1 Introduction In recent years porous carbons have been widely used in many fields such as energy storage(Mc Creery,2008;Liu et al,2009;Ho et al,2014;Yang et al,2015),adsorption,wastewater treatment,air purification
Five new zwitterionic surfactants with long chain alkyl betaine structure incorporated with hydroxylpropyl group have been synthesized. Their structures were identified by elemental analysis, IR (HNMR)-H-1, and (CNMR)...Five new zwitterionic surfactants with long chain alkyl betaine structure incorporated with hydroxylpropyl group have been synthesized. Their structures were identified by elemental analysis, IR (HNMR)-H-1, and (CNMR)-C-13. Surface tension experiments showed that these surfactants have higher surface activity than those without hydroxypropyl group. The values of CMC and gamma(CMC) of these surfactants have been determined.展开更多
Surface chemical properties of typical commercial coal-based activated cokes were characterized by Xray photoelectron spectroscopy(XPS) and acid-base titration, and then the influence of surface chemical properties on...Surface chemical properties of typical commercial coal-based activated cokes were characterized by Xray photoelectron spectroscopy(XPS) and acid-base titration, and then the influence of surface chemical properties on catalytic performance of activated cokes of NO reduction with NH3 was investigated in a fixed-bed quartz micro reactor at 150 ℃. The results indicate that the selective catalytic reduction(SCR) activity of activated cokes with the increase of its surface acidic sites and oxygen content,obviously, a correlation between catalytic activity and surface acidic sites content by titration has higher linearity than catalytic activity and surface oxygen content by XPS. While basic sites content by acid-base titration have not correlation with SCR activity. It has been proposed that surface basic sites content measured by titration may not be on adjacent of acidic surface oxides and then cannot form of NO2-like species, thus the reaction of reduction of NO with NH3 have been retarded.展开更多
Human salivary histatin 1(Hst1)exhibits a series of cell-activating properties,such as promoting cell spreading,migration,and metabolic activity.We recently have shown that fluorescently labeled Hst1(F-Hst1)targets an...Human salivary histatin 1(Hst1)exhibits a series of cell-activating properties,such as promoting cell spreading,migration,and metabolic activity.We recently have shown that fluorescently labeled Hst1(F-Hst1)targets and activates mitochondria,presenting an important molecular mechanism.However,its regulating signaling pathways remain to be elucidated.We investigated the influence of specific inhibitors of G protein-coupled receptors(GPCR),endocytosis pathways,extracellular signal-regulated kinases1/2(ERK1/2)signaling,p38 signaling,mitochondrial respiration and Na+/K+-ATPase activity on the uptake,mitochondria-targeting and-activating properties of F-Hst1.We performed a si RNA knockdown(KD)to assess the effect of Sigma-2 receptor(S2R)/Transmembrane Protein 97(TMEM97)—a recently identified target protein of Hst1.We also adopted live cell imaging to monitor the whole intracellular trafficking process of F-Hst1.Our results showed that the inhibition of cellular respiration hindered the internalization of F-Hst1.The inhibitors of GPCR,ERK1/2,phagocytosis,and clathrin-mediated endocytosis(CME)as well as siRNA KD of S2R/TMEM97 significantly reduced the uptake,which was accompanied by the nullification of the promoting effect of F-Hst1 on cell metabolic activity.Only the inhibitor of CME and KD of S2R/TMEM97 significantly compromised the mitochondria-targeting of Hst1.We further showed the intracellular trafficking and targeting process of F-Hst1,in which early endosome plays an important role.Overall,phagocytosis,CME,GPCR,ERK signaling,and S2R/TMEM97 are involved in the internalization of Hst1,while only CME and S2R/TMEM97 are critical for its subcellular targeting.The inhibition of either internalization or mitochondria-targeting of Hst1 could significantly compromise its mitochondria-activating property.展开更多
Synthesis and surface active properties of the oxyethylenated fatty alcohol 2-hydroxypropyl sulfonates were investigated.Of all surface active compounds studied,those with a 2-hydroxypropyl (HP) moiety in the molecule...Synthesis and surface active properties of the oxyethylenated fatty alcohol 2-hydroxypropyl sulfonates were investigated.Of all surface active compounds studied,those with a 2-hydroxypropyl (HP) moiety in the molecule are more surface-active than the corresponding compounds without it.展开更多
