全文获取类型
收费全文 | 1124篇 |
免费 | 85篇 |
国内免费 | 271篇 |
专业分类
林业 | 7篇 |
农学 | 15篇 |
基础科学 | 3篇 |
21篇 | |
综合类 | 255篇 |
农作物 | 36篇 |
水产渔业 | 31篇 |
畜牧兽医 | 1105篇 |
园艺 | 1篇 |
植物保护 | 6篇 |
出版年
2024年 | 17篇 |
2023年 | 50篇 |
2022年 | 58篇 |
2021年 | 82篇 |
2020年 | 73篇 |
2019年 | 67篇 |
2018年 | 41篇 |
2017年 | 46篇 |
2016年 | 49篇 |
2015年 | 56篇 |
2014年 | 92篇 |
2013年 | 92篇 |
2012年 | 100篇 |
2011年 | 91篇 |
2010年 | 67篇 |
2009年 | 70篇 |
2008年 | 54篇 |
2007年 | 45篇 |
2006年 | 61篇 |
2005年 | 51篇 |
2004年 | 41篇 |
2003年 | 38篇 |
2002年 | 20篇 |
2001年 | 25篇 |
2000年 | 15篇 |
1999年 | 11篇 |
1998年 | 9篇 |
1997年 | 9篇 |
1996年 | 9篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1991年 | 2篇 |
1990年 | 5篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1979年 | 1篇 |
排序方式: 共有1480条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
在蓖麻蚕生产中,软化病(细菌性胃肠病和细菌性败血病的总称)发生得比较多,尤其在五龄期发病严重,对生产威胁较大,本试验用消特灵、绿迪奥、蚕用绿霉素、大蒜白酒液(自制)蚕药在蓖麻蚕五龄期分别添食,结果表明以上药液添食后,五龄蚕期病死蚕率比对照区明显降低。 相似文献
995.
本文为应用~(60)Co—γ射线辐照边条红参(Radix Ginseng)、当归(Radix AnselicaeSinensis)、槟榔(Semen Arecae)等21种中药材杀虫、灭菌效果及其主要有效成分变化的研究。结果表明,辐照杀虫剂量范围为1.5~2.3kGy;灭菌剂量范围为3.8~7.6kGy;以3.7~20.6kGy剂量辐照边条红参、当归头、槟榔、其主要有效成分人参总皂甙、人参单体皂甙Rg_1,当归挥发油以及榔槟生物碱的颜色和百分含量均无明显变化,杀虫、灭菌效果显著,防止二次感染、辐照后贮藏一年仍可达到色鲜、味正、不生虫、不发霉的良好效果。 相似文献
996.
A questionnaire survey on the factors affecting the motivation and work attitudes of Finnish veterinary meat inspectors was conducted. Traditional meat inspection on the slaughtering line and in the emergency department took up most of the weekly work time (15.8% and 15.8%, respectively). Emergency slaughtering (29%) and general hygiene control (29%) were considered the most important tasks of veterinary meat inspectors. Assurance of meat safety (68%) was cited as the most important single reason for meat inspection. Veterinary meat inspectors were of the opinion that they do not play an important role in the training of slaughterhouse personnel, although they considered training to be a very important means for promoting hygienic work methods among workers. Three orientations of the respondents toward meat inspection and slaughterhouse operations were revealed from the survey: hygiene, education, and emergency slaughter work orientation. Meat inspection veterinarians may feel isolated from the other personnel responsible for maintaining quality and hygiene. The orientation and possible isolated position of veterinary meat inspectors should be given more attention in both the basic undergraduate and postgraduate training of veterinary meat inspectors. 相似文献
997.
