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Highly active Keggin-type silicotungstic acid (SiW12) with oxygen vacancy (Ov) defects was encapsulated into the magnetic floral N-doped carbon microspheres (γ-Fe2O3@NC-300) through the facile one-step air pyrolysis of the precursor comprising core–shell Fe3O4@polydopamine (Fe3O4@PDA) and SiW12 to prepare γ-Fe2O3@NC@SiW12-300. The fabricated catalysts were systematically characterized and subsequently employed for the oxidation desulfurization (ODS) of the model fuel. The magnetic floral γ-Fe2O3@NC@SiW12-300 catalyst exhibited nearly perfect catalytic activity, which under mild conditions could remove 100% amount of 4000 ppm DBT in model fuel within 20 min (0.03 g catalysts and n(H2O2)/n(S) of 2). The catalyst activity is mainly attributed to the high activity SiW12 with the Ov defect and its outstanding dispersibility in γ-Fe2O3@NC, along with the high number of exposed active sites. A selected catalyst, γ-Fe2O3@NC@SiW12-300, showed a noticeable turnover frequency (TOF) (110.07 h−1) and lower activation energy (38.79 kJ mol−1) in oxidative desulfurization (ODS) with good recyclability. HO˙ radical was found to be the active species involved in ODS as confirmed by the EPR and scavenger experiments. Additionally, the fabricated catalyst can be conveniently separated and recycled within an externally applied magnetic field. [ABSTRACT FROM AUTHOR]

Multi-agent formation control is an important part of distributed perception and cooperation, which is convenient to complete various complex tasks and would be a key research direction in the future. This paper reviews the corresponding problems of formation control and the existing centralized and distributed formation control strategies. In particular, we discuss four types of distributed formation control methods based on position and displacement in the global coordinate system and distance and bearing in the nonglobal coordinate system, respectively. Moreover, this paper analyzes affine formation which does not require the global coordinate system. Combined with the current practical applications of multi-agent systems, the latest research for the formation control of the unmanned aerial vehicle (UAV), unmanned ground vehicle (UGV), unmanned surface vehicle (USV) and autonomous underwater vehicle (AUV) is given. Finally, the challenges and opportunities in this burgeoning field are discussed. [ABSTRACT FROM AUTHOR]

Based on the ever-growing interest of heteroatoms (e.g., P, N, S, transition metals) doping into molybdenum carbide and graphene for electrochemical reactions, herein, a ternary phosphomolybdic acid-polyethyleneimine/graphene oxide nanocomposite as a suitable precursor was developed to not only uniformly hybridize molybdenum and carbon source to perform the controllable in situ growth of well-defined molybdenum carbide nanostructure on graphene by annealing, but also synchronously dope N and P atoms into molybdenum carbide crystal lattice and graphene. The as-prepared hybrid showed remarkable electrocatalytic activity and high stability for hydrogen evolution reaction in basic media, due to the following favorable features, i.e. a large accessible active sites afforded by the ultrafine molybdenum carbide, the heteroatoms doped, the regulated electronic structure, the balanced thermodynamics between hydrogen adsorption and desorption, the accelerated charge/mass transfer ability by the ultrathin and defective carbon layer, and the protection of molybdenum carbide by carbon layer. As a result, it only needed a small overpotential of 47 mV to drive 10 mA cm−2 and a low onset potential of 10 mV, as well as a small Tafel slope of 56.8 mV·dec−1, thus suggesting its promising potential for hydrogen evolution electrocatalyst. [Display omitted] • Mo 2 C were facilely prepared using only phosphomolybdic acid and polyethyleneimine. • Mo 2 C was in situ grown on graphene and synchronously doped by N and P atoms. • N, P–Mo 2 C/NPrGO displayed remarkable HER performances (η 10 = 47 mV). [ABSTRACT FROM AUTHOR]

