The objective of electrochemical CO_(2) reduction technologies(ECRs)is notably audacious:to revolutionize the market by generating fuel and essential chemicals at a more competitive price than petrochemicals can offer...The objective of electrochemical CO_(2) reduction technologies(ECRs)is notably audacious:to revolutionize the market by generating fuel and essential chemicals at a more competitive price than petrochemicals can offer,all while prioritizing environmental sustainability.To expedite the commercialization of ECR technology,we discuss here how ECR can reshape the industry landscape through 2e−pathways.展开更多
Polymeric perylene diimide(PDI)has been evidenced as a good candidate for photocatalytic water oxidation,yet the origin of the photocatalytic oxygen evolution activity remains unclear and needs further exploration.Her...Polymeric perylene diimide(PDI)has been evidenced as a good candidate for photocatalytic water oxidation,yet the origin of the photocatalytic oxygen evolution activity remains unclear and needs further exploration.Herein,with crystal and atomic structures of the self-assembled PDI revealed from the X-ray diffraction pattern,the electronic structure is theoretically illustrated by the first-principles density functional theory calculations,suggesting the suitable band structure and the direct electronic transition for efficient photocatalytic oxygen evolution over PDI.It is confirmed that the carbonyl O atoms on the conjugation structure serve as the active sites for oxygen evolution reaction by the crystal orbital Hamiltonian group analysis.The calculations of reaction free energy changes indicate that the oxygen evolution reaction should follow the reaction pathway of H_(2)O→^(*)OH→^(*)O→^(*)OOH→^(*)O_(2)with an overpotential of 0.81 V.Through an in-depth theoretical computational analysis in the atomic and electronic structures,the origin of photocatalytic oxygen evolution activity for PDI is well illustrated,which would help the rational design and modification of polymeric photocatalysts for efficient oxygen evolution.展开更多
Formation condition of high-entropy alloys with solid solution structure was investigated. Seventeen kinds of the high-entropy alloys with different components were prepared, the influencing factors （the comprehensiv...Formation condition of high-entropy alloys with solid solution structure was investigated. Seventeen kinds of the high-entropy alloys with different components were prepared, the influencing factors （the comprehensive atomic radius difference δ, the mixing enthalpy AH and the mixing entropy AS） of phase composition of the alloys were calculated, and the microstructure and phase compositions of alloys were analyzed by using SEM and XRD. The result shows that only the systems with δ≤2.77 and △H≥-8.8 kJ/mol will form high entropy alloy with simple solid solution. Otherwise, intermetallic compounds will exist in the alloys. So, selection of the type of element has important effects on microstructure and properties of high entropy alloys.展开更多
High-loading Pt/C catalysts play an important role in the fabrication of membrane electrode assemblies with thin catalytic layer,which enhance mass transport and maintain the balance of water and heat.Unfortunately,as...High-loading Pt/C catalysts play an important role in the fabrication of membrane electrode assemblies with thin catalytic layer,which enhance mass transport and maintain the balance of water and heat.Unfortunately,as the loading increases,the agglomeration and growth of Pt nanoparticles(NPs)occur,causing unsatisfactory performance.Here,we present an efficient method for preparing of highly dispersed and small-sized Pt/C catalysts with Pt loadings varying from 39.01 wt%to 66.48 wt%through the high-temperature shock technique.The high density and ultrafine(~2.5 nm)Pt NPs are successfully anchored onto Vulcan XC-72R carbon black without the use of additional capping agents or surfactants.The modified carbon supports enhance the affinity for Pt precursors,contributing to loading efficiencies of 95%or more,while also providing abundant sites for the nucleation and fixation of Pt NPs,thus preventing agglomeration.In the context of the hydrogen evolution reaction in acidic media,the as-synthesized high-loading Pt/C catalysts show remarkable activity and stability,outperforming the state-of-the-art commercial Pt/C.This is mainly because the combined effects of ultrasmall and uniform Pt NPs,optimized electronic structure of Pt site,superhydrophilicity and effective anchoring of Pt NPs.The polymer electrolyte membrane electrolyzer integrated with Pt60/OX72R and commercial IrO2 reaches 1 A cm^(-2)at 1.77 V and operates stably for 120 hours with a negligible voltage decay.This new strategy is fast,scalable and cost-effective for large-scale production of metal-supported catalysts,especially for the high-loading ones.展开更多
