汤金钢、刘道新、唐长斌 等 4 位作者2013-01-01金属热处理
为改善钛合金室温和高温摩擦学性能,分别采用锆-氮离子共渗(Zr+N)与离子渗锆后渗氮(Zr/N)两种工艺在TC4钛合金表面制备锆-氮改性层。利用球盘磨损试验机对比研究了两种Zr-N改性层在室温和600℃高温环境下的摩擦学性能。结果表明,两种工艺制备的Zr-N改性层均由ZrN相组成,Zr/N改性层还包含少量TiN相和较厚的Zr-Ti固溶体,两种等离子表面合金化层均使钛合金表面硬度显著提高。Zr/N改性层比Zr+N离子共渗层表面硬度更高,渗层更深,表面承载能力更强。室温和600℃高温下,Zr/N改性层磨损率比TC4钛合金基材分别降低43倍和21倍;Zr+N共渗改性层磨损率比TC4钛合金基材分别降低24倍和5倍。
Advanced Surface Polishing TechniquesMetal and Thin Film MechanicsAdvanced ceramic materials synthesis
华云峰、潘伟、李争显 等 6 位作者2013-01-01稀有金属材料与工程
采用Lu2O3/TiO2/Nb2O5作为ZrO2热障涂层材料的稳定剂,研究Lu2O3/TiO2/Nb2O5共稳定ZRO2(15%LTNSZ)热障涂层材料在900℃、40m01%V2O5+60m01%Na2S04熔盐中的热腐蚀行为。结果表明:8%YSZ热障涂层材料热腐蚀2h后,t相ZrO2全部相变为m相ZrO2,热腐蚀产物为尺寸较大的YVO4晶体;15%LTNSZ热障涂层材料热腐蚀20h后,m相ZrO2的比例仅为5.5%,热腐蚀产物为尺寸较小的LuVO4晶体。与Y2O3稳定剂相比,Lu2O3/TiO2/Nb2O5稳定剂使ZrO2在40mol%V2O5+60mol%Na2S04熔盐中的抗热腐蚀性能提高1个量级以上。
Radioactive element chemistry and processingNuclear materials and radiation effectsNuclear Materials and Properties
郑龙江、李雅新、刘海龙 等 5 位作者2013-01-01Acta Scientiarum Naturalium Universitatis Sunyatseni
采用高温固相法制备了Tm3+,Yb3+共掺CaWO4多晶材料.980 nm二极管激光器激发下,在可见区获得了1G4→3H6,1G4→3H4,3F2,3F3→3H6跃迁产生的上转换荧光.讨论了Yb3+离子浓度的变化对Tm3+的上转换发光强度的影响,同时根据荧光强度比的方法研究了689和705 nm红色上转换荧光在313—773 K范围内的温度特性.结果表明:基于Tm3+,Yb3+共掺CaWO4多晶材料的红色上转换荧光可以实现温度监测,其测温的最大灵敏度值为5.7×10 4K 1,相应的测量温度为458 K.
Photorefractive and Nonlinear OpticsSolid State Laser TechnologiesLuminescence Properties of Advanced Materials
Daeseo Koo、Jungmin Lee、Jong‐Chul Park 等 4 位作者2013-01-01OpenAlex
The absorption between hydrogen isotopes and storage materials (ZrCo or uranium) is an exothermic reaction. The exothermic reaction characteristics upon the hydriding of hydro- gen isotopes with ZrCo and depleted uranium (DU) were investigated. The temperature increase due to a hydriding exothermic reaction during the…
Nuclear Materials and PropertiesNuclear reactor physics and engineeringHydrogen Storage and Materials
段兴凯、胡孔刚、满达虎 等 6 位作者2013-01-01Acta Scientiarum Naturalium Universitatis Sunyatseni
采用真空熔炼及热压方法制备了K和Al共掺杂P型Bi0.5Sb1.5Te3热电材料。XRD分析结果表明,K0.04Bi0.5Sb1.5-x Alx Te3块体材料的XRD图谱与Bi0.5Sb1.5Te3的图谱完全对应,SEM形貌分析表明材料具有一定的层状结构和微孔。K和Al共掺杂提高了Bi0.5Sb1.5Te3在室温附近的Seebeck系数。除了K0.04Bi0.5Sb1.34Al0.12Te3样品的300K和400K以上的高温区,以及共掺杂样品的500K高温附近之外,K和Al共掺杂均使Bi0.5Sb1.5Te3材料的电导率降低。在300~500K温度范围内,K0.04Bi0.5Sb1.42Al0.04Te3样品的热导率均小于Bi0…
Advanced Thermoelectric Materials and DevicesAdvanced Thermodynamics and Statistical MechanicsThermal properties of materials
刘冲 LIU Chong、Xu Li、Wei Wei 等 6 位作者2013-01-01Acta Scientiarum Naturalium Universitatis Sunyatseni
采用高温固相法制备了系列蓝绿色Ca7Si2O8Cl6:Eu2+荧光粉,并对样品进行了XRD分析、发光性能和色参数的测试。结果表明,合成的样品为单相Ca7Si2O8Cl6;在紫外光激发下,样品呈现一个不对称宽峰结构;分别监测这个发射峰,得到一个较宽的激发谱。同时研究了在样品中分别加入Sr2+和F-后荧光粉的激发和发射光谱,得到了这些离子的加入量与样品发光性能的关系,并探究了发生该现象的原因。结果表明,加入Sr2+或F-后可以得到较好的蓝绿色发光材料。
Pigment Synthesis and PropertiesSolid State Laser TechnologiesLuminescence Properties of Advanced Materials
Gregory J. Szulczewski2013-01-01OpenAlex
Historically ð polymers ð have ð been ð used ð as ð structural ð components ð and ð textile ð fibers ð because ð they ð are ð lightweight ð and ð corrosion ð resistant. ð Until ð the ð 1970's ð polymers ð were ð thought ð to ð be ð electrical ð insulators. ð However, ð the ð seminal ð work ð of ð Shirakawa, ð MacDiarm…
Advanced Sensor and Energy Harvesting MaterialsConducting polymers and applicationsAdvanced Thermoelectric Materials and Devices
박형규2013-01-01OpenAlex
비철금속은 종류가 많아서 비철금속 전반에 걸친 리싸이클링 현황을 파악하기에는 분량이 너무 방대하기 때문에 개별 금속에 대해서는 리싸이클링 현황이 조사 보고되었지만 비철금속 스크랩 전반에 대해서는 통계자료가 아직 공식적으로 발표되지 않고 있다. 본 고에서는 상용 비철금속인 동, 알루미늄, 아연, 연, 니켈 및 마그네슘에 대하여 최근 몇년(2010-2012년) 간의 국내 수요, 생산량과 스크랩에 대한 리싸이클링 현황을 조사하고 이를 토대로 리싸이클링율을 추정하였다. 【Since there are many kinds of non-ferrous metal, it is di…
Bauxite Residue and UtilizationExtraction and Separation ProcessesMetallurgy and Material Science
游海萍、汪婷、徐国忠 等 4 位作者2013-01-01福建师范大学学报:自然科学版
研究了投加不同质量浓度纳米二氧化钛(nTiO2)颗粒对卡洲萍(Azolla aroliniana)同步富集混合溶液中Cu(Ⅱ)和Cr(Ⅵ)的影响.结果显示,卡洲萍同步富集Cu(Ⅱ)和Cr(Ⅵ)时,对Cu(Ⅱ)和Cr(Ⅵ)的富集量分别为12.02 mg·g-1和4.17 mg·g-1,对Cu(Ⅱ)的富集效率明显高于Cr(Ⅵ).当nTiO2的投加量为300 mg·L-1时,卡洲萍对Cu(Ⅱ)和Cr(Ⅵ)的富集量分别下降50.8%和14.3%.红外分析显示卡洲萍在nTiO2存在的条件下可以诱导产生更多的蛋白质,核酸等物质,这些物质可以增强植物的抗逆性,以减轻重金属毒害;SEM和EDS图谱表明Cu(Ⅱ)和Cr(Ⅵ)吸附在nTiO2颗粒上,…
Heavy metals in environmentGeochemistry and Elemental AnalysisNanoparticles: synthesis and applications
李胜利、朱新德、孙良成 等 4 位作者2013-01-01Acta Scientiarum Naturalium Universitatis Sunyatseni
用乙二胺四乙酸(EDTA)作为辅助络合剂与Ca^2+单独络合,然后再与柠檬酸络合剂混合,解决了柠檬酸络合剂与Ca2+络合能力差的问题,实现了La^3+、Cr^3+、Ca^2+三种离子在溶胶中的均匀稳定络合。利用红外光谱、热分析、X射线衍射、透射电镜对凝胶结构、热分解过程、粉体物相等进行了表征。结果表明,该工艺得到的干凝胶在500℃煅烧就可以转变为纯度较高的La0.9Ca0.1CrO3相,比单一柠檬酸体系的合成温度低200℃左右。另外,该体系中钙掺杂起到抑制铬酸镧中Cr元素挥发的作用。
Thermal and Kinetic AnalysisLayered Double Hydroxides Synthesis and ApplicationsPigment Synthesis and Properties
Tongbo Qiang、高丽、谭志坚 等 6 位作者2013-01-01Acta Scientiarum Naturalium Universitatis Sunyatseni
采用高温固相法制备了MgB407:Tm,Mn磷光体材料,测量了热释光发光曲线和热释光三维光谱以及剂量响应曲线。其主发光峰温度约为400℃,发光波长455rim。MgB407:Tm,Mn主发光峰面积比LiF:Mg,Ti高6.2倍,具有很好的热稳定性,在0.1-2000Gy范围内具有良好的线性.超线性剂量响应。
Boron and Carbon Nanomaterials ResearchCrystal Structures and PropertiesSuperconductivity in MgB2 and Alloys
涂娜、江向平、李小红 等 5 位作者2013-01-01Acta Scientiarum Naturalium Universitatis Sunyatseni
采用传统固相法制备了(1-x)Bi4Ti3O12-xSrBi2Nb2O9(BIT—SBN,x=0,0.025,0.050,0.100,0.150,0.200)铋层状无铅压电陶瓷。系统研究了SrBi2Nb2O9掺杂对Bi4Ti3O12基陶瓷物相结构、微观结构以及jie电性能的影响。结果表明:所有陶瓷样品均为单一的铋层状结构;当SBN掺量为0.100时,样品具有最佳的电性能:d33=21pC/N,相对密度P=98.1%,机电耦合系数kp=8.26%,er=220,介电损耗tanδ=0.29%,剩余极化强度Pt=9.128μC/cm^2,Tc=594℃。同时,SBN的引入增强了样品的抗老化性和热稳定性。
Polyoxometalates: Synthesis and ApplicationsTransition Metal Oxide Nanomaterials
Zoran Klanfar2013-01-01OpenAlex
Priprema pacijenta te programiranje, vođenje i nadgledanje svih radioloskih i nuklearno-medicinskih dijagnostickih metoda. Upotreba radioloskog pribora i kontrastnih sredstava. Rezultati prikazivanja i ocjena vrijednosti snimke.
Nuclear Physics and ApplicationsGraphite, nuclear technology, radiation studies
钟红梅、刘茜、周遥 等 5 位作者2013-01-01Acta Scientiarum Naturalium Universitatis Sunyatseni
采用高温固相法合成了不同浓度Ce^3+掺杂的AlON荧光粉.通过X射线和扫描电镜分析了荧光粉的物相和显微结构,且利用荧光光谱仪测试了AlON:Ce^3+荧光粉的发光光谱.结果表明,荧光粉在305nm紫外激发下发射390nm为中心的蓝光.温度依赖荧光谱测试发现,AlON:Ce^3+荧光粉在150℃下发射强度能保持室温发射强度的86%.因此,该荧光粉是大功率白光发光二极管用最佳荧光粉的候选材料之一.
Luminescence Properties of Advanced MaterialsEnergetic Materials and CombustionPhotorefractive and Nonlinear Optics
Jixin Li、Xiaohui Song、Zhiming Wang2013-01-01OpenAlex
Phenanthroimidazole and its derivatives have attracted more and more attention in preparing bipolar and high-efficiency saturated blue emitters due to their excellent thermal properties. To discuss the effect on the glass transi- tion temperature and thermal decomposition temperature originating from the chemical stru…
Organic Light-Emitting Diodes ResearchConducting polymers and applicationsOrganic Electronics and Photovoltaics
Ana Akrap、Alberto Ubaldini、E. Giannini2013-01-01arXiv (Cornell University)
We study the temperature and composition dependence of the resistivity, (T ), and thermopower, S(T ), for a series of layered bismuth chalcogenides Bi2Te3 xSex. S(T ) can be semi-quantitatively described by a simple model for an extrinsic semiconductor. By substituting Se for Te, the Fermi level is tuned from the vale…
Advanced Thermoelectric Materials and DevicesIron-based superconductors researchTopological Materials and Phenomena
陈兰钗、方扬、靳艳玲 等 7 位作者2013-01-01OpenAlex
为开发高效去除重金属铅(Pb2+)污染的生物吸附剂,以浮萍(Lemna aequinoctialis)干粉为吸附剂原料,通过单因素实验研究了该吸附剂吸附Pb2+的主要影响因素;利用吸附动力学方程和等温吸附方程对实验数据进行拟合;并采用红外光谱分析仪研究了吸附前后吸附剂表面的化学基团变化.结果表明,对吸附效果影响显著的因素有溶液初始pH值、吸附剂颗粒大小和Pb2+初始浓度;参与吸附Pb2+的基团可能是吸附剂所含糖类中的羟基及酰胺中的氨基;其吸附行为符合准二级动力学方程,相关系数R2为0.999 95,k2为3.65 g min-1 mg-1;等温吸附曲线符合Freundlich方程,浮萍对Pb2...
Adsorption and biosorption for pollutant removalEnvironmental Chemistry and AnalysisNanoparticles: synthesis and applications
陶雪云、Hui Xu、谭晓华 等 7 位作者2013-01-01稀有金属材料与工程
采用熔体快淬法制备成分为Nd10Fe80-xNbxB10(x=0~6)的非晶条带,退火处理后得到纳米晶复合永磁合金。利用振动样品磁强计(VSM)分析该合金系的磁性能和软、硬磁性相间的交换耦合作用。结果表明,适量的Nb元素的添加可以使软、硬磁性相的晶粒细化,从而有效地增强合金中软、硬磁性相间的交换耦合作用,进而提高合金的综合磁性能。当Nb含量为4at%时,制得的合金条带具有最佳的综合磁性能:Hcj=936.02kA/m,Br=0.91T,(BH)max=125.86kJ/m3。
Metallic Glasses and Amorphous AlloysMagnetic Properties of AlloysMagnetic Properties and Applications
Nastaran Ghorbanian Farahabadi2013-01-01uO Research (University of Ottawa)
This thesis focuses on the synthesis of mononuclear Co and Fe complexes of defined geometry. The goal is to explore the effects of metal coordination geometry on single molecule-magnets (SMM) through peripheral ligand modification with the bis(imino)pyridine ligand. Chapter 1 presents fundamental concepts that are use…
Magnetism in coordination complexesMagnetic properties of thin films
彭晓东、李俊辰、李文娟 等 5 位作者2013-01-01稀有金属材料与工程
采用光学显微镜、SEM扫描电镜、XRD以及力学性能和电化学测试等手段,研究了不同Y含量对Mg-9Li-3Al合金组织、力学性能和腐蚀性能的影响.结果表明:随着Y的添加,α相的形貌逐渐发生变化,其体积分数也逐渐减少,并形成新的Al2Y相,Al2Y主要分布在β相和α相内部.当Y的添加量为1.6%(质量分数)时,材料的抗拉强度达到最大190.2 MPa;当Y含量为2.0%时,材料的最大延伸率为19.3%.在Y含量低于1.2%时,材料的抗腐蚀性能随Y含量的增加而减小,超过1.2%后,随着Y含量的增加而增加.
Magnesium Oxide Properties and ApplicationsMagnesium Alloys: Properties and ApplicationsHydrogen embrittlement and corrosion behaviors in metals