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Traditionally, domestic induction heating (IH) is designed to heat the ferromagnetic (FM) pan. However, it is incompetent to heat the non-ferromagnetic (NFM) pan since the small equivalent resistance of the pan will easily result in the overcurrent on the inverter. Inspired by the compensation network in the wireless power transfer (WPT), the series-parallel resonance (SPR) network with a relay switch is newly integrated into the IH technology to develop a dual-resonant topology-reconfigurable inverter for all-metal IH. The proposed system can be purposely configured to a half-bridge series resonant inverter with the pulse width modulation (PWM) to heat the FM pan, or a full-bridge SPR-based inverter with the phase shift control (PSC) to heat the NFM pan, respectively. Moreover, the output-input current gain of the SPR network equals the heating-coil quality factor, thereby readily eliminate the overcurrent issue of the inverter. For exemplification, a 1 kW prototype has been built with system efficiencies of 94.32% and 91.05% for heating FM and NFM pans, respectively. Finally, the proposed system can be evolved to achieve automatic load detection and impedance matching to ensure uninterrupted resonance. Both calculated and measured results are given to validate the flexibility and feasibility of the proposed system.

To improve the heat transfer efficiency of the reactor fuel assembly, it is necessary to accurately calculate the two-phase flow boiling characteristics and the critical heat flux (CHF) in the fuel assembly. In this paper, a Eulerian two-fluid model combined with the extended wall boiling model was used to numerically simulate the 5 × 5 fuel rod bundle with spacer grids (four sets of mixing vane grids and four sets of simple support grids without mixing vanes). We calculated and analyzed 11 experimental conditions under different pressure, inlet temperature, and mass flux. After comparing the CHF and the location of departure from the nucleate boiling obtained by the numerical simulation with the experimental results, we confirmed the reliability of computational fluid dynamic analysis for the prediction of the CHF of the rod bundle and the boiling characteristics of the two-phase flow. Subsequently, we analyzed the influence of the spacer grid and mixing vanes on the void fraction, liquid temperature, and secondary flow distribution. The research in this article provides theoretical support for the design of fuel assemblies.

A novel self-healing coating with photothermal and pH dual-responsive properties has been designed to protect carbon steel against corrosion by loading the stimuli-responsive microcapsules into a shape memory epoxy coating. The sandwich-like microcapsules were based on reduced graphene oxide/mesoporous silica (rGO@MS) assembled with a pH-responsive poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) layer, and were loaded with benzotriazole (BTA) inhibitors (abbreviated as rGO@MS-P-BTA). Under near-infrared (NIR) light irradiation, the prominent photothermal effect of rGO could not only elevate the coating temperature to activate the shape memory effect and close the coating scratch, but also facilitate the release of corrosion inhibitors to suppress the corrosion activity. Moreover, the PDMAEMA as a pH-driven “gatekeeper” realized the controlled release of BTA from microcapsules at acid conditions. The surface morphology analysis, electrochemical impedance spectroscopy (EIS), and scanning electrochemical microscopy (SECM) were performed to evaluate the self-healing performance of the composite coatings. The results showed that the combination of NIR light and pH-responsive self-healing effects endowed the coating with short healing time and prominent healing efficiency.

In this work, a highly active CeO2 catalyst with hollow nanosphere morphology for low temperature NOx storage was prepared by a surfactant-assisted solvothermal reaction. The physicochemical properties of ceria samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption–desorption, H2-temperature programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS) and in situ diffused reflectance infrared Fourier transform spectroscopy (DRIFTS). The as-prepared CeO2nanosphere possesses excellent NO oxidation capacity, smaller mesopores, better reducibility, more surface Ce3+ content. Compared with CeO2 with nanorod and nanoparticle morphologies, CeO2 nanosphere shows better intrinsic low temperature NOx trapping performance, with a wide operating temperature window (150–300 °C), high NOx adsorption capacity (NAC, 640–745 μmol/g) and high NOx storage capacity (NSC, 250–350 μmol/g). Two reaction pathways are speculated for NOx adsorption on CeO2 nanosphere, including “nitrate route” and “nitrite route”. The thermally unstable surface nitrites formed on the CeO2 nanosphere allow ceria to release more NOx during the desorption process. The present work provides a new ceria morphology for NOx traps, which may become a potential excellent NOx storage material.

The increasingly severe electromagnetic microwave pollution raises higher requirements for the development of efficient microwave absorption (MA) materials. Metal sulfides are regarded as potential robust MA materials because of their unique optical, thermal, electrical, and magnetic properties, as well as the controllable microstructures. However, due to the limited MA performances of unary metal sulfides, morphology regulations and foreign materials hybridizations are adopted as effective strategies to improve their MA performances. Recent years witnessed the fast research progresses on the metal sulfides based MA materials and thus, a systematic literature survey on the materials design, fabrication, characterizations, MA behaviors, and the mechanisms behind is, highly desirable to summarize the rapid progress of this hot research area so as to provide guidance for the future development trend. This review firstly reviewed the research background, research progress, and basic principles of MA materials. Subsequently, the present synthetic methods and performance improvement strategies of metal sulfides based MA materials are systematically introduced. Then, by comparing the MA properties of one-dimensional, two-dimensional, and three-dimensional metal sulfides based composites, the influence of dimensionality and morphology on the MA properties are analyzed. By summarizing the research process of metal sulfides/dielectrics composites, metal sulfides/magnets composites, and metal sulfides/dielectrics/magnets composites MA materials, the influence of foreign materials hybridizations on the loss mechanisms and impedance matching conditions of metal sulfides based composites are revealed. Finally, the challenges and development prospects of metal sulfides based MA materials are presented. This review would provide a comprehensive understanding and insightful guidance for the exploration and development of efficient MA materials with thin thickness, light weight, wide absorption bandwidth, and strong absorption intensity.

