Design of a Tree Ring Structure Analysis System to Estimate the Accurate Age of Tree Species in Sri Lanka

Determination of an age in a particular tree species can be considered as a vital factor in forest management. In this research we have introduced a novel scheme to determine the accurate age of the tree species in Sri Lanka. This is initially developed for the tree species called‘Hora’ (Dipterocarpus zeylanicus ) in wet zone of Sri Lanka. Here the core samples are extracted and further analyzed by means of the different image processing techniques such as Gaussian kernel blurring, use of Sobel filters, double threshold analysis ,Hough line transformation and etc. The operations such as rescaling, slicing and measuring are also used in line with image processing techniques to achieve the desired results. Ultimately a Graphical user interface (GUI) is developed to cater for the user requirements in a user friendly envi-ronment. It has been found that the average growth ring identification accuracy of the proposed system is 93% and the overall average accuracy of detecting the age is 81%. Ultimately the proposed system will provide an insight and contributes to the forestry related activities and researches in Sri Lanka.     

钢渣铁矿物分选技术现状及发展趋势分析

本文综述了钢渣含铁矿物分选技术发展概况并进行了对比分析,笔者认为应加强磁选技术发展,尤其是细粒钢渣磁选装备、磁选工艺的完善.同时,提出以颗粒物质力学体系为核心研究磁选过程颗粒微观特性,可有效指导磁选实践.     

湖北某地金红石选矿新工艺试验研究

根据湖北某地粗粒嵌布的金红石矿的性质特点,在工艺矿物学和详细条件试验研究的基础上,制定了一种新的选矿工艺流程(磁选-脱泥-浮选),先对矿石磁选抛尾,脱泥后进行浮选,再对浮选精矿进行除杂处理,最终获得高品质的金红石精矿,其品位在90%以上,回收率70%以上,显示出该工艺流程的合理性及先进性,对同类矿石具有一定的参考价值。     

一种弹体惯性姿态测量数据处理平台设计

摘要：针对某弹体的惯性测姿系统中存在数据量大、处理时间短的问题,采用DSP+FPGA架构,结合FPGA与DSP在不同算法处理上的优势,设计并实现一种弹体惯性姿态测量数据处理平台。本文详细介绍数据输入输出、FPGA处理、DSP核心处理和电源管理系统主要组成部分的设计,简述PCB设计中的处理和部分FPGA程序。实际测试结果表明,该数据处理平台稳定性强、处理性能极好,能够成功应用到某弹体的惯性测姿数据处理系统中,具有很高的工程实用价值。     

精密齿轮传动RV减速器研究现状

RV减速器因具有传动精度高、回差小和寿命长等优点,被广泛应用于精密机械系统中。梳理了国内外RV减速器的研究现状,展示了RV减速器传动误差、回差、扭转刚度、磨损寿命和加工工艺方面研究成果,分析对比国内外现阶段RV减速器产品性能,发现国产产品在精度保持性和产品一致性方面与国外仍存在差距。最后从研究层面对国内RV减速器的发展提出了针对性建议。     

负压力角弧齿离合器铣齿机关键结构设计与加工仿真

负压力角弧齿离合器因承载能力强、啮合性能好、传动可靠性高等优势,被广泛应用于重型卡车驱动桥主减速器总成中。对负压力角弧齿离合器加工用的专用铣齿机的关键部件设计技术进行研究,构建铣齿加工数学模型,根据加工特点开展刀具箱、工件箱的结构功能分析,基于仿真软件建立等效机床模型,编制加工程序完成凸面齿与凹面齿的加工仿真与分析,验证了铣齿机设计方案的正确性。     

HRB500高强度钢筋剥肋倒角装置设计与研究

针对传统加工方式会损伤大直径HRB500高强度钢筋强度性能等问题,考虑加工要求及形状特点,设计能够完成铣端面、剥肋、倒角的剥肋倒角机整体结构和加工工艺。根据高强钢筋材料的性能,选定刀具具体参数,确定复合刀具的加工工艺参数。设计钢筋轴向定位夹紧装置,并对夹紧力进行计算。采用以伺服电机作为动力源的传动系统,进行传动系统的主要参数计算和电机的计算与选型。利用ANSYS软件进行切削过程的有限元分析,获得了切削过程中刀具的应力变化曲线及其应力变化云图。实验结果表明：所设计钢筋剥肋倒角机可应用于高强度钢筋加工领域,并且切削效果良好,能够很好地适用于各个工序。     

Processing and mechanical properties of hydroxyapatite–polysulfone laminated composites

Designing biocomposites that mimic bone with specific mechanical properties of toughness and elastic modulus is a long-standing challenge in the biomaterials field. Traditional biocomposites comprise polymer matrices reinforced with ceramic particles. Laminated composites are structures also found in nature that can offer improved mechanical properties such as strength, elastic modulus and toughness. Hydroxyapatite/polysulfone laminated composites were fabricated to develop biologically compatible, toughened composites that would match the elastic modulus of bone. Multilayered composites were successfully designed with improved toughness measured by the work of fracture. Toughness measurements were more than an order of magnitude greater than monolithic hydroxyapatite. The toughness and modulus values of hydroxyapatite/polysulfone were within the range of cortical bone.     

低凝重质原油电脱盐影响因素及操作工艺参数分析

针对辽河低凝重质原油具有黏度大、密度高、酸值高、胶质沥青质含量高等特点,根据多年来加工辽河低凝油运行电脱盐设备的生产实践经验,对原油电脱盐的影响因素和操作工艺参数进行分析总结,结果表明:原油密度为911.1~965.9 kg/m3、混合阀适宜压差为30~80 Pa、水溶性破乳剂用量为8~10μg/g、温度为135~140℃、压力控制在0.8~1.2 MPa、注水量取5%(体积分数)、电场强度为700~1000 V/cm、停留时间为2~3 min符合加工辽河低凝原油电脱盐技术标准要求。     

气辅成型中成型工艺对制品翘曲的影响

对气辅成型制品翘曲缺陷采用正交实验方法和数值模拟方法进行了研究。研究了气体注射延迟时间与气体注射压力及气体注射时间与气体注射压力两对工艺参数的交互作用对制品翘曲缺陷的影响。结果表明,对制品翘曲影响最为严重的是气体注射时间与气体注射压力的交互作用。较长的延时可以减轻制品翘曲的程度,但气体无法穿透或穿透不足等问题也是延时过长会造成的,因此选择合适的气体注射时间与气体注射压力以及气体延时组合非常重要。