全文获取类型
收费全文 | 4390篇 |
免费 | 142篇 |
国内免费 | 29篇 |
专业分类
化学 | 3135篇 |
晶体学 | 14篇 |
力学 | 126篇 |
数学 | 617篇 |
物理学 | 669篇 |
出版年
2024年 | 6篇 |
2023年 | 36篇 |
2022年 | 109篇 |
2021年 | 106篇 |
2020年 | 98篇 |
2019年 | 102篇 |
2018年 | 68篇 |
2017年 | 54篇 |
2016年 | 159篇 |
2015年 | 118篇 |
2014年 | 154篇 |
2013年 | 260篇 |
2012年 | 314篇 |
2011年 | 349篇 |
2010年 | 211篇 |
2009年 | 202篇 |
2008年 | 313篇 |
2007年 | 291篇 |
2006年 | 216篇 |
2005年 | 249篇 |
2004年 | 212篇 |
2003年 | 153篇 |
2002年 | 157篇 |
2001年 | 54篇 |
2000年 | 47篇 |
1999年 | 34篇 |
1998年 | 33篇 |
1997年 | 33篇 |
1996年 | 41篇 |
1995年 | 32篇 |
1994年 | 33篇 |
1993年 | 24篇 |
1992年 | 24篇 |
1991年 | 25篇 |
1990年 | 32篇 |
1989年 | 20篇 |
1988年 | 26篇 |
1987年 | 16篇 |
1986年 | 13篇 |
1985年 | 20篇 |
1984年 | 12篇 |
1982年 | 16篇 |
1981年 | 12篇 |
1980年 | 11篇 |
1979年 | 10篇 |
1978年 | 8篇 |
1977年 | 8篇 |
1976年 | 5篇 |
1975年 | 6篇 |
1973年 | 6篇 |
排序方式: 共有4561条查询结果,搜索用时 15 毫秒
111.
Momotenko D Cortés-Salazar F Josserand J Liu S Shao Y Girault HH 《Physical chemistry chemical physics : PCCP》2011,13(12):5430-5440
Ionic transport in charged conical nanopores is known to give rise to ion current rectification. The present study shows that the rectification direction can be inverted when using electrolyte solutions at very low ionic strengths. To elucidate these phenomena, electroneutral conical nanopores containing a perm-selective region at the tip have been investigated and shown to behave like classical charged nanopores. An analytical model is proposed to account for these rectification processes. 相似文献
112.
113.
Ibon Alkorta Fernando Blanco Pere M. Deyà José Elguero Carolina Estarellas Antonio Frontera David Quiñonero 《Theoretical chemistry accounts》2010,126(1-2):1-14
This review covers two aspects concerning cooperativity in multiple weak bonds: a summary of literature results and a theoretical study of a complete series of model complexes. All the 15 combination of five weak bonds were explored: hydrogen bonds, hydric bonds, dihydrogen bonds, halogen bonds and ion–π interactions. Since in several cases there were no examples reported, a systematic exploration has been carried out on simple models at the MP2/aug-cc-pVTZ level. The results thus obtained have been analyzed using the atoms in molecules methodology. 相似文献
114.
With reference to the recently published article (Abdujabbarov et al. in Gen Relativ Gravit 40:2515–2532, 2008), we question the correctness of the method employed and the physical consistency of the claimed results. 相似文献
115.
The well-known Hellmann-Feynman theorem of quantum mechanics connected with the derivative of the eigenvalues with respect to a parameter upon which the Hamiltonian depends, is generalized to include cases in which the domain of definition of the Hamiltonian of the system also depends on that parameter. 相似文献
116.
117.
Vivian?Regina?Trist?o Fernando?Felippe?de?Carvalho Cinthia?Zanini?Gomes Adriana?Regina?Miranda Cíntia?C.?Vequi-Suplicy Maria?Teresa?Lamy Nestor?Schor Maria?Helena?Bellini 《Journal of fluorescence》2010,20(3):665-669
The progression to end-stage renal failure is independent of the initial pathogenic mechanism. Metabolic acidosis is a common consequence of chronic renal failure that results from inadequate ammonium excretion and decreased tubular bicarbonate reabsorption. Protoporphyrin IX (PpIX) is the immediate metabolic precursor of the heme molecule. The purpose of this study was to evaluate the levels of erythrocytes protoporphyrin IX at an animal model during progressive renal disease. A total of 36 eight-week-old male Wistar rats were divided into six groups: Normal, 4 and 8 weeks after 5/6 nephrectomy (NX). Renal function was evaluated by creatinine clearance and plasma creatinine levels. The autofluorescence of erythrocytes porphyrin of healthy and NX rats was analyzed using fluorescence spectroscopy. Emission spectra were obtained by exciting the samples at 405 nm. Significant differences between normal and NX rats autofluorescence shape occurred in the 600–700 nm spectral region. A correlation was observed between emission band intensity at 635 nm and progression of renal disease. 相似文献
118.
Humberto Hinojosa-GómezAuthor Vitae J. Fernando Barragán-ArocheEnrique R. Bazúa-RuedaAuthor Vitae 《Fluid Phase Equilibria》2010
In this work we present two modifications to the Peng–Robinson-Fitted equation of state where pure component parameters are regressed to vapor pressure and saturated liquid density data. The first modification (PR-f-mod) is a method that enhances the equation of state pure component property predictions through simple temperature dependent pure component parameters. In the second modification (PR-f-prop) we propose a temperature dependency for co-volume b in the repulsive parameter of the EoS, and revise the temperature function in the attractive term. The agreement with experimental data for 72 pure substances, including highly polar compounds, is remarkably good. We obtain average absolute deviations in saturated liquid density of less than 1% for all substances studied. 相似文献
119.
Landgrave-Barbosa Fernando Marmolejo-Valencia Andrés F. Baray-Calderón Alejandro Hu Hailin Aguilar-Cordero Julio César Amador-Bedolla Carlos Ugalde-Saldivar Víctor M. 《Journal of Solid State Electrochemistry》2022,26(3):649-661
Journal of Solid State Electrochemistry - A study of poly(3-hexylthiophene) (P3HT) thin films by spin-coating process, deposited on conducting glass substrates of fluorine-doped tin oxide (FTO), is... 相似文献
120.
Ramos Fernando Flores Henoc Camarillo E. Adriana Ledo J. Manuel 《Structural chemistry》2022,33(2):379-388
Structural Chemistry - In the present work, the energy contribution of the sulfur atom in a heterocycle and in a disulfide bond in solid and gas phases was calculated. To achieve this goal,... 相似文献