La^3掺杂对纳米TiO2微观结构及光催化性能的影响

以钛酸丁酯和氧化镧为原料，采用溶胶－凝胶法制备了La^3掺杂TiO2纳米粉体，讨论了不同掺杂浓度，不同热处理温度的样品催化降解刚果红染料实验中的光催化活性，并通过X射线衍射（XRD）、透射电镜（TEM）分析了La^3掺杂TiO2样品的相组成、晶胞参数和晶粒大小对光催化活性的影响。结果表明La^3掺杂能够显著提高TiO2粒子的光催化活性，最佳掺杂浓度为100：3．0，最佳热温度为600℃；La^3掺杂的TiO2的相组成是影响光催化活性的决定性因素，晶格膨胀程度及晶粒大小对光催化活性的影响，主要是在相组成相或相近时才体现得比较明显。     

La3+离子掺杂对纳米ZnO光催化性能的影响

采用共沉淀法,选择尿素为沉淀剂,制备了一系列不同La3 掺杂浓度的纳米ZnO粉体.讨论了不同掺杂浓度的样品催化降解甲基橙的光催化活性,并通过X射线衍射(XRD)和透射电镜(TEM)等分析测试手段研究了粉体样品的相组成、晶胞参数和晶粒大小对光催化性能的影响.结果表明:La3 掺杂能够显著提高ZnO粒子的光催化活性.最佳掺杂浓度为100:0.2;最后提出了La3 改善纳米ZnO粉体光催化性能的作用机制.     

Ce-TiO2光催化剂的制备与性能研究

采用溶胶-凝胶法制备了稀土Ce离子掺杂的纳米TiO2光催化剂(Ce-TiO2),通过XRD、FT-IR、UV-Vis、PL、Nano-sizer纳米粒度分析仪等对Ce-TiO2样品进行了表征和分析,并以亚甲基蓝(MB)作为目标降解物,考察了不同掺杂浓度及经不同温度热处理后的Ce-TiO2样品对MB的光催化降解效果,结果表明所制备样品的晶型均为锐钛矿相和金红石相的混晶相,Ce离子的掺杂拓展了TiO2在可见光区的光谱响应范围,提高了TiO2光催化活性。当pH值为1.5,Ce的掺杂量为n(Ce)∶n(TiO2)=1∶300,热处理温度为600℃条件下制备的样品其催化活性显著高于Degussa P25。     

镧掺杂纳米二氧化钛光催化剂的制备及性能研究

采用溶胶-凝胶法制备了稀土La离子掺杂的纳米TiO2光催化剂(La-TiO2),通过XRD、PL、UV-Vis对La-TiO2样品进行了表征和分析,并以亚甲基蓝(MB)作为目标降解物,研究了不同热处理温度及不同La掺杂浓度的(La-TiO2)样品对MB的光催化降解效果。结果表明,所制备样品的晶型均为锐钛矿相和金红石相的混晶相,La离子的掺入拓展了TiO2对可见光的吸收范围,有效地抑制了光生电子-空穴对的复合,提高了TiO2的光催化性能。La的掺杂量为n(La)∶n(TiO2)=1∶200,热处理温度为600℃条件下制备的样品对亚甲基蓝的降解率为96.6%,显著高于Degussa P25(58.62%)。     

喷雾燃烧热分解制备Cr掺杂TiO2纳米粒子的可见光催化性能

采用一步喷雾燃烧热解法制备了Cr掺杂TiO2纳米粒子,研究了Cr掺杂对样品微结构、吸光特性和可见光催化活性的影响.结果表明:增加Cr掺杂量抑制锐钛矿相的形成,同时促进金红石相的形成.在低Cr掺杂量下(≤1%),Cr主要以Cr3+的形态进入TiO2晶格,而Cr掺杂量过大时,易于形成Cr2O3团簇.光催化降解2,4-二氯苯酚结果表明,适量的Cr3+掺杂可以有效地提高TiO2的可见光催化活性,获得最高光催化活性的Cr3+掺杂量为1at%.样品可见光催化活性的提高主要与Cr掺杂引起的可见光吸收增强.晶相组成改善以及光生电子和空穴传输效率提高有关.     

