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Simple Summary: The wild population of Brachymystax tsinlingensis is a Grade II protected species in China. This population faces slow growth, harsh habitats, serious individual miniaturization, and a low survival rate of fry during its early developmental stage. To improve the aquaculture efficiency of this species, and thus increase the survival rate, protect species resources, and enrich species numbers, the present study was conducted to investigate the changes in intestinal tissue structure, digestive enzymes, malondialdehyde content, and antioxidant enzyme activities and their patterns during the early developmental stage of Brachymystax tsinlingensis. This information can be applied to increase the survival rate of fry, protect the species resources, and enrich the species' quantity. This work explores the digestive system characteristics of Brachymystax tsinlingensis during early developmental stages and aims to solve the problem of high lethality of fry during the transgression period, which is crucial for the artificial propagation and population conservation of endangered fishes. This study was carried out on intestinal tissue, digestive enzymes, and antioxidant enzyme activities in the early development stage of Brachymystax tsinlingensis. Ten random samples during endogenous nutrition (7, 10, and 11 days after hatching), mixed nutrition (13 and 19 DAH), and exogenous nutrition (31, 33, 39, 45, and 73 DAH) were collected by histological and biochemical analysis methods. The results showed that the intestine of Brachymystax tsinlingensis already has four layers initially at 7 DAH, and the intestinal gland tissue is evident at 73 DAH. The contents of total protein (TP) and the activities of lipase (LPS) and trypsin (TPS) were maximal at 39 DAH, and the activities were 3.20 ± 0.26 mg/mL, 2.52 ± 0.69 U/g, and 2717.45 ± 295.26 U/mg, respectively. Catalase (CAT) and glutathione peroxidase (GSH-PX) activities both showed the lowest values at 39 DAH, which were 0.57 ± 0.11 U/mg and 3.35 ± 0.94 U/mg, respectively. The activity of amylase (AMS) and the content of malonaldehyde (MDA) increased, and the highest values were reached at 45 DAH (1.32 ± 0.41 U/mg) and 73 DAH (1.29 ± 0.43 nmoL/mg), respectively. Superoxide dismutase (SOD) and GSH-PX activities both showed a peak value at 7 DAH (126.58 ± 20.13 U/mg and 6.47 ± 1.86 U/mg). Overall, the changes in intestinal tissue, digestive enzymes, and antioxidant enzyme activities at 39 DAH of Brachymystax tsinlingensis are inseparable from different vegetative stages during the developmental period, and these results can provide a reference for the proliferation and cultivation of Brachymystax tsinlingensis resources. [ABSTRACT FROM AUTHOR]

Simple Summary: Altering aquatic environments with global warming can have a profound impact on fish species. This study employed transcriptome sequencing to analyze alternative splicing in the gills of largemouth bass after heat stress. We observed an increase in alternative splicing events (674) and differential alternative splicing genes (517). Enrichment analysis revealed significant associations with immune-related gene ontology (GO) terms and KEGG pathways, notably necroptosis, apoptosis, and C-type lectin receptor signaling. These results emphasize that some RNA splicing-related genes are involved in the response of largemouth bass to high temperatures. Temperature is one of the critical factors affecting the physiological functions of fish. With ongoing global warming, changes in water temperature have a profound impact on fish species. Alternative splicing, being a significant mechanism for gene expression regulation, facilitates fish to adapt and thrive in dynamic and varied aquatic environments. Our study used transcriptome sequencing to analyze alternative splicing in largemouth bass gills at 34 °C for 24 h. The findings indicated an increase in both alternative splicing events and alternative splicing genes after high temperature treatment. Specifically, the comparative analysis revealed a total of 674 differential alternative splicing events and 517 differential alternative splicing genes. Enrichment analysis of differential alternative splicing genes revealed significant associations with various gene ontology (GO) terms and KEGG pathways, particularly in immune-related pathways like necroptosis, apoptosis, and the C-type lectin receptor signaling pathway. These results emphasize that some RNA splicing-related genes are involved in the response of largemouth bass to high temperatures. [ABSTRACT FROM AUTHOR]

