High-pressure research has emerged as a pivotal approach for advancing our understanding and development of optoelectronic materials,which are vital for a wide range of applications,including photovoltaics,light-emitt...High-pressure research has emerged as a pivotal approach for advancing our understanding and development of optoelectronic materials,which are vital for a wide range of applications,including photovoltaics,light-emitting devices,and photodetectors.This review highlights various in situ characterization methods employed in high-pressure research to investigate the optical,electronic,and structural properties of optoelectronic materials.We explore the advances that have been made in techniques such as X-ray diffraction,absorption spectroscopy,nonlinear optics,photoluminescence spectroscopy,Raman spectroscopy,and photoresponse measurement,emphasizing how these methods have enhanced the elucidation of structural transitions,bandgap modulation,performance optimization,and carrier dynamics engineering.These insights underscore the pivotal role of high-pressure techniques in optimizing and tailoring optoelectronic materials for future applications.展开更多
Sea buckthorn(Hippophae rhamnoides L.)is a natural homologous substance of medicine and food.Polysaccharide,as one of its primary active components,has very superior biological activity and can be used as a dietary su...Sea buckthorn(Hippophae rhamnoides L.)is a natural homologous substance of medicine and food.Polysaccharide,as one of its primary active components,has very superior biological activity and can be used as a dietary supplement for functional foods,with good commercial prospects.Although initial progress has been made in the study of sea buckthorn polysaccharides,related studies have been fragmented and lacked systematic and generalization.This manuscript presents a critical analysis and systematic summary of the extraction and purification methods,structural characterization and physicochemical properties,biological activity and potential mechanisms,and structure-activity relationships of sea buckthorn polysaccharides.Accumulating evidence has indicated that sea buckthorn polysaccharides,which were widely prepared by water extraction and column chromatography purifications,exhibited exhibit superior biological activities in vitro and in vivo,including antioxidant,immunomodulatory,anti-inflammatory,hepatorenal protective,antibacterial,antiviral,and prebiotic activities.After analysis,it was concluded that there is a correlation between the relevant activities of sea buckthorn polysaccharides and that the structure of sea buckthorn polysaccharides has a great influence on their biological activity.We reviewed the challenges and limitations of sea buckthorn polysaccharides,summarized the critical aspects,and provided suggestions for potential breakthroughs in the research and application of sea buckthorn polysaccharide.展开更多
The reliable estimation of the wavenumber space(k-space)of the plates remains a longterm concern for acoustic modeling and structural dynamic behavior characterization.Most current analyses of wavenumber identificatio...The reliable estimation of the wavenumber space(k-space)of the plates remains a longterm concern for acoustic modeling and structural dynamic behavior characterization.Most current analyses of wavenumber identification methods are based on the deterministic hypothesis.To this end,an inverse method is proposed for identifying wave propagation characteristics of twodimensional structures under stochastic conditions,such as wavenumber space,dispersion curves,and band gaps.The proposed method is developed based on an algebraic identification scheme in the polar coordinate system framework,thus named Algebraic K-Space Identification(AKSI)technique.Additionally,a model order estimation strategy and a wavenumber filter are proposed to ensure that AKSI is successfully applied.The main benefit of AKSI is that it is a reliable and fast method under four stochastic conditions:(A)High level of signal noise;(B)Small perturbation caused by uncertainties in measurement points’coordinates;(C)Non-periodic sampling;(D)Unknown structural periodicity.To validate the proposed method,we numerically benchmark AKSI and three other inverse methods to extract dispersion curves on three plates under stochastic conditions.One experiment is then performed on an isotropic steel plate.These investigations demonstrate that AKSI is a good in-situ k-space estimator under stochastic conditions.展开更多
Correction:Natural Products and Bioprospecting(2024)14:33 https://doi.org/10.1007/s13659-024-00455-x Following publication of the original article[1],the authors reported that the original version of this article unfo...Correction:Natural Products and Bioprospecting(2024)14:33 https://doi.org/10.1007/s13659-024-00455-x Following publication of the original article[1],the authors reported that the original version of this article unfortunately contained mistakes.Page 1,section“Abstract”,the originally published texts were:Despite low bioavailability(0.024%),N-hydap exhibited a higher distribution in the lungs(26.26%),accounting for its efficacy against SCLC.展开更多
This paper introduces a model for characterizing the contact behavior of irregular asperities,transforming it into a superposition of sinusoidal asperity contact behaviors.A new sinusoidal asperity model is developed ...This paper introduces a model for characterizing the contact behavior of irregular asperities,transforming it into a superposition of sinusoidal asperity contact behaviors.A new sinusoidal asperity model is developed for bilin-ear hardening under plane strain conditions.Empirical equations are proposed,considering geometric shapes,tangent modulus,and Young’s modulus.The frequency of asperity height is extracted through Fourier transform for irregular asperities.Contact area and pressure are predicted using the sinusoidal asperity model,and the behavior of irregular asperities is obtained by superimposing those with the first three frequencies.Experimen-tal validation is conducted with milling and knurling-formed asperities,showing good alignment between the model and experimental results.In rough surface models,the proposed irregular asperity model exhibits greater accuracy in predicting contact behavior than a single sinusoidal asperity when interference exceeds 10%of the amplitude.展开更多