• The selection range of the activation function could be expanded by the GLIT method. • A tolerance solution theorem based upon neural network system is given and proved. • The input could fall into the specified interval in the sense of probability. • The GLIT method is more suitable for high-dimension data. Weight initialization of neural networks has an important influence on the learning process, and the selection of initial weights is related to the activation interval of the activation function. It is proposed that an improved and extended weight initialization method for neural network with asymmetric activation function as an extension of the linear interval tolerance method (LIT), called 'GLIT' (generalized LIT), which is more suitable for higher-dimensional inputs. The purpose is to expand the selection range of the activation function so that the input falls in the unsaturated region, so as to improve the performance of the network. Then, a tolerance solution theorem based upon neural network system is given and proved. Furthermore, the algorithm is given about determining the initial weight interval. The validity of the theorem and algorithm is verified by numerical experiments. The input could fall into any preset interval in the sense of probability under the GLIT method. In another sense, the GLIT method could provide a theoretical basis for the further study of neural networks. [ABSTRACT FROM AUTHOR]

This paper presents a new control strategy for stochastic distribution shape tracking regarding non-Gaussian stochastic non-linear systems. The objective can be summarised as adjusting the probability density function (PDF) of the system output to any given desired distribution. In order to achieve this objective, the system output PDF has first been formulated analytically, which is time-variant. Then, the PDF vectorisation has been implemented to simplify the model description. Using the vector-based representation, the system identification and control design have been performed to achieve the PDF tracking. In practice, the PDF evolution is difficult to implement in real-time, thus a data-driven extension has also been discussed in this paper, where the vector-based model can be obtained using kernel density estimation (KDE) with the real-time data. Furthermore, the stability of the presented control design has been analysed, which is validated by a numerical example. As an extension, the multi-output stochastic systems have also been discussed for joint PDF tracking using the proposed algorithm, and the perspectives of advanced controller have been discussed. The main contribution of this paper is to propose: (1) a new sampling-based PDF transformation to reduce the modelling complexity, (2) a data-driven approach for online implementation without model pre-training, and (3) a feasible framework to integrate the existing control methods. [ABSTRACT FROM AUTHOR]

The energy efficiency and output power of a quantum thermoelectric system with multiple electric currents and only one heat current are studied. The system is connected to the hot heat bath (cold bath) through one terminal (multiple terminals). In such configurations, there are multiple thermoelectric effects coexisting in the system. Using the Landauer–Büttiker formalism, we show that the cooperation between the two thermoelectric effects in the three-terminal thermoelectric systems can lead to markedly improved performance of the heat engine. Such improvement also occurs in four-terminal thermoelectric heat engines with three output electric currents. Cooperative effects in these multi-terminal thermoelectric systems can considerably enlarge the physical parameter region that realizes high energy efficiency and output power. For refrigeration, we find that the energy efficiency can also be substantially improved by exploiting the cooperative effects in multi-terminal thermoelectric systems. All these results reveal a useful approach toward high-performance thermoelectric energy conversion in multi-terminal mesoscopic systems. [ABSTRACT FROM AUTHOR]

The annual saving rates of primary energy and operating cost of NH 3 and CO 2 heat pumps for seven food processes in four characteristic locations with different energy prices in the U.S. are analyzed. The modeled food processes include beer brewing, food pasteurization, fluid milk processing, cheese processing, vegetable and fruit canning, juice canning, and poultry slaughtering. The investigation focuses on the effects of the characteristics of the thermal demands, the location of the proposed systems, and the energy price structure on the savings of primary energy and the operating cost. The results indicate that the characteristics of the thermal demands are the most crucial factor. The energy price structure significantly impacts the operating cost-saving rate. The analysis shows that the annual savings of primary energy can achieve 32% in food pasteurization, 44% in beer brewing, and 35% in fluid milk processing. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mo 2 C nanoparticles was well-dispersed on N-doped graphene via in-situ carbonization of the PMo 12 -PEI/GO precursor. • Mo 2 C@NC/NrGO presented the maximum kinetic constant of 0.35 min−1 for ODS of liquid fuel with 4000 ppm of the initial S content. • The radical scavenging experiments revealed a ODS mechanism of HO• radicals. A new composite Mo 2 C@NC/NrGO, with very small and well-distributed molybdenum carbide (Mo 2 C) nanoparticles on N-doped graphene, was prepared via carbonization of the tricomponent composite PMo 12 -PEI/GO comprising phosphomolybdic acid (H 3 PMo 12 O 40 ·xH 2 O), polyethyleneimine (PEI), and graphene oxide (GO). The as-prepared Mo 2 C@NC/NrGO exhibited outstanding oxidative desulfurization (ODS) performance and achieved the ultra-deep desulfurization of liquid fuel under mild conditions, which was attributed to the synergistic effect of extraction and catalytic oxidation. In particular, catalytic oxidation played a dominant role, which originated from the excellent characteristics of Mo 2 C@NC/NrGO, such as the small size and even distribution of Mo 2 C on graphene, as well as the improved activation of oxidant by the electronic transfer of N-doped graphene to Mo 2 C. For oxidative desulfurization (ODS) of 4000 ppm of DBT, Mo 2 C@NC/NrGO showed the high kinetic constant (＞0.35 min−1), which can make 4000 ppm of DBT removed completely within 10 min. A HO• radical mechanism for oxidative desulfurization (ODS) of fuel oils was revealed on the basis of radical experiments and electron paramagnetic resonance (EPR). Moreover, the prepared catalyst presented a good recyclability for six runs with no significant loss of activities. Overall, Mo 2 C@NC/NrGO could be suggested as a prospective catalyst for ODS. [ABSTRACT FROM AUTHOR]

