全文获取类型
收费全文 | 239篇 |
免费 | 3篇 |
专业分类
林业 | 30篇 |
农学 | 4篇 |
87篇 | |
综合类 | 25篇 |
农作物 | 7篇 |
水产渔业 | 6篇 |
畜牧兽医 | 57篇 |
园艺 | 8篇 |
植物保护 | 18篇 |
出版年
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 1篇 |
2016年 | 4篇 |
2015年 | 1篇 |
2014年 | 7篇 |
2013年 | 9篇 |
2012年 | 14篇 |
2011年 | 20篇 |
2010年 | 6篇 |
2009年 | 10篇 |
2008年 | 12篇 |
2007年 | 18篇 |
2006年 | 9篇 |
2005年 | 14篇 |
2004年 | 27篇 |
2003年 | 14篇 |
2002年 | 11篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1966年 | 2篇 |
1938年 | 1篇 |
1933年 | 5篇 |
排序方式: 共有242条查询结果,搜索用时 15 毫秒
231.
Kroly Erdlyi Lszl Dencs Rbert Lehoczki Mikls Heltai Krisztina Sonkoly Sndor Csnyi Norbert Solymosi 《Veterinary microbiology》2009,138(1-2):20-26
Roe deer papillomavirus (CcPV1) infection has been identified as an endemic disease in roe deer populations of the Carpathian basin in Central Europe (Hungary, Austria and Croatia). The disease is characterised by easily recognizable skin tumours similar to deer papillomavirus infection of North American deer species. In 2006, a questionnaire study was conducted among all Hungarian game management units (GMUs) in order to assess the distribution of the disease and its major epidemiological features. Categorical information was collected about disease occurrence, trend and frequency of detection, on primarily affected age classes in both sexes, and association of lesions with mortality. Replies were received from 539 GMUs representing 50.9% of total GMU territory and disease presence was reported by 295 (54.7%) GMUs. Older age classes of both sexes were found to be more affected. Association of various environmental factors with disease occurrence was evaluated and data were collected on the occurrence of similar skin lesions in other European countries. Pathological features of CcPV1 infection were described and the localisation of both CcPV1 antigen and DNA was characterised by immunohistochemistry and in situ DNA hybridisation in skin lesions. Virus presence was also demonstrated by PCR and PCR product sequencing. 相似文献
232.
233.
Impact of α‐amylase supplementation on energy balance and performance of high‐yielding dairy cows on moderate starch feeding 下载免费PDF全文
Martin Bachmann Mandy Bochnia Norbert Mielenz Joachim Spilke Wolfgang B. Souffrant Elisabeth Azem Wolfgang Schliffka Annette Zeyner 《Animal Science Journal》2018,89(2):367-376
In dairy cows, exogenous α‐amylase is suggested to improve starch utilization and positively affect performance and health traits linked to energy balance and fertility. In a 1‐year feeding experiment, 421 cows were orally supplemented with α‐amylase (treatment: 12.5 g/kg dry matter (DM) addition rate to a concentrated feed) or non‐supplemented (control) on the basis of an ad libitum total mixed ration (TMR). Every cow was allocated to a high‐ (≥32 kg milk/day) or late‐lactation group (<32 kg milk/day), in which the TMR starch content was 220 ± 20.8 g/kg DM and 183 ± 24.8 g/kg DM, respectively. The energetic effect of α‐amylase supplementation seemed to be exclusively related to the high‐lactation stage (5–100 days in milk) in primiparous cows, where the daily milk yield was 32 ± 0.49 versus 31 ± 0.50 kg per cow in the treatment versus control group (P < 0.05). The pluriparous cows did not benefit from the supplementation that way. In neither primiparous nor pluriparous cows, was the milk composition, the fat‐to‐protein ratio, the somatic cell score, the backfat thickness, serum total bilirubin, β‐hydroxybutyrate and the fertility found to be systematically affected by α‐amylase supplementation. 相似文献
234.
Mencke N 《Berliner und Münchener tier?rztliche Wochenschrift》2011,124(11-12):434-442
This review article summarizes the situation of canine leishmaniosis in Germany. Published case studies on infections with Leishmania (L.) infantum in either humans or dogs are analyzed. Diagnosed cases of infections by Leishmania spp. in humans and animals are not a notifiable disease in Germany or other European countries. Taking this into consideration one may assume that there might be a significant gap between the analyzed and reported cases and the infectious status within the country. The reported case studies and results from surveys indicate that the majority of all L. infantum infections are acquired during travelling in endemic regions, predominantly the Mediterranean region. However there are cases reported from human infections and growing number of cases in dogs, where the case history may indicate an autochthonous infection within Germany, a country within a non-endemic region. The current data from entomological field studies proved the presence of two phlebotomine sand fly species. Phlebotomus (P.) mascittii, an anthropophilic sand fly species and P. perniciosus a proven vector of L. infantum. The impact from a growing leishmania-positive dog population within Germany, the distribution of at least two sand fly species, one with vector potential in the light of climate change and other non-vectorial transmissions are summarized. 相似文献
235.
Ervin Rasztovits Imre Berki Csaba Mátyás Kornél Czimber Elisabeth Pötzelsberger Norbert Móricz 《Annals of Forest Science》2014,71(2):201-210
Context
Projections of species distribution models under future climate are usually based on long-term averages. However, singular extreme drought events presumably contribute to the shaping of distribution limits at the retreating low-elevation xeric limits.Methods
The objectives of this study were to set up a distribution model based on extreme drought events (EDM), which uses sanitary logging information as a proxy of vitality response of beech, and compare it with the results of classical species distribution models (SDMs).Results
Predictions of the EDM for 2025 were in agreement with those of the SDM, but EDM predicted a more serious decline in all regions of Hungary towards the end of the century.Conclusion
These results suggest that the predicted increase in frequency and severity of drought events may further limit the distribution of beech in the future. 相似文献236.
