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In this paper, we study the data analysis and calculation of the factors influencing the preparation of C4 olefins by ethanol coupling. Specifically, by combining each catalyst, the relationship between temperature and ethanol conversion and C4 olefin selectivity was analyzed by regression analysis and correlation analysis, respectively. In addition, the grey relational degree analysis was used to solve the grey relational degree between the influencing factors of the experiment. The nonlinear correspondence between ethanol conversion and C4 olefin selectivity with different catalyst combinations and temperatures was evaluated by means of random forest model and BP neural network model. Finally, we build a support vector machine regression (SVMR) model and optimize the cost and gamma parameters of this model using a genetic algorithm.

Metal-organic frameworks (MOFs) derivatives have been widely explored as highly efficient electromagnetic absorbing materials. Due to their diverse coordination arrangements, morphologies, and unique structures, MOFs provide promising avenues for synthesizing materials with customized properties. However, strategies for tailoring properties of low-dimensional MOFs-derived absorbers with hollow structures remain a considerable challenge. Herein, a well-defined Co@N-doped porous carbon composite (Co/N PC) with double-shell hollow structures has been successfully developed through self-templating-polymerization and subsequent pyrolysis. The proposed strategy for the synthesis of hollow architecture involves three simple steps (i) coordination, (ii) dissociation, and (iii) dopamine (DA) polymerization. The synthetic approach is realized at room temperature without a need for solvent etching. By effectively optimizing parameters including void thickness, surface structures, and graphitization levels, the as-designed Co/N PC composites feature wide absorption bandwidth of 5.93 GHz at a thickness of 2.4 mm with a filler loading of 15 wt%. The exceptional performance of microwave absorption (MA) is primarily achieved through excellent dielectric loss, and enhanced impedance matching, due to increased conductive loss through porous hollow structures and dipolar/interfacial polarization. This work provides an eco-friendly and facile route to designing hollow MOFs derivatives, offering substantial parameter space for optimized future lightweight and efficient absorbing materials.

The engineering of core-shell nanostructures provides a great potential to induce interfacial polarization relaxation and optimize impedance matching. Herein, core-shell-structured MHCS@MoS2 nanospheres are developed using hollow carbon (MHCS) and stacked MoS2 nanosheets. Heterostructures between cores and shells significantly boost the interface polarization effect and effectively reduce the electromagnetic wave (EMW) reflection caused by highly conductive MHCS. Thereby, efficient and broadband electromagnetic microwave absorption (EMA) performance can be achieved. Through controlling the thickness of MoS2 shells and the graphitization of MHCS cores, the effective absorption bandwidth (fE) of MHCS@MoS2 can reach 6.21 GHz at the thickness of only 2.1 mm. The nanodesigned core-shell-shaped MHCS@MoS2 nanospheres are demonstrated as a promising high-performance EMA material.

As a typical fascinating microstructure, the core-shell structure provides abundant possibility for material design in various fields including nano-engineering. In addition, the popular MOF derivatives have been widely explored and recognized as the most potential candidates for functional materials, especially in the field of microwave absorption (MA). Combined with the advantages of their structure and function, it is expected to maximize the synergistic effect and achieve amazing MA performance. In this paper, a series of core-shell CF@C/Co composites were assembled by using lightweight and conductive CF as the core and cubic ZIF-67-derived C/Co with controllable structure and adjustable graphitization as the shell. The intrinsic relationships between shell structure, component content, graphitization degree, electromagnetic parameters and various microwave loss behaviors are analyzed. After properly adjusting the degree of graphitization on the basis of derivation of various C/Co shells, A3-600 with obvious multi-polarization effect were obtained. A3-600 achieves an effective absorption bandwidth of 6.25 GHz at 1.71 mm and the best reflection loss of −71.95 dB at 1.78 mm. This dual strategy of shell evolution design and graphitization control has been proved to be an effective method to coordinate electromagnetic matching and construct multi-polarization effect to enhance the performance of MA.

