Laser powder bed fusion(LPBF)is a widely recognized additive manufacturing technology that can fabricate complex components rapidly through layer-by-layer formation.However,there is a paucity of research on the effect...Laser powder bed fusion(LPBF)is a widely recognized additive manufacturing technology that can fabricate complex components rapidly through layer-by-layer formation.However,there is a paucity of research on the effect of laser scanning speed on the cellular microstructure and mechanical properties of martensitic stainless steel.This study systematically investigated the influence of laser scanning speed on the cellular microstructure and mechanical properties of a developed Fe11Cr8Ni5Co3Mo martensitic stainless steel produced by LPBF.The results show that increasing the laser scanning speed from 400 to 1000 mm/s does not lead to a noticeable change in the phase fraction,but it reduces the average size of the cellular microstructure from 0.60 to 0.35μm.The scanning speeds of 400 and 1000 mm/s both had adverse effects on performances of sample,resulting in inadequate fusion and keyhole defects respectively.The optimal scanning speed for fabricating samples was determined to be 800 mm/s,which obtained the highest room temperature tensile strength and elongation,with the ultimate tensile strength measured at(1088.3±2.0)MPa and the elongation of(16.76±0.10)%.Furthermore,the mechanism of the evolution of surface morphology,defects,and energy input were clarified,and the relationship between cellular microstructure size and mechanical properties was also established.展开更多
BACKGROUND Pulmonary tuberculosis(PTB)is prevalent in immunocompromised populations,including patients with hematologic malignancies,human immunodeficiency virus infections,and chronic diseases.Effective treatment for...BACKGROUND Pulmonary tuberculosis(PTB)is prevalent in immunocompromised populations,including patients with hematologic malignancies,human immunodeficiency virus infections,and chronic diseases.Effective treatment for acute promyelocytic leukemia(APL)combined with PTB is lacking.These patients show an extremely poor prognosis.Therefore,studies should establish efficient treatment options to improve patient survival and prognosis.CASE SUMMARY A 60-year-old male with pain in the right side of his chest and a fever for 4 d visited the outpatient department of our hospital.Peripheral blood smear revealed 54%blasts.Following bone marrow examinations,variant APL with TNRC18-RARA fusion gene was diagnosed.Chest computed tomography scan showed bilateral pneumonitis with bilateral pleural effusions,partial atelectasis in the lower lobes of both lungs,and the bronchoalveolar lavage fluid gene X-Pert test was positive,indicative of PTB.Carrimycin,ethambutol(EMB),and isoniazid(INH)were administered since he could not receive chemotherapy as the WBC count decreased continuously.After one week of treatment with carrimycin,the patient recovered from fever and received chemotherapy.Chemotherapy was very effective and his white blood cells counts got back to normal.After being given five months with rifampin,EMB and INH and chemotherapy,the patient showed complete remission from pneumonia and APL.CONCLUSION We report a case of PTB treated successfully with carrimycin with APL that requires chemotherapy.展开更多
By method of the Laplace transform, this arti- cle presents semi-analytical solutions for transient electro- osmotic and pressure-driven flows （EOF/PDF） of two-layer fluids between microparallel plates. The lineariz...By method of the Laplace transform, this arti- cle presents semi-analytical solutions for transient electro- osmotic and pressure-driven flows （EOF/PDF） of two-layer fluids between microparallel plates. The linearized Poisson- Boltzmann equation and the Cauchy momentum equation have been solved in this article. At the interface, the Maxwell stress is included as the boundary condition. By numerical computations of the inverse Laplace transform, the effects of dielectric constant ratio e, density ratio p, pressure ratio p, viscosity ratioμ of layer II to layer I, interface zeta potential difference △ψ, interface charge density jump Q, the ratios of maximum electro-osmotic velocity to pressure velocity , and the normalized pressure gradient B on transient veloc- ity amplitude are presented.We find the velocity amplitude becomes large with the interface zeta potential difference and becomes small with the increase of the viscosity. The ve- locity will be large with the increases of dielectric constant ratio; the density ratio almost does not influence the EOF ve- locity. Larger interface charge density jump leads to a strong jump of velocity at the interface. Additionally, the effects of the thickness of fluid layers （hi and h2） and pressure gradient on the velocity are also investigated.展开更多
Flow behavior of transient mixed electro-osmotic and pressure driven flows (EOF/PDF) through a microannulus is investigated based on a linearized Poisson-Boltzmann equation and Navier-Stokes equation. A semi-analytica...Flow behavior of transient mixed electro-osmotic and pressure driven flows (EOF/PDF) through a microannulus is investigated based on a linearized Poisson-Boltzmann equation and Navier-Stokes equation. A semi-analytical solution of EOF velocity distribution as functions of relevant parameters is derived by Laplace transform method. By numerical computations of inverse Laplace transform, the effects of inner to outer wall zeta potential β, the normalized pressure gradient Ω and the inner to outer radius ratio α on transient EOF velocity are presented.展开更多
With urbanization and the rapid development of social economy,China’s rail transit industry has developed rapidly in recent years.In order to alleviate the pressure of road network,subways provide convenience as they...With urbanization and the rapid development of social economy,China’s rail transit industry has developed rapidly in recent years.In order to alleviate the pressure of road network,subways provide convenience as they are fast and space-saving.Subway stations are major energy consumers of urban power grid due to their large traffic volume and long operation time.On the premise of ensuring operation safety,reducing the energy consumption of subway helps in energy conservation and emission reduction as proposed in the 13th Five-Year Plan.According to the statistics of the energy-saving evaluation report of rail transit engineering,the lighting system accounts for 20%-30%of the total power consumption of the subway station.Due to the single lighting control mode of the lighting system in the subway station,the actual station illumination cannot be reported and adjusted in time,resulting in the waste of lighting energy and high power consumption of the system.Through in-depth research on the intelligent lighting system of subway station,this paper improves the system control,and finally summarizes the optimization scheme of subway station lighting design which can effectively save the power consumption of lighting system.The main contents of this paper are as follows:The research results of this paper can provide effective measures for energy saving of electric lighting in subway stations and reduce electric energy consumption;on the other hand,as an integral part of building lighting energy-saving system,it also has certain guiding significance for the research of building lighting energy-saving.展开更多
