The increasingly stringent performance requirement in integrated circuit manufacturing, characterized by smaller feature sizes and higher productivity, necessitates the wafer stage executing a extreme motion with the ...The increasingly stringent performance requirement in integrated circuit manufacturing, characterized by smaller feature sizes and higher productivity, necessitates the wafer stage executing a extreme motion with the accuracy in terms of nanometers. This demanding requirement witnesses a widespread application of iterative learning control(ILC), given the repetitive nature of wafer scanning. ILC enables substantial performance improvement by using past measurement data in combination with the system model knowledge. However, challenges arise in cases where the data is contaminated by the stochastic noise, or when the system model exhibits significant uncertainties, constraining the achievable performance. In response to this issue, an extended state observer(ESO) based adaptive ILC approach is proposed in the frequency domain.Despite being model-based, it utilizes only a rough system model and then compensates for the resulting model uncertainties using an ESO, thereby achieving high robustness against uncertainties with minimal modeling effort. Additionally, an adaptive learning law is developed to mitigate the limited performance in the presence of stochastic noise, yielding high convergence accuracy yet without compromising convergence speed. Simulation and experimental comparisons with existing model-based and data-driven inversion-based ILC validate the effectiveness as well as the superiority of the proposed method.展开更多
Dear Editor,Severe fever with thrombocytopenia syndrome(SFTS)is an emerging tick-borne infectious disease caused by a novel bunyavirus called SFTS virus(SFTSV).It was initially identified in China in 2009(Yu et al.,20...Dear Editor,Severe fever with thrombocytopenia syndrome(SFTS)is an emerging tick-borne infectious disease caused by a novel bunyavirus called SFTS virus(SFTSV).It was initially identified in China in 2009(Yu et al.,2011).Since then,the number of reported SFTS cases has rapidly increased in China,South Korea,and Japan(Li,et al.,2018;Takahashi et al.,2014;Kim et al.,2018).Sporadic SFTS cases have also been identified in several other Asian countries,such as Vietnam,Pakistan,Myanmar,and Thailand(Takahashi et al.,2014;Tran et al.,2019;Li et al.,2021).This disease is recognized as a highly lethal viral hemorrhagic fever with a mortality rate ranging from 12%to 50%(Yu et al.,2011;Li et al.,2018;Takahashi et al.,2014;Kim et al.,2013).SFTS primarily spreads to humans through bites from ticks infected with SFTSV,with the Haemaphysalis longicornis tick acting as the predominant vector for SFTSV(Zhuang et al.,2018).展开更多
This study investigated the formation mechanism of new grains due to twin–twin intersections in a coarse-grained Mg–6Al–3Sn–2Zn alloy during different strain rates of an isothermal compression.The results of elect...This study investigated the formation mechanism of new grains due to twin–twin intersections in a coarse-grained Mg–6Al–3Sn–2Zn alloy during different strain rates of an isothermal compression.The results of electron backscattered diffraction investigations showed that the activated twins were primarily{1012}tension twins,and 60°<1010>boundaries formed due to twin–twin intersections under different strain rates.Isolated twin variants with 60°<1010>boundaries transformed into new grains through lattice rotations at a low strain rate(0.01 s^(−1)).At a high strain rate(10 s^(−1)),the regions surrounded by subgrain boundaries through high-density dislocation arrangement and the 60°<1010>boundaries transformed into new grains via dynamic recrystallization.展开更多
This study systematically compared the influences of yttrium（Y）,boron（B）,and carbon（C） on the microstructural refinement and properties of a Ti-43Al-5Nb alloy.The microstructural refinement effect in the TiAl al...This study systematically compared the influences of yttrium（Y）,boron（B）,and carbon（C） on the microstructural refinement and properties of a Ti-43Al-5Nb alloy.The microstructural refinement effect in the TiAl alloy closely depends on the refiner used.The refinement effects of the three elements on colony size and lamellar thickness can be arranged as B 〉 Y 〉 C and Y 〉 C 〉 B,respectively.Moreover,a microstructure with a small grain size and ultra-fine lamellar spacing can be obtained by adding B and Y or B and C.The mechanical properties of TiAl alloy are also influenced by the refiners.TiAl alloys with proper B and Y contents exhibit favorable hot workability,tensile properties,and fracture toughness,whereas the C-containing alloy displays poor tensile properties and low fracture toughness.These results indicate that Y and B are more suitable microstructure refiners than C.This study may serve as a reference for practical alloying design.展开更多
Heavy metal(Cu,Mn,Zn,Pb,and Cd)concentrations were measured in the leaves of Sabina chinensis and Platycladus orientalis collected from urban,suburban,and rural sites in Tianjin,China.Photosynthetic pigment contents,r...Heavy metal(Cu,Mn,Zn,Pb,and Cd)concentrations were measured in the leaves of Sabina chinensis and Platycladus orientalis collected from urban,suburban,and rural sites in Tianjin,China.Photosynthetic pigment contents,reactive oxygen species content,malondialdehyde(MDA)content and antioxidant enzyme activity were investigated,providing physiological response parameters.Our comparison of the sites revealed that urbanization significantly influenced the heavy metal concentrations in both plant leaves.At the rural site,both plant leaves exhibited the lowest heavy metal accumulation.The highest Cu,Mn,and Zn concentrations were found in S.chinensis leaves from the urban site;the highest Pb and Cd concentrations were found in P.orientalis leaves from the urban site.These results indicate that the urban site contained larger heavy metal concentrations in the plant leaves that may reflect the anthropogenic emission gradient.It is also found that S.chinensis may be used to monitor airborne heavy metal pollution because it is highly quick response to heavy metals,while P.orientalis may be used for mitigation due to its high resistance.The results of this study can contribute to the development of monitoring and environmental management plans by providing information on sensitive and resistant tree species for city greening in North China.展开更多
