The efficiency of lithium-carbon dioxide （li–CO2） batteries is limited by the sluggish generation/decomposition kinetics of the discharge products （i.e.,li2CO3and carbon） despite the use of state-of-the-art noble...
The efficiency of lithium-carbon dioxide （li–CO2） batteries is limited by the sluggish generation/decomposition kinetics of the discharge products （i.e.,li2CO3and carbon） despite the use of state-of-the-art noble metal （NM） ***2C2O4has emerged as a promising alternative product;however,the thermodynamic instability of li2C2O4causes it to generally appear as an intermediate in li2CO3pathways rather than a product during ***,using comprehensive first-principles calculations,we report tailoring the discharge products of li–CO2batteries to li2C2O4via single-atom alloy （SAA） engineering,in which NM-doped copper SAAs （NM1Cu） are constructed for *** NM1Cu catalysts display a free-atom-like narrow d-band state and unique charge distribution over the solute NM1atom and the surrounding matrix Cu *** an optimized electronic structure is substantial in Ru1Cu and Ir1Cu,which is conducive to the co-activation and coupling of *** lithiation of*CO2intermediate that breaks the charge symmetry of the central C species can further reduce the kinetic barriers of the C–C *** advantages promote li2C2O4generation on Ru1Cu and Ir1Cu while suppress its subsequent ***,they exhibit low theoretical overpotentials and enable facile delithiation under normal charging *** work proposes a universal principle of manipulating electronic structures to achieve li2C2O4product,which provides practical guidance for the development of li–CO2batteries.
Background Enhanced green fluorescent protein （EGFP） has been an important reporter gene for gene therapy. Human mesenchymal stem cells （hMSCs） are ideal target cells in cell transplantation and tissue engineering...
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Background Enhanced green fluorescent protein （EGFP） has been an important reporter gene for gene therapy. Human mesenchymal stem cells （hMSCs） are ideal target cells in cell transplantation and tissue engineering. We investigated their biological characteristics and differentiation mediated by PLEGFP-N1 retroviral transduction.Methods hMSCs were isolated from human bone marrow by density gradient fractionation and adherence to plastic flasks. Individual colonies were selected and cultured in tissue dishes. Packaging cells PT67 were transfected by PLEGFP-N1 retroviral vector , and hMSCs were transduced by viral supernatant infection. Meanwhile, hMSCs-EGFP were identified by immune phenotypes and whether it could differentiate into osteoblasts or adipocytes under conditioned media was investigated.Results The rate of stably transduced hMSCs-EGFP was up to 96% after being screened by G418. hMSCs-EGFP exhibited fibroblast-like morphological features. Flow cytometric analyses showed that hMSCs-EGFP were positive for CD73, CD105, CD166, CD90 and CD44, but negative for CD34 and CD45. In addition, it could functionally be induced into osteocytes or adipocytes under conditioned media. These biological features of hMSCs-EGFP were consistent with those of hMSCs.Conclusions hMSCs transduced by PLEGFP-N1 retroviral vector can be used in vivo securely because they can maintain their biological characteristics and differentiation. It is a simple and reliable way to trace the changes of hMSCs in vivo by EGFP during cell transplantation and gene therapy.
A dicarbonyl precursor of 9-hydroxy-cembrene-C,8-tetrahydropyranoxy-3,7,11,15- tetramethyl-14-oxo-2E,6E,10E-hexdecatrienal,was prepared from farnesyl acetate via four steps.
A dicarbonyl precursor of 9-hydroxy-cembrene-C,8-tetrahydropyranoxy-3,7,11,15- tetramethyl-14-oxo-2E,6E,10E-hexdecatrienal,was prepared from farnesyl acetate via four steps.
For different kinds of rocks,the collapse range of tunnel was studied in the previously published ***,some tunnels were buried in soils,and test data showed that the strength envelopes of the soils followed power-law ...
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For different kinds of rocks,the collapse range of tunnel was studied in the previously published ***,some tunnels were buried in soils,and test data showed that the strength envelopes of the soils followed power-law failure *** this work,deep buried highway tunnel with large section was taken as objective,and the basic expressions of collapse shape and region were deduced for the highway tunnels in soils,based on kinematical approach and power-law failure *** order to see the effectiveness of the proposed expressions,the solutions presented in this work agree well with previous results if the nonlinear failure criterion is reduced to a linear Mohr-Coulomb failure *** present results are compared with practical projects and tunnel design *** numerical results show that the height and width of tunnel collapse are greatly affected by the nonlinear criterion for the tunnel in soil.
Polybromodiphenyl ethers(PBDEs),the widely used flame retardants,are common contaminants in surface soils at e-waste recycling *** association of PBDEs with soil colloids has been observed,indicating the potential ris...
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Polybromodiphenyl ethers(PBDEs),the widely used flame retardants,are common contaminants in surface soils at e-waste recycling *** association of PBDEs with soil colloids has been observed,indicating the potential risk to groundwater due to colloid-facilitated ***,the extent to which soil colloidsmay enhance the spreading of PBDEs in groundwater is largely ***,we report the co-transport of decabromodiphenyl ester(BDE-209)and soil colloids in saturated porous *** colloids released froma soil sample collected at an e-waste recycling site in Tianjin,China,contain high concentration of PBDEs,with BDE-209 being the most abundant conger(320±30 mg/kg).The colloids exhibit relatively high mobility in saturated sand columns,under conditions commonly observed in groundwater ***,under all the tested conditions(i.e.,varying flow velocity,pH,ionic species and ionic strength),the mass of eluted BDE-209 correlates linearly with that of eluted soil colloids,even though the mobility of the colloids varies markedly depending on the specific hydrodynamic and solution chemistry conditions ***,the mass of BDE-209 retained in the columns also correlates strongly with themass of retained ***,the PBDEs remain bound to soil colloids during transport in porous *** in this study indicate that soil colloidsmay significantly promote the transport of PBDEs in groundwater by serving as an effective *** might be the reason why the highly insoluble and adsorptive PBDEs are found in groundwater at some PBDE-contaminated sites.
Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress *** investigate the correlation between the rock mass properties and maximum horizontal stress,the th...
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Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress *** investigate the correlation between the rock mass properties and maximum horizontal stress,the three-dimensional(3D)stress tensors at 89 measuring points determined using an improved overcoring technique in nine mines in China were adopted,a newly defined characteristic parameter C_(ERP)was proposed as an indicator for evaluating the structural properties of rock masses,and a fuzzy relation matrix was established using the information distribution *** results indicate that both the vertical stress and horizontal stress exhibit a good linear growth relationship with *** is no remarkable correlation between the elastic modulus,Poisson's ratio and depth,and the distribution of data points is scattered and ***,there is no obvious relationship between the rock quality designation(RQD)and *** maximum horizontal stress σ_(H) is a function of rock properties,showing a certain linear relationship with the C_(ERP)at the same *** addition,the overall change trend of σ_(H) determined by the established fuzzy identification method is to increase with the increase of C_(ERP).The fuzzy identification method also demonstrates a relatively detailed local relationship betweenσ_H and C_(ERP),and the predicted curve rises in a fluctuating way,which is in accord well with the measured stress data.
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