全文获取类型
收费全文 | 368篇 |
免费 | 15篇 |
专业分类
林业 | 7篇 |
农学 | 7篇 |
基础科学 | 2篇 |
37篇 | |
综合类 | 88篇 |
农作物 | 42篇 |
水产渔业 | 6篇 |
畜牧兽医 | 176篇 |
园艺 | 6篇 |
植物保护 | 12篇 |
出版年
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 3篇 |
2014年 | 6篇 |
2013年 | 25篇 |
2012年 | 9篇 |
2011年 | 10篇 |
2010年 | 8篇 |
2009年 | 5篇 |
2008年 | 10篇 |
2007年 | 13篇 |
2006年 | 7篇 |
2005年 | 9篇 |
2004年 | 11篇 |
2003年 | 4篇 |
2002年 | 7篇 |
2001年 | 10篇 |
2000年 | 13篇 |
1999年 | 7篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1994年 | 6篇 |
1993年 | 5篇 |
1992年 | 13篇 |
1991年 | 11篇 |
1990年 | 5篇 |
1988年 | 7篇 |
1987年 | 3篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 9篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1979年 | 12篇 |
1978年 | 9篇 |
1977年 | 4篇 |
1975年 | 3篇 |
1974年 | 7篇 |
1973年 | 7篇 |
1972年 | 5篇 |
1971年 | 12篇 |
1970年 | 10篇 |
1969年 | 7篇 |
1967年 | 3篇 |
1966年 | 5篇 |
1960年 | 3篇 |
1955年 | 3篇 |
排序方式: 共有383条查询结果,搜索用时 15 毫秒
141.
Potatoes with high-reducing sugar content taken directly from cold storage (4.5 C) and cut into 3/8-inch-square, 3-inch-long strips, were immersed in liquid nitrogen or dichlorodifluoromethane (?30.5 C or?79 C) for 3 to 15 sec and then leached for 5 min in water at 50 C. It was found that by using this method of freezing and leaching light colored strips could be finish-fried from Red La Soda, Russet Burbank, and Norchip varieties without conditioning. Finished-fries prepared by water-leaching only were usually too dark. 相似文献
142.
143.
Initial swelling and early tuber enlargement are the result of cell enlargement at a rate surpassing addition of new storage cells. New phloem strands are added by procambial activity. New storage cells are formed marginal to the phloem strands. Frequency of divisions in these new cells rapidly decreases. Tubers in which mitotic processes are compapratively restricted in early stages of development are slow growers; i.e., cell enlargement proceeds with fewer cells present. Tubers in which more phloem strands and associated cells have been added in early growth are rapid growers and contain more enlarging cells. Reduction in mitotic rate concurrently with increased cell enlargement progresses radially from each phloem strand in young tubers. Cell divisions are rare in all young storage tissues by the time a tuber has attained a size of 30 to 40 g, except in the immediate sites of “eye” buds. Some cell divisions are nececssary for phloem strands to keep pace with tuber enlargement, and also for formation of phellogen. Volumetric increase in these highly localized areas accounts for a small percentage of the increase in tuber volume resulting from enlargement of cells. 相似文献
144.
145.
A modified caustic peeling process for potatoes was developed and evaluated. The process, called the double-dip process, comprises two separate caustic applications with an intervening holding period. Results on Russet Burbank potatoes showed that tissue removal was enhanced for the double-dip process when compared to the standard single dip process and that the double-dip process can effect reduction in caustic usage without requiring additional heat input. 相似文献
146.
C. E. Logsdon H. W. Poulsen John J. Adams J. W. Scannell C. W. Frutchey Robert Hickman T. C. Blackburn J L. Robinson E. L. Newdick Paul J. Eastman L. O. Weaver H. C. Moore A. G. Tolaas L. A. Yager P. J. Hoff C. A. Lyon W. M. Cranstoun J. T. Stovall K. H. Fernow F. W. McLaughlin R. C. Hastings C. F. Campbell John Noonan H. L. Bruer J. W. Scott S. F. Grubbs L. W. King H. M. Darling C. M. Rincker 《American Journal of Potato Research》1957,34(5):142-148
147.
