种子介电分选机进料滚筒设计计算的理论分析

通过对种子介电分选机分选工艺过程的分析，根据介电分选对种子进料的要求，提出了种子介电分选机进料滚筒设计理论及主要参数的确定方法。通过分析种子的大小和形状特征，提出了进料滚筒系列化产品设计的理论方法。     

水平摘穗辊与可退让拨禾器组合式玉米摘穗机构研究

传统玉米收获机的摘穗辊结构长度和质量较大。不易与我国大量拥有的中小型拖拉机悬挂配套，而采用短摘穗辊后果穗损失增加。针对这一问题，研制出水平摘穗辊与可退让拨禾器组合式摘穗机构。文中论述了这种摘穗机构的结构，在分析研究其基本原理和作业性能的基础上。试验验证了摘穗辊和拨禾器结构参数对作业性能的影响。     

花椒籽剥壳机的设计

最新的研究表明,花椒油具有很高的营养价值.为了提取花椒油,必须先去除花椒的表壳.为此,设计了花椒籽剥壳机.花椒籽剥壳机的基本原理是花椒籽在齿辊的作用下破碎,破碎后的主要成分有花椒仁和花椒壳,还有未破碎的花椒籽.由于它们密度不同,利用风机将花椒壳先分离出去;再利用它们粒度的不同,将花椒仁和未破碎的花椒籽分离开来.     

Development and Application of Computer Aided Roll Design System for Thread-steel-bar

Roll pass design is one of the important content of making the rolling technology of section steel.The traditional pass design relies mainly on artificial experience,which brings some tedious calculation and great consumption of raw materials.In order to improve production efficiency,the constitute and the design methods of the roll system for thread-steel-bar are analyzed during stretching,further rolling and finished rolling.The mathematical models and the(experience) formulas used for the roll design in the past are revised.The computer aided roll design system is developed for thread-steelbar based on the structural means of compiling program.The authors adopt Visual Basic6.0 as a visual program tool,and combine the basic design theory of the thread-steel-bar's roll and the practical experience.The system can shorten the design cycle of the new product development,and reduce the energy consumption of the rolling mill and the distribution of production.     

滚割喂入式卧轴甩刀香蕉假茎粉碎还田机设计与试验

由于香蕉假茎粗大、含水率高,且富含纤维素与半纤维素,现有的粉碎还田机大多存在秸秆粉碎不彻底、刀具易磨损、机器作业效率低等问题。针对上述问题,该文设计了一种滚割喂入式卧轴甩刀香蕉假茎粉碎还田机,描述了该机推倒装置、滚割喂入装置、粉碎装置以及整平装置等主要部件的结构,并对粉碎刀进行了运动和受力分析,确定了其关键参数。田间试验表明:该机器在拖拉机前行速度为2.16~3.60 km/h、后动力输出轴转速为720 r/min时,工作效率为0.42~0.46 hm2/h、油耗量为21.4 L/hm2、香蕉假茎粉碎合格率为96.6%、香蕉假茎平均切碎长度为57 mm,均满足秸秆粉碎还田农艺要求。该研究为中国南方香蕉种植区秸秆粉碎还田机的发展与推广提供了参考。     

回转高副机构的动态优化设计原理研究

本文从两圆柱构件直接接触形成迴转高副机构的实际情况出发,分析其失效的基本原因,提出了系统参数的优化问题,建立了在动态情况下的设计原理。     

诱根钵和栽培基质对紫穗槐幼苗生长的影响

为了促进苗木须根的生长,实现全年、全冠移栽,以凹凸壁多孔盆为诱根钵,研究了不同基质配比对紫穗槐幼苗生长的影响。结果表明:诱根钵苗在基质1中的叶面积、叶片数、株高分别高于普通钵59.3%、20.3%、53.1%;但其他基质作用不明显。诱根钵对幼苗根系的诱导作用更大,且基质1中效果最好,主根长、须根数、根系干质量分别高于普通钵71.7%、77.0%、30.7%。诱根钵与基质1和基质2的组合使植株干质量和鲜质量增加,其中基质1中的植株地上鲜质量、地下鲜质量、地上干质量、地下干质量分别高于对照58.4%、29.5%、91.5%、30.7%。建议该容器的开发应与基质和管理技术配套。     

Pcr Assay for specific detection of European stone fruit yellows phytoplasmas and its use for epidemiological studies in France

DNA amplification by polymerase chain reaction was used to specifically detect phytoplasmas associated with severe decline diseases of European stone fruits. PCR primers were designed according to the partial sequence of a nonribosomal genomic fragment of European stone fruit yellows phytoplasmas obtained by direct sequencing of a specific PCR product. A PCR assay was developed which resulted in specific amplification of a 237 bp-DNA fragment from total DNA extracts derived from over 300 stone fruit samples. No PCR product was obtained with DNA from healthy controls or plants diseased with various other phytoplasmas, e.g. the closely related apple proliferation and pear decline phytoplasmas. Phytoplasma infection was checked in all samples by PCR amplification with universal ribosomal primers. Detection rate with specific and universal primers was correlated by 97%. European stone fruit yellows phytoplasmas were detected in samples of 114 out of 139 examined orchards which represent the major stone fruit growing regions of France. Typical symptoms like chlorotic leaf roll in summer and off-season growth in winter were correlated by 95% to the presence of phytoplasmas. However, phytoplasmas were also detected in 51% of samples derived from trees showing non-specific symptoms. A comparison study including 201 samples showed that 81% of the PCR-positive samples were also tested positive using fluorescence microscopy with DAPI staining.