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Peptidic aminopeptidase inhibitors, bestatin, phebestin and probestin have been prepared by stereo- and regiocontrolled reactions from a common α,β-epoxy ester precursor. 相似文献
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Peptidosulfonamides are an emerging group of peptidomimetics with a variety of applications in medicinal chemistry. We present a novel approach to the synthesis of peptidosulfonamides, and apply it to a series of new potential inhibitors of the bacterial peptidoglycan biosynthesis enzymes MurD and MurE. The synthesis was conducted via N-phthalimido β-aminoethanesulfonyl chlorides, which are new building blocks for the synthesis of peptidosulfonamides. In the most crucial step, sulfonic acids or their sodium salts were converted into the corresponding sulfonyl chlorides using an excess of either SOCl2 or SOCl2/DMF, and then coupled to the C-protected amino acid. None of the compounds significantly inhibited MurD, however, some inhibited MurE; one had an IC50 below 200 μM, which constitutes a promising starting point for further development. Molecular modelling simulations were performed on two analogues to investigate the absence of inhibitory activity of the sulfonamide compounds on MurD. 相似文献
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Applied Biochemistry and Biotechnology - 相似文献
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Summary There has been a rapid growth of interest in techniques for site-directed drug design, fuelled by the increasing availability of structural models of proteins of therapeutic importance, and by studies reported in the literature showing that potent chemical leads can be obtained by these techniques. Structure generation programs offer the prospect of discovering highly original lead structures from novel chemical families. Due to the fact that this technique is more-or-less still in its infancy, there are no case studies available that demonstrate the use of structure generation programs for site-directed drug design. Such programs were first proposed in 1986, and became commercially available in early 1992. They have shown their ability to reproduce, or suggest reasonable alternatives for, ligands in well-defined binding sites. This brief review will discuss the recent advances that have been made in the field of site-directed structure generation. 相似文献
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Many natural products contain carbohydrate moieties that contribute to their biological activity. Manipulation of the carbohydrate domain of natural products through multiple glycosylations to identify new derivatives with novel biological activities has been a difficult and impractical process. We report a practical one‐pot enzymatic approach with regeneration of cosubstrates to synthesize analogues of vancomycin that contain an N‐alkyl glucosamine, which exhibited marked improvement in antibiotic activity against a vancomycin‐resistant strain of Enterococcus. 相似文献
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《Tetrahedron letters》2003,44(40):7411-7415
The first total synthesis of two E type I phytoprostanes from furan, azelaic acid monomethyl ester and rac-1,2-epoxybutane is described. The key features of our synthetic strategy encompass an enzymatic kinetic resolution of a hydroxycyclopentenone, a Co-salen hydrolytic kinetic resolution of a terminal epoxide and a tandem conjugate addition/diastereoselective protonation sequence to construct the protected phytoprostanes. Mild cleavage of the silyl protective groups followed by enzymatic ester hydrolysis afforded the free E-type phytoprostanes. 相似文献
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Isosteric derivatives and analogues of the 7-keto-8-aminopelargonic acid (KAPA), 7,8-diaminopelargonic acid (DAPA) and desthiobiotin (DTB) vitamer intermediates involved in the biosynthetic pathway of biotin were prepared and evaluated as potential herbicides. The most active compound was desmethyl-KAPA which displayed a GR50 (concentration of the active compound that causes a 50% growth inhibition) value of 8 ppm, where values <50 ppm are considered herbicidal. Other KAPA analogs where the terminal Me group was replaced by bulkier substituents such as Et, i-Pr and HOCH2 showed moderate activity. 相似文献
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用核黄素 蛋氨酸光照法和黄嘌呤氧化酶 细胞色素C还原法证实,在1.0×10-6~1.0×10-5mol/L范围内四羧基锰酞菁(TcPcMn)表现出良好的清除超氧阴离子自由基(O—·2)的活性;用黄嘌呤氧化酶 NBT还原法测算出的TcPcMn清除O—·2的二级反应速率常数为7.77×105mol-1·L·s-1,表明TcPcMn作为超氧化物歧化酶(SOD)模拟酶能很好的抑制O—·2的还原性.TcPcMn既能催化H2O2与4 氨基安替比林和酚的显色反应,也能催化邻苯二胺的聚合,表明TcPcMn具有过氧化物酶(POD)活性.用邻苯三酚自氧法得出,TcPcMn将O—·2的氧化性转化成了POD和H2O2的氧化性.因此只要牺牲一定的POD底物,TcPcMn就可以清除掉因歧化O—·2而产生的H2O2,继而能避免因发生Fenton反应而产生氧化性高于O—·2的羟自由基,从而彻底消除O—·2的氧化性,与SOD相比,这是TcPcMn的一个优势. 相似文献