萍水河水质空间分布特征及水质评价对比研究

流域水质直接关系到人体健康和生态安全。以萍水河向阳湖至何雁桥段为研究对象,分析其水质空间特征,综合4种方法进行水质评价,进一步利用多元统计和级别差方法对比分析水质评价结果。结果表明：1)COD、NH₃-N、TP和TN的最高浓度位于赤山桥处;上游(向阳湖-桥头村)和下游(赤山桥-何雁桥)总体水质较好,部分采样点TN、Fe和Mn轻度超标,污染程度明显弱于中游(桥头村-赤山桥)。2)最差水质级别均为Ⅴ类或劣Ⅴ类水,污染程度属严重污染及以上;单因子评价法确定总氮(TN)为首要污染指标;主成分分析法确定2个主成分,可解释为营养盐污染指标和地质沉积环境指标。3)4种方法两两之间呈显著正相关,相关系数为0.937～0.994,但水质级别表现出明显的差异性;级差法结果表明,3种综合水质评价方法的水质级别顺序为：内梅罗污染指数法<综合污染指数法<主成分分析法。研究成果可为流域水质评价工作和研究提供参考,同时为流域水资源开发利用和水环境保护及综合治理提供科学依据。     

LiCoxMnyNi1-x-yO2电极材料的研究进展

LiCoxMnyNi1-x-yO2电板材料是当前锂离子电池新一代正板材料的研究热点之一。介绍了锂离子电池正板材料LiCoxMnyNi1-x-yO2的结构与性能,总结了制备方法、制备工艺参数对其性能的影响,对LiCoxMnyNi1-x-yO2的掺杂改性作了综述,并对锂离子电池正板材料的发展方向作了展望。     

热固性树脂耐腐蚀性能评估及其应用(Ⅱ)耐化学腐蚀评估及标准方法的比较与应用案例

论述了热固性树脂耐化学腐蚀评估,耐化学腐蚀性能的欧洲标准(EN13121-2)与DSM复合材料树脂公司方法(ASTMC 581)的实验比较以及长期案例验证。     

双色激光产生太赫兹辐射的调控机理研究

采用双色激光在气体介质中诱导产生太赫兹波的数值模拟方法,深入分析了各种激光参数对双色激光场产生太赫兹波的影响,目的是优化参数以实现太赫兹波辐射能量的最大化。模拟计算表明,双色激光的波长、相对相位、激光脉冲宽度等对瞬态电流和太赫兹能量都有调控作用,并且具有不同的规律性。此外,还通过分析激光电场、电子密度、光电流等相关因素,对双色激光场产生太赫兹波的物理机理进行了解释。该研究为在不同激光激发条件下提高太赫兹波辐射强度,提供了详尽的参数优化分析和理论支持,对后续大幅增强太赫兹辐射效率具有重要意义。     

基于LwIP协议栈的校园环境监测平台设计

为了实现对校园人口密集场所中多种环境质量指标数值的实时监测,设计了一种基于LwIP协议栈的校园环境监测平台。平台采用模块化设计,分为局域环境监测系统、数据处理转换中心与云平台,实现对各环境指标数据的采集、处理、传输、存储与显示。局域环境监测系统采用ESP8266模块开发,各模块间通过WiFi组成星型网络,实现多节点同时采集温湿度、CO、CO2、TVOC等指标数据,数据处理转换中心通过STM32芯片移植LwIP协议栈设计了一款串口转以太网网关,实现通过IPv6网络将数据发送至云平台,云平台可存储数据并以图形化的形式进行展示。     

自适应机翼的发展现状及其关键技术研究

综述了近二十年来国内外自适应机翼技术的研究现状以及该领域需要解决的关键技术,对未来这一技术的发展和应用进行了展望。     

Intelligent Video Traffic Smooth Mechanism for Multimedia Communication

A principal challenge in supporting real-time video services over ATM is the need to provide synchronous play-out in the face of stochastic end-to-end network delays. In this paper, an intelligent traffic smooth mechanism ( ITSM ) is proposed to meet the continuity requirement which is composed of a back-propagation neural network ( BPNN ) traffic predictor, a play-out buffer, and a fuzzy neural network ( FNN ) based play-out rate determinator. The BPNN traffic predictor online predicts the mean packet rate of the traffic in the future interval ( FI ) and the FNN is designed to adaptively determinate the play-out time according to the number of packets in the buffer and the traffic character predicted. Simulation results show that compared to the window mechanism, ITSM achieves high continuity with accepted delay. Furthermore, ITSM can be adaptively modified to meet the QoS of different kinds of services by FNN parameter training.     

Experimental Study of the Vibration Phenomenon of Compressor Rotor Blade Induced by Inlet Probe Support

An experimental investigation was conducted in order to understand the installation effects of inlet measurement probes on the vibration characteristics of the ...     

冷连轧机的动态变规格过程的计算机仿真

针对某厂的5机架冷连轧机的动态变规格过程进行仿真研究.首先建立其动态变规格时的仿真系统,分析了其动态变规格过程的实现方案.然后在此基础上对其变规格过程进行了仿真分析,指出了现在方案中的问题,提出了一种改进方案,并通过进一步的仿真说明了改进方案的可行性和有效性.     

HULL GESTURE AND RESISTANCE PREDICTION OF HIGH-SPEED VESSELS

Since trim and sinkage are significant while vessels are advancing forward with high speed, the predicted vessel resistance based on restrained model theory or experiment may not be real resistance of vessels during voyage. It is necessary to take the influence of hull gesture into account for oredicting the resistance of high-speed ship. In the present work the resistance problem of high speed ship is treated with the viscous flow theory, and the dynamic mesh technique is adopted to coincide with variation of hull gesture of high speed vessel on voyage. The simulation of the models of S60 ship and a trimaran moving in towing tank with high speed are conducted by using the above theory and technique. The corresponding numerical results are in good agreement with the experimental data. It indicates that the resistance prediction for high speed vessels should take hull gesture into consideration and the dynamic mesh method proposed here is effective in calculating the resistance of high speed vessels.