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FENG Changgen ZHUO Xiaoxi LIU Xia 《中国稀土学报(英文版)》2009,27(5):717-722
A series of photocatalysts, K11[Ln(PW11O39)2]/PVA (Ln=La, Ce, Pr, Nd, Sm) were prepared by K11[Ln(PW11O39)2] (Ln=La, Ce, Pr,Nd, Sm) containing five kinds of lanthanides and polyvinyl alcohol as the support. The catalysts obtained were characterized by Fourier trans-form infrared spectra, UV-vis spectra, powder X-ray diffraction, and scanning electron microscopy, indicating that the structure of K11[Ln(PW11O39)2] and polyvinyl alcohol remained intact, respectively. The photocatalysts exhibited efficient catalytic activity to degrade methyl orange, Congo Red, Ponceau 2R. The maximal degradation conversions of the three kinds of dyes were 99.58%, 47.61%, 72.42%, respectively. 相似文献
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在香港校园里,常常有这么一群特殊的人,她们每天早早地来到学校,为学生测量体温,观摩学校早会,协助管理图书,课余为学生讲故事,中午帮学生盛饭,甚至为学校编辑刊物,放学为低年级学生辅导作业……俨然是学校的正式教师,其实是学生家长,她们为学校,帮老师做了很多事情,都是义务的,没有任何报酬,在香港,通常把她们称之为“家长义工”。 相似文献
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业绩略低于预期第三季度公司实现营业收入1471394万元,同比上涨30.67%,净利润91950万元,同比下降26.9%,每股收益0.30元,前三季度实现营业收入4154476万元,同比上涨45.46%,净利润369876万元,同比增长13.76%,每股收益1.22元,业绩略低于市场的普遍预期。 相似文献
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提出了用火焰原子吸收光谱法测定金锭中Cu,Ag,Fe,Pb,Bi,Sb的方法。用乙酸乙脂萃取分离金,水相浓缩后测定6种待测元素,方法的检出限:Cu,Ag,Fe为0.021mg/L,Pb,Bi,Sb为0.24mg/L;回收率94%~106%;RSD小于10.6%。该方法快速、简便,样品用量少,测定结果与ICP AES法和国家标准方法一致。 相似文献
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型铁中Si,Mn,P,S四大元素的测定是型铁质量评价的主要内容。以往化学法分析Si,Mn,P,S四大元素,劳动强度大,工序繁琐,偶然误差因素多,分析周期长,准确度低。近年来,X射线荧光光谱仪在冶金、地矿、水泥等分析应用方面,得到迅速发展,它具有自动化程度高,操作简单、快速、准确、非破坏性等优点,本文应用3530荧光光谱仪,分析型铁中的Si,Mn,P,S四大元素,取得了成功,方法简单、准确、快速。1实验部分1.1仪器和试剂3530X射线荧光光谱仪(日本理学),Rh靶,端窗X射线管;PR—10气体;… 相似文献
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Theoretical models featuring cognitive processes have played a fundamental role in advancing knowledge of psychopathology and its treatment and have emphasized the importance of cognition in psychotherapy. Recognition of the importance of cognition in psychotherapy has led to a number of questions that are addressed by the articles in this special section of the Journal of Consulting and Clinical Psychology. Cognitive therapy is well represented in the articles in this special section, but therapeutic procedures that do not represent typical cognitive therapy are also examined. The articles in this special section focus on homework in the modification of cognition, cognition in the treatment of anxiety in adults and in children, change in depressive cognitions in children, cognition and rapid change in the treatment of depression, and the role of cognition in the treatment and prevention of depression that is recurrent. Examination of these types of questions holds the possibility of advances in existing treatments and the possibility of innovations in new treatments. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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摘要:对链箅机回转窑工艺中各段球团样品进行实验分析,研究了氯元素和硫元素在链箅机回转窑工艺中的迁移规律,明晰了烟气中HCl的生成机制。结果表明,球团原料中的氯元素主要是以NaCl的形式存在,氯元素有一部分在链箅机抽风干燥段会转变成HCl气体并进入烟气,一部分在链箅机预热Ⅱ段之后以NaCl的形式汽化进入烟气,剩余的氯元素仍以NaCl的形式存在于成品球团矿中。烟气中的HCl气体是在抽风干燥段,由富含SO2的烟气与含水球团料层中的NaCl发生反应生成的,烟气中SO2转变成Na2SO4重新固定于料层中。在预热Ⅰ段和预热Ⅱ段,烟气中的SO2与原料中碳酸钙分解生成的游离CaO反应生成CaSO4,也会重新固定烟气中的SO2。 相似文献
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以水稻土—地表水铀含量为视角,从水稻土剖面铀含量分布规律、水稻土与下伏岩体稀土元素特征、不同河流不同河段水稻土—地表水—稻米铀含量特征、水稻土与稻米铀含量关系4个方面研究721铀矿区稻米铀含量成因。结果表明,水稻土剖面铀含量从表层至半风化花岗质基岩层呈明显降低的特征,说明水稻土铀含量高的原因不是土壤母质铀含量高;岩石与水稻土稀土元素标准化模式均表现为向右倾斜型,均属轻稀土富集型,轻稀土分馏明显,表明水稻土为还原环境,吸附作用较强;不同河流不同河段水稻土—地表水—稻米铀含量平均值的特性均为上游最低、中游最高、下游次之。铀矿区地表水环境符合铀元素在水稻土中被平衡吸附的动力学条件,有利于铀元素在矿区内河流中游地区的水稻土中沉淀富集;正在采矿区水稻土与稻米铀含量具有高度的空间耦合性,呈指数正相关关系,相关系数0.749。矿区内河流沿岸稻米铀含量的分布特征是由铀元素的迁移途径决定的"采矿活动(铀尾矿露天堆放)→地表水→水稻土"。 相似文献
