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1.
用全薯块吸头刺伤接种法测定时,较理想的测定条件为:每接种点接种0.1ml浓度为10~2~10~5CFU/ml菌悬液,随后在21±5℃~31±5℃(依所用菌株而定)下保持2~3天,以接种点腐烂斑的最大直径作记载标准。用新鲜薯片法测定时,除接种浓度为10~2~10~3CFU/ml,保持时间为1~2天及以侵染限值作评价标准外,其余条件和全薯块吸头刺伤接种法相同。当用皮孔浸渍法接种时,薯块在10_6CFU/ml菌悬液中浸5分钟,然后使薯块表面保持连续水膜,3~5天后测量薯块表面腐烂面积。上述3种方法都必须有20个以上重复,并使用大小一致、无伤无病的成熟薯块。 相似文献
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选用S7-200 PLC,结合组态王人机交互界面,运用激光轮廓和色泽集成扫描技术设计了一种实木板材双面检测系统。主要介绍了该检测系统的工作原理和工作流程,简述了检测装置的整体结构及其传动、升降、检测、行程控制等主要模块的设计及电气控制系统总体设计。试运行表明,该装置集合PLC和组态王的优势,利用激光扫描技术,可实现对板材双面检测过程的实时控制;板材检测运用色泽与轮廓相结合,有效地解决了现有实木板材单面检测系统不能全面地反映实木板材表面缺陷状况的难题。该设计可为实木板材表面缺陷检测中三维轮廓检测技术的进一步应用提供有益参考。 相似文献
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《Veterinary parasitology》2015,207(1-2):1-6
The success of a Toxoplasma gondii surveillance program in European pig production systems depends partly on the quality of the test to detect infection in the population. The test accuracy of a recently developed serological bead-based assay (BBA) was investigated earlier using sera from experimentally infected animals. In this study, the accuracy of the BBA was determined by the use of sera from animals from two field subpopulations. As no T. gondii infection information of these animals was available, test accuracy was determined through a Bayesian approach allowing for conditional dependency between BBA and an ELISA test. The priors for prevalence were based on available information from literature, whereas for specificity vague non-informative priors were used. Priors for sensitivity were based either on available information or specified as non-informative. Posterior estimates for BBA sensitivity and specificity were (mode) 0.855 (Bayesian 95% credibility interval (bCI) 0.702–0.960) and 0.913 (bCI 0.893–0.931), respectively. Comparing the results of BBA and ELISA, sensitivity was higher for the BBA while specificity was higher for ELISA. Alternative priors for the sensitivity affected posterior estimates for sensitivity of both BBA and ELISA, but not for specificity. Because the difference in prevalence between the two subpopulations is small, and the number of infected animals is small as well, the precision of the posterior estimates for sensitivity may be less accurate in comparison to the estimates for specificity. The estimated value for specificity of BBA is at least optimally defined for testing pigs from conventional and organic Dutch farms. 相似文献
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New sugarcane cultivars are continuously developed to improve sugar industry productivity. Despite this sugarcane crop models such as the ‘Sugar’ module in the Agricultural Productions System sIMulator (APSIM-Sugar) have not been updated to reflect the most recent cultivars. The implications of misrepresenting cultivar parameters in APSIM-Sugar is difficult to judge as little research has been published on the likely values of these parameters and how uncertainty in parameter values may affect model outputs. A global sensitivity analysis can be used to better understand how cultivar parameters influence simulated yields. A Gaussian emulator was used to perform a global sensitivity analysis on simulated biomass and sucrose yield at harvest for two contrasting sugarcane-growing regions in Queensland, Australia. Biomass and sucrose yields were simulated for 42 years to identify inter-annual variability in output sensitivities to 10 parameters that represent physiological traits and can be used to simulated differences between sugarcane cultivars. Parameter main effect (Si) and total effect (STi) sensitivity indices and emulator accuracy were calculated for all year-region-output combinations. When both regions were considered together parameters representing radiation use efficiency (rue), number of green leaves (green_leaf_no) and a conductance surrogate parameter (kL) were the most influential parameters for simulated biomass in APSIM-Sugar. Simulated sucrose yield was most sensitive to rue, sucrose_fraction (representing the fraction of biomass partitioned as sucrose in the stem) and green_leaf_no. However, climate and soil differences between regions changed the level of influence cultivar parameters had on simulation outputs. Specifically, model outputs were more sensitive to changes in the transp_eff_cf and kL parameters in the Burdekin region due to lower rainfall and poor simulated soil conditions. Collecting data on influential traits that are relatively simple to measure (e.g. number of green leaves) during cultivar development would greatly contribute to the simulation of new cultivars in crop models. Influential parameters that are difficult to measure directly such as transp_eff_cf and sucrose_fraction are ideal candidates for statistical calibration. Calibrating crop models either through direct observation or statistical calibration would allow crop modellers to better test how new cultivars will perform in a range of production environments. 相似文献
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通过对下支点固定式油缸加载工况下拖拉机液压悬挂装置的受力分析,推导出这种国内外常用试验台设计方案的加载误差,并给出试验数据的修正方法以补偿该项误差的影响。 相似文献
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淡水鲳对九种常用鱼药的敏感性试验 总被引:3,自引:0,他引:3
本文报告了敌百虫、孔雀石绿、硝酸亚汞、漂白粉、呋喃唑酮、生石灰和食盐等常用鱼药对淡水鲳的安金浓度依次为0.028ppm、0.0312ppm、0.0865ppm、0.699ppm、16.22 ppm、19.5 ppm、1040 ppm。淡水鲳分别在亚甲基蓝2.1 ppm,硫酸铜硫酸亚铁合剂(5∶2)5.6ppm药液中浸浴240小时,未见异常反应。 相似文献
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