Oxidized asphaltene （OA）, a thermosetting material with plenty of functional groups, is synthesized from asphaltene （A） using HNO3]HzSO4 as the oxidizing agent. Boron, nitrogen co-doped porous carbon （BNC-OA） is...Oxidized asphaltene （OA）, a thermosetting material with plenty of functional groups, is synthesized from asphaltene （A） using HNO3]HzSO4 as the oxidizing agent. Boron, nitrogen co-doped porous carbon （BNC-OA） is prepared by carbonization of the mixture of boric acid and OA at 1173 K in an argon atmosphere. X-ray photoelectron spectroscopy （XPS） characterization reveals that the BNC-OA has a nitrogen content of 3.26 at.% and a boron content of 1.31 at.%, while its oxidation-free counterpart （BNC-SA） has a nitrogen content of 1.61 at.% and a boron content of 3.02 at.%. The specific surface area and total pore volume of BNC-OA are 1103 m2·g^-1 and 0.921 cm3·g^-1, respectively. At a current density of 0.1 A·g^-1, the specific capacitance of BNC-OA is 335 F·g^-1 and the capacitance retention can still reach 83% at 1 A·g^-1. The analysis shows that the superior electrochemical performance of the BNC-OA is attributed to the pseudocapacitance behavior of surface heteroatom functional groups and an abundant pore-structure. Boron, nitrogen co-doped porous carbon is a promising electrode material for supercapacitors.展开更多
The dispersion of the active phase and loading capacity of the Mo species on carbon nanotube （CNT） was studied by the XRD technique. The reducibility properties of Co-Mo catalysts in the oxide state over CNTs were i...The dispersion of the active phase and loading capacity of the Mo species on carbon nanotube （CNT） was studied by the XRD technique. The reducibility properties of Co-Mo catalysts in the oxide state over CNTs were investigated by TPR, while the sulfided Co-Mo/CNT catalysts were characterized by means of the XRD and LRS techniques. The activity and selectivity with respect to the hydrodesulfurization （HDS） performances on carbon nanotube supported Co-Mo catalysts were evaluated. It was found that the main active molybdenum species in the oxide state MoO3/CNT catalysts were MoO2, but not MoO3, as generally expected. The maximum loading before the formation of the bulk phase was lower than 6% （percent by mass, based on MoO3）. TPR studies revealed that the active species in the oxide state Co-Mo/CNT catalysts were reduced more easily at relatively lower temperatures in comparison to those of the Co-Mo/γ-Al2O3 catalysts, indicating that the CNT support promoted or favored the reduction of the active species. The active species of a Co-Mo-0.7/CNT catalyst were more easily reduced than those of the Co-Mo/CNT catalysts with Co/Mo atomic ratios of 0.2, 0.35, and 0.5, respectively, suggesting that the Co/Mo atomic ratio has a great effect on the reducibility of the active species. It was found that the incorporation of cobalt improved the dispersion of the molybdenum species on the support, and a phenomenon of mobilization and re-dispersion had occurred during the sulfurization process, resulting in low valence state Mo3S4 and Co-MoS2.17 active phases. HDS measurements showed that the Co-Mo/CNT catalysts were more active than the Co-Mo/γ-Al2O3 ones for the desulfurization of DBT, and the hydrogenolysis/hydrogenation selectivity of the Co-Mo/CNT catalysts was also much higher than those of the Co-Mo/γ-Al2O3. The Co-Mo/CNT catalyst with a Co/Mo atomic ratio of 0.7 showed the highest activity, whereas the catalyst with a Co/Mo atomic ratio of 0.35 had the highest selectivity.展开更多
A bisphenol epoxy resin was used as modifier to increase the heat resistance of condensed poly-nuclear aromatic （COPNA） resin. The basic properties of COPNA resin and modified resin were characterized by Fourier tra...A bisphenol epoxy resin was used as modifier to increase the heat resistance of condensed poly-nuclear aromatic （COPNA） resin. The basic properties of COPNA resin and modified resin were characterized by Fourier transform infrared spectroscopy （FT-IR）, nuclear magnetic resonance spectroscopy （1H-NMR）, vapor pressure osmometry （VPO） and elemental analysis （EA）. Average structural parameters of resins were calculated by the improved Brown-Ladner method, and heat resistance of resins was tested by thermogravimetric analysis （TGA）. The chemical structure, mechanical properties and heat resistivity of the resin/graphite composites prepared with different resins were compared. The results show that the adhesive property and heat resistance of COPNA resin can be remarkably improved by addition of 5 wt.% epoxy resin. The reason is that the reactions between epoxy groups of epoxy resin and hydroxyl groups of COPNA resin improve the heat resistance and adhesive property of COPNA resin. Electric motor brushes with good mechanical properties and low electrical resistivity were successfully prepared by using the modified resin as binder.展开更多
