全文获取类型
收费全文 | 326篇 |
免费 | 21篇 |
专业分类
林业 | 23篇 |
农学 | 10篇 |
基础科学 | 4篇 |
81篇 | |
综合类 | 10篇 |
农作物 | 29篇 |
水产渔业 | 42篇 |
畜牧兽医 | 87篇 |
园艺 | 23篇 |
植物保护 | 38篇 |
出版年
2023年 | 5篇 |
2022年 | 11篇 |
2021年 | 9篇 |
2020年 | 6篇 |
2019年 | 16篇 |
2018年 | 22篇 |
2017年 | 19篇 |
2016年 | 19篇 |
2015年 | 13篇 |
2014年 | 14篇 |
2013年 | 33篇 |
2012年 | 25篇 |
2011年 | 26篇 |
2010年 | 19篇 |
2009年 | 23篇 |
2008年 | 20篇 |
2007年 | 14篇 |
2006年 | 12篇 |
2005年 | 12篇 |
2004年 | 10篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1993年 | 2篇 |
1989年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有347条查询结果,搜索用时 531 毫秒
341.
Fikret Karaca Melih Aksoy Abdullah Kaya Mehmet B. Ataman Tevfik Tekeli 《Veterinary radiology & ultrasound》1999,40(4):402-406
Ultrasonographic appearance of the testis and epididymis, and seminal characteristics, with regard to localization of spermatic granuloma were studied. In rams with spermatic granuloma (n = 9), diagnosed by clinical or ultrasonographic examinations before histopathological confirmation, localization of each lesion was recorded. Epididymal granulomas, caput and cauda, were seen as anechoic or hyperechoic areas with a distinct margin with or without a hyperechoic capsule. Granulomas in the testis were microscopic and, therefore, could not be detected by ultrasonography. Enlargement in the mediastinum testis was detected in all rams when there were granulomas in the caput. Heterogeneous testis parenchyma invaded by numerous hyperechoic foci, representing testicular degeneration, was associated with granulomas both in the epididymis and testis. Ultrasonographic appearance of the lesions did not differ with regard to season. Seminal characteristics varied between rams. It was concluded that ultrasonographic evaluation may give valuable information in the diagnosis of sperm granuloma in the ram. 相似文献
342.
Ümit Acar Osman Sabri Kesbi Burak Evren nanan Sevdan Ylmaz 《Aquaculture Research》2019,50(11):3305-3312
The aim of the present study was to evaluate the effects of essential oil extracted from bergamot (Citrus bergamia) peel on growth performance and health status of European sea bass juveniles (5.10 + 0.05 g). Test diets supplemented with 0.0%, 0.5%, 1.0% and 2.0% bergamot peel oil (BPO0, BPO0.5, BPO1 and BPO2) were fed to experimental fish for 60 days. At the end of the experiment, the best growth performance was obtained in the BPO0.5 and BPO1 groups (p < .05). No significances were found for haematological parameters including red blood cell count, haematocrit and haemoglobin concentration at the end of the feeding experiment. There were significant differences between the total protein, cholesterol, alkaline phosphatase and glutamic oxaloacetic transaminase (p < .05) between the BPO0.5 and BPO1 supplemented groups and the control group with no BPO addition. The addition of BPO showed significant differences in immune parameters such as lysozyme activity, total myeloperoxidase content, superoxide dismutase and glutathione peroxidase activity between BPO0 and BPO supplemented groups (p < .05). It might be concluded that dietary addition of 0.5%‐1% BPO could increase the growth performance and feed utilization with improved health status in sea bass juveniles. 相似文献
343.
Pre‐challenge and post‐challenge haemato‐immunological changes in Oreochromis niloticus (Linnaeus, 1758) fed argan oil against Lactococcus garvieae
下载免费PDF全文
![点击此处可从《Aquaculture Research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Esin Baba Ümit Acar Sevdan Yılmaz Canan Öntaş Osman Sabri Kesbiç 《Aquaculture Research》2017,48(8):4563-4572
The present study investigated the effects of argan oil, obtained from Argania spinosa, on pre‐ and post‐challenge immuno‐haematological and biochemical responses of Nile tilapia, Oreochromis niloticus. For this purpose, the fish were fed diets containing 0, 0.5%, 1% or 2% argan oil for 45 days. Following 45 days of feeding, fish were challenged with Lactococcus garvieae and mortality was recorded for 15 days. During the pre‐challenge period, significantly higher respiratory burst activity, total white blood cell (WBC), serum lysozyme activity and myeloperoxidase activity were determined in the argan oil‐fed groups. The serum glucose and cholesterol levels decreased whilst total protein and albumin did not change in the groups fed with argan oil‐supplemented diets. After challenge with Lactococcus garvieae, the percentage survival (%) was found to be the highest in the 1% and 2% argan oil‐supplemented feeding groups. Also, there was a significant increase in weight gain, specific growth rate and feed conversion ratio in those fish fed argan oil. The results of this study indicated that after the supplementation of fish diets with argan oil, especially at 1% and 2% concentrations, the immunological, haematological and biochemical values remained similar in both the pre‐ and post‐challenge periods and the immune response against L. garvieae in Nile tilapia was modulated. 相似文献
344.
