基于结构方程模型的武器装备体系涌现性度量模型

针对武器装备体系作战能力涌现性难以评估和度量的问题,提出了武器装备体系作战能力涌现性的度量模型。以复杂自适应系统为视角建立作战能力涌现性的概念模型,并剖析体系中各个子系统的内在因素,从而建立评价度量模型作战能力的指标体系;根据指标体系构建线性和非线性涌现的结构方程模型（SEM）;结合两种SEM度量模型构造了模型参数结构方程。为验证所提武器装备体系作战能力涌现性度量模型的性能,以某航母编队反舰作战为例,采用结构方程模型分析软件LISREL 8.70得到SEM的参数估计值,进而确定两种SEM结构方程。根据该方程进行作战能力评估,结果显示,与线性涌现的SEM相比,非线性模型更接近实际作战能力。     

Performance evaluation of a solarized gas turbine system integrated to a high temperature electrolyzer for hydrogen production

In this paper, the performance of a solar gas turbine (SGT) system integrated to a high temperature electrolyzer (HTE) to generate hybrid electrical power and hydrogen fuel is analyzed. The idea behind this design is to mitigate the losses in the electrical power transmission and use the enthalpy of exhaust gases released from the gas turbine (GT) to make steam for the HTE. In this context, a GT system is coupled with a solar tower including heliostat solar field and central receiver to generate electrical power. To make steam for the HTE, a flameless boiler is integrated to the SGT system applying the SGT extremely high temperature exhaust gases as the oxidizer. The results indicate that by increasing the solar receiver outlet temperature from 800 K to 1300 K, the solar share increases from 22.1% to 42.38% and the overall fuel consumption of the plant reduces from 7 kg/s to 2.7 kg/s. Furthermore, flameless mode is achievable in the boiler while the turbine inlet temperature (TIT) is maintained at the temperatures higher than 1314 K. Using constant amounts of the SGT electrical power, the HTE voltage decreases by enhancing the HTE steam temperature which result in the augmentation of the overall hydrogen production. To increase the HTE steam temperature from 950 K to 1350 K, the rate of fuel consumption in the flameless boiler increases from 0.1 m/s to 0.8 m/s; however, since the HTE hydrogen production increases from 4.24 mol/s to 16 mol/s it can be interpreted that the higher steam temperatures would be affordable. The presented hybrid system in this paper can be employed to perform more thermochemical analyses to achieve insightful understanding of the hybrid electrical power-hydrogen production systems.     

A dual-band multiple-input multiple-output microstrip antenna with metamaterial structure for LTE and WLAN applications

A method to enhance the gain of microstrip dual-band multiple-input multiple-output (MIMO) antenna using partially reflective surface (PRS) layer is introduced and investigated in this paper. The proposed antenna consists of two FR4 substrates. The lower substrate has two radiating patches with parasitic elements that are supplied independently and create the MIMO property of the antenna. The upper substrate which is known as superstrate is arrays of PRS unit cells. The PRS layer printed on either side of a dielectric substrate and causes the antenna gain to increase in both frequency bands. The proposed antenna is appropriate for LTE (2.4–3.1 GHz) and WLAN (5.1–5.8 GHz) applications. The measured values of S₁₁ and S₂₂ parameters of the antenna are less than −10 dB and its FBR and gain are 12.5 dB and 5dBi, respectively. The average half power beam-width (HPBW) is roughly 108^○.     

平板热管散热器传热特性研究及结构优化

本文通过分析平板热管散热器工作原理建立系统热阻模型,计算分析不同结构参数诸如平板热管蒸汽腔厚度,翅片厚度,间距及高度,以及相关外部参数诸如热源尺寸和风速对于传热性能的影响。据此进行相关结构优化计算并提出设计建议。与传热数值模拟结果对比,验证了采用热阻模型计算的准确性,为工程设计提供一定的理论基础。     

柔索牵引式力觉交互机器人控制策略

为了让航天员在没有太空真实环境的地面上模拟太空环境进行虚拟作业训练,设计了一种与虚拟现实（VR）技术相结合的柔索牵引式力觉交互机器人．首先,根据微重力环境中物体的运动特性设计机器人的构型,建立移动平台、驱动单元、人推物体运动过程的动力学模型并进行运动学分析．然后,针对系统冗余驱动及力控制任务,提出一种复合控制策略,即以柔索长度变化为速度控制内环,力的外环控制为力／速混合控制．最后,分别进行单柔索加载和人机系统力觉交互仿真分析,分析结果表明该控制策略可以使柔索驱动单元降低10%的恒力跟随误差并能稳定地跟随余弦力的变化,验证了该控制策略对多余力抑制的有效性．     

Effect of “Ph–NH–CH2–” group on the luminescence properties of sol–gel silica xerogel

The effect of Ph–NH–CH₂– group (Ph: phenyl) on the luminescence properties of silica xerogel by sol–gel method has been investigated. The absorption spectra, excitation spectra and emission spectra of Ph–NH–CH₂– group embedded in the network of silica xerogel have a red shift with increasing the ratios of Ph–NH–CH₂– group in the samples. The relative photoluminescence (PL) intensity of the hybrid silica xerogel sample decreases with increasing the ratios of Ph–NH–CH₂– group. From the complex luminescent centers, the novel luminescence properties have been observed from the hybrid silica xerogel sample containing Ph–NH–CH₂– group.     

