全文获取类型
收费全文 | 415篇 |
免费 | 23篇 |
专业分类
电工技术 | 3篇 |
综合类 | 1篇 |
化学工业 | 144篇 |
金属工艺 | 2篇 |
机械仪表 | 4篇 |
建筑科学 | 11篇 |
能源动力 | 22篇 |
轻工业 | 82篇 |
水利工程 | 6篇 |
石油天然气 | 4篇 |
无线电 | 18篇 |
一般工业技术 | 64篇 |
冶金工业 | 27篇 |
原子能技术 | 1篇 |
自动化技术 | 49篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 17篇 |
2020年 | 9篇 |
2019年 | 20篇 |
2018年 | 25篇 |
2017年 | 15篇 |
2016年 | 11篇 |
2015年 | 13篇 |
2014年 | 20篇 |
2013年 | 50篇 |
2012年 | 21篇 |
2011年 | 45篇 |
2010年 | 27篇 |
2009年 | 25篇 |
2008年 | 24篇 |
2007年 | 21篇 |
2006年 | 24篇 |
2005年 | 13篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 9篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 9篇 |
1997年 | 2篇 |
1995年 | 2篇 |
1994年 | 2篇 |
排序方式: 共有438条查询结果,搜索用时 171 毫秒
61.
Atmospheric particulate matter (PM) fractions (PM(10) and PM(2.5)) were sampled concurrently between June 2004 and May 2005 at two sites (urban and suburban) in Izmir, Turkey. The elemental composition of PM (Al, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr, V, and Zn) was determined using inductively coupled plasma-optical emission spectrometer. Elemental compositions of several PM sources were also characterized. Positive matrix factorization (PMF) and chemical mass balance modeling (CMB) were applied to determine the PM sources and their contributions to air concentrations. The major contributors to PM were fossil fuel burning, traffic emissions, mineral industries and marine salt according to the PMF results. However, undetermined parts were more than 40%. On the other hand, the contributions to PM could be determined completely by CMB, and the dominant contributor was traffic with >70% at the two sites. Fossil fuel burning, mineral industries, marine salt and natural gas-fired power plant were the minor contributors. 相似文献
62.
63.
Surface and thin film analysis – indispensable tool for coating development and ‐production A low‐carbon (0.097 wt%) steel was annealed at 820°C for 60 min. then quenched in water to develop the desired dual phase steel (DPS) structure of martensite and ferrite. The intercritically annealed steel exhibited a microstructure of equiaxed ferrite‐martensite. Continuous yielding was observed at the stress‐strain curves. New equation was developed to predict the empirical tensile strengths of DPS. Empirical results were compared with experimental data in this study and the literature. A difference changing between ± 10% was observed for experimental and empirical results. 相似文献
64.
Dilek Kazan Altan Erarslan 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1999,74(12):1157-1164
The stabilisation of Escherichia coli penicillin G acylase (PGA) by dextran polymers (of molecular weight 11.5, 37.7 and 71 kDa) was studied. The inactivation of both the native and dextran‐containing enzyme preparations obeyed first‐order kinetics at the temperature and pH values studied. The optimal concentrations of dextran polymers of molecular weight 11.5, 37.7 and 71 kDa stabilising PGA against inactivation were 50, 20 and 7.5 mmol dm−3 respectively. Dextran 11500 (11.5 kDa) gave 100‐fold protection of PGA against thermal inactivation of enzyme above 50 °C. The kinetic constants of the enzyme were slightly altered, but temperature and pH profiles were not altered by the dextrans. © 1999 Society of Chemical Industry 相似文献
65.
This study explores the use of augmented reality smart glasses (ARSGs) by physicians and their adoption of these products in the Turkish medical industry. Google Glass was used as a demonstrative example for the introduction of ARSGs. We proposed an exploratory model based on the technology acceptance model by Davis. Exogenous factors in the model were defined by performing semi-structured in-depth interviews, along with the use of an expert panel in addition to the technology adoption literature. The framework was tested by means of a field study, data was collected via an Internet survey, and path analysis was used. The results indicate that there were a number of factors to be considered in order to understand ARSG adoption by physicians. Usefulness was influenced by ease of use, compatibility, ease of reminding, and speech recognition, while ease of use was affected by ease of learning, ease of medical education, external influence, and privacy. Privacy was the only negative factor that reduced the perceived ease of use, and was found to indirectly create a negative attitude. Compatibility emerged as the most significant external factor for usefulness. Developers of ARSGs should pay attention to healthcare-specific requirements for improved utilization and more extensive adoption of ARSGs in healthcare settings. In particular, they should focus on how to increase the compatibility of ARSGs. Further research needs to be conducted to explain the adoption intention of physicians. 相似文献
66.
Yttrium aluminium garnet(Y_3 Al_5 O_(12):YAG) singly doped with Dy3+ at different concentrations was prepared by solid state reactions using repeated heating cycles over the temperature range of 1300-1600 ℃. X-ray powder diffraction analysis confirms the presence of a well-crystallized YAG perovskite phase with cubic structure(by Rietveld refinement). The rare earth dopant is successfully integrated into the YAG host lattice without any major changes in the original structure. The temperature dependence,up to 250 ℃, of the conductivity, dielectric constant, dielectric loss, and loss tangent, at various frequencies of up to 5.0 MHz for undoped and doped crystals is compared to understand the electrical and structural characteristics. The experimental results reveal that Dy3+ dopants in YAG crystal significantly influence the conductivity, dielectric constant, and lossy mechanisms, which is probably due to the 3 d-AI ions and 4 f-Dy ions incorporated at different positions of both tetrahedral and octahedral symmetries in YAG:xDy3+ ceramics. 相似文献
67.