Hetero-element doping is a promising strategy to improve the cycling stability of nickel-rich cobalt-free cathodes for the next-generation high energy-density Li ion batteries.To make doping effective,it is important ...Hetero-element doping is a promising strategy to improve the cycling stability of nickel-rich cobalt-free cathodes for the next-generation high energy-density Li ion batteries.To make doping effective,it is important to understand the mechanism of how the dopants regulate the electronic band,lattice parameter adjusting,or hetero-phase formation to achieve high stability.In this study,we investigate LiNi_(0.9)Mn_(0.1)O_(2)cathodes doped with IVB grouping elements via multiple characterization techniques.By utilizing in situ XRD and TEM methods,we found that the stronger Ti-O bond effectively improves the cathode stability via a dual protection mechanism.Specifically,the bulk lattice of cathode is wellpreserved during cycling as a result of the suppressed H_(2)-H_(3)phase transition,while a in situ formed Ti-rich surface layer can prevent continuous surface degradation.As a result,the 5%Ti doped LiNi_(0.9)Mn_(0.1)O_(2)cathode exhibits a high capacity retention of 96%after 100 cycles.Whereas,despite IVB group elements Zr and Hf have stronger bonding energy with oxygen,their larger ionic radii actually impede their diffusion into the cathode,thereby they can not improve the cycling stability.Our findings uncover the functional origin of doped elements with their dynamic modification on cathode structure,providing mechanistic insights into the design of nickel-rich cobalt-free cathodes.展开更多
Interface engineering has been regarded as an effective and noninvasive means to optimize the performance of perovskite solar cells(PSCs).Here,doping engineering of a ZnO electron transport layer(ETL)and CsPbI3/ZnO in...Interface engineering has been regarded as an effective and noninvasive means to optimize the performance of perovskite solar cells(PSCs).Here,doping engineering of a ZnO electron transport layer(ETL)and CsPbI3/ZnO interface engineering via introduction of an interfacial layer are employed to improve the performances of CsPbI3-based PSCs.The results show that when introducing a TiO2 buffer layer while increasing the ZnO layer doping concentration,the open-circuit voltage,power conversion efficiency,and fill factor of the CsPbI3-based PSCs can be improved to 1.31 V,21.06%,and 74.07%,respectively,which are superior to those of PSCs only modified by the TiO2 buffer layer or high-concentration doping of ZnO layer.On the one hand,the buffer layer relieves the band bending and structural disorder of CsPbI3.On the other hand,the increased doping concentration of the ZnO layer improves the conductivity of the TiO2/ZnO bilayer ETL because of the strong interaction between the TiO2 and ZnO layers.However,such phenomena are not observed for those of a PCBM/ZnO bilayer ETL because of the weak interlayer interaction of the PCBM/ZnO interface.These results provide a comprehensive understanding of the CsPbI3/ZnO interface and suggest a guideline to design high-performance PSCs.展开更多
This study investigated differences in the community structure and environmental responses of the bacterial community in sediments of the Bohai Sea.Illumina high-throughput sequencing technology and real-time PCR were...This study investigated differences in the community structure and environmental responses of the bacterial community in sediments of the Bohai Sea.Illumina high-throughput sequencing technology and real-time PCR were used to assay the bacterial 16S rRNA genes in the surface sediments of 13 sampling stations in the Bohai Sea.The results showed that sediments at the majority of the 13 sampling stations were contaminated by heavy metal mercury.The main phyla of bacteria recorded included Proteobacteria(52.92%),Bacteroidetes(11.76%),Planctomycetes(7.39%),Acidobacteria(6.53%)and Chloroflexi(4.97%).The genus with the highest relative abundance was Desulfobulbus(4.99%),which was the dominant genus at most sampling stations,followed by Lutimonas and Halioglobus.The main factors influencing bacterial community structure were total organic carbon,followed by depth and total phosphorus.The content of lead,cadmium,chromium,copper and zinc had a consistent effect on community structure.Arsenic showed a negative correlation with bacterial community structure in most samples,while the impact of mercury on community structure was not significant.The bacterial community in sediment samples from the Bohai Sea was rich in diversity and displayed an increase in diversity from high to low latitudes.The data indicated that the Bohai Sea had abundant microbial resources and was rich in bacteria with the potential to metabolize many types of pollutants.展开更多
Objective:To evaluate the anti-inflammatory activity of Crotalaria ferruginea extract(CFE)and its mechanism.Methods:An intratracheal lipopolysaccharide(LPS)instillationinduced acute lung injury(ALI)model was used to s...Objective:To evaluate the anti-inflammatory activity of Crotalaria ferruginea extract(CFE)and its mechanism.Methods:An intratracheal lipopolysaccharide(LPS)instillationinduced acute lung injury(ALI)model was used to study the antiinflammatory activity of CFE in vivo.The LPS-induced shock model was used to analyze the effect of CFE on survival.LPS-stimulated RAW264.7 cell model was used to investigate the anti-inflammatory activity of CFE in vitro and the effects on mitogen-activated protein kinase(MAPK)or nuclear factor-κB(NF-κB)signaling pathways.Results:CFE administration decreased the number of inflammatory cells,reduced the levels of tumor necrosis factor-α(TNF-α),monocyte chemotactic protein-1(MCP-1),interleukin-6(IL-6),and interferon-γ,and diminished protein content in the bronchoalveolar lavage fluid of mice.CFE also reduced lung wet-to-dry weight ratio,myeloperoxidase,and lung tissue pathological injury.CFE preadministration improved the survival rate of mice challenged with a lethal dose of LPS.CFE reduced LPS-activated RAW264.7 cells to produce nitric oxide,TNF-α,MCP-1,and IL-6.Furthermore,CFE inhibited nuclear translocation and phosphorylation of NF-κB P65,extracellular signal-regulated kinase,c-Jun N-terminal kinases,and P38 MAPKs.Conclusions:CFE exhibits potent anti-inflammatory activity in LPS-induced ALI mice,LPS-shock mice,and RAW264.7 cells,and its mechanism may be associated with the inhibition of NF-κB and MAPK signaling pathways.Crotalaria ferruginea may be a useful therapeutic drug for the treatment of ALI and other respiratory inflammations.展开更多
