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1.
本文合成了一种新的有机锡化合物,通过熔点测定、红外光谱、核磁共振谱、元素分析、锡含量测定等手段对其结构进行了表征。 相似文献
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离子交换树脂相光度法测定钯的研究 总被引:5,自引:0,他引:5
根据钯(Ⅱ)与1-(5-溴-2-吡啶偶氮)-2-萘酚-6-磺酸(5-Br-PAN-S)形成稳定络合物这一物质,利用阴离子交换树脂为吸附载体,建立了离子交换树脂相光度法测定钯的新方法。以最大吸收波长690nm为测定波长,800nm为参比波长,用双波长法进行测定,灵敏度高,选择性,重现性好,钯量在0 ̄20μg范围内服从比尔定律。方法用于合成水样及催化剂中钯的测定,结果满意。 相似文献
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采用5-Br-PADAP-OP显色体系测定铜,考查了测定条件。以正三辛胺萃取分离干扰高子,考查了萃取分离条中。人工合成样品回收率100.8%,铝合金标样测定误差<-2.2%,人发分析结果的相对标准偏差<4.0%。 相似文献
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本文用X射线荧光光谱-互标法对Ba-Ti-Sr-Y-Si-Mn体系中各成份含量进行了测定,证明了互标法是一种精度高、准确度好地分析方法。 相似文献
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本文采用Hypersil-ODS2(4.6mm×250mm,5μm)色谱柱,乙腈-水(70∶30)流动相,242nm测定波长,建立了测定2-苯基4-对甲苯基-1,5-苯并硫氮杂(艹)/(卓)-α-(丁二酰亚胺基)-β-内酰胺高效液相色谱法.该法线性范围为0-0.1mg/mL,回归方程A=2.11×108C-3.10×105,相关系数r=0.9995,相对标准偏差为0.24%(C=0.06mg/mL,n=5),检出限为0.05μg/mL.平均回收率在97.1%-102.4%之间.该法重现性好、灵敏度高、简单、快速、准确. 相似文献
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应用高效液相色谱外标定量法对2-对甲氧基苯基-4-苯基-1,5-苯并硫氮杂(艹卓)-α-(丁二酰亚胺基)-β-内酰胺进行了测定.采用Hypersil-ODS2(4.6mm×250mm,5μm)柱,乙腈与水按70∶30(V/V)组成流动相,测定波长为242nm,该方法线性范围为0-0.1mg/mL,回归方程A=1.91×108C-3.82×105,相关系数r=0.9994,相对标准偏差为0.72%,检出限为0.05μg/mL,平均回收率在98.4%-101.8%之间.该法重现性好、灵敏度高、简单、快速. 相似文献
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氢化物发生-ICP-AES法测定活性炭中的砷 总被引:2,自引:0,他引:2
本文介绍了一种ICP-AAES与氢化物发生法联用测定活性炭产品中总砷含量的方法,并对样品的炭化条件、仪器工作参数、基体的干扰等进行了讨论,方法的相对标准偏差〈3%(n=9),检出限为1.8ng/mL,加标回收率在95%以上,为准确测定活性炭系列产品中总砷含量提供了一种简便、快速的方法。 相似文献
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本文提出了用ICP-AES法直接测定高纯氧化钐中痕量杂质铜、铁、钙和镍的方法。用正交实验法研究了影响测定的主要因素,选择了铜、铁、钙和镍同时测定的折衷条件。讨论了基体浓度的影响。 相似文献
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ICP—AES法测定出口镁砂 总被引:3,自引:1,他引:2
应用ICP-AES法对出口镁砂中硅、钙、铁、铝、钛等氧化物含量进行测定。文中对其测试方法、条件进行探讨;辅以灼烧减量的测定,从中可以求出高含量的氧化镁。方法准确,快速,优于化学法。 相似文献
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研究了初中伏安法测电阻的电路选择方法和数据处理方法,完善了电路选择方法,拓展和规范了现行教科书的数据处理方法;依据标配电表和待测电阻参量给出了运用电路选择方法的可行结果,结合实测数据给出了运用数据处理方法的合理结果,提出了相应的教学建议. 相似文献
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Identification of nonlinear multi-degree-of freedom structures based on Hilbert transformation 总被引:1,自引:0,他引:1
The modeling method and identified method adapted to multi-degree-of-freedom structures with strucrural nonlinearities are established. The component mode synthesis method is used to establish the nonlinear governing equations by extending the connected relationships. Based on the modeling method, the Hilbert transform method is applied to identify the nonlinear stiffness of multi-degree-of-freedom structures. Nonlinear analysis and identification of a typical folding wing configuration with three freeplay hinges are investigated. The nonlinear governing equation is established based on present methods and the computing results of different stiffness are checked by finite element programming. In order to illustrate the influence of the nonlinearities, the frequency response characteristics of the structure are analyzed and Hilbert transform is performed. The Hilbert transform identification method is utilized to identify the nonlinear stiffness of nonlinear hinges in the time domain and several parametric studies are performed. In addition, the comparison of response is made to illustrate the feasibility of the methods. The results show that the extending component mode synthesis method in the present work can be used to establish the governing equation with structural nonlinearities. Based on the modeling method, the Hilbert transform identified method can be extended to multi-degree-of-freedom structures accurately. 相似文献
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The complex variable reproducing kernel particle method for two-dimensional elastodynamics
