Calcium carboaluminate was successfully prepared by a simple and efficient one-step method,and the effects of temperature,time,raw material ratio,carbonate type and heavy CaCO_(3)particle size on the products were inv...Calcium carboaluminate was successfully prepared by a simple and efficient one-step method,and the effects of temperature,time,raw material ratio,carbonate type and heavy CaCO_(3)particle size on the products were investigated in detail.The results show that increasing the temperature and extending the reaction time can enhance the yield and crystallisation degree of calcium carboaluminate.The proportion of Ca(OH)_(2),Al(OH)_(3)and CaCO_(3)is a pivotal factor in the synthesis of calcium carboaluminate.When the ratio of Ca(OH)_(2),Al(OH)_(3)and CaCO_(3)is 3:2:1,the diffraction peaks of calcium carboaluminate in the products are relatively sharp and strong.Furthermore,the purity and crystallinity of the synthesized calcium carboaluminate are higher when heavy CaCO_(3)with the particle size of 120 mesh is used as the carbonate raw material,in comparison to CO_(2),Na_(2)CO_(3)and light CaCO_(3).As results,a simple and efficient method for the synthesis of calcium carboaluminate is proposed,which will provide a solid experimental foundation and technical support for the industrial application of calcium carboaluminate in marine concrete.展开更多
The optimal condition for a one-step process removing organic compounds from coking wastewater by simultaneously synthesized organobentonite as a pretreatment was investigated.Results showed that sorption of organic c...The optimal condition for a one-step process removing organic compounds from coking wastewater by simultaneously synthesized organobentonite as a pretreatment was investigated.Results showed that sorption of organic compounds by organobentonite was positively correlated to the cation surfactant exchange on the bentonite and the octanol-water partition coefficient（Kow） of the solutes.With 0.75 g/L bentonite and 180 mg/L（60% of bentonite cation exchange capacity） cetyltrimethylammonium bromide,the removal efficiencies of the 16 polycyclic aromatic hydrocarbon（PAHs） specified by the US Environmental Protection Agency in coking wastewater except naphthalene were more than 90%,and that of benzo（a）pyrene was 99.5%.At the same time,the removal efficiencies of CODCr,NH3-N,volatile phenols,colour and turbidity were 28.6%,13.2%,8.9%,55% and 84.3%,respectively,and the ratio of BOD5/CODCr increased from 0.31 to 0.41.These results indicated that the one-step process had high removal efficiency for toxic and refractory hydrophobic organic compounds,and could improve the biodegradability of the coking wastewater.Therefore it could be a promising technology for the pretreatment of toxic and refractory organic wastewater.展开更多
Formation of super-hydrophobic and corrosion-resistant coatings can provide significant corrosion protection to magnesium alloys.However,it remains a grand challenge to produce such coatings for magnesium-lithium allo...Formation of super-hydrophobic and corrosion-resistant coatings can provide significant corrosion protection to magnesium alloys.However,it remains a grand challenge to produce such coatings for magnesium-lithium alloys due to their high chemical reactivity.Herein,a one-step hydrothermal processing was developed using a stearic-acid-based precursor medium,which enables the hydrothermal conversion and the formation of low surface energy materials concurrently to produce the super-hydrophobic and corrosion-resistant coating.The multiscale microstructures with nanoscale stacks and microscale spheres on the surface,as well as the through-thickness stearates,lead to the super-hydrophobicity and excellent corrosion resistance of the obtained coating.展开更多
