全文获取类型
收费全文 | 675篇 |
免费 | 20篇 |
国内免费 | 1篇 |
专业分类
化学 | 404篇 |
晶体学 | 28篇 |
力学 | 4篇 |
数学 | 65篇 |
物理学 | 195篇 |
出版年
2023年 | 6篇 |
2022年 | 14篇 |
2021年 | 14篇 |
2020年 | 18篇 |
2019年 | 10篇 |
2018年 | 10篇 |
2017年 | 11篇 |
2016年 | 25篇 |
2015年 | 14篇 |
2014年 | 45篇 |
2013年 | 49篇 |
2012年 | 46篇 |
2011年 | 40篇 |
2010年 | 28篇 |
2009年 | 31篇 |
2008年 | 34篇 |
2007年 | 19篇 |
2006年 | 29篇 |
2005年 | 27篇 |
2004年 | 24篇 |
2003年 | 20篇 |
2002年 | 13篇 |
2001年 | 14篇 |
2000年 | 12篇 |
1999年 | 10篇 |
1998年 | 7篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 21篇 |
1994年 | 10篇 |
1993年 | 9篇 |
1992年 | 7篇 |
1990年 | 2篇 |
1989年 | 7篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 9篇 |
1984年 | 5篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 7篇 |
1976年 | 3篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 5篇 |
1936年 | 4篇 |
排序方式: 共有696条查询结果,搜索用时 15 毫秒
161.
C. Agarwal A. Goswami P. C. Kalsi S. Singh A. Mhatre A. Ramaswami 《Journal of Radioanalytical and Nuclear Chemistry》2008,275(2):445-451
Cumulative yields of 27 fission products have been determined in 229Th(n,f) by recoil catcher technique followed by gamma-ray spectrometry. Absolute fission yields were arrived at from the fission
rate measured by track etch counting method. Mass yields were obtained from the cumulative yields using the charge distribution
parameters reported in the literature. The values agree well with the reported values obtained both by physical and radiochemical
methods. The resulting asymmetric mass distribution shows strong fluctuation in the yields in the light and heavy wings with
a periodicity of five mass units. 相似文献
162.
S. Bhattacharyya S. K. Saha M. Chakravorty B. M. Mandal D. Chakravorty K. Goswami 《Journal of Polymer Science.Polymer Physics》2001,39(16):1935-1941
The frequency‐dependent conductivity of interpenetrating polymer network composites of polypyrrole (PPy) and poly(vinyl acetate) (PVAc) synthesized by FeCl3‐impregnated PVAc films being dipped into solutions of pyrrole in water was investigated over a frequency range of 100 Hz to 2 MHz and a temperature range of 110–300 K. For specimens with a PPy content less than the percolation threshold, the quantum mechanical tunneling of electrons was the conduction mechanism. For specimens with a higher PPy content, correlated barrier hopping of electrons appeared to be operative. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1935–1941, 2001 相似文献
163.
Mondal Animesh Naskar Barnali Goswami Sanchita Prodhan Chandraday Chaudhuri Keya Mukhopadhyay Chhanda 《Molecular diversity》2020,24(1):93-106
Molecular Diversity - A quick access tool for the one-pot, chromatography-free synthesis of the diversified dihydrospiro[indeno[1,2-b]pyridine-4,3′-indoline or... 相似文献
164.
165.
Francesco Ricci Jeremy C. Palmer Yagyik Goswami Srikanth Sastry C. Austen Angell 《Molecular physics》2019,117(22):3254-3268
The existence of metastable liquid-liquid phase transitions (LLPTs) in tetrahedral liquids such as water, silicon, and silica has been the subject of vigorous scientific debate. Because high crystallization rates hinder experimental investigation at deeply supercooled conditions, computer simulation has been widely employed to investigate the existence of LLPTs in molecular models of tetrahedral liquids. The Stillinger-Weber (SW) model of silicon (and more generally, the SW family of models) has been actively studied along these lines. Whereas some studies observe evidence of an LLPT in this model, others report that only a single metastable liquid exists under deeply supercooled conditions. Here, we perform extensive state-of-the-art free energy calculations to investigate the possibility of an LLPT in the SW model of silicon. A similar analysis is also presented for the generalized SW family of models constructed by varying the strength of the three-body energetic term. Our analysis does not show any evidence of an LLPT in SW silicon nor in the generalized family of SW models over the parameter ranges studied. Explanations for the aforementioned discrepancies between previous studies are provided, along with explicit demonstrations of how these discrepancies may have occurred. Outstanding ambiguities and directions for future work are also discussed. 相似文献
166.
