Differences in Instruction Efficacy Between On-Campus and Online Teaching

The study, published in China Higher Education Research, takes 1630 undergraduates enrolled in 2019 and 2020 in University X as analysis sample. It conducts an empirical analysis of differences in instruction efficacy between on-campus and online teaching from the perspectives of class interaction, teaching atmosphere and student characteristics, and examines the influencing mechanism of online teaching efficacy. The propensity score matching method (PSM) is employed to analyze the differences in instruction efficacy and the degree of difference. In addition, the Poisson regression model is used to examine the factors influencing online teaching efficacy

Classification-based forest management program and farmers' income : evidence from collective forest area in southern China

Purpose This article's purpose is to examine the effect of a Classification-Based Forest Management (CFM) program on farmers' income and determine whether its effect varies with the degree of farmers' concurrent occupations. Design/methodology/approach The authors use representative panel survey data from Longquan to explore the welfare effects of CFM on farmers. The analysis uses differences-in-differences with propensity score matching (PSM-DID) estimation techniques to deal with endogeneity problems when farmers make the decision to participate in CFM. Findings The results show that CFM has a positive effect on part-time forestry households (where forestry income accounts for between 5 and 50% of total income). In contrast, it has a negative impact on full-time forestry households (forestry income accounts for more than 50%), and no clear effect on nonforestry households whose forestry income is less than 5%. This research also shows that the positive effect of CFM on farmers' total income is mainly due to increase of off-farm income driven by CFM, while the negative effects consist of CFM's reduction of forestry income. Originality/value The extent of CFM's economic benefits to farmers is uncertain and largely unexplored. This paper analyzes the impact of CFM on income structure to explore the mechanisms explaining its effects on farmers' income. There are still challenges in ensuring the reliability and accuracy of CFM assessment. This paper collected natural experimental data and used the estimation technology of PSM-DID to solve the possible endogeneity problems.Peer reviewe

Optimization and Numerical Simulation of Multi-layer Microchannel Heat Sink

AbstractThe configuration sizes of multi-layer microchannel heat sink is optimized in order to enhance the performance of the high flux chip, which is 556W/cm2. Taking the thermal resistance and the pressure drop as goal functions, a double-objective optimization model was proposed based on the thermal resistance network model. The opimized microchannel heat sink is numerically simulated by computational fluid dynamics (CFD) software. The number of microchannel in width n1 and that in height n2 are 24 and 2, the width of optimized optimized microchannel and fin are 196 and 50μm, respectively, and the corresponding total thermal resistance of the whole microchannel heat sink is 0.4025°C/W. The highest temperature is less than 98°C, which can satisfy the requirement of chip to temperature. The maximum temperature difference is 77.8673°C, and the transferred power of heat flux is 200W, so the total thermal resistance is 0.3893°C/W, which agrees well with the analysis result of thermal resistance network model

Study on the Cooling Capacity of Different Quenchant

AbstractHeat treatment is one method to improve mechanical properties of metal, but each heat treatment method has its advantages and disadvantages, therefore, different requirements regarding size, shape, and properties with respect to different heat treatment processes should be considered. The traditional liquid quenchant are clear water and quench oil. Gas quenching is a relatively new process with several important advantages, such as minimal environmental impact, clean products, and ability to control the cooling locally and temporally for best product properties. To meet the high cooling rates required for quenching, the cooling gas must flow at very high velocities, but still the cooling capacity of gas is weakness. In order to increase the cooling capacity of gas, the spray water is added during gas quenching. In this paper, the GCr15 steel is as the research object, the cooling capacity of clear water, quench oil, nitrogen and nitrogen-spray water are studied through comparison of temperature difference and cooling velocity of the specimen

