A new approach,named production of aryl oxygen-containing compounds from the catalytic pyrolysis of bagasse lignin(BL) over perovskite oxide,was proposed,A series of LaTixFe1-xO3(LTF-x) samples were prepared by the so...A new approach,named production of aryl oxygen-containing compounds from the catalytic pyrolysis of bagasse lignin(BL) over perovskite oxide,was proposed,A series of LaTixFe1-xO3(LTF-x) samples were prepared by the solid state reaction method.The crystal phase and morphology of LTF-x were characterized by XRD and SEM respectively.Catalytic pyrolysis performance of LTF-x was performed by TG-DTG and the distribution patterns of gaseous,liquid and solid products from BL was investigated using a fixed-bed micro-reactor.The optimal reaction conditions were determined:the pyrolysis temperature was 600℃,the mass ratio of mBL:mLTF-0.2 was 3:1,the veloeity of earrier gas was 100 ml·min-1.The gaseous produets were mainly eomposed of CO2,CO,CH4 and CnHm(n=2-4,m=2 n+2 or m=2 n),The main aryl oxygen-containing compounds in liquid products were phenolics,guaiacols,syringols and phenylates,the rest were benzenes,furans,esters and carboxylic acid.The total contents of aryl oxygencontaining compounds were from 62% up to more than 72% under the action of the perovskite.Moreover,the LTF-0.2 sample had nice regenerability.展开更多
The Al-doped Ni2P/AI-SBA-15 catalyst with high hydrodeoxygenation （HDO） activity was synthesized by tem- perature programmed reduction at a relatively low reduction temperature of 400 ℃. The as-prepared catalyst wa...The Al-doped Ni2P/AI-SBA-15 catalyst with high hydrodeoxygenation （HDO） activity was synthesized by tem- perature programmed reduction at a relatively low reduction temperature of 400 ℃. The as-prepared catalyst was characterized by X-ray diffraction （XRD）, H2 temperature-programmed reduction （H2-TPR）, X-ray photoelectron spectroscopy （XPS）, transmission electron microscope （TEM）, NH3 temperature programmed desorption （NH3-TPD）, N2 adsorption-desorption and CO uptake. The effect of AI on benzofuran （BF） HDO performance was investigated. The result indicates that the incorporation of AI into the SBA-15 support can promote the formation of much uniform, smaller, highly dispersed N2P particles on the catalyst. The AI also contrib- utes to suppress the enrichment of P and promote more exposed Ni sites on the surface. In addition, the incorporation of AI can enhance the acid strength. The total deoxygenated product yield over Ni2P/AI-SBA-15 reached 90.3%, which is an increase of 19.4%, when compared with that found for Ni2P/SBA-15 （70.9%）.展开更多
The effects of adding rare earth(RE) metals,such as Ce,Yb and Pr to Ni-S_2O_8^(2-)/ZrO_2-Al_2O_3(Ni-SZA) on the structure of catalysts as well as their isomerization performance were studied.The prepared catalysts wer...The effects of adding rare earth(RE) metals,such as Ce,Yb and Pr to Ni-S_2O_8^(2-)/ZrO_2-Al_2O_3(Ni-SZA) on the structure of catalysts as well as their isomerization performance were studied.The prepared catalysts were characterized by XRD,BET,FT-IR,Py-IR,and H_2-TPR,The results showed that the addition of RE metals can increase the strength and amounts of the acid sites,improve the redox properties of catalysts.The Yb-Ni-SZA catalyst showed the best redox properties,which could provide enough metallic sites.In addition,it provided the largest amounts of weak and moderately strong acid sites.Among RE metals modified Ni-SZA catalyst,Yb-Ni-SZA exhibited the highest isopentane yield of 61.7%at 160 °C.The optimum isomerization catalytic performance of the catalysts decreased in the order of Yb-Ni-SZA > Pr-Ni-SZA > Ni-SZA > Ce-Ni-SZA.展开更多
