The retrospective study by Edwar et al reinforces the role of therapeutic penetrating keratoplasty(PK)as a vital intervention in severe,treatment-resistant infectious keratitis.In advanced cases—often complicated by ...The retrospective study by Edwar et al reinforces the role of therapeutic penetrating keratoplasty(PK)as a vital intervention in severe,treatment-resistant infectious keratitis.In advanced cases—often complicated by trauma,delayed presentation,and corneal perforation—PK restores globe integrity and provides limited visual recovery.However,its application is constrained by graft-related complications and donor shortages,particularly in low-resource settings.These limitations highlight the need for earlier,globe-sparing strategies to prevent progression and reduce surgical demand.Photoactivated chromophore for infectious keratitis-corneal collagen cross-linking(PACK-CXL)has emerged as a promising adjunct or alternative.With both antimicrobial and tissue-stabilizing effects,PACK-CXL may control infection and preserve corneal structure in earlier stages.A layered treatment framework that incorporates PACK-CXL as an initial intervention and reserves PK for refractory cases may help improve clinical outcomes.Further studies are needed to define their best use in practice.展开更多
Based on the characteristics of laser-induced surface ignition,energetic photosensitive films show promising potential to meet the ignition requirements of various energetic materials(EMs).In this study,DATNBI/ferric ...Based on the characteristics of laser-induced surface ignition,energetic photosensitive films show promising potential to meet the ignition requirements of various energetic materials(EMs).In this study,DATNBI/ferric alginate(DI/FeA),DI/cobalt alginate(DI/CoA),and DI/nickel alginate(DI/Ni A)films are fabricated by employing sodium alginate(SA)with a three-dimensional network structure as the film matrix,via ionic cross-linking of SA with Fe^(3+),Co^(2+),and Ni^(2+)ions.The study demonstrates that the ionic cross-linking enhances the hydrophobic performance of the films,with the water contact angle increasing from 82.1° to 123.5°.Concurrently,the films'near-infrared(NIR)light absorption improved.Furthermore,transition metal ions facilitate accelerated electron transfer,thereby catalyzing the thermal decomposition of DATNBI.Under 1064 nm laser irradiation,the DI/Fe A film exhibits exceptional combustion performance,with an ignition delay time as low as 76 ms.It successfully acts as an NIR laser ignition medium to initiate the self-sustained combustion of CL-20.This study demonstrates the synergistic realization of enhanced hydrophobicity,improved photosensitivity,and promoted catalytic decomposition through microstructural design of the material,providing new insights for the design of additive-free EMs in laser ignition applications.展开更多
Corn starch(CS)is a renewable,biodegradable polysaccharide valued for its film-forming ability,yet native CS films exhibit lowmechanical strength,highwater sensitivity,and limited thermal stability.This study improves...Corn starch(CS)is a renewable,biodegradable polysaccharide valued for its film-forming ability,yet native CS films exhibit lowmechanical strength,highwater sensitivity,and limited thermal stability.This study improves CS-based films by blending with poly(vinyl alcohol)(PVA)or glycerol(GLY)and using citric acid(CA)as a green,non-toxic cross-linker.Composite films were prepared by casting CS–PVA or CS-GLY with CA at 0%-0.20%(w/w of starch).The influence of CA on physicochemical,mechanical,optical,thermal,and water barrier properties was evaluated.CA crosslinking markedly enhanced the tensile strength,water resistance,and thermal stability of CS-PVA films while increasing transparency in CS–GLY films.At 0.20%CA,the composite achieved 34.99MPa tensile strength,reducedwater vapor permeability,andminimized water uptake.FTIR confirmed ester bond formation between CAand hydroxyl groups of CS,PVA,and GLY,whereas thermal analysis showed higher decomposition temperatures and lower weight loss in crosslinked films.Increasing CA levels also decreased opacity and improved light transmittance,indicating greater homogeneity and reduced crystallinity.This dual-polymer matrix combined with a natural crosslinking strategy provides a sustainable route to high-performance,biodegradable CS-based packaging materials.展开更多
一、作为哲学的AI for Process(一)郭为的哲学思想1.郭为是谁郭为是谁?他是一位哲学家。顺便说,他同时还领导着神州数码。为什么说郭为是哲学家呢?因为他在著作中谈到高深的哲学,如“数据如水,奔流不息,无界融合”。他引述古希腊哲学家...一、作为哲学的AI for Process(一)郭为的哲学思想1.郭为是谁郭为是谁?他是一位哲学家。顺便说,他同时还领导着神州数码。为什么说郭为是哲学家呢?因为他在著作中谈到高深的哲学,如“数据如水,奔流不息,无界融合”。他引述古希腊哲学家赫拉克利特所说的“万物流转”,又说“你不能两次踏进同一条河流,因为新的水不断地流过你的身旁”,他所表达的意思是“世界上唯一不变的就是变化”。展开更多
A simple and effective photochemical method was developed for cross-linking of polymer gate dielectrics. Laborious synthetic processes for functionalizing polymer dielectrics with photo-cross-linkable groups were avoi...A simple and effective photochemical method was developed for cross-linking of polymer gate dielectrics. Laborious synthetic processes for functionalizing polymer dielectrics with photo-cross-linkable groups were avoided. The photo-cross-linker, BBP-4, was added into host polymers by simple solution blending process, which was capable of abstracting hydrogen atoms from polymers containing active C--H groups upon exposure to ultraviolet （UV） radiation. The cross-linking can be completed with a relatively long wavelength UV light （365 nm）. The approach has been applied to methacrylate and styrenic polymers such as commercial poly（methylmethacrylate） （PMMA）, poly（iso-butylmethacrylate） （PiBMA） and poly（4-methylstyrene） （PMS）. The cross-linked networks enhanced dielectric properties and solvent resistance of the thin films. The bottom-gate organic field-effect transistors （OFETs） through all solution processes on plastic substrate were fabricated. The OFET devices showed low voltage operation and steep subthreshold swing at relatively small gate dielectric capacitance.展开更多
LiMnxFe1-xPO_(4) is a promising cathode candidate due to its high security and the availability of a high 4.1 V operating voltage and high energy density.However,the poor electrochemical kinetics and structural instab...LiMnxFe1-xPO_(4) is a promising cathode candidate due to its high security and the availability of a high 4.1 V operating voltage and high energy density.However,the poor electrochemical kinetics and structural instability currently hinder its broader application.Herein,inspired by the hydrogen-bonded cross-linking and steric hindrance effect between short-chain polymer molecules(polyethylene glycol-400,PEG-400),the pomegranate-type LiMn_(0.5)Fe_(0.5)PO_(4)-0.5@C(P-LMFP@C)cathode materials with 3D ion/electron dual-conductive network structure were constructed through ball mill-assisted spray-drying method.The intermolecular effects of PEG-400 promote the spheroidization and uniform PEG coating of LMFP precursor,which prevents agglomeration during sintering.The 3D ion/electron dual-conductive network structure in P-LMFP@C accelerates the Li^(+)transport kinetics,improving the rate performance and cycling stability.As a result,the designed P-LMFP@C has remarkable electrochemical behavior,boasting excellent capacity retention(98%after 100 cycles at the 1C rate)and rate capability(91 mAh·g^(-1)at 20C).Such strategy introduces a novel window for designing high-performance olivine cathodes and offers compatibility with a range of energy storage materials for diverse applications.展开更多