3D human pose estimation is a major focus area in the field of computer vision,which plays an important role in practical applications.This article summarizes the framework and research progress related to the estimat...3D human pose estimation is a major focus area in the field of computer vision,which plays an important role in practical applications.This article summarizes the framework and research progress related to the estimation of monocular RGB images and videos.An overall perspective ofmethods integrated with deep learning is introduced.Novel image-based and video-based inputs are proposed as the analysis framework.From this viewpoint,common problems are discussed.The diversity of human postures usually leads to problems such as occlusion and ambiguity,and the lack of training datasets often results in poor generalization ability of the model.Regression methods are crucial for solving such problems.Considering image-based input,the multi-view method is commonly used to solve occlusion problems.Here,the multi-view method is analyzed comprehensively.By referring to video-based input,the human prior knowledge of restricted motion is used to predict human postures.In addition,structural constraints are widely used as prior knowledge.Furthermore,weakly supervised learningmethods are studied and discussed for these two types of inputs to improve the model generalization ability.The problem of insufficient training datasets must also be considered,especially because 3D datasets are usually biased and limited.Finally,emerging and popular datasets and evaluation indicators are discussed.The characteristics of the datasets and the relationships of the indicators are explained and highlighted.Thus,this article can be useful and instructive for researchers who are lacking in experience and find this field confusing.In addition,by providing an overview of 3D human pose estimation,this article sorts and refines recent studies on 3D human pose estimation.It describes kernel problems and common useful methods,and discusses the scope for further research.展开更多
The quasi-metallic fibers were selected from 1 to 40 pieces and connected in parallel in this study.The giant magneto impedance(GMI)effect of Co-based melt extract fibers in the bundle mode was investigated,and the di...The quasi-metallic fibers were selected from 1 to 40 pieces and connected in parallel in this study.The giant magneto impedance(GMI)effect of Co-based melt extract fibers in the bundle mode was investigated,and the distribution of the surface circumferential magnetic field on the fibers was also analyzed.Such distribution was induced by the driving current,which gave rise to the circular magnetization process and the GMI effect.The improved GMI effect with much higher field sensitivity was observed in these fiber bundles.Results show that the field sensitivities of the four-fiber and six-fiber bundles reach 19.5 V·m·kA−1(at 1 MHz)and 30.8 V·m·kA−1(at 5 MHz).The circumferential magnetic field distributed throughout the fiber’s circumferential surface is rearranged and becomes uneven due to the magnetic interaction among fibers.There are both strengthened and weakened magnetic field parts around these fibers’surfaces.The strengthened magnetic field improves the circumferential domain magnetization of the surface,resulting in larger GMI effects.However,the weakened parts inhibit the circumferential magnetization process and,therefore,the GMI effect.This also induces greater magnetization damp because of the increased domain interactions under the strong skin effect.The co-effect between the magnetic domains and the circumferential magnetization induces the optimization of the GMI effect in the four-fiber bundles.The observed GMI effect proves that fibers in bundle form can modify the sensitivity of the GMI effect.Moreover,different fiber bundles could be tuned according to the working conditions in order to manipulate the GMI response.展开更多
Mineral potential assessment at the Earth’s surface has been an important research for geoscientists around the world in the past five decades. The fundamental aspects of mineral assessment at different scales can be...Mineral potential assessment at the Earth’s surface has been an important research for geoscientists around the world in the past five decades. The fundamental aspects of mineral assessment at different scales can be associated with the following tasks, e.g., mineral potential mapping and estimation of mineral resources. This paper summarized the history and development in terms of theories, methods technologies and software platforms for quantitative assessment of mineral resources in China, e.g. comprehensive information methodology, geological anomaly, three-component quantitative prediction method, 5P orefinding area, integrated information assessment method, nonlinear process modeling and fractals, three dimensional mineral potential mapping, etc. At last, to discuss the future of quantitative mineral assessment in an era of big data including platform for 3D visualization, analysis and sharing, new methods and protocols for data cleaning, information enhancement, information integration, and uncertainties and multiple explanations of multi-information.展开更多
