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Ultrahigh strength of cage-like polymeric nitrogen surpassing diamond under high pressure
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作者 Hui Liang Di Wang +4 位作者 Rui Xu Hao Chen Dan Zhou Yunwei Zhang Quan Li 《Matter and Radiation at Extremes》 2026年第1期103-110,共8页
We report first-principles predictions of a cage-like polymeric nitrogen phase(cage-N)composed of interlocked N10 clusters stabilized by mixed sp^(2)/sp^(3) hybridization.Under high pressure,cage-N exhibits exceptiona... We report first-principles predictions of a cage-like polymeric nitrogen phase(cage-N)composed of interlocked N10 clusters stabilized by mixed sp^(2)/sp^(3) hybridization.Under high pressure,cage-N exhibits exceptional mechanical performance,including an ideal compressive strength of 343 GPa at a pressure of 300 GPa,~33% higher than that of diamond.This ultrahigh strength arises from the synergistic interplay between its three-dimensional covalent framework and hybridized bonding topology,which enables isotropic stress accommodation and dynamic electronic rearrangement.These results establish cage-N as a promising non-carbon ultrahard material and provide a bonding-driven route toward designing superhard frameworks under extreme conditions. 展开更多
关键词 compressive strength mixed sp sp hybridization cage polymeric nitrogen hybridized bonding topologywhich mechanical performance interlocked n clusters ultrahigh strength first principles predictions
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Molecular dynamics insights into wax formation-How polymeric inhibitors shape crude oil flow
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作者 Wyclif Kiyingi Ji-Xiang Guo +1 位作者 Rui-Ying Xiong Chen-Hao Gao 《Petroleum Science》 2025年第5期2233-2245,共13页
Molecular-level interactions between polymeric inhibitors and wax crystals are essential for mitigating wax deposition in crude oils,a major operational and environmental challenge.This study investigates the mechanis... Molecular-level interactions between polymeric inhibitors and wax crystals are essential for mitigating wax deposition in crude oils,a major operational and environmental challenge.This study investigates the mechanisms by which specific inhibitors target wax crystals to prevent aggregation.Extracted wax and inhibitor were characterized using gas chromatography,X-ray diffraction,and spectroscopy to determine the molecular structures.The wax primarily comprised of straight-chain nC28 alkanes,while the inhibitor was an ethylene/vinyl acetate copolymer.Rheological tests demonstrated a reduced gelation point upon inhibitor addition.Molecular dynamics(MD)simulations,performed using the COMPASS II force field,revealed interactions at the molecular level.Structural validation of molecules was done through comparative analysis of the experimental infrared and simulated vibrational analysis spectra whereas that of the rhombohedral wax crystal was achieved using the Pawley method,yielding a Profile R-factor of 9.26%.Morphological studies revealed five symmetrically unique facets,with the(110)plane being the fastestgrowing due to its inter-planar distance and attachment energy(-157.25 kcal/mol).Adsorption energy calculations(-180 kcal/mol)confirmed that the inhibitor effectively disrupted crystal growth on the surface by adsorbing its polar section onto the wax surface while repelling the non-polar groups,thereby reducing waxaggregation. 展开更多
关键词 Molecular dynamics COLLOIDS Crystal growth Adsorption energy polymeric inhibitor
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Viscoelastic modeling of the diffusion of polymeric pollutants injected into a pipe flow
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作者 T.Chinyoka O.D. Makinde 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2013年第2期166-178,共13页
This study focuses on the transient analysis of nonlinear dispersion of a polymeric pollutant ejected by an external source into a laminar pipe flow of a Newtonian liquid under axi-symmetric conditions.The influence o... This study focuses on the transient analysis of nonlinear dispersion of a polymeric pollutant ejected by an external source into a laminar pipe flow of a Newtonian liquid under axi-symmetric conditions.The influence of density variation with pollutant concentration is approximated according to the Boussinesq approximation and the nonlinear governing equations of momentum,pollutant concentration are obtained together with and Oldroyd-B constitutive model for the polymer stress.The problem is solved numerically using a semi-implicit finite difference method.Solutions are presented in graphical form for various parameter values and given in terms of fluid velocity,pollutant concentration,polymer stress components,skin friction and wall mass transfer rate.The model can be a useful tool in understanding the dynamics of industrial pollution situations arising from improper discharge of hydrocarbon pollutants into,say,water bodies.The model can also be quite useful for available necessary early warning methods for detecting or predicting the scale of pollution and hence help mitigate related damage downstream by earlier instituting relevant decontamination measures. 展开更多
