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Employing a grounded theory approach, this study conducts interviews with 30 scholars and government officials actively involved in extensive study and practical endeavors within the domains of Sport City and sports events. The inquiry aims to elucidate the factors driving the promotion of the construction of Sport City facilitated by hosting major sports events. The results indicate that major sports events demonstrate a "cumulative effect" in fostering the construction of Sport City. Influential factors encompass the function of Sport City, the economy of Sport City, the resident well-being of Sport City, and the soft power of Sport City. Furthermore, the promotional influence of hosting major sports events on one facet of Sport City positively impacts the development of other facets. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO2) nanomaterials have been widely used in photocatalytic energy conversion and environmental remediation due to their advantages of low cost, chemical stability, and relatively high photo-activity. However, applications of TiO2 have been restricted in the ultraviolet range because of the wide band gap. Broadening the light absorption of TiO2 nanomaterials is an efficient way to improve the photocatalytic activity. Thus, black TiO2 with extended light response range in the visible light and even near infrared light has been extensively exploited as efficient photocatalysts in the last decade. This review represents an attempt to conclude the recent developments in black TiO2 nanomaterials synthesized by modified treatment, which presented different structure, morphological features, reduced band gap, and enhanced solar energy harvesting efficiency. Special emphasis has been given to the newly developed synthetic methods, porous black TiO2, and the approaches for further improving the photocatalytic activity of black TiO2. Various black TiO2, doped black TiO2, metal-loaded black TiO2 and black TiO2 heterojunction photocatalysts, and their photocatalytic applications and mechanisms in the field of energy and environment are summarized in this review, to provide useful insights and new ideas in the related field. [ABSTRACT FROM AUTHOR]

A phase-field model was revised to study the abnormal growth of Goss grains during the annealing process in Fe-3%Si steels, in which the interaction between the second-phase particles and Goss grain boundaries (GBs) was considered. The results indicate that the abnormal growth of Goss grains occurs due to the different dissolvability of the particles at Goss GBs compared with the other GBs. Moreover, the degree of abnormal growth increases first and then decreases with an increasing particle content. Meanwhile, the size advantage of Goss grain can further promote the degree of abnormal growth. Two types of island grains were found according to the simulated results, which is consistent with the experimental observations. A proper GB dissolvability of particles is the key factor for the formation of isolated island grains, and a higher local particle density at GBs is the main reason for the appearance of serial island grains. These findings can provide guidance for the desired texture control in silicon steels. [ABSTRACT FROM AUTHOR]

[Display omitted] • TiO 2 /defective UiO-66 porous octahedral S-scheme heterojunctions are constructed. • The strong interaction and charge migration behavior between TiO 2 and defective UiO-66 have been studied. • S-scheme heterostructures accelerated charge separation and transfer efficiency. • Superoxide radicals were the dominant oxidizing agents for photocatalytic tetracycline removal. Photocatalysis is an alternative for antibiotics removal from wastewater for the sustainable development of human society. However, applying photocatalysts for antibiotics (e.g., tetracycline) degradation under practical conditions is highly restricted by the low reaction efficiency due to the prompt charge recombination. Constructing porous heterojunctions is an efficient way to regulate the electron transfer path and accelerate charge migration efficiency. Herein, TiO 2 /defective UiO-66 porous octahedral S-scheme heterojunctions are successfully fabricated through an in-situ growth strategy. The strong interaction and charge migration behavior between TiO 2 and defective UiO-66 have been studied using X-ray photoelectron spectroscopy and electron paramagnetic resonance measurements. The photocatalytic removal efficiency of tetracycline is notably improved by forming TiO 2 /defective UiO-66 porous heterojunctions. The promoted photocatalytic performance can be ascribed to the strong interaction between TiO 2 and defective UiO-66, and the accelerated charge separation and transfer efficiency due to the formation of S-scheme heterojunctions, thus generating abundant reactive oxygen species, including O 2 − and OH. The optimized 38-TiO 2 /UiO-66-300 can eliminate 97.9 % of tetracycline in 60 min with a reaction constant rate of 0.0425 min−1, which is approximately 4 and 10 times that of pristine TiO 2 and UiO-66-300, respectively. This work provides an alternate strategy for preparing highly active heterojunction photocatalysts for environmental applications. [ABSTRACT FROM AUTHOR]

We proposed a dual-ejector-based regenerative dual–pressure organic flash cycle (DEj–RDPOFC) with higher performance than the RDPOFC. The effects of high and low pressures and the entrainment ratio of the ejector on the DEj–RDPOFC performance were analyzed from the viewpoints of thermodynamics and thermoeconomics. An exergy-flow distribution diagram revealed why the DEj–RDPOFC outperformed the RDPOFC. Next, the performances of the DEj–RDPOFC and dual–pressure organic Rankine cycle (DORC) were compared under the same boundary conditions. Finally, the performance of the DEj–RDPOFC was optimized using the nondominated sorting genetic algorithm (NSGA-II). According to the results, the power output of the high-pressure (HP) turbine of the DEj–RDPOFC can be increased by replacing the HP throttling valve (TV) with an ejector (which increases the working fluid dryness of the HP vapor separator and the mass flow rate of the HP turbine) and the low-pressure (LP) TV with an ejector (which increases the HP turbine expansion ratio). The DEj–RDPOFC achieves a higher maximum net power output (W net) and a lower corresponding levelized cost of electricity (LCOE) than the DORC. Under the optimum condition, the W net and LCOE of the DEj–RDPOFC are 9.71 % higher and 6.59 % lower, respectively, than those of the RDPOFC. • The effect of the HP and LP ejector on the performance of the regenerative DPOFC (RDPOFC) are analyzed. • The performance of the RDPOFC assisted by ejectors (DEj–RDPOFC) is compared with the dual-pressure ORC. • The DEj–RDPOFC is optimized using a multi-objective optimization algorithms. [ABSTRACT FROM AUTHOR]

Highlights • The thermodynamic and thermo-economic models of SORC and DORC are built. • The thermodynamic and thermo-economic performances are optimized and compared. • The DORC can increase power output and show better thermo-economic performance. Abstract The goal of this paper is to study and evaluate the thermodynamic and the thermo-economic performance of dual-pressure and single pressure evaporation organic Rankine cycle (DORC and SORC) using isobutane as the working fluid. The effects of the two-stage pressures and the heat source inlet temperature on the system performances have been investigated. Then the performance comparisons between SORC and DORC have been conducted at the optimized condition. Results show that the DORC yields more net power than the SORC when the heat source temperature is between 100 and 177.2 °C, and the net power output gains of the DORC are higher at lower heat source temperature. The DORC no longer has the performance advantage as the heat source temperature is above 177.2 °C. The thermo-economic evaluations show that the optimized electricity production cost (EPC) decreases as the heat source temperature rises. Furthermore, optimized EPC of SORC and DORC are nearly equal at the same heat source temperature. For the heat source temperature of 100–177.2 °C, the DORC can significantly increase the net power output, but the thermo-economic performance of DORC is not reduced by system complexity compared to the SORC. [ABSTRACT FROM AUTHOR]

