收费全文 | 309篇 |
免费 | 7篇 |
国内免费 | 1篇 |
化学 | 230篇 |
晶体学 | 6篇 |
力学 | 9篇 |
数学 | 13篇 |
物理学 | 59篇 |
2023年 | 1篇 |
2022年 | 10篇 |
2021年 | 14篇 |
2020年 | 8篇 |
2019年 | 5篇 |
2018年 | 15篇 |
2017年 | 9篇 |
2016年 | 11篇 |
2015年 | 10篇 |
2014年 | 19篇 |
2013年 | 28篇 |
2012年 | 25篇 |
2011年 | 26篇 |
2010年 | 16篇 |
2009年 | 12篇 |
2008年 | 16篇 |
2007年 | 9篇 |
2006年 | 8篇 |
2005年 | 11篇 |
2004年 | 5篇 |
2003年 | 6篇 |
2002年 | 10篇 |
2001年 | 3篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1984年 | 6篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
A mathematical model of electrostatic interaction with reaction-generated pH change on the kinetics of immobilized enzyme is discussed. The model involves the coupled system of non-linear reaction–diffusion equations of substrate and hydrogen ion. The non-linear term in this model is related to the Michaelis–Menten reaction of the substrate and non-Michaelis–Menten kinetics of hydrogen ion. The approximate analytical expression of concentration of substrate and hydrogen ion has been derived by solving the non-linear reactions using Taylor’s series method. Reaction rate and effectiveness factor are also reported. A comparison between the analytical approximation and numerical solution is also presented. The effects of external mass transfer coefficient and the electrostatic potential on the overall reaction rate were also discussed.
相似文献We are describing immunochromatographic test strips with smart phone-based fluorescence readout. They are intended for use in the detection of the foodborne bacterial pathogens Salmonella spp. and Escherichia coli O157. Silica nanoparticles (SiNPs) were doped with FITC and Ru(bpy), conjugated to the respective antibodies, and then used in a conventional lateral flow immunoassay (LFIA). Fluorescence was recorded by inserting the nitrocellulose strip into a smart phone-based fluorimeter consisting of a light weight (40 g) optical module containing an LED light source, a fluorescence filter set and a lens attached to the integrated camera of the cell phone in order to acquire high-resolution fluorescence images. The images were analysed by exploiting the quick image processing application of the cell phone and enable the detection of pathogens within few minutes. This LFIA is capable of detecting pathogens in concentrations as low as 105 cfu mL−1 directly from test samples without pre-enrichment. The detection is one order of magnitude better compared to gold nanoparticle-based LFIAs under similar condition. The successful combination of fluorescent nanoparticle-based pathogen detection by LFIAs with a smart phone-based detection platform has resulted in a portable device with improved diagnosis features and having potential application in diagnostics and environmental monitoring.
相似文献