常微分方程课程思政与教学实践

在我国高等教育改革和思想政治建设相关政策的指引下,结合数学专业学科特点进行课程思政建设。以“常微分方程”课程为例深入挖掘各章节蕴含的思政教育元素,并以“变量分离方程”作为思政案例展开教学,将思政元素和教学内容有机融合,实现专业课与思政教育同向同行,形成协同效应。从知识和能力、价值观认同、行为外化三个方面对课程思政实践效果进行评价,取得良好效果,达到了立德树人教育目的。     

强威粉在天然橡胶汽车减震衬套胶料中的应用研究

研究强威粉在天然橡胶(NR)汽车减震衬套胶料中的应用。结果表明:强威粉属于纳米填料,与普通无机填料相比,强威粉对丁苯橡胶(SBR)基本配方胶料的补强性能较好,强威粉增量替代炭黑N770用于NR汽车减震衬套胶料中,胶料具有优异的强度性能、绝缘性能和减震性能,且原材料成本较低。强威粉适合用作减震和绝缘橡胶制品的填料。     

Preparation of surface‐modified,micrometer‐sized carboxymethyl chitosan drug‐loaded microspheres

Drug‐loaded microspheres have attracted much attention in embolization therapy for liver cancer in recent years. Carboxymethyl chitosan has obvious advantages for biomedical applications because of its exceptional biocompatibility and biodegradability. In this study, surface‐modified carboxymethyl chitosan microspheres were prepared by the crosslinking reactions of carboxymethyl chitosan in a reverse suspension system with poly(ethylene glycol diglycidyl ether) (PEGDE) as the crosslinking agent; this was followed by the grafting polymerization of 2‐acrylamido‐2‐methyl propane sulfonic acid on the surface of the microspheres. The microspheres showed regular spherical shapes with size distributions ranging from 300 to 600 μm. Ion‐exchange groups (? COOH, ? SO₃H) were introduced into the microspheres; these groups could load doxorubicin with a loading rate as high as 34.6% in 24 h. This was an increase of 49.8% compared to that of the pure carboxymethyl chitosan microspheres. Additionally, the microspheres possessed large network structures because macromolecular PEGDE was used as the crosslinking agent. The drug‐release profile showed that the surface‐modified microspheres displayed a sustained‐release manner compared with the nonmodified microspheres in phosphate‐buffered saline. These microspheres have promising applications as drug‐loaded arterial embolization agents for the interventional treatment of tumors. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45731.     

无机盐阴阳离子对稠油水包油型乳状液稳定性的影响

考察了两性/非离子复配表面活性剂浓度、无机/有机复配碱浓度、不同价态正负离子对稠油水包油型乳状液稳定性的影响规律。实验结果表明:随着复配表面活性剂浓度的增加,乳状液的分水率先急剧降低后缓慢下降;复配碱对乳状液的稳定性存在最优浓度;无机盐对乳状液的稳定性具有双重作用,低浓度盐提高乳状液的稳定性,高浓度盐降低乳状液的稳定性;一价阳离子对乳状液的稳定性影响顺序为KCl> NaCl> LiCl;二价阳离子对乳状液稳定性的影响程度为MgCl₂> CaCl₂;一价阴离子对分水率的影响顺序为NaCl> NaBr> NaI;高价阴离子对乳状液稳定性的影响程度为Na₂SO₄> NaCl> Na₃PO₄。     

聚电解质复合物研究现状及应用前景

介绍了聚电解质复全物的制务及研究方法，对影响聚电解质复合物形成及其结构的结果进行了阐述，简要介绍了其性能并对应用前景作了展望。     

Head‐to‐Head Prenyl Synthases in Pathogenic Bacteria

Many organisms contain head‐to‐head isoprenoid synthases; we investigated three such types of enzymes from the pathogens Neisseria meningitidis, Neisseria gonorrhoeae, and Enterococcus hirae. The E. hirae enzyme was found to produce dehydrosqualene, and we solved an inhibitor‐bound structure that revealed a fold similar to that of CrtM from Staphylococcus aureus. In contrast, the homologous proteins from Neisseria spp. carried out only the first half of the reaction, yielding presqualene diphosphate (PSPP). Based on product analyses, bioinformatics, and mutagenesis, we concluded that the Neisseria proteins were HpnDs (PSPP synthases). The differences in chemical reactivity to CrtM were due, at least in part, to the presence of a PSPP‐stabilizing arginine in the HpnDs, decreasing the rate of dehydrosqualene biosynthesis. These results show that not only S. aureus but also other bacterial pathogens contain head‐to‐head prenyl synthases, although their biological functions remain to be elucidated.     

