The Thermodynamic Performance of a Double-Acting Traveling-Wave Thermoacoustic Engine with Liquid-Water Piston

A double-acting traveling-wave thermoacoustic engine with liquid-water piston (DTTELP) was proposed by the authors. This article conducted numerical simulation on its performance for the cases of with and without acoustical loads. The effects of mean working pressure and water-piston mass on its non-load performance were firstly discussed. Then, the output performance of this novel thermoacoustic engine under fixed heating temperature was analyzed. Also, influences of different heating temperatures on the performance of this engine were discussed. According to the simulation, the novel double-acting thermoacoustic heat engine (TTHE) is very efficient and a maximum thermal efficiency can reach about 51% when the heating temperature is 1500 K.     

碳捕获与封存（CCS）发展前景

对国内外碳捕获与封存的发展现状、争论焦点、发展瓶颈以及未来前景进行分析。碳捕获与封存技术的应用和推广可以有效地缓解全球变暖带来的不利影响,为构建低碳经济和可持续发展提供了一个不错的选择。然而世界各国由于在认识差异、经济背景、国内立法、利益相关者博弈等多种背景影响下,碳捕获与封存的发展前景仍不是特别明朗,各国在技术领先和商业利益之间的竞争还存在很多变数。     

反硝化除磷污泥的厌氧释磷与缺氧吸磷特性研究

为研究厌氧释磷过程中的影响因素,以连续流A 2N双污泥中试污泥为样品,考察了碳源种类、碳源浓度、pH值以及温度对反硝化除磷污泥厌氧释磷的影响。结果表明:乙酸为碳源时释磷效果最佳,其次是葡萄糖,甲醇为碳源时释磷效果较差。MLSS为1 200 mg/L左右时,投加200 mg/L的COD即可保证充分释磷。pH值为6.3~8.8,对厌氧释磷效果影响不大,适当提高pH值有利于提高释磷速率。温度为20~30℃,释磷效果较好。另外,实验同时研究了反硝化除磷污泥分别利用不同电子受体(硝氮、氧气)的吸磷特性。以硝氮为电子受体的反硝化吸磷过程中,前15min的反硝化吸磷脱氮速率最高,吸磷速率与反硝化速率分别为11.5、10.4 mgN/gVSS·h;以氧气为电子受体的好氧吸磷过程中,前15 min的好氧吸磷速率最高,达到20.4 mgP/gVSS·h,大约为反硝化吸磷的2倍。     

大中型锅炉应用双循环流化床烟气脱硫装置的技术经济分析

介绍了自主研制的双循环流化床烟气悬浮脱硫技术（DCFBFGD）的工艺流程、技术特点,并以里彦电厂的一台430t／h燃煤锅炉为例,对大中型锅炉应用此项技术进行了技术经济分析。分析表明,该脱硫装置适合大中型锅炉的脱硫改造,投资费用和运行成本低。     

川西地区水能资源优势、开发障碍及战略

川西地区包括甘改，阿坝，凉山，雅安，攀枝花，乐山和眉山七个州市。金沙江水电基地，雅砻江水电基地和大渡河水是基地集中分布该区域，是长江上游水能资源富集区的核心。从水系和行政区方面分析该地区水能资源分布状况，国际国内比较优势，开发利用水平，管理体制，丰枯矛盾和资金短缺等。最后提出以溪落渡，向家坝，瀑布沟和独松电站为主的开发重点；华东，西北市场开发为主的市场开拓战略方向；四川电网与华东，西北电网的联网建设，以电代柴保生态的战略；规范集资办电的投融资制度，实行项目资本金制度，明晰产权关系，进行现代化企业制度的改制方向和实行企业所得税优惠政策。     

Coming to grips with scientific ignorance in the governance of endocrine disrupting chemicals and nanoparticles

New technologies are characterized by various forms of incertitude that challenge both scientific expertise and regulatory action. In this paper, we argue that these incertitudes place experts in irreducible double bind situations, which may end in paralysis. Double binds emerge when primary injunctions are contradicted by secondary injunctions at a different logical level, which affects the interpretation of the primary injunction. Adequately addressing the challenges posed by new technologies requires phronesis, or pragmatic, context-dependent and action-oriented knowledge grounded in value deliberation. Using endocrine disruptors and carbon nanotubes as empirical examples, we argue that in relation to new technologies involving various kinds of incertitude, being phronimos—the person who can do phronesis—involves synthetically and simultaneously enacting parts of the three interrelated domains of knowledge, ethics and institutions, also across different logical levels. The special kind of experience-based phronesic skill that required in the regulatory appraisal of new technologies is thus fundamentally related to the human capacity of pattern recognition. Finally, we argue that being aware of and making full use of practical wisdom thus conceptualized enables a new operationalization of the precautionary principle.     

