ZnO is a highly significant II-VI semiconductor known for its excellent optoelectronic properties,making it widely applicable and promising for use in light-emitting devices,solar cells,lasers,and photodetectors.The m...ZnO is a highly significant II-VI semiconductor known for its excellent optoelectronic properties,making it widely applicable and promising for use in light-emitting devices,solar cells,lasers,and photodetectors.The methods for preparing ZnO are diverse,and among them,the hydrothermal method is favored for its simplicity,ease of operation,and low cost,making it an optimal choice for ZnO single-crystal growth.Most studies investigating the effects of different hydrothermal experimental parameters on the morphology and performance of ZnO nano-materials typically focus on only 2—3 variable parameters,with few examining the impact of all possible experimental parameter changes on ZnO nano-mate-rials.The principles of the hydrothermal method and its advantages in nano-material preparation were briefly introduced in this article.The detailed discussion on the influence of various experimental parameters on the preparation of ZnO nano-materials was provided,which including reaction materials,Zn^(2+)/OH^(-)ratio,reaction time and temperature,additives,experimental equipment,and annealing conditions.The review co-vers how different experimental parameters affect the morphology and performance of the materials,as well as how different rare earth doping elements influence the performance of ZnO nano-materials.It is hoped that this work will contribute to future research on the hydrothermal synthesis of nano-materials.展开更多
A dynamic quasi-continuum model is presented to analyze free vibration of plate-type cubic crystal nano-materials.According to the Hamilton principle,fundamental governing equations in terms of displacement components...A dynamic quasi-continuum model is presented to analyze free vibration of plate-type cubic crystal nano-materials.According to the Hamilton principle,fundamental governing equations in terms of displacement components and angles of rotations are given.As an application of the model,the cylindrical bending deformation of the structure fixed at two ends is analyzed,and a theoretical formula evaluating the fundamental frequency is obtained by using Galerkin's method.Meanwhile,the solution for the classical continuous plate model is also derived,and the size-dependent elastic modulus and Poisson's ratio are taken in computation.The frequencies corresponding to different atomic layers are numerically presented for the plate-type NaC l nano-materials.Furthermore,a molecular dynamics(MD)simulation is conducted with the code LAMMPS.The comparison shows that the present quasi-continuum model is valid,and it may be used as an alternative model,which reflects scale effects in analyzing dynamic behaviors of such plate-type nano-materials.展开更多
One-dimensional carbon nano-materials （ODCNMs） synthesized from ethanol flames exhibit various agglomerated morphologies, such as ＂chrysanthemum-like＂, ＂hairball-like＂ or ＂orange-peel-like＂, ＂vertically alig...One-dimensional carbon nano-materials （ODCNMs） synthesized from ethanol flames exhibit various agglomerated morphologies, such as ＂chrysanthemum-like＂, ＂hairball-like＂ or ＂orange-peel-like＂, ＂vertically aligned＂ and ＂wrinkling-pileup＂. The present work studied the agglomerating process and the growth mechanism by using scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. It is thought that the size and distribution of the catalyst particles produced from pretreatment of the substrates play a key role during the formation of agglomerations. It is expected that the steady growth of ODCNMs in flames will be improved through the preparation of the catalysts.展开更多
On February 28th, 2005, AQSIQ (the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China), and SAC (the Standardization Administration of P. R. China)jointly ho...On February 28th, 2005, AQSIQ (the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China), and SAC (the Standardization Administration of P. R. China)jointly hosted the press conference on seven items of national standards on nano-materials in Beijing. The seven items of national standards were approved on Sept. 29th and Dec. 27th, 2004 respectively by SAC, and publicized in Jan. 2005. They will be formally put into practice from April 1st, 2005.展开更多
Nano-scale Ni（OH）2 doped with Zn was prepared by precipitation transformation method and characterized by XRD and TEM. The electrochemical performance was investigated by cyclic voltammetry （CV） and constant curre...Nano-scale Ni（OH）2 doped with Zn was prepared by precipitation transformation method and characterized by XRD and TEM. The electrochemical performance was investigated by cyclic voltammetry （CV） and constant current technology. The measurement results indicate that the lattice parameters of nano-scale Ni（OH）2 are changed and the agglomeration of particles becomes obvious with the increased Zn-doped content. Compared with un-doped one, the discharge specific capacities ofnano-scale Ni（OH）2 doped with 10% Zn are enhanced by 8% and 6%, respectively, at the discharge rate of 0.2C and 3C. After 110 cycles, the discharge specific capacity of the sample doped with 10% zinc is still above 85% of its initial capacity discharged at 0.2C. Therefore, a suitable Zn-doped content is beneficial to improving the discharge performance of nano-scale Ni（OH）2.展开更多