Three different preparation methods including steam physical activation, catalytic carbonation and KOH chemical activation methods were used to prepare municipal solid waste- based carbon materials. The methylene blue...Three different preparation methods including steam physical activation, catalytic carbonation and KOH chemical activation methods were used to prepare municipal solid waste- based carbon materials. The methylene blue （MB） adsorption value was applied to evaluate the adsorption capabilities of the prepared carbon materials. The effects of preparation methods on adsorption capability and yield of products were investigated. The yield of carbon materials with the catalytic carbonation method is the highest, and the KOH activation method is the second level. Considering the adsorption performance, the KOH activation method is much more favorable. Among the different components of municipal solid waste-based carbon materials, the adsorption properties of the single component of paperboard, the double components of tire and paperboard, the triple components of tire, paperboard and polyvinyl chloride （PVC）, and the multi-component mixtures are better than those of other single-, double-, triple- and multi-component mixtures, respectively.展开更多
The preparation of Nd(OH)3 powder by the direct hydration method using Nd2O3 as a raw material was studied,and the effects of stirring mode,H2O and Nd2O3 molar ratio,stirring rate,and reaction time on temperature chan...The preparation of Nd(OH)3 powder by the direct hydration method using Nd2O3 as a raw material was studied,and the effects of stirring mode,H2O and Nd2O3 molar ratio,stirring rate,and reaction time on temperature change and conversion rate in a hydration system were analyzed.The reasonable process conditions for the direct hydration of Nd(OH)3 by Nd2O3 were then determined.Process,morphology,and structure were considered in the preparation of neodymium hydroxide powder,and its composition was investigated by X-ray powder diffraction,scanning electron microscopy,laser particle size analysis,thermogravimetric differential thermal analysis,and chemical analysis.It has been proved that the process is simple and feasible,in line with the concept of modern green chemistry,and the products also meet the market requirements.展开更多
A kind of thermosetting asphalt binder designated as epoxy asphalt, which is composed of two components： maleated asphalt with curing agents and accelerant of epoxy resin and epoxy resin, was prepared. Its paving fea...A kind of thermosetting asphalt binder designated as epoxy asphalt, which is composed of two components： maleated asphalt with curing agents and accelerant of epoxy resin and epoxy resin, was prepared. Its paving feasibility and concrete performances were investigated using Brookfield viscosimeter, direct tensile test （DTT）, Marshall testing and the MTS 810 hydraulic servos-system, respectively. Although only 50% to 60% of added maleic anhydride （MAH） reacted with the base asphalt irreversibly （probably by Diels-Alder mechanism）, the curing rate, rupture elongation and tensile strength of maleated epoxy asphalt were enhanced more evidently than those of unmaleated epoxy asphalt. As a result, an epoxy asphalt made from 4% MAH modified asphalt and other curing agents was featured to have an average rupture elongation of 281.9%, an average tensile strength of 2. 63 MPa, and the Marshall stability of its cured concrete reached 37. 0 kN, while that of uncured concrete was 10. 2 kN and the combined beam of fatigue test was still found to behave well after 12 × 10^6 cycles load.展开更多
The novel nickel-based catalysts with a nickel content of 12 wt% were prepared with the zirconia-alumina composite as the supports. The new carriers, ZrO2 improved alumina, were synthesized by three methods, i.e., imp...The novel nickel-based catalysts with a nickel content of 12 wt% were prepared with the zirconia-alumina composite as the supports. The new carriers, ZrO2 improved alumina, were synthesized by three methods, i.e., impregnation-precipitation, co-precipitation, and impregnation method. The catalytic properties of these catalysts were investigated in the methanation of carbon dioxide, and the samples were characterized by X-ray diffraction （XRD）, X-ray photoelectron spectroscope （XPS）, temperature-programmed reduction （TPR） and temperature-programmed desorption （TPD） techniques. The new catalysts showed higher catalytic activity and better stability than Ni/γ-Al2O3. Furthermore, as a support for new nickel catalyst, the ZrO2-Al2O3 composite prepared by the impregnation-precipitation method was more efficient than the other supports in the methanation of carbon dioxide. The highly dispersed zirconium oxide on the surface of γ-Al2O3 inhibited the formation of nickel aluminate-like phase, which was responsible for the better dispersion of Ni species and easier reduction of NiO species, leading to the enhanced catalytic performance of corresponding catalyst.展开更多
A different method was employed for the preparation of a metal supported perovskite catalyst for the catalytic combustion of methane.The prepared metallic catalysts were characterized by means of X-ray diffractometer(...A different method was employed for the preparation of a metal supported perovskite catalyst for the catalytic combustion of methane.The prepared metallic catalysts were characterized by means of X-ray diffractometer(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and also by ultrasonic and thermal shock tests and catalytic activity.It was found that the process factors during the preparation,e.g.the preparation of the catalyst precursor and the coating slurry,the calcination te...展开更多