Sea ice concentration(SIC)is one of the most important indicators when monitoring climate changes in the polar region.With the development of the Chinese satellite technology,the Feng Yun(FY)series has been applied to...Sea ice concentration(SIC)is one of the most important indicators when monitoring climate changes in the polar region.With the development of the Chinese satellite technology,the Feng Yun(FY)series has been applied to retrieve the sea ice parameters in the polar region.In this paper,to improve the SIC retrieval accuracy from the passive microwave(PM)data of the Microwave Radiation Imager(MWRI)aboard on the Feng Yun-3 B(FY-3 B)Satellite,the dynamic tie-point(DT)Arctic Radiation and Turbulence Interaction Study(ARTIST)Sea Ice(ASI)(DT-ASI)SIC retrieval algorithm is applied and obtained Arctic SIC data for nearly 10 a(from November 18,2010 to August 19,2019).Also,by applying a land spillover correction scheme,the erroneous sea ice along coastlines in melt season is removed.The results of FY-3 B/DT-ASI are obviously improved compared to that of FY-3 B/NT2(NASA-Team2)in both SIC and sea ice extent(SIE),and are highly consistent with the results of similar products of AMSR2(Advanced Microwave Scanning Radiometer 2)/ASI and AMSR2/DT-ASI.Compared with the annual average SIC of FY-3 B/NT2,our result is reduced by 2.31%.The annual average SIE difference between the two FY-3 Bs is 1.65×10^(6) km^(2),of which the DT-ASI algorithm contributes 87.9%and the land spillover method contributes12.1%.We further select 58 MODIS(Moderate-resolution Imaging Spectroradiometer)cloud-free samples in the Arctic region and use the tie-point method to retrieve SIC to verify the accuracy of these SIC products.The root mean square difference(RMSD)and mean absolute difference(MAD)of the FY-3 B/DT-ASI and MODIS results are 17.2%and 12.7%,which is close to those of two AMSR2 products with 6.25 km resolution and decreased 8%and 7.2%compared with FY-3 B/NT2.Further,FY-3 B/DT-ASI has the most significant improvement where the SIC is lower than 60%.A high-quality SIC product can be obtained by using the DT-ASI algorithm and our work will be beneficial to promote the application of Feng Yun Satellite.展开更多
BACKGROUND In mirror-image dextrocardia,the anterior-posterior position of the cardiac chambers and great vessels is maintained,but the left-right orientation of the abdominal organs is reversed.The abnormal anatomy o...BACKGROUND In mirror-image dextrocardia,the anterior-posterior position of the cardiac chambers and great vessels is maintained,but the left-right orientation of the abdominal organs is reversed.The abnormal anatomy of the heart poses surgical challenges and problems in dealing with surgical risk and monitoring complications.There are few reports on closure of the left atrial appendage(LAA)in dextrocardia and no reports on the application of enhanced recovery after surgery(ERAS)following LAA occlusion(LAAO)procedures.CASE SUMMARY The objective for this case was to ensure perioperative safety and accelerate postoperative recovery from LAAO in a patient with mirror-image dextrocardia.ERAS was guided by the theory and practice of nursing care.Atrial fibrillation was diagnosed in a 77-year-old male patient,in whom LAAO was performed.The 2019 guidelines for perioperative care after cardiac surgery recommend that the clinical nursing procedures for patients with LAAO should be optimized to reduce the incidence of perioperative complications and ensure patient safety.Music therapy can be used throughout perioperative treatment and nursing to improve the anxiety symptoms of patients.CONCLUSION The procedure was uneventful and proceeded without complications.Anxiety symptoms were improved.展开更多
In this article, we study the axisymmetric torsional contact problem of a half-space coated with functionally graded piezoelectric material (FGPM) and subjected to a rigid circular punch. It is found that, along the t...In this article, we study the axisymmetric torsional contact problem of a half-space coated with functionally graded piezoelectric material (FGPM) and subjected to a rigid circular punch. It is found that, along the thickness direction, the electromechanical properties of FGPMs change exponentially. We apply the Hankel integral transform technique and reduce the problem to a singular integral equation, and then numerically determine the unknown contact stress and electric displacement at the contact surface. The results show that the surface contact stress, surface azimuthal displacement, surface electric displacement, and inner electromechanical field are obviously dependent on the gradient index of the FGPM coating. It is found that we can adjust the gradient index of the FGPM coating to modify the distributions of the electric displacement and contact stress.展开更多
Long term in situ atmospheric observation of the landfast ice nearby Zhongshan Station in the Prydz Bay was performed from April to November 2016. The in situ observation, including the conventional meteorological ele...Long term in situ atmospheric observation of the landfast ice nearby Zhongshan Station in the Prydz Bay was performed from April to November 2016. The in situ observation, including the conventional meteorological elements and turbulent flux, enabled this study to evaluate the sea ice surface energy budget process. Using in situ observations, three different reanalysis datasets from the European Centre for Medium-Range Weather Forecasts Interim Re-analysis(ERA-Interim), National Centers for Environmental Prediction Reanalysis2(NCEP R2), and Japanese 55-year Reanalysis(JRA55), and the Los Alamos sea ice model, CICE, output for surface fluxes were evaluated. The observed sensible heat flux(SH) and net longwave radiation showed seasonal variation with increasing temperature. Air temperature rose from the middle of October as the solar elevation angle increased.The ice surface lost more energy by outgoing longwave radiation as temperature increased, while the shortwave radiation showed obvious increases from the middle of October. The oceanic heat flux demonstrated seasonal variation and decreased with time, where the average values were 21 W/m^(2) and 11 W/m^(2), before and after August,respectively. The comparisons with in situ observations show that, SH and LE(latent heat flux) of JRA55 dataset had the smallest bias and mean absolute error(MAE), and those of NCEP R2 data show the largest differences.The ERA-Interim dataset had the highest spatial resolution, but performance was modest with bias and MAE between JRA55 and NCEP R2 compare with in situ observation. The CICE results(SH and LE) were consistent with the observed data but did not demonstrate the amplitude of inner seasonal variation. The comparison revealed better shortwave and longwave radiation stimulation based on the ERA-Interim forcing in CICE than the radiation of ERA-Interim. The average sea ice temperature decreased in June and July and increased after September,which was similar to the temperature measured by buoys, with a bias and MAE of 0.9℃ and 1.0℃, respectively.展开更多
