全文获取类型
收费全文 | 273篇 |
免费 | 18篇 |
国内免费 | 1篇 |
专业分类
化学 | 180篇 |
晶体学 | 3篇 |
力学 | 13篇 |
数学 | 39篇 |
物理学 | 57篇 |
出版年
2021年 | 1篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 9篇 |
2015年 | 11篇 |
2014年 | 9篇 |
2013年 | 19篇 |
2012年 | 12篇 |
2011年 | 21篇 |
2010年 | 8篇 |
2009年 | 6篇 |
2008年 | 13篇 |
2007年 | 12篇 |
2006年 | 12篇 |
2005年 | 17篇 |
2004年 | 11篇 |
2003年 | 9篇 |
2002年 | 13篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1967年 | 1篇 |
排序方式: 共有292条查询结果,搜索用时 31 毫秒
61.
A.R. Peaker V.P. Markevich I.D. Hawkins B. Hamilton K. Bonde Nielsen K. Gościński 《Physica B: Condensed Matter》2012,407(15):3026-3030
This paper is to commemorate the work of Leszek Dobaczewski1 who devoted much of his life to the development and application of high resolution DLTS. 相似文献
62.
Effects of 5-aminolaevulinic acid on human ovarian cancer cells and human vascular endothelial cells in vitro. 总被引:3,自引:0,他引:3
S Sp?rri V Chopra N Egger H K Hawkins M Motamedi E Dreher H Schneider 《Journal of photochemistry and photobiology. B, Biology》2001,64(1):8-20
Results are reported on the cellular effects and the sensitivity of cultured tumor epithelial cells (TEC) derived from human ovarian cystadenocarcinoma and human umbilical vein-derived endothelial cells (HUVEC) to exogenous 5-aminolaevulinic acid (ALA) and ALA-induced photodynamic therapy (PDT). Cellular alterations and PDT efficiency were evaluated using colorimetric thiazolyl blue (MTT) assay, trypan blue exclusion assay, electron microscopy, and gel electrophoresis. ALA-induced protoporphyrin IX (PpIX) accumulation in TEC was associated with a concentration and time-dependent significant decrease in mitochondrial activity, increase in cell membrane permeability, and dark toxicity. Maximum PpIX loaded TEC demonstrated a high sensitivity to PDT. Neither cellular alterations nor PDT effects were observed in HUVEC under identical experimental conditions. These results indicate a potential clinical value for the use of ALA-mediated PDT to treat minimal residual disease in mucinous ovarian carcinoma. In addition, the ALA-induced PpIX cytotoxicity may be exported to a new chemotherapeutic regimen via a conventionally viewed photochemotherapeutic agent. 相似文献
63.
D. Robert Daniels Thomas C. B. McLeish Rama Kant Bryan J. Crosby Ronald N. Young Andrew Pryke Jürgen Allgaier D. J. Groves R. J. Hawkins 《Rheologica Acta》2001,40(5):403-415
We present experiments and theory on the diluted melt dynamics of monodisperse entangled polymers of linear, star and H-shaped
architecture. Frequency-dependent rheological data on a series of progressively diluted linear, star and H-polymers are in
good agreement with a refined tube-model theory that, for H-polymers, combines star polymer melt behaviour at high frequency,
with linear polymer reptation behaviour at low frequencies. Taking into account the effect of dilution via some simple scaling
relations, mild polydispersity and by incorporating the high frequency Rouse modes, we are able to model quantitatively the
entire frequency range. This work suggests a novel rheological route to analysing long chain branching in polymer melts.
Received: 6 April 2000/Accepted: 21 December 2000 相似文献
64.
65.
D.S. Broomhead J.N. Elgin E. Jakeman Sarben Sarkar S.C. Hawkins P. Drazin 《Optics Communications》1984,50(1):56-62
The statistical properties of the electric field solution of the Maxwell-Bloch equations describing a single mode, homogeneously broadened laser in the mean field limit are investigated in the strange attractor regime. The electric field distribution sis calculated and it is found that the low order intensity moments are somewhat higher than those for thermal-chaotic light whilst the higher order moments are substantially lower. The field and intensity correlation functions are also calculated and found to exhibit radically different behaviour. The results are interpreted in terms of iterative map which is dederived using multiple time-scale perturbation theory. It is shown that a simple random phasor model is compatible with the numerical data. 相似文献
66.
