全文获取类型
收费全文 | 4291篇 |
免费 | 122篇 |
国内免费 | 10篇 |
专业分类
化学 | 2613篇 |
晶体学 | 43篇 |
力学 | 229篇 |
数学 | 609篇 |
物理学 | 929篇 |
出版年
2023年 | 58篇 |
2022年 | 64篇 |
2021年 | 133篇 |
2020年 | 121篇 |
2019年 | 91篇 |
2018年 | 160篇 |
2017年 | 197篇 |
2016年 | 190篇 |
2015年 | 181篇 |
2014年 | 170篇 |
2013年 | 227篇 |
2012年 | 295篇 |
2011年 | 317篇 |
2010年 | 312篇 |
2009年 | 303篇 |
2008年 | 226篇 |
2007年 | 239篇 |
2006年 | 251篇 |
2005年 | 170篇 |
2004年 | 93篇 |
2003年 | 94篇 |
2002年 | 97篇 |
2001年 | 116篇 |
2000年 | 61篇 |
1999年 | 82篇 |
1998年 | 45篇 |
1997年 | 24篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 9篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1985年 | 8篇 |
1984年 | 16篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 7篇 |
1979年 | 8篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1970年 | 2篇 |
排序方式: 共有4423条查询结果,搜索用时 30 毫秒
1.
Dr. Sirinapa Wongwilawan Dr. Doyun Kim Dr. Thien S. Nguyen Wonki Lim Prof. Dr. Sheng Li Prof. Dr. Cafer T. Yavuz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(72):e202202340
Through accumulation, mercury contamination in aquatic systems still poses serious health risks despite the strict regulations on drinking water and industrial discharge. One effective strategy against this is adsorptive removal, in which a suitably functionalized porous material is added to water treatment protocols. Thiol (SH) group-grafted structures perform commendably; however, insufficient attention is paid to the cost, scalability, and reusability or how the arrangement of sulfur atoms could affect the HgII binding strength. We used an inexpensive and scalable porous covalent organic polymer (COP-130) to systematically introduce thiol functional groups with precise chain lengths and sulfur content. Thiol-functionalized COP-130 demonstrates enhanced wettability and excellent HgII uptake of up to 936 mg g−1, with fast kinetics and exceptionally high selectivity. These Hg adsorbents are easily regenerated with HCl and can be used at least six times without loss of capacity even after treatment with strong acid, a rare performance in the domain of Hg-removal research. 相似文献
2.
3.
4.
《Arabian Journal of Chemistry》2022,15(10):104145
In the present study, novel representatives of the important group of biologically-active, dehydroabietic acid-bearing dithiocarbamate moiety, were synthesized and characterized by 1H NMR, 13C NMR, HR-MS. The in vitro antiproliferative activity evaluation (MTT) indicated that these compounds exhibited potent inhibitory activities in various cancer cell lines (HepG-2, MCF-7, HeLa, T-24, MGC-803). Particularly, compound III-b possessed extraordinary cytotoxicity with low micromolar IC50 values ranging from 4.07 to 38.84 µM against tested cancer cell lines, while displayed weak cytotoxicity on two normal cell lines (LO-2 and HEK 293 T). Subsequently, the potential mechanisms of representative compound III-b were elementarily investigated by Transwell experiment, which showed III-b can inhibit cancer cells migration. Annexin-V/PI dual staining showed that the compound can induce HepG-2 cells apoptosis in a dose-dependent manner. Meanwhile this apoptosis may be related to the upregulated protein expression of cleaved-caspase 3, cleaved-caspase 9, Bax and downregulated of Bcl-2 indicated by Western Blot. Later study further confirmed that ROS levels in HepG-2 cells increased significantly with the rise of concentrations. In addition, through the network pharmacology data analyzing, the core targets and signaling pathways of compound III-b for treatment of liver neoplasms were forecasted. Molecular docking model showed that compound III-b had high affinity with hub targets (CASP3, EGFR, HSP90AA1, MAPK1, ERBB2, MDM2), suggesting that compound III-b might target the hub protein to modulate signaling activity. Taken together, these data indicated that dehydroabietic acid structural modification following the “Molecular hybridization” principle is a feasible way to discover the potential multi-targeted antitumor compounds. 相似文献
5.
6.
Tharita Kitisripanya Witcha Sermpradit Seiichi Sakamoto Hiroyuki Tanaka Waraporn Putalun 《Biomedical chromatography : BMC》2020,34(2):e4718
There have been reports of fake artesunate (ART), which has led to deaths from untreated malaria in South East Asia. To rapidly screen for fake and adulterated ART products in the drug market, a lateral flow immunoassay (LFIA) based on a colloidal gold–monoclonal antibody probe for detection of ART within samples was developed. With this method, the calibration curve for ART was determined by the intensity ratio of the test and control bands at various ART concentrations. The linearity range was 12.5–200 μg/ml of ART. Samples were tested by the developed LFIA and can be calculated for ART contents. The levels of ART in the samples were also confirmed by enzyme-linked immunosorbent assay. The results of the two methods were in good conformance. The proposed LFIA was demonstrated to be a simple and rapid analytical method for detecting ART in the pharmaceutical formulation. 相似文献
7.
The dependence of the EPR g-factors on the local structural parameter for a 4f11 configuration ion Er3+ in a trigonal crystal-field has been studied by diagonalizing the 364×364 complete energy matrices. Our studies indicate that the EPR spectra of the trigonal Er3+–VK centers in KMgF3 and KZnF3 may be attributed to the translation of the cubic Kramers doublet Γ7. Furthermore, the EPR g-factors of the trigonal Er3+–VK centers may be interpreted reasonably by the shifts ΔZ≈0.340 Å and ΔZ≈0.303 Å of the Er3+ ions toward the charge compensator VK along the C3 axis for the KMgF3:Er3+ and the KZnF3:Er3+ systems respectively. 相似文献
8.
9.
10.
Dalkılıç Ahmet Selim Mercan Hatice Özçelik Güven Wongwises Somchai 《Journal of Thermal Analysis and Calorimetry》2021,143(2):859-878
Journal of Thermal Analysis and Calorimetry - The heat exchanger pipe diameter has a significant effect on the flow characteristics as well as on the initial investment, operation and overall cost.... 相似文献