This work presents a method to solve the weak solubility of zinc chloride(ZnCl_2) in the ethanol by adding some reasonable water into an ethanol electrolyte containing ZnCl_2 and myristic acid(CH_3(CH_2)_(12)COOH).A r...This work presents a method to solve the weak solubility of zinc chloride(ZnCl_2) in the ethanol by adding some reasonable water into an ethanol electrolyte containing ZnCl_2 and myristic acid(CH_3(CH_2)_(12)COOH).A rapid one-step electrodeposition process was developed to fabricate anodic(2.5 min) and cathodic(40 s) superhydrophobic surfaces of copper substrate(contact angle more than 150°) in an aqueous ethanol electrolyte.Morphology,composition,chemical structure and superhydrophobicity of these superhydrophobic surfaces were investigated by SEM,FTIR,XRD,and contact angle measurement,respectively.The results indicate that water ratio of the electrolyte can reduce the required deposition time,superhydrophobic surface needs over 30 min with anhydrous electrolyte,while it needs only 2.5 min with electrolyte including 10 mL water,and the maximum contact angle of anodic surface is 166° and that of the cathodic surface is 168°.Two copper electrode surfaces have different reactions in the process of electrodeposition time,and the anodic copper surface covers copper myristate(Cu[CH_3(CH_2)_(12)COO]_2) and cupric chloride(CuCl);while,zinc myristate(Zn[CH_3(CH_2)_(12)COO]_2) and pure zinc(Zn) appear on the cathodic surface.展开更多
By theoretical analysis of heat transfer during the "one-step" directional solidification process, the functional relation between the temperature in solid-liquid interface and its effect factor was studied....By theoretical analysis of heat transfer during the "one-step" directional solidification process, the functional relation between the temperature in solid-liquid interface and its effect factor was studied. The thermal gradient in solid liquid interface and heat transfer coefficient between the samples and surroundings were also calculated. On the basis of the above analysis, some suggestions for improving the thermal gradient in solid-liquid interface were put forward. It will provide a theoretical instruction for preparing high performance giant magnetostrictive materials (GMM).展开更多
ε-Caprolactam（CL or CPL） is one of the most important intermediates used in polymer industry for the production of several million tons of nylon-6 every year^[1]. All current commercial processes for the production...ε-Caprolactam（CL or CPL） is one of the most important intermediates used in polymer industry for the production of several million tons of nylon-6 every year^[1]. All current commercial processes for the production of caprolactam are based on either benzene or tolueneI21. Caprolactam is synthesized by the Beckmann rearrangement of cyclohexanone oxime with fuming sulfuric acid or sulfuric acid as the reaction medium, and cyclohexanone oxime is produced by the reaction between cyclohexanone and hydro- xylamine（only one exception is the Toray PNC process）.展开更多
For aircraft manufacturing industries, the analyses and prediction of part machining error during machining process are very important to control and improve part machining quality. In order to effectively control mac...For aircraft manufacturing industries, the analyses and prediction of part machining error during machining process are very important to control and improve part machining quality. In order to effectively control machining error, the method of integrating multivariate statistical process control （MSPC） and stream of variations （SoV） is proposed. Firstly, machining error is modeled by multi-operation approaches for part machining process. SoV is adopted to establish the mathematic model of the relationship between the error of upstream operations and the error of downstream operations. Here error sources not only include the influence of upstream operations but also include many of other error sources. The standard model and the predicted model about SoV are built respectively by whether the operation is done or not to satisfy different requests during part machining process. Secondly, the method of one-step ahead forecast error （OSFE） is used to eliminate autocorrelativity of the sample data from the SoV model, and the T2 control chart in MSPC is built to realize machining error detection according to the data characteristics of the above error model, which can judge whether the operation is out of control or not. If it is, then feedback is sent to the operations. The error model is modified by adjusting the operation out of control, and continually it is used to monitor operations. Finally, a machining instance containing two operations demonstrates the effectiveness of the machining error control method presented in this paper.展开更多
