Selective oxidation of glycerol is a hot topic.Increased biodiesel production has led to glycerol oxidation over Au- and Pt-based catalysts being widely studied.However,Pt catalysts suffer from deactivation because of...Selective oxidation of glycerol is a hot topic.Increased biodiesel production has led to glycerol oxidation over Au- and Pt-based catalysts being widely studied.However,Pt catalysts suffer from deactivation because of weak metal-support interactions.In this study,multi-walled carbon nanotube(MWCNTs)-pillared nitrogen-doped graphene(NG) was prepared by direct pyrolysis of melamine on MWCNTs,and the synthesized NG-MWCNT composite was used as the support for Pt.Characterization results showed that the surface area(173 m^2/g) and pore volume of the NG-MWCNT composite were greater than those of bare MWCNTs and the separated melamine pyrolysis product(CH_x).Pt(1.4±0.4 nm) dispersion on the NG-MWCNTs was favorable and the Pt/NG-MWCNT catalyst was highly active and selective in the oxidation of glycerol to glyceric acid(GLYA) in base-free aqueous solution.For example,the conversion of glycerol reached 64.4% with a GLYA selectivity of 81.0%,whereas the conversions of glycerol over Pt/MWCNTs and Pt/CN_x were 29.0% and 31.6%,respectively.The unique catalytic activity of the Pt/NG-MWCNTs is attributed to well-dispersed Pt clusters on the NG-MWCNTs and the electron-donating effect of the nitrogen dopant in the NG-MWCNTs.展开更多
Pyrolysis has the potential of transforming waste into valuable products. Pyrolytic carbon black (PCB) is one of the most important products resulting from the pyrolysis of used tires. One of the most significant appl...Pyrolysis has the potential of transforming waste into valuable products. Pyrolytic carbon black (PCB) is one of the most important products resulting from the pyrolysis of used tires. One of the most significant applica-tions of modified pyrolytic carbon black is its use as pigment for offset printing ink to obtain high added values. Inverse gas chromatography (IGC) results show that a large quantity of inorganic matters and carbonaceous deposit are removed by treating the pyrolytic carbon black with nitric acid solution. Plenty of active sites originally occu-pied by inorganic ash and coke are recovered. The surface energy of pyrolytic carbon black (TWPC)modified by titanate-coupling agent-especially the specific interaction γ sspdetermined by the specific probe molecule, tolu-ene-shows the strong interaction between the TWPC and the synthetic resins. The offset printing ink performance confirms the IGC prediction. And TWPC has the great potential of applications in printing ink industry as pigment.展开更多
Finer nanoplates of silver are prepared by self-assembly on the surface of graphene,and the low-temperature sintered high conductivity ink containing the silver nanoplates is prepared.Most importantly,graphene is adde...Finer nanoplates of silver are prepared by self-assembly on the surface of graphene,and the low-temperature sintered high conductivity ink containing the silver nanoplates is prepared.Most importantly,graphene is added to the solution before the chemical reduction reaction occurs.Firstly,it is found that silver nanoplates have self-assembly phenomenon on the surface of graphene.Secondly,the Ag nano hexagonal platelets(AgNHPs)with small particle sizes(10 nm),narrow distribution and good dispersion are prepared.Especially,smaller sizes(10 nm)and narrower particle size distribution of AgNHPs particles can be easily controlled by using this process.Finally,the conductivity of the ink is excellent.For example,when the printed patterns were sintering at 150℃,the resistivity of the ink(GE:0.15 g/L)reached the minimum value of 2.2×10^-6 cm.And the resistivity value was 3.7×10^-6Ωcm,when it was sintered at 100℃ for 30 min.The conductive ink prepared can be used for the field of printing electronics as ink-jet printing ink.展开更多
Graphite antimony composites were prepared using a mechanical pressure infiltration method to force molten antimony into graphite preforms having a percolation micro-structure and a hop-pocket power filler. The micro-...Graphite antimony composites were prepared using a mechanical pressure infiltration method to force molten antimony into graphite preforms having a percolation micro-structure and a hop-pocket power filler. The micro-structural and macroscopic properties of the graphite antimony composites were analysed. Observations included metallographic analysis, physical properties and friction and wear behaviour. The results show that the wear loss is decreased by 12.24% and that the friction coefficient is re-duced by 32.61% after hop-pocket power was used. The research indicates that the hop-pocket power method gives a useful way to reduce friction coefficients and wear loss, and to increase service life and self-lubrication properties, of the graphite antimony seal-ing material as compared to carbon black.展开更多
