海上浮式生产装置(floating production unit,FPU)上部生产模块结构中包含着大量的非管节点,而此类节点在其服役期内易发生疲劳失效。相较于一般管节点,非管节点结构型式更为复杂,其疲劳评估更为困难,通常无法利用海工结构设计软件进行...海上浮式生产装置(floating production unit,FPU)上部生产模块结构中包含着大量的非管节点,而此类节点在其服役期内易发生疲劳失效。相较于一般管节点,非管节点结构型式更为复杂,其疲劳评估更为困难,通常无法利用海工结构设计软件进行直接计算分析。为了实现非管节点疲劳寿命快速计算,该文采用S-N曲线法与整体结构分析和局部有限元分析相结合的方法,对非管节点的疲劳进行了研究,并形成了一套FPU上部生产模块非管节点疲劳预测方法。基于FPU上部三甘醇(triethylene glycol,TEG)处理模块设计实例,采用上述方法对其疲劳寿命进行评估,验证了该计算方法的适用性。结果显示,在考虑安全系数的情况下,TEG模块非管节点的最小疲劳寿命为20.11年,满足设计规范要求。该模块通过了美国船级社(American Bureau of Shipping,ABS)审查,完成陆地建造和交付,并成功应用于印尼马杜拉海域,证明了该非管节点疲劳预测方法的可靠性,相关研究结论可为类似非管节点结构的疲劳分析提供借鉴。展开更多
Maize(Zea mays),which is a vital source of food,feed,and energy feedstock globally,has significant potential for higher yields.However,environmental stress conditions,including drought and salt stress,severely restric...Maize(Zea mays),which is a vital source of food,feed,and energy feedstock globally,has significant potential for higher yields.However,environmental stress conditions,including drought and salt stress,severely restrict maize plant growth and development,leading to great yield losses.Leucine-rich repeat receptor-like kinases(LRR-RLKs)function in biotic and abiotic stress responses in the model plant Arabidopsis(Arabidopsis thaliana),but their roles in abiotic stress responses in maize are not entirely understood.In this study,we determine that the LRR-RLK ZmMIK2,a homolog of the Arabidopsis LRR-RK MALE DISCOVERER 1(MDIS1)-INTERACTING RECEPTOR LIKE KINASE 2(MIK2),functions in resistance to both drought and salt stress in maize.Zmmik2 plants exhibit enhanced resistance to both stresses,whereas overexpressing ZmMIK2 confers the opposite phenotypes.Furthermore,we identify C2-DOMAIN-CONTAINING PROTEIN 1(ZmC2DP1),which interacts with the intracellular region of ZmMIK2.Notably,that region of ZmMIK2 mediates the phosphorylation of ZmC2DP1,likely by increasing its stability.Both ZmMIK2 and ZmC2DP1 are mainly expressed in roots.As with ZmMIK2,knockout of ZmC2DP1 enhances resistance to both drought and salt stress.We conclude that ZmMIK2-ZmC2DP1 acts as a negative regulatory module in maize drought-and salt-stress responses.展开更多
陶瓷产品生产过程中普遍存在中低温烟气余热过剩问题,这些余热的浪费严重制约了陶瓷低碳节能化生产和可持续发展。为此,提出利用窑炉余热驱动氯化铵干燥的方案以提高陶瓷生产过程能效,通过构建含用户自定义函数UDF的氯化铵干燥动力学模...陶瓷产品生产过程中普遍存在中低温烟气余热过剩问题,这些余热的浪费严重制约了陶瓷低碳节能化生产和可持续发展。为此,提出利用窑炉余热驱动氯化铵干燥的方案以提高陶瓷生产过程能效,通过构建含用户自定义函数UDF的氯化铵干燥动力学模型,重点研究分析氯化铵干燥特性及其干燥过程水分迁移规律。研究结果表明:Two term model模型可以准确预测氯化铵干燥过程,氯化铵干燥可分为加速干燥阶段和降速干燥阶段,不同时刻沿x方向的水分迁移速率存在较大的差异,在干燥初期,氯化铵制品中水分迁移速率WMR从边缘至中心先快速增大后缓慢减小,且有微量水分聚集现象,而后中心区域WMR逐渐升高。随着干燥的继续,WMR从边缘至中心保持递增变化规律,整体WMR呈现下降趋势。z方向的WMR变化规律与x方向基本相同,但其WMR峰值由中心转移至偏上方位置处。展开更多
Dear Editor,A 34-year-old male presented to West China Hospital due to a 6-year history of infertility.The patient had experienced recurrent respiratory tract infections since early childhood and had been previously d...Dear Editor,A 34-year-old male presented to West China Hospital due to a 6-year history of infertility.The patient had experienced recurrent respiratory tract infections since early childhood and had been previously diagnosed with primary ciliary dyskinesia(PCD)at an external institution.CT imaging confirmed situs inversus totalis,establishing a diagnosis of Kartagener syndrome[1].展开更多
