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   179篇
  免费   0篇
  国内免费   5篇
林业   15篇
农学   5篇
基础科学   1篇
  54篇
综合类   6篇
农作物   27篇
水产渔业   8篇
畜牧兽医   62篇
园艺   1篇
植物保护   5篇
  2022年   2篇
  2021年   1篇
  2020年   1篇
  2019年   3篇
  2018年   5篇
  2017年   3篇
  2016年   5篇
  2015年   3篇
  2014年   6篇
  2013年   29篇
  2012年   6篇
  2011年   16篇
  2010年   7篇
  2009年   8篇
  2008年   10篇
  2007年   11篇
  2006年   15篇
  2005年   8篇
  2004年   11篇
  2003年   7篇
  2002年   9篇
  2001年   2篇
  2000年   3篇
  1999年   3篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1993年   3篇
  1992年   1篇
  1976年   1篇
  1965年   1篇
排序方式: 共有184条查询结果,搜索用时 15 毫秒
121.
122.
Although not scientifically proven, hoof trimming has been empirically shown to increase milk yields in healthy dairy cows. In this study, we examined the effect of one-time hoof trimming on blood biochemical composition, milk yield, and milk composition in healthy dairy cows. Eleven cows in the mid to late lactation period that were clinically fit and without hoof disease were subjected to hoof trimming, and metabolic profile tests and dairy herd improving tests were performed before and three weeks after the hoof trimming. The metabolic profiles showed changes in albumin, blood urea nitrogen, ammonia, glucose, and beta-hydroxybutyric acid as a result of the hoof trimming. This was indicated by the fact that the cows began to intake more roughage after hoof trimming than prior to hoof trimming, and rumen fermentation became stable. There was no change in milk yield after trimming. However, the milk fat and milk protein compositions were significantly increased after trimming.  相似文献   
123.
Organotins are among the most common marine pollutants in the world, as they are widely used as antifouling paint on ships and fishing nets. It has been reported that organotin preferentially accumulates in the central nervous system, especially in the retinal neurons of marine organisms including fish. In this study, we investigated the effects of waterborne tributyltin (TBT) on early-stage developing zebrafish (Danio rerio). Below the lethal concentrations, TBT specifically increased the number of apoptotic cells in the retina as well as some cells near trigeminal neurons, detected by terminal transferase-mediated nick-end-labeling staining. Apoptosis peaked at 60 hpf and decreased by 72 hpf, which was associated with macrophage accumulation. Furthermore, the effect of TBT was markedly inhibited by antioxidants, ascorbic acid or trolox. These results suggest that TBT preferentially induces apoptosis in the retinal neuron of developing zebrafish. Oxidative stress may be involved in this toxicological response.  相似文献   
124.
To investigate the relationships between trace elements concentrations in hair and atrial fibrillation (AF) in horses, concentrations of nineteen trace elements were detected in hair using the particle induced X-ray emission (PIXE) method. The horses were assigned to either control (n=22, no abnormalities) or AF groups (n=5) based on electrocardiograph findings. The mean concentrations of Ca and Zn in the hair of the AF group were significantly higher than those in the control group. The Zn/Cu ratio of the hair in the AF group (29.8 +/- 5.5) was significantly higher than that in the control group (23.4 +/- 2.2, P<0.05). The results of the present study suggest that there is a relationship between elevated concentrations of Ca and Zn in hair and AF.  相似文献   
125.
Anthocyanins were detected in extracts from the peels of 123 accessions of eggplant (Solanum melongena) and its related species. Their anthocyanin profiles were classified into four types, including known Japanese eggplant type (type 1) and non-Japanese eggplant type (type 2). Although most of the eggplant accessions had one of the two known profiles, one accession had a novel profile (type 3). Two accessions of related species showed another novel profile (type 4). The major anthocyanins were identified as delphinidin 3-(p-coumaroylrutinoside)-5-glucoside (nasunin) (type 1), delphinidin 3-rutinoside (type 2), delphinidin 3-glucoside (type 3), and petunidin 3-(p-coumaroylrutinoside)-5-glucoside (petunidin 3RGc5G) (type 4). Delphinidin 3-caffeoylrutinoside-5-glucoside (delphinidin 3RGcaf5G) was isolated from the hybrid (F1) plants of a type 1 cultivar and a type 3 germplasm. Among the five purified anthocyanins, delphinidin 3RGcaf5G showed the highest radical-scavenging activities toward both 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and linoleic acid radical, followed in order by nasunin and petunidin 3RGc5G.  相似文献   
126.
