基于负荷聚合商模式的电网协同优化调度

在新能源在电网的渗透率增高以及柔性负荷作为调节手段出现的背景下,选取合适的调度模式,使得海量分布式的负荷资源参与电网调控,能够帮助实现削峰填谷、平滑负荷曲线等目标。基于负荷聚合商模式的协同控制结构,对包括电动汽车、空调负荷与储能设备的负荷资源进行聚合,建立了日前经济调度模型;在负荷聚合商的集群内部控制中,考虑设备的调度潜能,提出一种基于裕度指标的状态队列优先算法,实现部分负荷优先响应。最后,仿真算例得出了负荷聚合商参与电力系统的日前协同调度运行计划,验证了优化方法以及调控策略的可行性。     

具有非匹配扰动的非线性变参数系统模型参考跟踪控制

本文研究了一类含有非匹配扰动的非线性变参数系统的跟踪控制问题.首先,设计非线性扰动观测器用于估计系统所受到的未知扰动.其次,在前馈–反馈跟踪控制器中引入扰动补偿控制项,提出一种基于扰动观测器的跟踪控制策略.利用依赖于状态和时变参数的线性矩阵不等式,导出保证闭环系统输入–状态稳定的充分条件,进而运用平方和凸优化技术解析地构造出扰动观测器和跟踪控制器.通过理论证明,所设计的控制策略能够实现非线性变参数系统输出对参考模型输出的跟踪,消除输出通道中非匹配扰动的影响.最后,由数值仿真例子验证了所提方法的有效性.     

面向逆变器并联的虚拟振荡器控制技术综述

虚拟振荡器控制作为继下垂控制和虚拟同步机控制之后提出的新型多逆变器无互联线并联技术,因其独特的自同步机制和快速的动态响应性能等特点而成为当前的研究热点。从控制结构、多机同步运行机制和动力学特性方面论述了虚拟振荡器的控制原理;从功率控制策略、小信号稳定性、新型虚拟振荡器方案3个方面对虚拟振荡器控制技术的研究现状进行了全面综述;分析并总结了虚拟振荡器控制与下垂控制、虚拟同步机控制的对比研究。结合目前虚拟振荡器控制面临的若干关键问题,对未来研究方向和可能的相关解决思路进行了探讨。     

聚类分割的交互式遥感热红外图像模糊增强北大核心CSCD

交互式遥感热红外图像在边缘区域的像素呈现较强交互干扰,缺少必要区分过程,导致增强后的交互式遥感热红外图像视觉效果差、抗噪性能差、增强效率低。提出基于聚类分割的交互式遥感热红外图像模糊增强方法,采用模糊C均值聚类算法,对交互式遥感热红外图像聚类分割处理,对边缘区域特殊及弱小交互目标分割,进一步区分交互区域的干扰,缩短后期增强所用的时间。采用中值滤波方法去除交互式遥感热红外图像中存在的噪声,结合Sobel算子和二阶微分算子的拉普拉斯算子对去噪后的交互式遥感热红外图像进行锐化处理,通过图像去噪和图像锐化实现交互式遥感热红外图像的模糊增强。仿真实验可知,所提方法进行交互式遥感热红外图像模糊增强所获取的图像清晰度较高、抗噪性能较佳、增强效率较高。     

光子晶体制备及其应用研究进展

综述了光子晶体的特性以及制备方法,分别介绍了光子晶体在光子晶体光纤、光子晶体滤波器、低阈值激光器、光子晶体结构色等领域的应用研究现状,展示了光子晶体器件的巨大发展潜力,并指出了光子晶体今后的研究方向。同时笔者认为将3D打印技术与光子晶体器件的制备相结合,对早日实现光子晶体器件的实际应用意义重大。     

旋转摩擦挤压法制备CNTs/Mg复合材料的组织和力学性能

通过显微硬度和抗拉强度试验、X射线衍射仪、扫描电镜和金相显微镜观察,研究经旋转摩擦挤压法制备的CNTs/Mg复合材料的组织及性能。结果表明:CNTs/Mg复合材料的组织为细小等轴晶,且随着CNTs含量的增加,复合材料晶粒尺寸逐渐细化,当CNTs含量为5%时,晶粒尺寸最小,由63μm减小至3.79μm,为AZ91基材晶粒尺寸的6.01%。经过旋转摩擦挤压加工后基材内第二相β-Al12Mg17相的量减少,CNTs的加入使复合材料中出现了Al4C3相,且第二相β-Al12Mg17相网状结构消失。加工后的镁合金抗拉强度提高,最大值为330.9 MPa,较原基材提高了90.6%,当CNTs含量小于2%时,复合材料强度高于原基材。复合材料硬度随着CNTs含量的增加呈先增加后降低的趋势,当CNTs含量为2%时,硬度最高,达101.3HV,比AZ91基材提高了40.3%。     