In this paper,the functional polymeric active materials were prepared by the grafting copolymerization and their structure and properties were studied.The results show that the structure and properties of these ac- ti...In this paper,the functional polymeric active materials were prepared by the grafting copolymerization and their structure and properties were studied.The results show that the structure and properties of these ac- tive materials have the relative large effects on the properties of gadolinium ion selective electrodes.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
AISI 304 stainless steel plates were welded with activated flux tungsten inert gas(A-TIG) method by utilizing self-developed activated flux. It is indicated from the experimental results that for 8 mm-thick AISI 304 s...AISI 304 stainless steel plates were welded with activated flux tungsten inert gas(A-TIG) method by utilizing self-developed activated flux. It is indicated from the experimental results that for 8 mm-thick AISI 304 stainless steel plate, weld joint of full penetration and one-side welding with good weld appearance can be obtained in a single pass without groove preparation by utilizing A-TIG welding. Moreover, activated flux powders do not cause significant effect on the microstructure of TIG weld and the mechanical properties of A-TIG weld joints are also superior to those of C-TIG(conventional TIG) welding.展开更多
Commercial spherical activated carbon(SAC) was modified by impregnation to enhance the catalytic properties of SAC in acetylene hydrochlorination through melamine modification. Different modification conditions for ...Commercial spherical activated carbon(SAC) was modified by impregnation to enhance the catalytic properties of SAC in acetylene hydrochlorination through melamine modification. Different modification conditions for SAC with nitrogen were compared by changing the SAC-Melamine ratios. The effect of carbonization temperature on the modification was also investigated. Surface chemistry and adsorption properties of the modified and unmodified SACs were studied by scanning electron microscope(SEM), X-ray photoelectron spectroscopy(XPS), elementary analysis, BET, and temperature-programmed desorption(TPD). Moreover, the catalytic properties of SAC in acetylene hydrochlorination under differently modified conditions were also investigated. Elemental analysis showed that the nitrogen content of the modified SAC was greatly improved. XPS revealed that nitrogen mainly exists in Pyrrole nitrogen and Pyridine nitrogen. TPD showed that desorption of C2H2 was changed by modification. The conversion rate of acetylene was up to 70% under the following reaction conditions: temperature, 150 ℃; C2H2 hourly space velocity(GHSV), 36 h-1; feed volume ratio V(HCl)/V(C2H2) = 1.15. The catalytic properties of SAC were improved significantly via melamine modification.展开更多
The role of Nil(NO3)2 in the preparation of a magnetic activated carbon is reported in this paper. Magnetic coal-based activated carbons (MCAC) were prepared from Taixi anthracite with low ash content in the prese...The role of Nil(NO3)2 in the preparation of a magnetic activated carbon is reported in this paper. Magnetic coal-based activated carbons (MCAC) were prepared from Taixi anthracite with low ash content in the presence of Ni(NO3)2. The MCAC materials were characterized by a vibrating sample magnetometer (VSM), X-ray diffraction (XRD), a scanning electric microscope (SEM), and by N2 adsorption. The cylindri- cal precursors and derived char were also subjected to thermogravimetric analysis to compare their behavior of weight losses during carbonization. The results show that MCAC has a larger surface area (1074 m21g) and a higher pore volume (0.5792 cm3/g) with enhanced mesopore ratio (by about 10~). It also has a high saturation magnetization (1.6749 emu/g) and low coercivity (43.26 Oe), which allows the material to be magnetically separated. The MCAC is easily magnetized because the nickel salt is con- vetted into Ni during carbonization and activation. Metallic Ni has a strong magnetism on account of electrostatic interaction. Added Ni(NO3)2 catalyzes the carbonization and activation process by accelerat- ing burn off of the carbon, which contributes to the development of mesopores and macropores in the activated carbon.展开更多
Bio-inspired superhydrophobic magnesium(Mg)alloy surfaces are of increasing interest in corrosion protection due to superior barrier and shielding effects.However,superhydrophobic(SHB)anti-corrosion surfaces are susce...Bio-inspired superhydrophobic magnesium(Mg)alloy surfaces are of increasing interest in corrosion protection due to superior barrier and shielding effects.However,superhydrophobic(SHB)anti-corrosion surfaces are susceptible to damage,which limit their extensive applications.To this end,a micro/nano structure-functional molecule SHB composite coating with self-healing and active anti-corrosion dual-function properties was designed on Mg alloys substrate.The dual-function SHB composite anti-corrosion coating based on lauric acid(La)intercalated and modified hydrotalcite(La-LDH)consisted of three-layer structure,namely La-LDH powder/polydimethylsiloxane(PDMS)/La-LDH film.The anti-corrosion performance of as-prepared coatings was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy(EIS).The results indicate that the SHB coating shows excellent active corrosion resistance.Moreover,we also examined the self-healing and anti-corrosion properties of SHB coating upon physical damage and explained the healing mechanism.After heat treatment,the damaged SHB coating regain its surface microstructure and corrosion protection property.This work expands new insights for the wide application of Mg alloys and the research in the field of metal protection.展开更多
