全文获取类型
收费全文 | 3083篇 |
免费 | 264篇 |
国内免费 | 326篇 |
专业分类
化学 | 292篇 |
晶体学 | 2篇 |
力学 | 321篇 |
综合类 | 116篇 |
数学 | 2338篇 |
物理学 | 604篇 |
出版年
2024年 | 6篇 |
2023年 | 16篇 |
2022年 | 44篇 |
2021年 | 40篇 |
2020年 | 63篇 |
2019年 | 44篇 |
2018年 | 58篇 |
2017年 | 72篇 |
2016年 | 102篇 |
2015年 | 64篇 |
2014年 | 124篇 |
2013年 | 191篇 |
2012年 | 172篇 |
2011年 | 205篇 |
2010年 | 184篇 |
2009年 | 225篇 |
2008年 | 218篇 |
2007年 | 240篇 |
2006年 | 212篇 |
2005年 | 174篇 |
2004年 | 148篇 |
2003年 | 157篇 |
2002年 | 117篇 |
2001年 | 114篇 |
2000年 | 93篇 |
1999年 | 93篇 |
1998年 | 97篇 |
1997年 | 73篇 |
1996年 | 59篇 |
1995年 | 34篇 |
1994年 | 37篇 |
1993年 | 31篇 |
1992年 | 31篇 |
1991年 | 17篇 |
1990年 | 10篇 |
1989年 | 13篇 |
1988年 | 10篇 |
1987年 | 6篇 |
1986年 | 9篇 |
1985年 | 12篇 |
1984年 | 9篇 |
1983年 | 8篇 |
1982年 | 11篇 |
1981年 | 8篇 |
1980年 | 10篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1971年 | 1篇 |
1936年 | 2篇 |
排序方式: 共有3673条查询结果,搜索用时 13 毫秒
851.
糖尿病人微量元素谱的多元分析 总被引:1,自引:0,他引:1
胜多元分析了糖尿病患者样品中微量元素,了解微量元素与糖尿病的关系,并提出了新见解。用ICP-AES测定糖尿病患者血、发中18种微量和宏量元素 ;结果经多元分析处理,找到血、发共有的相关链:Mn-Ni-Cu-SrTi,它与患者年龄、性别、样品无关,看来它提供了机体的特殊信息。 相似文献
852.
Previous results relating the one-dimensional random field Ising model to a discrete stochastic mapping are generalized to a two-valued correlated random (Markovian) field and to the case of zero temperature. The fractal dimension of the support of the invariant measure is calculated in a simple approximation and its dependence on the physical parameters is discussed.Contribution to the symposium Statistical Mechanics of Phase Transitions—Mathematical and Physical Aspects, Trebo, CSSR, September 1–6, 1986. 相似文献
853.
F. Lunghini P. Azam M.H. Enrici E. Van Miert 《SAR and QSAR in environmental research》2020,31(9):655-675
ABSTRACT We report new consensus models estimating acute toxicity for algae, Daphnia and fish endpoints. We assembled a large collection of 3680 public unique compounds annotated by, at least, one experimental value for the given endpoint. Support Vector Machine models were internally and externally validated following the OECD principles. Reasonable predictive performances were achieved (RMSEext = 0.56–0.78) which are in line with those of state-of-the-art models. The known structural alerts are compared with analysis of the atomic contributions to these models obtained using the ISIDA/ColorAtom utility. A benchmarking against existing tools has been carried out on a set of compounds considered more representative and relevant for the chemical space of the current chemical industry. Our model scored one of the best accuracy and data coverage. Nevertheless, industrial data performances were noticeably lower than those on public data, indicating that existing models fail to meet the industrial needs. Thus, final models were updated with the inclusion of new industrial compounds, extending the applicability domain and relevance for application in an industrial context. Generated models and collected public data are made freely available. 相似文献
854.
毛细管电泳及其质谱联用技术分析重组人促红细胞生成素 总被引:3,自引:0,他引:3
用高效毛细管电泳测定了重组人促红细胞生成素(rhEPO)的微多相性、肽图,同时采用毛细管电泳质谱联用技术鉴定了部分非糖基化胰酶消解片段和O-126糖基化肽的结构。方法简便、快速,适用于rhEPO半成品的质量控制。 相似文献
855.
856.
We address the impact of nonlocality in the physical features exhibited by solitons supported by Kerr-type nonlinear media with an imprinted optical lattice. We discuss the solitons solution for a class of nonlinear Schr?dinger equations in the optical lattice with nonlocal nonlinearity. We also show via a uniform priori estimate that existence and uniqueness of the global solution for the initial problem. 相似文献
857.
Ahmed Taa 《Nonlinear Analysis: Theory, Methods & Applications》2011,74(18):7312-7324
The aim of this paper is to establish formulas for the subdifferentials of the sum and the composition of convex set-valued mappings under the Attouch–Brézis qualification condition. An application to a general set-valued optimization problem is considered. 相似文献
858.
859.
M. OKABE 《International Journal of Computational Fluid Dynamics》2013,27(1-2):179-191
The unified theory in infinite elementology is presented in one to three dimensions so that developed infinite elements are C° conformably connected with the isoparametric finite elements. It is further shown that the infinity mapping technology is easily incorporated into general finite element codes. 相似文献
860.