Highlights • An engine speed control model is established and identified by step experiments. • A gas engine speed control strategy is proposed and applied to control the engine speed of GEHPs. • The engine speed controller has a good performance in terms of settling time and overshoot. ABSTRACT The gas engine-driven heat pump (GEHP) system is an energy saving device for heating, cooling or hot water supply. As the power source of the system, the performance of gas engine speed control directly has a significant impact on the system stability and efficient operation. However, gas engine is typically a nonlinear dynamical system and easily disturbed by the load fluctuation, which increases the difficulty of control of gas engine speed. Therefore, a gas engine speed control strategy is proposed for a GEHP system. Aiming at achieving this objective, a test facility is developed and an engine speed controller is designed according to the characteristics of the gas engine and the GEHP system. Then the engine speed controller is applied to the GEHP system and experiments are performed under different conditions: engine speed setting control and anti-disturbance control. The experimental results show that it costs less than 40 s to make the engine speed steady without overshoot when engine speed setting changes. When the disturbances of superheat change occur, the error (accuracy) of the engine speed is controlled within ± 50 rpm. The engine speed control strategy can not only guarantee the stable operation but also satisfy the capacity adjustment performance of the GEHP system. Finally, performance characteristics of the GEHP are characterized by heating capacity and primary energy ratio (PER). The results indicate that engine speed is an important factor which influences the performance of the GEHP. The heating capacity increases with the increase of engine rotational speed, while PER of the GEHP decreases. In terms of energy saving, the GEHP system should operate at lower engine speed in the case of satisfying the system load. [ABSTRACT FROM AUTHOR]

[Display omitted] • The dynamic tensile failure of bamboo was investigated by the split Hopkinson tensile bar (SHTB) tests. • The significant failure mechanisms of brittle-ductile transition of bamboo was revealed. • The damage model of bamboo varies with strain rates was proposed. Bamboo is a fast-growing biomaterial with excellent mechanical properties, which can be used for different applications, such as bridges and automobiles. This study employed the split Hopkinson tensile bar (SHTB) tests with the strain rate changed from 600 s−1 to 1200 s−1 and quasi-static tensile tests to investigate the dynamic tensile failure of Moso bamboo material systematically. Specimens' mechanical properties, stress–strain responses, and tensile failure mechanism were discussed. Results showed that the tensile performance of both internode and node specimens improved with increasing strain rate. The dynamic increase factor (DIF) of node specimens was more significant than that of internode specimens. The fibers pulling out, interlocking effect and slippage failure are important failure mechanisms of brittle-ductile transition. The crack deflection, fibers pulling out, interlocking effect, synergistic deformation and slippage can be considered critical toughening mechanisms. This study fills the knowledge gaps between strain rate and dynamic tensile fracture mechanisms of bamboo material and provides a reference for dynamic engineering applications of bamboo. [ABSTRACT FROM AUTHOR]

We use a phase field model to simulate the competitive precipitation of the Mg 2 Sn phase along different habit crystal planes of the parent α-Mg phase in real time and industrial scale space at an aging temperature of 450 K as a function of time. An expression of the local free energy density was established as a function of the concentration of the α-Mg matrix simplified by main alloy element Sn only and of the order parameters of different phases for the Mg-2.2Sn-0.1Zn alloy during the aging process. Furthermore, a numerical phase transformation tensor method was cautiously introduced for Mg 2 Sn precipitation based on theoretical transformation atom displacement analysis. The simulations eventually can meet the experimental microstructure observation successfully. It is suggested that random distribution of dissolved Sn atoms in the α-Mg promotes favorite formation of pyramidal Mg 2 Sn precipitates. [ABSTRACT FROM AUTHOR]

Effect of bisulfite (HSO 3 -) on the stress corrosion cracking (SCC) behavior of 7050-T7451 aluminum alloy in the thin electrolyte layer environment in the presence of Cl- is investigated. Addition of HSO 3 - inhibits the corrosion initiation but promotes the corrosion propagation and hydrogen uptake. With a quantitative calculation, the HSO 3 - is demonstrated to significantly facilitate the synergistic effect between stress, corrosion, and hydrogen during the in-situ tensile test, resulting in the change of the SCC controlling step from corrosion-induced hydrogen to mechanical-electrochemical-hydrogen interactions. The buffer effect of HSO 3 - plays a dominant role in the HSO 3 --induced acceleration of the SCC degradation. • Effect of HSO 3 - on the SCC behavior of 7050 alloy in TEL environment containing Cl- is studied. • HSO 3 - inhibits corrosion initiation but promotes corrosion propagation and hydrogen uptake. • Addition of HSO 3 - changes the SCC controlling step of 7050 alloy in TEL environment. • The buffer effect of the HSO 3 - dominates the HSO 3 --accelerated SCC deterioration. [ABSTRACT FROM AUTHOR]

• Quasi-static and dynamic compressive behavior of bamboo scrimber is investigated. • Dynamic increase factor describing strain rate effect is provided. • Phenomenological constitutive models are summarized. • Size and shape effect and mechanical properties in three loading directions are summarized. Bamboo scrimber (BS), a renewable fiber-reinforced composite, is considered an ideal alternative to traditional construction materials. To investigate the compressive mechanical response of BS at different strain rates, experiments were conducted in three directions (directions X , Y , and Z) under quasi-static and dynamic loads. Results indicate that the mechanical properties in direction X are better than the other two. The failure modes in direction X include bulking, shearing and debonding, while shearing and crushing modes occur in directions Y and Z , respectively. Four compression phenomenological constitutive models are summarized via the stress–strain relationship. The strain rate effect represented by a DIF model and the micro-mechanism can be interpreted as micro-inertia and local densification. Compressive strength and Young's modulus also can be influenced by the size and shape effect. [ABSTRACT FROM AUTHOR]

