全文获取类型
收费全文 | 511篇 |
免费 | 22篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 122篇 |
金属工艺 | 17篇 |
机械仪表 | 34篇 |
建筑科学 | 17篇 |
矿业工程 | 4篇 |
能源动力 | 68篇 |
轻工业 | 59篇 |
水利工程 | 2篇 |
石油天然气 | 2篇 |
无线电 | 36篇 |
一般工业技术 | 87篇 |
冶金工业 | 26篇 |
原子能技术 | 12篇 |
自动化技术 | 47篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 13篇 |
2021年 | 18篇 |
2020年 | 14篇 |
2019年 | 15篇 |
2018年 | 23篇 |
2017年 | 24篇 |
2016年 | 20篇 |
2015年 | 11篇 |
2014年 | 16篇 |
2013年 | 40篇 |
2012年 | 31篇 |
2011年 | 31篇 |
2010年 | 50篇 |
2009年 | 39篇 |
2008年 | 29篇 |
2007年 | 27篇 |
2006年 | 26篇 |
2005年 | 15篇 |
2004年 | 6篇 |
2003年 | 16篇 |
2002年 | 9篇 |
2001年 | 11篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1984年 | 1篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 3篇 |
排序方式: 共有535条查询结果,搜索用时 15 毫秒
11.
The effect of replacing fat with oat bran on fatty acid composition and physicochemical properties of meatballs 总被引:1,自引:0,他引:1
Oat bran was used as a fat substitute in the production of meatballs. The effect of oat bran addition on the fatty acid composition, trans fatty acids, total fat, some physicochemical and sensory properties of the samples was studied. Meatballs were produced with four different formulations; the addition of 5, 10, 15 and 20% oat bran. Control samples were formulated with 25% fat addition as in commercial production. The major fatty acids were cis-oleic, palmitic and stearic acid in all the meatball samples, those with oat bran added as well as the control. Meatballs containing oat bran had lower concentrations of total fat and total trans fatty acids than the control samples. Meatballs made with 20% oat bran had the highest protein, salt and ash contents, L value (lightness), b value (yellowness), and the lowest moisture content and a value (redness). There was no significant difference among the meatball samples with respect to sensory properties, and all samples had high acceptability. 相似文献
12.
Orhan Ince Mustafa Kolukirik Nilgun Ayman Oz Bahar Kasapgil Ince 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2005,80(2):138-144
In this study, two full‐scale upflow anaerobic sludge blanket (UASB) reactors, namely TUASB and CUASB, at the wastewater treatment plants of the Tekirdaǧ Alcohol (Raki) and Canakkale Alcohol (Cognac) distilleries were investigated in terms of performance, acetoclastic methanogenic capacity and microbial composition. The results were compared with a previously studied other UASB reactor (IUASB) at the wastewater treatment plant of the Istanbul Alcohol (Raki) Distillery from which the two reactors (TUASB and CUASB) were seeded. The IUASB reactor performed well achieving COD removal efficiencies of no lower than 85% at organic logding rates (OLRs) in the range of 6–11 kg COD m−3 day−1 between 1996 and 2001. During the last one year of operation, between 2000 and 2001, performance of the CUASB reactor in terms of COD removal efficiency was 70–80% at OLRs in a range of 1–4.5 kg COD m−3 day−1 whereas it was 60–80% at OLRs in a range of 2.5–8.5 kg COD m−3 day−1 in the TUASB reactor. At the end of year 2000, specific methanogenic activity (SMA) tests were carried out to determine potential loading capacity and optimum operating conditions of the IUASB, CUASB and TUASB reactors. The potential methane production (PMP) rates of the CUASB, IUASB and TUASB reactors were measured as 230 cm3 CH4 gVSS−1 day−1, 350 cm3 CH4 gVSS−1 day−1 and 376 cm3 CH4 gVSS−1 day−1 respectively. When the PMP rates were compared with actual methane production (AMP) rates obtained from the three UASB reactors, AMP/PMP ratios were evaluated to be 0.18, 0.12 and 0.13 for CUASB, TUASB and IUASB reactors respectively. This showed that the CUASB, TUASB and IUASB reactors were using only 18%, 12% and 13% of their potential acetoclastic methanogenic capacity respectively. These results can be interpreted that the three UASB reactors were underloaded compared with their potential acetoclastic methanogenic capacities. It was, therefore, recommended that the three UASB reactors should be loaded at higher organic loading rates or sludge withdrawn in order to maintain an AMP/PMP ratio of 0.6–0.7, which can ensure desired reactor performance with safer operation. Results of epifluoresence microscopic examinations showed that the percentage of total autofluorescent methanogens was approximately 30% of the total population in sludges from the TUASB and IUASB reactors whereas it was 20% in sludge from the CUASB reactor. The two UASB reactors treating raki distillery wastewaters contained sludges having a higher percentage of autofluorescent methanogenic population and higher acetoclastic methanogenic activity. Copyright © 2004 Society of Chemical Industry 相似文献
13.
