Hybrid Eu(II)-bromide scintillators with efficient 5d-4f bandgap transition for X-ray imaging

Luminescent metal halides are attracting growing attention as scintillators for X-ray imaging in safety inspection,medical diagnosis,etc.Here we present brand-new hybrid Eu(II)-bromide scintillators,1D type[Et4N]EuBr3·MeOH and 0D type[Me4N]6Eu5Br16·MeOH,with spin-allowed 5d-4f bandgap transition emission toward simplified carrier transport during scintillation process.The 1D/0D structures with edge/face-sharing[EuBr6]4−octahedra further contribute to lowing bandgaps and enhancing quantum confinement effect,enabling efficient scintillation performance(light yield~73100±800 Ph MeV^(−1),detect limit~18.6 nGy s^(−1),X-ray afterglow~1%@9.6μs).We demonstrate the X-ray imaging with 27.3 lp mm^(−1) resolution by embedding Eu(II)-based scintillators into AAO film.Our results create the new family of low-dimensional rare-earth-based halides for scintillation and related optoelectronic applications.

Multiferroic monolayers VOX(X = Cl, Br, I): Tunable ferromagnetism via charge doping and ferroelastic switching

The fascinating properties arising from the interaction between different ferroic states of two-dimensional(2D) materials have inspired tremendous research interest in the past few years.Under the first-principles calculations,we predict the coexistence of antiferromagnetic and ferroelastic states in VOX(X=Cl,Br,I) monolayers.The results illustrate that the VOX monolayers exhibit indirect bandgap characteristics,i.e.,their gaps decrease with the halide elements changing from Cl to I.The ground states of all these VOX monolayers are antiferromagnetic(AFM) with the magnetic moments contributed by the V 3d electrons.Furthermore,the magnetic ground state changing from AFM to ferromagnetism(FM) can be realized by doping carriers.In addition,the moderate ferroelastic transition barrier and reversible switching signal ensure their high performances of nonvolatile memory devices.Our findings not only offer an ideal platform for investigating the multiferroic properties,but also provide candidate materials for potential applications in spintronics.

Distinct roles of the IRE1αarm and PERK arm of unfolded protein response in arachidonic acid-induced ferroptosis in hepatocytes

Ferroptosis is a distinct form of cell death that is driven by iron-dependent phospholipid peroxidation.Polyunsaturated fatty acids(PUFAs),particularly arachidonic acid(AA)and adrenal acid(AdA),are most prone to lipid peroxidation,which induces ferroptosis and affects the function of cell membranes.In this study,we discovered that AA induces ferritinophagy in hepatocytes,a selective form of autophagy that degrades ferritin,triggering unstable iron overload.Mechanistically,AA enhances cellular uptake of bound iron by up-regulating transferrin receptor 1(TfR1).Additionally,AA induces endoplasmic reticulum stress(ER stress)and simultaneously activates two of its branches,pancreatic ER kinase(PERK)and inositol-requiring enzyme 1(IRE1).Notably,PERK and IRE1 appear to play distinct roles in inducing ferritinophagy.Inhibition of PERK reduced the AA-induced increase of Fe^(2+)by alleviating ferritinophagy,while inhibition of IRE1 further exacerbated ferroptosis by activating ferritinophagy.Furthermore,there seems to be an interaction between the signaling pathways of ER stress,and inhibition of IRE1 exacerbates AA-induced ferritinophagy by further activating the PERK signaling pathway,thereby exacerbating the extent of cell death.Collectively,our findings suggest that iron overload is involved in AA-induced hepatocyte ferroptosis and that this process is regulated by ER stress-mediated ferritinophagy.This study suggests potential therapeutic strategies for treating liver diseases related to lipid metabolism disorders by intervening in the ferroptosis process.

