全文获取类型
收费全文 | 711723篇 |
免费 | 7185篇 |
国内免费 | 2525篇 |
专业分类
化学 | 356043篇 |
晶体学 | 10017篇 |
力学 | 36368篇 |
综合类 | 78篇 |
数学 | 102666篇 |
物理学 | 216261篇 |
出版年
2021年 | 5858篇 |
2020年 | 6467篇 |
2019年 | 7188篇 |
2018年 | 13677篇 |
2017年 | 14035篇 |
2016年 | 15593篇 |
2015年 | 8037篇 |
2014年 | 12518篇 |
2013年 | 29194篇 |
2012年 | 25241篇 |
2011年 | 33991篇 |
2010年 | 24007篇 |
2009年 | 23861篇 |
2008年 | 31335篇 |
2007年 | 33166篇 |
2006年 | 23931篇 |
2005年 | 24288篇 |
2004年 | 21124篇 |
2003年 | 19391篇 |
2002年 | 18291篇 |
2001年 | 18672篇 |
2000年 | 14591篇 |
1999年 | 11059篇 |
1998年 | 9511篇 |
1997年 | 9338篇 |
1996年 | 8969篇 |
1995年 | 8013篇 |
1994年 | 8064篇 |
1993年 | 7727篇 |
1992年 | 8265篇 |
1991年 | 8670篇 |
1990年 | 8233篇 |
1989年 | 8128篇 |
1988年 | 7916篇 |
1987年 | 7623篇 |
1986年 | 7391篇 |
1985年 | 9574篇 |
1984年 | 9943篇 |
1983年 | 8361篇 |
1982年 | 8776篇 |
1981年 | 8203篇 |
1980年 | 7783篇 |
1979年 | 8334篇 |
1978年 | 8707篇 |
1977年 | 8541篇 |
1976年 | 8564篇 |
1975年 | 8112篇 |
1974年 | 8026篇 |
1973年 | 8386篇 |
1972年 | 6190篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
191.
192.
Differential Equations - For the Sturm–Liouville equation of standard form on the complex plane, we study the existence of potentials with monodromy-quasifree singular points, i.e., singular... 相似文献
193.
Santosh S. Bhujbal Chawale Bhushankumar G. Kale Mayuri A. 《Journal of Analytical Chemistry》2022,77(4):473-483
Journal of Analytical Chemistry - HPTLC is a widely used tool in standardization of herbs because of its ability to estimate the presence of active components in samples. HPTLC-bioautography is a... 相似文献
194.
Application of TiO2-nanotubes/PbO2 as an anode for the electrochemical elimination of Acid Red 1 dye
Santos José Eudes L. de Moura Dayanne Chianca da Silva Djalma Ribeiro Panizza Marco Martínez-Huitle Carlos A. 《Journal of Solid State Electrochemistry》2019,23(2):351-360
Journal of Solid State Electrochemistry - In this study, galvanostatic electrolysis, through the use of the platinum supported on Ti (Ti/Pt) and Ti/TiO2-nanotubes/PbO2 anodes, was conducted in an... 相似文献
195.
Stolpovskaya N. V. Kruzhilin A. A. Zorina A. V. Shikhaliev Kh. S. Ledeneva I. V. Kosheleva E. A. Vandyshev D. Yu. 《Russian Journal of Organic Chemistry》2019,55(9):1322-1328
Russian Journal of Organic Chemistry - A procedure has been proposed for the synthesis of a series of substituted N-(1,3-thiazol-2-yl)-pyrimidin-2-amines and N-(pyrimidin-2-yl)thioureas by... 相似文献
196.
Differential Equations - We study a mixed problem for systems of one-dimensional semilinear hyperbolic equations with variable nonlinearity growth rate and nonlinear boundary conditions. Theorems... 相似文献
197.
198.
Adly M. E. Gedawy E. M. El-Malah A. A. El-Telbany F. A. 《Russian Journal of Organic Chemistry》2019,55(8):1189-1196
Russian Journal of Organic Chemistry - Selenopheno[2,3-d]pyrimidine- and selenopheno[2,3-d][1,2,3]triazine-containing compounds were synthesized starting from... 相似文献
199.
Monomeric sarcosine oxidase (mSOx) fusion with the silaffin peptide, R5, designed previously for easy protein production in low resource areas, was used in a biosilification process to form an enzyme layer electrode biosensor. mSOx is a low activity enzyme (10–20 U/mg) requiring high amounts of enzyme to obtain an amperometric biosensor signal, in the clinically useful range <1 mM sarcosine, especially since the Km is >10 mM. An amperometric biosensor model was fitted to experimental data to investigate dynamic range. mSOx constructs were designed with 6H (6×histidine) and R5 (silaffin) peptide tags and compared with native mSOx. Glutaraldehyde (GA) cross‐linked proteins retained ~5 % activity for mSOx and mSOx‐6H and only 0.5 % for mSOx‐R5. In contrast R5 catalysed biosilification on (3‐mercaptopropyl) trimethoxysilane (MPTMS) and tetramethyl orthosilicate (TMOS) particles created a ‘self‐immobilisation’ matrix retaining 40 % and 76 % activity respectively. The TMOS matrix produced a thick layer (>500 μm) on a glassy carbon electrode with a mediated current due to sarcosine in the clinical range for sarcosinemia (0–1 mM). The mSOx‐R5 fusion protein was also used to catalyse biosilification in the presence of creatinase and creatininase, entrapping all three enzymes. A mediated GC enzyme linked current was obtained with dynamic range available for creatinine determination of 0.1–2 mM for an enzyme layer ~800 nm. 相似文献
200.
Manjumol K. A. Jayasankar M. Vidya K. Mohamed A. Peer Nair Balagopal N. Warrier K. G. K. 《Journal of Sol-Gel Science and Technology》2015,74(1):161-167
Journal of Sol-Gel Science and Technology - High temperature stable brookite rich titanium dioxide of average crystallite size 20&;nbsp;nm has been prepared by a novel aqueous sol–gel... 相似文献