碳管制效率、政府能力与碳排放

在碳约束时代追求经济增长与环境保护双赢发展的要求下,探索兼顾发展与控制的平衡路径具有重要的意义。本文构造了一个引入随机边界分析的STIRPAT模型,从国际比较的视角,研究政府能力和碳管制效率对控制碳排放的影响作用。研究结论显示,过去10多年来,各国的碳管制效率并没有太大的改进,且在2008年金融危机期间还出现了明显的下降,表明各国在探索提升碳管制效率以及有效控制碳排放方面还有很长的路要走。中国的碳管制效率总体上位居世界前列,超过了美国和欧盟,但低于日本,碳管制领域的法制力度和政府效率是影响中国碳管制效率提升的主要因素,而加强政府能力将有助于提升碳管制效率,进而促进节能减排。

稀缺租金视阈下基于MAC和SCC的碳管制分布式效应分析

在气候变化经济学的视角下引入稀缺租金分析碳管制政策的成本,选取了碳排放权交易和碳税这两种国际主流的碳管制政策,基于Nordhaus的对数函数和气候变化综合评估模型核算了MAC和SCC,开展了碳管制的分布式效应评估。研究结果表明:稀缺租金视角下的碳管制成本取决于一般均衡成本、因素禀赋和消费模式,碳管制的分布式效依赖于价格效应和福利效应。从成本效益角度分析,碳排放权交易和碳税均可以增加政府收益,祖父许可证制度更有利于实现效率和公平。此外,Nordhaus的对数函数和IAM模型具备自洽性、系统性和可行性,对碳管制的分布式效应评估提供了思路。

碳排放管制下食品供应链的优化与可持续发展研究

本文探讨了在碳排放管制框架下,如何优化食品供应链以实现可持续发展的问题。首先,通过分析技术创新在生产优化、运输与物流以及供应链信息化管理中的应用,揭示了技术创新对降低碳排放和资源利用效率的重要作用。其次,探讨了政策支持对食品供应链可持续发展的影响,特别是碳排放配额制度、税收政策激励和政府与企业的合作机制。结果表明这些政策和技术手段不仅有助于减少碳足迹,还能提升供应链的整体效率和环境可持续性。最后,本文总结了当前研究的主要成果和存在的挑战,为未来制定更加有效的碳排放管制策略提供了理论和实践基础。

碳管制与交易政策下企业生产管理优化问题

碳管制与交易政策是一种有效的减排政策。首先研究了在碳管制与交易政策下,企业的最佳生产量和相应的期望利润,并且分析了碳管制与交易政策对企业管理和决策的影响。由于考虑了碳足迹的限制,企业的最优生产量要小于仅仅以利润为目标的最优生产量,且存在一个与企业碳交易相关的阈值。当该阈值超过、等于或小于碳限额时,企业可以买入、卖出碳权或不进行交易,此外分析了碳限额、碳价、碳足迹对最佳生产量和企业总利润的影响。最后,通过仿真数值分析验证了理论的有效性,同时对研究结果做出了具有现实意义的评价与解释。

基于DEA模型的中国碳排放管制效率研究

选择投入、产出变量构建超效率数据包络分析(DEA)模型,计算中国不同省份的碳排放管制效率,研究碳排放管制效率的区域差异。结果发现,中国碳排放管制效率整体呈现出逐年提高的趋势,但区域差异性明显,东部地区的碳排放管制效率较高,中部地区次之,西部地区较低,东北区域则出现剧烈、波动;城市化水平、对外开放程度和产业结构优化程度对中国碳排放管制效率存在显著影响,过度城市化会降低碳排放管制效率,提高对外开放程度和产业结构优化程度可以提高碳排放管制效率。

碳排放管制对区域绿色创新效率的影响研究

为探究我国碳排放管制对绿色创新效率的影响,本文基于2005—2019年我国30个省、直辖市、自治区(西藏及港、澳、台地区除外)的面板数据对碳排放管制及绿色创新效率进行测算,通过门槛回归模型探讨二者之间的关系。研究发现:碳排放管制与区域绿色创新效率之间存在单一门槛值,二者呈现倒“U”型关系,随着第二产业总产值比重不断下降,碳排放管制对区域绿色创新效率表现出先促进后抑制的作用。

碳排放管制政策会影响企业创新产出吗?