Intrinsic magmatic processes are considered as critical operators of plate movements. Here we demonstrate the role of extrinsic processes consequent to intrinsic processes as a catalyst for anomalous rapid plate movem...Intrinsic magmatic processes are considered as critical operators of plate movements. Here we demonstrate the role of extrinsic processes consequent to intrinsic processes as a catalyst for anomalous rapid plate movement. The rapid and accelerated flight of the Indian subcontinent since Deccan volca- nism until its collision with Eurasia remains as one of the geological conundrums. Data on seismic to- mography, peninsular geomorphology and inferences on continuum of subcrustal structures are utilized to address this enigma. We propose geomorphic isostasy as the mechanism that has driven this fastest drift ever recorded in geological history. It was initiated by sudden instability after the Deccan volcanism and resultant extensive accumulation of lava pile over continental lithosphere of northern India, northern-eastern tilt due to crustal thickness heterogeneity and subcrustal thermal stratification. The drift was sustained by Carlsberg and Central Indian ridge-push until collision and sediment top loading at northeast thenceforth. These inferences and geomorphic isostasy as a catalytic mechanism necessitate variability of drift rates as integral inputs for any continental scale modeling.展开更多
Peninsular Malaysia is already well known for having rare earth(RE)resources.However,pertinent data and information on upstream RE resources and reserve potential in Malaysia are yet to be established.It is vital to i...Peninsular Malaysia is already well known for having rare earth(RE)resources.However,pertinent data and information on upstream RE resources and reserve potential in Malaysia are yet to be established.It is vital to identify opportunities and challenges for value addition to rare earth elements(REEs)deposits in Malaysia.Therefore,this study evaluates the potential of Malaysian geological formations to serve as repositories for RE resources,such as rare earth minerals(REMs)and REEs,by elucidating the geological processes that are considered critical to the formation of the various deposit types.This paper concisely reviews possible REE mineralization in alkaline igneous rocks,pegmatites,placer deposits:monazite and xenotime,marine sediments,river and lake sediments,ion adsorption clays(IAC)deposits,and shale/coal deposits found in Malaysia.Comparisons between Malaysian deposits revealed that these deposits are potentially enriched with RE resources showing geological formations across the world.The paper reviews the methods and flowsheets used for the recovery of REMs and REEs from primary,secondary as well as alternative resources,with special consideration to the hydrometallurgical procedures comprising of leaching with acids and alkalis tailed by ion exchange,solvent extraction,or precipitation.The REEs ecosystem of Malaysia has also been discussed by considering the latest information from the Malaysian Investment Development Authority(MIDA),the REEs processing center,the Academy of Science of Malaysia(ASM),the People’s Republic of China(PRC),Lynas Malaysia Sdn.Bhd.(Lynas),Ministry of Energy and Natural Resources(NRECC),Jabatan Mineral&Geosains(JMG),Ministry of Science,Technology,and Innovation(MOSTI),and the Malaysian Chamber of Mines.The information on upstream RE resources and recent hydrometallurgical approaches provided in this study will contribute to developing and enhancing midstream and downstream RE-based manufacturing and processing operations in Malaysia.展开更多
Low-pressure dielectric barrier discharge（DBD） TiCl4/O2and N2 plasmas have been used to deposit titanium oxide films at different power supply driving frequencies. A homemade large area low pressure DBD reactor was ...Low-pressure dielectric barrier discharge（DBD） TiCl4/O2and N2 plasmas have been used to deposit titanium oxide films at different power supply driving frequencies. A homemade large area low pressure DBD reactor was applied, characterized by the simplicity of the experimental set-up and a low consumption of feed gas and electric power, as well as being easy to operate. Atomic force microscopy, scanning electron microscopy, energy dispersive spectroscopy,and contact angle measurements have been used to characterize the deposited films. Experimental results show all deposited films are uniform and hydrophilic with a contact angle of about 15 o.Compared to titanium oxide films deposited in TiCl4/O2gas mixtures, those in TiCl4/O2/N2gas mixtures are much more stable. The contact angle of titanium oxide films in TiCl4/O2/N2gas mixtures with the addition of 50% N2 and 20% TiCl4 is still smaller than 20 o, while that of undoped titanium oxide films is larger than 64 owhen they are measured after one week. The low-pressure TiCl4/O2plasmas consist of pulsed glow-like discharges with peak widths of several microseconds, which leads to the uniform deposition of titanium oxide films. Increasing a film thickness over several hundreds of nm leads to the film’s fragmentation due to the over-high film stress. Optical emission spectra（OES） of TiCl4/O2DBD plasmas at various power supply driving frequencies are presented.展开更多
