美托洛尔的合成工艺研究

本文以价廉易得的对羟基苯乙酸甲酯为原料,通过酚羟基苄基保护、酯键还原、甲基化、脱苄基得到关键中间体对甲氧基乙基苯酚5,再与环氧氯丙烷发生烷基化反应,最后与异丙胺反应开环得到美托洛尔。对于合成路线中的关键步骤进行了工艺优化,分步平均收率高达89.3%,6步反应总收率也高达48%。中间体及目标化合物均通过~1HNMR和~(13)CNMR确证了结构。该方法具有原料易得、合成步骤短、收率高以及易于工业化制备等优点。     

氢元素发现史中定量推理的作用

定量推理是应用数学知识来分析解释数据、得出结论,以解决跨学科背景下的复杂问题。定量推理将数学和学科专业知识整合在一起,属于高阶思维能力。引导学生发展定量推理能力对化学学科核心素养目标的达成具有重要意义。以氢元素的发现历程为例,阐述了定量推理在科学探究过程中的关键作用。     

具连续变量的偶数阶中立型差分方程的振动性

研究具有连续变量的偶数阶中立型时滞差分方程的解的振动性,给出了有界解振动的几个充分条件.     

超高效液相色谱-质谱法快速分析番茄及其制品中矮壮素和缩节胺残留量

采用超高效液相色谱-串联质谱(UPLC/MS-MS)研究了番茄及其制品中矮壮素和缩节胺残留量的测定方法。样品用水提取,无需经过任何净化过程;在粒径为1.7μm的超高压亲水作用色谱柱上以V(乙腈)∶V(含0.1%甲酸的10 mmol/L乙酸铵溶液)=6∶4为流动相,等度洗脱分离;电喷雾正离子检测(ESI ),多反应监测模式(MRM)对定性和定量离子进行MS测定。结果表明:矮壮素和缩节胺的添加水平在5、10和20μg/kg时,回收率范围分别为78.5%~90.1%和80.0%~104.0%;相对标准偏差在9.5%~11.3%和10.5%~13.2%之间;方法检出限均为0.8μg/kg。本方法仅需约2 m in的检测时间,且灵敏、准确,完全满足番茄及其制品中矮壮素和缩节胺残留量的快速、高灵敏度的分析要求。     

基于FPGA的红外图像仿真注入系统

设计了一种新的图像注入系统来实现PC机仿真图像到红外处理系统的直接传输。首先,该系统利用USB2.0接收PC机对外场实测数据仿真得到的BMP格式文件,用FPGA控制由两个SDRAM组成的缓冲模块进行图像缓存,然后通过Camera Link接口传送出去。系统数据缓存采用乒乓操作,避免了数据处理时无法持续接收而丢失有效数据的现象。测试时用图像采集卡进行图像采集并显示。结果表明,该系统具有速度快、实时性好、稳定性高等特点,可替代光电跟瞄设备进行仿真训练及设备的动态检验。     

The entanglement properties of holographic QCD model with a critical end point

We investigated different entanglement properties of a holographic QCD(hQCD)model with a critical end point at the finite baryon density.Firstly,we considered the holographic entanglement entropy(HEE)of this hQCD model in a spherical shaped region and a strip shaped region.It was determined that the HEE of this hQCD model in both regions can reflect QCD phase transition.Moreover,although the area formulas and minimal area equations of the two regions were quite different,the HEE exhibited a similar behavior on the QCD phase diagram.Therefore,we assert that the behavior of the HEE on the QCD phase diagram is independent of the shape of the subregions.However,the HEE is not an ideal parameter for the characterization of the entanglement between different subregions of a thermal system.As such,we investigated the mutual information(MI),conditional mutual information(CMI),and the entanglement of purification(Ep)in different strip shaped regions.We determined that the three entanglement quantities exhibited some universal behavior;their values did not change significantly in the hadronic matter phase but increased rapidly with the increase in T andμin the QGP phase.Near the phase boundary,these three entanglement quantities changed smoothly in the crossover region and continuously but not smoothly at CEP;they exhibited discontinuous behavior in the first phase transition region.These properties can be used to distinguish between the different phases of strongly coupled matter.     

HL-2A装置ECRH的微波强度分布测量与分析

利用红外热像仪测量微波传播路径上的三个不同距离截平面上的微波强度分布,计算出辐射图的一阶及二阶矩并重建相位信息,可以确定微波波束的强度分布和准直度。使用该方法对两套ECRH系统传输线进行了定量的分析,获得了微波强度分布均为高斯分布、7m 3^#传输线的微波束线准直度为0.05°、6m 4^#传输线微波束线准直度为0.14°的结果。     

Locating the QCD critical end point through peaked baryon number susceptibilities along the freeze-out line

We investigate the baryon number susceptibilities up to fourth order along different freeze-out lines in a holographic QCD model with a critical end point(CEP), and we propose that the peaked baryon number susceptibilities along the freeze-out line can be used as a clean signature to locate the CEP in the QCD phase diagram.On the temperature and baryon chemical potential plane, the cumulant ratio of the baryon number susceptibilities(up to fourth order) forms a ridge along the phase boundary, and develops a sword-shaped "mountain" standing upright around the CEP in a narrow and oblate region. The measurement of baryon number susceptibilities from heavy-ion collision experiments is along the freeze-out line. If the freeze-out line crosses the foot of the CEP mountain, then one can observe the peaked baryon number susceptibilities along the freeze-out line, and the kurtosis of the baryon number distributions has the highest magnitude. The data from the first phase of the beam energy scan program at the Relativistic Heavy Ion Collider indicates that there should be a peak of the kurtosis of the baryon number distribution at a collision energy of around 5 Ge V, which suggests that the freeze-out line crosses the foot of the CEP mountain and the summit of the CEP should be located nearby, around a collision energy of 3–7 GeV.     

Scalar mesons and glueballs in Dp-Dq hard-wall models

We investigate the light scalar mesons and glueballs in the Dp-Dq hard-wall models, including D3-Dq, D4-Dq, and D6-Dq systems. It is found that only in the D4-D6 and D4-Ds hard-wall models are the predicted masses of the clq scalar meson fo scalar glueball consistent with their experimental or lattice results. This indicates that D4-D6 and D4-Ds hard-wall models are the favorite candidates of the realistic holographic QCD model.     

Scalar mesons and glueballs in D_p-D_q hard-wall models

We investigate the light scalar mesons and glueballs in the Dp-Dq hard-wall models, including D3-Dq, D4-Dq, and D6-Dq systems. It is found that only in the D4-D6 and D4-D8 hard-wall models are the predicted masses of the qˉq scalar meson f0 scalar glueball consistent with their experimental or lattice results. This indicates that D4-D6 and D4-D8 hard-wall models are the favorite candidates of the realistic holographic QCD model.