绿色低碳发展是我国生态文明建设的重要内容,逐渐推广的碳排放交易试点是践行低碳发展理念的重要工具,那么碳排放管制政策将会对企业的创新产出产生促进作用,还是抑制作用呢?这是本文将要探索的问题。本文以2007-2016年A股上市公司为研究对象,采用三重差分法进行分析,研究发现碳排放管制政策会促进企业创新产出;进一步区分企业产权性质,并采用Bootstrap法分析后发现碳排放管制政策对国有控股企业的创新产出促进作用更显著。研究结果在通过PSM-DID、安慰剂检验后仍然稳健。本文研究结论丰富了我国碳排放管制政策的经济后果文献,对于积极践行绿色发展和可持续发展理念具有一定的支撑作用。

碳交易和绿色补贴政策下的低碳供应链最优决策与协调

考虑政府的碳交易管制和绿色补贴政策,针对由政府、单个制造商和单个零售商组成的三级低碳供应链,运用博弈理论建立了政府主导下的三阶段Stackelberg博弈模型和集中决策模型。重点分析了消费者绿色偏好、碳交易价格和减排成本系数对低碳供应链最优决策和社会福利的影响。利用两部收费契约和低价促销策略分别对所建模型进行了协调研究,并利用数值算例对文中结论进行了验证。研究发现:较强的消费者绿色偏好有利于提高产品的绿色度、渠道成员的利润和供应链的社会福利;产品的绿色度和供应链的社会福利水平在集中决策模型下最高;政府的最优绿色投资补贴率在消费者绿色偏好程度较强时降低而在碳减排难度较大时上升;在参数满足一定条件下,两部收费契约和低价促销策略可实现低碳供应链的完美协调。

关于低碳经济引发国际市场营销的思考——基于环境政策变化促进技术创新角度分析

改革开放三十年来,中国粗放式经济或说"高碳经济"发展的背后付出了很大的资源和环境代价,发展低碳经济,顺乎世界潮流,成为了中国可持续发展的必由之路。低碳经济的提出必将引致环境政策的变化,继而改变市场的营销环境,而技术创新、新能源开发将是低碳时代的核心竞争力所在。

我国碳排放配额初始分配方式的法学探究——以行政法律关系为视角

碳排放配额初始分配方式,是指在碳交易一级市场中,政府在碳排放总量控制的前提下,将碳排放配额分配给碳排放管制对象所采取的方式,包括有偿方式和无偿方式。从我国七试点省市碳排放配额初始分配方式的考察入手,分析了碳排放配额初始分配方式的类型及其利弊,在有偿分配方式下,一般采取政府拍卖方式,政府和碳排放管制对象形成的法律关系为行政合同关系;在无偿分配方式下,又可划分为祖父制和基准线法两种,政府和碳排放管制对象形成的法律关系为行政许可关系。建议在选择何种分配方式时,从选择建立最为适合一级市场的碳交易法律关系可以推导出最优的分配方式,强调在选择建立法律关系时既要体现政府的主动性、强制性,又要体现在发生纠纷时相对救济途径的多样性和灵活性。

低碳投筹资市场政策研究

随着低碳经济持续发展,碳金融市场越来越活跃。本文阐述了我国低碳间接和直接投筹资市场的各自发展政策,提出我国应进一步健全商业银行的低碳金融服务领域,持续完善低碳间接投筹资市场的功能,在此基础上提出完善低碳金融市场监管制度的策略。

奥巴马政府绿色经济新政及其启示

2009年,奥巴马政府提出将发展绿色经济作为基本施政纲领,实施温室气体排放总量管制和排放权交易制度,并出台政府参与、税收减免、出口退税、征收碳许可费等政策加大支持力度,以应对当前经济危机与获得新的国际竞争力,实现经济可持续发展的双赢。目前,发展绿色经济已成为世界经济发展大潮,对此,我国政府和企业必须要有清醒认识,及时采取有效措施,努力提升绿色经济技术创新能力,增强国际竞争力。

Tribological behavior of A356-CNT nanocomposites fabricated by various casting techniques

Tribological behaviors of monolithic A356 aluminum alloy castings and A356.CNT nanocomposite castings, fabricated by fully liquid and semisolid routes were examined. Samples were prepared by melt agitation, rheocasting, stir casting, and compocasting techniques. Effects of addition of carbon nanotubes (CNTs), casting process and the applied load on wear properties and mechanisms were investigated. It was found that wear loss, wear rate and friction coefficient of nanocomposite samples remarkably declined by the addition of CNTs. Moreover, changing the casting process from fully liquid to semisolid routes, plus increasing fractions of the primary phase were the two factors that improved the wear properties of the investigated samples, especially nanocomposite ones. In addition, it was revealed that adhesion and delamination were the dominant wear mechanism of the monolithic samples produced by fully liquid and semisolid routes, respectively. However, regardless of fabrication techniques, the abrasion was the main wear mechanism of nanocomposite samples.

Enhanced Field Emission from Printed Carbon Nanotubes by Hard Hairbrush

A method, the morphology of screen printed carbon nanotube pastes is modified using a hard hairbrush, is presented. In this way, the organic matrix material is preferentially removed. Compared to those untreated films, the turn-on electric field of the treated film decreases from 2.2V/μm to 1.6V/μm, while the total emission current of the treated increases from 0.6mA/cm2 to 3mA/cm2, and uniform emission site density image has also been observed.

