This study presents an achievement of laser cooling of alkaline-earth atoms in the Chinese Space Station’s strontium(Sr)atomic space optical clock.The system’s core components,physical unit,optical unit,and electric...This study presents an achievement of laser cooling of alkaline-earth atoms in the Chinese Space Station’s strontium(Sr)atomic space optical clock.The system’s core components,physical unit,optical unit,and electrical unit,have a total volume of 306 L and a total mass of 163.8 kg.These compact and robust units can overcome mechanical vibrations and temperature fluctuations during space launch.The laser sources of the optical unit are composed of diode lasers,and the injection locking of slave lasers is automatically performed by a program.In the experiment,a blue magneto-optical trap of cold atoms was achieved,with the atom numbers estimated to be approximately(1.50±0.13)×10^(6) for 87Sr and(8.00±0.56)×10^(6) for 88Sr.This work establishes a foundation for atomic confinement and high-precision interrogation in space-based optical clocks and expands the frontiers of cold atom physics in microgravity.展开更多
Two kinds of NiCrAlY coatings(Ni-25Cr-10Al-0.5Y)were prepared on K417 superalloy using ion plating(AIP)and magnetron sputtering(MS),respectively.The isothermal and cyclic oxidation behaviors of the two NiCrAlY coating...Two kinds of NiCrAlY coatings(Ni-25Cr-10Al-0.5Y)were prepared on K417 superalloy using ion plating(AIP)and magnetron sputtering(MS),respectively.The isothermal and cyclic oxidation behaviors of the two NiCrAlY coatings were evaluated at 1323 K in stair air.The results revealed that the nanocrystalline NiCrAlY coating exhibited better isothermal and cyclic oxidation resistance compared to the conventional NiCrAlY at 1323 K.The mass gain and parabolic rate constant Kp of the nanocrystalline NiCrAlY coating were 45.2%and 44.7%lower than those of the conventional NiCrAlY coating,respectively.During cyclic oxidation,the tendency for spallation of the oxide scale was evidently decreased by nanocrystallization due to the formation of a continuous,compact,adherent,and slow-growing exclusiveα-Al_(2)O_(3)scale.The mechanism responsible for the improvement of the nanocrystalline NiCrAlY coating was discussed.展开更多
There is no safe level of exposure to air pollution,including particulate matter smaller than2.5μm(PM_(2.5)),to human health.Whilst it is well known that exposure to heavily polluted air is associated with several li...There is no safe level of exposure to air pollution,including particulate matter smaller than2.5μm(PM_(2.5)),to human health.Whilst it is well known that exposure to heavily polluted air is associated with several liver disorders,it is unclear how long-term exposure to lowlevel traffic-derived PM_(2.5)affects liver health.BALB/c mice(5 weeks,male)were exposed to traffic-derived PM_(2.5)(10μg/mouse/day,intranasally)daily for 4,8 and 12 weeks.Markers of inflammation and fibrosis were measured at each time point.Changes in liver proteome and lipid profiles were measured using proteomics and lipidomics at 12 weeks.Low-dose PM_(2.5)exposure increased macrophage infiltration,pro-inflammatory cytokine production,and increased collagen deposition at 12 weeks.Despite liver lipid metabolism being increased,the abundance of triglycerides,precursor diacylglycerols,and ceramide was also significantly increased by PM_(2.5)exposure,whereas glycogen content was reduced.Proteomics analysis revealed 64 proteins to be significantly changed in PM_(2.5)-exposed mice,and KEGG pathway enrichment analysis indicated their involvement in lipid metabolism,alcohol-related liver disease,neutrophil extracellular trap formation,and transcriptional dysregulation related to cancer.In conclusion,prolonged exposure to low-dose traffic-derived PM_(2.5)promotes pathological changes in the liver,suggestive of an increased risk of metabolic dysfunctionassociated fatty liver disease.Future studies can enable the identification of the signalling pathways underlying low-dose PM_(2.5)-induced lipid accumulation in the liver.展开更多