Microstructure, thermodynamics and electrochemicalproperties of novel RE (NiAlCu)x(x= 4.5, 4.9, 5.6 ) microcrystalline hydrogen-storage alloy powder prepared by gas atomization wasinvestigated. It indicates that alloy...Microstructure, thermodynamics and electrochemicalproperties of novel RE (NiAlCu)x(x= 4.5, 4.9, 5.6 ) microcrystalline hydrogen-storage alloy powder prepared by gas atomization wasinvestigated. It indicates that alloyparticles show relatively regularspherical. Microstructure is composed of the AB5 matrix phase andeutectic double-phase structure withthe AB5 phase and Ni3Al along grainboundaries when x = 5. 6, there is acoexistent structure consisting ofAB5 phase and eutectic doublephase with AB3 and AB phases along grain boundaries at x= 4.5.When x is increased to 4.9, themixed structures are composed ofAB5 and a few AB phases in discontinuous network distribution. Theelectrochemical capacity of alloy is210~300 mAh·g-1, and the activated periods are only 1~3 times.lt seems to be ascribed to the appearance of a great number of freshsurfaces within powder particles resulting from the as-quenched microcrack along the interphase boundaries within particles propagatinggradually in the process of hydrogen-absorption-and dissociation dueto the intrinsic double-phase structure.展开更多
The catalytic activity of Perovskite-type mixed oxides (LaCoO3, PrCoO3 and SmCoO3) for the reduction of cyclohexanone to cyclohexanol with 2-propanol (Meerwein-PonndorfVerley reduction) has been studied. The data have...The catalytic activity of Perovskite-type mixed oxides (LaCoO3, PrCoO3 and SmCoO3) for the reduction of cyclohexanone to cyclohexanol with 2-propanol (Meerwein-PonndorfVerley reduction) has been studied. The data have been correlated with the surface electron donor properties of these mixed oxides展开更多
In order to enhance water-solubility and biological utilization rate of tectochrysin,sodium 5-hydroxyl-7-methoxyflavone-6-sulfonate(1) was synthesized and its structure was identified on the basis of ^1 H NMR,FT-IR ...In order to enhance water-solubility and biological utilization rate of tectochrysin,sodium 5-hydroxyl-7-methoxyflavone-6-sulfonate(1) was synthesized and its structure was identified on the basis of ^1 H NMR,FT-IR and elemental analysis.5-Hydroxyl-7-methoxyflavone-6-sulfonate was assembled with Ni(II) or Mn(II),hexaquanickel(II) bis(5-hydroxyl-7-methoxyflavone-6-sulfonate) tetrahydrate(2) and hexaquamanganese(II) bis(5-hydroxyl-7-methoxyflavone-6-sulfonate) tetrahydrate(3) were obtained and characterized by IR spectroscopy.The crystal structures of 2 and 3 were determined by X-ray single-crystal diffraction analysis.The results showed that 2 and 3 are isomorphous crystals and crystallize in monoclinic crystal system,space group C2/c.In 2 and 3,the supramolecular structures are organized into hydrophilic and hydrophobic regions.Hydrophilic regions are generated by O–H???O hydrogen bonds among sulfonate groups,latticed water molecules and coordinated water molecules.The π-π stacking interactions assemble the flavone skeletons into columns and these columns form hydrophobic regions.The sulfonate groups play an important role as a bridge of the hydrophilic and hydrophobic regions as well as the inorganic and organic components.Three-dimensional networks of 2 and 3 are furnished by extensive array of hydrogen bonds,π-π stacking interactions and electrostatic interactions.The anti-proliferative activities of 1-3 in vitro against human leukemia cells K562 and human lung cancer cells A549 were evaluated by the standard MTT assay.The pharmacological activity results showed that the introduction of sulfonic acid groups enhanced the antitumor activity of tectochrysin.展开更多
