The metabolism of copper and arsenic in a copper pyrometallurgy process was studied through substance flow analysis method.The mass balance accounts and substance flow charts of copper and arsenic were established,ind...The metabolism of copper and arsenic in a copper pyrometallurgy process was studied through substance flow analysis method.The mass balance accounts and substance flow charts of copper and arsenic were established,indicators including direct recovery,waste recycle ratio,and resource efficiency were used to evaluate the metabolism efficiency of the system.The results showed that,the resource efficiency of copper was 97.58%,the direct recovery of copper in smelting,converting,and refining processes was 91.96%,97.13%and 99.47%,respectively.Meanwhile,for producing 1 t of copper,10 kg of arsenic was carried into the system,with the generation of 1.07 kg of arsenic in flotation tailing,8.50 kg of arsenic in arsenic waste residue,and 0.05 kg of arsenic in waste water.The distribution and transformation behaviors of arsenic in the smelting,converting,and refining processes were also analyzed,and some recommendations for improving copper resource efficiency and pollution control were proposed based on substance flow analysis.展开更多
A soybean oil derived biodiesel was prepared and blended with a conventional No. 0 petrodiesel. The pour points (PP) and the cold filter plugging points (CFPP) of biodiesel blends were evaluated on a low-temperatu...A soybean oil derived biodiesel was prepared and blended with a conventional No. 0 petrodiesel. The pour points (PP) and the cold filter plugging points (CFPP) of biodiesel blends were evaluated on a low-temperature flow tester. Dynamic viscosities of the blends at different temperatures and different shear rates were measured on a rotary rheometer. The crystal morphologies of biodiesel blends at low temperatures were analyzed using a polarizing microscope. The results indicated that blended fuels demonstrated slight decrease in PPs and CFPPs as compared with those of neat soybean oil derived biodiesel and pure petrodiesel. Below the temperatures of PPs or CFPPs, the dynamic viscosity of biodiesel blends dramatically increased with a decreasing temperature, but decreased with an increasing shear rate, so that biodiesel blends exhibited non-Newtonian behavior. At temperatures higher than PPs or CFPPs, a linear relationship appeared between the dynamic viscosity and shear rate and biodiesel blends became Newtonian fluids. At low temperatures, wax crystals of biodiesel blends grew and agglomerated rapidly. Loss of fluidity for biodiesel blends at low temperatures could therefore be attributed on one hand to the sharp increase of viscosity and on the other hand to the rapid growth and agglomeration of wax crystals.展开更多
In order to solve transport problems of industry solid,firstly,a new applicationnotion of pipeline transport was presented,that is to say,combining pretreatment andtransport with disposal techniques of industry solid ...In order to solve transport problems of industry solid,firstly,a new applicationnotion of pipeline transport was presented,that is to say,combining pretreatment andtransport with disposal techniques of industry solid waste.Secondly,the integrated dis-posal and transport system for industry solid waste was introduced,in particular,the oper-ating principles,equipment set-up,key technology and technical parameters.Next,thispaper illustrated the application of this integrated system.Such as it can transport coalsludge with sufficiently high solids content(about 72%~77%)and high apparent viscosity(about 1 000~3 000 Pa.s)directly by pipeline having no use for water and addition agent.Generally,the transport distance is about 1 000 m.This system has been successfullyused in innocuous disposition and efficient utilization of other industrial byproducts or solidwastes,such as city sludge and paper making waste.The integrated system causes nopollution to the environment for its complete seal and realizes protecting the environment,conserving the energy,promoting the development of cycling economic.Finally,the paperdiscussed the research works that were needed for studying such pipeline transport sys-tem and narrates the relevant condition and application status.展开更多
In order to identify the mixing and segregation behaviors in a mineral processing operation, present study aimed on the hydrodynamics of solid–liquid fluidization. The study was carried out in a fluidization column w...In order to identify the mixing and segregation behaviors in a mineral processing operation, present study aimed on the hydrodynamics of solid–liquid fluidization. The study was carried out in a fluidization column with tapings at different height of the bed to collect the sample. The binary particles considered in this study are hematite(4800 kg/m3) and quartz(2600 kg/m3) at different size fractions in the range of average size 87×10^(-6)m to 400×10^(-6)m. It is observed that for various binary mixtures, both quartz and hematite particles share the equal composition by mass(50%) at a particular height of fluidized bed, referred as ‘‘locus point'' of mixing. Study indicates that the mixing zone volume will increase for a continuous fluidized bed plant operation. It is observed that the number of locus points varies from 1 to 3 signifying their dependency on the size ratios of binary mixture. Whenever, the difference in terminal velocity between quartz and hematite particles approaches to zero, mixing is enhanced.Further, the present study is extended to find the segregation index for the different size ratios of quartz and hematite particles. It is evident that depending on the size ratios, various regions such as complete segregation, partial mixing and complete mixing can be observed.展开更多
