A power management circuit with 50% efficiency and large load capacity for triboelectric nanogenerator

Recently, triboelectric nanogenerators (TENGs), as a collection technology with characteristics of high reliability, high energy density and low cost, has attracted more and more attention. However, the energy coming from TENGs needs to be stored in a storage unit effectively due to its unstable ac output. The traditional energy storage circuit has an extremely low energy storage efficiency for TENGs because of their high internal impedance. This paper presents a new power management circuit used to optimize the energy using efficiency of TENGs, and realize large load capacity. The power management circuit mainly includes rectification storage circuit and DC-DC management circuit. A rotating TENG with maximal energy output of 106 mW at 170 rpm based on PCB is used for the experimental verification. Experimental results show that the power energy transforming to the storage capacitor reach up to 53 mW and the energy using efficiency is calculated as 50%. When different loading resistances range from 0.82 to 34.5 kΩ are connected to the storage capacitor in parallel, the power energy stored in the storage capacitor is all about 52.5 mW. Getting through the circuit, the power energy coming from the TENGs can be used to drive numerous conventional electronics, such as wearable watches.     

节能型散热器选型分析

本文对目前建筑市场销售的不同材质节能型散热器如何选用进行分析,推荐用热媒流量携带的热量进入散热器散出的热量(散热强度W/kg·h)来评价节能型散热器。对于同一类型(如辐射型)散热器均可用热媒流量散热强度相互比较。并对散热器表面涂料对散热器效率的影响提出了看法。     

杭州湾跨海大桥50m箱梁C50海工耐久混凝土配合比试验研究

海工耐久混凝土的应用在国内尚属起步阶段,本文针对杭州湾跨海大桥50m箱梁海工耐久混凝土的具体要求及特点,就海工耐久混凝土原材料选择、配合比设计和工艺试验进行了介绍,总结了箱梁海工耐久混凝土的配制要点。     

深层地下连续墙施工护壁泥浆的系统分析与控制程序设计

系统论述了护壁泥浆的性能，并对其指标的确定、配合比设计及泥浆用量的计算、泥浆质量的控制、废弃泥浆的处理等问题进行了探讨。     

常用旋转薄壳通用计算模式

本文是根据弹性薄壳理论,对部分应用非常广泛的旋转壳,通过它们内在的联系导出以超几何函数作为统一计算模式,使复杂的壳体分析(多种函数表达)规范化,便于掌握和运用.文中较多地涉及超几何方程在极限状态时的新方程解,故从应用角度称它们为“退化超几何方程”及“退化超几何函数”解.     

安钢焦化厂节水途径探索与实践

对焦化厂水耗高的状况进行分析,介绍了焦化厂运用技术、设备、管理等方法,进行的节水措施改造,探讨焦化厂节水新途径。     

A numerical approach for planning offshore wind farms from regional to local scales over the Mediterranean

Renewable energy resources, such as wind, are available worldwide. Locating areas with high and continual wind sources are crucial in pre-planning of wind farms. Vast offshore areas are characterized by higher and more reliable wind resources in comparison with continental areas. However, offshore wind energy production is in a quite preliminary phase. Elaborating the potential productivity of wind farms over such areas is challenging due to sparse in situ observations. The Mediterranean basin is not an exception. In this study we are proposing numerical simulations of near-surface wind fields from regional climate models (RCMs) in order to obtain and fill the gaps in observations over the Mediterranean basin. Four simulations produced with two regional climate models are examined here. Remote sensing observations (QuikSCAT satellite) are used to assess the skill of the simulated fields. A technique for estimating the potential energy from the wind fields over the region is introduced. The wind energy potential atlas and the map of a wind turbine's functional range are presented, locating the potentially interesting sub-regions for wind farms. The ability of models to reproduce the annual cycle and the probability density function of wind speed anomalies are detailed for specified sub-regions.     

修订电风扇用电动机技术条件标准的一点体会

本文通过《电风扇电动机通用技术条件》标准的修订工作,阐述了部件产品技术条件制修订工作的体会,既要考虑部件产品的特点,又要考虑整机产品的要求。     

精炼渣改性后的成块和熔化性能测试

将作为固体废弃物的精炼渣,经过适当地调整成分,造块后返回转炉炼钢冶炼过程,可以实现精炼渣少排放或零排放.本试验通过正交试验对精炼渣和改性后的合成渣的抗压性能、熔化性能进行了测试.试验结果表明,合成渣的成块性能和熔化性能可以满足转炉炼钢的要求.     

矿用空气幕隔断风流理论模型及其应用研究

利用流体力学、有效压力理论、通风理论以及能量守恒定律等,对矿用单机、多级串并联空气幕隔断风流理论模型进行了研究,并按照多级并联空气幕隔断风流替代风门这一理论模型,选择了车辆和行人频繁且风门难以发挥作用的地段进行了实际应用研究,并取得了成功。