With the widespread introduction of pre-coagulation prior to the biological unit in various industrial wastewater treatments,it is noteworthy that long-term accumulation of residual coagulants has certains effect on b...With the widespread introduction of pre-coagulation prior to the biological unit in various industrial wastewater treatments,it is noteworthy that long-term accumulation of residual coagulants has certains effect on both micro and macro characteristics of activated sludge(AS).In this study,the morphology distributions of residual aluminum salts(RAS)and their effects on the removal efficiency of AS were investigated under different PAC concentrations.The results showed that the dominance of medium polymeric RAS,formed under an appropriate PAC dose of 20 mg/L enhanced the hydrophobicity,flocculation,and sedimentation performances of AS,as well as the enzymatic activity in cells in the sludge system,improving the main pollutants removal efficiency of the treatment system.Comparatively the species composition with monomer and dimer/high polymer RAS as the overwhelming parts under an over-dosed PAC concentration of 55 mg/L resulted in excessive secretion of EPS with loose flocs structure and conspicuous inhibition of cellular activity,leading to the deterioration of physico-chemical and biological properties of AS.Based on these findings,this study can shed light on the role of the RAS hydrolyzed species distributions,closely relevant to Al dosage,in affecting the comprehensive properties of AS and provide a theoretical reference for coagulants dosage precise control in the pretreatment of industrial wastewater.展开更多
TiO2-loaded activated carbon fibers (ACF) were prepared by a hydrothermal method. The samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR...TiO2-loaded activated carbon fibers (ACF) were prepared by a hydrothermal method. The samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrometry and UV-vis diffuse reflectance spectra (DRS). SEM images showed that the TiO2 nanoparticles were deposited on the surface of ACF, and the particle size and loading amount of TiO2 were varied by changing the initial concentration of tetrabutyl titanate (TBOT). The results of an ash experiment showed that the loading amounts of TiO2 were 18.4%, 43.3%, 52.5%, 75.1%, and 91.1% for initial concentrations of TBOT of 0.07,014, 0.21,0.28, and 0.35 tool/L, respectively, Physical interactions played an important role in the formation of TiO2/ACF composite fibers that absorb UV and visible light. Compared with those of ACF, improved adsorption and photocatalytic activity toward Rhodamine B (RhB) were observed for TiO2/ACF composite fiber. The Rhodamine B could be removed efficiently by TiO2/ACF composite fibers, and the TiO2 loading amount had a significant effect on the photocatalytic activity of TiO2/ACF composite fibers.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 Schiff base L [2-thiophenecarboxylic acid, 2-(2-pyridinylmethylene)hydrazide] with its lanthanide metal complexes was synthesized. These complexes were characterized by elemental analysis, molar conductivity measu...A Schiff base L [2-thiophenecarboxylic acid, 2-(2-pyridinylmethylene)hydrazide] with its lanthanide metal complexes was synthesized. These complexes were characterized by elemental analysis, molar conductivity measurements, spectral analysis(NMR, FT-IR, and UV-Vis), luminescence and thermal gravimetric analysis. The Schiff base ligand was a tridentate chelate and coordinates to the central lanthanide ion with 1:2 metal:ligand ratio. The conductivity data showed a 1:1 electrolytic nature with a general formula [LnL_2(NO_3)_2]NO_3. The luminescence emission properties for Sm, Tb, and Eu complexes were observed and showed that the ligand L could absorb and transfer energy to Sm(III), Tb(III) and Eu(III) ions. The complexes possessed a good antibacterial activity against different bacterial strains. In addition, the scavenging activity of the Ln(III) complexes on DPPH was concentration dependant and the complexes were significantly more efficient in quenching DPPH than the free Schiff base ligand.展开更多
The terminology 'ID frequency'(w ID) is proposed after analyzing the 1D active photonic crystal based on the transfer matrix method. The relationship between wID and the structure parameters of the photonic cr...The terminology 'ID frequency'(w ID) is proposed after analyzing the 1D active photonic crystal based on the transfer matrix method. The relationship between wID and the structure parameters of the photonic crystal is investigated.展开更多
基金financial support from the National Natural Science Foundation of China (51274015)National Program on Key Basic Research Project (973 Program) (2014CB846000)Test Fund of Peking University
文摘1 Introduction In recent years porous carbons have been widely used in many fields such as energy storage(Mc Creery,2008;Liu et al,2009;Ho et al,2014;Yang et al,2015),adsorption,wastewater treatment,air purification
文摘Five new zwitterionic surfactants with long chain alkyl betaine structure incorporated with hydroxylpropyl group have been synthesized. Their structures were identified by elemental analysis, IR (HNMR)-H-1, and (CNMR)-C-13. Surface tension experiments showed that these surfactants have higher surface activity than those without hydroxypropyl group. The values of CMC and gamma(CMC) of these surfactants have been determined.
