著者
小西 真衣
出版者
特定非営利活動法人 緑地雑草科学研究所
雑誌
草と緑 (ISSN:21858977)
巻号頁・発行日
vol.2, pp.29-35, 2010 (Released:2017-06-30)
参考文献数
14

セイタカアワダチソウが分布を急速に広げたのは戦後であり、その分布は人間生活圏の周囲に集中している。種子は非常に小さく軽く風で飛ばされ、根茎は地下の浅いところに水平方向に張り巡らされている。純群落の地上部は、高密度でバイオマスが大きく、相対照度が非常に小さいので他の草が入り込むことは不可能となる。ロゼットで越冬し、越冬ロゼットは4月に入ると急速に伸長する。種子からの生育は遅いため、速やかに地下部を発達させロゼットを形成し翌春の生長に備えることが、群落を形成・維持するうえで非常に重要である。刈り取りの効果には、時期によって異なる光合成産物の振り分け先が関係する。1970年代には本種の有害性や、時には善悪についての「セイタカアワダチソウ論争」ともいえる大論争が起こったが、この騒ぎがきっかけとなり多くの自治体で問題雑草の対策を義務付けるようになり市街地の雑草繁茂状況がかなり改善されたのである。
著者
門田 誠一
出版者
佛教大学歴史学部
雑誌
歴史学部論集 (ISSN:21854203)
巻号頁・発行日
vol.6, pp.43-54, 2016-03-01

魏志倭人伝記の記述のなかでも、もっとも史料性が高いとされるのが魏の皇帝から卑弥呼に与えられた詔書の部分であり、そこに記された下賜品のうち「金八両」に関して、漢魏における金の使用のなかで把握するとともに、具体的な斤量を推定した。あわせて、文献・史料と出土遺物の双方から金製品を多数かつ多量に用いた匈奴と比して、考古資料からも金の使用が顕著でない倭に対しては、魏から少量の金しか与えられておらず、金の下賜に関する倭と匈奴との相違を示した。これらによって、漢代から三国時代にかけての金使用の衰退とあわせて、卑弥呼に対する黄金の下賜は漢代以降の中国における賜金を主体とした金使用の変化に対応しており、さらには金を重用しないという倭の具体的な習俗を認知したうえで行われた魏の現実に即した賜物であったと結論した。魏志倭人伝卑弥呼金八両魏賜金
著者
尾西 明生 松木 正義 小林 直樹
出版者
The Society of Resource Geology
雑誌
鉱山地質 (ISSN:00265209)
巻号頁・発行日
vol.23, no.118, pp.119-136, 1973-05-25 (Released:2009-06-12)
参考文献数
19

