首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   98篇
  免费   22篇
综合类   1篇
化学工业   36篇
金属工艺   1篇
建筑科学   1篇
能源动力   2篇
轻工业   74篇
无线电   1篇
冶金工业   2篇
原子能技术   1篇
自动化技术   1篇
  2024年   2篇
  2023年   6篇
  2022年   5篇
  2021年   4篇
  2020年   6篇
  2019年   1篇
  2018年   8篇
  2017年   2篇
  2016年   4篇
  2015年   1篇
  2014年   5篇
  2013年   4篇
  2012年   5篇
  2011年   1篇
  2010年   2篇
  2008年   3篇
  2007年   1篇
  2006年   2篇
  2005年   4篇
  2004年   5篇
  2002年   4篇
  2001年   2篇
  2000年   4篇
  1999年   5篇
  1998年   4篇
  1997年   3篇
  1996年   1篇
  1995年   3篇
  1994年   5篇
  1993年   5篇
  1992年   3篇
  1991年   2篇
  1990年   2篇
  1989年   1篇
  1987年   1篇
  1986年   3篇
  1984年   1篇
排序方式: 共有120条查询结果,搜索用时 0 毫秒
61.
Fatty acid profiles with emphasis on linoleic, linolenic, oleic, and conjugated linoleic acid (CLA) were compared in milk from dairy cows fed diets containing 3.25% supplemental fat and a control diet containing no supplemented fat. The fat was supplied by either whole ground solin, flax, or canola oilseed. Solin (linola) is a new cultivar of flax that contains 28% linoleic acid in the seed, Twelve multiparous Holstein cows were assigned to one of four dietary treatments. The experimental design was a 4 x 4 Latin square with each period consisting of 16 d for adjustment to the diet followed by a 5-d sampling period. Feed intake, milk yield, milk fat yield, and milk fat percentage were not affected by treatment. Adding solin, flax, or canola oilseed to lactation diets produced the highest proportions of linoleic (C18:2), linolenic (C18:3), and oleic (C18:1) acids, respectively, in the lipid fraction of the milk of the cows consuming these diets. The proportions of C6:0 to C16:1 were depressed in the milk fat of cows fed the oilseed diets, compared with the control diet. Increasing the lactation diet levels of C18:2, by using different oilseeds, increased CLA to 1.5% of milk fatty acids. The content of CLA in milk fatty acids, however, did not increase with the solin-supplemented diet compared with the canola-supplemented diet even though the C18:2 level was higher in the former diet.  相似文献   
62.
The objective of this study was to evaluate different durations of whole raw soybeans (WS) supplementation during the prepartum period on nutrient digestibility, milk yield and composition, energy balance, blood metabolites, and oocyte and embryo quality of transition cows. Thirty-one Holstein cows were used in a completely randomized design and assigned to 4 experimental groups (G): G90, G60, G30, and G0 (control), supplemented with a diet containing 12% of WS from 90, 60, 30, and 0 d relative to the calving date, respectively. Cows were dried off 60 d before the expected calving date. After parturition, all cows were fed a diet containing 12% of WS until 84 DIM. Blood samples were collected on d ?49, ?35, ?21, ?14, ?7, 0, 7, 14, 21, 35, and 70 relative to partum. Ovum pick-ups were performed on d 21 ± 3, 42 ± 7, 63 ± 7, and 84 ± 7 of lactation. Different durations of WS supplementation did not affect DMI and apparent total-tract digestibility in either the pre- or postpartum periods. Duration of WS supplementation had no effect on milk yield and composition nor energy balance of cows. However, the duration of WS supplementation had several effects on milk fatty acid (FA) profile of cows, including a linear decrease in concentrations of cis-9 C18:1, unsaturated C18, total monounsaturated, and unsaturated FA. Further, the milk contents of cis-9,cis-12 C18:2 FA, cis-9,trans-11 C18:2 FA, and total polyunsaturated FA were increased when WS were fed to cows from 30 d but not from 60 or 90 d of the expected calving date. The length of WS supplementation in the prepartum period linearly increased blood cholesterol concentration of cows during the prepartum period, but it had no effect on blood glucose and nonesterified FA concentrations in the pre- and postpartum periods. Duration of WS supplementation during the prepartum period increased the average number of grade 2 oocytes, notably in G60, but it had no effect on embryo production and cleavage proportion of early-lactation cows. The duration of WS supplementation in the prepartum period had no effect on milk yield and energy balance of the subsequent lactation, but it altered milk FA profile in early lactation by decreasing unsaturated FA content, notably when starting to supplement WS at 90 and 60 d from the expected calving date. Our results also showed that the duration of WS supplementation during the prepartum period does not improve oocyte quality in the subsequent lactation of cows.  相似文献   
63.
