A modified ecological footprint analysis to a sub-national area:the case study of Zhejiang Province

在全球公顷和国家公顷的模型基础上,建立了省公顷生态足迹模型。采用2005年浙江省平均土地单位产量核算了浙江省各地的生态足迹,并与全球公顷和国家公顷法的结果进行了比较分析。从省公顷模型的结果可以看出,浙江省生态足迹达1.18 S-nHM2/人(省公顷,记为:S-nHM2),而生物承载力只有0.24 S-nHM2/人,生态赤字达0.94 S-nHM2/人,生态压力指数达4.91,是典型的生态赤字地区。另外,浙江省各地生态足迹空间差异较大,与全省平均水平相比,舟山和温州处于高强度生态压力,宁波、杭州、台州、金华和绍兴处于中强度生态压力,而丽水、衢州、湖州和嘉兴处于低强度生态压力。最后借助IPAT的分析,发现杭州、金华、嘉兴、湖州和衢州等地的万元gdP占用足迹不同程度地高于全省平均水平,并指出在一定条件下,应结合当地的经济发展程度合理提升资源利用效率的技术水平。The ecological footprint model on the basis of sub-national hectare was presented in this paper according to the ecological footprint concept and model on the basis of global hectare or national hectare.The ecological footprint and its composition of each city in Zhejiang Province were evaluated and analyzed by using the modified model and the actual yield per unit area of Zhejiang in 2005.The results were compared with those which were evaluated in global hectare or national hectare method,and the differences were analyzed among them.When using sub-national hectare as the evaluation criterion,the ecological footprint,the ecological capacity and the ecological deficit of Zhejiang Province in 2005 would be 1.18s-nhm2/cap,0.24s-nhm2/cap and 0.94s-nhm2/cap respectively,and the ecological pressure index was 4.91.The results suggest that Zhejiang Province is a representative area that has a large ecological deficit and high ecological pressure.They also suggested that there was a significant spatial difference according to the ecological footprint and its composition among the cities of Zhejiang.Compared with the average level of city ecological footprint in Zhejiang Province,Lishui,Quzhou,Huzhou and Jiaxing were in low ecological pressure states,and Ningbo,Hangzhou,Taizhou,Jinhua and Shaoxing were in middle ecological pressure states,while Zhoushan and Wenzhou were in high ecological pressure states.In the end,by applying IPAT,more eco-footprint demand of 104yuan GDP was found in Hangzhou,Jinhua,Jiaxing,Huzhou and Quzhou,which have a higher level than the average of Zhejiang,and suggestions were proposed that the level of local economic development must be considered to promote resource use efficiency.国家自然科学基金资助项目(40471055

Kinetics of Oxygen Reduction over Sm_(0.5)Sr_(0.5)CoO_3 Cathode

利用极化、交流阻抗技术考察了担载于La0.9Sr0.1Ga0.8Mg0.2O3(LSGM)电解质上的Sm0.5Sr0.5CoO3-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3(SSC-LSGMC5)复合阴极的氧还原反应动力学.在SSC-LSGMC5阴极氧还原反应的阻抗谱中可以观察到明显的两个半圆.高频环的电导与氧分压无关,低频环的电导正比于氧分压的0.5次方.并且低频环的氧分压级数随着反应温度的降低而减小,可能对应于吸附氧原子的扩散过程.SSC-LSGMC5极化曲线与经典的Butler-Volmer方程吻合.阴、阳极的电荷转移系数均为1左右,交换电流密度的氧分压级数为1/4,对应于电荷转移过程.实验结果显示SSC-LSGMC5上的氧还原反应机制随反应条件的不同而发生变化.The kinetics of oxygen reduction over Sm0.5Sr0.5CoO3 La0.8Sr0.2Ga0.8Mg0.15Co0.05O3(SSC LSGMC5) cathode was investigated using polarization and AC(alternating current) impedance. Two arcs were observed in the impedance spectra of SSC LSGMC5 at near equilibrium conditions. The conductivities of the high frequency arcs had no dependency on oxygen partial pressures (), and showed an activation energy about (1.0～ 1.1)× 102 kJ· mol- 1. The dependency of the conductivities of the low frequency arcs decreased from 0.6 to 0.4 with the decrease in temperature 1073～ 873 K, accordingly,the activation energies increased from 1.3× 102 to 1.6× 102 kJ· mol- 1 with the increase in (2× 104～ 1× 105 Pa). The high frequency arcs could be related to the transfer of oxygen ions across the electrode/electrolyte interface, while the low frequency arcs could correspond to the diffusion of oxygen atoms from the electrode surface to the three phase boundary. The polarization curves of SSC LSGMC5 agreed well with the Butler Volmer equation. The anodic and cathodic charge transfer coefficients were all about 1 and the dependency of the exchange current density was around 0.25, suggesting a rate determining step of charge transfer. The mechanism of oxygen reduction over SSC LSGMC5 depended strongly on the over potential and reaction temperature.福建省科技攻关计划重点项目(2003H046);; 留学回国人员基金资助~

