典型城市固体废弃物热解动力学机理研究

利用热重（TGA）技术研究了城市固体废弃物中塑料橡胶类、木质纤维素类、织物类和厨余类四大类可燃组分中七种典型固体废弃物热解反应过程。实验结果表明,塑料类和织物类最难热解,厨余类组分最易热解;采用Freeman-Carroll法对七种典型固体废弃物热解进行数据处理,从20种常用的固相反应机制函数中遴选出最优解,利用优化的数学函数和动力学参数建立动力学模型,结果表明,PE和羊毛线热解主要反应阶段的最优固相反应模型是球形相界面反应模型;橡胶粉、杨树枝热解反应模型遵循化学反应规律;米饭和本白棉布热解曲线遵循幂函数法则;白菜的最优模型是三维扩散模型。     

铜基氧化物气凝胶的制备与表征

 以CuCl₂·2H₂O为前躯体,环氧丙烷为凝胶促进剂,制得了铜基氧化物气凝胶。通过场发射扫描电镜、高分辨透射电镜、X射线衍射、红外谱图及N₂吸附等方法,对气凝胶的结构进行了表征。结果表明：室温下合成的铜基氧化物气凝胶呈现3维网络状结构,其骨架由大量微小晶粒组成,颗粒粒径为几nm;随处理温度的升高,体系中的有机相逐渐被灼烧完全,气凝胶也由3维网络状结构转变为致密结构;气凝胶随温度升高不断变化,并最终生成氧化铜气凝胶。N₂吸附结果表明气凝胶具有较高的比表面积,为386 m²/g。     

Optical parameters of Nd3＋：Er3＋：yb3＋ co-doped borosilicate glasses and their energy transfers at high temperature

This paper reports that a series of Nd³⁺:Er³⁺:Yb³⁺ co-doped borosilicate glasses have been prepared and their absorption spectra measured. The J--O intensity parameters Ω_k (k=2, 4, 6), spontaneous radiative lifetime τ_rad, spontaneous transition probability A, fluorescence branching ratio β and oscillator strength f_ed of the Nd³⁺ ions at room temperature are calculated based on Judd--Ofelt (J--O) theory. The temperature dependence of the up-conversion photoluminescence characteristics in a Nd³⁺:Er³⁺:Yb³⁺ co-doped sample is studied under a 978 nm semiconductor laser excitation, and the energy transfer mechanisms among Yb³⁺, Er³⁺ and Nd³⁺ ions are analysed. The results show that the J--O intensity parameters Ω₂ increase when the Nd³⁺ concentration of the Nd³⁺:Er³⁺:Yb³⁺ co-doped borosilicate glasses increases. The possibility of spontaneous transition is small and lifetimes are long at levels of ⁴F_5/2 and ⁴F_3/2. The intensity of Nd³⁺ emissions at 595, 691, 753, 813 and 887 nm are markedly enhanced when the sample temperature exceeds 400 K. The reasons being the cooperation of the secondary sensitization from Er³⁺ to Nd³⁺ and the contribution of a multi-phonon.     

羟基自由基引起的脱氧核糖核酸损伤研究

以鲱鱼精脱氧核糖核酸(Herring sperm DNA)为研究对象,利用紫外光(UV,200～275 nm,66.4 Lx)激发纳米TiO2发生光催化作用介导产生羟基自由基(Hydroxyl radical,.OH),探讨.OH引发DNA氧化损伤特性。采用凝胶电泳和高效液相色谱(HPLC)分析法跟踪DNA损伤历程;应用电子自旋共振(Electron spinresonance,ESR)及分光光度法跟踪损伤过程氧化物种及H2O2相对浓度的变化;运用生物标准样8-羟基脱氧鸟苷(8-Hydroxy-2’-deoxyguanosine,8-OHdG)为内标物,通过HPLC分析DNA损伤产物,研究DNA损伤机理。结果表明,较单纯UV辐照或暗光(Dark)催化条件,DNA浓度10 mg/L,TiO2浓度1.5 g/L、pH 7～8,紫外光激发纳米TiO2介导产生.OH引发DNA损伤程度最大;DNA损伤为.OH氧化历程,并伴随有深度氧化过程;DNA结构中鸟嘌呤最易氧化损伤,8-OHdG为DNA氧化损伤中间产物及鸟嘌呤氧化损伤的特异产物。     

