全文获取类型
收费全文 | 118篇 |
免费 | 7篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 30篇 |
金属工艺 | 2篇 |
机械仪表 | 2篇 |
建筑科学 | 2篇 |
能源动力 | 6篇 |
轻工业 | 1篇 |
无线电 | 18篇 |
一般工业技术 | 47篇 |
冶金工业 | 11篇 |
自动化技术 | 5篇 |
出版年
2023年 | 4篇 |
2022年 | 2篇 |
2021年 | 8篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 9篇 |
2015年 | 6篇 |
2014年 | 3篇 |
2013年 | 6篇 |
2012年 | 8篇 |
2011年 | 8篇 |
2010年 | 4篇 |
2009年 | 2篇 |
2008年 | 3篇 |
2007年 | 6篇 |
2006年 | 2篇 |
2005年 | 5篇 |
2004年 | 11篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有127条查询结果,搜索用时 48 毫秒
1.
Traditional intumescent coatings are widely used as passive fire-protective coatings for steel structures as they are capable of expanding in the range of 20–50 times the original thickness thereby providing excellent insulation. However, the fragile nature of such residue and susceptibility to thermo-oxidation given their carbonaceous nature are key problematic issues. The concept of in situ ceramization is explored in this work as a means to form inorganic cohesive char with improved rigidity and thermo-oxidative stability. Coating samples were prepared by incorporating ammonium polyphosphate, talc, Mg(OH)2, and polydimethylsiloxane as additives into acrylic resin at different weight fractions. Thermal analysis and x-ray diffraction have confirmed the reactions between the additives to form various crystalline magnesium phosphate phases, and to a small extent, silicon phosphate, thereby ensuring the thermo-oxidative stability of the residue. This is reiterated by the fire performance tests (by exposing the coatings to a temperature profile in a furnace similar to ISO 834 fire curve). Despite the advantages of rigid char and its thermo-oxidative stability as a result of formation of inorganic phosphates, the lack of swelling has resulted in relatively poor insulation capabilities of the char, and subsequently, compromised the fire protection times (that are in the range of 45–55 min). However, pyrolysis flow combustion calorimeter results of the coatings are promising and have shown a significant drop of up to 70% in the peak of heat release rate values as compared to neat resin. 相似文献
2.
Aravind Dasari Zhong-Zhen Yu Mingshu Yang Qing-Xin Zhang Xiao-Lin Xie Yiu-Wing Mai 《Composites Science and Technology》2006,66(16):3097-3114
The primary aim of this paper is to provide an insight on the effect of the location of organoclay on the micro- and nano-scale deformation processes in melt-compounded nylon 66/organoclay/SEBS-g-MA ternary nanocomposites prepared by different blending sequences. In addition, the deformation processes of the ternary nanocomposites were compared to the binary nanocomposites (nylon 66/organoclay and nylon 66/SEBS-g-MA) and neat nylon 66. The incorporation of SEBS-g-MA particles toughened nylon 66 markedly; but the flexural modulus and strength were both reduced. Conversely, the use of organoclay increased the modulus but decreased the fracture toughness of nylon 66. Nylon 66/SEBS-g-MA/organoclay ternary nanocomposites exhibited balanced elastic stiffness and toughness. Stress-whitening studies of the fracture surfaces in terms of gray level were also performed and an attempt was made to correlate the optical reflectivity characteristics with fracture toughness. It was concluded that the capability of SEBS-g-MA particles to cavitate was decreased by the presence of organoclay in the SEBS-g-MA phase, resulting in reduced toughening efficiency. The best micro-structure for toughness and other mechanical properties is thus to maximize the amount of exfoliated organoclay in the nylon 66 matrix rather than to have it embedded in the finely dispersed SEBS-g-MA particles. 相似文献
3.
Brian A. Jalaian Xu Yuan Yi Shi Y. Thomas Hou Wenjing Lou Scott F. Midkiff Venkat Dasari 《Wireless Networks》2018,24(7):2357-2374
Recent advances in MIMO degree-of-freedom (DoF) models allowed MIMO research to penetrate the networking community. Independent from MIMO, successive interference cancellation (SIC) is a powerful physical layer technique used in multi-user detection. Based on the understanding of the strengths and weaknesses of MIMO DoF and SIC, we propose to have DoF-based interference cancellation (IC) and SIC help each other so that (i) precious DoF resources can be conserved through the use of SIC and (ii) the stringent SINR threshold criteria can be met through the use of DoF-based IC. In this paper, we develop the necessary mathematical models to realize the two ideas in a multi-hop wireless network. Together with scheduling and routing constraints, we develop a cross-layer optimization framework with joint DoF IC and SIC. By applying the framework on a throughput maximization problem, we find that SIC and DoF IC can indeed work in harmony and achieve the two ideas that we propose. 相似文献
4.
Rama Krishna Dasari V. M. Pandharipande 《Radioelectronics and Communications Systems》2016,59(10):442-448
In this paper we suggest a reconfigurable wheel antenna based on PIN diodes. The antenna is excited by a single-feed and operates in S-band and X-band. Proposed antenna’s structure is composed of two circular rings that are excited by multiple PIN diodes and microstrip lines. Antenna’s reconfiguration is realized by inserting switches into spokes and peripheral regions of a wheel antenna. The required resonance frequency is provided by combination of the structures which are controlling by PIN diodes. Developed antenna was fabricated on a RT duroid material and its pattern measurements were carried out in the outdoor environment. The measured results have demonstrated antenna’s ability to be reconfigurated and good radiation pattern characteristics within two frequency bands. 相似文献
5.
