PEG、白炭黑复合相变储能材料的制备与性能研究

为拓宽相变储能材料的应用范围,以聚乙二醇400(PEG-400)为相变囊心材料,气相法二氧化硅(俗称白炭黑)为载体,采用囊壁溶液包裹制备了一种微胶囊定型相变材料.通过DSC、TGA、SEM试验对复合定形相变材料的性能和结构进行测试.结果表明:聚乙二醇与白炭黑的质量比为5:3、囊壁材料质量分数为8.5％、定型相变材料与囊壁溶液质量比在1:0.45和1:0.55之间时,制备的相变材料性能最优;制备的两种微胶囊定型相变材料的相变温度为-1.34、-2.19℃,相变焓为54.7、52.83 J·g-1;复合定型相变材料在366.38、384.13℃以内质量损失较小,热稳定性良好;微胶囊定型相变材料定形效果和热稳定性良好.     

Luminescent characteristics of LiCaBO3：Eu^3＋ phosphor for white light emitting diode

LiCaBO3:Eu3+ phosphor was synthesized by high solid-state reaction method, and its luminescent characteristics were investigated. The emission and excitation spectra of LiCaBO3:Eu3+ phosphors exhibited that the phosphors could be effectively excited by near ultraviolet (400 nm) and blue (470 nm) light, and emitted red light. The effect of Eu3+ concentration on the emission spectrum of LiCaBO3:Eu3+ phos-phor was studied. The results showed that the emission intensity increased with increasing Eu3～ concentration, and then decreased because of concentration quenching. It reached the maximum at 3mol.% Eu3+, and the concentration self-quenching mechanism was the d-d interaction according to the Dexter theory. Under the conditions of charge compensator Li+, Na+ or K+ incorporated in LiCaBO3, the emission intensities of LiCaBO3:Eu3+ phosphor were enhanced.     

Dy3+激活的LiCaBO3材料发光特性研究

采用固相法制备了LiCaBO₃∶Dy³⁺发光材料. 材料的发射光谱为一多峰宽谱, 主峰分别为484、577和668nm; 监测577nm发射峰, 对应的激发光谱为一主峰位于331、368、397、433、462和478nm的宽谱. 研究了Dy³⁺浓度对材料发射光谱及发光强度的影响, 结果随Dy³⁺浓度的增大, 材料的黄、蓝发射峰强度比(Y/B)逐渐增大; 同时, 发光强度呈现先增大后减小的趋势, 最大值对应的Dy³⁺浓度为3.00mol%, 其浓度猝灭机理为电偶极电偶极相互作用. 引入Li⁺、Na⁺或K⁺可增强材料的发射强度. InGaN管芯激发下的LiCaBO₃∶Dy³⁺材料呈现很好的白光发射, 色坐标为x=0.3001, y=0.3152.     

Dy3+激活的LiCaBO3材料发光特性研究

采用固相法制备了LiCaBO₃∶Dy³⁺发光材料. 材料的发射光谱为一多峰宽谱, 主峰分别为484、577和668nm; 监测577nm发射峰, 对应的激发光谱为一主峰位于331、368、397、433、462和478nm的宽谱. 研究了Dy³⁺浓度对材料发射光谱及发光强度的影响, 结果随Dy³⁺浓度的增大, 材料的黄、蓝发射峰强度比(Y/B)逐渐增大; 同时, 发光强度呈现先增大后减小的趋势, 最大值对应的Dy³⁺浓度为3.00mol%, 其浓度猝灭机理为电偶极电偶极相互作用. 引入Li⁺、Na⁺或K⁺可增强材料的发射强度. InGaN管芯激发下的LiCaBO₃∶Dy³⁺材料呈现很好的白光发射, 色坐标为x=0.3001, y=0.3152.     

Synthesis and Properties of Eu Activated Strontium Molybdate Phosphor

In order to prepare fluorescent material for white Light Emitting Diodes （LEDs）, a new Eu^3＋ activated molybdate phosphor SrMoO4 was fabricated with solid-state method. X-ray diffraction （XRD） showed that the doping of trivalent europium ion reduced the lattice parameters. The excitation and emission spectra indicated that this phosphor could be excited effectively by the visible light, and then emitted red light with the peaks located at 616 and 624 nm. The influence of Eu^3＋ concentration on the luminescent properties of Eu^3＋ doped SrMoO4 was investigated and the 25% （mole fraction） was the appropriate molar concentration. The reaction time and temperature had obvious effect on the luminescent properties. The luminescent intensity reached the strongest when it was sintered at 800 ℃ for 3 h.     

"无事故管理"在采矿安全生产中的实践与应用

"无事故管理"是以安全事故为"零"的安全管理的新模式与新理念,是安全管理的一项创新.梅山矿业公司采矿场在安全管理上推行"无事故管理",促进了安全管理水平的整体提升.     

LiCaPO4:Eu3+材料制备白光LED及其发光特性

采用高温固相法制备了LiCaPO4:Eu3+红色发光材料,研究了Eu3+掺杂浓度、R+或Cl-等对材料发光性质的影响.结果显示,在399 nm近紫外光激发下,材料呈多峰发射,分别由Eu3+的5DO→7FJ(J=0,1,2,3,4)能级跃迁产生,主峰为612 nm;监测612 nm发射峰,所得激发光谱由O2-→Eu3+电...     

KBaPO4:Tb3+材料制备及其发光特性

采用高温固相法合成了KBaPO4:Tb3+绿色发光荧光粉,并研究了材料的发光性质.KBaPO4:Tb3+材料呈多峰发射,发射峰位于437、490、545、586和622 nm,分别对应Tb3+的5D3→7F4和5D4→7FJ=6,5,4,3跃迁发射,主峰为545 nm;监测545 nm发射峰,所得激发光谱由4f 7-5d1的宽带吸收(200～330 nm)和4f-4f电子吸收(330～400 nm)组成,主峰为380 nm.研究了Tb3+掺杂浓度,电荷补偿剂Li+、Na+、K+和Cl-,及敏化剂Ce3+对KBaPO4:Tb3+材料发射强度的影响.结果显示,调节激活剂浓度、添加电荷补偿剂或敏化剂均可在很大程度上提高材料的发射强度.上述结果表明KBaPO4:Tb3+材料是一种很好的近紫外光激发型高效绿色发光荧光粉.     

老化前后沥青与沥青混合料指标相关性分析

为分析老化前后沥青与沥青混合料指标相关性，开展了相应室内试验研究：在不同老化阶段进行沥青针入度、延度、软化点试验；在中、低温条件下，对不同老化时期AC-13沥青混合料进行半圆弯拉试验，分析混合料力学强度、弹性模量、断裂能演化规律；将老化前后沥青三大指标与沥青混合料力学指标进行相关性回归分析。试验结果表明，老化初期对混合料强度、弹性模量影响较大，且老化对弹性模量影响较为敏感；混合料对低温断裂能作用明显，中温断裂能显著高于低温断裂能；混合料老化前后的强度、弹性模量与沥青三大指标具有较高线性相关性，针入度可对中低温下混合料力学性能进行预测。