The article presents the results of research on the possibilities of using genetic algorithms for solving the multicriteria optimization problem of determining the active components of a wind farm.Optimization is carr...The article presents the results of research on the possibilities of using genetic algorithms for solving the multicriteria optimization problem of determining the active components of a wind farm.Optimization is carried out on two parameters:efficiency factor of wind farm use(integrated parameter calculated on the basis of 6 parameters of each of the wind farm),average power deviation level(average difference between the load power and energy generation capabilities of the active wind farm).That was done an analysis of publications on the use of genetic algorithms to solve multicriteria optimization problems.Computer simulations were performed,which allowed us to analyze the obtained statistical data and determine the main optimization indicators.That was carried out a comparative analysis of the obtained results with other methods,such as the dynamic programming method;the dynamic programming method with the general increase of the set loading;the modified dynamic programming method,neural networks.It is established that the average power deviation for the genetic algorithm and for the modified dynamic programming method is located at the same level,33.7 and 28.8 kW,respectively.The average value of the efficiency coefficient of wind turbine used for the genetic algorithm is 2.4%less than for the modified dynamic programming method.However,the time of finding the solution by the genetic algorithm is 3.6 times less than for the modified dynamic programming method.The obtained results provide an opportunity to implement an effective decision support system in energy flow management.展开更多
Green prevention and control management of soil-borne fungal diseases is a hot topic in agriculture,ecology,and the environment.It is an important way to effectively prevent and control soil-borne fungal diseases,solv...Green prevention and control management of soil-borne fungal diseases is a hot topic in agriculture,ecology,and the environment.It is an important way to effectively prevent and control soil-borne fungal diseases,solve soil degradation caused by continuous cropping obstacles,and fulfill the sustainable development of agriculture through revealing the mechanisms of functional substances to develop highly effective soil amendments.Humic acid shows an inhibitory effect on soil-borne pathogenic fungi,such as Fusarium oxysporum,Choanephora cucurbitarum,and Rhizoctonia solani,with the inhibition rate exceeding 80%.The molecular and elemental composition and contents of–COOH,phenolic C,methoxy group C,carboxyl C,aromatic C–O,anomeric C,and other functional groups of humic acid have been inferred to be responsible for its inhibitory effects on pathogenic fungi in previous research.The inhibitory mechanisms mainly include cell physiological morphology,biochemical process reactions,and molecular signal transduction.This review systematically summarizes the chemical structure,fungistatic effects,variable characteristics,and inhibitory mechanisms of humic acid,aiming to provide a theoretical basis for the development of green and efficient prevention and control technologies for soil-borne fungal diseases.展开更多
Activated carbon(AC)is considered to be an excellent adsorbent due to its high specific surface area and various functional groups.AC powders are available in sizes ranging from 44 to 150 μm.Its particle size prevent...Activated carbon(AC)is considered to be an excellent adsorbent due to its high specific surface area and various functional groups.AC powders are available in sizes ranging from 44 to 150 μm.Its particle size prevent its separation from the soil.Therefore,when AC powder is applied to Cd-contaminated soil,it only reduces the bioavailability of Cd and Cd is not necessarily removed but semi-immobilized.Recovery of adsorbent materials from the soil is therefore a preferred soil remediation method.In order to achieve the separation of Cd from soil and the recovery and reuse of AC,a batch of phenolic resin(PR)-carboxymethyl cellulose(CMC)-activated carbon(AC)composite(PCC-800)with uniform particle diameter(diameter 0.8 mm)and high compressive strength was prepared.PCC-800 composites were made of PR/CMC/AC calcined at 800℃ in a certain ratio.The Barrett-Joyner-Halender results showed that the PCC-800 spheres own a mesoporous structure.The compressive strength of PCC-800 pellets was 20.6 N.After first adsorption cycle,total Cd in the soil decreased by 52.18%while bioavailable Cd decreased to 25.68%of the original soil.After three cycles,the recovery rates of PCC-800 were 90.37%and the adsorption regeneration was 72.73%.The PCC-800 immobilized Cd by adsorption,precipitation and complexation reaction.This study demonstrates the potential for developing adsorbents that are both easily separable from soil and highly effective in adsorption.展开更多
