混凝-粉末活性炭吸附-超滤工艺去除砂滤池反洗水溶解性有机物

通过混凝-粉末活性炭(PAC)吸附-浸没式超滤膜(UF)组合工艺去除砂滤池反洗水(FBWW)中溶解性有机物(DOM),以降低后续回用过程中消毒副产物(DBPs)生成量。试验对3种混凝药剂——聚合硫酸铁(PFS)、三氯化铁(FeCl3)、聚合氯化铝(PACl)处理FBWW的效果进行了比较,探讨其对UV254和水溶性有机物(DOC)的去除效果。结果表明,PFS对有机物去除效果优于PACl和FeCl3;PFS与粉末活性炭混合投加可增加有机物去除率,粉末活性炭为20mg/L,PFS为8mg/L时出水浊度为0.85NTU,UV254和DOC去除率分别为43%和31%;采用混凝-PAC吸附-超滤膜(UF)处理FBWW对UV254和DOC去除率分别达到51%和41%,出水浊度为0.19NTU,UV254为0.031cm-1,DOC为2.76mg/L.此工艺可有效降低反冲洗水中DOM含量,达到重新利用净水厂废水的目标.     

重庆彩电中心变电站原址带电整体改造

介绍在重庆彩电中心变电站有限的空间范围内,原址带电整体改造,包括项目改造背景、方案选择、工艺负荷供电模式、改造内容和工程施工方法等。     

液压支架电液控制系统设计

根据液压支架电液控制系统在国内外的应用现状,介绍了综采工作面液压支架电液控制系统的组成和功能,并自主设计了液压支架控制器、采煤机位置检测系统、巷道主机和本质安全型网络。实际的推广应用表明液压支架电液控制系统可实现液压支架就地控制、远程监控及其配套设备跟机自动控制。     

高端液压支架关键技术研究与产业化进展

介绍高端液压支架技术发展背景,提出基于液压支架与围岩耦合的三维动态优化设计方法,通过对高强度焊接结构钢、支架结构件残余应力分析、焊接机器人、电液控制系统和大缸径抗冲击立柱等关键制造技术的综合研究与应用,推进了高端液压支架产业化发展;最后总结了系列高端液压支架研制和产业化实施效果,如成功研制的ZY1700/32/70D、ZF150000/28/56等高端液压支架,寿命达到50 000次工作循环。     

砚北煤矿厚煤层综放面液压支架选型与应用

通过对砚北煤矿2502采区开采过程中矿山压力显现情况的分析和计算,确定了1504采区综放工作面液压支架的工作阻力,并结合工作面掘进过程中的矿压显现情况,选择了能够满足现场实际需求的支架类别和结构形式。现工作面已推采1 200余m,在几次矿压显现中,震动能量达3.66×106 J,工作面支架和两巷道的超前支架均能满足可靠支护要求。     

QY200/14/31型液压支架关键部件有限元分析

在建立QY200/14/31型液压支架的三维模型基础上,采用虚拟样机技术和有限元分析相结合的方法,分析液压支架在额定载荷作用下关键部件受力特性。将三维模型导入动力学分析软件中,以获取关键部件铰接处作用力的变化规律,然后提取3个极限位置的模型进行有限元分析并比较位移/应力分布的特点。结果表明:液压支架从最小高度上升到最大高度处,柱窝处的作用力和整架刚度先减小后增加;最小高度处关键部件应力值较大,中间高度处居中,而最大高度处最小,说明该支架支撑高度离最大高度越接近,承载能力越强。     

新型机械加长杆立柱的设计

为了更加科学地发挥液压支架中加长杆立柱的使用性能,通过对传统液压支架加长杆立柱的结构及受力优缺点进行分析研究,结合实际及其他领域设计经验,设计出一种新型的液压支架用机械加长杆立柱(已申请专利)。通过对2种结构的加长杆立柱进行结构及受力比较试验,试验结果表明该新型结构的机械加长杆立柱要优于传统结构加长杆立柱,有很好的应用前景。     

Membrane‐Based Self‐Powered Triboelectric Sensors for Pressure Change Detection and Its Uses in Security Surveillance and Healthcare Monitoring

A new membrane‐based triboelectric sensor (M‐TES) is presented as a self‐powered pressure change sensor. It generates a voltage induced by surface triboelectric charges in response to an air pressure change. Extremely high detection resolutions of 0.34 Pa and 0.16 Pa are achieved when the air pressure increases and decreases in a small region away from the ambient standard atmosphere pressure, respectively, indicating an excellent sensitivity. By integrating the M‐TES with a signal processing unit, we demonstrate practical applications of the device in sensing footsteps, respirations, and heartbeat, which suggests widespread use of the M‐TES in fields of security surveillance, chemical engineering, geography research, environment monitoring, and personal healthcare.     

Triboelectric Nanogenerator as an Active UV Photodetector

Self‐powered nanosensors and nanosystems have attracted significant attention in the past decades and have gradually become the most desirable and promising prototype for environmental protection/detection because no battery is needed to power the device. Therefore, in this paper a design is proposed for a self‐powered photodetector based on triboelectric nanogenerator (TENG) configuration. 3D dendritic TiO₂ nanostructures are synthesized as the built‐in UV photodetector as well as the contact material of the TENG. The cost‐effective, robust, and easily fabricated TENG‐based photodetector presents superior photoresponse characteristics, which include an excellent responsivity over 280 A W^?1, rapid rise time (18 ms) and decay time (31 ms), and a wide detection range of light intensity from 20 μW cm^?2 to 7 mW cm^?2. In the last part of the paper, a stand‐alone and self‐powered environmental sensing device is developed by applying poly(methyl methacrylate) (PMMA) substrates and springs to assemble the TENG‐based photodetector. These results indicate that the new prototype sensing device based on the TENG configuration shows great potential as a self‐powered photodetector.     

Direct‐Current Triboelectric Generator

The first direct‐current triboelectric generator (DC‐TEG) based on sliding electrification for harvesting mechanical energy from rotational motion is reported. The DC‐TEG consists of two rotating wheels and one belt for connecting them, which are made of distinctly different triboelectric materials with a specific requirement. During the rotation, the contact‐induced electrification and the relative sliding between the two wheels and the belt can induce a continuous increase of the accumulated positive and negative triboelectric charges at the two rotating wheels, respectively, resulting in a Corona discharge and producing the observed current through an external load. The DC‐TEG can deliver an open‐circuit voltage of larger than 3200 V and a maximum power of 100 μW under an external load of 60 MΩ at a rotational speed of 1000 r min^–1. By designing a point metal discharge electrode near the accumulated positive charges on the metal wheel, the instantaneous short‐circuit current can be up to 0.37 mA. The DC‐TEG can be utilized as a direct power source to light up 1020 serially connected commercial light‐emitting diodes (LEDs) and the produced energy can also be stored in a capacitor for other uses. This work presents a DC‐TEG technology to harvest mechanical energy from rotational motion for self‐powered electronics.