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31.
为更有针对性地进行故障排除工作,文章设计研发了一款多媒体软件平台,嵌入细化后的DZZ5型自动气象站各观测要素的故障排查流程,并在相应故障检测节点中添加文字、图片和操作视频。用户可按照流程逐一进行排查操作,或者搜索关键字查看节点内容。同时提供带有关键字查询功能的故障实例库,供基层装备保障业务人员参考。 相似文献
32.
《Ceramics International》2020,46(12):20038-20044
Double perovskite La2MnNiO6 nanoparticles (approximately 30 nm in diameter) were synthesized using a modified sol-gel method followed by a firing process and used as promising electrode materials for oxygen evolution reactions (OERs). The phase purity of the nanoparticles was verified using X-ray diffraction and Raman spectroscopy measurements. La2MnNiO6 nanoparticles crystallize in a monoclinic structure (P21/n space group) with refined lattice parameters of a = 5.461(5) Å, b = 5.512(3) Å, c = 7.760(5) Å, and β = 90.10(2)°. The elemental composition, particle size, size distribution, and surface area of the La2MnNiO6 nanoparticles were also investigated. La2MnNiO6 nanoparticles are ferromagnetic in nature and exhibit hysteresis with a saturation magnetization value of approximately 9 emu/g. La2MnNiO6 nanoparticles exhibit highly efficient electro-catalytic activity for OERs with a low onset over-potential (approximately 65 mV) and low Tafel slope values (120 mV/dec) in alkaline media. The over-potential of La2MnNiO6 nanoparticles at a current density of 10 mA/cm2 is in good agreement with the reported over-potential (ƞ10) of double perovskites, commercial Pt/C and IrO2 electro-catalysts for promoting OERs. 相似文献
33.
A double optimal projection method that involves projections for intra-cluster and inter-cluster dimensionality reduction are proposed for video fingerprinting. The video is initially set as a graph with frames as its vertices in a high-dimensional space. A similarity measure that can compute the weights of the edges is then proposed. Subsequently, the video frames are partitioned into different clusters based on the graph model. Double optimal projection is used to explore the optimal mapping points in a low-dimensional space to reduce the video dimensions. The statistics and geometrical fingerprints are generated to determine whether a query video is copied from one of the videos in the database. During matching, the video can be roughly matched by utilizing the statistics fingerprint. Further matching is thereafter performed in the corresponding group using geometrical fingerprints. Experimental results show the good performance of the proposed video fingerprinting method in robustness and discrimination. 相似文献
34.
随着5G移动通信频段的公布,传统基站天线已不足以覆盖其工作频段。文章以紧耦合阵列天线理论为基础,提出了一种基于紧耦合结构的交叉偶极子宽带基站天线。该天线由两对正交的领结状偶极子天线构成,通过两对交叉偶极子之间的耦合效应,有效地展宽了天线的阻抗带宽。同时,通过在天线和金属反射板之间加载电阻型频率选择表面,吸收由反射板引入的谐振反射波,改善天线高频端辐射性能。仿真及测试结果表明:该天线在1.7-3.6 GHz 频率范围内,可以满足基站天线的设计指标,两端口驻波比均小于1.5,两端口之间隔离度大于55 dB,半功率波束宽度满足65°±5°范围,且整个频段内增益均大于8.5 dBi。 相似文献
35.
在全国天然气管道“主干互联、区域成网”(以下简称“互联互通”)基础格局逐渐形成的背景下,天然气管网规模日益扩大、管道分支和气源增加,并且分布不集中、输送方向可变,使得输气方案更加灵活,可以更好地解决某些地域的供气紧张问题;但受现有站场和设备的限制,暂不能满足某些多线组合极限工况,使得“互联互通”的初衷难以全部实现。为了使得现有的各输气干线在实现“互联互通”之后可以满足更多的多线组合工况,在分析“互联互通”背景下M管网工况变化的基础上,研发了可以进行水力仿真和压气站方案制订的计算软件,并对3种极限工况下的不同输气量情况进行了可行性试算,进而基于试算结果提出了相应的管网改进建议。研究结果表明:(1)经验证,软件计算误差满足要求;(2)在M管道某处增设压气站或在某些输气站场配置压缩机组;(3) M管网改进调整后,可以完成大部分的多线组合极限工况,真正实现“互联互通”的输气方案。结论认为,该研究成果有助于推进全国天然气管网早日实现“互联互通”。 相似文献
36.
37.
近年来,我市因雷击而导致搅拌站系统瘫痪停产、影响工程进度的事件时有发生,在针对混凝土搅拌站配料秤的实际检定工作中,也常发现配料秤的称重传感器因雷击损坏而影响计量准确性。因此,对混凝土搅拌站防雷的研究具有重要意义。本文阐述了雷电对混凝土搅拌站的主要危害,分析了混凝土搅拌站常见的雷击原因及其防护措施,旨在引起生产方、安装方以及使用方对混凝土搅拌站防雷的共同重视。 相似文献
38.
The scheduling process of cracking furnace feedstock is important in an ethylene plant. In this paper it is described as a constraint optimization problem. The constraints consist of the cycle of operation, maximum tube metal temperature, process time of each feedstock, and flow rate. A modified group search optimizer is pro-posed to deal with the optimization problem. Double fitness values are defined for every group. First, the factor of penalty function should be changed adaptively by the ratio of feasible and general solutions. Second, the“excel-lent”infeasible solution should be retained to guide the search. Some benchmark functions are used to evaluate the new algorithm. Final y, the proposed algorithm is used to optimize the scheduling process of cracking furnace feedstock. And the optimizing result is obtained. 相似文献
39.
高水头大型抽水蓄能电站输水系统的充水和排水,是电站投入运行不可缺少的一项安全检验,初期充排水试验是加载、卸载、检查、监测、发现问题和处理缺陷的过程,为今后电站正式运行提供安全可靠的质量保证。本文详细介绍了辽宁蒲石河抽水蓄能电站输水系统充排水试验方法,可供类似工程参考。 相似文献
40.
This paper deals with three-dimensional non-linear finite element analyses to assess the structural behavior of adhesively-bonded double supported tee joint of laminated FRP composites having embedded interfacial failures. The onset of interfacial failures is predicted by using Tsai–Wu coupled stress failure criterion with pre-determined stress values. The concept of fracture mechanics principle is utilized to study the sustainability of the tee joint having interfacial failures pre-existed at the critical locations. Individual modes of the strain energy release rates (SERR) GI, GII and GIII, are considered as the damage growth parameters and, are evaluated using the Modified crack closure integral (MCCI) technique based on the concept of linear elastic fracture mechanics (LEFM). Based on the stress analyses, it has been observed that the interfacial failures in tee joint structure trigger at the interface of base plate and adhesive layer from both ends of base plate. Depending on the SERR magnitudes, it has been noticed that the interfacial failure propagates under mixed mode condition. Therefore total SERR (GT) is considered as the governing parameter for damage propagation. Furthermore, efforts have been made to retard damage propagation rate by employing functionally graded adhesive (FGA) instead of monolithic adhesive material. Series of numerical simulations have been performed for varied interfacial failure length in functionally graded adhesively bonded double supported tee joint structure in order to achieve the significant effect of FGA with various modulus ratios on SERR. Material gradation of adhesive indicates significant SERR reduction at the incipient stage of failure which necessitates the use of functionally graded adhesive for the tee joint and prolong the service life of the structure. 相似文献