全文获取类型
收费全文 | 378篇 |
免费 | 8篇 |
专业分类
林业 | 3篇 |
农学 | 1篇 |
7篇 | |
综合类 | 325篇 |
农作物 | 3篇 |
水产渔业 | 1篇 |
畜牧兽医 | 41篇 |
园艺 | 2篇 |
植物保护 | 3篇 |
出版年
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 8篇 |
2015年 | 2篇 |
2014年 | 6篇 |
2013年 | 3篇 |
2012年 | 15篇 |
2011年 | 24篇 |
2010年 | 11篇 |
2009年 | 2篇 |
2008年 | 37篇 |
2007年 | 25篇 |
2006年 | 34篇 |
2005年 | 58篇 |
2004年 | 57篇 |
2003年 | 46篇 |
2002年 | 39篇 |
2000年 | 1篇 |
1996年 | 1篇 |
1987年 | 2篇 |
1984年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1973年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有386条查询结果,搜索用时 15 毫秒
1.
Guangyu Wang Tongli Wang Haijun Kang Shari Mang Brianne Riehl Brad Seely Shirong Liu Futao Guo Qinglin Li John L. Innes 《林业研究》2016,27(3):469-488
Climate change is a threat to the stability and productivity of forest ecosystems throughout the Asia-Pacific region. The loss of forests due to climate-induced stress will have extensive adverse impacts on biodiversity and an array of ecosystem services that are essential for the maintenance of local economies and public health. Despite their importance, there is a lack of decision-support tools required to evaluate the potential effects of climate change on Asia-Pacific ecosystems and economies and to aid in the development of regionally appropriate adaptation and mitigation strategies. The project Adaptation of Asia-Pacific Forests to Climate Change, summarized herein, aims to address this lack of knowledge and tools and to provide support for regional managers to develop effective policy to increase the adaptive capacity of Asia-Pacific forest ecosystems. This objective has been achieved through the following activities: (1) development of a high-resolution climate downscaling model, ClimateAP, applicable to any location in the region; (2) development of climate niche models to evaluate how climate change might affect the distribution of suitable climatic conditions for regionally important tree species; (3) development and application of forest models to assess alternative management strategies in the context of management objectives and the projected impacts of climate change; (4) evaluation of models to assess forest fire risk and the relationship between forest fire and climate change; (5) development of a technique to assess ecosystem carbon storage using LiDAR; and (6) evaluation of how vegetation dynamics respond to climate change using remote sensing technology. All project outputs were developed with a focus on communication and extension to facilitate the dissemination of results to regional forest resource managers to support the development of effective mitigation and adaptation policy. 相似文献
2.
Dudley JI Lekli I Mukherjee S Das M Bertelli AA Das DK 《Journal of agricultural and food chemistry》2008,56(20):9362-9373
It is generally believed that the French paradox is related to the consumption of red wine and not other varieties of wine, including white wine or champagne. Some recent studies have indicated that white wine could also be as cardioprotective as red wine. The present investigation compares the cardioprotective abilities of red wine, white wine, and their principal cardioprotective constituents. Different groups of rats were gavaged with red wine, white wine, resveratrol, tyrosol, and hydroxytyrosol. Red wine and its constituent resveratrol and white wine and its constituents tyrosol and hydroxytyrosol all showed different degrees of cardioprotection as evidenced by their abilities to improve postischemic ventricular performance, reduce myocardial infarct size and cardiomyocyte apoptosis, and reduce peroxide formation. It was discovered in this study that although each of the wines and their components increased the enzymatic activities of the mitochondrial complex (I-IV) and citrate synthase, which play very important roles in oxidative phosphorylation and ATP synthesis, some of the groups were more complex-specific in inducing the activity compared to the other groups. Cardioprotective ability was further confirmed by increased expression of phospho-Akt, Bcl-2, eNOS, iNOS, COX-1, COX-2, Trx-1, Trx-2, and HO-1. The results of this study suggest that white wine can provide cardioprotection similar to red wine if it is rich in tyrosol and hydroxytyrosol. 相似文献
3.
