全文获取类型
收费全文 | 281篇 |
免费 | 16篇 |
专业分类
电工技术 | 2篇 |
综合类 | 1篇 |
化学工业 | 73篇 |
金属工艺 | 5篇 |
机械仪表 | 9篇 |
建筑科学 | 15篇 |
矿业工程 | 1篇 |
能源动力 | 21篇 |
轻工业 | 42篇 |
水利工程 | 4篇 |
石油天然气 | 1篇 |
无线电 | 18篇 |
一般工业技术 | 60篇 |
冶金工业 | 10篇 |
自动化技术 | 35篇 |
出版年
2024年 | 2篇 |
2023年 | 6篇 |
2022年 | 7篇 |
2021年 | 12篇 |
2020年 | 10篇 |
2019年 | 10篇 |
2018年 | 14篇 |
2017年 | 7篇 |
2016年 | 21篇 |
2015年 | 7篇 |
2014年 | 14篇 |
2013年 | 27篇 |
2012年 | 16篇 |
2011年 | 24篇 |
2010年 | 23篇 |
2009年 | 26篇 |
2008年 | 15篇 |
2007年 | 13篇 |
2006年 | 4篇 |
2005年 | 11篇 |
2004年 | 5篇 |
2003年 | 7篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
排序方式: 共有297条查询结果,搜索用时 15 毫秒
81.
82.
Jiangtao Sun Alvin Yung Boon Chong Siamak Tavakoli Guojin Feng Jamil Kanfoud Cem Selcuk 《Research in Nondestructive Evaluation》2019,30(4):205-230
An enhanced technique using image processing has been developed for automated ultrasonic inspection of composite materials, such as glass/carbon-fibre-reinforced polymer (GFRP or CFRP), to ascertain their structural healthiness. The proposed technique is capable of identifying the abnormality features buried in the composite by image filtering and segmentation applied to ultrasonic C-Scan images. This work presents results performed on two composite samples with simulated delamination defects. A local gating scheme is applied to raw A-Scan data for improved contrast between defective and healthy regions in the produced C-Scan image. In this test campaign, different filtering and thresholding algorithms are evaluated and compared in terms of their effectiveness on defect identification. The accuracies of less than 3 mm and 1.11 mm were attained for the defect size and depth, respectively. The results demonstrates the applicability of the proposed technique for accurate defect localization and characterization of composite materials. 相似文献
83.
Information axiom, one of two axioms of axiomatic design methodology which is proposed to improve a design, is used to select the best design among proposed designs. In the literature, there are a lot of studies related to using of information axiom for the solution of decision making problems. Moreover, applications of information axiom have been increasing day by day. However, calculation procedure of information axiom is not only incommodious but also difficult for decision makers. In this paper, a decision support system (DSS) based on fuzzy information axiom (FIA) is developed in order to make this decision procedure easy. The developed system consists of a knowledge base module including facts and rules, inference engine module including FIA and aggregation method, and a user interface module including entrance windows. The main aim of this study is to present a DSS tool to help the decision makers to solve their decision problems by modifying data-base of the program. In this paper, an application procedure will be presented based on the optimal selection of location for emergency service to illustrate the implementation procedure of the proposed model. 相似文献
84.
In this study, cylindrical porous glass tablets were plated by palladium using electroless plating technique. Hypophosphite and Co(II) complexes were used as reducing agents in the prepared plating baths. Experiments were carried out in an especially designed glass vessel in which helium gas was continuously bubbled through the solution to create uniform concentration and to remove hydrogen gas from the surface for the case of hypophosphite-based procedure. XRF analysis of the upper layer of the composite membrane prepared by the hypophosphite-based bath showed a Pd/Si ratio of 4.6. SEM photographs indicated impregnation of Pd into the substrate upto 200 μm. However, the thickness of the dense Pd layer was only about 15 μm. SEM photographs and XRF results showed that hypophosphite-based bath was much more successful than the Co(II) complex-bath in Pd plating. Permeation experiments carried out at different temperatures showed that the contribution of surface diffusion to the permeation was significant at low temperatures and solution–diffusion mechanism was not important in the 40–200 °C temperature range for these membranes. The selectivity ratio for H2/N2 was found to be about 7 at 200 °C. 相似文献
85.
