MULTI-PEAK MATCH INTENSITY RATIO METHOD OF QUANTI-TATIVE X-RAY DIFFRACTION PHASE ANALYSIS

A new method for quantitative phase analysis is proposed by using X-ray diffraction multi-peak match intensity ratio. This method can obtain the multi-peak match intensity ratio among each phase in the mixture sample by using all diffraction peak data in the mixture sample X-ray diffraction spectrum and combining the relative intensity distribution data of each phase standard peak in JCPDS card to carry on the least square method regression analysis. It is benefit to improve the precision of quantitative phase analysis that the given single line ratio which is usually adopted is taken the place of the multi-peak match intensity ratio and is used in X-ray diffraction quantitative phase analysis of the mixture sample. By analyzing four-group mixture sample, adopting multi-peak match intensity ratio and X-ray diffraction quantitative phase analysis principle of combining the adiabatic and matrix flushing method, it is tested that the experimental results are identical with theory.

A PHASE SCRAMBLING SCHEME FOR SUPPRESSION OF PEAK TO AVERAGE POWER RATIO FOR OFDM

The complex-valued modulating vectors for the subcarriers consist of two kinds of components: One is the information-bearing components superposed with pseudo-randomized phases and the other is the suppression components with specified scrambling phases. The pseudo randomized phases are generated according to the predefined polynomial and mapping function whereas the scrambling phases are from a gradient algorithm. The simulation results verify the rationality and validity of the phase scrambling.

浅析反相高效液相色谱中样品溶剂对中药成分色谱保留行为的影响

目的探究反相高效液相色谱(RP-HPLC)中样品溶剂对中药成分色谱保留行为的影响。方法选取2020版《中国药典》一部收载的5种中药,参照各药材含量测定项下要求进行HPLC法测定,初步研究龙胆苦苷-龙胆、紫丁香苷-刺五加、松脂醇二葡萄糖苷-杜仲、秦皮甲素-秦皮、腺苷-冬虫夏草受样品溶剂影响产生的色谱峰异常行为,深入探讨溶剂效应的机理,并提出解决方案。结果5种中药化学成分的色谱异常行为表现为保留时间漂移、色谱峰展宽、前延及裂分,产生上述异常现象的根本原因是溶解样品的溶剂和流动相存在某种不匹配,导致样品在溶剂与流动相中所处状态出现差异(溶剂效应)。消除溶剂效应的首选方法是用流动相或相近的溶剂溶解样品,此外,减小进样量和使用溶剂效应消除器可作为辅助手段。结论溶剂效应容易引起色谱峰异常,影响对化学成分定性和定量的准确性,应该在日常中药分析工作中予以重视。

宽输入双有源桥变换器移相变频控制策略研究

重点分析三重移相控制下宽输入工况对双有源桥DC-DC变换器特性的影响,分别推导宽范围输入电压情况下软开关范围、电流峰值和电流有效值随开关频率变化的理论表达式。在此基础上,提出一种移相变频混合控制策略,通过调节开关频率扩大双有源桥DC-DC变换器的软开关范围,并降低电流峰值和电流有效值,提高变换器的整体效率。最后,搭建一台基于SiC器件的1 kW双有源桥DC-DC变换器样机验证所提控制策略的有效性。

一种无功补偿用磁保持继电器的试验设备研究

设计了一种适用于无功补偿用磁保持继电器的试验设备。该设备具备接通设定和分断设定等功能,即可控制触点的接通相位角及触点是否过零分断。试验过程中,软件界面可显示和保存触点接通瞬间电压波形、峰值电流和磁保持继电器的动作时间等记录。

具备故障重构能力的双极直流接口变换器最优运行区域

中低压直流配电系统中,现有的双极直流接口变换器通常无法在进入单极运行模式下实现故障阻断与重构功能。基于一种互联分布式电源与双极直流系统的故障重构型直流接口变换器拓扑,分析单双极性运行模式的工作性能。在正常的双极运行模式下,变换器通过最小峰值电流控制策略,实现开关器件电流应力有效降低。在短路故障导致的单极运行模式下,变换器通过故障重构策略与恒功率传输控制策略,消除短路故障对正常端口的不利影响,维持关键负荷的连续供电。同时给出变换器在单双极模式的优化控制策略下的软开关运行区域,从而精确刻画出变换器的最优运行区域。实验结果证明理论分析的正确性,研究工作有助于指导中低压直流配电系统的工程实践。