AIM:To compare simultaneous corneal collagen cross-linking(CXL)with intracorneal ring segment(ICRS)implantation versus successive ICRS followed by CXL and detect the impact of the timing of CXL after ICRS implantation...AIM:To compare simultaneous corneal collagen cross-linking(CXL)with intracorneal ring segment(ICRS)implantation versus successive ICRS followed by CXL and detect the impact of the timing of CXL after ICRS implantation in the successive method.METHODS:This is a retrospective study of the records of three groups of patients.Group 1 of 28 patients were operated on with simultaneous ICRS implantation and CXL,group 2 of 32 patients had ICRS implantation followed by CXL after 1mo,and group 3 of 38 patients had ICRS implantation followed by CXL after 3mo.The three groups had follow-up visits after 6,12,and 24mo.RESULTS:The preoperative data,age,and gender differences among 3 groups revealed no significant differences.The postoperative spherical equivalent and best-corrected visual acuity were improved significantly in all groups compared to the baseline,which were more evident in groups 1 and 2.The differences between preoperative and postoperative mean values of mean of K readings(Km)and maximum K reading(Kmax)at 6mo were 4.66 and 4.1 D in group 1,4.43 and 4.64 D in group 2,but 3.2 and 3.4 D in group 3,respectively.The spherical aberrations and the vertical coma showed significant postoperative changes in all groups,and trefoil showed nonsignificant changes.CONCLUSION:Simultaneous and sequential ICRS implantation and CXL at 1mo has similar Km and Kmax better postoperative changes than when both surgeries were done at three-month intervals.展开更多
AIM:To investigate the response of the anterior and posterior corneal surface in femtosecond laser-assisted convex stromal lenticule addition keratoplasty(SLAK)combined with cross-linking(CXL)for treating keratoconus ...AIM:To investigate the response of the anterior and posterior corneal surface in femtosecond laser-assisted convex stromal lenticule addition keratoplasty(SLAK)combined with cross-linking(CXL)for treating keratoconus at the first 3mo of follow-up.METHODS:In this prospective observational study,20 eyes of 20 keratoconus patients who underwent SLAK combined with CXL were included.The morphological indices in keratometry and elevation data were recorded from the Sirius at baseline and 1 and 3mo postoperatively.The mean values of maximum keratometry(K_(max)),flat keratometry(K_(1)),and steep keratometry(K_(2))at the central,3-mm,5-mm,and 7-mm areas were measured from the curvature map.The changes in anterior and posterior corneal elevation under the best-fit sphere(BFS)radius at seven points horizontally of the center,3-mm,5-mm,and 7-mm area from the center at both nasal(N)and temporal(T)side were measured from elevation map.RESULTS:For the front corneal curvature,K_(1),and K_(2) at 3-mm,5-mm,and 7-mm of the anterior corneal surface increased significantly 1mo postoperatively(all P<0.05)and remained unchanged until 3mo(P>0.05).For the back corneal curvature,K_(1) and K_(2) along the 3-mm back meridian significantly decreased after month 1(P=0.002,0.077,respectively).Posterior K_(2)-readings along the 5-mm and 7-mm did not change after surgery(P>0.05).Anterior BFS decreased 1mo(P<0.001)postoperatively but remained unchanged until 3mo after SLAK(P>0.05).There was no change in posterior BFS before and after the surgery(P>0.05).Anterior elevation at N5,N3,central,and T5 points and posterior elevation at central and T7 points shifted backward 1mo postoperatively(all P<0.05)and remained stable until 3mo(P>0.05).CONCLUSION:The myopic SLAK combined with CXL is an economical alternative for stabilizing the corneal surface in severe keraoconus.“Pseudoprogression”occurs in the early phase postoperatively,but it is not an indicator of keratoconus progression.展开更多
Aging is a persistent topic of interest,with skin aging as its most visible manifestation,characterized by a reduction in intact collagen and elastic fibers in the dermis.Hyaluronic acid,a vital component of the extra...Aging is a persistent topic of interest,with skin aging as its most visible manifestation,characterized by a reduction in intact collagen and elastic fibers in the dermis.Hyaluronic acid,a vital component of the extracellular matrix present in the skin,has become a mainstream method for skin rejuvenation through injections.However,the rapid degradation of pure hyaluronic acid,combined with insufficient maintenance duration and often limited therapeutic effects,presents significant challenges for injectable treatments.Additionally,low patient compliance due to discomfort from needles penetrating the dermal layer further complicates its use.In this review,we summarize and compare existing interventions for skin aging,focusing on strategies to prolong the degradation cycle of hyaluronic acid,including variations in cross-linking modalities and injection techniques.We conclude that the injection of cross-linked modified hyaluronic acid via microneedles represents a promising approach to extend the degradation cycle,offering valuable insights for current therapeutic strategies.展开更多
Polymer binders possess significant potential in alleviating the volume expansion issues of silicon-based anodes,yet remain challenging due to insufficient interfacial interactions with individual components(Si,C,and ...Polymer binders possess significant potential in alleviating the volume expansion issues of silicon-based anodes,yet remain challenging due to insufficient interfacial interactions with individual components(Si,C,and Cu)of the anode.Herein,we report the synthesis of a stable three-dimensional network structure of the PAA-PEA(polyacrylic acid-polyether amines)polymer binder through intermolecular physicochemical dual cross-linking.By incorporating polar functional groups,the binder molecules not only form strong C-O-Si,N-Si,O=C-O-C,and O=C-O-Cu covalent bonds but also enhance non-covalent interactions with Si,C,and Cu,thereby improving adhesion between the binder and each interface of the anode.Furthermore,weak hydrogen bonds,acting as"sacrificial bonds",dissipate energy and disperse accumulated stress,improving the material flexibility.Due to the high mechanical stability of the framework,which combines both rigidity and flexibility and the coupling effect at the three interfaces,the movement and separation of electrode components are effectively restrained,significantly enhancing the cycling stability of silicon-graphite anodes.The PAA-PEA 2000 electrode exhibits a capacity retention of 78% after 500 cycles at a current density of 0.2 A g^(-1).This work provides insights into the mechanism of binders and guides the design of polymer binders for high-performance Si-based electrodes.展开更多
