全文获取类型
收费全文 | 110篇 |
免费 | 3篇 |
专业分类
林业 | 55篇 |
农学 | 2篇 |
基础科学 | 1篇 |
6篇 | |
综合类 | 11篇 |
水产渔业 | 3篇 |
畜牧兽医 | 31篇 |
植物保护 | 4篇 |
出版年
2021年 | 1篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2014年 | 3篇 |
2013年 | 1篇 |
2012年 | 3篇 |
2011年 | 4篇 |
2010年 | 3篇 |
2009年 | 4篇 |
2008年 | 3篇 |
2006年 | 5篇 |
2005年 | 2篇 |
2004年 | 6篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2000年 | 1篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1975年 | 1篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1967年 | 1篇 |
1957年 | 1篇 |
1955年 | 2篇 |
1952年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有113条查询结果,搜索用时 0 毫秒
81.
82.
83.
The acquired immunity consists of two pathways namely the humoral immunity that defends the host against extracellular pathogens such as bacteria and the cell-mediated immunity that defends the host against intracellular pathogens such as Mycobacterium tuberculosis and viruses and also against cancers. The aim of this study is to determine the effects of river water collected from pristine and contaminated sites along the Eerste River, South Africa on inflammation, humoral and acquired immune pathways. Hydrophobic extracts were prepared from water collected at contaminated and pristine sites. Inflammatory activity was determined by measuring interleukin (IL)-6 levels synthesized by whole blood after incubation with the extracts. For determining the effects on acquired immunity, phytohemagglutinin stimulated whole blood from healthy volunteers was incubated with extracts. The effect on humoral immunity was determined using IL-10 as biomarker, while interferon-gamma was used as biomarker for cell-mediated immunity. The results obtained show that water from the sites downstream from human activity induced IL-6, a biomarker of inflammation. Extracts collected from a site downstream from an informal housing settlement suppressed biomarkers of both humoral and cell-mediated immunity. Water from sites impacted by human activity can potentially suppress the acquired immune system and this can pose a health risk to people using this water source. Studies must be done to investigate the long-term effects of the contaminated water on animals in vivo. 相似文献
84.
James F. Hancock James W. Olmstead Rachel A. Itle Peter W. Callow Stuart Neils-Kraft Edmund J. Wheeler Jozer Mangandi Suneth S. Sooriyapathirana Lisa J. Rowland Ted A. Mackey Nahla V. Bassil Chad E. Finn 《Euphytica》2018,214(6):95
A family of the cross of the northern highbush blueberry ‘Draper’?×?the southern highbush ‘Jewel’ (D?×?J) was propagated and phenotyped for plant size, yield, rate of flower, bud, and fruit development, leafing ability, winter hardiness, and fruit quality for 2 years in the field in Florida (FL), Georgia (GA), Michigan (MI), and Oregon (OR). In addition, a controlled greenhouse study was conducted on these progenies to estimate their chilling requirements. Significant levels of genotypic variability were observed for all the traits and the majority showed significant location and genotype?×?environmental interactions. Most of these traits were normally distributed across genotypes. There were many more flower buds per cane in GA than FL and OR, and many more vegetative buds broke in OR than in the southeastern states. Most of the various yield and growth traits were significantly correlated, except for flower buds per cane with plant height and width, and strength of leafing with plant width and flower buds/cane. Plants in OR developed much more slowly than those in FL and GA. There was a significant G?×?E effect on days to early green tip, floral bud break, and full bloom. Significant correlations were observed between all the developmental rates except between floral bud break and the days to full flowering and first blue fruit. Most individuals were severely damaged by winter cold in MI, although a few showed good tolerance. Significant location effects were observed for pH, titratable acidity (TA), soluble solids (SS), and SS/TA. Fruit in FL were a little softer and had higher SS/TA ratios than those in GA. There were significant interactions between genotype and environment for all the fruit quality traits except for fruit scar, firmness, anthocyanin content (ACY), and % juice. Fruit scar had a significant positive relationship with firmness and a significant negative relationship with flavor. Fruit color was significantly associated positively with soluble solids and ACY. Firmer fruit had significantly lower levels of ACYs. Fruit pH showed significant positive correlations with TA, TA/SS, and % juice, and significant negative relationship with SS and ACY. TA was significantly associated negatively with TA/SS and positively with ACY and % juice. TA/SS and ACY were positively correlated significantly with % juice. Two or three individuals were identified at each location that had high yields, were very early or late ripening and had excellent overall fruit quality. There were significant levels of genotypic, environmental (chilling hours) and G?×?E interaction among vegetative and floral buds for numbers of buds per shoot, percentage that developed and their developmental rate. The chilling requirement of highbush blueberry appears to be regulated polygenically as the D?×?J family segregated normally. On average, genotypes did more poorly at 250 and 350 chilling hours than the other chilling treatments. 相似文献
85.
