大学校园安全的技防与人防

论文结合现有文献分析了大学校园存在周边环境复杂、学生安全意识薄弱、未能落实安防制度和安全责任、安全设备运用不足等问题,提出大学校园的安全工作应遵循人防与技防相结合的原则,建议通过安全人防的岗位责任制、培训机制、安保部门和公安机关联动机制、奖励机制,以及技防的安防设备配置全面规划、意外安全事故风险防范、安防设备和技术的自主创新等方式,来改善大学校园的安全水平。     

Microbial fuel cells: Advances in electrode modifications for improvement of system performance

There is an increasing trend to conduct the researches related to Microbial Fuel Cells (MFCs) in the recent years. Limited power output has been the major obstacle for the practical application and upscaling of MFCs. Attempts have been made on electrode modifications such as anode treatments, cathode modifications with catalysts and bio cathodes developments to produce varying degrees of improved output current depending upon the types of modifications. Power density and Coulombic efficiency have been considered as the important parameters to analyze the system performances. This paper overviews on the advances made in MFCs’ researches focusing on different types of electrodes modifications along with the involved methodology. Furthermore, the system performances of different modified MFCs are compared in terms of the power density and the Coulombic efficiency.     

Stand-alone wind power system with battery/supercapacitor hybrid energy storage

This paper presents a stand-alone wind power system with battery/supercapacitor hybrid energy storage. A stand-alone wind power system mainly consists of a wind turbine, a permanent magnet synchronous generator, hybrid energy storage devices based on a vanadium redox flow battery and a supercapacitor, an AC/DC converter, two bidirectional DC/DC converters, a DC/AC converter and a variable load. Several control strategies for the stand-alone wind power system are involved such as a maximum power point tracking (MPPT) control, a vanadium redox flow battery charge/discharge control and a supercapacitor charge/discharge control. The proposed MPPT control combines a sliding mode control with an extreme search control to capture maximum wind energy. This strategy avoids the necessity of measuring wind velocity, obtaining models or parameters of the wind turbine and calculating the differentials of the power generated from the wind power system and from the speed of the generator. The battery charge/discharge control maintains a constant DC bus voltage. When the battery charging/discharging current reaches the setting threshold, the charge/discharge control of the supercapacitor is triggered to limit the charging/discharging current of the battery. The simulation results show that the proposed method can rapidly respond to variations in wind velocity and load power.     

燃煤电厂超低排放气态污染物监测技术综述

介绍了燃煤电厂超低排放气态污染物监测系统的采样系统和分析单元,分析了其各自的优缺点。对稀释抽取式、冷干抽取式和热湿抽取式3种采样方法,以及非分散红外吸收法(NDIR)、非分散紫外吸收法(NDUV)、紫外差分吸收法(DOAS)、紫外荧光法(UVF)和化学发光法(CL)5种分析方法进行对比。结果表明,冷干抽取式+紫外差分法以及稀释抽取式+紫外荧光法+化学发光法可以较好地符合燃煤电厂超低排放监测的要求。     

Economic dispatch of power system containing wind power and photovoltaic considering carbon trading and spare capacity variation

The drying up of the fossil energy sources and the damage from unchecked carbon emissions demand the development of low carbon economy, which promotes the development of new energy sources, such as wind power and photovoltaic. However, the direct connections of wind/photovoltaic power into power grid bring great impacts on power systems, thus affecting the security and stability of power system operations, which challenges the power system dispatching. In despite of many methods for power system dispatch, lack of the models, for power system containing wind power and photovoltaic considering carbon trading and spare capacity variation (PSCWPCCTSCV), restricts the further optimal operations of power systems. This paper studies the economic dispatch modeling problem of power system containing wind power and photovoltaic, establishes the model of economic dispatch of PSCWPCCTSCV. On this basis, adaptive immune genetic algorithm is applied to conduct the economic operation optimization, which can provide the optimal carbon trading price and the optimal power distribution coefficient. Finally, simulations based on the newly proposed models are made to illustrate the economic dispatch of PSCWPCCTSCV. The results show that optimization with the proposed model can not only weaken the volatility of the new energy effectively, but also reduce carbon emissions and reduce power generation costs.     

