Wyniki wyszukiwania - Biblioteka Nauki

1

Characteristics of journal bearings lubricated with ferro-fluid

100%

Harada M. , Yang W. , Tsukazaki J. , Yamamoto H.

Applied Mechanics and Engineering

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1999

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tom Vol. 4, no spec.

33-38

EN

This paper presents a hydrodynamic lubrication theory for journal bearings lubricated with ferro-fluid. A two-dimensional lubrication equation considering the magnetic force, the angular momentum of particle and the change of the apparent viscosity depend on the magnetic fields is proposed. According to this equation, the characteristics of the finite length journal bearings lubricated with ferro-fluid are investigated.

2

Influence of atmospheric gas upon seizure of gas bearings

100%

Karpov P. , Harada M. , Tsukazaki J. , Yamamoto H.

International Journal of Applied Mechanics and Engineering

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2004

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tom Vol. 9, no spec.

105-109

EN

In this paper the influences of atmospheric gas such as oxygen or argon upon seizure are investigated. The hydrostatic journal bearings are used as a test apparatus. Oxygen and argon were used as a lubricant in bearing test process. Bronze bearings finished by lapping are used under the combination with steel shafts finished by honing. It was clarified that the process of gas makes an important role for frictional force, origin of debris and the seizure. On the other hand, plastic deformation of the asperities of surface roughness by rubbing action seemed to be a main reason for seizure of similar materials of steel. The surface finishing influences upon the origin of debris and the seizure superior to atmospheric gas.

3

Taxonomic study of the water shrews Chimarrogale himalayica and C. platycephala

75%

Motokawa M. , Harada M. , Apin L. , Yasuma S. , Yuan S. L. , Lin L. K.

Acta Theriologica

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2006

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tom 51

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nr 2

215-223

EN

We investigated karyotypes, mitochondrial cytochromeb gene sequences, and cranial morphometries of the water shrewsChimarrogale himalayica (Gray, 1842) andC. platycephala (Temminck, 1842) (Insectivora, Soricidae). Karyotypes ofC. himalayica from Taiwan andC. platycephala are 2n=52 and FNa=100. Autosomes consisted of 21 large-to-small metacentric or submetacentric pairs, and 4 medium-to-small subtelocentric pairs. The X and Y chromosomes were medium submetacentric and small acrocentric, respectively. The karyotypes ofC. himalayica andC. platycephala were very similar. Secondary constrictions were observed in the largest metacentric pair in both species. In the 930 base-pairs of the cytochromeb gene,C. himalayica from Taiwan andC. platycephala diverged with 9.46% sequence difference; each species diverged fromC. phaeura with more than 14% sequence difference. The two speciesC. himalayica andC. platycephala were well distinguished by morphometric characters, but three subspecies ofC. himalayica were not clearly separated. We suggest thatC. platycephala be treated as a valid species and separated fromC. himalayica in Taiwan.

4

Comparative chromosomal studies in Rhinolophus formosae and R. luctus from china and Vietnam: elevation of R. l. lanosus to species rank

63%

Volleth M. , So N. T. , Wu Y. , Li Y. , Yu W. , Lin L.-K. , Arai S. , Trifonov V. , Liehr T. , Harada M.

Acta Chiropterologica

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2017

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tom 19

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nr 1

EN

For the majority of Rhinolophus species a karyotype consisting of either 58 or 62 chromosomes was reported. The members of the R. trifoliatus clade are therefore distinguished from other rhinolophids by low diploid chromosome numbers (2n) and a high rate of chromosomal changes. Recently, based on cytogenetic characters, a cryptic species, R. luctoides, was described and a subspecies, R. luctusmorio, was elevated to species rank. In the present work, the karyotypes of a male bat from Vietnam and a female one from China, both classified as R. luctus by morphological characters, were studied by G-banding and fluorescence in situ hybridization with whole chromosome painting probes derived from Aselliscus stoliczkanus. In the male specimen from Vietnam, the composition of the 15 autosomal bi-armed pairs (2n = 32, FN = 60) is identical to that of R. luctoides from Malaysia. For reason of differences in body size and baculum length as well as in skull morphology, this specimen is provisionally treated as R. cf. luctoides. The karyotype of the female specimen from Sichuan province, China, differs from R. luctoides by a whole arm reciprocal translocation resulting in an altered arm composition of pairs 3 and 4. For this reason, the elevation of the Chinese subspecies of R. luctus, i.e. R. lanosus, to species rank is suggested. The karyotype of the endemic Taiwanese species R. formosae with a diploid number of 2n = 52 is mainly composed of acrocentric autosomal pairs. Of the five bi-armed pairs, only the two smallest show the same arm composition as found in the 2n = 32 karyotypes of other members of the R. trifoliatus clade. The composition of the remaining three bi-armed pairs is unique and represents an apomorphic feature for R. formosae.

5

A new species of the genus Murina (Chiroptera: Vespertilionidae) from the Central Highlands of Vietnam with a review of the subfamily Murininae in Vietnam

63%

Son N. T. , Csorba G. , Tu V. T. , Thong V. D. , Wu Y. , Harada M. , Oshida T. , Endo H. , Motokawa M.

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nr 2

EN

The subfamily Murininae has high species diversity in Vietnam, but taxonomic studies are limited. In this paper, we describe a new species of the genus Murina based on a specimen collected from Ngoc Linh Nature Reserve, Kon Tum Province in the Central Highlands of Vietnam. It is a medium-sized species with ‘suilla-type’ dentition. A taxonomic review of Murininae from Vietnam was also conducted based on combined morphological, DNA, and karyological characteristics. Molecular phylogenetic analyses based on the mitochondrial cytochrome c oxidase subunit (COI) gene supported the subfamily Murininae, while the genus Murina proved to be paraphyletic in relation to the genera Harpiocephalus and Harpiola. Fourteen species of the genus Murina, one species of Harpiocephalus, and one species of Harpiola are recognized from Vietnam. Murina tiensa is regarded as a junior synonym of M. harrisoni; strong sexual dimorphism was observed in M. harrisoni. Relations between forearm length and total length of skull showed different trends among species and sexes. Karyotypes of Murina huttoni, M. cyclotis, M. lorelieae, M. beelzebub, M. feae, and Harpiola isodon were 2n = 44, FN = 50, while that of Harpiocephalus harpia was 2n = 44, FN = 52.