A ternary nanocomposite comprising phosphotungstic acid (PW 12), polyethyleneimine (PEI), and graphene oxide (GO), i.e., PW 12 -PEI/GO, was developed as a precursor to obtain the W 2 C/N-rGO catalyst upon in-situ carbonization. W 2 C/N-rGO was applied in the deep oxidative desulfurization (ODS) of liquid fuel, and exhibited extraordinary performance due to the ultrafine W 2 C nanoparticles (～3–5 nm) evenly dispersed on N-rGO and the electron-donating effect of N-rGO on W 2 C. 4000 ppm of DBT in model oil could be completely removed within only 10 min with a remarkably high turnover frequency (168 h−1) and the lower activation energy (30.9 kJ·mol−1). Radical experiments and density functional theory calculations indicate that the ODS reaction proceeds mainly via a HO• radical mechanism. Moreover, W 2 C/N-rGO could be recycled for 6 successive cycles with no obvious loss of performance. [Display omitted] • Ultrafine W 2 C nanoparticles was well-dispersed on N-doped graphene upon in-situ carbonization of the PW 12 -PEI/GO precursor. • W 2 C/N-rGO showed ultrafast ODS performance for fuel oil with the initial S content of 500‐6000 ppm. • DFT calculation and the radical scavenging experiments revealed a ODS mechanism of HO• radicals. • Ultrafine W 2 C nanoparticles and the electron-donating effect of N-rGO on W 2 C significantly improved ODS performances. [ABSTRACT FROM AUTHOR]

Food processing has significant simultaneous requirements of cooling, warm water and hot water. In order to reduce energy consumption and greenhouse gases emission, one type of NH 3 heat pump and two types of transcritical CO 2 heat pumps are proposed. These natural refrigerant heat pumps can supply not only cooling, but also warm water and hot water simultaneously. The characteristics and performance of the heat pumps are analyzed and simulated. Annual primary energy saving and annual operation cost saving are predicted for California, Wisconsin, New York, and Florida. Research results show that the maximum possible value of annual primary energy-saving rates using the CO 2 heat pumps ranges from 56% to 65%, and using the NH 3 heat pump is approximately 44%; the maximum possible value of annual operation cost saving rates using the CO 2 heat pumps ranges from 50% to 66%, and using the NH 3 heat pump is from 20% to 47%. [ABSTRACT FROM AUTHOR]

This study puts forward a powerful new strategy that allows highly efficient generation of the shaping transverse nondiffracting caustics that concentrate around the expected curve. First, under the condition of stationary phase approximation, as the typical example of caustic beams, the analytical formula of nondiffracting deltoid and pentagram caustics is theoretically derived. Based on the obtained analytical formula, the desired caustics of deltoid and pentagram are numerically simulated. Hence, their optical shape and the propagation characteristics of nondiffracting caustics can be investigated. Then, based on the given generating mechanism, the corresponding experimental system to experimentally explore the nondiffracting deltoid and pentagram caustics with good self‐healing properties is constructed. Compared with the previous generating methods, the proposed method has a high light energy utilization. [ABSTRACT FROM AUTHOR]

