全文获取类型
收费全文 | 69篇 |
免费 | 0篇 |
学科分类
工业技术 | 69篇 |
出版年
2018年 | 1篇 |
2013年 | 7篇 |
2011年 | 1篇 |
2010年 | 1篇 |
2009年 | 2篇 |
2008年 | 2篇 |
2007年 | 1篇 |
2006年 | 3篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1981年 | 3篇 |
1977年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有69条查询结果,搜索用时 250 毫秒
1.
Katsutoshi Nagaoka Kulathuiyer Seshan Kazuhiro Takanabe Ken-ichi Aika 《Catalysis Letters》2005,99(1-2):97-100
CH4/CO2 reforming over Pt/ZrO2, Pt/CeO2 and Pt/ZrO2 with CeO2 was investigated at 2 MPa. Pt/ZrO2, which shows stable activity under 0.1 MPa, and Pt/CeO2 showed gradual deactivation with time at the high pressure. The deactivation was suppressed drastically on Pt/ZrO2 with CeO2 prepared by different impregnation order (co-impregnation of Pt and CeO2 on ZrO2, and consecutive impregnation of Pt and CeO2 on ZrO2). The amount of coke deposition was found insignificant and similar among all the catalysts (including Pt/ZrO2 and Pt/CeO2). Catalytic activity after the reaction for 24 h was in agreement with Pt particle size after the reaction for same period, indicating that the difference of the catalytic stability is mainly dependent on the extent of Pt aggregation through catalyst preparation, H2 reduction, and the CH4/CO2 reforming. Pt aggregation and the amount of coke deposition were least pronounced on (Pt–Ce)/ZrO2 prepared by impregnation of CeO2 on Pt/ZrO2 and the catalyst showed highest stability. 相似文献
2.
S. Jayalakshmi S. V. Kailas S. Seshan K. Kumar T. S. Srivatsan 《Materials and Manufacturing Processes》2005,20(5):747-760
A growing impetus to enhance our understanding of the behavior of magnesium-based alloys for use in weight critical applications resulted as a consequence of the low density of magnesium. In an attempt to enhance the applicability of magnesium for a wide spectrum of performance-critical applications, the addition of reinforcement to the alloy was considered as an economically affordable and potentially viable scientific alternative. In this paper are reported the results of a study aimed at understanding the influence of saffil alumina short fiber reinforcement on microstructural development of a squeeze-cast magnesium alloy. Preliminary results confirm promise of the reinforced alloy, which retains hardness, strength, and stiffness better at elevated temperatures compared to the unreinforced counterpart. However, impact strength and toughness of the reinforced alloy are inferior. The importance of the matrix alloy in governing the overall mechanical response of the composite microstructure is discussed based on fractographic observations. The importance of volume fraction of the reinforcing phase on properties of the composite microstructure is highlighted. 相似文献
3.
Microstructure and properties of squeeze cast Cu-carbon fibre metal matrix composite 总被引:2,自引:0,他引:2
There have been reported attempts of producing Cu based MMCs employing solid phase routes. In this work, copper was reinforced with short carbon fibres by pressure infiltration (squeeze casting) of molten metal through dry-separated carbon fibres. The resulting MMC's microstructure revealed uniform distribution of fibres with minimum amount of clustering. Hardness values are considerably higher than that for the unreinforced matrix. Addition of carbon fibres has brought in strain in the crystal lattice of the matrix, resulting in higher microhardness of MMCs and improved wear resistance. Tensile strength values of MMCs at elevated temperatures are considerably higher than that of the unreinforced matrix processed under identical conditions. 相似文献
4.
The increasing need for lightweight and cost-effective materials for structural applications has resulted in significant improvements and development of new aluminum alloys for structural applications. Lithium addition to aluminum has the potential for providing a class of high strength alloys with exceptional properties suitable for weight-critical and stiffness-critical applications. Casting of aluminum-lithium alloys presents a variety of problems and high-quality ingots are not readily obtainable through conventional procedures. The reactive nature of lithium necessitates the need for inert gas treatments in order to ensure melts of acceptable quality. Exploitation of the properties of these alloys is possible only if the alloys could be cast in an open atmosphere using conventional casting techniques. This paper describes a method for casting binary and ternary aluminum-3% lithium ingots. The alloys were cast using conventional techniques in an open atmosphere under salt flux. The melting procedure and casting technique are highlighted and the intricate characteristics of the castings are discussed. The mechanical properties of the heat treated and aged castings are also examined so as to provide a basis for understanding the quality of the cast ingots. 相似文献
5.
