Traditional photothermal membrane distillation (PMD) for seawater desalination suffers from low photothermal conversion efficiency and poor operational stability under high-salinity brine conditions. In response to these limitations, this study reports a hydrogel composite membrane (HCM) mediated photothermal membrane distillation device. The HCM consists of a chitosan/agarose hydrogel (CAH) layer, carbon nanotube (CNT) coating, and polytetrafluoroethylene (PTFE) hydrophobic membrane. The CNT layer significantly improves the photothermal conversion efficiency, achieving 98.5% solar absorption under standard solar irradiation. The CAH modulates intermediate water states by tuning the chitosan-to-agarose ratio, thereby reducing water evaporation enthalpy and enabling stable freshwater production. Under 1 kW m-2 solar intensity (i.e. 1 sun) for 1.5 h, the water flux of the device increased by 40.7% than pure CNT/PTFE membrane. Simultaneously, CAH employs its three-dimensional porous structure and abundant amino (-NH2) and hydroxyl (-OH) groups to achieve synergistic salt rejection through electrostatic repulsion. The device achieved continuous and stable freshwater production in a 7 wt% NaCl solution, demonstrating outstanding salt-rejection properties. This study developed hydrogel composite membrane to enhance water flux and system stability in PMD, proposing novel concepts for performance enhancement of PMD.

The integrated photothermal catalytic technology that combines photothermal membrane distillation and water splitting for simultaneously producing freshwater and hydrogen is a promising solution to address water resource and energy crises. However, interfacial salt crystallization during seawater evaporation and achieving stable hydrogen production remain key challenges. This study develops a chitosan/agarose hydrogel-based photothermal catalytic composite membrane (HPCM) for solar-driven water-hydrogen coproduction. The membrane employs a hierarchical architecture featuring an upper hydrophilic chitosan/agarose hydrogel layer that enables rapid water transport and in-situ salt rejection through its three-dimensional porous network, effectively preventing salt crystallization at the evaporation interface. The lower layer consists of a hydrophobic PTFE membrane loaded with Pt-TiO2 nanoparticles, which drives photocatalytic water splitting under illumination while leveraging PTFE's microporosity to enhance hydrogen evolution. The dual-layer architecture simultaneously enables integrated desalination and hydrogen production. The hydrogel layer effectively prevents salt accumulation to ensure long-term operational stability, while the Pt-TiO2/PTFE layer efficiently catalyzes hydrogen generation and enhances gas diffusion. HPCM composite membrane was integrated into an air-gap membrane distillation (AGMD) system. The HPCM-AGMD demonstrates exceptional desalination performance (>99.9% salt rejection) and operational stability under 1.0 sun irradiation. Under 1.5 sun, the system achieves a water production flux of 0.52 kg m−2 h−1 and a hydrogen production rate of 3.00 mmol m−2 h−1. Cycling and continuous operation tests confirm the system's durability, while outdoor experiments further validate its practical feasibility under natural sunlight. This work offers a new approach to developing efficient, compact, and low-maintenance solar energy utilization systems.

Open loop heat pipe desalination (OHLPD) can achieve a high water production rate with a small temperature difference, without consuming additional mechanical power. In this study, a steady-state model of the OLHPD system was established to investigate its water-production performance, operating modes, pressure-drop distribution, and the effects of compensation-chamber position and vapor-line geometry. The simulation results demonstrate that the system can effectively utilize low-grade waste heat at 33-37 °C (such as thermal discharge from coastal power plants, resulting in near-zero thermal energy cost) achieving a water production rate of 10-45 kg/(m2·h). The overall flow resistance is identified as the primary factor limiting system performance, with the vapor line contributing approximately 45% of the total pressure drop. Consequently, shortening the vapor line or enlarging its inner diameter can significantly enhance the water production. The driving temperature difference also exerts a marked influence: within the investigated heat-source temperature range of 33-37 °C, the water production rate increases by approximately 46% on average for each 1 °C increase in the heat-source temperature, whereas a 1 °C decrease in the heat-sink temperature yields an approximate 4% improvement. Positioning the compensation chamber above the evaporator allows gravity to assist the capillary driving force, thereby enhancing water production. In this configuration, the system operates in either a gravity-driven or a capillary-gravity co-driven regime, with the former to be avoided to prevent seawater breakthrough.