AB2-type-prepolymerized monomer was rapidly （2 h） prepared at room temperature （25 ℃） using commercially available maleic anhydride （MA） and diethanolamine （DEA） as raw materials. By employing toluene-p-sulfo...AB2-type-prepolymerized monomer was rapidly （2 h） prepared at room temperature （25 ℃） using commercially available maleic anhydride （MA） and diethanolamine （DEA） as raw materials. By employing toluene-p-sulfonic acid as a catalyzer, a series of hyperbranched poly（amide-ester） （HBPAE） were successfully synthesized from prepared AB2 monomer by solution condensation polymerization through ＂one-step process＂ or ＂pseudo one-step process＂ （using pentaerythritol as a center core）. The processes were carried out at high temperature of 120 ℃ for 6 h in air atmosphere （inert protection free） with reduced pressure distillation （0.08--0.096 MPa）. The results of FT-IR, UV-Vis, TGA, and intrinsic viscosity testing by Ubbelodhe viscometer showed that the prepared HBPAEs possess three-dimensional configuration with unsaturated conjugate structure, large numbers of branches and numerous terminal hydroxyl groups. These result in their low viscosity, high solubility and thermal stability.展开更多
This paper introduces a new kind of seasonal fractional autoregressive process(SFAR)driven by fractional Gaussian noise(fGn).The new model includes a standard seasonal AR model and fGn.The estimation of the parameters...This paper introduces a new kind of seasonal fractional autoregressive process(SFAR)driven by fractional Gaussian noise(fGn).The new model includes a standard seasonal AR model and fGn.The estimation of the parameters of this new model has to solve two problems:nonstationarity from the seasonal structure and long memory from fGn.We innovatively solve these by getting a stationary subsequence,making a stationary additive sequence and then obtaining their spectral density.Then we use one-step procedure for Generalized Least Squares Estimator(GLSE)and the Geweke Porter–Hudak(GPH)method to get better results.We prove that both the initial and one-step estimators are consistent and asymptotically normal.Finally,we use Monte Carlo simulations with finite-sized samples to demonstrate the performance of these estimators.Moreover,through empirical analysis,it is shown that the SFAR model can simulate some real-world phenomena better than general models.展开更多
In this study,micro/nanostructures are fabricated on the surface of 3Cr13 stainless steel via laser etching,and a superhydrophobic coating with silver nanoparticles(AgNPs)is prepared by utilizing the reduction–adsorp...In this study,micro/nanostructures are fabricated on the surface of 3Cr13 stainless steel via laser etching,and a superhydrophobic coating with silver nanoparticles(AgNPs)is prepared by utilizing the reduction–adsorption properties of polydopamine(PDA).We investigate the effect of soaking time from the“one-step method”on the reduction of nano-Ag,surface wettability,and antibacterial properties.Scanning electron microscopy is performed to analyze the distribution of nano-Ag on the surface,whereas X-ray energy dispersive spectroscopy and X-ray photoelectron spectroscopy are used to analyze the crystal structures and chemical compositions of different surfaces.Samples deposited with PDA on their surface are soaked in a 1H,1H,2H,2H-perfluorodecyltriethoxysilane water–alcohol solution containing AgNO3 for 3 h.Subsequently,a“one-step method”is used to prepare low-adhesion superhydrophobic surfaces containing AgNPs.As immersion progresses,more AgNPs are deposited onto the surface.Compared with the polished surface,the samples prepared via the“one-step method”show significant antibacterial properties against both gram-negative Escherichia coli and gram-positive Staphylococcus aureus.The antibacterial properties of the surface improve as immersion progresses.展开更多
