Variational Approach to the Thomas-Fermi Equation

By the semi-inverse method, a variational principle is obtained for the Thomas-Fermi equation, then the Ritz method is applied to solve an analytical solution, which is a much simpler and more efficient method.

Dynamic analysis of arrest of buckle propagation on a beam on a nonlinear elastic foundation by FEM

Based on the dynamic governing equation of propagating buckle on a beam on a nonlinear elastic foundation, this paper deals with an important problem of buckle arrest by combining the FEM with a time integration technique. A new conclusion completely different from that by the quasi-static analysis about the buckle arrestor design is drawn. This shows that the inertia of the beam cannot be ignored in the analysis under consideration, especially when the buckle propagation is suddenly stopped by the arrestors.

On the velocity of buckle propagation in a beam on a nonlinear elastic-foundation

The paper revisits a simple beam model used by Chater et al. (1983, Proc. IUTAM Symp. Collapse, Cambridge University Press) to examine the dynamics of propagating buckles on it. It was found that, if a buckle is initiated at a constant pressure higher than the propagation pressure of the model (P-p), the buckle accelerates and gradually reaches a constant velocity which depends upon the pressure, while if it is initiated at P-p, the buckle propagates at a velocity which depends upon the initial imperfection. The causes for the difference are also investigated.

Mitochondrial cytochrome b gene sequence diversity in the Korean hare, Lepus coreanus Thomas (Mammalia, Lagomorpha)

Partial sequences of the mitochondrial cytochrome b gene of the Korean hare (Lepus coreanus) were analyzed to determine the degree of genetic diversity. Nine haPlotyes were observed, and the maximum Tamura-Nei nucleotide distance among them was 2.8%, indicating that genetic diversity of L. coreanus is moderate. In order to clarify the Korean hare's taxonomic status and relationship with the Manchurian hare (L. mandshuricus) and the Chinese hare (L. sinensis), these nine haplotypes of the Korean hare were compared with 13 haplotypes from five other species of eastern Asian Lepus including L. mandshwicus and L. sinensis. The Korean hare was distinct in its cytochrome b gene, and it is confirmed that L. coreanus is a valid species, as noted by Jones and Johnson (1965, Univ. Kansas Publ. (Mus. Nat. Hist.) 16:357). Further analyses of mtDNA cytochrome b gene with additional specimens of L. coreanus from North Korea and other species of Lepus from eastern Asia are needed to clarify the taxonomic status of the divergent mtDNA clades of L. mandshuricus and L. sinensis.

Species diversity of the subgenus Amiota (s. str.) Loew, 1862 (Diptera, Drosophilidae) in southern China

A total of 38 Amiota (s. str.) species (about 40% of the world total) are reported from southern China, with descriptions of 23 new species, i.e. sinuata species-group: aculeata Chen and Aotsuka, sp. nov., subsinuata Chen and Aotsuka, sp. nov., xishuangbanna Chen and Aotsuka, sp. nov.; basdeni species-group: brevipartita Chen and Gao, sp. nov., curvispina Chen and Gao, sp. nov., lipingae Chen and Gao, sp. nov., huae Chen and Gao, sp. nov., longispina Chen and Gao, sp. nov.; taurusata species-group: asymmetrica Chen and Takamori, sp. nov.; femorata Chen and Takamori, sp. nov., yixiangensis Chen and Takamori, sp. nov.; alboguttata species-group: ailaoshanensis Chen and Watabe, sp. nov., arcuata Chen and Watabe, sp. nov., dehiscentia Chen and Watabe, sp. nov., jizushanensis Chen and Watabe, sp. nov., latitabula Chen and Watabe, sp. nov., luguhuensis Chen and Watabe, sp. nov., nozawai Chen and Watabe, sp. nov., paraspinata Chen and Watabe, sp. nov., shangrila Chen and Watabe, sp. nov.; and ungrouped: fuscicata Chen and Zhang, sp. nov., wangi Chen and Zhang, sp. nov., wuyishanensis Chen and Zhang, sp. nov. A key to all species from southern China is provided. The Amiota fauna of southern China at the species-group level is compared with that of six geographic regions. The subgenus Amiota is assumed to have originated and produced many species-groups in the Oriental region of East Asia, and then the basdeni, alboguttata and rufescens species-groups might have spread to Europe and North-Central America throughout the Palearctic region of East Asia and both the apodemata, sinuata and nagatai species-groups to tropical regions of South-East Asia.

亚洲南部球果蝠Sphaerias blanfordi(Thomas,1891)的亚种分化

球果蝠Sphaerias blanfordi(Thomas,1891)是亚洲南部喜马拉雅-印度支那地区的特有种,甚为罕见而少有报道.曾被认为是单型种,几乎无雄性特征的描述.蔡桂全和张遁治(1980)根据采自西藏东南部墨脱的2只雄性标本订了一亚种一墨脱亚种Sphaerias blanfordi motuoensis,其主要特征是颈下侧有一对灰黄色的圆形毛斑.中国科学院昆明动物研究所先后在云南西北部高黎贡山地区采获25号标本(9♂♂,16♀♀),发现球果蝠两性在外形上有明显的性别差异,雄性的颈下侧有一对圆形、灰黄色的刷状毛斑,但雌性均无;对比墨脱标本,认为墨脱亚种的鉴别特征不可靠,亚种不能成立.Lunde(2003)曾报道采自越南北部Mt.Tay Con Linh Ⅱ地区的43号标本,其前臂长和上犬齿外宽明显与印度、缅甸和云南西北部高黎贡山地区的标本不同,可能是真正的地理亚种.

Geographic variation of the Anderson's Niviventer (Niviventer andersoni) (Thomas, 1911) (Rodentia: Muridae) of two new subspecies in China verified with cranial morphometric variables and pelage characteristics

A total of 66 specimens of Niviventer andersoni with intact skulls was investigated on pelage characteristics and cranial morphometric variables. The data were subjected to principal component analyses as well as to discriminant analyses, and measurement

瘦尾细额溞Oxyurella tenuicaudis(Sars,1862)的若干生物学特征

瘦尾细额溞是一种出现数量极其稀少的枝角类。关于它的生物学特征尚未见诸文献。本文测量了一次采自云南永胜一池塘的本种300个两性个体的体长和怀卵量,就其幼体与成体的数量、体长与怀卵量、雄性以及性比等问题探讨了种群的生物学状况。 详细观察比较了这个种的重要分类特征——雌体后腹部,并描述了变异范围。对卵鞍和雄体也作了描述。