商务数据分析与应用人才培养的研究和实践

商务数据分析与应用专业是财经商贸大类电子商务类下增设的新专业,如何培养高职层次的专业人才,成为亟待解决的问题。本文主要探讨了商务数据分析与应用专业人才培养的背景,培养定位,课程和教学体系的构建,师资队伍建设,实验实训基地建设,电子商务行业数据分析人才培养。

Ultra-lightweight Ti3C2Tx MXene modified separator for Li–S batteries:Thickness regulation enabled polysulfide inhibition and lithium ion transportation

The practical application of lithium–sulfur(Li–S)batteries is limited by the easy dissolution of polysulfides in the electrolyte,resulting in the lithium polysulfide(LPS)shuttle effect.Several two-dimensional(2D)materials with abundant active binding sites and high surface-to-volume ratios have been developed to prepare functional separators that suppress the diffusion of polysulfides.However,the influence of modified layer thickness on Li+transport has not been considered.Herein,we synthesized individual and multilayered 2D Ti3C2Tx MXene nanosheets and used them to fabricate a series of Ti3C2Tx-PP modified separators.The separators had mass loadings ranging from 0.16 to 0.016 mg cm-2,which is the lowest value reported for 2D materials to the best of our knowledge.The corresponding reductions in thickness ranged from 1.2μm to 100 nm.LPS shuttling was effectively suppressed,even at the lowest mass loading of 0.016 mg cm-2.Suppression was due to the strong interaction between LPS intermediates and Ti atoms and hydroxyl functional groups on the separator surface.The lithium-ion diffusion coefficient increased with the reduction of Ti3C2Tx layers on the separator.Superior cycling stability and rate performance were attained when the separator with a Ti3C2Tx-PP mass loading of 0.016 mg cm-2 was incorporated into a Li–S battery.Carbon nanotubes(CNTs)were introduced into the separators to further improve the electrical and Li+ionic conductivity in the cross-plane direction of the 2D Ti3C2Txlayers.With the ultralightweight Ti3C2Tx/CNTs modified PP separator,the cell maintained a capacity of 640 m Ah g-1after 200cycles at 1C with a capacity decay of only 0.079%per cycle.

The role of graphene coating on cordierite-supported Pd monolithic catalysts for low-temperature combustion of toluene

In the present work,a Pd/graphene/cordierite(Pd/Gr/Cor)composite was prepared as a monolithic catalyst for low-temperature combustion of toluene.We mainly focused on understanding the role of graphene coating through investigation of catalytic performance and adsorption behavior of the composite.Compared with the traditional Pd/Cor catalyst without graphene coating,Pd/Gr/Cor catalyst delivered much higher activity and stability for toluene catalytic combustion in both dry and moist conditions.Transmission electron microscopy(TEM)and hydrophobic characterizations indicated that graphene coating can considerably improve the dispersity of Pd nanoparticles and enhance the hydrophobicity of the cordierite support.The adsorption behavior of the above two catalysts,including adsorption isothermal,adsorption kinetics,and adsorption thermodynamics were carefully investigated.The simulation results indicated that a large amount of toluene was adsorbed on graphene surface through relatively weak interaction,whereas only a relatively small amount of toluene was adsorbed on Pd surface with strong affinity.The adsorption thermal calculation indicated that the adsorption of toluene on graphene was a process with reduced entropy,indicating highly-ordered assembly of toluene molecular on graphene.It is the significant concentration and affinity gap between graphene and Pd that ensures a simultaneously and rapid transfer of toluene during the reaction process.

A closed-loop particle swarm optimizer for multivariable process controller design

Design of general multivariable process controllers is an attractive and practical alternative to optimizing design by evolutionary algorithms (EAs) since it can be formulated as an optimization problem. A closed-loop particle swarm optimization (CLPSO) algorithm is proposed by mapping PSO elements into the closed-loop system based on control theories. At each time step, a proportional integral (PI) controller is used to calculate an updated inertia weight for each particle in swarms from its last fitness. With this modification, limitations caused by a uniform inertia weight for the whole population are avoided, and the particles have enough diversity. After the effectiveness, efficiency and robustness are tested by benchmark functions, CLPSO is applied to design a multivariable proportional-integral-derivative (PID) controller for a solvent dehydration tower in a chemical plant and has improved its performances.