关键词 Axi-symmetric flow·polymeric pollutant dispersion·Oldroyd-B model Buoyancy forces·Semi-implicit finite difference method
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Roles of extracellular polymeric substances in arsenic accumulation and detoxification by cell wall intact and mutant strains of Chlamydomonas reinhardtii 被引量:1
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作者 Sadiq Naveed Qingnan Yu +3 位作者 Katarzyna Szewczuk-Karpisz Chunhua Zhang Shafeeq-Ur Rahman Ying Ge 《Journal of Environmental Sciences》 2025年第6期142-154,共13页
Arsenic(As)pollution seriously threatens human and ecological health.Microalgal cell wall and extracellular polymeric substances(EPS)are known to interactwith As,but their roles in the As resistance,accumulation and s... Arsenic(As)pollution seriously threatens human and ecological health.Microalgal cell wall and extracellular polymeric substances(EPS)are known to interactwith As,but their roles in the As resistance,accumulation and speciation inmicroalgae remain unclear.Here,we used two strains of Chlamydomonas reinhardtii,namely CC-125(wild type)and CC-503(cell walldeficientmutant),to examine the algal growth,EPS synthesis,As adsorption,absorption and transformation under 10–1000μg/L As(III)and As(V)treatments for 96 h.In both strains,the As absorption increased after the EPS removal,but the growth,As adsorption,and transformation of C.reinhardtii declined.The CC-125 strain was more tolerant to As stress and more efficient in EPS production,As accumulation,and redox transformation than CC-503,irrespective of EPS presence or absence.Three-dimension excitation-emission matrix(3DEEM)and attenuated total reflectance infrared spectroscopy(ATR-IR)analyses showed that As was bound with functional groups in the EPS and cell wall,such as-COOH,NH and-OH in proteins,polysaccharides and amino acids.Together,this study demonstrated that EPS and cell wall acted as barriers to lower the As uptake by C.reinhardtii.However,the cell wall mutant strain wasmore susceptible to As toxicity due to lower EPS induction and higher As absorption. 展开更多
关键词 Extracellular polymeric substances Cell wall ARSENIC ACCUMULATION Speciation MICROALGAE
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Harnessing S-scheme junctions for enhanced CO_(2) photoreduction:molecular bonding of copper(Ⅱ)complexes onto K-doped polymeric carbon nitride via microwave heating 被引量:2
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作者 Ming-Yu Heng Hong-Lei Shao +5 位作者 Jie-Ting Sun Qian Huang Shu-Ling Shen Guang-Zhi Yang Yu-Hua Xue Shu-Ning Xiao 《Rare Metals》 2025年第2期1108-1121,共14页
Photocatalytic conversion of CO_(2) is pivotal for mitigating the global greenhouse effect and fostering sustainable energy development.Nowadays,polymeric carbon nitride(PCN)has gained widespread application in CO_(2)... Photocatalytic conversion of CO_(2) is pivotal for mitigating the global greenhouse effect and fostering sustainable energy development.Nowadays,polymeric carbon nitride(PCN)has gained widespread application in CO_(2) solar reduction due to its excellent visible light response,suitable conduction band position,and good cost-effectiveness.However,the amorphous nature and low conductivity of PCN limit its photocatalytic efficiency by leading to low carrier concentrations and facile electron–hole recombination during photocatalysis.Addressing this bottleneck,in this study,potassium-doped PCN(KPCN)/copper(Ⅱ)-complexed bipyridine hydroxyquinoline carboxylic acid(Cu(Ⅱ)(bpy)(H_(2)hqc))composite catalysts were synthesized through a multistep microwave heating process.In the composite,the formation of an S-scheme junction facilitates the enrichment of more negative electrons on the conduction band of KPCN via intermolecular electron–hole recombination between Cu(Ⅱ)(bpy)(H_(2)hqc)(CuPyQc)and KPCN,thereby promoting efficient photoreduction of CO_(2) to CO.Microwave heating enhances the amidation reaction between these two components,achieving the immobilization of homogeneous molecular catalysts and forming amidation chemical bonds that serve as key channels for the S-scheme charge transfer.This work not only presents a new PCN-based catalytic system for CO_(2) reduction applications,but also offers a novel microwave-practical approach for immobilizing homogeneous catalysts. 展开更多
