全文获取类型
收费全文 | 56篇 |
免费 | 2篇 |
专业分类
化学工业 | 18篇 |
机械仪表 | 5篇 |
建筑科学 | 4篇 |
能源动力 | 4篇 |
轻工业 | 5篇 |
无线电 | 6篇 |
一般工业技术 | 10篇 |
冶金工业 | 5篇 |
自动化技术 | 1篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 3篇 |
2014年 | 6篇 |
2013年 | 3篇 |
2012年 | 2篇 |
2011年 | 3篇 |
2010年 | 5篇 |
2009年 | 4篇 |
2008年 | 3篇 |
2007年 | 3篇 |
2006年 | 6篇 |
2005年 | 1篇 |
2003年 | 1篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1992年 | 1篇 |
1989年 | 1篇 |
排序方式: 共有58条查询结果,搜索用时 15 毫秒
1.
In this study, AA7075 aluminum matrix composites reinforced with the combination of SiC, Al2O3, and B4C particles were fabricated by the liquid metal infiltration method. The effects of the relative ratio of B4C and Al2O3 particles on the microstructural, wear, and corrosion features of the composite samples were analyzed using XRD, light metal microscopy, SEM, EDS, Brinell hardness, ball-on-disc type tribometer, and potentiodynamic polarization devices. It was determined that infiltration occurred more successfully, and homogenously distributed particles with reduced porosity were obtained as the amount of Al2O3 increased. Worn surface studies revealed that the specimens were predominantly worn by abrasion and adhesion. The increase in B4C/Al2O3 ratio caused a decrease in the hardness and wear strength, whereas it increased the corrosion resistance. 相似文献
2.
A miniature printed antenna exploiting magnetic photonic crystal (MPC) modes is presented. The MPC mode is typically found in volumetric anisotropic materials and is realized here using a set of coupled printed transmission lines. The printed element is formed by a pair of unit cells, cascaded to realize a circularly periodic structure. To excite the nonreciprocal MPC mode, the coupled microstrip lines are printed on a uniform substrate with magnetic material inserts. A printed and slot (cavity-backed) version of the MPC-based element is designed and constructed. It is found that the cavity-backed version is better suited for reducing platform interactions, thus, avoiding detuning when installed on smaller platforms. Tunable magnetic biasing is also explored to improve functionality. The paper concludes by providing the in situ performance of the cavity-backed and recessed MPC antennas. 相似文献
3.
Research has shown that most reported foodborne outbreaks are caused by food prepared and consumed at home, thus emphasizing the importance of consumer food safety knowledge. In this study, 2,000 randomly selected residents from ?anakkale, Turkey, participated in face-to-face interviews to assess their food safety perceptions and practices. Questions covered the attention given to expiration dates, safety certificates, and food additives during shopping; consumption of high-risk foods; safe food handling; storage knowledge; and their source of food safety knowledge. Statistical analyses were done to clarify the differences according to three main aspects: gender, age, and educational level. Results showed that women and middle-aged respondents were significantly more careful during shopping and more interested in food safety issues than men and younger individuals. A significant relationship was found between gender and consumption of high-risk foods, with men consuming more of these foods than women. Furthermore, high-risk foods were more frequently consumed by young participants than by older participants, with more highly educated consumers shopping more consciously. Although most respondents appeared to know proper food handling and storage practices, almost all participants lacked some information on some issues. In order to remove these deficiencies, a brochure was prepared and distributed to people in various parts of the city. In addition, public seminars were organized. However, to ensure that this information results in positive attitude and behavioral changes, seminars should be repeated at specific intervals, and education procedures and processes should be controlled regularly. 相似文献
4.
Ibrahim Gunes Adem Cicek Kubilay Aslantas Fuat Kara 《Transactions of the Indian Institute of Metals》2014,67(6):909-917
In this study, the effects of deep cryogenic treatment (DCT) on the wear resistance of AISI 52100 bearing steel were investigated. For this purpose, a number of bearing steel samples were held for different times (12, 24, 36, 48, 60 h) at deep cryogenic temperatures (?145 °C). The wear experiments were carried out in a ball–disk arrangement, by applying loads of 10 and 20 N and a sliding velocity of 0.15 m/s. After conducting the experimental studies, 36 h was found to be the optimal holding time. At this holding time, the wear rate and friction coefficient were decreased, while the hardness reached to maximum values. It was observed that DCT led to significant microstructural changes, which resulted in improved tribological properties. 相似文献
5.
A. Kubilay S. Zimmermann I. Zinovik B. Michel 《Numerical Heat Transfer, Part A: Applications》2013,63(11):815-835
This article presents a compact computational model for the rapid determination of the junction temperature of a chip cooled with a heat sink, exploring the concept of hot water cooled electronics as a strategy to reduce the carbon footprint of data centers. The model aims at rapid simulations of variations of the chip, as well as the heat sink outlet water temperatures during transient heat loads. The model is validated by experimental tests with a water-cooled manifold microchannel (MMC) heat sink, which is designed to cool the processors of state-of-the-art servers. The chip temperature is determined subject to periodic heat loads as large as 100 W with frequencies in the range from 1 to 10 Hz. The results show that to calculate 1 s of real temperature variation requires less than 20 s of computational time on a Quad-Core AMD Opteron 2350, 2 GHz desktop PC with 4 GB RAM. The thermal response of the heat sink to real-time power traces with durations up to 200 s is modeled for different flow rates. The simulations indicate that application of a flow-control feedback loop could achieve more than 50% reduction in water flow rate, without compromising the maximal chip temperatures. 相似文献
6.