Serial therapies oriented by surgery for large primary liver carcinoma

Objective: To discuss the methods and effects of serial therapies oriented by surgery in the treatment of pri- mary large liver cancers. Methods: From January 1993 to June 1999, 191 pa- tients with large liver carcinoma were treated surgi- cally. The size of tumors varied from 5.2 to 19.7 cm (mean 9.4 cm). Several types of liver resections were made in 121 patients and as a supplement, cry- osurgery was carried out for the remaining 70 pa- tients. Importable drug delivery system was institu- ted intraoperatively. Transcatheter arterial chemo- embolization (THP 30-60 mg, E-ADM 20-40 mg, CDDP 40-80 mg, MMC 10-20 mg, iodin oil 5-30 ml), percutaneous ethanol injection, bioimmunother- apy and traditional Chinese medicine were used pre- and post-operatively. CT angiography and CT dur- ing arterial portography were used to find satellite nodules. Early stage recurrences were predicted by AFPmRNA in peripheral blood. Child-Pugh's classi- fication plus branch chain amino acid/aromatic ami- no acid ratio (BCAA/AAA) was adopted in evalua- ting pre-operative liver functions. Results: Marked results were observed after serial treatments oriented by surgery. The 1-, 3- and 5- year survival rates in resection group were 75.8 %, 45.6% and 30.4%. respectively. The 1- and 3-year survival rates in cryosurgery group were 63.2 % and 37.0 %. The operative mortality was 1.57 %. Recur- rence rates were 69.2 % in AFPmRNA positive group and 33.3% in AFPmRNA negative group (P< 0.05). The BCAA/AAA ratio was lower than 1.5 in two patients who died of hepatic failure after resec- tion. Conclusions: Serial treatments with surgery as the chief modality gives satisfactory results in patients with large primary liver carcinoma. This regimen should be regarded as a main strategy to deal with large liver carcinoma. AFPmRNA in the peripheral blood, signifying a recurrence, may become a new clinical parameter. The BCAA/AAA ratio plus Child-Pugh's classification is able to evaluate more accurately liver function reserve before surgery.

Stability of Ag@SiO2 core–shell particles in conditions of photocatalytic overall water-splitting

Core–shell nanoparticles containing plasmonic metals（Ag or Au） have been frequently reported to enhance performance of photo-electrochemical（PEC） devices. However, the stability of these particles in water-splitting conditions is usually not addressed. In this study we demonstrate that Ag@SiOcore–shell particles are instable in the acidic conditions in which WO-based PEC cells typically operate, Ag in the core being prone to oxidation, even if the SiOshell has a thickness in the order of 10 nm. This is evident from in situ voltammetry studies of several anode composites. Similar to the results of the PEC experiments, the Ag@SiOcore–shell particles are instable in slurry-based, Pt/ZnO induced photocatalytic water-splitting. This was evidenced by in situ photodeposition of Ag nanoparticles on the Pt-loaded ZnO catalyst, observed in TEM micrographs obtained after reaction. We explain the instability of Ag@SiOby OH-radical induced oxidation of Ag, yielding dissolved Ag+. Our results imply that a decrease in shell permeability for OH-radicals is necessary to obtain stable, Ag-based plasmonic entities in photo-electrochemical and photocatalytic water splitting.

