全文获取类型
收费全文 | 351篇 |
免费 | 62篇 |
专业分类
林业 | 19篇 |
农学 | 6篇 |
46篇 | |
综合类 | 6篇 |
农作物 | 16篇 |
水产渔业 | 34篇 |
畜牧兽医 | 254篇 |
园艺 | 5篇 |
植物保护 | 27篇 |
出版年
2024年 | 1篇 |
2023年 | 5篇 |
2022年 | 10篇 |
2021年 | 8篇 |
2020年 | 23篇 |
2019年 | 20篇 |
2018年 | 24篇 |
2017年 | 26篇 |
2016年 | 24篇 |
2015年 | 18篇 |
2014年 | 29篇 |
2013年 | 25篇 |
2012年 | 31篇 |
2011年 | 26篇 |
2010年 | 22篇 |
2009年 | 13篇 |
2008年 | 15篇 |
2007年 | 9篇 |
2006年 | 16篇 |
2005年 | 14篇 |
2004年 | 8篇 |
2003年 | 9篇 |
2002年 | 4篇 |
2000年 | 1篇 |
1999年 | 7篇 |
1998年 | 4篇 |
1997年 | 6篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1980年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有413条查询结果,搜索用时 31 毫秒
71.
Ronaldo J. Torres Denis M. S. Abessa Fernando C. Santos Luciane A. Maranho Marcela B. Davanso Marcos R. L. do Nascimento Antonio A. Mozeto 《Journal of Soils and Sediments》2009,9(5):420-432
Background, aim, and scope
Contaminated sediments are a worldwide problem, and mobilization of contaminants is one of the most critical issues in environmental risk assessment insofar as dredging projects are concerned. The investigation of how toxic compounds are mobilized during dredging operations in the channel of the Port of Santos, Brazil, was conducted in an attempt to assess changes in the bioavailability and toxicity of these contaminants. 相似文献72.
73.
Jaine H. H. L. de Oliveira Mirna H. R. Seleghim Christoph Timm Achim Grube Matthias K?ck Gislene G.F. Nascimento Ana Claudia T. Martins Elissa G. O. Silva Ana Olívia de Souza Paulo R. R. Minarini Fabio C. S. Galetti Célio L. Silva Eduardo Hajdu Roberto G. S. Berlinck 《Marine drugs》2006,4(1):1-8
Cyclostellettamines A – F (1 – 6) isolated from the sponge Pachychalina sp. and cyclostellettamines G - I, K and L (7 – 11) obtained by synthesis were evaluated in bioassays of antimicrobial activity against susceptible and antibiotic-resistant Staphylococcus aureus, Pseudomonas aeruginosa and antibiotic-susceptible Escherichia coli and Candida albicans, as well as in antimycobacterial activity against Mycobacterium tuberculosis H37Rv bioassays. The results obtained indicated that cyclostellettamines display different antimicrobial activity depending on the alkyl-chain size, suggesting that, if a mechanism-of action is implied, it is dependent on the distance between the two pyridinium moieties of cyclostellettamines. 相似文献
74.
