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   261篇
  免费   0篇
  国内免费   3篇
林业   47篇
农学   27篇
  4篇
综合类   65篇
农作物   66篇
畜牧兽医   25篇
园艺   12篇
植物保护   18篇
  2020年   2篇
  2019年   2篇
  2018年   3篇
  2016年   1篇
  2015年   3篇
  2014年   8篇
  2013年   35篇
  2012年   97篇
  2011年   5篇
  2010年   13篇
  2009年   5篇
  2008年   9篇
  2007年   19篇
  2006年   9篇
  2005年   11篇
  2004年   13篇
  2003年   11篇
  2002年   3篇
  2001年   2篇
  1999年   2篇
  1998年   6篇
  1997年   2篇
  1995年   3篇
排序方式: 共有264条查询结果,搜索用时 15 毫秒
61.
四川边茶具有悠久的加工历史,是川藏地区少数民族同胞的生活必需品.综述了四川边茶加工过程中关键工序与品质成分主要变化的关系、渥堆的实质及保健功能.  相似文献   
62.
以结球甘蓝(Brassica oleracea L. var. capitata L.)E1 花粉为试材,对萌发前后的花粉总蛋白进行双向电泳及差异蛋白质谱分析,发现延伸因子 BoEF-Tu 蛋白在花粉萌发后较萌发前表达上调。利用同源克隆得到甘蓝 BoEF-Tu 基因的全长 cDNA 序列,其长度为 1 728 bp,具有一个完整开放阅读框(ORF),位于 112 ~ 1 473 bp 处,编码 453 个氨基酸残基,预测分子量为 49.17 kD,等电点为 6.52。生物信息学分析表明:BoEF-Tu 蛋白含有 9 个 α–螺旋结构,18 个 β–折叠结构,不含信号肽和跨膜区,在106 ~ 121 位氨基酸残基处有 1 个 GTP 结合区域(DKAPEEKKRGITIATA)。氨基酸同源性分析表明,BoEF-Tu 与拟南芥 EF-TuM 同源性较高,达到 93%;系统进化分析表明,BoEF-Tu 与拟南芥 EF-Tu 的亲缘关系最近。  相似文献   
63.
渥堆是形成黑茶特有品质的关键工序。本文分别从黑茶的渥堆与微生物的关系、渥堆与黑茶品质的关系、渥堆与黑茶成分变化的关系等方面进行总结,并探讨了黑茶渥堆作用中存在问题和对策,展望了黑茶渥堆在茶叶加工领域的发展前景。  相似文献   
64.
综述了近年来茶树细胞与基因工程的研究进展,包括组织培养、次生物质的生产、原生质体培养、分子标记及基因的克隆与转移等方面,并分析了在这方面今后的研究方向。  相似文献   
65.
清洁化茶厂规划   总被引:2,自引:0,他引:2  
随着社会经济的快速发展,人们生活水平不断提高,市场对茶叶卫生质量的要求越来越高,特别是珠茶产区,产品主要靠精加工后外贸出口,而国外对茶叶农药残留、细菌、灰分、粉末含量等指标控制很严,因此,传统的加工模式将严重制约茶产品外贸出口。为此,有计划、分步骤地对初制茶厂实施优化改造工作符合茶叶可持续发展的需要。  相似文献   
66.
黄茶品质形成机理研究进展   总被引:4,自引:0,他引:4  
本文从品质成分变化、微生物类群及酶活性变化、加工工艺等方面综述了黄茶品质形成机理,并展望了今后黄茶品质成因及品质化学的研究方向。  相似文献   
67.
乙烯是一种重要的植物激素,参与植物许多生理过程:本文综述了乙烯生物合成及茶树乙烯合成相关基因克隆的研究进展.为从分子水平探讨它在茶树上的生理作用提供了基础。  相似文献   
68.
四川黑茶品质化学成分的研究   总被引:14,自引:2,他引:12  
采用氨基酸自动分析法、高效液相色谱法分析了四川黑茶原料、渥堆叶、康砖成品茶的氨基酸、儿茶素组成含量及咖啡碱、茶多酚、水浸出物的含量。四川黑茶原料氨基酸含量为1424.00βmg/100g,必需氨基酸含量为547.00βmg/100g,茶氨酸含量为87.15βmg/100g,儿茶素含量为27.63βmg/g,咖啡碱、茶多酚、水浸出物含量分别为1.30%、8.18%、26.94%;渥堆叶氨基酸含量为1590.00βmg/100g,必需氨基酸含量为668.00βmg/100g,茶氨酸含量为67.62βmg/100g,儿茶素含量为27.52βmg/g,咖啡碱、茶多酚、水浸出物含量分别为1.24%、7.90%、24.53%;康砖成品茶氨基酸含量为1420.00βmg/100g,必需氨基酸含量为529.00βmg/100g,茶氨酸含量为66.88βmg/100g,儿茶素含量为13.65βmg/g,咖啡碱、茶多酚、水浸出物含量分别为1.27%、5.99%、23.92%。  相似文献   
69.
