基于因子分析的创城满意度模型研究——以冬奥会背景下张家口市为例

在京张联合举办2022年冬奥会和科学建设文明城市的背景下,为了掌握影响张家口市创城的影响因素,准确预测出未来张家口文明城市建设情况,.建立了张家口创城满意度指标评价体系并设计发放调查问卷,对回收数据采用SPSS软件,建立因子分析模型,得到创城满意度影响因子,对张家口的县地区得分做出排名并评价,建立回归分析模型,从生活、生态、市场、法治和政务环境分析对创城满意度的影响,找到张家口市文明城市建设存在的主要问题,提出改善创城满意度建议,为冬奥会创造良好的城市环境。     

移动学习App在客观题备考中的应用研究

移动学习app是一种新兴的教育技术,客观题是标准化考试的一种主要形式。本文以参加高级职业资格证考试的本校学生为实验对象,通过云班课app设计测验、头脑风暴、投票问卷等40余项多元化备考活动,研究了移动学习app在客观题备考中的应用方法及应用效果。实践数据分析表明,移动学习app满足了学生不受时空限制的个性化学习的需求,提高学生学习客观题的积极性和学习效率,并大幅提高了学习成绩和考试合格率。     

Meta photonic crystal paper devices

Science China Technological Sciences -     

一种基于传感器数据综合处理算法

提出基于知识参量的数据标准化处理方法,介绍了知识参量的构成以及故障征兆的隶属度表示方法.根据功率相等的原则提出了传感器数据中的野值滤波方法.运用神经网络和最小二乘法加权的方法对缺损数据进行填充,并分别与最小二乘法和BP网络的处理结果进行比较.仿真结果表明,运用该方法进行数据处理,可以在保证数据完整准确的情况下,有效地弥补原始数据的缺陷,提高了数据的准确性和可信度.     

高速公路混凝土路面板底脱空化学灌浆治理方法

结合工程实例阐述了高速公路混凝土路面板底脱空成因,介绍了板底脱空的判定方法和化学灌浆治理施工工艺。     

空压机清理孔底沉渣在桩基础施工中的应用

介绍了利用空压机清理孔底沉渣方法在郑州国际会展中心钻孔灌注桩施工中的应用情况，并分析了这种清孔方法与正循环清孔、泵吸反循环清孔相比具有的优势。     

Biocompatible electrospun tactic poly(methyl methacrylate) blend fibers

Uniform and beads free fibers of pristine syndiotactic PMMA (s-PMMA), isotactic PMMA (i-PMMA), and their blends in the ratio of s:i = 3:1, 1:1 and 1:3 were successfully prepared using the electrospinning technique. The tactic PMMA blend fibers showed unique thermal stability and glass transition temperatures compared to their pristine counterparts. An interesting endotherm peak was observed for the s:i = 1:3 electrospun fibers, which might indicate a complex formation between the two tactic PMMAs. Systematic surface functionalities study by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) revealed the interactions between these two tactic PMMAs. Biocompatibility of tactic PMMA and their blend fibers was first time comparably investigated using HeLa as the model mammalian cell line; an intriguing observance was first revealed that the blend fibers showed better biocompatibility than both pristine ones, though the behind mechanism is not well understood yet.     

TiB2 Powders Synthesis by Borothermal Reduction in TiO2 Under Vacuum

TiB₂ powders were synthesized by borothermal reduction in nanoscale TiO₂ with boron under vacuum. Reaction processes were investigated, and the effect of by‐product B₂O₃ was evaluated. Results showed that TiO₂ was firstly reduced by boron to form TiBO₃ and Ti₂O₃, and then to produce TiB₂ and B₂O₃ with increasing temperature. The reaction processes of TiB₂ powders synthesis included two‐step reduction in TiO₂ by boron and the removal of B₂O₃. The presence of B₂O₃, which was previously reported as the most important factor in promoting the coarsening of ZrB₂ and HfB₂ powders by borothermal reduction, did not lead to significant coarsening of TiB₂ powders. Due to the minor effect of B₂O₃, TiB₂ powders with small particle size and low oxygen content could be prepared by direct heat treatment of TiO₂ and boron at 1550°C under vacuum for 1 h. The particle size and oxygen content of synthesized TiB₂ powders were ~0.9 μm and ~1.7 wt%, respectively.     

Sintering Behavior and Dielectric Properties of Ultra‐Low Temperature Fired Silver Molybdate Ceramics

Ag₂MoO₄ ceramic was prepared by using the solid‐state reaction method, which could be sintered at 450°C for 2 h, having a relative permittivity of 8.08, a Qf value of 17 000 GHz, and a temperature coefficient of resonance frequency about ?133 ppm/°C. Ag₂MoO₄ ceramic was chemically compatible with silver but reacted seriously with aluminum to form (Ag_0.5Al_0.5)MoO₄ during the sintering. The fitting of infrared spectra and the Shannon's additive rule were employed to study intrinsic dielectric behaviors of the ceramics at microwave region. Ionic displacive polarization and the electronic polarization contributed almost equally to the dielectric permittivity of the ceramic at microwave region. The Ag₂MoO₄ ceramics could be a good candidate for ultra‐low temperature co‐fired microwave devices.