全文获取类型
收费全文 | 334篇 |
免费 | 31篇 |
国内免费 | 4篇 |
专业分类
林业 | 38篇 |
农学 | 9篇 |
基础科学 | 4篇 |
68篇 | |
综合类 | 31篇 |
农作物 | 15篇 |
水产渔业 | 25篇 |
畜牧兽医 | 138篇 |
园艺 | 13篇 |
植物保护 | 28篇 |
出版年
2024年 | 2篇 |
2023年 | 6篇 |
2022年 | 11篇 |
2021年 | 18篇 |
2020年 | 16篇 |
2019年 | 18篇 |
2018年 | 13篇 |
2017年 | 18篇 |
2016年 | 8篇 |
2015年 | 11篇 |
2014年 | 16篇 |
2013年 | 20篇 |
2012年 | 21篇 |
2011年 | 34篇 |
2010年 | 14篇 |
2009年 | 26篇 |
2008年 | 26篇 |
2007年 | 21篇 |
2006年 | 14篇 |
2005年 | 16篇 |
2004年 | 8篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 4篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有369条查询结果,搜索用时 16 毫秒
301.
302.
303.
Ewelina Pabjanczyk-Wlazlo Nina Tarzynska Anna Bednarowicz Adam K. Puszkarz Grzegorz Szparaga 《Marine drugs》2021,19(10)
Hyaluronate and alginate are non-toxic and biocompatible polymers, which can be used for surface modification and functionalization of many kinds of materials. Electrophoretic deposition (EPD) has several advantages, including its versatility, simplicity, and ability to coat substrates with complex shapes, and is used for the creation of antimicrobial or hydrophobic coatings on metallic biomaterials, among other applications. However, its utilization for applying biopolymer layers on textiles is very limited due to the more complex structure and spatial characteristics of fibrous materials. The aim of this research was to analyze the effects of selected EPD process parameters and the structural characteristics of fibrous carriers on the kinetics of the process and the microscopic characteristics of the deposited layers. The influence of solution characteristics, process parameters, and carrier structures obtained using two different techniques (melt blown and spun-bonded) were analyzed. The morphology and structure of the created deposits were analyzed using scanning electron microscopy and computed tomography, and molecular structure analysis was performed with Fourier Transform Infrared spectroscopy. The surface mass and thickness of fibrous poly (lactic acid)-based carriers were analyzed in accordance with the respective standards. This study serves as a basis for discussion and further development of this method with regard to fibrous materials for medical applications. 相似文献
304.
305.
Heredia-Sandoval Nina G. Granados-Nevárez María del Carmen Calderón de la Barca Ana M. Vásquez-Lara Francisco Malunga Lovemore N. Apea-Bah Franklin B. Beta Trust Islas-Rubio Alma R. 《Plant foods for human nutrition (Dordrecht, Netherlands)》2020,75(1):41-47
Plant Foods for Human Nutrition - Brewers’ spent grain (BSG) is the major by-product of the brewing industry, with great potential as a functional ingredient due to its bioactive compounds.... 相似文献
306.
Tom Bins Rodolfo Oliveira Leal Marina DomínguezRuiz Rodolfo Elvas De Carvalho Nina Fernandes Rodrigues Claire Dally JeanCharles Husson Kevin Le Boedec Juan Hernandez 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2022,36(2):515
BackgroundThe relationships among gastric lymphoid follicular hyperplasia (GLFH), Helicobacter‐like organisms (HLOs), and clinical signs have not been established in dogs.ObjectivesTo evaluate the epidemiologic, clinical, endoscopic, and histopathologic findings associated with GLFH in dogs, and determine the association of GLFH with HLOs and the French Bulldog (FB) breed.AnimalsTwo hundred eighty‐eight dogs that underwent gastroscopy between 2013 and 2016.MethodsRetrospective, cross‐sectional study. Gastric biopsy samples were reviewed and scored for inflammation and HLOs. Dogs were divided into 3 groups: group 1 (63 FBs), group 2 (45 non‐FB brachycephalic dogs), and group 3 (180 nonbrachycephalic dogs). Variables were evaluated for their association with GLFH.ResultsUnivariate analysis determined that intact males, young age, vomiting, gastroscopic findings (discoloration, hemorrhage, and ulcers), and histopathologic findings (gastric lamina propria lymphocytic infiltration and HLO score) were associated with GLFH (P ≤ .03). In the multivariate analysis, GLFH was associated with the HLO score (odds ratio [OR] > 5 for HLO scores 1‐2 and >15 for HLO score of 3; P < .001), with vomiting (OR > 4; P = .01) but not with FB breed (P = .76) and age (P = .1). The HLO score was associated with younger age (P < .001).Conclusion and Clinical ImportanceThe HLO score was associated with a high GLFH score. Vomiting was associated with GLFH. Helicobacter‐like organisms are highly prevalent in young dogs and GLFH is indirectly associated with this factor. Clinical relevance of the identification of GLFH and HLO remains to be determined. 相似文献
307.