关键词 Photocatalytic CO_(2)reduction Microwave synthesis polymeric carbon nitride Amide bond Sscheme
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OVERSHOOTS IN STRESS AND FREE ENERGY CHANGE DURING THE FLOWINDUCED CRYSTALLIZATION OF POLYMERIC MELT IN SHEAR FLOW 被引量:1
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作者 张洪斌 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2010年第4期657-666,共10页
The effect of pre-shear flow on the subsequent crystallization process of polymeric melt was investigated and a flow-induced crystallization (FIC) model based on the conformation tensor incorporating the pre-shear e... The effect of pre-shear flow on the subsequent crystallization process of polymeric melt was investigated and a flow-induced crystallization (FIC) model based on the conformation tensor incorporating the pre-shear effect was proposed. The model is capable of predicting the overshoot phenomena of the stress and the flow-induced free energy change of the polymeric system at high pre-shear rates. Under the condition of flow, the increase in the activated nuclei number was contributed by the flow-induced free energy change, which showed an overwhelming effect on the nuclei formation during the pre-shear process at high shear rates. The half crystallization time (t1/2) of polypropylene (PP) as functions of pre-shear rate and pre-shear time at different crystallization temperatures was predicted and compared with the experiment data. Both numerical and experimental results showed that t1/2 of PP decreased dramatically when the flow started but leveled off at long times. It was found that two transformation stages in t1/2 existed within a wide range of shear rates. For the first stage where the melting polymer experienced a relatively weak shear flow, the acceleration of crystallization kinetics was mainly contributed by the steady value of free energy change while in the second stage for high shear rates, strong overshoot in flow-induced free energy change occurred and the crystallization kinetics was thus significantly enhanced. The overshoots in stress and flow-induced free energy change reflected an important role of flow on the primary nucleation especially when the flow was strong enough. 展开更多
关键词 Crystallization kinetics Half crystallization time flow Model Conformation tensor
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Polymeric nanocarriers for therapeutic gene delivery 被引量:1
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作者 Jiayuan Zhang Xinyu Yang +3 位作者 Zhichao Chang Wenwei Zhu Yuhua Ma Haisheng He 《Asian Journal of Pharmaceutical Sciences》 2025年第1期1-25,共25页
The recent commercialization of gene products has sparked significant interest in gene therapy,necessitating efficient and precise gene delivery via various vectors.Currently,viral vectors and lipid-based nanocarriers... The recent commercialization of gene products has sparked significant interest in gene therapy,necessitating efficient and precise gene delivery via various vectors.Currently,viral vectors and lipid-based nanocarriers are the predominant choices and have been extensively investigated and reviewed.Beyond these vectors,polymeric nanocarriers also hold the promise in therapeutic gene delivery owing to their versatile functionalities,such as improving the stability,cellar uptake and endosomal escape of nucleic acid drugs,along with precise delivery to targeted tissues.This review presents a brief overview of the status quo of the emerging polymeric nanocarriers for therapeutic gene delivery,focusing on key cationic polymers,nanocarrier types,and preparation methods.It also highlights targeted diseases,strategies to improve delivery efficiency,and potential future directions in this research area.The review is hoped to inspire the development,optimization,and clinical translation of highly efficient polymeric nanocarriers for therapeutic gene delivery. 展开更多
关键词 polymeric nanocarriers Therapeutic gene delivery Cationic polymers DISEASES Transfection efficiency STRATEGIES
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Efficient Preparation of Polypeptides through Accelerated Polymerization of N-Carboxyanhydrides in Continuous Flow
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作者 Yu-Ke Qian Shao-Bo Feng Zi-Yuan Song 《Chinese Journal of Polymer Science》 2025年第11期2000-2008,I0008,共10页
