Search

The deep sea fuels the world’s largest ecosystem, and a deep knowledge of its relevant evolutionary patterns can support the sustainable development of human society. It is difficult to carry out in-situ experiments under the extreme environmental conditions in the deep sea, which puts forward harsh requirements for the development of deep-sea scientific experiment equipment.This study summarizes the development status and problems regarding deep-sea scientific experiment equipment in China and abroad from the aspects of deep-sea test equipment and test sites, deep-sea in-situ exploration and experiment equipment, and experimental equipment for deep-sea environment simulation. China has independently developed a serial of equipment and technologies in the field of deep-sea scientific experiment equipment, and some of its advantageous directions have reached the international advanced level, which has promoted the progress of deep-sea scientific research. However, the country fails to build a mature industrial chain in terms of sophisticated equipment and associated key technologies, resulting in the restricted development of some equipment and prominent technological weaknesses. Therefore, we propose the following suggestions to promote deep-sea scientific research and the high-quality development of the deep-sea scientific experiment equipment: (1) strengthening top-level planning to coordinate technical research; (2) establishing incentive mechanisms to encourage innovation transformation; (3) building demonstration platforms and forming a standards system; (4) developing sensing technologies and accelerating the localization process; and (5)strengthening international cooperation to enhance innovation capacities.

In implementing the PMC model, trusting relationships between owners and PMC contractors is the key to resolving the dilemmas caused by institutional constraints and conventional thinking, such as frequent organizational conflicts, low management efficiency, and higher transaction costs. This study utilized PMC projects in Guangxi, Jiangsu, Zhejiang, Tibet, and Guizhou as analysis samples and employed semi-structured field interviews to investigate the antecedents of trust between owners and PMC contractors. In addition, questionnaires were used to quantify the mechanism of trust formation between the two parties and the influence of trust on project performance. The findings indicated that the managerial competence and reputation of the PMC contractor, the adequacy of the owner's authorization, and the effectiveness of the owner's supervisory measures were the key drivers of calculative trust. The adequacy of the owner's authorization, the effectiveness of the owner's supervisory measures, and social similarity play the greatest roles in influencing relational trust. Calculative and relational trust significantly impact project performance, with relational trust having a slightly more substantial impact. This study can serve as a resource for enhancing the performance of PMC projects and achieving PMC project success.

The engineering general contracting mode is an advanced engineering transaction mode, and design optimization is one of the important driving forces for vigorously promoting the general contracting mode. The application proportion of the general contracting mode in infrastructure projects is not high, the number of successful projects is not large, and the implementation effect is not ideal. One of the main reasons is that the design optimization theory and practice of international standard general contracting projects cannot adapt to the general contracting projects in the Chinese context, making local general contracting projects face huge challenges such as low enthusiasm for design optimization from all parties and unsatisfactory design optimization effects. Therefore, under the premise of bounded rationality, when the owner adopts control methods of different intensities, an evolutionary game study on the selection of design optimization strategies between the design and construction parties is carried out, and stability control strategies are proposed through case experiments and simulations. The research results indicate the following: firstly, the design optimization of general contracting projects in the Chinese context is feasible, but it depends on the distribution ratio of benefits obtained from the design optimization. Compared with general civil construction general contracting projects, the design optimization allocation ratio of industrial construction general contracting projects is more significant; secondly, the mixed control method of strong control and weak control is the optimal choice for the owner of the general contracting project; and thirdly, there are multiple evolutionary stable points, and mechanism design or incentive measures should be used to guide owners to choose weak control strategies, while design and construction parties should choose their design optimization strategies. The research results provide a reference for owners to determine the proportion and scheme of design optimization allocation, and for construction parties to determine design optimization strategies. [ABSTRACT FROM AUTHOR]

Water environment governance of large rivers is an essential measurement of ecological protection in China. The effectiveness of governance depends highly on the fulfillment of strategic CSR (corporate social responsibility) of Chinese leading enterprises. However, the fulfillment of strategic CSR often brings economic burden to the leading enterprises and needs government compensation support. Therefore, this paper explores the impact of government compensation on the fulfillment of strategic CSR of Chinese leading enterprises by constructing a multi-stage portfolio model. The main results show that (1) the prerequisite for leading enterprises to fulfill strategic CSR is sufficient profits; (2) the increase in government compensation can significantly affect the proportion of strategic CSR fulfillment of leading enterprises; (3) only when the portfolio considers both strategic CSR and project benefits, can the leading enterprises obtain the highest economic returns and better fulfill strategic CSR. The results can provide policy reference for the government to stimulate the fulfillment of leading enterprises' strategic CSR and also give suggestions for the leading enterprises to alleviate the economic pressure brought by fulfilling strategic CSR. [ABSTRACT FROM AUTHOR]