[Display omitted] • N 2 O formation is 100% inhibited in photocatalytic NO x reduction with carbon. • NO x and carbon particles are converted into N 2 and CO 2 , respectively. • Z-scheme heterojunction enhanced charge transfer and photocatalytic reaction rate. • N 2 O is inhibited due to rapid charge separation and N 2 O adsorption on TiO 2 surface. The chemically inert property of nitrous oxide (N 2 O) has made it difficult to be reduced to benign dinitrogen during (photo) selective catalytic reduction (SCR) of NO x. The introduction of oxygen vacancies and BrØnsted acid sites to thermal catalysts is found to effectively inhibit N 2 O formation. However, the efficiency is still far from satisfactory and the inhibition of N 2 O in photocatalytic selective reduction of NO x has not been investigated yet. Herein, 100% inhibition of N 2 O formation during photo-SCR of NO x with carbon particles is successfully achieved via the fabrication of Bi 2 WO 6 /TiO 2 Z-scheme heterojunction photocatalyst. The completely inhibited N 2 O formation is attributed to the rapid charge separation and stronger N 2 O adsorption on the (101) plane of TiO 2 according to the density functional theory calculations and experimental results. The presence of water vapor prolongs the reaction time for NO x photo-reduction of carbon particles but has no significant effect on carbon oxidation rate. Introduction of heterostructure interface effectively accelerates photo-induced charge carrier separation and transfer, thereby enhancing photocatalytic efficiency for NO x reduction with carbon particles. The optimized 0.2 Bi 2 WO 6 /TiO 2 (molar ratio) composite achieves the highest formal electron/photon quantum efficiency of 0.036, which is 3.3 times that of TiO 2. The results provide an alternative perspective on the catalyst fabrication via the simple heterojunction materials for toxic byproduct control in the field of pollutants removal. [ABSTRACT FROM AUTHOR]

An efficient transcritical CO 2 combined cooling, heating and power (CCHP) systems, in which the ejector refrigeration cycle is integrated with power cycle (ER-CCHP), is proposed and analyzed for recovering low-grade energy. The proposed ER-CCHP system is compared to the TR-CCHP system, in which the throttle refrigeration cycle is integrated with power cycle. To evaluate the performance of the two systems, thermodynamic models are built and the effects of turbine parameters and evaporation temperature on the performance of the systems are investigated from the aspects of energy and exergy. The results indicated that the ER- CCHP system can provide more power than the TR- CCHP system due to the introduction the ejector. Furthermore, parametric optimizations are also performed for achieving the maximum net power output. And the maximum power output and the corresponding exergy efficiencies of the ER-CCHP and TR-CCHP systems under different the heat source temperatures are calculated, respectively. It is found that under the heat source of 230 °C the ER-CCHP and TR-CCHP systems could produce the maximum net power output of 7537.5 and 7910.3 kW, respectively. However, it should be noted that the above results are obtained under design conditions, and the off-design performance is not considered. • The performance of TR-CCHP and ER-CCHP systems using CO 2 are investigated. • The effects of turbine parameters and evaporation temperature are studied. • The systems are optimized to produce the maximum net power. [ABSTRACT FROM AUTHOR]

Bearingless induction motors, which were multivariable, were strongly coupled, along with a higher order nonlinear system. To obtain the stable suspension control of a bearingless induction motor, a new control strategy based on Adaptive Neuro Fuzzy Inference System was proposed. First, in the analysis of the generation mechanism of a bearingless induction motor's radial suspension force, the mathematical model of a bearingless induction motor was achieved. Based on the control principle of an Adaptive Neuro Fuzzy Inference System, the Adaptive Neuro Fuzzy Inference System had been built to design the controller, including the option of control variables and membership functions. By the PID control, the input data and output data could be collected. The selected criterion of error was set to correct the membership function parameters. In addition, the Fuzzy Inference System (FIS) model was trained by a Sugeno type Adaptive Neuro Fuzzy Inference System controller. Then, aiming at the performances of rotor suspending, speed, and torque response, the simulation and analysis of the control system for bearingless induction motors had been carried out on the basis of MATLAB/Simulink simulation platform. Moreover, the motor speed was set to 6000r/min. The simulation results showed that the stable suspension of a bearingless induction motor can be quickly achieved by this presented control strategy. Through the comparison with PID control, the speed response was faster, and the speed overshoot was smaller in the Adaptive Neuro Fuzzy Inference System control. Further, the suspension performance of the rotor was not affected by the sudden change in the load torque. When the rotor speed suddenly changed from 6000r/min to 3000r/min at the time of 0.5 seconds, the speed response of the control system could track the given speed well, and with a very small steady state error. The control system has a fine dynamic and static performance. Finally, the control system test platform of a bearingless induction motor was built based on Adaptive Neuro Fuzzy Inference System controller. The experimental results of the control system also showed that this control strategy could achieve the stable suspension of a bearingless induction motor. The control system has a quickly response, a high control precision, and the strong robustness to load torque disturbance. The correctness and effectiveness of the Adaptive Neuro Fuzzy Inference System control method was verified in this paper. [ABSTRACT FROM AUTHOR]

Highlights: [•] We formulate engine speed control process. [•] We construct expert controller for engine rotary speed control. [•] Simulation results show expert controller has good response and robustness. [•] The experimental data verify the simulation results well. [ABSTRACT FROM AUTHOR]

Background: Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) have been reported to play regulatory roles in ulcerative colitis (UC). In this study, we aimed to determine the specific roles and action mechanism of the nuclear paraspeckle assembly transcript 1 (NEAT1) in UC. Methods: Reverse transcription‐quantitative polymerase chain reaction (RT‐qPCR) was used to determine the lncRNA NEAT1 and miR‐493‐5p expression levels in patients with UC and healthy volunteers. We determine the forecast linkage points of NEAT1 and miR‐493‐5p using Starbase and those of miR‐493‐5p and Rab27A using TargetScan, and further verified them using a double luciferase gene reporter kit. RT‐qPCR and Western blot analysis were used to determine the lncRNA NEAT1, miR‐493‐5p, and Rab27A expression levels in lipopolysaccharide (LPS)‐induced Caco‐2 cells. Flow cytometry and cell counting kit‐8 were used to assess Caco‐2 cell viability. Tumor necrosis factor‐α, interleukin (IL)‐6, IL‐8, and IL‐1β levels were determined via an enzyme‐linked immunosorbent assay. Results: Expression levels of NEAT1 were upregulated and those of miR‐493‐5p were downregualted in 10 ng/mL LPS‐treated Caco‐2 cells and patients with UC. Dual‐luciferase gene reporter assay revealed that miR‐493‐5p is linked to NEAT1, and Rab27A is a downstream target of miR‐493‐5p. Overexpression of miR‐493‐5p inhibited the apoptosis and inflammation in LPS‐treated Caco‐2 cells. Moreover, downregulation of lncRNA NEAT1 expression also inhibited the apoptosis and inflammation in LPS‐treated Caco‐2 cells, which was reversed by Rab27A plasmid cotransfection. Conclusion: Our results revealed that NEAT1 participates in UC progression by inhibiting miR‐493‐5p expression. [ABSTRACT FROM AUTHOR]