Highly active MCM-41 supported nickel phosphide catalysts for hydrodesulfurization （HDS） were synthesized by two different phosphorus sources, in which the surface of Ni2P catalysts were modified by air instead of b...Highly active MCM-41 supported nickel phosphide catalysts for hydrodesulfurization （HDS） were synthesized by two different phosphorus sources, in which the surface of Ni2P catalysts were modified by air instead of being passivated by O2/N2 mixture. In addition, the catalysts need not be activated with flowing H2 （30 ml·min^-1） at 500℃ for 2 h prior to reaction as traditional method. X-ray diffraction （XRD）, X-ray photoelectro spectroscopy （XPS）, N2-adsorption specific surface area measurements and CO chemisorption were used to characterize the resulting catalysts. The effect of modification with air on the surface of the catalysts for HDS performance was investigated. Results showed that the surface modification with air can promote the formation of smaller Ni2P particles and more active Ni sites on surface of catalysts. At 3.0 MPa and 613 K, the dibenzothiophene （DBT） conversion of the catalysts modified with air was 98.7%, which was 7.1% higher than that of catalyst passivated by O2/N2 mixture. The higher activities of Ni2P（x）/M41-O catalysts can be attributed to the smaller Ni2P particles sizes and the increased hydrogen dissociation activity due to the surface modification.展开更多
In order to generate transgenic donor cells for nuclear transfer, bovine fetal fibroblasts were isolated in vitro and transfected with the eukaryotic expression vector pSRA-EGFP-Ipr1. The mouse Ipr1 gene and human SR-...In order to generate transgenic donor cells for nuclear transfer, bovine fetal fibroblasts were isolated in vitro and transfected with the eukaryotic expression vector pSRA-EGFP-Ipr1. The mouse Ipr1 gene and human SR-A promoter were successfully cloned and then used to construct this macrophage-specific eukaryotic expression vector. Bovine fetal fibroblasts in stable primary culture (4th passage) were transfected with pSRA-EGFP-Ipr1 by electroporation. Fluorescence from GFP was observed after 24h. Transgenic cells were selected using G418 and the resultant monoclones were picked and expanded. The transgenic cells, at the 9 th passage, were evaluated by PCR and flow cytometry. The inserted Ipr1 was confirmed by PCR, indicating stable integration of the transgene into the genome and cells had normal karyotypes and very good appearance, which indicate no deleterious result of the transgenesis. In conclusion, the cells obtained could be used as donor cells for nuclear transfer for further research of transgenic cattle.展开更多
The non-noble metal modified sulfated zirconia was found easy to deactivate.Herein,highly active and highly stable non-noble core-shell Ni-S_(2)O_(8)^(2−)/Al_(2)O_(3)@ZrO_(2) catalysts(Ni-SA@Z-x,x=Al content in wt%)ha...The non-noble metal modified sulfated zirconia was found easy to deactivate.Herein,highly active and highly stable non-noble core-shell Ni-S_(2)O_(8)^(2−)/Al_(2)O_(3)@ZrO_(2) catalysts(Ni-SA@Z-x,x=Al content in wt%)have been successfully prepared and investigated for n-pentane isomerization.The results showed that the core-shell Ni-SA@Z-30 provided a sustained high isopentane yield(63.1%)with little or no deactivation within 5000 min at a mild reaction pressure of 2.0 MPa,which can be attributed to the following factors:(i)carbon deposition was greatly suppressed by the large pore size and huge pore volume;(ii)the loss of sulfur entities was suppressed because the small and highly dispersed tetragonal ZrO_(2) particles can bond with the S species strongly;(iii)strong Brønsted acidity can be maintained well after the isomerization.The pore structures and acid nature of the core-shell Ni-SA@Z-x are entirely different from those of the normal structure Ni-S_(2)O_(8)^(2−)/ZrO_(2)-Al_(2)O_(3),even though the Al content and the compositions of the individual components are the same.The Al_(2)O_(3)cores endow the catalysts with high internal surface area and high mechanical strength.Meanwhile,the ZrO_(2) shell,which consists of more and smaller tetragonal ZrO_(2) particles because of the large surface area of the Al_(2)O_(3)core,promotes the formation of more stable sulfur species and stronger binding sites.展开更多