基金the High Technology Research and Development Program of China(No.2011AA060803)the Beijing Key Laboratory Annual Program(No.Z121103009212039)
文摘Surface chemical properties of typical commercial coal-based activated cokes were characterized by Xray photoelectron spectroscopy(XPS) and acid-base titration, and then the influence of surface chemical properties on catalytic performance of activated cokes of NO reduction with NH3 was investigated in a fixed-bed quartz micro reactor at 150 ℃. The results indicate that the selective catalytic reduction(SCR) activity of activated cokes with the increase of its surface acidic sites and oxygen content,obviously, a correlation between catalytic activity and surface acidic sites content by titration has higher linearity than catalytic activity and surface oxygen content by XPS. While basic sites content by acid-base titration have not correlation with SCR activity. It has been proposed that surface basic sites content measured by titration may not be on adjacent of acidic surface oxides and then cannot form of NO2-like species, thus the reaction of reduction of NO with NH3 have been retarded.
基金funded by Eurostars project,grant number E!12764。
文摘Human salivary histatin 1(Hst1)exhibits a series of cell-activating properties,such as promoting cell spreading,migration,and metabolic activity.We recently have shown that fluorescently labeled Hst1(F-Hst1)targets and activates mitochondria,presenting an important molecular mechanism.However,its regulating signaling pathways remain to be elucidated.We investigated the influence of specific inhibitors of G protein-coupled receptors(GPCR),endocytosis pathways,extracellular signal-regulated kinases1/2(ERK1/2)signaling,p38 signaling,mitochondrial respiration and Na+/K+-ATPase activity on the uptake,mitochondria-targeting and-activating properties of F-Hst1.We performed a si RNA knockdown(KD)to assess the effect of Sigma-2 receptor(S2R)/Transmembrane Protein 97(TMEM97)—a recently identified target protein of Hst1.We also adopted live cell imaging to monitor the whole intracellular trafficking process of F-Hst1.Our results showed that the inhibition of cellular respiration hindered the internalization of F-Hst1.The inhibitors of GPCR,ERK1/2,phagocytosis,and clathrin-mediated endocytosis(CME)as well as siRNA KD of S2R/TMEM97 significantly reduced the uptake,which was accompanied by the nullification of the promoting effect of F-Hst1 on cell metabolic activity.Only the inhibitor of CME and KD of S2R/TMEM97 significantly compromised the mitochondria-targeting of Hst1.We further showed the intracellular trafficking and targeting process of F-Hst1,in which early endosome plays an important role.Overall,phagocytosis,CME,GPCR,ERK signaling,and S2R/TMEM97 are involved in the internalization of Hst1,while only CME and S2R/TMEM97 are critical for its subcellular targeting.The inhibition of either internalization or mitochondria-targeting of Hst1 could significantly compromise its mitochondria-activating property.
文摘Synthesis and surface active properties of the oxyethylenated fatty alcohol 2-hydroxypropyl sulfonates were investigated.Of all surface active compounds studied,those with a 2-hydroxypropyl (HP) moiety in the molecule are more surface-active than the corresponding compounds without it.
