全文获取类型
收费全文 | 830篇 |
免费 | 46篇 |
国内免费 | 10篇 |
专业分类
电工技术 | 10篇 |
综合类 | 1篇 |
化学工业 | 215篇 |
金属工艺 | 10篇 |
机械仪表 | 14篇 |
建筑科学 | 14篇 |
矿业工程 | 1篇 |
能源动力 | 40篇 |
轻工业 | 71篇 |
水利工程 | 6篇 |
石油天然气 | 1篇 |
无线电 | 125篇 |
一般工业技术 | 188篇 |
冶金工业 | 25篇 |
原子能技术 | 6篇 |
自动化技术 | 159篇 |
出版年
2024年 | 3篇 |
2023年 | 12篇 |
2022年 | 35篇 |
2021年 | 53篇 |
2020年 | 45篇 |
2019年 | 50篇 |
2018年 | 51篇 |
2017年 | 45篇 |
2016年 | 37篇 |
2015年 | 28篇 |
2014年 | 38篇 |
2013年 | 67篇 |
2012年 | 51篇 |
2011年 | 77篇 |
2010年 | 40篇 |
2009年 | 38篇 |
2008年 | 37篇 |
2007年 | 34篇 |
2006年 | 22篇 |
2005年 | 19篇 |
2004年 | 11篇 |
2003年 | 13篇 |
2002年 | 12篇 |
2001年 | 5篇 |
2000年 | 9篇 |
1999年 | 3篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 7篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 7篇 |
1992年 | 8篇 |
1991年 | 8篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
排序方式: 共有886条查询结果,搜索用时 15 毫秒
81.
Khetan Shevkani Narpinder Singh Sandeep Singh Arvind Kumar Ahlawat Anju Mahendru Singh 《International Journal of Food Science & Technology》2011,46(12):2584-2590
Starches from nine Indian wheat lines were evaluated to study the relationships between physicochemical and rheological properties. Large granules (>15 μm) were present in the highest proportion followed by medium (5–15 μm) and small granules (<5 μm). Amylose content ranged between 27.4 and 37.2%. Starch with the highest proportion of large granules (68.9%) showed higher values of G′peak (576 Pa) and G′final (432 Pa). Amylose content showed positive relationships with retrogradation, gel firmness, gumminess and adhesiveness while negative with springiness. Cooked starch pastes with the highest amylose content (37.2%) had higher ΔHret (0.88 J g?1), G′ret (361 Pa), adhesiveness (1.48 Ns), firmness (0.45 N) gumminess (0.22 N) and the lowest springiness (0.88). Amylose–lipid complex (AML) dissociation showed negative relations with swelling power, G′peak, G′breakdown and breakdown viscosity (r = ?0.779, ?0.66, ?0.771 & ?0.775, respectively, P < 0.05) while positive relationship with pasting temperature (r = 0.775, P < 0.05). 相似文献
82.
Sandeep Rawat Harish Andola Lalit Giri Praveen Dhyani Arun Jugran 《International Journal of Food Properties》2013,16(3):703-712
Three Himalayan medicinal plants (Habenaria intermedia, H. edgeworthii, and Roscoea procera), widely used in vitality strengthening Ayurvedic formulations in India, were assessed for nutritional phytochemical constituents, and antioxidant activity. These target species emerged as a good source of minerals and possessed important micro elements. Individually, H. intermedia contained a high content of total phenols, thiamins, tannins, and calcium; R. procera was rich in potassium and iron content; and H. edgeworthii emerged as a good source of sodium. While various antioxidant assays provided evidences on the antioxidant potential of target species, greater antioxidant potential of H. intermedia as compared to the other two species was revealing. This study, therefore, highlighted the possibilities of harnessing nutritional and antioxidant potential of these species. 相似文献
83.
The water absorption behavior and durability of extruded wood polypropylene composite (WPC) material used in Z-section sheet piles was investigated. An experimental technique to determine percentage water absorption and its effect on mechanical properties was implemented. Water absorption tests were carried out on specimens cut from flanges and webs of the Z-section by immersion in tap water at 21, 45 and 70 °C. Freeze–thaw resistance of saturated composites was studied by cycling temperatures in the range of 21 to ?29 °C. The absorption behavior followed the kinetics of a Fickian diffusion process. This behavior was modeled using an analytical solution based on Fick’s second law of diffusion. Quasi-static bending tests were conducted periodically on specimens immersed in water to assess degradation in flexural properties. A significant decrease in mechanical properties of the water-saturated specimens compared to the dry control was observed. Degradation of flexural modulus was found to be a strong function of water absorption with initial decrement as percentage water absorption increased and finally stabilized as the absorption process approached saturation. However, freeze–thaw cycling did not have any significant effect on mechanical properties of saturated composites. A phenomenological model for moisture intrusion and its effect on mechanical properties was implemented and applied to explain the experimental findings. 相似文献
84.
Thermally-stimulated spontaneous currents from metal-iodine doped polyvinyl pyrrolidone-metal system
A study of the spontaneous response currents from the metal-iodine doped polyvinyl pyrrolidone-metal (MPM) systems, on thermal
stimulation at a constant rate, has been made with similar (Al-Al, Ag-Ag and Au-Au) and dissimilar (Al-Cu/Ag/Ni/PbZn) electrode
systems. Thermograms of spontaneous current emission of iodine-doped PVP films exhibit two maxima around 90 ± 10°C and 130–160°C
in the first heating run, whereas with the second heating run a single peak is found around 140–170°C. The magnitude and direction
of current depend on the choice and combination of electrode materials. The position of the current peak in the thermal spectrum
shifts with different heating run. A temperature dependence of open-circuit voltage (OCV) is also reported and it was found
that OCV varied linearly with the difference in electrode work functions. The active centres of PVP are the carbonyl group
of double-bond tertiary nitrogen atom (> N-C=O), and thus the charge transfer complexes are formed with iodine in PVP. The
spontaneously-generated current is discussed in terms of weak complex formation with the water molecules and the liberation
of different types of charges. 相似文献
85.
