To avoid global warming by 2°C—mission impossible

Investigations have been carried out into the basic implications of the decisions taken in December 2015 at the Paris conference of the countries–participants of the UN Framework Convention on Climate Change for the world energy and for the atmosphere and climate. Based on the studied historical record of specific CO₂ emissions in the energy production by different countries, it is shown that the implementation of the Paris Agreement will require an unprecedented effort to modernize the global energy sector; in particular, rapid elimination of coal from the global energy mix and a substantially increased share therein of carbon-free energy sources (hydro and nuclear power and alternative renewable energy sources (renewables)) to one third by the middle of this century. We have developed a scenario for the global energy demand mix corresponding to the guidelines of the Paris Agreement and its more conservative variant extending the trend of the last 15 years. It has been established that, under any of the development scenarios, the global mean temperature is to exceed the level of 1.5°C as soon as within a few decades. Using model simulations of the changes in the atmosphere and climate, we show that even the full implementation of the Paris Agreements will not prevent the increase in average global temperature by 2°C as compared to the preindustrial levels. The world community faces a difficult choice between the implementation of more stringent measures for reducing greenhouse gas emissions, which we believe to be almost unreal, and adaptation to utterly new climatic conditions, which will last for centuries to come.     

应用人工神经网络预测棒-板短空气间隙在淋雨条件下的交流放电电压

为了获得降雨条件下能预测空气间隙击穿电压的数学模型,根据在人工气候室试验得到的降雨条件下空气间隙击穿电压数据,运用神经网络原理,建立了降雨条件下的交流棒-板短空气间隙击穿电压的人工神经网络模型。利用该模型可以对一定降雨条件下的交流棒-板短空气间隙击穿电压进行预测,预测结果满足精度要求,同时,该文根据建立的人工神经网络模型模拟了降雨时单个及多个环境因素对空气间隙击穿电压的影响,并对模拟结果进行了分析,结果表明:大气压强一定时,随着降雨强度、雨水电导率的增加以及环境温度的降低,空气间隙的击穿电压随之降低;当降雨强度、雨水电导率和环境温度其中任一环境因素改变时,另两个因素对空气间隙击穿电压的影响程度也随之改变。人工神经网络模型对训练数据的依赖较大,对训练范围以外的数据预测精度较差。     

多源数据驱动的黄河未来水沙变化趋势研究

由于近年来气候变化和人类活动的双重影响,导致黄河水沙锐减,对未来变化趋势作出可靠判断十分必要。利用基于多种机器学习特征筛选的统计模型方法,采用潼关站实测径流量与输沙量、欧洲中期天气预报中心中尺度数据及不同气候变化路径的CO2排放浓度下全球气候模式数据对未来水沙作了预测。结果表明,在rcp26情景下,潼关站未来10年、20年、50年的断面径流量为234.21亿m3、227.52亿m3、219.6亿m3,与2000—2016年平均径流量228.86亿m3相比,径流量增加了约2.3%、-0.5%、4.0%;同期的断面输沙量预测结果为2.68亿t、3.44亿t、5.72亿t,与2000—2016年平均输沙量2.48亿t相比增加了约7.9%、38.4%、130.2%,表明黄河流域“水少沙多”的形势依然是未来较长一个时期的主要特征。     

Low‐temperature direct bonding of poly(methyl methacrylate) for polymer microchips

A low‐temperature, direct bonding method for poly(methyl methacrylate) (PMMA) plates has been developed by employing surface treatment by atmospheric pressure oxygen plasma, vacuum oxygen plasma, ultraviolet (UV)/ozone or vacuum ultraviolet (VUV)/ozone. Reasonable bonding strength, as evaluated by a tensile test, was achieved below the glass transition temperature (T_g). The highest bonding strength among the achieved results is 1.43 MPa (about three times the value for conventional direct bonding) at an annealing temperature of 50 °C and an applied pressure of 2.5 MPa for 10 min. Low‐temperature bonding prevents deformation of the PMMA microstructure. A prototype PMMA microchip that has fine channels of 5 µm depth was fabricated by hot‐embossing using a Si mold. After atmospheric pressure oxygen plasma activation, direct bonding was carried out at an annealing temperature of 75 °C and an applied pressure of 3 MPa for 3 min. The method gives good bonding characteristics without deformation and leakage. This low‐temperature bonding technology can be applied to polymer micro/nano structures. Copyright © 2007 Institute of Electrical Engineers of Japan© 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