In this paper exact solutions of a new modified nonlinearly dispersive equation (simply called inK(m, n, a, b) Ua Ub equation), u^m-1 ut + α( u^n)x +β(u^a(u^b)xx)x = 0, is investigated by using some dir...In this paper exact solutions of a new modified nonlinearly dispersive equation (simply called inK(m, n, a, b) Ua Ub equation), u^m-1 ut + α( u^n)x +β(u^a(u^b)xx)x = 0, is investigated by using some direct algorithms. As a result, abundant new compacton solutions (solitons with the absence of infinite wings) and solitary pattern solutions (having infinite slopes or cusps) are obtained.展开更多
Expanded graphite (r-;G) shows higher adsorption capacity for oils than for dyes. To illustrate the different adsorption mechanism of EG for these pollutants, adsorption capacities of dyes and oil on EG were firs...Expanded graphite (r-;G) shows higher adsorption capacity for oils than for dyes. To illustrate the different adsorption mechanism of EG for these pollutants, adsorption capacities of dyes and oil on EG were firstly studied. And then stepwise adsorption for oils was carried out with EG which has been saturated firstly by dyes, the difference between adsorbance of oil on EG was checked with deviation analysis. Scanning electronic microscopy (SEM) analysis was used to show structure difference of EG adsorbed different adsorbates. These used adsorbates were SD300 oil, basic fuchsine, Auramine lake yellow O and acid brilliant red 3B. The adsorption isotherm of dyes on EG is type 11 or type 1, and their equilibrium adsorbances are less than 1.0 g/g. While, adsorbance for SD300 oil can reach 104.5 g/g. Deviation analysis for stepwise adsorbances of oil shows no statistical significance. EG saturated firstly by dyes, still has an average adsorption capacity of 35 g/g for SD300 oil, and it does not change with the initial dyes concentration. SEM photos illustrate the adsorption of oil on EG is mainly filling, In the adsorption of dyes, there is severe breakage of the V-type pore and shrinkage of the particle. Kinetic difference is analyzed also.展开更多
In order to research how the size of the ink flow channel is affected by the interaction of adjacent ink areas,according to the method of fluid-solid interaction,this paper analyzes the size of the ink flow channel of...In order to research how the size of the ink flow channel is affected by the interaction of adjacent ink areas,according to the method of fluid-solid interaction,this paper analyzes the size of the ink flow channel of two ink rollers' rotation.Firstly,this paper simulates the situation of only one ink area.Secondly,this paper simulates the situation of five adjacent ink areas.Then,through comparing the simulation results of two above situations,it' s obvious that the interaction of adjacent ink areas has big effects on the ink pressure and the size of ink flow channel.At last,this paper gets the main factor that affects the size of ink flow channel in the different situations.展开更多
With spreading and deepening of intangible cultural heritage protection movement in this century, Chinese ink art is among the Masterpieces of the Oral and Intangible Heritage of Humanity. Institutions of higher educa...With spreading and deepening of intangible cultural heritage protection movement in this century, Chinese ink art is among the Masterpieces of the Oral and Intangible Heritage of Humanity. Institutions of higher education is an academic heritage, culture, communication, personnel training platform and carrier, we assume an important role in the protection of heritage and ink art. Modem design teaching is in order to better local cultural heritage, but also to change their design education, more and more traditional elements are used in the classroom student design works. This paper aims to cultural connotations of traditional Chinese ink painting itself carrying elements and aesthetic charm of the excavation, analysis and sorting, which will be teaching in their designs into modem art. The contemporary art and design are to make cultural connotation and aesthetic meaning, making a good combination of tradition and art.展开更多
