全文获取类型
| 收费全文 | 120篇 |
| 免费 | 1篇 |
专业分类
| 林业 | 2篇 |
| 农学 | 15篇 |
| 20篇 | |
| 农作物 | 1篇 |
| 水产渔业 | 14篇 |
| 畜牧兽医 | 54篇 |
| 园艺 | 4篇 |
| 植物保护 | 11篇 |
出版年
| 2023年 | 1篇 |
| 2022年 | 4篇 |
| 2021年 | 4篇 |
| 2020年 | 3篇 |
| 2016年 | 3篇 |
| 2015年 | 8篇 |
| 2014年 | 14篇 |
| 2013年 | 8篇 |
| 2012年 | 8篇 |
| 2011年 | 4篇 |
| 2010年 | 6篇 |
| 2009年 | 5篇 |
| 2008年 | 7篇 |
| 2007年 | 7篇 |
| 2006年 | 6篇 |
| 2005年 | 7篇 |
| 2004年 | 4篇 |
| 2003年 | 4篇 |
| 2002年 | 6篇 |
| 2001年 | 3篇 |
| 2000年 | 4篇 |
| 1998年 | 1篇 |
| 1996年 | 1篇 |
| 1995年 | 2篇 |
| 1991年 | 1篇 |
排序方式： 共有121条查询结果，搜索用时 31 毫秒
111.
Four experiments were conducted to estimate dietary lysine (Lys) requirements using plasma amino acid concentrations as a criterion in mature thoroughbreds. In each experiment four adult thoroughbreds were used. The changes in plasma Lys concentration after feeding were observed in Experiment 1. Blood samples were taken from the cervix vein 0.5 h before, and 1, 3, 5.5, and 10 h after feeding. The plasma Lys concentration increased and remained constant until 3 h after feeding, decreased until 5.5 h and remained constant after then. Therefore, the bleed was done at 3 h after feeding in all later experiments. To make sure of the response speed of the plasma Lys to changes of dietary Lys levels, dietary Lys levels were changed from high to low, and low to high levels in Experiment 2. Blood samples were taken just on the changing day and 1, 2 and 3 days after changing diets. The plasma Lys concentration decreased until 2 days after changing the diet, and then remained constant with advancing days after changing the diet from high Lys to low Lys. On the other hand, the plasma Lys increased until one day after changing the diet, and then remained constant with advancing days after changing dietary Lys levels. Thus, blood samples were taken 3 days after feeding in the next experiments. The possibility of estimating the Lys requirement for maintenance using plasma Lys concentration was elucidated by two methods in Experiments 3 and 4. In Experiment 3, the horses were fed a diet containing 0.33 percent Lys for 3 days. After this the diet was changed to diets containing higher levels of Lys to 0.40, 0.47, 0.54, and 0.61 percent every third day. The Lys requirement was estimated to be 0.46 percent of diet from the response of plasma Lys concentration of five Lys levels. In Experiment 4, a 4 × 4 Latin square design was used for four dietary Lys levels. The Lys requirement was estimated to be 0.47 percent of the diet with a plasma Lys concentration of four Lys levels. 相似文献
112.
113.
114.
ABSTRACT: Stress and immune responses were studied in Nile tilapia Oreochromis niloticus under both conditions of self-feeding and scheduled feeding. Self-feeding fish had a significantly lower cortisol level in their blood plasma than that of scheduled feeding fish. Furthermore, skin color was found to be paler in the self-feeding fish compared with that of the scheduled feeding fish. Thus, the self-feeding fish had a less stressful physiological status than the other experimental fish. Immunological analyses revealed that the self-feeding fish significantly exceeded the scheduled feeding fish in the phagocytic activity of their macrophages, antibody production, and the number of blood-circulating lymphocytes. The higher immune responses of self-feeding fish seem to be attained through a less stressful environment. This self-feeding behavior could be exploited to create reduced stress for disease control in fish farming. 相似文献
115.