Grade, due date, priority, and demand are attributes of magnetic material products. Planners are required to seek the optimal combination of production work orders to minimize cost and improve efficiency based on these attributes. The magnetic material group furnace optimization problem is a generalization of the 1-D bin-packing problem wherein bins of varying sizes are used. Bin sizes are determined by the grade and demand of the grouped work orders. A mathematical model is established to solve the magnetic material group furnace optimization problem by using a specialized genetic algorithm (SGA). In SGA, an initial population generation method is designed by following the sort criteria of the earliest completion date. The furnace charging weight is set according to several rules derived from work order attributes. An elite strategy and an improved greedy three-crossover operator are introduced to enhance convergence speed and precision. In addition, a reverse operator is applied to exploit the proposed algorithm. Simulation results based on practical production data show that the established model is suitable and that the presented algorithm is effective. [ABSTRACT FROM PUBLISHER]

Vacuum Freeze Drying has a great impact upon the production of dehydrated food because of the superior quality of the product obtained. Whereas, due to the slow rate of vacuum freeze drying, the long operation cycle, the high energy consumption generated by the vacuum freeze drying machine at run time, the development of freeze drying food will be restricted. In order to find energy-efficient approaches and seek lower cost productions, investigation was made on the process of freeze-dried garlic slice production in the freeze-dried food factory. In this paper, through analyzing the basic principle and drying process of vacuum freeze-dried garlic slice, energy consumption of refrigerating system, heating system and vacuum pump system was studied. By asking technicians and production manager from the factory, the main processing technology was learned. In addition, according to the experiences and field investigation, the technical date of lyophilized system including compressor, evaporator, condenser, ammonia pump, drying chamber and industrial boiler was learned as well as the stable parameter during the actual production process. Based on the obtained datum, using the principle of refrigeration and appropriate date processing method, the energy consumption value was calculated and compared with other dry methods. The value of SMER (specific moisture extraction rate) is 0.32 kg/kW·h, and it costs 17.84 kW·h electric power per kilogram of products. Compared with hot-air drying system and heat pump drying system, the production process of vacuum freeze-drying system is very costly and energy intensive. In line with previous research and manufacturer's actual production situation, when the evaporation temperature increased from -35°C to -33°C, electric power of 400 kW·h was saved, and electric power of 48 kW·h was reduced by the changed pressure of drying chamber from 100 Pa to 130 Pa, meanwhile, the run time decreased from 23 h to 22 h. The results prove that energy can be saved by increasing appropriately the evaporation temperature and the pressure of drying chamber during the production of freeze-dried garlic slice. It can provide reference to practical operation. [ABSTRACT FROM AUTHOR]

[Display omitted] • W 2 C@C was prepared via annealing ZnQPc/PW 12 composites at 800 °C. • Zn could promote the formation of the pure-phase W 2 C during annealing process. • W 2 C@C was firstly used as an ODS catalyst and showed remarkable performance. • DFT calculation revealed the non-radical oxidation mechanism of thiophenics over W 2 C. Herein, the tungsten carbide (W 2 C) coated with the ultrathin carbon layer (W 2 C@C) was firstly exploited as an efficient and stable oxidative desulfurization (ODS) catalyst, which was prepared via annealing metallophthalocyanine/phosphotungstic acid composites at 800 °C under N 2 atmosphere. The Zn element in precursor markedly promoted the formation of the pure-phase W 2 C during annealing process. W 2 C@C showed a remarkable ODS performance with H 2 O 2 as oxidant under mild conditions. Dibenzothiophene (DBT) was100% removed by W 2 C@C within 40 min at 50 °C. The density functional theory (DFT) calculations combined with the radical scavenging experiments suggest that the ODS over W 2 C@C follows a non-radical mechanism that involves the facile formation of surface active oxygen species. Moreover, the W 2 C@C catalyst could be easily regenerated by solvent washing and recycled with no obvious loss of performance. Therefore, W 2 C could be firstly suggested as a promising catalyst for the ODS of liquid fuels. [ABSTRACT FROM AUTHOR]