Carbonates undergo a variety of physical,mineralogical,chemical changes during depositional and postdepositional stages that are of interest to exploration geologists and sedimentologists.World over,about 60%of hydroc...Carbonates undergo a variety of physical,mineralogical,chemical changes during depositional and postdepositional stages that are of interest to exploration geologists and sedimentologists.World over,about 60%of hydrocarbon reserves occur in carbonates with the dominant proportion associated with dolomitic reservoirs,in particular fault-associated dolomites which appear to be proven hydrocarbon reservoirs.Dolomitization as the critical diagenetic process thus plays an important role in determining reservoir characteristics and in designing exploration strategies.The buried Paleozoic dolomites exhibit relatively higher porosity than their counterparts,Paleozoic limestones.Fault-associated dolomites are usually targets of hydrocarbon exploration due to their good reservoir quality.High heterogeneity in carbonate reservoirs due to varied porosity types and distribution makes reservoir characterization a daunting task.However,the key elements that control porosity development and evolution in these dolomites remain debatable.Studying the influence of multiphase dolomitization,associated diagenetic events,hydrothermal alteration and their causative thermo-tectonic events on porosity evolution and reservoir quality is essential to understanding the critical processes and controlling factors that result in diverse impacts on reservoir quality.In this paper,an attempt is made to characterize dolomitization in homogeneous carbonate mud and its relationship with porosity evolution and reservoir property.In the field,six facies types excluding host limestone are recognized,which are in turn characterized into seven petrographically recognizable phases,namely the host limestone,early replacement dolomite,sucrosic dolomite,metamorphosed dolomite,late replacement dolomite,brecciated limestone and dolomite and late stage calcite.Mineralogical analyses reveal the dominance of stoichiometric dolomites,followed by calcareous dolomites and magnesium calcites.Among all the field-based facies and petrographic phases,the sucrosic dolomites show appreciable porosity within a range from 4%to 8%,whereas the other phases show either nil or insignificant porosity under megascopic and petrographic observations.Our study confirms that in the process of dolomitization that substantially modifies porosity,dolomitic crystal morphologies play a significant role in enhancing or reducing the porosity.展开更多
Nanogeology is a subject that is a combination of geology and nanoscale science,and it has been a frontier field in recent years.It is also a new subject with the features of intersectionality and multidisciplinary. D...Nanogeology is a subject that is a combination of geology and nanoscale science,and it has been a frontier field in recent years.It is also a new subject with the features of intersectionality and multidisciplinary. Digging deeper into geological problems and nanoscale phenomena helps better revealing the more essential mechanisms and processes in geological science,which is also an evitable path in the development of geology.In this paper,we elaborate the concept,feature and main subdisciplines,and summarize three stages ofnanogeology development from preliminary research in the 1990s to subject formation in China.After summarizing the researchers'achievements in this field,we illustrate some primary research progresses of nanogeology in China as eight subdiseiplines.On the basis of the above content,we propose the development prospect of nanogeology in China.There are many geologic problems with scientific values and economic benefits,such as research of geologic fundamental problems,resource exploration and development,mechanism study and prediction of geological activities (disasters),mechanism research and management of environmental pollution and others.Nanogeology has a great potential in China to solve all of these problems.As a result,the theories and methods of nanogeology will become enriching and advanced.It offers important theoretical basis and technological methods to deal with major issues concerning the national economy and the people's livelihoods,such as the prediction of geological activities,as well as resource dislribution and its exploration and utilization.展开更多
