全文获取类型
收费全文 | 700篇 |
免费 | 67篇 |
国内免费 | 4篇 |
专业分类
林业 | 59篇 |
农学 | 45篇 |
基础科学 | 10篇 |
131篇 | |
综合类 | 57篇 |
农作物 | 67篇 |
水产渔业 | 140篇 |
畜牧兽医 | 220篇 |
园艺 | 10篇 |
植物保护 | 32篇 |
出版年
2024年 | 1篇 |
2023年 | 6篇 |
2022年 | 15篇 |
2021年 | 32篇 |
2020年 | 44篇 |
2019年 | 43篇 |
2018年 | 54篇 |
2017年 | 45篇 |
2016年 | 36篇 |
2015年 | 26篇 |
2014年 | 33篇 |
2013年 | 39篇 |
2012年 | 53篇 |
2011年 | 49篇 |
2010年 | 29篇 |
2009年 | 31篇 |
2008年 | 26篇 |
2007年 | 23篇 |
2006年 | 39篇 |
2005年 | 20篇 |
2004年 | 27篇 |
2003年 | 14篇 |
2002年 | 12篇 |
2001年 | 11篇 |
2000年 | 9篇 |
1999年 | 9篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1958年 | 1篇 |
排序方式: 共有771条查询结果,搜索用时 31 毫秒
661.
Tu Thanh Dung Freddy Haesebrouck Patrick Sorgeloos Nguyen Ahn Tuan Frank Pasmans Annemieke Smet Annemie Decostere 《Aquaculture (Amsterdam, Netherlands)》2009,295(3-4):157-159
Eight tetracycline resistant Edwardsiella ictaluri isolates obtained from diseased freshwater catfish (Pangasianodon hypophthalmus) in Vietnam, and showing different resistance phenotypes to other antimicrobial agents, were studied. The tet genes were determined using PCR. Conjugation experiments were performed to assess transferability of the tetracycline resistance determinant and the size and incompatibility group (Inc) of each tet-carrying plasmid were determined. PCR and sequencing were used for characterization of the co-transferred resistance genes. A tetA gene was demonstrated in the E. ictaluri isolates and for all of them, Escherichia coli transconjugants were obtained. All transconjugants contained high-molecular weight tetA-carrying plasmids (~ 140 kb) belonging to the incK group, as was shown with the PCR-based replicon typing method. The strA–strB, dhfr1 and sul 2 genes were detected on the tetA-carrying plasmids of the transconjugants showing resistance to streptomycin, trimethoprim and sulfonamides, respectively. The dhfr1 gene was found to be located in a class 1 integron as determined by PCR and sequencing. Interestingly, the 3′ CS region of class 1 integrons was not detected by PCR. This study shows the presence of incK plasmid-mediated tetracycline resistance among E. ictaluri isolates from diseased freshwater catfish in Vietnam. 相似文献
662.
Naoyuki FUKE Nguyen Van DIEP Takuya HIRAI Mathurot SUWANRUENGSRI Uda Zahli IZZATI Ryoji YAMAGUCHI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(11):1661
An eighteen-year-old female Eurasian otter became emaciated and died. Necropsy examination revealed nose and thoracic cutaneous masses, abdominal subcutaneous mass, and multiple nodules in the liver and lungs. Malignant melanoma was found in the nose cutaneous mass and to have metastasized to the liver, lungs, kidneys, adrenal glands, mammary glands and left mandibular lymph node. The neoplastic cells were labeled for vimentin, melanoma, and S100. The cutaneous mass in the thoracic area consisted of spindle shaped neoplastic epithelial cells and was diagnosed as trichoblastoma. Mammary gland adenoma was observed in the abdominal subcutaneous mass. This is the first report of primary three neoplasms of malignant melanoma, trichoblastoma and mammary gland adenoma in a Eurasian otter. 相似文献
663.
664.
Nguyen Thanh Vu Nguyen Van Sang Trinh Quoc Trong Nguyen Huynh Duy Nguyen Thi Dang Nguyen Hong Nguyen 《Journal of fish diseases》2019,42(10):1409-1417
Bacillary necrosis of Pangasius (BNP), caused by Edwardsiella ictaluri, is one of the most devastating diseases in striped catfish farming. To date, quantitative genetic inheritance of BNP resistance is not known in striped catfish Pangasianodon hypophthalmus. The main aim of this study was to estimate genetic parameters for BNP resistance in a breeding population of striped catfish undergoing four generations of selection for high growth. Specifically, the study examined whether BNP resistance is heritable to enable family selection and whether genetic improvement for enhanced BNP resistance may have detrimental effects on growth and survival rate. To test these hypotheses, 720 full‐ and half‐sib families were challenged with E. ictaluri pathogen using injection and cohabitation methods over four years, from 2010 to 2012 and 2015. In total, the data included 398,234 animals in the pedigree, from which 18,849 animals had disease challenge test records and 39,103 siblings had growth performance. Both univariate and bivariate sire–dam linear and threshold mixed models were used to estimate (co)variance components for BNP resistance, survivals and growth traits. The estimates of heritability for the BNP resistance recorded as death or survival were low regardless of models used (0.10–0.16), whereas survival time (days post‐challenge test) showed moderate heritability (0.35). The survival rate during hapa rearing had medium heritability (0.33–0.52). The genetic correlations of BNP resistance with body weight and survival were all positive (0.03–0.53), suggesting that selection of increased BNP resistance may have positive impacts on growth and survival traits, and these traits could be easily improved simultaneously in the selective breeding programme for striped catfish. 相似文献
665.