基于AKNN异常检验与ADPC聚类的低压台区拓扑识别方法

低压台区拓扑信息的准确记录是进行台区线损分析、三相不平衡治理等工作的基础。针对目前拓扑档案排查成本高且效率低的问题,提出一种基于自适应k近邻(adaptive k nearest neighbor,AKNN)异常检验和自适应密度峰值(adaptive density peaks clustering,ADPC)聚类的低压台区拓扑识别方法。该方法利用动态时间弯曲(dynamic time warping,DTW)距离度量低压台区用户间电压序列的相似性,通过AKNN异常检验算法检验并校正异常的用户与变压器之间的关系(简称“户变关系”),在得到正确户变关系的基础上,采用ADPC聚类算法对台区内用户进行相位识别;最后,通过实际台区算例分析验证了该方法不需要人为设置参数,能有效实现低压台区的拓扑识别,具有较高的适用性与准确性。

Phase Equilibria of Hornblende-Bearing Eclogite in the Western Dabie Mountain,Central China

The high-pressure （HP） eclogite in the western Dabie Mountain encloses numerous hornblendes, mostly barroisite. Opinions on the peak metamorphic P-T condition, PT path and mineral paragenesis of it are still in dispute. Generally, HP eclogite involves garnet, omphacite, hornblendes and quartz, with or without glaucophane, zoisite and phengite. The garnet has compositional zoning with XMg increase, XCa and XMn decrease from core to rim, which indicates a progressive metamorphism. The phase equilibria of the HP eclogite modeled by the P-T pseudosection method developed recently showed the following： （1） the growth zonation of garnet records a progressive metamorphic PT path from pre-peak condition of 1.9-2.1 GPa at 508~C-514~C to a peak one of 2.3-2.5 GPa at 528~C-531~C for the HP eclogite; （2） the peak mineral assemblage is garnet＋omphacite＋glaucophane＋quartz_＋phengite, likely paragenetic with lawsonite; （3） the extensive hornblendes derive mainly from glaucophane, partial omphacite and even a little garnet due to the decompression with some heating during the post-peak stage, mostly representing the conditions of about 1.4-1.6 GPa and 580~C-640~C, and their growth is favored by the dehydration of lawsonite into zoisite or epidote, but most of the garnet, omphacite or phengite in the HP eclogite still preserve their compositions at peak condition, and they are not obviously equilibrious with the hornblendes.

相变储能技术在煤矿供暖系统的研究与应用

传统供暖方式包括燃煤、燃油、燃气炉加热,投入高、热效率低,碳排放量高,对自然环境污染严重。为了落实中国双碳政策,采用相变储能和谷峰错时用电储能的原理,研究了相变材料的储热密度、体积变化、热导率和热传导系数的影响因素,选用了固—液相变潜热大的无机水合共晶盐相变材料,采用HDPE(高密度聚乙烯材料)和PP(聚丙烯材料)将相变材料封装成球体,提高了热能效率。根据研究结果,按照山西正升煤业集团的供暖要求,结合矿井实际供暖区域分布,设计了供暖方案,计算了供暖负荷,选定了供暖设备,配置了自动化控制系统,解决了相变储能技术在严寒地区、煤矿生产条件恶劣的条件下,提供绿色清洁能源供暖的难题,为相变储能技术在严寒、高寒、条件受限等地区的供暖提供成功案例和借鉴,具有推广意义。相变储能技术通过储存多余的能量,并在需要时释放,减少因能量浪费产生的碳排放,利用谷峰错时将能源单价相对较低的电能储存,可以平抑电网负荷,减轻电力系统的负担,进一步降低能源消耗和碳排放,响应了国家双碳政策,具有良好的经济效益和社会效益。

Some nonlinear parameters of PP intervals of pulse main peaks

The PP intervals of pulse main peaks from healthy and unhealthy people(arrhythmia) have different nonlinear char-acteristics. In this paper,the extraction of PP intervals of pulse main peaks is achieved by picking up P peaks of pulse wave with wavelet transform. Furthermore,several nonlinear parameters(correlative dimensions,maximum Lyapunov exponents,com-plexity and approximate entropy) of the PP intervals of pulse main peaks extracted from normal and unhealthy pulse signals are calculated,with the results showing that these nonlinear parameters calculated from the main wave interval signals are helpful for analyzing human's health state and diagnosing heart diseases.

