The high penetration of wind and photovoltaic (PV) in renewable bases poses significant challenges to peak shaving and primary frequency regulation. However, relying solely on thermal power for Wind-PV-Thermal Systems provides limited regulation capacity due to the several times renewable-to-thermal capacity ratio. Moreover, thermal power exhibit severe regulation capability degradation under deep peak-shaving conditions, creating a critical conflict between these two objectives. To address this challenge, this study proposes a Hybrid Energy Storage System (HESS) comprising molten salt electric heating energy storage, lithium-ion batteries, and flywheel energy storage for a gigawatt-scale Wind-PV-Thermal Systems in Inner Mongolia, China. A novel multi-objective optimization framework is developed with three objectives for coordinated optimization: Peak-Valley Mitigation Index (PVMI), Bidirectional Regulation Ratio (BRR), and Total Bidirectional Regulation Energy (Total_Bidir). Two additional novel performance metrics are introduced for comprehensive evaluation: Asymmetric Regulation Ratio (ASR) and Bidirectional Regulation Capability Index (BRCI). A Mixed-Integer Programming model is established to capture the distinct dynamic characteristics of different storage technologies, and four optimization algorithms are systematically compared. Results across 12 representative test dates demonstrate that the proposed HESS integration achieves a peak-to-valley difference reduction of up to 10.59% and enhances the bidirectional regulation capability index by up to 260.10% compared to the baseline Wind-PV-Thermal Systems without HESS. The MIP method substantially outperforms metaheuristic algorithms across all performance metrics, but requiring longer computation time. The Hybrid Energy Storage System (HESS) configuration and the proposed multi-objective optimization framework together effectively provide a practical solution for large-scale renewable energy integration.

A NiFeCoMnMo high-entropy catalyst shows enhanced OER activity. Mo tuning optimizes the electronic structure and induces surface reconstruction to an active oxyhydroxide, promoting kinetics and stability with possible lattice oxygen involvement.

Atmospheric CO2 reduction into chemicals is crucial for carbon cycling. However, when using traditional solardriven thermochemical cycles for carbon dioxide conversion, the required temperature exceeds 1300 degrees C, leading to excessive energy demands and significant obstacles in technological scaling. This study introduces a two-step thermochemical cycling system utilizing microwave-excited non-equilibrium gadolinium-doped CeO2 (CGO). We analyzed the power threshold of the system, as well as the effects of different material doping concentrations and gas components introduced during the oxidation process on the reaction. The system achieves faster carbon dioxide conversion than conventional methods, reducing the reaction temperature by 77 % (from 1300 degrees C to 380 degrees C) and reducing the reaction time by 94 %.Under optimal conditions, the yield of O2 and CO in a single cycle is 0.77 mL/g and 1.11 mL/g, respectively. The kinetic analysis revealed that the apparent activation energy of the microwave-driven CGO is 69.48 kJ/mol, which is 52 % lower than that of traditional thermal activation methods. Furthermore, the microwave-to-chemical energy conversion efficiency reaches 11 %-20 %, surpassing the performance of traditional solar thermochemical approaches. This study further explores the microwavedriven CO2 conversion process and optimizes the reaction conditions, and also shows a good industrial application prospect.

The overuse of fossil fuels has triggered environmental issues such as climate change, while traditional hydrogen production technologies either require extremely high temperatures or suffer from low energy efficiency, failing to meet sustainable development demands. This study proposes a novel two-step hydrogen production method via solar-microwave synergistic water splitting using Ce0.8Gd0.2O1.9 (CGO). Hydrogen production experiments through water splitting were conducted under simulated sunlight and microwave irradiation, with results compared to those obtained using microwave irradiation alone. The results show that the reaction time is significantly shortened by the synergistic technology compared with the pure microwave hydrogen production. The reduction step time is reduced by up to 92.3%, while the oxidation step time is reduced by up to 37.8%. The microwave power threshold required to initiate the reaction decreases from 120 W to 70 W. The complementary advantages of the two energy sources-with solar power providing the primary heat and microwaves activating the chemical reaction-reduce energy waste and accelerate the reaction process. Both hydrogen production efficiency and energy utilization efficiency are markedly improved, with enhanced reaction process stability. After 5 cycles, the total energy utilization rate of the cooperative system is 4.6% higher than that of the pure microwave system. This study demonstrates that solarmicrowave synergistic technology represents an efficient, low-energy green pathway for hydrogen production, offering important technical insights for future renewable energy-driven hydrogen manufacturing.