Hexagonal boron nitride(h-BN)has emerged as a promising two-dimensional material for quantum and optoelectronic applications,with its unique ability to host engineered defects enabling single-photon emission and spin ...Hexagonal boron nitride(h-BN)has emerged as a promising two-dimensional material for quantum and optoelectronic applications,with its unique ability to host engineered defects enabling single-photon emission and spin manipulation.This study investigates defect formation in h-BN using focused helium ion beam(He^(+)FIB)irradiation and post-annealing treatments.We demonstrate that helium ion irradiation at doses up to 2×10^(9) ions/μm^(2) does not induce phase transitions or amorphization.Spectroscopic analyses,including differential reflectance spectroscopy(DRS),photoluminescence(PL),and Raman spectroscopy,reveal substantial defect formation and structural modifications.Notably,the irradiation induces a softening of in-plane and interlayer phonon modes,characterized by frequency redshifts of 10.5 cm^(-1) and 3.2 cm^(-1),respectively.While high-temperature thermal annealing mitigates lattice defects and facilitates single-photon emission,the E_(2g) peak width remains 38%broader and the shear mode peak width is 60%broader compared to pre-annealing conditions in the Raman spectra,indicating residual structural degradation.These findings provide insights into defect engineering mechanisms in h-BN,offering guidance for optimizing processing conditions and advancing quantum and optoelectronic device technologies.展开更多
文摘海上浮式生产装置(floating production unit,FPU)上部生产模块结构中包含着大量的非管节点,而此类节点在其服役期内易发生疲劳失效。相较于一般管节点,非管节点结构型式更为复杂,其疲劳评估更为困难,通常无法利用海工结构设计软件进行直接计算分析。为了实现非管节点疲劳寿命快速计算,该文采用S-N曲线法与整体结构分析和局部有限元分析相结合的方法,对非管节点的疲劳进行了研究,并形成了一套FPU上部生产模块非管节点疲劳预测方法。基于FPU上部三甘醇(triethylene glycol,TEG)处理模块设计实例,采用上述方法对其疲劳寿命进行评估,验证了该计算方法的适用性。结果显示,在考虑安全系数的情况下,TEG模块非管节点的最小疲劳寿命为20.11年,满足设计规范要求。该模块通过了美国船级社(American Bureau of Shipping,ABS)审查,完成陆地建造和交付,并成功应用于印尼马杜拉海域,证明了该非管节点疲劳预测方法的可靠性,相关研究结论可为类似非管节点结构的疲劳分析提供借鉴。
基金supported by the National Key Research and Development Program of China(2021YFD1200703 and 2022YFF1001602)the National Science Foundation of China(32272024 and 32171940)+2 种基金the Pinduoduo-China Agricultural University Research Fund(PC2023B01001)the Chinese Universities Scientific Fund(2022TC142)the 2115 Talent Development Program of China Agricultural University。
文摘Maize(Zea mays),which is a vital source of food,feed,and energy feedstock globally,has significant potential for higher yields.However,environmental stress conditions,including drought and salt stress,severely restrict maize plant growth and development,leading to great yield losses.Leucine-rich repeat receptor-like kinases(LRR-RLKs)function in biotic and abiotic stress responses in the model plant Arabidopsis(Arabidopsis thaliana),but their roles in abiotic stress responses in maize are not entirely understood.In this study,we determine that the LRR-RLK ZmMIK2,a homolog of the Arabidopsis LRR-RK MALE DISCOVERER 1(MDIS1)-INTERACTING RECEPTOR LIKE KINASE 2(MIK2),functions in resistance to both drought and salt stress in maize.Zmmik2 plants exhibit enhanced resistance to both stresses,whereas overexpressing ZmMIK2 confers the opposite phenotypes.Furthermore,we identify C2-DOMAIN-CONTAINING PROTEIN 1(ZmC2DP1),which interacts with the intracellular region of ZmMIK2.Notably,that region of ZmMIK2 mediates the phosphorylation of ZmC2DP1,likely by increasing its stability.Both ZmMIK2 and ZmC2DP1 are mainly expressed in roots.As with ZmMIK2,knockout of ZmC2DP1 enhances resistance to both drought and salt stress.We conclude that ZmMIK2-ZmC2DP1 acts as a negative regulatory module in maize drought-and salt-stress responses.
