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排序方式: 共有162条查询结果,搜索用时 15 毫秒
51.
52.
Miyamoto H Yano H Scheeres DJ Abe S Barnouin-Jha O Cheng AF Demura H Gaskell RW Hirata N Ishiguro M Michikami T Nakamura AM Nakamura R Saito J Sasaki S 《Science (New York, N.Y.)》2007,316(5827):1011-1014
High-resolution images of the surface of asteroid Itokawa from the Hayabusa mission reveal it to be covered with unconsolidated millimeter-sized and larger gravels. Locations and morphologic characteristics of this gravel indicate that Itokawa has experienced considerable vibrations, which have triggered global-scale granular processes in its dry, vacuum, microgravity environment. These processes likely include granular convection, landslide-like granular migrations, and particle sorting, resulting in the segregation of the fine gravels into areas of potential lows. Granular processes become major resurfacing processes because of Itokawa's small size, implying that they can occur on other small asteroids should those have regolith. 相似文献
53.
Munehide Ishiguro 《Soil Science and Plant Nutrition》2005,51(5):637-640
Allophanic Andisols have a significant pH-dependent charge. The positive charge increases and the negative charge decreases as pH decreases; therefore, anion movement becomes slower and cation movement becomes faster as pH decreases in the soil. At low pH, soil dispersion occurs easily due to electric repulsive force. The permeability of the soil then decreases because of structural changes that occur when dilute HCl or HNO3 is percolated in the soil. However, soil permeability does not decrease when dilute H2 SO4 is percolated in the soil. This is because SO4 2- strongly adsorbs on the soil surface at low pH and the soil remains flocculated. 相似文献
54.
Soichi?TanakaEmail author Yuko?Fujiwara Yoshihisa?Fujii Shogo?Okumura Hiroyoshi?Togo Naoya?Kukutsu Tadao?Nagatsuma 《Journal of Wood Science》2011,57(3):189-194
The attenuation coefficients of 100-GHz millimeter waves polarized linearly were measured for cross-cut, quarter-sawn, and
flat-sawn boards of hinoki (Chamaecyparis obtusa) that were 0.2–2.0 cm thick. This was done to examine the applicability of free-wave propagation theory for applying electromagnetic
waves to wood. It was found that the transmittance of a millimeter wave through the specimen boards was lower when the fiber
direction of a board was parallel to the direction of the electric field of the incident wave than when the fiber direction
was perpendicular to the electric field, and there was little difference in the transmittance between the tangential and radial
directions for the former case. These findings can be quantitatively explained by using propagation theory and the dielectric
properties of wood. 相似文献
55.
Culture and climate change: Japanese cherry blossom festivals and stakeholders’ knowledge and attitudes about global climate change 总被引:1,自引:0,他引:1
Ryo Sakurai Susan K. Jacobson Hiromi Kobori Richard Primack Kohei Oka Naoya Komatsu Ryo Machida 《Biological conservation》2011,(1):654-658
Most global climate change models predict serious ecological and social problems. In Japan, biologists have found climate change is affecting species and ecosystems, including the earlier flowering time of cherry trees which are an important cultural symbol in Japan. Cherry blossom festivals are also important to local economies. This study explored the perceptions of Japanese residents regarding climate change impacts on culturally significant events such as flower timing of cherry trees. We conducted interviews of stakeholders of three cherry blossom festivals, including sixteen organizers of festivals and 26 managers of festival-dependent businesses, to understand their awareness, attitudes and behaviors toward global climate change and impacts on cherry blossom festivals. Most organizers of the festival in Kakunodate were concerned about global warming and its impact on cherry blossom times while organizers of festivals in Nakano and Komoro felt it was unimportant if flower timing affected the festival schedule. Most (92%) managers of festival-dependent businesses mentioned that global warming is occurring and affecting the flower timing of cherry trees, but there were diverse perceptions of global warming impacts on their business. Managers more dependent on income from cherry blossom festivals indicated greater concern for the effects of climate change. 相似文献
56.
Sassa Y Yamamoto H Mochizuki M Umemura T Horiuchi M Ishiguro N Miyazawa T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(4):491-494
Feline parvoviruses were isolated from frozen samples of intestines taken from a snow leopard (Uncia uncia) and a serval (Leptailurus serval) that died successively at Sapporo Maruyama Zoo in Hokkaido, Japan. Isolates possessed an antigenic epitope for both the feline panleukopenia virus (FPLV) and mink enteritis virus, identified with a hemagglutination inhibition test. Sequencing analyses of the VP2 region of the isolates revealed that the two isolates were identical and of the FPLV-type. These results suggested that FPLV was introduced from a feral cat which entered the zoo and transmitted the virus inside the zoo. 相似文献
57.
58.
Kitao N Yahata T Matsumoto T Okamatsu-Ogura Y Omachi A Kimura K Saito M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(10):1065-1068
Uncoupling protein 1 (UCP1) is present exclusively in brown adipose tissue, and contributes to body temperature control during cold exposure. We cloned UCP1 cDNA of plateau pika (Ochotona dauurica), a small, non-hibernating, diurnal lagomorph that inhabits in relatively cold climates and at high altitudes in Mongolia and in northern China. The nucleotide sequence of pika UCP1 was highly homologous to UCP1 of other species, and the deduced amino acid sequence had some common domains for UCP, including six mitochondrial carrier protein motifs and a putative purine-nucleotide binding site. RT-PCR and Western blot analyses revealed that both UCP1 mRNA and protein were expressed exclusively in the interscapular adipose tissue. These results suggest that pika UCP1 contributes to heat production in brown adipose tissue, as do those in other species. 相似文献
59.
60.
Frequencies of PrP genotypes in meat breeds of Japanese sheep and trail of selective breeding in experimental sheep flock 总被引:1,自引:0,他引:1
Ohara J Togari T Kurokawa A Maeda J Ishiguro N Furuoka H Horiuchi M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(12):1325-1329
The selection of sheep with scrapie-resistant PrP genotypes is one of the control measures for transmissible spongiform encephalopathies in ruminants. In this study, we investigated the frequencies of PrP genotypes in meat breeds in Japan. The nationwide surveillance revealed that nearly half of the Suffolk sheep, a major meat breed in Japan, carried scrapie-susceptible AQ/AQ and AQ/VQ genotypes. In addition, the VQ haplotype, which confers high susceptibility to scrapie within sheep, was also found in Poll Dorset sheep. A trial of selective breeding using sires with scrapie-resistant PrP genotypes AQ/AR and AR/AR could raise the ratio of scrapie-resistant sheep from less than 50% to 80% within 3 years. However, the use of sires with the AR/AR genotype and the selection of ewes would be required to achieve a higher ratio of scrapie-resistant sheep. 相似文献