China's carbon emissions trading (CET) policy aims to force relevant enterprises to implement low‐carbon technology innovation and address environmental challenges through marketization means. ...However, how China's CET policy may affect enterprise technology innovation and whether this effect may differ in industries remain to be further investigated. Therefore, based on the panel data of listed enterprises covered by the CET policy in China during 2009–2017, this paper employs the difference‐in‐difference (DID) and DID‐based propensity score matching models to evaluate the effect of CET on technology innovation. The empirical results indicate that the effect of China's CET on the technology innovation of related enterprises is generally not significant during the sample period, but this effect presents evident industrial heterogeneity. Specifically, among the eight CET‐covered industries, the CET policy helps to improve technology innovation for power and aviation enterprises but not in the other six industries (i.e., steel, chemical, building material, petrochemical, nonferrous metals, and paper), which implies that China's CET policy still has great potential for promoting the technology innovation of related enterprises. In addition, the central findings remain robust when the system generalized method of moment and DID‐based coarsened exact matching models are applied to consider the influence of omitted variables, unobservable confounders, and different matching methods.
Given the complexity between China's financial development and carbon emissions, this paper uses some econometric techniques, including cointegration theory, Granger causality test, variance ...decomposition, etc., to explore the influence of financial development on carbon emissions. Results indicate that, first, China's financial development acts as an important driver for carbon emissions increase, which should be taken into account when carbon emissions demand is projected. Second, the influence of financial intermediation scale on carbon emissions outweighs that of other financial development indicators but its efficiency's influence appears by far weaker although it may cause the change of carbon emissions statistically. Third, China's stock market scale has relatively larger influence on carbon emissions but the influence of its efficiency is very limited. This to some extent reflects the relatively lower liquidity in China's stock markets. Finally, among financial development indicators, China's FDI exerts the least influence on the change of carbon emissions, due to its relatively smaller volume compared with GDP; but it is mainly utilized in carbon intensive sectors now, therefore, with the increase of China's FDI in the future, many efforts should be made to adapt its utilizing directions and play its positive role in promoting low-carbon development.
► This paper explores the influence of financial development on carbon emissions. ► China's financial development appears to be an important driver for carbon emissions increase. ► The influence of financial intermediation scale on carbon emissions outweighs that of other indicators. ► China's stock market scale has relatively larger influence on carbon emissions but the influence of its efficiency is very limited. ► China's FDI exerts the least influence on carbon emissions change, due to its relatively smaller volume compared with China's GDP.
Nitrogen‐doped carbon (NC) materials have been proposed as next‐generation oxygen reduction reaction (ORR) catalysts to significantly improve scalability and reduce costs, but these alternatives ...usually exhibit low activity and/or gradual deactivation during use. Here, we develop new 2D sandwich‐like zeolitic imidazolate framework (ZIF) derived graphene‐based nitrogen‐doped porous carbon sheets (GNPCSs) obtained by in situ growing ZIF on graphene oxide (GO). Compared to commercial Pt/C catalyst, the GNPCSs show comparable onset potential, higher current density, and especially an excellent tolerance to methanol and superior durability in the ORR. Those properties might be attributed to a synergistic effect between NC and graphene with regard to structure and composition. Furthermore, higher open‐circuit voltage and power density are obtained in direct methanol fuel cells.
Nitrogen‐doped: A new oxygen reduction reaction electrocatalyst was obtained from ZIF‐derived porous carbon and graphene. The catalyst exhibits high activity, superior tolerance to methanol, and good stability in comparison to commercial Pt/C catalyst.
The carbon emissions trading (CET) policy realizes the internalization of emission reduction costs of related enterprises, which may affect their investment and management decisions, but has seldom ...received attention. Therefore, based on the panel data of A-share listed enterprises in eight energy-and‑carbon-intensive industries in China during 2009–2018, this paper employs the difference-in-differences (DID) and the difference-in-differences based propensity score matching methods (PSM-DID) to empirically evaluate the impact of China's CET policy on investment expenditure of CET-covered enterprises in seven pilot regions. The results indicate that: first of all, the investment expenditure of CET-covered enterprises has been reduced by 0.2449% due to China's CET policy during the sample period in general. Second, this impact shows significant industrial and regional heterogeneity. The CET policy reduces the investment expenditure of related enterprises in the building material and steel industries, but not in the other six industries. It also has a reducing impact on the investment expenditure of related enterprises in Beijing and Guangdong, but not in the other five pilot regions. Third, the impact began to appear in the second year of the implementation of CET policy, and it has shown an increasingly strengthening trend with continuous implementation. In addition, the central findings remain robust when we test the parallel trend assumption and apply the difference-in-differences-in-differences (DDD) method to further eliminate the interference of other factors.
