全文获取类型
收费全文 | 326篇 |
免费 | 17篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 63篇 |
金属工艺 | 6篇 |
机械仪表 | 16篇 |
建筑科学 | 15篇 |
能源动力 | 7篇 |
轻工业 | 10篇 |
石油天然气 | 2篇 |
无线电 | 62篇 |
一般工业技术 | 64篇 |
冶金工业 | 17篇 |
自动化技术 | 77篇 |
出版年
2023年 | 5篇 |
2022年 | 5篇 |
2021年 | 8篇 |
2020年 | 16篇 |
2019年 | 14篇 |
2018年 | 12篇 |
2017年 | 13篇 |
2016年 | 8篇 |
2015年 | 7篇 |
2014年 | 9篇 |
2013年 | 30篇 |
2012年 | 9篇 |
2011年 | 15篇 |
2010年 | 9篇 |
2009年 | 16篇 |
2008年 | 16篇 |
2007年 | 6篇 |
2006年 | 14篇 |
2005年 | 10篇 |
2004年 | 4篇 |
2003年 | 9篇 |
2002年 | 7篇 |
2001年 | 7篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1998年 | 13篇 |
1997年 | 8篇 |
1996年 | 7篇 |
1995年 | 12篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有343条查询结果,搜索用时 62 毫秒
61.
S. Sriram R. Balasubramaniam M. N. Mungole S. Bharagava R. G. Baligidad 《Bulletin of Materials Science》2005,28(6):547-554
The effect of Ce addition on the microstructure of carbon-alloyed Fe3Al-based intermetallic has been studied. Three different alloys of composition, Fe-18.5Al-3.6C, Fe-20.0Al-20C and Fe-19.2Al-3.3C-0.07Ce
(in at%), were prepared by electroslag remelting process. Their microstructures were characterized using optical and scanning
electron microscopies. Stereological methods were utilized to understand the observed microstructures. All the alloys exhibited
a typical two-phase microstructure consisting of Fe3AlC carbides in an iron aluminide matrix. In the alloy without Ce addition, large bulky carbides were equally distributed
throughout the matrix with many smaller precipitates interspersed in between. In the alloy with Ce addition, the carbide grain
sizes were finer and uniformly distributed throughout the matrix. The effect of Ce addition on the carbide morphology has
been explained based on the known effect of Ce in modifying carbide morphology in cast irons. 相似文献
62.
Sriram Ramaswamy 《Bulletin of Materials Science》1988,10(1-2):75-76
Calculations in a hydrodynamic model of quasicrystal dynamics show that dislocation motion in these systems is impeded by
a drag far greater than that in crystals. 相似文献
63.
Sriram Venkataramani Tharanikkarasu Kannan Ganga Radhakrishnan 《Polymer International》2006,55(11):1209-1214
1‐Vinylimidazole‐terminated telechelic polyurethanes were prepared from 1‐vinylimidazole and bromine‐terminated polyurethane. This vinyl‐terminated telechelic polyurethane (VTPU) and methyl methacrylate were polymerized in the presence of benzoyl peroxide to prepare novel AB crosslinked polymer networks (ABCPs). These were characterized by spectral, thermal and mechanical studies. The absence of the characteristic peak of vinyl group in infrared spectra of ABCP films confirms the occurrence of crosslinking. Static mechanical testing showed that the tensile strength of ABCP increases with increasing poly(methyl methacrylate) content. Dynamic mechanical studies revealed that ABCPs, at equal compositions of VTPU and methyl methacrylate, show good damping properties. Copyright © 2006 Society of Chemical Industry 相似文献
64.
B Sriram Shastry 《Bulletin of Materials Science》1979,1(3-4):195-199
The remarkable remanence effects observed in spin glasses are discussed. Some theoretical approaches and results are reviewed.
Invited talk given at the Indian Academy of Sciences, Bangalore, Academy discussion meeting on phase transitions, June 21st,
1978. 相似文献
65.
Sriram K. Varshney P. Shanthikumar J. 《Selected Areas in Communications, IEEE Journal on》1983,1(6):1124-1132
Discrete-time analysis of two schemes for multiplexing voice and data is presented. In each scheme voice and data are multiplexed using the movable boundary frame allocation scheme. In the first scheme, speech activity detectors (SAD's) are not used, and hence, the variations in the voice traffic are only due to the on/off characteristics of voice. In the second scheme, SAD's are employed so that talker silences can he utilized for transmission of additional voice and/or data. In this scheme, the multiplexer performs digital speech interpolation as well as movable boundary frame allocation. The performance measures considered are probability of loss for voice calls, probability of speech clipping, speech packet rejection ratio, and the expected data message delay. In the case of the multiplexer with SAD, a tradeoff exists between data message delay and speech interpolation advantage. Some numerical examples are presented which illustrate the performance of the two multiplexers. 相似文献
66.
