以“能量集”助推学生主体学习胜任力的个案研究

培养学生的主体学习胜任力,将为学生形成持续性、有效性学习提供可能。文章分析如何采用“能量集”策略,从反思力、跃迁力、自决力、规划力、执行力和沟通力等不同维度助推学生主体学习胜任力,并以个案研究的方式阐述了实践的过程、成果和思考。

基于多尺度子带能量集特征的膛口波识别方法

面向实际复杂环境下的枪声探测应用,提出一种基于多尺度子带能量集特征的膛口波识别方法。采用一组低频子带滤波器增强膛口波信号,通过膛口波检测和波峰搜索确定候选膛口波的起点位置,并基于该起点以嵌套方式截取候选膛口波及其各子带分量的多尺度数据片段,用各片段数据的短时能量和能量比构成多尺度子带能量集特征输入支持向量机和k近邻分类器,进行膛口波和非膛口波识别。对372段外场实录枪声数据进行数值实验,结果表明:所提方法对膛口波识别的查全率、查准率均高于93%,加权调和平均高于0. 95;两种分类器下的识别结果无明显差别,但所用特征维数和计算耗时却远低于常用的离散小波方法,更接近实际应用需求。

集群式岸电能量路由器供能精细化就地管控策略

传统的能量路由器能量管理策略未考虑多台设备之间的柔性互联关系,且在港口应用中港机负荷的冲击性和新能源发电的波动性,使区域电网的可靠供电和经济运行面临挑战。为此,基于模糊逻辑控制提出了一种适用于集群式岸电能量路由器的供能精细化就地管控策略。该方法考虑了互联岸电能量路由器之间输出功率的耦合影响,并依据并网模式下可能的功率流向制定了保证电力用户经济效益的模糊控制规则,使储能输出电流根据电池荷电状态(state of charge, SOC)、电网电价以及各台岸电能量路由器净输出功率的变化进行动态调整。该方法计及了互联系统间的协同作用,构建了互联系统间各端口传输功率关系,有利于分布式能源跨台区协同消纳,且不需要上层调度控制,减少了对通信的依赖。仿真结果验证了所提控制策略的有效性和可行性。

能量有效的最小连通支配集近似算法

针对无线自组传感器网络中有效路由提出的一种能量有效的最小连通支配集近似算法EEMCDS(Energy Effi cientminimumconnecteddominatingset) ,路由搜索主要集中在连通支配集内。本文提出一个能量有效的简洁有效的分布式算法 ,该算法根据各节点所具有的能量不同 ,优先选择高能量的节点作为连通支配集节点 ,可以有效地延长网络寿命。实例仿真表明在连通支配集节点数量较少的情况下 ,高能量的节点在支配集中所占的比例也是较高的。

考虑电网约束的多类型分布式资源集群能量交易与利益分配方法

近年来,智能电网中渗透了越来越多的分布式灵活性资源,例如电动汽车和可再生能源,促进了电网从被动配电网向主动配电网的快速转化。然而,这一过程同时给系统的运行和优化带来了巨大的挑战。本文研究了考虑多类型分布式资源集群能量管理框架。该框架旨在使分布式资源集群的总成本最小化的同时优化集群间能量交易过程中所产生的电力损失。为了确保配电网的可靠和安全运行,引入了相关电网约束。因此在所提出的框架在能量交易过程中采用纳什议价理论进行收益分配,可以获得互惠公平的解决方案,鼓励消费者参与能量交易。最后,通过改进的33节点配电网中的多个算例,说明了该能源管理框架提高了能量交易的灵活性、经济性和安全性,具有一定的有效性和优越性。

ZigBee无线组网信息系统在低压用户集中抄表中的应用

针对供电企业的工作实际,对如何解决低压居民用户电能量集抄的问题进行探讨,阐述了系统建设的主要思路和相关技术方法,并作了分析。

影响电量集抄系统抄表成功率的常见故障分析及对策

电能量集抄系统在电力系统中得到广泛应用,如何提高远方抄表的成功率是电能量集抄系统的重要问题,本文结合聊城供电公司现有电能量集抄系统的应用情况,分析了实际使用中影响抄表成功率的主要原因,并提出了行之有效的对策。

双复射孔器的原理、应用及前景展望

本文以双复102型射孔器的设计为例，介绍双复射孔器原理及应用。双复射孔器的原理就是利用复式枪结构实现无用能量的分解；利用复式弹及全封闭结构实现有用能量的集束释放，采用复式枪可以分解爆炸冲击波对射孔枪的作用，较大幅度地减薄枪壁的厚度，为扩大枪体外径和内径提供条件。扩大枪的外径可以减小射流在穿透井液时的损耗，提高射孔弹穿深，还可以使套管上的孔眼分布趋于均匀一致，有利于减小射孔对套管的损伤；扩大射孔枪的内径可以提高射孔弹的内炸高，达到提高穿深的目的，复式射孔弹缩短了射孔弹峰压与火药燃气峰压的时差，加速了火药燃气脉冲沿射流方向同轴加载的过程，实现了能量的集束释放，提高了火药的效率，射孔弹采用肩台式装药，进而增强了扩孔造缝能力。双复射孔器设计上具有独到之处，提高了射孔器的各项主要技术指标，为中、低渗透油层的开发提供了更有效的技术手段，是新井（或新层）射孔首选的射孔器，具有广泛的推广应用价值。139.7mm以上的各种套管井中使用的射孔器都可以按照这种原理进行设计。