Abstract: Spatial, quantitative, and temporal information regarding the water content distribution in the transverse-plane between the catalyst layers of an operating polymer-electrolyte membrane fuel cell (PEMFC) is essential to develop a fundamental understanding of water dynamics in these systems. We report 1H micro-magnetic resonance imaging (MRI) experiments that measure the number of water molecules per SO3H group, λ, within a Nafion®-117 membrane between the catalyst stamps of a membrane-electrode assembly, MEA. The measurements were made both ex situ, and inside a PEMFC operating on hydrogen and oxygen. The observed 1H MRI T 2 relaxation time of water in the PEM was measured for several known values of λ. The signal intensity of the images was then corrected for T 2 weighting to yield proton density-weighted images, thereby establishing a calibration curve that correlates the 1H MRI density-weighted signal with λ. Subsequently, the calibration curve was used with proton density weighted (i.e., T 2-corrected) signal intensities of transverse-plane 1H MRI images of water in the PEM between the catalyst stamps of an operating PEMFC to determine λ under various operational conditions. For example, the steady state, transverse-plane λ was 9±1 for a PEMFC operating at ∼26.4mWcm−2 (∼20.0mA, ∼0.661V, 20°C, flow rates of the dry H2(g) and O2(g) were 5.0 and 2.5mLmin−1, respectively). [Copyright &y& Elsevier]

Abstract: In order to accomplish the quantitative simulation of the realistic spatio-temporal microstructure evolution during recrystallization in the industrial application scale of micrometers and minutes, a model has been established using the phase field method (PFM). All the physical values of the parameters in the model have been determined by establishing a set of rules, some of which are proposed in first time. The simulated results have a good agreement with the experimental observations of the AZ31Mg alloy during recrystallization between temperatures 300–400°C for up to 100min. The simulation implies a mechanism variation in the activity energy of grain boundary mobility at low temperatures such as at 250°C for the alloy. Analysis of the simulated microstructures reveals that the grain size fluctuation increases with increasing recrystallization temperature and annealing time. It is found that the grain size fluctuation becomes particularly severe when the recrystallization temperature is over a critical value of 350°C, which agrees well with the existing experimental data in the AZ31Mg alloy. [Copyright &y& Elsevier]

Paeoniflorin (PF) is one of the active constituents of the traditional Chinese medicine Paeoniae Radix Rubra and has been actively explored in the pharmaceutical area due to its numerous pharmacological effects. However, severe difficulties such as limited bioavailability and low permeability limit its utilization. Therefore, this study developed and synthesized 25 derivatives of PF, characterized them by 1H NMR, 13C NMR, and HR‐MS, and evaluated their antioxidant activity. Firstly, the antioxidant capacity of PF derivatives was investigated through DPPH radical scavenging experiment, ABTS radical scavenging experiment, reducing ability experiment, and O2.− radical scavenging experiment. PC12 cells are routinely used to evaluate the antioxidant activity of medicines, therefore we utilize it to establish a cellular model of oxidative stress. Among all derivatives, compound 22 demonstrates high DPPH radical scavenging capacity, ABTS radical scavenging ability, reduction ability, and O2.− radical scavenging ability. The results of cell tests reveal that compound 22 has a non‐toxic effect on PC12 cells and a protective effect on H2O2‐induced oxidative stress models. This might be due to the introduction of 2, 5‐difluorobenzene sulfonate group in PF, which helps in scavenging free radicals under oxidative stress. Western blot and molecular docking indicated that compound 22 may exert antioxidant activity by activating Nrf2 protein expression. As noted in the study, compound 22 has the potential to be a novel antioxidant. [ABSTRACT FROM AUTHOR]

Ceramic-particle-reinforced iron matrix composites (CPR-IMCs) have been used in many fields due to their excellent performance. In this study, using the fast resistance-sintering technology developed by our team, iron matrix composites (IMCs) reinforced by both SiC and TiCx particles were fabricated via the addition of SiC and Ti3AlC2 particles, and the resulting relative densities of the sintering products were up to 98%. The XRD and EDS analyses confirmed the in situ formation of the TiCx from the decomposition of Ti3AlC2 during sintering. A significant hybrid reinforcing effect was discovered in the (SiC + TiCx)p/Fe composites, where the experimental strength and hardness of the (SiC + TiCx)p/Fe composites were higher than the composites of monolithic SiCp/Fe and (TiCx)p/Fe. While, under the condition of constant particle content, the elongation of the samples reinforced using TiCx was the best, those reinforced by SiC was the lowest, and those reinforced by (SiC + TiCx) fell in between, which means the plastic response of (SiC + TiCx)p/Fe composites obeyed the rule of mixture. The successful preparation of IMCs based on the hybrid reinforcement mechanism provides an idea for the optimization of IMCs. [ABSTRACT FROM AUTHOR]

Thermodynamic properties of working fluids have significant effects on the system performance of the transcritical organic Rankine cycle, and the optimal working fluid is related to the heat source temperature. In this paper, both separate and combined effects of the critical temperature (T cri), critical pressure (P cri) and dryness (ξ) of working fluids on the performance of TORCs were investigated under different heat source temperatures. The trends in variation of maximum net power output (W max) based on the increase of the critical temperatures of working fluids were also investigated. The results indicated that a lower T cri of working fluids would lead to an increase in the expander's outlet temperature and a worse thermal match in the condenser. However, a higher T cri would result an increase in the heat source outlet temperature and a worse thermal match in the vapor generator. In addition, a higher P cri would lead to an uneven temperature curve for the working fluid and a worse thermal match in the vapor generator. A larger ξ would result in high superheat at the condensation pressure and a worse thermal match in the condenser. Working fluids with suitable T cri , lower P cri and lower ξ could achieve better net power output performance. • The lower and higher critical temperature lead to worse thermal match in the vapor generator. • The higher critical pressure results in the uneven temperature curve in the vapor generator. • The larger dryness of working fluid leads to the higher superheat degree in the condenser. [ABSTRACT FROM AUTHOR]