This paper presents a method that is capable of predicting pore structure of coal-based microfiltration carbon membranes. The tubular carbon membranes are prepared from coal samples with different particle size and di...This paper presents a method that is capable of predicting pore structure of coal-based microfiltration carbon membranes. The tubular carbon membranes are prepared from coal samples with different particle size and distribution by using the extrusion method. According to the relationship between properties of coal samples (particle size and distribution) and pore structure parameters of coal-based carbon membranes, the experiential equations of average pore size and porosity are concluded, and the change law of pore size distribution curve is also summarized. The results show pore structure properties of coal-based carbon membranes can be exactly predicted for different separation requirements by adjusting coal particle size and distribution, which allows us to minimize cost and time consuming experiments in the development of coal-based microfiltration membranes.展开更多
In order to more effectively monitor the health of composite structures,a fuzzy fiber sensor has been developed.The fuzzy fiber is a bundle of glass fibers with carbon nanotubes or nanofibers(CNTs or CNFs)grown on the...In order to more effectively monitor the health of composite structures,a fuzzy fiber sensor has been developed.The fuzzy fiber is a bundle of glass fibers with carbon nanotubes or nanofibers(CNTs or CNFs)grown on the surface.The nanotube coating makes the fiber bundle conductive while the small conductive path increases sensitivity.The fuzzy fiber sensor can replace conventional metal foil strain gauges in composite applications.The electrical response of the sensor is monitored in real time to measure strain,vibration,cracking and delamination.Continuous monitoring provides instant notification of any problems.Implementation of this sensor network in a composite can increase service life,decrease maintenance costs and greatly reduce inspection downtime.展开更多
Great attention has recently been drawn to developing cost-effective,high efficiency solar cells to meet the ever increasing demand for clean energy.We have most recently witnessed a breakthrough and a rapid developme...Great attention has recently been drawn to developing cost-effective,high efficiency solar cells to meet the ever increasing demand for clean energy.We have most recently witnessed a breakthrough and a rapid development in solid state,hybrid solar cells using organolead halide perovskites as light harvesters.These semiconductors can not only serve as sensitizer in solid state sensitized solar cells with efficiency up to unprecedented 15%,but also function as both light absorber and hole conductor(or electron conductor)at the same time to display power conversion efficiency above 10%.In this review,we will introduce their operation mechanism,structure,and especially the development of the organolead halide perovskite based solar cells.Based on the achievements that have been made to date,solid state photovoltaic device with superior performance than the present one is highly expected.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.21276045)
文摘Oxidized asphaltene （OA）, a thermosetting material with plenty of functional groups, is synthesized from asphaltene （A） using HNO3]HzSO4 as the oxidizing agent. Boron, nitrogen co-doped porous carbon （BNC-OA） is prepared by carbonization of the mixture of boric acid and OA at 1173 K in an argon atmosphere. X-ray photoelectron spectroscopy （XPS） characterization reveals that the BNC-OA has a nitrogen content of 3.26 at.% and a boron content of 1.31 at.%, while its oxidation-free counterpart （BNC-SA） has a nitrogen content of 1.61 at.% and a boron content of 3.02 at.%. The specific surface area and total pore volume of BNC-OA are 1103 m2·g^-1 and 0.921 cm3·g^-1, respectively. At a current density of 0.1 A·g^-1, the specific capacitance of BNC-OA is 335 F·g^-1 and the capacitance retention can still reach 83% at 1 A·g^-1. The analysis shows that the superior electrochemical performance of the BNC-OA is attributed to the pseudocapacitance behavior of surface heteroatom functional groups and an abundant pore-structure. Boron, nitrogen co-doped porous carbon is a promising electrode material for supercapacitors.
