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1.
Makoto Yamada Shinji Ohsawa Kohei Kazahaya Masaya Yasuhara Hiroshi Takahashi Kazuhiro Amita Hideo Mawatari Shin Yoshikawa 《Journal of Geochemical Exploration》2011
To understand deep groundwater flow systems and their interaction with CO2 emanated from magma at depth in a volcanic edifice, deep groundwater samples were collected from hot spring wells in the Aso volcanic area for hydrogen, oxygen and carbon isotope analyses and measurements of the stable carbon isotope ratios and concentrations of dissolved inorganic carbon (DIC). Relations between the stable carbon isotope ratio (δ13CDIC) and DIC concentrations of the sampled waters show that magma-derived CO2 mixed into the deep groundwater. Furthermore, groundwaters of deeper areas, except samples from fumarolic areas, show higher δ13CDIC values. The waters' stable hydrogen and oxygen isotope ratios (δD and δ18O) reflect the meteoric-water origin of that region's deep groundwater. A negative correlation was found between the altitude of the well bottom and the altitude of groundwater recharge as calculated using the equation of the recharge-water line and δD value. This applies especially in the Aso-dani area, where deeper groundwater correlates with higher recharge. Groundwater recharged at high altitude has higher δ13CDIC of than groundwater recharged at low altitude, strongly suggesting that magmatic CO2 is present to a much greater degree in deeper groundwater. These results indicate that magmatic CO2 mixes into deeper groundwater flowing nearer the magma conduit or chamber. 相似文献
2.
Masaya Saitou 《Astrophysics and Space Science》1989,162(1):47-56
Some peculiarities in the behaviour of a model self-gravitating system described by hydrodynamical equations and isothermal equation of state connected with the presence of thermodynamical fluctuations in real systems were investigated in numerical experiment. The values of density and velocity , , respectively, were computed by numerical code perturbed on each time-step and in each computational cell by random values , for modeling such fluctuations. Perturbed values
i
=
i
+
i
,v
i
=
i
+ v
i
were used to initiate the next step of computations. This procedure is equivalent to an introduction into original hydrodynamical equations of Langevin sources which are random functions. It is shown that these small fluctuations (= v =0,2 =v
2 = 10–8) grow many times in marginally-stable state. 相似文献
3.
Previous genetic studies on perch (Perca fluviatilis L.) in northern and southern regions of Europe have shown low heterozygosity. No such investigation has been conducted in the central part of Europe. The genetic variability ofP. fluviatilis in four Swiss lakes (Lake Constance, Lake Zürich, Lake Geneva and Lake Maggiore) was investigated. These four lakes belong to three different drainage systems (Rhine, Rhone and Po) without connections. A total of 136 fish were analysed electrophoretically. Only one locus (SOD
*) was highly polymorphic in Lake Constance among the 27 loci studied. The expected heterozygosities for each population and for the total population were higher than in the previous studies but low (H
S= 0.38–2.7%;H
T=1.22%) and Nei's genetic distances were small (0.000–0.003). However, the jack-knifed mean of the Wright'sF
STwas calculated as 0.142, which indicates modest genetic differentiation among the perch populations in Switzerland, due to the differentiated population in Lake Constance. 相似文献
4.
Masaya Toyokawa Kaoru Aoki Satoshi Yamada Akira Yasuda Yusuke Murata Tomohiko Kikuchi 《Journal of Oceanography》2011,67(2):209-218
We surveyed the distribution of colonies of polyps of Aurelia
aurita sensu lato (s.l.) in Mikawa Bay, Japan. First, we surveyed the distribution of ephyrae of A. aurita s.l. at 75 stations encompassing the whole of Mikawa Bay in early 2008. A total of 37 ephyrae were sampled mostly from fishing
ports. Ephyrae were most abundant around the islands located near the mouth of the bay, and decreased from the western part
to the eastern part of Mikawa Bay. Next, we selected five fishing ports in Mikawa Bay where ephyrae occurred and surveyed
the underside of floating piers and underwater overhangs of wharfs. We found dense colonies of polyps of A. aurita s.l. under nearly all of the floating piers at the two islands located near the mouth of the bay. Fitting a logistic regression
model to the dataset showed that the percentage coverage of Aurelia polyps was significantly greater at the two islands compared with the other locations. In addition, the coverage of Aurelia polyps was greater when the coverage of other fouling organisms was in the range of 65–90%, and the coverage of Aurelia polyps was lower on floating piers with a vinyl surface and on concrete wharfs. The combined distribution of polyp colonies
of A. aurita s.l. in Ise Bay and Mikawa Bay suggested that A. aurita s.l. in the two bays probably forms a single population and shoals of medusae mainly originate from protected harbors along the
mouth-part of the bays. 相似文献
5.
Victor Vladimirovich Orlov Anna V. Petrova Kiyotaka Tanikawa Masaya M. Saito Alija I. Martynova 《Celestial Mechanics and Dynamical Astronomy》2008,100(2):93-120
The rectilinear equal-mass and unequal-mass three-body problems are considered. The first part of the paper is a review that
covers the following items: regularization of the equations of motion, integrable cases, triple collisions and their vicinities,
escapes, periodic orbits and their stability, chaos and regularity of motions. The second part contains the results of our
numerical simulations in this problem. A classification of orbits in correspondence with the following evolution scenarios
is suggested: ejections, escapes, conditional escapes (long ejections), periodic orbits, quasi-stable long-lived systems in
the vicinity of stable periodic orbits, and triple collisions. Homothetic solutions ending by triple collisions and their
dependence on initial parameters are found. We study how the ejection length changes in response to the variation of the triple
approach parameters. Regions of initial conditions are outlined in which escapes occur after a definite number of triple approaches
or a definite time. In the vicinity of a stable Schubart periodic orbit, we reveal a region of initial parameters that corresponds
to trajectories with finite motions. The regular and chaotic structure of the manifold of orbits is mostly defined by this
periodic orbit. We have studied the phase space structure via Poincaré sections. Using these sections and symbolic dynamics,
we study the fine structure of the region of initial conditions, in particular the chaotic scattering region. 相似文献
6.
