Research on Technical Points of Installation and Construction of Mechanical and Electrical Engineering

With the rapid development of China's overall economy, the construction engineering industry is gradually improving. Architectural engineering is an important environment for people to live, and its quality and safety are directly related to people's life and property. The most important part of the construction project is the mechanical and electrical installation, to realize the cost control of the project is the key point of the project. This article mainly explains the mechanical and electrical installation engineering in building engineering, and introduces the installation and construction technology in mechanical and electrical installation engineering in detail, and analyzes the control difficulties. It provides an important reference for the management of mechanical and electrical installation technology in the future

Ferromagnetic Kitaev interaction and the origin of large magnetic anisotropy in α\alpha-RuCl3_3

$\alpha$-RuCl$_3$ is drawing much attention as a promising candidate Kitaev quantum spin liquid. However, despite intensive research efforts, controversy remains about the form of the basic interactions governing the physics of this material. Even the sign of the Kitaev interaction (the bond-dependent anisotropic interaction responsible for Kitaev physics) is still under debate, with conflicting results from theoretical and experimental studies. The significance of the symmetric off-diagonal exchange interaction (referred to as the $\Gamma$ term) is another contentious question. Here, we present resonant elastic x-ray scattering data that provides unambiguous experimental constraints to the two leading terms in the magnetic interaction Hamiltonian. We show that the Kitaev interaction ($K$) is ferromagnetic, and that the $\Gamma$ term is antiferromagnetic and comparable in size to the Kitaev interaction. Our findings also provide a natural explanation for the large anisotropy of the magnetic susceptibility in $\alpha$-RuCl$_3$ as arising from the large $\Gamma$ term. We therefore provide a crucial foundation for understanding the interactions underpinning the exotic magnetic behaviours observed in $\alpha$-RuCl$_3$.Comment: 5 pages, two-column, 3 figure

A Systematic Literature Review on Performance Evaluation of Power System From the Perspective of Sustainability

Sustainability is a comprehensive concept that integrates at least three dimensions of environment, economy and society. The power system is the primary source of greenhouse gas emissions, adversely impacting environmental sustainability. It also generates necessary energy supplies, which promote economic and social sustainable development. Based on the sustainability nature of power system, this study puts forward an improved methodology, namely “Planning-Searching-Screening-Reporting-Reflecting” (PSSRR Cycle) to review the literature systematically on power system performance evaluation from a sustainability perspective over the past 20 years, with the aim of describing the current state of the whole performance evaluation system including the evaluation framework, evaluation indicators and evaluation methods, and providing research suggestions for future research. This study finds in the current literature that the Triple Bottom Line theory is the most commonly used theoretical evaluation framework; environmental and economic sustainability indicators are more emphasized; the DEA and MCDM methods are the more common evaluation methods. This study presents some future research notes, including improving the Sustainable Balanced Scorecard as a sustainable performance evaluation framework, emphasizing more social sustainability indicators, and using a combination of existing evaluation methods to make performance evaluation more efficient and accurate

The Community Land Model version 5 : description of new features, benchmarking, and impact of forcing uncertainty

The Community Land Model (CLM) is the land component of the Community Earth System Model (CESM) and is used in several global and regional modeling systems. In this paper, we introduce model developments included in CLM version 5 (CLM5), which is the default land component for CESM2. We assess an ensemble of simulations, including prescribed and prognostic vegetation state, multiple forcing data sets, and CLM4, CLM4.5, and CLM5, against a range of metrics including from the International Land Model Benchmarking (ILAMBv2) package. CLM5 includes new and updated processes and parameterizations: (1) dynamic land units, (2) updated parameterizations and structure for hydrology and snow (spatially explicit soil depth, dry surface layer, revised groundwater scheme, revised canopy interception and canopy snow processes, updated fresh snow density, simple firn model, and Model for Scale Adaptive River Transport), (3) plant hydraulics and hydraulic redistribution, (4) revised nitrogen cycling (flexible leaf stoichiometry, leaf N optimization for photosynthesis, and carbon costs for plant nitrogen uptake), (5) global crop model with six crop types and time‐evolving irrigated areas and fertilization rates, (6) updated urban building energy, (7) carbon isotopes, and (8) updated stomatal physiology. New optional features include demographically structured dynamic vegetation model (Functionally Assembled Terrestrial Ecosystem Simulator), ozone damage to plants, and fire trace gas emissions coupling to the atmosphere. Conclusive establishment of improvement or degradation of individual variables or metrics is challenged by forcing uncertainty, parametric uncertainty, and model structural complexity, but the multivariate metrics presented here suggest a general broad improvement from CLM4 to CLM5

The Impact and Mechanism of Internal Informal Institutions on Green Innovation: Empirical Evidence from Chinese Listed Companies

Green innovation is a key driving force in promoting the development of a low-carbon economy and society. However, previous studies have not paid enough attention to the influence of internal informal institutions on green innovation. To address this issue, this study conducts empirical tests by using a sample of A-share listed firms in China from 2013 to 2020. This study investigates whether and how carbon management strategies, as an important part of the internal informal institutions, promote corporate green innovation. The results show that carbon management strategies have a significant and positive impact on both the quantity and quality of green innovation. In addition, emphasizing meeting the needs of stakeholders and focusing on research and development (R&D) investment can significantly enhance the positive impact of carbon management strategies on green innovation. Furthermore, at the market level, carbon management strategies significantly boost green innovation in firms with larger market shares, which is enhanced by meeting stakeholder demands. At the firm level, state-owned enterprises pay attention to the mechanisms of both stakeholders’ demands and R&D investment in driving green innovation. At the executive level, executive shareholding firms emphasize driving green innovation through R&D investment. Overall, these findings provide new evidence for the determinants of green innovation that have not been fully explored before through the perspective of internal informal institutions

Executives’ carbon cognition and corporate carbon performance: The mediating role of corporate low-carbon actions and the moderating role of firm size

Executives' carbon cognition (ECC) is an important driving factor for enterprises to achieve carbon performance (CP) through low-carbon actions, but the existing research has not explored the mechanism between them. Based on the data of 440 Chinese listed companies from 2012 to 2021, we used text mining method to construct the index of ECC, and obtained noteworthy results through regression analysis. The results indicated that ECC has a significant positive impact on corporate low-carbon actions (CLA); CLA has a significant positive impact on CP; CLA plays a mediating role in the relationship between ECC and CP; in addition, firm size negatively moderates the positive impact of ECC on CLA; firm size negatively moderates the mediating effect of CLA on the relationship between ECC and CP. The research conclusions deepen the understanding of the relationship between ECC and CP in the context of carbon neutrality era, and provide theoretical guidance for guiding companies to actively implement low-carbon actions. At the same time, this study introduces the text mining method into the research of ECC, which provides a reference for future research in this field