Recent years have witnessed the impact of crowdsourcing model, social media, and pervasive computing. We believe that the more significant impact is latent in the convergence of these ideas on the mobile platform. In this paper, we introduce a mobile crowdsourcing platform that is built on top of social media. A mobile crowdsourcing application called UbiAsk is presented as one study case. UbiAsk is designed for assisting foreign visitors by involving the local crowd to answer their image-based questions at hand in a timely fashion. Existing social media platforms are used to rapidly allocate microtasks to a wide network of local residents. The resulting data are visualized using a mapping tool as well as augmented reality (AR) technology, result in a visual information pool for public use. We ran a controlled field experiment in Japan for 6 weeks with 55 participants. The results demonstrated a reliable performance on response speed and response quantity: half of the requests were answered within 10 min, 75% of requests were answered within 30 min, and on average every request had 4.2 answers. Especially in the afternoon, evening and night, nearly 88% requests were answered in average approximately 10 min, with more than 4 answers per request. In terms of participation motivation, we found the top active crowdworkers were more driven by intrinsic motivations rather than any of the extrinsic incentives (game-based incentives and social incentives) we designed. [ABSTRACT FROM AUTHOR]

Abstract: Based on an analysis of the characteristics of solar and tidal energy, an innovative, multi-effect solar distillation unit for seawater desalination utilizing solar and tidal energy has been developed. The uniqueness of the system is that without being transferred to electricity, tidal energy is utilized to supply power for water supply and drainage, and vacuum extraction instead of pumps powered by electricity. So the cost can be greatly reduced. The system is based on multi-effect evaporation–condensation processes and operates under vacuum condition, so low grade solar heat can be used with a high thermal efficiency. Hydrodynamic and thermal analysis is carried out for the water supply and drainage system driven by tidal energy. The operating mechanism of the vacuum extraction system driven by tidal energy is presented. A parametric study of the behavior of the solar desalination unit has been performed. [Copyright &y& Elsevier]

Poly (glycidyl methacrylate) (PGMA) was grafted onto the SiO 2 surface to prepare the hairy particles PGMA/SiO 2 using the "grafting from" method, and then vacant Wells-Dawson-type polyoxometalates (POMs) was covalently bonded to PGMA/SiO 2 using the silane coupling agent to prepare heterogeneous catalyst POM-PGMA/SiO 2. It is highly efficient and selective for tetrahydrothiophene (THT) oxidation. The oxidation process of THT catalyzed by POM-PGMA/SiO 2 using H 2 O 2 presented some special characters. POM-PGMA/SiO 2 showed a certain microenvironment effect of the carrier, and effectively promoted the THT oxidation. There are optimal values for both the amount of POM-PGMA/SiO 2 and the bonding amount of POM for THT oxidation, and the excessive catalyst and too high density of catalytic active sites can both decrease the catalytic activity. Alkalinity is not conducive to oxidation of THT with H 2 O 2. More attractively, POM-PGMA/SiO 2 could be well reused several times, stemming from the strong covalent bonding between the POM clusters and the polymers on SiO 2 surface. Image 1 • Hairy particles covalently supported catalysts (POM-PGMA/SiO 2) are designed and prepared. • The catalytic oxidation of THT by P 2 W 17 -PGMA/SiO 2 presented some special characters. • P 2 W 17 -PGMA/SiO 2 showed a certain microenvironment effect for the oxidation of THT. • The desulfurization rate of THT reached 100% at room temperature for a short time (60 min). • P 2 W 17 -PGMA/SiO 2 could be recycled several times with little loss of detectable catalytic activity. [ABSTRACT FROM AUTHOR]

• Based on access control technology, an enterprise integrated automation system and the application model based on workflow were designed. • The workflow engine was designed and the structure of workflow system with custom form was given. • The realization process of modern intelligent workshop integrated automation system is expounded through the hardware platform of intelligent digital factories. With the development of modern workshop towards intellectualization, it is becoming more and more difficult to model and research the workshop integrated automation system based on workflow. Based on access control technology, an enterprise integrated automation system and the application model based on workflow were designed. Meanwhile, the workflow engine was designed and the structure of workflow system with custom form was given. The realization process of modern intelligent workshop integrated automation system is expounded through the hardware platform of intelligent digital factories. A series of automation processes such as workpiece warehousing management, digital manufacturing and processing, automatic transmission, information management, etc. are included in the system which can satisfy the concept of the intelligent digital factory and show the superiority of workflow-based enterprise integrated automation system. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Abstract: The sensitivity of pressure and velocity fields to gravity was explored by computational fluid dynamics. The multiphase flow model and some dynamic boundary conditions were considered in a simulation of a stirred tank. In comparing pressure and velocity fields under normal gravity and non gravity cases, different sensitivities of these fields under various conditions were found. [Copyright &y& Elsevier]

