装药量对温压炸药爆炸毁伤威力的影响

为了获得温压炸药装药量对近地空中爆炸的能量输出结构的影响规律,开展了质量为0.5、1.0、2.0 kg的温压炸药近地空爆试验,并使用压力传感器、高速摄像机、红外热成像仪记录了爆炸冲击波和爆炸火球参数。使用TNT超压经验公式对0.5、1.0、2.0 kg装药的空中入射冲击波、地面冲击波的超压峰值进行拟合,建立了冲击波超压峰值衰减规律方程。根据高速摄像机和红外热成像仪的测试结果,建立了基于装药量的爆炸火球直径、火球持续时间和火球温度最高时刻热通量的拟合方程。对比0.5、1.0、2.0 kg装药的爆炸火球图像和温度曲线可以看出：随着装药量的增加,爆炸火球的最高温度、火球尺寸(直径×高度)以及持续时间均有一定的增加,高温区域在火球面积中的占比也有所提升。     

含铝温压炸药的爆炸能量结构研究

为了研究黑索今（RDX）基含铝温压炸药的爆炸能量释放规律及爆炸能量输出结构，对5种含铝温压炸药的爆热和爆速进行了测试，利用绝热式爆热量热计测量了铝粉质量分数为30%的RDX基含铝温压炸药在真空、0.1 MPa氮气、0.1 MPa空气和1.0 MPa氧气环境下的爆炸能量，结合测试数据对试样的爆轰热、爆热和燃烧热进行理论计算。结果表明，RDX基含铝温压炸药的爆速随铝粉含量的增加而线性减小；爆热随铝粉含量的增加呈现先增大后减小的趋势，在铝粉质量分数为40%时，爆热达到最大值。试样在真空、0.1 MPa氮气、0.1 MPa空气、1.0 MPa氧气环境下的爆炸能量逐渐增加，环境压力的增大和气氛环境中氧含量的增加都会提高炸药的爆炸能量，富氧环境下的爆炸能量可以定量地表征炸药的燃烧热。样品的爆轰热占燃烧热的9.8%~26.4%，爆热占燃烧热的34.5%~50.0%，且这两个参数都随铝粉含量的增加而降低。     

温压炸药爆炸冲击波在坑道内的传播规律研究

温压炸药爆炸冲击波对坑道内的人员和设备构成严重威胁。在TNT爆炸试验数据验证的基础上,利用AUTODYN软件建立了炸药堵口爆炸的数值计算模型。基于JWL-Miller能量释放模型计算原理,通过与TNT冲击波的对比,研究了某型温压炸药爆炸冲击波在坑道内的传播特性;通过与空旷地面爆炸冲击波的对比,研究了坑道对温压炸药爆炸冲击波的约束作用。研究结果表明:温压炸药具有更大的破坏威力,温压炸药的超压峰值和正相冲量平均为TNT的1.91倍和1.82倍,其超压和冲量等效TNT当量系数分别为1.94和2.21;坑道对温压炸药冲击波的约束作用明显,其超压峰值和正相冲量平均值分别为空旷地面上的13.55倍和15.21倍。     

RDX/Al含铝炸药水下爆炸实验研究

铝粉含量和周围介质的可压缩性对含铝炸药的爆炸效应有很大影响.通过水下爆炸实验,研究了铝粉含量对RDX/Al含铝炸药水下爆炸冲击波能量的影响以及冲击波特征参数随传播距离的变化关系.结果表明,铝粉在爆轰产物中的二次燃烧反应明显地减缓了水中冲击波后压力的衰减,提高了冲击波的能量和冲量,当铝粉含量为20%时,RDX/Al含铝炸药的冲击波能量达到最大值.确定组分的含铝炸药仍然符合爆炸相似律,无量纲冲击波特征参数与对比距离的函数关系可以拟合为幂函数形式.     

高含铝炸药爆炸过程中的能量分析

在野外静爆实验中,利用高分辨率、高精度冲击波超压系统分别测试了高含铝炸药和TNT的爆炸场冲击波超压,根据试验数据,计算该含铝炸药的爆炸场冲击波超压的TNT当量,利用TNT当量评价该高含铝炸药的威力,用能量反演方法分析该含铝炸药中可燃组分的反应程度和可能的反应模式,计算可得该含铝炸药爆炸反应释放能量的有效利用率为65.41％,为高含铝炸药配方优化设计提供新的研究方法.     

