全文获取类型
收费全文 | 275篇 |
免费 | 12篇 |
学科分类
工业技术 | 287篇 |
出版年
2023年 | 3篇 |
2022年 | 6篇 |
2021年 | 15篇 |
2020年 | 3篇 |
2019年 | 9篇 |
2018年 | 6篇 |
2017年 | 12篇 |
2016年 | 5篇 |
2015年 | 8篇 |
2014年 | 10篇 |
2013年 | 19篇 |
2012年 | 9篇 |
2011年 | 14篇 |
2010年 | 10篇 |
2009年 | 12篇 |
2008年 | 9篇 |
2007年 | 15篇 |
2006年 | 16篇 |
2005年 | 11篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 8篇 |
2001年 | 4篇 |
2000年 | 6篇 |
1999年 | 11篇 |
1998年 | 8篇 |
1997年 | 7篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 6篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有287条查询结果,搜索用时 0 毫秒
1.
Steam reforming of isobutane on a 0.5% Pt–Ce0.8Gd0.2O1.9 catalyst was carried out from 300 to 700 °C under integral conditions with a gas hourly space velocity (GHSV) of 12,000 h−1. The major products were H2, CO2, CO and CH4. The other products produced were ethane, ethylene, propane and propylene with a total molar composition of less than 1.5%.
A complete conversion of isobutane was achieved at 700 °C, Kinetic data was obtained by changing the partial pressure of the
reactants and the temperature under differential conditions with a GHSV of 55,400 h−1. This was done after observing stable isobutane steam reforming for 160 h and under conditions where the mass transfer limitations
were insignificant. An empirical Langmuir–Hinshelwood type model that best fit the kinetic data available was developed. 相似文献
2.
M. J. Manohar Rao 《控制论与系统》2013,44(1):29-41
The amplitude of a postsynaptic potential attenuates as it spreads from the synapse to the trigger zone, where spike generation is initiated. Thus, especially in neurons with a large dendritic structure, great variability in synaptically evoked changes of the membrane potential at the trigger zone can be expected. Therefore the randomly distributed magnitudes of jumps caused by input processes were assumed in Stein's neuronal model with reversal potentials. Two distributions, normal and exponential, were applied for this purpose. The normal distribution has no influence on statistical characteristics of the interspike interval (1SI). For the exponential distribution the mean ISI, as well as the coefficient of variation, increases nonlinearly with the parameter of the distribution. The coefficient of variation is limited by the value 1. The estimation of the mean ISI by the method of Smith and Smith (1984) is not applicable for the investigated model. 相似文献
3.
Thrupathihalli Pandurangapp Krishna Murthy Balaraman Manohar 《International Journal of Food Science & Technology》2012,47(6):1229-1236
Curcuma amada (Mango ginger) was dried at four different power levels ranging 315–800 W to determine the effect of microwave power on moisture content, moisture ratio, drying rate, drying time and effective diffusivity. Among the fifteen thin layer drying models considered for evaluating the drying behaviour, the semi‐empirical Midilli et al., model described the drying kinetics very well with R2 > 0.999. Drying rate and effective diffusivity increased as the microwave power output increased. Activation energy was estimated by a modified Arrhenius type equation and found to be 21.6 kW kg?1. A feed‐forward artificial neural network using back‐propagation algorithm was also employed to predict the moisture content during MW drying and found adequate to predict the drying kinetics with R2 of 0.985. 相似文献
4.
Isabel C. Jaramillo Chethan K. Gaddam Randy L. Vander Wal Chung-Hsuan Huang Joseph D. Levinthal JoAnn S. Lighty 《Combustion and Flame》2014
The oxidation kinetics, under different pressures, of soot samples obtained from different liquid fuels and two standards (a commercial black carbon sample and a reference diesel soot) was studied. Soot samples were generated in a flat-flame, premixed burner under heavily-sooting conditions and captured on a water-cooled stabilization plate located above the burner surface. The collected soot was oxidized using a high-pressure thermogravimetric analyzer (HTGA). TGA operation was optimized to reduce mass transfer effects by adjusting the oxidizer flow rate and initial sample mass. Further corrections for mass transfer were accomplished by computing the effectiveness factors for intraparticle, interparticle, and external mass transfer. Two pressures were evaluated (1 and 10 atm) and O2 concentration was varied between 10 and 21%. 相似文献
5.
Finger millet seed coat is an edible material and contains good proportion of dietary fibre, minerals and phytochemicals. The seed coat matter (SCM) forms a by-product of millet milling, malting and decortication industries and can be utilised as composite flour in biscuit preparation. The SCM from native, malted and hydrothermally treated millet contained 9.5–12% protein, 2.6–3.7% fat and 40–48% dietary fibre, besides 3–5% polyphenols and 700–860 mg/100 g of calcium. The biscuits prepared using the composite flour were of crisp texture and exhibited breaking strength of 1480–1690 g compared to control biscuits (1560 g). The biscuits were of mild grey colour (ΔE = 40–50) and exhibited higher protein, dietary fibre and calcium contents. The sensory evaluation of the biscuits indicated that 10% of SCM from native and hydrothermally processed millet and 20% from malted millet could be used in composite biscuit flour. 相似文献
6.