The preparation of polypeptide materials in continuous flow reactors shows great potential with improved reproducibility and scalability.However,conventional polypeptide synthesis from the polymerization of N-carboxya... The preparation of polypeptide materials in continuous flow reactors shows great potential with improved reproducibility and scalability.However,conventional polypeptide synthesis from the polymerization of N-carboxyanhydride(NCA)is conducted at relatively slow rates,requiring long tubing or ending up with low-molecular-weight polymers.Inspired by recent advances in accelerated NCA polymerization,we report the crown-ether-catalyzed,rapid synthesis of polypeptide materials in cosolvents in flow reactors.The incorporation of low-polarity dichloromethane and the use of catalysts enabled fast conversion of monomers in 30 min,yielding well-defined polypeptides(up to 30 k Da)through a 20-cm tubing reactor.Additionally,random or block copolypeptides were efficiently prepared by incorporating a second NCA monomer.We believe that this work highlights the accelerated polymerization design in flow polymerization processes,offering the continuous production of polypeptide materials. 展开更多
关键词 POLYPEPTIDE flow polymerization Accelerated polymerization N-CARBOXYANHYDRIDE Solvent effect
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High-performance Flow Chemistry Platform for Scalable Continuous Synthesis of Branched Block Copolymers with Precise Chain Structures
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作者 Bang-Bang Wang Zhuang Zhang +3 位作者 Jing-Tao Wang Li Pan Yue-Sheng Li Dong-Po Song 《Chinese Journal of Polymer Science》 2025年第3期457-467,共11页
Cutting-edge research has primarily focused on flow synthesis of linear block copolymers,lacking the ability for manipulating chain architectures for more extensive applications.Herein,we develop a flow chemistry plat... Cutting-edge research has primarily focused on flow synthesis of linear block copolymers,lacking the ability for manipulating chain architectures for more extensive applications.Herein,we develop a flow chemistry platform for the continuous microflow synthesis of bottlebrush block copolymers(BBCPs)using a grafting-through method.This involves performing ring-opening metathesis polymerization(ROMP)of two different macromonomers within two microfluidic reactors connected in series.The microflow environment allows for complete monomer conversion within a few tens of seconds,benefiting from the superior mixing efficiency achieved in Z-shaped channels as indicated by both theoretical simulations and experimental results.Consequently,a library of well-defined BBCPs of up to 528 distinct samples can be produced within one day through automation of the continuous procedure,while keeping precise control on degree of polymerization(DP<4)and polydispersity indices(PDI<1.2).The synthetic method is generally applicable to different macromonomers with different compositions and contour lengths,yielding libraries of branched block copolymers with great diversity in physiochemical properties and chain architectures.This work presents a powerful platform for high-throughput production of branched copolymers,significantly lowering the costs of the materials for real applications. 展开更多
关键词 Continuous flow synthesis Ring opening metathesis polymerization Branched copolymer
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Dynamic analysis of polymeric fluid in shear flow for dumbbell model with internal viscosity
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作者 杨晓东 R.V.N.MELNIK 《Journal of Central South University》 SCIE EI CAS 2008年第S1期17-20,共4页
The dynamic analysis of semi-flexible polymers,such as DNA molecules,is an important multiscale problem with a wide range of applications in science and bioengineering.In this contribution,a dumbbell model with intern... The dynamic analysis of semi-flexible polymers,such as DNA molecules,is an important multiscale problem with a wide range of applications in science and bioengineering.In this contribution,a dumbbell model with internal viscosity was studied in steady shear flows of polymeric fluid.The tensors with moments other than second moment were approximated in the terms of second moment tensor.Then,the nonlinear algebraic equation of the second moment conformation tensor was calculated in closed form.Finally,substituting the resulting conformation tensor into the Kramers equation of Hookean spring force,the constitutive equations were obtained.The shear material properties were discussed for different internal viscosities and compared with the results of Brownian dynamics simulation. 展开更多
关键词 dynamic simulation polymeric fluid INTERNAL VISCOSITY SHEAR THINNING
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Terpolymers of alkyl methacrylate-trans anethole-1,2,3,6-tetrahydrophthalic anhydride copolymers:A low dosage and high-efficiency cold flow improver for diesel fuel
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作者 Bowen Xu Jiahao Chen +3 位作者 Lulu Cui Xinyue Li Yuan Xue Sheng Han 《Chinese Chemical Letters》 2025年第5期606-609,共4页
