基于混合蚁群算法的异质车队低碳VRP研究

针对货运车辆在配送调度过程中产生大量碳排放的问题，建立模型将多种影响碳排放量的因素协同优化。模型中考虑了不同载重量的异质车队，两个节点之间有多条道路的柔性路径，以及车辆重量随卸货而减少的动态负载等因素，以碳排放量、行驶时间和行驶路程为优化目标，并加入了节点需求时间窗、根据速度变化划分路段、交接和卸货时间的约束。提出了一种混合蚁群算法，利用蚁群算法信息素强度更新方式保持群体记忆性，利用粒子群算法的快速收敛特性增加计算效率。通过随机数值算例的仿真优化与对比分析，验证了算法和模型的有效性。     

基于第三方物流的家具配送开放式车辆路径问题

为了降低家具配送成本,提高物流效率,基于第三方物流配送模式,构建了以总行驶距离最短和车辆数最少为最优目标的开放式车辆路径问题(open vehicle routing problem,OVRP)数学模型,并设计了一个改进的两阶段禁忌搜索算法进行求解,第1阶段求解包含所有客户的TSP(traveling salesman problem)路径来作为第2阶段划分OVRP路径的基础.设计了一个随机动态禁忌表,并将"邻域算子编号"和"邻域交换点对"同时作为禁忌对象,避免了过度禁忌的情况.另外,对5个邻域算子进行了测试,表明采用由点交换、分序点插入、点逆序和前点前向插入这4个算子组成的多邻域结构体效果最佳.经算例测试和文献对比,验证了设计算法的有效性,采用第三方物流配送比自营物流配送更节省成本.     

High-speed,two-dimensional digital image correlation algorithm using heterogeneous (CPU-GPU) framework

Two-dimensional digital image correlation (2D-DIC) is an experimental technique used to measure in-plane displacement of a test specimen. Real-time measurement of full-field displacement data is challenging due to enormous computational load of the algorithm. In order to improve the computational speed, the focus of recent research works has been on the approach of parallelization across subsets within image pairs using graphics processing unit (GPU). But alternate GPU-based parallelization approaches to improve the performance of this algorithm as per the order of data processing have not been explored. To address this research gap, our method utilizes parallelism within a subset as well as across subsets for each computation step in an iteration cycle. A heterogeneous (CPU-GPU) framework in combination with a pyramid-based initial values estimation for subsets (in parallel) is proposed in this work. The precompute steps of the proposed framework are implemented using CPU, whereas the main iterative steps are realized using GPU. It is demonstrated that the overall computational speed of the proposed heterogeneous framework improves by compared to a sequential CPU-based implementation for a pair of gray-scale images with a resolution of pixels. As an important milestone, feasibility to measure deformations in real time ( 1 s) is manifested in this study.     

小议经济型异构播出系统

电视播出系统的稳定性与安全性直接关系到电视播出的效果。结合实践经验,对经济型异构播出系统的构建进行介绍。     

基于5G边缘云的港口统一通信方案研究与实践

5G边缘云具有分布式、灵活组网、快速部署和本地流量分流等优势，在港口等垂直工业领域有很广泛的应用前景，同时对实现港口统一通信也提出了一定的要求。在研究基于5G边缘云的港口统一通信架构的基础上，提出了针对港口现场全域各类要素实现全面感知、支撑自动化业务改造的5G边缘云功能框架。此功能框架能很好地适用于港口场景的有线无线网络融合的统一承载，可作为目前复杂环境下的港口网络统一通信的网络基础设施。最后在某港口码头上对该方案进行了实际验证。     

Mechanism of heterogeneous distribution of Cr-containing dispersoids in DC casting 7475 aluminum alloy

The actual effective partition coefficients of Mg and Cr in a cross-section of a dendrite arm in a direct-chill (DC)-casting ingot of 7475 aluminum alloy are obtained. Meanwhile, by analyzing the microstructure, the mechanism of the heterogeneous distribution of E (Al₁₈Mg₃Cr₂) dispersoids in this DC ingot is revealed. The results show that the actual effective partition coefficients of Mg and Cr are 0.650 and 1.392, respectively, and they describe the heterogeneous distributions of Mg and Cr along the direction of radius of the cross-section of the dendrite arm of the alloy. After homogenization treatment at 470 °C for 24 h, Mg diffuses uniformly, but Cr hardly diffuses. Both the concentrations of Mg and Cr and the sites of heterogeneous nucleation in the alloy are the determinants of the formation of E dispersoids simultaneously. The heat treatment at 250 °C for 72 h provides a large number of the sites of heterogeneous nucleation of the formation of fine E dispersoids that will be formed in the center of the cross-section during the subsequent heat treatment at higher temperature.     

