全文获取类型
收费全文 | 623篇 |
免费 | 49篇 |
专业分类
林业 | 62篇 |
农学 | 11篇 |
基础科学 | 2篇 |
183篇 | |
综合类 | 43篇 |
农作物 | 42篇 |
水产渔业 | 59篇 |
畜牧兽医 | 185篇 |
园艺 | 22篇 |
植物保护 | 63篇 |
出版年
2024年 | 3篇 |
2023年 | 7篇 |
2022年 | 10篇 |
2021年 | 33篇 |
2020年 | 38篇 |
2019年 | 26篇 |
2018年 | 29篇 |
2017年 | 29篇 |
2016年 | 36篇 |
2015年 | 26篇 |
2014年 | 31篇 |
2013年 | 46篇 |
2012年 | 40篇 |
2011年 | 52篇 |
2010年 | 24篇 |
2009年 | 20篇 |
2008年 | 27篇 |
2007年 | 27篇 |
2006年 | 29篇 |
2005年 | 27篇 |
2004年 | 36篇 |
2003年 | 21篇 |
2002年 | 22篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1986年 | 3篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1977年 | 1篇 |
1975年 | 3篇 |
1964年 | 1篇 |
排序方式: 共有672条查询结果,搜索用时 15 毫秒
641.
642.
643.
Bianca Conturba Chiara Maria Lo Feudo Luca Stucchi Giovanni Stancari Lara Olivieri Francesco Ferrucci 《Veterinary dermatology》2021,32(3):290-e78
The aim of the present work was to describe a case of recurrent capillary haemangioma at the coronary border of the left front limb in a 6-month-old thoroughbred filly successfully treated with diode laser ablation and adjunctive laser photocoagulation therapy. 相似文献
644.
Fabiana Micieli Ludovica Chiavaccini Giuseppina Mennonna Giovanni Della Valle Francesco Prisco Leonardo Meomartino Giancarlo Vesce 《Veterinary anaesthesia and analgesia》2021,48(1):107-115
ObjectiveTo describe the gross and microscopic anatomy of the sciatic nerve paraneural sheath and to report an ultrasound (US)-guided subparaneural approach to the sciatic nerve in dogs, comparing two different volumes of injectate.Study designProspective, randomized, anatomical study.AnimalsA group of nine middle-sized adult Mongrel canine cadavers (18 limbs).MethodsThe sciatic nerves of three pelvic limbs of two canine cadavers were identified, exposed and isolated between the greater trochanter and the popliteal fossa for gross anatomical and microscopic examination. An additional three pelvic limbs were surgically dissected on the lateral surface of the limb; the sciatic nerves were isolated, and a 26 gauge over-the-needle catheter was inserted through the paraneural sheath under direct visualization. A methylene blue solution was then slowly injected into the subparaneural compartment through the catheter under US visualization using an 8–13 MHz linear-array transducer. Subsequently, 12 pelvic limbs (six cadavers) were randomly allocated to one of two groups; using US-guided percutaneous subparaneural approach, either 0.1 or 0.05 mL kg–1of a 1:1 solution of methylene blue and 0.5% bupivacaine was injected. The spread of the dye solution and the amount of nerve staining were macroscopically scored. The stained sciatic nerves with their sheaths were then harvested for microscopic examination.ResultsThe paraneural sciatic nerve sheath was easily identified distinct from the nerve trunk both macroscopically and with US visualization, and microscopically. Complete staining was achieved in five of six (83.3%) sciatic nerves in each group; no difference was found in the amount of staining between the two groups. Microscopically, no signs of sciatic nerve intraneural injection were observed.Conclusions and clinical relevanceThe US-guided subparaneural injection of 0.05 mL kg–1 of a dye injectate resulted in satisfactory nerve staining without evidence of sciatic nerve intraneural injection. 相似文献
645.
There is a growing interest on the potential interplay between weather, habitat, and interspecific competition on population dynamics of wild herbivores. Favorable environmental conditions may buffer the negative effects of competition; conversely, competition may be expected to be stronger under harsh environmental conditions. We investigated relationships between competitor abundance, weather, and habitat cover on density and local distribution of a medium-sized herbivore, the roe deer Capreolus capreolus, as well as its spatial overlap with fallow deer Dama dama in a Mediterranean protected area. Over 11 years (2007–2017), roe deer density was not affected by spring–summer rainfall in the previous year and decreased with increasing density of fallow deer in the previous year. Hence, over the considered temporal scale, results supported a major role of competition over weather in influencing population trends of roe deer. At a finer spatial scale, roe deer occupancy was negatively affected by local abundance of fallow deer, especially in “poorer” habitats. We found a slight support for a positive effect of fallow deer density on interspecific spatial overlap. Moreover, fine-scale spatial overlap between deer species increased with decreasing rainfall in spring–summer. Fallow deer were introduced to our study area in historical times and their role as superior competitors over roe deer has been found also in other study areas. We suggest a potential role of harsh weather conditions during the growing season of vegetation (i.e. scarce rainfall) in triggering the potential for ecological overlap, emphasizing the negative effects of interspecific competition. 相似文献
646.
