全文获取类型
收费全文 | 109篇 |
免费 | 0篇 |
专业分类
测绘学 | 1篇 |
大气科学 | 1篇 |
地球物理 | 12篇 |
地质学 | 26篇 |
海洋学 | 47篇 |
自然地理 | 22篇 |
出版年
2021年 | 1篇 |
2017年 | 1篇 |
2016年 | 6篇 |
2014年 | 3篇 |
2013年 | 2篇 |
2012年 | 2篇 |
2011年 | 6篇 |
2010年 | 5篇 |
2009年 | 4篇 |
2008年 | 6篇 |
2007年 | 3篇 |
2006年 | 1篇 |
2005年 | 2篇 |
2004年 | 6篇 |
2003年 | 2篇 |
2002年 | 4篇 |
2001年 | 3篇 |
1998年 | 6篇 |
1997年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1974年 | 2篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1967年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有109条查询结果,搜索用时 10 毫秒
91.
Osamu Abe Atsushi Watanabe V. V. S. S. Sarma Yohei Matsui Hiroya Yamano Naohiro Yoshida Toshiro Saino 《Journal of Oceanography》2010,66(3):363-372
We estimated gas exchange rates in Kabira Reef at Ishigaki Island, southwest Japan, using a mass balance calculation with
dual “biological” tracers: dissolved inorganic carbon (DIC) and dissolved oxygen (DO). The nighttime results allowed us to
obtain reasonable gas transfer velocity k
w values, all of which exceeded those obtained in wind-dominant studies. The difference is likely due to the contribution of
turbulence generated by the interaction between the current and bottom topography. The k
w obtained during high tides is consistent with that reported by Raymond and Cole (2001), whereas k
w during low tides is significantly higher, which seems to be caused by enhanced friction with the bottom of the reef and/or
bubble-induced gas transfer by wave breaking at the reef crest. 相似文献
92.
Shingo Kato Kurt Hara Hiroko Kasai Takashi Teramura Michinari Sunamura Jun-ichiro Ishibashi Takeshi Kakegawa Toshiro Yamanaka Hiroyuki Kimura Katsumi Marumo Tetsuro Urabe Akihiko Yamagishi 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(10):1844-1855
Spatial distribution, diversity, and composition of bacterial communities within the shallow sub-seafloor at the deep-sea hydrothermal field of the Suiyo Seamount, Izu-Bonin Arc, Western Pacific Ocean, were investigated. Fluids were sampled from four boreholes in this area. Each borehole was located near or away from active vents, the distance ranging 2–40 m from active vents. In addition, fluids discharging from a natural vent and ambient seawater were sampled in this area. We extracted DNA from each sample, amplified bacterial 16S rRNA genes by PCR, cloned the PCR products and sequenced. The total number of clones analyzed was 348. Most of the detected phylotypes were affiliated with the phylum Proteobacteria, of which the detection frequency in each clone library ranged from 84.6% to 100%. The bacterial community diversity and composition were different between hydrothermal fluids and seawater, between fluids from the boreholes and the vent, and even among fluids from each borehole. The relative abundances of the phylotypes related to Thiomicrospira, Methylobacterium and Sphingomonas were significantly different among fluids from each borehole. The phylotypes related to Thiomicrospira and Alcanivorax were detected in all of the boreholes and vent samples. Our findings provide insights into bacterial communities in the shallow sub-seafloor environments at active deep-sea hydrothermal vent fields. 相似文献
93.
94.
95.
96.
Toshiro Morikiyo 《Contributions to Mineralogy and Petrology》1986,94(2):165-177
Measurements were made of the hydrogen isotope ratios of hydrous silicates (mica and amphibole) and whole rocks, and the carbon isotope ratios of graphite and carbonaceous matter in the metamorphic rocks from the northern Kiso district in central Japan.D values of hydrous silicates in the graphite-bearing metapelites are always higher than those in graphite-free schists, even though the sample localities of the two rock-types are very close. Hydrogen isotopic equilibrium has been attained between the coexisting minerals.D/H ratios of water in the metamorphic fluids seem to depend strongly on the presence or absence of graphite and seem to be not constant throughout the district. The district is divided into three areas of low (metamorphic zones I, II), medium (zones IIIa–V) and high
13Cgr value (zones VIa–VII) areas. In the high
13Cgr values area, the carbon contents of the graphite-bearing rocks decrease slightly from zones VIa to VII, whereas the
13Cgr values increase sharply from the upper part of zone VIa to VIb. TheD values of biotite in these graphite-bearing rocks are higher than those in the medium
13Cgr area. This suggests that methane enriched inH and12C is produced and liberated by the devolatilization reactions between muscovite, graphite and water. The fluid produced is composed of water, methane and a subordinate amount of carbon dioxide, and its logfO2 value is deduced to be about 1.2 lower than that defined by the FMQ buffer. In the medium
13Cgr area, the
13C values of graphite are nearly constant (–20.8), while the Fe2O3/(Fe2O3 + FeO) ratio of the graphite-bearing rocks apparently decreases with increasing metamorphic grade.D differences in hydrous silicates between graphite-bearing and graphite-free rocks are observed. These facts are interpreted to mean that methane was produced in addition to water and carbon dioxide, and that its generation (
ratio of the fluid was about 2) had practically no isotope effect on the graphite. In the low
13Cgr area, the carbon contents of the rocks decrease clearly from zones I to IIIa. TheD and
13Cgr values of the non-metamorphosed shales are much lower than those of the low grade graphite-bearing metapelites. This suggests that methane is produced and liberated from the rocks even at the incipient stage of metamorphism. 相似文献
97.