西北太平洋黑潮主轴区浮游有孔虫的垂直分布及其古海洋学意义 总被引：5，自引：0，他引：5
我们对位于西北太平洋黑潮主轴区ＭＴＤ－０２站的１１个不同深度进行水平浮游拖网,并将采集到的活体浮游有孔虫(＞１２５μｍ)进行定量分析。结果表明,绝大多数活体浮游有孔虫生存于１００～２００ｍ以上的水体中,并集中分布于７５ｍ以上的水体。本站位８月份的最主要属种为：Ｇｌｏｂｉｇｅｒｉｎｏｉｄｅｓｒｕｂｅｒ,Ｇ．ｓａｃｃｕｌｉｆｅｒ,Ｎｅｏｇｌｏｂｏｑｕａｄｒｔｎａｄｕｔｅｒｔｒｅｉ和Ｇｌｏｂｉｇｅｒｉｎｉｔａｇｌｕｔｉｎａｔａ。次主要属种为Ｇｌｏｂｉｇｅｒｉｎｅｌｌａ ａｅｑｕｉｌａｔｅｒａｌｉｓ, ｇｌｏｂｉｇｅｒｉｎａｂｕｌｌｏｉｄｅｓ,Ｐｕｌｌｅｎｉａｔｉｎａｏｂｌｉｑｕｉｌｏｃｕｌａｔａ,Ｇｌｏｂｏｒｏｔａｌｉａｔｒｕｎｃａｔｕｌｉｎｏｉｄｅｓ,Ｏｒｂｕｌｉｎａｕｎｉｖｅｒｓａ和Ｇ．ｃｏｎｇｌｏｂａｔｕａ。这些种在不同的深度其产出量大不相同,但绝大多数均在叶绿素最为丰富的２５ｍ处显示出最大值。这表明食物来源是控制浮游有孔虫在ＭＴＤ－０２站垂直分布的最主要因素。另外,Ｇｌｏｂｉｇｅｒｉｎｅｌｌａａｅｑｕｉｌａｔｅｒａｌｉｓ和Ｐｕｌｌｅｎｉａｔｉｎａｏｂｌｉｑｕｉｌｏｃｕｌａｔａ两个种在温跃层的底部５０ｍ处显 相似文献
7.
Masaya Masayoshi Saito Kiyotaka Tanikawa 《Celestial Mechanics and Dynamical Astronomy》2007,98(2):95-120
The dynamical structure of phase space of gravitational Newtonian three bodies which lie on a line (rectilinear three-body
system) is studied. We take an initial value plane and classify the points on the plane according to the fate of the orbits
starting from the points, using symbol sequences. The structure appearing on the initial value plane with this classification
was well studied for the equal-mass case (Tanikawa and Mikkola 2000, Chaos 10, 649–657). In this paper, we follow and clarify the changes of this structure with the mass ratio of three particles. 相似文献
8.
Masaya Masayoshi Saito Kiyotaka Tanikawa 《Celestial Mechanics and Dynamical Astronomy》2009,103(3):191-207
We study the change of phase space structure of the rectilinear three-body problem when the mass combination is changed. Generally,
periodic orbits bifurcate from the stable Schubart periodic orbit and move radially outward. Among these periodic orbits there
are dominant periodic orbits having rotation number (n − 2)/n with n ≥ 3. We find that the number of dominant periodic orbits is two when n is odd and four when n is even. Dominant periodic orbits have large stable regions in and out of the stability region of the Schubart orbit (Schubart
region), and so they determine the size of the Schubart region and influence the structure of the Poincaré section out of
the Schubart region. Indeed, with the movement of the dominant periodic orbits, part of complicated structure of the Poincaré
section follows these orbits. We find stable periodic orbits which do not bifurcate from the Schubart orbit. 相似文献
9.
Bottom mud was collected from the upper and lower reaches of 92 rivers in Japan to determine the distribution of 0.5N-HCI-soluble
heavy metals. The average concentrations of Cu, Zn, Pb, and Cd in the mud from the lower reaches were from two to three times
higher than those in the upper reaches. Japanese rivers were classified according to the degree of heavy metal pollution by
using the values of 0.5N-HCI-soluble metals in the lower reaches of rivers. The content of 0.5N-HCI-soluble heavy metals in
the mud of the upper reaches was used as the standard value. The classification of rivers was made by a cluster analysis according
to Euclidian distance. As a result, rivers in Japan could be classified into three groups based on the degree of metal pollution,
and the classification was in agreement with the pollution index. 相似文献
10.
Abstract: Synchrotron radiation-induced X–ray fluorescence (SR–XRF) and conventional X-ray fluorescence (XRF) analyses were applied to determine the distributions of iron, manganese, calcium, titanium, and silicon, and chemical forms of iron and trace manganese in three banded iron formation (BIF) samples. The XRF imagings on the weathered and altered BIF from the Cleaverville Formation (3. 3–3. 1 Gyr), Western Australia, showed redistributions of iron, calcium, and manganese with the disappearance of the primary bandings, while, in contrast, titanium preserved its primary depositional distribution. The XRF imagings on the BIF from the Hamersley Group (2. 5 Gyr), Western Australia, showed that manganese and titanium distribute originally at boundary region between the iron-rich mesoband and the silica-rich mesoband. The X-ray Absorption Near Edge Structure (XANES) analysis revealed that the chemical forms of manganese and iron well represent the rhythmic change of the bandings. 相似文献