The bonding interface of 7B52 Al alloy laminated composite （ALC） fabricated by hot rolling was investigated using optical microscopy （OM）, transmission electron microscopy （TEM）, scanning electron microscopy （...The bonding interface of 7B52 Al alloy laminated composite （ALC） fabricated by hot rolling was investigated using optical microscopy （OM）, transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, ultrasonic flaw detection （UFD）, and bonding strength tests. The results show that metallurgical bonding is achieved at the interface after composite rolling. The TEM analysis and tensile tests indicate that the 7B52 ALC plate combines high strength of the hard individual layer and good toughness of the soft individual layer. However, UFD technology and SEM analysis prove that the defects （thick oxide films, acid washed residues, air, oil and coarse particles） existing in the bonding interface are harmful to the bonding strength. To sum up, the composite roiling process is suitable for 7B52 ALC plate, and the content and size of the defects should be controlled strictly. Advanced surface treatment of each individual layer would be beneficial to further improve the bonding quality.展开更多
The eukaryotic genome is folded into higher-order conformation accompanied with constrained dynamics for coordinated genome functions.However,the molecular machinery underlying these hierarchically organized three-dim...The eukaryotic genome is folded into higher-order conformation accompanied with constrained dynamics for coordinated genome functions.However,the molecular machinery underlying these hierarchically organized three-dimensional(3D)chromatin architecture and dynamics remains poorly understood.Here by combining imaging and sequencing,we studied the role of lamin B1 in chromatin architecture and dynamics.We found that lamin B1 depletion leads to detachment of lamina-associated domains(LADs)from the nuclear periphery accompanied with global chromatin redistribution and decompaction.Consequently,the interchromosomal as well as inter-compartment interactions are increased,but the structure of topologically associating domains(TADs)is not affected.Using live-cell genomic loci tracking,we further proved that depletion of lamin B1 leads to increased chromatin dynamics,owing to chromatin decompaction and redistribution toward nucleoplasm.Taken together,our data suggest that lamin B1 and chromatin interactions at the nuclear periphery promote LAD maintenance,chromatin compaction,genomic compartmentalization into chromosome territories and A/B compartments and confine chromatin dynamics,supporting their crucial roles in chromatin higher-order structure and chromatin dynamics.展开更多
为提高结构用竹篾层积材(LBSL)的强度性能,以间苯二酚为改性剂合成了系列热固型苯酚-间苯二酚-甲醛(PRF)树脂,用于制备毛竹LBSL。以热固型PRF树脂中间苯二酚质量百分含量、甲醛与苯酚的摩尔比及竹帘浸胶时树脂固体含量为影响因子,进行了...为提高结构用竹篾层积材(LBSL)的强度性能,以间苯二酚为改性剂合成了系列热固型苯酚-间苯二酚-甲醛(PRF)树脂,用于制备毛竹LBSL。以热固型PRF树脂中间苯二酚质量百分含量、甲醛与苯酚的摩尔比及竹帘浸胶时树脂固体含量为影响因子,进行了3因子3水平的正交试验,利用方差分析和显著性检验研究了因子对所制备毛竹LBSL物理力学性能的影响。结果表明:树脂中间苯二酚质量百分含量对制备LBSL的弹性模量(MOE)及24 h吸水厚度膨胀率(24 h TS)影响非常显著;树脂中甲醛与苯酚摩尔比的变化对LBSL浸渍剥离率(DR)、24 h TS和游离醛含量(FF)影响非常显著;竹帘浸胶时树脂的固体含量对LBSL的24 h TS影响非常显著,对LBSL的静曲强度(MOR)影响显著。以热固型PRF树脂制备毛竹LBSL的优化因子水平为:间苯二酚质量百分含量1.5%、甲醛与苯酚摩尔比2.0∶1、竹帘浸胶时树脂固体含量为25.0%。展开更多
文中采用Si_3N_4为绝缘壳体,Si_3N_4-B_4C和Si_3N_4-SiC为正、负极,设计制备层压式整体陶瓷热电偶传感器,并进行组织结构分析与性能测试。结果表明:热电偶各层之间以及电极复合材料中第二相与基体之间结合紧密;正、负电极复合材料呈现...文中采用Si_3N_4为绝缘壳体,Si_3N_4-B_4C和Si_3N_4-SiC为正、负极,设计制备层压式整体陶瓷热电偶传感器,并进行组织结构分析与性能测试。结果表明:热电偶各层之间以及电极复合材料中第二相与基体之间结合紧密;正、负电极复合材料呈现典型渗流导电行为;绝缘壳体与正、负电极之间具有良好的热适配性;热电偶在1 600℃时输出热电势与塞贝克系数达到242 m V和154.31μV/℃,在1 200℃保温时热电势偏差为±0.28%,表现出良好的测量精度、灵敏度和稳定度。展开更多
基金Project(51312JQ08)supported by the Pre-Research Foundation of China General Equipment DepartmentProject(NBPJ2013-4)supported by the Postdoctoral Science Foundation of Ningbo Branch of China Academy of Ordnance Science+1 种基金Project(bsh1402073)supported by the Postdoctoral Science Foundation of Zhejiang Province,ChinaProject(2014A610051)supported by the Ningbo Natural Science Foundation of China
文摘The bonding interface of 7B52 Al alloy laminated composite （ALC） fabricated by hot rolling was investigated using optical microscopy （OM）, transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, ultrasonic flaw detection （UFD）, and bonding strength tests. The results show that metallurgical bonding is achieved at the interface after composite rolling. The TEM analysis and tensile tests indicate that the 7B52 ALC plate combines high strength of the hard individual layer and good toughness of the soft individual layer. However, UFD technology and SEM analysis prove that the defects （thick oxide films, acid washed residues, air, oil and coarse particles） existing in the bonding interface are harmful to the bonding strength. To sum up, the composite roiling process is suitable for 7B52 ALC plate, and the content and size of the defects should be controlled strictly. Advanced surface treatment of each individual layer would be beneficial to further improve the bonding quality.