文摘陶瓷产品生产过程中普遍存在中低温烟气余热过剩问题,这些余热的浪费严重制约了陶瓷低碳节能化生产和可持续发展。为此,提出利用窑炉余热驱动氯化铵干燥的方案以提高陶瓷生产过程能效,通过构建含用户自定义函数UDF的氯化铵干燥动力学模型,重点研究分析氯化铵干燥特性及其干燥过程水分迁移规律。研究结果表明:Two term model模型可以准确预测氯化铵干燥过程,氯化铵干燥可分为加速干燥阶段和降速干燥阶段,不同时刻沿x方向的水分迁移速率存在较大的差异,在干燥初期,氯化铵制品中水分迁移速率WMR从边缘至中心先快速增大后缓慢减小,且有微量水分聚集现象,而后中心区域WMR逐渐升高。随着干燥的继续,WMR从边缘至中心保持递增变化规律,整体WMR呈现下降趋势。z方向的WMR变化规律与x方向基本相同,但其WMR峰值由中心转移至偏上方位置处。
基金supported by the Natural Science Foundation of China(824B2017 to Xiong Y)Sichuan Science and Technology Program(2025YFHZ0212 to Qin F).
文摘Dear Editor,A 34-year-old male presented to West China Hospital due to a 6-year history of infertility.The patient had experienced recurrent respiratory tract infections since early childhood and had been previously diagnosed with primary ciliary dyskinesia(PCD)at an external institution.CT imaging confirmed situs inversus totalis,establishing a diagnosis of Kartagener syndrome[1].
基金supported by the National Natural Science Foundation of China(Grant Nos.11727902,12074372,12174385,12334014,and 12304112).
文摘Hexagonal boron nitride(h-BN)has emerged as a promising two-dimensional material for quantum and optoelectronic applications,with its unique ability to host engineered defects enabling single-photon emission and spin manipulation.This study investigates defect formation in h-BN using focused helium ion beam(He^(+)FIB)irradiation and post-annealing treatments.We demonstrate that helium ion irradiation at doses up to 2×10^(9) ions/μm^(2) does not induce phase transitions or amorphization.Spectroscopic analyses,including differential reflectance spectroscopy(DRS),photoluminescence(PL),and Raman spectroscopy,reveal substantial defect formation and structural modifications.Notably,the irradiation induces a softening of in-plane and interlayer phonon modes,characterized by frequency redshifts of 10.5 cm^(-1) and 3.2 cm^(-1),respectively.While high-temperature thermal annealing mitigates lattice defects and facilitates single-photon emission,the E_(2g) peak width remains 38%broader and the shear mode peak width is 60%broader compared to pre-annealing conditions in the Raman spectra,indicating residual structural degradation.These findings provide insights into defect engineering mechanisms in h-BN,offering guidance for optimizing processing conditions and advancing quantum and optoelectronic device technologies.
