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316L不锈钢表面Co2O4/MoS2纳米复合涂层的组织和析氢性能
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作者 李邵洋 何夏文 《材料保护》 CAS CSCD 北大核心 2019年第4期116-119,141,共5页
为获得廉价高效的电解水催化材料,通过水热法在316L不锈钢上制备Co2O4/MoS2纳米复合材料,采用扫描电镜(SEM)、X射线衍射仪(XRD)及透射电镜(TEM)对制备的试样进行测试,并采用极化曲线对其析氢效果进行了电化学表征。结果表明:MoS2纳米材... 为获得廉价高效的电解水催化材料,通过水热法在316L不锈钢上制备Co2O4/MoS2纳米复合材料,采用扫描电镜(SEM)、X射线衍射仪(XRD)及透射电镜(TEM)对制备的试样进行测试,并采用极化曲线对其析氢效果进行了电化学表征。结果表明:MoS2纳米材料在不锈钢表面分布均匀,具有花瓣状堆叠结构;Co2O4纳米材料呈垂直制备形态,表现出明显取向性排列趋势;Co2O4/316L纳米材料的XRD谱中除存在不锈钢对应的3个特征衍射峰之外,还形成了Co2O4对应的衍射峰,MoS2(002)晶面的特征峰表现为往低角度偏移的情况;Co2O4/MoS2纳米材料具有优异的析氢性能,且随着过电位增大电流密度明显上升,析氢反应速度更快;Co2O4与MoS2之间可通过协同作用提高析氢性能。 展开更多
关键词 316L不锈钢 水热法 co2o4纳米材料 MoS2纳米材料 co2o4/MoS2纳米复合材料 析氢反应
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泡沫镍载NiCO2O4电极的制备及其催化H2O2电氧化的性能
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作者 陈维伟 张飞凡 +5 位作者 杜佳亮 王毅 赵春林 朱凯 曹殿学 王贵领 《电化学》 CAS CSCD 北大核心 2020年第1期96-102,共7页
本文以水热法结合热处理法原位制备了泡沫镍载NiCo2O4纳米线电极,使用XRD、SEM和TEM对合成的NiCo2O4纳米线进行了表征,NiCo2O4纳米线直径约80 nm,长度约3~5μm.使用循环伏安和计时电流法测试了泡沫镍载NiCo2O4纳米线催化H2O2的电氧化性... 本文以水热法结合热处理法原位制备了泡沫镍载NiCo2O4纳米线电极,使用XRD、SEM和TEM对合成的NiCo2O4纳米线进行了表征,NiCo2O4纳米线直径约80 nm,长度约3~5μm.使用循环伏安和计时电流法测试了泡沫镍载NiCo2O4纳米线催化H2O2的电氧化性能,结果表明泡沫镍载NiCo2O4纳米线对H2O2电氧化有着优良的催化活性、稳定性和传质性能,在0.3 V电位下0.4 mol·L-1H2O2和2 mol·L-1NaOH溶液中氧化电流可达380 mA·cm-2. 展开更多
关键词 H2O2电氧化 水热法 泡沫镍 Nico2o4纳米线
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水热-固相热解法制备不同形貌的四氧化三钴纳米微粉 被引量:23
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作者 张卫民 孙思修 +1 位作者 俞海云 宋新宇 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2003年第12期2151-2154,共4页
以氨水和氢氧化钾水溶液为沉淀剂 ,利用沉淀 -固相热解法和中压水热 -固相热解法 ,制备了不同形貌的 Co3 O4纳米微粉 .在水热条件下 ,得到了立方和六角片状的 Co3 O4微粉 ,采用 XRD和 TEM等手段跟踪反应过程并表征产物 ,在此水热反应体... 以氨水和氢氧化钾水溶液为沉淀剂 ,利用沉淀 -固相热解法和中压水热 -固相热解法 ,制备了不同形貌的 Co3 O4纳米微粉 .在水热条件下 ,得到了立方和六角片状的 Co3 O4微粉 ,采用 XRD和 TEM等手段跟踪反应过程并表征产物 ,在此水热反应体系中影响产物 Co3 O4形貌的主要因素是 p H值和 NO-3 . 展开更多
关键词 水热-固相热解法 制备 四氧化三钴 纳米微粉 co2o4 表征 纳米材料
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Pt负载Li_2Co_2O_4的合成及其析氧性能研究 被引量:4
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作者 关扬 闫飞 +2 位作者 黄亮亮 林逍 王建强 《辽宁石油化工大学学报》 CAS 2018年第5期30-34,共5页
氢气作为清洁燃料在未来的能源版图中将发挥重要作用。电解水制氢反应只生成氢气和氧气,具有成本低、效率高、环境友好、安全性好等优点,而析氧反应是电解水制氢中的一个关键控速反应步骤。介绍了一种简单的Pt负载Li_2Co_2O_4合成方法,... 氢气作为清洁燃料在未来的能源版图中将发挥重要作用。电解水制氢反应只生成氢气和氧气,具有成本低、效率高、环境友好、安全性好等优点,而析氧反应是电解水制氢中的一个关键控速反应步骤。介绍了一种简单的Pt负载Li_2Co_2O_4合成方法,并对其析氧性能进行了表征。调控不同的Pt负载量(质量分数),比较对电催化性能的影响,最后得到Pt负载量5%为最优负载量。通过X射线衍射(XRD)、透射电子显微镜(TEM)对材料的结构进行表征,结果表明,得到了一种在保持催化剂的活性与耐久性的同时能够减少Pt消耗的高效催化剂。 展开更多
关键词 电解水制氢 Pt负载Li2co2o4 高效催化剂
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Ni掺杂Na_(1.6)Co_2O_4新型超级电容器电极材料的电性能研究 被引量:1
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作者 周岩 石常盛 +1 位作者 张蕾 汤宏伟 《材料导报》 EI CAS CSCD 北大核心 2014年第16期47-50,共4页
首次将掺杂镍离子的Na1.6Co2O4材料用作超级电容器的电极材料,并进行了XRD、SEM的表征和恒流充放电、循环伏安的电性能研究,发现掺杂3%(摩尔分数)Ni 2+的Na1.6Co2O4电极材料比纯的Na1.6Co2O4具有更优异的循环性能。
关键词 超级电容器 电极材料 Na1 6co2o4 掺杂 电化学性能
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施肥处理对春季冻融期灰漠土农田温室气体排放的影响 被引量:13
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作者 吕金岭 刘骅 +3 位作者 王西和 李太魁 寇长林 刘学军 《土壤学报》 CAS CSCD 北大核心 2018年第1期159-173,共15页
