期刊文献+
共找到2,088篇文章
< 1 2 105 >
每页显示 20 50 100
Recent Advances in Sustainable and Green Chemistry for Polyurethane-Based High-Performance Supercapacitor Electrodes
1
作者 Amr Mansi Sherief A.Al Kiey +8 位作者 S.Zein El Abedin Mohamed Bassyouni Ahmed R.Wassel Ahmed M.Yousif Yasser Elhenawy Alexandre Barras Sabine Szunerits Rabah Boukherroub Mohamed S.Hasanin 《Transactions of Tianjin University》 2025年第5期498-523,共26页
The increasing demand for sustainable energy storage solutions has intensified the focus on high-performance supercapaci-tors,known for their rapid charge/discharge capabilities,high power density,and long cycle life.... The increasing demand for sustainable energy storage solutions has intensified the focus on high-performance supercapaci-tors,known for their rapid charge/discharge capabilities,high power density,and long cycle life.Polyurethane(PU)-based materials have gained attention as promising candidates for supercapacitor electrodes,due to their flexibility,mechanical robustness,and tunable properties.It is important to clarify that PU typically does not contribute directly to charge storage via adsorption or pseudocapacitive mechanisms.Instead,PU serves as a flexible scaffold,a binder,or a precursor for the preparation of heteroatom-doped carbon materials upon thermal treatment.Thus,the term'PU-based'in this review refers to PU-supported or PU-derived composites,where PU enables structural or functional integration of active electrode Materi-als.Polyurethane composites incorporating graphene oxide have demonstrated a specific capacitance of 758.8 mF/cm^(2)with capacitance retention of 92%over 5,000 cycles.Other PU-based electrodes have achieved energy densities up to 22.5 Wh/kg and power densities of 1472.7 W/kg,reflecting their potential for high-performance energy storage applications.Despite these advantages,challenges,such as low intrinsic conductivity and the environmental impact of traditional synthesis methods,limit their widespread adoption.Conventional PU composites often incorporate conductive additives like carbon materi-als,metal oxides,or conductive polymers to enhance their electrochemical performance,yet these approaches may involve non-renewable or toxic components.Developing green energy materials that adhere to sustainability and green chemistry principles is crucial to address these limitations.This includes using renewable resources,environmentally friendly process-ing techniques,and recyclable materials to reduce the ecological footprint and meet the growing need for sustainable energy storage technologies.This review highlights current trends in developing eco-friendly supercapacitor materials,addressing key challenges such as limited conductivity and complex processing.It uniquely integrates green chemistry principles with advances in polyurethane composites,emphasizing sustainable feedstocks,heteroatom doping,and functional nanomateri-als.By combining these aspects,this review provides a comprehensive perspective not fully covered in existing literature. 展开更多
关键词 Biodegradable polyurethane sponge Porous carbon Starch nanoparticles Electrode materials SUPERCAPACITORS
在线阅读 下载PDF
An evidence-based review of the ethnomedicinal,phytochemical,and pharmacological properties of Typhonium flagelliforme
2
作者 Siti Aishah Mohammad Amin Yeun-Mun Choo 《Traditional Medicine Research》 2026年第5期1-13,共13页
Typhonium flagelliforme(TF)is a Southeast Asian medicinal plant traditionally used for cancer,respiratory disorders,gastrointestinal complaints,wound healing,inflammation,and general health.Contemporary studies valida... Typhonium flagelliforme(TF)is a Southeast Asian medicinal plant traditionally used for cancer,respiratory disorders,gastrointestinal complaints,wound healing,inflammation,and general health.Contemporary studies validate these uses,showing potent anticancer,immunomodulatory,anti-inflammatory,gastroprotective,antibacterial,antioxidant,and wound-healing activities.Ethanol,dichloromethane,methanol,and ethyl acetate extracts exhibit strong cytotoxicity against breast(MCF-7,T47D),lung(NCI-H23),colon(WiDr),and leukemia(CEM-ss,WEHI-3)cells via apoptosis,telomerase inhibition,HER2/neu and BCL-2 suppression,and antiangiogenesis.Notably,2-octenoic acid and 2-hexenoic acid show exceptional activity(IC₅₀=2.66 and 3.10μg/mL)against MCF-7 cells.TF also restores lymphocyte proliferation,enhances macrophage activity,increases both CD4+and CD8+T-cell levels,and modulates cytokines(TNF-α,IL-1α,IL-10).Gastroprotective,anti-ulcer,antibacterial,antioxidant,and wound-healing effects further support traditional claims.Key phytochemicals include flavonoids(isovitexin,kaempferol,vitexin),phenolics(vanillin,4-hydroxybenzaldehyde),phytosterols(β-sitosterol,campesterol,stigmasterol,daucosterol),chlorophyll derivatives(pheophorbides),and long-chain fatty acids(linoleic,linolenic,oleic,stearic).These findings highlight TF as a source of multifunctional bioactive compounds,warranting further pharmacokinetic,safety,and clinical evaluation for evidence-based therapeutic development. 展开更多
