以活性碳纤维为载体的催化剂对NO的催化还原作用：二.镍系催化剂

前文报导了活性碳纤维（ＡＣＦ）载体催化剂Ｃｕ（ＮＯ３）２－ＡＣＦ在较低温度下就可催化ＮＨ３还原ＮＯ成为Ｎ２，但这种催化剂活性在高温时有随时间而明显下降的缺点。为了进一步探索新型高效长寿命催化剂，本工作研究了另一组催化剂体系－镍系ＡＣＦ载体催化剂外ＮＯ的催化还原作用，探讨了催化剂的结构以及各种影响催化效果的因素，实验结果再次表明ＡＣＦ在催化剂中起到活性载体的作用。Ｎｉ（ＮＯ３）２－ＶＡＣＦ催化剂在较高温度时对ＮＯ具有良好催化还原效果，在２５０～４００℃之间，其ＮＯ较化率比相同温度下的Ｎｉ（ＮＯ３）２－ＳｉＯ２对ＮＯ转化率高３０～４０％。Ｎｉ（ＮＯ３）２－ＶＡＣＦ催化剂的催化组分主要是单质镍，它的寿命比Ｃｕ（ＮＯ３）２－ＡＣＦ有明显的改善。催化剂负载量及催化剂用量增加或ＡＣＦ比表面积减少，ＮＯ转化率增加；载气流量及ＮＯ流量增加或ＮＨ３流量减少，ＮＯ转化率降低。     

金属离子在细菌浸取金属硫化矿中的催化作用

用氧化亚铁硫杆菌浸取某低品位原生硫化矿中Ｃｕ、Ｎｉ时，金属离子对细菌浸矿有明显的催化作用．金属离子（Ａｇ＋，Ｈｇ２＋，Ｃｏ２＋，Ｂｉ３＋）能显著提高细菌浸出Ｃｕ、Ｎｉ的浸出率．对细菌浸Ｃｕ而言，金属离子催化能力排序为：Ａｇ＋Ｃｏ２＋＞Ｂｉ３＋＞Ｈｇ２＋；对浸Ｎｉ，其排序则为：Ｂｉ３＋＞Ａｇ＋＞Ｃｏ２＋＞Ｈｇ２＋．金属离子的浓度、性质及矿石粒度等影响金属离子的催化能力．金属离子的催化作用机理与其性质、矿物结构及细菌氧化作用等因素有关     

CH4,CO2和O2制合成气反应中载体对Ni催化剂抗氧化性能的影响

在ＣＨ４、ＣＯ２ 催化氧化制合成气反应中, Ｎｉ／Ａｌ２Ｏ３ 催化剂在高温下生成ＮｉＡｌ２Ｏ４ 尖晶石,是导致催化剂失活的一个重要因素． 通过向载体（Ａｌ２Ｏ３）中添加各种氧化物, 使得催化剂的抗氧化性能得到改善． 并运用ＴＰＲ、ＸＲＤ对催化剂进行表征, 发现催化剂的抗氧化性顺序为： Ｎｉ／ＣａＯ－Ａｌ２Ｏ３ ＞ Ｎｉ／ＭｇＯ－Ａｌ２Ｏ３ ＞ Ｎｉ／ＣｅＯ２－Ａｌ２Ｏ３ ＞ Ｎｉ／Ｌａ２Ｏ３－Ａｌ２Ｏ３ ＞ Ｎｉ／Ｙ２Ｏ３－Ａｌ２Ｏ３ ＞ Ｎｉ／ＴｉＯ２－Ａｌ２Ｏ３＞ Ｎｉ／Ａｌ２Ｏ３＞ Ｎｉ／Ｆｅ２Ｏ３－Ａｌ２Ｏ３．     