PVA (Polyvinyl Alcohol) is a water soluble organic dielectric, easily solution processed to fabricate films by spin coating, dip coating or inkjet printing. It has been used as a dielectric layer in OTFTs (organic ...PVA (Polyvinyl Alcohol) is a water soluble organic dielectric, easily solution processed to fabricate films by spin coating, dip coating or inkjet printing. It has been used as a dielectric layer in OTFTs (organic thin film transistors), and its dielectric constant is around 3.5-10. For OTFTs operating at lower voltage, it is desirable to increase the dielectric constant. Here, we report a technique to incorporate upto 50 wt% of TiO2 nanoparticles (15-25 nm) in PVA to increase its dielectric constant. Rutile phase of TiO2 is used, because of its higher dielectric constant (e = 114) compared to anatase phase (E = 31). We have made inks containing 10 and 50 wt% (of PVA) TiO2 nanoparticles, which is stable upto six months. PVA-TiO2 dispersions and PVA (without TiO2) were spin coated on indium tin oxide coated polyethylene terephthalate substrate. Film structure was studied using SEM (scanning electron microscopy). Absorption study of the films confirms presence of TiO2 nanoparticles. M-I-M capacitors were fabricated by thermally evaporating aluminium on top of the dielectric films. We observed enhancement in dielectric constant by a factor of 2 for PVA containing 50 wt% TiO2 in comparison to PVA's dielectric constant. There is no concomitant increase in the leakage current.展开更多
The past six years (2008-2014) was a prosperous time for exploration and production in the dGOM (deepwater Gulf of Mexico). Recent exploration and production activities can be divided into three major categories:...The past six years (2008-2014) was a prosperous time for exploration and production in the dGOM (deepwater Gulf of Mexico). Recent exploration and production activities can be divided into three major categories: drilling new wildcat wells, appraising and developing newly discovered fields and enhanced oil recovery of mature fields. Seismic imaging, complex geology, high pressure drilling, greater depth, and higher temperature are key challenges for the exploration and production of dGOM reservoirs. Complex geology includes salt-related structures and traps, reservoir compartmentalization, and the sequence stratigraphy of turbidite reservoirs. Turbidite sequence stratigraphy helps the asset team to fred the best target intervals. Sheet and channelized sandstones with good downdip aquifer support are preferred reservoir conditions. All the drilling, development and production challenges are related to high pressure, greater depth, higher temperature and lack of existing field analogs. Various IOR (improved oil recovery) methods are studied and applied in the development stage of the Wilcox fields, which have an average primary recovery factor of 10%-15%. With ideal tabular reservoir geometry and IOR methods, recovery factor of the Wilcox reservoirs can reach up to 42% of OOIP (origional oil in place) through the field life cycle.展开更多
Graphite nanoplatelets were prepared by a novel magnetic-grinding method using self-made equipments. Under a variant magnetic field, magnetic needles collided at a high rotating speed and exfoliated pristine graphite ...Graphite nanoplatelets were prepared by a novel magnetic-grinding method using self-made equipments. Under a variant magnetic field, magnetic needles collided at a high rotating speed and exfoliated pristine graphite into graphite nanoplatelets with high efficiency. The obtained graphite nanoplatelets are highly crystalline, and the thickness is less than 10 nm. Moreover, the surface area could reached 738.1 m^2/g with a grinding time of 4 h. Silanized graphite nanoplatelets can disperse well in SG 15W-40 engine oil and serve as lubricant additive. Tribological results indicate that the friction coefficient and wear-scar of the friction pairs are lower than 76% and 41%, respectively, by adding 1.5‰(mass fraction) of silanized graphite nanoplatelets. Notably, the functionalized graphite nanoplatelets can realize large-scale production and commercial application.展开更多
The deepwater horizon blowout led to the release of 4.9 million barrels of crude oil into the Gulf of Mexico (GOM). Here the paper analyzes available sediment datasets to determine whether changes in petrogenic cont...The deepwater horizon blowout led to the release of 4.9 million barrels of crude oil into the Gulf of Mexico (GOM). Here the paper analyzes available sediment datasets to determine whether changes in petrogenic contaminants are evident in GOM sediment following the blowout. Locations sampled by EPA (Environmental Protection Agency), British Petroleum (BP) and NOAA (National Oceanic and Atmospheric Administration) were reduced and grouped into 46 similar locations and analyzed. Eleven groups suggested an increase in PAIl (polycyclic aromatic hydrocarbon) and nickel, one group showed a statistically significant increase in Phenanthrene. Four locations were analyzed for time trends and differences between initial and peak concentrations of oil range organics (ORO), diesel range organics (DRO), vanadium and nickel. One location had significant increases in ORO, DRO and vanadium and a suggestive increase in nickel. Correlations between ORO/DRO, ORO/V, ORO/Ni, V/Ni were computed (RE= 0.85, 0.67, 0.64, 0.92, respectively). Overall, the analyses suggest that future monitoring should employ a sampling strategy that coordinates response sampling to previously sampled locations, such that baseline datasets can be used in detection of event associated contamination.展开更多