This study sheds light on how pore structure characteristics and varying dynamic pressure conditions influence the permeability of tight sandstone reservoirs,with a particular focus on the Paleozoic reservoirs in the ...This study sheds light on how pore structure characteristics and varying dynamic pressure conditions influence the permeability of tight sandstone reservoirs,with a particular focus on the Paleozoic reservoirs in the Qingshimao Gas Field.Using CT scans of natural core samples,a three-dimensional digital core was constructed.The maximum ball method was applied to extract a related pore network model,and the pore structure characteristics of the core samples,such as pore radius,throat radius,pore volume,and coordination number,were quantitatively evaluated.The analysis revealed a normally distributed pore radius,suggesting a high degree of reservoir homogeneity and favorable conditions for a connected pore system.However,it was found that the majority of throat radii measured less than 1μm,which severely restricted fluid flow and diminished permeability.Over 50%of the pores measured under 100μm^(3),further constraining fluid movement.Additionally,30%-50%of the pore network was composed of isolated and blind-end pores,which significantly impaired formation connectivity and reduced permeability.Based on this,the lattice Boltzmann method(LBM)was used for pore-scale flow simulation to investigate the influence mechanism of pore structure characteristics and dynamic-static parameters such as displacement pressure difference on the permeability performance of the considered tight sandstone reservoirs for various pressure gradients(0.1,1,and 10 MPa).The simulations revealed a strong relationship between pressure differential and both the number of streamlines and flow path tortuosity.When the pressure differential increased to 1 MPa,30 streamlines were observed,with a tortuosity factor of 1.5,indicating the opening of additional seepage channels and the creation of increasingly winding flow paths.展开更多
Advanced Spaceborne Thermal Emission and Reflection Radiometer （ASTER） data covering the Jiafushaersu area in Xinjiang were used for mapping lithology and hydrothermal alteration. The study area situates at a potent...Advanced Spaceborne Thermal Emission and Reflection Radiometer （ASTER） data covering the Jiafushaersu area in Xinjiang were used for mapping lithology and hydrothermal alteration. The study area situates at a potential mineralization zone in relation to small hypabyssai granodiorite or quartz monzonite intrusions along the margin of granitoid batholiths of Darbut foot wall. The false colour composition of bands 521 and the first three principal component analyses （PCA1, PCA2, PCA3） in RGB identify the lithological units and discriminate the small intrusions very well from the adjacent granitoid batholiths. PCA and spectral angle mapper （SAM） algorithm were employed to discriminate alteration minerals. The results indicate that the hydroxyl-bearing or ferric and less commonly carbonate types show good correlation with the quartz monzonite porphyry and aplite. Field verification led to finding of the Jiafushaersu molybdenum mineralization. The lithological and geochemical features imply that the molybdenum mineralization is close to the porphyry type. This study further verified that the foot wall of the Darbut suture could have served as a more important metallogenic district for the porphyry copper and molybdenum deposits. It is concluded that the ASTER data-based methods can be used as a powerful tool for small intrusion-type mineral resources targeting.展开更多
目前无监督的泛化行人重识别算法在某些需要背景信息辅助判断的情况下,可能会忽视图像的局部区域对细粒度特征的关注,导致背景信息被过滤掉,从而降低识别精度。针对上述问题,提出了一种基于稀疏注意力的动态查询感知算法。通过挤压拼接(...目前无监督的泛化行人重识别算法在某些需要背景信息辅助判断的情况下,可能会忽视图像的局部区域对细粒度特征的关注,导致背景信息被过滤掉,从而降低识别精度。针对上述问题,提出了一种基于稀疏注意力的动态查询感知算法。通过挤压拼接(squeeze and concat,SPC)模块,获取不同通道数的特征图。利用双层路由感知注意力机制,提取不同尺度特征图之间的注意力权重,得到逐级通道注意力向量。对逐级通道注意力向量的权重进行重新校准。将重新标定的权重与相应的特征图进行加权,输出具有更丰富细化特征信息的多尺度特征图。所提模型在大规模公开数据集(Market-1501、DukeMTMC-reID、MSMT17)上进行实验,相较于基线模型Rank-1分别提高了3.2、4.4、15.4个百分点,mAP分别提高了5.5、8.3、16.2个百分点,与现有前沿算法相比,能够实现更好的局部和全局特征通道之间的信息交互,提升模型对图像特征的细节感知能力.展开更多
There are various types of traumatic stimuli,such as catastrophic events like wars,natural calamities like earthquakes,and personal trauma from physical and psychological neglect or abuse and sexual abuse.Traumatic ev...There are various types of traumatic stimuli,such as catastrophic events like wars,natural calamities like earthquakes,and personal trauma from physical and psychological neglect or abuse and sexual abuse.Traumatic events can be divided into type I and type II trauma,and their impacts on individuals depend not only on the severity and duration of the traumas but also on individuals’self-evaluation of the traumatic events.Individual stress reactions to trauma include posttraumatic stress disorder(PTSD),complex PTSD and trauma-related depression.Trauma-related depression is a reactive depression with unclear pathology,and depression occurring due to trauma in the childhood has gained increasing attention,because it has persisted for a long time and does not respond to conventional antidepressants but shows good or partial response to psychotherapy,which is similar to the pattern observed for PTSD.Because trauma-related depression is associated with high risk of suicide and is chronic with a propensity to relapse,it is necessary to explore its pathogenesis and therapeutic strategy.展开更多
