浅析概率统计思想融入数学建模

就如何将概率论与数理统计思想融入数学建模进行探讨,首先简述概率论与数理统计课程特点,及数学建模的发展和应用,其次从教学内容、应用实例等方面进行分析,在此基础上阐述概率统计应用于数学建模的必要性以及实践性,更加说明将概率统计思想融入数学建模是解决很多生活实例的有效方法.     

Mathematical formalisms in scientific practice: From denotation to model-based representation

The present paper argues that ‘mature mathematical formalisms’ play a central role in achieving representation via scientific models. A close discussion of two contemporary accounts of how mathematical models apply—the DDI account (according to which representation depends on the successful interplay of denotation, demonstration and interpretation) and the ‘matching model’ account—reveals shortcomings of each, which, it is argued, suggests that scientific representation may be ineliminably heterogeneous in character. In order to achieve a degree of unification that is compatible with successful representation, scientists often rely on the existence of a ‘mature mathematical formalism’, where the latter refers to a—mathematically formulated and physically interpreted—notational system of locally applicable rules that derive from (but need not be reducible to) fundamental theory. As mathematical formalisms undergo a process of elaboration, enrichment, and entrenchment, they come to embody theoretical, ontological, and methodological commitments and assumptions. Since these are enshrined in the formalism itself, they are no longer readily obvious to either the novice or the proficient user. At the same time as formalisms constrain what may be represented, they also function as inferential and interpretative resources.     

Differing morphology and ultrastructure of the male copulatory apparatus in species-groups of Anagrus Haliday (Hymenoptera: Mymaridae)

Male genitalia of 13 members of the mymarid wasp genus Anagrus have been studied: Anagrus (Anagrella) mymaricornis (Bakkendorf), Anagrus (Paranagrus) unilinearis Soyka, A. (Anagrus) ustulatus Haliday, A. (A.) erythroneurae Trjapitzin and Chiappini, A. (A.) atomus (Linnaeus), A. (A.) aegyptiacus Soyka, A. (A.) vilis Donev, A. (A.) sensillatus Viggiani and Jesu, A. (A.) breviphragma Soyka, A. (A.) incarnatus Haliday, A. (A.) obscurus Förster sensu Soyka, A. (A.) fennicus Soyka and A. (A.) avalae Soyka. Taxonomically significant differences between subgenera and the atomus and incarnatus species-groups are described. The functional significance of various features, and in particular, the arrangment of sensilla are discussed.     

A morphological study of the enteric valves of the Afrotropical Apicotermitinae (Isoptera: Termitidae)

Soil-feeding termites are dominant members of the soil fauna in lowland tropical rainforests. As ecosystem engineers, they have a profound effect on their environment, particularly through modification of the vast quantities of soil that they ingest. There is growing evidence that the processing of the soil in the gut is influenced by the enteric valve--an extremely well-developed feature in the hindgut of the Termitidae, consisting of six ridges, variously armed with spines, teeth and scales. Although this valve has been extensively used in morphological work, little is known of its function. Scanning electron microscopy has been used in this study to better understand the three-dimensional structure of the enteric valve in the Afrotropical Apicotermitinae, a group in which these valves are everted into the following chamber of the hindgut. This configuration lends itself to scanning electron microscopy in a way that it does not in other soil-feeders, since in those species the armature is obscured within the gut lumen. It seems plausible that this structure is instrumental in filtering material through the gut in such a way that the coarse, organic-poor portion of the soil is channeled fast through the centre, while directing the fine, organic-rich portion to the edges for lengthier digestion of recalcitrant plant material. Thus, the enteric valve would appear to be important for the termites to survive on this nutrient-poor but super-abundant food resource.     

