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Cold surges represent one of the most hazardous weather events impacting the Yellow and Bohai Seas. The current limited comprehension of their wind impacts motivated the present study. The investigation delved into the spatial and temporal features of high winds during cold surges from 1960 to 2021, scrutinizing trends in interannual and monthly variations, as well as their relevance with large-scale climate patterns. The results revealed an overall declining trend in wind impacts at an annual rate of ∼ 8%. The decline was primarily attributed to the reduction in high wind duration and was irrelevant to alterations in wind speed. Spatial analysis revealed a distinct bimodal pattern, with a short-lived but enhanced center in Liaodong Bay and a longer-lasting albeit less intense center in the central Yellow Sea. Monthly variabilities were characterized by the formation, intensification, and dissipation of this bimodal pattern. Wind impacts showed a tendency to decrease substantially during late autumn and to slightly increase in the spring season. Furthermore, empirical orthogonal function (EOF) analysis revealed modes of variation in high winds, with the primary modes closely linked to the intensity of the Siberian High (SH) and East Asian Winter Monsoon (EAWM). Increased incidence of cold surges and stronger high wind impacts were associated with SH + and EAWM+. Additionally, cold surge frequency and associated high winds showed moderate but statistically significant relevance to the Arctic Oscillation (AO), with more frequent and intensified wind impacts observed during AO-. Marginal influence from the El Niño-Southern Oscillation (ENSO) was also noted, with a positive (negative) ENSO phase corresponding to less (more) frequent cold surges but more (less) intense high wind impacts. [ABSTRACT FROM AUTHOR]

In order to examine the distribution and accumulation patterns of microplastics (MPs) in conjunction with effective microorganisms (EMs), as well as their collective impact on oxidative stress, inflammatory damage, and immune regulation in juvenile Micropterus salmoides (M. salmoides), a series of exposure (96 h) and depuration (D 96 h) experiments with MPs and EMs were conducted. The results showed that the highest abundance of MPs appeared in the biological samples in the EMs with MPs group (EP group) at 96 h. The highest abundance of MPs in the sediment occurred in the MPs group (P group) at 96 h with 507 items/mL and in the water samples at 48 h in the P group with 141.75 items/mL. The addition of EMs increased the content of MPs in the intestine of M. salmoides and reduced the MPs content in the water and sediment. The expression of Nrf2 and SOD in the intestinal in the EP group compared with the control group (C group) showed significant differences at 48 h. After D 96 h, the expression of SOD and GPX in the MPs + EMs (P-E) (EP group) was significantly higher than the C group. IL-8 and TNF-α in the intestine and gill in the P group were significantly higher than the C group at 96 h, and it began to show a decreasing trend after D 96 h. These results revealed that the addition of EMs increased the enrichment of MPs in M. salmoides, while it promoted the recovery of M. salmoides from adverse effects during the depuration phase. These findings can help us understand the responses of MPs with microorganisms in aquaculture. [ABSTRACT FROM AUTHOR]

The design of diatomic catalysts with uniformly dispersed metal atoms is expected to improve catalytic performance, which is conducive to the intensive comprehending of the synergistic mechanism between dual-metal sites for the oxygen evolution reaction (OER) at the atomic level. Herein, we design a strategy to immobilize bimetallic Fe-Co atoms onto nitrogen-doped graphene to obtain a diatomic catalyst (DA-FC-NG) with FeN3-CoN3 configuration. The DA-FC-NG shows excellent OER activity with a low overpotential (η10 = 268 mV), which is superior to commercial iridium dioxide catalysts. Theoretical calculations uncover that the excellent activity of DA-FC-NG is due to the interaction between Fe and Co diatoms, which causes charge rearrangement and induces the adsorption of intermediates on the Fe–O–Co bridge structure, thus improving the catalytic OER performance. This work is of great significance for the design of highly active diatomic catalysts to replace noble metal catalysts for energy-related applications. [ABSTRACT FROM AUTHOR]

