全文获取类型
收费全文 | 145篇 |
免费 | 5篇 |
专业分类
林业 | 13篇 |
农学 | 2篇 |
基础科学 | 1篇 |
35篇 | |
综合类 | 15篇 |
农作物 | 8篇 |
水产渔业 | 17篇 |
畜牧兽医 | 40篇 |
园艺 | 4篇 |
植物保护 | 15篇 |
出版年
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 6篇 |
2018年 | 5篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 6篇 |
2012年 | 5篇 |
2011年 | 8篇 |
2010年 | 7篇 |
2009年 | 5篇 |
2008年 | 10篇 |
2007年 | 6篇 |
2006年 | 5篇 |
2005年 | 7篇 |
2004年 | 18篇 |
2003年 | 8篇 |
2002年 | 4篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1960年 | 1篇 |
1959年 | 1篇 |
1958年 | 1篇 |
1957年 | 1篇 |
1940年 | 1篇 |
1938年 | 1篇 |
排序方式: 共有150条查询结果,搜索用时 15 毫秒
51.
New perspectives on aquarium fish trade 总被引:1,自引:0,他引:1
David Lecchini Sandrine Polti Yohei Nakamura Pascal Mosconi Makoto Tsuchiya Georges Remoissenet Serge Planes 《Fisheries Science》2006,72(1):40-47
ABSTRACT: Since the 1990s, the international market for importing aquarium fish is suspicious of stock coming from South-East Asia. Fish catches are still executed with cyanide-based toxic products. In the present paper, the potential of the French Polynesian Islands to develop a marine aquarium fish business with a new approach is explored. Coral reef fish are captured at the larval stage with crest nets, then larvae are reared in aquaria before being put on the world ornamental fish market. This approach offers several advantages: (i) larvae are captured with a passive system placed on the reef crest (crest net) that does not destroy the environment and limits the stress on collected larvae; (ii) larvae are then put into farmed basins that allow them to be controlled sanitarily; and (iii) larvae are weaned at the farm and fed rapidly with artificial food. This method increases survival rates as it eliminates the food acclimatization problem of fish captured at adult stage (main cause of fish mortality in aquaria). Overall, reared larvae will constitute a new product in terms of species, sizes and quality of ornamental fish on the aquarium market. 相似文献
52.
This paper presents the findings of an exploratory study on ethnoveterinary medicines used for backyard pigs and backyard chickens in Trinidad and Tobago. Research data was collected from 1995 to September 2000. Six plants are used for backyard pigs. Crushed leaves of immortelle (Erythrina pallida, E. micropteryx) are used to remove dead piglets from the uterus. Leaf decoctions of bois canôt (Cecropia peltata) and bamboo (Bambusa vulgaris) are used for labour pains or leaves are fed as a postpartum cleanser. Boiled green papaya fruit (Carica papaya) is fed to pigs to induce milk let-down. The leaves and flowers of male papaya plants (Carica papaya) are fed to de-worm pigs. Sour orange juice (Citrus aurantium) is given to pigs to produce lean meat, and coffee grounds are used for scours. Eyebright and plantain leaves (Plantago major) are used for eye injuries of backyard chickens. Worm grass (Chenopodium ambrosioides) and cotton bush (Gossypium species) are used as anthelmintics. Aloe gel (Aloe vera) is used for internal injuries and the yellow sap from the cut Aloe vera leaf or the juice of Citrus limonia is used to purge the birds. A literature review revealed few toxicity concerns and the potential usefulness of the plants. 相似文献
53.
Declercq G 《Science (New York, N.Y.)》2005,310(5754):1618; author reply 1618
54.
