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Climate engineering management (CEM) as an emerging and cross-disciplinary subject gradually draws the attention to researchers. This paper aims to focus on economic and social impacts on the technologies of climate engineering themselves. However, very few research concentrates on the management of climate engineering. Furthermore, scientific knowledge and a unified system of CEM are limited.

In this paper, the concept of CEM and its characteristics are proposed and elaborated. In addition, the framework of CEM is established based on management objectives, management processes and supporting theory and technology of management. Moreover, a multi-agent synergistic theory of CEM is put forward to guide efficient management of climate engineering, which is composed of time synergy, space synergy, and factor synergy. This theory is suitable for solving all problems encountered in the management of various climate engineering rather than a specific climate engineering. Specifically, the proposed CEM system aims to mitigate the impact of climate change via refining and summarizing the interrelationship of each component.

Overall, the six research frontiers and hotspots in the field of CEM are explored based on the current status of research.

In terms of the objectives listed above, this paper seeks to provide a reference for formulating the standards and norms in the management of various climate engineering, as well as contribute to policy implementation and efficient management.

Prior studies on virtual product purchase have focused on external technological factor but have paid less attention to internal user factors. Thus, drawing upon the social presence and user engagement theories, the purpose of this paper is to develop a research model considering both technological factors and user factors and empirically examine the validity of the proposed research model.

A survey from 214 World of Warcraft players was conducted to test the proposed research model, and structural equation modelling approach (specifically, PLS) was used to test the proposed hypotheses.

The data analysis results suggest that both social presence and user engagement positively influence the intention to purchase virtual products. Furthermore, two technological factors, interactivity and sociability, are found to affect social presence, and two social factors, social ties and social identity, are found to affect user engagement.

This study proposes a dual factor framework (i.e. technological and user factors) to investigate the factors influencing the intention to purchase by integrating the social presence perspective and user engagement perspective. The findings would be beneficial for service provider of massively multiplayer online role-playing games to recognize that triggering user demand is of equal importance with offering better technologies and suggest new ways to promote users’ virtual product purchase intentions.

The purpose of this study is to prepare new Fe-Cr-B alloys which have better wear resistance and investigate the wear mechanisms of these alloys tribotesting against SiC ceramic balls under dry sliding process.

Fe-Cr matrix alloys were fabricated using powder metallurgy route. The tribological behaviors of Fe-Cr alloys tribotesting against SiC ceramic balls using a ball-on-disc tribotester were studied at different testing conditions. Meanwhile, microstructure, phases and morphology of worn surfaces were investigated.

The element boron improved mechanical properties and tribological behavior of alloys. The friction coefficients of Fe-Cr matrix alloys did not show obvious difference. The specific wear rates of alloys decreased and then increased because of the brittleness of alloys with the increase of boron content. Fe-21 weight per cent Cr-7 weight per cent B alloy showed the best tribological properties in dry sliding. The wear mechanism of Fe-Cr alloy was plastic deformation and abrasive wear. However, the Fe-Cr-B alloys showed fatigue spalling characteristics.

This paper reported a new, cheap and wear-resistant Fe matrix material to prepare mechanical parts in food and mining industrial fields.

Environmental degradation resulting from human activities may adversely affect human health in multiple ways. Until now, policies aimed at mitigating environmental problems such as climate change, environmental pollution and damage to biodiversity have failed to clearly identify and drive the potential benefits of these policies on health. The conducted study assesses and demonstrates how specific environmental policies and instruments influence perceived human health in order to ensure input for a data-driven decision process.

The study was conducted for the 2004–2020 period in European Union (EU) countries with the use of dynamic panel data modeling. Verification of specific policies' impact on dependent variables allows to indicate this their effectiveness and importance. As a result of the computed dynamic panel data models, it has been confirmed that a number of significant and meaningful relationships between the self-perceived health index and environmental variables can be identified.

There is a strong positive impact of environmental taxation on the health index, and the strength of this relationship causes effects to be observed in the very short term, even the following year. In addition, the development of renewable energy sources (RES) and the elimination of fossil fuels from the energy mix exert positive, although milder, effects on health. The reduction of ammonia emissions from agriculture and reducing noise pollution are other health-supporting factors that have been shown to be statistically valid. Results allow to identify the most efficient policies in the analyzed area in order to introduce those with the best results or a mix of such measures.

