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Investigating the electric power generated by wave energy converters (WECs) has attracted increasing attention along with the developments of wave energy converting technologies in recent years. Electric power estimation currently depends on wave-to-wire model-based numerical analysis and experimental studies of scale-down prototypes. However, traditional numerical simulations are time-consuming and expensive for power orediction of a full-scale WECs operated in real sea. More importantly, they cannot accurately predict WECs' power performance in real time, thereby cannot be used for prediction-based real-time control. To address those problems, four machine learning techniques are employed as an alternative to traditional, complex physical modelling processes to evaluate and predict the generated electric power, based on historical experimental data of a two-body hinge-barge WEC. Comparative results of a Backpropagation (BP) Neural Network algorithm, a Long Short-Term Memory (LSTM) algorithm, a Support Vector Machine (SVM) algorithm and a Radial Basis Neural Network (RBFF) algorithm indicate that machine-learning-based approaches can accurately predict the electric performance of this complex multi-degree-of-freedom WEC, where the coefficient of determination (R 2) of the BP Neural Network on the test dataset is up to 0.9987. • Four machine learning techniques are employed to evaluate and predict the electric power. • The machine learning techniques can be used to predict WECs' power performance under new sea state. • The coefficient of determination (R2) of the BP Neural Network is up to 0.9987. [ABSTRACT FROM AUTHOR]

Wave energy is a practical option for the sustainable powering of the drifting buoy beyond solar energy. However, efficient harvesting of wave energy from a complex and dynamic ocean environment for a drifting buoy is significantly challenging, since the buoy's global location and orientation are always in spatiotemporal variation. Herein, we propose a novel multi-DOF wave energy harvesting mechanism that integrates three sets of frequency-tunable harvesting systems into an enclosed drifting buoy, which can greatly enhance the energy harvesting ability of a long-term working drifting buoy that encounters direction-varying and frequency-varying waves. A time-averaged electric power up to 9.18 mW was achieved by a prototype that has a diameter of 45 cm, which is 32.76 % higher than the single-DOF case in sea trials. Additionally, laboratory dry test results show that the prototype provided a power up to 288.76 mW in one direction. This work provides an effective strategy for sustainably generating electricity in the offshore environment for drifting buoys. • A built-in multi-DOF wave energy harvester for a drifting buoy was presented. • Two different-sized prototypes were designed, assembled and tested in the open sea. • A time-averaged electric power of up to 9.18 mW was achieved in real sea tests. • The prototype generated a power of up to 288.76 mW in one direction in laboratory dry test. [ABSTRACT FROM AUTHOR]

The rise in carbon emissions linked to the tourism industry has challenged its long-standing reputation as an eco-friendly sector. In parallel, the digital economy's evolution has introduced a series of transformations within tourism. This necessitates a thorough examination of the intricate interplay between the digital economy and carbon emissions in the tourism sector. With the help of Chinese provincial panel data, this study uncovers a compelling relationship marked by an inverted "U" curve through two-way fixed model, moderated effects model and threshold regression analysis. Intriguingly, an increase in road density shifts the inflection point of this curve to the lower left. As road density reaches a critical threshold of 0.361, it not only amplifies the elasticity of the inverted "U" curve but also accelerates the timeline to reach peak tourism-related carbon emissions. This study underscores a significant practical implication: while digital technology exacerbates carbon emissions from tourism at this stage, the dampening effect of digital technology is to be expected as the development of industrial manufacturing brings better transportation. However, the timing of the tipping point may be earlier or later for different regions, depending on whether the local level of industry is sufficiently developed. • The inverted "U" curve relationship between digital economy growth and tourism carbon emissions at the provincial level in China is validated. • Transportation accessibility is a key mechanism by which the digital economy affects carbon emissions from tourism. • This paper predicts the conditions for an inflection point in tourism carbon emissions within digital economy. [ABSTRACT FROM AUTHOR]

• Cryogenic throttle valves for superfluid helium system were developed and numerically simulated. • Influences of cone angle, unilateral minimum clearance, structure type and working medium type on flow field distribution and flow characteristics of valve are studied. • Increasing the cone angle and unilateral minimum clearance enhances valve flow capacity, with the cone angle having a more pronounced impact. • Altering the spool type significantly alters the flow characteristics, whereas changing the working fluid type only affects the velocity and pressure within the valve. As one of the important methods to obtain superfluid helium, throttling has been widely used due to its simple equipment. The cryogenic throttle valve, serving as a vital component in the throttling process, directly impacts the performance of the superfluid helium system. In this study, velocity and pressure field inside valve is numerically simulated by using computational fluid dynamics (CFD), and the flow characteristics of the valve are analyzed by theoretical calculations and experiments. Moreover, influences of cone angle, unilateral minimum clearance, structure type and working medium type on flow field distribution and flow characteristics of valve are studied by altering structural parameters of spool and working medium. The results demonstrate that increasing cone angle and unilateral minimum clearance can enhance flow capacity of valves, but influence of cone angle is more obvious. Changing the spool type will significantly alter the flow characteristics of the valve, while changing the working fluid type will only affect the velocity and pressure inside the valve. [ABSTRACT FROM AUTHOR]

Hard nitride coatings have the prospect of acting as protective layers for cutting tools because of their excellent mechanical properties and wear resistance. To enhance the mechanical, tribological, and high-temperature oxidation properties, the structural design of the coating is important. In this study, TiSiN, CrAlN/TiSiN bilayer and CrAlN/TiSiN multilayer coatings were deposited on the surface of high-speed steel by multi-arc ion plating technology. The microstructure, phase composition, mechanical properties and high-temperature tribological properties of prepared coatings were analyzed. Results indicated that the TiSiN and CrAlN/TiSiN bilayer coatings contain TiN phases and the CrAlN/TiSiN multilayer coating contains three main phases of TiN, AlN and CrN. The CrAlN/TiSiN multilayer coating possesses a denser microstructure than the other two coatings. The multilayer structure improves the cohesive and bonding strength of the coating by reducing the shear stress. The CrAlN/TiSiN multilayer coating exhibits a stable coefficient of friction and excellent wear resistance during high-temperature friction. The formation of TiO2 and Al2O3 oxide layers on the surface of the coating in a high-temperature environment contributes to the desired tribological properties of the coatings. [ABSTRACT FROM AUTHOR]

This paper presents a systematic methodology to optimise the geometry of a three-body hinge-barge wave energy converter, to maximise the energy extraction of the device in given sea states and in site-specific wave climates. To that end, a 5-degree-of-freedom mathematical model is proposed to describe the system dynamics in two-dimensional space and a two-layer optimisation is designed to find the optimal design and control variables. The inner-layer optimisation is used to find the optimal control parameters of the power take-off system and the outer-layer optimisation, which uses a genetic algorithm, is employed to find the optimal design parameters of barge lengths and of optimal ballast positioning. In the case study, this methodology is applied to a 1:20 scale prototype of the McCabe Wave Pump device. Numerical results indicate that the optimal dimensions of the device, under given sea states, can be found efficiently and accurately, and that there appears to be no obvious benefit in the use of three barges, over a two-barge system. • Geometric optimisation of a 3-barge hinge barge device (no comparable work to date). •Combined optimisation of geometry AND optimal positions for ballast masses. •2-level optimisation, updating the control for each geometry/ballast specification. •The analysis points to an optimal 2-barge configuration. [ABSTRACT FROM AUTHOR]