文摘In this paper,the functional polymeric active materials were prepared by the grafting copolymerization and their structure and properties were studied.The results show that the structure and properties of these ac- tive materials have the relative large effects on the properties of gadolinium ion selective electrodes.
基金This project was supported by National Nature Science Foundation and Opening Foundation of State Key L aboratory ofFunctional Polymer Materials for Adsorption and Separation in Nankai U niversity
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Project(2011DFB70130) supported by International Scientific and Technological Cooperation of Ministry of Science and Technology of ChinaProject(2012B050100015) supported by Science and Technology Planning Program of Guangdong Province,China
文摘AISI 304 stainless steel plates were welded with activated flux tungsten inert gas(A-TIG) method by utilizing self-developed activated flux. It is indicated from the experimental results that for 8 mm-thick AISI 304 stainless steel plate, weld joint of full penetration and one-side welding with good weld appearance can be obtained in a single pass without groove preparation by utilizing A-TIG welding. Moreover, activated flux powders do not cause significant effect on the microstructure of TIG weld and the mechanical properties of A-TIG weld joints are also superior to those of C-TIG(conventional TIG) welding.
基金Funded by the National Basic Research Program of China(973 Program,2012CB720302)the Program for Changjiang Scholars and Innovative Research Team in University(No.IRT1161)the Corps Science and Technology Innovation Team Scheme(2011CC001)
文摘Commercial spherical activated carbon(SAC) was modified by impregnation to enhance the catalytic properties of SAC in acetylene hydrochlorination through melamine modification. Different modification conditions for SAC with nitrogen were compared by changing the SAC-Melamine ratios. The effect of carbonization temperature on the modification was also investigated. Surface chemistry and adsorption properties of the modified and unmodified SACs were studied by scanning electron microscope(SEM), X-ray photoelectron spectroscopy(XPS), elementary analysis, BET, and temperature-programmed desorption(TPD). Moreover, the catalytic properties of SAC in acetylene hydrochlorination under differently modified conditions were also investigated. Elemental analysis showed that the nitrogen content of the modified SAC was greatly improved. XPS revealed that nitrogen mainly exists in Pyrrole nitrogen and Pyridine nitrogen. TPD showed that desorption of C2H2 was changed by modification. The conversion rate of acetylene was up to 70% under the following reaction conditions: temperature, 150 ℃; C2H2 hourly space velocity(GHSV), 36 h-1; feed volume ratio V(HCl)/V(C2H2) = 1.15. The catalytic properties of SAC were improved significantly via melamine modification.
基金support by the National Natural Science Foundation of China (No. 20776150)the National Hi-Tech Research and Development Program of China(No. 2008AA05Z308)the Special Fund for Basic Scientific Research of Central Colleges (No. 2009QH15)
文摘The role of Nil(NO3)2 in the preparation of a magnetic activated carbon is reported in this paper. Magnetic coal-based activated carbons (MCAC) were prepared from Taixi anthracite with low ash content in the presence of Ni(NO3)2. The MCAC materials were characterized by a vibrating sample magnetometer (VSM), X-ray diffraction (XRD), a scanning electric microscope (SEM), and by N2 adsorption. The cylindri- cal precursors and derived char were also subjected to thermogravimetric analysis to compare their behavior of weight losses during carbonization. The results show that MCAC has a larger surface area (1074 m21g) and a higher pore volume (0.5792 cm3/g) with enhanced mesopore ratio (by about 10~). It also has a high saturation magnetization (1.6749 emu/g) and low coercivity (43.26 Oe), which allows the material to be magnetically separated. The MCAC is easily magnetized because the nickel salt is con- vetted into Ni during carbonization and activation. Metallic Ni has a strong magnetism on account of electrostatic interaction. Added Ni(NO3)2 catalyzes the carbonization and activation process by accelerat- ing burn off of the carbon, which contributes to the development of mesopores and macropores in the activated carbon.
基金supported by the Fundamental Research Fund(No.2020-JCJQ-JJ-008)the National Natural Science Foundation of China(No.21871020)the Postdoctoral Research Foundation of China(Nos.2021TQ0023,2020M680296,2022T150035 and 2022TQ0022).
