全文获取类型
收费全文 | 1944篇 |
免费 | 64篇 |
国内免费 | 9篇 |
专业分类
化学 | 1291篇 |
晶体学 | 15篇 |
力学 | 63篇 |
数学 | 174篇 |
物理学 | 474篇 |
出版年
2023年 | 11篇 |
2022年 | 22篇 |
2021年 | 38篇 |
2020年 | 44篇 |
2019年 | 35篇 |
2018年 | 37篇 |
2017年 | 40篇 |
2016年 | 73篇 |
2015年 | 53篇 |
2014年 | 63篇 |
2013年 | 141篇 |
2012年 | 103篇 |
2011年 | 131篇 |
2010年 | 72篇 |
2009年 | 69篇 |
2008年 | 110篇 |
2007年 | 90篇 |
2006年 | 110篇 |
2005年 | 89篇 |
2004年 | 72篇 |
2003年 | 51篇 |
2002年 | 63篇 |
2001年 | 24篇 |
2000年 | 30篇 |
1999年 | 16篇 |
1998年 | 16篇 |
1997年 | 17篇 |
1996年 | 15篇 |
1995年 | 13篇 |
1994年 | 20篇 |
1993年 | 20篇 |
1992年 | 13篇 |
1991年 | 18篇 |
1990年 | 12篇 |
1989年 | 13篇 |
1988年 | 13篇 |
1987年 | 9篇 |
1986年 | 11篇 |
1985年 | 20篇 |
1984年 | 23篇 |
1983年 | 10篇 |
1982年 | 20篇 |
1981年 | 19篇 |
1980年 | 18篇 |
1979年 | 16篇 |
1978年 | 18篇 |
1977年 | 15篇 |
1976年 | 16篇 |
1973年 | 18篇 |
1965年 | 8篇 |
排序方式: 共有2017条查询结果,搜索用时 15 毫秒
1.
de Santana Felipe Silva Gracioso Louise Hase Karolski Bruno dos Passos Galluzzi Baltazar Marcela Mendes Maria Anita do Nascimento Claudio Augusto Oller Perpetuo Elen Aquino 《Applied biochemistry and biotechnology》2019,189(1):103-115
Applied Biochemistry and Biotechnology - The human exposure to bisphenol A (BPA) occurs frequently. Once, this compound was one of the highest volume chemicals produced worldwide and used as a... 相似文献
2.
A synthesis of methyl 2-oxo-5-vinyl-tetrahydrofuran-3-carboxylate involving five synthetic steps from commercially available 3,4-dihydroxybutene is reported. 相似文献
3.
The spin-1 Ising model, which is equivalent to the three-component lattice gas model, is used to study wetting transitions in three-component surfactant systems consisting of an oil, water, and a nonionic surfactant. Phase equilibria, interfacial profiles, and interfacial tensions for three-phase equilibrium are determined in mean field approximation, for a wide range of temperature and interaction parameters. Surfactant interaction parameters are found to strongly influence interfacial tensions, reducing them in some cases to ultralow values. Interfacial tensions are used to determine whether the middle phase, rich in surfactant, wets or does not wet the interface between the oil-rich and water-rich phases. By varying temperature and interaction parameters, a wetting transition is located and found to be of the first order. Comparison is made with recent experimental results on wetting transitions in ternary surfactant systems.This paper is dedicated to J. K. Percus in honor of his 65th birthday. 相似文献
4.
Simon G. Bott Alan P. Marchand Dongxia Xing Rajesh Shukla Stephen James Obrey K. Venkatesan J. Narasimha Moorthy 《Journal of chemical crystallography》1997,27(11):661-665
NaBH4 reduction of a cage dione proceeds in a stereospecific fashion to give theendo,endo-diol. This reactivity is related to the crystal structure. 相似文献
5.
Europium (Eu+) ions were confined in a Paul trap and detected by non-destructive method. Storage time of Eu+ ions achieved in vacuum was improved by orders of magnitude employing buffer gas cooling. The experimentally detected signal
was fitted to the ion response signal and the total number of ions trapped was estimated. It is found that the peak signal
amplitude as well as the product of FWHM and the peak signal amplitude is proportional to the total number of trapped ions.
The trapped ion secular frequency was swept at different rates and its effect on the absorption line profile was studied both
experimentally and theoretically. 相似文献
6.
7.
8.
9.
10.
Anita M. R. Fisher Kathleen Danenberg Debabrata Banerjee Joseph R. Bertino Peter Danenberg Charles J. Gomer 《Photochemistry and photobiology》1997,66(2):265-270
Loss of p53 function has been correlated with decreased sensitivity to chemotherapy and radiation therapy in a variety of human tumors. Comparable analysis of p53 status with sensitivity to oxidative stress induced by pho-todynamic therapy has not been reported. In the current study we examined photosensitivity in human promye-locytic leukemia HL60 cells exhibiting either wild-type p53, mutated p53 or deleted p53 expression. Experiments were performed using a purpurin, tin ethyl etiopurpurin (SnET2)-, or a porphyrin, Photofrin (PH)-based photo-sensitizer. Total SnET2 accumulation was comparable in all three cell lines. Uptake of PH was highest in cells expressing wild-type p53 but incubation conditions could be adjusted to achieve equivalent cellular PH levels during experiments that analyzed photosensitivity. Survival measurements demonstrated that HL60 cells expressing wild-type p53 were more sensitive to PH- and SnET2-mediated photosensitization, as well as to UVC irradiation, when compared to HL60 cells exhibiting deleted or mutated p53 phenotypes. A rapid apoptotic response was observed following purpurin- and porphyrin-induced photosensitization in all cell lines. Results of this study indicate that photosensitivity is increased in HL60 cells expressing wild-type p53 and that photosensitizer-medi-ated oxidative stress can induce apoptosis through a p53-independent mechanism in HL60 cells . 相似文献