Conditions and Phase Shift of Fluid Resonance in Narrow Gaps of Bottom Mounted Caissons

This paper studies the viscid and inviscid fluid resonance in gaps of bottom mounted caissons onthe basis of the plane wave hypothesis and full wave model, The theoretical analysis and the numerical results demonstrate that the condition for the appearance of fluid resonance in narrow gaps is kh=（2n＋1）π （n=0, 1, 2, 3 ）, rather than kh=nn （n=0, 1, 2, 3, ...）; the transmission peaks in viscid fluid are related to the resonance peaks in the gaps. k and h stand for the wave number and the gap length. The combination of the plane wave hypothesis or the full wave model with the local viscosity model can accurately determine the heights and the locations of the resonance peaks. The upper bound for the appearance of fluid resonance in gaps is 2b/L〈l （2b, grating constant; L, wave length） and the lower bound is h/b〈~ l. The main reason for the phase shift of the resonance peaks is the inductive factors. The number of resonance peaks in the spectrum curve is dependent on the ratio of the gap length to the grating constant. The heights and the positions of the resonance peaks predicted by the present models agree well with the experimental data.

Low-complexity PTS scheme based on phase factor sequences optimization

In this paper, a new partial transmit sequence（PTS）scheme with low computational complexity is proposed for the problems of high computational complexity in the conventional PTS method. By analyzing the relationship of candidate sequences in the PTS method under the interleaved partition method, it has been discovered that some candidate sequences generated by phase factor sequences have the same peak average power ratio（PAPR）. Hence, phase factor sequences can be optimized to reduce their searching times. Then, the computational process of generating candidate sequences can be simplified by improving the utilization of data and minimizing the calculations of complex multiplication. The performance analysis shows that, compared with the conventional PTS scheme, the proposed approach significantly decreases the computational complexity and has no loss of PAPR performance.

基于质心寻峰的调频连续波激光干涉位移传感器

调频连续波激光干涉技术在精密测量领域中应用广泛,针对其高精度位移解调问题,本文将质心法应用于其拍频信号的解调中,提出了一种基于质心寻峰法的相位解调算法并进行实验与分析。提出的算法在对截取的拍频信号进行平滑滤波与分峰截幅等处理基础上,通过质心坐标公式得到拍频信号的质心,质心横坐标即为峰值位置,最后通过相位鉴别算法解调出位移。在仿真中设置信噪比(SNR)为15 dB,算法的相位误差为0.016 rad,位移误差为2.04 nm。搭建调频连续波激光干涉位移测量系统进行实验验证,实验结果表明:当固定距离为44 mm时,位移随机误差标准差为2.18 nm。与常规的过零点检测法进行对比分析,结果表明该算法的测量误差降低了49%,分辨率获得了提高,具有广泛的应用前景。

集群无人机载雷达阵列波束合成

集群无人机载雷达阵列具有较高的机动性与灵活性,相关研究受到广泛关注。波束合成是集群无人机载雷达阵列的重要功能之一,该功能的实现面临较多挑战。本文首先构建了波束合成信号模型并分析了位置不确定性、时间同步不确定性、天线指向不确定性以及通道不确定性的影响;其次,推导了波束合成信号模型的克拉美罗界和峰值旁瓣电平并提出了集群无人机构型优化方法;最后,提出了一种幅相误差处理策略,主要包括基于高精度测距的定位和时间同步系统设计以及幅相误差快速补偿两部分。仿真结果和工程实验证实了集群无人机载雷达阵列波束合成的可行性。

Novel non-coherent integration method using binary phase-coded radar signal

The m series with 511 bits is taken as an example being applied in non-coherent integra- tion algorithm. A method to choose the bi-phase code is presented, which is 15 kinds of codes are picked out of 511 kinds of m series to do non-coherent integration. It is indicated that the power in- creasing times of larger target sidelobe is less than the power increasing times of smaller target main- lobe because of the larger target＇ s pseudo-randomness. Smaller target is integrated from larger tar- get sidelobe, which strengthens the detection capability of radar for smaller targets. According to the sidelobes distributing characteristic, a method is presented in this paper to remove the estimated sidelobes mean value for signal detection after non-coherent integration. Simulation results present that the SNR of small target can be improved approximately 6. 5 dB by the proposed method.