António M. Jordão Jorge M. Ricardo-da-Silva Olga Laureano An Adams Jan Demyttenaere Roland Verhé Norbert De Kimpe 《Journal of Wood Science》2006,52(6):514-521
The purpose of this study was to investigate the sorption of selected volatile substances from oak wood-chip samples (Quercus pyrenaica Willd. and Quercus petraea L.) subjected to different toasting levels, namely, without toasting, with medium toasting, and with strong toasting, through
the use of solid-phase microextraction (SPME). The main volatile compounds identified as a function of the toasting level
and botanical species were furfural, hexanal, α-pinene, d-limonene, decanal, vitispirane, ethyl hexanoate, cis-3-methyl-γ-octalactone (“oak lactone” or “whisky lactone”), α-terpineol, p-xylene, and nonanal. Considering the data obtained from the toasted woods (medium and strong intensity) in comparison with
those of nontoasted woods, it can be pointed out that the average peak area and the number of compounds identified in the
gas chromatogram decreased during the toasting process. In general, regarding the compounds analyzed, quantitative differences
were found between the two oak wood species under study. High values of volatile compounds were found in Quercus pyrenaica oak wood chips. In addition, for the number of compounds identified in oak wood extracts and directly extracted from solid
oak wood chips by SPME, it is concluded that the best extraction process for volatile compounds from oak wood is the use of
oak wood-chip liquid extracts. 相似文献
237.
Francis Mutebi Jürgen Krücken Norbert Mencke Hermann Feldmeier Georg von Samson-Himmelstjerna Charles Waiswa 《Journal of insect science (Online)》2016,16(1)
Tungiasis ensues from the penetration and burrowing of female sand fleas (Tunga spp.; Siphonaptera: Tungidae) in the skin of mammals. There are few case reports of severe tungiasis in goats and in these cases the Tunga species were not in most cases clearly identified. Two cases of severe tungiasis caused by Tunga penetrans in goat kids from tungiasis-endemic rural Uganda are reported. These are the first severe cases of tungiasis in goats reported from outside South America. 相似文献
238.
Norbert Bleier Imre Kovács Gergely Schally László Szemethy Sándor Csányi 《国际虫害防治杂志》2017,63(1):92-100
Agricultural damage caused by wild ungulates can be economically very important worldwide. In Europe, the impact of wild ungulates causes significant losses to crops, mainly to maize, where it exceeds billions of US dollars annually. The objective of this study was to explore the spatial and temporal characteristics of damage caused by wild boar and red deer to maize, in order to propose efficient prevention and mitigation of losses to agricultural producers worldwide. The study was carried out in three forests neighbouring maize fields in two different areas. We recorded data on the proportion, type and the location of the damage by ungulates within the fields. According to our results the damage varied greatly along the vegetation growth period (from green plant to corncob), likely due to the changes in the food supply provided by maize. The proportion of damaged plants increased through the growing season and was probably affected by the appearance of corncobs. Seventy to 90% of the total damage occurred within a 300 m distance to the forest edge. Considering these findings, we propose to arrange a protocol for damage prevention based on damage risk maps. 相似文献
239.
Prevalence of feline coronavirus types I and II in cats with histopathologically verified feline infectious peritonitis 总被引:3,自引:0,他引:3
Benetka V Kübber-Heiss A Kolodziejek J Nowotny N Hofmann-Parisot M Möstl K 《Veterinary microbiology》2004,99(1):31-42
Feline coronaviruses (FCoV) vary widely in virulence causing a spectrum of clinical manifestations reaching from subclinical course to fatal feline infectious peritonitis (FIP). Independent of virulence variations they are separated into two different types, type I, the original FCoV, and type II, which is closely related to canine coronavirus (CCV). The prevalence of FCoV types in Austrian cat populations without FIP has been surveyed recently indicating that type I infections predominate. The distribution of FCoV types in cats, which had succumbed to FIP, however, was fairly unknown. PCR assays have been developed amplifying parts of the spike protein gene. Type-specific primer pairs were designed, generating PCR products of different sizes. A total of 94 organ pools of cats with histopathologically verified FIP was tested. A clear differentiation was achieved in 74 cats, 86% of them were type I positive, 7% type II positive, and 7% were positive for both types. These findings demonstrate that in FIP cases FCoV type I predominates, too, nonetheless, in 14% of the cases FCoV type II was detected, suggesting its causative involvement in cases of FIP. 相似文献
240.
Meier N Meier B Banzhaf K Wittkowski G Schmitt D Truyen U 《Berliner und Münchener tier?rztliche Wochenschrift》2003,116(5-6):240-243
A total of 5204 bulk milk samples were tested for antibodies against bovine viral diarrhea virus (BVDV) classified according to the scheme after Alenius. Forty-five percent of the samples from 2002 were classified as class 0 and class 1, 55% as class 2 and 3. 6420 bulk milk samples from 1997 were classified in an independent study in 65.6% class 0 and 1 and 34.4% in class 2 and 3. In class 0 and class 1 farms only very rarely persistent viremic animals have been found, whereas in class 2 and 3 their presence is highly likely. Our studies with non-selected sera defined the serological screening of bulk milk samples as a promising tool for a possible BVDV eradication program in Bavaria. 相似文献