In this work, we establish a comprehensive spectral model to realize effective design of high-power ytterbium-Raman fiber amplifiers (YRFAs) employing different types of Raman-pump lasers, and propose an intuitive approach for the optimization of high-power YRFAs. Quantitative comparisons with the experimental results are given in two high-power YRFAs employing Raman-pump lasers with different spectral linewidth. The consistency of measured and simulated power ratios and spectral properties of different components in the two YRFAs confirms the fidelity of the spectral model. Further theoretical analysis reveals that the impact of Raman-pump lasers on YRFAs is mainly determined by the relative intensity noise (RIN) of Raman-pump lasers up to the cutoff frequency of the pump RIN transfer function of the YRFA. Notably, the RIN of Raman-pump lasers could provide a well reference for the superior design of Raman-pump lasers in high-power YRFAs.

Nano-zirconia has been widely applied due to its excellent physical and chemical properties (e.g., high strength, corrosion resistance, oxygen ion conductivity). Existing preparation methods of nano-zirconia tend to require long reaction time, and the sizes of final particles are large with uneven distributions. Sub-/supercritical hydrothermal synthesis of nanoparticles is favored by researchers owing to controllable reaction process, uniform particle size distribution, good reproducibility, short reaction time, high conversion rate and harmlessness to environment. In this paper, the characteristics and mechanisms of dissolution, crystallization and growth of nano-zirconia during sub-/supercritical hydrothermal synthesis are systematically reviewed. The influences of process and material parameters on the size and purity of particles are analyzed. Then, the reaction mechanism and product phase transition mechanism during hydrothermal synthesis of zirconia are summarized to provide a theoretical reference for the oriented preparation. Finally, the improvement and commercialization of sub-/supercritical hydrothermal synthesis technology are evaluated, and the future research topics are proposed.

Balancing charge generation and low energy loss (Eloss), especially in the wide spectral absorption region is critical to obtain high-performance organic photovoltaics (OPVs). Therefore, Y11-M and Y11-EB are designed and synthesized through modifying alkyl chains on different nitrogen aromatic rings of the reported non-fullerene acceptor Y11. Although all the molecules have almost similar low band-gap (around 1.30 eV), Y11-M and Y11-EB exhibit wider absorption in 410–870 nm region. Eventually, the conventional devices based on Y11-M and Y11-EB possess more efficient charge generation with low Eloss (around 0.44 eV). In addition, outstanding efficiencies of 16.64% and 17.15% with the fill factor of 76.15% and 74.73% are obtained in PM6:Y11-M and PM6:Y11-EB-based devices, both higher than Y11:PM6. The results highlight the importance of rational alkyl chains optimization, and a good structure-property relationship is established as well.

Digital light processing (DLP) is one of the most important additive manufacture technologies to fabricate ceramic parts with complex geometries. Compared with pure photosensitive resin, the cure performance of ceramic suspensions is obviously different due to the optical property change after the addition of ceramic powders. In this paper, a unique oxidation process was used to modify the optical properties of nitride powders including AlN and Si3N4. The properties of oxidized ceramics were investigated and the cure performance of ceramic suspensions was then characterized. The effect of oxidation time on cure performance was evaluated. The results showed that for AlN, oxidation process leads to the smaller cure depth and smaller excess cure width as compared with non-oxidized AlN and for Si3N4, oxidation process leads to the larger cure depth and larger excess cure width as compared with non-oxidized Si3N4, indicating that both refractive index and light absorbance of ceramic powders have obvious effects on cure behaviors. Additionally, the cure behavior of oxidized ceramic suspension in this study shows that the relationship of cure depth vs. incident energy agrees well with Beer- Lambert model, but the excess cure width vs. incident energy is not consistent with quasi Beer-Lambert model due to the nature of digital micromirror device (DMD).

