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71.
王昌豪 《价值工程》2014,(32):67-68
当支架工作一定时间后出井维护时,需要将前梁与顶梁之间的销轴拿掉后改为运输销轴连接,由于井底空间、设备有限,操作极为不便;另外,由于前梁千斤顶是靠销轴受力,因为支架工作时间比较长且井下环境恶劣,导致销轴出现变形、生锈等现象,以致销轴不易拆卸。  相似文献   
72.
笔者以新建兰渝铁路六标段花石隧道为例,对该隧道的应有的通风设计,结合现有通风方式的弊端和改进,进行浅要的比较分析,在此基础上对同类型隧道的通风选型进行总结。  相似文献   
73.
李琪炯 《价值工程》2014,(2):253-254
公共图书馆作为公共文化服务体系的重要组成部分,在构建学习型社会的大背景下,为促进终身学习的理念,借鉴国外图书馆的前沿探索,提升人文素质和知识内涵,实现公共图书馆在新的历史形势下自身的转型与发展。  相似文献   
74.
Sustainable entrepreneurship contributes to solving social and environmental problems through the means of successful for‐profit businesses. This paper contributes to understanding how sustainable entrepreneurship is implemented by exploring an emerging new form of business, ‘B Corps’, that employs market tactics to address social and environmental issues. Through interviewing 14 B Corps, the exploratory research study found that B Corps treat profit as a means to achieve positive societal ends, they regard the B Corp model as a tool for change, the B Corp model provides a common collective identity for internal and external validation, they are focused on societal impact rather than maximizing profits and they attempt to legitimate this form of sustainable entrepreneurship by influencing the business community and government officials. Copyright © 2016 John Wiley & Sons, Ltd and ERP Environment  相似文献   
75.
Most small-scale social economies are characterised by their deficiency, lack, and/or difficulty in matching natural data. Against this backdrop, this paper builds a relatively uniform theoretical framework and designs a more economical and objective method for demarcating ecological conservation redlines (ECR) based on sensitivity assessment of ecosystem services. The results show that the sensitivity assessment model designed in this study can identify sensitive zones effectively, and that the ECR in Hubei Province are well within the sensitive zones so identified. The delimited areas based on the sensitive assessment of ecosystem services have great similarities (95%) with the actual ECR areas in Hubei Province. The most ecologically important functional zones (EIFZ) can also be identified using the regional ecological sensitivity coefficient. When the threshold of EIFZ is set higher, the probability that it falls within the ecologically sensitive areas is greater and the ECR delimited by the method proposed in this study will be more reliable. Theoretically, the delimitation of ECR can be inserted at any evaluation level with a grid resolution higher than that of the land use data, which can be used as a supplement to the ECR delimitation method in ecology or geography.  相似文献   
76.
One‐sample and multi‐sample tests on the concentration parameter of Fisher‐von Mises‐Langevin distributions on (hyper‐)spheres have been well studied in the literature. However, only little is known about their behaviour under local alternatives, which is due to complications inherent to the curved nature of the parameter space. The aim of the present paper therefore consists in filling that gap by having recourse to the Le Cam methodology, which has recently been adapted from the linear to the spherical setup. We obtain explicit expressions of the powers for the most efficient one‐ and multi‐sample tests. As a nice by‐product, we are also able to write down the powers (against local Fisher‐von Mises‐Langevin alternatives) of the celebrated Rayleigh test of uniformity. A Monte Carlo simulation study confirms our theoretical findings and shows the empirical powers of the above‐mentioned procedures.  相似文献   
77.
Charitable foundations and government programmes should endeavour to allocate their limited resources to best serve their constituents. Yet, mathematical programming techniques are rarely used despite overwhelming evidence of their superiority in selecting projects that yield higher levels of total benefits. We present a novel ‘hybrid selection model’ that combines binary linear programming and heuristic rank-based models applied to two case studies. The first case focuses on providing services to women and shows a hybrid model would have selected the top three ‘signature’ projects and maintained an above-average overall project benefit while securing a 180% improvement in the number of projects funded, a 66% improvement in the number of women served and a 132% improvement in the total benefit achieved. In the second case, we apply the hybrid approach to data from the US government’s largest forest preservation programme and demonstrate that the hybrid approach could allow the programme to select up to 11 top-scoring projects while still achieving a 97% gain in the total overall benefit compared to their traditional method. These case studies show that the hybrid approach has the potential to be applied in a variety of settings and improve how foundations and programmes achieve their goals.  相似文献   
78.
孔海东  张培  刘兵 《技术经济》2019,35(6):99-108
通过文献调查并结合案例的描述性分析,提出数字技术时代价值网络中不同行为主体之间的赋能内涵、关键维度以及基于赋能跨层次效应的价值共创行为分析框架。将"赋能氛围""主体赋能"分别作为价值网络中赋能的宏观维度和微观维度进行概念化。界定了两个维度的关键组成要素,分别包括信息共享、开放性结构、协同规则以及主体关系、资源整合和影响。构建了赋能的跨层次效应模型,分析了赋能的宏观-微观跨层次效应及其对价值网络生态和主体价值创造的影响。  相似文献   
79.
This research looks at post‐2006‐war reconstruction of the southern suburbs of Beirut under the auspices of Hezbollah (the Islamic resistance movement in Lebanon). The project was widely acclaimed as an alternative to current neoliberal planning practices in the Middle East and beyond. Based on a critical reading of the conception of property issues in this planning project, the article argues that this reconstruction presents a new geometry or alternative to the mainstream configuration of neoliberal urbanism, rather than a departure from its precepts. The reason for this is that the adopted language of property corresponds closely with the conception of property advocated by neoliberal planning, one that enshrines private, individual ownership as sacred and desirable and that works to strengthen its model in the city. I further argue that the ‘neoliberal planning regime’ within which Hezbollah's urban intervention occurs is not accidental; rather, it is necessary for the party's control of this space's future and for consolidating its territory in the city. It is hence expected that Hezbollah's planning in the city will produce the same decried effects as neoliberal planning elsewhere in the city rather than usher an innovative, progressive model of planning.  相似文献   
80.
This article investigates how consumers categorize new hybrid products (NHPs). Given the limitations of the classical theories of categorization in the specific case of NHP, affordance, mobilized infrequently in marketing, turned out to be a useful categorization concept. Five types of NHP categorizations by consumers, based on the degree of affordance (low vs. high) and type of innovation (incremental vs. radical), have been detected and filled a gap in the literature on the subject.  相似文献   
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