新一代多道X射线荧光分析仪的研制

介绍的新一代 2 0 4 8道X射线荧光 (XRF)分析仪是以Amptek公司研发的Si PIN电致冷半导体探测器为X射线探测器 ,以放射性同位素源为X射线荧光激发源 ;采用 16位高速ADC以及最新推出的EZ USB系列控制器来架构多道脉冲幅度分析器 ;主机采用超薄型简化配置的笔记本计算机 .在野外或室内无液氮冷却的条件下都能够实现对矿物等待测样品的测定 ,且一次可以对十余种元素进行定性、定量分析。其检出限能够达到 1～ 2× 10 -4,分析精度可达 2 %～ 8% .     

有机荧光防伪材料的制备

１引言随着社会的不断进步,工农业的发展,档次各异、琳琅满目的商品在促进商品经济高速发展的同时,也满足了人们不断提高的物质生活水平的需要。然而,令人讨厌的伪品也龙蛇混杂地进入了流通市场。伪币、伪票、伪商标掩护下的伪品以及伪证书等常使人受骗,蒙受损失。因...     

场效应管电位滴定检测仪的研制

介绍了用场效应管研制的电位滴定终点检测仪的工作原理，性能及其应用。     

小型黄曲霉毒素检测仪的研制

针对当前黄曲霉毒素检测方法中,中低端仪器无法实现多组分定量分析,高端仪器因价格高、体积大而无法在小型实验室推广的现状,开展了黄曲霉毒素专用检测仪的研制工作。设计并搭建了基于胶束电动色谱-发光二极管诱导荧光检测系统的仪器架构,对关键光学元件等进行了组合选择,以紫外发光二极管为光源,BP 365和BP 430分别为光源和荧光滤光片,多模石英光纤传导荧光信号,光电倍增管检测信号,并对胶束电动分离系统的缓冲溶液成分等进行了优化,实现了常见6种黄曲霉毒素的基线分离。在0.1~10μg/L浓度范围内,标准溶液的浓度与荧光响应的峰面积之间呈较好的线性关系,相关系数(r)均大于0.99;峰面积的日内相对标准偏差(RSD)为2.0%~2.4%,日间RSD为5.1%~6.0%。对6种黄曲霉毒素的检出限为0.3~0.8μg/kg,加标回收率为85.3%~97.0%。该仪器具有体积小、造价低、无需衍生化反应及大量有机试剂等特点,适用于食品中多种黄曲霉毒素的同时定量检测。     

含Si—N四环的硅—硅链高聚物的研究

采用β-苯乙基甲基二氯硅烷、二苯基二氯硅烷和N,N′-双(二甲基氯硅烷基)四甲基环二硅氮烷,在甲苯中与金属钠作用缩合成两种含Si—N四环的Si—Si链聚合物。这些聚合物分子量高、熔融温度低,溶解性及热成形性好,用溶液涂膜得到具有一定强度、柔性和弹性的透明薄膜。将有机配位体加入到聚合物溶液中,其紫外光谱表明两者形成了CT复合物。     

纳米分辨率的三维形貌检测仪

从光干涉方式，瞳窗关系和光源带宽等基本关系出发，利用空间不变系统理论解析了相移显微干涉检测系统中衍射效应的影响。为了减小横向分辨率对纵向分辨率的影响，利用相关信息提取或数字滤波的方法，获得了纳米分辨率的三维形貌。     

简易"纯水导电检测仪"的制作

化学是一门以实验为基础的学科。课堂教学中 ,演示实验是课堂教学的重要组成部分。它不仅直观、容易理解、说服力强 ,而且可以调动学生积极思维 ,激发学生的学习兴趣。多年来 ,无机化学教材中 ,在讲述“水的电离”时 ,常提到“通常认为纯水不导电 ,但用精密仪器测定时 ,发现水有微弱的导电性……”。这部分内容没有演示实验 ,不仅教师讲授觉得空洞 ,学生也很难理解。由于各方面条件的限制 ,一般学校没有这种精密的仪器 ,为了满足教学上的需要 ,我们自制了简易的纯水导电检测仪。简易纯水导电检测仪取材容易 ,成本低廉 ,制作简单 ,容易操作 ,…     

内场致发射电极的电化学行为

在N-Si和P-Si半导体上用化学沉积法制备了内场致发射电极并研究了它们的电化学行为。从分解电势Ⅰ～Ⅴ曲线可知,这种电极可在低于1.23V下分解水;对Fe~(3+)/Fe~(2+)体系的循环伏安图,其峰电流为铂电极的8倍多。     

聚乳酸荧光防伪纤维的制备及其性能

通过熔融纺丝法成功制备了聚乳酸荧光防伪纤维。分别采用DSC、XRD、纤维强度仪、荧光光谱仪、荧光显微镜等探讨了荧光粉含量对聚乳酸荧光防伪纤维的结晶结构、力学性能与荧光性能的影响,并利用激光共聚焦显微镜对防伪纤维进行了3D荧光分布模拟分析。研究结果表明:聚乳酸荧光防伪纤维在紫外光激发下,在530nm处出现最强发射峰,纤维呈黄绿色荧光;随着荧光粉含量的增加,纤维的荧光强度增加,但荧光粉在基体中的团聚现象逐渐加剧,纤维的断裂强度逐渐降低;激光共聚焦显微镜可较好地模拟荧光防伪纤维中荧光粉的分布情况。     

