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1.
为了实现氢同位素气体在线检测,利用气体低气压辉光放电性质,设计加工了氢同位素在线测定装置并建立了辉光放电原子光谱法在线测定氢同位素的分析方法。该装置由辉光放电管、激发光源、真空–微量进气系统、光谱仪及数据采集系统等部件组成。采用不同含量的系列氕氘气体作为标准气体,绘制标准工作曲线,建立了氢同位素在线检测分析方法,氕氘气体的检出限均为0.04%,氕浓度、氘浓度和氕氘浓度比测量的相对标准偏差分别为3.6%,5.2%和2.4%(n=6)。该分析装置性能稳定可靠,操作简单,可实现氢同位素气体在线检测。 相似文献
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发展了一种以微流控芯片为平台的药物诱导细胞凋亡的新方法.选择HeLa细胞为对象,通过浓度梯度芯片形成稳定的药物浓度梯度,诱导HeLa细胞凋亡,利用荧光能量共振转移(fluorescence resonance energy transfer,FRET)成像系统进行实时监测,分析细胞对不同浓度化合物的毒性反应.结果表明,细胞在顺铂诱导下发生明显的起泡和皱缩,FRET比率值逐渐降低,在药物浓度梯度作用下,芯片每个通道内细胞呈现不同程度的凋亡.该方法实现了药物浓度梯度诱导细胞凋亡的实时监测和定量分析,为抗肿瘤药物评价和高通量药物筛选提供了新的手段. 相似文献
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针对车载无人机遥感系统中实时影像数据获取的问题,设计并实现了基于嵌入式平台的图像采集模块。以ARM微处理器和嵌入式Linux操作系统为主控核心,详细介绍了系统的整体设计架构及软硬件的实现。在完成成像设备驱动移植的基础上,基于V4L2编写数据采集程序,实现视频动态显示与图像的采集存储;基于LCD触摸屏和Qt/Embedded工具设计图像数据采集控制终端,实现拍摄控制与参数设置等功能。系统软硬件联调与实验结果表明:该系统可以通过控制终端控制成像设备完成图像采集任务,并能将所采集数据实时保存至存储设备中,实现了友好的人机交互,达到了预期效果。 相似文献
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《理化检验(化学分册)》2016,(2)
基于流动注射-光纤光谱仪联用技术研制了纺织品中游离和水解的甲醛含量测定的自动化分析系统。该系统包括萃取、显色反应、分光光度测定、数据采集与处理等4大模块。甲醛的质量浓度在0.025~3.00mg·L-1范围内与其吸光度呈线性关系,检出限(3s/k)为0.008mg·L-1。方法应用于纺织品样品的分析,测定结果与国标法测定值相符,加标回收率在94.4%~105%之间,测定值的相对标准偏差(n=7)在1.2%~1.9%之间。 相似文献
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石墨炉原子吸收光谱法间接测定蒸汽含水率 总被引:1,自引:0,他引:1
利用石墨炉子吸收光谱法测定蒸汽发生器循环水和蒸汽冷凝水中的铯则间接测定蒸汽含水率。蒸汽含水率等于冷凝水中铯的浓度除以循环水中铯的浓度。石墨炉原子吸收光谱可以准确测定0.1g/L至1mg/L浓度的铯,样品中可能存在的一些物质对测定没有干扰。本方法可以满足测定蒸汽含水率的要求,实现了数百份含水率样品的测试。 相似文献
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研制了一种微型嵌入式遥测系统,并利用此系统实现了电化学传感检测。遥测系统的输出电压范围为-0.5~0.5 V,分辨率<1 mV;电流检测范围为-1~1μA,最小分辨率为0.2 nA。此遥测系统是基于ADuCM360微处理器设计的,包括恒电位仪、电流检测模块和无线模块,尺寸大小为24 mm ×13 mm ×11 mm。利用LabVIEW开发上位机软件,用于数据存储和实时显示。为了验证该系统的精度和可靠性,对系统进行了电学性能测试。应用遥测系统检测不同浓度抗坏血酸溶液的电流响应,电极施加的工作电位为30 mV,在浓度范围50~300μmol/L 内,抗坏血酸电极的电流响应与其浓度呈现良好的线性关系,线性方程为I(nA)=2.98CAA(μmol/L)-137.39,线性相关系数R2=0.984。并以脑缺血模型为例,探索了仪器在活体动物研究中的适用性。结果表明,该系统可用于相关动物模型的研究。 相似文献
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为了实现对微弱神经递质信号的在体实时检测,设计并实现了一种无线电化学检测仪器。系统硬件以低功耗微控制器MSP430为主控制器,包括了微弱电流检测模块、波形产生模块以及数据收发模块,具有尺寸小(2.3 cm×1.8 cm×0.6 cm),功耗低的特点。基于u C/OS操作系统设计了系统的下位机程序,结合上位机软件实现了检测数据的实时显示与分析。针对神经递质的实际检测需求,系统集成了计时电流法与快速循环伏安法两种电化学检测分析方法。利用快速循环伏安法对不同浓度的多巴胺标准溶液进行了测试,在浓度范围5.0×10#7~7.0×10#5mol/L内,系统检测的响应电流与多巴胺浓度之间线性相关系数R=0.99。在此基础上,开展了大鼠在体多巴胺检测的实验,并成功检测到大鼠尾状壳核脑区的电诱发多巴胺释放信号。实验结果表明,此仪器具有检测灵敏度高的优点,能够实现对大脑内神经递质信号的定性及定量分析,在神经科学研究领域具有广阔的应用前景。 相似文献
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Uroš Grošelj Mojca Žorž Amalija Golobič Branko Stanovnik Jurij Svete 《Tetrahedron》2013,69(52):11092-11108
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives. 相似文献
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The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion. 相似文献
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N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%). 相似文献
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Shashikant U. Dighe Surya K. Samanta Shivalinga Kolle Sanjay Batra 《Tetrahedron》2017,73(17):2455-2467
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones. 相似文献
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In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates. 相似文献
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An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions. 相似文献
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Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described. 相似文献
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用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在. 相似文献
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An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction. 相似文献
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The Diels-Alder reactivity of 1,2-heteroborines (H4C4B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed. 相似文献