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141.
介绍了一种基于MSP430F449的掺杂煤炭快速检测仪的设计,阐述了该系统的工作原理和系统设计方案。该系统以DDS芯片AD9833为核心设计激励源,采用24位高精度A/D转换器CS5532实现数据采集,通过RS—232实现上位机和下位机的通信。在煤炭阻抗数据预处理中,采用剔除疏失误差技术,并设计了基于LabVIEW的上位机数据库管理系统。实验证明:该仪器便于携带,低功耗,能够准确识别煤炭的掺杂情况,同时具有操作简单、稳定可靠、方便管理等特点。  相似文献   
142.
为了能更好地掌握运动者的运动力度,尽可能地减小运动中由于运动过剧造成的损伤,设计了一种气动健身器材,通过实际的气缸压力与霍尔传感器检测出气缸活塞的位移来计算器材使用者所承受的拉力,并结合记录气缸活塞的运动次数来计算运动者消耗的热量,更直观地显示出运动者的运动情况。经过测试,霍尔传感器反应灵敏,检测结果准确,系统稳定性良好,有较高的实用性。  相似文献   
143.
Today's news readers can be easily overwhelmed by the numerous news articles online. To cope with information overload, online news media publishes timelines for continuously developing news topics. However, the timeline summary does not show the relationship of storylines, and is not intuitive for readers to comprehend the development of a complex news topic. In this paper, we study a novel problem of exploring the interactions of storylines in a news topic. An interaction of two storylines is signified by informative news events that play a key role in both storylines. Storyline interactions can indicate key phases of a news topic, and reveal the latent connections among various aspects of the story. We address the coherence between news articles which is not considered in traditional similarity-based methods, and discover salient storyline interactions to form a clear, global picture of the news topic. User preference can be naturally integrated into our method to generate query-specific results. Comprehensive experiments on ten news topics show the effectiveness of our method over alternative approaches.  相似文献   
144.
针对学校等大型科研平台拥有的精密器材种类繁多、安置位置分散、操作流程特异、操作人员流动性大的现象,基于监测的思想设计了此仪器管理系统,旨在督促实验人员按稳妥的使用流程操作仪器,并为器材的更迭维修提供参考。系统分为终端、服务端两部分,终端通过检测电流来判断仪器状态,使用者使用需用有效IC卡辨别身份,终端相应给予声光提示,并且拍照留据。相应的状态情况可以通过网络传输到服务器,例如使用者有效卡号、报警照片等且客户端可以从服务端获取人员信息更新等资料。通过对本工程中心内部分仪器的监管测试表明,较好的提高了操作人员使用素质,提高了仪器管理水平。  相似文献   
145.
Sulphur extraction from coal by leaching with bromine-containing aqueous hydrobromic acid has been investigated in the temperature range from ambient to 120 °C. This procedure was found to be selective for the removal of high levels of sulphate and pyritic sulphur within a few minutes of leaching, while no significant reduction of the organic sulphur could be observed. Leaching led to an appreciable reduction of the ash yield and the up-take of substantial quantities of bromine. The bromine can be removed as hydrogen bromide by thermal treatment under nitrogen, without significant loss of volatile matter; for reduction of the bromine level to below 0.1 wt%, treatment for at least 1 h at ≈ 500 °C was needed.  相似文献   
146.
以开滦中润煤化工有限公司焦化厂备煤过程为背景,介绍了备煤控制系统的研究和设计方法。首先基于生产工艺流程,分析焦化过程需要解决的问题以及实现的控制功能。然后构造系统总体框架,包括系统硬件结构、软件实施等。建立CAN总线网络,利用CAN现场总线协议形成开放型的两级计算机控制系统。  相似文献   
147.
煤的荧光特性与其工艺性能的关系研究   总被引:1,自引:0,他引:1  
戴财胜  刘文华 《煤化工》2004,32(2):16-19
简述了煤中镜质组荧光产生的机理及荧光参数的测量方法,通过测定一系列煤的粘结性和10kg小焦炉结焦性试验,探讨了煤的荧光特性与其工艺性能的关系。煤的荧光参数与其反射率呈正的线性相关关系,与其挥发分含量呈负的线性相关关系;煤的粘结性、结焦性均与其荧光参数有关;当煤化程度相同、煤岩组成基本相同时,煤的荧光强度愈强,其结焦性能愈好。  相似文献   
148.
A brown coal, peat and oil shale were subjected to a rapid pyrolysis process and medium-heat-value gases together with tar were collected. The char residue was of high activity and suitable for gasification to create a two-stage gasification system. The coal-tar is used for manufacturing liquid fuels and chemicals.  相似文献   
149.
High temperature, high pressure e.s.r. measurements of the hydrogenation reaction of Taiheiyo coal in the presence of catalysts were carried out to understand the stabilization of thermally and/or catalytically induced free radicals. A decrease in free radical concentration with increasing temperature was observed for ZnCl2 and SnCl2 · 2H2O catalysts at 10MPa under hydrogen gas. High pressure modified single-cell d.t.a. and p.d.a. equipment augmented the uniquely designed high temperature, high pressure e.s.r. cell. The hydrogenation reaction was monitored under the same experimental conditions as for e.s.r. From the results of the combination of high temperature, high pressure e.s.r. with high pressure d.t.a. and p.d.a., it was established that H2 molecules can react efficiently with free radicals from coal molecules created by the presence of ZnCl2 and SnCl2 · 2H2O catalysts.  相似文献   
150.
W. Kemp  W. Steedman  M.A. Thomson  D.A. Scott 《Fuel》1985,64(10):1379-1382
Comparisons have been drawn in the relative reactivities of three coal asphaltenes during hydropyrolysis. All were derived from hydrogen donor-solvent extracts of bituminous coal, but had different hydrotreatment histories and different carbon contents (87.1, 91.9 and 90.8 wt% for asphaltenes 1, 2 and 3, respectively). The hydropyrolyses were carried out in the presence of CoO–MoO3 catalyst and gaseous hydrogen at 8.7 MPa. For two of the asphaltenes (1 and 2) systematic comparisons were made for different reaction times at 425°C; for all three asphaltenes comparisons were made for l h of hydropyrolysis at 425°C. The general pattern of asphaltenes conversion indicated that more pentane-soluble product was produced from asphaltene isolated from straight coal extract (asphaltene 1). For the asphaltenes isolated from hydrotreated extracts, the extent of conversion to liquids was limited when the carbon content was high (asphaltene 2) although the pattern of conversion was similar in the other hydrotreated asphaltene (asphaltene 3). The aliphatic content of the liquid products formed was low, and the distribution of hydrogenated species in the highly aromatic liquid products indicated that complete hydrogenation of the polyaromatics produced in pyrolysis is difficult. Altogether the aliphatics made up ≈ 10 wt% of the asphaltene 1 hydropyrolysate. Aromatic hydrocarbons made up 90% of the liquid product. Phenanthrene, pyrene and anthracene were prominent, and the largest component in the mixture was phenanthrene which, together with other polyaromatics such as fluoroanthene, dominated the liquid product.  相似文献   
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