Controlled synthesis of noble metal nanoparticles with well-defined size and good dispersion on supports has been a long-standing challenge in heterogeneous catalysis. Here we report a facile photo-assisted H2 in situ reduction process to synthesize monodispersed Pd nanoparticles with 2–4 nm size on photo-insensitive Sm2O3 rare-earth metal oxide with nanorod morphology. Thanks to the contribution of UV irradiation, the photoelectrons generation in the Sm2O3 support accelerates the H2 reduction of Pd2+ ions into Pd0 and stabilize the growth of very small Pd nanoparticles homogeneously dispersed on the support. The homogeneous distribution of the Pd NPs on the surface of Sm2O3 is most likely attributed to the profuse nucleation sites created by the UV irradiation and the abundance of hydroxyl groups on the support. The hydrogenation of styrene to ethylbenzene was studied as a model reaction. As a result, the UV radiated sample shows an excellent TOF value of 7419 h−1, which is quadruple of the sample without UV irradiation, under the condition of 0.1 MPa H2 at a content of 1.0 wt% Pd. Besides, UV radiated sample shows a negligible performance degradation during the repeated cycling process. This photo-promoted H2 reduction process provides a convenient and straightforward route for assembling materials with novel structures and functions for nanotechnology applications.

The electrosynthesis of valuable chemicals via carbon dioxide reduction reaction (CO2RR) has provided a promising way to address global energy and sustainability problems. However, the selectivity and activity of deep-reduction products (DRPs) still remain as big challenges. Here, a copper–carbon-based catalyst with a hydrophobic core–shell architecture has been constructed and was found to exhibit excellent DRPs of methane generation with a faradaic efficiency of 81 ± 3% in a neutral medium and a maximum partial current density of −434 mA cm−2 in a flow cell configuration, which is among the best of CO2-to-CH4 electrocatalysts. Density functional theory calculations suggest that the hydrophobic structure decreasing the water coverage on the catalyst surface can promote the protonation of the *CO intermediate and block CO production, further favoring the generation of methane. These results provide a new insight into the electrosynthesis of DRPs via constructing a hydrophobic core–shell architecture for tuning the surface water coverage.

International audience; The isoelectronic doping of dichalcogenolato nanoclusters of the type [Ag-21{E2P(OR)(2)}(12)](+) (E = S, Se) by any heteroatom belonging to groups 9-12 was systematically investigated using DFT calculations. Although they can differ in their global structure, all of these species have the same M@M-12-centered icosahedral core. In any case, the different structure types are all very close in energy. In all of them, three different alloying sites can be identified (central, icosahedral, peripheral) and calculations allowed the trends in heteroatom site occupation preference across the group 9-12 family to be revealed. These trends are supported by complementary experimental results. They were rationalized on the basis of electronegativity, potential involvement in the bonding of valence d-orbitals and atom size. TD-DFT calculations showed that the effect of doping on optical properties is sizable and this should stimulate research on the modulation of luminescence properties in the dithiolato and diseleno families of complexes.

Severe leakage electromagnetic field (EMF) generated by automatic guided vehicle wireless power transfer (WPT) systems is hazardous to the surrounding objects. To reduce the leakage EMF, a novel compact magnetic coupler is proposed in this paper. The idea of this work is, firstly, adopting the compensation inductors of the LCC-LCC compensated WPT system as EMF canceling coils, and EMF alleviation can be achieved without any additional components; secondly, integrating the power transfer coils and the EMF canceling coil into one magnetic coupler to compact the system. An experimental prototype is fabricated to verify the EMF shielding effect of the proposed magnetic coupler. Experimental results show that compared with that of the general magnetic coupler, the EMF of the proposed magnetic coupler is dramatically reduced by 82.24% at maximum and by 75.18% on average from y=200mm to 350mm. Besides, the transfer efficiency is decreased by 0.32% only with the same output power. That means the proposed magnetic coupler can effectively alleviate the EMF without a significant negative impact on the transfer efficiency.

Thermoelectric devices enable direct conversion between thermal and electrical energy. Recent studies have indicated that the thin film/substrate heterostructure is effective in achieving high thermoelectric performance via decoupling the Seebeck coefficient and electrical conductivity otherwise adversely inter-dependent in homogenous bulk materials. However, the mechanism underlying the thin film/substrate heterostructure thermoelectricity remains unclear. In addition, the power output of the thin film/substrate heterostructure is limited to the nanowatt scale to date, falling short of the practical application requirement. Here, we fabricated the CrN/SrTiO3−x heterostructures with high thermoelectric output power and outstanding thermal stability. By varying the CrN film thickness and the reduction degree of SrTiO3−x substrate, the optimized power output and the power density have respectively reached 276 μW and 108 mW/cm2 for the 30 nm CrN film on a highly reduced surface of SrTiO3−x under a temperature difference of 300 K. The performance enhancement is attributed to the CrN/SrTiO3−x heterointerface, corroborated by the band bending as revealed by the scanning Kelvin probe microscopy. These results will stimulate further research efforts towards interface thermoelectrics.

Background: Bacterial cellulose (BC) and its derivatives are a rich source of renewable natural ingredients, which are of great significance for biomedical and medical applications but have not yet been fully exploited. BC is a high-purity, biocompatible, and versatile biomaterial that can be used alone or in combination with other ingredients such as polymers and nanoparticles to provide different structural organization and function. This review briefly introduces the research status of BC hydrogels, focusing on the preparation of BC-based composite hydrogels and their applications in the field of biomedicine, particularly the wound dressings, tissue engineering scaffolds, and drug delivery. Methods: By reviewing the most recent literature on this subject, we summarized recent advances in the preparation of BC-based composite hydrogels and their advances in biomedical applications, including wound dressings, tissue engineering, and drug delivery. Results: BC composite hydrogels have broadened the field of application of BC and developed a variety of BC-based biomaterials with excellent properties. BC-based hydrogels have good biocompatibility and broad application prospects in the biomedical field. Conclusion: BC-based composite hydrogels with the advantages of 3D structure, nontoxicity, high purity, and good biocompatibility, have great prospects in the development of sustainable and multifunctional biomaterials for biomedical applications.