磷在P-ZSM-5沸石中存在的形态

用密度泛函理论和ONIOM (our own N-layer integrated molecular orbital molecular mechanics)方法研究磷改性的ZSM-5沸石中含磷基团的可能存在形态. 计算的反应焓和自由能数据表明P-ZSM-5沸石中以磷进入骨架和在骨架外的形成磷酸根离子对是合理的稳定结构. 而且, 计算结果表明离子对模型F和G更适合在室温下存在, 磷进入骨架的酸性结构C'在高温下更稳定, 而磷进入骨架的结构C对温度变化不敏感. 计算得到的²⁷Al, ³¹P, ²⁹Si化学位移、酸性的变化趋势和结构参数与相关实验数据吻合.     

苦皮藤中两个新的 β-二氢沉香呋喃型化合物的 NMR 数据解析

从南蛇藤属植物苦皮藤中分离出两个新的β-二氢沉香呋喃型化合物：1β,2β,15-三乙酰氧基-8α-(α-甲基)-丁酰氧基-9β-苯甲酰氧基-4α,6α-二羟基-β-二氢沉香呋喃（化合物I）和1β,15-二乙酰氧基-8α-(α-甲基)-丙酰氧基-2β,9β-二苯甲酰氧基-4α,6α-二羟基-β-二氢沉香呋喃（化合物II）．通过核磁共振（NMR，包括¹H NMR、¹³C NMR、DEPT、¹H-¹H COSY、NOESY、HSQC、HMBC）技术对化合物所有的¹H和¹³C NMR信号进行了全归属和详细解析.     

Evaluation of polarization field in InGaN/GaN multiple quantum well structures by using electroluminescence spectra shift

In order to investigate the inherent polarization intensity in InGaN/GaN multiple quantum well(MQW) structures,the electroluminescence(EL) spectra of three samples with different GaN barrier thicknesses of 21.3 nm, 11.4 nm, and 6.5 nm are experimentally studied. All of the EL spectra present a similar blue-shift under the low-level current injection,and then turns to a red-shift tendency when the current increases to a specific value, which is defined as the turning point.The value of this turning point differs from one another for the three InGaN/GaN MQW samples. Sample A, which has the GaN barrier thickness of 21.3 nm, shows the highest current injection level at the turning point as well as the largest value of blue-shift. It indicates that sample A has the maximum intensity of the polarization field. The red-shift of the EL spectra results from the vertical electron leakage in InGaN/GaN MQWs and the corresponding self-heating effect under the high-level current injection. As a result, it is an effective approach to evaluate the polarization field in the InGaN/GaN MQW structures by using the injection current level at the turning point and the blue-shift of the EL spectra profiles.     

基于高阶胡氏矩的多目标图象识别算法

本文提出了一种多目标图象识别算法,算法以小波变换和目标区域分割算法实现图象的前期处理,以高阶胡氏矩为基础,利用k邻近法构建了分类器,实现了多类目标的识别与分类.仿真实验证明,此算法具有较高的识别精度.     

离散余弦型线圈结构的二极场应用研究

介绍了粒子加速器中超导二极试验磁体中离散余弦型(DCT)超导线圈的电磁设计、线圈制作和验证测试过程。     

一种新型的地塞米松棕榈酸酯脂质体制剂及其对小鼠的抗炎作用研究

本文报道了一种新型的长循环脂质体地塞米松棕榈酸酯 (DPL long-circulating) 的药物运载系统。将磷脂和胆固醇通过薄膜分散-挤压法得到该DPL long-circulating。考察了该DPL long-circulating配方的稳定性。用老鼠实验来评价DPL long-circulating, DPL和DSP的抗炎活性与急毒性。应用薄膜分散-挤压的方法可以成功得到DPL long-circulating。实验结果表明DPL long-circulating有均匀的粒径和稳定的性质。在抗炎实验中,DPL long-circulating和DPL表现出比DSP更强的抗炎效果。急性毒性实验则表明DSP注射液与DPL long-circulating和DPL相比有较小的毒性,提示DPL long-circulating和DPL可能因为被动靶向作用从而提高了生物利用度。使用上述方法得到的DPL long-circulating满足了质量要求,并且有较高的抗炎活性及急毒性。