关键词 Typhonium flagelliforme ETHNOMEDICINE PHYTOCHEMICALS anticancer activity IMMUNOMODULATION
暂未订购
Flexible Mussel-inspired Hydrogel with Polyaniline and Polypyrrole for Transparent Wearable Strain Sensors:Investigation of Physical Properties,Self-healing,and Electrical Conductivity
3
作者 Ghazaleh Mirzaei Akbar Mirzaei Shahrzad Javanshir 《Chinese Journal of Polymer Science》 2026年第1期198-208,I0015,共12页
Conducting hydrogels have garnered significant interest in the field of wearable electronics.However,simultaneously achieving high transparency,high conductivity,strong adhesion,and self-healing ability within a short... Conducting hydrogels have garnered significant interest in the field of wearable electronics.However,simultaneously achieving high transparency,high conductivity,strong adhesion,and self-healing ability within a short time remains a major challenge.In this study,a multifunctional mussel-inspired hydrogel was synthesized in only 5 min,with polydopamine(PDA)-polypyrrole(Ppy)-polyaniline(PANi)and poly(vinyl alcohol)(PVA)nanoparticles incorporated into the polyacrylamide(PAM)network.The resulting hydrogel exhibited high transparency(about 90% light transmission in the range of 400-800 nm),high conductivity((95.4±0.4)×10^(-4)S/cm),tensile strength(32.60±1.03 k Pa),strain at break(904.46%±11.50%),and adhesive strength(30-60 k Pa).It also demonstrated rapid self-healing properties(about 48% strength recovery within 1h at 50℃)and water-dependent shape memory behavior.As a wearable strain sensor,the hydrogel successfully detected finger flexion,wrist movements,facial expression changes,and breathing with high sensitivity and stability.The calculated gauge factor(GF)was 7.44±0.31,which is higher than that of many previously reported hydrogels.Compared with previous oyster-inspired or Ppy-based hydrogels,our system showed a much shorter synthesis time,higher transparency,and enhanced multifunctionality.These findings highlight the potential of the proposed hydrogel for next-generation flexible electronics,e-skin,and biomedical monitoring devices. 展开更多
关键词 Electrical conductivity Mussel-inspired hydrogel Adhesive hydrogel Flexible hydrogel
原文传递
Bipolar and NIR-responsive Polyurethane Microspheres as a Bifunctional Adsorbent for Simultaneous Capture of Bacteria and Removal of Dyes
4
作者 Shi-Fan Chen Jia-Lin Su +5 位作者 Si-Xian Zhang Zhen Hu Jian-Xu Bao Xia-Yu Cha Wei-Feng Zhao Chang-Sheng Zhao 《Chinese Journal of Polymer Science》 2026年第2期315-330,I0007,共17页
Hospital wastewater contains complex pollutants,including residual organic dyes and antibiotic-resistant pathogens,posing severe risks to ecosystems and human health.Conventional adsorbents,constrained by monopolar fu... Hospital wastewater contains complex pollutants,including residual organic dyes and antibiotic-resistant pathogens,posing severe risks to ecosystems and human health.Conventional adsorbents,constrained by monopolar functional groups and limited surface sites,fail to remove both pollutants simultaneously.Here,we report an intelligent responsive polyurethane microsphere adsorbent doped with diallyl dimethylammonium chloride modified carbon nanotubes,termed as PUCD microspheres.The PUCD integrates bipolar adsorption sites,tunable micrometer-scale pores,and a near-infrared(NIR)-triggered in situ capture mechanism within a single platform,which achieves up to 98.3%dye removal,maintains strong adsorption performance across a wide pH range and retains 83.3%efficiency for rhodamine B after five cycles.Notably,the PUCD employs a temperature-responsive phase transition:under NIR irradiation,the microspheres undergo shrinkage,reducing the pore size to generate a‘polymer trap',enabling in situ capture of bacteria with>99%efficiencies for both Staphylococcus aureus and Escherichia coli.By immobilizing live bacteria,the PUCD microspheres substantially reduces the risk of pathogen desorption and toxin release.This promising platform offers a safe,efficient,and single-stage strategy for hospital wastewater purification,enabling the simultaneous elimination of dyes and pathogenic bacteria. 展开更多