Effects of Cu content on microstructures and compressive mechanical properties of CNTs/Al-Cu composites

The carbon nanotubes(CNTs) reinforced Al-Cu matrix composites were prepared by hot pressing sintering and hot rolling, and the effects of Cu content on the interfacial reaction between Al and CNTs, the precipitation behavior of Cu-containing precipitates, and the resultant mechanical properties of the composites were systematically investigated. The results showed that the increase of Cu content can not only increase the number and size of Cu-containing precipitate generated during the composite fabrication processes, but also promote the interfacial reaction between CNTs and Al matrix, leading to the intensified conversion of CNTs into Al_(4)C_(3). As a result, the composite containing 1 wt.% Cu possesses the highest strength, elastic modulus and hardness among all composites, due to the maintenance of the original structure of CNTs. Moreover, the increase of Cu content can change the dominant strengthening mechanisms for the enhanced strength of the fabricated composites.

An experimental study on thermal characteristics of nanofluid with graphene and multi-wall carbon nanotubes

High-thermal conductivity enhancement of nanofluid is one of the promising topics of the nanoscience research field. This work reports the experimental study on the preparation of graphene(GN) and multi-walled carbon nanotubes(MWCNTs) based nanofluids with the assistance of sodium dodecyl benzene sulfonate(SDBS) and sodium dodecyl sulfate(SDS) surfactants, and their thermal behaviors. The present work suggests not a solution, but a solution approach and deduces a new conclusion by trying to resolve the agglomeration problem and improve the dispersibility of nanoparticles in the base fluid. The analysis results of FESEM, thermal conductivity, diffusivity, effusivity and heat transfer coefficient enhancement ratio of nanofluid with surfactants SDS and SDBS expose strong evidence of the dispersing effect of surfactant on the making of nanofluid.

Properties of CNTs/MoSi2 composites prepared by spark plasma sintering

Molybdenum disilicide(MoSi_2) based composites with various contents of carbon nanotubes(CNTs) were fabricated by spark plasma sintering(SPS) in vacuum under a pressure of 25 MPa.The composites obtained under a sintering temperature of 1500 °C and time of 10 min exhibited optimum mechanical properties at room temperature in terms of fracture toughness and transverse rupture strength.MoSi_2 based composite with 6.0% CNTs(volume fraction) had the highest fracture toughness,transverse rupture strength and hardness,which were improved by about 25.7%,51.5% and 24.4% respectively,as compared with pure MoSi_2.A Mo_(4.8)Si_3C_(0.6) phase was detected in CNTs/MoSi_2 composites by both X-ray diffraction(XRD) method and microstructure analysis with scanning electron microscopy(SEM).It is believed that the fine grains and well dispersed small Mo_(4.8)Si_3C_(0.6) particles had led to a higher hardness and strength of CNTs/MoSi_2 composites because of their particle pullout,crack deflection and micro-bridging effects.

A carbon nanotube-based sensing element

A carbon nanotube-based(CNT) sensing element is presented, which consists of substrate, insulating layer, electrodes, carbon nanotube and measuring circuit. The sensing components are a single or array of CNTs, which are located on the two electrodes. The CNT-based sensing element is fabricated by CVD (chemical vapor deposition)-direct-growth on micro- electrodes. The sensing model and measurement method of electromechanical property are also presented. Finally, the voltage-current characteristics are measured, which show that the CNT-based sensing element has good electrical properties.

Effect of carbon nanotube and silicon carbide on microstructure and dry sliding wear behavior of copper hybrid nanocomposites

Microstructure and tribological properties of copper-based hybrid nanocomposites reinforced with copper coatedmultiwalled carbon nanotubes (MWCNTs) and silicon carbide (SiC) were studied. Carbon nanotube was varied from 1% to 4% withsilicon carbide content being fixed at 4%. The synthesis of copper hybrid nanocomposites involves ball milling, cold pressing andsintering followed by hot pressing. The developed hybrid nanocomposites were subjected to density, grain size, and hardness tests.The tribological performances of the nanocomposites were assessed by carrying out dry sliding wear tests using pin-on-steel disctribometer at different loads. A significant decrease in grain size was observed for the developed hybrid composites when comparedwith pure copper. An improvement of 80% in the micro-hardness of the hybrid nanocomposite has been recorded for 4% carbonnanotubes reinforced hybrid composites when compared with pure copper. An increase in content of CNTs in the hybridnanocomposites results in lowering of the friction coefficient and wear rates of hybrid nanocomposites.

An improved fabrication method for carbon nanotube probe

An improved arc discharge method is developed to fabricate the carbon nanotube probe. In this method, the silicon probe and the carbon nanotube were manipulated under an optical microscope. When the silicon probe and the carbon nanotube were very close, 30-60 V dc or ae was applied between them, and the carbon nanotube was divided and attached to the end of the silicon probe. Comparing with the arc discharge method, the new method need not coat the silicon probe with metal in advance, which can greatly reduce the fabrication difficulty and cost. The fabricated carbon nanotube probe exhibits the good property of high aspect ratio and can reflect the true topography more accurately than the silicon probe.