• Performance of DORC and TORC are analyzed from the thermal match. • The suitable heat source temperature ranges of DORC and TORC are different. • There is a boundary heat source temperature for the selection of DORC or TORC. • The boundary temperature of R227ea, R1234ze(E), Isobutane and R245fa are given respectively. Dual-pressure and transcritical Organic Rankine Cycles (DORC and TORC) all have advantages of increasing the thermal match between the working fluid and heat source. However, their temperature ranges of applicable heat source are different. This study focuses on the investigation and comparison of subcritical ORC (SORC), TORC and DORC using various working fluids for recovering energy of hot water which temperature is between 120 °C and 200 °C. Effects of evaporation pressure of SORC, two-stages pressures of DORC, and turbine inlet parameters (temperature and pressure) of TORC on the thermal match and the net power output have been studied. Then the thermal match and net power output comparisons of SORC, DORC and TORC under the optimal conditions for various temperatures of heat source (120–200 °C) have been presented. Furthermore, the maximum net powers of threes cycles using various working fluids are also optimized and compared when the heat source temperatures are given. The results indicate that for the DORC system, the thermal match improves as high stage pressure rises. And compared with the low stage pressure, the high stage pressure has a greater effect on the system performance. For the TORC system, the slop of temperature rising curve of supercritical working fluid is affected by the factors such as heat source inlet temperature, turbine inlet temperature and turbine inlet pressure of turbine. And it influences the thermal match in the vapor generator. There is a boundary temperature of heat source for the selection of DORC and TORC using various working fluids. If heat source temperature is less than the boundary temperature, DORC shows better system performance, otherwise, TORC possesses better performance. The boundary temperatures of R1234ze(E), R227ea, Isobutane, R245fa are 151.4 °C, 125.5 °C, 170.8 °C and 195.8 °C respectively. And the analyzed results also present that there exists suitable cycle layout and appropriate working fluid to achieve best thermal match and produce maximum net power when the heat source temperature is given. [ABSTRACT FROM AUTHOR]

Purpose: The sport-event theme songs is a crucial means to evoke consumer enthusiasm and boost the influence of sport event. This research aims to examine the effects of direct and indirect listening channels for sport-event theme songs on consumers' willingness to share. Methods: In this research, three between-subjects experiments were conducted to measure the effect of listening channels for sport-event theme songs on the willingness to share, along with the moderating effects of fans' fanaticism and sport-event type. All participants in the experiments were social populations from China. Results: Study 1 reveals that direct listening is more likely to cause consumers to share cognitive information about sport-event theme songs; indirect listening, meanwhile, makes them more willing to share the emotional value of the songs. Study 2 indicates that fans' fanaticism moderates the relationship between listening type and shared content. In the case of low fanaticism, indirect listening can increase consumers' willingness to share sport-event theme songs compared with direct listening. Study 3 reveals that sport-event type moderates the relationship between listening type and shared content. For public welfare sport events, indirect listening is more likely than direct listening to cause consumers to share the emotional value of sport-event theme songs. For commercial events, compared with indirect listening, direct listening is more likely to cause consumers to share cognitive information about sport-event theme songs. Conclusion: The results of this research unveiled the effect of listening channels for sport-event theme songs on the willingness to share, as well as the theoretical mechanisms behind them. In addition, this research enriches the research on listening channels in the field of psychology and provides an important basis for improving the effectiveness of sport-event theme songs. [ABSTRACT FROM AUTHOR]

Based on the principle of grain refinement caused by the second-phase particles, a phase field model was built to describe the recrystallization process in the ZK60 alloy system with Y added under applied stress between temperatures 573 and 673 K for 140 min duration. The simulation of grain growth with second phase particles and applied stress during annealing process on industrial scale on the condition of real time-space was achieved. Quantitative analysis was carried out and some useful laws were revealed in ZK60 alloy system. The second phase particles had a promoting effect on the grain refinement, however the effect weakened significantly when the content exceeded 1.5%. Our simulation results reveal the existence of a critical range of second phase particle size of 0.3–0.4 μm, within which a microstructure of fine grains can be obtained. Applied stress increased the grain coarsening rate significantly when the stress was more than 135 MPa. The critical size of the second phase particles was 0.4–0.75 μm when the applied stress was 135 MPa. Finally, a microstructure with a grain size of 11.8–13.8 μm on average could be obtained when the second phase particles had a content of 1.5% and a size of 0.4–0.75 μm with an applied stress less than 135 Mpa after 30 min annealing at 573 K. [ABSTRACT FROM AUTHOR]

In this study, the phase field method has been used to study the effect of second phase particles with different shapes and different orientations on the grain growth of AZ31 magnesium alloy, after annealing at 350 °C for 100 min. The results show that the shape of the second phase particles would have an effect on the grain growth; the refinement effect of elliptical particles and rod-shaped particles was similar, and better than the spherical particles; the spatial arrangement direction of the second phase particles had no significant effect on the grain growth. On the other hand, when the microstructure of AZ31 magnesium alloy contained second phase particles with different shapes, the effect of mixing different shapes of second phase particles on the grain refinement was enhanced gradually with the decrease im the volume fraction of spherical particles. [ABSTRACT FROM AUTHOR]

In the past decade, bamboo scrimber has developed rapidly in the field of building materials due to its excellent mechanical properties, such as high toughness and high tensile strength. However, when the applied stress exceeds the ultimate strength limit of bamboo scrimber, cracks occur, which affects the performance of bamboo scrimber in structural applications. Due to the propensity of cracks to propagate, it reduces the load-bearing capacity of the bamboo scrimber material. Therefore, research on the fracture toughness of bamboo scrimber contributes to determining the material's load-bearing capacity and failure mechanisms, enabling its widespread application in engineering failure analysis. The fracture toughness of bamboo scrimber was studied via the single-edge notched beam (SENB) experiment and compact compression (CC) method. Nine groups of longitudinal and transverse samples were selected for experimental investigation. The fracture toughness of longitudinal bamboo scrimber under tensile and compressive loadings was 3.59 MPa·m1/2 and 2.39 MPa·m1/2, respectively. In addition, the fracture toughness of transverse bamboo scrimber under tensile and compressive conditions was 0.38 MPa·m1/2 and 1.79 MPa·m1/2, respectively. The results show that, for this material, there was a significant distinction between longitudinal and transverse. Subsequently, three-point bending tests and simulations were studied. The results show that the failure mode and the force–displacement curve of the numerical simulation were highly consistent compared with the experimental results. It could verify the correctness of the test parameters. Finally, the flexural strength of bamboo scrimber was calculated to be as high as 143.16 MPa. This paper provides data accumulation for the numerical simulation of bamboo scrimber, which can further promote the development of bamboo scrimber parameters in all aspects of the application. [ABSTRACT FROM AUTHOR]