Bi 2O 3 nanoparticles were prepared by means of ammonia precipitation, polyol mediated methods and microemulsion chemical method. The structure and properties of the as-prepared nanoparticles, having been submitted to...Bi 2O 3 nanoparticles were prepared by means of ammonia precipitation, polyol mediated methods and microemulsion chemical method. The structure and properties of the as-prepared nanoparticles, having been submitted to a heat-treatment test at 750 ℃, were characterized by means of XRD, BET, XPS and UV-Vis absorption techniques. The photocatalytic oxidation reactions of benzene, toluene and xylene were used as the model reaction to measure the photocatalytic activity of Bi 2O 3 nanoparticles, respectively. The results show that the crystallite size of Bi 2O 3 prepared with different methods and calcined at 750 ℃ were 50.6, 38.5 and 31.5 nm, respectively. The photocatalytic activity of Bi 2O 3 nanoparticles prepared with the microemulsion chemical method was higher than that of the particles prepared with the polyol mediated method; and that of the particles prepared with the micromulsion chemical method was the highest among the three. The degradation rates of the three pollutants xylene, toluene and benzene decreased in sequence.展开更多
Supported and colloidal single‐atom catalysts(SACs),which possess excellent catalytic properties,are particularly important in both fundamental studies and practical applications.The progress made in the preparation ...Supported and colloidal single‐atom catalysts(SACs),which possess excellent catalytic properties,are particularly important in both fundamental studies and practical applications.The progress made in the preparation methods,characterization,catalytic performances and mechanisms of SACs anchored to metal oxides,two‐dimensional materials and the surface of metal nanoclusters(NCs)are reviewed.The different techniques for SAC fabrication,including conventional solution methods based on co‐precipitation,incipient wetness co‐impregnation,and the chemical vapor deposition method,as well as the newer atom layer deposition(ALD)and galvanic replacement methods,are summarized.The main results from experimental and theoretical studies of various catalytic reactions over SACs,including oxidation reactions,hydrogenation,water gas shift,photocatalytic H2evolution and electrochemical reactions,are also discussed.Moreover,the electronic properties of the single atoms and their interactions with the supports are described to assist in understanding the origin of the high catalytic activity and selectivity of SACs.Finally,possible future research directions of SACs and their applications are proposed.展开更多
Influence of three different preparation methods, i.e. impregnation, coprecipitation, and inverse coprecipitation, on the preferential oxidation of CO in excess hydrogen （PROX） over CuO-CeO2 catalysts has been inves...Influence of three different preparation methods, i.e. impregnation, coprecipitation, and inverse coprecipitation, on the preferential oxidation of CO in excess hydrogen （PROX） over CuO-CeO2 catalysts has been investigated and CuO-CeO2 catalysts are characterized using BET, XPS, XRD, UV Raman, and TPR techniques. The results show that the catalysts prepared by coprecipitation have smaller particle sizes, well-dispersed CuOx species, more oxygen vacancies, and are more active in the PROX than those prepared by the other methods. However. the inverse coprecipitation depresses the catalytic performance of CuO-CeO2 catalysts and causes the growth of CuO-CeO2 because of different pH value in the precipitation process.展开更多
This work examines the influence of preparation methods on the physicochemical properties and catalytic performance of MnOx‐CeO2 catalysts for selective catalytic reduction of NO by NH3 (NH3‐SCR) at low temperature....This work examines the influence of preparation methods on the physicochemical properties and catalytic performance of MnOx‐CeO2 catalysts for selective catalytic reduction of NO by NH3 (NH3‐SCR) at low temperature. Five different methods, namely, mechanical mixing, impregnation,hydrothermal treatment, co‐precipitation, and a sol‐gel technique, were used to synthesizeMnOx‐CeO2 catalysts. The catalysts were characterized in detail, and an NH3‐SCR model reaction waschosen to evaluate the catalytic performance. The results showed that the preparation methodsaffected the catalytic performance in the order: hydrothermal treatment > sol‐gel > co‐precipitation> impregnation > mechanical mixing. This order correlated with the surface Ce3+ and Mn4+ content,oxygen vacancies and surface adsorbed oxygen species concentration, and the amount of acidic sitesand acidic strength. This trend is related to redox interactions between MnOx and CeO2. The catalystformed by a hydrothermal treatment exhibited excellent physicochemical properties, optimal catalyticperformance, and good H2O resistance in NH3‐SCR reaction. This was attributed to incorporationof Mnn+ into the CeO2 lattice to form a uniform ceria‐based solid solution (containing Mn‐O‐Cestructures). Strengthening of the electronic interactions between MnOx and CeO2, driven by thehigh‐temperature and high‐pressure conditions during the hydrothermal treatment also improved the catalyst characteristics. Thus, the hydrothermal treatment method is an efficient and environment‐friendly route to synthesizing low‐temperature denitrification (deNOx) catalysts.展开更多
NaY Zeolite was synthesized in a rotating packed bed （RPB） for the first time. A Si-A1 gel with a specific composition was used as the structure-directing agent. The as-synthesized NaY Zeolite was characterized with...NaY Zeolite was synthesized in a rotating packed bed （RPB） for the first time. A Si-A1 gel with a specific composition was used as the structure-directing agent. The as-synthesized NaY Zeolite was characterized with scanning electron microscopy （SEM）, X-ray diffraction （XRD） and specific surface area （BET）. The characterization result showed that the NaY Zeolite had a particle size of approximately 200 rim, n（SiO2）/n（Al203） ratio of 5.03, crystallinity of 96% and specific surface area of 714 m2/g. The experimental results indicated that the structure of NaY Zeolite was related to the synthesis conditions （such as reactors, crystallization time and so on）. The micromixing efficiency was proven to be the most important factor for synthesis of NaY Zeolite in the high-gravity environment in RPB.展开更多