The electronic structures, the dielectric spectra and the absorptive spectra as well as the photocatalytic efficiency for H2 production of GeH/InSe have been investigated based upon stability evaluation via energetic, thermodynamic and mechanic calculation. The investigated results indicated that the GeH or InSe shows the indirect gap features with eigenvalues of 1.662eV and 2.038eV respectively, the GeH/InSe heterojunction appears a direct gap feature with an eigenvalue of 1.187eV. The band edges analysis of GeH/InSe heterojunction and its components identified that GeH/InSe meets the feature of direct Z-scheme heterojunction, implying the excited e on CBMInSe can recombine with h on VBMGeH, resulting in the HER occurred on the surface of GeH while the OER proceeded on the counter surface InSe. The exploration of tensile or compressive strain applied on GeH/InSe heterojunction indicated that an optical redshift effect takes place apparently, and the tensile strain makes the number of absorption peaks increase. The tunable effects coupled with remarkable carriers' mobility enable the photocatalytic efficiency for hydrogen production being enhanced from 40.69% to 45.15% when tensile strain is increased from 0% to +2%.

In concentrated solar power (CSP) systems, solar salt serves as a crucial heat transfer and storage medium. However, there are significant variations in the reported decomposition temperatures of this salt under operation conditions. In this study, we employed synchronous thermal analysis (STA) to combine thermogravimetric (TG) and differential scanning calorimetry (DSC) data for a systematic investigation. The focus was on understanding the effects of sample mass, heating rate, and atmospheric conditions on the high-temperature decomposition of solar salt. Our research led to several key findings: Firstly, an increase in sample mass (from 4.676 to 88.10 mg) resulted in an exponential increase in decomposition temperature, reaching 677.03 degrees C (88.10 mg). Interestingly, 70 % of the residual mass was attributed to limitations in heat and mass transfer. Secondly, varying heating rates (from 2 degrees C/min to 20 degrees C/min) caused thermal hysteresis, elevating the decomposition temperature by as much as 72.07 degrees C (from 561.37 degrees C to 633.44 degrees C). When extrapolated to 0 degrees C/min, the intrinsic decomposition temperature was determined to be 514.85 degrees C. Thirdly, using a nitrogen atmosphere resulted in a reduction of 21.80 degrees C in the decomposition onset temperature compared to air (578.18 degrees C versus 599.98 degrees C), and also enhanced the completeness of decomposition by reducing oxygen diffusion barriers. Finally, the melting enthalpy peaked at 139.19-139.68 J/g (10-15 degrees C/min), while the decomposition enthalpy fluctuated depending on the testing parameters. This study has established an intrinsic temperature benchmark that could provide valuable insights for standardizing material evaluation and optimizing operational safety in CSP plants.

This study investigates the high-temperature energy storage density and cyclic stability of Ca0.8Mg0.1X0.1O calcium-based carriers in the CaCO3/CaO thermochemical cycle, where X represents Al, Ga, Sc, and Y. A temperature-dependent enthalpy framework was established for CaCO3 decomposition, and the reaction enthalpy at 800 degrees C was determined to be 167.62 kJ mol(-1), about 6.0% lower than the standard value at 25 degrees C. For Ca0.8Mg0.1Al0.1O, the energy storage density derived from mass change was 24.45% higher than that obtained by direct calorimetric measurement, indicating that conventional evaluation may overestimate the actual heat-storage performance under high-temperature conditions. Among the four samples, the Al-containing material showed the best long-term performance and maintained the highest energy storage density after 50 cycles. Microscopic characterization confirmed the distribution of the dopant elements in the synthesized materials. The improved stability of the Al-containing sample is consistent with equilibrium-composition analysis and previous literature reporting the formation of CaO center dot Al2O3-related composite phases. These results provide a more realistic basis for evaluating CaO-based thermochemical carriers and for understanding dopant-dependent cyclic stability.

