In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asy...In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asymptotic stability of the trivial solution and the positive periodic solution.Finally,numerical simulations are presented to validate our results.Our results show that age-selective harvesting is more conducive to sustainable population survival than non-age-selective harvesting.展开更多
To explore the formation mechanism of anisotropy in Ti-6Al-4V alloy fabricated by selective laser melting(SLM),the compressive mechanical properties,microhardness,microstructure,and crystallographic orientation of the...To explore the formation mechanism of anisotropy in Ti-6Al-4V alloy fabricated by selective laser melting(SLM),the compressive mechanical properties,microhardness,microstructure,and crystallographic orientation of the alloy across different planes were investigated.The anisotropy of SLM-fabricated Ti-6Al-4V alloys was analyzed,and the electron backscatter diffraction technique was used to investigate the influence of different grain types and orientations on the stress-strain distribution at various scales.Results reveal that in room-temperature compression tests at a strain rate of 10^(-3) s^(-1),both the compressive yield strength and microhardness vary along the deposition direction,indicating a certain degree of mechanical property anisotropy.The alloy exhibits a columnar microstructure;along the deposition direction,the grains appear equiaxed,and they have internal hexagonal close-packed(hcp)α/α'martensitic structure.α'phase has a preferential orientation approximately along the<0001>direction.Anisotropy arises from the high aspect ratio of columnar grains,along with the weak texture of the microstructure and low symmetry of the hcp crystal structure.展开更多
Selective depression of pyrite remains a major bottleneck in copper flotation,particularly when high-pyrite ores are processed and saline water is used.In such environments,conventional approaches using lime and inert...Selective depression of pyrite remains a major bottleneck in copper flotation,particularly when high-pyrite ores are processed and saline water is used.In such environments,conventional approaches using lime and inert grinding media often fail to discriminate ef-fectively between pyrite and valuable copper minerals due to strong copper activation on pyrite surfaces.This study introduced a novel approach using inorganic radicals generated from peroxymonosulfate(PMS)to selectively oxidize and depress pyrite.Flotation tests with synthetic high-pyrite ore blends showed that PMS significantly reduced pyrite recovery while maintaining or improving chalcopyrite flot-ation.Ethylenediaminetetraacetic acid(EDTA)extraction confirmed selective oxidation of pyrite,and electron paramagnetic resonance(EPR)spectroscopy identified hydroxyl(·OH)and sulfate(SO_(4)^(·-))radicals as the dominant reactive species.Iron ions from grinding me-dia and mineral surfaces were identified as key activators of PMS.A major insight was pyrite’s dual role,acting both as a radical scav-enger and an activator,which made it highly reactive and susceptible to radical-induced oxidation.This process converted surface copper-sulfur species into copper hydroxides,effectively suppressing pyrite flotation.While previous studies have applied EPR to detect radicals in simplified activator/precursor systems,this study provides the first direct mechanistic evidence of radical-driven selectivity in flotation by detecting inorganic radicals in a complex flotation slurry,thereby demonstrating their persistence under industrially relevant conditions and establishing a foundation for more effective and targeted flotation strategies.展开更多
Selective laser melting(SLM),as an additive manufacturing technology,has garnered widespread attention for its capability to fabricate components with complex geometries and to tailor the microstructure and mechanical...Selective laser melting(SLM),as an additive manufacturing technology,has garnered widespread attention for its capability to fabricate components with complex geometries and to tailor the microstructure and mechanical properties under specific conditions.However,the intrinsic influence mechanism of microstructure formation under non-equilibrium solidification conditions in SLM processes has not been clearly revealed.In the present work,the influence of Al concentration and process parameters on the microstructure forming mechanism of Al_(x)CoCrFeNi HEAs prepared by SLM is investigated by molecular dynamics simulation method.The simulation results show that the difference in Al content significantly affects the microstructure formation of HEAs,including the growth rate and morphology of columnar crystals,stress distribution at grain boundaries,and defect structure.In addition,the results show that increasing the substrate temperature improves the solidification formability,reduces microstructural defects,and helps reduce residual stress in Al_(x)CoCrFeNi HEAs.By analyzing the influence of heat and solute flow in the molten pool on the growth of columnar crystals,it is found that spatial fluctuations in Al concentration during the non-equilibrium solidification process inhibit the high cooling rates induced by steep temperature gradients.These findings promote the understanding of the forming mechanism of microstructure in HEAs prepared by SLM and provide theoretical guidance for designing high-performance SLM-fabricated HEAs.展开更多
Developing biomass platform compounds into high value-added chemicals is a key step in renewable resource utilization.Herein,we report porous carbon-supported Ni-ZnO nanoparticles catalyst(Ni-ZnO/AC)synthesized via lo...Developing biomass platform compounds into high value-added chemicals is a key step in renewable resource utilization.Herein,we report porous carbon-supported Ni-ZnO nanoparticles catalyst(Ni-ZnO/AC)synthesized via low-temperature coprecipitation,exhibiting excellent performance for the selective hydrogenation of 5-hydroxymethylfurfural(HMF).A linear correlation is first observed between solvent polarity(E_(T)(30))and product selectivity within both polar aprotic and protic solvent classes,suggesting that solvent properties play a vital role in directing reaction pathways.Among these,1,4-dioxane(aprotic)favors the formation of 2,5-bis(hydroxymethyl)furan(BHMF)with 97.5%selectivity,while isopropanol(iPrOH,protic)promotes 2,5-dimethylfuran production with up to 99.5%selectivity.Mechanistic investigations further reveal that beyond polarity,proton-donating ability is critical in facilitating hydrodeoxygenation.iPrOH enables a hydrogen shuttle mechanism where protons assist in hydroxyl group removal,lowering the activation barrier.In contrast,1,4-dioxane,lacking hydrogen bond donors,stabilizes BHMF and hinders further conversion.Density functional theory calculations confirm a lower activation energy in iPrOH(0.60 eV)compared to 1,4-dioxane(1.07 eV).This work offers mechanistic insights and a practical strategy for solvent-mediated control of product selectivity in biomass hydrogenation,highlighting the decisive role of solvent-catalyst-substrate interactions.展开更多
