Campaign-style governance of air pollution in China? A comprehensive analysis of the central environmental protection inspection

Central environmental protection inspection (CEPI) is a major institutional innovation in China's environmental governance, but its effectiveness in improving air quality is still unclear. However, the effectiveness of CEPI is of great significance and can be regarded as an important reference for deepening the reform of environmental governance system in China. This article takes the CEPI as a quasi-natural experiment and uses the regression discontinuity design (RDD) and the difference-in-differences (DID) methods to examine the effectiveness of this policy. The study found that the first round of CEPI reduced the air pollution of cities in the inspected provinces in a short time. Moreover, this positive policy effect persisted in the aftermath of the inspection, but this long-term effect is mainly reflected in PM10 and SO2. Heterogeneity analysis showed that CEPI was only effective in reducing air pollutants of industry-oriented cities, cities in Central and Eastern China, and cities with large or small population size. The moderating effect analysis indicated that a healthy relationship (close and clean) between the local governments and businesses was conducive to reducing air pollution. The research confirmed the presence of “selective” reduction of air pollutants in the long run caused by CEPI, thereby providing new inspiration for the improvement of campaign-style environmental governance and the follow-up CEPI work

A High Step-up Modular Isolated DC-DC Converter for Large Capacity Photovoltaic Generation System integrated into MVDC Grids

Nowadays, the research and design of the DC-DC conversion system has become more and more popular in the application of photovoltaic generation into the medium voltage DC (MVDC) grids. A novel high power modular isolated DC-DC converter with high step-up ratio is proposed as a module of the DC-DC conversion system in this paper. Based on the input parallel and output series (IPOS) connections of the proposed modular converters, the system is easy to achieve high capacity and high voltage. A two-stage structure is employed in the proposed converter. The interleaved boost topology is applied to the front-stage, which realizes MPPT for PV arrays with low input current ripples. The full-bridge LLC topology is employed as the back-stage, which lowers power losses by the implementation of soft-switching. The voltage gain of the proposed converter is derived in detail. The theoretical analysis and control strategy are studied in depth. Simulation and experiment verify the feasibility and effectiveness of the proposed converter.N

Expounding the role of tick in Africa swine fever virus transmission and seeking effective prevention measures: A review

African swine fever (ASF), a highly contagious, deadly infectious disease, has caused huge economic losses to animal husbandry with a 100% mortality rate of the most acute and acute infection, which is listed as a legally reported animal disease by the World Organization for Animal Health (OIE). African swine fever virus (ASFV) is the causative agent of ASF, which is the only member of the Asfarviridae family. Ornithodoros soft ticks play an important role in ASFV transmission by active biological or mechanical transmission or by passive transport or ingestion, particularly in Africa, Europe, and the United States. First, this review summarized recent reports on (1) tick species capable of transmitting ASFV, (2) the importance of ticks in the transmission and epidemiological cycle of ASFV, and (3) the ASFV strains of tick transmission, to provide a detailed description of tick-borne ASFV. Second, the dynamics of tick infection with ASFV and the tick-induced immune suppression were further elaborated to explain how ticks spread ASFV. Third, the development of the anti-tick vaccine was summarized, and the prospect of the anti-tick vaccine was recapitulated. Then, the marked attenuated vaccine, ASFV-G-ΔI177L, was compared with those of the anti-tick vaccine to represent potential therapeutic or strategies to combat ASF

Novel casting CoCrNiAl eutectic high entropy alloys with high strength and good ductility

Eutectic high-entropy alloys (EHEAs) have drawn increasing interest due to their fine castability as well as appealing properties in recent years. In this work, two bulk-casting Co20-x/3Cr20-x/3Ni50-x/3Al10+x (x = 8 and 9) EHEAs with regular L12/B2 lamellar morphologies were successfully fabricated and studied. Both EHEAs show high ultimate strength of ~1200 MPa combined with good uniform ductility (> 9%). Post-deformation transmission electron microscopy results indicated a high density of dislocations and stacking faults in the L12 lamellae, while no obvious dislocation in the B2 phases. This work can broaden the optimization of composition design in EHEAs and provide useful guidance for further development of CoCrNiAl EHEAs

Proton irradiation induced defects in T92 steels: An investigation by TEM and positron annihilation spectroscopy

In order to investigate proton irradiation damage on ferritic/martensitic T92 steels, both the unaged and aged (650 \ub0C for 15,000 h) T92 steels were irradiated with 250 keV protons to 0.01, 0.05 and 0.20 dpa at room temperature due to the lower dose rate of protons compared with heavy-ions. The microstructural evolution induced by thermal aging and proton irradiation was studied by transmission electron microscopy and positron annihilation spectroscopy, and the corresponding micromechanical property changes were investigated by nano-indentation. After 0.20 dpa proton irradiation, the dominant irradiation-induced dislocation loops were a0100 type loops for both the unaged and aged samples. The dislocation-type defects in the aged T92 sample were larger in size and higher in number density, compared with those in the unaged samples. Less vacancy-type defects induced by protons were detected in the aged than the unaged T92 samples under the same irradiation conditions. The higher number density of dislocation-type defects led to more severe irradiation hardening in the aged T92 samples