The ultra-high strength Cu-20Ni-20 Mn alloy was prepared by vacuum melting and its mechanical property and corrosion behavior were investigated. After thermomechanical treatment, the alloy exhibited an ultra-high tens...The ultra-high strength Cu-20Ni-20 Mn alloy was prepared by vacuum melting and its mechanical property and corrosion behavior were investigated. After thermomechanical treatment, the alloy exhibited an ultra-high tensile strength of 1204 MPa and the applicable elongation of up to 6.2%. With the increasing exposure time in 3.5% Na Cl solution, the corrosion current of the alloy decreased, while the polarization resistance and the charge-transfer resistance of the corrosion surface increased. The corrosion products formed on the surface of the alloy exposed for 1 d, and further corrosion made the corrosion product layer much dense, increasing the corrosion resistance and protecting the alloy from further corrosion.展开更多
Based on the thermal and velocity layer's theory,the experimental setup was established on large space atrium under nozzle outlet. A series of winter experiments were accomplished and the following conclusions cou...Based on the thermal and velocity layer's theory,the experimental setup was established on large space atrium under nozzle outlet. A series of winter experiments were accomplished and the following conclusions could be drawn. At the sunny day of winter in Shanghai,the thermal and velocity layer are similar. The height of the both layer is 10-30 mm,and the temperature gratitude is 5-10 ℃ /m. Decreasing the angle of the nozzle outlet can increase the layer height dramatically. The maximum temperature difference of the occupant zone has relation with the angle of the nozzle outlet. The less the angle of the nozzle outlet is set,the greater the temperature difference is. The occupant temperature differences at these angles of the nozzle outlet are 5.1-4.4 ℃. The velocity of the wind is 0.02 and 0.17 m/s and they can accord with design demand. So,it can decrease the temperature gratitude by about 30% and it can save 10%-15% energy consumption.展开更多
The stress corrosion crack （SCC） susceptibility of ultra-high strength steel AerMet 100 was investigated by slow strain rate technique （SSRT）, tensile with polarization and surface analysis technique. The curves o...The stress corrosion crack （SCC） susceptibility of ultra-high strength steel AerMet 100 was investigated by slow strain rate technique （SSRT）, tensile with polarization and surface analysis technique. The curves of tf^Cl/tf^W -strain rate are divided into three regions： stress-dominated region, SCC-dominated region, and corrosion-dominated region, so as the curves of εf^Cl/εf^W - strain rate and tm/tf-strain rate. The results of tensile tests with polarization show that the main SCC mechanism of AerMet 100 is anodic dissolution, which controls the corrosion process. The three regions have been discussed according to the relationship between the rate of slip-step formation and the rate of dissolution. Fracture appearances in different environments were analyzed by scanning electron microscopy （SEM）. SCC fracture appears as a mixture of intergranular and dimples, while it is totally dimples in the inert environment. The εf becomes the parameter to predict tf because the relationship between εf^Cl/εf^W and tf^Cl/tf^w is a straight line for AerMet 100.展开更多
The effects of chloride,sulfate and carbonate anions on stress corrosion behaviors of ultra-high strength steel 23Co14Ni12Cr3Mo were studied by stress corrosion cracking(SCC)test method using double cantilever beam(DC...The effects of chloride,sulfate and carbonate anions on stress corrosion behaviors of ultra-high strength steel 23Co14Ni12Cr3Mo were studied by stress corrosion cracking(SCC)test method using double cantilever beam(DCB)specimens.The SCC morphology was observed by using scanning electron microscopy(SEM)and the composition of corrosion products was analyzed by using energy dispersive spectrometer(EDS).The results show that the crack propagates to bifurcation in NaCl and Na2SO4 solution,while the crack in Na2CO3 solution propagates along the load direction.The SCC rate in NaCl solution is the highest,while lower in Na2SO4 solution and little in Na2CO3 solution.From the SEM morphologies,quasi-cleavage fracture was observed in NaCl and Na2SO4 solutions,but intergranular features in Na2CO3 solution.The mechanism of anion effect on SCC of steel 23Co14Ni12Cr3Mo was studied by using full immersion test and electrochemical measurements.展开更多
