Does the digital economy empower the green development of foreign trade?

The digital economy has become a new driving force for China's economic development in recent years, and it may contribute to solving the corresponding problems of resource and environmental pressure. Therefore, this study strives to explore whether the digital economy contributes to the green development of foreign trade. First, this study measures the digital economy development in China. Second, this study presents a list of environmental and polluting products and examines the impact of digital economy development on exports of representative products based on an extended gravity model. The main findings are as follows. First, the digital economy significantly promotes the green development of foreign trade. Second, the signing of Free Trade Agreements (FTAs) and the income level of importing countries and regions strengthen the role of the digital economy in promoting the green development of foreign trade. Third, the digital economy promotes the green development of foreign trade through green technological innovation. Finally, some policy implications are proposed based on the findings of this study.

Evaluating China's pilot carbon Emission Trading Scheme: collaborative reduction of carbon and air pollutants.

Collaborative reduction of carbon and air pollutants can more efficiently achieve green technological change, industrial low-carbon transition, and high-quality economic and social development. As a typical environmental policy in China, the pilot carbon Emission Trading Scheme (ETS) has obvious advantages in achieving the collaborative reduction of carbon and air pollutants. Therefore, an evaluation of China's pilot carbon ETS from the perspective of collaborative reduction of carbon and air pollutants is performed in this paper. Compared with previous studies, first, this study innovatively uses the coupled coordination degree (CCD) model to measure the collaborative reduction level of carbon and air pollutants under different scenarios based on the panel data of China's 30 provincial-level regions during 2004-2018. Second, this study uses the DID method to evaluate the impact of China's pilot carbon ETS on the collaborative reduction of carbon and air pollutants and conducts some robustness checks and regional heterogeneity regressions. Third, this study uses the synthetic control method (SCM) further to examine the policy outcomes of the pilot carbon ETS. Scenario analysis shows that attaching importance to reducing air pollution will improve the collaborative reduction effect of carbon and air pollutants. Furthermore, the implementation of China's pilot carbon ETS exerts an effect of roughly 24.7% on reducing carbon, roughly 10.1% on reducing air pollutants, and roughly 22.0% on the collaborative reduction of carbon and air pollutants, ceteris paribus. Regional heterogeneity analysis shows that the impacts of the pilot carbon ETS are significant in all regions, except that the impact on reducing air pollutants in the central region is not significant. In addition, results from SCM indicate that the impacts of the pilot carbon ETS on the collaborative reduction of carbon and air pollutants are significantly efficient in Beijing, Tianjin, Shanghai, Hubei, and Chongqing, while not much efficient in Guangdong and Fujian. The main policy implications include strengthening the top-level design of the ETS in the collaborative reduction of carbon and air pollutants, attaching importance to the governance of air pollution, making the regional governance more targeted, and improving energy efficiency.

Controlling the Phase Behavior and Reflection of Main-Chain Cholesteric Oligomers Using a Smectic Monomer.

Cholesteric liquid crystals (CLCs) are a significant class of temperature-responsive photonic materials that have the ability to selectively reflect light of a specific wavelength. However, the fabrication of main-chain CLC oligomers with dramatic reflection band variation upon varying the temperatures remains a challenge. Here, a feasible method for improving and controlling the responsiveness of main-chain cholesteric liquid crystal oligomers by the incorporation of a smectic monomer is reported. The smectic monomer strengthens the smectic character of the oligomers and enhances the magnitude of the change of the pitch as a function of temperature upon approaching the cholesteric-smectic phase transition temperature. The central wavelength of the reflection band can be easily modified by mixing in an additional chiral dopant. This promising method will open the door to the preparation of temperature-responsive photonic devices with excellent responsiveness.

Synthesis of MOF-199/CNTs Nanocomposite for Selective Adsorption and Determination of Nonsteroidal Anti-Inflammatory Drugs in Human Urine.

A hybrid nanocomposite containing a moisture-resistant surface based on MOF-199 and carbon nanotubes (CNTs) was synthesized. Characterization was undertaken using powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The adsorption behavior of the MOF-199/CNTs composite to ibuprofen was then investigated at room temperature. Experimentation revealed that the hybrid absorbent had excellent adsorption capacity for the nonsteroidal anti-inflammatory drug (NSAID), ibuprofen, with maximum adsorption up to 40.8 mg/g. The adsorbent was able to be recycled several times without deactivation. Finally, the MOF-199/CNTs composite was used as the extraction sorbents for selective extraction of ibuprofen, ketoprofen and naproxen in human urine. The results showed successful application of the nanocomposite to NSAID analysis in spiked human urine samples. Recoveries at three concentrations were 89.7-96.8%, 79.3-85.5% and 95.6-97.5% for ibuprofen, ketoprofen and naproxen, respectively. The relative standard deviations (RSDs) were within the range of 2.9-5.3%. The results demonstrated that the MOF-199/CNTs composite is an excellent adsorbent for determination of NSAIDs in spiked urine samples.