Hebei is one of the most air polluted provinces in China. According to the Ministry of Environmental Protection (MEP) for the severe fog-haze month of Jan. 2013, seven of the top ten most polluted cities in China are ...Hebei is one of the most air polluted provinces in China. According to the Ministry of Environmental Protection (MEP) for the severe fog-haze month of Jan. 2013, seven of the top ten most polluted cities in China are located in Hebei Province. In this study, the air pollution history and status of the Hebei Province are reviewed and discussed, using the governmental published Air Pollution Index (API), the academic observations by various scientific research groups and the long-term statistics of visibility and haze frequencies. It is found that within the Hebei Province, the air pollution in the southern cities is much more severe than the northern cities. Particulate matter (PM) is undoubtedly the major air pollutant, sulfur dioxide (SO2) and nitrogen oxides (NOX) pollutions are also unnegligible. Ozone (O3) pollution in larger cities, such as Shijiazhuang, is significant. Air pollution control history from 1998 is discussed as well. Although Hebei Province has made a great effort on air quality, the pollutant emissions, such as SO2 and fly ash, showed a notable increase in 2001 to 2006. However, after 2006 the emissions started to decrease due to the strict implementation of the national 11th Five Year Plan (FYP). In addition, regional jointly air pollution control and prevention strategies are expected in the future to substantially change the severe air pollution status in Hebei Province.展开更多
Up to now, perovskite solar cells(PSCs) have reached a certified 25.5% efficiency. As a promising photo-electric material, the metal halide perovskite possesses many outstanding properties such as tunable bandgap, lon...Up to now, perovskite solar cells(PSCs) have reached a certified 25.5% efficiency. As a promising photo-electric material, the metal halide perovskite possesses many outstanding properties such as tunable bandgap, long diffusion length, high absorption coefficient and carrier mobility. In spite of these remarkable properties, defects are inevitable during the solution processing. Therefore, many efforts have been made to reduce defects in perovskite films and thus improve the performance of devices. Among them,substitution or doping engineering is one of the most studied methods. Meanwhile, due to the poor stability of the organic-inorganic hybrid perovskite and the toxicity of Pb-based perovskite materials, all inorganic perovskite and lead-less or lead-free perovskite have emerged as promising materials. Here,we focus on the defect engineering especially substitutions on different sites in an ABX_(3) structure. The particular attention is devoted towards lead-less or lead-free perovskites, and we discuss several common elements or groups used to partially replace Pb^(2+). It is noted that proper elemental doping at different sites is an important guarantee for obtaining high-performance lead-less or lead-free PSCs.展开更多
Due to excellent thermal stability and optoelectronic properties, all-inorganic perovskite is one of the promising candidates to solve the thermal decomposition problem of conventional organic–inorganic hybrid perovs...Due to excellent thermal stability and optoelectronic properties, all-inorganic perovskite is one of the promising candidates to solve the thermal decomposition problem of conventional organic–inorganic hybrid perovskite solar cells(PSCs),but the larger voltage loss(V_(loss)) cannot be ignored, especially CsPbIBr_(2), which limits the improvement of efficiency. To reduce V_(loss), one promising solution is the modification of the energy level alignment between the perovskite layer and adjacent charge transport layer(CTL), which can facilitate charge extraction and reduce carrier recombination rate at the perovskite/CTL interface. Therefore, the key issues of minimum V_(loss) and high efficiency of CsPbIBr_(2)-based PSCs were studied in terms of the perovskite layer thickness, the effects of band offset of the CTL/perovskite layer, the doping concentration of the CTL, and the electrode work function in this study based on device simulations. The open-circuit voltage(V_(oc)) is increased from 1.37 V to 1.52 V by replacing SnO_(2) with ZnO as the electron transport layer(ETL) due to more matching conduction band with the CsPbIBr;layer.展开更多
Based on the couple-stress theory,the elastohydrodynamic lubrication(EHL)contact is analyzed with a consideration of the size effect.The lubricant between the contact surface of a homogeneous coated half-plane and a r...Based on the couple-stress theory,the elastohydrodynamic lubrication(EHL)contact is analyzed with a consideration of the size effect.The lubricant between the contact surface of a homogeneous coated half-plane and a rigid punch is supposed to be the non-Newtonian fluid.The density and viscosity of the lubricant are dependent on fluid pressure.Distributions of film thickness,in-plane stress,and fluid pressure are calculated by solving the nonlinear fluid-solid coupled equations with an iterative method.The effects of the punch radius,size parameter,coating thickness,slide/roll ratio,entraining velocity,resultant normal load,and stiffness ratio on lubricant film thickness,in-plane stress,and fluid pressure are investigated.The results demonstrate that fluid pressure and film thickness are obviously dependent on the size parameter,stiffness ratio,and coating thickness.展开更多
This paper studies the contact vibration problem of an elastic half-space coated with functionally graded materials(FGMs)subject to a rigid spherical punch.A static force superimposing a dynamic time-harmonic force ac...This paper studies the contact vibration problem of an elastic half-space coated with functionally graded materials(FGMs)subject to a rigid spherical punch.A static force superimposing a dynamic time-harmonic force acts on the rigid spherical punch.Firstly,we give the static contact problem of FGMs by a least-square fitting approach.Next,the dynamic contact pressure is solved by employing the perturbation method.Lastly,the dynamic contact stiffness with different dynamic contact displacement conditions is derived for the FGM coated half-space.The effects of the gradient index,coating thickness,internal friction,and punch radius on the dynamic contact stiffness factor are discussed in detail.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.U2141205,52371002,and 52374366)the Fundamental Research Funds for the Central Universities(Nos.06109125 and 06930007)Fundamental Research Funds for the Central Universities(No.FRF-BD-23-02).
