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In this study, the multi-year data of meteorology and O3 from remote sensing and ground observations are applied to characterize the 3-D changes of O3 in the troposphere over central and eastern China (CEC) induced by the tropical cyclones (TCs) in the tropical and subtropical ocean regions over Northwest Pacific. The CEC-regional average of near-surface O3 levels is significantly elevated with 6.0 ppb in the large coverage by the TCs in the subtropical ocean, while the TCs in the tropical ocean alter near-surface O3 weakly, indicating the latitudinal-located TCs in the subtropical offshore ocean could largely influence the O3 variations over CEC. The sub-seasonal change with the positive and negative anomalies of near-surface O3 is induced by the tropical TCs from June to July and from August to October. The peripheral circulation of TCs in the subtropical offshore ocean persistently enhances the O3 concentrations over CEC during the season of East Asian summer monsoons. The positive O3 anomalies maintain from the entire troposphere to the lower stratosphere over CEC in the peripheries of subtropical TCs, while the tropical TCs cause the positive O3 anomalies merely in the lower troposphere. The O3 transport and accumulation, photochemical production and stratospheric intrusion are climatologically confirmed as the major meteorological mechanisms of TCs affecting the O3 variations. This study reveals that the downward transport of stratospheric O3 of TCs in the subtropical ocean exerts a large impact on the atmospheric environment over CEC, while the regional O3 transport and photochemical productions dominate the lower troposphere over CEC with less impact of stratospheric intrusion from the TCs in the tropical ocean region. These results present the climatology of tropospheric O3 anomalies in China induced by the TCs over the Northwest Pacific with enhancing our comprehension of the meteorological impact on O3 variations over the East Asian monsoon region.

This study focuses on addressing the pollution caused by Ni in water. To enhance the removal efficiency of Ni2+, attapulgite (ATP) from Linze County, Gansu Province, China, was used as a carrier to prepare attapulgite loaded with nanoscale zero-valent iron (nZVI@ATP) via a liquid-phase reduction. This approach aims to mitigate the aggregation and oxidation tendencies of nZVI, thereby improving its performance in Ni2+ removal. The results revealed that nZVI@ATP exhibited a mesoporous structure with a specific surface area and an average pore size of 51.79 m2/g and 9.22 nm. Notably, nZVI@ATP showed a remarkably reduced agglomeration phenomenon. In addition, nZVI@ATP demonstrated a considerably more excellent adsorption performance for Ni2+ than raw ATP and pure nZVI, as its highest adsorption capacity was 143.20 mg/g when the iron–ATP ratio was 2:1 (initial concentration: 200 mg/L, initial pH: 5, temperature: 298 K, and dosing amount: 1 g/L). The adsorption of Ni2+ by nZVI@ATP followed the quasi-secondary kinetic model, and the removal rate of Ni2+ was inversely proportional to the initial concentration and directly proportional to the dosage. The adsorption capacity tended to increase and then decrease as the pH increased. The removal mechanism of Ni2+ by nZVI@ATP involved adsorption, reduction, and precipitation, with the significant mechanism being the induced Ni(OH)2 precipitation on the nZVI@ATP surface.

A quick and effective way of segmenting images is the Otsu threshold method. However, the complexity of time grows exponentially as the number of thresolds rises. The aim of this study is to address the issues with the standard threshold image segmentation method’s low segmentation effect and high time complexity. The two mutations differential evolution based on adaptive control parameters is presented, and the twofold mutation approach and adaptive control parameter search mechanism are used. Superior double-mutation differential evolution views Otsu threshold picture segmentation as an optimization issue, uses the maximum interclass variance technique as the objective function, determines the ideal threshold, and then implements multi-threshold image segmentation. The experimental findings demonstrate the robustness of the enhanced double-mutation differential evolution with adaptive control parameters. Compared to other benchmark algorithms, our algorithm excels in both image segmentation accuracy and time complexity, offering superior performance.

