THE UNIQUENESS OF A TRANSONIC SHOCK IN A NOZZLE FOR THE 2-D COMPLETE EULER SYSTEM WITH THE VARIABLE END PRESSURE

In this paper, by use of the methods in [1-3], we establish the uniqueness of a 2-D transonic shock solution in a nozzle when the end pressure in the diverging part of the nozzle lies in an appropriate scope. Especially, we remove the crucial but unnatural assumption in recent references which the transonic shock must be assumed to go through a fixed point in advance.     

He's homotopy perturbation method for solving the shock wave equation

In this article, we discuss the analytic solution of the fully developed shock waves. The homotopy perturbation method is used to solve the shock wave equation, which describes the flow of gases. Unlike the various numerical techniques, which are usually valid for short period of time, the solution of the presented equation is analytic for 0 < t < ∞. The results presented converge very rapidly, indicating that the method is reliable and accurate.     

拉氏数值模拟中的人工粘性方法

较好的人工粘性需要满足较小的计算开销、不能去除真实具有的涡运动等条件.提出一种应用于拉氏数值模拟中基于Lew人工粘性,同时增加了限制器的人工粘性方法.可以有效减少数值模拟结果对网格的依赖;采用特征值限制器控制施加的人工粘性大小,通过限制器能够区分激波压缩和等熵压缩;方便应用在二维、三维,结构网格或者非结构网格上.     

电弧放电等离子体诱导激波的计算

基于电弧放电物理过程,分析气动激励机理,建立用于电弧放电等离子体诱导激波数值模拟的爆炸丝传热模型.主要结论有:电弧放电等离子体气动激励的主要机理是热等离子体的热阻塞效应,热电弧放电对于超声速来流而言就像-个具有-定斜坡角度的虚拟突起;理论分析只适用于纵坐标较小的阶段;当传热的功率设为放电功率的10%时,本文所建立的模型能够用于电弧放电等离子体诱导激波的仿真研究;等离子体虚拟斜坡角度及其诱导激波角都随来流总压和速度的增大而减小,随着放电功率的增大而增大,在总压、速度和放电功率较小的阶段这种变化较明显,在总压、速度和放电功率较大的阶段这种变化较缓慢.     

高速摄影在流体动力学不稳定性研究中的应用

用高速摄影技术研究了高压气体膨胀驱动空气-水界面的瑞利-泰勒不稳定性,获得了空气-水界面的不稳定性清晰图像,得到气炮尖顶运动速度及湍流混合层高度增长速度与时间关系曲线。在横式激波管上用高速纹影诊断技术研究了激波作用空气-SF6界面的里克特迈耶-梅什科夫不稳定性,初步获得了实验图像,可清晰显示混合区变化过程。     

冲击加载下Zr51Ti5Ni10Cu25Al9金属玻璃的塑性行为

进行了10—27 GPa应力范围内Zr₅₁Ti₅Ni₁₀Cu₂₅Al₉金属玻璃的平面冲击实验以研究其高压-高应变率加载下的塑性行为.由样品自由面粒子速度剖面的分析获得了冲击加载过程的轴向应力,并通过轴向应力与静水压线的比较获得剪应力.实验结果表明,尽管存在明显的松弛效应,但Zr基金属玻璃的Hugoniot弹性极限随着冲击应力的增加而增加.然而,塑性波阵面上的剪应力则显示先硬化而后软化现象,而且软化的幅度随冲击应力的增加而增加.冲击加载下Zr基金属玻璃的上述剪应力变化特征与分子动力学模拟结果比较一致,但与压剪实验结果和一维应力冲击实验结果明显不同.     

核爆聚变电站发电时的冲击波超压传播规律

 核爆聚变电站在发电时会产生冲击波,其超压传播规律是核爆聚变电站洞壁设计的重要基础。现有公式在描述冲击波峰值超压时存在一定的不足（如相对误差大等）。通过理论分析得到新的冲击波峰值超压公式、正压作用时间τ₊和冲击波传播系数ω,最终得到冲击波超压的传播规律。通过对比分析表明,新公式比现有公式更加适合求解核爆聚变电站发电时所产生的冲击波峰值超压。     

低温下JB-9014钝感炸药DSD参数研究

 爆轰冲击波动力学（Detonation Shock Dynamics,DSD）是目前研究爆轰波非理想传播的有效途径。利用DSD的广义几何光学模型,研究了大长径比药柱中爆轰波非理想传播现象,根据-30 ℃下直径为10～30 mm药柱的直径效应实验数据,利用遗传算法确定了低温下JB-9014钝感炸药的DSD参数。由DSD参数计算得到了JB-9014药柱中的定态波形和爆速,计算结果与实验结果符合。     

Lysosomal pH Rise during Heat Shock Monitored by a Lysosome‐Targeting Near‐Infrared Ratiometric Fluorescent Probe

Heat stroke is a life‐threatening condition, featuring a high body temperature and malfunction of many organ systems. The relationship between heat shock and lysosomes is poorly understood, mainly because of the lack of a suitable research approach. Herein, by incorporating morpholine into a stable hemicyanine skeleton, we develop a new lysosome‐targeting near‐infrared ratiometric pH probe. In combination with fluorescence imaging, we show for the first time that the lysosomal pH value increases but never decreases during heat shock, which might result from lysosomal membrane permeabilization. We also demonstrate that this lysosomal pH rise is irreversible in living cells. Moreover, the probe is easy to synthesize, and shows superior overall analytical performance as compared to the existing commercial ones. This enhanced performance may enable it to be widely used in more lysosomal models of living cells and in further revealing the mechanisms underlying heat‐related pathology.     

Molecular Hybridization Strategy on the Design,Synthesis, and Structural Characterization of Ferrocene-N-acyl Hydrazones as Immunomodulatory Agents

Immunomodulatory agents are widely used for the treatment of immune-mediated diseases, but the range of side effects of the available drugs makes necessary the search for new immunomodulatory drugs. Here, we investigated the immunomodulatory activity of new ferrocenyl-N-acyl hydrazones derivatives (SintMed(141–156). The evaluated N-acyl hydrazones did not show cytotoxicity at the tested concentrations, presenting CC₅₀ values greater than 50 µM. In addition, all ferrocenyl-N-acyl hydrazones modulated nitrite production in immortalized macrophages, showing inhibition values between 14.4% and 74.2%. By presenting a better activity profile, the ferrocenyl-N-acyl hydrazones SintMed149 and SintMed150 also had their cytotoxicity and anti-inflammatory effect evaluated in cultures of peritoneal macrophages. The molecules were not cytotoxic at any of the concentrations tested in peritoneal macrophages and were able to significantly reduce (p < 0.05) the production of nitrite, TNF-α, and IL-1β. Interestingly, both molecules significantly reduced the production of IL-2 and IFN-γ in cultured splenocytes activated with concanavalin A. Moreover, SintMed150 did not show signs of acute toxicity in animals treated with 50 or 100 mg/kg. Finally, we observed that ferrocenyl-N-acyl hydrazone SintMed150 at 100 mg/kg reduced the migration of neutrophils (44.6%) in an acute peritonitis model and increased animal survival by 20% in an LPS-induced endotoxic shock model. These findings suggest that such compounds have therapeutic potential to be used to treat diseases of inflammatory origin.