China’s Climate Change Policy Attention and Forestry Carbon Sequestration Growth

Forest carbon sinks play an important role in climate change mitigation and adaptation. The Chinese government has demonstrated its proactive approach to addressing climate change by setting development targets for low-carbon transformation and making solemn commitments to peak carbon emissions before 2030 and to achieve carbon neutrality by 2060. In this article, the Chinese Government’s Work Reports and Five-Year Plans are used to construct an index named China’s Climate Change Policy Attention (CCPA), which reflects the government’s emphasis on climate change and forestry in China. This article aims to examine the impact of CCPA, the adjusted Climate Policy Uncertainty (CPU) index from the U.S., and the Economic Policy Uncertainty (EPU) index from China on the Chinese forest carbon stocks (FCS) comprehensively. On this basis, we are interested in clarifying the channels by which CCPA promotes the growth of forest carbon sequestration in China. Specifically, panel data from 30 provinces in China from 2000 to 2017 are used for empirical analysis, and the following results are obtained: (1) The baseline regression indicates that CCPA significantly promotes the growth of FCS, while CPU or EPU inhibits its growth. (2) The interactive regression shows that the effect of CCPA on the growth of FCS can mitigate the inhibiting impact of CPU or EPU. (3) Mediation analysis documents that CCPA promotes FCS growth by increasing the forest tending area, expanding the existing forest area, increasing renewable energy consumption, and improving green investment. (4) Heterogeneity analysis reveals a clear differentiation in the effect of CCPA on FCS under different situations. Finally, policy implications are proposed based on the results. This article is expected to provide a theoretical basis for the Chinese government to develop relevant policies from the perspective of promoting FCS growth

Study on Consumers’ Purchase Intentions for Carbon-Labeled Products

The carbon-labeling system is able to quantify the level of greenhouse gas emissions of goods throughout their life cycle, including production, delivery, and consumption. With the proposal of carbon peak and carbon neutrality goals, the carbon-labeling system has an inevitable impact on production by companies and the purchase behavior of consumers. This paper constructs a theoretical model of the influencing mechanism on consumer willingness to purchase carbon-labeled products by utilizing the theory of consumption values. Through a survey and analysis of a sample of 347 Chinese university students, a regression analysis is applied to explore their willingness to consume carbon-labeled products and the corresponding influencing factors. The results show that (1) despite relatively low public awareness of the carbon-labeling system, the willingness to purchase carbon-labeled products is strong; (2) functional value, emotional value, and epistemic value can positively influence customer willingness to purchase carbon-labelled products; and (3) there is a significant difference in the willingness to purchase carbon-labelled products in terms of age and no significant difference in terms of gender, income, occupation, and education level. Based on the findings, some recommendations are made to help companies adopt appropriate strategies to trigger consumers’ purchase intentions and gain a market advantage in carbon-labeling scenarios

The Dynamic Impacts of the COVID-19 Pandemic on Log Prices in China: An Analysis Based on the TVP-VAR Model

China’s wood industry is vulnerable to the COVID-19 pandemic since wood raw materials and sales of products are dependent on the international market. This study seeks to explore the speed of log price recovery under different control measures, and to perhaps find a better way to respond to the pandemic. With the daily data, we utilized the time-varying parameter autoregressive (TVP-VAR) model, which can incorporate structural changes in emergencies into the model through time-varying parameters, to estimate the dynamic impact of the pandemic on log prices at different time points. We found that the impact of the pandemic on oil prices and Renminbi exchange rate is synchronized with the severity of the pandemic, and the ascending in the exchange rate would lead to an increase in log prices, while oil prices would not. Moreover, the impulse response in June converged faster than in February 2020. Thus, partial quarantine is effective. However, the pandemic’s impact on log prices is not consistent with changes of the pandemic. After the pandemic eased in June 2020, the impact of the pandemic on log prices remained increasing. This means that the COVID-19 pandemic has long-term influences on the wood industry, and the work resumption was not smooth, thus the imbalance between supply and demand should be resolved as soon as possible. Therefore, it is necessary to promote the development of the domestic wood market and realize a “dual circulation” strategy as the pandemic becomes a “new normal”