全文获取类型
收费全文 | 268篇 |
免费 | 47篇 |
国内免费 | 46篇 |
专业分类
化学 | 281篇 |
力学 | 3篇 |
综合类 | 1篇 |
数学 | 7篇 |
物理学 | 69篇 |
出版年
2023年 | 8篇 |
2022年 | 8篇 |
2021年 | 34篇 |
2020年 | 24篇 |
2019年 | 20篇 |
2018年 | 18篇 |
2017年 | 12篇 |
2016年 | 25篇 |
2015年 | 19篇 |
2014年 | 21篇 |
2013年 | 32篇 |
2012年 | 26篇 |
2011年 | 16篇 |
2010年 | 9篇 |
2009年 | 8篇 |
2008年 | 15篇 |
2007年 | 15篇 |
2006年 | 7篇 |
2005年 | 12篇 |
2004年 | 5篇 |
2003年 | 3篇 |
2002年 | 6篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有361条查询结果,搜索用时 15 毫秒
81.
Modulating the speciation of sulfur containing functional group could alter the subcellular localization of a series thiomorpholine incorporated coumarins. 相似文献
82.
Thumshirn G Hersel U Goodman SL Kessler H 《Chemistry (Weinheim an der Bergstrasse, Germany)》2003,9(12):2717-2725
The alpha v beta 3 integrin receptor plays an important role in human metastasis and tumor-induced angiogenesis. Targeting this receptor may provide information about the receptor status of the tumor and enable specific therapeutic planning. Solid-phase peptide synthesis of multimeric cyclo(-RGDfE-)-peptides is described, which offer the possibility of enhanced integrin targeting due to polyvalency effects. These peptides contain an aminooxy group for versatile chemoselective oxime ligation. Conjugation with para-trimethylstannylbenzaldehyde results in a precursor for radioiododestannylation, which would allow them to be used as potential tools for targeting and imaging alpha v beta 3-expressing tumor cells. The conjugates were obtained in good yield without the need of a protection strategy and under mild conditions. 相似文献
83.
84.
StudiesonHepatocyte┐TargetingMagneticResonanceImagingMacromolecularContrastMedia*FUYan-junandZHUORen-xi**(DepartmentofChemist... 相似文献
85.
Shao Ning WANG Ying Kun QIU Hui XU Yi Hui DENG Da Wei CHEN 《中国化学快报》2006,17(2):173-176
Mammalian hepatocytes (parenchymal cells) exclusively possess large number ofasialoglycoprotein receptors (ASGPr), which can recognize terminal D-galactose orN-acetylgalactosamine residues. Lactobionic acid 1, bearing a galactosyl group, isusually used as… 相似文献
86.
The -potential of copolymer particles of acrylic amide, acrylic acid, acrylic butyl ester, and styrene were measured in different electrolyte solutions. In an isotonic solution of sodium chloride, they vary with the content of acrylic acid between –36 mV and –49 mV. In the presence of 21-electrolytes, the -potential could be correlated with the logarithm of the electrolyte concentration. The 21-electrolytes predominantly determine the -potential of the particles not only in the solutions of these electrolytes, but also in mixed electrolyte solutions. In the presence of human serum, the electrophoretic mobility increases with increasing acrylic acid content of the polymer. 相似文献
87.
88.
A previous study has shown that retention of magnetic particles at a model airway surface requires prohibitively strong magnetic fields. As mucus viscoelasticity is the most significant factor contributing to clearance of magnetic particles from the airway surface, mucolytics are considered in this study to reduce mucus viscoelasticity and enable particle retention with moderate strength magnetic fields. The excised frog palate model was used to simulate the airway surface. Two mucolytics, N-acetylcysteine (NAC) and dextran sulfate (DS) were tested. NAC was found to enable retention at moderate field values (148 mT with a gradient of 10.2 T/m), whereas DS was found to be effective only for sufficiently large particle concentrations at the airway surface. The possible mechanisms for the observed behavior with different mucolytics are also discussed based on aggregate formation and the loading of cilia. 相似文献
89.
具有癌细胞靶向性的荧光纳米探针在生物分析、生物医学和临床诊断等领域有着重要的应用前景。 本文基于碳量子点的低毒性、低成本、环境友好、制备方法简单及高发光特性等优点,采用水热法合成了表面富含氨基的荧光碳量子点(CDs),进一步通过1-(3-二甲氨基丙基)-3-乙基碳二亚胺盐酸盐(EDC)缩合的方法,将叶酸(FA)分子中的羧基与其共价连接,从而得到叶酸共价修饰的碳量子点复合材料(FA-CDs)。 通过将该复合材料分别与海拉(Hela)和小鼠胚胎成纤维(NIH-3T3)细胞共培养,发现该复合材料能够特异性识别并标记癌细胞,且制备的该复合材料具有低毒性和高发光性等优点。 该工作对癌细胞的早期诊断具有重要意义。 相似文献
90.
Yanhui Sun Aiyan Zhan Shuang Zhou Xiao Kuang Hongyan Shen Hongzhuo Liu Youjun Xu 《中国化学快报》2019,30(7):1435-1439
A novel mitochdrial-targeting tetrapeptide, RF-2(D-Arg-Dmt-Arg-Phe-NH2) had been developed, which showed controlled toxicity and excellent protection against gentamicin-induced hair cell damage, and more importantly, exhibited superior guidance towards mitochondrion achieved by its modified nanoparticles. 相似文献