Expression of intermediate filaments (IFs) has been suggested to be a reliable marker for differentiating epithelial and non-epithelial tumors. Moreover, the c-erbB-2 and p53 genes are considered to be involved relatively early in the process of human carcinogenesis. In order to elucidate the origin of uterine carcinosarcomas, we analyzed IF, c-erbB-2 and p53 expression in and the ultrastructural characteristics of clones derived from a human uterine-carcinosarcoma cell line, EMTOKA. The expression of IFs and other proteins in the EMTOKA clones was identical to that in the EMTOKA cell line. It and its 7 clones all expressed cytokeratins 8, 17, 18 and 19, vimentin, epithelial membrane antigen, S-100, myoglobin, type-II collagen, alpha-smooth-muscle actin, placental alkaline phosphatase and epidermal-growth-factor receptor. The c-erbB-2 and p53 expression levels of all the cell types of the EMTOKA cell line and its clones were the same. Interestingly, an ultrastructural study showed that the EMTOKA cell line and its clones at early and late passages possessed the characteristics of epithelial cell types without either transitional forms between the epithelial and stromal components or differentiation into sarcomatous components. The results of this study lend particular support to the combination tumor hypothesis that a precursor (stem) cell gives rise both to epithelial and to mesenchymal components during the histogenesis of uterine carcinosarcoma, the epithelial component of which appears to be dominant, suggesting that the established cell lines derived from a common stem cell. 相似文献
6.
K. B. Sundaram S. S. Seshan V. H. Desai S. M. Arora 《Journal of Materials Science: Materials in Electronics》1992,3(1):26-28
HighT
c superconductor materials of yttrium barium copper oxide (YBCO) have been etched by a new electrochemical technique. In this technique, acids like hydrochloric, nitric and phosphoric have been used as an electrolyte and etching has been achieved with acid dilutions as high as 1:200 with water. It is observed that rapid and controlled etching is possible by this technique. 相似文献
7.
Chandra Sekhar A. Durisety Rajagopal Vijayraghavan Lakshmipriya Seshan Syed K. Islam Benjamin J. Blalock 《Analog Integrated Circuits and Signal Processing》2006,48(2):143-150
This paper demonstrates a technique for controlling the electron emission of an array of field emitting vertically aligned
carbon nanofibers (VACNFs). An array of carbon nanofibers (CNF) is to be used as the source of electron beams for lithography
purposes. This tool is intended to replace the mask in the conventional photolithography process by controlling their charge
emission using the “Dose Control Circuitry” (DCC). The large variation in the charge emitted between CNFs grown in identical
conditions forced the controller design to be based on fixed dose rather than on fixed time. Compact digital control logic
has been designed for controlling the operation of DCC. This system has been implemented in a 0.5 μm CMOS process.
Chandra Sekhar A. Durisety received his B.E. (Hons.) Instrumentation from Birla Institute of Technology and Sciences, Pilani, India in 1997 and his
M.S in Electrical Engineering from University of Tennessee, Knoxville in 2002. Since 2003, he has been working towards his
Ph.D degree also in Electrical Engineering at Integrated Circuits and Systems Lab (ICASL), University of Tennessee, Knoxville.
He joined Wipro Infotech Ltd, Global R & D, Bangalore, India in 1997, where he designed FPGA based IPs for network routers.
Since 1999, he was involved in the PCI bridge implementation at CMOS chips Inc, Santa Clara, CA, and the test bench development
for Sony’s MP3 player, while at Toshiba America Electronic Components Inc., San Jose, CA. His research interests include multi-stage
amplifiers, data converters, circuits in SOI and Floating Gate Devices.
Rajagopal Vijayaraghavan received the B.E degree in electronics and communication engineering from Madras University in 1998 and the M.S degree in
electrical engineering from the University of Texas, Dallas in 2001.He is currently working towards the Ph.D degree in electrical
engineering at the University of Tennessee. His research interest is in the area of CMOS Analog and RF IC design. His current
research focuses on LNAs and VCOs using SOI based MESFET devices.
Lakshmipriya Seshan was born in Trivandrum, India on April 30, 1979. She received her B.tech in Electronincs & Communication Engg from Kerala
University, India in June 2000 and M.S in Electrical Engg from University of Tennessee in 2004. In 2004, she joined Intel
Corporation as an Analog Engineer, where she is engaged in the design of low power, high speed analog circuits for various
I/O interface topologies.