•The DID and PSM-DID method is used to evaluate the effect of China's CET policy.•China's CET policy has reduced the investment of CET-covered enterprises in general.•The effect of China's CET policy has some industry and regional heterogeneity.•The policy impact began to appear in 2013, and gradually strengthened.•The DDD model is used to further verify the robustness of the research results.
The market power represents market competitiveness and investment development opportunities for the enterprise. Carbon emissions trading scheme (ETS) increases the internal operation costs of ...enterprises, and changes the external development environment, so as to affect the market power of high-carbon enterprises. With this in mind, using the panel data of A-share listed high-carbon enterprises in China during 2009–2019, this paper applies the difference-in-differences method and mediating effect model to estimate the impact of China's ETS on the market power of high-carbon enterprises. We can find that: first, the implementation of China's ETS until 2019 has generally led to a 26.99% decline in the market power of high-carbon enterprises. Second, China's ETS has a negative impact on the market power of relevant enterprises mainly through reducing the level of horizontal integration but not vertical integration. Third, it has a significant negative impact on the market power of relevant enterprises in the petrochemical and chemical industries, but not in other six industries concerned. Meanwhile, its negative impact on the market power of state-owned enterprises, and high financing constraints and large-scale enterprises is relatively significant, and the impact on the reduction of market power level of high-carbon enterprises in regions with high carbon prices and high transaction scales is relatively obvious.
•The DID method is used to evaluate the effect of China's ETS.•Mediating effect model is used to test the impact mechanism.•China's ETS has reduced the market power of high-carbon enterprises.•Horizontal integration plays a mediating role in the impact on the market power.•The impact varies with different industries, enterprises and carbon markets.
2D covalent organic frameworks (COFs) could have well‐defined arrangements of photo‐ and electro‐active units that serve as electron or hole transport channels for solar energy harvesting and ...conversion, but their insufficient charge transfer and rapid charge recombination impede the sunlight‐driven photocatalytic performance. We report a new donor–acceptor (D–A) system, PyTz‐COF that was constructed from the electron‐rich pyrene (Py) and electron‐deficient thiazolo5,4‐dthiazole (Tz). With its bicontinuous heterojunction, PyTz‐COF demonstrated exceptional optoelectronic properties, photocatalytic ability in superoxide anion radical‐mediated coupling of (arylmethyl)amines and photoelectrochemical activity in sunlight‐driven hydrogen evolution. Remarkably, PyTz‐COF exhibited a photocurrent up to 100 μA cm−2 at 0.2 V vs. RHE and could reach a hydrogen evolution rate of 2072.4 μmol g−1 h−1. This work is paving the way for reticular design of highly efficient and highly active D–A systems for solar energy harvesting and conversion.
A covalent organic framework (COF) constructed from electron‐rich pyrene and electron deficient thiazolo5,4‐dthiazole bears donor–acceptor features. It creates efficient carrier pathways for efficient separation of photogenerated holes and electrons. The COF thus demonstrated high photocatalytic activity for amine‐coupling reactions and hydrogen production through water splitting.
