全文获取类型
收费全文 | 491篇 |
免费 | 34篇 |
专业分类
林业 | 66篇 |
农学 | 15篇 |
101篇 | |
综合类 | 20篇 |
农作物 | 38篇 |
水产渔业 | 29篇 |
畜牧兽医 | 183篇 |
园艺 | 21篇 |
植物保护 | 52篇 |
出版年
2023年 | 3篇 |
2021年 | 4篇 |
2020年 | 6篇 |
2019年 | 8篇 |
2018年 | 37篇 |
2017年 | 21篇 |
2016年 | 33篇 |
2015年 | 15篇 |
2014年 | 26篇 |
2013年 | 24篇 |
2012年 | 35篇 |
2011年 | 50篇 |
2010年 | 19篇 |
2009年 | 16篇 |
2008年 | 26篇 |
2007年 | 28篇 |
2006年 | 27篇 |
2005年 | 26篇 |
2004年 | 13篇 |
2003年 | 18篇 |
2002年 | 15篇 |
2001年 | 8篇 |
2000年 | 8篇 |
1999年 | 7篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1993年 | 3篇 |
1987年 | 2篇 |
1985年 | 3篇 |
1980年 | 2篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 2篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 2篇 |
1965年 | 2篇 |
1963年 | 2篇 |
1958年 | 1篇 |
1957年 | 1篇 |
1956年 | 1篇 |
1932年 | 1篇 |
1926年 | 2篇 |
1918年 | 2篇 |
排序方式: 共有525条查询结果,搜索用时 15 毫秒
141.
Zorica Nikolić Ksenija Taški-Ajduković Mladen Tatić Svetlana Balešević-Tubić 《Industrial Crops and Products》2009,29(2-3):638-641
The Vojvodina province is the most important agricultural area of the Republic of Serbia and is its largest soybean producer. Serbian low forbids the introduction of genetically modified organisms (GMO) into the environment and demands labeling of food containing more than 0.9% GMO. This aim of this study is to monitor the Roundup Ready (RR) soybean in fields and in food products using PCR and immunoassays. A duplex PCR reaction was performed to analyze the lectin gene and 35S promoter using DNA isolated from soybean leaf and seed sample. Specific detection of RR markers was performed using nested PCR and verified by immunoassay. RR soybeans were found in 68 fields in samples from 2003 and 28 fields in 2004. The presence of the RR soybean was confirmed in 44 seed samples out of 7142 samples examined in 2006 and in 108 out of 7171 samples examined in 2007. The data presented here are the first to demonstrate the presence of RR soybean in the Serbia fields. 相似文献
142.
Rusak Gordana Krajačićl Mladen Krsnik-Rasol Marijana Gutzeit Herwig O. 《植物病害和植物保护杂志》2007,114(4):145-150
Journal of Plant Diseases and Protection - Quercetin is a prominent flavonoid with a remarkable spectrum of biochemical activities. Its impact on human health, as well as its role in the normal... 相似文献
143.
Bozić F Srebocan E Kozarić Z 《Berliner und Münchener tier?rztliche Wochenschrift》2001,114(3-4):134-138
In order to assess the effects of starvation on intestinal intraepithelial lymphocytes (i-IEL) count and histological changes of the carp gut mucosa, one group of fish (n = 10) were fed commercially prepared standard diets and another group of fish (n = 10) were starved for 4 weeks. Carp starved for 4 weeks developed enteropathy, comprising folds atrophy, stratum compactum hyperplasia, significant periodic-acid-Schiff (PAS)-positive (P < 0.00001), but not Alcian blue (ALB)-positive, goblet cell (GC) hyperplasia and a significant decrease (P < 0.00001) in i-IEL numbers. These changes were associated with a dense cellular infiltrate into the lamina propria. Taken together, these data suggest that the pathobiology of starvation-induced i-IELs decrease, matching PAS-positive goblet cell proliferation and inflammatory cells homing to the gut, could be classified as a non-infectious enteropathy induced by starvation. 相似文献
144.
Herak-Perković V Grabarević Z Banić M Anić B Novosel V Pogacnik M 《Journal of veterinary pharmacology and therapeutics》2001,24(4):267-273
The aim of the study was to demonstrate the effects of dopaminergic drugs on 2,4-dinitrofluorbenzene (DNFB) induced experimental inflammatory bowel disease (IBD) in previously sensitized BALB/c mice. The number and extent of ulcerations and erosions, the intensity of haemorrhages, oedema, and accumulation of neutrophils and eosinophils within colonic lamina propria and submucosa were scored and statistically evaluated. The 180 BALB/c mice, were allocated into three equal groups. The mice in the first experimental group were treated with domperidone (DP), a peripheral dopamine (DA) antagonist. The mice from the second experimental group were treated with bromocriptine (BC), a dopamine agonist. The mice from the control group were treated with an equivalent volume of normal saline in the same manner. Ten animals from each group were killed on days 1, 2, 3, 5 and 10, subsequent to the challenge enema of DNFB solution. Gross and microscopic examination of the colon was performed. Treatment with BC resulted in clinical improvement and decreased mortality rate by 2 of 60 (3%), while domperidone treatment increased mortality rate to 12 of 60 (20%) compared with the controls [4 of 60 (6%)]. The analysis of the microscopic lesions indicated that the beneficial effects of BC were the result of maintenance of vascular integrity. 相似文献
145.
