首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   170篇
  免费   10篇
化学   131篇
晶体学   2篇
数学   11篇
物理学   36篇
  2024年   2篇
  2023年   1篇
  2022年   7篇
  2021年   4篇
  2020年   4篇
  2019年   8篇
  2018年   5篇
  2017年   6篇
  2016年   10篇
  2015年   8篇
  2014年   11篇
  2013年   14篇
  2012年   15篇
  2011年   14篇
  2010年   6篇
  2009年   5篇
  2008年   12篇
  2007年   8篇
  2006年   2篇
  2005年   3篇
  2004年   6篇
  2003年   4篇
  2002年   2篇
  2001年   1篇
  2000年   6篇
  1998年   3篇
  1996年   2篇
  1994年   1篇
  1993年   2篇
  1992年   2篇
  1989年   1篇
  1988年   1篇
  1987年   2篇
  1986年   2篇
排序方式: 共有180条查询结果,搜索用时 15 毫秒
61.
Studies were carried out to the find out the efficacy of the ultrasonic irradiation as a pre-treatment step for the treatment of one of the polluting industrial effluents, the distillery spentwash. Experiments were carried out on the fresh and stored effluent samples. The effect of the ultrasound exposure on the biodegradability of the effluent was monitored by carrying out its subsequent aerobic oxidation. A comparison has been made between the efficacies of the pre-treated samples with the untreated samples. The results indicate that the ultrasound seems to increase the attractiveness of the conventional aerobic oxidation process by increasing their initial rates of degradation.  相似文献   
62.
This paper proposes optimum ramp accelerated life test (ALT) of m identical repairable systems using non-homogeneous power law process (PLP) under failure truncated case. An ALT with linearly increasing stress is a ramp test. In particular, a ramp test with two different linearly increasing stresses is a simple ramp test. The optimum ramp test with different stress rates is formulated by determining the proportions of test systems allocated to each stress rate using D-optimality criterion. D-optimality criterion minimizes the reciprocal of the determinant of the Fisher information matrix of the model parameters. The method developed is illustrated using two stress rates and three stress rates. It has been found that it takes much longer to obtain same estimated expected no. of failures at baseline condition than at stress levels.  相似文献   
63.
Pyridine-modified COF-10 exhibits enhanced stability in humid air relative to un-modified COF-10. Solid state NMR and computational studies were used to probe the nature of pyridine interactions with the framework. We propose two models for pyridine-framework interactions with different stabilities.  相似文献   
64.
We synthesized an imine-linked, benzimidazole-based chemosensor that can be used for chromogenic recognition of Mg2+ and fluorescent recognition of Cr3+. The chemosensor shows sensitive, selective, and ratiometric recognition of Cr3+ through concurrent quenching at one wavelength and enhancement of fluorescence intensity at another wavelength. It can also be used to detect Mg2+ via UV–vis absorption spectroscopy. DFT calculations support these phenomena. The sensor can be used to strain microbe cells without breakage.  相似文献   
65.
A benzimidazole-based imine linked receptor was synthesized for fluorescent recognition of Cu2+ in a CH3CN/H2O (8:2, v/v) solvent system. The receptor offers an opportunity for the selective estimation of Cu2+ in the presence of another metal ion at equimolar concentration. The Cu2+ complex with the receptor acted as a sensor for a phosphate anion, and the phosphate recognition event restored the fluorescence intensity of the receptor.  相似文献   
66.
The transformation of high-dimensional bioactivity spaces into activity landscape representations is as of yet an unsolved problem in computational medicinal chemistry. High-dimensional activity spaces result from the experimental evaluation of compound sets on large numbers of targets. We introduce a first concept to represent and navigate high-dimensional activity landscapes that is based on a data structure termed ligand-target differentiation (LTD) map. This approach is designed to reduce the complexity of high-dimensional bioactivity spaces and enable the identification and further analysis of compound subsets with interesting activity and structural relationships. Its utility has been demonstrated using a set of more than 1400 inhibitors with exact activity measurements for varying numbers of 172 kinases.  相似文献   
67.
Using state-of-the-art density functional theoretical calculations, we have modelled a facetted CdS nanotube (NT) catalyst for photocatalytic water splitting. The overall photocatalytic activity of the CdS photocatalyst has been predicted based on the electronic structures, band edge alignment, and overpotential calculations. For comparisons, we have also investigated the water splitting process over bulk CdS. The band edge alignment along with the oxygen evolution reaction/hydrogen evolution reaction (OER/HER) mechanism studies help us find out the effective overpotential for the overall water splitting on these surfaces. Our study shows that the CdS NT has a highly stabilized valence band edge compared to that of bulk CdS owing to strong p–d mixing. The highly stabilized valence band edge is important for the hole-transfer process and reduces the risk of electron-hole recombination. CdS nanotube requires less overpotential for water oxidation reaction than the bulk CdS. Our findings suggest that the efficiency of the water oxidation/reduction process further improves in CdS as we reduce its dimensionality, that is going from bulk CdS to one-dimensional nanotube. Furthermore, the stabilized valence band edge of CdS nanotube also improves the photostability of CdS, which is a problem for bulk CdS.  相似文献   
68.
In this research work, both qualitative and quantitative measurement of biospeckle activity of three Indian fruits namely apple, pear and tomato have been carried out using Generalized Difference and Parameterized Fujii methods. Different activity area of the fruits can be easily visualized through the spectral maps. The variation of activity level of the fruits during shelf life storage has been studied through activity graphs. Comparative studies of activities of all the fruits are also presented and relatively high activity was found in apple compared to pear and tomato.  相似文献   
69.
Analytical and numerical study of the stability of sheet electron beam in periodically cusped magnetic field (PCM) is made. The beam has been considered as having diffused density profile. The conditions for beam focusing are discussed.  相似文献   
70.
The aberrant expression of endocytic epidermal growth factor receptors (EGFRs) in cancer cells has emerged as a key target for therapeutic intervention. Here, we describe for the first time a state-of-the-art design for a heparan sulfate (HS) oligosaccharide-based nanovehicle to target EGFR-overexpressed cancer cells in cellular heterogeneity. An ELISA plate IC50 inhibition assay and surface plasma resonance (SPR) binding assay of structurally well-defined HS oligosaccharides showed that 6-O-sulfation (6-O-S) and 6-O-phosphorylation (6-O-P) of HS tetrasaccharides significantly enhanced EGFR cognate growth factor binding. The conjugation of these HS ligands to multivalent fluorescent gold nanoparticles (AuNPs) enabled the specific and efficient targeting of EGFR-overexpressed cancer cells. In addition, this heparinoid-nanovehicle exhibited selective homing to NPs in cancer cells in three-dimensional (3D) coculture spheroids, thus providing a novel target for cancer therapy and diagnostics in the tumor microenvironment (TME).

Heparan sulfate oligosaccharide based nanovehicle greatly enhance the selective targeting of cancer cells in tumor microenvironment.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号