全文获取类型
收费全文 | 1208篇 |
免费 | 81篇 |
国内免费 | 36篇 |
专业分类
电工技术 | 8篇 |
综合类 | 67篇 |
化学工业 | 267篇 |
金属工艺 | 26篇 |
机械仪表 | 75篇 |
建筑科学 | 7篇 |
矿业工程 | 2篇 |
能源动力 | 11篇 |
轻工业 | 250篇 |
石油天然气 | 8篇 |
无线电 | 130篇 |
一般工业技术 | 148篇 |
冶金工业 | 5篇 |
原子能技术 | 2篇 |
自动化技术 | 319篇 |
出版年
2024年 | 4篇 |
2023年 | 22篇 |
2022年 | 30篇 |
2021年 | 56篇 |
2020年 | 33篇 |
2019年 | 25篇 |
2018年 | 29篇 |
2017年 | 44篇 |
2016年 | 46篇 |
2015年 | 48篇 |
2014年 | 67篇 |
2013年 | 93篇 |
2012年 | 75篇 |
2011年 | 121篇 |
2010年 | 72篇 |
2009年 | 91篇 |
2008年 | 98篇 |
2007年 | 92篇 |
2006年 | 69篇 |
2005年 | 44篇 |
2004年 | 40篇 |
2003年 | 19篇 |
2002年 | 25篇 |
2001年 | 16篇 |
2000年 | 8篇 |
1999年 | 10篇 |
1998年 | 9篇 |
1997年 | 7篇 |
1996年 | 6篇 |
1995年 | 10篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有1325条查询结果,搜索用时 312 毫秒
61.
Three methods are proposed for determining the diffusion coefficient D for several substances in vivo. The results are discussed along with the prospects for using chemical biosensors for examining the variations in D produced by external physical factors (vortex magnetic fields). 相似文献
62.
63.
Optical biosensors provide a platform for qualitatively and quantitatively analyzing various biomolecular interactions. In addition to advantages such as label-free and high-throughput detection, these devices are also capable of measuring real-time binding curves in response to changes in optical properties of biomolecules. These kinetic data may be fitted to models to extract binding affinities such as association rates, dissociation rates, and equilibrium dissociation constants. In these biosensors, one of the binding pair is usually immobilized on a solid substrate for capturing the other. Due to the nature of these surface-based methods, mass transport effects and immobilization heterogeneity may cause problems when fitting the kinetic curves with the simple one-to-one Langmuir model. Here, real-time binding curves of various antibody–antigen reactions were obtained using an ellipsometry-based biosensor, and the results were fitted to the simple one-to-one model as well as a more sophisticated approach. The results show that the one-to-two model fitted much better to the curves than the one-to-one model. The two-site model may be explained by assuming two immobilization configurations on the surface. In summary, in fitting real-time curves obtained from optical biosensors, more sophisticated models are usually required to take surface-related issues, such as immobilization heterogeneity, and mass transport effects within targets, into account. 相似文献
64.
65.
光纤表面等离子体共振(SPR)传感器是目前应用在环境介质检测和生物大分子检测等方面的新型、高精度传感器。首先,以表面等离子体共振传感理论为基础,对系统检测结果进行数据处理,得出采用均值估计的线性模型。在不同时刻与相同环境介质下,检测某一溶液的十组光谱数据并进行均值估计,从而得到有效的共振波长。其次,利用小波分析方法进行信号处理,校正了噪声产生的漂移,对光谱信号压缩处理,以提高检测精度。再通过Matlab进行模拟仿真优化传感系统性能。并对不同折射率溶液如蒸馏水、酒精等进行检测,得到了良好的光谱响应曲线,证明了在检测范围内折射率和共振波长之间具有良好的线性关系。 相似文献
66.
T. M. Korves Y. M. Piceno L. M. Tom T. Z. DeSantis B. W. Jones G. L. Andersen G. M. Hwang 《Indoor air》2013,23(1):50-61
Practical Implications
A biosensor that could be deployed in commercial aircraft would be required to function at an extremely low false alarm rate, making an understanding of microbial background important. This study reveals a diverse bacterial background present on aircraft, including bacteria closely related to pathogens of public health concern. Furthermore, this aircraft background is different from outdoor air, suggesting different probes may be needed to detect airborne contaminants to achieve minimal false alarm rates. This study also indicates that aircraft HEPA filters could be used with other molecular techniques to further characterize background bacteria and in investigations in the wake of a disease outbreak.67.
The aim of this work is the integration of an improved graphite–epoxy composite electrode modified with the acetylcholinesterase enzyme as a detector into a green tape ceramic microfluidic device for the online amperometric determination of pesticides. First, the operational conditions of the microfluidic system were optimized for the enzymatic substrate determination of acetylthiocholine. Good results were achieved for acetylthiocholine determination, obtaining a low detection limit and optimal sensitivity. The analytical performance of the microanalyzer was evaluated with organophosphorus and carbamate pesticides across a wide concentration range. Pesticides were determined indirectly measuring the enzymatic inhibition effect that they caused. The analysis was based on stopped-flow methodology with a three-step strategy: enzymatic substrate measurement, enzymatic inhibition by pesticide contact with the biosensor, and enzymatic substrate measurement after the inhibition process. The pesticide concentrations were determined by the percentage of inhibition produced. The microanalyzer was used for the analysis of spiked irrigation water samples using this indirect method. The low-temperature co-fired ceramic/epoxy–graphite–acetylcholinesterase microfluidic system showed low limits of detection and adequate sensitivity. The recoveries of the spiked water samples were approximately 100% with relative standard deviation values lower than 5% for three replicate measurements. All results obtained are indicative of a convenient, rapid, sensitive, and economic method for the determination of pesticides in environmental samples. 相似文献
68.
石墨烯量子点具有许多吸引人的优点,如低细胞毒性、溶解能力强、稳定的光致发光、良好的生物相容性、高比表面积、电子高迁移率和可调节带隙等,因此,适用于构建传感系统和生物成像。根据近几年来,基于石墨烯量子点性质构建的光学生物传感器和电化学生物传感器以及石墨烯量子点在生物成像技术中的应用进行了综述。 相似文献
69.
70.