Although lithium-sulfur batteries(LSBs)exhibit high theoretical energy density,their practical application is hindered by poor conductivity of the sulfur cathode,the shuttle effect,and the irreversible deposition of L...Although lithium-sulfur batteries(LSBs)exhibit high theoretical energy density,their practical application is hindered by poor conductivity of the sulfur cathode,the shuttle effect,and the irreversible deposition of Li_(2)S.To address these issues,a novel composite,using electrospinning technology,consisting of Fe_(3)Se_(4)and porous nitrogen-doped carbon nanofibers was designed for the interlayer of LSBs.The porous carbon nanofiber structure facilitates the transport of ions and electrons,while the Fe_(3)Se_(4)material adsorbs lithium polysulfides(LiPSs)and accelerates its catalytic conversion process.Furthermore,the Fe_(3)Se_(4)material interacts with soluble LiPSs to generate a new polysulfide intermediate,Li_(x)FeS_(y)complex,which changes the electrochemical reaction pathway and facilitates the three-dimensional deposition of Li_(2)S,enhancing the reversibility of LSBs.The designed LSB demonstrates a high specific capacity of1529.6 mA h g^(-1)in the first cycle at 0.2 C.The rate performance is also excellent,maintaining an ultra-high specific capacity of 779.7 mA h g^(-1)at a high rate of 8 C.This investigation explores the mechanism of the interaction between the interlayer and LiPSs,and provides a new strategy to regulate the reaction kinetics and Li_(2)S deposition in LSBs.展开更多
Using aeolian sand(AS)for goaf backfilling allows coordination of green mining and AS control.Cemented AS backfill(CASB)exhibits brittle fracture.Polypropylene(PP)fibers are good toughening materials.When the tougheni...Using aeolian sand(AS)for goaf backfilling allows coordination of green mining and AS control.Cemented AS backfill(CASB)exhibits brittle fracture.Polypropylene(PP)fibers are good toughening materials.When the toughening effect of fibers is analyzed,their influence on the slurry conveying performance should also be considered.Additionally,cement affects the interactions among the hydration products,fibers,and aggregates.In this study,the effects of cement content(8wt%,9wt%,and 10wt%)and PP fiber length(6,9,and 12 mm)and dosage(0.05wt%,0.1wt%,0.15wt%,0.2wt%,and 0.25wt%)on fluidity and mechanical properties of the fibertoughened CASB(FCASB)were analyzed.The results indicated that with increases in the three aforementioned factors,the slump flow decreased,while the rheological parameters increased.Uniaxial compressive strength(UCS)increased with the increase of cement content and fiber length,and with an increase in fiber dosage,it first increased and then decreased.The strain increased with the increase of fiber dosage and length.The effect of PP fibers became more pronounced with the increase of cement content.Digital image correlation(DIC)test results showed that the addition of fibers can restrain the peeling of blocks and the expansion of fissure,and reduce the stress concentration of the FCASB.Scanning electron microscopy(SEM)test indicated that the functional mechanisms of fibers mainly involved the interactions of fibers with the hydration products and matrix and the spatial distribution of fibers.On the basis of single-factor analysis,the response surface method(RSM)was used to analyze the effects of the three aforementioned factors and their interaction terms on the UCS.The influence surface of the two-factor interaction terms and the three-dimensional scatter plot of the three-factor coupling were established.In conclusion,the response law of the FCASB properties under the effects of cement and PP fibers were obtained,which provides theoretical and engineering guidance for FCASB filling.展开更多
Nonreciprocity of thermal metamaterials has significant application prospects in isolation protection,unidirectional transmission,and energy harvesting.However,due to the inherent isotropic diffusion law of heat flow,...Nonreciprocity of thermal metamaterials has significant application prospects in isolation protection,unidirectional transmission,and energy harvesting.However,due to the inherent isotropic diffusion law of heat flow,it is extremely difficult to achieve nonreciprocity of heat transfer.This review presents the recent developments in thermal nonreciprocity and explores the fundamental theories,which underpin the design of nonreciprocal thermal metamaterials,i.e.,the Onsager reciprocity theorem.Next,three methods for achieving nonreciprocal metamaterials in the thermal field are elucidated,namely,nonlinearity,spatiotemporal modulation,and angular momentum bias,and the applications of nonreciprocal thermal metamaterials are outlined.We also discuss nonreciprocal thermal radiation.Moreover,the potential applications of nonreciprocity to other Laplacian physical fields are discussed.Finally,the prospects for advancing nonreciprocal thermal metamaterials are highlighted,including developments in device design and manufacturing techniques and machine learning-assisted material design.展开更多
This work demonstrates a novel polymerization-derived polymer electrolyte consisting of methyl methacrylate,lithium bis(trifluoromethanesulfonyl)imide and fluoroethylene carbonate.The polymerization of MMA was initiat...This work demonstrates a novel polymerization-derived polymer electrolyte consisting of methyl methacrylate,lithium bis(trifluoromethanesulfonyl)imide and fluoroethylene carbonate.The polymerization of MMA was initiated by the amino compounds following an anionic catalytic mechanism.LiTFSI plays both roles including the initiator and Li ion source in the polymer electrolyte.Normally,lithium bis(trifluoromethanesulfonyl)imide has difficulty in initiating the polymerization reaction of methyl methacrylate monomer,a very high concentration of lithium bis(trifluoromethanesulfonyl)imide is needed for initiating the polymerization.However,the fluoroethylene carbonate additive can work as a supporter to facilitate the degree of dissociation of lithium bis(trifluoromethanesulfonyl)imide and increase its initiator capacity due to the high dielectric constant.The as-prepared poly-methyl methacrylate-based polymer electrolyte has a high ionic conductivity(1.19×10^(−3)S cm^(−1)),a wide electrochemical stability window(5 V vs Li^(+)/Li),and a high Li ion transference number(t_(Li^(+)))of 0.74 at room temperature(RT).Moreover,this polymerization-derived polymer electrolyte can effectively work as an artificial protective layer on Li metal anode,which enabled the Li symmetric cell to achieve a long-term cycling performance at 0.2 mAh cm^(−2)for 2800 h.The LiFePO_(4)battery with polymerization-derived polymer electrolyte-modified Li metal anode shows a capacity retention of 91.17%after 800 cycles at 0.5 C.This work provides a facile and accessible approach to manufacturing poly-methyl methacrylate-based polymerization-derived polymer electrolyte and shows great potential as an interphase in Li metal batteries.展开更多
The use of aeolian sand(AS)as an aggregate to prepare coal mine cemented filling materials can resolve the problems of gangue shortage and excessive AS deposits.Owing to the lack of research on the mechanism of cement...The use of aeolian sand(AS)as an aggregate to prepare coal mine cemented filling materials can resolve the problems of gangue shortage and excessive AS deposits.Owing to the lack of research on the mechanism of cemented AS backfill(CASB),the response surface method(RSM)was adopted in this study to analyze the influence of ordinary Portland cement(PO)content(x_(1)),fly ash(FA)-AS(FA-AS)ratio(x_(2)),and concentration(x_(3))on the mechanical and microscopic properties of the CASB.The hydration characteristics and internal pore structure of the backfill were assessed through thermogravimetric/derivative thermogravimetric analysis,mercury intrusion porosimetry,and scanning electron microscopy.The RSM results show that the influence of each factor and interaction term on the response values is extremely significant(except x_(1)x_(3),which had no obvious effect on the 28 d strength).The uniaxial compressive strength(UCS)increased with the PO content,FA-AS ratio,and concentration.The interaction effects of x_(1)x_(2),x_(1)x_(3),and x_(2)x_(3) on the UCS at 3,7,and 28 d were analyzed.In terms of the influence of interaction items,an improvement in one factor promoted the strengthening effect of another factor.The enhancement mechanism of the curing time,PO content,and FA-AS ratio on the backfill was reflected in the increase in hydration products and pore structure optimization.By contrast,the enhancement mechanism of the concentration was mainly the pore structure optimization.The UCS was positively correlated with weight loss and micropore content but negatively correlated with the total porosity.The R^(2) value of the fitting function of the strength and weight loss,micropore content,and total porosity exceeded 0.9,which improved the characterization of the enhancement mechanism of the UCS based on the thermogravimetric analysis and pore structure.This work obtained that the influence rules and mechanisms of the PO,FA-AS,concentration,and interaction terms on the mechanical properties of the CASB provided a certain theoretical and engineering guidance for CASB filling.展开更多