The microstructure and cellular transition characteristics of an intermetallic Ti-42Al-3Nb-1Mo-0.1B (at.%) alloy were investigated.The as-cast microstructure of the alloy is mainly composed of (α2+γ) lamellar struct...The microstructure and cellular transition characteristics of an intermetallic Ti-42Al-3Nb-1Mo-0.1B (at.%) alloy were investigated.The as-cast microstructure of the alloy is mainly composed of (α2+γ) lamellar structure and (β+γ) mixture structure,which distributes along the boundaries of the lamellar colonies.In order to study the phase transformation of lamellar structure at aging temperature,a two-step heat treatment was carried out.After the first step of annealing treatment at 1,260 °C,the microstructure with relatively finer lamellar space and (γ+β/B2) mixture structure is obtained.Aging treatment,as the second heat treatment step,has significant influence on the microstructure,attributing to a cellular reaction of α2+γ→γ+β.With the increase of aging temperature,the (α2+γ) lamellar structure continues to dissolve,whereas the contents of both the equiaxed γ and β/B2 grains continuously increase.Besides,the orientation of lamellae α2,equiaxed γ and equiaxed β/B2 in the cellular transition region follows a specific relationship of {0-11}β<1-11>β//{0001}α2<2-1-10>α2//{1-11}γ<-101>γ.展开更多
In this study, the 3-dimensional discrete element method is firstly introduced to explain the fracturing damage process of the dynamic split experiment of a special brittle glass ZnS. The corresponding dynamic split e...In this study, the 3-dimensional discrete element method is firstly introduced to explain the fracturing damage process of the dynamic split experiment of a special brittle glass ZnS. The corresponding dynamic split experiment is also performed by using the split Hopkinson pressure bar. Then the numerical results correspond closely to those obtained by experiments, and the fracturing damage mode shows that the sample under high strain rate loading would crack along vertical diameter in the band region between two loading edges, which differs from the static damage mode. Furthermore, by comparing a group of contrast numerical tests, the numerical results prove that loading area upon the top side of samples would influence the fracture mode of dynamic split experiments, which indicates that the narrow loading plane is better.展开更多
To the Editor:Meat is an important source of protein and could be roughly classied into red and white meat.White meat,which encompasses poultry,seafood such assh and shrimp,and reptiles,etc.,is characterized by its pa...To the Editor:Meat is an important source of protein and could be roughly classied into red and white meat.White meat,which encompasses poultry,seafood such assh and shrimp,and reptiles,etc.,is characterized by its pale color when uncooked.Red meat is basically mammalian meat,including domestic animal meats,such as pork,beef,lamb,and wild animal meat in certain regions,such as kangaroos,seals,and whales.Uncooked mammalian meat appears red due to the presence of myoglobin in skeletal muscles.The clinical presentations of mammalian meat allergy comprise two types of allergic reactions,immediatetype and delayed-type,although both are mediated by immunoglobulin E(IgE).The immediate-type hypersensitivity manifests as allergic symptoms occurring shortly after ingestion of red meat and is primarily triggered by serum albumin and immunoglobulin which are the major allergenic components.This is the classic pattern of food allergy.The delayed-type hypersensitivity is characterized by delayed onset of allergic symptoms 2-6 h after red meat ingestion and is mediated by oligosaccharideα-gal-specic IgE which is a recently discoveried pattern of food allergy.展开更多
Background: Severe fever with thrombocytopenia (SFTS) caused by SFTS virus (SFTSV) was a tick-borne hemorrhagic fever that posed significant threat to human health in Eastern Asia. The study was designed to measure th...Background: Severe fever with thrombocytopenia (SFTS) caused by SFTS virus (SFTSV) was a tick-borne hemorrhagic fever that posed significant threat to human health in Eastern Asia. The study was designed to measure the seroprevalence of SFTSV antibody in healthy population residing in a high endemic region.Methods: A cohort study was performed on healthy residents in Shangcheng County in Xinyang City from April to December in 2018, where the highest SFTS incidence in China was reported. Anti-SFTSV IgG was measured by indirect enzyme-linked immunosorbent assay and neutralizing antibody (NAb) was detected by using PRNT50. The logistic regression models were performed to analyze the variables that were associated with seropositive rates.Results: Totally 886 individuals were recruited. The baseline seroprevalence that was tested before the epidemic season was 11.9% (70/587) for IgG and 6.8% (40/587) for NAb, which was increased to 13.4% (47/350) and 7.7% (27/350) during the epidemic season, and further to 15.8% (80/508) and 9.8% (50/508) post epidemic. The IgG antibody-based seropositivity was significantly related to the patients aged ≥ 70 years old [adjusted odds ratio (OR) = 2.440, 95% confidence interval (CI): 1.334-4.461 compared to the group of < 50 years old,P = 0.004], recent contact with cats (adjustedOR = 2.195, 95%CI: 1.261-3.818,P = 0.005), and working in tea garden (adjustedOR = 1.698, 95%CI: 1.002-2.880,P = 0.049) by applying multivariate logistic regression model. The NAb based seropositivity was similarly related to the patients aged ≥ 70 years old (adjustedOR = 2.691, 95%CI: 1.271-5.695 compared to the group of < 50 years old,P = 0.010), and recent contact with cats (OR = 2.648, 95%CI: 1.419-4.941,P = 0.002). For a cohort of individuals continually sampled with 1-year apart, the anti-SFTSV IgG were maintained at a stable level, while the NAb level reduced.Conclusions: Subclinical infection might not provide adequate immunity to protect reinfection of SFTSV, thus highlighting the ongoing threats of SFTS in endemic regions, which called for an imperative need for vaccine development. Identification of risk factors might help to target high-risk population for public health education and vaccination in the future.展开更多