Solar-driven interfacial evaporation desalination technology offers a feasible solution to the global shortage of freshwater resources. However, previous interfacial evaporation technologies have often only focused on the production of freshwater resources, without fully utilizing the high-energy photons in sunlight and the salinity gradient generated after seawater evaporation. In this work, a solar-driven water–hydrogen–electricity (SWHE) co-production system integrated by solar-driven interfacial evaporation (SIE), interface photocatalytic hydrogen evolution (IPHE), and reverse electrodialysis (RE) was proposed. The aim is to enhance the efficiency of solar energy utilization and achieve simultaneous production of freshwater, hydrogen, and electricity. Under 2-sun irradiation, the SWHE device achieved a water generation rate of 0.77 kg m−2 h−1, a hydrogen generation rate of 8.57 mmol m−2 h−1, and a highest power density of 2.9 mW m−2. Outdoor tests demonstrate that the cumulative water production reached 1.6 kg m−2 over 6 h, with a total hydrogen yield of 12.22 mmol m−2 and a highest power density of 0.095 mW m−2, which validated the environmental adaptability of SWHE system. This novel design strategy is expected to provide a novel form of freshwater resources and energy supply for human society.

The shortage of freshwater resources and the depletion of fossil fuels have emerged as two pivotal challenges confronting global development. Photothermal membrane distillation (PMD) technology, a technique that harnesses solar energy for seawater desalination, not only produces freshwater but also mitigates the pressure of energy depletion. However, its sole focus on freshwater production no longer meets the demands of the energy market. Based on this, this study proposes a power–water cogeneration system based on PMD and thermal-osmotic energy conversion (TOEC) technology. The system achieves power–water cogeneration by changing the supply side heat source structure of TOEC technology and coupling it with traditional PMD technology. The experimental results showed that under the illumination condition of solar intensity of 4 kW·m−2 for 3.5 h, the fresh water production and water production rate of the system reached 2.23 g and 1.39 kg·m−2·h−1, respectively. Meanwhile, the fresh water output pressure reached 0.91 bar, and the output power density was 0.0456 W·m−2. This system is expected to provide a new solution to address the global shortage of freshwater resources and the depletion of fossil fuels.

Three types of heat transfer structures were constructed base on a LaNi5-type rare earth-based hydrogen storage alloy as hydrogen storage medium by the method of strengthen heat conduction and mass transfer,and the heat transfer charac-teristics of each structure and their loading characteristics in solid state hydrogen storage tanks were measured.Importantly,we conducted the key research on hydrogen charging/discharging of solid state hydrogen storage tanks,then compared and evaluated the effect of three types of heat transfer structures on the hydrogen charging/discharging performance of the filled sol-id state hydrogen storage tanks,and thoroughly analyzed the heat conduction behavior of solid state hydrogen storage tanks dur-ing the hydrogen charging/discharging process using simulation methods finally.The results show that:The incorporation of a-luminum and graphite,which are high thermal conductivity materials,as well as the unique design of heat transfer structures,extremely improve the thermal conductivity and hydrogen charging/discharging thermodynamic and kinetic level of solid state hydrogen storage tanks.Among the three types of heat transfer structures,RE09 particles/Al scrap/Al fins composite structure(structure-Ⅱ)exhibits the optimum hydrogen charging/discharging performance because of its stable structure and distin-guished heat and mass transfer efficiency.Simulation results show that the temperature of three types of heat transfer structures decreasing gradually outward along the radius,which means that the core of the structures turn into the hottest zone,and the maximum temperature of RE09 particles/Al scrap/Al fins composite structure(structure-Ⅱ)and RE09 powder/expanded graphite powder compressed disks structure(structure-Ⅲ)is almost 400 ℃ lower than RE09 particles structure(structure-I).Heat flux distribution connects closely with heat transfer structure form,excellent heat transfer structure design stimu-lates the heat flux flowing to the higher thermal conductive medium rather than gathering in alloy,and elevate the hydrogen charging/discharging kinetic level of solid state hydrogen storage tanks.