文摘Laser powder bed fusion(LPBF)is a widely recognized additive manufacturing technology that can fabricate complex components rapidly through layer-by-layer formation.However,there is a paucity of research on the effect of laser scanning speed on the cellular microstructure and mechanical properties of martensitic stainless steel.This study systematically investigated the influence of laser scanning speed on the cellular microstructure and mechanical properties of a developed Fe11Cr8Ni5Co3Mo martensitic stainless steel produced by LPBF.The results show that increasing the laser scanning speed from 400 to 1000 mm/s does not lead to a noticeable change in the phase fraction,but it reduces the average size of the cellular microstructure from 0.60 to 0.35μm.The scanning speeds of 400 and 1000 mm/s both had adverse effects on performances of sample,resulting in inadequate fusion and keyhole defects respectively.The optimal scanning speed for fabricating samples was determined to be 800 mm/s,which obtained the highest room temperature tensile strength and elongation,with the ultimate tensile strength measured at(1088.3±2.0)MPa and the elongation of(16.76±0.10)%.Furthermore,the mechanism of the evolution of surface morphology,defects,and energy input were clarified,and the relationship between cellular microstructure size and mechanical properties was also established.
文摘BACKGROUND Pulmonary tuberculosis(PTB)is prevalent in immunocompromised populations,including patients with hematologic malignancies,human immunodeficiency virus infections,and chronic diseases.Effective treatment for acute promyelocytic leukemia(APL)combined with PTB is lacking.These patients show an extremely poor prognosis.Therefore,studies should establish efficient treatment options to improve patient survival and prognosis.CASE SUMMARY A 60-year-old male with pain in the right side of his chest and a fever for 4 d visited the outpatient department of our hospital.Peripheral blood smear revealed 54%blasts.Following bone marrow examinations,variant APL with TNRC18-RARA fusion gene was diagnosed.Chest computed tomography scan showed bilateral pneumonitis with bilateral pleural effusions,partial atelectasis in the lower lobes of both lungs,and the bronchoalveolar lavage fluid gene X-Pert test was positive,indicative of PTB.Carrimycin,ethambutol(EMB),and isoniazid(INH)were administered since he could not receive chemotherapy as the WBC count decreased continuously.After one week of treatment with carrimycin,the patient recovered from fever and received chemotherapy.Chemotherapy was very effective and his white blood cells counts got back to normal.After being given five months with rifampin,EMB and INH and chemotherapy,the patient showed complete remission from pneumonia and APL.CONCLUSION We report a case of PTB treated successfully with carrimycin with APL that requires chemotherapy.
基金supported by the National Natural Science Foundation of China(11062005 and 11202092)Open Fund of State Key Laboratory of Nonlinear Mechanics,the Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(NJYT-13-A02)+4 种基金the Natural Science Foundation of Inner Mongolia(2010BS0107 and 2012MS0107)the Research Start Up Fund for Excellent Talents at Inner Mongolia University(Z20080211)the support of Natural Science Key Fund of Inner Mongolia(2009ZD01)the Postgraduate Scientific Research Innovation Project of Inner Mongoliathe Enhancing Comprehensive Strength Project of Inner Mongolia University(14020202)
文摘By method of the Laplace transform, this arti- cle presents semi-analytical solutions for transient electro- osmotic and pressure-driven flows （EOF/PDF） of two-layer fluids between microparallel plates. The linearized Poisson- Boltzmann equation and the Cauchy momentum equation have been solved in this article. At the interface, the Maxwell stress is included as the boundary condition. By numerical computations of the inverse Laplace transform, the effects of dielectric constant ratio e, density ratio p, pressure ratio p, viscosity ratioμ of layer II to layer I, interface zeta potential difference △ψ, interface charge density jump Q, the ratios of maximum electro-osmotic velocity to pressure velocity , and the normalized pressure gradient B on transient veloc- ity amplitude are presented.We find the velocity amplitude becomes large with the interface zeta potential difference and becomes small with the increase of the viscosity. The ve- locity will be large with the increases of dielectric constant ratio; the density ratio almost does not influence the EOF ve- locity. Larger interface charge density jump leads to a strong jump of velocity at the interface. Additionally, the effects of the thickness of fluid layers （hi and h2） and pressure gradient on the velocity are also investigated.
文摘Flow behavior of transient mixed electro-osmotic and pressure driven flows (EOF/PDF) through a microannulus is investigated based on a linearized Poisson-Boltzmann equation and Navier-Stokes equation. A semi-analytical solution of EOF velocity distribution as functions of relevant parameters is derived by Laplace transform method. By numerical computations of inverse Laplace transform, the effects of inner to outer wall zeta potential β, the normalized pressure gradient Ω and the inner to outer radius ratio α on transient EOF velocity are presented.
文摘With urbanization and the rapid development of social economy,China’s rail transit industry has developed rapidly in recent years.In order to alleviate the pressure of road network,subways provide convenience as they are fast and space-saving.Subway stations are major energy consumers of urban power grid due to their large traffic volume and long operation time.On the premise of ensuring operation safety,reducing the energy consumption of subway helps in energy conservation and emission reduction as proposed in the 13th Five-Year Plan.According to the statistics of the energy-saving evaluation report of rail transit engineering,the lighting system accounts for 20%-30%of the total power consumption of the subway station.Due to the single lighting control mode of the lighting system in the subway station,the actual station illumination cannot be reported and adjusted in time,resulting in the waste of lighting energy and high power consumption of the system.Through in-depth research on the intelligent lighting system of subway station,this paper improves the system control,and finally summarizes the optimization scheme of subway station lighting design which can effectively save the power consumption of lighting system.The main contents of this paper are as follows:The research results of this paper can provide effective measures for energy saving of electric lighting in subway stations and reduce electric energy consumption;on the other hand,as an integral part of building lighting energy-saving system,it also has certain guiding significance for the research of building lighting energy-saving.
