MCM-41分子筛负载Pd/La_(0.8)Ce_(0.2)MnO_3低温催化燃烧甲苯实验研究

以贵金属改性的钙钛矿为活性组分,采用等体积浸渍法制备Pd/La0.8Ce0.2MnO3/MCM-41催化剂,以甲苯为模型污染物进行催化燃烧实验,考察焙烧温度、负载量对催化反应的影响,并通过XRD、BET、SEM等手段对催化剂进行表征。结果表明:Pd/La0.8Ce0.2MnO3/MCM-41催化剂具有完整的钙钛矿型结构,Pd在钙钛矿型氧化物上得到高度的分散,同时MCM-41也发挥了很好的载体效应,有利于催化剂活性的发挥;La0.8Ce0.2MnO3负载量为20%、焙烧温度在750℃,起燃温度和完全转化温度分别为203和283℃;在加入0.05%Pd后,La0.8Ce0.2MnO3/MCM-41催化活性显著增强,甲苯完全转化温度仅为235℃;催化剂表面活性组分具有高分散性,活性组分颗粒粒径均一,分散均匀。     

负载型贵金属催化剂用于汽车尾气净化的实？…

以金属氧化物及稀土元素为助剂,以蜂窝状堇青石陶瓷为载体的贵金属催化剂。用于汽车尾气中ＣＯ、烃类氧化反应,经比较,Ｐｄ－Ｃｅ－Ｂａ催化剂具有低起燃温度、高效、热稳定好的特点,对ＣＯ、烃类（ＨＣ）氧化起燃温度和完全氧化温度分别约为１２０、１６０和１４０、１９０℃。稀土元素和碱金属在催化剂表面的富聚和在活性氧化铝涂层中的存在,对其它活必组分起分散、隔离和稳定的作用,保证了催化剂良好的热稳定性。     

负载型贵金属催化剂用于汽车尾气净化的实验研究

以金属氧化物及稀土元素为助剂 ,以蜂窝状堇青石陶瓷为载体的贵金属催化剂 ,用于汽车尾气中CO、烃类 (HC)氧化反应 ,经比较 ,Pd Ce Ba催化剂具有低起燃温度、高效、热稳定好的特点 .对CO、烃类 (HC)氧化的起燃温度和完全氧化温度分别约为 12 0、16 0和140、190℃ .稀土元素和碱金属在催化剂表面的富聚和在活性氧化铝涂层中的存在 ,对其它活性组分起到分散、隔离和稳定的作用 ,保证了催化剂良好的热稳定性     

催化燃烧VOCs的三种过渡金属催化剂的活性比较

利用浸渍法将过渡金属硝酸盐溶液沉积在γ—Al2O3上,通过焙烧制得三种过渡金属氧化物催化剂CuO／γ-Al2O3、CdO／γ-Al2O3和NiO／γ—Al2O3,通过催化燃烧销毁乙醇、丙酮和甲苯的实验,对催化剂活性进行了评价．实验结果表明,在催化剂作用下,三种挥发性有机化合物VOCs催化燃烧的起燃温度和完全燃烧温度都明显低于它们的燃点,其中CuO／γ-AlO3催化剂的催化活性优于CdO／γ—Al2O3和NiO／γ—A12O3催化剂,它对丙酮、乙醇和甲苯的催化起燃温度分别是180,190和230℃,另外对于催化燃烧VOCs,挥发性气体分子的极性越大就越容易被氧化。     

氧化铜-碳纳米管催化剂的制备及其脱硝性能研究

首先成功制备了CuO负载的碳纳米管脱硝催化剂,进而探讨了CuO的负载量、煅烧温度、反应温度等对催化剂脱硝效率的影响,以及K2SO4、Na2SO4、NaCl、KCl 4种碱金属盐和SO2对该催化剂的毒化作用.结果表明:1)当CuO负载量为10%、煅烧温度为300℃、反应温度为250℃时,催化剂的催化效率最高,NO的转化率可达90.5%;2)碱金属盐及SO2对催化剂有着明显的毒化作用.     

