全文获取类型
收费全文 | 391265篇 |
免费 | 20662篇 |
国内免费 | 14745篇 |
专业分类
化学 | 216825篇 |
晶体学 | 4780篇 |
力学 | 14151篇 |
综合类 | 783篇 |
数学 | 75367篇 |
物理学 | 114766篇 |
出版年
2023年 | 4491篇 |
2022年 | 6245篇 |
2021年 | 9864篇 |
2020年 | 10192篇 |
2019年 | 8603篇 |
2018年 | 12027篇 |
2017年 | 12281篇 |
2016年 | 10474篇 |
2015年 | 11625篇 |
2014年 | 16906篇 |
2013年 | 25715篇 |
2012年 | 22262篇 |
2011年 | 23209篇 |
2010年 | 19189篇 |
2009年 | 19343篇 |
2008年 | 19873篇 |
2007年 | 20708篇 |
2006年 | 18714篇 |
2005年 | 14619篇 |
2004年 | 12570篇 |
2003年 | 11254篇 |
2002年 | 10298篇 |
2001年 | 10369篇 |
2000年 | 7650篇 |
1999年 | 6995篇 |
1998年 | 5551篇 |
1997年 | 4762篇 |
1996年 | 4016篇 |
1995年 | 2625篇 |
1994年 | 2393篇 |
1993年 | 2378篇 |
1992年 | 2144篇 |
1991年 | 2740篇 |
1990年 | 2805篇 |
1989年 | 2376篇 |
1988年 | 2303篇 |
1987年 | 2331篇 |
1986年 | 2097篇 |
1985年 | 2896篇 |
1984年 | 2915篇 |
1983年 | 2247篇 |
1982年 | 2604篇 |
1981年 | 2372篇 |
1980年 | 2037篇 |
1979年 | 2175篇 |
1978年 | 2349篇 |
1977年 | 2084篇 |
1976年 | 2078篇 |
1975年 | 2003篇 |
1973年 | 2049篇 |
排序方式: 共有10000条查询结果,搜索用时 929 毫秒
1.
Avdic Senada Demirovic Damir Hadzimustafic Edin Cickusic Zerina Sehic Faruk 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(6):2645-2654
Journal of Radioanalytical and Nuclear Chemistry - Responses of the hand-held gamma monitors available for the ambient dose equivalent rate measurements in the Federation of Bosnia and Herzegovina... 相似文献
2.
以氧化石墨烯(GO)为原料, 利用温和方法制备了3种不同还原程度的部分还原氧化石墨烯pRGO1, pRGO2和pRGO3(pRGO1—3); 利用傅里叶变换红外光谱(FTIR)、 拉曼光谱(Raman)、 X 射线光电子能谱(XPS)、 紫外-可见光谱(UV-Vis)、 透射电子显微镜(TEM)和 EDS能谱对其结构和形貌进行了表征. 细胞实验结果表明, 无激光照射下pRGO1—3本身的细胞毒性较低; 近红外(NIR)激光照射下pRGO1—3通过光热和光毒性双重作用杀伤肿瘤细胞. 实验结果显示了pRGO 在肿瘤光热疗法和光动力疗法领域的应用潜力. 相似文献
3.
Kinetics and Catalysis - The catalytic properties of a nickel phosphide catalyst supported on silica gel in the reductive amination of carbonyl compounds were studied in a flow reactor using... 相似文献
4.
Patrick Imrie Jianyong Jin 《Journal of polymer science. Part A, Polymer chemistry》2022,60(2):149-174
4D printing is an exciting branch of additive manufacturing. It relies on established 3D printing techniques to fabricate objects in much the same way. However, structures which fall into the 4D printed category have the ability to change with time, hence the “extra dimension.” The common perception of 4D printed objects is that of macroscopic single-material structures limited to point-to-point shape change only, in response to either heat or water. However, in the area of polymer 4D printing, recent advancements challenge this understanding. A host of new polymeric materials have been designed which display a variety of wonderful effects brought about by unconventional stimuli, and advanced additive manufacturing techniques have been developed to accommodate them. As a result, the horizons of polymer 4D printing have been broadened beyond what was initially thought possible. In this review, we showcase the many studies which evolve the very definition of polymer 4D printing, and reveal emerging areas of research integral to its advancement. 相似文献
5.
Yang T. L. Kao C. L. Kuo C. E. Yeh H. C. Li W. J. Li H. T. Chen C. Y. 《Chemistry of Natural Compounds》2022,58(5):825-827
Chemistry of Natural Compounds - A novel bibenzyl derivative, hydrangchinenin (1), was isolated from the stems of Hydrangea chinensis Maxim. (Hydrangeaceae). Its structure was determined on the... 相似文献
6.
《Mendeleev Communications》2022,32(5):597-600
Calorimetric monitoring of the autoclave reaction N2O4 + C2H4 at –85 to +10 °C under argon pressure 10–30 bar revealed that the exothermic chemical reaction started at temperatures above –52 °C at 10 bar, whereas an intensive exothermic reaction started at –85 °C and pressure of 30 bar. IR study showed that oligo/polynitroethylene was formed at 30 bar, while carbonyl and hydroxy compound as well as nitrate R–ONO2 formation occurred upon processing at 10 bar. 相似文献
7.
Soltani Rad Mohammad Navid Behrouz Somayeh Mohammad-Javadi Mehdi Zarenezhad Elham 《Molecular diversity》2022,26(5):2503-2521
Molecular Diversity - The preparation, characterization and application of hydroxyapatite silica propyl bis aminoethoxy ethane cuprous complex (HASPBAEECC) as a novel hybrid nano-catalyst for... 相似文献
8.
Rastsvetaeva R. K. Chukanov N. V. Pekov I. V. Varlamov D. A. Kazheva O. N. 《Crystallography Reports》2022,67(2):166-171
Crystallography Reports - The crystal structure and crystallochemical features of a Fe-deficient zirconium-rich analog of eudialyte from the Lovozero alkaline massif (Kola peninsula) have been... 相似文献
9.
JETP Letters - A new approach to search for axions in the storage ring experiments, applicable at a short coherence time of the in-plane polarization as is the case for protons is discussed. The... 相似文献
10.
Shilin Jiang Dr. Yalan Liu Dr. Lin Wang Prof. Zhifang Chai Prof. Wei-Qun Shi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(60):e202201145
The coordination chemistry of f-block elements (lanthanide and actinide) in molten salts has become a resounding topic in view of its great importance to the research and development (R&D) of molten salt reactors and pyroprocessing. In this Review article, a general overview of the coordination chemistry of f-block elements in molten salts is provided including past achievements and recent advances. Particular emphases are placed on the oxidation state, speciation, and solution structure of f-block metal ions in molten salts, as well as their relationships with the salt composition. Furthermore, this review briefly discusses the spectroscopic and theoretical methods that complement each other in revealing the coordination properties. 相似文献