通过风能科学与工程课程传统教学和PBL教学模式进行对比,讨论了PBL教学模式及主动学习在课程教学中的效果.采用线下线上结合形式进行课程教学互动和考核.PBL及主动学习模式促进了学生自主学习意识,培养了社会性能力,锻炼了高层次思维.

加强实验技术人才的建设是高校实验室建设和发展的基础,也是决定实验室对高校贡献作用的重要因素.当前,高校对于实验技术人才的建设和管理不够重视,实验技术人员整体水平不高、工作积极性不高,对高校发展贡献不够显著,这又导致相关人员对实验技术人员不重视,长期以来形成恶性循环.因此,需要完善现有实验技术人才的招聘、培训、工作、评价、晋升等方面的机制,积极推动实验技术人才的建设,让实验室对高校的发展发挥应有的作用.

提出一种利用微生物诱导碳酸钙沉淀(MICP)技术的胶结尾砂方法,利用兼性厌氧菌在密封养护条件下胶结尾砂,解决利用好氧菌无法在缺氧或无氧环境下使用的问题.采用控制变量法对利用兼性厌氧菌MICP技术胶结尾砂试验的影响因素进行探究,研究了菌液浓度、胶结溶液浓度、尾砂粒径和养护温度对胶结效果的影响.结果表明:当菌液的OD600为1、胶结溶液中醋酸根离子浓度为0.6 mol/L、尾砂为多种不同粒径的尾砂混合体、养护温度为30℃时,胶结效果最佳;兼性厌氧菌的MICP技术具有胶结尾砂的潜力,为替代水泥作为尾砂胶结材料提供了有效途径.

高比例的可再生能源并网给电力系统运行带来了巨大挑战,灵活调节工业负荷是解决这一问题的有效手段之一.钢包精炼炉(LF)用电量大且生产节奏灵活,是一种重要的灵活性调节资源.然而,LF负荷灵活性的大小及其影响因素尚不清晰.因此,本研究中综合考虑LF与上下游设备(转炉和连铸机)之间的相关性,提出了 LF作为可削减负荷的灵活性评估方法,采用最大可削减负荷量指标评价LF的灵活性水平,然后分析库存转炉钢水量等因素对LF灵活性的影响.

对不同年级学生同时进行了冶金概论课程PBL教学改革实践.讨论了学生已有知识经验和教学背景对课程PBL教学中项目完成效果的影响,为不同年级全面开展PBL教学提供支持和经验积累.实践表明,已有知识经验和教学背景对项目的选题影响最大,但在学生能力和高层思维培养上没有差别,PBL的教学模式可以适应各年级知识体系,同时在不同年级开展教学活动.

随着岩石力学教学不断发展进步,应用真三轴实验设备进行教学具有局限性,该文建立了虚拟仿真实验教学平台,并利用该平台进行真三轴实验教学,达到了良好的教学效果.该虚拟仿真实验由教师提供实验技术要求,搭建可视化虚拟仿真用户界面,使学生深刻理解硬岩真三轴加载系统的性能参数、岩石试件真三轴应力-应变曲线测试过程以及声发射微观监测技术在岩石力学真三轴实验中的应用.学生可以通过虚拟平台便捷、直观地完成真三轴实验操作,有效解决实验设备不足、实验操作不安全等问题,有利于学生将理论学习与实践操作结合,提高学生对岩石力学专业知识的理解,对培养岩土领域人才具有重要促进作用.

为研究预制非贯通结构面试件各向异性及试件破坏声发射信号变化规律,对含不同倾角结构面试件进行单轴声发射实验.结果表明:完整试件比含预制结构面试件强度高,单轴抗压强度随结构面角度增加呈U型变化分布,斜45°结构面试件抗压强度达到最低值;在相同应力下,α小于45°结构面试件 φ1比α大于45°结构面试件轴向应变变化大,而α小于45°结构面试件φ2比α大于45°结构面试件环向应变变化小;破坏形态分析,当0°≤α<45°时,试件破坏面沿着轴向加载方向脆性破坏;当45°≤α≤60°时,试件破坏面垂直结构面方向形成脆性剪切破坏,并且试件也沿着结构面破坏,两个破坏面形成交叉模式;当60°

"新工科"和"金课"理念的提出,为中国教育探索提供了发展方向,也为新兴交叉学科背景下的新能源相关课程建设提供了指导,新能源产业的发展对新能源人才的培养方法和过程提出了新的要求.培养符合社会需求的工程人才,必须从课程结构、教学方法和评价机制等方面入手,有针对性地开展"新工科"理念下的"金课"建设.