Metal hydrides with high hydrogen density provide promising hydrogen storage paths for hydrogen transportation.However,the requirement of highly pure H_(2)for re-hydrogenation limits its wide application.Here,amorphou...Metal hydrides with high hydrogen density provide promising hydrogen storage paths for hydrogen transportation.However,the requirement of highly pure H_(2)for re-hydrogenation limits its wide application.Here,amorphous Al_(2)O_(3)shells(10 nm)were deposited on the surface of highly active hydrogen storage material particles(MgH_(2)-ZrTi)by atomic layer deposition to obtain MgH_(2)-ZrTi@Al_(2)O_(3),which have been demonstrated to be air stable with selective adsorption of H_(2)under a hydrogen atmosphere with different impurities(CH_(4),O_(2),N_(2),and CO_(2)).About 4.79 wt% H_(2)was adsorbed by MgH_(2)-ZrTi@10nmAl_(2)O_(3)at 75℃under 10%CH_(4)+90%H_(2)atmosphere within 3 h with no kinetic or density decay after 5 cycles(~100%capacity retention).Furthermore,about 4 wt%of H_(2)was absorbed by MgH_(2)-ZrTi@10nmAl_(2)O_(3)under 0.1%O_(2)+0.4%N_(2)+99.5%H_(2)and 0.1%CO_(2)+0.4%N_(2)+99.5%H_(2)atmospheres at 100℃within 0.5 h,respectively,demonstrating the selective hydrogen absorption of MgH_(2)-ZrTi@10nmAl_(2)O_(3)in both oxygen-containing and carbon dioxide-containing atmospheres hydrogen atmosphere.The absorption and desorption curves of MgH_(2)-ZrTi@10nmAl_(2)O_(3)with and without absorption in pure hydrogen and then in 21%O_(2)+79%N_(2)for 1 h were found to overlap,further confirming the successful shielding effect of Al_(2)O_(3)shells against O_(2)and N_(2).The MgH_(2)-ZrTi@10nmAl_(2)O_(3)has been demonstrated to be air stable and have excellent selective hydrogen absorption performance under the atmosphere with CH_(4),O_(2),N_(2),and CO_(2).展开更多
The recovery of gold from waste electronic and electric equipment(WEEE) has gained great attention with the increased number of WEEE,because it can largely alleviate the pressure on the environment and resources.Coval...The recovery of gold from waste electronic and electric equipment(WEEE) has gained great attention with the increased number of WEEE,because it can largely alleviate the pressure on the environment and resources.Covalent organic frameworks(COFs) are ideal adsorbents for gold recovery owing to their large surface area,good stability,easily functionalized ability,periodic structures,and definitive nanopores.Herein,a cyano-functionalized COF(COF-CN) with high crystallinity was large-scale prepared under mild conditions for the recovery of gold.The introduction of cyano groups enable COF-CN to exhibit excellent gold recovery performance,which possesses fast adsorption kinetics,high cycling stability,and adsorption capacity up to 663.67 mg/g.Excitingly,COF-CN showed extremely high selectivity for gold ions,even in the presence of various competing cations and anions.The COF-CN maintained excellent selectivity and removal efficiency in gold recovery experiments from WEEE.The facile synthesis of COF-CN and its outstanding selectivity in actual samples make it an attractive opportunity for practical gold recovery.展开更多
The potential of 2-amino-1-propanol(AP)as a novel depressant in selectively floating ilmenite from titanaugite under weakly acidic conditions was investigated.Micro-flotation results show that AP significantly reduces...The potential of 2-amino-1-propanol(AP)as a novel depressant in selectively floating ilmenite from titanaugite under weakly acidic conditions was investigated.Micro-flotation results show that AP significantly reduces the recovery of titanaugite while having no evident impact on ilmenite flotation.Subsequent bench-scale flotation tests further confirm a remarkable improvement in separation efficiency upon the introduction of AP.Contact angle and adsorption tests reveal a stronger affinity of AP towards the titanaugite surface in comparison to ilmenite.Zeta potential measurements and X-ray photoelectron spectroscopy(XPS)analyses exhibit favorable adsorption characteristics of AP on titanaugite,resulting from a synergy of electrostatic attraction and chemical interaction.In contrast,electrostatic repulsion hinders any significant interaction between AP and the ilmenite surface.These findings highlight the potential of AP as a highly efficient depressant for ilmenite flotation,paving the way for reduced reliance on sulfuric acid in the industry.展开更多
Radioactive microspheres have demonstrated excellent therapeutic effects and good tolerance in the treatment of unresectable primary and secondary liver malignancies.This is attributed to precise embolization and pote...Radioactive microspheres have demonstrated excellent therapeutic effects and good tolerance in the treatment of unresectable primary and secondary liver malignancies.This is attributed to precise embolization and potent anti-tumor effect.However,certain limitations such as unstable loading,perfusion stasis,heterogeneous distribution,ectopic distribution,and insufficient dosage,restrict their clinical application.Herein,a novel personalized Y-90 carbon microsphere with high uniformity,high specific activity and high availability(^(90)Y-HUACM)is presented.It is synthesized through planar molecular complex adsorption and chemical deposition solidification.^(90)Y-HUACM exhibited controllable size,excellent biocompatibility,outstanding in vitro and in vivo stability.The radiolabeling efficiency of Y-90 exceeded 99%and the leaching rate of Y-90 is far below 0.1%.Furthermore,the excellent anti-tumor effect,nuclide loading stability,anti-reflux characteristics,precise embolization,and biosafety of^(90)Y-HUACM were validated in a rabbit VX2liver tumor model.In summary,this new,high-performance,and customizable radioactive microsphere provides a superior choice for selective internal radiation treatment of advanced liver cancer is expected to be rapidly applied in clinical practice.展开更多
Selective laser melting(SLM)is a cost-effective 3 D metal additive manufacturing(AM)process.However,AM 316 L stainless steel(SS)has different surface and microstructure properties as compared to conventional ones.Bori...Selective laser melting(SLM)is a cost-effective 3 D metal additive manufacturing(AM)process.However,AM 316 L stainless steel(SS)has different surface and microstructure properties as compared to conventional ones.Boriding process is one of the ways to modify and increase the surface properties.The aim of this study is to predict and understand the growth kinetic of iron boride layers on AM 316 L SS.In this study,the growth kinetic mechanism was evaluated for AM 316 L SS.Pack boriding was applied at 850,900 and 950℃,each for 2,4 and 6 h.The thickness of the boride layers ranged from(1.8±0.3)μm to(27.7±2.2)μm.A diffusion model based on error function solutions in Fick’s second law was proposed to quantitatively predict and elucidate the growth rate of FeB and Fe_(2)B phase layers.The activation energy(Q)values for boron diffusion in FeB layer,Fe_(2)B layer,and dual FeB+Fe_(2)B layer were found to be 256.56,161.61 and 209.014 kJ/mol,respectively,which were higher than the conventional 316 L SS.The findings might provide and open new directions and approaches for applications of additively manufactured steels.展开更多
