保健路隧道工程浅埋暗挖施工技术研究

哈尔滨市保健路隧道工程受力复杂,施工难度大,介绍了城市双洞连拱浅埋隧道工程特点和风险分析,浅埋暗挖法施工原则、主要施工方法和技术措施.     

Corrosion risk assessment of chloride-contaminated concrete structures using embeddable multi-cell sensor system

Monitoring the service condition of concrete structures requires the quantitative assessment of properties and corrosion rate of structural steels surrounded by concrete. A multi-cell sensor system that included a reference electrode, a chloride content sensor, a macrocell current unit and an electrical resistance measurement unit was developed. This system provided the following important electrochemical data in the cover-zone concrete on site: open circuit potential, macrocell current from anodes to cathode, chloride profile, concrete resistance and corrosion rate of built-in anodes. The experimental results show that the macrocell current increases when the chloride content in concrete is higher. Thus, monitoring the chloride content is a good method for monitoring the corrosion state. The chloride ion content and cover depth are the key factors that affect the electrical resistance of concrete. Without considering the temperature and time, a simplified model of the instantaneous corrosion rate of steel rebar in a concrete structure based on the measured chloride contents and concrete resistance was proposed. The test results further prove the reliability of this simplified predicting model.     

基于混沌时间序列的神经网络对瓦斯涌出量预测

瓦斯灾害是煤矿中最严重的灾害之一,瓦斯治理是我国煤矿安全的主攻方向。瓦斯涌出量的预测对遏制矿山瓦斯灾害、保证矿山安全和矿山技术经济指标都有重要意义。传统的方法预测精度不高,而神经网络在构建网络模型时具有一定的主观性。将混沌时间序列理论引入瓦斯预测中,为构建神经网络模型提供理论依据。通过实例证明在实际应用中是可行的。     

Preparation of Ti/MnO₂ Reference Electrode and Its Application in Concrete Structures

A novel Ti/MnO2 reference electrode (TMRE) used for concrete environment was fabricated by the electro-deposition method and encapsulated carefully.The properties of the electrode were characterized by open-circuit potential,potentiodynamic polarization behavior in synthetic concrete pore solutions and electrochemical performance in cement mortar.The experimental results indicate that the TMRE shows good stability with and without the addition of Cl-ions and desirable polarization behavior in synthetic pore solution.Results of tests in cement mortar indicate that the potential of TMRE will be stable after about 7 days.The stability and desirable polarization behavior make it a promising reference electrode for concrete environment.     

综放开采工作面的安全管理浅析

以山东某大型煤矿为工程背景,针对复杂难采条件下的综采放顶煤工作面,简要说明如何应用有效的安全管理手段,加强对水、火、瓦斯和冲击矿压等煤矿灾害的防治,实现煤矿的安全高效生产。     

2-氨基苯并咪唑缩对甲基苯甲醛席夫碱的合成及缓蚀性能

采用静态失重、极化曲线、交流阻抗(EIS)方法测试席夫碱自组装膜在3.5％(质量分数)NaCl溶液中对铜的缓蚀作用,考察了浓度和时间两个因素.结果表明,当浓度为15 mmol/L,组装时间为14 h时,合成的缓蚀剂缓蚀性能较好,缓蚀率可达99.89％.表面形貌分析结果表明,席夫碱化合物在铜表面形成簇状物质.拉曼光谱分析结果表明,席夫碱通过咪唑环和C=N键垂直吸附于金属表面.光学接触角测量结果表明,缓蚀剂表面不易被浸润,疏水性较好.     

以职业标准为导向的高职建筑信息化管理人才培养研究

文章以职业标准与高职建筑信息化管理人才结合的必要性作为切入点,阐述在以职业标准为导向的人才培养中所存在的问题,提出构建以职业标准为导向建筑信息化管理人才的具体对策。     

外加剂对砂浆收缩性能的影响

本文探讨了影响混凝土中水泥砂浆收缩的主要因素,并对其收缩机理进行了初步分析和探讨。结果表明,FDN减水剂能显著增大水泥砂浆的收缩;粉煤灰的掺入能降低水泥砂浆的收缩。试验结果说明,外加剂的颗粒分散效应和矿粉的水化活性是影响水泥砂浆收缩的主要因素。     

外加电压对线性极化方法测量钢筋锈蚀的影响

在3 V外加电压的作用下,进行混凝土中氯离子导致的钢筋锈蚀的加速试验,通过线性极化法研究钢筋的锈蚀过程。结果表明:由于外加电位以及氯离子渗透的共同作用,导致钢筋的开路电位先升高后降低,其中,外加电位导致钢筋电位正移,而当到达钢筋表面的氯离子达到一定浓度时,腐蚀电位开始负移,极化电阻变小。最终钢筋钝化膜完全破坏时,钢筋表面的氯离子浓度为占水泥石质量的0.285%。     

两种邻苯二胺类席夫碱缓蚀剂缓蚀性能研究

运用分子自组装技术在铜电极表面分别制备了双水杨醛缩邻苯二胺（简称A）和双邻香兰素缩邻苯二胺（简称B）两种席夫碱缓蚀膜。采用电化学方法研究了两种席夫碱自组装单分子层膜在质量分数3.5%的NaCl溶液中对铜的缓蚀行为。在25 ℃下,席夫碱A溶液浓度为10 mmol/L,组装时间为4 h时缓蚀效果最佳,席夫碱B溶液浓度为15 mmol/L,组装时间为6 h时缓蚀效果最佳,A、B的缓蚀效率分别达到94.06%和96.62%。结果表明,两种缓蚀剂对铜具有很好的缓蚀性能,且缓蚀效果B>A。