Collagen materials were crosslinked by 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) in the presence of chondroitin sulfate (CS), one of glycosaminoglycans (GAGS). PVA and chitosan were also blended with colla...Collagen materials were crosslinked by 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) in the presence of chondroitin sulfate (CS), one of glycosaminoglycans (GAGS). PVA and chitosan were also blended with collagen. The physical and chemical properties of the matrices were characterized by SEM, DSC, and ESCA. L929 cells were implanted on the matrices to show the cytotoxic and the biological characters of the materials. The results indicate that EDC is an effective and non-cytotoxic cross-link reagent, which can replace the common dialdehyde reagent. The attachment of CS can improve the stability of collagen and accelerate cell growth. The addition of PVA can prepare porous matrices with smaller bore size. There are reactions between the chitosan and collagen, and the composite has good biological character. The presence of chitosan can also increase the amount of incorporated CS.展开更多
Marine algae are valuable sources of health-promoting molecules that have been consumed by Asians for decades.Among aquatic flora,marine algae stand out in terms of high content of marine algae polysaccharides(MAP)suc...Marine algae are valuable sources of health-promoting molecules that have been consumed by Asians for decades.Among aquatic flora,marine algae stand out in terms of high content of marine algae polysaccharides(MAP)such as carrageenan,alginate,fucoidan,laminaran,agarose,rhamnan,and ulvan.When hydrolyzed,MAP generate marine algae oligosaccharides(MAO),which have attracted interest in recent years due to their superior solubility compared with MAP.Besides,MAO have been demonstrated numerous biological activities including antioxidant,antidiabetic,anti-inflammatory,antimicrobial,and prebiotic activities.Thus,this review summarizes the main chemical classes of MAO,their sources,and the main processes used for their production(i.e.,physical,chemical,and biological methods),coupled with a discussion of the advantages and disadvantages of these methods.Highlights of the biological activities of MAO and their potential applications in food,nutraceutical,and pharmaceuticals would also be discussed and summarized.展开更多
The thermally expandable microspheres（TEMs） were prepared via suspension polymerization with acrylonitrile（AN）, methyl methacrylate（MMA） and methyl acrylate（MA） as monomers and n-hexane as the blowing agent. M...The thermally expandable microspheres（TEMs） were prepared via suspension polymerization with acrylonitrile（AN）, methyl methacrylate（MMA） and methyl acrylate（MA） as monomers and n-hexane as the blowing agent. Meanwhile, a novel type of functional and conductive thermal expandable microsphere was obtained through strongly covering the surface of microsphere by conductive polymers with the mass loading of 1.5%. The optimal conditions to prepare high foaming ratio and equally distributed microcapsules were investigated with AN-MMA-MA in the proportion of 70%/20%/10%（m/m/m）, and 25 wt% of n-hexane in oil phase. The further investigation results showed that the unexpanded TEMs were about 30 μm in diameter and the maximum expansion ratio was nearly 125 times of original volume. The polypyrrole（PPy） was smoothly coated on the surface of the TEMs and the expansion property of PPy-coated TEMs was almost the same as the uncoated TEMs. Moreover, the structure and expanding performance of TEMs and PPy-coated TEMs were characterized by scanning electron microscopy（SEM）, laser particle size analyzer and dilatometer（DIL）.展开更多
Three co-impregnation/chemical reduction methods in acidic solutions of pH 〈 1,including ethylene glycol （EG）,NaBH4,and HCOOH,were compared for Pt-WO3/C catalysts.Pt-WO3/C catalysts containing 10 wt.% and 20 wt.% p...Three co-impregnation/chemical reduction methods in acidic solutions of pH 〈 1,including ethylene glycol （EG）,NaBH4,and HCOOH,were compared for Pt-WO3/C catalysts.Pt-WO3/C catalysts containing 10 wt.% and 20 wt.% platinum per carbon were prepared by the three methods; their morphology and electrocatalytic activities were characterized.The 20 wt.% Pt-WO3/C catalyst prepared by the co-impregnation/EG method presented the optimal dispersion with an average particle size of 4.6 nm and subsequently the best electrocatalytic activity,and so,it was further characterized.Its anodic peak current density for ethanol oxidation from linear sweep voltammetry （LSV） is 7.9 mA·cm^-2,which is 1.4 and 5.2 times as high as those of the catalysts prepared by co-impregnation/NaBH4 and co-impregnation/ HCOOH reduction methods,2.1 times as high as that of the 10 wt.% Pt-WO3/C catalyst prepared by co-impregnation/EG method,respectively.展开更多
To relieve dust pollution in open cut coal mines and reduce the hazards of coal dust pollution to the environment and workers we optimized the synthesis of a dust suppressant by graft copolymerization of environmental...To relieve dust pollution in open cut coal mines and reduce the hazards of coal dust pollution to the environment and workers we optimized the synthesis of a dust suppressant by graft copolymerization of environmentally friendly soy protein isolate with methyl methacrylate.This dust suppressant could effectively control dust pollution in open cut coal mines. The optimized conditions for graft copolymerization in this case were determined by a response surface experiment designed with Design-Expert 10 software. Characterization by scanning electron microscopy showed a significant morphology change of the dust suppressant and the generation of a rigid and dense layer on its surface after interacting with coal dust.The layer exhibited good bonding and dust suppression performance. The analysis with Fourier-transform infrared spectroscopy revealed the appearance of new absorption peaks near 1300, 1072, and 1631 cm, demonstrating effective graft copolymerization. The proposed dust suppressant exhibited excellent wind erosion resistance, with a resistance that exceeded 90% at a wind speed of 6.5 m/sec. The successful graft copolymerization and effective bonding and curing of the dust suppressant on coal dust were experimentally verified.This is of great significance to the control of coal dust pollution.展开更多
基金supported by the National Nature Science Foundation of China(NSFC)(Grant Nos.22275004,62274040,and 62304046)the Shanghai Science and Technology Committee(Grant No.22JC1410300)+2 种基金the Shanghai Key Laboratory of Novel Extreme Condition Materials(Grant No.22dz2260800)the National Key Research and Development Program of China(Grant No.2022YFE0137400)the Shanghai Science and Technology Innovationaction Plan(Grant No.24DZ3001200).
