共查询到18条相似文献,搜索用时 78 毫秒
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用亚微米单质炸药CL-20和亚微米CL-20/配位键合剂-603(LBA-603)混合炸药的撞击感度试验研究了LBA-603对亚微米CL-20/LBA-603体系撞击感度的影响,并对LBA-603在混合炸药中的作用机理进行了探讨.结果表明,由于LBA-603与CL-20分子的-NO2基团形成诱导效应,LBA-603在亚微米CL-20表面形成一层黏附层,对亚微米CL-20起到包覆作用,包覆层具有能量缓冲、吸热、表面修饰的作用;亚微米CL-20/LBA-603混合炸药的撞击感度随LBA-603添加量的增加而降低,与单质炸药亚微米CL-20相比,添加质量分数10%的LBA-603后,混合炸药的特性落高(H50)提高了10.96 cm. 相似文献
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超临界流体增强溶液扩散技术制备纳米CL-20及表征 总被引:4,自引:0,他引:4
采用超临界流体增强溶液扩散技术(SEDS法),以乙酸乙酯为溶剂,在9.0 MPa、40℃及溶液质量分数30%、溶液和反溶剂流速分别为5mL/min、8 kg/h的工艺条件下,制备了纳米六硝基六氮杂异伍兹烷(CL-20).用偏光显微镜与扫描电镜(SEM)、激光粒度分析仪、动态颗粒图像分析仪对细化前后的形貌、粒度、粒度分布和球形度进行表征,用傅里叶红外光谱仪(FT IR)和X射线衍射仪(XRD)对纳米CL-20的晶型进行了表征,测试了其热安定性和撞击感度.结果表明,所得CL 20边缘光滑且趋于球形,粒度均匀(1~2μm),所属晶型为β-型,与原料CL-20相比,晶型转变温度推后了约30℃,而分解峰温提前了6.74℃,撞击感度明显降低. 相似文献
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为了研究粒度级配对CL-20基炸药油墨流变性能的影响,制备了粒径分别为400nm和4μm的CL-20样品,以及7种不同粒度级配的CL-20基炸药油墨;采用博勒飞(CPS)流变仪对炸药油墨进行了黏度测试,得到了相应的流变数据,并计算出非牛顿指数、屈服值和触变指数。结果表明,炸药颗粒的粒度级配对炸药油墨的流变性能有着十分明显的影响;随着粒径为4μm的CL-20含量的增多,炸药油墨表观黏度出现先减小后增大的现象;同时,非牛顿指数出现先增大后减小的现象,屈服值和触变指数总体上呈现先减小后增大的现象;当炸药油墨中粒径分别为400nm和4μm的CL-20质量比为1∶2时,炸药油墨的非牛顿指数为最大值0.41,屈服值和触变指数均达到最小值,分别为26.73和8.74,表明在该粒度级配条件下,炸药油墨具有更好的流变性能。 相似文献
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为了提高六硝基六氮杂异伍兹烷(CL-20)的安全性,采用机械混合法和重结晶法分别制备了CL-20/TATB混合物;通过光学显微镜、扫描电子显微镜(SEM)、X-射线衍射(XRD)、差示扫描量热仪(DSC)、感度测试仪对其形貌、晶型、热稳定性、机械感度进行测试分析。结果表明,机械混合后CL-20表面无明显包覆物,而重结晶混合粒子表面有一层致密的黄色薄膜,同时两种混合物中CL-20的晶型仍为ε型,未发生晶型转变;两种混合物的热分解表观活化能较原料CL-20分别提高了17.3、117.36kJ/mol,热爆炸临界温度分别提高了0.12、3.8℃,重结晶混合粒子的热稳定性明显提高;两种混合物的撞击感度(H50)较原料CL-20分别提高了10.4、54.5cm,摩擦感度的临界载荷分别提高了80、60N,表明重结晶混合粒子的机械感度显著降低。 相似文献
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采用静态与水下声发射法测试了CL-20含量及其粒度级配对NEPE推进剂燃速与压强指数的影响;采用DSC与TG-IR联用研究了CL-20对NEPE推进剂热分解行为的影响。结果表明,随着CL-20质量分数由42%增至50%,推进剂燃速与压强指数上升,燃烧效率提高,表明CL-20氧化能力高于GAP/硝酸酯含能黏合剂体系;随着CL-20/HMX、CL-20/Al质量比增高,推进剂燃速上升,燃烧效率上升;CL-20对推进剂燃速和压强指数的贡献高于HMX;随着CL-20/AP质量比增高,CL-20/AP混合体系分解产物氧化能力降低,燃烧反应速率降低,燃速降低;CL-20粒度级配对NEPE推进剂燃烧行为影响显著,当CL-20的粒径(d50)在5~50μm时,随着细粒度CL-20含量增高,推进剂燃速与燃速压强指数下降;当体系中存在超细粒度CL-20(d50=500nm)时,推进剂燃速与燃速压强指数随着超细粒度CL-20含量的增加而有所增加,4种粒度CL-20对NEPE推进剂燃速的贡献顺序为:粗粒度>中粒度>超细粒度>细粒度。 相似文献
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研究了超临界CO2GAS沉析丙酮溶液中HMX的过程压力、温度、溶液初始浓度和溶液的膨胀速度及影响晶体粒度的因素。结果表明,压力增加,沉析颗粒的平均粒度减小;温度控制沉析晶体的晶型,对颗粒度的影响相对较小,温度增加,沉析平均粒度略有增加;溶液初始浓度对平均粒度的影响相对较大,膨胀速度亦是影响粒度及其分布的一个因素。快速膨胀溶液.并使过饱和度足够大,使过饱和度主要消耗在成核上,可得到颗粒小、分布窄的HMX颗粒。 相似文献
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Leyliane E. Marques Alberth M. C. Costa Murilo C. Crovace Ana C. M. Rodrigues Aluisio A. Cabral 《Journal of the American Ceramic Society》2015,98(3):774-780
In this study, lithium disilicate (LS2) glass samples with different particle sizes ranging from less than 105 to 850 μm were prepared. These specimens were inserted in a Pt‐Rh DSC crucible and heated to 850°C at different rates (? = 0.5–30 K/min) to identify their crystallization peaks. The activation energies for the overall crystallization (E) and the Avrami coefficient (n) were evaluated using different nonisothermal models. Specifically, n was evaluated using the Augis–Benett model and