全文获取类型
收费全文 | 12345篇 |
免费 | 427篇 |
国内免费 | 22篇 |
专业分类
化学 | 8096篇 |
晶体学 | 72篇 |
力学 | 174篇 |
数学 | 2058篇 |
物理学 | 2394篇 |
出版年
2023年 | 106篇 |
2022年 | 245篇 |
2021年 | 321篇 |
2020年 | 262篇 |
2019年 | 224篇 |
2018年 | 241篇 |
2017年 | 269篇 |
2016年 | 587篇 |
2015年 | 445篇 |
2014年 | 482篇 |
2013年 | 980篇 |
2012年 | 741篇 |
2011年 | 875篇 |
2010年 | 553篇 |
2009年 | 483篇 |
2008年 | 566篇 |
2007年 | 513篇 |
2006年 | 393篇 |
2005年 | 345篇 |
2004年 | 287篇 |
2003年 | 265篇 |
2002年 | 261篇 |
2001年 | 135篇 |
2000年 | 109篇 |
1999年 | 121篇 |
1998年 | 110篇 |
1997年 | 116篇 |
1996年 | 106篇 |
1995年 | 101篇 |
1994年 | 81篇 |
1993年 | 79篇 |
1992年 | 80篇 |
1991年 | 76篇 |
1988年 | 70篇 |
1987年 | 79篇 |
1986年 | 72篇 |
1985年 | 96篇 |
1984年 | 96篇 |
1983年 | 83篇 |
1982年 | 74篇 |
1981年 | 72篇 |
1980年 | 86篇 |
1979年 | 76篇 |
1978年 | 85篇 |
1977年 | 86篇 |
1976年 | 64篇 |
1974年 | 69篇 |
1973年 | 75篇 |
1966年 | 64篇 |
1965年 | 68篇 |
排序方式: 共有10000条查询结果,搜索用时 546 毫秒
921.
Martin Porubský Dr. Kristýna Vychodilová Dr. David Milićević Dr. Miloš Buděšinský Jarmila Stanková Dr. Petr Džubák Dr. Marián Hajdúch Prof. Jan Hlaváč 《ChemistryOpen》2021,10(11):1104-1110
The combination of cytotoxic amino-BODIPY dye and 2-phenyl-3-hydroxy-4(1H)-quinolinone (3-HQ) derivatives into one molecule gave rise to selective activity against lymphoblastic or myeloid leukemia and the simultaneous disappearance of the cytotoxicity against normal cells. Both species′ conjugation can be realized via a disulfide linker cleavable in the presence of glutathione characteristic for cancer cells. The cleavage liberating the free amino-BODIPY dye and 3-HQ derivative can be monitored by ratiometric fluorescence or by the OFF-ON effect of the amino-BODIPY dye. A similar cytotoxic activity is observed when the amino-BODIPY dye and 3-HQ derivative are connected through a non-cleavable maleimide linker. The work reports the synthesis of several conjugates, the study of their cleavage inside cells, and cytotoxic screening. 相似文献
922.
Ander Chapartegui-Arias Anna Raysyan Dr. Ana M. Belenguer Dr. Carsten Jaeger Teodor Tchipilov Carsten Prinz Dr. Carlos Abad Dr. Sebastian Beyer Dr. Rudolf J. Schneider Dr. Franziska Emmerling 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(36):9414-9421
Zeolitic imidazolate framework (ZIF) hybrid fluorescent nanoparticles and ZIF antibody conjugates have been synthesized, characterized, and employed in lateral-flow immunoassay (LFIA). The bright fluorescence of the conjugates and the possibility to tailor their mobility gives a huge potential for diagnostic assays. An enzyme-linked immunosorbent assay (ELISA) with horseradish peroxidase (HRP) as label, proved the integrity, stability, and dispersibility of the antibody conjugates, LC-MS/MS provided evidence that a covalent link was established between these metal-organic frameworks and lysine residues in IgG antibodies. 相似文献
923.
