小型直喷式柴油机喷雾特性的试验研究

为了掌握喷雾的结构物特性,利用高速摄像装置和高压容器拍摄了喷雾的逆光图像,并研究了喷雾周围介质压力对喷雾贯穿距离、喷雾锥角以及蒸发等喷雾特性的影响。在液滴数密度较大的条件下,燃料液滴的蒸发速率传热过程和雾化质量的影响;喷射妆期喷雾的贯穿距离和贯穿速度几乎不受介质物影响;喷雾的贯穿跨离受喷油压力的影响不大,但随着喷油压力的提高,喷雾锥角增大,喷雾质量得到改善。     

Design of High Capacity Dissoluble Electrodes for All Transient Batteries

Transient electronics is an emerging engineering realm that requires materials, devices, and systematic designs with excellent and stable performance in regular operations, but to physically and chemically disappear at a prescribed time with controlled rates once being triggered by external stimulus, leaving no or minimum remnants. In this article, a high energy density rechargeable battery with a fully transient cathode based on tin (Sn)‐doped vanadium oxide (V₂O₅) is designed. Sn‐doped V₂O₅ nanofibers with a high mass loading of 12 mg cm^?2 are prepared and no conducting additive or binder is added to fabricate full cells. The transient battery exhibits an areal capacity of 2 mAh cm^?2 with a working voltage above 2.0 V and provides 0.27 mAh cm^?2 capacity at a current as high as 17.76 mA cm^?2. Once triggered by potassium hydroxide (KOH) aqueous solution, the full cell can be completely dissolved into the solution within a few minutes to achieve highly transient capability. This work provides a new approach to achieve an all‐transient lithium battery with high areal capacity for transient electronics applications.     

Changes in the K+ current-density of MCF-7 cells during progression through the cell cycle: possible involvement of a h-ether.a-gogo K+ channel.

MCF-7 cells express voltage-activated K+ channels. In the present study, we used the patch-clamp and RT-PCR techniques to investigate the involvement of these channels during the cell cycle progression. The outward rectifier current (IK) recorded during depolarization was almost completely suppressed by the classical K+ channel blocker tetraethylammonium (TEA) in MCF-7 cells. TEA also inhibited cell proliferation, as measured with 3H-thymidine incorporation. Moreover, profound changes were observed in both the resting membrane potential (RMP) and IK during the release from the G0/G1 phase of the cell cycle. MCF-7 cells arrested in G0/G1 were depolarized (-26.3 +/- 10 mV, n = 30) and IK-density was small (9.4 +/- 5.6 pA/pF, n = 60) compared to cells progressing in the G1 phase (RMP = -60 +/- 7.9 mV; n = 35 and IK-density = 30.2 +/- 8.5 pA/pF; n = 76). IK was highly sensitive to Mg2+, astemizole and TEA (10 mM). Extracellular perfusion of 5 mM Mg2+ dramatically slowed the activation and perfusion of 2 microM astemizole inhibited both IK (20 +/- 3%) and cell proliferation (23%). Moreover, the h-EAG mRNA expression was modulated during the cell cycle. Thus, these data suggested that h-EAG K+ channels play a role in controlling the proliferation and/or cell cycle.     

装药设备液压系统的维护方法

装药是弹体生产的核心工艺,装药设备的液压系统是保障设备正常工作的关键动力部分。由于工作环境差、使用频率高,装药设备的液压系统常会出现故障问题。结合工作实践,以辽沈工业集团有限公司LLZJ-Ⅲ立式自动螺旋装药机、FYJ-821分步压装机等为例进行论证,总结实际生产中遇到的问题,对液压系统维修和维护保养过程中常遇问题进行分析。在此基础上,有针对性地对装药机液压系统的安装、使用过程的污染控制、系统维修和维护保养过程中的注意事项进行阐述,从而证实了液压系统维护的重要性;由此可见,液压系统维修和维护保养方法是一项系统工程,对液压系统维修和维护保养首要的是对系统的污染物的控制,并要定期对各液压系统的元器件等进行检测与维修,对提高工作效率,降低生产成本有十分重要保障的意义。     

大气层内高超声速飞行器级间旋转分离方法

提出一种大气层内高超声速飞行器的级间旋转分离方法,通过级间气动流场的简化计算和分离过程的动力学仿真,对分离过程进行仿真分析。分析结果表明,通过选择合理的分离参数,可以利用空气动力实现上下两级的安全分离。该分离方法对大气层内高超声速飞行器的级间分离工程设计具有借鉴意义。     

RDX单晶的培养与表征

基于RDX单晶可用于其起爆机理和力学响应机制等基础研究,采用丙酮溶剂缓慢挥发法分别在室温和恒温条件下培养RDX单晶。结果表明：两种方法都可以得到厘米级的RDX单晶,在恒温条件下培养的RDX单晶质地较硬、密度较高;同时,对实验中出现的多种晶体缺陷进行了分析;应用X-射线单晶衍射法测定了恒温条件下培养的RDX晶体结构,表明其晶体属于正交晶系,空间群为Pbca,所得晶体学参数为：a=11.471(3)?,b=10.611(2)?, c=13.146(3)?,α=β=γ=90°,体积V=1600.1(6)nm3,Z=8,密度D=1.844g/cm3,F(000)=912。最终偏差因子R1=0.0309。     

单兵肩射平衡抛发射器噪声分析及抑制机构设计与实现

为了实现单兵肩射平衡抛发射器的低噪声发射,文中在对发射噪声的形成过程及原因进行分析研究的基础上。利用薄壁环在火药气体压力的作用下径向膨胀变形原理,设计出一种噪声抑制机构。通过数值仿真和样机动态验证试验表明,平衡抛发射器的发射噪声平均小于162 dB,实现了低噪声发射。为此类发射器的工程设计提供了技术参考。     

基于故障树编码的火炮故障诊断方法研究

基于故障树的故障诊断方法核心在于故障原因的自动推理和快速定位。构建了故障自动推理编码规则,可将故障树转换成一系列可操作的且具有一定逻辑关系的编码,实现故障自动推理和诊断。通过某型火炮故障推理实例验证,表明该方法层次结构清晰,推理简单有效,能够实现装备LRU级分层故障诊断和故障原因的快速定位。     

气压高度表在空射诱饵弹控制系统中的应用

针对某型空射诱饵弹控制系统研制中的特殊要求,提出了一种新的控制方案,即气压高度表 惯性器件替代惯性导航系统,以满足控制系统的要求。文中对两种控制方法在控制精度等方面进行了分析、仿真和比较。     

Nonlinear model predictive control based on the moving horizon state estimation for the solid oxide fuel cell

As a nonlinear power generation device, the solid oxide fuel cell (SOFC) often operates under small window of operating conditions due to the constraints stemming from the environmental and safety considerations. The nonlinear model predictive control (NMPC) appears to be well suited control algorithm for this application. NMPC is a closed-loop feedback control scheme that predicts the open-loop optimal input based on the measurements and the setting trajectory. This work aims to develop a closed-loop feedback control strategy based on the NMPC controller for a planar SOFC. The current density, fuel and air molar flow rates are chosen as manipulated variables to control the output power, fuel utilization and temperature. The mole fraction and temperature of the exit gases are set as state variables, which can be estimated from the moving horizon estimation (MHE) method. The validation here is referred to robustness and stability of the controller, a typical case study has been conducted with the power output changes under constant fuel utilization and temperature. Simulation results show that the noise of the output is successfully filtered by the MHE. The NMPC controller works satisfactorily following the setting output trajectory.