Ceramic dielectric materials with high dielectric strength and mechanisms of their internal factors affecting dielectric strength are significantly valuable for industrial application, especially for selection of suitable dielectric materials for high-power microwave transmission devices and reliable power transmission. Pure magnesium oxide (MgO), a kind of ceramic dielectric material, possesses great application potential in high-power microwave transmission devices due to its high theoretical dielectric strength, low dielectric constant, and low dielectric loss properties, but its application is limited by high sintering temperature during preparation. This work presented the preparation of a new type of multiphase ceramics based on MgO, which was MgO-1%ZrO2-1%CaCO3-x%MnCO3 (MZCM(x), x = 0, 0.25, 0.50, 1.00, 1.50, in molar), and their phase structures, morphological features, and dielectric properties were investigated. It was found that inclusion of ZrO2 and CaCO3 effectively inhibited excessive growth of MgO grains by formation of second phase, while addition of MnCO3 promoted the grain boundary diffusion process during the sintering process and reduced activation energy for the grain growth, resulting in a lower ceramic sintering temperature. Excellent performance, including high dielectric strength (E-b = 92.3 kV/mm) and quality factor (Q x f = 216642 GHz), simultaneously accompanying low dielectric loss (< 0.03%), low temperature coefficient of dielectric constant (20.3x10(-6) degrees C-1, 85 degrees C) and resonance frequency (-12.54x10(-6) degrees C-1), was achieved in MZCM1.00 ceramics under a relatively low sintering temperature of 1350 degrees C. This work offers an effective solution for dielectric materials for microwave transmission devices.

This paper studies the stability of energy flow dynamics in complex networks, emphasizing the impact of representative topological structures on control performance. Such networks frequently appear in transportation, power distribution, financial, and demographic systems, where nodes and edges represent hosts and transmitters of energy. Motivated by the critical role of topology in physical and engineering contexts, we focus on canonical network prototypes, including small-world and related structures observed in practice. A unified dynamic model is presented, and stability is quantified using L1/L∞ and Hankel norms. Extensive numerical experiments on statistically robust, large-scale networks illustrate how subtle topological variations significantly influence stability behaviors. These results offer theoretical insights and practical guidance for enhancing the control of energy flow in complex networks.

Bismuth sodium titanate (BNT)-based piezoelectric materials are the most promising candidates for lead-free actuator applications. With the request for integration and size miniaturization of devices, it is urgent to develop thin films for microdevices to be compatible with semiconductor processes. Through composition engineering, BNT-based thin films were fabricated on silicon substrates, with ultra-high strain response and negligible hysteresis in strain curves. The DC-dependent and temperature-dependent dielectric properties were collected to investigate the relaxor state of thin films. The structure and polarization transition and evolution as a function of electric field and time were analyzed based on the electric characterization, in-situ Raman measurements, and dynamics PFM. The reversible phase transition and polarization order-disorder transformation are the most significant features for reaching a large strain of >1.6% in BNT-based thin films.

To address the application requirements for relative radiometric calibration and image non-uniformity correction of multi-CCD cameras during on-orbit operations,this study proposes an LED point source-based relative radiometric calibration method for spaceborne systems. Grounded in the inverse-square law of point source irradiance,this methodology employs spatially fixed stable light sources as radiometric references. By establishing a comprehensive technical framework encompassing laboratory cross-comparison calibration,on-orbit calibration coefficient correction,and performance verification,it achieves full lifecycle monitoring and correction of relative radiometric calibration for remote sensing payloads. Through laboratory analysis of the spectral irradiance spatial distribution characteristics of LED point source modules,we established the correlation between light intensity spatial distribution and point source spectral irradiance. This enabled the calculation of spectral irradiance spatial distribution formed by point source modules at the focal plane. Combining with relative radiometric calibration ratios measured by highly uniform integrating sphere light sources,we derived spatial distribution coefficients for the relative radiometric calibration of point source modules. Post-launch secondary correction of calibration coefficients ultimately formed the on-orbit relative radiometric calibration and non-uniformity correction algorithm. Laboratory measurements of irradiance distribution at various imaging positions under different driving currents confirmed system stability with ratio distribution relative standard deviation <= 0.05%, verifying current-independent performance stability. Algorithm validation employed image data with integration times from 8 ms to 16 ms to simulate surface reflectance variations. Post-correction results demonstrated significant non-uniformity improvement quantified by generalized noise assessment: non-uniformity decreased from 1.75% to 0.97% at 8 ms,1.55% to 0.89% at 12 ms, and 2.28% to 1.28% at 16 ms. A multi-LED combination calibration strategy with energy-level matching enables wide-spectrum multi-level radiometric energy input through established energy-current relationships. System performance tests revealed exceptional stability-LED source on-off cycling stability over 30 minutes exceeded 0.08%,with post-irradiation energy variation across all levels below 1%,fully meeting on-orbit stability requirements. This methodology provides an effective solution for real-time radiometric correction of spaceborne payloads,demonstrating significant application value for ensuring reliable on-orbit instrument operation.