Ota Barta Priscilla P Oyekan 《Comparative immunology, microbiology and infectious diseases》1981,4(2):209-221
Lymphocyte transformation test is a powerful tool in laboratory testing of immunologic competence of animals. The impaired function of the lymphocytes or presence of mitogenesis suppressing factors in the patient serum were detected by comparing lymphocyte transformation (expressed as thymidine incorporation) obtained in media containing either autologous, homologous, or fetal calf serum additions. Most valuable results were obtained by using at least two, preferably three, different phytomitogens: concanavlin A (Con A), pokeweed mitogen (PWM), and pl ytohemagglutinin (PHA) at optimal concentrations (Con A, 15 μg/ml, PWM and PHA, 5 μg/ml) and decreased concentrations (Con A, 5 μg/ml, PWM and PHA, 1 μg/ml). Mitogenesis induced by lipopolysaccharide was considerably smaller and not used routinely. With 2 × 105 lymphocytes/well, the background count of unstimulated lymphocytes in autologous serum in healthy dogs was usually between 100 and 400 counts/min (CPM), in clinically healthy cattle and horses from 200 to over 2000 CPM. Higher CPM were rarely detected without clinical disease. Increased background counts were often associated with viral infections, leukemias and lymphoreticular hyperplasias, decreased background counts were associated with various diseases. The stimulation indexes (SI) of healthy animals in autologous serum with Con A, (5 μg/ml) or PWM or PHA (1 μg/ml) were in the range from 100 to 1000 in the dogs, in the tens for Con A and in hundreds for PWM and PHA in horses and cattle. Increased SI were present during the incubation period of various diseases. Decreased SI were associated with numerous infectious and lymphoreticular diseases and were caused by any of the following: (1) the presence of serum immunosuppressive factor(s) in the patient serum, (2) the decreased response of lymphocytes to mitogens, or (3) increased mitogenicity of lymphocytes due to unidentified serum factors in absence of phytomitogens. 相似文献
998.
M.B. Whiteley DVM D.B. Kestenman DVM D.A. Feeney DVM MS 《Veterinary radiology & ultrasound》1991,32(1):35-47
A review of the veterinary radiotherapy literature from 1939 through June of 1989 is presented. Subject material includes: radiation effects/injury, radiation oncology, hyperthermia, phototherapy, and various combination treatment protocols. Species covered are divided into small animal (canine, feline), large animal (equine, bovine, caprine, ovine) and miscellaneous species. 相似文献
999.
优素精 ̄(日本科研制药株式会社制品)和盐霉素(山东济宁抗生素厂制品)之抗球虫效力的比较试验。14日龄艾维因肉鸡分4组;Ⅰ、盐霉素组;Ⅱ、优素精组;Ⅲ、感染不给药对照组;Ⅳ、不感染不给药对照组。每组6笼,每笼10只(公母各5只)。优素精和盐霉素均以60ppm之浓度混合于饲料中,自由摄食。16日龄时,Ⅰ、Ⅱ、Ⅲ组分别经口感染E.acervulina,E.maxima和E.tenella混合卵囊,每鸡10.12×10 ̄4。23日龄(感染后7天)解剖全部鸡。依增重,饲料利用效率,血粪,卵囊排出量,球虫病变值和球虫病死亡率判断抗球虫效力。试验结果:优素精组的平均增重(270.08克)和饲料利用率(2.03)是试验各组中最优良的。比不感染不给药对照组优越,生物统计差异显著(P<0.01)。盐霉素组的平均增重(262.42克)和饲料利用率(2.08)虽高于不感染不给药对照组,但其差异不显著(P>0.05)。优素精组的球虫病变值比感染不给药对照组低46.40%,比盐霉素组低36.29%,卵囊排出量比感染不给药对照组低97.25%,比盐霉素组低20.04%。本试验证明,优素精有强烈的抗球虫药效,同时也证明有促进生长,加速增重? 相似文献
1000.
共轭亚油酸对猪胴体品质及作用机理的研究进展 总被引:3,自引:0,他引:3
共轭亚油酸 (CLA)的生物学功能是当前的研究热点 ,已知的功能涉及范围很广 ,包括抑制癌症和肿瘤的形成、减肥、抗动脉粥样硬化、改善免疫功能、降低胆固醇、促进生长等多种生物学活性。近年来 ,CLA在猪上研究应用发现 ,CLA能明显降低体脂、提高瘦肉率 ,具有营养再分配作用。本文就CLA对猪胴体品质的影响及其作用机理作一综述。 相似文献