全文获取类型
收费全文 | 697篇 |
免费 | 16篇 |
国内免费 | 14篇 |
专业分类
电工技术 | 12篇 |
综合类 | 21篇 |
化学工业 | 66篇 |
金属工艺 | 15篇 |
机械仪表 | 89篇 |
建筑科学 | 30篇 |
矿业工程 | 6篇 |
能源动力 | 10篇 |
轻工业 | 248篇 |
水利工程 | 12篇 |
石油天然气 | 8篇 |
无线电 | 28篇 |
一般工业技术 | 69篇 |
冶金工业 | 26篇 |
原子能技术 | 5篇 |
自动化技术 | 82篇 |
出版年
2021年 | 5篇 |
2019年 | 7篇 |
2017年 | 6篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 87篇 |
2012年 | 16篇 |
2011年 | 17篇 |
2010年 | 15篇 |
2009年 | 29篇 |
2008年 | 28篇 |
2007年 | 32篇 |
2006年 | 34篇 |
2005年 | 32篇 |
2004年 | 25篇 |
2003年 | 25篇 |
2002年 | 12篇 |
2001年 | 13篇 |
2000年 | 12篇 |
1999年 | 10篇 |
1998年 | 10篇 |
1997年 | 28篇 |
1996年 | 18篇 |
1995年 | 12篇 |
1994年 | 16篇 |
1993年 | 10篇 |
1992年 | 8篇 |
1991年 | 10篇 |
1990年 | 9篇 |
1989年 | 8篇 |
1988年 | 9篇 |
1987年 | 7篇 |
1986年 | 8篇 |
1985年 | 4篇 |
1984年 | 8篇 |
1983年 | 7篇 |
1982年 | 10篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 7篇 |
1978年 | 9篇 |
1977年 | 5篇 |
1974年 | 5篇 |
1972年 | 5篇 |
1971年 | 5篇 |
1968年 | 5篇 |
1967年 | 7篇 |
1965年 | 7篇 |
1955年 | 9篇 |
1954年 | 4篇 |
排序方式: 共有727条查询结果,搜索用时 15 毫秒
1.
The prediction of six different sensory texture attributes of twenty-seven potato samples based on uniaxial compression curve features and full uniaxial compressions curves is reported. The data set comprised five varieties, sorted in dry matter bins, and sampled at two storage times. The predictions of most of the sensory texture attributes from full compression curves performed better than just using curve features. Furthermore, force-deformation curves are shown to give slightly better predictions than stress-strain curves. For most of the texture attributes better predictions were obtained using uniaxial compression data from raw potato samples as compared to cooked samples. This study is meant to open up a debate on interpreting the information in uniaxial compression curves in relation to sensory texture quality. Multivariate analysis can handle this and can further give insight about where in the curve the information relevant for the predictions of the sensory attributes is found. 相似文献
2.
3.
A cryo-specimen storage system for low-temperature scanning electron microscopy (LTSEM) specimens is described, which: liberates multi-specimen experiments from sampling restrictions imposed by the rate at which LTSEM specimens can be examined in the SEM; provides security against experiment loss resulting from breakdown of the SEM or cryo-system; enables collection of specimens in the field or in laboratories remote from the SEM laboratory; and facilitates international air transport of LTSEM specimens. The components of the system, which has a capacity of 98 stub-mounted specimens, are readily made in a laboratory workshop. The details of the design may be altered to suit particular specimen types or experimental approaches. 相似文献
4.
5.
JOHANNA C.M. JACOBS† JACQUES H. HOUBEN† TON VAN VLIET‡ PIETER S. VAN ROON† BEREND KROL† 《International Journal of Food Science & Technology》1994,29(3):321-329
A specially designed tube viscometer was used to measure apparent viscosity during flow of Bologna type sausage emulsions moving through a pipe. Emulsions varied in fat content (from 21.8 to 44.3%) and in moisture/protein ratio (from 3.7 to 5.6), and the effects of added sodium chloride, sodium diphosphate, starch and blood plasma were investigated in a 36% fat, 3.7 moisture/protein emulsion.
