用煤权初始配置、影子价格与交易机制

用煤权制度对中国煤炭总量控制、全国与区域节能减排目标保持一致、大气污染治理具有重要作用。首先,本文基于公平、效率、奖惩、可行性和可持续发展原则,选取代内公平、投入效率、产出效率、经济奖惩、环境奖惩、历史连贯、产业结构、环境承载力和环境防治力9个指标,采用主成分分析法和变异系数法确定各项指标权重,以2020年与2025年为例,将预测得到的全国用煤权总量上限在一级市场初始配置给30个省份。其次,运用投入距离函数,测算2020~2025年除重庆外其余29个省份的用煤权影子价格,并通过分解影子价格得到用煤权的理论交易价格。最后,设计用煤权二级市场交易机制,结合30个省份环保税中对各种污染物的税收水平与碳排放权现实交易价格,计算得到了只考虑环保成本而未包含经济收益等因素的2020~2025年全国用煤权单纯环保价格,该价格可以作为用煤权市场失灵等极端情况时政府指导定价的最低价格。

基于ARIMA和GM(1,1)模型的煤炭市场需求预测研究

"富煤贫油少气"的能源禀赋决定了煤炭在中国能源生产和消费中的绝对主导地位,但长期大量使用煤炭导致了严重的环境问题,东部沿海经济发达地区的生态压力尤为突出,"控煤"已经成为各界共识和现实政策。分析煤炭消费现状,预测未来煤炭需求,是统筹煤炭消费减量替代与经济发展、环境保护的基础和起点。本文从行业、区域等角度分析了中国煤炭消费的主要特点,进而采用ARIMA模型、GM(1,1)模型与组合预测模型,对全国及京津冀、长三角、珠三角地区2017~2025年煤炭消费需求总量进行了预测,发现全国2020年煤炭消费总量能够达到预定目标,但仍面临煤炭消费需求不断扩大的压力;京津冀、长三角、珠三角地区的煤炭消费需求总体上都呈现缓慢持续下降趋势,其中珠三角地区煤炭消费总量和减少速度最为理想,京津冀地区次之,长三角地区煤炭消费总量和减少速度都不理想。最后,本文提出了加大节煤减排力度,进一步淘汰落后产能,严控煤炭增量消费,促进煤炭的清洁利用,鼓励煤炭消费终端"煤改气""煤改电"与清洁能源消费,禁煤和能源替代等政策逐步由京津冀、长三角、珠三角地区向其他重点城市和省区推广。

高管团队异质性、税收优惠与技术创新——来自2013~2017年制造业上市央企的证据

技术创新是企业的核心成功因素和永恒追求,对中国企业更具有特殊意义。本文采用2013~2017年沪深A股制造业上市央企的专利和财务数据,研究了高管团队异质性和税收优惠对企业技术创新的影响。研究发现,总体上,高管团队身份异质性、工作职能异质性、隐性薪酬差距和税收优惠都与技术创新负相关。进一步分组分析发现,高管团队身份异质性在轻工业与非高新技术产业领域具有显著负向影响,而工作职能异质性的显著负影响体现在重工业与高新技术产业领域,且仅在东部地区成立,在中、西部地区不成立。行业分组和区域分组后,隐性薪酬差距的影响不再确定。税收优惠与技术创新在行业和区域分组后仍然负相关。影响作用由高到低依次为高管团队身份异质性、工作职能异质性、税收优惠和隐性薪酬差距。前期超额实质性创新对后期实质性创新产出具有决定性促进作用,前期超额策略性创新对后期技术创新总产出和策略性创新产出具有决定性促进作用,但对后期实质性创新产出没有促进作用。

Hydrochlorination of Acetylene Using SiC Foam Supported Structured C/Au Catalysts

AuCl3 loaded structured catalysts were prepared on SiC foam supported with pre-coated activated carbon layers. The catalytic properties of the structured catalysts towards hydrochlorination of acetylene were tested in a fixed- bed reactor with the AuCl3 loaded on activated carbon pellets as a reference. For isopyknic catalysts, the structured catalyst with only one fifth of the Au amount as that was used on the reference catalyst exhibited even a little higher acetylene conversion and much better stability than the latter no matter what the gas hourly space velocities of acetylene were used. The results indicated that the more homogeneous distribution of AuCl3 particles and better heat transfer along the fixed-bed reactor originated from the low pressure drop and high thermal conductivity of the SiC foam supported structured catalysts might be able to account for their improved efficiency and stability. It is befieved that these novel structured C/Au catalysts can be potentially applied in VCM industrialization in view of their greatly reduced cost and much prolonged life.

Nitrogen-doped amorphous carbon coated mesocarbon microbeads as excellent high rate Li storage anode materials

A composite anode material consisting of a stable inner core of mesocarbon microbeads and a porous nitrogen-doped amorphous carbon shell active for lithium storage is prepared. The thin birnessite MnO_2 nanosheets hydrothermally deposited on mesocarbon microbeads are in situ replaced by polypyrrole,which is then transformed to nitrogen-doped amorphous carbon layer by calcination in nitrogen atmosphere. The surface modified mesocarbon microbeads exhibit average discharge capacities of 444 and103 m A h g^(-1) at the current densities of 0.1 and 3 A g^(-1) , respectively, obvious higher than the corresponding values of the bare sample, 371 and 60 mA h g^(-1) . Moreover, the composite anode maintains a discharge capacity of 306 mA h g^(-1) after 500 cycles at 1 A g^(-1) , suggesting an excellent cycle stability. It is believed that the nitrogen-doped amorphous carbon layer has provided additional lithium storage capacity and stabilized the structure integrity of mesocarbon microbeads. This work demonstrates that the capacity and rate performance of commercial graphitic carbons can be much improved by simply introducing a nitrogen-doped carbon coating layer active for Li storage, making them attractive for high power Li-ion batteries.