Hybrid CuO-Co_(3)O_(4)nanosphere building blocks have been embedded between the layered nanosheets of reduced graphene oxides with a three dimensional(3D)hybrid architecture(CuO-Co_(3)O_(4)-RGO),which are successfully...Hybrid CuO-Co_(3)O_(4)nanosphere building blocks have been embedded between the layered nanosheets of reduced graphene oxides with a three dimensional(3D)hybrid architecture(CuO-Co_(3)O_(4)-RGO),which are successfully applied as enhanced anodes for lithium-ion batteries(LIBs).The CuO-Co_(3)O_(4)-RGO sandwiched nanostructures exhibit a reversible capacity of~847 mA·h·g^(-1)after 200 cycles’cycling at 100 mA·g^(-1)with a capacity retention of 79%.The CuO-Co_(3)O_(4)-RGO compounds show superior electrochemical properties than the comparative CuO-Co_(3)O_(4),Co_(3)O_(4)and CuO anodes,which may be ascribed to the following reasons:the hybridizing multicomponent can probably give the complementary advantages;the mutual benefit of uniformly distributing nanospheres across the layered RGO nanosheets can avoid the agglomeration of both the RGO nanosheets and the CuO-Co_(3)O_(4) nanospheres;the 3D storage structure as well as the graphene wrapped composite could enhance the electrical conductivity and reduce volume expansion effect associated with the discharge-charge process.展开更多
The isolated inorganic particles within composite polymer electrolytes(CPEs) are not correlated to the Li^(+)transfer network,resulting in the polymer dominating the low ionic conductivity of CPEs.Therefore,we develop...The isolated inorganic particles within composite polymer electrolytes(CPEs) are not correlated to the Li^(+)transfer network,resulting in the polymer dominating the low ionic conductivity of CPEs.Therefore,we developed novel quasi-solid-state CPEs of a Ce-doped Na super ion conductors(NASICON)Na_(1.3+x)Al_(0.3)Ce_(x)Ti_(1.7-x)(PO_(4))_(3)(NCATP) chemically coupled poly(vinylidene fluoride-hexafluoropropylene)(PVDF-HFP)/Li-bis(trifluoromethanes-ulfonyl)imide(LiTFSI) matrix.A strong interaction between Ce^(3+)from NCATP and TFSI-anion from the polymer matrix contributes to the fast Li+transportation at the interface.The PVDF-HFP/NCATP CPEs exhibit an ionic conductivity of 2.16 × 0^(-3) S cm^(-1) and a Li^(+) transference number of 0.88.A symmetric Li/Li cell with NCATP-integrated CPEs at 0.1 mA cm^(-2) presents outstanding cycling stability over 2000 h at 25℃.The quasi-solid-state Li metal batteries of Li/CPEs/LiFePO_(4) at 2 C after 400 cycles and Li/CPEs/LiCoO_(2) at 0.2 C after 120 cycles deliver capacities of 100 and 152 mAh g^(-1) at 25℃,respectively.展开更多
Novel SiO_(2)-LiBr microcapsules for water-retaining pavement were prepared and firstly characterized by scanning electron microscope(SEM),particle size analysis,and Fourier transform infrared spectroscopy(FT-IR).The ...Novel SiO_(2)-LiBr microcapsules for water-retaining pavement were prepared and firstly characterized by scanning electron microscope(SEM),particle size analysis,and Fourier transform infrared spectroscopy(FT-IR).The water vapor sorption and desorption of the formulated microcapsules was then experimentally studied using dynamic vapor sorption(DVS),with the results fitted to three kinds of adsorption kinetics models.In addition,the specific surface area(SSA)was also calculated based on BET theory;and the thermal performance was investigated by laser flash analysis(LFA).Experimental results show a change of 103%in mass of the microcapsule sample under 90%relative humidity(RH)at 30℃after water vapor sorption.The fitting of results indicates that the adsorption process is mainly governed by the intra-particle diffusion mechanism,followed by the pseudo-first-order adsorption process.In comparison with most conventional pavement materials,it is found that the SSA of the formulated microcapsules is much larger while the thermal conductivity is lower.The unique properties of the formulated SiO_(2)-LiBr microcapsules have significant potential to take the edge off the urban heat island effect and reduce rutting when applied to water-retaining pavement materials.展开更多
[ Objective] The aim was to study the control effect of different sex pheromones and trapping lamps against main pests in tobacco. [ Method] Control effect of sex pheromone of different matrix lures and Jiaduo trappin...[ Objective] The aim was to study the control effect of different sex pheromones and trapping lamps against main pests in tobacco. [ Method] Control effect of sex pheromone of different matrix lures and Jiaduo trapping lamp against Spodoptern litura, Helicoverpa assulta and Helicoverpa armigera in tobacco in Teng- chong of Yunnan were determined and compared, and the control cast was evaluated. [Result] The use of insect sex pheromones and insecticidal light traps had certain effect against S. litura and H. armiger. The trapping effect of sex pheromone traps was better than that of Jiaduo trapping lamp, and the PVC matrix lure had better performance than rubber matrix lure, which had strongest capturing capacity, continuous control effect and significant effort against S. litura. The traps with different settled densities and hanging heights also had different trapping effect against S. litura and H. armiger, and the hanging height of 100 - 150 cm from ground was the best; as the cost was considered, the cast of the area with low density of traps was the lowest, which was reduced by over 44% than conventional chemical control area. [ Conclusion] It is safe and effective to use sex pheromone and insecticidal light traps to control S. litura and H. armigera, and it is a green environmental protection biological physical control technology, having extended application prospect in large area.展开更多
The electronic properties and transport properties of MoTe2/SnS2 heterostructure Tunneling FETs are investigated by the density functional theory coupled with non-equilibrium Green’s function method.Two dimensional(2...The electronic properties and transport properties of MoTe2/SnS2 heterostructure Tunneling FETs are investigated by the density functional theory coupled with non-equilibrium Green’s function method.Two dimensional(2D)monolayer MoTe2 and SnS2 are combined to a vertical van der Waals heterojunction.A small staggered band gap is formed in the overlap region,while larger gaps remain in the underlap source and drain regions of monolayer MoTe2 and SnS2 respectively.Such a type-II heterojunction is favorable for tunneling FET.Furthermore,we suggest short stack length and large gate-to-drain overlap to enhance the on-state current suppress the leakage current respectively.The numerical results show that at a low drain to source voltage Vds=0.05V,On/Off current ratio can reach 108 and the On-state currents is over 20μA/μm for ntype devices.Our results present that van der Waals heterostructure TFETs can be potential candidate as next generation ultra-steep subthreshold and low-power electronic applications.展开更多