TNT和温压炸药的爆炸火球表面温度对比试验研究

使用红外热成像仪记录了TNT和温压炸药爆炸后的火球表面温度场,得到了2种炸药的爆炸火球表面最高温度、持续时间、火球尺寸和火球温度变化速率等参数,并对温压炸药后燃烧对火球温度的影响进行了分析。结果表明,温压炸药爆炸火球的不同时刻最高温度和持续时间都大于TNT,温压炸药火球体积较大,且更为扁平,温压炸药和TNT爆炸火球的温度变化速率曲线分别呈"V"和"L"型,强烈的后燃烧使得温压炸药爆炸火球温度衰减较慢,持续时间较长。     

含储氢合金炸药的能量研究

通过水下试验和空中爆炸试验研究了RDX基含储氢合金炸药的能量释放,并与含铝炸药进行比较。水下能量的研究发现,在金属粉质量分数为30％时,组分适当的含储氢合金炸药水下爆炸比气泡能和总能量高于相应含铝炸药,含A-30、A-60合金炸药的比气泡能分别比含铝炸药提高9．3％和5．1％,总能量分别提高7．0％和3．0％;空中爆炸研究发现,在相同爆心距处,含储氢合金炸药的爆炸冲击波压力和冲量与含铝炸药相当。试验结果表明：由于储氢合金中的氢元素能够通过燃烧放热和产生水蒸气并促进铝、硼金属的氧化,因此可以提高爆炸的总体能量输出。     

铝粉粒度对RDX基含铝炸药水中爆炸近场特性的影响

为研究铝粉粒度对RDX基含铝炸药水中爆炸近场特性的影响,采用转镜式高速扫描相机对含30％(质量分数)微米铝粉、20％(质量分数)微米铝粉与10％(质量分数)亚微米铝粉的2种RDX基含铝炸药水下近场爆炸过程进行了观察记录,获得了沿装药径向的爆炸冲击波传播轨迹扫描底片。通过对2种含铝炸药水中近场爆炸扫描底片进行判读分析,获取了沿装药径向的爆炸冲击波传播迹线与爆轰产物膨胀迹线,由此分析得出2种含铝炸药爆炸冲击波传播速度、波阵面压力和爆轰产物气泡的膨胀位移等参数的变化规律,并对2种含铝炸药相关参数进行了对比分析。结果表明,在10％(质量分数)微米铝粉替换为亚微米铝粉后,含铝炸药冲击波的初始传播速度及波阵面压力减小且能量衰减速率也降低,冲击波传播距离为40 mm左右时,2种炸药的阵面压力便较为相近,并且在爆轰产物气泡膨胀阶段,由于亚微米铝粉反应较快,其释放的能量导致气泡膨胀速率增长较快。     

含铝炸药近场水下爆炸冲击波的实验及数值模拟

含铝炸药能改善能量的输出结构,增强爆轰产物的做功能力,将其应用于水下爆炸,能显著提高水中兵器的爆炸威力和毁伤能力。基于电测法采用PVDF压力传感器开展含铝炸药RL-F和TNT近场水下爆炸冲击波实验,并采用耦合欧拉-拉格朗日(CEL)法对其进行模拟;通过将仿真结果与实验值及经验值对比,结果表明采用合理的边界条件、计算参数和有限元模型,CEL方法能准确地模拟含铝炸药和TNT近场水下爆炸冲击波的传播过程;含铝炸药近场水下爆炸冲击波压力衰减速率相对于TNT较缓慢。在验证数值模型合理性的基础上,将数值结果拟合得到TNT近场水下爆炸冲击波峰值压力在6倍装药半径内以及含铝炸药峰值压力在一定比例距离范围内的近似回归公式。     

不同组分温压炸药的爆炸冲击波特性

为了更好地运用炸药爆炸的毁伤能力,采用相关实验手段对不同组分温压炸药的冲击波超压、正压作用时间及冲量等反应爆炸冲击波特性的参数进行了研究,并将测得的实验结果与TNT的爆炸冲击波特性进行了对比分析。结果表明,两种温压炸药W-1、W-2的爆炸性能均强于TNT炸药,且由于固液混合相温压炸药W-2中各组分混合得更为均匀,其爆炸性能强于固相温压炸药W-1,可为进一步研究温压炸药毁伤效应提供参考。     

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 ...     

Effect of Oxide Assisted Metal Nanoparticles on Microstructure and Morphology of Gallium oxide Nanowires

Several researches have been reported about the characteristic of β-Ga2O3 nanowires which was synthesized on nickel oxide particle. But indeed, recent researches about synthesis of β-Ga2O3 nanowires on oxide-assisted transition metal are limited to nickel or cobalt oxide catalyst. In this work, Gallium oxide (β-Ga2O3 ) nanowires were synthesized by a simple thermal evaporation method from gallium powder in the range of 700 - 1000℃ using the iron, nickel, copper, cobalt and zinc oxide as a catalyst, respectively. The β-Ga2O3 nanowires with single crystalline without defects were successfully synthesized at the reaction temperature of 850, 900 and 950℃ in all the catalysts. But optimum experimental condition in synthesis of nanowires varied with the kind of catalyst. As increasing synthesis temperature,the morphology of gallium oxide nanowires changed from nanowires to nanorods, and its diameter increased. From these results, we could be proposed that the growth mechanism of β-Ga2O3 nanowires was changed with synthesis temperature of nanowires. Microstructure and morphology of Synthesized nanowire was characterized by HR-TEM, FE-SEM, EDX and XRD.     

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