全文获取类型
收费全文 | 429篇 |
免费 | 24篇 |
国内免费 | 20篇 |
专业分类
林业 | 28篇 |
农学 | 11篇 |
基础科学 | 9篇 |
39篇 | |
综合类 | 192篇 |
农作物 | 35篇 |
水产渔业 | 28篇 |
畜牧兽医 | 83篇 |
园艺 | 19篇 |
植物保护 | 29篇 |
出版年
2023年 | 3篇 |
2022年 | 7篇 |
2021年 | 16篇 |
2020年 | 11篇 |
2019年 | 15篇 |
2018年 | 9篇 |
2017年 | 24篇 |
2016年 | 5篇 |
2015年 | 11篇 |
2014年 | 18篇 |
2013年 | 20篇 |
2012年 | 33篇 |
2011年 | 42篇 |
2010年 | 35篇 |
2009年 | 38篇 |
2008年 | 27篇 |
2007年 | 24篇 |
2006年 | 19篇 |
2005年 | 20篇 |
2004年 | 13篇 |
2002年 | 7篇 |
2001年 | 9篇 |
2000年 | 6篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 6篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1979年 | 4篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1968年 | 1篇 |
1963年 | 1篇 |
1959年 | 1篇 |
1953年 | 1篇 |
1948年 | 1篇 |
1910年 | 1篇 |
排序方式: 共有473条查询结果,搜索用时 269 毫秒
11.
Antimicrobial sensitivity testing of Australian isolates of Bordetella avium and the Bordetella avium-like organism 总被引:1,自引:0,他引:1
SUMMARY: The in-vitro sensitivity of 16 Australian isolates of Bordetella avium and 15 isolates of B avium -like organism to 11 antimicrobial agents or combinations of agents was determined using a microtitre plate system to establish minimal inhibitory concentrations. All the B avium isolates were sensitive to ampicillin but resistant to erythromycin, lincomycin, spectinomycin, sulphamethoxazole, trimethoprim, and lincomycin + spectinomycin. Most of the B avium isolates were sensitive to tetracycline and resistant to streptomycin and sulphadiazine. All the B avium -like isolates were resistant to ampicillin, erythromycin, lincomycin, spectinomycin, streptomycin, tetracycline, trimethoprim, and lincomycin + spectinomycin. Most B avium -like isolates were sensitive to sulphadiazine, sulphamethoxazole and trimethoprim-sulphamethoxazole. 相似文献
12.
马尾松毛虫Dendrolimus punctatus Walker是马尾松林重要害虫。林间应用超轻型飞机大面积喷洒溴氰菊酯超低容量喷雾、白僵菌纯孢子油剂、菌药混合液超低容量喷雾以及喷洒白僵菌菌粉,其防治效果分别为96.5%、85.7%、95.6%、86.5%。上述的防治措施可作为单独的措施或综合防控中的配套措施使用,同时应用飞机防治解决了树高、林密、水源缺乏、劳力工资昂贵等条件给防治工作带来的困难,是一种适应林区林业生产整体水平而又快速、高效、经济的防治手段。 相似文献
13.
14.
试验设21个日粮组, 蛋白质、脂肪、碳水化合物梯度变化范围分别在33% ~ 51%、3% ~ 18%、23% ~ 32%。在水温( 25. 25 ? 1. 91) e 条件下, 在水泥池中对平均体重为( 2. 01 ? 0. 04) g的360尾齐口裂腹鱼进行了60 d的生长试验, 研究日粮中蛋白质、脂肪和碳水化合物对齐口裂腹鱼生长、体组成和肝脏组织的影响。结果表明: 各组鱼特定生长率随着日粮蛋白质水平的增加而增加; 体蛋白含量不受日粮组成的影响, 体脂肪随着日粮脂肪水平的增加而增加, 体碳水化合物受日粮碳水化合物的影响极显著, 而不受日粮蛋白质和脂肪的影响。齐口裂腹鱼幼鱼能耐忍23% ~ 26%的碳水化合物水平, 且能利用6% ~ 12%的日粮脂肪。基于齐口裂腹鱼幼鱼对日粮碳水化合物和脂肪含量需求分别为23% ~ 26%和6% ~ 12%时, 蛋白质需求量为42% ~ 48%, 能蛋比为41. 3 kJ/g。 相似文献
15.
