全文获取类型
收费全文 | 52573篇 |
免费 | 9207篇 |
国内免费 | 3845篇 |
专业分类
化学 | 47238篇 |
晶体学 | 498篇 |
力学 | 1836篇 |
综合类 | 220篇 |
数学 | 4346篇 |
物理学 | 11487篇 |
出版年
2024年 | 267篇 |
2023年 | 535篇 |
2022年 | 942篇 |
2021年 | 1166篇 |
2020年 | 2253篇 |
2019年 | 3456篇 |
2018年 | 1643篇 |
2017年 | 1231篇 |
2016年 | 3791篇 |
2015年 | 3814篇 |
2014年 | 3918篇 |
2013年 | 4725篇 |
2012年 | 4203篇 |
2011年 | 3587篇 |
2010年 | 3567篇 |
2009年 | 3460篇 |
2008年 | 3208篇 |
2007年 | 2578篇 |
2006年 | 2220篇 |
2005年 | 2164篇 |
2004年 | 1840篇 |
2003年 | 1574篇 |
2002年 | 2181篇 |
2001年 | 1620篇 |
2000年 | 1427篇 |
1999年 | 785篇 |
1998年 | 447篇 |
1997年 | 360篇 |
1996年 | 346篇 |
1995年 | 324篇 |
1994年 | 269篇 |
1993年 | 255篇 |
1992年 | 195篇 |
1991年 | 211篇 |
1990年 | 186篇 |
1989年 | 158篇 |
1988年 | 143篇 |
1987年 | 100篇 |
1986年 | 78篇 |
1985年 | 102篇 |
1984年 | 48篇 |
1983年 | 51篇 |
1982年 | 45篇 |
1981年 | 28篇 |
1980年 | 15篇 |
1979年 | 15篇 |
1978年 | 11篇 |
1977年 | 11篇 |
1976年 | 9篇 |
1973年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
51.
52.
Irene Gouvinhas Nelson Machado Amadeo Girons‐Vilaplana Snia Gomes Teresa Carvalho Raúl Domínguez‐Perles Ana I. R. N. A. Barros 《Journal of Chemometrics》2016,30(9):548-558
The olive tree (Olea europaea L.) can be affected by Colletotrichum acutatum, causing a loss of yield and quality of the final products, whilst the incidence of this fungal infection depends on several factors, including cultivar susceptibility. Thus, the effect of C. acutatum infection in cultivars displaying different susceptibilities to this fungal disease (‘Galega Vulgar’ ‐ susceptible, ‘Cobrançosa’ ‐ moderately susceptible, ‘Picual’ ‐ tolerant) has been assessed through spectrophotometric methods and HPLC, while the FTIR spectra of the cuticles have been concomitantly registered, resorting to the ATR accessory. With the support of multivariate analysis, these spectra allowed to discriminate olives with distinct infection times, besides retrieving evidences concerning the different susceptibility of each cultivar, while these observations were reinforced by the spectrophotometric and chromatographic methods. Furthermore, the assessment of the phenolic profile evidenced individual compounds in the distinct cultivars, so as their variations in response to the fungal infection. 相似文献
53.
54.
Ding Congming Yuan Meini Cao Xiaochen Zheng Lirong Wang Kai 《Journal of Solid State Electrochemistry》2022,26(11):2445-2455
Journal of Solid State Electrochemistry - In order to meet the growing energy demand, it is of great significance to develop high-performance electrochemical energy storage materials. In this... 相似文献
55.
Science China Chemistry - Secrecy has received tremendous attention in modern information society. Innovative polymer-based fluorescent materials with multiple mode emission are quite desirable to... 相似文献
56.
Science China Chemistry - 相似文献
57.
Jia-chang Zhuang Yi-Hua Zhang Ning Song Yu-hui Tan Yun-zhi Tang Yan-Le Huang Hao Zhang Yu-kong Li 《化学:亚洲杂志》2022,17(1):e202101134
Cyclic organic amines are emerging as excellent building blocks to assemble organic–inorganic hybrid phase transition materials due to their flexible cyclic structure. Here, we have assembled a 1D organic-inorganic hybrid dielectric material C5H6NOPbBr3 ( 1 ) by alloying the cyclic organic amine 3-hydroxypyridine. 1 displays a remarkable switchable dielectric response induced by an order-disorder transformation of the organic moiety, this transformation behaviour is confirmed by DSC and Hirshfeld surface measurements. More interestingly, 1 has a narrowband emission (FWHM=4.64 nm) at 590 nm; FWHM is a major quality figure for narrowband photodetectors. In addition, 1 exhibits semiconducting properties with an indirect bandgap of 2.78 eV by the analysis of the UV-Vis absorption results. 相似文献
58.
Alam Nur Tong Li He Zhibin Tang Ruihua Ahsan Laboni Ni Yonghao 《Cellulose (London, England)》2021,28(13):8641-8651
Cellulose - Lateral flow assay (LFA) is an important point-of-care (POC) test platform due to the associated portability, on-site testing, and low cost for diagnosis of pathogen infections and... 相似文献
59.
The recent development of selective oxidation of aromatic sulfides with molecular oxygen was highlighted. The sulfoxides and sulfones could be obtained by simply switching the reaction media, i.e., bis(2-butoxyethyl)ether (BBE) or poly(ethylene glycol)dimethyl ether (PEGDME). The application of the high-boiling-point polyether as an initiator and green media can eliminate the need of large quantities of additives and volatile solvents. This strategy represents an economic and eco-friendly method that could find potential applications. 相似文献
60.
Danlu Xue Chunyi Liu Xiaomin Li Jie Tang Lihua Cao Yi Liu Zhengping Chen 《Journal of Radioanalytical and Nuclear Chemistry》2017,313(2):419-428
We studied on the structural requirement of C11b chirality of tetrabenazine (TBZ) analogs as vesicular monoamine transporter 2 (VMAT2) ligands. TBZ analogs (2, 6a, 6b) and 18F-radiolabeled [18F]6a and [18F]6b with eliminated C11b chirality were synthesized and characterized. Competition studies demonstrated that 2, 6a and 6b displayed much lower in vivo VMAT2 bindings than TBZ. MicroPET imaging studies of [18F]6a and [18F]6b showed negligible accumulation in VMAT2-enriched regions as compared with the known VMAT2 ligand 18F-FP-(+)-DTBZ. These results suggest that C11b chirality of TBZ analogs is essential for in vivo VMAT2 binding bioactivity. 相似文献