试述高速切削刀具材料的研究与选择

近年来,随着CNC加工技术的迅猛发展以及数控机床的普遍使用,刀具材料也不断更新和发展,高速切削加工已成为现代切削加工中不可缺少的重要手段。高速切削加工的切削速度是常规切削的5～10倍,对刀具材料以及刀具结构、几何参数等都提出了新的要求,尤其是对刀具的材料有更高的要求,高速切削刀具的材料要具有高的强度、韧性和硬度,良好的热稳定性和热硬性、良好的高温力学性能、较小的化学亲合力和耐磨性。这里就针对高速切削的刀具材料和性能及其合理选择措施进行探讨。     

高温条件下合金零件切削的工艺研究

在分析研究镍基高温合金Incone1625零件(即连接轴)的切削加工工艺的基础上,通过对不同刀具(包括涂层刀具)的性能进行分析研究,总结出合理有效的加工工艺方案,攻克了高温合金加工的难点,并延长了刀具的使用寿命,从而降低了制造成本.     

高速切削刀具材料的合理选择措施探析

近年来，随着CNC加工技术的迅猛发展以及数控机床的普遍使用，刀具材料也不断更新和发展，高速切削加工已成为现代切削加工中不可缺少的重要手段。高速切削加工的切削速度是常规切削的5～10倍，对刀具材料以及刀具结构、几何参数等都提出了新的要求，尤其是对刀具的材料有更高的要求，高速切削刀具的材料要具有高的强度、韧性和硬度，良好的热稳定性和热硬性、良好的高温力学性能、较小的化学亲合力和耐磨性。这里就针对高速切削的刀具材料和性能及其合理选择措施进行探讨。     

难加工材料高效高速加工探讨

航空发动机零件大量采用难加工材料钛合金、高温合金等,这些难加工材料的高效切削技术已经成为航空发动机制造的关键技术之一。文章通过对难加工材料断续切削和高温合金整体环形机匣加工工艺的研究,摸索出了如何优化刀具方案和切削参数,改进工艺路线和加工程序提高难加工材料零件的效率的方法。     

如何合理选择高速切削刀具材料

高速加工是制造业发展的重要趋势,由高速加工而产生的高速切削已经成为先进制造工艺的关键技术.基于当今刀具材料的发展还不能满足各领域需求的现状,本文分析了在高速切削中刀具材料和工件材料的匹配问题,介绍了刀具在高速切削中的地位、高速切削对刀具材料的要求以及现有高速切削刀具材料的种类,分析了在高速切削中刀具材料和工件材料的匹配,阐述了如何合理选择高速切削刀具材料.     

高速切削加工对刀具材料的要求及其合理选用

刀具是实现高速切削加工的关键,文章阐述了高速切削加工对刀具材料的要求、高速切削加工刀具材料的种类及其合理选用。     

浅谈高温合金的切削加工

高温合金是现代航天、航空、航海及核工业上必需的金属材料,高温合金的切削加工是现代机械加工技术中一个难点。本文首先简要介绍了高温合金切削加工的特点,然后介绍了高温合金的车削加工中刀具的选择及其加工中应注意的若干问题。     

高速数控切削加工中的刀具研究

高速数控切削加工已成为机械制造的主流发展方向。高速切削时,随着切削速度的提高,切削力逐渐减小,切削温升逐渐趋缓,加工表面质量提高,加工成本降低。为实现切削加工的高速化,必须研究及开发与高速切削相适应的刀具材料、刀具结构及刀具监控技术。     

涂层刀具推进切削加工发展

刀具涂层技术的问世,对刀具性能的改善和加工技术的进步起着重要作用,涂层刀具往往是解决某些难加工材料加工工艺的关键措施,是高效、低耗的现代切削刀具的标志,在切削加工中得到广泛使用。     

高速数控切削加工中的刀具研究

高速数控切削加工已成为机械制造的主流发展方向。高速切削时，随着切削速度的提高，切削力逐渐减小，切削温升逐渐趋缓，加工表面质量提高，加工成本降低。为实现切削加工的高速化，必须研究及开发与高速切削相适应的刀具材料、刀具结构及刀具监控技术。     

The Theory of Socially Embedded Games: The Mathematics of Social Relationships,Rule Complexes,and Action Modalities

