可见光驱使铜盐催化芳香烃二氟烷基化反应

以CuI为铜源, 通过原位形成光催化剂的途径, 实现了室温下可见光驱使铜催化溴二氟乙酸乙酯、溴二氟酰胺等对芳烃及杂芳烃的二氟烷基化反应. 该反应条件温和、原料廉价易得、底物适用范围广、产率较高, 为合成二氟烷基(杂)芳烃化合物提供了一种方法. 机理研究表明, 该反应可能经历了单电子转移的自由基反应历程.     

Effect of compressed CO2 on the properties of lecithin reverse micelles

Lecithin is a very useful biosurfactant. In this work, the effects of compressed CO 2 on the critical micelle concentration (cmc) of lecithin in cyclohexane and solubilization of water, lysozyme, and PdCl 2 in the lecithin reverse micelles were studied. The micropolarity and pH value of the polar cores of the reverse micelles with and without CO 2 were also investigated. It was found that CO 2 could reduce the cmc of the micellar solution and enhance the capacity of the reverse micelles to solubilize water, the biomolecule, and the inorganic salt significantly. Moreover, the water pools could not be formed in the reverse micelles in the absence of CO 2 because of the limited amount of water solubilized. However, the water pools could be formed in the presence of CO 2 because large amounts of water could be solubilized. All of these provide more opportunity for effective utilization of this green surfactant. The possible mechanism for tuning the properties of the reverse micelles by CO 2 is discussed.     

Water‐in‐Supercritical CO2 Microemulsion Stabilized by a Metal Complex

Herein we propose for the first time the utilization of a metal complex for forming water‐in‐supercritical CO₂ (scCO₂) microemulsions. The water solubility in the metal‐complex‐stabilized microemulsion is significantly improved compared with the conventional water‐in‐scCO₂ microemulsions stabilized by hydrocarbons. Such a microemulsion provides a promising route for the in situ CO₂ reduction catalyzed by a metal complex at the water/scCO₂ interface.     

Quantitative determination of isorhamnetin, quercetin and kaempferol in rat plasma by liquid chromatography with electrospray ionization tandem mass spectrometry and its application to the pharmacokinetic study of isorhamnetin

A simple and sensitive liquid chromatography/tandem mass spectrometry method was developed and validated for the quantification of quercetin, kaempferol and isorhamnetin in rat plasma. After being treated with beta-glucuronidase and sulfatase, the analytes were extracted by liquid/liquid extraction with the internal standard (IS; baicalein). The chromatographic separation was performed on a Diamonsil C(18) column with a mobile phase consisting of 2% formic acid/methanol (10:90, v/v) at a flow rate of 1.00 mL/min, with a split of 200 microL to the mass spectrometer. Validation results indicated that the lower limit of quantification (LLOQ) was 1 ng . mL(-1). The assay exhibited a linear range of 1-200 ng . mL(-1) and gave a correlation coefficient of 0.9980 or better for each analyte. Quality control samples (1, 5, 20 and 100 ng . mL(-1)) in six replicates from each of three different runs demonstrated an intra-assay precision (RSD) of 1.1-8.9%, an inter-assay precision of 1.6-10.8%, and an overall accuracy (bias) of <13.4%. The extraction recovery of each analyte and internal standard was 70-80%. In the present study, we have investigated the pharmacokinetic profiles of isorhamnetin after oral application in rats equipped with a jugular catheter. After oral dosing of isorhamnetin, the mean values (n = 10) of C(max) were 57.8, 64.8 and 75.2 ng . mL(-1) which were achieved at a T(max) of 8.0, 6.4 and 7.2 h for oral doses of 0.25, 0.5 and 1.0 mg . kg(-1) body weight, respectively. The corresponding mean values for isorhamnetin area under the curver (AUC) from 0 to 60 h were 838.2, 1262.8, 1623.4 ng . h . mL(-1). Our results further demonstrated that the samples analyzed showed isorhamnetin could not be transformed into quercetin or kaempferol in rats, indicating that the demethylation of the 3'-oxymethyl group of isorhamnetin does not occur in Wistar rats.     

