著者

片野 修 馬場 吉弘 大原 均 河村 功一 佐藤 正人 熊谷 雅之 竹内 基 伊藤 正一 富樫 繁春 井上 信夫

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.61, no.2, pp.97-103, 2014-11-05 (Released:2016-12-25)

参考文献数

28

被引用文献数

2

---

The distribution of Nipponocypris temminckii was investigated in 24 rivers in Nagano, Niigata, Yamagata, Akita, Iwate, and Aomori Prefectures, the species being collected at seven study sites. Amongst non-benthic fishes, N. temminckii was exclusively dominant in two rivers. Supplementary records of the species in Nagano, Niigata, Akita and Iwate Prefectures were also described. Rivers in which investigations had been conducted over two or three years showed an increasing proportion of N. temminckii, indicating successful colonization of the species.

著者

馬場 吉弘 長田 芳和

出版者

The Ichthyological Society of Japan

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.52, no.2, pp.125-132, 2005

---

To clarify the early life history of pale chub, <I>Zacco platypus</I>, and the mechanism for avoiding egg predation, the spawning behaviour, egg and larval distribution in spawning redds, and emergence time of larvae from the redds were investigated in the Saho River, Osaka Prefecture, Japan. In pair spawning, the male applied lateral pressure to the female, and stirred up the river bed with its anal and caudal fins when eggs were released. The female occasionally rotated in the redd at the end of spawning behaviour. Some satellite males and sexunknown individuals occasionally dashed into the spawning redd. Single females averaged 1026.4 mature eggs, spawning 94.5 eggs during each of 10.9 spawning acts per day. The number of eggs released during a single spawning act and buried successfully in the spawning redd following pair spawning was greater than that following spawning with surrounding individuals. More eggs were also found in the spawning redd after the female rotated. Eggs were buried 0-14 cm deep in spawning redds, those resulting from pair spawning being deeper than those from spawning with surrounding individuals. Larvae emerged around midnight from the spawning redd 7-8 days after spawning, emergence continuing for 3-5 days. Females were consid-ered to reduce the risk of egg cannibalism by spawning many times per day, mid-night emergence of larvae also being important for avoiding predation.

著者

片野 修 馬場 吉弘 河村 功一 大原 均

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.62, no.2, pp.99-106, 2015-11-05 (Released:2018-03-26)

参考文献数

30

被引用文献数

3

---

Nonbenthic fishes were investigated in 16 rivers in the Chubu and Tohoku regions, into which pale chub Zacco platypus had been introduced. Pale chub coexisted predominantly with Japanese dace Tribolodon hakonensis, followed by ayu Plecoglossus altivelis altivelis, and were abundant in rivers lacking the latter. Although pale chub, ayu, Japanese dace, dark chub Nipponocypris temminckii and Amur minnow Rhynchocypris lagowskii steindachneri all fed on both benthic algae and invertebrates, the percentage of algae in the diet of pale chub was less when ayu were present. However, the population abundance and diet of pale chub were not affected by the other nonbenthic species. Although pale chub and other cyprinids rarely fed on cyanobacteria, a main food item of ayu, pale chub was considered to be negatively affected by ayu through interference, exploitative competition and indirect effects via changes in algal composition.

著者

宮嵜 悟 石井 勝 馬場 吉弘

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌B(電力・エネルギー部門誌) (ISSN:03854213)

巻号頁・発行日

vol.125, no.5, pp.544-550, 2005 (Released:2005-08-01)

参考文献数

17

被引用文献数

2 1

---

A lightning return stroke model is indispensable in calculating electromagnetic field associated with a return stroke. A lot of return stroke models have been proposed, however, no model has ever succeeded in reproducing all the features of typical electromagnetic field waveforms at various distances. In this paper, two return stroke models are proposed. One is a Transmission-Line type model, and the other is modification of Diendorfer-Uman model. These models successfully reproduce all the features of typical electromagnetic field observed on ground.

著者

久保 佑太 長岡 直人 馬場 吉弘 雨谷 昭弘

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌B(電力・エネルギー部門誌) (ISSN:03854213)

巻号頁・発行日

vol.134, no.2, pp.99-106, 2014-02-01 (Released:2014-02-01)

参考文献数

13

被引用文献数

1

---

A reduction method of a lightning overvoltage on a Power Conditioning System (PCS) is investigated in this paper. The capacitors installed between the circuit and grounding terminal in the PCS determine the response against a first transient. The inductances, winding capacitances and excitation losses of the coils for the filter in the PCS should be also considered for estimating the overvoltage to ground at an input terminal of the PCS. The dominant factors of the maximum overvoltage are a grounding resistance, capacitances between a frame and output terminal of a solar panel and those between the PCS and ground. The overvoltage is decreased with decreasing the grounding resistance of the structure for the solar panels. The grounding resistance of the PCS has a minor effect on the overvoltage. The overvoltage can be reduced when a common grounding method is applied. A length of a cable between the output terminal of the solar panel and the input terminal of the PCS should be as short as possible.