文摘The dispersion of the active phase and loading capacity of the Mo species on carbon nanotube （CNT） was studied by the XRD technique. The reducibility properties of Co-Mo catalysts in the oxide state over CNTs were investigated by TPR, while the sulfided Co-Mo/CNT catalysts were characterized by means of the XRD and LRS techniques. The activity and selectivity with respect to the hydrodesulfurization （HDS） performances on carbon nanotube supported Co-Mo catalysts were evaluated. It was found that the main active molybdenum species in the oxide state MoO3/CNT catalysts were MoO2, but not MoO3, as generally expected. The maximum loading before the formation of the bulk phase was lower than 6% （percent by mass, based on MoO3）. TPR studies revealed that the active species in the oxide state Co-Mo/CNT catalysts were reduced more easily at relatively lower temperatures in comparison to those of the Co-Mo/γ-Al2O3 catalysts, indicating that the CNT support promoted or favored the reduction of the active species. The active species of a Co-Mo-0.7/CNT catalyst were more easily reduced than those of the Co-Mo/CNT catalysts with Co/Mo atomic ratios of 0.2, 0.35, and 0.5, respectively, suggesting that the Co/Mo atomic ratio has a great effect on the reducibility of the active species. It was found that the incorporation of cobalt improved the dispersion of the molybdenum species on the support, and a phenomenon of mobilization and re-dispersion had occurred during the sulfurization process, resulting in low valence state Mo3S4 and Co-MoS2.17 active phases. HDS measurements showed that the Co-Mo/CNT catalysts were more active than the Co-Mo/γ-Al2O3 ones for the desulfurization of DBT, and the hydrogenolysis/hydrogenation selectivity of the Co-Mo/CNT catalysts was also much higher than those of the Co-Mo/γ-Al2O3. The Co-Mo/CNT catalyst with a Co/Mo atomic ratio of 0.7 showed the highest activity, whereas the catalyst with a Co/Mo atomic ratio of 0.35 had the highest selectivity.
基金supported by the National Natural Science Foundation of China (Nos. 51172285, 51372277)the Fundamental Research Funds for the Central Universities (14CX02060A)the Natural Science Foundation of Shandong Province (ZR2011EL030)
文摘A bisphenol epoxy resin was used as modifier to increase the heat resistance of condensed poly-nuclear aromatic （COPNA） resin. The basic properties of COPNA resin and modified resin were characterized by Fourier transform infrared spectroscopy （FT-IR）, nuclear magnetic resonance spectroscopy （1H-NMR）, vapor pressure osmometry （VPO） and elemental analysis （EA）. Average structural parameters of resins were calculated by the improved Brown-Ladner method, and heat resistance of resins was tested by thermogravimetric analysis （TGA）. The chemical structure, mechanical properties and heat resistivity of the resin/graphite composites prepared with different resins were compared. The results show that the adhesive property and heat resistance of COPNA resin can be remarkably improved by addition of 5 wt.% epoxy resin. The reason is that the reactions between epoxy groups of epoxy resin and hydroxyl groups of COPNA resin improve the heat resistance and adhesive property of COPNA resin. Electric motor brushes with good mechanical properties and low electrical resistivity were successfully prepared by using the modified resin as binder.
文摘Intrinsic magmatic processes are considered as critical operators of plate movements. Here we demonstrate the role of extrinsic processes consequent to intrinsic processes as a catalyst for anomalous rapid plate movement. The rapid and accelerated flight of the Indian subcontinent since Deccan volca- nism until its collision with Eurasia remains as one of the geological conundrums. Data on seismic to- mography, peninsular geomorphology and inferences on continuum of subcrustal structures are utilized to address this enigma. We propose geomorphic isostasy as the mechanism that has driven this fastest drift ever recorded in geological history. It was initiated by sudden instability after the Deccan volcanism and resultant extensive accumulation of lava pile over continental lithosphere of northern India, northern-eastern tilt due to crustal thickness heterogeneity and subcrustal thermal stratification. The drift was sustained by Carlsberg and Central Indian ridge-push until collision and sediment top loading at northeast thenceforth. These inferences and geomorphic isostasy as a catalytic mechanism necessitate variability of drift rates as integral inputs for any continental scale modeling.
