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1.
Wenshu Chen Jiajun Gu Yongping Du Fang Song Fanxing Bu Jinghan Li Yang Yuan Ruichun Luo Qinglei Liu Di Zhang 《Advanced functional materials》2020,30(25)
Large‐scale production of hydrogen from water‐alkali electrolyzers is impeded by the sluggish kinetics of hydrogen evolution reaction (HER) electrocatalysts. The hybridization of an acid‐active HER catalyst with a cocatalyst at the nanoscale helps boost HER kinetics in alkaline media. Here, it is demonstrated that 1T–MoS2 nanosheet edges (instead of basal planes) decorated by metal hydroxides form highly active / heterostructures, which significantly enhance HER performance in alkaline media. Featured with rich / sites, the fabricated 1T–MoS2 QS/Ni(OH)2 hybrid (quantum sized 1T–MoS2 sheets decorated with Ni(OH)2 via interface engineering) only requires overpotentials of 57 and 112 mV to drive HER current densities of 10 and 100 mA cm?2, respectively, and has a low Tafel slope of 30 mV dec?1 in 1 m KOH. So far, this is the best performance for MoS2‐based electrocatalysts and the 1T–MoS2 QS/Ni(OH)2 hybrid is among the best‐performing non‐Pt alkaline HER electrocatalysts known. The HER process is durable for 100 h at current densities up to 500 mA cm?2. This work not only provides an active, cost‐effective, and robust alkaline HER electrocatalyst, but also demonstrates a design strategy for preparing high‐performance catalysts based on edge‐rich 2D quantum sheets for other catalytic reactions. 相似文献
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面对电信承载网连接的日益增长的海量终端设备,运营商需要结合网络拓扑对终端设备产生的数据进行高效的汇聚统计、异常分析、故障定位处理等操作。针对已有系统存在的操作困难、分析效率低等问题,设计与实现了一个面向电信承载网的高效监控系统,提供实时与离线数据分析和多维可视化分析的能力。对网管、认证、终端等系统及设备采集的数据进行结构化存储,对采集的数据进行拓扑相关性和时间序列方法分析,根据分析结果实现基于动态阈值控制的异常实时告警、定位等操作,并提供多维度可视化分析对网络状态进行实时监控。实际应用结果表明,该系统性能优异,具有良好交互性,能较好地满足承载网运维人员业务分析需求。 相似文献
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Chen Tang Tiehu Li Yuhang Bai Junjie Gao Wenbo Yang Shasha Jiao Tingkai Zhao 《Ceramics International》2018,44(10):11812-11819
Recently, ceramic matrix composites reinforced by short carbon fibers (CFs) attracted increasing attentions. To further improve mechanical properties and oxidation resistances, CFs were subjected to oxidation and acidification followed by sol-gel dip-coating to deposit ZrO2 on their surfaces. ZrO2-Cf/SiC composites were fabricated by joint hot compression molding and sintering, compared to Cf/SiC and SiC prepared by the same method. Microstructural analyses indicated that ZrO2 coatings were successfully deposited on CF surfaces, formed strong bonding and interfaces between CF and the matrix. Meanwhile, CFs were found uniformly distributed in SiC matrix with random orientations. Flexural curves of ZrO2-Cf/SiC and Cf/SiC revealed the presence of “false plasticity” regions after sharp drops, which were quite different from brittle flexural behavior of SiC ceramic. Compression strength of the three samples showed step-up growth. ZrO2-Cf/SiC exhibited the highest value, indicating the introduction of CFs and ZrO2 coatings do have great influence on mechanical performances. After heat treatment, ZrO2-Cf/SiC exhibited better oxidation resistance than Cf/SiC, with weight loss ratios estimated to ??3.76% and ??6.43%, respectively. These improved properties indicated that ZrO2-Cf/SiC would be excellent alternatives to other existence materials under ultra-high temperature environments. 相似文献
5.
Shuaishuai Ding Yuan Tian Xiang Liu Ye Zou Huanli Dong Wenbo Mi Wenping Hu 《Nano Research》2021,14(1):304-310
The spinterface formed between ferromagnetic(FM)electrode and organic materials is vital for performance optimization in organic spin valve(OSV).Half-metallic Fe3O4with drastic change in structure,conductivity and magnetic property near Verwey transition can serve as an intrinsic spinterface regulator.However,such modulating effect of Fe3O4in OSV has not been comprehensively investigated,especially below the Verwey transition temperature(Tv).Here,we highlight the important role of Fe3O4electrode in reliable-working and controllable Fe3O4/P3HT/Co polymer spin valves by investigating the magnetoresistance(MR)above and below 7V.In order to distinguish between different contributions to charge transport and related MR responses,the systematic electronic and magnetic characterizations were carried out in full temperature range.Particularly,the first-order metal-insulator transition in Fe3O4has a dramatic effect on the MR enhancement of polymer spin valves at 7V.Moreover,both the conducting mode transformation and MR line shape modulation could be accomplished across 7V.This research renders unique scenario to multimodal storage by external thermodynamic parameters,and further reveals the importance of spin-dependent interfacial modification in polymer spin valves. 相似文献
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油气管道完整性评价与管理软件 总被引:5,自引:0,他引:5
作为保障油气管道安全运行的重大举措,管道的完整性管理已经受到了国内外油气管道业界的高度重视,并处在不断地推广应用之中。为方便管道完整性管理技术的实际应用,研制开发了适用于工程实用目的的油气管道完整性评价与管理软件(PIAMS), 并包含了管道风险评价与剩余强度评价的功能模块。为此,介绍了该软件的结构、模块、特点、主要功能和用户界面;该软件由数据库、管道风险分析、腐蚀缺陷评价、用户管理4个模块组成;可以运用该软件管理油气管道的完整性数据信息,进行管道的风险计算、风险分析以及对含缺陷管道的剩余强度评价;此外,该软件还具有可扩展性强的特点。 相似文献
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火焰喷涂是激光熔覆前合金粉末的预置方法之一。本文在实验的基础上,探讨了工艺过程,并讨论了影响质量的因素。 相似文献