全文获取类型
收费全文 | 231篇 |
免费 | 11篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 36篇 |
金属工艺 | 1篇 |
机械仪表 | 9篇 |
建筑科学 | 5篇 |
能源动力 | 30篇 |
轻工业 | 1篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 32篇 |
一般工业技术 | 48篇 |
冶金工业 | 4篇 |
自动化技术 | 73篇 |
出版年
2023年 | 10篇 |
2022年 | 14篇 |
2021年 | 26篇 |
2020年 | 11篇 |
2019年 | 20篇 |
2018年 | 13篇 |
2017年 | 13篇 |
2016年 | 14篇 |
2015年 | 7篇 |
2014年 | 13篇 |
2013年 | 17篇 |
2012年 | 12篇 |
2011年 | 18篇 |
2010年 | 19篇 |
2009年 | 11篇 |
2008年 | 3篇 |
2007年 | 9篇 |
2006年 | 4篇 |
2005年 | 1篇 |
2004年 | 2篇 |
2002年 | 1篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
排序方式: 共有244条查询结果,搜索用时 15 毫秒
91.
A sequential application of UV as a primary disinfectant with and without H2O2 addition followed by free chlorine as secondary, residual disinfectant was performed to evaluate the synergistic inactivation of selected indicator microorganisms, MS-2 bacteriophage and Bacillus subtilis spores. No synergism was observed when the UV irradiation treatment was followed by free chlorine, i.e., the overall level of inactivation was the same as the sum of the inactivation levels achieved by each disinfection step. With the addition of H2O2 in the primary UV disinfection step, however, enhanced microbial inactivation was observed. The synergism was observed in two folds manners: (1) additional inactivation achieved by hydroxyl radicals generated from the photolysis of H2O2 in the primary UV disinfection step, and (2) damage to microorganisms in the primary step which facilitated the subsequent chlorine inactivation. Addition of H2O2 in the primary disinfection step was also found to be beneficial for the degradation of selected model organic pollutants including bisphenol-A (endocrine disruptor), geosmin (taste and odor causing compound) and 2,4-D (herbicide). The results suggest that the efficiency of UV/free chlorine sequential disinfection processes, which are widely employed in drinking water treatment, could be significantly enhanced by adding H2O2 in the primary step and hence converting the UV process to an advanced oxidation process. 相似文献
92.
Javali K. Madhukesh Ravikumar S. Varun Kumar Ramanahalli J. Punith Gowda Ballajja C. Prasannakumara Sabir A. Shehzad 《亚洲传热研究》2022,51(4):3082-3098
The Riga surface is composed of an electromagnetic actuator that comprises a span-wise associated array of discontinuous electrodes and an everlasting magnet mounted over a planer surface. The electro-magneto-hydrodynamic has an attractive role in thermal reactors, fluidics network flow, liquid chromatography, and micro coolers. Inspired by these applications, a laminar, two-dimensional nanofluid flow with uniform heat sink-source, thermophoretic depositions of the particles, and the Newtonian heating effect are investigated. The equations that describe the fluid motion are reduced into a system of ordinary differential equations with the help of spatial similarity variables. Numeric solutions of ordinary differential equations are executed through the Runge–Kutta–Felhberg 45 order technique via a shooting scheme. The role of various nondimensional factors on physically interesting quantities is elaborated graphically. The velocity profile rises for modified Hartmann number and decreases for porosity parameter. Thermal enhancement is high in the common wall temperature condition comparative to the case of the Newtonian heating conditions. The concentration profile is enhanced with Schmidt number, but the reverse trend is observed for the thermophoretic parameter. The rate of mass transfer is increased with Schmidt number. 相似文献
93.
Silt particle laden flow through hydro turbine components causes erosion to the surface which comes in contact with it. Silt size, silt concentration, velocity of flow, properties of silt materials and operating hours of turbine play a vital role in damaging the turbine components. Efficiency of the turbine decreases with increase in erosive wear. The present study has been carried out to experimentally investigate the effect of silt size, silt concentration, jet velocity and operating time on performance of Turgo impulse turbine under actual flow conditions. It has been found that turbine efficiency loss strongly depends upon silt parameters. Existing test bed has shown erosion wear up to 1.8%, therefore resulting in the loss of power generation. Based on experimental data obtained for different parameters, correlations have been developed for the prediction of percentage efficiency loss of Turgo impulse turbine. 相似文献
94.
The paper presents design, development and testing of a resonant proximity DC current sensor to measure current in the range of 0-20 mA. The sensor is built using cantilever structure with piezoelectric excitation, sensing and closed loop electronics. The sensor measures the DC current by measuring the shift in resonance frequency of the cantilever beam. The proposed measurement system is novel, simple and accuracy is found to be 1.1% of full scale deflection. 相似文献
95.
Bipolar plates (BPs) are a major component of polymer electrolyte membrane fuel cells (PEMFCs). BPs play a multifunctional character within a PEMFC stack. It is one of the most costly and critical part of the fuel cell, and hence the development of efficient and cost-effective BPs is of much interest for the fabrication of next-generation PEMFCs in future. Owing to high electrical conductivity and chemical inertness, graphene is an ideal candidate to be utilized in BPs. This paper reviews recent advances in the area of graphene-based BPs for PEMFC applications. Various aspects including the momentous functions of BPs in the PEMFC, favorable features of graphene-based BPs, performance evaluation of various reported BPs with their advantages and disadvantages, challenges at commercial level products and future prospects of frontier research in this direction are extensively documented. 相似文献
96.