文摘Peninsular Malaysia is already well known for having rare earth(RE)resources.However,pertinent data and information on upstream RE resources and reserve potential in Malaysia are yet to be established.It is vital to identify opportunities and challenges for value addition to rare earth elements(REEs)deposits in Malaysia.Therefore,this study evaluates the potential of Malaysian geological formations to serve as repositories for RE resources,such as rare earth minerals(REMs)and REEs,by elucidating the geological processes that are considered critical to the formation of the various deposit types.This paper concisely reviews possible REE mineralization in alkaline igneous rocks,pegmatites,placer deposits:monazite and xenotime,marine sediments,river and lake sediments,ion adsorption clays(IAC)deposits,and shale/coal deposits found in Malaysia.Comparisons between Malaysian deposits revealed that these deposits are potentially enriched with RE resources showing geological formations across the world.The paper reviews the methods and flowsheets used for the recovery of REMs and REEs from primary,secondary as well as alternative resources,with special consideration to the hydrometallurgical procedures comprising of leaching with acids and alkalis tailed by ion exchange,solvent extraction,or precipitation.The REEs ecosystem of Malaysia has also been discussed by considering the latest information from the Malaysian Investment Development Authority(MIDA),the REEs processing center,the Academy of Science of Malaysia(ASM),the People’s Republic of China(PRC),Lynas Malaysia Sdn.Bhd.(Lynas),Ministry of Energy and Natural Resources(NRECC),Jabatan Mineral&Geosains(JMG),Ministry of Science,Technology,and Innovation(MOSTI),and the Malaysian Chamber of Mines.The information on upstream RE resources and recent hydrometallurgical approaches provided in this study will contribute to developing and enhancing midstream and downstream RE-based manufacturing and processing operations in Malaysia.
基金supported by National Natural Science Foundation of China(Nos.10875025 and 20803007)Fundamental Research Funds for Central Universities of China(Nos.DC12010116 and DC13010106)Program for Liaoning Excellent Talents in University(LJQ20l3128)
文摘Low-pressure dielectric barrier discharge（DBD） TiCl4/O2and N2 plasmas have been used to deposit titanium oxide films at different power supply driving frequencies. A homemade large area low pressure DBD reactor was applied, characterized by the simplicity of the experimental set-up and a low consumption of feed gas and electric power, as well as being easy to operate. Atomic force microscopy, scanning electron microscopy, energy dispersive spectroscopy,and contact angle measurements have been used to characterize the deposited films. Experimental results show all deposited films are uniform and hydrophilic with a contact angle of about 15 o.Compared to titanium oxide films deposited in TiCl4/O2gas mixtures, those in TiCl4/O2/N2gas mixtures are much more stable. The contact angle of titanium oxide films in TiCl4/O2/N2gas mixtures with the addition of 50% N2 and 20% TiCl4 is still smaller than 20 o, while that of undoped titanium oxide films is larger than 64 owhen they are measured after one week. The low-pressure TiCl4/O2plasmas consist of pulsed glow-like discharges with peak widths of several microseconds, which leads to the uniform deposition of titanium oxide films. Increasing a film thickness over several hundreds of nm leads to the film’s fragmentation due to the over-high film stress. Optical emission spectra（OES） of TiCl4/O2DBD plasmas at various power supply driving frequencies are presented.
基金supported by a Shell Grant from the South East Asia Carbonate Research Laboratory,Universiti Teknologi PETRONAS,Malaysia.
文摘Carbonates undergo a variety of physical,mineralogical,chemical changes during depositional and postdepositional stages that are of interest to exploration geologists and sedimentologists.World over,about 60%of hydrocarbon reserves occur in carbonates with the dominant proportion associated with dolomitic reservoirs,in particular fault-associated dolomites which appear to be proven hydrocarbon reservoirs.Dolomitization as the critical diagenetic process thus plays an important role in determining reservoir characteristics and in designing exploration strategies.The buried Paleozoic dolomites exhibit relatively higher porosity than their counterparts,Paleozoic limestones.Fault-associated dolomites are usually targets of hydrocarbon exploration due to their good reservoir quality.High heterogeneity in carbonate reservoirs due to varied porosity types and distribution makes reservoir characterization a daunting task.However,the key elements that control porosity development and evolution in these dolomites remain debatable.Studying the influence of multiphase dolomitization,associated diagenetic events,hydrothermal alteration and their causative thermo-tectonic events on porosity evolution and reservoir quality is essential to understanding the critical processes and controlling factors that result in diverse impacts on reservoir quality.In this paper,an attempt is made to characterize dolomitization in homogeneous carbonate mud and its relationship with porosity evolution and reservoir property.In the field,six facies types excluding host limestone are recognized,which are in turn characterized into seven petrographically recognizable phases,namely the host limestone,early replacement dolomite,sucrosic dolomite,metamorphosed dolomite,late replacement dolomite,brecciated limestone and dolomite and late stage calcite.Mineralogical analyses reveal the dominance of stoichiometric dolomites,followed by calcareous dolomites and magnesium calcites.Among all the field-based facies and petrographic phases,the sucrosic dolomites show appreciable porosity within a range from 4%to 8%,whereas the other phases show either nil or insignificant porosity under megascopic and petrographic observations.Our study confirms that in the process of dolomitization that substantially modifies porosity,dolomitic crystal morphologies play a significant role in enhancing or reducing the porosity.