Georges Vulsteke André Calus 《Plant foods for human nutrition (Dordrecht, Netherlands)》1990,40(2):149-166
In the period 1983–1986, research was carried out into the inulin content of scorzonera during ripening and storage. Since the inulin content is determining for the occurrence of crystallisation with canned scorzonera, the effects of the varieties, the time of harvest and storage of the scorzonera were investigated.The changing of the inulin content on the conversion into reducing sugars was checked; the effect of the dry matter and nitrate content were also defined.The aim was to define whether the determination of the inulin content was a useful parameter for the ripening of the scorzonera. On the whole, the different varieties showed remarkable difference where fructosanes+inulin, as well as pure inulin, were concerned.A significant decrease of the inulin content was obtained from the middle of November, by so far that it was below the limit above which crystallisation takes place.A two-month storage period of scorzonera harvested in early October also led to a very low inulin content, so that no problems could occur while canning. Storage conditions of the scorzonera seemed of importance too.The nitrate content of the different scorzonera varieties was low, although some variations were noted. The crops harvested in early December showed considerably lower contents when compared to those harvested in early October or mid-November.The inulin content as well as the content of reducing sugars are a useful parameter to determine the maturity of the scorzonera.This research was subsidized by the Instituut tot Aanmoediging van het Wetenschappelijk Onderzoek in Nijverheid en Landbouw (I.W.O.N.L.). 相似文献
55.
Georges Kunstler Robert B. Allen David A. Coomes Charles D. Canham Elaine F. Wright 《Annals of Forest Science》2013,70(3):287-298
Context
There is strong interest in sustainable forest management systems that preserve characteristics of forests close to naturalness. Assessing the effectiveness of these systems is difficult because defining “natural” baselines from which impacts are estimated is challenging and because the influence of harvesting can have complex interactions with major natural disturbances.Aims
We used SORTIE/NZ, an individual tree-based forest dynamics model, to understand how harvesting and earthquake disturbance affect the dynamics of a New Zealand podocarp–angiosperm forest.Methods
Having parameterized SORTIE/NZ with extensive field data, we ran simulations for three natural dynamics scenarios (no disturbance and two earthquake scenarios) and then added podocarp harvesting scenario to each of these.Results
Simulations suggest that this forest is experiencing transient dynamics, with a natural rise in the dominance of one species of slow-growing podocarp with and without earthquake. Harvesting podocarps strongly affected its increase in basal area.Conclusion
Our results indicate that transient dynamics may occur in mixed podocarp forests and major disturbances may have complex interactions with management. Evaluating management impacts without accounting for these complex dynamics may be misleading. Models make predictions about transient trajectories that may help to evaluate these impacts. 相似文献56.
François Allal Georges Piombo Bokary A. Kelly John B. L. Okullo Massamba Thiam Ousmane B. Diallo George Nyarko Fabrice Davrieux Peter N. Lovett Jean-Marc Bouvet 《Agroforestry Systems》2013,87(5):1065-1082
The shea tree, Vitellaria paradoxa, is one of the most economically and culturally important indigenous tree species in the Sudano-Sahelian region. Its seeds contain a vegetable fat, internationally known as shea butter, which is widely used in edible, cosmetic and pharmaceutical sectors. Based on samples from 456 trees distributed in 17 locations across the species natural range from Senegal to Uganda, the fatty acid and tocopherol variation, and its relationship with geographic and climatic variables, was assessed in order to address the pattern and the origin of this variation across the natural range. Significant differences between Western and Eastern regions for oleic, stearic acid, saturated–unsaturated acid ratio and γ-tocopherol were identified that it is postulated maybe a result of genetic drift due to the evolutionary history of shea tree populations. Within regions the difference among stands was significant for most constituents; however the major part of the variation was observed among trees within stand (53–90 %). Relationships with climatic variables were not verified, weakening evidence for clinal variation hypotheses suggested by previous studies. 相似文献
57.
58.
R. Lavoué J.J. Van Der Lugt M.J. Day M. Georges V. Busoni A.C. Merveille A. Poujade D. Peeters 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2010,24(2):314-322
Background: Familial juvenile glomerulonephropathy (JGN) is reported in several breeds of dogs. The mode of inheritance and spectrum of pathological lesions vary among breeds. A progressive JGN was detected in a pedigree of French Mastiff (FM) dogs. Objectives: To describe clinical, laboratory, and histopathologic findings in related FM dogs suffering from progressive JGN and to determine the mode of inheritance of this condition. Animals: Sixteen affected and 35 healthy related FM dogs Methods: FM dogs <24 months of age and diagnosed with chronic kidney disease with evidence of proteinuria entered the study. Clinical, laboratory, histopathologic findings, and pedigree data were recorded. Results: Clinical signs were typical of progressive glomerulopathy with resultant renal failure. Increased blood urea nitrogen, creatinine and total cholesterol concentrations, and proteinuria were found in all patients. Affected dogs had abnormal kidney structure on abdominal ultrasound examination. Histopathologic examination revealed extensive cystic glomerular atrophy, glomerular hypercellularity, and capillary wall thickening without immune complex deposition when tested with immunohistochemistry or immunofluorescence. Electron microscopy did not disclose specific primary glomerular lesions. Mean age at death was 20 months and mean length of survival after diagnosis was 6 months. Both males and females from healthy parents were affected. An autosomal recessive mode of transmission is suspected, but a more complex mode of inheritance cannot be excluded. Conclusions and Clinical Importance: Progressive familial JGN occurs in FM dogs. Characterization of the pathogenesis and mode of inheritance of this disease warrants additional study. 相似文献
59.