Wireless Networks - Due to the battery limitations, energy-efficient routing is one of the most important issues in WSNs. In this paper, a novel distributed clustering routing protocol (NODIC) is... 相似文献
14.
In this article, the electrodeposition process of Cu-Sn alloy powders from tripolyphosphate (TPP)-based electrolytes was investigated
as a function of deposition parameters. The effects of deposition parameters such as current density, electrolyte composition
(Cu/Sn mole ratio), mechanical stirring speed, and temperature on the Cu content of alloy powder and cathodic current efficiency
were evaluated using the response surface methodology (RSM). The empirical models developed in terms of deposition parameters
were found to be statistically adequate to describe the process responses. The study revealed that as far as the copper content
was concerned in the alloyed powders, all parameters selected had positive correlations. However, a high stirring speed and
low current density led to a greater current efficiency. The morphology and chemical composition of the electrodeposited Cu-Sn
alloy powders were investigated using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray
diffraction (XRD), and inductively coupled plasma (ICP) analysis. An SEM analysis showed that the powder morphology was affected
considerably by the cathodic current density and stirring speed. 相似文献
15.
Orhan Ozdemir Stoyan I. Karakashev Anh V. Nguyen Jan D. Miller 《Minerals Engineering》2009,22(3):263-271
In this study, the equilibrium and dynamic surface tensions of sodium chloride and potassium chloride solutions have been measured as a function of concentration up to saturation (5.2 M for NaCl and 4.1 M for KCl) using sessile bubble tensiometry. The experimental results show that the surface tension of these and other salts significantly increases with increasing concentration due to negative adsorption of ions at the air/brine interface, regardless of their structure maker and breaker nature. Furthermore, the effect of these salts on the surface tension of aqueous solutions of sodium dodecyl sulfate (SDS) and methyl isobutyl carbinol (MIBC) was also studied. These results show that the salts increased the surface activity of SDS and MIBC. In the case of SDS, KCl increased the surface activity of SDS more significantly than NaCl did. In the case of MIBC, the effect of NaCl on MIBC surface activity was more significant than that of KCl. 相似文献
16.
Sedat Türkmen Nuri
zgüzel 《Tunnelling and Underground Space Technology incorporating Trenchless Technology Research》2003,18(4):365
This paper describes the treatment of tunneling problems at Kurtkula
ı irrigation tunnel, particularly focusing on the Kurtkula
ı tunnel which is 1255 m in length and 3.50 m in diameter, is an important of the Yumurtalık Plain Irrigation Project. The tunnel was excavated using conventional dull and blast, but during the tunneling problems occurred. Within a 70 m long section of the tunnel, cave-in occurred at two locations both along the fault zone in tunnel alignment. Slope stability problems were experienced too at inlet and outlet section of the tunnel. A sinkhole was formed at the surface as a result of the cave-in. There are an Allocthonous Cretaceous complex sequence and Miocene sandstone–claystone units, which have a faulty contact in the tunnel alignment area. The complex sequence consists of mainly weathered andesite, spilitic agglomerate, radiolarite, serpentinite and limestone blocks. The claystone to sandstone is thin-medium bedded and has medium-weak rock substance properties. The fault zone with an approximate width of 150 m and consisting of extremely weak crushed rocks crosses the tunnel alignment at mid-section. Some treatment methods were applied to remedy this collapse. Cut and cover method was applied for the first 955 m of the tunnel inlet due to the shallow overburden and very weak rock properties. However, cave-ins delayed the tunnel construction for 1 year and increased the cost by 9%. 相似文献
17.
