首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   997篇
  免费   33篇
  国内免费   27篇
测绘学   35篇
大气科学   157篇
地球物理   201篇
地质学   262篇
海洋学   262篇
天文学   66篇
综合类   17篇
自然地理   57篇
  2023年   8篇
  2022年   11篇
  2021年   7篇
  2020年   18篇
  2019年   26篇
  2018年   37篇
  2017年   44篇
  2016年   77篇
  2015年   40篇
  2014年   62篇
  2013年   86篇
  2012年   63篇
  2011年   51篇
  2010年   58篇
  2009年   50篇
  2008年   48篇
  2007年   42篇
  2006年   43篇
  2005年   41篇
  2004年   29篇
  2003年   21篇
  2002年   20篇
  2001年   20篇
  2000年   18篇
  1999年   23篇
  1998年   9篇
  1997年   8篇
  1996年   7篇
  1995年   7篇
  1994年   3篇
  1993年   5篇
  1992年   4篇
  1991年   9篇
  1990年   3篇
  1989年   2篇
  1987年   6篇
  1986年   2篇
  1985年   2篇
  1984年   10篇
  1983年   3篇
  1982年   3篇
  1981年   7篇
  1979年   2篇
  1978年   3篇
  1974年   1篇
  1973年   5篇
  1972年   2篇
  1971年   2篇
  1968年   1篇
  1967年   3篇
排序方式: 共有1057条查询结果,搜索用时 15 毫秒
51.
Ocean Science Journal - A carbonic anhydrase VII gene, encoding 277 amino acids, was identified in the intestinal tissue of pufferfish (Takifugu rubripes). The translated protein with an 833-bp...  相似文献   
52.
Bhavya  P. S.  Min  Jun-Oh  Kim  Min-Seob  Jang  Hyo Keun  Kim  Kwanwoo  Kang  Jae Joong  Lee  Jae Hyung  Lee  Dabin  Jo  Naeun  Kim  Myung Joon  Kim  Yejin  Lee  Junbeom  Lee  Chang Hwa  Bae  Hyeonji  Yoo  Hyeju  Park  Sanghoon  Yun  Mi Sun  Lee  Sang Heon 《Ocean Science Journal》2019,54(4):515-528
Ocean Science Journal - Investigations on marine N2 fixation have gained momentum since 1960s with eventual establishments of relevant methodologies to identify species involved and quantify the...  相似文献   
53.
Park  Joo Myun  Jung  Hae Kun  Lee  Chung Il  Huh  Sung-Hoi 《Ocean Science Journal》2019,54(1):141-146
Ocean Science Journal - Diel and gastrointestinal changes in relation to the feeding intensity and prey composition of Apogon lineatus were investigated through the analysis of the diet contents of...  相似文献   
54.
Radiological dirty bombs and improvised nuclear devices pose a significant threat to both public health and national security. Growing networks of radiation sensors have been deployed by a number of offices within the U.S. and international agencies. Detecting such threats while minimizing false alarm rates presents a considerable challenge to homeland security and public health. This research aims to achieve a higher probability of detection with a lower probability of false alarms. It focuses on the local spatial instability of radiation levels in order to detect radioactive materials based on robust outlier detection methods. Our approach includes a three‐step abnormality detection method consisting of one‐dimensional robust outlier detection for all gamma‐ray counts, a density‐based clustering analysis, and a two‐dimensional robust outlier detection method using a bagplot, based on spatial associations. The effectiveness of the method proposed is demonstrated through a case study, wherein radioactive materials are detected in urban environments, and its performance is compared with alternative methods employing a k‐sigma approach, local Getis–Ord () statistic, and the goodness of fit of the Poisson distribution.  相似文献   
55.
56.
57.
In the Saemangeum area, construction of a dike began in 1991 and was completed in 2006; desalination is currently being conducted. In order to investigate  相似文献   
58.
Park  Sojung  Choi  Mansik  Jang  Dongjun  Joe  Dongjin  Park  Kyunggue 《Ocean Science Journal》2020,55(1):49-67
Ocean Science Journal - In this study, we investigated the spatial and temporal distribution and sources of dissolved and particulate heavy metals in Masan Bay, an area that for a long time has...  相似文献   
59.
Various network model creation algorithms have been introduced to demonstrate a better approximation of the actual walking pattern and to provide a better wayfinding guide. However, it is under‐investigated which algorithm creates the most appropriate indoor navigation network model in the context of wayfinding applications. Due to the lack of discussion, some studies unconsciously extended an algorithm designed for creating an outdoor navigation network model to indoor space applications. This is problematic because indoor space has different spatial contexts from outdoor space, such as non‐linear space and no‐designated walking space. Our solution is to select five well‐known algorithms that have been introduced, to reproduce the algorithm for the automated construction of the indoor navigation network model, and to evaluate the applicability of algorithms for indoor wayfinding applications. This article compares the quality of wayfinding results from the output of the indoor navigation network model against two criteria: route efficiency (i.e., length) and route simplicity (i.e., number of directions). Our statistical analysis illustrates that the visibility graph algorithm is the most appropriate for indoor wayfinding applications.  相似文献   
60.
A nonlinear short-wave-averaged (surf beat) model is presented. The model is based on that of Roelvink (1993), but the numerical techniques used in the solution are based on the so-called weighted-averaged flux (WAF) method (eg Watson et al., 1992), with time-operator splitting used for the treatment of some of the source terms. This method allows a small number of computational points to be used, and is particularly efficient in modelling breaking long waves. The short-wave (or primary-wave) energy equation is solved using a more traditional Lax-Wendroff technique. Results of validation indicate that the model performs satisfactorily in most respects.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号