Excessive discharges of chemical dyes have led to severe contamination of seawater, resulting in significant ecological damage. Thermo-osmotic energy conversion technology, which purifies wastewater and generates electricity under temperature gradients, has garnered considerable interest from researchers. However, the operational efficiency of thermo-osmotic energy conversion is inherently limited by the effective membrane area, and conventional systems typically employ flat membranes as separators, resulting in suboptimal performance for the same floorage. In this study, we introduce a novel system that combines thermo-osmotic energy conversion technology with hollow fiber membranes that possess a high effective membrane area, thereby achieving optimized performance. Driven by the temperature gradient, the water in the dye solution condenses outside the membrane and converted from vapor to liquid. The continuous accumulation of condensed water generates pressure and drives a water turbine for sustainable power generation. Our results demonstrate that at temperature gradient of 40 degrees C, the system can achieve the power output of 16.75 Wm(-3) and the freshwater production rate of 70.29 kg m(-3) h(-1) under ideal conditions. This study presents a novel water-electricity co-production system based on low-grade waste heat recovery for dye solution treatment, which extends the applicability of thermo-osmotic energy conversion technology and improves its practicality.

A novel Mach-Zehnder-interferometer (MZI)-based external cavity diode laser (ECDL) has been proposed and theoretically investigated in this study as a light source for tunable diode laser absorption spectroscopy (TDLAS). The proposed model can modulate the dual-arm optical path difference and the round-trip optical path length of the ECDL external cavity. The results demonstrate that the wavelengths of a certain MZI pass band center and the ECDL external cavity longitudinal mode may track each other over a significant range of voltage variation leading to mode-hop-free performance. Therefore, it can be used in the TDLAS system for gas detection and characterization and is expected to replace the DFB laser.

A multistage laser-wakefield accelerator with curved plasma channels was proposed to accelerate electrons to TeV energy levels. In this condition, the capillary is discharged to produce plasma channels. The channels will be used as waveguides to guide intense lasers to drive wakefields inside the channel. In this work, a curved plasma channel with low surface roughness and high circularity was fabricated by a femtosecond laser ablation method based on response surface methodology. The details of the fabrication and performance of the channel are introduced here. Experiments show that such a channel can be successfully used to guide lasers, and electrons with an energy of 0.7 GeV were achieved.

Low-grade heat energy is enormous and widely distributed around the world, but it cannot be effectively converted to electricity owing to the small temperature difference and fluctuating heat source. As a promising technology that can convert low-grade heat energy into electricity while obtaining additional freshwater, thermo-osmotic energy conversion has attracted attentions of numerous researchers. However, traditional thermo-osmotic energy conversion technologies lack the utilization of the accompanying variation in salinity gradients throughout the process. In this study, a hybrid system was presented to achieve simultaneous freshwater production and electricity generation by combining thermo-osmosis system with a salinity gradient power recovery module. Continuous operation of the thermo-osmosis system will naturally produce a range of salinity differences, which will then be converted into electricity by the salinity gradient power recovery module. Our results show that this hybrid system can optimally increase the electricity output by-0.99 W m- 2 over the conventional thermo-osmotic energy conversion system. Overall, our research demonstrates a promising device to harvest low-grade waste heat for co-generation of electricity and freshwater. This innovative approach has the potential to broaden the application possibilities of thermo-osmosis technology.

Harvesting low-grade heat energy for simultaneous desalination and power generation is a meaningful and valuable work to address the energy and fresh water crisis. Here we report a novel hybrid system for cogeneration of fresh water and electricity by coupling thermal osmosis unit and an electrokinetic power generator. Pressured fresh water will be produced in the confined cold side by the temperature difference across the hydrophobic PTFE membrane, based on the principle of membrane distillation. Pressured driven fresh water flows into the electrokinetic module and through the microchannels from one reservoir to the other, electricity will then be generated based on the ion selection effect at the microchannel walls. Fresh water production rate of 18.46 kg m- 2 h-1 and output power density of 1.12 W m- 2 were simultaneously obtained by this device at a temperature difference of 50 degrees C. This study combined the recovery of latent heat energy and desalination, which may expand the application approaches of low-grade heat energy recovery.

