4UMS-390Ⅱ型木薯收获机的研制

木薯块根是工业上主要的制淀粉原料之一,世界上木薯全部产量的65%用于人类食物,但国内木薯收获机的研制尚未见到相关系统报道.为此,阐述了一种木薯收获机的主要结构、工作原理、主要技术参数及试验结果.试验结果表明,该机型满足设计要求,且能够满足生产要求.     

Numerical Analysis of Acoustic Environment with Finite Element Method

The acoustic environment of highway tunnel is complex and has influences on the driving safety and comfort. In case of emergency, evacuation information is difficult to transfer. Finite element method is used for calculating highway tunnel acoustic modal and attenuation characteristics. The results show that acoustic mode of highway tunnel has symmetry in the horizontal pressure amplitude of symmetry regional is equal and phase is the same or opposite. The higher modal frequency, the greater sound pressure amplitude is, and the effect of tunnel length on modal frequency is smaller. Decay curves of pressure level at each point in the highway tunnel over time are nonlinear. After the source excitation, in 1.5 s, attenuation rate is faster than that of few seconds later and the attenuation time of sound pressure level 30 dB is 5.5 to 7 s.     

大麦不同品种不同播期幼穗分化时期形态诊断研究

 大麦幼穗分化进程与植株外部形态关系密切,1997年对5个大麦品种(品系)、不同播期的幼穗分化与叶龄、叶龄余数和叶枕距的关系进行了初步研究。结果表明,同一品种不同播期幼穗分化各阶段的叶龄基本一致,不同品种同一播期幼穗分化各阶段的叶龄有明显差异,弱春性品种主茎总叶数较多,幼穗分化起步迟,进程慢,春性品种主茎叶数较少,幼穗分化起步早,进程快。应用叶龄、叶龄余数和叶枕距等指标来判断幼穗分化各阶段,对于采取相应的栽培技术措施、促进小穗分化和小花发育都有重要意义。     

歙县枇杷产业化的发展与对策

主要介绍了枇杷的生物学特性和营养价值、药用价值,在分析了歙县枇杷生产现状的基础上,指出了歙县枇杷产业化发展存在的问题,并提出了发展枇杷产业需要通过采取适度规模化生产、合理品种组成、加强产后服务、实现产品深加工和综合利用等对策。     

浅谈自然保护区在湖北生态建设中的地位与作用

随着全国野生动植物保护和自然保护区建设工程的实施 ,自然保护区在我省生态环境建设中的地位与作用越来越重要 ,运用生物多样性管护区的理论指导我省的自然保护区建设将是正确认识自然保护区地位与作用的关键所在。     

反算方位角在计算机编程中的新算法

本文作者根据自己多年的工程实践,对传统的编程方法和现代的编程方法进行了分析,对比并且得出结论。     

Cytoplasmic diversity of the cotton genus as revealed by chloroplast microsatellite markers

The diversity of chloroplast genomes has played an important role, as have those of nuclear and mitochondrial genomes, in the evolution of plants. The sequences of the chloroplast genome supply unsubstituted information for genome analysis. In order to understand the genetic differentiation and relationship of cotton species, we investigated the cytoplasmic diversity of chloroplast genomes in 41 Gossypium accessions with 75 chloroplast simple sequence repeat (cpSSR) markers. The markers were developed from reference sequences of the chloroplast genomes of G. hirsutum and G. barbadense and covered approximately 12.6 kb. Among the 75 markers, 50 were polymorphic, with polymorphism information content values ranging from 0.11 to 0.88. Analyses of the dataset demonstrated that single copy regions were much more informative than inverted repeat regions. The non-coding sequences were well differentiated among these species. For some common cpDNA haplotypes, the E-genome species that may be the oldest of the extant cotton species was deduced. The differentiation of A-genome species lagged behind that of AD-genome species. Neither G. herbaceum nor G. arboreum was the cytoplasmic donor of tetraploid species, strongly suggesting that AD genomes originated from an extinct ancestor of modern A-genome species. We speculate that the genetic differentiation of the chloroplast genome of each cotton species resulted from the dispersal of that species and its adaptations to local ecological conditions. These cpSSR markers provided valuable information to reveal the diversity and differentiation of cotton during evolution.     

采摘机器人位置校正方法研究——基于无线传感网络和超带宽调频方法

超带宽雷达是新近出现的一种高分辨率雷达,当信号带宽和其发射中心频率的比大于0.25时,就被称作超带宽,带宽越大,雷达对目标的分辨能力越高。超带宽雷达具有高分辩能力,如果将其使用在采摘机器人定位导航系统中,可以有效地提高采摘机器人的定位导航精度和效率。为此,提出了一种基于无线传感网络和超带宽调频技术的采摘机器人位置校正方法,并以实际采摘环境作为研究对象,对采摘机器人的位置校正过程进行了测试。测试结果表明:采用超带宽调频无线传感网络方法,定位校正精度要高于传统的定位算法,且定位效率高,对于新型自动化采摘作业机器人的研究具有重要的指导意义。     

改性聚丙烯酸酯包膜控释肥料的控释性能研究

针对应用流化床包衣设备进行水溶性高分子聚合物包膜肥料中试生产中存在的问题,研究了交联剂用量对膜材料表面结构与疏水性能的影响,以及不同后处理工艺对改善包膜肥料控释性能的作用。结果表明,以水溶性高分子聚丙烯酸乳液为主成分的包膜材料中添加交联剂(氮丙啶)的比例由1%(质量百分数,下同)增加至2%,肥料包膜表面结构变得更加平整致密,疏水性能也有所增强,控释效果显著提升。在40℃静水浸泡的9 d时间内前者释放了90%以上的养分,而后者仅释放了约40%的养分。不同后处理工艺对增强包膜肥料的控释性能作用不一。烘箱加热的效果远好于微波处理,且当交联剂添加比例较低(0.3%)时,在一定范围内(60℃~80℃)升高后处理温度,包膜肥料的控释性能显著增强。而当交联剂添加比例增至1%以上时,升温对其控释性能几乎无影响。     

微生物菌肥与化学肥料配施对盈江省藤生长的影响

为了解不同肥料种类及其施肥量对盈江省藤生长的影响,采用L₉(3⁴)正交试验设计对其2年生幼林进行连续3年的微生物菌肥与复合肥和磷肥配施试验。结果表明,3年中不同因素的各水平组合间苗木的地径、株高、叶片数和冠幅均呈现极显著的差异(P<0.01)。施用复合肥和磷肥总体呈现显著(P<0.05)或极显著(P<0.01)地抑制盈江省藤生长的现象。不同肥料配施试验组合的地径、株高和叶片数均大于对照的相应指标。试验期间,单施微生物菌肥0.3~0.6 g/株即可满足盈江省藤生长的需求。