In the present study comparative electrochemical study of methanol electro-oxidation reaction, the effect of ruthenium addition and experimental parameters on methanol electro-oxidation reaction at high performance carbon supported Pt and Pt–Ru catalysts have been studied by cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) in H2SO4 (0.05–2.00 M) + CH3OH (0.01–4.00 M) at 20–70 °C. Tafel plots for the methanol oxidation reaction on Pt and Pt–Ru catalysts show reasonably well-defined linear region with the slopes of 128–174 mV dec−1(α = 0.34–0.46). The activation energies from Arrhenius plots have been found as 39.06–50.65 kJ mol−1. As a result, methanol oxidation is enhanced by the addition of ruthenium. Furthermore, Pt–Ru (25:1) catalyst shows best electro–catalytic activity, higher resistance to CO, and better long term stability compared to Pt–Ru (3:1), Pt–Ru (1:1), and Pt. Finally, the EIS measurements on Pt–Ru (25:1) catalyst reveals that methanol electro-oxidation reaction consists of two process: methanol dehydrogenation step at low potentials (<700 mV) and the oxidation removal of COads by OHads at higher potentials (>700 mV). 相似文献
86.
Effects of fat level (5%, 10%, 20%) and corn flour (0%, 2%, 4%) on some properties of Turkish type meatballs (koefte) 总被引:1,自引:0,他引:1
In this study the effects of fat level (5%, 10% and 20%) and corn flour (CF 0%, 2% and 4%) on chemical composition, cooking characteristics and sensory properties of Turkish type meatballs were evaluated. Cooking characteristics were evaluated by measuring cooking yield, fat retention, moisture retention, reduction in diameter and thickness and shrinkage. At each fat level, incorporation of CF significantly increased protein content but had no significant effect on fat content of cooked meatballs. Decreasing the fat content from 20% to 5% significantly increased cooking yield and fat retention. Meatballs formulated with 20% fat had the highest reduction in diameter. CF had no effect on reduction in diameter. CF reduced shrinkage in meatballs formulated with 5% or 10% fat and increased moisture retention in treatments formulated with 5% or 10% fat. Sensory evaluation indicated that decreasing fat level resulted in lower texture and overall palatability scores. CF had no detrimental effect on sensory properties except appearance. 相似文献
87.
A grounded negative inductance emulator is proposed with full
independent control on both the inductance value and the
condition. It uses a single operational transresistance amplifier
(OTRA), a capacitor, and five resistors, two of which are for
independent control. Experimental results, which confirm the
theoretical analysis, are presented. 相似文献
88.
The study proposes direct particle size measurement by sequential filtration and ultrafiltration as a convenient method for wastewater characterization for appropriate treatment technology. It also explores the correlation between particle size distribution (PSD) and chemical oxygen demand (COD) fractionation, as an index for biological treatability. Profiles obtained through PSD-based COD fractionation serve as the fingerprints for wastewaters, and as demonstrated in this study, reflect different pictures for textile wastewater and domestic sewage. PSD-based COD fractionation profiles identify the soluble range below 2 nm as the size interval housing both the soluble inert COD initially present in the wastewater and soluble inert microbial products generated during biological treatment, as also supported by the metabolic fractionation attained through respirometric analyses. Moreover, PSD-based color profiling offers a good index for the fate of biologically resistant chemicals passing through biological treatment. Compatible results obtained from comparative evaluation of PSD-based COD and color profiles provide useful information on the biodegradability of the textile wastewater studied. 相似文献
89.
Ozlem Sahin Derya Duzenli Hilal Kivrak 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2016,38(5):628-634
Carbon supported Pt-Ru catalysts were prepared at varying Pt:Ru ratios by polyol method. The crystallite sizes of these catalysts were determined by X-ray diffraction technique. The specific surface areas of these catalysts were also defined by Brunauer–Emmett–Teller technique. Cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy measurements were conducted on these carbon supported Pt-Ru catalysts to investigate the effect of ruthenium on the ethanol electrooxidation kinetics. Results indicated that Pt-Ru (25:1) catalyst showed the best ethanol electrooxidation activity. In conclusion, ethanol electrooxidation mechanism was proposed. 相似文献
90.