Design of a robust catalyst with high activity but the low cost for the hydrodeoxygenation(HDO) of biooils is of great importance to bring the biorefinery concept into reality.In this study,density functional theory(D...Design of a robust catalyst with high activity but the low cost for the hydrodeoxygenation(HDO) of biooils is of great importance to bring the biorefinery concept into reality.In this study,density functional theory(DFT) calculation was adopted to analyze the optimal location of Ni on MoO_(3-x) containing oxygen vacancy,and the corresponding result demonstrated that metallic Ni cluster located at the neighborhood of oxygen vacancies would significantly evoke HDO activity.Enlightened by DFT results,NiMoO_(4) was first hydrothermally synthesized and then employed to fabricate Ni-MoO_(3-x) catalyst via a low-temperature reduction,where Ni escaped from NiMoO_(4) and was reduced to its metallic state.Such an evolution of Ni species also induced the formation of oxygen vacancies around metallic Ni cluster.In the HDO of p-cresol,Ni-MoO_(3-x) exhibited high activity with a complete conversion and a methylcyclohexane selectivity of 99.4% at 150℃.Moreover,the catalyst showed good versatility in catalyzing HDO of diverse lignin-derived oxygenates and lignin oil.2D HSQC NMR,gas chromatograph and elemental analysis of the lignin oil demonstrated the high deoxygenation efficiency and saturation of the benzene ring over Ni-MoO_(3-x).In the upgrading of crude lignin oil,the deoxygenation degree was up to 99%,and the overall carbon yield of the naphthenes was as high as 69.4%.Importantly,the structures and carbon numbers of the naphthene products are similar to jet fuel-range cycloalka nes,which are expected to have a high density that can be blended into jet fuel to raise the range(or payload) of airplanes.This work demonstrates the feasibility for improving the targeted catalytic reactivity by rational tailoring the catalyst structure under the guidance of theoretical analysis,and provides an energy-efficient route for the upgrading of lignin crude oil into valuable naphthenes.展开更多
This study describes a detailed process for obtaining brain glioma stem cells from freshly dissected human brain glioma samples using an immunomagnetic bead technique combined with serum-free media pressure screening....This study describes a detailed process for obtaining brain glioma stem cells from freshly dissected human brain glioma samples using an immunomagnetic bead technique combined with serum-free media pressure screening. Furthermore, the proliferation, differentiation and self-renewal biological features of brain glioma stem cells were identified. Results showed that a small number of CD133 positive tumor cells isolated from brain glioma samples survived as a cell suspension in serum-free media and proliferated. Subcultured CD133 positive cells maintained a potent self-renewal and proliferative ability, and expressed the stem cell-specific markers CD133 and nestin. After incubation with fetal bovine serum, the number of glial fibrillary acidic protein and microtubule associated protein 2 positive cells increased significantly, indicating that the cultured brain glioma stem cells can differentiate into astrocytes and neurons. Western blot analysis showed that tumor suppressor phosphatase and tensin homolog was highly expressed in tumor spheres compared with the differentiated tumor cells. These experimental findings indicate that the immunomagnetic beads technique is a useful method to obtain brain glioma stem cells from human brain tumors.展开更多
Sex control techniques are in great demand for aquaculture because of the huge benefits of mono-sex production.In a previous study on yellow catfish(Tachysurus fulvidraco),intersex individuals were produced by adminis...Sex control techniques are in great demand for aquaculture because of the huge benefits of mono-sex production.In a previous study on yellow catfish(Tachysurus fulvidraco),intersex individuals were produced by administrating 17α-methyltestosterone(MT)or aromatase inhibitor letrozole(LZ).The ovarian and testicular portions of intersexual gonads developed well and were completely separated,arousing our interest in producing self-fertilizable fish and clone-like fish populations.In this study,yellow catfish fry were treated with a combination of MT and LZ at a low dose(5 mg kg^(-1)MT,300 mg kg^(-1)LZ)at a low water temperature(27.0℃,mixed sex-producing