甲烷部分氧化制合成气Ⅳ．镍铜催化剂的反应性能及影响因素的考察

对镍铜甲烷部分氧化催化剂的制备化学研究表明，在Ａｌ２Ｏ３、ＳｉＯ２、ＭｇＯ、ＴｉＯ２、Ｙ型分子筛等载体中，具有较好氢溢流功能的Ａｌ２Ｏ３所担载的镍铜催化剂，有最佳的反应性能，载体的产物溢流功能对反应中合成气的生成是有利的．对于ＮｉＯ－ＣｕＯ－Ａｌ２Ｏ３催化剂，组分Ｃｕ的最佳含量是Ｃｕ／Ａｌ＝０．２／４（原子比），Ｎｉ／Ａｌ（原子比）在１／４－１．５／４范围内催化剂均保持最佳的反应性能，此时，甲烷转化率为９８．１％，对ＣＯ、Ｈ２的选择性分别达９７％、１００％．制备方法对催化性能影响的结果显示，以（ＮＨ４）２ＣＯ３为沉淀剂的共沉淀法，是制备ＮｉＯ－ＣｕＯ－Ａｌ２Ｏ３催化剂的最佳方法．ＮｉＯ－ＣｕＯ－Ａｌ２Ｏ３催化剂的甲烷部分氧化性能在４００－５００℃间有一突跃，并在７００℃时达到最佳值；过高的反应气空速对ＣＯ、Ｈ２的选择性是不利的     

甲烷部分氧化制合成气Ⅱ．镍系催化剂的反应性能

主要用第四周期金属元素的氧化物与Ａｌ２Ｏ３的复合氧化物催化剂上甲烷氧化的结果证实了催化剂设计中的预测：（１）催化剂首先应能解离活化甲烷，（２）催化剂要能较快地活化Ｏ２分子．只有同时满足这两个条件，催化剂才可能有较好的甲烷部分氧化活性．第四周期元素中只有镍具有这样的性质．Ｃｕ，Ｍｎ，Ｃｒ，Ｌａ，Ｃａ，Ｚｎ等氧化物的添加可明显提高Ｎｉ－Ａｌ２Ｏ３催化剂的甲烷部分氧化性能，其中Ｃｕ的助催化性能最好．催化剂ＮｉＯ－ＣｕＯ－Ａｌ２Ｏ３，ＮｉＯ－ＭｎＯ－Ａｌ２Ｏ３，ＮｉＯ－Ｃｒ２Ｏ３－Ａｌ２Ｏ３的反应活性和选择性顺序，与金属Ｃｕ，Ｍｎ，Ｃｒ上ＣＯ和Ｈ２脱附的顺序是一致的     

La和Bi对乙炔与甲酸甲酯加氢酯化合成丙烯酸甲酯的镍基催化剂性能的影响(英文)

在２２０℃和５０－６０大气压条件下,利用固定床对ＮｉＯ／ＳｉＯ２、ＮｉＯ／Ａｌ２Ｏ３、ＮｉＯ－Ｌａ２Ｏ３／Ａｌ２Ｏ３和ＮｉＯ－Ｂｉ２Ｏ３／Ａｌ２Ｏ３催化剂上的乙炔与甲酸甲酯加氢酯化合成丙烯酸甲酯进行了研究。镍基催化剂对乙炔的加氢酯化合成丙烯酸甲酯具有很好的活性。用浸透法制备的Ｍｏ／ＳｉＯ２催化剂的活性和丙烯酸甲酯的选择性均比离子交换法差。ＮｉＯ／Ａｌ２Ｏ３催化剂用Ｌａ或Ｂｉ改性后,其催化活性大大提高。ＸＰＳ、ＸＲＤ和ＴＰＲ结果表明,当催化剂用Ｌａ或Ｂｉ改性后,ＮｉＯ的晶粒明显减小,催化剂表面的Ｎｉ／Ａｌ原子比增大,催化剂的第二个还原峰温大大降低。     

ABO3,A2BO4型复合氧化物催化剂用于CO,CH4,NH3完全氧化的比较

本文探讨了ＣＯ，ＣＨ４和ＮＨ３在ＬａＮｉＯ３，Ｌａ２ＮｉＯ４和ＬａＳｒＮｉＯ４三个催化剂上的氧化行为，并得出结论：对于ＣＯ氧化，关键步骤在于ＣＯ在催化剂表面上的络合活化。Ｎｉ＾３＋含量越高，越利于ＣＯ的络合活化。对于氨氧化，催化反应遵循氧化－还原机理。Ｎｉ＾３＋是主要的活性离子，晶格氧是主要活性氧种。对于ＣＨ４氧化，催化机理较复杂，只是发现Ａ２ＢＯ４型氧化物（Ｌａ２ＮｉＯ４，ＬａＳｒＮｉＯ４）比Ａ     