Due to the strict personnel control measures in COVID-19 epidemic, the control system cannot be maintained and managed manually. This puts forward higher requirements for the accuracy of its fault-tolerant performance. The control system plays an increasingly important role in the rapid development of industrial production. When the sensor in the system fails, the system will become unstable. Therefore, it is necessary to accurately and quickly diagnose the faults of the system sensors and maintain the system in time. This paper takes the control system as the object to carry out the fault diagnosis and fault-tolerant control research of its sensors. A network model of wavelet neural network is proposed, and an improved genetic algorithm is used to optimize the weights and thresholds of the neural network model to avoid the deficiencies of traditional neural network algorithms. For the depth sensor of a certain system, an online fault diagnosis scheme based on RBF (Radial Basis Function) neural network and genetic algorithm optimized neural network was designed. The disturbance fault, "stuck" fault, drift fault and oscillation fault of the depth sensor are simulated. Simulation experiments show that both online fault diagnosis schemes can accurately identify sensor faults and the genetic algorithm optimized neural network is superior to RBF neural network in both recognition accuracy and training time under the influence of COVID-19. [ABSTRACT FROM AUTHOR]

• New covalent bonding methods of Dawson phosphotungstic acid (P 2 W 17) onto graphene oxide (GO). • Photocatalytic mechanism of GO/P 2 W 17 was revealed. • Covalent bonding of P 2 W 17 onto GO enhances fastness and photocatalytic activity. In this study, single lacunary Dawson type tungstophosphate (P 2 W 17) was modified with γ-(2,3-epoxypropoxy)propyltrimethoxysilane (EPO) to prepare P 2 W 17 -EPO containing epoxy groups, and graphene oxide (GO) was modified with 3-aminopropyltrimethoxysilane to prepare GO-NH 2 containing amino groups. Then, P 2 W 17 was covalently bonded onto the surface of GO through the reaction of P 2 W 17 -EPO with GO-NH 2 for the preparation of GO/P 2 W 17 composite photocatalysts, and their compositions and structures were characterized by the Fourier transform infrared spectroscopy, thermogravimetric analysis, X-Ray diffraction spectroscopy, X-ray photoelectron spectroscopy, high resolution transmission electron microscopy, electrochemical impedance spectroscopy and BET analysis. The photocatalytic activity of GO/P 2 W 17 for methylene blue (MB) was also investigated. The results show that the covalent bonding of P 2 W 17 to GO results in an increase in the specific surface area, a reduction in the charge transfer impedance, and an increase in the transfer of photoinduced electrons. GO/P 2 W 17 can effectively degrade MB in water under UV light and its photocatalytic activity is significantly higher than that of EPO-P 2 W 17 , which can be attributed to the synergetic effects of adsorption and photocatalytic degradation. GO speeds up the separation of photoexcited electron hole pairs of P 2 W 17 during photocatalytic process. Besides, GO/P 2 W 17 also has good reusability and its reuse for 6 times results in only a slight decrease in the degradation rate of MB. It is concluded that the covalent bonding of P 2 W 17 onto GO can improve the photocatalytic activity of P 2 W 17. [ABSTRACT FROM AUTHOR]

