对2,4-二羟基吡啶的各种异构体分别在气相和溶液中进行了理论计算,探讨了各异构体的相对稳定性以及溶剂对其互变异构性质的影响.结果显示,该化合物在气相时以2,4-二醇式为优势结构,然而由于溶剂的极化作用,导致其在溶液中表现出2-酮-4-醇式结构.

Ab initio calculations have been performed for all isomers of 2,4-dihydroxy-pyridine in the gas phase and in aqueous solution. The results obtained indicate that 2,4-diol- form of the title compound is the most stable among all tautomers in the gas phase, however, due to polarization effects of solvents, 2-keto-4-ol form is the preferred tautomeric form in aqueous solution.

合成了一种随pH值变化具有5种互变分子结构的新型荧光素衍生物QHF+。通过紫外-可见吸收光谱研究了不同pH值下QHF+发生转化产生的5种结构的特征谱图，并以此为基础设计了二进制逻辑电路。在乙醇/水(体积比为1：1)混合溶剂体系中，采用等摩尔的H+或OH-作为化学输入信号，选取424和490 nm波长下的特定吸光度或透射率作为标准阈值，通过比较紫外-可见吸收光谱的变化，平行实现了多个逻辑门( XOR和INH或AND和XOR)的运算，模拟了二进制全减器和全加器的运行。

Over the past decade, there has been significant progress in the development of molecular compu-ter, which has inspired scientists to construct appropriate molecular systems that could integrate simple logic gates into combinatorial circuits. In this work, a novel fluorescein-based QHF+with five-state molecular switch was synthesized. The conversion of the five states of QHF+was observed by UV-visible absorption spectra un-der various pH values in CH3CH2OH/H2O(volume ratio 1:1). Spectral responses with the use of chemical inputs in the form of H+and OH-revealed that QHF could function as a combinatorial logic circuit( XOR gate and INHIBIT gate, AND gate and XOR gate) . Absorbance change at 424 and 490 nm or transmittance change at 424 nm, was monitored as output signals with threshold value of A=0.209 ( or T=61.8%) . When absor-bance intensity or transmittance percentage was more than the threshold value, the output signal was 1. Other-wise, the output value was 0. In conclus

框剪结构是由框架结构与剪力墙结构有机结合而成，具备框架结构与剪力墙结构的优势。传统剪力墙结构在应用中具备其独特优点。本文分析框剪结构与剪力墙结构基本设计，从结构稳定性、成本、实用性三个方面，对框剪结构与剪力墙结构性能进行对比。

Frame shear structure is composed of frame shear structure and shears wal structure, which has the advantages of frame structure and shear wal structure. The traditional sh-ear wal structure has its unique advantages in the application. The author analyzes the basic design of frame shear structure and shears wal structure, and compares the frame shear str-ucture with shear wal structure performance from three asp-ects of the structure stability, cost, and practicability.

组合结构的使用已经广泛,其中钢与混凝土的组合结构是最为常见的结构形式,而且相当成熟,已经自成独立的结构体系。在我国,组合结构仍属新的结构形式,随着大量建筑物的兴建,组合结构作为新兴结构得到越来越广泛的采用,应用前景越来越好。所以,对钢与混凝土组合结构的结构形式及性能特点有一定的了解是很有必要的。本文就这些方面对不同的组合结构形式展开介绍。

The composite structure has been used widely, then steel and concrete composite structure is the most common type and quite mature, so it has become the independent struc-ture system. In our country, the combination of structure is still a new structure form with the construction of large number of buildings, combination structure, as an emerging structure, will more and more widely used, and the application prospect will be better. Therefore, the combination of steel and concrete struction of different structure form will be introduced.

对天津地铁1号线西站车站及隧道在地表荷载作用下产生的沉降进行了现场监测和有限元分析,由于变形缝的存在使结构沉降表现为非连续性;地表荷载下基底土体产生塑性应变导致卸荷后结构仍存在不可恢复的残余变形;侧向地表荷载会导致结构产生较大的倾斜差异沉降并使结构扭转.在此基础上研究了地表荷载位置、结构埋深因素对于存在变形缝的地铁结构箱体变形的影响.结果表明:变形缝的存在会削弱结构刚度、加剧结构沉降以及结构间的差异沉降,并且不同荷载位置下结构的沉降特点也各不相同.此外,对于浅埋结构,荷载位置距结构越远,结构的变形越小,且结构埋置越深地表荷载对结构的影响也越小.

The settlement due to ground loading was observed in the West Railway Station subway station of Tianjin Metro Line 1. Besides,the deformation characteristics of structure were analyzed by field measurements and finite element method. The results show that the settlement curve is discontinuous at the structural deformation joint. After the removal of ground loading,the structure suffers from unrecoverable residual deformation,since the ground load-ing causes the plastic strain of the surrounding soil. The lateral ground loading leads to differential settlements and hence twists the structure. Furthermore,the effects of the loading location,buried depth of the structure on the de-formation of the discontinuous metro station boxes were studied. It is found that the structural deformation joint can weaken the structure stiffness and increase the settlement and differential settlement of the structure. The deformation characteristics also vary with different loading locations. Additionally,