Human-object integrated assembly intention recognition for context-aware human-robot collaborative assembly

Human-robot collaborative (HRC) assembly combines the advantages of robot's operation consistency with human's cognitive ability and adaptivity, which provides an efficient and flexible way for complex assembly tasks. In the process of HRC assembly, the robot needs to understand the operator's intention accurately to assist the collaborative assembly tasks. At present, operator intention recognition considering context information such as assembly objects in a complex environment remains challenging. In this paper, we propose a human-object integrated approach for context-aware assembly intention recognition in the HRC, which integrates the recognition of assembly actions and assembly parts to improve the accuracy of the operator's intention recognition. Specifically, considering the real-time requirements of HRC assembly, spatial-temporal graph convolutional networks (ST-GCN) model based on skeleton features is utilized to recognize the assembly action to reduce unnecessary redundant information. Considering the disorder and occlusion of assembly parts, an improved YOLOX model is proposed to improve the focusing capability of network structure on the assembly parts that are difficult to recognize. Afterwards, taking decelerator assembly tasks as an example, a rule-based reasoning method that contains the recognition information of assembly actions and assembly parts is designed to recognize the current assembly intention. Finally, the feasibility and effectiveness of the proposed approach for recognizing human intentions are verified. The integration of assembly action recognition and assembly part recognition can facilitate the accurate operator's intention recognition in the complex and flexible HRC assembly environment.     

基于模糊控制的线导鱼雷组合导引方法

在深入分析线导＋尾流自导鱼雷方位导引和前置点导引方法的基础上，综合方位导引和前置点导引的优点，给出了一种线导鱼雷的组合导引方法。通过引入模糊控制方法，根据目标运动状态和距离远近等信息自适应地调节导引参数，可有效地将鱼雷导引到尾流制导的理想攻击阵位上。仿真结果表明，该方法可以导引鱼雷按照要求入射目标尾流，且具有较好的弹道特性。该智能组合导引律结构简单，易于实现，有一定的工程实践意义。     

Development and performances of a 0.5 kW high-pressure alkaline water electrolyser

The purpose of this research paper is to describe the characteristics and electrochemical performances of a pressurized alkaline water electrolysis short stack (5-cells, 0.5 kW) operated at 80 °C, from atmospheric pressure up to 100 bars. Expanded grids of metallic nickel covered with specific porous catalytic structures have been used as working electrodes. A polysulfone-based diaphragm with a high ionic conductivity has been specifically designed for operation in pressurized alkaline water electrolysis cells. I–V polarization curves have been recorded at current densities up to 1000 mA/cm², at temperatures up to 80 °C and under pressures up to 100 bars. The water electrolysis efficiency of this short-stack has been determined. A specific energy consumption of ca. 4.4–4.5 kWh/Nm³ has been obtained in the high current density range. Durability tests have been performed on the short stack over 1000 h. A limited degradation rate <5 μV/h has been recorded over that period of test.     

Pressure control strategy to extend the loading range of an alkaline electrolysis system

Alkaline electrolysis (AEL) is the most mature electrolysis technology and is widely used in large-scale power-to-gas scenarios. However, the loading range of AEL system is restricted by the minimum load, 10%–40% in general, which prevents system operation during low-load periods. This minimum load is caused by the flammable mixture formed by the impurity crossover and is related to operation conditions such as current and pressure. In this paper, we propose a novel pressure control strategy to extend the loading range of an AEL system by reducing the system pressure at low-load periods while also maximizing the system efficiency. A dynamic impurity accumulation model is established illustrating the flexibility limitation mechanism of the AEL system. Two pressure controllers are designed based on the steady-state and dynamic impurity accumulation model, including an operation curve tracking controller (OCT) and a model predictive controller (MPC). In the case study, both controllers achieve satisfying results under the peak shaving scenario, with an extension of the AEL system's minimum load from 27.5% by the traditional constant pressure controller to 10.5% by the OCT controller and 10% by the MPC controller. This pressure control strategy reduces the electricity abandonment and improves the system economy significantly.