A novel radiant source for infrared calibration by using a grooved surface

A radiant source with a large aperture at 5-95 ℃ in the wavelength bands of 8-12μm for calibrating infrared imaging systems has been designed. The effective emissivity of its flat bottom with concentric V-grooves was evaluated by the Monte-Carlo method whose correctness was tested and accuracy was discussed. The structure of the source was completed by incorporating the simulation results with the blackbody cavity effect. The source was certificated via an optical measurement system. The source can provide a consistent radiant flux with temperature uniformity of ±0.1 ℃ over an area of diameter of φ80 mm.     

2-溴代对苯二甲酸根桥联双核钴(Ⅱ)配合物的合成、磁性及抗癌活性

合成了三种以２－溴代对苯二甲酸根为桥联配体的新型双核钴（Ⅱ）的配合物，即［Ｃｏ２（ＢＴＰ）（ｐｈｅｎ）４］（ＣｌＯ４）２·Ｈ２Ｏ（配合物１）、［Ｃｏ２（ＢＴＰ）（Ｎｐｈｅｎ）４］（ＣｌＯ４）２·２Ｈ２Ｏ（配合物２）和［Ｃｏ２（ＢＴＰ）（Ｂｐｙ）４］（ＣｌＯ４）２·２Ｈ２Ｏ（配合物３）（ＢＴＰ＝２－溴代对苯二甲酸根，ｐｈｅｎ＝１，１０－菲罗啉，Ｎｐｈｅｎ＝５－硝基－１，１０－菲罗啉，Ｂｐｙ＝２，２′－联吡啶）。使用元素分析、ＩＲ、ＵＶ－Ｖｉｓ光谱和电导测定方法对该配合物进行了表征。测定了配合物的变温磁化率，并对所得数据进行了理论分析，求得了配合物１、配合物２和配合物３的自旋磁交换积分分别为：２Ｊ＝－６．５ｃｍ－１，２Ｊ＝－７．８ｃｍ－１和２Ｊ＝－８．９ｃｍ－１。对该三配合物进行了体外抗人白血病癌细胞的实验。发现该三配合物均具有一定的抑制癌细胞的活性     

'LC-electrolyte effects' improve the bioanalytical performance of liquid chromatography/tandem mass spectrometric assays in supporting pharmacokinetic study for drug discovery

The development of rapid and sensitive bioanalytical methods in a short time frame with acceptable levels of precision and accuracy is imperative for successful drug discovery. We previously reported that the use of a mobile phase containing an extremely low concentration of ammonium formate or formic acid increased analyte electrospray ionization (ESI) response and controlled against matrix effects. We designated these favorable effects 'LC-electrolyte effects'. In order to support rapid pharmacokinetic (PK) studies for drug discovery, we applied LC-electrolyte effects to the development of generic procedures that can be used to quickly generate reliable PK data for compound candidates. We herein demonstrate our approach using four model tested compounds (Compd-A, -B, -C, and -D). The analytical methods involve generic protein precipitation for sample clean-up, followed by application of fast liquid chromatographic (LC) gradients and the subsequent use of electrospray ionization tandem mass spectrometry (ESI-MS/MS) for individual measurement of the tested compounds in 20-microL plasma samples. Good linearity over the concentration range of 1.6 or 8-25000 ng/mL (r(2) > 0.99), precision (RSD, 0.45-13.1%), and accuracy (91-112%) were achieved through the use of a low dose of formic acid (0.4 mM or 0.015 per thousand) in the methanol/water-based LC mobile phase. The analytical method was quite sensitive, providing a lower limit of quantification of 1.6 pg on-column except for Compd-C (8 pg), and showed negligible ion suppression caused by matrix components. Finally, the assay suitability was demonstrated in simulated discovery PK studies of the tested compounds with i.v./p.o. dosing of rats. This new assay approach has been adopted with good results in our laboratory for many recent discovery PK studies.     

