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11.
据1981~1983年9个哈密瓜生产基地根颈部病害的病原成份调查表明,哈密瓜疫病的优势种为掘氏疫霉菌(Phytophthora drechsleri Tucker.)。为澄清在新疆掘氏疫霉的寄主范围,1989~1990年用1981年采自鄯善县哈密瓜上分离的单孢(Phy-6)菌株,在温室平均温度25~28℃条件下对5科25种自然根颈感病的栽培作物作接种试验。结果表明,本菌是葫芦科大多数作物的重要致病菌,并可侵染棉花和红花;在有伤口条件下可以侵染南瓜、西葫芦和茄株;对苦瓜、丝瓜,豆科作物的豇豆、四季豆、菊科的向日葵、茄科的蕃茄、辣椒、烟草、马铃薯、蔷薇科草莓(植株)等均不能致病。 相似文献
12.
LUO Xiao-gang PENG Cheng-lin ZHENG Xiao-lin LI Qing-huiistry of Education College of Bioengineering Chongqing University Chongqing Chin 《保鲜与加工》2003,(12):51-54
We research fractal characteristics of ECG signal, and find that it is logarithmic linear relationship between the boxes number covering signal and box scale. It is shown that ECG signal have some characteristics. Further more, we discover that fractal dimensions at QRS site are higher than others when using a time windows to detect signal. Based on this foundation, we raise a location algorithm of QRS waves which is based on fractal boxes dimension detection methods. The application results of this algorithm show that it can get rid of noise in ECG effectively with high speed, so this algorithm can be used in real time detection of ECG signal. 相似文献
13.
国产MJ3210小型木工跑车带锯机锯解正交试验分析 总被引:1,自引:0,他引:1
采用正交试验设计法,对国产MJ3210小型木工跑车带锯机的锯解质量进行研究。通过实测马尾松锯材尺寸偏差、表面粗糙度等参数,得到其最佳的进料速度、锯解厚度和锯卡高度的组合方案。结果表明,该设备具有结构简单、出材率高、锯解精度高、质量好、成本低和生产效率高等优点。 相似文献
14.
15.
0.05MpH9.6碳酸盐缓冲液和0.05MPH13NaOH溶液作为包被液,分别用于间接ELISA检测乙型五号病病毒抗体。结果表明,用0.05MPH13NaOH溶泡包被可完全灭活五号病病毒抗原而用0.05MPH9.6碳酸盐缓冲液却有87%的五号病病毒抗原未被杀灭;用于检测时,以0.05MPH13NaOH溶液为包被液在敏感性及检测结果的梯度方面都优于用0.05MPH9.6碳酸盐缓冲液。 相似文献
16.
首次应用XXG-A型心血管功能测试仪以无创伤检测技术对16例妊娠黄牛22项血液动力流变学指标做了检测,并首次对怀孕黄牛的血液动力流变学特征做了报道。 相似文献
17.
N. J. M. Roozen J. W. L. Van Vuurde 《European journal of plant pathology / European Foundation for Plant Pathology》1991,97(5):321-334
Various compounds and basal media were tested for their suitability to create a semi-selective medium for isolation ofClavibacter michiganensis subsp.sepedonicus (Cms) from cattle manure slurry containing c. 108 colony forming units (cfu) per ml.Plating efficiency of Cms in yeast glucose mineral medium (YGM) was 104% compared with yeast peptone glucose medium. Nalidixic acid, polymyxin B sulphate and the experimental disinfectant S-0208 inhibited colony growth of cattle slurry bacteria as compared with Cms in YGM. The optimal concentration of these inhibitors in combination was determined by modified agar diffusion tests and by pour plating in 24-well tissue culture plates. The semi-selective medium YGMI consisted of YGM supplemented with nalidixic acid (2 mg/l), polymyxin B sulphate (30 mg/l) and S-0208 (125 mg/l). Plating efficiency varied for Cms between 50.9 and 69.6%, for cattle slurry bacteria between 1.8 and 2.5% and for saprophytes from potato heel end extracts between 11.5 and 27.4%.Differentiation of Cms colonies from other colonies was based on their small and bluish colony morphology in pour plates and on immunofluorescence colony-staining (IFC). IFC of a pure culture of micro colonies of Cms in YGM was possible after one day incubation (colonies c. 5 cells). Green background fluorescence in the agar gels was prevented by addition of Tween 20 (0.1%) to the washing buffer and the use of 1% agar gels. IFC of macro colonies of Cms in YGMI, visible with 4x objective magnification, was possible after 4 days. The detection level of the target organism in artificially inoculated cattle slurry in YGMI based on colony morphology varied between 1.4×103 and 2.3×104 cfu per ml of cattle slurry. Miniaturized plating combined with IFC, using wells in tissue culture plates (=16 mm), proved suitable for detection, but was c. 30 times les sensitive. The recovery of Cms was negatively correlated with the number of saprophytic colonies in the agar plates (R
2=0.74). 相似文献
18.
用组织培养技术将富士苹果茎尖外植体建立在MS培养基中,形成试管苗。取4—6周龄的茎与愈伤组织,徒手切取约1mm厚的横切面,印迹在硝化纤维膜上。印迹组织经封闭后,与CLSV碱性磷酸酶标抗体反应。对反应结果进行显色。感染CLSV的印迹组织呈紫色反应,正常组织无显色反应。结果表明,该方法十分容易检测印迹组织中的CLSV。带毒愈伤组织较茎的显色反应敏感,显色反应时间仅为茎的一半(15min)。CLSV在愈伤组织中有两种分布情况:一是所有组织均有显色反应;二是呈不均匀分布。CLSV在茎组织中有三种分布情况:第一,除髓部外,表皮、皮层及维管系统中均有分布;第二,不均匀分布,CLSV集中分布于表度组织中,在皮层及韧皮部仅有少量分布;第三,“嵌合”分布,即同一种组织中部分组织带毒,部分为正常组织。 相似文献
19.
The historical range of variability (HRV) has been suggested as a coarse filter approach to maintain ecosystem sustainability
and resiliency. The historical range of variability in forest age structure for the central eastern Cascade Range in Washington
State, USA was developed from historical fire return intervals and the manner in which fire acted as both cyclic and stochastic
processes. The proportions of seven forest structural stages calculated through these processes were applied to the area of
each forest series within the central eastern Cascades landscape. Early successional forest stages were more common in high
elevation forest than low elevation forest. The historical proportion of old growth and late successional forest varied from
38 to 63 percent of the forested landscape. These process-based estimates are consistent with those developed from forest
structural information. HRV is a valuable planning tool for ecosystem conservation purposes, but must be applied to real landscapes
with consideration of both temporal and spatial scale.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
20.
After about 25 years of intensive research a substantial moment of information has accumulated on the basic biology of Prostephanus truncatus in stored products. This article reviews the literature on the geographical distribution, biotypes, symbiotic associations, mating and flight behaviour, oviposition, and development on both agricultural and non-agricultural hosts. The current knowledge about the nutritional biology (including the role of symbionts) and host finding behaviour (including the inter-linked roles of plant chemicals and the insect's own pheronones) are highlighted as research areas which deserve future attention. In addition, few studies have been conducted to determine the extent to which the biology of P. truncatus permits it to survive and reproduce in non-agricultural environments. These areas of study should be pursued as possible routes to providing more effective integrated pest managements strategies for the larger grain borer. 相似文献