Persistent organic pollutants （POPs） in soils are an environmental concern due to their long-term bioavailability, which could be reduced by adding adsorbents. However, testing of these adsorbents is necessary prior...Persistent organic pollutants （POPs） in soils are an environmental concern due to their long-term bioavailability, which could be reduced by adding adsorbents. However, testing of these adsorbents is necessary prior to widespread field application. The effects of three adsorbents, nano-organic montmorillonite, nano-organic silicon dioxide （SiOs）, and activated carbon, on hexachlorobenzene （HCB） and pentachlorobenzene （PeCB） accumulation in rice （Oryza sativa L.） plants were tested in a greenhouse experiment using two soils, a Hydragric Acrisol （Ac） and a Gleyi-Stagnic Anthrosol （An）. The bioconcentration factors （BCFs） of HCB and PeCB to rice roots were 2.3-3.7 and 2.0 3.0 times those to rice shoots, respectively. The applications of the three adsorbents decreased HCB and PeCB extractability in Ac, while only the application of activated carbon decreased their extractability in An. The bioavailability of HCB and PeCB to rice plants in Ac was higher than that in An. In Ac, the applications of nano-organic SiOs and activated carbon decreased the BCF of HCB to rice roots by 16.1% and 26.8%, respectively, whereas only the application of activated carbon decreased the BCF of PeCB to rice roots by 31.4%, compared to the control. In An, only the application of activated carbon decreased the BCFs of HCB and PeCB to rice roots by 22.9% and 18.2%, respectively, compared to the control. However, the application of nano-organic montmorillonite inhibited rice growth in both soils. The results of this study suggested that the effectiveness of adsorbents would vary with pollutant and soil types, providing a reference point for developing efficient adsorbents to reduce the ecological risk of POPs.展开更多
Gas hydrates have recently emerged as a better alternative for the production,storage,and transportation of natural gases.However,factors like slow formation rate and limited storage capacity obstruct the possible ind...Gas hydrates have recently emerged as a better alternative for the production,storage,and transportation of natural gases.However,factors like slow formation rate and limited storage capacity obstruct the possible industrial application of this technique.Different types of promoters and synergists have been developed that can improve the kinetics and storage capacity of gas hydrates.This review focuses on different kinetic promoters and synergists that can be utilized to enhance the storage capacity of hydrates.The main characteristics,structure and the possible limitations of the use of these promoters are likewise portrayed in detail.The relationship between structure and storage capacity of hydrates have also been discussed in the review.Current status of production of gas from hydrates,their restrictions,and future difficulties have additionally been addressed in the ensuing areas of the review.展开更多
A new kind of nano-rod shaped polycarboxylic acid slump-retaining agent was synthesized.Transmission electron microscope(TEM) experiment showed that the nano-rod was bound together as macromolecular aggregates in solu...A new kind of nano-rod shaped polycarboxylic acid slump-retaining agent was synthesized.Transmission electron microscope(TEM) experiment showed that the nano-rod was bound together as macromolecular aggregates in solution.Application performance studying suggested that this kind nano-sized polymer material had excellently plasticity-retaining performance in cement-based materials and could improve endurance performance of hardened cement-based materials distinctly.The concrete with an initial slump of 2-9 cm could achieve 3 h plasticity-retaining performance with the help of this kind nano-rod.The product had extremely wide application value in the market.展开更多
The application of induction plasma technology developed for the synthesis of nano- metric powders is summarized. A brief description of the scientific basis for the induction plasma processes is given, followed by th...The application of induction plasma technology developed for the synthesis of nano- metric powders is summarized. A brief description of the scientific basis for the induction plasma processes is given, followed by the presentation of an induction plasma system developed by Tekna, together with various examples of the nanopowders synthesized using its facilities. The advantages of the induction plasma process over alternative techniques and its adaptability into industrial- scale operation is particularly illustrated. Some specific issues related to the nanopowder synthesis process are also discussed.展开更多