关键词 Intelligent responsive adsorbent Tunable micrometer-sized pore Bipolar adsorption sites
原文传递
Unveiling the origins of Northern Thailand’s haze:comprehensive chemical characterization and source apportionment of PM_(2.5) using targeted molecular markers
5
作者 Supattarachai Saksakulkrai Somporn Chantara +2 位作者 Pavidarin Kraisitnitikul Deepchandra Srivastava Zongbo Shi 《Journal of Environmental Sciences》 2026年第1期635-648,共14页
Annual haze in Northern Thailand has become increasingly severe,impacting health and the environment.How-ever,the sources of the haze remain poorly quantified due to limited observational data on aerosol molecular tra... Annual haze in Northern Thailand has become increasingly severe,impacting health and the environment.How-ever,the sources of the haze remain poorly quantified due to limited observational data on aerosol molecular tracers.This study comprehensively investigates chemical composition of PM_(2.5),including both inorganic and organic compounds throughout haze and post-haze periods in 2019 at a rural site of Northern Thailand.Average PM_(2.5) concentrations during haze and post-haze period were 87±36 and 21±11μg/m^(3),respectively.Organic matter was the dominant contributor in PM_(2.5) mass,followed by water soluble inorganic ions and mineral dust.Molecular markers,including levoglucosan,dehydroabietic acid,and 4-nitrocatechol,and ions(Cl^(-),and K^(+)),were used to characterize low haze(PM_(2.5)<100μg/m^(3))and episodic haze(PM_(2.5)>100μg/m^(3)).Low haze is associated with local aerosols from agricultural waste burning,while episodic haze is linked to aged aerosols from mixed agricultural waste,softwood,and hardwood burning.Source apportionment incorporating these molecular markers in receptor modelling(Positive matrix factorization),identified three distinct biomass burning sources:mixed,local,and aged biomass burnings,contributing 31,19 and 13%of PM_(2.5) during haze period.During post-haze period,contributions shifted,with local biomass burning(32%)comparable to secondary sulfate(34%)and mixed dust and traffic sources(26%).These findings demonstrate that both regional and local sources con-tribute to severe haze,highlighting the need for integrated policies for cross-border cooperation as well as stricter regulations to reduce biomass burning in Northern Thailand and Southeast Asia. 展开更多
关键词 Chiang Mai Smoke haze Biomass burning PM_(2.5) Source apportionment Positive matric factorization
原文传递
Alkyl Alcohol Chain-length Mediated Steric Hindrance at Support Surface in Heterogeneous α-Diimine Ni Catalysts for Modulating Ethylene Polymerization
6
作者 Fan Yu Bin Dai +2 位作者 Ning Liu Bin-Yuan Liu Chen Zou 《Chinese Journal of Polymer Science》 2026年第2期331-340,I0007,共11页
Heterogeneous polymerization represents a widely employed method in the polyolefin industry.In recent years,various heterogenization strategies for late transition metal catalysts have been developed,enabling effectiv... Heterogeneous polymerization represents a widely employed method in the polyolefin industry.In recent years,various heterogenization strategies for late transition metal catalysts have been developed,enabling effective control of polymer morphology and optimization of catalytic performance.However,while most studies have focused on designing anchoring groups and advancing support approaches,systematic investigations into how the support influences the catalytic behavior of the late transition metal catalysts.In this work,we fabricated supported α-diimine nickel catalysts by functionalizing the ligand with alkyl alcohol chains of varying lengths and supporting them onto MgCl_(2)supports.The ethylene polymerization behavior of these catalysts was then investigated.By precisely adjusting the alkyl alcohol chain length,the distance between the catalytically active metal center and the support surface was modulated.This approach demonstrates that support-induced steric hindrance effect can be effectively regulated by controlling the separation distance between the metal center and the support surface. 展开更多
关键词 Ethylene polymerization Ni catalysts Α-DIIMINE Heterogeneous polymerization POLYETHYLENE
原文传递
Many-Body Enhancement of Excitonic Electron–Hole Recombination in Two-Dimensional Transition Metal Dichalcogenides
7
作者 Li Yao Xiang Jiang +1 位作者 Qijing Zheng Jin Zhao 《Chinese Physics Letters》 2026年第1期134-141,共8页