Desalination through reverse osmosis (RO) membrane is one of the most popular ways. However, conventional RO membranes meet a trade-off between salt rejection and water flux which limit their comprehensive performance. In this work, sulfonated zirconium (IV)-carboxylate metal–organic framework (MOF) material UiO-66-SO3H was successfully synthesized, and thin-film nanocomposite (TFN) with UiO-66-SO3H-incorporated polyamide (PA) layer was fabricated. Angstrom-sized UiO-66-X ion transport channels with different functional groups in TFN membranes change the membrane morphology and chemistry and accelerate the penetration of water molecules while maintaining the high ion screening effect. As a result, compared to the pristine TFC membrane, the optimized TFN-UiO-66-SO3H membrane exhibited an increase in water molecules permeability to 347% and still maintained a salt rejection with ~ 94.7% under 2000 ppm NaCl solution with reverse osmosis (RO) mode, leading to a great improvement of intrinsic separation properties. The improved performance was owing to the size exclusion effect and hydrophilic nature of UiO-66-SO3H particles. What is more, the additional water migration channels through the incorporated UiO-66-SO3H nanoparticles lead to a boosting water permeation and show optimized performance for desalination.

Electrochemical extraction of lithium from seawater/brine is receiving more and more attention because of its environment-friendly and energy-saving features. In this work, an electrochemical lithium extraction system with gas flushing of porous electrodes is proposed. We verified that the operation of multiple gas washes can significantly reduce the consumption of ultrapure water during the solution exchange and save the time required for the continuous running of the system. The water consumption of multiple gas flush operations is only 1/60 of that of a normal single flush to obtain a purity close to 100% in the recovery solution. By comparing the ion concentration distribution on the electrode surface in flow-through and flow-by-flow modes, we demonstrate that the flow-through mode performs better. We also verified the lithium extraction performance of the whole system, achieving a purity close to 100% and average energy consumption of 0.732 kWh∙kg−1 in each cycle from the source solution of the simulated Atacama salt lake water. These results provide a feasible approach for the large-scale operation of electrochemical lithium extraction from seawater/brine.

The Large High Altitude Air Shower Observatory (LHAASO) has three sub-arrays, KM2A, WCDA, and WFCTA. The flux variations of cosmic ray air showers were studied by analyzing the KM2A data during a thunderstorm on June 10, 2021. The number of shower events that meet the trigger conditions increases significantly in atmospheric electric fields, with a maximum fractional increase of 20%. The variations in trigger rates (increases or decreases) were found to be strongly dependent on the primary zenith angle. The flux of secondary particles increased significantly, following a trend similar to that of shower events. To better understand the observed behavior, Monte Carlo simulations were performed with CORSIKA and G4KM2A (a code based on GEANT4). We found that the experimental data (in saturated negative fields) were in good agreement with the simulations, assuming the presence of a uniform electric field of -700 V/cm with a thickness of 1500 m in the atmosphere above the observation level. Due to the acceleration/deceleration by the atmospheric electric field, the number of secondary particles with energy above the detector threshold was modified, resulting in the changes in shower detection rate.

为了精确预报煤矿井下硫化氢含量,防止硫化氢含量超标带来的危害,基于可调谐半导体激光吸收光谱技术,设计研制了一种便携式硫化氢检测仪.该仪器采用中心波长为1590 nm的分布式反馈激光器,结合多次反射的郝里奥特长光程气体吸收池,可以满足煤矿井下0～200 mg/L硫化氢的实时检测.离线标定和实验室测试得到检测仪测量的相对误差为±2％,最快响应时间为0.5 s;通过实验室测量六盘水大湾煤矿120205采煤工作面上隅角和采空区的气体成分,结果表明,便携式硫化氢检测仪稳定可靠,能够满足煤矿井下硫化氢预警的要求.

Due to the Bernoulli effect, the directional flow of water molecules on one side of the nanopore will produce a pressure drop compared with the fluid on the other side, which makes the water molecules on the static brine side be pumped through the slit with salt ions being blocked. A high water flux of 857 L/m2/h??bar with 100% salt rejection rate can be obtained in a single-layer graphene membrane with the slit of 0.7 nm under an external pressure of 250 MPa. This work provides a novel desalination method and a useful guideline for the future development of new pumping systems that separate ions or molecules.