The design of efficient and low-cost multifunctional electrocatalysts for hydrogen evolution reaction(HER), oxygen evolution reaction(OER) and oxygen reduction reaction(ORR) is critical for the development of clean en...The design of efficient and low-cost multifunctional electrocatalysts for hydrogen evolution reaction(HER), oxygen evolution reaction(OER) and oxygen reduction reaction(ORR) is critical for the development of clean energy. Two-dimensional(2D) carbon-based nano-materials are becoming more and more popular in heterogeneous catalysis due to their cost-effective and multi-scale tunability as single-atom catalysis(SACs) substrates. In this paper, by using first-principles calculation, we designed and demonstrated a novel macropore T-carbon [110](TC) monolayer as 2D electrocatalyst substrate for HER/OER/ORR, and the synergistic modification of the transition metal and nonmetal atoms(TM-X) were investigated to enhance the multifunctional electrocatalytic performance. We screened out the Co embedded in N-doped TC(Co3@N-TC) from 30 TM@X-TC monolayers as a trifunctional electrocatalysts, which exhibits superior performance for HER/ORR/OER on both thermodynamic and kinetic scales, and with excellent thermal and electrochemical stability. Then, the TC monolayer is naturally macropore with a diameter of 5.36 A and exhibits excellent adsorption capacity for the intermediates and products of the redox reactions. Moreover, we revealed the origin of the electrocatalytic activity using the crystal orbital Hamilton population(COHP) and the molecular orbitals(MOs). The d orbital of Co3@N-TC is significantly hybridized with the p orbital of the intermediates, so that the lone electrons initially occupied in the antibonding state pair up and occupy the downward bonding state, allowing *OH to be appropriately adsorbed onto the TC monolayer. This work not only demonstrates that the TM@X-TC monolayer is a superior synergistic trifunctional electrocatalyst, but also reveals a macropore monolayer material with potential applications in electrocatalysis.展开更多
Surfactant complexation may have significant effects on the environmental behavior of nano-particles.In order to understand the ecological exposure of nano-materials,it is important to determine the stability and mobi...Surfactant complexation may have significant effects on the environmental behavior of nano-particles.In order to understand the ecological exposure of nano-materials,it is important to determine the stability and mobility of surfactant-complexed nano-materials in aqueous systems.In this study,the aggregation and transport of C_(60)complexed by the surfactant sodium dodecyl benzene sulfonate(SDBS)were investigated.It was found that SDBS-complexed C_(60)had aζ-potential of-49.5 m V under near-neutral p H conditions and remained stable during an aging period of 15 days.It had a critical coagulation concentration of 550 mmol/L for Na Cl,which was higher than common natural colloids and many kinds of raw nano-materials,and was comparable to those of many kinds of surface-modified nano-materials.SDBS enhanced the stability of C_(60)colloid;however,at the same time,it also enhanced the colloidal particle aggregation rate.Much higher mobility was found for SDBS-complexed C(60)than C_(60)colloid.Increase in ionic strength,Ca^(2+)concentration or Al^(3+)concentration decreased the mobility.In general,SDBS-complexed C_(60)had high stability and mobility.展开更多
Magnetic starch particles （MSPs） were synthesized in water-in-oil mieroemulsion at room temperature. MSPs were characterized by transmission electron microscopy （TEM）, Fourier transform infrared spectrometry （FTI...Magnetic starch particles （MSPs） were synthesized in water-in-oil mieroemulsion at room temperature. MSPs were characterized by transmission electron microscopy （TEM）, Fourier transform infrared spectrometry （FTIR）, zeta potential system, thermogravimetric analysis （TGA） and vibrating sample magnetometry （VSM）. The average diameter of the MSPs was 220 nm, dispersed with well-proportioned size and magnetic resonance, the saturation magnetization was 3.64 A.mR/kg. MSP was coated with poly-L-lysine （PLL）, and then the surface of PLL-MSP was combined with fluorescein isothiocynate （FITC）. Results show that fluorescent/magnetic starch particles （FMSPs） are of stable photo-bleaching capability compared with free FITC, with low bio-toxicity and certain function of magnetic separation. It is expected that FMSPs are bifimctional nano-materials including fluorescence labelling and magnetic separation.展开更多
Spherical Nano-scale nickel hydroxide was prepared through precipitation transmutation method by controlling the transmutation conditions in this paper. The measurement results of XRD and TEM indicate that the crystal...Spherical Nano-scale nickel hydroxide was prepared through precipitation transmutation method by controlling the transmutation conditions in this paper. The measurement results of XRD and TEM indicate that the crystallization of the nano-scale nickel hydroxide isβ-style and its shape is spherical with a diameter of 40～70 nanometer. The adulteration experiment shows that the adulteration ratio of nano- scale Ni(OH) 2 in common spherical micrometer-scale Ni(OH) 2 exists a optimal value (1∶9). And at this point, the utilization ratio of Ni(OH) 2 in electrodes can be raised by 10%, and the nano-scale nickel hydroxide with sphericity shape shows a better adulteration performance than that with needle shape.展开更多
