交流瞬时值取样检测的设计与实现

传统电量测量的结果多是反映被测交流电量的有效值或平均值,对于瞬时值的反映,只能借用相应的示波装置才能显现但对于每个时刻的真实值检测还存在一定的问题和误差,为此提出一种基于一定电路和计算原理的方法,实现对交流电量瞬时值的取样,并达到相应的实时监测目的,易于实现高精度、快速测量及多项参量同时测量等功能.     

In vivo electrochemical impedance measurement on single cell membrane

The electrochemical characteristics of the plasma membranes of single cells and organelles were investigated. Silicon fabrication technology was used to produce a metal ultra-microelectrode (UME). Furthermore, the UME was characterized in a cell medium using electrochemical impedance spectroscopy (EIS). A single rat fibroblast cell, or chloroplast purified from Peperomia metallica leaves, was immobilized by a micropipette after which the UME was inserted into its cytosolic space through cell membrane using a piezo actuator. An in vivo EIS measurement between the UME and the counter electrode outside of a single cell was taken. The measurements were analyzed using equivalent circuits in order to estimate the membrane impedance of a single cell.     

The Wigner–Yanase information can increase under phase sensitive incoherent operations

We found that the Wigner-Yanase skew information, which has been recently proposed as a measure of coherence in Girolami (2014), can increase under a class of operations which may be interpreted as incoherent following the framework of Baumgratz et al., while being phase sensitive.     

基于移动终端的EPC识读煤矿安全系统的设计与实现

针对煤矿安全生产的信息化管理问题,本文提出了一种基于移动终端的EPC识读系统,它是基于广泛应用的移动终端上所开发的一种系统,可实现在移动终端上进行人员查询、统计、考勤和定位等管理功能。     

Anti‐static Agent Containing Zinc Oxide and its Modification for PA6 Fiber

A new anti‐static agent was synthesized from zinc oxide‐adipic acid‐polyethylene glycol and caprolactam by three‐step reactions. The antistatic agent (called poly(ether ester amide zinc oxide) or PEEAZ) was analyzed by IR and DSC. The results showed that zinc oxide existed in the main chain of PEEAZ. The glass temperature and melt temperature of poly(ether ester amide zinc oxide) (referred to as PEEAZ in the following) decreased with increasing poly(ether ester zinc oxide) increasing in PEEAZ. Antistatic PA6 fiber was obtained by adding PEEAZ 2–8% (wt/wt) to PA6 during blend spinning. The specific resistance and the static half‐value period of PA6 fiber was less than 10⁹Ω · cm and 60 sec, respectively. Excellent antistatic property remained after being washed 30 times.     

Lipid profiling of human plasma from peritoneal dialysis patients using an improved 2D (NP/RP) LC-QToF MS method

An improved online two-dimensional liquid chromatography-quadrupole time-of-flight mass spectrometry (2D LC-QToF MS) system was developed for the lipid profiling of human plasma, in which different lipid classes were separated by the first dimensional normal-phase (NP) LC and different lipid molecular species were separated by the second dimensional reversed-phase (RP) LC. This 2D LC-QToF MS system was built based on a ten-port, two-position valve as the interface, the conditions of which had been optimized and discussed in detail. As two loops were used to trap and transfer the first dimensional elute to the second dimension separately, this new interface suppressed the sample band broadening in the first dimensional column, increased the recovery and repeatability of 2D LC interface, and offered the possibility for the realization of not-stop-flow NP/RP 2D LC system. Finally, 190 endogenous lipid species out of 10 lipid classes were determined within a single run from the plasma of peritoneal patients. This method was also applied to identify the difference in lipid profile between plasma from peritoneal dialysis patients with bad volume status and peritoneal dialysis patients with good volume status. The discovery of 30 potential biomarkers would be helpful to the malnutrition, inflammation, and atherosclerosis syndrome investigation.     

Rapid determination of α‐tocopherol in cereal grains using dispersive liquid–liquid microextraction followed by HPLC

The traditional for the determination of α‐tocopherol in cereal grains includes saponification of a sample followed by liquid–liquid extraction, and it is time‐ and solvent consuming. In this study, a dispersive liquid–liquid microextraction (DLLME) method was developed to extract α‐tocopherol in situ from the saponified grain sample solution. The DLLME experimental parameters including the type and volume of extractants, the volume of dispersers, the addition of salt and the extraction/centrifuging time were examined and optimized. The recommended analytical procedure showed excellent precision (relative SDs of the α‐tocopherol amount of 3.1% over intraday and 7.2% over interday), high sensitivity (the detection limit of 1.9 ng/mL), and strong recovery values (88.9–102.5%). In addition, statistical analyses showed no significant difference between the detected amounts of α‐tocopherol found by the standardized method and this new procedure. The method was successfully applied to determining the amounts and distribution of α‐tocopherol in 14 cereal grain samples.     

Amicoumacins from the marine-derived bacterium Bacillus sp. with the inhibition of NO production

Chemical examination of the fermentation broth of the marine-derived bacterium Bacillus sp. resulted in the isolation of seven new amicoumacin-type isocoumarin derivatives, namely bacillcoumacins A–G (1–7), together with four known analogues. Their structures were elucidated on the basis of extensive spectroscopic analysis, while the absolute configurations of the new compounds were determined by CD, Mosher’s method, and chemical conversion. Compounds 7 and 9 showed inhibitory effects against the NO production induced by lipopolysaccharide (LPS) in mouse macrophage RAW 264.7 cells.