Iodine-fed electric propulsion systems have achieved significant technological progress in recent years, the operating range of these systems remains fundamentally limited by ampere level iodine compatible hollow cathode technology. Preliminary studies on discharge characteristics have found that LaB6 hollow cathode is a potential strategy. In this study, a conventional LaB6 hollow cathode made with iodine-resistant materials was designed and tested in an iodine-compatible vacuum facility. The waveform, bispectral characteristics, and dispersion relation of the iodine hollow cathode were obtained and compared with the estimated collision reaction frequency. We analyzed the potential reaction processes both inside and outside the cathode and assessed how oscillation affects the lifetime of the iodine hollow cathode. The results indicate that the chaotic lowfrequency oscillations were the main oscillation mode affecting the performance of the iodine cathode, involving multiple reaction processes that interfere with each other. The oscillation inside the cathode was mainly affected by vibrational excitation and iodine molecular ionization, while the oscillation outside the cathode was affected primarily by processes such as neutral gas flow, excitation, ionization, dissociation, and ion transit-time instability. The overall oscillation of iodine cathode is a non-dominant unstable mode with uniform energy distribution. A single 27-h self-sustaining experiment found that low-frequency oscillation has a significant impact on the emitter and the orifice, thereby reducing the cathode lifetime. The main reaction process inside and outside the iodine cathode and the influence relationship between the reactions were understood by the oscillation characteristics. It provides a theoretical basis to improve the performance of the iodine hollow cathode in the future.

Global energy consumption is significantly impacted by the thermal regulation demands in the industrial and building sectors, creating an urgent need for sustainable thermal energy solutions. Passive radiative cooling (PRC) has emerged as a promising strategy, capitalizing on the natural thermal exchange between Earth and outer space to achieve cooling without electricity input. Recent advancements in PRC materials and systems have prompted researchers to explore wider applicability and enhanced functionality. PRC study now extends beyond cooling-optimized spectral designs focused on high solar reflectance and thermal emittance. The current primary research gap centers on leveraging PRC technology to address thermal management needs beyond mere cooling while incorporating specific functionalities for various practical applications. In this perspective, we analyze the current challenges in PRC implementation and identify potential research opportunities for future exploration. Additionally, this perspective seeks to stimulate innovative approaches to PRC design that address real-world applications, bridging the gap toward diverse practical thermal management solutions.

Currently, iodine-compatible cathodes for iodine propulsion systems that can provide ampere-level electron currents with a reasonable power consumption are lacking. In this study, a conventional LaB6 hollow cathode made with iodine-resistant materials was designed and tested in an iodine-compatible vacuum facility. The ignition characteristics, the V-I (Volt-Ampere characteristic) curve, and long steady-state discharge sequence of the iodine hollow cathode were analyzed and compared with those using a krypton propellant. After the experiment, the composition of the cathode emitter was studied by scanning electron microscope and energy-dispersive X-ray spectroscopy (EDS). The results show that ignition takes > 10 s to reach a steady state, and the discharge voltage of the iodine was 25-95 V higher than that of krypton. According to the EDS results, this was mainly caused by emitter contamination with iron from the stainless-steel components of the cathode and oxygen from the iodine feed system. The iodine hollow cathode achieved a cumulative 12.5 h stable discharge, with the longest single discharge of 5 h and a 3% change in the inner diameter of the emitter.

The wall heat flux (WHF) in a hypersonic turbulent boundary layer over a 24° compression ramp at Mach 6.0 is studied based on direct numerical simulation with the grid point number up to 3.5 billion and the Reynolds number based on momentum thickness of 8200. An apparent spanwise non-homogeneity of the mean WHF is observed on the compression ramp, caused by large-scale Görtler-type streamwise vortices. The pre-multiplied spanwise energy spectra of the fluctuating WHF reveal two energetic spanwise length scales in the interaction region, which are associated with the elongated streaky structures and Görtler-type vortices, respectively. The probability density functions of the fluctuating WHF in the interaction region are much more negatively skewed than that in the upstream flat-plat boundary layer, and the probability that the extremely high WHF occurs is significantly increased, both of which are found to be caused by the spanwise large-scale vortical structures via applying the low (high)-wavenumber-pass filter technique. The mean WHF in the interaction region is significantly increased, and two local maximum peaks are obtained. The upstream one lies just downstream of the reattachment position, arising from the significantly increased temperature peak value nearby and the strong downward motion that transports the relatively high-temperature fluid toward the wall. The other one is associated with the combined influence of the strong mean convection and turbulent mixing as well as the high viscous dissipation. The Reynolds analogy factor reveals an obvious variation in the interaction region, and its streamwise distribution downstream of the reattachment position is similar to the ratio of the total viscous dissipation and its component related to the wall-normal gradient of the streamwise velocity.