Rechargeable zinc-air batteries(ZABs)are a promising energy conversion device,which rely critically on electrocatalysts to accelerate their rate-determining reactions such as oxygen reduction(ORR)and oxygen evolution ...Rechargeable zinc-air batteries(ZABs)are a promising energy conversion device,which rely critically on electrocatalysts to accelerate their rate-determining reactions such as oxygen reduction(ORR)and oxygen evolution reactions(OER).Herein,we fabricate a range of bifunctional M-N-C(metal-nitrogen-carbon)catalysts containing M-Nx coordination sites and M/MxC nanoparticles(M=Co,Fe,and Cu)using a new class ofγ-cyclodextrin(CD)based metal-organic framework as the precursor.With the two types of active sites interacting with each other in the catalysts,the obtained Fe@C-FeNC and Co@C-CoNC display superior alkaline ORR activity in terms of low half-wave(E1/2)potential(~0.917 and 0.906 V,respectively),which are higher than Cu@C-CuNC(~0.829 V)and the commercial Pt/C(~0.861 V).As a bifunctional electrocatalyst,the Co@C-CoNC exhibits the best performance,showing a bifunctional ORR/OER overpotential(ΔE)of~0.732 V,which is much lower than that of Fe@C-FeNC(~0.831 V)and Cu@C-CuNC(~1.411 V),as well as most of the robust bifunctional electrocatalysts reported to date.Synchrotron X-ray absorption spectroscopy and density functional theory simulations reveal that the strong electronic correlation between metallic Co nanoparticles and the atomic Co-N4 sites in the Co@C-CoNC catalyst can increase the d-electron density near the Fermi level and thus effectively optimize the adsorption/desorption of intermediates in ORR/OER,resulting in an enhanced bifunctional electrocatalytic performance.The Co@C-CoNC-based rechargeable ZAB exhibited a maximum power density of 162.80 mW cm^(−2) at 270.30 mA cm^(−2),higher than the combination of commercial Pt/C+RuO2(~158.90 mW cm^(−2) at 265.80 mA cm^(−2))catalysts.During the galvanostatic discharge at 10 mA cm^(−2),the ZAB delivered an almost stable discharge voltage of 1.2 V for~140 h,signifying the virtue of excellent bifunctional ORR/OER electrocatalytic activity.展开更多
Glabridin is the main ingredient of hydrophobic fraction in licorice extract and has been shown to have anti-melanogenesis activity in skins.However,the underlying mechanism(s)remain not completely understood.The aim ...Glabridin is the main ingredient of hydrophobic fraction in licorice extract and has been shown to have anti-melanogenesis activity in skins.However,the underlying mechanism(s)remain not completely understood.The aim of this study is thus to elucidate the possible mechanisms related to the melanogenesis suppression by glabridin in cultured B16 murine melanoma cells and in UVA radiation induced hyperpigmentation model of BALB/c mice as well.Molecular docking simulations revealed that between catalytic core residues and the compound.The treatment by glabridin significantly downregulated both transcriptional and/or protein expression of melanogenesis-related factors including melanocyte stimulating hormone receptor(MC1R),microphthalmia-associated transcription factor(MITF),tyrosinase(TYR),TYR-related protein-1(TRP-1)and TRP-2 in B16 cells.Both PKA/MITF and MAPK/MITF signaling pathways were found to be involved in the suppression of melanogenesis by glabridin in B16 cells.Also in vivo glabridin therapy significantly reduced hyperpigmentation,epidermal thickening,roughness and inflammation induced by frequent UVA exposure in mice skins,thus beneficial for skin healthcare.These data further look insights into the molecular mechanisms of melanogenesis suppression by glabridin,rationalizing the application of the natural compound for skin healthcare.展开更多
A fuel cell is an energy conversion device that can continuously input fuel and oxidant into the device through an electrochemical reaction to release electrical energy.Although noble metals show good activity in fuel...A fuel cell is an energy conversion device that can continuously input fuel and oxidant into the device through an electrochemical reaction to release electrical energy.Although noble metals show good activity in fuel cell-related electrochemical reactions,their ever-increasing price considerably hinders their industrial application.Improvement of atom utilization efficiency is considered one of the most effective strategies to improve the mass activity of catalysts,and this allows for the use of fewer catalysts,saving greatly on the cost.Thus,single-atom catalysts(SACs)with an atom utilization efficiency of 100%have been widely developed,which show remarkable performance in fuel cells.In this review,we will describe recent progress on the development of SACs for membrane electrode assembly of fuel cell applications.First,we will introduce several effective routes for the synthesis of SACs.The reaction mechanism of the involved reactions will also be introduced as it is highly determinant of the final activity.Then,we will systematically summarize the application of Pt group metal(PGM)and nonprecious group metal(non-PGM)catalysts in membrane electrode assembly of fuel cells.This review will offer numerous experiences for developing potential industrialized fuel cell catalysts in the future.展开更多
Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the pathogen responsible for coronavirus disease 2019(COVID-19),continues to evolve,giving rise to more variants and global reinfections.Previous research ha...Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the pathogen responsible for coronavirus disease 2019(COVID-19),continues to evolve,giving rise to more variants and global reinfections.Previous research has demonstrated that barcode segments can effectively and cost-efficiently identify specific species within closely related populations.In this study,we designed and tested RNA barcode segments based on genetic evolutionary relationships to facilitate the efficient and accurate identification of SARS-CoV-2 from extensive virus samples,including human coronaviruses(HCoVs)and SARSr-CoV-2 lineages.Nucleotide sequences sourced from NCBI and GISAID were meticulously selected and curated to construct training sets,encompassing 1733 complete genome sequences of HCoVs and SARSr-CoV-2 lineages.Through genetic-level species testing,we validated the accuracy and reliability of the barcode segments for identifying SARS-CoV-2.Subsequently,75 main and subordinate species-specific barcode segments for SARS-CoV-2,located in ORF1ab,S,E,ORF7a,and N coding sequences,were intercepted and screened based on single-nucleotide polymorphism sites and weighted scores.Post-testing,these segments exhibited high recall rates(nearly 100%),specificity(almost 30%at the nucleotide level),and precision(100%)performance on identification.They were eventually visualized using one and two-dimensional combined barcodes and deposited in an online database(http://virusbarcodedatabase.top/).The successful integration of barcoding technology in SARS-CoV-2 identification provides valuable insights for future studies involving complete genome sequence polymorphism analysis.Moreover,this cost-effective and efficient identification approach also provides valuable reference for future research endeavors related to virus surveillance.展开更多
There is great variation in the lithology and lamination thickness of composite roof in coal-measure strata;thus,the roof is prone to delamination and falling,and it is difficult to control the surrounding rock when d...There is great variation in the lithology and lamination thickness of composite roof in coal-measure strata;thus,the roof is prone to delamination and falling,and it is difficult to control the surrounding rock when developing roadway in such rock strata.In deep mining,the stress environment of surrounding rock is complex,and the mechanical response of the rock mass is different from that of the shallow rock mass.For composite-roof roadway excavated in deep rock mass,the key to safe and efficient production of the mine is ensuring the stability of the roadway.The present paper obtains typical failure characteristics and deformation and failure mechanisms of composite-roof roadway with a buried depth of 650 m at Zhaozhuang Coal Mine(Shanxi Province,China).On the basis of determining a reasonable cross-section shape of the roadway and according to the failure characteristics of the composite roof in different regions,the roof is divided into an unstable layer,metastable layer,and stable layer.The controlled unstable layer and metastable layer are regarded as a small structure while the stable layer is regarded as a large structure.A superimposed coupling support technology of large and small structures with a multi-level prestressed bearing arch formed by strong rebar bolts and highly prestressed cable bolts is put forward.The support technology provides good application results in the field.The study thus provides theoretical support and technical guidance for ground control under similar geological conditions.展开更多