Luminescent solar concentrators (LSCs) can be used as large-area sunlight collectors, which show great potential in the application of building-integrated photovoltaic areas. Achieving highly efficient LSCs requires the suppression of reabsorption losses while maintaining a high photoluminescence quantum yield (PLQY) and broad absorption. Perovskites as the superstar fluorophores have recently emerged as candidates for large-area LSCs. However, highly emissive perovskites with a large Stokes shift and broad absorption have not been obtained up to now. Here, we devised a facile synthetic route to obtain Mn-doped multiple quantum well (MQW) Br-based perovskites. The Br-based perovskite host ensures broad absorption. Efficient energy transfer from the exciton to the Mn dopant produces a large Stokes shift and high PLQY simultaneously. By further coating the perovskites with Al

The combination of Ag nanomaterials and special nanostructures can significantly amplify the conversion of electromagnetic energy, especially in microwave absorption applications. Herein, a kind of...

The micro-morphology design of nanomaterials has always been a hot issue in the field of microwave absorption. In this work, multi-shell structure is made on the basis of hollow structure and porous structure, and the effect of shell number of nanoparticles on microwave absorption properties is studied. Multi-shell hollow porous carbon nanoparticles (HPCNs-m) were prepared by simple liquid phase method combined with layer-by-layer process, and their micro-morphology, chemical structure, electromagnetic properties and microwave absorption properties were studied by a variety of characterization methods. The results show that the multi-shell structure is beneficial to improve the conductivity loss and polarization loss, so as to enhance the microwave absorption properties of the samples. In all samples, the effective absorption bandwidth (EAB) of three-shell hollow porous carbon nanoparticles (HPCNs-3) is 5.17 GHz under the thickness of 1.6 mm, and the best reflection loss (RL) is −18.13 dB at 14.66 GHz. This work expands the study of the effect of the number of shells on microwave absorption properties, and provides a useful reference for the design of microwave absorbers.

Metal halide perovskites have been extensively studied recently by virtue of their extraordinary luminescence characteristics. However, they still suffer from severe stability issues, and contain a toxic metal lead. Here, single crystals of (PEA)4Cu4I4, a lead-free orange-red-emitting organic–inorganic copper-halide compound with a photoluminescence quantum yield (PLQY) of 68%, were synthesized via a simple solvent vapor diffusion process with commercially-available phenylethylamine (PEA) as a ligand. The crystals show superior stability to perovskites with retaining 60% of their initial photoluminescence (PL) intensity after 60 days in water, which is due to the hydrophobic nature of PEA and the stable Cu–N bonds. Phase transition is found to take place upon lowering the temperature, which causes a redshift of the PL peak. The emission band is identified to be associated with triplet cluster-centered (CC) excited states because of their shortened Cu–Cu distances, excitation-independent PL and long PL lifetime. In addition, micron-sized oleic acid capped (PEA)4Cu4I4 particles were developed by a hot-injection method, and they possess similar stability to that of bulk crystals. A monochrome LED was further fabricated by employing the as-prepared micron-sized particles as phosphors, demonstrating their potential for optoelectronic applications.

MOFs with high tunability are considered ideal candidates as microwave-absorbing materials. Strict experimental conditions can ensure the repeatability and maximize the potential of such materials. In this study, cubic ZIF-67 carbides synthesized at different solution temperatures showed an adjustable average size, and then by adjusting the calcination temperature we could control the degree of graphitization, so as to explore the synergistic effect of these two aspects to achieve an in-depth understanding of the electromagnetic properties and microwave absorption properties. The results showed that sample 30-600 (with the former number referring to the synthesis temperature and the latter to the calcination temperature) showed the widest effective absorption bandwidth (5.75 GHz, 1.8 mm) and the optimal reflection loss (-56.92 dB, 2.1 mm). The best matching electromagnetic parameters were obtained under the synergistic action of a smaller particle size and appropriate degree of graphitization, so as to achieve strong attenuation characteristics under low electromagnetic wave reflection. The microwave loss mechanism of the sample mainly involved dielectric losses, such as from conductance loss, dipole polarization, and interface polarization. Starting from the experimental details, this work proposes a dual control strategy for developing microwave-absorbing materials with both simplicity and practicability, which provides a useful reference for other microwave absorbents synthesized at room temperature.