Plasma technology has some shortcomings, such as higher energy consumption and byproducts produced in the reaction process. However non-thermal plasma associated with catalyst can resolve these problems. So this kind ...Plasma technology has some shortcomings, such as higher energy consumption and byproducts produced in the reaction process. However non-thermal plasma associated with catalyst can resolve these problems. So this kind of technology was paid more and more attention to treat waste gas. In this paper, we make use of this technology to decompose toluene under different electric field and packed materials. At the same time, the mechanism of toluene decomposition using plasma and catalyst is discussed. The experimental results show toluene decomposition increases with electric field strength increasing and flow velocity and initial concentration decreasing. There are four conditions in plasma: without packed materials (1);with packed materials (2);with BaTiO3 in the surfaces of packed materials (3);and with nanometer Ba0.8Sr0.2Zr0.1Ti0.9O3 (4). Toluene decomposition represents a obvious trend, that is, η(4) > η(3) > η(2) > η(1). The best decomposition efficiency of toluene arrives at 95%.展开更多
Commonly transition metal nano particle are synthesized by physical, chemical or electrochemical methods. In the present work colloidal iridium nanoparticles were synthesized by chemical oxidation method with differen...Commonly transition metal nano particle are synthesized by physical, chemical or electrochemical methods. In the present work colloidal iridium nanoparticles were synthesized by chemical oxidation method with different surfactants like poly vinyl pyrrolidone (PVP), poly vinyl alcohol (PVA) and poly oxyethylene lauryl ether (POLE). It was found that shape and size of Ir-nano particles resulted were related to kind of capping agent (surfactant) used. The characterization of the synthesized nano particle has been carried out by UV-vis, X-ray diffraction (XRD), FT-IR, scanning electron microscopy (SEM) and transmission electron microscopic (TEM) techniques. UV-vis and FT-IR confirm the oxidation of IrCl3 into IrO2 while XRD confirms the amorphous nature of the iridium nanoparticles synthesized. The morphology and size of the particle were confirmed by TEM. The average particle size determined by Scherrer equation was about 4.12 nm to 4.23 nm with PVP, 2.74 to 3.36 nm with PVA and 20.41 to 42.25 nm with POLE. Poly oxyethylene lauryl ether particles were not further analyzed because of their large size and less stability. Further particle size was confirmed with TEM, which was 4.5 nm with PVP and 7.0 nm with PVA. The particles are spherical with no agglomeration tendency.展开更多
Isothermal oxidation behavior of chromium with and without nanometric sol-gel CeO2 coating is studied at 1000℃ in air. Scanning electron microscopy （SEM） and transmission electron microscopy （TEM） are used to exa...Isothermal oxidation behavior of chromium with and without nanometric sol-gel CeO2 coating is studied at 1000℃ in air. Scanning electron microscopy （SEM） and transmission electron microscopy （TEM） are used to examine the surface morphology and microstructure of their oxide films. It is found that ceria coating greatly improves the anti-oxidation property of chromium. Laser Raman spectrometer and X-ray diffraction spectrometer （XRD） are also used to study the stress level in oxide films formed on ceria-coated and ceria-free Cr. The difference in oxidation behavior is mainly attributed to the fact that ceria greatly reduces the growth speed and grain size of Cr2O3 film, and this fine grain-sized Cr2O3 film probably has better high temperature plasticity, i.e. oxide film can relieve parts of compressive stress by means of creeping. XRD and Raman testing results both show the stress declination due to nano-CeO2 application, and their deviation is analyzed conceming to the rare earth effect.展开更多
The technology of forming and machining lump nano-materials has beeninvestigated. Grinding, abrasive machining test has been conducted to Fe, Co, Ni and Al lumpnano-materials. Experiments have been done to measure gri...The technology of forming and machining lump nano-materials has beeninvestigated. Grinding, abrasive machining test has been conducted to Fe, Co, Ni and Al lumpnano-materials. Experiments have been done to measure grinding force, grinding thermal, machiningroughness and micro-hardness. Image analysis is carried out by metallographic and scanning tunnelmicroscopic microscope. Researches provide the basis data for forming and machining lumpnano-materials.展开更多
The influence of transforming pH values on the electrochemical performance of nano-scale Ni （OH）2 was analyzed. The measurement results of XRD indicate that the nano-scale Ni （OH） 2 prepared at different transform...The influence of transforming pH values on the electrochemical performance of nano-scale Ni （OH）2 was analyzed. The measurement results of XRD indicate that the nano-scale Ni （OH） 2 prepared at different transformations of pH value is β （ Ⅱ ）-phase with different crystal lattice parameters. Cyclic voltammograms （CV） and electrochemical impedance spectroscopy（EIS） measurement results show that transformations of pH value affect the proton diffusion coefficient （D） and charge-transfer resistance （Re,） of the material. The simulation of.cell experiment shows that the sample prepared at a pH of 10. 1 exhibits the maximum specific capacity （327.8 mAh/g） and higher discharge platform, the discharge performance of electrodes depends on both D and Rct, so the kinetics characteristics that electrodes reaction is controlled by both mass-transfer step and charge- transfer step are put forward.展开更多
