针对地球轨道航天器,当其进出地球阴影区时,会受到快速冷热交变热载荷的作用.随着社会发展的需求,航天器正向大型化、复杂化和精密化的方向发展.在结构设计阶段,能够对航天器进行准确、高效的热-结构动力学分析就显得尤为重要.
火箭弹发射过程中的起始扰动受到多种因素的综合作用,直接影响火箭弹的命中精度和可靠性,现有对于火箭弹的速度、位移、转速、转角等起始扰动的研究主要采用多刚体动力学理论进行建模,由火箭弹发射动力学方程直接求解,多考虑的是弹体质量偏心、动不平衡及推力偏心等因素对火箭弹起始扰动的影响,而对于大型火箭弹而言,弹体相对较大,弹体变形对发射起始扰动的影响不可忽略.
Nature achieves remarkable functional diversity from macromolecules with precisely defined structures built using only a few monomers.Despite numerous recent advances towards the goal of precision pol
Solid silicon oxycarbide(SiCO)ceramic microspheres and rigid porous siloxane microspheres were obtained in a two step process.First,polysiloxane microspheres with a large number of Si-OH groups in the
Thermoplastic elastomers(TPEs)are generally entropic networks with micro-phase separated morphology.They are made of flexible chain segments which impart elastic properties and physical crosslinks whi
Sequence controlled polymers are defined as macromolecules whose monomer arrangements are in precise order.In traditional copolymers the distribution of monomers is usually uncontrolled or statistical
Controlled/living radical polymerization techniques have transformed polymer chemistry in the last few decades,affording the production of polymers with precise control over both molecular weights and
The layer-by-layer(LbL)electrostatic assembly technique has become a relatively mature and effective method for fabrication of functional thin films and surface modification.By direct assembly of biom
Due to the strong π–π* stacking of conjugated segments,the emission of conjugated polymers is often quenched dramatically in an aggregated state.This drawback greatly limits their application.To avoid
This study involves the bottom-up design and tunability of responsive,peptide-based block copolymers.The self-assembly of amphiphilic block copolymers is dictated primarily by the balance between the