条形药包爆破理论与技术

介绍了条形药包爆炸应力场、条形药包爆破震动场的最新研究成果 ,由此还解释了条形药包的定向作用原理。另外 ,根据土中模型试验 ,对条形药包的爆破漏斗特性作了总结 ,讨论了条形药包长抗比对装药量计算的影响 ,并介绍了条形药包硐室爆破设计方法和爆破施工组织管理的经验     

条形药包爆爆应力场试验研究

应用动态光弹性模型测试方法研究了条形药包的爆炸应力分布特性，研究结果表明，起爆方式和位置影着条形药包爆炸应力场的分布形太，并首次成功地记录了条形药包瞬间爆炸应力场的动光动条纹，得到了理想应力场的分布形态。     

条形不偶合平面药包硐室爆破在路基开挖中的应用

在路基开挖中采用条形药包硐室爆破，通过对条形不偶合平面药包作用机理的分析，指出条形不偶合装药能减小爆破振动对后边坡和路基的破坏影响，因而可减小药包设计的保护层计算厚度；通过对条形药包和集中药包应用特点的比较，提出了沿路基线型尽可能布设条形药包或准条形药包以及辅助集中药包等不同的处理方法。在较高边坡开挖中布置小抵抗线条形平面药包，减小了爆破振动，提高了有效抛掷率，保证了高边坡的平整和稳定，经济效益显著。     

硐室爆破条形药包设计中的有关问题

综述了集中药包和条形药包的应用条件 ,介绍了硐室爆破中条形药包的优越性、药包的分类、药包间距以及装药量和压缩圈半径的计算 ,论述了条形药包设计时应注意的问题、条形药包布置时有关问题的处理办法、起爆技术以及堵塞工作中应注意的问题。这些可为硐室爆破工程作参考     

黑沟主堆上坝料开采硐室爆破

介绍黑沟主堆上坝料开采硐室爆破所采用的特殊方法.在硐室掘进过程中,由于施工的其中一条硐室掘进控制导线与设计方位线偏差,导致药室的最小抵抗线由原设计的40 m增大到实测的57 m,调整装药结构、装药位置及条形药包的装药量,合理利用已掘进成形的药室形状采用条形聚能药包进行超大抵抗线硐室大爆破.对于条形药包的端部采用类哑铃形装药结构,加大条形药室端部药量的措施.利用喷雾器实现湿式钻眼.查阅、检索到相关资料,未找到超过57 m抵抗线、类哑铃形装药结构和喷雾器硐室大爆破的相关报道.     

柱状药包岩石中爆炸的数值模拟

利用ANSYS/LS-DYNA3D对柱状药包在半无限岩石介质中爆炸情况进行了数值模拟,对柱状药包的爆炸在岩石内产生的应力变化进行了分析。给出了岩石弹性区内一点的应力变化时程曲线;并借助球形装药的经验公式对柱状装药的情况进行了分析比较,结果表明,应力波的峰值基本一致。该时程曲线可以用于多孔爆破计算。     

柱状药包岩石中爆炸的数值模拟

利用ANSYS/LS-DYNA3D对柱状药包在半无限岩石介质中爆炸情况进行了数值模拟,对柱状药包的爆炸在岩石内产生的应力变化进行了分析。给出了岩石弹性区内一点的应力变化时程曲线;并借助球形装药的经验公式对柱状装药的情况进行了分析比较,结果表明,应力波的峰值基本一致。该时程曲线可以用于多孔爆破计算。     

条形药包爆炸应力场试验研究

应用动态光弹性模型试验方法研究了条形药包的爆炸应力场分布特性。研究结果表明：起爆方式和位置影响着条形药包爆炸应力场的分布形态，并首次成功地记录了条形药包瞬间爆炸应力场的动光弹条纹，得到了理想成力场的分布形式。     

岩石中爆炸应变波信号测试与分析

针对岩石爆破过程中爆炸应变波信号易失真、难测试的特点,建立了一套稳定可靠的超动态应变测试系统.实测了小药量耦合装药在岩石模型中爆炸产生的径向爆炸应变波信号,得到了装药爆炸应变波形的特点以及应变峰值与药包长径比、药量、相对距离的变化关系.试验结果表明:(1)岩石爆破过程中爆炸波综合作用时间约为10μs,表现出初始以压应力为主,持续的压、拉应力交替现象,爆炸加载应变率以104 s-1的数量级变化;(2)药包长径比和药量的变化对应变峰值变化幅度影响在爆源近距离处较大,在相对距离大于45后影响较小;(3)长径比大的药包的爆炸能量对介质作用较为分散,有利于提高炸药的能量利用率.     

轴向打孔装药爆炸切断TC4钛合金板的研究

为了探究爆炸切断TC4钛合金板的最佳方式，设计了轴向单孔和轴向双孔两种装药结构。采用AUTODYN软件进行了数值模拟，并结合试验分别对单孔装药和双孔装药优劣性以及装药孔径对爆炸切断效果的影响进行了对比分析。通过计算装药量及运用Mises屈服准则，判断了两种装药结构下4组试验方案中TC4钛合金板的切断及损伤情况，且结合测点振速与加速度变化情况说明了应力波在板内的传播规律。结果表明:爆炸切断能力会随着装药直径的增大而增强，且钛合金板的损伤也随之增大；相较于单孔装药，双孔装药更适用于爆炸切断TC4钛合金板。     

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.……     

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.     

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.