镍负载量对自热转化催化剂Ni/γ-Al2O3性能的影响

利用常压固定床微反色谱联用装置、X 射线衍射 (XRD)以及程序升温还原等分析手段 ,考察了镍负载量对自热转化催化剂Ni/γ Al2 O3 的活性和还原性能的影响。实验结果表明 ,对于 10 0 0℃下焙烧的模型催化剂Ni/γ Al2 O3,用XRD检测均未发现NiO(2 0 0 )特征峰 ;而当镍含量达到 8.1%时 ,XRD可检测到以尖晶石形式存在的镍。模型催化剂中NiAl2 O4 的还原性能低于NiO。催化剂中镍的负载量在一定范围内增加 ,可使起始还原温度下降 ,催化剂转化活性升高。分析结果表明 ,镍负载量为 7.7%的催化剂还原温度低 ,转化活性很好 ,能有效地抑制催化剂的积炭 ,具有最佳的综合性能     

铜基铈铁钇复合氧化物的制备及催化性能研究

采用反向滴定共沉淀法制备铈铁钇复合氧化物(Ce1-xFexYzO2-λ)载体,然后用等体积浸渍法负载活性组分Cu,研制铜基铈铁钇复合氧化物(Cuy/Ce1-xFexYzO2-λ)催化剂.实验结果表明:Ce:Fe:Y摩尔比为0.9:0.1:0.05、Cu负载量为3%时,制得的Cu3%/Ce0.9Fe0.1Y0.05O2-λ催化剂对CO、NO和C3H6的转化反应具有良好的催化活性,在该催化剂上CO、NO和C3H6的起燃温度(T50)分别为100℃、234℃和258℃,完全转化温度(T90)分别为183℃、318℃和350℃;由于Fe和Y能与Ce氧化物形成稳定的立方晶固溶体,载体表面不出现Fe、Y或Cu物种晶相聚集的现象,Ce与Fe和Y之间的良好协同效应有利于提高催化活性和热稳定性,因此Cu3%/Ce0.9Fe0.1Y0.05O2-λ催化剂性能良好.     

掺铈负载型氧化铜催化剂催化氧化甲苯研究

以60～80目的γ-A12O3为载体,CuO为活性组分,添加稀土元素Ce,用浸渍法制备了负载型催化剂,通过催化氧化甲苯评价了该催化剂的活性.相对于CuO/Al2O3催化剂,添加Ce后的CuOCeO2/Al2O3催化剂对甲苯催化氧化的起燃温度和完全转化温度均有明显的降低,当Cu的负载量为5%,Cu/Ce的比值为1∶1,反应温度大于200 ℃时对甲苯的去除率可保持在90%以上.CuOCeO2/Al2O3催化剂具有较强的抗冲击能力,能够在较大范围的空速和进气质量浓度下,保持良好的催化活性.当空速在6 000～12 000 h-1的范围内,对甲苯的去除率始终保持在98.8%以上;当进气质量浓度在880～6 400 mg/m3的范围内,对甲苯的去除率均在99.5%以上.     

不同载体Pt基整体式催化剂对氢气低温反应性能的影响

以H型分子筛-5(hydrogen zeolite sieve molecular-5,HZSM-5)和氧化物(Al₂O₃、TiO₂和SiO₂)涂层为载体、堇青石蜂窝陶瓷为基体、贵金属铂(Pt)为活性组分,制备了Pt/载体/堇青石整体式催化剂.利用XRD、SEM、TEM和XPS等表征手段,对催化剂的结构与性质进行了分析.探讨了在氢气体积分数为2.5%的环境中,不同载体、不同Pt负载量对氢气低温催化燃烧反应性能的影响.研究结果表明：以HZSM-5为载体的整体式催化剂性能最优,这与催化剂活性层黏结性良好、Pt在该载体上的分布良好及其粒径均匀有关;以SiO₂为载体的催化剂性能最差,测试显示这种载体上Pt⁰种类含量最少,且Pt负载不牢;Pt负载量为0.01 g·L^-1时,Pt/HZSM-5/堇青石整体式催化剂的催化活性较好;Pt负载量为0.05 g·L^-1及以上时,整体式催化剂均能在室温下快速起燃,并实现氢气转化率为10...     

电解负载法制备Pt/Al2O3/Al催化剂

以铝板阳极氧化生成的多孔质氧化膜为载体,采用电解负载法将铂负载在载体上,制得挥发性有机物催化燃烧的催化剂.从催化剂的负载量和催化活性出发,对电解负载的实验条件进行了探讨.研究结果表明,低浓度、低电流密度及较短的电解负载时间是较适宜的催化剂制备条件.实验还表明,利用电解负载法负载的催化组分在催化剂中分布均匀.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

The Analects and the Moment in Peking——The influence of a Confucian education system on the personality formation,the way of thinking and the fate of the main characters

0.Preface China has long been boasting of its colorful and immense culture which comprises of Taoism,Confucianism and Buddhism.The interwoven influence among the religions on Chinese way of thinking,on the nation＇s behavior in their social life throughout the long history is beyond list.