Molecular mechanics modelling of interfacial energy and flexibility on cellulose

Molecular mechanics modelling is used to calculate the energies of interaction, hence the molecular level energy of adhesion at the interface with crystalline cellulose I of three different photopolymerizable primers and of a polyester varnish at the interface with the primer/cellulose assembly. The energy of interactions for just one of the primers with the statistically most common conformation of amorphous cellulose has also been obtained for comparison. Experimental results of adhesion by a standard peel test and by thermomechanical analysis, in which the effect of viscoelastic energy dissipation by crack tip propagation has been respectively minimized or is not present, hence in which the energy of interfacial interaction is nothing else but the work of adhesion, correlated well with the energies of interaction calculated by molecular mechanics. An equation correlating the energy of interaction at each finish/cellulose interface with the deflection derived by thermomechanical analysis, and with the number of internal bond rotational degrees of freedom as well as the degree of networking of the finish, has been derived and is presented. A relationship between the intrinsic fracture energy Go and the molecular mechanics-derived energy of interaction at the interface equating this to the square of the work of adhesion is obtained and is presented.     

基于DEM弛张筛面与颗粒群双向耦合的动态特性

颗粒和弛张筛筛面的双向耦合可以为筛机的系统动力学分析提供更加可靠的参考依据,但利用离散元软件EDEM和动力学仿真软件RecurDyn在进行联合仿真时,EDEM不支持柔性体的计算。为了模拟弛张筛面和物料的动态特性,提出了线性分段插值的方法对筛板进行近似柔性化处理。首先计算了近似柔性筛面中点在静止状态和内死点时的挠度和筛孔收缩率,并和悬链线柔性筛面的相对误差进行比较,证明了近似柔性化方法的可行性。然后基于所建立的近似刚柔耦合模型,研究了偏心块质量,筛面倾角和入料粒度组成对筛分效率、生产率和颗粒速度等筛分性能指标的影响。结果表明:筛分效率,生产率和颗粒速度等筛分性能指标与偏心块质量,筛面倾角和入料粒度组成等参量之间均为非线性关系。筛分效率随着偏心块质量、筛面倾角和入料粒度含量的减小而增加;生产率随着偏心块质量的增加而减小,而生产率与筛面倾角、入料粒度含量之间的关系却相反,但难筛颗粒含量为25%时生产率最低,此外,为了考虑筛分效率和生产率同时达到最优,偏心块质量应取为0. 5m0;颗粒运动速度随着偏心块质量和筛面倾角的增加呈递增趋势,但受入料粒度组成的影响较小。研究为进一步揭示潮湿细粒煤的运动规律和弛张筛筛面的动力学分析提供了思路。     

柔性化测试数据处理技术

为弥补传统测试系统数据处理功能柔性不足的缺点 ,提出通过建立用户自定义变量及模型库的方法来实现测试数据处理的柔性化 ,从而增强测试系统的开放性和通用性。     

移民安置与区域经济发展系统多层模型与优化技术综述

讨论了移民系统与区域经济发展系统的构成、特征和功能，进而提出了研究这种复合系统的物理分解方式和结构．阐述了多层结构的特征与优化技术．最后讨论了借助于专业知识的广义优化技术和今后研究趋势．     

Deeply Reconstructed Hierarchical Ni–Co Microwire for Flexible Ni–Zn Microbattery with Excellent Comprehensive Performance

The rise of flexible electronics calls for efficient microbatteries (MBs) with requirements in energy/power density, stability, and flexibility simultaneously. However, the ever-reported flexible MBs only display progress around certain aspects of energy loading, reaction rate, and electrochemical stability, and it remains challenging to develop a micro-power source with excellent comprehensive performance. Herein, a reconstructed hierarchical Ni–Co alloy microwire is designed to construct flexible Ni–Zn MB. Notably, the interwoven microwires network is directly formed during the synthesis process, and can be utilized as a potential microelectrode which well avoids the toxic additives and the tedious traditional powder process, thus greatly simplifying the manufacture of MB. Meanwhile, the hierarchical alloy microwire is composed of spiny nanostructures and highly active alloy sites, which contributes to deep reconstruction (≈100 nm). Benefiting from the dense self-assembled structure, the fabricated Ni–Zn MB obtained high volumetric/areal energy density (419.7 mWh cm⁻³, 1.3 mWh cm⁻²), and ultrahigh rate performance extending the power density to 109.4 W cm⁻³ (328.3 mW cm⁻²). More surprisingly, the MB assembled by this inherently flexible microwire network is extremely resistant to bending/twisting. Therefore, this novel concept of excellent comprehensive micro-power source will greatly hold great implications for next-generation flexible electronics.     

