中型浮动冲击平台试验爆源定位方法研究

中型浮动冲击平台海上试验受环境影响因素多、实施难度大,水下爆源爆炸作为中型浮动冲击平台的冲击载荷,试验中对爆源的高精度定位具有重要意义。该文通过对比分析水下爆源定位的各种技术,总结其特点和应用条件,并针对浮动冲击平台水下爆炸试验时爆源受海况影响情况进行研究,设计适用于浮动冲击平台海上试验爆源定位的高精度机械定位方法。计算结果表明该方案简洁、高效,定位精度高,生产布置成本低。该研究结果可为中型浮动冲击平台试验成功实施提供参考,并且也能够适用于其他水下爆炸试验的爆源定位。     

无线量测系统在大当量静爆测试中的应用

大当量静爆威力试验中待测物理参数多、传感器布设区域广、人员安全距离远,给引线电测系统和存储测试系统带来诸多困难。该文研制基于WI-FI的爆炸效应无线量测系统,由数据采集仪、无线组网设备等组成。数据采集仪具备信号调理、数据采集和存储、无线通信、高精度同步等功能;无线组网设备支持802.11n/ac协议,发射功率高,内置高增益定向天线。通过大当量静爆威力试验验证系统的可靠性。整个系统能够实现远程无线管理、多设备高精度同步采样、数据高速率无线传输、大范围分布式布设,可提高静爆威力测试效率。     

舰船缩比模型水下非接触爆炸载荷测量与分析

合理设置舰船缩比模型海上毁伤试验工况,有效考核舰船抗冲击性能和兵器毁伤效能的同时,减小舰船模型的毁伤程度。通过测量和分析模型在不同装药量和不同爆炸初始深度的爆炸载荷试验数据,确定爆源布放深度与表面反射及海底边界条件等对冲击波压力和气泡脉动影响的关系,为分析舰船冲击环境及水下非接触爆炸数值仿真数据输入提供思路。     

水下非接触爆炸抗冲击缓冲平台性能研究

为有效测量水下非接触爆炸试验中舰船及设备的抗冲击性能,保护测量设备在冲击环境下能够安全使用,根据设备冲击输入设计和研制了抗冲击缓冲平台,以减小舰船设备在水下非接触爆炸冲击作用下受到的冲击.按照要求的缓冲平台设计载荷和缓冲效率,进行缓冲器刚度的选择和结构设计,利用仿真运算设计工况.经海上实爆冲击试验验证,该缓冲平台能有效...     

爆炸事故中爆炸药量和爆源的确定

按照建筑物破坏等级划分,分析了如何根据建筑物及其标志物(梁、柱和墙)的破坏推导爆源位置和药量的计算方法,提出了利用不在同一直线的3个标志物的对比距离值估算爆源药量和相对位置的方法,并给出一算例,介绍其计算过程和计算方法.     

峒室爆破计算机辅助设计软件的研究和开发

本文对峒室爆破设计手段的计算机化进行了初步探讨，并给出了地形信息的快速采集和自动处理，多层多排装药的自动布设，爆破漏斗的形成与爆堆的设计等处理方法，为爆破工程设计的现代化提供一种可行的设计思路。     

爆坑尺寸的计算与试验研究

为了研究爆坑尺寸与爆炸位置和爆炸当量的函数关系,归纳了国内外炸药近地面爆炸成坑效应研究情况,分析了爆炸形成的爆坑尺寸计算公式和适用条件,并将野外爆炸试验的数据与计算公式及相关文献给出的试验结果进行对比,分析了结果偏差所产生的原因。结果表明:爆坑尺寸计算公式需考虑爆炸高度的影响,还应结合一定次数的场地试验来得到不同场地上爆炸成坑尺寸与爆炸当量和爆炸高度的函数关系,并且考虑炸药种类;同时爆坑试验结果离散性大,爆坑尺寸计算公式应采用上下限的形式。     

爆振对衬砌损伤特性影响的室内试验研究

本文根据一隧洞施工现场的实测爆振波特性，就爆振波对隧洞衬砌的浇筑时间、衬砌混凝土受振后的强度降低问题进行了室内爆振模拟试验，并应用损伤力学理论对试验结果作出了合理解释；对工程上所关心的安全爆速、衬砌的安全距离及合理衬砌时间等重要参数都给出了明确解答。     

爆振对衬砌损伤特性影响的室内试验研究

本文根据一隧洞施工现场的实测爆振波特性，就爆振波对隧洞衬砌的浇筑时间、衬砌混凝土受振后的强度降低问题进行了室内爆振模拟试验，并应用损伤力学理论对试验结果作出了合理解释；对工程上所关心的安全爆速、衬砌的安全距离及合理衬砌时间等重要参数都给出了明确解答。     

水下爆炸试验爆源定位方法研究

为实现水下爆炸试验爆源在爆炸时刻相对于水面目标舰艇的定位测量,提出一种最小误差逼近的遍历搜索定位方法。该方法通过在目标舰艇上安装一定数量的爆炸载荷压力测量传感器,根据获取的爆炸载荷数据中冲击波传播的时间信息和冲击波压力峰值,实现爆源定位计算。小当量的水下爆炸试验结果表明:4个有效爆炸载荷测点数据可以实现爆源炸点定位计算,增加有效测点数量,可以提高爆源定位精度。     

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.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

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.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

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.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

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.