Austenitic stainless steel(ASS)is a common material used in high-pressure hydrogen systems.Prolonged exposure to high-pressure hydrogen can cause hydrogen embrittlement(HE),raising significant safety concerns.Selectiv...Austenitic stainless steel(ASS)is a common material used in high-pressure hydrogen systems.Prolonged exposure to high-pressure hydrogen can cause hydrogen embrittlement(HE),raising significant safety concerns.Selective Laser Melting(SLM),known for its high precision,is a promising additive manufacturing technology that has been widely adopted across various industries.Studies have reported that under certain SLM manufacturing conditions and process parameters,the HE resistance of SLM ASS is significantly better than that of conventionally manufactured(CM)ASS,showing great potential for application in high-pressure hydrogen systems.Thus,studying the HE of SLM ASS is crucial for further improving the safety of high-pressure hydrogen systems.This paper provides an overview of the SLM process,reviews the mechanisms of HE and their synergistic effects,and analyzes the HE characteristics of SLM ASS.Additionally,it examines the influence of unique microstructures and SLM process variables on HE of SLM ASS and offers recommendations for future research to enhance the safety of high-pressure hydrogen systems.展开更多
To clarify the densification behavior,deformation response and strengthening mechanisms of selective laser melted(SLM)Mg-RE alloys,this study systematically investigates a representative WE43 alloy via advanced materi...To clarify the densification behavior,deformation response and strengthening mechanisms of selective laser melted(SLM)Mg-RE alloys,this study systematically investigates a representative WE43 alloy via advanced material characterization techniques.A suitable laser output mode fell into the transition mode,allowing for the fabrication of nearly full-density samples(porosity=0.85±0.021%)with favorable mechanical properties(yield strength=351 MPa,ultimate tensile strength=417 MPa,the elongation at break=6.5%and microhardness=137.9±6.15 HV_(0.1))using optimal processing parameters(P=80 W,v=250 mm/s and d=50μm).Viscoplastic self-consistent analysis and transmission electron microscopy observations reveal that the plastic deformation response of the SLM Mg-RE alloys is primarily driven by basal and prismatic slips.Starting from a random texture before deformation(maximum multiple of ultimate density,Max.MUD=3.95),plastic stretching led the grains to align with the Z-axis,finally resulting in a{0001}<1010>texture orientation after fracture(Max.MUD=8.755).Main phases of the SLM state are mainly composed ofα-Mg,Mg_(24)Y_(5) andβ'-Mg_(41)Nd_(5),with an average grain size of only 4.27μm(about a quarter of that in the extruded state),resulting in a favorable strength-toughness ratio.Except for the nano-β'phase and semi-coherent Mg_(24)Y_(5) phase(mismatch=16.12%)around the grain boundaries,a small amount of nano-ZrO_(2) and Y_(2)O_(3) particles also play a role in dispersion strengthening.The high mechanical properties of the SLM state are chiefly attributed to precipitation hardening(44.41%),solid solution strengthening(34.06%)and grain boundary strengthening(21.53%),with precipitation hardening being predominantly driven by dislocation strengthening(67.77%).High-performance SLM Mg-RE alloy components were manufactured and showcased at TCT Asia 2024,receiving favorable attention.This work underscores the significant application potential of SLM Mg-RE alloys and establishes a strong foundation for advancing their use in the biomedical fields.展开更多
Increasing evidence showed that histone deacetylase 6(HDAC6)dysfunction is directly associated with the onset and progression of various diseases,especially cancers,making the development of HDAC6-targeted anti-tumor ...Increasing evidence showed that histone deacetylase 6(HDAC6)dysfunction is directly associated with the onset and progression of various diseases,especially cancers,making the development of HDAC6-targeted anti-tumor agents a research hotspot.In this study,artificial intelligence(AI)technology and molecular simulation strategies were fully integrated to construct an efficient and precise drug screening pipeline,which combined Voting strategy based on compound-protein interaction(CPI)prediction models,cascade molecular docking,and molecular dynamic(MD)simulations.The biological potential of the screened compounds was further evaluated through enzymatic and cellular activity assays.Among the identified compounds,Cmpd.18 exhibited more potent HDAC6 enzyme inhibitory activity(IC_(50)=5.41 nM)than that of tubastatin A(TubA)(IC_(50)=15.11 nM),along with a favorable subtype selectivity profile(selectivity index z 117.23 for HDAC1),which was further verified by the Western blot analysis.Additionally,Cmpd.18 induced G2/M phase arrest and promoted apoptosis in HCT-116 cells,exerting desirable antiproliferative activity(IC_(50)=2.59 mM).Furthermore,based on long-term MD simulation trajectory,the key residues facilitating Cmpd.18's binding were identified by decomposition free energy analysis,thereby elucidating its binding mechanism.Moreover,the representative conformation analysis also indicated that Cmpd.18 could stably bind to the active pocket in an effective conformation,thus demonstrating the potential for in-depth research of the 2-(2-phenoxyethyl)pyridazin-3(2H)-one scaffold.展开更多
Intracellular bacteria(ICB),cloaked by the protective barriers of host cells,pose a formidable challenge to selective and efficient eradication.The employment of activatable photosensitizers based antibacterial photod...Intracellular bacteria(ICB),cloaked by the protective barriers of host cells,pose a formidable challenge to selective and efficient eradication.The employment of activatable photosensitizers based antibacterial photodynamic therapy(a PDT)holds significant potential for selective imaging and photo-inactivation of ICB while minimizing side effects on normal cells.Drawing inspiration from the elevated hypochlorous acid(HClO)levels in ICB infected phagocytes,herein we firstly designed and synthesized a series of HCl Oresponsive dinuclear Ru(Ⅱ)complexes(Ru1-Ru3)to achieve such a goal.Initially,the luminescence,^(1)O_(2)generation and a PDT activity of these Ru(Ⅱ)complexes were suppressed due to the quenching effect of the azo group,but were recovered after reaction with HCl O in solutions or within ICB infected phagocytes.The detailed results revealed that Ru1 and Ru3 could not only selectively visualize ICB,but also demonstrated remarkable a PDT activity against ICB,surpassing vancomycin both in vitro and in vivo.展开更多
Defect engineering in metal organic frameworks(MOFs)has captured significant attention in the field of photocatalysis.A series of UiO-66(Ce)(UiO=University of Oslo)MOFs with different contents of missing-linker defect...Defect engineering in metal organic frameworks(MOFs)has captured significant attention in the field of photocatalysis.A series of UiO-66(Ce)(UiO=University of Oslo)MOFs with different contents of missing-linker defects have been developed for the photocatalytic selective oxidation of benzylamine(BA)and thioanisole(TA)under visible light.The introduction of missing-linker defects promotes the formation of unsaturated Ce sites with a high Ce3+content.It also generates a high concentration of oxygen vacancies.In situ Fourier transform infrared spectroscopy(FTIR)results revealed that BA and TA molecules were activated on coordinatively unsaturated Ce sites via the H-N…Ce and the C-S…Ce interactions,respectively.Simulated in situ electron paramagnetic resonance(EPR)data indicate that O_(2) activation and reduction occur at coordinatively unsaturated Ce^(3+)sites to form·O_(2)^(-).This is accelerated by the Ce^(3+)/Ce^(4+)redox cycle associated with the photogenerated electrons.The corresponding photogenerated holes are involved in the deprotonation of the activated BA and TA.The most active sample exhibits 98.4%and 95.5%conversion rates for BA and TA oxidation.Mechanisms for the molecular activation are proposed at the molecular level.展开更多
