TiO2/PLCL可降解聚合物纳米复合材料的制备及形状记忆性能

制备TiO2/聚(L-丙交酯-ε-己内酯)(PLCL)纳米复合材料并研究其性能.采用ε-己内酯开环聚合法对TiO2纳米粒子进行表面改性,通过傅立叶变换红外光谱(FTIR)、热重分析(TGA)和透射电子显微分析(TEM)对聚己内酯(PCL)接枝改性后的TiO2纳米粒子(g-TiO2)进行表征.g-TiO2纳米粒子能均匀地分散在三氯甲烷溶液中.采用溶液浇铸的方法成功地制备了TiO2/PLCL复合材料.研究g-TiO2纳米粒子的含量对材料力学性能和形状记忆性能的影响.结果表明,5％ g-TiO2/PLCL复合材料的力学性能有显著的提高,与纯PLCL相比,抗拉强度提高了113％,伸长率提高了11％.含有g-TiO2纳米粒子的复合材料的形状记忆性能优于纯PLCL.g-TiO2纳米粒子具有物理交联作用,有助于形状记忆效应的提高.     

石墨烯增强铜基复合材料的制备及其微观组织与性能研究

利用分子级混合法在不同溶液水热温度(40、60、80、100℃)下制备还原氧化石墨烯(RGO)/铜纳米复合材料。通过原子力显微镜(AFM)、扫描电镜(SEM)、拉曼(Raman)光谱、X射线衍射仪(XRD)对不同溶液反应温度下制备的复合材料粉末进行微观组织分析,并对烧结后样品进行导电导热及力学性能研究以确定制备RGO/Cu纳米复合材料相对合适的溶液反应温度。结果表明,当溶液反应温度为80℃时,铜镀层能够连续致密覆盖在RGO表面,有效阻止其团聚并获得良好的界面结合。制备出1.0%(体积分数)RGO含量的复合材料的硬度比纯铜提高了90%,抗拉强度比纯铜提升了28.8%,导电导热性能也达到最佳值(热导率350W·m-1·K-1,电导率达89%IACS)。过高的溶液反应温度不利于复合材料获得良好的物理力学性能。     

柠檬酸络合sol-gel法原位合成rGO-La~(3+)/TiO_2及其光催化性能

首先采用Hummers法制备氧化石墨烯(GO),然后用柠檬酸络合溶胶-凝胶法原位合成GO-La~(3+)/TiO_2,再经硼氪化钠还原得到石墨烯-La~(3+)/TiO_2(rG0-La~(3+)/TiO_2)复合材料;利用X射线衍射(XRD)、透射电镜(TEM)、荧光光谱(PL)对其进行表征分析。研究了GO加入量对复合材料光催化效率的影响及复合光催化剂投入量对甲基橙降解率的影响。结果表明:柠檬酸络合法可以有效改善纳米La~(3+)/TiO_2在rGO表面的分散情况;rG0-La~(3+)/TiO_2复合光催化剂的光催化活性明显高于La~(3+)/TiO_2,GO加入量对复合材料光催化性能影响很大;降解甲基橙时,复合光催化剂最佳投入量为0.10g。     

Ag-TiO2复合纳米颗粒的自组装法制备及其光催化性

采用空气-水界面自组装法制备TiO2纳米粒子,将其放入AgNO3溶液中浸泡,后在较低温度下进行热处理(400℃),获得Ag-TiO2复合纳米颗粒.利用X射线衍射(XRD)仪、扫描电镜(SEM)、透射电镜(TEM)、紫外可见光谱(UV-vis)等分析测试手段进行表征.结果表明:复合粒子可以显著提高TiO2颗粒光催化活性.以甲基橙为模拟污染物,经过光催化试验,证实复合纳米粒子具有较好的光催化活性,降解率达到96.25％.     

TiO_2/多孔g-C_3N_4纳米复合材料制备及性能研究

以硫酸钛为钛源,采用水热法成功制备了TiO_2纳米颗粒均匀负载于多孔g-C3N4表面的复合光催化材料。利用X射线衍射(XRD)、红外光谱(FT-IR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM),紫外-可见漫反射(DRS)和荧光光谱(PL)等手段对样品进行表征,并以甲基橙为目标分解物考察了样品的可见光催化活性。结果表明:质子化作用是形成多孔结构的主要原因,且多孔性与Ti(SO4)2浓度高度相关。多孔结构的产生显著提高了复合材料对甲基橙的吸附能力。另一方面,TiO_2在g-C3N4表面原位形核生长,形成纳米结,光生电子-空穴对可通过纳米结有效分离,从而提高复合材料量子效率,增强光催化活性。不过,负载TiO_2后,复合材料的可见光响应特性有所降低。综合来看,当TiO_2与g-C3N4摩尔比为1/3时,所得复合材料光催化活性最强,降解甲基橙的一级反应速率常数为单一g-C3N4的11.1倍。     