With the expanding application of lightweight wooden structures in modern construction, the load-bearing capacity of ordinary triangular single-span wooden trusses limits the applicability of lightweight wooden structures. As a result, triangular multi-span wooden trusses have emerged to replace single-span wooden trusses. In practice, multi-span wooden trusses are composed of multiple single-span lightweight wooden trusses, with connections between members using metal plates, a field that has been relatively well researched. However, connections between spans are primarily made with nails in actual engineering, and there has been little research on the use of wooden pins to connect multi-span wooden trusses. To study the mechanical performance of multi-span wooden trusses connected by wooden pins, this paper innovatively combines existing equipment with a self-designed pulley assembly device to conduct a continuous static full-scale loading test on double-span wooden trusses connected by wooden pins of three different diameters. We comprehensively evaluate which type of wooden pin is more suitable for triangular multi-span wooden trusses. The results indicate that the 16 mm diameter wooden pin provides the best energy dissipation performance for connected beam trusses. The 20 mm diameter wooden pin offers the best performance stability. The 20 mm diameter wooden pin also demonstrates a good load-bearing capacity and resistance to deformation. Overall, the 20 mm diameter wooden pin exhibits the best connection performance in triangular beam trusses. [ABSTRACT FROM AUTHOR]

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]

We study the relations of multiple t -values of general level. The generating function of sums of multiple t -(star) values of level N with fixed weight, depth and height is represented by the generalized hypergeometric function 3 F 2 , which generalizes the results for multiple zeta(-star) values and multiple t -(star) values. As applications, we obtain formulas for the generating functions of sums of multiple t -(star) values of level N with height one and maximal height and a weighted sum formula for sums of multiple t -(star) values of level N with fixed weight and depth. Using the stuffle algebra, we also get the symmetric sum formulas and Hoffman's restricted sum formulas for multiple t -(star) values of level N. Some evaluations of multiple t -star values of level 2 with one–two–three indices are given. [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]

Foundation scour is the erosion of sediments around pile foundations by wave and current in offshore wind energy. This phenomenon destabilizes foundations and poses a threat to pile safety. Therefore, scour protection becomes a crucial challenge in offshore wind projects. This paper reviews and synthesizes recent publications and patented technologies related to scour protection. Considering the primary engineering concerns, the paper proposes design principles for effective scour protection schemes to standardize evaluation criteria. These principles prioritize efficacy, independence, and cost-efficiency, enabling the analysis of scour protection scheme applicability. In addition, this paper summarizes and describes common protection schemes in the literature. The effectiveness of their protection is analyzed and summarized, and their economic and performance independence is evaluated. This paper categorizes flow-altering scour protection schemes found in the literature. Based on a comprehensive understanding of the mechanisms and engineering requirements of scour protection, the paper proposes a focus on determining the erosion reduction rate curve ( E p − U / U c curve) as a key criterion for evaluating the effectiveness of protection schemes under varying flow velocities and the erosion reduction rate of scour protection schemes under extreme conditions. The study highlights the necessity of establishing a comprehensive design evaluation methodology, which is crucial for addressing the significant challenges related to scour encountered in offshore wind power projects. [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]

