共查询到19条相似文献,搜索用时 78 毫秒
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为了获得雷管延期药延期精度的影响因素,改变延期药中的硅粉粒度以及延期体的切长后测得单位秒量并进行分析,结果表明:切长较小的延期体单位秒量总趋势上相对较大,可能与延期体的前期燃烧速度未达到相对稳定有关;延期体中硅粉的粒度越小,延期体的单位秒量越低,另外延期体中硅粉的粒度越小,延期体的单位秒量精度越好,其有利于提高雷管的延期精度。 相似文献
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为了探究硅系延期药延期精度影响因素,通过对硅系延期药基础配方设计、铅丹和硅粉的粒径以及硫化锑含量等方面进行分析。结果表明:合理的微负氧平衡硅系延期药配方,燃速稳定,生产的气体少,延期精度较高;一定范围内硅粉粒径越大,硅系延期药燃烧时间越长,精度越差;一定范围内随着硫化锑含量增加,硅系延期药燃速越低。通过合理的配方设计,调节硅粉粒径和硫化锑加入量可以提高延期药延期精度。 相似文献
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文章针对我国延期雷管秒量精度低的问题进行了分析。从延期药在制备过程中及在使用过程中两个方面浅析了影响延期精度的主要因素,包括延期药的纯度和粒度、密度、装药结构、外界环境条件和点火方式的影响等。为延期药的生产和使用提供了一些理论依据。 相似文献
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为实现硼系延期药的线性和延期网络的构筑,并研究药线形态下的延期性能,以硼、氧化铜为延期药主体装药,F2602橡胶为黏结剂,选择N,N-二甲基甲酰胺(DMF)为溶剂,设计了适用于微笔直写工艺的油墨配方,采用微笔直写工艺对不同硼/氧化铜油墨配方进行直写成型,并设计了简单的延期网络。使用流变仪测试了油墨的动态黏度,通过高速摄影技术测试了延期药线的线性燃速,并借助扫描电镜、X射线衍射装置表征了固体反应产物的形貌和组成。结果表明,借助微笔直写技术制备的定制化延期药线打印精度高,厚度控制在(0.90±0.03)mm,燃速的最大相对误差为5.8%,可实现6~20mm/s燃速范围内的精准调控;当硼质量分数5%时,燃速可达20.96mm/s;当硼质量分数为10%~30%时,燃速先从11.76mm/s平缓上升至12.91mm/s左右。之后,燃速随着硼含量的增加急速下降至6.78mm/s;当硼质量分数为25%时,硼/氧化铜延期药线可在列间距大于5mm的延期网络中稳定燃烧。对硼/氧化铜的燃烧产物进行XRD分析说明,硼与氧化铜在硼质量分数为5%时燃烧生成Cu2O和Cu,随着硼含量的升高,反... 相似文献
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采用分次、定量、定压装填微气体单芯延期体,测定压药压强与装药密度以及装药密度与燃速及燃速相对极差的关系。得出在压药压强为50-650 MPa范围内,对应装药密度变化为2.73-3.51 g/cm,同一压强下密度波动小;在密度为2.73-3.51 g/cm3时,对应燃速变化为8.9-17.1cm/s,燃速相对极差变化为49%-3.6%。在装药密度≤3.1 g/cm3时,燃速相对极差随密度变化较快,装药密度>3.1 g/cm3时,燃速相对极差随密度增加趋于稳定,最高精度达3.6%。在装药密度较低时,如<2.85 g/cm3,对应压药压强<100 MPa,燃速散布较大,延期精度低。 相似文献
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为了更好地研究发射药的点火性能,在基于密闭爆发器原理的点火性能测试装置基础上增加了一个延迟点火部件,构建了一个新型点火性能模拟试验装置,根据该装置建立了简单的火药分层点火过程模型,模拟并对比了高能太根-18/1、双芳-3-18/1及NR11-18/1三种发射药的点火性能。结果表明,NR11-18/1发射药较易点火,双芳-3-18/1发射药最难点火,点火时间分别为19和45ms。增加延迟点火部件后,可将点火药的燃烧和发射药的燃烧阶段有效区分,不仅有利于对比点火性能差异较小的发射药之间的区别,还有助于分析发射药低压段的燃烧速度。随着延迟点火部件长度的增加,点火时间也增长。 相似文献
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Ignition time delay of condensed mixtures containing various polyacrylic fuels and NH4ClO4 were measured using hot-plate technique at several temperatures. The adiabatic theory of explosion assuming condensed phase exothermic reactions was used to evaluate the activation energy of ignition. Activation energy of ignition has been found to be dependent on the decomposition characteristic of the fuel component. 相似文献
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Eugenia Romano Paolo Antonio Netti Enza Torino 《International journal of molecular sciences》2021,22(18)
In recent decades, endogenous nanocarrier-exosomes have received considerable scientific interest as drug delivery systems. The unique proteo-lipid architecture allows the crossing of various natural barriers and protects exosomes cargo from degradation in the bloodstream. However, the presence of this bilayer membrane as well as their endogenous content make loading of exogenous molecules challenging. In the present work, we will investigate how to promote the manipulation of vesicles curvature by a high-pressure microfluidic system as a ground-breaking method for exosomes encapsulation. Exosomes isolated from Uppsala 87 Malignant Glioma (U87-MG) cell culture media were characterized before and after the treatment with high-pressure homogenization. Once their structural and biological stability were validated, we applied this novel method for the encapsulation in the lipidic exosomal bilayer of the chemotherapeutic Irinotecan HCl Trihydrate-CPT 11. Finally, we performed in vitro preliminary test to validate the nanobiointeraction of exosomes, uptake mechanisms, and cytotoxic effect in cell culture model. 相似文献
