Comparison of up ladder type and terraced type normalizing heat treatments of heavy cylinder

Because of the mixed grain and coarse grain structure, the long heat treatment cycle and large energy conservation in the heavy cylinder heat treatment process, the up ladder type and terraced type normalizing heat treatment of heavy cylinder after rolling were put forward. The microstructure and mechanical properties of 2.25Cr1Mo0.25 V steel after the up ladder type normalizing, terraced type normalizing and isothermal type normalizing were studied. Experimental results show that： 1） For the grain refinement, the twice terraced type normalizing is better than the up ladder type and isothermal type normalizing, and the average grain size is 18 μm; 2） The yield strength, tensile strength and-30℃ charpy impact energy after twice terraced type normalizing are 681 MPa, 768 MPa and 181 J, respectively, and the mechanical properties are better than those of the up ladder type and isothermal type normalizing; 3） Compared with the isothermal type normalizing, the holding time of terraced type normalizing can be shortened by 30%, which greatly reduces the energy consumption.

Effect of phase fluctuation on Hopf bifurcation in a ladder type atomic system

Hopf bifurcation inducing lasing without inversion has been analyzed by taking into account the effect of phase fluctuation in the driving field based on a closed three level ladder-type atomic model. It is shown that due to the phase fluctuation of the driving field, the necessary threshold increases significantly. Furthermore the area domain to get lasing without inversion decreases as the driving field's linewidth increases.

Effects of spontaneously induced coherence on absorption of a ladder-type atom

This paper investigates the effects of spontaneously induced coherence on absorption properties in a nearly equispaced three-level ladder-type system driven by two coherent fields. It find that the absorption properties of this system with the probe field applied on the lower transition can be significantly modified if this coherence is optimized. In the case of small spontaneous decay rate in the upper excited state, it finds that such coherence does not destroy the electromagnetically induced transparency （EIT）. Nevertheless, the absorption peak on both sides of zero detuning and the linewidth of absorption line become larger and narrower than those in the case corresponding to the effects of spontaneously induced coherence; while in the case of large decay rate, it finds that, instead of EIT with low resonant absorption, a sharp absorption peak at resonance appears. That is, electromagnetically induced absorption in the nearly equispaced ladder-type system can occur due to such coherent effects.

Complete eigenmode analysis of a ladder-type multiple-gap resonant cavity

A theoretical model is developed for calculating the eigenmodes of the multi-gap resonant cavity. The structure of concern is a kind of ladder-type circuit, offering the advantages of easy fabrication, high characteristic impedance （R/Q）, and thermal capacity in the millimeter wave to THz regime. The eigenfunction expansion method is used to establish the field expressions for the gaps and the coupling region. Then, the match conditions at the interface are employed, which leads to a group of complicate boundary equations in the form of an infinite series. To facilitate the mathematical treatments and perform a highly efficient calculation, these boundary equations are transformed into the algebraic forms through the matrix representations. Finally, the concise dispersion equation is obtained. The roots of the dispersion equation include both the axial modes in the gaps, which include the fundamental and the high-order modes, and the cavity modes in the coupling region. Extensive numerical results are presented and the behaviors of the multi-gap resonant cavity are examined.

Population transfer by femtosecond laser pulses in a ladder-type atomic system

The population transfer in a ladder-type atomic system driven by linearly polarized sech-shape femtosecond laser pulses is investigated by numerically solving Schr6dinger equation without including the rotating wave approximation （RWA）. It is shown that population transfer is mainly determined by the Rabi frequency （strength） of the driving laser field and the chirp rate, and that the ratio of the dipole moments and the pulse width also have a prominent effect on the population transfer. By choosing appropriate values of the above parameters, complete population transfer can be realized.

In Vivo Testing of Canine Prosthetic Femoral Components with HA-Ti Ladder-type Coating on Vacuum Plasma-sprayed Ti Substrate