127.
International Aquatic Research - Survival time of juvenile pen shell Atrina pectinata (shell length&nbsp;≈&nbsp;34&nbsp;mm) exposed to hyposaline water without sediments was...  相似文献   
128.
ABSTRACT

Whole crop rice (WCR) is expected to establish a cultivation method using manure produced from animal wastes. Meanwhile, application methods of fertilizer and manure in the WCR cultivation are affected by availability of manure, available time for its application, and field drainage, and low market price of WCR. This raises concerns about soil fertility deterioration and yield reduction in the WCR cultivation. The objectives of this study were to investigate how different application methods of fertilizer and manure affected soil chemical properties and yield in the WCR cultivation. Field surveys were conducted in 2013 and 2014 at 10 fields cultivated by five different farmers in the Itoshima region, Fukuoka Prefecture, Japan. The surveyed fields included two application methods of manure (M) alone and chemical fertilizer (CF) alone. Clay plus silt content was significantly correlated with total nitrogen (TN), total phosphorus (TP), and exchangeable potassium (Exch. K), which indicated that soil texture partly contributed to the variations of these soil chemical properties. Meanwhile, clear gaps of TN, TP, Exch. K, K saturation degree, and available N between CF and M at around 40% of clay plus silt content strongly suggested that manure application contributed to increases in the soil chemical properties. Yearly differences of available N had relatively large negative values in CF fields. This result suggested a possible decrease in mineralizable part of soil TN in the WCR cultivation with CF alone, which needs to be clarified through long-term study. Significant relationships between potential N supply and straw weight (= 0.698, p < 0.05 for 2013; r = 0.873, p < 0.01 for 2014) or yield of whole crop (= 0.852, p < 0.01 for 2014) indicated that N mineralized from soil, which was enhanced by manure application, increased straw weight, resulting in an increase in yield of whole crop. However, excessive amounts of manure applied in surveyed fields can cause groundwater and surface water pollution. Thus, nutrient balances in a paddy field need to be analyzed further to determine an appropriate application amount of manure.  相似文献   
129.
A fungus was isolated from the skin of an Otaria byronia and from the water of the pool in which the animal was kept. It formed creamy colonies with soft texture on Dixon agar and grew well without supplements of long-chain fatty acids. Cells were ovoid to cylindrical in shape, budded from a broad base, and budded and divided at the same location. Thus, the isolate was identified as M. pachydermatis. We compared this very rare isolate from a marine mammal with four strains of M. pachydermatis using the freeze-etching electron-microscopy technique. The cells showed the same characteristic ring-swellings on the protoplasmic membrane on the neck site between the mother and the daughter parts, and the same accumulation of circumvallate bulgings in a small area near the straight sections of spiral grooves as four reference strains. Thus, in terms of morphology and ultrastructure, the isolate could be regarded as a typical M. pachydermatis.  相似文献   
130.
The complete coding region sequence of equine muscle-type phosphofructokinase (ePFKM) was obtained from skeletal muscle of a thoroughbred horse. The deduced amino acid sequence of ePFKM showed 97%, 96%, 96%, 96% and 95% identity to canine, human, mouse, rabbit and rat PFKM, respectively. The amino and carboxyl terminal halves of ePFKM presented a structure of tandem repeat, as other mammalian PFKMs. As the amino acid residues constituting various ligand-binding sites were also conserved, it is thought that ePFKM has enzymatic activity similar to PFKM in other mammals.  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