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151.
152.
Detection of antibodies in serum and egg yolk following infection of chickens with an H6N2 avian influenza virus. 总被引:3,自引:0,他引:3
Darrell W Trampel En-Min Zhou Kyoung-Jin Yoon Kenneth J Koehler 《Journal of veterinary diagnostic investigation》2006,18(5):437-442
Active serologic surveillance programs to detect avian influenza viruses (AIVs) in table egg-laying chickens have been initiated by several states as a response to the economic threat posed by these viruses. Most outbreaks of avian influenza in domestic poultry are caused by mildly pathogenic AIVs. In the study reported here, infection by an H6N2 AIV was used as a model of mildly pathogenic AIV infections in egg-type chickens. The total number of eggs laid by 5 control hens was 619 or 0.904 eggs/day/hen, whereas the total number laid by 10 infected hens was 1,018 or 0.743 eggs/day/hen. The difference in egg production between the 2 groups was not statistically significant (P = 0.38). Anti-influenza antibodies were monitored by use of an agar gel immunodiffusion test and an ELISA for a period of 20 weeks after inoculation. Antibodies in serum developed sooner, peaked at higher levels, and remained at higher levels than did antibodies found in egg yolk, as indicated by ELISA results. For infected chickens, the correlation between serum and egg yolk ratios was 0.66. Serum samples would appear to be preferable to egg yolk samples for surveillance programs intended to identify chicken flocks that may have been infected by an AIV weeks or months before samples are collected. 相似文献
153.
154.
Zirui Zhou Jie Zhang Xianlian Zhang Shilan Mo Xian Tan Lixia Wang Jianzhong Li Yali Li Xueqin Ding Xianyong Liu Xingqun Ma Huansheng Yang Yulong Yin 《Journal of animal physiology and animal nutrition》2019,103(5):1530-1537
Weaning process widely affects the small intestinal structure and function in piglets, while the responses of large intestine to weaning stress are still obscure. The purpose of this study was to determine the developmental changes (i.e., short chain fatty acids (SCFAs) concentrations, growth parameters, crypt‐related indices and antioxidant capacity) in colon of piglet during weaning. Forty piglets were weaned at day 21 and euthanized to collect colonic tissues and digesta samples on day 0, 1, 3, 7 and 14 post‐weaning (n = 8). Piglet growth performance was improved (p < .001) on day 7 and 14 post‐weaning. The concentrations of acetate, propionate, butyrate, valerate, isobutyrate, isovalerate and total SCFAs were higher (p < .001) during the late post‐weaning period. The mRNA abundances of SCFAs transporters were greater (p < .001) on day 7 and 14. The absolute and relative weights, absolute length and perimeter of colon were greater (p < .001) on day 7 and 14. Similarly, post‐weaning increases (p < .001) in colonic crypt depth and Ki67 positive cells numbers per crypt were observed during the same period. Colonic crypt fission indices decreased (p < .01), while total crypt numbers increased (p < .001) on day 14 after weaning. Moreover, total SCFAs concentration was significantly associated with colonic growth parameters and Ki67 cells/crypt (p < .001). In addition, catalase content was decreased on day 3, 7, and 14, whereas, the concentrations of total superoxide dismutase (T‐SOD) and manganese‐containing superoxide dismutase (MnSOD) were higher (p < .05) on day 1 and 3 post‐weaning. These results showed that weaning process has a significant effect on colonic growth and development, which might be associated with the change of SCFAs concentrations in colon. 相似文献
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156.
本文采用过甲酸氧化水解法处理饲料及饲料原料样品、通过日立L-8900氨基酸自动分析仪检测样品中的含硫氨基酸含量,结果显示:每份试样平行测试结果相对偏差小于4%.蛋氨酸和胱氨酸峰面积回收率在93.02%~102.06%.该方法测定含硫氨基酸的重复性和准确性良好.氧化水解法比常规盐酸水解法处理样品检测含硫氨基酸.检测结果更为准确。 相似文献
157.
利用AFLP分子标记技术,对4个高丹草新品系11A-黑壳苏丹草、11A-白壳苏丹草、11A-棕壳苏丹草、11A-黑壳苏丹章晚熟型与对照品种蒙农青饲1号、蒙农青饲2号、蒙农3号及乐食高丹草的遗传差异性进行比较分析.结果表明:用筛选出的24对适宜引物共扩增出3986个AFLP位点,其中多态性位点3546个,多态性位点比率高达88.96%;各供试材料的遗传距离(GD)变动在0.6905~0.8089之间,以GD值0.74为基准,8个材料聚为3类,第一类为蒙农青饲1号、蒙农青饲2号、蒙农3号、11A-黑壳苏丹草、11A-白壳苏丹草、11A-黑壳苏丹草晚熟型;第二类为乐食;第三类为11A-棕壳苏丹草. 相似文献
158.
营地下生活的啮齿动物被誉为陆地生态系统的工程师,但其长期栖居于地下的生活习性难以被人们直接观察,给动物行为学和生态生物学等研究带来了挑战。随着科学技术的发展,无线电技术的小型化和轻量化为地下啮齿动物研究提供了可行性。国外学者已成功将无线电追踪技术应用于对地下啮齿动物洞道系统、活动节律、巢域面积变化以及社群制度等的研究。但国内将其应用于地下啮齿动物研究的较少。本文根据目前国内外研究现状,对无线追踪技术的研究内容和研究方法进行综述,以期为我国地下啮齿类研究提供参考。 相似文献
159.
饲料不安全因素对人类健康及生态环境的影响 总被引:2,自引:0,他引:2
饲料的安全性不仅影响动物健康和生产性能.而且通过动物及动物产品影响人类健康及食物链上其它成员的安全,甚至影响环境的生态平衡(冯定远,2005)。饲料中抗营养因子的存在:药物添加剂、高铜添加剂和有机砷制剂等生长促进剂的长期使用和滥用:盐酸克伦特罗和其它违禁激素类药物的非法使用:饲料微生物、农药及工业三废污染等,都是饲料的不安全因素。这些不安全因素不仅影响畜产品安全及人类健康,同时,畜禽排泄物及废弃饲料中重金属、药物和病原微生物等有毒有害物质成为严重污染生态环境的污染源,土壤、空气、水源等人类赖以生存的环境被污染。全面分析饲料不安全因素对人类健康及生态环境的影响.可以提高人们对饲料及畜产品的安全意识,确保畜产品安全问题的源头——饲料的安全. 相似文献
160.