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On the basis of the reproducing kernel particle method (RKPM), a new meshless method, which is called the complex variable reproducing kernel particle method (CVRKPM), for two-dimensional elastodynamics is presented in this paper. The advantages of the CVRKPM are that the correction function of a two-dimensional problem is formed with one-dimensional basis function when the shape function is obtained. The Galerkin weak form is employed to obtain the discretised system equations, and implicit time integration method, which is the Newmark method, is used for time history analysis. And the penalty method is employed to apply the essential boundary conditions. Then the corresponding formulae of the CVRKPM for two-dimensional elastodynamics are obtained. Three numerical examples of two-dimensional elastodynamics are presented, and the CVRKPM results are compared with the ones of the RKPM and analytical solutions. It is evident that the numerical results of the CVRKPM are in excellent agreement with the analytical solution, and that the CVRKPM has greater precision than the RKPM. 相似文献
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介绍了克劳修斯方法对可逆和不可逆过程(循环)的处理,提出了处理不可逆过程的方法,论证了处理方法与克劳修斯方程的一致性,论述了克劳修斯方法的实质和意义;简单介绍了熵的另一个导出方法,比较了两种方法对绝热过程的处理,指出克劳修斯方法存在一个假设条件. 相似文献
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An improved boundary element-free method (IBEFM) for two-dimensional potential problems 总被引:1,自引:0,他引:1
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The interpolating moving least-squares (IMLS) method is discussed
first in this paper. And the formulae of the IMLS method obtained by
Lancaster are revised. Then on the basis of the boundary
element-free method (BEFM), combining the boundary integral equation
(BIE) method with the IMLS method, the improved boundary
element-free method (IBEFM) for two-dimensional potential problems
is presented, and the corresponding formulae of the IBEFM are
obtained. In the BEFM, boundary conditions are applied directly, but
the shape function in the MLS does not satisfy the property of
the Kronecker δ function. This is a problem of the BEFM, and
must be solved theoretically. In the IMLS method, when the shape function
satisfies the property of the Kronecker δ function, then the
boundary conditions, in the meshless method based on the IMLS
method, can be applied directly. Then the IBEFM, based on the IMLS
method, is a direct meshless boundary integral equation method in
which the basic unknown quantity is the real solution of the nodal
variables, and the boundary conditions can be applied directly and
easily, thus it gives a greater computational precision. Some
numerical examples are presented to demonstrate the method. 相似文献
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对几种模拟随机湍流相位屏的方法进行了总结,利用结构函数对每种方法进行了分析,并从Zernike多项式分解的思路和激光大气传输的角度,通过焦斑扩展和焦斑质心漂移对几种方法进行了完整比较,最后对湍流低频倾斜信息的补偿方式进行了探讨。通过分析发现:傅里叶变换(FFT)法模拟的相屏体现的湍流高频信息较充分,但低频信息不足;Zernike法模拟的相屏体现的湍流低频信息较充分,但高频信息不足。随着采用的Zernike多项式阶数的增加,其体现的高频信息会得到改善,但这些高频信息主要集中在圆域的边缘区域。分形法模拟的相屏体现的湍流高低频信息均较好。针对焦斑扩展和焦斑质心漂移,除分形法外,其他算法均存在不同缺陷。采用FFT法与Zernike多项式展开法相结合的方式或FFT法与湍流自相似理论相结合的方式模拟大气湍流随机相屏,也不失为一种较有效的方式,但从激光大气传输的角度来说,采用分形法模拟湍流随机相屏最好。 相似文献
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光纤光栅传感信号解调技术研究进展 总被引:1,自引:0,他引:1
光纤光栅传感器是一种新型传感器,有着非常广泛的应用前景。限制光纤光栅传感器大量实际应用的主要障碍是传感信号解调,因而,光纤光栅传感信号解调是光纤光栅传感器应用的关键技术之一。本文对现有已报道的光纤光栅传感信号的解调方法进行综述,并归类为:边缘滤波法、匹配滤波法、可调谐滤波法、光源波长可调谐扫描法、射频探测法、光栅啁啾法、CCD分光仪法、干涉法。对各种方法的原理及相关改进方法进行了阐述,并对其优缺点做了比较分析,最后,对光纤光栅传感信号的解调技术发展进行了展望。 相似文献
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针对传统谱元法在每个单元内只能存在单一均匀介质,应用在复杂非均匀介质的波传播模拟中可能造成极大计算规模的问题,发展了多网格谱元法。该方法在谱元法单元内引入独立的辅助网格,用于精细描述单元内的介质和外力分布变化,在较稀疏的主网格上进行波场的求解。基于声波和弹性波方程推导了多网格谱元法公式,并对几种典型模型进行了波场的数值模拟。与传统谱元法的对比结果表明,此算法在复杂非均匀介质的弹性波传播模拟中可以利用较少的网格点数达到不低于传统算法的精度。此外,实现了并行化的多网格谱元法,获得了较好的并行效率。 相似文献