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101.
李稙  蔡东娜 《图学学报》2019,40(6):1017
花卉植物形态、结构与生长过程的数字化和可视化是现代林业科研的重要研究内 容,数字花卉植物在科普、教育、展示等方面都有着广泛的应用与需求。全息影像技术是一种 新兴的前沿技术,其原理源自佩珀尔幻象,通常用于生成立体感强的影像,实现数字幻象与真 实世界的融合,拥有良好的观赏性,用户接受度较高。将全息影像技术与数字花卉植物相关研 究进行结合,可以加强数字花卉植物的可视化效果,从而实现更好的科普、教育、展示效果。 因此在现有的研究基础之上,考虑实现数字花卉植物的全息可视化,并在可视基础上增加了用 户交互实现,设计出一套兼具展示性和交互性的流程,力求总结出一种具有完整可行性的方案, 从而对数字花卉植物的新型表现形式进行深入研究,以期对数字植物研究与应用的进一步发展 提供参考。  相似文献   
102.
Abstract

Engineers use reliability experiments to determine the factors that drive product reliability, build robust products, and predict reliability under use conditions. This article uses recent testing of a howitzer to illustrate the challenges in designing reliability experiments for complex, repairable systems. We review research in complex system reliability models, failure-time experiments, and experimental design principles. We highlight the need for reliability experiments that account for various intended uses and environments. We leverage lessons learned from current research and propose methods for designing an experiment for a complex, repairable system.  相似文献   
103.
The objective of this study was to investigate the influence of an advanced performance system on the tribological behavior of brake pad material using a specially designed brake pad tester system following standard SAE J-661. The tribological behavior and friction and wear characteristics of the organic brake pad samples were evaluated. During braking tests, the samples, in contact with a cast iron disk, were studied at different disc speeds, temperatures, and braking cycles under a constant pressure. In order to understand the friction and wear behavior, the unworn surfaces, worn surfaces, and wear debris were characterized by means of scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). Furthermore, the surface characteristics and differences in the wear modes of the brake pad samples were examined. Wear debris was permitted to deform the brake pad surfaces, leading to friction layers and enabling the estimation of the friction behavior of the brake pads. The results showed that the best friction–wear behavior was obtained with lower braking cycles at low speeds and temperature. Thus, the newly developed brake pad tester system proved very effective in evaluating the performance of the brake pad samples.  相似文献   
104.
白万里 《冶金分析》2019,39(7):21-28
水分测定是冶金行业中矿产原料和产品分析的重要内容,主要包括交货水分、湿存水、化合水等测定类别。尽管水分测定方法本身相对简单,但其涉及到矿物原料、产品结算交割以及其他化学分析的校正计算,属于重要的基础性测定方法。各类矿物、产品几乎都有相应水分测定的国家标准、行业标准,部分还是从国外ISO标准体系中采标而来。文章系统介绍并比较各类矿物原料、产品中交货水分、明水、湿存水、化合水等类别的测定方法。由于ISO标准体系中湿存水含义和国内标准体系湿存水含义有较大差异,其测定操作和用途也有不同,使用空气平衡样品和密封原始样品将会得到数据差异较大的湿存水数据,两种湿存水含义需要明确区分。湿存水对化学称样量、灼减量、化合水的测定有影响,需要用湿存水进行水分校正,才能得到更精确的结果。  相似文献   
105.
传统的信号联锁系统改造采用室内设备全部更换的方式,投资预算较高。为确保铁路运输安全,维护铁路生产运输秩序,提高信号设备的安全性,同时为减轻现场技术人员管控压力,研究应用新的技术方法,仅对室内信号联锁系统核心设备进行换型升级,室内相关配套设备不做更换,同样能够达到技术改造的效果,满足技术指标需求,同时可以节约大量资金投入。因此,本文针对上述问题开展信号联锁系统核心设备换型升级关键技术研究并在矿区铁路跃进河车站应用,效果显著。  相似文献   
106.
Hydrogen energy utilization is expected due to its environmental and energy efficiencies. However, many issues remain to be solved in the social implementation of hydrogen energy through water electrolysis. This analyzes and compares the energy consumption and GHG emissions of fossil fuel-derived hydrogen and gasoline energy systems over their entire life cycle. The results demonstrate that for similar vehicle weights, the hydrogen energy system consumes 1.8 MJ/km less energy and emits 0.15 kg-CO 2 eq./km fewer GHG emissions than those of the gasoline energy system. Hydrogen derived from fossil fuels may contribute to future energy systems due to its stable energy supply and economic efficiency. Lowering the power source carbon content also improved the environmental and energy efficiencies of hydrogen energy derived from fossil fuels.  相似文献   
107.