Objective: To elucidate the relation between human tissue factor pathwayinhibitor-2 (TFPI-2) expression and ovarian tumor migration and invasion. Methods: Human TFPI-2expression vector pBos-Cite-neo/TFPI-2 was transfe...Objective: To elucidate the relation between human tissue factor pathwayinhibitor-2 (TFPI-2) expression and ovarian tumor migration and invasion. Methods: Human TFPI-2expression vector pBos-Cite-neo/TFPI-2 was transfected into ovarian tumor cells line A2780- Afterthe transfected cells were selected by G418, transfected and nontransfected cells were screened forTFPI-2 mRNA and protein by reverse transcription-polymerase chain reaction and Western blotanalysis, respectively. The number of transfected or nontransfected cells passing through membraneof Boyden chamber was counted as the basis assessing tumor cells migratory and invasive behaviors.Results: Expression of mRNA and protein of TFPI-2 was detectable in transfected cells. In invasionassay, the number of TFPI-2-expressing cells to traverse a Matrigel-coated membrane was obviouslydecreased compared with that of nonexpressing cells (59.3±6.5 vs 109.7±5.5, P 【 0.01); While inmigration assay, no significant difference through a noncoated membrane was observed amongtransfected and nontransfected cells (114.7±8.6 vs 127.3±7.1, P 】 0.05). Conclusion: Expression ofTFPI-2 may strongly inhibit the invasive ability of ovarian tumor cells in vitro, but has no effecton the migratory ability which provides an experimental basis for genotherapy of human ovariantumor.展开更多
The nanometer cobalt blue pigments were prepared by microemulsion method. Using dynamic light scattering(DLS) test method, the influences of water content on the size of liquid drop of microemulsion and the liquid dro...The nanometer cobalt blue pigments were prepared by microemulsion method. Using dynamic light scattering(DLS) test method, the influences of water content on the size of liquid drop of microemulsion and the liquid drop of microemulsion on the final diameter of nanometer particle were studied in the course of preparation. Accordingly, the method to control the diameter of nanometer particle by changing water content was established. The nanometer cobalt blue particles were confirmed by XRD and TEM. Color parameters of pigments were determined. The quantum size effect of the pigments was discussed.展开更多
Molecular dynamics simulations were carried out to study the internal energy and microstructure of potassium dihydrogen phosphates （KDP） solution at different temperatures. The water molecule was treated as a simple...Molecular dynamics simulations were carried out to study the internal energy and microstructure of potassium dihydrogen phosphates （KDP） solution at different temperatures. The water molecule was treated as a simple-point-charge model, while a seven-site model for the dihydrogen phosphate ion was adopted. The internal energy functions and the radial distribution functions of the solution were studied in detail. An unusually large local particle number density fluctuation was observed in the system at saturation temperature. It has been found that the specific heat of oversaturated solution is higher than that of unsaturated solution, which indicates the solution experiences a crystallization process below saturation temperature. The radial distribution function between the oxygen atom of water and the hydrogen atom of the dihydrogen phosphate ion shows a very strong hydrogen bond structure. There are strong interactions between potassium cation and oxygen atom of dihydrogen phosphate ion in KDP solution, and much more ion pairs were formed in saturated solution.展开更多
Objective: To investigate the expression levels and significance of TFPI, uPA, uPAR and PAI in malignant patients. Methods: The levels of TFPI, uPA and uPAR were measured by using ELISA and the level of PAI was determ...Objective: To investigate the expression levels and significance of TFPI, uPA, uPAR and PAI in malignant patients. Methods: The levels of TFPI, uPA and uPAR were measured by using ELISA and the level of PAI was determined by method of chromogenic substrates in 44 patients with malignant solid tumors (group A1) and 30 patients with acute leukemia (AL, group A2). Results: The levels of TFPI, uPA, and uPAR in group A1 were higher than those in normal control group (group B). TFPI, uPAR levels in group A2 were higher than those in group B, while the level of PAI in group A2 was lower than that in group B. Among the groups, TFPI was increased in the combined infection group; PAI decreased in the hemorrhage group; TFPI, uPA, uPAR and PAI increased in relapsing and metastasis group; TFPI decreased in one-week dead group, while uPA and uPAR increased. Conclusion: The patients with malignant solid tumor and AL had different anticoagulation or fibrinolysis states. TFPI, uPA, Upar and PAI can be used to evaluate the disease condition and the prognosis.展开更多
A comprehensive single particle model which includes the mesoscale and microscale models was developed to study the influence of particle diameter on mass and heat transfer occurring within a ferrite catalyst during t...A comprehensive single particle model which includes the mesoscale and microscale models was developed to study the influence of particle diameter on mass and heat transfer occurring within a ferrite catalyst during the oxidative dehydrogenation of butene to butadiene process. The verified model can be used to investigate the influence of catalyst diameter on the flow distribution inside the particle. The simulation results demonstrate that the mass fraction gradients of all species, temperature gradient and pressure gradient increase with the increase of the particle diameter. It means that there is a high intraparticle transfer resistance and strong diffusion when applying the large catalysts. The external particle mass transfer resistance is nearly constant under different particle diameters so that the effect of particle diameter at external diffusion can be ignored. A large particle diameter can lead to a high surface temperature, which indicates the external heat transfer resistance. Moreover, the selectivity of reaction may be changed with a variety of particle diameters so that choosing appropriate particle size can enhance the production of butadiene and optimize the reaction process.展开更多
