全文获取类型
收费全文 | 144篇 |
免费 | 4篇 |
专业分类
电工技术 | 2篇 |
综合类 | 1篇 |
化学工业 | 29篇 |
金属工艺 | 4篇 |
机械仪表 | 2篇 |
建筑科学 | 4篇 |
能源动力 | 7篇 |
轻工业 | 17篇 |
水利工程 | 3篇 |
石油天然气 | 1篇 |
无线电 | 19篇 |
一般工业技术 | 26篇 |
冶金工业 | 7篇 |
原子能技术 | 3篇 |
自动化技术 | 23篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 6篇 |
2021年 | 8篇 |
2020年 | 10篇 |
2019年 | 6篇 |
2018年 | 8篇 |
2017年 | 10篇 |
2016年 | 9篇 |
2015年 | 2篇 |
2014年 | 8篇 |
2013年 | 15篇 |
2012年 | 10篇 |
2011年 | 14篇 |
2010年 | 8篇 |
2009年 | 4篇 |
2008年 | 4篇 |
2007年 | 1篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1978年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有148条查询结果,搜索用时 15 毫秒
51.
In the present work, the effect of temperature and solution pH on calcium carbonate precipitation from iron‐rich waters was investigated. Calcium carbonate was precipitated by CO2 removal. The increase in the temperature or the solution pH leads to the acceleration of calcium carbonate nucleation and crystal growth. Iron addition retards the formation of calcium carbonate crystals and enhanced the precipitation in the bulk solution. At high supersaturations, the inhibition effectiveness of iron is small and it could be improved by lowering the solution pH. The results of the present work show that it is possible to reduce or completely prevent scale formation in different water treatment processes by controlling the operating parameters which favourably affects the water treatment costs, increases the equipment life and allows increased product water recovery. 相似文献
52.
Faten Younsi Rym Trimech Abennacer Boulila Olfa Ezzine Samir Dhahri Mohamed Boussaid 《International Journal of Food Properties》2016,19(7):1425-1438
Total phenols, flavonoids, flavonols, and flavanols of the methanolic extract of the aerial part of Artemisia herba-alba were determined. The extract was analyzed by liquid chromatography with photodiode array coupled with electrospray ionisation mass spectrometry and allowed to identify of 10 phenolic compounds. Apigenin-6-C-glycosyl flavonoids and caffeoylquinic acids were identified. Chlorogenic acid and 1,4 dicaffeoylquinic acid being the major constituents. The essential oil obtained by hydrodistillation was analyzed by gas chromatography–mass spectrometry. Twenty-three compounds, representing 97.8% of the total oil, were identified. The most abundant components were β-thujone (41.9%), α-thujone (18.4%), and camphor (13.2%). Methanolic extract and essential oil exhibited a considerable antioxidant activity as evaluated by 2,2-diphenyl-pycrilhydrazil hydrate scavenging activity, reducing power, β-carotene bleaching test, and chelating ability. The methanolic extract was found to be more efficient, while the essential oil exhibited the highest acetylcholinesterase inhibitory activity. Analysis of the antibacterial activity showed that A. herba-alba methanolic extract and essential oil are efficient against gram positive and gram negative bacteria. 相似文献
53.
L. Pentti Karjalainen Atef Hamada R. Devesh K. Misra David A. Porter 《Scripta materialia》2012,66(12):1034-1039
Aspects of the mechanical behavior and microstructure evolution during the cyclic loading of twinning-induced plasticity steels are considered in order to provide deeper insights into their good fatigue strength. Experiments on an Fe–0.3C–16Mn–1.5Al steel in the high-cycle fatigue regime have demonstrated the beneficial influence of grain refinement. In the presence of a large grain size, cyclic loading is found to lead to the generation of twins in addition to extended dislocations and planar dislocation arrays. 相似文献
54.