溶剂化金属原子浸渍法制备的Ni-Ag/γ-Al2O3催化剂的结构表征

应用溶剂化金属原子浸渍法和普通浸渍法制备了三种不同摩尔比的γ－Ａｌ２Ｏ３负载Ｎｉ－Ａｇ双金属催化剂。ＸＲＤ和磁测定结果表明ＳＭＡＩ催化剂中Ｎｉ和Ａｇ的粒度均小于金属相同的ＣＩ催化剂。ＳＭＡＩ催化剂中Ｎｉ和Ａｇ未形成合金，而ＣＩ催化剂中Ｎｉ和Ａｇ形成了合金。     

甲烷二氧化碳重整制合成气的镍基催化剂性能Ⅱ.碱性助剂的作用

考察了碱性助剂Ｋ２Ｏ，Ｌｉ２Ｏ，ＭｇＯ，Ｌａ２Ｏ３与ＣｅＯ２对Ｎｉ／γ－Ａｌ２Ｏ３催化剂上ＣＨ４－ＣＯ２重整反应活性和抗积炭能力等方面的影响，结果表明，这些助剂对催化剂的抗积炭能力都有明显的改善作用，ＣＨ４－ＣＯ２重整活性不同温度范围内也有不同程度的提高，其中，ＭｇＯ，Ｌａ２Ｏ３和ＣｅＯ２助剂的作用明显，但与添加顺序有关，先浸Ｎｉ后浸Ｍｇ制备的催化剂有较高的ＣＨ４转化率，但抗积炭能力远不如先浸Ｍｇ     

活性炭为载体加氢脱氮催化剂的研究

Ｍｏ／Ｃ、Ｎｉ／Ｃ和Ｎｉ－Ｍｏ／Ｃ催化剂吡啶加氢脱氮研究表明，Ｍｏ／Ｃ催化剂在Ｍｏ含量小于３．６５％时，随着Ｍｏ含量的增加，脱氮活性增加，其后趋于稳定。Ｎｉ／Ｃ催化剂也具有加氢脱氮活性，在Ｎｉ含量为５％左右达到最大值。Ｎｉ－Ｍｏ／Ｃ催化剂只有在Ｎｉ和Ｍｏ相互匹配时才具有较高的活性。ＸＰＳ的研究表明，硫化后Ｎｉ－Ｍｏ／Ｃ催化剂的Ｍｏ主要是以ＭｏＳ２的模型存在的；Ｎｉ是以ＮｉＳ和Ｎｉ３Ｓ２的混合生存在     

国产硅藻土吸附尿激酶机理的研究

在常温下, 尿激酶在浙江土和吉林土表面的吸附等温线分别为V型和II型; 焙烧后两者皆转为III型。吸附等温线类型与硅藻土表面结构、孔结构、表面ζ电位有关。在400℃焙烧的硅藻土等电点值最低, 吸附量最大; 改性后, 吸附量也发生改变。本文还测定了尿激酶在硅藻土表面的吸附形态, 其吸附等温线方程符合0/(1-0)=(Kc)^1/β, 并讨论了平衡常数K和尿激酶吸附功能链段数β随温度的变化。     

DFT Study on the Effect of Hydrogen-bond Formation on the Adsorption of Aminotriazines on Graphene

DFT calculations have been performed to explore the aminotriazine adsorption on graphene surfaces.Relative energies,equilibrium geometries and electronic structures of monomer and dimer of aminotriazine molecules adsorbed at the surface were investigated and analyzed in details.It was found that the hydrogen atoms in the NH2 group of aminotriazine molecules are directed toward the graphene surface,and the adsorption energy increases as the NH2 group is added.The adsorbed aminotriazine molecules facilely form a dimer through the hydrogen bonding interactions,and the two aromatic rings of optimized structure of 2-amino-1,3,5-triazine(B) dimmer(denoted by B2) and melamine(D) dimmer(denoted by D2) are parallel to the graphene sheet.The large deviation of the averaged adsorption energy of B2 and D2 compared to monor adsorption may reflect the increase of π-π repulsion and the effect of hydrogen bond formation.The electronic structure analyses reveal that the formation of hydrogen bonds in melamine dimer has great influence on the adsorption mode at the graphene surface.     

