Source mechanisms of twenty-six large, shallow earthquake (M_S ≧ 6.5) during 1980 from P-wave first motion and long-period Rayleigh wave data

Source mechanisms of 26 large shallow earthquakes are determined in terms of a double-couple point source with a correction for the nondirectional part of source finiteness by using P-wave first motions and long-period Rayleigh wave spectra recorded on WWSSN, IDA, and GDSN networks. The combined use of both data sets allows us to determine the double-couple mechanism uniquely in most cases. Constrained linear moment tensor inversion (M_(xz) = M_(yz) = 0) correctly determines the strike of the fault, but fails to estimate the dip, and underestimates the scalar moment. All thrust events along the deep-sea trenches analyzed in this study show nodal planes which dip perpendicular to the trench axis at an angle shallower than 45°. The fit to data of the double-couple inversion is comparable to that of the constrained moment tensor inversion. Using the phase spectra of surface waves we can detect a slow source process with an accuracy of about 10 to 20 sec

Effects of lateral heterogeneity and source process time on the linear moment tensor inversion of long-period Rayleigh waves

Spectra of mantle Rayleigh waves recorded on the IDA network are inverted to determine the seismic moment tensor of the 9 June 1980 California-Mexico Border earthquake, the 29 July 1980 Vanuatu Islands earthquake, and the 9 July 1980 Santa Cruz Islands earthquake. Examinations are made to correct for phase velocity lateral heterogeneity and source process time. A simple regionalization (stable continent, tectonic region, young ocean, and old ocean) improves results of the linear inversion, but the phase correction is not large enough, and the discontinuous change of phase velocity across the boundary between regions causes an artificial rapid change in apparent phase velocity as a function of azimuth. Therefore, a more detailed but gradual representation of the lateral heterogeneity is desirable to correct for the propagation effect in the linear inversion. A source process time which consists of the nondirectional part of the apparent duration of main faulting and the delay time of the faulting from initial break is estimated by a phase analysis of Rayleigh waves. The source process time is generally proportional to the seismic moment on the log-log scale, but some earthquakes deviate considerably from the general relation. Therefore, the measurement of the source process time should be made before the moment tensor inversion. The phase errors introduced by the lateral heterogeneity and source process time may cause a bias to low scalar moment

Numerical Simulations of Two-dimensional Electron Fluid : An Application of Classical-map Hypernetted-chain Method

Based on the mapping introduced by the classical-map hypernetted-chain (CHNC) method, classical numerical simulations, Monte Carlo and molecular dynamics, have been applied to the twodimensional electron fluid and the results are compared with those of quantum Monte Carlo simulations hitherto reported. It is shown that polarization properties of the ground state obtained by the diffusion Monte Carlo method are reproduced within the accuracy of quantum simulations by both of two mapping functions for the quantum temperature which have been proposed within the CHNC method. These results may serve as the basis of numerical simulations based on the CHNC method which are applicable to finite non-periodic systems like quantum dots and systems at finite temperatures

Spin Polarization of Two-Dimensional Electron System in a Finite Domain

We analyze the ground state of the two-dimensional quantum system of electrons confined in a parabolic potential with the system size around 100. We map the system onto a classical system on the basis of the classical-map hypernetted-chain (CHNC) method which has been proven to work in the integral-equation-based analyses of uniform unbounded systems and then apply classical numerical simulations. We find that the confined system undergoes the transition to the spin polarized state with the decrease of the average density and the corresponding critical value is as low as rs ∼ 0.3 in terms of the usual rs parameter estimated for the average density. As the ground state for given value of the rs parameter, our data give the critical value for the transition around 20 which is consistent with the known possibility. The advantage of our method is a direct applicability to geometrically complex systems which are difficult to analyze by integral equations. The application to the structure like quantum dots reported here is the first example of such applications

Coix 属植物の飼料作物化に関する育種学的研究 XVI : New Coix 系統の湛水条件下における形質発現について(農学部門)

