Determination of Association Constants of Cyclodextrin-Nonionic Surfactant Inclusion Complexes by a Partition Coefficient Method

The partition behavior of isotopic labeled nonionic surfactants between carbon tetrachloride and an aqueous solution containing -cyclodextrin (-CD) was studied with a liquid scintillation counting technique. The association constants of the inclusion complexes were determined at different temperatures. It was found that the nonionic surfactants form 1 : 1 inclusion complexes with -CD. The results demonstrated that the smaller the HLB values of the nonionic surfactants, the greater the association constants with -CD, and that for the same surfactant the association constant is higher at lower temperatures.     

半菁类染料敏化太阳能电池的光电化学性能研究

研究了三种不同长度碳链取代的半菁类染料2-[4-(N,N-二羧乙基)氨基]苯乙烯基-1,3,3-三甲基苯并吲哚鎓碘(BIDC1)、2-[4-(N,N-二羧乙基)氨基]苯乙烯基-1-丁基-3,3-二甲基苯并吲哚鎓碘(BIDC2)和2-[4-(N,N-二羧乙基)氨基]苯乙烯基-1-辛基-3,3-二甲基苯并吲哚鎓碘(BIDC3)敏化太阳能电池的光电化学性能。其中BIDC1的敏化效果最好,在100mW/cm2氙灯光源下,开路电压、短路电流、填充因子和转换效率分别是430mV、1.31mA/cm2、0.52、0.29%。研究表明,随着半菁染料碳链取代基的增长,光电转换效率逐渐降低。     

A novel methodology for photometric compensation of projection display on patterned screen

We propose a novel methodology based on the projector-camera (ProCam) system to address the photometric compensation issue for the projection display on the patterned screen.The patterned screen is treated as the combination of a perfect white screen and a color modulator.The perfect white screen is used to automatically and accurately characterize the ProCam system offline using the polynomial model,and the parameters of the color modulator can be efficiently recovered by employing only two gray images based on the linear reflectance model.The experimental results show that the color artifacts of the display image can be greatly improved with this methodology,which demonstrates its feasibility and validity in the photometric compensation.     

Large magnetoresistance induced by surface ferromagnetism in A-type antiferromagnetic La0.4Sr0.6MnO3 nanoparticles

Grain size effects on magnetic and transport properties for heavily Sr-doped A-type antiferromagnetic La_0.4Sr_0.6MnO₃ ceramics were studied. It was observed that with decrease in grain size, surface ferromagnetism could be introduced due to bond-breaking at surfaces. With decrease in grain size, the surface ferromagnetism was enhanced, and the phase transition order distinguished from the Arrott plot was a second one. The surface-induced ferromagnetism was insulating as judged from transport properties. With decrease in grain size, magnetoresistance was largely improved for both high magnetic and low magnetic fields. Under a 500 Oe magnetic field, the magnetoresistance is improved from 0.2%, 0.1%, 0.03% and 0.02% for the sample with grain size of 150 nm at 10, 100, 200 and 300 K, respectively, to 3%, 2.3%, 0.43% and 0.12% for the sample with grain size of 20 nm at 10, 100, 200 and 300 K. It was interesting to find that large magnetoresistance could be induced due to the surface ferromagnetism in A-type antiferromagnetic La_0.4Sr_0.6MnO₃ nanoparticles, which suggested that it was possible to search for manganites with relatively high low-field magnetoresistance in nanostructured A-type antiferromagnetic materials.     

固相萃取-超高效液相色谱分离测定洗涤用品中4种荧光增白剂

建立了固相萃取净化结合超高效液相色谱-二极管阵列检测器(UPLC-DAD)同时检测洗衣液、洗衣粉等洗涤用品中荧光增白剂351、85、28和71的分析方法。样品经2%（体积分数）甲酸水溶液-甲醇提取,经WAX固相萃取小柱净化后,采用Phenomenex Synergi Max-RP色谱柱(150 mm×2.0 mm),以乙腈-10 mmol/L乙酸铵为流动相实现待测物(包括顺式和反式异构体)的良好分离,以二极管阵列检测器检测,结合保留时间和光谱图定性,以标准曲线定量。结果表明,4种荧光增白剂在0.05～180 mg/L范围内线性关系良好,相关系数均大于0.9993;方法定量限(S/N=10)为1.5～15 mg/kg;添加水平为5～1500 mg/kg时,回收率为84.9%～105%,相对标准偏差(RSD, n=6)为3.2%～6.1%。应用本方法分析了15个样品,阳性样品检出率为53.3%。该法前处理简单,回收率高,精密度好,适用于洗涤用品中4种荧光增白剂的测定。     

