Energy transfer and excitation wavelength dependent long-lasting phosphorescence in Pr activated Y3Al5O12

Long-lasting phosphorescence (LLP) was observed in Pr³⁺-doped Y₃Al₅O₁₂ (YAG:Pr) after it was excited by 240 or 290 nm light. The photoluminescence (PL) and LLP properties were studied. It is interesting that the PL and LLP spectra were different. In the PL emission spectra both the emissions of d-f and f-f transitions of Pr³⁺ ions were observed. However, in the LLP spectra of YAG:Pr the emissions of d-f transition were absent. It is deduced that the differences were due to the energy transfer process between traps and emission centers. On the other hand, significant differences were observed between the two LLP spectra after the sample was excited by 240 and 290 nm lights, respectively. The thermoluminescence (TL) properties were also studied. It is suggested that these studies will be significant for understanding the mechanism of LLP phenomenon.     

Tailoring the wettability of patterned silicon surfaces with dual-scale pillars: From hydrophilicity to superhydrophobicity

Wettability tailoring of patterned silicon surface has great potential in fields producing integrated circuits, solar cells, sensors, detectors, and micro/nano electromechanical systems. The present paper presents a convenient yet effective method of combining reactive ion etching and catalyzed etching to prepare silicon surface with micro-nano dual-scale pillars. The experimental results indicate that the hydrophilic surface transformed to a superhydrophobic surface when micro-nano dual-scale pillars were formed. The surface preserved superhydrophobicity even when the geometric parameters of the micropillars were changed. Overhangs of water drops on steep micro-nano dual-scale pillars result in superhydrophobicity. This method offers a new way for tailoring the wettability of patterned silicon surfaces.     

云南植物——露水草中的一种新植物甾酮的分离与分析

云南植物露水草富含植物甾酮类成分。为了研究其中的生物活性成分,采用多种色谱分离方法(氧化铝柱色谱、硅胶柱色谱、常压反相C18柱色谱、制备薄层色谱及反相高效液相色谱等)相结合,从露水草中分离得到一种新植物甾酮。综合一维和二维核磁共振光谱以及电喷雾质谱数据分析,确定该化合物的结构为3β,4α,14α,20R,22R,25-hexahydroxy-5α-cholest-7-en-6-one,为一种较为少见的具有5α-H的植物甾酮。     

二氧化锰纳米材料水热合成及形成机理研究进展

不同晶型和形貌MnO2纳米材料由于具有离子筛、分子筛、催化和电化学等许多特殊的物理和化学性质,因而在吸附材料、催化材料、锂离子二次电池的正极材料和新型磁性材料等领域显示了广阔的应用前景。纵观合成MnO2纳米材料的各种方法,水热合成由于简单、易于控制,并且能够有效控制其晶型、形貌和尺寸,深受研究者的青睐。本文结合国内外的...     

Long lasting phosphorescence of Eu2+-activated MO-B2O3 glasses

In this letter, Eu 2+ -activated MO-B 2 O 3 (M=Ca, Sr, and Ba) glasses are prepared in reductive atmosphere and their long lasting phosphorescence properties are studied. The intensity of the phosphorescence for the glasses is Sr>Ca>Ba. The light-induced electron paramagnetic resonance signal is observed after the irradiation of an ultraviolet lamp, which is due to the electron trapped by oxygen vacancy. The energy depth of the glasses is calculated using Hoogenstraaten’s method.     

Entangled Fourier Transformation and its Application in Weyl-Wigner Operator Ordering and Fractional Squeezing

In order to entangle the functions to be transformed, we proposed the entangled. Fourier integration transformation (EFIT) which has the property of keeping modulus-invariant for its inverse transformation. Then we then studied Wigner operator’s EFIT and found that a function’s EFIT is just related to its Weyl-corresponding operator’s matrix element, in so doing we also derived new operator re-ordering formulas \( \delta \left(x-P\right)\left(y-Q\right)=\frac{1}{\pi }{\displaystyle \begin{array}{c}:\\ {}:\end{array}}{e}^{-2i\left(P-x\right)\left(Q-y\right)}\ {\displaystyle \begin{array}{c}:\\ {}:\end{array}} \);\( \delta \left(y-Q\right)\left(x-P\right)=\frac{1}{\pi }{\displaystyle \begin{array}{c}:\\ {}:\end{array}}{e}^{2i\left(P-x\right)\left(Q-y\right)}\ {\displaystyle \begin{array}{c}:\\ {}:\end{array}} \), where P, Q are momentum and coordinate operator respectively, the symbol \( {\displaystyle \begin{array}{c}:\\ {}:\end{array}}\ {\displaystyle \begin{array}{c}:\\ {}:\end{array}} \) denotes Weyl ordering. By virtue of EFIT we also found the operator which can generate fractional squeezing transformation.