In this study, a direct expansion heat pump assisted solar drying system was proposed and applied for drying Lentinus edodes. The operation modes of this system were divided into three types according to the purpose of reducing drying energy consumption. Under different environment conditions, the operation performance of direct expansion heat pump assisted solar drying system was investigated. In addition, the system was compared with open solar drying to analyze the drying characteristics of Lentinus edodes. The results showed that the direct expansion heat pump assisted solar drying system under solar collector drying operation mode could increase the outdoor air temperature by 9.8 °C, and the air temperature of the drying chamber could be maintained above 40 °C. The average performance coefficient of the direct expansion heat pump continuous drying was 2.56, and the duration of the drying chamber temperature above 40 °C was 63.8% of the total drying time. The average performance coefficient of the direct expansion heat pump assisted solar energy intermittent drying can reach a maximum value of 6.01. High compressor operating frequency and solar radiation intensity are the main factors affecting the coefficient of performance improvement of the direct expansion heat pump assisted solar drying system. Furthermore, the moisture content of Lentinus edodes under open sun drying was 0.274 g water/g dry matter higher than that under direct expansion heat pump assisted solar drying system. The Page model with R 2 value of 0.996 and RMSE value of 0.0211 was considered the best drying kinetics model for direct expansion heat pump assisted solar drying for Lentinus edodes. [ABSTRACT FROM AUTHOR]

Developing photocatalytic technologies for pollutants removal with high harmless product selectivity is a significant challenge. Construction and optimization of nanocomposites junction with appropriate band alignments is an effective method for achieving this objective. Herein, a unique popcorn-stick-like NH 2 -UiO-66/TiO 2 nanotube nanocomposites with staggered band alignment is fabricated. The small metal organic frameworks (MOFs) particles with diameters around 20 nm are uniformly dispersed on the surface of TiO 2 nanoplates, creating a popcorn-stick-like structure. The resulting as-synthesized nanocomposites photocatalysts show distinguished photocatalytic activity for simultaneous removal of carbon particles and nitrogen dioxide with 100% NO 2 conversion and 99% N 2 selectivity, about 3.9 times higher than that of pristine TiO 2. The significant enhancement is attributed to the rapid charge separation and transfer in TiO 2 and NH 2 -UiO-66 interface and the visible light absorption. The enhanced charge transfer follows double charge transfer mechanism, which is confirmed by surface photovoltage spectroscopy, photoluminescence, transient photocurrent measurements, and electrochemical impedance spectroscopy. This study demonstrates the potential for the simultaneously removal of two pollutants using the composite of TiO 2 and MOF materials with high surface area and visible light absorption ability, thereby providing the possible applications of NH 2 -UiO-66/TiO 2 composites in environmental remediation including air purification and wastewater treatment. • Unique popcorn-stick-like NH 2 -UiO-66/TiO 2 nanocomposites are constructed. • Improved light absorption and charge separation are confirmed by various techniques. • Photocatalytic carbon oxidation rate with NO 2 of the composites is about 3.9 times that of pristine TiO 2. • Charge transfer of NH 2 -UiO-66/TiO 2 heterojunctions proceeds via double charge transfer mechanism. [ABSTRACT FROM AUTHOR]

Abstract A novel energy system which serves public buildings with large interior zones was proposed in this study. The proposed system integrates a modified water loop heat pump (WLHP) with a natural-gas-fueled SOFC plant. The distributed SOFC plant is employed to complete the conversion from chemical energy to electricity and heat, and the modified WLHP which retrieves the waste heat of the SOFC plant is used for space cooling or heating. A "standards-oriented" model was built, and an "as-designed" approach was adopted to estimate the performance of the WLHP. For understanding the energy saving potential and CO 2 emission reduction of the proposed system, a reference system, representative of the general level of energy production and consumption, is brought about for comparison. The IEER (integrated energy efficiency ratio) and CO 2 emission trend show that the proposed system offers a much higher primary energy efficiency and realizes an obvious CO 2 emission reduction compared to the reference system. Although the estimate of the IEER and CO 2 emission reduction is conservative for some imperfections of the built models, the results of this study will still help significantly in guiding China's future CO 2 emission reduction efforts. Highlights • A modified WLHP was presented with an increased COP and a wider applicability. • A novel energy system integrated the modified WLHP with an SOFC plant was proposed. • An "as-designed" approach based on a "standards-oriented" model was adopted. • The IEER was defined to perform the evaluation of the primary energy efficiency. • Performance of the proposed system was studied by comparison with a reference system. [ABSTRACT FROM AUTHOR]

The sCO 2 Brayton cycle is considered an alternative to the conventional Brayton and Rankine cycles. The recompression Brayton cycle is advantageous because of its simple cycle layout and high cycle efficiency. The split ratio (SR) is defined as the recompression fraction of the working fluid that significantly affects the corresponding parameters of the system, particularly the cycle efficiency. However, studies focusing on the influence of SR on the design and off-design performance remain limited. The factors influencing the optimal SR and regulation mechanism under the design and off-design conditions of recompression cycle are considered in this study. The results demonstrate that the optimal SR under the design conditions is primarily affected by the high pressure, low pressure and efficiency of the recuperators. The optimal SR decreases with a reduction in the load demand, and the recompression loop can be cut off under a low load to improve the cycle efficiency. A simplified control can be achieved by controlling the temperature difference at the flow merge point to achieve a higher system efficiency. Moreover, the SR regulation mechanism is unaffected by the load control method. These findings are of significance to recompression configuration with different design parameters. • A kW-scale dynamic model of sCO 2 Brayton cycle is established and the components are validated against experiment data. • The optimization of split ratio and its simplified control method are proposed to improve the cycle efficiency. • The variation law of optimal split ratio under off-design condition is revealed. [ABSTRACT FROM AUTHOR]