In this study,a novel cost-effective methodology was developed to enhance the gas barrier properties and permselectivity of unfilled natural rubber(NR)/polybutadiene rubber(BR)composites through the construction of a ...In this study,a novel cost-effective methodology was developed to enhance the gas barrier properties and permselectivity of unfilled natural rubber(NR)/polybutadiene rubber(BR)composites through the construction of a heterogeneous structure using pre-vulcanized powder rubber to replace traditional fillers.The matrix material is composed of a blend of NR and BR,which is widely used in tire manufacturing.By incorporating pre-vulcanized trans-1,4-poly(isoprene-co-butadiene)(TBIR)rubber powder(pVTPR)with different cross-linking densities and contents,significant improvements in the gas barrier properties and CO_(2)permselectivity of the NR/BR/pVTPR composites were observed.The results indicated that compared to NR/BR/TBIR composites prepared through direct blending of NR,BR,and TBIR,the NR/BR/pVTPR composites exhibited markedly superior gas barrier properties.Increasing the cross-linking density of pVTPR resulted in progressive enhancement of the gas barrier properties of the NR/BR/pVTPR composite.For example,the addition of 20 phr pVTPR with a cross-linking density of 346 mol/m^(3)resulted in a 79%improvement in the oxygen barrier property of NR/BR/pVTPR compared to NR/BR,achieving a value of 5.47×10^(-14)cm^(3)·cm·cm^(-2)·s^(-1)·Pa^(-1).Similarly,the nitrogen barrier property improved by 76%compared to NR/BR,reaching 2.4×10^(-14)cm^(3)·cm·cm^(-2)·s^(-1)·Pa^(-1),which is 28%higher than the conventional inner liner material brominated butyl rubber(BIIR,PN2=3.32×10^(-14)cm^(3)·cm·cm^(-2)·s^(-1)·Pa^(-1)).Owing to its low cost,exceptional gas barrier properties,superior adhesion to various tire components,and co-vulcanization capabilities,the NR/BR/pVTPR composite has emerged as a promising alternative to butyl rubber in the inner liner of tires.Furthermore,by fine-tuning the cross-linking density of pVTPR,the high-gas-barrier NR/BR/pVTPR composites also demonstrated remarkable CO_(2)permselectivity,with a CO_(2)/N2 selectivity of 61.4 and a CO_(2)/O_(2)selectivity of 26.12.This innovation provides a novel strategy for CO_(2)capture and separation,with potential applications in future environmental and industrial processes.The multifunctional NR/BR/pVTPR composite,with its superior gas barrier properties and CO_(2)permselectivity,is expected to contribute to the development of safer,greener,and more cost-effective transportation solutions.展开更多
Selective hydrogenation of furfural to furfuryl alcohol is a great challenge in the hydrogenation field due to thermodynamic preference for hydrogenation of C=C over C=O.Herein,a novel Al_(2)O_(3)/C-u hybrid catalyst,...Selective hydrogenation of furfural to furfuryl alcohol is a great challenge in the hydrogenation field due to thermodynamic preference for hydrogenation of C=C over C=O.Herein,a novel Al_(2)O_(3)/C-u hybrid catalyst,composed of N-modified dendritic carbon networks supporting Al_(2)O_(3)nanoparticles,was successfully prepared via carbonizing the freeze-dried gel from spontaneous cross-linking of alginate,Al3+and urea.The obtained carbon-supported Al_(2)O_(3)hybrid catalyst has a high ratio (31%) of Al species in pentahedral-coordinated state.The introduction of urea enhances the surface N content,the ratio of pyrrolic N,and specific surface area of catalyst,leading to improved adsorption capacity of C=O and the accessibility of active sites.In the furfural hydrogenation reaction with isopropyl alcohol as hydrogen donor,Al_(2)O_(3)/C-u catalyst achieved a 90%conversion of furfural with 98.0% selectivity to furfuryl alcohol,outperforming that of commercial γ-Al_(2)O_(3).Moreover,Al_(2)O_(3)/C-u demonstrates excellent catalytic stability in the recycling tests attributed to the synergistic effect of abundant weak Lewis acid sites and the anchoring effect of the carbon network on Al_(2)O_(3)nanoparticles.This work provides an innovative and facile strategy for fabrication of carbon-supported Al_(2)O_(3)hybrid catalysts with rich AlVspecies,serving as a high selective hydrogenation catalyst through MPV reaction route.展开更多
A controlled cross-linking polymerization containing intra- and intermolecular reactions was designed based on random coil morphology of macromolecules in solution. The soluble intramolecular cross-linked maeromolecu...A controlled cross-linking polymerization containing intra- and intermolecular reactions was designed based on random coil morphology of macromolecules in solution. The soluble intramolecular cross-linked maeromolecule （ICM） was successfully synthesized in the system with PVA and MDI. We found an especial dissolving phenomenon, namely the semi-soluble phenomenon when some gels dissolved in DMF. The chain growth process of ICMs was investigated by Transmission electron microscopy （TEM） pictures of samples at different reacting times, in addition, TEM pictures show ICMs have three kinds of styles in structure, viz. ＂globule structure＂, ＂nubby structure＂ and the intervenient between the above two structures, and the efflux time of the ICMs was measured by an Ubbelohde viscosimeter, it was found that the efflux time decreases with the degree ofcrosslink increasing.展开更多
Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim ...Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of significant,novel,and high-impact research in the fields of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.展开更多
The in-flight heating process of cerium dioxide(CeO_(2))powders was investigated through experiments and numerical simulations.In the experiment,CeO_(2)powder(average size of 30μm)was injected into radio-frequency(RF...The in-flight heating process of cerium dioxide(CeO_(2))powders was investigated through experiments and numerical simulations.In the experiment,CeO_(2)powder(average size of 30μm)was injected into radio-frequency(RF)argon plasma,and the temperatures were measured using a DPV-2000 monitor.A model combining the electromagnetism,thermal flow,and heat transfer characteristics of powder during in-flight heating in argon plasma was proposed.The melting processes of CeO_(2)powders of different diameters,with and without thermal resistance effect,were investigated.Results show that the heating process of CeO_(2)powder particles consists of three main stages,one of which is relevant to a dimensionless parameter known as the Biot number.When the Biot value≥0.1,thermal resistance increases significantly,especially for the larger powders.The predicted temperature of the particles at the outlet(1800–2880 K)is in good agreement with the experimental result.展开更多
We successfully incorporated phenyl groups into a small-molecule quaternary ammonium cross-linker and synthesized cross-linked polybenzimidazole membranes via a one-step cross-linking process.Compared with conventiona...We successfully incorporated phenyl groups into a small-molecule quaternary ammonium cross-linker and synthesized cross-linked polybenzimidazole membranes via a one-step cross-linking process.Compared with conventional quaternary ammonium-crosslinked benzimidazole membranes,the introduction of phenyl groups significantly increases the free volume within the membrane.After phosphoric acid doping,the benzimidazole membrane with larger free volume retains more phosphoric acid compared to conventional quaternary ammonium-crosslinked membranes,forming an extensive hydrogen-bonding network that effectively enhances its anhydrous proton conductivity.The anhydrous proton conductivity reaches 91 mS·cm^(-1)at 160℃,substantially higher than that of conventional quaternary ammonium-crosslinked membranes with the same mass fraction.Benefiting from the improved conductivity,the membrane electrode assembly exhibits reduced ohmic polarization,achieving a peak power density of 792 mW·cm^(-2)at 160℃.展开更多