Modelling the propagation of an internal solitary wave across double ridges and a shelf-slope

Evolution of the internal solitary waves (ISWs) in the northern South China Sea (SCS) has recently attracted the attention of many oceanographers in Taiwan and the United States. These ISWs are believed to have been induced by a branch of the Kuroshio current over Luzon Strait, which propagates westward over two ridges in the Luzon Strait between Taiwan and the Philippines, and further onto the continental margin with a shelf-slope in the SCS. This paper presents some preliminary results for the evolution of a depression ISW across two triangular obstacles using numerical modelling and laboratory experiments. The experimental results confirm that the intervals and relative height between the two obstacles are important factors in the interaction of an ISW with the obstacles. However, in the case of the movement of an ISW of depression-type across the Luzon Strait, the effect of the two ridges on the characteristics of the ISW might be less significant than that from the shelf-slope, due to the variations in relative water depth. Results from numerical experiments also show that the amplitude of an ISW can be augmented once the wave commences its contact with a shelf-slope, where an internal hydraulic jump and wave breaking with vortex motion are evident in the laboratory experiments. Eventually, an ISW of depression-type could become an elevation-type at the edge of the continental shelf landwards beyond the turning point, where the upper layer is larger than the bottom layer in a stratified water column.     

生活污水脱氮除磷DBP工艺中试研究

中国环境科学研究院与韩国H2L公司合作开发的脱氮除磷工艺——DBP(Double Biofilm Process)工艺,即双生物膜法,是将A2/O工艺、接触氧化法和曝气生物滤池有机结合起来,通过改变设计参数和运行参数,引进纤毛填料,使这3种工艺优点互补,缺点互避,形成的一种生物脱氮除磷工艺. 通过中试试验研究该工艺处理生活污水时的脱氮除磷效果. 结果表明,该工艺对COD_Cr和SS的平均去除率分别为91.5%和94.5%,对总氮和总磷的平均去除率分别为78.4%和82.4%,出水能达到中水回用要求,且运行效果稳定.      

创新实验教学模式,提升学生实践技能——基于南京大学“三三制”教改的环境生物学实验教学探索与实践

近年来,南京大学推动了"三三制"本科教学改革,为本科学生的培养提供3个阶段(大类培养、专业培养和多元培养)和3条个性化发展路径(专业学术类、复合交叉类、就业创业类)的新模式。为实现学校"三三制"教改的目标,南京大学环境生物学实验教学团队紧扣平台建设和实验环节,以创新实验教学模式为重点,以培养学生自主实验、自主探索能力为目标,融合"基础型实验—综合型(自主)实验—创新型(研究探索)实验",激发学生的实验兴趣,形成学生积极、主动开展实验的新模式,营造良好的实验教学氛围。结果表明,上述"三三制"环境生物学实验教改方案取得了良好的教学效果,提高了学生的创新意识和实践能力,为培养高素质的环境生物学科人才进行了有益的探索。     

Stabilization treatment of contaminated soil: a field-scale application in Shanghai,China

Stabilization is one of the best demonstrated available technologies for treating toxic pollutants in soils and has been used worldwide but is rarely used for treatment of contaminated sites in China despite many bench-scale studies. Here, a field-scale application of stabilization treatment in Shanghai, China was summarized to demonstrate the whole engineering process and the key technical issues regarding stabilization of contaminated soil. A site contaminated with arsenic (As) and polycyclic aromatic hydrocarbons (PAHs), formerly used as a lighting plant in Shanghai, was chosen as the demonstration site. Stabilizing measures were taken to treat the contaminated soil to reuse the site for residential purposes. The whole engineering remediation process consisted of phase I environmental site assessment (ESA) and phase II ESA, quantitative human health risk assessment, remediation alternatives evaluation, bench-scale testing, remedial design, engineering implementation, and post-remediation assessment. A third party conducted evaluation monitoring indicated desirable results were achieved via the stabilization treatment. In addition, some technical obstacles related to soil stabilization treatment were discussed, including soil quality evaluation, stabilization effectiveness validation, and soil reuse assessment.