文摘Bio-inspired superhydrophobic magnesium(Mg)alloy surfaces are of increasing interest in corrosion protection due to superior barrier and shielding effects.However,superhydrophobic(SHB)anti-corrosion surfaces are susceptible to damage,which limit their extensive applications.To this end,a micro/nano structure-functional molecule SHB composite coating with self-healing and active anti-corrosion dual-function properties was designed on Mg alloys substrate.The dual-function SHB composite anti-corrosion coating based on lauric acid(La)intercalated and modified hydrotalcite(La-LDH)consisted of three-layer structure,namely La-LDH powder/polydimethylsiloxane(PDMS)/La-LDH film.The anti-corrosion performance of as-prepared coatings was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy(EIS).The results indicate that the SHB coating shows excellent active corrosion resistance.Moreover,we also examined the self-healing and anti-corrosion properties of SHB coating upon physical damage and explained the healing mechanism.After heat treatment,the damaged SHB coating regain its surface microstructure and corrosion protection property.This work expands new insights for the wide application of Mg alloys and the research in the field of metal protection.
文摘Microstructure, thermodynamics and electrochemicalproperties of novel RE (NiAlCu)x(x= 4.5, 4.9, 5.6 ) microcrystalline hydrogen-storage alloy powder prepared by gas atomization wasinvestigated. It indicates that alloyparticles show relatively regularspherical. Microstructure is composed of the AB5 matrix phase andeutectic double-phase structure withthe AB5 phase and Ni3Al along grainboundaries when x = 5. 6, there is acoexistent structure consisting ofAB5 phase and eutectic doublephase with AB3 and AB phases along grain boundaries at x= 4.5.When x is increased to 4.9, themixed structures are composed ofAB5 and a few AB phases in discontinuous network distribution. Theelectrochemical capacity of alloy is210~300 mAh·g-1, and the activated periods are only 1~3 times.lt seems to be ascribed to the appearance of a great number of freshsurfaces within powder particles resulting from the as-quenched microcrack along the interphase boundaries within particles propagatinggradually in the process of hydrogen-absorption-and dissociation dueto the intrinsic double-phase structure.
文摘The catalytic activity of Perovskite-type mixed oxides (LaCoO3, PrCoO3 and SmCoO3) for the reduction of cyclohexanone to cyclohexanol with 2-propanol (Meerwein-PonndorfVerley reduction) has been studied. The data have been correlated with the surface electron donor properties of these mixed oxides
基金supported by the Youth Backbone Teachers Project Funded by Xianyang Normal University(No.XSYGG201606)Scientific Research Program Funded by Shaanxi Provincial Education Department(No.16JK1822)Natural Science Basic Research Plan Funded by Shaanxi Province of China(No.2016JM5024)
文摘In order to enhance water-solubility and biological utilization rate of tectochrysin,sodium 5-hydroxyl-7-methoxyflavone-6-sulfonate(1) was synthesized and its structure was identified on the basis of ^1 H NMR,FT-IR and elemental analysis.5-Hydroxyl-7-methoxyflavone-6-sulfonate was assembled with Ni(II) or Mn(II),hexaquanickel(II) bis(5-hydroxyl-7-methoxyflavone-6-sulfonate) tetrahydrate(2) and hexaquamanganese(II) bis(5-hydroxyl-7-methoxyflavone-6-sulfonate) tetrahydrate(3) were obtained and characterized by IR spectroscopy.The crystal structures of 2 and 3 were determined by X-ray single-crystal diffraction analysis.The results showed that 2 and 3 are isomorphous crystals and crystallize in monoclinic crystal system,space group C2/c.In 2 and 3,the supramolecular structures are organized into hydrophilic and hydrophobic regions.Hydrophilic regions are generated by O–H???O hydrogen bonds among sulfonate groups,latticed water molecules and coordinated water molecules.The π-π stacking interactions assemble the flavone skeletons into columns and these columns form hydrophobic regions.The sulfonate groups play an important role as a bridge of the hydrophilic and hydrophobic regions as well as the inorganic and organic components.Three-dimensional networks of 2 and 3 are furnished by extensive array of hydrogen bonds,π-π stacking interactions and electrostatic interactions.The anti-proliferative activities of 1-3 in vitro against human leukemia cells K562 and human lung cancer cells A549 were evaluated by the standard MTT assay.The pharmacological activity results showed that the introduction of sulfonic acid groups enhanced the antitumor activity of tectochrysin.
