Under the dual carbon target regulation, this article constructs a collaborative research and development carbon reduction model for the photovoltaic industry supply chain from the perspective of carbon tax and consumer green preferences, using differential game theory. Considering three different scenarios of no research and development carbon reduction, independent research and development carbon reduction, and collaborative research and development carbon reduction, the optimal factors and profit values are obtained, and case analysis and sensitivity analysis are conducted. Research has found that: 1) The optimal carbon reduction achieved by photovoltaic industry supply chain entities through cooperative research and development is higher than that achieved through independent research and development. 2) The increase in carbon tax rates has to some extent increased carbon emissions, but at the same time reduced the overall profit of the photovoltaic industry chain. 3) The higher the proportion of research and development costs borne by photovoltaic system manufacturers, the higher the carbon emission reduction of photovoltaic silicon wafer suppliers' research and development. 4) Consumer green preferences are beneficial for increasing carbon emissions reduction in the photovoltaic industry chain.

Based on differential game theory, this article studies the competition and cooperation in the supply chain system of the new energy vehicle industry. It constructs profit functions for new energy vehicle manufacturers and core component suppliers in two different situations: competitive decision-making and cooperative decision-making. The optimal factor values and profit values of each subject are obtained, and case analysis is conducted. Research has found that: (1) Whether in competitive or cooperative decision-making situations, the optimal factor values of each subject are influenced by their respective costs and show an increasing trend. (2) By comparison, it is found that the optimal profit of new energy vehicle manufacturers under cooperative decision-making and the overall optimal profit of the new energy vehicle industry supply chain system are better than those under competitive decision-making. (3) The profit growth rate of core component suppliers of new energy vehicles and the supply chain system of the new energy vehicle industry under cooperative decision-making is significantly faster than that under competitive decision-making.

Based on the perspective of supply-demand imbalance, this article constructs a collaborative innovation decision-making model for the photovoltaic industry supply chain using differential game theory. It analyzes two different decision-making scenarios: decentralized decision-making and centralized decision-making, and focuses on studying the impact of cost sharing contracts under decentralized decision-making and revenue sharing contracts under centralized decision-making on the decision-making behavior of photovoltaic industry supply chain entities. Research has found that: 1) The supply-demand imbalance coefficient affects the pricing of photovoltaic silicon wafer suppliers. 2) In the case of decentralized decision-making, considering the cost sharing contract situation in the photovoltaic industry supply chain system can better optimize the profit value and innovation level of each subject in the photovoltaic industry supply chain. 3) The benefit sharing contract under centralized decision-making is more effective than the cost sharing contract under decentralized decision-making.

This article constructs a collaborative innovation decision-making model for the new energy vehicle industry chain under decentralized and carbon quota sharing contracts, and obtains the optimal parameter values and profit values of the new energy vehicle industry entities under two different scenarios. Taking BYD's new energy vehicle industry as a case study, the beneficial effect of carbon sharing contracts on the collaborative decision-making of the new energy vehicle industry system is empirically analyzed. Research has found that although carbon sharing contracts may weaken the willingness of new energy vehicle battery suppliers to innovate in carbon reduction, they will effectively improve their innovation in the range of new energy vehicles. The market price of new energy vehicle manufacturers under carbon sharing contracts decreases with the increase of the carbon sharing coefficient. Carbon sharing contracts can significantly increase the profits of the main players in the new energy vehicle industry system, and are directly proportional to the carbon sharing coefficient of the contract.

The 531 New Deal has gradually transitioned the photovoltaic market policy from industrial policy to competition policy. This paper considers the two policy orientations of the photovoltaic supply chain: industrial policy and competition policy. Based on differential game theory, the profit models of photovoltaic supply chain entities under the two policy orientations are constructed, and the optimal solutions of each model are solved. The research finds that policy guidance factors affect the strategic choices of photovoltaic supply chain entities; Compared to industrial policies, competition policy orientation can increase the profits of various entities in the photovoltaic supply chain to varying degrees.