文摘Nanogeology is a subject that is a combination of geology and nanoscale science,and it has been a frontier field in recent years.It is also a new subject with the features of intersectionality and multidisciplinary. Digging deeper into geological problems and nanoscale phenomena helps better revealing the more essential mechanisms and processes in geological science,which is also an evitable path in the development of geology.In this paper,we elaborate the concept,feature and main subdisciplines,and summarize three stages ofnanogeology development from preliminary research in the 1990s to subject formation in China.After summarizing the researchers'achievements in this field,we illustrate some primary research progresses of nanogeology in China as eight subdiseiplines.On the basis of the above content,we propose the development prospect of nanogeology in China.There are many geologic problems with scientific values and economic benefits,such as research of geologic fundamental problems,resource exploration and development,mechanism study and prediction of geological activities (disasters),mechanism research and management of environmental pollution and others.Nanogeology has a great potential in China to solve all of these problems.As a result,the theories and methods of nanogeology will become enriching and advanced.It offers important theoretical basis and technological methods to deal with major issues concerning the national economy and the people's livelihoods,such as the prediction of geological activities,as well as resource dislribution and its exploration and utilization.
基金supported by the National Natural Science Foundation of China (Grant Nos. 20276008 and 20776024)Visiting Scholar Foundation of State Key Laboratory of Fine Chemicals in Dalian University of Tech-nology+1 种基金the Scientific Research Project for Higher Education Institutes of Education Department of Liaoning Province (Grant No. 2009A098)Young Teacher Foundation of Dalian Maritime University (Grant No. DLMU-ZL-200817)
文摘This paper presents a method that is capable of predicting pore structure of coal-based microfiltration carbon membranes. The tubular carbon membranes are prepared from coal samples with different particle size and distribution by using the extrusion method. According to the relationship between properties of coal samples (particle size and distribution) and pore structure parameters of coal-based carbon membranes, the experiential equations of average pore size and porosity are concluded, and the change law of pore size distribution curve is also summarized. The results show pore structure properties of coal-based carbon membranes can be exactly predicted for different separation requirements by adjusting coal particle size and distribution, which allows us to minimize cost and time consuming experiments in the development of coal-based microfiltration membranes.
基金supported by US Airforce AFOSR funds under contract number FA9550-09-1-0686.
文摘In order to more effectively monitor the health of composite structures,a fuzzy fiber sensor has been developed.The fuzzy fiber is a bundle of glass fibers with carbon nanotubes or nanofibers(CNTs or CNFs)grown on the surface.The nanotube coating makes the fiber bundle conductive while the small conductive path increases sensitivity.The fuzzy fiber sensor can replace conventional metal foil strain gauges in composite applications.The electrical response of the sensor is monitored in real time to measure strain,vibration,cracking and delamination.Continuous monitoring provides instant notification of any problems.Implementation of this sensor network in a composite can increase service life,decrease maintenance costs and greatly reduce inspection downtime.
基金supported by the‘‘Hun-dred Talents Program’’from the Chinese Academy of Sciences
文摘Great attention has recently been drawn to developing cost-effective,high efficiency solar cells to meet the ever increasing demand for clean energy.We have most recently witnessed a breakthrough and a rapid development in solid state,hybrid solar cells using organolead halide perovskites as light harvesters.These semiconductors can not only serve as sensitizer in solid state sensitized solar cells with efficiency up to unprecedented 15%,but also function as both light absorber and hole conductor(or electron conductor)at the same time to display power conversion efficiency above 10%.In this review,we will introduce their operation mechanism,structure,and especially the development of the organolead halide perovskite based solar cells.Based on the achievements that have been made to date,solid state photovoltaic device with superior performance than the present one is highly expected.