temperature,LL group)and a high temperature(33.5◦C,male-producing temperature,HL group),and with a high dose(10 mg kg^(-1) MT,600 mg kg^(-1) LZ)at a low water temperature(LH group),during 12-65 days post-hatching,the critical period of sex differentiation.Both XX and XY intersex were produced with different percentages at the same time through co-treatment with MT and LZ,with or without the help of male-producing temperature.The highest percentage of XY intersex(53%in XY,36%in XX and XY)and XX intersex(47%in XX,25%in XX and XY)was produced in LH and HL groups,respectively.Results of gonadal morphology,histology,and sperm dynamic analysis indicate that some XX and XY intersex individuals were capable of self-fertilization through artificial insemination.The reproductive performance of these intersex individuals was then investigated by injecting spawning agents,dissecting gonads,and artificially fertilizing eggs with their own sperm.The XX,XY,and YY genotypic individuals were produced by the self-fertilization of XY intersex individuals.The present study successfully produced high percentages of XX and XY intersex and conducted self-fertilization by mating the eggs and sperm of a single intersex individual.Self-fertilization in fish will show great potential in aquaculture genetics and breeding,for example,generating highly homozygous(or"clonal")genetic material,producing mono-sex populations,and identifying unknown sex determination modes.In particular,the cloning method of producing genetic materials will be greatly beneficial for maintaining advantageous traits through self-fertilization generation after generation.展开更多
This paper reports the use of a colloidal Pd0 catalysis system to metallize the surface of precipitators separated from coal fly-ash, and metals such as Cu, Ni etc. are deposited on the precipitators surface. Alternat...This paper reports the use of a colloidal Pd0 catalysis system to metallize the surface of precipitators separated from coal fly-ash, and metals such as Cu, Ni etc. are deposited on the precipitators surface. Alternatively, according to the characteristic surface of cenospheres, an Ag coating catalysis system is adopted to first deposit Ag on the cenospheres surface, followed, if necessary, by the deposition of other metals such as Cu, Ni, etc. on the Ag coating to produce monolayer and multilayer metal-coated cenospheres. The surface characteristics and the morphologies of the metal coatings are examined in detail with scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) techniques. It can be shown that the quality of metal coatings derived from the Ag coating catalysis system, is better than that of the colloidal Pd0 catalysis system.展开更多
Continuous-variable quantum key distribution（CVQKD）[1-7]allows two remote parties（Alice and Bob）to share a secret key,even in the presence of an eavesdropper（Eve）with unlimited computational power[8-17].While,a ...Continuous-variable quantum key distribution（CVQKD）[1-7]allows two remote parties（Alice and Bob）to share a secret key,even in the presence of an eavesdropper（Eve）with unlimited computational power[8-17].While,a highly efficient reconciliation protocol[18-21]is crucial in a CVQKDsystem, which can not only extract the errorless secret keys, but also provide a promising way to achieve a long distance CVQKD at a low signal-to-noise ratio （SNR）.展开更多
A major roadblock in achieving substantial building energy reduction is the low performance of old buildings that account for a significant portion of the building energy consumption.Finding low-cost energy retrofit s...A major roadblock in achieving substantial building energy reduction is the low performance of old buildings that account for a significant portion of the building energy consumption.Finding low-cost energy retrofit solutions that do not disrupt occupants’daily life during the retrofitting is the key to successful building energy retrofit initiatives.In this paper,a novel and low-cost exterior wall retrofitting solution is introduced,and its performance in reducing space cooling load was quantitatively evaluated to demonstrate its feasibility and effectiveness.The primary goal of this paper is to provide a quantitative assessment of the cooling-energy savings potential by using the proposed new wall system.The intended retrofitting targets are the large amount of existing cavity-wall buildings located in hot climate regions.The quantification of the before-after heat-flux reduction was conducted through a 3-dimensional steady-state low turbulence computational fluid dynamics(CFD)model,which is validated by benchmarking its prediction against the published experimental case results.The outcomes of the investigation suggest that this simple low-cost solution has great potentials in reducing buildings’summer cooling load in hot climate regions.The applicability of this solution is not limited to retrofitting existing buildings.New energy-efficient building designs can also adopt this solution in their envelope systems.展开更多
