Assistant Pullback Technique for Main Span Closure of Sutong Bridge

Sutong Bridge is a cable-stayed steel box girder bridge with a main span of 1 088 m. The erection of upper structure adopts geometry control method and requires no change to the unit＇ s size and the structure＇ s none-stress geometry. Before main span closure, the cantilever of girder reaches 540.8 m, the structure state is noticeably influenced by extemal circumstances, the main span closure face great difficulty. By abstracting the advantage of the pullback method abroad and the domestic temperature-cutting method, a new assistant pullback method have put forward and bring into practice actually. In this paper, the analysis key point of practice conditions, key parameter of practice, main measures of the method and the performance is introduced.     

Fuzzy Variable Structure Control of Photovoltaic MPPT System

In order to reduce chattering phenomenon of variable structure control, a fuzzy variable structure control method is adopted and applied in the photovoitaic maximum power point tracking （MPPT） control system. Firstly, the electric features of PV cells and a dynamic model of photovoitaic system with a DGDC buck converter are analysed. Then a hybrid fuzzy variable structure controller is designed. The controller is composed of a fuzzy variable structure control term and a supervisory control term. The former is the main part of the controller and the latter is used to ensure the stability of the system. Finally, the conventional variable structure control method and the fuzzy variable structure control method are applied respectively. The comparing of simulation results shows the superiority of the latter.     

Identification of Modal Parameters with Linear Structure under Non-stationary Ambient Excitation

Empirical mode decomposition (EMD) is proposed to identify linear structure under non-stationary excitation,and non-white noise coefficient is introduced under the assumption of random signals consisting of white noise and non-white noise signals. The cross-correlation function of resoonse signal is decomoosed into mode functions and residue by EMD method. The identification technique of the modal parameters of single freedom degree is applied to each mode function to obtain natural frequencies, damping ratios and mode shapes. The results of identification of the five-degree freedom linear system demonstrate that the proposed method is effective in identifying the parameters of linear structures under non-stationary ambient excitation.     

Fast algorithm for inverting structure parameters of the horizontal multi-layer soil

A fast algorithm is presented to invert the structure parameter of the horizontal multi-layer soil. The procedure is divided into two independent stages. First, Fredholm equation of the first kind with respect to the apparent resistivity is solved by the technology of decay spectrum to reduce computation time greatly. Second, the structure parameter of soil is determined by the generalized Newton-Kantorovich method, which is more robust and less noise sensitive because of using the generalized inverse algorithm to solve the nonlinear equation group. The numerical results show the validities and main features of the proposed approach.     

Bearing capacity analysis of reinforced concrete L-shaped cross-section under biaxial eccentric compression

The ultimate capacity of short L-shaped reinforced concrete (RC) members subjected to biaxial eccentric compression is investigated to provide a new tool for structure engineers. On the basis of nonlinear analysis of RC arbitrary cross-section, a new simplified cross-section numerical integration method is suggested. The cross-section is divided into several triangles, and each one is integrated with Gauss integration method. And L-shaped cross-sections subjected to biaxial eccentric compression are analyzed. The interaction curves of (N-M) and (My-Mz) for L-shaped sections are derived. The analytical results are well consistent with the experimental data and other analytical results.     

Pre-Stressed Rope Reinforced Anti-Sliding Pile

Pre-stressed rope reinforced anti-sliding pile is a composite anti-sliding structure. It is made up of pre-stressed rope and general anti-sliding pile. It can bring traditional anti-sliding pile＇s retaining performance into full play, and to treat with landslide fast and economically. The difference between them is that the pre-stressed rope will transfix the whole anti- sliding pile through a prearranged pipe in this structure. The working mechanics, the design method and economic benefit are studied. The results show that the pre-stressed rope reinforced anti-sliding pile can treat with the small and middle landslides or high slopes well and possess the notable advantage of technology and economic.     

Numerical verification of geometry control method of the construction for super span cable stayed bridge

Take Sutong Bridge as object investigated, the correctness of the geometry control method is verified by the numerical simulation analysis. Taking the impact of geometric nonlinearity into account, the impacts of structural geometric profile induced by temporary loads and temperature field during the construction procedure are investigated. The simulation results indicate that only the stage state of the structure during construction is affected. Satisfied outcome of construction control can be achieved based on geometry control method.     

Progress in magnetic couple system of nitroxidemetal complexes

Metal_radical method is an effective approach to synthesizing magnetic molecular materials. With the development in decades, the study of nitroxide_metal complexes has made great progress in model, theoretical treatment and design of molecules. Several mechanisms of the metal_radical magnetic coupling are discussed. Molecular magnetic project of nitroxide_metal complexes has made fruitful achievements, but crystal magnetic project is difficult to be controlled, and it is a challenge to chemists. The studies on nitronyl nitroxide_metal complexes are summarized. At present, there are three major approaches to increasing the T c of the metal_radical compounds: (ⅰ) Searching for nitronyl nitroxide ligands that can yield 3_D ferro_ or ferrimagnetic structures; (ⅱ) decorating the structure of radicals with the aim to enhance the coordinate capability of radicals; (ⅲ) grafting polynitroxide radicals as a versatile bridge. The third approach, namely searching for polynitroxide ligand, will serve as a hopeful strategy for exploring higher T c radical molecule_based magnets.     

