深孔毫秒延时挤压爆破技术在秦山石料厂的应用

在石料开采工程中,应用深孔毫秒延时挤压爆破技术,减少爆破震动危害,石料块度比较理想,取得良好的爆破效果。本文详细介绍了爆破方案的确定、爆破孔网参数的设计,并结合现场地形、地质条件的变化不断对其进行校正和优化。     

深孔毫秒延时挤压爆破技术在秦山石料厂的应用

在石料开采工程中,应用深孔毫秒延时挤压爆破技术,减少爆破震动危害,石料块度比较理想,取得良好的爆破效果。本文详细介绍了爆破方案的确定、爆破孔网参数的设计,并结合现场地形、地质条件的变化不断对其进行校正和优化。     

高砾石土心墙堆石坝过渡料爆破直采技术探讨

通过长河坝水电站石料场的多次现场爆破试验,结合KUZ-RAM块度预报模型,对试验成果与设计要求的级配曲线进行对比分析。对于料源为裂隙发育的花岗岩、石英闪长岩等硬岩,选择可爆性较好区域、采用降低孔网面积、加大爆破单耗、选用2号岩石乳化炸药和高精度导爆管雷管、利用微差挤压爆破等技术,可以获取合格过渡料以达爆破直采之目的。爆破平均块度可通过缩小钻孔直径、控制台阶高度、降低单孔装药量、采用合理装药结构及起爆网路来控制。     

分形理论与岩石爆破块度的预报研究

根据分形几何理论，研究了岩石爆破块度的分形特征，发现岩石的爆破块度具有良好的分形结构。探讨了爆破参数与爆破块度分维数之间的关系。笔者认为，对一直困扰我们的由岩石特性引起的爆破成缝的随机性、不规则性和爆破块度分布的复杂性，分形理论可能为岩石爆破后的块度估算、爆前块度的预报和爆破参数的优化研究开创一个新的生长点。     

用预破碎药包控制定向爆破堆体块度的初步研究

爆堆体的块度分布随着定向爆破筑坝技术的发展,人们逐渐认识到,爆堆的块度分布是评价爆破效果的重要指标之一。所谓爆堆体块度分布,其含义应是:岩块的大小、岩块颗粒级配,及     

石碴坝坝料开采的块度控制

堆石坝、石碴坝坝料的块度级配控制是坝体稳定和质量的重要保证。本文介绍了沉抗水库心墙石渣坝工程的采料爆破。通过相向对称微差挤压爆破 ,合理选取爆破参数以及采用多孔粒状铵油炸药 ,使坝料块度和级配得到了良好控制 ,提高了坝体工程质量 ,加快了施工进度 ,可供同类工程借鉴。     

炮孔水压爆破及其应用

文中论述了炮孔水压爆破的基本原理，分析了炮孔水压爆破在混凝土基础，大块岩石的二次破碎、深孔底剖水间隔装药爆破及蓼产是爆破中的具体方法和工艺过程。最后指出，炮孔水压爆破具有爆破块度均匀等优点，是安全，经济和有效的爆破技术。     

印度河55号公路12B项目岩石爆破技术与特点

细介绍了印度河５５号公路１２Ｂ项目道路岩石爆破技术与特点。对公路工程石方爆破中常出现的诸如岩石爆破块度控制、爆堆控制、爆破飞石与地震控制及降低爆破费用等问题，提出了相应的对策。     

矿岩爆破图像二值化分割技术的研究与选择

爆破块度图像分析法是当前爆破块度统计的重要方法,图像分割技术是该分析方法的关键与难点。针对爆堆及块石图像的特殊性,研究了基于二值化的矿岩爆破图像分割技术,分析了阈值分割、区域生长分割、标记分水岭分割等当前主要的图像分割方法。通过研究图像上同一截面灰度值切片的变换与矿块实际边缘的吻合程度,发现数学形态学分割方法得到的二值图像边界清晰、断点少,相对于门限法更适用于爆破块度图像,其生成的二值化图像层次清晰,便于像素特征的提取。图像分割先进技术的应用,对于实现矿岩爆破图像块度分析的智能化提供了广阔的空间。     

逐孔起爆在高速公路路堑开挖中的应用

阜朝高速公路施工中,有大量的土石方需要爆破,用传统的爆破方法会出现爆破振动大、爆破次数多、块度大的问题。通过方案对比决定采用逐孔起爆技术,这种爆破方式能进行一次爆破、振动小、块度均匀。本文介绍了逐孔起爆原理、爆破参数设计及网路的连接,同时对爆破振动进行了安全校核并对爆破飞石进行了控制。     

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.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

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.