亚音速飞行器往复式滑翔增程弹道设计

为增加亚音速巡航导弹的有效航程,提出一种往复式滑翔增程弹道方案。基于已有的气动参数建立水平直飞巡航弹道与往复式滑翔巡航弹道模型,对比分析2种弹道方案的有效航程及其特性,从能量守恒角度出发研究往复式滑翔的增程原理。进一步研究初始飞行马赫数、初始弹道倾角以及初始飞行高度对往复式滑翔弹道增程特性的影响。研究结果表明:往复式滑翔弹道能够有效增加导弹航程,相比于常规水平直飞弹道的最大飞行距离,往复式滑翔弹道的增程效率达到100.42%; 在往复式滑翔弹道能够成功的前提下,初始飞行马赫数越大,初始弹道倾角越小,初始飞行高度越低,往复式滑翔弹道的增程效率越明显。     

滑翔增程弹的气动特性仿真研究

研究了滑翔增程弹气动布局对弹道增程效果的影响,建立了不同气动布局下的弹体模型,并对其进行气动仿真,得出了不同空气动力数据.通过建立适合增程弹的弹体模型,得到了舵片在不同布局时的增程能力数据.仿真结果表明,舵片位置越远离弹体头部,相应增大舵偏角,增程能力将会增强,因此,在满足全弹气动布局、飞行稳定的基础上,尽量使舵片远离弹体头部,并相应增大舵偏角,可提高増程的能力.     

五菱乐驰轿车空档滑行怠速挂速的维修案例

结合大量维修实例,从不同角度诠释目前轿车普遍存在的车辆怠速时怠速过高或不稳的故障现象及原因,提出可行的解决方案。通过实际验证,证明这些方案能够快速地解决此类故障,为车辆其他方面的维修提供一个很好的借鉴。     

鸡冠嘴矿床构造特征及其控矿作用

鸡冠嘴铜金矿床位于断陷盆地边缘,其构造较为复杂,其基础构造是北西西一近东西向褶皱断裂系统,同时又发育有滑覆构造,成矿期叠加有北北东向的构造.滑覆构造与北北东向构造联合共同控制着矿床中矿体的分布,形成四个构造矿化分区.矿体主要赋存在叠加背斜的核部、滑覆背斜的核部、北北东向断裂两侧的羽状裂隙中.根据构造控矿规律,矿床具有极...     

Hyaluronan and the Fascial Frontier

The buzz about hyaluronan (HA) is real. Whether found in face cream to increase water volume loss and viscoelasticity or injected into the knee to restore the properties of synovial fluid, the impact of HA can be recognized in many disciplines from dermatology to orthopedics. HA is the most abundant polysaccharide of the extracellular matrix of connective tissues. HA can impact cell behavior in specific ways by binding cellular HA receptors, which can influence signals that facilitate cell survival, proliferation, adhesion, as well as migration. Characteristics of HA, such as its abundance in a variety of tissues and its responsiveness to chemical, mechanical and hormonal modifications, has made HA an attractive molecule for a wide range of applications. Despite being discovered over 80 years ago, its properties within the world of fascia have only recently received attention. Our fascial system penetrates and envelopes all organs, muscles, bones and nerve fibers, providing the body with a functional structure and an environment that enables all bodily systems to operate in an integrated manner. Recognized interactions between cells and their HA-rich extracellular microenvironment support the importance of studying the relationship between HA and the body’s fascial system. From fasciacytes to chronic pain, this review aims to highlight the connections between HA and fascial health.     

设备状态趋势的变参数指数加权平滑预测方法研究

对指数加权平滑模型进行了改进，使之能适用于多种不同变化规律的参数的预报，改进后的指数加权平滑模型的参数是随关参数变化规律的变化而变化的。这种预报模型具有自适应的特点，应用实例表明，改进的指数加权平滑模型具有较高的预测精度，可用于机械设备缓变趋势的预报。     

Vector Field Based Texture Mapping of Animated Implicit Objects

This paper shows that an adequate use of vectorfields can solve most inconsistencies related to texture mapping that appear in current animation and rendering systems based on implicit objects. The method used is based on the concept of a virtual skin. A skin with its own texture mapping is spread over an implicit object and is constrained to stick to the deformation of the implicit object. A vectorfield is used to compute the relationship between the motion of the skin and the deformation of the object. Visual and implementation issues are discussed with respect to typical applications of implicit objects in computer graphics.     

快移ZJ30DBT钻机的开发与研制

为提高钻机的移运性能,适应石油装备市场竞争,研制开发了ZJ30DBT交流变频电驱动丛式井全拖挂快移钻机。钻机的设计和制造依据"性能先进、工作可靠、运输方便、运行经济"的原则,具有安装和拆卸方便快捷、移运迅速、稳定性好、钻井效率高等优点。钻机同时适应丛式井作业,在丛式井井口移运时,使用电缆移运车拖运管线,电缆管线等连接均采用快速插头,方便快捷。现场试验及应用表明,该钻机移运最快速度60km/h,整套钻机在10km距离内搬迁时,用时少于17h,在丛式井作业中,9m内搬迁用时少于5h。     

基于准平衡滑翔的再入轨迹解析规划方法

针对禁飞区等多约束条件下的再入轨迹规划问题,提出了一种基于准平衡滑翔的再入轨迹规划解析方法。纵向剖面规划中,基于准平衡滑翔条件,以航程为自变量构建了相关弹道参数(如高度、速度、阻力加速度、攻角和倾侧角等)的解析表达式,建立了高度-航程空间内的多约束飞行走廊。横向剖面规划中,采用一种基于横、纵程多次函数的解析规划方法,有效解决了对禁飞区的规避问题。上述算法将复杂的多约束再入轨迹规划问题转化为简单的解析求解,极大提高了轨迹规划速度和可靠性。基于CAV-H的仿真算例表明,提出的轨迹规划算法运行速度快,规划结果平滑,精度高,逻辑简单且易于工程实现。     

拉伸用曲柄压力机的运动分析

在长工件变薄拉伸加工中应选用曲柄—摇杆机构,此机构能使滑块在工作行程中实现平稳的匀速运动,并可获得较高的工件表面质量。