全文获取类型
收费全文 | 122篇 |
免费 | 7篇 |
国内免费 | 3篇 |
专业分类
林业 | 10篇 |
农学 | 8篇 |
25篇 | |
综合类 | 19篇 |
农作物 | 8篇 |
水产渔业 | 29篇 |
畜牧兽医 | 28篇 |
园艺 | 2篇 |
植物保护 | 3篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 2篇 |
2015年 | 3篇 |
2014年 | 5篇 |
2013年 | 7篇 |
2012年 | 7篇 |
2011年 | 15篇 |
2010年 | 10篇 |
2009年 | 7篇 |
2008年 | 11篇 |
2007年 | 5篇 |
2006年 | 9篇 |
2005年 | 8篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 6篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1988年 | 1篇 |
1973年 | 1篇 |
1970年 | 2篇 |
排序方式: 共有132条查询结果,搜索用时 15 毫秒
41.
Anna V. Eggertsdóttir DVM PhD Øyvind Stigen DVM PhD Lars Lønaas DVM PhD Marianne Langeland DVM PhD Morten Devor DVM Gunvor Vibe-Petersen DVM PhD Thomas Eriksen DVM PhD 《Veterinary surgery : VS》2001,30(6):546-551
OBJECTIVE: To compare the recurrence rate of acute gastric dilatation with or without volvulus (GDV) after circumcostal gastropexy (CCGP) or gastrocolopexy (GCP) in dogs. STUDY DESIGN: A prospective, double-blind, multicenter, randomized, controlled, clinical trial with two groups (A and B). ANIMALS: Fifty-four client-owned dogs presented for treatment of GDV. METHODS: Dogs with acute GDV that had not previously had a gastropexy performed were included. The preoperative treatment before gastropexy was standardized. A CCGP was performed on dogs in group A, and a GCP was performed on dogs in group B. Postoperative treatment was standardized, but deviation did occur according to the special needs of particular patients. A minimal follow-up time of 180 days was required for dogs not excluded from the study. The median follow-up time in group A was 700 days; in group B, it was 400 days. The occurrence of abdominal pain and gastrointestinal problems after surgery were recorded by the owners. RESULTS: There was no significant difference in the recurrence rate of GDV between the two groups. At the end of the study, the recurrence rate was 9% and 20% in group A and in group B, respectively. CONCLUSIONS: Both surgical techniques are effective in preventing recurrence of GDV. 相似文献
42.
Prestrud KW Asbakk K Fuglei E Mørk T Stien A Ropstad E Tryland M Gabrielsen GW Lydersen C Kovacs KM Loonen MJ Sagerup K Oksanen A 《Veterinary parasitology》2007,150(1-2):6-12
Samples (blood or tissue fluid) from 594 arctic foxes (Alopex lagopus), 390 Svalbard reindeer (Rangifer tarandus platyrhynchus), 361 sibling voles (Microtus rossiaemeridionalis), 17 walruses (Odobenus rosmarus), 149 barnacle geese (Branta leucopsis), 58 kittiwakes (Rissa tridactyla), and 27 glaucous gulls (Larus hyperboreus) from Svalbard and nearby waters were assayed for antibodies against Toxoplasma gondii using a direct agglutination test. The proportion of seropositive animals was 43% in arctic foxes, 7% in barnacle geese, and 6% (1 of 17) in walruses. There were no seropositive Svalbard reindeer, sibling voles, glaucous gulls, or kittiwakes. The prevalence in the arctic fox was relatively high compared to previous reports from canid populations. There are no wild felids in Svalbard and domestic cats are prohibited, and the absence of antibodies against T. gondii among the herbivorous Svalbard reindeer and voles indicates that transmission of the parasite by oocysts is not likely to be an important mechanism in the Svalbard ecosystem. Our results suggest that migratory birds, such as the barnacle goose, may be the most important vectors bringing the parasite to Svalbard. In addition to transmission through infected prey and carrion, the age-seroprevalence profile in the fox population suggests that their infection levels are enhanced by vertical transmission. 相似文献
43.
Pulley S. Morten C. Morgan S. Cardenas L. M. Collins A. L. 《Journal of Soils and Sediments》2022,22(2):692-703
Journal of Soils and Sediments - Modern agricultural practices have increased the losses of fine sediment and associated pollutants to watercourses with associated off-site degradation of water... 相似文献
44.
45.
46.
Themistoklis Altintzoglou Morten Heide 《Journal Of Aquatic Food Product Technology》2013,22(2):155-164
Consumers in England and France are exposed to different fish products and information at the marketplace. Based on this information and cultural differences, English and French consumers create expectations about fish products. The aim of this study was to compare English and French consumers on: (a) expectations regarding labeling on cod fillet products, (b) important factors when purchasing prepacked and fresh fish, and (c) drivers and barriers to fish consumption. English consumers (n = 120) reported in a survey more positive expectations about thawed products than French consumers (n = 120) due to greater familiarity with relevant labeling information. 相似文献
47.
