全文获取类型
收费全文 | 689篇 |
免费 | 95篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 1篇 |
综合类 | 22篇 |
化学工业 | 106篇 |
机械仪表 | 2篇 |
建筑科学 | 47篇 |
矿业工程 | 9篇 |
能源动力 | 12篇 |
轻工业 | 461篇 |
水利工程 | 91篇 |
石油天然气 | 5篇 |
一般工业技术 | 5篇 |
冶金工业 | 2篇 |
自动化技术 | 25篇 |
出版年
2025年 | 3篇 |
2024年 | 23篇 |
2023年 | 21篇 |
2022年 | 39篇 |
2021年 | 36篇 |
2020年 | 56篇 |
2019年 | 54篇 |
2018年 | 44篇 |
2017年 | 34篇 |
2016年 | 29篇 |
2015年 | 33篇 |
2014年 | 36篇 |
2013年 | 35篇 |
2012年 | 38篇 |
2011年 | 31篇 |
2010年 | 20篇 |
2009年 | 22篇 |
2008年 | 29篇 |
2007年 | 36篇 |
2006年 | 28篇 |
2005年 | 20篇 |
2004年 | 14篇 |
2003年 | 15篇 |
2002年 | 9篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 7篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 10篇 |
1991年 | 6篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有788条查询结果,搜索用时 15 毫秒
51.
52.
超微粉碎是一种能将物料粉碎至微米级甚至纳米级的先进技术,具有节约物料、粉碎速度快和粉体粒度均匀且细的显著优势,近年来逐渐被应用在粮食作物前处理中,对生产口感好、营养物质溶出率高和功能性强的食品具有积极意义。文章总结了7种超微粉碎技术的分类及优缺点,综述了超微粉碎技术对粮食营养物质(蛋白质、淀粉、脂肪、膳食纤维和酚类物质)和特定生理功能(调节血糖、血压、血脂、抗氧化和减少有害物质)的影响,并对超微粉碎技术在粮食产业的发展方向进行了展望。 相似文献
53.
为攻克目前污泥水热产物价值相对较低、水热液过剩等问题,提出将水热液作为水热介质多次循环利用的工艺方案。通过分析污泥中氮、磷及有机质等重要资源在水热固、液相中的转化及分配规律,探究水热液循环利用在提高污泥水热产物价值、节约水资源方面的可行性和潜在优势。结果表明:水热液循环利用促进液相产物中氮、磷成分积累,在250℃水热条件下,3次循环后液相氨氮质量浓度高达17 000 mg/L,液相总磷质量浓度为200 mg/L,分别是一次水热结果的4倍和5倍,显著提升水热液的资源回收效率;水热液循环利用促进水热固相的成炭过程,有助于提高污泥水热炭化产物的利用价值。通过调控水热反应强度、增加水热液循环次数,可实现水热产物价值最大化,同时提升水资源利用效率。研究结果可为水热法实现市政污泥高效减量化、资源化利用提供理论和技术支撑。 相似文献
54.
55.
56.
57.
Job Mwamburi George Basweti Monica Owili Jared Babu Peter Wawiye 《Lakes & Reservoirs: Research and Management》2020,25(3):292-313
Many large lake ecosystems are experiencing increasing eutrophication and persistent cyanobacteria‐dominated algal blooms affecting their water quality and ecosystem productivity because of widespread non‐point and point nutrient sources. Accordingly, the present study utilized data of July 2003 and January–February 2004, as well as previous measurements of nutrients and physico‐chemical variables (electrical conductivity, dissolved oxygen, temperature, pH, turbidity and chlorophyll‐a), to characterize the spatial and temporal trends, as a means of better understanding the factors influencing lake environmental conditions, as support tools for long‐term ecosystem management and for better understanding the long‐term trends and effects. Inshore gulf areas were found to represent zones of maximum nutrient concentrations, compared to the deep main lake zones, with significant inter‐parameter correlations. Phosphorus, silicon and chlorophyll‐a concentrations were significantly correlated. Water electrical conductivity was also significantly and positively correlated with soluble reactive silicon (SRSi), alkalinity hardness DO, while exhibiting a negative association with water transparency. Water turbidity and transparency, electrical conductivity, and SRSi concentrations clearly describe a gradient from the gulf into the main lake. For such a shallow gulf, these findings suggest primary productivity is influenced mainly by the availability of nutrients, light transparency and the extent of availability of resuspended nutrients. The increasing eutrophic state of Lake Victoria is a serious concern since it contributes to an increased potential of more frequent occurrences of cyanobacterial blooms, a potential public health risk to both humans and wildlife. Improved understanding of influences from previous fish species introductions and concomitant changes in indigenous fish species, increased lake basin population and anthropogenic activities, water hyacinth resurgences, sustainability of biodiversity, and current interests in cage farming, are among the major concerns and challenges facing the contemporary Lake Victoria. The trends regarding nutrients and physico‐chemical characteristics are intended to support better monitoring efforts and data to promote the lake's ecosystem services and the sustainable management of the lake ecosystem. 相似文献
58.
研究戊糖片球菌NCU301对豆粕(未灭菌)强化发酵的最佳工艺条件,测定豆粕发酵前后营养成分和抗营养因子的变化。以乳酸菌活菌量为指标,通过单因素实验和Box-Behnken响应面分析法优化豆粕强化发酵工艺,确定最佳工艺条件为:发酵时间50.0 h、发酵温度30.0 ℃、料水比1:0.82、接种量8%,优化后活菌量达到1.15×1010 CFU/g。此外,测定豆粕发酵前后营养成分和抗营养因子变化。结果表明:与未发酵豆粕相比,强化发酵豆粕中粗蛋白、酸溶性蛋白、小肽、游离氨基酸的含量分别提高4.78%、36.04%、52.21%、19.10%,胰蛋白酶抑制剂活性和脲酶活性分别下降89.56%、91.72%;与自然发酵豆粕相比,粗蛋白、游离氨基酸总量分别提高0.6%、35.89%,酸溶性蛋白含量、小肽含量,胰蛋白酶抑制剂活性和脲酶活性分别下降4.64%、3.35%、72.79%、60%。使用戊糖片球菌作为豆粕发酵的菌种不仅可以作为抗生素替代品,还可以提高豆粕的营养价值。 相似文献
59.
Muhammad H. Alu'datt Taha Rababah Mohammad N. Alhamad Ghaid J. Al-Rabadi Carole C. Tranchant Ali Almajwal 《Critical reviews in food science and nutrition》2018,58(18):3209-3218
ABSTRACTPhenolic phytochemicals have become of interest due to their therapeutic potential, particularly with regards to their anti-cancer, anti-inflammatory, hypolipidemic, and hypoglycemic properties. An evolving area of research involving phenolics in foods and their products pertains to the functional, biological, and nutritional consequences resulting from the binding between certain phenolic compounds and the macronutrient and micronutrient constituents of foods. The goal of this review is to provide a summary of studies investigating endogenous phenolic interactions with major components in food systems, including carbohydrates, proteins, lipids, minerals and vitamins, with a focus on the phenolic compounds and nutrients in oil-bearing plants. Another major objective is to provide a comprehensive overview of the chemical nature of phenolic interactions with food constituents that could affect the quality, nutritional and functional properties of foods. Such information can assist in the discovery and optimization of specific phenolic complexes in plant-based foods that could be utilized towards various applications in the food, nutraceutical and pharmaceutical industries. 相似文献
60.
Irene Biancarosa Ikram Belghit Christian G Bruckner Nina S Liland Rune Waagbø Heidi Amlund Erik‐Jan Lock 《Journal of the science of food and agriculture》2018,98(5):2035-2042