It is well-known that the performance of BiFeO3eBaTiO3(BF-BT)ceramics is sensitive to composition,calcining and sintering temperature(Tcal and Tsint)due to the formation of Bi25FeO39 and/or Bi2Fe4O9 impurities and/or ...It is well-known that the performance of BiFeO3eBaTiO3(BF-BT)ceramics is sensitive to composition,calcining and sintering temperature(Tcal and Tsint)due to the formation of Bi25FeO39 and/or Bi2Fe4O9 impurities and/or the volatilization of Bi_(2)O_(3).We report remarkably stable electrical properties over the range of0.03≤x≤0.05 and 930℃≤Tsint≤970C in 0.7Bi(1þx)FeO_(3)-0.3BaTiO_(3)ceramics prepared by one-step process.This method avoids the thermodynamically unstable region of BiFeO_(3)and prevents the formation of Bi25FeO39 and/or Bi_(2)Fe_(4)O_(9)impurities even when the addition of a-Bi_(2)O_(3)raw material is intentionally deficient or rich to make off-stoichiometric BF-BT,thus greatly improving the robustness of compositional and processing.Rhombohedral-pseudocubic phase coexists in all ceramics,and their CR/CPC fraction are 48.0/52.0e50.6/49.4 and 55.9/44.1e56.6/43.4 when x increases from0.05≤x≤0 to 0.01≤x≤0.05.The stable electrical properties of d33¼180e205 pC/N,Pr¼17.9e23.8 mC/cm^(2),and TC¼485e518℃are achieved.The maximum d_(33T)/d_(33RT)of BF-BT is twice that of soft PZT,superior to most the-state-of-art lead-free ceramics.Our results provide a synthesis strategy for designing high performance piezoelectric materials with good stability and easy industrialization.展开更多
Aqueous zinc-ion batteries provide a most promising alternative to the existing lithium-ion batteries due to their high theoretical capacity,intrinsic safety,and low cost.However,commercializing aqueous zinc-ion batte...Aqueous zinc-ion batteries provide a most promising alternative to the existing lithium-ion batteries due to their high theoretical capacity,intrinsic safety,and low cost.However,commercializing aqueous zinc-ion batteries suffer from dendritic growth and side reactions on the surface of metallic zinc,resulting in poor reversibility.To overcome this critical challenge,here,we report a one-step ultrafast laser processing method for fabricating three-dimensional micro-/nanostructures on zinc anodes to optimize zinc nucleation and deposition processes.It is demonstrated that the three-dimensional micro-/nanostructure with increased specific surface area significantly reduces nucleation overpotential,as well as preferentially absorbs zinc ions to prevent dendritic protuberances and corrosion.As a result,the presence of threedimensional micro-/nanostructures on the zinc metal delivers stable zinc plating/stripping beyond 2500 h(2 mA cm-2/1 mAh cm-2)in symmetric cells,a high Coulombic efficiency(99.71%)in half cells,and moreover an improved capacity retention(71.8%)is also observed in full cells.Equally intriguingly,the pouch cell with three-dimensional micro-/nanostructures can operate across various bending states without severely compromising performance.This work provides an effective strategy to construct ultrafine and high-precision three-dimensional micro-/nanostructures achieving highperformance zinc metal anodes and is expected to be of immediate benefit to other metal-based electrodes.展开更多
Bandgap engineering of semiconductor nanowires or nanoribbons(NRs)offers a promising material foundation for multifunctional integrated optoelectronic devices and circuits.Among these materials,all-inorganic halide pe...Bandgap engineering of semiconductor nanowires or nanoribbons(NRs)offers a promising material foundation for multifunctional integrated optoelectronic devices and circuits.Among these materials,all-inorganic halide perovskites have emerged as a leading candidate for next-generation photoelectronic applications due to their outstanding optoelectronic properties.In this work,we report the direct synthesis of high-quality bandgap gradient lead halide perovskite(CsPbCl_(3−3x)Br_(3x)and CsPbBr_(3−3x)I_(3x)(x=0-1))NRs using a magnetic-pulling source-moving chemical-vapor-deposition(CVD)method.Microstructural characterizations reveal that these as-grown NRs possess high-quality single crystalline structures with continuously tunable compositions.The photoluminescence emissions of these perovskite NRs can be finely tuned across the entire visible spectrum(417-702 nm).Furthermore,photodetectors based on these perovskite NRs demonstrate exceptional photoelectric performance,including a high I_(ON)/I_(OFF)ratio(10^(4)),superior responsivity(37.5 A/W),and remarkable detectivity(2.81×10^(13)Jones).A spatially resolved imaging sensor based on these perovskite NRs is also demonstrated,indicating promising applications in photoelectronic imaging circuits.These bandgap-tunable perovskite NRs provide a versatile materials platform for future integrated devices in electronics and optoelectronics.展开更多