Preparation and Characterization of High Performance Sm_(0.5)Sr_(0.5)CoO_3 Cathodes

用固相合成法合成了Sm0.5Sr0.5CoO3(SSC)中温固体氧化物燃料电池阴极材料.以La0.9Sr0.1Ga0.8Mg0.2O3为电解质,利用多种技术考察了不同温度(1 173～1 373 K)焙烧的SSC阴极,以及1 173 K焙烧、掺杂La0.8Sr0.2Ga0.8Mg0.15Co0.05O3(LSGMC5)或La0.8Sr0.2Ga0.5Mg0.09Co0.11O3(LSGMCII)高氧离子电导材料的复合SSC阴极.SEM的结果显示,随着电极焙烧温度的增加,电极的颗粒度增大,孔隙度减小;LSGMC5、LSGMCII的掺杂对电极微观结构影响不大.交流阻抗和极化实验的结果表明,SSC电极的活性随电极焙烧温度的增加而减小,电极的最佳焙烧温度在1 173 K左右;掺杂了LSGMC5或LSGMCII的复合SSC电极的活性以及稳定性显著高于SSC电极.Sm0.5Sr0.5CoO3(SSC) powders were prepared using solid-state reaction. The XRD pattern of SSC corresponded to a desired perovskite structure. SSC electrodes sintered at various temperatures (1 173-1 373 K) and SSC-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3 (SSC-LSGMC5), SSC-La0.8Sr0.2Ga0.8Mg0.09Co0.11O3 (SSC-LSGMC11) composite cathodes sintered at 1 173 K were studied using SEM, impedance spectroscopy, and DC(direct current) polarization. The electrodes studied were prepared on La0.9Sr0.1Ga0.8Mg0.2O3 electrolytes using screen-printing. The particle size of SSC electrodes increased with sintering temperatures, and the porosity decreased accordingly. The addition of LSGMC5 and LSGMC11 into SSC had no obvious effect on the microstructure of SSC electrodes. The results of AC (alternative current) impedance spectroscopy and DC polarization showed that the activity of SSC electrodes increased with decreasing sintering temperature, and the optimum sintering temperature for SSC electrodes was about 1 173 K. The addition of LSGMC5 or LSGMC11 into SSC improved both the activity and stability of SSC electrodes significantly.福建省科技攻关计划重点项目(2003H046);; 留学回国人员基金资助~

Important Measures to Upgrade Quality of Accounting Information——Comments on The Accounting Regulations for Business Enterprises

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低浓度有机磷萃取剂P204促进普通小球藻(Chlore11a vulgaris)生长的研究

本文以普通小球藻为实验对象,研究了有机磷萃取剂P204在低浓度

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轨道交通齿轮箱热平衡分析技术研究

轨道交通齿轮箱作为列车动力系统的关键部件，对列车的运行起到至关重要的作用。其中轨道交通齿轮箱的热平衡分析对保证齿轮箱的正常运行具有重要意义。以地铁齿轮传动系统为研究对象，应用热网络法建立关键部件的热平衡方程组，给出传动系统功率损失、热阻及对流换热系数的计算模型，并求解热平衡方程组的各节点温度。研究表明，该轨道交通齿轮箱的效率随着转速的升高而降低，转速升高，各节点的温度升高，齿轮啮合点处温度最高