Iron in the NEEM ice core relative to Asian loess records over the last glacial–interglacial cycle

Mineral dust can indirectly affect the climate by supplying bioavailable iron (Fe) to the ocean. Here, we present the records of dissolved Fe (DFe) and total Fe (TDFe) in North Greenland Eemian Ice Drilling (NEEM) ice core over the past 110 kyr BP. The Fe records are significantly negatively correlated with the carbon-dioxide (CO₂) concentrations during cold periods. The results suggest that the changes in Fe fluxes over the past 110 kyr BP in the NEEM ice core are consistent with those in Chinese loess records because the mineral-dust distribution is controlled by the East Asian deserts. Furthermore, the variations in the dust input on a global scale are most likely driven by changes in solar radiation during the last glacial–interglacial cycle in response to Earth''s orbital cycles. In the last glacial–interglacial cycle, the DFe/TDFe ratios were higher during the warm periods (following the post-Industrial Revolution and during the Holocene and last interglacial period) than during the main cold period (i.e. the last glacial maximum (LGM)), indicating that the aeolian input of iron and the iron fertilization effect on the oceans have a non-linear relationship during different periods. Although the burning of biomass aerosols has released large amounts of DFe since the Industrial Revolution, no significant responses are observed in the DFe and TDFe variations during this period, indicating that severe anthropogenic contamination has no significant effect on the DFe (TDFe) release in the NEEM ice core.     

我国能源结构演进及CO2排放影响因素分析

全球气候变暖对地球生态和人类生活构成严重的威胁,成为各国政府和人民共同关注的问题。中国作为世界上最大的发展中国家,如何找到一条适合中国自己的低碳经济发展道路,是当今面临的重要问题。首先由中国50余年的能源利用情况为切入点,描述了我国一次能源结构演进状况,在定性与定量相结合的基础上系统分析了二氧化碳排放量影响因素对我国二氧化碳排放量的影响。最后得出,我国近年来的二氧化碳排放量的增长主要是由于我国经济的高速增长引起的,而能源消费结构和产业结构的改善和能源效率水平的提高可以在很大程度上降低由经济增长带来的碳排放。     

球形SnO2微晶水热法制备与表征

采用SnCl4.5H2O为原料,NaOH作沉淀剂,通过一个简单的水热过程制得球形SnO2微晶。样品的XRD和TEM表征结果表明反应温度、水热时间、不同的碱源和软模板对产物的形貌和尺度有一定的影响,球形SnO2微晶的形成机理可能是一个水热过程中的自组装行为。     

Soft template synthesis of high selectivity mesoporous SnO2 gas sensors

Mesoporous SnO2 was synthesized using cetyltrimethyl ammonium bromide （CTAB） as supermolecule-template by hydrothermal method followed by calcining under different temperature in air. X-ray diffraction analysis （XRD） and transmission electron microscopy （TEM） techniques were used to characterize the structure of mesoporous SnO2. The results indicated that the gas sensors prepared by using mesoporous SnO2 after calcination at 400 ℃ showed quick response and recovery to ethanol at 200 ℃. It was also found that the mesostructure SnO2 with small particle size had higher sensitivity and selectivity to C2HhOH than the SnO2 nanoparticles the particle size of which is 20 nm synthesized by sol-gel method.     

掺加二氧化钛的锆乳浊釉实验研究

在卫生陶瓷大生产锆乳浊釉的基础上,选择加入适量的二氧化钛作为乳浊剂进行乳浊釉配方实验。实验结果表明:在1 170℃氧化气氛条件下,乳浊剂总量为11%,且二氧化钛和锆英砂的加入量分别为6%和5%时,乳浊釉的乳浊效果最好。     

TiO2纳米线的制备与退火处理

文章利用水热法成功制备二氧化钛纳米线,对制作样品进行不同温度的退火处理,利用X射线衍射仪（XRD）分析表征二氧化钛纳米线的成份与晶型,采用扫描电子显微镜（SEM）对TiO2纳米线的形貌进行了分析表征。     

稀土三元催化剂对二氧化碳/环氧化合物共聚反应的催化机理研究

采用X射线光电子能谱(XPS)技术研究了二氧化碳与环氧丙烷共聚反应的稀土三元催化剂,探讨了中心金属的X射线光电子能谱与催化活性间的关系,指出稀土三元催化剂的活性中心在于配位活化后的锌氧键,稀土盐通过与烷氧基锌形成双金属桥键,改变了活性中心的电子云分布,从而提高了反应活性.     

硅桥的一种近似解法

利用数值迭代方法,本文提出一种硅桥的近似解法,可用于硅压力传感器的温度补偿时电阻阻值的计算.     

充电碱锰电池用化学MnO2的制备

温度控制在85—95℃,在HNO3介质中,用KMnO4氧化Mn（NO3）2和Bi（NO3）3的混合溶液,可制成具有良好可充性能的掺铋二氧化锰（Bi—MnO2）。该样品在9MKOH溶液中有稳定的循环伏安曲线且经X射线衍射分析测得其在不同放电深度均无Mn3O4生成,这表明在MnO2中添加铋可阻止不具有电化学活性的Mn3O4生成;用该样品做成的模拟电池做连续充放电实验,电极的循环次数由原来的5-6次提高到60次以上。     

同时还原SO_2和NO的SnO_2-TiO_2固溶体催化剂的物理化学性质

用XRD,XPS,CO-TPD,NH3-TPD,SO2-TPD和IR等方法表征了SnO2-TiO2固溶体催化剂的物理化学性质,不同配比的SnO2和TiO2均可形成均一的具有金红石结构的连续固溶体,TiO2表面没有酸性,SnO2和SnO2-TiO2呈微弱酸性,经CO还原的SnO2-TiO2上存在大量的强碱中心,说明SnO2和TiO2之间发生了协同作用.SnO2-TiO2固溶体的这些物化性质均十分有利于SO2+NO+CO的氧化还原反应.