[Objective] This study aimed to uncover the biological characteristics of a parasitical fungus in Chrysosp/enium absconditicapsu/um J. T. Pan leaves. [Method] PDA medium was used to isolate the fungus from C. abscondi...[Objective] This study aimed to uncover the biological characteristics of a parasitical fungus in Chrysosp/enium absconditicapsu/um J. T. Pan leaves. [Method] PDA medium was used to isolate the fungus from C. absconditicapsulum leaves; PDA medium, modified KB medium and Czapek medium were adopted to cultivate the isolated strain. [Result] Colonies of the strain were stretched, white, fedora- shaped with smooth and wavy edges, and showed diameter growth on PDA medi- um, modified KB medium and Czapek medium. At the late stage of culture, the colonies turned into cyanish brown on the above media. Spores were black and born on the surface of colonies on PDA medium with blackened medium. While on modified KB medium and Czapek medium, they were born at the edge of colonies with blackened medium. The spores varied in a wide range of shapes, mostly ob- clavate, sometimes spherical or ellipsoidal. The conidia were muriformly septate with transverse or longitudinal or oblique septations. The pseudo-beaks were short and cylindrical. [Conclusion] According to relevant literatures, the isolated strain is a fungus in Alternaria, Dematiaceae, Hylohomycetales, Hyphomycetes, Deuteromycotina.展开更多
An altemative algorithm for mitigating GPS multipath was presented by integrating unscented Kalman filter （UKF） and wavelet transform with particle filter. Within consideration of particle degeneracy, UKF was taken ...An altemative algorithm for mitigating GPS multipath was presented by integrating unscented Kalman filter （UKF） and wavelet transform with particle filter. Within consideration of particle degeneracy, UKF was taken for drawing particle. To remove the noise from raw data and data processing error, adaptive wavelet filtering with threshold was adopted while data preprocessing and drawing particle. Three algorithms, named EKF-PF, UKF-PF and WM-UKF-PF, were performed for comparison. The proposed WM-UKF-PF algorithm gives better error minimization, and significantly improves performance of multipath mitigation in terms of SNR and coefficient even though it has computation complexity. It is of significance for high-accuracy positioning and non-stationary deformation analysis.展开更多
In this study, the relationship between major meteorological factors and tobacco chemical components in different altitudes of Yongde County, Lincang Region of Yunnan Province was studied using correlation analysis an...In this study, the relationship between major meteorological factors and tobacco chemical components in different altitudes of Yongde County, Lincang Region of Yunnan Province was studied using correlation analysis and path analysis methods.The results showed that there was a difference on meteorological factors in different altitudes, causing different impacts on chemical components of flue-cured tobacco; contents of nicotine and total nitrogen decreased with the rising of altitude, conversely, total sugar and reducing sugar contents increased with the rising trend of altitude, and the differences on the contents of potassium （K） and chlorine（CI）, and the ratio of K to CI in different altitudes were not significant, at the altitude of 1 250-1 450 m, each chemical component indicator was better. The correlation between main meteorological factors and conventional chemical components of tobacco leaves was as follows： contents of reducing sugar and total sugar increased with the increase of rainfall and relative humidity, and decreased with the increase of sunshine duration; nicotine content increased with the increase of accumulated temperature and sunshine duration; total nitrogen （N） content increased with the increase of daily mean temperature and accumulated temperature; sugar-alkali ratio increased with the increase of rainfall. Path analysis showed that the direct effect of sunshine duration on reducing sugar and total sugar of tobacco leaves was faint, but the indirect effect was obvious; meanwhile, the direct and indirect effects of it on nicotine and total N were the greatest.展开更多
文摘The objective of electrochemical CO_(2) reduction technologies(ECRs)is notably audacious:to revolutionize the market by generating fuel and essential chemicals at a more competitive price than petrochemicals can offer,all while prioritizing environmental sustainability.To expedite the commercialization of ECR technology,we discuss here how ECR can reshape the industry landscape through 2e−pathways.
