钢铁行业资源—环境—经济系统耦合协调分析

耦合协调发展水平的测度对于钢铁行业可持续发展问题的研究具有重要意义。文章将耦合协调度应用到钢铁行业,首先构建资源—环境—经济(REE)系统耦合协调度评价指标体系,利用加权TOPSIS法计算中国钢铁行业2000-2018年资源-环境-经济系统以及各子系统的评价值,然后采用耦合协调度发展模型对资源－环境—经济系统的耦合协调发展水平进行分析。结果表明：钢铁行业资源—环境—经济系统综合评价值呈现平稳—上升—平稳的发展趋势,耦合协调度经历了从勉强协调到良好协调的过渡,耦合协调状态不断改善。     

Energy-saving generation dispatch toward a sustainable electric power industry in China

Energy shortages, climate change and environmental pollution are critical issues that the entire world is faced with currently. To tackle the challenge and realize sustainable development, the Chinese government launched the Energy-Saving Generation Dispatch (ESGD) in 2007. In the ESGD scheme, generating units are dispatched based on fuel consumption rates and pollutant emission intensities from low to high. However, annual generation quotas still widely exist. With the mandatory shutdown of small-capacity and low-efficiency thermal generating units in 2006–2010, most of the currently running thermal generating units are large-capacity and highly efficient units. The additional improvement of the overall energy efficiency under this situation is a key problem for the Chinese electric power industry. To this end, a new type of ESGD framework is designed in this paper. Sequential coordination among yearly, monthly, day-ahead and real-time generation schedules is proposed. Based on the framework, the corresponding models are formulated. Empirical analysis is conducted using the realistic data obtained from the Guangdong Power Grid Corporation. Four generation dispatch modes are compared. The results indicate that the proposed ESGD mode can further reduce energy consumption and pollutant emissions. Hopefully, this paper can provide a valuable reference for policy making in the Chinese power sector.     

Materials Design of Solar Cell Absorbers Beyond Perovskites and Conventional Semiconductors via Combining Tetrahedral and Octahedral Coordination

Tetrahedral coordination structures, e.g. crystalline Si, GaAs, CdTe, and octahedral coordination structures, e.g. perovskites, represent two classes of successful crystal structures hitherto for solar cell absorbers. Here, via first‐principles calculations and crystal symmetry analysis, the two classes of semiconductors are shown exhibiting complementary properties in terms of bond covalency/ionicity, optical property, defect tolerance, and stability, which are correlated with their respective coordination number. Therefore, a spinel structure is proposed, which combines tetrahedral and octahedral coordination into a single crystal structure, as an alternative to perovskite and conventional semiconductors for potential photovoltaic applications. The case studies of a class of 105 spinel AB₂X₄ systems identify five spinel compounds HgAl₂Se₄, HgIn₂S₄, CdIn₂Se₄, HgSc₂S₄, and HgY₂S₄ as promising solar cell absorbers. In particular, HgAl₂Se₄ has suitable bandgap (1.36 eV by GW0 calculation), small direct–indirect bandgap difference (24 meV), appropriate carrier effective mass (m_e = 0.08 m₀, and m_h = 0.69 m₀), strong optical absorption, and high dynamic stability. This study suggests that crystal systems with mixed tetrahedral and octahedral coordination may open a viable route for emerging solar cell absorbers.     

突发事件下三级供应链联合契约协调

突发事件会对基于随机需求的市场产生巨大的波动，造成供应链系统的不稳定，打破原有的协调。为此，构建了突发事件下供应链协调的应对策略，建立了收益共享-两部收费（RS-TT）联合契约。研究表明：突发事件前，联合契约可以实现供应链的协调；突发事件后，原契约不会起协调作用。因此，对原契约及契约参数进行改进，并通过算例分析验证了改进后的契约可以使供应链达到全局最优的状态且具有抗突发事件性。     