1 Results Control of dispersion in synthesized nano-size powders is crucial to the realization of nanoparticles application,such as the fabrication of functional nano-strucured bodies.Dispersion of plasma-synthesized ...1 Results Control of dispersion in synthesized nano-size powders is crucial to the realization of nanoparticles application,such as the fabrication of functional nano-strucured bodies.Dispersion of plasma-synthesized TiO2 nanoparticles,which are formed in-flight in the high temperature thermal plasma,should be superior to those prepared by ordinal wet processes,as the particles have no surface residual groups.RF thermal plasma is characterized by extremely high temperatures,and rapid heating and cooling...展开更多
基金Funded by the National Nature Science Foundation of China(No.52078321)。
文摘Calcium carboaluminate was successfully prepared by a simple and efficient one-step method,and the effects of temperature,time,raw material ratio,carbonate type and heavy CaCO_(3)particle size on the products were investigated in detail.The results show that increasing the temperature and extending the reaction time can enhance the yield and crystallisation degree of calcium carboaluminate.The proportion of Ca(OH)_(2),Al(OH)_(3)and CaCO_(3)is a pivotal factor in the synthesis of calcium carboaluminate.When the ratio of Ca(OH)_(2),Al(OH)_(3)and CaCO_(3)is 3:2:1,the diffraction peaks of calcium carboaluminate in the products are relatively sharp and strong.Furthermore,the purity and crystallinity of the synthesized calcium carboaluminate are higher when heavy CaCO_(3)with the particle size of 120 mesh is used as the carbonate raw material,in comparison to CO_(2),Na_(2)CO_(3)and light CaCO_(3).As results,a simple and efficient method for the synthesis of calcium carboaluminate is proposed,which will provide a solid experimental foundation and technical support for the industrial application of calcium carboaluminate in marine concrete.
基金supported by the National Natural Science Foundation of China (No. 20890111)
文摘The optimal condition for a one-step process removing organic compounds from coking wastewater by simultaneously synthesized organobentonite as a pretreatment was investigated.Results showed that sorption of organic compounds by organobentonite was positively correlated to the cation surfactant exchange on the bentonite and the octanol-water partition coefficient（Kow） of the solutes.With 0.75 g/L bentonite and 180 mg/L（60% of bentonite cation exchange capacity） cetyltrimethylammonium bromide,the removal efficiencies of the 16 polycyclic aromatic hydrocarbon（PAHs） specified by the US Environmental Protection Agency in coking wastewater except naphthalene were more than 90%,and that of benzo（a）pyrene was 99.5%.At the same time,the removal efficiencies of CODCr,NH3-N,volatile phenols,colour and turbidity were 28.6%,13.2%,8.9%,55% and 84.3%,respectively,and the ratio of BOD5/CODCr increased from 0.31 to 0.41.These results indicated that the one-step process had high removal efficiency for toxic and refractory hydrophobic organic compounds,and could improve the biodegradability of the coking wastewater.Therefore it could be a promising technology for the pretreatment of toxic and refractory organic wastewater.
基金support from the Fundamental Research Funds for the Central Universities of Hohai university(B200202122)National Natural Science Foundation of China(51878246 and 51979099)+1 种基金the Natural Science Foundation of Jiangsu Province of China(BK20191303)Key Research and Development Project of Jiangsu Province of China(BE2017148).
文摘Formation of super-hydrophobic and corrosion-resistant coatings can provide significant corrosion protection to magnesium alloys.However,it remains a grand challenge to produce such coatings for magnesium-lithium alloys due to their high chemical reactivity.Herein,a one-step hydrothermal processing was developed using a stearic-acid-based precursor medium,which enables the hydrothermal conversion and the formation of low surface energy materials concurrently to produce the super-hydrophobic and corrosion-resistant coating.The multiscale microstructures with nanoscale stacks and microscale spheres on the surface,as well as the through-thickness stearates,lead to the super-hydrophobicity and excellent corrosion resistance of the obtained coating.