基金The authors disclosed receipt of the following financial support for the research,authorship,and/or publication of this article:This work was supported by the Hubei Provincial Key Laboratory of Water System Science for Sponge City Construction(No.2019-06)the Science and Technology Program of Shenzhen(No.JCYJ20210324122602006).
文摘With the widespread introduction of pre-coagulation prior to the biological unit in various industrial wastewater treatments,it is noteworthy that long-term accumulation of residual coagulants has certains effect on both micro and macro characteristics of activated sludge(AS).In this study,the morphology distributions of residual aluminum salts(RAS)and their effects on the removal efficiency of AS were investigated under different PAC concentrations.The results showed that the dominance of medium polymeric RAS,formed under an appropriate PAC dose of 20 mg/L enhanced the hydrophobicity,flocculation,and sedimentation performances of AS,as well as the enzymatic activity in cells in the sludge system,improving the main pollutants removal efficiency of the treatment system.Comparatively the species composition with monomer and dimer/high polymer RAS as the overwhelming parts under an over-dosed PAC concentration of 55 mg/L resulted in excessive secretion of EPS with loose flocs structure and conspicuous inhibition of cellular activity,leading to the deterioration of physico-chemical and biological properties of AS.Based on these findings,this study can shed light on the role of the RAS hydrolyzed species distributions,closely relevant to Al dosage,in affecting the comprehensive properties of AS and provide a theoretical reference for coagulants dosage precise control in the pretreatment of industrial wastewater.
基金financial support of the National Natural Science Foundation of China(No.21103017No.51104042)the Fundamental Research Funds for the Central Universities(No.110405007)
文摘TiO2-loaded activated carbon fibers (ACF) were prepared by a hydrothermal method. The samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrometry and UV-vis diffuse reflectance spectra (DRS). SEM images showed that the TiO2 nanoparticles were deposited on the surface of ACF, and the particle size and loading amount of TiO2 were varied by changing the initial concentration of tetrabutyl titanate (TBOT). The results of an ash experiment showed that the loading amounts of TiO2 were 18.4%, 43.3%, 52.5%, 75.1%, and 91.1% for initial concentrations of TBOT of 0.07,014, 0.21,0.28, and 0.35 tool/L, respectively, Physical interactions played an important role in the formation of TiO2/ACF composite fibers that absorb UV and visible light. Compared with those of ACF, improved adsorption and photocatalytic activity toward Rhodamine B (RhB) were observed for TiO2/ACF composite fiber. The Rhodamine B could be removed efficiently by TiO2/ACF composite fibers, and the TiO2 loading amount had a significant effect on the photocatalytic activity of TiO2/ACF composite fibers.
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Project supported by Jordan University of Science and Technology Research Fund Project(2011/202)
文摘A Schiff base L [2-thiophenecarboxylic acid, 2-(2-pyridinylmethylene)hydrazide] with its lanthanide metal complexes was synthesized. These complexes were characterized by elemental analysis, molar conductivity measurements, spectral analysis(NMR, FT-IR, and UV-Vis), luminescence and thermal gravimetric analysis. The Schiff base ligand was a tridentate chelate and coordinates to the central lanthanide ion with 1:2 metal:ligand ratio. The conductivity data showed a 1:1 electrolytic nature with a general formula [LnL_2(NO_3)_2]NO_3. The luminescence emission properties for Sm, Tb, and Eu complexes were observed and showed that the ligand L could absorb and transfer energy to Sm(III), Tb(III) and Eu(III) ions. The complexes possessed a good antibacterial activity against different bacterial strains. In addition, the scavenging activity of the Ln(III) complexes on DPPH was concentration dependant and the complexes were significantly more efficient in quenching DPPH than the free Schiff base ligand.
文摘The terminology 'ID frequency'(w ID) is proposed after analyzing the 1D active photonic crystal based on the transfer matrix method. The relationship between wID and the structure parameters of the photonic crystal is investigated.