Ce1-xMnxO2-δ-凹凸棒石(Ce1-xMnxO2-δ-ATP)纳米复合材料的制备及催化性能

采用共沉淀法制备Ce1-xMnxO2-δ-凹凸棒石(Ce1-xMnxO2-δ-ATP)纳米复合材料,考察不同Mn掺杂量和负载量对纳米复合材料结构和性能的影响;采用X射线衍射仪(XRD)、透射电子显微镜(TEM)和Raman光谱仪等对复合材料的微观结构等进行表征.结果表明:当负载量为50％（质量分数）时,Ce1-xMnxO2-δ颗粒在ATP表面分散情况较好,晶粒为7～11 nm;当x≤0.2时,Mn的掺杂未使CeO2的萤石结构发生变化,活性组分以固溶态存在于载体表面,Ce0.8Mn0.2O2-δ-ATP复合材料对苯酚的催化降解效果较好,其化学需氧量(COD)去除率可达97％,优于单一ATP和CeO2材料的催化降解效果;当x＞0.2时,复合材料中出现Mn2O3相,其催化性能降低.     

石墨相碳化氮复合材料的制备及其可见光光催化性能的研究

目的提高半导体石墨相氮化碳(g-C_3N_4)的光催化性能。方法通过Hummers法和半封闭一步热裂解法制备了氧化石墨烯(GO)和g-C_3N_4,再分别利用溶剂热法、热缩聚法和浸渍化学还原法制得相应的TiO_2/g-C_3N_4、ZnO/g-C_3N_4、RGO/g-C_3N_4复合材料。采用X-射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、紫外-可见漫反射吸收光谱(UV-Vis DRS)和傅里叶变换红外光谱(FT-IR)等手段对复合材料进行表征,并以降解罗丹明B(Rh B)来评价其在可见光下的光催化性能。结果以尿素与三聚氰胺的混合物为原料通过热裂解法制备的g-C_3N_4,比使用纯尿素制备的g-C_3N_4具有更优的催化效果。TiO_2、ZnO、RGO的引入提高了g-C_3N_4的光催化活性,Rh B的降解率分别为95.6%、95.0%、78.1%。RGO质量分数为2.0%时,RGO/g-C_3N_4复合材料的催化效率最高。结论通过g-C_3N_4特殊的能带调控优势与TiO_2、ZnO、RGO的协同作用,提高了复合材料在可见光区的吸收强度和电子传导能力,进而提高了在可见光下的光催化性能。     

石墨烯/银纳米复合材料的制备及抗菌性能研究

采用改进的Hummers法制备氧化石墨(GO),加入一定量的聚乙烯亚胺和硝酸银(PEI-Ag+)配位复合物,通过自组装法组装,利用硼氢化钠的还原性,制备石墨烯/银纳米复合材料。用紫外可见吸收光谱(UV-Vis)、红外吸收光谱(FT-IR)、X射线衍射(XRD)、循环伏安法(CV)、扫描电镜(SEM)、拉曼光谱(Raman)等手段对所制备的石墨烯/银纳米复合材料进行表征。以金黄色葡萄球菌和大肠杆菌为模型对纳米复合材料的抗菌性能进行研究。结果表明:银纳米粒子负载在石墨烯表面形成石墨烯/银纳米复合物材料,石墨烯/银纳米复合材料对金黄色葡萄球菌和大肠杆菌生长具有较好的抑制作用,且抗菌性能稳定。当石墨烯/银纳米复合材料浓度为4和15 mg/m L时,分别对金黄色葡萄球菌和大肠杆菌的抑菌效果好。     

纳米复合材料CdS/TiO2NTs的制备及光催化产氢活性

通过离子交换和沉淀反应制备纳米复合材料CdS/TiO2NTs.采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、漫反射紫外-可见吸收光谱(DRUVAS)、荧光光谱(FES)、X射线荧光分析(XRF)等手段对该复合材料的结构进行表征.SEM结果表明:钛酸盐纳米管的形成经由TiO2颗粒-片状的钛酸盐-卷曲的钛酸盐纳米管的自组装过程.XRD、DRUVAS、FES和FES结果表明:平均粒度大约 8 nm 的六方相CdS均匀的负载于锐钛矿型TiO2纳米管表面,其吸收边扩展到可见区.与TiO2纳米管及TiO2粉末相比,CdS/TiO2NTs 纳米复合材料展示了较高的可见光催化分解水产氢活性.     

对氨基苯甲酸在银纳米粒子二维有序阵列中的光谱研究

用氢气还原氧化银的方法合成了粒径约为100 nm的银纳米粒子,在表面经聚乙烯吡啶修饰的玻璃片上以自组装的方式构筑了银纳米粒子的单层二维有序阵列。经对氨基苯甲酸修饰后,进而又构筑了银纳米粒子的双层二维有序阵列。采用透射电镜(TEM)、扫描电镜(SEM)和紫外-可见光谱(UV-Vis)进行了表征。二维有序阵列的表面增强拉曼光谱研究表明:对氨基苯甲酸在银粒子上垂直吸附,电磁场增强对表面增强拉曼效应起主导作用。     

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.