生物样品中速可眠及代谢产物的分析

应用气相色谱／质谱（ＧＣ／ＭＳ）法对一例速可眠中毒病人生物样品进行分析鉴定。样品经酸化、乙醚提取,然后于ＧＣ／ＭＳ分析,在患者胃内容物和血中检出速可眠,在眼药３３ｈ尿内可检出速可眠原型药物以及四个代谢产物。并用外标法对生物样品中速可眠进行定量测定,对临床救治起到了积极作用。     

用水热法在铁铬铝合金片上原位合成MCM-22沸石膜

 采用水热法在铁铬铝合金片载体上原位合成了MCM-22沸石膜,并采用X射线衍射和扫描电子显微镜对沸石膜进行了表征,探讨了成膜的影响因素. 结果表明,载体预处理条件对合成沸石膜的品质有较大的影响. 载体仅经碱处理后合成的沸石膜稀疏而不连续; 载体先经碱处理再经酸处理后可得到连续致密的沸石膜,且晶片取向均一; 载体预先涂覆Al2O3胶过渡层后制得的MCM-22沸石膜经超声波清洗后不会脱落,表明沸石膜与载体间的结合力增强. 此外,增大晶化母液量有利于沸石膜的生长.     

硅探测器的数字化脉冲形状甄别

介绍了利用硅探测器的脉冲形状甄别进行粒子鉴别的原理。详细叙述了基于数字化方法的脉冲形状甄别的实现。采样频率和位数是数字化方法的两个重要参数。对于硅探测器信号,采用100 MS/s,12 bit的Digitizer可以满足脉冲形状甄别法对时间分辨的要求。同时对该方法粒子鉴别的特征和能量阈值做了简要的分析和对比。粒子背面入射硅探测器的所得的阈值低于正面入射的情况。例如对于氖周围的同位素,背面入射情况的阈值约为100 MeV,为正面入射情况下鉴别阈值的二分之一,相当与ΔE-E方法中ΔE探测器厚度约为60 μm情况下的阈值。最后定性讨论了硅探测器的电阻率不均匀性和沟道效应对粒子鉴别性能的影响。In this paper Pulse Shape Discrimination(PSD) for silicon detector has been briefly introduced. The emerging digital method successfully applied to detector signal processing makes digital PSD method one of the most promising particle identification methods. Sampling frequency and the number of bits are two key parameters of digital method. For silicon detector signal, adopting 100 Ms/s, 12 bit Digitizer can satisfy the time resolution requirement of PSD method. The identification characteristic and energy threshold of this method have been discussed and compared with both front injection and rear injection cases. Energy threshold with rear injection usually is much lower than that with front injection. For example, around for Neon isotope energy threshold with rear injection is about 100 MeV which is only half of the threshold with front injection, also equivalent to thickness of about 60 μm silicon detector threshold in ΔE-E method. At the end the impact of silicon detector's resistivity nonuniformity and channel effect on the identification capacity of PSD method has been discussed in detail.     

约束优化的一个改进的强次可行SQP算法及数值试验

本文对约束优化一个强次可行SQP算法进行改进,使之产生的迭代点在有限次迭代后全落入可行域;并对算法数值效果进行了大量的比较试验.     

Effect of compressed CO2 on the critical micelle concentration and aggregation number of AOT reverse micelles in isooctane

The effect of compressed CO2 on the critical micelle concentration (cmc) and aggregation number of sodium bis-2-ethylhexylsulfosuccinate (AOT) reverse micelles in isooctane solution was studied by UV/Vis and fluorescence spectroscopy methods in the temperature range of 303.2-318.2 K and at different pressures or mole fractions of CO2 (X(CO2)). The capacity of the reverse micelles to solubilize water was also determined by direct observation. The standard Gibbs free energy (DeltaGo(m)), standard enthalpy (DeltaHo(m)), and standard entropy (DeltaSo(m)) for the formation of the reverse micelles were calculated by using the cmc data determined. It was discovered that the cmc versus X(CO2) curve and the DeltaGo(m) versus X(CO2) curve for a fixed temperature have a minimum, and the aggregation number and water-solubilization capacity of the reverse micelles reach a maximum at the X(CO2) value corresponding to that minimum. These results indicate that CO2 at a suitable concentration favors the formation of and can stabilize AOT reverse micelles. A detailed thermodynamic study showed that the driving force for the formation of the reverse micelles is entropy.     

Surfactant-directed assembly of mesoporous metal-organic framework nanoplates in ionic liquids

Mesoporous MOF nanoplates were formed in surfactant-IL solutions. This method is simple, requires less energy, and is environmental friendly, and can be easily applied to the synthesis of other MOFs with different morphologies and porosities.