Ceramic microspheres have attracted significant attention, while the preparation of hierarchically porous ceramic microspheres with high porosity, good sphericity, and controllable size or shape in a short time remains a challenge. Herein, we developed a highly adaptable methodology for the preparation hierarchically porous ceramic microspheres with high porosity and favorable shape in a short time. The UV-curing assisted molding method combined with the Pickering emulsion method was utilized to prepare hierarchically porous ceramic microspheres. Under the irradiation of a UV-curing lamp (395 nm, 50 W), the Pickering emulsion can be cured within as short as 10 s. The microstructures of the three microspheres with different shapes were characterized by scanning electron microscopes (SEM). The as-prepared microspheres had a high sphericity, the interconnectivity of pores was as high as 54 %, and its porosity was as high as 73.4 % ± 3.0 %, while the density was quite low at ∼ 1.02 g/cm3.

Combined with NMR, core experiment, slim-tube tests, nano-CT and oil composition analysis, the mechanism of CO2 enhanced oil recovery had been studied. CO2 flooding under supercritical state could achieve higher oil recovery. In the process of crude oil displaced by supercritical CO2, the average oil recovery was 46.98% at low displacement pressures and 73.35% at high displacement pressures. The permeability of cores after CO2 flooding was only 28%–64% of those before flooding. As to the expelled oil, the contents of asphaltenes and non-hydrocarbons decreased, and saturated hydrocarbons of above C25 were absent in some samples, indicating that they had been retained in cores as demonstrated by CT and NMR experiments. In slim-tube tests, the heavy components of oil were expelled when the pressure increased to 30 MPa. There was a reasonable bottom hole pressure (BHP) below which the heavy components driven out from the far-well zone would deposit in the near-well zone, and when the pressure was too high, the nonhydrocarbon detention may cause block. The smaller throat and worse physical properties the porous media had, the higher displacement pressure would be required to achieve a good oil displacement efficiency. The increase in displacement pressure or time of interaction between oil and CO2 could effectively enhance oil recovery.

Pyrite (FeS2) is considered a promising anode material for lithium-ion batteries (LIBs) relying on its high theoretical specific capacity and low cost. However, the application of FeS2 as anodes ha...

Although great potential hazards and threats still occur from sulfur mustard, there are no specific medicine or therapy for the intoxication of sulfur mustard. Herein, we have demonstrated a supramolecular approach for the detoxification of the sulfur mustard simulant CEES (4) in vitro and in vivo by carboxylatopillar[5]arene potassium salts (CP[5]AK 1) efficiently based on host-guest interactions. The encapsulation of CEES (4) by the cavity of the pillar[5]arene 2 is driven by C-H···π interactions between CEES (4) and the electron-rich cavity of pillar[5]arene 2, which was investigated by 1H NMR titration, density functional theory studies, and the independent gradient model studies. CEES (4) is degradated to the reactive sulfonium salts quickly in aqueous media, resulting in the alkylation of DNA and proteins. The sulfonium salts can be encapsulated by CP[5]AK 1 efficiently, which accelerates the degradation of the sulfonium salts about 14 times. The cell and animal experiments indicated that the bioactivities of the sulfonium salts are inhibited with the formation of stable host-guest complexes, and CP[5]AK 1 has a good therapeutic effect on the damages caused by CEES (4) at either pre- or post-treatments. Due to the low cytotoxicity and good therapeutic effect, the anionic pillar[5]arenes are expected to be developed as specific antidotes against sulfur mustard (HD).

AlSn20Cu alloy is currently one of the most widely used bearing materials, and its microstructure is the most important indicator in application. In this paper, AlSn20Cu alloy ingots were prepared by two methods: ordinary casting and semi-continuous casting, and deformation and annealing process of the two ingots were studied. Scanning electron microscope (SEM) and Image Pro Plus software were used to observe and analyze the evolution of the microstructure, and the morphological information such as the average grain size and area fraction of the Sn phase was quantitatively characterized. The effects of casting method, deformation temperature, deformation amount and annealing temperature on the morphology of Sn phase were studied in this paper. Compared with ordinary casting, the cooling rate of semi-continuous casting is higher, so the Sn phase is smaller, the casting defects are less, and the deformability of the alloy is better. The AlSn20Cu alloy prepared by ordinary casting has better deformability at about 140 °C, while the AlSn20Cu alloy prepared by semi-continuous casting can be rolled and deformed at room temperature. When the deformation is greater than 40%, after annealing at 250 °C, the average grain size of the Sn phase in the AlSn20Cu alloy prepared by semi-continuous casting is around one hundred square microns and the area fraction is more than 10%, and the Sn phase morphology is better than ordinary casting alloy under any processing conditions.

