复杂环境下框剪结构烂尾楼定向爆破拆除

根据框架-剪力墙结构烂尾楼的结构特点,以及周边环境情况,采取"Ⅰ区、Ⅱ区依次向东定向倒塌"的总体爆破方案。由于倒塌空间有限,为减小大楼的倒塌距离,将Ⅰ区的爆破切口提高至5层,Ⅱ区延迟Ⅰ区460 ms起爆。运用LS-DYNA动力学有限元软件,验证了爆破总体方案的合理性,计算得到的倒塌运动过程和堆积形态与实际效果比较吻合。结合现场踏勘情况,对大楼的爆破倒塌效果进行了详细分析,结果表明:采用"分区间隔延时"爆破拆除框剪结构大楼时,合理的爆破切口高度和延期时间是关键;在定向倒塌方案中,为降低爆堆高度,需要对梁结构进行爆破弱化处理。     

复杂环境下12层框剪结构楼房爆破拆除

介绍了复杂环境下一栋12层框剪结构楼房的爆破拆除工程实例。采用10.4m高的复合梯形爆破切口、楔形半秒孔内延时,分3个爆区三响总延时1 020ms,实现了楼房的整体定向倒塌;通过确定合理的爆破参数、充分的预处理、间隔装药结构、双回路起爆网路等技术措施确保了安全准爆和精确定向倒塌;通过铺设缓冲垫层、炮孔包裹防护、搭设防护屏障等措施有效控制了爆破塌落振动及飞石的危害。楼房按照设计方向倒塌在设计范围内,周围建(构)筑物均没受到影响。该爆破拆除工程在精确定向,控制塌落振动及飞石等方面取得了较好的效果,可为同类工程爆破施工提供参考。     

框架核心筒结构高层建筑的对向倒塌爆破拆除

介绍了城市复杂环境中采用双切口对向倒塌爆破拆除两栋高层框架核心筒结构大楼的工程实例。根据框架核心筒结构特点,结合场地周边环境,选择对向倒塌的爆破方案。先爆建筑采用双切口方式,后爆建筑采用单切口方式,通过四通与簇联相结合的复式起爆网路,楼间间隔3 s延时起爆,实现大楼逐栋倒塌解体;采用主动防护与被动防护相结合的安全防护技术,有效地控制了爆破振动、塌落振动和爆破飞散物,取得了良好的爆破效果。     

折叠爆破技术在框剪结构大楼拆除中的应用

采用折叠爆破技术,在复杂环境下对84.8m高的框剪结构大楼实施了爆破拆除。通过精心设计,采取合理的安全防护措施,保证了爆破的安全。爆破后楼房实现了折叠倒塌,爆堆在设计范围之内,周围设施完好无损,可为类似工程提供借鉴。     

框剪结构高楼纵向倾倒拆除爆破研究

我国目前用爆破法拆除的高层楼房主要是框剪结构。根据同一楼房中框架部分与剪力墙部分的相对位置、倒塌方向选择、前后段起爆时差,对框剪结构楼房爆破效果的影响等进行了分析,给出了楼房爆破切口倾角(闭合角)的经验数据、理论计算方法及确保楼房倒塌的判据,指出了楼房沿其纵向倒塌的难度远大于横向倒塌,并以靖江金都大厦的爆破为例,详细介绍了楼房沿其纵向倾倒时的爆破方案确定、预处理方法、爆破切口要素、立柱的爆破破坏高度、药孔参数、爆破参数、起爆网路等。靖江金都大厦为框剪结构的11层高楼,因环境限制,需要沿其不利于倒塌的纵向倾倒,而剪力墙结构却位于高楼的纵向两端,对该大楼的倒塌带来极大难度,通过精心设计其爆破方案,优化爆破参数,并采取严格的安全技术措施,完全达到了预期的爆破效果。     

控制爆破拆除十六铺客运大楼及申客饭店

上海十六铺客运大楼和中客饭店大楼拟予爆破拆除,但爆区周边环境复杂.为减少拆除建筑结构倒塌着地振动,确保近侧防汛墙的安全,采用了非电复式起爆网路,逐跨倒塌或多层爆口延期的控制爆破方案.分别给出了2幢大楼拆除爆破参数、起爆延期时间及安全防护措施.爆破取得预期效果,周边安全无恙.     

全剪力墙结构楼房的定向爆破拆除

介绍了全剪力墙结构楼房的定向爆破拆除。根据楼房剪力墙特点和周围环境,选择向北部空地定向倒塌的爆破方案,对1~4层剪力墙、楼梯进行局部预拆除;选择三角形爆破切口,采用四通与“大把抓”相结合的复式起爆网路,整体对角式延时起爆技术,实现大楼剪切解体;采用主动防护与被动防护相结合的安全防护技术,有效地控制爆破振动、塌落振动和爆破飞散物,取得了良好的爆破效果。     

复杂环境下框架-框剪结构厂房定向爆破拆除

8层待拆钢筋混凝土框架-框剪结构厂房,1～3层为大框架结构,4～8层为框剪结构,立柱种类多,周围还有大量生产设备和建筑物。通过对厂房自身结构特点及周围场地条件的分析,采用"三角形爆破缺口、分区分段逐次向北倒塌"的起爆方案。采用高爆破缺口,计算了分区各层破坏高度,并对爆破缺口内的不同尺寸立柱、横梁、剪力墙进行了爆破参数计算,并对同一立柱的不同炮孔进行不同的装药结构设计。起爆网路为非电导爆双回路闭合复式网路,采用一次起爆分区延期的方式,爆破缺口共分为3个区,每个分区间隔时间为0.5 s微差,爆破效果良好。     

部分13层框剪结构楼房的控制爆破拆除

待拆13层钢筋混凝土框剪结构物是病房楼东侧的一部分,东西长11 4m、南北宽18 6m、高45m,剪力墙厚20cm和25cm。采用单向折叠定向倒塌的方案,使结构从南到北逐段微差起爆和解体。文中介绍了爆破切口高度的确定、钻孔爆破参数的选取、爆区的划分、起爆顺序、预处理以及安全防护措施。同时对倒向偏差的原因进行了分析。     

18层“高脚杯”形剪力墙结构楼房爆破拆除

采用分区延时定向爆破设计方案拆除了一座18层"高脚杯"形全剪力墙结构大楼,为保证楼房倒塌后的充分解体,对大楼进行了大量弱化预处理。为控制爆破有害效应,采用了严密的安全防护措施。爆破后,楼房各分区按设计依次倒塌解体,爆破有害效应得到有效控制,取得了良好的爆破效果,可为类似工程提供借鉴。     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.