全文获取类型
收费全文 | 215篇 |
免费 | 7篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 26篇 |
金属工艺 | 2篇 |
机械仪表 | 11篇 |
建筑科学 | 15篇 |
能源动力 | 1篇 |
轻工业 | 99篇 |
无线电 | 5篇 |
一般工业技术 | 7篇 |
冶金工业 | 4篇 |
原子能技术 | 1篇 |
自动化技术 | 50篇 |
出版年
2020年 | 3篇 |
2016年 | 2篇 |
2015年 | 4篇 |
2013年 | 50篇 |
2012年 | 3篇 |
2010年 | 5篇 |
2009年 | 6篇 |
2008年 | 2篇 |
2007年 | 3篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 12篇 |
1996年 | 10篇 |
1995年 | 5篇 |
1993年 | 8篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 7篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 6篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1968年 | 4篇 |
1967年 | 3篇 |
1965年 | 1篇 |
1964年 | 2篇 |
1963年 | 2篇 |
1960年 | 1篇 |
1955年 | 1篇 |
1954年 | 2篇 |
1936年 | 1篇 |
排序方式: 共有223条查询结果,搜索用时 15 毫秒
1.
DANIEL O. EZEALA 《Journal of Food Biochemistry》1985,9(3):249-254
The effect of fermentation on the fatty acids (FA) content and composition of cassava tuber meal has been investigated. The major FA of the cassava tuber meal (CTM) lipid were oleic and palmitic acids. Other FA found in decreasing order were linoleic, linolenic, palmitoleic, stearic, myristic, pentadecanoic, heptadecanoic and nonadecanoic acids. Fermentation of the CTM resulted in substantial increases in the absolute quantities of the individual FA detected except linolenic acid. However fermentation did not alter the pattern of composition of the FA, but it caused increases in the composition of saturated FA and decreases in certain unsaturated ones. Stearic acid increased in composition by about 92.6% and pentadecanoic by about 50%. A reduction of about 72% of the linolenic acid and 24.2% of the palmitoleic acid composition were obtained in the fermented CTM lipid. 相似文献
2.
A study of the prevalences of Salmonella, Listeria and thermophilic campylobacters in a dedicated commercial poultry feed mill was undertaken. Salmonella was frequently recovered in samples taken in the preheat and postheat treatment areas of the mill with the overall percentage of samples positive found to be 18.8% and 22.6%, respectively. Feed ingredients and dust collected in the preheat treatment locations within the mill were frequently contaminated with Salmonella (11.8% and 33.3% of samples, respectively). High prevalences of Salmonella were also detected in dust samples (24.2%) obtained from the postheat treatment area of the mill and from feed delivery vehicles (57.1%).
Listeria was also recovered from samples at pre- and postheat treatment areas within the mill with overall isolation rates of 14.1% and 18.5% observed, respectively. The most frequently observed species of Listeria recovered from samples in both areas within the mill was L. innocua, L. monocytogenes, L. grayi and L. welshimeri.
No thermophilic campylobacters were recovered from any of the samples analyzed in the current study. 相似文献
Listeria was also recovered from samples at pre- and postheat treatment areas within the mill with overall isolation rates of 14.1% and 18.5% observed, respectively. The most frequently observed species of Listeria recovered from samples in both areas within the mill was L. innocua, L. monocytogenes, L. grayi and L. welshimeri.
No thermophilic campylobacters were recovered from any of the samples analyzed in the current study. 相似文献
3.
4.
This letter describes a technique to evaluate the radiometric quality of distributed target responses extracted from Synthetic Aperture Radar (SAR) data. The approach is original in that it aims to estimate the Equivalent Number of Looks of clustered pixels, a parameter which summarizes the first order statistics of speckle. This empirical method can be applied to processed, interpolated, and even speckle-filtered, SAR images. Using ERS-1 Precision Image SAR data, it is shown, first, how to discriminate between uniform and non-uniform targets, and, then, to estimate the radiometric resolution of pixels gathered according to several clustering schemes. 相似文献
5.
