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Your search keyword '"Nishiyama, Keiichi"' showing total 13 results
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13 results on '"Nishiyama, Keiichi"'

2. Notes on the occurrence and habitat of harvestman Parabeloniscus caudatus Suzuki, 1973 in the Ryukyu Islands, Japan

Author

Nishiyama, Keiichi, Shimada, Taku, Yoshida, Yuzuru, and Tamura, Hisao

Abstract

The harvestman species, Parabeloniscus caudatus Suzuki, 1973 (Opiliones, Epedanidae), has been recorded from Okinawa-jima Island, Miyagi-jima Island and Ikei-jima Island of the central Ryukyus, Japan. This species is considered to be highly dependent on cave environments (Shimojana 1978; 1979). Our survey found new habitats of P. caudatus from Amami-oshima, Tokunoshima and Okinawa-jima islands in the central Ryukyus, Japan. An unidentified Parabeloniscus species has previously been reported from Amami-oshima and Tokunoshima islands, and our study confirmed for the first time that P. caudatus is distributed on these islands. We also found the species under stones in the forests outside caves. A previous study reported the presence of eyeless individuals (Shimojana 1979). The current study also found eyeless individuals from two separate caves., 論文

Published
2019

3. New distributional record of a cave-dwelling spider, Coelotes troglocaecus Shimojana & Nishihira, 2000 (Araneae: Agelenidae), from Miyagi-jima Island, the Ryukyu Islands, Japan

Author

Nishiyama, Keiichi and Nishigaki, Koji

Abstract

A cave-dwelling spider, Coelotes troglocaecus Shimojana & Nishihira, 2000, was newly recorded from Amuji-gama Cave on Miyagi Island, located off Katsuren Peninsula, Okinawa Island, central Ryukyus, Japan, after previously being reported from seven caves on Okinawa Island. This species is characterized by cave-adapted white body color and lack of eyes. This spider has been found from locations where whitened homopteran insects inhabit., 論文

Published
2020

4. Notes on the occurrence and habitat of the freshwater crabs from caves in Okinawa Island, Ryukyu Islands, Japan

Author

Nishiyama, Keiichi

Abstract

沖縄島の7洞窟からヒメユリサワガニGeothelphusa tenuimanus (Miyake & Minei, 1965),オキナワオオサワガニG. grandiovata Naruse, Shokita & Ng, 2006,サカモトサワガニG. sakamotoana (Rathbun, 1905)の3種のサワガニ類が確認された.今回の調査では,洞内でのヒメユリサワガニの放仔のほか,ヒメユリサワガニとオキナワオオサワガニの小型個体が見られるなど,洞内での繁殖に関わる生態が観察された.また,ヒメユリサワガニは体色に個体変異が見られ,大宜味村の洞窟では体色が著しく白化した個体も観察された.また同じ洞窟内では色彩の傾向が類似しており,遺伝的に分化している可能性があった., Three freshwater crab species, Geothelphusa tenuimanus (Miyake & Minei, 1965), G. grandiovata Naruse, Shokita & Ng, 2006, and G. sakamotoana (Rathbun, 1905) were observed from seven caves in Okinawa Island, Ryukyu Islands, Japan. Some reproductive evidence in the caves, such as juvenile-releasing G. tenuimanus and the presence of young individuals of G. tenuimanus and G. grandiovata, were observed. The coloration of G. tenuimanus varied individually, but individuals from the same cave tended to have similar color pattern; and some individuals from Ogimi Village had white body color, suggesting possible genetic isolation., 論文

Published
2018

10. Enthalpies of Combustion of Organic Compounds. IV. Acetanilide and Nicotinic Acid

Author

Sato-Toshima, Tomoko, Kamaguchi, Akeji, Nishiyama, Keiichi, Sakiyama, Minoru, and Seki, Syûzô

Abstract

Standard energies of combustion at 298.15 K have been determined for crystalline acetanilide and nicotinic acid by static oxygen bomb calorimetry. Derived standard enthalpies of combustion and of formation are −(4224.8±1.0) and −(209.5±1.5) kJ mol−1for acetanilide, and −(2730.83±0.48) and −(344.81±0.92) kJ mol−1for nicotinic acid, respectively. Nicotinic acid pellets of 1.2 g in mass showed remarkable tendency to spatter when partially burnt. Factors governing the completeness of combustion of the material have been explored through 28 test combustion experiments.

Published
1983
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11. Thermochemical Studies on Double- and Triple-layered [2.2]Paracyclophanes. Estimation of Molecular Strain Energies.

Author

Nishiyama, Keiichi, Sakiyama, Ninoru, Seki, Syûzô, Horita, Hisanori, Otsubo, Tetsuo, and Misumi, Soichi

Abstract

The measurements of enthalpies of combustion by use of precision oxygen-bomb combustion calorimeter together with the measurement of carbon dioxide recovery were made for double- and triple-layered [2.2]paracyclophanes. The enthalpies of sublimation were also determined by the measurement of temperature dependence of the vapor pressures for the two compounds. The following values are reported for the standard enthalpy of combustion ?Hco(298.15 K)/kJ mol-1and standard enthalpy of sublimation ?Hso(298.15 K)/kJ mol-1, respectively: double-layered [2.2]paracyclophane, 8729.48±1.80, 99.6±1.8; triple-layered [2.2]paracyclophane, 14230.87±3.59, 125.9±2.5. From analyses of the derived standard enthalpy of formation in gaseous state the following two values for total strain energy Us/kJ mol-1of a molecule of triple-layered [2.2]paracyclophane were obtained: 251.9±5.6 with group method and 245.6±9.8 with chemical similarity method, respectively. These values are approximately twice the magnitudes of the corresponding quantities for double-layered [2.2]paracyclophane. From the analysis of the total strain energy by use of the result of Boyd’s molecular mechanical calculation, the contribution from the twisting of the inner benzene ring to the total strain energy of triple-layered [2.2]paracyclophane was estimated to be almost twice that from one outer bent benzene ring.

Published
1980
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