     

Elimination effects of toxic trans-crotonaldehyde in mitochondria of glioma by lithocholic acid

The purposes of this study were to explore the factors contributing to the generation of the toxic trans-crotonaldehyde in mitochondria of glioma and to look for the elimination effects of the toxic trans-crotonaldehyde by the lithocholic acid. Ultraviolet-visible absorption spectroscopy and mitochondrial isolation and extraction from glioma were used in this study. Research findings showed that the factors contributing to the generation of the toxic trans-crotonaldehyde were hydrogen peroxide, mitochondria of glioma, and their appropriate interaction, respectively. The appropriate quantity of the toxic trans-crotonaldehyde could be induced by hydrogen peroxide (0.16?mmol), mitochondria of glioma (3?mg protein/ml), and 30?min of their interaction, respectively. The most suitable conditions for the lithocholic acid to eliminate the toxic trans-crotonaldehyde were the weakly alkaline of mitochondria of glioma (pH 8.0), the lithocholic acid (0.15?mmol), and 15?min of interaction, respectively. The conclusion was that the lithocholic acid efficiently eliminated the toxic trans-crotonaldehyde in mitochondria of glioma in real time and opened up a new way to treat glioma.     

微波辅助萃取-超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法快速测定食品接触塑料制品中48种污染物残留

利用超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法（UPLC-Q Orbitrap HRMS）的同时定性定量功能,建立了食品接触塑料制品中48种污染物残留的检测方法。用甲醇提取目标化合物,经微波辅助萃取,采用CAPCELL PAK MG Ⅱ C18色谱柱（150 mm×2.0 mm,5 μm）分离,以0.04%（v/v）甲酸甲醇溶液和含0.04%（v/v）甲酸与20 mmol/L（v/v）乙酸铵的水溶液为流动相进行梯度洗脱,在加热电喷雾电离（HESI）源、全扫描/实时二级质谱（Full MS/dd-MS²）监测模式下进行检测。结果表明,48种目标化合物在各自范围内线性关系良好,相关系数（r）均≥ 0.9950;检出限为0.1~1.0 μg/kg;平均加标回收率为71.2%~108.8%,相对标准偏差为2.2%~11.8%（n=6）。该法具有操作简单快捷、灵敏度高等优点。     

Long lasting phosphorescence of Eu in reduced SrO-B2O3 glasses

The blue long-lasting phosphorescence (LLP) phenomenon was observed for Eu²⁺-doped SrO-B₂O₃ glasses prepared in the reducing atmosphere. The phosphorescence peaks at about 450 nm due to the 4f5d→4f transition of Eu²⁺. With the doping of different amounts of Eu²⁺, the concentration-quenching phenomenon was observed for both the LLP and photoluminescence of the glasses, and the critical concentration for the two cases was same, i.e., 0.02 mol% Eu²⁺. And by the investigation of the TL curves, the content of Eu²⁺ had an effect on the trap depth of the samples. At last the possible mechanism of the LLP of the samples was suggested.     

里耶地下秦代古城护城河空间位置低损探查

文物遗址勘察在工程地质勘察领域具有特殊性。根据前期对遗址的部分发掘,考古专家推断里耶秦代古城墙遗址周围是被埋入地下的古护城河,且河底可能埋藏有珍贵文物。古护城河空间位置的精确测定对该遗址保护、继续发掘和开发利用具有重要意义。古护城河被地表沉积物掩埋、部分古河段与近代池塘重叠、常规勘探可能破坏珍贵文物、电磁干扰较严重等给古护城河空间精确定位带来了很大困难。本文针对这些难题采用切合实际的高密度电法和改进的轻便取芯触探相结合的综合探查方法实现了精确定位,实践证明该方法在文物遗址勘察方面具有许多传统勘探方法无法比拟的优点。