45m高砖烟囱定向拆除爆破

介绍了定向爆破拆除复杂环境下45m高砖烟囱工程实例。通过适当地提高爆破切口高度,并采取加固爆破切口以下的烟囱壁等措施,解决了无烟囱倒塌足够长度和烟囱后坐的技术问题。同时选择了合理的爆破参数和有效的安全防护措施,使爆破取得了圆满成功。     

180m高钢筋混凝土烟囱三段单向控制爆破拆除

对复杂环境下180m高钢筋混凝土烟囱,采用三段单向分次控制爆破拆除。采用复式梯形爆破切口,确保烟囱倒塌方向;铺设黄土缓冲垫层和个体特殊防护措施,有效地控制烟囱倒塌触地振动;采用刚性和柔性复合式措施防控爆破飞石;采用高空吊篮法进行高空爆破切口施工。爆破后,烟囱倒塌方向准确,周边建筑物和设施安然无恙,取得了良好的爆破效果,达到了安全、精细和快速爆破拆除的目的,为以后类似爆破工程提供参考。     

180m高钢筋混凝土烟囱三段单向控制爆破拆除

对复杂环境下180m高钢筋混凝土烟囱,采用三段单向分次控制爆破拆除。采用复式梯形爆破切口,确保烟囱倒塌方向;铺设黄土缓冲垫层和个体特殊防护措施,有效地控制烟囱倒塌触地振动;采用刚性和柔性复合式措施防控爆破飞石;采用高空吊篮法进行高空爆破切口施工。爆破后,烟囱倒塌方向准确,周边建筑物和设施安然无恙,取得了良好的爆破效果,达到了安全、精细和快速爆破拆除的目的,为以后类似爆破工程提供参考。     

复杂环境下砖烟囱爆破拆除

介绍了用定向爆破拆除复杂环境下45 m高砖烟囱.根据周围的环境和该烟囱本身的结构特点,选择了合理的爆破切口和爆破参数,以及烟囱爆破的安全防护措施.烟囱实施爆破后,按预定方向安全倒塌.     

复杂环境下结构体破损的砖烟囱爆破拆除

介绍了用定向爆破拆除复杂环境下结构体破损的砖烟囱.为防止烟囱在爆破时发生后座和散架,确保烟囱在倒塌过程中不发生偏移,根据烟囱的周围环境和结构特点,选择了合理的爆破切口长度,对破损的支撑体部分采取了加固措施,对爆破切口采用对称微差爆破,取得了良好的爆破效果.     

复杂环境厚壁砖混烟囱拆除的精准定向控制爆破

根据砖混结构烟囱的特点和复杂环境,合理选择烟囱拆除爆破的倒塌方向,确定爆破切口为近等腰梯形,并在切口底部采用控制爆破方式预先开凿定向窗,以实现厚壁砖混结构烟囱拆除的精准定向爆破。实施砖混结构烟囱定向窗的爆破开凿,降低了劳动强度,缩短了开凿时间,提高了开凿准确性。采用竹笆近体防护措施和排栅远体防护措施,防止切口爆破飞散物及落地飞溅的危害,同时采用沙包减振堤降低落地冲击振动,控制了振动危害,取得了预期的爆破效果。对类似工程有较好的参考价值。     

210m高烟囱分次爆破

介绍了210m高钢筋混凝土烟囱分次爆破拆除的成功案例.给出了2次爆破方案的切口设计,爆破参数选择,施工方法和防护措施.这是特高烟囱分次爆破在国内的首次尝试,为此类烟囱爆破提供了成功的经验.     

高90m钢筋混凝土烟囱的定向爆破拆除

介绍了高90m钢筋混凝土烟囱的定向爆破拆除,重点论述了爆破切口方案设计、爆破参数选取和安全防护措施及爆破效果,确保了周边建筑物的安全。可为此类烟囱的爆破拆除提供参考。     

30m高砖烟囱单向折叠爆破拆除

介绍了复杂条件下的砖烟囱单向折叠爆破拆除。阐述了在倾倒空间不足情况下,为保证烟囱准确倾倒,确定了两段不同段高,单向折叠爆破的技术方案。同时介绍了爆破方案的选择和爆破切口的设计,通过两切口的起爆时差,减弱上下两节烟囱的相互影响,并结合爆破网路设计和有效的安全防护措施,较好地实现了爆破拆除。     

高90m钢筋混凝土烟囱的定向爆破拆除

介绍了高90m钢筋混凝土烟囱的定向爆破拆除,重点论述了爆破切口方案设计、爆破参数选取和安全防护措施及爆破效果,确保了周边建筑物的安全。可为此类烟囱的爆破拆除提供参考。     

乳化炸药密度对其冲击波感度的影响

乳化炸药的冲击波感度是评价乳化炸药安全性的重要指标。本研究采用隔板试验法测定了不同密度乳化炸药的冲击波感度 ,并分析了乳化炸药的密度对其冲击波感度的影响规律。研究表明 ,在一定范围内 ,随着乳化炸药密度的增大 ,其起爆所需的冲击波强度逐步减小 ,换言之 ,乳化炸药随其密度的增大变得敏感     

未反应乳化炸药冲击Hugoniot关系的测试

未反应乳化炸药冲击Hugoniot关系是乳化炸药的基本性能参数 ,它不仅是研究乳化炸药冲击引爆机理和确定其反应速率函数必不可少的数据 ,也是研究乳化炸药中冲击波演变为爆轰波的过程及进行乳化炸药爆轰数值模拟的重要参数。本文利用设计的新型测试装置和建立的测试系统 ,较好地测试了未反应乳化炸药冲击Hugoniot关系。     

Prediction of shock sensitivity of explosives based on small-scale gap test

A new method is described to predict shock sensitivity of C(a)H(b)N(c)O(d) explosives without using any experimental data. It can determine shock sensitivity based on small-scale gap test as the pressure required to initiate material pressed to 90%, 95% and 98% of theoretical maximum density. Three essential parameters would be needed in the new scheme which contain a+b/2-d, the existence of alpha-C-H linkage in nitroaromatic compounds or NNO(2) functional group and difference of the number of amino and nitro groups attached to aromatic ring. Predicted shock sensitivities in some well-known explosives have a root mean square (rms) deviation of 3.97, 4.02 and 5.89kbar of experiment to initiate pressure of material pressed to 90%, 95% and 98% of theoretical maximum density, respectively.     