绿洲灰漠土冻融交替明显,但缺乏该时期气体通量及动态变化方面的研究。选取NPK(氮磷钾肥)、NPKS(0.9NPK+0.1秸秆氮)、NPKM(1/3NPK+2/3羊粪氮)和NPKM+(1.5倍NPKM)处理作为研究对象,利用静态箱气相色谱法开展2013—2014年春季冻融期温室... 绿洲灰漠土冻融交替明显,但缺乏该时期气体通量及动态变化方面的研究。选取NPK(氮磷钾肥)、NPKS(0.9NPK+0.1秸秆氮)、NPKM(1/3NPK+2/3羊粪氮)和NPKM+(1.5倍NPKM)处理作为研究对象,利用静态箱气相色谱法开展2013—2014年春季冻融期温室气体排放观测试验。结果显示,春季冻融期间,有机肥添加处理CO_2排放量较高,其中NPKM+和NPKM处理CO_2平均排放量分别为C 113 mg m^(-2) h^(-1)和85 mg m^(-2) h^(-1),其次为NPKS(72 mg m^(-2) h^(-1))、NPK(75 mg m^(-2) h^(-1))和CK(35 mg m^(-2) h^(-1))。同样,NPKM+和NPKM处理有相对更高的N_2O排放,春冻平均排放通量分别为N 73μg m^(-2) h^(-1)和42μg m^(-2) h^(-1),显著高于NPKS(22μg m^(-2) h^(-1))和NPK(17μg m^(-2) h^(-1))处理(p<0.05)。CH_4排放量相对较低,各处理无明显差异(p>0.05)。分析发现,N_2O在冻融期呈现先增加后急剧减少的趋势,CO_2变幅不明显。与全年总排放量相比,冻融期(27 d)N_2O的排放量占全年的9%~18%,CH_4冻融期间排放比重占全年排放量的6%~14%。所以,冻融交替期是灰漠土农田温室气体排放的相对高发时期,估算温室气体排放时应充分考虑。 展开更多
关键词 灰漠土 绿洲农田 施肥 N2O、CO2和CH4 冻融交替
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Co_3O_4/Al_2O_3催化剂对甲烷低温燃烧的催化性能 被引量:3
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作者 白延利 严河清 孙瑜 《武汉大学学报(理学版)》 CAS CSCD 北大核心 2005年第6期673-677,共5页
采用室温固相合成法制备了不同负载量的Co3O4/Al2O3系列催化剂,用X-射线衍射(XRD)技术对其物相结构进行了表征,并考察了负载量和焙烧温度对甲烷低温燃烧催化活性的影响.结果表明,该法制备的Co3O4/Al2O3系列催化剂具有较好的低温催化活性... 采用室温固相合成法制备了不同负载量的Co3O4/Al2O3系列催化剂,用X-射线衍射(XRD)技术对其物相结构进行了表征,并考察了负载量和焙烧温度对甲烷低温燃烧催化活性的影响.结果表明,该法制备的Co3O4/Al2O3系列催化剂具有较好的低温催化活性,且随Co3O4负载量的增加,催化剂的低温活性增强.综合考虑催化剂的催化活性和稳定性,400℃焙烧制备的Co3O4负载量为40%的Co3O4/Al2O3催化剂对甲烷低温催化燃烧有较好的催化性能. 展开更多
关键词 CO3O4 室温同相反应 甲烷氧化
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小兴安岭阔叶林沼泽土壤CO_2、CH_4和N_2O排放规律及其影响因子 被引量:20
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作者 牟长城 刘霞 +4 位作者 孙晓新 石兰英 冯登军 程伟 吴云霞 《生态学报》 CAS CSCD 北大核心 2010年第17期4598-4608,共11页
采用野外静态箱-气相色谱法,研究了小兴安岭典型阔叶林沼泽生长季节土壤CO2、CH4和N2O排放季节变化规律、源/汇功能及主要影响因子。结果表明:①苔草沼泽、毛赤杨沼泽和白桦沼泽生长季节土壤CO2、CH4、N2O排放分别集中在夏季、夏秋季、... 采用野外静态箱-气相色谱法,研究了小兴安岭典型阔叶林沼泽生长季节土壤CO2、CH4和N2O排放季节变化规律、源/汇功能及主要影响因子。结果表明:①苔草沼泽、毛赤杨沼泽和白桦沼泽生长季节土壤CO2、CH4、N2O排放分别集中在夏季、夏秋季、春夏季,平均排放通量依次为487.89、382.27、514.63 mg.m-2.h-1,1.88、1.03、0.04 mg.m-2.h-1,3.70、58.61、11.73μg.m-2.h-1。②三者生长季节土壤CO2排放通量与气温和0-20 cm土壤温度均呈显著正相关;苔草沼泽CH4排放通量与30-40cm土壤温度呈显著正相关,毛赤杨沼泽CH4排放通量与地表温度呈显著负相关;白桦沼泽N2O排放通量与地表温度呈显著正相关。苔草沼泽N2O排放与水位呈显著负相关;毛赤杨沼泽CH4排放与水位呈显著正相关;白桦沼泽CO2排放与水位呈显著负相关。③三者生长季节土壤均为CO2、CH4、N2O排放源(17.56、13.76、18.53 t.hm-2;67.54、37.05、1.30 kg.hm-2;0.13、2.11、0.42 kg.hm-2),三者CO2排放量相近(5.5%-21.6%);苔草沼泽为CH4的强排放源,毛赤杨沼泽为中排放源,白桦沼泽为弱排放源;毛赤杨沼泽为N2O的强排放源,白桦沼泽为中排放源,苔草沼泽为弱排放源。 展开更多
关键词 小兴安岭 阔叶林沼泽 CO2、CH4和N2O 季节变化规律
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Fluxes of soil carbon dioxide,nitrous oxide and firedamp in broad-leaved/Korean pine forest 被引量:3
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作者 肖冬梅 王淼 +2 位作者 王跃思 姬兰柱 韩世杰 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第2期107-112,i001,i002,共8页
To understand influence of litters on the emission/absorption of CO2, N2O and CH4 in broadleaved/Korean pine forest in Changbai Mountain, fluxes of soil CO2, N2O and CH4 were measured by closed static chamber techniqu... To understand influence of litters on the emission/absorption of CO2, N2O and CH4 in broadleaved/Korean pine forest in Changbai Mountain, fluxes of soil CO2, N2O and CH4 were measured by closed static chamber technique, from Sept 3, 2002 to Oct 30, 2003 in two types of