Hepatic trisegmentectomy for 29 patients with huge liver neoplasms

Objective: To evaluate retrospectively the feasibility and effect of hepatic trisegmentectomy in therapy of huge neoplasms of the liver. Methods: From July 1993 to October 1999, 29 pa- tients with huge hepatic neoplasms underwent hepatic trisegmentectomy. Of these, 23 patients suffered from primary liver cancer, 1 hepatic infiltration of gallbladder cancer, 1 metastasis of colon cancer, 1 hepatic angiosarcoma, 1 hepatic neurofibroma, and 2 huge liver cysts. Twenty-six patients were subjected to right trisegmentectomy and the rest 3 left triseg- mentectomy. All trisegmentectomies were performed under normothermic interruption of the porta hepatis at single time and these interruptions lasted 15 to 40 minutes. Results: The relatively good effect was seen in our se- ries. The 1-, 3-, 5-year survival rates for primary liver cancer patients were 63.6%, 36.4% and 27.3 %, respectively. The survival period for the pa- tients with hepatic infiltration of gallbladder cancer and liver metastasis of colon cancer was 6 months. Those with hepatic angiosarcoma, hepatic neurofi- broma and huge liver cysts have been surviving 35, 26, 25 and 40 months, respectively. Major complica- tions were noted in 5 patients, and one (3.4%, 1/29) died. Conclusion: Hepatic trisegmentectomy is safe and ef- fective in treatment of huge hepatic neoplasms if its indications and operative techniques are properly mastered.

Effect of particle micro-structure on the electrochemical properties of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cathode material

Ni-rich layered material is a kind of high-capacity cathode to meet the requirement of electric vehicles.As for the typical LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) material,the particle formation is significant for electrochemical properties of the cathode.In this work,the structure,morphology,and electrochemical performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) secondary particles and single crystals were systematically studied.A lower Ni^(2+)/Ni^(3+)molar ratio of 0.66 and a lower residual alkali content of 0.228wt%were achieved on the surface of the single crystals.In addition,the single crystals showed a discharge capacity of 191.6 mAh/g at 0.2 C(~12 mAh/g lower than that of the secondary particles)and enhanced the electrochemical stability,especially when cycled at 50℃ and in a wider electrochemical window(between 3.0 and 4.4 V vs.Li+/Li).The LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) secondary particles were suitable for applications requiring high specific capacity,whereas single crystals exhibited better stability,indicating that they are more suitable for use in long life requested devices.

Insight into influence of thermodynamic coefficients on transient negative capacitance in Zr-doped HfO_(2) ferroelectric capacitors

We study the influence of the thermodynamic coefficients on transient negative capacitance for the Zr-doped HfO_(2)(HZO)ferroelectric capacitors by the theoretical simulation based on the Landau-Khalatnikov(L-K)theory and experimental measurement of electrical properties in the resistor-ferroelectric capacitor(R-FEC)circuit.Our results show that the thermodynamic coefficientsα,βandγalso play a key role for the transient NC effect besides the viscosity coefficient and series resistor.Moreover,the smaller coefficientsαandβ,the more significant the transient NC effect.In addition,we also find that the thermodynamic process of transient NC does not obey the generally accepted viewpoint of Gibbs free energy minimization.

Nb_(2)CT_(x)MXene boosting PEO polymer electrolyte for all-solid-state Li-S batteries:two birds with one stone strategy to enhance Li+conductivity and polysulfide adsorptivity

All-solid-state lithium-sulfur(Li-S)battery is regarded as next-generation high energy density and safety battery system.The key challenge is to develop a compatible high-performance solid-state electrolyte.Herein,a two birds with one stone strategy is proposed to simultaneously enhance Li+conductivity and polysulfide adsorptivity of poly(ethylene oxide)(PEO)-based polymer electrolyte via the integration of Nb_(2)CT_(x)MXene.Moreover,the sheet size of Nb_(2)CT_(x)MXene is crucial for the enhancement of Li^(+)conductivity and polysulfide adsorptivity,attributing to the difference in a specific surface area related to the percolation effect.By tuning the sheet size of Nb_(2)CT_(x)MXene from 500-300 nm to below 100 nm,the ionic conductivity of the PEO electrolyte is increased to2.62×10^(-4)S·cm^(-1)with improved Li+transference number of 0.37 at 600C.Furthermore,theoretical calculation and X-ray photoelectron spectroscopy(XPS)conjointly prove that poly sulfides could be effectively adsorbed by Nb2CTxnanosheets via forming Nb-S bonding to inhibit their shuttle in the PEO framework.As a result,the all-solid-state Li-S cell exhibits an initial capacity of 1149 mAh·g^(-1)at 0.5C and good cycling stability with 491 mAh·g^(-1)after 200 cycles.The results demonstrate the necessity of polysulfide inhibition and the application of Nb_(2)CT_(x)MXene in PEO-based electrolytes for all-solid-state Li-S batteries.