Shiro Nishiwaki Andreas Burn Stephan Buecheler Martin Muralt Snke Pilz Valerio Romano Reiner Witte Lukas Krainer Gabriel J. Spühler Ayodhya N. Tiwari 《Progress in Photovoltaics: Research and Applications》2015,23(12):1908-1915
Monolithically integrated Cu(In,Ga)Se2 mini‐modules were fabricated in order to reduce the width of patterning related dead area. The Cu(In,Ga)Se2 layers were prepared on soda‐lime glasses using the multistage process at low substrate temperature below 500 °C. A picosecond laser with a wavelength of 532 nm was used for all of the structuring processes (P1, P2, and P3) for the monolithic integration. A “lift‐off” type structuring was applied for P1 and P3, and an “ablation” type was for P2. The laser structuring was optimized to be minimizing the dead area width, and the width of about 70 µm was successfully achieved. A mini‐module, in which the optimized structuring processes were applied for the integration, demonstrated a certified efficiency of 16.6%. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
6.
Accurately measuring the viscosity of a solids suspension requires uniform suspension of the solids in the viscometer cup. In a cup‐and‐impeller viscometer system, solids may settle when the impeller speed is too low, causing viscosity measurements to appear lower than that of a well‐suspended slurry. Pre‐mixing of a solids suspension is typically performed to achieve steady state prior to measurements. Data here shows that the measured viscosity values differ depending on the pre‐mixing speed, indicating that the solids are not properly suspended at all speeds. A commonly used cup‐and‐vane impeller system can be thought of as a mixing tank that should operate above the uniform‐suspension speed (USS), although determining the USS experimentally is rather subjective. Computational fluid dynamics (CFD) is employed here to determine the USS of a pretreated corn stover (PCS) solids suspension and to confirm the experimentally measured USS. 相似文献
7.
Backman V. Gopal V. Kalashnikov M. Badizadegan K. Gurjar R. Wax A. Georgakoudi I. Mueller M. Boone C.W. Dasari R.R. Feld M.S. 《IEEE journal of selected topics in quantum electronics》2001,7(6):887-893
We present a novel instrument for imaging the angular distributions of light backscattered by biological cells and tissues. The intensities in different regions of the image are due to scatterers of different sizes. We exploit this to study scattering from particles smaller than the wavelength of light used, even when they are mixed with larger particles. We show that the scattering from subcellular structure in both normal and cancerous human cells is best fitted to inverse power-law distributions for the sizes of the scattering objects, and propose that the distribution of scattering objects may be different in normal versus cancerous cells 相似文献
8.
Wu Q Nelson WH Elliot S Sperry JF Feld M Dasari R Manoharan R 《Analytical chemistry》2000,72(13):2981-2986
Escherichia coli bacteria in the logarithmic growth phase have been investigated by UV resonance Raman spectroscopy. Bacterial whole-cell Raman spectra excited at 251 nm reflect nearly exclusively the nucleic acid composition even though a very large fraction of the bacterial mass is composed of protein. It has been demonstrated that if bacteria are grown under controlled (logarithmic growth) conditions, which give rise to organisms of known average biochemical composition, the intensities of E. coli Raman spectra can be explained quantitatively from the knowledge of component nucleic acid base resonance Raman cross sections. 相似文献
9.
Noncatalytic alcoholysis kinetics of soybean oil 总被引:1,自引:0,他引:1
Mohanprasad?A.?Dasari Michael?J.?Goff Galen?J.?SuppesEmail author 《Journal of the American Oil Chemists' Society》2003,80(2):189-192
Reaction kinetics for the alcoholysis of soybean oil with methanol, ethanol, and isopropanol were evaluated in the absence
of catalyst. Metal reactor surfaces catalyzed these reactions, so the reactions were conducted in glass capillary tubes at
120, 150, and 180°C. The reactivity of the alcohols increased with decreasing carbon number. Higher temperatures promoted
faster reactions. Higher alcohol stoichiometries did not significantly increase reaction rates; this was attributed to the
limited solubility of the alcohol in the soybean oil. At less than 20% conversion, the solubility of the alcohol in the oil
phase continuously increased, resulting in increased reaction rates. At approximately 20% conversion, the reaction systems
became homogeneous until a glycerine phase was formed at high conversions. In addition to their fundamental value, these data
provided a basis on which catalytic reactions can be investigated between 100 and 200°C. 相似文献
10.
Dasari Ayodhya M. Venkatesham A. Santoshi kumari G. Bhagavanth Reddy D. Ramakrishna 《Journal of Experimental Nanoscience》2016,11(6):418-432
A green method for the solvothermal synthesis of copper sulphide nanoparticles (CuS NPs) using xanthan gum as a capping agent was developed. The CuS NPs were characterised by scanning electron microscopy, transmission electron microscopy (TEM), X-ray diffraction, Brunauer–Emment–Teller, zeta analysis, thermal gravimetric– differential thermal analysis, Fourier transform infrared and UV–visible absorption spectra. These characterisations together determine the composition, structural, thermal and optical properties. The UV–visible spectrum had a broad absorption in the visible range. The particle size of the products was observed by TEM in the range of 8–20 nm. The photocatalytic performance of the CuS NPs was evaluated for the degradation of organic dyes (methylene blue, rhodamine B, eosin Y and congo red) under irradiation of solar, visible and UV lights. The CuS NPs showed good photocatalytic activity. Kinetic analyses indicate that the photodegradation rates of dyes usually follow pseudo-first-order kinetics for degradation mechanisms. 相似文献