The feasibility of embedding 40nm ZnO particles into porous textile material by using ultrasonic and its influence factors were studied. Through investigations, it is proved that the higher the concentration of nanopa...The feasibility of embedding 40nm ZnO particles into porous textile material by using ultrasonic and its influence factors were studied. Through investigations, it is proved that the higher the concentration of nanoparticle suspension is, the higher the weight of embedding percentage (EPW) is. However, the increasing trend of EPW will minish quickly when the concentration exceeds 1%. In addition, the longer the process time of ultrasonic is, the higher EPW is. EPW is always higher when the distance between film and ultrasonic transducer is 1/2λ and 3/2λ, and lower when the distance is 1λ and 2λ. For 40nm ZnO particles, EPW of the film effected by ultrasonic with the frequency of 42kHz reaches the maximum.展开更多
文摘ZnO is a highly significant II-VI semiconductor known for its excellent optoelectronic properties,making it widely applicable and promising for use in light-emitting devices,solar cells,lasers,and photodetectors.The methods for preparing ZnO are diverse,and among them,the hydrothermal method is favored for its simplicity,ease of operation,and low cost,making it an optimal choice for ZnO single-crystal growth.Most studies investigating the effects of different hydrothermal experimental parameters on the morphology and performance of ZnO nano-materials typically focus on only 2—3 variable parameters,with few examining the impact of all possible experimental parameter changes on ZnO nano-mate-rials.The principles of the hydrothermal method and its advantages in nano-material preparation were briefly introduced in this article.The detailed discussion on the influence of various experimental parameters on the preparation of ZnO nano-materials was provided,which including reaction materials,Zn^(2+)/OH^(-)ratio,reaction time and temperature,additives,experimental equipment,and annealing conditions.The review co-vers how different experimental parameters affect the morphology and performance of the materials,as well as how different rare earth doping elements influence the performance of ZnO nano-materials.It is hoped that this work will contribute to future research on the hydrothermal synthesis of nano-materials.
文摘A dynamic quasi-continuum model is presented to analyze free vibration of plate-type cubic crystal nano-materials.According to the Hamilton principle,fundamental governing equations in terms of displacement components and angles of rotations are given.As an application of the model,the cylindrical bending deformation of the structure fixed at two ends is analyzed,and a theoretical formula evaluating the fundamental frequency is obtained by using Galerkin's method.Meanwhile,the solution for the classical continuous plate model is also derived,and the size-dependent elastic modulus and Poisson's ratio are taken in computation.The frequencies corresponding to different atomic layers are numerically presented for the plate-type NaC l nano-materials.Furthermore,a molecular dynamics(MD)simulation is conducted with the code LAMMPS.The comparison shows that the present quasi-continuum model is valid,and it may be used as an alternative model,which reflects scale effects in analyzing dynamic behaviors of such plate-type nano-materials.
基金Supported by the Scientific Research Foundationfor the Returned Overseas Chinese Scholars of Chinese Ministry Edu-cation (200233)
文摘One-dimensional carbon nano-materials （ODCNMs） synthesized from ethanol flames exhibit various agglomerated morphologies, such as ＂chrysanthemum-like＂, ＂hairball-like＂ or ＂orange-peel-like＂, ＂vertically aligned＂ and ＂wrinkling-pileup＂. The present work studied the agglomerating process and the growth mechanism by using scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. It is thought that the size and distribution of the catalyst particles produced from pretreatment of the substrates play a key role during the formation of agglomerations. It is expected that the steady growth of ODCNMs in flames will be improved through the preparation of the catalysts.
文摘On February 28th, 2005, AQSIQ (the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China), and SAC (the Standardization Administration of P. R. China)jointly hosted the press conference on seven items of national standards on nano-materials in Beijing. The seven items of national standards were approved on Sept. 29th and Dec. 27th, 2004 respectively by SAC, and publicized in Jan. 2005. They will be formally put into practice from April 1st, 2005.
基金Project(BK2008591) supported by the Natural Science Foundation of Jiangsu Province,ChinaProject(2009RFQXG065) supported by Harbin Special Foundation of Technological Innovation Talent,China
文摘Nano-scale Ni（OH）2 doped with Zn was prepared by precipitation transformation method and characterized by XRD and TEM. The electrochemical performance was investigated by cyclic voltammetry （CV） and constant current technology. The measurement results indicate that the lattice parameters of nano-scale Ni（OH）2 are changed and the agglomeration of particles becomes obvious with the increased Zn-doped content. Compared with un-doped one, the discharge specific capacities ofnano-scale Ni（OH）2 doped with 10% Zn are enhanced by 8% and 6%, respectively, at the discharge rate of 0.2C and 3C. After 110 cycles, the discharge specific capacity of the sample doped with 10% zinc is still above 85% of its initial capacity discharged at 0.2C. Therefore, a suitable Zn-doped content is beneficial to improving the discharge performance of nano-scale Ni（OH）2.