Development of a Microsphere-Based Immunoassay Authenticating A2 Milk and Species Purity in the Milk Production Chain

Processed milk and milk products produced from bovine milk, commonly contain β-casein A1 (βCA1) and β-casein A2 (βCA2). Since the presence of βCA1 is linked to milk intolerance and digestion problems, A2A2 milk, which only contains βCA2, is proposed as a healthier alternative. To support this health claim, the purity of A2A2-milk has to be guaranteed. In the presented study, a multiplex immunoassay, able to distinguish between βCA2 and βCA1, was developed and real-life applicability was shown on raw milk samples from genotyped A1A1, A1A2 and A2A2 cows. Because of its ability to discriminate between βCA2 and βCA1, this newly developed method was able to detect the addition of common bovine A1A2 milk to A2A2 milk, as low as 1%. Besides the detection of A2A2 milk purity, the developed assay can also be implemented as a rapid phenotyping method at dairy farms to replace the more invasive DNA-based screening. Additionally, the developed method was capable of detecting the addition of common bovine milk up to 1% in sheep, goat, buffalo, horse and donkey milk, which conforms to EU recommendations. In conclusion, a newly developed multiplex method capable of reliably detecting the dilution of A2A2 milk of multiple species, with common bovine milk up to 1%, is presented.     

高效液相色谱法测定血中苯妥英浓度

A high performance liquid chromatographic method for the quantitative analysis of phenytoin(PHT) inhuman plasma or whole blood is described. After a onestep extraction of PHT and internal standard withethyl acetate from human plasma or whole blood,samples were chromatographed on a Spherisorb-C(18) columnwith a mobile phase of methanol-water-tetrahydrofuran(45/55/5,V/V/V)at a flow rate of 0. 3mL/min. Theeluant was monitored at 210nm.     

新型电致化学发光分析仪的研制

新型电致化学发光分析仪可以应用在实验室条件下的药物分析、发光材料等一类电化学发光的检测实验中．系统地介绍了电致化学发光分析仪的设计和研制过程,包括仪器原理、设计框图、具体实现方案、主要技术难点和创新点．仪器具有灵敏度高、双检测位置、四样品通道、三维图形显示等特点。     

Is the ˜c state of CH2 linear or bent?

The ˜c state of CH₂ is found to be bent at the highest levels of theory used in this work, but the energy difference between the linear and bent geometries is only about 10 cm⁻¹. Improving the basis set or correlation treatment favors the linear geometry over the bent, thus it is impossible to definitively determine if the ˜c state has a barrier in its bending potential. If there is a barrier, it is clear that it will be so small that the ˜c state will be quasilinear. Received: 3 September 1996 / Accepted: 23 September 1996     

双波长分光光度法测定有机弱酸弱碱的解离常数

本文提出了一种测定有机一元弱酸弱碱解离常数的新方法———双波长分光光度法。该方法是在选定的一对工作波长下测定相同浓度不同pH值的有机一元弱酸弱碱水溶液的吸光度,利用所推导的公式作图求得pKa(或pKb)。利用本方法测定了甲基橙、溴甲酚绿、苯酚和苯胺等多种常见的有机一元弱酸弱碱的解离常数,结果十分满意。与传统的单波长分光光度法相比,双波长法测定结果的精密度和准确度更高。     

Instrument for the mechanization of the capillary radioimmunoassay

Ohne Zusammenfassung

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Instrument for the mechanization of the capillary radioimmunoassay

     

手性单双糖Schiff碱的合成及抑菌活性研究

多糖、寡糖、Schifr碱及其配合物具有抗癌、抗病毒、杀菌等生物活性。酰肼类化合物可与生物体中的微量元素作用达到抗结核和抗肿瘤效果。在酰肼Schiff碱分子中引入单双糖分子,不仅可增加水溶性,降低毒性,引入手性源,     

FIA-3100流动注射仪数据采集系统的开发及其应用

介绍了一种数据采集系统,阐述了系统组成、实现和主要功能,并结合梯度稀释技术介绍了其在火电厂炉水磷酸根测定中的应用．     

An innovative strategy for the synthesis of a new series of potent aminopeptidase (APN or CD13) inhibitors derived from the oxepin-4-one family

Derivatives from the aminobenzosuberone family have been recently synthesized and recognized as highly selective inhibitors of aminopeptidase N (APN)/CD13 (EC 3.4.11.2), an important target for cell migration processes involved in particular in tumor invasion. We present here a much more straightforward synthesis of analogues belonging to a novel isosteric oxo series which also possesses excellent inhibitory potential against APN. Their synthesis, as reported here, relied on an interesting iodine(III)-mediated rearrangement originally described by Koser and Justik as the key step. This represents the second application of this rearrangement in medicinal chemistry.     

叶绿素-a衍生物的化学反应和多取代卟吩(啉)合成的研究进展

天然产物叶绿素-a衍生物所具有的特殊理化性质以及连带多种活性取代基团的非对称性骨架结构, 决定其化学反应的活泼性和实际应用的广泛性. 基于以叶绿素-a及其衍生物为研究对象的化学反应和结构修饰, 综述了近期多取代卟吩(啉)合成的研究进展.