全文获取类型
收费全文 | 139篇 |
免费 | 12篇 |
专业分类
化学工业 | 25篇 |
金属工艺 | 15篇 |
机械仪表 | 3篇 |
建筑科学 | 8篇 |
能源动力 | 9篇 |
轻工业 | 35篇 |
水利工程 | 3篇 |
石油天然气 | 1篇 |
无线电 | 17篇 |
一般工业技术 | 25篇 |
自动化技术 | 10篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 9篇 |
2019年 | 6篇 |
2018年 | 16篇 |
2017年 | 3篇 |
2016年 | 7篇 |
2015年 | 10篇 |
2014年 | 9篇 |
2013年 | 19篇 |
2012年 | 5篇 |
2011年 | 16篇 |
2010年 | 5篇 |
2009年 | 14篇 |
2008年 | 3篇 |
2007年 | 6篇 |
2006年 | 1篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2002年 | 3篇 |
2001年 | 4篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1987年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有151条查询结果,搜索用时 125 毫秒
111.
On the surface of a Fe catalyst carbon monoxide disproportionates into C (carbon black) and CO2. Kinetic parameters of this reaction (reaction rate constant, order, and occupancy of catalyst surface) were established in the range of temperatures 430–490°C. At the beginning of the process in all cases an induction period was observed. Under definite conditions the process develops with oscillating dynamics. Induction period and oscillations indicate an autocatalytical nature of the process. The distribution of the Fe catalyst in the profile of the reaction zone (in the bulk of carbon black and on the surface of small crystals) was investigated. 相似文献
112.
A. Survila Z. Mockus S. Kanapeckaitė M. Samulevičienė V. Jasulaitenė 《Protection of Metals and Physical Chemistry of Surfaces》2009,45(4):455-460
Voltammetry and electrochemical impedance spectroscopy (EIS) are used in studying the kinetics of electroplating tin from 0.01 M Sn(II) baths containing 1 M H2SO4 and millimolar benzaldehyde (BA) additives. BA substantially decreases the reduction rate of Sn(II) in a broad range of cathodic polarization. Experimental EIS data are analyzed in terms of an equivalent Rω(Qdl[RaCaWa][RctQd]) circuit, including a Faraday process impedance ([RctQd] subcircuit), as well as diffusion and kinetic stages of BA adsorption ([RaCaWa] subcircuit). Values of the subcircuit elements are found to depend on the duration of a contact between the electrode and solution and on the BA concentration. An increase in the charge transfer resistance (Rct) and a simultaneous decrease in the double layer capacitance (Qdl) indicate that the electrochemical reduction of Sn(II) is inhibited by the BA adsorption. With an increase in the cathodic polarization, the effect becomes more pronounced, which is manifested in the low current densities and negative impedance values. 相似文献
113.
Basic features of confined electron scattering in quantum wells (QWs) by confined polar optical (PO) phonons are analyzed. The dependence of electron mobility in Al0.25Ga0.75As/GaAs/Al0.25Ga0.75As QWs on the well width is calculated. It is demonstrated that increases and decreases in electron mobility (relative to the bulk value) as a function of the QW width occur due to resonance intersubband scattering. The dependence of electron mobility limited by PO phonon scattering on the electron density n s in the QW is calculated. It is shown that anomalous behavior of electrical conductivity, which in certain cases decreases with increasing electron density, can take place in Al0.25Ga0.75As/GaAs/Al0.25Ga0.75As QWs for n s >1016 m?2. 相似文献
114.
Greta Švermickaitė Viktorija Eisinaitė Rimantė Vinauskienė Ina Jasutienė Daiva Leskauskaitė 《International Journal of Food Science & Technology》2022,57(7):4441-4450
In this study, aerogels were prepared from kognac glucomannan (KG) or whey proteins loaded with bioactive sea buckthorn pomace extract. KG was diacetylated with Na2CO3 (0.1; 0.2; 0.3; 0.4 m ) resulting hydrogel formation that were further freeze-dried to obtain an aerogel structure. Whey protein aerogels were prepared by removing pore fluid from alcogels using supercritical CO2 drying. Produced aerogels evaluated for microstructure, porosity, specific surface area, absorption capacity, encapsulation efficiency and antioxidant capacity of the extract. It was found that higher concentration of alkali induced higher hardness, resilience and elastic modulus values. It was also obtained that pores in the konjac glucomannan aerogels were irregular in shape and a decrease in total pore volume (0.026 to 0.019 cc/g) and surface area (12.39 to 11.40 m2/g) after increasing the carbonate concentration was observed. These aerogels were found to have better encapsulation efficiency properties for sea buckthorn pomace extract (17 to 20%) in comparison to whey protein aerogels (0.05 to 0.36%). Overall, the KG aerogels show potential for applications in the food industry as a carrier of bioactive sea buckthorn pomace extract, while whey proteins must be used in combination with other biopolymers to enhance their bioactive compound loading capacity. 相似文献
115.
