The Fabrication and Characterization of Single‐Component Polymeric White‐Light‐Emitting Diodes

By using Ni⁰‐mediated polymerization, we have systematically synthesized a series of fluorene‐based copolymers composed of blue‐, green‐, and red‐light‐emitting comonomers with a view to producing polymers with white‐light emission. 2,7‐Dibromo‐9,9‐dihexylfluorene, {4‐(2‐[2,5‐dibromo‐4‐{2‐(4‐diphenylamino‐phenyl)‐vinyl}‐phenyl]‐vinyl)‐phenyl}‐diphenylamine (DTPA), and 2‐{2‐(2‐[4‐{bis(4‐bromo‐phenyl)amino}‐phenyl]‐vinyl)‐6‐tert‐butyl‐pyran‐4‐ylidene}‐malononitrile (TPDCM) were used as the blue‐, green‐, and red‐light‐emitting comonomers, respectively. It was found that the emission spectra of the resulting copolymers could easily be tuned by varying their DTPA and TPDCM content. Thus with the appropriate red/green/blue (RGB) unit ratio, we were able to obtain white‐light emission from these copolymers. A white‐light‐emitting diode using the polyfluorene copolymer containing 3 % green‐emitting DTPA and 2 % red‐emitting TPDCM (PG3R2) with a structure of indium tin oxide/poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonic acid)/PG3R2/Ca/Al was found to exhibit a maximum brightness of 820 cd m^–2 at 11 V with Commission Internationale de L'Eclairage (CIE) coordinates of (0.33,0.35), which are close to the standard CIE coordinates for white‐light emission (0.33,0.33).     

A new oxyapatite red phosphor Eu3+-doped Ca3Y7(BO4)(SiO4)5O: Synthesis,structure and luminescence properties

A series of new oxyapatite red phosphors Ca₃Y₇(BO₄)(SiO₄)₅O doped with different concentrations of Eu³⁺ were successfully synthesized by high temperature solid state method. The X-ray diffraction (XRD) Rietveld refinement results show that the structure of the phosphor belongs to space group P6₃/m and Eu³⁺ ion replaces Y³⁺ ion. The emission spectrum consists of the characteristic emission peaks corresponding to Eu³⁺ under the excitation of 274 nm and the dominant emission peak is at 614 nm (⁵D₀→⁷F₂ of Eu³⁺). The concentration quenching effect occurs and the optimized Eu³⁺ concentration is 4.0 mol%. The energy level diagram for luminous mechanism is also given and the non-radiative energy transfer mechanism between Eu³⁺ is mainly exchange interaction. The CIE coordinate is close to the ideal red light and the color purity is higher than 99.79%. Moreover, the phosphor exhibits moderate thermal stability because the photoluminescence intensity at 423 K is still maintained at higher than 78.97% of that at room temperature. The internal quantum efficiency of Ca₃Y₇(BO₄)(SiO₄)₅O:4.0 mol%Eu³⁺ phosphor is 58.2%. A red light emitting diode (LED) device based on it can emit bright red light. The CCT values of the device are basically unchanged when driven by various bias current. The results show that Ca₃Y₇(BO₄)(SiO₄)₅O:Eu³⁺ is a new type of oxyapatite red fluorescent material with good comprehensive performances.     

离心铸造汽缸套白斑产生机理

针对离心铸造汽缸套的白斑特征，以模拟试验手段探寻原因。用金属凝固理论解释白斑形成机理。经过装车试用，验证了白斑对摩擦性能的影响。     

Surface integrity in finish hard turning of case-hardened steels

Highly stressed steel components, e.g., gears and bearing parts, are appropriate applications for hard turning. Therefore, the process effects on significant engineering properties of work materials have to be carefully analyzed. Roughness, residual stresses, and white layers as parts of surface integrity, are functions of the machining parameters and of the cuttability of the cutting edge, i.e. of the tool wear.The aim of this work was to study the influence of feed rate, cutting speed, and tool wear on the effects induced by hard turning on case-hardened 27MnCr5 gear conebrakes and to point out the technical limitations in mass production.     