A cooperative assembly route has been developed, by which silver nanoparticles with controlled sizes are incorporated into the channels of ordered cubic mesoporous silica (KIT-6) with different pore sizes (4.3-6.4nm). The samples were characterized by XRD, TEM, FT-IR, UV-Vis and N2 physisorption. The pore wall of mesoporous silica can efficiently confine the growth of silver nanoparticles within the channels and their average sizes decreased with the pore size reduction of KIT-6. Catalytic activities of the resultant Ag/KIT-6- ( stands for hydrothermal temperature) composite for reducing harmful organic dye Rhodamine B (Rh B) by sodium borohydride (NaBH4) were investigated. All the Ag/KIT-6 composite samples show great catalytic activities, among which Ag/KIT-6-80 with higher loading and smaller size of Ag nanoparticles exhibits higher catalytic activity than those of Ag/KIT-6-60 and Ag/KIT-6-100. A cooperative assembly route has been developed, by which silver nanoparticles with controlled sizes are incorporated into the channels of ordered cubic mesoporous silica (KIT-6) with different pore sizes which can efficiently confine the growth of silver nanoparticles. For reducing organic dye Rh B by NaBH4, all the Ag/KIT-6-x (x: hydrothermal temperature) composite samples show great catalytic activities, among which Ag/KIT-6-80 with higher loading and smaller size of Ag nanoparticles exhibits higher catalytic activity than those of Ag/KIT-6-60 and Ag/KIT-6-100. [ABSTRACT FROM AUTHOR]

Highlights: [•] PVTx experimental data of (R290+R134a) at six mass fractions. [•] Gas phase equations of state. [•] Dew-point saturated vapour pressure curves. [Copyright &y& Elsevier]

Abstract: Concentrated brines are known to be very good inhibitors for gas hydrate formation, and gas hydrates can be used in the desalination of seawater under the assumption that salinity is zero in gas hydrates. However, its molecular mechanism has not been understood yet. We examined this by classical molecular dynamics simulations. The simulations results showed that a pair of Na+–Cl− ions can be included in a unit cell of the hydrates with the hydrate structure being stable. However, the equilibrium pressure was larger than that of pure hydrates. Therefore, it is concluded that gas hydrates may not be salt-free completely, i.e., 0.07wt.% salinity at least. Furthermore, Na+ ions have a smaller effect on the crystal structure deformation and the equilibrium pressure of the hydrates than Cl− ions, as 4 Na+ ions may be contained in a unit cell of the hydrates. Meanwhile, massive salt ions approach to concentrate on the surface of the hydrates. The simulation results are consistent with the available desalination experimental results utilizing gas hydrate method. [Copyright &y& Elsevier]

Abstract: K-doped Li2ZrO3 sorbents with excellent CO2 capture properties were synthesized via a citrate route. The CO2 capture–regeneration properties of these synthesized K-doped Li2ZrO3 sorbents were investigated by thermogravimetric analysis (TGA) at different temperatures and CO2 partial pressures. The synthesized K-doped Li2ZrO3 sorbents possess a better CO2 capture performance than reported Li2ZrO3-based ones, especially at low CO2 partial pressures. At 823K and a CO2 partial pressure of 0.25bar, the uptake of CO2 in the K-doped Li2ZrO3 with an optimized K:Li:Zr composition of 0.2:1.6:1 in molar ratio can reach 23wt.% within 15min. Furthermore, the sorbent displays a good stability, confirmed by CO2 capture–regeneration cycles. [Copyright &y& Elsevier]

Summary: In this article, we propose a deep Koopman model predictive control (MPC) strategy to improve the transient stability of power grids in a fully data‐driven manner. Due to the high‐dimensionality and the nonlinearity of the transient process, we use the Koopman operator to map the original nonlinear dynamics into an infinite dimensional linear system. To facilitate the control design, we first utilize the deep neural network method to efficiently train observable functions to approximate the Koopman operator so that the obtained dynamics in the high dimensional space is a linear system. We then propose an MPC strategy for the obtained high dimensional linear system. The proposed control strategy utilizes energy storage units, which inject or absorb real power at the synchronous generator buses to enhance the transient stability. Simulation studies implemented on the IEEE 9‐bus 3‐machine test system and the IEEE 39‐bus 10‐machine test system illustrate the performance of the proposed deep Koopman MPC strategy. The results demonstrate that the proposed control strategy effectively enhances the transient stability of the system even in the presence of severe faults. [ABSTRACT FROM AUTHOR]

