UHPLC-ESI-MS/MS法测定动物源食物提取物中肌肽与鹅肌肽的含量

建立了一种同时测定动物源提取物中肌肽(Carnosine)和鹅肌肽(Anserine)含量的超高效液相色谱-电喷雾串联三重四极杆质谱(UHPLC-ESI-MS/MS)分析方法。采用超高效液相分离系统,借助Inertsil Amide HP色谱柱(2. 1 mm×100 mm,3μm)以0. 1%乙酸水溶液-乙腈为流动相,梯度洗脱分离,利用峰面积外标法定量。经过优化,肌肽和鹅肌肽在1. 95～500μg/L质量浓度范围内与峰面积呈良好的线性关系,相关系数(r)均大于0. 998。肌肽和鹅肌肽的检出限分别为0. 12、0. 47μg/L。以低浓度低聚肽原料为基质,在低、中、高3个加标浓度下,肌肽的回收率为99. 3%～109%,相对标准偏差(RSD,n=6)为0. 98%～1. 1%;鹅肌肽的回收率为100%～113%,RSD为1. 0%～1. 1%。该法前处理简单、快速,重现性好,准确度高,适用于动物源食物提取物中肌肽和鹅肌肽的同时快速检测。     

影响反相微乳液导电性能的因素

分别以聚乙二醇辛基苯基醚(Triton X-100)或十六烷基三甲基溴化铵(CTAB)为表面活性剂, 与正己烷、正己醇和水构成反相微乳液. 研究了水相H+浓度、表面活性剂、助表面活性剂等对微乳液导电性能的影响. 结果表明, 增加水相H+浓度可大幅度提高反相微乳液的导电能力, 当H+浓度由1.0 mol•L-1增加到10 mol•L-1时, 微乳液的电导率可提高1~2个数量级. 当水相H+浓度为10 mol•L-1时, 微乳液的电导率随溶水量的增大而增大, 水油体积比为3:10时, 两种体系的电导率均达到3200 μS•cm-1. Triton X-100浓度对微乳液的电导率影响较大, 电导率随其浓度增加而增大；而CTAB浓度对微乳液电导率的影响较小, 电导率随其浓度增加略有减小；助表面活性剂正己醇使非离子型反相微乳液的电导率下降, 而使阳离子型反相微乳液的电导率先增大, 然后减小, 呈骆峰状变化.     

Fluorescence Quenching of Poly[2-methoxy-5-（2′-ethylhexoxy）-p-phenylene vinylene] （MEH-PPV） in Solutions

Fluorescence quenching processes of poly[2-methoxy-5-(2‘ethyl-hexoxy)-p-phenylene vinylene] (MEH-PPV) in solution by electron acceptors, O2 and acid, have been studied. Static quenching of the fluorescence from MEH-PPV by an electron acceptor (DDQ or TCNE) occurs due to electron transfer from MEH-PPV to the electron acceptor and this electron transfer quenching can be promoted by chloroform. Photooxidation takes place in the MEH-PPV solution and singlet oxygen is an intermediate in the photooxidation, according to the results of ESR spectroscopy. Acid also plays an important role in the fluorescence quenching process of MEH-PPV, by the protonation of the alkoxy groups in the molecular chain.     

用非等温DSC估算3,4-双(4’-硝基呋咱-3’-基)-2-氧化呋咱(BNFOF)放热自催化分解反应的热爆炸临界温升速率和动力学参数

A method of estimating the kinetic parameters and the critical rate of temperature rise in the thermal explosion for the autocatalytic decomposition of 3,4-bis（4＇-nitrofurazan-3＇-yl）-2-oxofurazan （BNFOF） with non-isothermal differential scanning calorimetry （DSC） was presented. The rate equation for the decomposition of BNFOF was cstablished, and information was obtained on the rate of temperature increase in BNFOF when the empiric-order autocatalytic decomposition was converted into thermal explosion.     