Multi-model ensembles in climate science: Mathematical structures and expert judgements

Projections of future climate change cannot rely on a single model. It has become common to rely on multiple simulations generated by Multi-Model Ensembles (MMEs), especially to quantify the uncertainty about what would constitute an adequate model structure. But, as Parker points out (2018), one of the remaining philosophically interesting questions is: “How can ensemble studies be designed so that they probe uncertainty in desired ways?” This paper offers two interpretations of what General Circulation Models (GCMs) are and how MMEs made of GCMs should be designed. In the first interpretation, models are combinations of modules and parameterisations; an MME is obtained by “plugging and playing” with interchangeable modules and parameterisations. In the second interpretation, models are aggregations of expert judgements that result from a history of epistemic decisions made by scientists about the choice of representations; an MME is a sampling of expert judgements from modelling teams. We argue that, while the two interpretations involve distinct domains from philosophy of science and social epistemology, they both could be used in a complementary manner in order to explore ways of designing better MMEs.     

Rediscovery of Gastrostyla setifera (Engelmann, 1862) Kent, 1882: morphology and divisional morphogenesis (Ciliophora,Hypotrichida)

The morphology and morphogenesis of the poorly known hypotrichous ciliate Gastrostyla setifera, isolated from a freshwater pond near Harbin, China, are described from both living and protargol silver-impregnated specimens. The Harbin population of this species is characterized thus: medium-sized freshwater Gastrostyla, 150-205 × 70-95 μm in vivo, ellipsoid in shape but somewhat narrowed posteriorly. Contractile vacuole located in left half of mid-body region. On average 48-56 (mean 52) adoral membranelles; 10 frontal and 9-11 ventral cirri; 23-26 left and 30-34 right marginal cirri; usually with four complete dorsal kineties and two dorsomarginal kineties; three caudal cirri present at posterior margin; invariably two macronuclear nodules and two micronuclei. Its morphogenesis reveals the following characteristics: (1) adoral zone of membranelles (AZM) in the opisthe arises from the new oral primordium while the proter inherits the entire parental structure; (2) 10 frontal, 9-11 ventral and five transverse cirri are derived from five frontoventral transverse cirral anlagen together with the undulating membrane anlage; (3) left and right marginal cirri are derived from new anlagen which originate within the old marginal rows; (4) the generation of the dorsal kineties is of the 'two-group-mode'; three left primary dorsal anlagen and two dorsomarginal anlagen appear as two groups in both dividers from which all dorsal kineties are derived (the fourth kinety is formed due to the fragmentation of the third anlage); (5) one caudal cirrus is formed at the ends of each of the first, second and fourth dorsal anlagen.     

Comparison of Anuropus branchiatus Beddard and A. bathypelagicus Menzies & Dow

Summary

The discovery of Serolis tropica sp. nov. in the shallow shelf zone of the Pacific of Panamá, just south of 9°N latitude, establishes the first occurrence of the Serolidae in tropical American waters. Since gravid females were found in cool as well as warm thermal seasons, it is assumed that this species is adapted to live under tropical conditions. Serolis yongei, known from the Great Barrier Reef, was collected at a depth of 200 m. It is not presently known if this species, like S. tropica, also inhabits the shallow shelf where warm-water conditions prevail.

Serolis tropica, a member of the North American ‘carinata’ group, is related to the ‘marplatensis’ group of South America. While it is argued that these two groups must have shared a common history, the remaining region of approximately 40° latitude between the northern and southern forms greatly complicates the relationship. Whether or not this gap is real or due to a lack of fine, inshore sampling can only be determined by further field work in this region.     

水飞蓟种子（果实）形态学及萌发特性研究

系统地对水飞蓟种子进行了形态学和萌发特性的研究,实验结果表明：种子的千粒重分别是18.88 g和21.14 g.长度分别是0.66 cm,0.68 cm,厚度分别是0.16 cm,0.20 cm,宽度分别是0.26 cm,0.28 cm.哈师大植物园的水飞蓟种子在25℃时萌发率较高为90％.绥化中学的水飞蓟种子用赤霉素处理,结果100 ppm处理过的种子在25℃时萌发的比较好,萌发率为48％.     

黎曼猜想什么时候会被证明出来?

首先从对数学猜想证明的理解得出了影响证明数学猜想的两个重要因素,即数学猜想的证明依赖于必要的数学进展和合适的数学家;接着对这两个因素进行分析;由于对黎曼猜想的证明来说,无论是所需要的数学知识和方法是否具备还是是否有合适的数学家二者都是不确定的,因而无法肯定该猜想什么时候才能被证明出来。