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91.
92.
Brambilla G. Fiori M. Pierdominici E. Antonucci G. Giorgi P. Ramazza V. Zucchi M. 《Veterinary research communications》1998,22(7):457-465
Clinical analyses designed to set welfare parameters were performed on blood drawn from the caudal vein of 14 groups of cattle (young bulls and heifers) (n = 10) from 480 to 550 kg b.w., each group representative of a different farm. The leukocyte formula exhibited a lymphocytopenia in four groups compared with the values from a control group (n = 50). This finding was related to the possible illicit use of corticoids as growth promoters in meat production. The individual plasmas tested negative by two different ELISA kits for corticosteroids, but chemical analyses by LC-MS/APCI (detection limit 0.5 ng/ml) on the pooled plasma of each of the 14 groups revealed the presence of beclomethasone and fluocinolone acetonide in 3 of the 4 suspect farms. These corticosteroids are not always efficiently screened by commercially available immunoassays. The epidemiological reliability of blood analysis as a screening test for such drugs is discussed in the light of the need for quality certification of the whole meat production processes from farm to fork, and for enhanced animal welfare. 相似文献
93.
钱丽艳 《湖南农业大学学报(自然科学版)》1998,25(4)
提出了建立大型激光装置的程序编码的初步方案及需要开展的计算机编码工作内容,并完成了空间滤波器系统的Fourier编码模块,给出了计算图样 。 相似文献
94.
以巴特沃斯滤波器设计为例,论述了MATLAB编程、信号处理工具箱等计算机仿真手段在数字信号处理教学中的应用,分析了数字信号处理与模拟电子技术等先修课程的内在联系。仿真技术的引入,使抽象复杂的数字信号处理理论具体化,从而降低了学生理解知识的难度,收到了很好的教学效果。 相似文献
95.
提出一种基于ARM处理器LPC2212为核心的温室环境监控系统的显示屏设计方案,实现了对温室环境参数的自动巡回显示。对以SD16726芯片为显示驱动电路的显示屏硬件和软件实现进行了详细阐述。 相似文献
96.
通过试验 ,研究了洞庭湖区地下水生物除锰滤池的成熟过程与除锰效果 ,探讨了 pH值、氧化还原电位 (ORP)以及亚铁离子 (Fe2 + )与生物除锰的关系。结果表明 ,石英砂滤池除锰能力与砂层细菌含量密切相关 ;在试验进水水质条件下 ,通过自然培养 ,石英砂生物除锰滤池可在 6 0天内培养成熟 ;在 12m/h的较高滤速下 ,生物滤池仍有良好的除锰、除浊效果和很长的过滤周期 ;当出水 pH为 5~ 8.5时 ,出水含锰量小于 0 .1mg/L ,但当pH <5时 ,出水含锰量随进水 pH值的降低而急剧增加 ;当ORP为 4 30~ 72 0mV时 ,生物滤池具有良好的除锰效果 ;Fe2 + 与生物滤池除锰能力密切相关 . 相似文献
97.
阐述了新型换流变压器及其滤波系统的接线方案和谐波抑制机理.建立了新型换流变压器谐波模型,分析计算了新型换流变压器各绕组的谐波电流分布,实验验证了该模型的正确性.对直流输电开发平台进行了滤波装置实例设计,仿真和实验结果基本一致.证明了新型换流变压器及其滤波系统原理正确,滤波效果好,平台参数选择合理,新系统具有良好的应用前景. 相似文献
98.
99.
Niu Chen Li Yun 《中国林学(英文版)》2006,8(1):32-34
Conventional methods of DNA recovery from agarose gel generally require expensive equipment, extended elution times, or considerable handling of the sample after elution. We developed a simple protocol for a quick and effective recovery of DNA from agarose gels with good yield and quality. Using a Sephadex resin filled spin column, DNA fragments of 500 bp to 6 kb in an agarose gel slice were easily recovered by a 2 min centrifugation. The recovery efficiencies were over 40%-50% and the eluted DNA can be used directly for downstream application, such as polymerase chain reactions (PCR) and restriction enzyme digestion. This method could also be used to recover large DNA fragment (48 kb) without degradation. The use of Sephadex helps to remove small molecular impurities from agarose and it also reduces the chance of clogging the column filter caused by direct contact with agarose. 相似文献
100.
Yuko?FujiwaraEmail author Yoshihisa?Fujii Yutaka?Sawada Shogo?Okumura 《Journal of Wood Science》2004,50(1):35-40
Japanese oak and Japanese beech were sanded by hand with abrasive papers of varying grit number. Two three-dimensional parameters selected to characterize their surface roughness – one parameter for the distribution of roughness-profile peaks and the other for the relative area of the roughness-profile peaks above the threshold height – were compared against tactile roughness. The parameters were obtained from roughness profiles as determined by a robust Gaussian regression filter (RGRF) using seven cutoffs. The RGRF filtering process was adjusted specifically for the evaluation of wood surface roughness. Except for a cutoff wavelength of 0.25mm, the RGRF lent itself well to the determination of roughness profiles. No distortion of roughness profiles occurred around deep valleys, and there was a good correlation between the parameters and tactile roughness.Part of this study was presented at the 2002 Kansai Branch Office lecture meeting of the Japan Society for Precision Engineering, Kyotanabe, August 2002 相似文献