计及高比例可再生能源运行特性的中长期电力发展分析

面对日益严峻的气候和环境问题,过去的高消耗、高排放的能源发展模式已难以为继,建立以可再生能源为主体的能源,特别是电力供应体系,实现能源清洁低碳转型发展成为大势。首先,介绍了面向高比例可再生能源的中长期电力发展研究思路。接着,提出了多区域、多场景中长期电力规划模型,该模型以全社会电力供应成本最小化为优化目标,考虑了电力系统扩展规划、运行、发电资源及能源电力政策等多方面约束;通过电力系统运行模拟在规划问题内的适度耦合,可计及风光等可再生能源发电的随机性与波动性。最后,基于所提规划模型,展望了中国2050年高比例可再生能源电力系统的电源格局与电力流,并对系统整体运行情况进行了分析。     

气压对直流正极性下冰柱-冰板间隙电晕放电的影响

为进一步了解低气压下覆冰对绝缘子的危害,该文选择冰柱-冰板间隙模型,借助数据采集卡、紫外线成像仪和自行设计的电流传感器等设备,在人工气候室内研究低气压下冰柱-冰板模型的电晕放电特性。文章分析了气压对冰柱-冰板间隙的起晕电压、平均放电量和冰柱尖端处的放电区域等方面的影响。结果表明：起晕电压随着气压的降低而降低,平均放电量和冰柱尖端处的放电区域均随着气压的降低而减小,同时,在较低气压下,起始放电更容易形成辉光放电,放电测量也更困难。     

基于全局和局部最优模型的电动汽车充放电优化调度

电动汽车大规模入网将对电网产生重大影响。针对大规模具有动态响应特性的电动汽车充放电问题,提出了全局最优调度和局部最优调度两种模型。通过电动汽车响应的实时电价模型,分别建立含电池损耗成本、连续可微、带线性约束的凸目标函数。全局最优模型需要负载和电动汽车各项信息求解全局总成本最小的调度方案。局部最优调度模型对电动汽车进行分组,以分布式模式最小化滑动窗口内电动汽车组的总成本。通过内点法对两种模型求解表明:局部最优调度方案可以扩展到大型电动汽车群,对电动汽车的动态到达特性具有弹性。相对于全局最优调度模型复杂的求解信息,局部最优调度方案具有更高的实用性和相近的求解结果。     

Streamer discharges in liquids and their applications

Industrial applications using pulsed power technologies have been developed in many fields. One of them is the treatment of exhaust gas by using uniformly produced streamer discharges. Streamer discharges in liquid also generate extremely high electric fields at the tip of streamers, as well as high energy electrons, ozone, other chemically active species, ultraviolet rays and shock waves. All of these may be utilized to sterilize microorganisms and to decompose molecules and materials. Large-volume streamer discharges in water have been produced in order to realize industrial applications. A wire to plane electrode configuration has been used. The discharge in water shows similar optical radiation to that in an atmospheric gas as provided by evidence from still photographs. The influence of polarity, conductivity, electrode geometry and hydrostatic pressure on the streamers in liquid, the mechanism of streamer discharges and possible industrial applications of streamers in liquids, are discussed in the present work     

变化环境下东北半干旱地区径流演变规律分析——以洮儿河流域为例

受气候变化和人类活动影响,众多河流的径流量发生了改变,深入解析历史径流变化成因并探究未来径流演变趋势,是流域水资源科学管理的必然需求。本文以洮儿河流域为研究区,基于SWAT模型定量揭示历史径流变化原因,并结合未来气候情景,探究未来径流演变趋势。结果表明：洮儿河流域历史年均气温呈显著上升趋势,降水、径流均呈现一定下降趋势;气候变化和人类活动分别是洮儿河流域上游和下游径流变化的主要成因。在未来BCC-CSM2-MR（CMIP6）气候模式下,三种不同排放情景的未来期年均径流量相比于基准期变化-10.14% ~ 16.86%,未来水资源利用将面临更大挑战。研究成果可为深入理解流域历史径流变化成因及未来水资源演变趋势提供科学依据,为流域水资源规划和管理提供决策支持。     

