有机化学实验的教学体会及改革探索

文章基于个人的教学及科研理念,阐述了有机化学实验教学过程中的一些体会及改革尝试。引导学生认识每种实验手段的局限性,并针对特定实验目的改善实验流程;把各种有机实验类型联系起来,利用综合性实验,强化学生完整实验流程的概念;简化考核方式,减少学生实验劳动量,促使学生在掌握基本操作技能的同时,培养全面、综合性的思维方式。上述尝试在教学过程中取得了不错的效果。     

高档次不锈钢(焊)管的制造与订购——美国Plymouth Tube公司的经验和对美国标准的系统解读

介绍了美国Plymouth Tube公司的生产经验,并分析讨论了所涉美国不锈钢焊接钢管标准的系统特征。分析认为:美国ASTM/ASME不锈钢钢管(材)标准由产品标准和通用材质标准组成;ASTM技术标准(正文部分)实际上只规定了不锈钢钢管的最低设计和检验要求,仅按照该标准未必能订购到质量有保证的优质钢管;ASTM/ASME不锈钢钢管(材)标准不仅在不断补充新品种和新内容,也经常在纠正各种错误或修正认识;全面系统地解读美国标准,对我国不锈钢(焊)管的生产、销售和订购十分有益。     

基于ADAMS/View的弧焊机器人运动精度可靠性分析方法

弧焊机器人各部分的传动精度会对焊枪的行走精度产生累积误差,影响焊接质量,因此有效控制其传动精度和各类随机误差成为提高设计质量的关键.文中提出一种弧焊机器人运动精度可靠性分析方法.基于ADAMS/View软件虚拟平台,建立弧焊机器人参数化虚拟试验样机,利用乘同余法编写正态分布伪随机数子函数程序,模拟机构的各种随机误差分布,实现样机的Monte Carlo参数化,从而随机建立虚拟样机进行模拟计算,获取焊接过程动态特性大样本试验数据,统计试验数据并求取其运动可靠度.结果表明,该方法不必建立复杂的机构运动学数学模型,能有效提高设计效率和精度.     

Screening of β1- and β2-Adrenergic Receptor Modulators through Advanced Pharmacoinformatics and Machine Learning Approaches

Cardiovascular diseases (CDs) are a major concern in the human race and one of the leading causes of death worldwide. β-Adrenergic receptors (β1-AR and β2-AR) play a crucial role in the overall regulation of cardiac function. In the present study, structure-based virtual screening, machine learning (ML), and a ligand-based similarity search were conducted for the PubChem database against both β1- and β2-AR. Initially, all docked molecules were screened using the threshold binding energy value. Molecules with a better binding affinity were further used for segregation as active and inactive through ML. The pharmacokinetic assessment was carried out on molecules retained in the above step. Further, similarity searching of the ChEMBL and DrugBank databases was performed. From detailed analysis of the above data, four compounds for each of β1- and β2-AR were found to be promising in nature. A number of critical ligand-binding amino acids formed potential hydrogen bonds and hydrophobic interactions. Finally, a molecular dynamics (MD) simulation study of each molecule bound with the respective target was performed. A number of parameters obtained from the MD simulation trajectories were calculated and substantiated the stability between the protein-ligand complex. Hence, it can be postulated that the final molecules might be crucial for CDs subjected to experimental validation.     

ASME BPVC.V-2019对无损检测人员的要求

从范围,定义,无损方法及取证要求等方面介绍了ASME BPVC.V-2019对无损检测人员的要求相较于2016版的变化,并指出修订细则时应注意的事项,为相关工作提供参考.     

高速机床进给系统的发展趋势

在明确了高速加工对机床进给进给系统要求的基础上，比较和分析了滚珠丝杠、直线电机和并联虚拟轴机构等三种高速进给系统的性能、特点、存在问题及其解决办法，指出了它们各自的适用范围和应用前景。     

基于萤火虫群算法的虚拟演播室箱体焊接优化

针对求解虚拟演播室复杂的箱体焊接结构最优焊接顺序难的问题,采用热-机耦合非线性热弹塑性有限元计算模型,对焊接顺序进行优化数值模拟,提出了一种通过萤火虫算法优化从而得到虚拟演播室箱体最优焊接顺序的方法.该方法选择焊接变形量为目标函数,提出了求解最优焊接顺序的萤火虫算法优化模型,设计了基于萤火虫群算法的焊接顺序优化算法.优化结果表明,该方法求解的最优焊接顺序的焊接变形量小,变化率小,该方法要比传统的经验或者试验方法更快,更精确,效果更好.     

陶瓷企业文化建设体会与思考

什么是企业文化,陶瓷企业如何开展企业文化建设,结合其工作实践分析了企业文化建设的作用力,提出陶瓷企业文化价值观的思考。     

Thiobarbiturates as sirtuin inhibitors: virtual screening, free-energy calculations, and biological testing

NAD+-dependent histone deacetylases (sirtuins) are enzymes that cleave acetyl groups from lysine residues in histones and other proteins. Potent selective sirtuin inhibitors are interesting tools for the investigation of the biological functions of these enzymes and may be future drugs for the treatment of cancer or neurodegenerative diseases. Herein we present the results from a protein-based virtual screen of a commercial database with subsequent biological testing of the most promising compounds. The combination of docking and in vitro experimental testing resulted in the identification of novel sirtuin inhibitors with thiobarbiturate structure. To rationalize the experimental results, free-energy calculations were carried out by molecular mechanics Poisson-Boltzmann/surface area (MM-PBSA) calculations. A significant correlation between calculated binding free energies and measured Sirt2 inhibitory activities was observed. The analyses suggested a molecular basis for the interaction of the identified thiobarbiturate derivatives with human Sirt2. Based on the docking and MM-PBSA calculations we synthesized and tested five further thiobarbiturates. The MM-PBSA method correctly predicted the activity of the novel thiobarbiturates. The identified compounds will be used to further explore the therapeutic potential of sirtuin inhibitors.     

函数发生器的仿真设计与电路实现

以多波形函数发生器的设计为例,阐述理论分析、仿真设计和硬件实现相结合的电子电路设计方式。对函数发生器进行方案论证、单元电路设计,借助Multisim仿真软件建立仿真模型、进行仿真分析、优化设计方案,通过电路板制作、整体调试和性能指标测量完成硬件实现。实践表明,把虚拟仿真和硬件实现相结合,为提高电子电路设计质量和效率提供了一个有效手段,传统的设计方式与EDA技术的有机结合,将形成一种优越的创新性电子电路设计方式。