soil ecosystems, of which one was covered with litters on the surface soil, and the other had no litters. The results showed that litters had significant influences on CO2, N2O and CH4 fluxes (p<0.05). Their diurnal change patterns of plot with litters and litter-free plot were similar, and they all showed emission/absorption peak at 18:00. The diurnal change fluxes of CO2 and N2O of plot with litters were significantly higher than those of the litter-free plot, while the diurnal flux of CH4 of plot with litters was lower than that of litter-free plot. The fluxes of CO2, N2O, and CH4 showed the similar seasonal patternsfor both plots. The fluxes of CO2, CH4 showed their peak fluxes in June, but the fluxes of N2O showed its peak emissions in August. The annual fluxes of CO2 and N2O of plot with litters were significantly higher than those of the litter-free plot, while the annual flux of CH4 of plot with litters was lower than that of litter-free plot. Keywords Flux - CO2, N2O and CH4 - Seasonal variation - Diurnal variation CLC number S718.5 Document code A Foundation item: The study was supported by innovation research project of Institute of Appiied Ecology, Chinese Academy of Sciences (SCXZD0101-02) and National Natural Science Foundation of China (30271068)Bigraphy: XIAO Dong-mei (1979-), female, master of Institute of Applied Ecology. Chinese Academy of Sciences, Shenyang 110016. P. R. China.Responsible editor: Song Funan 展开更多
关键词 FLUX CO2 N2O and CH4 Seasonal variation Diurnal variation
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Oxidation of diesel soot on binary oxide Cu Cr(Co)-based monoliths 被引量:2
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作者 Sergiy O.Soloviev Andriy Y.Kapran Yaroslava P.Kurylets 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2015年第2期171-177,共7页
Binary oxide systems(Cu Cr2O4, Cu Co2O4), deposited onto cordierite monoliths of honeycomb structure with a second support(finely dispersed Al2O3), were prepared as filters for catalytic combustion of diesel soot ... Binary oxide systems(Cu Cr2O4, Cu Co2O4), deposited onto cordierite monoliths of honeycomb structure with a second support(finely dispersed Al2O3), were prepared as filters for catalytic combustion of diesel soot using internal combustion engine’s gas exhausts(O2, NOx, H2 O, CO2) and O3 as oxidizing agents. It is shown that the second support increases soot capacity of aforementioned filters, and causes dispersion of the particles of spinel phases as active components enhancing thereby catalyst activity and selectivity of soot combustion to CO2. Oxidants used can be arranged with reference to decreasing their activity in a following series: O3 NO2〉 H2 O 〉 NO 〉 O2〉 CO2. Ozone proved to be the most efficient oxidizing agent: the diesel soot combustion by O3 occurs intensively(in the presence of copper chromite based catalyst) even at closing to ambient temperatures.Results obtained give a basis for the conclusion that using a catalytic coating on soot filters in the form of aforementioned binary oxide systems and ozone as the initiator of the oxidation processes is a promising approach in solving the problem of comprehensive purification of automotive exhaust gases at relatively low temperatures, known as the "cold start" problem. 展开更多
