油酸修饰纳米CaCO3对PP结晶行为和力学性能的影响

Oleic acid (OA)-modified CaCO3 nanoparticles were prepared using surface modification method. Infrared spectroscopy (IR) was used to investigate the structure of the modified CaCO3 nanoparticles, and the result showed that OA attached to the surface of CaCO3 nanoparticles with the ionic bond. Effect of OA concentration on the dispersion stability of CaCO3 in heptane was also studied, and the result indicated that modified CaCO3 nanoparticles dispersed in heptane more stably than unmodified ones. The optimal proportion of OA to CaCO3 was established. The effect of modified CaCO3 nanoparticles on crystallization behavior of polypropylene (PP) was studied by means of DSC. It was found that CaCO3 significantly increased the crystallization temperature, crystal-lization degree and crystallization rate of PP, and the addition of modified CaCO3 nanoparticles can lead to the for-mation of β-crystal PP. Effect of the modified CaCO3 content on mechanical properties of PP/CaCO3 nanocompo-sites was also studied. The results showed that the modified CaCO3 can effectively improve the mechanical proper-ties of PP. In comparison with PP, the impact strength of PP/CaCO3 nanocomposites increased by about 65% and the flexural strength increased by about 20%.     

建筑施工项目管理研究

加强建筑施工项目管理关系到建筑工程质量和安全头等大事。文章介绍了建筑施工项目管理的重要作用，分析了我国建筑施工项目管理中存在的问题，研究了加强建筑施工项目管理的主要内容。     

纳米狭缝中水流动非平衡分子动力学模拟

采用非平衡分子动力学模拟（non-equilibrium molecular dynamics simulation）方法研究了不同间距纳米狭缝之间水的流动行为。研究了纳米狭缝间距、壁面性质和外部压力对水流动速度径向分布、有效黏度、壁面速度和滑移长度的影响,讨论了Navier-Stoke（N-S）方程的适用性。研究结果表明,N-S方程仅适用于3 nm以上的孔道;狭缝尺寸的增加和施加压力的增加均会使得管内流速增加,而造成表观黏度降低以及滑移长度增加。壁面亲水性的增加仅使得滑移长度降低,表观黏度并没有发生较大变化。     

沸石咪唑骨架材料（ZIF-8）原位生长改性玄武岩鳞片/环氧防腐抗菌涂层的制备与性能

通过一锅法在硅烷偶联剂改性的玄武岩鳞片(MBS)表面原位生长沸石咪唑骨架材料(ZIF-8)得到MBS@ZIF-8新型复合填料，随后与环氧树脂(EP)复合构建了一种新型抗菌耐腐蚀环氧涂层(MBS@ZIF-8/EP)。通过扫描电子显微镜(SEM)、X射线衍射仪(XRD)和傅立叶变换红外光谱仪(FT-IR)对MBS@ZIF-8的形貌、成分进行表征，通过平板计数法探究了MBS@ZIF-8对大肠杆菌和金黄色葡萄球菌的抑菌性能，通过电化学阻抗谱(EIS)探究MBS@ZIF-8对环氧涂层耐腐蚀性的影响。结果表明：制备的MBS@ZIF-8复合填料表现出优异的抗菌性能，对大肠杆菌和金黄色葡萄球菌的抑菌效率均可达90%以上；同时MBS@ZIF-8能有效提高环氧涂层的耐腐蚀性和机械性能。其中，MBS@ZIF-8/EP涂层的|Z|_{0.01 Hz}相较于EP涂层提升了3个数量级，硬度为6H。在1 080 h的中性盐雾试验后，该涂层表面无明显腐蚀现象，表明MBS@ZIF-8/EP涂层具有优异的机械性能与防腐抗菌性能。     

柴油机EGR系统反馈控制参数研究

基于GT-Power软件建立了YC4E170-31型涡轮增压柴油机的仿真模型,并通过对比试验数据校核了仿真模型。在分析废气再循环(exhaust gas recirculation,EGR)对柴油机进气状态影响基础上,利用构建的仿真模型,研究了不同进气成分下热效应、稀释效应、化学效应对柴油机NOx排放的影响,对比分析了分别选择进气氧气质量分数和EGR率作为控制目标时,NOx排放随进气流量变化的趋势。结果表明:当进气流量一定时,氧气质量分数是影响NOx生成的主要参数,稀释效应对NOx排放的影响程度远高于热力及化学作用;瞬态工况下,选取EGR率作为EGR的控制参数是有局限性的,进气氧气质量分数与NOx排放的相关程度更高,更适合作为反映NOx排放生成的控制参数。     

油酸修饰纳米CaCO3对PP结晶行为和力学性能的影响

Oleic acid (OA)-modified CaCO3 nanoparticles were prepared using surface modification method. Infrared spectroscopy (IR) was used to investigate the structure of the modified CaCO3 nanoparticles, and the result showed that OA attached to the surface of CaCO3 nanoparticles with the ionic bond. Effect of OA concentration on the dispersion stability of CaCO3 in heptane was also studied, and the result indicated that modified CaCO3 nanoparticles dispersed in heptane more stably than unmodified ones. The optimal proportion of OA to CaCO3 was established. The effect of modified CaCO3 nanoparticles on crystallization behavior of polypropylene (PP) was studied by means of DSC. It was found that CaCO3 significantly increased the crystallization temperature, crystallization degree and crystallization rate of PP, and the addition of modified CaCO3 nanoparticles can lead to the formation of β-crystal PP. Effect of the modified CaCO3 content on mechanical properties of PP/CaCO3 nanocomposites was also studied. The results showed that the modified CaCO3 can effectively improve the mechanical properties of PP. In comparison with PP, the impact strength of PP/CaCO3 nanocomposites increased by about 65% and the flexural strength increased by about 20%.     

任意加密和变化角度的有限元剖分算法在电励磁双凸极电机上的应用

针对电动车用双凸极永磁电机运用有限元法进行计算时对各个点磁场的特殊要求,采用改进的三角网自动生成算法,使其能对各个区域的三角形的疏密和角度变化灵活的进行控制。通过剖分实例显示,该方法能生成高质量的网格,适应能力强,它已成功的应用于车用外转子双凸极永磁电机的有限元计算,并取得了良好的效果。     

大型发电机蒸发冷却技术

我国大型发电机蒸发冷却技术的研发已有40多年的历史,近年来实现了由实验室试验研究阶段向工业化、商品化应用的转变。论述了蒸发冷却技术的基本原理、特点、核心技术及应用前景。     

高职院校教育科研模式的探索

高职院校的教育科研模式的建立关系到教育目标的实现、教育效益的最大化、教育发展的核心竞争力及创新力的快速形成.依据高职教育自身的特点,建立富有高职特色的教育科研模式,为教育科研发展创造更多的价值,其不仅作为一种范式而存在,而且还会作为一种途径和渠道,作为方法与策略而存在。     

转型期资源型城市高职教育发展的定位

资源型城市转型,以各自的优势和特色,寻求不同的发展脉络,如从单一型经济向多元化及高科技型城市的转变等,已经成为现代城市发展的浪潮和城市发展的基本战略。资源型城市发展的转型突出地表现在城市发展经济着力点的变化、发展模式的变化、发展文化的变化。本文基于以大庆市为代表的转型期城市经济与文化发展中高职教育的建构探析,提出高职教育的定位思路,探讨高职教育成为推动资源型城市发展动力与活力的理论依据。