In this study a 10-storied residential building model was employed to clarify the ventilation characteristics of the atrium and the rooms,which were effected by the different forms of lateral openings.The experiment w...In this study a 10-storied residential building model was employed to clarify the ventilation characteristics of the atrium and the rooms,which were effected by the different forms of lateral openings.The experiment was conducted under the combined effect of wind force and thermal buoyancy,and the similarity requirements were satisfied.The results have shown that the different forms of lateral openings cause the different ventilation effect of the building,and also have some certain regularity.The conclusions provide a theoretical foundation for how to use the ventilation of atrium better in high-rise residential building.展开更多
Five thyreostats(TSs),namely tapazole,thiouracil,methylthiouracil,propylthiouracil,and phenylthiouracil,were determined in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC...Five thyreostats(TSs),namely tapazole,thiouracil,methylthiouracil,propylthiouracil,and phenylthiouracil,were determined in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)in positive electrospray ionization mode.Extraction and clean-up were achieved using a ChemElut cartridge with tert-butyl methyl ether,without a derivatization step.Separation was achieved on an Acquity UPLC SS T3 column.The mobile phase was acetonitrile and water containing 0.2%(v/v)formic acid.The mass spectrometer was operated in multiple reaction monitoring mode.Urine samples were spiked with TS solution at levels corresponding to 5,10,15,and 20μg/L.The accuracy(internal standard corrected)ranged from 92%to 107%,with a repeatability precision(relative standard deviation,RSD)less than 15%for all five analytes.The RSDs within-laboratory reproducibility was less than 26%.The decision limits(CCα)and detection capabilities(CCβ)were obtained from a calibration curve and were in the ranges of 3.1-6.1μg/L and 4.0-7.4μg/L,respectively.The CCαand CCβvalues were below the recommended concentration,which was set at 10μg/L.The results show that the described method is suitable for the direct detection of TSs in bovine urine.This method can also be used to determine TSs in porcine urine.展开更多
Nano-Scale mapping of minerals and organic compounds give unprecedented high resolution information on the origin and nature of substances,and provide new insight on their correlative distribution and interaction,thus...Nano-Scale mapping of minerals and organic compounds give unprecedented high resolution information on the origin and nature of substances,and provide new insight on their correlative distribution and interaction,thus present a powerful tool to study the progressive changes of geological samples,and may even be applied to study extraterrestrial samples in search of life.One example we present here explore the use of elemental microprobe,X-Ray Photon Spectroscopy(XPS),and synchrotron-based Scanning Transmission X-ray Microscopy(STXM) coupled with Near Edge X-ray Absorption Fine Structure(NEXAFS) Spectroscopy to investigate the surface properties and stability of micron-size organic carbonaceous particles from Central Amazon,Brazil,specifically focusing on black carbon in Kaolinitic Oxisol originated from anthropogenic processes,and their interaction with cations.展开更多