A series of inkjet printing processes have been studied using graphene-based inks. Under optimized conditions, using water-soluble single-layered graphene oxide (GO) and few-layered graphene oxide (FGO), various h...A series of inkjet printing processes have been studied using graphene-based inks. Under optimized conditions, using water-soluble single-layered graphene oxide (GO) and few-layered graphene oxide (FGO), various high image quality patterns could be printed on diverse flexible substrates, including paper, poly(ethylene terephthalate) (PET) and polyimide (PI), with a simple and low-cost inkjet printing technique. The graphene-based patterns printed on plastic substrates demonstrated a high electrical conductivity after thermal reduction, and more importantly, they retained the same conductivity over severe bending cycles. Accordingly, flexible electric circuits and a hydrogen peroxide chemical sensor were fabricated and showed excellent performances, demonstrating the applications of this simple and practical inkjet printing technique using graphene inks. The results show that graphene materials--which can be easily produced on a large scale and possess outstanding electronic properties--have great potential for the convenient fabrication of flexible and low-cost graphene- based electronic devices, by using a simple inkjet printing technique.展开更多
The currently available 3D printing still cannot simultaneously deal with the metal and nonmetal inks together due to their huge difference in the melting points and poor compatible printability between each other. He...The currently available 3D printing still cannot simultaneously deal with the metal and nonmetal inks together due to their huge difference in the melting points and poor compatible printability between each other. Here through introducing the low melting point alloy Bi35In48.6Sn16Zno.4 and silicone rubber as functional inks, we proposed a compatible hybrid 3D printing method for manufacturing the desired device, the supporting substrate and the allied package structure together. The principle of pneumatic-typed 3D printing of multiple inks was described and typical physical properties of the ink Bi35In48.6Sn16Zno.4 were measured. Several key factors dominating the printing quality such as the temperature of the printing head, the air pressure exerted upon the liquid metal ink in the syringe, the moving velocity and the height of the printing head etc. were clarified. A general way of directly printing out 3D structured electronic devices consisting of both metal and nonmetal materials was demonstrated. Such hybrid objects were patterned and formed up layer by layer with Bi35In48.6Sn16Zno.4 alloy and silicone rub- ber which would become solidified after standing for a period of time under room temperature. To illustrate the compatible printability of these printing inks, a three-layer tricolor LED stereo circuit with controlled lighting capability was further man- ufactured and evaluated. The present study opens an important hybrid 3D printing way for directly manufacturing functional and structural end devices in an easy and low cost way.展开更多
基金financially supported by the National Natural Science Foundation of China(21473155,21273198,21073159)Natural Science Foundation of Zhejiang Province(L12B03001)the foundation from State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology(GCTKF2014009)~~
文摘Selective oxidation of glycerol is a hot topic.Increased biodiesel production has led to glycerol oxidation over Au- and Pt-based catalysts being widely studied.However,Pt catalysts suffer from deactivation because of weak metal-support interactions.In this study,multi-walled carbon nanotube(MWCNTs)-pillared nitrogen-doped graphene(NG) was prepared by direct pyrolysis of melamine on MWCNTs,and the synthesized NG-MWCNT composite was used as the support for Pt.Characterization results showed that the surface area(173 m^2/g) and pore volume of the NG-MWCNT composite were greater than those of bare MWCNTs and the separated melamine pyrolysis product(CH_x).Pt(1.4±0.4 nm) dispersion on the NG-MWCNTs was favorable and the Pt/NG-MWCNT catalyst was highly active and selective in the oxidation of glycerol to glyceric acid(GLYA) in base-free aqueous solution.For example,the conversion of glycerol reached 64.4% with a GLYA selectivity of 81.0%,whereas the conversions of glycerol over Pt/MWCNTs and Pt/CN_x were 29.0% and 31.6%,respectively.The unique catalytic activity of the Pt/NG-MWCNTs is attributed to well-dispersed Pt clusters on the NG-MWCNTs and the electron-donating effect of the nitrogen dopant in the NG-MWCNTs.
