冲击压实机冲击力及冲击能量的计算

冲击压实机广泛用于建筑行业．目前对具有特殊外形的冲击压实机冲击轮的动力特性研究的不多．根据冲量定理和动能定理，对冲击压实机的冲击力和冲击能进行研究．利用冲击轮的特殊外形，对地面产生大的冲击力和冲击能，通过理论计算，其结果与同吨位的振动压实机相比，冲击力提高十倍，冲击能效果明显，为压实机的设计及改进提供可靠的理论依据。     

冲击荷载作用下钢框架的动态响应分析

在冲击荷载作用下,钢框架结构的动态响应是一个复杂的非线性过程。运用ANSYS/LS-DYNA建立了钢框架的三维模型,对冲击荷载作用下钢框架的动态响应和破坏形态进行研究。采取多点积分算法,有效避免沙漏问题,保证计算结果精确。以冲击块与钢框架的碰撞冲击为例,研究了冲击速度、冲击块质量、冲击位置等参数对钢框架在横向冲击作用下动力响应的影响,并分析冲击荷载下钢框架的破坏形态。结果表明:冲击块的质量、速度、冲击位置的增加都会不同程度地加剧钢框架的动态响应;在冲击作用下,高应变主要出现在被冲击柱子的冲击区域、柱脚处和梁柱节点处;冲击荷载下钢框架的破坏形态为整个框架发生侧移,受冲击柱在冲击处翼缘出现局部屈曲,受冲击区域的截面发生弯扭,未受冲击柱出现倾斜。     

基于灰色系统理论的绿色设计影响评估算法研究

生命周期评估(LCA)是绿色产品设计的一项重要内容, 影响评估是LCA的重要阶段. 本文将各种排放物影响因子进行分类后, 应用灰色系统理论, 提出了影响评估灰类划分及其白化权函数, 对各影响类别进行了灰色聚类分析, 然后根据分析结果给出了分类影响指数的计算方法. 根据各影响类别的作用范围, 将影响类别按全球影响、区域影响、本地影响进行了分组, 并给出了分组影响指数以及总体影响指数的计算方法. 最后, 以设计中的3种材料钢、铝、工程塑料为例, 说明了以上方法在一类产品比较选择中的应用.     

转子叶轮-定子触碰故障的分析与辨识

基于航空涡轮发动机和工业透平机中的转子叶轮定子间触碰故障背景 ,以力学建模为指导搭建了两类简支型的转子定子触碰故障实验台架 ,考察了转子定子间正常无触碰、早期尖锐型轻微触碰、中期半尖锐型触碰、晚期平钝型触碰 4种状态时转子振动位移的时域轨迹 ,观测到了早期尖锐型轻微触碰时伴生的混沌现象 .采用FFT方法对上述 4种状态试验数据的频率结构作了分析 ,结果表明当出现三分频以下 (包括三分频 )的分频特征时可以初步判断叶片发生了早期触碰 ,而当转子振动位移的频谱图中仅存有两分频分量甚至轴频分量时 ,叶片 -转子间的触碰故障已相当严重了 .     

比较文学"影响研究"新解

“影响研究”就是在“传播研究”所能提供的事实非常有限的条件下，提出文学影响的假说，并在此基础上对作家作品进行细致地分析和研究。在这个问题上，笔者不同意韦勒克等人关于“影响研究”“甚至不可能完整地研究一部艺术品”的看法，认为“影响研究”有三个阶段或三个层次：第一，提出“影响”的假说；第二，为论证影响假说而对具体作家作品进行分析，其中包括对主题、题材与情节的分析、对典型人物的解剖、对艺术手法艺术风格的对比等等，从而看出影响是否存在，如何存在，如何表现；第三，指出影响接受者如何超越影响，即“超影响”的研究，亦即研究影响的范围与限度、影响与独创的关系。     

Academic sell-out: how an obsession with metrics and rankings is damaging academia

Increasingly, academics have to demonstrate that their research has academic impact. Universities normally use journal rankings and journal impact factors to assess the research impact of individual academics. More recently, citation counts for individual articles and the h-index have also been used to measure the academic impact of academics. There are, however, several serious problems with relying on journal rankings, journal impact factors and citation counts. For example, articles without any impact may be published in highly ranked journals or journals with high impact factor, whereas articles with high impact could be published in lower ranked journals or journals with low impact factor. Citation counts can also be easily gamed and manipulated, and the h-index disadvantages early career academics. This paper discusses these and several other problems and suggests alternatives such as post-publication peer review and open-access journals.     