Blast furnace gas (BFG) is a byproduct gas and a significant energy source in integrated steelworks. Precise BFG generation prediction plays a pivotal role in site energy scheduling and management. However, it is difficult to accurately predict fluctuations in BFG generation due to the variable operational statuses and complex chemical reactions that occur inside the blast furnace, hindering efficient energy utilization and accordingly causing BFG to flare and contribute to environmental pollution. To tackle this problem, a hybrid event-, mechanism- and data-driven prediction method is proposed in this work. In this novel approach, blast furnace operational events are considered when predicting BFG generation, thus making predictions more accurate by integrating a priori mechanism knowledge associated with the blast furnace ironmaking process; additionally, this approach ensures high accuracy by selecting the best available data-driven prediction model for different event-associated periods. To demonstrate the predictive performance of the proposed hybrid method, comparative experiments are conducted using practical data from integrated steelworks. The results highlight the excellent performance and accuracy of the proposed method when compared with the results of widely used moving average and artificial neural network models.

对辉长岩进行单轴直接加载和单轴循环加、卸载实验研究.分析辉长岩试样在不同方案下的循环加、卸载实验结果,与单轴直接加载进行抗压强度、弹性模量、峰后残余强度、应力-应变曲线等参数进行比较分析.实验结果对煤岩体动力学灾害的预测具有重要参考价值.

In order to study situation that the rock mass is keeping loading or at loading stage before the rock burst oc-curs,the rock mass with prominent tendency is often in the state of loading creep. Uniaxial loading experiment of the granite specimens with a gradient of each 30 kN was carried out under different holding time of 1 min,3 min,5 min,10 min and 15 min,combining with experimental studies on acoustic emission. Research results showed that:(1)Different holding time on the strength and acoustic emission parameters have a great difference. Compared with uniaxial loading directly,the strength of the test specimen at 15 min is reduced by 43%;Compared with the failure point of uniaxial loading-directly specimen,the acoustic emission hit rate of specimen at holding 15 min is increased by 47%, and the energy accumulation at holding 15 min is in-creased by 53%;(2)In different holding time,and with the same loading gradient increasing,the longer the holding time,the higher the AE hit rate of specimens;(3)In the experimental process of granite specimen,there will the phenomenon of speci-men damage at loading or just after loading,so it indicates that loading is a great impact on specimen damage;(4)Under differ-ent uniaxial loading compression conditions,the acoustic emission of granite in each stage has different characteristics. There-fore,the granite loading experiment can be used to study the microscopic damage and failure of rock,and also to predict the macroscopic fracture process of rock mass.

During the pilot works,in which the education department of Liaoning province want to advance the share of educational resource,and develop college students' learning on line and obtaining credit cross universities,we used "college physics" high-quality resource sharing curriculum of northeastern university as the optional course on line for Dongbei university of finance and economics.After two years of practice and exploration,we have accumulated a large number of teaching methods and management experience.In this paper,aside from the introduction of method and experience about the online optional course cross universities,we analyses the characteristics of this new teaching mode,advantages and challenges.The optional course cross universities can not only effectively use the high-quality resource sharing curriculum,but also promote the reform of teaching mode,methods and management system.It will be developed as an important teaching mode.

辽宁省教育厅鼓励区域内高校联合开设优质课程并推进师资、课程的共享与学分互认,为学生提供更为广阔的学习空间,满足学生个性化学习需要,并提高高等学校教育教学质量.在这种背景下,辽宁省首批跨校修读学分项目开始启动.本文以东北大学和东北财经大学合作项目大学物理课程的实践为例,探讨具体的实施背景、实施方案和实施效果并总结经验.跨校修读学分在多方面的不懈努力下,可以更好地实现精品资源公开课程的跨校共享,全面提升课程建设水平和教学质量,深化高等教育人才培养模式改革.