栽培環境の変化に伴うNew Coix系統の形質発現の変異と形質間の相関の変動を検討するために, 供試系統を湛水田および畑で栽培し, 標準施肥の3倍量の多肥を与えて形質発現を解析した。水田, 畑両区における形質発現力の差異は, 形質の種類によって異なり, 草丈, 葉面積は施肥量に関係なく畑区がすぐれ, 分げつ数は逆に水田区で増加した。また多肥の効果は概して畑区で強く現われた。一般に環境変化による影響のうけやすい形質の発現力は大きい変動性を示した。水田区の形質発現力は畑区のそれに比べてやや劣るが, なおかなりの生産力を維持しており本系統の耐湿性はかなり強い。New Coix系統間の形質変動性は, 水田区では多肥により増大する形質が多いが, 畑区では逆に減少の傾向が認められた。全試験区を通じて, 草丈, 稈径, 葉厚, 葉面積および花粉稔性の変動性は小さく, 形質発現に安定性が認められる。草丈に対する茎葉諸形質の表現型相関は, 分げつ数を除きいずれの試験区においても高い有意相関を示しており, 遺伝相関はすべて表現型相関を上まわり概して環境相関は低い。草丈と分げつ数との間には, 雑種初期世代で認められたような負の相関は認められない。一般に, New Coix系統の高稈性と多収性にはかなり強い遺伝的関連性があることが推察された。The primary objective of the present study is to analyze the variations of character manifestation and correlation between characters in improved strains of the genus Coix (New Coix strains) cultured in various environmental conditions of field. Six New Coix strains and their parental strains were grown in submerged and upland fields fertilized three times normal amount of manure. The results are summarized as follows : 1) The differences in character manifestation between submerged and upland fields varied with characters. Irrespective of amount of manure, plant height and leaf area in upland field were superior to those in submerged field, and in case of number of tillers the tendency was reversed. Heavy manuring was more effective for character manifestations in general in upland field than in submerged field. Generally, characters which were fluctuable by change of environments varied largely. As the New Coix strains showed fairly high productivities in submerged field in spite of the somewhat inferior character manifestations as compared to those in upland field, the wet endurances of these strains were recognized considerably strong. 2) Variations in many characters due to the differences in strains were increased by heavy manure in submerged field, but they showed a reverse tendency in upland field. The character manifestations of plant height, culm diameter, leaf thickness, leaf area and pollen fertility were considered fairy stable. 3) Significantly high phenotypic correlations were estimated between plant height and some vegitative characters and all the genetic correlations were still higher than those phenotypic correlations, but environmental correlations were generally low. Negative correlation which had been estimated in the early hybrid generations was not recognized between plant height and number of tillers

丹波黒大豆の突然変異育種に関する研究 I : 気乾種子に対するγ線照射の影響(農学部門)

丹波黒大豆(京都1号)の気乾種子を用い, 5∿40KRの^(Co)γ線を照射して, 放射線感受性を検討した。幼苗長は10KRまでは対照区とほとんど差異は認められなかったが, 20KR以上では線量の増加に伴って有意に減少した。これは主として子葉から初生葉までの子葉節長の障害に起因しているものと思われる。開花始は20KRまでは対照区に比べてやや遅延し, 30KR以上では, 2,3日の有意な遅延が認められ, かつ, 分散も大となった。成熟期における諸形質は, 100粒重をのぞいて, 概して線量の増加に伴って減少を示したが, その様相には形質によって差異が認められ, 莢数, 莢重, 粒数および粒重において障害が著しかった。以上の結果から, 丹波黒大豆の放射線感受性は大豆のうちでは概して「中∿やや強」であるものと推察された。Dry seeds of a black soybean, Glycine max (L.) Merr. cv. Tanba-Kuro, with about 11% moisture were given acute gamma radiation exposures of 5,10,15,20,30 and 40KR from a 1,800 Ci ^(Co) source. Seedling height was nearly equal to the control at 10KR and below, while at 20KR and over decreased significantly with increasing doses. We supposed that this decrease resulted from the damage of epicotyl (length between cotyledon and primary leaf). The day of the first flower in individual plants was slightly later than the control at 20KR and below, and was significantly delayed by 2 to 3 days at 30KR and over. Moreover, its variance was larger than the control with increasing doses. Values of some characters in maturing time, in general, was decreased with increasing doses as compared to the control. While the patterns of reduction showed striking differences in some characters, the reduction was severe in the number of pods, pods weight, number of seeds and seeds weight. We assumed that the radiosensitivity of "Tanba-Kuro" held the "middle to semi-resistant" position in soybean

ケイシツ ハツゲン ノ ヘンドウセイ ヨリ ミタ シュウリョウ アンテイセイ ニカンスル ケンキュウ 1 スイトウ ショケイシツ ノ コタイナイ オヨビ コタイカン ヘンドウ リョウ ニツイテ ノウガク ブモン

作物の適応性あるいは収量安定性と諸形質の発現力の変動性との関係を栽培環境条件の変化と関連して考察するために, 水稲12品種を供試して, 密度変化に伴う諸形質の個体内変動量(内CV)と個体間変動量(間CV)の変異について検討した。1) 諸形質の変動性程度は形質の種類によって異なり, 稔性は内, 間両CVともに最も低く, 粒数と収量はかなり高い値を示す。2) 個体内変動と個体間変動とでは, いずれの形質においても内変動の方が大きく, 稔性を除いては, 2倍以上の差異を示している。3) 間CVの分散分析における密度要因は全形質ともに有意であり, 一般に密度変化が変動性に及ぼす影響は, 個体内よりも個体間において強く現われることが認められる。4) 供試品種の栽培地の地域性と個体内変動量との間にはかなり高い関連性が認められ, さらに内CVの分散分析における品種要因はいずれの形質においても有意であり, 個体内の変動性には高い遺伝力が存在するものと思われる。The present paper is the first report of a series of investigation on the relationship between yield stability and variabilities of character manifestaion in connection with differences in environmental conditions. The 12 rice varieties were cultured under three density levels, and the effect of density on the variations which occurred within a plant (Within CV) and between plants (Between CV), was examined. The results are summarized as follows : 1) The degree of variability varied to some extent by the difference in the sort of character. Among all the characters investigated, fertility showed the lowest values in both Within CV and Between CV. Number of kernels and panicle weight, on the other hand, showed high values. 2) The values of Within CV of all the characters except in fertility, amounted more than twice that of Between CV 3) As the result of analysis of variance on Between CV, the density effects were significant in all the characters, and it was recognized that the difference in density influenced more strongly the variability in between plants than that in within a plant. 4) The close relationship was recognized between the locations where those varieties are ordinarily cultured and variation in within a plant. The variety effects were significant in all the characters in the analysis of variance on Within CV, so that it is suggested that there is high heritability on the variability in within a plant