As a four-electron transfer reaction, oxygen evolution reaction (OER) is limited by large overpotential and slow kinetics. Here, we in-situ synthesized two-dimensional (2D) Ni-Fe metal-organic framework nanosheets on nickel foam (NixFe-TPA/NF, TPA = terephthalic acid) for oxygen evolution in alkaline and alkaline seawater electrolytes. In 1 M KOH, Ni3Fe-TPA/NF shows a low overpotential (η10) of 189 mV at 10 mA·cm−2 and an ultra-low overpotential of only 260 mV at 500 mA·cm−2. In alkaline seawater, Ni3Fe-TPA/NF still provides impressive OER performance, with an η10 of 265 mV. In-situ Raman characterization results show that the phase transition occurs during the OER, and Ni3FeOOH with more oxygen vacancies is in-situ formed, reducing the OER energy barrier. Density functional theory (DFT) reveals that the synergy between Ni and Fe reduces the energy barrier and accelerates the rate-determining step. In addition, the ultra-thin 2D sheet structure and the close combination of Ni3FeOOH and highly conductive NF support ensure the high catalytic OER activity. Therefore, the surface reconstruction and structural modification strategy can be used to design and prepare high-performance OER electrocatalysts for energy-related applications. [ABSTRACT FROM AUTHOR]

Temperature is one of the key environmental factors in Litopenaeus vannamei (Boone, 1931) culture, affecting the growth and survival of shrimp. Our previous study found that stress resistance related pathways (endoplasmic reticulum stress, immune, and apoptosis) were significantly increased under low temperature stress, but studies about their regulation are still limited. Therefore, the histological changes and the genes expression related to the above pathways in L. vannamei were examined under conditions of cooling from 28 to 13 °C with a cooling rate of 2.5 °C /2 h and then maintained at 13 °C for 12 h. The results showed that the gill and intestine of L. vannamei were obviously damaged after low temperatures stress, while the muscle tissue of shrimp did not change significantly. Most of the relative expression of unfolded protein response (UPR) pathway (GRP78, ATF6, IRE1, and PERK), immune (proPO), as well as apoptosis (CASP3) gene in each tissue were significant changed after cooling. The results suggested that muscle may be more structurally stable than other tissues in shrimp. The stress resistance mechanisms could be activated under low temperatures, and 18 °C may be the critical point for L. vannamei to adjust its anti-stress system to maintain organism homeostasis. Moreover, the results also reflect that the stress resistance system is tissue-specific under low temperature stress in L. vannamei. This study can enrich our understanding of the responses at the histological and genetic levels in shrimp under low temperature stress, helping to promote further development of shrimp culture industry. [ABSTRACT FROM AUTHOR]

Dual-metal catalysts with synergistic effect exhibit enormous potential for sustainable electrocatalytic applications and mechanism research. Compared with mono-metal-site catalysts, dual-metal-site catalysts exhibit higher efficiency for the oxygen evolution reaction (OER) due to reduced energy barrier of the process involving proton-coupled multi-electron transfer. Herein, we construct dual-metal Fe-Co sites coordinated with nitrogen in graphene (FeCo-NG), which exhibits high OER performance with onset overpotential of only 126 mV and Tafel slope of 120 mV·dec−1, showing that the rate-determining step is controlled by the single-electron transfer step. Theoretical calculations reveal that the FeN4 site exhibits lower OER overpotential than the CoN4 site due to appropriate adsorption energy of OOH* on the former, while the O* adsorbed on the adjacent Co site could stabilize the OOH* on the FeN4 site through hydrogen bond interaction. [ABSTRACT FROM AUTHOR]

Oxygen evolution reaction (OER) plays an important role in many energy conversions and storage technologies, such as water splitting, rechargeable metal air batteries, renewable fuel cells, and electrocatalytic carbon dioxide reduction and nitrogen reduction, but its slow kinetics and high overpotential seriously affect the energy efficiency. Fabrication of high-performance and well-stocked OER catalysts is the key to the large-scale implementation of these energy-related technologies. Two-dimensional (2D) materials get a lot of attention as OER catalysts due to their large specific surface area, abundant active sites, and adjustable structures and compositions. Here, an overview is presented for the latest achievements in design and synthesis of 2D materials (including layered double hydroxides, metal-organic frameworks and their derivatives, covalent-organic frameworks, graphene, and black phosphorus) for the OER, emphasizing novel strategies (including metal/nonmetal doping, defect engineering, interface engineering, lattice strain, and fabrication of heterojunction) for achieving high electrocatalytic activity. Peculiarly, the structure-function relationship is analyzed in detail to gain deeper insight into the reaction mechanism, which is crucial to rational design of more high-performance 2D materials for the OER. Finally, the remaining challenges to improve the OER performance of 2D electrocatalysts are put forward to indicate possible future development of 2D materials. [ABSTRACT FROM AUTHOR]

