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51.
We provide a new expression of the quantum Fisher information (QFI) for a general system. Utilizing this expression, the QFI for a non-full rank density matrix is only determined by its support. This expression can bring convenience for an infinite-dimensional density matrix with a finite support. Besides, a matrix representation of the QFI is also given. 相似文献
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Stanley Rasberry 《Accreditation and quality assurance》2001,6(6):252-256
Traceability implies comparison of the results of measurements, or comparison to national or international measurement standards.
One of several approaches that have been used in chemistry to provide for such comparisons is distribution of proficiency
evaluation materials which have been measured by a reference laboratory. A newer approach is based on receipt and measurement
at a reference laboratory of materials that have been produced and analyzed by other laboratories. Traceability concepts and
approaches to realization will be described together with discussion of the relative merits of various approaches. Extension
into metrological fields other than chemistry will also be explored.
Received: 14 November 2000 Accepted: 11 December 2000 相似文献
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Emmanuel Nolot Yann Mazel Jean-Paul Barnes Chiara Sabbione Gabriele Navarro Agnes Tempez Sébastien Legendre 《Surface and interface analysis : SIA》2020,52(12):895-899
We demonstrate the potential of using plasma profiling time-of-flight mass spectrometry (PP-TOFMS) to accelerate process developments for phase-change random access memory (PCRAM) applications, which require advanced materials with composition-driven properties. We assess the performances of PP-TOFMS for the chemical depth-profiling of GeSbTe phase change materials, first after deposition steps to investigate the top surface layer and the incorporation of silicon into the amorphous matrix, then after the thermal annealing step to refine in situ capping strategies, and finally in close loop with etching process steps. Comparison of reference-free semiquantitative PP-TOFMS analysis based on ion beam ratio with Rutherford backscattering spectrometry shows remarkable agreement (~10% relative). PP-TOFMS proves to be a fast screening tool, which allows process monitoring and selection of samples that indeed need more complex analysis. 相似文献
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Accuracy and sensitivity of a hole drilling and digital speckle pattern interferometry combined technique to measure residual stresses 总被引:4,自引:2,他引:2
This paper reports on the accuracy and sensitivity of digital speckle pattern interferometry (DSPI) when it is combined with the hole drilling technique for measuring residual stresses. The in-plane displacement field generated by the introduction of a small hole is determined using an automated data analysis approach. This method is based on the calculation of the optical phase distribution through a phase-shifting method and the application of a robust iterative phase unwrapping algorithm. It is experimentally demonstrated that residual stresses can be measured with a relative uncertainty of 7.5%. It is also shown that the minimum value of residual stress that can be determined with the DSPI and hole drilling combined technique is about 10% of the yield stress of the material. 相似文献
59.
双成象单元扫描隧道显微镜与原子尺纳米计量技术 总被引:3,自引:3,他引:0
研制了双成象单元扫描隧道显微镜(STM),可同时对参考样品的原子晶格和被测样品扫描成象.计数原子晶格的数目,即可精确测定被测样品图象的尺度,以原子尺方式实现严格的纳米计量.本文介绍双成象单元的STM的原理和仪器系统,讨论原子尺纳米计量的可行性,给出被测样品图象的纳米计量结果. 相似文献
60.
Paul De Bièvre Robert Kaarls H. Steffen Peiser Stanley D. Rasberry William P. Reed 《Accreditation and quality assurance》1996,1(1):3-13
By the definition of the mole as a base unit for amount-of-substance measures within the International System of Units (SI),
chemists can make chemical measurements in full compliance with established metrological principles. Since the mole requires
exact knowledge of the chemical entity, which is often neither available nor of practical relevance to the purpose of the
measurement, the SI units of mass or length (for volume) are unavoidable in the expression of results of many chemical measurements.
Science, technology, and trade depend upon a huge and ever increasing number and variety of chemical determinations to quantify
material composition and quality. Thus, international harmonization in the assessments of processes, procedures, and results
is highly desirable and clearly cost effective. The authors, with relevant experience and responsibilities in Europe and America,
have found some consensus in the interpretation of the metrological principles for chemical measurements, but believe open
discussion should precede wide implementation by chemical communities. In fostering this dialogue, this paper shows, for instance,
that more precise interpretation of the definitions for "traceability," "calibration," and "validation" is needed for present-day
chemical measurements. Problems that face scientists in making measurements do not all vanish just by adherence to the SI.
However, such compliance can improve communication among chemists and metrologists.
Received: 30 June 1995 Accepted: 30 June 1995 相似文献