Summary： The purpose of the present study was to observe the structure and functional change of the bone-coating-prosthesis interface in vivo and to evaluate the histocompatibility of self-made prosthetic femoral components in the body and the degree of their bonding with the surrounding bone tissues as well as their stability. Six mature beagle dogs underwent bilateral hip replacement with prosthetic femur components. Three groups were established in terms of different coating of prothesis （four joints in each group）： atmosphere （A） plasma-sprayed pure titanium （Ti） prosthetic joint with hydroxyapatite （HA） coating （HA＋Ti＋A group）; vacuum （V） plasma-sprayed pure Ti prosthetic joint with HA coating （HA＋Ti＋V group）; vacuum plasma-sprayed pure Ti prosthetic joint with Ti-HA stepped coating （Ti＋HAG＋Ti＋V group）. The hip joints were functionally evaluated, and subjected to X-ray examination, biomechanics inspection, and histological examination. As a result, X-ray imaging revealed all prosthetic joints were in a good location and no dislocation of joint was found. Shear strength of interface was significantly higher in Ti＋HAG＋Ti＋V group than in HA＋Ti＋V group （P〈0.05） and HA＋Ti＋A group （P〈0.05） at 28th week. Histological examination showed the amount of newborn bone in Ti＋HAG＋Ti＋V group was more than in HA＋Ti＋V group and HA＋Ti＋A group after 28 weeks. It was suggested that vacuum plasma-sprayed pure Ti prosthetic joint with TI-HA stepped coating could improve the bonding capacity of bone-prosthesis, enhance the stability of prosthesis, and increase the fixion of prosthetic femoral components because of better bone growth. This new type of biological material in prosthetic femoral components holds promises for application in clinical practice.

基于碳捕集-电转气的矿区综合能源系统协同优化调度

“双碳”战略目标下,为促进风光消纳与能源电力低碳转型、提高矿区能源利用率,提出一种含伴生能源和碳捕集与电转气耦合的矿区综合能源系统低碳经济调度模型。首先,综合考虑瓦斯、乏风、涌水等矿区伴生能源利用,建立矿区综合能源系统基本模型,并以碳捕集和电转气设备为耦合单元,促进节能减排与可再生能源消纳。然后,引入奖惩阶梯式碳交易机制,以矿区综合能源系统运行成本最小为目标,建立矿区综合能源系统协同优化调度模型。最后,以中国云南某大型煤矿为例,通过设置不同场景进行仿真分析。结果表明,所提模型能够促进矿区综合能源系统低碳经济运行,提高风光消纳率。

考虑含HRD的光热电站和综合需求响应的综合能源系统低碳经济调度

在“双碳”的背景下,为进一步提升综合能源系统(Integrated Energy System, IES)的经济性和环境效益,文中提出一种在奖惩阶梯型碳交易机制下考虑含热回收装置(Heat Recycling Device, HRD)的光热电站和综合需求响应的IES系统低碳经济调度方法。首先,在源侧构建含热回收装置的光热电站与加装碳捕集的热电联产机组联合运行的IES架构,并分析电转气两阶段的运行原理,建立计及余热回收的电转气设备模型。其次,考虑到负荷侧电、热、气三种负荷的柔性特性,在负荷侧建立电热气综合需求响应模型。最后,引入奖惩阶梯型碳交易机制,进一步减小系统碳排放量,构建调度周期内以含购能成本、运维成本、碳交易成本等系统总运行成本最小为目标的综合能源系统低碳优化调度模型。通过算例分析结果表明,所提方法不仅能提高机组的运行潜力,而且有效降低了系统总运行成本与碳排放量。

基于深度强化学习的园区综合能源系统低碳经济调度

为降低园区综合能源系统的运行成本和碳排放量,同时应对系统不确定性带来的随机波动,提出一种考虑阶梯式碳交易的园区综合能源系统低碳经济调度模型,并采用深度强化学习方法求解。首先构建园区阶梯式碳交易模型,将碳交易成本考虑在内对园区综合能源系统低碳经济调度问题进行数学描述;其次将该调度问题表述为马尔可夫决策过程框架,定义系统的观测状态、调度动作和奖励函数;继而采用近端策略优化算法进行低碳经济调度决策。所提方法无需进行负荷预测或不确定性建模,能够对源和荷的随机波动做出实时响应。最后基于多场景多算法进行算例仿真,结果表明所提方法提高系统运行经济性的同时降低了系统碳排放量。

考虑条件风险价值的交直流系统两阶段分布鲁棒低碳经济优化调度

考虑到海上风电出力的随机性以及日益突出的生态环境问题,以含柔性直流输电技术(voltagesource converter high voltage direct current,VSC-HVDC)的交直流系统为研究对象,提出了考虑条件风险价值(conditional valueatrisk,CVaR)的两阶段分布鲁棒低碳经济优化模型,构建了基于Kullback-Leibler(KL)散度的概率分布模糊集,同时利用条件风险价值量化了极端场景下的尾部风险,使得模型能够同时考虑概率分布不确定性以及处于最坏概率分布中极端场景下的尾部损失;此外,将阶梯型碳交易机制并入所提分布鲁棒模型中,通过合理利用柔性资源和储能装置,增强系统运行的灵活性,在兼顾运行风险的前提下,降低碳排放量的目标。再者,为了提高计算效率,在列和约束生成算法(column-and-constraint generation method,C&CG)和Multi-cut Benders分解算法的基础上提出了双循环分解算法。最后,在基于改进的IEEE RTS 79测试系统中验证了所提模型及算法的有效性。