A novel hybrid power generation system integrating biomass gasification, solid oxide fuel cells (SOFC), gas expanders (GE) and the Kalina cycle (KC) was proposed for analysis. The hybrid system with CO 2 capture represents an efficient and sustainable alternative to conventional distributed power plants. A clean gaseous fuel from a mature and commercialized biomass gasifier was fed to the SOFC stack, and its thermal energy was utilized to the extreme by gas expanders and the KC. The proposed hybrid system was investigated by building a complete system-level model based on uniting zero-dimensional components models. Performance evaluation of the hybrid system was presented by performing energy and exergy analyses of the subunits and overall system. The results showed that an energy efficiency of 64.2% for the hybrid system was got based on the lower heating value (LHV) of the gaseous fuel in a baseline operating condition. The analysis on exergy destruction in the main subunits indicated a potential for improvement in performance of the proposed system. For better understanding of the hybrid system, a study on parametric trends was presented to specify the best parameter ranges for system operation. [ABSTRACT FROM AUTHOR]

Critical heat flux (CHF) experiments were conducted in a uniformly heated horizontal helically-coiled tube to investigate the CHF characteristics at near the critical pressures with R134a as the working fluid. The experiments were performed over a wide range of parameters: pressure from 2.85 to 4.03 MPa, i.e., reduced pressures ( P r) ranging from 0.70 to 0.99, mass flux from 250 to 2100 kg m −2 s −1 , inlet subcooling from 45 to 160 kJ kg −1 and heat flux from 20 to 450 kW m −2 . Two types of CHF phenomenon which are dry-out (DO) and departure from nucleate boiling (DNB) have occurred under the experimental conditions. The DO happens at the lower pressures while the DNB happens at the higher pressures. The wall temperature shows a very different characteristic for the two types of CHF. Under the DO conditions, wall temperature gets a sudden rise firstly at the inner-side of the outlet cross-section and temperature at the other side remains on a lower level, while under the DNB conditions, wall temperature around the outlet cross-section jumps almost simultaneously. When the pressure is very close to the critical point, there is a constant pressure region where the wall temperature rises gently and the CHF no longer exists. The effects of the mass flux and inlet subcooling on CHF have also been discussed. Based on the experiment, a correlation applied for the pressure region close to the critical pressure was proposed to estimate the CHF in the horizontal helically-coiled tube. [ABSTRACT FROM AUTHOR]

[Display omitted] • Low calorific value coal fly ash and boiler slag were used to prepare artificial stone. • The activity of ashes was improved by physical resonance. • The artificial stones were only cured outdoor naturally without steam curing. • The compression strength reached 100.4 MPa with ashes utilization up to 80 wt%. • The whole industrial production was green, simple and low cost. Low calorific value coal fly ash and boiler slag with low silicon and aluminum content, low cementitious activity, is difficult to be large-scale applications. In this study, pilot and industrial scale tests were conducted to recycle low calorific value coal fly ash and boiler slag for the preparation of high valuable inorganic artificial stone, the activity of fly ash and boiler slag was activated by physical resonance without chemical activation. From the pilot test, it was determined that artificial stones enhanced by resonant activation behaved the higher compression strength of 75.35 MPa with 80 wt% fly ash and boiler slag utilization, which was about 45.18% increase in compression strength compared with that of conventional static agitation. The resonant activation agitation promoted the hydration reaction between fly ash and cement, generating more fibrous dense C-S-H gels. Afterword, 40 tons of raw materials were used to produce artificial stones, whose compression strength reached as high as 100.42 MPa. The whole production process was simple and pollution free, with solid waste utilization up to 80 wt%, creating a value of 160–170 US $/t. Hence, low calorific value coal fly ash and boiler slag have been realized in scale, high value and green application. [ABSTRACT FROM AUTHOR]

Indirect-contact heat exchangers have been widely used in various energy systems, and the precise tracking control of important heat transfer parameters, such as temperature, is vital for safe and efficient operation. However, the high nonlinearity of heat transfer and large disturbance brings difficulty to optimal control. Considering the strong perception and decision-making capabilities of deep reinforcement learning (DRL), this study proposed a supervisor control method combined DRL and proportional–integral–derivative (PID). A set of the fewest conveniently measurable variables was derived as agent observations to describe the heat transfer process effectively and thereby improve the control efficiency under large disturbances. In addition, the local heat transfer process was used as a training environment to reduce training costs significantly. Finally, superheat temperature control in a complex organic Rankine cycle was simulated with SIMULINK to evaluate the effectiveness of the proposed observation variables and the training and control methods. The results showed that the proposed control method achieved satisfactory performance. The average absolute tracking error was only 0.246 K under trained and untrained disturbances, whereas that of the PID control was 4.645 K. Compared with the model predictive control, the DRL-PID-based supervisory control evidently performed better under a large disturbance; the average absolute tracking errors under DRL-PID control and MPC were 0.288 K and 0.509 K, respectively. [Display omitted] • A DRL-PID-based supervisor control method for heat transfer process is proposed. • A set of measurable variables is derived to describe the heat transfer state. • The local process in a complex system is used as the training environment. • The proposed control method performs better than MPC under large disturbance. [ABSTRACT FROM AUTHOR]

Driver intention detection is an important component in human-centric driver assistance systems. This article proposes a novel method for detecting driver normal and emergency left- or right-lane-changing intentions by using driver models based on the queuing network cognitive architecture. Driver lane-changing and lane-keeping models are developed and used to simulate driver behavior data associated with 5 kinds of intentions (i.e., normal and emergency left- or right-lane-changing and lane-keeping intentions). The differences between 5 sets of simulated behavior data and the collected actual behavior data are computed, and the intention associated with the smallest difference is determined as the detection outcome. The experimental results from 14 drivers in a driving simulator show that the method can detect normal and emergency lane-changing intentions within 0.325 s and 0.268 s of the steering maneuver onset, respectively, with high accuracy (98.27% for normal lane changes and 90.98% for emergency lane changes) and low false alarm rate (0.294%). [ABSTRACT FROM AUTHOR]

Abstract: Presents a new system of air source energy independence driven by internal-combustion engine (EIICE), which used natural gas or other fuels as an independent input energy, and could provide the heating, cooling and hot water for the buildings efficiently. It also could provide electricity for electric equipments of the system. The performance of air source EIICE system was investigated theoretically and experimentally. The experimental and simulation results indicated that the heat capacity of plate heat exchanger (P-HE), heat recovered from exhaust gas heat exchanger (EG-HE), input power of compressor, output power of engine and fuel consumption increased with the increase of the rotary speed, water flow rate of the P-HE and evaporation temperature. Heat recovered from the cylinder jacket heat exchanger (CJ-HE) increased with the increase of the rotary speed and evaporation temperature, but decreased with the increase of the water flow rate of P-HE. The coefficient of performance (COP t ) and primary energy ratio (PER t ) of air source EIICE system also increased with the increase of the water flow rate of P-HE and evaporation temperature, but decreased with the increase of the rotary speed. [Copyright &y& Elsevier]