Experimental and numerical efforts to improve oxygen mass transport in porous catalyst layer of proton exchange membrane fuel cells

The effective management of oxygen transport resistance(OTR)within the cathode catalyst layer(CCL)is crucial for achieving a high catalyst performance at low platinum(Pt)loading.Over the past two decades,significant advancements have been made in the development of various high active platinum-based catalysts,aiming at enhancing oxygen mass transport and the oxygen reduction reaction(ORR).However,experimental investigations of transport processes in porous media are often computational costs and restrained by limitations in in-situ measurement capabilities,as well as spatial and temporal resolution.Fortunately,numerical simulation provides a valuable alternative for unveiling the intricate relationship between local transport properties and overall cell performance that remain unresolved or uncoupled through experimental approach.In this review,we elucidate the primary experimental and numerical efforts undertaken to improve OTR.We consolidate the available literature on OTR values and perform a quantitative comparison of the effectiveness of different strategies in mitigating OTR.Furthermore,we analyze the intrinsic limitations and challenges associated with current experimental and numerical methods.Finally,we outline future prospect for advancements in both experimental techniques and modelling methods.

Crystal phase control and ignition properties of HNS/CL-20 composite microspheres prepared by microfluidics combined with emulsification techniques

Improved controllability and energy density of ignition agents are of great significance for the devel-opment of energetic composite materials.In this study,droplet microfluidics and emulsification tech-niques were combined to prepare HNS/CL-20 composite microspheres with polyglycidyl azide polymer(GAP)as the binder.The influence of binder content on the morphology of microspheres was investi-gated,and the microspheres were characterized and tested for particle size,crystal structure,thermal decomposition,dispersibility,mechanical sensitivity,combustion behavior and detonation performance.The results showed that microspheres prepared with a binder content of 3%had higher sphericity and particle size uniformity.The microspheres retained the crystal structure of both HNS and CL-20(ε-type).Compared with raw HNS,the microspheres had higher apparent activation energy,better safety per-formance,and good dispersibility.The ignition experiments and detonation performance tests show that HNS/CL-20 composite microspheres have excellent ignition performance,obvious combustion flame,and significant energy release effects,which are expected to achieve high energy and high-speed response of the igniter,thus improving the ignition reliability in special environments or systems.

Efficient single‑pixel imaging based on a compact fiber laser array and untrained neural network

This paper presents an efficient scheme for single-pixel imaging(SPI)utilizing a phase-controlled fiber laser array and an untrained deep neural network.The fiber lasers are arranged in a compact hexagonal structure and coherently combined to generate illuminating light fields.Through the utilization of high-speed electro-optic modulators in each individual fiber laser module,the randomly modulated fiber laser array enables rapid speckle projection onto the object of interest.Furthermore,the untrained deep neural network is incorporated into the image reconstructing process to enhance the quality of the reconstructed images.Through simulations and experiments,we validate the feasibility of the proposed method and successfully achieve high-quality SPI utilizing the coherent fiber laser array at a sampling ratio of 1.6%.Given its potential for high emitting power and rapid modulation,the SPI scheme based on the fiber laser array holds promise for broad applications in remote sensing and other applicable fields.

