全文获取类型
收费全文 | 185篇 |
免费 | 14篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 66篇 |
金属工艺 | 2篇 |
机械仪表 | 12篇 |
建筑科学 | 5篇 |
能源动力 | 14篇 |
轻工业 | 26篇 |
无线电 | 17篇 |
一般工业技术 | 23篇 |
冶金工业 | 11篇 |
自动化技术 | 22篇 |
出版年
2023年 | 2篇 |
2022年 | 6篇 |
2021年 | 6篇 |
2020年 | 7篇 |
2019年 | 10篇 |
2018年 | 15篇 |
2017年 | 9篇 |
2016年 | 7篇 |
2015年 | 10篇 |
2014年 | 3篇 |
2013年 | 19篇 |
2012年 | 10篇 |
2011年 | 15篇 |
2010年 | 10篇 |
2009年 | 12篇 |
2008年 | 10篇 |
2007年 | 8篇 |
2006年 | 9篇 |
2005年 | 5篇 |
2004年 | 7篇 |
2002年 | 4篇 |
2001年 | 3篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1994年 | 1篇 |
1988年 | 1篇 |
1983年 | 1篇 |
1979年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有199条查询结果,搜索用时 15 毫秒
71.
Ali Ümit Keskin 《Analog Integrated Circuits and Signal Processing》2004,40(1):99-101
The author proposes a new, fully-integrable four quadrant analog multiplier using a current differencing buffered amplifier (CDBA), a new universal active element. The use of CDBA in fully-integrated multiplier circuit design is attractive, since it simplifies the implementation and reduces the component count while maintaining good performance. 相似文献
72.
The authors experimentally examined the effects of positive or negative affect from an out-group (O) on preferences for the 4 crossed categorization targets—in-group–in-group (ii), in-group–outgroup (io), out-group–in-group (oi), and out-group–out-group (oo)—as discussion partners. Study 1 induced affect with compliments; Study 2 used insults; Study 3 cross-culturally assessed the effects of both types of affect. Preferences for the target who possessed a category membership that matched the out-group source of affect on 1 dimension of categorization (Oi) were increased by compliments and decreased by insults. Confirming predictions, positive affect produced a hierarchical rejection pattern (ii?=?Oi?>?io?>?oo). Negative affect produced a hierarchical acceptance pattern (ii?>?io?>?Oi?=?oo). All 3 control conditions yielded an additivity pattern (ii?>?io?=?oi?>?oo). (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
73.
We present methods used to determine the linear or nonlinear static response and the linear dynamic response of an adaptive optics (AO) system. This AO system consists of a nonlinear microelectromechanical systems deformable mirror (DM), a linear tip-tilt mirror (TTM), a control computer, and a Shack-Hartmann wavefront sensor. The system is modeled using a single-input-single-output structure to determine the one-dimensional transfer function of the dynamic response of the chain of system hardware. An AO system has been shown to be able to characterize its own response without additional instrumentation. Experimentally determined models are given for a TTM and a DM. 相似文献
74.
In the present study, copper oxide (CuO) and copper (Cu) particles were characterized and investigated to observe the effects of antimicrobial activity on ceramic tile surfaces. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were used for particle characterization. A new formulation of antimicrobial glaze was achieved by the combination of two glaze compositions with different Cu and CuO content to obtain micro–nano hybrid surface morphology to provide the antibacterial property. Surface morphology of coated ceramic surfaces was examined by SEM in detail and water contact angles were measured with goniometer. The relationships between antibacterial effect, phase evolution, surface topography, and wettability of surfaces were determined. The tenorite phase of CuO was observed on both Cu- and CuO-modified surfaces. Both Cu and CuO particles in glazed ceramic surfaces showed the similar antibacterial activity against Staphylococcus aureus and Escherichia coli. The antibacterial activity was dependent on mainly tenorite phase crystallization. The amount of the tenorite phase that was slightly higher in the case of Cu-incorporated surfaces instead of CuO and hence the bactericidal effect was slightly more pronounced. Although the developed surfaces are not hydrophobic, they show antibacterial properties. 相似文献
75.
