毕奥-萨伐尔定律是推迟效应忽略下的近似

本文论述毕奥－萨伐尔定律求出的磁场是运动电荷的推迟效应可以忽略下的磁场的近似     

基于随机模糊样本的统计学习理论基础

首先介绍了随机模糊理论的基本内容，进而证明了基于随机模糊样本的统计学习理论的关键定理，且讨论了学习过程一致收敛速度的界，为系统建立不确定样本的统计学习理论并构建相应的支持向量机奠定了理论基础．     

Diversity and life-history traits of wild bees (Insecta: Hymenoptera) in intensive agricultural landscapes in the Rolling Pampa,Argentina

The decline of bees is a major concern due to their vital role in pollinating many crops and wild plants. Some regions in South America, and especially the Pampas, are amongst those parts of the world where stressors of bee populations have been little studied. The Pampas has been intensively transformed for agriculture, being presently one of the most productive areas of agricultural commodities in the world. Here, we aim to provide first insights on the taxonomic and functional composition of bee assemblages in the Rolling Pampa, the most intensively managed part of the Pampas. Soybean (herbicide-tolerant genetically modified varieties) is the predominant crop in this region. Bees were sampled with coloured pan traps. Sampling points were located on field margins in either the cropped or the semi-natural grassland area of a farmland site devoted to annual cropping. A total of 2384 individuals were caught, representing 33 taxa [mainly (morpho)species]. The subgenus Lasioglossum (Dialictus) largely dominated captures (78% of the total abundance) and was relatively abundant in the entire study area, suggesting that some species are likely to reach their ecological requirements in cropped areas. No-till fields and field margins may provide large areas for these below-ground nesting species, while their polylectic food preferences allow them to collect pollen on a wide range of plant species, among them possibly soybean. On the contrary, the richness and the abundance of other taxa were higher in the semi-natural area than in the cropped area. Among them, above-ground nesting or oil-collecting species, which have more specialised nesting and floral requirements, were highly associated with the semi-natural area. Our findings highlight the large dominance of L. (Dialictus) species in this highly intensively managed landscape, and the urgent need of preserving semi-natural habitats to maintain species-rich and functionally diverse bee communities in the Pampas.     

New Neotropical Haplothripini (Thysanoptera: Phlaeothripidae) with a key to Central and South American genera

The tribe Haplothripini includes a large diversity of Thysanoptera–Phlaeothripinae, comprising more than 550 species in about 35 genera. They are characterised by having a maxillary bridge in the head, prosternal basantra well developed and fore wings with a median constriction. Members of this group are present in all geographical regions, but are particularly poorly studied in Central and South America. In this study, we describe a new genus and species, Myrciathrips variabilis gen. et. sp. nov., and a new Haplothrips species; and propose two new combinations: Karnyothrips grassoi (De Santis), and Mirothrips vespicola (De Santis). A key to the nine Haplothripini genera now recognised from Central and South America is provided, together with an updated key to Haplothrips and Mirothrips species. A total of 45 species of Haplothripini are now recognised from Central and South America, and a list of these and their distributions is given. The genera Karnyothrips, Haplothrips and Leptothrips are the most commonly encountered, and some exotic species such as Androthrips ramachandrai and Dolichothrips indicus are now widespread in the Americas.     

Identification of Megaselia scalaris (Loew, 1866) (Diptera: Phoridae) in mummified human body from Itacambira (MG), Brazil,using scanning electron microscopy and cuticular hydrocarbons

Insect puparia were found adhered to the ribs and other tissues in the abdominal cavity of a natural male mummy found in Itacambira (State of Minas Gerais, Brazil) dating to the Colonial Period. They were collected for identification by scanning electron microscopy, and for comparison of several morphological features with those described in the literature. The puparia were found open and dorsoventrally flattened, making it difficult to visualize the dorsal projections. The tegument is covered by tapered spines and contains rows of small tubercles on the dorsal and lateral regions of the puparium. The posterior spiracle consists of four parallel openings arranged in pairs. These results are indicative that the specimens belong to the species Megaselia scalaris (Loew, 1866) (Diptera: Phoridae). Additionally, cuticular hydrocarbons of the puparia were analysed by gas chromatography coupled to mass spectrometry and compared with the profile of M. scalaris reared in the laboratory.     

网络舆情扩散的系统动力学仿真

综合考虑网络舆情扩散的多个环节和主要影响因素,运用系统动力学理论构建了网络舆情扩散的仿真模型,并对仿真结果进行了定性和定量分析。仿真结果表明,通过提高政府公信力、政府服务社会有效性可以有效降低网络舆情扩散程度;而短期内增加社会福利保障资金和加强网络文化宣传力度对降低网络舆情扩散作用力度较小但却可以起到间接抑制作用。     

顶点算子代数模范畴的Grothendick群(英文)

研究了顶点算子代数的模范畴,得到了顶点算子代数的模范畴的Grothendick群及其一些性质,这也为研究顶点算子代数和共形场论提供了一个重要的工具.