Severe fever with thrombocytopenia syndrome(SFTS)virus(SFTSV)is an emerging tick-borne virus with high fatality and an expanding endemic.Currently,effective anti-SFTSV intervention remains unavailable.Favipiravir(T-70...Severe fever with thrombocytopenia syndrome(SFTS)virus(SFTSV)is an emerging tick-borne virus with high fatality and an expanding endemic.Currently,effective anti-SFTSV intervention remains unavailable.Favipiravir(T-705)was recently reported to show in vitro and in animal model antiviral efficacy against SFTSV.Here,we conducted a single-blind,randomized controlled trial to assess the efficacy and safety of T-705 in treating SFTS(Chinese Clinical Trial Registry website,number ChiCTR1900023350).From May to August 2018,laboratory-confirmed SFTS patients were recruited from a designated hospital and randomly assigned to receive oral T-705 in combination with supportive care or supportive care only.Fatal outcome occurred in 9.5%(7/74)of T-705 treated patients and 18.3%(13/71)of controls(odds ratio,0.466,95%Cl,0.174-1.247).Cox regression showed a significant reduction in case fatality rate(CFR)with an adjusted hazard ratio of 0.366(95%Cl,0.142-0.944).Among the low-viral load subgroup(RT-PCR cycle threshold>26),T-705 treatment significantly reduced CFR from 11.5 to 1.6%(P=0.029),while no between-arm difference was observed in the high-viral load subgroup(RT-PCR cycle threshold<26).The T-705-treated group showed shorter viral clearance,lower incidence of hemorrhagic signs,and faster recovery of laboratory abnormities compared with the controls.The in vitro and animal experiments demonstrated that the antiviral efficacies of T-705 were proportionally induced by SFTSV mutation rates,particularly from two transition mutation types.The mutation analyses on T-705-treated serum samples disclosed a partially consistent mutagenesis pattern as those of the in vitro or animal experiments in reducing the SFTSV viral loads,further supporting the anti-SFTSV effect of T-705,especially for the low-viral loads.展开更多
Low-carbon economy is gaining growing attention nowadays as global warming intensifies.As a market-based policy,emission trading policy is widely considered an effective means to achieve the doublewin of economic deve...Low-carbon economy is gaining growing attention nowadays as global warming intensifies.As a market-based policy,emission trading policy is widely considered an effective means to achieve the doublewin of economic development and environmental protection.Under such circumstances,carbon trading markets are developing rapidly in many countries and regions,demanding more attention to compliance strategy issues for emission-intensive companies.In this study,we build a dynamic programming model in search of the optimal emission trading and technology investment decisions for a make-to-order company faced with a stochastic demand under emission trading policy.After a comprehensive analysis of the proposed model,we find that an optimal emission permit level,which increases in carbon penalty and decreases in carbon price,exists in each period.As for the abatement technology investment decision,the firm should invest only ff the investment cost per unit of abatement effort is less than a certain threshold,which increases in carbon penalty and carbon price.On the basis of a two-period dynamic programming model,we further explore the problem of investment timing.Results show how optimal investment decisions are influenced by the speed of technology progress under different parameters.These findings are important for firms to choose the time of investment depending on specific situations.展开更多
Background:Severe fever with thrombocytopenia syndrome(SFTS),an emerging tickborne infectious disease caused by a novel banyangvirus(SFTS virus,SFTSV),was endemic in several Asian countries with a high mortality up to...Background:Severe fever with thrombocytopenia syndrome(SFTS),an emerging tickborne infectious disease caused by a novel banyangvirus(SFTS virus,SFTSV),was endemic in several Asian countries with a high mortality up to 30%.Until recently,SFTSV-associated re-infection have not been reported and investigated.展开更多
The purpose of this work was to investigate the differences in the anti-oxidative stress and anti-inflammatory effects between all-E(trans)-lutein and its 9Z(cis)-and 13Z-isomers using the human intestinal Caco-2 cell...The purpose of this work was to investigate the differences in the anti-oxidative stress and anti-inflammatory effects between all-E(trans)-lutein and its 9Z(cis)-and 13Z-isomers using the human intestinal Caco-2 cell model.I-TiO_(2) catalyst was used to isomerize all-E-lutein to obtain 9Z-lutein and 13Z-lutein.In anti-oxidative stress studies,all three lutein isoforms could significantly reduce H2O_(2)-induced interleukin-8(IL-8)and tumor necrosis factor-α(TNF-α)secretion(p<0.05)by 50%or more at 4μM.At lower concentration(2μM),9Z-lutein and 13Z-lutein showed higher protection against oxidative stress than all-E-lutein by significantly reducing IL-8 secretion by 48%and 40%(p<0.05),respectively.In addition,three lutein isomers,especially 9Z-lutein could up-regulate the activity of antioxidant enzymes including catalase(CAT),glutathione peroxidase(GPx),gluta-thione reductase(GR),and the content of endogenous antioxidant glutathione(GSH)at 2μM.In the anti-inflammatory assay,9Z-lutein and all-E-lutein exhibited higher anti-inflammatory effects than 13Z-lutein in reducing the secretion and expression of IL-8 in TNF-αinduced inflammatory Caco-2 cells.Compared with the positive control,9Z-lutein and all-E-lutein could reduce the expression of the IL-8 gene by 49%and 52%,respectively at 4μM.This study provided a theoretical basis for the potential health benefits of Z-luteins.展开更多
