在不同激光脉宽下的高次谐波

用数值计算方法计算了不同强激光脉冲宽度下高次谐波的产生.我们发现对于激光场强度不高,不能有效电离初态的激光场,长脉冲宽度可以更有效产生高次谐波;而对于高场强的激光场,由于它能够在几个光学周期之内把原子的初态全部电离,所以短脉冲的激光场能够更有效产生高次谐波.     

Synthesis of mikto‐topology star polymer containing one cyclic arm

Well‐defined mikto‐topology star polystyrene composed of one cyclic arm and four linear arms was synthesized by a combination of atom transfer radical polymerization (ATRP) and Cu‐catalyzed azide‐alkyne cycloaddition (CuAAC) click reaction. First, the bromine‐alkyne α,ω‐linear polystyrenes containing four hydroxyl groups protected with acetone‐based ketal groups were synthesized by ATRP of styrene using a designed initiator. Then, the bromine end‐group was converted to the azide and the linear polystyrene was cyclized intra‐molecularly by the CuAAC reaction. The four hydroxyl groups were released by deprotection and then esterified with 2‐bromoisobutyryl bromide to produce a cyclic polymer bearing four ATRP initiating units. By subsequent ATRP of styrene to grow linear polymers with the cyclic polystyrene as a macroinitiator, the mikto‐topology star polymers were prepared. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

CuAPTPP-TDI-TiO2光催化微球的合成及其光催化性能 (cited: 1)

采用Adler法合成了5-(4-氨基苯基)-10,15,20-三苯基卟啉铜配合物(CuAPTPP),通过甲苯二异氰酸酯(TDI)的桥联作用对TiO₂微球进行表面修饰,使TDI分子中的两个活性TDI基团分别与TiO₂表面的羟基和CuAPTPP的氨基反应,将CuAPTPP敏化剂分子以化学键合的方式固定在TiO₂表面,形成光催化微球CuAPTPP-TDI-TiO₂．通过FT-IR、XRD、SEM、EA、UV-Vis和DRS等测试手段对CuAPTPP-TDI-TiO₂进行结构表征．讨论了桥联分子TDI修饰量对光催化微球性能的影响,确定了TDI与TiO₂的最佳摩尔比．以亚甲基蓝(MB)为降解对象,考察了CuAPTPP-TDI-TiO₂微球的可见光催化性能．结果表明,桥联分子TDI在CuAPTPP与TiO₂微球表面形成了牢固的化学键,复合微球在150 W氙灯辐照下降解10 mg/LMB溶液,120 min降解率可达98.7%,其降解率过程服从一级动力学规律,测得降解速率常数为5.1×10^-2 min^-1,半衰期为11.3 min．催化微球在回收4次的条件下,对MB的降解率仍保持在90%以上．     

Al高掺杂浓度对ZnO禁带和吸收光谱影响的第一性原理研究

采用密度泛函理论框架下的第一性原理平面波超软赝势方法, 建立了未掺杂与不同浓度的Al原子取代Zn原子的两种Zn_1-xAl_xO超胞模型,分别对模型进行了几何结构优化、态密度分布和能带分布的计算. 结果表明: ZnO高掺杂Al的条件下, 掺杂的Al原子浓度越大,间隙带越窄, 蓝移越弱. 计算结果和实验结果相一致.     

The local ultraconvergence of high‐order finite element method for second‐order elliptic problems with constant coefficients over a rectangular partition

In this article, we will discuss the local ultraconvergence of high‐degree finite element method based on a rectangular partition for the second‐degree elliptic problem with constant coefficients in Ω ? ?² , u( y ) = 0 on ?Ω . Based on suitable regularity, ultraconvergence of the displacement of the extrapolated kth (k ≥ 3) degree finite element solution has been obtained by an extrapolation technique. Finally, numerical experiments are applied to demonstrate our theoretical findings.     

Lipid profiling of human plasma from peritoneal dialysis patients using an improved 2D (NP/RP) LC-QToF MS method

An improved online two-dimensional liquid chromatography-quadrupole time-of-flight mass spectrometry (2D LC-QToF MS) system was developed for the lipid profiling of human plasma, in which different lipid classes were separated by the first dimensional normal-phase (NP) LC and different lipid molecular species were separated by the second dimensional reversed-phase (RP) LC. This 2D LC-QToF MS system was built based on a ten-port, two-position valve as the interface, the conditions of which had been optimized and discussed in detail. As two loops were used to trap and transfer the first dimensional elute to the second dimension separately, this new interface suppressed the sample band broadening in the first dimensional column, increased the recovery and repeatability of 2D LC interface, and offered the possibility for the realization of not-stop-flow NP/RP 2D LC system. Finally, 190 endogenous lipid species out of 10 lipid classes were determined within a single run from the plasma of peritoneal patients. This method was also applied to identify the difference in lipid profile between plasma from peritoneal dialysis patients with bad volume status and peritoneal dialysis patients with good volume status. The discovery of 30 potential biomarkers would be helpful to the malnutrition, inflammation, and atherosclerosis syndrome investigation.     

Development and validation of a rapid and sensitive assay for the determination of anisodamine in 50 μL of beagle dog plasma by LC–MS/MS

A simple, rapid, high‐throughput, and highly sensitive LC–MS/MS was developed to determine anisodamine in a small volume (50 μL) of beagle dog plasma using atropine sulfate as the internal standard. The analyte and internal standard were isolated from 50 μL plasma samples after a one‐step protein precipitation using Sirocco 96‐well protein precipitation filtration plates. The separation was accomplished on a Hanbon Hedera CN column (100 × 4.6 mm, 5 μm) and the run time was 4 min. A Micromass Quatro Ultima mass spectrometer equipped with an ESI source was operated in the multiple reaction monitoring mode with the precursor‐to‐product ion transitions m/z 306.0→140.0 (anisodamine) and 290.0→123.9 (atropine) used for quantitation. The method was sensitive with a low LOQ of 0.05 ng/mL, and good linearity in the range 0.05–50 ng/mL for anisodamine (r² ≥ 0.995). All the validation data, such as accuracy, intra‐ and interrun precision, were within the required limits. The method was successfully applied to the pharmacokinetic study of anisodamine hydrochloride injection in beagle dogs.     

基于SEDRIS的虚拟试验合成环境建模技术研究

为解决合成环境的统一描述和可交互问题,在分析合成环境数据表示与转换标准SEDRIS基础上,提出了基于SEDRIS的虚拟试验合成环境建模方法,针对大气、红外、电磁等3类自然环境,给出了实现环境数据表示和转换的技术途径。通过系统开发,实现了4种试验环境条件下对产品性能的验证与评估,建立的环境模型具有良好的交互性,建模方法可应用于多种试验环境的描述,为虚拟试验合成环境模型体系、标准规范和辅助工具的形成打下了基础。