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11.
论三峡水库“蓄清排浑”运用方式及其优化   总被引:1,自引:0,他引:1  
泥沙问题是三峡工程的关键技术问题之一,在三峡工程论证和初步设计阶段提出水库采取"蓄清排浑"的运用方式,可以解决泥沙问题。2003年水库蓄水运用以来的实践表明,水库基本遵循了"蓄清排浑"调度运用原则,并根据上游来水来沙减少等新情况对水库运用方式进行了优化调整。本文系统分析了三峡水库"蓄清排浑"运行方式及其优化调整的利弊,包括提前5年实施175 m试验性蓄水、汛期水位动态变化、汛末提前蓄水等对水库淤积和坝下游河道演变的影响,提出了进一步优化水库调度方式,形成"蓄清排浑"运用的新模式,保持水库长期使用的建议,试图为三峡水库科学高效安全运用提供科技支撑。  相似文献   
12.
根据组织项目管理成熟度模型(OPM3),确定影响项目组合管理能力的OPM3要素,分析OPM3要素与项目组合管理能力的因果关系,构建系统动力学模型,仿真模拟OPM3要素对项目组合管理能力的影响。仿真结果表明:OPM3要素与项目组合管理能力正相关;OPM3要素对项目组合管理能力的影响在短期内并不显著;在OPM3要素中,对项目组合管理能力影响较为显著的是战略执行与规划、组织领导能力和信息分析。  相似文献   
13.
为探究南水北调中线水源区丹江口水库浮游植物群落结构变化及其生物多样性,于 2014—2015 年对丹江 口水库进行为期 1 年的调查和分析。发现浮游植物共 8 门 76 属 101 种,其中,绿藻门、蓝藻门及硅藻门占总种数 90.10%,绿藻门种类数最多(45 种),其次是蓝藻门(26 种)和硅藻门(20 种)。浮游植物群落结构随季节变化有所 不同:夏秋季节生物量明显高于冬春季节;优势种在冬季以颗粒直链藻、颗粒直链藻极狭变种、铜绿微囊藻和小 环藻为主,春季以球衣藻、薄甲藻属及小环藻为主,夏季以简单颤藻、单胞衣藻原变种和球衣藻为主,秋季以类颤 藻鱼腥藻、简单颤藻、球衣藻和小环藻为主。应用 Shannon-Wiener 多样性指数 H′、Pielou 均匀度指数 J′、Margalef 丰富度指数 Dm评价水质结果表明:丹江口水库夏秋季水体营养化程度更高。典型对应分析表明:水温、透明度、 总氮、总磷等是影响浮游植物群落结构的主要环境因子,夏秋季受温度影响蓝藻、绿藻数量逐渐增多,一定程度 上增加了受水区生态变化风险。本研究可为南水北调中线水源区丹江口水库生态环境变化及生物迁移风险提供 数据支持。  相似文献   
14.
Due to the increasing complexity and flexibility of business activities, project-based organizations have become common. In such organizations, project management competencies, which refer to a collection of knowledge, personal attitudes, skills, and relevant experience, are core assets that must be taken seriously. Formalized project management career paths have been widely implemented in the construction industry. However, most recent studies treat project management competencies as static constructs and fail to consider their dynamic changes as a career path advances. To fill this gap in the literature, this study conducted an empirical examination of project management competencies integrated with a career model for the construction industry. First, key project management competencies are identified through a literature review. Then, a project management career model for large Chinese construction companies is developed based on an empirical investigation of six large Chinese construction companies from various sectors. Moreover, a quantitative analysis is performed to explore how these competencies dynamically change as position levels rise in the career model. The research findings indicate that significant differences in project management competencies exist at different levels of the career model. However, the distribution remains steady at different project management position levels for conceptual and organizational competencies, human competencies, and technical competencies.  相似文献   
15.
In innovation and project management studies incremental development projects are perceived as theoreticlly and organisationally uninteresting. By means of a longitudinal study of product improvement projects at an automobile firm, this paper challenges such views and shows how the cumulative impact of the studied sequence resulted in a competitive repositioning of the company's product portfolio during a financially difficult period. Project managers achieved this by transcending the separation between exploration and exploitation projects; they not only adhered to time, cost and quality goals but also tried out new ways of testing and experimenting with controversial technical ideas. The paper analyzes the intensive inter project learning that generated these ambidextrous capabilities and emphasizes that practices at the project-level need to be buttressed by expanded management learning and capability development also at the sequence level.  相似文献   
16.