基金supported by National Natural Science Foundation of China(No.523B2070,No.52225606).
文摘Polymeric perylene diimide(PDI)has been evidenced as a good candidate for photocatalytic water oxidation,yet the origin of the photocatalytic oxygen evolution activity remains unclear and needs further exploration.Herein,with crystal and atomic structures of the self-assembled PDI revealed from the X-ray diffraction pattern,the electronic structure is theoretically illustrated by the first-principles density functional theory calculations,suggesting the suitable band structure and the direct electronic transition for efficient photocatalytic oxygen evolution over PDI.It is confirmed that the carbonyl O atoms on the conjugation structure serve as the active sites for oxygen evolution reaction by the crystal orbital Hamiltonian group analysis.The calculations of reaction free energy changes indicate that the oxygen evolution reaction should follow the reaction pathway of H_(2)O→^(*)OH→^(*)O→^(*)OOH→^(*)O_(2)with an overpotential of 0.81 V.Through an in-depth theoretical computational analysis in the atomic and electronic structures,the origin of photocatalytic oxygen evolution activity for PDI is well illustrated,which would help the rational design and modification of polymeric photocatalysts for efficient oxygen evolution.
基金Project(HIT.NSRIF.2009090) supported by Natural Scientific Research Innovation Foundation in Harbin Institute of Technology,China
文摘Formation condition of high-entropy alloys with solid solution structure was investigated. Seventeen kinds of the high-entropy alloys with different components were prepared, the influencing factors （the comprehensive atomic radius difference δ, the mixing enthalpy AH and the mixing entropy AS） of phase composition of the alloys were calculated, and the microstructure and phase compositions of alloys were analyzed by using SEM and XRD. The result shows that only the systems with δ≤2.77 and △H≥-8.8 kJ/mol will form high entropy alloy with simple solid solution. Otherwise, intermetallic compounds will exist in the alloys. So, selection of the type of element has important effects on microstructure and properties of high entropy alloys.
文摘High-loading Pt/C catalysts play an important role in the fabrication of membrane electrode assemblies with thin catalytic layer,which enhance mass transport and maintain the balance of water and heat.Unfortunately,as the loading increases,the agglomeration and growth of Pt nanoparticles(NPs)occur,causing unsatisfactory performance.Here,we present an efficient method for preparing of highly dispersed and small-sized Pt/C catalysts with Pt loadings varying from 39.01 wt%to 66.48 wt%through the high-temperature shock technique.The high density and ultrafine(~2.5 nm)Pt NPs are successfully anchored onto Vulcan XC-72R carbon black without the use of additional capping agents or surfactants.The modified carbon supports enhance the affinity for Pt precursors,contributing to loading efficiencies of 95%or more,while also providing abundant sites for the nucleation and fixation of Pt NPs,thus preventing agglomeration.In the context of the hydrogen evolution reaction in acidic media,the as-synthesized high-loading Pt/C catalysts show remarkable activity and stability,outperforming the state-of-the-art commercial Pt/C.This is mainly because the combined effects of ultrasmall and uniform Pt NPs,optimized electronic structure of Pt site,superhydrophilicity and effective anchoring of Pt NPs.The polymer electrolyte membrane electrolyzer integrated with Pt60/OX72R and commercial IrO2 reaches 1 A cm^(-2)at 1.77 V and operates stably for 120 hours with a negligible voltage decay.This new strategy is fast,scalable and cost-effective for large-scale production of metal-supported catalysts,especially for the high-loading ones.
