全文获取类型
收费全文 | 167篇 |
免费 | 9篇 |
专业分类
化学工业 | 67篇 |
金属工艺 | 3篇 |
机械仪表 | 5篇 |
建筑科学 | 1篇 |
能源动力 | 4篇 |
轻工业 | 29篇 |
无线电 | 5篇 |
一般工业技术 | 28篇 |
冶金工业 | 22篇 |
原子能技术 | 3篇 |
自动化技术 | 9篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 2篇 |
2019年 | 6篇 |
2018年 | 8篇 |
2017年 | 7篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 5篇 |
2013年 | 8篇 |
2012年 | 7篇 |
2011年 | 10篇 |
2010年 | 6篇 |
2009年 | 9篇 |
2008年 | 13篇 |
2007年 | 10篇 |
2006年 | 3篇 |
2005年 | 4篇 |
2004年 | 3篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 7篇 |
2000年 | 8篇 |
1999年 | 4篇 |
1998年 | 6篇 |
1997年 | 8篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1993年 | 3篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 1篇 |
排序方式: 共有176条查询结果,搜索用时 15 毫秒
91.
Darshan M.A. Karwat Scott W. Wagnon Margaret S. Wooldridge Charles K. Westbrook 《Combustion and Flame》2013,160(12):2693-2706
Although there have been many ignition studies of n-heptane—a primary reference fuel—few studies have provided detailed insights into the low-temperature chemistry of n-heptane through direct measurements of intermediate species formed during ignition. Such measurements provide understanding of reaction pathways that form toxic air pollutants and greenhouse gas emissions while also providing key metrics essential to the development of chemical kinetic mechanisms. This paper presents new ignition and speciation data taken at high pressure (9 atm), low temperatures (660–710 K), and a dilution of inert gases-to-molecular oxygen of 5.64 (mole basis). The detailed time-histories of 17 species, including large alkenes, aldehydes, carbon monoxide, and n-heptane were quantified using gas chromatography. A detailed chemical kinetic mechanism developed previously for oxidation of n-heptane reproduced experimentally observed ignition delay times reasonably well, but predicted levels of some important intermediate chemical species that were significantly different from measured values. Results from recent theoretical studies of low temperature hydrocarbon oxidation reaction rates were used to upgrade the chemical kinetic mechanism for n-heptane, leading to much better agreement between experimental and computed intermediate species concentrations. The implications of these results to many other hydrocarbon fuel oxidation mechanisms in the literature are discussed. 相似文献
92.
Darshan Kumar Jagdev Singh Ompal Singh Seema 《The International Journal of Advanced Manufacturing Technology》2012,61(5-8):809-826
This paper is based on the data collected from a survey of 66 Indian textile-related organizations carried out to ascertain issues related to effects of timely fulfillment of customer demand in supply chain management (SCM) practices. Using the data collected, fuzzy set theory has been applied to reach a decision regarding effects of timely fulfillment of customer demand on an organization. Four multi-input single-output (MISO) Mamdani fuzzy inference systems have been proposed as an alternative approach to handle the various variables that are normally considered in such cases in Indian textile organizations. First three MISO systems consist of four inputs (decrease in production lead time, reduction in overall cycle time, improvement in quality, betterment in process integration), three inputs (decrease in production cost, increase in profits, increase in market share), and three inputs (decrease in internal conflicts, increase in customer satisfaction, betterment in buyer–supplier relations), respectively, and give out single output each, namely production effect, monetary effect, and relation effect, respectively. These three outputs are used as inputs to the fourth MISO system to give out single output, termed as final effect. 相似文献
93.
Duraiswami Divakar Dhanagopal Manikandan Thiripuranthagan Sivakumar 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2008,83(11):1472-1478
BACKGROUND: Well‐dispersed nanoparticles of palladium were synthesized by wet impregnation technique over bentonite followed by three different reduction methods (H2 or NaBH4 or ethanol) and characterized by transmission electron microscopy, X‐ray diffraction, temperature‐programmed reduction and atomic absorption spectroscopy. Hydrogenation of citral over Pd‐supported bentonite catalysts was studied in vapor phase using a micro‐reactor. The effect of reduction method and metal loading on the conversion of citral and selectivity towards nerol and geraniol were examined. RESULTS: Among the catalysts evaluated in the vapor phase, Pd/bentonite reduced by ethanol was found to give the highest conversion and Pd/bentonite reduced by NaBH4 was found to give the highest selectivity towards nerol and geraniol. This may be attributed to the smallest particle size of Pd in the former catalyst and presence of boron species on the latter catalyst, respectively. CONCLUSION: The presence of boron in proximity to palladium particles polarized C?O bond and helped C?O adsorption, thereby yielding nerol and geraniol (the unsaturated alcohols). Copyright © 2008 Society of Chemical Industry 相似文献
94.
Channa Basappa Pramila Rao D. Narasimha Rao & Divakar 《International Journal of Food Science & Technology》1998,33(6):517-520
The binding equilibrium between β-cyclodextrin and phenolphthalein has been used to develop a method for the estimation of β-cyclodextrin in solution. From logarithmic plots of amounts of β-cyclodextrin against absorbance at 554 nm, a relation log X = (log A − log Y )/ B was found, which gave an estimate of β-cyclodextrin in the concentration range 0.0045 mg mL−1 (3.96 μm) to 4.7 mg mL−1 (4.14 mm), where X = intercept and B = slope. This method was found to be highly reproducible and reliable. 相似文献
95.
