全文获取类型
收费全文 | 149篇 |
免费 | 3篇 |
国内免费 | 7篇 |
专业分类
测绘学 | 2篇 |
大气科学 | 12篇 |
地球物理 | 44篇 |
地质学 | 28篇 |
海洋学 | 35篇 |
天文学 | 25篇 |
综合类 | 7篇 |
自然地理 | 6篇 |
出版年
2021年 | 1篇 |
2020年 | 3篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 10篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 8篇 |
2012年 | 5篇 |
2011年 | 7篇 |
2010年 | 1篇 |
2009年 | 9篇 |
2008年 | 9篇 |
2007年 | 7篇 |
2006年 | 6篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 4篇 |
2000年 | 6篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 4篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1971年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有159条查询结果,搜索用时 998 毫秒
61.
Koki Aizawa Yasuo Ogawa Masaaki Mishina Kosuke Takahashi Shintaro Nagaoka Nobumasa Takagi Shin'ya Sakanaka Takuya Miura 《Journal of Volcanology and Geothermal Research》2009,187(1-2):131-139
Magnetotelluric (MT) measurements were conducted at Iwate volcano, across the entirety of the mountain, in 1997, 1999, 2003, 2006, and 2007. The survey line was 18 km in length and oriented E–W, comprising 38 measurements sites. Following 2D inversion, we obtained the resistivity structure to a depth of 4 km. The surface resistive layer (~ several hundreds of meters thick) is underlain by extensive highly conductive zones. Based on drilling data, the bottom of the highly conductive zone is interpreted to represent the 200 °C isotherm, below which (i.e., at higher temperatures) conductive clay minerals (smectite) are rare. The high conductivity is therefore mainly attributed to the presence of hydrothermally altered clay. The focus of this study is a resistive body beneath the Onigajo (West-Iwate) caldera at depths of 0.5–3 km. This body appears to have impeded magmatic fluid ascent during the 1998 volcanic unrest, as inferred from geodetic data. Both tectonic and low-frequency earthquakes are sparsely distributed throughout this resistive body. We interpret this resistive body as a zone of old, solidified intrusive magma with temperatures in excess of 200 °C. Given that a similar relationship between a resistive body and subsurface volcanic activity has been suggested for Asama volcano, structural controls on subsurface magmatic fluid movement may be a common phenomenon at shallow levels beneath volcanoes. 相似文献
62.
63.
Rheological properties and structural changes in different sections of boiled abalone meat 总被引:1,自引:0,他引:1
Ogawa Hiroo 《中国海洋大学学报(英文版)》2003,2(1):44-48
1 Introduction AbaloneHaliotisdiscusisaverypopularfoodthrough outtheworld .WhenAsianpeoples ,notablyJapaneseandChinese ,eatabalonedishes ,theyenjoythefirmtextureoftherawmeatandthetendernessoftheboiledmeat .InJapan ,thetoughervarietiesoftherawabalonemeatareenjoyedandtheabaloneisoftenthin lyslicedandservedraw (sashimi) ,whileinchina ,thetendernessandsoftervarietiesoflesscollagenofboiledmeatareconsideredsuitableforeating ,sotheabaloneisoftenservedbyheating .Infoodscience ,manyreportshavebeen … 相似文献
64.
The -ray and white-light flare of 13 May, 1981 is used for a study of spatial distributions of energetic electrons and high-temperature plasma. 相似文献
65.
A model for diurnal variations of neutral and ionic nitrogen compounds in the thermosphere is reconstructed on the basis of a new photochemical aspect on N(2D), together with new observations of the NO density. The NO density so far measured must be reduced by a factor 2, due to a revision of the fluorescence coefficient for the NO γ-band airglow. Incorporating the quenching reaction of N(2D) with O in the model calculation results in a reduction of the NO density at heights as low as 100 km. These two effects are combined to lead to an evaluation that the N(2D) quantum yield for various possible reactions is as large as 0.9. A smaller rate coefficient for the quenching reaction than that measured in the laboratory, i.e. 1.0 × 10?12cm3sec?1 is favourable for the recent NO observation in the early morning, as well as the observed emission rates of the 5200 A airglow from N(2D) The present model predicts a significant day-to-night variation of N and NO densities at heights above 100 km. Below 100 km, the NO density is fairly stable because of its long chemical time constant. Since the rate coefficient for the conversion of N(4S) to NO is highly temperature dependent, the relative population of N(4S) and NO is very sensitive to the thermospheric temperature variation. Large variations of both N(4S) and NO densities due to the temperature change could occur especially at night. The model is in good agreement with the NO observations so far available in low and middle latitudes, as well as the N observation by the use of a rocket in the twilight. 相似文献
66.