基金supported by National Natural Science Foundation of China(52375530,52075132)Natural Science Foundation of Heilongjiang Province(YQ2022E025)+4 种基金State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment(Guangdong University of Technology)(JMDZ202312)Fundamental Research Funds for the Central Universities(HIT.OCEF.2024034)China Postdoctoral Science Foundation(2019M651278,2020T130155)Heilongjiang Province Postdoctoral Science Foundation(LBH-Z19066)Space Drive and Manipulation Mechanism Laboratory of BICE and National Key Laboratory of Space Intelligent Control,No BICE-SDMM-2024-01
文摘The increasingly stringent performance requirement in integrated circuit manufacturing, characterized by smaller feature sizes and higher productivity, necessitates the wafer stage executing a extreme motion with the accuracy in terms of nanometers. This demanding requirement witnesses a widespread application of iterative learning control(ILC), given the repetitive nature of wafer scanning. ILC enables substantial performance improvement by using past measurement data in combination with the system model knowledge. However, challenges arise in cases where the data is contaminated by the stochastic noise, or when the system model exhibits significant uncertainties, constraining the achievable performance. In response to this issue, an extended state observer(ESO) based adaptive ILC approach is proposed in the frequency domain.Despite being model-based, it utilizes only a rough system model and then compensates for the resulting model uncertainties using an ESO, thereby achieving high robustness against uncertainties with minimal modeling effort. Additionally, an adaptive learning law is developed to mitigate the limited performance in the presence of stochastic noise, yielding high convergence accuracy yet without compromising convergence speed. Simulation and experimental comparisons with existing model-based and data-driven inversion-based ILC validate the effectiveness as well as the superiority of the proposed method.
基金funded by the National Nature Science Foundation of China(81,825,019 and 82,330,103)performed with approval from the Ethical Committee of Beijing Institute of Microbiology and Epidemiology(AF/SC-08/02.128).
文摘Dear Editor,Severe fever with thrombocytopenia syndrome(SFTS)is an emerging tick-borne infectious disease caused by a novel bunyavirus called SFTS virus(SFTSV).It was initially identified in China in 2009(Yu et al.,2011).Since then,the number of reported SFTS cases has rapidly increased in China,South Korea,and Japan(Li,et al.,2018;Takahashi et al.,2014;Kim et al.,2018).Sporadic SFTS cases have also been identified in several other Asian countries,such as Vietnam,Pakistan,Myanmar,and Thailand(Takahashi et al.,2014;Tran et al.,2019;Li et al.,2021).This disease is recognized as a highly lethal viral hemorrhagic fever with a mortality rate ranging from 12%to 50%(Yu et al.,2011;Li et al.,2018;Takahashi et al.,2014;Kim et al.,2013).SFTS primarily spreads to humans through bites from ticks infected with SFTSV,with the Haemaphysalis longicornis tick acting as the predominant vector for SFTSV(Zhuang et al.,2018).
基金support from the Key Technology Research and Development Program of Shandong Province(Project No.2019GGX102060).
文摘This study investigated the formation mechanism of new grains due to twin–twin intersections in a coarse-grained Mg–6Al–3Sn–2Zn alloy during different strain rates of an isothermal compression.The results of electron backscattered diffraction investigations showed that the activated twins were primarily{1012}tension twins,and 60°<1010>boundaries formed due to twin–twin intersections under different strain rates.Isolated twin variants with 60°<1010>boundaries transformed into new grains through lattice rotations at a low strain rate(0.01 s^(−1)).At a high strain rate(10 s^(−1)),the regions surrounded by subgrain boundaries through high-density dislocation arrangement and the 60°<1010>boundaries transformed into new grains via dynamic recrystallization.
基金financially supported by the National Nature Science Foundation of China(No.51471056)the State Key Laboratory for Advanced Metal and Materials Foundation(No.2013-ZD06)the National Basic Research Program of China(No.2011CB605502)
文摘This study systematically compared the influences of yttrium（Y）,boron（B）,and carbon（C） on the microstructural refinement and properties of a Ti-43Al-5Nb alloy.The microstructural refinement effect in the TiAl alloy closely depends on the refiner used.The refinement effects of the three elements on colony size and lamellar thickness can be arranged as B 〉 Y 〉 C and Y 〉 C 〉 B,respectively.Moreover,a microstructure with a small grain size and ultra-fine lamellar spacing can be obtained by adding B and Y or B and C.The mechanical properties of TiAl alloy are also influenced by the refiners.TiAl alloys with proper B and Y contents exhibit favorable hot workability,tensile properties,and fracture toughness,whereas the C-containing alloy displays poor tensile properties and low fracture toughness.These results indicate that Y and B are more suitable microstructure refiners than C.This study may serve as a reference for practical alloying design.
基金Key Technology Research and Development Program of Shandong Province,China(No.2019GGX102060)the Chinese Postdoctoral Science Foundation(No.2017M612224).