86.
Edmund Leib 《Journal of pest science》1973,46(5):74-75
Summary
The new decree for protection of bees
The new decree is represented as an example for a measure directed to the protection of the world ariund us. Prohibitions, orders and obligations in connection with the protection of bees on occasion of chemical control of pests are described.
7737 Bad Dürrheim, Königsberger Straße 35. 相似文献
7737 Bad Dürrheim, Königsberger Straße 35. 相似文献
87.
Edmund J Leigh Edward Mackillop Ian D Robertson Lola C Hudson 《Veterinary radiology & ultrasound》2008,49(2):113-121
The purpose of this study was to produce an magnetic resonsnce (MR) image atlas of clinically relevant brain anatomy and to relate this neuroanatomy to clinical signs. The brain of a large mixed breed dog was imaged in transverse, sagittal, and dorsal planes using a 1.5 T MR unit and the following pulse sequences: Turbo (fast) spin echo (TSE) T2, T1, and T2- weighted spatial and chemical shift-encoded excitation sequence. Relevant neuroanatomic structures were identified using anatomic texts, sectioned cadaver heads, and previously published atlases. Major subdivisions of the brain were mapped and the neurologic signs of lesions in these divisions were described. TSE T2-weighted images were found to be the most useful for identifying clinically relevant neuroanatomy. Relating clinical signs to morphology as seen on MR will assist veterinarians to better understand clinically relevant neuroanatomy in MR images. 相似文献
88.
89.
YANG Xiu-shi ;WANG Li-jun ;DONG Chuan ;Edmund Man King Lui ;REN Gui-xing 《中国农业科学(英文版)》2014,(12):2807-2815
Ultrasonic-assisted extraction (UAE) of American ginseng polysaccharides (AGP) was investigated using response surface methodology. Three-factor-three-level Box-Behnken design was employed to optimize the ultrasonic power, extraction time and ratio of water to raw material to obtain a high AGP yield. The analysis of variance and response surface plots indicated that ultrasonic power was the most important factor affecting the extraction yield. The optimal conditions were ultrasonic power 400 W, extraction time 71 min, and ratio of water to raw material 33 mL g-1. Under these conditions, the yield of AGP was 8.09%, which was agreed closely to the predicted value. Gas chromatography (GC) analysis showed that AGP was composed of arabinose, rhamnose, galactose, glucose, and galacturonic acid. Fourier transform infrared spectra revealed the general characteristic absorption peaks of AGP. In addition, AGP exhibited good immunostimulating activities by up-regulating the production of nitric oxide and cytokines. Compared with hot water extraction, UAE required shorter extraction time and gave a higher extraction yield, without changing the structure and immunostimulating activity of AGP. The results indicated that UAE could be an effective and advisable technique for the large scale production of plant polysaccharides. 相似文献
90.
Reg.-Rat Dr. Edmund Leib 《Journal of pest science》1952,25(5):65-68
Ohne ZusammenfassungAnm. d. Schriftl.: Im Interesse der Geschlossenheit der vom Verfasser im Saarland gemachten Beobachtungen und im Hinblick auf den in der Einleitung des Aufsatzes zum Ausdruck gebrachten zielstrebigen Grundgedanken, glauben wir es ausnahmsweise verantworten zu dürfen, den unserer Zeitschrift bewußt gesteckten Rahmen, nur von tierischen Schädlingen zu berichten, in diesem zusammenfassenden Beitrag zu überschreiten. 相似文献