花岗岩的黑火药爆炸切割技术

本文介绍了爆炸切割与光面爆破的区别；系统阐述了石材切割技术方案选择、黑火药爆炸切割参数的确定、切割工艺、起爆技术及切割实例。     

大巴车玻璃柔性聚能切割技术的应用研究

将柔性聚能切割技术应用于大巴车玻璃切割,以满足复杂环境下对大巴车救援的要求.针对大巴车的功能特点设计了一种大巴车玻璃爆炸切割装置,主要从爆炸切割装置的结构、切割索结构、炸药选择和防护装置等方面进行了研究.通过模拟切割试验、安全性试验验证,采用柔性聚能切割技术研制的大巴车玻璃爆炸切割装置可以在保证车内人员安全的条件下实现对大巴车玻璃的切割,且使用安全、方便,能够满足反恐突击作战要求.     

大巴车玻璃柔性聚能切割技术的应用研究

将柔性聚能切割技术应用于大巴车玻璃切割,以满足复杂环境下对大巴车救援的要求。针对大巴车的功能特点设计了一种大巴车玻璃爆炸切割装置,主要从爆炸切割装置的结构、切割索结构、炸药选择和防护装置等方面进行了研究。通过模拟切割试验、安全性试验验证,采用柔性聚能切割技术研制的大巴车玻璃爆炸切割装置可以在保证车内人员安全的条件下实现对大巴车玻璃的切割,且使用安全、方便,能够满足反恐突击作战要求。     

线型聚能爆炸切割技术的工程应用

聚能爆炸切割是近年来出现的一种先进技术。本文叙述了聚能爆炸切割的线型空心装药和爆炸相似律,并着重介绍了这种技术在打捞和拆船工程上的应用特点。实践证明,聚能爆炸切割技术具有经济效益高,施工安全和操作简单等特点。     

爆炸切割在水下工程中的应用

本文探讨用爆破技术在水下工程中爆炸切割钢板(管)之类抗拉力比岩石大的韧性材料构件施工新技术。1 水下爆炸切割法的原理水下爆炸切割法就是在水下利用炸药的爆炸作用把被切割对象按预定要求进行切割施工的方法。其工作原理是:通过炸药在爆炸的一瞬间所产生出来的强大的爆破能量,迅速地变为具有切割力的射流式束状破坏动     

爆炸切割在水下工程中的应用

本文探讨用爆破技术在水下工程中爆炸切割钢板(管)之类抗拉力比岩石大的韧性材料构件施工新技术。水下爆炸切割法的原理水下爆炸切割法就是在水下利用炸药的爆炸作用把被切割对象按预定要求进行切割施工的方法。其工作原理是:通过炸药在爆炸的一瞬间所产生出来的强大的爆破能量,迅速地变为具有切割力的射流式束状破坏动     

水下爆炸切割钢板的试验研究

以切割钢板的深度为目标,对水下爆炸聚能切割器的参数进行了优化设计,研究了水下爆炸切割钢板的爆炸工艺,获得了装药性质、装药高度、炸高、药型罩厚度、装药长度和水介质对爆炸聚能切割器切割钢板深度的影响规律,并采用最小二乘法对某些影响聚能切割钢板深度的因素进行了回归.研究结果表明,在实际水下爆炸切割中,应根据切割的要求,从聚能切割器加工安全性、切割效果和经济效益等方面综合优化聚能切割器的参数.     

线型聚能切割爆破的理论研究

通过对线型聚能爆炸切割器的高速碰撞问题建立不可压缩流体模型,推导获得了爆炸切割射流参数的解析解,将之与聚能破甲理论结合,详细分析了爆炸切割器的设计要点。文中系统地说明了线型聚能切割爆破的切割深度、切割器设计炸高、聚能罩最佳顶角、聚能罩材料等与切割器参数的关系。进而利用所建立的流体聚能切割理论模型,对聚能切割器顶部同步起爆、沿顶部线性和外表面高速起爆问题都进行了理论解析和研究,分析了各种起爆方式的切割射流与破甲特点,以及对切割器参数设计的影响等。还根据滑移爆轰、等容爆轰、正向起爆对飞片驱动能力的对比分析,结合所建立的聚能切割理论,说明了高速起爆可以提高切割能力的原理。通过分析对比各种装药质量比下飞片的爆炸能量利用率,指出了爆炸切割器设计药量的选取原则。对于复杂的三维爆炸聚能切割理论问题,笔者尽量采用简洁直观的数学方法进行理论推导,着重对物理概念的阐述与分析,以求对线型聚能爆破的理论和技术发展起到促进作用。     

