全文获取类型
收费全文 | 232篇 |
免费 | 11篇 |
国内免费 | 33篇 |
专业分类
林业 | 23篇 |
农学 | 12篇 |
基础科学 | 6篇 |
43篇 | |
综合类 | 88篇 |
农作物 | 31篇 |
水产渔业 | 10篇 |
畜牧兽医 | 55篇 |
园艺 | 4篇 |
植物保护 | 4篇 |
出版年
2024年 | 1篇 |
2023年 | 5篇 |
2022年 | 5篇 |
2021年 | 3篇 |
2020年 | 8篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2017年 | 13篇 |
2016年 | 8篇 |
2015年 | 13篇 |
2014年 | 16篇 |
2013年 | 14篇 |
2012年 | 15篇 |
2011年 | 20篇 |
2010年 | 15篇 |
2009年 | 12篇 |
2008年 | 9篇 |
2007年 | 18篇 |
2006年 | 14篇 |
2005年 | 7篇 |
2004年 | 4篇 |
2003年 | 8篇 |
2002年 | 6篇 |
2001年 | 3篇 |
2000年 | 6篇 |
1999年 | 1篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 6篇 |
排序方式: 共有276条查询结果,搜索用时 921 毫秒
51.
52.
Elizabeth A. Clubbs Elena Vittadini Thomas H. Shellhammer Yael Vodovotz 《Journal of Cereal Science》2008
Corn tortillas have a short shelf life due to increased firmness and microbial spoilage. Commercial corn tortillas use carboxymethyl cellulose (CMC) to delay staling; however this gum is expensive when compared to the rest of the tortilla ingredients. Glycerol has been added to bread and wheat tortillas to increase pliability and salt has been shown to mask the flavor of glycerol in corn tortillas. The possibility to reduce staling in corn tortillas by adding glycerol/salt as an alternative to CMC was investigated by monitoring changes in physico-chemical properties during 2 weeks of storage at 25 °C. Molecular and macroscopic changes were followed using thermal and mechanical analysis. During storage an increase in amylopectin recrystallization was observed in all samples. The “freezable” water content of all tortillas decreased over the first 3–5 days of storage with an increase after 7 days, while moisture content and water activity remained constant. Glycerol/salt tortillas exhibited a sharper transition region in the DMA temperature scan suggesting a more homogenous sample. CMC tortillas were significantly stiffer than glycerol tortillas after 14 days of storage. Glycerol/salt combinations may offer at least a partial replacement for CMC since it helped control the stiffness, water homogeneity and distribution during storage. 相似文献
53.
Polyelectrolyte titration of whisky 总被引:1,自引:0,他引:1
Hiroo Tanaka Tomomi Tsukada Hideaki Ichiura Hiroyuki Wariishi 《Journal of Wood Science》2000,46(2):172-174
Polyelectrolyte titration using a fluorescent indicator was applied to determine the electrolytic charges in 10 whiskies at various pH levels. Tannic acid was also titrated to compare the relation between pH and charge because the polyelectrolytes in whisky were postulated to be polyphenols, mainly tannic acid, which are gradually extracted from a wood cask over the years. Below pH 7, the pH-charge curves for whisky were analogous to those for tannic acid, indicating that carboxyl groups in tannic acid were fairly stable on maturation of the whisky. The charge of the tannic acid increased with increasing pH, whereas that of whisky had a tendency to level off. The degree of leveling off was higher for whiskies with longer maturation. These phenomena are believed to be due to the oxidation of pyrogallol and catechol moieties in tannic acid, which occurs during storage of the whisky. There was a clear tendency for the whiskies with higher prices to have higher charges, that is, a higher tannic acid content. 相似文献
54.
依据GB 5009.44—2016《食品安全国家标准 食品中氯化物的测定》,对特殊医学用途婴儿配方食品中氯的检测方法适用性展开研究。结果表明:采用GB 5009.44—2016第三法(银量法)检测特殊医学用途婴儿配方食品中乳蛋白部分水解配方、乳蛋白深度水解配方、氨基酸配方得到的样品加标回收率分别为95%~108%、98%~125%、100%~106%,相对标准偏差为12.7%~32.9%;采用GB 5009.44—2016第一法(电位滴定法)得到的检测结果低于第三法检测结果。 相似文献
55.