Covalent organic frameworks (COFs) are crystalline organic porous polymers that can be precisely integrated by building blocks to achieve pre‐designed composition, components, and functions, making them a powerful platform for the development of molecular devices in the field of electrocatalysis. The precise control of channel/dopant positions and highly ordered network structures of COFs provide an ideal material system for the applications of advanced electrocatalysis. In this paper, the topological structure design and synthesis methods of COFs are reviewed in detail, and their design principles are deeply analyzed. In addition, the applications of COFs and their derivatives in the field of electrocatalysis are systematically summarized and the optimization strategies are proposed. Finally, the application prospects of COFs and their derivatives in electrocatalysis and the challenges that may be encountered in the future are prospected, providing helpful guidance for future research. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) are porous organic materials with well‐defined and uniform structure. The material is an excellent candidate as a solid adsorbent for iodine adsorption. In the present study, we report the synthesis of COF with porphyrin moiety, TF‐TA‐COF, by solvothermal reaction, which was characterized by XRD, solid‐state 13C NMR, IR, TGA, and nitrogen adsorption‐desorption analysis. TF‐TA‐COF showed a high specific surface area of 443 m2 g−1, and exhibited good adsorption performance for iodine vapor, with an adsorption capacity of 2.74 g g−1. XPS and Raman spectrum indicated that a hybrid of physisorption and chemisorption took place between host COF and iodine molecules. The electric properties of iodine‐loaded TF‐TA‐COF were also studied. After doped with iodine, the conductivity of the material increased by more than 5 orders of magnitude. The photoconductivity of I2‐doped COF was also studied and TF‐TA‐COF showed doping‐enhanced photocurrent generation. [ABSTRACT FROM AUTHOR]

In this study, laboratory experiments were conducted to investigate the influence of changes in storm wave height and water level on beach response in a medium-scale wave flume. A schematic storm was simulated (rising, apex, and waning phases). A non-intrusive photogrammetric method was used to collect high-resolution and synchronous data regarding the free surface water elevation and bed level, from which shoreline location, sandbar position, cross-shore sediment transport rates, and nonlinear wave parameters were derived. The cross-shore sediment transport was in agreement with previous laboratory measurements, including the monotonous exchange from foreshore erosion to shoaling zone accretion in most stages of the storm simulation. The surf zone was the main region supplying sediment for beach morphology modification and sandbar generation. The degree of storm erosion was not completely determined by the largest wave height and water level or the cumulative wave power of the apex phase. The largest gradients of the wave parameter sequence change occurred in the rising phase, and this was the main factor generating efficient beachface erosion. It induced an increase in sandbar size, accompanied by the cross-shore motion of maximum velocity amplitude, more violent disturbances of wave nonlinearity, and increased surf zone erosion, with these factors increasing beach instability and leading to more severe storm erosion. The large wave height and water level resulted in shoreline retreat, with a more significant swash zone erosion under a higher runup. The offshore sediment transport turned toward the onshore direction as the original large sandbar deteriorated under the decreasing wave parameter sequence in the waning phase. [ABSTRACT FROM AUTHOR]

Estuarine sediment transport is driven by the combined action of a multitude of influencing factors, including astronomical tides, waves dynamics, and river discharges. This study focuses on the effects of wave forces on sediment transport patterns in micro-tidal estuaries near Wanbao Beach, China. Numerical simulations are carried out using Delft3D. Modeling scenarios are configured using different wave characteristics, spanning from typical waves to those with a return period of 50 years. Results show that waves have a positive effect on landward sediment transport, resulting a larger active range of sediment. By comparing the spatial geomorphic variations under varying wave conditions, we find that modifications in significant wave height (Hs) primarily impact the position of erosion and deposition zones, whereas alterations in spectral peak period (Tp) predominantly influence the magnitude of these changes. The finding is further demonstrated by a comparison of residual currents under different wave intensities. Analysis of sediment transport rates in different transects indicates that the sediment transport rate is highest at the mouth transects and lowest at the alongshore transects. Moreover, variations in sediment transport rates exhibit distinctive patterns between the two outlet transects, even when subjected to identical wave conditions. The disparities are attributed to differences in runoff and the topographical features in proximity to the estuaries. Additionally, we find the sediment transport rate becomes insensitive to the variations in Hs when Hs is larger than a threshold value. The threshold decreases with increasing Tp. [ABSTRACT FROM AUTHOR]