基金Supported by the National Natural Science Foundation of China (No.20176051) and the Key Natural Science Foundation ofChina (No.20490205).
文摘Pyrolysis has the potential of transforming waste into valuable products. Pyrolytic carbon black (PCB) is one of the most important products resulting from the pyrolysis of used tires. One of the most significant applica-tions of modified pyrolytic carbon black is its use as pigment for offset printing ink to obtain high added values. Inverse gas chromatography (IGC) results show that a large quantity of inorganic matters and carbonaceous deposit are removed by treating the pyrolytic carbon black with nitric acid solution. Plenty of active sites originally occu-pied by inorganic ash and coke are recovered. The surface energy of pyrolytic carbon black (TWPC)modified by titanate-coupling agent-especially the specific interaction γ sspdetermined by the specific probe molecule, tolu-ene-shows the strong interaction between the TWPC and the synthetic resins. The offset printing ink performance confirms the IGC prediction. And TWPC has the great potential of applications in printing ink industry as pigment.
基金Project(2018GK4015)supported by the Hunan Provincial Strategic Emerging Industry Project,China
文摘Finer nanoplates of silver are prepared by self-assembly on the surface of graphene,and the low-temperature sintered high conductivity ink containing the silver nanoplates is prepared.Most importantly,graphene is added to the solution before the chemical reduction reaction occurs.Firstly,it is found that silver nanoplates have self-assembly phenomenon on the surface of graphene.Secondly,the Ag nano hexagonal platelets(AgNHPs)with small particle sizes(10 nm),narrow distribution and good dispersion are prepared.Especially,smaller sizes(10 nm)and narrower particle size distribution of AgNHPs particles can be easily controlled by using this process.Finally,the conductivity of the ink is excellent.For example,when the printed patterns were sintering at 150℃,the resistivity of the ink(GE:0.15 g/L)reached the minimum value of 2.2×10^-6 cm.And the resistivity value was 3.7×10^-6Ωcm,when it was sintered at 100℃ for 30 min.The conductive ink prepared can be used for the field of printing electronics as ink-jet printing ink.
基金Project 2006A021 supported by the Science Foundation of China University of Mining & Technology
文摘Graphite antimony composites were prepared using a mechanical pressure infiltration method to force molten antimony into graphite preforms having a percolation micro-structure and a hop-pocket power filler. The micro-structural and macroscopic properties of the graphite antimony composites were analysed. Observations included metallographic analysis, physical properties and friction and wear behaviour. The results show that the wear loss is decreased by 12.24% and that the friction coefficient is re-duced by 32.61% after hop-pocket power was used. The research indicates that the hop-pocket power method gives a useful way to reduce friction coefficients and wear loss, and to increase service life and self-lubrication properties, of the graphite antimony seal-ing material as compared to carbon black.
基金Sponsored by K.C.Wong Magna Fund in Ningbo University and Ningbo Natural Science Foundation under Grant Nos.2008A610017 and 2007A610049
文摘In this paper exact solutions of a new modified nonlinearly dispersive equation (simply called inK(m, n, a, b) Ua Ub equation), u^m-1 ut + α( u^n)x +β(u^a(u^b)xx)x = 0, is investigated by using some direct algorithms. As a result, abundant new compacton solutions (solitons with the absence of infinite wings) and solitary pattern solutions (having infinite slopes or cusps) are obtained.
文摘Expanded graphite (r-;G) shows higher adsorption capacity for oils than for dyes. To illustrate the different adsorption mechanism of EG for these pollutants, adsorption capacities of dyes and oil on EG were firstly studied. And then stepwise adsorption for oils was carried out with EG which has been saturated firstly by dyes, the difference between adsorbance of oil on EG was checked with deviation analysis. Scanning electronic microscopy (SEM) analysis was used to show structure difference of EG adsorbed different adsorbates. These used adsorbates were SD300 oil, basic fuchsine, Auramine lake yellow O and acid brilliant red 3B. The adsorption isotherm of dyes on EG is type 11 or type 1, and their equilibrium adsorbances are less than 1.0 g/g. While, adsorbance for SD300 oil can reach 104.5 g/g. Deviation analysis for stepwise adsorbances of oil shows no statistical significance. EG saturated firstly by dyes, still has an average adsorption capacity of 35 g/g for SD300 oil, and it does not change with the initial dyes concentration. SEM photos illustrate the adsorption of oil on EG is mainly filling, In the adsorption of dyes, there is severe breakage of the V-type pore and shrinkage of the particle. Kinetic difference is analyzed also.