Fahrettin Gogus Mustafa Z. Ozel Hasene Keskin Derya Kocak Yanık Alastair C. Lewis 《International Journal of Food Properties》2013,16(8):1625-1634
Microwave-assisted hexane or water extraction was used to extract flavor compounds from fresh red pepper fruit and also from traditionally and industrially made pepper pastes. The composition of the volatile components from each extract was analyzed using comprehensive two-dimensional gas chromatography with time of flight mass spectrometry. In total, 79 compounds were determined including 15 alcohols, 14 terpenes, 13 aldehydes, 12 ketones, 7 fatty acids, 6 fatty acid esters, and 6 browning reaction products. The major common compounds of fresh pepper and the pastes were 2-pentanone, 3-hexanol, acetic acid, oleic acid, and linoleic acid. The compounds (E)-2-undecenal, farnesol, 2-pentadecyn-1-ol, linolenic acid, and squalene were found only in the fresh pepper samples. Browning reaction products were observed in both of the pastes. However, their concentration was much higher in the industrially made one. Microwave-assisted hexane extraction from the traditionally made pepper paste gave the highest number of volatiles. Many volatiles considered to possess pleasant aroma characteristics were observed only in the traditionally made paste. 相似文献
76.
Hakan Demir Koray Soygun Arife Dogan Selda Keskin Orhan Murat Dogan 《The Journal of Adhesion》2013,89(12):941-952
The effect of two denture cleansers (Polident® and Protefix®) on the tensile bond strength between four soft liner materials (Molloplast B®, Permaflex®, Sofreliner Tough Medium®, and GC Reline Soft®) and a conventional denture base resin was investigated. For each of the liner materials 35 test specimens were prepared according to test the requirements and assigned into seven groups (n = 5). Before tensile testing, five of the liner specimens were kept in water or soaked in two cleansing solutions during 2 and 7 d. Five other samples served as a control group subjected directly to tensile testing. The bond strength values were obtained using a universal testing machine and compared statistically. The type of failure was assessed visually. No significant difference was found between the groups for the tested conditions used (p > 0.05). The most frequent failure mode was cohesive for Molloplast and Permaflex specimens, adhesive for Sofreliner Tough Medium, and a mixed type of failure was observed for GC Reline Soft material. 相似文献
77.
Comparative analysis of thermophilic immobilized biohydrogen production using packed materials of ceramic ring and pumice stone 总被引:1,自引:0,他引:1
Tu?ba Keskin Elif Aksöyek Nuri Azbar 《International Journal of Hydrogen Energy》2011,36(23):15160-15167
Ceramic ring and pumice stone were used as a support matrix for the enhancement of biohydrogen production in immobilized cell culture systems. The reactors were continuously operated for the hydrogen fermentation using sucrose as the major carbon source at varying hydraulic retention times (HRT) as an important operational factor. In terms of volumetric hydrogen production, the best value was obtained with ceramic ring at 1.5 h HRT (2.98 l H2/l/d), on the other hand, the pumice stone packed reactor resulted in 30% less volumetric hydrogen production (2.28 l H2/l/d) at two fold longer retention time (HRT 3 h). It was demonstrated that volumetric hydrogen production with the immobilized bioreactor configurations was 6 fold better than the suspended culture bioreactor configuration (CSTR). Furthermore, up to 4 mol and 5 mol hydrogen yields per mole of sucrose used (which are 62.5% and 50% of the theoretical values) were achieved by pumice stone and ceramic ring packed reactors, respectively, whereas suspended culture system yielded only 0.5 mol H2/mol sucrose. 相似文献
78.
79.
Mustafa Keskin Un-Ku Moon Gabor C. Temes 《Analog Integrated Circuits and Signal Processing》2002,30(3):243-247
A novel pseudo-N-path switched-capacitor circuit is described. Its center frequency is insensitive to element mismatch as well as to the finite gain and bandwidth of the opamps used. In this new architecture, the charges from the input source to the output are not transferred by an opamp; rather the opamp is used only as a buffer. The performance of the circuit is superior to that of a regular pseudo-N-path structure. 相似文献
80.
The problem of low-voltage operation of switched-capacitor circuits is discussed, and several solutions based on using unity-gain-reset of the opamps are proposed. Due to the feedback structure, the opamps do not need to be switched off during the reset phase of the operation, and hence can be clocked at a high rate. A low-voltage ΔΣ modulator, incorporating pseudodifferential unity-gain-reset opamps, is described. A test chip, realized in a 0.35-μm CMOS process and clocked at 10.24 MHz, provided a dynamic range of 80 dB and a signal-to-noise+distortion (SNDR) ratio of 78 dB for a 20-kHz signal bandwidth, and a dynamic range of 74 dB and SNDR of 70 dB for a 50-kHz bandwidth, with a 1-V supply voltage 相似文献