全文获取类型
收费全文 | 248396篇 |
免费 | 2636篇 |
国内免费 | 599篇 |
专业分类
化学 | 128839篇 |
晶体学 | 3646篇 |
力学 | 10023篇 |
综合类 | 6篇 |
数学 | 31009篇 |
物理学 | 78108篇 |
出版年
2021年 | 2352篇 |
2020年 | 2752篇 |
2019年 | 2846篇 |
2018年 | 3607篇 |
2017年 | 3417篇 |
2016年 | 5349篇 |
2015年 | 3606篇 |
2014年 | 4872篇 |
2013年 | 11917篇 |
2012年 | 9858篇 |
2011年 | 11177篇 |
2010年 | 7676篇 |
2009年 | 7287篇 |
2008年 | 10063篇 |
2007年 | 10038篇 |
2006年 | 9459篇 |
2005年 | 8712篇 |
2004年 | 7987篇 |
2003年 | 6922篇 |
2002年 | 6617篇 |
2001年 | 7226篇 |
2000年 | 5770篇 |
1999年 | 4389篇 |
1998年 | 3509篇 |
1997年 | 3441篇 |
1996年 | 3319篇 |
1995年 | 2993篇 |
1994年 | 2912篇 |
1993年 | 2743篇 |
1992年 | 3132篇 |
1991年 | 3043篇 |
1990年 | 2993篇 |
1989年 | 2730篇 |
1988年 | 2782篇 |
1987年 | 2751篇 |
1986年 | 2575篇 |
1985年 | 3372篇 |
1984年 | 3595篇 |
1983年 | 2927篇 |
1982年 | 3102篇 |
1981年 | 3083篇 |
1980年 | 2891篇 |
1979年 | 2983篇 |
1978年 | 3074篇 |
1977年 | 3065篇 |
1976年 | 3144篇 |
1975年 | 2894篇 |
1974年 | 2879篇 |
1973年 | 3016篇 |
1972年 | 1906篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
Potapov I. D. Voznarskiy A. Yu. Mironov A. V. Motyakin M. V. Nekipelova T. D. Podrugina T. A. 《Russian Chemical Bulletin》2022,71(5):1027-1033
Russian Chemical Bulletin - A new approach to the synthesis of λ5-phosphinolines was developed consisting in the reaction of mixed phosphonium-iodonium ylides with acetylenes in the presence... 相似文献
82.
do Nascimento Ticiano Gomes Borges Arthur Luy Tavares Ferreira de Almeida Lara Mendes Ribeiro Êurica Adélia Nogueira Silva Fernanda Geny Calheiros da Costa Silva Valdemir do Nascimento Prata Ana Paula Basílio-Júnior Irinaldo Diniz Goulart Marília Oliveira Fonseca Morilla Demetrius Peireira de Freitas Johnnatan Duarte Aragão Cícero Flávio Soares 《Journal of Thermal Analysis and Calorimetry》2022,147(21):11949-11963
Journal of Thermal Analysis and Calorimetry - This work prepared and characterized microcapsule of Uncaria tomentosa (UT) in order to standardize a spray-dryer Uncaria tomentosa extract. The UT... 相似文献
83.
Dr. Susana Ibáñez Prof. Eduardo Peris 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(37):9661-9665
The use of a carbazolyl-connected di-gold(I) metallotweezer for the encapsulation of several electron-poor organic substrates, and a planar Au(III) complex containing a CNC pincer ligand, is described. The binding affinity of the receptor depends on the electron-deficient character of the planar guest, with larger association constants found for the more electron-poor guests. The X-ray diffraction molecular structures of two host:guest adducts show that the host approaches its arms in order to facilitate the optimum interaction with the surface of the planar guests, in a clear example of an guest-induced fit conformational arrangement. The electrochemical studies of the encapsulation of N,N’-dimethyl-naphthalenetetracarboxy diimide (NTCDI) show that the redox active guest is released from the receptor upon one electron reduction, thus constituting an example of redox-switchable binding. 相似文献
84.
Ukhin L. Yu. Kuz’mina L. G. Alexeenko D. V. Belousova L. V. Gribanova T. N. Morkovnik A. S. Shepelenko E. N. Borodkin G. S. Dmitrieva O. I. Podshibyakin V. A. 《Russian Chemical Bulletin》2021,70(7):1368-1376
Russian Chemical Bulletin - New potential biologically active derivatives, in which the sterically hindered pyrocatechol moiety is linked through a 2-thioacetyl covalent bridge to a number of... 相似文献
85.
Dyachenko I. V. Dyachenko V. D. Dorovatovskii P. V. Khrustalev V. N. Nenajdenko V. G. 《Russian Chemical Bulletin》2021,70(11):2145-2155
Russian Chemical Bulletin - The tandem Knoevenagel—Michael—intramolecular ammonolysis—alkylation reaction was used to synthesize functionalized tetrahydropyridones. The molecular... 相似文献
86.
Novakov I. A. Sheikin D. S. Ruchko E. A. Brunilina L. L. Vernigora A. A. Salykin N. A. Vostrikova O. V. Chapurkin V. V. Nawrozkij M. B. Kurkin D. V. Bakulin D. A. Vorontsov M. Yu. Sablina L. A. Kovalev N. S. Tyurenkov I. N. 《Russian Chemical Bulletin》2021,70(11):2220-2226
Russian Chemical Bulletin - Novel structural analogs of isothiobarbamine, which differ from the prototype scaffold by the substituent at position 2 of the pyrimidine heterocycle, were for the first... 相似文献
87.
Specific features of coupling reactions of polystyrene in the presence α-dinitrones based on glyoxal
Kolyakina E. V. Shoipova F. H. Alyeva A. B. Grishin D. F. 《Russian Chemical Bulletin》2021,70(9):1736-1745
Russian Chemical Bulletin - Bromine-containing polystyrene synthesized by atom transfer radical polymerization was used as a model to study coupling reactions in the presence of such free radical... 相似文献
88.
Rozentsvet V. A. Sablina N. A. Ulyanova D. M. Smirnov S. N. Tolstoy P. M. 《Russian Chemical Bulletin》2021,70(4):773-779
Russian Chemical Bulletin - The structure of polymer chain of poly(1,3-pentadiene) synthesized via a stereospecific polymerization catalyzed by a system based on neodymium trichloride was... 相似文献
89.
Lazarev S. I. Kovalev S. V. Konovalov D. N. Lua P. 《Russian Journal of Electrochemistry》2021,57(6):607-624
Russian Journal of Electrochemistry - Electrochemical and transport characteristics of systems equipped with OPMN-P and OFAM-K membranes during operation in electronanofiltration cell are studied... 相似文献
90.
Nikiforova E. A. Makhmudov R. R. Rudin A. A. Dmitriev M. V. Baibarodskikh D. V. Kirillov N. F. Zverev D. P. Romanov A M. 《Russian Journal of General Chemistry》2021,91(1):64-71
Russian Journal of General Chemistry - Depending on the ring size in the Reformatsky reagent and the nature of substituents in arylmethylidene fragment, the reactions of Reformatsky reagents... 相似文献