基金supported by the National Key Research and Development Program of China(No.2017YFE0127700)the State Key Laboratory of Urban&Regional Ecology(No.SKLURE2017-2-4)。
文摘Heavy metal(Cu,Mn,Zn,Pb,and Cd)concentrations were measured in the leaves of Sabina chinensis and Platycladus orientalis collected from urban,suburban,and rural sites in Tianjin,China.Photosynthetic pigment contents,reactive oxygen species content,malondialdehyde(MDA)content and antioxidant enzyme activity were investigated,providing physiological response parameters.Our comparison of the sites revealed that urbanization significantly influenced the heavy metal concentrations in both plant leaves.At the rural site,both plant leaves exhibited the lowest heavy metal accumulation.The highest Cu,Mn,and Zn concentrations were found in S.chinensis leaves from the urban site;the highest Pb and Cd concentrations were found in P.orientalis leaves from the urban site.These results indicate that the urban site contained larger heavy metal concentrations in the plant leaves that may reflect the anthropogenic emission gradient.It is also found that S.chinensis may be used to monitor airborne heavy metal pollution because it is highly quick response to heavy metals,while P.orientalis may be used for mitigation due to its high resistance.The results of this study can contribute to the development of monitoring and environmental management plans by providing information on sensitive and resistant tree species for city greening in North China.
基金supported by the Program of Entrepreneurship and Innovation Ph.D.in Jiangsu Province(JSSCBS20211175)the School Ph.D.Talent Funding(Z301B2055)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(21KJB520002).
文摘3D human pose estimation is a major focus area in the field of computer vision,which plays an important role in practical applications.This article summarizes the framework and research progress related to the estimation of monocular RGB images and videos.An overall perspective ofmethods integrated with deep learning is introduced.Novel image-based and video-based inputs are proposed as the analysis framework.From this viewpoint,common problems are discussed.The diversity of human postures usually leads to problems such as occlusion and ambiguity,and the lack of training datasets often results in poor generalization ability of the model.Regression methods are crucial for solving such problems.Considering image-based input,the multi-view method is commonly used to solve occlusion problems.Here,the multi-view method is analyzed comprehensively.By referring to video-based input,the human prior knowledge of restricted motion is used to predict human postures.In addition,structural constraints are widely used as prior knowledge.Furthermore,weakly supervised learningmethods are studied and discussed for these two types of inputs to improve the model generalization ability.The problem of insufficient training datasets must also be considered,especially because 3D datasets are usually biased and limited.Finally,emerging and popular datasets and evaluation indicators are discussed.The characteristics of the datasets and the relationships of the indicators are explained and highlighted.Thus,this article can be useful and instructive for researchers who are lacking in experience and find this field confusing.In addition,by providing an overview of 3D human pose estimation,this article sorts and refines recent studies on 3D human pose estimation.It describes kernel problems and common useful methods,and discusses the scope for further research.
基金the National Natural Science Foundation of China(Nos.51861031 and 51604159)the Natural Science Foundation of Ningxia,China(No.2018AAC03056).
文摘The quasi-metallic fibers were selected from 1 to 40 pieces and connected in parallel in this study.The giant magneto impedance(GMI)effect of Co-based melt extract fibers in the bundle mode was investigated,and the distribution of the surface circumferential magnetic field on the fibers was also analyzed.Such distribution was induced by the driving current,which gave rise to the circular magnetization process and the GMI effect.The improved GMI effect with much higher field sensitivity was observed in these fiber bundles.Results show that the field sensitivities of the four-fiber and six-fiber bundles reach 19.5 V·m·kA−1(at 1 MHz)and 30.8 V·m·kA−1(at 5 MHz).The circumferential magnetic field distributed throughout the fiber’s circumferential surface is rearranged and becomes uneven due to the magnetic interaction among fibers.There are both strengthened and weakened magnetic field parts around these fibers’surfaces.The strengthened magnetic field improves the circumferential domain magnetization of the surface,resulting in larger GMI effects.However,the weakened parts inhibit the circumferential magnetization process and,therefore,the GMI effect.This also induces greater magnetization damp because of the increased domain interactions under the strong skin effect.The co-effect between the magnetic domains and the circumferential magnetization induces the optimization of the GMI effect in the four-fiber bundles.The observed GMI effect proves that fibers in bundle form can modify the sensitivity of the GMI effect.Moreover,different fiber bundles could be tuned according to the working conditions in order to manipulate the GMI response.
文摘Mineral potential assessment at the Earth’s surface has been an important research for geoscientists around the world in the past five decades. The fundamental aspects of mineral assessment at different scales can be associated with the following tasks, e.g., mineral potential mapping and estimation of mineral resources. This paper summarized the history and development in terms of theories, methods technologies and software platforms for quantitative assessment of mineral resources in China, e.g. comprehensive information methodology, geological anomaly, three-component quantitative prediction method, 5P orefinding area, integrated information assessment method, nonlinear process modeling and fractals, three dimensional mineral potential mapping, etc. At last, to discuss the future of quantitative mineral assessment in an era of big data including platform for 3D visualization, analysis and sharing, new methods and protocols for data cleaning, information enhancement, information integration, and uncertainties and multiple explanations of multi-information.