文摘High-pressure research has emerged as a pivotal approach for advancing our understanding and development of optoelectronic materials,which are vital for a wide range of applications,including photovoltaics,light-emitting devices,and photodetectors.This review highlights various in situ characterization methods employed in high-pressure research to investigate the optical,electronic,and structural properties of optoelectronic materials.We explore the advances that have been made in techniques such as X-ray diffraction,absorption spectroscopy,nonlinear optics,photoluminescence spectroscopy,Raman spectroscopy,and photoresponse measurement,emphasizing how these methods have enhanced the elucidation of structural transitions,bandgap modulation,performance optimization,and carrier dynamics engineering.These insights underscore the pivotal role of high-pressure techniques in optimizing and tailoring optoelectronic materials for future applications.
基金supported by the National Natural Science Foundation of China(32201994)。
文摘Sea buckthorn(Hippophae rhamnoides L.)is a natural homologous substance of medicine and food.Polysaccharide,as one of its primary active components,has very superior biological activity and can be used as a dietary supplement for functional foods,with good commercial prospects.Although initial progress has been made in the study of sea buckthorn polysaccharides,related studies have been fragmented and lacked systematic and generalization.This manuscript presents a critical analysis and systematic summary of the extraction and purification methods,structural characterization and physicochemical properties,biological activity and potential mechanisms,and structure-activity relationships of sea buckthorn polysaccharides.Accumulating evidence has indicated that sea buckthorn polysaccharides,which were widely prepared by water extraction and column chromatography purifications,exhibited exhibit superior biological activities in vitro and in vivo,including antioxidant,immunomodulatory,anti-inflammatory,hepatorenal protective,antibacterial,antiviral,and prebiotic activities.After analysis,it was concluded that there is a correlation between the relevant activities of sea buckthorn polysaccharides and that the structure of sea buckthorn polysaccharides has a great influence on their biological activity.We reviewed the challenges and limitations of sea buckthorn polysaccharides,summarized the critical aspects,and provided suggestions for potential breakthroughs in the research and application of sea buckthorn polysaccharide.
基金supported by the Lyon Acoustics Center of Lyon University,Francefunded by the China Scholarship Council(CSC)。
文摘The reliable estimation of the wavenumber space(k-space)of the plates remains a longterm concern for acoustic modeling and structural dynamic behavior characterization.Most current analyses of wavenumber identification methods are based on the deterministic hypothesis.To this end,an inverse method is proposed for identifying wave propagation characteristics of twodimensional structures under stochastic conditions,such as wavenumber space,dispersion curves,and band gaps.The proposed method is developed based on an algebraic identification scheme in the polar coordinate system framework,thus named Algebraic K-Space Identification(AKSI)technique.Additionally,a model order estimation strategy and a wavenumber filter are proposed to ensure that AKSI is successfully applied.The main benefit of AKSI is that it is a reliable and fast method under four stochastic conditions:(A)High level of signal noise;(B)Small perturbation caused by uncertainties in measurement points’coordinates;(C)Non-periodic sampling;(D)Unknown structural periodicity.To validate the proposed method,we numerically benchmark AKSI and three other inverse methods to extract dispersion curves on three plates under stochastic conditions.One experiment is then performed on an isotropic steel plate.These investigations demonstrate that AKSI is a good in-situ k-space estimator under stochastic conditions.
文摘Correction:Natural Products and Bioprospecting(2024)14:33 https://doi.org/10.1007/s13659-024-00455-x Following publication of the original article[1],the authors reported that the original version of this article unfortunately contained mistakes.Page 1,section“Abstract”,the originally published texts were:Despite low bioavailability(0.024%),N-hydap exhibited a higher distribution in the lungs(26.26%),accounting for its efficacy against SCLC.
基金supported by the National Natural Science Foundation of China(Grant Nos.12272227 and 11732009).
文摘This paper introduces a model for characterizing the contact behavior of irregular asperities,transforming it into a superposition of sinusoidal asperity contact behaviors.A new sinusoidal asperity model is developed for bilin-ear hardening under plane strain conditions.Empirical equations are proposed,considering geometric shapes,tangent modulus,and Young’s modulus.The frequency of asperity height is extracted through Fourier transform for irregular asperities.Contact area and pressure are predicted using the sinusoidal asperity model,and the behavior of irregular asperities is obtained by superimposing those with the first three frequencies.Experimen-tal validation is conducted with milling and knurling-formed asperities,showing good alignment between the model and experimental results.In rough surface models,the proposed irregular asperity model exhibits greater accuracy in predicting contact behavior than a single sinusoidal asperity when interference exceeds 10%of the amplitude.