This study was conducted to determine the effects of arachidonic acid (AA) supplementation on human immune response (IR) and
on the secretion of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4). Ten healthy men (20–38 yr) participated in the study
and lived at the Metabolic Suite of the Western Human Nutrition Research Center. They were fed a basal diet (57, 27, and 16
energy percentage from carbohydrate, fat, and protein, respectively, and AA 200 mg/d) for the first 15 d of the study. Additional
AA (1.5 g/d) was added to the diet of six men from day 16 to 65, while the remaining four subjects remained on the basal diet.
The diets of the two groups were crossed-over from day 66 to 115. In vitro indices of IR were examined using blood drawn on days 15, 58, 65, 108, and 115. Influenza antibody titers were determined
in the sera prepared from blood drawn on days 92 and 115 (23 d postimmunization). AA supplementation caused significant increases
in the in vitro secretion of LTB4, and PGE2, but it did not alter the in vitro secretion of tumor necrosis factor α; interleukins 1β, 2, 6; and the receptor for interleukin 2. Nor did it change the number
of circulting lymphocytes bearing markers for specific subsets (B, T, helper, suppressor, natural killer) and the serum antibody
titers against influenza vaccine. The opposing effects of PGE2 and LTB4 may have led to the lack of change in immune functions
tested. 相似文献
96.
Pathikumar Sellappan Vikram Jayaram Atul H. Chokshi Canchi Divakar 《Journal of the American Ceramic Society》2007,90(11):3638-3641
Amorphous powders of Al2 O3 —37.5 mol% Y2 O3 (yttrium aluminum garnet (YAG)) were prepared by coprecipitation, decomposed at 800°C, and hot-pressed uniaxally at low temperature (600°C) and a moderate pressure (750 MPa). Optimum conditions yielded microstructures with only 2% porosity and partial crystallization of YAG. Further processing using high quasi-hydrostatic pressure (1 GPa) at 1000°C enabled the production of fully crystallized YAG with >96% relative density and a nanocrystalline grain size of ∼70 nm. 相似文献
97.
The present investigation calculates the surface tension and adsorption functions of the Fe-S, Fe-N, and Fe-S-N melts at 1823
K using the modified form of Butler’s equations and the derived values of the surface interaction parameters of the systems.
The calculated values are found to be in good agreement with those of the experimental data of the systems. The present analysis
indicates similar adsorption behavior of sulfur for the Fe-S and Fe-S-N systems at 1823 K. Although a linear adsorption behavior
is observed in the Fe-N system, an inverse relationship in the adsorption behavior exists between sulfur and nitrogen in the
Fe-S-N system. 相似文献
98.
This paper presents an approach to monitoring, controlling and improving the teaching process and learning outcomes in engineering courses using Statistical Quality Control (SQC). The ABET 2000 criteria and their impact on the control and improvement of teaching and learning is discussed, followed by a brief illustration of the university system that these criteria foster. It is argued that in meeting ABET 2000 goals, an engineering faculty can apply the same principles and techniques they have taught for decades; namely systems engineering and quality control. Subsequently, an SQC approach for engineering courses and their common constituents: lectures, laboratories and tutorials, is suggested. Four illustrative case studies of undergraduate mechanical and industrial engineering courses are presented. 相似文献
99.
S. SohilaM. Rajalakshmi C. MuthamizhchelvanS. Kalavathi Chanchal GhoshR. Divakar C.N. VenkiteswaranN.G. Muralidharan A.K. AroraE. Mohandas 《Materials Letters》2011,65(8):1148-1150
Tin Sulfide (SnS) nanosheets were synthesized by wet chemical route using ethylene glycol (EG) and without using any surfactant. Structural and phase purity were confirmed by powder X-ray diffraction pattern which shows the orthorhombic structure of SnS. The sheets like morphology and particle size of the synthesized product were identified by using analytical transmission electron microscope (TEM) and high resolution transmission electron microscope (HRTEM). Agglomeration of SnS nanoparticles was found to lead to the formation of nanosheets. UV-VIS-NIR absorption spectrum of SnS nanosheets shows the direct transition at 1.88 eV. Compared to bulk band gap a blue shift of 0.58 eV has been observed for direct transition. This is due to the quantum confinement effect. Room temperature photoluminescence spectrum of SnS nanosheets shows two emission bands at 1.75 and 1.57 eV respectively which are assigned to band gap and defect level transitions. 相似文献
100.
B. Manohar C. Basappa D. N. Rao S. Divakar 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1998,206(3):189-192
The effects of β-cyclodextrin (BCD) and reaction time on the recovery of cholesterol from egg yolk were studied at 25°C based
on response surface methodology. The developed response model is of the form: Y = 5.585 + 429.77 X
c + 0.534 X
t
2, where Y is the predicted cholesterol recovery (%), X
c is the BCD/egg yolk ratio (kg/kg) and X
t
is the reaction time (h). Cholesterol recovery increased with the both BCD/egg yolk ratio and reaction time and there was
no optimum value. The model predicted a cholesterol recovery of 94.5% at a BCD/egg yolk ratio of 0.163 over a reaction time
of 6 h whereas experiments showed a cholesterol recovery of 87.7%.
Received: 2 May 1997 / Revised version: 8 September 1997 相似文献