The influence of the underlying surface on the atmospheric environment over rivers and lakes is not fully understood. To improve our understanding, this study targeted the Twain-Hu Basin (THB) in central China, with a unique underlying surface comprising a dense “water network” over rivers and lakes. In this study, the Weather Research and Forecasting Model with Chemistry (WRF-Chem) was used to simulate the impact of this dense “water network” on a wintertime heavy PM2.5 pollution event in the THB. On this basis, the regulating effects of density and area of the lake groups, with centralized big lakes (CBLs) and discrete small lakes (DSLs), on PM2.5 concentrations over the underlying surface of the dense “water network” in the THB were clarified, and the relative contributions of thermal factors and water vapor factors in the atmospheric boundary layer to the variation of PM2.5 concentrations were evaluated. The results show that the underlying surface of dense “water networks” in the THB generally decreases the PM2.5 concentrations, but the influences of different lake-group types are not uniform in spatial distribution. The CBLs can reduce the PM2.5 concentrations over the lake and its surroundings by 4.90–17.68% during the day and night. The ability of DSLs in reducing PM2.5 pollution is relatively weak, with the reversed contribution between −5.63% and 1.56%. Thermal factors and water vapor–related factors are the key meteorological drivers affecting the variation of PM2.5 concentrations over the underlying surface of dense “water networks”. The warming and humidification effects of such underlying surfaces contribute positively and negatively to the “purification” of air pollution, respectively. The relative contributions of thermal factors and water vapor–related factors are 52.48% and 43.91% for CBLs and 65.96% and 27.31% for DSLs, respectively. The “purification” effect of the underlying surface with a dense “water network” in the THB on regional air pollution highlights the importance of environmental protection of inland rivers and lakes in regional environmental governance. In further studies on the atmospheric environment, long-term studies are necessary, including fine measurements in terms of meteorology and the environment and more comprehensive simulations under different scenarios.

In this study, attapulgite-supported nano zero-valent iron (nZVI@ATP) was synthesized by a liquid-phase reduction method using active attapulgite (ATP) as raw material, and used for Pb2+ remediation in aqueous solution. To understand the mechanism of Pb2+ removal, various techniques were used to characterize nZVI@ATP. The results showed that spherical nZVI particles were uniformly dispersed on the surface of ATP, and the agglomeration of nZVI particles was significantly weakened. The adsorption performance of nZVI@ATP for Pb2+ was greatly improved compared with that of ATP ore, in which the Fe/ATP mass ratio of 1:2 was the best loading ratio. Under the conditions of a temperature of 25 °C and a pH of 5.00, the initial concentration of Pb2+ was 700 mg/L, and the Pb2+ removal rate of nZVI@ATP was 84.47%. The adsorption of nZVI@ATP to Pb2+ was mainly a spontaneous endothermic reaction of heterogeneous surfaces, and the adsorption rate of nZVI@ATP to Pb2+ was proportional to pH in the range of 2–5.5. The presence of Na+, Mg2+, and Ca2+ can inhibit the removal of Pb2+, and Ca2+ has the strongest inhibition effect on the removal of Pb2+. The removal mechanism of Pb2+ by nZVI@ATP obtained from SEM-EDS, BET, XRD, FTIR and XPS included reduction, precipitation, and the formation of complexes.

Compositions of microbial communities associated with blooms of algae in a storage reservoir in Macau, China were investigated between 2013 and 2016. Algae were enumerated by visible light microscopy. Profiles of organisms in water were examined by 16S rRNA sequences and viral metagenomics, based on next generation sequencing. Results of 16S rRNA sequencing indicated that majority of the identified organisms were bacteria closely related to Proteobacteria, Cyanobacteria, Verrucomicrobia, Bacteroidetes, and Actinobacteria. Metagenomics sequences demonstrated that the dominant virus was Phycodnavirus, accounting for 70% of the total population. Patterns of relative numbers of bacteria in the microbial community and their temporal changes were determined through alpha diversity indices, principal coordinates analysis (PCoA), relative abundance, and visualized by Venn diagrams. Ways in which the bacterial and viral communities are influenced by various water-related variables were elucidated based on redundancy analysis (RDA). Relationships of the relative numbers of bacteria with trophic status in a reservoir used for drinking water in Macau, provided insight into associations of Phycodnavirus and Proteobacteria with changes in blooms of algae.

