基于蓝牙的公交自动报站系统的设计与实现

将ARM技术与蓝牙技术相结合,设计了一款公交自动报站装置,阐述了ARM微处理器和蓝牙模块的硬件设计思想与软件实现方案.本系统通信稳定,抗干扰能力强.可在公交系统中广泛使用,有效提高乘车安全与舒适性.     

Dynamic Multiple-Fault Diagnosis With Imperfect Tests

In this paper, we consider a model for the dynamic multiple-fault diagnosis (DMFD) problem arising in online monitoring of complex systems and present a solution. This problem involves real-time inference of the most likely set of faults and their time-evolution based on blocks of unreliable test outcomes over time. In the DMFD problem, there is a finite set of mutually independent fault states, and a finite set of sensors (tests) is used to monitor their status. We model the dependence of test outcomes on the fault states via the traditional D-matrix (fault dictionary). The tests are imperfect in the sense that they can have missed detections, false alarms, or may be available asynchronously. Based on the imperfect observations over time, the problem is to identify the most likely evolution of fault states over time. The DMFD problem is an intractable NP-hard combinatorial optimization problem. Consequently, we decompose the DMFD problem into a series of decoupled subproblems, one for each sample epoch. For a single-epoch MFD, we develop a fast and high-quality deterministic simulated annealing method. Based on the sequential inferences, a local search-and-update scheme is applied to further improve the solution. Finally, we discuss how the method can be extended to dependent faults.     

The Edge Effects Boosting Hydrogen Evolution Performance of Platinum/Transition Bimetallic Phosphide Hybrid Electrocatalysts

Platinum (Pt) is regarded as a promising electrocatalyst for hydrogen evolution reaction (HER). However, its application in an alkaline medium is limited by the activation energy of water dissociation, diffusion of H⁺, and desorption of H*. Moreover, the formation of effective structures with a low Pt usage amount is still a challenge. Herein, guided by the simulation discovery that the edge effect can boost local electric field (LEF) of the electrocatalysts for faster proton diffusion, platinum nanocrystals on the edge of transition metal phosphide nanosheets are fabricated. The unique heterostructure with ultralow Pt amount delivered an outstanding HER performance in an alkaline medium with a small overpotential of 44.5 mV and excellent stability for 80 h at the current density of −10 mA cm⁻². The mass activity of as-prepared electrocatalyst is 2.77 A mg⁻¹_Pt, which is 15 times higher than that of commercial Pt/C electrocatalysts (0.18 A mg⁻¹_Pt). The density function theory calculation revealed the efficient water dissociation, fast adsorption, and desorption of protons with hybrid structure. The study provides an innovative strategy to design unique nanostructures for boosting HER performances via achieving both synergistic effects from hybrid components and enhanced LEF from the structural edge effect.     

Visible light-driven superoxide generation by conjugated polymers for organic synthesis

Nano Research - Benefiting from their unique delocalized electronic structure, conjugated polymer-based semiconductors are widely applied in the fields of organic electronics, sensors, and...     

某火控雷达俯仰同步传动机构的改进设计

针对某火控雷达俯仰同步传动机构的回差精度不能满足使用要求,经过理论分析与实践验证提出了可行的改进方案.     

浅析当代航站楼建筑设计中的结构因素

机场航站楼是当今世界上最复杂、最引人注目的建筑之一,它往往被人们视为一个国家或地区的象征.在航站楼建筑的设计过程中,结构形式是建筑师需要加以认真考虑的关键性因素之一,因为它对航站楼建筑造型、内部空间、造价工期等具有重大影响.除了承担荷载等基本结构功能外,恰当的结构形式也体现出建筑设计上的美感,成功的航站楼设计是建筑美学与结构美学有机结合的结果.     

A Lagrangian Relaxation Algorithm for Finding the MAP Configuration in QMR-DT

The quick medical reference decision-theoretic (QMR-DT) network is a large two-layer Bayesian network (BN) [consisting of 571 diseases (ldquofailure sourcesrdquo) and 4075 findings (ldquotest outcomesrdquo)] based on expert and statistical knowledge in internal medicine. The maximum a posteriori (MAP) diagnosis (configuration) based on QMR-DT constitutes an intractable inference problem for all, but a small set of, cases. Consequently, we consider near-optimal algorithms for finding the most likely set of diseases given a set of findings. A computationally efficient algorithm that can handle cases with hundreds of positive findings, i.e., the Lagrangian relaxation algorithm (LRA), is presented. By relaxing the original problem via a set of Lagrange multipliers, the LRA generates an upper bound for the objective function. The near-optimal diagnosis (configuration) is found by minimizing the duality gap via a subgradient method. Numerical experiments show that the LRA is promising in achieving highly accurate diagnosis, and that it is computationally very efficient in solving MAP configuration problems in large and dense two-layer BNs with noisy-OR (BN2O) nodes and containing undirected loops (cycles), such as the QMR-DT network.     

机织人工气管的性能分析

采用多层和多重结构设计思路,研制出一种纬二重结构机织人工气管.通过径向压缩、径向拉伸等力学性能测试,并以针织人工气管为参照,分析机织人工气管的特性,为进一步试验应用莫定基础.     

氨基苯甲醚废水的治理

用絮凝剂（PFS）处理难降解的对（邻）氨基苯甲醚生产废水,絮凝处理后可使BOD5与CODCr从0．084提高到0．155,然后再经生化处理,处理时回用部分循环水经活性污泥法7d处理后,原废水CODcr从6024mg／L降到147mg／L。