国土空间规划体系的海洋管理及规划发展研究

海洋空间规划作为一种基于生态系统的多用途海洋管理方法和技术手段，也是解决现代社会经济发展中人类行为活动与海洋生态环境保护之间冲突的有效工具。以国土空间规划体系改革和自然资源统一管理为背景，讨论了全要素空间规划体系下的陆海统筹要求，同时对国内外海洋管理及规划研究成果进行综述分析，并结合深圳市海岸带规划编制内容总结了陆海一体化的海洋管理和空间规划优秀经验，从整合海洋空间规划体系、搭建综合管理平台、健全实施监管机制等方面提出了海洋规划管理的框架思路，对未来陆海统筹的海洋空间规划做出发展构想。     

特高压直流输电系统换流站的优化设计(英文)

Based on the consultation and study for Xiangjiaba-Shanghai ±800 kV UHVDC(ultra high voltage direct current) project,this paper presents an optimal design for key technique solutions.In this paper,the DC system electrical scheme design,the DC filter design,the DC harmonic component suppression,the over voltage and insulation coordination,the requirements for converter station equipment,the main equipment technical parameters of equipment(including thyristor valve,converter transformer,smoothing reactor,DC breaker),the configuration of measuring device and DC control protection system,and the de-icing operation design are investigated.According to the UHVDC technology researched conclusions and the development of the project construction,the UHVDC system design for converter stations becomes an optimal combination.The optimized design solves numbers of technical problems of the world’s first UHVDC project,and it is applied to the project’s construction.Under the actual operating condition,the optimized design is proved to be correct and superior.These optimal design conclusions are impartment for developing UHVDC technique and equipment,and provide reference for future UHVDC projects.     

Enhanced frontier-based exploration for indoor environment with multiple robots

In this paper, the exploration and map-building of unknown environment by a team of mobile robots is intensively investigated. A new exploration technique is proposed to increase the exploration efficiency. In particular, the new technique has two main objectives: firstly, it aims at reducing the exploration time and the traveled distance by reducing the overlap which takes place when a certain area in the environment is explored by more than one robot. To achieve this, a new procedure to assign the next target location for each individual robot is proposed. And secondly, it aims at reducing computations complexity required by target selection and path planning tasks. More importantly, the proposed technique obviates the need for environment segmentation complex procedures which is adopted in some previous important research works. The new technique is intensively tested with different environments. The results showed the effectiveness of the proposed technique.     

Optimal channel coordination in use-based product-service system contracts

Nowadays, service economy efficiencies are key to keep competitiveness and increase market advantages. The development of Product-Service Systems (PSS) can be an interesting strategy as they seek to improve the business performance of all the participants in the value chain. This paper proposes a novel reliability-based reward scheme for use-oriented PSS contracts. In a PSS instead of paying for the product, the client pays a fee for its performance. The contribution of this work to the existing literature is to provide a quantitative tool for the development of a use-oriented PSS contract based on non-repairable component reliability and risk sharing. It can be extended to other performance metrics such as availability and reliability. A well designed PSS achieves a mutual growth agreement for the client and the supplier if it aligns their interests through channel coordination. This is achieved by balancing the improvement in the expected cost and profit for the client and the supplier, respectively. The improvement is measured with respect to a baseline scenario where no PSS contract exists. The methodology is tested using a case study that analyses mining haul truck tires. The results show a significant overall improvement in the main key performance indicators and environmental impact of the value chain.     

Adjustable Robust Optimisation approach to optimise discounts for multi-period supply chain coordination under demand uncertainty

In this research, a problem of supply chain coordination with discounts under demand uncertainty is studied. To solve the problem, an Affinely Adjustable Robust Optimisation model is developed. At the time when decisions about order periods, ordering quantities and discounts to offer are made, only a forecasted value of demand is available to a decision-maker. The proposed model produces a discount schedule, which is robust against the demand uncertainty. The model is also able to utilise the information about the realised demand from the previous periods in order to make decisions for future stages in an adjustable way. We consider both box and budget uncertainty sets. Computational results show the necessity of accounting for uncertainty, as the total costs of the nominal solution increase significantly even when only a small percentage of uncertainty is in place. It is testified that the affinely adjustable model produces solutions, which perform significantly better than the nominal solutions, not only on average, but also in the worst case. The trade-off between reduction of the conservatism of the model and the uncertainty protection is investigated as well.