Ultra-Flexible Monolithic 3D Complementary Metal-Oxide-Semiconductor Electronics

Flexible electronics based on complementary metal-oxide-semiconductor (CMOS) technology have enabled a smart soft world. However, the trade-off among flexibility, density, and electrical performance has been a long-lasting unresolved issue. Here, a monolithic three-dimensional (M3D) CMOS design is proposed to address this problem and realize ultra-flexible electronics with high electronic-performance and integration. This design utilizes vertically stacked p-type carbon nanotube transistors and n-type indium gallium zinc oxide ones, which share common gates and drains, saving the inter tier vias required in the traditional M3D structure to reduce routing and improve flexibility. With this design, CMOS logic gates, multi-stage circuits, ring oscillators (ROs) and memory modules, are demonstrated. This design enables circuits to save up to 45% of area compared with their planar counterparts. Particularly, inverters exhibit a record-high gain of 191, and 55-stage ROs can operate well even after bending at a 500-µm radius for 50 cycles, exhibiting the highest flexibility among the reported ones. The ultra-flexible and high-integration RO enables a wearable light recorder to collect harmful blue light shining into human eyes by simply attaching the circuits on a contact lens. This integration method provides possibilities for developing complex-function wearable electronics.     

Machine Sharing in Manufacturing Systems: Total Flexibility versus Chaining

In this paper, we compare the operational performance of two machine-sharing configurations: total flexibility and chaining. We show that chaining captures most of the benefits of total flexibility while limiting the number of part types processed on any individual machine to only two. We examine the relative desirability of the two configurations under varying buffer sizes, loading conditions, number of machines, and setup times, as well as for different control policies. For nonzero setups times, we show that chained configurations can outperform fully flexible ones. This particularly is the case when either the number of machines or length of setup times is high. We also find that the effect of the system size on performance diminishes with the number of machines. This means that multiple smaller chains can perform almost as well as a single long one. Our results are consistent with the recent findings of Jordan and Graves (1995), who examined the economic benefits of chaining relative to full flexibility.     

铁路轴承保持器兜孔垂直度检测

铁路客车轴承保持器在生产过程中,兜孔垂直度靠模具和拉刀保证,由于拉孔过程中没有直接检测兜孔垂直度,导致轴承旋转灵活性降低。文中设计制造了一台保持器兜孔垂直度检测仪器,对工序间及成品保持器进行兜孔垂直度检测控制,保证了轴承旋转灵活性,降低了高速铁路机车的能源消耗。     

75t/h生物质锅炉技术介绍

本文详细介绍了中温分离循环流化床生物质锅炉技术特点,设计工作中遇到的难点及解决的方案.以湖南某浆纸公司已运行的两台75/h生物质锅炉为例,详细介绍了锅炉运行产生的显著经济效益和社会效益.并客观分析其运行反应出的问题.对今后生物质锅炉制造提供借鉴.     

计及多种灵活性约束和基于时序模拟的广域电力系统源-网-储协同规划方法

随着全球大规模风电、光伏的持续开发,系统的净负荷波动不断增加,迫切需要建立可量化而又高效的广域电力系统优化规划模型,促进广域范围多种灵活性资源规划研究.首先,以简化的机组组合模型为基础,建立计及多种灵活性资源出力约束和基于时序的生产运行模拟模型,以系统总成本最低为优化目标,考虑多种投资决策和生产运行约束,最终优化出系统...