Cold seeps are highly productive chemosynthetic ecosystems in the deep-sea environment. Although microbial communities affected by methane seepage have been extensively studied in sediments and seawater, there is a lack of investigation of prokaryotic communities at the surface sediments and bottom seawater. We revealed the effect of methane seepage on co-occurrence networks and ecological niches of prokaryotic communities at the surface sediments and bottom seawater in the Haima cold seep. The results showed that methane seepage could cause the migration of Mn and Ba from the surface sediments to the overlying seawater, altering the elemental distribution at seepage sites (IS) compared with non-seepage sites (NS). Principal component analysis (PCA) showed that methane seepage led to closer distances of bacterial communities between surface sediments and bottom seawater. Co-occurrence networks indicated that methane seepage led to more complex interconnections at the surface sediments and bottom seawater. In summary, methane seepage caused bacterial communities in the surface sediments and bottom seawater to become more abundant and structurally complex. This study provides a comprehensive comparison of microbial profiles at the surface sediments and bottom seawater of cold seeps in the South China Sea (SCS), illustrating the impact of seepage on bacterial community dynamics. [ABSTRACT FROM AUTHOR]

In Public–Private Partnership (PPP) projects, the structure of the Special Purpose Vehicle (SPV) significantly impacts the value enhancement of projects. This study conducted a quantitative analysis of value enhancement in green PPP projects under single- and Dual-Role entity models and examined existing SPV private party compositions. A quantitative model was developed to enhance the value in green PPP projects through a Dual-Role "investor–builder" entity approach, comparing it with the single-role entity model. The findings indicate that in the Dual-Role entity mode, the construction party demonstrates a greater willingness to effort, resulting in shorter construction timelines and improved economic benefits for the project company. The preferred equity range for private parties escalates with the total project investment and the extent of "political support". Nevertheless, a disproportionately high government stake in the equity is detrimental to the value enhancement in PPPs, and excessive government regulation and control should be avoided. This quantitative model serves as a decision-making criterion for selecting the SPV mode and provides an alternative approach for evaluating PPP project performance. [ABSTRACT FROM AUTHOR]

Through the sub-network construction and the application of critical path method, this paper analyzes the impact of work schedule delay on the schedule of contracted project itself, the success or contracted projects, other follow-up contracted projects, and the program on the basis of double-code network and related lemmas. Based on this, a penalty model of work schedule delay is constructed and a case study is carried out. The research results show that the penalty model of work schedule delay can effectively deal with the impact of work schedule delay on the whole program under the condition of multiple stakeholders. The research results of this paper are conducive to the real-time control of the schedule of various kinds of work, contracted projects, and the program, and lay a foundation for the improvement of FIDIC penalty conditions (8.7) of contract, the definition of responsibility division within and among contractors, and the analytic processing of claims for contracted projects.

Non-commercial resources provided by employers (NCRPE) are the imperative factor affecting the progress of engineering projects. However, the NCRPE with limited supply ability is rarely considered in the schedule optimization models in previous studies from the perspective of work. This paper analyzes the characteristics of the non-commercial single resource provided by employers (NCSRPE), the optimization principle, characteristics, and tasks. With the initial network, this paper researches the optimization model of the NCSRPE to minimize the supply capacity of the NCSRPE before the implementation and to reduce the actual demand of the NCSRPE to a level slightly below the supply capacity of the production system. NCSRPE optimization and re-optimization models are built based on this, and the Hybrid Particle Swarm Algorithm (HPSA) is used to solve the problem. The results show that the two models can effectively solve the optimization problem of program planning and adjustment under multiple independent stakeholders. Finally, resource balance before the implementation and the re-optimization of resource cutting during the implementation are carried out for artificial aggregate in Program X of the South-to-North Water Diversion Project (SNWDP) based on the HPSA. A reasonable and practical program planning and adjustment within different stakeholders can be obtained.

The water environment restoration project portfolio (WERP) selection is discussed in this paper. By complying with the analysis of the project's multidimensional property and operation mode, this paper develops the chance constraint and the management constraint of the WERP from the perspectives of public service and enterprise operation. In addition, the multi-objective mixed integer linear programming model is constructed by combining the expectation method and the fuzzy chance constraint programming method. The results demonstrate that: (1) Our proposed method successfully circumvents the occurrence of local objective optimization within a specific confidence interval, thereby achieving a balance between economic and water environment restoration objectives; (2) including fuzzy chance constraints in our proposed method significantly diminishes the risk of exceeding the WERP capacity, thereby ensuring the effectiveness of water environment restoration by adopting a market-based approach. However, further examination of the impact of various sub-projects in WERP is necessary, along with the integration of novel evolutionary algorithms to enhance the efficiency of our model. [ABSTRACT FROM AUTHOR]