In their classic work, Von Neumann and Morgensterndefined a game as simply the totality of the rules which describe it. Theydid not, however, elaborate a theory of rules. Such considerations lead toconceptualizing rules and rule configurations as mathematical objects, specifyingthe principles for combining rules, developing the theory of revising,replacing, and, in general transforming rules and rule complexes. Themathematics is based on contemporary developments at the interface ofmathematics, logic, and computer science. This article, drawing on themathematical theory of rules and rule complexes, extends and generalizes gametheory (GGT). The theory of rule complexes is used to conceptualize andanalyze diverse social relationships, roles, and games as particulartypes of rule complexes. A social role, for instance, is the major basisof an individual's action in a game. It consists of at least four majorcomponents – which are mathematical objects – in the determinationof action: value complex, model of reality (including beliefs and knowledgebases), a repertoire of acts, routines, programs, and strategies, and modalities,role-specific algorithms for determininig or generating action in gamesettings. The article focuses on three types of action modality routineor habitual, normative, andinstrumental modalities. The theory: (1) provides a cultural/institutionalbasis for a theory of gameswhere games, social relationships, and rolesare formalized in terms of rule complexes; (2) explains human action as a formof rule application or rule-following action, which underlies allmodalities of action; (3) formulates the theory that actors construct an action or make choices amongalternative actions by making comparisons and judging similarity (ordissimilarity) between an option or options considered and their norms and values,and, in general, determine whether or not, and to what degree, a value,norm, or goal will be realized or satisfied; (4)reconceptualizes ``game' as a social form and makes a distinction between open and closed games.     

电子音乐流派的社会变革(英文)

从社会和政治变化、电子音乐流派的发展,形成了电子音乐,科学和技术的发展对电子音乐有重大的影响。他们是四个不同历史时期的发展——未来派,法西斯主义,达达派、电子音乐的时期。从最早使用:麦架,嘘声,窃窃私语,爆炸等。音乐和表达感情的表现,在阶级斗争,政治变革和经济危机、发展迅速的电子音乐,用在许多不同的零件,例如播放音乐、电影、电视等,都成了一个必不可少的组成部分的音乐市场。     

WHAT'S TO KNOW ABOUT THE CREDIBILITY OF EMPIRICAL ECONOMICS?

The scientific credibility of economics is itself a scientific question that can be addressed with both theoretical speculations and empirical data. In this review, we examine the major parameters that are expected to affect the credibility of empirical economics: sample size, magnitude of pursued effects, number and pre‐selection of tested relationships, flexibility and lack of standardization in designs, definitions, outcomes and analyses, financial and other interests and prejudices, and the multiplicity and fragmentation of efforts. We summarize and discuss the empirical evidence on the lack of a robust reproducibility culture in economics and business research, the prevalence of potential publication and other selective reporting biases, and other failures and biases in the market of scientific information. Overall, the credibility of the economics literature is likely to be modest or even low.     

Towards a Theory of Serendipity: A Systematic Review and Conceptualization

Serendipity – the notion of making surprising and valuable discoveries – plays a major role in the success of individuals and organizations alike. Previous research has established the importance of serendipity and identified important individual- and organizational-level antecedents. However, the literature has been dispersed and the boundaries of the concept have been blurry, leading to a lack of conceptual clarity and structure, and thus limiting validity and managerial actionability. Based on a systematic literature review, I synthesize existing management-related research on serendipity and explicate the emergence and composition of serendipity in the organizational context. I first identify three necessary conditions that differentiate serendipity from related concepts such as luck or targeted innovation: agency, surprise, and value. Then, I draw from the literature on sensemaking, event-based theorizing, and quantum-based approaches to management to conceptualize the process of cultivating serendipity in the organizational context as a process of enabling potentiality and materialization, and develop a multi-level theory of (cultivating) serendipity. This conceptualization contributes to our collective understanding of how, why, and when (i.e., under what conditions) organizations can leverage the value in the unexpected, which opens up fruitful avenues for further research.     

Supply Chain Strategies in the UK Fashion Industry—The Rhetoric of Partnership and Realities of Power

This paper focuses on the fashion industry, one characterised by issues such as dramatic shifts in the scale and power of major retail buyers in the market, the advent of retailer own brands, and the nature of sourcing and supply chain decisions, issues that are increasingly global in nature. The aim of this research is to explore the nature of relationships between UK high street multiple fashion retailers and their contracted suppliers, many of whom are entrepreneurial firms by most definitions of the term. Four core themes emerge from the literature and provide a framework for the research, namely, power, process, partnership, and people. The research approach was qualitative, and conducted over a period of twelve months. The paper ends with an agenda for future research.     