关键词 Catalyzed diesel particulate filters Cu Cr2O4 Cu co2o4catalytic coatings Cordierite monoliths Second support Oxidizing agents OZONE
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Preparation of nanostructured mesoporous Ni Co_2O_4 and its electrocatalytic activities for water oxidation 被引量:1
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作者 Genyan Hao Wei Wang +2 位作者 Guofeng Gao Qiang Zhao Jinping Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2015年第3期271-277,共7页
Nanostructured mesoporous Ni Co2O4,Co3O4 and Ni O spinel oxides were prepared through the hydroxide coprecipitation method using EG(ethylene glycol) as solvent without any template.The Ni Co2O4 powders were analyzed... Nanostructured mesoporous Ni Co2O4,Co3O4 and Ni O spinel oxides were prepared through the hydroxide coprecipitation method using EG(ethylene glycol) as solvent without any template.The Ni Co2O4 powders were analyzed by TGA,XRD,N2adsorption-desorption,SEM and EDS.And the electrocatalytic properties of Ni Co2O4/Ti,Co3O4/Ti and Ni O/Ti electrodes for oxygen evolution in 0.1 mol/L KOH(p H = 13)were tested by cyclic voltammetry,Tafel curves and electrolysis.The result shows that Ni Co2O4/Ti electrode has higher electrocatalytic activity in oxygen evolution reaction than Co3O4/Ti and NiO/Ti electrodes.Ni Co2O4/Ti electrode prepared at 350°C has the highest apparent current density and the highest true current density.The Tafel slope of Ni Co2O4/Ti electrode prepared at 350°C is 68.49 m V/dec. 展开更多
关键词 water splitting NANOSTRUCTURE Ni co2o4 electrocatalytic properties
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不同经营方式及生境对大兴安岭高纬度林区生长盛季森林土壤CO_2、CH_4、N_2O通量的影响 被引量:4
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作者 任乐 马秀枝 范雪松 《生态环境学报》 CSCD 北大核心 2015年第3期378-386,共9页
为了确定不同森林经营利用方式(原始林、皆伐林、渐伐林)及不同生境(有林地、无林地、湿地)对于森林土壤-大气主要温室气体通量的影响,于2013年生长盛季(7─8月),在内蒙古大兴安岭兴安落叶松(Larix gmelinii)林区选取了16块样地,采用静... 为了确定不同森林经营利用方式(原始林、皆伐林、渐伐林)及不同生境(有林地、无林地、湿地)对于森林土壤-大气主要温室气体通量的影响,于2013年生长盛季(7─8月),在内蒙古大兴安岭兴安落叶松(Larix gmelinii)林区选取了16块样地,采用静态箱/气相色谱法进行了土壤-大气温室气体通量的原位观测。气体监测的同时,测定了土壤湿度和各层土壤温度以及各样地土壤的物理、化学性质。实验结果表明:大兴安岭兴安落叶松林区生长盛季CH4通量平均值为C(-133.6±62.3)μg·m-2·h-1。沼泽湿地(PD2和PD7)CH4表现为释放,CH4通量平均值为C(130.0±41.0)μg·m-2·h-1,其它14个样地土壤CH4为吸收,吸收通量变化范围为C(-242.0^-42.6)μg·m-2·h-1,变异系数为47%。所有样地CO2的地-气通量变化范围是C(94.9~1164.0)μg·m-2·h-1,平均值为C(671.3±324.3)μg·m-2·h-1,变异系数是48%。所有样地N2O通量的范围是N(1.2~21.6)μg·m-2·h-1,平均值为N(7.3±6.1)μg·m-2·h-1,变异系数为84%。通过数据分析显示,大兴安岭林区生长盛季不同经营方式及不同生境对森林土壤-大气CH4、CO2、N2O通量均无显著相关性。CH4通量与土壤各层温度及各层湿度并未发现有显著相关性,仅显示CH4通量与土壤有机质(SOC)呈正相关关系、土壤全氮(TN)呈负相关关系;CO2通量与土壤5 cm处温度显著相关(P=0.042 3),与土壤0 cm及10 cm处温度无显著相关性,CO2通量与土壤各层温度呈正相关关系,与腐殖质层、0~10 cm以及10~20 cm土壤湿度呈负相关关系,与SOC、TN呈负相关关系;N2O通量与土壤各层温度、湿度及SOC均呈正相关关系,与TN呈负相关关系。 展开更多
关键词 兴安落叶松林 CO2、CH4、N2O 不同经营方式 不同生境
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一种新颖的具有螺旋孔道的磷酸钴Co_2(HPO_4)_2·H_2O的水热合成与晶体结构 被引量:1
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作者 曾庆新 陈连山 +2 位作者 李亚丰 杨国昱 徐吉庆 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2003年第1期31-33,共3页
