水处理设备的单片微机控制器

介绍了用 89C2 0 51单片机系统对水处理设备工作的控制 ,使水处理设备能全面、可靠、无人值守地工作 ,达到智能的档次 .文中描述了水处理设备控制器的软件设计和硬件设计     

基于单片机的沼气发酵装置增温控制系统设计

北方沼气系统全年产气的关键是冬季加热增温问题.为此,以生物质炉为热源,通过对循环水的加热,用单片机控制加热水泵的增温系统,研究设计了系统的整体功能以及硬件和软件.该系统具有一定的智能性,保证了沼气系统在北方冬季时的正常运行,提高了产气量.     

中华猕猴桃单芽绿枝扦插试验

中华猴猕桃单芽绿枝扦插试验结果表明:1.采自组织培养的猕猴桃植株的插穗比采自嫁接植株的插穗更易生根,且发根早,根量大;2.插穗经不同浓度的吲哚丁酸(IBA)处理后可不同程度地促进生根,处理以100ppm浸泡插穗基部20小时为最佳.生根率可达100%.     

烘炉温度无线检测系统设计

提出了一种检测烘炉温度的无线数字检测系统.该系统将无线收发模块nRF905与单片机系统相结合,实现无线温度检测,其也适用于其他领域设备的温度无线测量.     

基于FLUENT的单-双涡室离心泵径向力分析

以某电厂3715L型脱硫泵为模型,应用商业软件FLUENT,采用标准k-ε湍流模型和SIMPLEC算法,对单-双涡室离心泵内部流场进行模拟,分析了这两种泵静压力和速度场的分布规律,并对径向力进行了计算分析.通过对比分析发现,单涡室离心泵在非设计工况点时隔舌两侧区域出现较大压差,作用于叶轮产生径向力,小流量时叶轮出口出现不对称的高速流体;双涡室结构能够有效地改善非设计工况点时压水室能量的转化,小流量时叶轮出口的高速液体呈对称分布,从而降低了压水室压差,起到了平衡径向力的作用;通过计算发现,偏离工况点时双涡室结构设计能有效地减小径向力.数值模拟的结果与现有理论的基本吻合,实际运行情况稳定,可以为更好地认识和设计双涡室离心泵提供依据.     

基于芯样的沥青路面抗剪性能评价指标

以沥青路面的取芯芯样为研究对象,采用动载单轴贯入试验方法,通过有限元理论分析和对比试验确定了试验条件和参数,确定以一定作用次数下的贯入深度作为指标,能够较好地评价沥青路面的抗剪切性能.     

Occurrence of microsatellites in spinach sequences from computer databases and development of polymorphic SSR markers

Microsatellites are valuable tools as molecular markers in plant breeding. To establish genetic linkage maps or for population studies, information about the occurrence and usability of microsatellite markers in different species is necessary. Sequences of spinach Spinacia oleracea from computer databases were therefore searched for the presence of microsatellites. Sixty simple sequence repeats were found in 237 spinach sequences with a total of 349.4 kb DNA. After removing duplicated sequences, 50 different microsatellites with various motifs remained. Differences between nuclear and chloroplast DNA were not in the number of microsatellites but in their type and length. Chloroplast sequences from spinach contain only short strings of A and AT repeats, whereas nuclear sequences show a wider variety of motifs. Flanking primers for polymerase chain reaction (PCR) analysis were designed for 13 of these microsatellites and tested with two different varieties of spinach. Twelve primer pairs gave amplification products and seven of these showed polymorphisms in the variety ‘Wiremona’ but only one in the variety ‘Monatol’. These markers may be used for linkage analysis or population studies in spinach.     

马传染性贫血病毒弱毒株LTR的克隆及序列分析

从马传染性贫血病毒（ＥＩＡＶ）弱毒株感染的驴胎皮肤（ＦＤＤ）细胞中提取前病毒ＤＮＡ，以其为模板，通过ＰＣＲ扩增出ＥＩＡＶ弱毒株的ＬＴＲ，并将其克隆到载体质粒ｐＵＣ１９中。经酶切分析，ＰＣＲ及Ｓｏｕｔｈｅｒｎ杂交筛选、鉴定，获得含有ＥＩＡＶ弱毒株ＬＴＲ片段的重组质粒ｐＬＴＲ。对该质粒的序列分析发现，在中国ＥＩＡＶ弱毒株ＬＴＲ的Ｕ３区含有４个与细胞转录因子结合的位点，其中有３个ＰＵ．１位点和１个ＡＰ－１位点，Ｕ３区还存在１个ＴＡＴＡＴＡＡ启动子序列；Ｒ区长为８１ｂｐ，含有１个帽位点ＧＧ和１个Ｐｏｌｙ（Ａ）信号序列ＡＡＴＡＡＡ；在帽位点下游是１个病毒Ｔａｔ蛋白结合位点，即ＴＡＲ位点；Ｕ５区长为３９ｂｐ。中国ＥＩＡＶ弱毒株ＬＴＲ序列与国外发表的其他毒株序列相比，在ＬＴＲ的一些调控部位有变异发生，中国ＥＩＡＶ弱毒株与美国ＥＩＡＶ原型株（Ｗｙｏｍｉｎｇ株）ＬＴＲ区核苷酸序列有１８．７２％的差异。     

多通道石英晶体测温仪的设计与实现

阐述了石英晶体测温原理及石英晶体用于测温的优点，对如何降低晶体测温系统的硬件成本和提高仪器测温准确度的措施作了较深入的探讨，实现了一种性能价格比较高的微机化八通道石英晶体测温仪器设计。     

Ein allgemeiner Ansatz zur Quantifizierung des Einflusses der Güte der Sätechnik auf den Flächenertrag

A general approach to determine the effect of accuracy of sowing technique on yield per area
Caused by nonperfect seed placement accuracy of sowing machines as well as by many other abiotic and biotic factors the resulting plant stands exhibit nonregular plant distributions. Based on several simplifying assumptions a stochastic approach provides a quantitative determination of the effects of accuracy of sowing technique on yield per area. In this approach, two random variables are assigned to each individual plant: single plant yield E and single plant area A, which is calculated in this paper by the construction and quadrature of the so-called Thiessen-polygons. The yield per area F is calculated as the expectation of the ratio E/A. By assuming a deterministic mathematical relationship between E and A, the calculation of F reduces to the calculation of the expectation of a function of only one random variable A. A simple approximation with sufficient accuracy for many applications only depends on the mean and on the variance of the areas of the individual plants. For demonstration purposes, the theoretical approaches and results have been finally applied to three data sets for drilled seeds of winter oilseed rape (plant density: 60 plants/m² and distance between rows: 10 cm). These data sets exhibit different accuracies of the longitudinal distributions within rows which have been quantitatively measured by the coefficient of variation for the distances between plants within rows: Yield depression increases with an increasing variability of plant distances within rows.