全文获取类型
收费全文 | 1004篇 |
免费 | 27篇 |
国内免费 | 10篇 |
专业分类
化学 | 716篇 |
晶体学 | 5篇 |
力学 | 24篇 |
数学 | 103篇 |
物理学 | 193篇 |
出版年
2024年 | 4篇 |
2023年 | 5篇 |
2022年 | 6篇 |
2021年 | 42篇 |
2020年 | 19篇 |
2019年 | 23篇 |
2018年 | 33篇 |
2017年 | 25篇 |
2016年 | 30篇 |
2015年 | 26篇 |
2014年 | 33篇 |
2013年 | 83篇 |
2012年 | 54篇 |
2011年 | 54篇 |
2010年 | 51篇 |
2009年 | 50篇 |
2008年 | 53篇 |
2007年 | 64篇 |
2006年 | 46篇 |
2005年 | 48篇 |
2004年 | 58篇 |
2003年 | 33篇 |
2002年 | 41篇 |
2001年 | 11篇 |
2000年 | 9篇 |
1999年 | 13篇 |
1997年 | 9篇 |
1996年 | 12篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1991年 | 7篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 10篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1980年 | 8篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 4篇 |
1962年 | 2篇 |
排序方式: 共有1041条查询结果,搜索用时 125 毫秒
31.
Abd-Rabbou M. Y. Khalil E. M. Ahmed M. M. A. Obada A.-S. F. 《International Journal of Theoretical Physics》2019,58(12):4012-4024
International Journal of Theoretical Physics - The interaction between a moving two-level atom and squeezed coherent states in the presence of Kerr like medium and an external classical field is... 相似文献
32.
33.
In order to synthesize new polyamide(PA) 5 and copolyamides(Co PA) 7a-7d, a new-type of dicarboxylic acid containing triazine ring was successfully synthesized from 2,4-dichloro-6-methoxy-s-triazine 1 and 4-aminobenzoic acid. New polyamide 5 containing triazine moiety was prepared from 4,4'-(6-methoxy-1,3,5-triazine-2,4-diyl)bis(azanediyl)dibenzoic acid 3 and 4,4′-diaminodiphenylether by direct polycondensation reaction. Then new series thermally stable copolyamides 7a-7d with high solubility in common organic solvents were synthesized from the direct polycondensation reaction of diacid 3 as a first monomer, aliphatic-aromatic diacids 6a-6d as second diacids and 4,4′-diaminodiphenylether. All of the above polymers were fully characterized by 1H-NMR and FTIR spectroscopy, elemental analysis(CHN), inherent viscosity, solubility tests, gel permeation chromatography(GPC), differential scanning calorimetry(DSC) and thermogravimetric analysis(TGA). The resulted Co PAs 7a-7d have shown good inherent viscosities, solubility and thermal properties. 相似文献
34.
35.
36.
Abdulnasir A. Majeed Mostafa M.H. Khalil Ahmed Fetoh Ayman A. Abdel Aziz G.M. Abu El‐Reash 《应用有机金属化学》2021,35(1)
In this work, (Z)‐N‐benzoyl‐N′‐(1H‐1,2,4‐triazol‐3‐yl)carbamimidothioic acid and its Mn(II), Co(II), Cu(II) and Cd(II) complexes were introduced for the first time. This carbonyl thiourea ligand was prepared by the reaction of 1H‐1,2,4‐triazol‐3‐amine with benzoyl isothiocyanate. The structural elucidation of these compounds was performed using elemental analysis and spectral and magnetic measurements. Octahedral structures of all complexes, except Cd(II) complex with a tetrahedral geometry, were confirmed by applying DFT structural optimization. The thermal decomposition behaviour of metal complexes of carbonyl thiourea ligand is discussed. The calculation of kinetic parameters for prepared complexes (Ea, A, ΔH*, ΔS* and ΔG*) of all thermal degradation stages has been evaluated using two comparable approaches. Antimicrobial and ABTS‐antioxidant studies indicated potent activity of Cd(II) complex compared with the other investigated compounds. The cytotoxic activity of the prepared compounds was investigated in vitro. The results indicated potent activity of Mn(II) complex against both HePG2 (liver carcinoma) and MCF‐7 (breast carcinoma) cancer cells. 相似文献
37.
Brahim Khemaies Rouissi Khalil Soussi-Baatout Amira Khattech Ismail 《Journal of Thermal Analysis and Calorimetry》2021,143(4):3173-3179
Journal of Thermal Analysis and Calorimetry - The thermochemical and kinetic studies of diammonium hydrogen phosphate precipitation in phosphoric acid with ammonia were followed using a... 相似文献
38.
I. V. Amirkhanov A. S. Khalil I. Sarkhadov 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2013,7(4):711-718
Numerical simulation of the thermal processes occurring in indium phosphide under the action of a heavy gold ion with the energy E 0 = 200 MeV is carried out. The problem is solved taking into account phase transitions of the melting and evaporation types. Numerical studies are carried out on the basis of a modified thermal-peak model and the obtained results are analyzed. 相似文献
39.
40.