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   34篇
  免费   0篇
  4篇
综合类   1篇
农作物   1篇
水产渔业   14篇
畜牧兽医   9篇
植物保护   5篇
  2022年   1篇
  2021年   2篇
  2019年   1篇
  2014年   2篇
  2012年   3篇
  2011年   1篇
  2009年   5篇
  2008年   2篇
  2007年   1篇
  2006年   1篇
  2005年   1篇
  2004年   6篇
  2002年   3篇
  1995年   2篇
  1993年   1篇
  1992年   2篇
排序方式: 共有34条查询结果,搜索用时 15 毫秒
1.
The effects of root-applied chalcone at 0.15 mmol L−1 on the growth and lignin biosynthesis in maize were investigated. The contents of 4-coumarate: CoA ligase (4CL, EC 6.2.1.12) substrates in maize shoots were increased more rapidly in the samples with chalcone application than in the control and the increase occurred at ≤ 3 h after the application (HAA). The lignin content was reduced by chalcone at ≤ 6 HAA. The shoot growth was suppressed by chalcone at ≤ 9 HAA. Consequently, the results suggest that chalcone suppressed maize growth by inhibiting monolignol biosynthesis.  相似文献   
2.
Radioisotope techniques are well known as methods for evaluating symplastic ion absorption in roots. In the present study, a new method for evaluating symplastic cadmium (Cd) absorption in plant roots was developed using the enriched isotopes 113Cd and 114Cd. Seedlings of Solanum melongena were exposed to an enriched isotope solution of 113Cd at 25°C for 30 min. The roots were excised from each seedling and were then immersed in a cold buffer solution without Cd at 2°C for 120 min to suppress the metabolic activity of the roots. Finally, the roots were treated with a cold buffer solution containing enriched stable isotope 114Cd at 2°C for 120 min, whereby the apoplastically bound 113Cd was desorbed. We tested the validity of our method for evaluating symplastic Cd in roots compared with the conventional method based on differences in the amount of Cd absorbed at 2°C and 25°C using unlabeled Cd. There was no difference in the symplastic Cd content of the roots between the two methods. These results indicate that it is possible to evaluate the symplastic Cd content in roots using the enriched isotopes 113Cd and 114Cd.  相似文献   
3.
4.
Regimes of high abundance of sardine (Sardinops sagax and Sardina pilchardus) have alternated with regimes of high abundance of anchovy (Engraulis spp.) in each of the five regions of the world where these taxa co-occur and have been extensively fished. When one taxon has been plentiful, the other has usually been at a reduced level of abundance, and vice versa. Changes in the four heavily fished regions that support S. sagax–the Japanese, Californian, Humboldt, and Benguela systems–from a regime dominated by one taxon to a high level of abundance of the other have occurred more or less simultaneously. In the Pacific Ocean, sardines have tended to increase during periods of increasing global air and sea temperatures and anchovies to decrease. The Japanese system is dominated by sardines to a greater extent than the other systems, and sardines off Japan appear to increase as the Kuroshio Current cools. At the eastern edge of the Pacific Ocean, sardines colonize cooler areas during periods of warming. The Benguela system is out of phase with the three Pacific systems. The four systems all appeared to be in a state of flux in the 1980s. Increased abundance of the subdominant taxon is often one of the first signs of change. Sardines are relatively sedentary in refuge areas when scarce but change behavior to become highly migratory and colonize cooler areas when abundant. Anchovies, by contrast, expand around a fixed geographic center.  相似文献   
5.
A cycle of fluctuation in the Far Eastern sardine, Sardinops sagax, population is accompanied by an abrupt drop and recovery of fish size and lipid content of parent fish, which may reflect a phase variation from coastal to oceanic and its reverse. The cycle begins with the survival success of a smaller number of eggs produced by high-quality parents, which is triggered by a global climate change (density-independent process), and finally ends in the survival failure resulting from an overexpansion of an enormous number of fish produced by low-quality parents (density-dependent process).  相似文献   
6.
