H型钢梁与矩形钢管柱平齐端板单向螺栓节点承载力性能

对H型钢梁与矩形钢管柱平齐式端板单向螺栓连接节点承载性能进行试验和理论分析研究.通过对3种不同形式的平齐式端板单向螺栓连接节点进行单调静力加载试验,获得了各试件的破坏模式和弯矩-转角曲线,讨论了螺栓破坏、端板破坏、柱壁破坏等3种破坏模式.基于试验现象提出了节点螺栓力理论分布模式,并给出了螺栓强度控制的节点抗弯承载力计算公式.通过将端板和钢梁腹板等效为T形件,得出了端板屈服控制的节点抗弯承载力计算公式.基于试验现象并利用屈服线理论提出了钢管柱壁的屈服线模型,运用虚功原理得出由柱壁强度控制的节点抗弯承载力计算公式.研究表明螺栓、端板、柱壁间的相对强弱关系直接影响节点的破坏模式,理论计算值与试验相比结果偏安全.给出了H型钢梁与矩形钢管柱平齐式端板单向螺栓连接节点的设计准则和建议.     

侗族村寨聚居空间演变特征分析——以贵州黎平高寅侗寨为例

以贵州省黔东南州黎平县九潮镇高寅侗寨为典型案例,从农户宅基地利用视角,对侗族村寨用地规模及其内部特征、空间演变过程及其形态特征进行研究.研究结果表明,1990年以来高寅侗寨宅基地扩张面积占总面积的比例达到70%以上,户均宅基地面积维持在170m2左右,高寅侗寨宅基地扩张具有加速蔓延趋势且新修房屋正逐步放弃传统木瓦结构,偏好砖混结构;农户宅基地的居住功能在不断加强,而生产功能(主要是圈舍养殖等)正逐步趋于弱化,内部结构正趋于简单化、集约化;近三十多年高寅侗寨用地存在着先沿"歌堂"内向"填充",后向"风雨桥"外向扩展的演变过程,体现了侗族村民依山傍水的建房理念.     

Finite size effect on the Raman frequency of phonons in nano-semiconductors

A comprehensive study on Raman spectroscopy with different excitation wavelengths, sample sizes, and sample shapes for optic phonons (OPs) and acoustic phonons (APs) in polar and non-polar nano-semiconductors has been performed. The study affirms that the finite size effect does not appear in the OPs of polar nano-semiconductors, while it exists in all other types of phonons. The absence of the FSE is confirmed to originate from the long-range Fr¨ohlich interaction and the breaking of translation symmetry. The result indicates that the Raman spectra of OPs cannot be used as a method to characterize the scale and crystalline property of polar nano-semiconductors.     

Driving Mechanism of Cotton Comber's Detaching Roller Based on Time-Sharing Unidirectional Drive

The high-speed reciprocating motion of a detaching roller limits the velocity of a cotton comber and affects the quality of comber slivers. The article has proposed a controllable time-sharing unidirectional hybrid drive mechanism after analyzing detaching roller＇s current numerical control drive method. The analysis focuses on the detaching roller motion required according to cotton comber＇s velocity and process. The double-servo motors of the mechanism consists of differential gear trains. The mechanism addresses the problem of increased servo motor power,and failure of promptly responded to the positive inversion process of mechanism driven by servo motors. A velocity calculation model of the detaching roller controllable drive mechanism will be generated by using superposition method and design of differential gear trains. The accuracy of the model will be verified using the test platform. This study has presented a reliable and practical high-speed drive mechanism and can be a reference to future studies on high-speed reciprocating motion drive.     

团体心理辅导促进学生心理健康的叙事研究——基于遵义市S中学的团体辅导实践

叙事研究方法可以真实灵活地呈现团体心理辅导的具体过程。通过对遵义市S中学团体心理辅导的叙事研究,具体展示了团体心理辅导的历程,同时对其进行了细致的"深描",进而对中学生团体心理辅导中的一些问题展开了反思。     

低维显式语义空间下的语义关联度计算方法

语义关联度计算是数据科学中的一个关键性基础问题,在信息检索及自然语言处理等方面有着广泛的应用.针对ESA (Explicit Semantic Analysis)算法存在的局限性,提出一种显式语义特征选择算法,并构建低维语义空间.在此基础上,根据特征概念在Wikipedia中的映射信息,提出一种低维显式语义空间下的语义关联度计算方法.该方法解决了ESA算法在后续语义关联度计算过程中,因高维稀疏空间导致计算效果不够准确的问题.实验结果表明,与当前其他方法相比,该方法的计算结果在皮尔逊相关系数(P)及斯皮尔曼相关系数(S)上与人们的认知判断之间具有更好的一致性.     

Microwave Solvothermal Synthesis,Crystal Structures and in Vitro Antitumor Activities of Di-n-butyltin Piperonylate with a Sn_4O_4 Ladder Framework

A two-dimensional supramolecular compound di-n-butyltin piperonylate, {(μ_3-O)(μ_2-OMe)(n-Bu_2Sn)_2[O_2CAr(C_2H_4O)]}_2 constructed by hydrogen bonds with a Sn_4O_4 ladder-like framework, was obtained by the microwave-assisted solvothermal reaction of di-n-butyltin oxide precursor with the piperonylic acid in methanol environments. The composite was characterized by elemental analysis and IR(~1H, ~(13)C and ~(119)Sn) NMR spectra. The compound crystallizes in monoclinic system, space group P21/n with a = 13.3690(12), b = 14.1442(14), c = 16.4022(16) ?, β = 107.191(6)°, V = 2963.0(5) ?~3, Z = 2, Dc = 1.520 g/cm~3, F(000) = 1368, μ = 1.719 mm~(-1), Mo Kα radiation(λ = 0.71073 ?), the final R = 0.0495 and w R = 0.1260 for 6780 observed reflections with I 2σ(I). Its X-ray crystallography diffraction analyses show a Sn_4O_4 ladder-like skeleton, in which two endocyclic tin and one exo tin atoms are bonded to the μ_3-O atom. In addition, one endocyclic tin and one exo tin atoms are respectively bonded to the μ_2-O atom from methanol. The ladder-like molecule has a three-ring fused skeleton, which is almost coplanar. The endocyclic and exocyclic tin atoms were all five-coordinated with distorted trigonal bipyramidal geometry. The antitumor activity showed that the compound had higher activities than cisplatin in HT-29, HepG2, MCF-7, KB and A549 cell line in vitro.     

包钢新体系热轧工程基础大体积混凝土的裂缝控制

本文结合实际工程包钢新体系热轧机组基础施工,就如何控制、解决大体积混凝土温度裂缝问题进行了探讨和研究,提出了有着可操作性和实际意义的一些措施及建议。分析结果表明,基础大体积混凝土施工中,应选取合适的原材料,进行合理的混凝土配合比设计,制定科学合理的施工方案,采取行之有效的监测方法,以控制温度裂缝的产生。