不同沉淀剂对Ce0.5Zr0.15Y0.075La0.075Al0.2O2性能的影响

采用不同的沉淀剂,用共沉淀法制备了Ce0.5Zr0.15Y0.075La0.075Al0.2O2复合材料,并通过氧脉冲吸附、BET、XRD、SEM及TPR对所制备的材料进行了表征,同时考察了焙烧温度对该材料结构性能的影响.结果表明,以碳酸铵-氨水为混合沉淀剂时,该材料表现出良好的储氧性能、织构性能、结构性能和抗老化性能;在不同的焙烧温度下均属同晶转化,样品保持稳定的萤石立方晶相固溶体结构.     

Multiplier Free IDCT Engine at MPEG-1 Video Data Rate

0~chopInspiteofcurmntbarkintheareaofstillimage.compressionandvideocompression['-'j,theJPEGandMPEGs}'stemsstinlankasthetWOdominantstandardsinstillimageandvideoimagecompression.FOrwaulandInverseDiscreteCosineTlansform.formanintegralpartofanyJPEGandMPEGsystem"-3).UPtonow,manydifferentalgoritLhlnstOdothediscretecosinet~formhavebeenproposed['-12].WhentakenintotheaccountofJPEGaccuracycompliance...id.rti..L13],thefastDCTalgorithmbyFeig[']reqUiresthedrinimumnumberofallthlneticoperahonsam…     

Effect of Metal Oxide Doping into Ce_(0.5)Zr_(0.5)O_2 on Catalytic Activity of MnO_x/γ-Al_2O_3/Ce_(0.45)Zr_(0.45)M_(0.1)O_x (M=Y, La, Mn) Honeycomb Catalysts

Volatile organic compounds (VOCs) are recog-nized as major contributors to air pollution ,either di-rectlythroughtheir toxic or malodorous nature or indi-rectly as ozone precursors and smog precursors[1].Amongthe methods used to eli minate VOCs ,catalytic…     

转移预测的局限性及可能的解决方案

转移指令，特别是条件转移指令是影响超标县处理器性能的关键。尽量减少转移指令所带来的损失，这是现今高性能处理器（如超标量处理器）设计中的关键问题一也是当今国际国内研究的热点。在众多的转移处理策略中，二级自适应预测（相关预测咽其相对性能最高而被广泛研究，且已被应用到商用处理器中。以一个程序为实例，通过踪迹驱动模拟分析了其局限性。并指出，多条件码和条件式执行技术与转移预测相结合，可减少条件转移指令和误预测率，提高处理器的性能。     

Effect of BaO on Catalytic Activity of Pt-Rh TWC

The effects of BaO doping on the three-way catalytic activity of Pt-Rh catalyst and on water-gas shift were investigated. The results show that the light-off temperatures of hydrocarbon and carbon monoxide and nitrogen oxides of the fresh catalysts slightly differ from those of the aged catalysts, and the catalysts containing CeO2-ZrO2-BaO have lower lightoff temperature and better catalytic activity than these containing BaO and CeO2-ZrO2 after hydrothermal aging for 5 h at 1000 ℃. The catalysts were characterized by means of the temperature-programmed reduction （TPR） in hydrogen and the temperature-programmed desorption （TPD） in oxygen. It is confirmed that the suggested route of CeO2-ZrO2-BaO by coprecipitation can improve the catalytic activity of catalysts.     

Partial Oxidation of Methane to Syngas over Monolithic Ni/γ-Al2O3 Catalyst——Effects of Rare Earths and Other Basic Promoters

Overthe last fewyears ,partial oxidation of meth-ane (POM)tosyngas has attractedincreasing attentioninthe field of catalysis[1 ,2].Compared withtraditionalgranular catalysts , monolithic catalysts are more suit-able for practical application of heterogeneously cata-lyzed gas/liquid reactions ,with many advantages suchas lowpressure drops ,excellent heat and gas conduc-tivity ,and larger external surface areas .The active components in the catalysts of POMmainlyinclude noble metals andtransit…     

TiN、Al2O3涂层对燃料裂解结焦的抑制效果研究

为抑制镍基不锈钢油道本身对吸热型碳氢燃料裂解的金属催化结焦积碳作用,采用化学气相沉积法在Ф3 mmφ0.5 mm,800 mm长的3128型不锈钢基体管道内表面分别沉积了TiN和Al2O3涂层,沉积温度分别为950和1050℃,沉积时间为3 h。通过SEM、EDS和XRD分析了涂层的形貌特征和组织结构。SEM结果表明,CVD法制备的TiN、Al2O3涂层结构均匀致密;EDS结果显示,实验制得的氮化钛涂层的组成为非化学计量比的TiN0.67,氧化铝涂层的Al和O原子比为1:3;XRD结果表明,实验所得到的TiN为立方晶相结构,Al2O3为惰性的α-Al2O3。以二甲苯为原料采用自制的超临界裂解装置对TiN、Al2O3涂层的钝化效果进行了评价。二甲苯超临界裂解实验结果表明,TiN涂层钝化效果不明显,而Al2O3涂层的钝化效果十分显著,达到2倍的钝化效果。     

胶体金免疫层析法快速检测水样品中的镉离子

目的研制检测水样品中镉离子残留的胶体金免疫层析快速检测试纸条。方法采用免疫竞争法,将抗Cd2+-EDTA单克隆抗体-胶体金复合物包被于胶体金结合垫上,并将人工合成的Cd-iEDTA-BSA检测抗原包被在硝酸纤维素薄膜表面,作为检测线(T线),3～5min后,根据颜色直观显示检测结果。对试纸条进行灵敏度、特异性和稳定性验证,并检测添标水样。结果制备的试纸条对镉离子的最低检测限为100ng/ml;除了与Hg2+-EDTA有交叉反应外,与Fe3+、Pb2+、Cu2+等类似物无交叉反应;试纸条在常温下放置8周稳定性良好;检测添标水样的结果与ICP-AES的检测结果一致。结论胶体金免疫层析法操作便捷,稳定可靠,可作为水样中重金属镉离子残留现场检测和监控的有效手段。     

整体式甲烷燃烧催化剂的活性研究

研究了以Co、Cr、Mn、Fe和Ni的单一或混合氧化物为活性组分的整体式催化剂在甲烷燃烧反应中的活性。整体式催化剂直径为 10mm ,长 15mm ,测试温度范围为 30 0 - 70 0℃。结果显示 ,单一氧化物中Co、Cr和Mn的活性较好 ,Fe和Ni的活性较差 ;混合氧化物催化剂均表现出较高的活性 ,但以含Co、Cr、Mn的 3组分混合氧化物催化剂为更佳。同时考察了空速、烷氧比、稀释气、温度等因素对甲烷燃烧反应的影响。在烷氧比为 1:4,稀释气含量约为 6 0 % ,反应温度 6 5 0℃ ,大空速下甲烷转化率较高。     

Effects of La_2O_3 contents on the Pd/Ce_（0.8）Zr_（0.2）O_2-La_2O_3 catalysts for methanol decomposition

The catalytic behaviors of Pd (1.4 wt.%) catalysts supported on CeO2-ZrO2 promoted with La2O3 were investigated for methanol decomposition. The measurements of inductively coupled plasma emission spectroscopy (ICP), N2 adsorption-desorption (BET), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR) and oxygen storage capacity (OSC) were used to characterize the properties of catalysts. The catalysts' activities were tested in a fixed bed continuous ...