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悬浮液进样——火焰原子光谱法测定蘑菇中的微量元素 总被引:1,自引:0,他引:1
用悬浮液技术处理样品,将样品烘干、粉碎、过筛,悬浮于琼脂深液中制成悬浮液。分别以Sr^ 2溶液和氯化钠溶液作为测定镁、钾的释放剂和消电离剂。以吸收法测定镁、锌,以发射法测定钾。对样品悬浮液的稳定时间、试液与空白溶液精度的一致性、干扰及线性范围进行了考察。测定结果的相对标准偏差小于2.3%,平均加标回收率为99.1%-101.9%。 相似文献
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本文介绍了利用激光束衍射效应形成的光斑,对大型机件进行精密平直度的测量,测量装置的读数值为 0.001 mm,测量相对误差为 1.4×10-6。 相似文献
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介绍了由作者研制的光谱范围从365至12000nm的高精度光电自动折射仪的测量原理、主要误差源和仪器组成。用该仪器对包括红外材料锗在内的多种样品进行了测量,在小于2600nm和大于2600nm的波长范围内分别获得了优于±3×10-6和±5×10-5的折射率测量精度。 相似文献
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目的:建立离子色谱法测量尿镁的方法。方法:采用Metrohm-883离子色谱检测人体新鲜尿液标本中镁的含量。使用2.0mmol/L浓硝酸为淋洗液,采用Metrosep C4-150/4.0阳性色谱柱电导检测。样本经离心、C18柱预处理、0.25μm滤过膜过滤后直接进样。结果:本法测量尿液中镁离子标准曲线的相关系数为0.999986,检出限为0.049mg/L,精密度高(RSD为0.624054%)。结论:与传统化学分析方法相比,离子色谱法准确、快速地测量尿镁;并同时测量了尿钠、尿钾、尿钙,此法适用于临床对尿结石患者进行尿液成石危险因素的代谢评估。 相似文献
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DXS-202型开方积算器特殊故障一例盐城市印染厂黄斌,张晓蓉开方积算器是孔板式流量计的主要组成部分,它起着对测量信号(0~10mA)进行开方和积算的作用,以保证流量测量的准确指示。我厂有一台上海产DXS-202型开方积算器,在使用中我们发现一起特殊... 相似文献
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国家环境标准样品在实验室质量控制与质量保证方面起着关键性的作用,但同时在新方法分析的验证方面也起着重要的步骤。主要是利用火焰原子吸收法与离子色谱法,对钾、钠、钙,镁离子的混合标样分析做了一个比对,认为用离子色谱法同样可以准确分析钾、钠、钙、镁离子。 相似文献
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介绍了以MCS-51单片机8031为核心的集中供热系统中各支路管线在线热平衡测试智能仪表的硬件和软件的组成,以平衡阀口径-压差-流量-曲线为参考,建立了不同压差状态下流量测试的数学模型,对十几个供热管线测试表明,与进口的超声波流量仪对比,最大测量偏差〈10%,测试条件宽松,适于野外作业。 相似文献
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介绍用微机和传感器技术,测量范围为-10 ̄5~+10 ̄5Pa的微压测量系统。实验及应用效果良好。只要选择相应的传感器就可以用于其它范围的微压测量。 相似文献
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In a recent paper, the Ritz method with simple algebraic polynomials as trial functions was used to obtain an eigenvalue equation for the free vibration of a class of homogeneous solids with cavities. The method presented is here extended to the study of a class of non-homogeneous solids, in which each solid is composed of a number of isotropic layers with different material properties. The Cartesian coordinate system is used to describe the geometry of the solid which is modelled by means of a segment bounded by the yz, zx and xy orthogonal coordinate planes and by two curved surfaces which are defined by fairly general polynomial expressions in the coordinates x, y and z. The surface representing the interface between two material layers in the solid is also described by a polynomial expression in the coordinates x, y and z. In order to demonstrate the accuracy of the approach, natural frequencies are given for both a two- and three-layered spherical shell and for a homogeneous hollow cylinder, as computed using the present approach, and are compared with those obtained using an exact solution. Results are then given for a number of two- and three-layered cylinders and, to demonstrate the versatility of the approach, natural frequencies are given for a five-layered cantilevered beam with a central circular hole as well as for a number of composite solids of more general shape. 相似文献
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V. P. Dragunov E. G. Kostsov 《Optoelectronics, Instrumentation and Data Processing》2009,45(3):234-242
Specific features of operation of one- and two-capacitor microelectromechanical converters (MEMC) of energy of mechanical microscopic vibrations into electric energy with a modulated electrode-gap magnitude and with allowance for the mutual influence of electrical and elastic forces are analyzed, and the characteristics of these two devices are compared. The main factors restricting the increase in MEMC power are demonstrated to be the effects of “collapsing” and the condition of conservation of positive rigidity of the system. Expressions for estimating the limiting MEMC parameters are derived. The possibility of electrical energy generation in the presence of “real“ sources of wide-spectrum microscopic vibrations is considered. 相似文献
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对某型卫星转播车方舱的装载要求进行分析,结果证明,必须对方舱舱体的质量进行严格的控制,在不影响整舱强度的条件下,采取各种方法,尽量将方舱质量减到最轻。本文从方舱的舱板、舱门及孔口和舱体拼装等几个方面,对可能采取的减轻质量的方法进行了分析,对方舱所用型材、拼装结构和涂胶量进行优化、减重分析和处理,结果可满足对整车的功能性要求和质量限制。 相似文献
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通过分析膨胀套在实际使用产生滑移受阻现象、卡死现象原因的实质,并在分析产生问题原因的基础上提出了改进措施即:增加导向机构。 相似文献
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Modern methods of implementation of the rule of positive gradient of mechanical properties are considered; this rule was formulated by I.V. Kragelskii and its application serves to minimize the friction and wear of solids. The given methods include the application of coatings with the method of finishing antifricton abrasion-free treatment; application of new metal-cladding lubricating materials; and creation of a nanostructural state of the surface iron nitride layer by nitriding steel with a positive gradient of hardness normal to the surface. 相似文献
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介绍了挖掘机液压系统的功率参数与流量控制机理,从液压系统的功率角度分析了液压挖掘机的功率控制方式,从挖掘机负流量液压系统与正流量液压系统的工作原理方面分析了其控制性能及优缺点,并总结了挖掘机负流量液压系统与正流量液压系统的技术价值、应用场合及改善方向。 相似文献