通过以油菜秸秆为基料栽培银耳,分析其对银耳鲜重、生长期、粗多糖含量及其成分构成的影响,综合评价油菜秸秆栽培银耳的可行性。结果显示:当栽培基料中油菜秸秆和棉籽壳的比例为4∶6(质量比)时,其产出银耳的鲜重可提高至430.16 g,显著性高于传统纯棉籽壳栽培(P<0.05);达到子实体成熟的时间可缩短至31.18 d,与纯棉籽壳栽培无显著性差异(P≥0.05);同时银耳粗多糖的得率高达34.76%,显著性高于纯棉籽壳栽培(P<0.05)。在银耳粗多糖成分构成方面,多糖含量、葡萄糖醛酸含量和分子量分布与常规的棉籽壳基料产出银耳无明显差异。  相似文献   
64.
Pressed cake from rapeseed (Brassica napus L.) is a promising plant protein source not yet utilised for human consumption due to the presence of antinutrients such as glucosinolates. Protein solubility is a crucial parameter influencing the functionality and thereby the applicability of proteins as food ingredients. A novel cruciferin‐rich rapeseed protein product was produced by an aqueous processing method in pilot plant scale. Intact glucosinolates were conserved by this procedure and largely removed from the protein products. Protein solubility in this product was examined when dispersed in 50 mm phosphate buffer, pH 8.0 with varying NaCl concentration (0–500 mm ). Unexpectedly, a salting‐out effect was observed of the globulin proteins, as 15.9 ± 0.6% protein was in solution at 500 mm added NaCl, whereas 21.5 ± 1.1% was solubilised without added NaCl; whether the observed effects originates from lipid and fibre constituents in the product remains to be resolved.  相似文献   
65.
建立了改进的无溶剂微波提取-全二维气相色谱/飞行时间质谱分析油菜籽和花生中挥发油的方法。使用羰基铁粉作为提取剂提取油料样品中的挥发油,实现无溶剂快速提取。经优化得到,羰基铁粉与样品的质量比为1:5;全二维气相色谱/飞行时间质谱(GC×GC/TOF MS)选择柱系统DB-5MS柱和DB-17柱,调制周期4s,初始温度35℃。将改进的无溶剂微波提取法(ISFME)与常规的无溶剂微波提取法(CSFME)进行比较。结果表明ISFME法更快捷,提取两种油料挥发油只需20min,而CSFME法需要50min;而且ISFME法能耗明显小于CSFME法。经GC×GC/TOF MS鉴定得出,两种方法提取样品挥发油的主要化学成分一致,均鉴定出大量杂环类物质、氧化挥发物(醇、醛、酮、酸、酯、烃)、含S、N物和苯环类物质等成分,其中杂环类占主要地位。ISFME法提取挥发油的氧化挥发物相对含量较多,更易于生成较多的香味物质。  相似文献   
66.