Oxidative desulfurization from fuel oil is one of the important methods for deep desulfurization.The development of efficient oxidative desulfurization catalysts is crucial for improving the desulfurization performanc...Oxidative desulfurization from fuel oil is one of the important methods for deep desulfurization.The development of efficient oxidative desulfurization catalysts is crucial for improving the desulfurization performance.Successful encapsulation of phosphotungstic acid(HPW)and ionic liquid(BMImBr)inside the mesoporous cages of MIL-101(Cr)was accomplished through a combination of“bottle around ship”and“ship in bottle”methods.The obtained BMImPW@MIL-101(Cr)composite was characterized by XRD,FTIR,BET,SEM,XPS and ICP methods.Results indicated that the BMImPW@MIL-101(Cr)composites with PW^(3−) loading of 23.1–50.7 wt%were obtained,demonstrating that the“bottle around ship”method is beneficial to make full use of nanocages of MIL-101(Cr)to obtain expected high loading of active PW^(3−) .The BMImPW@MIL-101(Cr)exhibits excellent reusability with no evidence of leaching of active PW^(3−) and BMIm^(+),and well-preserved structure after successive cycles of regeneration and reuse.The significantly improved stability of BMImPW@MIL-101(Cr)as compared to HPW@MIL-101(Cr)is possibly because the leaching of the active PW^(3−) −sites can be greatly suppressed by forming large size of BMImPW owing to introduction of BMIm^(+)cation.The BMImPW@MIL-101(Cr)exhibited excellent catalytic activity for solvent free oxidative desulfurization of refractory sulfides.The enhanced oxidative desulfurization activity as compared to HPW@MIL-101(Cr)can be explained by the intimate contact of sulfides with active PW^(3−) sites owing the strong attraction of BMIm^(+)cation with the sulfides.展开更多
With the deployment of more wireless applications, spectrum scarcity becomes an issue in many countries. Recent reports show that the reason for this spectrum shortage is the underutilization of some spectrum re-sourc...With the deployment of more wireless applications, spectrum scarcity becomes an issue in many countries. Recent reports show that the reason for this spectrum shortage is the underutilization of some spectrum re-sources. Fortunately, the emergence of open spectrum and dynamic spectrum assess (DSA) technology in cognitive radio networks relieves this problem. In this paper, we propose a novel DSA-driven cognitive MAC protocol to achieve highly efficient spectrum usage and QoS provisioning. In the proposed protocol, secondary users are divided into several non-overlapping groups, and all leftover channels are allocated among groups taking the groups’ bandwidth requirements into consideration. Moreover, the allocation of vacant channels can be adjusted dynamically when members join/leave groups or primary users return/leave the current network. Simulations show that the proposed MAC protocol greatly improves the quality of ser-vice for secondary users and maximizes the utilization ratio of spectrum resources.展开更多
基金Supported by the National Natural Science Foundation of China,China(51674089)Heilongjiang Provincial Science Fund for Distinguished Youth Scholar(JC2018002)+2 种基金Heilongjiang Postdoctoral Scientific Research Development Fund of China(LBH-Q16037)the Youth Fund of Northeast Petroleum University(2018QNL-17)Postgraduate Innovative Research Projects of Northeast Petroleum University(YJSCX2017-014NEPU)
文摘A new approach,named production of aryl oxygen-containing compounds from the catalytic pyrolysis of bagasse lignin(BL) over perovskite oxide,was proposed,A series of LaTixFe1-xO3(LTF-x) samples were prepared by the solid state reaction method.The crystal phase and morphology of LTF-x were characterized by XRD and SEM respectively.Catalytic pyrolysis performance of LTF-x was performed by TG-DTG and the distribution patterns of gaseous,liquid and solid products from BL was investigated using a fixed-bed micro-reactor.The optimal reaction conditions were determined:the pyrolysis temperature was 600℃,the mass ratio of mBL:mLTF-0.2 was 3:1,the veloeity of earrier gas was 100 ml·min-1.The gaseous produets were mainly eomposed of CO2,CO,CH4 and CnHm(n=2-4,m=2 n+2 or m=2 n),The main aryl oxygen-containing compounds in liquid products were phenolics,guaiacols,syringols and phenylates,the rest were benzenes,furans,esters and carboxylic acid.The total contents of aryl oxygencontaining compounds were from 62% up to more than 72% under the action of the perovskite.Moreover,the LTF-0.2 sample had nice regenerability.
