基于仪器全寿命周期理念的化学实验教学与管理

实验仪器是高等化学教育中的重要资源,也是高校实验管理的重要核心.在日常仪器教学管理过程中,如何结合化学仪器的特点,并基于化学仪器的全寿命周期,从仪器管理人员配置、仪器资源平台搭建等方面进行实验教学与管理,则尤为重要.本文就目前高校化学实验教学与管理中的现状,提出了基于化学仪器全寿命周期理念的教学管理模式,希望为进一步的...     

Li2Y4–xEux（MoO4）7荧光粉的制备及发光性能

采用高温固相法合成了系列红色荧光粉Li2Y4–xEux(MoO4)7。合成样品的最佳烧结温度和时间分别为850℃和4h。X射线衍射显示样品为纯相Li2Y4(MoO4)7四方晶系晶体结构。光致发光光谱表明,该样品能够被395nm的近紫外光和465nm的可见光有效激发,主发射峰位于615nm附近,对应于Eu3+的5D0→7F2跃迁,显色性能好,可作为白光发光二极管用红色荧光粉;且Eu3+的掺杂量x为2.8时,样品Li2Y1.2Eu2.8(MoO4)7的相对发光强度达到最大值。     

新型磁力操动机构EMFA的动态特性仿真研究

针对40.5 kV新型磁力机构工作原理及其运动特点,进行了多场耦合的静态和动态特性仿真研究.首先,建立磁力操动机构的有限元模型,利用Maxwell软件对磁力机构的静态特性进行仿真;其次,根据电压平衡方程和达朗贝尔运动方程,在静态仿真基础上采用ADAMS和MATLAB建立40.5 kV磁力机构SF6断路器运动模型,对磁力...     

Synthesis and photoluminescence properties of Ca3R2-xWO9:xEu3+(R=Y,Gd) phosphors

Ca3R2–xWO9:xEu3+(R=Y, Gd) red-emitting phosphors were prepared by solid state reactions. These samples were characterized by differential scanning calorimetry and thermogravimetry analysis(DSC-TGA), X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR), photoluminescence(PL) and field emission scanning electron microscopy(FE-SEM) analyses. The optimum sintering temperature for these phosphors was 1100 oC, and the optimum sintering time was 2 h. The optimum doped concentration of Eu3+3+ in Ca3Y2–xWO9:xEu and Ca3Gd2–xWO9:xEu3+ were x=1.5 and x=1.1, respectively. These phosphors could be excited by near-UV light of 394 nm and blue light of 465 nm, and showed strong red emission line at 612 nm(5D0→7F2), which indicated that Ca3R2–xWO9:xEu3+(R=Y, Gd) were promising red candidates for white LED.     

基于绿色化学习惯养成的绿色化学实验教学研究

目前绿色化学教育研究在国内外有诸多开展,教学议题围绕着实验教学中"实验开展"和"行为培养"有诸多展开。本文围绕着绿色化学的内涵,阐述了绿色化学在高等教育阶段的重要性,并结合教学实践提出了高等教育阶段开展绿色化学实验的措施,以期学生通过系统的绿色化学行为培养,形成良好的绿色化学习惯。     

葡萄籽中原花青素的精制与纯化

采以葡萄籽为原料,用乙醇提取葡萄籽中的原花青素,用大孔树脂进行纯化,探讨不同树脂的吸附和解吸性能,同时研究了上样速率、上样体积,洗脱剂种类及洗脱剂浓度等因素的影响,并对粗产品和纯化物进行红外表征。结果表明,H2MGL大孔树脂对葡萄籽原花青素的吸附效果最好,在树脂体积为27 m L,上样量为120 m L,上样速率为1.2 m L/min,洗脱剂为45%的乙醇时纯化效果最好,解吸率达到94.65%,此条件下得到的固体纯度为91.48%,说明用H2MGL大孔树脂纯化的方法可行。     

Synthesis and luminescence characteristics of Li2Y4-xEux（WO4）7-y（MoO4）y red-emitting phosphor for white LED

Li2Y4-xEux（WO4）7-y（MoO4）y red-emitting phosphors were synthesized by solid state reaction and characterized by powder X-ray diffraction （XRD） and photoluminescence （PL） spectrum. The excitation spectra showed that the phosphors could be efficiently excited by near-UV light of 395 nm. When the relative molar ratio of Mo/W was 7：0, and the optimum doped concentration of Eu3＋was 2.8 mol, the phosphor showed strong red emission lines at 615 nm corresponding to the forced electric dipole 5D0→7F2 transition of Eu3＋. Compared with Na2Y2Eu2（MoO4）7 and K2Y2Eu2（MoO4）7, the fluorescence intensity of Li2Y1.2Eu2.8（MoO4）7 phosphor was the strongest. The CIE chromaticity coordinates of Li2Y1.2Eu2.8（MoO4）7 phosphor was calculated to be （0.66, 0.34）.