Fingerprints form when fingers touch a solid surfaceand are considered the best way for individual identification. However, the current latent fingerprint (LFP) developing methods cannot meet the demand for high sensitivity and being convenient and healthy. Herein, bifunctional Fe3O4@SiO2-CsPbBr3 powders have been designed and fabricated and exhibit good magnetic and strong fluorescent properties. The magnetism of Fe3O4 can avoid dust flying, while the fluorescence of CsPbBr3 ensures the high definition of LFPs. Clear fingerprints have been detected on various solid substrates using the Fe3O4@SiO2-CsPbBr3 powders instead of eikonogen. Detailed characterization studies suggest that the ammonium cationic groups on the surface of nanoparticles (NPs) have strong adhesive interactions with the residues of fingerprints because of the electrostatic attraction between them. Therefore, the convenient operation and excellent resolution offer great opportunity in the practical application of fingerprint detection and other areas.

Previous studies have raised concerns that kidney disease is often closely related to low serum Se levels in patients and that hyposelenemia may increase the vulnerability of patients to complications. However, few studies examining renal injury caused by Se deficiency have been conducted. To determine the effects of a selenium-deficient diet on renal function, a mouse model was fed a selenium-deficient diet (0.02 mg Se/kg) for 20 weeks. Meanwhile, mice in the control group (selenium-adequate) were fed a standard diet (0.18 mg Se/kg). The cellular models were established by lentiviral Trnau1ap-shRNA vectors transfected into mouse podocyte (MPC5) and mouse renal tubular epithelial (TCMK1) cell lines. Significant increases in serum creatinine levels and urinary protein/creatinine ratios were accompanied by increased MDA content in the Se-deficient group compared to the control group. The morphological observations of tissues showed widespread inflammation and ultrastructural changes in the Se-deficient group, such as swollen mitochondria and extensive podocyte fusion and renal tubular microvilli shedding. In addition, the expression of COXIV and cytochrome c was significantly downregulated in the Se-deficient group. Importantly, the mRNA levels of silent mating type information regulation 2 homolog 1 (SIRT1) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and the protein levels of SIRT1 were increased in the Se-deficient group compared with the normal control group. Our data indicate that Se deficiency induces renal injury in mice. The elevated oxidative stress caused by Se deficiency may result in mitochondrial damage, which might affect renal function. Moreover, the SIRT1/PGC1α axis likely plays an important role in the compensatory mechanism of mitochondrial dysfunction.

Magnetoelectric coupling is a key strategy to obtain high-performance microwave absorption materials. Especially for carbon matrix composites, the absorbing capacity can be optimized via the tuning of the graphitization degree and the content ratio of the magnetic and dielectric components. Based on this theory, a simple strategy, consisting of the solvothermal method and annealing in an inert atmosphere, is adopted in this study to combine CoNi magnetic alloys with graphitized carbon into micron-scale composite spherical particles. Additionally, special attention is paid to the correlation among the graphitization degree of carbon matrix, component proportion, and dielectric response ability, so as to achieve a flexible micromorphology design and a tunable microwave absorption performance. When the pyrolysis temperature is offset to the best of 700 ℃, a broadband absorption of 6.61 GHz (reflection loss - 10 dB) is achieved at an ultrathin matching thickness of 1.9 mm. Adjusting the carbon content can further optimize the impedance matching and realize a high-intensity absorption with a reflection loss of - 72.7 dB. Our work proposes a useful strategy to realize the effective combination of the magnetic and dielectric loss mechanisms and boost the microwave absorption capacity toward achieving the desired broadband and a high-efficiency absorption performance.

The orthorhombic O and O′ structure phases of ABO3-type perovskites possess the same symmetry and quite different physical properties. In this work, a pressure induced isostructural O′–O phase transition with volume expansion and less distortion in DyFeO3 orthoferrite was experimentally observed and studied by high-pressure x-ray diffraction and Raman spectroscopy measurements. Up to 35.2 GPa, DyFeO3 crystallizes in an orthorhombic Pbnm symmetry structure. With no change in the symmetry group, distinct O′-phase and O-phase were verified below 13.1 GPa and above 15.1 GPa, respectively. Meanwhile, the lattice becomes less distorted and metrically pseudo-cubic on the high-pressure side. The cell volume expands by a step in the intermediate pressure window accompanied by a decrease in spontaneous strain. It is suggested that FeO6 octahedra are more compressible than DyO12 sites under pressure. This work claimed the physical mechanism underlying phonon dynamics and variation of local structure symmetry of DyFeO3, which can be considered as the basic view for RFeO3 perovskites.

