Review of the Research Status of Practical Superconducting Materials and Their Current Carrying Performance

Superconducting materials hold great potential in high field magnetic applications compared to traditional conductive materials.At present,practical superconducting materials include low-temperature superconductors such as NbTi and Nb3Sn,high-temperature superconductors such as Bi-2212,Bi-2223,YBCO,iron-based superconductors and MgB2.The development of low-temperature superconducting wires started earlier and has now entered the stage of industrialized production,showing obvious advantages in mechanical properties and cost under low temperature and middle-low magnetic field.However,due to the insufficient intrinsic superconducting performance,low-temperature superconductors are unable to exhibit excellent performance at high temperature or high fields.Further improvement of supercurrent carrying performance mainly depends on the enhancement of pinning ability.High-temperature superconductors have greater advantages in high temperature and high field,but many of them are still in the stage of further performance improvement.Many high-temperature superconductors are limited by the deficiency in their polycrystalline structure,and further optimization of intergranular connectivity is required.In addition,it is also necessary to further enhance their pinning ability.The numerous successful application instances of high-temperature superconducting wires and tapes also prove their tremendous potential in electric power applications.

Integrated causal inference modeling uncovers novel causal factors and potential therapeutic targets of Qingjin Yiqi granules for chronic fatigue syndrome

Objective:Chronic fatigue syndrome(CFS)is a prevalent symptom of post-coronavirus disease 2019(COVID-19)and is associated with unclear disease mechanisms.The herbal medicine Qingjin Yiqi granules(QJYQ)constitute a clinically approved formula for treating post-COVID-19;however,its potential as a drug target for treating CFS remains largely unknown.This study aimed to identify novel causal factors for CFS and elucidate the potential targets and pharmacological mechanisms of action of QJYQ in treating CFS.Methods:This prospective cohort analysis included 4,212 adults aged≥65 years who were followed up for 7 years with 435 incident CFS cases.Causal modeling and multivariate logistic regression analysis were performed to identify the potential causal determinants of CFS.A proteome-wide,two-sample Mendelian randomization(MR)analysis was employed to explore the proteins associated with the identified causal factors of CFS,which may serve as potential drug targets.Furthermore,we performed a virtual screening analysis to assess the binding affinity between the bioactive compounds in QJYQ and CFS-associated proteins.Results:Among 4,212 participants(47.5%men)with a median age of 69 years(interquartile range:69–70 years)enrolled in 2004,435 developed CFS by 2011.Causal graph analysis with multivariate logistic regression identified frequent cough(odds ratio:1.74,95%confidence interval[CI]:1.15–2.63)and insomnia(odds ratio:2.59,95%CI:1.77–3.79)as novel causal factors of CFS.Proteome-wide MR analysis revealed that the upregulation of endothelial cell-selective adhesion molecule(ESAM)was causally linked to both chronic cough(odds ratio:1.019,95%CI:1.012–1.026,P=2.75 e^(−05))and insomnia(odds ratio:1.015,95%CI:1.008–1.022,P=4.40 e^(−08))in CFS.The major bioactive compounds of QJYQ,ginsenoside Rb2(docking score:−6.03)and RG4(docking score:−6.15),bound to ESAM with high affinity based on virtual screening.Conclusions:Our integrated analytical framework combining epidemiological,genetic,and in silico data provides a novel strategy for elucidating complex disease mechanisms,such as CFS,and informing models of action of traditional Chinese medicines,such as QJYQ.Further validation in animal models is warranted to confirm the potential pharmacological effects of QJYQ on ESAM and as a treatment for CFS.

Structure, synthesis, and catalytic properties of nanosize cerium-zirconium-based solid solutions in environmental catalysis

Nanosize cerium-zirconium solid solution(CZO)with a special fluorite structure has received an increasing research interest due to their remarkable advantages such as excellent oxygen storage capacity and great flexibility in their composition and structure.By partial metal(including rare earth,transition,alkaline earth or other metal)doping into CZO,the physicochemical properties of these catalytic materials can be controllable adjusted for the study of specific reactions.To date,nanosize CZO has been prepared by co-precipitation,sol-gel,surfactant-assisted approach,solution combustion,micro-emulsion,high energy mechanical milling,etc.The advent of these methodologies has prompted researchers to construct well-defined networks with customized micromorphology and functionalities.In this review,we describe not only the basic structure and synthetic strategies of CZO,but also their relevant applications in environmental catalysis,such as the purification for CO,nitrogen oxides(NOx),volatile organic compounds(VOC),soot,hydrocarbon(HC),CO2 and solid particulate matters(PM),and some reaction mechanisms are also summarized.

Fabrication of La1-xCaxFeO3 perovskite-type oxides with macro-mesoporous structure via a dual-template method for highly efficient soot combustion

A series of three-dimensionally ordered macro-mesoporous(3DOMM)La1-xCaxFeO3(x=0-0.3)perovskite-type oxides were designed and successfully fabricated for the first time via a dual-template method.In which,PMMA and Brij-56 were employed as the hard template and soft template,respectively.It is found that 3 DOMM La1-xCaxFeO3 exhibits abundant wormlike mesoporous channels about 3 nm in diameter on macroporous skeleton walls.The excellent catalytic activity of soot combustion benefits from not only the well-designed hierarchical porous structure of catalyst,but also the redox electron pair of Fe3+/Fe4+induced by the doping of low-valent alkaline earth metal Ca to A-site of LaFeO3.3DOMM La0.8Ca0.2FeO3 exhibits superior catalytic performance for soot combustion,which shows T50 of396℃.It is 189℃lower than that without catalyst.A combination of structure and composition in the design of catalyst can be widely extended to other catalytic systems.