铝合金厚板搅拌摩擦焊焊缝局部金属的塑性流动特征

以0.02mm厚铜箔为标示材料,采用带三角平面圆锥形搅拌针对20mm厚7075-T6铝板进行焊接。通过测试沿焊缝厚度方向上温度场分布及观察标示材料分布状态,分析焊缝局部金属塑性流动行为特征。结果表明,沿焊缝厚度方向上自上而下的金属温度逐渐降低;焊缝上、下表面温度差约为90℃;同一厚度上相对称的两点,位于前进边金属的温度高于返回边约15℃。位于焊核区上部的铜箔呈细小颗粒状均匀分布;下部铜箔则呈层片状分布,且向前进边偏移。焊核区由多个呈纹路状、有序排列的洋葱环结构相互层叠而成,这与焊缝塑化金属沿轴向迁移方式发生变化有关。     

Linkage map of Escherichia coli K-12, edition 10: the physical map

A physical map, EcoMap10, of the now completely sequenced Escherichia coli chromosome is presented. Calculated genomic positions for the eight restriction enzymes BamHI, HindIII, EcoRI, EcoRV, BglI, KpnI, PstI, and PvuII are depicted. Both sequenced and unsequenced Kohara/Isono miniset clones are aligned to this calculated restriction map. DNA sequence searches identify the precise locations of insertion sequence elements and repetitive extragenic palindrome clusters. EcoGene10, a revised set of genes and functionally uncharacterized open reading frames (ORFs), is also depicted on EcoMap10. The complete set of unnamed ORFs in EcoGene10 are assigned provisional names beginning with the letter "y" by using a systematic nomenclature.     

Serum from diabetic BB/W rats enhances calcium currents in primary sensory neurons

We examined the hypothesis that exposure of nondiabetic rat dorsal root ganglion (DRG) neurons to sera from diabetic BB/W rats would produce an increase in calcium currents associated with impaired regulation of the inhibitory G protein-calcium channel complex. Acutely dissociated rat DRGs were incubated for 18-24 h in medium supplemented with sera (10% vol/vol) from either diabetic rats with neuropathy or age-matched, nondiabetic controls. Exposure of DRG neurons to sera from diabetic BB/W rats resulted in a surface membrane immunofluorescence pattern when treated with an anti-rat light-chain antibody that was not observed in neurons exposed to control sera. Calcium current density (IDCa) was assessed with the use of the whole cell variation of the patch-clamp technique. IDCa in neurons exposed to diabetic sera was significantly increased compared with neurons exposed to control sera. Guanine nucleotide-binding (G) protein regulation of calcium channel function was examined with the use of a two-pulse "facilitation" or IDCa enhancement protocol in the presence of activators [guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S)] or antagonists [guanosine 5'-O-(2-thiodiphosphate) (GDP beta S) and pertussis toxin (PTX)] of G protein function. Facilitation was significantly decreased in neurons exposed to diabetic sera. Intracellular diffusion of neurons with GDP beta s blocked facilitation, whereas dialysis with GTP gamma s increased facilitation to a similar magnitude in neurons exposed to either diabetic or control sera. Treatment with PTX resulted in a significant increase in IDCa and approximately 50% decrease in facilitation in neurons treated with control sera but no significant changes in neurons exposed to diabetic sera. We conclude that serum from diabetic BB/W rats with neuropathy contains an autoimmune immunoglobulin that impairs regulation of the inhibitory G protein-calcium channel complex, resulting in enhanced calcium influx. Regulation of the inhibitory G protein-calcium channel complex involves PTX-sensitive and -insensitive G proteins.     

Ecstasy--cool dope with long-lasting effects?

The amphetamine derivative MDMA (3,4-methylenedioxymethamphetamine) was first synthesised in 1914 as an appetite suppressant, but was never used as such. MDMA is commonly known as "ecstasy" and has become a popular recreational drug of abuse at dance-clubs and rave parties, where it is combined with all-night dancing, crowded conditions, poor hydration and loud sound. This combination is probably the main reason why we have seen an upsurge in toxicity problems at rave parties, since all these factors are thought to promote or increase the toxicity of MDMA. The desired effects of MDMA are euphoria, increased energy and enhanced communication with others. Adverse effects are hyperthermia, rhabdomyolysis, acute renal failure, hepatotoxicity, depression and psychosis.