基金supported by the Open Fund Project of Jiangsu Key Laboratory of Agricultural Meteorology, Nanjing University of Information Science and Technology, China (No. JKLAM1605)
文摘Persistent organic pollutants （POPs） in soils are an environmental concern due to their long-term bioavailability, which could be reduced by adding adsorbents. However, testing of these adsorbents is necessary prior to widespread field application. The effects of three adsorbents, nano-organic montmorillonite, nano-organic silicon dioxide （SiOs）, and activated carbon, on hexachlorobenzene （HCB） and pentachlorobenzene （PeCB） accumulation in rice （Oryza sativa L.） plants were tested in a greenhouse experiment using two soils, a Hydragric Acrisol （Ac） and a Gleyi-Stagnic Anthrosol （An）. The bioconcentration factors （BCFs） of HCB and PeCB to rice roots were 2.3-3.7 and 2.0 3.0 times those to rice shoots, respectively. The applications of the three adsorbents decreased HCB and PeCB extractability in Ac, while only the application of activated carbon decreased their extractability in An. The bioavailability of HCB and PeCB to rice plants in Ac was higher than that in An. In Ac, the applications of nano-organic SiOs and activated carbon decreased the BCF of HCB to rice roots by 16.1% and 26.8%, respectively, whereas only the application of activated carbon decreased the BCF of PeCB to rice roots by 31.4%, compared to the control. In An, only the application of activated carbon decreased the BCFs of HCB and PeCB to rice roots by 22.9% and 18.2%, respectively, compared to the control. However, the application of nano-organic montmorillonite inhibited rice growth in both soils. The results of this study suggested that the effectiveness of adsorbents would vary with pollutant and soil types, providing a reference point for developing efficient adsorbents to reduce the ecological risk of POPs.
基金We gratefully acknowledge the financial assistance provided by Science and Engineering Research Board(SERB)under the Department of Science and Technology(DST)New Delhi,India,and Ministry of Earth Sciences(MoES)Government of India,New Delhi to the Department of Petroleum Engineering,Indian Institute of Techology(ISM),Dhanbad,India.
文摘Gas hydrates have recently emerged as a better alternative for the production,storage,and transportation of natural gases.However,factors like slow formation rate and limited storage capacity obstruct the possible industrial application of this technique.Different types of promoters and synergists have been developed that can improve the kinetics and storage capacity of gas hydrates.This review focuses on different kinetic promoters and synergists that can be utilized to enhance the storage capacity of hydrates.The main characteristics,structure and the possible limitations of the use of these promoters are likewise portrayed in detail.The relationship between structure and storage capacity of hydrates have also been discussed in the review.Current status of production of gas from hydrates,their restrictions,and future difficulties have additionally been addressed in the ensuing areas of the review.
基金the Jiangsu Province Natural Science Foundation(No.BK2008520)the Jiangsu Postdoctoral Research Funds(No.0901008C)the China Postdoctoral Science Foundation(No.20090461120)
文摘A new kind of nano-rod shaped polycarboxylic acid slump-retaining agent was synthesized.Transmission electron microscope(TEM) experiment showed that the nano-rod was bound together as macromolecular aggregates in solution.Application performance studying suggested that this kind nano-sized polymer material had excellently plasticity-retaining performance in cement-based materials and could improve endurance performance of hardened cement-based materials distinctly.The concrete with an initial slump of 2-9 cm could achieve 3 h plasticity-retaining performance with the help of this kind nano-rod.The product had extremely wide application value in the market.
文摘The application of induction plasma technology developed for the synthesis of nano- metric powders is summarized. A brief description of the scientific basis for the induction plasma processes is given, followed by the presentation of an induction plasma system developed by Tekna, together with various examples of the nanopowders synthesized using its facilities. The advantages of the induction plasma process over alternative techniques and its adaptability into industrial- scale operation is particularly illustrated. Some specific issues related to the nanopowder synthesis process are also discussed.