考虑阶梯式碳交易与电热需求响应的综合能源系统经济调度

在能源安全新战略背景下,推动可再生能源发展、降低碳排放将是未来发展趋势。为了消纳大规模风电的弃风功率以提升电网的调峰能力,首先考虑阶梯式碳交易机制,采用碳交易市场,利用碳交易价格达到控制碳排放的目的;其次基于分时电价形成用户用电舒适度与用热舒适度,构建电热负荷需求响应模型,在掌握电锅炉、储热装置和热需求可时移特性的基础上,通过风电供给价格弹性系数描述风电出力与电锅炉协议电价之间的变化;最后通过综合满意度指标评估负荷响应能力,构建了考虑需求响应和阶梯式碳交易机制的含蓄热式电锅炉综合能源系统优化调度模型,实现系统经济运行,并采用CPLEX求解器对所构建模型进行求解。结果表明所提方法能够有效促进风电消纳,减少碳排放量且有效降低系统运行成本。

考虑阶梯碳交易与绿证交易的综合能源系统优化调度

为减小综合能源系统的碳排放量以及提高可再生能源消纳能力,提出考虑阶梯碳交易机制与绿证交易机制的综合能源系统绿色调度模型。首先介绍了阶梯碳交易机制与绿证交易机制,并建立其数学计算模型,同时引入可再生能源电力消纳责任权重对绿证交易进行约束;其次以系统的运行维护成本、投资成本、碳交易成本以及绿证收益之和最大为目标分析两机制对系统的影响;最后分析不同碳交易机制参数与绿证参数对系统的影响。结果表明:综合能源系统中考虑碳交易机制与绿证交易机制具有较高的经济性,同时可以有效减小系统的碳排放量,提高了可再生能源的消纳量。

园区综合能源系统低碳经济优化调度模型研究

现有的园区综合能源系统调度方案,存在成本高、污染环境且能源利用率低等问题。因此,提出一种计及电转气和碳交易机制的园区综合能源系统低碳经济优化调度模型。首先,重点分析电转气过程甲烷化环节强放热特性,研究其对系统优化调度的影响;其次,构建含补偿系数的综合园区能源系统阶梯式碳交易机制,以约束园区碳排放;最后,建立以运行成本、弃能功率、碳排放量最小为目标的园区综合能源系统优化调度模型,并进行多目标优化计算。结果表明:所提优化模型的总成本、弃能功率和碳排放量分别下降了15.4%、98.3%和19.7%。因此,该文所提园区综合能源系统优化调度模型提高了对能源的利用效率和经济性,并有效降低了园区的碳排放。

考虑双层奖惩型碳交易机制的源网荷分布协同低碳经济调度

在“双碳”目标下,设计合理的碳交易机制使源网荷共同参与碳市场,对节能减排具有重要意义。在此背景下,提出了考虑双层奖惩型碳交易机制的源网荷分布协同低碳经济调度策略。首先,建立双层奖惩型碳交易机制下综合能源供应商-园区协同的低碳调度模型,综合能源供应商直接参与外部奖惩型阶梯碳交易市场,园区通过向综合能源供应商支付碳费用或获取碳收益间接参与碳市场,从而激发各主体积极参与节能减排。其次,建立奖惩型阶梯碳价格模型,并提出奖惩型阶梯碳价格机制下综合能源供应商-多园区的碳成本/收益分摊方法,保证了碳成本/收益分摊的有效性与合理性。再次,分别构建综合能源供应商与多园区低碳调度模型,并基于纳什协商刻画园区间的合作博弈,通过各园区间功率互济降低碳排放并提高社会效益。然后,提出了基于自适应调节机制的嵌套交替方向乘子法的双层分布式求解方法。最后,以IEEE 14节点配电网与12线路热管网组成的源网荷综合能源系统为例,验证了所提模型和方法的有效性。

基于生命周期理论的区域综合能源系统-配电网博弈优化调度

为解决区域综合能源系统与主动配电网因交互产生的利益冲突和自身碳排放问题,提出一种基于生命周期理论的区域综合能源系统-配电网博弈优化调度方法。首先,在能源系统耦合侧采用以热电联产机组为核心,使用耦合碳捕集与电转气设备构建动态碳循环,并利用需求侧资源进一步限制碳排放行为。然后,在阶梯碳交易制度下引入生命周期理论,分析各环节的碳排放,实现对多元能源活动的整个生命周期碳排放量计量。最后,构建以主动配电网为主体,区域综合能源系统为跟随者的博弈模型,并求解和筛选所提模型的纳什均衡解。仿真结果表明,博弈双方均能不断优化自身能源策略,最终实现低碳、经济运行。