文摘The Al-doped Ni2P/AI-SBA-15 catalyst with high hydrodeoxygenation （HDO） activity was synthesized by tem- perature programmed reduction at a relatively low reduction temperature of 400 ℃. The as-prepared catalyst was characterized by X-ray diffraction （XRD）, H2 temperature-programmed reduction （H2-TPR）, X-ray photoelectron spectroscopy （XPS）, transmission electron microscope （TEM）, NH3 temperature programmed desorption （NH3-TPD）, N2 adsorption-desorption and CO uptake. The effect of AI on benzofuran （BF） HDO performance was investigated. The result indicates that the incorporation of AI into the SBA-15 support can promote the formation of much uniform, smaller, highly dispersed N2P particles on the catalyst. The AI also contrib- utes to suppress the enrichment of P and promote more exposed Ni sites on the surface. In addition, the incorporation of AI can enhance the acid strength. The total deoxygenated product yield over Ni2P/AI-SBA-15 reached 90.3%, which is an increase of 19.4%, when compared with that found for Ni2P/SBA-15 （70.9%）.
基金Supported by the Technology Risk Innovation Foundation of China National Petroleum Corporation(07-06D-01-04-03-02)
文摘The effects of adding rare earth(RE) metals,such as Ce,Yb and Pr to Ni-S_2O_8^(2-)/ZrO_2-Al_2O_3(Ni-SZA) on the structure of catalysts as well as their isomerization performance were studied.The prepared catalysts were characterized by XRD,BET,FT-IR,Py-IR,and H_2-TPR,The results showed that the addition of RE metals can increase the strength and amounts of the acid sites,improve the redox properties of catalysts.The Yb-Ni-SZA catalyst showed the best redox properties,which could provide enough metallic sites.In addition,it provided the largest amounts of weak and moderately strong acid sites.Among RE metals modified Ni-SZA catalyst,Yb-Ni-SZA exhibited the highest isopentane yield of 61.7%at 160 °C.The optimum isomerization catalytic performance of the catalysts decreased in the order of Yb-Ni-SZA > Pr-Ni-SZA > Ni-SZA > Ce-Ni-SZA.
基金Supported by the National Natural Science Foundation of China(21276048)the Project of Education Department of Heilongjiang Province,China(12541060)the Graduate Innovation Project of Northeast Petroleum University,China(YJSCX2016-019NEPU)
文摘Highly active MCM-41 supported nickel phosphide catalysts for hydrodesulfurization （HDS） were synthesized by two different phosphorus sources, in which the surface of Ni2P catalysts were modified by air instead of being passivated by O2/N2 mixture. In addition, the catalysts need not be activated with flowing H2 （30 ml·min^-1） at 500℃ for 2 h prior to reaction as traditional method. X-ray diffraction （XRD）, X-ray photoelectro spectroscopy （XPS）, N2-adsorption specific surface area measurements and CO chemisorption were used to characterize the resulting catalysts. The effect of modification with air on the surface of the catalysts for HDS performance was investigated. Results showed that the surface modification with air can promote the formation of smaller Ni2P particles and more active Ni sites on surface of catalysts. At 3.0 MPa and 613 K, the dibenzothiophene （DBT） conversion of the catalysts modified with air was 98.7%, which was 7.1% higher than that of catalyst passivated by O2/N2 mixture. The higher activities of Ni2P（x）/M41-O catalysts can be attributed to the smaller Ni2P particles sizes and the increased hydrogen dissociation activity due to the surface modification.
基金supported by A key special project of breeding for disease resistance of PR china(Project No.2008ZX08007-004)
文摘In order to generate transgenic donor cells for nuclear transfer, bovine fetal fibroblasts were isolated in vitro and transfected with the eukaryotic expression vector pSRA-EGFP-Ipr1. The mouse Ipr1 gene and human SR-A promoter were successfully cloned and then used to construct this macrophage-specific eukaryotic expression vector. Bovine fetal fibroblasts in stable primary culture (4th passage) were transfected with pSRA-EGFP-Ipr1 by electroporation. Fluorescence from GFP was observed after 24h. Transgenic cells were selected using G418 and the resultant monoclones were picked and expanded. The transgenic cells, at the 9 th passage, were evaluated by PCR and flow cytometry. The inserted Ipr1 was confirmed by PCR, indicating stable integration of the transgene into the genome and cells had normal karyotypes and very good appearance, which indicate no deleterious result of the transgenesis. In conclusion, the cells obtained could be used as donor cells for nuclear transfer for further research of transgenic cattle.