白油加氢装置技术改造

对抚顺石油化工分公司石化三厂白油加氢装置进行技术改造，通过调整加氢工艺，采用一段加氢工艺生产高品级的加氢尾油，再经分馏系统生产出多种优级品的白油，满足了市场需求，并创造了可观的经济效益和社会效益。     

不同添加剂对SrAl2O4:(Eu,Dy)磷光体发光性能的影响

在较低的温度下用燃烧合成法快速合成了 Eu2 ,Dy3 掺杂的SrAl2O4长余辉磷光体发光材料.研究了P2O5,CaF2,H3BO3,NaF 几种添加剂对SrAl2O4:(Eu,Dy)粉体发光性能的影响.结果发现:H3BO3和P2O5的添加有利于改善磷光体的发光性能,而在配料中加入CaF2和NaF,磷光体发光效率降低.随着这几种添加剂的加入,SrAl2O4:(Eu,Dy)磷光体材料发射光谱的主发射峰不同程度的出现蓝移.根据实验结果分析了添加剂的作用机理.     

无磷条件下膜生物反应器处理化工废水

在进水不含磷条件下,对膜生物反应器(MBR)系统的运行情况进行了研究。结果表明:微生物充分利用体内储存的聚磷酸盐及死亡细胞和碎片中的磷进行生长,因此混合液悬浮固体(MLSS)仍能增加,最后稳定在8.5 g/L;化学需氧量(COD)处理效果一直较好;氨氮和总氮去除率可达90％及70％;系统经历了丝状菌膨胀和非丝状菌膨胀两个阶段。在缺磷的情况下,MBR系统的处理结果并未受到很大影响。     

Synthesis and luminescence properties of red phosphor CaO: Eu3+

Ca(NO₃)₂·4H₂O, Eu(NO₃)₃ and H₂C₂O₄·2H₂O were adopted to synthesize CaO: Eu³⁺ with the chemical co-precipitation method, and the effects of the calcination temperature and Eu³⁺ doping concentration on the phosphor structure and its luminescent properties were investigated by TG-SDTA, XRD, and PL-PLE. The results confirm that the Eu³⁺ ions as luminescent centers substitutes Ca²⁺ sites without changing the crystal structure of cubic CaO. The optimum calcination temperature and the optimum concentration of Eu³⁺ are 1 100 ° and 1 mol%, respectively, under which the best crystallinity and highest PL intensity appeared. The maximum emission wavelength is 592 nm (⁵D₀→⁷F₁) which is excited by xenon lamp with the wavelength of 200–280 nm, indicating that the Eu³⁺ ion mainly locates in the symmetric position (O_h) in the crystal lattice of CaO. Funded by the Science and Technology Bureau of Sichun Province(No. 2006J13-059) and Education Bureau of Sichun Province (No. 2006A094)     

电化学沉积法制备稀土掺杂氧化钇荧光薄膜的发光性能

通过改变氧化钇薄膜中掺杂稀土元素的种类,来控制发光薄膜的荧光发射波长.利用电化学沉积法制备稀土掺杂氧化钇荧光薄膜.电化学沉积法制备的薄膜结晶效果好,掺杂离子分布较均匀,且不需要高温高压或者真空条件,成本很低.所制备的Y2O3:Ln荧光发光薄膜经XRD分析具有立方晶体结构;不同稀土掺杂的氧化钇呈现出不同的表面形貌;掺杂的Ln离子均匀地分布在薄膜中,经测试所有的Y2O3:Ln荧光发光薄膜都显示出较强的发射强度,且发光波长随着掺杂离子的不同而不同:Y2O3:Er3+发绿光,Y2O3:Ce3+发黄绿光,Y2 O3:Sm3+发蓝光,Y2O3:Pr3+发橙光.因此,电化学沉积法可用于制备具有不同发光波长的氧化钇荧光薄膜.     

梳棉机针布选配与工艺优化

探讨了梳棉机针布选配和工艺参数的选择问题。通过工艺对比得出,纺C14.6 tex棉纱时针布选配应按照锡林针布稀、盖板针布密的原则进行。在生条定量3.9 g/m、刺辊速度970 r/min、锡林速度403 r/min工艺条件下,有利于进一步提高成纱质量。