Rice appearance trait is mainly mean grain length (GL), grain width (GW), ratio of length and width (L/W), chalkiness (CH) and transparence (TR). Appearance is the first impression, and rice appearance traits effect significantly the value of commodity. Hybrid rice is relatively low quality, especially on rice appearance quality,which restricts partially its extend and badly export of hybrid seed and rice in China.Shanyou 63, the most famous hybrid rice combination of China, could not be also sustainable application because of its poor qualities. In this studies, We attempt to improve appearance quality of the elite rice maintainer of Zhenshan 97B by using molecular approach of genomic interval targeted introgression. Three F2 populations were constructed to study the classical and molecular genetic of rice appearance traits, at the same time, molecular marker-asisted toimprove the main maintainer line, Zhenshan 97B were performed. There some following results:Three F2 populations were constructed based on crosses of Guangluai 4×Jiafuzhan (GJ popu.), Minghui 86×Jiafuzhan (MJ popu.) and Zhenshan 97B×Jiafuzhan (ZJ popu.). ZJ popu and GJ popu were produced to reconstruct the linkage maps related with rice appearance traits based on BSA, and detect QTL of target traits based on IM.In ZJ popu, 9 QTLs of target traits were detected. The interval, RM169~RM516 on Chromosome 5, was genetic locus of GW, L/W, CH and BW, and the explained variances were 10.9%, 14.9%, 12.0% and 14.2%, respectively.RM214 on chromosome 7, RM339 on chromosome 8 were genetic loci if CH and BW, and the explained variances were 9.4%, 10.0%, 11.0% and 12.1%. besides there is a genetic locus, RM347, of G/W on chromosome 3, and the explained varance was 10.3%. In GJ popu, 5 QTLs of rice appearance traits were detected. The interval, RM169-RM516 on Chromosome 5, were also the genetic loci of GW, CH and BW, and the explained variances were 9.0%, 12.5%, and 13.6%, respectively. RM264~RM80 on chromosome 8 was the genetic loci of GW amd L/W,and the explained variances were 14.7% and 13.4%. The genotypes of all QTLs, except RM214, from Jiafuzhan contributed to improving riee appearance traits.The research was to improve the rice appearance quality of Zhenshan 97B by introgressing QTLs of rice appearance traits from Jiafuzhan, a donor parent, by means of MAS in the process of recurrent backcrossing, 4 SSR markers were used to detect the target genotypes from donor parent, and 70 SSR primers to identify the genetic background of recurrent parent. Consequently, there were 19 target individuals in BC3, in which the mean value of GL, GW, L/W, CH and BW were 6.06±0.04mm, 2.50±0.02mm, 2.43±0.02, 29.5±2.7 and 29.4±2.7%, respectively,and the mean homologous degree (HD) to recurrent parent is up to 98.22%. Compared to Zhenshan 97B, GL, CH and BW decreased 0.17 mm, 34.9% and 34.5% respectively and however L/W increased 0.19. which accounted separately for 25.37%, 54.79%, 54.57% and 10.50% of thedifference of every trait between two parents. It is very luckly to find a individual, 13BC2-3BC3 line, whose GL, GW, G/W, CH and BW were 6.04 mm, 2.43 mm, 2.49,2.5% and 2.5% separately, There is very important signification for it to be used in hybrid rice breeding improving appearance traits. In the research, MAS efficiency of 3 loci (with 4 markers ) was 5.68% and coincident degree was 73.08%.  相似文献   
70.
采用.OH、DPPH.、ABTS+清除能力及铁还原能力四种体外抗氧化活性评价方法,在模拟胃、小肠、血液三种不同的体内环境后,对笃斯越橘花色苷提取物(粗提物和精制物)的抗氧化功能进行了评价。结果显示,笃斯越橘花色苷精制物对.OH、DPPH.、ABTS+的清除及铁还原能力均高于粗提物。笃斯越橘花色苷提取物在模拟不同pH胃环境下对.OH、DPPH.、ABTS+的清除能力及铁还原能力由强至弱依次为:pH1.5、pH2.5、pH3.5、pH4.5;在模拟胃、小肠并血液环境下对.OH、DPPH.、ABTS+的清除能力及铁还原能力为:花色苷提取物在模拟胃环境下>模拟胃并小肠环境下>模拟胃、小肠并血液环境下。  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