The hot compression deformation behavior of Mg-6Zn-1Mn-0.5Ca(ZM61-0.5Ca)and Mg-6Zn-1Mn-2Sn-0.5Ca(ZMT612-0.5Ca)alloys was investigated at deformation temperatures ranging from 250℃to 400℃and strain rates varying from...The hot compression deformation behavior of Mg-6Zn-1Mn-0.5Ca(ZM61-0.5Ca)and Mg-6Zn-1Mn-2Sn-0.5Ca(ZMT612-0.5Ca)alloys was investigated at deformation temperatures ranging from 250℃to 400℃and strain rates varying from 0.001 s^(-1) to 1 s^(-1).The results show that the addition of Sn promotes dynamic recrystallization(DRX),and CaMgSn phases can act as nucleation sites during the compression deformation.Flow stress increases with increasing the strain rate and decreasing the temperature.Both the ZM61-0.5Ca and ZMT612-0.5Ca alloys exhibit obvious DRX characteristics.CaMgSn phases can effectively inhibit dislocation motion with the addition of Sn,thus increasing the peak fl ow stress of the alloy.The addition of Sn increases the hot deformation activation energy of the ZM61-0.5Ca alloy from 199.654 kJ/mol to 276.649 kJ/mol,thus improving the thermal stability of the alloy.For the ZMT612-0.5Ca alloy,the optimal hot deformation parameters are determined to be a deformation temperature range of 350–400℃and a strain rate range of 0.001–0.01 s^(-1).展开更多
Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim ...Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of signifi cant,novel,and high-impact research in the fi elds of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.展开更多
Refractory metals,including tungsten(W),tantalum(Ta),molybdenum(Mo),and niobium(Nb),play a vital role in industries,such as nuclear energy and aerospace,owing to their exceptional melting temperatures,thermal durabili...Refractory metals,including tungsten(W),tantalum(Ta),molybdenum(Mo),and niobium(Nb),play a vital role in industries,such as nuclear energy and aerospace,owing to their exceptional melting temperatures,thermal durability,and corrosion resistance.These metals have body-centered cubic crystal structure,characterized by limited slip systems and impeded dislocation motion,resulting in significant low-temperature brittleness,which poses challenges for the conventional processing.Additive manufacturing technique provides an innovative approach,enabling the production of intricate parts without molds,which significantly improves the efficiency of material usage.This review provides a comprehensive overview of the advancements in additive manufacturing techniques for the production of refractory metals,such as W,Ta,Mo,and Nb,particularly the laser powder bed fusion.In this review,the influence mechanisms of key process parameters(laser power,scan strategy,and powder characteristics)on the evolution of material microstructure,the formation of metallurgical defects,and mechanical properties were discussed.Generally,optimizing powder characteristics,such as sphericity,implementing substrate preheating,and formulating alloying strategies can significantly improve the densification and crack resistance of manufactured parts.Meanwhile,strictly controlling the oxygen impurity content and optimizing the energy density input are also the key factors to achieve the simultaneous improvement in strength and ductility of refractory metals.Although additive manufacturing technique provides an innovative solution for processing refractory metals,critical issues,such as residual stress control,microstructure and performance anisotropy,and process stability,still need to be addressed.This review not only provides a theoretical basis for the additive manufacturing of high-performance refractory metals,but also proposes forward-looking directions for their industrial application.展开更多
The development of polymer nanoparticle composites with enhanced thermal and antibacterial properties is essential for next-generation biomedical materials.However,conventional polymers often exhibit limited bioactivi...The development of polymer nanoparticle composites with enhanced thermal and antibacterial properties is essential for next-generation biomedical materials.However,conventional polymers often exhibit limited bioactivity and poor resistance to degradation,restricting their functional applications.The novelty of this study involves the combination of the bio-derived cross-linker 2,5-bis(aminomethyl)furan(BAF)into poly(methylmethacrylate)PMMA to form a cross-linked network incorporated with various ratios of ZnO nanoparticles(ZnO NPs),resulting in improved biological and thermal properties.The surface morphologies,material crystallinity,and thermal degradation properties of the synthesized BAF-PMMA/ZnO were investigated using Scanning Electron microscopy(SEM),Energy-Dispersive X-ray spectroscopy(EDX),X-ray diffraction(XRD),andThermogravimetric characterization technique(TGA),respectively.The prepared BAF-PMMA/ZnO nanocomposites showed an enhancement in the crystallinity after increasing the ratio of ZnO NPs compared to the amorphous cross-linked BAF-PMMA polymer.The thermal stability of nanocomposites was significantly enhanced after the introduction of ZnO NPs into crosslinked BAF-PMMA polymer.The resultant nanocomposites BAF-PMMA/ZnO were examined as antibacterial agents against the Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)bacterial strains.The results showed that most BAF-PMMA/ZnO nanocomposites have antibacterial activity against both bacterial species compared to the pure cross-linked BAF-PMMA polymer.The BAF-PMMA/ZnO 10 wt.%sample shows the highest inhibition zone of(16.3±0.33)against E.coli.These outcomes demonstrate that such nanocomposites offer a viable pathway towardmultipurpose biomaterials with exceptional structural and biological features.展开更多
文摘The retrospective study by Edwar et al reinforces the role of therapeutic penetrating keratoplasty(PK)as a vital intervention in severe,treatment-resistant infectious keratitis.In advanced cases—often complicated by trauma,delayed presentation,and corneal perforation—PK restores globe integrity and provides limited visual recovery.However,its application is constrained by graft-related complications and donor shortages,particularly in low-resource settings.These limitations highlight the need for earlier,globe-sparing strategies to prevent progression and reduce surgical demand.Photoactivated chromophore for infectious keratitis-corneal collagen cross-linking(PACK-CXL)has emerged as a promising adjunct or alternative.With both antimicrobial and tissue-stabilizing effects,PACK-CXL may control infection and preserve corneal structure in earlier stages.A layered treatment framework that incorporates PACK-CXL as an initial intervention and reserves PK for refractory cases may help improve clinical outcomes.Further studies are needed to define their best use in practice.
