浅谈对数学概念的教学

数学概念是反映数学对象的本质特征的一种数学的思维形式,是构成数学知识的基础,学好数学概念是学习数学知识的重要前提。因此,数学概念的教学是数学教师课堂教学中的重要环节,同时也是数学教学的一项必备技能,所以我们必须重视数学概念的教学,深入钻研数学概念教学的方法。     

高职院校图书馆采编工作引入ISO9000后的改进效用探讨

目前,高职院校图书馆采编工作面临一些突出的现实问题,不仅影响到采编工作的质量效益和管理水平,也直接影响到图书、期刊与报纸等纸质资源的馆藏质量、广大师生读者满意率和图书馆窗口服务水平,引入ISO9000质量管理体系,并贯穿实施于整个采编业务的全过程,可以全面提升图书馆采编工作质量和管理水平。     

高压禁油数字压力计检定方法的探讨

阐述了在检定数字压力计时遇到的一种高压禁油数字压力计,这种压力计准确度高（±0．1％）、测量范围大（0—10MPa）,在检定时必须禁止和任何有油物质接触。现用常规检定标准器有数字压力发生器（准确度±0．01％,测量范围-0．1～314MPa）和一等活塞式压力计（准确度±0．02％,测量范围0～60MPa）两种。一等活塞式压力计使用的工作介质是蓖麻油,是检定二等活塞式压力计专用的标准器,受地区重力加速度的影响输出的压力值也不是整数,所有标准器都不能满足这种数字压力计的检定条件,而建立一套满足该检定条件的标准装置投资成本较高。通过实验、研究、分析,摸索出一种用一等活塞式压力计检定这种高压禁油数字压力计的方法。     

筏基施工的质量检测方法及存在的问题分析

阐述了河南油田某3幢小高层筏基施工的质量检测方法及其标准与依据。指出了该建筑的筏基使用水泥、同条件养护砼试块等的主要检测内容及检测结果。在影响砼强度的诸多因素中,水灰比过大或过小是对混凝土强度降低的主要影响因素。并针对存在的问题探讨了有关的应对措施．     

东北某探区油页岩资源开发项目经济评价

油页岩资源经济评价的主要任务是评价油页岩开发建设项目的经济可行性,常用的评价方法有静态法和动态法两种,关键指标有财务内部收益率、投资回收期、净现值和现值指数等。文章以东北某探区油页岩开发项目为例,采用动态评价方法对该项目的经济可行性进行了研究,并具体介绍了相关指标的选取方法,对于提高油页岩开发项目经济评价的准确性和决策效率有一定的参考作用。     

‘I didn't feel like I was alone anymore’: evaluating self‐organised employee coping practices conducted via Facebook

The long‐term fracturing of the labour movement has led to increased attention to employee coping practices under new management practices and labour processes. However, the literature caters little for the recent rise of employees taking to social networking sites (SNSs), such as Facebook, to find ways to cope with the pressures of contemporary employment. To explore the self‐organised coping qualities of SNSs, interviews were conducted with front line workers, employed by a large anti‐trade union US retailer, who contribute to a self‐organised Facebook group set up as a place for fellow employees to deal with collective employment‐related problems. The main findings suggest employee self‐organised Facebook groups represent an important development and extension to the coping practices available to individual and groups of employees. The main implication of the findings is that Facebook groups appear to strengthen and widen the options for employee resilience in an age of continuing trade union retreat.     