Epidemiological and microbiological study of an outbreak of infectious keratoconjunctivitis in sheep 总被引:1,自引:0,他引:1
After several thousand sheep had been imported from Australia and New Zealand to Croatia during 1995, many native sheep that had been in contact with the imported animals acquired a severe ocular disease closely resembling infectious keratoconjunctivitis. In affected flocks glucose-fermenting mycoplasma were isolated from 48 per cent of conjunctival swabs and Branhamella ovis from 58 per cent. Twelve of 42 culturally and biochemically identical isolates were identified as Mycoplasma conjunctivae by polymerase chain reaction. From the conjunctivae of two animals M conjunctivae and M arginini were isolated in mixed culture. For many reasons most farmers removed the imported animals from their flocks and only sporadic cases of the disease were recognised in 1996. At the end of 1997, six flocks which were clinically free of the disease but had been affected during 1995, and five flocks with no history of the severe ocular disease were examined clinically and microbiologically, and were found to be free of M conjunctivae infection. At the time, B ovis was cultured almost exclusively from sheep originating from flocks which had been affected during 1995 and/or 1996. It was usually isolated in pure culture or as the predominant bacterial species, and was often accompanied by mild conjunctivitis. There were no microbiologically confirmed new cases of infectious keratoconjunctivitis during 1998 and 1999. 相似文献
146.
Petar Kljajić Goran Andrić Marijana Pražić-Golić Dušanka Inđić Slavica Vuković 《Journal of pest science》2014,87(2):301-308
As very little is known about the impact of cold pre-treatments on insecticidal toxicity to the surviving stored-product insects, we examined the effects of cooling (?5 °C) on the toxicity of five contact insecticides to Sitophilus granarius adults from three populations (laboratory, field and selected). We determined: (a) weevil lethal time after exposure to ?5 °C, (b) the effects of two cold pre-treatments (LT20 and LT50—lethal time for 20 and 50 % of exposed adults) on 24 and 72 h recovery rates of laboratory adults after exposure to five insecticides and (c) deltamethrin, dichlorvos and malathion toxicity to two weevil populations with altered insecticide susceptibility after exposure to the LT20 and LT50 pre-treatments. The tested S. granarius populations showed no significant differences in their susceptibility to cooling. All insecticides except dichlorvos were more toxic to the laboratory weevils after 24 h than after 72 h recovery from the LT20 pre-treatment. Dichlorvos and deltamethrin were more toxic to the other two populations after 72 h of recovery. Comparing the effects of cold pre-treatment and non-treatment on the laboratory strain, no significant increase in the toxicity of insecticides was detected, while only deltamethrin was significantly more toxic to the field and selected populations recovering for 24 h (12.1 and 11.0 times, respectively) and 72 h (6.9 and 36.6 times) from the LT20 pre-treatment. In conclusion, only the shorter of the two cold pre-treatments was found effective in terms of increasing the insecticidal toxicity, especially against the populations with altered susceptibility to insecticides. 相似文献
147.