Didehan Özhan R. Ertan Anli Nilufer Vural Mustafa Bayram 《Journal of the Institute of Brewing》2009,115(1):71-77
Cork taint is an off‐flavor problem in wine, the main reason being the presence of 2,4,6‐trichloroanisole (TCA) in the cork stopper. In addition to the TCA, the presence of other chloroanisole and chlorophenol family compounds (the perception limits of which are very low) can also result in, or contribute to, cork taint problem. In this study, the levels of 2,4‐dichloroanisole (DCA), 2,4,6‐trichloroanisole (TCA), 2,3,4,6‐tetrachloroanisole (TeCA), pentachloroanisole (PCA), 2,4,6‐trichlorophenol (TCP), 2,3,4,6‐tetrachlorophenol (TeCP) and penthaclorophenol (PCP) were assayed in cork stoppers (natural, agglomerated and colmate) and in red wine samples from different wineries in Turkey using HS‐SPME and GC‐ECD detection. The performance parameters for all chloroanisole and chlorophenol compounds were as follows: recovery 92.48–102.53%, R 0.992‐0.996. The LOQ values were DCA (8.4 ng/L), TCA (0.8 ng/L), TeCa (0.6 ng/L), PCP (0.8 ng/L), TCP (0.8 ng/L), TeCP (1.2 ng/L), and PCP (1.1 ng/L) respectively. In cork stoppers, the amounts of 2,4,6 TCA ranged between 5.4–130.6 ng/g. The 2,3,4,6 TeCA ranged between 1.12‐8.2 ng/g and the PCA ranged between nd (not detected)‐11.01 ng/g. In the wine samples, 2,4,6 TCA ranged between 1.42–70.2 ng/L. The 2,3,4,6 TeCA ranged between nd‐15.1 ng/L and the PCA ranged from nd‐5.16 ng/L. The results indicated that there was a significant correlation between the TCA in wines and the TCA in cork stoppers. 相似文献
68.
Burcu Olanca Dilek Sivri Ozay Hamit Koksel 《European Food Research and Technology》2009,229(5):813-820
Wholemeal samples were obtained from five durum wheat cultivars at two different bug (Eurygaster spp.) damage levels (medium and high damage). The samples were incubated (60 and 120 min) and used in size exclusion high
performance liquid chromatography (SE-HPLC) analyses. The results showed that the amount of larger polymeric protein (TP1)
and smaller polymeric protein (TP2) obtained from total (sodium dodecyl sulfate soluble) proteins decreased significantly
in the bug-damaged samples, while the amount of total larger monomeric proteins (TP3) increased. The polymeric/monomeric protein
ratio of all cultivars decreased at 60 min of incubation with increasing damage level. For all cultivars, the ratio of unextractable
polymeric protein (UPP%) significantly decreased at 60 min of incubation except cv. Diyarbakir. The results suggested that
bug protease caused depolymerization and/or disaggregation of polymeric proteins to lower their average molecular size. The
changes in protein structure as determined using SE-HPLC supported by the decreases in gluten content and gluten index values
which decreased with suni-bug damage. Deteriorative effects of bug damage on durum wheat quality were found to be quite similar
to those on bread wheats. 相似文献
69.
Selenium, copper, nickel, zinc, cadmium, manganese, iron, copper and lead contents of certain fish, meat and meat products consumed in Turkey were determined using inductively coupled plasma-optical emission spectrometry (ICP-OES). The order of the elements in the meat, meat products and fish samples and their concentration ranges in μg 100 g−1 was Fe (57.7–156.4) > Zn (20–159) > Ni (8.2–24) > Pb (11.5–13.5) > Cr (8.44–9.51) > Cu (7.18–10.01) > Cd (0.77–1.04) > Mn (3.98–10) > Se (1.32–4.6). The elemental concentrations of fish studied seemed to be close to the international standards. The highest trace element concentrations were obtained from past?rma, meat and sausage while the lowest value was observed in Trachurus trachurus (saurel). Iron concentrations in all samples were higher than the recommended values. 相似文献
70.
Use of the Weibull model for lactococcal bacteriophage inactivation by high hydrostatic pressure 总被引:1,自引:0,他引:1
Avsaroglu MD Buzrul S Alpas H Akcelik M Bozoglu F 《International journal of food microbiology》2006,108(1):78-83
Four lactococcal bacteriophages (phiLl6-2, phiLl35-6, phiLd66-36 and phiLd67-42) in M17 broth were pressurized at 300 and 350 MPa at room temperature and their survival curves were determined at various time intervals. Tailing (monotonic upward concavity) was observed in all survival curves. The resulting non-linear semi-logarithmic survival curves were described by the Weibull model and goodness of fit of this model was investigated. Regression coefficients (R2), root mean square error (RMSE), residual and correlation plots strongly suggested that Weibull model produced a better fit to the data than the traditional linear model. Hazard plots suggested that the Weibull model was fully appropriate for the data being analyzed. These results have confirmed that the Weibull model, which is mostly utilized to describe the inactivation of bacterial cells or spores by heat and pressure, could be successfully used in describing the lactococcal bacteriophage inactivation by high hydrostatic pressure. 相似文献