全文获取类型
收费全文 | 1419篇 |
免费 | 35篇 |
国内免费 | 8篇 |
专业分类
化学 | 582篇 |
晶体学 | 20篇 |
力学 | 68篇 |
数学 | 269篇 |
物理学 | 523篇 |
出版年
2023年 | 11篇 |
2022年 | 19篇 |
2021年 | 31篇 |
2020年 | 34篇 |
2019年 | 38篇 |
2018年 | 41篇 |
2017年 | 31篇 |
2016年 | 53篇 |
2015年 | 37篇 |
2014年 | 60篇 |
2013年 | 83篇 |
2012年 | 87篇 |
2011年 | 104篇 |
2010年 | 88篇 |
2009年 | 69篇 |
2008年 | 61篇 |
2007年 | 74篇 |
2006年 | 37篇 |
2005年 | 49篇 |
2004年 | 29篇 |
2003年 | 28篇 |
2002年 | 28篇 |
2001年 | 14篇 |
2000年 | 25篇 |
1999年 | 23篇 |
1998年 | 12篇 |
1997年 | 13篇 |
1996年 | 29篇 |
1995年 | 19篇 |
1994年 | 14篇 |
1993年 | 24篇 |
1992年 | 10篇 |
1991年 | 11篇 |
1990年 | 5篇 |
1989年 | 9篇 |
1988年 | 13篇 |
1987年 | 8篇 |
1986年 | 12篇 |
1985年 | 15篇 |
1984年 | 12篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 14篇 |
1980年 | 11篇 |
1979年 | 8篇 |
1978年 | 7篇 |
1977年 | 8篇 |
1976年 | 6篇 |
1974年 | 6篇 |
1973年 | 6篇 |
排序方式: 共有1462条查询结果,搜索用时 0 毫秒
11.
Mukul Biswas Sukhendu K. Das 《Journal of polymer science. Part A, Polymer chemistry》1981,19(12):3155-3164
A new polymeric azodye has been synthesized from carbazole by diazotization of its derivative N-methylcarbazole-3,6-diamine and subsequent coupling reaction with 2,2-bis(4-hydroxyphenyl-3-sulfonate-Na)-propane prepared from bisphenol-A. Its physico-chemical, electrical, and thermal properties have been characterized; finally, its application to the preparation of colored semiconductive films from polyvinyl alcohol has been studied. 相似文献
12.
Mukul Biswas Madhusudan Banerjee Mrinal M. Maiti 《Journal of polymer science. Part A, Polymer chemistry》1984,22(9):1997-2004
Copper(II)-exchanged-13X molecular sieves, prepared from four copper(II) salts, namely, sulfate, nitrate, chloride, and acetate, and their activities in the polymerization of N-vinylcarbazole at a fixed copper ion exchange level were studied. From the kinetic characteristics of polymerization it was established that the variation in activities of the Cu-exchanged sieves is due primarily to the difference in the pH of the original salt solution, which is responsible for the varying degree of proton exchange with the zeolite during copper ion exchange. A first-order dependence of the rate of polymerization was observed with respect to H+ ion concentration of the original copper-salt solution. It was further established that the rate of polymerization of exchanged copper ion, at a hypothetical zero proton concentration, is low. A mechanism of polymerization of NVC on copper-exchanged-13X zeolite was suggested on the basis of the results obtained. 相似文献
13.
The preparation and use of a stainless steel indicator electrode in the accurate potentiometric titration of aqueous hydrogen peroxide are described. The results agree excellently with those obtained by a standard colorimetric weight-titration procedure. The nature of the titration curves, potential changes and the factors affecting them are discussed. Rapid potentiometric titrations directly to the equivalence-point potential are possible, owing to the nature of the titration curve. 相似文献
14.
The enthalpies of formation of the 2,2′-dipyridinium ion and the 2,2′-dipyridyl-iron(II) complex in methanol—water media at 25°C have been determined by caloriumetry. The entropy-changes have been calculated combining the enthalpy values with the corresponding free-energy changes previously reported. The role of solvents on the thermodynamic parameters has been discussed. 相似文献
15.