Base-catalyzed nucleophilic substitution reactions ofβ-ketonitrile with azodicarboxylates have been developed.A series of disubstituted C—N coupling products were obtained in good to excellent yields under Et_(3)N c...Base-catalyzed nucleophilic substitution reactions ofβ-ketonitrile with azodicarboxylates have been developed.A series of disubstituted C—N coupling products were obtained in good to excellent yields under Et_(3)N catalysis.Monosubstitu-tion C—N bond formation reaction catalyzed by K_(2)CO_(3) also gave novel enol-based target products.This method is simple and mild,with good chemoselectivity,excellent substrate compatibility and tolerance for various functional groups,and achieves gram-scale synthesis.The reaction is a nucleophilic substitution process without the involvement of free radicals.展开更多
The selective hydrogenation ofα,β-unsaturated aldehydes/ketones enables precise control over product structures and properties by regulating hydrogen transport pathways and bond cleavage sequences to selectively red...The selective hydrogenation ofα,β-unsaturated aldehydes/ketones enables precise control over product structures and properties by regulating hydrogen transport pathways and bond cleavage sequences to selectively reduce C=C or C=O bonds while preserving other functional groups within the molecule.This approach serves as a critical strategy for the directional synthesis of high-value molecules.However,achieving such selectivity remains challenging due to the thermodynamic equilibrium and kinetic competition between C=O and C=C bonds inα,β-unsaturated systems.Consequently,constructing precisely targeted catalytic systems is essential to overcome these limitations,offering both fundamental scientific significance and industrial application potential.Metal-organic frameworks(MOFs)and their derivatives have emerged as innovative platforms for designing such systems,owing to their programmable topology,tunable pore microenvironments,spatially controllable active sites,and modifiable electronic structures.This review systematically summarizes the research progress of MOF-based catalysts for selec-tive hydrogenation ofα,β-unsaturated aldehydes/ketones in the last decade,with emphasis on the design strategy,conformational relationship,and catalytic mechanism,aiming to provide new ideas for the design of targeted catalyt-ic systems for the selective hydrogenation ofα,β-unsaturated aldehydes/ketones.展开更多
ZGH401 alloy was prepared under varying laser power levels and scanning speeds by the orthogonal test method using selective laser melting(SLM).The effect of different energy densities on microstructure and mechanical...ZGH401 alloy was prepared under varying laser power levels and scanning speeds by the orthogonal test method using selective laser melting(SLM).The effect of different energy densities on microstructure and mechanical properties of the formed alloy was investigated.The microstructure of ZGH401 was analyzed by scanning electron microscope,electron back-scattered diffraction,and electron probe microanalysis.The results show that the defects of the as-built ZGH401 are gradually reduced,the relative density is correspondingly enhanced with increasing the energy density,and the ultimate density can reach 99.6%.An increase in laser power leads to a corresponding rise in hardness of ZGH401,while a faster scanning speed reduces the residual stress in asbuilt ZGH401 samples.In addition,better tensile properties are achieved at room temperature due to more grain boundaries perpendicular to the build direction than parallel to the build direction.The precipitated phases are identified as carbides and Laves phases via chemical composition analysis,with fewer carbides observed at the molten pool boundaries than within the molten pools.展开更多
We report a robust pillar-layered metal-organic framework,Zn‑tfbdc‑dabco(tfbdc:tetrafluoroterephthal-ate,dabco:1,4-diazabicyclo[2.2.2]octane),featuring the fluorinated pore environment,for the preferential binding of ...We report a robust pillar-layered metal-organic framework,Zn‑tfbdc‑dabco(tfbdc:tetrafluoroterephthal-ate,dabco:1,4-diazabicyclo[2.2.2]octane),featuring the fluorinated pore environment,for the preferential binding of propane over propylene and thus highly inverse selective separation of propane/propylene mixture.The inverse propane-selective performance of Zn‑tfbdc‑dabco for the propane/propylene separation was validated by single-component gas adsorption isotherms,isosteric enthalpy of adsorption calculations,ideal adsorbed solution theory calculations,along with the breakthrough experiment.The customized fluorinated networks served as a propane-trap to form more interactions with the exposed hydrogen atoms of propane,as unveiled by the simulation studies at the molecular level.With the advantage of inverse propane-selective adsorption behavior,high adsorption capacity,good cycling stability,and low isosteric enthalpy of adsorption,Zn‑tfbdc‑dabco can be a promising candidate adsorbent for the challenging propane/propylene separation to realize one-step purification of the target propylene substance.展开更多
Developing selective electrodes for lithium extraction from brines remains challenging.This work reports room-temperature synthesized cubic copper hexacyanoferrate(Cu HCF)nanoparticles for hybrid capacitive deionizati...Developing selective electrodes for lithium extraction from brines remains challenging.This work reports room-temperature synthesized cubic copper hexacyanoferrate(Cu HCF)nanoparticles for hybrid capacitive deionization(HCDI).The Cu HCF framework exhibits a high surface area(715.84 m^(2)·g^(-1)),dual redoxactive sites([Fe^(Ⅲ)(CN)_(6)]^(4-)/[Fe^(Ⅱ)(CN)_(6)]^(3-)and Cu^(+)/Cu^(2+)),and excellent cyclability(99.4%capacity retention after 1000 cycles).In HCDI system,the Cu HCF cathode demonstrates remarkable Li^(+)ions selectivity,achieving a 25.5 mg·g^(-1)adsorption capacity in 500 mg·L^(-1)Li Cl solution with 94%charge efficiency at1.2 V.Notably,in mixed Li^(+)/Mg^(2+)solutions(30:1 molar ratio),Cu HCF nanoparticles maintain a high separation coefficient of 3.1,attributed to the synergistic effects of ionic sieving and preferential redox interactions.Mechanistic studies confirm Li^(+)(de)intercalation via reversible[Fe^(Ⅲ)(CN)_(6)]^(4-)/[Fe^(Ⅱ)(CN)_(6)]^(3-)and Cu^(2+)/Cu^(+)transitions.Density functional theory calculations reveal Li^(+)exhibits lower adsorption energy than Mg^(2+)(-3.72 e V vs.-1.49 e V),which fundamentally explains the preferential extraction capability of Li^(+)ions over Mg^(2+)ions during the separation process.This study advances ion-selective pseudocapacitor design for sustainable lithium extraction from high-salinity resources.展开更多
基金Supported by the National Natural Science Foundation of China(12261018)Universities Key Laboratory of Mathematical Modeling and Data Mining in Guizhou Province(2023013)。
文摘In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asymptotic stability of the trivial solution and the positive periodic solution.Finally,numerical simulations are presented to validate our results.Our results show that age-selective harvesting is more conducive to sustainable population survival than non-age-selective harvesting.