Microplastics can accumulate residual drugs and heavy metals in the environment and accumulate through the layers of the food chain, ultimately causing harm to human health. The pollution of microplastics in the freshwater environment is becoming more and more serious, which directly affects the safety of aquatic organisms. This experiment studied the effects of single and composite microplastics and Cd on the tissue damage, antioxidant, and immune response of juvenile Channa argus. Microplastics with different diameters of 80 nm, 0.5 μm (200 μg/L), and Cd (50 μg/L) were used for exposure, and four sampling points were set for 24 h, 48 h, 96 h, and clear 48 h. Under different treatments, a certain degree of gill tissue damage can be found in 96 h. Microplastics and Cd can cause oxidative stress and affect the antioxidant status, and the impact of 0.5-μm microplastics is stronger than that of 80-nm microplastics. There is an antagonistic effect between the two microplastics and Cd during compound exposure, but the activity of CAT shows a synergistic effect. Microplastics and Cd affect the expression of immune-related genes to varying degrees. When exposed together, the expression of HSP70 gene all showed mutual antagonism, while the expression of IL-1β gene was different. The expression of the MT gene can infer the ability of microplastics to accumulate Cd, and microplastics with a small diameter of 80 nm have stronger enrichment capabilities. [ABSTRACT FROM AUTHOR]

An increasing number of marine structures have been built for coastal protection and marine development in recent years, and wind, which is crucial to marine structures, should be analyzed. Therefore, typhoon frequency, wind climate, wind energy assessment, and extreme wind speed in the South China Sea (SCS) are investigated in detail in this study. The data are obtained from the China Meteorological Administration, the European Centre for Medium-range Weather Forecasts, and the National Centers for Environmental Prediction. The offshore wind energy potential is analyzed at five sites near the coast. The spatial and monthly frequencies of tropical cyclones for different intensity categories are analyzed. The extreme wind speed is fitted by five distribution models, and the generalized extreme value (GEV) distribution is selected as the most suitable function according to the goodness of fit. The spatial distributions of extreme wind speeds in the SCS are plotted on the basis of the GEV distribution and ERA5 data sets. The influences of the distribution models and data sets on the calculated results are discussed. Moreover, the monthly extreme wind speed and comparison with the results of previous studies are analyzed. This study provides a reference for the design of wind turbines. [ABSTRACT FROM AUTHOR]

In this work, we synthesized a series of 20% Ni-x% Cu/Al2O3 catalysts containing various Cu loading by the impregnation method and investigated their catalytic performance in the amination of diethylene glycol (DEG) with tertiarybutylamine (TBA) to tertiarybutylaminoethoxyethanol (TBEE). A variety of characterization techniques including XRD, TEM, BET, XPS, H2-TPR, NH3-TPD, CO2-TPD were applied. The promotional influence of Cu on the catalytic performance of Ni/Al2O3 catalyst was studied, and the optimal addition of Cu was obtained. Indeed, we found that Ni–Cu alloy was formed after reduction of the Ni–Cu/Al2O3 catalysts. Due to the strong interaction between Cu and Ni, Cu could improve the reducibility of NiO and the dispersion of Ni species on the catalyst surface, which were critical factors for higher reactivity of the bimetallic Ni–Cu/Al2O3 catalysts. Moreover, the influence of catalyst reduction temperature and reaction temperature were examined. When operating at 230 °C, the 20% Ni-10% Cu/Al2O3 catalyst reduced at 500 °C for 2 h exhibited superior catalytic performance in this reaction. Ni-Cu/Al2O3 catalyst was found to be an effective catalyst for catalytic amination of diethylene glycol with tertiarybutylamine. [ABSTRACT FROM AUTHOR]

The Cu/ZnO/Al2O3 catalysts prepared by co-precipitation method were used for the hydrogenation of methyl benzoate to benzyl alcohol. These catalysts were characterized at various stages of preparation by nitrogen adsorption-desorption, X-ray diffraction (XRD), hydrogen temperature-programmed reduction (H2-TPR), and X-ray photoelectron spectroscopy (XPS). The experimental results show that the addition of ZnO to the catalyst greatly improves the selectivity of benzyl alcohol. When the Cu/Zn/Al molar ratio is 2:2:1 and the calcination temperature of the catalyst is 650 °C, the catalyst exhibits very highly catalytic performance. In addition, the effects of reaction temperature, pressure and time were also investigated during the hydrogenation of methyl benzoate to benzyl alcohol. When the methyl benzoate was hydrogenated over this catalyst at 160 °C and 7 MPa of H2 for 10 h, the conversion of methyl benzoate can reach 93.89% and the selectivity of benzyl alcohol is 88%. This effectively catalytic performance can be attributed to the presence of highly dispersed and stable metallic copper nanoparticles, and the weak acidity of the catalyst surface. Besides, the reaction pressure and temperature play a crucial role in the conversion of methyl benzoate and the selectivity of benzyl alcohol.Graphical Abstract: Application of Cu/ZnO/Al2O3 catalyst in hydrogenation of methyl benzoate to benzyl alcohol. [ABSTRACT FROM AUTHOR]