The addition of cold flow improvers(CFIs)is considered as the optimum strategy to improve the cold flow properties(CFPs)of diesel fuels,but this strategy is always limited by the required large dosage.To obtain low-do... The addition of cold flow improvers(CFIs)is considered as the optimum strategy to improve the cold flow properties(CFPs)of diesel fuels,but this strategy is always limited by the required large dosage.To obtain low-dosage and high-efficiency CFIs for diesel,1,2,3,6-tetrahydrophthalic anhydride(THPA)was introduced as a third and polar monomer to enhance the depressive effects of alkyl methacrylatetrans anethole copolymers(C_(14)MC-TA).The terpolymers of alkyl methacrylate-trans anethole-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-TA-THPA)were synthesized and compared with the binary copolymers of C_(14)MC-TA and alkyl methacrylate-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-THPA).Results showed that C_(14)MC-THPA achieved the best depressive effects on the cold filter plugging point(CFPP)and solid point(SP)by 11℃and 16℃at a dosage of 1250 mg/L and monomer ratio of 6:1,while 1500mg/L C_(14)MC-TA(1:1)reached the optimal depressive effects on the CFPP and SP by 12℃and 18℃.THPA introduction significantly improved the depressive effects of C_(14)MC-TA.Lower dosages of C_(14)MCTA-THPA in diesel exerted better improvement effects on the CFPP and SP than that of C_(14)MC-TA and C_(14)MC-THPA.When the monomer ratio and dosage were 6:0.6:0.4 and 1000 mg/L,the improvement effect of C_(14)MC-TA-THPA on diesel reached the optimum level,and the CFPP and SP were reduced by 13℃and 19℃,respectively.A 3D nonlinear surface diagram fitted by a mathematical model was also used for the first time to better understand the relationships of monomer ratios,dosages,and depressive effects of CFIs in diesel.Surface analysis results showed that C_(14)MC-TA-THPA achieved the optimum depressive effects at a monomer ratio of 6:0.66:0.34 and dosage of 1000 mg/L,and the CFPP and SP decreased by 14℃ and 19℃,respectively.The predicted results were consistent with the actual ones.Additionally,the improvement mechanism of these copolymers in diesel was also explored. 展开更多
关键词 Diesel fuel High-efficiency Cold flow properties Cold flow improvers Mathematical model
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Recent advances in electrochemiluminescence based on polymeric luminophores
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作者 Sijia Zhou Tianyi Zhou +5 位作者 Yuhua Hou Wang Li Yanfei Shen Songqin Liu Kaiqing Wu Yuanjian Zhang 《Chinese Chemical Letters》 2025年第5期109-123,共15页
Developing efficient,non-toxic,and low-cost emitters is a key issue in promoting the applications of electrochemiluminescence(ECL).Among varied ECL emitters,polymeric emitters are attracting dramatically increasing in... Developing efficient,non-toxic,and low-cost emitters is a key issue in promoting the applications of electrochemiluminescence(ECL).Among varied ECL emitters,polymeric emitters are attracting dramatically increasing interest due to tunable structure,large surface area,brilliant transfer capability,and sustainable raw materials.In this review,we present a general overview of recent advances in developing polymeric luminophores,including their structural and synthetic methodologies.Methods rooted in straightforward unique structural modulation have been comprehensively summarized,aiming at enhancing the efficiency of ECL along with the underlying kinetic mechanisms.Moreover,as several conjugated polymers were just discovered in recent years,promising prospects and perspectives have also been deliberated.The insight of this review may provide a new avenue for helping develop advanced conjugated polymer ECL emitters and decode ECL applications. 展开更多
关键词 ELECTROCHEMILUMINESCENCE polymeric luminophores MECHANISMS EFFICIENCY
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EFFECT OF INTERNAL VISCOSITY OF POLYMERIC FLUIDS UNDER STRONG EXTENSIONAL FLOWS
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作者 杨晓东 Roderick V.N.Melnik 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2009年第2期189-193,共5页
The dumbbell model with internal viscosity for a dilute polymer solution is investigated based on a balance of viscous drag and restoring Brownian forces.An approximate method is used to obtain the solution of extensi... The dumbbell model with internal viscosity for a dilute polymer solution is investigated based on a balance of viscous drag and restoring Brownian forces.An approximate method is used to obtain the solution of extensional stress in closed form in the case of steady flow.For different internal viscosities,this parametric study shows different asymptotic regimes of the extensional viscosity as a function of strain rate.This analysis may explain the attenuation of pressure drop in strong flows from a phenomeno... 展开更多
关键词 polymeric fluid Internal viscosity Extensional viscosity.