Traditional foam hydraulic fracturing fluids used guar cross-linking technology. However, major production problems, such as high friction and difficulty to accurately control the cross-linking time, have influenced the large-scale application of cross-linked guar foam fracturing fluids. In this study, we developed a novel non-cross-linked foam fracturing fluid using a series of polymers synthesized with acrylamide and hexadecyl trimethylallyl ammonium chloride as monomers and improved the stability of foam by forming structures in solution through association. The results showed that the hydrophobic groups were the key factors that affect the foam stability, and the hydrolysis degree had a significant effect on the elasticity of the polymer solution. The model association polymer with 0.75% hydrophobic group content and 56% hydrolytic degree was optimal. The stability of our proposed foam was comparable to that of the cross-linked guar gum foam. The adsorption of associating polymers on the gas and water interface resulted in a high-stability foam. Our study demonstrates a new avenue to develop high-stability foams to satisfy the current hydraulic fracturing scheme.

As an ecofriendly and low-cost thermoelectric material, Cu2SnSe3 has recently drawn much attention. In this work, the thermoelectric properties of Cu2SnSe3-based materials have been synergistically...

Hyperbilirubinemia caused severe hepatobiliary diseases with various causes, especially hepatic fibrosis and cirrhosis caused by end-stage hepatitis B and C. Plasma adsorption perfusion (PP) has a tremendous advantage in treating patients with hyperbilirubinemia and liver failure, wherein, a safe and effective adsorbent is the key to filter out bilirubin successfully in PP. In this work, a simple engineering strategy, a new porous polymer adsorption resin ERM-0100 based on the homopolymer predispersion system, is proposed to produce high-performance bilirubin adsorbents. Preliminary experimental results show that ERM-0100 exhibits a large surface area and uniformly porous structure. Experimental results verify that ERM-0100 has high biocompatibility and bilirubin adsorption efficiency (TBIL:35%, direct bilirubin [DBIL]:30%, IBIL:87%) that is significantly higher than most of the reported adsorbents. Animal experiments prove that ERM-0100 has high bilirubin adsorption efficiency and can improve the liver function of animals. The combination of high biocompatibility and high adsorption capacity positions the ERM-0100 as a promising candidate for bilirubin removal.

As most of the known systems are flashtype, long-lasting chemiluminescence (CL) emissions are extremely needed for the application of cold light sources, accurate CL quantitative analysis, and biological mapping. In this work, the flashtype system of luminol was altered to a long lasting CL system just because of the paper substrate. The Cu(II)-based organic complex was loaded on the paper surface, which can trigger luminol-H2O2 to produce a long lasting CL emission for over 30 min. By using 1,10-phenanthroline-2,9-dicarboxylic acid (PDA) as the ligand, a hexacoordinated Cu(II)-based organic complex was synthesized by the simple freeze-drying method. It is interesting that the complex morphology can be controlled by adding different amounts of water in the synthesizing procedure. The complex with a certain size can be definitely trapped in the pores of the cellulose. Then, slow diffusion, which can be attributed to the long lasting CL emission, was produced. With the high catalytic activity of the complex, reactive oxygen species from H2O2 was generated and was responsible for the high CL intensity. By using the paper substrate, the flash-type luminol system can be easily transferred to the long-duration CL system without any extra reagent. This long-lasting emission system was used for hydrogen sulfide detection by the CL imaging method. This paper-based sensor has great potential for CL imaging in the clinical field in the future.

The electrolysis of water for sustainable hydrogen producing is a crucial segment of various emerging clean-energy technologies. However, pursuing an efficient and cheap alternative catalyst to substitute state-of-the-art platinum-group electrocatalysts remains a prerequisite for the commercialization of this technology. Typically, precious-metal-free catalysts have always much lower activities towards hydrogen production than that of Pt-group catalysts. To explore high-performance catalysts, maximally exposed active sites, rapid charge transfer ability and desirable electronic configuration are essentially demanded. Herein, the fundamentals of hydrogen evolution reaction will be briefly described and the main focus will be on the interfacial engineering strategies by means of constructing defect structure, creating heterojunction, phase engineering, lattice strain control, designing hierarchical architecture and doping heteroatoms to effectively proliferate the catalytic active sites, facilitate the electron diffusion and regulate the electronic configuration of numerous transition metals and their nitrides, carbides, sulfides, phosphides as well as oxides, achieving a benchmark performance of platinum-free electrocatalysts for the hydrogen evolution reaction. This review unambiguously offers proof that the conventional cheap and earth-abundant transition metal-based substances can be translated into an active water splitting catalyst by the rational and controllable interfacial designing.

Open-cathode polymer electrolyte fuel cells with compact design have attracted increasing attention in the field of portable energy equipment. This study explores the impacts of different length-width ratios (RL-W) of the cell with the same active area (50 cm2) on cell performance based on various measurements of polarization curves, air velocity profile, and temperature distribution. Results suggest that RL-W has a significant impact on cell performance. Remarkably, a performance improvement of 7% is achieved with the increase of RL-W (4.14–22.40) due to the enhancement of heat and mass transfer ability. The maximum temperature difference at the cathode outlet surface is less than 2 °C when RL-W is 22.40. It is also indicated that the optimum cathode outlet surface temperature is about 48～52 °C. Under the condition of ensuring the structural strength and performance of the cell simultaneously, the appropriate range of RL-W is confirmed as 10–20. The results provide basic data and technical support for the system design and application of open-cathode fuel cells.

