全文获取类型
收费全文 | 134篇 |
免费 | 4篇 |
国内免费 | 3篇 |
专业分类
大气科学 | 13篇 |
地球物理 | 36篇 |
地质学 | 31篇 |
海洋学 | 43篇 |
天文学 | 12篇 |
综合类 | 2篇 |
自然地理 | 4篇 |
出版年
2024年 | 2篇 |
2023年 | 1篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 7篇 |
2015年 | 5篇 |
2014年 | 5篇 |
2013年 | 3篇 |
2012年 | 3篇 |
2011年 | 9篇 |
2010年 | 3篇 |
2009年 | 8篇 |
2008年 | 13篇 |
2007年 | 7篇 |
2006年 | 2篇 |
2005年 | 4篇 |
2004年 | 6篇 |
2003年 | 8篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1976年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有141条查询结果,搜索用时 15 毫秒
101.
Yoshisuke Nakano 《Advances in water resources》1983,6(4):205-213
Similarity solutions to the second boundary value problem of unsaturated flow are studied in one-dimensional, semi-infinite porous media with the soil-water diffusivity proportional to some power of the water content. The existence and uniqueness of two types of similarity solutions to the problem are investigated and the properties of these solutions are presented. It is shown that these two types of similarity solutions exist and that they may not be unique for every parameter range studied. The use of the similarity solutions is discussed for the experimental determination of soil-water diffusivity. 相似文献
102.
103.
104.
Takanori Sato Nobuaki Tanaka Anand Nainar Koichiro Kuraji Mie Gomyo Haruhiko Suzuki 《水文科学杂志》2020,65(13):2322-2335
ABSTRACT Many studies have focused on soil erosion in unmanaged Japanese cypress plantations because the sparse understory vegetation and litter covering the forest ground enhance soil erosion. In this study, soil erosion, litter, and overland flow measurements were conducted over 14 months to identify the spatio-temporal variation and examine the optimal sample size. Fifteen traps (each 0.25 m wide) were installed in line along the bottom of a 15-m-wide slope. Soil erosion and overland flow had large spatial variations as compared to litter. The temporal coefficient of variation of soil erosion and overland flow was highest during dry seasons, while smaller during wet seasons. The random sampling analysis showed that the rate of decrease in spatio-temporal variation became moderate as the sample size increased beyond six. This result indicated that the optimal sample size was five, the total width of which was equivalent to about 8% of the monitored slope width. 相似文献
105.
Evaluation of the coupled heat transfer, water flow and stress changes in the engineered clay barrier is an important issue in the performance assessment of the high‐level radioactive waste disposal. To demonstrate the function of the engineered barrier system, the large‐scale experiment is conducted, which is called Big Bentonite facility (BIG‐BEN). The facility consists of an electric heater surrounded by glass beads, carbon steel overpack, buffer material and man‐made rock. The buffer is a mixture of bentonite and sand. The heater is operated at 0·8 kW. Water is injected from the interface between the buffer and the man‐made rocks at the pressure of 0·05 MPa. The duration of the experiment is 20 months. The change in temperature and swelling pressure are continuously monitored and gravimetric water content is measured by sampling. The coupled thermal, hydraulic and mechanical processes are simulated with a finite element code THAMES, which can simulate the fully coupled phenomena in the saturated and unsaturated clay under anisothermal condition. To examine the validity of the code, all the parameters used in the model are evaluated from the other laboratory tests. The simulated results are compared with the measured ones without calibration of the parameter values using the results from the BIG‐BEN experiment. It can be concluded that the changes in temperature and gravimetric water content within the buffer can be simulated reasonably well and that the mechanical effect such as swelling pressure is difficult to realize. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
106.
Sato Minoru Oba Takashi Hosokawa Takao Yamaguchi Toshiyasu Nakano Toshiki Saito Tadao Muramoto Koji Kahara Takashi Funayama Katsura Kobayashi Akio Nakano Takahisa 《中国海洋大学学报(英文版)》2005,4(3)
1 IntroductionIncreased blood pressure appears to be one of theprimary risk factors of circulatory organ diseases suchas encepharo-apoplexy, encepharo-infarction and cardi-ac infraction. Angiotensin-I-converting enzyme (ACE)plays an important role in the rennin-angiotensin sys-tem by regulating blood pressure. Antihypertensivedrugs such as captopril and enalapril are potent ACEinhibitors (Ondetti et al., 1977). Recently, severalinhibitory peptides derived from food proteins havebeen isolat… 相似文献
107.
Seasonal variations in coastal debris on Awaji Island, Japan 总被引:1,自引:1,他引:0
Shimizu T Nakai J Nakajima K Kozai N Takahashi G Matsumoto M Kikui J 《Marine pollution bulletin》2008,57(1-5):182-186
The subject of our study was Awaji Island, an island located in the west of Japan that is surrounded by sea and that has serious problems relating to coastal debris. We conducted a long-term investigation focusing on three beaches and evaluated the results. The study was designed to develop an understanding of the actual situation, to inform local citizens, and raise their concerns about the problem of debris with a view to taking action against it. We obtained the following results: the amount, type, and ratio of debris changed according to weather and ocean conditions; debris also differs according to geographical conditions; social and economic activities of the surrounding area influence the type of debris encountered. Following this study, we have continued our investigation, and are continuing to gather data. At the same time, it is important to spread our ideas and enlighten people so as to encourage them not to dump debris. We hope that these actions manage to raise the level of consciousness among local citizens and to expand their anti-debris activities. 相似文献
108.
Internal microtextures of ternary alkali feldspars in sanidine trachyte from Oki-Dogo Island were examined using an electron microprobe analyzer, a scanning electron microscope, a transmission electron microscope and cathodoluminescence instruments, to develop the understanding of volcanic processes of alkaline magmas related to feldspar crystallization. The examined trachyte is an evolved rock of the Oki-Dogo Pliocene trachyte group. Its phenocryst feldspars are commonly associated with lamellar-wavy-domain textures with scales approximately from 100 nm up to several hundreds of μm that show complex and gradual variations in composition: however, anti-rapakivi zoning textures common in other Oki-Dogo alkaline rocks are almost completely absent in the trachyte. These textures are produced by extensive magmatic ion-exchange replacement reactions progressively advanced in the evolved magma. Characteristic braided fluorite alignments are developed consistently with lamellar-wavy-domain textures in phenocryst feldspars, and similar braided alignments are also present in groundmass feldspars with complicated microtextures. Most of fluorite grains are <100 nm in diameter, and the patterns of braided fluorite alignments vary greatly in individual feldspars. The whole occurrence of the feldspar microtextures represents an extreme example of diffusion-controlled replacement reactions, progressively advanced in the dry (relatively anhydrous) trachyte magma. The genetic processes forming fluorite alignments in feldspars are related to magma compositions, especially F and P contents, and the crystallization of F-bearing minerals, especially of fluorapatite. 相似文献
109.
110.
Baba Sotaro Osanai Yasuhito Adachi Tatsuro Nakano Nobuhiko Hokada Tomokazu Toyoshima Tsuyoshi 《Mineralogy and Petrology》2019,113(6):821-845
Mineralogy and Petrology - In this paper, we describe the metamorphic conditions of Fe-rich granulite and variations in rare earth elements (REE) between peak garnet porphyroblasts and secondary... 相似文献