Highly Stable COF‐Supported Co/Co(OH)2 Nanoparticles Heterogeneous Catalyst for Reduction of Nitrile/Nitro Compounds under Mild Conditions

Ordered nanoporosity in covalent organic framework (COF) offers excellent opportunity for property development. Loading nanoparticles (nPs) onto them is one approach to introducing tailor‐made properties into a COF. Here, a COF–Co/Co(OH)₂ composite containing about 16 wt% of <6 nm sized Co/Co(OH)₂ nPs is prepared on a N‐rich COF support that catalyzes the release of theoretical equivalence of H₂ from readily available, safe, and cheap NaBH₄. Furthermore, the released H₂ is utilized for the hydrogenation of nitrile and nitro compounds to amines under ambient conditions in a facile one‐pot reaction. The COF “by choice” is built from “methoxy” functionalized dialdehydes which is crucial in enabling the complete retention of the COF structure under the conditions of the catalysis, where the regular Schiff bonds would have hydrolyzed. The N‐rich binding pockets in the COF ensure strong nP–COF interactions, which provides stability and enables catalyst recycling. Modeling studies reveal the crucial role played by the COF in exposing the active facets and thereby in controlling the activation of the reducing agent. Additionally, via density functional theory, we provide a rational explanation for how these COFs can stabilize nanoparticles which grow beyond the limiting pore size of the COF and yet result in a truly stable heterogeneous catalyst – a ubiquitous observation. The study underscores the versatility of COF as a heterogeneous support for developing cheap and highly active nonnoble metal catalysts.     

Heterogeneous oxidation of indoor surfaces by gas‐phase hydroxyl radicals

We investigate heterogeneous oxidation kinetics of monolayer‐thick, surface‐sorbed organics, namely di‐n‐octyl phthalate (DnOP) and palmitic acid (PA), with gas‐phase OH. The pseudo‐first order rate constants for organic loss at OH concentrations of 1.6 × 10⁸ molecules/cm³ are: (2.3 ± 0.1) × 10^?4 to (4.8 ± 0.8) × 10^?4 s^?1, and (1.3 ± 0.5) × 10^?4 s^?1 for DnOP and PA, respectively. Films developed in indoor office environments over a few weeks are also oxidized using the same OH concentration. Heterogeneous decay rate constants of mass signals from these films, attributed to phthalates (MW = 390.6) and to PA, are similar to those for the single‐component films, ie, (1.9 ± 0.4) × 10^?4 to (3.4 ± 0.5) × 10^?4 s^?1, and (1.1 ± 0.4) × 10^?4 s^?1, respectively. These results suggest that the lifetimes for OH heterogeneous oxidation of monolayer‐thick indoor organic films will be on the timescale of weeks to months. To support this argument, we present the first analysis of the mass transfer processes that occur when short‐lived gas‐phase molecules, such as OH, are taken up by reactive indoor surfaces. Due to rapid chemical production, the diffusion limitation to mass transfer is less important for short‐lived molecules than for molecules with little chemical production, such as ozone.     

非均质煤层瓦斯分布特征及钻孔抽采瓦斯运移规律研究

为了提高煤矿瓦斯抽采率，节约瓦斯抽采时间，分析了非均质煤层瓦斯分布特征及钻孔抽采瓦斯运移规律，采用透气性系数研究了非均质煤层瓦斯压力分布特点；分析了非均质煤层单钻孔瓦斯压力分布、原始瓦斯压力、原始透气性系数对有效抽采半径的影响。研究对指导现场瓦斯抽采以及促进煤矿安全生产具有重要意义。     

Refreshing doping concept in perovskite piezoceramics: Composite modulation hidden behind lattice substitution

Chemical doping is favored by academia as well as industry because of its effectiveness in attuning to the properties of piezoceramics. Although significant progress has been made, few reports have focused on the role and overall effect of substituted ions. Based on the tendency of special crystals such as ZnO toward spontaneous growth, this study applies the concept of composite modulation to conventional doping; the CuO-modified 0.2Pb(Zn_1/3Nb_2/3)O₃-0.8Pb(Zr_1/2Ti_1/2)O₃ (PZN-PZT) system has been used for verification of the proposed method. The results show that copper ions enter the perovskite matrix to specifically replace the zinc ions causing lattice distortion and increasing the rhombohedral phase (RP) content. Furthermore, the substituted zinc ions enter the grain boundaries and grow into a secondary phase ZnO, based on their spontaneous-growth tendency; the induced heterogeneous interfacial effects lead to refinement of the domain size and enhancement of the interface polarization. The combined effects of the lattice substitution and composite modulation promote a significant improvement in the piezoelectric coefficient of the CuO-modified PZN-PZT system compared with its pure counterpart. The dual function of doping demonstrated in this study is expected to further contribute to the preparation and performance improvement of the other piezoelectric composites.