全文获取类型
收费全文 | 1004篇 |
免费 | 17篇 |
专业分类
1021篇 |
出版年
2013年 | 21篇 |
2012年 | 10篇 |
2011年 | 12篇 |
2010年 | 31篇 |
2009年 | 27篇 |
2008年 | 33篇 |
2007年 | 49篇 |
2006年 | 15篇 |
2005年 | 23篇 |
2004年 | 15篇 |
2002年 | 15篇 |
1999年 | 16篇 |
1998年 | 10篇 |
1997年 | 20篇 |
1996年 | 13篇 |
1995年 | 14篇 |
1994年 | 17篇 |
1993年 | 18篇 |
1992年 | 14篇 |
1991年 | 23篇 |
1990年 | 18篇 |
1989年 | 13篇 |
1988年 | 10篇 |
1987年 | 17篇 |
1986年 | 15篇 |
1985年 | 13篇 |
1984年 | 13篇 |
1982年 | 13篇 |
1980年 | 14篇 |
1979年 | 11篇 |
1976年 | 12篇 |
1975年 | 10篇 |
1974年 | 16篇 |
1973年 | 22篇 |
1972年 | 19篇 |
1971年 | 10篇 |
1970年 | 9篇 |
1969年 | 11篇 |
1968年 | 10篇 |
1965年 | 36篇 |
1964年 | 20篇 |
1963年 | 32篇 |
1962年 | 23篇 |
1961年 | 33篇 |
1960年 | 21篇 |
1959年 | 27篇 |
1958年 | 27篇 |
1957年 | 15篇 |
1956年 | 9篇 |
1952年 | 9篇 |
排序方式: 共有1021条查询结果,搜索用时 8 毫秒
51.
Partitioning of respiratory flow resistance in man 总被引:9,自引:0,他引:9
52.
53.
54.
55.
56.
57.
PETER L. BORDI JR. DANIELLE M. HACK SUSAN J. COCCI MICHELE D. RAGER S. WILLIAM HESSERT JR. 《Journal of sensory studies》2009,24(1):41-57
This is an initiative study on the use of trans -fat-free products in the bakery industry. A standardized doughnut product was cooked in three doughnut shortenings, one containing trans fat and two that were trans fat-free. Six hundred forty-one panelists, students, faculty and staff of a large northeastern university rated each of the three doughnuts on a variety of categories, including texture, moisture content and overall liking. Results showed that there were no significant differences between doughnuts cooked in the three shortenings – this was true for all attributes tested.
The results from this study have many significant implications for the foodservice industry, as they work to cut down or eliminate the use of trans fats in their establishments because of the significant health risks they have been proven to cause.
This study demonstrates the variances on texture, taste, appearance and overall liking characteristics of doughnuts fried in different doughnut shortenings. The nutritional breakdown of the doughnuts and the shortenings are also addressed. In the case of shortenings, the ideal type of fat is a mixture of canola, soybean and hydrogenated cottonseed. This shortening mixture, which is trans fat-free, produced the most preferred doughnut. 相似文献
The results from this study have many significant implications for the foodservice industry, as they work to cut down or eliminate the use of trans fats in their establishments because of the significant health risks they have been proven to cause.
PRACTICAL APPLICATIONS
This study demonstrates the variances on texture, taste, appearance and overall liking characteristics of doughnuts fried in different doughnut shortenings. The nutritional breakdown of the doughnuts and the shortenings are also addressed. In the case of shortenings, the ideal type of fat is a mixture of canola, soybean and hydrogenated cottonseed. This shortening mixture, which is trans fat-free, produced the most preferred doughnut. 相似文献
58.
59.
The ontogeny of strombid behavior was studied by observing thebehavior of Strombus maculatus veligers collected from the planktonand reared past metamorphosis to adults, and by observing juvenilestrombids collected in the field. Complete adult modal actionpatterns (MAP's) associated with locomotion, feeding, and rightingof overturned shells are performed by S. maculatus juvenilesimmediately after metamorphosis. There are changes in the frequencyof the use of certain MAP's which are associated with variationsin shell shape and size. The unique strombid escape response to molluscivorous gastropods(Conns spp.) is not released until juvenile S. maculatus arethree weeks past metamorphosis and two millimeters in shelllength. At that stage, the complete response is released uponthe first encounter with a predator. Experience with a predatordoes not seem to lower the age or size criteria. During ontogeny there is a trend toward an increasing complexityof behavior which is paralleled by an increasing complexityof neural structure and general morphology. There are majorsteps in the ontogeny of strombid behavior which probably coincidewith neural and morphological stages. 相似文献
60.
A Dynamic Growth Model of Vegetative Soya Bean Plants: Model Structure and Behaviour under Varying Root Temperature and Nitrogen Concentration 总被引:1,自引:0,他引:1
LIM JUNE TAEG; WILKERSON GAIL G.; RAPER C. DAVID JR; GOLD HARVEY J. 《Journal of experimental botany》1990,41(2):229-241
A differential equation model of vegetative growth of the soyabean plant (Glycine max (L.) Merrill cv. Ransom)was developed to account for plant growth in a phytotron systemunder variation of root temperature and nitrogen concentrationin nutrient solution. The model was tested by comparing modeloutputs with data from four different experiments. Model predictionsagreed fairly well with measured plant performance over a widerange of root temperatures and over a range of nitrogen concentrationsin nutrient solution between 0.5 and 10.0 mmol in the phytotron environment. Sensitivity analyses revealedthat the model was most sensitive to changes in parameters relatingto carbohydrate concentration in the plant and nitrogen uptakerate. Key words: Glycine max (L.) Merrill, dry matter, nitrogen uptake, partitioning, photosynthesis, respiration, sensitivity analysis 相似文献