A novel fluid dynamics route for scalable and efficient production of graphene and its analogues is demonstrated.Atomic force microscopy and transmission electron microscopy analyses strongly suggest that the bulk lay...A novel fluid dynamics route for scalable and efficient production of graphene and its analogues is demonstrated.Atomic force microscopy and transmission electron microscopy analyses strongly suggest that the bulk layered materials(graphite,BN,MoS2,and WS2)are efficiently exfoliated into individual layers containing mono-and few-layer nanosheets.Computational fluid dynamics analysis indicates that multiple fluid dynamics events are responsible for efficient exfoliation.Cavitation and pressure release can generate normal force for exfoliation.The velocity gradient-induced viscous shear stress,the turbulence-induced Reynolds shear stress,and shear effects stemmed from turbulence and flow channel-induced collisions can generate lateral force for exfoliation,resulting in theses bulk layered materials self-exfoliation down to single or few layers through their intrinsically lateral self-lubricating ability.展开更多
Magnetron sputtering was used to coat various metals on micropowder surfaces. By using this method, the fine particles are better dispersed and can therefore be coated more homogeneously. The micro-powders used includ...Magnetron sputtering was used to coat various metals on micropowder surfaces. By using this method, the fine particles are better dispersed and can therefore be coated more homogeneously. The micro-powders used include cenospheres from fly ash of coal-burning electric power plants （diameter 40-200 μm and particle density 0.7 ± 0.1 g/cm^3）, as well as carborundum particles of different sizes. Aluminum, silver, copper, cobalt and nickel were used as the coating metals. Tests showed that the coated metal film was compact adhering tightly on the base powders, and the coated powders possess adequate flow properties.展开更多
A simple precipitation method was proposed to prepare naproxen micro-particles with different controllable morphologies, using capillary video microscopy to study the precipitation process. Different particle shapes w...A simple precipitation method was proposed to prepare naproxen micro-particles with different controllable morphologies, using capillary video microscopy to study the precipitation process. Different particle shapes were obtained including spherical, platelet-like, stick-like, needle-like, and butterfly-like, all in the micro-size range. It was found that the sizes and morphologies of the formed naproxen particles were sensitive to the nature and concentration of the added surfactant, and depended significantly on processing conditions such as temperature, stirring speed, and initial drug concentration. In addition, pre- cipitation with different surfactant types and concentrations would not affect the crystal microstructure of the formed nanroxen oarticles.展开更多
The preparation of graphene-based conductive inks and their application in the field of flexible electronics have been extensively studied.However,improving the conductivity of the printed patterns always induces the ...The preparation of graphene-based conductive inks and their application in the field of flexible electronics have been extensively studied.However,improving the conductivity of the printed patterns always induces the neglect of the rheological properties of the graphene-based conductive inks or the mechanical properties of the as-printed patterns.In this study,the p-type doping of graphene with CuCl_(2)as the dopant is realized through liquid phase reaction,and the doped graphene powders are used to prepare the graphenebased conductive inks with a conductivity of 3.13×10^(4)S m^(-1).Subsequently,to simplify the preparation of inks,CuCl_(2)is directly added into the graphene-based conductive inks,achieving the p-type doped graphene ink with the conductivity of 3.64×10^(4)S m^(-1).The read range of ultrahigh-frequency radio frequency identification antenna and the temperature of the flexible electrothermal film printed with the CuCl_(2)-doped graphene-based conductive inks can reach 7.15 m and 200℃,respectively when the equivalent isotropically radiated power is equal to 4 W and the input power density is 0.94 W cm^(-2).Moreover,good rheological properties of the conductive inks and high mechanical properties of the printed patterns are also obtained.展开更多