A new Co 2(HPO 4) 2·H 2O has been hydrothermally synthesized firstly. Single crystal X-ray analysis indicates that this compound crystallizes in a hexagonal system, space group P6 5 with a=1.048 31(15) nm, b=1.04... A new Co 2(HPO 4) 2·H 2O has been hydrothermally synthesized firstly. Single crystal X-ray analysis indicates that this compound crystallizes in a hexagonal system, space group P6 5 with a=1.048 31(15) nm, b=1.048 31(15) nm, c=1.496 3(3) nm, α=90°, β=90°, γ=120°, V= 1.424 1(4) nm 3, μ=3.849 mm -1, Z=6, F(000)=960, D c=2.294 g/cm 3, R=0.072 1, wR= 0.212 1, S=1.182, Δρ max=1.671×10 3 e·nm -3 and (Δρ) min=-1.210×10 3 e·nm -3. Co 2(HPO 4) 2·H 2O is characterized by 1D 12-ring helical channels. Tetrahedral primary structure-building units of CoO 4 and PO 4 indicates the title compound has a zeotype framework. 展开更多
关键词 螺旋孔道 Co2(HPO4)2·H2O 水热合成 磷酸钴 晶体结构
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N_2O/C_2H_4/CO_2预混气体火焰传播及爆炸特性的试验研究 被引量:6
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作者 曾祥敏 张玉刚 +4 位作者 蒋榕培 李智鹏 徐森 李玉艳 刘大斌 《火炸药学报》 EI CAS CSCD 北大核心 2018年第5期501-505,共5页
为了研究N_2O/C_2H_4/CO_2预混气体的火焰传播及爆炸特性,采用内含螺旋加速环,长200cm、内径1.5cm的有机玻璃管装置,用电阻丝点火的方式进行预混气体的燃烧爆炸试验;利用压力传感器测量爆炸压力和爆轰速度,并利用高速摄影仪测量燃烧时... 为了研究N_2O/C_2H_4/CO_2预混气体的火焰传播及爆炸特性,采用内含螺旋加速环,长200cm、内径1.5cm的有机玻璃管装置,用电阻丝点火的方式进行预混气体的燃烧爆炸试验;利用压力传感器测量爆炸压力和爆轰速度,并利用高速摄影仪测量燃烧时的火焰速度;采用C-J理论计算了预混气体的理论爆速和理论爆压。结果表明,预混气体在燃烧管内快速燃烧,火焰呈对称的Tulip结构,最大火焰速度为2 235.2m/s;除距离点火10cm处外,其余7个传感器压力陡然上升,均出现冲击波,其中100cm处的压力峰值最大为4.66MPa,冲击波的最大速度为2 247m/s;C-J理论爆速为2 366.75m/s,理论爆压为4.26MPa,最大火焰速度和最大冲击波速度与C-J理论爆轰速度的偏差分别为5.54%和5.06%,试验结果与理论值基本一致。 展开更多
关键词 氧化亚氮 燃烧 火焰传播 爆燃转爆轰 爆轰波 N2O/C2H4/CO2 预混气体 N2O基推进剂
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低温燃烧技术合成钴掺杂镓酸镁锌复合尖晶石材料 被引量:2
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作者 杜吉勇 肖仁辉 李艳 《山东科学》 CAS 2014年第3期87-92,共6页
采用Mg(NO3)2·4H2O,Ga(NO3)3·6H2O,Zn(NO3)2·6H2O,CO(NH2)2,NH4NO3及Co(NO3)2·6H2O等为原料,于500℃利用低温燃烧技术成功获得了一系列钴掺杂镓酸镁锌复合尖晶石材料。采用X-射线衍射仪(XRD)、透射电镜(TEM)、F-450... 采用Mg(NO3)2·4H2O,Ga(NO3)3·6H2O,Zn(NO3)2·6H2O,CO(NH2)2,NH4NO3及Co(NO3)2·6H2O等为原料,于500℃利用低温燃烧技术成功获得了一系列钴掺杂镓酸镁锌复合尖晶石材料。采用X-射线衍射仪(XRD)、透射电镜(TEM)、F-4500型荧光分光光度计对样品进行分析表征。结果表明,所得产品不是MgGa2O4和ZnGa2O4的简单混合物,而是一种新型的固溶体材料。ZnxMg1-xGa2O4:Co2+(0≤x≤1.0)晶体的晶格常数与掺杂比例x之间存在比较好的线性关系。合成的晶体结晶度高,排列较规整。发射光谱的形状和位置分析表明,可见光区670 nm附近的强发射峰源于四面体位中Co2+的4T1(4P)→4A2(4F)能级跃迁;近红外区的弱发射峰源于四面体位中Co2+的4T1(4P)→4T2(4F)能级跃迁。 展开更多
关键词 燃烧技术 ZnxMg1-xGa2O4∶Co2+ 纳米晶体
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氮硫输入对短叶茳芏枯落物温室气体产生的影响 被引量:2
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作者 张美颖 曾从盛 +1 位作者 胡伟芳 张林海 《亚热带资源与环境学报》 2018年第4期25-33,共9页
探究氮(N)、硫(S)输入对枯落物温室气体产生速率的影响,对进一步认识河口湿地生物地球化学循环过程和维护区域生态安全具有重要的理论与实践意义。选取闽江河口湿地典型土著植物短叶茳芏(Cyperus malaccensis Lam. submonophyllus (Vahl... 探究氮(N)、硫(S)输入对枯落物温室气体产生速率的影响,对进一步认识河口湿地生物地球化学循环过程和维护区域生态安全具有重要的理论与实践意义。选取闽江河口湿地典型土著植物短叶茳芏(Cyperus malaccensis Lam. submonophyllus (Vahl) T. Koyama)作为研究对象,通过室内模拟实验,探讨不同浓度的N与S输入中N (MN,18. 2 g N m^(-2)·a^(-1))、高N(HN,27. 3 g N m^(-2)·a^(-1))、中S (MS,15. 8 g S m^(-2)·a^(-1))、高S (HS,23. 7 g S m^(-2)·a^(-1))、中N+S (MNS,18. 2 g N m^(-2)·a^(-1),15. 8 g S m^(-2)·a^(-1))和高N+S (HNS,27. 3 g N m^(-2)·a^(-1),23. 7 g S m^(-2)·a^(-1))对短叶茳芏枯落物温室气体排放的短期影响。结果表明:(1)与对照组相比,单一N、S和N+S复合输入均对闽江河口短叶茳芏枯落物CO2产生有显著促进作用,分别增加了36. 5%、43. 5%和65. 5%(P <0. 05)。(2)与对照组相比,单一N、S输入对CH4产生无显著影响(P> 0. 05);单一N输入和N+S复合输入下的CH4产生速率均呈"V"型变化趋势:前4 d产生速率下降,后3 d产生速率上升。(3)与对照相比,单一N、S输入及NS复合输入均显著促进N2O排放,分别增加了189. 5%、493. 5%和814%(P <0. 05),N2O产生速率在各处理下均呈"倒V型"变化趋势:前2 d产生速率上升,后5 d产生速率下降。(4)短期内,N、S以及N+S复合输入对短叶茳芏枯落物的全球增温潜势有促进作用。 展开更多