Mukul Biswas Sukhendu K. Das 《Journal of polymer science. Part A, Polymer chemistry》1981,19(8):2017-2026
A low temperature solution condensation method with pyridine as acceptor-catalytic reagent was applied to the synthesis of polyarylates from carbazole and bisphenol A/phenolphthalein. The polyarylates were classified with respect to their structure, thermal stability, and dielectric behavior. 相似文献
16.
Abachi S Abbott B Abolins M Acharya BS Adam I Adams DL Adams M Ahn S Aihara H Alitti J Álvarez G Alves GA Amidi E Amos N Anderson EW Aronson SH Astur R Avery RE Baarmand MM Baden A Balamurali V Balderston J Baldin B Banerjee S Bantly J Bartlett JF Bazizi K Bendich J Beri SB Bertram I Bezzubov VA Bhat PC Bhatnagar V Bhattacharjee M Bischoff A Biswas N Blazey G Blessing S Bloom P Boehnlein A Bojko NI Borcherding F Borders J Boswell C Brandt A Brock R Bross A Buchholz D Burtovoi VS Butler JM 《Physical review letters》1996,77(4):595-600
17.
Abachi S Abbott B Abolins M Acharya BS Adam I Adams DL Adams M Ahn S Aihara H Alitti J Álvarez G Alves GA Amidi E Amos N Anderson EW Aronson SH Astur R Avery RE Baarmand MM Baden A Balamurali V Balderston J Baldin B Banerjee S Bantly J Bartlett JF Bazizi K Bendich J Beri SB Bertram I Bezzubov VA Bhat PC Bhatnagar V Bhattacharjee M Bischoff A Biswas N Blazey G Blessing S Bloom P Boehnlein A Bojko NI Borcherding F Borders J Boswell C Brandt A Brock R Bross A Buchholz D Burtovoi VS Butler JM 《Physical review letters》1996,77(25):5011-5015
18.
Abachi S Abbott B Abolins M Acharya BS Adam I Adams DL Adams M Ahn S Aihara H Alitti J Álvarez G Alves GA Amidi E Amos N Anderson EW Aronson SH Astur R Avery RE Baden A Balamurali V Balderston J Baldin B Bantly J Bartlett JF Bazizi K Bendich J Beri SB Bertram I Bezzubov VA Bhat PC Bhatnagar V Bhattacharjee M Bischoff A Biswas N Blazey G Blessing S Bloom P Boehnlein A Bojko NI Borcherding F Borders J Boswell C Brandt A Brock R Bross A Buchholz D Burtovoi VS Butler JM Carvalho W Casey D 《Physical review letters》1996,76(18):3271-3276
19.
Alexopoulos T Allen C Anderson EW Balamurali V Banerjee S Beery PD Bhat P Bishop JM Biswas NN Bujak A Carmony DD Carter T Choi Y Cole P DeBonte R DeCarlo V Erwin AR Findeisen C Goshaw AT Gutay LJ Hirsch AS Hojvat C Jennings JR Kenney VP Lindsey CS Loomis C LoSecco JM McMahon T McManus AP Morgan N Nelson K Oh SH Porile NT Reeves D Rimai A Robertson WJ Scharenberg RP Stampke SR Stringfellow BC Thompson M Turkot F Walker WD Wang CH Warchol J Wesson DK Zhan Y 《Physical review D: Particles and fields》1993,48(3):984-997
20.
Bankim C. Das I. Dey G. Biswas R. Banerjee Y. Iitaka A. Banerjee 《Journal of chemical crystallography》1993,23(6):509-512
The crystal structure of C6H16N8O2·CuCl2, a biguanide metal complex, has been determined by X-ray diffraction data using MoK radiation. The compound crystallizes in the monoclinic space groupP21/a, witha=11.074(4),b=12.061(4),c=5.312(3)Å and=102.8(1)°.The structure was solved by direct methods and refined by full-matrix least-squares to a finalR value 0.037 with 1245 unique reflections. The complex molecule is centrosymmetric, with the Cu atom (0.5,0.5,0.5) on a crystallographic center of symmetry. The complex molecule is rhombic planar with a trans configuration. 相似文献