右心房结构和功能在维持心血管系统稳态中扮演关键角色,其形态重构及功能异常与多种心血管疾病进程紧密相连。近年来,随着心脏磁共振(cardiac magnetic resonance,CMR)技术的快速发展,其在无创评估心脏解剖、功能及心肌组织病理特征方...右心房结构和功能在维持心血管系统稳态中扮演关键角色,其形态重构及功能异常与多种心血管疾病进程紧密相连。近年来,随着心脏磁共振(cardiac magnetic resonance,CMR)技术的快速发展,其在无创评估心脏解剖、功能及心肌组织病理特征方面展现出独特优势,为右心房功能的精确评价提供了新的视角和方法。本文重点阐述CMR评估右心房功能的常用参数并深入探讨其在多种心血管疾病中的临床应用,指出当前CMR在右心房功能评估领域的研究不足和挑战,指明未来研究方向。本文旨在提高对CMR评估右心房功能的全面认识,促进其在心血管疾病诊疗中的广泛应用,为疾病的早期诊断、病情评估及预后判断提供参考。展开更多
心脏分割算法提供精准把握心脏结构的信息,辅助医生进行诊断、制定治疗计划以及进行手术前的评估工作,提高临床治疗的效果并减轻并发症。然而,心脏分割在应用中存在诸多问题。手动分割方法不仅耗时费力,并且具有很强的主观意识。全监督...心脏分割算法提供精准把握心脏结构的信息,辅助医生进行诊断、制定治疗计划以及进行手术前的评估工作,提高临床治疗的效果并减轻并发症。然而,心脏分割在应用中存在诸多问题。手动分割方法不仅耗时费力,并且具有很强的主观意识。全监督的心脏分割方法虽已取得一定成果,但标注数据的依赖性过高。现有的半监督分割方法在处理复杂的心脏结构和病理变化时表现仍不够理想,难以在实际临床环境中稳定应用。为解决这一问题,提出了心脏磁共振成像(MRI)分割方法,结合Linformer and Performer merge V-Net(LPV-Net)和3D Enhanced Discriminator with Attention(3D-EDA)技术,实现了全局-局部信息的有效整合。LPV-Net模块由LinPerBlock和改进的V-Net联袂打造,旨在规范模型训练过程、实现全局与局部信息的有机整合,有效提高分割效果的准确性与鲁棒性。同时引入新鉴别器3D-EDA规范未标记数据,并加入关键模块CARE-Layer,集成自定义注意力模块以增强对特征重要信息的捕捉能力,辅助网络可提高主网络分割指标性能。在左心房数据集上进行综合实验,并将所提方法与MC-Net,V-Net等其他先进的半监督方法进行比较,发现该方法在基准数据集上的表现尤为优异。特别是在使用有限标签数据进行训练时,该方法仍然展示出卓越的性能;当仅使用10%和20%的标记数据进行训练时,该方法的Dice系数分别达到88.50%和90.39%。展开更多
目的:探讨不同强度耐力运动对大鼠心房Ⅰ型胶原蛋白(Col-I)和Ⅲ型胶原蛋白(Col-III)的影响,并研究结缔组织生长因子(CTGF)的表达变化,为探究运动性心房纤颤的发生机制提供依据。方法:24只健康雄性SD大鼠随机分为安静组、中强度组和大强...目的:探讨不同强度耐力运动对大鼠心房Ⅰ型胶原蛋白(Col-I)和Ⅲ型胶原蛋白(Col-III)的影响,并研究结缔组织生长因子(CTGF)的表达变化,为探究运动性心房纤颤的发生机制提供依据。方法:24只健康雄性SD大鼠随机分为安静组、中强度组和大强度组,每组8只。进行16周的运动训练,每周训练5天,每天1小时。16周末处死大鼠摘取心脏后分离出右心房,应用RT-PCR、免疫荧光化学和Western Blot技术测定Col-I、Col-III和CTGF基因与蛋白的表达。结果:与安静组相比,大强度组Col-I m RNA和蛋白的表达显著升高(P<0.05和P<0.01);Col-III m RNA增加但无显著性,蛋白表达显著性升高(P<0.01);Col-I/Col-III蛋白表达的比值显著升高(P<0.01);CTGF m RNA和蛋白的表达均显著升高(P<0.05)。与安静组相比,中强度组Col-I m RNA和蛋白的表达增加,但无统计学差异;Col-III m RNA表达显著性降低(P<0.01),蛋白表达无显著性变化;Col-I/Col-III蛋白表达比值增高,但无显著性;CTGF m RNA表达增高而蛋白表达降低,但均无显著性。结论:长期大强度运动可导致大鼠心房Col-I和Col-III显著增加、Col-I/Col-III比例发生失衡,可能与长期大强度运动诱导大鼠心房CTGF的表达增加有关,构成了运动性心房纤颤发生的重要病理机制之一。展开更多
基金Project(2017YFB0306105)supported by the National Key R&D Program of ChinaProjects(51601227,51701241)supported by the National Natural Science Foundation of China。
文摘The ultra-high strength Cu-20Ni-20 Mn alloy was prepared by vacuum melting and its mechanical property and corrosion behavior were investigated. After thermomechanical treatment, the alloy exhibited an ultra-high tensile strength of 1204 MPa and the applicable elongation of up to 6.2%. With the increasing exposure time in 3.5% Na Cl solution, the corrosion current of the alloy decreased, while the polarization resistance and the charge-transfer resistance of the corrosion surface increased. The corrosion products formed on the surface of the alloy exposed for 1 d, and further corrosion made the corrosion product layer much dense, increasing the corrosion resistance and protecting the alloy from further corrosion.
基金Project(09YZ229) supported by Innovation Program of Shanghai Municipal Education Commission, ChinaProject(J50502) supported by Leading Academic Discipline of Shanghai Municipal Education Commission,China+2 种基金Project(50478113) supported by the National Natural Science Foundation of ChinaProject(2006BAJ02A05) supported by the National Key Technology R&D Program,ChinaProject(08DZ1203600) supported by the Shanghai Municipal Sciences and Technology Committee,China
文摘Based on the thermal and velocity layer's theory,the experimental setup was established on large space atrium under nozzle outlet. A series of winter experiments were accomplished and the following conclusions could be drawn. At the sunny day of winter in Shanghai,the thermal and velocity layer are similar. The height of the both layer is 10-30 mm,and the temperature gratitude is 5-10 ℃ /m. Decreasing the angle of the nozzle outlet can increase the layer height dramatically. The maximum temperature difference of the occupant zone has relation with the angle of the nozzle outlet. The less the angle of the nozzle outlet is set,the greater the temperature difference is. The occupant temperature differences at these angles of the nozzle outlet are 5.1-4.4 ℃. The velocity of the wind is 0.02 and 0.17 m/s and they can accord with design demand. So,it can decrease the temperature gratitude by about 30% and it can save 10%-15% energy consumption.