Engineering Cities: Mediating Materialities,Infrastructural Imaginaries and Shifting Regimes of Urban Expertise

This symposium opens up new critical insights and analytical perspectives into the relationships between power, politics, materiality and urban engineering. In so doing it demonstrates the central role of engineers in the production and negotiation of everyday life in the city. In contrast to the technocratic exercise engineering often professes to be, the contributors to this symposium argue that the assembling and choreography of cities through the myriad techniques, routines, standards and visions of engineers is inextricably bound up with broader socio‐cultural, material and political urban dynamics and processes. This necessitates investigating the multiple and competing social imaginations, forms of knowledge and regimes of expertise associated with urban engineering. The symposium's five articles, straddling disciplinary backgrounds in geography, anthropology, engineering and history, focus analytical and empirical attention on the figure of the engineer and on the work of engineering in the cities of Paris, Mumbai, Singapore and London. Engineering, we suggest, is a diagnostic for probing the shifting forms of mediation that animate and inhabit contemporary dynamics of urban change. The symposium thus opens up a new avenue for cross‐disciplinary and transregional research for urban studies while also suggesting innovative ways of conceptualizing urban transformation and contestation.     

公路工程施工组织设计探析

近些年,国家对基础性建设的投入越来越大,我们的公路建设也日益增多。公路工程是一项综合性、系统性较强的工程,是集路基、路面、路线、桥涵、隧道等于一体的综合体系。随着经济社会的发展和施工工艺的不断进步,人们对公路工程的要求也更加严格。为了保证公路建设的正常施工,就需要工程设计按时按量完成。而如何处理好质量与工期的矛盾则是公路设计者面临的难题。本文对公路工程设计的重要性,步骤等进行一个分析研究。     

The Geography of Innovation in China and India

The BRICS countries in general, and China and India in particular, are now widely regarded as the areas of the world likely to challenge the economic leadership of the United States (US) and the European Union (EU). A large part of this challenge will come from rapid technological catch‐up by China and India. Yet, despite a recent rise in interest, there is limited knowledge about how and where innovation takes place in these two leading emerging countries and to what extent the Chinese and Indian territorial systems of innovation differ from those in the EU or the US. In this article we explore the geography of innovation in China and India, concentrating on understanding key territorial‐level innovation trends by country, region and technology field, using the US and the EU as benchmarks. We find significant contrasts between the geography of innovation in China and India and that of the US and the EU. First, the degree of concentration of innovative activities in both countries is extremely high. Levels of agglomeration of innovation in the coastal provinces of China, as well as in Delhi and the South of India, significantly exceed the levels of agglomeration found in the USA and the EU. Secondly, China has witnessed a more rapid increase in the degree of concentration of innovation than India. We posit that the differences in the geography of innovation between, on the one hand, China and India and, on the other hand, between these countries and the developed world are rooted in different institutional settings, different systems of innovation and different national innovation strategies.     

文化与科技融合的实现路径

文化发展与科技创新两者交织融合,科技创新是文化发展的重要引擎,文化发展也成为科技创新的引领。文化与科技融合本质是由科技突破和技术创新所带来文化产业在生产方式、消费方式、产业形态和产业结构等方面的变革,融合的核心是价值链重构,融合广泛发生在产业、市场、企业和生产要素等领域。目前,我国文化与科技的融合相对滞后,发展压力与发展机遇并存。从路径上来说,可从产业、市场、企业和人才四个方面实现文化与科技的融合。     

Urban Waterscapes: The Hydro‐Politics of Flooding in a Sinking City

The threat of flooding in cities is often compounded by political and economic decisions made on watershed management, land development and water infrastructure and provisioning. It has also become a point of conflict between cities’ objectives for development and modernization, and the struggles of marginalized residents living in low‐lying coastal and riverine areas to remain in place. Flooding takes on different forms depending on one's point of view. It is a biophysical issue, involving geology, geography, meteorology and ecology. It is one of urban governance, involving planning and maintenance of infrastructure and land use. And it is sociopolitical, involving historical social and spatial marginalization and contestation. This article, based on mixed‐methods research in Jakarta, Indonesia, traces the conceptual and physical contours of urban waterscapes across these conflicting ideas and narratives. It brings into dialogue theories of urban political ecology, landscape ecology and environmental ethnography to explore the interrelationships between biophysical and sociopolitical factors behind urban flooding. In the article the focus is on the varying materialities and scales involved, including the ecological scales of the watershed, the infrastructural scales associated with flood protection, and the urban scales of planning, governance and social activism. The article concludes with a proposition for a multidimensional approach to thinking and acting on problems of urban ecological change.