• The mixed refrigerants (R600a + R245fa) as a new alternative R245fa refrigerant. • PVTx experimental data of (R600a + R245fa) mixtures at six mass fractions. • Virial equations of state are fitted. The gaseous PVTx properties of the mixtures of 2-methylpropane(R600a) + 1,1,1,3,3-pentafluoropropane(R245fa) are measured by the Burnett isothermal expansion method while the temperatures are 300.2 K to 335.9 K and the corresponding pressures are 144.09 kPa to 895.20 kPa. The mass fraction of R600a ranges from 0.15 to 0.40. The uncertainties of the experimental equipment are estimated as: the temperature uncertainty is ±8.1 mK, the pressure uncertainty is ±1.7 kPa, and the mass fraction uncertainty is ±0.003. The results of the experiment are rectified by the virial equation of state (EOS) and the fitting virial coefficients of the virial EOS are obtained. The pressures obtained by virial EOS agree well with the experimental pressures with the relative deviations within ±0.9 %. This study provides the meaningful information for the further studies on the Organic Rankine Cycle using these novel mixed refrigerants. [ABSTRACT FROM AUTHOR]

Crystal structures, thermoelectric and mechanical properties of p-type PbSe-SrSe system were investigated over the full composition range. A continuous solid solution was formed in the PbSe-SrSe system. Na doping was used to modulate the carrier concentration of the system. The concentrations of Sr and Na for optimum thermoelectric performance of the system were determined to be 6% and 0.8%, respectively. The figure of merit ZT at 813 K was increased from 0.58 for non-Sr containing PbSe (with 2% Na doping) to 0.8 for Na and Sr optimized PbSe-SrSe solid solution. Then, Mn was introduced into the solid solution to further optimize the thermoelectric properties. The addition of Mn could generate nanosized particle-like Mn-rich precipitates in the matrix of PbSe-SrSe alloys and substantially reduce the lattice thermal conductivities. As a result, when half of the 6% Sr was replace by Mn, the ZT at 813 K could be further raised to ∼1.03. Furthermore, the presence of the Mn-rich precipitates could effectively strengthen the mechanical properties of the PbSe-SrSe alloys, which is favorable for the future practical applications of the PbSe materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nutritional components of sports food include basic nutrients and functional factors. • Functional factors in sports foods play a very important role in regulating the physical functions of sportspeople. • Sports food market contains sports drinks, solid and semi-solid sports food. • The sports food industry has seen many opportunities and also faces some challenges. In recent years, the increase in public awareness of sports has greatly promoted the development of the sports food industry. Sports food provides nutrition to meet the metabolic and energy needs of sports people. The nutritional components of sports food can be divided into basic nutrients and functional factors. Basic nutrients refer to the nutrients or metabolites required by the human body. Functional factors are bioactive ingredients that have potential effects in improving functions of the human body, such as protection of articular cartilage and improving muscle quality. Currently, there are various forms of sports foods in the market, including sports drinks, solid sports foods, semi-solid sports foods, and sports nutrition supplements. The sports food industry has seen many opportunities such as the expanding market, manufacturing technology development, and increasing funds investment. However, it also faces many challenges, such as lack of innovation, insufficient in-depth research, risks, and safety issues. This review would provide theoretical guidance for current sports food manufacture to meet the needs of increasing sports people worldwide. [ABSTRACT FROM AUTHOR]

• Experiments are conducted to investigate the frequency spectrum characteristics. • Multiple channel mechanical signals are interpreted for mill load parameter (MLP). • A measurement method for the contribution rate of the mechanical signals is proposed. • Mechanical channels must be selected to construct an effective MLP prediction model. Online monitoring load parameters inside the ball mill is the key to improving the production quality and quantity of the mineral grinding process. In this paper, the experimental analysis of wet mill load parameter (MLPs) based on multiple channel mechanical signals is presented. A series of experiments is conducted to investigate the mechanical frequency spectrum characteristics in terms of different grinding conditions, such as only-ball, -mineral, or –water load change. Based on power spectra density (PowSD), multiple channel mechanical signals are interpreted for different MLPs, i.e., mineral-to-ball volume ratio (MBVR), pulp density (PD), and charge volume ratio (CVR), in detail. Experimental results show that the PowSDs of these mechanical signals are positively correlated with CVR and negatively correlated with MBVR and PD. Further, the generation mechanism of these mechanical signals is qualitatively analyzed, and a new measurement method for the contribution rate of multiple channel mechanical signals, i.e., combination estimation index, is proposed. The results show the different contribution rates of these signals to various MLPs under varied grinding conditions. Appropriate mechanical channels for different MLPs must be selected to construct an effective MLP forecasting model. [ABSTRACT FROM AUTHOR]