A dynamic modeling framework based on an intelligent approach is proposed to identify the complex behaviors of solid-gas sorption systems.An experimental system was built and tested to assist in developing a model of ...A dynamic modeling framework based on an intelligent approach is proposed to identify the complex behaviors of solid-gas sorption systems.An experimental system was built and tested to assist in developing a model of the system performance during the adsorption and desorption processes.The variations in the thermal effects and gaseous environment accompanying the reactions were considered when designing the model.An optimization platform based on a multi-population genetic algorithm and artificial criteria was established to identify the mod-eling coefficients and quantify the effects of condition changes on the reactions.The calibration of the simulation results against the tested data showed good accuracy,where the coefficient of determination was greater than 0.988.The outcome of this study could provide a modeling basis for the optimization of solid-gas sorption systems and contribute a potential tool for uncovering key characteristics associated with materials and components.展开更多
The strong intrinsic Coulomb interactions of Frenkel excitons in crystalline carbon nitride(CCN) greatly limits their dissociation into electrons and holes, resulting in unsatisfactory charges separation and photocata...The strong intrinsic Coulomb interactions of Frenkel excitons in crystalline carbon nitride(CCN) greatly limits their dissociation into electrons and holes, resulting in unsatisfactory charges separation and photocatalytic efficiency. Herein, we propose a strategy to facilitate excitons dissociation by molecular regulation induced built-in electric field(BIEF). The electron-rich pyrimidine-ring into CCN changes the charge density distribution over heptazine-rings to induce BIEF between melon chains. Such BIEF is sufficient to overcome the considerable exciton binding energy(EBE) and reduce it from 38.4 meV to 16.4 meV,increasing the excitons dissociation efficiency(EDE) from 21.5% to 51.9%. Our results establish a strategy to facilitate excitons dissociation through molecular regulation induced BIEF, targeting the intrinsic high EBE and low EDE of polymer photocatalysts.展开更多
The key to develop high specific energy rechargeable batteries is development of new electrode materials.The existing electrode materials still have many problems:the shuttle effect and poor conductivity of the sulfur...The key to develop high specific energy rechargeable batteries is development of new electrode materials.The existing electrode materials still have many problems:the shuttle effect and poor conductivity of the sulfur cathode,the inevitable volume expansion of the silicon anode and the lithium dendrite of the lithium metal anode that cause short circuits,etc.Nanofibers,as active electrical materials,conductive additives and electrode bodies,can play multiple roles in electrode design.More interestingly,nanofibers can be functionalized to obtain better controllable properties(i.e.,electrolyte affinity,pore size distribution and surface electronic structure),thereby further enhancing electrochemical performance.In this article,the latest research progress in electrode design based on nanofibers is reviewed,including processing methods,structure,morphology and electrochemical performance.The key problems affecting the electrochemical performance of the electrode are also discussed,such as the preparation process,atomic structure,electrical conductivity,surface area and pore distribution of nanofibers,to provide reference points for nanofibers in excellent electrode design.展开更多
Carbon capture is widely recognised as an essential strategy to meet global goals for climate protection.Although various C02 capture technologies including absorption,adsorption and membrane exist,they are not yet ma...Carbon capture is widely recognised as an essential strategy to meet global goals for climate protection.Although various C02 capture technologies including absorption,adsorption and membrane exist,they are not yet mature for post-combustion power plants mainly due to high energy penalty.Hence researchers are concentrating on developing non-aqueous solvents like ionic liquids,C 02-binding organic liquids,nanoparticle hybrid materials and microencapsulated sorbents to minimize the energy consumption for carbon capture.This research aims to develop a novel and efficient approach by encapsulating sorbents to capture C02 in a cold environment.The conventional emulsion technique was selected for the microcapsule formulation by using 2-amino-2-methyl-l-propanol(AMP)as the core sorbent and silicon dioxide as the shell.This paper reports the findings on the formulated microcapsules including key formulation parameters,microstructure,size distribution and thermal cycling stability.Furthermore,the effects of microcapsule quality and absorption temperature on the C02 loading capacity of the microcapsules were investigated using a self-developed pressure decay method.The preliminary results have shown that the AMP microcapsules are promising to replace conventional sorbents.展开更多
Light regulation devices are essential for signal modulation, information encryption and energy-saving smart windows. Recently, due to their excellent stimuli-responsive properties, lead halide perovskites have shown ...Light regulation devices are essential for signal modulation, information encryption and energy-saving smart windows. Recently, due to their excellent stimuli-responsive properties, lead halide perovskites have shown great potential. However, the high transition temperature, irreversibility of the phase transition and toxicity of heavy metals make perovskite materials unsuitable for devices related to human activity. Herein, for the first time, a flexible perovskite nano-network is proposed and its application as a smart window is demonstrated. The perovskite-sodium alginate(SA) nano-network showed a 31.6 ℃(20% RH) transition temperature and stability over 1200 cycles. The hydrophobic surface and the “eggbox” structure formed by SA make that the lead leakage is only 2.569 ppb, which is much higher than the drinking water standard. This work provides a successful demonstration for energy-efcient buildings and inspires future nontoxic perovskite-based devices through heavy metal control.展开更多
基金financially supported by the National Natural Science Foundation of China(No.22372103)Guangdong Basic and Applied Basic Research Foundation,China(2021A1515010241,2024A1515010032)the Shenzhen Science and Technology Foundation,China(JCYJ20220531103216037)。
文摘Although lithium-sulfur batteries(LSBs)exhibit high theoretical energy density,their practical application is hindered by poor conductivity of the sulfur cathode,the shuttle effect,and the irreversible deposition of Li_(2)S.To address these issues,a novel composite,using electrospinning technology,consisting of Fe_(3)Se_(4)and porous nitrogen-doped carbon nanofibers was designed for the interlayer of LSBs.The porous carbon nanofiber structure facilitates the transport of ions and electrons,while the Fe_(3)Se_(4)material adsorbs lithium polysulfides(LiPSs)and accelerates its catalytic conversion process.Furthermore,the Fe_(3)Se_(4)material interacts with soluble LiPSs to generate a new polysulfide intermediate,Li_(x)FeS_(y)complex,which changes the electrochemical reaction pathway and facilitates the three-dimensional deposition of Li_(2)S,enhancing the reversibility of LSBs.The designed LSB demonstrates a high specific capacity of1529.6 mA h g^(-1)in the first cycle at 0.2 C.The rate performance is also excellent,maintaining an ultra-high specific capacity of 779.7 mA h g^(-1)at a high rate of 8 C.This investigation explores the mechanism of the interaction between the interlayer and LiPSs,and provides a new strategy to regulate the reaction kinetics and Li_(2)S deposition in LSBs.