关键词 氮输入 硫输入 短叶茳芏枯落物 CO2、CH4、N2O气体 闽江河口湿地
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南极大气CO_2、CH_4和N_2O本底趋势特征分析 被引量:1
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作者 孙述蒙 郑向东 卞林根 《极地研究》 CAS CSCD 2017年第1期56-65,共10页
对南极大气温室气体CO_2(含δ^(13)C-CO_2和δ^(18)O-CO_2)、CH_4和N_2O长期测值进行比较分析。结果表明,南极是全球大气温室气体浓度(CO_2稳定同位素丰度值)随纬度分布变化中的最低(高)区域。南极大气温室气体浓度值变化趋势、年增长... 对南极大气温室气体CO_2(含δ^(13)C-CO_2和δ^(18)O-CO_2)、CH_4和N_2O长期测值进行比较分析。结果表明,南极是全球大气温室气体浓度(CO_2稳定同位素丰度值)随纬度分布变化中的最低(高)区域。南极大气温室气体浓度值变化趋势、年增长率与全球整体上一致,但在具体数值上存在差异。南极CO_2平均年增长率(1958—2014年)为(1.43±0.59)mg·L^(–1)·a^(–1),低于同期赤道(1.51±0.72)mg·L^(–1)·a^(–1),但1980—2014年和2000—2014年年增长率均高于南半球中纬度地区。δ^(13)C-CO_2和δ^(18)O-CO_2丰度趋势揭示了化石燃料排放和全球尺度过程对CO_2的影响,但南极是受影响最小的区域。1983—2014年南极CH_4平均增长率为(6.2±4.9)μg·L^(–1)·a^(–1),低于北半球中纬度(6.5±5.6)μg·L^(–1)·a^(–1)而高于赤道(5.6±5.3)μg·L^(–1)·a^(–1)和南半球中纬度(6.1±4.9)μg·L^(–1)·a^(–1),这与CH_4人为排放增强主要在北半球中纬度地区而显著被OH氧化在赤道和中纬度地区的事实是吻合的。南极N_2O平均年增长率为(0.87±0.15)μg·L^(–1)·a^(–1)(2005—2013年),与南半球中纬度地区接近但低于北半球而高于赤道地区。 展开更多
关键词 南极 温室气体(CO2、CH4、N2O)年增速 比较分析
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Fluxes of CO_2,CH_4 and N_2O from alpine grassland in the Tibetan Plateau 被引量:13
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作者 PEI Zhiyong,OUYANG Hua,ZHOU Caiping,XU Xingliang(Inst. of Geographic Science s and Natural Resources Research, CAS, Beijing 100101, China) 《Journal of Geographical Sciences》 SCIE CSCD 2003年第1期27-34,共8页
Using stat ic chamber technique, fluxes of CO 2 , CH 4 and N 2 O were measured in the alpine grassland area from July 2000 to July 2001, d eterminations of mean fluxes showed that CO 2 and N 2 O were gene rally releas... Using stat ic chamber technique, fluxes of CO 2 , CH 4 and N 2 O were measured in the alpine grassland area from July 2000 to July 2001, d eterminations of mean fluxes showed that CO 2 and N 2 O were gene rally released from the soil, while the alpine grassland accounted for a weak CH 4 sink. Fluxes of CO 2 , CH 4 and N 2 O ranged widely. The highest CO 2 emission occurred in August, whereas a lmost 90% of the whole year emission occurred in the growing season. But the variations of CH 4 and N 2 O fluxes did not show any clear patterns over the one-year-experim ent. During a daily variation, the maximum CO 2 emission occurred at 16:00, and then decreased to the minimum emi ssion in the early morning. Daily pattern analyses indicated that the variation in CO 2 fluxes was positively related to air temperatures (R 2 =0.73) and soil temperatures at a depth of 5 cm (R 2 =0.86), whereas daily variations in CH 4 and N 2 O fluxes were poorly explained by soil temperatures and climatic va riables. CO 2 emissions in this area were much lower than other grasslands in plain areas . 展开更多
关键词 CO 2 CH 4 and N 2 O FLUX alpine grassland Tibetan Plateau
