全文获取类型
收费全文 | 4957588篇 |
免费 | 323292篇 |
国内免费 | 193715篇 |
专业分类
电工技术 | 267879篇 |
技术理论 | 144篇 |
综合类 | 274276篇 |
化学工业 | 722951篇 |
金属工艺 | 236026篇 |
机械仪表 | 264150篇 |
建筑科学 | 283670篇 |
矿业工程 | 117238篇 |
能源动力 | 137746篇 |
轻工业 | 408152篇 |
水利工程 | 102377篇 |
石油天然气 | 151880篇 |
武器工业 | 36687篇 |
无线电 | 531339篇 |
一般工业技术 | 601283篇 |
冶金工业 | 575947篇 |
原子能技术 | 64837篇 |
自动化技术 | 698013篇 |
出版年
2024年 | 14880篇 |
2023年 | 46254篇 |
2022年 | 108313篇 |
2021年 | 147804篇 |
2020年 | 108817篇 |
2019年 | 89642篇 |
2018年 | 107346篇 |
2017年 | 120085篇 |
2016年 | 110225篇 |
2015年 | 131260篇 |
2014年 | 177583篇 |
2013年 | 278534篇 |
2012年 | 286227篇 |
2011年 | 324383篇 |
2010年 | 290506篇 |
2009年 | 289818篇 |
2008年 | 295830篇 |
2007年 | 287137篇 |
2006年 | 262141篇 |
2005年 | 220225篇 |
2004年 | 159242篇 |
2003年 | 124816篇 |
2002年 | 117308篇 |
2001年 | 106919篇 |
2000年 | 103486篇 |
1999年 | 88484篇 |
1998年 | 149387篇 |
1997年 | 107019篇 |
1996年 | 89597篇 |
1995年 | 70352篇 |
1994年 | 61010篇 |
1993年 | 53410篇 |
1992年 | 36305篇 |
1991年 | 32414篇 |
1990年 | 31614篇 |
1989年 | 30500篇 |
1988年 | 28094篇 |
1987年 | 25042篇 |
1986年 | 24163篇 |
1985年 | 25762篇 |
1984年 | 22316篇 |
1983年 | 20444篇 |
1982年 | 19284篇 |
1981年 | 19629篇 |
1980年 | 18834篇 |
1979年 | 16858篇 |
1978年 | 16304篇 |
1977年 | 22943篇 |
1976年 | 33802篇 |
1975年 | 14164篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
针对基站柜式空调耗电量大的问题,创造性地使用基站分布式冷却的方式,达到精确送风,节能高效的目的.在应用实践中检验了分布式冷却系统实际节能量和应用效果,总结出分布式冷却系统应用场景和范围,为更大范围推广应用DCS分布式冷却系统提供实践依据. 相似文献
102.
103.
104.
105.
106.
Angiotensin I‐converting enzyme inhibitory and Ca‐binding activities of peptides prepared from tuna cooking juice and spleen proteases 下载免费PDF全文
Jirawadee Kasiwut Wirote Youravong Pittaya Adulyatham Nualpun Sirinupong 《International Journal of Food Science & Technology》2015,50(2):389-395
Tuna cooking juice is a by‐product from the tuna canning industry. In this study, tuna cooking juice was hydrolysed by proteases extracted from the spleen. Tuna cooking juice showed the highest ACE inhibitory and Ca‐binding activities after hydrolysis for 270 and 180 min, respectively. The hydrolysate was further fractionated by ultrafiltration. The permeate exhibited highest ACE inhibitory and Ca‐binding activities when passed through 1 and 5 kDa cut‐off membranes, respectively. Gel filtration chromatography was used to determine the MW of bioactive peptides that exhibited highest ACE inhibitory and Ca‐binding activities. Those peptides that exhibited highest ACE inhibitory and Ca‐binding activities were the MW range of 238–829 Da and 1355–1880 Da, respectively. These results suggest that the tuna cooking juice and the spleen protease extract are a potential source of bioactive peptides that can be utilised as bioactive ingredients in functional food and nutraceuticals. 相似文献
107.
108.
109.
The development of a sustainable energy system throughout an enterprise is a complex task, which requires an agile holistic approach. Such an approach needs to include a variety of objectives including energy strategy formation and strategic decision-making, which are directly related to the analysis and management of the main areas of sustainable development:The economic, technological, environmental, and social. These multidimensional requirements of sustainability are often difficult to achieve within the enterprise, because these aspects are interrelated and influenced by various internal and external environment factors. This paper first reviews the main challenges for an energy system, and then demonstrates how a strategic agile enterprise architecture driven approach could effectively guide the sustainable energy system development. The study presented in this paper provides a holistic approach that contributes to the advancement and usage of literature dealing with issues of sustainable energy system development and agile enterprise architecture, which has not been discussed before to any great extent. 相似文献
110.
Cheese fortification using saturated monoglyceride self‐assembly structures as carrier of omega‐3 fatty acids 下载免费PDF全文
Sonia Calligaris Alexandra Ignat Marialuisa Biasutti Nadia Innocente Maria Cristina Nicoli 《International Journal of Food Science & Technology》2015,50(9):2129-2134
The purpose of this research was to study the capacity of emulsions containing saturated monoglyceride self‐assembly structures to deliver omega‐3 fatty acids in fresh soft cheese. To this aim, fortified emulsions containing different ratios of milk, saturated monoglycerides (MGs) and cod liver oil were added to milk before cheese‐making. These emulsions were characterised by distinct microstructural features observed by polarised light microscopy and apparent viscosity values. The omega‐3 delivery performance of MG emulsions highlighted that this strategy allowed a good retention of the omega‐3‐rich oil in the curd (up to 75%). The fortified cheeses showed yield value and fat content higher than those of control samples. The enriched cheese showed hardness and cohesiveness obtained by texture profile analysis similar to those of the unfortified product. Only a slight decrease in gumminess was detected in fortified cheese. 相似文献