基金supported by the National Key R&D Program of China (2022YFB3805401, 2019YFC1905300)the National Natural Science Foundation of China (22178297)+1 种基金the Hunan Provincial Natural Science Foundation (2022JJ40425, 2022JJ40432)the Process Intensification and Green Chemical Engineering Innovation Team of Hunan Province。
文摘Design of a robust catalyst with high activity but the low cost for the hydrodeoxygenation(HDO) of biooils is of great importance to bring the biorefinery concept into reality.In this study,density functional theory(DFT) calculation was adopted to analyze the optimal location of Ni on MoO_(3-x) containing oxygen vacancy,and the corresponding result demonstrated that metallic Ni cluster located at the neighborhood of oxygen vacancies would significantly evoke HDO activity.Enlightened by DFT results,NiMoO_(4) was first hydrothermally synthesized and then employed to fabricate Ni-MoO_(3-x) catalyst via a low-temperature reduction,where Ni escaped from NiMoO_(4) and was reduced to its metallic state.Such an evolution of Ni species also induced the formation of oxygen vacancies around metallic Ni cluster.In the HDO of p-cresol,Ni-MoO_(3-x) exhibited high activity with a complete conversion and a methylcyclohexane selectivity of 99.4% at 150℃.Moreover,the catalyst showed good versatility in catalyzing HDO of diverse lignin-derived oxygenates and lignin oil.2D HSQC NMR,gas chromatograph and elemental analysis of the lignin oil demonstrated the high deoxygenation efficiency and saturation of the benzene ring over Ni-MoO_(3-x).In the upgrading of crude lignin oil,the deoxygenation degree was up to 99%,and the overall carbon yield of the naphthenes was as high as 69.4%.Importantly,the structures and carbon numbers of the naphthene products are similar to jet fuel-range cycloalka nes,which are expected to have a high density that can be blended into jet fuel to raise the range(or payload) of airplanes.This work demonstrates the feasibility for improving the targeted catalytic reactivity by rational tailoring the catalyst structure under the guidance of theoretical analysis,and provides an energy-efficient route for the upgrading of lignin crude oil into valuable naphthenes.
基金supported in part by the National Natural Science Foundation of China,No.81072072,31070933the guidance project of Xuzhou Science and Technology Bureau,No.X22D1056
文摘This study describes a detailed process for obtaining brain glioma stem cells from freshly dissected human brain glioma samples using an immunomagnetic bead technique combined with serum-free media pressure screening. Furthermore, the proliferation, differentiation and self-renewal biological features of brain glioma stem cells were identified. Results showed that a small number of CD133 positive tumor cells isolated from brain glioma samples survived as a cell suspension in serum-free media and proliferated. Subcultured CD133 positive cells maintained a potent self-renewal and proliferative ability, and expressed the stem cell-specific markers CD133 and nestin. After incubation with fetal bovine serum, the number of glial fibrillary acidic protein and microtubule associated protein 2 positive cells increased significantly, indicating that the cultured brain glioma stem cells can differentiate into astrocytes and neurons. Western blot analysis showed that tumor suppressor phosphatase and tensin homolog was highly expressed in tumor spheres compared with the differentiated tumor cells. These experimental findings indicate that the immunomagnetic beads technique is a useful method to obtain brain glioma stem cells from human brain tumors.
基金supported by the National Natural Science Foundation of China(32273122)Major Science and Technology project of Hubei Province(2023BBA001)+1 种基金Fundamental Research Funds for the Central Universities(2662021SCPY001)the Natural Science Foundation of Hubei Province(2018CFB215).
