期刊文献+
共找到33,994篇文章
< 1 2 250 >
每页显示 20 50 100
Advances in magnesium-incorporated polymeric scaffolds:A next-generation strategy for enhanced wound healing
1
作者 Sundaravadhanan Lekhavadhani Sushma Babu +1 位作者 Abinaya Shanmugavadivu Nagarajan Selvamurugan 《Journal of Magnesium and Alloys》 2026年第1期96-116,共21页
Wound management continues to present major clinical challenges,often necessitating therapeutic strategies that extend beyond conventional dressings,which provide only passive protection.Magnesium(Mg),a biologically i... Wound management continues to present major clinical challenges,often necessitating therapeutic strategies that extend beyond conventional dressings,which provide only passive protection.Magnesium(Mg),a biologically indispensable element,has attracted considerable attention for its multifaceted role in wound repair,including modulation of inflammatory responses,stimulation of fibroblast and keratinocyte proliferation,promotion of angiogenesis,and enhancement of collagen synthesis.However,the direct application of Mg formulations is limited by uncontrolled Mg ion(Mg^(2+))release,localized cytotoxicity at elevated concentrations,and inadequate mechanical stability at the wound site.To address these challenges,Mg-incorporated polymeric scaffolds have been developed as advanced delivery platforms.These systems integrate the regenerative capacity of Mg with the tunable properties of polymers,enabling controlled degradation,mechanical reinforcement,and sustained Mg^(2+)release to establish a favorable microenvironment for tissue repair.This review critically examines the role of Mg in wound healing and the effectiveness of polymeric matrices for controlled Mg^(2+)delivery.It further provides a comprehensive evaluation of recent advances in Mg-incorporated polymeric scaffolds,including nanofibers,hydrogels,and sponges,with emphasis on fabrication strategies,structural characteristics,and therapeutic efficacy.Key challenges,such as optimizing ion release kinetics,enhancing scaffold stability,and facilitating clinical translation,are also discussed.Collectively,this work underscores the potential of Mg-polymeric scaffolds as a next-generation platform for advanced wound care and highlights perspectives for future research and development. 展开更多
关键词 MAGNESIUM polymeric scaffolds Wound healing Inflammation ANGIOGENESIS Tissue regeneration
在线阅读 下载PDF
Ultrahigh strength of cage-like polymeric nitrogen surpassing diamond under high pressure
2
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
在线阅读 下载PDF
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
3
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
原文传递
Roles of extracellular polymeric substances in arsenic accumulation and detoxification by cell wall intact and mutant strains of Chlamydomonas reinhardtii 被引量:1
4
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
原文传递
Polymeric nanocarriers for therapeutic gene delivery 被引量:1
5
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
暂未订购
Ambient-Stable Polymeric Nitrogen Achieved through Multi-Stage Computational Design
6
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
原文传递
Multifunctional GelMA hydrogel doped with spermidine-ferrocene polymeric nanoparticles for accelerative diabetic wound healing
7
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
原文传递
Molecular dynamics insights into wax formation-How polymeric inhibitors shape crude oil flow
8
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
原文传递
Recent advances in electrochemiluminescence based on polymeric luminophores
9
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
原文传递
Polymeric micelle-hydrogel composites design for biomedical applications
10
