全文获取类型
收费全文 | 958篇 |
免费 | 60篇 |
专业分类
电工技术 | 9篇 |
化学工业 | 260篇 |
金属工艺 | 15篇 |
机械仪表 | 15篇 |
建筑科学 | 16篇 |
能源动力 | 40篇 |
轻工业 | 198篇 |
水利工程 | 3篇 |
石油天然气 | 3篇 |
无线电 | 83篇 |
一般工业技术 | 148篇 |
冶金工业 | 75篇 |
原子能技术 | 3篇 |
自动化技术 | 150篇 |
出版年
2023年 | 9篇 |
2022年 | 37篇 |
2021年 | 32篇 |
2020年 | 21篇 |
2019年 | 37篇 |
2018年 | 32篇 |
2017年 | 34篇 |
2016年 | 35篇 |
2015年 | 35篇 |
2014年 | 34篇 |
2013年 | 69篇 |
2012年 | 56篇 |
2011年 | 75篇 |
2010年 | 46篇 |
2009年 | 57篇 |
2008年 | 60篇 |
2007年 | 30篇 |
2006年 | 46篇 |
2005年 | 37篇 |
2004年 | 36篇 |
2003年 | 27篇 |
2002年 | 21篇 |
2001年 | 18篇 |
2000年 | 9篇 |
1999年 | 11篇 |
1998年 | 23篇 |
1997年 | 14篇 |
1996年 | 13篇 |
1995年 | 11篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1989年 | 9篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有1018条查询结果,搜索用时 15 毫秒
91.
Maria José Ocio Pablo Salvador Fernandez Miguel Rodrigo Paula Periago A. Martinez 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1997,205(4):325-328
A time temperature integrator (TTI) was developed by immobilizing Bacillus stearothermophilus spores in a cylindrical particle consisting of an alginate-starch-mushroom purée. The particle showed homogeneous spore distribution,
and when heated over a temperature range of 121 – 130° C negligible spore leakage was observed after the thermal process.
The experimental data on spore survivor levels obtained for each temperature-time combination were compared with theoretical
predictions using a mathematical model. The results showed a good correlation between the experimental and theoretical data.
All these results provide evidence that this artificial particle could be a very reliable TTI for monitoring the thermal impact
on micro-organisms during validating sterilization processes in continuous aseptic systems.
Received: 25 February 1997 相似文献
92.
Teresa Lana Villarreal Peter Bogdanoff Pedro Salvador N.Nicols Alonso-Vante 《Solar Energy Materials & Solar Cells》2004,83(4):347-362
Surface mesoscopic titanium dioxide (P25) films deposited onto conducting glass plates (SnO2:F) were modified by colloidal RuxSey nanoparticles (2 nm diameter). A decrease of the photocurrent was found upon modification of TiO2 films. However, interfacial electron transfer kinetics to oxygen was favored. The increase of the catalyst surface concentration onto TiO2, shifts the onset of the photocurrent under UV-illumination, to 0.6 V/RHE in presence of oxygen dissolved in the electrolyte. Concomitant to this, the cathodic current becomes important and shifts to more positive potentials. This phenomenon allows the system to work catalytically under open circuit conditions. On non-modified TiO2, the application of a 0.3 V/RHE potential leads to an enhancement of the photooxidation of formic acid. Photocurrent images revealed a non-homogeneous distribution of the catalyst on the titanium dioxide films. 相似文献
93.
94.
A study was made of the interfacial properties of Poly(pyrrole) (PP) deposited electrochemically onto single crystal p-Si
surfaces. The interfacial properties are dependent upon the counterions. The formation of “Quasi-Ohmic” and “non-Ohmic” contacts,
respectively, of PP(C1O4) and PP films doped with other counterions (BF4 and para-toluene sulfonate) with p-Si, are explained in-terms of the conductivity of these films and the flat band potential,V
fb, of PP relative to that ofp-Si. The PP film seems to passivate or block intrinsic surface states present on thep-Si surface. The differences in the impedance behavior of para-toluene sulfonate doped and C1O4 doped PP are compared. 相似文献
95.