Firmness measurement of peach by impact force response

The impact force response of a peach impacting on a metal flat-surface was considered as nondestructive determination of firmness. The objectives were to analyze the effect of firmness, drop height, fruit mass, and impact orientation on the impact force parameters, and to establish a relationship between the impact force parameter and firmness. The effect of fruit firmness, drop height and fruit mass on the impact force parameters (coefficient of restitution, percentage of energy absorbed, and coefficient of force-time) was evaluated. The study found that the coefficient of restitution, percentage of energy absorbed, and force-time impact coefficient were significantly affected by fruit ripeness, but not affected by drop height, impact position (fruit cheek), and mass. The percentage of absorbed energy increased with ripeness, while the force-time impact coefficient and coefficient of restitution decreased with ripeness. Relationships were obtained between the three impact characteristic parameters (force-time impact coefficient, coefficient of restitution, and percentage of energy absorbed) and peach firmness using a polynomial model (R~2=0.932), S model (R~2=0.910), and exponential model (R~2=0.941), respectively.     

本科教学工作水平评估对高校教学工作影响的调查研究

对上海水产大学和上海师范大学教学科研人员和教学管理人员进行的问卷调查表明,本科教学工作水平评估对教学工作的影响是积极的,建立评估制度是保障高等教育质量的有效措施。调查揭示了评估对教学工作影响的一些特点:教学管理人员对评估影响的肯定程度高于教学科研人员;评估对教师教学和教学管理的影响大于对学生学习的影响;评估对教学工作的外在影响强于内在影响;评估对教学工作的影响随时间推移会逐渐减弱。     

Accessing participatory research impact and legacy: developing the evidence base for participatory approaches in health research

Action research has been characterised as systematic enquiry into practice, undertaken by those involved, with the aim changing and improving that practice: an approach designed to have impact. Whilst much has been written about the process and practice of ‘researching’, historically ‘impact’ has been somewhat taken for granted. In recent years, however, the impact of all forms of research has become the focus of interest with many funding bodies now demanding that researchers not only articulate the prospective impact of their work, but what kinds of evidence will be proffered to demonstrate that impact. This has raised questions for action researchers, not about whether their work has an impact, but what form that impact takes, how it is recognised and by whom. This paper focuses on difficulties researchers find in both articulating the impact of participatory research and demonstrating links between such forms of research and impact. We draw on discussions about the notion of impact with authors that have self-reported and published their work as participatory. These discussions revealed that not only were there difficulties in clarifying the participatory dimension of their research but that whilst authors were able to discuss particular impacts of their work, articulating and evidencing that impact was often absent from their published papers. This paper offers insights into some of issues and barriers those who undertake participatory research face in explicating, for the external audience (and indeed sometimes for ourselves), the impact of this action-based form of enquiry.     

Unpacking ontological security: A decolonial reading of scholarly impact

Despite the growing debate about scholarly impact, an analysis of the onto-epistemic grammar underlying impact has remained absent. By taking a different analytical approach to examining impact, we interrogate the concept through the lens of decolonial thought. We offer an empathetic review of the impact scholarship and illuminate the limits of the modern imaginary that circumscribe critiques of impact in the literature, making visible the Eurocentric and provincial horizons of modern reason underlying these critiques and impact in general. Drawing on ?ūnyatā ontological perspective, we seek to articulate from modernity imaginary’s edges and suggest imagining and being otherwise. We argue that the question of scholarly impact is intimately structured by and connected to the modern subject’s desire for ontological security.     

一类多自由度含间隙动力系统的混沌与控制

在一类含间隙多自由度动力系统的力学模型的基础上,根据系统在无碰撞情况下的无量纲微分方程和相应的无量纲冲击方程,利用龙格一库塔数值仿真方法揭示了系统存在复杂的混沌运动行为。理论分析了延迟反馈方法对混沌控制的有效性,相图和时间历程图均表明该方法能将系统的混沌行为有效地控制到周期轨道。     

Equivalent Kelvin Impact Model for Seismic Pounding Analysis of Bridges

Based on Hertz contact theory, a method to determine the parameters of Kelvin impact model for seismic pounding analysis of bridges is proposed. The impact stiffness of Kelvin model is determined by the ratio of maximum impact force to maximum contact deformation, which is calculated based on Hertz contact theory with considering the vibration effect. The restitution coefficient which has great influence on the damping coefficient of Kelvin impact model is investigated by numerical analysis. Numerical results indicate that the impact stiffness of Kelvin impact model increases with the increment of the Hertz contact stiffness, approaching velocity or the length ratio of short to long girders. Vibration effect has remarkable influence on the impact stiffness and cannot be neglected. The restitution coefficient decreases when approaching velocity increases or the length ratio of short girder to long girder decreasing. The practical ranges of impact stiffness and restitution coefficient are obtained as 3×108-6×108 N/m and 0.6-0.95 respectively.     