Adel Abdelrazek Abdelazim Mohdaly Mohamed Atef Sarhan Awad Mahmoud Mohamed Fawzy Ramadan Iryna Smetanska 《Food chemistry》2010
The antioxidant properties of potato peels and sugar beet pulp, in comparison with synthetic antioxidant, were investigated. The bioactive materials were extracted with methanol and examined for their antioxidant activity under accelerated oxidation conditions, using sunflower and soybean oils as oxidation substrates at different concentrations for 72 h at 70 °C. Inverse relationships were noted between peroxide values and oxidative stabilities and also between secondary oxidation products, measured by p-anisidine value and stabilities at termination of the storage. Absorptivity at 232 nm and 270 nm increased gradually with the increase in time, due to the formation of conjugated dienes and polyenes. The order of oxidative stability was as follow: TBHQ > potato peels > BHT = sugar beet pulp > BHA. The predominant phenolic compounds identified by thin-layer chromatography in potato peels and sugar beet pulp were chlorogenic and gallic acids. The results of different antioxidant parameters demonstrated that potato peels and sugar beet pulp are potent sources of natural antioxidants that might be explored to prevent oxidation of vegetable oils. 相似文献
55.
Atef ShalabneyAuthor Vitae C. KhareAuthor VitaeB. RauschenbachAuthor Vitae I. AbdulhalimAuthor Vitae 《Sensors and actuators. B, Chemical》2011,159(1):201-212
Surface Plasmon Resonance (SPR) from metallic Columnar Thin Films (CTFs) of porosity as high as 0.5 was experimentally and theoretically investigated. The CTF layers were prepared by the Glancing Angle Deposition (GLAD) method. The SPR features were investigated in both the angular and the spectral modes. In the angular interrogation, increasing the porosity causes broadening to the dip width, shift to larger resonance angles, and increase of the sensitivity to analyte refractive index (RI) changes by about threefold compared with closed metal films. In the spectral interrogation, on the other hand, the resonance wavelengths are red-shifted for porous films; hence their spectral sensitivities are higher than those of closed films under the same experimental conditions. Nevertheless, the sensitivity behavior versus the resonance wavelength is similar to that of SPR sensors based on dense film layers. The shapes of the nanostructures constituting the CTF are described as ellipsoidal inclusions in which the effective permittivity dyadic of the composite material is calculated using the Bruggeman formalism with exact depolarization dyadics. The correlation between the sensitivity enhancement and the electromagnetic field intensity at the interface between the metallic film and the analyte was examined. Electromagnetic fields analyses were performed using the general 4 × 4 propagation matrices of general homogenous biaxial layers. 相似文献
56.
This paper contains a comparative economic study of a number of different expansion schedules for power and desalination plants required to meet a forecasted demand in electricity and water for the Emirate of Abu Dhabi. For power generation, steam turbine and gas turbine plants were considered and for desalination both multistage flash distillation and reverse osmosis processes were investigated. Nine combinations of power and desalination plants were selected and a present worth economic analysis was conducted. Capital and operating cost figures used are those typical of the local conditions at Abu Dhabi. Based on the assumptions used in this study the plant combination using steam turbine power plant connected to a reverse osmosis unit seems to represent the most economic alternative. 相似文献
57.
Inference for a geometric‐poisson‐Rayleigh distribution under progressive‐stress accelerated life tests based on type‐I progressive hybrid censoring with binomial removals
下载免费PDF全文
![点击此处可从《Quality and Reliability Engineering International》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Saralees Nadarajah Alaa H. Abdel‐Hamid Atef F. Hashem 《Quality and Reliability Engineering International》2018,34(4):649-680
Based on failures of a parallel‐series system, a new distribution called geometric‐Poisson‐Rayleigh distribution is proposed. Some properties of the distribution are discussed. A real data set is used to compare the new distribution with other 6 distributions. The progressive‐stress accelerated life tests are considered when the lifetime of an item under use condition is assumed to follow the geometric‐Poisson‐Rayleigh distribution. It is assumed that the scale parameter of the geometric‐Poisson‐Rayleigh distribution satisfies the inverse power law such that the stress is a nonlinear increasing function of time and the cumulative exposure model for the effect of changing stress holds. Based on type‐I progressive hybrid censoring with binomial removals, the maximum likelihood and Bayes (using linear‐exponential and general entropy loss functions) estimation methods are considered to estimate the involved parameters. Some point predictors such as the maximum likelihood, conditional median, best unbiased, and Bayes point predictors for future order statistics are obtained. The Bayes estimates are obtained using Markov chain Monte Carlo algorithm. Finally, a simulation study is performed, and numerical computations are performed to compare the performance of the implemented methods of estimation and prediction. 相似文献
58.