To reveal the influence of mechanical activation on the performance of fly ash, the microanalysis（the energy spectroscopy, XRD and SEM）, the distribution size of particle of fly ash and cement paste intensity of var...To reveal the influence of mechanical activation on the performance of fly ash, the microanalysis（the energy spectroscopy, XRD and SEM）, the distribution size of particle of fly ash and cement paste intensity of various age for different grinding time were studied. The relationships of the activity and the composition of fly ash, microstructure and the distribution of particle size by mechanical activation of fly ash were obtained. The internal glass beads with activity were released by grinding fly ash for a certain time. The particle specific surface area was improved and the hydration reaction of the interface and the surface active center was increased by grinding. The granularity distributing of fly-ash trended towards optimization. The polar molecules or ions were easier to intrude into the internal cavity of the vitreous body. The active silica and alumina of fly ash were rapidly depolymerized. Each performance index of fly ash was increased before grinding for 20 min. Cement paste intensity of various age increased along with the grinding time, and the early strength increase range was big, but the later period intensity increase range hastened slightly. The internal part of vitreous of fly ash was destroyed if the fly ash continued to be ground and the activity of fly ash was reduced. It is suggested that Guozhuang＇s fly ash should be ground for 20 min.展开更多
Piezoelectric materials are capable of actuation and sensing and have been used in a wide variety of smart devices and structures.Active fiber composite and macro fiber composite are newly developed types of piezoelec...Piezoelectric materials are capable of actuation and sensing and have been used in a wide variety of smart devices and structures.Active fiber composite and macro fiber composite are newly developed types of piezoelectric composites,and show superior properties to monolithic piezoelectric wafer due to their distinctive structures.Numerous work has focused on the performance prediction of the composites by evaluation of structural parameters and properties of the constituent materials with analytical and numerical methods.Various applications have been explored for the piezoelectric fiber composites,including vibration and noise control,health monitoring,morphing of structures and energy harvesting,in which the composites play key role and demonstrate the necessity for further development.展开更多
The outbreak of COVID-19 has brought great health threat to human beings all over the world,it also brings great challenges to the development of medicine.Several traditional Chinese medicines have good effects on tre...The outbreak of COVID-19 has brought great health threat to human beings all over the world,it also brings great challenges to the development of medicine.Several traditional Chinese medicines have good effects on treating pneumonia patients in COVID-19.In this article,the active composition,pharmacological mechanism and clinical practice of these traditional Chinese medicines were reviewed.This will be of positive significance to the further research and clinical application of traditional Chinese medicine for treating COVID-19 pneumonia.展开更多
The novel visible light-induced carbon nitride（g-C3N4） and Bi VO4 composite photocatalysts were obtained through a simple mixing-calcination method. The physical and photophysical properties of the Bi VO4-g-C3N4 com...The novel visible light-induced carbon nitride（g-C3N4） and Bi VO4 composite photocatalysts were obtained through a simple mixing-calcination method. The physical and photophysical properties of the Bi VO4-g-C3N4 composites were investigated by X-ray diffraction（XRD）, Fourier transform infrared（FTIR） spectroscopy, UV-vis diffuse reflection spectroscopy, high-resolution transmission electron microscopy（HRTEM）, photoluminescent（PL） spectroscopy, and BET surface area measurements. Photocatalytic oxidation ability of the prepared samples was examined by studying the degradation of rhodamine B（Rh B） as a target pollutant under visible-light irradiation. The composite photocatalysts exhibited an enhanced photocatalytic performance in degrading Rh B. The optimal g-C3N4 content of the composite photocatalysts was determined for the photodegradation activity. The improved photocatalytic activity of the as-prepared composite photocatalyst may be attributed to the enhancement of photo-generated electron-hole separation at the interface.展开更多
Nickel coated diamond composite powders were fabricated via a newly developed direct electrodeposition technique. The effects of activators on the coating of diamond were firstly investigated and diamond grinding whee...Nickel coated diamond composite powders were fabricated via a newly developed direct electrodeposition technique. The effects of activators on the coating of diamond were firstly investigated and diamond grinding wheels were then prepared from Ni-coated diamond composite powders with different activators. The microstructural characterizations of this composite powders were finally conducted by scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction, and the mechanical and tribological properties of as-prepared diamond grinding wheels were also measured. There are changes in microstructures and properties of the composite powders with activators. The activator concentration also has an influence on the morphologies and phase structures of the Ni coating on diamond particles.The composite powders with more compact coating of nickel can be prepared by adding 1 g dm^（-3） or more AgNO_3 as an activator to electrodeposit nickel on diamond. The mechanical and tribological properties of diamond grinding wheels were significantly improved when the coating phase structure of Ni crystal grew with（111） plane orientation on the surface of diamond particles. The wheels made from nickel coated diamond composite powders possessed the advantages of easy preparation and outstanding tribological properties. Therefore, Ni coated diamond composite powders exhibit a great potential to be extensively applied in diamond cutting and grinding tools.展开更多
