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1.
A lot of liquid-gas and liquid-gas-solid inclusions were found in Pharkant jadeitites, northwestern Myanmar and their characteristics, geological setting and porphyroclastic jadeites with inclusions in them were described in detail. The results analyzed by Raman spectrometer showed that the component of liquid-gas phase and solid phase (daughter minerals) in fluid inclusions is H2O + CH4 and jadeite separately. The results indicated that Pharkant jadeitites were crystallized from H2O + CH4 bearing jadeitic melt which may originate from mantle. The P-T conditions in which the jadeitites were crystallized were speculated to be T ＞650℃, P ＞1.5 GPa. 相似文献
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采用3种有机络合剂(葡萄糖、柠檬酸、酒石酸),通过溶胶-凝胶燃烧法制备钙钛矿结构的LaCoO3催化剂,并用X射线衍射(XRD)、扫描电子显微镜(SEM)、激光粒度分析仪、低温N2吸脱附等温线(BET)、程序升温还原(H2-TPR)以及程序升温脱附(O2-TPD)表征催化剂的结构,考察了3种络合剂合成的样品对甲烷催化燃烧反应的催化活性.结果表明,在600℃焙烧下,以葡萄糖为络合剂合成的LaCoO3催化剂呈现单一的钙钛矿结构,且颗粒粒度最小、分散度最高,具有较高的催化活性;以酒石酸为络合剂合成的催化剂以LaCoO3物相为主,并伴有La2O3和Co3O4物相,催化活性也较好;以柠檬酸为络合剂合成的样品以LaCoO3物相为主,伴有少量的La2O3和Co3O4物相,分散度最差,催化活性最低. 相似文献
3.
Dali Wang 《科学通报(英文版)》1999,44(13):1153-1153
Global CH4 emission may increase under CO2 enrichment condition, which is projected for the future. CO2 enrichment could affect CH4 emission in two ways: (i) Photosynthesis of plants that also include plants in rice paddies and natural wetlands will be stimulated under CO2 enrichment condition. CH4 emission rate may be increased due to the accumulation of more plant biomass, root exudes and soil organic matters. (ii) Combined with other global warming forces, CO2 enrichment may bring a change of atmospheric temperature and precipitation around the world. CH4 emission will also be changed with the variation of the area and distribution of rice paddies and natural wetlands. 相似文献
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利用三维激光粒子动态分析仪(LDV/APV系统)测量距离同轴流动燃烧装置Cup Burner出口不同位置的细水雾雾场特性(雾滴速度、雾滴粒径),利用Cup Burner系统地研究了细水雾抑制小尺度CH4/空气顺流非预混火焰,考察细水雾的粒径和雾滴质量分数对CH4/空气顺流非预混火焰结构的影响. 研究结果表明粒径为10～100 μm的细水雾能有效地抑制CH4/空气顺流非预混火焰,随着细水雾粒径减小或空气流中雾滴质量分数的增加,细水雾抑制熄灭CH4/空气顺流非预混火焰的能力增强. 细水雾抑制熄灭CH4/空气顺流非预混火焰的机理主要是气相吸热冷却和稀释氧气,在CH4/空气顺流非预混火焰的根部,气相吸热冷却起主导作用,而在火焰的上部稀释氧气起主导作用. 相似文献
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为了保证井下工作安全,设计了一种CH4实时在线监测系统。在分析了CH4气体特征吸收光谱的基础上,系统采用静态傅里叶变换干涉具及柱面镜等组成。通过线阵CCD采集静态干涉条纹,由光谱分析算法求出各个波长上的光强衰减度,最后通过比尔-朗伯定理、浓度程长积公式等反演CH4气体的浓度。仿真计算了光源光强、出射光强与瓦斯浓度的函数关系,验证了采用5 m W的DFB激光器,可以保证变化区域基本线性。系统采用分子筛过滤处理的方法,克服了目前光谱检测系统无法在井下复杂环境应用的难题。实验显示,在5 cm的气室中,经分子筛过滤保护的光谱探测系统可以在潮湿、粉尘的环境中稳定工作。采用傅里叶变换光谱分析法求解CH4浓度时,最小探测精度可达0.01%。 相似文献
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The areal extent of cold freshwater wetlands on the Qinghai-Tibet Plateau (QTP) is estimated at 0.133 × 106 km2, suggesting a significant methane potential. Methane fluxes from wet alpine meadows, peatlands,Hippuris vulgaris mires and secondary marshes were 43.18, 12.96, −0.28 and 45.90 mg · m−2 · d−1, respectively based on the transect flux studies at the Huashixia Permafrost Station (HPS) from July to August 1996. Average CH4 fluxes in the thaw season were extrapolated at 5.68 g · m−2 according to the areal percentage of wetland areas in the Huashixia region. The CH4 fluxes at four fixed sites, representative of similar ecosystems, ranged from −19.384–347.15 mg · m−2 · d−1, and the average CH4 fluxes varied from 6.54 to 71.97 mg · m−2 · d−1 at each site during the observation period from April to September 1997. The CH4 emissions at each site during the entire thaw season was estimated from 1.21 to 10.65 g · m−2, displaying strong spatial variations. Seasonal variations of CH4 fluxes also were observed at four sites: CH4 outbursts occurred upon the spring thaw in May and June, CH4 fluxes increased afterwards with rising soil temperatures. Episodic fluxes were observed in summer, which influenced the average CH4 fluxes considerably. Annual CH4 emissions from cold wetlands on the QTP were estimated at about 0.7–0.9 Tg based on the distribution of wetlands, representative CH4 fluxes, and number of thaw days. The centers of CH4 releasing were located in the sources of the Yangtze and Yellow rivers, and Zoigê Peatlands. 相似文献