Extending an idea of Spitzer [2], a way to compute the moments of the time of escape from (−N,L) by a symmetric simple random walk is exhibited. It is shown that all these moments depend polynomially onL andN.
The research of this author was supported by the National Board of Higher Mathematics, Bombay, India 相似文献
167.
Bedartha Goswami Norbert Marwan Georg Feulner Jürgen Kurths 《The European physical journal. Special topics》2013,222(3-4):861-873
We investigate a network of influences connected to global mean temperature. Considering various climatic factors known to influence global mean temperature, we evaluate not only the impacts of these factors on temperature but also the directed dependencies among the factors themselves. Based on an existing recurrence-based connectivity measure, we propose a new and more general measure that quantifies the level of dependence between two time series based on joint recurrences at a chosen time delay. The measures estimated in the analysis are tested for statistical significance using twin surrogates. We find, in accordance with earlier studies, the major drivers for global mean temperature to be greenhouse gases, ENSO, volcanic activity, and solar irradiance. We further uncover a feedback between temperature and ENSO. Our results demonstrate the need to involve multiple, delayed interactions within the drivers of temperature in order to develop a more thorough picture of global temperature variations. 相似文献
168.
This paper shows the formation of nonlinear coherent structures in a dusty plasma in presence of dust charge fluctuations.
Using the typical plasma parameters the potential of the nonlinear coherent structures is derived. 相似文献
169.
A self-consistent kinetic treatment is presented here, where the Boltzmann equation is solved for a particle conserving Krook
collision operator. The resulting equations have been implemented numerically. The treatment solves for the entire quasineutral
column, making no assumptions about λmfp/L, where λmfp is the ion-neutral collision mean free path and L the size of the device. Coulomb collisions are neglected in favour of collisions with neutrals, and the particle source is
modeled as a uniform Maxwellian. Electrons are treated as an inertialess but collisional fluid. The ion distribution function
for the trapped and the transiting orbits is obtained. Interesting findings include the anomalous heating of ions as they
approach the presheath, the development of strongly non-maxwellian features near the last λmfp, and strong modifications of the sheath criterion. 相似文献
170.
A Triphenyl Amine‐Based Solvatofluorochromic Dye for the Selective and Ratiometric Sensing of OCl− in Human Blood Cells 下载免费PDF全文
Prof. Shyamaprosad Goswami Krishnendu Aich Sangita Das Bholanath Pakhira Kakali Ghoshal Dr. Ching Kheng Quah Dr. Maitree Bhattacharyya Prof. Hoong‐Kun Fun Prof. Sabyasachi Sarkar 《化学:亚洲杂志》2015,10(3):694-700
A new visible‐light‐excitable fluorescence ratiometric probe for OCl? has been developed based on a triphenylamine‐diamiomaleonitrile (TAM) moiety. The structure of the dye was confirmed by single‐crystal X‐ray analysis. It behaves as a highly selective and sensitive probe for OCl? over other analytes with a fast response time (~100 s). OCl? reacts with the probe leading to the formation of the corresponding aldehyde in a mixed‐aqueous system. The detection limit of the probe is in the 10?8 M range. The probe (TAM) also exhibits solvatofluorochromism. Changing the solvent from non‐polar to polar, the emission band of TAM largely red‐shifted. Moreover, the probe shows an excellent performance in real‐life application in detecting OCl? in human blood cells. The experimentally observed changes in the structure and electronic properties of the probe after reaction with OCl? were studied by DFT and TDDFT computational calculations. 相似文献