光伏系统中地基云图的预处理

用于地面天空监测和辐射预测的地基云图,由于其拍摄仪器全天空成像仪(TSI)自身的缺陷,使得拍摄的天空图像中存在较大面积的遮挡和一定程度的畸变,从而导致基于地基云图的云识别、分类和辐射预测等不准确。针对该问题,提出了一种镜像渐变修复方法来还原真实天空云分布情况。首先通过计算太阳在图像中的位置,自动确定遮挡区域;然后根据云的颜色特性,采用镜像渐变算法进行修复;接着,对太阳周围的白色像素点,根据太阳辐射衰减程度将其分割为云或晴空,并对识别为晴空的过度曝光像素点进行修正。实验表明,所提出的预处理方法可快速还原真实天空的云分布信息,且修复效果优于现有光伏系统上使用的方法,为后续气象变化研究和辐射预测等提供了条件。     

低碳经济对电网规划和发展的影响

能源、环境和气候变化问题是当今世界关注的焦点,低碳经济是全球经济发展的大势所趋,是中国经济发展的必由之路。对这一问题进行初步探讨并且提出:低碳经济将深刻地影响电力需求水平、分布、结构,电源的效率提高、合理布局,新能源的比重、核电的发展、水资源的利用、煤炭资源的开发与利用等,电网的发展方向、远距离输电网的比重、大电网合理规模和结构、智能电网的发展方向和重点、城市与农村电网的发展趋势等;低碳经济对电网发展影响主要是通过对负荷和电源的影响而实现的,这些影响更多的是正面的,分布式电源、油气电站、分散式太阳能电站,包括核电,由于其自身的特点,需要建设在负荷中心地区,缩短了电源与负荷的距离,对保障电网的安全经济可靠供电是有利的。     

基于WRF湖泊模型的糯扎渡水库未来水温模拟

水库水温对河流水生态环境以及局地气候有重要影响。未来气候变化背景下,水库水温的响应受到国内外关注。本文以气候模式WRF中的湖泊模型为基础,对未来气候态下（RCP2.6、RCP8.5）糯扎渡水库水温变化趋势进行模拟。研究发现,不同未来气候态下,糯扎渡水库水温均呈现上升趋势,且表层水温比深层水温对气候变化的响应更显著。本世纪末水库表层水温上升幅度在4 °C以内,深层水温上升0.8 °C左右。     

介质阻挡放电中的紫外线预电离

为解决大气体下尤其是空气辉光放电产生等离子体的困难,通过采用脉冲火花放电产生的紫外线对介质 阻挡放电预电离试验研究了紫外线预电离对降低空气击穿场强、“点燃”主放电的作用和气压与主放电频率对预电 离的影响;探讨了与气体流动等条件相结合,用预电离方法实现大气压下空气中辉光放电的可能性。     

Lessons captured from 50 years of CCS projects

Carbon capture and storage (CCS) can help mitigate climate change on a global scale. This article examines the 26 CCS facilities currently in operation around the world that have safely captured and stored 300 million metric tonnes of carbon dioxide. These facilities demonstrate that the technology has successfully been deployed to scale and can safely capture and store carbon dioxide. This article shares the lessons learned that will help guide the future deployment of more projects.     

U.S. energy,climate and nuclear power policy in the 21st century: The primacy of national security

This paper analyzes global and regional energy and CO₂ trends and concludes: 1) Domestic U.S. policies alone will not insulate the U.S. from the impacts of climate change; 2) The U.S. should triage climate change as a global threat by focusing on regions where CO₂ emissions are most acute; and 3) The U.S. civilian nuclear enterprise should be elevated in U.S. energy and climate policy in order to meet global climate and national security objectives.     