文摘Sex control techniques are in great demand for aquaculture because of the huge benefits of mono-sex production.In a previous study on yellow catfish(Tachysurus fulvidraco),intersex individuals were produced by administrating 17α-methyltestosterone(MT)or aromatase inhibitor letrozole(LZ).The ovarian and testicular portions of intersexual gonads developed well and were completely separated,arousing our interest in producing self-fertilizable fish and clone-like fish populations.In this study,yellow catfish fry were treated with a combination of MT and LZ at a low dose(5 mg kg^(-1)MT,300 mg kg^(-1)LZ)at a low water temperature(27.0℃,mixed sex-producing temperature,LL group)and a high temperature(33.5◦C,male-producing temperature,HL group),and with a high dose(10 mg kg^(-1) MT,600 mg kg^(-1) LZ)at a low water temperature(LH group),during 12-65 days post-hatching,the critical period of sex differentiation.Both XX and XY intersex were produced with different percentages at the same time through co-treatment with MT and LZ,with or without the help of male-producing temperature.The highest percentage of XY intersex(53%in XY,36%in XX and XY)and XX intersex(47%in XX,25%in XX and XY)was produced in LH and HL groups,respectively.Results of gonadal morphology,histology,and sperm dynamic analysis indicate that some XX and XY intersex individuals were capable of self-fertilization through artificial insemination.The reproductive performance of these intersex individuals was then investigated by injecting spawning agents,dissecting gonads,and artificially fertilizing eggs with their own sperm.The XX,XY,and YY genotypic individuals were produced by the self-fertilization of XY intersex individuals.The present study successfully produced high percentages of XX and XY intersex and conducted self-fertilization by mating the eggs and sperm of a single intersex individual.Self-fertilization in fish will show great potential in aquaculture genetics and breeding,for example,generating highly homozygous(or"clonal")genetic material,producing mono-sex populations,and identifying unknown sex determination modes.In particular,the cloning method of producing genetic materials will be greatly beneficial for maintaining advantageous traits through self-fertilization generation after generation.
文摘This paper reports the use of a colloidal Pd0 catalysis system to metallize the surface of precipitators separated from coal fly-ash, and metals such as Cu, Ni etc. are deposited on the precipitators surface. Alternatively, according to the characteristic surface of cenospheres, an Ag coating catalysis system is adopted to first deposit Ag on the cenospheres surface, followed, if necessary, by the deposition of other metals such as Cu, Ni, etc. on the Ag coating to produce monolayer and multilayer metal-coated cenospheres. The surface characteristics and the morphologies of the metal coatings are examined in detail with scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) techniques. It can be shown that the quality of metal coatings derived from the Ag coating catalysis system, is better than that of the colloidal Pd0 catalysis system.
基金supported by the National Natural Science Foundation of China(Grant Nos.61475075,and 61271238)the Postgraduate Research and Practice Innovation Program of Jiangsu Province(Grant No.KYCX17-0786)
文摘Continuous-variable quantum key distribution（CVQKD）[1-7]allows two remote parties（Alice and Bob）to share a secret key,even in the presence of an eavesdropper（Eve）with unlimited computational power[8-17].While,a highly efficient reconciliation protocol[18-21]is crucial in a CVQKDsystem, which can not only extract the errorless secret keys, but also provide a promising way to achieve a long distance CVQKD at a low signal-to-noise ratio （SNR）.
文摘A major roadblock in achieving substantial building energy reduction is the low performance of old buildings that account for a significant portion of the building energy consumption.Finding low-cost energy retrofit solutions that do not disrupt occupants’daily life during the retrofitting is the key to successful building energy retrofit initiatives.In this paper,a novel and low-cost exterior wall retrofitting solution is introduced,and its performance in reducing space cooling load was quantitatively evaluated to demonstrate its feasibility and effectiveness.The primary goal of this paper is to provide a quantitative assessment of the cooling-energy savings potential by using the proposed new wall system.The intended retrofitting targets are the large amount of existing cavity-wall buildings located in hot climate regions.The quantification of the before-after heat-flux reduction was conducted through a 3-dimensional steady-state low turbulence computational fluid dynamics(CFD)model,which is validated by benchmarking its prediction against the published experimental case results.The outcomes of the investigation suggest that this simple low-cost solution has great potentials in reducing buildings’summer cooling load in hot climate regions.The applicability of this solution is not limited to retrofitting existing buildings.New energy-efficient building designs can also adopt this solution in their envelope systems.