Polymers are high molecular weight molecules that provide high viscosity at low concentrations to the media they are inserted. In the oil industry, they are used for enhanced oil recovery and for drilling fluids, wher...Polymers are high molecular weight molecules that provide high viscosity at low concentrations to the media they are inserted. In the oil industry, they are used for enhanced oil recovery and for drilling fluids, where its viscosity is an important factor for a greater efficiency. From all the polymers used by industry, the polyacrylamide and the biopolymer xantham gum are those, which appear significantly in those applications. Taking that into consideration, this work intends to study the effects of the physical, chemical and structural parameters of those polymers in their rheological behaviour, by varying their concentrations from 400 ppm to 2,000 ppm and their temperatures from 298 K to 328 K, which are values similar to those found in the field. For that, a Brookfield Viscometer-Brookfield Engineering Labs rheometer was used. The results acquired showed that the increase on the polyacrylamides ionicity generates and increase on the medium viscosity. For the temperature, its increase causes a reduction of viscosity for the low ionicity polyacrylamides, while increases the viscosity for the high ionicity ones. In the comparative study between xantham gum and polyacrylamides, it was possible to notice that, even though the biopolymer is more complex, its viscosity still is lower when compared to the polyacrylamides.展开更多
To characterize and recognize the debris flow-related deposits,the physico-mechanical performance of four deposits from the Dongyuege(DYG),Shawa(SW),Jiangjia Gully(JJG),and Gengdi(GD)debris flows in southwest China is...To characterize and recognize the debris flow-related deposits,the physico-mechanical performance of four deposits from the Dongyuege(DYG),Shawa(SW),Jiangjia Gully(JJG),and Gengdi(GD)debris flows in southwest China is investigated through laboratory analyses and tests.The four debris-flow materials can all be remolded into coherent,homogeneous cylinders with high densification and strength–porosity of 25%-36%,mean pore-throat radius of 0.46-5.89μm,median pore-throat radius of 0.43-4.28μm,P-wave velocity of 800-1200 m/s,modulus of elasticity of 28-103 MPa,unconfined compressive strength(UCS)of 220-760 kPa,and cohesion of 65-281 kPa.Based on the comparison in slurryability and formability among debris-flow deposits,granular flow deposits,fluvial deposits,residual lateritic clay and loess,whether a sediment can be cast into competent cylinders for physico-mechanical tests can be regarded as a diagnostic evidence of old debris-flow deposits.The discrepancy in physico-mechanical properties among the four debris-flow deposits suggests that the combination of foregoing physico-mechanical parameters can characterize assembling characteristics of debris flow-related sediments including grain size distribution,mineralogy,and accidental detritus.Four deposited sediments above can be surprisingly classified as hard soil-soft rocks according to UCS,and the hard soil-soft rock behaviors can advance the further understanding of debris flows.展开更多
OBJECTIVE To observe the effects expression and activation on biological cancer stem cells. of blocking CD133 gene characteristic of the colon METHODS CD133+ colon cancer stem cells (CCSCs) were separated from EpCA...OBJECTIVE To observe the effects expression and activation on biological cancer stem cells. of blocking CD133 gene characteristic of the colon METHODS CD133+ colon cancer stem cells (CCSCs) were separated from EpCAMhigh CD44+ CCSCs through fluorescenceactivated cell sorting (FACS). The proliferation, the capability of spherical cell formation, neoplasia, and the expression of ABCG2 mRNA of CD133+ CCSCs were observed after the CD133+ CCSCs were infected with LV-CD133shRNA. CD133 negative cells were isolated from EpCAMhigh CD44+ CCSCs with FACS, and the CD133 proteins in CD133- cells were detected with Western blot. RESULTS CD133+ CCSCs were isolated from EpCAMhigh CD44+ CCSCs using FACS, and they accounted for 89.2% in the stem cells. In the experimental group, after the CD133+ CCSCs were knocked down by LV-CD133shRNA RNAi, the growth pattern of the cells in the stem cell culture changed into adherent growth from suspended growth, and couldn't generate spherical cells. Results of MTT assay showed that the CD133+ CCSCs infected with LV-CD133shRNA grew slowly, compared to the cells in the control groups. There was a decrease in the cloning efficiency. The infected cells were transplanted into the BALB/c nude mice. During the observation, no neoplasia was found in the CD133+ cells infected with LV-CD133shRNA. The level of ABCG2 mRNA expression was lowered greatly (P 〈 0.01). CD133- cells were obtained from the EpCAMhigh CD44+ CCSCs using FACS, in which the expression of CD133 protein was positive. CONCLUSION CD133 retains the biological characteristics of the colon cancer stem cells.展开更多
