光学双稳性临界点的相变行为

本文详细地讨论了光学双稳性(OB)的临界现象。理论分析主要以忽略量子涨落的Fokker-Plank方程的静态解为基础。结果发现,OB的临界现象可以纳入Landau二级相变理论的框架,并且有关临界指数之间的关系也服从标度律。 关键词：     

指向学习体验的物质及其转化复习的教学实践——以“钠及其化合物”为例

学习体验是学生对学习内容、过程、方法、意义的自我感受和评估,对学生学习志趣、学习素养提升有积极正向作用。以钠及其化合物复习为例,将各类别物质间转化关系的构建、物质制备原理和条件的优选作为学习体验对象,依据学习体验的内在发展历程设计学习任务及活动,引导学生亲身体验学科认知方式、学科思维方法、学科应用价值,评价体验结果,激励学生自主学习发生。     

Near-ultraviolet photolysis of L-mandelate, formation of reactive oxygen species, inactivation of phage T7 and implications on human health

Compared with ultraviolet B and C, UVA is considered to have little direct effects on biological systems. However, damaging effects of UVA on biological systems are often synergistically enhanced in the presence of sensitizers. Production of reactive oxygen species (ROS) has been implicated in the process. Several ROS have been identified but their involvement in inducing cellular damage is yet to be fully evaluated. Although membranes and proteins are affected, DNA is an important target and a variety of types of damage have been reported. Here, we present evidence that L-mandelate can act as a near UV (NUV) sensitizer, when activated by a lamp emitting 99% UVA and 1% UVB. Although evidence is available that H(2)O(2) and a small amount of *OH are produced, an alternative effect of the sensitization reaction may involve direct electron transfer. Studies have shown that NUV photolysis of mandelate can inactivate phage T7. Employment of tetrazolium blue test to detect superoxide anion may not be sufficient evidence as this agent may be reduced by alternative routes.     

超高效液相色谱-电喷雾离子源-串联三重四极杆质谱分析饮用水中的高氯酸盐

建立了超高效液相色谱-电喷雾离子源-串联三重四极杆质谱(UPLC-ESI MS/MS)分析饮用水中高氯酸盐的方法.以300Extend-C18为分析柱,10%甲醇水溶液为流动相,ESI MS/MS串联质谱为检测器,以多重反应监测(MRM)模式监测高氯酸盐m/z 99.5→82.9离子对.方法的线性范围为0.2 ～10 μg/L,相关系数为r2=0.999 9,方法检出限为0.15 μg/L,平均加标回收率为82%,相对标准偏差为4.4%.应用UPLC-ESI MS/MS法测定北京市部分城区饮用水中的高氯酸盐,其中5个水样中检出ClO-4,质量浓度为0.040 ～0.262 μg/L,但在安全阈值范围内,不会对居民健康构成威胁.     

原子相干态中的压缩现象

计算表明,与场的相干态类似的原子相干态,具有不同于场的相干态的压缩行为;进一步证明:直接类比于(?)(ξ)不能得到“原子压缩算符”.     

A real-time monitoring approach for bivariate event data

Early detection of changes in the frequency of events is an important task in many fields, such as disease surveillance, monitoring of high-quality processes, reliability monitoring, and public health. This article focuses on detecting changes in multivariate event data by monitoring the time-between-events (TBE). Existing multivariate TBE charts are limited because they only signal after an event occurred for each of the individual processes. This results in delays (i.e., long time-to-signal), especially when we are interested in detecting a change in one or a few processes with different rates. We propose a bivariate TBE chart, which can signal in real-time. We derive analytical expressions for the control limits and average time-to-signal performance, conduct a performance evaluation and compare our chart to an existing method. Our findings showed that our method is an effective approach for monitoring bivariate TBE data and has better detection ability than the existing method under transient shifts and is more generally applicable. A significant benefit of our method is that it signals in real-time and that the control limits are based on analytical expressions. The proposed method is implemented on two real-life datasets from reliability and health surveillance.     

离子色谱法测定蓝藻培养液中有机酸和无机阴离子

建立了一种利用阴离子交换色谱柱分离,电导检测器同时测定17种有机酸和7种阴离子的方法。采用Ionpac AS11-HC阴离子交换柱,KOH溶液作为淋洗液,梯度洗脱,流量为1.0mL/min,柱温为30℃,进样体积为25μL。24种分析物测定结果的相对标准偏差在0.31%~2.67%之间,线性相关系数均大于0.996,平均加标回收率在80.3%~108.5%之间。该方法可用于微生物培养液中有机酸和阴离子的同时测定。     

Phospholipids from some common fungi associated with damp building materials

Methods for the analysis of fungal biomass in contaminated building materials have been limited to methods that use viable propagules as well as indicators of total biomass such as fungal glucan and ergosterol. Because of large differences in the survival times of spores, and limitations imposed by the use of agar media to assess fungal cells for the former approach, no quantitative information and poor qualitative information is obtained. The use of the biochemical indicators provides reliable quantitative information but no qualitative data. Analysis of phospholipids of various bacteria and, recently, of fungi common in outdoor air has provided both qualitative and quantitative data on their distributions in various substrates including in outdoor air samples. In this report, we provide new data on the signature lipids of some fungi common on moldy building materials. Using the LC/MS/MS analysis described, an estimate can be made of the fresh weight of fungal cells and the relative abundance of the common genera of fungi typically found on moldy materials.     

Detecting and classifying outliers in big functional data

Advances in Data Analysis and Classification - We propose two new outlier detection methods, for identifying and classifying different types of outliers in (big) functional data sets. The proposed...