The effect of microstructure on the onset strain and rate of deformation-induced martensitic transformation (DIMT) in Q&P steel is studied by a mean-field micromechanics model, in which the residual austenite (RA) and primary martensite (M) phases are treated as elastoplastic particles embedded into the ferrite (F) matrix. The results show that when the volume fraction of the RA increases with a constant fraction of the M, the onset strain of DIMT increases and transformation rate decreases, in contrast to the case of the RA fraction effect with a fixed F fraction. Increasing the volume fraction of the M postpones the DIMT, regardless of the corresponding change from the RA or F fraction, which is similar to the effect of the RA fraction with the constant M but to a higher degree. Conversely, when increasing the fraction of the matrix F, the onset strain of DIMT increases and the rate decreases, and the effect is greater when the corresponding fraction change comes from the M rather than from the RA. Moreover, when the aspect ratio of the RA increases, the onset strain of DIMT decreases with a gradual increase in transformation rate, in agreement with the experimental observation that the equiaxial austenite is more stable in Q&P steels. However, the aspect ratio effect of the M is opposite to that of the RA, indicating that the lath-shaped primary martensite could protect the austenite from DIMT. [ABSTRACT FROM AUTHOR]

The organic Rankine cycle (ORC) technology is an attractive candidate for waste heat recovery and clean energy utilization. The operating condition of ORC system would change constantly under fluctuant heat source and a dynamic model is able to predict the transient behavior. The ORC dynamic model generally contains some unknown parameters while their identification is often ignored. This paper proposes a detailed calibration mechanism for ORC dynamic model including subcritical and transcritical system. Component models including pump, expansion valve and evaporator are well calibrated and the integrated calibrated system model is validated based on experimental data. Results indicate that calibrated model can capture the system dynamic behavior well. For key system state parameters such as working fluid evaporator pressure and outlet temperature, model prediction can achieve mean absolute relative deviation of less than 2% for both subcritical and transcritical system. Meanwhile, the conventional expansion valve model for transcritical system is found not efficient enough and a modification form is provided. This work can contribute to the calibration mechanism of similar thermodynamic system and enhance the confidence in model application. • An ORC dynamic model applying to subcritical and transcritical system. • A modified expansion valve flow equation for transcritical system. • Two types of correction multipliers in evaporator calibration. • The mean absolute relative deviation of less than 2% for model prediction. [ABSTRACT FROM AUTHOR]

• Various kinds of SOFC-based systems for building applications were reviewed. • System configurations and characteristics were analyzed and discussed. • Means, by which the system performance was assessed, were detailed. • An all-around performance demonstration of the systems was presented. • Possible strategies for a brighter prospect of development were discussed. Energy consumption in buildings has long been a target for reduction efforts, and in these efforts, adopting advanced technologies to design high efficient energy systems dominates buildings' energy supply side. To date SOFC systems are regarded as one of the most adaptable technologies for building applications in terms of efficiency, flexibility and environmental protection. In this paper, a comprehensive review of SOFC-based energy systems for building applications is presented from the aspect of system layouts and performance assessments. The first half of this review is structured by the way of distinguishing SOFC systems in power capacities, provided energy forms and thermal management, based on which the types of SOFC systems used in buildings are defined and classified, and various system configurations and characteristics are reviewed and analyzed. The latter part gives a thorough review on the performance assessment of SOFC systems designed to be used in buildings. The system-level model widely adopted to predict the system performance is presented. With regard to the SOFC module, a common electrochemical model evolved from the conservation laws of mass and energy is discussed. For performance demonstrations and specific building load features are inextricable, building loads calculations and system matching strategies in relevant literatures are discussed before presenting the review of energy efficiency, and economical and environmental benefits. Guided by the ever-growing environmental concerns, the end of this paper discusses possible strategies for a brighter prospect of SOFC systems for building applications. [ABSTRACT FROM AUTHOR]

• The reliable model of PR-CMTPC are developed and validated against experimental data. • High operating temperature is more conductive to greater power than pressure. • Optimal control strategy works well in slow step change but fails in transient change. • Constant pressure control is more suitable for transient conditions rather than slow step condition. Carbon dioxide mixture transcritical power cycle (CMTPC) is considered as a new promising technology for waste heat recovery (WHR), while there are still critical challenges arising from the transient fluctuations of heat sources when it comes to the heavy-duty diesel engines (HDDEs) applications. This paper presents a dynamic model of CMTPC systems, which is carefully validated against experimental data. Constant temperature, constant pressure and optimal control strategies are proposed to realize stable and optimal operation. The dynamic performance of the system with different control strategies is predicted under slow step change and transient change conditions. The results demonstrate that under slow step change conditions, the stability of optimal control system and constant pressure control system is better than that of constant temperature control system. In addition, the net power output keeps maximum under the optimal control because of the compromise between operating pressure and temperature. However, under transient conditions the control performance of optimal control is not as obvious as under slow step change conditions. Compared with open loop system, the improvement of system power by optimal control under slow step change is 2.31%, while that is only 0.07% under transient change condition. By contrast, it is found that the constant pressure control achieves the best power improvement of 0.58% under transient conditions because of the satisfactory control effect on operating pressure and relatively small fluctuations of expander inlet temperature. In a word, different control strategies behave obviously different performance under various conditions. [ABSTRACT FROM AUTHOR]

About 2/3 of the combustion energy of internal combustion engine (ICE) is lost through the exhaust and cooling systems during its operation. Besides, automobile accessories like the air conditioning system and the radiator fan will bring additional power consumption. To improve the ICE efficiency, this paper designs some coupled thermal management systems with different structures which include the air conditioning subsystem, the waste heat recovery subsystem, engine and coolant subsystem. CO2 is chosen as the working fluid for both the air conditioning subsystem and the waste heat recovery subsystem. After conducting experimental studies and a performance analysis for the subsystems, the coupled thermal management system is evaluated at different environmental temperatures and engine working conditions to choose the best structure. The optimal pump speed increases with the increase of environmental temperature and the decrease of engine load. The optimal coolant utilization rate decreases with the increase of engine load and environmental temperature, and the value is between 38% and 52%. While considering the effect of environmental temperature and road conditions of real driving and the energy consumption of all accessories of the thermal management system, the optimal thermal management system provides a net power of 4.2 kW, improving the ICE fuel economy by 1.2%. [ABSTRACT FROM AUTHOR]