Explaining the emergence of life is perhaps central and the most challenging question in modern science. Within this area of research, the emergence and evolution of the genetic code is supposed to be a critical transition in the evolution of modern organisms. The canonical genetic code is one of the most dominant aspects of life on this planet, and thus studying its origin is critical to understanding the evolution of life, including life’s emergence. In this sense it is possible to view the ribosome as a digital-to-analogue information converter. Why the translation apparatus evolved, is one of the enduring mysteries of molecular biology. Assuming the hypothesis that during the emergence of life evolution had to first involve autocatalytic systems, which only subsequently acquired the capacity of genetic heredity, in the present article we discuss some aspects and causes of the possible emergence of digital, discrete information arising from analogue information realized in the intra- and inter-molecular interactions throughout molecular evolution. How such reverse translation was achieved at a molecular level is still unclear. The results of such debates and investigations might shift current biological paradigms and might also have a momentous significance for modern philosophy in understanding our place in the universe. 相似文献
924.
925.
Harabor Novac Adrian Harabor Ana Rotaru Petre 《Plasma Chemistry and Plasma Processing》2017,37(1):305-323
Plasma Chemistry and Plasma Processing - A study is made on optical emission spectrum modification during X-ray exposure, in the case of a high-pressure mercury discharge lamp operated at several... 相似文献
926.
da Silva Jussara Vieira Madurro Ana Graci Brito Madurro João Marcos 《Journal of Solid State Electrochemistry》2017,21(7):2129-2139
Journal of Solid State Electrochemistry - This paper reports a new platform for oligonucleotide hybridization, prepared by electropolymerization of 3-hydroxyphenylacetic acid onto gold electrode... 相似文献
927.
The generation of highly organized amyloid fibrils is associated with a wide range of conformational pathologies, including primarily neurodegenerative diseases. Such disorders are characterized by misfolded proteins that lose their normal physiological roles and acquire toxicity. Recent findings suggest that proteostasis network impairment may be one of the causes leading to the accumulation and spread of amyloids. These observations are certainly contributing to a new focus in anti‐amyloid drug design, whose efforts are so far being centered on single‐target approaches aimed at inhibiting amyloid aggregation. Chaperones, known to maintain proteostasis, hence represent interesting targets for the development of novel therapeutics owing to their potential protective role against protein misfolding diseases. In this minireview, research on nanoparticles that can either emulate or help molecular chaperones in recognizing and/or correcting protein misfolding is discussed. The nascent concept of “nanochaperone” may indeed set future directions towards the development of cost‐effective, disease‐modifying drugs to treat several currently fatal disorders. 相似文献
928.
The study of D(?)-ribose complexing with calcium in aqueous solutions less than 1.64 × 10?1M by potentiometric measurements with a calcium selective electrode afforded the value of K1 = 1.70 liters × mole?1 (SD = 1.05 × 10?3). Numerical analysis indicated that complex species with 1:1 and 1:2 calcium to D(-)-ribose ratios are present simultaneously: k1 = 1.13 liters × mole?1 and K2 = 8.47 liters × mole?1 (SD = 0.95 × 10?3).In methanolic medium 1.24 × 10?2M with regard to calcium chloride both stoichiometric proportions were evidenced. A large error accompanying the stability constant K1 = 28 kg × mole?1 (RSD = 82%) renders unreasonable the K2 value obtained from the product K1 × K2 = 96.5 kg2 × mole?2.The results are discussed with respect to the data published for more concentrated (1.27 M) aqueous solutions obtained on the basis of 1H-NMR spectroscopic investigations. 相似文献
929.
A procedure is proposed enabling corrections to be made of the measured admittance components for the resistance uncompensated by the positive feedback, and so to determine the charge-transfer rate constants in dilute solutions of supporting electrolytes. The procedure was checked for the Zn2+/Zn(Hg) redox system in NaNO3 up to 10?2M. A large increase of the measured rate constants with the dilution of the supporting electrolyte was found, obeying the Frumkin double-layer correction. 相似文献
930.