基金the funding support from the National Key Research and Development Program of China(2020YFB2007400)the National Natural Science Foundation of China(22209202,22075317)the Strategic Priority Research Program(B)(XDB33030200)of Chinese Academy of Sciences。
文摘Hetero-element doping is a promising strategy to improve the cycling stability of nickel-rich cobalt-free cathodes for the next-generation high energy-density Li ion batteries.To make doping effective,it is important to understand the mechanism of how the dopants regulate the electronic band,lattice parameter adjusting,or hetero-phase formation to achieve high stability.In this study,we investigate LiNi_(0.9)Mn_(0.1)O_(2)cathodes doped with IVB grouping elements via multiple characterization techniques.By utilizing in situ XRD and TEM methods,we found that the stronger Ti-O bond effectively improves the cathode stability via a dual protection mechanism.Specifically,the bulk lattice of cathode is wellpreserved during cycling as a result of the suppressed H_(2)-H_(3)phase transition,while a in situ formed Ti-rich surface layer can prevent continuous surface degradation.As a result,the 5%Ti doped LiNi_(0.9)Mn_(0.1)O_(2)cathode exhibits a high capacity retention of 96%after 100 cycles.Whereas,despite IVB group elements Zr and Hf have stronger bonding energy with oxygen,their larger ionic radii actually impede their diffusion into the cathode,thereby they can not improve the cycling stability.Our findings uncover the functional origin of doped elements with their dynamic modification on cathode structure,providing mechanistic insights into the design of nickel-rich cobalt-free cathodes.
基金financially supported by the National Natural Science Foundation of China(Nos.61604119,61704131,and 61804111)Initiative Postdocs Supporting Program(No.BX20180234)+2 种基金China Postdoctoral Science Foundation(No.2018M643578)Young Elite Scientists Sponsorship Program by CAST(2016QNRC001)Fundamental Research Funds for the Central Universities.
文摘Interface engineering has been regarded as an effective and noninvasive means to optimize the performance of perovskite solar cells(PSCs).Here,doping engineering of a ZnO electron transport layer(ETL)and CsPbI3/ZnO interface engineering via introduction of an interfacial layer are employed to improve the performances of CsPbI3-based PSCs.The results show that when introducing a TiO2 buffer layer while increasing the ZnO layer doping concentration,the open-circuit voltage,power conversion efficiency,and fill factor of the CsPbI3-based PSCs can be improved to 1.31 V,21.06%,and 74.07%,respectively,which are superior to those of PSCs only modified by the TiO2 buffer layer or high-concentration doping of ZnO layer.On the one hand,the buffer layer relieves the band bending and structural disorder of CsPbI3.On the other hand,the increased doping concentration of the ZnO layer improves the conductivity of the TiO2/ZnO bilayer ETL because of the strong interaction between the TiO2 and ZnO layers.However,such phenomena are not observed for those of a PCBM/ZnO bilayer ETL because of the weak interlayer interaction of the PCBM/ZnO interface.These results provide a comprehensive understanding of the CsPbI3/ZnO interface and suggest a guideline to design high-performance PSCs.
基金The National Key Basic Research Special Foundation of China under contract No.2017YFC1404500the National Natural Science Foundation of China under contract No.41676115
文摘This study investigated differences in the community structure and environmental responses of the bacterial community in sediments of the Bohai Sea.Illumina high-throughput sequencing technology and real-time PCR were used to assay the bacterial 16S rRNA genes in the surface sediments of 13 sampling stations in the Bohai Sea.The results showed that sediments at the majority of the 13 sampling stations were contaminated by heavy metal mercury.The main phyla of bacteria recorded included Proteobacteria(52.92%),Bacteroidetes(11.76%),Planctomycetes(7.39%),Acidobacteria(6.53%)and Chloroflexi(4.97%).The genus with the highest relative abundance was Desulfobulbus(4.99%),which was the dominant genus at most sampling stations,followed by Lutimonas and Halioglobus.The main factors influencing bacterial community structure were total organic carbon,followed by depth and total phosphorus.The content of lead,cadmium,chromium,copper and zinc had a consistent effect on community structure.Arsenic showed a negative correlation with bacterial community structure in most samples,while the impact of mercury on community structure was not significant.The bacterial community in sediment samples from the Bohai Sea was rich in diversity and displayed an increase in diversity from high to low latitudes.The data indicated that the Bohai Sea had abundant microbial resources and was rich in bacteria with the potential to metabolize many types of pollutants.
基金supported by the Natural Science Foundation of Zhejiang province(Grant LQ19H280009)Special Projects of Zhejiang Academy of Medical Sciences(Grant CA1918D-04,CA1903Q-04)Medical Health Science and Technology Project of Zhejiang Provincial Health Commission(Grant 2020384536)。
文摘Objective:To evaluate the anti-inflammatory activity of Crotalaria ferruginea extract(CFE)and its mechanism.Methods:An intratracheal lipopolysaccharide(LPS)instillationinduced acute lung injury(ALI)model was used to study the antiinflammatory activity of CFE in vivo.The LPS-induced shock model was used to analyze the effect of CFE on survival.LPS-stimulated RAW264.7 cell model was used to investigate the anti-inflammatory activity of CFE in vitro and the effects on mitogen-activated protein kinase(MAPK)or nuclear factor-κB(NF-κB)signaling pathways.Results:CFE administration decreased the number of inflammatory cells,reduced the levels of tumor necrosis factor-α(TNF-α),monocyte chemotactic protein-1(MCP-1),interleukin-6(IL-6),and interferon-γ,and diminished protein content in the bronchoalveolar lavage fluid of mice.CFE also reduced lung wet-to-dry weight ratio,myeloperoxidase,and lung tissue pathological injury.CFE preadministration improved the survival rate of mice challenged with a lethal dose of LPS.CFE reduced LPS-activated RAW264.7 cells to produce nitric oxide,TNF-α,MCP-1,and IL-6.Furthermore,CFE inhibited nuclear translocation and phosphorylation of NF-κB P65,extracellular signal-regulated kinase,c-Jun N-terminal kinases,and P38 MAPKs.Conclusions:CFE exhibits potent anti-inflammatory activity in LPS-induced ALI mice,LPS-shock mice,and RAW264.7 cells,and its mechanism may be associated with the inhibition of NF-κB and MAPK signaling pathways.Crotalaria ferruginea may be a useful therapeutic drug for the treatment of ALI and other respiratory inflammations.