线型聚能切割爆破的理论研究

通过对线型聚能爆炸切割器的高速碰撞问题建立不可压缩流体模型,推导获得了爆炸切割射流参数的解析解,将之与聚能破甲理论结合,详细分析了爆炸切割器的设计要点。文中系统地说明了线型聚能切割爆破的切割深度、切割器设计炸高、聚能罩最佳顶角、聚能罩材料等与切割器参数的关系。进而利用所建立的流体聚能切割理论模型,对聚能切割器顶部同步起爆、沿顶部线性和外表面高速起爆问题都进行了理论解析和研究,分析了各种起爆方式的切割射流与破甲特点,以及对切割器参数设计的影响等。还根据滑移爆轰、等容爆轰、正向起爆对飞片驱动能力的对比分析,结合所建立的聚能切割理论,说明了高速起爆可以提高切割能力的原理。通过分析对比各种装药质量比下飞片的爆炸能量利用率,指出了爆炸切割器设计药量的选取原则。对于复杂的三维爆炸聚能切割理论问题,笔者尽量采用简洁直观的数学方法进行理论推导,着重对物理概念的阐述与分析,以求对线型聚能爆破的理论和技术发展起到促进作用。     

爆炸切割

本文介绍了套筒式切割器从外部进行爆炸切割钢管的方法,绘出了切割两种不同材质钢管的切割特性曲线,讨论了爆炸切割过程产生的爆轰波、碎片流对管体及周围环境的影响。     

Properties,applications and manufacture of wear-resistant hard material coatings for tools

Wear processes during machining with cemented carbides and the effect of coatings on wear and on toughness are described. The requirements for coatings relating to optimum tool life are reviewed. Recently developed multilayer coatings with and without ceramic layers are described and examples for improvements in the tool lifetime are given. Additionally, some examples for the application of coatings for milling and chipless forming are presented.The wear-reducing effect of coatings on steel tools is described and possibilities for applications of steel tools coated using chemical vapour deposition (CVD) are elucidated. A number of examples for coated cutting and chipless forming steel tools are described.Finally, useful processes for the coating production are considered. A comparison between physical vapour deposition and CVD processes with respect to the coating temperature, the consistency and the adhesion of the coating is presented. The CVD process for economic production is considered and a suitable coating unit is outlined.     

Intracellular Labeling with Extrinsic Probes: Delivery Strategies and Applications

Extrinsic probes have outstanding properties for intracellular labeling to visualize dynamic processes in and of living cells, both in vitro and in vivo. Since extrinsic probes are in many cases cell‐impermeable, different biochemical, and physical approaches have been used to break the cell membrane barrier for direct delivery into the cytoplasm. In this Review, these intracellular delivery strategies are discussed, briefly explaining the mechanisms and how they are used for live‐cell labeling applications. Methods that are discussed include three biochemical agents that are used for this purpose—purpose‐different nanocarriers, cell penetrating peptides and the pore‐foraming bacterial toxin streptolysin O. Most successful intracellular label delivery methods are, however, based on physical principles to permeabilize the membrane and include electroporation, laser‐induced photoporation, micro‐ and nanoinjection, nanoneedles or nanostraws, microfluidics, and nanomachines. The strengths and weaknesses of each strategy are discussed with a systematic comparison provided. Finally, the extrinsic probes that are reported for intracellular labeling so‐far are summarized, together with the delivery strategies that are used and their performance. This combined information should provide for a useful guide for choosing the most suitable delivery method for the desired probes.     

Effective properties of platelet reinforced piezocomposites

Simple algebraic formulae are derived for estimates of the effective thermo-electroelastic moduli of multiphase platelet reinforced composites with the self-consistent and Mori-Tanaka methods. Specific results are given for the effective elastic, piezoelectric and dielectric constants, as well as the thermal stress tensor and pyroelectric constant. The platelets are modeled as very thin oblate spheroids in which the edge effects caused by the sharp corners are taken to be negligible. The results are formulated with the help of a polarization tensor for a piezoelectric platelet inclusion. It is shown that, although the two methods are different in nature, their estimates of the thermoelectroelastic moduli are exactly the same. When the piezoelectric coupling is absent, the results exactly reduce to those for uncoupled elasticity. Moreover, they exhibit the correct behavior in the low and high concentration limits. A number of exact results for a platelet inclusion are also established.     

