通过激光溅射Pb产生的Pb等离子体与SF_(6)/Ar反应制备了PbF自由基,利用激光诱导荧光光谱测量了PbF分子A^(2)∑^(+)—X^(2)∏_(1/2)跃迁光谱,并精确测得了其A态振动能级v=0和v=1的分子常数T_(0)、B、D、γ和p.此外,还精确测量了PbF分子A^...通过激光溅射Pb产生的Pb等离子体与SF_(6)/Ar反应制备了PbF自由基,利用激光诱导荧光光谱测量了PbF分子A^(2)∑^(+)—X^(2)∏_(1/2)跃迁光谱,并精确测得了其A态振动能级v=0和v=1的分子常数T_(0)、B、D、γ和p.此外,还精确测量了PbF分子A^(2)∑^(+)态v=0振动态的荧光寿命.采用Morse势和RKR(Rydberg-Klein-Rees inversion)/LEVEL方法计算了A^(2)∑^(+)—X^(2)∏_(1/2)跃迁的Franck-Condon因子.计算结果表明,PbF分子不适合进行激光冷却的研究.这不仅丰富了对PbF分子光谱的深入理解,而且为进一步精密测量电子电偶极矩(electronic electric dipole moment,eEDM)提供了重要参考.展开更多
通过对激光粉末床熔化(laser powder bed fusion,L-PBF)成形FGH4096M镍基粉末高温合金进行不同温度的退火处理,采用SEM、EBSD等分析了合金的微观组织结构,并对其进行了拉伸测试,进而研究退火工艺对激光粉末床熔化成形FGH4096M镍基粉末...通过对激光粉末床熔化(laser powder bed fusion,L-PBF)成形FGH4096M镍基粉末高温合金进行不同温度的退火处理,采用SEM、EBSD等分析了合金的微观组织结构,并对其进行了拉伸测试,进而研究退火工艺对激光粉末床熔化成形FGH4096M镍基粉末高温合金中显微组织的演变及力学性能的影响。结果表明:随着退火温度的升高,成形态合金中胞状晶组织和柱状晶组织出现了消失的趋势,当退火温度为900℃时,开始发现有大量γ′相析出;其硬度值先升高后降低,抗拉强度和屈服强度均呈现先上升后降低趋势,但其断后延伸率在逐渐降低。通过对晶粒取向差分布分析,可知退火能够消除部分残余应力。这一研究成果为激光粉末床熔化成形镍基粉末高温合金性能的提升提供了有效的数据支撑。展开更多
[Objective] This study aimed to investigate the polymorphism of PBF en- coding genes from common wheat Chinese Spring （Triticum aestivum L.）. [Method] Using common wheat Chinese Spring as the experimental material, ...[Objective] This study aimed to investigate the polymorphism of PBF en- coding genes from common wheat Chinese Spring （Triticum aestivum L.）. [Method] Using common wheat Chinese Spring as the experimental material, gene-specific primers were designed and applied to amplify the genomic DNA of Chinese Spring. PCR products were isolated, purified and ligated into the cloning vector. Positive clones were randomly selected for sequencing. A series of softwares including DNAMAN, Signalp, PSIPRED, Nuc_PLoc and MEGA were employed for sequence assembly and alignment, signal peptide prediction, primary and secondary structure prediction, as well as analyses of subcellular location and phylogenetic relationships between the PBF family members in Poaceae. [Result] Twenty-five target sequences were obtained from the genome of hexaploid common wheat Chinese Spring, which were classified into three clusters based on the sequence similarity. SNPs exist at two loci of the subunit, resulting in the change of encoded amino acid residues and affecting the secondary structure of final product encoded. [Conclusion] PBF encoding sequences are extremely conservative in Chinese Spring with certain variations. This study provides theoretical reference to evaluate the expression efficiency of wheat storage proteins.展开更多
文摘通过激光溅射Pb产生的Pb等离子体与SF_(6)/Ar反应制备了PbF自由基,利用激光诱导荧光光谱测量了PbF分子A^(2)∑^(+)—X^(2)∏_(1/2)跃迁光谱,并精确测得了其A态振动能级v=0和v=1的分子常数T_(0)、B、D、γ和p.此外,还精确测量了PbF分子A^(2)∑^(+)态v=0振动态的荧光寿命.采用Morse势和RKR(Rydberg-Klein-Rees inversion)/LEVEL方法计算了A^(2)∑^(+)—X^(2)∏_(1/2)跃迁的Franck-Condon因子.计算结果表明,PbF分子不适合进行激光冷却的研究.这不仅丰富了对PbF分子光谱的深入理解,而且为进一步精密测量电子电偶极矩(electronic electric dipole moment,eEDM)提供了重要参考.
文摘通过对激光粉末床熔化(laser powder bed fusion,L-PBF)成形FGH4096M镍基粉末高温合金进行不同温度的退火处理,采用SEM、EBSD等分析了合金的微观组织结构,并对其进行了拉伸测试,进而研究退火工艺对激光粉末床熔化成形FGH4096M镍基粉末高温合金中显微组织的演变及力学性能的影响。结果表明:随着退火温度的升高,成形态合金中胞状晶组织和柱状晶组织出现了消失的趋势,当退火温度为900℃时,开始发现有大量γ′相析出;其硬度值先升高后降低,抗拉强度和屈服强度均呈现先上升后降低趋势,但其断后延伸率在逐渐降低。通过对晶粒取向差分布分析,可知退火能够消除部分残余应力。这一研究成果为激光粉末床熔化成形镍基粉末高温合金性能的提升提供了有效的数据支撑。
基金Supported by National Natural Science Foundation of China(30900896)Special Fund for the Construction of Modern Agricultural Technology System(NYCYTX-001)Cyrus Tang Breeding Fund(A212020912)~~
文摘[Objective] This study aimed to investigate the polymorphism of PBF en- coding genes from common wheat Chinese Spring （Triticum aestivum L.）. [Method] Using common wheat Chinese Spring as the experimental material, gene-specific primers were designed and applied to amplify the genomic DNA of Chinese Spring. PCR products were isolated, purified and ligated into the cloning vector. Positive clones were randomly selected for sequencing. A series of softwares including DNAMAN, Signalp, PSIPRED, Nuc_PLoc and MEGA were employed for sequence assembly and alignment, signal peptide prediction, primary and secondary structure prediction, as well as analyses of subcellular location and phylogenetic relationships between the PBF family members in Poaceae. [Result] Twenty-five target sequences were obtained from the genome of hexaploid common wheat Chinese Spring, which were classified into three clusters based on the sequence similarity. SNPs exist at two loci of the subunit, resulting in the change of encoded amino acid residues and affecting the secondary structure of final product encoded. [Conclusion] PBF encoding sequences are extremely conservative in Chinese Spring with certain variations. This study provides theoretical reference to evaluate the expression efficiency of wheat storage proteins.