48.
CIMMYT小麦品种Saar的叶锈成株抗性QTL分析 总被引:2,自引:1,他引:1
【目的】小麦品种Saar由CIMMYT育成,在欧洲、亚洲和南美洲对小麦叶锈、条锈和白粉病均表现出很高的成株抗性,发掘其成株抗叶锈QTL对于选育持久抗锈品种有重要作用。【方法】以Avocet与Saar杂交的109个F6代重组自交系为材料,利用142个SSR标记和209 DArT(Diversity Arrays Technology)标记构建连锁图,对Saar和Avocet的成株抗性进行QTL分析。试验材料于2006-2007年度种植在河北保定和河南新乡两个试验点,调查各个家系对叶锈病的成株抗性。【结果】由351个位点组成的遗传连锁图,覆盖小麦21个连锁群,全长3 083 cM。采用复合区间作图法进行叶锈成株抗性的QTL分析,在1BL、2DS、5BL、6AL和7DS染色体上发现了5个抗叶锈病QTL,分别解释4.5%~6.4%、12.2%~12.5%、4.9%~11.2%、4.9%~7.8%和14.0%~67.6%的表型变异。【结论】叶锈成株抗性基因及其紧密连锁分子标记的发掘,将为小麦抗叶锈病育种的分子标记辅助选择(MAS)提供理论和技术支持。 相似文献
49.
Inorganic nitrogen addition in a semi‐intensive turbot larval aquaculture system: effects on phytoplankton and zooplankton composition 下载免费PDF全文
Elisa Blanda Benni Winding Hansen Jacob Kring Højgaard Per Meyer Jepsen Morten Foldager Pedersen Thomas Allen Rayner Christina Vinum Thoisen Hans Henrik Jakobsen 《Aquaculture Research》2016,47(12):3913-3933
A nitrogen manipulation experiment was conducted in a semi‐intensive outdoor system where turbot larvae feed on copepods. Nitrogen addition is hypothesized to stimulate a cascade reaction increasing phytoplankton biomass, copepods’ productivity and larval fish survival. Triplicates were established for three treatments: a control with no additional nitrogen, a pulsed dose where nitrogen was added in three doses over time and a full dose where all nitrogen, equal to the total of the pulse dose treatment, was added initially. In the control, chlorophyll a averaged 3.3 ± 1.5 μg L?1 and phytoplankton was dominated by diatoms, while the pulsed and full dose treatments showed chlorophyll a at 28.6 ± 9.9 and 47.7 ± 10.0 μg L?1, respectively, with dinoflagellates as the main phytoplankton group. Due to photosynthesis, pH increased >9 in both the nitrogen treatments compared to the control (8.5). Potential toxic dinoflagellates, including Alexandrium pseudogonyaulax and Prorocentrum spp., became dominant in the nitrogen treatments and might have arrested zooplankton recruitment. Laboratory experiments with a toxic strain of A. pseudogonyaulax proved that Acartia tonsa reproduction and naupliar survival were affected negatively at realistic fish tank concentrations of 100 and 20 cells mL?1, respectively. Compared to the control, pulsed and full dose treatments reached higher copepod biomass and showed a shift over time in species composition from Centropages hamatus to Acartia spp. However, high pH levels and dinoflagellate blooms had a negative effect on larval fish survival, suggesting management improvements on water quality and separation between copepods and fish production tanks. 相似文献
50.
Berit B. Aam Ellinor B. Heggset Anne Line Norberg Morten S?rlie Kjell M. V?rum Vincent G. H. Eijsink 《Marine drugs》2010,8(5):1482-1517
Chitooligosaccharides (CHOS) are homo- or heterooligomers of N-acetylglucosamine and D-glucosamine. CHOS can be produced using chitin or chitosan as a starting material, using enzymatic conversions, chemical methods or combinations thereof. Production of well-defined CHOS-mixtures, or even pure CHOS, is of great interest since these oligosaccharides are thought to have several interesting bioactivities. Understanding the mechanisms underlying these bioactivities is of major importance. However, so far in-depth knowledge on the mode-of-action of CHOS is scarce, one major reason being that most published studies are done with badly characterized heterogeneous mixtures of CHOS. Production of CHOS that are well-defined in terms of length, degree of N-acetylation, and sequence is not straightforward. Here we provide an overview of techniques that may be used to produce and characterize reasonably well-defined CHOS fractions. We also present possible medical applications of CHOS, including tumor growth inhibition and inhibition of TH2-induced inflammation in asthma, as well as use as a bone-strengthener in osteoporosis, a vector for gene delivery, an antibacterial agent, an antifungal agent, an anti-malaria agent, or a hemostatic agent in wound-dressings. By using well-defined CHOS-mixtures it will become possible to obtain a better understanding of the mechanisms underlying these bioactivities. 相似文献