促进职业核心素养培养的中职机电专业电类有效课堂教学模式研究

从中职机电专业电类有效课堂的学生现况以及特点对中职机电专业电类课堂有效教学的方式进行探讨。随着社会的迅速发展,机电是中职学业水平测试的基础课程。此门课程的种类范围较广,而且机电科目的理论知识偏艰深晦涩,对于学生群体而言,具有一定的挑战性,而当前中职学校也想抢占机电教学的制高点,因为全国范围内,对于机电课堂教学质量日趋重视,本文从机电教学改革的重要性着手,进一步分析机电教学的基本原则,最后得出在中职机电课堂教学方法的策略。当前的教育教学的改革在如火如荼的展开,可见教育教学的改革的脚步从未停止过,随着国家新课程改革的不断深入,教育改革的各项举措在各门学科中的实践教学过程中的应用效果甚好,中职机电教学作为新课程改革的重点科目,对于机电教学的课程改革的目的在于使得学生明确机电课程的基本框架,重点研究核心素养下如何提高中职机电课堂教学的效率。     

考虑径向位移时柔性桩荷载传递机理研究

基于李海芳竖向位移模式,考虑桩体径向位移,根据轴对称弹性理论,分析柔性桩的荷载传递。根据桩侧摩阻力条件,导出有效桩长的计算式,进而获得桩身应力、桩侧摩阻力的计算式。通过对比分析,验证计算式的合理性,并对相关参数的影响进行了分析。     

业主项目工程造价控制

随着我国国民经济的飞速发展,贷款修路,收费还贷的工程项目逐渐增多,工程造价的多少直接关系到还贷年限的长短,这一问题已经越来越显出其重要性。如何采取主动控制的手段合理确定和有效控制工程造价已成为工程管理的首要问题。文中从项目前期、招标阶段、施工阶段等过程对工程造价控制进行了论述。     

Multi-objective optimization study on dimensions of medium-sized cruise ship in concept phase北大核心CSCD

［Objective］Aiming at the problem of too many influencing factors and too little reference data for determining the dimensions of medium-sized cruise ships in the concept phase, a simplified multi-objective optimization method based on the fitting of dimensions and performance is proposed. ［Method］First, the dimension relations of medium-sized cruise ships are analyzed and the influence of the latest SOLAS requirements used to determine the optimization range. Second, the influence of cruise ship dimensions on space, resistance, stability and seakeeping are analyzed. Next, based on the principles of genetic algorithms, a multiobjective optimization algorithm with high robustness and high engineering adaptability is determined to establish a multi-objective optimization model for the concept design of medium-sized cruise ships. Finally, the Pareto solution obtained by multi-objective optimization is analyzed to provide initial references for determining the dimensions of the target cruise ship. ［Results］Implemented via a genetic algorithm, the optimization program proposed herein is applied in the concept design of a medium-sized cruise ship in order to optimize the initial dimensions, thereby achieving the expected outcome of providing reasonable initial dimensions for cruise ship design. ［Conclusion ］ The proposed simplified multi-objective optimization model can provide feasible initial dimensions for medium-sized cruise ships in the concept phase. As the Pareto solution obtained by multi-objective optimization has different focuses such as resistance and stability, the most suitable solution needs to be selected according to the design object. © 2023 Chinese Journal of Ship Research. All rights reserved.     

桥梁单锥孔夹片式预应力锚具握裹力分析

反拉法以测试曲线的拐点来判断锚下有效预应力，是当前最为广泛的锚下有效预应力检测手段。近年，众多学者发现测试曲线拐点处存在荷载骤降的情况。因此，针对反拉法测试曲线的突变段成因进行了探讨，提出了反拉荷载在夹片拉脱过程中需克服锚具握裹力从而导致突变段产生的观点。其中，锚具握裹力主要由锚圈与夹片的摩阻力和锚圈与夹片的机械咬合力构成。同时，为了得到握裹力的影响因素，建立了单锥孔夹片式锚具握裹力分析的有限元模型，设计并阐述了有限元模型的握裹力提取方法。通过有限元模型得到了影响锚具握裹力的3项影响因素——控制张拉力、摩擦系数、锥孔数量，并拟合了控制张拉力、摩擦系数与握裹力的关系曲线，得出了控制张拉力、摩擦系数与握裹力正相关的结论。     

低强高压旋喷桩复合地基承载的影响因素

基于高压旋喷桩复合地基有限元模型,研究低强高压旋喷桩正三角形布置和正四边形布置时,桩体弹性模量、桩长、土体内摩擦角对复合地基承载特性的影响,并分析高压旋喷桩的有效桩长。结果表明:正四边形布置时土体的最大竖向沉降量是正三角形布置时的93%,桩体最大竖向应力值是正三角形布置时的97%,采用正四边形布置要优于正三角形布置;随着高压旋喷桩弹性模量的减小,土体最大沉降量增大,桩体最大竖向应力减小;随着土内摩擦角的增大,土体最大沉降量减小,桩体最大竖向应力减小;当采用正三角形或正四边形布置时桩长超过10 m时桩体最大竖向应力基本不变,因此低强度高压旋喷桩有效桩长约为10 m,与文献计算结果和设计取值基本一致。