Abstract: In this work, titanium-doped mesoporous Al2O3 (γ-Ti-Al2O3) was prepared by an evaporation-induced self-assembly method and used as a carrier of Ba/γ-Ti-Al2O3 catalyst to catalyze the aldol condensation of methyl acetate with formaldehyde to methyl acrylate in a fixed-bed reactor. The catalysts were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, N2 adsorption-desorption, pyridine absorption performed via Fourier transform infrared spectroscope (Py-IR), and NH3 and CO2 temperature-programmed desorption (NH3 and CO2-TPD). Experimental results indicated that the doping of the titanium species into the frame work of mesoporous Al2O3 (γ-Ti-Al2O3) had a significant influence on the catalytic activity via modifying the acid-base surface properties of the catalyst. Furthermore, the Ba/γ-Ti-Al2O3 catalyst demonstrated excellent catalytic performance, with a methyl acetate conversion rate of 50% and methyl acrylate selectivity up to 90.2%. Compared with the Ba/Al2O3 catalyst, the Ba/γ-Ti-Al2O3 catalyst had better catalytic activity, stability and potential for practical application, which was likely due to an increased number of Lewis acid sites, especially the medium acid sites.Graphical Abstract: Barium supported mesoporous γ-Ti-Al2O3 catalyst was found to be an effective catalyst for vapor phase aldol condensation of methyl acetate with formaldehyde. [ABSTRACT FROM AUTHOR]

A series of Ce-SBA-15 mesoporous materials were synthesized through a direct hydrothermal method and further impregnated with different amounts of Cs. The catalysts were characterized by XRD, XPS, SEM, NH3-TPD, CO2-TPD, FT-IR and N2 adsorption-desorption isotherm analyses. The XRD and N2 adsorption-desorption isotherm results showed that the Ce successfully incorporated into the framework of SBA-15, which was favorable for the generation of mesoporous materials with high specific surface areas, large pore volumes and narrow pore size distribution. The incorporation of Ce changed the acid-base properties of the support and promoted the dispersion of Cs species. NH3-CO2 TPD results indicated that a number of medium-strong acid and base sites existed in the 10Cs/Ce-SBA-15(10) catalyst, which made it suitable as a catalyst for the aldol condensation of methyl acetate with formaldehyde to prepare methyl acrylate. [ABSTRACT FROM AUTHOR]

Vapor phase aldol condensation of methyl acetate with formaldehyde was first studied over AlO with different calcination temperatures and AlO-supported barium with different amounts of barium catalysts. The catalysts were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, N adsorption-desorption, the pyridine absorption performed via Fourier transform infrared spectroscope, NH and CO temperature-programmed desorption. The results indicated that the calcination temperature affected the strength and the number of surface acid and base sites over the alumina catalysts. In addition, the moderate Lewis acid and weak base sites were critical to promote this aldol condensation reaction. Adding barium species, which could effectively modified the acid-base properties of AlO, clearly improved the catalytic activity and selectivity. The stability and regeneration of the optimum catalyst were also investigated and did not exhibit an obvious decrease in efficiency. Graphical Abstract: AlO-supported barium catalyst was found to be an effective catalyst for vapor phase aldol condensation of methyl acetate with formaldehyde as a result of the appropriate intensity of acid and base. [ABSTRACT FROM AUTHOR]

The Prins condensation of isobutylene with formaldehyde over scillica-supported silicotungstic acid catalysts has been investigated. The catalysts were characterized via XRD, FTIR, Py-IR, NH-TPD and TG-DSC techniques. It was found that the catalyst with 5 wt% silicotungstic acids loading exhibited the best isobutene conversion and isoprene selectivity, and excessive silicotungstic acid was not conducive to improve the catalytic performance. It was proposed that the concentration and strength of acid sites could affect the catalytic properties. An appropriate amount of weak Lewis acid sites were the active site for the condensation of isobutene with formaldehyde, and the medium-strong acid sites could cause the side reactions and coke deposits. [ABSTRACT FROM AUTHOR]

