"交叉学科"选题下的本科毕业论文的质量提升与探讨——以生物医用高分子材料为例

随着国家对人才培养要求的提高,各高校对本科生培养质量的重视程度提到新的高度,而本科毕业论文在本科生培养体系里占据极其重要的地位.交叉学科由于具有不同学科之间相互交叉、融合、渗透的特点,因此交叉学科选题对于本科生及指导教师提出了更高的要求,本文以生物医用高分子材料为例,从毕业论文选题的合理性、开题的目标和任务、实验指导思路与方法以及论文撰写的规范性四个方面着重探讨,并提出相关合理性意见,为促进交叉学科毕业论文质量的提高具有一定的借鉴意义.     

药物化学课程全英文教学的探索与实践*

药物化学课程是药学类专业的核心课程,在高等院校中开展药物化学课程的全英文教学,对提高药学拔尖人才的综合素质和推动我国制药行业的发展都具有重要的意义。针对药物化学课程全英文教学过程中的难点,在教材选择、教学内容优化、教学方法改进等方面进行了实践与探索,并取得了良好的教学效果,为药物化学课程全英文教学改革提供了参考。     

国内外“物质的量”主题教学研究现状述评

分别以“Web of Science”与“中国知网”数据库为检索源,对2000—2020年间国内外“物质的量”主题研究论文进行检索,根据论文的研究内容进行分类归纳。研究表明:目前“物质的量”主题教学研究主要涉及:概念历史考量、教材研究、教师发展、学生认知与教学策略研究等5个方面。通过探析国内外的相关研究成果,以期为国内相关研究与实践提供有益借鉴。     

Quantitative Investigation on Structural Evolution of Co-continuous Phase under Shear Flow

Components of co-continuous phase can form an interpenetrating network structure, which has great potential to synergistically improve the mechanical properties of the blends, and to impart the functional blends superior electrical conductivity and permeability. In this work, the effects of shear rates (50–5000 s^?1) at different temperatures on the phase morphology, phase size and lamellar crystallites of biodegradable co-continuous polybutylene terephthalate (PBAT)/polybutylene succinate (PBS) blend are quantitatively investigated. The results show that the above features of the PBAT/PBS have a strong dependence on the shear flow and thermal field. The co-continuous phase of the blend is well maintained at 130 °C. Interestingly, this phase structure transforms into a “sea-island” structure at 160 °C, which gradually recovers to a co-continuous phase when the shear rate increases from 1000 s^?1 to 5000 s^?1. The phase size decreases with the increase of shear rate both at 130 °C and 160 °C due to the refinement and deformation of phase structures caused by strong shear stress. Unexpectedly, a unique phenomenon is observed that the shear-induced lamellar crystallites are oriented perpendicular to shear direction in the range of 500–5000 s^?1 at 130 °C, while the orientation of lamellar crystallites at 160 °C is along the shear direction within the whole range of shear rates. The degree of orientation for the PBAT/PBS blend crystals increases first and then decreases at both temperatures above. In addition, the range of shear rate has reached the level in the industrial processing. Therefore, this work has important guiding significance for the regulation of the co-continuous phase structure and the performance for the blend in the practical processing.

     

Insight into the Excellent Tribological Performance of Highly Oriented Poly(phenylene sulfide)

Achieving low friction and wear of poly(phenylene sulfide)(PPS) without using fillers or blending is a challenging task, but one of considerable practical importance. Here we describe how neat PPS with high tribological performance is achieved by manipulating processing parameters(pressure, flow and temperature). The key to achieving high tribological performance is comparatively high molecular chain orientation, realized in neat PPS, at high shear rates and low pressure. The friction coefficient and wear rate are as low as ~0.3 and~10^-6 mm³·N^-1·m^-1, respectively, which break the record for neat PPS. These values are even better than those for PPS-based blends and comparable to PPS composites. Further studies show, for the first time, that wear rate decreases exponentially with increasing molecular chain orientation, prompting us to revise the classical Archard's law by including the effect of molecular chain orientation. These findings open the possibility of using neat PPS in highly demanding tribological applications.     

铜掺杂钙铝水滑石催化氧化异丙苯制备异丙苯过氧化氢

采用共沉淀法制备了铜掺杂钙铝水滑石Ca₄Cu _x Al-LDHs（x=0,0.1,0.3,0.5,0.8,1.0）,并对其催化异丙苯液相氧化制备异丙苯过氧化氢的活性进行了研究。采用X射线衍射、傅里叶红外光谱、扫描电子显微镜和热分析等手段对Ca₄Cu _x Al-LDHs进行了表征,制备的Ca₄Cu _x Al-LDHs保留了水滑石的片层状结构,铜的掺杂使孔径变小,比表面积增大。当进料比（催化剂/异丙苯）为7.5 mg/mL,反应温度85 ℃,氧气流速为15 mL/min,反应时间7 h,异丙苯的转化率为34.5%,异丙苯过氧化氢的选择性为86.9%,催化剂循环使用5次后,异丙苯的转化率为31.2%,异丙苯过氧化氢的选择性为83.3%。研究为异丙苯过氧化氢开发了新的催化体系。     