A technique, based on Echo planar imaging (EPI)-based phase modulation factor maps, is described for correction of EPI distortions resulting from field inhomogeneity. In this paper, a phase modulation factor was employed to remove the distortions. The phase modulation factor was obtained experimentally by collecting EPI images with a spin-echo (TE) spacing, deltaTE, equal to the inter-echo time interval, T(i). Then, the distortions resulting from the field inhomogeneity were removed by modulating the kappa-space data with the phase modulation factor. One of the advantages of this method is that it requires only a few extra scans to collect the information on field inhomogeneity. The proposed method does not require a phase unwrapping procedure for field inhomogeneity correction and, hence, is easier to implement, compared to other techniques. In addition, it corrects geometric distortion as well as intensity distortions simultaneously, which is robust to external noise or estimation error in severely distorted images. In this work, we also compared the proposed technique with others including, a) interpolation method with EPI-based displacement maps, and b) modulation method with phase modulation factor maps generated from spin-echo images. The results suggest the proposed technique is superior in correcting severely distorted images. 相似文献
18.
We consider the component testing problem of a series system with redundant subsystems where all components fail exponentially. The main feature of our model is that the component failure rates are not constant parameters, but in fact change in a dynamic fashion with respect to time. The optimal component testing problem is formulated as a semi-infinite linear program. We present an algorithmic procedure to compute optimal test times based on the column generation technique, and illustrate it with numerical results. 相似文献
19.
One of the major activities performed in product recovery is disassembly. Disassembly line is the most suitable setting to disassemble a product. Therefore, designing and balancing efficient disassembly systems are important to optimize the product recovery process. In this study, we deal with multi-objective optimization of a stochastic disassembly line balancing problem (DLBP) with station paralleling and propose a new genetic algorithm (GA) for solving this multi-objective optimization problem. The line balance and design costs objectives are simultaneously optimized by using an AND/OR Graph (AOG) of the product. The proposed GA is designed to generate Pareto-optimal solutions considering two different fitness evaluation approaches, repair algorithms and a diversification strategy. It is tested on 96 test problems that were generated using the benchmark problem generation scheme for problems defined on AOG as developed in literature. In addition, to validate the performance of the algorithm, a goal programming approach and a heuristic approach are presented and their results are compared with those obtained by using GA. Computational results show that GA can be considered as an effective and efficient solution algorithm for solving stochastic DLBP with station paralleling in terms of the solution quality and CPU time. 相似文献
20.
Kaan Sevki Kavak Orhan Tatar John Piper Fikret Kocbulut B. Levent Mesci 《International journal of remote sensing》2013,34(17):4507-4524
The junction between the East Anatolian and the Dead Sea fault zones lies close to an unstable F: Transform fault (FFF) triple junction where the African, Eurasian and Arabian plates meet in south-eastern Turkey. The Karasu Basin is an ephemeral rifted structure located close to the junction of these plate boundaries and is expressed by a range of tectono-morphological features. This study uses remote sensing to define tectonic structures and discriminate volcanic rocks linked to rifting within the basin using Landsat Enhanced Thematic Mapper Plus (ETM+) imagery. Prior to advanced image processing stages, images were corrected to eliminate atmospheric scattering effects and determine the best band combination for multi-spectral processing techniques based on statistical methods. Following pre-processing stages, edge detection filters were applied to derive tectonic structures defining the basin. The Brovey transformation, a statistical data merging method, was used to combine reflective multi-spectral bands with the Landsat ETM+?panchromatic band. This method fuses higher spatial data with data of lower spatial value. The western margin of the Karasu Basin is defined by the left-lateral Amanos Fault Zone with a contemporary motion (c. –0.4 mm a?1) probably accommodating most of the left-lateral strike-slip motion between Arabian and African plates on the northern continuation of the Dead Sea Fault Zone. The rift zone has been the site of extensive recent volcanism concentrated within the Brunhes Chron (<0.78 Ma) and linked to fault block rotations between the intracontinental master faults. The boundaries of this activity are defined here using a regolith mapping technique. 相似文献