基金National Natural Science Foundation of China(51504138,51674118,52271177)Hunan Provincial Natural Science Foundation of China(2023JJ50181)Supported by State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology(P2024-022)。
文摘To explore the formation mechanism of anisotropy in Ti-6Al-4V alloy fabricated by selective laser melting(SLM),the compressive mechanical properties,microhardness,microstructure,and crystallographic orientation of the alloy across different planes were investigated.The anisotropy of SLM-fabricated Ti-6Al-4V alloys was analyzed,and the electron backscatter diffraction technique was used to investigate the influence of different grain types and orientations on the stress-strain distribution at various scales.Results reveal that in room-temperature compression tests at a strain rate of 10^(-3) s^(-1),both the compressive yield strength and microhardness vary along the deposition direction,indicating a certain degree of mechanical property anisotropy.The alloy exhibits a columnar microstructure;along the deposition direction,the grains appear equiaxed,and they have internal hexagonal close-packed(hcp)α/α'martensitic structure.α'phase has a preferential orientation approximately along the<0001>direction.Anisotropy arises from the high aspect ratio of columnar grains,along with the weak texture of the microstructure and low symmetry of the hcp crystal structure.
基金support from the Australian Research Council(ARC)Linkage Project(No.LP230100166).
文摘Selective depression of pyrite remains a major bottleneck in copper flotation,particularly when high-pyrite ores are processed and saline water is used.In such environments,conventional approaches using lime and inert grinding media often fail to discriminate ef-fectively between pyrite and valuable copper minerals due to strong copper activation on pyrite surfaces.This study introduced a novel approach using inorganic radicals generated from peroxymonosulfate(PMS)to selectively oxidize and depress pyrite.Flotation tests with synthetic high-pyrite ore blends showed that PMS significantly reduced pyrite recovery while maintaining or improving chalcopyrite flot-ation.Ethylenediaminetetraacetic acid(EDTA)extraction confirmed selective oxidation of pyrite,and electron paramagnetic resonance(EPR)spectroscopy identified hydroxyl(·OH)and sulfate(SO_(4)^(·-))radicals as the dominant reactive species.Iron ions from grinding me-dia and mineral surfaces were identified as key activators of PMS.A major insight was pyrite’s dual role,acting both as a radical scav-enger and an activator,which made it highly reactive and susceptible to radical-induced oxidation.This process converted surface copper-sulfur species into copper hydroxides,effectively suppressing pyrite flotation.While previous studies have applied EPR to detect radicals in simplified activator/precursor systems,this study provides the first direct mechanistic evidence of radical-driven selectivity in flotation by detecting inorganic radicals in a complex flotation slurry,thereby demonstrating their persistence under industrially relevant conditions and establishing a foundation for more effective and targeted flotation strategies.
基金supported by the National Natural Science Foundation of China(Grant No.12102133).
文摘Selective laser melting(SLM),as an additive manufacturing technology,has garnered widespread attention for its capability to fabricate components with complex geometries and to tailor the microstructure and mechanical properties under specific conditions.However,the intrinsic influence mechanism of microstructure formation under non-equilibrium solidification conditions in SLM processes has not been clearly revealed.In the present work,the influence of Al concentration and process parameters on the microstructure forming mechanism of Al_(x)CoCrFeNi HEAs prepared by SLM is investigated by molecular dynamics simulation method.The simulation results show that the difference in Al content significantly affects the microstructure formation of HEAs,including the growth rate and morphology of columnar crystals,stress distribution at grain boundaries,and defect structure.In addition,the results show that increasing the substrate temperature improves the solidification formability,reduces microstructural defects,and helps reduce residual stress in Al_(x)CoCrFeNi HEAs.By analyzing the influence of heat and solute flow in the molten pool on the growth of columnar crystals,it is found that spatial fluctuations in Al concentration during the non-equilibrium solidification process inhibit the high cooling rates induced by steep temperature gradients.These findings promote the understanding of the forming mechanism of microstructure in HEAs prepared by SLM and provide theoretical guidance for designing high-performance SLM-fabricated HEAs.
基金the National Nature Science Foundation of China for Excellent Young Scientists Fund(32222058)Fundamental Research Foundation of CAF(CAFYBB2022QB001).
文摘Developing biomass platform compounds into high value-added chemicals is a key step in renewable resource utilization.Herein,we report porous carbon-supported Ni-ZnO nanoparticles catalyst(Ni-ZnO/AC)synthesized via low-temperature coprecipitation,exhibiting excellent performance for the selective hydrogenation of 5-hydroxymethylfurfural(HMF).A linear correlation is first observed between solvent polarity(E_(T)(30))and product selectivity within both polar aprotic and protic solvent classes,suggesting that solvent properties play a vital role in directing reaction pathways.Among these,1,4-dioxane(aprotic)favors the formation of 2,5-bis(hydroxymethyl)furan(BHMF)with 97.5%selectivity,while isopropanol(iPrOH,protic)promotes 2,5-dimethylfuran production with up to 99.5%selectivity.Mechanistic investigations further reveal that beyond polarity,proton-donating ability is critical in facilitating hydrodeoxygenation.iPrOH enables a hydrogen shuttle mechanism where protons assist in hydroxyl group removal,lowering the activation barrier.In contrast,1,4-dioxane,lacking hydrogen bond donors,stabilizes BHMF and hinders further conversion.Density functional theory calculations confirm a lower activation energy in iPrOH(0.60 eV)compared to 1,4-dioxane(1.07 eV).This work offers mechanistic insights and a practical strategy for solvent-mediated control of product selectivity in biomass hydrogenation,highlighting the decisive role of solvent-catalyst-substrate interactions.
基金supported by the National Natural Science Foundation of China(22175136)the State Key Laboratory of Electrical Insulation and Power Equipment(EIPE23127)the Fundamental Research Funds for the Central Universities(xtr052024009).