The results of the authors' research clearly indicate the health benefits of measures primarily aimed at improving environmental factors, such as environmental taxes in general. The authors have also discovered an unexpected negative impact of an increase in the share of energy taxes in total taxes on the health index. The presented study opens several possibilities for further investigation, especially in the context of the rapidly changing geopolitical environment and global efforts to respond to environmental and health challenges. The authors believe that the outcome of the authors' study may provide new arguments to policymakers pursuing solutions that are not always easily acceptable by the public.

The purpose is to present a sensorless control method by which high‐resolution rotor position information is estimated and used for phase‐advancing operation of a high‐speed permanent magnet (PM) brushless DC (BLDC) motor.

The proposed sensorless control approach uses hardware to observe the flux vector which is excited by rotor magnets. It can provide the rotor position which is the same as the phase angle of the observed flux vector.

High‐resolution rotor position signal of the BLDC motor for dynamic phase‐advancing control cannot be directly obtained from the conventional Hall‐effect sensors, or via the traditional back‐EMF‐based sensorless control strategies in which the back‐EMF may be even undetectable at high‐speed. The proposed rotor‐flux‐observer (RFO)‐based sensorless control method overcomes these problems, and meanwhile provides high‐resolution rotor position information for the phase‐advancing purpose.

The RFO‐based sensorless control is traditionally applied to PM brushless ac (BLAC) operations, where the motor voltage vector can be calculated from the inverter switching status. However, this is not readily applicable to a BLDC motor since the voltage of the floating phase cannot be calculated. Moreover, during high‐speed operation, the microprocessor may not be sufficiently fast to calculate the high‐resolution rotor position. Therefore, in this paper, it is proposed to use hardware to observe the rotor‐flux‐vector. The microprocessor only samples the vector's α‐ and β‐components and calculates the phase angle, hence, its burden is low. The proposed method is validated with a 1.8 kW 85,000 rpm BLDC motor system.

The purpose of this paper is to analyze specifications of the China’s foreign trade policy with Organization of the Petroleum Exporting Countries (OPEC) member countries.

The paper conducts three panel data estimations (fixed effect [FE], random effect [RE] and fully modified ordinary least squares [FMOLS]) based on the gravity model approach for bilateral trade patterns in natural resource and non-natural resource commodities between China and 13 OPEC members over the period of 1998-2014.

The findings reveal that the gravity equation fits the data reasonably well. The existence of long-term relationships between the bilateral trade flows and the main components of gravity model – GDP, income (GDP per capita), the difference in income, exchange rate, the openness level, distance and WTO membership – through the FE, RE and the FMOLS approaches was confirmed. The estimation results show that the trade pattern between China and OPEC member countries relies on the Heckscher–Ohlin theory, thus being explained by difference in factor endowments such as energy resources and technology.

To the best of the authors’ knowledge, this is the first attempt to examine the China’s foreign trade policy with the OPEC member countries through a gravity trade approach.

This purpose of this paper is to explore China’s choice to focus early Belt and Road Initiative (BRI) Africa outreach on Eastern Africa. The BRI specifically seeks to achieve ten economic and policy objectives, as outlined in the two launch speeches of 2013. In terms of realising these, the economic development and digitisation levels, that progress of the demographic transition, and the important security context of the sub-region, logically make East Africa relatively important to BRI in continental context. Kenya specifically is important in being an African frontier therein, and, also, because it shares a few important borders with landlocked countries, including Ethiopia, Sudan and Uganda, alongside a strategic coast and ports. From this lens, as well the fact that in the Ming Dynasty Chinese fleets reached what is modern-day Kenya, China’s early BRI outreach to Africa having had a historical precedent in initially focusing on Eastern Africa, might be usefully understood.

To realise that aim a comprehensive survey of related literature and policy documents, in Chinese, English and Swahili, was undertaken and relevant data compiled and analysed.

To the best of the authors’ knowledge, first, this paper is the first to argue that the Belt and Road Initiative in Africa may build on abstract long-run logic in terms of economics, demographic change and security. This provides a contrary perspective to the pre-existing established “debt trap diplomacy” and no consistent logic narratives. Second, it is the first to offer a synthesised analysis of the BRI in Africa, East Africa specifically, looking across economic, demographic and security angles.

The paper is a synthesis of development and regional economics literature that forges some prospective rationales only. It is not an empirical research paper drawing very specific and definitive conclusions.

Amid widespread geo-economic tensions and uncertainty, around the Belt and Road Initiative in particular, this paper offers a new economic development-oriented logic for the choice of an important node of the China's Belt and Road Initiative, that of East Africa, Kenya especially. This may impact existing related narratives and policy responses.

Equivalently to the above this may then have an impact on the ground in East Africa and beyond.

The first such or even close to synthesis.