the Ozawa method, and E was evaluated using the Kissinger and Ligero methods. As expected, the coarse particles mainly crystallized in the volume, while surface crystallization was predominant in the samples with particle sizes of less than 350 μm. This result was confirmed through SEM analysis of the double stage heat‐treated samples. In contrast with previous studies, our results demonstrated that the activation energy decreased as the particle size increased. In addition, no clear correlation between the peak intensity (δTp) and the particle size was observed. 相似文献
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采用水热反应法制备了一系列微米级氧化锌粉体。用激光粒度分析仪对合成的氧化锌粉体进行粒度表征;结果表明,采用醋酸锌为锌源,Zn2+/OH-物质的量比为1:10,添加复合表面活性剂为1:1的十二烷基硫酸钠和十二烷基苯磺酸钠,在160℃下,反应时间18h,获得的氧化锌颗粒粒径较小,且分布均匀。 相似文献
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Pocoroba E. Pettersson L.J. Agrell J. Boutonnet M. Jansson K. 《Topics in Catalysis》2001,16(1-4):407-412
In this study, an experimental investigation concerning exhaust gas catalysts for heavy-duty diesel engines fuelled by natural gas or biogas is presented. Miniature monoliths, 2.5 wt% Pd/Al2O3, have been prepared, characterised and tested. Various methods have been used in order to obtain different palladium particle sizes, including incipient wetness and microemulsion technique. Crystallite sizes between 2 and 40 nm were obtained. We observed that the metal particle size influences the activity for methane oxidation. Moreover, the homogeneity of the active material was found to affect the reaction rate. 相似文献
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以甘氨酸水溶液的丙酮溶析结晶为对象,探讨了超声波对结晶过程的影响. 在超声波作用下,结晶过程经历空泡形成、超声波诱导成核、二次成核多个阶段;在不同的阶段施加超声波,或在相同时刻引入超声波但持续不同的时间,都可能影响晶体的粒径大小和分布. 在自然均相成核点之前施加超声波并持续较短时间,使晶核以超声波诱导成核为主时,可获得较大颗粒的晶体;在接近均相成核点处施加超声波,将产生更多的晶核,使晶体平均粒径降低. 在晶体生长过程中继续使用超声波,因超声波的破碎效应,也将降低晶体的平均粒径. 相似文献
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Influence of Particle Size and Soaking Conditions on Rheology and Microstructure of Amorphous Calcium Polyphosphate Hydrogel
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Wei Song Joseph Seta Rachel E. Kast Gregory W. Auner Liang Chen David C. Markel Weiping Ren 《Journal of the American Ceramic Society》2015,98(12):3758-3769
Amorphous calcium polyphosphate (ACPP), an inorganic polymer ceramic, has shown promise as a drug delivery matrix following a repeat gelling protocol. This study described a simple method of preparing ACPP hydrogel in the presence of an excess volume of water. The increased water availability accelerates water molecule ingress and microstructural transformation of ACPP hydrogels. The impact of some experimental settings (soaking time, temperature, stirring, and ACPP particle size) on the physiochemical and rheological natures of ACPP hydrogel were investigated and from which possible hydrogel formation mechanisms were inferred. We believe that the formation of ACPP hydrogel is through the mechanisms of intermolecular ionic interaction and entanglement of polyphosphate chains. The potential application of ACPP hydrogel as a ceramic matrix for sustained drug release warrants further investigation. 相似文献