Sustainability: from concept to practice

Nature is reacting to the activities of industrial societies in unanticipated and surprising ways. The prospect of global climate change, the thinning of stratospheric ozone, the increasing acidification of rain, snow, and even large bodies of water, and the steady decline in biodiversity have all been linked to the spread of industrial development. Yet the predominant view until recently has been that human activity had little, if any, determinative role in the natural order. Now scientists are increasingly persuaded of the critical impact of human activities on the natural order. This paper takes up the challenge of articulating an alternative technological pathway that can improve society's relationship with the natural environment. The new pathway draws upon one of the most important ideas of the late twentieth century: sustainable development. The concept of sustainable development has become the standard bearer for efforts to redefine technology and society in more environmentally thoughtful, conserving, and equitable ways     

太阳直射光谱辐射火用分析

利用Gueymard给出的太阳光谱数据和Candau提出的光谱辐射火用强度的定义计算地表直射太阳辐射的积分辐射火用流,分析地表直射太阳辐射的光谱辐射温度、光谱辐射火用和光谱能质因子随波长的分布,讨论大气条件如可凝结水量和空气质量对地表直射太阳积分辐射火用流的影响。结果表明,在近紫外线、可见光以及近红外区域,0.76~1.343 mm波长范围内的地表直射太阳光谱能质因子和积分辐射火用流的增量比在其他波长范围内的大。对于地表直射太阳辐射的多光谱利用,需要着重考虑近紫外线、可见光以及0.76~1.343 mm波长范围内的太阳辐射。地表直射太阳积分辐射火用流分别随着可凝结水量和空气质量的增加而减小。空气质量对地表直射太阳积分辐射火用流的影响较大。     

The Actuality and Progress of Whole Sky Infrared Cloud Remote Sensing Techniques

Clouds are crucial regulators of both weather and climate. Properties such as the amount, type, height, distribution and movement of them have an impact on the earth''s radiation budget and the hydrological cycle, thus cloud observation is very important. The disadvantages of zenith pointing measuring instruments and whole sky visible imagers limit the application of them. A summary of the actuality and application of ground-based whole sky infrared cloud measuring instruments and analyses of the techniques of radiometric calibrations, removal of atmospheric emission and calculation of cloud cover, amount, type are conducted to promote the automatically observation of the whole sky. Fully considering whole sky infrared cloud sounding theories, techniques and applications, there are still a lot of studies on improving the properties of instruments, enhancing the techniques of cloud base height measurements and establishing instrumental cloud classification criterion before actual operations.     

大气压下同轴圆柱反应器DBD等效电路模型参数预测

大气压下同轴圆柱反应器介质阻挡放电在气体处理领域应用广泛。反应器等效电路模型是高性能介质阻挡放电电源设计的关键。然而,反应器等效电路模型参数随工作状况而非线性变化,这增加了复杂工况下系统精准设计的难度。针对这一问题,在非线性钳位等效模型的基础上采用遗传算法优化的神经网络对反应器等效模型参数进行预测。以系统的电压幅值、工作频率、气体流速和气体温度作为模型输入,以非线性钳位模型的钳位电压、介质等效电容和气隙等效电容作为模型输出。实验结果表明,在较宽的预测范围内,该方法保持较高的预测精度。利用该方法在全局范围内对反应器介质阻挡放电等效模型参数进行预测,可以为复杂工况下的电源设计提供更准确的反应器等效模型。     

考虑未来径流变化的丹江口水库多目标调度规则研究

气候变化会引起水文循环和入库径流变化,改变当前水库各调度目标的制约关系,影响水库调度规则。考虑未来径流变化对水库调度的影响,推求相应的水库多目标调度规则对未来水库管理有着重要意义。本文以丹江口水库为例,建立了考虑未来径流变化的多目标优化调度模型。以全球气候模式(GCM)模拟结果作为未来气候变化情景,将降尺度处理后的气象要素输入可变下渗能力(VIC)模型预测丹江口水库未来入库流量序列,采用非支配排序遗传算法(NSGA-II)算法推求多目标调度函数集,结合设计的水库调度图得出兼顾丹江口水库供水和发电的多目标调度规则。通过对比分析发现,目前的调度规则不能很好地适应未来径流变化,而考虑未来径流变化的多目标优化调度规则能有效协调供水和发电的矛盾。以发电和供水为主两种不同调度规则对各目标的影响存在差异,其中主要考虑供水的调度规则能显著提高(18.7%)水库的供水量。