全文获取类型
收费全文 | 1981篇 |
免费 | 56篇 |
国内免费 | 6篇 |
专业分类
化学 | 1338篇 |
晶体学 | 19篇 |
力学 | 45篇 |
数学 | 128篇 |
物理学 | 513篇 |
出版年
2024年 | 20篇 |
2023年 | 36篇 |
2022年 | 62篇 |
2021年 | 54篇 |
2020年 | 49篇 |
2019年 | 53篇 |
2018年 | 50篇 |
2017年 | 61篇 |
2016年 | 89篇 |
2015年 | 47篇 |
2014年 | 67篇 |
2013年 | 180篇 |
2012年 | 136篇 |
2011年 | 141篇 |
2010年 | 85篇 |
2009年 | 84篇 |
2008年 | 110篇 |
2007年 | 81篇 |
2006年 | 54篇 |
2005年 | 61篇 |
2004年 | 45篇 |
2003年 | 28篇 |
2002年 | 41篇 |
2001年 | 25篇 |
2000年 | 23篇 |
1999年 | 18篇 |
1998年 | 7篇 |
1997年 | 15篇 |
1996年 | 17篇 |
1995年 | 20篇 |
1994年 | 14篇 |
1993年 | 21篇 |
1992年 | 7篇 |
1991年 | 11篇 |
1990年 | 12篇 |
1989年 | 14篇 |
1988年 | 14篇 |
1987年 | 7篇 |
1986年 | 7篇 |
1985年 | 13篇 |
1984年 | 16篇 |
1983年 | 16篇 |
1982年 | 8篇 |
1981年 | 11篇 |
1980年 | 15篇 |
1979年 | 16篇 |
1978年 | 15篇 |
1977年 | 19篇 |
1974年 | 6篇 |
1973年 | 9篇 |
排序方式: 共有2043条查询结果,搜索用时 15 毫秒
61.
62.
Augustine Elizabeth Desigan N. Pandey N. K. Joshi J. B. 《Journal of Radioanalytical and Nuclear Chemistry》2020,324(1):211-218
Journal of Radioanalytical and Nuclear Chemistry - In the present study, the dissolution kinetics of UO2 pellets in nitric acid has been investigated. Kinetic rate expressions based on... 相似文献
63.
Sharma Abhishek K. Agrahari Gaurav Tiwari C. B. Tomar B. S. Yelgaonkar V. N. 《Journal of Radioanalytical and Nuclear Chemistry》2020,324(1):143-147
Journal of Radioanalytical and Nuclear Chemistry - In the traditional medicine of Iran, some herbal medicines are used for treating of high blood sugar. In this study, the concentration of Ca, Cr,... 相似文献
64.
Sharma Deepika Radha Anu Kumar Pretam Kumar Sandeep Jassal Amanpreet K. Lata Suman Vikas Pandey Sushil K. 《Transition Metal Chemistry》2020,45(8):531-544
Transition Metal Chemistry - Nickel(II) complexes with octahedral coordination stabilized by N-donor ligands corresponds to [{(ArO)2PS2}2Ni·L2] [Ar = 4-(C2H5)C6H4 (3), and... 相似文献
65.
Dr. Abshar Hasan Dr. Kyueui Lee Dr. Kunal Tewari Prof. Lalit M. Pandey Prof. Phillip B. Messersmith Prof. Karen Faulds Dr. Michelle Maclean Dr. King Hang Aaron Lau 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(26):5789-5793
Microbial surface attachment negatively impacts a wide range of devices from water purification membranes to biomedical implants. Mimics of antimicrobial peptides (AMPs) constituted from poly(N-substituted glycine) „peptoids“ are of great interest as they resist proteolysis and can inhibit a wide spectrum of microbes. We investigate how terminal modification of a peptoid AMP-mimic and its surface immobilization affect antimicrobial activity. We also demonstrate a convenient surface modification strategy for enabling alkyne–azide „click“ coupling on amino-functionalized surfaces. Our results verified that the N- and C-terminal peptoid structures are not required for antimicrobial activity. Moreover, our peptoid immobilization density and choice of PEG tether resulted in a „volumetric“ spatial separation between AMPs that, compared to past studies, enabled the highest AMP surface activity relative to bacterial attachment. Our analysis suggests the importance of spatial flexibility for membrane activity and that AMP separation may be a controlling parameter for optimizing surface anti-biofouling. 相似文献
66.