A novel chemical technique combined with unique plasma activated sintering（PAS） was utilized to prepare consolidated copper matrix composites（CMCs） by adding Cu-SnO2-rGO layered micro powders as reinforced fillers...A novel chemical technique combined with unique plasma activated sintering（PAS） was utilized to prepare consolidated copper matrix composites（CMCs） by adding Cu-SnO2-rGO layered micro powders as reinforced fillers into Cu matrix. The repeating Cu-SnO2-rGO structure was composed of inner dispersed reduced graphene oxide（r GO）, SnO2 as intermedia and outer Cu coating. SnO2 was introduced to the surface of rGO sheets in order to prevent the graphene aggregation with SnO2 serving as spacer and to provide enough active sites for subsequent Cu deposition. This process can guarantee rGO sheets to suffi ciently disperse and Cu nanoparticles to tightly and uniformly anchor on each layer of rGO by means of the SnO2 active sites as well as strictly control the reduction speed of Cu^2＋. The complete cover of Cu nanoparticles on rGO sheets thoroughly avoids direct contact among rGO layers. Hence, the repeating structure can simultaneously solve the wettability problem between rGO and Cu matrix as well as improve the bonding strength between rGO and Cu matrix at the well-bonded Cu-SnO2-rGO interface. The isolated rGO can effectively hinder the glide of dislocation at Cu-rGO interface and support the applied loads. Finally, the compressive strength of CMCs was enhanced when the strengthening effi ciency reached up to 41.展开更多
The properties of Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-WC-ZrO2 composite anode for zinc electrowinning were investigated. The electrochemical performance was studied by Tafel polarization curves（Tafel）, e...The properties of Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-WC-ZrO2 composite anode for zinc electrowinning were investigated. The electrochemical performance was studied by Tafel polarization curves（Tafel）, electrochemical impedance spectroscopy（EIS） and corrosion rate obtained in an acidic zinc sulfate electrolyte solution. Scanning electron microscopy（SEM）, X-ray diffraction（XRD）, and energy dispersive X-ray spectroscopy（EDXS） were used to observe the microstructural features of coating. Anodes of Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2, Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-WC, Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-ZrO2, and Pb-1%Ag anodes were also researched. The results indicated that the Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-WC-ZrO2 showed the best catalytic activity and corrosion resistant performance; the intensity of diffraction peak exhibited the highest value as well as a new PbWO4 phase; the content of WC and ZrO2 in coating showed the highest value as well as the finest grain size.展开更多
A series of MoS_2/ZnO compound photocatalysts with different mass ratios were successfully prepared by hydrothermal method. The X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), scanning electron microsco...A series of MoS_2/ZnO compound photocatalysts with different mass ratios were successfully prepared by hydrothermal method. The X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), scanning electron microscope(SEM) and UV-vis absorption were used to characterize the prepared MoS_2/ZnO photocatalysts. It was proved that the combination of Mo S2 and Zn O can increase the content of oxygen vacancies on surface of Zn O, thus improving the light absorption capacity in visible light region and reducing the band gap of Zn O. And the photocatalytic performance of Zn O was improved. Experimental results show that the MoS_2/ZnO(3 wt%) compound has the highest degradation rate for methylene blue(MB) under visible light, which means that it has the best photocatalytic activity among all the prepared samples.展开更多
L-threonine(L-Thr) obtained by fermentation often contains vestigial hydrosoluble Pb(Ⅱ), Fe(Ⅱ), L-glutamic acid(L-Glu) etc., which affect the product quality. Poly melamine and L-aspartic acid(L-Asp) resin functiona...L-threonine(L-Thr) obtained by fermentation often contains vestigial hydrosoluble Pb(Ⅱ), Fe(Ⅱ), L-glutamic acid(L-Glu) etc., which affect the product quality. Poly melamine and L-aspartic acid(L-Asp) resin functional coconut shell activated carbon composite(PMA/AC) was prepared by a pressure relief-dipping-microwave assisted polymerization method for the simultaneous removals. The adsorption capacities of Pb(Ⅱ), Fe(Ⅱ) and L-Glu could reach to 82.34 mg·g^(-1), 57.82 mg·g^(-1) and 102.58 mg·g^(-1) at conditions of pH 5.0, 45 °C and 4 h with an initial concentration of 0.01 mol·L^(-1), respectively. The present PMA/AC was successfully used to the simultaneous removals of vestigial Pb(Ⅱ), Fe(Ⅱ) and L-Glu from the fermented crude product solution of L-Thr. Moreover, the PMA/AC was carefully characterized by FE-SEM, IR et al. analysis techniques, the results show that abundant PMA particles evenly distributed at the inner and outside surface of AC with a size of(50 ± 20) nm.展开更多
Laccase was immobilized on the ceramic-chitosan composite support by using glutaraldehyde as the cross-linking reagent. The immobilization conditions and characterization of the immobilized enzyme were investigated. T...Laccase was immobilized on the ceramic-chitosan composite support by using glutaraldehyde as the cross-linking reagent. The immobilization conditions and characterization of the immobilized enzyme were investigated. The immobilization of laccase was successfully realized when 3.0 mL of 1.25 mg/mL of laccase at a pH value of 4.0 reacted with 0.15 g of ceramic-chitosan composite support(CCCS) at 4 ℃ for 24 h. The immobilized enzyme exhibited a maximum activity at pH 3.0. The optimal temperatures for immobilized enzyme were 25 ℃ and 50 ℃. The K_m value of immobilized laccase for ABTS was 66.64 μmol/L at a pH value of 3.0 at 25 ℃. Compared with free laccase, the thermal, operating and storage stability of immobilized laccase was improved after the immobilization.展开更多