文摘Metal hydrides with high hydrogen density provide promising hydrogen storage paths for hydrogen transportation.However,the requirement of highly pure H_(2)for re-hydrogenation limits its wide application.Here,amorphous Al_(2)O_(3)shells(10 nm)were deposited on the surface of highly active hydrogen storage material particles(MgH_(2)-ZrTi)by atomic layer deposition to obtain MgH_(2)-ZrTi@Al_(2)O_(3),which have been demonstrated to be air stable with selective adsorption of H_(2)under a hydrogen atmosphere with different impurities(CH_(4),O_(2),N_(2),and CO_(2)).About 4.79 wt% H_(2)was adsorbed by MgH_(2)-ZrTi@10nmAl_(2)O_(3)at 75℃under 10%CH_(4)+90%H_(2)atmosphere within 3 h with no kinetic or density decay after 5 cycles(~100%capacity retention).Furthermore,about 4 wt%of H_(2)was absorbed by MgH_(2)-ZrTi@10nmAl_(2)O_(3)under 0.1%O_(2)+0.4%N_(2)+99.5%H_(2)and 0.1%CO_(2)+0.4%N_(2)+99.5%H_(2)atmospheres at 100℃within 0.5 h,respectively,demonstrating the selective hydrogen absorption of MgH_(2)-ZrTi@10nmAl_(2)O_(3)in both oxygen-containing and carbon dioxide-containing atmospheres hydrogen atmosphere.The absorption and desorption curves of MgH_(2)-ZrTi@10nmAl_(2)O_(3)with and without absorption in pure hydrogen and then in 21%O_(2)+79%N_(2)for 1 h were found to overlap,further confirming the successful shielding effect of Al_(2)O_(3)shells against O_(2)and N_(2).The MgH_(2)-ZrTi@10nmAl_(2)O_(3)has been demonstrated to be air stable and have excellent selective hydrogen absorption performance under the atmosphere with CH_(4),O_(2),N_(2),and CO_(2).
基金financially supported by the National Natural Science Foundation of China (No.51972302)。
文摘The recovery of gold from waste electronic and electric equipment(WEEE) has gained great attention with the increased number of WEEE,because it can largely alleviate the pressure on the environment and resources.Covalent organic frameworks(COFs) are ideal adsorbents for gold recovery owing to their large surface area,good stability,easily functionalized ability,periodic structures,and definitive nanopores.Herein,a cyano-functionalized COF(COF-CN) with high crystallinity was large-scale prepared under mild conditions for the recovery of gold.The introduction of cyano groups enable COF-CN to exhibit excellent gold recovery performance,which possesses fast adsorption kinetics,high cycling stability,and adsorption capacity up to 663.67 mg/g.Excitingly,COF-CN showed extremely high selectivity for gold ions,even in the presence of various competing cations and anions.The COF-CN maintained excellent selectivity and removal efficiency in gold recovery experiments from WEEE.The facile synthesis of COF-CN and its outstanding selectivity in actual samples make it an attractive opportunity for practical gold recovery.
基金supported by the National Key Research and Development Program of China(No.2019YFC1803501)the National Natural Science Foundation of China(No.52074357)+2 种基金the Natural Science Foundation of Hunan Province,China(No.2022JJ30713)the Vanadium Titanium Union Foundationthe Project of Technology Innovation Center for Comprehensive Utilization of Strategic Mineral Resources,Ministry of Natural Resources,China。
文摘The potential of 2-amino-1-propanol(AP)as a novel depressant in selectively floating ilmenite from titanaugite under weakly acidic conditions was investigated.Micro-flotation results show that AP significantly reduces the recovery of titanaugite while having no evident impact on ilmenite flotation.Subsequent bench-scale flotation tests further confirm a remarkable improvement in separation efficiency upon the introduction of AP.Contact angle and adsorption tests reveal a stronger affinity of AP towards the titanaugite surface in comparison to ilmenite.Zeta potential measurements and X-ray photoelectron spectroscopy(XPS)analyses exhibit favorable adsorption characteristics of AP on titanaugite,resulting from a synergy of electrostatic attraction and chemical interaction.In contrast,electrostatic repulsion hinders any significant interaction between AP and the ilmenite surface.These findings highlight the potential of AP as a highly efficient depressant for ilmenite flotation,paving the way for reduced reliance on sulfuric acid in the industry.
基金supported by the National Major Scientific and Technological Special Project for“Significant New Drugs Development”(No.2018ZX09201018–028)the nuclear energy development projects of China during the 13thFive Year Plan periodthe key research and development project of the Sichuan Provincial Department of Science and Technology(No.18ZDYF1466)。
文摘Radioactive microspheres have demonstrated excellent therapeutic effects and good tolerance in the treatment of unresectable primary and secondary liver malignancies.This is attributed to precise embolization and potent anti-tumor effect.However,certain limitations such as unstable loading,perfusion stasis,heterogeneous distribution,ectopic distribution,and insufficient dosage,restrict their clinical application.Herein,a novel personalized Y-90 carbon microsphere with high uniformity,high specific activity and high availability(^(90)Y-HUACM)is presented.It is synthesized through planar molecular complex adsorption and chemical deposition solidification.^(90)Y-HUACM exhibited controllable size,excellent biocompatibility,outstanding in vitro and in vivo stability.The radiolabeling efficiency of Y-90 exceeded 99%and the leaching rate of Y-90 is far below 0.1%.Furthermore,the excellent anti-tumor effect,nuclide loading stability,anti-reflux characteristics,precise embolization,and biosafety of^(90)Y-HUACM were validated in a rabbit VX2liver tumor model.In summary,this new,high-performance,and customizable radioactive microsphere provides a superior choice for selective internal radiation treatment of advanced liver cancer is expected to be rapidly applied in clinical practice.
文摘Selective laser melting(SLM)is a cost-effective 3 D metal additive manufacturing(AM)process.However,AM 316 L stainless steel(SS)has different surface and microstructure properties as compared to conventional ones.Boriding process is one of the ways to modify and increase the surface properties.The aim of this study is to predict and understand the growth kinetic of iron boride layers on AM 316 L SS.In this study,the growth kinetic mechanism was evaluated for AM 316 L SS.Pack boriding was applied at 850,900 and 950℃,each for 2,4 and 6 h.The thickness of the boride layers ranged from(1.8±0.3)μm to(27.7±2.2)μm.A diffusion model based on error function solutions in Fick’s second law was proposed to quantitatively predict and elucidate the growth rate of FeB and Fe_(2)B phase layers.The activation energy(Q)values for boron diffusion in FeB layer,Fe_(2)B layer,and dual FeB+Fe_(2)B layer were found to be 256.56,161.61 and 209.014 kJ/mol,respectively,which were higher than the conventional 316 L SS.The findings might provide and open new directions and approaches for applications of additively manufactured steels.
基金finncially supported by the National Natural Science Foundation of China(No.52075183)the Guangdong Basic and Applied Research Fundamental(No.2023A1515010692)the Key-Area Research and Development Program of Guangdong Province(Nos.2024B1111080002 and 2020B0404020004).
文摘Austenitic stainless steel(ASS)is a common material used in high-pressure hydrogen systems.Prolonged exposure to high-pressure hydrogen can cause hydrogen embrittlement(HE),raising significant safety concerns.Selective Laser Melting(SLM),known for its high precision,is a promising additive manufacturing technology that has been widely adopted across various industries.Studies have reported that under certain SLM manufacturing conditions and process parameters,the HE resistance of SLM ASS is significantly better than that of conventionally manufactured(CM)ASS,showing great potential for application in high-pressure hydrogen systems.Thus,studying the HE of SLM ASS is crucial for further improving the safety of high-pressure hydrogen systems.This paper provides an overview of the SLM process,reviews the mechanisms of HE and their synergistic effects,and analyzes the HE characteristics of SLM ASS.Additionally,it examines the influence of unique microstructures and SLM process variables on HE of SLM ASS and offers recommendations for future research to enhance the safety of high-pressure hydrogen systems.