The co-production of ethylene glycol and methanol via ethylene carbonate hydrogenation derived from CO 2 has attracted great concerns because of the promising chemical utilization of CO 2 in large-scale. Copper-based catalysts are widely concerned in hydrogenation of ester due to the high catalytic efficiency and low cost, but the stability of copper-based catalyst is poor and needs to be further improved. In this study, the modification Cu–C@SiO 2 -R catalyst with graphite oxide was prepared by using Cu 3 (BTC) 2 as the precursor and ammonia evaporation method, and was applied in ethylene carbonate hydrogenation to synthesis ethylene glycol and methanol. Furthermore, the catalysts were characterized in detail. The results showed that the Cu–C@SiO 2 -R catalyst was modified with graphite oxide, the average size of Cu particles was 2.9 nm and Cu particles had good dispersion. In addition, both Cu–C@SiO 2 -R and Cu@SiO 2 -R catalysts had similar ratio of Cu+/(Cu0+Cu+). In a batch reactor, under 453 K, 5 MPa, 4 h, the catalytic efficiency was 80.0% EC conversion 92.2% EG and 70.8% MeOH selectivity showing excellent catalytic performance capability of Cu–C@SiO 2 -R catalyst. In long-term experiment, the Cu–C@SiO 2 -R catalyst showed excellent stability after using for 264 h. The activity was 0.63 g EC g cat −1 h−1, and 100.0% EC conversion 99.9% EG and 85.8% MeOH selectivity could be achieved in a fixed bed. After the long-term experiment, the Cu+/(Cu++Cu0) ratio in Cu–C@SiO 2 -R catalyst kept at around 0.48. In contrast, the Cu+/(Cu++Cu0) ratio in Cu@SiO 2 -R catalyst decreased sharply from 0.48 to 0.38. The stability of the structure and the balance of valence of Cu were considered to be responsible to the stability of Cu–C@SiO 2 -R catalyst, because the graphite oxide not only kept the Cu+/(Cu0+Cu+) ratio stability, but also restrained the aggregation of Cu particles and loss of copper. This work provides an in-depth understanding of the stabilization mechanism of Cu and can be a reference for the industrial application of ethylene carbonate hydrogenation. Graphite oxide modified Cu–C@SiO 2 -R catalyst was successfully prepared by using Cu 3 (BTC) 2 as the precursor and ammonia evaporation method, exhibited a high activity and stability for the hydrogenation of ethylene carbonate to co-produce methanol and ethylene glycol. [Display omitted] •The modification Cu–C@SiO 2 catalyst by graphite oxide was successfully prepared. •The Cu–C@SiO 2 catalyst shows superior catalytic performance. •Long-term experiment shows the Cu–C@SiO 2 catalyst has excellent catalytic stability. •The modification of graphite oxide is beneficial to keep the balance of copper species in the catalyst. [ABSTRACT FROM AUTHOR]

With the growing worldwide attention to marine environment protection, marine resource exploration, and so on, unmanned surface vehicles (USVs) have become one of the critical mobile marine observation equipment. However, USVs generally rely on limited onboard batteries to provide electricity, and thus, they have low endurance and poor load capacity. The lack of a long-term power supply is currently a great challenge for the further application and development of USVs. Harvesting energy from the working environment of USVs is a promising solution to address that problem. To demonstrate the possibility of this scheme, a physical prototype of a novel USV with a built-in vibration energy harvester has been fabricated and tested in an open sea for the first time. Moreover, a full-coupled mathematical model is developed to further optimize the power performance of the USV based on the Taguchi method. Experimental results show that this prototype can generate a maximum instantaneous electric power of 277.71 mW , 112.95 mW and 101.27 mW when the USV is in a status of towage, propulsive and free-floating, respectively. Simulation results present that the optimized USV can achieve a mean electric power of 246.14 mW , which is improved by 49. 88 % compared with the unoptimized results of the developed prototype. • A novel USV with a built-in vibration energy harvester is developed. • A physical prototype is designed, fabricated and tested in an open sea. • A maximum instantaneous electric power of 277.71 mW is achieved in open sea tests. • The vibration energy harvester is numerically optimized based on the Taguchi method. [ABSTRACT FROM AUTHOR]

With the growing worldwide attention to marine environment protection, marine resource exploration, and so on, unmanned surface vehicles (USVs) have become one of the critical mobile marine observation equipment. However, USVs generally rely on limited onboard batteries to provide electricity, and thus, they have low endurance and poor load capacity. The lack of a long-term power supply is currently a great challenge for the further application and development of USVs. Harvesting energy from the working environment of USVs is a promising solution to address that problem. To demonstrate the possibility of this scheme, a physical prototype of a novel USV with a built-in vibration energy harvester has been fabricated and tested in an open sea for the first time. Moreover, a full-coupled mathematical model is developed to further optimize the power performance of the USV based on the Taguchi method. Experimental results show that this prototype can generate a maximum instantaneous electric power of 277.71 mW , 112.95 mW and 101.27 mW when the USV is in a status of towage, propulsive and free-floating, respectively. Simulation results present that the optimized USV can achieve a mean electric power of 246.14 mW , which is improved by 49. 88 % compared with the unoptimized results of the developed prototype. • A novel USV with a built-in vibration energy harvester is developed. • A physical prototype is designed, fabricated and tested in an open sea. • A maximum instantaneous electric power of 277.71 mW is achieved in open sea tests. • The vibration energy harvester is numerically optimized based on the Taguchi method. [ABSTRACT FROM AUTHOR]

Unmanned surface vehicles (USVs) are playing a significant role in the marine science and engineering field, e.g., they have been widely used in measuring ocean waves and currents. However, their operation time and range are limited by the energy carried by internal batteries, and this challenge needs to be urgently addressed. In this study, a novel USV concept that can harvest vibration energy excited by ocean waves in the heaving and pitching direction is presented, which provides a sustainable and continuous power supply. A fully coupled wave-to-wire model that considers the viscous damping force is developed to investigate the dynamics and electric power performance of this novel device under site-specific realistic wave climates, with the external electric load optimally tuned for each sea state. Besides, the influence of the forward speed, geometric size, mass ratio and end-stop spring is studied. Numerical results show that the proposed USV in a freely floating situation can efficiently capture and convert harvested energy into electricity with a wave-to-wire efficiency of up to 20. 21 %. Additionally, it can generate an annual mean electric power of 29.73 W, under the wave climates of the national wave energy test site in China. • A novel wave-powered unmanned surface vehicle is designed. • A fully coupled wave-to-wire model is developed. • A high wave-to-wire efficiency up to 20.21% is obtained. • An annual mean electric power of 29.73 W is achieved by the USV. [ABSTRACT FROM AUTHOR]

Unmanned surface vehicles (USVs) have been widely used in various fields credited for their high flexibility and excellent manoeuvrability. However, the limited onboard electricity of USVs restricts their applications in long-term working tasks. A promising option to address that problem is employing a wave-powered USV, where a wave energy converter is integrated into the USV. For a wave-powered USV, it is challenging to achieve a precise estimation of its power generation under complex marine environments. Although there are physics-based models of WECs used for the estimation and prediction of power generation of USVs, they cannot achieve satisfactory accuracy in practice because of the linearization and simplification of those mathematical modelling. To fill up this gap, this paper proposes a data-driven modelling method utilizing feature engineering and ensemble learning to estimate the mean power generation of a wave-powered USV, relying on time-serial measurements obtained from real physical wave-flume experiments under regular waves. Results show that the estimation achieves promising performance, where the minimum RMSEs are 3.359 mW and 6.148 mW for a harvester-to-wire model and a wave-to-wire model, respectively. Additionally, the proposed method shows great potential for real-sea applications, such as online power prediction and control. • A data-driven method for power estimation of a wave-powered USV is proposed. • The robustness of the proposed method is verified with the presence of noise. • The proposed method possesses practical significance, such as data-driven control. [ABSTRACT FROM AUTHOR]