Roger Bishop Ian G. Dance Stephen C. Hawkins Tony Lipari 《Journal of inclusion phenomena and macrocyclic chemistry》1984,2(1-2):75-83
The discovery thatexo-2,exo-6-dihydroxy-2,6-dimethylbicyclo [3.3.1]nonane (2) forms novel multimolecular canal-type inclusion complexes has led to a systematic study of related molecular structures. This synthetic programme has shown that diol (2) is the prototype of a family of host diols all with the same crystallographic space groupP3121, but with distinctly different canal shapes and dimensions. The structures of the first four members of this new family of hosts are described and contrasted. 相似文献
67.
Greg Kaplan Greg Drake Kerri Tollison Leslie Hall Tommy Hawkins 《Journal of heterocyclic chemistry》2005,42(1):19-27
Quarternary salts based upon 3‐alkyl substituted 1‐amino‐1,2,3‐triazolium cations (alkyl = methyl, ethyl, nypropyl, 2‐propenyl, and n‐butyl) have been synthesized and characterized by vibrational spectra, multinuclear NMR, elemental analysis, and DSC studies. Subsequent diazotization of these salts results in the exclusive formation of 1‐alkyl‐1,2,3‐triazoles. Single crystal X‐ray studies were carried out for 1‐amino‐3‐methyl‐1,2,3‐triazolium iodide, 1‐amino‐3‐ethyl‐1,2,3‐triazolium bromide, 1‐amino‐3‐n‐propyl‐1,2,3‐triazolium bromide, and 1‐amino‐3‐n‐butyl‐1,2,3‐triazolium bromide as well as the starting heterocycle, 1‐amino‐1,2,3‐triazole, and all of the structures are discussed. 相似文献
68.
The development of the DIGE system: 2D fluorescence difference gel analysis technology 总被引:15,自引:0,他引:15
Two-dimensional (2D) gel electrophoresis is a powerful technique enabling simultaneous visualization of relatively large portions of the proteome. However, the well documented issues of variation and lack of sensitivity and quantitative capabilities of existing labeling reagents, has limited the use of this technique as a quantitative tool. Two-dimensional difference gel electrophoresis (2D DIGE) builds on this technique by adding a highly accurate quantitative dimension. 2D DIGE enables multiple protein extracts to be separated on the same 2D gel. This is made possible by labeling of each extract using spectrally resolvable, size and charge-matched fluorescent dyes known as CyDye DIGE fluors. 2D DIGE involves use of a reference sample, known as an internal standard, which comprises equal amounts of all biological samples in the experiment. Including the internal standard on each gel in the experiment with the individual biological samples means that the abundance of each protein spot on a gel can be measured relative (i.e. as a ratio) to its corresponding spot in the internal standard present on the same gel. Ettan DIGE is the system of technologies that has been optimized to fully benefit from the advantages provided by 2D DIGE.Cy, CyDye, DeCyder, Ettan, ImageMaster and Typhoon are trademarks of Amersham Biosciences Limited. Amersham and Amersham Biosciences are trademarks of Amersham plc. 相似文献
69.
70.
Cory A. Hawkins Ilya A. Shkrob Carol J. Mertz Mark L. Dietz Michael D. Kaminski 《Analytica chimica acta》2012
A method has been developed for the isolation of strontium from human urine for subsequent determination in sample volumes as low as 5–20 mL. This method involves the acidification of the sample using methanesulfonic acid and its decolorization using charcoal, treatment of the filtrate with Diphonix® resin, and subsequent concentration of strontium on Sr resin. Data from retention model simulations provided the initial conditions which were then optimized by actual column separations. Diphonix® resin was shown to be effective at removing alkali metal ions from the urine matrix under conditions that retain higher valence ions. The suggested processing method provides 99% recovery of Sr2+, a concentration factor of 50, and an expected per sample processing time of less than 1 h. 相似文献