基金supported by the Beijing Natural Science Foundation(2132025)the Special Funds for Co-construction Project of Beijing Municipal Commission of Education+2 种基金the Specialized Research Fund for the Doctoral Program of Higher Education(20131102110016)the Innovation Foundation of BUAA for Ph.D.Graduatesthe Innovative Practice Foundation of BUAA for Graduates(YCSJ01201309)
文摘A novel fluid dynamics route for scalable and efficient production of graphene and its analogues is demonstrated.Atomic force microscopy and transmission electron microscopy analyses strongly suggest that the bulk layered materials(graphite,BN,MoS2,and WS2)are efficiently exfoliated into individual layers containing mono-and few-layer nanosheets.Computational fluid dynamics analysis indicates that multiple fluid dynamics events are responsible for efficient exfoliation.Cavitation and pressure release can generate normal force for exfoliation.The velocity gradient-induced viscous shear stress,the turbulence-induced Reynolds shear stress,and shear effects stemmed from turbulence and flow channel-induced collisions can generate lateral force for exfoliation,resulting in theses bulk layered materials self-exfoliation down to single or few layers through their intrinsically lateral self-lubricating ability.
文摘Magnetron sputtering was used to coat various metals on micropowder surfaces. By using this method, the fine particles are better dispersed and can therefore be coated more homogeneously. The micro-powders used include cenospheres from fly ash of coal-burning electric power plants （diameter 40-200 μm and particle density 0.7 ± 0.1 g/cm^3）, as well as carborundum particles of different sizes. Aluminum, silver, copper, cobalt and nickel were used as the coating metals. Tests showed that the coated metal film was compact adhering tightly on the base powders, and the coated powders possess adequate flow properties.
基金support provided by National Natural Science Foundation of China(Nos.21121064 and 20990224)National Science and Technology Ministry(No.2008BAE64B02)
文摘A simple precipitation method was proposed to prepare naproxen micro-particles with different controllable morphologies, using capillary video microscopy to study the precipitation process. Different particle shapes were obtained including spherical, platelet-like, stick-like, needle-like, and butterfly-like, all in the micro-size range. It was found that the sizes and morphologies of the formed naproxen particles were sensitive to the nature and concentration of the added surfactant, and depended significantly on processing conditions such as temperature, stirring speed, and initial drug concentration. In addition, pre- cipitation with different surfactant types and concentrations would not affect the crystal microstructure of the formed nanroxen oarticles.
基金supported by the Special Funds for the Co-construction Project of Beijing Municipal Commission of Education。
文摘The preparation of graphene-based conductive inks and their application in the field of flexible electronics have been extensively studied.However,improving the conductivity of the printed patterns always induces the neglect of the rheological properties of the graphene-based conductive inks or the mechanical properties of the as-printed patterns.In this study,the p-type doping of graphene with CuCl_(2)as the dopant is realized through liquid phase reaction,and the doped graphene powders are used to prepare the graphenebased conductive inks with a conductivity of 3.13×10^(4)S m^(-1).Subsequently,to simplify the preparation of inks,CuCl_(2)is directly added into the graphene-based conductive inks,achieving the p-type doped graphene ink with the conductivity of 3.64×10^(4)S m^(-1).The read range of ultrahigh-frequency radio frequency identification antenna and the temperature of the flexible electrothermal film printed with the CuCl_(2)-doped graphene-based conductive inks can reach 7.15 m and 200℃,respectively when the equivalent isotropically radiated power is equal to 4 W and the input power density is 0.94 W cm^(-2).Moreover,good rheological properties of the conductive inks and high mechanical properties of the printed patterns are also obtained.