炭化条件和铁系添加剂对炭分子筛性能影响的研究

炭分子筛(ＣａｒｂｏｎＭｏｌｅｃｕｌａｒＳｉｅｖｅ,以下简称ＣＭＳ)是具有特别发达的微孔结构的特种活性炭,在气体分离方面有广阔的应用前景[1]。目前作为变压吸附空气分离技术的首选吸附剂,在国内外被广泛用于中小规模的空气分离以制取富Ｎ2气体,制取ＣＭＳ的原料多是椰子壳、果核、植物、石油沥青及各种煤等[2,3]。煤是一种具有较为发达的孔隙结构的物质,且价格低廉,来源广泛,是制取ＣＭＳ的一种较为理想的原料。鸡西地区拥有丰富的煤炭资源,开发煤炭的深加工及高附加值产品具有十分重要的意义。本文以鸡西地区的烟煤为原料,制备空…     

固定床吸附分离山梨酸的开发研究

本文就固定床吸附分离山梨酸的工艺过程进行了开发性研究:选用了南开大学研制的H—103大孔吸附树脂,就吸附动力学曲线和吸附透过曲线进行了研究;以紫金Ⅱ型微机、BASIC语言、最小二乘法回归了有关公式;并以此研究结果对中试装置的固定床进行了计算而获得了满意的结论。     

惰性气氛下准东煤Na/Ca释放特性的研究

基于准东煤中Na/Ca的赋存形态，采用管式加热炉研究了准东煤中Na/Ca在惰性气氛下的释放特性和形态转变。结果表明，水溶态Na_w在加热温度t ≤ 600℃时先转变成不可溶态Na_re，随着温度升高，不可溶态Na_re又重新转变成水溶态Na_w，当加热温度t > 800℃时，Na大量释放。酸溶态Ca_ac在加热温度t ≤ 700℃时先分解生成CaO并且与其他矿物组分反应转变成不可溶态Ca_re，随着温度升高，不可溶态Ca_re逐渐转变成酸溶态Ca_ac和水溶态Ca_w。相同温度条件下，Ca的释放率低于Na的释放率，少量酸溶态有机Ca随挥发分释放而以气相形式释放。     

Synthesis of Pr-doped ZnO nanoparticles: Their structural,optical, and photocatalytic properties

Undoped and praseodymium-doped zinc oxide(Pr-doped ZnO)(with 2.0-mol%–6.0-mol% Pr) nanoparticles as sunlight-driven photocatalysts are synthesized by means of co-precipitation with nitrates followed by thermal annealing.The structure, morphology, and chemical bonding of the photocatalysts are studied by x-ray diffraction(XRD), scanning electron microscopy(SEM) with energy dispersive x-ray emission spectroscopy(EDS), x-ray photoelectron spectroscopy(XPS), and Fourier transform infrared spectroscopy(FTIR), respectively. The optical properties are studied by photoluminescence(PL) and UV-vis diffuse reflectance spectroscopy(UV-vis DRS). We find that Pr doping does not change the crystallinity of ZnO; but it reduces the bandgap slightly, and restrains the recombination of the photogenerated electron–hole pairs. The photocatalytic performance of the photocatalysts is investigated by the photodegradation reaction of 10-mg/L rhodamine B(RhB) solution under simulated sunlight irradiation, showing a degradation rate of 93.75% in ZnO doped with6.0-mol% Pr.     

包含夸克碎块效应的相对论性流体力学方程组的数值解法

采用守恒型差分方法求解带源项的相对论性流体力学方程组，给出了差分离散化的详细步骤，同时在计算过程中计入了ＱＧＰ相变的影响，得到反映物理现象的若干图象，并与相关文献结果进行了比较 。     

具有无穷时滞退化微分系统的周期解

讨论具有无穷时滞的非线性退化微分系统E(t)x(t)=A(t)x(t) integral from n=-∞to 0(H(t,s)x(t s)ds f(t,x_t)).的周期解问题.利用矩阵测度和Krasnoselskii不动点定理获得了系统存在周期解的充分条件,并且实例说明了所得结果的有效性.