Syntheses and Crystal Structures of Two New α-Aminophosphonate Derivatives Containing Thieno[2,3-d]pyrimidine

Two new α-aminophosphonate derivatives containing thieno[2,3-d]pyrimidine, diethyl(((6-ethyl-2-methyl-4-oxothieno[2,3-d]pyrimidin-3(4H)-yl)amino)(4-methoxyphenyl)methyl)phosphonate(1) and diethyl((4-bromophenyl)((6-ethyl-2-methyl-4-oxothieno[2,3-d]pyrimidin-3(4H)-yl)amino)methyl)phosphonate(2), have been synthesized by a facial phosphorylated reaction, and their structures were characterized by NMR, IR, HRMS and X-ray single-crystal diffraction. Compound 1(C21H28N3O5PS, Mr = 465.49) belongs to the orthorhombic system, space group P212121, with a = 10.83653(16), b = 12.04906(19), c = 18.0061(3) , V = 2351.06(6) 3, Z = 4, Dc = 1.315 g/cm3, μ = 2.177 mm-1, F(000) = 984.0, the final R = 0.0389 and w R = 0.0985 for all data. Compound 2(C20H25Br N3O4 PS, Mr = 514.37) belongs to the orthorhombic system, space group P212121, with a = 10.9187(5), b = 11.9522(4), c = 17.7667(7) , V = 2318.60(16) 3, Z = 4, Dc = 1.474 g/cm3, μ = 4.175 mm-1, F(000) = 1056.0, the final R = 0.0367 and w R = 0.0946 for all data.     

碳点-荧光桃红荧光共振能量转移体系在铜离子检测中的应用研究

在pH 8.4的溶液中,碳量子点(Carbon quantum dots,CQDs)和荧光桃红(Fluorescent pink,FP)之间发生荧光共振而使后者的荧光增强。体系中加入痕量Cu2+后,FP的荧光被猝灭,且在一定范围内体系的荧光猝灭程度与Cu2+浓度呈良好的线性关系。据此建立了荧光猝灭法测定河水、农田水、自来水中痕量Cu2+的新方法。方法的线性范围为9.42~23.55μmol/L,检出限(3σ/k)为3.14μmol/L。将该方法应用于河水、农田水及自来水中Cu2+的检测,其相对标准偏差(RSD)不大于0.91%,加标回收率为98.7%~99.0%,结果令人满意。     

电感耦合等离子体质谱法测定拉考沙胺注射液中10种杂质元素

拉考沙胺注射液样品用稀释剂定容至100.0mL,采用电感耦合等离子体质谱法测定样品溶液中锂、钒、钴、镍、铜、砷、镉、锑、汞、铅等10种杂质元素的含量。采用内标法定量,10种杂质元素的检出限(3s/k)为0.002~0.040μg·L^-1,测定下限(10s/k)为0.007~0.120μg·L^-1。以空白样品为基体进行加标回收试验,所得回收率为95.2%~124%,测定值的相对标准偏差(n=6)为1.0%~2.5%。通过风险评估和每日最大推荐剂量,确定了拉考沙胺注射液中各杂质元素的每日允许暴露量与各杂质元素的含量限度。     

一类无限Cernikov p-群的自同构群北大核心CSCD

设G是无限Cernikov p-群,且G的每个真商群是Abel群,但G不是Abel群,本文确定了G的自同构群.     

Effect on the flow and heat transfer characteristics for sinusoidal pulsating laminar flow in a heated square cylinder

Two-dimensional numerical simulation is performed to understand the effect of flow pulsation on the flow and heat transfer from a heated square cylinder at Re = 100. Numerical calculations are carried out by using a finite volume method based on the pressure-implicit with splitting of operators algorithm in a collocated grid. The effects of flow pulsation amplitude (0.2 ≤ A ≤ 0.8) and frequency (0 ≤ f _p  ≤ 20 Hz) on the detailed kinematics of flow (streamlines, vorticity patterns), the macroscopic parameters (drag coefficient, vortex shedding frequency) and heat transfer enhancement are presented in detail. The Strouhal number of vortices shedding, drag coefficient for non-pulsating flow are compared with the previously published data, and good agreement is found. The lock-on phenomenon is observed for a square cylinder in the present flow pulsation. When the pulsating frequency is within the lock-on regime, time averaged drag coefficient and heat transfer from the square cylinder is substantially augmented, and when the pulsating frequency in about the natural vortex shedding frequency, the heat transfer is also substantially enhanced. In addition, the influence of the pulsating amplitude on the time averaged drag coefficient, heat transfer enhancement and lock-on occurrence is discussed in detail.     

氧化石墨烯纳米粒与牛血清白蛋白的相互作用

采用荧光光谱法研究氧化石墨烯纳米粒(NGO)对牛血清白蛋白(BSA)的作用机制.实验结果表明:NGO对BSA的荧光猝灭类型为动态猝灭为主的静动态混合猝灭.T=283、298、310K时,二者最小结合常数分别为6.7×109、9.5×107、2.1×106L·mol-1.结合位点数分别为2.12、1.32、0.87.由热力学参数确定NGO与BSA之间作用类型为氢键和范德华力.NGO对BSA中色氨酸残基荧光猝灭,不改变酪氨酸残基荧光发射强度,但降低其所处环境的疏水性.     

樟帮法炮制吴茱萸样品的指纹图谱

建立樟帮法炮制吴茱萸样品的液相色谱指纹图谱.采用HPLC研究樟帮法炮制吴茱萸样品的指纹图谱,以Diamonsil C18(250mm×4.6mm,5μm)为色谱柱,在乙腈-0.4％磷酸水溶液下梯度洗脱,流速为1.0mL/min,检测波长为327nm.10批不同来源的吴茱萸药材及其炮制品各色谱峰分离较好,获得19个共有色谱峰.方法所建立的HPLC指纹图谱能较好地识别樟帮法炮制吴茱萸样品,为吴茱萸药材及其炮制品质量控制提供依据.     

三纠缠原子与双模腔场相互作用系统的纠缠演化特性

研究了初始处于GHZ态的三个两能级原子与双模腔场相互作用系统的纠缠动力学特性,得到了并发度和线性熵的解析表达式.讨论了腔场初始纠缠度对腔内两原子之间纠缠的影响,对其余子系统求迹后结果表明腔内两原子之间的纠缠出现突然产生现象,腔内两原子之间产生纠缠的阈值时间和最大值依赖于双模腔场初始纠缠度;并且发现腔内两原子子系统和腔外原子与场子系统之间在整个的时间演化过程中一直保持着纠缠状态.     

奇异半线性椭圆问题解的存在与不存在性(英文)

本文研究了奇异半线性椭圆问题.利用上下解方法,获得了该问题解的一个存在性和不存在性结果.     

空间相机光学窗口热光学性能的仿真分析

 空间相机光学窗口与周围环境进行热交换,导致窗口的温度发生不均匀变化,包括整体温度水平的变化以及产生径向温差、周向温差和轴向温差。这些温度梯度将影响相机的光学系统质量。针对某相机光学窗口温度分布不均匀的特点,提出利用非顺序光路建立复杂光瞳的方法对光学窗口进行分区,在各子区域上建立温度的径向分布特征,然后将各子区域的变化再统一到整个元件中,进而评判对整个系统的影响。结果表明,新方法合理可行,温度周向不均匀分布会降低光学系统质量,并且不能完全通过离焦来补偿。