The world in 2050 and the New Welfare scenario

The PASHMINA (paradigm shifts modeling and innovative approaches) project grew out of the need to improve our understanding of the paradigm shift in the energy-transport-landuse nexus and, more broadly, in world development. In envisioning the world at 2050, we envisaged future growth in four possible directions: growth without limits, growth within limits, stagnation, and New Welfare. The scenario considered as preferable reflects a transition toward a New Welfare, characterized by a high level of cooperation, heightened concern for the environment and for social welfare, and an increased share of immaterial consumption. This scenario is based on the recognition that the development of new technologies – although relevant – turns out to be insufficient to resolve the issue of resource scarcity alone. Important behavioral changes are also needed. In the New Welfare scenario, GDP as a measure of growth becomes obsolete and needs to be replaced with ways of measuring progress that are more reflective of natural, human, and social capital. The New Welfare scenario also charts a pathway toward a low-carbon future, with an overall reduction in energy consumption, density, and intensity, and a greatly reduced reliance on fossil fuels. A new, smart electric grid facilitates active demand management and decentralized production of power. Natural gas or even small nuclear plants tackle problems associated with the intermittency of renewable energy sources. Among other likely shifts under this scenario is a re-conceptualization of production, from short-lived to longer-lasting goods and from private to open source knowledge products and services; growth in recycling and zero-waste processes; and a shift from profit-driven business to entrepreneurship that seeks to satisfy social needs and build local capital. The world undergoes a transition from unequal growth to prosperity in a multi-polar, globally interdependent world. New global democracy networks and institutions are created, and constitutions extend beyond the protection of human rights to the recognition of “nature rights.” Citizens’ income is tied to the social welfare-oriented duties and participatory governance. This scenario further leaves room to new forms of self-regulation of common resources. Actions necessary for the shift to the New Welfare paradigm include the adoption of new metrics for measuring progress, measures to increase public acceptance of technological and societal change, the creation of new global and local institutions devoted to sustainable management of shared environmental resources, sustainable production and consumption patterns, and a low-carbon energy and transport systems.     

中国管理会计的未来发展: 研究方法、热点实务和人才培养

本文从研究方法、热点实务和人才培养三个方面,讨论了我国管理会计发展的现状、面临的 问题和未来发展,目的是为我国研究者的研究提供一些新研究思路和选题、为我国实际工作者组织实务勾 勒一个基本的方向。     

曲面响应法预测砂浆性能的试验研究

本试验以砂浆性能为研究对象,采用Box-Behnken的中心组合实验设计及响应面分析方法对腻子粘结强度进行预测研究。试验选用三因素三水平的响应曲面分析法,建立了粘结强度的二次多项数学模型,并以粘结强度为响应值作响应面和等高线,考察了水粉比、灰粉比和胶粉比对粘结强度的影响,并根据实际选择响应曲面方程,利用最小二乘法估计相应的系数,剔除最不显著因素,建立最终的数学方程。结果表明:该预测模型能很好地描述粘结强度与水粉比、灰粉比和胶粉比之间的关系,可以对腻子粘结强度进行分析和预测,为砂浆性能研究提供一种新方法。     

Hybridizing local and generic information to model cropping system spatial distribution in an agricultural landscape

For quantitative water management, fine analysis of spatial and temporal interactions between cropping systems and water resources helps identify time and site-specific withdrawal situations. However, it is a methodological challenge to provide fine-resolution analyses at the scale of large watersheds used for crises management. In this study, we present a methodology based on multiple methods and mixed sources of information to finely model an agricultural landscape (AL) that represents the spatial distribution of cropping systems. Our approach is based on progressively hybridizing databases and local actors' and experts' knowledge to produce a spatially explicit and dynamic model. The Land Parcel Identification System database, which resulted from the European Common Agricultural Policy, is crucial for our method since it provides the spatial and temporal basis of our model (i.e., geographic delineation of islets and information about crop sequences). Local knowledge is used to identify factors determining spatial distribution of cropping systems and to build a generic model that simulates farmers' crop-management strategies. The model was qualitatively and quantitatively evaluated using a multi-agent simulation platform (MAELIA). We asked local experts on quantitative water management to evaluate the ability of the platform to reproduce intra- and inter-annual dynamics at different levels when using our model of the AL as input. The experts were satisfied with the results; they validated the predicted dynamics of the variables, and some discussed the objectivity of the values. We discuss the method’s contribution to current challenges in modeling large agricultural areas and the associated tradeoffs. The approach is promising for policy makers who wish to develop integrated, locally adapted land-management strategies.