作者 Hongyi Li Huiyun Wen +7 位作者 He Zhang Jin Li Xiang Cao Jiaqing Zhang Yutao Zheng Saipeng Huang Weiming Xue Xiaojun Cai 《Chinese Chemical Letters》 2025年第5期74-81,共8页
Designing advanced hydrogels with controlled mechanical properties,drug delivery manner and multifunctional properties will be beneficial for biomedical applications.However,the further development of hydrogel is limi... Designing advanced hydrogels with controlled mechanical properties,drug delivery manner and multifunctional properties will be beneficial for biomedical applications.However,the further development of hydrogel is limited due to its poor mechanical property and structural diversity.Hydrogels combined with polymeric micelles to obtain micelle-hydrogel composites have been designed for synergistic enhancement of each original properties.Incorporation polymeric micelles into hydrogel networks can not only enhance the mechanical property of hydrogel,but also expand the functionality of hydrogel.Recent advances in polymeric micelle-hydrogel composites are herein reviewed with a focus on three typical micelle incorporation methods.In this review,we will also highlight some emerging biomedical applications in developing micelle-hydrogel composite with multiple functionalities.In addition,further development and application prospects of the micelle-hydrogels composites have also been addressed. 展开更多
关键词 polymeric micelle Hydrogel composites Incorporation methods Biomedical applications Local tumor treatment Tissue engineering
原文传递
Photoswitchable dual-color fluorescent polymeric nanoparticles for self-erased time-resolved information encryption and anti-counterfeiting
11
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
原文传递
Design-simulation-manufacturing-assessment framework for geometric optimization of polymeric heart valves toward enhanced durability
12
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
暂未订购
Polymeric carbon nitride for photocatalytic overall water splitting:Modification strategies and recent advances
13
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
原文传递
Polymeric micelles:“magic bullets”for cancer treatment
14
作者 Yue Gao Meihong Zhang +6 位作者 Qian Chen Yuxin Lin Chuanbin Wu Xin Pan Ling Guo Tze Ning Hiew Zhengwei Huang 《Bio-Design and Manufacturing》 2025年第6期1103-1125,I0046-I0076,共54页
Nanocarriers are an efficient drug delivery tool used for cancer treatment.Among various nanocarriers,polymeric micelles(PMs)have garnered attention in recent years due to their excellent properties,including improved... Nanocarriers are an efficient drug delivery tool used for cancer treatment.Among various nanocarriers,polymeric micelles(PMs)have garnered attention in recent years due to their excellent properties,including improved solubility of insoluble drugs,enhanced targeting and accumulation of drugs at the cancer site,increased sensitivity of cancer cells to chemotherapeutic drugs,and prolonged circulation time.This review summarizes the preparation methods,characterization,advantages,and classification of PMs as drug delivery systems for oncology therapeutics.In particular,the self-assembly mechanisms of active ingredients into PMs,the anticancer activities of PMs associated with various cell death pathways,and the research cases of PMs as drug delivery vehicles in cancer therapy are described.Finally,this review summarizes the status of the clinical trials and real-world applications of PMs and briefly analyzes the reasons for the unsatisfactory commercialized states.This review supports further research on the role of PMs as nanocarriers in cancer therapy and adds insights for the successful clinical translation of PM-based products. 展开更多
关键词 Cancer therapy polymeric micelles Drug delivery systems Cell death pathways Clinical application
在线阅读 下载PDF
Research Progress in the Polymeric Nitrogen with High Energy Density
