全文获取类型
收费全文 | 106篇 |
免费 | 7篇 |
专业分类
林业 | 11篇 |
基础科学 | 1篇 |
18篇 | |
综合类 | 36篇 |
农作物 | 15篇 |
水产渔业 | 2篇 |
畜牧兽医 | 26篇 |
园艺 | 2篇 |
植物保护 | 2篇 |
出版年
2015年 | 4篇 |
2014年 | 2篇 |
2013年 | 7篇 |
2011年 | 6篇 |
2010年 | 2篇 |
2008年 | 2篇 |
2007年 | 3篇 |
2006年 | 3篇 |
2005年 | 5篇 |
2004年 | 1篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1975年 | 2篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1969年 | 2篇 |
1968年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1957年 | 2篇 |
1955年 | 1篇 |
1948年 | 1篇 |
1947年 | 3篇 |
1945年 | 1篇 |
1944年 | 2篇 |
1943年 | 3篇 |
1941年 | 1篇 |
1940年 | 1篇 |
1938年 | 1篇 |
1919年 | 1篇 |
1903年 | 1篇 |
1902年 | 1篇 |
1893年 | 2篇 |
排序方式: 共有113条查询结果,搜索用时 15 毫秒
61.
Ur?a?VilharEmail author Michael?Starr Mihej?Urban?i? Igor?Smolej Primo??Simon?i? 《European Journal of Forest Research》2005,124(3):165-175
The monthly water balance in gaps in a managed Dinaric silver fir–beech forest and a virgin forest remnant located in SE Slovenia
was modelled using a capacity water balance model for two growing seasons. Two gaps of different size (ca. 0.07 and 0.15 ha)
were selected in each forest and plots for soil moisture monitoring were established in each gap (2–4) and in the surrounding
forest (2–3). We report on the modelled actual evapotranspiration (AET) and potential evapotranspiration (PET) and drainage
fluxes (DF) from the rooting zone at the plots. Precipitation over the 2001 growing season (May–October) was considerably
drier than average and that for 2002 growing season was wetter than average. Modelled AET for the 2001 growing season varied
between 88% and 96% of PET for the managed forest plots and between 90% and 100% for the virgin forest plots. The values for
the gap plots varied between 87% and 100% at the managed forest site and between 92% and 96% for the gaps in the virgin forest
site. Monthly AET values declined to 57–59% of PET at plots in the centre of the gaps in the managed forest site and to 63–74%
in the gaps in the virgin forest site (July), indicating that the highest drought stress occurs in gap centres. For 2002 growing
season, AET for all plots was 100% of PET. Modelled DF values in 2001 were 13–35% of rainfall for plots in the gap centres
and 12–16% for plots in the forest at the managed forest site. On an average, gap DF values were 20% (154 mm) higher than
the forest plot values. DF values in 2002 were similar for all plots at the managed forest site, 31–33% of rainfall. At the
virgin forest site, 2001 growing season, DF values varied between 12% and 30% of rainfall at the forest plots and between
12% and 32% at the gap plots. In 2002, DF values for all plots in the virgin forest site varied between 24% and 38% of growing
season rainfall. The varying development of vegetation and forest in the gaps of the virgin forest remnant resulted in more
variable evapotranspiration and DF during the drought year 2001, with values not as clearly related to distance from the gap
centre as in the managed forest site. 相似文献
62.
63.
64.
Haemolysin is one type of virulence factor that assists in the pathogenesis of Escherichia coli. Currently, hemolytic activity in E. coli has been attributed to haemolysin genes found in either uropathogenic or enterohemorrhagic E. coli. Both haemolysins are classified as RTX toxins because they both have repeats in toxin domains and share similar operon organization, sequence homology, and mechanisms of action. Haemolytic avian E. coli isolates, however, lack either E. coli haemolysin gene. To investigate the avian E. coli haemolysin, a genomic library was made from an avian pathogenic E. coli. A haemolytic clone that was isolated was shown to contain homology with sheA, an E. coli K- 12 gene which causes haemolysis when present in high copy number. The cloned haemolysin gene, hlyE, lacked the conserved amino acid sequence and accessory genes common to all RTX toxins. DNA hybridizations and polymerase chain reaction amplifications showed that the nucleotide sequences homologous to hlyE were not present in a collection of three O157: H7 E. coli, five haemolytic canine uropathogenic E. coli, one haemolytic O26 E. coli, and three haemolytic avian pathogenic E. coli. Thus we have identified a new E. coli haemolysin distinct from the RTX haemolysins and have shown that some avian pathogenic E. coli possess a haemolysin with no apparent homology to hlyE or RTX haemolysins. 相似文献
65.
66.
67.
Paul Berdoulay DVM DACVIM Michael Schaer DVM DACVIM DACVECC Jessica Starr 《Journal of Veterinary Emergency and Critical Care》2005,15(3):206-212
Objective: This case report describes antivenin‐associated acute and delayed hypersensitivity reactions in a dog envenomated by an Eastern diamondback rattlesnake (Crotalus adamanteus), specifically reviewing the syndrome of antivenin‐associated serum sickness. Clinician awareness of this syndrome is important in order to allow for its recognition and appropriate treatment. Case summary: A Boxer dog was envenomated by an Eastern diamondback rattlesnake. Shock, echinocytosis, and coagulopathy were manifested, and the dog was given antivenin crotalidae polyvalent therapy and supportive care. The early onset of an anaphylactoid reaction was attributed to antivenin therapy and was managed with diphenhydramine and subcutaneous epinephrine therapy. Fever, chemosis, and limb edema occurred during the 3rd through 6th hospital days following antivenin therapy and were consistent with serum sickness syndrome as described in humans. Further immunoassay support reflecting complement activation and response to treatment were characteristic. New information provided: To our knowledge, this describes the first reported case of antivenin‐associated serum sickness in a dog. 相似文献
68.
69.
L H Kasman J P Hughes G H Stabenfeldt M D Starr B L Lasley 《American journal of veterinary research》1988,49(2):184-187
Serum and urinary estrone sulfate concentrations were determined in 7 pregnant mares before and after prostaglandin-induced abortion (n = 4) or surgical removal of the fetus (n = 3) to determine the source of estrogen during early pregnancy (gestation days [GD] 44 to 89). Estrone sulfate concentrations also were determined in serum samples (stored frozen for 2 years) from 3 mares that had been ovariectomized between GD 51 and 58. Estrone sulfate concentrations decreased in serum and urine after expulsion or removal of the fetus (urinary patterns were more definitive than were patterns for serum), whereas a transient decrease in serum estrone sulfate concentration was observed after ovariectomy. Seemingly, products of conception are the major source of estrone sulfate during early pregnancy, although there appears to be some ovarian contribution. Serum or urinary estrone sulfate measurements provide a simple and accurate test for fetal viability after GD 44 in the mare. 相似文献
70.