Morphology and photocatalytic tetracycline degradation of g-C_(3)N_(4) optimized by the coal gangue

Coal gangue(CG),a solid waste from coal mining and processing,has raised concerns about its environmental impact.Graphitic carbon nitride(g-C_(3)N_(4))is promising for photocatalytic decomposition of organic pollutants,but its performance is hampered by its inherent defects.In this study,the compound of coal gangue and g-C_(3)N_(4)was formed by in-situ loading g-C_(3)N_(4)on the surface of coal gangue.After recombination,the morphology of g-C_(3)N_(4)changes from block structure to tremella nanosheet.This change not only increases the specific surface area of g-C_(3)N_(4),but also broadens the light absorption spectrum of g-C_(3)N_(4).Compared with original g-C_(3)N_(4),the photo-current of the complex in visible light is increased twice,and the tetracycline(TC)degradation rate is 2.1 times faster.The structure,optical properties,band structure,morphology and charge transfer mechanism of the composite were analyzed by a series of characterization techniques.It is found that coal gangue can promote the space charge transfer and separation of g-C_(3)N_(4),and the cyclic test compound has good activity stability.In this paper,a strategy of comprehensive utilization of coal gangue is proposed,which can not only reduce the envi-ronmental risk of coal gangue,but also provide carbon nitride(CN)based photocatalytic materials with superior photocatalytic properties.

2×3 kW bidirectional output fiber oscillator employing spindle-shaped ytterbium-doped fiber

A 2×3 kW-level bidirectional output fiber oscillator is realized by combining the specially designed spindle-shaped ytterbium-doped fiber,non-wavelength-stabilized 976-nm LDs,and grating bandwidth optimization to balance transverse mode instability and stimulated Raman scattering.The maximum output powers at both ends are 3265 and 2840 W,respectively,with a total efficiency of 73.2%.The M^(2) factors of the lasers at both ends are about 1.98 and 2.38,respectively.The beam profile at both ends shows that a bidirectional output annular beam fiber oscillator has been realized,which has great potential in practical applications.

Formation mechanism and modeling of surface waviness in incremental sheet forming

mproving and controlling surface quality has always been a challenge for incremental sheet forming (ISF), whereas the generation mechanism of waviness surface is still unknown, which impedes the widely application of ISF in the industrial field. In this paper, the formation mechanism and the prediction of waviness are both investigated through experiments, numerical simulation, and theoretical analysis. Based on a verified finite element model, the waviness topography is predicted numerically for the first time, and its generation is attributed to the residual bending deformation through deformation history analysis. For more efficient engineering application, a theoretical model for waviness height is proposed based on the generation mechanism, using a modified strain function considering deformation modes. This work is favorable for the perfection of formation mechanism and control of surface quality in ISF.

Layered oxide cathodes for sodium-ion batteries: From air stability, interface chemistry to phase transition

Sodium-ion batteries(SIBs)are considered as a low-cost complementary or alternative system to prestigious lithium-ion batteries(LIBs)because of their similar working principle to LIBs,cost-effectiveness,and sustainable availability of sodium resources,especially in large-scale energy storage systems(EESs).Among various cathode candidates for SIBs,Na-based layered transition metal oxides have received extensive attention for their relatively large specific capacity,high operating potential,facile synthesis,and environmental benignity.However,there are a series of fatal issues in terms of poor air stability,unstable cathode/electrolyte interphase,and irreversible phase transition that lead to unsatisfactory battery performance from the perspective of preparation to application,outside to inside of layered oxide cathodes,which severely limit their practical application.This work is meant to review these critical problems associated with layered oxide cathodes to understand their fundamental roots and degradation mechanisms,and to provide a comprehensive summary of mainstream modification strategies including chemical substitution,surface modification,structure modulation,and so forth,concentrating on how to improve air stability,reduce interfacial side reaction,and suppress phase transition for realizing high structural reversibility,fast Na+kinetics,and superior comprehensive electrochemical performance.The advantages and disadvantages of different strategies are discussed,and insights into future challenges and opportunities for layered oxide cathodes are also presented.