基金the National Natural Science Foundation of China(Grant Nos.:52071228,51704174,51801112)the Natural Science Foundation of Shanxi Province(Grant Nos.:201903D121056 and 201903D421084)the Shandong Province Key Research and Development Program(Grant No.:2019GGX102045)。
文摘The microstructure and cellular transition characteristics of an intermetallic Ti-42Al-3Nb-1Mo-0.1B (at.%) alloy were investigated.The as-cast microstructure of the alloy is mainly composed of (α2+γ) lamellar structure and (β+γ) mixture structure,which distributes along the boundaries of the lamellar colonies.In order to study the phase transformation of lamellar structure at aging temperature,a two-step heat treatment was carried out.After the first step of annealing treatment at 1,260 °C,the microstructure with relatively finer lamellar space and (γ+β/B2) mixture structure is obtained.Aging treatment,as the second heat treatment step,has significant influence on the microstructure,attributing to a cellular reaction of α2+γ→γ+β.With the increase of aging temperature,the (α2+γ) lamellar structure continues to dissolve,whereas the contents of both the equiaxed γ and β/B2 grains continuously increase.Besides,the orientation of lamellae α2,equiaxed γ and equiaxed β/B2 in the cellular transition region follows a specific relationship of {0-11}β<1-11>β//{0001}α2<2-1-10>α2//{1-11}γ<-101>γ.
基金supported by the National Natural Science Foundation of China (10732010,10972010 and 11028206)
文摘In this study, the 3-dimensional discrete element method is firstly introduced to explain the fracturing damage process of the dynamic split experiment of a special brittle glass ZnS. The corresponding dynamic split experiment is also performed by using the split Hopkinson pressure bar. Then the numerical results correspond closely to those obtained by experiments, and the fracturing damage mode shows that the sample under high strain rate loading would crack along vertical diameter in the band region between two loading edges, which differs from the static damage mode. Furthermore, by comparing a group of contrast numerical tests, the numerical results prove that loading area upon the top side of samples would influence the fracture mode of dynamic split experiments, which indicates that the narrow loading plane is better.
基金National High Level Hospital Clinical Research Funding(Nos.2022-PUMCH-B-088 and 2022-PUMCH-B-032)
文摘To the Editor:Meat is an important source of protein and could be roughly classied into red and white meat.White meat,which encompasses poultry,seafood such assh and shrimp,and reptiles,etc.,is characterized by its pale color when uncooked.Red meat is basically mammalian meat,including domestic animal meats,such as pork,beef,lamb,and wild animal meat in certain regions,such as kangaroos,seals,and whales.Uncooked mammalian meat appears red due to the presence of myoglobin in skeletal muscles.The clinical presentations of mammalian meat allergy comprise two types of allergic reactions,immediatetype and delayed-type,although both are mediated by immunoglobulin E(IgE).The immediate-type hypersensitivity manifests as allergic symptoms occurring shortly after ingestion of red meat and is primarily triggered by serum albumin and immunoglobulin which are the major allergenic components.This is the classic pattern of food allergy.The delayed-type hypersensitivity is characterized by delayed onset of allergic symptoms 2-6 h after red meat ingestion and is mediated by oligosaccharideα-gal-specic IgE which is a recently discoveried pattern of food allergy.
基金This work was supported by the China Mega-project for Infectious Diseases(2018ZX10713002 and 2018ZX10301401)Natural Science Foundation of China(81825019 and 82073617)Peking University Medicine Fund of Fostering Young Scholars’ Scientific and Technological Innovation.
文摘Background: Severe fever with thrombocytopenia (SFTS) caused by SFTS virus (SFTSV) was a tick-borne hemorrhagic fever that posed significant threat to human health in Eastern Asia. The study was designed to measure the seroprevalence of SFTSV antibody in healthy population residing in a high endemic region.Methods: A cohort study was performed on healthy residents in Shangcheng County in Xinyang City from April to December in 2018, where the highest SFTS incidence in China was reported. Anti-SFTSV IgG was measured by indirect enzyme-linked immunosorbent assay and neutralizing antibody (NAb) was detected by using PRNT50. The logistic regression models were performed to analyze the variables that were associated with seropositive rates.Results: Totally 886 individuals were recruited. The baseline seroprevalence that was tested before the epidemic season was 11.9% (70/587) for IgG and 6.8% (40/587) for NAb, which was increased to 13.4% (47/350) and 7.7% (27/350) during the epidemic season, and further to 15.8% (80/508) and 9.8% (50/508) post epidemic. The IgG antibody-based seropositivity was significantly related to the patients aged ≥ 70 years old [adjusted odds ratio (OR) = 2.440, 95% confidence interval (CI): 1.334-4.461 compared to the group of < 50 years old,P = 0.004], recent contact with cats (adjustedOR = 2.195, 95%CI: 1.261-3.818,P = 0.005), and working in tea garden (adjustedOR = 1.698, 95%CI: 1.002-2.880,P = 0.049) by applying multivariate logistic regression model. The NAb based seropositivity was similarly related to the patients aged ≥ 70 years old (adjustedOR = 2.691, 95%CI: 1.271-5.695 compared to the group of < 50 years old,P = 0.010), and recent contact with cats (OR = 2.648, 95%CI: 1.419-4.941,P = 0.002). For a cohort of individuals continually sampled with 1-year apart, the anti-SFTSV IgG were maintained at a stable level, while the NAb level reduced.Conclusions: Subclinical infection might not provide adequate immunity to protect reinfection of SFTSV, thus highlighting the ongoing threats of SFTS in endemic regions, which called for an imperative need for vaccine development. Identification of risk factors might help to target high-risk population for public health education and vaccination in the future.