基金financially supported by the National Natural Science Foundation of China(No.52174095)the Top Innovative Talents Cultivation Fund for Doctoral Postgraduates(No.BBJ2023054).
文摘Using aeolian sand(AS)for goaf backfilling allows coordination of green mining and AS control.Cemented AS backfill(CASB)exhibits brittle fracture.Polypropylene(PP)fibers are good toughening materials.When the toughening effect of fibers is analyzed,their influence on the slurry conveying performance should also be considered.Additionally,cement affects the interactions among the hydration products,fibers,and aggregates.In this study,the effects of cement content(8wt%,9wt%,and 10wt%)and PP fiber length(6,9,and 12 mm)and dosage(0.05wt%,0.1wt%,0.15wt%,0.2wt%,and 0.25wt%)on fluidity and mechanical properties of the fibertoughened CASB(FCASB)were analyzed.The results indicated that with increases in the three aforementioned factors,the slump flow decreased,while the rheological parameters increased.Uniaxial compressive strength(UCS)increased with the increase of cement content and fiber length,and with an increase in fiber dosage,it first increased and then decreased.The strain increased with the increase of fiber dosage and length.The effect of PP fibers became more pronounced with the increase of cement content.Digital image correlation(DIC)test results showed that the addition of fibers can restrain the peeling of blocks and the expansion of fissure,and reduce the stress concentration of the FCASB.Scanning electron microscopy(SEM)test indicated that the functional mechanisms of fibers mainly involved the interactions of fibers with the hydration products and matrix and the spatial distribution of fibers.On the basis of single-factor analysis,the response surface method(RSM)was used to analyze the effects of the three aforementioned factors and their interaction terms on the UCS.The influence surface of the two-factor interaction terms and the three-dimensional scatter plot of the three-factor coupling were established.In conclusion,the response law of the FCASB properties under the effects of cement and PP fibers were obtained,which provides theoretical and engineering guidance for FCASB filling.
基金the National Natural Science Foundation of China(No.52325208)the Fundamental Research Funds for the Central Universities(No.06500174)National Key Research and Development Program of China(No.2022YFB3807401)。
文摘Nonreciprocity of thermal metamaterials has significant application prospects in isolation protection,unidirectional transmission,and energy harvesting.However,due to the inherent isotropic diffusion law of heat flow,it is extremely difficult to achieve nonreciprocity of heat transfer.This review presents the recent developments in thermal nonreciprocity and explores the fundamental theories,which underpin the design of nonreciprocal thermal metamaterials,i.e.,the Onsager reciprocity theorem.Next,three methods for achieving nonreciprocal metamaterials in the thermal field are elucidated,namely,nonlinearity,spatiotemporal modulation,and angular momentum bias,and the applications of nonreciprocal thermal metamaterials are outlined.We also discuss nonreciprocal thermal radiation.Moreover,the potential applications of nonreciprocity to other Laplacian physical fields are discussed.Finally,the prospects for advancing nonreciprocal thermal metamaterials are highlighted,including developments in device design and manufacturing techniques and machine learning-assisted material design.
基金funded by the National Key Research and Development Program of China(no.2020YFC1909604)Shenzhen Key Projects of Technological Research(JSGG20200925145800001)Shenzhen Basic Research Project(no.JCYJ20190808145203535).
文摘This work demonstrates a novel polymerization-derived polymer electrolyte consisting of methyl methacrylate,lithium bis(trifluoromethanesulfonyl)imide and fluoroethylene carbonate.The polymerization of MMA was initiated by the amino compounds following an anionic catalytic mechanism.LiTFSI plays both roles including the initiator and Li ion source in the polymer electrolyte.Normally,lithium bis(trifluoromethanesulfonyl)imide has difficulty in initiating the polymerization reaction of methyl methacrylate monomer,a very high concentration of lithium bis(trifluoromethanesulfonyl)imide is needed for initiating the polymerization.However,the fluoroethylene carbonate additive can work as a supporter to facilitate the degree of dissociation of lithium bis(trifluoromethanesulfonyl)imide and increase its initiator capacity due to the high dielectric constant.The as-prepared poly-methyl methacrylate-based polymer electrolyte has a high ionic conductivity(1.19×10^(−3)S cm^(−1)),a wide electrochemical stability window(5 V vs Li^(+)/Li),and a high Li ion transference number(t_(Li^(+)))of 0.74 at room temperature(RT).Moreover,this polymerization-derived polymer electrolyte can effectively work as an artificial protective layer on Li metal anode,which enabled the Li symmetric cell to achieve a long-term cycling performance at 0.2 mAh cm^(−2)for 2800 h.The LiFePO_(4)battery with polymerization-derived polymer electrolyte-modified Li metal anode shows a capacity retention of 91.17%after 800 cycles at 0.5 C.This work provides a facile and accessible approach to manufacturing poly-methyl methacrylate-based polymerization-derived polymer electrolyte and shows great potential as an interphase in Li metal batteries.
基金financially supported by the National Natural Science Foundation of China (NO.52174095)。
文摘The use of aeolian sand(AS)as an aggregate to prepare coal mine cemented filling materials can resolve the problems of gangue shortage and excessive AS deposits.Owing to the lack of research on the mechanism of cemented AS backfill(CASB),the response surface method(RSM)was adopted in this study to analyze the influence of ordinary Portland cement(PO)content(x_(1)),fly ash(FA)-AS(FA-AS)ratio(x_(2)),and concentration(x_(3))on the mechanical and microscopic properties of the CASB.The hydration characteristics and internal pore structure of the backfill were assessed through thermogravimetric/derivative thermogravimetric analysis,mercury intrusion porosimetry,and scanning electron microscopy.The RSM results show that the influence of each factor and interaction term on the response values is extremely significant(except x_(1)x_(3),which had no obvious effect on the 28 d strength).The uniaxial compressive strength(UCS)increased with the PO content,FA-AS ratio,and concentration.The interaction effects of x_(1)x_(2),x_(1)x_(3),and x_(2)x_(3) on the UCS at 3,7,and 28 d were analyzed.In terms of the influence of interaction items,an improvement in one factor promoted the strengthening effect of another factor.The enhancement mechanism of the curing time,PO content,and FA-AS ratio on the backfill was reflected in the increase in hydration products and pore structure optimization.By contrast,the enhancement mechanism of the concentration was mainly the pore structure optimization.The UCS was positively correlated with weight loss and micropore content but negatively correlated with the total porosity.The R^(2) value of the fitting function of the strength and weight loss,micropore content,and total porosity exceeded 0.9,which improved the characterization of the enhancement mechanism of the UCS based on the thermogravimetric analysis and pore structure.This work obtained that the influence rules and mechanisms of the PO,FA-AS,concentration,and interaction terms on the mechanical properties of the CASB provided a certain theoretical and engineering guidance for CASB filling.