This study aims to obtain safe working condition of the electrothermal U-shaped actuator (EUA). The finite difference method is applied for modeling and solving the steady electric-thermal state and maximum temperature of the microactuator. The critical voltages causing beam buckling and overheating phenomena are determined to avoid the axial instability as well as melting deformation of the actuator. The relationships between temperature and the frequency or amplitude of the AC are analyzed. The results showed that the structure and the applied voltage levels have significant influence on the temperature distributions and the value of the stress. It is confirmed that the temperature between 300 to 600 °C is comparatively suitable for microactuator according to theoretical and experimental analysis, and the microactuator is able to provide accurate and stable number of cycles for tens of millions. [ABSTRACT FROM AUTHOR]

We study the sum of the finite multiple harmonic q-series on r-(r + 1) indices at roots of unity with r = 1, 2, 3. Mainly, we give equivalent conditions of two conjectures regarding cyclic sums of finite multiple harmonic q-series on 1-2-3 indices at roots of unity, posed recently by Kh. Pilehrood, T. Pilehrood and R. Tauraso. [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]

Copper is the only metal that can convert CO2 into C2 and C2+ in electrocatalytic carbon dioxide reduction (CO2RR). However, the Faraday efficiency of CO2 conversion to C2 and C2+ products at high current densities is still low, which cannot meet the actual industrial demand. Here, the design methods of single‐atom copper catalysts (including regulating the coordination environment of single‐atom copper, modifying the carbon base surface and constructing diatomic Cu catalysts) are reviewed, and the current limitations and future research directions of copper‐based single‐atom catalysts are proposed, providing directions for the industrial conversion of CO2 into C2 and C2+ products. [ABSTRACT FROM AUTHOR]

Simple Summary: Largemouth bass (Micropterus salmoides) has been widely cultured in China, and ammonia stress has become one of the important reasons limiting the development of largemouth bass' farming. However, the response of largemouth bass to ammonia stress is still to be investigated. In addition, N-carbamylglutamate has been considered as a potential anti-stress additive in terrestrial animals. Currently, it remains to be explored whether N-carbamylglutamate can enhance fish resistance under environmental stress. Our findings in this study could enrich our understanding of the responses in largemouth bass under ammonia stress and help us solve the existing problem of environmental stress in largemouth bass culture. Ammonia is a common environmental limiting factor in aquaculture. To investigate the effects of ammonia stress and explore the protective effect of N-carbamylglutamate (NCG) on Micropterus salmoides (M. salmoides), tissue sections and parameters related to oxidative stress and the inflammatory response in M. salmoides were carried out during the ammonia stress test and feeding test. The results demonstrated that the LC50 for 24 h, 48 h, 72 h, and 96 h under ammonia stress in M. salmoides were 25.78 mg/L, 24.40 mg/L, 21.90 mg/L, and 19.61 mg/L, respectively. Under ammonia stress, the structures of the tissues were damaged, and the GSH content decreased, while the MDA content increased with the increase in stress time and ammonia concentration. The NO content fluctuated significantly after the ammonia nitrogen stress. In the 15-day feeding test, with the increased NCG addition amount and feeding time, the GSH content increased while the MDA and NO contents decreased gradually in the NCG addition groups (NL group: 150 mg/kg; NM group: 450 mg/kg; NH group: 750 mg/kg) when compared with their control group (CK group: 0 mg/kg). In the ammonia toxicology test after feeding, the damage to each tissue was alleviated in the NL, NM, and NH groups, and the contents of GSH, MDA, and NO in most tissues of the NH group were significantly different from those in the CK group. The results suggested that ammonia stress caused tissue damage in M. salmoides, provoking oxidative stress and inflammatory response. The addition of NCG to the feed enhances the anti-ammonia ability of M. salmoides. Moreover, the gill and liver might be the target organs of ammonia toxicity, and the brain and kidney might be the primary sites where NCG exerts its effects. Our findings could help us to find feasible ways to solve the existing problem of environmental stress in M. salmoides culture. [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]