Cengiz Kaya Muhammed Ashraf Osman Sonmez Salih Aydemir Atilla Levent Tuna Mehmet Ali Cullu 《Scientia Horticulturae》2009
This study investigated the effects of arbuscular mycorrhizal (AM) colonisation by Glomus clarum on growth and fruit yield of pepper (Capsicum annum cv. 11B 14) grown at high salinity. The experiment was conducted in pots containing a mixture of perlite and sand (1:1, v/v) under glasshouse conditions. Treatments were: (1) no added NaCl without arbuscular mycorrhizae (NS-AM), (2) no added NaCl with arbuscular mycorrhizae (NS + AM), (3) added 50 mM NaCl without arbuscular mycorrhizae (S1-AM) and (4) added 100 mM NaCl without arbuscular mycorrhizae (S2-AM), (5) added 50 mM NaCl with arbuscular mycorrhizae (S1 + AM) and (4) added 100 mM NaCl with arbuscular mycorrhizae (S2 + AM). The NaCl treatments reduced pepper shoot and root dry matter, and fruit yield compared with the non-saline treatments. The concentrations of N, P and K, in the leaves were significantly reduced by salinity stress, however, mycorrhizal colonisation of the salt-stressed plants restored leaf nutrient concentrations to the levels in non-stressed plants in most cases. AM inoculation improved pepper growth under salt or saltless conditions and reduced cell membrane leakage. 相似文献
345.
346.
Modeling water flow and solute transport in vadose zone requires knowledge of soil hydraulic properties, which are water retention and hydraulic conductivity curves. As an alternative to direct measurement, indirect determination of these functions from basic soil properties using pedotransfer functions (PTFs) has attracted the attention of researchers in a variety of fields such as soil scientists, hydrologists, and agricultural and environmental engineers. In this study, PTFs for point and parametric (van Genuchten's parameters) estimation of soil hydraulic parameters from basic soil properties such as particle-size distribution, bulk density, and three different pore sizes were developed and validated using artificial neural network (ANN) and multiple-linear regression methods and the predictive capabilities of the two methods was compared using some evaluation criteria. Total of 195 soil samples was divided into two groups as 130 for the development and 65 for the validation of PTFs. Although the differences between the two methods were not statistically significant (p > 0.05), regression predicted point and parametric variables of soil hydraulic parameters better than ANN. Both methods had lower accuracy in parametric predictions than in point predictions. Accuracy of the predictions was evaluated by the coefficient of determination (R2) and the root mean square error (RMSE) between the measured and predicted parameter values. The R2 and RMSE varied from 0.637 to 0.979 and from 0.013 to 0.938 for regression, and varied from 0.444 to 0.952 and from 0.020 to 3.511 for ANN, respectively. Even though regression performs insignificantly better than ANN in this case, ANN produces promising results and its advantages can be utilized by developing or using new algorithms in future studies. 相似文献
347.
Many phosphate solubilizing microorganisms (PSM) require external pyrroloquinoline quinone (PQQ) for strong phosphorus (P)
solubilization in vitro. The objective of this study was to isolate efficient and PQQ-independent PSM. A total of 21 PSM were
isolated from the rhizosphere soil of wheat and maize grown in the pots. Acinetobacter strains were the only PQQ-independent and most effective solubilizers of tricalcium phosphate containing agar. The mean P
dissolved in liquid cultures of Acinetobacter strains in a 5-day incubation ranged from 167 to 888 μg/ml P. The pH dropped to below 4.7 from 7.8 in six isolates, which
produced gluconic acid in concentrations ranging between 27.5 and 37.5 mM. There was a linear regression between soluble P
and gluconic acid concentrations in the bacterial cultures (P < 0.05; R
2 = 0.59). Inoculation with Acinetobacter sp. WR922 significantly (P < 0.05) increased wheat (Triticum aestivum L.) P content by 27% at 15 days after emergence (DAE) and dry matter by 15% at 30 DAE compared to the control. The plant
P content in inoculated plants at 30 DAE was linearly correlated with soluble P of the bacterial cultures (P < 0.05; R
2 = 0.69). Gluconic acid production directly affected phosphate solubilization in vitro, which in turn influenced plant P content
of inoculated plants in PQQ-independent P-solubilizing Acinetobacter strains. 相似文献