With the diversification of marine monitoring buoy functions, limited onboard batteries have been unable to meet the energy demand of multifarious carrying sensors. Finding a self-sustained power supply for marine monitoring buoys is an urgent problem, while wave energy is an ideal and promising option to address that problem. In this study, two wave-excited vibration energy harvesters (WVEHs) are proposed, which can be installed inside large buoys to provide a sustainable power supply. A full-coupled wave-to-wire model is developed to investigate the influence of blocks' mass, geometric size of buoys, mooring system and WVEH's quantity on the electric power performance of harvesters in realistic sea states. Parametric studies based on the Taguchi method imply that the sea state and the WVEH's quantity have a significant effect on the device's electric power performance. Numerical results indicate that the optimized two harvesters can produce a mean electric power of 777.50 W and 747.43 W , respectively, under a sea state with a peak wave period of 7 s and a significant wave height of 1.6 m. A high wave-to-wire efficiency of 2. 60 % is obtained for a specific system parameter combination. Furthermore, more electric power generation can be achieved by installing multiple harvesting units. • Two wave-excited vibration energy harvesters are proposed for large marine buoys. • A full-coupled wave-to-wire model is developed. • Harvesters are optimized based on the Taguchi method in realistic sea states. • A mean electric power of 777.50 W is achieved under a peak wave period of 7 s. [ABSTRACT FROM AUTHOR]

• The bio-based carbamate was directly synthesized from CO 2 and pentanediamine (PDA). • The performance of the CeO 2 catalyst was influenced by doping a small amount of Zr. • The diethyl carbonate intermediate is generated from the reaction of CO 2 and ethanol, and subsequently transformed into PDC. • The Zr 0.05 Ce catalyst showed good catalytic activity in the carbonylation between PDA and CO 2. Diethyl pentane-1,5-diyldicarbamate (PDC), a bio-based intermediate used for isocyanate and polyurethanes, was synthesized by the direct carbonylation of CO 2 and pentanediamine (PDA) with 2-cyanopyridine (2-CP) over Zr-doped CeO 2. In this study, Zr-doped CeO 2 catalysts with different contents of Zr are successfully synthesized to produce PDC from PDA, CO 2 , and ethanol. Among them, Zr 0.05 Ce exhibits enhanced reaction activity and the productivity reached 6.0 mmol·g−1·h−1. Characterizations based on X-ray photoelectron spectroscopy, Raman, and CO 2 /NH 3 -temperature-programmed desorption prove that the doping of Zr atoms into CeO 2 regulates the acid–base sites and promotes oxygen vacancy formation, which is primarily responsible for the formation of monoethyl carbonate, an intermediate for diethyl carbonate (DEC). In-situ diffuse reflectance Fourier-transform spectrometry and Fourier-transform infrared spectroscopy reveal that PDA reacts with 2-CP to form N, N'-(pentane-1,5-diyl)dipicolinamide, which are transformed into PDC. Finally, the catalytic activity could be regenerated after calcination. This study presents a green route for producing bio-based carbamate by constructing C-N bond using CO 2 as a carbonyl source, which can replace carbamates derived from petrochemical resources in the future. [Display omitted] [ABSTRACT FROM AUTHOR]

Biogas slurry has ammonia (NH 4 +-N) abundance and is applied in a major production region, Southwest China. This study compared the consequent environmental risk of nitrogen (N) leaching in two major soils, yellow soil and calcareous soil, in Southwest China, and investigated underlying microbial mechanisms. Biogas slurry was applied to soil columns packed with yellow soil and calcareous soil at the rates of 0 to 240 kg N/hm2. Soil N leaching, N contents, and N-related bacteria gene abundances were measured, with their responses to slurry application analyzed through partial least squares-structural equation modeling (PLS-SEM). Nitrate (NO 3 −-N) dominated in N leaching as a result of soil NO 3 −-N accumulation and microbial regulation. Nitrification increased yellow soil NO 3 −-N contents and leaching, however, both were inhibited by dissimilatory nitrate reduction to ammonium (DNRA) and assimilatory nitrate reduction to ammonium (ANRA) in the two soils. Further, NO 3 −-N leaching was enhanced by biogas slurry in yellow soil by promoting nitrification and preventing DNRA and ANRA; but it was not affected in calcareous soil. Accordingly, yellow soil has higher NO 3 −-N leaching than calcareous soil. The leaching can be regulated by the DNRA and ANRA in both soils, which were overlooked relative to nitrification but probably reactive to slurry, warranting further exploration. [Display omitted] • Yellow soil has higher nitrate leaching than calcareous soil with slurry application. • Slurry raises yellow soil nitrate leaching via nitrification and nitrate reduction. • Slurry increases calcareous soil nitrate but not the leaching via nitrate reduction. • Nitrification controls yellow soil nitrate leaching but not that in calcareous soil. • Nitrate reduction as DNRA and ANRA regulate both soils' nitrate leaching. [ABSTRACT FROM AUTHOR]

Highlights • The fluctuation of the reflected intensity from a group of discrete particles in turbulence atmospheric model. • Log-amplitude covariance function of the reflected waves from two particles at different heights in turbulent atmosphere is deduced. • A fast algorithm to calculated the scintillation index of the received field is developed based on the Mote Carlo method. Abstract The intensity fluctuation of the reflected field from a group of discrete particles illuminated by a laser beam in turbulent atmosphere is investigated here. First, the expression of the correlation function of the received intensity is derived by dividing the illuminated space into a number of sub blocks. Then, the log-amplitude covariance function of the reflected waves from two particles at different heights in a turbulent atmosphere is deduced using the Rytov method. The dimensions of the sub blocks are discussed based on the 3D log-amplitude covariance function, and the normalized variance of the received intensity is calculated and discussed based on the sub blocks. Results show that the normalized variance is mainly affected by the cross section area of the illuminated space, whereas the latter is greatly influenced by the position of the received point and the width of the transmitting beam. [ABSTRACT FROM AUTHOR]

A series of Mg 3 Al 1−x Ce x O composite oxide catalysts were prepared by co-precipitation for the transesterification of ethylene glycol to ethylene carbonate. The characterization results revealed that the addition of cerium changed the acid-base properties of the catalyst and that the strong basic sites on the catalyst surface played an important role in the reaction. The Mg 3 Al 0.9 Ce 0.1 O catalyst showed the highest catalytic activity (ethylene carbonate yield 98.1%). Compared with pure Mg-Al oxide, the appropriate addition of Ce was conducive to improving the surface basicity and adsorbed oxygen content of the catalyst. Additionally, the reaction process of the formation of ethylene glycol hydroxyl group with the alkoxy anion formed by the catalyst attacking the carbonyl carbon of nucleophilic dimethyl carbonate to form an adsorption intermediate (HEMC) on the catalyst surface for further intramolecular rearrangement to form ethylene carbonate was confirmed by operando infrared spectroscopy. The reaction kinetics shows that the reaction conforms to the second-order kinetic equation, and the activation energy is 53.71 kJ·mol−1. Catalytic stability in a fixed-bed reactor was studied. After a long cycle of use (150 h), the yield of ethylene carbonate was stabilized at about 89.0%. [Display omitted] • A novel Mg 3 Al 1−x Ce x O composite oxide catalyst was prepared by coprecipitate method. The catalyst was used in the carbonylation of ethylene glycol and dimethyl carbonate to synthesize ethylene carbonate. The yield of ethylene carbonate reached 98.1%. • The catalyst was continuously amplified for 150 h using a fixed-bed. The yield of ethylene carbonate is stable at about 89.0%, and the catalyst has good long-term durability and stability. • The interaction between cerium species and Mg-Al oxides and acid-base synergies play an important role in the reaction. • The reaction path and intermediates of ethylene carbonate synthesis were studied by operando IR spectroscopy. [ABSTRACT FROM AUTHOR]