2008年在安徽省巢湖市发现一种危害冬油菜的新害虫,经初步鉴定为油菜叶露尾甲Strongyllodesvarie—gatus(Fairmaire,1891)。田间调查和试验表明:油菜叶露尾甲在安徽主要分布于巢湖市、马鞍山市、宣城市、安庆市、六安市,以及合肥市和滁州市的部分地区。该害虫在安徽年发生2代,每年3~5月及9~11月出现。3~5月是其主要的为害期和繁殖期。成虫取食油菜叶片、嫩茎和花蕾,形成“半月牙”状伤口和“秃梗”状;幼虫潜叶取食叶肉,形成不规则“亮泡”状,导致叶片枯死,提前脱落。老熟幼虫在土中化蛹、羽化;成虫入土或混在油菜种子中越夏、越冬。其在油菜上危害有加重的趋势。  相似文献   
67.
The American Oil Chemists’ Society(AOCS) is a volunteer-led association. AOCS develops and publishes methods of analysis for fats, oils, proteins, surfactants, and related materials according to accepted international standards to ensure equitable trade practices on a global scale. AOCS Official Method development has been going on for over a hundred years. The founding vision of AOCS in 1909 was "an organization designed for the development and advancement of analytical methods for cottonseed products." AOCS Official Methods are essential to world trade and are used to confirm the value of billions of pounds of oilseed-based commodities and finished products each year. In addition, AOCS conducts proficiency testing, provides certified reference materials, and collaborates with other standards developers including the International Organization for Standardization(ISO) and the Codex Alimentarius Commission. AOCS serves as a professional scientific membership organization providing current and emerging information as well as disseminating research results in oils, fats, lipids, proteins, surfactants, and related materials. Several avenues are used, especially meetings, publications, interest groups, networking opportunities, and web presence. Many scientists, experts, and others engaged in working in these fields find their professional "home" in AOCS. The AOCS Technical Leadership Committee comprises some of the most experienced AOCS members and scientists. The AOCS Technical Services department staff relies on this committee for guidance on scientific matters and for advice in prioritizing the opportunities facing AOCS.  相似文献   
68.
中国植物油料蛋白生产现状与发展趋势   总被引:10,自引:5,他引:10  
刘志同 《中国油脂》2004,29(10):5-10
对中国主要植物油料蛋白--大豆蛋白、花生蛋白、棉籽蛋白、菜籽蛋白工业的生产现状与发展趋势进行了论述,同时对这4种蛋白的氨基酸组成、营养效价和生物价进行了比较.结果表明,菜籽蛋白的生物价和营养效价最高,其次为大豆蛋白,再次为棉籽蛋白,最后为花生蛋白.目前我国对大豆蛋白开发利用最多,而对于菜籽蛋白和棉籽蛋白,由于脱毒技术等原因,开发利用不足.随着人民生活水平的提高、技术的成熟,这些油料蛋白将得到进一步的开发、利用,市场潜力巨大.  相似文献   
69.
Effect of rapeseed drying temperature on oil quality was investigated over the range 50–250°C. Total oil content was not significantly affected at 5% probability. Amounts of free fatty acids were significantly affected but remained much below the maximum permissible limit. Oil color was also significantly affected but had no specific trend of variation with temperature, and visual differentiation was difficult. Further, visual cracks and blackening were observed in rapeseeds dried at 250°C. Based on this study, elevated drying temperature up to 200°C was recommended for rapeseed without adversely affecting oil quality. This would save up to 80% drying time compared to the present practice of drying rapeseed at a maximum temperature of 93°C.  相似文献   
70.
The economics of pilot- to large-scale processing of the new oilssed cropsCrambe abyssinica, Euphorbia lagascae, andDimorphotheca pluvialis into oil, fatty acids, or esters were estimated. It was found that the processing costs forCrambe seed to oil is in the same range as that for rapeseed (≈0.5 U.S. $/kg). Production of fatty acid esters from vernolic and dimorphecolic acids requires some special downstream processing operations that result in processing costs of about 1 U.S. $/kg ester. Good-qualityDimorphotheca oil is much more difficult to obtain and requires supercritical carbon dioxide extraction. Processing costs can be as high as 4 U.S. $/kg oil.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号