全文获取类型
收费全文 | 563篇 |
免费 | 39篇 |
国内免费 | 2篇 |
专业分类
林业 | 35篇 |
农学 | 17篇 |
基础科学 | 4篇 |
174篇 | |
综合类 | 34篇 |
农作物 | 49篇 |
水产渔业 | 40篇 |
畜牧兽医 | 194篇 |
园艺 | 18篇 |
植物保护 | 39篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 8篇 |
2021年 | 14篇 |
2020年 | 18篇 |
2019年 | 11篇 |
2018年 | 28篇 |
2017年 | 22篇 |
2016年 | 26篇 |
2015年 | 11篇 |
2014年 | 23篇 |
2013年 | 38篇 |
2012年 | 38篇 |
2011年 | 61篇 |
2010年 | 43篇 |
2009年 | 24篇 |
2008年 | 37篇 |
2007年 | 36篇 |
2006年 | 34篇 |
2005年 | 28篇 |
2004年 | 25篇 |
2003年 | 15篇 |
2002年 | 20篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 1篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1983年 | 2篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 3篇 |
排序方式: 共有604条查询结果,搜索用时 490 毫秒
101.
Jose Manuel Vilar Franscisco Doreste Giuseppe Spinella Simona Valentini 《Journal of Equine Veterinary Science》2009
The objective of this retrospective study is to describe a surgical technique to correct large, recurrent, incisional hernias in horses using a polypropylene mesh. The study sample included 15 horses with large hernias (range, 16−43 cm in length) developed after failure of previous abdominal closure. A double-layer polypropylene mesh was inserted between the internal rectus abdominis muscle sheath and peritoneum. Wound healing was assessed using clinical and ultrasonographic examinations. During a follow-up period of 6 months, no major complications related to the surgical procedure were observed. Subfascial retroperitoneal insertion of a double-layer polypropylene mesh is a valuable treatment option in cases of large and complicated incisional hernias in horses. 相似文献
102.
Antonio Santaniello Laura Rinaldi Lucia Francesca Menna Giuseppe Cringoli Alessandro Fioretti 《Research in veterinary science》2009,87(1):67-71
Rabbit sera (n = 1600) from 40 commercial farms were submitted to a serological screening for Encephalitozoon cuniculi by an enzyme-linked immunosorbent assay (ELISA) and a carbon immunoassay (CIA test). Antibodies anti-Encephalitozoon cuniculi were found in 505/1600 (31.6%) sera analysed, and all the farms (100%) resulted positive. Rabbits older than 4 months showed a significantly higher seropositivity for E. cuniculi (chi-squared test: p < 0.0001) than rabbits under 4 months, E. cuniculi sero-prevalence showed an increasing trend in rabbits within the farm along with the increase in the “number of rabbits on the farm”; however, this trend was not significant (Spearman’s correlation: p = 0.073).The findings of the present study confirm that rabbit is the main reservoir of E. cuniculi; they are of epidemiological relevance and immediate public health importance because of the recognized infectivity in humans by the microsporidium. 相似文献
103.
104.
We evaluated the osmotic adjustment capacity of leaves and roots of young olive (Olea europaea L.) trees during a period of water deficit and subsequent rewatering. The trials were carried out in Basilicata (40 degrees 24' N, 16 degrees 48' E) on 2-year-old self-rooted olive plants (cv. 'Coratina'). Plants were subjected to one of four drought treatments. After 13 days of drought, plants reached mean predawn leaf water potentials of -0.45 +/- 0.015 MPa (control), -1.65 +/- 0.021 (low stress), -3.25 +/- 0.035 (medium stress) and -5.35 +/- 0.027 MPa (high stress). Total osmotic adjustment increased with increasing severity of drought stress. Trees in the high stress treatment showed total osmotic adjustments ranging between 2.4 MPa at 0500 h and 3.8 MPa at 1800 h on the last day of the drought period. Osmotic adjustment allowed the leaves to reach leaf water potentials of about -7.0 MPa. Active osmotic adjustment at predawn decreased during the rewatering period in both leaves and roots. Stomatal conductance and net photosynthetic rate declined with increasing drought stress. Osmotic adjustment in olive trees was associated with active and passive osmotic regulation of drought tolerance, providing an important mechanism for avoiding water loss. 相似文献
105.
Cefarelli G D'Abrosca B Fiorentino A Izzo A Mastellone C Pacifico S Piscopo V 《Journal of agricultural and food chemistry》2006,54(3):803-809
Forty-three secondary metabolites were isolated and characterized from cv. Annurca apple fruit, an apple variety cultivated in the south of Italy. This apple cultivar undergoes a typical reddening treatment after collection. All of the compounds were characterized on the basis of their spectroscopic data. The compounds were tested for their radical-scavenging and antioxidant activities by measuring their capacity to scavenge DPPH* (2,2'-diphenyl-1-picrylhydrazyl radical), H2O2, and NO (nitric oxide) and to inhibit the formation of methyl linoleate conjugated diene hydroperoxides or TBARS (thiobarbituric acid reactive species). 相似文献
106.