116.
117.
118.
Eiichi TAKASU Humiei YAMADA Nagao SHIMADA Yoshiaki YOSHIDA Masahiko SAIGUSA 《Soil Science and Plant Nutrition》2006,52(2):251-251
(pp. 1–7)
Application of phosphogypsum PG and limestone to Andisol were compared in terms of their effects on the growth and uptake of Ca in Komatsuna Brassica rapa L. cv. Natsurakuten. The studies were carried out in soil pot cultures, and both PG and limestone were applied to the Andisol at the rates of 0, 0.30, 0.75, 1.50 g kg−1 in the form of CaO.
Application of phosphogypsum PG and limestone to Andisol were compared in terms of their effects on the growth and uptake of Ca in Komatsuna Brassica rapa L. cv. Natsurakuten. The studies were carried out in soil pot cultures, and both PG and limestone were applied to the Andisol at the rates of 0, 0.30, 0.75, 1.50 g kg
- 1)
Limestone application resulted in an increase in the soil pH. On the other hand, no change was observed in the case of PG application at pH 6.1 ± 0.1 regardless of the application rate. Both soil EC and water-soluble Ca increased in proportion to the PG application rate, and this increase was approximately 5 times greater than that observed when limestone was applied at 1.50 g kg
−1 . The w-Ca/ex-Ca ratio (water-soluble Ca: 1 M acetic acid-extractable Ca) was clearly increased from 0.12 up to 0.26 in PG, while the value was slightly decreased from 0.12 to 0.05 in limestone.
119.
Thermophilic ammonia-oxidizing bacteria (AOB) have the potential to reduce ammonium emissions from commercial-scale animal waste composting operations. Two new media have been designed to culture and enumerate thermophilic AOB species. C-1 medium was designed to reflect compost composition. C-2 medium and CQ-2 medium were modified synthetic organic wastewater for the cultivation and enumeration of AOB, respectively. These new media have several advantages over the conventional medium. C-2 medium is effective for nitrification at 50°C, and C-1 and C-2 media support reasonable growth of thermophilic AOB. Furthermore, C-1 and CQ-2 media allow enumeration of thermophilic AOB during the composting process. This is the first report of the successful cultivation and enumeration of thermophilic AOB in compost. These results suggest the possibility of isolation and manipulation of novel thermophilic AOB species for environmental bioremediation. 相似文献
120.
To investigate the role of polyamines in pre- and post-harvest fruit development of 'Akatsuki' peach (Prunus persica (L.) Batsch.) we measured polyamine concentrations, activities of polyamine biosynthetic enzymes and expression of genes encoding these enzymes. Concentrations of the free polyamines, putrescine (Put), spermidine (Spd) and spermine (Spm) in pre-harvest fruit peaked 16 days after full bloom (DAF) and then progressively decreased until harvest with the exception of Put, which showed a second peak at 94 DAF, just before the onset of ethylene production. In post-harvest fruit, minor changes in concentrations of Spd and Spm were observed, whereas Put concentration peaked on the harvest day, followed by an abrupt decrease and a subsequent 2-fold increase, which was opposite to the fluctuating pattern of ethylene production. Activities of arginine decarboxylase (ADC) and ornithine decarboxylase (ODC) peaked during the first stage of fruit development and then decreased until 80 DAF, after which the activities were below detection limits, suggesting that Put is synthesized during the early stage of fruit development. Activity of S-adenosylmethionine decarboxylase (SAMDC) decreased progressively until the end of S2. Expression levels of five putative polyamine biosynthetic genes, ADC, ODC, SAMDC, spermidine synthase (SPDS) and spermine synthase (SPMS), in pre-harvest and post-harvest fruit did not coincide precisely with the observed changes in enzymatic activities and polyamine concentrations. The possible role of polyamines during peach fruit development and the relationship between polyamines and ethylene biosynthesis are discussed. 相似文献