锡硫属化物[M(en)3]2[Sn2Se4S2](M=Mn,Co)的溶剂热合成,晶体结构与性质表征

在乙二胺溶剂体系中,180 ℃条件下合成了两种化合物[Mn (en)3]2[Sn2Se4S2](1)和[Co(en)3]2[Sn2Se4S2](2).通过X-射线单晶衍射、SEM、IR、TGA和UV-Vis等手段对其进行了表征.X-射线单晶衍射结果表明化合物1和2是类质同晶,均为正交晶系,并属于Pbca空间群,结构中均含有Sn和两种硫属元素S、Se组成的二聚体阴离子[Sn2Se4S2]2-.两种晶体的晶胞参数分别为:化合物1,a=1.6020(8) nm,b=1.1842(6) nm,c=1.9658(10) nm,Z=8;化合物2,a=1.549t(5) nm,b=1.1688(4) nm,c=1.18666(6) nm,Z=8.紫外-可见漫反射光谱研究结果表明,化合物1和2的禁带宽度分别为1.54 eV和1.64 eV,均有半导体性能.     

Protein‐oligosaccharide conjugates as novel prebiotics

Maintaining a good proportion of gut probiotic bacteria is imperative to health. This may be achieved by consuming “prebiotics,” e.g., galacto‐oligosaccharides (GOS) that selectively promote probiotic bacteria, as they often uniquely express transporters for such oligosaccharides. Proteins are an important source for amino acids essential to probiotic bacteria. As most protein digestion products are absorbed in the small intestine, and there is great competition on the residuals by colonic bacteria, amino acids are scarce (<0.01 mM) in the colonic intercellular fluid, thus limiting probiotics' proliferation. However, no existing prebiotic product contains protein. Herein, we propose a new type of prebiotics: protein‐oligosaccharide conjugates. These conjugates were designed to be selectively targeted to probiotic bacteria in the colon, for enhancing their competitive advantage over undesired microorganisms. The approach was inspired by active targeting of chemotherapy, achieved by conjugating drugs to ligands, which selectively bind to proteins uniquely expressed on cancer cells; except here, we aimed to promote, not eliminate, the targeted cells. We formed these conjugates by mild Maillard‐reaction‐based covalent conjugation of GOS to lactoferrin hydrolysate (LFH), formed by peptic digestion, hence it resists gastric digestion. LFH‐GOS conjugates comprised 76% ± 1% LFH and 25% ± 4% GOS, and self‐assembled into 0.2 to 1.5‐μm microparticles. Most of the conjugates' protein content endured simulated gastrointestinal digestion, hence is expected to reach the colon. Remarkably, we found that the growth rate of a model probiotic bacterium (Lactobacillus casei) on the conjugates was double that on the unconjugated components (0.082 and 0.041 h^?1, respectively). This study proposes the next generation of prebiotics.     

对多油层油田合理开发程序的初步认识

一个油田,在肯定了它们的工业价值、初步探明了油田的分布面积以后,就要着手迅速地将油田投入开发。但是原油储集在地下的岩层中,油层的地质结构是非常复杂的。要合理开发油田,首先要有一个好的开发方案,要按照油田地下的实际情况确定开发方式、划分与组合开发层系、对不同的开发层系采用不同的井网布置和注水方式等等,力争打较少的井数,得到较好的开发效果。     

8-羟基喹啉衍生化β-环糊精键合硅胶液相色谱固定相的合成与评价

β－环糊精键合硅胶经对甲苯磺酰化后, 与８－羟基喹啉反应得到８－羟基喹啉衍生化β－环糊精键合硅胶固定相（ＱＣＤＳ）． 采用元素分析、热分析及固体核磁波谱对键合固定相进行表征． 考察了ＱＣＤＳ对位置异构体、丹磺酰化氨基酸异构体、苯丙酸类药物和核苷等的分离性能．     

Preparation and Evaluation of Calix[8]arene Bonded Silica Stationary Phase for High Performance Liquid Chromatography

In recent years, calix[n]arenes (n=4,5,6,7,8) as stationary phase have been introduced into the field of chromatography. In our previous works, we have synthesized, characterized and evaluated two different silica-bonded calix[n]arenes (n=4,6) stationary phase, on which the chromatographic behavior of PAHs, positional isomers,nucleosides and bases was investigated. In this paper we report the preparation of calix[8]arene bonded silica stationary phase, and characterization of its structure and chromatographic behavior.     

An analytical approach to reconstruction of axisymmetric defects in pipelines using T(0, 1) guided waves

Torsional guided waves have been widely utilized to inspect the surface corrosion in pipelines due to their simple displacement behaviors and the ability of longrange transmission. Especially, the torsional mode T(0, 1), which is the first order of torsional guided waves, plays the irreplaceable position and role, mainly because of its non-dispersion characteristic property. However, one of the most pressing challenges faced in modern quality inspection is to detect the surface defects in pipeli...     

Cs4Sn5S12的溶剂热合成与表征

利用溶剂热法合成了硫代锡酸铯Cs4Sn5S12,单晶X-射线衍射结果表明Cs4Sn5S12属正交晶系,Pbca空间群,a=1.4232(4)nm,b=1.3161(4)nm,c=1.6372(5)nm,α=90°,Z=4。化合物Cs4Sn5S12中含有由八面体Sn S6和三角双锥Sn S5连接形成的层状阴离子[Sn5S12]4-∞。[Sn5S12]4-∞结构中有两种类型硫原子:连接六配位锡原子和五配位锡原子的硫原子以及只与两个五配位锡原子相连的硫原子。紫外-可见漫反射光谱表明Cs4Sn5S12为半导体,禁带宽度为2.3 e V。     

退色光度法测定痕量Cr(Ⅲ)的研究

基于在ＯＰ存在下,痕量Ｃｒ（Ⅲ）可使萘酚绿Ｂ退色的反应,本文提出了一种应用新的退色光度法测定痕量Ｃｒ（Ⅲ）的方法,该方法线性范围为０．２４－３．００μｇ．ｍＬ＾－１,检出限为２．０５μｇ．ｍＬ＾－１。该方法用于模拟样品的测定,回收率为１００％－１０８％。     

单扫描示波极谱法测定药物中的利血生

用单扫描示波极谱法研究了利血生在碱性条件下的分解产物与Cu2 在乙二胺介质中的伏安行为 ,发现其在 - 0 .37V(vs.SCE)处有一灵敏的极谱吸附波 ,其二阶导数波的峰电流ip″大小与利血生浓度在 4.0× 1 0 -7～ 6.0×1 0 -6mol L范围内成线性关系 ,RSD为 1 .0 % ,回收率在 97.9%～ 1 0 3%之间 ,方法的检出限为1 .0× 1 0 -7mol L。探讨了反应机理 ,并用建立的方法测定了片剂中利血生的含量