Somashekar BR Lohith K Manohar B Divakar S 《Journal of Bioscience and Bioengineering》2007,103(2):122-128
A detailed kinetic study of the esterification of D-glucose with L-alanine catalyzed by lipases from Rhizomucor miehei (RML) and Candida rugosa (CRL) showed that both lipases follow the Ping-Pong Bi-Bi mechanism, in which L-alanine and D-glucose bind in subsequent steps releasing water and L-alanyl-D-glucose, with competitive substrate inhibition by D-glucose at higher concentrations leading to the formation of dead-end lipase.D-glucose complexes. An attempt to obtain the best fit of this kinetic model through curve fitting yielded good approximates of the apparent values of four important kinetic parameters: for RML-k(cat)=0.29+/-0.028x10(-3) M h(-1) mg(-1), K(m L-alanine)= 4.9+/-0.51x10(-3) M, K(m D-glucose)=0.21+/-0.018x10(-3) M, and K(i D-glucose)=1.76+/-0.19x10(-3) M; for CRL-k(cat)= 0.75+/-0.08x10(-3) M h(-1) mg(-1), K(m L-alanine)=56.2+/-5.7x10(-3) M, K(m D-glucose)=16.2+/-1.8x10(-3) M, and K(i D-glucose) =21.0+/-1.9x10(-3) M. 相似文献
7.
Ram Manohar Yadav Pramod Singh Dobal T. Shripathi R. S. Katiyar O. N. Srivastava 《Nanoscale research letters》2009,4(3):197-203
This investigation deals with the effect of growth temperature on the microstructure, nitrogen content, and crystallinity
of C–N nanotubes. The X-ray photoelectron spectroscopic (XPS) study reveals that the atomic percentage of nitrogen content
in nanotubes decreases with an increase in growth temperature. Transmission electron microscopic investigations indicate that
the bamboo compartment distance increases with an increase in growth temperature. The diameter of the nanotubes also increases
with increasing growth temperature. Raman modes sharpen while the normalized intensity of the defect mode decreases almost
linearly with increasing growth temperature. These changes are attributed to the reduction of defect concentration due to
an increase in crystal planar domain sizes in graphite sheets with increasing temperature. Both XPS and Raman spectral observations
indicate that the C–N nanotubes grown at lower temperatures possess higher degree of disorder and higher N incorporation. 相似文献
8.
Balaji T Acharya RN Nair AG Reddy AV Rao KS Naidu GR Manohar SB 《The Science of the total environment》2000,253(1-3):75-79
The concentrations of some elements in a few varieties of cereals and pulses are determined by Instrumental Neutron Activation Analysis using a single comparator method (k0-standardised NAA method). A total of 15 elements are measured. The method was validated by analysing the Standard Reference Material (SRM-1571) of NIST; the results are within +/-10% of the reported values for the majority of the elements. The measured concentrations of major and minor elements are analysed in terms of the average intake of mineral content and the role of these elements in terms of the nutritional value. 相似文献
9.
We report the formation and characterization of copper nanostructures, nanotubules and nanothreads, which were obtained by electrical arc evaporation of Cu electrodes under varied conditions of He ambience. Electrical arc evaporation was done with approximately 10 V and (approximately 50-100 A) DC current. The current was used in a pulse mode. The evaporated material was condensed on a formvar-coated Cu grid mounted on a liquid N2-cooled specimen holder. Transmission electron microscopy was employed to characterize the condensed materials. These investigations revealed that the condensed materials consisted of the mentioned nanostructures. Nanotubes and nanothreads are formed for a He pressure in the chamber corresponding to approximately 140 and approximately 500 torr, respectively. Extensive electron microscopic investigations showed that the diameter of the nanotubes varied from approximately 5 nm to approximately 50 nm and their length from 2 microns to 3 microns. 相似文献
10.
Balachandran P Friberg M Vanlandingham V Kozak K Manolis A Brevnov M Crowley E Bird P Goins D Furtado MR Petrauskene OV Tebbs RS Charbonneau D 《Journal of food protection》2012,75(2):347-352
Reducing the risk of Salmonella contamination in pet food is critical for both companion animals and humans, and its importance is reflected by the substantial increase in the demand for pathogen testing. Accurate and rapid detection of foodborne pathogens improves food safety, protects the public health, and benefits food producers by assuring product quality while facilitating product release in a timely manner. Traditional culture-based methods for Salmonella screening are laborious and can take 5 to 7 days to obtain definitive results. In this study, we developed two methods for the detection of low levels of Salmonella in pet food using real-time PCR: (i) detection of Salmonella in 25 g of dried pet food in less than 14 h with an automated magnetic bead-based nucleic acid extraction method and (ii) detection of Salmonella in 375 g of composite dry pet food matrix in less than 24 h with a manual centrifugation-based nucleic acid preparation method. Both methods included a preclarification step using a novel protocol that removes food matrix-associated debris and PCR inhibitors and improves the sensitivity of detection. Validation studies revealed no significant differences between the two real-time PCR methods and the standard U.S. Food and Drug Administration Bacteriological Analytical Manual (chapter 5) culture confirmation method. 相似文献