水稲の生産性におよぼすタイヌビエの影響(農学部門)

水稲の生産性におよぼすタイヌビエの影響をみるために, タイヌビエの発生時期や生育期間を人為的に変化させて検討した。すなわち, 熟期の異なる水稲2品種の種々の生育時期にタイヌビエを混植あるいは除草することによって, タイヌビエとの競争による水稲の減収要因を生長解析によって分析した。その結果, いずれの競争区においても水稲の収量は単植区よりも減少し, 両植物の競争期間が長いほど, また, この競争が生起する生育時期が早いほど減収率は大きかった。この収量減を収量構成要素の面よりみれば, 1穂重の減少によるよりも, むしろ穂数減に起因するところが大きく, さらに, 水稲の乾物生産性の面から分析すれば, 生育初期におけるNARと出穂期以後におけるCGRの低下によるものと推察された。一方, 水稲品種の早晩性よりみた場合, タイヌビエの影響は晩生品種におけるよりも早生品種においてかなり大きくあらわれた。The influence of the weed barnyardgrass (Echinochloa crusgalli BEAUV. var. oryzicola OHWI) on the productivity of paddy rice was investigated in relation to emergence time and growing period of the weed. Twelve day-old weed seedlings were transplanted 10,30 and 50 days after transplanting of the two rice varieties which differ in maturity date. The weeds which had been transplanted 10 days after transplanting the rice were hand-weeded at various times. The factors causing reduction in rice yield due to competition with the weed were examined by growth analyses. In all the competition plots rice yield was smaller than in the single cropping plot and, in general, the longer was the competition period of the two plants and the earlier the beginning of the competition, the larger was the yield reduction rate of rice. These reductions of rice yield were caused largely by the decrease in the number of panicles rather than in the panicle weight, and it was infered further that the reductions were attributable to the decrease in net assimilation rate in the early growing stage and in crop growth rate after heading. It was also recognized the influence of the barnyardgrass on the rice productivity was larger in the early-maturing variety than in the late-maturing one

作物の形質発現の変動性よりみた収量安定性に関する研究 II : 水稲諸形質の変動性に対する環境要因の効果について(農学部門)

環境条件の変化に伴う作物の形質の変動性の変異を解析するために, 水稲10品種を3密度, 2作期, 2年次の計12環境条件下で栽培し, 諸形質の個体内変動量(内CV), 個体間変動量(間CV)およびそれぞれの環境間変動量(ECV)の相互関係について考察した。1)内, 間両CVの形質間差異はきわめて大きいが, 各々のECVはいずれの形質においてもほぼ近似した値を示し, 環境変化による両変動性の変異にはほとんど形質間差異が認められない。2)内CVはいずれの形質においても間CVよりも大きいが, そのECVにおいては逆に内CVの方が小さく, さらに分散分析の結果によっても, 内CVに有意性を示す環境要因はほとんど存在しないが, 間CVにおいてはいずれの環境要因もほぼ全形質にわたって有意性を示し, 変動性に対する環境変化の影響は個体内においてよりも個体間において大きく, 両変動性はかなり異なった反応を示している。3)一般に, 形質値と内CV各々のECV間には負の相関を示す傾向が認められ, 形質発現力の環境間変異が大きい品種ほど, 環境変化によるその個体内変動性の変異は小さい。しかし, 内CVと間CV各々のECV間には一定の関係は認められず, 品種別に検討しても, 全形質にわたって特徴のある反応を示す品種は認められない。Variations of variabilities of several characters in rice varieties were studied in relation to difference in environmental conditions. Ten rice varieties were cultured under 12 environments, and the interrelationship among the variabilities which occurred within a plant (Within CV), among plants (Between CV) and the variations of the respective variabilities in environments (ECV) were examined. As for the degrees of variations of Within CV and Between CV, little difference in characters was recognized, although the large difference was detected in both the CV per se. The Within CV was larger than the Between CV in all characters examined. On the other hand, the reverse tendency was shown between the respective ECV. The influence of environmental change was, therefor, larger to the variablilities which occurred among plants than to those within a plant. Negative correlations were shown between both ECV of character values and Within CV, but not clear relation between both ECV of Within CV and Between CV. From these results, it is concluded that both the variabilities which occurred within a plant and among plants respond to the change in environmental conditions by fairly different mechanisms