In PWR three-dimensional transient coupling calculation software CORCA-K, the nodal Green's function method and diagonal implicit Runge Kutta method are used to solve the spatiotemporal neutron dynamic diffusion equation, and the single-phase closed channel model and one-dimensional cylindrical heat conduction transient model are used to calculate the coolant temperature and fuel temperature. The LMW, NEACRP and PWR MOX/UO2 benchmarks and FangJiaShan (FJS) nuclear power plant (NPP) transient control rod move cases are used to verify the CORCA-K. The effects of burnup, fuel effective temperature and ejection rate on the control rod ejection process of PWR are analyzed. The conclusions are as follows: (1) core relative power and fuel Doppler temperature are in good agreement with the results of benchmark and ADPRES, and the deviation between with the reference results is within 3.0% in LMW and NEACRP benchmarks; 2) the variation trend of FJS NPP core transient parameters is consistent with the results of SMART and ADPRES. And the core relative power is in better agreement with the SMART when weighting coefficient is 0.7. Compared with SMART, the maximum deviation is −5.08% in the rod ejection condition and while −5.09% in the control rod complex movement condition.

Loop heat pipe (LHP) is widely used in high-power electronic cooling as a passive cooling device. In this paper, the LHP system was designed with a flat evaporator and a capillary biporous wick with cupric oxide nanofluids as working fluid in LHP. The capillary biporous wick was sintered by nickel powder and the nanofluids were prepared by a two-step method. The startup tests, variable heat load tests, and performance degradation tests of LHP were conducted respectively and the thermal resistance was further analyzed. The results showed that, compared with distilled water, the maximum heat load increased from 290 W to 310 W and the minimum startup heat load decreased from 40 W to 20 W with nanofluids as working fluid. Both the temperature of the evaporator wall and the thermal resistance were reduced in startup tests. At the heat load of 50 W, the performance improvement was the most noticeable, where the temperature of the evaporator wall was reduced by 12.7 °C, the thermal resistance of the evaporator was reduced by 26.9%, and the thermal resistance of the LHP system was reduced by 17.6%. With a variable heat load ranging from 50 W to 290 W, the response speed of LHP became faster and the temperature fluctuation was smaller. The LHP with nanofluids as working fluid still operated normally and the change of thermal resistance with the varies of heat load had the same tendency as the previous experiment in performance degradation tests of 2 months.

The synthesis of two-dimensional molybdenum disulfide (MoS2) has invoked much research interest in recent years. In this work, chemical vapor deposition (CVD) was employed to grow a novel molybdenum disulfide. The synthesis reaction was operated in an inert gas environment, with the sulfur precursor placed in the upstream zone of a double zone tube furnace, and the molybdenum trioxide (MoO3) precursor placed in a small tube in the downstream zone. A piece of glass was used as the substrate, which was placed beside the small tube. We intentionally built a high concentration of molybdenum precursor above the substrate. The specific morphology hinged highly on the concentration of molybdenum. Abundant molybdenum atoms adsorbed on the edges of the bottom MoS2 and formed defects, which promoted the nucleation of the top layer MoS2 and preferentially grew from the edges. This result provides an innovative method to controllably synthesize novel bilayer molybdenum disulfide by a one-step method of chemical vapor deposition.

Design of efficient catalysts for electrochemical reduction of carbon dioxide (CO2) with high selectivity and activity is of great challenge, but significant for managing the global carbon balance. Herein, a series of three-dimensional (3D) single-atom metals anchored on graphene networks (3D SAM-G) with open-pore structure were successfully mass-produced via a facile in-situ calcination technique assisted by NaCl template. As-obtained 3D SANi-G electrode delivers excellent CO Faradaic efficiency (FE) of >96% in the potential range of −0.6 to −0.9 V versus reversible hydrogen electrode (RHE) and a high current density of 66.27 mA cm−2 at −1.0 V versus RHE, outperforming most of the previously reported catalysts tested in H-type cells. Simulations indicate that enhanced mass transport within the 3D open-pore structure effectively increases the catalytically active sites, which in turn leads to simultaneous enhancement on selectivity and activity of 3D SANi-G toward CO2 electroreduction. The cost-effective synthesis approach together with the microstructure design concept inspires new insights for the development of efficient electrocatalysts.

