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101.
102.
分析了低碳经济时代城镇发展的理念更新,指出高速城镇化进程中的误区,高耗能建筑的制约及城镇文化缺失对城镇更新带来的影响,并探讨低碳环保理念促进的城市更新策略,认为应对“过度”城镇化进行反思,在城镇建设改造过程中引入低碳理念并考虑聚落的文化复兴,提倡低碳的生活方式. 相似文献
103.
DIntroduction'Asonekindofimportantedbent,activatedcarbo11wasusedinlnoreandl11orefieIds.MagneticactivatedcarbonisbecoIninganinterestil1gsubjectfOrsoIvi11gseparationofactivatedcarbo11i11thisfieId.Mag11eticactivatedcarbol1wl1ichusemagneticreagentandacti-vatedcarbonasrawmateriaIl1asmal1yadva11tagesl'Isuchasgiantspecificsurface'weII-distributiOI1al1d
firmly-combined1nagl1e1ism.ButtI1eadsorptivemechanismoftl1emagneticreage11tol1activatedcarbonisstiIIunknown.X-rayphotoelectronpectroscopy(X… 相似文献
104.
105.
制备了邻菲口罗啉化学修饰碳糊电极,在含噻吩甲酰三氟丙酮的HAc-NaAc体系中,Co(Ⅱ)离子经化学富集在电极表面上形成三元络合物.采用2.5次微分伏安法测定痕量Co(Ⅱ)离子.Co(Ⅱ)浓度在8.0×10-9~7.0×10-7mol·L-1范围内与阳极溶出峰峰高成良好的线性关系,检出限达1.2×10-9mol·L-1.电极用于水样中钴的测定,结果令人满意. 相似文献
106.
以石油焦为活性炭原料,运用化学活化法制备了超级电容器用高比表面积活性炭。利用SEM和BET对实验制备的活性炭进行了分析和表征。以实验制备的活性炭为超级电容器电极材料,利用恒流充放电测试对其电容特性进行了研究。结果表明,实验研制的活性炭的比表面积为1674m2/g,中孔含量达到40%,在10mA/cm2的电流密度下其比容达到285F/g,而且基于实验研制的活性炭的超级电容器具有低内阻和良好的功率特性。 相似文献
107.
为了提升农林废弃物在储能领域的高附加值利用,该研究以杉木屑为原料,磷酸三聚氰胺为磷、氮源,基于冷冻NaOH/硫脲体系溶解木质原料中纤维素,通过一步热解制备氮、磷、硫共掺杂多孔炭,并考察活化温度、NaOH/杉木屑质量比和冷冻条件对多孔炭结构及电化学性能的影响。通过X射线光电子能谱(XPS, X-ray photoelectron spectroscop )和比表面积分析仪(BET,Brunauer-Emmett-Teller)研究多孔炭的表面结构和孔隙结构;采用循环伏安(CV,cyclic voltammetry)、恒流充放电(GCD,galvanostatic charge/discharge)和交流阻抗(EIS,electrochemical impedance spectroscopy)等测试手段表征其电化学性能。研究结果表明:随着活化温度和NaOH/杉木屑质量比的增加,多孔炭的表面积、全孔孔容和比电容呈现先增加后减小的趋势;冷冻条件和磷酸三聚氰胺的加入可以增加多孔炭的比表面积和全孔孔容,提升电化学性能。当活化温度900 ℃,NaOH/杉木屑质量比为1.2时,制备的氮、磷、硫共掺杂多孔炭的比表面积为2 048 m2/g,全孔孔容为1.655 cm3/g,介孔率为99.7%,氮、磷、硫的含量为3.41%、0.29%、1.40%。三电极体系下、6 mol/L KOH电解液中,当电流密度0.5 A/g时,比电容可达261 F/g。用NPS-900-1.2组装的对称超级电容器5 A/g电流密度条件下,比电容值为108 F/g,循环5 000次后库伦效率接近100%,电容保持率为92%。对称的超级电容器功率密度为248 W/kg时,能量密度可达17.2 Wh/kg。该研究为农林废弃物制备高性能超级电容器提供了参考依据。 相似文献
108.
C. Kechavarzi Q. Dawson P. B. Leeds-Harrison J. Szatyowicz & T. Gnatowski 《Soil Use and Management》2007,23(4):359-367
The rate of oxidation of peat soils is highly seasonal and varies with temperature and soil moisture content. Large variations in soil moisture content result in wet–dry cycles that can enhance peat degradation. Water‐table management plays a crucial role in controlling and damping the effect of these environmental factors. However, maintaining high ditch water levels in fields bounded by ditches does not guarantee a high field groundwater level. The effect of installing subsurface irrigation at different spacings on water table elevation was studied in a low‐lying peat grassland. The water table elevation data were compared against values predicted with a water balance model. In addition, greenhouse experiments were carried out on undisturbed soil core samples collected from the peat grassland as well as a low‐lying peatland under intensive arable faming to measure CO2 evolution under different water regimes. The field data from the peat grassland suggest that sub‐irrigation spacing as low as 10 m is necessary during summer periods to maintain groundwater levels similar to those in the ditches. Over the same period of observation, the difference in water level between the ditches and the non‐irrigated fields is as high as 0.7 m. Modelled outputs are in good correlation with the field observations, and demonstrate that simple water balance models can provide an effective tool to study the effect of water management practices and potential changes in subsurface conditions, climate and land use on water‐table levels. The measurement of CO2 emission from undisturbed peat soil columns shows that the rate of oxidation of soil organic matter from peat soils is highly seasonal and that drainage exacerbates the rate of peat mineralization. 相似文献
109.
《Land Degradation \u0026amp; Development》2017,28(1):83-94
The large scale conversion of extensive swidden agriculture to intensive market oriented production of maize in upland areas of South East Asia is a cause of environmental concern. This study investigates how intensive maize cultivation affects soil quality in an upland area of Northern Thailand by comparing commonly used indicators of soil quality in soils from maize fields used at various intensities. Relations between these indicators and concentration of permanganate oxidizable carbon (Pox‐C) – a low cost proxy for soil quality – are also examined. The extent, type and drivers of land use changes between 2002 and 2012 are investigated by classification of high resolution satellite images, interviews, participatory mapping and questionnaires. We document a widespread change from traditional swidden agriculture to intensive cultivation of maize that is mainly brought about by economcic and political drivers. We show that the concentration of Pox‐C in the top soil of the maize fields is closely related to common indicators of soil quality and to farmers' perceptions of soil quality. Most of the other soil quality indicators are negatively – albeit not significantly – related to intensity of maize cultivation. There is a strong negative correlation between intensity of maize cultivation and concentration of Pox‐C in the upper 5 cm of the soil where the Pox‐C concentration declines with a rate of 40 mg year under maize−1. We conclude that Pox‐C is a sensitive indicator of effects of land use intensity on the soil and a useful integrative measure of soil quality. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
110.