Dynamical ensembles in stationary states

We propose, as a generalization of an idea of Ruelle's to describe turbulent fluid flow, a chaotic hypothesis for reversible dissipative many-particle systems in nonequilibrium stationary states in general. This implies an extension of the zeroth law of thermodynamics to nonequilibrium states and it leads to the identification of a unique distribution describing the asymptotic properties of the time evolution of the system for initial data randomly chosen with respect to a uniform distribution on phase space. For conservative systems in thermal equilibrium the chaotic hypothesis implies the ergodic hypothesis. We outline a procedure to obtain the distribution : it leads to a new unifying point of view for the phase space behavior of dissipative and conservative systems. The chaotic hypothesis is confirmed in a nontrivial, parameter-free, way by a recent computer experiment on the entropy production fluctuations in a shearing fluid far from equilibrium. Similar applications to other models are proposed, in particular to a model for the Kolmogorov-Obuchov theory for turbulent flow.     

Multiple gateway placement in large‐scale constellation networks with inter‐satellite links

Multiple gateways are required in large satellite constellation networks (LSCNs) with inter‐satellite links (ISLs), and their placement may greatly affect the system performance. Gateway placement can be optimized to achieve better network performance under the non‐uniform ground demand distribution. This paper formulates a gateway placement optimization model for LSCN with ISLs, aiming at achieving an optimal overall performance including delay, traffic peak, and load balance. The constraints of potential gateway location, gateway‐satellite connectivity, and max hop‐count are considered. A genetic algorithm (GA)‐based method is proposed to solve the integer optimization problem with the help of quasi‐evenly distributed reference layout. A Starlink‐like constellation with ISLs is adopted in the simulation. The simulation results show that the optimized layout has better performance than the reference layout. Additionally, the locations with high user demand or at the middle of ocean are preferred by gateways. The network performance is jointly influenced by gateway placement, demand distribution, constellation configuration, node, and link capacities. The abnormally high ISL hop‐count is found in the south Indian Ocean, which is caused by constellation and ISL configuration.     

All Slot-Die Coated Non-Fullerene Organic Solar Cells with PCE 11%

Slot-die (SD) coating is used to fabricate fully solution processed organic solar cells (OSCs) based on a blend of high performance donor polymer (PTB7-Th) and a non-fullerene acceptor (IEICO-4F) for stable devices over extended periods of operation. The optimization of a sequential deposition process of transport and active layers, under ambient conditions, enable high efficiency slot-die coated solar cells with remarkable power conversion efficiencies (PCE) > 11.0% to bridge the gap between lab-to-fab. Fully slot-die coated inverted OSCs are demonstrated with efficiencies reaching 11% along with 1 cm² devices, proving the scalability and reproducibility of the proposed technique. Further, replacing the evaporated Ag electrode with solution processed Ag nanowire (AgNW) electrodes shows the highest light utilization efficiency of 5.26% for semi-transparent OSC with a PCE of 9.07% and average visible transmission of 58%.     

德清广电全省首个“数字安监”系统建设与运行

广电行业近年来不断受到移动、电信等多家运营商的冲击,传统广电业务不断萎缩。为了谋求发展,开拓新市场、新业务,德清广电与湖州莫干山高新技术产业开发区合作,打造了浙江省工业园首个"数字安监"系统,并负责项目运营。     

基于模型预测控制的大口径快摆镜随动系统

为了满足地基大口径望远镜精密稳像系统的需求,对大口径快摆镜(FSM)的控制方法进行了研究。为了解决三促动器FSM的运动解耦为系统辨识带来的困难,通过解析法和系统辨识法相结合建立了FSM的传递函数模型。依据该模型,设计了PID控制器与模型预测控制器(MPC),采用仿真和实验两种方式比较了两种控制器的效果。仿真结果表明,在受到阶跃扰动后,MPC控制器的恢复速度是PID控制器的45倍。在50 Hz正弦信号下,由于FSM的大惯量特点,PID控制器有严重的时滞,而MPC控制器能以1.224×10^-6″的误差稳定跟随。在噪声抑制方面,对实时加入10%幅值噪声的随机信号,MPC控制器的噪声抑制效果是PID控制器的13.3倍。实验结果表明,MPC控制器能以0.430″的误差稳定跟随50 Hz正弦信号,其跟踪精度是PID控制器的3.212倍,采用MPC控制器的快摆镜能满足快摆镜高带宽和高精度的需求。     

TFT-LCD摩擦工艺ESD研究与改善

摩擦工艺ESD(Electrostatic Discharge)是TFT-LCD制程中较为常见的一种不良,以317.5 mm(12.5 in)产品为例,摩擦工艺过程中ESD发生率20%,对产品良率影响较大。文章结合实际生产对摩擦工艺ESD的原因进行理论分析与实验验证,得出摩擦工艺发生ESD的原因为TFT基板上面有悬空的大块金属,在摩擦过程中电荷积累过多容易发生ESD,ESD进一步烧毁旁边金属电路导致面板点亮时画面异常。生产过程中通过工艺管控和产品设计两方面优化改善,工艺方面通过增加湿度,涂布防静电液以及管控摩擦布寿命进行改善,设计方面通过变更悬空的大块金属为小块金属,通过工艺设计优化最终生产过程中摩擦工艺ESD发生率由20%下降到0%,大大提高了产品品质,降低了生产成本。     

An Effective Method for Recovering Nonradiative Recombination Loss in Scalable Organic Solar Cells

Regarded as a critical step in commercial applications, scalable printing technology has become a research frontier in the field of organic solar cells. However, inevitable efficiency loss always occurs in the lab‐to‐manufacturing translation due to the different fabrication processes. In fact, the decline of photovoltaic performance is mainly related to voltage loss, which is mainly affected by the diversity of phase separation morphology and the chemical structures of photoactive materials. Fullerene derivative indene‐C₆₀ bisadduct (ICBA) is introduced into a PBDB‐T‐2F:IT‐4F system to control the active layer morphology during blade‐coating process. Accordingly, as a symmetrical fullerene derivative, ICBA can regulate the crystallization tendency and molecular packing orientation and suppress charge carrier recombination. This ternary strategy overcomes the morphology issues caused by weaker shear impulse in blade‐coating process. Benefiting from the reduced nonradiative recombination loss, 1.05 cm² devices are fabricated by blade coating with a power conversion efficiency of 13.70%. This approach provides an effective support for recovering the voltage loss during scalable printing approaches.     

铁路5G-R基站太阳能供电架构及应用

针对铁路5G专用移动通信(5G-R)系统基站布置密集、单体功耗高的特点,结合铁路无线通信的需求,研究采用太阳能(PV)为5G-R系统基站的射频拉远单元(RRU)设备供电的方案。对比分析5G-R系统RRU设备日用电规律及太阳能电池日发电规律,确定了采用太阳能结合储能与外电源的供电体系,通过比较几种太阳能电池与外电源组合供电架构的经济性与可靠性,推荐采用直流侧切换的供电架构,并进一步提出了采用直流侧智能配电的太阳能供电方案。本研究在保证5G-R系统运行安全可靠的同时,通过采用太阳能供电方式降低了铁路5G-R系统对外电源的需求。