Comparison of three‐dimensional analysis and stereological techniques for quantifying lithium‐ion battery electrode microstructures 下载免费PDF全文
OLUWADAMILOLA O. TAIWO DONAL P. FINEGAN DAVID S. EASTWOOD JULIE L. FIFE LEON D. BROWN JAWWAD A. DARR PETER D. LEE DANIEL J.L. BRETT PAUL R. SHEARING 《Journal of microscopy》2016,263(3):280-292
Lithium‐ion battery performance is intrinsically linked to electrode microstructure. Quantitative measurement of key structural parameters of lithium‐ion battery electrode microstructures will enable optimization as well as motivate systematic numerical studies for the improvement of battery performance. With the rapid development of 3‐D imaging techniques, quantitative assessment of 3‐D microstructures from 2‐D image sections by stereological methods appears outmoded; however, in spite of the proliferation of tomographic imaging techniques, it remains significantly easier to obtain two‐dimensional (2‐D) data sets. In this study, stereological prediction and three‐dimensional (3‐D) analysis techniques for quantitative assessment of key geometric parameters for characterizing battery electrode microstructures are examined and compared. Lithium‐ion battery electrodes were imaged using synchrotron‐based X‐ray tomographic microscopy. For each electrode sample investigated, stereological analysis was performed on reconstructed 2‐D image sections generated from tomographic imaging, whereas direct 3‐D analysis was performed on reconstructed image volumes. The analysis showed that geometric parameter estimation using 2‐D image sections is bound to be associated with ambiguity and that volume‐based 3‐D characterization of nonconvex, irregular and interconnected particles can be used to more accurately quantify spatially‐dependent parameters, such as tortuosity and pore‐phase connectivity. 相似文献
6.
7.
Abstract Analysis of Landsat Thematic Mapper (TM) image of 14 May 1984 has shown that such data can be used to survey vegetation and sediment distributions in the intertidal zone of the Wash estuary at a spatial detail comparable with current methods practised by the.Nature Conservancy Council. Multispectral classification of this TM image showed good separation of salt-marsh vegetation communities which had recently been surveyed by the Nature Conservancy Council and for which reliable training data could be taken. The sensitivity of classification performance, using both parametric and non-parametric algorithms, to apparently minor differences in phenology at training site locations demonstrates two requirements for improved salt-marsh classification. They are the need for strict definition of training data and that TM wave bands 2, 3, 4 and 5 provide suitable spectral vectors for classifying intertidal environments. 相似文献
8.
PATRICIA L. ALVES DE LIMA DANIEL A RIBEIRO MARINA M SUGUI ANA PAULA TEREZAN MARIA APARECIDA C DOMINGUES E R FILHO LUCIANA AZEVEDO DAISY M F SALVADORI LUCIA R RIBEIRO 《Journal of Food Biochemistry》2010,34(1):206-228
In this study, we have investigated the stability of the antigenotoxic properties of dried of Lentinula edodes (Berk.) Singer mushroom powder stored at room and at − 20C. Mice were pretreated by gavage for 15 consecutive days with 0.6 mL/day of an aqueous extract of dried L. edodes powder prepared at 60C. On day 15, the mice were intraperitoneally injected with 50 mg/kg N-ethyl-N-nitrosourea (ENU); 3 h later, peripheral blood was withdrawn from the animals and used to evaluate DNA damage using the comet assay. The mice were sacrificed 24 h after the ENU treatment and the bone marrow used to measure the frequency of micronucleated polychromatic erythrocytes. The results indicated that storage at both room temperature and at − 20C significantly reduced the antigenotoxic effects of the mushroom powder. In addition, whereas freshly dried mushroom powder was nongenotoxic, storage of the powder at − 20C resulted in genotoxic activity ( P < 0.05). Taken together, our data indicate that constituents of L. edodes powder are altered during storage, resulting in both genotoxicity and a reduction in antigenotoxicity. 相似文献
9.
Synthesis of LiNiO2 cathode by the combustion method 总被引:1,自引:0,他引:1
MYOUNGYOUP SONG IKHYUN KWON HUNUK KIM SUNGBO SHIM DANIEL R. MUMM 《Journal of Applied Electrochemistry》2006,36(7):801-805
To determine optimum conditions for the synthesis of LiNiO2 by the combustion method, syntheses were carried out in air and under oxygen at various calcination temperatures and for different times. The electrochemical properties of the prepared samples were then investigated. The optimum conditions are preheating at 400 °C for 30 min in air in the mole ratio of urea to nitrate 3.6 and calcination at 750 °C for 36 h under O2. The LiNiO2 synthesized under these conditions had a first discharge capacity of 189 mAh g−1 at 0.1 C-rate and relatively good cycling performance. This sample has a larger value of I
003/I
104 (smaller cation mixing) and a smaller R-factor (larger hexagonal ordering). Cycling performance was investigated in various voltage ranges. The first discharge capacity increased as the upper limit of the voltage range rose. The first discharge capacity was small but cycling performance was good when the sample was cycled in the voltage range with the lowest upper limit. 相似文献
10.
THE INFLUENCE OF AGING BEEF IN VACUUM 总被引:2,自引:0,他引:2
U.S. Choice grade beef loins and ribs were aged to determine the effect of vacuum packaging for 7 and 15 days at 32° and 40° F on sensory characteristics, microbial counts and weight loss. Vacuum packaging had no significant influence on tenderness, flavor and juiciness but produced a highly significant reduction in weight loss during aging. Surface bacterial counts were significantly less on the vacuum packaged portions than the portions not packaged. 相似文献