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Molecular simulation of the CH_4/CO_2/ H_2O adsorption onto the molecular structure of coal 被引量:18
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作者 XIANG JianHua ZENG FanGui +2 位作者 LIANG HuZhen LI Bin SONG XiaoXia 《Science China Earth Sciences》 SCIE EI CAS 2014年第8期1749-1759,共11页
Clarification of the molecular mechanism underlying the interaction of coal with CH4, CO2, and H2 O molecules is the basis for an in-depth understanding of the states of fluid in coal and fluid-induced coal swelling/c... Clarification of the molecular mechanism underlying the interaction of coal with CH4, CO2, and H2 O molecules is the basis for an in-depth understanding of the states of fluid in coal and fluid-induced coal swelling/contraction. In terms of instrumental analysis, molecular simulation technology based on molecular mechanics/dynamics and quantum chemistry is a powerful tool for revealing the relationship between the structure and properties of a substance and understanding the interaction mechanisms of physical-chemical systems. In this study, the giant canonical ensemble Monte Carlo(GCMC) and molecular dynamics(MD) methods were applied to investigate the adsorption behavior of a Yanzhou coal model(C222H185N3O17S5). We explored the adsorption amounts of CH4, CO2, and H2 O onto Yanzhou coal, the adsorption conformation, and the impact of oxygen-containing functional groups. Furthermore, we revealed the different adsorption mechanisms of the three substances using isosteric heat of adsorption and energy change data.(1) The adsorption isotherms of the mono-component CH4, CO2, and H2 O were consistent with the Langmuir model, and their adsorption amounts showed an order of CH4CO2〉CH4. In addition, at higher temperatures, the isosteric heat of adsorption decreased; pressure had no significant effect on the heat of adsorption.(3) CH4 molecules displayed an aggregated distribution in the pores, whereas CO2 molecules were cross arranged in pairs. Regarding H2 O molecules, under the influence of hydrogen bonds, the O atom pointed to surrounding H2 O molecules or the H atoms of coal molecules in a regular pattern. The intermolecular distances of the three substances were 0.421, 0.553, and 0.290 nm, respectively. The radial distribution function(RDF) analysis showed that H2 O molecules were arranged in the most compact fashion, forming a tight molecular layer.(4) H2 O molecules showed a significantly stratified distribution around oxygen-containing functional groups on the coal surface, and the bonding strength showed a descending order of hydroxyl〉 carboxyl〉carbonyl. In contrast, CO2 and CH4 showed only slightly stratified distributions.