红外光谱原位跟踪活性自由基聚合反应过程研究

使用新型可插入式红外光谱仪原位检测在4－羟基2，2，6，6－四甲基氧化哌啶醇（HTEMPO）存在下苯乙烯稳定自由基活性均聚合反应和苯乙烯／甲基丙烯酸羟丙酯的共聚合反应以及苯乙烯原子转移活性自由基聚合（ATRP）反应三个过程，分别考虑了它们的反应动力学，并给出了可能的聚合反应机理。研究结果表明，对于均相的苯乙烯（St)均聚合反应和苯乙烯（St)/甲基丙烯酸羟丙酯（HPMA）的自由基共聚合反应体系，聚合反应显示一定的诱导期，与反应体系中存在的HTEMPO捕捉自由基有关，而对于St／HPMA共聚合体系，诱导期更长，这是因为HPMA易和HTEMPO自由基发生氢转移反应，导致游离的HTEMPO浓度升高。最后用红外光谱实时跟踪苯乙烯非均相ATRP过程，发现苯乙烯聚合反应动力学接近于表现零级。因为单体分子在由增长自由基、卤化铜和联二吡啶形成的络合物的界面增长，与单体相内St浓度无关。     

Measurement of thermophysical properties by a pulse-heating technique

A technique is described for the dynamic measurement of selected thermophysical properties of electrically conducting solids in the temperature range from 1100 K to the melting point. Based on rapid resistive self-heating of the specimen from room temperature to any desired high temperature in several seconds by the passage of an electical current pulse through it, this technique measures the pertinent quantities such as current, voltage, randiance temperature, with sub-millisecond time resolution. The pulse-heating technique is applied to strip specimens. The radiance temperature is measured by high-speed pyrometry,normal spectral emissivity of the strips is measured by integrating sphere reflectometry. The normal spectral emissivity results are used to compute the true temperature of the specimens. The heat capacity,electrical resistivity, total hemispherical emissivity are evaluated in the temperature range from 1100 K to the melting point.     

在SN2反应中为什么Nu从背面进攻

饱和碳原子上的亲核取代反应有两类基本的反应机理,即单分子亲核取代反应(SN1)和双分子亲核取代反应(SN2).它们都是由Ingold C K和Hughes E D经过大量研究工作后提出的,有动力学实验、动态立体化学实验、同位素示踪实验的大量实验数据支持,已为广大有机化学家所接受,并广泛用在教科书中.     

多模激光束通过时间变化相位片变换的数值分析

根据衍射积分公式,对连续多模激光束通过随时间变化相位片的变换特性进行了数值模拟,详细地讨论了相位片单元尺寸和相位变化频率对多模光束光滑和能量分布的影响。数值模拟结果很好地解释了实验结果。     

Fast algorithm of discrete gyrator transform based on convolution operation

The expression of gyrator transform (GT) is rewritten by using convolution operation, from which GT can be composed of phase-only filtering, Fourier transform and inverse Fourier transform. Therefore, fast Fourier transform (FFT) algorithm can be introduced into the calculation of convolution format of GT in the discrete case. Some simulations are presented in order to demonstrate the validity of the algorithm.     

Decrease in the Particle Size and Coercivity of Self‐Assembled CoNi Nanoparticles Synthesized Under a Repulsive Magnetic Field

Towards the challenge for synthesis of smaller‐sized heterostructures and hybrid composites for nanomagnets and magnetic fluid applications. Here, a novel method is reported to reduce the particle size of Cobalt–Nickel (CoNi) magnetic nanoparticles by placing them between a static, repulsive magnetic field (N–N/S–S) during synthesis in contrast to the conventional method of applying an attractive (N–S) magnetic field. The obtained smaller sized‐CoNi nanoparticles (≈40 nm) possess a uniform size, an excellent monodispersity, and outstanding magnetic properties. The results clearly demonstrate that the size and morphology change of CoNi nanoparticles have great influence on their magnetic properties. This study provides a footprint to design new heterostructured magnetic nanomaterials under the same‐poled magnetic field for potential applications in magnetic fluids, spintronics, and other related industries.