磁性La3+掺杂TiO2的制备及性能

利用溶胶-凝胶法,在室温条件下,以钛酸四丁酯、硝酸镧为主要原料,无水乙醇为溶剂,冰醋酸为抑制剂,浓硝酸为催化剂制得稳定的掺La3+TiO2溶胶,陈化后的凝胶经不同温度煅烧3h后制得不同掺La3+量的TiO2。通过XRD对不同煅烧温度及不同掺La3+量的TiO2进行了表征;以紫外光为光源,研究了掺La3+-TiO2对甲基橙溶液的光降解效果。用化学共沉淀法制备了具有强磁性的Fe3O4水基磁流体,再与La3+掺杂TiO2进行复合,制备了Fe3O4负载量不同的磁性La3+掺杂TiO2,研究了Fe3O4负载量不同的La3+掺杂TiO2对甲基橙的光催化降解效果、磁分离回收率的影响。结果表明,掺La3+量及煅烧温度对TiO2的晶型、各晶型TiO2的相对含量及对甲基橙的光降解效果均有影响。La3+掺杂TiO2比纯TiO2显示出更强的光催化性能,掺La3+量2%,热处理温度450℃的La3+掺杂TiO2光催化活性最高。Fe3O4负载量为10%的Fe3O4/La3+-TiO2对甲基橙的降解率8h时为99.4%;磁分离回收率达97.39%。     

Eu~(3+)掺杂纳米TiO_2的制备及催化降解亚甲基蓝的研究

采用溶胶-凝胶法制备了Eu3+掺杂的纳米TiO2粉体,采用X射线衍射(XRD)和荧光光谱分析(PL)等手段对TiO2的相结构和TiO2中电子-空穴对的复合性能进行了表征,探讨了掺杂组分对光催化活性的影响机制。以紫外光下降解亚甲基蓝为探针反应,考察铕的掺杂对催化剂催化性能的影响。结果表明Eu3+的掺杂能够通过抑制催化剂晶粒长大从而减少团聚,并且通过降低光生电子-空穴的复合几率,提高催化剂的光催化活性。光催化实验表明,催化剂加入量为3g/L,亚甲基蓝溶液初始浓度为20mg/L时,掺杂1%Eu3+的催化剂催化性能最佳,反应3.5h降解率达到85.5%。     

铁掺杂TiO2纳米粉的制备、表征及其光催化活性

以钛酸丁酯为前驱体,硝酸铁为杂质添加剂,利用溶胶-凝胶法制备了掺铁TiO2纳米粉.以苯酚水溶液的光催化降解反应为探针,评价了掺铁TiO2的光催化性能.借助X射线衍射分析(XRD)、荧光光谱(FS)、热重-差热分析(TG-DTA)等手段对掺铁TiO2催化剂进行了表征.结果表明,掺杂浓度和焙烧温度对掺铁TiO2纳米粉的光催化降解活性有很大影响.掺铁0.5%、煅烧温度为400 ℃的催化剂表现出最佳的光催化活性,在苯酚的降解中催化效率比未掺杂TiO2纳米粉约提高了1倍;并初步探讨了荧光强度对光催化活性的影响.     

Pr-TiO_2光催化剂的制备与性能研究

采用溶胶-凝胶法制备了稀土元素Pr掺杂的纳米TiO2光催化剂(Pr-TiO2)。通过XRD、FT-IR、UV-Vis、TEM等对Pr-TiO2样品进行了表征和分析,并以亚甲基蓝(MB)作为目标降解物,考察了不同热处理温度及不同掺杂量的Pr-TiO2对MB的光催化降解效果。结果表明,Pr掺杂纳米TiO2的晶型为锐钛矿相和金红石相的混晶相,Pr的掺入提高了TiO2光催化活性。当热处理温度为500℃,在pH值为2.5,Pr掺杂量为n(Pr):n(TiO2)=1:300的条件下制备的光催化剂的催化活性显著高于DegussaP25。     

电气石/La/TiO2光催化材料的合成与表征

以硝酸镧、天然电气石(Tourmaline,简称T)和钛酸丁酯为原料,采用溶胶-凝胶法制备掺杂电气石和稀土La的TiO2复合光催化薄膜样品。用正交试验方法对影响该薄膜样品光催化性能的制备工艺进行优化,并通过紫外可见光谱对复合薄膜样品的吸收光谱进行分析。结果表明,掺杂稀土元素La可使TiO2的光吸收范围发生红移,掺杂电气石将增强La/TiO2光吸收强度,T/La/TiO2复合光催化薄膜最佳制备工艺为:La3+掺杂量为1.2%(wt,下同)、电气石掺杂量为0.8%、焙烧温度为500℃、焙烧时间为1.5h、负载次数2次,样品的的甲醛降解率可达82.5%。     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.