Ian Young Lisa Waddell Javier Sanchez Barbara Wilhelm Scott A. McEwen Andrijana Rajić 《Preventive veterinary medicine》2014
Knowledge synthesis refers to the integration of findings from individual research studies on a given topic or question into the global knowledge base. The application of knowledge synthesis methods, particularly systematic reviews and meta-analysis, has increased considerably in the agri-food public health sector over the past decade and this trend is expected to continue. The objectives of our review were: (1) to describe the most promising knowledge synthesis methods and their applicability in agri-food public health, and (2) to summarize the recent advancements, challenges, and opportunities in the use of systematic review and meta-analysis methods in this sector. We performed a structured review of knowledge synthesis literature from various disciplines to address the first objective, and used comprehensive insights and experiences in applying these methods in the agri-food public health sector to inform the second objective. We describe five knowledge synthesis methods that can be used to address various agri-food public health questions or topics under different conditions and contexts. Scoping reviews describe the main characteristics and knowledge gaps in a broad research field and can be used to evaluate opportunities for prioritizing focused questions for related systematic reviews. Structured rapid reviews are streamlined systematic reviews conducted within a short timeframe to inform urgent decision-making. Mixed-method and qualitative reviews synthesize diverse sources of contextual knowledge (e.g. socio-cognitive, economic, and feasibility considerations). Systematic reviews are a structured and transparent method used to summarize and synthesize literature on a clearly-defined question, and meta-analysis is the statistical combination of data from multiple individual studies. We briefly describe and discuss key advancements in the use of systematic reviews and meta-analysis, including: risk-of-bias assessments; an overall quality-of-evidence approach; engagement of stakeholders; Bayesian, multivariate, and network meta-analysis; and synthesis of diagnostic test accuracy studies. We also highlight several challenges and opportunities in the conduct of systematic reviews (e.g. inclusion of grey literature, minimizing language bias, and optimizing search strategies) and meta-analysis (e.g. inclusion of observational studies and approaches to address the insufficient reporting of data and significant heterogeneity). Many of these developments have yet to be comprehensively applied and evaluated in an agri-food public health context, and more research is needed in this area. There is a need to strengthen knowledge synthesis capacity and infrastructure at the regional, national, and international levels in this sector to ensure that the best available knowledge is used to inform future decision-making about agri-food public health issues. 相似文献
148.
Co-residence patterns in hunter-gatherer societies show unique human social structure 总被引:2,自引:0,他引:2
Hill KR Walker RS Bozicević M Eder J Headland T Hewlett B Hurtado AM Marlowe F Wiessner P Wood B 《Science (New York, N.Y.)》2011,331(6022):1286-1289
Contemporary humans exhibit spectacular biological success derived from cumulative culture and cooperation. The origins of these traits may be related to our ancestral group structure. Because humans lived as foragers for 95% of our species' history, we analyzed co-residence patterns among 32 present-day foraging societies (total n = 5067 individuals, mean experienced band size = 28.2 adults). We found that hunter-gatherers display a unique social structure where (i) either sex may disperse or remain in their natal group, (ii) adult brothers and sisters often co-reside, and (iii) most individuals in residential groups are genetically unrelated. These patterns produce large interaction networks of unrelated adults and suggest that inclusive fitness cannot explain extensive cooperation in hunter-gatherer bands. However, large social networks may help to explain why humans evolved capacities for social learning that resulted in cumulative culture. 相似文献
149.
Zoldoš Vlatka Vidaković-Cifrek Željka Tomić Mihovil Papeš Dražena 《Water, air, and soil pollution》1997,94(1-2):181-190
Allium test has already been used to determine cytotoxicity of waste drilling fluids. In the present work the cytotoxicity of four pure chemicals (Defoamex, Idthin 400, Magco Thin and Slick Pipe) was investigated. Those chemicals are components of drilling fluids, therefore, they are usually constituents of oil and gas industry waste waters. The tested chemicals were prepared in 1:9 dilution and cytotoxic effects on root-tip meristem ofAllium ascalonicum were analysed after 24-, 48- and 72-hour-treatments. All samples showed cytotoxicity which was proved by cytogenetic parameters such as inhibition of mitotic activity and increase of mitotic abnormalities and chromosomal aberrations in comparison with the control. Almost all mitotic abnormalities induced by four chemicals tested were the result of disturbed spindle mechanisms accompanied with stickiness. Slick Pipe revealed the most prominent mitodepressive effect and induced a high number of abnormalities. It caused a significant decrease of mitotic activity and increase of mitotic abnormalities after all three treatment durations, while chemicals Defoamex and Magco Thin showed a significant decrease of mitotic activity only after 72-hour-treatment. Chemicals Defoamex, Idthin 400 and Magco Thin revealed a significant increase of mitotic abnormalities after 48- and 72-hour-treatments. 相似文献
150.
Milisavljević MDj Timotijević GS Radović SR Brkljacić JM Konstantinović MM Maksimović VR 《Journal of agricultural and food chemistry》2004,52(16):5258-5262
An 8S storage globulin from buckwheat seed, which resembles the structure and features common to the vicilin-like family of seed storage proteins, was analyzed for this paper. It was found that expression of the 8S globulin gene precedes that of the 13S globulin (the main buckwheat storage protein) and starts from an early stage of buckwheat seed development (9-11 days after flowering), continuing to accumulate throughout seed development to contribute approximately 7% of total seed proteins. This protein fraction might be more interesting for biotechnological application than the 13S buckwheat legumin consisting of 23-25 kDa subunits reported to be the major buckwheat allergen. A partial cDNA was also isolated, showing high homology with cDNAs coding for vicilin-like storage proteins from various plant species, and its expression profile throughout seed development as well as in different buckwheat tissues was analyzed. 相似文献