P. Sandeep S. Chandan A. K. Chaturvedi 《Wireless Communications, IEEE Transactions on》2007,6(2):473-477
Using the approximate Fourier series technique we obtain expressions for the probability of error for bandlimited BPSK signalling in the presence of timing errors and fading. The derived results can be used to compute the error probabilities to any desired accuracy for Nakagami-m and Weibull fading channels. The effect of timing error on the performance of the raised cosine pulse has been evaluated for several fading parameters. We also compare the performance of some useful Nyquist pulses known 相似文献
86.
H. Scott Hinton Roberto Gonzalez Laura L. Tedder Sandeep Karandikar Harpreet Behl Paul C. Smith John Wilbanks James Humphrey Murray Gordon Michael Lightner 《工程教育杂志》2001,90(4):513-518
This paper describes a technology‐enhanced learning environment for an undergraduate course on Optical Fiber Communications ( http:ctle.colorado.edunsf2000 ). 相似文献
87.
88.
Neeraj Dilbaghi Harmanmeet Kaur Munish Ahuja Pooja Arora Sandeep Kumar 《Journal of Experimental Nanoscience》2014,9(10):1015-1025
Nanotechnology is currently employed as a tool to fight more efficiently against human pathogens. Nanoparticles can be prepared from a variety of materials such as protein, biodegradable polymers and synthetic polymers. Tamarindus indica Linn. or tamarind is one of the most important biodegradable polymer. In the present study, chemically modified polymer of tamarind ‘carboxymethyl tamarind kernel polysaccharide’ (CMTKP) is used for the synthesis of nanoparticulate formulation. Antibacterial activity of CMTKP was analysed which was then enhanced by incorporating a flouroquinolone antibiotic, ciprofloxacin to it. Ciprofloxacin-loaded CMTKP nanoparticles were synthesised via ionotropic gelation technique. Nanosuspension so formed was lyophilised by addition of a cryoprotectant. Nanoparticles obtained were characterised for its particle size, morphology and stability. Interaction studies were confirmed by Fourier transform infrared spectroscopy (FT-IR). Antibacterial activities of ciprofloxacin, CMTKP and ciprofloxacin-loaded CMTKP nanoparticles were tested against two Gram negative and positive bacteria. The antibacterial assay results revealed greatest zone of inhibition by ciprofloxacin-loaded CMTKP nanoparticles in Micrococcus luteus. Toxicity analysis of the prepared formulation was carried out on vero cell lines via resazurin assay which revealed its minimum toxicity. 相似文献
89.
Thermo-mechanical properties and erosion performance of short carbon fibre reinforced vinyl ester resin based isotropic polymer composites with four different fibre weight fractions have been investigated. The storage, loss and damping characteristics were analysed to assess the energy absorption/viscous recoverable energy dissipation and reinforcement efficiency of the composites as a function of fibre content in the temperature range of 0–140 °C. The composite with 30 wt.% of short carbon fibres has been observed to exhibit superior thermo-mechanical response with highest energy dissipation/damping ability accompanied with a constant storage modulus without any substantial decay till 60 °C. The erosion rates (Er) of these composites are evaluated at different impingement angles (30–90°), fibre loadings (20–50 wt.%), impact velocities (43–76 m/s), stand-off distances (55–85 mm) and erodent sizes (250–600 μm) following the erosion test schedule in an air jet type test rig. An optimal parameter combination is determined and subsequently validated for erosion rate minimization following Taguchi method and by conducting confirmation experiments. A correlation between the loss-modulus inverse and the erosion rate has been observed which conceptually establishes a possible mechanistic equivalence between erosion and dynamic mechanical loading modes. The morphologies of eroded surface are examined by the scanning electron microscopy to investigate the nature of wear-craters, material damage mode and other qualitative attributes responsible for promoting erosion. 相似文献
90.
Swapnil Doijad S.B. Barbuddhe Sandeep Garg Sushanta Kalekar Jenney Rodrigues Dilecta D’Costa S. Bhosle Trinad Chakraborty 《Food Control》2011,22(12):1900-1904
The presence of Listeria in three milk processing environments as a potential source of milk contamination was assessed. Swab samples (n = 210) taken from milk processing plants were examined. Sample sites included the milk processing equipment, besides areas handling raw and pasteurized milk. The USDA Listeria-selective enrichment procedure was used to process the samples. Forty one (19.52%) Listeria isolates were recovered. The isolates were further subjected to biochemical and genotypic characterization. Out of 41 isolates, 16 (7.62%) were confirmed as Listeria monocytogenes, 2 (0.95%) as L. ivanovii, 19 (9.05%) as L. innocua. 1 (0.48%) as L. seeligeri and 3 (1.43%) as L. grayi. All the L. monocytogenes isolates were positive for the hlyA gene. PCR based serotyping revealed all L. monocytogenes to be of 1/2a, 1/2c, 3a and 3c serovar group. AscI and ApaI restriction analysis yielded four PFGE clusters for 16 L. monocytogenes isolates obtained from raw milk collector, milk silos, buttermilk mixer, cheese and other milk product processor. No predominant PFGE cluster was observed among these L. monocytogenes isolates. The main sources of L. monocytogenes were found to be raw milk collector and milk silos. In the present study L. monocytogenes was isolated from milk and milk products processing plants which could cross-contaminate the processed products and may possess a potential threat to public health. 相似文献