An automatical infill shot method for uniform imaging of target layer

Seismic imaging quality is critical to describing reservoirs. There are many methods that can improve imaging quality; some rely on advanced processing means, whereas others rely on changing the field acquisition methods. However, most of the acquisition methods focus on improving imaging by using infill shots without considering the target-layer illumination energy. Moreover, total infill shooting greatly increases the acquisition cost. In this paper, we present a new method for maximizing the contribution to the target shadow area illumination by automatic local infill shooting. Thus, we designed 2D and 3D models and obtained the depth migration section by forward modeling, infill shots, depth migration, etc. The model results also show that by choosing the most appropriate number of shot points, we can enhance the shadow area energy and improve the target-layer imaging quality at low cost.

基于宽频-多模态的复合俘能器的解析模型与实验研究

为提高单频压电振动俘能器的能量转换效率和工作频带,结合压电和电磁能量转换机制,提出了一种新的混合俘能器系统。该系统由PZT悬臂梁、弹性悬挂磁铁块、粘附于悬臂梁末端磁铁块及谐振器等组成,引入谐振器及磁铁可实现增加系统模态数量和非线性。基于此混合振动俘能器建立了改进型连续体机电耦合解析模型,并由龙格-库塔算法进行了求解。在此基础上,研制了振动俘能器原理样机,并搭建了实验系统,通过实验和解析评估方法完成了单一式和复合式俘能器性能比对和评估;研究表明,所研究的混合型振动俘能器相对常规振动能量俘集原理可实现较宽的频率范围及多模态振动能量俘集,且能量俘集效率明显提高,具有较好的应用前景。

一种改进的无线传感器网络EEMCDS算法

针对无线传感器网络中的有效路由,提出了一种改进的,基于最小连通支配集的能量有效算法IEEMCDS(I mprovedEnergy-Efficient Mini mum Connected Dominating Set).路由搜索主要集中在连通支配集内,通信量小.该算法是一个能量有效的分布式算法,在维护最小连通支配集时,充分考虑了节点的能量问题,优先选择高能量的节点充当连通支配集节点,提出了支配节点能量最小阈值调整法,可以有效地延长网络寿命.实例仿真表明在改进算法的连通支配集中,高能量的节点在支配集中一直占有较高的比例,从而有效地延长了网络寿命.

GEOTHERMAL RESOURCES ASSESSMENT AND NUMERICAL SIMULATION IN TUANBO REGION

This paper mainly deals with the reservoir on the heat and mass transfer and mass and energy balance in a geothermal field.On the basis of briefing the general characteristics of the reservoir and the supposition of the reservoir modeling,the paper emphasizes the mathematical descriptions of hydra thermal transportation and convection by two methods according to the different models,such as lumped parameter model and distributed parameter model.It is effective to use these models in simulating the heterogeneous,and anisotropical fracture reservoir for the designed lifetime of 15 years.

耦合神经元集群活动的能量演变和数值模拟

基于我们提出的能量编码原理[1,2],在这篇文章中我们给出了大脑皮层神经元集群的总能量函数的动力学模型。这个模型的特点是在耦合神经元集群内。

Pedestrian walking characteristics at stairs according to width change for application of piezoelectric energy harvesting

This work aims at finding pedestrian walking characteristics at U-type stairs according to the width change of stairs and appropriate spot for installing piezoelectric energy harvesting.The number of pedestrian at two kinds of stairs(one is stairs with 1.5 m in width and the other is stairs with 3 m in width) was estimated by calculating the number of steps on the stairs by a zone which is divided into 30 cm×30 cm.The result shows high density in the middle in the case of narrow stairs but traffic is concentrated on stair inside(pillar side) in stairs with large width.In conclusion,the location for installation of piezoelectric energy harvesting system should be considered differently on stairs width and the number of installation depends on total expected traffic and the expected traffic for a device.