基金supported by Research Fund of SWUST for PhD(Grant No.22zx7175)Sichuan Science and Technology Program(Grant No.2024NSFSC1097)。
文摘Based on the characteristics of laser-induced surface ignition,energetic photosensitive films show promising potential to meet the ignition requirements of various energetic materials(EMs).In this study,DATNBI/ferric alginate(DI/FeA),DI/cobalt alginate(DI/CoA),and DI/nickel alginate(DI/Ni A)films are fabricated by employing sodium alginate(SA)with a three-dimensional network structure as the film matrix,via ionic cross-linking of SA with Fe^(3+),Co^(2+),and Ni^(2+)ions.The study demonstrates that the ionic cross-linking enhances the hydrophobic performance of the films,with the water contact angle increasing from 82.1° to 123.5°.Concurrently,the films'near-infrared(NIR)light absorption improved.Furthermore,transition metal ions facilitate accelerated electron transfer,thereby catalyzing the thermal decomposition of DATNBI.Under 1064 nm laser irradiation,the DI/Fe A film exhibits exceptional combustion performance,with an ignition delay time as low as 76 ms.It successfully acts as an NIR laser ignition medium to initiate the self-sustained combustion of CL-20.This study demonstrates the synergistic realization of enhanced hydrophobicity,improved photosensitivity,and promoted catalytic decomposition through microstructural design of the material,providing new insights for the design of additive-free EMs in laser ignition applications.
基金supported through RIIM Competition funding from the Indonesia Endowment Fund for Education Agency,Ministry of Finance of the Republic of Indonesia and National Research and Innovation Agency of Indonesia according to the contract number:61/IV/KS/5/2023 and 2131/UN6.3.1/PT.00/2023.
文摘Corn starch(CS)is a renewable,biodegradable polysaccharide valued for its film-forming ability,yet native CS films exhibit lowmechanical strength,highwater sensitivity,and limited thermal stability.This study improves CS-based films by blending with poly(vinyl alcohol)(PVA)or glycerol(GLY)and using citric acid(CA)as a green,non-toxic cross-linker.Composite films were prepared by casting CS–PVA or CS-GLY with CA at 0%-0.20%(w/w of starch).The influence of CA on physicochemical,mechanical,optical,thermal,and water barrier properties was evaluated.CA crosslinking markedly enhanced the tensile strength,water resistance,and thermal stability of CS-PVA films while increasing transparency in CS–GLY films.At 0.20%CA,the composite achieved 34.99MPa tensile strength,reducedwater vapor permeability,andminimized water uptake.FTIR confirmed ester bond formation between CAand hydroxyl groups of CS,PVA,and GLY,whereas thermal analysis showed higher decomposition temperatures and lower weight loss in crosslinked films.Increasing CA levels also decreased opacity and improved light transmittance,indicating greater homogeneity and reduced crystallinity.This dual-polymer matrix combined with a natural crosslinking strategy provides a sustainable route to high-performance,biodegradable CS-based packaging materials.
文摘一、作为哲学的AI for Process(一)郭为的哲学思想1.郭为是谁郭为是谁?他是一位哲学家。顺便说,他同时还领导着神州数码。为什么说郭为是哲学家呢?因为他在著作中谈到高深的哲学,如“数据如水,奔流不息,无界融合”。他引述古希腊哲学家赫拉克利特所说的“万物流转”,又说“你不能两次踏进同一条河流,因为新的水不断地流过你的身旁”,他所表达的意思是“世界上唯一不变的就是变化”。
基金financially supported by the National Natural Science Foundation of China (Nos.21674060,21274087,61674102,and 61334008)National Key R&D Program (No.2016YFB0401100)
文摘A simple and effective photochemical method was developed for cross-linking of polymer gate dielectrics. Laborious synthetic processes for functionalizing polymer dielectrics with photo-cross-linkable groups were avoided. The photo-cross-linker, BBP-4, was added into host polymers by simple solution blending process, which was capable of abstracting hydrogen atoms from polymers containing active C--H groups upon exposure to ultraviolet （UV） radiation. The cross-linking can be completed with a relatively long wavelength UV light （365 nm）. The approach has been applied to methacrylate and styrenic polymers such as commercial poly（methylmethacrylate） （PMMA）, poly（iso-butylmethacrylate） （PiBMA） and poly（4-methylstyrene） （PMS）. The cross-linked networks enhanced dielectric properties and solvent resistance of the thin films. The bottom-gate organic field-effect transistors （OFETs） through all solution processes on plastic substrate were fabricated. The OFET devices showed low voltage operation and steep subthreshold swing at relatively small gate dielectric capacitance.
基金supported by the Key Technologies R&D Program of Xiamen(No.3502Z20231057)Industry Leading Key Projects of Fujian Province(No.2022H0057)+2 种基金the National Natural Science Foundation of China(No.21975212)High-Level Talent Start-Up Foundation of Xiamen Institute of Technology for financial support(No.YKJ23017R)Graduate Science and Technology Innovation Program of Xiamen University of Technology(No.YKJCX2023194).
