This paper explored how the government provides low-carbon subsidies for the manufacturers, retailers, and consumers in a secondary supply chain under cap-and-trade scheme. We calculated the best prices, emissions reductions, and the demands for common and low-carbon products when subsidizing each of the abovementioned market players. In particular, a comparative analysis of their equilibrium outcomes was made thereafter. The MATLAB simulation found that the optimal emissions reductions under the three subsidy modes were even and positively correlated to low-carbon subsidies, which, however, negatively correlated to the prices of both product types. Higher subsidies drove up demand for low-carbon products and dragged down that for common goods. But the prices of these products maintained the highest levels when consumers were subsidized; demand for common products was greater when subsidies went to retailers than to manufacturers or consumers, consequently generating the largest emissions and highest profits. When the subsidies were greater than 2pcBJ+4pc2K+12kε+4pc2e1J−18e1εJ48pcε, all three subsidy modes saw a drop in total carbon emissions. That being so, the government should offer proper subsidies before seeing energy-saving progress.

Today, modern logistics and transportation as a whole still have many problems such as high cost, low efficiency, and poor service quality. This article aims to improve the efficiency of various logistics departments. In order to explore the role of high-strength steel wires as carbon nanotubes in the construction of digital logistics systems, this article saves manpower and management costs in the logistics process and effectively manages information transportation and operating costs by sensing and controlling automated processing and operating procedures. It can effectively solve technical problems and create a complete logistics system that meets product needs. The results of the study show that through the transformation of traditional logistics through carbon nanotubes, the efficiency of digital logistics is relatively stable, with an average value of about 2.5, which takes more than 30% less time than traditional logistics.