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   103篇
  免费   5篇
  国内免费   3篇
林业   4篇
农学   6篇
基础科学   1篇
  3篇
综合类   34篇
农作物   1篇
水产渔业   3篇
畜牧兽医   36篇
园艺   4篇
植物保护   19篇
  2023年   1篇
  2022年   1篇
  2021年   3篇
  2020年   2篇
  2019年   3篇
  2018年   1篇
  2017年   10篇
  2016年   4篇
  2015年   6篇
  2014年   4篇
  2013年   4篇
  2012年   4篇
  2011年   7篇
  2010年   9篇
  2009年   5篇
  2008年   3篇
  2007年   9篇
  2006年   2篇
  2005年   4篇
  2004年   2篇
  2002年   2篇
  2001年   2篇
  2000年   2篇
  1999年   2篇
  1998年   2篇
  1997年   2篇
  1996年   4篇
  1995年   2篇
  1994年   2篇
  1993年   1篇
  1991年   1篇
  1990年   1篇
  1989年   2篇
  1972年   1篇
  1958年   1篇
排序方式: 共有111条查询结果,搜索用时 11 毫秒
91.
采用酵母双杂交系统,利用SMART技术,在酵母菌株AH109中构建了小粒野生稻全长cDNA文库,文库容量约为1×106,插入片段平均大小约为640bp。该文库可以用于进一步的酵母双杂交筛选。  相似文献   
92.
盐胁迫对乌拉尔甘草种子萌发的影响研究   总被引:2,自引:1,他引:2  
研究了NaCl和Na2SO4不同浓度下两种中性盐胁迫对乌拉尔甘草种子萌发的效应。结果表明:280mmol/L浓度的NaCl和Na2SO4处理时,发芽率高于60%,高浓度的Na2SO4抑制种子发芽强于NaCl;不同浓度Na2SO4处理的发芽高峰期出现比对照早3~5d,比NaCl处理的早2~6d;Na2SO4处理种子的发芽势小于相同浓度的NaCl;溶液浓度大于200mmol/L时,种子发芽指数小于对照,NaCl溶液各梯度处理下的发芽指数均高于相应浓度的Na2SO4。发芽率、发芽势和发芽指数与NaCl和Na2SO4浓度之间呈极显著的负相关,发芽高峰期的出现与NaCl浓度之间呈正相关,与Na2SO4浓度之间呈负相关。  相似文献   
93.
94.
In Bos taurus cattle, antimullerian hormone (AMH) has been demonstrated to have a high degree of correlation with ovarian antral follicle count and the number of healthy follicles and oocytes. To document the correlation between the plasma concentration of AMH and follicular number in Bos indicus and Bos taurus heifers, Nelore (Bos indicus, n = 16) and Holstein heifers (Bos taurus, n = 16) had their ovarian follicular waves synchronized. After synchronization, ovarian antral follicular population (AFP) was evaluated three times at 60‐day (d) intervals (T‐120 d, 120 days before plasma AMH determination; T‐60 d, 60 days before; and T0, at the time of plasma AMH determination). The plasma AMH concentration was positively correlated with the number of ovarian follicles on the day of the follicular wave emergence in Bos indicus (Nelore) and Bos taurus (Holstein) heifers at each evaluation time (p < 0.05). The AFP was higher in Bos indicus (Nelore) than in Bos taurus (Holstein) heifers (p < 0.05). Similarly, the AMH concentration was higher in Bos indicus (Nelore) than in Bos taurus (Holstein) heifers (p < 0.0001). When heifers were classified as to present high or low AFP according to the mean of the AFP within each genetic group, high‐AFP heifers presented a greater (p < 0.0001) AMH concentration than low‐AFP heifers, regardless of the genetic group. In conclusion, the AFP is positively correlated with plasma AMH concentration in both Bos indicus (Nelore) and Bos taurus (Holstein) heifers. Furthermore, Bos indicus (Nelore) heifers presented both greater plasma AMH concentrations and AFP than Bos taurus (Holstein) heifers.  相似文献   
95.
高效液相色谱法测定兽用阿苯达唑片的含量   总被引:2,自引:1,他引:2  
利用高效液相色谱法测定兽用阿苯达唑片的含量。方法线性范围是10~150μg/mL,r=0.9994,RSD=2.5%。与紫外分光光度法对比,证明高效液相法可鉴别出紫外法不能鉴别的伪劣药品。该法操作简便快速,结果准确可靠。  相似文献   
96.
Reasons for performing study: Previous studies have suggested that agreement between equine veterinarians subjectively evaluating lameness in horses is low. These studies were limited to small numbers of horses, evaluating movement on the treadmill or to evaluating previously‐recorded videotape. Objectives: To estimate agreement between equine practitioners performing lameness evaluations in horses in the live, over ground setting. Methods: 131 mature horses were evaluated for lameness by 2–5 clinicians (mean 3.2) with a weighted‐average of 18.7 years of experience. Clinicians graded each limb using the AAEP lameness scale by first watching the horse trot in a straight line only and then after full lameness evaluation. Agreement was estimated by calculation of Fleiss' (κ). Evaluators agreed if they picked the same limb as lame or not lame regardless of the severity of perceived lameness. Results: After only evaluating the horse trot in a straight line clinicians agreed whether a limb was lame or not 76.6% of the time (κ= 0.44). After full lameness evaluation clinicians agreed whether a limb was lame or not 72.9% of the time (κ= 0.45). Agreement on forelimb lameness was slightly higher than on hindlimb lameness. When the mean AAEP lameness score was >1.5 clinicians agreed whether or not a limb was lame 93.1% of the time (κ= 0.86), but when the mean score was ≤1.5 they agreed 61.9% (κ= 0.23) of the time. When given the task of picking whether or not the horse was lame and picking the worst limb after full lameness evaluation, clinicians agreed 51.6% (κ= 0.37) of the time. Conclusions: For horses with mild lameness subjective evaluation of lameness is not very reliable. Potential relevance: A search for and the development of more objective and reliable methods of lameness evaluation is justified and should be encouraged and supported.  相似文献   
97.
98.
99.
张引弟  孟慧君  塔娜 《草业科学》2010,27(5):130-135
牧区草地承包经营权流转,是伴随草原新三牧政策(休牧、禁牧、划区轮牧)实施、畜牧业增长方式转型、牧区产业结构调整、牧区剩余劳动力转移等过程集中出现,又事关牧区民生与构建和谐新牧区的一个崭新的重要研究命题。本研究阐明内蒙古牧区草地承包经营权流转现状与特征,指出伴随草地流转出现租赁期短、草畜平衡对草地流转限制等问题以及牧区草地流转动因与东中部土地流转不同、草地类型流转程度不同的特征。畜产品是牧民主要收入来源,草地流转价格低影响牧民增收、加大牧区剩余劳动力转移风险。在牧区调研的基础上,提出建立与完善草地承包经营权流转机制的政策建议。  相似文献   
100.
观赏竹在昆明市园林绿化应用中存在的问题及对策措施   总被引:1,自引:0,他引:1  
通过对昆明市观赏竹种应用现状的调查,在了解不同竹种的生态习性和生物学特性基础上,分析现阶段观赏竹在昆明城市园林绿化应用中所存在的问题;并根据园林建设的需要提出了改进措施,以期为提高昆明市的观赏竹应用水平提供一定的实践及理论指导。  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