基金The National Natural Science Foundation of China(No.51576048)the Environmental Protection Subject Foundation of Jiangsu Province(No.2015013)+3 种基金the Industry,Education and Research Prospective Project of Jiangsu Province(No.BY2015060-04)the Fok Ying Tong Education Foundation(No.142026)the Fundamental Research Funds for the Central UniversitiesProgram for New Century Excellent Talents in University(No.NCET-12-0118)
文摘Three different preparation methods including steam physical activation, catalytic carbonation and KOH chemical activation methods were used to prepare municipal solid waste- based carbon materials. The methylene blue （MB） adsorption value was applied to evaluate the adsorption capabilities of the prepared carbon materials. The effects of preparation methods on adsorption capability and yield of products were investigated. The yield of carbon materials with the catalytic carbonation method is the highest, and the KOH activation method is the second level. Considering the adsorption performance, the KOH activation method is much more favorable. Among the different components of municipal solid waste-based carbon materials, the adsorption properties of the single component of paperboard, the double components of tire and paperboard, the triple components of tire, paperboard and polyvinyl chloride （PVC）, and the multi-component mixtures are better than those of other single-, double-, triple- and multi-component mixtures, respectively.
基金financial support for this study by the Natural Science Foundation of Inner Mongolia(CN)(2016ZD05)。
文摘The preparation of Nd(OH)3 powder by the direct hydration method using Nd2O3 as a raw material was studied,and the effects of stirring mode,H2O and Nd2O3 molar ratio,stirring rate,and reaction time on temperature change and conversion rate in a hydration system were analyzed.The reasonable process conditions for the direct hydration of Nd(OH)3 by Nd2O3 were then determined.Process,morphology,and structure were considered in the preparation of neodymium hydroxide powder,and its composition was investigated by X-ray powder diffraction,scanning electron microscopy,laser particle size analysis,thermogravimetric differential thermal analysis,and chemical analysis.It has been proved that the process is simple and feasible,in line with the concept of modern green chemistry,and the products also meet the market requirements.
文摘A kind of thermosetting asphalt binder designated as epoxy asphalt, which is composed of two components： maleated asphalt with curing agents and accelerant of epoxy resin and epoxy resin, was prepared. Its paving feasibility and concrete performances were investigated using Brookfield viscosimeter, direct tensile test （DTT）, Marshall testing and the MTS 810 hydraulic servos-system, respectively. Although only 50% to 60% of added maleic anhydride （MAH） reacted with the base asphalt irreversibly （probably by Diels-Alder mechanism）, the curing rate, rupture elongation and tensile strength of maleated epoxy asphalt were enhanced more evidently than those of unmaleated epoxy asphalt. As a result, an epoxy asphalt made from 4% MAH modified asphalt and other curing agents was featured to have an average rupture elongation of 281.9%, an average tensile strength of 2. 63 MPa, and the Marshall stability of its cured concrete reached 37. 0 kN, while that of uncured concrete was 10. 2 kN and the combined beam of fatigue test was still found to behave well after 12 × 10^6 cycles load.
基金supported by the Southwest Research & Design Institute of Chemical Industy (SKLIV GR-22010-01)the National Basic Research Program of China (973 Program, 2011CB201202) of Ministry of Science and Technology
文摘The novel nickel-based catalysts with a nickel content of 12 wt% were prepared with the zirconia-alumina composite as the supports. The new carriers, ZrO2 improved alumina, were synthesized by three methods, i.e., impregnation-precipitation, co-precipitation, and impregnation method. The catalytic properties of these catalysts were investigated in the methanation of carbon dioxide, and the samples were characterized by X-ray diffraction （XRD）, X-ray photoelectron spectroscope （XPS）, temperature-programmed reduction （TPR） and temperature-programmed desorption （TPD） techniques. The new catalysts showed higher catalytic activity and better stability than Ni/γ-Al2O3. Furthermore, as a support for new nickel catalyst, the ZrO2-Al2O3 composite prepared by the impregnation-precipitation method was more efficient than the other supports in the methanation of carbon dioxide. The highly dispersed zirconium oxide on the surface of γ-Al2O3 inhibited the formation of nickel aluminate-like phase, which was responsible for the better dispersion of Ni species and easier reduction of NiO species, leading to the enhanced catalytic performance of corresponding catalyst.
基金supported by the Ministry of Science and Technology of Beijing (20081D0500500142)
文摘A different method was employed for the preparation of a metal supported perovskite catalyst for the catalytic combustion of methane.The prepared metallic catalysts were characterized by means of X-ray diffractometer(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and also by ultrasonic and thermal shock tests and catalytic activity.It was found that the process factors during the preparation,e.g.the preparation of the catalyst precursor and the coating slurry,the calcination te...
基金the National Natural Science Foundation of China(No.2 0 2 770 15 )
文摘Bi 2O 3 nanoparticles were prepared by means of ammonia precipitation, polyol mediated methods and microemulsion chemical method. The structure and properties of the as-prepared nanoparticles, having been submitted to a heat-treatment test at 750 ℃, were characterized by means of XRD, BET, XPS and UV-Vis absorption techniques. The photocatalytic oxidation reactions of benzene, toluene and xylene were used as the model reaction to measure the photocatalytic activity of Bi 2O 3 nanoparticles, respectively. The results show that the crystallite size of Bi 2O 3 prepared with different methods and calcined at 750 ℃ were 50.6, 38.5 and 31.5 nm, respectively. The photocatalytic activity of Bi 2O 3 nanoparticles prepared with the microemulsion chemical method was higher than that of the particles prepared with the polyol mediated method; and that of the particles prepared with the micromulsion chemical method was the highest among the three. The degradation rates of the three pollutants xylene, toluene and benzene decreased in sequence.