NH4+ ions as charge carriers show potential for aqueous rechargeable batteries. Studied here for the first time is the NH4+‐storage chemistry using electrodeposited manganese oxide (MnOx). MnOx ...experiences morphology and phase transformations during charge/discharge in dilute ammonium acetate (NH4Ac) electrolyte. The NH4Ac concentration plays an important role in NH4+ storage for MnOx. The transformed MnOx with a layered structure delivers a high specific capacity (176 mAh g−1) at a current density of 0.5 A g−1, and exhibits good cycling stability over 10 000 cycles in 0.5 M NH4Ac, outperforming the state‐of‐the‐art NH4+ hosting materials. Experimental results suggest a solid‐solution behavior associated with NH4+ migration in layered MnOx. Spectroscopy studies and theoretical calculations show that the reversible NH4+ insertion/deinsertion is accompanied by hydrogen‐bond formation/breaking between NH4+ and the MnOx layers. These findings provide a new prototype (i.e., layered MnOx) for NH4+‐based energy storage and contributes to the fundamental understanding of the NH4+‐storage mechanism for metal oxides.
NH4+ storage using electrodeposited manganese oxides (MnOx) is studied for the first time. MnOx exhibits structural transformation during charge/discharge in dilute ammonium acetate (NH4Ac) electrolyte. Experimental and theoretical results suggest that the reversible NH4+ insertion/deinsertion in layered MnOx is associated with hydrogen‐bond formation/breaking between NH4+ and the MnOx layers.
This study examined the effects of parent–child communication, including the quantitative and qualitative aspects of these communications, on young American adolescents’ academic performance by using ...an Early Childhood Longitudinal Study-Kindergarten dataset. We considered children’s self-concept a mediator in examining the effects. Structural equation modeling was used for evaluating the model. The results revealed that the quality of parent–child communication was positively associated with these children’s academic performance, and this association can be mediated by the adolescents’ self-concept. However, the quantity of parent–child communication did not show a direct or an indirect association with the adolescents’ academic achievements. These findings suggest that efforts to improve the quality of parent–child communication and to strengthen the connection between high-quality communications and adolescents’ self-concept may benefit young adolescents’ academic development.
As the NN bond in N2 is one of the strongest bonds in chemistry, the fixation of N2 to ammonia is a kinetically complex and energetically challenging reaction and, up to now, its synthesis is still ...heavily relying on energy and capital intensive Haber–Bosch process (150–350 atm, 350–550 °C), wherein the input of H2 and energy are largely derived from fossil fuels and thus result in large amount of CO2 emission. In this paper, it is demonstrated that by using Au sub‐nanoclusters (≈0.5 nm ) embedded on TiO2 (Au loading is 1.542 wt%), the electrocatalytic N2 reduction reaction (NRR) is indeed possible at ambient condition. Unexpectedly, NRR with very high and stable production yield (NH3: 21.4 µg h−1 mg−1cat., Faradaic efficiency: 8.11%) and good selectivity is achieved at −0.2 V versus RHE, which is much higher than that of the best results for N2 fixation under ambient conditions, and even comparable to the yield and activation energy under high temperatures and/or pressures. As isolated precious metal active centers dispersed onto oxide supports provide a well‐defined system, the special structure of atomic Au cluster would promote other important reactions besides NRR for water splitting, fuel cells, and other electrochemical devices.
Using Au sub‐nanoclusters anchored on TiO2 substrate as a heterogeneous electrocatalyst, the special Au active sites lead to the effective and stable electrochemical N2 reduction reaction with high NH3 yield (21.4 µg h−1 mg−1cat.) and Faradaic efficiency (8.11%) as well as 100% NH3 selectivity at ambient conditions.
Cold-adapted alginate lyases have unique advantages for alginate oligosaccharide (AOS) preparation and brown seaweed processing. Robust and cold-adapted alginate lyases are urgently needed for ...industrial applications. In this study, a cold-adapted alginate lyase-producing strain
sp. W2 was screened. Then, the gene
was cloned from
W2 and expressed in a food-grade host,
. The secreted Alyw201 showed the activity of 64.2 U/mL, with a molecular weight of approximate 38.0 kDa, and a specific activity of 876.4 U/mg. Alyw201 performed the highest activity at 30 °C, and more than 80% activity at 25-40 °C. Furthermore, more than 70% of the activity was obtained in a broad pH range of 5.0-10.0. Alyw201 was also NaCl-independent and salt-tolerant. The degraded product was that of the oligosaccharides of DP (Degree of polymerization) 2-6. Due to its robustness and its unique pH-stable property, Alyw201 can be an efficient tool for industrial production.
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