文摘The non-noble metal modified sulfated zirconia was found easy to deactivate.Herein,highly active and highly stable non-noble core-shell Ni-S_(2)O_(8)^(2−)/Al_(2)O_(3)@ZrO_(2) catalysts(Ni-SA@Z-x,x=Al content in wt%)have been successfully prepared and investigated for n-pentane isomerization.The results showed that the core-shell Ni-SA@Z-30 provided a sustained high isopentane yield(63.1%)with little or no deactivation within 5000 min at a mild reaction pressure of 2.0 MPa,which can be attributed to the following factors:(i)carbon deposition was greatly suppressed by the large pore size and huge pore volume;(ii)the loss of sulfur entities was suppressed because the small and highly dispersed tetragonal ZrO_(2) particles can bond with the S species strongly;(iii)strong Brønsted acidity can be maintained well after the isomerization.The pore structures and acid nature of the core-shell Ni-SA@Z-x are entirely different from those of the normal structure Ni-S_(2)O_(8)^(2−)/ZrO_(2)-Al_(2)O_(3),even though the Al content and the compositions of the individual components are the same.The Al_(2)O_(3)cores endow the catalysts with high internal surface area and high mechanical strength.Meanwhile,the ZrO_(2) shell,which consists of more and smaller tetragonal ZrO_(2) particles because of the large surface area of the Al_(2)O_(3)core,promotes the formation of more stable sulfur species and stronger binding sites.
文摘Oxidative desulfurization from fuel oil is one of the important methods for deep desulfurization.The development of efficient oxidative desulfurization catalysts is crucial for improving the desulfurization performance.Successful encapsulation of phosphotungstic acid(HPW)and ionic liquid(BMImBr)inside the mesoporous cages of MIL-101(Cr)was accomplished through a combination of“bottle around ship”and“ship in bottle”methods.The obtained BMImPW@MIL-101(Cr)composite was characterized by XRD,FTIR,BET,SEM,XPS and ICP methods.Results indicated that the BMImPW@MIL-101(Cr)composites with PW^(3−) loading of 23.1–50.7 wt%were obtained,demonstrating that the“bottle around ship”method is beneficial to make full use of nanocages of MIL-101(Cr)to obtain expected high loading of active PW^(3−) .The BMImPW@MIL-101(Cr)exhibits excellent reusability with no evidence of leaching of active PW^(3−) and BMIm^(+),and well-preserved structure after successive cycles of regeneration and reuse.The significantly improved stability of BMImPW@MIL-101(Cr)as compared to HPW@MIL-101(Cr)is possibly because the leaching of the active PW^(3−) −sites can be greatly suppressed by forming large size of BMImPW owing to introduction of BMIm^(+)cation.The BMImPW@MIL-101(Cr)exhibited excellent catalytic activity for solvent free oxidative desulfurization of refractory sulfides.The enhanced oxidative desulfurization activity as compared to HPW@MIL-101(Cr)can be explained by the intimate contact of sulfides with active PW^(3−) sites owing the strong attraction of BMIm^(+)cation with the sulfides.
文摘With the deployment of more wireless applications, spectrum scarcity becomes an issue in many countries. Recent reports show that the reason for this spectrum shortage is the underutilization of some spectrum re-sources. Fortunately, the emergence of open spectrum and dynamic spectrum assess (DSA) technology in cognitive radio networks relieves this problem. In this paper, we propose a novel DSA-driven cognitive MAC protocol to achieve highly efficient spectrum usage and QoS provisioning. In the proposed protocol, secondary users are divided into several non-overlapping groups, and all leftover channels are allocated among groups taking the groups’ bandwidth requirements into consideration. Moreover, the allocation of vacant channels can be adjusted dynamically when members join/leave groups or primary users return/leave the current network. Simulations show that the proposed MAC protocol greatly improves the quality of ser-vice for secondary users and maximizes the utilization ratio of spectrum resources.