Investigations on the influence of the substrate on the crystal structure of sputtered LiCoO2

The influence of the uppermost substrate layer on the structural properties of sputtered lithium cobalt oxide (LiCoO₂) is discussed in this work. For this purpose, bare, oxidized, and platinum-coated silicon wafers, as well as stainless steel and titanium sheets, were used as substrates. The resulting crystal structure of LiCoO₂ deposited on these substrates was analyzed and discussed. The LiCoO₂ thin films were deposited by RF magnetron sputtering with different film thicknesses. A subsequent annealing step at 700 °C was performed to induce the crystallinity of LiCoO₂. The crystal orientation was determined by X-ray diffraction. The obtained results show a strong dependency of LiCoO₂'s crystal structure on the surface the film is deposited on. However, the strong influence of the film thickness reported in previous publications could not be observed. If LiCoO₂ is deposited on the substrates with a metallic surface, a strong (003) preferential orientation is obtained for a wide range of film thicknesses. In contrast, sputtering of LiCoO₂ on bare and on oxidized silicon wafers results in a (101) dominated crystal structure for the different film thicknesses. These experiments show the importance of the characterization of LiCoO₂'s crystal structure in the intended battery setup.     

Study on the stability of the serotonin and on the determination of its acidity constants

The present work aimed at describing the spectral behaviour of the serotonin and to evaluate its acidity constants using three different methods, using two spectrophotometry titrations and a third method that involved point-by-point analysis, which permitted to monitor closely and determine the evolution of the serotonin species in solution as a function of time. The three methods allowed estimation of three acidity constants associated to the same number of functional groups that form part of the molecule. The results given by the point-by-point analysis were: log(beta1) = 24.95 +/- 0.12; log(beta2) = 20.20 +/- 0.10; log(beta3) = 10.89 +/- 0.018.     

La传感器在测定铝液凝固过程中La活度研究

微量稀土加入铝或铝合金中，如果加入方法、数量、时间得当，可明显改善材料的多项性能．稀土对铝及铝合金的影响规律和作用机理，已取得了一些进展，但对稀土铝合金的热力学性质，尤其是溶解态稀土的研究少有报导［‘，2］．本工作采用L即．95C。。。。FZ。。多晶作为固体电解     

Effect of the temperature on the thermodynamic characteristics of the ion-exchange separation of substances on ionites

The basic results on the effect of temperature on the equilibrium and thermodynamic characteristics of ion-exchange systems and the use of this effect in developing reagentless methods for ion-exchange separation are considered.     

第三相界面对高分子共混物粗化过程的影响研究

共混物相分离的机理已有研究［１］．但对共混物分散相的粗化过程的研究则不多见．１９７７年,Ｃａｈｎ等［２］预言第三相界面与低分子共混物之间存在的浸润作用对相分离过程应有较大影响．近年Ｔａｎａｋａ等［３］的研究结果表明,在几何空间受限的条件下,含有小分子...     

Simulation Analysis on the Profiles of Droplets Wetting on the Substrates

To study the structural characteristics and physical properties of droplets sitting on the inclined substrates and cylindrical surfaces, wetting experiments are conducted in different cases. The profile curves of the droplets are recorded and extracted by a CCD camera and image processing, respectively. Contact angles are figured out by fitting the profile curves and taking the derivative at the front and rear triple points. Based on the experimental results, a Surface Evolver is employed to simulate the morphological changes by minimizing the total energy of the system. Furthermore, theoretical shapes and feature parameters, including the heights and the spreading distances of the droplets, which are hard to obtain by normal experimental measurements are provided. The contact-angle hysteresis when the heavy droplet sitting on the inclined substrate is discussed. Meanwhile, the evolutions of the contour of the three-phase contact line are predicted when heavy droplets spread on the convex and concave cylindrical surfaces, respectively. This study provides a finite-element analysis method to describe the surface properties of molten droplets on different substrates, and the simulation results agree well with the experimental results.