The multi-body hinge-barge wave energy converter has the advantages of high capture width ratio and wide bandwidth of wave-excited response, which is the current hotspot of studies on wave energy converters. However, to correctly and throughfully analyse its overall efficiency, hydrodynamics, mechanical dynamics and electrical dynamics, a fully coupled wave-to-wire approach by numerical analysis and physical validation is required, which is not concerned by current studies. The work conducted in this study improves the overall wave-to-wire efficiency by optimising the mooring system, the structure and geometry of the primary capture system, and the external electric load. Results show that an optimised prototype achieves a wave-to-wire efficiency up to 25 % in flume experiments, where a significant improvement of 53 % is contributed by employing a damping plate to the right barge. Numerical results indicate that a wave-to-wire efficiency of up to 53 % is obtained by further optimisation of the damping plate. • A wave-to-wire model is developed for a hinge-barge wave energy converter, verified by flume experiments. • Adding a damping plate to the right barge can significantly improve power generation. • High wave-to-wire efficiency of 25.02% is experimentally achieved by a prototype. • High wave-to-wire efficiency of 53% is numerically achieved by optimisation. [ABSTRACT FROM AUTHOR]

Soy protein hydrolysates (SPH) and their blends with xanthan gum (SPH/XG), produced via a combination of enzymatic hydrolysis and heat-shearing treatment, were used as fat replacers in the production of reduced fat ice cream. The physicochemical properties of soy protein isolate (SPI) and its hydrolysates with 1% (SPH1) and 5% degree of hydrolysis (SPH5) were characterized. The results suggested that enzymatic hydrolysis produced a lower average molecular weight ( M w ), particle size, viscosity, and water holding capacity compared with SPI, but increased the solubility, oil holding capacity, and foaming capacity. The particle size of the SPH5/XG fat replacer was significantly reduced by enzymatic hydrolysis and heat-shearing treatment. In addition, the incorporation of XG could stabilize the composite system, as indicated by rheology measurement. The sensory properties of ice creams were correlated with the physicochemical measurements. The results illustrated that 50% fat-substituted ice cream with SPH5/XG (96:4) had an appearance, taste, and texture similar to that of 10% full fat ice cream, and the overall performance was acceptable among the low-fat ice cream samples. Therefore, SPH/XG treated by enzymatic hydrolysis and microparticulation is an alternative choice as a fat replacer in typical ice cream production. [ABSTRACT FROM AUTHOR]

A model of the log-amplitude covariance function of a Gaussian beam propagating through the atmospheric turbulence is proposed based on the Rytov Method. The intensity correlation function of the reflected field from a rough surface is analyzed with the extended Huygens-Fresnel principle. The covariance and variance and residual scintillation index of the received intensity are calculated for the cases of a collimated beam and a focused beam. It is found that the effect of the log-amplitude covariance of the turbulence along the forward path plays a large role in the intensity fluctuation of the received wave. The size of the laser spot on the target has an “aperture effect” on the covariance and variance of the received intensity. [ABSTRACT FROM AUTHOR]

Ocean waves are a promising source of renewable energy. In this paper, we briefly introduce the characteristics of ocean wave energy and summarize the principles of harvesting ocean energy by wave energy converters. We also review the prototypes or commercial devices deployed in real sea between 2005 and July 2016. In addition, we present the concept of a wave-to-wire model as a framework to systematically review and compare control strategies for wave energy conversion systems, with a focus on the numerical and experimental validation. [ABSTRACT FROM AUTHOR]

In recent years, the application of convolutional neural networks (CNNs) and graph convolutional networks (GCNs) in hyperspectral image classification (HSIC) has achieved remarkable results. However, the limited label samples are still a major challenge when using CNN and GCN to classify hyperspectral images. In order to alleviate this problem, a double branch fusion network of CNN and enhanced graph attention network (CEGAT) based on key sample selection strategy is proposed. First, a linear discrimination of spectral inter-class slices (LD_SICS) module is designed to eliminate spectral redundancy of HSIs. Then, a spatial spectral correlation attention (SSCA) module is proposed, which can extract and assign attention weight to the spatial and spectral correlation features. On the graph attention (GAT) branch, the HSI is segmented into some super pixels as input to reduce the amount of network parameters. In addition, an enhanced graph attention (EGAT) module is constructed to enhance the relationship between nodes. Finally, a key sample selection (KSS) strategy is proposed to enable the network to achieve better classification performance with few labeled samples. Compared with other state-of-the-art methods, CEGAT has better classification performance under limited label samples. [ABSTRACT FROM AUTHOR]

The intensity fluctuation of the reflected field from a diffuse circular plate with a hard edge in turbulence is investigated by combining the Rytov theory and the Extended Huygens-Fresnel principle. The normalized covariance and variance of the reflected intensity are formulated and calculated. The enhancement effect on the normalized variance is discussed around the backscattering direction, which disappears rapidly as the receiving point moves away from the transmitting center. The “averaging effect” of the target aperture is also discussed, and the results show that the normalized variance and the backscattering enhancement effect decreases with increasing target size. [ABSTRACT FROM AUTHOR]

Direct synthesis of diethyl carbonate (DEC) from propylene oxide, CO 2 and ethanol via coupling reaction over a heterogeneous catalyst was demonstrated. In this work, a cross linked poly(ionic liquid) containing poly(1-vinyl-3-ethylimidazolium bromide)(PVEImBr) moiety was prepared via a free radical polymerization. Meanwhile, the MgO nanoplatelet with abundant basic sites was prepared, which was combined with PVEImBr to form a composite catalyst of PVEImBr/MgO. N 2 physisorption, TG, XRD, SEM, CO 2 -TPD and FT-IR were conducted to thoroughly characterize the structure and texture of the catalysts. The as-prepared heterogeneous catalyst, which simultaneously possessed the dual function of nucleophilicity and basicity, was used in the coupling reaction of propylene oxide, CO 2 and ethanol to synthesize diethyl carbonate and propylene glycol. The composite catalyst could promote the reaction with high efficiency, and a good catalytic performance of 54.4% diethyl carbonate yield and 59.8% propylene glycol yield could be achieved. The 1 H NMR and DFT calculation disclosed that greatly faster reaction rate was ascribed to the synergistic effect between the Br Ɵ anion of PVEImBr and hydroxyl group of ethanol. Accordingly, a mechanism of the sequential reaction consisting of cycloaddition and transesterification steps was proposed. [ABSTRACT FROM AUTHOR]