文摘LiMnxFe1-xPO_(4) is a promising cathode candidate due to its high security and the availability of a high 4.1 V operating voltage and high energy density.However,the poor electrochemical kinetics and structural instability currently hinder its broader application.Herein,inspired by the hydrogen-bonded cross-linking and steric hindrance effect between short-chain polymer molecules(polyethylene glycol-400,PEG-400),the pomegranate-type LiMn_(0.5)Fe_(0.5)PO_(4)-0.5@C(P-LMFP@C)cathode materials with 3D ion/electron dual-conductive network structure were constructed through ball mill-assisted spray-drying method.The intermolecular effects of PEG-400 promote the spheroidization and uniform PEG coating of LMFP precursor,which prevents agglomeration during sintering.The 3D ion/electron dual-conductive network structure in P-LMFP@C accelerates the Li^(+)transport kinetics,improving the rate performance and cycling stability.As a result,the designed P-LMFP@C has remarkable electrochemical behavior,boasting excellent capacity retention(98%after 100 cycles at the 1C rate)and rate capability(91 mAh·g^(-1)at 20C).Such strategy introduces a novel window for designing high-performance olivine cathodes and offers compatibility with a range of energy storage materials for diverse applications.
文摘AIM:To compare simultaneous corneal collagen cross-linking(CXL)with intracorneal ring segment(ICRS)implantation versus successive ICRS followed by CXL and detect the impact of the timing of CXL after ICRS implantation in the successive method.METHODS:This is a retrospective study of the records of three groups of patients.Group 1 of 28 patients were operated on with simultaneous ICRS implantation and CXL,group 2 of 32 patients had ICRS implantation followed by CXL after 1mo,and group 3 of 38 patients had ICRS implantation followed by CXL after 3mo.The three groups had follow-up visits after 6,12,and 24mo.RESULTS:The preoperative data,age,and gender differences among 3 groups revealed no significant differences.The postoperative spherical equivalent and best-corrected visual acuity were improved significantly in all groups compared to the baseline,which were more evident in groups 1 and 2.The differences between preoperative and postoperative mean values of mean of K readings(Km)and maximum K reading(Kmax)at 6mo were 4.66 and 4.1 D in group 1,4.43 and 4.64 D in group 2,but 3.2 and 3.4 D in group 3,respectively.The spherical aberrations and the vertical coma showed significant postoperative changes in all groups,and trefoil showed nonsignificant changes.CONCLUSION:Simultaneous and sequential ICRS implantation and CXL at 1mo has similar Km and Kmax better postoperative changes than when both surgeries were done at three-month intervals.
基金Supported by the Social Development Grant of Shaanxi Province(No.2022SF-404)the Science and Technology Program of Xi’an,China(No.23YXYJ0010,No.23YXYJ0037)+1 种基金the Research Project of Xi’an Health Commission(No.2024ms05)the Technology Innovation Supporting Program of Shaanxi(No.2024RS-CXTD-11).
文摘AIM:To investigate the response of the anterior and posterior corneal surface in femtosecond laser-assisted convex stromal lenticule addition keratoplasty(SLAK)combined with cross-linking(CXL)for treating keratoconus at the first 3mo of follow-up.METHODS:In this prospective observational study,20 eyes of 20 keratoconus patients who underwent SLAK combined with CXL were included.The morphological indices in keratometry and elevation data were recorded from the Sirius at baseline and 1 and 3mo postoperatively.The mean values of maximum keratometry(K_(max)),flat keratometry(K_(1)),and steep keratometry(K_(2))at the central,3-mm,5-mm,and 7-mm areas were measured from the curvature map.The changes in anterior and posterior corneal elevation under the best-fit sphere(BFS)radius at seven points horizontally of the center,3-mm,5-mm,and 7-mm area from the center at both nasal(N)and temporal(T)side were measured from elevation map.RESULTS:For the front corneal curvature,K_(1),and K_(2) at 3-mm,5-mm,and 7-mm of the anterior corneal surface increased significantly 1mo postoperatively(all P<0.05)and remained unchanged until 3mo(P>0.05).For the back corneal curvature,K_(1) and K_(2) along the 3-mm back meridian significantly decreased after month 1(P=0.002,0.077,respectively).Posterior K_(2)-readings along the 5-mm and 7-mm did not change after surgery(P>0.05).Anterior BFS decreased 1mo(P<0.001)postoperatively but remained unchanged until 3mo after SLAK(P>0.05).There was no change in posterior BFS before and after the surgery(P>0.05).Anterior elevation at N5,N3,central,and T5 points and posterior elevation at central and T7 points shifted backward 1mo postoperatively(all P<0.05)and remained stable until 3mo(P>0.05).CONCLUSION:The myopic SLAK combined with CXL is an economical alternative for stabilizing the corneal surface in severe keraoconus.“Pseudoprogression”occurs in the early phase postoperatively,but it is not an indicator of keratoconus progression.
基金financial support from several corporate sponsors.Contributions were made by the National Natural Science Foundation of China(Grant No.32071332)Shenzhen Science and Technology Innovation Project(Grant No.JCYJ20210324095802006)+2 种基金Ningbo Bureau of Science and Technology(Grant No.2023Z187)TransEasy Medical Tech.Co.,Ltd.(Grant No.2021114)Shenzhen University MedTech Innovation Fund(2023YG027).
文摘Aging is a persistent topic of interest,with skin aging as its most visible manifestation,characterized by a reduction in intact collagen and elastic fibers in the dermis.Hyaluronic acid,a vital component of the extracellular matrix present in the skin,has become a mainstream method for skin rejuvenation through injections.However,the rapid degradation of pure hyaluronic acid,combined with insufficient maintenance duration and often limited therapeutic effects,presents significant challenges for injectable treatments.Additionally,low patient compliance due to discomfort from needles penetrating the dermal layer further complicates its use.In this review,we summarize and compare existing interventions for skin aging,focusing on strategies to prolong the degradation cycle of hyaluronic acid,including variations in cross-linking modalities and injection techniques.We conclude that the injection of cross-linked modified hyaluronic acid via microneedles represents a promising approach to extend the degradation cycle,offering valuable insights for current therapeutic strategies.