Electron–hole(e–h)recombination is a fundamental process that governs energy dissipation and device efficiency in semiconductors.In two-dimensional(2D)materials,the formation of tightly bound excitons makes exciton-... Electron–hole(e–h)recombination is a fundamental process that governs energy dissipation and device efficiency in semiconductors.In two-dimensional(2D)materials,the formation of tightly bound excitons makes exciton-mediated e–h recombination the dominant decay pathway.In this work,nonradiative e–h recombination within excitons in monolayer MoS_(2) is investigated using first-principles simulations that combine nonadiabatic molecular dynamics with GW and real-time Bethe–Salpeter equation(BSE)propagation.A two-step process is identified:rapid intervalley redistribution induced by exchange interaction,followed by slower phonon-assisted recombination facilitated by exciton binding.By selectively removing the screened Coulomb and exchange terms from the BSE Hamiltonian,their respective contributions are disentangled—exchange interaction is found to increase the number of accessible recombination pathways,while binding reduces the excitation energy and enhances nonradiative decay.A reduction in recombination lifetime by over an order of magnitude is observed due to the excitonic many-body effects.These findings provide microscopic insights for understanding and tuning exciton lifetimes in 2D transition-metal dichalcogenides. 展开更多
关键词 energy dissipation tightly bound excitons many body effects excitonic recombination nonadiabatic molecular dynamics e-h recombination decay pathwayin monolayer mos
原文传递
Challenges and Opportunities of Precision Polymer Chemistry 被引量:1
8
作者 Shiyong Liu 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2022年第10期1129-1130,共2页
Since Hermann Staudinger coined the revolutionary concept of macromolecules in 1920, synthetic polymers have served as a major game changer to our society and become indispensable in our daily lives. Unlike biomacromo... Since Hermann Staudinger coined the revolutionary concept of macromolecules in 1920, synthetic polymers have served as a major game changer to our society and become indispensable in our daily lives. Unlike biomacromolecules (e.g., DNA and proteins) possessing precise molar masses/chain sequences/topologies and specific biological functions, synthetic polymers are abiotic materials characterized by broad chain length distributions and undefined sequences. To bridge the gap between natural and synthetic polymers, the biomimetic synthesis of polymers with precise chain length, sequences and topologies has been long pursued and yet unmet in polymer science. 展开更多
关键词 PRECISE SEQUENCES SYNTHETIC
原文传递
Wet Deposition Fluxes and Related Atmospheric Chemistry at Three Sites in Mexico 被引量:1
9
作者 Rosa María Cerón Bretón Julia Griselda Cerón Bretón +4 位作者 Claudia Alejandra Aguilar Ucán Evangelina Ramírez Lara José Abraham Ortínez álvarez Carlos Montalvo Romero Carmen Guadalupe Carballo Pat 《Open Journal of Air Pollution》 2014年第1期1-9,共9页
Wet deposition was collected in Mexico City (MC), Metropolitan Area of Monterrey (MAM) and El Chico National Park (ECNP), during 2009 and 2010. pH, conductivity, Cl-, , Na+, K+, Ca2+ and Mg2+ were determined. In MC, s... Wet deposition was collected in Mexico City (MC), Metropolitan Area of Monterrey (MAM) and El Chico National Park (ECNP), during 2009 and 2010. pH, conductivity, Cl-, , Na+, K+, Ca2+ and Mg2+ were determined. In MC, sulphate levels were greater than nitrate levels, and NH4 had mixed sources (vehicular emissions and agriculture activities). MAM had markedly alkaline atmospheric deposition, Na+ and Cl-levels were unexpectedly high, especially during hurricane “Alex”. Low pH values were found in ECNP and nitrate concentrations were high, suggesting the influence of a local source (forest fires). Deposition fluxes (Kg.ha-1yr-1) for N-NO3, N-NH4 and S-SO4 were 1.36, 2.74 and 4.84 for MAM;7.27, 0.57 and 4.32 for ECNP;and 5.97, 4.96 and 6.78 for MC, respectively. Nitrogen deposition fluxes in ECNP were high considering that this site is a natural reserve. 展开更多
关键词 Acid DEPOSITION MEXICAN ATMOSPHERIC DEPOSITION Network Mexico WET DEPOSITION WET DEPOSITION FLUXES
在线阅读 下载PDF
Simulation of the oxidative metabolization pattern of netupitant,an NK1 receptor antagonist,by electrochemistry coupled to mass spectrometry
10
作者 Ruxandra Chira Jens Fangmeyer +4 位作者 Ioan O.Neaga Valentin Zaharia Uwe Karst Ede Bodoki Radu Oprean 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2021年第5期661-666,共6页
