In article number 1901545, Wenjun Zhang and co‐workers synthesize a novel nanoflower‐like electrocatalyst comprising of few‐layer nitrogen‐doped graphene encapsulated nickel copper alloy on porous ...graphic carbon framework by a facile and scalable method, and it exhibits high activity and excellent stability for hydrogen evolution.
Abstract
Metallic phthalocyanines are promising electrocatalysts for CO
2
reduction reaction (CO
2
RR). However, their catalytic activity and stability (especially under high potential) are still ...unsatisfactory. Herein, we synthesized a covalent organic polymer (COP‐CoPc) by introducing charge‐switchable viologen ligands into cobalt phthalocyanine (CoPc). The COP‐CoPc exhibits great activity for CO
2
RR, including a high Faradaic efficiency over a wide potential window and the highest CO partial current density among all ligand‐tuned phthalocyanine catalysts reported in the H‐type cell. Particularly, COP‐CoPc also shows great potential for practical applications, for example, a FE
CO
of >95% is realized at a large current density of 150 mA/cm
2
in a two‐electrode membrane electrode assembly reactor. Ex situ and in situ X‐ray absorption fine structure spectroscopy measurements and theory calculations reveal that when the charge‐switchable viologen ligands switch to neutral‐state ones, they can act as electron donors to enrich the electron density of Co centers in COP‐CoPc and enhance the desorption of *CO, thus improving the CO selectivity. Moreover, the excellent reversible redox capability of viologen ligands and the increased Co–N bonding strength in the Co–N
4
sites enable COP‐CoPc to possess outstanding stability under elevated potentials and currents, enriching the knowledge of charge‐switchable ligands tailored CO
2
RR performance.
Environmental information disclosure (EID), a typical informal environmental regulation with third-party participation, has been attracting much attention as to how effective it is in controlling ...pollution and saving energy. Yet little existing research has explored how to improve corporate energy efficiency (EE) from the perspective of informal environmental regulation. The paper show that EID can not only reduce pollution, but also significantly improve corporate EE, especially for exporting, large-scale, non-state-owned and growing firms. Our results are robust after a series of robustness checks. We further discuss plausible mechanism for the effect of EID on corporate EE: improving energy structure, increasing investment efficiency, and inhibiting innovation of firms in polluting industries, which is essentially a trade-off between EE improvement effect and EE reduction effect, and the EE improvement effect clearly prevail. In addition, government environmental regulation has positive moderating effect on the causal relationship between EID and EE of low-energy firms. However, the energy efficiency improvement effect of EID on high-energy firms is negatively moderated by government environmental regulations. This study provides new ideas for environmental governance in emerging countries through a rational balance of informal and formal environmental regulation.
•EID has significant positive effect on corporate energy efficiency.•Using DID approach and treatisg the release of PITI as quasi-natural experiment.•Chinese industrial firms pollution database in 2003–2012 is used.•EID can improve firms' EE by improving energy structure and investment efficiency.•Government environmental governance has positive moderating effect.
Mn4+-doped red-light-emitting phosphors have become a research hotspot that can effectively enhance photosynthesis and promote morphogenesis in plants. Herein, the red phosphor La3Mg2NbO9:Mn4+ was ...synthesized through the solid-state reaction method. The effects of adding H3BO3 and a charge compensator R+ (R = Li, Na, K) on the crystal structure, morphology, quantum efficiency, and luminous performance of the La3Mg2NbO9:Mn4+ phosphor were systematically analyzed, respectively. The results showed that adding H3BO3 flux and a charge compensator improved the quantum efficiency and luminescence intensity. The emission intensity of the phosphor was enhanced about 5.9 times when Li+ was used as the charge compensator, while it was enhanced about 240% with the addition of H3BO3 flux. Remarkably, it was also found that the addition of H3BO3 flux and a charge compensator simultaneously improved the thermal stability at 423 K from 47.3% to 68.9%. The prototype red LED fabricated using the La3Mg2NbO9:Mn4+,H3BO3,Li+ phosphor exhibited a perfect overlap with the phytochrome absorption band for plant growth. All of these results indicate that the La3Mg2NbO9:Mn4+,H3BO3,Li+ phosphor has great potential for use in agricultural plant lighting.
