全文获取类型
收费全文 | 966篇 |
免费 | 52篇 |
国内免费 | 7篇 |
专业分类
化学 | 564篇 |
晶体学 | 5篇 |
力学 | 36篇 |
数学 | 259篇 |
物理学 | 161篇 |
出版年
2023年 | 12篇 |
2022年 | 14篇 |
2021年 | 30篇 |
2020年 | 27篇 |
2019年 | 23篇 |
2018年 | 15篇 |
2017年 | 13篇 |
2016年 | 53篇 |
2015年 | 42篇 |
2014年 | 48篇 |
2013年 | 79篇 |
2012年 | 86篇 |
2011年 | 59篇 |
2010年 | 35篇 |
2009年 | 31篇 |
2008年 | 52篇 |
2007年 | 44篇 |
2006年 | 42篇 |
2005年 | 22篇 |
2004年 | 34篇 |
2003年 | 37篇 |
2002年 | 22篇 |
2001年 | 14篇 |
2000年 | 13篇 |
1999年 | 13篇 |
1998年 | 13篇 |
1997年 | 8篇 |
1996年 | 4篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 8篇 |
1984年 | 12篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1981年 | 7篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 8篇 |
1976年 | 5篇 |
1974年 | 5篇 |
1897年 | 2篇 |
1893年 | 2篇 |
排序方式: 共有1025条查询结果,搜索用时 15 毫秒
141.
142.
Frau Dr. L. S. Kudrjawzewa H. H. Kirss O. G. Eisen 《Monatshefte für Chemie / Chemical Monthly》1974,105(1):19-29
A simple method for calculating the vapor composition in ternary liquid systems is described and experimentally verified. Starting from the differential equation derived for curves of constant relative fugacity of two components (ik=const) a relation is derived for the estimation of these curves in the concentration triangle. The ik-values are determined as the finite points of curves ik=const from the data of the vapor-liquid composition of the binary systems.
Mit 3 Abbildungen 相似文献
Mit 3 Abbildungen 相似文献
143.
Ludmila S. Kudrjawzewa O. Eisen M. P. Sussarjew 《Monatshefte für Chemie / Chemical Monthly》1976,107(1):125-132
A simple method for predicting ternary vapor—liquid equilibria is presented and experimentally verified. The method is based on the solution of algebraic equations derived by the integration of the differential equations characterizing the dependence of the equilibrium properties of the ternary system on the state variables with the assumption that the partial derivates enter as constants. The values of the partial derivates are approximately evaluated from the binary experimental data. 相似文献
144.
145.
A method is presented to construct interpolation functions intothe 2 x 2 open spectral unit ball. For the spectral NevanlinnaPickproblem, these functions are in some sense extremal, and theset of all these interpolation functions is enough to solveany interpolation problem, with solvable finite interpolationdata. This fact is used to compute the complex geodesics forthe symmetrized bidisc and for the spectral unit ball, and tosolve completely the two-point interpolation problem for thetwo target sets. 相似文献
146.
We investigate the pressure within an irrotational fluid in a periodic, steady, two‐dimensional gravity wave above a flat bed. We prove that the pressure in the fluid strictly decreases horizontally away from the crest line. Furthermore, the pressure strictly increases with depth. We also investigate the effect of an underlying current on the paths of the particles. © 2009 Wiley Periodicals, Inc. 相似文献
147.
Adler SS Afanasiev S Aidala C Ajitanand NN Akiba Y Al-Jamel A Alexander J Aoki K Aphecetche L Armendariz R Aronson SH Averbeck R Awes TC Babintsev V Baldisseri A Barish KN Barnes PD Bassalleck B Bathe S Batsouli S Baublis V Bauer F Bazilevsky A Belikov S Bjorndal MT Boissevain JG Borel H Brooks ML Brown DS Bruner N Bucher D Buesching H Bumazhnov V Bunce G Burward-Hoy JM Butsyk S Camard X Chand P Chang WC Chernichenko S Chi CY Chiba J Chiu M Choi IJ Choudhury RK Chujo T Cianciolo V Cobigo Y 《Physical review letters》2006,96(22):222301
Deuteron-gold (d+Au) collisions at the Relativistic Heavy Ion Collider provide ideal platforms for testing QCD theories in dense nuclear matter at high energy. In particular, models suggesting strong saturation effects for partons carrying small nucleon momentum fraction (x) predict modifications to jet production at forward rapidity (deuteron-going direction) in d+Au collisions. We report on two-particle azimuthal angle correlations between charged hadrons at forward/backward (deuteron/gold going direction) rapidity and charged hadrons at midrapidity in d+Au and p+p collisions at square root of sNN=200 GeV. Jet structures observed in the correlations are quantified in terms of the conditional yield and angular width of away-side partners. The kinematic region studied here samples partons in the gold nucleus with x~0.1 to ~0.01. Within this range, we find no x dependence of the jet structure in d+Au collisions. 相似文献
148.
Stefania‐Felicia Barbuceanu Gabriela Bancescu Gabriel Saramet Florica Barbuceanu Constantin Draghici Flavian Stefan Radulescu Aura Ionescu Simona Negres 《Heteroatom Chemistry》2013,24(4):309-321
In the present study, new 1,2,4‐triazoles, 1,3,4‐thiadiazoles, and acylthiosemicarbaz‐ides derived from 4‐(4‐chlorophenylsulfonyl)benzoic acid hydrazide were synthesized and screened for their antimicrobial and analgesic activities. Acylthiosemicarbazides 2–4 were synthesized by a reaction of 4‐(4‐chlorophenyl‐sulfonyl)benzoic acid hydrazide 1 with different arylisothiocyanates.4,5‐Disubstituted‐2,4‐dihydro‐3H‐1,2,4‐triazol‐3‐thiones 5–7 and 2,5‐disubstituted‐1,3,4‐thiadiazoles 8–10 were obtained by dehydrative cyclization of corresponding acylthiosemicarbazide derivatives 2–4 in basic media (8% aqueous sodium hydroxide) and in acidic media (sulfuric acid or phosphorous oxychloride), respectively. The structures of the newly synthesized compounds have been confirmed on the basis of elemental analysis and spectral studies (IR, 1H NMR, 13C NMR, MS). Their antimicrobial activities against some bacteria and yeasts were investigated. The analgesic activity of all compounds was performed with two pharmacological tests: the writhing test induced with acetic acid and hot‐plate test. The results showed that triazole 7 had the best antimicrobial activity against Bacillus cereus. In the chemical stimulus test, triazoles 6 and 7 were the most active compounds whereas in the hot‐plate test thiadiazoles 9 and 10 exhibited the highest analgesic activity. 相似文献
149.
Abstract We study multiple Riemann-Stieltjes integral approximations to multiple Stratonovich fractional integrals. Two standard approximations (Wong-Zakai and Mollifier approximations) are considered and we show the convergence in the mean square sense and uniformly on compact time intervals of these approximations to the multiple Stratonovich fractional integral. 相似文献
150.
Abstract Double Stratonovich integrals with respect to the odd part and even part of the fractional Brownian motion are constructed. The first and the second moments of such integrals are explicitly identified. As application of double Stratonovich integrals a strong law of large numbers for efBm and ofBm is derived. Riemann–Stieltjes integral approximations to double Stratonovich fractional integrals are also considered. The strong convergence (almost surely and mean square) is obtained for approximations based on explicit series expansions of the fractional Brownian processes. The weak convergence is derived for approximations by processes with absolutely continuous paths which converge weakly to the considered fractional Brownian processes. The above-mentioned convergences are obtained for deterministic integrands which are given by bimeasures. 相似文献