高效液相色谱法同时测定肉制品中的6种食品添加剂

建立了同时测定肉制品中化学性质差异较大的6种常用食品添加剂的高效液相色谱(HPLC)分析方法。根据6种添加剂(苯甲酸(钠)、山梨酸(钾)、糖精钠、安赛蜜、诱惑红和胭脂红)的化学性质,对HPLC分析条件进行了详细的优化。结果表明:以ZORBAX Eclipse Plus C18柱(150mm×4.6mm,5μm)为分析柱,以甲醇和20mmol/L醋酸铵溶液(pH为6.9)为流动相进行梯度洗脱,在235nm波长下进行检测,可以在18min内完成6种添加剂的同时测定。在高、低两个加标浓度下,样品的回收率为80.7%～94.4%,相对标准偏差(n=3)为2.0%～7.1%。结果表明,该方法快速、准确,能够同时分析测定肉制品中上述6种食品添加剂。     

硅胶表面修饰添加剂选择性降低卷烟烟气中的苯酚

分别以聚乙烯亚胺（PEI）、十六烷基三甲基溴化铵（CTMAB）对硅胶（SiO2）表面进行修饰,并以苯酚为模板,合成硅胶表面修饰分子印迹聚合物（MIP-SiO2）,制备获得功能添加剂PEI-SiO2、CTMAB-SiO2、MIP-SiO2。按不同剂量分别将功能添加剂加入到卷烟滤嘴中,考察对卷烟主流烟气中苯酚的截留效率。结果表明,各添加剂均可有效降低卷烟烟气中的苯酚释放量。当添加量达到20mg/支时,各功能材料对苯酚的截留效率均超过39%。且添加剂对烟气中苯酚的截留能力大于对烟气中焦油的吸附能力,表明功能添加剂具有选择性降低卷烟烟气中苯酚的作用。     

Diffusion interaction and quantitative analysis of zinc dialkyldithiophosphate content in lube base oils in terahertz regime

We investigate the diffusion interaction and quantitative analysis of zinc dialkyldithiophosphate (ZDDP) mixed with lube base oil (LBO) at different concentrations using terahertz time-domain spectroscopy (THzTDS).When the concentration exceeds 6.78%,the characteristic absorption peaks exhibit significantly shift,and the absorption coefficient peak value is nonlinear against concentration.Moreover,the absorption coefficients of mixed samples follow the Beer’s law at a concentration below 6.78%.The quantitative analysis enables a strategy for monitoring the formulation of lubricating oil in real time.     

A class of weighted estimators for additive hazards model in case-cohort studies

Case-cohort sampling is a commonly used and efficient method for studying large cohorts. In many situations, some covariates are easily measured on all cohort subjects, and surrogate measurements of the expensive covariates also may be observed. In this paper, to make full use of the covariate data collected outside the case-cohort sample, we propose＇a class of weighted estimators with general time-varying weights for the additive hazards model, and the estimators are shown to be consistent and asymptotically normal. We also identify the estimator within this class that maximizes efficiency, and simulation studies show that the efficiency gains of the proposed estimator over the existing ones can be substantial in practical situations. A real example is provided.     

Inhomogeneous Quantum Codes （III）： The Asymmetric Case

The stabilizer （additive） method and non-additive method for constructing asymmetric quantum codes have been established. In this paper, these methods are gen- eralized to inhomogeneous quantum codes.     

L 2-Decay rate for non-ergodic Jackson network

We establish the additive theorem of L^2-decay rate for multi- dimensional Markov process with independent marginal processes. Using this and the decomposition method, we obtain explicit upper and lower bounds for decay rate of non-ergodic Jackson network. In some cases, we get the exact decay rate.     

高效液相色谱法分离药物对映体中手性流动相添加剂的应用

综述了近年来手性流动相添加剂在高效液相色谱拆分对映体中的应用,阐述了各类手性流动相添加剂的拆分机理及其在药物分析中的应用,引用文献52篇.     

吸附式空调系统的原理及添加剂强化吸附工质性能的研究

氯化锂晶体具有很高的吸水性能，在吸附式空调制冷系统中常常被用作吸附剂。本文介绍了吸附式空调制冷系统的原理，研究了吸附剂（氯化锂）、吸附质（水汽）的性质；采用高真空吸附重量法测定氯化锂的等温吸附曲线及氯化锂吸附水汽的速率，并通过添加一种既有吸附增稠作用，又能强化氯化锂吸附性能的添加剂,改善氯化锂的等温吸附特性,降低氯化锂的再生温度。采用氯化锂混合吸附剂-水的开式旋转吸附式空调系统，具有显著的节能效果和双重杀菌功能，提供人们所喜爱的舒适空调域（室内温湿度26．7℃／50%RH），同时改善室内空气品质。     

饲料添加剂唆乙醇的合成

本文研究了n奎乙醇的合成方法.由于采用较高效率的相转移催化剂和乙醇一水作重结晶溶剂，得到高纯度，高产率的喳乙醇.