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The effects of polymeric binder on microstructural characteristics of powder sheet additive manufacturing
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作者 Wenyou Zhang Zhe Cai +3 位作者 Asli Coban Ramesh Babu Wajira Mirihanage Rocco Lupoi 《Additive Manufacturing Frontiers》 2025年第4期176-183,共8页
A novel laser-based additive manufacturing approach of metal additive manufacturing using powder sheets(MAPS)has been introduced recently.The method utilizes polymer-bound powder sheets for metal AM as a feedstock,ins... A novel laser-based additive manufacturing approach of metal additive manufacturing using powder sheets(MAPS)has been introduced recently.The method utilizes polymer-bound powder sheets for metal AM as a feedstock,instead of loose powders.Conventional laser beam powder bed fusion(LPBF)additive manufacturing(AM)is among the most widespread 3D printing technologies.However,LPBF faces challenges related to safety and the impracticality of changing materials due to its reliance on loose powders.Thus,MAPS demonstrates the capability to overcome the limitations of LPBF by offering enhanced safety and the ability to print multi-material structures without the risk of material cross-contamination.As a part of developing processes,we investigate the effects of polymeric binder content on the printability and microstructural characteristics of MAPS-printed stainless steel 316 L.The results indicate that the average layer thickness of solidified material improves as the scanning speed decreases from 1000 mm/s to 50 mm/s across three different polymeric binder contents:10 wt%,20 wt%,and 30 wt%PCL.Additionally,a higher polymeric binder content(i.e.20 wt%and 30 wt%)in the powder sheets reduces the likelihood of crack formation.Electron backscatter diffraction(EBSD)analysis reveals that an increase in scanning speed promotes the formation of more equiaxed grains,while an increase in polymer content results in a reduction in grain size.These findings provide valuable insights into optimizing MAPS configurations for enhanced productivity and functionality in metal component manufacturing. 展开更多
关键词 Powder sheet MICROSTRUCTURE polymer content PRINTABILITY Additive manufacturing
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Multifunctional GelMA hydrogel doped with spermidine-ferrocene polymeric nanoparticles for accelerative diabetic wound healing
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作者 Lina Xie Xiaohe Zhang +4 位作者 Xiaobo Wang Zhen Zhang Tianqi Nie Jun Wu Xiaojun Xu 《Chinese Chemical Letters》 2025年第11期382-388,共7页
Diabetic wounds are among the most challenging chronic wounds to heal,due to the presence of multiple factors,including continuous oxidative stress,impaired vascular integrity,and biofilm formation.The development of ... Diabetic wounds are among the most challenging chronic wounds to heal,due to the presence of multiple factors,including continuous oxidative stress,impaired vascular integrity,and biofilm formation.The development of innovative treatment strategies is of paramount importance for the management of diabetic wounds.Stemmed from the pleiotropic physicochemical properties of ferrocene and spermidine,this essay reported the ferrocene-spermidine co-polymer(Fc S)for the first time through facile amidation reaction.Molecular dynamics simulation revealed its self-assembly through hydrogen bonds,van der Waals forces instead of traditional nanoprecipitation.The self-assembled nanoparticles were demonstrated to exhibit great antioxidant property on cells to facilitate their migration and angiogenesis.Moreover,the integration with photocuring hydrogel,gelatin methacrylate(Gel MA),to construct Fc S nanoparticles loaded wound dressing(Gel MA@Fc S)further confirmed the potential on promoting diabetic wound enclosure through enhancement of re-epithelization and collagen deposition.Together with its great biocompatibility and biosafety,Gel MA@Fc S is expected to be developed into a wound dressing for clinical diabetic wounds management. 展开更多
关键词 FERROCENE SPERMIDINE HYDROGEL polymeric nanoparticles Diabetic wound healing
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Efficacy of functionalized MWCNT-based polymeric nanofluids for enhancing oil recovery in reservoirs
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作者 Weeam Al Shidi Tarek Ganat +2 位作者 Najeebullah Lashari Usman Taura Hamoud Al-Hadrami 《Petroleum Research》 2025年第4期902-911,共10页