116.
117.
118.
Detection of Salmonella spp., Yersinia enterocolitica,Listeria monocytogenes and Campylobacter spp. by real‐time multiplex PCR using amplicon DNA melting analysis and probe‐based assay
下载免费PDF全文
![点击此处可从《International Journal of Food Science & Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jūratė Skerniškytė Julija Armalytė Raimonda Kvietkauskaitė Vaida Šeputienė Justas Povilonis Edita Sužiedėlienė 《International Journal of Food Science & Technology》2016,51(2):519-529
Syto9 and probe‐based multiplex real‐time PCR assays for simultaneous detection of a group of foodborne pathogens (named SYLC group), targeting Salmonella spp. (invA gene), Yersinia enterocolitica (ystA gene), Listeria monocytogenes (hly gene) and Campylobacter spp. (rrna gene), have been developed. The Syto9 assay generates amplicon DNA melting curve with four peaks of 86.5 ± 0.5, 84 ± 0.5, 81.5 ± 0.5 and 90.5 ± 0.5 °C corresponding Salmonella spp., Y. enterocolitica, L. monocytogenes and Campylobacter spp. targets, respectively. The sensitivities of the Syto9 and TaqMan assays in artificially inoculated chicken wing rinses were in a range of 3.2 × 102 to 3.1 × 104 and 9.8 × 102 to 1.9 × 104 colony‐forming units per millilitre, respectively, depending on the pathogen. All tested target strains (n = 100) were correctly detected by the both assays, whereas nontarget strains (n = 100) demonstrated no cross‐reactivity representing 100% specificity. The assays are suitable for application in qualitative and quantitative detection of SYLC group pathogens in food matrices. 相似文献
119.
Henrikas Sivilevičius Valentinas Podvezko Sigutė Vakrinienė 《Construction and Building Materials》2011,25(1):115-122
The paper describes the essential differences in determining optimal gradation of hot mix asphalt (HMA) mixture used in road building at the stages of its selection, initial design and production, and presents the respective algorithms. The models of constrained and unconstrained non-linear optimization are developed, allowing us to choose the best HMA mixture gradation based on mineral materials, whose gradation is known, when the total percent passing of HMA mixture aggregates is considered to be equally important for all sieves, or when preference is given to some of the sieves. A new linear optimization problem best suited for practical use due to its simplicity is offered. By introducing weight coefficients for the dimensions of the objective function of the model, zero deviations of the percent passing of HMA mixture aggregates from their standard values may be easily obtained, based on the preferences set. All mineral materials (aggregates) obtained at batch-type asphalt mixing plants should be used for HMA production. Their total mass is equal to unity, while the mass of each material is a positive quantity, and a predetermined relationship between the masses of imported filler and the reclaimed dust is used. In the experimental part of the work, the problems were solved using the SAS system. 相似文献
120.
Indrė Žliobaitė 《Knowledge and Information Systems》2014,39(3):565-578
We study evaluation of supervised learning models that adapt to changing data distribution over time (concept drift). The standard testing procedure that simulates online arrival of data (test-then-train) may not be sufficient to generalize about the performance, since that single test concludes how well a model adapts to this fixed configuration of changes, while the ultimate goal is to assess the adaptation to changes that happen unexpectedly. We propose a methodology for obtaining datasets for multiple tests by permuting the order of the original data. A random permutation is not suitable, as it makes the data distribution uniform over time and destroys the adaptive learning task. Therefore, we propose three controlled permutation techniques that make it possible to acquire new datasets by introducing restricted variations in the order of examples. The control mechanisms with theoretical guarantees of preserving distributions ensure that the new sets represent close variations of the original learning task. Complementary tests on such sets allow to analyze sensitivity of the performance to variations in how changes happen and this way enrich the assessment of adaptive supervised learning models. 相似文献