全文获取类型
收费全文 | 1073篇 |
免费 | 37篇 |
国内免费 | 3篇 |
专业分类
化学 | 555篇 |
晶体学 | 11篇 |
力学 | 37篇 |
数学 | 71篇 |
物理学 | 439篇 |
出版年
2023年 | 11篇 |
2022年 | 12篇 |
2021年 | 12篇 |
2020年 | 25篇 |
2019年 | 32篇 |
2018年 | 33篇 |
2017年 | 18篇 |
2016年 | 34篇 |
2015年 | 26篇 |
2014年 | 38篇 |
2013年 | 113篇 |
2012年 | 75篇 |
2011年 | 77篇 |
2010年 | 48篇 |
2009年 | 49篇 |
2008年 | 54篇 |
2007年 | 58篇 |
2006年 | 38篇 |
2005年 | 39篇 |
2004年 | 18篇 |
2003年 | 17篇 |
2002年 | 26篇 |
2001年 | 12篇 |
2000年 | 11篇 |
1999年 | 9篇 |
1998年 | 12篇 |
1997年 | 9篇 |
1996年 | 18篇 |
1995年 | 18篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 14篇 |
1991年 | 5篇 |
1990年 | 9篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 12篇 |
1983年 | 15篇 |
1982年 | 11篇 |
1981年 | 9篇 |
1980年 | 12篇 |
1979年 | 7篇 |
1978年 | 10篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1938年 | 2篇 |
排序方式: 共有1113条查询结果,搜索用时 187 毫秒
1.
Das Pritam Kumar Mallik Arnab Kumar Molla Altaf Hossain Santra Apurba Kumar Ganguly Ranjan Saha Abhijit Kumar Sugam Aswal V. K. 《Journal of Thermal Analysis and Calorimetry》2022,147(10):5617-5635
Journal of Thermal Analysis and Calorimetry - Nanofluids have gained recent attention because of their potential applications in diverse engineering fields like enhancing thermal transport,... 相似文献
2.
Correlation between the particles from the proton-nucleus interactions in emulsion at 70 GeV/c is presented through the study of the rapidity gap analysis and compared with the two-particle rapidity correlations. It is observed that the strength of correlation decreases as the size of cluster increases. Asymmetry between the forward and backward components were also studied.Authors are thankful to Prof. K. D. Tolstov, JINR, Dubna, USSR for sending the exposed emulsion plates. Thanks are also due to UGC for financial assistance. We sincerely acknowledge the encouragement from Prof. T. Roy. 相似文献
3.
Chemical techniques were employed to synthesize CdS nanoparticles embedded in polymer (PEG 300) and sol-gel silica matrices. Systematic growth of particles (radius 3–9 nm) was obtained by adjusting post-deposition annealing temperature and time to examine the dependence of surface-state–related luminescence on particle size. Photoluminescence (PL) peak energy showed a linear dependence with a gentle slope in the weak confinement region and a steep slope in the strong confinement region, the divergence being observed near the excitonic Bohr radius for CdS. The empirical relation proposed for the weak confinement region could be used for estimating chemically prepared CdS nanoparticle size with a high degree of reliability from PL peak energy. 相似文献
4.
Xiao Huang Bishwa Ranjan Nayak Tao Lu Lowe 《Journal of polymer science. Part A, Polymer chemistry》2004,42(20):5054-5066
A series of novel multifunctional hydrogels that combined the merits of both thermoresponsive and biodegradable polymeric materials were designed, synthesized, and characterized. The hydrogels were copolymeric networks composed of N‐isopropylacrylamide (NIPAAM) as a thermoresponsive component, poly(L‐lactic acid) (PLLA) as a hydrolytically degradable and hydrophobic component, and dextran as an enzymatically degradable and hydrophilic component. The chemical structures of the hydrogels were characterized by an attenuated total reflection–Fourier transform infrared spectroscopy (ATR–FTIR) technique. The hydrogels were thermoresponsive, showing a lower critical solution temperature (LCST) at approximately 32 °C, and their swelling properties strongly depended on temperature changes, the balance of the hydrophilic/hydrophobic components, and the degradation of the PLLA component. The degradation of the hydrogels caused by hydrolytic cleavage of ester bonds in the PLLA component was faster at 25 °C below the LCST than at 37 °C above the LCST, determined by the ATR–FTIR technique. Due to their multifunctional properties, the designed hydrogels show great potential for biomedical applications, including drug delivery and tissue engineering. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5054–5066, 2004 相似文献
5.
Gamma ray bursts (GRBs) have been proposed as one possible class of sources of the ultrahigh energy cosmic ray (UHECR) events
observed up to energies ≳ 1020 eV. The synchrotron radiation of the highest energy protons accelerated within the GRB source should produce gamma rays up
to TeV energies. Here we briefly discuss the implications on the energetics of the GRB from the point of view of the detectability
of the prompt TeV γ-rays of proton-synchrotron origin in GRBs in the up-coming ICECUBE muon detector in the south pole. 相似文献
6.
W. Riess J. P. Cherasskowa L. A. Weißbrut W. Ruziczka F. J. Squire M. N. Ghose und S. N. Bhattacharjee 《Fresenius' Journal of Analytical Chemistry》1938,114(5-6):233-235
Ohne Zusammenfassung 相似文献
7.
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
8.
A layer of stratified combination composed of selected radiation shielding materials acquires better shielding property. Albedo
is used in such measurements as an integral measure ofγ-ray scattering. The stratified slabs of alternating heterogeneous layers have been found to have a virtual homogeneous property
with a definite effective atomic number. The angular distribution of back-scattered photons as well as the total number albedo
values for iron, aluminium and concrete in stratified combination for 662 keV and 1250 keV photons are reported. 相似文献
9.
10.
Some bounds on the entries and on the norm of the inverse of triangular matrices with nonnegative and monotone entries are found. All the results are obtained by exploiting the properties of the fundamental matrix of the recurrence relation which generates the sequence of the entries of the inverse matrix. One of the results generalizes a theorem contained in a recent article of one of the authors about Toeplitz matrices. 相似文献