Fine structure and phase composition of Fe–14Mn–1.2C steel:influence of a modified mixture based on refractory metals

The effect of TiO_2,ZrO_2 and Na_3AlF_6 ultrafine powders on the fine structure and the phase composition of Fe–14Mn–1.2C steel was investigated.The introduction of the ultrafine powders into the melt influenced the grain size,the quantity,and the character of distribution of nonmetallic inclusions in the railroad frogs.The microstructure of castings was improved significantly because of the refinement of the grain structure and an increase of the grain-boundary area.After the modifying mixture was introduced into the melt,either the microtwins of one or two intersecting systems or the precipitations of ε-martensite of different types,or simultaneously the microtwins and wafers of ε-martensite,were present in each grain.     

以古琴打造岭南文化特色刍议

古琴艺术是一种文化象征，它折射出当今世界依然耀人的中华文化的思想光芒，引领烦躁不安的现代人类返朴归真，转向大自然的山水天地之间。保护和发展古琴艺术，不仅是某种艺术样式的延续，更是精神文明建设的必须；不仅为了重温古老的历史，更是为传统的文化艺术融进今日世界潮流的必须。岭南古琴的演奏营造了清、微、淡、远的意境；构筑出抒情达...     

中国古琴文化初探

作为中国文化传统之集大成者,古琴在其漫漫的历史长河中,琴与琴人之间有着数千年的痴缠,琴成为琴人精神上的知己。无论闻达于诸候,还是归隐于田园,古琴都在琴人的身边,传着先哲的智慧,慰藉着琴人的心灵。     

基于商务主体的电子商务新分类

将电子商务公司区分为普通电子商务公司、平台型电子商务公司和中介型电子商务公司,给出了同时基于交易主体和商务主体的新的电子商务分类体系。该分类体系可以更加清晰地显示出商务主体在价值链中扮演的角色。传统的电子商务分类记号,例如B2B,B2C等,是按照交易主体进行的。在平台型和中介型电子商务公司风行的今天,这种分类体系容易混淆一些电子商务的基本区别,造成一系列问题。以网络团购为例说明了这一新的分类体系的优越性。按新分类体系,网络团购归为bAc,这远优于旧分类体系将其归为B2T或C2B。分析了的缺陷,然后,并且提出了的建议通过     

论刀具座标系统与刀具命名法

本文旨在介绍ISO3002/I的主要内容,并对刀具参考座际系的建立和对刀具角度标注体系进行分析和归纳,综合有关学者论述首先采用了“刀具命名法”这一术语。指出法前角命名法和正交前角命名法的物理意义明确,应优先采用,而进给前角命名法在描述刀具切削性能方面不够直观,但在刀具设计计算中仍占有重要地位;至于最大前角命名法从刀具技术的发展角度来观察,仍具有一定的实际意义;这正体现了ISO新标准的完整性。     

高性能与自密实混凝土技术在琴台大剧院中的应用

作为第八届中国艺术节的主会场,琴台大剧院工程是国家的重点工程.由于工程的复杂性,使得超长、超大面积及大体积混凝土是本工程结构的重要特点,其裂缝控制、混凝土的耐久性能成为了工程施工的重点与难点.为此,针对工程中所选用的材料情况,通过试验研究,制定出了能较好满足工程实际所需的高性能与自密实混凝土配合方案与施工方法,为工程质量的确保提供了技术上的支持.     

琴歌一曲古怨长——姜夔《古怨》之审美赏析

姜夔的琴歌《古怨》是姜夔作品中唯一一首琴歌作品,形式和内容有别于其他形式的曲辞,有着独特的审美特点。此琴歌用的是侧商调,调式古老流美,旋律古雅悠长。琴歌曲词分为三个部分,分别有着烟雾迷津中的苍茫缥缈,黍离之悲哀婉凄凉,野云孤雁的清空洒脱等审美特点。这些特点与作者的身世和所处环境相关。此外,作品中双关,隐喻,用典等艺术手法的运用恰到好处。此琴歌抒发了作者对身世凄凉,世道变迁,家国破碎的感叹。     

镇江六朝时期琴文化源流谈略

古琴是最具中国人文内涵的古老乐器。镇江的琴文化具有深厚的底蕴。六朝时期,卓越的琴人、著名的琴事与镇江有关,在中国琴史上开一代风气。主要表现为:礼乐教化思想与隐逸之风并存,共同促进琴文化的发展;琴学成就卓著,为六朝文学增添了优雅的光彩;对后世琴学产生深远的影响。     

基于部件融合的“我”体字库的建立

为丰富计算机字库,传承中国文化,减少人工手写工作量和汉字图像字库的存储量,提出了一种基于部件融合的“我”体个性字库的建立的方法。该方法通过提取个人手写稿的部件与352个部件匹配,由Gabor小波提取部件特征,利用仿射变换和图象卷绕来实现部件融合为“我”体汉字。试验表明,该方法可行,在减少人工手写工作量和降低汉字图像字库的存储量上具有显著的优点。     

基于多源信息空间的遥感影像自动解译研究

通过分析遥感影像自动解译的研究现状和存在的问题,提出了基于多源信息空间的遥感影像自动解译的研究方法,将遥感影像分为光谱信息空间、形状信息空间、区域地学信息空间、干扰信息空间等四个信息空间,通过对多源信息空间的数学描述和计算机处理实现了遥感影像的自动解译.     

古琴、士与中国文化

古琴,作为我国传统音乐中极具代表性的一种乐器,一千五百年来一直被士所推崇,二者互为作用共同形成了了异常深厚而又丰富的文化积淀,并成为融合中国古典哲学、文学、史学等传统文化的综合文化、震颤人心的心灵文化。