Considering the frequent use of netupitant in polytherapy,the elucidation of its oxidative metabolization pattern is of major importance.However,there is a lack of published research on the redox behavior of this nove... Considering the frequent use of netupitant in polytherapy,the elucidation of its oxidative metabolization pattern is of major importance.However,there is a lack of published research on the redox behavior of this novel neurokinin-1 receptor antagonist.Therefore,this study was performed to simulate the intensive hepatic biotransformation of netupitant using an electrochemically driven method.Most of the known enzyme-mediated reactions occurring in the liver(i.e.,N-dealkylation,hydroxylation,and Noxidation)were successfully mimicked by the electrolytic cell using a boron-doped diamond working electrode.The products were separated by reversed-phase high-performance liquid chromatography and identified by high-resolution mass spectrometry.Aside from its ability to pinpoint formerly unknown metabolites that could be responsible for the known side effects of netupitant or connected with any new perspective concerning future therapeutic indications,this electrochemical process also represents a facile alternative for the synthesis of oxidation products for further in vitro and in vivo studies. 展开更多
关键词 Netupitant Oxidative metabolism Neurokinin-1 antagonist EC/LC/MS
暂未订购
Thermochemistry of Ternary Complex Dy(Et_2dtc)_3(phen)
11
作者 朱丽 焦宝娟 +3 位作者 杨旭武 帅琪 高胜利 史启祯 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第4期452-457,共6页
The ternary solid complex was synthesized with sodium diethyldithiocarbamate (NaEt_2dtc), 1,10-phenanthroline (phen) and low hydrated dysprosium chloride in absolute ethanol by improved method of reference. The title ... The ternary solid complex was synthesized with sodium diethyldithiocarbamate (NaEt_2dtc), 1,10-phenanthroline (phen) and low hydrated dysprosium chloride in absolute ethanol by improved method of reference. The title complex was identified as the general formula of Dy(Et_2dtc)_3(phen) by chemical and elemental analyses. IR spectrum of the complex shows that the Dy^(3+) coordinated with six sulfur atoms of three NaEt_2dtc and two nitrogen atoms of phen. It is assumed that the coordination number of Dy^(3+) is eight.The enthalpy change of liquid-phase reaction of formation, Δ_rH~θ_m(l), is determined as (-19.091±0.015) kJ·mol^(-1) at 298.15 K by a microcalorimeter, and the enthalpy change of the solid-phase reaction of formation, Δ_rH~θ_m(s), is calculated as (139.641±0.482) kJ·mol^(-1) on the basis of a thermochemical cycle. The thermodynamic of reaction of formation was studied by changing the temperature of liquid-phase reaction. The constant-volume combustion energy of the complex, Δ_cU, is determined as (-16730.21±9.25) kJ·mol^(-1) by a precise rotating-bomb calorimeter at 298.15 K. Its standard enthalpies of combustion, Δ_cH~θ_m, and standard enthalpies of formation, Δ_fH~θ_m, are calculated as (-16749.42±9.25) kJ·mol^(-1) and (-2019.68±10.19) kJ·mol^(-1), respectively. 展开更多
关键词 Dy(Et_2dtc)_3(phen) MICROCALORIMETER thermodynamic constant-volume combustion energy standard mole enthalpy of formation rare earths
在线阅读 下载PDF
Green Chemistry Preparation and Characterization of Rice Husk Derived Silica Gel in Kenya
12
作者 Raphael Kungu Paul Njogu +1 位作者 Robert Kinyua Jackton Kiptoo 《Journal of Environmental Science and Engineering(A)》 2019年第6期225-240,共16页
Rice is a grass seed from Oryza glaberrima species also known as the African rice.In Kenya,rice is mostly grown in Central(Mwea)and Nyanza(Ahero,West Kano,Migori and Kuria)areas.Milling rice produces rice husks as by-... Rice is a grass seed from Oryza glaberrima species also known as the African rice.In Kenya,rice is mostly grown in Central(Mwea)and Nyanza(Ahero,West Kano,Migori and Kuria)areas.Milling rice produces rice husks as by-products which can be sources of valuable chemical products(silica gel,sodium silicate).In trials to produce silica gel from rice husks,rice husks were charred in a combustion chamber(30 min)then ashed in a Muffle furnace(Advantec KL-420)at different temperatures.The ashes were then leached with distilled water/acids to remove metal oxides.Sixty grams(60 g)of the leached RHA(Rice Husk Ash)was mixed with 300 mL of 3 M NaOH solution in a Pyrex 500 mL beaker and boiled at 100℃(1 h).The silica gel samples were characterized using several methods.Elemental analysis was