海拉尔季节性冻土爆破参数试验研究

为获取海拉尔地区季节性冻土的爆破方案,采用大孔径浅孔爆破技术对宝日希勒露天矿进行现场试验,研究黑粘泥冻土的单轴抗压强度及大孔径浅孔爆破参数。试验结果表明黑粘泥冻土的单轴抗压强度值为3.751MPa,孔网参数5m×4m、孔径150mm、孔深2.5m、单耗0.32kg/m3方案的爆破效果表明其剥离深度及破碎块度能够满足生产及工程机械开挖的要求。该研究结果对季节性冻土爆破工程具有一定的参考价值和指导意义。     

红沿河核电站核岛环廊控制爆破技术

通过红沿河核电站核岛负挖工程爆破实例,介绍了CPR1000型核电站核岛环廊预裂爆破、掏槽爆破的设计思路和施工要点。采用了中孔径浅孔分层掏槽爆破方案,加快了施工速度,保证了环廊壁面和基底建基面质量。该工程爆破施工后,核岛环廊成型较好。     

高强度土石方深孔药壶爆破技术

深孔药壶爆破技术目前尚未形成一套完善的工艺,采用这一技术结合浅眼药壶爆破在珠海临港工业区大平湾二期填海工程中的成功应用,不仅满足月产量150万m3的施工要求,而且还大大降低工程施工成本,提高了工程效益.介绍采用孔径140mm的深孔药壶爆破结合浅眼扩壶爆破的施工工艺及参数计算方法.     

复杂条件下多种控制爆破技术的综合应用

某体育训练场地平整工程爆破环境十分复杂,为了控制爆破飞石和爆破震动对附近设施、地下管线等的影响,采用小孔径和密孔距的控制爆破方法施工。为了保证工程进度,开挖深度小于1 m时,采用40 mm的孔径爆破;开挖深度大于1 m时,采用76 mm的孔径爆破,且最大孔深控制不超过4 m。浅孔爆破采用孔口覆盖沙包、钢板来控制飞石,限制最大单孔药量来控制爆破振动。另外为了保证场地边界及基坑的平整,在边坡处采用预裂爆破,通过在相邻预裂孔中间布置空孔的方式增强预裂效果,且预裂孔的两端布置一般要超出主爆孔5~7个孔的长度,以避免主爆孔爆破对保留岩面的破坏。     

浅孔爆破与药壶爆破综合应用实践

在 32 9国道K110 +4 6 0 -K110 +740段路堑爆破开挖中 ,采用常规的浅孔控制爆破与药壶控制爆破相结合的施工方法。当开挖厚度小于 2m ,或安全要求特别高的作业点 (如高压线下 ) ,采用浅孔爆破 ,并利用浅孔爆破为药壶爆破施工开创工作面与自由面。本文介绍了浅孔爆破和药壶爆破参数的选择、扩壶工艺以及有关两种爆破方法综合应用的经验和认识。     

船坞改扩建工程围堰拆除爆破技术

针对船坞改扩建工程中围堰拆除爆破周边环境复杂、围堰结构复杂且爆破预处理工程量大的问题,根据待拆除围堰的特点和多年来总结的类似工程经验,对船坞围堰爆破设计施工方案进行了综合分析和比较选择,最终设计选择"竖孔和斜孔结合、坞内充水、低潮位一次性起爆的方案";采用竖向浅孔爆破使梁与桩解体分离,采用竖向深孔爆破使桩基底部松动和破...     

复杂环境下楼房深基坑岩石控制爆破安全技术

为提高爆破施工安全,严格控制爆破振动和飞石,设计了某小区楼房深基坑岩石控制爆破方案,对比三种爆破方案,优选了其中一种方案。在施工过程中采用中深孔微差控制爆破,辅以浅孔施工;使用分段分区分台阶的爆破方法,其中控制爆破Ⅰ区、Ⅱ区、Ⅲ区钻孔深度分别为2.5 m、3 m、3.5 m,并于施工前进行爆破振动计算和施工过程中进行爆破振动的监测,监测区最大振动速度2.05 cm/s,最小振动速度1.16 cm/s,并根据测试结果对台阶高度、孔网参数和起爆规模进行调整。爆破施工结果表明:爆破网路参数安全可靠,爆破振动在安全允许范围内,无爆破飞石产生,提高了炸药能量利用率并改善了爆破效果,确保了爆破施工的安全。     

复杂环境下路堑开挖大孔径控制爆破

舞钢市中心大道路堑开挖爆破区地处市区,周围建构筑物繁多、条件复杂,采用大直径浅炮孔平地掏槽和减弱松动爆破,成功实施了一次性起爆,爆破效果良好.给出了该爆破工程的方案选择、参数设计和安全防护措施.     

复杂环境下危石的爆破处理

针对危石周边环境复杂环境的特点,提出了用弱松动浅孔控制爆破来进行处理的方案.为防止飞石和危石解体后的小块石滚落山下伤及人员,采用了在危石正前方设立挡墙、胶皮网进行覆盖,选择合理的爆破参数及分层处理等措施;为防止在施工过程中危石滑落,采用木料支撑和锚杆暂时固定,确保了危石安全、快速的清除.     

浅孔台阶爆破的合理性研究

在台阶爆破中,台阶高度增加到一定值后,需保持孔排距不变,以优化爆破效果.在现场针对三种不同孔径及不同台阶高度的爆破进行试验,得到孔径76 mm的浅孔台阶爆破较深孔台阶单耗低,台阶高度小于12 m时,单耗随台阶高度变化大,当台阶高度大于12 m时,单耗变化率变小,此时宜进行爆前准备阶段爆破参数优化.为便于在现场直接根据台...     

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.     

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.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.     

新闻(英文)

正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to