基于流量测点的热网变动阻力系数优化辨识

随着供热计量系统的普及，系统可以根据负荷的变化进行调整，管网的阻力系数随即发生变化。对变动阻力系数进行优化辨识是了解供热管网实时运行状况的有效手段。提出一种基于流量监测数据的供热管网变动阻力系数优化辨识方法，并利用遗传算法进行求解。对洛阳市某小区供暖季管网实际运行数据进行验证，辨识结果的相对误差在5%以内。结果表明：该方法可以在只有流量观测数据时得到精度较高的供热管网变动阻力系数，为供热系统的运行调节提供指导。     

基于电化学老化衰退模型的锂离子动力电池外特性

当前锂离子动力电池电化学模型存在模型复杂、建模难度大、计算效率低、老化评估效果差的问题,本文提出一种考虑电池衰退老化的机理模型(ADME).本文首先通过有限差分法对伪二维(P2D)电化学模型进行离散降阶处理,得到简化伪二维(SP2D)模型.在SP2D模型的基础上,基于阴阳两极发生的副反应导致的衰退老化现象,提出一种考虑电池衰退老化的机理模型.其次,使用多变量偏差补偿最小二乘法实现模型参数辨识.最后通过动力电池衰退老化性能循环实验,对比分析了恒流、脉冲工况下SP2D模型和ADME模型的终端电压输出.结果表明:ADME模型较为简单、计算效率和估算精度高,可以有效评估电池容量老化衰退,得到理想的锂离子动力电池外特性曲线.     

The chemical profile of active fraction of Kalimeris indica and its quantitative analysis

Kalimeris indica (L) Sch-Bip is a medicinal plant used by the Miao ethnic group in the Guizhou province of China. It is widely used as a fresh vegetable to treat colds, diarrhea and gastric ulcers. However, few studies have been conducted on the mechanism of its effect on colds, and its quality control. The anticomplement and antitussive activities of different polar extracts of K. indica were evaluated. Fifty-nine compounds, mainly including phenols and flavonoids, were identified in K. indica extract by ultra-high-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry. A method was established through ultra-high-performance liquid chromatography with a photodiode array to simultaneously determine the anticomplement and antitussive activity of five compounds in K. indica combining chemical identification with chemometrics for discrimination and quality assessment. Also, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid exhibited significantly higher anticomplementary activity than the other three compounds. The quantitative data were further analyzed by principal component analysis and orthogonal partial least-squares discriminant analysis. Heatmap visualization was conducted to clarify the distribution of the major compounds in different geographical origins. Screening pharmacological activities by a combination of chemometrics and chemical identification might be an effective method for the quality control of K. indica.     

不同结构绝对光栅尺的误码机制研究

针对光栅尺具有断电位置复位、无累计误差、高精度优点, 在光学隔振平台上分别建立开放式和封闭式绝对光栅尺实验系统, 绝对光栅尺采用图像识别原理, 以气浮直线电机ArotechABL1500为参考对象, 使用激光干涉仪RENISHAW XL-80校核精度, 研究不同结构绝对光栅尺的误码特点及原因。通过对比实验及研究分析, 表明封闭式绝对尺相对于开放式绝对尺的误码率要高, 开放式绝对式光栅尺的误码率为3%, 封闭式绝对式光栅尺的误码率为8%。     

Studies on metabolism of total glucosides of paeony from Paeoniae Radix Alba in rats by UPLC‐Q‐TOF‐MS/MS

Total glucosides of paeony are the active constituents of Paeoniae Radix Alba. In this study, a novel strategy was proposed to find more metabolites and the differences between paeoniflorin, albiflorin and total glucosides of paeony (TGP). This strategy was characterized as follows: firstly, the animals were divided into three groups (paeoniflorin, albiflorin and TGP) to identify the source of TGP metabolites from paeoniflorin or albiflorin; secondly, a generic information‐dependent acquisition scan for the low‐level metabolites was triggered by the multiple mass defect filter and dynamic background subtraction; thirdly, the metabolites were identified with a combination of data‐processing methods including mass defect filtering, neutral loss filtering and product ion filtering; finally, a comparative study was used in the metabolism of paeoniflorin, albiflorin and TGP. Based on the strategy, 18 metabolites of TGP, 10 metabolites of paeoniflorin and 13 metabolites of albiflorin were identified respectively. The results indicated that the hydrolysis, conjugation reaction and oxidization were the major metabolic pathways, and the metabolic sites were the glycosidic linkage, the ester bond and the benzene ring. This study is first to explore the metabolism of TGP, and these findings enhance our understanding of the metabolism and the interactions of paeoniflrin and albiflorin in TGP. Copyright © 2015 John Wiley & Sons, Ltd.     

