Results of the parallel trend test.

To strengthen cooperation among local governmental departments and improve water ecology, China has proposed the river management policy "river chief system + procurator". However, it remains to be verified that intergovernmental cooperative policies contribute to the improvement of China’s water ecology. Based on data from 87 national water quality monitoring sites released by the China Environmental Monitoring Station from 2015 to 2022, this paper constructed a multiperiod differences-in-differences model to evaluate the effectiveness of the cooperative governmental policy, the "river chief system + procurator", on the improvement of the water quality of rivers and lakes. The results of the study show that cooperative government policy helps to improve the water environment of rivers and lakes, which means that the implementation of the "river chief system + procurator" policy has significantly improved water quality conditions where implemented. In addition, further analysis revealed that intergovernmental cooperative policies had a limited impact on relevant indicators of river and lake pollutants that are more susceptible to different pollution sources compared to the comprehensive indicator of water quality class. This study helps further the understanding of the effects of cooperative intergovernmental policies and the policy practice of environmental governance in China.</div

Description of surface water pollutant indicator.

To strengthen cooperation among local governmental departments and improve water ecology, China has proposed the river management policy "river chief system + procurator". However, it remains to be verified that intergovernmental cooperative policies contribute to the improvement of China’s water ecology. Based on data from 87 national water quality monitoring sites released by the China Environmental Monitoring Station from 2015 to 2022, this paper constructed a multiperiod differences-in-differences model to evaluate the effectiveness of the cooperative governmental policy, the "river chief system + procurator", on the improvement of the water quality of rivers and lakes. The results of the study show that cooperative government policy helps to improve the water environment of rivers and lakes, which means that the implementation of the "river chief system + procurator" policy has significantly improved water quality conditions where implemented. In addition, further analysis revealed that intergovernmental cooperative policies had a limited impact on relevant indicators of river and lake pollutants that are more susceptible to different pollution sources compared to the comprehensive indicator of water quality class. This study helps further the understanding of the effects of cooperative intergovernmental policies and the policy practice of environmental governance in China.</div

Placebo test results.

To strengthen cooperation among local governmental departments and improve water ecology, China has proposed the river management policy "river chief system + procurator". However, it remains to be verified that intergovernmental cooperative policies contribute to the improvement of China’s water ecology. Based on data from 87 national water quality monitoring sites released by the China Environmental Monitoring Station from 2015 to 2022, this paper constructed a multiperiod differences-in-differences model to evaluate the effectiveness of the cooperative governmental policy, the "river chief system + procurator", on the improvement of the water quality of rivers and lakes. The results of the study show that cooperative government policy helps to improve the water environment of rivers and lakes, which means that the implementation of the "river chief system + procurator" policy has significantly improved water quality conditions where implemented. In addition, further analysis revealed that intergovernmental cooperative policies had a limited impact on relevant indicators of river and lake pollutants that are more susceptible to different pollution sources compared to the comprehensive indicator of water quality class. This study helps further the understanding of the effects of cooperative intergovernmental policies and the policy practice of environmental governance in China.</div

Description of surface water grade classification.

Description of surface water grade classification.</p

Descriptive statistics of quantitative variables.

To strengthen cooperation among local governmental departments and improve water ecology, China has proposed the river management policy "river chief system + procurator". However, it remains to be verified that intergovernmental cooperative policies contribute to the improvement of China’s water ecology. Based on data from 87 national water quality monitoring sites released by the China Environmental Monitoring Station from 2015 to 2022, this paper constructed a multiperiod differences-in-differences model to evaluate the effectiveness of the cooperative governmental policy, the "river chief system + procurator", on the improvement of the water quality of rivers and lakes. The results of the study show that cooperative government policy helps to improve the water environment of rivers and lakes, which means that the implementation of the "river chief system + procurator" policy has significantly improved water quality conditions where implemented. In addition, further analysis revealed that intergovernmental cooperative policies had a limited impact on relevant indicators of river and lake pollutants that are more susceptible to different pollution sources compared to the comprehensive indicator of water quality class. This study helps further the understanding of the effects of cooperative intergovernmental policies and the policy practice of environmental governance in China.</div

Results of the parallel trend test.

To strengthen cooperation among local governmental departments and improve water ecology, China has proposed the river management policy "river chief system + procurator". However, it remains to be verified that intergovernmental cooperative policies contribute to the improvement of China’s water ecology. Based on data from 87 national water quality monitoring sites released by the China Environmental Monitoring Station from 2015 to 2022, this paper constructed a multiperiod differences-in-differences model to evaluate the effectiveness of the cooperative governmental policy, the "river chief system + procurator", on the improvement of the water quality of rivers and lakes. The results of the study show that cooperative government policy helps to improve the water environment of rivers and lakes, which means that the implementation of the "river chief system + procurator" policy has significantly improved water quality conditions where implemented. In addition, further analysis revealed that intergovernmental cooperative policies had a limited impact on relevant indicators of river and lake pollutants that are more susceptible to different pollution sources compared to the comprehensive indicator of water quality class. This study helps further the understanding of the effects of cooperative intergovernmental policies and the policy practice of environmental governance in China.</div

Regression models of time-varying DID.

To strengthen cooperation among local governmental departments and improve water ecology, China has proposed the river management policy "river chief system + procurator". However, it remains to be verified that intergovernmental cooperative policies contribute to the improvement of China’s water ecology. Based on data from 87 national water quality monitoring sites released by the China Environmental Monitoring Station from 2015 to 2022, this paper constructed a multiperiod differences-in-differences model to evaluate the effectiveness of the cooperative governmental policy, the "river chief system + procurator", on the improvement of the water quality of rivers and lakes. The results of the study show that cooperative government policy helps to improve the water environment of rivers and lakes, which means that the implementation of the "river chief system + procurator" policy has significantly improved water quality conditions where implemented. In addition, further analysis revealed that intergovernmental cooperative policies had a limited impact on relevant indicators of river and lake pollutants that are more susceptible to different pollution sources compared to the comprehensive indicator of water quality class. This study helps further the understanding of the effects of cooperative intergovernmental policies and the policy practice of environmental governance in China.</div

Visualization 1: Dual-color multiple-particle tracking at 50-nm localization and over 100-µm range in 3D with temporal focusing two-photon microscopy

Cafeteria swimming revised video Originally published in Biomedical Optics Express on 01 October 2016 (boe-7-10-4187

A Membrane-Free Ferrocene-Based High-Rate Semiliquid Battery

We report here a ferrocene-based membrane-free, high-rate semiliquid battery that takes advantage of a highly soluble ferrocene/ferrocenium redox couple in nonaqueous phase. The designed battery exhibits stable capacity retention up to 94% of theoretical capacity of ferrocene (145 mAh g^–1) at a broad current rate up to 60 C owing to rapid mass transport in a liquid phase and fast redox kinetics. The diffusion coefficient and the standard reaction constant are determined to be in the order of 10^–6 cm² s^–1 and 10^–1 cm s^–1, respectively, orders of magnitude greater than those in a solid-phase electrode and those in conventional redox flow batteries. Additionally, the battery demonstrates power density and energy density exceeding 1400 W L^–1 and 40 Wh L^–1, respectively, and stable cyclability with capacity retention of ∼80% for 500 cycles. Compared with state-of-the-art energy storage technologies such as Li-ion batteries or conventional redox flow batteries, the proposed liquid battery shows the potential to be an efficient energy storage system with exceptionally high power and reasonable energy density