基金Project(51171011) supported by the National Natural Science Foundation of China
文摘The stress corrosion crack （SCC） susceptibility of ultra-high strength steel AerMet 100 was investigated by slow strain rate technique （SSRT）, tensile with polarization and surface analysis technique. The curves of tf^Cl/tf^W -strain rate are divided into three regions： stress-dominated region, SCC-dominated region, and corrosion-dominated region, so as the curves of εf^Cl/εf^W - strain rate and tm/tf-strain rate. The results of tensile tests with polarization show that the main SCC mechanism of AerMet 100 is anodic dissolution, which controls the corrosion process. The three regions have been discussed according to the relationship between the rate of slip-step formation and the rate of dissolution. Fracture appearances in different environments were analyzed by scanning electron microscopy （SEM）. SCC fracture appears as a mixture of intergranular and dimples, while it is totally dimples in the inert environment. The εf becomes the parameter to predict tf because the relationship between εf^Cl/εf^W and tf^Cl/tf^w is a straight line for AerMet 100.
基金Project(51171011)supported by the National Science Foundation of China
文摘The effects of chloride,sulfate and carbonate anions on stress corrosion behaviors of ultra-high strength steel 23Co14Ni12Cr3Mo were studied by stress corrosion cracking(SCC)test method using double cantilever beam(DCB)specimens.The SCC morphology was observed by using scanning electron microscopy(SEM)and the composition of corrosion products was analyzed by using energy dispersive spectrometer(EDS).The results show that the crack propagates to bifurcation in NaCl and Na2SO4 solution,while the crack in Na2CO3 solution propagates along the load direction.The SCC rate in NaCl solution is the highest,while lower in Na2SO4 solution and little in Na2CO3 solution.From the SEM morphologies,quasi-cleavage fracture was observed in NaCl and Na2SO4 solutions,but intergranular features in Na2CO3 solution.The mechanism of anion effect on SCC of steel 23Co14Ni12Cr3Mo was studied by using full immersion test and electrochemical measurements.
基金Supported by the National Natural Science Foundation of China(50778064)Hunan Natural Science Foundation(07jj6088)
文摘In this study a 10-storied residential building model was employed to clarify the ventilation characteristics of the atrium and the rooms,which were effected by the different forms of lateral openings.The experiment was conducted under the combined effect of wind force and thermal buoyancy,and the similarity requirements were satisfied.The results have shown that the different forms of lateral openings cause the different ventilation effect of the building,and also have some certain regularity.The conclusions provide a theoretical foundation for how to use the ventilation of atrium better in high-rise residential building.
文摘Five thyreostats(TSs),namely tapazole,thiouracil,methylthiouracil,propylthiouracil,and phenylthiouracil,were determined in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)in positive electrospray ionization mode.Extraction and clean-up were achieved using a ChemElut cartridge with tert-butyl methyl ether,without a derivatization step.Separation was achieved on an Acquity UPLC SS T3 column.The mobile phase was acetonitrile and water containing 0.2%(v/v)formic acid.The mass spectrometer was operated in multiple reaction monitoring mode.Urine samples were spiked with TS solution at levels corresponding to 5,10,15,and 20μg/L.The accuracy(internal standard corrected)ranged from 92%to 107%,with a repeatability precision(relative standard deviation,RSD)less than 15%for all five analytes.The RSDs within-laboratory reproducibility was less than 26%.The decision limits(CCα)and detection capabilities(CCβ)were obtained from a calibration curve and were in the ranges of 3.1-6.1μg/L and 4.0-7.4μg/L,respectively.The CCαand CCβvalues were below the recommended concentration,which was set at 10μg/L.The results show that the described method is suitable for the direct detection of TSs in bovine urine.This method can also be used to determine TSs in porcine urine.