文摘Objective: To elucidate the relation between human tissue factor pathwayinhibitor-2 (TFPI-2) expression and ovarian tumor migration and invasion. Methods: Human TFPI-2expression vector pBos-Cite-neo/TFPI-2 was transfected into ovarian tumor cells line A2780- Afterthe transfected cells were selected by G418, transfected and nontransfected cells were screened forTFPI-2 mRNA and protein by reverse transcription-polymerase chain reaction and Western blotanalysis, respectively. The number of transfected or nontransfected cells passing through membraneof Boyden chamber was counted as the basis assessing tumor cells migratory and invasive behaviors.Results: Expression of mRNA and protein of TFPI-2 was detectable in transfected cells. In invasionassay, the number of TFPI-2-expressing cells to traverse a Matrigel-coated membrane was obviouslydecreased compared with that of nonexpressing cells (59.3±6.5 vs 109.7±5.5, P 【 0.01); While inmigration assay, no significant difference through a noncoated membrane was observed amongtransfected and nontransfected cells (114.7±8.6 vs 127.3±7.1, P 】 0.05). Conclusion: Expression ofTFPI-2 may strongly inhibit the invasive ability of ovarian tumor cells in vitro, but has no effecton the migratory ability which provides an experimental basis for genotherapy of human ovariantumor.
文摘The nanometer cobalt blue pigments were prepared by microemulsion method. Using dynamic light scattering(DLS) test method, the influences of water content on the size of liquid drop of microemulsion and the liquid drop of microemulsion on the final diameter of nanometer particle were studied in the course of preparation. Accordingly, the method to control the diameter of nanometer particle by changing water content was established. The nanometer cobalt blue particles were confirmed by XRD and TEM. Color parameters of pigments were determined. The quantum size effect of the pigments was discussed.
文摘Molecular dynamics simulations were carried out to study the internal energy and microstructure of potassium dihydrogen phosphates （KDP） solution at different temperatures. The water molecule was treated as a simple-point-charge model, while a seven-site model for the dihydrogen phosphate ion was adopted. The internal energy functions and the radial distribution functions of the solution were studied in detail. An unusually large local particle number density fluctuation was observed in the system at saturation temperature. It has been found that the specific heat of oversaturated solution is higher than that of unsaturated solution, which indicates the solution experiences a crystallization process below saturation temperature. The radial distribution function between the oxygen atom of water and the hydrogen atom of the dihydrogen phosphate ion shows a very strong hydrogen bond structure. There are strong interactions between potassium cation and oxygen atom of dihydrogen phosphate ion in KDP solution, and much more ion pairs were formed in saturated solution.
文摘Objective: To investigate the expression levels and significance of TFPI, uPA, uPAR and PAI in malignant patients. Methods: The levels of TFPI, uPA and uPAR were measured by using ELISA and the level of PAI was determined by method of chromogenic substrates in 44 patients with malignant solid tumors (group A1) and 30 patients with acute leukemia (AL, group A2). Results: The levels of TFPI, uPA, and uPAR in group A1 were higher than those in normal control group (group B). TFPI, uPAR levels in group A2 were higher than those in group B, while the level of PAI in group A2 was lower than that in group B. Among the groups, TFPI was increased in the combined infection group; PAI decreased in the hemorrhage group; TFPI, uPA, uPAR and PAI increased in relapsing and metastasis group; TFPI decreased in one-week dead group, while uPA and uPAR increased. Conclusion: The patients with malignant solid tumor and AL had different anticoagulation or fibrinolysis states. TFPI, uPA, Upar and PAI can be used to evaluate the disease condition and the prognosis.