In this paper, a MEMS electrothermal microgripper is introduced, analyzed and tested. The microgripper has been fabricated using the PolyMUMPs surface micromachining process. Analytical models were established based on the electro-thermal and thermo-mechanical analysis to describe the mechanical performances of the microgripper. Axial deformations including first-order nonlinear strain-displacement relations are also included to account for the presence of thermal loading. The materials parameters that significantly affect the performance of the microgripper are discussed, including the thermal conduction, convective and temperature-dependent resistivity. The experimental results show that input voltages below 14 V are required for the microgripper to achieve the jaws deflection in 9.1 μm. Both the experimental and analytical results are in good agreement with the results of modeling. To demonstrate the reliability of the microgripper, the repeatability and reproducibility of jaws gap were tested. [ABSTRACT FROM AUTHOR]

Cu/SiO catalysts that contain copper phyllosilicate, were successfully prepared using the ammonia-evaporation method. The catalysts were characterized via XRD, ICP, BET, FTIR, TPR, XPS, NH-TPD and FTIR of Pyridine Adsorption techniques. The results demonstrated that the formation of the copper phyllosilicate species significantly affected the structural properties and caused the CuO nanoparticles to become highly dispersed, and the copper phyllosilicate would provide access to the Lewis acidic Cu species. It was found that the catalyst with a 23.7 wt% copper loading exhibited the best ethanol conversion and ethyl acetate selectivity. When compared to a catalyst with the same copper loading which was prepared with the impregnation method, the higher activity and selectivity of catalysts might be ascribed to the homogenous distribution of copper nanoparticles, which was the active site for the dehydrogenation, and the amount of Lewis acidic Cu sites active for esterification. The synergetic effect between the Cu and Lewis acidic sites was the key factor to achieve direct transformation of ethanol to ethyl acetate. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Pd/AlO catalysts were prepared via colloid deposition and the performance of the catalysts was examined in the selective hydrogenation of maleic anhydride to succinic anhydride. When the reaction was carried on in a batch system with 1,4-dioxane as the solvent (353 K and 1.0 MPa), high conversion of maleic anhydride (>98%) and high selectivity (>99%) for succinic anhydride were observed after 5 h. The as-prepared Pd/AlO catalyst also showed excellent performance in solvent-free system and fixed-bed systems. The maleic anhydride (MA) conversion was greater than 98%, and high selectivity (>99%) for succinic anhydride was obtained after 1600 h in a fixed bed reacter. The results showed that the activity of the Pd/AlO catalysts was excellent due to its high active surface area. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Pillared layered MCM-36 zeolite (MCM-36-I) was successfully synthesized from MCM-56 precursor with polymeric silica as the pillaring agent. The structure and properties of the sample was characterized by means of N adsorption, XRD, TEM and IR spectroscopy of pyridine adsorption. The results showed that MCM-36-I has higher external surface area and more Brönsted acidic sites on external surface than that on the MCM-36 sample (MCM-36-II) which was synthesized from layered MCM-22 precursor. The catalytic properties of these samples were tested for alkylation of benzene with isopropanol. Compared with MCM-36-II catalyst, MCM-36-I showed higher conversion of benzene and selectivity to cumene. This should be mainly assigned to the fact that MCM-36-I possesses larger amount of accessible Brönsted acid sites which located on the external surface than that of MCM-36-II. [ABSTRACT FROM AUTHOR]

The reaction of direct transformation of ethanol to ethyl acetate was investigated on reduced Cu/ZrO catalysts prepared by a co-precipitation procedure. The catalytic performances of these Cu-Zr mixed oxides were considerably influenced by changing the molar ratio of Cu to Zr. The highest selectivity to ethyl acetate was found over Cu/ZrO(1) catalyst (molar ratio of Cu to Zr was 1). A variety of characterization techniques, such as N adsorption, XRD, XPS, TPR and NH-TPD were carried out on the catalysts. The results revealed that the presence of a certain amount of Cu species may play very important role in improving the selectivity to ethyl acetate of the Cu/ZrO catalysts. [ABSTRACT FROM AUTHOR]

The catalytic properties of supported Cu/SBA-15 catalysts prepared by the ion-exchange method were investigated for the hydrogenolysis of glycerol in a fixed-bed tubular reactor. The Cu/SBA-15 catalyst performed higher selectivity to 1,2-propanediol and high stability. We propose that the larger specific surface area and the ordered mesoporous channels of SBA-15 may play important roles in stabilizing highly dispersed copper species, and forming an active and durable catalyst for the title reaction. [ABSTRACT FROM AUTHOR]