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Large-scale infrastructure projects have important strategic positions in economy and social development, especially in developing countries, and are growing constantly larger and more complex. During the life cycle of a large-scale infrastructure project, technological problems and environmental and socio-economic impacts drive relevant scientific research. However, few empirical studies have been conducted to examine the interaction between project and research. In this paper, we use the Three Gorges Project (TGP), which is the world's largest hydropower project, as a case study to find the patterns of scientific research on specific large-scale infrastructure projects. Text mining and other quantitative methods have been used to reveal: (1) the growth of the publication outputs of the TGP relevant research, (2) major research topics and their temporal trends and (3) the effects of language and corresponding author's nationality on topic proportions in papers. We find that topics of engineering issues were discussed more in domestic journals and in earlier stage of the project's life cycle. Meanwhile, topics of environmental issues were discussed more in international journals and became increasingly popular during the life cycle of the project. These findings are useful for policy-makers and project managers to better establish collaborations with the academia and to more properly allocate resources in future project management practices. [ABSTRACT FROM AUTHOR]

The rich hydro resources and global pressures of greenhouse gas emission have promoted the rapid development of hydropower projects in China. However, the benefit distribution unfairness in hydropower projects leads to problems such as resettlement conflicts, which significantly hinder the sustainable development of hydro resources. In order to determine a reasonable benefit sharing policy system, this study employs a new perspective, which treats the reservoir migrants as a formal project stakeholder rather than the passive “compensation receivers” previous practices have considered them to be. From this perspective, this study 1) identifies the stakeholders of hydropower projects and their input/output factors based on stakeholder theories, and highlights the four most important core stakeholders, i.e., government, hydropower generation enterprises, reservoir migrants, and power grid enterprises; 2) designs a specific calculation method for the four core project stakeholders’ cash flows and establishes a quantitative benefit-sharing model based on the input-output analysis; and 3) employs the Xiluodu Project in China as a case study to demonstrate the feasibility and effectiveness of the proposed method. Theoretically, the change in reservoir migrants’ status in the project delivery framework provides a new perspective for benefit sharing and resettlement studies. Practically, this study establishes a feasible quantitative tool for the description and assessment of benefit sharing systems, and the overall assessment of hydropower projects. The results of the case study show that, under the current benefit distribution policy of China, yields of reservoir migrants are significantly lower than those of other core stakeholders. The results also indicate that, by increasing resettlement compensation standards and slightly adjusting the electricity generation price, all core stakeholders’ yields can reach a more rational and fair level. [ABSTRACT FROM AUTHOR]

Bias voltage has great influence on the microstructure and properties of multilayer coatings, but it is endowed less attentions compared with modulation periods. In this work, effects of bias voltage ranging from −120 V to −210 V on the microstructure and properties of the AlCrN/AlTiN multilayer coatings are investigated. Results show that the multilayer coatings possess fcc-(Al,Cr,Ti)N singular phase, and grow preferentially along the (111) plane, but the texture coefficient of the (111) plane drops greatly at −210 V. Surface roughness decreases firstly and then increases with the bias voltage. Conversely, the hardness increases gradually to the maximum value 33.0 GPa at −180 V, and then decreases to 26.4 GPa at −210 V caused by the texture variation and coarse structure. The adhesion strength decreases gradually with the bias voltage due to augmented residual stress. The friction coefficient and wear rate drop firstly and then increase at −210 V. Abrasion, oxidation and adhesion wear are primarily responsible for the failure of the coatings at mediate bias voltage, while spallation accelerates the failure of the coatings at −120 V and −210 V caused by their poor microstructure and mechanical property. • AlCrN/AlTiN coatings possess fcc-(Al,Cr,Ti)N phase at various bias voltage. • Texture coefficient of (111) plane drops greatly at −210 V. • Adhesion strength decreases with bias voltage due to increased residual stress. • Hardness rises and then declines with bias voltage, with wear rate varying inversely. • Coating at −150 V with lowest wear rate fails by abrasion, oxidation and adhesion. [ABSTRACT FROM AUTHOR]