基于CoFe(Ⅲ)PBA/GO过氧化物模拟酶化学发光法检测H2O2和抗坏血酸

制备了一种具有过氧化物酶活性的类普鲁士蓝/氧化石墨烯复合纳米材料(CoFe(Ⅲ)PBA/GO)。将具有过氧化物酶活性的CoFe(Ⅲ)PBA/GO和化学发光法相结合,构建了一种用于检测H₂O₂和抗坏血酸(AA)的化学发光分析法。CoFe(Ⅲ)PBA/GO催化H₂O₂产生的O₂·^-,·OH,1O₂自由基氧化Luminol会产生很强的化学发光信号,通过检测化学发光强度可以实现对H₂O₂的检测。该方法检测H₂O₂的线性范围为0~0.8μmol/L,检测限为11 nmol/L。利用AA作为活性氧消除剂可以抑制化学发光反应的特点,实现了AA的检测。该方法测定AA的线性范围为0.02~0.8μmol/L,检测限为20 nmol/L。方法已应用于H₂O₂消毒水中H₂O₂和维生素C片中抗坏血酸的检测。     

碱性电解液中K3[Fe(CN)6]在锌阳极上的自发还原和吸附延长锌镍电池的循环寿命

采用K₃[Fe(CN)₆]作为锌镍电池的电解液添加剂,克服了锌阳极的变形。此外,通过一系列实验设计和表征,探索了电解液中金属锌与K₃[Fe(CN)₆]的反应机理。通过XRD (X-ray diffraction)和XPS (X-ray photo-electron spectroscopy)测试,我们发现金属锌在KOH水溶液中能够与K₃[Fe(CN)₆]反应,将[Fe(CN)₆]^3–还原为[Fe(CN)₆]⁴⁻。添加K₃[Fe(CN)₆]的锌镍电池实现了更长的循环寿命,比不添加K₃[Fe(CN)₆]的锌镍电池长3倍以上。在相同循环次数下,改性电解质中锌阳极循环不仅形状变化较小,而且没有出现“死”锌现象,电极添加剂和粘结剂也没有发生偏析。此外,不同于一般的有机添加剂,K₃[Fe(CN)₆]的加入不仅不会增大电极的极化,还能够提高锌镍电池的放电容量和倍率性能。因此,考虑到这一改性策略有着较高的可行性和较低的成本,K₃[Fe(CN)₆]添加剂在锌镍电池的实际应用中具有极大的推广潜力。     

汉防己甲素全合成研究进展

汉防己甲素是防己科千金藤属植物粉防己中分离提取的双苄基异喹啉类生物碱,已作为临床药物用于抗风湿及阵痛、抗肺癌、抗矽肺。基于粉防己产量的限制及汉防己甲素的需求量增加,深入开展汉防己甲素的全合成研究势在必行。本文按照合成策略,对汉防己甲素的全合成方法进行了综述。      

Modification of PAE-degrading Esterase(CarEW) for Higher Degradation Efficiency Through Integrated Homology Modeling,Molecular Docking,and Molecular Dynamics Simulation

Six phthalate acid esters(PAEs) priority pollutants[dimethyl phthalate(DMP), diethyl phthalate(DEP), dibutyl phthalate (DBP or DNBP), di-n-octyl phthalate(DNOP), di 2-ethyl hexyl phthalate(DEHP), and butyl benzyl phthalate(BBP)] were opted as the research object. PAE-degrading esterase CarEW(PDB ID:1C7I) isolated from Bacillus subtilis acting as a template and an iterative saturation mutation strategy was adopted to modify key amino acids to attain efficient PAE-degrading esterase substitutes with a reasonable structure constructed by homology modeling method. Present study designed a total of 285 unit-site and multi-site substitutions of PAE-degrading esterase using the homology modeling method. Among them, 207 PAE-degrading esterase substitutions, which contained the 6-site PAE-degrading esterase substitute 1C7I-6-9 with 84.21% enhancement intensity of degradation ability revealed better degradability to all the 6 PAEs after modification. Moreover, molecular dynamics simulation based on the Taguchi method reported the optimal external application environment for PAE-degrading esterase substitutes as follows:pH=6, T=35℃, the rhamnolipid concentration was 50 mg/L, the molar ratio of nitrogen to phosphorus(N:P) was 10:1, the concentration of H₂O₂ was 50 mg/L, and the voltage gradient was 1.5 V/cm. The degradation ability of PAE-degrading esterase substitutes was found to be elevated by 13.04% as compared to that of the blank control under the optimal condition. Moreover, 11 highly efficient PAE-degrading esterase substitutes with thermal stability were designed.