ZrC nanoparticles in the matrix of Fe were produced by the mechanically activated self-propagating hightemperature method using ZrO2/C/Mg/Fe powder mixtures. The effects of milling time, Fe content, and combustion tem...ZrC nanoparticles in the matrix of Fe were produced by the mechanically activated self-propagating hightemperature method using ZrO2/C/Mg/Fe powder mixtures. The effects of milling time, Fe content, and combustion temperature as well as the formation route for synthesizing ZrC powder particles were studied. The samples were characterized by XRD, SEM, TEM, and DTA. The XRD results revealed that, after 18 h of mechanical activation, ZrO2/ZC/Mg/Fe reacted with the self-propagating combustion（SHS） mode at 870 °C producing the ZrC–Fe nanocomposite. It was also found that both mechanical activation and Fe content played key roles in the ZrC synthesis temperature. With a Fe content of（5–40） wt%, the SHS reaction proceeded favorably and both the ZrC formation temperature and the adiabatic temperature（Tad） decreased. The Mg O content was removed from the final products using a leaching test process by dissolving in hydrochloric and acetic acids.展开更多
Pressure activated sealant(PAS),as a novel kind of sealingfluid,can provide rapid and self-adapting repair on the tiny damage of static seals(e.g.,screws and pipelines)while encountering pressure difference of leakage...Pressure activated sealant(PAS),as a novel kind of sealingfluid,can provide rapid and self-adapting repair on the tiny damage of static seals(e.g.,screws and pipelines)while encountering pressure difference of leakage sites,but its sealing property is affected more by the size of leakage site,so it exhibits limited application in the production and wellbore integrity recovery of oil&gas wells.To extend PAS's applicability,this paper put forward a composite PAS technology involving the cooperativity of solid and liquid sealing materials for enhancing large pore plugging based on the phase state transition and sealing behaviors of sealingfluid under differential pressure.In this technology,two types of solid sealing materials(bridging rigid particle and tension reinforcingfiber)were used jointly to modify the geometries of leakage pores and the migration paths offluids,which can promote the formation of effective solid barrier from the PAS tofill in large leaking pores,so as to perform sealing repair.And the following laboratory experimental results were obtained.First,the newly prepared PAS is a kind of polydisperse system,and the core particles are regular in shape with the size distribution mainly in a range of 300e400 mm.Second,in the range of evaluation pressure,sepiolitefiber,as the structure promoter,reinforces the integrity of sealing solids.Third,mussel powder,as the pore structure modifier,improves the retention ability of the sealingfluid in the limited leakage space.These two sealing materials not only cooperatively improve the structure of solid barrier,but also markedly enhance the plugging capability of composite PAS in large pores.In conclusion,these results can provide theoretical and technical support for the development and application of novel multifunctional sealants in oil&gas wells.展开更多
Liquid crystal elastomers are active materials that combine the anisotropic properties of liquid crystals with the elasticity of polymer networks.The LCEs exhibit remarkable reversible contraction and elongation capab...Liquid crystal elastomers are active materials that combine the anisotropic properties of liquid crystals with the elasticity of polymer networks.The LCEs exhibit remarkable reversible contraction and elongation capabilities in response to external stimuli,rendering them highly promising for diverse applications,such as soft robotics,haptic devices,shape morphing structures,etc,However,the predominant reliance on heating as the driving stimulus for LCEs has limited their practical applications.This drawback can be effectively addressed by incorporating fllers,which can generate heat under various stimuli.The recent progress in LCE composites has significantly expanded the application potential of LCEs.In this minireview,we present the design strategies for soft actuators with LCE composites,followed by a detailed exploration of photothermal and electrothermal LCE.composites as prominent examples.Furthermore,we provide an outlook on the challenges and opportunities in the feld of LCE composites.展开更多
A series of carbon nanotubes/TiO2 nanotubes （CNTs/TNTs） composite photocatalysts were successfully prepared by incorporation of CNTs in HNO3 washing process. These photocatalysts were characterized by XRD, N2 physic...A series of carbon nanotubes/TiO2 nanotubes （CNTs/TNTs） composite photocatalysts were successfully prepared by incorporation of CNTs in HNO3 washing process. These photocatalysts were characterized by XRD, N2 physical adsorption, UV-vis diffuse reflectance spectroscopy, TEM and Raman spectroscopy, respectively, and their photocatalytic activities were tested by using methyl orange （MO） as a model compound. Also, the effects of amount of CNTs incorporated, calcination temperature and amount of catalyst on the photocatalytic activity of the composite photocatalyst were systematically investigated. The results show that the CNTs/TNTs composite exhibits much higher photocatalytic activity than that of the TNTs or CNTs alone.展开更多
基金This research was funded by National Research Foundation of Ukraine,Grant Number 2020.01/0025.