基金financially supported by the National Natural Science Foundation of China (21471100, 22005199)the Shenzhen Natural Science Fundation (20200813081943001)the Natural Science Foundation of Guangdong Province,China(2021A1515010241, 2021A1515010142)
文摘Hybrid CuO-Co_(3)O_(4)nanosphere building blocks have been embedded between the layered nanosheets of reduced graphene oxides with a three dimensional(3D)hybrid architecture(CuO-Co_(3)O_(4)-RGO),which are successfully applied as enhanced anodes for lithium-ion batteries(LIBs).The CuO-Co_(3)O_(4)-RGO sandwiched nanostructures exhibit a reversible capacity of~847 mA·h·g^(-1)after 200 cycles’cycling at 100 mA·g^(-1)with a capacity retention of 79%.The CuO-Co_(3)O_(4)-RGO compounds show superior electrochemical properties than the comparative CuO-Co_(3)O_(4),Co_(3)O_(4)and CuO anodes,which may be ascribed to the following reasons:the hybridizing multicomponent can probably give the complementary advantages;the mutual benefit of uniformly distributing nanospheres across the layered RGO nanosheets can avoid the agglomeration of both the RGO nanosheets and the CuO-Co_(3)O_(4) nanospheres;the 3D storage structure as well as the graphene wrapped composite could enhance the electrical conductivity and reduce volume expansion effect associated with the discharge-charge process.
基金the National Key Research and Development Program of China (No. 2020YFC1909604)the Shenzhen Key Projects of Technological Research (JSGG2020092514 5800001)。
文摘The isolated inorganic particles within composite polymer electrolytes(CPEs) are not correlated to the Li^(+)transfer network,resulting in the polymer dominating the low ionic conductivity of CPEs.Therefore,we developed novel quasi-solid-state CPEs of a Ce-doped Na super ion conductors(NASICON)Na_(1.3+x)Al_(0.3)Ce_(x)Ti_(1.7-x)(PO_(4))_(3)(NCATP) chemically coupled poly(vinylidene fluoride-hexafluoropropylene)(PVDF-HFP)/Li-bis(trifluoromethanes-ulfonyl)imide(LiTFSI) matrix.A strong interaction between Ce^(3+)from NCATP and TFSI-anion from the polymer matrix contributes to the fast Li+transportation at the interface.The PVDF-HFP/NCATP CPEs exhibit an ionic conductivity of 2.16 × 0^(-3) S cm^(-1) and a Li^(+) transference number of 0.88.A symmetric Li/Li cell with NCATP-integrated CPEs at 0.1 mA cm^(-2) presents outstanding cycling stability over 2000 h at 25℃.The quasi-solid-state Li metal batteries of Li/CPEs/LiFePO_(4) at 2 C after 400 cycles and Li/CPEs/LiCoO_(2) at 0.2 C after 120 cycles deliver capacities of 100 and 152 mAh g^(-1) at 25℃,respectively.
基金financial support of The National Scholarship Foundation of China,China Scholarship Council([2018]3101)。
文摘Novel SiO_(2)-LiBr microcapsules for water-retaining pavement were prepared and firstly characterized by scanning electron microscope(SEM),particle size analysis,and Fourier transform infrared spectroscopy(FT-IR).The water vapor sorption and desorption of the formulated microcapsules was then experimentally studied using dynamic vapor sorption(DVS),with the results fitted to three kinds of adsorption kinetics models.In addition,the specific surface area(SSA)was also calculated based on BET theory;and the thermal performance was investigated by laser flash analysis(LFA).Experimental results show a change of 103%in mass of the microcapsule sample under 90%relative humidity(RH)at 30℃after water vapor sorption.The fitting of results indicates that the adsorption process is mainly governed by the intra-particle diffusion mechanism,followed by the pseudo-first-order adsorption process.In comparison with most conventional pavement materials,it is found that the SSA of the formulated microcapsules is much larger while the thermal conductivity is lower.The unique properties of the formulated SiO_(2)-LiBr microcapsules have significant potential to take the edge off the urban heat island effect and reduce rutting when applied to water-retaining pavement materials.
基金Supported by Key Project of China National Tobacco Company ( 110201202015)Project of Yunnan Tobacco Company ( 2012YN11)
文摘[ Objective] The aim was to study the control effect of different sex pheromones and trapping lamps against main pests in tobacco. [ Method] Control effect of sex pheromone of different matrix lures and Jiaduo trapping lamp against Spodoptern litura, Helicoverpa assulta and Helicoverpa armigera in tobacco in Teng- chong of Yunnan were determined and compared, and the control cast was evaluated. [Result] The use of insect sex pheromones and insecticidal light traps had certain effect against S. litura and H. armiger. The trapping effect of sex pheromone traps was better than that of Jiaduo trapping lamp, and the PVC matrix lure had better performance than rubber matrix lure, which had strongest capturing capacity, continuous control effect and significant effort against S. litura. The traps with different settled densities and hanging heights also had different trapping effect against S. litura and H. armiger, and the hanging height of 100 - 150 cm from ground was the best; as the cost was considered, the cast of the area with low density of traps was the lowest, which was reduced by over 44% than conventional chemical control area. [ Conclusion] It is safe and effective to use sex pheromone and insecticidal light traps to control S. litura and H. armigera, and it is a green environmental protection biological physical control technology, having extended application prospect in large area.
基金the Training Program of the Major Research Plan of the National Natural Science Foundation of China(61774168,91964103)and the MOST(2016YFA0202300).
文摘The electronic properties and transport properties of MoTe2/SnS2 heterostructure Tunneling FETs are investigated by the density functional theory coupled with non-equilibrium Green’s function method.Two dimensional(2D)monolayer MoTe2 and SnS2 are combined to a vertical van der Waals heterojunction.A small staggered band gap is formed in the overlap region,while larger gaps remain in the underlap source and drain regions of monolayer MoTe2 and SnS2 respectively.Such a type-II heterojunction is favorable for tunneling FET.Furthermore,we suggest short stack length and large gate-to-drain overlap to enhance the on-state current suppress the leakage current respectively.The numerical results show that at a low drain to source voltage Vds=0.05V,On/Off current ratio can reach 108 and the On-state currents is over 20μA/μm for ntype devices.Our results present that van der Waals heterostructure TFETs can be potential candidate as next generation ultra-steep subthreshold and low-power electronic applications.