Optimal Spectrum Sensing in Energy Harvesting Cognitive Radio Systems

In this paper,we consider a cognitive radio system with energy harvesting,in which the secondary user operates in a saving-sensing-transmitting(SST) fashion.We investigate the tradeoff between energy harvesting,channel sensing and data transmission and focus on the optimal SST structure to maximize the SU's expected achievable throughput.We consider imperfect knowledge of energy harvesting rate,which cannot be exactly known and only its statistical information is available.By formulating the problem of expected achievable throughput optimization as a mixed-integer non-linear programming one,we derive the optimal saveratio and number of sensed channels with indepth analysis.Simulation results show that the optimal SST structure outperforms random one and performance gain can be enhanced by increasing the SU's energy harvesting rate.

Sensing Time Optimization in Energy-Harvesting Cognitive Radio with Interference Rate Control

In this paper,an energy-harvesting cognitive radio(CR) is considered,which allows the transmitter of the secondary user(SU) to harvest the primary signal energy from the transmitter of the primary user(PU) when the presence of the PU is detected.Then the harvested energy is converted into the electrical power to supply the transmission of the SU at the detected absence of the PU.By adopting the periodic spectrum sensing,the average total transmission rate of the SU is maximized through optimizing the sensing time,subject to the constraints of the probabilities of false alarm and detection,the harvested energy and the interference rate control.The simulation results show that there deed exists an optimal sensing time that maximizes the transmission rate,and the maximum transmission rate of the energy-harvesting CR can better approach to that of the traditional CR with the increasing of the detection probability.

Energy Efficiency Optimization in Relay-Assisted Networks with Energy Harvesting Relay Constraints

In this paper we consider data transmission in a decode-and-forward(DF)relay-assisted network in which the relay is energy harvesting(EH) powered while the base station(BS) is power-grid powered.Our purpose is to maximize the BS's energy efficiency(EE) while making full use of the relay's renewable energy and satisfying the specific average throughput requirements.In contrast to existing literature on energy harvesting system which only considers the radio transmission power,we take the static circuit power into account as well.We formulate the EE optimization problem and prove that the EE of the BS and relay are both quasiconvex in the instantaneous transmission rate.Then we divide the complex optimization problem into two point-to-point link level optimization parts and propose an energyefficient resource allocation(EERA) scheme in which power control and sleep mode management are jointly used.The simulation results demonstrate that EERA may achieve good energy saving effects.We also compare the EE of an energy harvesting relay system with a power-grid powered one and provide more insight into the EE problem of energy harvesting relay system.

Power Allocation for Energy Harvesting in Wireless Body Area Networks

Wireless Body Area Networks(WBANs) are expected to achieve high reliable communications among a large number of sensors.The outage probability can be used to measure the reliability of the WBAN.In this paper,we optimize the outage probability with the harvested energy as constraints.Firstly,the optimal transmit power of the sensor is obtained while considering a single link between an access point(AP) located on the waist and a sensor attached on the wrist over the Rayleigh fading channel.Secondly,an optimization problem is formed to minimize the outage probability.Finally,we convert the non-convex optimization problem into convex solved by the Lagrange multiplier method.Simulations show that the optimization problem is solvable.The outage probability is optimized by performing power allocation at the sensor.And our proposed algorithm achieves minimizing the outage probability when the sensor uses energy harvesting.We also demonstrate that the average outage probability is reduced with the increase of the harvested energy.

Energy Efficient Resource Allocation in Timesharing Multiuser Systems with Hybrid Energy Harvesting Transmitter

An energy effi cient resource allocation scheme in timesharing multiuser system with a hybrid energy harvesting transmitter is studied in this paper. Specially, the operation energy of system is supplied by constant energy and energy harvesting, which harvests energy from external environment. Our goal is to maximize the energy effi ciency of timesharing multiuser systems by considering jointly allocation of transmission time and power control in an off-line manner. The original nonconvex objective function is transformed into convex optimization problem via the fractional programming approach. Then, we solve the convex problem by Lagrange dual decomposition method. Simulation results show that the proposed energy efficient resource allocation scheme has a better performance than the scheme which decomposes optimization problem into two parts(power allocation, time allocation) to solve iteratively.

Finite element simulation on percolation of low permeability reservoir with permeability anisotropy

In low permeability porous media which permeability anisotropy is ubiquitous,the percolation of fluid no longer follows linear Darcy’s Law.Oil-water two phase flow equation of low permeability reservoir with permeability anisotropy is established based on generalized Darcy’s law and starting pressure gradient,corresponding finite element program is developed and simulated based on the Finite Element Program Generator system (FEPG).The results show that energy-gathering exists in the flow event of flowing area front in low permeability reservoir.In the process of energy-gathering,the flow velocity changed little but increased rapidly as soon as the pressure gradient exceeded the starting pressure gradient of the reservoir,then gradually stabilized.The greater the starting pressure gradient is,the greater the near wellbore pressure drop is,the smaller the area influenced by the reservoir pressure changes caused by water injection and oil recovery.The greater the starting pressure gradient is,the lower the water saturation in same point of the reservoir is,the smaller the water flood swept area is.There will be more difficulties in water injection to the same extent.