全文获取类型
收费全文 | 561篇 |
免费 | 3篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 129篇 |
金属工艺 | 8篇 |
机械仪表 | 14篇 |
建筑科学 | 13篇 |
能源动力 | 4篇 |
轻工业 | 270篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 5篇 |
一般工业技术 | 43篇 |
冶金工业 | 28篇 |
自动化技术 | 47篇 |
出版年
2018年 | 6篇 |
2013年 | 86篇 |
2012年 | 7篇 |
2011年 | 10篇 |
2009年 | 5篇 |
2008年 | 8篇 |
2007年 | 9篇 |
2006年 | 8篇 |
2005年 | 7篇 |
2002年 | 9篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 9篇 |
1998年 | 5篇 |
1997年 | 22篇 |
1995年 | 12篇 |
1994年 | 10篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 10篇 |
1989年 | 5篇 |
1988年 | 10篇 |
1987年 | 18篇 |
1986年 | 12篇 |
1985年 | 8篇 |
1984年 | 10篇 |
1983年 | 12篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 11篇 |
1979年 | 8篇 |
1978年 | 9篇 |
1977年 | 9篇 |
1976年 | 8篇 |
1975年 | 11篇 |
1974年 | 7篇 |
1973年 | 6篇 |
1972年 | 5篇 |
1971年 | 6篇 |
1970年 | 9篇 |
1968年 | 22篇 |
1967年 | 21篇 |
1966年 | 7篇 |
1965年 | 6篇 |
1963年 | 4篇 |
1962年 | 5篇 |
1959年 | 6篇 |
1956年 | 4篇 |
1955年 | 4篇 |
排序方式: 共有565条查询结果,搜索用时 312 毫秒
91.
A mixed-integer programming (MIP) problem is formulated to address the flexible manufacturing system (FMS) batching, loading, and tool configuration problems concurrently. This model results in a great many variables, making its mathematical solution impractical. We introduce a four-pass approach using submodels of the original MIP problem. The approach assumes that the need for batching is primarily that of tool magazine capacity constraints, with balancing and maximizing flexibility as secondary objectives. 相似文献
92.
GUOJIAN LIU CHARLES B. TEBBUTT ROBERT DURAN FRANK W. CHAMBERS 《Particulate Science and Technology》2013,31(3):279-291
ABSTRACT Previous flow visualizations and laser Doppler anemometer velocity measurements have shown that clean engine air filters are presented with very non-uniform velocity distributions when tested in the SAE universal panel Filter test housing. Experiments were conducted to measure the changes that occur in the velocity distribution in the plane 12.7 mm upstream of the filter as it is loaded with dust. Laser Doppler anemometer measurements of velocity profiles were performed for a production engine air Filter in the SAE universal panel filter test housing. Test conditions corresponded to a clean Filter, and dust-loaded Filters at additional pressure drops corresponding to 50 percent, 100 percent, and 150 percent of the design terminating pressure value. The results show that dust loading does make the velocity profiles less non-uniform, but that the changes are not dramatic. The inlet velocity profiles for the design capacity Filter remain very non-uniform. 相似文献
93.
94.
CHARLES L. GRIFFITH 《Journal of food science》1985,50(5):1333-1337
A split-split unit experiment was conducted and analyzed to determine the specific heat, thermal conductivity, density, and thermal diffusivity of Mexican corn-based tortillas dough (MCTD) as a function of processing time, temperature, and moisture content (wb). The data indicated that thermal conductivity and thermal diffusivity were significantly influenced by processing time, and respective components of temperature and moisture content. Specific heat and density varied with levels of moisture content and temperature. Thermal conductivity, specific heat, density, and thermal diffusivity could each be predicted separately by a polynomial equation. 相似文献
95.
CONRAD P. LYFORD WILLIS KIDD PATRICIA RAYAS‐DUARTE CHARLES DEYOE 《Journal of food quality》2005,28(3):279-288
Flour extraction rate is a key determinant in milling efficiency and profitability and can be useful in projecting flour output from a mill. Wheat is generally purchased based upon a small group of traditionally measured physical characteristics. This article explores the use of the Single Kernel Characterization System (SKCS) to predict flour extraction rate. Regression analysis was performed using the SKCS parameters and test weight against flour extraction rate for over 600 observations from multiple years from the hard red winter wheat production areas of the U.S. The regression equation had an R2of 0.81. The data suggest that the SKCS 4100 and test weight can be used to predict flour extraction rate in hard red winter wheat. Using the regression equation as a tool, mill buyers may be able to make better decisions regarding their wheat purchases and prediction of flour output. 相似文献
96.
