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71.
72.
氯胺酮在临床上是一种高效麻醉剂,但近年来被滥用于各种娱乐场所,因此,建立一种快速、准确的氯胺酮检测方法的重要性日益凸显.对于现有的各种检测方法,都需要相应的样品前处理过程,增加了检测时间和检测复杂度,最后的检测结果一定程度上和样品前处理有着密切关系.根据现有技术的不足,使用超声雾化装置利用电子的高频振荡对样品进行雾化处理,将液体样品转化为水雾状,经过快速气相色谱分离,利用声表面波传感器的响应来检测物质.经过标准样品的检测,线性关系良好,相关系数R2在0.9481以上,检出限为0.1 μg/mL,从样品处理到得到检测结果可在60 s内完成.本系统样品前处理简单,可在1 min内快速准确检测氯胺酮.通过标准溶液的实验,验证了本系统的可行性、可靠性和检测下限. 相似文献
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Conversion factors from counts to chemical ratios for the EURITRACK tagged neutron inspection system
W. El KanawatiB. Perot C. CarascoC. Eleon V. ValkovicD. Sudac J. Obhodas 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,654(1):621-629
The EURopean Illicit TRAfficking Countermeasures Kit (EURITRACK) uses 14 MeV neutrons produced by the 3H(d,n)4H fusion reaction to detect explosives and narcotics in cargo containers. Reactions induced by fast neutrons produce gamma rays, which are detected in coincidence with the associated alpha particle to determine the neutron direction. In addition, the neutron path length is obtained from a time-of-flight measurement, thus allowing the origin of the gamma rays inside the container to be determined. Information concerning the chemical composition of the target material is obtained from the analysis of the energy spectrum. The carbon, oxygen, and nitrogen relative count contributions must be converted to chemical proportions to distinguish illicit and benign organic materials. An extensive set of conversion factors based on Monte Carlo numerical simulations has been calculated, taking into account neutron slowing down and photon attenuation in the cargo materials. An experimental validation of the method is presented by comparing the measured chemical fractions of known materials, in the form of bare samples or hidden in a cargo container, to their real chemical composition. Examples of application to real cargo containers are also reported, as well as simulated data with explosives and illicit drugs. 相似文献
75.
I. Dantone L. Fabbri E. Foschi C. Guandalini G. Laurenti I. Lax G. Levi L. Quadrani Ca. Sbarra Cr. Sbarra M. Villa A. Zoccoli M. Zuffa 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,630(1):384
The silicon photomultipliers (SiPM) are adopted in various physical applications, from medical physics to astrophysics, for their advantages in terms of cost and weight with respect to traditional photo detectors. Their low bias voltage supply (about 30 V), hardiness and resistance to magnetic field are ideal characteristics for space application. In the frame of INFN-Irst collaboration, some of them have been developed and produced at FBK (Trento-Italy), and have been characterized in the INFN laboratories of Bologna (DaSiPM2 collaboration).The SiPM can be used in conjunction with fibres and counters in high energy physics experiments. To exploit the SiPM time resolution, a fast amplifier has been studied. The SiPM gain depends critically on temperature and a thermal stabilization is also necessary. The use of a thermoelectric cooler module based on a Peltier cell has been investigated, and the results are shown. 相似文献
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Computation of approximate optimal policies in a partially observed inventory model with rain checks
Alain Bensoussan Metin Cakanyildirim Suresh P. Sethi Ruixia ShiAuthor vitae 《Automatica》2011,(8):1589-1604
This paper proposes a new methodology to solve partially observed inventory problems. Generally, these problems have infinite-dimensional states that are conditional distributions of the inventory level. Our methodology involves linearizing the state transitions via unnormalized probabilities. It then uses an appropriate functional basis to represent the state. Considering the speed and stability of computations, we choose truncated Chebyshev polynomials as the basis. We use Fast Fourier Transforms along with an appropriate discretization of inventory levels to speed up the computations. These main ideas are blended to obtain an iterative algorithm to solve a partially observed inventory model with rain checks. In this model, the inventory manager (IM) does not know the inventory level when it is positive. Otherwise, the IM fully observes it. This model provides a context to illustrate our methodology, which applies to other such models. Although this model has been studied mathematically in the literature, the use of our algorithm provides a numerical approximation of the optimal order quantities. These are compared to the orders released under a base mean-stock policy, where the IM replaces the unobserved inventory level with its mean and applies the well-known base stock policy. We show numerically that the optimal order quantity is very close to the base mean-stock order quantity, when the variance of the inventory distribution is small. When the mean of the inventory distribution is large, the optimal order quantity is more than the base mean-stock quantity, and it is the other way around when the mean is small or negative. These insights are explained via uncertainty and information effects and their interplay. We expect this interplay to show up in other partially observed inventory models. 相似文献
78.
基于快速区域标签运算的目标跟踪算法 总被引:1,自引:1,他引:0
应用于目标跟踪中的快速标签算法,以二值化后的图像中不多于254个连通区域为条件,通过对所有目标的目标特征统计,及与真实目标的特征匹配,实现系统的实时、准确的目标跟踪。 相似文献
79.
针对阳泉煤业集团南庄煤矿8836运输巷局部超高,威胁安全生产的问题,实测了3个充填区域,设计了顶部柔膜袋快速充填方案,并进行了现场试验。结果表明:高水充填材料具备速凝早强特性,2 h强度1.25 MPa,28 d强度3.98 MPa,材料消耗约305 kg/m^3;效果考察表明,在工作面超前区,充填体下方单体柱受力均匀、明显,充填体接顶充分,工作面后方充填体垮落效果良好,未形成悬顶。 相似文献
80.
The TaqMan real-time PCR has the highest potential for automation, therefore representing the currently most suitable method for screening, allowing the detection of fraudulent or unintentional mislabeling of species. This work describes the development of a real-time polymerase chain reaction (RT-PCR) system for the detection and identification of common octopus (Octopus vulgaris) and main substitute species (Eledone cirrhosa and Dosidicus gigas). This technique is notable for the combination of simplicity, speed, sensitivity and specificity in an homogeneous assay. 相似文献