用于激光等离子体诊断的硬X光能谱仪

介绍了利用滤片和探测器阵列组合的硬X光能谱仪(简称FFS)的工作原理,结构性能和数据处理。文章最后给出了FFS在惯性约束聚变(ICF)实验中测到的硬X光谱的典型结果。     

BODIPY Fluorescent Chemosensor for Cu2+ Detection and Its Applications in Living Cells: Fast Response and High Sensitivity

Copper is an essential trace element for the proper functioning of organ and metabolic process in humans. However, both its excess and deficiency in the body can result in adverse health effects. A BODIPY containing 2,2′-bipyridyl group was synthesized and used as a fluorescent chemodosimeter for selective Cu2+ detection in mild condition. This BODIPY shows fast response (~1 min) and high sensitivity for Cu2+ in aqueous solution due to the photoinduced electron transfer from the excited state of fluorophore to the bipyridyl unit complexed to Cu2+. The fluorescence quenching mechanism revealed by MALDI-TOF Mass spectra showed one Cu2+ could coordinate with two BODIPY molecules, and this coordination is reversible. This simple BODIPY dyes also could be used for sensing the Cu2+ in living cell. This work contributes to extend the potential applications of BODIPY to the biological and environmental areas.     

边坡抛掷爆破峰值质点振动速度的无量纲分析

为研究边坡抛掷爆破振动波传播过程所诱发的地表质点振动情况,运用量纲分析理论构建考虑高程影响的振动峰值速度公式,在此基础上依据边坡抛掷爆破模型将炮孔药包划分为无数微元体进行积分运算,最终得到边坡抛掷爆破振动峰值速度公式。结果显示,同一地理环境和爆破工艺条件下,峰值速度主要由炸药性能、装药深度、测点与爆源间距以及爆破作用指数所决定。同时对某边坡爆破现场进行试验测振,将实测峰值速度数据分别代入萨氏公式、3个常用萨氏修正公式以及通过无量纲理论推导出的速度公式进行非线性回归运算,得到坡表面实测值与各峰值速度公式预测值之间平均误差分别为32%、34.25%、29.58%、39%和7%,坡体内实测值与各峰值速度公式预测值之间平均误差分别为27.63%、23.5%、16.88%、33.889%和13.25%。     

纠缠态表象在热场动力学中的应用

大多数量子系统都与外界环境之间存在某种热交换或热纠缠, 受量子光学双光子纠缠态表象启发, 本文将建立热纠缠态表象. 根据 Takahashi 与 Umezawa 提出的热场动力学理论, 热场混合态可以等效为一个量子纯态.因此, 任意量子态在环境温度不为零(T ≠0) 时, 系综期望值可以等效成对量子纯态的平均值. 在温度趋向于无穷大时, 可以得到热真空态的极限形式. 类似于相干态, 利用平移算符对热真空态极限形式做平移操作后, 即可得到热相干态(也称为热纠缠态) . 热纠缠态表象可以将密度算符ρ =|m> 相似文献   

Research progress in mass spectrometry analysis for samples containing non-volatile saltsEI北大核心CSCD

It’s still a challenge for mass spectrometers （MS） to analyze samples in non-volatile salts systems. On the one hand， non-volatile salts are easy to crystallize， which will seriously contaminate and clog the transmission system of mass spectrometry， such as capillaries， ion transfer tubes， sampling cones， etc.， thus the analysis results can be affected and the MS can be damaged. On the other hand， non-volatile salts always bring ion suppression， which significantly reduces the signal intensity of the analytes. At the same time， the mass spectrum will be dominated by a large number of salt cluster peaks， interfering with the discrimination of charge state. Recently， different methods have been developed to solve above two problems. This article reviewed the present research progress of mass spectrometry analysis for salt-containing samples， focusing on the role of conventional ion source modification and ambientionization mass spectrometry in the analysis of salt-containing samples. Pretreatment methods were also summarized briefly. Finally， the development tendency of mass spectrometry analysis for salt containing samples is predicted and prospected. © 2023, Youke Publishing Co.,Ltd. All rights reserved.