An extended total factor productivity method is developed for measuring the quality of economic growth (QEG). Specifically, criteria for judging the QEG are first elaborated using endogenous economic growth theory, and subsequently, an assessment index system for evaluating QEG is constructed. In this system, the production factors primarily include labor, material capital, education, medical and health, environmental resource, and social security, while the output indexes comprise the gross domestic product (GDP), employment rate, income gap, and environmental pollution. In the empirical study, the directional distance function and Global Malmquist-Luenberger index are implemented to examine the QEG in China from 2000 to 2016 by provinces, regions, and factor decomposition, respectively. The global scale technological change and global pure technological change are the main sources for improving the QEG. The results also reveal a considerable widespread inefficiency and uneven development of the QEG. In general, from the eastern to western to central regions, the QEG becomes noticeably lower; The investment level is not only a driving force for economic growth, but also a source for boosting the QEG. These findings will provide a reference for China in adjusting relevant investments, ameliorating environmental conditions, and accomplishing the unity of quantity, quality, and efficiency in economic growth.

The digital economy plays an important role in achieving the strategic goal of “carbon peaking and carbon neutrality” in China. In this study, we construct a system dynamics (SD) model to comprehensively analyze the impact of the digital economy on CO2 emission. First, we simulate and forecast the future baseline of the digital economy, energy consumption, and CO2 emission in China from 2005 to 2040. Second, we study the impact of the digital economy on CO2 emission based on scenario analysis of different digital economy growth rates. Finally, we study the influencing factors of CO2 emission reduction effect of the digital economy. The results indicate the following: (1) CO2 emission will peak in 2034. From 2020 to 2025, the cumulative reduction in energy consumption intensity will be 15.75% and the cumulative reduction in CO2 emission intensity will be 20.9%. Both indicators will reach the national goals during the 14th Five-Year Plan period. However, it will require more effort to realize the goal of the share of non-fossil energy. (2) There is an inverted U-shaped relationship between the digital economy and CO2 emission. The digital economy aggravates CO2 emission mainly by promoting energy consumption, but it reduces CO2 emission by promoting the upgrading of the energy consumption structure and reducing the energy consumption intensity. (3) The R&D investment intensity and the environment investment intensity can strengthen the CO2 emission reduction effect of the digital economy. The results will be crucial for carbon reduction and provide policymakers with suggestions for sustainability.

(1) Background: with the emergence and continuous development of more multinational corporations, capital and resources flow rapidly in the form of global supply chains around the world. Furthermore, government subsidies for R&D are one of the key factors that affect foreign-funded R&D activities and their innovation output and performance in global supply chains. (2) Methods: in this paper, firstly, based on two sets of time series and dynamic panel data, we propose a distribution time lag model to test the effect of R&D subsidy policies from the macro perspective. Secondly, we employ the propensity score matching method to test the micro effect of R&D subsidy policies. (3) Results: our empirical results show that there are significant differences in the impacts of R&D subsidy policies on foreign capital funded innovation and domestic innovation. The main effect of government subsidy on foreign capital R&D is to improve the innovation output. However, regarding domestic R&D, it is to promote innovation performance. (4) Conclusions: Government subsidy is the main cause of the individual differences among the foreign funded R&D institutions in terms of innovation output and innovation performance. From the perspective of global supply chains, our analysis and results provide managerial and policy insights on subsidizing foreign investment in R&D in China.

To improve the detection efficiency and safety of the tractor, the research proposed a device for detecting the loading–lifting performance of the lower link of the tractor based on the four-bar mechanism. According to the actual use requirements and the testing standards, the critical components in the device were designed. The dynamic analysis of the load-lifting device was carried out by dynamic simulation, and the component strength in the machine was checked by the finite element simulation method. The results showed that the designed device could realize the hooking and connection of the lower link without an artificial method. The average cost of the device was 5.13 s to realize the connection with the lower link, and it took 7.30 s to raise the lower hitch point to a set height, about 750 mm. The loading test showed that the device could keep the loading force of the lower link stable during the lifting process. The designed device could shorten the detection time of the tractor hydraulic linkage and improve the cost, safety, and efficiency of detection. The research could provide a reference for the design of hydraulic linkage detection devices for the large-medium horsepower tractors and help realize the intelligent detection of tractors.

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