Luminescent solar concentrators (LSCs) show great promise in reducing the cost of silicon solar cells due to their potential use for high-efficiency energy harvesting. Compared to narrow absorption organic dyes, quantum dots (QDs) are a favorable approach to acquire stable LSCs. However, the use of toxic heavy metals in QDs and the small Stokes shift largely restrict their development. Here, a toxic metal-free, highly luminescent ink based on a copper(I)-halide hybrid cluster is reported, whose quantum yield (QY) exceeds 68%. Under the interaction with halohydrocarbon, CuI and phenethylamine (PEA) can be easily dissolved and the ink can be facilely acquired. The obtained film exhibits strong orange light emission with a large Stokes shift. As a proof-of-concept experiment, (PEA)

Doping Mn2+ into CsPbCl3 nanocrystals (NCs) yields strong orange emission, while the related emission in Mn2+ doped CsPbBr3 NCs is impaired seriously. This is mainly ascribed to back energy transfer from the Mn2+ dopant to the host. Doping Mn2+ into perovskites with multiple-quantum-well (MQW) structures may address this issue, where the energy funnels ensure a rapid energy transfer process, and thus resulting in a high photoluminescence quantum yield (PLQY). Here, we have developed an Ag+ assisted Mn2+ doping method in which Mn2+ can be easily doped into Br-based MQW perovskites. In this MQW perovskites, both nanoplatelets (NPLs) and NCs were formed simultaneously, where efficient energy transfer occurred from the NPLs with a higher energy bandgap to the NCs with a smaller energy bandgap, and then to the Mn2+ dopants. White lighting solution with a PLQY up to 98% has been acquired by altering the experimental parameters, such as reaction time and the Pb-to-Mn feed ratio. The successful doping of Mn2+ into CsPbBr3 host has great significance and shows promising application for next-generation white lighting.

In advanced nuclear power plant AP1000, the passive residual heat removal heat exchanger (PRHR HX) is a key part of the passive safety system. It can transfer decay heat from the reactor core to the water in the in-containment refueling water storage tank (IRWST) during the accidents. The secure operation of the C-shaped PRHR HX has a great impact on the reactor safety. In the present work, the heat transfer performance of a reduced scale PRHR HX was investigated by experiments and numerical simulations. A system including a 6 × 7 C-shaped tube bundle and a rectangular tank was studied. A three-dimensional numerical model using porous media method was developed to explore the transient single phase thermal hydraulic characteristics of the PRHR HX. The distributed resistances caused by the C-shaped tube bundle were calculated by empirical correlations. Both the heat transfer coefficients from the hot fluid in the tube to the inside surface of tube and that from the outer tube surface to the water in the IRWST were calculated by empirical correlations published in literatures. Tests were performed on the 6 × 7 C-shaped tube bundle installed in the middle of the tank. The outer wall temperature and bulk water temperature in the tank were measured by thermocouples. The numerical methods were validated by the experimental results. The calculated results of the local temperature distribution and heat transfer rate were both well consistent with the experimental values. The deviation of the heat transfer rate was smaller than 5%.