M Apparicio AE Alves EA Pires‐Butler APC Ribeiro GJ Covizzi WRR Vicente 《Reproduction in domestic animals》2011,46(5):896-903
The aim of this study was to evaluate the effects of hCG, progesterone and oestradiol supplementation on nuclear and cytoplasmic maturation of canine oocytes cultured for 24, 48, 72 and 96 h. Oocytes obtained from 18 healthy bitches were divided into three groups according to their reproductive status (follicular, luteal and anoestrus stages) and cultured in TCM 199 + 25 UI/ml of hCG + 1 μg/ml of progesterone + 1 μg/ml of 17‐β oestradiol or without hormonal supplementation (control) for different periods. Then, they were stained with FITC‐LCA‐Hoescht for chromatin configuration and cortical granules distribution and evaluated under an epifluorescence microscope. Culture time and the influence of different stages of the oestrous cycle were also evaluated. The present study demonstrated that there was no significant difference among the reproductive stages. With regards to culture medium, only oocytes from the supplemented medium were able to complete meiosis; however, significant difference was only noticed in the percentage of MI stage oocytes (p < 0.05) in the follicular and luteal group at 72 h of culture. Most oocytes in germinal vesicle, germinal vesicle breakdown and metaphase I stage had cortical granules distributed throughout the cytoplasm (immature pattern), irrespective of the culture period (p < 0.05). Cortical granules distributed immediately beneath the plasma membrane (mature) was only observed in metaphase II stage oocytes, but not all of them presented matured cytoplasm. Our results reveal that cortical granules distribution in canine oocytes matured in vitro did not progressed in correspondence with nuclear stage changes and are in accordance with those from other species. 相似文献
75.
AE Domínguez‐Rebolledo F Martínez‐Pastor AF Bisbal JL Ros‐Santaella O García‐Álvarez A Maroto‐Morales AJ Soler JJ Garde MR Fernández‐Santos 《Reproduction in domestic animals》2011,46(3):393-403
Oxidative stress represents a challenge during sperm manipulation. We have tested the effect of increasing hydrogen peroxide (H2O2) levels on red deer spermatozoa after cryopreservation, and the role of male‐to‐male variation in that response. In a first experiment, eight thawed samples were submitted to 0, 25, 50, 100 and 200 μm H2O2 for 2 h at 37°C. Intracellular reactive oxygen species (H2DCFDA‐CM) increased with H2O2 concentration, but we only detected a decrease in sperm function (motility by CASA and chromatin damage by sperm chromatin structure assay) with 200 μm . Lipoperoxidation assessed by the thiobarbituric acid reactive substance (TBARS) method increased slightly with 50 μm H2O2 and above. In a second experiment, samples from seven males were submitted to 0 and 200 μm H2O2 for 2 h, triplicating the experiment within each male. Males differed at thawing and regarding their response to incubation and H2O2 presence. We found that the kinematic parameters reflected male‐to‐male variability, whereas the response of the different males was similar for lipid peroxidation and viability. A multiparametric analysis showed that males grouped differently if samples were assessed after thawing, after incubation without H2O2 or after incubation with H2O2. Red deer spermatozoa are relatively resilient to H2O2 after thawing, but it seems to be a great male‐to‐male variability regarding the response to oxidative stress. The acknowledgement of this individual variability might improve the development of optimized sperm work protocols. 相似文献
76.
AE Jackson 《Australian veterinary journal》2011,89(11):423-424
H1N1 influenza in pigs in Australia · Postnatal neurogenetic disorders · Deltamethrin collar for paralysis ticks in dogs · Myocardial laceration from sewing needle · Physiotherapy for tetanus in a foal · Morbillivirus in a bottle‐nosed dolphin · Sarcoptic manage in a swamp wallaby · Psychological health of veterinarians in Australia · History of the Australian College of Veterinary Scientists 相似文献
77.
全球禽肉生产和贸易中的沙门菌风险评估与控制 总被引:1,自引:0,他引:1
G.Mead A.M.Lammerding N.Cox M.P.Doyle F.Humbert A.Kulikocskiy A.Panin V.P.do Nascimento M.Wierup 《中国家禽》2011,33(5)
1 禽源沙门菌对公共卫生的影响
在许多国家,沙门菌仍是引发食源性肠道疾病的主要原因.沙门菌通常存在于家畜、家禽中,也可在啮齿类、爬行类和鸟类等野生动物中发现.当农场的禽群感染沙门菌后,通常会有一部分家禽的消化道中携带沙门菌,但并无症状.随后,沙门菌可能会通过粪便污染感染动物屠体. 相似文献
78.