Being a novel energy storage medium, ice slurry has the advantage of good fluidity, high latent heat and heat transfer efficiency, which has a broad application prospect. In this work, the ice making characteristics of different types of additives (MgCl2, ethylene glycol and magnetic iron oxide nanoparticles) in a binary ice system by vacuum flash evaporation under the action of solid adsorption were experimentally investigated. Subcooling, flash rate, ice packing factor, latent heat and thermal conductivity were measured to evaluate the performance of ice production. The results showed that 0.075% wt of iron oxide nanoparticles and 1% wt of MgCl2 are more suitable to be used as additives for binary ice preparation than ethylene glycol, with the former outperforming the latter. Under optimal conditions, compared with pure water for ice making, the subcooling degree of iron oxide nanofluid was reduced by 55.80%, and the thermal conductivity and ice packing factor were increased by 98.80% and 54.22%, respectively. The subcooling degree of the MgCl2 solution was reduced by 37.52% and the ice packing factor was improved by 59.51%. Meanwhile, DSC tests showed that the latent heat of the nanofluid was almost independent of the nanoparticle concentration. However, the increase of MgCl2 solution would cause the decrease of latent heat. In addition, high concentrations of additives can inhibit ice crystal nucleation and growth, but a certain concentration of additives facilitates ice crystal refinement in vacuum ice making process, which is conducive to the transportation of ice slurry.

Parabolic trough collector (PTC) is the most cost-effective and mature concentrated solar power (CSP) technology for solar thermal utilization. However, the highly concentrated solar irradiation on the bottom of the absorber tube causes high local temperature, thermal stress and deformation, further leading to damage and performance degradation of PTC. In order to alleviate the above problem, a novel parabolic trough receiver (PTR) with ribbed absorber tube is proposed to improve the thermo-mechanical performance of PTC Moreover, the multi-objective optimization is employed to determine the optimal parameter combinations (slant angle ( β ), size (e), pitch (p), and number of the ribs (N)) of ribbed absorber tube coupled with 3D numerical simulation and the genetic algorithm (GA). Based on the TOPSIS method and performance evaluation criteria (PEC) value, the ribbed absorber tube with the optimal geometric parameters of β = 15 ° , N = 6 , e = 4 . 5 mm and p = 20 mm is selected in the Pareto Front as the suggested optimal design. Furthermore, the performance of the PTRs at different inlet temperature of the fluid ( T i n = 400 –600K), direct normal irradiance (DNI=300–1000 W/m2) and mass flow rate (M=0.62–3.72kg/s) are evaluated. It is found that the ribbed absorber tube can effectively disturb the fluid near the boundary and induce longitudinal vortexes flow, which results in significant improvement in heat transfer between fluid and absorber tube, thereby enhancing the performance of the PTC. Compared to the plain tube, the heat transfer and flow resistance of the optimal ribbed absorber are enhanced by 57%–225% and 222%–630%, and the heat loss is lessened by up to 79.3%, resulting in 2.3% and 2.2% improvement in the heat collecting efficiency and overall efficiency. The findings in this paper may provide practical guidelines for developing efficient PTC.

Efficiently utilizing the low-grade heat contributes to improving energy consumption structure and energy utilization efficiency, as well as preventing environmental deterioration. To harvest low-grade heat below 80 °C, advanced adsorption-based osmotic heat engines are constructed, which consist of an adsorption-based desalination module for thermally separating the salt solution into concentrated and diluted streams, and a reverse electrodialysis module for converting produced salinity gradient into electricity. Two different heat recovery configurations are employed to improve the heat-to-electricity performance: one is that the cooling power generated in the evaporator is used to cool the condenser and the other is that evaporator is coupled inside the condenser. The transient responses are analyzed and the effects of adsorption/desorption time, switching time, working concentration and heat source temperature on the heat-to-electricity performance are discussed. The efficiency with respect to Carnot efficiency is also presented to provide information on effectively utilized level of the available exergy. Compared with original configuration, the reduced effective condensing temperature in Configuration I and the pressurization effect in Configuration II significantly elevate the working capacity, thus to boost the work extracted. At lower working concentrations and adsorption times, the electric efficiency can be improved via Configuration II, while at higher working concentrations and adsorption times, the advanced configurations hinder the electrical efficiency. In Configuration II, compared with original configuration, the electric power and efficiency are improved by 68.3% and 15.2%, respectively, at a heat source temperature of 333.15 K with 2 mol/kg NaCl solution. While with 7 mol/kg NaCl solution, the electric power is augmented by 11.8% while the electric efficiency is decreased by 19.8%. This study may contribute to designing advanced adsorption-based osmotic heat engines to achieve an upgraded heat-to-electricity performance.

In this paper, a carboxymethyl cellulose (CMC)/graphene oxide (GO) composite film-coated humidity sensor was proposed based on thin-core fiber Mach-Zehnder interferometer (TCMZI). A segment of thin-core fiber (TCF) was spliced between two segments of single-mode fiber (SMF), and the TCF cladding was first corroded with hydrofluoric acid and then coated with a layer of CMC/GO film via optical driven deposition method. The relative humidity (RH) sensing characteristics of the sensor were experimentally investigated by observing the wavelength shift of resonant dips in the transmission spectrum, which showed that the CMC/GO composite film-coated TCMZI has good repeatability and stability in the measurement of humidity. A maximum average humidity sensitivity of −75.6 pm/%RH was obtained in the RH range of 35%-80%, nearly 2.048 and 3.237 times higher than that of CMC and GO single film coated ones. To the best of our knowledge, this is the first report on using the CMC/GO composite film for humidity measurement, and its excellent performance is expected to be extended to humidity sensitization of more fiber-optic sensors. The proposed sensor has the advantages of simple structure, easy fabrication, low cost, good stability and high performance, which can be applied to the fields of bio-chemical and medicine.