文摘The article presents the results of research on the possibilities of using genetic algorithms for solving the multicriteria optimization problem of determining the active components of a wind farm.Optimization is carried out on two parameters:efficiency factor of wind farm use(integrated parameter calculated on the basis of 6 parameters of each of the wind farm),average power deviation level(average difference between the load power and energy generation capabilities of the active wind farm).That was done an analysis of publications on the use of genetic algorithms to solve multicriteria optimization problems.Computer simulations were performed,which allowed us to analyze the obtained statistical data and determine the main optimization indicators.That was carried out a comparative analysis of the obtained results with other methods,such as the dynamic programming method;the dynamic programming method with the general increase of the set loading;the modified dynamic programming method,neural networks.It is established that the average power deviation for the genetic algorithm and for the modified dynamic programming method is located at the same level,33.7 and 28.8 kW,respectively.The average value of the efficiency coefficient of wind turbine used for the genetic algorithm is 2.4%less than for the modified dynamic programming method.However,the time of finding the solution by the genetic algorithm is 3.6 times less than for the modified dynamic programming method.The obtained results provide an opportunity to implement an effective decision support system in energy flow management.
基金supported by the National Natural Science Foundation of China(Nos.42207371 and 32071642)the Scientific Project of Jiangsu Vocational College of Agriculture and Forestry,China(No.2021kj17)the Key Research Projects of Jiangsu Vocational College of Agriculture and Forestry,China(No.2023kj14)。
文摘Green prevention and control management of soil-borne fungal diseases is a hot topic in agriculture,ecology,and the environment.It is an important way to effectively prevent and control soil-borne fungal diseases,solve soil degradation caused by continuous cropping obstacles,and fulfill the sustainable development of agriculture through revealing the mechanisms of functional substances to develop highly effective soil amendments.Humic acid shows an inhibitory effect on soil-borne pathogenic fungi,such as Fusarium oxysporum,Choanephora cucurbitarum,and Rhizoctonia solani,with the inhibition rate exceeding 80%.The molecular and elemental composition and contents of–COOH,phenolic C,methoxy group C,carboxyl C,aromatic C–O,anomeric C,and other functional groups of humic acid have been inferred to be responsible for its inhibitory effects on pathogenic fungi in previous research.The inhibitory mechanisms mainly include cell physiological morphology,biochemical process reactions,and molecular signal transduction.This review systematically summarizes the chemical structure,fungistatic effects,variable characteristics,and inhibitory mechanisms of humic acid,aiming to provide a theoretical basis for the development of green and efficient prevention and control technologies for soil-borne fungal diseases.
文摘Activated carbon(AC)is considered to be an excellent adsorbent due to its high specific surface area and various functional groups.AC powders are available in sizes ranging from 44 to 150 μm.Its particle size prevent its separation from the soil.Therefore,when AC powder is applied to Cd-contaminated soil,it only reduces the bioavailability of Cd and Cd is not necessarily removed but semi-immobilized.Recovery of adsorbent materials from the soil is therefore a preferred soil remediation method.In order to achieve the separation of Cd from soil and the recovery and reuse of AC,a batch of phenolic resin(PR)-carboxymethyl cellulose(CMC)-activated carbon(AC)composite(PCC-800)with uniform particle diameter(diameter 0.8 mm)and high compressive strength was prepared.PCC-800 composites were made of PR/CMC/AC calcined at 800℃ in a certain ratio.The Barrett-Joyner-Halender results showed that the PCC-800 spheres own a mesoporous structure.The compressive strength of PCC-800 pellets was 20.6 N.After first adsorption cycle,total Cd in the soil decreased by 52.18%while bioavailable Cd decreased to 25.68%of the original soil.After three cycles,the recovery rates of PCC-800 were 90.37%and the adsorption regeneration was 72.73%.The PCC-800 immobilized Cd by adsorption,precipitation and complexation reaction.This study demonstrates the potential for developing adsorbents that are both easily separable from soil and highly effective in adsorption.
基金Funded by the National Natural Science Foundation of China(No.51574055)
文摘To reveal the influence of mechanical activation on the performance of fly ash, the microanalysis（the energy spectroscopy, XRD and SEM）, the distribution size of particle of fly ash and cement paste intensity of various age for different grinding time were studied. The relationships of the activity and the composition of fly ash, microstructure and the distribution of particle size by mechanical activation of fly ash were obtained. The internal glass beads with activity were released by grinding fly ash for a certain time. The particle specific surface area was improved and the hydration reaction of the interface and the surface active center was increased by grinding. The granularity distributing of fly-ash trended towards optimization. The polar molecules or ions were easier to intrude into the internal cavity of the vitreous body. The active silica and alumina of fly ash were rapidly depolymerized. Each performance index of fly ash was increased before grinding for 20 min. Cement paste intensity of various age increased along with the grinding time, and the early strength increase range was big, but the later period intensity increase range hastened slightly. The internal part of vitreous of fly ash was destroyed if the fly ash continued to be ground and the activity of fly ash was reduced. It is suggested that Guozhuang＇s fly ash should be ground for 20 min.