Kubilay Aslantas Irfan Ucun 《The International Journal of Advanced Manufacturing Technology》2009,41(7-8):642-650
In this study, the machinability of austempered ductile iron (ADI) having a ferritic structure was examined. For this purpose, three types of ductile iron materials (as cast, ADI-250, ADI-375) and two different types of cutting tool materials (ceramics and cermet) were used. To emphasize the role of austempering process, ductile iron (DI) specimens are first austenitized in salt bath at 900°C for 120 minutes after which they are quenched in salt bath at 250°C (ADI-250) and 375°C (ADI-375) for 120 min. Machining tests were carried out at various cutting speeds (100–500 m/min) under the constant depth of cut and feed rate. The performance of both ceramic and cermet tools were evaluated based on the workpiece surface roughness and flank wear. Wear conditions of the cutting tools were characterized by scanning electron microscope. The results point out that the lower austempering temperature results in increasing of the cutting forces, while better surface roughness is obtained. Additionally, the results indicate that the tool wear occurs mainly on the flank face. However, higher cutting speed results in chipping formation in cermet cutting tool. 相似文献
7.
Lanlin Zhang Gokhan Mumcu Salih Yarga Kubilay Sertel John L. Volakis Henk Verweij 《Journal of Materials Science》2008,43(5):1505-1509
New magneto-photonic assembly designs for high-gain antennas require dielectrics with a significant anisotropy and low loss at GHz frequencies. This paper describes an approach to fabricate such dielectrics from ceramic laminates. These laminates consist of two ceramics with largely different permittivities and low dielectric losses. Alternating layers of commercially available α-Al2O3 and Nd-doped BaTiO3 were laminated using organic adhesives. Equivalent permittivity tensors and loss tangents were characterized using a resonant cavity-based approach, which was coupled with a finite-element method full-wave solver. Measured permittivity values were in good agreement with mean field predictions; a minimum loss tangent 1.1 × 10?3 was obtained when using one-component epoxy (Loctite®-3982) adhesive. Application of two-component epoxy (M-bond 610) adhesive results in a slightly higher loss but better mechanical properties and machinability. These laminates were used to demonstrate high gain in a prototype antenna with 6 misaligned anisotropic dielectric layers. 相似文献
8.
As a more convenient and less costly alternative to electron spin resonance (ESR) and nonspecific nitroblue tetrazolium (NBT) and cytochrome c assays of superoxide radical (SR, O(2)(?-)) detection, a novel probe, tert-butylhydroquinone (TBHQ), is introduced for SR nonenzymatically generated in the phenazine methosulfate-β-nicotinamide adenine dinucleotide (PMS-NADH) system. SR attacks both TBHQ and SR scavengers incubated in solution for 30 min where scavengers compete with TBHQ for the O(2)(?-) produced. TBHQ, but not its O(2)(?-) oxidation product, tert-butyl-1,4-benzoquinone (TBBQ), is responsive to the CUPRAC (cupric reducing antioxidant capacity) spectrophotometric assay. The CUPRAC absorbance of the ethyl acetate extract of the incubation solution arising from the reduction of Cu(II)-neocuproine reagent by the remaining TBHQ was higher in the presence of O(2)(?-) scavengers (due to less conversion to TBBQ), the difference being correlated to the SR scavenging activity (SRSA) of the analytes. With the use of this reaction, a kinetic approach was adopted to assess the SRSA of amino acids, vitamins, and plasma and thiol antioxidants. This assay, applicable to small-molecule antioxidants and tissue homogenates, proved to be efficient for cysteine, uric acid, and bilirubin, for which the widely used NBT test is nonresponsive. Thus, conventional problems of NBT assay arising from formazan insolubility and direct reduction of NBT by tested scavengers were overcome. 相似文献
9.
This study addresses the determination of the burst pressures (BP) and burst failure locations of vehicle liquefied petroleum gas (LPG) fuel tanks using both experimental and finite element analysis (FEA). The experimental burst test investigations were carried out by hydrostatic test in which the cylinders were internally pressurized with water. Two nonlinear FEA models, plane and shell, were developed and evaluated under non-uniform and axisymmetric boundary conditions. The required drawn shell properties including weld zone and shell thickness variations were investigated. The FEA BP and the burst failure locations are compared to the experimental ones. The permanent volume expansions of the LPG tanks due to internal pressure were also examined based on the code regulations. 相似文献
10.
Gries R Khaskin G Daroogheh H Mart C Karadag S Er MK Britton R Gries G 《Journal of chemical ecology》2006,32(12):2667-2677
The sex pheromone of the pistachio twig borer, Kermania pistaciella (Lepidoptera: Oinophilidae), one of the most important insect pests of pistachio, Pistacia vera, in Turkey and Iran, was identified. In gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric
analyses of pheromone gland extracts of female K. pistaciella from Turkey, (2S,12Z)-2-acetoxy-12-heptadecene was identified as the major candidate pheromone component. In field experiments in Turkey, lures
containing synthetic (2S,12Z)-2-acetoxy-12-heptadecene attracted large numbers of male moths. Its attractiveness was significantly reduced by the presence
of the R-enantiomer or of either enantiomer of the corresponding alcohol. (2S,12Z)-2-Acetoxy-12-heptadecene is the first pheromone component identified in the Oinophilidae and the first secondary acetate
pheromone component identified in the Lepidoptera.
An erratum to this article can be found at 相似文献