Mangroves are intertidal extreme environments with rich microbial communities. Actinobacteria are well known for producing antibiotics. The search for biosynthetic potential of Actinobacteria from mangrove environments could provide more possibilities for useful secondary metabolites. In this study, whole genome sequencing and MS/MS analysis were used to explore the secondary metabolite production potential of one actinobacterial strain of Streptomyces olivaceus sp., isolated from a mangrove in Macau, China. The results showed that a total of 105 gene clusters were found in the genome of S. olivaceus sp., and 53 known secondary metabolites, including bioactive compounds, peptides, and other products, were predicted by genome mining. There were 28 secondary metabolites classified as antibiotics, which were not previously known from S. olivaceus. ISP medium 2 was then used to ferment the S. olivaceus sp. to determine which predicted secondary metabolite could be truly produced. The chemical analysis revealed that ectoine, melanin, and the antibiotic of validamycin A could be observed in the fermentation broth. This was the first observation that these three compounds can be produced by a strain of S. olivaceus. Therefore, it can be concluded that Actinobacteria isolated from the mangrove environment have unknown potential to produce bioactive secondary metabolites.

The Beijing-Tianjin-Hebei (BTH) region, with its complex terrain, has serious issues with air pollution. The northern and western parts of the BTH region are surrounded by the Yan Mountains and Loess Plateau (LP), and the south-central part of that region is a large open plain. Such special geographic configuration is prone to result in a concentrated pollution belt along the north-to-south direction on the eastern margin of the plateau, in addition to the influence of pollutant-emission sources and population distribution. In this study, based on an original adaptive nudging constraint method, we quantitatively analyzed the differences in the influence of emission sources under different dynamic and thermal conditions in the BTH region, which is impacted by a special large-scale leeward slope terrain. The mechanism of air pollution vulnerability and the comprehensive effects of terrain−meteorological conditions on air pollution in the BTH region were also discussed. The results indicated that the atmospheric diffusion conditions on the eastern side of the plateau were poor, and a sub-synoptic-scale “vortex sequence”, which was composed of a series of linked vortices, was identified. The corresponding atmospheric pollution convergence line stretched from Beijing to Hebei to Northern Henan in the lower atmosphere. On the eastern edge of the plateau, a “warm cover” formed by a temperature anomaly and a downdraft impeded the vertical diffusion of pollutants. Therefore, pollutants tended to converge at the eastern edge of the plateau, and the pollution belts would move longitudinally north and south along the topography of the eastern slope when south-westerly and north-easterly winds alternated. The movement generated a “train” of pollutants that were transported on the eastern edge of the plateau, which then caused air pollution to persist there. Such terrain−meteorological conditions amplified the effects of emissions by an average of 50% to 150% in the region, leading the eastern side of the LP to become a “naturally vulnerable region” to haze pollution.

Since mid-2015, numerous outbreaks of hydropericardium-hepatitis syndrome (HHS), which is caused by a novel fowl adenovirus serotype 4 (FAdV-4), have been reported in chickens in parts of China, thereby causing huge economic losses to the poultry industry. Thus, an effective vaccine to control the further spread of infections with this hyper-virulent FAdV-4 is imperative. In this study, we isolated a novel FAdV-4 strain SDJN0105 from a broiler farm with HHS disease in Shandong Province. Pathogenicity was evaluated by the observation of clinical symptoms, necropsy changes, and pathological tissue sections after oral and intramuscular (IM) infection of Specific pathogen free (SPF) chickens. The chickens infected by IM injection all died within three days, and chickens infected via the oculonasal route died within five days post-infection (dpi). Histopathological examination revealed that the pathology was confined to heart, liver, spleen, lung, kidney, and particularly the liver. Irrespective of the inoculation route, the highest viral DNA copy numbers were detected in the livers of infected chickens. The mRNA expression levels of IL-1β, IL-6, IL-8, IFNs, TNF-α, Mx, and OASL were significantly upregulated during the viral infection. In addition, an inactivated oil-emulsion FAdV-4 vaccine was developed. The vaccine could provide full protection for SPF chickens against a lethal dose of the FAdV-4 strain SDJN0105 and a high level of antibodies. These results improve our understanding of the innate immune responses in chickens infected with FAdV-4 and the pathogenesis of FAdV-4 caused by host factors, and the developed FAdV-4 vaccine is promising as a drug candidate for the prevention and reduction of the spread of HHS in poultry in China.