Introduction One of main scientific goals of the Large High Altitude Air Shower Observatory (LHAASO) is to accurately measure the energy spectra of different cosmic ray compositions around the 'knee' region. The Wide Field-of-View (FoV) Cherenkov Telescope Array (WFCTA), which is one of the main detectors of LHAASO and has 18 telescopes, is built to achieve this goal. Multiple telescopes are put together and point to connected directions for a larger FoV. Method Telescopes are deployed spatially as close as possible, but due to their own size, the distance between two adjacent telescopes is about 10 m. Therefore, the Cherenkov lateral distribution and the parallax between the two telescopes should be considered in the event building process for images crossing over the boundaries of FoVs of the telescopes. An event building method for Cherenkov images measured by multiple telescopes of WFCTA is developed. The performance of the shower measurements using the combined images is evaluated by comparing with showers that are fully contained by a virtual telescope in simulation. Results and conclusion It is proved that the developed event building process can help to increase the FoV of WFCTA by 30% while maintaining the same reconstruction quality, compared to the separate telescope reconstruction method.

Desalination through reverse osmosis (RO) membrane is one of the most popular way. However, conventional RO membranes meet a trade-off between salt rejection and water flux which limit their comprehensive performance. In this work, Sulfonated Zirconium (IV)- carboxylate metal-organic framework (MOF) material UiO-66-SO3H was successfully synthesized, and thin film nanocomposite (TFN) with UiO-66-X (-H/-NH2/-SO3H) incorporated polyamide (PA) layer were fabricated. Angstrom-sized UiO-66-X ion transport channels with different functional groups in TFN membranes change the membrane morphology and chemistry, accelerate the penetration of water molecules while maintaining the high ion screening effect. As a result, comparing to the pristine TFC membrane, the optimized TFN-UiO-66-SO3H membrane shows an increase of water molecules permeability to 347% and still maintained a salt rejection with ~94.7% under 2000 ppm NaCl solution with reverse osmosis (RO) mode, leading to a great improvement of intrinsic separation properties. The improved performance was owing to the size exclusion effect and hydrophilic nature of UiO-66-SO3H particles. What's more, the additional water migration channels through the incorporated UiO-66-SO3H nanoparticles lead to a boosting water permeation. To our best knowledge, it is the first time to make investigation in sulfonated UiO-66-SO3H incorporated TFN membrane for desalination.

Hypothesis: Structured hydrophobic surfaces often suffer from Cassie-wetting failure due to trapped water in structure gaps for a long-term operation. Sustainable Cassie-wetting on such surface could be achieved by coating an atom-thick and moisture-impermeable graphene on it.Experiments: Water contact angles were measured to clarify the effect of graphene on wetting, and water impermeability was verified by moisture deposition and evaporation. Sliding angle measurements and vapor condensation were carried out to demonstrate the stable Cassie-state wetting and application. Findings: Interestingly we found the graphene does not significantly disrupt the wetting behavior of the structured hydrophobic surface, showing a wettability transparency. Moreover, the impermeability of graphene keeps moisture away from the structure gaps. Owning to the combination of these two properties, droplets on the graphene-coated structured surface exhibit a stable Cassie-state hydrophobic wetting, even under the situation of moisture deposition and evaporation. Using the modified surface, we also found a 40-100% increase in condensation efficiency for a 5-hour vapor condensation at a subcooling of 40 degrees C. These results suggest an effective strategy to prevent Cassie-wetting failure of structured hydrophobic surface and are expected to promote its further application in more complex conditions.(c) 2022 Elsevier Inc. All rights reserved.

In the Large High Altitude Air Shower Observatory (LHAASO), one square kilometer array (KM2A), with 5242 electromagnetic particle detectors (EDs) and 1171 muon detectors (MDs), is designed to study ultra-high energy gamma-ray astronomy and cosmic ray physics. The remoteness and numerous detectors extremely demand a robust and automatic calibration procedure. In this paper, a self-calibration method which relies on the measurement of charged particles within the extensive air showers is proposed. The method is fully validated by Monte Carlo simulation and successfully applied in a KM2A prototype array experiment. Experimental results show that the self-calibration method can be used to determine the detector time offset constants at the sub-nanosecond level and the number density of particles collected by each ED with an accuracy of a few percents, which are adequate to meet the physical requirements of LHAASO experiment. This software calibration also offers an ideal method to realtime monitor the detector performances for next generation ground-based EAS experiments covering an area above square kilometers scale.