基金supported by the Shenzhen Government’s Plan of Science and Technology(JCYJ20190808121407676 and 20200813142301001)National Natural Science Foundation of China(22178223 and 22262010)+1 种基金Guangxi Science and Technology Fund for Distinguished High-Talent Introduction Program(No.RZ2200002233AC22035091).
文摘Rechargeable zinc-air batteries(ZABs)are a promising energy conversion device,which rely critically on electrocatalysts to accelerate their rate-determining reactions such as oxygen reduction(ORR)and oxygen evolution reactions(OER).Herein,we fabricate a range of bifunctional M-N-C(metal-nitrogen-carbon)catalysts containing M-Nx coordination sites and M/MxC nanoparticles(M=Co,Fe,and Cu)using a new class ofγ-cyclodextrin(CD)based metal-organic framework as the precursor.With the two types of active sites interacting with each other in the catalysts,the obtained Fe@C-FeNC and Co@C-CoNC display superior alkaline ORR activity in terms of low half-wave(E1/2)potential(~0.917 and 0.906 V,respectively),which are higher than Cu@C-CuNC(~0.829 V)and the commercial Pt/C(~0.861 V).As a bifunctional electrocatalyst,the Co@C-CoNC exhibits the best performance,showing a bifunctional ORR/OER overpotential(ΔE)of~0.732 V,which is much lower than that of Fe@C-FeNC(~0.831 V)and Cu@C-CuNC(~1.411 V),as well as most of the robust bifunctional electrocatalysts reported to date.Synchrotron X-ray absorption spectroscopy and density functional theory simulations reveal that the strong electronic correlation between metallic Co nanoparticles and the atomic Co-N4 sites in the Co@C-CoNC catalyst can increase the d-electron density near the Fermi level and thus effectively optimize the adsorption/desorption of intermediates in ORR/OER,resulting in an enhanced bifunctional electrocatalytic performance.The Co@C-CoNC-based rechargeable ZAB exhibited a maximum power density of 162.80 mW cm^(−2) at 270.30 mA cm^(−2),higher than the combination of commercial Pt/C+RuO2(~158.90 mW cm^(−2) at 265.80 mA cm^(−2))catalysts.During the galvanostatic discharge at 10 mA cm^(−2),the ZAB delivered an almost stable discharge voltage of 1.2 V for~140 h,signifying the virtue of excellent bifunctional ORR/OER electrocatalytic activity.
基金supported by the Inner Mongolia Autonomous Region Science and Technology Revitalization Foundation (2021CG0029)the National Natural Science Foundation of China (22178070)
文摘Glabridin is the main ingredient of hydrophobic fraction in licorice extract and has been shown to have anti-melanogenesis activity in skins.However,the underlying mechanism(s)remain not completely understood.The aim of this study is thus to elucidate the possible mechanisms related to the melanogenesis suppression by glabridin in cultured B16 murine melanoma cells and in UVA radiation induced hyperpigmentation model of BALB/c mice as well.Molecular docking simulations revealed that between catalytic core residues and the compound.The treatment by glabridin significantly downregulated both transcriptional and/or protein expression of melanogenesis-related factors including melanocyte stimulating hormone receptor(MC1R),microphthalmia-associated transcription factor(MITF),tyrosinase(TYR),TYR-related protein-1(TRP-1)and TRP-2 in B16 cells.Both PKA/MITF and MAPK/MITF signaling pathways were found to be involved in the suppression of melanogenesis by glabridin in B16 cells.Also in vivo glabridin therapy significantly reduced hyperpigmentation,epidermal thickening,roughness and inflammation induced by frequent UVA exposure in mice skins,thus beneficial for skin healthcare.These data further look insights into the molecular mechanisms of melanogenesis suppression by glabridin,rationalizing the application of the natural compound for skin healthcare.
基金National Natural Science Foundation of China,Grant/Award Numbers:22075203,22279079,21905179Guangdong Science and Technology Department Program,Grant/Award Number:2021QN02L252+1 种基金Shenzhen Science and Technology Department Program,Grant/Award Numbers:20220810133521001,20220809165014001Natural Science Foundation of SZU,Grant/Award Numbers:000002111605,000002112215。
文摘A fuel cell is an energy conversion device that can continuously input fuel and oxidant into the device through an electrochemical reaction to release electrical energy.Although noble metals show good activity in fuel cell-related electrochemical reactions,their ever-increasing price considerably hinders their industrial application.Improvement of atom utilization efficiency is considered one of the most effective strategies to improve the mass activity of catalysts,and this allows for the use of fewer catalysts,saving greatly on the cost.Thus,single-atom catalysts(SACs)with an atom utilization efficiency of 100%have been widely developed,which show remarkable performance in fuel cells.In this review,we will describe recent progress on the development of SACs for membrane electrode assembly of fuel cell applications.First,we will introduce several effective routes for the synthesis of SACs.The reaction mechanism of the involved reactions will also be introduced as it is highly determinant of the final activity.Then,we will systematically summarize the application of Pt group metal(PGM)and nonprecious group metal(non-PGM)catalysts in membrane electrode assembly of fuel cells.This review will offer numerous experiences for developing potential industrialized fuel cell catalysts in the future.
基金supported by grants from Key Research&Development Project of Nanhua Biomedical Co.,Ltd.(No.H202191490139)National Natural Science Foundation of China(No.31872866)+1 种基金China Postdoctoral Science Foundation(Nos.2021M701160 and 2022M721101)Funds of Hunan university(521119400156).
文摘Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the pathogen responsible for coronavirus disease 2019(COVID-19),continues to evolve,giving rise to more variants and global reinfections.Previous research has demonstrated that barcode segments can effectively and cost-efficiently identify specific species within closely related populations.In this study,we designed and tested RNA barcode segments based on genetic evolutionary relationships to facilitate the efficient and accurate identification of SARS-CoV-2 from extensive virus samples,including human coronaviruses(HCoVs)and SARSr-CoV-2 lineages.Nucleotide sequences sourced from NCBI and GISAID were meticulously selected and curated to construct training sets,encompassing 1733 complete genome sequences of HCoVs and SARSr-CoV-2 lineages.Through genetic-level species testing,we validated the accuracy and reliability of the barcode segments for identifying SARS-CoV-2.Subsequently,75 main and subordinate species-specific barcode segments for SARS-CoV-2,located in ORF1ab,S,E,ORF7a,and N coding sequences,were intercepted and screened based on single-nucleotide polymorphism sites and weighted scores.Post-testing,these segments exhibited high recall rates(nearly 100%),specificity(almost 30%at the nucleotide level),and precision(100%)performance on identification.They were eventually visualized using one and two-dimensional combined barcodes and deposited in an online database(http://virusbarcodedatabase.top/).The successful integration of barcoding technology in SARS-CoV-2 identification provides valuable insights for future studies involving complete genome sequence polymorphism analysis.Moreover,this cost-effective and efficient identification approach also provides valuable reference for future research endeavors related to virus surveillance.