基金Projects(11304243,11102164)supported by the National Natural Science Foundation of ChinaProject(2014JQ1039)supported by the Natural Science Foundation of Shannxi Province,China+3 种基金Project(12JK0966)supported by the Shaanxi Provincial Education Department,ChinaProject(2013QDJ037)supported by the Xi’an University of Science and Technology Dr Scientific Research Fund,ChinaProject(3102016ZY027)supported by the Fundamental Research Funds for the Central Universities of ChinaProject(13GH014602)supported by the Program of New Staff and Research Area Project of NPU,China
文摘This work presents a method to solve the weak solubility of zinc chloride(ZnCl_2) in the ethanol by adding some reasonable water into an ethanol electrolyte containing ZnCl_2 and myristic acid(CH_3(CH_2)_(12)COOH).A rapid one-step electrodeposition process was developed to fabricate anodic(2.5 min) and cathodic(40 s) superhydrophobic surfaces of copper substrate(contact angle more than 150°) in an aqueous ethanol electrolyte.Morphology,composition,chemical structure and superhydrophobicity of these superhydrophobic surfaces were investigated by SEM,FTIR,XRD,and contact angle measurement,respectively.The results indicate that water ratio of the electrolyte can reduce the required deposition time,superhydrophobic surface needs over 30 min with anhydrous electrolyte,while it needs only 2.5 min with electrolyte including 10 mL water,and the maximum contact angle of anodic surface is 166° and that of the cathodic surface is 168°.Two copper electrode surfaces have different reactions in the process of electrodeposition time,and the anodic copper surface covers copper myristate(Cu[CH_3(CH_2)_(12)COO]_2) and cupric chloride(CuCl);while,zinc myristate(Zn[CH_3(CH_2)_(12)COO]_2) and pure zinc(Zn) appear on the cathodic surface.
基金This project was supported by the Natural Science Foundation of Beijing (2042012)
文摘By theoretical analysis of heat transfer during the "one-step" directional solidification process, the functional relation between the temperature in solid-liquid interface and its effect factor was studied. The thermal gradient in solid liquid interface and heat transfer coefficient between the samples and surroundings were also calculated. On the basis of the above analysis, some suggestions for improving the thermal gradient in solid-liquid interface were put forward. It will provide a theoretical instruction for preparing high performance giant magnetostrictive materials (GMM).
基金Supported by the National Natural Science Foundation of China(Nos 20233040 and 20572021)
文摘ε-Caprolactam（CL or CPL） is one of the most important intermediates used in polymer industry for the production of several million tons of nylon-6 every year^[1]. All current commercial processes for the production of caprolactam are based on either benzene or tolueneI21. Caprolactam is synthesized by the Beckmann rearrangement of cyclohexanone oxime with fuming sulfuric acid or sulfuric acid as the reaction medium, and cyclohexanone oxime is produced by the reaction between cyclohexanone and hydro- xylamine（only one exception is the Toray PNC process）.
基金National Natural Science Foundation of China (70931004)
文摘For aircraft manufacturing industries, the analyses and prediction of part machining error during machining process are very important to control and improve part machining quality. In order to effectively control machining error, the method of integrating multivariate statistical process control （MSPC） and stream of variations （SoV） is proposed. Firstly, machining error is modeled by multi-operation approaches for part machining process. SoV is adopted to establish the mathematic model of the relationship between the error of upstream operations and the error of downstream operations. Here error sources not only include the influence of upstream operations but also include many of other error sources. The standard model and the predicted model about SoV are built respectively by whether the operation is done or not to satisfy different requests during part machining process. Secondly, the method of one-step ahead forecast error （OSFE） is used to eliminate autocorrelativity of the sample data from the SoV model, and the T2 control chart in MSPC is built to realize machining error detection according to the data characteristics of the above error model, which can judge whether the operation is out of control or not. If it is, then feedback is sent to the operations. The error model is modified by adjusting the operation out of control, and continually it is used to monitor operations. Finally, a machining instance containing two operations demonstrates the effectiveness of the machining error control method presented in this paper.