Polymer-based enhanced oil recovery boosts production in depleted oil fields.However,harsh reservoir conditions,such as high salinity and temperature,often reduce its effectiveness.This study explores the use of a new... Polymer-based enhanced oil recovery boosts production in depleted oil fields.However,harsh reservoir conditions,such as high salinity and temperature,often reduce its effectiveness.This study explores the use of a new aqueous polymeric nanofluid to overcome these challenges.The polymer we evaluated was partially hydrolyzed polyacrylamide(HPAM)with 40%hydrolysis and a molecular weight of 10 MD.The objective of this investigation was to enhance the efficacy of HPAM by incorporating multiwalled carbon nanotubes functionalized with COOH(MwCNT-COOH).Various tests were conducted to evaluatethe polymeric nanofluid,including Fourier transform infrared spectroscopy for bonding detection,viscoelastic behavior analysis under static and dynamic shear rates,interfacial tension measurements using the spinning drop technique,and wettability alteration studies through contact angle measurements.The efficiency of the new nanofluid in enabling oil recovery was compared to that of conventional polymers through core flooding experiments.The optimized polymeric nanoparticle injection resulted in a 10%increase in recuperation.This suggests that polymeric nanofluids may be a plausible solution for enhancing oil recovery-a solution that could boost oil production in reservoirs. 展开更多
关键词 Multiwall carbon nanotube Enhanced oil recovery NANOPARTICLES polymeric solution RESERVOIRS
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Photoswitchable dual-color fluorescent polymeric nanoparticles for self-erased time-resolved information encryption and anti-counterfeiting
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作者 Hong Wang Yong Tian +4 位作者 Tiancheng Wu Shun He Jiaxi Cui Jian Chen Xudong Chen 《Chinese Chemical Letters》 2025年第7期468-472,共5页
Photoswitchable fluorescent polymeric nanoparticles were widely concerned because of their excellent features including the flexible design,easy preparation and functionalization,and thus exhibited great application p... Photoswitchable fluorescent polymeric nanoparticles were widely concerned because of their excellent features including the flexible design,easy preparation and functionalization,and thus exhibited great application potential in information encryption,anti-counterfeiting,but remained challenging in improving the security.Herein,we described a self-erased time-resolved information encryption via using photoswitchable dual-color fluorescent polymeric nanoparticles(PDFPNs)containing two fluorescence dyes(blue and red)and photochromic spiroxazine derivatives.In view of the different thermo-induced isomerization rates of photochromic spiroxazine derivatives in different flexible substrates,the decoloration rate of PDFPNs can be programmatically tuned by regulating ratio between rigid polymer and flexible polymer.Therefore,after ultraviolet light(UV)irradiation,correct information could only be recognized in preestablished time during the self-erased process.Our results indicated that PDFPNs exhibited fast photo-responsibility(2 min),high fluorescence contrast,well-pleasing photo-reversibility(>20 times),and programmable thermo-responsiveness(24 s-6 h).We thus demonstrated their application in the selferased time-resolved information encryption and anti-counterfeiting with high security. 展开更多
关键词 Photoswitchable dual-color fluorescence polymeric nanoparticles FRET Self-erasure Time-resolved information encryption
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Ambient-Stable Polymeric Nitrogen Achieved through Multi-Stage Computational Design
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作者 Jiani Lin Jianfu Li +2 位作者 Yong Liu Jianan Yuan Xiaoli Wang 《Chinese Physics Letters》 2025年第7期298-309,共12页
The four-decade quest for synthesizing ambient-stable polymeric nitrogen,a promising high-energy-density material,remains an unsolved challenge in materials science.We develop a multi-stage computational strategy empl... The four-decade quest for synthesizing ambient-stable polymeric nitrogen,a promising high-energy-density material,remains an unsolved challenge in materials science.We develop a multi-stage computational strategy employing density functional tight-binding-based rapid screening combined with density functional theory refinement and global structure searching,effectively bridging computational efficiency with quantum accuracy.This integrated approach identifies four novel polymeric nitrogen phases(Fddd,P3221,I4m2,and𝑃P6522)that are thermodynamically stable at ambient pressure.Remarkably,the helical𝑃6522 configuration demonstrates exceptional thermal resilience up to 1500 K,representing a predicted polymeric nitrogen structure that maintains stability under both atmospheric pressure and high-temperature extremes.Our methodology establishes a paradigm-shifting framework for the accelerated discovery of metastable energetic materials,resolving critical bottlenecks in theoretical predictions while providing experimentally actionable targets for polymeric nitrogen synthesis. 展开更多