Scour at coastal structures is a serious problem that causes damage to structures. Focusing on scour around typical gravity-type breakwaters, previous studies have revealed that scour is mainly caused by standing waves in the front of structures. For breakwaters, which consist of closely spaced circular piles, scour caused by flow may occupy a dominant position. In the present work, the scour caused by a small velocity intensity flow was studied using both experimental and numerical models. The experiments revealed that the scour depth around closely spaced circular piles was significantly larger than that of a single pile with the same diameter. The numerical model was verified by theoretical values of flow field and experimental values of scour topography. More detailed flow field information is described using a numerical model that can improve the understanding of scour mechanics. Both experimental and numerical models demonstrate that scour first occurs on the side of piles owing to the shrinkage effect of streamlining and then extends forward and backward. In addition, the scour mechanics change with the increase of the pile spacing. [ABSTRACT FROM AUTHOR]

Ocean surface waves exposed to extreme weather conditions, such as tropical cyclones (TCs), are critical environmental forces acting on the coastal and offshore structures. Therefore, it is necessary to investigate the applicability of the third-generation wave model WAVEWATCH III for simulated waves in the China Seas, where TCs are frequent. This study compares different packages of wind input and wave dissipation (ST1, ST2, ST3, ST4, and ST6) during five TCs with significant wave heights (SWHs) and wave spectra in the Yellow Sea, East China Sea, and South China Sea. The results show that ST6 performs best in the simulation of the SWHs, presenting the only positive deviation, with a normalized mean bias of 1.76%. ST2 systematically underestimates the large SWHs due to insufficient wind input from the spectra. However, the suitability of the packages varies in different sea conditions. ST6 is preferred in extreme wave simulations during TCs, ST4 performs best under the weak influence of TCs, and ST2 has the best performance in calm sea conditions. [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]

For the global performance of monopile wind farms, the desired wave field distribution using traditional layout methods is hard to obtain. In this study, the investigation aims to efficiently explore the potential wave response reduction of the multiple layer design of wind farm layouts using novel grating conditions. It is very important and necessary to optimize the layouts of monopile-supported OWTs (offshore wind turbines) by analyzing the wave field performance, especially considering scour protection and avoiding the proximity of the wave frequency to natural frequency of OWTs. This paper presents a layout and a design method of monopile-supported OWTs using combined grating theorems, which can take space modulation into account to deal with various issues in existing layouts. The results show that the present method can modulate the wave field responses more evenly than the conventional cases. More specifically, total wave field distribution sensitivities were discussed under different wavelengths, amplitudes, layouts, pile-radius, and the angles of incident waves. It can be illustrated that the monopile-supported OTWs with sinusoidal configurations can have more modulation effects on wave fields in an appropriate wavelength band. As indicated, this method not only provides wave space modulation control but also sheds light on the wave field reduction mechanisms. [ABSTRACT FROM AUTHOR]

Local scour around submerged square piles is very common in offshore and coastal engineering and can result in pile failure. In the study reported here, because the flow intensity (the ratio of the depth-averaged velocity to the threshold velocity for sediment particle motion) is one of the most important factors affecting the maximum scour depth in local scour, its effects on local scour around a submerged square pile were studied under clear-water scour conditions. A series of experimental tests with flow intensity in the range of 0.39–1.04 was conducted in steady current, and the flow intensity was classified as weak, transitional, or high according to the pattern of the scour hole upstream of the pile and the sand dunes downstream. The characteristics of sediment scour and deposition for temporal sediment bed elevation along a pile side and the temporal maximum scour depth were found to vary greatly among the three flow intensity conditions. An exponential function, which fitted the experimental data well, was used to fit how the maximum scour depth evolved, and the coefficients of timescale and scour depth proportion in the initial and development scouring stages were obtained at different values of the flow intensity. [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]