In this study, a sponge modified by multi-walled carbon nanotubes (MWNTs) was used as sheet support for the adsorption of CuO@Cu and Ag nanowires to prepare a CuO@Cu/Ag/MWNTs/sponge electrode. Similar to their use in a dielectric barrier discharge (DBD) reactor, the MWNTs changed the conductivity and water absorptivity of the modified electrode, whereas the CuO@Cu and Ag nanowires significantly enhanced the tip effect to increase discharge. The optimal ratio of the Ag:CuO@Cu nanowires was 5:3 at a total adsorbed concentration of 0.8 g L−1. Compared with CuO@Cu and Ag nanowires were separately adsorbed on the MWNTs/sponge, and the CuO@Cu/Ag/MWNTs/sponges recorded higher current response, lower discharge inception voltage, and higher removal efficiency of phenol and 2,4,5-trichlorobiphenyl (PCB29) through their degradation. The removal efficiency reached 100% within 30 min of the reaction for the degradation of phenol and 65.1% within 60 min of the reaction for the degradation of PCB29 at an input voltage of 30 V. These results show that the CuO@Cu/Ag/MWNTs/sponge structure has significant potential for use in the DBD reactor to improve the discharge efficiency of the system and reduce energy consumption, and can be further extended to other types of plasma reactors.

Knowledge of microbial degradation of biochar-adsorbed organic pollutants is essential for recovering adsorption performance of biochars and reducing secondary pollution in soil remediation. In previous study, desorption of organic compounds from biochars was perceived as a prerequisite for the microbial degradation. However, microbial degradation of the nondesorbable organic compounds on biochars has not been studied. Therefore, degradation of nondesorbable naphthalene (NAPH), phenanthrene (PHEN) and pyrene (PYR) on a wood chip-derived biochar (WBC700) by Sphingobium yanoikuyae B1 was investigated. Significant microbial degradations of nondesorbable organic compounds were observed and followed the order of NAPH PHEN PYR. It was newly observed in this study that the microbial degradation of nondesorbable organic compounds on WBC700 was mainly attributed to the •OH in extracellular fluid of Sphingobium yanoikuyae B1. The extracellular •OH was produced through a Fenton-like reaction involved siderophore, H

In this Letter, we report the significant enhancement of the photonic spin Hall effect (SHE) in a plasmonic metasurface with ${\rm S}_4$ symmetry. We find that an enhanced SHE of reflected light can occur in both horizontally and vertically polarized incident beams, and the maximum transverse displacement can approach half of the beam waist. Such a large displacement is caused by the non-resonant and near-zero pseudo-Brewster angles in the plasmonic metasurface. Owing to ${\rm S}_4$ symmetry, a unidirectional SHE is obtained in the metasurface, i.e., large and tiny transverse displacements are realized for a linearly polarized beam incident from the opposite side. This Letter provides a new, to the best of our knowledge, way to achieve an enhanced photonic SHE and offers more opportunities for designing spin-based nanophotonic devices.

Renal fibrosis is the final result of the progression of chronic kidney disease (CKD) to end-stage renal disease (ESRD). Earlier studies confirmed that selenium (Se) displays a close association with kidney diseases. However, the correlation between Se and fibrosis has rarely been explored. Thus, this article mainly aimed to investigate the effect of Se deficiency on renal fibrosis and the Wnt/β-catenin signaling pathway. Twenty BALB/c mice were fed a diet containing 0.02-mg/kg Se (Se-deficient diet) or 0.18-mg/kg Se (standard diet) for 20 weeks. A human glomerular mesangial cell (HMC) cell line was transfected with lentiviral TRNAU1AP-shRNA vector to establish a stable Se deficiency model in vitro. As indicated in this study, the glutathione (GSH) content in the Se-deficient group displayed an obvious decline compared with that in the control group, whereas the content of malondialdehyde (MDA) was obviously elevated. The results of Masson staining showed fibrosis around the renal tubules, and the results of immunohistochemistry showed that the area of positive fibronectin expression increased. In the Se-deficient group, the levels of collagen I, collagen III, matrix metalloproteinase 9 (MMP9), and other fibrosis-related proteins changed significantly in vivo and in vitro. Compared with the control group, the TRNAU1AP-shRNA group showed markedly reduced cell proliferation and migration abilities. Our data indicate that Se deficiency can cause kidney damage and renal fibrosis. Furthermore, the Wnt pathway is critical for the development of tissue and organ fibrosis. The data of this study demonstrated that the expression of Wnt5a, β-catenin, and dishevelled 1 (Dvl-1) was significantly upregulated in the Se-deficient group. Therefore, the Wnt/β-catenin pathway may play an important role in renal fibrosis caused by Se deficiency.