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SONG Shuguang ZHANG Lifei NIU Yaoling SONG Biao ZHANG Guibing & WANG Qianjie . MOE Key Laboratory of Orogenic Belts Crustal Evolution De-partment of Geology Peking University Beijing China . Department of Geology University of Houston Houston TX USA . Beijing SHRIMP Centre Institute of Geology CAGS Beijing China Correspondence should be addressed to Zhang Lifei 《科学通报(英文版)》2004,49(8):848-852
TheNorthQilianMountainsattheboundarybe-tweenGansuandQinghaiProvincesareafamousCaledo-nianplatesuturezoneinthenorthwesternChina.Thissuturezoneis80to100kmwideandextendsintheNWdirectionparalleltotheNorthQaidamUHPbeltinthesouth[1,2].Itconsistspredominantlyofophiolite,island-arccomplexandhigh-presuremetamorphicrocks[38],andshowstypicalfeaturesofPacific-type[9](orB-type)sub-ductionzone.Spatially,thehigh-pressurerockscanbesubdividedintohigh-gradeblueschistbeltandlow-gradeblueschistbelt[5,6].Th… 相似文献
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H2S-rich gas in carbonate reservoirs is usually attributed to thermochemical sulfate reduction （TSR）. In this paper, thermal simulation experiments on the reaction system of CH4-MgSO4-H2O were carried out using autoclave at 425℃--525℃. The threshold temperature for initiating TSR is much lower than our previous studies （550℃）. Properties of the reaction products were analyzed by microcoulometry, gas-chromatography （GC）, Fourier transform-infrared spectrometry （FT-IR） and X-ray diffraction （XRD） methods. Thermodynamics and reaction kinetics of TSR processes were investigated on the basis of the experimental data. The results show that thermochemical reduction of magnesium sulfate with methane can proceed spontaneously to produce magnesium oxide, hydrogen sulfur, and carbon dioxide as the main products, and high temperature is thermodynamically favorable to the reaction. Ac- cording to the reaction model, the calculated activation energy of TSR is 101.894 kJ/mol, which is lower than that by most previous studies. Mg^2＋ may have played a role of catalytic action in the process of TSR. The elementary steps of TSR and reaction mechanism were discussed tentatively. The study can provide important information on the explanation of geochemical depth limit for natural gas and on the generation of high H2S gas in deep carbonates reservoirs. 相似文献
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A substrate with Ni/Ti/Si structure was used to grow vertical carbon nanotubes (CNTs) with a graphite fihn over CNT tops by thermal chemical vapor deposition with CH4 gas as carbon source. The carbon nanotubes and the substrate were characterized by a field emission scanning electron microscope for the morphologies, a transmission electron microscope for the microstructures, a Raman spectrograph for the ctystallinity, and an Auger electron spectrometer for the depth distribution of elements. The result shows that when the thickness ratio of Ni layer to Ti layer in substrate is about 1, a graphite film with relatively good quality can be formed on the CNT tops. 相似文献
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尖晶石锰酸锂和橄榄石磷酸铁锂离子电池是当前电动汽车用动力电池的主体,采用实验比较研究的方法,对比了两种动力电池正极材料电化学特性,研究了两种材料制备成动力电池的能量密度、功率密度、温度特性、循环寿命以及应用特性.结果表明:除低温性能和功率密度外,磷酸铁锂动力电池在其他方面的性能均优于锰酸锂动力电池. 相似文献
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Fluid and melt inclusions in mantle xenoliths are thought as direct samples to study mantle liquids. Here we apply Raman mi- crospectroscopy and microthermometry to fluid/melt inclusions in lherzolite xenoliths in Qiaoshan basalts, a Miocene volcano in Linqu, Shandong Province, eastern China. These inclusions include (1) early CO2 fluid inclusions, (2) early carbonate melt inclu-sions, (3) late CO2 fluid inclusions, and (4) late silicate melt inclusions. Among the early CO2 fluid inclusions, most consist of... 相似文献
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采用溶胶-凝胶法制备（CoFe2O4）x/（SiO2）1-x纳米复合材料. 利用X射线衍射（XRD）和振动样品磁强计（VSM）研究样品结构、 晶粒尺寸及磁性. 结果表明, 随SiO2含量增加, 样品的晶粒尺寸减小, 比饱和磁化强度和矫顽力降低. 相似文献
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以水热合成的钴掺杂Mn3O4作为模板,通过固相反应制备尖晶石LiMn2O4.XRD谱图和SEM照片显示制备的LiMn2O4具有岩石状结构并呈现良好的结晶性,同时Co的引入能够引起LiMn2O4晶格的收缩.作为锂离子电池正极材料,Co含量的增加能够提高循环稳定性但降低材料放电比容量,3％Co掺杂的LiMn2O4在0.5 ... 相似文献
16.