done using TXRF(Total X-Ray Fluorescence),while FTIR(Fourier-Transform Infrared Spectroscopy)was used to obtain an infrared spectrum of absorption of the silica sample.Results of the analysis conform to local and international quality standards.The rice husks had an average moisture content of 7.07%and 1.00-2.00 mm diameter.And 1.74%of the rice husk had pore sizes of about 0.710 mm.The average ash content was 22.65%.At 600℃,leaching with water yielded 98.2%silica compared with 99.1%(H2SO4)and 96.9%(HCl).At 500℃,leaching with HCl/H2SO4 causes a decrease.At 500℃,the availability of SiO2 is more for water leached samples.At 400℃,water leaching gave 98.49%silica while HCl leaching was 97.85%silica and H2SO4 was 99.41%.Silica is a precursor of silica gel.Statistical analyses imply water leaching RHA instead of acid leaching at 500℃ will produce a significant amount of silica gel.The open burn samples produced equal or better SiO2(silica gel precursor)yields compared with the incineration samples.FTIR analysis of the silica gel sample compared well with adsorption peaks of silica gel in literature.XRD(X-Ray Diffraction)analysis produced a pattern consistent with other XRD patterns of silica gel published by other researchers. 展开更多
关键词 RICE husk CONVERSION SILICA GEL synthesis green chemistry IDEAL conditions
在线阅读 下载PDF
Effect of Different Kinetic Factors on the Thermochemistry of Sulfophosphoric Attack Reaction of Natural Phosphate Tunisian by DRC
13
作者 Olfa Lachkar-Zamouri Khemaies Brahim +1 位作者 Faten Bennour Ismail Khattech 《Advances in Materials Physics and Chemistry》 2018年第11期429-440,共12页
Mixture of phosphoric and sulfuric acid solutions has been used to investigate the dissolution of natural phosphates (PN) by DRC. The effect of concentration, particle size and stirring speed reaction is examined. The... Mixture of phosphoric and sulfuric acid solutions has been used to investigate the dissolution of natural phosphates (PN) by DRC. The effect of concentration, particle size and stirring speed reaction is examined. Thermochimique properties of each kinetic parameters reaction are determined. It was found that these parameters have a considerable effect on the thermochemical aspect of the attack reaction. It is known that the process of PN sulphophosphoric acid attack leads to the formation of dihydrate (CaSO4.2H2O: DH). The present work shows the precipitation of other residues their formula depends on factors studied. The increase in concentration leads to the formation of hemihydrate (CaSO4v1/2H2O:HH) beside DH for the low values of% H2SO4 due to the solubility of dihydrate on the etching solution and the precipitation of (Ca (H2PO4)2.2H2O) next of DH for low agitation values because of the lack of turbulence between the liquid phase and the solid phase which favors the precipitation of this latter compound. 展开更多
关键词 Thermochimique PHOSPHATE Ore Differential REACTION CALORIMETRY Concentration STRING Speed Particle Size
在线阅读 下载PDF
<i>Drymaria cordata</i>(Linn.) Willd (Caryophyllaceae): Ethnobotany, Pharmacology and Phytochemistry
14
作者 Ngansop Raymond Nono Kegah Laurence Nzowa +1 位作者 Luciano Barboni Azefack Léon Tapondjou 《Advances in Biological Chemistry》 2014年第2期160-167,共8页
In the present paper the isolation and characterization of seven major glycolipid classes (stigmasterol, acylated stigmasteryl glucoside, stigmasteryl glucoside, monogalactosyldiacylglycerol, digalactosyldiacylglycero... In the present paper the isolation and characterization of seven major glycolipid classes (stigmasterol, acylated stigmasteryl glucoside, stigmasteryl glucoside, monogalactosyldiacylglycerol, digalactosyldiacylglycerol, cerebroside and glucocerebroside) from Drymaria cordata (Linn.) Willd (Caryophyllaceae Family) are reported after an attempt has been made to congregate the traditional and pharmacological studies done on this important medicinal plant. Drymaria cordata is a weak spreading herb found widely dispersed in damp places all over the tropics of Africa, Asia and the Americas. There are many reports on its folk and traditional uses that include snake bite, skin diseases, peptic ulcer, headaches or nephritis, female infertility, sleeping disorders, convulsions, and febrile conditions in children. The plant has been examined on the basis of scientific in vitro and in vivo evaluations possessing the major pharmacological activities that include analgesic activity, antitussive activity, anxiolytic activity, antipyretic activity, antinociceptive activity, anti-inflammatory and antibacterial activities. The information summarized here is intended to serve as a reference tool for practitioners in the fields of ethnopharmacology, natural product chemistry and drug discovery related research. 展开更多