Enrichment of anhydrous milk fat in polyunsaturated fatty acid residues from linseed and rapeseed oils through enzymatic interesterification 总被引:1,自引:0,他引:1
Aguedo M Hanon E Danthine S Paquot M Lognay G Thomas A Vandenbol M Thonart P Wathelet JP Blecker C 《Journal of agricultural and food chemistry》2008,56(5):1757-1765
Lipozyme TL IM was used in a solvent-free batch and microaqueous system for enzymatic interesterification of anhydrous milkfat (AMF) with linseed oil (LO) in binary blends and with rapeseed oil (RO) in one ternary blend. The aim was to obtain and characterize physicochemically fats enriched with unsaturated C 18 fatty acids (oleic, linoleic, and, especially, linolenic acids) from natural vegetable oils. Binary blends of AMF/LO 100/0, 90/10, 80/20, 70/30, and 60/40 (w/w) were interesterified. The change in triacylglycerol (TAG) profiles showed that quasi-equilibrium conditions were reached after 4-6 h of reaction. Free fatty acid contents <1%. The decrease in solid fat content and in dropping point temperature obtained with increasing content of LO and interesterification resulted in good plastic properties for the products originating from the blends 70/30 and 60/40. This was confirmed by textural measurements. Melting profiles determined by differential scanning calorimetry showed complete disappearance of low-melting TAGs from LO and the formation of intermediary species with a lower melting temperature. Oxidative stability of the interesterified products was diminished with increasing LO content, resulting in low oxidation induction times. A ternary blend composed of AMF/RO/LO 70/20/10 gave satisfactory rheological and oxidative properties, fulfilling the requirements for a marketable spread and, moreover, offering increased potential health benefits due to the enriched content in polyunsaturated fatty acid residues. 相似文献
60.
Georges Choubert José-Carlos G. Milicua Ramon Gomez Sophie Sancé Hélène Petit Geneviève Nègre-Sadargues René Castillo Jean-Paul Trilles 《Aquaculture International》1995,3(3):205-216
Rainbow trout (Oncorhynchus mykiss) with a mean (sd) weight of 120 (2) g were fed diets supplemented with astaxanthin extracted from the yeast Phaffia rhodozyma (OY1 = 50 mg carotenoids kg–1 feed, OY2 = 100 mg carotenoids kg–1 feed), astaxanthin (AX = 100 mg astaxanthin kg–1 feed) and canthaxanthin (CX = 100 mg canthaxanthin kg–1 feed) for 4 weeks. Muscle analyses at the end of the experiment indicated a significantly higher carotenoid concentration in the AX group, while CX and OY1 groups were similar in spite of the differences in dietary concentration. The measure of total muscle colour difference (E*
ab) between initial samples and 4 week ones was higher for the AX fish group but showed no significant difference between OY1, OY2, and CX. The hue and the reflectance ratio (R650:R510) of fish muscle increased in proportion to carotenoid intake. Digestibility (ADC) of yeast astaxanthin in OY1 and OY2 groups was significantly higher than that in the AX group. Canthaxanthin ADC was about one sixth of that of astaxanthin (AX group). Carotenoid retention in the muscle, expressed as a percentage of carotenoid intake, was higher for the AX group than that recorded for OY1 and OY2. According to ADC, carotenoid retention showed a marked lower value for the CX group. Muscle retentions were similar for astaxanthins from both sources. 相似文献