基金supported by the National Key Research and Development Program of China(No.2022YFC2406000)the Guangdong Basic and Applied Basic Research Foundation(2024A1515011024)+5 种基金the Guangzhou Science and Technology Project(2024A04J4943)the Guangdong Academy of Sciences Development Special Fund Project(2022GDASZH-2022010107)the Guangdong province Science and Technology Plan Projects(2023B1212120008,2023B1212060045)the GDAS Projects of International cooperation platform of Science and Technology(2022GDASZH-2022010203-003)Special Support Foundation of Guangdong Province(2023TQ07Z559)Shenzhen Basic Research Project(JCYJ20210324120001003 and JCYJ20220531091802006)。
文摘To clarify the densification behavior,deformation response and strengthening mechanisms of selective laser melted(SLM)Mg-RE alloys,this study systematically investigates a representative WE43 alloy via advanced material characterization techniques.A suitable laser output mode fell into the transition mode,allowing for the fabrication of nearly full-density samples(porosity=0.85±0.021%)with favorable mechanical properties(yield strength=351 MPa,ultimate tensile strength=417 MPa,the elongation at break=6.5%and microhardness=137.9±6.15 HV_(0.1))using optimal processing parameters(P=80 W,v=250 mm/s and d=50μm).Viscoplastic self-consistent analysis and transmission electron microscopy observations reveal that the plastic deformation response of the SLM Mg-RE alloys is primarily driven by basal and prismatic slips.Starting from a random texture before deformation(maximum multiple of ultimate density,Max.MUD=3.95),plastic stretching led the grains to align with the Z-axis,finally resulting in a{0001}<1010>texture orientation after fracture(Max.MUD=8.755).Main phases of the SLM state are mainly composed ofα-Mg,Mg_(24)Y_(5) andβ'-Mg_(41)Nd_(5),with an average grain size of only 4.27μm(about a quarter of that in the extruded state),resulting in a favorable strength-toughness ratio.Except for the nano-β'phase and semi-coherent Mg_(24)Y_(5) phase(mismatch=16.12%)around the grain boundaries,a small amount of nano-ZrO_(2) and Y_(2)O_(3) particles also play a role in dispersion strengthening.The high mechanical properties of the SLM state are chiefly attributed to precipitation hardening(44.41%),solid solution strengthening(34.06%)and grain boundary strengthening(21.53%),with precipitation hardening being predominantly driven by dislocation strengthening(67.77%).High-performance SLM Mg-RE alloy components were manufactured and showcased at TCT Asia 2024,receiving favorable attention.This work underscores the significant application potential of SLM Mg-RE alloys and establishes a strong foundation for advancing their use in the biomedical fields.
基金funded by Central Guidance on Local Science and Technology Development Fund of Hebei Province,China(Grant No.:226Z2605G)the Key Project from Hebei Provincial Department of Science and Technology,China(Grant No.:21372601D)+6 种基金Graduate Student Innovation Grant Program of Hebei Medical University,China(Grant No.:XCXZZB202303)Science Research Project of Hebei Education Department,China(Grant Nos.:BJ2025046,and CYZD202501)Program for Young Scientists in the Field of Natural Science of Hebei Medical University,China(Program Nos.:CYCZ2023010,CYCZ2023011,CYQD2021011,CYQD2021015 and CYQD2023012)Traditional Chinese Medicine Administration Project of Hebei Province,China(Project No.:2025427)National Natural Science Foundation of China(Grant No.:32100771)the Hebei Provincial Medical Science Research Project Plan,China(Project Nos.:20240241 and 20220200)Shijiazhuang Science and Technology Bureau,China(Grant Nos.:241200487A,and 07202204).
文摘Increasing evidence showed that histone deacetylase 6(HDAC6)dysfunction is directly associated with the onset and progression of various diseases,especially cancers,making the development of HDAC6-targeted anti-tumor agents a research hotspot.In this study,artificial intelligence(AI)technology and molecular simulation strategies were fully integrated to construct an efficient and precise drug screening pipeline,which combined Voting strategy based on compound-protein interaction(CPI)prediction models,cascade molecular docking,and molecular dynamic(MD)simulations.The biological potential of the screened compounds was further evaluated through enzymatic and cellular activity assays.Among the identified compounds,Cmpd.18 exhibited more potent HDAC6 enzyme inhibitory activity(IC_(50)=5.41 nM)than that of tubastatin A(TubA)(IC_(50)=15.11 nM),along with a favorable subtype selectivity profile(selectivity index z 117.23 for HDAC1),which was further verified by the Western blot analysis.Additionally,Cmpd.18 induced G2/M phase arrest and promoted apoptosis in HCT-116 cells,exerting desirable antiproliferative activity(IC_(50)=2.59 mM).Furthermore,based on long-term MD simulation trajectory,the key residues facilitating Cmpd.18's binding were identified by decomposition free energy analysis,thereby elucidating its binding mechanism.Moreover,the representative conformation analysis also indicated that Cmpd.18 could stably bind to the active pocket in an effective conformation,thus demonstrating the potential for in-depth research of the 2-(2-phenoxyethyl)pyridazin-3(2H)-one scaffold.
基金supported by National Natural Science Foundation of China(No.22371289)。
文摘Intracellular bacteria(ICB),cloaked by the protective barriers of host cells,pose a formidable challenge to selective and efficient eradication.The employment of activatable photosensitizers based antibacterial photodynamic therapy(a PDT)holds significant potential for selective imaging and photo-inactivation of ICB while minimizing side effects on normal cells.Drawing inspiration from the elevated hypochlorous acid(HClO)levels in ICB infected phagocytes,herein we firstly designed and synthesized a series of HCl Oresponsive dinuclear Ru(Ⅱ)complexes(Ru1-Ru3)to achieve such a goal.Initially,the luminescence,^(1)O_(2)generation and a PDT activity of these Ru(Ⅱ)complexes were suppressed due to the quenching effect of the azo group,but were recovered after reaction with HCl O in solutions or within ICB infected phagocytes.The detailed results revealed that Ru1 and Ru3 could not only selectively visualize ICB,but also demonstrated remarkable a PDT activity against ICB,surpassing vancomycin both in vitro and in vivo.
基金supported by the National Natural Science Foundation of China(Nos.22272026 and 22272028)the 111 Project(No.D16008)Jinhong Bi thanks the Youth Talent Support Program of Fujian Province(No.00387077).