关键词 Drymaria cordata CARYOPHYLLACEAE Stigmasteryl GLUCOSIDE Glyceroglycolipid Sphingoglycolipid
暂未订购
The 10^(th)macrocylic arene supramolecular chemistry symposium
15
作者 Shuquan Zhang Meijin Lin +6 位作者 Andrew C.H.Sue Liping Cao Feng Wang Cheng Yang Tao Tu Feihe Huang Leyong Wang 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第12期1-3,共3页
In the last few decades,there has been a rapid emergence and growing interest in synthetic macrocyclic arenes,such as calixarenes[1,2],cyclophanes[3],cyclotriveratrylenes[4],pillararenes[5-7],and other novel macrocycl... In the last few decades,there has been a rapid emergence and growing interest in synthetic macrocyclic arenes,such as calixarenes[1,2],cyclophanes[3],cyclotriveratrylenes[4],pillararenes[5-7],and other novel macrocyclic arenes[8-10].These molecules have garnered significant attention in supramolecular chemistry for their fascinating structures,intrinsic cavities,ease of structural and property modifications and wide range of applications[11-14]. 展开更多
关键词 CHEMISTRY MACROCYCLIC PROPERTY
原文传递
Regulation of uniformity and electric field distribution achieved highly energy storage performance in PVDF-based nanocomposites via continuous gradient structure 被引量:1
16
作者 Jian Wang Baohui Wang +6 位作者 Pin Ma Yifei Zhang Honghong Gong Biyun Peng Sen Liang Yunchuan Xie Hailong Wang 《Chinese Chemical Letters》 2025年第4期542-548,共7页
PVDF-based nanocomposites have gained significant focus in capacitors for their excellent dielectric strength, its multi-scale structural inhomogeneity is the bottleneck for improving the energy storage performance. H... PVDF-based nanocomposites have gained significant focus in capacitors for their excellent dielectric strength, its multi-scale structural inhomogeneity is the bottleneck for improving the energy storage performance. Here, the composite components are optimized by the matrix modification,BST(Ba_(0.6)Sr_(0.4)TiO_(3)) ceramic fibrillation and surface coating. A series of PVDF/polymethyl methacrylate/lysozyme@BST nanofibers with continuous gradient distribution(PF-M/m BST nf-g) are prepared by the concentration gradient-biaxial high-speed electrospinning. The finite element simulation and experiment results indicate that the continuous gradient structure is favorable for the microstructure and inhomogeneity of the electric field distribution, significantly increasing the breakdown strength(Eb) and the permittivity(εr), as well as effectively suppressing the interfacial injected charge and leakage current. As a result, the energy storage density(Ue) of 23.1 J/cm^(3)at 600 MV/m with the charge-discharge efficiency(η) of 71% is achieved compared to PF-M(5.6 J/cm^(3)@350 MV/m, 65%). The exciting energy storage performance based on the well-designed PF-M/m BST nf-g provides important information for the development and application of polymer nanocomposite dielectrics. 展开更多
关键词 NANOCOMPOSITES NANOFIBERS PVDF-based polymers Breakdown strength Energy storage
原文传递
光催化H_(2)O_(2)生产的挑战与前景
17
作者 Mahmoud Sayed 李瀚 别传彪 《物理化学学报》 北大核心 2025年第9期37-43,共7页
过氧化氢(H_(2)O_(2))是100种最重要的化学品之一,广泛应用于漂白、消毒和合成化学等行业。最近,它被用作直接燃料电池的燃料。当前的H_(2)O_(2)生产依赖于苛刻的蒽醌氧化法。从环境、可持续性和经济角度来看,光催化H_(2)O_(2)生产是一... 过氧化氢(H_(2)O_(2))是100种最重要的化学品之一,广泛应用于漂白、消毒和合成化学等行业。最近,它被用作直接燃料电池的燃料。当前的H_(2)O_(2)生产依赖于苛刻的蒽醌氧化法。从环境、可持续性和经济角度来看,光催化H_(2)O_(2)生产是一种更有利的替代方法。该过程需要水和分子氧作为输入,并以阳光为唯一能源。尽管有这些优点,该技术的实际应用仍然具有挑战性。最常见的瓶颈是光催化剂的不足、上坡热力学、缓慢的过程动力学以及竞争性反应和逆向反应。本文讨论了这些局限性,并重点提出了提高效率和选择性的建议观点,旨在为大规模H_(2)O_(2)光生产铺平道路。 展开更多
关键词 热力学 动力学 逆反应 副反应 过氧化氢
在线阅读 下载PDF
Dissolving microneedle-assisted in situ cancer vaccine combined with cytolytic peptide for anti-melanoma immunotherapy 被引量:1
18
作者 Ying Sun Minglong Chen +7 位作者 Ying Chen Wanchen Zhao Yanping Fu Zhengwei Huang Chao Lu Chuanbin Wu Xin Pan Guilan Quan 《Chinese Chemical Letters》 2025年第12期318-324,共7页