基金supported by the National Natural Science Foundation of China(51472184 and 51472185)the Science and Technology Support Program of Hubei Province(2013BHE003)the Program for Innovative Teams of Outstanding Young and Middle-Aged Researchers in the Higher Education Institutions of Hubei Province(T201602)~~
文摘Supported and colloidal single‐atom catalysts(SACs),which possess excellent catalytic properties,are particularly important in both fundamental studies and practical applications.The progress made in the preparation methods,characterization,catalytic performances and mechanisms of SACs anchored to metal oxides,two‐dimensional materials and the surface of metal nanoclusters(NCs)are reviewed.The different techniques for SAC fabrication,including conventional solution methods based on co‐precipitation,incipient wetness co‐impregnation,and the chemical vapor deposition method,as well as the newer atom layer deposition(ALD)and galvanic replacement methods,are summarized.The main results from experimental and theoretical studies of various catalytic reactions over SACs,including oxidation reactions,hydrogenation,water gas shift,photocatalytic H2evolution and electrochemical reactions,are also discussed.Moreover,the electronic properties of the single atoms and their interactions with the supports are described to assist in understanding the origin of the high catalytic activity and selectivity of SACs.Finally,possible future research directions of SACs and their applications are proposed.
文摘Influence of three different preparation methods, i.e. impregnation, coprecipitation, and inverse coprecipitation, on the preferential oxidation of CO in excess hydrogen （PROX） over CuO-CeO2 catalysts has been investigated and CuO-CeO2 catalysts are characterized using BET, XPS, XRD, UV Raman, and TPR techniques. The results show that the catalysts prepared by coprecipitation have smaller particle sizes, well-dispersed CuOx species, more oxygen vacancies, and are more active in the PROX than those prepared by the other methods. However. the inverse coprecipitation depresses the catalytic performance of CuO-CeO2 catalysts and causes the growth of CuO-CeO2 because of different pH value in the precipitation process.
基金supported by the National Natural Science Foundation of China (No. 21507130)the Open Project Program of Beijing National Laboratory for Molecular Sciences (No. 20140142)+3 种基金the Open Project Program of Chongqing Key Laboratory of Environmental Materials and Remediation Technology from Chongqing University of Arts and Sciences (No. CEK1405)the Open Project Program of Jiangsu Key Laboratory of Vehicle Emissions Control (No. OVEC001)the Open Project Program of Chongqing Key Laboratory of Catalysis and Functional Organic Molecules from Chongqing Technology and Business University (1456029)the Chongqing Science & Technology Commission (Nos. cstc2016jcyj A0070, cstc2014pt-gc20002, cstckjcxljrc13)~~
文摘This work examines the influence of preparation methods on the physicochemical properties and catalytic performance of MnOx‐CeO2 catalysts for selective catalytic reduction of NO by NH3 (NH3‐SCR) at low temperature. Five different methods, namely, mechanical mixing, impregnation,hydrothermal treatment, co‐precipitation, and a sol‐gel technique, were used to synthesizeMnOx‐CeO2 catalysts. The catalysts were characterized in detail, and an NH3‐SCR model reaction waschosen to evaluate the catalytic performance. The results showed that the preparation methodsaffected the catalytic performance in the order: hydrothermal treatment > sol‐gel > co‐precipitation> impregnation > mechanical mixing. This order correlated with the surface Ce3+ and Mn4+ content,oxygen vacancies and surface adsorbed oxygen species concentration, and the amount of acidic sitesand acidic strength. This trend is related to redox interactions between MnOx and CeO2. The catalystformed by a hydrothermal treatment exhibited excellent physicochemical properties, optimal catalyticperformance, and good H2O resistance in NH3‐SCR reaction. This was attributed to incorporationof Mnn+ into the CeO2 lattice to form a uniform ceria‐based solid solution (containing Mn‐O‐Cestructures). Strengthening of the electronic interactions between MnOx and CeO2, driven by thehigh‐temperature and high‐pressure conditions during the hydrothermal treatment also improved the catalyst characteristics. Thus, the hydrothermal treatment method is an efficient and environment‐friendly route to synthesizing low‐temperature denitrification (deNOx) catalysts.
基金supported by the National Basic Research Program of China (973 Program)(No. 2004CB217804)the Science and Technology Development Project of PetroChina (050203-01-06)
文摘NaY Zeolite was synthesized in a rotating packed bed （RPB） for the first time. A Si-A1 gel with a specific composition was used as the structure-directing agent. The as-synthesized NaY Zeolite was characterized with scanning electron microscopy （SEM）, X-ray diffraction （XRD） and specific surface area （BET）. The characterization result showed that the NaY Zeolite had a particle size of approximately 200 rim, n（SiO2）/n（Al203） ratio of 5.03, crystallinity of 96% and specific surface area of 714 m2/g. The experimental results indicated that the structure of NaY Zeolite was related to the synthesis conditions （such as reactors, crystallization time and so on）. The micromixing efficiency was proven to be the most important factor for synthesis of NaY Zeolite in the high-gravity environment in RPB.
基金This work is supported by the National Natural Science Foundation of China for Prominent Younth(No.59625306)National Emphasis Basis Subject(973.Programn)G1999054309-4.
文摘Collagen materials were crosslinked by 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) in the presence of chondroitin sulfate (CS), one of glycosaminoglycans (GAGS). PVA and chitosan were also blended with collagen. The physical and chemical properties of the matrices were characterized by SEM, DSC, and ESCA. L929 cells were implanted on the matrices to show the cytotoxic and the biological characters of the materials. The results indicate that EDC is an effective and non-cytotoxic cross-link reagent, which can replace the common dialdehyde reagent. The attachment of CS can improve the stability of collagen and accelerate cell growth. The addition of PVA can prepare porous matrices with smaller bore size. There are reactions between the chitosan and collagen, and the composite has good biological character. The presence of chitosan can also increase the amount of incorporated CS.
