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排序方式: 共有182条查询结果,搜索用时 15 毫秒
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Charles M. Adams Sherry L. Larkin Donna J. Lee 《Aquarium Sciences and Conservation》2001,3(1-3):25-36
The marine life fishing industry in Florida is defined by the state as the non-lethal harvest of marine plants, finfish, and invertebrates that are sold live for commercial purposes (primarily into the saltwater aquarium industry). Approximately 330 different species of finfish and invertebrates are harvested by marine life collectors in Florida, including 180 species of finfish and 150 species of invertebrates and plants. In 1998, the total dockside value of these species was approximately US$1.9 million. The industry is highly regulated via limits on gear, handling methods, harvest sizes, and trip/bag/possession limits. Entry into the industry has been recently curtailed by the implementation of a moratorium on marine life endorsements. The total number of licensed harvesters exceeded 700 in 1998. Approximately 70 wholesales buyers also participated in the market during 1998. The majority of the dockside value is generated in south Florida, with the majority of the remaining value accruing from the region including and north of Tampa Bay. Over 80% of the total value associated with both finfish and invertebrates is generated by only 10 species within each group. Dockside prices vary considerably among the various species landed, with those landed in greater volumes exhibiting the lower prices. 相似文献
13.
Constructed ponds are an important consideration in the conservation of wetland biota in agricultural landscapes. Twenty-two natural ponds and 22 adjacent constructed ponds (farm dams) were surveyed on the Southern Tablelands of New South Wales to compare patterns of use by frogs and develop frog conservation recommendations. Farm dams supported similar numbers of frog species to natural ponds, although differences in frog assemblage were observed between the pond types. Limnodynastes tasmaniensis and Uperolia laevigata were significantly more likely to occur at farm dams while L. peronii was more likely to occur at natural ponds. Results suggest waterbodies with high levels of emergent vegetation cover that lack fish are likely to support a high number of frog species, regardless of origin (i.e. natural or constructed). However, it is important for landholders to conserve natural waterbodies as these environments appear likely to support frog species that do not use farm dams. 相似文献
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OBJECTIVE: To assess the use of folic acid supplementation in relation to small-area measures of social deprivation. DESIGN: Cohort study. SETTING: Antenatal clinic, Women's Outpatients Services, Cumberland Infirmary, Carlisle, UK. SUBJECTS: Four hundred and fifty women attending their 18-week antenatal clinic appointment. No selection criteria were applied. Townsend scores were allocated using postcodes to provide a small-area measure (enumeration district) of social deprivation. RESULTS: Eighty-nine per cent of women took folic acid prior to their 18-week antenatal clinic appointment; 48% of women took folic acid before 4 weeks of gestation. Younger women and more socially deprived women were less likely to use folic acid supplements before 4 weeks of gestation. Women with a family history of neural tube defects were no more likely to take folic acid than were women with no family history of neural tube defects. CONCLUSION: A high proportion of women reported taking folic acid supplements during pregnancy but less than half took them at the most important time in early pregnancy. Younger women and women who were more socio-economically deprived were much less likely to take folic acid during the critical periconceptional period. Future strategies should promote prenatal folic acid supplementation in women under the age of 24 and in women of low socio-economic status. Further attention should also be given to the use of folic acid supplements in women with a family history of neural tube defects. 相似文献
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Fekete DM 《Science (New York, N.Y.)》2003,302(5643):241-242
The vestibular organs of the inner ear of higher vertebrates control balance, and their counterparts in fish control both balance and hearing. Essential to the operation of these sensory organs are the biomineralized structures--otoconia in higher vertebrates or otoliths in fish--that deflect the sensory hair bundles situated beneath them. In her Perspective, Fekete explores the fascinating world of otolith biomineralization in zebrafish; revealing the importance of a protein called Starmaker for coordinating the shape and type of crystal in fish otoliths ( S?llner et al.). 相似文献
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All transgenic cultivars of potatoes registered in Canada and the United States have been modified to express a synthetic cry3A gene as a means of conferring resistance against the Colorado potato beetle, an important economic pest of potatoes. A PCR method was developed to amplify a 499 bp region of the synthetic cry3A gene. Using this method, synthetic cry3A could be detected in six different transgenic cultivars. Positive results could be confirmed with PvuII restriction digestion of the PCR-generated amplicon, which resulted in two fragments that were 283 and 216 bp in size. Of the 52 tuber extracts tested with this method, no false positive or false negative results were obtained, suggesting the method could be used with a high degree of accuracy. The absolute limit of detection was the number of cry3A copies present in one or perhaps two haploid copies of the potato genome. The practical limit of detection in tubers on a fresh weight basis was 0.02% for the NL 10-SUP and 0.01% for the remaining cultivars. Synthetic cry3A could also be detected in processed food products such as potato chips, shoestring potatoes, and frozen French fries. The method was suitable for screening potato tuber lots and some processed foods for the presence of synthetic cry3A. 相似文献
19.
Victor I. Okereke E. Robert Baumann T. Al Austin Donna Schulze Lutz 《Water, air, and soil pollution》1988,37(3-4):325-341
The impact of a flood control, low flow argumentation reservoir in the Midwestern part of the United States on BOD, COD, and ammonia was evaluated in this paper. Fifteen years of weekly water quality data (9 yr before impoundment and 6 yr after impoundment) from four sampling stations upstream and downstream of the reservoir were available for analysis. The annual loading rates of these parameters (kg ha?1 vr?1) were found to correlate well with annual runoff (cm yr?1). Besides, the reservoir was found to have had a significant and beneficial impact on the downstream loading rates of BOD and COD, which were reduced by 55 and 75%, respectively. As for ammonia, the results of this study indicate that its annual loadings at downstream locations were not significantly affected by the reservoir. Average non-point source contributions of BOD and ammonia loadings into the system were found to be about 80 and 55%, respectively. 相似文献
20.
Vinson JA Proch J Bose P Muchler S Taffera P Shuta D Samman N Agbor GA 《Journal of agricultural and food chemistry》2006,54(21):8071-8076
Chocolate today is often viewed as a food or snack with little nutritional value. The high saturated fat content of chocolate has also contributed to the belief that its consumption increases the risk of heart disease. However, recent human studies have proven that chocolate has beneficial effects on some pathogenic mechanisms of heart disease such as endothelial function and blood pressure. Although the antioxidant properties of chocolate have been known for some time, there has been no examination of its place in the U.S. diet as a source of antioxidants. This paper demonstrates that chocolate makes a significant contribution to U.S. per capita dietary antioxidants and by inference the European Community's. In the U.S. diet chocolate is the third highest daily per capita antioxidant source. An ex vivo study shows that epicatechin, a major polyphenol in chocolate and chocolate extracts, is a powerful inhibitor of plasma lipid oxidation due to polyphenols' ability to bind to lower density lipoproteins. Conversely, the fat from chocolate alone is a pro-oxidant in this model. This is also demonstrated in an in vivo human study. After consumption of dark chocolate and cocoa powder, the lower density lipoproteins isolated from plasma were protected from oxidation compared to the lipoproteins isolated after cocoa butter consumption, which were put under oxidative stress. In an animal model of atherosclerosis, cocoa powder at a human dose equivalent of two dark chocolate bars per day significantly inhibited atherosclerosis, lowered cholesterol, low-density lipoprotein, and triglycerides, raised high-density lipoprotein, and protected the lower density lipoproteins from oxidation. Chocolate has thus been shown to have potential beneficial effects with respect to heart disease. 相似文献