A series of Cu/SiO 2 -AE catalysts with different copper loadings were prepared by ammonia evaporation method with silica sol as the silica source. The systematic catalyst characterization revealed that different proportions of Cu 0 and Cu + species co-existed in the Cu/SiO 2 -AE catalysts, which derived from the reduction of CuO and copper phyllosilicate, respectively. The as-prepared catalysts were employed in the hydrogenation of ethylene carbonate (EC) to co-produce methanol (MeOH) and ethylene glycol (EG). Among the catalysts investigated, the 10%Cu/SiO 2 -AE catalyst with a moderate copper loading exhibited better catalytic activity and product selectivities, which was mainly ascribed to the synergetic effect of Cu 0 and Cu + species and the suitable proportion of Cu + /(Cu + +Cu 0 ). It was proposed that the Cu 0 species promoted the dissociation of H 2 , while Cu + species adsorbed on the carbonyl group of EC. Under the optimized conditions, EC conversion of 100%, MeOH selectivity of 70.8% and EG selectivity of 98.0% were obtained over the 10%Cu/SiO 2 -AE catalyst. The catalyst reusability results showed that the agglomeration of Cu and Cu 2 O particles was responsible for the gradually decreasing activity of 10%Cu/SiO 2 -AE catalyst along with recycling runs. [ABSTRACT FROM AUTHOR]

Improving capacity utilization (CU) is a critical way for China to promote economic transformation and achieve sustainable development. As a market-based environmental regulation proposed to achieve a low-carbon economy and green transformation, whether emission trading system (ETS) can improve CU deserves an in-depth study. We conduct an empirical study by constructing a multi-period difference-in-differences model with 1,037 Chinese A-share listed firms from 2004 to 2020 as the research sample. The result shows that the ETS can significantly improve CU, which still holds after a series of robustness tests. The mechanism analysis shows that the ETS improves CU through three mechanisms: stimulating green innovation, restricting over-investment, and alleviating financing constraints. Based on the heterogeneity analysis, the improvement of CU by ETS is greater among listed firms in heavy-polluting industries, with good ESG performance, excess leverage, and central state ownership. Our study supports the global implementation of the ETS and provides ideas for resolving overcapacity in the context of global decarbonization. [ABSTRACT FROM AUTHOR]

Tool coatings exhibit different tribological behavior when cutting dissimilar materials, and understanding the differences is crucial for their service life. In this study, CrAlN/TiSiN multilayer coating was deposited by the arc ion plating technique, and its microstructure, load-bearing capacity, and toughness were investigated as well as the tribological behavior of the coating sliding against 7A09 Al alloy and GCr15 bearing steel at different temperatures. The results indicated a high fluctuation in the friction coefficient between the coating and 7A09 Al alloy above 150 °C, and the coating exhibited a negative wear rate. The friction coefficient between the coating and GCr15 bearing steel shows a decreasing trend above 150 °C, and the wear surface of the coating showed a smooth morphology. [ABSTRACT FROM AUTHOR]

Wave-based electricity generation is attracting increasing attention to address the long-term power supply problem of offshore marine observation buoys. To achieve continuous and real-time measuring of the marine environment, reliable wave energy harvesting technologies with high efficiency are urgently needed. For that purpose, a new marine observation buoy with a built-in wave-excited energy harvester was proposed in this study. A small-scale proof-of-concept prototype was designed, fabricated, and tested in a wave flume. A fully coupled mathematical model of the system with a mooring system was presented, and simulation results were validated by experimental data. The dynamics and the power performance of this novel concept under regular waves were investigated, considering the influence of the mooring system and electric load. Experimental results from a wave flume indicated that a time-averaged electric power of 160 mW was obtained under a regular wave with a height of 6. 0 cm and a period of 1. 0 s when the electric load for the wave-powered observation buoy is 310 Ω , and corresponding wave-to-wire efficiency is 14. 3 %. Numerical simulations and physical experiments have solidly demonstrated the feasibility of this novel wave-powered marine observation buoy. • A new wave-powered marine observation buoy with a built-in harvester was developed. • A test rig was designed for the dry test of the power take-off system. • A time-averaged electric power of 160 mW was achieved under a flume wave of 6 cm. • High wave-to-wire efficiency of 14. 6 % was achieved by the proposed system. [ABSTRACT FROM AUTHOR]

[Display omitted] • The novel polyether materials were synthesized by cationic ring-opening controllable polymerization of 1,2-butylene oxide (BO) with tetrahydrofuran (THF). • The poly(1,2-butylene oxide- stat -tetrahydrofuran)s has a super high viscosity index (≥198) and low pour point (≤-53 °C), which can be used as a base oil and additives in the field of high-performance lubricants. Aliphatic polyethers are synthesized byring-opening polymerization (ROP) of the most common epoxide monomers, such as ethylene oxide (EO) and propylene oxide (PO). 1,2-Butylene oxide (BO) and tetrahydrofuran (THF) are potentially extended ROP monomers, which can give polyether unique properties. In this work, a series of poly(1,2-butylene oxide- stat -tetrahydrofuran)s (PBO- stat -PTHFs) with M n of 900–3700 g·mol−1 were synthesized by cationic ring-opening polymerization (CROP) of BO with THF using strong Lewis acid Rare Earth triflates (RE(OTf) 3) as catalysts and diols as an initiator at room temperature. PBO- stat -PTHFs product with yield up to 90 %, narrow polydispersity of Đ <1.30, and molar ratio of PBO to PTHF 1:1 were obtained. The copolymerization process was studied by in-situ IR and 1H NMR spectroscopy analysis, and the results showed that PBO- stat -PTHF is a statistical copolymer. The early stage of the polymerization reaction was dominated by the activated chain end mechanism (ACEM), which incorporates a large amount of THF into the polymer chains. However, the late stage of the polymerization reaction was dominated by the activated monomer mechanism (AMM), which incorporates a large amount of BO into the polymer chains. Most PBO- stat -PTHFs have a suitable M n range, super high viscosity index (≥198) and low pour point (≤-53 °C), which can be used as a lubricant base oil and additives. In addition, PBO- stat -PTHFs have excellent miscibility with polyalphaolefin (PAO), which could significantly improve the PAO viscosity index. This study provides a mild route to construct high-performance copolyether materials through cationic ring-opening controllable polymerization. [ABSTRACT FROM AUTHOR]

The degradation of tetracycline over Fe 3 O 4 catalyst was studied by using a coupled ultrasound/heterogeneous Fenton process. The effects of some key reaction parameters, the evolution of toxicity, and the reaction mechanism were investigated. Experimental results showed that the stability of catalyst was significantly improved when ultrasound was employed. Under optimal conditions, 93.6% of tetracycline was removed after 60 min of treatment. The removal efficiency of the total organic carbon (TOC) at 60 min was 31.8%. The surface hydroxyl radicals were identified as the major reactive species during the oxidation process. Toxicity tests with Daphnia magna indicated that the toxicity of the solution increased during the first 60 min and then decreased as the oxidation proceeded. [ABSTRACT FROM AUTHOR]

Wave energy converters are devices that capture the energy carried by ocean waves and convert it into electricity, and their performance is significantly influenced by the geometric shapes of harvesters and the control strategies of power take-off systems. This paper presents a hybrid methodology to improve conversion efficiency in realistic sea states measured from an intended deployment site, taking into account the full coupling of ocean waves, geometric shapes of wave energy harvesters, and control strategies of power take-off systems. The proposed hybrid approach employs a control-strategy-informed optimization routine to select optimal/suboptimal geometries at the design stage, then employs different control strategies for the power take-off system at the operation stage. In numerical case studies, the proposed hybrid methodology is applied to a direct-driven point-absorber type wave energy converter, where its geometric shape is optimized, informing an optimal linear passive control strategy at the design phase. Simulation results indicate that the concave shape has the best energy harvesting performance. A high capture width ratio of 428% is achieved for the found optimum concave shape that employs an optimal linear active control strategy, in a sea state with a significant wave height of 1.6 m and an average period of 5.5 s. • Asymmetric and axisymmetric arbitrary geometries are optimized. • Optimum geometry has a concave shape. • Motion constraints are considered in control strategies. • A high capture width ratio of 428% is achieved. [ABSTRACT FROM AUTHOR]