Alessandra Marti Alberto Barbiroli Francesco Bonomi Andrea Brutti Stefania Iametti Mauro Marengo Matteo Miriani Maria Ambrogina Pagani 《Cereal Chemistry》2014,91(4):318-320
The ability of high hydrostatic pressure processing to promote changes in both the structural properties of fiber and the interaction of fiber with water were addressed. Both coarse and fine bran from milling of common wheat were considered. Treatment‐induced morphological changes were most pronounced in fine bran, whereas treatment of coarse bran resulted in the largest change in water‐holding capacity. The significance of the process‐induced changes is discussed in terms of their practical relevance in the production of fiber‐enriched foods. 相似文献
647.
648.
Enrico Bigliardi Carla Bresciani Daniela Callegari Francesco Di Ianni Giorgio Morini Enrico Parmigiani Ezio Bianchi 《Journal of veterinary science (Suw?n-si, Korea)》2014,15(2):267-271
Insulin resistance (IR) in dogs is suspected when hyperglycemia is present despite administration of insulin doses greater than 1.0 to 1.5 UI/kg. IR is caused by increases in counter regulatory hormones concentrations (glucagon, glucocorticoids, catecholamines and growth hormone). This study was conducted to investigate the use of aglepristone (RU 46534), a P4 receptor antagonist, for the treatment of IR diabetes mellitus in bitches during the luteal phase. All animals were treated with porcine insulin zinc suspension (Caninsulin) and aglepristone (Alizin) 10 mg/kg subcutaneously at day 1, 2, 9 and 17 from diagnosis. At day 5, no significant variation in glycemia was shown. At day 12 and 20, serum glucose concentrations were significant lower (p < 0.05). From day 12 the insulin dose was reduced to 0.8 IU BID. Insulin was reduced in the following weeks and glycemia was controlled. 相似文献
649.
Alessio Fini Francesco Ferrini Martina Di Ferdinando Cecilia Brunetti Cristiana Giordano Francesca Gerini Massimiliano Tattini 《Urban Forestry & Urban Greening》2014,13(1):63-70
Cultivation techniques in the nursery aimed to improve tolerance to abiotic stresses after planting in the landscape may have great ecological value. Here we tested the hypothesis that the irradiance at which plants grow in the nursery may impact on their responses to a subsequent drought stress. Measurements of relevant morpho-anatomical, physiological and biochemical traits were conducted in Fraxinus ornus, a member of the Oleaceae family of increasing interest as an urban tree. Leaves developed under moderate shade displayed a lower ability to preserve water balance, thus suffering from a greater decline in net CO2 assimilation than leaves acclimated to full sunlight, when subsequently exposed to drought stress. Shaded leaves also displayed an inherently lower capacity to dissipate excess radiant energy through nonphotochemical quenching, thus suffering from greater oxidative damage than sun leaves under drought. These results indicate that sunlight irradiance at which container-grown ash trees grow in the nursery may tightly affect the tolerance to subsequent drought stress. This may have great value for enhancing the establishment of container-grown plants in the landscape, as fully leaved plants may suffer from severe drought stress during early stages of acclimation in the landscape. 相似文献
650.
Cinzia Podda Francesco Palmas Giacomo Frau Giovanna Chessa Jacopo Culurgioni Riccardo Diciotti Nicola Fois Andrea Sabatini 《水产资源保护:海洋与淡水生态系统》2020,30(8):1638-1648
- The European eel, Anguilla anguilla, is a catadromous and migratory species of commercial importance. Its complex life cycle results in its exposure to many risk factors, which have resulted in stock declines across all life stages since the 1970s.
- The temporal recruitment dynamics of juvenile eels (glass eels and elvers) were investigated in a small Mediterranean estuary (Sardinia, Italy). The composition of the population and the monthly and seasonal variations in the abundances of juvenile eels was assessed over 78 sampling events (from February 2017 to February 2018). Furthermore, the effects of abiotic variables on the abundances of glass eels and elvers were investigated using generalized additive models (GAMs).
- Glass eels had the greatest abundance during the winter months, whereas elvers had the greatest abundance during spring. Modelling revealed that the abundance of glass eels was mostly explained by the combined effects of water temperature (12.3–14.5 °C), tidal coefficient (40–110 cm), moon phase, season, and river mouth condition, whereas the abundance of elvers was associated with water temperature (14–21 °C), dissolved oxygen content (>7 mg/L), and season. These results suggest that the annual recruitment of juvenile eels occurs throughout the year, with clear seasonal migration dynamics.
- The use of multiple statistical approaches allowed us to identify the importance of several environmental variables in regulating the recruitment dynamics, providing useful information for conserving eel stocks through the restoration of the natural flow regime and the connectivity between freshwater habitats and the sea.