15
作者 Jie Zhang Guo Chen +2 位作者 Chengfeng Zhang Yuxuan Xu Xianlong Wang 《Chinese Physics Letters》 2025年第5期69-79,共11页
Polymeric nitrogen is a potential high-energy-density material with the advantages of high energy density, easy availability of raw materials, and non-pollution. The design and synthesis of polymeric nitrogen are impo... Polymeric nitrogen is a potential high-energy-density material with the advantages of high energy density, easy availability of raw materials, and non-pollution. The design and synthesis of polymeric nitrogen are important in the research field of energetic materials. The cubic gauche nitrogen was successfully synthesized at high pressure in the diamond anvil cell, which stimulated the theoretical and experimental investigations. To date, several hundred kinds of polymeric nitrogen have been reported. This review introduces the progressive development of polymeric nitrogen with high energy density, the challenges faced by the synthesized polymeric nitrogen under high-pressure,and the importance to improve the stability of polymeric nitrogen at ambient pressure. Furthermore, alternative methods for synthesizing polymeric nitrogen under moderate conditions are also presented. In this field, more efforts are needed to develop strategies for stabilizing more polymeric nitrogen to ambient conditions, especially the stability of free surfaces. 展开更多
关键词 polymeric nitrogen cubic gauche nitrogen theoretical experimental investigations energetic materials raw materials design synthesis high energy density diamond anvil cell
原文传递
Microbial community and dynamic changes of extracellular polymeric substances in relation to plastisphere of disposable surgical masks in natural aquatic environment
16
作者 Ling ZHANG Yuxin ZHOU +6 位作者 Zixian ZHU Feifei YAN Luxi TAN Chunyan WEI Zihao WANG Qingfeng CHEN Ying ZHANG 《Journal of Oceanology and Limnology》 2025年第2期502-514,共13页
In the context of global COVID-19 epidemic preparedness,the extensive use of disposable surgical masks(DSM)may lead to its emergence as a main new source of microplastics in the environment.Nowadays,DSMs have become a... In the context of global COVID-19 epidemic preparedness,the extensive use of disposable surgical masks(DSM)may lead to its emergence as a main new source of microplastics in the environment.Nowadays,DSMs have become a non-negligible source of plastic waste in aquatic environment,however,less research has been done on DSM after biofilm colonization in freshwater environment.The study investigated the microbial community of DSM-associated biofilms by 16S rRNA gene sequencing.Analysis of the microbial community in the middle and inner/outer layers of the DSM showed that the middle layer was different from the remaining two layers and that potential pathogens were enriched only in the middle layer of the DSM.Herein,we focused on the middle layer and explored the characterization properties and extracellular polymeric substances(EPS)components changes during biofilm formation.The results showed that the EPS components varied with the biofilm incubation time.As the formation of biofilm,the protein(PN)and polysaccharide(PS)in EPS showed an overall increasing trend,and the growth of PS was well synchronized with PN.Three fluorescent components of EPS were determined by the three-dimensional excitation emission matrix(3D-EEM),including humic acid-like,fulvic acid-like,and aromatic protein-like components.The percentage of fluorescent components varied with increasing biofilm development time and then stabilized.Fourier transform infrared spectroscopy(FTIR)characterization results elucidated the emergence of oxygen-containing functional groups during biofilm formation.Moreover,the hydrophilicity increased with biofilm development.In conclusion,the environmental behavior and ecological risks of DSM in aquatic environment deserve urgent attention in future studies. 展开更多