96.
Giuseppe Fregapane Vera Lavelli Sonia Len Jasenka Kapuralin M. Desamparados Salvador 《European Journal of Lipid Science and Technology》2006,108(2):134-142
The effect of filtration and dehydration on the stability and quality of virgin olive oil during storage at room temperature (25 °C) and under accelerated conditions (40 °C) was studied. Different types of monovarietal olive oil, namely unfiltered (UF), filtered (F) and filtered‐dehydrated (FD), were obtained from Arbequina, Colombaia, Cornicabra, Picual and Taggiasca cultivars. Results showed that filtration and dehydration decreased the rate of hydrolysis of the triacylglycerol matrix, especially at the higher temperature and in oils with a higher initial free acidity (e.g. free acidity of 0.82% and 0.63% in UF and FD Colombaia samples, respectively, after 8 months of storage), and delayed the appearance of rancid defects (e.g. UF and FD Arbequina samples lost extra‐virgin grade after 10 and 12 months of storage, respectively). The formation of simple phenols due to the hydrolysis rate of their secoiridoid derivatives was also greater in unfiltered olive oils (e.g. 174 μmol/kg and 137 μmol/kg in UF and FD Picual samples, respectively, after 8 months of storage). Thus, filtration and especially dehydration could help to prolong the shelf life of high‐quality and less stable olive oils like those obtained from the Arbequina and Colombaia varieties. 相似文献
97.
Garmendia L. Yager R.R. Trillas E. Salvador A. 《Fuzzy Systems, IEEE Transactions on》2006,14(4):568-572
The concept of measure of specificity of fuzzy sets is extended in this paper to measure of specificity under the knowledge of T-indistinguishabilities. Four axioms of measure of specificity under T-indistinguishabilities are given. An algorithm to compute the inference independent set /spl Tfr/ from a fuzzy set and a T-indistinguishability is used to measure the specificity of fuzzy sets under T-indistinguishabilities satisfying the axioms. 相似文献
98.
99.
100.
Weak input signals are routinely processed by molecular-scaled biological networks composed of non-identical units that operate correctly in a noisy environment. In order to show that artificial nanostructures can mimic this behavior, we explore theoretically noise-assisted signal processing in arrays of metallic nanoparticles functionalized with organic ligands that act as tunneling junctions connecting the nanoparticle to the external electrodes. The electronic transfer through the nanostructure is based on the Coulomb blockade and tunneling effects. Because of the fabrication uncertainties, these nanostructures are expected to show a high variability in their physical characteristics and a diversity-induced static noise should be considered together with the dynamic noise caused by thermal fluctuations. This static noise originates from the hardware variability and produces fluctuations in the threshold potential of the individual nanoparticles arranged in a parallel array. The correlation between different input (potential) and output (current) signals in the array is analyzed as a function of temperature, applied voltage, and the variability in the electrical properties of the nanostructures. Extensive kinetic Monte Carlo simulations with nanostructures whose basic properties have been demonstrated experimentally show that variability can enhance the correlation, even for the case of weak signals and high variability, provided that the signal is processed by a sufficiently high number of nanostructures. Moderate redundancy permits us not only to minimize the adverse effects of the hardware variability but also to take advantage of the nanoparticles' threshold fluctuations to increase the detection range at low temperatures. This conclusion holds for the average behavior of a moderately large statistical ensemble of non-identical nanostructures processing different types of input signals and suggests that variability could be beneficial for signal processing. We demonstrate also that circuits composed of coupled non-identical nanoparticles can act as elementary nano-oscillators that show synchronization properties for sub-threshold stimuli. The results obtained should be of conceptual interest for the design of reliable signal processing schemes with non-identical nanostructures. 相似文献