基金Supported by the National Natural Science Foundation of China(No.51105009)the National Science and Technology Support Program(No.2012BAF13B05)
文摘In order to research how the size of the ink flow channel is affected by the interaction of adjacent ink areas,according to the method of fluid-solid interaction,this paper analyzes the size of the ink flow channel of two ink rollers' rotation.Firstly,this paper simulates the situation of only one ink area.Secondly,this paper simulates the situation of five adjacent ink areas.Then,through comparing the simulation results of two above situations,it' s obvious that the interaction of adjacent ink areas has big effects on the ink pressure and the size of ink flow channel.At last,this paper gets the main factor that affects the size of ink flow channel in the different situations.
文摘With spreading and deepening of intangible cultural heritage protection movement in this century, Chinese ink art is among the Masterpieces of the Oral and Intangible Heritage of Humanity. Institutions of higher education is an academic heritage, culture, communication, personnel training platform and carrier, we assume an important role in the protection of heritage and ink art. Modem design teaching is in order to better local cultural heritage, but also to change their design education, more and more traditional elements are used in the classroom student design works. This paper aims to cultural connotations of traditional Chinese ink painting itself carrying elements and aesthetic charm of the excavation, analysis and sorting, which will be teaching in their designs into modem art. The contemporary art and design are to make cultural connotation and aesthetic meaning, making a good combination of tradition and art.
文摘PVA (Polyvinyl Alcohol) is a water soluble organic dielectric, easily solution processed to fabricate films by spin coating, dip coating or inkjet printing. It has been used as a dielectric layer in OTFTs (organic thin film transistors), and its dielectric constant is around 3.5-10. For OTFTs operating at lower voltage, it is desirable to increase the dielectric constant. Here, we report a technique to incorporate upto 50 wt% of TiO2 nanoparticles (15-25 nm) in PVA to increase its dielectric constant. Rutile phase of TiO2 is used, because of its higher dielectric constant (e = 114) compared to anatase phase (E = 31). We have made inks containing 10 and 50 wt% (of PVA) TiO2 nanoparticles, which is stable upto six months. PVA-TiO2 dispersions and PVA (without TiO2) were spin coated on indium tin oxide coated polyethylene terephthalate substrate. Film structure was studied using SEM (scanning electron microscopy). Absorption study of the films confirms presence of TiO2 nanoparticles. M-I-M capacitors were fabricated by thermally evaporating aluminium on top of the dielectric films. We observed enhancement in dielectric constant by a factor of 2 for PVA containing 50 wt% TiO2 in comparison to PVA's dielectric constant. There is no concomitant increase in the leakage current.
文摘The past six years (2008-2014) was a prosperous time for exploration and production in the dGOM (deepwater Gulf of Mexico). Recent exploration and production activities can be divided into three major categories: drilling new wildcat wells, appraising and developing newly discovered fields and enhanced oil recovery of mature fields. Seismic imaging, complex geology, high pressure drilling, greater depth, and higher temperature are key challenges for the exploration and production of dGOM reservoirs. Complex geology includes salt-related structures and traps, reservoir compartmentalization, and the sequence stratigraphy of turbidite reservoirs. Turbidite sequence stratigraphy helps the asset team to fred the best target intervals. Sheet and channelized sandstones with good downdip aquifer support are preferred reservoir conditions. All the drilling, development and production challenges are related to high pressure, greater depth, higher temperature and lack of existing field analogs. Various IOR (improved oil recovery) methods are studied and applied in the development stage of the Wilcox fields, which have an average primary recovery factor of 10%-15%. With ideal tabular reservoir geometry and IOR methods, recovery factor of the Wilcox reservoirs can reach up to 42% of OOIP (origional oil in place) through the field life cycle.