Felipe A Nascimento Naiara C Silva Laura F Prados Rodrigo D L Pacheco Bradley J Johnson Bruno I Cappellozza Flvio D Resende Gustavo R Siqueira 《Journal of animal science》2020,98(12)
We hypothesized that the inclusion of calcium salts of fatty acid (CSFA) into the diets and the fatty acid (FA) profile of the supplements would impact performance and meat characteristics of Bos indicus bulls. Hence, the objective was to evaluate the effects of CSFA profiles on intake, body weight (BW), carcass, and meat characteristics of feedlot-finished B indicus bulls. Fifty-three Nellore bulls [initial BW 315 ± 5.9 kg and 20 ± 2 mo] were used. At the beginning, 6 bulls were randomly chosen and slaughtered for determination of their BW composition, and the remaining 47 bulls were evaluated during a 140-d experimental period. The bulls were placed in individual pens, blocked according to initial BW and randomly allocated to 1 of the 3 following treatments: (1) control diet containing sugarcane bagasse, ground corn, citrus pulp, peanut meal, and mineral–vitamin mix (CON), (2) CON with the addition of 3.3% of CSFA from soybean oil (CSO), or (3) CON with the addition of a mixture of 3.3% of CSFA from palm, soybean, and cottonseed oils (CPSCO). Diets were offered ad libitum and formulated to be isonitrogenous. Bulls supplemented with CSFA had a greater (P < 0.01) final BW, dry matter intake, average daily gain (ADG), feed efficiency (FE), and FA intake vs. CON. Among carcass parameters, CSFA-supplemented bulls had greater (P < 0.01) carcass ether extract concentration vs. CON bulls. When the CSFA profile was evaluated (CSO vs. CPSCO), CPSCO bulls had a better (P ≤ 0.03) FE, carcass ADG, and hot carcass weight (HCW) vs. CSO bulls. The FA intakes differed among CSFA treatments, as the total saturated, palmitic, and oleic FA intakes were greater for CPSCO (P < 0.01), whereas lower intakes of total unsaturated and polyunsaturated FA (P < 0.01) were observed for CPSCO vs. CSO. Samples from the Longissimus muscle contained greater palmitoleic (P = 0.01) and reduced linoleic (P = 0.02) FA concentrations in CSFA-supplemented bulls vs. CON bulls. In agreement with the FA intakes, CPSCO-supplemented bulls had a greater (P ≤ 0.05) unsaturated FA concentration vs. CSO in Longissimus muscle. In summary, CSFA supplementation improved the performance of finishing B. indicus bulls vs. CON. Moreover, the inclusion of CSFA from palm, soybean, and cottonseed oil benefited the FE, carcass ADG, and HCW compared with the inclusion of CSFA from soybean oil, demonstrating the potential of specific FA for improving the performance and meat quality of B. indicus bulls. 相似文献
79.
da Silva Kleitiane Balduino de Oliveira Juliana Silva Santos Edson Mauro Cartaxo Felipe Queiroga Guerra Ricardo Romão do Nascimento de Souza Aelson Fernandes Muniz Ana Cecília Souza de Lima Cruz Gabriel Ferreira 《Tropical animal health and production》2020,52(2):637-645
Tropical Animal Health and Production - This study examined rumen fermentation, histological, blood, and urinary characteristics as well as ammoniacal nitrogen concentration, pH, nitrogen balance,... 相似文献
80.
Moura Lais Micaelle Lopes da Silva Pereira Flávia Denise de Lima Patrícia Rodrigues Nascimento Júlio Cesar Silva dos Santos de Oliveira Andresca de Souza Rodrigues Rafael Torres Ferreira Clébio Pereira Moraes Salete Alves Queiroz Mário Adriano Ávila Menezes Daniel Ribeiro 《Tropical animal health and production》2020,52(5):2433-2441
Tropical Animal Health and Production - The aim of this study was to evaluate the effect of adding different concentrations of either urea or NaOH in dehydrated acerola (Malpighia emarginata) fruit... 相似文献