PURPOSE To measure diode sensitivity degradation (DSD) induced by cumulative proton dose delivered to a commercial daily quality assurance (QA) device. METHODS At our institution, six Daily QA 3 (DQA3, Sun Nuclear Corporation, Melbourne, FL, USA) devices have been used for daily proton pencil beam scanning QA in four proton gantry rooms over a span of 4 years. DQA3 diode counts were cross-calibrated using a homogenous field with a known dose of 1 Gy. The DSD rate (ΔR%/100 Gy) was calculated using linear regression on time-series plots of diode counts and an estimate of cumulative dose per year based on the cross-calibration. The effect of DSD on daily QA spot position measurements was quantified by converting DSD to baseline spot position shift. RESULTS The average dose delivered to the four inner DQA3 diodes was 104 ± 5 Gy/year, and the rate of DSD was -5.1% ± 1.0/100 Gy with the exception of one DQA3 device that had a significantly higher rate of DSD (-12%/100 Gy). The R2 s of the linear fit to time-series plots were between 0.92 and 0.98. The DSD rates were not constant but decreases with accumulated doses. The four center diodes, which received 40% of the cumulative dose received by inner diodes, had a DSD rate of -7.2% ± 0.9/100 Gy. For our daily QA program, 1 year of DSD was equivalent to a 0.2 mm shift in spot position. CONCLUSIONS The DSD rate of DQA3 diodes determined by long-term proton daily QA data was about -5%/100 Gy, which is more than 10 times greater than the reported DSD rate from photon irradiation. DQA3 diodes may be used for daily proton QA programs, provided that they are recalibrated at an appropriate frequency that should be determined specifically for different daily QA programs.

Detection and remediation of radioactive components have become the focus of worldwide research interest due to the ever-increasing generation of nuclear waste and the concerns on nuclear accidents. Among the numerous radionuclides, uranium and its isotopes receive the most attention because of their high proportion in nuclear waste and long half-life. Herein, a highly luminescent terbium-organic framework, formulated as [Tb4(C29O8H17)2(NO3)4(DMF)4(H2O)4]·4H2O·8.5DMF (YTU-100), with exceptional sensitivity and selectivity toward uranium was successfully prepared. The material exhibits fast adsorption kinetics and moderate sorption capacity. Interestingly, the luminescence intensity variation highly correlates to the amount of adsorbed uranium, which results in a quantitative, accurate, and selective uranium detection manner. The detection limits in deionized water and tap water were determined to be 1.07 and 0.75 ppb, respectively, which are lower than the US Environmental Protection Agency standard of the maximum contamination of uranium in drinking water. YTU-100 offers an alternative approach for building multifunctional MOFs used for simultaneous detection and removal of uranium from aqueous solutions.

Quartz crystal microbalance (QCM) is one of the powerful tools for the studies of molecular recognition and chiral discrimination. Its efficiency mainly relies on the design of the functional sensitive layer on the electrode surface. However, the organic sensitive layer may easily cause dissipation of oscillation or detachment and weaken the signal transfer during the molecular recognition processes. In this work, we reveal for the first time that the bare metal surface without the organic selector layer has the capability for chiral recognition in the QCM system. During the adsorption of various chiral amino acids, relatively higher selectivity of D-enantiomers on gold (Au) surface was shown by the QCM detection. Based on analyses of the surface crystalline structure and density functional theory calculations, we demonstrate that the chiral nature of Au surface plays an important role in the selective binding of specific D-amino acids. These results may open new insights on chiral detection by QCM system. It will also promote the construction of novel chiral sensing systems with both efficient detection and separation capability.

Recently, a new layered-ternary compound V2SnC was successfully synthesised by reacting V, Sn, and C powder mixture at 1000°C. Its space group was identified as P63/mmc. In this work, the structura...

With many advantages including superior color saturation and efficiency, quantum dot light-emitting diodes (QLEDs) are considered a promising candidate for the next-generation displays. Emission uniformity over the entire device area is a critical factor to the overall performance and reliability of QLEDs. In this work, we performed a thorough study on the origin of dark spots commonly observed in operating QLEDs and developed a strategy to eliminate these defects. Using advanced cross section fabrication and imaging techniques, we discovered the occurrence of voids in the organic hole transport layer and directly correlated them to the observed emission nonuniformity. Further investigations revealed that these voids are thermal damages induced during the subsequent thermal deposition of other functional layers and can act as leakage paths in the device. By inserting a thermo-tolerant 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile (HATCN) interlayer with an optimized thickness, the thermally induced dark spots can be completely suppressed, leading to a current efficiency increase by 18%. We further demonstrated that such a thermal passivation strategy can work universally for various types of organic layers with low thermal stability. Our findings here provide important guidance in enhancing the performances and reliability of QLEDs and also other sandwich-structured devices via the passivation of heat-sensitive layers.