Cancer vaccines are a notable area of immunotherapy due to their capacity to elicit specific antitumor immune responses and to create immune memory.However,they encounter challenges in clinical practice due to several... Cancer vaccines are a notable area of immunotherapy due to their capacity to elicit specific antitumor immune responses and to create immune memory.However,they encounter challenges in clinical practice due to several bottlenecks,including tumor heterogeneity,low immunogenicity,immunosuppressive tumor environment,and delivery obstacles,which collectively impact their clinical effectiveness.In this study,we developed nanocomposites containing positively charged melittin(MEL)and negatively charged photosensitizer indocyanine green(ICG),embedded in dissolving microneedles(MEL/ICG-HA@DMNs).This approach allows precise drug delivery by creating microchannels that bypass the stratum corneum barrier,targeting superficial lesions directly.Our results demonstrated that the complexation of MEL and ICG significantly reduced the hemolytic activity of MEL while maintaining its ability to disrupt cell membranes.After loading MEL/ICG-HA into the microneedle,MEL/ICG-HA@DMNs not only effectively concentrated the drug at the tumor site,inducing localized hyperthermia and successfully ablating the tumor,but also formed an in situ whole-cell vaccine containing a rich source of tumor-associated antigens.Moreover,the system promoted dendritic cell maturation and increased the M1/M2 macrophage ratio,enhancing the immune response.By overcoming the limitations of traditional cancer vaccines,this system ensures precise drug delivery and robust immune activation.This innovative approach holds the potential to revolutionize cancer treatment,offering a new paradigm in precision oncology. 展开更多
关键词 Photoimmunotherapy Dissolving microneedle MELITTIN In situ cancer vaccine IMMUNOMODULATION
原文传递
Quantitative analysis of the ohmic resistance in aqueous organic redox flow batteries
19
作者 Kang Peng Junkai Fang +3 位作者 Siyu Chen Peipei Zuo Tongwen Xu Zhengjin Yang 《中国科学技术大学学报》 北大核心 2025年第6期22-26,21,I0001,共7页
Aqueous organic redox flow batteries(AORFBs)exploit the reversible electrochemical reactions of watersoluble organic redox-active species to store electricity and have emerged as promising electrochemical energy stora... Aqueous organic redox flow batteries(AORFBs)exploit the reversible electrochemical reactions of watersoluble organic redox-active species to store electricity and have emerged as promising electrochemical energy storage technologies.To improve the battery performance related to the cell resistance,such as the power density and energy efficiency,it is essential to understand the cell resistance and determine the major contributor.Here,we conduct comprehensive electrochemical impedance spectroscopy(EIS)studies and cell polarization on a representative TEMPTMA/MV cell assembled with a commercial AMVN membrane and probe the proportion of the ohmic resistance to the total cell resistance at various stages of charge(SOCs)ranging from 10%to 100%.At 0 mA·cm^(−2),the ohmic resistance is responsible for 60.3%–71.7%of the resistance of the entire cell,whereas at high current densities(for example,when the power density reaches the maximum),the ohmic resistance still contributes 47.9%–61.4%.Our quantitative analysis highlights the dominance of the ohmic resistance and anticipates that a membrane with lower resistivity may significantly increase the power density. 展开更多
关键词 aqueous organic redox flow battery ohmic resistance electrochemical impedance spectroscopy cell polarization power density
在线阅读 下载PDF
Ultrafine platinum clusters achieved by metal‑organic framework derived cobalt nanoparticle/porous carbon:Remarkable catalytic performance in dehydrogenation of ammonia borane
20
作者 XIE Xinnan ZHANG Boyu +4 位作者 YANG Jianxun ZHONG Yi Osama Younis YANG Jianxiao YANG Xinchun 《无机化学学报》 北大核心 2025年第10期2095-2102,共8页
Ultrafine,highly dispersed Pt clusters were immobilized onto the Co nanoparticle surfaces by one-step pyrolysis of the precursor Pt(Ⅱ)-encapsulating Co-MOF-74.Owing to the small size effects of Pt clusters as well as... Ultrafine,highly dispersed Pt clusters were immobilized onto the Co nanoparticle surfaces by one-step pyrolysis of the precursor Pt(Ⅱ)-encapsulating Co-MOF-74.Owing to the small size effects of Pt clusters as well as the strongly enhanced synergistic interactions between Pt and Co atoms,the obtained Pt-on-Co/C400 catalysts exhib-ited excellent catalytic activity toward the hydrolysis of ammonia borane with an extremely high turnover frequency(TOF)value of 3022 min^(-1)at 303 K.Durability test indicated that the obtained Pt-on-Co/C400 catalysts possessed high catalytic stability,and there were no changes in the catalyst structures and catalytic activities after 10 cycles. 展开更多
关键词 ammonia borane hydrogen generation Pt cluster porous carbon metal-organic framework
在线阅读 下载PDF
上一页 1 2 105 下一页 到第
使用帮助 返回顶部