In order to stagger the early harvest stage of daylily and critical busy summer farming season in Qingyang City, late-maturing daylily cultivar Jinlei No. 1 was systematically bred from natural variant offspring of Ma...In order to stagger the early harvest stage of daylily and critical busy summer farming season in Qingyang City, late-maturing daylily cultivar Jinlei No. 1 was systematically bred from natural variant offspring of Malian daylily. According to the results, late-maturing daylily eultivar Jinlei No. 1 exhibited good agro- nomic traits and strong resistance, The first day of harvest of Jinlei No. 1 was more than 10 d later compared with Malian daylily and Xian daylily ; harvest duration of Jinlei No. 1 was 4 d longer than Malian daylily and 5 d than Xian daylily; the yield of Jinlei No. 1 was improved by 3.41% and 5.16% compared with Malian daylily and Xian daylily, respectively. The cultivation of late-maturing daylily cuhivar Jinlei No. 1 can effectively avoid heavy economic losses caused by overlap period of early harvest of daylily and critical busy summer farming in Qingyang City.展开更多
CD36 is a highly glycosylated integral membrane protein that belongs to the scavenger receptor class B family and regulates the pathological progress of metabolic diseases.CD36 was recently found to be widely expresse...CD36 is a highly glycosylated integral membrane protein that belongs to the scavenger receptor class B family and regulates the pathological progress of metabolic diseases.CD36 was recently found to be widely expressed in various cell types in the nervous system,including endothelial cells,pericytes,astrocytes,and microglia.CD36 mediates a number of regulatory processes,such as endothelial dysfunction,oxidative stress,mitochondrial dysfunction,and inflammatory responses,which are involved in many central nervous system diseases,such as stroke,Alzheimer’s disease,Parkinson’s disease,and spinal cord injury.CD36 antagonists can suppress CD36 expression or prevent CD36 binding to its ligand,thereby achieving inhibition of CD36-mediated pathways or functions.Here,we reviewed the mechanisms of action of CD36 antagonists,such as Salvianolic acid B,tanshinone IIA,curcumin,sulfosuccinimidyl oleate,antioxidants,and small-molecule compounds.Moreover,we predicted the structures of binding sites between CD36 and antagonists.These sites can provide targets for more efficient and safer CD36 antagonists for the treatment of central nervous system diseases.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB35010202)the National Natural Science Foundation of China(Grants No.62275268)。
文摘This study presents an achievement of laser cooling of alkaline-earth atoms in the Chinese Space Station’s strontium(Sr)atomic space optical clock.The system’s core components,physical unit,optical unit,and electrical unit,have a total volume of 306 L and a total mass of 163.8 kg.These compact and robust units can overcome mechanical vibrations and temperature fluctuations during space launch.The laser sources of the optical unit are composed of diode lasers,and the injection locking of slave lasers is automatically performed by a program.In the experiment,a blue magneto-optical trap of cold atoms was achieved,with the atom numbers estimated to be approximately(1.50±0.13)×10^(6) for 87Sr and(8.00±0.56)×10^(6) for 88Sr.This work establishes a foundation for atomic confinement and high-precision interrogation in space-based optical clocks and expands the frontiers of cold atom physics in microgravity.
基金financially supported by the National Natural Science Foundation of China(No.52101075)China Postdoctoral Science Foundation(Nos.2021M700557,2022M723272)+1 种基金Postdoctoral Scienceof Chongqing Natural Science Foundation(Nos.cstc2021jcyj-bshX0053,cstc2021jcyj-bshX0039)Scientific Research Foundation of Chongqing University of Technology(No.2020ZDZ004)。
文摘Two kinds of NiCrAlY coatings(Ni-25Cr-10Al-0.5Y)were prepared on K417 superalloy using ion plating(AIP)and magnetron sputtering(MS),respectively.The isothermal and cyclic oxidation behaviors of the two NiCrAlY coatings were evaluated at 1323 K in stair air.The results revealed that the nanocrystalline NiCrAlY coating exhibited better isothermal and cyclic oxidation resistance compared to the conventional NiCrAlY at 1323 K.The mass gain and parabolic rate constant Kp of the nanocrystalline NiCrAlY coating were 45.2%and 44.7%lower than those of the conventional NiCrAlY coating,respectively.During cyclic oxidation,the tendency for spallation of the oxide scale was evidently decreased by nanocrystallization due to the formation of a continuous,compact,adherent,and slow-growing exclusiveα-Al_(2)O_(3)scale.The mechanism responsible for the improvement of the nanocrystalline NiCrAlY coating was discussed.
