astroblepus. However, we found differences between Astroblepus species in the number and distance of gill rakers which might indicate resource partitioning and coexistence. On the other hand, our results show both stochastic dynamics and environmental filtering are structuring fish assemblages in low and high elevation Andean streams respectively.     

公司治理结构与多元化投资——来自中国上市公司的经验证据

运用KMV模型计算违约距离，作为度量我国上市公司信用风险的指标，并利用Apriori算法挖掘上市公司之间的信用风险传染。结果表明关联规则挖掘能直观有效地描述上市公司之间的信用风险传染，产生强关联规则的上市公司之间信用风险传染较为明显。     

月季白粉病的发生规律及防治措施

月季白粉病是由蔷薇单丝壳菌引起的病害，繁殖力强，传播速度快，严重影响月季的生长及观赏价值。本文介绍了月季白粉病的危害症状、形态特性、发病规律和影响因素，并提出了具体的综合防治措施，以期为有效防治月季白粉病、促进月季生长和提高月季观赏价值提供参考。     

关联规则挖掘的优化算法

频繁项集挖掘是关联规则挖掘的核心部分，目前大多数关于关联规则挖掘的研究都集中于如何提高频繁项集挖掘的效率，然而在实际应用中，决策者面对的是最终从频繁项集中生成的规则集，因此优化规则的生成过程及生成规则同样值得重视。本文提出频繁项集的子集树这一模式来生成关联规则，不仅简化规则的生成过程还可缩小决策者面对的规则集，更便于规则的增量更新。     

An approach to land-use planning in a hilly watershed using geographical information system

The eco-socio-economic balance of a region can be preserved by proper land-use planning, particularly in hilly watersheds where erosion caused by rainfall is an ever-present threat. This paper describes a methodology developed to compile a treatment-oriented land-use planning scheme for a hilly watershed using a geographical information system (GIS). A remote sensing based physiographic soils map and a digital elevation model (DEM) are the sources of soil depth and slope steepness classes, respectively, and are the information databases for GIS analysis. The GIS was used to integrate these databases and provide tools for manipulation of the data. A set of knowledge-based rules was formed from the classification scheme formulated by Sheng and Stennett (1975) for hilly watersheds, modified to allow for the local land-use patterns. These rules were used to manipulate the databases and allow the establishment of a sustained land-use system in the watershed with proper soil and water conservation measures. This biological engineering scheme would be a safeguard against soil erosion and other environmental threats. A priority sub-watersheds delineation survey conducted in the watershed indicates significant variation in the silt yield index values, which calls for conservation planning in earnest in cases of high and very high priority sub-watersheds.