不同热解工艺下半焦的微观结构特点及其对燃烧性能的影响

摘要：对比研究了3种直立内热炉半焦(熄焦方式分别为水泡熄焦、喷水熄焦及烟气干熄焦)及一种流化床热解半焦的微观结构及燃烧性能。通过对半焦组成、孔隙结构、有机官能团、碳化学结构及半焦微晶结构分析，获得了不同低温热解工艺半焦的组成及微观结构特点，明确了组成及微观结构与燃烧性能之间的关系。结果表明，不同热解工艺半焦的组成和微观结构差异明显，其对半焦的燃烧性能影响显著。干熄焦碳化学结构缺陷比例大，快速热解半焦孔隙结构发0达、挥发分高，与水喷焦相比水泡焦石墨化程度低；水喷焦燃烧性能优于水泡焦，干法所得半焦的燃烧性优于湿法；半焦的挥发分含量决定其燃点，在快升温速率条件下孔隙结构对半焦的燃烧性能影响较大，而慢升温速率条件下有序化度对半焦的燃烧性能影响较大。     

基于XML的信息物理融合系统组件建模与仿真

信息物理融合系统（CPS）涉及多种计算模型的集成和协同工作，针对CPS设计方法不统一、重塑性差、复杂度高、难以协同建模验证等问题，提出一种结构化、可描述行为的异元组件模型。首先，用统一组件建模方法进行建模，解决模型不开放问题；然后，用可扩展标记语言（XML）规范描述各类组件，解决不同计算模型描述语言不一致和不可扩展问题；最后，用多级开放组件模型的协同仿真验证方式进行仿真验证，解决验证的不可协同问题。通过通用组件建模方法、XML组件规范描述语言以及验证工具平台XModel对医用恒温箱进行了建模、描述和仿真。医用恒温箱的案例表明，这种模型驱动建立可重塑异元组件并确认其设计正确性的过程，支持信息物理协同设计和边构建边纠正，可避免在系统实现过程中发现问题时再进行反复修改。     

面向数据流结构的指令映射优化方法

在高性能计算领域,数据流是一类重要的计算结构,也在很多实际场景表现出很好的性能和适用性。在数据流计算模式中,程序是以数据流图来表示的,数据流计算中一个关键的问题是如何将数据流图映射到多个执行单元上。通过分析现有数据流结构的指令映射方法及其不足,提出了基于数据流结构的新型指令映射优化方法。主要是根据多地址共享数据包的特性对指令映射方法进行优化,延迟多地址共享数据路由包的拆分,减少网络拥堵。     

Preparation of fused silica membrane with high performance for high temperature gas filtration by sealing and spray coating

In order to improve the gas permeability and thermal shock resistance of the ceramic membranes applied in high temperature gas-solid separation techniques, fused silica and graphite particles were used as the primary raw material and pore-former agent, and the spray coating based-on PVA sealing was applied to prepare the separation membrane. These approaches remarkably decreases filtration resistance by increasing support permeability and reducing the intrusion of ceramic membrane forming particles into the support as well as the thickness of the membrane. The fabricated membrane had an average pore diameter of 9.85?μm and a gas permeability value of 8.2?×?10⁴?m³/(m² h bar), its dust removal efficiency reached 98.6%.     

Effects of Nucleus Density and Dendritic Growth Influenced by Ti and Nb on Solidification Structure of Fe-18 Pct Cr Ferritic Stainless Steel

Metallurgical and Materials Transactions B - The effects of nucleus density and dendritic growth influenced by Ti and Nb on the solidification structure of Fe-18 pct Cr ferritic stainless steel...     

Axisymmetric hub-endwall profile optimization for a transonic fan to improve aerodynamic performance based on an integrated design optimization method

Structural and Multidisciplinary Optimization - This paper investigates an optimization for the axisymmetric hub-endwall profile of a transonic fan designed for a civil high bypass ratio turbofan...     

In situ characterization of LiY(WO4)2 nanotubes for electrochemical energy storage

Here, LiY(WO₄)₂ nanotubes are prepared via a feasible electrospinning technique. This new anode material shows excellent electrochemical properties. The capacity loss of LiY(WO₄)₂ nanotubes is as low as 6.9% after 156 cycles, while bulk LiY(WO₄)₂ presents the capacity loss higher than 55.0%. Even after 600 long-life cycles, the capacity loss of the nanotubes is only 9%. It can be seen that the hollow structure with a rough surface and a porous morphology contributes to the improvement of electrochemical performance. Furthermore, online X-ray diffraction (XRD) method is firstly applied to understand the lithium ions insertion/extraction mechanism of LiY(WO₄)₂ nanotubes. It can be concluded that it is an asymmetrical two-phase reaction. A phase transformation from LiY(WO₄)₂ to Li₃Y(WO₄)₂ can be obviously seen from the in situ XRD during discharge process. While Li₂Y(WO₄)₂ appears as an intermediate phase with a reverse charge reaction. In addition, in situ XRD also demonstrates that LiY(WO₄)₂ nanotubes have surprised electrochemical reversibility. All the above results indicate that LiY(WO₄)₂ nanotubes can be expected to be anode candidate for rechargeable lithium ion batteries (LIBs).     

Ni@N-doped graphene nanosheets and CNTs hybrids modified separator as efficient polysulfide barrier for high-performance lithium sulfur batteries

Lithium-sulfur batteries (LSBs) have been regarded as one of the most promising energy storage systems to break through the upper limit of lithium-ion batteries. However, the rampant diffusions of soluble lithium polysulfides (LiPSs) in the electrolyte induced the shuttle effect between anode and cathode, resulting in low sulfur utilization, low energy efficiency and short cycling life. Herein, we prove the rational design and construction of Ni nanoparticles filled in vertically grown N-doped bamboo-like carbon nanotubes (CNTs) on graphene nanosheets (Ni@NG-CNTs) as efficient polysulfide barrier for high-performance LSBs. The unique design integrates graphene nanosheets and CNTs into hierarchical architectures with one-dimensional (1D) CNTs, two-dimensional (2D) ultrathin nanosheets and abundant carbon nanocages. This design provides large surface area for lithium polysulfides (LiPSs) adsorption, accelerates electron transport and enhances electrochemical redox of LiPSs. Benefiting from the unique structural features, the LSBs with the Ni@NG-CNTs as polysulfide barrier keep high reversible specific capacities of 309.1 and 265.0 mAh·g⁻¹ at 5 and 10 C rates after 500 cycles. This work provides a new strategy for constructing self-assembled hybrids of CNTs and graphene nanosheets with abundant carbon nanocages for high-performance LSBs.