Multicomponent One-pot Diastereoselective Synthesis ofBiologically Important Scaffold under Microwaves

A simple and fast three-component diastereoselective synthesis of biologically important spiro scaffold 4 wascarried out in reasonable purity starting from readily available 1H-indole-2,3-dione 1,ethyl cyanoacetate 2 and4-hydroxycoumarin 3 under microwave in high yield(88%-92%)and short time.     

A three component one-pot synthesis of N-amino-2-pyridone derivatives catalyzed by KF-Al2O3

Synthesis of 1,6-diamino-4-phenyl-3,5-dicyano-2-pyridone derivatives via a one-pot, three-component reaction of aryl aldehydes, malononitrile, and cyanoacetic hydrazide at room temperature using KF-Al₂O₃ as a recyclable catalyst have been developed. The reaction proceeds through the initial Knoevenagel condensation between aldehyde and malononitrile in the presence of KF-Al₂O₃ to form the benzylidene derivative which then undergoes Michael addition with cyanoacetic hydrazide followed by intramolecular cyclization of the resulting intermediate to produce the N-amino-2-pyridones in good to excellent yields. The structure of the synthesized compounds were characterized and established on the basis of their spectral data analysis and single-crystal XRD analysis.     

PCA-LVQ法及其在RS-FTIR大气环境监测数据处理中的应用

将主成分分析(PCA)用于遥感傅里叶变换红外光谱(Remote Sensing Fourier Transform Infrared:RS-FTIR)的特征提取,结合学习矢量量化(LVQ)神经网络,实现了PCA-LVQ对大气中的8组分混合体系进行快速定性分析的建模方法。并与单纯的LVQ神经网络、反向传播人工神经网络(BP-ANN)得到的结果进行了比较。PCA-LVQ显示出较好的处理数据的能力,它不仅提高了运算速度,而且提高了模型的预测准确度,分类精度达到91.7%。PCA-LVQ的这一预测精度及运算速度,足以满足遥感傅里叶变换红外光谱对大气中有毒气体的实时、在线监测的需要。     

Palladium‐Catalyzed Multi‐Component Reactions of N‐Tosylhydrazones, 2‐Iodoanilines and CO2 towards 4‐Aryl‐2‐Quinolinones

A palladium‐catalyzed three‐component reaction between N‐tosylhydrazones, 2‐iodoanilines and atmospheric pressure CO₂ was developed whereby a tandem carbene migration insertion/lactamization strategy afforded 4‐aryl‐2‐quinolinones in moderate to good yields. Notably, a wide range of functional groups were tolerated in this procedure. This protocol features the simultaneous formation of four novel bonds; two C?C, one C=C and one C?N (amide), representing an efficient methodology for incorporation of CO₂ into heterocycles.     

Proposal for Fourier-Transform Phase-Modulation Fluorometer

I propose a concept of a novel Fourier-transform phase-modulation fluorometer by which a fluorescence decay waveform can be obtained. In the fluorometer, the modulation frequency of the excitation light source is swept continuously from a start frequency f_min to an end frequency f_max with a time duration T. The resultant fluorescence signal waveform is Fourier-transformed to obtain amplitude and phase spectra. The ratio of the amplitude spectrum and the difference of the phase spectrum over those of the reference spectra that are obtained from a non-fluorescent material are calculated, respectively, and the pair of both spectral data is inverse-Fourier-transformed again to obtain the fluorescence decay waveform. To verify and demonstrate the effectiveness of the concept, I carried out (1) numerical simulations, (2) determination of a time constant of a passive resistor-capacitor (RC) differential circuit, and (3) measurement of a fluorescent decay waveform of YAG materials packed in Nichia’s white LED.     

Non-Covalent Reactions Supporting Antiviral Development

Viruses are the current big enemy of the world’s healthcare systems. As the small infector causes various deadly diseases, from influenza and HIV to COVID-19, the virus continues to evolve from one type to its mutants. Therefore, the development of antivirals demands tremendous attention and resources for drug researchers around the world. Active pharmaceutical ingredients (API) development includes discovering new drug compounds and developing existing ones. However, to innovate a new antiviral takes a very long time to test its safety and effectiveness, from structure modeling to synthesis, and then requires various stages of clinical trials. Meanwhile, developing the existing API can be more efficient because it reduces many development stages. One approach in this effort is to modify the solid structures to improve their physicochemical properties and enhance their activity. This review discusses antiviral multicomponent systems under the research phase and has been marketed. The discussion includes the types of antivirals, their counterpart compound, screening, manufacturing methods, multicomponent systems yielded, characterization methods, physicochemical properties, and their effects on their pharmacological activities. It is hoped that the opportunities and challenges of solid antiviral drug modifications can be drawn in this review as important information for further antiviral development.     

30K～60K温区混合工质内复叠节流制冷循环及其实验验证

本文提出了利用内复叠节流制冷循环获得３０Ｋ－６０Ｋ温区的新制冷方案。进行了与之相关的热力学问题分析，建立了实验装置，首次获得了５０Ｋ左右的低温。     

Reliability inference with extended sequential order statistics

In this article, we will address the complexity of non-identical components in multi-component systems. Most technical systems can be described as such since either component types or component functions within the system vary amongst components. While most reliability related work resorts to the assumption of homogeneous components, we aim to address the often more realistic assumption of heterogeneous components extending the model of Extended Sequential Order Statistics by two inferential methods. Firstly, the derivation of Maximum Likelihood Estimates including a simulation study demonstrating their good performance for large enough sample size. Secondly, we introduce a likelihood ratio test to test whether components can be assumed identical accompanied by a power study. Both methods are powerful tools in reliability contexts. The former increases our understanding of component behaviour, especially upon failure of other components. This knowledge empowers system operators to make better decisions regarding maintenance schedules and failure time prediction. The latter supports operators in their quest of identifying component equivalence. Therefore, both methods can be used to achieve meaningful results in real life applications.     

轮胎橡胶多组分分析方法的研究

轮胎橡胶物证是涉车案件中常见物证,对于相关案件的侦破具有重要的物证价值。本文根据轮胎橡胶组分体系的特点,设计了以大型仪器为主线的多组分分析方案。所选用的仪器设备及方法有:裂解气相色谱仪(Py-GC)、裂解气相色谱与质谱联用仪(Py-GCMS)、差示扫描量热仪(DSC)、热重分析仪(TGA)、原子吸收分光光度计(AAS)、化学法;实验中,测试了轮胎橡胶的胶型、配合剂定性(防老剂定性、促进剂定性、其他助剂定性)、玻璃化温度,焓值,高聚物含量、配合剂含量、炭黑含量、无机填料(盐酸不溶物、氧化锌含量、二氧化硅含量)、硫含量等十三个测试项目;并将已知配方的硫化胶理论值与测试样品结果比对分析。分析结果表明:建立的系列方法的测试结果准确、可靠,可以为轮胎橡胶的分析鉴别提供技术支持。     

应用多介质PPM方法计算斜激波与物质交界面的相互作用

利用多介质PPM方法研究斜激波与物质交界面的相互作用.采用与体积分数耦合的Euler方程组作为计算模型,用双波近似来求解一般刚性气体状态方程Riemann问题.通过体积分数的计算来获得界面的位置,在整个流场采用统一的高阶PPM格式进行计算.文中对斜激波与不同物质界面相互作用进行了数值模拟,并给出了交界面上由于斜压效应产生的涡列的演化过程,特别是强斜激波与不同物质界面的相互作用的情况.