基金The National Science Foundation of China(No.2157604921576050)the Fundamental Research Funds for the Central Universities(No.2242014K10025)
文摘A comprehensive single particle model which includes the mesoscale and microscale models was developed to study the influence of particle diameter on mass and heat transfer occurring within a ferrite catalyst during the oxidative dehydrogenation of butene to butadiene process. The verified model can be used to investigate the influence of catalyst diameter on the flow distribution inside the particle. The simulation results demonstrate that the mass fraction gradients of all species, temperature gradient and pressure gradient increase with the increase of the particle diameter. It means that there is a high intraparticle transfer resistance and strong diffusion when applying the large catalysts. The external particle mass transfer resistance is nearly constant under different particle diameters so that the effect of particle diameter at external diffusion can be ignored. A large particle diameter can lead to a high surface temperature, which indicates the external heat transfer resistance. Moreover, the selectivity of reaction may be changed with a variety of particle diameters so that choosing appropriate particle size can enhance the production of butadiene and optimize the reaction process.
文摘[Objective] This study aimed to uncover the biological characteristics of a parasitical fungus in Chrysosp/enium absconditicapsu/um J. T. Pan leaves. [Method] PDA medium was used to isolate the fungus from C. absconditicapsulum leaves; PDA medium, modified KB medium and Czapek medium were adopted to cultivate the isolated strain. [Result] Colonies of the strain were stretched, white, fedora- shaped with smooth and wavy edges, and showed diameter growth on PDA medi- um, modified KB medium and Czapek medium. At the late stage of culture, the colonies turned into cyanish brown on the above media. Spores were black and born on the surface of colonies on PDA medium with blackened medium. While on modified KB medium and Czapek medium, they were born at the edge of colonies with blackened medium. The spores varied in a wide range of shapes, mostly ob- clavate, sometimes spherical or ellipsoidal. The conidia were muriformly septate with transverse or longitudinal or oblique septations. The pseudo-beaks were short and cylindrical. [Conclusion] According to relevant literatures, the isolated strain is a fungus in Alternaria, Dematiaceae, Hylohomycetales, Hyphomycetes, Deuteromycotina.
基金Project(51174206)supported by the National Natural Science Foundation of ChinaProject(2013AA12A201)supported by the National Hi-tech Research and Development Program of China+1 种基金Project(2012ZDP08)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(SZBF2011-6-B35)supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),China
文摘An altemative algorithm for mitigating GPS multipath was presented by integrating unscented Kalman filter （UKF） and wavelet transform with particle filter. Within consideration of particle degeneracy, UKF was taken for drawing particle. To remove the noise from raw data and data processing error, adaptive wavelet filtering with threshold was adopted while data preprocessing and drawing particle. Three algorithms, named EKF-PF, UKF-PF and WM-UKF-PF, were performed for comparison. The proposed WM-UKF-PF algorithm gives better error minimization, and significantly improves performance of multipath mitigation in terms of SNR and coefficient even though it has computation complexity. It is of significance for high-accuracy positioning and non-stationary deformation analysis.
文摘In this study, the relationship between major meteorological factors and tobacco chemical components in different altitudes of Yongde County, Lincang Region of Yunnan Province was studied using correlation analysis and path analysis methods.The results showed that there was a difference on meteorological factors in different altitudes, causing different impacts on chemical components of flue-cured tobacco; contents of nicotine and total nitrogen decreased with the rising of altitude, conversely, total sugar and reducing sugar contents increased with the rising trend of altitude, and the differences on the contents of potassium （K） and chlorine（CI）, and the ratio of K to CI in different altitudes were not significant, at the altitude of 1 250-1 450 m, each chemical component indicator was better. The correlation between main meteorological factors and conventional chemical components of tobacco leaves was as follows： contents of reducing sugar and total sugar increased with the increase of rainfall and relative humidity, and decreased with the increase of sunshine duration; nicotine content increased with the increase of accumulated temperature and sunshine duration; total nitrogen （N） content increased with the increase of daily mean temperature and accumulated temperature; sugar-alkali ratio increased with the increase of rainfall. Path analysis showed that the direct effect of sunshine duration on reducing sugar and total sugar of tobacco leaves was faint, but the indirect effect was obvious; meanwhile, the direct and indirect effects of it on nicotine and total N were the greatest.