Mnsup.4+-doped red-light-emitting phosphors have become a research hotspot that can effectively enhance photosynthesis and promote morphogenesis in plants. Herein, the red phosphor ...Lasub.3Mgsub.2NbOsub.9:Mnsup.4+ was synthesized through the solid-state reaction method. The effects of adding Hsub.3BOsub.3 and a charge compensator Rsup.+ (R = Li, Na, K) on the crystal structure, morphology, quantum efficiency, and luminous performance of the Lasub.3Mgsub.2NbOsub.9:Mnsup.4+ phosphor were systematically analyzed, respectively. The results showed that adding Hsub.3BOsub.3 flux and a charge compensator improved the quantum efficiency and luminescence intensity. The emission intensity of the phosphor was enhanced about 5.9 times when Lisup.+ was used as the charge compensator, while it was enhanced about 240% with the addition of Hsub.3BOsub.3 flux. Remarkably, it was also found that the addition of Hsub.3BOsub.3 flux and a charge compensator simultaneously improved the thermal stability at 423 K from 47.3% to 68.9%. The prototype red LED fabricated using the Lasub.3Mgsub.2NbOsub.9:Mnsup.4+,Hsub.3BOsub.3,Lisup.+ phosphor exhibited a perfect overlap with the phytochrome absorption band for plant growth. All of these results indicate that the Lasub.3Mgsub.2NbOsub.9:Mnsup.4+,Hsub.3BOsub.3,Lisup.+ phosphor has great potential for use in agricultural plant lighting.
Certain low pathogenic avian influenza viruses can mutate to highly pathogenic viruses when they circulate in domestic poultry, at which point they can cause devastating poultry diseases and severe ...economic damage. The H7N9 influenza viruses that emerged in 2013 in China had caused severe human infections and deaths. However, these viruses were nonlethal in poultry. It is unknown whether the H7N9 viruses can acquire additional mutations during their circulation in nature and become lethal to poultry and more dangerous for humans. Here, we evaluated the evolution of H7N9 viruses isolated from avian species between 2013 and 2017 in China and found 23 different genotypes, 7 of which were detected only in ducks and were genetically distinct from the other 16 genotypes that evolved from the 2013 H7N9 viruses. Importantly, some H7N9 viruses obtained an insertion of four amino acids in their hemagglutinin （HA） cleavage site and were lethal in chickens. The index strain was not lethal in mice or ferrets, but readily obtained the 627K or 701N mutation in its PB2 segment upon replication in ferrets, causing it to become highly lethal in mice and ferrets and to be transmitted efficiently in ferrets by respiratory droplet. H7N9 viruses bearing the HA insertion and PB2 627K mutation have been detected in humans in China. Our study indicates that the new H7N9 mutants are lethal to chickens and pose an increased threat to human health, and thus highlights the need to control and eradicate the H7N9 viruses to prevent a possible pandemic.
To survey hepatitis B virus (HBV) integration in liver cancer genomes, we conducted massively parallel sequencing of 81 HBV-positive and 7 HBV-negative hepatocellular carcinomas (HCCs) and adjacent ...normal tissues. We found that HBV integration is observed more frequently in the tumors (86.4%) than in adjacent liver tissues (30.7%). Copy-number variations (CNVs) were significantly increased at HBV breakpoint locations where chromosomal instability was likely induced. Approximately 40% of HBV breakpoints within the HBV genome were located within a 1,800-bp region where the viral enhancer, X gene and core gene are located. We also identified recurrent HBV integration events (in ≥ 4 HCCs) that were validated by RNA sequencing (RNA-seq) and Sanger sequencing at the known and putative cancer-related TERT, MLL4 and CCNE1 genes, which showed upregulated gene expression in tumor versus normal tissue. We also report evidence that suggests that the number of HBV integrations is associated with patient survival.
The size and shape of the plant leaf is an important agronomic trait. To understand the molecular mechanism governing plant leaf shape, we characterized a classic rice (Oryza sativa) dwarf mutant ...named narrow leaf1 (nal1), which exhibits a characteristic phenotype of narrow leaves. In accordance with reduced leaf blade width, leaves of nal1 contain a decreased number of longitudinal veins. Anatomical investigations revealed that the culms of nal1 also show a defective vascular system, in which the number and distribution pattern of vascular bundles are altered. Map-based cloning and genetic complementation analyses demonstrated that Nal1 encodes a plant-specific protein with unknown biochemical function. We provide evidence showing that Nal1 is richly expressed in vascular tissues and that mutation of this gene leads to significantly reduced polar auxin transport capacity. These results indicate that Nal1 affects polar auxin transport as well as the vascular patterns of rice plants and plays an important role in the control of lateral leaf growth.
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