基金Project(51072235) supported by the National Natural Science Foundation of ChinaProject(11JJ1008) supported by the Natural Science Foundation of Hunan Province,China+2 种基金Project(20110162110044) supported by the PhD Program Foundation of Ministry of Education of ChinaProject(7433001207) supported by Hunan Provincial Innovation Foundation for Postgraduate,ChinaProject(2001JF3215) supported by Hunan Provincial Science and Technology Plan,China
文摘Piezoelectric materials are capable of actuation and sensing and have been used in a wide variety of smart devices and structures.Active fiber composite and macro fiber composite are newly developed types of piezoelectric composites,and show superior properties to monolithic piezoelectric wafer due to their distinctive structures.Numerous work has focused on the performance prediction of the composites by evaluation of structural parameters and properties of the constituent materials with analytical and numerical methods.Various applications have been explored for the piezoelectric fiber composites,including vibration and noise control,health monitoring,morphing of structures and energy harvesting,in which the composites play key role and demonstrate the necessity for further development.
文摘The outbreak of COVID-19 has brought great health threat to human beings all over the world,it also brings great challenges to the development of medicine.Several traditional Chinese medicines have good effects on treating pneumonia patients in COVID-19.In this article,the active composition,pharmacological mechanism and clinical practice of these traditional Chinese medicines were reviewed.This will be of positive significance to the further research and clinical application of traditional Chinese medicine for treating COVID-19 pneumonia.
基金Funded by the National Natural Science Foundation of China(No.51208102)
文摘The novel visible light-induced carbon nitride（g-C3N4） and Bi VO4 composite photocatalysts were obtained through a simple mixing-calcination method. The physical and photophysical properties of the Bi VO4-g-C3N4 composites were investigated by X-ray diffraction（XRD）, Fourier transform infrared（FTIR） spectroscopy, UV-vis diffuse reflection spectroscopy, high-resolution transmission electron microscopy（HRTEM）, photoluminescent（PL） spectroscopy, and BET surface area measurements. Photocatalytic oxidation ability of the prepared samples was examined by studying the degradation of rhodamine B（Rh B） as a target pollutant under visible-light irradiation. The composite photocatalysts exhibited an enhanced photocatalytic performance in degrading Rh B. The optimal g-C3N4 content of the composite photocatalysts was determined for the photodegradation activity. The improved photocatalytic activity of the as-prepared composite photocatalyst may be attributed to the enhancement of photo-generated electron-hole separation at the interface.
基金funded by the National Natural Science Foundation of China (Nos. 21476066 and 51271074)
文摘Nickel coated diamond composite powders were fabricated via a newly developed direct electrodeposition technique. The effects of activators on the coating of diamond were firstly investigated and diamond grinding wheels were then prepared from Ni-coated diamond composite powders with different activators. The microstructural characterizations of this composite powders were finally conducted by scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction, and the mechanical and tribological properties of as-prepared diamond grinding wheels were also measured. There are changes in microstructures and properties of the composite powders with activators. The activator concentration also has an influence on the morphologies and phase structures of the Ni coating on diamond particles.The composite powders with more compact coating of nickel can be prepared by adding 1 g dm^（-3） or more AgNO_3 as an activator to electrodeposit nickel on diamond. The mechanical and tribological properties of diamond grinding wheels were significantly improved when the coating phase structure of Ni crystal grew with（111） plane orientation on the surface of diamond particles. The wheels made from nickel coated diamond composite powders possessed the advantages of easy preparation and outstanding tribological properties. Therefore, Ni coated diamond composite powders exhibit a great potential to be extensively applied in diamond cutting and grinding tools.
基金Funded by the National Natural Science Foundation of China(51572208)the 111 Project(B13035)+1 种基金the National Natural Science Foundation of Hubei Province(2014CFB257 and 2014CFB258)the Fundamental Research Funds for the Central Universities(WUT:2015-III-059)
文摘A novel chemical technique combined with unique plasma activated sintering（PAS） was utilized to prepare consolidated copper matrix composites（CMCs） by adding Cu-SnO2-rGO layered micro powders as reinforced fillers into Cu matrix. The repeating Cu-SnO2-rGO structure was composed of inner dispersed reduced graphene oxide（r GO）, SnO2 as intermedia and outer Cu coating. SnO2 was introduced to the surface of rGO sheets in order to prevent the graphene aggregation with SnO2 serving as spacer and to provide enough active sites for subsequent Cu deposition. This process can guarantee rGO sheets to suffi ciently disperse and Cu nanoparticles to tightly and uniformly anchor on each layer of rGO by means of the SnO2 active sites as well as strictly control the reduction speed of Cu^2＋. The complete cover of Cu nanoparticles on rGO sheets thoroughly avoids direct contact among rGO layers. Hence, the repeating structure can simultaneously solve the wettability problem between rGO and Cu matrix as well as improve the bonding strength between rGO and Cu matrix at the well-bonded Cu-SnO2-rGO interface. The isolated rGO can effectively hinder the glide of dislocation at Cu-rGO interface and support the applied loads. Finally, the compressive strength of CMCs was enhanced when the strengthening effi ciency reached up to 41.