基金financially supported by grants from the National Natural Science Foundation of China(31901692)2020 Li Ka Shing Foundation Cross-Disciplinary Research Grant(2020LKSFG02E)Natural Science Foundation of Guangdong Province,China(2021A1515011495)。
文摘Marine algae are valuable sources of health-promoting molecules that have been consumed by Asians for decades.Among aquatic flora,marine algae stand out in terms of high content of marine algae polysaccharides(MAP)such as carrageenan,alginate,fucoidan,laminaran,agarose,rhamnan,and ulvan.When hydrolyzed,MAP generate marine algae oligosaccharides(MAO),which have attracted interest in recent years due to their superior solubility compared with MAP.Besides,MAO have been demonstrated numerous biological activities including antioxidant,antidiabetic,anti-inflammatory,antimicrobial,and prebiotic activities.Thus,this review summarizes the main chemical classes of MAO,their sources,and the main processes used for their production(i.e.,physical,chemical,and biological methods),coupled with a discussion of the advantages and disadvantages of these methods.Highlights of the biological activities of MAO and their potential applications in food,nutraceutical,and pharmaceuticals would also be discussed and summarized.
基金the National Natural ScienceFoundation of China(Nos.21206171,21376010)the Project of Natural Science Foundation of Beijing(No.2152012)+1 种基金the Young Elite Teacher Project(No.27170115004/027)the Project of 2011 Collaborative Innovation for Green Printing and Publishing Technology and the Project of Beijing Municipal Commission of Educatio (No.km201410005007)for the financial supports
文摘The thermally expandable microspheres（TEMs） were prepared via suspension polymerization with acrylonitrile（AN）, methyl methacrylate（MMA） and methyl acrylate（MA） as monomers and n-hexane as the blowing agent. Meanwhile, a novel type of functional and conductive thermal expandable microsphere was obtained through strongly covering the surface of microsphere by conductive polymers with the mass loading of 1.5%. The optimal conditions to prepare high foaming ratio and equally distributed microcapsules were investigated with AN-MMA-MA in the proportion of 70%/20%/10%（m/m/m）, and 25 wt% of n-hexane in oil phase. The further investigation results showed that the unexpanded TEMs were about 30 μm in diameter and the maximum expansion ratio was nearly 125 times of original volume. The polypyrrole（PPy） was smoothly coated on the surface of the TEMs and the expansion property of PPy-coated TEMs was almost the same as the uncoated TEMs. Moreover, the structure and expanding performance of TEMs and PPy-coated TEMs were characterized by scanning electron microscopy（SEM）, laser particle size analyzer and dilatometer（DIL）.
基金supported by the National Basic Research and Development Program of China (No. 2009CB220100)Beijing Excellent Talent Support Program (No. 20071D1600300396)
文摘Three co-impregnation/chemical reduction methods in acidic solutions of pH 〈 1,including ethylene glycol （EG）,NaBH4,and HCOOH,were compared for Pt-WO3/C catalysts.Pt-WO3/C catalysts containing 10 wt.% and 20 wt.% platinum per carbon were prepared by the three methods; their morphology and electrocatalytic activities were characterized.The 20 wt.% Pt-WO3/C catalyst prepared by the co-impregnation/EG method presented the optimal dispersion with an average particle size of 4.6 nm and subsequently the best electrocatalytic activity,and so,it was further characterized.Its anodic peak current density for ethanol oxidation from linear sweep voltammetry （LSV） is 7.9 mA·cm^-2,which is 1.4 and 5.2 times as high as those of the catalysts prepared by co-impregnation/NaBH4 and co-impregnation/ HCOOH reduction methods,2.1 times as high as that of the 10 wt.% Pt-WO3/C catalyst prepared by co-impregnation/EG method,respectively.
基金supported by the National key R & D plan for the 13th five year plan (No. 2017YFC0805200)the Qingdao science and technology plan project (No.19-3-2-6-zhc)+1 种基金the Natural Science Foundation of Shandong Province (No. ZR2019MEE118)the National Natural Science Foundation of China (No. 51974179)。
文摘To relieve dust pollution in open cut coal mines and reduce the hazards of coal dust pollution to the environment and workers we optimized the synthesis of a dust suppressant by graft copolymerization of environmentally friendly soy protein isolate with methyl methacrylate.This dust suppressant could effectively control dust pollution in open cut coal mines. The optimized conditions for graft copolymerization in this case were determined by a response surface experiment designed with Design-Expert 10 software. Characterization by scanning electron microscopy showed a significant morphology change of the dust suppressant and the generation of a rigid and dense layer on its surface after interacting with coal dust.The layer exhibited good bonding and dust suppression performance. The analysis with Fourier-transform infrared spectroscopy revealed the appearance of new absorption peaks near 1300, 1072, and 1631 cm, demonstrating effective graft copolymerization. The proposed dust suppressant exhibited excellent wind erosion resistance, with a resistance that exceeded 90% at a wind speed of 6.5 m/sec. The successful graft copolymerization and effective bonding and curing of the dust suppressant on coal dust were experimentally verified.This is of great significance to the control of coal dust pollution.