The oldest rocks of the Hirase mine area are various gneissose and granitic rocks of the so-called Hida Complex. They crop out in the northeastern and southwestern parts of this area. The Jurassic to Cretaceous Tedori Formation overlies these rocks uncomformably in the southwestern part of this area. The Cretaceous Nohi Rhyolites Group is most extensively distributed in this area. It is composed of acidic welded tuffs intercalated with rhyolite lava, its tuff and tuff breccia, and mudstone.Granitic rocks, K-Ar ages of which are about 60 m.y., intrude the Nohi rhyolites. They crop out as several. stocks along the Sho-gawa (river) and are called "Shirakawa Granites." Fine-to medium-grained biotite granite and hornblende-biotite granodiorite are their major facies. The Shirakawa granitic rocks show contact aureoles in the surrounding Nohi rhyolites. Andalusite-bearing assemblage is seen around some of the plutons, such as Hatogaya and Hirase stocks. Dykes of quartz diorite porphyry, hornblende andesite, pyroxene andesite and basalt occur in these stocks mainly along fault zones.Metamorphic rocks of the Hida complex thrust up to the Nohi rhyolites along the Morimo tectonic line. It strikes north-northwest. A similar fault zone passing through the Mihoro dum reservoir is called "Mihoro tectonic line." There are many faults of NW-trend diversing from the Mihoro tectonic line, some of which cut throngh the Hirase granitic stock.There are many kinds of mineral deposits in the area, namely Cu-Pb-Zn veins in the Fcdori formation, Au-Ag quartz veins in the Nohi rhyolite, graphite deposits in the Hida complex and molybdenite-quartz veins in the Shirakawa stocks. Yet, only molybdenum deposits, those of the Hirase mine in particular, are productive. The Hirase mine is one of the most important molybdenite mines in Japan.The Hirase deposits are composed of 29 molybdenite-quartz veins. The veins strike N-S to NNE and dip steeply west. Productive veins occur in the marginal part of the Hirase stock. The granitic rocks of this part are very heterogeneous and become homogenous toward the interior. The veins also become poor or thin out in the interior.Molybdenite occurs along walls of quartz veins as fine-grained crystals or very coarse-grained cuhedral ones. The latter predominates in drusy parts of the quartz veins and accompanies coarse-grained calcite crystals in some places. Molybdenite seams occur in some parts of the altered Nohi rhyolites. Molybdenum grade of this ore is very low, 100 to 200 ppm, but the quantity is large. The amount of MoS2 in the altered rhyolites at Kitani (about 3 km north of the Hirase mine) is estimated about twice as much as the total historical production of the Hirase mine. Molybdenites in any mode of occurrence have been recognized in rocks between the Morimo and Mihoro tectonic lines.
著者
冨井 眞
出版者
考古学研究会
雑誌
考古学研究 (ISSN:03869148)
巻号頁・発行日
vol.62, no.4, pp.49-70, 2016

京都盆地東北部に所在する古墳時代中期の吉田二本松古墳群の8号墳の同溝から出土した埴輪に対し, 破片化の原因を を解明するため, 原位置論的な分析と破壊力学的なな検討をした。まず, 埴輸の分布域に基づき, 埴輪が破片化する以前の樹立景観を推定復元した。次に高残存率の6個体に対し破片の原位置情報と元の完形状態に状態における部位とを対照するとともに, 割れを生んだ衝撃の強さや伝達方向を持合破片の接着線から検討し, 破損と埋没の過程を復元的に論じた。その結果, この古墳の墳丘と埴輪は人為的に破壊されたことを導き出した。そして, 遺溝の切り合い関係と, 埴輪の器面の遺存状態から, その破壊が古墳時代に遡りえる可能性を指摘した。Aiming at providing a way to understand the process and reason for breakage of archaeological remains prior to excavation, this paper examines, as a case study, how and why haniwa figures of the middle Kofun period (late 5th century AD) which were recently excavated from ditches at the No. 8 burial of the Y oshida-Nihonmatsu burial cluster in the northeast part of the Kyoto basin, were fragmented. The basic method is composed of both provenancial, or in situ, analysis, and fracture mechanism study. At first, based on the distribution of the fragments of haniwa figures, the original landscape of the burial with haniwa decoration is reconstructed. Then, each of the six, best preserved cylindrical and house-shaped haniwa figures is investigated in order to reconstruct the processes of both the breakage and deposition of these figures by collating the provenancial information of its largest cluster of sherds with their original position within the figure before breakage. And subsequently by reading the fracture lines to speculate the extent and/ or strength of loading to the body of the figure. This inductive approach can demonstrate that both the burial mound and its decorating haniwa figures were intentionally destroyed, at least in some parts. by people of the past Additionally, this destruction can be dated back to the Kofun period (6-7th century) as the fill of the ditch of other burials in the same cluster' is overlapped by a posthole of a Nara period structure, and because the degree of weathering of the surface of these haniwa figures is far lower than that of many others recovered from burials that were destroyed during the Nara period in other areas
著者
三宅 陽一
出版者
The Society for Reproduction and Development
雑誌
Journal of Reproduction and Development (ISSN:09168818)
巻号頁・発行日
vol.42, no.6, pp.j111-j118, 1996 (Released:2010-10-20)