Communicating risk for vulnerable groups: a case study of the Mano community’s strategies for collective knowledge to action

This paper discusses the emergent interest in risk communication as a strategy for disaster risk reduction. Communication plays an essential role in understanding risk, but studies suggest that people often do not respond in the way that risk experts anticipate. For risk communication to be effective, vulnerable communities need to understand risk within the local context as well as in terms of sustainability. Risk messages offer communities a way to enhance their collective knowledge of existing vulnerabilities, leading them towards alternative solutions for action. A longitudinal study of the Mano community development approach and its recovery from the 1995 Kobe earthquake illustrates how risk communication dynamics contributed to the community’s sustainable risk reduction. The study concludes that risk communication is a collaborative way for a community to work with risk experts, own their risk information, influence existing policies and practices, develop solutions to reduce vulnerability, and ultimately enhance a community’s capacity for managing future risk.     

Efficiency enhancement in solar air heaters by modification of absorber plate-a review

This paper outlines a complete review on modifications made on the absorber plate of solar air heaters in order to improve the turbulence and heat transfer rate, thereby efficiency. Corrugated sheets, fins, extended surfaces, wire mesh, porous medium, etc., are a few of the modifications used. Most of such alterations in the absorber plate resulted with an increase in efficiency but associated with drawback of increased pumping power due to raising friction factor. Pumping power is considered here as a predominant comparison parameters of various solar air heaters with different absorber plate in terms of effective efficiency.     

Green energy generation by pressure retarded osmosis: State of the art and technical advancement—review

Pressure-retarded osmosis (PRO) is a method for converting salinity gradients to power by allowing water to flow through a semi-permeable membrane against an applied hydraulic pressure. PRO already has a long history, starting from the middle of the last century, and has rapidly improved in recent years. In this paper, we present a historical development of PRO since its inception: the development of this renewable energy process has gone through several stages, depending on technological developments, worldwide energy demands, and environmental concerns. The technological progress of the process is also studied, as well as its cost viability and environmental impact. Finally, some ideas to further develop the PRO process and mitigate its detrimental effects are discussed.     

电网发展、清洁电源接入与地区能源效率

鉴于我国已经建成全球规模最大的超高压和特高压电网,彻底弥补了电力跨区配置的电网基础设施短板,并且为清洁电源并入电网和跨区消纳提供了完善的基础设施,不仅克服我国电力负荷中心和能源基地的区域布局不协调,而且有益于缓解日益严峻的能源利用率低下和环境污染问题。本文利用1991—2012年全国29个省市面板数据实证研究了清洁电源并网对地区全要素能源效率的影响。为保证实证结果稳健性分别在线性和非线性实证框架下采用系统广义矩估计(SYS-GMM)和面板平滑转换模型(PSTR)两种方法估计了清洁电源接入高压、超高压和特高压电网的地区全要素能源效率异质性效应。实证结果显示:(1)我国电网基础设施对地区全要素能源效率具有明显的增进效应,特别是超高压电网在促进全要素能源效率提升上表现的最为突出,在特高压骨干网架尚未形成的情况下起到了支柱性作用。(2)高压、超高压、特高压与清洁电源交互项的估计系数始终位于负数区间,反映清洁电源并网的能源效率绩效并不明显,受限于并网规模和机制缺陷,还没有发挥出全要素能源效率提升作用。(3)随着人均GDP的不断提高,各等级电网对地区能源效率的益处越来越明显,并且存在着门槛效应。(4)特高压电网对地区能源效率的积极作用主要表现在东部沿海高收入省份,这些省份作为电力消费负荷中心,大规模接入清洁电源对能源效率改善裨益明显。接下来,需要根据地区的能源禀赋结构选择清洁电源的并网模式,完善的电网基础设施、合理的电源结构还需要配置以高效的清洁电源并网机制才能不断增进地区全要素能源效率。     

燃煤电厂在线监测系统颗粒物浓度排放系数影响因素的探讨

选取上海市7家未安装气-气换热器的国控燃煤电厂作为研究对象，从煤质、除尘器、脱硫协同脱除作用以及锅炉工况负荷等方面探讨对颗粒物浓度排放系数 K值产生的影响，得出上述因素通过改变脱硫进口颗粒物浓度值影响 K值，当脱硫进口颗粒物浓度较低、波动范围较小时，其 K值也维持相对稳定的状态；当脱硫进口颗粒物浓度较高、波动范围较大时，其 K值也会发生较大的变化等结论。