分子筛催化剂组成对烃类转化的催化作用

综述了沸石分子筛催化剂的组成中主催化活性组分、负载金属改性对于烃类转化规律的影响。不同催化剂的活性组分有别,硅铝比和骨架孔道的不同其催化作用也不同;催化剂的金属改性种类和负载量很大程度上改变了催化剂的催化活性和选择性,对于烃类转化影响很大。由此总结分子筛催化剂的开发在于骨架结构、负载改性类型及负载量。     

Effect of pulverized coal/carbon black hybrid fillers on mechanical properties and thermal stability of styrene butadiene rubber composites

Pulverized coal (coal) possesses a layered structure similar to graphite and is a potential reinforcing filler. In this paper, ball milling is used to reduce the particle diameter of coal. The coal is modified with KH-560 to obtain K-COAL and prepared K-COAL/styrene-butadiene rubber (SBR) composites. In addition, carbon black (CB) is modified to obtain CB-Si69, K-COAL and CB-Si69 are added to SBR in different ratios to prepare COAL/CB/SBR composites. The results show that the addition of K-COAL can improve the vulcanization performance, thermal stability, and mechanical properties of SBR composites, but the reinforcing effect is weak. In the COAL/CB/SBR composites, the vulcanization and mechanical properties of the composites gradually increase with the increase of CB, while those of the thermal stability decrease. The tensile strength of the 10 phr COAL/30 phr CB/SBR composite is 24.1 MPa, which is elevated by 1105% and 205% compared with the pure SBR and 40 phr K-COAL/SBR composites, respectively. The composites maintain high elasticity while the tensile strengths are greatly improved, and the mechanical properties are significantly enhanced. In conclusion, this paper provides a reference for the clean utilization of coal and shows new possibilities for finding new fillers to replace CB.     

高导电聚苯胺/多壁碳纳米管复合材料的制备与电性能研究

采用混酸处理法对多壁碳纳米管（MWCNTs）进行表面处理, 通过原位聚合法,以过硫酸铵为氧化剂,制备高导电聚苯胺(PANI)/MWCNTs复合材料。采用透射电子显微镜、傅里叶变换红外光谱仪 、紫外可见分光光度计以及X射线衍射仪对MWCNTs和复合材料进行表面观察、结构测定与性能表征;使用两探针法测量复合材料的电性能,并通过平均电场理论和逾渗阈理论进行理论分析。结果表明,MWCNTs的直径约为60~100 nm,长度约为几十微米,酸化后MWCNTs表面引入大量—OH和—COOH;随着MWCNTs含量增加,导电PAM/MWCNTs复合材料的电导率增加,渗滤阈值的理论值为2.36 %。     

一种新型乳化剂在丙烯酸酯乳液聚合中的应用研究

以新型环保型APG 0810(烷基葡萄糖苷)乳化剂作为传统有毒APEO(烷基酚聚氧乙烯醚)乳化剂的替代品,采用预乳化-种子乳液聚合法制备了纯丙烯酸酯聚合物乳液。考察了APG 0810含量和聚合温度对预乳液稳定性、乳液黏度和冻融稳定性、胶膜表面性能和力学性能等影响。结果表明:当w(APG0810)=0.8%～1.5%(相对于乳液总质量而言)时,预乳液的储存稳定时间超过240 min;当w(APG 0810)=1.0%、聚合温度为88℃时,乳液黏度和冻融稳定性明显提高,胶膜综合性能相对最好。