7.
8.
Keratometry was performed in 73 domestic cats of varied signalment in Japan using an automated handheld keratometer. The mean corneal curvature radius was significantly lower for cats younger than 1 year than for those older than 2 years (8.04 mm vs. 8.80−8.99 mm, P<0.01). The radius was significantly greater in males than in females among the cats older than 11 years (9.22 mm vs. 8.84 mm, P=0.01), while the age distributions of the males and females were similar. Corneal astigmatism did not significantly differ across the gender and age groups. The predictability of the corneal curvature and astigmatism was approximately 41−43% and less than 3%, respectively, as a function of age and bodyweight. The results highlighted some age- and sex-related keratometric variations in domestic cats in Japan.  相似文献   
9.
本试验旨在研究饲粮中添加枯草芽孢杆菌(Bacillus subtilis,BS)对石门土鸡生长性能、屠宰性能、血清抗氧化指标和肠道形态的影响。选取540只55日龄、体重[(0.75±0.02) kg]相近的健康石门土鸡母鸡,随机分成3组,每组6个重复,每个重复30只鸡。对照组饲喂基础饲粮,试验组分别饲喂在基础饲粮的基础上添加300和600 mg/kg BS的试验饲粮。预试期7 d,正试期28 d。结果表明:1) 1~14 d时,与对照组相比,300、600 mg/kg BS组石门土鸡的平均日采食量(ADFI)和平均日增重(ADG)有提高趋势(P>0.05); 15~28 d和1~28 d时,各组间的ADFI、ADG和料重比(F/G)均无显著差异(P> 0.05)。2)与对照组相比,600 mg/kg BS组石门土鸡的屠宰率显著提高(P<0.05),300、600 mg/kg BS组的腹脂率有提高趋势(P>0.05);各组间的半净膛率、全净膛率、胸肌率、腿肌率均无显著差异(P>0.05)。3)与对照组相比,14 d时,300 mg/kg BS组石门土鸡的血清总超氧化物歧化酶(T-SOD)活性显著提高(P <0. 05); 14和28 d时,300、600 mg/kg BS组的血清谷胱甘肽过氧化物酶(GSH-Px)活性极显著提高(P <0.01)。4)与对照组相比,300、600 mg/kg BS组石门土鸡的十二指肠绒毛高度、绒毛宽度、隐窝深度均有提高趋势(P>0.05),300 mg/kg BS组的空肠绒毛宽度显著提高(P<0.05);各组间的回肠绒毛宽度、隐窝深度和绒隐比均无显著差异(P>0.05)。综上,饲粮中添加BS提高了石门土鸡的屠宰性能,增强了机体抗氧化能力,改善了肠道形态。  相似文献   
10.
We collected 17 milk samples at 1 day to 6 months post partum from one captive okapi (Okapia johnstoni). Milks were examined for nutrient composition, including water, fat, crude protein, carbohydrates, ash and five minerals. The average values of the concentrations were 79.2 ± 3.0% SD water, 8.5 ± 3.4% fat, 7.5 ± 1.1% crude protein, 3.6 ± 0.6% carbohydrate, 1.2 ± 0.1% ash, 263.7 ± 47.3 mg/100 g calcium, 183.0 ± 40.0 mg/100 g phosphorus, 95.2 ± 17.6 mg/100 g sodium, 74.4 ± 34.3 mg/100 g potassium and 28.4 ± 4.4 mg/100 g magnesium, respectively. The protein concentration increased at late lactation (P < 0.01). The contents of sodium and potassium were rather high in the early lactation period, while those of calcium and phosphorus were rather low in the early lactation period. During the course of lactation in the first week post partum and the protein concentration was high at 1 day post partum. We compare our findings with the American Association of Zoos & Aquariums's Okapi Species Survival Plan Hand‐rearing Protocol, and recommend that nutrient composition of the formula for okapi calves is developed using the present study as a guide.  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