基金supported by a project grant awarded to Hui Chen and Brian G.Oliver by the Australian National Health&Medical Research Council(No.APP1158186)supported by scholarships from the Chinese Scholarship Councilsupported by scholarships from the Australian Government Research Training Program。
文摘There is no safe level of exposure to air pollution,including particulate matter smaller than2.5μm(PM_(2.5)),to human health.Whilst it is well known that exposure to heavily polluted air is associated with several liver disorders,it is unclear how long-term exposure to lowlevel traffic-derived PM_(2.5)affects liver health.BALB/c mice(5 weeks,male)were exposed to traffic-derived PM_(2.5)(10μg/mouse/day,intranasally)daily for 4,8 and 12 weeks.Markers of inflammation and fibrosis were measured at each time point.Changes in liver proteome and lipid profiles were measured using proteomics and lipidomics at 12 weeks.Low-dose PM_(2.5)exposure increased macrophage infiltration,pro-inflammatory cytokine production,and increased collagen deposition at 12 weeks.Despite liver lipid metabolism being increased,the abundance of triglycerides,precursor diacylglycerols,and ceramide was also significantly increased by PM_(2.5)exposure,whereas glycogen content was reduced.Proteomics analysis revealed 64 proteins to be significantly changed in PM_(2.5)-exposed mice,and KEGG pathway enrichment analysis indicated their involvement in lipid metabolism,alcohol-related liver disease,neutrophil extracellular trap formation,and transcriptional dysregulation related to cancer.In conclusion,prolonged exposure to low-dose traffic-derived PM_(2.5)promotes pathological changes in the liver,suggestive of an increased risk of metabolic dysfunctionassociated fatty liver disease.Future studies can enable the identification of the signalling pathways underlying low-dose PM_(2.5)-induced lipid accumulation in the liver.
文摘This study sheds light on how pore structure characteristics and varying dynamic pressure conditions influence the permeability of tight sandstone reservoirs,with a particular focus on the Paleozoic reservoirs in the Qingshimao Gas Field.Using CT scans of natural core samples,a three-dimensional digital core was constructed.The maximum ball method was applied to extract a related pore network model,and the pore structure characteristics of the core samples,such as pore radius,throat radius,pore volume,and coordination number,were quantitatively evaluated.The analysis revealed a normally distributed pore radius,suggesting a high degree of reservoir homogeneity and favorable conditions for a connected pore system.However,it was found that the majority of throat radii measured less than 1μm,which severely restricted fluid flow and diminished permeability.Over 50%of the pores measured under 100μm^(3),further constraining fluid movement.Additionally,30%-50%of the pore network was composed of isolated and blind-end pores,which significantly impaired formation connectivity and reduced permeability.Based on this,the lattice Boltzmann method(LBM)was used for pore-scale flow simulation to investigate the influence mechanism of pore structure characteristics and dynamic-static parameters such as displacement pressure difference on the permeability performance of the considered tight sandstone reservoirs for various pressure gradients(0.1,1,and 10 MPa).The simulations revealed a strong relationship between pressure differential and both the number of streamlines and flow path tortuosity.When the pressure differential increased to 1 MPa,30 streamlines were observed,with a tortuosity factor of 1.5,indicating the opening of additional seepage channels and the creation of increasingly winding flow paths.
基金supported by the Special Fund for Basic Scientific Research of Central Colleges of China (Nos. CHD2011SY013, 2013G1271103)Chang’an University, China and the Central University Foundation of China (Nos. CHD2011ZY005, CHD2011JC168)
文摘Advanced Spaceborne Thermal Emission and Reflection Radiometer （ASTER） data covering the Jiafushaersu area in Xinjiang were used for mapping lithology and hydrothermal alteration. The study area situates at a potential mineralization zone in relation to small hypabyssai granodiorite or quartz monzonite intrusions along the margin of granitoid batholiths of Darbut foot wall. The false colour composition of bands 521 and the first three principal component analyses （PCA1, PCA2, PCA3） in RGB identify the lithological units and discriminate the small intrusions very well from the adjacent granitoid batholiths. PCA and spectral angle mapper （SAM） algorithm were employed to discriminate alteration minerals. The results indicate that the hydroxyl-bearing or ferric and less commonly carbonate types show good correlation with the quartz monzonite porphyry and aplite. Field verification led to finding of the Jiafushaersu molybdenum mineralization. The lithological and geochemical features imply that the molybdenum mineralization is close to the porphyry type. This study further verified that the foot wall of the Darbut suture could have served as a more important metallogenic district for the porphyry copper and molybdenum deposits. It is concluded that the ASTER data-based methods can be used as a powerful tool for small intrusion-type mineral resources targeting.