不耦合系数对CO_(2)相变致裂影响数值模拟及研究

为了提高液态CO_(2)相变致裂的增透效果,探究孔径尺寸对致裂效果的影响,采用LS-DYNA软件对“不耦合装药”结构下CO_(2)致裂效果进行数值模拟,分别得到了不同径向不耦合系数下的损伤分布云图、孔壁压力时程曲线、峰值速度分布图,采用“Logistic”函数对损伤分布进行描述。研究表明,随着不耦合系数的增大,压碎区范围先快速减小后缓慢减小,裂隙区呈先增大后减小的变化趋势,在K=1.46时破坏区范围最大,此时为最优不耦合系数;当K=1.60时,压碎区与裂隙区的过渡特征变得不再明显,破坏区主要由均匀的裂隙区构成;不耦合致裂结构能改变爆生气体应力波加载方式,降低应力波峰值、延长应力波作用时间,从而能有效降低CO_(2)相变致裂的振动效应,径向不耦合系数K=1.60相较K=1.07,振动强度降低2.48倍。现场试验表明:采用K=1.46致裂结构产生较小的压碎区,裂隙扩展区较K=1.07更大,裂纹发育更长,瓦斯体积分数与瓦斯纯流量较致裂前增加了4.28倍、4.89倍,相较K=1.07瓦斯抽采效果更佳。该研究结果可为CO_(2)相变致裂效果提供理论支撑。

FBMC/OQAM系统中改进的峰均比抑制方法

针对偏移正交幅度调制的滤波器组多载波(FBMC-OQAM)系统中峰值平均功率比(PAPR)过高会引起失真且对信道估计性能造成影响的缺点,提出了一种基于相位旋转的干扰消除法(ICM-P)。该方法产生不同的相位序列,与传输数据相乘得到多组数据序列,分别计算其PAPR,并选择PAPR最低的一组进行传输。仿真验证与分析表明:所提方法能有效降低系统过高的峰值平均功率比,误码率不高,且信道估计性能较原ICM方法没有明显下降。

基于多粒度聚类和多元特征统计的低压配电网拓扑识别与监测

针对低压配电网中用户的户变关系及相位信息常存在错误且变动较为频繁的现象,提出了一种基于多粒度聚类和多元特征统计的低压配电网拓扑识别与监测方法,包含拓扑聚类识别和拓扑统计监测2个阶段。在拓扑聚类识别阶段,基于用户电压波动曲线的α-峭度和α-偏度提取数据粗粒度空间特征,采用密度峰值聚类算法识别所有用户的户变关系;在数据细粒度特征空间,通过考虑延迟效应的动态时间弯曲距离算法优化密度计算过程,实现相位关系的精确聚类。在拓扑统计监测阶段,基于多粒度聚类结果,采用邻域保持嵌入算法建立多元统计监测模型,实现新增用户或拓扑有变化的个别用户的拓扑快速识别。实际算例的分析结果验证了所提方法的有效性。

一种应用于双相峰值电流模Buck的轻载模式

设计了一种双相位峰值电流模控制、具有大负载能力的降压稳压芯片。通过双相位的工作,保证了芯片在重载下具有较高的效率。同时,为了防止在轻载下两个相位的工作引入额外的开关损耗,提出了一种轻载模式。通过利用电流模控制模式中电压环路内误差放大器产生的控制电压来检测实际负载的大小,实现相位的切换以及在更低负载下的断续导通降频工作模式。基于0.35μm BCD工艺进行仿真设计。仿真结果表明,在输入电压12 V,输出电压1 V,开关频率500 kHz,最大负载20 A下,与传统单通道峰值电流模比较,重载20 A下的效率可以提升3个百分点,轻载0.5 A下的效率可以提升10个百分点。

基于动态字典的峰谷分离去强反射屏蔽方法

地震数据中常存在强反射背景,例如灰质成分或因泥岩脱水等作用形成的高速层反射、煤系地层反射等,这些强反射屏蔽了储层的有效反射信息,使目的层反射较弱,影响了储层预测效果。为消除地震反射强能量对目的层反射特征的影响,通常采用以雷克子波作为基本原子的匹配追踪方法,由于雷克子波存在旁瓣,在去强反射同相轴时会对旁轴产生干扰。为此,提出一种基于Gauss子波的匹配追踪强反射屏蔽分离方法。Gauss子波没有旁瓣,而且具有控制参数少、能量集中的优点,在去强反射的同时不会对旁轴产生影响。该方法首先将Gauss子波作为基本原子建立动态子波库,其次利用层位信息获得强反射同相轴波峰波谷位置,然后依次对强反射同相轴的波峰波谷分别进行分解重构。通过设置残差阈值控制迭代次数,且每次重构时去除与地震强反射分量最大相关的分量,以达到消减强反射屏蔽的目的。设计了一维和二维强反射屏蔽模型验证了方法的适用性,理论模型和实际数据应用结果表明该方法能有效消减强反射屏蔽,突出强反射周围的弱反射信息,且分解后残余能量较少,不会对旁轴产生影响。