16.
AIM:To elucidate the molecular mechanisms of lipoic acid (LA) on redox regulation and digestive function in intestine of C57BL/6 mice fed high fat diet (HFD).METHODS:C57BL/6 mice were randomly assigned to one of three groups (n=8).The control group consumed an ordinary diet.The other two experimental groups were fed with a high fat diet, high fat plus 0.1% LA.After 6 weeks, the activities of digestive enzymes were examined.In order to evaluate the antioxidant status of the mice, superoxide dismutase (SOD), malondialdehyde (MDA), total antioxidant capacity (TAC) and reactive oxygen species (ROS) in intestinal homogenate were measured.To investigate the molecular mechanisms underlying the effects of LA, the gene expression profiles in intestine were examined using the GeneChip microarray system.RESULTS:A depressed antioxidant defense system, accompanied by digestive and absorptive function impairment, was observed in HFD-fed mice.These changes were partially restored in the LA-treated group.DNA microarray analysis of intestine showed that LA ingestion up-regulated the expression of genes related to free-radical scavenger enzymes, digestive enzymes and transporters.CONCLUSION:Treatment with LA improves redox homeostasis and the function of intestine in mice fed HFD.The mechanism may involve preventing oxidative stress by scavenging ROS directly and increasing those of free-radical scavenger enzymes gene expression indirectly. 相似文献
17.
G. LE TRAON S. BURGAUD & L. J. I. HORSPOOL 《Journal of veterinary pharmacology and therapeutics》2009,32(3):213-218
Long-term oral treatment with cimetidine is recommended to reduce vomiting in dogs with chronic gastritis. Despite this, few studies have specifically examined the plasma disposition and pharmacokinetics of cimetidine in dogs, particularly following repeated oral administration. The pharmacokinetics of cimetidine following oral administration as tablets was investigated in healthy dogs. Cimetidine was absorbed rapidly post-treatment ( t max = 0.5 h). A mean absolute bioavailability of 75% was calculated following a single oral administration of 5 mg cimetidine/kg body weight. After intravenous administration, a plasma half-life of 1.6 h was calculated. Repeated oral administration at the recommended dose rate and regime (5 mg/kg body weight three times daily) for 30 consecutive days did not lead to any accumulation of cimetidine in plasma. Food intake concomitant with oral administration of cimetidine delayed ( t max = 2.25 h) and decreased the rate and extent of absorption ( AUC ) by about 40%. Cimetidine was well absorbed in fasted dogs. Administration of food decreased the bioavailability of cimetidine by 40%. Cimetidine does not accumulate over time in plasma when administered long term to dogs. 相似文献
18.
TANG Lu PEI Yue-hong ZHANG Nan LE Wei-dong FAN Dong-sheng DENG Min ZHANG Jun 《园艺学报》2009,25(12):2441-2446
AIM: To explore the mutual effect of co-culture of wild-type astrocytes (ASC) and motor neurons VSC4.1 (VSC) on the respective ability to produce reactive oxygen species (ROS). METHODS: The inhibition rates of cell growth in ASC and VSC in co-culture or independent culture was detected after exposed to excitatory stimulus by MTT method. Real-time observation of ROS production by ASC and VSC labeled with Hoechst 33342 was detected by confocal microscopy under the conditions of co-culture or independent culture. RESULTS: Higher concentration of glutamate induced a higher inhibition rate in mixed cell growth than that in ASC alone, while lower concentration of glutamate induced a higher inhibition rate in mixed cell growth than that in VSC only. Real-time observation by confocal microscopy showed that ROS production by VSC under the condition of co-culture, which showed a notable increase at 15 min, was significant less than that in independent culture, which peaked at 5 min and was gradually decreased. ROS production by ASC in co-culture began to increase significantly at 10 min. CONCLUSION: Compared to independent culture, ASC reduces the resting ROS production by co-cultured with VSC, while ASC prolongs the duration of ROS production by VSC after exposed to excitatory stimulus. 相似文献
19.
20.