An accurate and reliable analysis of trimethylamine using thermal desorption and gas chromatography–time of flight mass spectrometry

Trimethylamine (TMA) is well-known for manifesting the odor of rotting fish and urine. The analysis of TMA in environmental samples generally suffers from low reproducibility and poor sensitivity. In this study, a technique for the quantitative analysis of gas phase TMA was developed using thermal desorption (TD)-gas chromatography (GC)-time of flight mass spectrometry (TOF-MS). This new approach yielded good linearity (R² = 0.9930), precision (RSE = 1.59%), and high sensitivity with the method detection limit (MDL) of 51 pg, i.e., detection of 0.021 ppb of TMA at 1 L sample (limit of detection (LOD): 5.32 pg (0.002 ppb). This method was tested against gas samples collected from two representative sources of TMA: (1) rotten thornback fish and (2) cat urine-soaked clay. The concentration of TMA in these samples, when analyzed after treatment at varying dilution ratios, averaged 293 ± 29.7 ppm (RSE = 3.82%) and 74.1 ± 5.78 ppb (RSE = 3.19%), respectively. The feasibility of this approach, when tested with TD–GC–Quadruple (Q) MS, showed a good compatibility with moderately reduced sensitivity. The results of this study demonstrated that one can achieve highly reliable and reproducible analysis of TMA from environmental samples when using thermal desorption (for pretreatment) and detection (by the TOF or Q-MS system).     

基于ST5516芯片的KVM虚拟机移植

简单介绍ST5516芯片、ST的OS20操作系统、适合于机顶盒环境的JAVA虚拟机-KVM，给出了KVM移植到基于ST5516芯片的有线数字电视机顶盒上的方案及具体实现过程。     

基于C167的点阵液晶显示的设计与实现

介绍了微控制器C167CR和液晶显示控制器ST7920的特点,给出了基于CPLD（Complex Pro-grammable Logic Device）实现并口直接访问的硬件接口方案。在KeilμVision3集成开发环境下采用C语言编写了ST7920的驱动控制程序和液晶显示程序,成功地实现了中文、字符和图形的显示,具有较强的可移植性。     

sST2在脓毒症中的变化及临床意义

目的通过检测脓毒症患儿血液可溶性ST2(sST2)的水平,探讨其在脓毒症中的临床意义.方法采用ELISA法分别检测不同程度脓毒症患儿血液中sST2的水平.同期将健康体检的儿童列为对照组,检测其sST2水平.结果 sST2浓度在脓毒症组为(3.64±0.55)pg/dl、脓毒症伴休克组为(4.38±0.84)pg/dl、脓毒症伴多脏器损害组(7.23±2.18)pg/dl,正常对照组为(1.92±0.67)pg/dl,脓毒症患儿血液中sST2水平与对照组差异有统计学意义(P<0.01),不同程度脓毒症患儿的sST2水平差异也有统计学意义(P<0.01).结论 sST2参与了全身炎症反应的过程,且与疾病的严重程度有关,检测血液中sST2水平可预测脓毒症的严重程度,反映病情变化及预后.     

互动互联：保持机顶盒市场增速的动力

目前中国拥有电视的家庭为3亿9500万户,2015年模拟电视业务停止后,庞大的用户群会逐步转移到IP和数字有线电视市场,以及卫星直播到户和地面DTMB市场。届时互动和连通性将成为中国机顶盒市场新高潮的核心。     

8位MCU融入“冗余＋检测”高端技术

8位MCU除了广泛用于电视机、冰箱、洗衣机及其他消费家电产品以外,工业和医疗市场的需求也在增强;同时在客观上对更高的稳定性和抗干扰性提出了要求。意法半导体（STMicroelectronics）近日宣布针对工业应用和消费电子开发的微控制器STM8S105和STM8S207全面上市。新产品以高性能的8位架构、模块化外设和引脚兼容封装的主要特性,     

广义鞍点问题的块三角预条件子

本文对Golub和Yuan(2002)中给出的ST分解推广到广义鞍点问题上,给出了三种块预条件子,并重点分析了其中两种预条件子应用到广义鞍点问题上所得到的对称正定阵,得出了其一般的性质并重点研究了预处理矩阵条件数的上界,最后给出了数值算例.     

Multiscale entropy based study of the pathological time series

This paper studies the multiscale entropy （MSE） of electrocardiogram＇s ST segment and compares the MSE results of ST segment with that of electrocardiogram in the first time. Electrocardiogram complexity changing characteristics has important clinical significance for early diagnosis. Study shows that the average MSE values and the varying scope fluctuation could be more effective to reveal the heart health status. Particularly the multiscale values varying scope fluctuation is a more sensitive parameter for early heart disease detection and has a clinical diagnostic significance.     

新型FSK电力线收发器ST7540及其应用

介绍了新型单片式FSK电力线收发器ST7540的特点及工作原理,并给出基于ST7540的应用电路。ST7540采用半双工同步/异步FSK通信方式,专为低压电力线数据传输而设计,较好地克服了低压电力线载波传输中的技术问题,可广泛应用于空间限制,成本敏感的家庭和建筑物自动化以及遥控监视系统。