The separate-layer injection in different interlayers and the injection of the same-molecular-weight polymer so- lution in a layer are necessary in the polymer flooding process because of heterogeneous multilayer sand...The separate-layer injection in different interlayers and the injection of the same-molecular-weight polymer so- lution in a layer are necessary in the polymer flooding process because of heterogeneous multilayer sandstone reservoirs in EOR projects. To alleviate the matching problems between the layer permeability and the injected polymer molecular weight, a molecular weight adjusting device with porous medium was designed on the basis of mechanical degradation principle. In terms of four variables (polymer concentration, pore diameter, length of shear component and flow rate ), the theological behavior of hydrolyzed polyacrylamide (HPAM) solu- tion flowing through the device was investigated in detail. The change of these variables is able to control the shear rate of HPAM solutions through ceramic foam, and achieve the desired degree of shear degradation and the final theological parameters-viscosity loss, viscoelasticity and pressure drop. Therefore, a linear relationship between viscosity loss and shearing rate was established so as to obtain the targeted viscosity easily. Field tests in the Daqing Oil Field showed that the polymer molecular weight could drop 20% to 50%. In a word, the results could guide the industrial application of the novel device and the further study of polymer degradation flowing through the porous medium.展开更多
Caenorhabditis elegans (C. elegans) is widely adopted as a model organism for a variety of biological studies including development, genetics and neurobiology. Micro-scale microfluidic technology is capable of handlin...Caenorhabditis elegans (C. elegans) is widely adopted as a model organism for a variety of biological studies including development, genetics and neurobiology. Micro-scale microfluidic technology is capable of handling single or populations of C. elegans in high throughput format and allows for the precise spatial and temporal control of their environment, which is well suited for the study of worms in different aspects. In this review, we highlight the recent advances in microfluidic technology for the analysis of worms ranging from behavioral studies to neurobiology. We believe that microfluidic device can further be applied to study the different aspects of worms, extending from fundamental investigation of behavioral dynamics to more complicated biological processes including neurochemistry and learning behaviors.展开更多
基金financial supports from the National Key R&D Program of China(No.2019YFC1907400)the National Natural Science Foundation of China(Nos.51904351,51620105013)。
文摘The metabolism of copper and arsenic in a copper pyrometallurgy process was studied through substance flow analysis method.The mass balance accounts and substance flow charts of copper and arsenic were established,indicators including direct recovery,waste recycle ratio,and resource efficiency were used to evaluate the metabolism efficiency of the system.The results showed that,the resource efficiency of copper was 97.58%,the direct recovery of copper in smelting,converting,and refining processes was 91.96%,97.13%and 99.47%,respectively.Meanwhile,for producing 1 t of copper,10 kg of arsenic was carried into the system,with the generation of 1.07 kg of arsenic in flotation tailing,8.50 kg of arsenic in arsenic waste residue,and 0.05 kg of arsenic in waste water.The distribution and transformation behaviors of arsenic in the smelting,converting,and refining processes were also analyzed,and some recommendations for improving copper resource efficiency and pollution control were proposed based on substance flow analysis.
基金the financial support of the Natural Science Foundation of Chongqing(project No.CSTC2006BA6031)the Program for New Century Excellent Talents in Chinese Universities(project No.NCET-04-1002)
文摘A soybean oil derived biodiesel was prepared and blended with a conventional No. 0 petrodiesel. The pour points (PP) and the cold filter plugging points (CFPP) of biodiesel blends were evaluated on a low-temperature flow tester. Dynamic viscosities of the blends at different temperatures and different shear rates were measured on a rotary rheometer. The crystal morphologies of biodiesel blends at low temperatures were analyzed using a polarizing microscope. The results indicated that blended fuels demonstrated slight decrease in PPs and CFPPs as compared with those of neat soybean oil derived biodiesel and pure petrodiesel. Below the temperatures of PPs or CFPPs, the dynamic viscosity of biodiesel blends dramatically increased with a decreasing temperature, but decreased with an increasing shear rate, so that biodiesel blends exhibited non-Newtonian behavior. At temperatures higher than PPs or CFPPs, a linear relationship appeared between the dynamic viscosity and shear rate and biodiesel blends became Newtonian fluids. At low temperatures, wax crystals of biodiesel blends grew and agglomerated rapidly. Loss of fluidity for biodiesel blends at low temperatures could therefore be attributed on one hand to the sharp increase of viscosity and on the other hand to the rapid growth and agglomeration of wax crystals.