Advanced biogas power generation technology has been attracting attentions, which contributes to the waste disposal and the mitigation of greenhouse gas emissions. This work proposes and models a novel biogas-fed hybrid power generation system consisting of solid oxide fuel cell, water gas shift reaction, thermal swing adsorption and proton exchange membrane fuel cell (SOFC-WGS-TSA-PEMFC). The thermodynamic, exergetic, and thermo-economic analyses of this hybrid system for power generation were conducted to comprehensively evaluate its performance. It was found that the novel biogas-fed hybrid system has a gross energy conversion efficiency of 68.63% and exergy efficiency of 65.36%, indicating high efficiency for this kind of hybrid power technology. The market sensitivity analysis showed that the hybrid system also has a low sensitivity to market price fluctuation. Under the current subsidy level for the distributed biogas power plant, the levelized cost of energy can be lowered to 0.02942 $/kWh for a 1 MW scale system. Accordingly, the payback period and annual return on investment can reach 1.4 year and about 20%, respectively. These results reveal that the proposed hybrid system is promising and economically feasible as a distributed power plant, especially for the small power scale (no more than 2 MW).  相似文献   
108.
为了解决长行程定子不连续永磁直线同步电机存在的因无法全程安装位置传感器和不同动子和定子之间的电磁参数不固定所造成的控制性能下降的难题,提出一种在每一段定子内先进行参数标定,再进行速度控制的控制系统设计。首先,在动子进入过程中,对电机进行电磁参数标定,根据标定参数对控制器参数进行调整,以达到更好的控制效果。然后,使用无位置传感器控制系统使动子快速达到设定速度值并稳定运行。实验结果表明:动子进入过程参数标定精度分别为0.002Wb和0.000 4H;无位置传感器控制中位置估计精度为0.63mm,速度收敛时间为0.45s,稳态误差为0.02m/s。基本满足永磁直线同步电机用于长行程运输的控制快速性、稳定性等要求。  相似文献   
109.
针对电子商务顾客购物人工系统的计算实验研究,提出一种基于状态类比假说的人工情绪模型,给出了情绪的产生、增强、衰落和消失过程的描述方法,研究了外部刺激、情感强度和内部驱动力的计算方法,并进行了模拟分析。基于此人工情绪模型,构建了电商顾客购物的情绪-行为影响关系模型;将其应用于电商顾客购物的计算实验分析。结果表明,该人工情绪模型能较好地应用于电商复杂人工系统顾客购物的计算实验。  相似文献   
110.
The recent interest in microbial electrolysis cell (MEC) technology has led the research platform to develop full biological MECs (bioanode-biocathode, FB-MEC). This study focused on biohydrogen production from a biologically catalyzed MEC. A bioanode and a biocathode were initially enriched in a half biological MFC (bioanode-abiocathode, HB-MFC) and a half biological MEC (abioanode-biocathode, HB-MEC), respectively. The FB-MEC was established by transferring the biocathode of the HB-MEC and the bioanode of the HB-MFC to a two-chamber MEC. The FB-MEC was operated under batch (FB-MEC-B) and recirculation batch (FB-MEC-RB) modes of operation in the anodic chamber. The FB-MEC-B reached a maximum current density of 1.5 A/m2 and the FB-MEC-RB reached a maximum current density of 2.5 A/m2 at a similar applied voltage while the abiotic control system showed the maximum of 0.2 A/m2. Hydrogen production rate decreased in the FB-MEC compared to that of the HB-MEC. However, the cathodic hydrogen recovery increased from 42% obtained in the HB-MEC to 56% in the FB-MEC-B and 65% in the FB-MEC-RB, suggesting the efficient oxidation and reduction rates in the FB-MEC compared to the HB-MEC. The onset potential for hydrogen evolution reaction detected by linear sweep voltammetry analysis were −0.780 and −0.860 V vs Ag/AgCl for the FB-MEC-RB and the FB-MEC-B (−1.26 for the abiotic control MEC), respectively. Moreover, the results suggested that the FB-MEC worked more efficiently when the biocathode and the bioanode were enriched initially in half biological systems before transferring to the FB-MEC compared to that of the simultaneously enriched in one system.  相似文献   
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