Passive daytime radiative cooling (PDRC), an energy-saving and environmentally friendly strategy, achieves cooling without any power consumption by reflecting sunlight and radiating energy to outer space. Herein, it is shown that a porous-structured poly(dimethylsiloxane)/silicon oxide (PDMS/SiO2) composite foam is fabricated through "pore in pore" engineering, in which a three-dimensional self-supporting silicon dioxide (SiO2) network is constructed in the pores of PDMS foam fabricated via freezing casting. The PDMS/SiO2 foams exhibit a hierarchical porous structure like "SiO2 assembling pores in PDMS micropores" and significantly benefit the reflectivity and infrared emissivity. An average solar reflectivity of similar to 90.1% within a full spectral range of 0.3-2.5 mu m and an average emissivity of similar to 94.1% in the atmospheric window allow for the temperature inside the foam cavity to drop by similar to 11.1 degrees C under direct sunlight with the solar radiation intensity of 871 W m-2. Notably, the hierarchical porous PDMS/SiO2 foams exhibit excellent thermal insulation, antifouling, and hydrophobic performances, weakening the heat flow from the external environment and ensuring long-term outdoor use. Such a powerful radiative cooling performance integrated with thermal insulating and antifouling capability by the foams constructed by "pore in pore" engineering offers a way to efficiently manage sunlight radiation energy to make devices, vehicles, buildings, and other urban objects cooler and helps to save energy in an outdoor sunlight environment.

In the solar reflective band, the on-board calibration method based on a solar diffuser (SD) is the mainstream calibration method. However, the calibration accuracy is limited by the measurement accuracy of the SD bidirectional reflectance distribution function (BRDF) in the laboratory. The limitations of the light sources and detectors hinder accurate BRDF measurements in the short-wave infrared band, particularly beyond 1700 nm. In this study, the angle integration-band crossing transfer (AIBCT) method is proposed for SD BRDF measurement to avoid the influence of the Fourier spectrometer's signal processing and detector non-linearity in the absolute measurement. The method utilized the relationship between the BRDF and directional-hemispherical reflectance, and calculated the spectral distribution of the SD BRDF at the standard in-plane geometry with an 0 degrees incidence zenith angle and a 45 degrees reflection zenith angle (0:45) by integration. The absolute measurement result of the 0:45 SD BRDF at 1150 nm was used as the standard for transfer to the short-wave infrared band. The SD BRDF at 0:45 was generalized to other geometries through relative measurements based on the reciprocity theorem. The mean relative error of the results of the AIBCT and absolute measurement methods was less than 0.3% in the range of 1100 nm to 1600 nm. Analysis of the results showed that the AIBCT method's measurement uncertainty (coverage factor k = 2) of the 0:45 SD BRDF is better than 0.84% at 1100 nm to 2300 nm and 1.05% at 2300 nm to 2500 nm. Furthermore, the AIBCT method was found suitable for the ultraviolet band.

Integrating heat pipe technology into blackbody radiation sources significantly enhances thermal consistency and accuracy. Nonetheless, at elevated temperatures, pressure fluctuations in water heat pipe blackbody systems may induce catastrophic failures. This issue was addressed by theoretically conceptualizing, engineering, and implementing rupture discs designed to alleviate pressure under predetermined conditions, thereby enhancing system safety. A water heat pipe blackbody source equipped with rupture discs was constructed, and a series of relevant empirical tests were executed. The burst pressure measured under standardized hydraulic evaluation reached 5.65 MPa, closely matching the theoretically calculated burst pressure of 5.60 MPa, with a minimal deviation of 0.88 %, thus confirming the model's precision. Under extreme testing conditions at 260( degrees)C and 4.80 MPa, the rupture disc burst prematurely at 3.66 MPa due to rapid heating. However, in step heating scenarios, the rupture disc's performance was within 4 % deviation from the theoretical predictions, demonstrating its reliability.