隧洞开挖典型掏槽设计方法

针对目前隧洞开挖爆破施工中缺少具体、详细的掏槽设计方法的现状,提出了最常用的2种典型掏槽方式,并详细论述了其设计方法。这些掏槽方式及设计方法均在实际施工中得到了推广应用,并且取得了良好的爆破效果。实际应用表明:这些典型掏槽方式及设计方法能有效提高硬质岩石开挖的钻孔利用率,能将钻孔利用率提高到98%～100%,实现掌子面基本无残孔,从而有效提高单循环进尺,加快开挖进度,降低开挖成本。     

Dual-fuel diesel engine run with injected pilot biodiesel-diesel fuel blend with inducted oxy-hydrogen (HHO) gas

Oxy-hydrogen gas (HHO) is a carbon-free fuel, which is produced by the water electrolysis process. It can be used as an alternative to hydrogen since the current global hydrogen production and storage may not meet the required demand for transportation applications. This research work investigates the engine behavior of a compression ignition (CI) engine operated in dual-fuel mode by inducting HHO as a primary fuel and injecting two different pilot fuels viz., diesel, and JME20 (a blend composed of 80% diesel with 20% Jatropha methyl ester) at optimized engine conditions. The results revealed that; heat release rate, brake thermal efficiency, exhaust gas temperature, and nitric oxide emission are found to be higher about 5.2%, 1.1%, 18.6%, and 19.6% respectively, while unburnt hydrocarbon, carbon monoxide, and smoke emissions are reduced by about 33.3%, 29.4%, and 18.7% respectively in Opt.JME20 + HHO operation compared to that of the baseline data at maximum load.     

雷达工程专业本科毕业设计指导模式探索

为提高本科毕业设计指导工作效率和毕业论文质量，本文基于雷达工程专业特点建立了“导师主导--研究生辅助--本科生合作”的多层次、模块化、场景化指导模式。该模式以导师为核心、科研小组和学员合作为辅助，全方位全过程保障本科毕设工作。实践表明，该模式可以有效提高指导工作效率和本科毕业设计质量，学生专业素养和实践能力显著提升。本文对电子类专业本科毕设指导具有重要借鉴意义。     

"电磁场与电磁波"课程混合教学模式研究

“电磁场与电磁波”是多种学科的交叉点，是电子信息、通信技术相关专业的重要理论基础，是电类专业的一门核心基础课程。该课程内容涉及面广、理论抽象、数学分析多，是公认的一门教师难教、学生难学的课程。本文针对“电磁场与电磁波”课程教学实际，尝试利用前沿技术引领课堂教学，对教学模式进行改革与实践。以课程为中心、教师为主导、学生为主体，探索覆盖体系课程融合、课外仿真实践、课程思政、工程案例与科研融入、翻转课堂、线上线下并行等混合教学模式。通过教学模式改革，希望打通课前、课中、课后以及相关课程间的连接通道，帮助学生系统理解和消化电磁场与电磁波的基本理论，充分锻炼学生独立解决实际问题和实践创新的能力。     

石化企业地下污水管道防渗设计

根据近几年来国家对地下水资源污染防控要求,新建石油化工项目、已建成装置可能产生渗漏、泄漏污染的地下污水管道均需采取防渗措施。为了保护地下水资源,结合工程经验,简单介绍了工程设计中常选择的几种地下污水管道防渗方式,防渗膜、防渗管沟及防渗套管。并叙述了这几种防渗方式的适用条件、优缺点,以及管道发生渗漏后能及时被发现的措施。     

Shear and mode II fracture of PUR foams

Polyurethane (PUR) foam materials are widely used as cores in sandwich composites, for packing and cushioning. They are made of interconnected networks of solid struts and cell walls incorporating voids with entrapped gas. The main characteristics of foams are lightweight, high porosity, high crushability, and good energy absorption capacity. Fracture toughness in mixed mode loading is of particular interest because foam cracking weakens the structure’s capacity for carrying loads.Present paper assesses the shear elastic (shear modulus) and mechanical (shear strength) properties of polyurethane foams. Also, three different types of specimens were used to determine mode I and mode II fracture toughness. The shear modulus, shear strength and fracture toughness increases with increasing foam density. Also the effect of loading direction and loading speed is investigated. The authors propose a micromechanical model to estimate fracture toughness based on the tensile strength of the solid material and the topology of the cellular structure.     

Crankshaft failure analysis of a boxer diesel motor

This paper reports a failure mode analysis of a boxer diesel engine crankshaft. Crankshafts are components which experiment severe and complex dynamic loadings due to rotating bending combined with torsion on main journals and alternating bending on crankpins. High level stresses appear on critical areas like web fillets, as well as the effect of centrifugal forces and vibrations. Since the fatigue fracture near the crankpin-web fillet regions is one of the primary failure mechanisms of automotive crankshafts, designers and researchers have done the best for improving its fatigue strength. The present failure has occurred at approximately 2000 manufactured engines, and after about 95,000 km in service. The aim of this work is to investigate the damage root cause and understand the mechanism which led to the catastrophic failure. Recommendations for improving the engine design are also presented.     

基于UAS模式的馆际互借与文献传递系统认证方式初探

本文通过分析高校数字图书馆馆际互借与文献传递系统用户身份认证方式的发展过程,重点阐述基于CALIS馆际互借系统的UAS联合认证方式.共享了本校图书馆使用UAS联合认证方式的一些体会.     

基于CDIO工程教育理念的化学工程与工艺专业培养模式研究与探索

我们针对现阶段国内工科院校教育现状,借助国际先进的CDIO工程教育模式,对合肥工业大学化学工程与工艺专业的教学体系、教学内容、教学方法及学生的考核制度等进行了改革。教改注重课程理论与实践环节的连接,引导学生主动探索,全面培养学生的CDIO工程能力,以培养合格的化学工程与工艺专业人才为目标。     

基于“卓越计划”的应用型人才培养模式改革——以化学工程与工艺专业为例

"卓越计划"是教育部贯彻教育规划纲要精神启动的一项重大改革计划,以培养创新能力强、适应经济社会发展需要的高质量各类型工程技术人才为目标。本文以教育部试点专业为基础,按照化工卓越工程师培养的目标要求,建立以培养学生工程实践能力为目标的培养方案,以工程教育理念为核心,课程优化整合、教学改革为重点,采取走出去、请进来等多种形式实施"卓越计划",取得了显著效果。