基金The National Key Research and Development Program of China under contract No.2016YFC1402704the National Natural Science Foundation of China under contract Nos 41941012 and 42076228the Guangdong Basic and Applied Basic Research Foundation under contract No.2019A1515110295。
文摘Sea ice concentration(SIC)is one of the most important indicators when monitoring climate changes in the polar region.With the development of the Chinese satellite technology,the Feng Yun(FY)series has been applied to retrieve the sea ice parameters in the polar region.In this paper,to improve the SIC retrieval accuracy from the passive microwave(PM)data of the Microwave Radiation Imager(MWRI)aboard on the Feng Yun-3 B(FY-3 B)Satellite,the dynamic tie-point(DT)Arctic Radiation and Turbulence Interaction Study(ARTIST)Sea Ice(ASI)(DT-ASI)SIC retrieval algorithm is applied and obtained Arctic SIC data for nearly 10 a(from November 18,2010 to August 19,2019).Also,by applying a land spillover correction scheme,the erroneous sea ice along coastlines in melt season is removed.The results of FY-3 B/DT-ASI are obviously improved compared to that of FY-3 B/NT2(NASA-Team2)in both SIC and sea ice extent(SIE),and are highly consistent with the results of similar products of AMSR2(Advanced Microwave Scanning Radiometer 2)/ASI and AMSR2/DT-ASI.Compared with the annual average SIC of FY-3 B/NT2,our result is reduced by 2.31%.The annual average SIE difference between the two FY-3 Bs is 1.65×10^(6) km^(2),of which the DT-ASI algorithm contributes 87.9%and the land spillover method contributes12.1%.We further select 58 MODIS(Moderate-resolution Imaging Spectroradiometer)cloud-free samples in the Arctic region and use the tie-point method to retrieve SIC to verify the accuracy of these SIC products.The root mean square difference(RMSD)and mean absolute difference(MAD)of the FY-3 B/DT-ASI and MODIS results are 17.2%and 12.7%,which is close to those of two AMSR2 products with 6.25 km resolution and decreased 8%and 7.2%compared with FY-3 B/NT2.Further,FY-3 B/DT-ASI has the most significant improvement where the SIC is lower than 60%.A high-quality SIC product can be obtained by using the DT-ASI algorithm and our work will be beneficial to promote the application of Feng Yun Satellite.
基金Supported by Pudong New Area Science and Technology Development Fund Livelihood Scientific Research Project:Medical and Health,No.PKJ2020-Y106Shanghai Pudong New District Medical Discipline Construction Project C Cardiovascular Internal Medicine Clinical Plateau Discipline,No.PWYgy2018-03+1 种基金Shanghai Key Medical Specialty Construction Project,No.ZK2019B25Scientific Research Project of Shanghai Municipal Health and Family Planning Commission(Youth Project),No.20184Y0230.
文摘BACKGROUND In mirror-image dextrocardia,the anterior-posterior position of the cardiac chambers and great vessels is maintained,but the left-right orientation of the abdominal organs is reversed.The abnormal anatomy of the heart poses surgical challenges and problems in dealing with surgical risk and monitoring complications.There are few reports on closure of the left atrial appendage(LAA)in dextrocardia and no reports on the application of enhanced recovery after surgery(ERAS)following LAA occlusion(LAAO)procedures.CASE SUMMARY The objective for this case was to ensure perioperative safety and accelerate postoperative recovery from LAAO in a patient with mirror-image dextrocardia.ERAS was guided by the theory and practice of nursing care.Atrial fibrillation was diagnosed in a 77-year-old male patient,in whom LAAO was performed.The 2019 guidelines for perioperative care after cardiac surgery recommend that the clinical nursing procedures for patients with LAAO should be optimized to reduce the incidence of perioperative complications and ensure patient safety.Music therapy can be used throughout perioperative treatment and nursing to improve the anxiety symptoms of patients.CONCLUSION The procedure was uneventful and proceeded without complications.Anxiety symptoms were improved.
基金supported by the National Natural Science Foundation of China (Grants 11272040, 11322218)the Fundamental Research Funds for the Central Universities (Grant 2016YJS113)
文摘In this article, we study the axisymmetric torsional contact problem of a half-space coated with functionally graded piezoelectric material (FGPM) and subjected to a rigid circular punch. It is found that, along the thickness direction, the electromechanical properties of FGPMs change exponentially. We apply the Hankel integral transform technique and reduce the problem to a singular integral equation, and then numerically determine the unknown contact stress and electric displacement at the contact surface. The results show that the surface contact stress, surface azimuthal displacement, surface electric displacement, and inner electromechanical field are obviously dependent on the gradient index of the FGPM coating. It is found that we can adjust the gradient index of the FGPM coating to modify the distributions of the electric displacement and contact stress.
基金The National Key R&D Program of China under contract No. 2018YFA0605903the National Natural Science Foundation of China under contract Nos 41941009, 41922044 and 41876212the Guangdong Basic and Applied Basic Research Foundation under contract No. 2020B1515020025。
文摘Long term in situ atmospheric observation of the landfast ice nearby Zhongshan Station in the Prydz Bay was performed from April to November 2016. The in situ observation, including the conventional meteorological elements and turbulent flux, enabled this study to evaluate the sea ice surface energy budget process. Using in situ observations, three different reanalysis datasets from the European Centre for Medium-Range Weather Forecasts Interim Re-analysis(ERA-Interim), National Centers for Environmental Prediction Reanalysis2(NCEP R2), and Japanese 55-year Reanalysis(JRA55), and the Los Alamos sea ice model, CICE, output for surface fluxes were evaluated. The observed sensible heat flux(SH) and net longwave radiation showed seasonal variation with increasing temperature. Air temperature rose from the middle of October as the solar elevation angle increased.The ice surface lost more energy by outgoing longwave radiation as temperature increased, while the shortwave radiation showed obvious increases from the middle of October. The oceanic heat flux demonstrated seasonal variation and decreased with time, where the average values were 21 W/m^(2) and 11 W/m^(2), before and after August,respectively. The comparisons with in situ observations show that, SH and LE(latent heat flux) of JRA55 dataset had the smallest bias and mean absolute error(MAE), and those of NCEP R2 data show the largest differences.The ERA-Interim dataset had the highest spatial resolution, but performance was modest with bias and MAE between JRA55 and NCEP R2 compare with in situ observation. The CICE results(SH and LE) were consistent with the observed data but did not demonstrate the amplitude of inner seasonal variation. The comparison revealed better shortwave and longwave radiation stimulation based on the ERA-Interim forcing in CICE than the radiation of ERA-Interim. The average sea ice temperature decreased in June and July and increased after September,which was similar to the temperature measured by buoys, with a bias and MAE of 0.9℃ and 1.0℃, respectively.