基金Funded by the National Natural Science Foundation of China(Nos.51564029,51504111,51504231,51364019)the Key Project of Yunnan Province Applied Basic Research Plan of China(No.2014FA024)
文摘The properties of Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-WC-ZrO2 composite anode for zinc electrowinning were investigated. The electrochemical performance was studied by Tafel polarization curves（Tafel）, electrochemical impedance spectroscopy（EIS） and corrosion rate obtained in an acidic zinc sulfate electrolyte solution. Scanning electron microscopy（SEM）, X-ray diffraction（XRD）, and energy dispersive X-ray spectroscopy（EDXS） were used to observe the microstructural features of coating. Anodes of Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2, Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-WC, Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-ZrO2, and Pb-1%Ag anodes were also researched. The results indicated that the Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-WC-ZrO2 showed the best catalytic activity and corrosion resistant performance; the intensity of diffraction peak exhibited the highest value as well as a new PbWO4 phase; the content of WC and ZrO2 in coating showed the highest value as well as the finest grain size.
基金supported by the Xinjiang Science and Technology Project (No.2019D01C036)。
文摘A series of MoS_2/ZnO compound photocatalysts with different mass ratios were successfully prepared by hydrothermal method. The X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), scanning electron microscope(SEM) and UV-vis absorption were used to characterize the prepared MoS_2/ZnO photocatalysts. It was proved that the combination of Mo S2 and Zn O can increase the content of oxygen vacancies on surface of Zn O, thus improving the light absorption capacity in visible light region and reducing the band gap of Zn O. And the photocatalytic performance of Zn O was improved. Experimental results show that the MoS_2/ZnO(3 wt%) compound has the highest degradation rate for methylene blue(MB) under visible light, which means that it has the best photocatalytic activity among all the prepared samples.
基金Supported by the National Natural Science Foundation of China(U1407110)2014 Special Funds of Guangdong Province for Collaborative Innovation and Environment Platform Construction,Public Research and Capacity Building(2014B090901010)
文摘L-threonine(L-Thr) obtained by fermentation often contains vestigial hydrosoluble Pb(Ⅱ), Fe(Ⅱ), L-glutamic acid(L-Glu) etc., which affect the product quality. Poly melamine and L-aspartic acid(L-Asp) resin functional coconut shell activated carbon composite(PMA/AC) was prepared by a pressure relief-dipping-microwave assisted polymerization method for the simultaneous removals. The adsorption capacities of Pb(Ⅱ), Fe(Ⅱ) and L-Glu could reach to 82.34 mg·g^(-1), 57.82 mg·g^(-1) and 102.58 mg·g^(-1) at conditions of pH 5.0, 45 °C and 4 h with an initial concentration of 0.01 mol·L^(-1), respectively. The present PMA/AC was successfully used to the simultaneous removals of vestigial Pb(Ⅱ), Fe(Ⅱ) and L-Glu from the fermented crude product solution of L-Thr. Moreover, the PMA/AC was carefully characterized by FE-SEM, IR et al. analysis techniques, the results show that abundant PMA particles evenly distributed at the inner and outside surface of AC with a size of(50 ± 20) nm.
文摘Laccase was immobilized on the ceramic-chitosan composite support by using glutaraldehyde as the cross-linking reagent. The immobilization conditions and characterization of the immobilized enzyme were investigated. The immobilization of laccase was successfully realized when 3.0 mL of 1.25 mg/mL of laccase at a pH value of 4.0 reacted with 0.15 g of ceramic-chitosan composite support(CCCS) at 4 ℃ for 24 h. The immobilized enzyme exhibited a maximum activity at pH 3.0. The optimal temperatures for immobilized enzyme were 25 ℃ and 50 ℃. The K_m value of immobilized laccase for ABTS was 66.64 μmol/L at a pH value of 3.0 at 25 ℃. Compared with free laccase, the thermal, operating and storage stability of immobilized laccase was improved after the immobilization.