文摘Nano-Scale mapping of minerals and organic compounds give unprecedented high resolution information on the origin and nature of substances,and provide new insight on their correlative distribution and interaction,thus present a powerful tool to study the progressive changes of geological samples,and may even be applied to study extraterrestrial samples in search of life.One example we present here explore the use of elemental microprobe,X-Ray Photon Spectroscopy(XPS),and synchrotron-based Scanning Transmission X-ray Microscopy(STXM) coupled with Near Edge X-ray Absorption Fine Structure(NEXAFS) Spectroscopy to investigate the surface properties and stability of micron-size organic carbonaceous particles from Central Amazon,Brazil,specifically focusing on black carbon in Kaolinitic Oxisol originated from anthropogenic processes,and their interaction with cations.
文摘右心房结构和功能在维持心血管系统稳态中扮演关键角色,其形态重构及功能异常与多种心血管疾病进程紧密相连。近年来,随着心脏磁共振(cardiac magnetic resonance,CMR)技术的快速发展,其在无创评估心脏解剖、功能及心肌组织病理特征方面展现出独特优势,为右心房功能的精确评价提供了新的视角和方法。本文重点阐述CMR评估右心房功能的常用参数并深入探讨其在多种心血管疾病中的临床应用,指出当前CMR在右心房功能评估领域的研究不足和挑战,指明未来研究方向。本文旨在提高对CMR评估右心房功能的全面认识,促进其在心血管疾病诊疗中的广泛应用,为疾病的早期诊断、病情评估及预后判断提供参考。
文摘心脏分割算法提供精准把握心脏结构的信息,辅助医生进行诊断、制定治疗计划以及进行手术前的评估工作,提高临床治疗的效果并减轻并发症。然而,心脏分割在应用中存在诸多问题。手动分割方法不仅耗时费力,并且具有很强的主观意识。全监督的心脏分割方法虽已取得一定成果,但标注数据的依赖性过高。现有的半监督分割方法在处理复杂的心脏结构和病理变化时表现仍不够理想,难以在实际临床环境中稳定应用。为解决这一问题,提出了心脏磁共振成像(MRI)分割方法,结合Linformer and Performer merge V-Net(LPV-Net)和3D Enhanced Discriminator with Attention(3D-EDA)技术,实现了全局-局部信息的有效整合。LPV-Net模块由LinPerBlock和改进的V-Net联袂打造,旨在规范模型训练过程、实现全局与局部信息的有机整合,有效提高分割效果的准确性与鲁棒性。同时引入新鉴别器3D-EDA规范未标记数据,并加入关键模块CARE-Layer,集成自定义注意力模块以增强对特征重要信息的捕捉能力,辅助网络可提高主网络分割指标性能。在左心房数据集上进行综合实验,并将所提方法与MC-Net,V-Net等其他先进的半监督方法进行比较,发现该方法在基准数据集上的表现尤为优异。特别是在使用有限标签数据进行训练时,该方法仍然展示出卓越的性能;当仅使用10%和20%的标记数据进行训练时,该方法的Dice系数分别达到88.50%和90.39%。
文摘目的:探讨不同强度耐力运动对大鼠心房Ⅰ型胶原蛋白(Col-I)和Ⅲ型胶原蛋白(Col-III)的影响,并研究结缔组织生长因子(CTGF)的表达变化,为探究运动性心房纤颤的发生机制提供依据。方法:24只健康雄性SD大鼠随机分为安静组、中强度组和大强度组,每组8只。进行16周的运动训练,每周训练5天,每天1小时。16周末处死大鼠摘取心脏后分离出右心房,应用RT-PCR、免疫荧光化学和Western Blot技术测定Col-I、Col-III和CTGF基因与蛋白的表达。结果:与安静组相比,大强度组Col-I m RNA和蛋白的表达显著升高(P<0.05和P<0.01);Col-III m RNA增加但无显著性,蛋白表达显著性升高(P<0.01);Col-I/Col-III蛋白表达的比值显著升高(P<0.01);CTGF m RNA和蛋白的表达均显著升高(P<0.05)。与安静组相比,中强度组Col-I m RNA和蛋白的表达增加,但无统计学差异;Col-III m RNA表达显著性降低(P<0.01),蛋白表达无显著性变化;Col-I/Col-III蛋白表达比值增高,但无显著性;CTGF m RNA表达增高而蛋白表达降低,但均无显著性。结论:长期大强度运动可导致大鼠心房Col-I和Col-III显著增加、Col-I/Col-III比例发生失衡,可能与长期大强度运动诱导大鼠心房CTGF的表达增加有关,构成了运动性心房纤颤发生的重要病理机制之一。