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<正>各类爆破均存在拒爆(哑炮)现象,雷管与炸药同时拒爆,称为全拒爆;只有炸药拒爆,称为半拒爆。因起爆故障发生的拒爆大多是全拒爆。全拒爆处理很棘手,是矿山安全生产一大隐患。电雷管起爆法拒爆的原因大多与电有关,非电导爆管起爆法是否拒爆无法用仪器仪表检测,但大多与联线有关。电雷管与非电导爆管配用起爆法(以下简称配用起爆法)源于上述两种起爆法,各有异同,有其特点和规律性。笔者分析了配用起爆法拒爆的原因,提出了预防措施,以期达到抛砖引玉之效果。 相似文献
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Theoretically there seems to be a linear dependence between specific impulse and the ignition delay in liquid bipropellant systems. It has been observed that the plot of specific impulse versus mixture ratio of various systems based on red fuming nitric acid oxidizer show a maximum. The ignition delay versus mixture ratio plot of the same systems on the other hand show a minimum at a mixture ratio which corresponds to the maximum specific impulse. Thus, the mixture corresponding to maximum performance of a liquid bipropellant system could be qualitatively predicted from the ignition delay measurements. 相似文献
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Erika Ponzini Diletta Ami Alessandro Duse Carlo Santambrogio Antonella De Palma Dario Di Silvestre Pierluigi Mauri Fabio Pezzoli Antonino Natalello Silvia Tavazzi Rita Grandori 《International journal of molecular sciences》2021,22(19)
Lacrimal fluid is an attractive source of noninvasive biomarkers, the main limitation being the small sample amounts typically collected. Advanced analytical methods to allow for proteomics profiling from a few microliters are needed to develop innovative biomarkers, with attractive perspectives of applications to precision medicine. This work describes an effective, analytical pipeline for single-tear analysis by ultrahigh-resolution, shotgun proteomics from 23 healthy human volunteers, leading to high-confidence identification of a total of 890 proteins. Highly reproducible quantification was achieved by either peak intensity, peak area, or spectral counting. Hierarchical clustering revealed a stratification of females vs. males that did not emerge from previous studies on pooled samples. Two subjects were monitored weekly over 3 weeks. The samples clustered by withdrawal time of day (morning vs. afternoon) but not by follow-up week, with elevated levels of components of the immune system in the morning samples. This study demonstrates feasibility of single-tear quantitative proteomics, envisaging contributions of this unconventional body fluid to individualized approaches in biomedicine. 相似文献
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叠氮胺类燃料由于性能优越且低毒环保,被认为可替代肼类燃料用作双组元推进剂。针对如何提高经典叠氮胺燃料N,N-二甲基-2-叠氮乙胺(DMAZ)的点火性能进行分析,并介绍了几种缩短其点火延迟的方法,主要有添加剂复配法、结构改变法、催化剂法等。 相似文献
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采用分光光度计对塑料白度进行测定,是精确度比较高的一种方法。通过测定样品的各个波长光谱反射率,同时选取特定的标准光源与CIE标准观察者光谱三刺激值,从而计算出样品颜色三刺激值。在此基础上采用Taube白度公式(CIE推荐)即可计算出样品白度。 相似文献