文摘目前无监督的泛化行人重识别算法在某些需要背景信息辅助判断的情况下,可能会忽视图像的局部区域对细粒度特征的关注,导致背景信息被过滤掉,从而降低识别精度。针对上述问题,提出了一种基于稀疏注意力的动态查询感知算法。通过挤压拼接(squeeze and concat,SPC)模块,获取不同通道数的特征图。利用双层路由感知注意力机制,提取不同尺度特征图之间的注意力权重,得到逐级通道注意力向量。对逐级通道注意力向量的权重进行重新校准。将重新标定的权重与相应的特征图进行加权,输出具有更丰富细化特征信息的多尺度特征图。所提模型在大规模公开数据集(Market-1501、DukeMTMC-reID、MSMT17)上进行实验,相较于基线模型Rank-1分别提高了3.2、4.4、15.4个百分点,mAP分别提高了5.5、8.3、16.2个百分点,与现有前沿算法相比,能够实现更好的局部和全局特征通道之间的信息交互,提升模型对图像特征的细节感知能力.
基金Supported by the Science and Technology Project of Zhejiang Provincial,No.GF22H093655Nonprofit Applied Research Project of Huzhou Science and Technology Bureau,2021GYB16.
文摘There are various types of traumatic stimuli,such as catastrophic events like wars,natural calamities like earthquakes,and personal trauma from physical and psychological neglect or abuse and sexual abuse.Traumatic events can be divided into type I and type II trauma,and their impacts on individuals depend not only on the severity and duration of the traumas but also on individuals’self-evaluation of the traumatic events.Individual stress reactions to trauma include posttraumatic stress disorder(PTSD),complex PTSD and trauma-related depression.Trauma-related depression is a reactive depression with unclear pathology,and depression occurring due to trauma in the childhood has gained increasing attention,because it has persisted for a long time and does not respond to conventional antidepressants but shows good or partial response to psychotherapy,which is similar to the pattern observed for PTSD.Because trauma-related depression is associated with high risk of suicide and is chronic with a propensity to relapse,it is necessary to explore its pathogenesis and therapeutic strategy.
基金Supported by National Spark Project of China(2012GA860011)Spark Project of Gansu Provincial Science and Technology Department(S2012G100009)
文摘In order to stagger the early harvest stage of daylily and critical busy summer farming season in Qingyang City, late-maturing daylily cultivar Jinlei No. 1 was systematically bred from natural variant offspring of Malian daylily. According to the results, late-maturing daylily eultivar Jinlei No. 1 exhibited good agro- nomic traits and strong resistance, The first day of harvest of Jinlei No. 1 was more than 10 d later compared with Malian daylily and Xian daylily ; harvest duration of Jinlei No. 1 was 4 d longer than Malian daylily and 5 d than Xian daylily; the yield of Jinlei No. 1 was improved by 3.41% and 5.16% compared with Malian daylily and Xian daylily, respectively. The cultivation of late-maturing daylily cuhivar Jinlei No. 1 can effectively avoid heavy economic losses caused by overlap period of early harvest of daylily and critical busy summer farming in Qingyang City.
基金supported by the National Major Project of Research and Development,No.2022YFA1105500(to SZ)the National Natural Science Foundation of China,No.81870975(to SZ)Innovation Program for Graduate Students in Jiangsu Province of China,No.KYCX223335(to MZ)。
文摘CD36 is a highly glycosylated integral membrane protein that belongs to the scavenger receptor class B family and regulates the pathological progress of metabolic diseases.CD36 was recently found to be widely expressed in various cell types in the nervous system,including endothelial cells,pericytes,astrocytes,and microglia.CD36 mediates a number of regulatory processes,such as endothelial dysfunction,oxidative stress,mitochondrial dysfunction,and inflammatory responses,which are involved in many central nervous system diseases,such as stroke,Alzheimer’s disease,Parkinson’s disease,and spinal cord injury.CD36 antagonists can suppress CD36 expression or prevent CD36 binding to its ligand,thereby achieving inhibition of CD36-mediated pathways or functions.Here,we reviewed the mechanisms of action of CD36 antagonists,such as Salvianolic acid B,tanshinone IIA,curcumin,sulfosuccinimidyl oleate,antioxidants,and small-molecule compounds.Moreover,we predicted the structures of binding sites between CD36 and antagonists.These sites can provide targets for more efficient and safer CD36 antagonists for the treatment of central nervous system diseases.