Copolymerization-Assisted Preparation of Porous LiMn_2O_4 Hollow Microspheres as High Power Cathode of Lithium-ion Batteries

Porous LiMn2O4 hollow microspheres were facilely prepared by incorporation of Li and Mn elements into a spherical polymeric precursor through copolymerization of lithium and manganese acetates with resorcinol and hexamethylenetetramine and then burning off the organic matrix at appropriate temperatures in air. The LiMn2O4 inherited the spherical morphology of the polymeric precursor but showed hollow porous structure assembled by nanocrystals of about 50–100 nm in size. When tested as cathode of Li-ion batteries, the LiMn2O4 hollow spheres exhibited excellent rate capability and cycle stability.A discharge capacity of above 90 mAh g-1was maintained at 10 C（1C = 120 mAg-1）, and the cells can still deliver a discharge capacity over 100 mAhg-1after another 115 cycles at 0.5 C. With such excellent electrochemical properties, the prepared LiMn2O4 hollow microspheres could be promising cathode of Li-ion batteries for long term and high power applications.

LiCoO_2/LiNi_(0.8)Co_(0.15)Al_(0.05)O_2混合正极的颗粒级配与电化学性能

通过机械球磨制备不同质量比的LCO/NCA混合正极材料,采用X射线衍射仪(XRD)和扫描电子显微镜(SEM)表征其相结构和微观形貌,研究了这种材料的电化学性能。结果表明,两种正极材料球磨混合后其晶体结构均未改变,但是初始的NCA球形二次颗粒被打散,形成的纳米粒子弥散填充在LCO微米颗粒的孔隙之间,提高了正极材料的涂膜密度和二者之间的接触紧密性。当LCO:NCA=6:4时混合正极材料具有最佳的颗粒级配效果,其首次充放电效率最高,为92.4%;在10 C (1 C=140 m A·g-1)倍率下的比容量(136 mA·h·g-1)是0.2 C时的78.0%,出现了明显的协同增强效果;在1 C倍率下循环100次其容量保持率为89.8%,表现出优异的电化学性能。

Novel TiC/Ti Open Cellular Foams Prepared by a Modified Sponge-coating Method Using High Frequency Induction Heating Process

A new kind of open cellular foam material with three dimensionally interconnected TiC/Ti struts was prepared by a two-step sponge-coating and high frequency induction heating process. The microstructure, composition and compression strength of the prepared TiC/Ti foam materials were characterized. It was confirmed that the incorporation of Ti into TiC resulted in an inter-bonded Ti-TiC-Ti layered structure in the struts, which enhanced the plasticity of the composite foam materials.

Photocatalytic Activities of TiO_2 Coated on Different Semiconductive SiC Foam Supports

Different semiconductive SiC foam supports were prepared by varying the sintering temperature and atmosphere, and with or without alkaline solution treatment and high temperature oxidation following a macromolecule pyrogenation combined with reaction bonding method. Nano-TiO2 particles were immobilized onto these SiC foam supports by a composite sol-gel method. The phase, surface morphology, the type of conduction and the photocatalytic activity of the TiO2-SiC composite photocatalysts were studied. The TiO2 coated on p-type Si-free SiC support showed the highest photocatalytic efficiency in degradation of 4- aminobenzenesulfonic acid （4-ABS） in aqueous solution as compared to that coated on n-type SiC support and p-type SiC supports with residual Si or Si02 on the surface. The result showed that the TiO2 coatings immobilized on p-type semiconductive SiC foam supports exhibited obviously higher photocatalytic activity in comparison to that coated on n-type SiC foam support. The p-n heterojunctions formed between the p-type SiC supports and n-type TiO2 coatings might be able to account for the better charge separation and transfer as well as the photocatalytic activity of the TiO2-SiC composite photocatalyst.

Nanoengineering Titania for High Rate Lithium Storage: A Review

Nanostructured titania have been intensively investigated as anode materials of Li-ion batteries for their excellent high rate performance. The size effects of TiO2 polymorphs （mainly rutile, anatase and TiO2-B） on their electrochemical performance and the latest efforts in nanoengineering titania anodes through enhancing their ionic or electronic transportation or both are reviewed in this work. We suppose that micron- or submicron- sized porous structures assembled by TiO2 nanoparticles, nanowires/nanotubes or nanosheets with a high percentage of exposing high reactive facets together with a conductive percolating network are ideal anodes not only for high rate lithium storage but also for high packing densities of the active materials.

Nitrogen and oxygen co-doped mesoporous carbon spheres as capacitive anode for high performance sodium-ion capacitors

The poor rate capability of battery-type anode is usually the bottleneck of the power-energy outputs of a hybrid alkaline metal ion capacitor.In this work,nitrogen and oxygen co-doped mesoporous carbon spheres with excellent rate performance and cycle stability are used as anode materials of sodium ion capacitors(SICs).The high N and O element doping levels as well as the amorphous and mesoporous structure have enabled prominent capacitive Na ion storage behavior,which in turn match well with the capacitive cathode in the hybrid device.Under optimum conditions,the SIC delivers a high energy density of 103.1 Wh kg^(-1)at a power density of 205.6 W kg^(-1).Even at a high power density of 7520 W kg^(-1),an energy density of 23.5 Wh kg^(-1)is still maintained.Moreover,a robust cycle stability with capacity retention of 84.6%after 2500 cycles at 1 A g^(-1)is maintained.Such excellent electrochemical performances convincingly demonstrate that the all-carbon based SICs with the highly capacitive N and O co-doped mesoporous carbon anode can be promising Na ion-based energy storage devices alternative to their Li ion-based counterparts.