基金the National Science and Technology Support Project of "the Eleventh Five-year Plan"(2006BAE03B06-03)the New Century Talents Support Program of Chinese Education Department (NCET-04-0614)
文摘AB2-type-prepolymerized monomer was rapidly （2 h） prepared at room temperature （25 ℃） using commercially available maleic anhydride （MA） and diethanolamine （DEA） as raw materials. By employing toluene-p-sulfonic acid as a catalyzer, a series of hyperbranched poly（amide-ester） （HBPAE） were successfully synthesized from prepared AB2 monomer by solution condensation polymerization through ＂one-step process＂ or ＂pseudo one-step process＂ （using pentaerythritol as a center core）. The processes were carried out at high temperature of 120 ℃ for 6 h in air atmosphere （inert protection free） with reduced pressure distillation （0.08--0.096 MPa）. The results of FT-IR, UV-Vis, TGA, and intrinsic viscosity testing by Ubbelodhe viscometer showed that the prepared HBPAEs possess three-dimensional configuration with unsaturated conjugate structure, large numbers of branches and numerous terminal hydroxyl groups. These result in their low viscosity, high solubility and thermal stability.
文摘This paper introduces a new kind of seasonal fractional autoregressive process(SFAR)driven by fractional Gaussian noise(fGn).The new model includes a standard seasonal AR model and fGn.The estimation of the parameters of this new model has to solve two problems:nonstationarity from the seasonal structure and long memory from fGn.We innovatively solve these by getting a stationary subsequence,making a stationary additive sequence and then obtaining their spectral density.Then we use one-step procedure for Generalized Least Squares Estimator(GLSE)and the Geweke Porter–Hudak(GPH)method to get better results.We prove that both the initial and one-step estimators are consistent and asymptotically normal.Finally,we use Monte Carlo simulations with finite-sized samples to demonstrate the performance of these estimators.Moreover,through empirical analysis,it is shown that the SFAR model can simulate some real-world phenomena better than general models.
基金the National Natural Science Foundation of China(52175207)the National Science and Technology Fund Project of China(2020-JCJQ-JJ-378).
文摘In this study,micro/nanostructures are fabricated on the surface of 3Cr13 stainless steel via laser etching,and a superhydrophobic coating with silver nanoparticles(AgNPs)is prepared by utilizing the reduction–adsorption properties of polydopamine(PDA).We investigate the effect of soaking time from the“one-step method”on the reduction of nano-Ag,surface wettability,and antibacterial properties.Scanning electron microscopy is performed to analyze the distribution of nano-Ag on the surface,whereas X-ray energy dispersive spectroscopy and X-ray photoelectron spectroscopy are used to analyze the crystal structures and chemical compositions of different surfaces.Samples deposited with PDA on their surface are soaked in a 1H,1H,2H,2H-perfluorodecyltriethoxysilane water–alcohol solution containing AgNO3 for 3 h.Subsequently,a“one-step method”is used to prepare low-adhesion superhydrophobic surfaces containing AgNPs.As immersion progresses,more AgNPs are deposited onto the surface.Compared with the polished surface,the samples prepared via the“one-step method”show significant antibacterial properties against both gram-negative Escherichia coli and gram-positive Staphylococcus aureus.The antibacterial properties of the surface improve as immersion progresses.
基金supported by the National Natural Science Foundation of China(52072028 and 52032007).
文摘It is well-known that the performance of BiFeO3eBaTiO3(BF-BT)ceramics is sensitive to composition,calcining and sintering temperature(Tcal and Tsint)due to the formation of Bi25FeO39 and/or Bi2Fe4O9 impurities and/or the volatilization of Bi_(2)O_(3).We report remarkably stable electrical properties over the range of0.03≤x≤0.05 and 930℃≤Tsint≤970C in 0.7Bi(1þx)FeO_(3)-0.3BaTiO_(3)ceramics prepared by one-step process.This method avoids the thermodynamically unstable region of BiFeO_(3)and prevents the formation of Bi25FeO39 and/or Bi_(2)Fe_(4)O_(9)impurities even when the addition of a-Bi_(2)O_(3)raw material is intentionally deficient or rich to make off-stoichiometric BF-BT,thus greatly improving the robustness of compositional and processing.Rhombohedral-pseudocubic phase coexists in all ceramics,and their CR/CPC fraction are 48.0/52.0e50.6/49.4 and 55.9/44.1e56.6/43.4 when x increases from0.05≤x≤0 to 0.01≤x≤0.05.The stable electrical properties of d33¼180e205 pC/N,Pr¼17.9e23.8 mC/cm^(2),and TC¼485e518℃are achieved.The maximum d_(33T)/d_(33RT)of BF-BT is twice that of soft PZT,superior to most the-state-of-art lead-free ceramics.Our results provide a synthesis strategy for designing high performance piezoelectric materials with good stability and easy industrialization.