三聚氰胺热解产物的特性分析 总被引：1，自引：0，他引：1
以有机物三聚氰胺为初始原料, 在真空条件下使其热解（1 000 K）. 采用X射线衍射（XRD）、 透射电子显微镜（TEM）、 X射线光电子能谱(XPS)、 化学元素分析（EA）和傅里叶红外光谱(FT-IR) 分析样品的形貌、 成分和结构. 结果表明, 在真空条件下, 三聚氰胺全部分解, 分解产物为片层石墨相C3N4. 相似文献
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提出了一种简便的原位还原氧化法制备新型核壳复合材料Bi@Bi4O5Br2,并通过降解四环素研究了其在可见光下的光催化性能。结果表明,在氙灯照射90 min后,基于Bi@Bi4O5Br2的四环素(tetracycline,TC)去除率可达83.0%。该复合材料在LED灯(3 000 k、6 000 k)下也表现出很强的光催化性能,去除率分别达到55.0%和66.0%。光催化性能的增强可归因于将富铋策略和铋纳米粒子的局域表面等离子体共振(local surface plasmon resonance,LSPR)特性相结合的合理结构设计。这种核壳结构避免了Bi纳米粒子占据Bi4O5Br2的表面活性位点,并从另一个方向增加了复合材料的表面活性位点。此外,还通过X射线光电子能谱(X-ray photoelectron spectroscopy,XPS)和X射线衍射(X-ray diffractometer,XRD)表征验证了Bi@Bi4O5Br2的结构,并讨论了可能的形成机制。随后,通过自由基捕获实验确定了光催化过程中的主要活性物种,并阐明了可能的光催化机理。 相似文献
18.
YUAN Kun LU LingLing LIU YanZhi 《科学通报(英文版)》2008,53(9):1315-1323
The optimizations geometries and interaction energy corrected by BSSE of the complexes between C4H4Y （Y=O, S） and CHiLi have been calculated at the B3LYP/6-311＋＋G^＊＊ and MP2/6-311＋＋G^＊＊ levels. Three complexes were obtained. Abnormally, the calculations showed that all the C10--Li14 bond lengths increased obviously but the blue-shift of C10-Li14 stretching frequency occurred after formed complexes. The calculated binding energy with basis set super-position error （BSSE） and zero-point vibrational energy corrections of complexes I-III is -45.757, -35.700 and -39.107 kJ·mol^-1, respectively. The analyses on the combining interaction with the atom-in-molecules theory （AIM） also showed that a relatively strong lithium bond interaction presented in furan homologues C4H4Y-LiCH3 systems. Natural bond orbital theory （NBO） analysis has been performed, and the results revealed that the complex I is formed with n-σ type lithium bond interaction between C4H40 and LiCH3, complex II is formed with TT-s type lithium bond interaction between C4H4O and LiCH3, and complex III is formed with TT-s and n-s type lithium bond interactions between C4H4S and LiCH3, respectively. 相似文献
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Weidong Sun Xiachen Zhi Zicheng Peng Zhaorong Wang Ningjie Ge Xinhua Zhou 《科学通报(英文版)》1998,43(18):1575-1575
The osmium isotopic ratio of187Os/188Os ranging from 0.126 to 0.127 for the primitive upper mantle (PUM) is obtained according to the correlation between187Os/188Os and Al2O3 of mantle-derived xenoliths and orogenic peridotites, which consists with Allegre and Luck’s ALM value and similar to Yin’s nuggets uniform reservoir (NUR) value. It shows that the Os isotope ratio is lower than enstatite or ondinary chondrites, similar to carbonaceous chondrites (CV3). 相似文献
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Using （Ti（OC4H9）4） and metal chlorates as starting materials, CoFe2O4/TiO2 composite films were prepared by sol-gel method. The effects of heat treatment temperature and pH of the precursor on microstructure and magnetic properties were studied. The phase structure of the samples was examined by X-ray diffraction. The microstructure was examined by scanning electron microscope, atomic force microscope and polarized microscope. The magnetic property was measured by vibrating sample magnetometer. The results show that the crystals of different phases grow up independently. CoFe2O4 is uniformly embedded into the TiO2 matrix in the prepared composite films, and the growth of composite films is dependent on the heat treatment temperatures and PH of the precursor. The average size of CoFe2O4 crystal is 19 nm in Nanocomposite film prepared when the heat treatment temperature is 800℃ and the pH of the precursor is between 2 and 3. The magnetism of the composite films is enhanced as the heat treatment temperature increases. 相似文献