Vinay Kumar H.C. Swart O.M. Ntwaeaborwa Ravi Kumar S.P. Lochab Varun Mishra Nafa Singh 《Optical Materials》2009,32(1):164-168
A study of the thermoluminescence (TL) parameters has been performed on swift heavy ion exposed Bi3+ doped CaS nanophosphors prepared by the chemical co-precipitation method. All the samples have been exposed to 200 MeV Ag+15 ions in a fluence range of 1 × 1012–1 × 1013 ions/cm2. The prominent TL glow peak at 403 K (observed for the γ-irradiated sample) appeared at the same position in the 200 MeV Ag+15 ion beam irradiated samples, while the other peak at 466 K disappeared and the broad peak normally measured at 534 K split into two peaks at 535 K and 582 K for the Ag+15 ion beam irradiated samples. The effect of different Bi3+ concentration has been investigated and it was found that the maximum TL intensity was measured for the 0.08 mol% sample. The effect of different heating rates on the TL response has also been determined. The trapping parameters (i.e. activation energy, frequency factor, order of kinetic) of all the individual peaks of the glow curves have been analysed by using Chen’s formulae. The low fading and linear TL response in the range of 1 × 1012–1 × 1013 ions/cm2 will be helpful to explore the potential use of this material for heavy ion dosimetry. 相似文献
97.
Due to low heat transfer capability, the thermal efficiency of solar collectors is very low and various techniques are implemented to increase the performance of solar air heaters. There is a need for optimization of design and operating parameters for maximizing the thermal gain from the solar air heating systems. In this paper a stochastic iterative perturbation technique (SIPT) is implemented to obtain the optimized set of different system and operating parameters i.e. the number of glass cover plate, emissivity of the plate, mean plate temperature, rise in temperature, tilt angle and solar radiation intensity for different Reynolds number. The results obtained have also been compared with the results obtained from genetic algorithm and random search global optimization technique for smooth flat plate solar air heater. 相似文献
98.
The state of aggregation of compounds, especially drugs, in the cores of nanoparticles (NPs) formed by rapid precipitation is a significant unresolved issue. The state can control the dissolution kinetics from the NP, bioavailability, and chemical stability of the compound. A block-copolymer-directed rapid precipitation process is used to form ≈100 nm NPs comprising mixtures of hydrophobic species including fluorescent probe molecules. Fluorescence measurements are used to probe the state of aggregation and dynamics of rearrangement of pyrene (Py), Hostasol Yellow (HosY), and amphotericin B (AmpB) in NP cores. The Flory-Huggins theory of mixing is used to predict the miscibility or phase separation of the fluorophores from the host NP core material (polystyrene, cholesterol, or polycaprolactone). For Py, excimer fluorescence shows an initial microphase separation in the polystyrene core. Over time the Py redistributes more uniformly with a decrease in excimer and increase in monomer fluorescence. The Flory-Huggins theory predicts the miscibility. For HosY, the fluorescence quenching is not time-dependent, thus indicating stability of the microphase-separated fluorophores, which is consistent with the Flory-Huggins theory calculations. For the drug compound AmpB, the amphiphilic character of the molecule creates unusual "anti-Ostwald" ripening behavior in which the size distribution decreases and narrows over time, and the fluorescence demonstrates an increased ordering in the NP core over time--opposite to the behavior observed for Py. 相似文献
99.
Sandip Rooj Amit Das Varun Thakur R.N. Mahaling Anil K. Bhowmick Gert Heinrich 《Materials & Design》2010
A ‘green’ composite based on natural halloysite nanotubes (HNTs) and natural rubber (NR) was prepared by mechanical mixing. A silane coupling agent, bis (triethoxysilylpropyl)-tetrasulphide, was utilized to enhance the properties of these composites. It was observed that the reinforcing activity of HNTs was superior to commercial silica coupled with the same amount of silane coupling agent. Moreover the on-set thermal degradation decomposition temperature was improved by ∼64 °C with the addition of 10 parts HNTs per hundred of rubber. Transmission electron microscopic images confirmed the good dispersion of the HNTs in the rubber matrix, whereas X-ray diffraction studies showed a little change in interlayer spacing between the two silicate layers of HNTs. 相似文献
100.
Jelena Pozojevic Shela Marie Algodon Joseph Neos Cruz Joanne Trinh Norbert Brüggemann Joshua Laß Karen Grütz Susen Schaake Ronnie Tse Veronica Yumiceba Nathalie Kruse Kristin Schulz Varun K. A. Sreenivasan Raymond L. Rosales Roland Dominic G. Jamora Cid Czarina E. Diesta Jakob Matschke Markus Glatzel Philip Seibler Kristian Hndler Aleksandar Rakovic Henriette Kirchner Malte Spielmann Frank J. Kaiser Christine Klein Ana Westenberger 《International journal of molecular sciences》2022,23(4)