666.
Kim T. Tran‐Ngoc Son T. Huynh Joo Sendo Thinh H. Nguyen Arjen J. Roem Johan A. J. Verreth Johan W. Schrama 《Aquaculture Nutrition》2019,25(1):134-144
The impact of two dietary organic acids (OAs) on nutrient digestibility and intestinal morphology was determined in Nile tilapia under conditions of dissolved oxygen in the water: normoxia and hypoxia. Four diets designated as control (0 g/kg organic acid salt), KDF (2 g/kg potassium diformate), CAB (2 g/kg calcium butyrate) and their combination (4 g/kg of a mixture of KDF and CAB, ration 1:1) were formulated with 520 g/kg of soybean meal in order to produce soybean meal enteritis‐like symptoms. The four diets were tested first under normoxic conditions (6 mg/L) for a period of 5 weeks, followed by a test period under hypoxic conditions (3 mg/L). The results showed that OAs were unable to significantly improve growth and nutrient digestibility under normoxic conditions but under hypoxic conditions, there was a significant enhancement of the growth and nutrient digestibility. Fish fed OA‐supplemented diets showed improvements in the intestinal morphology under the normoxic conditions, and these effects were more pronounced under the hypoxic conditions. Experimental findings suggest that OAs can improve the nutrient digestibility and intestinal morphology under hypoxic conditions. A synergistic effect by the combination of formic and butyric acid on growth, digestibility and intestinal morphology was not found. 相似文献
667.
Thang Nguyen Dinh Tu Le Dinh Le Na Nguyen Thi Trang Ngo Thi Nghia Phan Tuan 《International Aquatic Research》2019,11(3):303-310
International Aquatic Research - Viral diseases are a serious issue for the shrimp aquaculture industry. White spot syndrome virus (WSSV) has been considered one of the most dangerous pathogens... 相似文献
668.
Khiem Nguyen Minh Takahashi Yuki Oanh Dang Thi Hoang Hai Tran Ngoc Yasuma Hiroki Kimura Nobuo 《Fisheries Science》2020,86(4):673-683
Fisheries Science - Predicting the outbreak of disease is essential when managing shrimp farms. Acute hepatopancreatic necrosis disease (AHPND) caused by Vibrio parahaemolyticus is a serious... 相似文献
669.
Manh N. Hoang Phuoc N. Nguyen Ana Maria Vital Estrocio Martins Bossier Peter Bossier 《Aquaculture Research》2020,51(6):2603-2612
A comparative study was carried out to compare the effect of caging mullet and tilapia in a shrimp polyculture system. In six shrimp tanks (three tanks for each fish species), either mullet, Mugil cephalus (CCT‐SM), or tilapia, Oreochromis niloticus (CCT‐ST), was stocked in cages. In three other tanks, mullets were allowed to roam freely in shrimp tanks (D‐SM). White shrimp, Litopenaeus vannamei (0.50 g), was cultured as the predominant species were distributed randomly into nine fibreglass tanks (5 m3) at a density of 300 shrimp/tank, while fish (1.50 g) were stocked at the same density of 10% of the initial total shrimp biomass. The results showed that water quality parameters were not significantly different among treatments (p > .05), except for total suspended solids (TSSs). System performances based on parameters such as total weight gain (2,808.15 g/tank) and nutrient recovery were higher in D‐SM treatment (39.80% for nitrogen and 27.40% for phosphorus) than in CCT‐SM and CCT‐ST treatments (p < .05). These system performance parameters were significantly affected by the mullet‐holding strategy; however, they were not affected by fish species. The addition of mullet or tilapia in shrimp tanks did not affect shrimp growth differentially. Fish growth performances based on parameters such as final weight (98.43 g/fish) and DGR (1.29 g/day) were significantly higher in D‐SM treatment and were significantly different among D‐SM, CCT‐SM and CCT‐ST treatments (p < .05). It is concluded that in shrimp–fish polyculture with a stocking density of fish at 10% of the initial total shrimp biomass, tilapia is more effective than mullet, when caged. However, under free‐roaming conditions, the use of mullet is more effective in terms of system performances relative to a system holding caged tilapia. 相似文献