基金Science and Technology Corporation Innovation Fund of China(02C26211100499) PH.D Program Fund(20020290011)
文摘In order to solve transport problems of industry solid,firstly,a new applicationnotion of pipeline transport was presented,that is to say,combining pretreatment andtransport with disposal techniques of industry solid waste.Secondly,the integrated dis-posal and transport system for industry solid waste was introduced,in particular,the oper-ating principles,equipment set-up,key technology and technical parameters.Next,thispaper illustrated the application of this integrated system.Such as it can transport coalsludge with sufficiently high solids content(about 72%~77%)and high apparent viscosity(about 1 000~3 000 Pa.s)directly by pipeline having no use for water and addition agent.Generally,the transport distance is about 1 000 m.This system has been successfullyused in innocuous disposition and efficient utilization of other industrial byproducts or solidwastes,such as city sludge and paper making waste.The integrated system causes nopollution to the environment for its complete seal and realizes protecting the environment,conserving the energy,promoting the development of cycling economic.Finally,the paperdiscussed the research works that were needed for studying such pipeline transport sys-tem and narrates the relevant condition and application status.
文摘In order to identify the mixing and segregation behaviors in a mineral processing operation, present study aimed on the hydrodynamics of solid–liquid fluidization. The study was carried out in a fluidization column with tapings at different height of the bed to collect the sample. The binary particles considered in this study are hematite(4800 kg/m3) and quartz(2600 kg/m3) at different size fractions in the range of average size 87×10^(-6)m to 400×10^(-6)m. It is observed that for various binary mixtures, both quartz and hematite particles share the equal composition by mass(50%) at a particular height of fluidized bed, referred as ‘‘locus point'' of mixing. Study indicates that the mixing zone volume will increase for a continuous fluidized bed plant operation. It is observed that the number of locus points varies from 1 to 3 signifying their dependency on the size ratios of binary mixture. Whenever, the difference in terminal velocity between quartz and hematite particles approaches to zero, mixing is enhanced.Further, the present study is extended to find the segregation index for the different size ratios of quartz and hematite particles. It is evident that depending on the size ratios, various regions such as complete segregation, partial mixing and complete mixing can be observed.
文摘Polymers are high molecular weight molecules that provide high viscosity at low concentrations to the media they are inserted. In the oil industry, they are used for enhanced oil recovery and for drilling fluids, where its viscosity is an important factor for a greater efficiency. From all the polymers used by industry, the polyacrylamide and the biopolymer xantham gum are those, which appear significantly in those applications. Taking that into consideration, this work intends to study the effects of the physical, chemical and structural parameters of those polymers in their rheological behaviour, by varying their concentrations from 400 ppm to 2,000 ppm and their temperatures from 298 K to 328 K, which are values similar to those found in the field. For that, a Brookfield Viscometer-Brookfield Engineering Labs rheometer was used. The results acquired showed that the increase on the polyacrylamides ionicity generates and increase on the medium viscosity. For the temperature, its increase causes a reduction of viscosity for the low ionicity polyacrylamides, while increases the viscosity for the high ionicity ones. In the comparative study between xantham gum and polyacrylamides, it was possible to notice that, even though the biopolymer is more complex, its viscosity still is lower when compared to the polyacrylamides.
基金Project(41931294)supported by the National Natural Science Foundation of ChinaProjects(U1502232,U1033601)supported by the National Natural Science Foundation of China-Yunnan Joint Fund。
文摘To characterize and recognize the debris flow-related deposits,the physico-mechanical performance of four deposits from the Dongyuege(DYG),Shawa(SW),Jiangjia Gully(JJG),and Gengdi(GD)debris flows in southwest China is investigated through laboratory analyses and tests.The four debris-flow materials can all be remolded into coherent,homogeneous cylinders with high densification and strength–porosity of 25%-36%,mean pore-throat radius of 0.46-5.89μm,median pore-throat radius of 0.43-4.28μm,P-wave velocity of 800-1200 m/s,modulus of elasticity of 28-103 MPa,unconfined compressive strength(UCS)of 220-760 kPa,and cohesion of 65-281 kPa.Based on the comparison in slurryability and formability among debris-flow deposits,granular flow deposits,fluvial deposits,residual lateritic clay and loess,whether a sediment can be cast into competent cylinders for physico-mechanical tests can be regarded as a diagnostic evidence of old debris-flow deposits.The discrepancy in physico-mechanical properties among the four debris-flow deposits suggests that the combination of foregoing physico-mechanical parameters can characterize assembling characteristics of debris flow-related sediments including grain size distribution,mineralogy,and accidental detritus.Four deposited sediments above can be surprisingly classified as hard soil-soft rocks according to UCS,and the hard soil-soft rock behaviors can advance the further understanding of debris flows.