Toshihiro Ogawa 《Planetary and Space Science》1982,30(1):39-44
The intensity ratios of the 1304 Å triplet airglow of atomic oxygen observed by Fastie and Crosswhite (1964) are interpreted on the basis of the radiative transfer formulation for a model with complete frequency redistribution in a Voigt line profile. A model for the fine structure levels in local thermodynamic equilibrium is favorable to the observed intensity ratios, as far as a Voigt profile is applicable. In view of large cross sections as calculated theoretically by Allison and Burke (1969), the mutual relaxation among the 3Pj levels should occur rapidly enough to allow the population in the 3Pj levels to be in thermodynamic equilibrium with the ambient neutral gases. 相似文献
67.
1 Introduction Ultravioletradiationisahighlyactivecomponentofsolarspectrum .Ultravioletradiationhasdetrimentaleffectsonlivingthingsexposedtosunlight ,includingthedestructionofDNA ,proteinsandothermolecules(Harm ,1980 ) ,inhibitionofphotosynthesisandgrow… 相似文献
68.
Silicate to Nitrate Ratio of the Upper Sub-Arctic Pacific and the Bering Sea Basin in Summer: Its Implication for Phytoplankton Dynamics 总被引:2,自引:0,他引:2
Isao Koike Hiroshi Ogawa Toshi Nagata Rumi Fukuda Hideki Fukuda 《Journal of Oceanography》2001,57(3):253-260
Consumption of silicate and nitrate (Si:N molar ratio) in the upper layer of the pelagic subarctic Pacific in summer was evaluated by a regression analysis of silicate vs. nitrate concentrations at the upper 100 m depth. Based on data of three cruises, the pelagic subarctic Pacific can be classified into two groups. First group is characterized by roughly 1:1 consumption of silicate and nitrate, and occupies rather larger area of subarcfic Pacific, i.e., the Gulf of Alaska and the Western Subarctic gyre (averaged slope of Si:N linear regression: 1.21, n = 10 and 1.45, n = 9, respectively). Second group is the regions of the Bering Sea basin and the Oyashio region, and showed higher silicate consumption compared to that of nitrate (averaged slope of Si:N linear regression: 2.14, n = 9 and 2.36, n = 3, respectively). The Si:N difference observed is possibly attributed to relative contribution of diatoms production among the phytoplankton assemblages in the regions, i.e., dominance of diatoms production in the regions of the second group. Higher accumulation of ammonium at the bottom of euphotic layer in the summer Bering Sea basin would also contribute to increase consumption ratio of Si:N amounts. 相似文献
69.
Kazunari Ogawa 《Journal of Oceanography》1974,30(2):54-60
Some experiments were carried out to explain thein situ phenomena that the number of coliform organisms decreased rapidly from estuaries to offshore, and also at deeper layer, and that the appearance of coliform types varied.In natural seawater, experimental results did not show thatEscherichia coli was extinct by self-purification or anti-biosis action of seawater, but it showed that this organism decreased mainly because of their starvation caused by lack of nourishment. Although the decreasing rate of bacterial density was delayed in enriched seawater, addition of nutrient even at the time of bacterial extinction promoted the appearance of variated form of this bacteria with floc formation.Flocculation of bacterial cells was influenced by quality and quantity of added nutrients. Temperature was shown to have an effect on the floc formation, but appearance of variated form in flocculated cells ofE. coli was not affected by temperature. Flocculated particles of coliform bacteria were adsorbed on suspended particles in seawater and precipitated rapidly. This phenomenon seems to be a cause of the rapid disappearance of coliform bacteria in coastal waters.In bottom deposits the coliform bacteria probably survive longer as physiologically variated forms when suitable nutrients were supplied. 相似文献
70.