Optimal Projective Three-Level Designs for Factor Screening and Interaction Detection

Orthogonal arrays (OAs) are widely used in industrial experiments for factor screening. Suppose that only a few of the factors in the experiments turn out to be important. An OA can be used not only for screening factors, but also for detecting interactions among a subset of active factors. In this article a set of optimality criteria is proposed to assess the performance of designs for factor screening, projection, and interaction detection, and a three-step approach is proposed to search for optimal designs. Combinatorial and algorithmic construction methods are proposed for generating new designs. Permutations of levels are used for improving the eligibility and estimation efficiency of the projected designs. The techniques are then applied to search for best three-level designs with 18 and 27 runs. Many new, efficient, and practically useful nonregular designs are found and their properties are discussed.     

Sustainability and recycle–reuse in process systems

We have only one planet in which to live. Because of accelerating use of limited natural resources, its attendant environmental degradation, and societal inequity that has resulted among groups of people as well as that which will result between present and future generations, we generally recognize that the current development patterns are not sustainable for the long term. This realization calls for satisfying our needs by judiciously using renewable resources, recycling wastes and end-of-life products for beneficial uses, and reversing environmental degradation in some areas and minimizing environmental impacts in others. As new scientific and technological innovations are exploited to implement these goals, tools and methods are needed to ascertain that the direction of economic development for meeting increasing standard of living is protective of human life and ecology. Countries that are economically developed, and therefore wealthy, are in a better position to protect the environment than are the developing countries. This situation calls for technologies that are not only benign but also affordable for the developing world. This is the grand challenge of this century. Some ideas on the elements of this grand challenge that are relevant to the practice of chemistry and engineering are discussed here.     

Consistent mapping of common cause failure rates and alpha factors

The problem addressed is how to combine event experience data from multiple source plants to estimate common cause failure (CCF) rates for a target plant. Alternative models are considered for transforming CCF parameters from systems with different numbers of similar components to obtain CCF-rates for a specific group of components. Two sets of rules are reviewed and compared for transforming rates and assessment uncertainties from larger to smaller systems, i.e. mapping down. Mapping down equations are presented also for the alpha-factors and for the variances of CCF rates. Consistent rules are developed for mapping up CCF-rates and uncertainties from smaller to larger systems. These mapping up rules are not limited to a binomial CCF model. It is shown how consistency requirements set certain limits to possible parametric values. Empirical alpha factors are used to estimate robust mapping parameters, and mapping up equations are derived for alpha factors as well. An assessment uncertainty procedure is presented for treating incomplete or vague information when estimating CCF-rates. Numerical studies illustrate mapping rules and procedures. Recommendations are made for practical applications.     

The Green's Function for the Two-Dimensional Helmholtz Equation in Periodic Domains

Analytical techniques are described for transforming the Green's function for the two-dimensional Helmholtz equation in periodic domains from the slowly convergent representation as a series of images into forms more suitable for computation. In particular methods derived from Kummer's transformation are described, and integral representations, lattice sums and the use of Ewald's method are discussed. Green's functions suitable for problems in parallel-plate acoustic waveguides are also considered and numerical results comparing the accuracy of the various methods are presented.     

Nonlocally related PDE systems for one-dimensional nonlinear elastodynamics

Complete dynamical PDE systems of one-dimensional nonlinear elasticity satisfying the principle of material frame indifference are derived in Eulerian and Lagrangian formulations. These systems are considered within the framework of equivalent nonlocally related PDE systems. Consequently, a direct relation between the Euler and Lagrange systems is obtained. Moreover, other equivalent PDE systems nonlocally related to both of these familiar systems are obtained. Point symmetries of three of these nonlocally related PDE systems of nonlinear elasticity are classified with respect to constitutive and loading functions. Consequently, new symmetries are computed that are: nonlocal for the Euler system and local for the Lagrange system; local for the Euler system and nonlocal for the Lagrange system; nonlocal for both the Euler and Lagrange systems. For realistic constitutive functions and boundary conditions, new dynamical solutions are constructed for the Euler system that only arise as symmetry reductions from invariance under nonlocal symmetries.     

浅议标准化知识体系及其人才培养模式

本文从标准化人才供给与需求的视角分析了标准化知识体系,标准化知识体系的基础是工程知识和经济管理知识,在此基础上构建标准化体系。标准化知识体系由标准化知识、计量知识、认可知识、认证知识和质量管理知识构成。分析了标准化知识体系的核心内容,给出了标准化人才的6种培养模式,这6种培养模式分为普通型和专业型人才培养模式。