特殊结构楼房的水压爆破拆除

利用水压控制爆破技术拆除特殊结构楼房。介绍了特殊结构二层楼房(下层浆砌石结构,上层砖砌结构)的水压爆破拆除,通过爆破方案的选择,预拆除范围、爆破参数以及爆破施工工艺的确定,并采取可靠的爆破安全措施,不仅加快了工程进度,节约了施工成本,且达到了理想的爆破拆除效果。     

水压爆破拆除大板居民楼群

针对预测空心砼大板结构楼房的特点，提出了微型水压爆破拆除方案；详细描述了爆破制品布置方法，微型水压爆破注水，布药，安全防护等施工过程。     

水压爆破在特殊结构构筑物拆除中的应用技术

在适宜采用水压爆破的环境下,采用水压爆破比常规钻孔爆破拆除有显著的优越性,因此水压爆破得到越来越广泛的应用。本文着重介绍了水压爆破在各种特殊结构构筑物拆除中的应用技术,以及新发展的一些水压爆破技术和水压爆破的一些通用技术规则。     

复杂环境下“L”型框架楼房定向爆破拆除

介绍了9层"L"型框架楼房整体倾倒爆破拆除施工方案。爆破拆除楼房结构比较特殊,且爆破周围环境较为复杂。根据楼房"L"结构特点,采取前后上下各设两个爆破切口的技术方案;上下切口延时300 ms,前后切口延时880 ms的起爆网路;并通过采用爆破体多层近体防护及消防水幕墙双层降尘等措施,有效控制爆破有害效应。楼房爆堆范围和高度符合设计要求。     

高大凹型结构楼房爆破后坐分析

为了避免和预防楼房爆破拆除出现后坐而造成的危害,根据建筑物爆破拆除过程中常出现的后坐现象,总结出3种基本形式:楼房倾而不覆;楼房虽倾覆,但解体和爆破效果差;楼房倾覆,但后坐严重,破坏了需要保护的建(构)筑物。结合高大凹型结构、重心偏离中心线楼房的爆破案例,对楼房爆破拆除的后坐现象进行了分析,产生后坐的原因有结构分析不彻底、延时时间设置不当等等。为此,提出了特殊切口、降低局部强度、控制楼房塌落倾斜加速度、改变起爆方式、减小支撑体与紧邻前部的延时时间等相应的解决措施。爆破案例的爆破效果说明了预防楼房爆破后坐必须从爆破方案设计开始,对整个爆破过程进行周密的预见性分析。分析结果对今后类似楼房的爆破拆除具有借鉴意义。     

爆破拆除大型油罐

本文详细介绍了在特殊场所——油库内应用以水压爆破为主,水压爆破与炮孔爆破相结合的方法,成功地拆除了结构复杂的大型油罐的工程实例,为今后类似条件下的拆除爆破提供了经验。     

一次性爆破拆除1O栋楼房的总体方案设计

介绍了10栋楼房的一次性爆破拆除方案,采用了楼体内特殊结构先爆破、小高度切口控制楼房后坐塌落以及有效的防护措施等技术手段,在周边环境特别恶劣的条件下取得较好的爆破效果。     

水压爆破拆除七层大板楼

介绍用水压爆破拆除七层大板结构楼房的实例。楼房的一至三层上砌筑大小不等的水池共 86个 ,池中共设置药包 196个 ,用药 5 7 8kg。水中药包连同少量辅助炮眼药包一次起爆 ,获得预期爆破效果。文中概述了爆破方案确定、药量计算、药包的防水处理和布置 ,以及主要技术措施等。     

镇江6栋楼房控制爆破拆除

镇江6栋楼房一次性定向控制爆破拆除,其特点是每栋楼房具有不同的高度和结构,需要针对每栋 楼房的特点和环境情况确定其爆破切口的参数和倾倒方向来进行控制爆破拆除.介绍了爆破的难点、网路设 计和爆破方案.爆破结果表明,通过精心设计和施工,解决了复杂环境下爆破拆除大面积建筑群的问题.     

复杂环境下9层框架楼房切割定向爆破拆除

介绍了在闹市区复杂环境下特殊框架结构楼房需部分保留、部分拆除的切割定向爆破拆除方案及相关爆破参数。立柱部分采用切割爆破技术,楼房采用单向折叠的爆破方案,选取合理的爆破参数,通过精心组织施工,在爆破过程中成功的保护了楼房的保留部分。最后,对爆破效果和施工经验进行了分析和总结。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

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.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

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.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

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.