Influence of minor boron on the microstructures of a second generation Nibased single crystal superalloy

Boron is added into single crystal superalloys as a micro-alloying element to strengthen low angle grain boundaries.However,systematic investigations on the effect of boron on microstructures of single crystal superalloys are limitedly reported.The effect of boron on as-cast and heat-treated microstructures was investigated in two experimental Ni-based single crystal superalloys containing 3 wt% Re.The current results indicated that the volume fraction of(γ+γ′)eutectic and M_3B_2 borides was evidently increased,while the number of micropores was evidently decreased with the addition of 0.02 wt% boron.The(γ+γ′)eutectic could not be dissolved completely due to the lower incipient melting temperature caused by the formation of M_3B_2 borides.Meanwhile,the M_3B_2 borides were found to be enriched with indispensable strengthening elements Cr,Mo,W and Re,and this may lower the strengthening effect and cause stress concentration during high temperature creep.     

肖邦《g 小调第一叙事曲》奏鸣曲式及其音乐结构特征

《g 小调第一叙事曲》是肖邦四部叙事钢琴曲中的代表作，也是肖邦的钢琴创作走向成熟的重要表现。在《g 小调第一叙事曲》的创作过程中，肖邦并没有沿用传统奏鸣曲式的创作方式，而是将变奏与奏鸣、回旋进行了高度融合，在曲式结构上创造了自由性特征，对后人研究叙事钢琴曲产生了重要影响。     

MGB probe assay for rapid detection of mtDNAl1778 mutation in the Chinese LHON patients by real-time PCR

Objective： Leber＇s hereditary optic neuropathy （LHON） is a maternally inherited degeneration of the optic nerve caused by point mutations of mitochondrial DNA （mtDNA）. Many unsolved questions regarding the penetrance and pathophysiological mechanism of LHON demand efficient and reliable mutation testing. This study aims to develop a minor groove binder （MGB） probe assay for rapid detection of mtDNA11778 mutation and heteroplasmy in Chinese LHON patients by real-time polymerase chain reaction （PCR）. Methods： Forty-eight patients suspected of having LHON and their maternal relatives underwent a molecular genetic evaluation, with 20 normal individuals as a control group at the same time. A real-time PCR involving two MGB probes was used to detect the mtDNA 1 1778 mutation and heteroplasmy. A linear standard curve was obtained by pUCmLHONG and pUCmLHONA clones. Results： All 48 LHON patients and their maternal relatives were positive for rntDNA11778 mutation in our assay, 27 heteroplasmic and 21 homoplasmic. Eighteen cases did not show an occurrence of the disease, while 9 developed the disease among the 27 heteroplasmic mutation cases. Eleven did not show an occurrence of the disease, while 10 cases developed the disease among 21 homoplasmic mutation cases. There was a significant difference in the incidence between the heteroplasmic and the homoplasmic mutation types. The time needed for running a real-time PCR assay was only 80 min. Conclusion： This real-time PCR assay is a rapid, reliable method for mtDNA mutation detection as well as heteroplasmy quantification. Detecting this ratio is very important for predicting phenotypic expression of unaffected carriers.     

钢琴上的《沂蒙山小调》--谈《刘庄钢琴变奏曲》及演奏

中国作品在探索民族音调方面走过了一条曲折的路，虽然积累了一些创作经验．但只是停留在对民间音调的采用上．《刘庄钢琴变奏曲》在利用钢琴表现民族音乐方面，找出了一条“民族化”与“世界化”相结合的道路．由此可见，民族音乐的发展要从“多元化”中去寻找锲机。     

隰县凤凰山上的悬塑绝唱

山西隰县小西天大雄宝殿彩塑是明末清初的反映佛教历史和极乐世界的大型塑像遗存。文章从题材和主题上分析了其佛教思想研究价值和观赏价值,重点从技术层面挖掘分析了其科学价值和制作工艺方面的价值。     

不中断交通下连续箱梁桥拼接缝浇筑方式分析

为了探究不中断交通条件下连续箱梁桥拼宽关键技术,本文依托机荷高速改扩建工程,通过现场桥梁的车桥耦合振动测试,得到某连续箱梁桥的最大振动频率为5.62 Hz,最大振动速度为18 mm?s-1。考虑现场车流量的随机性,以安全的原则共设置两种车辆振动环境（5 Hz,25 mm?s-1和10 Hz,50 mm?s-1）,并在实验室中测定了不同龄期抗扰动纤维增强混凝土（Fiber Reinforced Cementitious-composite material 50,FRCM50）的弹性模量和抗拉强度。结合现有的施工工艺和新型接缝材料的特点,提出微差浇筑施工工艺。然后,分别分析了采用一次浇筑、分段浇筑和微差浇筑施工工艺时拼宽连续箱梁的受力特点、接缝时变应力、交通组织模式以及经济性,结果表明微差浇筑工艺具有受力合理、施工机械少、经济性好等优点,可指导实际工程施工,具有良好的应用性。     

“二雅”及清华简《耆夜》所见宴飨诗酒意象研究

酒在《诗经》"二雅"及清华简《耆夜》的宴飨诗中扮演着重要角色,它作为一种媒介,沟通神人、君臣、宾主,是贯串宴飨礼的纽带。酒是宴飨礼的中介物,也是宴飨诗的关键意象,它是为礼乐文明服务的。酒是宗族血缘网络的纽带,也是祭祀祖先神灵的媒介。周人重德,在对酒的态度上重视酒德。周人饮酒是为礼乐文明服务的,德是礼的内化,酒德是周人对酒的态度的表现。周人不杜绝饮酒,但反对纵酒失德。从某种程度上说,宴飨诗是周人礼乐制度嬗变的镜子。《耆夜》展现了宴飨礼典尤其是赋诗的具体过程,反映了周公的"无逸"思想,弥足珍贵。     

浅析格里格的两首代表作品

文章通过对格里格生平的介绍和他两部代表作的分析。让大家对格里格这位杰出的挪威作曲家以及他浓郁的民族风格有一定的了解。     

未成年被告人判前社会调查制度的建构

在对未成年被告人判决宣告前,由专门机构或专门人员对未成年被告人犯罪行为的背景情况进行社会调查,并对其人身危险性和再犯可能性进行专业系统分析,以供法院参考,使判处的刑罚有利于未成年罪犯的改过自新及健康成长。从调查人员、调查机构、调查内容、调查程序和调查方式等各方面建构,完善未成年被告人判前社会调查制度,并应用于司法实践,努力实现对未成年罪犯的挽救教育和再社会化。