基金financial support from the National Natural Science Foundation of China[grant number 21878299]。
文摘Polymer binders possess significant potential in alleviating the volume expansion issues of silicon-based anodes,yet remain challenging due to insufficient interfacial interactions with individual components(Si,C,and Cu)of the anode.Herein,we report the synthesis of a stable three-dimensional network structure of the PAA-PEA(polyacrylic acid-polyether amines)polymer binder through intermolecular physicochemical dual cross-linking.By incorporating polar functional groups,the binder molecules not only form strong C-O-Si,N-Si,O=C-O-C,and O=C-O-Cu covalent bonds but also enhance non-covalent interactions with Si,C,and Cu,thereby improving adhesion between the binder and each interface of the anode.Furthermore,weak hydrogen bonds,acting as"sacrificial bonds",dissipate energy and disperse accumulated stress,improving the material flexibility.Due to the high mechanical stability of the framework,which combines both rigidity and flexibility and the coupling effect at the three interfaces,the movement and separation of electrode components are effectively restrained,significantly enhancing the cycling stability of silicon-graphite anodes.The PAA-PEA 2000 electrode exhibits a capacity retention of 78% after 500 cycles at a current density of 0.2 A g^(-1).This work provides insights into the mechanism of binders and guides the design of polymer binders for high-performance Si-based electrodes.
基金supported by the National Key Research and Development Program of China (No. 2022YFB3704700(2022YFB3704702))the National Natural Science Foundation of China (No. 52473096)+1 种基金Major Scientific and Technological Innovation Project of Shandong Province (No. 2021CXGC010901)Taishan Scholar Program
文摘In this study,a novel cost-effective methodology was developed to enhance the gas barrier properties and permselectivity of unfilled natural rubber(NR)/polybutadiene rubber(BR)composites through the construction of a heterogeneous structure using pre-vulcanized powder rubber to replace traditional fillers.The matrix material is composed of a blend of NR and BR,which is widely used in tire manufacturing.By incorporating pre-vulcanized trans-1,4-poly(isoprene-co-butadiene)(TBIR)rubber powder(pVTPR)with different cross-linking densities and contents,significant improvements in the gas barrier properties and CO_(2)permselectivity of the NR/BR/pVTPR composites were observed.The results indicated that compared to NR/BR/TBIR composites prepared through direct blending of NR,BR,and TBIR,the NR/BR/pVTPR composites exhibited markedly superior gas barrier properties.Increasing the cross-linking density of pVTPR resulted in progressive enhancement of the gas barrier properties of the NR/BR/pVTPR composite.For example,the addition of 20 phr pVTPR with a cross-linking density of 346 mol/m^(3)resulted in a 79%improvement in the oxygen barrier property of NR/BR/pVTPR compared to NR/BR,achieving a value of 5.47×10^(-14)cm^(3)·cm·cm^(-2)·s^(-1)·Pa^(-1).Similarly,the nitrogen barrier property improved by 76%compared to NR/BR,reaching 2.4×10^(-14)cm^(3)·cm·cm^(-2)·s^(-1)·Pa^(-1),which is 28%higher than the conventional inner liner material brominated butyl rubber(BIIR,PN2=3.32×10^(-14)cm^(3)·cm·cm^(-2)·s^(-1)·Pa^(-1)).Owing to its low cost,exceptional gas barrier properties,superior adhesion to various tire components,and co-vulcanization capabilities,the NR/BR/pVTPR composite has emerged as a promising alternative to butyl rubber in the inner liner of tires.Furthermore,by fine-tuning the cross-linking density of pVTPR,the high-gas-barrier NR/BR/pVTPR composites also demonstrated remarkable CO_(2)permselectivity,with a CO_(2)/N2 selectivity of 61.4 and a CO_(2)/O_(2)selectivity of 26.12.This innovation provides a novel strategy for CO_(2)capture and separation,with potential applications in future environmental and industrial processes.The multifunctional NR/BR/pVTPR composite,with its superior gas barrier properties and CO_(2)permselectivity,is expected to contribute to the development of safer,greener,and more cost-effective transportation solutions.
基金China Postdoctoral Science Foundation (2023M733451)Dalian Innovation Team in Key Areas(2020RT06)Engineering Research Center for Key Aromatic Compounds and LiaoNing Key Laboratory,Liaoning Provincial Natural Science Foundation (Doctoral Research Start-up Fund 2024-BSBA-37)。
文摘Selective hydrogenation of furfural to furfuryl alcohol is a great challenge in the hydrogenation field due to thermodynamic preference for hydrogenation of C=C over C=O.Herein,a novel Al_(2)O_(3)/C-u hybrid catalyst,composed of N-modified dendritic carbon networks supporting Al_(2)O_(3)nanoparticles,was successfully prepared via carbonizing the freeze-dried gel from spontaneous cross-linking of alginate,Al3+and urea.The obtained carbon-supported Al_(2)O_(3)hybrid catalyst has a high ratio (31%) of Al species in pentahedral-coordinated state.The introduction of urea enhances the surface N content,the ratio of pyrrolic N,and specific surface area of catalyst,leading to improved adsorption capacity of C=O and the accessibility of active sites.In the furfural hydrogenation reaction with isopropyl alcohol as hydrogen donor,Al_(2)O_(3)/C-u catalyst achieved a 90%conversion of furfural with 98.0% selectivity to furfuryl alcohol,outperforming that of commercial γ-Al_(2)O_(3).Moreover,Al_(2)O_(3)/C-u demonstrates excellent catalytic stability in the recycling tests attributed to the synergistic effect of abundant weak Lewis acid sites and the anchoring effect of the carbon network on Al_(2)O_(3)nanoparticles.This work provides an innovative and facile strategy for fabrication of carbon-supported Al_(2)O_(3)hybrid catalysts with rich AlVspecies,serving as a high selective hydrogenation catalyst through MPV reaction route.
文摘A controlled cross-linking polymerization containing intra- and intermolecular reactions was designed based on random coil morphology of macromolecules in solution. The soluble intramolecular cross-linked maeromolecule （ICM） was successfully synthesized in the system with PVA and MDI. We found an especial dissolving phenomenon, namely the semi-soluble phenomenon when some gels dissolved in DMF. The chain growth process of ICMs was investigated by Transmission electron microscopy （TEM） pictures of samples at different reacting times, in addition, TEM pictures show ICMs have three kinds of styles in structure, viz. ＂globule structure＂, ＂nubby structure＂ and the intervenient between the above two structures, and the efflux time of the ICMs was measured by an Ubbelohde viscosimeter, it was found that the efflux time decreases with the degree ofcrosslink increasing.
文摘Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of significant,novel,and high-impact research in the fields of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.