基金supported by the Natural Science Basic Research Program of Shaanxi (No. 2023-JC-YB-065)the Fund of State Key Laboratory of IPOC(BUPT)(No. IPOC2019A013)+2 种基金the Natural Science Foundation of Shaanxi Province (No. 2021JM-371)the Open-Foundation of Key Laboratory of Laser Device Technology,China North Industries Group Corporation Limited (No. KLLDT202103)the Project funded by China Postdoctoral Science Foundation(No. 2022M720516)。
文摘The design of efficient and low-cost multifunctional electrocatalysts for hydrogen evolution reaction(HER), oxygen evolution reaction(OER) and oxygen reduction reaction(ORR) is critical for the development of clean energy. Two-dimensional(2D) carbon-based nano-materials are becoming more and more popular in heterogeneous catalysis due to their cost-effective and multi-scale tunability as single-atom catalysis(SACs) substrates. In this paper, by using first-principles calculation, we designed and demonstrated a novel macropore T-carbon [110](TC) monolayer as 2D electrocatalyst substrate for HER/OER/ORR, and the synergistic modification of the transition metal and nonmetal atoms(TM-X) were investigated to enhance the multifunctional electrocatalytic performance. We screened out the Co embedded in N-doped TC(Co3@N-TC) from 30 TM@X-TC monolayers as a trifunctional electrocatalysts, which exhibits superior performance for HER/ORR/OER on both thermodynamic and kinetic scales, and with excellent thermal and electrochemical stability. Then, the TC monolayer is naturally macropore with a diameter of 5.36 A and exhibits excellent adsorption capacity for the intermediates and products of the redox reactions. Moreover, we revealed the origin of the electrocatalytic activity using the crystal orbital Hamilton population(COHP) and the molecular orbitals(MOs). The d orbital of Co3@N-TC is significantly hybridized with the p orbital of the intermediates, so that the lone electrons initially occupied in the antibonding state pair up and occupy the downward bonding state, allowing *OH to be appropriately adsorbed onto the TC monolayer. This work not only demonstrates that the TM@X-TC monolayer is a superior synergistic trifunctional electrocatalyst, but also reveals a macropore monolayer material with potential applications in electrocatalysis.
基金supported by the National Natural Science Foundation of China(No.41473113,41273123)the National Basic Research Program(973)of China(No.2011CB933700-G)
文摘Surfactant complexation may have significant effects on the environmental behavior of nano-particles.In order to understand the ecological exposure of nano-materials,it is important to determine the stability and mobility of surfactant-complexed nano-materials in aqueous systems.In this study,the aggregation and transport of C_(60)complexed by the surfactant sodium dodecyl benzene sulfonate(SDBS)were investigated.It was found that SDBS-complexed C_(60)had aζ-potential of-49.5 m V under near-neutral p H conditions and remained stable during an aging period of 15 days.It had a critical coagulation concentration of 550 mmol/L for Na Cl,which was higher than common natural colloids and many kinds of raw nano-materials,and was comparable to those of many kinds of surface-modified nano-materials.SDBS enhanced the stability of C_(60)colloid;however,at the same time,it also enhanced the colloidal particle aggregation rate.Much higher mobility was found for SDBS-complexed C(60)than C_(60)colloid.Increase in ionic strength,Ca^(2+)concentration or Al^(3+)concentration decreased the mobility.In general,SDBS-complexed C_(60)had high stability and mobility.
基金Project(200501) supported by the "985" Program of China
文摘Magnetic starch particles （MSPs） were synthesized in water-in-oil mieroemulsion at room temperature. MSPs were characterized by transmission electron microscopy （TEM）, Fourier transform infrared spectrometry （FTIR）, zeta potential system, thermogravimetric analysis （TGA） and vibrating sample magnetometry （VSM）. The average diameter of the MSPs was 220 nm, dispersed with well-proportioned size and magnetic resonance, the saturation magnetization was 3.64 A.mR/kg. MSP was coated with poly-L-lysine （PLL）, and then the surface of PLL-MSP was combined with fluorescein isothiocynate （FITC）. Results show that fluorescent/magnetic starch particles （FMSPs） are of stable photo-bleaching capability compared with free FITC, with low bio-toxicity and certain function of magnetic separation. It is expected that FMSPs are bifimctional nano-materials including fluorescence labelling and magnetic separation.
文摘Spherical Nano-scale nickel hydroxide was prepared through precipitation transmutation method by controlling the transmutation conditions in this paper. The measurement results of XRD and TEM indicate that the crystallization of the nano-scale nickel hydroxide isβ-style and its shape is spherical with a diameter of 40～70 nanometer. The adulteration experiment shows that the adulteration ratio of nano- scale Ni(OH) 2 in common spherical micrometer-scale Ni(OH) 2 exists a optimal value (1∶9). And at this point, the utilization ratio of Ni(OH) 2 in electrodes can be raised by 10%, and the nano-scale nickel hydroxide with sphericity shape shows a better adulteration performance than that with needle shape.