B. Priestly Shan O. Jeba Shiney Sharzeel Saleem V. Rajinikanth Atef Zaguia Dilbag Singh 《计算机、材料和连续体(英文)》2022,72(2):2749-2763
Low contrast of Magnetic Resonance (MR) images limits the visibility of subtle structures and adversely affects the outcome of both subjective and automated diagnosis. State-of-the-art contrast boosting techniques intolerably alter inherent features of MR images. Drastic changes in brightness features, induced by post-processing are not appreciated in medical imaging as the grey level values have certain diagnostic meanings. To overcome these issues this paper proposes an algorithm that enhance the contrast of MR images while preserving the underlying features as well. This method termed as Power-law and Logarithmic Modification-based Histogram Equalization (PLMHE) partitions the histogram of the image into two sub histograms after a power-law transformation and a log compression. After a modification intended for improving the dispersion of the sub-histograms and subsequent normalization, cumulative histograms are computed. Enhanced grey level values are computed from the resultant cumulative histograms. The performance of the PLMHE algorithm is compared with traditional histogram equalization based algorithms and it has been observed from the results that PLMHE can boost the image contrast without causing dynamic range compression, a significant change in mean brightness, and contrast-overshoot. 相似文献
59.
Salha Boulila Hassane Oudadesse Hafed Elfeki Rim Kallel Bertrand Lefeuvre Mostafa Mabrouk Slim Tounsi Dhekra Mhalla Amany Mostafa Khansa Chaabouni Fatma Makni-Ayedi Allal Barroug Tahia Boudawara Abdelfattah Elfeki 《Korean Journal of Chemical Engineering》2016,33(5):1659-1668
Bioactive glass particle is used in the repair of bone defects. This material undergoes a series of surface in vivo reactions, which leads to osteointegration. We evaluated the effect of the bioactive glass synthesis, sol-gel (BG(S)) versus melting (BG(M)), associated with polyvinyl-alcohol (PVA) on in vivo bioactivity with biochemical parameters, liver-kidney histological structure and antibacterial in vitro activity. These composites were testified in many bacteria and implanted in ovariectomized rat. The serum and organs (liver and kidney) of all groups, control and treated rats, were collected to investigate the side effects of our composites, BG(S)-PVA and BG(M)-PVA, in comparison with control and ovariectomized rats. Also, the implants, before and after implantation, were prepared for analysis using physicochemical techniques such as Fourier transform infrared spectroscopy and X-ray diffraction. Our results have shown the stability of natremia, kaliemia, calcemia and phosphoremia. The histological structures of liver and kidney in implanted rats are intact compared to control and ovariectomized rats. BG(S)-PVA is characterized by a higher antibacterial effect on negative and positive gram bacteria than BG(M)-PVA. The physicochemical results have confirmed a progressive degradation of BG(S)-PVA and BG(M)-PVA, while replacing the implant by an apatite layer. But this bioactivity of BG(S)-PVA is faster than BG(M)-PVA. We can therefore confirm, on the one hand, the biocompatibility of our two implants and, on the other hand, the beneficial effect of sol-gel synthesis technique versus melting, both on the antibacterial effect and on the rapid formation of layer hydroxyapatite, and consequently on osteogenesis. 相似文献
60.