Cu2(OH)3Cl microspheres with self-assembled nanostructures through a dissolution regulation reaction and exhibits excellent antibacterial activity

Basic copper chloride (Cu₂(OH)₃Cl) microspheres with different surface nanostructure were synthesized via the dissolution regulation of calcite in CuCl₂ solution. We studied the influence of CuCl₂ concentration, reaction time and reaction temperature on the formation of Cu₂(OH)₃Cl, and the products were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy and transmission electron microscopy. The concentration of CuCl₂ has a great influence on the dissolution rate of calcite, dispersed microsphere particles assembled by nano-blocks formed in 20 mM CuCl₂ solution. The surface of Cu₂(OH)₃Cl microsphere change from nano-block to nano-rod with increasing the reaction time from 20 min to 2 h Cu₂(OH)₃Cl microspheres with surface structure changed from nano-sheet, nano-plate to nano-block with the reaction temperature increase from 37 °C to 70 °C. The Cu₂(OH)₃Cl microsphere also displays superior antibacterial properties against S. aureus and E. coli. This work displays a new strategy to synthesize functional materials by the use of dissolution regulation methods.     

典型储电方式的结构特点及碳中和愿景下的发展分析

基于2060年的电力市场数据对未来储电装机容量进行估算,并对抽水蓄能、压缩空气储电和电池储电进行调研,基于其结构、优缺点和性能,分析和预测它们的未来发展趋势,为可再生能源发电份额大幅度增加情况下推广储电技术提供理论依据。在未来较长时期,抽水蓄能电站仍会占储电市场的绝大部分份额;技术升级后的压缩空气储电将会迎来市场爆发,在余热回收利用的地上中小型储电领域得到商业化推广;电池在储电市场的占比将快速增长,退役电池成为未来的重要增长点。综合分析认为,储电市场前景广阔,未来较长时间将会是抽水蓄能平稳增长为主,压缩空气储能和锂电快速增长为辅的局面,从而保证双碳目标的顺利达成。     

海上平台混合直流供电方案研究与仿真分析

  [目的]  海上平台一般均采用海上自供电方案,该供电方式电源形式单一、可拓展性差、抗冲击能力弱、供电可靠性和保障程度低,同时,海上平台的空间非常有限,建设自供电电源投资较高。  [方法]  在对比研究利用岸电交流送电和直流送电方案优缺点的基础上,提出了技术可行、经济性较优的海上平台采用混合直流输电的方案。在此基础上,建立陆地电网侧常规直流、海上平台侧柔性直流的数学模型,结合传统直流的换流器的典型控制方式和柔性直流换流器的典型控制方式,提出混合直流的控制策略。  [结果]  在PSCAD/EMTDC上建立混合柔性直流输电系统的电磁暂态仿真模型,包含近区交流电网、混合直流系统以及海上平台系统的仿真系统模型,并开展建模仿真分析研究,分析近区交流电网、直流系统、海上平台的运行特性、故障特性以及交互影响。  [结论]  研究成果对解决海上平台的安全可靠供电问题具有十分重要意义。     

利用母线CVT响应电流实现变电站雷电侵入波在线监测

介绍了110 kV以上变电站雷电侵入波在线监测的基本原理,以及高频下电容式电压互感器(capacitor voltage transformer,CVT)回路电阻、电感、电容等值参数计算方法并通过仿真模型分析了等值参数计算误差对过电压监测的影响。提出了一种基于CVT响应电流的侵入波在线监测方法,以克服现有研究存在的不足。基于这种监测方法,开发了一种利用变电站母线CVT回路电流实现母线过电压监测的系统,通过该系统可以进行进线段侵入波电流和母线过电压的监测,实现变电站事故监测统计的自动化、智能化和信息化。最后通过电磁暂态程序(alternative transient program,ATP)仿真结果和现场运行中实测波形的对比,说明了监测系统可以持续有效运行。     

光纤布拉格光栅复合绝缘子的应力分布分析

为了最大程度地预防复合绝缘子芯棒脆断等掉串事故,采用在复合绝缘子芯棒中植入光纤布拉格光栅,实现对复合绝缘子芯棒应力的监测,从而判断复合绝缘子的运行状况.绝缘子芯棒在金具压接区部位的结构复杂,所受的应力分布不均匀,故不能直接用光纤光栅的自身应变来表征芯棒内部应变,因此先假设绝缘子芯棒和光纤光栅有相同的应变,对复合绝缘子芯...     

