Properties and carbonization behavior of asphalt modified with the THF-soluble fraction of a coal liquefaction residue

This study focuses on the effects of the tetrahydrofuran-soluble fraction of direct coal liquefaction residue as a modifier to modify asphalt with formaldehyde. The properties and carbonization behavior of matrix asphalt and the modified asphalts were studied. The results indicate that the ductility properties of modified asphalts have been effectively improved. The morphology of modified asphalts without the addition of formaldehyde is a set of uniform distribution point, and it is converted from linear distribution to clustered distribution observed in fluorescence microscope images with the increase of the adding amount of formaldehyde.     

Enantioselective Construction of Cyclic Enaminone‐Based 3‐Substituted 3‐Amino‐2‐oxindole Scaffolds via Catalytic Asymmetric Additions of Isatin‐Derived Imines

The first catalytic asymmetric construction of the cyclic enaminone‐based 3‐substituted 3‐amino‐2‐oxindole scaffold with potential bioactivity has been developed via chiral phosphoric acid‐catalyzed enantioselective addition reactions of cyclic enaminones to isatin‐derived imines, which afforded a series of cyclic enaminone‐based 3‐substituted 3‐amino‐2‐oxindoles in high yields and excellent enantioselectivities (up to 99% yield, 97% ee). The investigation of the reaction mechanism suggested that it was facilitated by a dual hydrogen‐bonding activation mode between the two substrates and the chiral phosphoric acid. Besides, this method could be utilized for a large‐scale synthesis with maintained enantioselectivity. This approach will not only offer a useful method for enantioselective construction of the cyclic enaminone‐based 3‐substituted 3‐amino‐2‐oxindole scaffold, but also enrich the research on catalytic asymmetric addition reactions of isatin‐derived imines by using electron‐rich olefins as nucleophiles. More importantly, a preliminary evaluation on the cytotoxicity of some selected products revealed that two of the enantio‐pure compounds exhibited moderate to strong cytotoxicity to A549, 786‐0, ECA109 and BT474 cancer cell lines.

     

Synthesis of Polymer Nanospheres Conjugated Ce (IV) Complexes for Constructing Double Antibacterial Centers

Journal of Inorganic and Organometallic Polymers and Materials - The antimicrobial materials are rapidly emerging as a primary component in mitigation of bacterial pathogens, and functional...     

Genomic and metabolomic analysis of Bacillus licheniformis with enhanced poly-γ-glutamic acid production through atmospheric and room temperature plasma mutagenesis

Poly-γ-glutamic acid is an extracellular polymeric substance with various applications owing to its valuable properties of biodegradability, flocculating activity, water solubility, and nontoxicity. However, the ability of natural strains to produce poly-γ-glutamic acid is low. Atmospheric and room temperature plasma was applied in this study to conduct mutation breeding of Bacillus licheniformis CGMCC 2876, and a mutant strain M32 with an 11% increase in poly-γ-glutamic acid was obtained. Genome resequencing analysis identified 7 nonsynonymous mutations of ppsC encoding lipopeptide synthetase associated with poly-γ-glutamic acid metabolic pathways. From molecular docking, more binding sites and higher binding energy were speculated between the mutated plipastatin synthase subunit C and glutamate, which might contribute to the higher poly-γ-glutamic acid production. Moreover, the metabolic mechanism analysis revealed that the upregulated amino acids of M32 provided substrates for glutamate and promoted the conversion between L- and D-glutamate acids. In addition, the glycolytic pathway is enhanced, leading to a better capacity for using glucose. The maximum poly-γ-glutamic acid yield of 14.08 g·L^–1 was finally reached with 30 g·L^–1 glutamate.     

Protein A Detection Based on Quantum Dots-Antibody Bioprobe Using Fluorescence Coupled Capillary Electrophoresis

In this report, fluorescence detection coupled capillary electrophoresis (CE-FL) was used to detect Protein A. Antibody was first labeled with Cy5 and then mixed with quantum dots (QDs) to form QDs-antibody bioprobe. Further, we observed fluorescence resonance energy transfer (FRET) from QDs donor to Cy5 acceptor. The bioprobe was formed and brought QDs and Cy5 close enough to allow FRET to occur. After adding protein A, the FRET system was broken and caused the FRET signal to decrease. Thus, a new method for the determination of protein A was proposed based on the FRET signal changes. This study provides a new trail of thought for the detection of protein.     

市政道路施工中软基加固技术的应用分析

软土基处理的质量好坏既可以对市政道路路基具有的基础承载力有着直接的影响,还可以确保市政道路建设完工后的高效运行以及安全运营。反之则会导致出现地基失稳的情况,从而使道路出现不均匀沉降以及沉降过大的情况,并严重危害着市政道路。     

关于小区给排水工程中质量问题的探讨

笔者结合自己的建筑工程施工实践经验,针对小区给排水工程中比较常见的质量问题进行了简单地介绍,并对问题提出了行之有效的预防和处理措施。     

设备闸门提升与导向装置运行特性仿真分析

对核电厂设备闸门提升与导向装置在设备闸门封头开启与关闭过程中的运动特性进行了分析研究,该研究借助动力学仿真软件ADAMS展开,分别对提升与导向装置可能出现的同步提升操作和不同步提升操作两种工况进行了仿真分析。分析结果表明:在同步提升操作工况下,设备闸门封头两侧导向箱位移一致,提升与导向装置不会产生卡滞;在不同步提升操作工况下,设备闸门封头两侧导向箱最大允许高度差为54 mm,否则提升与导向装置将产生卡滞。     

控制棒落棒动力学数值计算

控制棒在安全停堆时的下落时间和下落规律是核电厂安全分析的重要参数。本文针对一种超临界水冷堆控制棒组件,采用计算流体动力学(CFD)瞬态动网格数值分析方法研究某控制棒的下落过程,分析其流场演化规律,并得到了控制棒下落过程中位移随时间、速度随时间及加速度随时间的变化规律。同时,研究了控制棒、通道发生变形时对控制棒下落规律的影响。本文的计算方法及结果对控制棒结构优化具有指导意义。