文摘Defect engineering in metal organic frameworks(MOFs)has captured significant attention in the field of photocatalysis.A series of UiO-66(Ce)(UiO=University of Oslo)MOFs with different contents of missing-linker defects have been developed for the photocatalytic selective oxidation of benzylamine(BA)and thioanisole(TA)under visible light.The introduction of missing-linker defects promotes the formation of unsaturated Ce sites with a high Ce3+content.It also generates a high concentration of oxygen vacancies.In situ Fourier transform infrared spectroscopy(FTIR)results revealed that BA and TA molecules were activated on coordinatively unsaturated Ce sites via the H-N…Ce and the C-S…Ce interactions,respectively.Simulated in situ electron paramagnetic resonance(EPR)data indicate that O_(2) activation and reduction occur at coordinatively unsaturated Ce^(3+)sites to form·O_(2)^(-).This is accelerated by the Ce^(3+)/Ce^(4+)redox cycle associated with the photogenerated electrons.The corresponding photogenerated holes are involved in the deprotonation of the activated BA and TA.The most active sample exhibits 98.4%and 95.5%conversion rates for BA and TA oxidation.Mechanisms for the molecular activation are proposed at the molecular level.
文摘Base-catalyzed nucleophilic substitution reactions ofβ-ketonitrile with azodicarboxylates have been developed.A series of disubstituted C—N coupling products were obtained in good to excellent yields under Et_(3)N catalysis.Monosubstitu-tion C—N bond formation reaction catalyzed by K_(2)CO_(3) also gave novel enol-based target products.This method is simple and mild,with good chemoselectivity,excellent substrate compatibility and tolerance for various functional groups,and achieves gram-scale synthesis.The reaction is a nucleophilic substitution process without the involvement of free radicals.
文摘The selective hydrogenation ofα,β-unsaturated aldehydes/ketones enables precise control over product structures and properties by regulating hydrogen transport pathways and bond cleavage sequences to selectively reduce C=C or C=O bonds while preserving other functional groups within the molecule.This approach serves as a critical strategy for the directional synthesis of high-value molecules.However,achieving such selectivity remains challenging due to the thermodynamic equilibrium and kinetic competition between C=O and C=C bonds inα,β-unsaturated systems.Consequently,constructing precisely targeted catalytic systems is essential to overcome these limitations,offering both fundamental scientific significance and industrial application potential.Metal-organic frameworks(MOFs)and their derivatives have emerged as innovative platforms for designing such systems,owing to their programmable topology,tunable pore microenvironments,spatially controllable active sites,and modifiable electronic structures.This review systematically summarizes the research progress of MOF-based catalysts for selec-tive hydrogenation ofα,β-unsaturated aldehydes/ketones in the last decade,with emphasis on the design strategy,conformational relationship,and catalytic mechanism,aiming to provide new ideas for the design of targeted catalyt-ic systems for the selective hydrogenation ofα,β-unsaturated aldehydes/ketones.
基金National Defense Science and Technology Project Management Center(2021-JCJQ-JJ-0092)。
文摘ZGH401 alloy was prepared under varying laser power levels and scanning speeds by the orthogonal test method using selective laser melting(SLM).The effect of different energy densities on microstructure and mechanical properties of the formed alloy was investigated.The microstructure of ZGH401 was analyzed by scanning electron microscope,electron back-scattered diffraction,and electron probe microanalysis.The results show that the defects of the as-built ZGH401 are gradually reduced,the relative density is correspondingly enhanced with increasing the energy density,and the ultimate density can reach 99.6%.An increase in laser power leads to a corresponding rise in hardness of ZGH401,while a faster scanning speed reduces the residual stress in asbuilt ZGH401 samples.In addition,better tensile properties are achieved at room temperature due to more grain boundaries perpendicular to the build direction than parallel to the build direction.The precipitated phases are identified as carbides and Laves phases via chemical composition analysis,with fewer carbides observed at the molten pool boundaries than within the molten pools.
文摘We report a robust pillar-layered metal-organic framework,Zn‑tfbdc‑dabco(tfbdc:tetrafluoroterephthal-ate,dabco:1,4-diazabicyclo[2.2.2]octane),featuring the fluorinated pore environment,for the preferential binding of propane over propylene and thus highly inverse selective separation of propane/propylene mixture.The inverse propane-selective performance of Zn‑tfbdc‑dabco for the propane/propylene separation was validated by single-component gas adsorption isotherms,isosteric enthalpy of adsorption calculations,ideal adsorbed solution theory calculations,along with the breakthrough experiment.The customized fluorinated networks served as a propane-trap to form more interactions with the exposed hydrogen atoms of propane,as unveiled by the simulation studies at the molecular level.With the advantage of inverse propane-selective adsorption behavior,high adsorption capacity,good cycling stability,and low isosteric enthalpy of adsorption,Zn‑tfbdc‑dabco can be a promising candidate adsorbent for the challenging propane/propylene separation to realize one-step purification of the target propylene substance.
基金supported by the National Natural Science Foundation of China(52202093)Postgraduate research&practice innovation program of Jiangsu province(SJCX25_2553)+1 种基金the China Postdoctoral Science Foundation(2023M731357)the open project of Anhui Province Key Laboratory of Efficient Conversion and Solid-State Storage of Hydrogen&Electricity(ECSSHE2024KF03)。
文摘Developing selective electrodes for lithium extraction from brines remains challenging.This work reports room-temperature synthesized cubic copper hexacyanoferrate(Cu HCF)nanoparticles for hybrid capacitive deionization(HCDI).The Cu HCF framework exhibits a high surface area(715.84 m^(2)·g^(-1)),dual redoxactive sites([Fe^(Ⅲ)(CN)_(6)]^(4-)/[Fe^(Ⅱ)(CN)_(6)]^(3-)and Cu^(+)/Cu^(2+)),and excellent cyclability(99.4%capacity retention after 1000 cycles).In HCDI system,the Cu HCF cathode demonstrates remarkable Li^(+)ions selectivity,achieving a 25.5 mg·g^(-1)adsorption capacity in 500 mg·L^(-1)Li Cl solution with 94%charge efficiency at1.2 V.Notably,in mixed Li^(+)/Mg^(2+)solutions(30:1 molar ratio),Cu HCF nanoparticles maintain a high separation coefficient of 3.1,attributed to the synergistic effects of ionic sieving and preferential redox interactions.Mechanistic studies confirm Li^(+)(de)intercalation via reversible[Fe^(Ⅲ)(CN)_(6)]^(4-)/[Fe^(Ⅱ)(CN)_(6)]^(3-)and Cu^(2+)/Cu^(+)transitions.Density functional theory calculations reveal Li^(+)exhibits lower adsorption energy than Mg^(2+)(-3.72 e V vs.-1.49 e V),which fundamentally explains the preferential extraction capability of Li^(+)ions over Mg^(2+)ions during the separation process.This study advances ion-selective pseudocapacitor design for sustainable lithium extraction from high-salinity resources.