Narayan D. Chaurasiya Jacob Midiwo Pankaj Pandey Regina N. Bwire Robert J. Doerksen Ilias Muhammad Babu L. Tekwani 《Molecules (Basel, Switzerland)》2020,25(22)
A set of structurally related O-methylated flavonoid natural products isolated from Senecio roseiflorus (1), Polygonum senegalense (2 and 3), Bhaphia macrocalyx (4), Gardenia ternifolia (5), and Psiadia punctulata (6) plant species were characterized for their interaction with human monoamine oxidases (MAO-A and -B) in vitro. Compounds 1, 2, and 5 showed selective inhibition of MAO-A, while 4 and 6 showed selective inhibition of MAO-B. Compound 3 showed ~2-fold selectivity towards inhibition of MAO-A. Binding of compounds 1–3 and 5 with MAO-A, and compounds 3 and 6 with MAO-B was reversible and not time-independent. The analysis of enzyme-inhibition kinetics suggested a reversible-competitive mechanism for inhibition of MAO-A by 1 and 3, while a partially-reversible mixed-type inhibition by 5. Similarly, enzyme inhibition-kinetics analysis with compounds 3, 4, and 6, suggested a competitive reversible inhibition of MAO-B. The molecular docking study suggested that 1 selectively interacts with the active-site of human MAO-A near N5 of FAD. The calculated binding free energies of the O-methylated flavonoids (1 and 4–6) and chalcones (2 and 3) to MAO-A matched closely with the trend in the experimental IC50′s. Analysis of the binding free-energies suggested better interaction of 4 and 6 with MAO-B than with MAO-A. The natural O-methylated flavonoid (1) with highly potent inhibition (IC50 33 nM; Ki 37.9 nM) and >292 fold selectivity against human MAO-A (vs. MAO-B) provides a new drug lead for the treatment of neurological disorders. 相似文献
67.
68.
Divakar Vishwanath Swamy S. Girimanchanaika Dukanya Dukanya Shobith Rangappa Ji-Rui Yang Vijay Pandey Peter E. Lobie Basappa Basappa 《Molecules (Basel, Switzerland)》2022,27(3)
Novel PARP inhibitors with selective mode-of-action have been approved for clinical use. Herein, oxadiazole based ligands that are predicted to target PARP-1 have been synthesized and screened for the loss of cell viability in mammary carcinoma cells, wherein seven compounds were observed to possess significant IC50 values in the range of 1.4 to 25 µM. Furthermore, compound 5u, inhibited the viability of MCF-7 cells with an IC50 value of 1.4µM, when compared to Olaparib (IC50 = 3.2 µM). Compound 5s also decreased cell viability in MCF-7 and MDA-MB-231 cells with IC50 values of 15.3 and 19.2 µM, respectively. Treatment of MCF-7 cells with compounds 5u and 5s produced PARP cleavage, H2AX phosphorylation and CASPASE-3 activation comparable to that observed with Olaparib. Compounds 5u and 5s also decreased foci-formation and 3D Matrigel growth of MCF-7 cells equivalent to or greater than that observed with Olaparib. Finally, in silico analysis demonstrated binding of compound 5s towardsthe catalytic site of PARP-1, indicating that these novel oxadiazoles synthesized herein may serve as exemplars for the development of new therapeutics in cancer. 相似文献
69.
70.
U. Pandey A. Mukherjee G. Samuel S. Banerjee H. D. Sarma M. Venkatesh 《Journal of Radioanalytical and Nuclear Chemistry》2008,275(2):243-246
Lanreotide, a somatostatin analogue, was radioiodinated with 125I to explore the possibility of using 123I labeled lanreotide as a diagnostic radiopharmaceutical for tumors overexpressing somatostatin (SST) receptors. Radioiodination
was carried out with 125I using chloramine T as the oxidant. The labeling yield was >90%. Characterization of 125I-Lanreotide was carried out by paper electrophoresis as well as HPLC. 125I-Lanreotide was purified by chromatography using a C18 Sep-Pak column. Radiochemical purity of the purified 125I-Lanreotide thus obtained was >99%. Significant tumor uptake of 125I-Lanreotide was observed in C57BL/6 mice bearing melanoma. 相似文献