これまでに家畜には多くの染色体異常例があり,それが繁殖障害と密接に関連していることを報告した.今回,それらの結果をもとに,染色体異常例は以下の4つの型に区分されるものと考えた.すなわち,A群は染色体の形態に異常があり相対的不妊症を示すもの(転座,逆位);B群は染色体の形態は正常であるが絶対的不妊症を示すもの(XY female,間性);C群は染色体数の増減があり絶対的不妊症を示すもの(トリソミー,モノソミー);D群は性染色体のキメラが認められ絶対的な不妊症を示すもの(フリーマーチン)である.今後,このような染色体異常例は家畜の遺伝子(群)の機能を解析するうえで,格好のモデルになるものと思われる.
著者
西川 寿勝
出版者
古代学協会
雑誌
古代文化 = Cultura antiqua (ISSN:00459232)
巻号頁・発行日
vol.68, no.3, pp.365-372, 2016-12
著者
沢 俊行
出版者
日経BP社
雑誌
日経メカニカル (ISSN:03863638)
巻号頁・発行日
no.565, pp.92-104, 2001-10

本章で扱う「平板」のイメージは,圧力容器や下水配管に設けたマンホールのふたやエンジンのシリンダヘッドなどだ。この種の平板は機械構造物に常用されているが,その設計の際には,板厚をいくらにすべきか作用荷重に対して壊れないかたわみはいくらになるか内圧が変動する圧力容器の配管系などに使用したときには共振しないか—と,色々心配してしまう。
著者
小早川 みどり
出版者
日本魚類学会
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
vol.39, no.1, pp.25-36, 1992-06-15 (Released:2010-06-28)
参考文献数
15

日本産のナマズ3種ナマズ (Silurus asotus), イワトコナマズ (S. lithophilus), ビワコオオナマズ (S. biwaensis) の成体の頭蓋と懸垂骨を比較し, それらの発生を記載した.稚魚期の成長の速いビワコオオナマズでは, 他2種に比べ化骨の時期が早く, 上後頭骨の矢状隆起の発達の度合いや, 翼耳骨の側上方への反り返りが大きく, 懸垂骨にみられる筋付着突起の発達も著しかった.
著者
友田 淑郎
出版者
日本魚類学会
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
vol.8, no.5-6, pp.126-146, 1962-06-30 (Released:2010-06-28)
参考文献数
33

1) Comparative studies have been made on the three species of the genus Parasilurus found found in Lake Biwa-ko, both from the morphological and the ecological points of view. Proportions are examined for various parts of body, and the external characters of sensory organs and of certain feeding organs are scrutinized.2) The results obtained from these studies may be summarized as follows: in P. biwaensis, the development of external sensory organs is rather poor except for eyes, and the body as a whole is adapted for pelagic carnivorous life ; in P. lithophilus, sensory organs are well developed, and the body is adapted to a good extent for rupicolous life ; in P. asotus, two pairs of heavy barbels present, whereas the eyes are degenerated, and the body is adapted for bottom life in shallow turbid water.3) Percentages of the lengths of eight body parts against standard length are illustrated in graphs, and the types of their growths are compared. It may be seen from these graphs that specific difference is hardly found in some characters but is notable in the others. Moreover, the latter characters become divergent among species according to their growths.4) Irrespective of superficial variability of P. asotus, its specific peculiarity has become evident after many characters have been examined as a combination. Such a combination of characters is always peculiar to P. asotus and is correlated with the mode of its life, though respective characters are not stable according to the difference in external factors. Not giving proper consideration for ecological data, we might fail in realizing the accurate status of P. asotus, being only perplexed by its variable faces.5) Besides the differences mentioned above, there is another type of differenti ation among the species found in Lake Biwa-ko. This is the discrepancy in vomerine tooth-band, whose shape is always fixed in each species. The difference is, however, variable to a considerable extent in specimens taken from waters other than Lake Biwa-ko.6) Mere comparisons of specimens from various localities are of little importance, unless studies on habitats and life will be carried out. Future investigations in this line should be necessary on such problematical species of the genus Parasilurus as are spread over the Asiatic Continent.7) In clarifying the origin of the three species occurring in Lake Biwa-ko, it is necessary to investigate the topographical histories of the habitats of the respective species, besides researches for their habitats of the present day.8) It may be needed to conduct in future investigations on the developmental stages (etap) of the fishes.