计及需求侧管理与碳排放的综合能源系统光-储设备优化配置方法

合理调整综合能源系统(IES)的配置结构能够有效提升其低碳经济运行水平,基于此,提出了一种计及需求侧管理与碳排放的IES光-储设备优化配置方法。基于IES典型拓扑及供能设备的工作机理,建立其冷-热-电-气能流模型;根据不同柔性负荷特点,从不同维度构建用能体验的评价指标,并提出一种考虑用户综合满意度的需求侧能量管理策略;在此基础上,为进一步提升系统的低碳性能,设计了一种计及全寿命周期碳排放的奖惩阶梯型碳交易机制;在同时考虑所提需求侧管理与碳交易机制的前提下,以设备全寿命周期内创造的总收益最大为优化目标,构建了从运行到规划层面的源-网-荷-储多环节协同的光-储设备优化配置模型及运行方案;基于某真实IES开展算例研究,结果验证了所提方法在避免设备冗余配置、减碳与提高经济运行水平方面的有效性。

低插损窄带TCSAW滤波器的设计与研制

为了减小窄带滤波器的插入损耗,在梯形拓扑的基础上引入并联电容,提出了一种并联电容型梯形拓扑。利用并联电容大幅度改变反谐振点频率的特点,以牺牲较小插入损耗的代价来缩小带宽。通过谐振器设计与进化算法寻优,成功研制出一款基于SiO_(2)/Cu/127°YX-LiNbO3结构的低插损窄带温补型声表面波(TCSAW)滤波器。实验结果表明,滤波器的中心频率为1514 MHz,相对带宽为0.46%,带内插入损耗仅1.45 dB,过渡带20 MHz带外抑制滚降到24 dB,远带带外抑制大于30 dB,WiFi频段抑制高达48 dB,频率温度系数TCF为-20×10^(-6)/℃,器件尺寸为1.1 mm×0.9 mm。

利用建筑虚拟储能提升风电消纳能力的电热联合系统优化调度方法

利用建筑虚拟储能能提升电热联合系统的风电消纳能力,但若只考虑建筑结构储能而不考虑室内空气储能会导致虚拟储能利用不足。针对此问题,在奖惩阶梯碳交易背景下提出一种利用建筑虚拟储能提升风电消纳能力的电热联合系统优化调度方法。首先,以室内空气和建筑结构热平衡模型为基础建立精细化建筑虚拟储能模型;其次,在系统中引入奖惩阶梯碳交易机制及需求响应机制;再次,考虑电、热功率平衡以及室内温度等约束,以电热联合系统总成本最低为目标函数,并提出改进型平衡器优化算法对目标函数进行优化求解;最后,对不同场景下电热联合系统对风电的消纳、CO_(2)排放及经济性进行分析,结果表明:所提方法不仅提高了电热联合系统的风电消纳率,降低了CO_(2)的排放量,且提升了经济性。

计及改进生物质燃气和阶梯碳交易的综合能源系统低碳经济调度

为了推动生物质能开发利用并提高综合能源系统运行能效,提出一种含改进生物质燃气BNG(biomass natural gas)和阶梯碳交易的综合能源低碳经济调度模型。首先,构建考虑二阶变压吸附的生物质燃气模型;其次,将生物质燃气耦合电转气和碳捕集系统,从而实现二氧化碳的利用与封存。然后,完善生物质燃气参与后的阶梯碳交易模型,以综合能源系统经济运行成本最小构建目标函数进行优化求解。最后,通过设置不同场景进行分析,验证所提模型能够有效提高系统的经济性以及低碳性。

Ladder型三能级介质中传播的少周期激光脉冲的空间分布

利用由时域有限差分法和预估校正法求得全波Maxwell-Bloch方程的数值解,研究少周期超短激光脉冲在Ladder型三能级原子介质中传播时脉冲及介质粒子布居的空间分布.结果表明,脉冲及介质粒子布居的空间分布规律随脉冲面积的改变而发生明显的变化.当脉冲面积较小时,脉冲形状不规则,振荡次数较多;当脉冲面积较大时,脉冲形状变得较为规则,振荡次数明显减少.随着脉冲面积的增大,脉冲振幅和传播速度逐渐增大,各能级粒子布居振荡次数增多,不同时刻的脉冲和粒子布居空间分布的变化明显减小.粒子布居的空间分布与脉冲的空间分布密切相关.