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LaB6 Work Function and Structural Stability under High Pressure
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作者 李鹏善 崔巍然 +6 位作者 李蕊 孙华蕾 李延春 杨栋亮 宫宇 李晖 李晓东 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第7期185-189,共5页
The work functions of the (110) and (10(3) surfaces of LaB6 are determined from ambient pressure to 39.1 GPa. The work function of the (110) surface slowly decreases but that of the (100) surface remains at a... The work functions of the (110) and (10(3) surfaces of LaB6 are determined from ambient pressure to 39.1 GPa. The work function of the (110) surface slowly decreases but that of the (100) surface remains at a relatively constant value. To determine the reason for this difference, the electron density distribution (EDD) is determined from high-pressure single-crystal x-ray diffraction data by the maximum entropy method. The EDD results show that the chemical bond properties in LaB6 play a key role also investigated by single-crystal x-ray diffraction. In observed from ambient pressure to 39.1 GPa. The structural stability of LaB6 under high pressure is this study, no structural or electronic phase transition is 展开更多
关键词 CASTEP EDD 110 MEM LaB6 work Function and Structural Stability under High Pressure
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Rapid excavation with a newly developed retaining system: Spiral assembly steel structure
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作者 关成立 杨宇友 王成彪 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第7期2719-2729,共11页
The spiral assembly steel structure, a newly developed retaining wall for the rapid excavation of small-sized foundation pits in unsaturated soil, is presented. This new type of retaining structure is prefabricated in... The spiral assembly steel structure, a newly developed retaining wall for the rapid excavation of small-sized foundation pits in unsaturated soil, is presented. This new type of retaining structure is prefabricated in the factory and is assembled on site in the excavation of a pit. This retaining structure is composed of several prefabricated steel structural units, in which the adjacent steel structural units are joined with connectors. Each steel structural unit has one steel pipe in the radial direction and is welded to a single piece of steel plate. After full installation in situ, the retaining structure becomes a cylindrical steel structure. With the protection afforded by this new type of retaining structure, excavation work can be completed within 24 h to a depth up to 5 m. In order to verify the reliability and effectiveness of this new retaining structure, field construction tests were conducted in Beijing, China. The test construction was monitored. The monitoring program included measuring stress in the structure, lateral earth pressure, and lateral deformation of the surrounding soil. The monitoring data from the field test were compared with the theoretical results. The results show that the proposed new structure is reliable and effective. 展开更多
关键词 working shaft rapid excavation retaining structure field construction monitoring
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Practice of Project Management Methodology for Commercial Aero engines Based on Integrative Project Architectures 被引量:2
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作者 ZHANG Yujin LIAO Wenhe 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2020年第2期311-321,共11页
To collect and share information of projects or products and make it consistent and correct so that the quality and costs of projects can be effectively controlled,an integrative project architecture integrating diffe... To collect and share information of projects or products and make it consistent and correct so that the quality and costs of projects can be effectively controlled,an integrative project architecture integrating different types of breakdown structures is necessary.In this paper,the international research status on work breakdown structure(WBS)was analyzed,and an integrative project architecture for commercial aero-engines was designed,where product breakdown structure(PBS),WBS,organization breakdown structure(OBS)and cost breakdown structure(CBS)were integrated and built.And the architecture was applied in information systems.A transfer from technological views of complex products through their lifecycles to management views has been realized with this standardized architecture,thus development tasks and costs can be controlled. 展开更多
关键词 integrative project architecture commercial aero-engines work breakdown structure(WBS) product breakdown structure(PBS) organization breakdown structure(OBS) cost breakdown structure(CBS)
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PHOENIX’S FIRST NET-ZERO ENERGY OFFICE RETROFIT: A GREEN AND LEAN CASE STUDY
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作者 Akash Ladhad Kristen Parrish 《Journal of Green Building》 2013年第4期3-16,共14页
Many in the construction industry view lean practices as a means for reducing cost and schedule while maintaining or improving quality. This paper argues that lean practices can also be used to promote energy savings ... Many in the construction industry view lean practices as a means for reducing cost and schedule while maintaining or improving quality. This paper argues that lean practices can also be used to promote energy savings throughout a building’s life cycle. This paper presents a case study of an existing building retrofit in Phoenix, Arizona. The project owner, a general contractor, self-performed much of the building construction and worked to ensure the project team aligned around the project’s net-zero energy goal. All building systems, excepting the walls and roof, were re-designed and re-constructed. After retrofit, the building has achieved net-zero energy consumption;that is, the building produces as much energy as it consumes on an annual basis. Deep building energy retrofits typically result in larger energy savings than operational changes alone can provide, as these retrofits take a whole-building approach to design (i.e., optimize the whole) and implement integrated project delivery methods (e.g., (AIA, 2007)). This paper discusses a net-zero energy retrofit and how lessons learned on this project could apply to other deep energy retrofits for commercial buildings (where “deep” refers to energy savings of 25% or more) that may significantly improve building value (Miller and Pogue, 2009). The inefficiency of existing building stock supports the need for retrofitting: energy consumption in the existing building stock in the United States accounts for approximately 41% of the total primary energy consumption (US DOE, 2012). In order to reduce this consumption, existing buildings must be retrofit, through replacement or upgrade of their existing building systems, to improve their energy performance. Beyond the energy motivation, a building’s operating costs account for the largest portion of the life cycle cost. Thus, deep energy retrofit projects offer an opportunity to significantly reduce both national energy consumption and expenditures. While much research exists on the topic of energy retrofits, very little explores the role of the contractor. This paper explores the contractor’s role (rather than the designer’s or engineer’s role) in delivering deep energy retrofit projects. The contractor plays a critical role in delivering a project that meets the owner’s expectations and goals and satisfies the specifications (Ahn and Pearce, 2007). Namely, the contractor executes the plans and specifications, giving physical reality to the design team’s vision. In the case of deep energy retrofits, this role is particularly important, as installation and operation must conform to the design intent to achieve the predicted energy performance. Moreover, the contractor must understand the existing condition to effectively retrofit the building. This paper explores critical building energy efficiency measures and processes for achieving deep energy savings in retrofit projects. Specifically, we present the role of the contractor in a case study project in Phoenix, Arizona where the contractor was engaged in the project early in the design stage. This paper discusses the process of developing and selecting energy efficiency measures (EEMs). It explains the reasons for choosing particular EEMs, including a discussion of selecting an appropriate baseline for energy savings calculations, and documents the impact of EEMs on total energy consumption and design intent. The paper concludes with a discussion of recommendations that, if applied in part or whole, will increase the effectiveness of future construction teams in delivering deep energy retrofit projects. 展开更多
关键词 energy efficiency measures lean construction net-zero energy work structure retrofitting deep energy savings integration process collaboration
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