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   25188篇
  免费   1849篇
  国内免费   78篇
耳鼻咽喉   380篇
儿科学   671篇
妇产科学   530篇
基础医学   3103篇
口腔科学   277篇
临床医学   2629篇
内科学   5350篇
皮肤病学   489篇
神经病学   2253篇
特种医学   1198篇
外科学   4157篇
综合类   258篇
一般理论   23篇
预防医学   1824篇
眼科学   410篇
药学   1817篇
中国医学   29篇
肿瘤学   1717篇
  2023年   292篇
  2022年   555篇
  2021年   1126篇
  2020年   628篇
  2019年   946篇
  2018年   1047篇
  2017年   709篇
  2016年   737篇
  2015年   922篇
  2014年   1176篇
  2013年   1466篇
  2012年   2116篇
  2011年   2164篇
  2010年   1152篇
  2009年   914篇
  2008年   1422篇
  2007年   1432篇
  2006年   1348篇
  2005年   1185篇
  2004年   1050篇
  2003年   898篇
  2002年   801篇
  2001年   261篇
  2000年   176篇
  1999年   208篇
  1998年   145篇
  1997年   111篇
  1996年   110篇
  1995年   77篇
  1994年   65篇
  1993年   61篇
  1992年   127篇
  1991年   106篇
  1990年   99篇
  1989年   105篇
  1988年   76篇
  1987年   92篇
  1986年   83篇
  1985年   81篇
  1984年   71篇
  1983年   58篇
  1982年   54篇
  1981年   62篇
  1980年   44篇
  1979年   53篇
  1978年   46篇
  1974年   38篇
  1973年   56篇
  1972年   50篇
  1970年   39篇
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
101.
102.
103.
Kallmann syndrome is a genetic disorder with the hallmarks of anosmia and hypogonadotrophic hypogonadism. It has a male preponderance. With the elucidation of the genetic pathways involved, affected females and inheritance patterns are becoming more clearly identified. It is an eminently treatable disorder, but it must first be recognized by the physician. With treatment, favorable reproductive outcomes can be attained in addition to maturation of secondary sex characteristics.  相似文献   
104.
105.
106.
107.
108.
109.
Recovery of zinc and manganese from scrapped alkaline batteries were carried out in the following way: leaching in H2SO4 and selective precipitation of zinc and manganese by alkalization/neutralization. As a result of non-selective leaching, 95.6–99.7% Zn was leached and 83.7–99.3% Mn was leached. A critical technological parameter is the liquid/solid treatment (l/s) ratio, which should be at least 20 mL∙g−1. Selective leaching, which allows the leaching of zinc only, takes place with a leaching yield of 84.8–98.5% Zn, with minimal manganese co-leaching, 0.7–12.3%. The optimal H2SO4 concentration is 0.25 mol∙L−1. Precipitation of zinc and manganese from the solution after non-selective leaching, with the use of NaOH at pH = 13, and then with H2SO4 to pH = 9, turned out to be ineffective: the manganese concentrate contained 19.9 wt.% Zn and zinc concentrate, and 21.46 wt.% Mn. Better selectivity results were obtained if zinc was precipitated from the solution after selective leaching: at pH = 6.5, 90% of Zn precipitated, and only 2% manganese. Moreover, the obtained concentrate contained over 90% of ZnO. The precipitation of zinc with sodium phosphate and sodium carbonate is non-selective, despite its relatively high efficiency: up to 93.70% of Zn and 4.48–93.18% of Mn and up to 95.22% of Zn and 19.55–99.71% Mn, respectively for Na3PO4 and Na2CO3. Recovered zinc and manganese compounds could have commercial values with suitable refining processes.  相似文献   
110.
In the numerical analysis of manufacturing processes of metal parts, many material properties depending on, for example, the temperature or stress state, must be taken into account. Often these data are dependent on the temperature changes over time. Strongly non-linear material property relationships are usually represented using diagrams. In numerical calculations, these diagrams are analyzed in order to take into account the coupling between the properties. An example of these types of material properties is the dependence of the kinetics of phase transformations in the solid state on the rate and history of temperature change. In literature, these data are visualized Continuous Heating Transformation (CHT) and Continuous Cooling Transformation (CCT) diagrams. Therefore, it can be concluded that time series analysis is important in numerical modeling. This analysis can also be performed using neural networks. This work presents a new approach to storing and analyzing the data contained in the discussed CCT diagrams. The application of Long-Short-Term Memory (LSTM) neural networks and their architecture to determine the correct values of phase fractions depending on the history of temperature change was analyzed. Moreover, an area of research was elements that determine what type of information should be stored by LSTM network coefficients, e.g., whether the network should store information about changes of single phase transformations, or whether it would be better to extract data from differences between several networks with similar architecture. The purpose of the studied network is strongly different from typical applications of artificial neural networks. The main goal of the network was to store information (even by overfitting the network) rather than some form of generalization that allows computation for unknown cases. Therefore, the authors primarily investigated in the ability of the layer-based LSTM network to store nonlinear time series data. The analyses presented in this paper are an extension of the issues presented in the paper entitled “Model of the Austenite Decomposition during Cooling of the Medium Carbon Steel Using LSTM Recurrent Neural Network”.  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