装药条件对B炸药落锤撞击响应的影响研究？

采用自行研制的药柱撞击感度试验装置,对B炸药在不同装药尺寸、装药密度和装药状态下的撞击响应进行了试验研究,探讨了不同装药条件对其落锤撞击响应的影响规律,分析了产生原因。结果表明：对于B炸药,在相同直径条件下,起爆阈值随着药柱厚度的增大而增大;接近理论密度时,撞击感度对装药密度的变化并不敏感;撞击刺激下不同物态的响应敏感性有显著差异,药粉感度远大于药柱感度。     

管道内水雾对冲击波衰减作用的实验研究

采用直径200 mm立式激波管,进行了管道内水雾对冲击波衰减作用的实验研究.实验结果表明,冲击波衰减率与水雾密度、雾滴直径和雾区厚度有关.相同雾滴直径时,水雾密度越大,冲击波的衰减率越大相同水雾密度时,水雾的雾滴直径越小,冲击波的衰减率越大.     

Diffraction characteristics with various polarizations of overlapping holographic gratings in a uniaxial crystal

By the Riemann method, a coupled wave model is derived for the ordinary-to-ordinary (OO) and extraordinary-to-extraordinary (EE) Bragg diffraction of a Gaussian beam by overlapping holographic gratings in a uniaxial crystal. The computer simulation is used to discuss the relations among the diffraction efficiency, the index modulation, the wavelength sensitivity, the angular sensitivity, and the the widths of the recording and reading beams. The characteristics of EE and OO diffraction in a uniaxial crystal are found to be remarkably different. The simulation shows that EE diffraction may exhibit far higher diffraction efficiency than does OO diffraction for very low index modulation with the same hologram size, for example, nearly 90% when the size is 8.2 x 10(-5).     

Shock compaction of silicon carbide powder

A series of shock compaction experiments on SiC powder were carried out over a wide range of shock pressures and shock temperatures up to 30 GPa and 3400 K. Large changes in some physical properties and a variety of unique microstructures were observed in the shock-treated samples with changes in impact conditions. For an iron plate impactor, the optimum impact condition, which depends on the initial density, is 2.5 km sec^–1 for 70% initial density and 2.0 km sec^–1 for 50%. The best-sintered compact of SiC with 97% density and micro-Vicker's hardness of 2700 kg mm^–2 was obtained under optimum conditions. Good compacts with high relative density and high strength exhibit the disruptive effects of the shock wave, which are indicated by microstrain increase and crystallite size reduction. The skin model is presented here in order to estimate the heterogeneous shock state which is realized under and after shock loading of the initial powder aggregates.     

乳化炸药稳定性及其破乳机理研究

为研究乳化炸药储存稳定性及其破乳机理,通过乳胶基质储存试验,采用显微照相法观测乳化炸药储存过程中乳状液的变化,采用甲醛还原法测定乳胶基质析晶量随时间的变化,并对硝酸铵的结晶进行理论分析。结果表明,乳化剂是影响乳化炸药储存稳定性的关键因素,提出了炸药乳状液破乳机理;析晶量随时间的关系也表明乳化剂是影响乳胶基质存储稳定性的重要因素。认为使用高分子乳化剂增强油膜厚度和抑制硝酸铵析晶是提高乳化炸药稳定性的有效方法,同时将研究结果与工业生产实际相结合,对得到的结论进行了检验。通过本文的研究,达到了深入认识影响乳化炸药储存稳定性的因素以及破乳机理的目的。     

传爆药冲击波感度试验方法的简化研究

尝试了一种用压装A-IX-I(RDX与钝感剂质量比为95︰5)药柱替代纯RDX作为施主药柱进行冲击波感度试验( SSGT)的方法,通过零隔板试验,检验了施主药柱的爆炸能量输出性能。所得施主药柱的平均质量为1195.5 mg,相对误差0.495％;鉴定块的平均凹痕深度1.769 mm,相对误差0.96％,说明压装法得到的施主药柱性能较好。利用该方法研究了JH-14传爆药经过高温加速老化前后的冲击波感度,结果显示,老化后的样品冲击波感度具有增加的趋势。     

Flexible electronic eardrum

Flexible mechanosensors with a high sensitivity and fast response speed may advance the wearable and implantable applications of healthcare devices,such as real-time heart rate,pulse,and respiration monitoring.In this paper,we introduce a novel flexible electronic eardrum (EE) based on single-walled carbon nanotubes,polyethylene,and polydimethylsiloxane with micro-structured pyramid arrays.The EE device shows a high sensitivity,high signal-to-noise ratio (approximately 55 dB),and fast response time (76.9 μs) in detecting and recording sound within a frequency domain of 20-13,000 Hz.The mechanism for sound detection is investigated and the sensitivity is determined using the micro-structure,thickness,and strain state.We also demonstrated that the device is able to distinguish human voices.This unprecedented performance of the flexible electronic eardrum has implications for many applications such as implantable acoustical bioelectronics and personal voice recognition.