铁氮共掺杂纳米TiO2的水热法制备及其在可见光下抗菌性能的研究

以硫酸氧钛为前驱体，硝酸铁和盐酸胍作为掺杂的铁源和氮源，采用水热法制备了铁氮共掺杂纳米TiO2粉体。利用XRD、BET对样品进行表征，研究了掺杂后TiO2粉体的晶型、粒径、比表面积等性能。结果表明，所制备的共掺杂TiO2粉体呈黄色，均为锐钛矿相TiO2，经谢尔公式计算其粒径约为10nm，比表面积分布为（135～150）m^2／g。采用紫外．可见光漫反射光谱对样品进行表征，结果表明经过铁氮共掺杂改性后的TiO2具有很强的紫外线的吸收能力，并实现了良好的可见光响应。采用菌落计数法进行了样品抗菌性能的研究，在可见光照射下样品对大肠杆菌表现出良好的杀灭性能。     

单分散纳米TiO2光催化剂的水解-溶胶制备法

以Ti(SO4)2为原料，在一定温度下直接水解、胶溶、加入晶种、熟化，制备出单分散性、热稳定性良好、平均粒径在22nm左右、比表面积在80m^2／g以上的TiO2纳米微粒。研究了Ti(SO4)2浓度、水解时间及晶种对纳米微粒粒径的影响。对样品进行了TG-DTA，XRD和SEM分析。结果表明：样品经真空冷冻干燥后，TiO2粉体主要为锐钛矿型，且随焙烧时间增加和温度升高，其金红石型含量显著增多，粉体粒径也有一定增大，但在不同的温度区间粒径增长速率有较大的区别。     

二氧化钛纳米管的合成及其表征

采用水热合成法，以TiO2粉体和NaOH为原料，成功地制备出了TiO2纳米管。用XRD，SEM，HRTEM，紫外吸收光谱分析仪和光谱辐射分析仪等手段对纳米管进行微观形貌、光学性能的表征，并探讨了其生长机理。结果表明，所得产物为锐钛矿和金红石混晶型TiO2纳米管，管壁为多层，管的外径分布在10nm～50nm，长度可达几微米甚至十几微米，呈开口状；TiO2纳米管的生长机理符合3-2-1D的生长模型，其紫外吸收光谱和光致发光光谱相对于原料粉均呈现出蓝移现象，光致发光光谱显示TiO2纳米管在可见光区的发光强度明显增强。     

负载型TiO2纳米薄膜电极光电催化氧化甲醇的研究

介绍了负载不同晶型TiO2薄膜电极的制备，并研究了聚乙二醇加入量、活化条件等对不同晶型、不同形貌、不同粒径纳米TiO2薄膜电极的光电催化活性的影响。结果表明：聚乙二醇加入量有一最佳值；且纳米级锐钛矿型TiO2和金红石型TiO2分别经600℃和400℃煅烧后，光电催化性能最好；粒径越小催化活性越高．当粒径小于25nm时，可显示出量子尺寸效应。     

纳米二氧化钛表面改性及其在聚氨酯涂层中的分散性质

采用长链烷烃和微胶囊方法对纳米TiO2(锐钛型,粒径20nm) 进行表面改性,利用傅里叶红外光谱(FTIR)和热重分析(TGA)分别研究了改性纳米粉体的表面化学结构及接枝率,结果表明:改性纳米TiO2粉体表面成功接枝了高分子聚合物,接枝率分别为5%和12%.将改性纳米TiO2粉体(质量分数为1%～3%)与双组分聚氨酯涂料进行复合,制备了纳米TiO2/聚氨酯复合涂料,并利用扫描电子显微镜(SEM)对纳米复合涂层进行了微观检测,结果表明:微胶囊改性的纳米TiO2在涂层中的分散性最好.     

高能球磨制备纳米TiO2/纳米晶Cu超细复合粉体

采用高能球磨法制备了TiO2/Cu复合粉体并采用X射线衍射(XRD)、显微图像分析仪等测试分析方法,对球磨过程中复合粉末相结构、组织形貌和粒度分布的变化进行了研究.结果表明:球磨24 h后可形成纳米TiO2粉体/纳米晶Cu复合粉体,Cu粉晶粒达59 nm;随着球磨时间的增加,纳米TiO2团聚体逐渐嵌入Cu颗粒中,被很好地分散开,呈弥散分布;同时复合粉体粒度细化到300 nm以下,比表面积大大增加,粉体也由球形逐渐地过渡到多角形.     