基金support of the National Key Research and Development Program(No.2023YFB4605102)National Natural Science Foundation of China(No.52105437)+2 种基金Heilongjiang Touyan Team(No.HITTY-20190036)Shanghai Aerospace Science and Technology Innovation Fund(No.SAST2021-067)National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(Grant RS-2023-00235596,RS-2023-00243788).
文摘Aqueous zinc-ion batteries provide a most promising alternative to the existing lithium-ion batteries due to their high theoretical capacity,intrinsic safety,and low cost.However,commercializing aqueous zinc-ion batteries suffer from dendritic growth and side reactions on the surface of metallic zinc,resulting in poor reversibility.To overcome this critical challenge,here,we report a one-step ultrafast laser processing method for fabricating three-dimensional micro-/nanostructures on zinc anodes to optimize zinc nucleation and deposition processes.It is demonstrated that the three-dimensional micro-/nanostructure with increased specific surface area significantly reduces nucleation overpotential,as well as preferentially absorbs zinc ions to prevent dendritic protuberances and corrosion.As a result,the presence of threedimensional micro-/nanostructures on the zinc metal delivers stable zinc plating/stripping beyond 2500 h(2 mA cm-2/1 mAh cm-2)in symmetric cells,a high Coulombic efficiency(99.71%)in half cells,and moreover an improved capacity retention(71.8%)is also observed in full cells.Equally intriguingly,the pouch cell with three-dimensional micro-/nanostructures can operate across various bending states without severely compromising performance.This work provides an effective strategy to construct ultrafine and high-precision three-dimensional micro-/nanostructures achieving highperformance zinc metal anodes and is expected to be of immediate benefit to other metal-based electrodes.
基金the National Natural Science Foundation of China(Nos.52373246,62127817,and U23A20380)the National Key Research and Development Program of China(No.2022YFA1404201)+2 种基金Science and Technology Major Special Project of Shanxi Province(No.202201010101005)the Shanxi Province Graduate Innovation Project(No.RC2400005577)the Shanxi Basic Research Program Project(No.20210302123128)for financial support.
文摘Bandgap engineering of semiconductor nanowires or nanoribbons(NRs)offers a promising material foundation for multifunctional integrated optoelectronic devices and circuits.Among these materials,all-inorganic halide perovskites have emerged as a leading candidate for next-generation photoelectronic applications due to their outstanding optoelectronic properties.In this work,we report the direct synthesis of high-quality bandgap gradient lead halide perovskite(CsPbCl_(3−3x)Br_(3x)and CsPbBr_(3−3x)I_(3x)(x=0-1))NRs using a magnetic-pulling source-moving chemical-vapor-deposition(CVD)method.Microstructural characterizations reveal that these as-grown NRs possess high-quality single crystalline structures with continuously tunable compositions.The photoluminescence emissions of these perovskite NRs can be finely tuned across the entire visible spectrum(417-702 nm).Furthermore,photodetectors based on these perovskite NRs demonstrate exceptional photoelectric performance,including a high I_(ON)/I_(OFF)ratio(10^(4)),superior responsivity(37.5 A/W),and remarkable detectivity(2.81×10^(13)Jones).A spatially resolved imaging sensor based on these perovskite NRs is also demonstrated,indicating promising applications in photoelectronic imaging circuits.These bandgap-tunable perovskite NRs provide a versatile materials platform for future integrated devices in electronics and optoelectronics.
文摘1 Results Control of dispersion in synthesized nano-size powders is crucial to the realization of nanoparticles application,such as the fabrication of functional nano-strucured bodies.Dispersion of plasma-synthesized TiO2 nanoparticles,which are formed in-flight in the high temperature thermal plasma,should be superior to those prepared by ordinal wet processes,as the particles have no surface residual groups.RF thermal plasma is characterized by extremely high temperatures,and rapid heating and cooling...