Electrochemical carbon dioxide reduction reaction (CO2RR) is an efficient strategy to relieve global environmental and energy issues by converting excess CO2 from the atmosphere to value‐added products. Atomically dispersed metal‐nitrogen‐doped carbon (M‐N‐C) materials are superior catalysts for electrocatalytic CO2RR because of the 100% atomic utilization, unsaturated coordination configuration, relatively uniform active sites, and well‐defined and adjustable structure of active centers. However, the electrochemical CO2RR is a great challenge due to the process involving proton‐coupled multi‐electron transfer with a high energy barrier, which leads to unsatisfactory selectivity to the targeted product, especially for C2 products (e.g., C2H4 and C2H5OH). Here, the authors systematically summarize effective means, including reasonable selection of isolated metal sites, regulation of the coordination environment of isolated metal atoms, and fabrication of dimetallic single‐atom sites for attaining optimal geometric and electronic structures of M‐N‐C materials and further correlate these structures with catalytic selectivity to various C1 (e.g., CO and CH4) and C2 products in the CO2RR. Moreover, constructive strategies to further optimize M‐N‐C materials for electrocatalytic CO2RR are provided. Finally, the challenges and future research directions of the application of M‐N‐C materials for electrocatalytic CO2RR are proposed. [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]

To solve the energy crisis and environmental pollution problems, the use of clean and renewable energy to replace fossil energy has become a top priority. The oxygen evolution reaction (OER) is the core of many renewable energy technologies. Developing low-cost and high-performance OER electrocatalysts is the key to implementing efficient energy conversion processes. Here, we synthesize ordered mesoporous iron–cobalt oxides using a hard template strategy. As a mesoporous oxide catalyst, meso-CoFe0.05Ox exhibits low OER overpotentials of 280 and 373 mV at current densities of 10 and 100 mA cm−2, respectively, and does not show deactivation for at least 18 hours at 100 mA cm−2. The introduction of iron can change the electronic structure of Co, and the orbital electrons are easily transferred from cobalt to iron. The enhanced OER performance can be attributed to concerted catalysis between the iron and cobalt sites that lowers the OER energy barrier, and the large specific surface area of the porous oxide providing efficient active sites for the reaction. [ABSTRACT FROM AUTHOR]

In this paper, a bi-directional friction linear micro-motor (BFLM) driven by a set of micro-actuators was introduced and analyzed. The BFLM was fabricated using PolyMUMPs process. The impact dynamics model for the BFLM was established, and its motion equation was also derived that takes into account the friction and contact. The relative motion between the driving head and the slider, as well as forward or backward movement of the slider were analyzed in detail. The forward and backward movement displacement of the slider was measured, and the experimental results were in good agreement with theoretical predictions. The theoretical results show that the motion direction of the slider can be changed by controllable driving frequency to the BFLM. It was feasible to use a set of actuators to drive the slider in bi-directional motion. [ABSTRACT FROM AUTHOR]

Lipopolysaccharide (LPS), known as endotoxin, is the cell wall component of Gram‐negative bacteria. In this study, the haemolymph enzyme activities, the morphology of hepatopancreas, the immunological responses of hepatopancreas and haemocytes in Litopenaeus vannamei (L. vannamei) were studied to investigate the physiological responses after LPS injection. Histological results indicated that necrotic hepatic tubules occurred after injection of LPS for 12 hours (h), and then, the increasing number of the necrotic hepatic tubules and inflammatory cell infiltration was observed. Furthermore, the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) decreased before 12 h and then increased to the peak at 48 h. However, ALP activity increased significantly. Anti‐lipopolysaccharide factors (ALFs) of crustacean play an important role against bacterial infection. Specifically, it was worth mentioning that the expression of ALFC in the hepatopancreas and haemocytes increased significantly at 6 h and the expression of ALFB increased significantly at 24 h in haemocytes. Moreover, the expression of unfolded protein response (UPR) related genes decreased at 3 h and then increased in the hepatopancreas and haemocytes and the expression of glucose‐regulated protein 78 kDa (GRP78), inositol‐requiring enzyme‐1 (IRE1) and protein kinase RNA‐like endoplasmic reticulum kinase (PERK) in haemocytes increased significantly at 48 h. These results revealed that LPS injection damaged hepatopancreas structure of L. vannamei, increased haemolymph enzyme activities and activated the UPR pathway and ALF‐related genes. [ABSTRACT FROM AUTHOR]