为加强兽药检验检测机构能力建设,进一步提升检测技术水平,组织开展了全国省级兽药检验机构磺胺间甲氧嘧啶钠注射液含量测定的能力比对。依据《中国兽药典》2020年版一部附录0701电位滴定法与永停滴定法以及中国合格评定国家认可委员会(CNAS)规定的程序进行本次能力比对。分别采用单因子方差分析法和Ss≤0.3σ准则对测试样品进行均匀性检验,采用t检验方法和■准则对样品进行稳定性考察,采用Z比分数评价各参加实验室的测试结果。参加本次能力比对的36家兽药检测实验室中,33家结果为满意,满意率91.7%。 相似文献
56.
57.
58.
将植物叶片在80℃下烘干,粉碎,蒸馏水浸提,用自动电位漓定法测定浸提液氯含量,添加回收率大于88%,变异系数小于5%,标准偏差在0.01~0.09之间,与浸提一佛尔哈德法测定比较,其结果一致。该法具有操作简便,干扰小,重现性好的优点。可用于研究氯气污染与植物关系的测定。 相似文献
59.
Zhiqian Lyu Bingbing Huang Zhongchao Li Zhenyu Wang Yifan Chen Shuai Zhang Changhua Lai 《Animal Science Journal》2019,90(1):98-107
The objectives of this experiment were to (a) determine the effects of fiber increase in diets on heat production (HP), (b) determine the net energy (NE) of oat bran (OB), wheat bran (WB), and palm kernel expellers (PKE) fed to growing pigs using indirect calorimetry (IC). Twenty‐four growing barrows (29.2 ± 2.6 kg) were randomly allotted to one of four diets with six replicate pigs per diet. Diets included a corn‐soybean meal basal diet and three test diets containing 30% OB, WB or PKE, respectively. During each period, pigs were individually housed in metabolism crates for 20 days, including 14 days to adapt to the diets. On day (d) 15, pigs were transferred to the open‐circuit respiration chambers for determination of daily total HP and were fed one of the four diets at 2.3MJ ME/kg body weight (BW)0.6/day. Total feces and urine were collected for the determination of digestible energy (DE) and metabolizable energy (ME) and daily total HP was measured from d 15 to d 19 and fasted on day 20 for the measurement of fasting heat production (FHP). The apparent total tract digestibility (ATTD) of dry matter (DM), gross energy (GE), and organic matter (OM) were greater (p < 0.01) in pigs fed the basal diet compared with those fed the test diets. The ATTD of neutral detergent fiber (NDF) was lower (p < 0.01) in pigs fed the WB diet compared with those fed the basal, OB, or PKE diets. The ATTD of ether extract (EE) in pigs fed the PKE diet was greater (p < 0.01) compared with those fed the other diets. The average total HP and FHP in pigs fed the four diets were 1261 and 787 kJ/kg BW0.6/d, respectively, and were not significantly affected by diet characteristics. The NE:ME ratio for diets ranged from 78.1 to 80.9%. The NE contents of OB, WB, and PKE were 10.93, 7.47, and 8.71 MJ/kg DM, respectively. 相似文献
60.
Zhenyu Wang Yifan Chen Jian Ding Hu Liu Zhiqian Lyu Wenxuan Dong Zijie Wang Shuai Zhang Fenglai Wang 《Animal Science Journal》2019,90(8):939-947
The present study was conducted to determine the net energy (NE) values and energy efficiency of wheat bran (WB), sugar beet pulp (SBP), corn gluten feed (CGF), soybean hulls (SBH), and defatted rice bran (DFRB) fed to pregnant sows. Thirty‐six multiparous pregnant sows were randomly assigned to six dietary treatments with six replicates per treatment. Each period lasted for 21 days including 14 days for adaptation. On day 15, sows were moved into respiration chambers for heat production (HP) measurement and provided feed at 544 kJ/kg BW0.75/day. On day 20, sows were fasted to measure the fasting heat production (FHP). Experimental diets included corn‐soybean meal basal diet and five diets containing 29.20% WB, SBP, CGF, SBH, and DFRB, respectively. Results showed that inclusion of WB, SBP, CGF, SBH, and DFRB to basal diet decreased (p < 0.05) the apparent total tract digestibility of energy and nutrients. The average adjusted total HP and FHP were 418 kJ/kg BW0.75/day and 326 kJ/kg BW0.75/day, respectively. The average NE:ME ratio of experiment diets was 82.5%. In conclusion, the NE values of WB, SBP, CGF, SBH, and DFRB were 9.05, 8.59, 8.37, 7.64, and 7.93 MJ/kg DM, respectively. 相似文献