关键词 ambient stable polymeric nitrogen polymeric nitrogen density functional tight binding density functional theory density functional theory refinement global structure searching global structure searchingeffectively bridging computational efficiency quantum accuracythis
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Design-simulation-manufacturing-assessment framework for geometric optimization of polymeric heart valves toward enhanced durability
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作者 Tianle Xu Zihan Zhu +3 位作者 Yunhan Cai Shunping Chen Jia Guo Shengzhang Wang 《Bio-Design and Manufacturing》 2025年第5期835-846,I0067-I0068,共14页
Owing to their excellent biocompatibility and potential for durability enhancement,polymeric heart valves(PHVs)are emerging as a promising alternative to traditional prostheses.Unlike conventional materials,PHVs can b... Owing to their excellent biocompatibility and potential for durability enhancement,polymeric heart valves(PHVs)are emerging as a promising alternative to traditional prostheses.Unlike conventional materials,PHVs can be manufactured under precise design criteria,enabling targeted performance improvements.This study introduces a geometric optimization strategy for enhancing the durability of PHVs.The finite element method(FEM)is combined with a dip-molding technique to develop a novel polymeric aortic valve with improved mechanical properties.The tri-leaflet geometry is parameterized using B-spline curves,and the maximum stress in the valve is reduced from 2.4802 to 1.7773 MPa using a multiobjective optimization algorithm NSGA-II(non-dominated sorting genetic algorithm II).Pre-optimized and optimized valve prototypes were fabricated via dip-molding and evaluated during pulsatile-flow tests and accelerated wear tests.The optimized design meets the ISO 5840 standards,with an effective orifice area of 2.019 cm^(2),a regurgitant fraction of 5.693%,and a transvalvular pressure gradient of 7.576 mmHg.Moreover,the optimized valve maintained its structural integrity and functionality over 14 million cycles of the accelerated wear test,whereas the unoptimized valve failed after two million cycles.These findings confirm that the FEM-based geometric optimization method enhances both the mechanical performance and durability of PHVs. 展开更多
关键词 polymeric heart valve DURABILITY Optimization Finite element method(FEM) Dip-molding
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Polymeric carbon nitride for photocatalytic overall water splitting:Modification strategies and recent advances
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作者 Anna Dai Zhenxiong Huang +3 位作者 Li Tian Zheng Zhang Xiangjiu Guan Liejin Guo 《Chinese Journal of Structural Chemistry》 2025年第8期88-100,共13页
Solar-driven photocatalytic overall water splitting(POWS)has emerged as a sustainable pathway for hydrogen production,yet faces intrinsic challenges in developing robust catalysts that balance efficiency,stability,and... Solar-driven photocatalytic overall water splitting(POWS)has emerged as a sustainable pathway for hydrogen production,yet faces intrinsic challenges in developing robust catalysts that balance efficiency,stability,and cost-effectiveness.Polymeric carbon nitride(PCN)represents as a promising metal-free photocatalyst for hydrogen production due to the merits of unique electronic structure and exceptional thermal stability.Nevertheless,limited by rapid charge recombination and insufficient oxidative capability,little success has been achieved on pristine PCN photocatalyst in POWS.In this context,recent advances have demonstrated multi-dimensional modification strategies for improving POWS performance.Based on the fundamental principles of photocatalysis,this review discusses the advantages and challenges of PCN-based photocatalysts in POWS systems.With critical evaluation on one-step excitation systems and Z-scheme two-step excitation systems,modification strategies including crystallinity engineering,supramolecular precursor design,cocatalyst modulation,and construction of PCN-based heterojunctions and homojunctions were highlighted by introducing representative advances in POWS application over the past five years.Future perspectives for PCN-based photocatalysts are proposed,aiming to provide new insights for the design of advanced photocatalytic system for efficient POWS. 展开更多
关键词 PHOTOCATALYSIS Overall water splitting Hydrogen production polymeric carbon nitride Modification strategies
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