Abstract CASE HISTORY: Approximately 1 hour after the consumption of carnations from a nearby glasshouse 55 animals from a dairy goat herd exhibited signs of possible poisoning. CLINICAL FINDINGS: Upon clinical examination affected animals exhibited signs of salivation, tympany, tachypnoea, polydipsia, urination, diarrhoea, bradycardia, miosis, tremor and convulsions. As poisoning from an acetylcholinesterase-inhibiting insecticide was suspected, treatment with atropine sulphate was initiated at a dose of 0.3 mg/kg bodyweight. The treatment was repeated for some animals that relapsed, and was effective in all cases, with the exception of one goat kid that died. DIAGNOSIS: Necropsy of the goat kid showed pulmonary oedema and congestion of internal organs. Toxicological analysis of stomach contents and liver of the dead animal, as well as of the carnations, revealed high concentrations of carbamates. CLINICAL RELEVANCE: Carbamate poisoning after consumption of polluted feedstuffs or glasshouse products can be fatal for dairy goats. Atropine sulphate, at 0.3 mg/kg, can be useful in treating this condition. 相似文献
148.
Luther E. Talbert Jamie D. Sherman Megan L. Hofland Susan P. Lanning Nancy K. Blake Reagan Grabbe Peggy F. Lamb John M. Martin David K. Weaver 《Plant Breeding》2014,133(4):427-432
Several species of wheat stem sawflies (WSS) are pests of wheat, including Cephus cinctus Norton in North America. Larvae feed inside the stems and cut the stem near plant maturity. The primary means of control is resistance due to solid stems, largely controlled by a locus on chromosome 3B (Qss.msub‐3BL). Cultivars that differed for WSS resistance, but with similar stem solidness, were crossed to determine the genetic basis for the differences. The cultivar ‘Scholar’ is susceptible, while ‘Conan’ shows resistance. Scholar and Conan possessed different alleles at Qss.msub‐3BL. Both alleles conferred solidness, yet the Conan allele conferred higher WSS resistance. An allele from Conan on chromosome 4A also decreased infestation and stem cutting. The 3B and 4A alleles from Conan acted in an additive fashion to provide increased WSS resistance without increasing stem solidness. Stem solidness has long been used by breeders as a proxy for WSS resistance because of its simplicity. Our results suggest that other resistance mechanisms may complement solid stems. 相似文献
149.
To further our understanding of invasive species?? novel distributions, knowledge of invasive species?? relationships with environmental variables at multiple spatial scales is paramount. Here, we investigate which environmental variables and which spatial scales best explain the invasive mute swan??s (Cygnus olor) distribution in southern Ontario (Canada). Specifically we model mute swan distribution changes according to ecologically-relevant spatial scales: average territory size radius, 140?m; median dispersal distance of cygnets, 3,000?m; and average activity distance of males, 8,000?m. For individual spatial scales, global models using variables measured at each particular scale result in the highest Akaike weights, AUC, and Cohen??s Kappa values. Yet composite models (models combining variables measured at different scales) elicit the best models, as determined by higher Akaike weights and high AUC and Cohen??s Kappa values. Overall, percent water, waterbody perimeter density, temperature, precipitation, and road density are positively correlated with mute swan distribution, while percent forest and elevation are negatively correlated at all scales of analysis. Only percent water and annual precipitation are more influential in determining mute swan distribution at the 3,000 and 8,000?m zone scales than the territory scale. While most species distribution models are performed at a single scale, the results of our study suggest that composite models reflecting a species?? ecological needs provide models of better fit with similar, if not better, predictive accuracy. When analyzing species distributions, we also recommend that ecologists consider the scale of the underlying landscape processes and the effect that this may have on their modelling outcomes. 相似文献
150.
Semiochemicals to enhance herbivory by Diorhabda carinulata aggregations in saltcedar (Tamarix spp.) infestations
下载免费PDF全文
![点击此处可从《Pest management science》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Alexander M Gaffke Sharlene E Sing Tom L Dudley Daniel W Bean Justin A Russak Agenor Mafra‐Neto Paul A Grieco Robert KD Peterson David K Weaver 《Pest management science》2018,74(6):1494-1503