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101.
用酸性染料比色法测定魔芋总生物碱量,以盐酸金刚烷胺计,在2—10μg/mL范围内线性关系良好。设计正交试验选择总生物碱的最佳提取条件为:料液比1:12,乙醇浓度85%,索氏提取4h。  相似文献   
102.
采用红外图像系统对收集到的针式、激光、喷墨3种类型打印机的打印字迹样本各4份分别进行检验,依据3类打印机打印字迹的可见图像、化学图像和红外谱图,可以鉴别3种类型的打印机。可见图像鉴别可根据字迹的清晰程度及有无虚边等特点加以鉴别,化学图像鉴别可根据在不同的波程范围上化学图像清晰程度不同为依据。红外谱图部分主要是在相同的波程上吸收峰数目不同作为鉴别的主要依据。通过红外图像法鉴别打印机种类与其他方法相比,具有不破坏检材、检测范围广、检测速度快等优点。  相似文献   
103.
以火焰原子吸收光谱法测定重金属铬含量为宗旨,考察了雾化器流量、乙炔流量、氧化剂流量、燃烧头高度、基本改进剂等因素,结果发现,通过实验条件优化,校正系数从0.998265提高到0.999998,该方法能最大程度改善火焰原子吸收光谱法测定铬元素灵敏度低的问题,具有快速、准确、灵敏度高等优点,为与人类密切相关的食品、药品、化妆品、医疗器械等产品中重金属铬含量测定提供一定的参考。  相似文献   
104.
Eryi Hu  Yuan Hu 《Optik》2011,122(3):190-197
The nonlinear response of the experimental system and the saturation of fringe patterns can induce the fluctuating phase error in the projection grating phase-shifting profilometry. Two major factors of the fluctuating phase error are discussed by simulation. The fluctuating phase error caused by the nonlinear response of the system is four times the frequency of the fringe pattern when the conventional four-frame phase extracting algorithm is used. However, such error can be decreased by five-frame algorithm. On the other hand, the fluctuating phase error caused by the fringe saturation is five times the frequency of the fringe pattern by using conventional five-frame phase extracting algorithm. A novel phase recovering algorithm is used to decrease the phase error caused by the saturation. Furthermore, the applicability range of the proposed phase recovering algorithm is analyzed by simulation and experiments with different saturation degree of the fringe pattern and nonlinearity of the measurement system.  相似文献   
105.
We derive the motion equations and the structure equations of neutral and charged test particles, starting from the gravitational field equations. The method consists in the application of conservation laws to singular tensor densities, which represent regions of strong matter concentration. Moreover, a Hamiltonian formulation of the particle equations is given, in the form of implicit differential equations generated by Hamiltonian Morse families.  相似文献   
106.
The paper discusses recursive computation problems of the criterion functions of several least squares type parameter estimation methods for linear regression models, including the well-known recursive least squares (RLS) algorithm, the weighted RLS algorithm, the forgetting factor RLS algorithm and the finite-data-window RLS algorithm without or with a forgetting factor. The recursive computation formulas of the criterion functions are derived by using the recursive parameter estimation equations. The proposed recursive computation formulas can be extended to the estimation algorithms of the pseudo-linear regression models for equation error systems and output error systems. Finally, the simulation example is provided.  相似文献   
107.
Motivated by a general dilation theory for operator-valued measures, framings and bounded linear maps on operator algebras, we consider the dilation theory of the above objects with special structures. We show that every operator-valued system of imprimitivity has a dilation to a probability spectral system of imprimitivity acting on a Banach space. This completely generalizes a well-known result which states that every frame representation of a countable group on a Hilbert space is unitarily equivalent to a subrepresentation of the left regular representation of the group. We also prove that isometric group representation induced framings on a Banach space can be dilated to unconditional bases with the same structure for a larger Banach space. This extends several known results on the dilations of frames induced by unitary group representations on Hilbert spaces.  相似文献   
108.
We introduce new types of systems of generalized quasi-variational inequalities and we prove the existence of the solutions by using results of pair equilibrium existence for free abstract economies. We consider the fuzzy models and we also introduce the random free abstract economy and the random equilibrium pair. The existence of the solutions for the systems of quasi-variational inequalities comes as consequences of the existence of equilibrium pairs for the considered free abstract economies.  相似文献   
109.
《Applied Mathematical Modelling》2014,38(19-20):4574-4585
This paper presents a constructive approach to optimize the availability of a system through modeling the dependency of the components. Our goal is to minimize the system cost under the constraint that system availability must not be less than a given level. In particular, the components are dependent of each other. A function noted as the dependence function is introduced to model the dependency. It is demonstrated that, for a general form of the system cost, the dependence function guarantees a finite set of feasible solutions. An approach is then developed with the help of the dependence function to obtain the optimal solution. The resolution is illustrated by an interesting example, in which the system cost depends on the strength of the dependency. Our study reveals that the dependency is an essential and effective option to improve system reliability. Moreover, the modeling of dependency, i.e. the introduction of the dependence function is valuable for resolving the optimization problem.  相似文献   
110.
For arbitrary systems of two linear second-order ordinary differential equations, the symmetry Lie algebra is described in terms of invariant theory, resulting in eleven non-equivalent symmetry types. The result is compared with the group classification approach recently obtained by different authors.  相似文献   
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