基金This study was supported by the National Natural Science Foundation of China(No.51804310No.52074301)Fundamental Research Funds for the Central Universities(No.2020XJNY05).
文摘There is great variation in the lithology and lamination thickness of composite roof in coal-measure strata;thus,the roof is prone to delamination and falling,and it is difficult to control the surrounding rock when developing roadway in such rock strata.In deep mining,the stress environment of surrounding rock is complex,and the mechanical response of the rock mass is different from that of the shallow rock mass.For composite-roof roadway excavated in deep rock mass,the key to safe and efficient production of the mine is ensuring the stability of the roadway.The present paper obtains typical failure characteristics and deformation and failure mechanisms of composite-roof roadway with a buried depth of 650 m at Zhaozhuang Coal Mine(Shanxi Province,China).On the basis of determining a reasonable cross-section shape of the roadway and according to the failure characteristics of the composite roof in different regions,the roof is divided into an unstable layer,metastable layer,and stable layer.The controlled unstable layer and metastable layer are regarded as a small structure while the stable layer is regarded as a large structure.A superimposed coupling support technology of large and small structures with a multi-level prestressed bearing arch formed by strong rebar bolts and highly prestressed cable bolts is put forward.The support technology provides good application results in the field.The study thus provides theoretical support and technical guidance for ground control under similar geological conditions.
基金funding from the European Union’s Horizon 2020 research and innovation program under Marie Sklodowska-Curie(Grant No.:101007976)The authors also express their sincere grati-tude to the Engineering and Physical Sciences Research Council(EPSRC)for the funding provided to this project(Grant Nos.:EP/V041665/1 and EP/T022701/1)This work was also financially supported by the National Key Research and Development Program of China(Grant No.:2021YFE0112500).
文摘A dynamic modeling framework based on an intelligent approach is proposed to identify the complex behaviors of solid-gas sorption systems.An experimental system was built and tested to assist in developing a model of the system performance during the adsorption and desorption processes.The variations in the thermal effects and gaseous environment accompanying the reactions were considered when designing the model.An optimization platform based on a multi-population genetic algorithm and artificial criteria was established to identify the mod-eling coefficients and quantify the effects of condition changes on the reactions.The calibration of the simulation results against the tested data showed good accuracy,where the coefficient of determination was greater than 0.988.The outcome of this study could provide a modeling basis for the optimization of solid-gas sorption systems and contribute a potential tool for uncovering key characteristics associated with materials and components.
基金jointly supported by the Natural Science Foundation of China(Nos.51874199,22078200,22102103)the grant from SZIIT(No.SZIIT2022KJ026)+1 种基金Guangdong Basic and Applied Basic Research Foundation(Nos.2019A1515111021,2021A1515010162)Shenzhen Innovation Program(No.JCYJ20170818142642395)。
文摘The strong intrinsic Coulomb interactions of Frenkel excitons in crystalline carbon nitride(CCN) greatly limits their dissociation into electrons and holes, resulting in unsatisfactory charges separation and photocatalytic efficiency. Herein, we propose a strategy to facilitate excitons dissociation by molecular regulation induced built-in electric field(BIEF). The electron-rich pyrimidine-ring into CCN changes the charge density distribution over heptazine-rings to induce BIEF between melon chains. Such BIEF is sufficient to overcome the considerable exciton binding energy(EBE) and reduce it from 38.4 meV to 16.4 meV,increasing the excitons dissociation efficiency(EDE) from 21.5% to 51.9%. Our results establish a strategy to facilitate excitons dissociation through molecular regulation induced BIEF, targeting the intrinsic high EBE and low EDE of polymer photocatalysts.
基金the Shandong Provincial Natural Science Foundation(ZR2019YQ19,ZR2019BEM018)the National Natural Science Foundation of China(51403113,21404065,52072193)the Project of Shandong Province Higher Educational Science and Technology Program(2019KJA026)。
文摘The key to develop high specific energy rechargeable batteries is development of new electrode materials.The existing electrode materials still have many problems:the shuttle effect and poor conductivity of the sulfur cathode,the inevitable volume expansion of the silicon anode and the lithium dendrite of the lithium metal anode that cause short circuits,etc.Nanofibers,as active electrical materials,conductive additives and electrode bodies,can play multiple roles in electrode design.More interestingly,nanofibers can be functionalized to obtain better controllable properties(i.e.,electrolyte affinity,pore size distribution and surface electronic structure),thereby further enhancing electrochemical performance.In this article,the latest research progress in electrode design based on nanofibers is reviewed,including processing methods,structure,morphology and electrochemical performance.The key problems affecting the electrochemical performance of the electrode are also discussed,such as the preparation process,atomic structure,electrical conductivity,surface area and pore distribution of nanofibers,to provide reference points for nanofibers in excellent electrode design.
文摘Carbon capture is widely recognised as an essential strategy to meet global goals for climate protection.Although various C02 capture technologies including absorption,adsorption and membrane exist,they are not yet mature for post-combustion power plants mainly due to high energy penalty.Hence researchers are concentrating on developing non-aqueous solvents like ionic liquids,C 02-binding organic liquids,nanoparticle hybrid materials and microencapsulated sorbents to minimize the energy consumption for carbon capture.This research aims to develop a novel and efficient approach by encapsulating sorbents to capture C02 in a cold environment.The conventional emulsion technique was selected for the microcapsule formulation by using 2-amino-2-methyl-l-propanol(AMP)as the core sorbent and silicon dioxide as the shell.This paper reports the findings on the formulated microcapsules including key formulation parameters,microstructure,size distribution and thermal cycling stability.Furthermore,the effects of microcapsule quality and absorption temperature on the C02 loading capacity of the microcapsules were investigated using a self-developed pressure decay method.The preliminary results have shown that the AMP microcapsules are promising to replace conventional sorbents.
基金support from the National Natural Science Foundation of China (52025028,51772197,5187219152002258)+6 种基金the 1000 Youth Talents Planthe Shandong Provincial Natural Science Foundation (Nos.ZR2021JQ16,ZR2019YQ19)the Project of Shandong Province Higher Educational Science and Technology Program (No.2019KJA026)the State Key Laboratory of Bio-Fibers and Eco-Textiles (Nos.ZKT13,ZKT11)Science and technology project of Shinan District (No.2020-2-003-QT)the Natural Science Foundation of Jiangsu Province (Nos.BK20200877,BK20210728)Funded by the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions。
文摘Light regulation devices are essential for signal modulation, information encryption and energy-saving smart windows. Recently, due to their excellent stimuli-responsive properties, lead halide perovskites have shown great potential. However, the high transition temperature, irreversibility of the phase transition and toxicity of heavy metals make perovskite materials unsuitable for devices related to human activity. Herein, for the first time, a flexible perovskite nano-network is proposed and its application as a smart window is demonstrated. The perovskite-sodium alginate(SA) nano-network showed a 31.6 ℃(20% RH) transition temperature and stability over 1200 cycles. The hydrophobic surface and the “eggbox” structure formed by SA make that the lead leakage is only 2.569 ppb, which is much higher than the drinking water standard. This work provides a successful demonstration for energy-efcient buildings and inspires future nontoxic perovskite-based devices through heavy metal control.