基于超限学习机算法的空间目标材质多色测光识别研究

随着各国航天活动的增多，空间目标的数量和种类不断增加，对空间目标进行编目识别是各国空间目标监视领域的重要研究内容。对空间目标进行识别，主要是为了获得其表面材质、姿态、形状、关键载荷等信息，而表面材质信息的获取是开展目标光学特性及状态认知研究的基础。搭建空间目标表面材质多色测光测量系统，整套系统部署在光学暗室内，以减少杂散光对测量结果的影响。光源采用太阳模拟器，光谱等级A级；探测器采用美国ASD公司生产的FieldSpec4地物光谱仪，波长范围350～2 500 nm，光谱分辨率1 nm，光纤置于电控转台上，能对待测样片实现不同观测几何下的测量。利用Johnson-Cousins UBVRI五色分光系统对8种常用表面材质（砷化镓、氧化铝、氧化聚酰亚胺薄膜、黑漆、环氧漆、镀铝聚酰亚胺薄膜、钛青蓝漆、白漆）在不同观测几何条件下的10种色指数数据进行实验测量，每种色指数分别测得30组实验数据。采用传统的1-sigma不确定框方法（即对于给定材质的若干组实验数据，计算其每种色指数的平均值和标准差，以平均值为中心，以标准差的两倍为边长画出色指数不确定框），在最理想的识别情况下，通过R-I和B-R色指数不确定框能对砷化镓、氧化铝、氧化聚酰亚胺薄膜、钛青蓝漆四种材质进行识别；利用B-V和B-R色指数不确定框可以将环氧漆、白漆识别出来，剩余两种材质黑漆和镀铝聚酰亚胺薄膜无法通过以上色指数进行识别。但是1-sigma不确定框方法存在两个主要问题：一是需要知道待测材质对特定波段敏感的先验信息，来确定所用的色指数类型；二是识别率容易受测试样本数量的影响，可靠性差。超限学习机算法是一种利用随机化隐层节点和和最小二乘求解方式进行训练的机器学习算法，具备学习效率快，泛化性能好，不容易陷入局部最优解等优势，被广泛应用于对数据的分类和回归分析中。因此引入超限学习机算法，将色指数数据按照2∶1的比例随机分为训练样本和测试样本，共进行三次随机试验。在训练样本中，对每种材质按照1∶8的顺序进行编号，即编号1∶8的测试样本分别有20个，分别包含10种色指数数据；在测试样本中同样对其按照已知归属材质对应编号。采用决定系数和计算时间作为判断ELM算法准确性和实时性的判断指标。结果表明：无论是对单一材质进行识别，还是对所有测试材质样本，训练样本决定系数在0.98以上，测试样本决定系数在0.96以上，每次试验中最多有3组色指数数据无法识别；所需总时间最长在0.07 s内完成，甚至可以达到0.002 s，识别效率和可靠性远高于传统的1-sigma不确定框法，表明ELM算法能对空间目标常用材质进行准确快速识别。相关研究可为空间非合作目标的外形、姿态等状态信息反演提供技术支持。     

An identification method to estimate surface shortwave fluxes on temperature and thickness observations of sea ice in CHINARE 2006

In this paper, a parameter identification method to determine surface shortwave fluxes using temperature and thickness measurements of sea ice in CHINARE 2006 is presented. Adopting a new standard for the calculation of the thermodynamic properties of seawater named TEOS‐10, the surface shortwave fluxes are calculated by the temperature and thickness observations that were measured at Nella Fjord around Zhongshan Station, Antarctica. New simulations for temperature profiles in a different measurement period are performed by three parameterization schemes including the present method, Zillman and Shine. All numerical results are compared with in situ measurements. Results show that better simulations of the surface shortwave radiations and temperature distributions are possible with the identification method than Zillman and Shine. Therefore this method is valid, and the obtained shortwave radiation function can be applied in sea ice modeling. Copyright © 2015 John Wiley & Sons, Ltd.     

Simultaneous isolation and label‐free identification of bacteria using contactless dielectrophoresis and Raman spectroscopy

The traditional bacterial identification method of growing colonies on agar plates can take several days to weeks to complete depending on the growth rate of the bacteria. Successfully decreasing this analysis time requires cell isolation followed by identification. One way to decrease analysis time is by combining dielectrophoresis (DEP), a common technique used for cell sorting and isolation, and Raman spectroscopy for cell identification. DEP‐Raman devices have been used for bacterial analysis, however, these devices have a number of drawbacks including sample heating, cell‐to‐electrode proximity that limits throughput and separation efficiency, electrode fouling, or inability to address sample debris. Presented here is a contactless DEP‐Raman device to simultaneously isolate and identify particles from a mixed sample while avoiding common drawbacks associated with other DEP designs. Using the device, a mixed sample of bacteria and 3 μm polystyrene spheres were isolated from each other and a Raman spectrum of the trapped bacteria was acquired, indicating the potential for cDEP‐Raman devices to decrease the analysis time of bacteria.     

Contingent derivatives and regularization for noncoercive inverse problems

Abstract

We study the inverse problem of parameter identification in noncoercive variational problems that commonly appear in applied models. We examine the differentiability of the set-valued parameter-to-solution map using the first-order and the second-order contingent derivatives. We explore the inverse problem using the output least-squares and the modified output least-squares objectives. By regularizing the noncoercive variational problem, we obtain a single-valued regularized parameter-to-solution map and investigate its smoothness and boundedness. We also consider optimization problems using the output least-squares and the modified output least-squares objectives for the regularized variational problem. We give a complete convergence analysis showing that for the output least-squares and the modified output least-squares, the regularized minimization problems approximate the original optimization problems suitably. We also provide the first-order and the second-order adjoint method for the computation of the first-order and the second-order derivatives of the output least-squares objective. We provide discrete formulas for the gradient and the Hessian calculation and present numerical results.     

基于MnO2/石墨烯纳米材料的表面辅助激光解吸电离质谱在内毒素快速鉴定中的应用

利用大肠埃希菌（E.coli O111：B4）中提取精制的内毒素（Control standard endotoxin，CSE）为研究对象，以MnO₂/石墨烯（MnO₂/G）纳米复合材料为基质，建立了一种基于MnO₂/G纳米材料的表面辅助激光解吸电离质谱（Surface-assisted laser desorption ionization mass spectrometry，SALDI-MS）的内毒素检测新方法.利用SALDI-MS方法可实现对不同注射液和饮用水中内毒素的快速鉴定与定量分析.与传统的鲎试剂检测方法相比，基于MnO₂/G纳米复合材料的SALDI-MS方法具有操作简便、灵敏度高、分辨率高、检测速度快、高通量和耐盐性好等优点，有望应用于更多食品和药品中细菌内毒素的高通量快速筛查.