The effects of boron content on the glass-forming ability, mechanical and elastic properties in Co 92 − x B x Ta 8 (at.%, x = 30, 32.5, 35, and 37.5) bulk glassy alloys were investigated. Among these alloys studied, the Co 59.5 B 32.5 Ta 8 alloy exhibits the highest glass-forming ability, which could form a glassy rod at least 3 mm in diameter by the copper mold casting method. It is found that the plasticity of those glassy alloys increases with decreasing boron content. The plastic strains for the Co 59.5 B 32.5 Ta 8 and Co 62 B 30 Ta 8 BMGs are up to ∼2.1% and ∼2.5%, respectively. The decrease of shear modulus with decreasing boron content results in the increase of Poisson’s ratio, which is responsible for the improved plasticity. In addition, the strength of the ductile glassy alloys remains very high at above 5000 MPa, although enhancing plasticity is accompanied by the loss of some strength. The present results show that Co–B–Ta bulk metallic glass with good glass-forming ability and significant plasticity as well as ultrahigh strength can be synthesized by adjusting alloy composition. [ABSTRACT FROM AUTHOR]

Graph-based classification algorithms have gained increasing attention in semi-supervised classification. Nevertheless, the graph cannot fully represent the inherent spatial distribution of the data. In this paper, a new classification methodology based on the spatial-spectral Label Propagation is proposed for semi-supervised classification of hyperspectral imagery. The spatial information was used in two aspects: on the one hand, the spatial features extracted by a 2-D Gabor filter were stacked with spectral features; on the other hand, the width of the Gaussian function, which was used to construct graph, was determined with an adaptive method. Subsequently, the unlabeled samples from the spatial neighbors of the labeled samples were selected and the spatial graph was constructed based on spatial smoothness. Finally, labels were propagated from labeled samples to unlabeled samples with spatial-spectral graph to update the training set for a basic classifier (e.g., Support Vector Machine, SVM). Experiments on four hyperspectral datasets show that the proposed Spatial-Spectral Label Propagation based on the SVM (SS-LPSVM) can effectively represent the spatial information in the framework of semi-supervised learning and consistently produces greater classification accuracy than the standard SVM, the Laplacian Support Vector Machine (LapSVM), Transductive Support Vector Machine (TSVM) and the Spatial-Contextual Semi-Supervised Support Vector Machine (SCS 3 VM). [ABSTRACT FROM AUTHOR]

This paper performs an investigation of power performance and techno-economic performance of wave power farms in realistic wave climates, where hydrodynamic interaction and influence of control strategies employed by power take-off systems are fully considered in mathematical modeling and numerical analysis. This is of great significance for a commercial wave power farm operated in a specific sea site over a long time of years, as wave energy converters will encounter a wide range of sea states, which requires that associated power take-off systems of individual units must be controlled accordingly to maximize the converted energy and to reduce the levelized cost of energy (LCOE). To that end, a fully-coupled numerical model, where the power take-off systems of wave energy converters are coordinately controlled/tuned for each sea state by employing an optimal linear passive control strategy and an optimal active control strategy, respectively. Numerical results show that power performance and LCOE of wave power farms vary over wave climates, and machinery constraints of power take-off force must be considered. Globally coordinated control of wave power farms by employing a constrained optimal linear active control strategy yields a LCOE of 0. 17 − 0. 54 $/kWh and increases the annual energy generation at least three times in specific wave climates of China, United States, Australia and Ireland. • Full hydrodynamic interaction of individual wave energy converters is considered. • Energy generation of wave power farms in realistic wave climates is maximized. • Individual wave energy converters are coordinately controlled. • Machinery constraints of power take-off systems are considered. [ABSTRACT FROM AUTHOR]

[Display omitted] • Highly dispersed Ru NPs on N-doped carbon with high surface area. • Superior performance of nitrobenzene hydrogenation at room temperature. • N-doping was crucial for regulating electron environment of Ru. • Ru-pyrrolic-N x enhanced nitrobenzene adsorption and H 2 dissociation. • Ru/N-doped exhibited superior performance for various nitroaroamtic compounds. An efficient catalyst for chemoselective hydrogenation of nitroaromatics to produce aromatic amines under mild conditions is highly desirable. In this work, a series of N-doped carbon (NC-x) with high nitrogen contents were firstly synthesized by pyrolysis of 1-butyl-3-vinylimidazolium bromide-co-acrylonitrile with a template of g-C 3 N 4. Furthermore, Ru/NC-x catalysts were successfully prepared by ultrasonic-assisted impregnation method. The catalysts were characterized by various methods in detail, e.g.X-ray diffraction, N 2 physical adsorption-desorption, Transmission electron microscopy, Raman spectra, Scanning electron microscopy and H 2 temperature programmed reduction. Characterization results revealed that N-doping on carbon contributed to the high dispersion of Ru nanoparticles and resulted in the forming of the electron-deficient of Ru species. Nanosheet Ru/NC-2 with high N-doping content of 28 wt% exhibited superior performance under room temperature, i.e., nitrobenzene conversion >99.0% and aniline selectivity 98.4%. Kinetic study indicated that the hydrogenation of nitrobenzene over Ru/NC-2 was the first-order kinetics with an intrinsic activation energy of 43.7 kJ/mol. Density functional theory calculation results suggested that Ru-N x species, especially, Ru-pyrrolic-N facilitated nitrobenzene adsorption and H 2 dissociation, resulting in enhanced catalytic performance. In addition, the excellent stability of Ru/NC-2 made it essentially reserved for 410 h in the fixed-bed reactor. Moreover, Ru/NC-2 exhibited superior performance for the hydrogenation of various nitroaromatics to corresponding aromatic amines. This work could provide meaningful guidance on designing effective and stable catalyst for chemoselective hydrogenation of nitroaromatics to aromatic amines under mild conditions. [ABSTRACT FROM AUTHOR]

Bimetallic Fe-Co/GAC (granular activated carbon) was prepared and used as heterogeneous catalyst in the ultrasound enhanced heterogeneous activation of peroxydisulfate (PS, S 2 O 2− 8 ) process. The effect of initial pH, PS concentration, catalyst addition and stirring rate on the decolorization of Acid Orange 7 (AO7) was investigated. The results showed that the decolorization efficiency increased with an increase in PS concentration from 0.3 to 0.5 g/L and an increase in catalyst amount from 0.5 to 0.8 g/L. But further increase in PS concentration and catalyst addition would result in an unpronounced increase in decolorization efficiency. In the range of 300 to 900 r/min, stirring rate had little effect on AO7 decolorization. The catalyst stability was evaluated by measuring decolorization efficiency for four successive cycles. [ABSTRACT FROM AUTHOR]

Abstract: The solid base derived from abundant waste slag was prepared by co-precipitation method, and tested in the diethyl carbonate synthesis via ethanolysis of ethyl carbamate. Compared to the previous reports, much higher catalytic activity and turnover frequency (TOF) of 2926mgDEC/gcat ·h−1 could be achieved. Accordingly, the correlation between the catalyst basic properties and the catalytic performance revealed that the appropriate strong basic sites facilitated the formation of DEC. Moreover, the catalyst could be readily recycled and reused for several times through facile calcination. [Copyright &y& Elsevier]

Highlights: [•] The combination of ultrasound with zero valent iron activated persulfate process was proposed. [•] Decolorization of Acid Orange 7 under different systems was carried out. [•] The effect of operating parameters on the decolorization by US/Fe0/PS process was investigated. [•] The changes of UV–vis spectra and TOC during the treatment were monitored. [ABSTRACT FROM AUTHOR]