基金This work is supported by grants from National Key R&D Program of China,No.2017YFA0505302the National Science Foundation of China 21573013,21825401 for Y.S.+1 种基金Chinese National Key Projects of Research and Development,No.2016YFA0100103,Peking-Tsinghua Center for Life SciencesNational Natural Science Foundation of China Key Research Grant 31871266 for C.L。
文摘The eukaryotic genome is folded into higher-order conformation accompanied with constrained dynamics for coordinated genome functions.However,the molecular machinery underlying these hierarchically organized three-dimensional(3D)chromatin architecture and dynamics remains poorly understood.Here by combining imaging and sequencing,we studied the role of lamin B1 in chromatin architecture and dynamics.We found that lamin B1 depletion leads to detachment of lamina-associated domains(LADs)from the nuclear periphery accompanied with global chromatin redistribution and decompaction.Consequently,the interchromosomal as well as inter-compartment interactions are increased,but the structure of topologically associating domains(TADs)is not affected.Using live-cell genomic loci tracking,we further proved that depletion of lamin B1 leads to increased chromatin dynamics,owing to chromatin decompaction and redistribution toward nucleoplasm.Taken together,our data suggest that lamin B1 and chromatin interactions at the nuclear periphery promote LAD maintenance,chromatin compaction,genomic compartmentalization into chromosome territories and A/B compartments and confine chromatin dynamics,supporting their crucial roles in chromatin higher-order structure and chromatin dynamics.
文摘为提高结构用竹篾层积材(LBSL)的强度性能,以间苯二酚为改性剂合成了系列热固型苯酚-间苯二酚-甲醛(PRF)树脂,用于制备毛竹LBSL。以热固型PRF树脂中间苯二酚质量百分含量、甲醛与苯酚的摩尔比及竹帘浸胶时树脂固体含量为影响因子,进行了3因子3水平的正交试验,利用方差分析和显著性检验研究了因子对所制备毛竹LBSL物理力学性能的影响。结果表明:树脂中间苯二酚质量百分含量对制备LBSL的弹性模量(MOE)及24 h吸水厚度膨胀率(24 h TS)影响非常显著;树脂中甲醛与苯酚摩尔比的变化对LBSL浸渍剥离率(DR)、24 h TS和游离醛含量(FF)影响非常显著;竹帘浸胶时树脂的固体含量对LBSL的24 h TS影响非常显著,对LBSL的静曲强度(MOR)影响显著。以热固型PRF树脂制备毛竹LBSL的优化因子水平为:间苯二酚质量百分含量1.5%、甲醛与苯酚摩尔比2.0∶1、竹帘浸胶时树脂固体含量为25.0%。
文摘文中采用Si_3N_4为绝缘壳体,Si_3N_4-B_4C和Si_3N_4-SiC为正、负极,设计制备层压式整体陶瓷热电偶传感器,并进行组织结构分析与性能测试。结果表明:热电偶各层之间以及电极复合材料中第二相与基体之间结合紧密;正、负电极复合材料呈现典型渗流导电行为;绝缘壳体与正、负电极之间具有良好的热适配性;热电偶在1 600℃时输出热电势与塞贝克系数达到242 m V和154.31μV/℃,在1 200℃保温时热电势偏差为±0.28%,表现出良好的测量精度、灵敏度和稳定度。