Mandalari G Bennett RN Bisignano G Saija A Dugo G Lo Curto RB Faulds CB Waldron KW 《Journal of agricultural and food chemistry》2006,54(1):197-203
Bergamot peel is an underutilized byproduct of the essential oil and juice-processing industry. As with other Citrus peels, it still contains exploitable components, such as pectins and flavonoids. Commercial glycoside hydrolases, specifically a combination of pectolytic and cellulolytic enzymes, solubilized a high percentage of the material (81.94%). The flavonoid profile of the peel consisted of characteristic Citrus species flavanone rutinosides and neohesperosides derived from naringenin, eriodictyol, and hesperetin. In addition, a number of minor flavanone and flavone glycosides, not found in orange and lemon peels, were identified. The majority of flavonoids were extracted in the two 70% v/v EtOH extractions. Processing this material clearly has economic potential leading to low environmental impact. 相似文献
107.
Soledad Martos Anna Andolfi Jordi Luque Laura Mugnai Giuseppe Surico Antonio Evidente 《European journal of plant pathology / European Foundation for Plant Pathology》2008,121(4):451-461
In recent years an increasing number of species of Botryosphaeriaceae have been associated with grapevine decline worldwide.
Five species isolated from declining grapevines in Spain (Botryosphaeria dothidea, Diplodia seriata, Dothiorella viticola, Neofusicoccum luteum and N. parvum) were checked for toxin production in liquid cultures. Cultural conditions for all fungi were adjusted to obtain optimal
production of phytotoxic culture filtrates, by growing the fungi in steady liquid cultures of Czapek–Dox broth for different
time intervals. Phytotoxicity of D. seriata and N. parvum reached a maximum after 14 days while the remaining species showed the highest phytotoxicity levels after 21 days in culture.
All fungi produced hydrophilic high-molecular weight compounds with phytotoxic properties. In addition, N. luteum and N. parvum produced lipophilic low-molecular weight phytotoxins, not detected consistently among the remaining species. This led to
a more exhaustive study on the phytotoxicity of N. luteum and N. parvum. Culture filtrates and corresponding extracts of both species were consistently highly phytotoxic in different assays. The
gas-chromatography analysis of the acetylated O-methyl glycosides of the phytotoxic exopolysaccharides produced by N. parvum showed these substances to be composed mainly of glucose, mannose and galactose. Results suggest that phytotoxic metabolites
could be involved in the virulence of both species in planta. 相似文献
108.
Gianluigi Mazza Alessandro Elio Agnelli Maria Costanza Andrenelli Alessandra Lagomarsino 《Archives of Agronomy and Soil Science》2018,64(5):654-667
GHGs production and emission may vary depending on soil physical properties, water management and fertilization. Two paddy soils characterized by different texture were incubated to evaluate the impact of flooding (permanent or intermittent) and N addition on potential N2O, CH4 and CO2 production and release into atmosphere and soil solution. Relationships with volumetric water content (VWC) and water filled pore space (WFPS) were evaluated. Overall, the finer clayey soil (CL) produced 58% more CH4 than the coarser sandy soil (SA) and showed an earlier sink to source transition; the difference was lower with N addition. Permanent flooding favoured the amount of dissolved CH4. SA produced more N2O emissions than CL under permanent flooding (31.0 vs. 3.7%); an opposite pattern was observed for dissolved N2O (16.4 vs. 52.7%). Fertilization increased N2O emissions under dry conditions in CL and under flooding in SA.
Our findings showed that i) VWC had a larger influence on N2O and CH4 emissions than WFPS, ii) soil type influenced the gas release into atmosphere or soil solution and the timing of sink to source transition in CH4 emissions. Further investigation on timing of fertilization and drainage are needed to improve climate change mitigation strategies. 相似文献
109.
Catello Pane Gianluca Francese Francesco Raimo Giuseppe Mennella Massimo Zaccardelli 《European journal of plant pathology / European Foundation for Plant Pathology》2017,148(3):687-697
Antifungal activity of plant-derived compounds can be exploited in disease management systems to improve sustainability and replace synthetic molecules. In this study, four crude hydroethanolic extracts of leaves, collected from Italian Solanum spp. landraces, were selected to evaluate their ability to suppress Sclerotinia minor Jagger, a great threat to lettuce production worldwide. In vitro fungal development was inhibited by Solanum melongena L. and S. aethiopicum L. extracts showing a dose-dependent correlation. At the highest concentration tested in the current experiments (45 mg mL?1) antifungal activity caused up to 90% growth reduction. The exposure of the fungus to S. aethiopicum extracts incited pronounced changes in the hyphal morphology as observed under light microscopy. Consistently, under laboratory conditions, in planta application of the active extracts on lettuce significantly reduced Sclerotinia drop disease in comparison to non-treated controls. Phytochemical composition was determined by liquid chromatography/mass spectrometry (LC/MS) analyses. Four secondary metabolites differentially present in the extracts, identified as n-caffeoylputrescine, chlorogenic acid, isoquercitrin and solasodoside A, are hypothesized to play a crucial role in mechanisms underlying biological effects of extracts. PCA analysis showed positive correlations of these compounds with the overall control ability of the extracts. The results indicated that foliar material from cultivated eggplant could be suitable to produce biological-based remedies for controlling plant diseases. 相似文献
110.
Synthesis,theoretical studies,and effect on the photosynthetic electron transport of trifluoromethyl arylamides 下载免费PDF全文