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91.
设计并制备了两种不同配方的新型复合式反应破片,并进行了该反应破片对装有柴油油箱的毁伤试验。复合式反应破片由壳体、裸反应破片、顶盖组成。裸反应破片采用铝粉和聚四氟乙烯、钛粉和聚四氟乙烯两种材料配方真空高温烧结制成。试验利用12.7 mm弹道枪发射复合式反应破片,并用高速摄影仪记录破片对油箱的毁伤过程。两种配方的复合式反应破片均能穿透6 mm厚油箱壁,并具有明显的引燃效果。试验结果表明,与惰性破片相比,复合式反应破片兼有侵彻能力和引燃纵火能力。 相似文献
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We introduce a simple model based on the Moran process with network dynamics. Using pair approximation, the cooperation frequencies at equilibrium states are deduced for general interactions. Three usual social dilemmas are discussed in the framework of our model. It is found that they all have a phase transition at the same value of cost-to-benefit ratio. For the prisoner's dilemma game, notably it is exactly the simple rule reported in the literature [Nature 441 (2006) 502]. In our model, the simple rule results from the parent-offspring link. Thus the basic mechanism for cooperation enhancement in network reciprocity is in line with the Hamilton rule of kin selection. Our simulations verify the analysis obtained from pair approximation. 相似文献
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微波消解-电感耦合等离子体质谱测定大气颗粒物中痕量稀土元素 总被引:10,自引:0,他引:10
研究了电感耦合等离子体质谱(ICP-MS)测定大气颗粒物中痕量稀土元素(REEs)的分析方法。在微波条件下,采用HNO3 + H2O2(3 + 1)混合介质能快速而有效地分解颗粒物样品。详细讨论了测定稀土元素的质谱干扰。通过分析不同粒径颗粒物中稀土元素的含量,初步探讨了大气颗粒物中稀土元素的分布规律。结果表明:颗粒物试样的粒径越小,稀土元素的含量越高。分析方法的检出限为0.7~2.8pg/mL,用于大气颗粒物国际标样(SRM 1648)中稀土元素分析,结果与推荐值有良好的一致性。 相似文献
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GAO Shengli CHEN Sanping JIAO Baojuan SHUAI Qi & SHI Qizhen Department of Chemistry Shaanxi Key Laboratory of Physico-lnorganic Chemistry Northwest University Xi''''an China 《中国科学B辑(英文版)》2005,48(Z1)
The enthalpy change of formation of the reaction of hydrous dysprosium chloride with ammonium pyrrolidinedithiocarbamate (APDC) and 1,10-phenanthroline (o-phen·H2O) in absolute ethanol at 298.15 K has been determined as (-16.12±0.05) kJ·mol-1 by a microcalor-meter. Thermodynamic parameters (the activation enthalpy, the activation entropy and the activation free energy), rate constant and kinetics parameters (the apparent activation energy, the pre-exponential constant and the reaction order) of the reaction have also been calculated. The enthalpy change of the solid-phase reaction at 298.15 K has been obtained as (53.59±0.29) kJ·mol-1 by a thermochemistry cycle. The values of the enthalpy change of formation both in liquid-phase and solid-phase reaction indicated that the complex could only be synthesized in liquid-phase reaction. 相似文献
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Loulu is a traditional Chinese medicine which has obvious activities in anti-peroxidantion, anti-atherosclofosis and immunopotentintion. The pharmacological activities of ecdysterone in Loulu are in good agreement with the curative effects of Loulu. Therefore, the quantitative determination of ecdysterone in Loulu will be helpful in further researching the medicinal mechanism. The components of Loulu are very complex. Many overlapping peaks from interference will be present in chromatograms if the sample is directly determined by HPLC. So it is very important to search for a simple, rapid and effective sample pretreatment technique. Flow injection analysis, as an effective sample treatment technique, has applied in many fields. In this work, a flow injection micro-column system for the sample pretreatment coupling HPLC was proposed. Ecdysterone in.Loulu was pre-separated with the designed system, and then determined by HPLC. The separation performance, the influence factors of the pre-separation and the operation parameters of the HPLC have investigated in detail. The experimental results demonstrated that the present system is simple, efficient and no pollution. The method was applied to the determination of ecdysterone in real samples. 相似文献