基金The work was supported by a grant from the National Natural Science Foundation of China (No.30970843)
文摘OBJECTIVE To observe the effects expression and activation on biological cancer stem cells. of blocking CD133 gene characteristic of the colon METHODS CD133+ colon cancer stem cells (CCSCs) were separated from EpCAMhigh CD44+ CCSCs through fluorescenceactivated cell sorting (FACS). The proliferation, the capability of spherical cell formation, neoplasia, and the expression of ABCG2 mRNA of CD133+ CCSCs were observed after the CD133+ CCSCs were infected with LV-CD133shRNA. CD133 negative cells were isolated from EpCAMhigh CD44+ CCSCs with FACS, and the CD133 proteins in CD133- cells were detected with Western blot. RESULTS CD133+ CCSCs were isolated from EpCAMhigh CD44+ CCSCs using FACS, and they accounted for 89.2% in the stem cells. In the experimental group, after the CD133+ CCSCs were knocked down by LV-CD133shRNA RNAi, the growth pattern of the cells in the stem cell culture changed into adherent growth from suspended growth, and couldn't generate spherical cells. Results of MTT assay showed that the CD133+ CCSCs infected with LV-CD133shRNA grew slowly, compared to the cells in the control groups. There was a decrease in the cloning efficiency. The infected cells were transplanted into the BALB/c nude mice. During the observation, no neoplasia was found in the CD133+ cells infected with LV-CD133shRNA. The level of ABCG2 mRNA expression was lowered greatly (P 〈 0.01). CD133- cells were obtained from the EpCAMhigh CD44+ CCSCs using FACS, in which the expression of CD133 protein was positive. CONCLUSION CD133 retains the biological characteristics of the colon cancer stem cells.
基金Supported by the Program for Yangtse River Scholars and Innovative Research Terms in Universities(IRT0936)the National Basic Research Program of China(2009CB219905+2 种基金2009CB219907)the Daqing Oilfield Co.Ltd
文摘The separate-layer injection in different interlayers and the injection of the same-molecular-weight polymer so- lution in a layer are necessary in the polymer flooding process because of heterogeneous multilayer sandstone reservoirs in EOR projects. To alleviate the matching problems between the layer permeability and the injected polymer molecular weight, a molecular weight adjusting device with porous medium was designed on the basis of mechanical degradation principle. In terms of four variables (polymer concentration, pore diameter, length of shear component and flow rate ), the theological behavior of hydrolyzed polyacrylamide (HPAM) solu- tion flowing through the device was investigated in detail. The change of these variables is able to control the shear rate of HPAM solutions through ceramic foam, and achieve the desired degree of shear degradation and the final theological parameters-viscosity loss, viscoelasticity and pressure drop. Therefore, a linear relationship between viscosity loss and shearing rate was established so as to obtain the targeted viscosity easily. Field tests in the Daqing Oil Field showed that the polymer molecular weight could drop 20% to 50%. In a word, the results could guide the industrial application of the novel device and the further study of polymer degradation flowing through the porous medium.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (KJCX2-YW-H18)Instrument Research and Development Program of the Chinese Academy of Sciences (YZ200908)the National Natural Science Foundation of China (11161160552)
文摘Caenorhabditis elegans (C. elegans) is widely adopted as a model organism for a variety of biological studies including development, genetics and neurobiology. Micro-scale microfluidic technology is capable of handling single or populations of C. elegans in high throughput format and allows for the precise spatial and temporal control of their environment, which is well suited for the study of worms in different aspects. In this review, we highlight the recent advances in microfluidic technology for the analysis of worms ranging from behavioral studies to neurobiology. We believe that microfluidic device can further be applied to study the different aspects of worms, extending from fundamental investigation of behavioral dynamics to more complicated biological processes including neurochemistry and learning behaviors.