Highlights: [•] The DEC synthesis from CO2, EO and ethanol was attempted for the first time. [•] KI/EtONa as binary catalyst system exhibited higher catalytic performance. [•] This strategy can be successively expanded to terminal epoxides. [•] This method exhibited promising applications on an industrial scale. [ABSTRACT FROM AUTHOR]

Abstract: The binary zinc–yttrium oxides were prepared by co-precipitation method, characterized and tested in the synthesis of DMC via transesterification of ethylene carbonate with methanol. The catalytic results showed that the catalyst with Zn/Y molar ratio of 3 and calcined at 400°C exhibited superior catalytic activity, corresponding to TOF of 236mmol/gcat h. Appropriate content of yttrium in the catalyst enhanced the catalytic activity remarkably. Moreover, the abundance of medium basic sites (7.2

Abstract: Lanthanum oxide catalyst prepared by precipitation method and calcined at 600°C exhibited better catalytic activity in the catalytic synthesis of glycerol carbonate from glycerol and urea with TOF up to 1506mmol/g·h. It was proposed that the lanthanum oxide catalyst with more strong basic sites (Td >400°C) exhibited higher catalytic activity. Accordingly, the catalyst containing appropriate amount of La2O2CO3 phase exhibited higher catalytic activity. Moreover, the recycling experiments demonstrated that the catalytic activity can be essentially preserved during the recycling tests investigated. [Copyright &y& Elsevier]

Abstract: An improved unified description of the dependence of the charge-carrier mobility on temperature, carrier density, and electric field in disordered organic semiconductors is proposed based on the Arrhenius temperature dependence and non-Arrhenius temperature dependence . The improved description of the mobility can quite well fit the numerical solution of the master equation at both the low densities and high densities, the latter of which cannot be accurately described using the model introduced by Pasveer et al. . Experimental current–voltage characteristics in devices based on organic semiconductors are also excellently reproduced with this improved description. Finally, we calculate and analyze the distribution of the charge-carrier density and electric field with position in polymer layer for two organic semiconductors in detail by using the improved description. [Copyright &y& Elsevier]

Convolutional neural networks (CNNs) exhibit excellent performance in hyperspectral image classification (HSIC) and have attracted significant interest. Nevertheless, the common CNN-based classification techniques still suffer from the following drawbacks. 1) Although deep CNNs can effectively extract features from hyperspectral images, a network that is too deep often leads to negative effects such as overfitting, vanishing gradients, and decreased accuracy. 2) Most of these models for HSIC do not fully consider the strong complementarity and correlation between features at different levels. To address these issues, firstly, a self-regularization parameter correction non-monotonic activation function, called Lush, was first proposed. Then, this study proposes a novel bias update method that can update network bias parameters more efficiently. On the basis of the above, a Lush multi-layer feature fusion polarization network (LMFFBNet) for hyperspectral image classification was proposed in this study. It designs a new after-melting technology to fuse deep and shallow features in multiple stages and layers, which can obtain more discriminative features, thereby improving the classification performance of hyperspectral images. Extensive experiments on five challenging datasets (Indian Pines, Pavia University, Kennedy Space Center, Salinas Valley, and Houston) have demonstrated that compared to some state-of-the-art methods, the proposed LMFFBNet method can provide better classification performance for hyperspectral images and has strong robustness. This fully proves the effectiveness of the LMFFBNet method. [ABSTRACT FROM AUTHOR]

• The speckle carries a large amount of target information, the target features can be obtained by measuring the speckle. • There are few reports regarding the echo speckle characteristics of vortex beams currently. • The echo speckle characteristics of the Laguerre Gauss (LG) vortex beams scattered from random rough targets were examined. In this study, the echo speckle characteristics of the Laguerre-Gauss (LG) vortex beams scattered from random rough surface targets were examined based on the Rytov Approximation Theory. In addition, the expressions of the intensity correlation and coherence functions, along with the normalized intensity variances of the speckle fields, were derived. The coherent lengths and scintillation indexes of the speckle fields were then numerically simulated, and the speckle characteristics of the Laguerre-Gauss vortex beam were compared with those of the Gaussian beams. The effects of the topological charges, rough target radii, initial beam radii, turbulence intensities, and roughness degrees of the targets on the speckle characteristics of the LG vortex beams were analyzed. This study's results showed that in the weak turbulence regions, the target characteristics were the main influencing factors of the speckle fields. Meanwhile, in the strong turbulence regions, the turbulence effects were the main influencing factors of the speckle fields. The influence effects of turbulent atmosphere and target characteristics on the coherent lengths and scintillation effects of the vortex beam echoes were observed to be less than those of the Gaussian beams. In addition, the influence effects of the turbulent atmosphere on coherent lengths and scintillation effects of the vortex beams echoes with small topology were found to be minimal. Therefore, this study's results can potentially provide theoretical and technical guidance for the future applications of laser target detection, target recognition, and speckle measurement processes in space. [ABSTRACT FROM AUTHOR]

This paper aims to investigate electric dynamics and improve electric power generation of an isolated wave energy converter that uses a linear permanent magnet generator as the power take-off system, excited by regular or irregular waves. This is of significant concern when considering actual operating conditions of an offshore wave energy converter, where the device will encounter different sea states and its electric load needs to be tuned on a sea-state-to-sea-state basis. To that end, a fully coupled fluid-mechanical-electric-magnetic-electronic mathematical model and an optimization routine are developed. This proposed time-domain wave-to-wire model is used to simulate the hydrodynamic and electric response of a wave energy converter connected to specific electric loads and also used in an optimization routine that searches optimal resistive load value for a wave energy converter under specific sea states. Sample results are presented for a point-absorber type wave energy converter, showing that the electric power generation of a device under irregular waves can be significantly improved. • A wave-to-wire model is developed for a point-absorber type wave energy converter (PAWEC). • A new optimization procedure that identifies optimal electric load is proposed. • Hydrodynamic and electric performance of a wave energy converter under random sea states are investigated. [ABSTRACT FROM AUTHOR]