云广与贵广Ⅱ回直流输电系统共用接地极设计

为了不对系统运行产生太大影响并节省工程用地和建造费用,云广特高压直流输电工程和贵广Ⅱ回高压直流输电工程广东侧考虑采用共用接地极模式建造。根据系统运行条件、使用寿命以及人身安全的要求确定了建设共用接地极的参数,对该参数采用了矩量法和边界元法相结合的接地计算数值方法,并针对大罗州和李屋两个极址分别设计了一套共用接地极方案。这两套设计方案既能满足系统要求又能符合国家标准,不会对人身安全产生影响,可供建设共用接地极使用。     

基于CEEMD和NTEO的故障行波定位方法

针对传统行波检测方法中定位不准确、计算量大等问题,提出了一种基于补充总体平均模态分解(complementaryensembleempiricalmodedecomposition, CEEMD)和改进型Teager能量算子(novelTeagerenergy operator,NTEO)的行波定位方法。该方法采用CEEMD算法来分解故障行波信号,滤除故障信号中的低频分量。然后采用NTEO能量算子对分解后的信号进行差分运算,增强行波波头的突变特征,实现故障行波波头的精确标定。仿真结果表明,所提方法能够精准地标定故障行波波头,并且有良好的去噪能力。与传统方法相比具有更好的检测效果和更小的定位误差,可以有效地提高配电网行波定位的精确性。     

Induction machine models for practical use in simulation of transients in power station auxiliaries

Two induction machine models are presented which take the rotor bar skin effect into account by means of lumped parameter circuits.The induction machine models are based on the two-axis theory using the rotor reference frame. A set of first-order differential equations suitable for digital simulation are shown for each model. The parameters of the lumped circuits, representing the rotor parts of the induction machine, are obtained by an iterative solution of derived equations based only on the normally known values of rotor resistances and rotor leakage inductances.     

Influence of Fe2O3 on the hydration kinetics of tricalcium aluminate

The influence of Fe₂O₃ on the hydration kinetics of tricalcium aluminate (C₃A) was studied in order to clarify the mechanism of improving hydration resistance of CaO by in-situ synthesized tricalcium aluminate. The Krstulovic-Dabic model was used to investigate the hydration processes of Fe₂O₃-C₃A solid solution and calculate the corresponding kinetic parameters. The hydration products were analyzed by the X-ray diffraction and scanning electron microscope. The results indicated that the Krstulovic-Dabic model simulated the hydration processes of Fe₂O₃-C₃A solid solution at different stages effectively. The hydraulic activity of Fe₂O₃-C₃A solid solution decreased with the addition of Fe₂O₃. Reasonable amount of Fe₂O₃ addition reduced the hydration rate in the initial stage of Fe₂O₃-C₃A solid solution hydration, while the hydration rate of Fe₂O₃-C₃A solid solution was increased with excessive amount Fe₂O₃. The hydration process was controlled by multiple mechanisms due to an incomplete layer of hydration products was formed on the surface.     

Mechanism of superior charge suppression behavior of Si3N4 ceramics at solid-gas interface

Recent study has found excellent bulk and surface insulation property of Si₃N₄ ceramic which make it potential to serve as key insulation component in various energy transmission apparatus. Charge accumulation at gas-solid interface is a critical insulation property but few relevant study on Si₃N₄ can be found. This contribution has investigated the surface charge property of Si₃N₄ ceramic compared to traditional insulation polymer under different electrical-thermal stress. Through its comparison with the electric field distribution, the main source of the surface charge accumulation is analyzed, indicating that the superior surface charge suppression performance of Si₃N₄ lies on its low carrier density and conduction barrier, which considerably prevent charge injection and suppress the normal electric field which drives the charge to the gas-solid interface. The proposed mechanism is also validated by the characterization on conducting and space charge property for Si₃N₄ as well as dynamic simulation on surface charge accumulation.