Dynamic response of flexible-link mechanism (structure) when subjected to external dynamic load is analyzed. The non-linear equations of motion are discretized using the finite element method (FEM) and Newmark time integration method combined with Newton-Raphson iterative technique is used for solution. From the dynamic response of the structure, the required kinematic characteristics are derived. Typical examples are worked out for illustration. 相似文献
67.
Stress corrosion cracking of a commercial 0.19 pct C steel (SA-516 Grade 70) was studied in hot (92 ‡C) caustic solutions
of NaOH and NaOH plus aluminate (AlO−
2) species. Potentiostatically controlled tests were conducted near the active-passive transition, using fracture mechanics
testing techniques and fatigue precracked double cantilever beam specimens. Crack propagation rates (Ν) were determined for
a range of stress intensities (K
l). In simple NaOH solutions, Region I (K1-dependent) and Region II (K
1-independent) cracking behavior were observed. Increasing the concentration of NaOH from2m to8m decreasedK
ISCC
and displaced Region I and the onset of Region II to lowerK
1 levels. The presence of AlO−
2 produced a comparable effect, with Region II being extended to lowerK
I
-Ν levels relative to simple NaOH solutions of similar hydroxyl anion concentration. The overallK
I
-Νv behavior and fractography were consistent with a dissolution mechanism of crack advance based on the general principles of
the film rupture-dissolution model. The effect of environment composition uponK
I
— Ν behavior was attributed to changes in repassivation kinetics.
Formerly Graduate Student at the University of British Columbia 相似文献
68.
S. Sriram M. Bhaskaran A. Mitchell D. R. G. Mitchell G. Kostovski 《Nanoscale research letters》2009,4(1):29-33
We report the first instance of deposition of preferentially oriented, nanocrystalline, and nanocolumnar strontium-doped lead
zirconate titanate (PSZT) ferroelectric thin films directly on thermal silicon dioxide. No intermediate seed or activation
layers were used between PSZT and silicon dioxide. The deposited thin films have been characterised using a combination of
diffraction and microscopy techniques. 相似文献
69.
Nanotwin formation and its physical properties and effect on reliability of copper interconnects 总被引:1,自引:0,他引:1
Di Xu Vinay Sriram Jenn-Ming Yang Gery R. Stafford Inka Zienert Petra Hofmann 《Microelectronic Engineering》2008,85(10):2155-2158
Ultra-fine grained copper with a large amount of nano-scale twin boundaries has high mechanical strength and maintains normal electrical conductivity. The combination of these properties may lead to promising applications in future Si microelectronic technology, especially as interconnect material for air-gap and free-standing copper technologies. Based on first principles calculations of total energy and in-situ stress measurements, high stress followed by stress relaxation during the Cu film deposition seems to have contributed to nanotwin formation. Nanoindentation studies have shown a larger hardness for copper with a higher nanotwin density. The effect of Cu nanotwin boundaries on grain growth was investigated by scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). The presence of a high density of nanotwin boundaries may improve the reliability of Cu interconnects. 相似文献
70.
Self‐assembled centimetre‐sized rods obtained in the oxidation of o‐phenylenediamine and aniline
下载免费PDF全文
![点击此处可从《Polymer International》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Venkata Sai Sriram Mosali Graham A Bowmaker Melvin Gerard Paul A Kilmartin Jadranka Travas‐Sejdic Zoran D Zujovic 《Polymer International》2015,64(9):1135-1141
Morphologically well‐defined rods of approximately 1 cm in length are effectively and economically obtained by mixing ortho‐phenylenediamine (30 mmol L?1) with ammonium persulfate (12.5 mmol L?1) in an acidic solution (0.37 mol L?1 HCl) at room temperature with and without the presence of 50 mmol L?1 aniline. These self‐assembled, morphologically uniform products can be potentially scaled up and used as morphological templates to fabricate well‐defined structures of other materials such as conducting polymers. The products were characterized using Raman, UV‐visible, high‐resolution NMR (1H and 13C) and mass spectroscopies, X‐ray diffraction, scanning electron microscopy and elemental analysis. Apart from certain differences in visual appearance and in X‐ray diffractograms, other analytical data suggest that there are no structural changes upon addition of aniline into the reaction mixture. NMR and mass spectra imply that all syntheses carried out either with or without aniline result in a mixture of two products, attributed to 2,3‐phenazinediamine and 3‐aminophenazin‐2‐ol. A formation mechanism based on hydrogen bonding and π–π stacking has been proposed. © 2015 Society of Chemical Industry 相似文献