With the annual promotion of the international “dual carbon” goals, countries attach great importance to the development and innovation of clean energy. The United States, Japan, and China have all created many policies for the research and market development of photovoltaic energy. This article incorporates market dynamic regulation capability into a two-dimensional system of government subsidy policies and photovoltaic revenue, constructs a three-dimensional dynamic nonlinear model based on market dynamic regulation capability, government subsidies, and enterprise revenue, and numerically simulates and analyzes the impact of parameter and initial value changes in the equation on enterprise revenue. The market dynamic regulation capability is obtained from Chaotic attractors and dynamic evolution graphs of the nonlinear evolution between government subsidies and corporate profits in different scenarios. Research has shown that: (1) Rapidly improving the dynamic regulation ability of the market cannot continuously increase the revenue of the photovoltaic industry; (2) The changes in market dynamics affect the dependence of enterprises on government subsidies; (3) The demand for government subsidies by enterprises gradually decreases with the increase of their own profits.

This paper develops a comprehensive evaluation index system designed to measure the performance of scientific and technological achievements transformation in colleges and universities. Recognizing the inherent fuzziness and uncertainty in performance indicators, the study introduces a novel evaluation approach that integrates fuzzy logic with the TOPSIS decision-making method, enhanced through the IVPFOWA (Interval-Valued Pythagorean Fuzzy Ordered Weighted Averaging) operator. The IVPFOWA operator is first defined to establish the theoretical foundation for handling fuzzy attribute data. Building on this, the paper outlines the detailed steps of the TOPSIS evaluation decision process when combined with the IVPFOWA operator, demonstrating how the method can effectively address ambiguity in performance assessment. To validate the practicality and effectiveness of the proposed framework, Jiangsu University of Science and Technology is selected as a case study. The results confirm that the method provides a more reliable and adaptable tool for evaluating transformation performance under complex and uncertain conditions.

Introduce government competition policies and technological innovation efforts into the profit game model of the photovoltaic industry supply chain, establish two different supply chain profit models, and study the impact of government competition policies and manufacturers' technological innovation efforts on the profits of each manufacturer and the overall profit of the supply chain. Construct profit models in both competitive and cooperative situations, and empirically analyze the impact of government competition policies and manufacturers' technological innovation efforts on the optimal supply chain profits in both competitive and cooperative situations. Research has shown that: (1) government competition policies are conducive to promoting an increase in manufacturers' profits; (2) The increase in technological innovation efforts can quickly increase manufacturers' profits; (3) Compared to the cooperation situation, the profit of each manufacturer and the total profit of the entire supply chain are higher in the competitive situation.

From the perspective of carbon quota policy, we consider integrating carbon quota sharing contracts into the collaborative decision-making model of the photovoltaic industry chain and compare and explore the collaborative decision-making of the photovoltaic industry chain under decentralized decision-making and considering carbon quota sharing contracts. Research has found that carbon quota sharing contracts can effectively promote green innovation among the main body of the photovoltaic industry chain; In the case of carbon quota sharing contracts, the pricing between photovoltaic system suppliers and photovoltaic power plant enterprises is lower; Under the carbon quota sharing contract, the profits, and overall profits of each entity in the photovoltaic industry chain are better than the optimal profits under decentralized conditions.

This research applies TOPSIS, which stands for Technique for Order of Preference by Similarity to Ideal Solution, to evaluate and rank the performance of telemedicine in the seven Chinese cities—Hangzhou, Wuhan, Chengdu, Shanghai, Beijing, Guangzhou, and Shenzhen. The evaluation was based on five major criteria: Infrastructure, Healthcare System Integration, Accessibility & Equity, Service Breadth & Quality and Regulatory Environment. In a noteworthy finding, Hangzhou was at the top all the time, while Shenzhen was at the bottom despite its technological might. The result was very strong, being the same even when the cost criterion was given 50% weight which showed that the price factor alone does not overpower other performance disparities. The outcomes are a surprise to the common understanding that very high-quality medical institutions in a city and very good technology infrastructure are the only factors that determine the success of telemedicine. Rather, a city’s ability to build an integrated, user-centered digital ecosystem determines the leadership in telemedicine. The first position of Hangzhou indicates the benefit of unrestricted healthcare accessibility through a platform-based system whereas the last position of Shenzhen points out the drawbacks of an expensive and inequitable system. This study shifts the paradigm for future telemedicine cities from "Medical Resource" to "Integrated Ecosystem" model, thus, posing significant implications for the decision makers who strive to ensure effective and equal access to digital health services.