钛醇盐水解-沉淀法制备纳米二氧化钛粉体(英文)

以钛酸四丁酯为原料,采用水解-沉淀法制备TiO2纳米粉体,利用BET、XRD、IR、SEM和激光粒度分析仪等测试手段对制备TiO2粉体晶粒大小、粉体的粒度分布情况等进行了研究,并讨论原料配比,烧成温度,pH值与晶粒大小,物相组成等之间的关系。结果表明:在600°C到800°C之间,TiO2粉体由锐态矿转变为金红石,经800°C加热2h的物相主要为金红石,粉体呈类球形;pH为3.03,n(H2O):n[Ti(C4H9O)4]=30,400°C热处理2h后制备的TiO2粉末晶粒平均尺寸为80nm,粉体的平均粒度为580nm,比表面积为117.2631m2/g。     

HF-PCVD法TiO2纳米晶的粒径与晶型控制

以TiCl4和O2为反应体系，采用高频等离子化学气相沉积(HF-PCVD)法制备了晶化完整的锐钛和金红石混晶型TiO2纳米晶，球形体的晶粒分散性良好，分布较为均匀：研究了控制粒径大小和晶相组成的关键反应条件。XPS，TEM，XRD结果显示：增加TiCl4进料量、延长停留时间均利于锐钛相向金红石相转化，但粒径有所增大：添加A1C13使金红石相含量较未掺杂时有较大幅度提高，且粒径随掺铝量增加而减小。本实验条件下，TiO2纳米晶的粒径为25nm～60nm，金红石相含量在12．O％～53．6％间可控。     

Cu基电触头用掺杂SnO2纳米粉体的制备

利用溶胶-凝胶工艺制备了Cu基电触头用TiO2掺杂SnO2纳米粉。实验时,首先采用TG-DSC方法对掺杂SnO2前驱体在升温过程中的转变过程进行了分析,然后采用XRD对不同温度焙烧所得掺杂SnO2粉体进行了物相分析、颗粒粒径计算,采用TEM对掺杂SnO2粉体的微观形貌进行了观察,最后通过分析掺杂SnO2粉体晶格参数d值的变化对粉体的掺杂效果进行了评估。结果表明:通过所述工艺成功实现了TiO2对纳米SnO2的掺杂,500℃焙烧所得掺杂SnO2为圆球形,粒径约为10 nm,较好地满足Cu基电触头材料使用的需求。     

固相反应法合成BaTiO3粉末的相变和微观结构的转变

以国产亚微米级BaCO3和TiO2为原料,采用砂磨固相法合成粒径小、四方性高的BaTiO3粉体,同时研究煅烧温度、升温速率及保温时间对BaTiO3平均粒径和四方性的影响。结果表明,通过固相反应合成BaTiO3的反应机理可分为两个阶段:当煅烧温度低于900℃时,BaCO3和TiO2首先形成立方相的BaTiO3,当煅烧温度升至900℃时,立方相BaTiO3开始向四方相转变。在升温速率为5℃/min,煅烧温度为900℃保温5 h时,制备出粒径为180.7 nm,四方性(c/a)为1.0086的超细BaTiO3粉体。该工作为制备超薄层MLCC用高性能BaTiO3粉体提供了较好的研究思路。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

The Mirror with Patterns of Auspicious Animals and Grapes——Exquisite cast mirror and the technology of surface tin-enrichment by rubbing-in and infiltration of tin-rich powder

<正>Bronze mirrors were used by the Chinese people before the introduction of the glass mirror.Only after it was replaced by the glass mirror did the bronze mirror gradually retreat from people's lives.Different styles of bronze mirrors were made in different historical periods,particularly in the Warring States Period,the Han and Tang Dynasties,which were the three peaks of the development of bronze mirror arts in ancient China.The casting techniques were exquisite.The surface of the bronze mirror was smooth and bright enough to reflect one's image,and there were scarcely any casting defects on the mirror surface.On the back of the bronze mirror,there were rich depictions of Arts and Humanities,and the ornamentations were also     

The 9th China International Diecasting Congress & Exhibition

The 9th China International Diecasting Congress ＆ Exhibition was held on July 22-24, 2014 at Shanghai New International Expc Centre. This exhibition was the most successful over the years, with over 6890 visitors and 155 exhibitors, and the exhibition area increased by 30% from 9,500 square meters in 2012 to 12340 square meters. Die casting enterprises from a total of 24 countries and regions, including China mainland, Chinese Taiwan and Hong Kong, South Korea, Japan, Germany, India, Thailand, Malaysia, the United States, Russia, Australia, Iran, Ukraine, Brazil, Colombia, Singapore, Austria, Canada, Croatia, France, Turkey, United Kingdom, Vietnam, attended the congress and exhibition.     

Introduction of the Fluid Control Engineering Institute of Kunming University of Science and Technology

正The Fluid Control Engineering Institute of Kunming University of Science and Technology was set up in 1996.The researches of institute concentrate on electro-hydraulic(pneumatic)servo/proportional control and hydromechatronics.The Institute is committed to research and development of electro-hydraulic control of high-end technical equipment in ferrous metallurgy refining produc-     

RARE METALS Volume Contents

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Antimony Induced Crystallization of Amorphous Silicon

Antimony induced crystallization of PVD (physics vapor deposition) amorphous silicon can be observed on sapphire substrates. Very large crystalline regions up to several tens of micrometers can be formed. The Si diffraction patterns of the area of crystallization can be observed with TEM (transmission electron microscopy). Only a few and much smaller crystals of the order of 1μm were formed when the antimony layer was deposited by MBE (molecular beam epitaxy) compared with a layer formed by thermal evaporation. The use of high vacuum is essential in order to observe any Sb induced crystallization at all. In addition it is necessary to take measures to limit the evaporation of the antimony.     

A CUMULATIVE FATIGUE DAMAGE RULE UNDER THE ALTERNATIVE OF CORROSION OR CYCLIC LOADING

Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted.