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1.
采用高温固相法制备SrAl2O4:Eu^2+,Dy^3+长余辉发光材料。借助材料的激发光谱、发射光谱和X射线衍射,分析研究掺杂B对SrAl2O4:Eu^2+,Dy^3+发光材料发光性能的影响及合适的加入量。结果表明:B的加入量影响着发光材料的发光性质,B的最佳加入量为58%。  相似文献   

2.
采用燃烧合成方法,在600℃温度条件下,首次合成镱/钕掺杂的SrxCa1-xAl2O4:Eu^2+,Dy^3+长余辉光致发光材料。通过X射线衍射和发射光谱分析,结果表明镱或钕的掺杂几乎没有改变材料的晶体结构以及Eu^2+发光中心电子的4f^65d→4f^7的跃迁环境。余辉衰减特性曲线显示,与SrAl2O4:Eu^2+,Dy^3+相比较,SrAl2O4:Eu^2+,Dy^3+,Yb^3+的初始发光亮度有明显提高,余辉时间略微减小,而SrAl2O4:Eu^2+,Dy^3+,Nd^3+的初始亮度却大幅度的降低,同时余辉时间也降低。热释发光实验的进一步研究发现,不同的发光体存在不同深度的陷阱能级,而且陷阱能级的深度与余辉时间相对应。  相似文献   

3.
不同沉淀剂下采用均相沉淀法制备出掺杂不同金属离子(K^+,Mg^2+,Ba^2+)的Y2O3:Eu^3+荧光粉。通过XRD、IR、激发与发射等技术研究了材料的结构与发光性能,考察了沉淀剂、掺杂的金属离子种类对Y2O3:Eu^3+发光材料的结构和发光性能的影响。结果表明:用尿素作沉淀剂制备的发光性能明显强于用草酸作沉淀剂的Y2O3:Eu^3+荧光粉。其中,在草酸系列中,同时掺杂K^+离子能显著增强Y2O3:Eu^3+的发光强度,而掺杂Mg^2+,Ba^2+离子则会减弱其发光强度;而在尿素系列里,掺杂离子都会增强样品的发光强度。  相似文献   

4.
沈毅  李明  于涛 《材料导报》2006,20(F05):341-344
用草酸盐共沉淀法制备了SrAl2O4:Eu^2+,Dy^3+发光粉体,用差热分析仪、X-射线衍射仪、扫描电镜和荧光分光光度计对制备产物进行了测试分析,并对烧成温度,Dy^3+、H3BO3掺杂对荧光体发光特性的影响进行了讨论,确定了草酸盐共沉淀法的最佳烧成温度为1200℃,Dy^3+最佳掺杂摩尔分数为0.002,硼酸为0.3。  相似文献   

5.
以高纯度的硝酸锶、硝酸钙、硝酸铝和稀土氧化物为原料,以硼酸为助溶剂,采用燃烧法在600℃的低温条件下合成SrxCa1-xAl2O4:Eu^2+,Dy^3+(x=0、0.6、1.0)长余辉发光材料。光致发光光谱分析表明样品发光光谱均为宽带谱,样品CaAl2O4:Eu^2+,Dy^3+和样品SrAl2O4:Eu^2+,Dy^3+的发射谱峰值分别位于442和511nm左右,样品Sr0.6Ca0.4Al2O4:Eu^2+,Dy^3+有两个发射峰,分别位于442和507nm左右。余辉检测结果表明:样品余辉衰减都是由初始的快衰减过程和其后的慢衰减过程组成,但不同样品衰减快慢不同。利用热释光检测结果对样品中存在的陷阱能级进行了计算,讨论了样品的余辉衰战机制。通过对锶钙配比(X值)不同的样品余辉发光性能的比较分析,研究锶钙配比对余辉发光性能的影响。研究表明:通过调节锶钙配比(X值)的方法,能有效调控余辉发光颜色和衰减快慢。  相似文献   

6.
稀土激发的CaMgSi2O6的长余辉发光特性   总被引:5,自引:1,他引:5  
姜岭  常程康  毛大立 《功能材料》2004,35(2):233-235
使用固相反应法在还原气氛中制备了具有长余辉性能的CaMgSi2O6发光材料。研究了不同的共激发离子(Dy^3 和Nd^3 )对于材料发光性能的影响。光谱分析表明了这些磷光体在438nm处有一个宽的发射峰,这个发射峰是由Eu^2 的4f^6 5d^1能级到4f^7能级的跃迁所导致的,而Eu^2 在透辉石中形成六配位的发光中心。获得的3种磷光体都具有长余辉发光性能。其中共掺杂Eu^2 和Dy^3 材料比单掺Eu^2 和共掺Eu^2 扣Nd^3 的材料具有更好的余辉强度扣更长的余辉时间,其原因在于Dy^3 在CaMgSi2O6晶格中形成了更深的和更高密度的陷阱。  相似文献   

7.
选择铝硼硅酸盐玻璃体系,高温熔融法制备了Eu,Dy掺杂的铝硼酸盐基质透明玻璃,并采用槽沉法制备了透明玻璃微球.利用XRD、SEM和荧光光谱对样品进行分析.结果表明:该玻璃微球粒径分布范围窄,光学性能好,其折射率为1.690;单掺杂和双掺杂玻璃微球均具有长余辉发光性能,单掺杂Eu^2+发光峰位于460nm,而双掺杂Eu^2+、Dy^3+的发光峰分别位于456和452nm,并且样品的发光时间达到15h以上。  相似文献   

8.
李炳伟  周新木 《功能材料》2007,38(A01):75-77
用传统的固相合成法合成了共掺杂稀土离子Eu^3+、Sm^3+的红色长余辉材料CaTiO3:Pr,通过对激发、发射光谱、紫外-可见吸收光谱、热释光(TL)的分析,研究了Eu^3+、Sm^3+对其发光性能的影响,得出在样品中存在Eu^3+、Sm^3+向Pr^3+的能量传递现象,它改善了材料的发光性能,最后在文中讨论了可能的能量传递途径。  相似文献   

9.
B2O3对SrAl2O4:Eu2+,Dy3+材料热释光谱和长余辉性能的影响   总被引:2,自引:0,他引:2  
采用高温固相合成法制备了黄绿色SrAl2O4:Eu^2+,Dy^3+长余辉发光材料,其激发光谱峰值为345nm和405nm,发射光谱峰值为520nm.不同B2O3含量样品的扫描电镜照片表明:随着助熔剂硼酸掺入量的增加,晶体的结晶度越来越高;其X射线衍射分析表明:随着硼酸掺入量的增加,属单斜晶系的SrAl2O4晶体结构仍是材料的主相,但是有新的铝酸盐生成.从测得的相应的热释光曲线分析:硼酸掺入量为17mol%的样品具有最大的陷阱能级0.59eV,对应于329K的热释光峰,这一陷阱分布使材料的余辉性能得到了很大的提高.用一般阶动力学模型对热释光曲线进行拟合,得出了它的陷阱参数.  相似文献   

10.
H3BO3对化学共沉淀法制备Sr4Al14O25:Eu^2+、Dy^3+的影响   总被引:8,自引:0,他引:8  
采用化学共沉淀法制备Sr4Al14O25:Eu^2 、Dy^3 长余辉发光粉体。研究了H3BO3的加入对粉体的相组成,晶体结构,发光性能与长余辉特性的影响。结果表明.加入的H3BO3大部分不进入晶格.作为助熔剂有利于Sr4Al14O25相的形成.一小部分H3BO3进入晶格中取代Al^3 离子并且对Sr4Al14O25:Eu^2 、Dy^3 长余辉发光粉体的发光性能与长余辉特性都有显著的提高.然而过量的H3BO3加入则会降低粉体的长余辉特性.本实验所获得H3BO3合适的添加量为0.7mol。  相似文献   

11.
Permeable crystalline materialcan permeate into pores and cracks of concrete and catalyze the reaction between Ca(OH) 2and unhydrated cement to generate a great quantity needle non-soluble crystals, which can stop up the pores and cracks of concrete, and increase the impermeability of concrete. This paper reported the results of a study conducted to evaluate steel reinforcement corrosion of concrete specimens uncoated and coated with permeable crystalline material as well as mixed with the permeable crystalline material. The properties evaluated for corrosion test were water impermeability, water absorption, compressive strength and potential. The results of water impermeability, water absorption, compressive strength clearly showed that the permeable crystalline material could prohibit water, any soluble salts and moisture from penetrating the concrete to cause corrosion, leaking, and other problems, and it did increase the compressive strength, which was favorable for protection of corrosion of reinforcing steel. Moreover, it was concluded from the potential-time curve that the steel reinforcement of uncoated specimen was in the state of activation whereas that of other specimens coated and mixed with the permeable crystalline material was in the state of inactivation. Above all, it was indicated that the permeable crystalline materialis very effective to protect the steel reinforcement of concrete from corrosion.  相似文献   

12.
In this paper, the principle of spurting take off lacquer were introduced; and with orthogonal method the unsaturate polyester was prepared ;it was easy to peel airplane paint layer off with this material and equipment.  相似文献   

13.
Quality Study of Honeycomb Core Shaping Without Wax Stabilization   总被引:1,自引:0,他引:1  
Sandwich panels utilizing honeycomb cores result in lightweight, high-strength units that are very rigid. Indeed, they give honeycomb panels the best strength-to-weight ratio of any construction type available. Conventionally, the wax is poured into the cell of the core to strengthen the structure and prevent the core from being crushed during milling. Much time and labor is required to wax, mill, and clean the cores. In this study, the process of pouring wax into the core was skipped. In other words, the cutter directly milled the core. Experiments showed that the compressive strength of the core produced without wax stabilization was only 3% lower than that of cores produced using the traditional method. In addition, the drum peel strengths of cores produced without wax stabilization were 38.4% higher than cores produced using the traditional method, in which residual wax seriously polluted the adhesive. It was also found that eliminating the wax process can reduce costs.  相似文献   

14.
Polylactic acid (PLA) is one of the most widely used open source fused filament fabrication materials due to its ease of extrusion, biodegradability, and mechanical strength. The mechanical strength of PLA largely depends on the proper growth of its semi-crystalline structure, which can be severely impaired by a low rate of crystallization, particularly in open source printers. This can be further aggravated by the non-uniform thermal distribution of heat that causes improper curing among the extruded beads of the printing material. As a result, PLA printed on open source printers does not achieve the best mechanical properties. This research, for the first time, proposes an additive-free solution implemented through a detailed set of experimentation to improve the curing rate through in-process temperature variations to cure the joints among the beads. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy is used to confirm the improvements in the bead joints. This work is conducted in two phases of experiments. In the first phase, a full factorial ANOVA is used to investigate various process parameters and the important variables are used in the second phase to print test specimens in four different sets.  相似文献   

15.
In continuous hot-dip galvanization process the corrosion and chemical stability of the sink roll in the galvanizing bath are important problem which effects on the quality and productivity. In order to protect the sink roll the carbide cermet and/or ceramic coatings were deposited on the surface of the sink roll. The WC-, Cr3 C2-cermet coatings were deposited by high velocity oxygen fuel (HVOF) spray, respectively. The coating samples were immersed in molten Zn-alloy containing 50 wt % aluminum at 833 K for 24 hr and 144 hr, respectively. The inter-diffusion and inter-reaction of Zn, Al and elements in coating and corrosion behaviors of these coatings were investigated by XRD, SEM and EPMA etc. The corrosion mechanisms of the carbide cermet coatings and ceramic coatings in molten High Al-Zn-alloy were approached.  相似文献   

16.
In many situations, ice often adheres to a cooling solid surface, frequently causing serious accidents. It is critical to clarify the mechanism of ice adhesion to the cooling surface in order to prevent ice adhesion. In a past study, the shearing stresses of two kinds of test plates with a copper surface having the higher thermal conductivity were measured. The shearing stress corresponds to ice adhesion force. Both shearing stresses were significantly different; however, the cause remains unclear.Therefore, the present study focuses on an oxide layer as the main factor causing the difference of both shearing stresses; the influence of the oxide layer formed on shearing stress was discussed. And in the removal and reformation processes of the oxide layer, the time variation of the shearing stress was clarified. Moreover, the relationship between the state of the copper surface and the shearing stress was also clarified by surface analysis.  相似文献   

17.
正When you are enjoying the green,energy-saving and healthy lighting of IKEA LED luminaire,you may not realize that most of IKEA’s LED bulbs are produced by the LED luminaire smart manufacturing system of Hangzhou Zhongwei Photoelectricity CO.,LTD(ZVISION).No longer enclosed in the laboratory,the product standards are brought into the factory workshop and even to the entire production process.Thus,the standards are promoted and applied in a favorable way by enterprises,benefitting consumers with high quality products.  相似文献   

18.
正The international standard,ISO 8124-6,Safety of toys–Part 6:Certain phthalate esters in toys and children’s products,was officially issued by ISO worldwide on August 15.It was the first time for Chinese experts to lead the ISO standard development in toys industry.The standard was drafted by a group of Chinese experts from SAC/TC for toys and relevant Chinese departments and finally completed by a dedicated international group of experts.ISO 8124-6 makes a substantive breakthrough in the aspects of the scope of toys,limitation of plasticizer types,control of test cost,accuracy of test,operation convenience,etc.,offering the operational guidance for toy manufactures and testing laboratories.  相似文献   

19.
正Themed on"quality,innovation,development",the first China Quality Conference(Beijing)was held in the Great Hall of the People on September 15.Chinese Premier Li Keqiang delivered an important speech at the conference.State Councilor Yang Jing and Wang Yong attended the conference with over 600 domestic and international representatives from foreign,regional and international quality organizations  相似文献   

20.
正The National Working Meeting on Land and Resources Standardization was held in Beijing on July 15,2014.Wang Min,the Deputy-Minister of the Ministry of Land and Resources,and Yin Minghan,the Chief-Engineer of SAC addressed the meeting.Representatives from relevant competent departments and technical committees were present.The meeting aims to summarize work,discuss existing problems and make clear working thoughts,promoting standardization work of land and resources to a new level.Wang Min pointed out that the standardization work of land and resources should be centered on the basic principles of"protecting land and resources dutifully,intensively and economically utilizing land and resources,and making all-out efforts to safeguard the public’s rights and interests",highlighted the  相似文献   

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