Search

There are many ships and ports in Shanghai coastal zones, where disastrous weather occurs frequently. Meteorological disasters often threaten the safety of people’s lives and properties along the coast and in the ports. In the past, the meteorological warnings for Shanghai coastal zones are mainly based on those issued for Yangshan Port by Shanghai Marine Meteorological Centre (SMMC), which are called “unified warnings”. However, there are obvious differences in the time and intensity of meteorological disasters in each region, and the unified warnings cannot meet the needs of the production and operation of the shipping and ports. In 2020, Shanghai coastal zones were divided into five sub-zones, where the meteorological forecast and warnings were carried out separately from July 2020. Based on hourly observational data of the representative stations in Shanghai coastal zones and warning signal data from 2016 to 2022, the gale events are selected to analyse the statistical characteristics of temporal and spatial distribution and evaluate the forecast quality and the economic benefits of the zonal warnings. The results show that: (1) The farther away from the coastline, the more gale days, the higher the wind speed and the longer the duration; the higher the wind speed during the process, the more obvious the difference of wind scale. In particular, the wind scale caused by typhoons can range up to 5 levels. (2) Compared with the “unified warning”, the missing alarm rate (MAR) of gale warnings in each sea area has been reduced significantly, by up to 5%, the false alarm rate (FAR) for the western part of Yangtze River estuary is reduced by more than 8% and the TS score is significantly improved by more than 10%. (3) The advance time of gale warnings has been reduced by more than 3 hours, the maintaining duration has been shortened by more than 16 hours at most, which can reduce the loss of nearly 18 million RMB and improve the production efficiency of the coastal zones of Shanghai greatly. The results of this paper show that refined marine meteorological forecasts and early warnings provide a safety guarantee for marine transportation and port production operations, resulting in significant social and economic benefits and the enhancement of the comprehensive guarantee level of marine meteorological services in Shanghai. In the next step, we will continue to research and develop more refined objective forecast methods adapted to this business, then build a regional shared operational system platform and extend it to the Yangtze River Delta region, so as to promote the high-quality development of shipping meteorological integration in the Yangtze River Delta region.

The gas pressure of gas insulated switchgear (GIS) is the key factor affecting the sensitivity of partial discharge (PD) detection. In this paper, four defect models, tip, suspension, void, surface, are constructed on the PD experimental platform. PD experiments are carried out at different pressures, 0.2 MPa-0.5 MPa. Ultra-high frequency (UHF), high-frequency current transform (HFCT) and acoustic emission (AE) methods are used, and the sensitivity of HFCT and AE methods for PD signal detection is compared. The results show that SF6 pressure is a key parameter affecting tip discharge, suspension discharge and surface defect discharge. Under these defects, the partial discharge initial voltage (PDIV) is proportional to SF6 pressure, and the discharge amplitude and pulse number are inversely proportional to SF6 pressure. For the void defect, the change of external SF6 pressure does not affect the void gas pressure, and thus does not significantly affect the cavity discharge intensity. The HFCT method can effectively detect suspension defects, however, it cannot detect the PD signals of void and tip defects. As the SF6 pressure decreases, the sensitivity of HFCT method to detect surface defects increases, although the sensitivity is not comparable to that of the UHF method. The AE method can detect suspension and tip defects effectively, but cannot detect PD signals of void and surface defects. The detection sensitivity of the AE method for tip defects gradually increases with the decrease of SF6 pressure. When the pressure is 0.2 MPa, the detection sensitivity is equivalent to that of the UHF method.

AbstractAn efficient and concise synthesis of phomopsolidone B was accomplished in nine longest linear steps from readily available chiral template, L-arabinose and L-ethyl lactate. The synthesis features rapid access to the key chiral backbone from chiral pools and the formation of furanone skeleton employing a late-stage olefin cross-metathesis. [ABSTRACT FROM AUTHOR]

Electrocatalytic glycerol oxidation reaction (GOR) stands out as an economical and prospective technology to replace oxygen evolution reaction for co‐producing high‐valued chemicals and hydrogen (H2). Regulating the adsorption of glycerol (GLY) and hydroxyl (OH) species is of great significance for improving the GOR performance. Herein, a hierarchical p–n heterojunction by combining Co‐metal organic framework (MOF) nanosheets with CuO nanorod arrays (CuO@Co‐MOF) is developed to realize the optimization on GOR. Specifically, CuO@Co‐MOF electrode exhibits superior performance with a conversion of 98.4%, formic acid (FA) selectivity of 87.3%, and Faradaic efficiency (FE) of 98.9%. The flow‐cell system with the bifunctional CuO@Co‐MOF electrode for pairing GOR with the hydrogen evolution reaction (HER) reveals better energy conversion efficiency. Experimental results and theoretical calculations unravel the redistributed electric field by introducing Co‐containing species that contribute to the improved performance, which not only enhances the OH adsorption but also modulates the excessive GLY adsorption of CuO, thus reducing reaction energy barriers of FA desorption. Simultaneously, finite element analysis reveals that the novelty hierarchical structure can increase the concentration of OH− and facilitate the mass transfer of OH− in the solution. [ABSTRACT FROM AUTHOR]