Numerical Simulations of Pile Supported Protective System Subjected to Ship Impact

The head-on collision process between ship and concrete pile supported protective system is simulated by software LS-DYNA. The influences of pile non-linearity and soil non-linearity on impact force, ship crush depth and the cap displacement of pile supported protective system are discussed. It's shown that for both severe impact case and non-severe impact case, the non-linearity of pile material influence the impact force history, ship crush depth. The non-linearity of pile material and soil has remarkable influence on the cap displacement especially for severe impact case. These issues should not be ignored in the analysis of pile supported protective system subjected to ship impact.     

荆门市财政支出结构对经济增长影响的实证分析

文章通过对1995-2006年荆门市财政支出结构对经济增长影响的实证分析,得出以下基本结论:银行信贷基本对经济有正的影响,且影响系数较大;企业挖潜改造支出、农业支出和科教文卫支出对荆门经济增长都具有正的影响。其中科教文卫支出影响最大,而行政管理支出则对经济增长不显著。最后,文章提出了相关政策建议。     

Assessment of Containment Structures Against Missile Impact Threats

In order to ensure the highest safety requirements, nuclear power plant structures (the containment structures, the fuel storages and transportation systems) should be assessed against all possible internal and external impact threats. The internal impact threats include kinetic missiles generated by the failure of high pressure vessels and pipes, the failure of high speed rotating machineries and accidental drops. The external impact threats may come from airborne missiles, aircraft impact, explosion blast and fragments. The impact effects of these threats on concrete and steel structures in a nuclear power plant are discussed. Methods and procedures for the impact assessment of nuclear power plants are introduced. Recent studies on penetration and perforation mechanics as well as progresses on dynamic properties of concrete-like materials are presented to increase the understanding of the impact effects on concrete containment structures.     

情绪对记忆影响研究新成果及其对教育领域的启示

情绪对记忆影响的研究是近年来认知心理学研究的热点问题。从情绪唤醒水平对记忆的影响、情绪对记忆内容的影响、情绪对记忆的主观确信感的影响等方面,介绍了近几年来国外以神经影像技术进行研究所取得的最新进展。对在教育领域运用情绪对记忆影响研究的新成果进行了探索,并提出了相关建议。     

A proposed framework and tool for non-economic research impact measurement

ABSTRACT

Research impact features heavily in debates about ‘the measured university’ and is now formally assessed by governments in the UK and Australia. Yet clear guidance on how impact can be measured in non-monetary ways is often lacking because of confused thinking and the context-specific nature of outcomes. To help resolve this, we first propose a general impact model of inputs, processes, outputs and outcomes framework. Then, using a survey approach of research users, we measure outcomes at different levels of abstraction using usefulness as the central construct and impact categories from the European (EU) and Association to Advance Collegiate Schools of Business (AACSB). The survey measures are simple, comparable between different impact cases, cost-effective, externally verifiable, and easily administered by those for whom impact measurement is new and puzzling. They can also be combined to form an impact index to address criticism that there is little standardisation in impact measurement. To improve the standardisation of context-specific measures, we suggest a common methodology for deriving these (SROI). The article discusses limitations of using surveys including administration, self-report data, and impact timescale problems, and suggests ways to reduce these. Implications for researchers, research managers, and assessors interested in measuring impact, such as who should do it and pay for it, are discussed.     

冲击的可靠性设计

用能量法求冲击应力和冲击变形．并将应力强度干涉模型运用于冲击问题,讨论了冲击的可靠性设计。     

Design of bridge expansion joints with perforated dowels under impact loading

The expansion joints are expected to have movement capacity, bearing capacity for static and dynamic loading, water-tightness, low noise emission and traffic safety. In particular, the failure due to impact loading is the main reason for the observed damages. The problem of dynamic behavior of the expansion joints is so complex that we shall focus our attention on the impact factor for vehicle load that is governed by traffic impact. In order to overcome this difficulty, the cantilever-toothed aluminum joint (finger joint) is one of the promising joints under impact loading. In this study, from the viewpoint of design methodology, numerical studies for impact behavior were conducted for aluminum alloy expansion joints with perforated dowels. The design impact factor for the expansion joints with the perforated dowels against traffic impact loading was examined by using numerical simulations.     

Conceptualizing impact in academic development: finding a way through

This paper explores the notion of impact in the context of academic development programs and considers how it can be described and understood. We argue that impact has a range of meanings and academic development programs such as graduate certificates have a broad group of stakeholders and hence the impact is different for each group depending on how the program aims and objectives are defined and understood. In finding a way through the difficulties of evaluating impact in academic development we point to the importance of clearly conceptualizing the notion of impact, a careful identification of the assumptions underpinning any program and an understanding of who academic development will benefit and how. We suggest that impact in academic development cannot be understood without taking account of the range of possible impacts and the difficulty of attributing simple cause and effect to a complex environment.