In view of the problem that the weight value given by the previous state evaluation method is fixed and single and cannot analyze the influence of the weight vector deviation on the evaluation result, a method based on the weight space Markov chain and Monte Carlo method (Markov chains Monte Carlo, MCMC) is proposed. The sampling method is used for evaluating the condition of high-voltage cables. The weight vector set obtained by MCMC sampling and the comprehensive degradation degree of the high-voltage cable sample are weighted and summed then compared in pairs to obtain the comprehensive degradation degree result. The status probability value and overall priority ranking probability of the object to be evaluated are obtained based on probability statistics, and the order of maintenance is determined according to the status probability value and the ranking result. It is realized that the cable line that needs to be identified in the follow-up defect is clarified according to the evaluation result. This is helpful for operational and maintenance personnel to more accurately implement the maintenance plan for the cable and improve the operational and maintenance efficiency.

We present the design of a power management integrated circuit that processes harvested energy from radio frequency waves and piezoelectric vibrations. The rectification of piezoelectric and RF sources has a power conversion efficiency (PCE) of 87.73% and 74.70%, respectively. The asynchronous and microcontroller-less integrated circuit (IC) is designed to be low power, so the bulk of the harvested energy goes to three loads. The output peak powers of 111 μW, 156 μW, and 128 μW will be sufficient to run small devices for RF communication systems.

In this paper, we proposed a novel reversible data hiding method in encrypted image (RDHEI), which is based on the compression of pixel differences. In the proposed method, at the content owner’ side the image is divided into non-overlapping blocks, and a block-level image encryption scheme is used to generate the encrypted image, which partially retains spatial correlation in the blocks. Due to the spatial correlation, in each block the pixels are highly likely to be similar. Therefore, the pixel differences in all blocks are concentrated in a small range and can be compressed. By the compression of pixel differences, the data hider can vacate the room to accommodate secret data in the encrypted image without losing information. At the receiver’s side, the receiver can obtain secret data or retrieve the original image using different keys with no error. The experimental results demonstrate that, compared with existing methods, the proposed method can achieve a higher capacity and visual quality.

In this study, we attempted to investigate the general statistical association of air pollution with the cardiovascular and respiratory mortality of the elderly in Hong Kong. Based on six years of measurements including the major air pollutant concentrations (PM10, SO2, NO, NO2, O3, CO), ambient temperature, and mortality (respiratory, cardiovascular) between 2005 and 2010, correlation analysis was carried out in annual, monthly and weekly time scales. From an annual perspective, it was found that the air pollution species may pose a constant effect on the respiratory and the cardiovascular mortality during the studied period since the elderly mortality rates and the air pollution annual concentrations show obvious constant trends. From a monthly time scale, it was found that NO2 and CO have high positive cross correlation with the respiratory mortality of the following 1 to 2 months. In addition, PM10 and CO also have similar delayed influence on the cardiovascular mortality. Among these four pollutants, only CO was found to exhibit high statistical association in the weekly time scale and it is most related to the cardiovascular mortality of the week after next. Therefore, it was concluded that the effect of air pollution on the elderly mortality of Hong Kong should be cumulative. This study implies that the establishment of weekly or monthly air quality indices is necessary for health implications.