Microstructure and hot corrosion resistance of four aluminide coatings with different Si contents ranging from 0 at % to 30 at% are studied. Si primarily exists as CrSi 2 and (Cr,Ti) 5 Si 3 in the upper zone of Si-modified aluminide coatings; CrSi 2 transforms into Cr 3 Si phase during corrosion process. These silicides hinder the inward diffusion of the corrosive elements, resulting in enhanced corrosion resistance of Si-modified aluminide coatings at 700 °C. Mechanisms of severe corrosion in coatings with Si at 900 °C was disclosed; high content of Si leads to insufficient Al to renovate Al 2 O 3 scale, as well as high temperature causes fast depletion of Al. • Si modified aluminide coatings with various Si contents were prepared. • Lamellar CrSi 2 and (Cr,Ti) 5 Si 3 phases are formed in the upper zone of the coatings. • Addition of Si increases corrosion resistance of the aluminide coating at 700 °C. • For the lamellar silicide hinder the inward diffusion of corrosive elements. • Si decreases corrosion resistance at 900 °C for lowering Al content in the coating. [ABSTRACT FROM AUTHOR]

AlCrN coatings have been studied extensively by arc ion plating or magnetron sputtering, while there are scarce reports on the AlCrN coatings prepared by a hybrid technology of arc ion plating and magnetron sputtering. In this paper, five AlCrN coatings were prepared by the hybrid technology under bias voltages from −40 V to −200 V. XRD, SEM, TEM and nano-indenter etc. were used to study the microstructure and properties of the coatings. Results show that all the five coatings possess fcc-(Al,Cr)N phase with preferential orientation of (111) crystal plane. With higher bias voltage, the quantity of micro-particles decreases and the coating's surface quality is improved. Compressive stress, hardness and elastic modulus of the AlCrN coatings increase firstly and then decrease. The AlCrN coating with bias voltage of −160 V possesses the highest hardness about 33.2 GPa and lowest wear rate about 1.47 × 10−6 mm3/N‧m. The cutting time of the AlCrN coated cutter deposited at −160 V is 2.4 times longer than that of the uncoated milling cutter, with H13 die steel as work-piece. The AlCrN coated cutter fails mainly due to abrasive and adhesive wear. In addition, oxidation and inter-diffusion between substrate/coating/workpiece also occur in the cutting zone. • Five AlCrN coatings are deposited by a hybrid technology under various bias voltages. • Surface quality and mechanical properties are enhanced by the hybrid technology. • The coating deposited at −160 V possesses the highest hardness and wear resistance. • Cutting time of AlCrN coated cutter is 2.4 times longer than that of the bare cutter. • AlCrN coated cutter fails mainly due to abrasive and adhesive wear. [ABSTRACT FROM AUTHOR]

The completion of Shuibuya, the last hydropower station to be constructed in the Qingjiang cascade, signifies China's successful development of the world's largest mixed cascade hydropower generation system. Joint operation of such cascaded hydropower stations is considered necessary to improve hydropower output in China. In this study, two modeling methods – routine and optimal operations – were adopted, based on existing rules of reservoir operation, to determine the effects of joint operation. To investigate the realistic and potential effects, the two models were computed using observed runoff data (1951–2009). The potential effects were identified by comparing the total hydropower generation two single cascades and their cogeneration. Under the routine operational mode, the incremental power generation of joint operation would be 5.73 × 10 8 kWh, an increase of 5‰ compared to isolated operation. However, even in isolation, if reservoir operation is optimized through the dynamic programming algorithm, the incremental power generation of the cascade would be 42.24 × 10 8 kWh, which is seven times that of joint operation with routine reservoir operation (5.73 × 10 8 kWh). The results showed that, under current reservoir operating rules, there is little room for improvement in hydropower generation, although joint operation could increase hydropower generation to a certain extent, especially in the reservoirs' refill and release stages. China must amend its existing operational mode for reservoirs to enhance the economic benefits of cascade hydropower stations. Furthermore, to meet increasing demands for both water and energy, carefully considered planning of constructing clusters of these stations is required. [ABSTRACT FROM AUTHOR]

Rock spalling is one of the most frequent break modes and a serious stability challenge for the supporting design during engineering excavation under high geo-stress and hard rock conditions. The primary objective of this work was the field investigation and experimental testing of basalt spalling in more than 50 cases in a large underground cavern in China. The field characteristics of basalt spalling, including the spatial distribution of events, its micro-surface morphology, the joint effect, the time-dependent relation to the excavation, the spatial distance to the opening face, and the supporting condition, are first presented via detailed statistical investigation. An in situ study of the full spalling process, including the surface development of rock slabbing and inner cracking extension of the surrounding rock, was recorded in a time series via a borehole camera, displacement measurement, and in situ photos. These experimental results exposed the time-dependent development of surface spalling performance and the inner cracking evolution of rock mass ahead of spalling. All of these actual spalling cases in a large underground cavern and the corresponding statistical analysis provided meaningful evidence for the tensile failure mechanism and prevention measures for rock spalling. [ABSTRACT FROM AUTHOR]