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B. Babatope P. R. Williams D. J. A. Williams 《Canadian Metallurgical Quarterly》2008,134(9):1333-1336
A laboratory characterization of cohesive sediment has been carried out in which data obtained from standard sedimentation and rheological measurements were combined in a determination of the critical solid concentration for the detection of elasticity in a weakly cohesive suspension. The corresponding storage modulus and shear stress are very critical in any in situ rheometry of sediments, especially in the study of mud-water surface erosion in a flume. Sedimentation results showed that particle size distribution rather than surface treatment controlled the rheological behavior of the suspension while the critical solid concentration for the appearance of three-dimensional space-filling network, showing some measurable elasticity in the suspension, occurred in the region of 0.015. This parallel between the consolidation behavior and shear rheology development for the flocculating system has been established. This technique could be an adjunct to the laboratory characterization of cohesive sediments for the estimation of critical shear stress for surface erosion, especially in a typical flume experiment under water wave pressure. 相似文献
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简要归纳了国内目前焦炭硫分预测方法,指出了不足。通过32个单种煤硫分形态与焦炭硫分关系研究,分析了硫分形态对焦炭硫分的影响;通过分析炼焦过程炼焦煤硫分变化,提出传统室式炼焦过程脱硫反应和固硫反应并存,煤气中H2具有脱硫功能,灰中CaO和MgO是固硫剂;60个样品试验数据的回归分析结果表明,煤的全硫和灰中(CaO+MgO)含量是影响焦炭硫分的主要因素。 相似文献
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The use of flow resistance in the distribution of flows is well known in traditional hydraulics. To evenly distributed flows, flow resistance forms the basis of flow distribution in pipes connected in parallel. Flow distribution in different zones of upflow anaerobic sludge blanket (UASB) reactors is well documented in existing literature, and so far modeling of flow distribution parameters, i.e., the fraction of inflow entering into the bed, the fraction of flow bypassing over the bed and entering into the blanket, and the fraction of inflow to the bed entering into the blanket, has remained empirical in nature. The role of flow resistance in the distribution of flows in UASB reactor systems is still unexplained. In this study, some of the available data on flow distribution parameters are analyzed to assess if there is any correlation between these parameters and flow resistance. It is found that with an increase in flow resistance in the UASB reactor system, the magnitude of short-circuiting flows at the reactor bed increases. Also, the flow distribution at the blanket and settler levels of UASB reactor systems is related to parameters influencing flow resistance. Some of the functional forms derived in this study are expected to form the basis for representing flow distribution in the simulation studies of UASB reactor performance. 相似文献
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Fuller Rebecca L.; Luck Steven J.; Braun Elsie L.; Robinson Benjamin M.; McMahon Robert P.; Gold James M. 《Canadian Metallurgical Quarterly》2006,115(2):266
To investigate attentional impairment in schizophrenia, the authors examined the performance of 22 patients with schizophrenia and 16 healthy control subjects in 4 visual search tasks that varied in perceptual requirements and in the need for precise attentional control. The rate of search was slowed in the patients in all tasks. However, the degree of slowing was largest in tasks requiring precise attentional control and smallest in tasks that were perceptually difficult but required less attentional control. This pattern of results indicates that the primary impairment of attention in schizophrenia lies in the control of attention and not in the selection processes that operate once attention has been directed to an object. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献