Electroslag remelting process can improve the quality of the ingot for special usage.Complex physical phenomena are involved in this process and the influence of the magnetic fluid flow,the heat and mass transfer,as well as the electrochemistry must be taken into account.By coupling the electromagnetic field,the flow field and the temperature field,a three-dimensional transient-state mathematical model has been developed to analyze the influence of melting rate on electroslag remelting process.The simulation results show that,with the increase of melting rate,the current density,joule heat and electromagnetic force become bigger,and the maximum value of field increases more than 100% when melting rate increases from 14.4 kg/h to 27.0 kg/h.With the increase of melting rate,the maximum value of temperature increases a little,while the maximum value of velocity increases about 50%,and the depth of metal melting pool increases from 27 mm to 38 mm,which is harmful to the ingot quality.

换热器是循环冷却水系统中的重要设备之一，其合理设计、制造、选型和运行对整个系统而言都具有非常重要的意义。文章在分析了流动阻力情况的基础上，计算了多种换热器的水头损失情况，并着重推导了在循环水系统中被广泛使用的板式换热器的水头损失模型，本模型具有参数易得、适用性强等优点。

A mathematical model has been developed to understand the electromagnetic phenomena, heat transfer and molten steel flow in a continuous casting tundish with channel-type induction heating. Maxwell equations are first solved using the finite element method to determine the electromagnetic force and joule heating. Then, the Navier-Stokes equations and energy conservation equation are also solved with the electromagnetic force and joule heating as a source term, respectively. The two-equation BNG k-epsilon model is used to represent the turbulent mixing. Additionally, the tracer distribution is determined by solving a scale transport equation. The coupled flow field, temperature distribution and concentration distribution are solved by the finite volume method. A non-isothermal water model experiment is performed to observe significantly buoyancy driven flow in the tundish with induction heating. The results indicate that a current loop would be formed by the induced current through the two channels. The electromagnetic force points to the center of the channel generating a pinch effect on molten steel. As skin effect and proximity effect, the electromagnetic force as well as the joule heating in the region closer to the induction coil is greater than that in another region. Therefore, spiral recirculation would occur in the channels when molten steel flows through. After flows through the channels, the molten steel lifts upward under the effect of buoyancy. The heat loss of molten steel can be compensated effectively by the joule heating, and the temperature distribution become more uniform in the continuous casting tundish with induction heating.

针对某钢厂双通道式感应加热中间包,建立了三维非稳态数学模型来研究感应加热中间包内夹杂物的运动行为和去除率.从力平衡原理出发,采用欧拉-拉格朗日方法分析了感应加热中间包内夹杂物的运动行为.建立了感应加热情况下夹杂物碰撞长大的数学模型,考察了夹杂物碰撞长大对其去除率的影响.结果表明,钢液流过通道受到紧箍作用,夹杂物会受电磁压力作用而向通道壁面运动,有利于夹杂物的去除;碰撞长大能够显著提高小粒径夹杂物的去除率;感应加热有助于夹杂物的去除,尤其是小粒径夹杂物.

A novel resonant DC link soft-switching inverter was proposed to improve the efficiency and performance of inverter. Auxiliary resonant unit was added to DC link of conventional inverter to make DC-bus voltage decrease to zero periodically, which realized zero-voltage and zero-current operation of all switching devices in inverter and reduced switching losses and reverse recovery losses of diodes. Furthermore, switching devices in the auxiliary resonant unit worked on and off under zero current switching. In addition, the control is simple and less dependant on load current, and the time of transition is freely selected. The equivalent circuits at different operation modes, the analysis of the circuit and parameter design method were presented. A 10 kW laboratory prototype has been built. Experimental results were proposed to confirm validity of soft-switching inverter presented.

案例教学是提高课堂教学效果的一个有效途径。在阐述案例教学的含义及市政管理课程采用案例教学的必要性的基础上,运用SWOT方法,分析了市政管理课程案例教学面临的优势、劣势、机会以及威胁,提出了完善市政管理课程案例教学的相应举措。

A novel zero-voltage and zero-current resonant pole soft-switching inverter was proposed to achieve zero- voltage and zero-current switching simultaneously when main power devices turn-on and turn-off. Therefore, turn-on capacitive losses could be reduced for devices which the intrinsic capacitor value cannot be neglected. Additionally losses caused by the tail current can also be reduced, when IGBTs are used as main switches. The commutations of the main power devices occur truly without losses. Furthermore, reverse recovery losses of main diodes are minimized, and auxiliary switches commutate at zero current. The equivalent circuits at different operation modes ,the analysis of the circuit and parameter design method were presented. A 1 kW laboratory prototype had been built. Experimental results were proposed to confirm validity of soft-switching inverter presented.