Species geographic distribution and conservation priority areas are important bases for in situ biodiversity conservation and conservation decision‐making. In view of the urgency of endangered species protection, eight representative endangered species in the typical forest ecosystem of the Greater and Lesser Khingan Mountains were studied. Based on 1127 occurrence points and environmental data collected from 2016 to 2021, used BIOMOD2 and Zonation to reconstruct the potential distribution area and identify conservation priority areas of eight species (Tetrao parvirostris, T. tetrix, Gulo gulo, Alces alces, Martes zibellina, Moschus moschiferus, Lynx lynx, Lutra lutra). The results showed potential distribution areas for almost all species concentrated in the northern part of the Greater Khingan Mountains (GKM) and the central part of the Lesser Khingan Mountains (LKM). The potential distribution areas of each species were as follows: black‐billed capercaillie, 102,623 km2; black grouse, 162,678 km2; wolverine, 63,410 km2; moose, 140,287 km2; sable, 112,254 km2; Siberian musk deer, 104,787 km2; lynx, 139,912 km2; and Eurasian otter, 49,386 km2. Conservation priority areas (CPAs) clustered in the north GKM and central LKM and totaled 220,801 km2, and only 16.94% of the CPAs were currently protected by nature reserves. We suggest that the Chinese government accelerate the integration of existing protected areas in the northern GKM and establish a larger GKM National Park based on cost‐effective multi‐species protection. [ABSTRACT FROM AUTHOR]

Pyroptosis, an inflammatory form of programmed cell death, is linked to the pathology of rheumatoid arthritis (RA). Here, we investigated the molecular mechanism underlying pyroptosis in T cells isolated from patients with RA. Compared with healthy individuals, patients with RA had more pyroptotic CD4+ T cells in blood and synovia, which correlated with clinical measures of disease activity. Moreover, the mRNA expression and protein abundance of arachidonate 5-lipoxygenase (ALOX5), which converts arachidonic acid to leukotriene A4 (LTA4), were increased in CD4+ T cells from patients with RA and, among patients with RA, were lowest in those in clinical remission. Knockdown or pharmacological inhibition of ALOX5 suppressed CD4+ T cell pyroptosis and improved symptoms in two rodent models of RA. Mechanistically, the increase in ALOX5 activity in RA CD4+ T cells enhanced the production of the LTA4 derivative LTB4, which stimulated Ca2+ influx through ORAI3 channels, leading to the activation of NLRP3 inflammasomes and pyroptosis. Our findings reveal a role for ALOX5 in RA and provide a molecular basis for further exploring the clinical utility of ALOX5 inhibition in RA and for using ALOX5 as a biomarker to distinguish active disease and remission in RA. Editor's summary: Pyroptosis of CD4+ T cells is associated with synovial inflammation in rheumatoid arthritis (RA). Cai et al. found that increased abundance of the leukotriene biosynthetic enzyme ALOX5 in circulating and synovium-infiltrating CD4+ T cells drove pyroptosis in these cells, which correlated with the clinical severity of RA. Leukotrienes generated by ALOX5 stimulated Ca2+ influx through ORAI3 channels that led to inflammasome activation and pyroptosis. The FDA-approved ALOX5 inhibitor zileuton suppressed CD4+ T cell pyroptosis and reduced joint inflammation in rodent models of RA, suggesting ALOX5 as a potential therapeutic target in RA. —Annalisa M. VanHook [ABSTRACT FROM AUTHOR]

Stereoselective total syntheses of (+)‐goniochelienlactone, (+)‐7‐acetylgoniochelienlactone and (−)‐goniopypyrone were accomplished by divergent strategies starting from readily available chiral pool methyl α‐D‐mannopyranoside. The present work provided an efficient strategy for the stereoselective construction of highly functionalized dioxabicyclo[3.3.1]nonan‐3‐one ring system through a sequential Bernet‐Vasella‐type reductive elimination/nucleophilic addition and a sequential cross‐metathesis/intramolecular oxa‐Michael addition in a one‐pot process. [ABSTRACT FROM AUTHOR]

The effects of molecular size on SiO2 deposition regulated surface barriers and zeolite catalysis are probed, taking n-pentane isomerization and benzene alkylation with ethylene as model reactions. Chemical liquid deposition of SiO2 on the parent ZSM-5 sample only modifies its external surface slightly and passivates a small proportion of Brønsted acid sites. The apparent diffusivities increase significantly at 363–393K after SiO2 deposition, indicating SiO2 on ZSM-5 crystals reduces surface barriers at low temperatures. The conversion for n-pentane isomerization increases by up to 26% after SiO2 deposition, while the conversion for benzene alkylation decreases by up to 19%. Obviously, the positive effect of SiO2 deposition can be balanced out by the pore confinement effect at high temperatures, which is stronger for a larger molecule. This work provides a unique understanding of molecular size effects on surface barriers, which should serve to guide the design of zeolite catalysts. [ABSTRACT FROM AUTHOR]