21世纪高校外语教师专业发展影响因素及对策

21世纪以来,我国大学外语教学在教学理念、模式、方法以及手段上已经取得了显著进步,但仍然没有从根本上完全摆脱“长时低效”的尴尬局面。其中一个重要原因就是外语教师的专业发展存在诸多负面影响因素,导致先进的外语教学理念和教学方法难以有效应用于大学英语教学实践中,严重阻碍了我国高校外语教学质量的提高。如何更好地促进高校外语教师专业发展,提高高校外语教师专业素质和教学水平已经成为我们应该重视并解决的问题。     

A customised approach to determining the geomorphic effectiveness of small flood events in a regulated river

The construction of dams significantly alters flow and sediment regimes with subsequent deleterious effects on the morphological and ecological character of rivers. Effective experimental floods can ameliorate the downstream geomorphic impacts of dams. The traditional view is that large floods are required to perform effective geomorphic work, and the geomorphic outcomes of small floods are often overlooked. Many river restoration frameworks do not consider small floods. Yet, there is evidence that the hydrological characteristics that ameliorate specific geomorphic impacts in a river are unique to each river, and a customised approach to setting the right mix of floods (including small experimental floods) is needed. In this study, we modify an existing flood effectiveness model developed for large floods, for determining the geomorphic effectiveness of small floods in a highly regulated Australian river. Two flood classes were added to the model (medium peak stream power and moderate total energy expenditure), and the flood power characteristics were rescaled to reflect the relative difference in the magnitude of the small floods and the magnitude of the geomorphic work performed. Using a step‐wise approach, this customised model determined the geomorphic effectiveness of small floods. The best flood for ameliorating the geomorphic impacts of flow regulation had medium to long duration (10 to 51 days), high peak unit stream power (77 to 123 Wm^?2) and moderate to large total energy expenditure (78,600 to 342,320 × 10³ J). This approach to determining flood effectiveness for small floods is applicable to other geomorphically impacted river channels downstream of dams and can be used to inform experimental flood releases for geomorphic outcomes.     

装载机工作装置动态载荷测试方法与试验研究

为获得装载机铲装作业过程中工作装置各铰接点处的动态载荷时间历程,基于达朗贝尔原理建立了动平衡状态下工作装置的受力模型,提出一种考虑构件重力和惯性力的动态载荷测试方法.构建铰点力、油缸压力、油缸位移和动臂应变等多参数同步采集系统,进行散状物料铲装试验,获得了求解受力模型的基础数据.建立动臂有限元仿真分析模型,对比分析测点应力实测值和仿真值.结果表明:提出的测试方法获得的结构应力值能够准确地反映工作装置在铲掘作业过程中的应力分布规律,仿真值与实测值的变化趋势一致,验证了数学模型和测试方法的合理性.     

Support principles of NPR bolt/cable and control techniques of large-deformation disasters

Deep mining has been paid much more attention because of the depletion of shallow mining resources.Traditional bolts could be invalid to accommodate large displacement and deformation in geomaterials.Consequently, alternative support and reinforcement bolts need to be studied and their constitutive models also need to be developed to help understanding for the complex stress-strain responses of rock masses under loadings. The effect of Negative Poisson's Ratio(NPR) that is attributed to the swelling phenomenon along the lateral direction may appear in metal materials under tensional loadings. Thence NPR materials often have an advantage over NPR ones in mechanical behavior such as impact resistance, antishearing, and energy absorbed. From the characteristics of NPR materials, a series of bolt and cable supports with the effect of NPR and constant-resistance have been recently developed. We here firstly introduce the structural features of NPR support. Then the constitutive model of NPR support is presented and its corresponding equation of energy equilibrium. Its basic principle interacted on rock masses is further discussed. Finally, NPR cables are employed to support the slope of an open-pit mine. The applications show that NPR cables can ease failure within the slope and play an important role in predicting and providing early warning of slope failure, together with a monitoring system of slope stability.     

基于应用型人才培养的高职院校校企合作问题研究

经过近十年的发展,随着人才培养目标向市场倾斜,高职教育越发重视校企合作,努力实现产学研结合。但现阶段,高职教育校企合作依然存在着不可忽视的问题,如企业积极性不高、学校对企业服务能力有限、政策支持力度不够等。需要积极探索研究,创新合作思路,校企合作过程中真正实现双方共赢。     

施工宽缝对整体式闸首底板的受力影响研究

鉴于整体式闸首底板在顺水流方向易出现裂缝,严重危害船闸的使用安全。本文提出的设置施工宽缝的施工方案可以有效改善整体式闸首底板开裂问题。首先运用ANSYS软件建立模型,对闸首结构进行有限元分析,进一步探索出施工宽缝对整体式闸首底板的应力与变形的影响,将应力计算结果转换成内力,最终研究出满足工程要求的最优合缝时间和设缝位置,从而为整体式船闸的施工提供参考。     

上海市光伏产业供应链金融模式分析

日趋严重的雾霾问题已经影响到社会的健康发展,发展光伏产业,改变能源结构迫在眉睫.通过调研,整理出目前上海地区光伏产业主要的供应链金融模式,分析了各种模式的含义、优势及适用范围,旨在缓解光伏企业的融资难问题,促进光伏行业的健康快速发展.     

基于资产全寿命周期管理体系的设备资产状态监测评价分析

从资产管理体系、状态监测评价指标及职责界定、管理流程及控制等方面,介绍了国网江苏省电力公司检修分公司实施的资产管理状态监测控制程序.通过加强资产管理状态监测工作的规范化、标准化和程序化,提高了资产管理状态监测水平,从而实现了公司管辖范围内按需、及时、有效地开展资产管理状态监测活动,确保江苏省电力公司主网各项生产活动安全、有序、高效地开展.     

多约束条件下矩阵方程AXA~T=B的最小二乘解

为了求解大型矩阵方程的多约束优化问题,基于Dykstra交替投影算法和相关的矩阵分解理论,提出了求解矩阵方程AXAT=B的多约束条件下的最小二乘解的迭代算法,并讨论了算法的收敛性。数值实验验证了算法的有效性。     

电器空气冷却系统受海拔影响的理论分析

电器设备的散热能力与海拔高度有着密切的关系,不同的海拔高度空气的性能差别很大,比如空气的密度、压力、温度等都会因为海拔高度的变化而变化。这些参数对电器的散热有重要的影响。为了准确地进行不同海拔高度电子设备的热设计,建立不同海拔高度风扇主要参数数学模型,研究流体介质的流动状态变化对传热的影响,引入海拔高度参数,对原来建立在海平面上的传热方程进行修正,通过实例计算和Icepak14.5仿真对文中的理论进行验证,其结果也符合国际电工试验数据,为计算机等电器设备数字化热设计提供参考。