1961—2018年吉林省水稻低温冷害时空变化特征

为了研究吉林省水稻低温冷害时空演变规律,采用水稻生长发育和产量形成气象影响模式,判定吉林省1961—2018年水稻障碍型和延迟型冷害,利用数理统计方法分析水稻低温冷害时空变化特征。结果表明:1961—2018年吉林省水稻障碍型和延迟型低温冷害发生站数比呈降低趋势,障碍型低温冷害主要以轻度冷害为主,中度次之,重度最少。重度延迟型冷害发生站数比高于轻度和中度冷害。障碍型冷害发生站数比在1981—1990年最高,延迟型冷害发生站数比在1971—1980年最高。吉林省水稻障碍型低温冷害发生频率呈由西向东逐渐升高的趋势,20世纪90年代之后,冷害主要分布在东部。延迟型冷害发生频率也由西向东逐渐上升,但轻度和中度冷害主要集中分布在中西部,重度冷害主要集中在东部。研究成果可为吉林省合理搭配不同熟性的水稻品种,充分利用热量资源,抵御低温冷害提供保障。     

Theoretical Research on Characteristics of Polarization Controller Basedon a Fiber Recirculating Delay Line with a Twisting-Fiber Device Introduced

The transformation characteristics of the controller based on a fiber-recirculating delay line in which the twisting-fiber device is introduced are analyzed by the useof coupled-mode and matrix optics theory,the Jones matrix representing this controller is obtained,and the effect of twisting fiber ori the polarizdtion characteristics of this controller is analyzedtheoretictically.     

基于TransModeler软件的公交信号优先模型研究

随着公交优先思想的逐渐被接受,作为实现公交优先的主要方式——公交信号优先自然被提上议程。针对大中城市道路交通拥堵、公交运行缓慢等状况,应用微观交通仿真软件TransModeler建立路网车辆运行模型。以哈尔滨市第5路公交为实例,提出公交信号优先方案,应用TransModeler对其进行仿真。通过仿真结果对方案实施前后各路段的交通流运行状况的评价,证明论文提出的方案具有一定的科学实效性。同时表明应用TransModeler软件可以快速、有效的实现各个路网优化方案的对比,节省繁琐数据输入的时间,仿真输出数据简单明了,对今后公交线网优化有很大的帮助。     

Analysis of the characteristic on HCCI autoignition and combustion process of diisobutylene

The homogeneous charge compression ignition (HCCI) characteristics of diisobutylene are studied numerically. Numerical results are in accord with the corresponding experimental data. The influence of some key parameters such as initial pressure, equivalence ratio and constituent on autoignition characteristics is discussed and combustion characteristics of diisobutylene in HCCI engine are analyzed. The results indicate that the ignition delay decreases with the increase of pressure and equivalence ratio. The maximum temperature increases with the rise of equivalence ratio, but it does not change with the variation of initial pressure. The 1 pentene isomer ignites significantly faster than the 2 pentene isomer and the ignition delay for the blend directly depends on the proportions of each isomer. It can be found that diisobutylene shows the single stage autoignition. The maximum heat production rate of the 2 pentene is lower than that of 1 pentene, but the 2 pentene still provides good power performance.     

The compensation method for the random time-delay of the feedbackchannel and the forward channel in the networked control system

An improved predictive control method is presented to compensate the random time delay in the networked control system. The feedback time delay is compensated by predictive controller based on softened increment input strategy. The forward time delay is unknown for controller, so an extra feedback loop is added to compensate the delay by estimating the error between the actual control signal effected on plant and the output of controller in historical moment. For the controlled system with unknown or slowly varying parameters, the networked feedback correction algorithm is discussed based on a modified recursive least-squares identi cation algorithm. The system stability is analyzed and the simulation results show that the time delay in the networked control system can be accurately compensated. The excellent network performance is ensured with this strategy.     

时间标度上的一类时滞动力微分方程的非振动性

本文在时间标度上研究了一阶时滞动力微分方程的非振动性,得到了该方程解的一些性质。     

广义时滞控制系统的能控性

研究了广义时滞系统的能控性,给出其能控的充要条件。     

FY-2C气象卫星延时云图的校正及实现方法

应用非线性插值法对FY-2C静止气象卫星数据中提供的简化网格数据进行近似插值计算.从计算结果看,使用非线性插值法对延时云图的校正效果较为理想,像点定位后扫描列的形状为一条平滑的曲线,基本实现了风云二数据的图像定位,为遥感数据的参数反演和针对性分析做了铺垫.     

具有年龄结构的脉冲时滞捕食-被捕食模型的全局吸引和持久性

研究了与害虫管理相关的一类捕食者具有脉冲扰动,食饵具有年龄结构的时滞捕食-被捕食模型,运用脉冲微分方程的比较定理以及时滞微分方程的基本理论,证明了害虫灭绝的周期解全局吸引、系统持久的充分性条件,同时得到了系统所有解的有界性．