Although the management of inter-firm projects is increasingly being researched in a wide range of academic fields (project management, alliances and networks, organization studies), the findings of these studies rarely cross theoretical boundaries. In the present study, a systematic literature review of 219 contributions from 26 years of academic research on managing inter-firm projects identifies 22 key management issues underlying its contributions. Based on a two-dimensional framework (project stage and analytical sphere), a structured and integrative synthesis of relevant studies is outlined. Based on these findings, future investigations are proposed to focus on dynamic, contextual and structural aspects of the management of inter-firm projects.  相似文献   
17.
Risk allocation decisions are of critical importance in project management. The present study proposes an explanation for how risk allocation in a contract motivates a contractor to cooperate with a project owner. Theories of risk allocation and trust were used to motivate the research. Using a survey methodology, we collected data concerning 124 construction projects in China. We found that risk allocation influenced the contractor’s role behavior through the contractor’s feeling of being trusted but not the contractor’s trust in the owner. Feeling of being trusted partially mediated the effect of risk allocation on the contractor’s in-role (i.e., contractual) behavior and fully mediated the effect on extra-role behavior. The study introduces a social and psychological view of the impacts of risk allocation to the project and engineering management literature. We contribute to theory by arguing and demonstrating the mediating effect of trust on the relationship between risk allocation and contractor behavior. From a practical standpoint, we conclude that contractual risk allocation has a significant impact on building a trusting relationship between owners and contractors and that contractors who feel trusted perform both contractually mandated actions and actions external to the contract more diligently, resulting in the likelihood of improved outcomes for both parties.  相似文献   
18.
Project work is becoming more and more important in everyday business, as is staffing the right newcomers for the project. Recognizing that not all new project team workers possess equally important specific knowledge, skills and abilities for the success of projects, we draw on project management, human resource management, and organizational socialization literature to develop a framework on how new project team members might be socialized, depending on their strategic value for the project. We specifically draw on the socialization tactics literature and propose how four categories of new employees – Internal specialists, External specialists, External generalists and Internal generalists; based on two dimensions – work task complexity and employment mode, can be socialized more effectively. Implications for theory and practice are discussed as well.  相似文献   
19.
跨渠桥梁是南水北调中线工程的重要基础设施,危化品运输车辆一旦在跨渠桥梁上发生事故,不仅会对桥体结构造成很大损坏,还会对沿线水质产生较大污染。如果能及时发现,提前预警,就可以针对每座桥梁的情况提早防范,快速处理,将损失降到最低。针对以上需求建立基于智能视频分析的危化品车辆流量、类别监控识别与统计分析系统,采用智能监控和态势感知等建立了多层次、全方位预警决策和风险管控平台。平台功能涉及车辆流量、类别识别、统计分析技术和预警功能,能辨识经过跨渠桥梁的车辆,特别是能对危化品运输车辆出入桥梁的信息进行记录和流量统计,对车辆偏离车道、异常停车、翻车、冲入渠道等异常事件能第一时间进行信息报告与自动预警。该项目已付诸实施,为南水北调跨渠桥梁安全管控提供了新的技术防护手段。  相似文献   
20.
Agile practices become increasingly popular for projects and project portfolios offering firms a higher flexibility to adapt to dynamic environments. This study investigates the antecedents and consequences of agile practices' relevance for strategy formulation in project portfolio management processes. Building on complex adaptive systems theory, we hypothesize a positive relationship between agile capabilities and emerging strategy initiatives and eventually portfolio success. Agile capabilities refer to both the project portfolio organization's intensity of and competence in applying agile practices. Using a sample of 135 portfolios and multiple informants for each portfolio, the results support entrepreneurial orientation and voice behavior as antecedents for agile capabilities. Furthermore, the findings support an agile portfolio's positive relationship with emergence recognition and overall portfolio success. The findings contribute to the literature by identifying two significant antecedents of agile capabilities as well as empirically demonstrating the positive relationship between agile portfolios and emerging strategy recognition. For practitioners, the study encourages the application of agile practices by stressing the general positive influence of agile capabilities and underlines entrepreneurial orientation and voice behavior as important methods of empowerment for agile portfolio processes.  相似文献   
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