Global cerebral ischemia induced by cardiac arrest usually leads to poor neurological outcomes. Numerous studies have focused on ways to prevent ischemic damage in the brain, however clinical therapies are still limited. Our previous studies revealed that delta opioid receptor (DOR) activation with [d-Ala2, d-Leu5] enkephalin (DADLE), a DOR agonist, not only significantly promotes neuronal survival on day 3, but also improves spatial memory deficits on days 5-9 after ischemia. However, the neurological mechanism underlying DADLE-induced cognitive recovery remains unclear. This study first examined the changes in neuronal survival in the CA1 region at the advanced time point (day 7) after ischemia/reperfusion (I/R) injury and found a significant amelioration of damaged CA1 neurons in the rats treated with DADLE (2.5 nmol) when administered at the onset of reperfusion. The structure and function of CA1 neurons on days 3 and 7 post-ischemia showed significant improvements in both the density of the injured dendritic spines and the basic transmission of the impaired CA3-CA1 synapses following DADLE treatment. The molecular changes involved in DADLE-mediated synaptic modulation on days 3 and 7 post-ischemia implied the time-related differential regulation of PKCα-MARCKS on the dendritic spine structure and of BDNF- ERK1/2-synapsin I on synaptic function, in response to ischemic/reperfusion injury as well as to DADLE treatment. Importantly, all the beneficial effects of DADLE on ischemia-induced cellular, synaptic, and molecular deficits were eliminated by the DOR inhibitor naltrindole (2.5 nmol). Taken together, this study suggested that DOR activation-induced protective signaling pathways of PKCα-MARCKS involved in the synaptic morphology and BDNF-ERK-synapsin I in synaptic transmission may be engaged in the cognitive recovery in rats suffering from advanced cerebral ischemia. [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]

White type Channa argus, which has the common name of the great northern snakehead, has an uncertain classification for many years. In the present study, mitochondrial COI gene has been used to analyze the relationships and genetic diversity of nine kinds of Channa. For the Chnannidae family, the average of the inter-species genetic distance was 0.156 (ranged: 0.000–0.245). And the intra-species genetic distances were ranged from 0.000 to 0.002. For the haplotypes of two-colour morphs of Channa argus, the mean of the pair-wise genetic distances was estimated as 0.0009. This value was within the intra-species genetic distance interval, indicating that two-colour morphs of Channa argus are not subspecies of white type at the molecular level. Moreover, take Lateolabrax maculates and Epinephelus coioides as outgroups, molecular phylogenetic tree showed that all the haploids gather together as a branch and crossing each other. These indicated that the white type Channa argus should be regarded as an albino of bio colour type. [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]

Koumine is a component of the Chinese medicinal herb Gelsemium elegans and is toxic to vertebrates. We used the ciliate Tetrahymena thermophila as a model to evaluate the toxic effects of this indole alkaloid in eukaryotic microorganisms. Koumine inhibited T. thermophila growth and viability in a dose-dependent manner. Moreover, this drug produced oxidative stress in T. thermophila cells and expressions of antioxidant enzymes were significantly elevated at high koumine levels (p < 0.05). Koumine also caused significant levels of apoptosis (p < 0.05) and induced DNA damage in a dose-dependent manner. Mitophagic vacuoles were present in cells indicating induction of autophagy by this drug. Expression of ATG7, MTT2/4, CYP1 and HSP70 as well as the MAP kinase pathway gene MPK1 and MPK3 were significantly altered after exposed to koumine. This study represents a preliminary toxicological evaluation of koumine in the single celled eukaryote T. thermophila. [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]

