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141.
142.
用不同的时间和温度培养鸡致病性E.cloi,41℃,48h和37℃,72h均可见众多的菌毛,而在41℃,48h的条件下,活菌数及菌毛产量均高于37℃,72h的。用提取的菌毛、超声波灭活的E.coli制成油乳苗免疫鸡,用同型O50菌株经后胸气囊攻毒后,免疫鸡无死亡,而氢氧化铝胶菌苗免疫组的死亡率为20%,未免疫攻毒组死亡率为33.3%。各免疫组幸存鸡平均病变级数均显著低于未免疫攻毒组(P<0.01)。E.coli的菌毛剂量为120μg/只和80μg/只的油乳苗免疫组,在免疫后用同型O50菌株攻击时,保护指数最高;当剂量为60μg/只时,保护指数较高;而用30μg/只的剂量免疫时,免疫无效。雏鸡经含菌毛、不含菌毛的E.coli超声波灭活油乳苗和福尔马林灭活油乳苗免疫后用同型O50菌株攻毒,含菌毛菌苗的保护指数均高于相应的不含菌毛菌苗的;超声波灭活菌体的油乳苗免疫组幸存鸡平均病变级数低于福尔马林灭活菌体的油乳苗免疫组的;各免疫组与未免疫攻毒组幸存鸡平均病变级数差异极显著(P<0.01)。 相似文献
143.
分别用几种化学物质从黄瓜幼苗子叶期开始进行根部诱导,结果表明,在自然病原激发病害试验和在人工接种病原激发病害试验中,经苯酚、脲素、无水对氨基苯磺酸和氯化钾诱导的黄瓜植株病株率和病叶率下降显著。对可产生诱导免疫效果的化学物质分析发现,氨类和苯类物质及钾的氯化物与黄瓜叶片对霜霉病的抗性有极为密切的关系。 相似文献
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B. C. Njau 《Veterinary research communications》1990,14(2):123-128
The secondary antibody response to sheep red blood cells and bovine serum albumin (BSA) was measured in rabbits infested with adult Rhipicephalus evertsi evertsi. The response was reduced (particularly for BSA) but still displayed anamnestic characteristics. Resistance against ixodid ticks associated with antibodies detected by gel diffusion and enzyme linked immunosorbent assay techniques early in the primary challenge was acquired by the immunized hosts only. This suggests that a non-specifically activated immune system enables hosts to develop rapid resistance against tick parasitism. 相似文献
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148.
K.P. Flaming R.C. Thaler F. Blecha J.L. Nelssen 《Comparative immunology, microbiology and infectious diseases》1988,11(3-4):181-187
Mitogen-stimulated lymphocyte proliferation, delayed-type hypersensitivity (DTH) reactions, interleukin-2 (IL-2) production, and growth performance were evaluated in 3-week-old pigs treated with imuthiol. Lymphocyte proliferative responses to Con A and PWM were reduced (P < 0.05) in pigs treated with imuthiol at 25 mg/kg; PHA proliferative responses were not influenced by imuthiol treatment. Imuthiol at 2.5 mg/kg and 25 mg/kg lowered IL-2 production when compared to saline-treated controls. Delayed-type hypersensitivity responses to PHA were higher in 25 mg/kg imuthiol-treated pigs; however, 2.5 mg/kg imuthiol-treated pigs had lower DHT reactions. Imuthiol at 2.5 mg/kg and 25 mg/kg reduced (P < 0.05) average daily feed intake. These data suggest that in vivo imuthiol treatment in pigs lowers lymphocyte proliferative responses, IL-2 production, and growth performance. 相似文献
149.
Stanley G Rabinowitz Jayashree Huprikar Caroline Whitacre 《Comparative immunology, microbiology and infectious diseases》1979,1(4):295-303
C57B16 mice were immunized with either live, attenuated TC-83 strain VEE virus vaccine or formalin-inactivated VEE vaccine combined with Bordetella pertussis. The kinetics of specific donor and adoptively-immunized recipient anti-VEE neutralizing antibody responses were studied. Donor mice immunized with either live or inactivated VEE virus vaccine combined with potent adjuvants develop specific anti-VEE IgM and IgG responses as early as 7 days post-immunization. Anti-VEE IgM antibody responses comprise the majority of anti-VEE neutralizing antibody at this early time period. By 14 to 21 days post-immunization, anti-VEE IgG responses predominated. When adoptively-immunized recipients were studied, the anti-VEE IgM to IgG predominance seen in donors early after administration was reversed, and for each time-period studied, recipients' serum anti-VEE antibody class responses consisted principally of IgG rather than IgM antibody. Since T-cells cooperation with B-cells is critical in the IgM-IgG antibody shift, these studies support the critical role T-cells exert in adoptive transfer in a murine model of experimental VEE infection. Furthermore, immunization with either live or inactivated VEE vaccine coupled to a potent adjuvant induce comparable donor and adoptively-immunized recipient anti-VEE antibody class responses. 相似文献
150.
G.S Elissalde Harland W Renshaw James A Walberg 《Comparative immunology, microbiology and infectious diseases》1980,3(4):433-445
A review of the recent and/or significant literature concerning Corynebacterium equi, including its morphologic, biochemical, immunological, and pathological characteristics in the foal, humans and other animals is presented. The similarity in the tissue responses of mammalian hosts to C. equi and Mycobacterium spp. is discussed.
The antigenic structure and virulence factors associated with C. equi. other corynebacteria and mycobacteria are compared.
The immunological aspects of resistance to C. equi are considered. The evidence suggests that the major immune response elicited in the foal by C. equi is cell-mediated. However, the immunopathogenic mechanism needs clarification. Areas of future research are suggested. 相似文献