文摘Plasma technology has some shortcomings, such as higher energy consumption and byproducts produced in the reaction process. However non-thermal plasma associated with catalyst can resolve these problems. So this kind of technology was paid more and more attention to treat waste gas. In this paper, we make use of this technology to decompose toluene under different electric field and packed materials. At the same time, the mechanism of toluene decomposition using plasma and catalyst is discussed. The experimental results show toluene decomposition increases with electric field strength increasing and flow velocity and initial concentration decreasing. There are four conditions in plasma: without packed materials (1);with packed materials (2);with BaTiO3 in the surfaces of packed materials (3);and with nanometer Ba0.8Sr0.2Zr0.1Ti0.9O3 (4). Toluene decomposition represents a obvious trend, that is, η(4) > η(3) > η(2) > η(1). The best decomposition efficiency of toluene arrives at 95%.
文摘Commonly transition metal nano particle are synthesized by physical, chemical or electrochemical methods. In the present work colloidal iridium nanoparticles were synthesized by chemical oxidation method with different surfactants like poly vinyl pyrrolidone (PVP), poly vinyl alcohol (PVA) and poly oxyethylene lauryl ether (POLE). It was found that shape and size of Ir-nano particles resulted were related to kind of capping agent (surfactant) used. The characterization of the synthesized nano particle has been carried out by UV-vis, X-ray diffraction (XRD), FT-IR, scanning electron microscopy (SEM) and transmission electron microscopic (TEM) techniques. UV-vis and FT-IR confirm the oxidation of IrCl3 into IrO2 while XRD confirms the amorphous nature of the iridium nanoparticles synthesized. The morphology and size of the particle were confirmed by TEM. The average particle size determined by Scherrer equation was about 4.12 nm to 4.23 nm with PVP, 2.74 to 3.36 nm with PVA and 20.41 to 42.25 nm with POLE. Poly oxyethylene lauryl ether particles were not further analyzed because of their large size and less stability. Further particle size was confirmed with TEM, which was 4.5 nm with PVP and 7.0 nm with PVA. The particles are spherical with no agglomeration tendency.
基金supported by National Natural Science Foundation of China (No.59231011)Natural Science Foundation of Jiangsu Province (No.07KJD430246).
文摘Isothermal oxidation behavior of chromium with and without nanometric sol-gel CeO2 coating is studied at 1000℃ in air. Scanning electron microscopy （SEM） and transmission electron microscopy （TEM） are used to examine the surface morphology and microstructure of their oxide films. It is found that ceria coating greatly improves the anti-oxidation property of chromium. Laser Raman spectrometer and X-ray diffraction spectrometer （XRD） are also used to study the stress level in oxide films formed on ceria-coated and ceria-free Cr. The difference in oxidation behavior is mainly attributed to the fact that ceria greatly reduces the growth speed and grain size of Cr2O3 film, and this fine grain-sized Cr2O3 film probably has better high temperature plasticity, i.e. oxide film can relieve parts of compressive stress by means of creeping. XRD and Raman testing results both show the stress declination due to nano-CeO2 application, and their deviation is analyzed conceming to the rare earth effect.
文摘The technology of forming and machining lump nano-materials has beeninvestigated. Grinding, abrasive machining test has been conducted to Fe, Co, Ni and Al lumpnano-materials. Experiments have been done to measure grinding force, grinding thermal, machiningroughness and micro-hardness. Image analysis is carried out by metallographic and scanning tunnelmicroscopic microscope. Researches provide the basis data for forming and machining lumpnano-materials.
基金the National Natural Science Foundation of China (Grant No.20271015)
文摘The influence of transforming pH values on the electrochemical performance of nano-scale Ni （OH）2 was analyzed. The measurement results of XRD indicate that the nano-scale Ni （OH） 2 prepared at different transformations of pH value is β （ Ⅱ ）-phase with different crystal lattice parameters. Cyclic voltammograms （CV） and electrochemical impedance spectroscopy（EIS） measurement results show that transformations of pH value affect the proton diffusion coefficient （D） and charge-transfer resistance （Re,） of the material. The simulation of.cell experiment shows that the sample prepared at a pH of 10. 1 exhibits the maximum specific capacity （327.8 mAh/g） and higher discharge platform, the discharge performance of electrodes depends on both D and Rct, so the kinetics characteristics that electrodes reaction is controlled by both mass-transfer step and charge- transfer step are put forward.
基金Science Foundation of Shandong Province,China(No.Y2001F04)
文摘The feasibility of embedding 40nm ZnO particles into porous textile material by using ultrasonic and its influence factors were studied. Through investigations, it is proved that the higher the concentration of nanoparticle suspension is, the higher the weight of embedding percentage (EPW) is. However, the increasing trend of EPW will minish quickly when the concentration exceeds 1%. In addition, the longer the process time of ultrasonic is, the higher EPW is. EPW is always higher when the distance between film and ultrasonic transducer is 1/2λ and 3/2λ, and lower when the distance is 1λ and 2λ. For 40nm ZnO particles, EPW of the film effected by ultrasonic with the frequency of 42kHz reaches the maximum.
