全文获取类型
收费全文 | 330篇 |
免费 | 33篇 |
专业分类
电工技术 | 9篇 |
综合类 | 1篇 |
化学工业 | 75篇 |
金属工艺 | 3篇 |
机械仪表 | 15篇 |
建筑科学 | 5篇 |
能源动力 | 30篇 |
轻工业 | 113篇 |
水利工程 | 3篇 |
无线电 | 13篇 |
一般工业技术 | 38篇 |
冶金工业 | 11篇 |
原子能技术 | 5篇 |
自动化技术 | 42篇 |
出版年
2021年 | 11篇 |
2020年 | 16篇 |
2019年 | 11篇 |
2018年 | 16篇 |
2017年 | 10篇 |
2016年 | 17篇 |
2015年 | 16篇 |
2014年 | 19篇 |
2013年 | 60篇 |
2012年 | 14篇 |
2011年 | 12篇 |
2010年 | 15篇 |
2009年 | 12篇 |
2008年 | 7篇 |
2007年 | 16篇 |
2006年 | 8篇 |
2005年 | 2篇 |
2004年 | 5篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2001年 | 8篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 5篇 |
1996年 | 4篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1971年 | 3篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有363条查询结果,搜索用时 420 毫秒
51.
52.
Relative Role of Phospholipids, Triacylglycerols, and Cholesterol Esters on Malonaldehyde Formation in Fat Extracted from Chicken Meat 总被引:2,自引:0,他引:2
Fresh breast and leg meat was collected from 11-wk-old pullets fed a high protein-low fat starter ration. Lipid oxidation measured in malonaldehyde (MA) equivalents in total fat extracted from meat, and in phospholipids (PL), triacylglycerol (TG), and cholesterol ester (CE) fractions of total fat was determined by an improved TBA assay with antioxidant protection. It was found that breast meat had two-fold less fat than leg. Breast fat contained 70.1% PL, 22.2% TG, and 1.2% CE; leg fat contained 42.9% PL, 51.4% TG, and 0.8% CE. After separation by thin layer chromatography, the individual lipid classes were tested for TBA reactivity. The PL fraction was found to contribute approximately 90% of the MA measured in total fat from chicken meat. 相似文献
53.
JAN BANOUT JAROSLAV HAVLIK MICHAL KULIK PAVEL KLOUCEK BOHDAN LOJKA IRENA VALTEROVA 《Journal of food process engineering》2010,33(1):83-103
Two solar drying methods (direct cabinet solar dryer and indirect cabinet solar dryer) were tested under tropical conditions for drying aerial parts of sacha culantro ( Eryngium foetidum L.) in Pucallpa City (Peruvian Amazon). The drying behavior was monitored during all experimental runs. Dried samples and fresh leaves were hydrodistilled and isolated oils were analyzed using gas chromatography with flame ionization detector and gas chromatography-mass spectrometry. ( E )-2-dodecenal was determined as the main constituent of the sacha culantro essential oil, averaging 61.8–62.2%, followed by n -dodecanal (10.9–15.5%), ( E )-2-tetradecenal (6.7–7.6%) and 1-tetradecene (3.6–5.7%). When comparing both solar drying methods, the indirect method was found as more suitable for drying E. foetidum since the dried product resembled the fresh herb more closely in its chemicalcomposition and had better appearance. However, a better drying efficiency of 10.3% was achieved when drying in the direct solar dryer compared with 5.8% for the indirect solar dryer.
Harvested leaves of sacha culantro are widely used as a condiment in a range of Peruvian, Latin American and Caribbean foods, including vegetable and meat dishes, canned food and sauces. There is lack of any postharvest processing of this herb although it may extend possibilities for use of the herb and facilitate the product export from local production areas and might be a good economic source for poor local farmers. This study shows solar drying as a reasonable preservation technique of sacha culantro leaves which may have a practical application in case of postharvest processing of the herb in the target region of Pucallpa City in Peruvian Amazon. 相似文献
PRACTICAL APPLICATIONS
Harvested leaves of sacha culantro are widely used as a condiment in a range of Peruvian, Latin American and Caribbean foods, including vegetable and meat dishes, canned food and sauces. There is lack of any postharvest processing of this herb although it may extend possibilities for use of the herb and facilitate the product export from local production areas and might be a good economic source for poor local farmers. This study shows solar drying as a reasonable preservation technique of sacha culantro leaves which may have a practical application in case of postharvest processing of the herb in the target region of Pucallpa City in Peruvian Amazon. 相似文献
54.
风暴灾害下电力断线倒塔概率预测 总被引:1,自引:0,他引:1
提出了基于极端学习机(Extreme Learning Machine,ELM)和广义极值(Generalized Extreme Value,GEV)分布的风暴灾害下输电线路断线概率预测模型。该模型首先针对极端风速,通过ELM网络的训练学习,预测出实时变化的风速;随后从概率的角度考虑实时变化的电力线风荷载极值,提出电力线风荷载的实时广义极值分布;从而实现风暴灾害下输电线路的实时断线概率预测。结合输电线路的历史数据展开算例分析,验证了该预测方法的有效性和准确性。 相似文献
55.
56.
Katarzyna Świrk Paulina Summa Dominik Wierzbicki Monika Motak Patrick Da Costa 《International Journal of Hydrogen Energy》2021,46(34):17776-17783
A series of V-promoted hydrotalcite-derived nickel catalysts (1.0, 2.0, and 4.0 wt%) were tested in CO2 methanation. Ni–I–V2.0 with 2.0 wt% vanadium loading showed the highest catalytic activity, achieving 74.7% of CO2 conversion and 100% of CH4 selectivity at 300 °C. XRD and XANES analyses showed that the smallest Ni0 particles in Ni–I–V2.0 were consistent with the improved textural features observed for this catalyst. Moreover, CO2-TPD revealed the highest sum of weak and medium basic sites in Ni–I–V2.0 that can positively influence catalytic behavior. For the studied catalysts, a clear correlation was demonstrated between the catalytic activity and specific surface area, as well as the basic properties. 相似文献
57.
Katarzyna Tokarczyk-Dorociak Jan K. Kazak Haładyj Anna Szymon Szewrański Małgorzata Świąder 《影响评估与项目评价》2019,37(3-4):279-291
The paper presents the results of an evaluation of the effectiveness of SEA obtained as a result of a survey with the participation of stakeholders. In Poland, several hundred SEAs are conducted annually at the local and regional levels and several at the national level. Although the survey demonstrated that SEA is evaluated as effective or quite effective, the respondents pointed to several irregularities in the non-procedural dimension of effectiveness. The main ones in terms of substantive effectiveness are that SEA is rarely used to help develop plans/programmes and procedures are highly politicised. Moreover, low effectiveness in terms of variant assessment and cumulative impacts and nearly non-existent monitoring of the actual effects of implementing plans/programmes influence substantive effectiveness significantly. The respondents pointed to the problem resulting from the fact that plan-makers are unwilling to take into account the SEA recommended changes. They also emphasised that there are certain attempts to put pressure on SEA consultants to make the conclusions less stringent. Respondents indicate that in Poland the costs associated with conducting SEA often outweigh the profits. The research shows that the society is properly informed about SEA, but public involvement is still low. 相似文献
58.
59.
60.