(5) After the adsorption of CH4, CO2, and H2 O, the total energy, the energy of valence electrons, and the non-bonding interaction of the system in the Yanzhou coal model all decreased. The results regarding the decrease in the total energy of the system indicated an order of H2O〉CO2〉CH4 in terms of the adsorption priority of the Yanzhou coal model. The results regarding the decrease in the energy of valence electrons showed that under certain geological conditions, a pressure-induced “coal strain” could lead to a structural rearrangement during the interaction of coal with fluid to form a more stable conformation, which might be the molecular mechanism of coal swelling resulting from the interaction between fluid and coal. An analysis of the contribution of Van der Waals forces, electrostatic interactions and hydrogen bonds to the decrease in non-bonding interactions revealed the mechanism underlying the interactions between coal molecules and the three substances. The interaction between coal molecules and CH4 consisted of typical physical adsorption, whereas that between coal molecules and CO2 consisted mainly of physical adsorption combined with weak chemical adsorption. The interaction between coal molecules and H2 O is physical and chemical. 展开更多
关键词 CH4/CO2/H2O isosteric heat of adsorption adsorption isotherm radial distribution function Yanzhou coal model
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Greenhouse gas emissions during co-composting of cattle feedlot manure with construction and demolition (C&D) waste
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作者 Xiying Hao Francis J. Larney 《Frontiers of Environmental Science & Engineering》 SCIE EI CAS CSCD 2017年第3期141-152,共12页
Manure management strategies should reflect current animal feeding practices and encourage recycling of organic waste to help protect our environment. This research investigated greenhouse gas (GHG) emissions during... Manure management strategies should reflect current animal feeding practices and encourage recycling of organic waste to help protect our environment. This research investigated greenhouse gas (GHG) emissions during cattle manure stockpiling or composting with and without construction and demolition (C&D) waste. Manure was collected from cattle fed a typical finishing diet (CK manure) and from cattle on diets which included 30% dried distillers grains with solubles (DG manure). The CK and DG manures were co-composted with (4:1) C&D waste (treatments: CK CD, DG CD), composted alone (treatments: CK and DG) in 13 m3 bins or stockpiled without C&D ~vaste (treatments: CK ST and DGST) for 99 days. Manure type (CK vs. DG manure) had no effect on GHG emissions-over the 99 day manure composting or stockpiling. Composting with C&D waste 2 produced similar CO2 emissions, about double that from manure stockpthng (7.9 kgC.m^-2). In contrast, CH4 emissions were reduced by the inclusion of C&D waste (64 gC.m^-1 with C&D vs. 244 gC.m 2 without C&D) while the manure stockpile emitted the greatest amount of CH4 (464 gC. m 2). Additionally, only 0.48% of C was emitted in CH4 form with C&D waste, compared to 1.68% when composting without C&D waste and 7.00% when cattle manure was stockpiled. The N2O emissions (12.4 to 18.0 gN.m ) were similar across all treatments. The lower CH4 emissions with C&D waste are beneficial in reducing overall GHG emissions from manure composting, while reducing the amount of material entering landfills. 展开更多
关键词 Livestock manuregreenhouse gas fluxstraw bale compost binN2O CH4 CO2
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