全文获取类型
收费全文 | 1745篇 |
免费 | 41篇 |
国内免费 | 7篇 |
专业分类
化学 | 910篇 |
晶体学 | 25篇 |
力学 | 71篇 |
数学 | 208篇 |
物理学 | 579篇 |
出版年
2023年 | 7篇 |
2022年 | 24篇 |
2021年 | 17篇 |
2020年 | 31篇 |
2019年 | 41篇 |
2018年 | 28篇 |
2017年 | 40篇 |
2016年 | 64篇 |
2015年 | 35篇 |
2014年 | 55篇 |
2013年 | 98篇 |
2012年 | 109篇 |
2011年 | 125篇 |
2010年 | 82篇 |
2009年 | 65篇 |
2008年 | 103篇 |
2007年 | 107篇 |
2006年 | 74篇 |
2005年 | 70篇 |
2004年 | 56篇 |
2003年 | 46篇 |
2002年 | 45篇 |
2001年 | 27篇 |
2000年 | 36篇 |
1999年 | 12篇 |
1998年 | 22篇 |
1997年 | 25篇 |
1996年 | 20篇 |
1995年 | 21篇 |
1994年 | 15篇 |
1993年 | 25篇 |
1992年 | 15篇 |
1991年 | 9篇 |
1990年 | 13篇 |
1989年 | 22篇 |
1988年 | 9篇 |
1987年 | 22篇 |
1986年 | 8篇 |
1985年 | 16篇 |
1984年 | 16篇 |
1983年 | 14篇 |
1982年 | 13篇 |
1981年 | 13篇 |
1980年 | 13篇 |
1979年 | 9篇 |
1978年 | 9篇 |
1977年 | 5篇 |
1975年 | 5篇 |
1974年 | 5篇 |
1954年 | 5篇 |
排序方式: 共有1793条查询结果,搜索用时 15 毫秒
1.
2.
Prashant M. Bhatt Gautam R. Desiraju 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(6):o362-o363
The title compound [systematic name: 8‐chloro‐11‐(piperidin‐4‐ylidene)‐6,11‐dihydro‐5H‐benzo[4,5]cyclohepta[2,1‐b]pyridine], C19H19ClN2, was crystallized from ethyl acetate. The interesting feature of the reported structure is that it does not contain any strong hydrogen bonds, although the molecule contains a secondary NH group, which is a good hydrogen‐bond donor. 相似文献
3.
4.
CV Tomy D Pal SS Banerjee S Ramakrishnan AK Grover S Bhattacharya MJ Higgins G Balakrishnan McK Paul 《Pramana》2002,58(5-6):925-935
The weakly pinned single crystals of the hexagonal 2H-NbSe2 compound have emerged as prototypes for determining and characterizing the phase boundaries of the possible order-disorder
transformations in the vortex matter. We present here a status report based on the ac and dc magnetization measurements of
the peak effect phenomenon in three crystals of 2H-NbSe2, in which the critical current densities vary over two orders of magnitude. We sketch the generic vortex phase diagram of
a weakly pinned superconductor, which also utilizes theoretical proposals. We also establish the connection between the metastability
effects and pinning. 相似文献
5.
Apurba Bhattacharya Nitin C. Patel Michael Peddicord Luca Parlanti John A. Grosso 《Tetrahedron letters》2006,47(30):5341-5343
An efficient, one-pot, phase transfer N-amination technology was developed. The protocol utilizes chloramine, an inexpensive and safe electrophilic aminating agent potentially viable for commercial manufacturing. 相似文献
6.
V Ravindran Pankaj Agrawal Rahul Basu Satyaki Bhattacharya J Blümlein V Del Duca R Harlander D Kosower Prakash Mathews Anurag Tripathi 《Pramana》2006,67(5):983-992
This is the report of the subgroup QCD of Working Group-4 at WHEPP-9. We present the activities that had taken place in the
subgroup and report some of the partial results arrived at following the discussion at the working group meetings. 相似文献
7.
It is shown how the traditional method of neglecting the energy of acoustic phonons and approximating their distribution by the equipartition law leads to significant errors in the phonon growth rate in a many-valley model semiconductor when the lattice temperature is low. 相似文献
8.
Apurba Bhattacharya Nitin C. Patel Ritesh Tichkule Jiejun Wu 《Tetrahedron letters》2006,47(4):565-567
A simple, surfactant-mediated, one-pot, solvent-free dealkylative cleavage of aryl ethers and esters followed by subsequent optional trans-alkylation under essentially neutral conditions has been developed. 相似文献
9.
This paper examines the steady state behaviour of a batch arrival queue with two phases of heterogeneous service along and Bernoulli schedule vacation under multiple vacation policy, where after two successive phases service or first vacation the server may go for further vacations until it finds a new batch of customer in the system. We carry out an extensive stationary analysis of the system, including existence of stationary regime, queue size distribution of idle period process, embedded Markov chain steady state distribution of stationary queue size, busy period distribution along with some system characteristics. 相似文献
10.
Raj Gandhi Kamales Kar S. Uma Sankar Abhijit Bandyopadhyay Rahul Basu Pijushpani Bhattacharjee Biswajoy Brahmachari Debrupa Chakraborti M. Chaudhury J. Chaudhury Sandhya Choubey E. J. Chun Atri Desmukhya Anindya Datta Gautam Dutta Sukanta Dutta Anjan Giri Sourendu Gupta Srubabati Goswami Namit Mahajan H. S. Mani A. Mukherjee Biswarup Mukhopadhyaya S. N. Nayak M. Randhawa Subhendu Rakshit Asim K. Ray Amitava Raychaudhuri D. P. Roy Probir Roy Suryadeep Roy Shiv Sethi G. Sigl Arunansu Sil N. Nimai Singh Mark Vagins Urjit Yagnik 《Pramana》2003,60(2):405-409
This is the report of neutrino and astroparticle physics working group at WHEPP-7. Discussions and work on CP violation in
long baseline neutrino experiments, ultra high energy neutrinos, supernova neutrinos and water Cerenkov detectors are discussed. 相似文献