文摘ZrC nanoparticles in the matrix of Fe were produced by the mechanically activated self-propagating hightemperature method using ZrO2/C/Mg/Fe powder mixtures. The effects of milling time, Fe content, and combustion temperature as well as the formation route for synthesizing ZrC powder particles were studied. The samples were characterized by XRD, SEM, TEM, and DTA. The XRD results revealed that, after 18 h of mechanical activation, ZrO2/ZC/Mg/Fe reacted with the self-propagating combustion（SHS） mode at 870 °C producing the ZrC–Fe nanocomposite. It was also found that both mechanical activation and Fe content played key roles in the ZrC synthesis temperature. With a Fe content of（5–40） wt%, the SHS reaction proceeded favorably and both the ZrC formation temperature and the adiabatic temperature（Tad） decreased. The Mg O content was removed from the final products using a leaching test process by dissolving in hydrochloric and acetic acids.
基金supported by the National Science and Technology Major Project".Drilling fluid and cementing technicalrescarch for shale gas horizontal wells"(No.:2016ZX05060-015)Welfare Technology Reseach Project of Zhejiang Province"Pressure activated sealant(PAS)for the tiny leakage in the offshore oil and gas development and its self-adapting repair mechanism research"(No.:LGG20E040002)+2 种基金Scientific Rescarch Project of Education Department of Zhejiang Province"Self-adapting repair behavior research for the tiny damage of the new-type pressure activated scalant(PAS)(No.:Y201840431)Zhoushan Science and Technology Plan Project"Pressure controlled-release targeted repair technology rescarch for the sealingHlamage of offshore oil and gas wells"(No:2019C21006)Innovative Program of Zhejiang Occan University"Self-adapting plugging agent for oil and gas pipelines and its action mechanism"(No.XJ2018082).
文摘Pressure activated sealant(PAS),as a novel kind of sealingfluid,can provide rapid and self-adapting repair on the tiny damage of static seals(e.g.,screws and pipelines)while encountering pressure difference of leakage sites,but its sealing property is affected more by the size of leakage site,so it exhibits limited application in the production and wellbore integrity recovery of oil&gas wells.To extend PAS's applicability,this paper put forward a composite PAS technology involving the cooperativity of solid and liquid sealing materials for enhancing large pore plugging based on the phase state transition and sealing behaviors of sealingfluid under differential pressure.In this technology,two types of solid sealing materials(bridging rigid particle and tension reinforcingfiber)were used jointly to modify the geometries of leakage pores and the migration paths offluids,which can promote the formation of effective solid barrier from the PAS tofill in large leaking pores,so as to perform sealing repair.And the following laboratory experimental results were obtained.First,the newly prepared PAS is a kind of polydisperse system,and the core particles are regular in shape with the size distribution mainly in a range of 300e400 mm.Second,in the range of evaluation pressure,sepiolitefiber,as the structure promoter,reinforces the integrity of sealing solids.Third,mussel powder,as the pore structure modifier,improves the retention ability of the sealingfluid in the limited leakage space.These two sealing materials not only cooperatively improve the structure of solid barrier,but also markedly enhance the plugging capability of composite PAS in large pores.In conclusion,these results can provide theoretical and technical support for the development and application of novel multifunctional sealants in oil&gas wells.
基金supported by the Fundamental Research Funds for the Central Universities[YWF-22-K-101]National Natural Science Foundation of China[12202120]Science Technology and Innovation Program of Shenzhen[JCYJ20220531095210022].
文摘Liquid crystal elastomers are active materials that combine the anisotropic properties of liquid crystals with the elasticity of polymer networks.The LCEs exhibit remarkable reversible contraction and elongation capabilities in response to external stimuli,rendering them highly promising for diverse applications,such as soft robotics,haptic devices,shape morphing structures,etc,However,the predominant reliance on heating as the driving stimulus for LCEs has limited their practical applications.This drawback can be effectively addressed by incorporating fllers,which can generate heat under various stimuli.The recent progress in LCE composites has significantly expanded the application potential of LCEs.In this minireview,we present the design strategies for soft actuators with LCE composites,followed by a detailed exploration of photothermal and electrothermal LCE.composites as prominent examples.Furthermore,we provide an outlook on the challenges and opportunities in the feld of LCE composites.
基金Financial supports from the Project Supported by the Natural Science Foundation of the Jiangsu Province Higher Education Institutions of China(09KJD150002)Project Supported by the Graduate Innovation Program Foundation of the Jiangsu Province Higher Education Institutions of China(CXLX_0570)
文摘A series of carbon nanotubes/TiO2 nanotubes （CNTs/TNTs） composite photocatalysts were successfully prepared by incorporation of CNTs in HNO3 washing process. These photocatalysts were characterized by XRD, N2 physical adsorption, UV-vis diffuse reflectance spectroscopy, TEM and Raman spectroscopy, respectively, and their photocatalytic activities were tested by using methyl orange （MO） as a model compound. Also, the effects of amount of CNTs incorporated, calcination temperature and amount of catalyst on the photocatalytic activity of the composite photocatalyst were systematically investigated. The results show that the CNTs/TNTs composite exhibits much higher photocatalytic activity than that of the TNTs or CNTs alone.
