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71.
Gill infections by the parasitic copepod Haemobaphes disphaerocephalus (family Pennellidae) were observed on a few Atlantic salmon reared at 2 seawater netpen sites in British Columbia. This is the first report of this parasite affecting salmonids. The terminal holdfast penetrated into a branchial artery and was associated with anemia.  相似文献   
72.
A study was made using a commercial strain of broiler chick (1 day to 9 weeks of age) and common starting and finishing rations, on the effects that various proportions of rye have on live performance and litter quality. All rations were maintained isocaloric by the appropriate addition of tallow.

It was ascertained that rye could comprise up to 25 per cent of the grain component without adverse effects when compared to those birds fed the control ration even though litter moisture was significantly increased. Increases in the percentage of rye to more than 25 per cent of the grain fraction resulted in progressively poorer live performance, dressed yield and carcass quality.  相似文献   

73.
74.
Biofilm formation where bacterial cells adhere to a surface and surround themselves in a polysaccharide matrix is thought to be an important factor in disease initiation and persistence for many bacterial species. We have examined biofilm formation by Mycoplasma mycoides subsp. mycoides small colony using a simple model without an air/liquid interface and have found that adherent Mmm SC was more resistant to many stresses, including heat, osmotic shock and oxidative stress. Biofilms of Mmm SC also exhibited remarkable persistence and were able to survive for up to 20 weeks in stationary phase. Significant variation was seen between Mmm SC strains in their ability to form a biofilm and the morphology of the biofilm produced with some strains unable to produce microcolonies. Proteomic analysis found that a number of proteins linked to adherence were over-expressed in biofilms compared with planktonic cells.  相似文献   
75.
Neutrophils play an important role in the exacerbation and maintenance of severe equine asthma; persistent neutrophil activity and delayed apoptosis can be harmful to surrounding tissues. Tamoxifen (TX) is a nonsteroidal estrogen receptor modulator with immunomodulatory effects and induces early apoptosis of blood and bronchoalveolar lavage neutrophils from horses with acute lung inflammation. This study investigated if the in vitro effects of tamoxifen are produced by its action on nuclear (α and β) and membrane (GPR30) estrogen receptors in healthy equine neutrophils. Results showed that TX inhibits neutrophil respiratory burst induced by opsonized zymosan in a dose‐dependent manner. Nuclear (17‐β‐Estradiol) and GPR30 cell membrane (G1) estrogen receptor agonists and their antagonists (ICI 182,780 and G15, respectively) do not block or reproduce the effect of TX. Therefore, TX does not inhibit respiratory burst through estrogen receptors. TX (8.5 μM) also increased phosphatidylserine translocation, a marker of early apoptosis, which did not occur with any of the estrogen receptor agonists or antagonists . Thus, tamoxifen generates dose‐dependent inhibition of respiratory burst and increased early apoptosis in healthy equine neutrophils, independently of nuclear or membrane estrogen receptors. Further studies are necessary to explore the signaling pathways of tamoxifen‐induced ROS inhibition and phosphatidylserine translocation.  相似文献   
76.
Dogs are often present on livestock farms, where they serve important management and companion roles, yet may be involved in zoonotic pathogen transmission. Numerous factors can potentially alter the risk of exposure to zoonotic pathogens, such as the dog's access to livestock, close dog–human contact and an increasing immunocompromised human population. The objective of this study was to quantify and qualify dog ownership among livestock owners, their dog husbandry and biosecurity practices, the dogs’ access to livestock and potential risks for zoonotic pathogen transmission. A questionnaire was developed and mailed to 2,000 presumed Ohio livestock owners. Data were collected on demographics, dog husbandry practices, attitudes surrounding zoonotic diseases and attachment to and preventive veterinary care for the dogs. There were 446 responders who met the study inclusion criteria as an Ohio livestock farm owner, with 297 (67%) also owning dogs. Approximately 52% of dog‐owning households included at least one individual at higher disease risk (i.e., <5 years, ≥65 years, diagnosed with an immunocompromising condition). Most respondents had little/no concern for disease transmission from livestock to dogs (90%), from dogs to livestock (87%) and from dogs to people (94%). Dogs were allowed access to livestock by 70% of respondents and nearly all (96%; 198) indicated at least one higher risk dog–livestock management practice. In addition, many reported never leashing or fencing their dog (61%) and rarely to never picking up dog faeces (76%). Households with higher risk members reported similar husbandry, biosecurity and concern levels as households without those members (all > .05). Numerous opportunities for zoonotic pathogen transmission and low level of zoonotic disease concern suggest a need for improved education and outreach for the livestock dog‐owning community, particularly for higher risk households.  相似文献   
77.
介绍了干气密封的基本结构、工作原理、在离心压缩机中应用干气密封的优点和转子的装配与运行要求。结合干气密封在天然气管道离心压缩机的应用实例,提出了干气密封的具体流程、控制系统和投产运行需要注意的问题。  相似文献   
78.
The kinematic strategy encoded in motor cortical areas for classic straight-line reaching is remarkably simple and consistent across subjects, despite the complicated musculoskeletal dynamics that are involved. As tasks become more challenging, however, different conscious strategies may be used to improve perceived behavioral performance. We identified additional spatial information that appeared both in single neurons and in the population code of monkey dorsal premotor cortex when obstacles impeded direct reach paths. The neural correlate of movement planning varied between subjects in a manner consistent with the use of different strategies to optimize task completion. These distinct planning strategies were manifested in the timing and strength of the information contained in the neural population code.  相似文献   
79.
Strategies for biodiversity conservation require society to make choices between competing outcomes. However, these choices are complicated by an incomplete understanding of the ecological significance of different species and the lack of robust measures of conservation outcomes in relation to investments. Cost-effectiveness analysis (CEA) provides an objective assessment process that can help us to evaluate the effectiveness of different conservation programmes and adjust them in an adaptive manner to improve the chances of success. CEA and other objectively-constructed methods should form an important part of the evidence base for conservation decision-making and evaluation.  相似文献   
80.
Sharka disease does not occur in Australia and is recognized as the most serious disease threat to Australia's stone fruit industry. Strategies are in place to minimize the risk that exotic diseases like sharka should establish in Australia. These are achieved by implementing: (1) pre-import measures to reduce the threat of entry; (2) controls at the point of entry and (3) response and contingency planning to contain or eradicate any incursions into Australia. An active and on-going awareness programme within the Australian stone fruit industry is aimed at early detection of sharka disease in the orchard.  相似文献   
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