关键词 BIOFILM disposable surgical masks(DSM) extracellular polymeric substances(EPS) microbial community plastisphere
在线阅读 下载PDF
Organic solvent nanofiltration polymeric membranes:Recent progress,applications,challenges,and perspectives
17
作者 Qianwen Su Xiuming Zhang +1 位作者 Daohui Zhao Ming Li 《Chinese Journal of Chemical Engineering》 2025年第6期196-208,共13页
Organic solvent nanofiltration(OSN) is an efficient,low-energy and environmentally friendly phase-free separation process.Obviously,the core of OSN lies in the fabrication of solvent-resistant nanofiltration membranes... Organic solvent nanofiltration(OSN) is an efficient,low-energy and environmentally friendly phase-free separation process.Obviously,the core of OSN lies in the fabrication of solvent-resistant nanofiltration membranes.Although membrane materials reported in the literature such as 2D membranes,porous organic cages,etc.have the potential for ultra-high performance,polymeric membranes provide key advantages in mass production and processability.Therefore,this review focuses on polymeric materials for OSN.This review summarizes the recent progress of polymeric materials,including emerging and traditional polymeric membranes.Then,a summary of recent progress about strategies developed for perm-selective nanofilms are presented,followed by a brief overview of commercial membrane technology for OSN.Finally,major challenges of OSN and future research directions are presented.Close interaction between the academic research and practical application would help improve greener and more sustainable manufacturing processes. 展开更多
关键词 Organic solvent nanofiltration(OSN) Molecular separation Porous materials Solvent-resistant polymeric membranes Commercial applications
在线阅读 下载PDF
The effects of polymeric binder on microstructural characteristics of powder sheet additive manufacturing
18
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
在线阅读 下载PDF
改性sMAO负载茂金属催化剂用于淤浆法聚乙烯的制备
19
作者 王立娟 邓修远 +3 位作者 杨琦 陈斯佳 姜涛 李健 《合成树脂及塑料》 北大核心 2026年第1期35-39,共5页
采用不同的氟代酚类化合物对固体甲基铝氧烷(sMAO)进行改性得到改性sMAO载体,以双(1-丁基-3-甲基环戊二烯基)二氯化锆为茂金属活性组分负载到改性sMAO载体上,得到负载型茂金属催化剂,并用于乙烯淤浆聚合。结果表明:以五氟苯酚、2,3,5,6... 采用不同的氟代酚类化合物对固体甲基铝氧烷(sMAO)进行改性得到改性sMAO载体,以双(1-丁基-3-甲基环戊二烯基)二氯化锆为茂金属活性组分负载到改性sMAO载体上,得到负载型茂金属催化剂,并用于乙烯淤浆聚合。结果表明:以五氟苯酚、2,3,5,6-四氟苯酚、八氟-4,4'-联苯酚为改性剂,制备的负载型茂金属催化剂的活性分别为2.312×10^(6),2.100×10^(6),2.040×10^(6) g/mol,与改性前相比提升了69%~90%。当改性剂为五氟苯酚时,得到的茂金属聚乙烯相对分子质量提高了约30%。 展开更多
关键词 茂金属催化剂 改性剂 负载 淤浆聚合 甲基铝氧烷
在线阅读 下载PDF
饥饿条件和添加硝酸盐的好氧颗粒污泥形成与稳定性优化
20
作者 李冬 蒋鹏飞 +2 位作者 李帅 傅思博 张杰 《哈尔滨工业大学学报》 北大核心 2026年第2期1-11,共11页
针对好氧颗粒污泥(aerobic granular sludge,AGS)工程应用中普遍存在的颗粒结构稳定性不足问题,提出延长水力停留时间(hydraulic retention time,HRT)与硝酸盐协同调控策略,旨在明确二者协同作用对AGS颗粒结构稳定性的强化机制。实验设... 针对好氧颗粒污泥(aerobic granular sludge,AGS)工程应用中普遍存在的颗粒结构稳定性不足问题,提出延长水力停留时间(hydraulic retention time,HRT)与硝酸盐协同调控策略,旨在明确二者协同作用对AGS颗粒结构稳定性的强化机制。实验设置了4组序批式反应器(SBR),即R0(对照组)、R1(单独外加硝酸盐)、R2(延长HRT控制饥饿条件)和R3(延长HRT结合外加硝酸盐)。以人工合成废水为底物,系统研究不同调控条件对AGS性能的影响。结果表明:通过延长HRT所造成的饥饿条件有效消耗了胞外聚合物(extracellular polymeric substances,EPS)中的多糖(polysaccharide,PS),从而显著提高了EPS中蛋白质(protein,PN)与PS的质量比,有效促进了颗粒污泥的密实化与结构稳定化。具体而言,R0、R1、R2和R3系统中颗粒污泥的完整性系数分别达84.26%、85.69%、95.13%和97.12%;EPS总质量分数分别为78.06、96.93、80.00和91.42 mg/g,PN与PS质量比分别为4.77、5.15、11.12和9.30。这表明延长HRT和硝酸盐共同调控显著加快了颗粒污泥形成,增强了颗粒污泥的结构强度。在污染物去除性能方面,R0、R1、R2和R3系统的化学需氧量平均去除率分别为89.01%、88.25%、83.94%和88.56%;总氮平均去除率分别达74.49%、82.50%、81.02%和81.41%。其中,R3系统表现出最佳的脱氮性能和污泥稳定性。微生物群落分析显示,R3系统内Proteobacteria门(相对丰度56.49%)占主导地位,尤其是在硝酸盐诱导的饥饿胁迫下,优势功能菌属Zoogloea(相对丰度16.13%)显著提高了EPS分泌量(97.40 mg/g),有效驱动了污泥颗粒化过程。这一结果进一步证实,通过硝酸盐调控实现微生物群落的定向优化,是提高AGS结构稳定性的一条有效途径。 展开更多
关键词 好氧颗粒污泥 胞外聚合物 盛宴/饥饿 PN与PS质量比
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部