全文获取类型
收费全文 | 1359篇 |
免费 | 51篇 |
国内免费 | 3篇 |
专业分类
林业 | 99篇 |
农学 | 70篇 |
基础科学 | 17篇 |
257篇 | |
综合类 | 89篇 |
农作物 | 140篇 |
水产渔业 | 150篇 |
畜牧兽医 | 432篇 |
园艺 | 25篇 |
植物保护 | 134篇 |
出版年
2023年 | 15篇 |
2022年 | 30篇 |
2021年 | 63篇 |
2020年 | 74篇 |
2019年 | 61篇 |
2018年 | 51篇 |
2017年 | 58篇 |
2016年 | 49篇 |
2015年 | 55篇 |
2014年 | 56篇 |
2013年 | 117篇 |
2012年 | 86篇 |
2011年 | 104篇 |
2010年 | 49篇 |
2009年 | 31篇 |
2008年 | 58篇 |
2007年 | 52篇 |
2006年 | 33篇 |
2005年 | 33篇 |
2004年 | 34篇 |
2003年 | 34篇 |
2002年 | 25篇 |
2001年 | 14篇 |
2000年 | 14篇 |
1999年 | 13篇 |
1998年 | 4篇 |
1997年 | 7篇 |
1996年 | 9篇 |
1995年 | 8篇 |
1994年 | 6篇 |
1993年 | 9篇 |
1991年 | 11篇 |
1990年 | 10篇 |
1989年 | 14篇 |
1988年 | 8篇 |
1987年 | 10篇 |
1986年 | 9篇 |
1985年 | 10篇 |
1984年 | 12篇 |
1983年 | 9篇 |
1981年 | 7篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1976年 | 4篇 |
1975年 | 7篇 |
1973年 | 4篇 |
1972年 | 4篇 |
1971年 | 5篇 |
1970年 | 5篇 |
1969年 | 4篇 |
排序方式: 共有1413条查询结果,搜索用时 295 毫秒
991.
992.
993.
994.
995.
The opsonization and lysis of different protozoa by antibodies and/or complement was followed using luminol-dependent chemiluminescence and bioluminescence. The addition of immune serum to variable antigen type populations of Trypanosoma evansi led to the specific opsonization of trypanosomes resulting in an intense metabolic activation and chemiluminescence response of phagocytic cells. In comparison to those of uninfected control mice, the phagocytosis of coccidia merozoites by spleen cells from mice infected with Eimeria falciformis was enhanced during the acute stage of a primary infection. Opsonizing activity was demonstrated in phosphate-buffered saline extracts of gut contents of mice infected for 10 days. The incubation of E. falciformis merozoites together with guinea-pig complement resulted in slow lysis of the cells. The addition of mouse serum collected greater than 6 days after an infection led to an accelerated lysis of the merozoites, indicating the appearance of complement-fixing antibodies in the serum. Heat-inactivated immune serum alone had no lysing activity on merozoites. In the presence of complement, bovine lymphoblastoid cells infected with Theileria annulata were lysed by anti-lymphoblastoid cell serum raised in mice but not by serum from cattle which had developed immunity to Theileria annulata. 相似文献
996.
W. F. Khalil T. Saitoh M. Shimoda & E. Kokue 《Journal of veterinary pharmacology and therapeutics》2001,24(5):343-348
Total hepatic microsomal cytochrome P450 (CYP) content as well as in vitro CYP mediated activities for five substrates [bufuralol 1-hydroxylation, ethoxyresorufin O-deethylation, S-mephenytoin 4-hydroxylation, testosterone 6beta-hydroxylation, and tolbutamide hydroxylation] were measured in specific pathogen free male Japanese leghorn chickens and male beagle dogs. The Vmax, Km and intrinsic clearance (Vmax/Km) for these substrates were calculated and compared between animal species in order to evaluate the drug catalytic activity in chicken liver. The total CYP content in chicken (0.296 +/- 0.04 nmol/mg microsomal protein) was close to levels reported for other species including humans, cats, pigs and some nonmammalian vertebrates (e.g. snakes, frogs and trout fish), but was lower than levels measured in dogs (1.11 +/- 0.22) or recorded in guinea-pigs, hamsters, monkeys, mice, rabbits, rats, horse and ruminants. Bufuralol 1-hydroxylation, ethoxyresorufin O-deethylation, S-mephenytoin 4-hydroxylation, and testosterone 6beta-hydroxylation were lower in chickens than in dogs based on intrinsic clearance. On the other hand, tolbutamide hydroxylation was markedly higher in chickens than in dogs. 相似文献
997.
998.
The sequential development of the clinical signs and lesions in the organs of desert sheep and Nubian goats dosed with Jatropha curcas seeds at 0.05, 0.5 and 1 g/kg/day was studied. Diarrhoea, reduced water consumption, dehydration, sunken eyes, inappetence and loss in condition were the important signs of J curcas poisoning in sheep and goats. The main pathological changes were haemorrhage in the rumen, reticulum, lungs, kidneys and heart, catarrhal and/or haemorrhagic enteritis, hepatic fatty change, pulmonary congestion and oedema and straw-coloured fluid in serous cavities. An increase in the concentrations of AST, ammonia, potassium and sodium and a decrease in total protein and calcium were detected in the serum. Haematological changes were haemoconcentration and leucocytosis. 相似文献
999.
1000.
Reda M. El-Shishtawy G. M. Shokry Nahed S. E. Ahmed M. M. Kamel 《Fibers and Polymers》2009,10(5):617-624
Hydrophobic fibers are highly crysta lline and non-polar polymers hence pose a big problem for dyers. Modified acrylic fiber
containing different amounts of amidoxime groups as a function of the nitrogen content was obtained and dyed with curcumin
and madder natural dyes. The dyeing parameters, such as dye concentration, dye bath pH, salt concentration, temperature, and
time and the effect of alum and ferrous sulfate used as mordants were investigated. Compared with the dyeings obtained from
modified acrylics, those of blank samples appeared less in color strength values. The color strength was proportional to the
nitrogen content of the sample and the maximum value was obtained at pH 2 and pH 5 using madder and curcumin, respectively.
The fixation of the dye molecules to the modified acrylic fibers was investigated to show mainly ionic and physical bonds.
The washing, perspiration, and rubbing fastness properties for the dyed samples were enhanced by application of alum. The
light fastness ratings were also improved using ferrous sulfate especially for the case of the samples dyed with madder. 相似文献