Syed K. Islam received his B.Sc. in Electrical and Electronic Engineering from Bangladesh University of Engineering and Technology (BUET)
and M.S. and Ph.D. in Electrical and Systems Engineering from the University of Connecticut. He is presently an Associate
Professor in the Department of Electrical and Computer Engineering at the University of Tennessee, Knoxville. Dr. Islam is
leading the research efforts of the Analog VLSI and Devices Laboratory at the University of Tennessee. His research interests
are design, modeling and fabrication of microelectronic/optoelectronic devices, molecular scale electronics and nanotechnology,
biomicroelectronics and monolithic sensors. Dr. Islam has numerous publications in technical journals and conference proceedings
in the areas of semiconductors devices and circuits.
Benjamin J. Blalock received his B.S. degree in electrical engineering from The University of Tennessee, Knoxville, in 1991 and the M.S. and
Ph.D. degrees, also in electrical engineering, from the Georgia Institute of Technology, Atlanta, in 1993 and 1996 respectively.
He is currently an Assistant Professor in the Department of Electrical and Computer Engineering at The University of Tennessee
where he directs the Integrated Circuits and Systems Laboratory (ICASL). His research focus there includes analog IC design
for extreme environments (both wide temperature and radiation immune), multi-gate transistors and circuits on SOI, body-driven
circuit techniques for ultra low-voltage analog, mixed-signal/mixed-voltage circuit design for systems-on-a-chip, and bio-microelectronics.
Dr. Blalock has co-authored over 60 published refereed papers. He has also worked as an analog IC design consultant for Cypress
Semiconductor Corp. and Concorde Microsystems Inc. 相似文献
8.
Properties of squeeze cast Mg-6Zn-3Cu alloy and its saffil alumina short fibre reinforced composites
S. Jayalakshmi Satish V. Kailas S. Seshan E. Fleury 《Journal of Materials Science》2006,41(12):3743-3752
In the present work, Mg-Zn-Cu alloy (ZC63) and its saffil alumina short fibre reinforced composites produced using the squeeze
casting technique were evaluated for their properties. The unreinforced base alloys and their composites were characterized
for their microstructure, hardness, yield strength, impact strength, wear resistance and corrosion resistance. The dependence
of the properties of composites was studied as a function of fibre volume fraction. Results showed that the composites exhibited
improved hardness, yield strength at elevated temperature and wear resistance in comparison to the monolithic alloy. However,
ductility, impact strength and corrosion resistance of the composites were inferior to that of the base alloy. The nature
of the base alloy matrix in determining the properties of the composites was discussed based on fractographic analysis. 相似文献
9.
John R. Whyte Gordon H. Geiger Krishna Seshan 《Metallurgical and Materials Transactions B》1984,15(4):617-622
Particles from the inlet, outlet, and bin of electrostatic precipitators (ESPs) operating on copper reverberatory furnace
and converter off-gas streams were characterized by their chemical, mineral-ogical, morphological, and electrical properties.
Reverberatory furnace particles, nominally less than 10 microns in size, are believed to be formed by condensation of PbSO4 and ZnSO4 onto oxide particles (Fe3O4, Cu2O, SiO2) originating in the slag or concentrate. The very fine particles from the dual-nature converter dust were similar in characteristics
and probably in origin to the reverberatory furnace particles. The coarse (up to 500 microns) slag (Fe3O4, SiO2) and matte (Cu2S, Cu) particles in the converter samples probably arose from entrainment by flowing or bubbling gases. The properties of
all three sample portions varied depending on the source of the sample and the effectiveness of electrostatic precipitation.
University of Arizona 相似文献
10.
The promoting effect of niobium in a Li/MgO catalyst for the oxidative coupling of methane (OCM) and for the oxidative dehydrogenation of ethane (ODHE) has been studied in some detail. It has been found that a Li/Nb/MgO catalyst with 16 wt % niobium showed the highest activity for the C2 production in the OCM reaction; the activity at 600 °C was ten times that of the Li/MgO catalyst at the same temperature. The Li/Nb/MgO catalyst was also slightly more active for the ODHE reaction than was the Li/MgO catalyst. However, the Li/Nb/MgO catalyst produced considerably more carbon dioxide in the both reactions. Structural investigation of the catalyst showed that the addition of niobium to the Li/MgO catalyst increased the surface area and gave an increase in the lithium content of the calcined catalysts. Two niobium phases, LiNbO3 and Li3NbO4, were formed; it is shown that the first of these probably causes the increased activity. Ageing experiments showed that the activity of the catalyst was lost if the catalyst was used above 720 °C, the melting point of the lithium carbonate phase. The catalyst showed a decrease of surface area after ageing and a sharp decrease of the amount of the two niobium phases. The addition of carbon dioxide to the feed could not prevent the deactivation of the Li/Nb/MgO catalyst. 相似文献