Synthesis and kinetics investigation of meso-microporous Cu-SAPO-34 catalysts for the selective catalytic reduction of NO with ammonia

A series of meso-microporous Cu-SAPO-34 catalysts were successfully synthesized by a one-pot hydrothermal crystallization method, and these catalysts exhibited excellent NH3-SCR performance at low temperature. Their structure and physic chemical properties were characterized by means of X-ray diffraction patterns （XRD）, Scanning electron microscopy （SEM）, Transmission electron microscopy （TEM）, N2 sorption-desorption, nuclear magnetic resonance （NMR）, Inductively Coupled Plasma-Atomic Emission spectrometer （ICP-AES）, X-ray absorption spectroscopy （XPS）, Temperature-programmed desorption of ammonia （NH3-TPD）, Ultraviolet visible diffuse reflectance spectroscopy （UV-Vis DRS） and Temperature programmed reduction （TPR）. The analysis results indicate that the high activities of Cu-SAPO-34 catalysts could be attributed to the enhancement of redox property, the formation of mesopores and the more acid sites. Furthermore, the kinetic results verify that the formation of mesopores remarkably reduces diffusion resistance and then improves the accessibility of reactants to catalytically active sites. The 1.0-Cu-SAPO-34 catalyst exhibited the high NO conversion （〉90%） among the wide activity temperature window in the range of 150- 425℃.

Engineering the electronic and geometric structure of VO_(x)/BN@TiO_(2)heterostructure for efficient aerobic oxidative desulfurization

Particle size governs the electronic and geometric structure of metal nanoparticles(NPs),shaping their catalytic performances in heterogeneous catalysis.However,precisely controlling the size of active metal NPs and thereafter their catalytic activities remain an affordable challenge in ultra-deep oxidative desulfurization(ODS)field.Herein,a series of highly-efficient VO_(x)/boron nitride nanosheets(BNNS)@TiO_(2)heterostructures,therein,cetyltrimethylammonium bromide cationic surfactants serving as intercalation agent,BNNS and MXene as precursors,with various VO_(x)NP sizes were designed and controllably constructed by a facile intercalation confinement strategy.The properties and structures of the prepared catalysts were systematically characterized by different technical methods,and their catalytic activities were investigated for aerobic ODS of dibenzothiophene(DBT).The results show that the size of VO_(x)NPs and V^(5+)/V^(4+)play decisive roles in the catalytic aerobic ODS of VO_(x)/BNNS@TiO_(2)catalysts and that VO_(x)/BNNS@TiO_(2)-2 exhibits the highest ODS activity with 93.7%DBT conversion within 60 min under the reaction temperature of 130℃and oxygen flow rate of 200 mL·min-1,which is due to its optimal VO_(x)dispersion,excellent reducibility and abundant active species.Therefore,the finding here may contribute to the fundamental understanding of structure-activity in ultradeep ODS and inspire the advancement of highly-efficient catalyst.

Phase evolution mechanism study and fabrication of PbMo_(6)S_(8) superconducting materials with two-step sintering process

PbMo6S 8 superconducting materials are considered to have great potential for practical applications at low temperatures and high fields due to their high upper critical field,low anisotropy,and low preparation cost.In this work,PbMo_(6)S_(8) bulks were prepared through a solid‐state sintering process using PbS,Mo,and MoS_(2) as raw materials.The phase evolution mechanism during the sintering of PbMo_(6)S_(8) was studied in detail.It was found that during sintering at 750℃ for 24 h,both the S and Pb atoms diffuse into the Mo and MoS_(2) particles,leading to the formation of the PbMo_(6)S_(8) phase.After sintering at 950℃ for 72 h,a high superconducting phase content was obtained in the bulk;however,numerous pores remained.Therefore,in order to obtain a higher density for the bulk,a two‐step sintering process was developed.Based on this technique,PbMo_(6)S_(8) bulks with a higher bulk density and a higher superconducting phase content were obtained.This study provides an effective method for the fabrication of high‐quality precursor powders,which can be the foundation for the future fabrication of PbMo_(6)S_(8) superconducting long wires or tapes for practical applications.

Review of Core-shell structure zeolite-based catalysts for NO_(x)emission control

Nitrogen oxides(NO_(x))from diesel engine exhaust,is one of the major sources of environmental pollution.Currently,selective catalytic reduction with ammonia(NH_(3)-SCR)is considered to be the most effective protocol for reducing NO_(x)emissions.Nowadays,zeolitebased NH_(3)-SCR catalysts have been industrialized and widespread used in this field.Nevertheless,with the increasingly stringent environmental regulations and implementation of the requirement of“zero emission”of diesel engine exhaust,it is extremely urgent to prepare catalysts with superior NH_(3)-SCR activity and exceptional resistance to poisons(SO2,alkali metals,hydrocarbons,etc.).Core-shell structure zeolite-based catalysts(CSCs)have shown great promise in NH_(3)-SCR of NO_(x)in recent years by virtue of its relatively higher low-temperature activity,broader operation temperature window and outstanding resistance to poisons.This review mainly focuses on the recent progress of CSCs for NH_(3)-SCR of NO_(x)with three extensively investigated SSZ-13,ZSM-5,Beta zeolites as cores.The reaction mechanisms of resistance to sulfur poisoning,alkali metal poisoning,hydrocarbon poisoning,and hydrothermal aging are summarized.Moreover,the important role of interfacial effect between core and shell in the reaction of NH_(3)-SCR was clarified.Finally,the future development and application outlook of CSCs are prospected.