基金This work was supported by the Natural Science Foundation of China(81825019 to W.L.,81722041 to H.L.,and 31970165 to L.K.Z.)the China Mega-project for Infectious Diseases(2018ZX10713002 and 2018ZX10301401 to W.L.)+1 种基金the Beijing Leading Talents in Science and Technology(Z181100006318008 to W.L.)Y.Y.was supported by NIH grants(R37 AI32042-19 and R01 AI139761).
文摘Severe fever with thrombocytopenia syndrome(SFTS)virus(SFTSV)is an emerging tick-borne virus with high fatality and an expanding endemic.Currently,effective anti-SFTSV intervention remains unavailable.Favipiravir(T-705)was recently reported to show in vitro and in animal model antiviral efficacy against SFTSV.Here,we conducted a single-blind,randomized controlled trial to assess the efficacy and safety of T-705 in treating SFTS(Chinese Clinical Trial Registry website,number ChiCTR1900023350).From May to August 2018,laboratory-confirmed SFTS patients were recruited from a designated hospital and randomly assigned to receive oral T-705 in combination with supportive care or supportive care only.Fatal outcome occurred in 9.5%(7/74)of T-705 treated patients and 18.3%(13/71)of controls(odds ratio,0.466,95%Cl,0.174-1.247).Cox regression showed a significant reduction in case fatality rate(CFR)with an adjusted hazard ratio of 0.366(95%Cl,0.142-0.944).Among the low-viral load subgroup(RT-PCR cycle threshold>26),T-705 treatment significantly reduced CFR from 11.5 to 1.6%(P=0.029),while no between-arm difference was observed in the high-viral load subgroup(RT-PCR cycle threshold<26).The T-705-treated group showed shorter viral clearance,lower incidence of hemorrhagic signs,and faster recovery of laboratory abnormities compared with the controls.The in vitro and animal experiments demonstrated that the antiviral efficacies of T-705 were proportionally induced by SFTSV mutation rates,particularly from two transition mutation types.The mutation analyses on T-705-treated serum samples disclosed a partially consistent mutagenesis pattern as those of the in vitro or animal experiments in reducing the SFTSV viral loads,further supporting the anti-SFTSV effect of T-705,especially for the low-viral loads.
基金supported by National Natural Science Foundation of China under Grant No.71490723.
文摘Low-carbon economy is gaining growing attention nowadays as global warming intensifies.As a market-based policy,emission trading policy is widely considered an effective means to achieve the doublewin of economic development and environmental protection.Under such circumstances,carbon trading markets are developing rapidly in many countries and regions,demanding more attention to compliance strategy issues for emission-intensive companies.In this study,we build a dynamic programming model in search of the optimal emission trading and technology investment decisions for a make-to-order company faced with a stochastic demand under emission trading policy.After a comprehensive analysis of the proposed model,we find that an optimal emission permit level,which increases in carbon penalty and decreases in carbon price,exists in each period.As for the abatement technology investment decision,the firm should invest only ff the investment cost per unit of abatement effort is less than a certain threshold,which increases in carbon penalty and carbon price.On the basis of a two-period dynamic programming model,we further explore the problem of investment timing.Results show how optimal investment decisions are influenced by the speed of technology progress under different parameters.These findings are important for firms to choose the time of investment depending on specific situations.
文摘Background:Severe fever with thrombocytopenia syndrome(SFTS),an emerging tickborne infectious disease caused by a novel banyangvirus(SFTS virus,SFTSV),was endemic in several Asian countries with a high mortality up to 30%.Until recently,SFTSV-associated re-infection have not been reported and investigated.
基金funded by the Natural Science Foundation of China(31901654)the Natural Science Foundation of Jiangsu Province(BK20190592).
文摘The purpose of this work was to investigate the differences in the anti-oxidative stress and anti-inflammatory effects between all-E(trans)-lutein and its 9Z(cis)-and 13Z-isomers using the human intestinal Caco-2 cell model.I-TiO_(2) catalyst was used to isomerize all-E-lutein to obtain 9Z-lutein and 13Z-lutein.In anti-oxidative stress studies,all three lutein isoforms could significantly reduce H2O_(2)-induced interleukin-8(IL-8)and tumor necrosis factor-α(TNF-α)secretion(p<0.05)by 50%or more at 4μM.At lower concentration(2μM),9Z-lutein and 13Z-lutein showed higher protection against oxidative stress than all-E-lutein by significantly reducing IL-8 secretion by 48%and 40%(p<0.05),respectively.In addition,three lutein isomers,especially 9Z-lutein could up-regulate the activity of antioxidant enzymes including catalase(CAT),glutathione peroxidase(GPx),gluta-thione reductase(GR),and the content of endogenous antioxidant glutathione(GSH)at 2μM.In the anti-inflammatory assay,9Z-lutein and all-E-lutein exhibited higher anti-inflammatory effects than 13Z-lutein in reducing the secretion and expression of IL-8 in TNF-αinduced inflammatory Caco-2 cells.Compared with the positive control,9Z-lutein and all-E-lutein could reduce the expression of the IL-8 gene by 49%and 52%,respectively at 4μM.This study provided a theoretical basis for the potential health benefits of Z-luteins.