Effects of short photoperiod on energy intake,thermogenesis, and reproduction in desert hamsters (Phodopus roborovskii)
下载免费PDF全文
![点击此处可从《Integrative zoology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Xueying ZHANG Zhijun ZHAO Nina VASILIEVA Anastasia KHRUSHCHOVA Dehua WANG 《Integrative zoology》2015,10(2):207-215
Desert hamsters (Phodopus roborovskii) are the least known species in the genus Phodopus with respect to ecology and physiology, and deserve scientific attention, particularly because of their small body size. Here, the responses of energy metabolism and reproductive function to short photoperiods in desert hamsters were investigated. Male and female desert hamsters were acclimated to either long day (LD) (L:D 16:8 h) or short day (SD) photoperiods (L:D 8:16 h) for three months, and then the females were transferred back to an LD photoperiod for a further five months, while at the end of the SD acclimation the males were killed and measurements were taken for serum leptin as well as molecular markers for thermogenesis. We found that like the other two species from the genus Phodopus, the desert hamsters under SD decreased body mass, increased adaptive thermogenesis as indicated by elevated mitochondrial protein content and uncoupling protein‐1 content in brown adipose tissue, and suppressed reproduction compared to those under LD. However, different from the other two species, desert hamsters did not show any differences in energy intake or serum leptin concentration between LD and SD. These data suggest that different species from the same genus respond in different ways to the environmental signals, and the desert adapted species are not as sensitive to change in photoperiod as the other two species. 相似文献
308.
309.
Nina Neykova Joy Obando Raimund Schneider Chris Shisanya Sören Thiele‐Bruhn Frank M. Thomas 《植物养料与土壤学杂志》2011,174(5):742-749
Intercropping is an important and widespread land‐management system in the tropics. At two agricultural sites in Central Kenya differing in elevation and soil type Haplic Nitisols (eutric) and Vitric Gleysols (eutric, epiclayic, endoclayic), we investigated the vertical root distributions using the trench wall profile method in single‐crop systems of maize (Zea mays L.) and in intercropping systems of maize and legumes (common bean, Phaseolus vulgaris L.; pigeon pea, Cajanus cajan [L.] Millsp.) to test for possible differences in the use of water and nutrient resources. The physico‐chemical soil properties of the sites were similar and imposed no restrictions to the vertical growth of the roots into soil depths of 1.4 m. The vertical distributions of the fine roots (?? 0.5–2 mm) and very fine roots (?? < 0.5 mm) were quantified by calculating the parameter β which was computed from the cumulative fraction (Y) of the root densities along the depth (d) of the soil profiles (Y = 1 – βd). We found no consistent differences between the single‐crop and the intercropping systems in the rooting depth down to 1.4 m. However, higher β values for fine roots of the intercropping systems were indicative of a more homogeneous vertical root distribution than in the single‐crop fields. In the intercropping fields, 50% of the total number of fine roots were distributed over the uppermost 36 cm of the soil, whereas in the single‐crop fields, 50% of the fine roots were concentrated in the uppermost 15–21 cm. Medium‐sized roots (?? > 2–5 mm) were detected in the intercropping fields only. The more homogeneous root distribution in the intercropping fields likely indicates a more efficient use of the limited resources nutrients and water. 相似文献
310.