文摘Hebei is one of the most air polluted provinces in China. According to the Ministry of Environmental Protection (MEP) for the severe fog-haze month of Jan. 2013, seven of the top ten most polluted cities in China are located in Hebei Province. In this study, the air pollution history and status of the Hebei Province are reviewed and discussed, using the governmental published Air Pollution Index (API), the academic observations by various scientific research groups and the long-term statistics of visibility and haze frequencies. It is found that within the Hebei Province, the air pollution in the southern cities is much more severe than the northern cities. Particulate matter (PM) is undoubtedly the major air pollutant, sulfur dioxide (SO2) and nitrogen oxides (NOX) pollutions are also unnegligible. Ozone (O3) pollution in larger cities, such as Shijiazhuang, is significant. Air pollution control history from 1998 is discussed as well. Although Hebei Province has made a great effort on air quality, the pollutant emissions, such as SO2 and fly ash, showed a notable increase in 2001 to 2006. However, after 2006 the emissions started to decrease due to the strict implementation of the national 11th Five Year Plan (FYP). In addition, regional jointly air pollution control and prevention strategies are expected in the future to substantially change the severe air pollution status in Hebei Province.
基金financially supported by the National Key Research and Development Program of China (Grant No.2018YFB2202900)the National Natural Science Foundation of China (Grant Nos. 52192610, 61704131)+3 种基金the Key Research and Development Program of Shaanxi Province (Grant No. 2020GY-310)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University (Grant No. 2020GXLH-Z-018)the Fundamental Research Funds for the Central Universitiesthe Innovation Fund of Xidian University。
文摘Up to now, perovskite solar cells(PSCs) have reached a certified 25.5% efficiency. As a promising photo-electric material, the metal halide perovskite possesses many outstanding properties such as tunable bandgap, long diffusion length, high absorption coefficient and carrier mobility. In spite of these remarkable properties, defects are inevitable during the solution processing. Therefore, many efforts have been made to reduce defects in perovskite films and thus improve the performance of devices. Among them,substitution or doping engineering is one of the most studied methods. Meanwhile, due to the poor stability of the organic-inorganic hybrid perovskite and the toxicity of Pb-based perovskite materials, all inorganic perovskite and lead-less or lead-free perovskite have emerged as promising materials. Here,we focus on the defect engineering especially substitutions on different sites in an ABX_(3) structure. The particular attention is devoted towards lead-less or lead-free perovskites, and we discuss several common elements or groups used to partially replace Pb^(2+). It is noted that proper elemental doping at different sites is an important guarantee for obtaining high-performance lead-less or lead-free PSCs.
基金financially supported by the National Natural Science Foundation of China (Grant No. 52192610)the Key Research and Development Program of Shaanxi Province, China (Grant No. 2020GY-310)+2 种基金Youth Project of Natural Science Basic Research Program of Shaanxi Province, China (Grant No. 2021JQ-189)the Joint Research Funds of Department of Science & Technology of Shaanxi Province and Northwestern Polytechnical University (Grant No. 2020GXLH-Z-018)the Fundamental Research Funds for the Central Universities, China。
文摘Due to excellent thermal stability and optoelectronic properties, all-inorganic perovskite is one of the promising candidates to solve the thermal decomposition problem of conventional organic–inorganic hybrid perovskite solar cells(PSCs),but the larger voltage loss(V_(loss)) cannot be ignored, especially CsPbIBr_(2), which limits the improvement of efficiency. To reduce V_(loss), one promising solution is the modification of the energy level alignment between the perovskite layer and adjacent charge transport layer(CTL), which can facilitate charge extraction and reduce carrier recombination rate at the perovskite/CTL interface. Therefore, the key issues of minimum V_(loss) and high efficiency of CsPbIBr_(2)-based PSCs were studied in terms of the perovskite layer thickness, the effects of band offset of the CTL/perovskite layer, the doping concentration of the CTL, and the electrode work function in this study based on device simulations. The open-circuit voltage(V_(oc)) is increased from 1.37 V to 1.52 V by replacing SnO_(2) with ZnO as the electron transport layer(ETL) due to more matching conduction band with the CsPbIBr;layer.
基金Project supported by the National Natural Science Foundation of China(Nos.11902217,11725207,12011530056)the Russian Foundation for Basic Research(No.20-58-53045-GFEN-a)。
文摘Based on the couple-stress theory,the elastohydrodynamic lubrication(EHL)contact is analyzed with a consideration of the size effect.The lubricant between the contact surface of a homogeneous coated half-plane and a rigid punch is supposed to be the non-Newtonian fluid.The density and viscosity of the lubricant are dependent on fluid pressure.Distributions of film thickness,in-plane stress,and fluid pressure are calculated by solving the nonlinear fluid-solid coupled equations with an iterative method.The effects of the punch radius,size parameter,coating thickness,slide/roll ratio,entraining velocity,resultant normal load,and stiffness ratio on lubricant film thickness,in-plane stress,and fluid pressure are investigated.The results demonstrate that fluid pressure and film thickness are obviously dependent on the size parameter,stiffness ratio,and coating thickness.
基金Project supported by the National Natural Science Foundation of China(Nos.11725207,12021002,and 12072226)。
文摘This paper studies the contact vibration problem of an elastic half-space coated with functionally graded materials(FGMs)subject to a rigid spherical punch.A static force superimposing a dynamic time-harmonic force acts on the rigid spherical punch.Firstly,we give the static contact problem of FGMs by a least-square fitting approach.Next,the dynamic contact pressure is solved by employing the perturbation method.Lastly,the dynamic contact stiffness with different dynamic contact displacement conditions is derived for the FGM coated half-space.The effects of the gradient index,coating thickness,internal friction,and punch radius on the dynamic contact stiffness factor are discussed in detail.