The shear stresses determined as a function of shear rate were fitted by a power law. Yield stress of the emulsions was negligible relative to the applied stress. However, inspection of the flow profiles indicated that considerable slip of the sausage emulsion occurred at the pipe wall. Both emulsion flow and slip contribute to overall flow behaviour, so a kind of effective viscosity is determined. Intrinsic rheological properties and wall slip will both be affected by the composition of the sausage emulsion. 相似文献
The shear stresses determined as a function of shear rate were fitted by a power law. Yield stress of the emulsions was negligible relative to the applied stress. However, inspection of the flow profiles indicated that considerable slip of the sausage emulsion occurred at the pipe wall. Both emulsion flow and slip contribute to overall flow behaviour, so a kind of effective viscosity is determined. Intrinsic rheological properties and wall slip will both be affected by the composition of the sausage emulsion. 相似文献
6.
A. VAN LOEY A. FRANSIS M. HENDRICKX G. MAESMANS J. de NORONHA P. TOBBACK 《Journal of food science》1994,59(4):828-832
Based on thermal degradation kinetics and heat transfer expressed as the Ball formula method, a simplified approach was used to optimize sterilization processes for thermal softening of white beans (Phaseolus vulgaris, subsp. nanus Metz., variety Manteca de Leon) Constant retort profiles in a still and end-over-end rotary water cascading retort (Barriquand Steriflow) were used. Quality attributes of beans processed at the optimum were evaluated by a trained taste panel and by a tenderometer. Both approaches could distinguish (P<0.01) between attributes of products from optimal rotary and still processes. End-over-end rotation resulted in faster heat penetration and better quality retention of beans. Texture of white beans processed at 4° or 8°C from the optimal temperature could be distinguished (P<0.01) by the sensory panel and by the tenderometer. 相似文献
7.
8.
ABSTRACT: In the first three decades after the Second World War in Europe millions of dwellings were built, in most cases on large estates in or near cities. At that time, many people in various kinds of household found these estates attractive and were happy to live on them. But, in the last two decades, in many parts of Europe social, economic, and physical problems have emerged and the reputation of the estates has suffered a deep decline. That is not to say that they have lost their function in the housing market: some groups might still be drawn to them—low‐income households who cannot find a decent, affordable place elsewhere, for example. In this article, we describe the current position of these estates in the housing careers of specific groups. Are there some groups who find them attractive places in which to live? Or do most people want to get away as soon as they can? Are some people “trapped”? We show that the situation differs substantially between parts of Europe, but even per estate and per household category. Our findings imply that intervention strategies with regard to these estates will have to become much more differentiated than they currently are. 相似文献
9.
Measurements were made of temperature and ternary composition for coexisting liquid and crystalline phases on the air isobar in the system Fe2 O3 -Fe3 O4 -YFeO3 with particular regard to the stability range and compositional limits of yttrium iron garnet. Phase equilibrium relations were determined by conventional quenching techniques combined with measurements of loss in weight at the reaction temperature to locate true ternary compositions. The intersection of the air isobar with the ternary univariant boundary curve for coexisting magnetite, garnet, and liquid phases results in a eutectic-type situation at the composition Y0.27 Fe1.73 O2.87 and 1469°± 2°C. A similar intersection of the isobar with the boundary curve for coexisting garnet, orthoferrite, and liquid phases gives rise to a peritectic-type reaction at 1555° 3°C. and Y0.44 Fe1.56 O2.89 The yttrium iron garnet crystallizing from liquids within these temperature and composition limits contains up to 0.5 mole % iron oxide in excess of the stoichiometric formula in terms of the starting composition 37.5 mole % Y2 O3 , 62.5 mole % Fe2 O3 . At 1470° C. the garnet phase in equilibrium with oxide liquid contains 2 mole % FeO in solid solution. The small solubility of excess of iron oxide and partial reduction of the garnet phase in air are unavoidable during equilibrium growth from the melt. 相似文献
10.
A design for a neural network chip is proposed using probabilistic bit streams to represent real values. This paper analyzes the performance of the proposed neurons in this design and demonstrates that very simple operations can be used to obtain the desired functionality. It is also shown that a suitable ‘activation function’ for neurons of this type can be obtained using the interaction of two probability distributions. Finally, the paper introduces a variant of the back-propagation learning algorithm which involves computing the derivatives of the output with respect to individual weights in a network of such units. 相似文献