A Kinetic Approach to Food Quality Prediction Using Full-History Time-Temperature Indicators 总被引:2,自引:0,他引:2
A mathematical model based on the theory of chemical kinetics was derived to predict food quality change from the response of a full-history time-temperature indicator. A first-order kinetic reaction (n = 1) was used to describe both indicator response and changes in food quality. A storage investigation of mature green tomatoes showed that the quality prediction model satisfactorily predicted changes in tomato firmness induced by variable temperature storage. Tomato firmness as predicted from the response of a LifeLines model 57 time-temperature indicator was not significantly different from the observed changes (F = 1.99, p = 0.18) for 28 days of storage. The mathematical derivation was extended to develop a quality-based interpretation of the shelf life of perishable foods. 相似文献
97.
The quality of a new variety of apple, ‘Jonagored’, after peeling and cutting was evaluated during ten days of storage in air at 4C. The objective was to evaluate the shelf-life of apple cubes by detecting the limiting parameter and to test the influence of different chemical dips on the cut apple quality with the aim of extending shelf-life. Color, i.e. browning at the cut surface, was found to be the critical quality parameter determining the shelf-life of the cut apple to less than three days. There were no significant differences between the dip treatments in measurements of CIE values. When apple cubes were treated with ascorbic acid, ascorbic acid plus calcium chloride or ascorbic acid plus calcium chloride and citric acid, the 0.75% ascorbic acid dip was found to be the most effective preservation treatment in terms of reducing color change of the cut surface. Both 0.75% ascorbic acid and 0.75% ascorbic acid plus 0.75% calcium chloride inhibited the loss of firmness of apple cubes. When citric acid was added to the dip treatment, there were color changes similar to those of the control. 相似文献
98.
CHARLES R. BARMORE JAMES F. FISHER PAUL J. FELLERS RUSSELL L. ROUSEFF 《Journal of food science》1986,51(2):415-416
Treatment of commercial grapefruit juice with Florisil (activated magnesium silicate) simultaneously reduced the content of citric acid and the bitter compounds limonin and naringin. Ascorbic acid concentration and °Brix (total soluble solids) were not altered by the Florisil treatment. Experienced taste panelists were able to differentiate between the nontreated and Florisil-treated juice on the basis of bitterness and tartness (acidity). The panelists indicated a preference for the Florisil-treated juice. 相似文献
99.
KONG-HWAN KIM HENRY G. SCHWARTZBERG JOHN R. ROSENAU 《Journal of food process engineering》1983,7(1):37-62
Concentrated CaCl2 and LiCl brines were used to evaporatively concentrate liquid foods. The concentration was carried out in double falling film evaporators in which brine flowed down the outside of the tubes and liquid food flowed down the inside. The vapor spaces between the brine and the food were connected and vapor from the food was absorbed in the brine. The heat generated by vapor absorption in the brine provided the heat needed to sustain evaporation, and was transferred to the food because of the boiling point elevation of the brine. Evaporation rates approaching those obtained in commercial evaporators were obtained for skim milk, sugar solutions and orange juice. The evaporation rates were affected by flow rates, temperature, concentration and tube material. 相似文献
100.
Two independent experiments were conducted to examine the effects of initial packaging/product conditions and storage conditions on in-package headspace pressure changes for modified atmosphere packaged beef during 12 hr storage. Headspace-to-meat volume ratio 1.8 to 5.9, surface area 200--800 cm2, sample volume 0.22–0.75L, storage at 3–13°C and initial gas composition 20–100% CO2 balanced with N2 were studied. Headspace-to-meat volume ratio was the most important packaging parameter, but surface area and meat volume also affected headspace CO2 changes. Decreased storage temperature reduced CO2 concentration remaining in headspace. Higher initial CO2 concentration resulted in greater concentration changes. 相似文献