基金National Natural Science Foundation of China(11875039)Shanxi Scholarship Council of China(2023-033)+2 种基金Fundamental Research Program of Shanxi Province(202303021221071)China Baowu Low Carbon Metallurgical Innovation Foundation(2022)2023 Anhui Major Industrial Innovation Plan Project。
文摘The in-flight heating process of cerium dioxide(CeO_(2))powders was investigated through experiments and numerical simulations.In the experiment,CeO_(2)powder(average size of 30μm)was injected into radio-frequency(RF)argon plasma,and the temperatures were measured using a DPV-2000 monitor.A model combining the electromagnetism,thermal flow,and heat transfer characteristics of powder during in-flight heating in argon plasma was proposed.The melting processes of CeO_(2)powders of different diameters,with and without thermal resistance effect,were investigated.Results show that the heating process of CeO_(2)powder particles consists of three main stages,one of which is relevant to a dimensionless parameter known as the Biot number.When the Biot value≥0.1,thermal resistance increases significantly,especially for the larger powders.The predicted temperature of the particles at the outlet(1800–2880 K)is in good agreement with the experimental result.
基金Funded in part by the National Key Research and Development Program of China(No.2023YFB4006302)。
文摘We successfully incorporated phenyl groups into a small-molecule quaternary ammonium cross-linker and synthesized cross-linked polybenzimidazole membranes via a one-step cross-linking process.Compared with conventional quaternary ammonium-crosslinked benzimidazole membranes,the introduction of phenyl groups significantly increases the free volume within the membrane.After phosphoric acid doping,the benzimidazole membrane with larger free volume retains more phosphoric acid compared to conventional quaternary ammonium-crosslinked membranes,forming an extensive hydrogen-bonding network that effectively enhances its anhydrous proton conductivity.The anhydrous proton conductivity reaches 91 mS·cm^(-1)at 160℃,substantially higher than that of conventional quaternary ammonium-crosslinked membranes with the same mass fraction.Benefiting from the improved conductivity,the membrane electrode assembly exhibits reduced ohmic polarization,achieving a peak power density of 792 mW·cm^(-2)at 160℃.
基金Sichuan Science and Technology Program(2025ZNSFSC1341)Fundamental Research Funds for the Central Universities(J2022-090,25CAFUC04087)。
文摘The hot compression deformation behavior of Mg-6Zn-1Mn-0.5Ca(ZM61-0.5Ca)and Mg-6Zn-1Mn-2Sn-0.5Ca(ZMT612-0.5Ca)alloys was investigated at deformation temperatures ranging from 250℃to 400℃and strain rates varying from 0.001 s^(-1) to 1 s^(-1).The results show that the addition of Sn promotes dynamic recrystallization(DRX),and CaMgSn phases can act as nucleation sites during the compression deformation.Flow stress increases with increasing the strain rate and decreasing the temperature.Both the ZM61-0.5Ca and ZMT612-0.5Ca alloys exhibit obvious DRX characteristics.CaMgSn phases can effectively inhibit dislocation motion with the addition of Sn,thus increasing the peak fl ow stress of the alloy.The addition of Sn increases the hot deformation activation energy of the ZM61-0.5Ca alloy from 199.654 kJ/mol to 276.649 kJ/mol,thus improving the thermal stability of the alloy.For the ZMT612-0.5Ca alloy,the optimal hot deformation parameters are determined to be a deformation temperature range of 350–400℃and a strain rate range of 0.001–0.01 s^(-1).
文摘Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of signifi cant,novel,and high-impact research in the fi elds of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.
基金National MCF Energy R&D Program(2024YFE03260300)。
文摘Refractory metals,including tungsten(W),tantalum(Ta),molybdenum(Mo),and niobium(Nb),play a vital role in industries,such as nuclear energy and aerospace,owing to their exceptional melting temperatures,thermal durability,and corrosion resistance.These metals have body-centered cubic crystal structure,characterized by limited slip systems and impeded dislocation motion,resulting in significant low-temperature brittleness,which poses challenges for the conventional processing.Additive manufacturing technique provides an innovative approach,enabling the production of intricate parts without molds,which significantly improves the efficiency of material usage.This review provides a comprehensive overview of the advancements in additive manufacturing techniques for the production of refractory metals,such as W,Ta,Mo,and Nb,particularly the laser powder bed fusion.In this review,the influence mechanisms of key process parameters(laser power,scan strategy,and powder characteristics)on the evolution of material microstructure,the formation of metallurgical defects,and mechanical properties were discussed.Generally,optimizing powder characteristics,such as sphericity,implementing substrate preheating,and formulating alloying strategies can significantly improve the densification and crack resistance of manufactured parts.Meanwhile,strictly controlling the oxygen impurity content and optimizing the energy density input are also the key factors to achieve the simultaneous improvement in strength and ductility of refractory metals.Although additive manufacturing technique provides an innovative solution for processing refractory metals,critical issues,such as residual stress control,microstructure and performance anisotropy,and process stability,still need to be addressed.This review not only provides a theoretical basis for the additive manufacturing of high-performance refractory metals,but also proposes forward-looking directions for their industrial application.
文摘The development of polymer nanoparticle composites with enhanced thermal and antibacterial properties is essential for next-generation biomedical materials.However,conventional polymers often exhibit limited bioactivity and poor resistance to degradation,restricting their functional applications.The novelty of this study involves the combination of the bio-derived cross-linker 2,5-bis(aminomethyl)furan(BAF)into poly(methylmethacrylate)PMMA to form a cross-linked network incorporated with various ratios of ZnO nanoparticles(ZnO NPs),resulting in improved biological and thermal properties.The surface morphologies,material crystallinity,and thermal degradation properties of the synthesized BAF-PMMA/ZnO were investigated using Scanning Electron microscopy(SEM),Energy-Dispersive X-ray spectroscopy(EDX),X-ray diffraction(XRD),andThermogravimetric characterization technique(TGA),respectively.The prepared BAF-PMMA/ZnO nanocomposites showed an enhancement in the crystallinity after increasing the ratio of ZnO NPs compared to the amorphous cross-linked BAF-PMMA polymer.The thermal stability of nanocomposites was significantly enhanced after the introduction of ZnO NPs into crosslinked BAF-PMMA polymer.The resultant nanocomposites BAF-PMMA/ZnO were examined as antibacterial agents against the Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)bacterial strains.The results showed that most BAF-PMMA/ZnO nanocomposites have antibacterial activity against both bacterial species compared to the pure cross-linked BAF-PMMA polymer.The BAF-PMMA/ZnO 10 wt.%sample shows the highest inhibition zone of(16.3±0.33)against E.coli.These outcomes demonstrate that such nanocomposites offer a viable pathway towardmultipurpose biomaterials with exceptional structural and biological features.