基金Project(ZR2011BL005)supported by the Natural Science Foundation of Shandong Province,China
文摘Graphite nanoplatelets were prepared by a novel magnetic-grinding method using self-made equipments. Under a variant magnetic field, magnetic needles collided at a high rotating speed and exfoliated pristine graphite into graphite nanoplatelets with high efficiency. The obtained graphite nanoplatelets are highly crystalline, and the thickness is less than 10 nm. Moreover, the surface area could reached 738.1 m^2/g with a grinding time of 4 h. Silanized graphite nanoplatelets can disperse well in SG 15W-40 engine oil and serve as lubricant additive. Tribological results indicate that the friction coefficient and wear-scar of the friction pairs are lower than 76% and 41%, respectively, by adding 1.5‰(mass fraction) of silanized graphite nanoplatelets. Notably, the functionalized graphite nanoplatelets can realize large-scale production and commercial application.
文摘The deepwater horizon blowout led to the release of 4.9 million barrels of crude oil into the Gulf of Mexico (GOM). Here the paper analyzes available sediment datasets to determine whether changes in petrogenic contaminants are evident in GOM sediment following the blowout. Locations sampled by EPA (Environmental Protection Agency), British Petroleum (BP) and NOAA (National Oceanic and Atmospheric Administration) were reduced and grouped into 46 similar locations and analyzed. Eleven groups suggested an increase in PAIl (polycyclic aromatic hydrocarbon) and nickel, one group showed a statistically significant increase in Phenanthrene. Four locations were analyzed for time trends and differences between initial and peak concentrations of oil range organics (ORO), diesel range organics (DRO), vanadium and nickel. One location had significant increases in ORO, DRO and vanadium and a suggestive increase in nickel. Correlations between ORO/DRO, ORO/V, ORO/Ni, V/Ni were computed (RE= 0.85, 0.67, 0.64, 0.92, respectively). Overall, the analyses suggest that future monitoring should employ a sampling strategy that coordinates response sampling to previously sampled locations, such that baseline datasets can be used in detection of event associated contamination.
基金Acknowledgements The authors gratefully acknowledge financial support from the the National Natural Science Foundation of China (Grants No. 50933003, 50902073, 50903044, and 20774047), Ministry of Science and Technology of China (Grant No. 2009AA032304, 2011CB932602), Natural Science Foundation of Tianjin City (Grant No. 08JCZDJC25300).
文摘A series of inkjet printing processes have been studied using graphene-based inks. Under optimized conditions, using water-soluble single-layered graphene oxide (GO) and few-layered graphene oxide (FGO), various high image quality patterns could be printed on diverse flexible substrates, including paper, poly(ethylene terephthalate) (PET) and polyimide (PI), with a simple and low-cost inkjet printing technique. The graphene-based patterns printed on plastic substrates demonstrated a high electrical conductivity after thermal reduction, and more importantly, they retained the same conductivity over severe bending cycles. Accordingly, flexible electric circuits and a hydrogen peroxide chemical sensor were fabricated and showed excellent performances, demonstrating the applications of this simple and practical inkjet printing technique using graphene inks. The results show that graphene materials--which can be easily produced on a large scale and possess outstanding electronic properties--have great potential for the convenient fabrication of flexible and low-cost graphene- based electronic devices, by using a simple inkjet printing technique.
基金supported by the Research Funding of the Chinese Academy of Sciences(Grant No.KGZD-EW-T04-4)
文摘The currently available 3D printing still cannot simultaneously deal with the metal and nonmetal inks together due to their huge difference in the melting points and poor compatible printability between each other. Here through introducing the low melting point alloy Bi35In48.6Sn16Zno.4 and silicone rubber as functional inks, we proposed a compatible hybrid 3D printing method for manufacturing the desired device, the supporting substrate and the allied package structure together. The principle of pneumatic-typed 3D printing of multiple inks was described and typical physical properties of the ink Bi35In48.6Sn16Zno.4 were measured. Several key factors dominating the printing quality such as the temperature of the printing head, the air pressure exerted upon the liquid metal ink in the syringe, the moving velocity and the height of the printing head etc. were clarified. A general way of directly printing out 3D structured electronic devices consisting of both metal and nonmetal materials was demonstrated. Such hybrid objects were patterned and formed up layer by layer with Bi35In48.6Sn16Zno.4 alloy and silicone rub- ber which would become solidified after standing for a period of time under room temperature. To illustrate the compatible printability of these printing inks, a three-layer tricolor LED stereo circuit with controlled lighting capability was further man- ufactured and evaluated. The present study opens an important hybrid 3D printing way for directly manufacturing functional and structural end devices in an easy and low cost way.