98.
Takehiko Hiraga Osamu Nishikawa Toshiro Nagase Mizuhiko Akizuki David L. Kohlstedt 《Contributions to Mineralogy and Petrology》2002,143(6):664-672
Interfacial energies of quartz/quartz (qz/qz), albite/albite (ab/ab), and quartz/albite (qz/ab) boundaries in low-grade pelitic schist were determined based on measured values of dihedral angles. Three kinds of microstructures were investigated, and the interfacial energies were obtained in two independent ways. (1) Relative values of interfacial energy were calculated from dihedral angles formed at quartz and albite triple junctions. (2) Subgrain boundary energy was calculated using the Read-Shockley theory for a boundary connected to an intergranular pore. Dihedral angles formed at the corners of intergranular pores were measured. From the interfacial tension balance equation, the value of the qz/qz grain boundary energy was then obtained. (3) Dihedral angles formed at intersections of either pericline or albite twin boundaries with either ab/ab or qz/ab boundaries were measured. The twin boundary energy was calculated based on a previously derived equation using Landau potential, twin wall thickness, and critical temperature for a phase transition in albite. With a modified interfacial tension balance equation for a twin boundary fixed to a facet orientation, the interfacial energies of ab/ab and qz/ab boundaries were obtained. Energies obtained by methods of (2) and (3) are in good agreement. The interfacial energies for qz/qz, ab/ab, and qz/ab boundaries obtained in this study are 270뀶, 300끞, and 250끀 mJ/m2, respectively. 相似文献
99.
Measurements of perturbations in the atmospheric potential gradient around volcanic plumes at multiple (from two to five) sites, and measurements of the charge-mass ratio of ash particles falling from volcanic plumes, were carried out at Sakurajima Volcano, Japan. Results from 28 and 29 October 1995, show that the nature of the perturbations depends on the intensity of plume activity. Although plume activity was vigorous on 28 October, negative perturbations were predominant. As plume activity peaked, the magnitude of negative perturbations decreased just below the plume and increased at an off-axis site. During the peak period, positively charged ash particles fell out from the plume. This suggests that the active plume dominantly contained negatively charged materials, and that positively and negatively charged materials were added to the lower and upper parts of the plume, respectively, during the peak period. On the other hand, as plume activity became less vigorous on 29 October, the perturbations were characterized by a positive anomaly followed by a negative anomaly. Because wind velocity increased with altitude that day, we infer that positive and negative charges were distributed in the upper and lower parts of the plume, respectively. The differences in perturbations observed on 28 and 29 October suggest that volcanic plumes are generally composed of three parts: an upper part with positively charged gas and aerosol, a middle part with negatively charged fine ash particles, and a lower part with positively charged coarse ash particles. The compilation of present and previous results from Sakurajima and other volcanoes indicates that the effect of the negative charge in the middle part was predominant in most cases, although positive perturbations caused by the upper part were observed around some weak plumes. The effect of positively charged particles in the lower part was observable only when plume activity was sufficiently strong because positively charged coarse particles tended to fall out near the vent. 相似文献
100.
To find out the secular and seasonal trends of the 13C value and CO2 concentration in the surface air and the determination of the 13C in the atmospheric CO2 collected at Tsukuba Science City was carried out during the period from July 1981 to October 1983. The monthly average of the 13C value of CO2 in the surface air collected at 1400 LMT ranged from -7.52 to \s-8.45 with an average of -7.96±0.25 and the CO2 concentration in the air varied from 334.5 l 1-1 to 359 l 1-1 with an average of 347.2±6.3 l 1-1. The 13C value is high in summer and low in winter and is negatively correlated with the CO2 concentration. In general, the relationship between the 13C and the CO2 concentration is explainable by a simple mixing model of two different constant carbon isotopic species but the relationship does not always follow the model. The correlation between the 13C value and the CO2 concentration is low during the plant growth season and high at other times. The observed negative deviation of the 13C value from the simple mixing model in the plant growth season is partly due to the isotopic fractionation process which takes place in the land biota. 相似文献