Guangyu Wang Shari L.Mang Brianne Riehl Jieying Huang Guibin Wang Lianzhen Xu Kebiao Huang John Innes 《林业研究》2019,(1):277-293
Expert opinions have been used in a variety of fields to identify relevant issues and courses of action. This study surveys experts in forestry and climate change from the Asia–Pacific region to gauge their perspectives on the impacts of climate change and on the challenges faced by forest adaptation in the region, and explores recommendations and initiatives for adapting forests to climate change. There was consensus regarding the impacts of climate change on forest ecosystems and on economic sectors such as agriculture and forestry. Respondents also indicated a lack of public awareness and policy and legislation as challenges to addressing climate change. However, the results indicate differences in opinion between regions on the negative impacts of climate change and in satisfaction with actions taken to address climate change,highlighting the need for locally specific policies and research. The study presents specific recommendations to address issues of most concern, based on subregion and professional affiliation throughout the Asia–Pacific region.The results can be used to improve policy and forest management throughout the region. This research will also provide valuable suggestions on how to apply research findings and management recommendations outside of the AP region. The conclusions should be communicated relative to the level of the research and the target audience,ensuring that scientific findings and management recommendations are effectively communicated to ensure successful implementation of forest adaptation strategies. 相似文献
4.
Thomas R. De Ridder Justine E. Campbell Cheryl Burke‐Schwarz David Clegg Emily L. Elliot Samuel Geller Wendy Kozak Stephen T. Pittenger Jennifer B. Pruitt Jocelyn Riehl Julie White Melissa L. Wiest Chad M. Johannes John Morton Pamela D. Jones Peter F. Schmidt Victoria Gordon Paul Reddell 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2021,35(1):415-429
5.
6.
7.
The yields of inflorescences, corms and cormlets, and the inflorescence quality of winter-grown gladioli in south-east Queensland, were studied under 2 daylength regimes, 3 plant densities (150 000, 300 000 and 450 000 corms ha?1) and 3 plant arrangements (bed, double row and single row). The daylength treatments were the natural daylength (12.3–14.5 hours) and a 24-hour photoperiod treatment in which natural daylengths were extended using incandescent light of an intensity of 150 lux. Two cultivars were used.Extending the photoperiod to 24 hours delayed flowering by approximately 15 days, and increased the number of inflorescences harvested from low, medium and high density treatments by 20, 91 and 169%, respectively, when compared to the inflorescence yield from these density treatments under natural daylengths. The quality of the inflorescences from the high-density treatment receiving the 24-hour photoperiod was similar or superior in all quality characteristics to that of inflorescences grown under the most favourable density treatment under natural daylengths (150 000 corm ha?1). Plant arrangement had little effect on the number of days to flowering or inflorescence yield but inflorescence quality was improved when plants were grown in a double-row arrangement compared to those from the bed or single-row arrangements. Extension of the photoperiod had no effect on the number of new corms per plot. However, the average weight of new corms and the weight of cormlets per plot and per corm were reduced by approximately 32, 71 and 63%, respectively, when compared to the results obtained from plants grown under natural daylengths. These results suggest that flowers compete for available photosynthates with corms and cormlet development.The economic feasibility of extending photoperiod for the commercial production of winter-grown gladioli in south-east Queensland is discussed. 相似文献
8.
Mwangi DM Honda Y Graham SP Pelle R Taracha EL Gachanja J Nyanjui JK Bray J Palmer GH Brown WC Mwangi W 《Veterinary immunology and immunopathology》2011,140(3-4):244-251
Theileria parva antigens recognized by cytotoxic T lymphocytes (CTLs) are prime vaccine candidates against East Coast fever in cattle. A strategy for enhancing induction of parasite-specific T cell responses by increasing recruitment and activation of dendritic cells (DCs) at the immunization site by administration of bovine Flt3L and GM-CSF prior to inoculation with DNA vaccine constructs and MVA boost was evaluated. Analysis of immune responses showed induction of significant T. parva-specific proliferation, and IFN-γ-secreting CD4(+) and CD8(+) T cell responses in immunized cattle. However, antigen-specific CTLs were not detected. Following lethal challenge, 5/12 immunized cattle survived by day 21, whereas all the negative controls had to be euthanized due to severe disease, indicating a protective effect of the vaccine (p<0.05). The study demonstrated the potential of this technology to elicit significant MHC class II and class I restricted IFN-γ-secreting CD4(+) and CD8(+) T cells to defined vaccine candidate antigens in a natural host, but also underscores the need to improve strategies for eliciting protective CTL responses. 相似文献
9.
10.