Electrothermal microactuators have a very promising future in MEMS applications since they can generate large displacement and force with low actuating voltages and small device areas. In this paper, a temperature distribution and unload displacement model of a V-shaped electrothermal microactuator are presented. In order to prove the accuracy of the model, finite element analysis (FEA) and experimental results are provided for comparison. The results of temperature profile and unload displacement output, which are from the model calculation, FEA and experimental test, agree well with each other. It gives an indirect proof that the model is correct and FEA calculation is practicable. It can be shown that the shape of the actuator has no effect on the maximum temperature, and the unload displacement and output force depend on the beam length and inclined angle of the actuator. [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]

The article discusses the differentiation of gonadal sex between hybrid snakehead of channa argus and channa maculate. According to the author the differentiation is conducted on the basis of genetic and environmental factors and sex control patterns. Also reflects on testicular differentiation and putative testis.

As an unclassified species, white-type Channa argus has existed for many years. In the present study, the relationships and genetic diversity in two colour morphs of northern snakehead were determined by the analysis of mitochondrial 12S rRNA gene, as well as other Channa species. The results of sequence analysis showed that the average genetic distance was 0.046 with the interspecies genetic distance ranging from 0.000 to 0.130; and the average interspecies genetic distance was estimated as 0.003 (range: 0.000-0.006). For the two colour morphs of Channa argus, the mean pair-wise genetic distance between them was also estimated as 0.003. Moreover, molecular phylogenetic tree was constructed using MEGA6.0, which showed that all the haploids gathered together as a branch and crossed each other. These results indicated that the white and biocolour-type Channa argus belonged to the same species, rather than subspecies at the molecular level, and the white-type Channa argus should be regard as an albino of biocolour type. [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]

Wang, Z.; Yin, Z.; Chen, Y., and Yang, B., 2017. Numerical study on the effects of submerged breakwater on wave overtopping. In: Lee, J.L.; Griffiths, T.; Lotan, A.; Suh, K.-S., and Lee, J. (eds.), The 2nd International Water Safety Symposium. Journal of Coastal Research, Special Issue No. 79, pp. 264-248. Coconut Creek (Florida), ISSN 0749-0208. In order to protect beach or mud coastlines, submerged breakwaters are built in the world widely. When the submerged breakwater is designed, one important issue having to be analyzed is wave overtopping of coastlines or coastal preventing structures since the wave overtopping is very dangerous for people or structures on the potential coastal zones with probability of wave overtopping appearing. A 2-D numerical wave flume has been established based on Flow-3D software to investigate effects of incident wave parameters in front of the submerged breakwaters, slope of the beach and the submerged breakwaters themselves, respectively. The numerical wave flume has been verified by the theoretical data of wave equation and wave frequency spectrum of physical experiment. The computational results fitted well with the theoretical data. The calculated values of the overtopping are in good agreement with the physical model test values under the conditions of random wave. The verified model has been used to calculate the wave overtopping under the different wave height, wave period and slope of the beach. The results of numerical model test indicate that the wave overtopping without a submerged breakwater is much more than that with one for random wave approaching, which is similar as phenomena found in physical experiments. The relationship between wave overtopping and wave height, wave period, slope of the beach was discussed. And a new empirical formula to calculate the overtopping was fitted based on the method of dimensional analysis. [ABSTRACT FROM AUTHOR]

A spherical particle’s acceleration fall through still fluid was investigated analytically and experimentally using the Basset-Boussinesq-Oseen equation. The relationship between drag coefficient and Reynolds number was studied, and various parameters in the drag coefficient equation were obtained with respect to the small, medium, and large Reynolds number zones. Next, some equations were used to derive the finite fall time and distance equations in terms of certain assumptions. A simple experiment was conducted to measure the fall time and distance for a spherical particle falling through still water. Sets of experimental data were used to validate the relationship between fall velocity, time, and distance. Finally, the initial velocity effect on the total fall time and distance was discussed with different terminal Reynolds numbers, and it was determined that the initial velocity plays a more important role in the falling motion for small terminal Reynolds numbers than for large terminal Reynolds number scenarios. [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]