• A method was developed to achieve desired liposome densities in cryo-EM images of liposomes even at extremely low liposome concentrations (e.g. in nanomolar range). • The new method enables cryo-EM data collection for membrane proteins reconstituted into liposomes which could not be concentrated at a concentration high enough for standard cryo-EM sample preparation. • The saturation of carbon regions (i.e. monolayer coverage) determines whether liposomes go into holes for cryo-EM images, while the accumulation of liposomes in carbon regions (i.e. multilayer adsorption) determines how many liposomes go into holes. • The new method is also applicable to prepare cryo-samples of other biological samples. Liposomes are widely used as delivery systems in pharmaceutical, cosmetics and food industries, as well as a system for structural and functional study of membrane proteins. To accurately characterize liposomes, cryo-Electron Microscopy (cryo-EM) has been employed as it is the most precise and direct method to determine liposome lamellarity, size, shape and ultrastructure. However, its use is limited by the number of liposomes that can be trapped in the thin layer of ice that spans holes in the perforated carbon film on EM grids. We report a long-incubation method for increasing the density of liposomes in holes. By increasing the incubation time, high liposome density was achieved even with extremely dilute (in the nanomolar range) liposome solutions. This long-incubation method has been successfully employed to study the structure of an ion channel reconstituted into liposomes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Tandem hydrogenation of nitrobenzene to alicyclic amines was realized in mild conditions (80 °C, 1 MPa H 2). • The hydrogenation was significantly promoted by Pt-Ru dual-site catalyst with a product yield rate of 357.9 mmol/g metal ·h. • Alkaline air-exfoliated C 3 N 4 superseded the hazardous alkali liquor in curbing unnecessary adsorption of intermediate. • Selective adsorption and inter-site H spillover enhanced by bimetal synergy achieved highly efficient hydrogenation. Green production of alicyclic amines is highly desirable but of great challenges. Herein, an efficient one-pot synthesis of alicyclic amines from nitroaromatics was realized with a Pt-Ru bimetallic catalyst. 0.5 %Pt-2.5 %Ru supported on an air-exfoliated C 3 N 4 nanosheet achieved 100.0 % conversion of nitrobenzene (NB) with 98.9 % selectivity of cyclohexylamine (CHA) under mild conditions of 80 °C and 1 MPa, attaining a yield rate for alicyclic amine of 357.9 mmol/g metal ·h. Our study has shown hydrogenation of nitro group and aromatic ring took place in sequence over Pt and Ru in a tandem manner due to the highly selective adsorption. During the hydrogenation, the homolytic dissociation of H 2 occurred on the bimetal sites and the inter-site hydrogen spillover between the bimetal played a crucial role. C 3 N 4 nanosheet as the support not only gave rise to the uniform dispersion of metal nanoparticles, but was crucial in curbing the unnecessary adsorption of intermediate aromatic amines. Our study has also demonstrated the good stability and wide applicability of the Pt-Ru/C 3 N 4 -air catalyst for the hydrogenation of various nitroaromatic derivatives. [ABSTRACT FROM AUTHOR]

• CeO 2 H, which is prepared using hydrogen peroxide assisted precipitation, is abundant in both acid and base double sites. • CeO 2 H acid-base dual functionality is beneficial for efficient synthesis of HDC, with a yield of up to 96% and a TOF value of 6.66 g HDC g CeO2 H −1 h−1. • The activity of the CeO 2 H catalyst could be retained within five cycles. • CeO 2 H has good catalytic effect on the carbonylation of aliphatic and alicyclic substrates. The carbonylation of 1,6-hexanediamine (HDA) is an important method for the production of dimethyl hexane-1,6-dicarbamate (HDC), which is of great significance for the non-phosgene synthesis of hexamethylene-diisocyanate. This research focuses on the synthesis of HDC through the methoxycarbonylation of HDA using methyl carbamate as a carbonyl source. The study investigates the utilization of CeO 2 catalyst prepared via H 2 O 2 assisted precipitation. Various characterization techniques, including N 2 physical adsorption and desorption, SEM, TEM, XRD, NH 3 TPD, CO 2 TPD, and XPS are employed to analyze the texture and structure of CeO 2 catalysts prepared through different methods. In situ FTIR experiments are conducted to monitor the potential process of the carbonylation reaction. The results of the in situ FTIR spectroscopy clearly indicate the formation of polyurea as an intermediate compound, which subsequently converts into HDC. The findings demonstrate that CeO 2 prepared using the hydrogen peroxide precipitation method exhibits a larger specific surface area, stronger acid-base properties, and a higher content of surface-adsorbed oxygen. These characteristics are favorable for the carbonylation reaction. Under optimized conditions, the HDC yield reaches 96.0% with complete conversion of HDA. The catalyst's activity essentially maintained throughout ten cycles. Additionally, a substrate versatility study reveals that CeO 2 exhibits excellent catalytic properties for synthesizing a range of aliphatic and alicyclic dicarbamates. [Display omitted] [ABSTRACT FROM AUTHOR]

The catalytic synthesis of dimethylhexane-1,6-dicarbamate (HDC) from 1,6-hexanediamine (HDA) and dimethyl carbonate (DMC) over a series of homogeneous catalysts (e.g., metallic nitrates and acetates) were investigated. Mn(OAc) 2 was found to be the most effective catalyst for this reaction. Under the optimum reaction conditions (reaction temperature of 363 K, DMC-to-HDA molar ratio of 4:1, catalyst concentration of 7 wt% (based on HDA), and reaction time of 5 h), HDC yield can reach as high as 98.0% with HDA totally converted. Online in-situ Fourier Transform Infrared (FTIR) and Density Functional Theory (DFT) calculations were used together to investigate the interactions between Mn(OAc) 2 and substrates. The results indicated that both of HDA and DMC had interactions with Mn(OAc) 2 , but the energy barriers of the transition states (TS) of DMC (DMC-TS) was higher than that of HDA (HDA-TS), which meant that HDA was easier to interact with Mn(OAc) 2 to form new complex than DMC. The whole process can be proposed that, the new species II , which was formed by the interaction of HDA and Mn(OAc) 2 , attacked carbonyl carbon of DMC to generate intermediate HMC and finally to HDC. The experimental data and calculation results are in good agreement with each other. [ABSTRACT FROM AUTHOR]

Purpose Co-delivery of two or more drugs into the same cancer cells or tissues in the same nanocarriers provides a new paradigm in cancer treatment. In this study, two kinds of nanocarriers: lipid-polymer hybrid nanoparticles (LPNs) and polymeric nanoparticles (PNPs) were constructed and compared for co-delivery of cisplatin (DDP) and curcumin (CUR). Methods DDP and CUR loaded LPNs (D/C/LPNs) and PNPs (D/C/PNPs) were prepared. Two kinds of nanocarriers were characterized in terms of particle size, zeta potential, drug encapsulation efficiency (EE), and drug release. Their in vitro cytotoxicity and in vivo anti-tumor efficacy was studied on human cervix adenocarcinoma cell line (HeLa cells) and mice bearing cervical cancer model. Results Compared with D/C/PNPs, D/C/LPNs showed significantly higher cytotoxicity in vitro . D/C/LPNs also displayed the best antitumor activity than other formulations tested in vivo . Conclusions The results demonstrated that LPNs could improve the anticancer efficacy of drugs to higher levels than PNPs and free drugs, thus could serve as an effective drug system for targeted and synergistic co-delivery nanomedicine for cervical cancer chemotherapy. [ABSTRACT FROM AUTHOR]

Uridine diphosphate (UDP) glycosyltransferases (UGTs) involved in many metabolic processes and are essential for plant growth and development. Although UGTs proteins have been studied in many plants, the biological functions of UGT genes in cotton leaf senescence are still unknown. In the present study, we performed a genome-wide survey and identified 157 GrUGT , 152 GaUGT and 261 GHUGT genes in Gossypium raimondii , G. arboreum , and G. hirsutum , respectively, that were classified into 15 groups. Analysis of protein motif and gene structure demonstrated that structural and functional conservation occurred within same groups but diverged among the different groups. Gene duplication analysis indicated the different duplication ways happened between tetraploid G. hirsutum and the two diploid species. Whole genome or segmental duplications played a main role in the expansion of the GHUGT family in cotton, and experienced purifying selection during the long evolutionary process in cotton. Cis -acting regulatory elements analysis indicated that they were associated with complex hormone regulatory networks and the stress response. Additionally, to identify GHUGT candidate genes responsive to leaf senescence, we analyzed the expression patterns of GHUGT genes using our transcriptome data from two cultivars of upland cotton with contrasting tolerance to leaf senescence. Subsequently, gene expression profiling based on real-time quantitative PCR showed that selected GHUGT candidate genes might be involved in ABA and JA regulation. Through further functional verification, silencing GHUGT116 gene via VIGS (Virus-induced gene silencing) delayed dark-induced leaf senescence. Overall, the results provide useful and valuable information for understanding the evolution of cotton UGTs genes and the function in leaf senescence. [ABSTRACT FROM AUTHOR]