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The 138La–138Ce isotope system has been regarded as a useful radiogenic tracer for geochronology studies. Compared to the commonly-used CeO+ technique, the measurement of Ce isotope ratios as Ce+ is more straightforward and more advantageous, but it is challenging due to the severe isobaric interference of 138Ba on 138Ce and large variations in relative abundances of all Ce isotopes. In this study, a novel method has been developed for high-precision measurement of Ce isotope ratios by thermal ionization mass spectrometry (TIMS) as Ce+. A newly-developed film porous ion emitter (FPIE) was used to enhance the ionization of Ce as Ce+ ions. The employment of TaF5 as an activator significantly suppressed the Ba+ isobaric interference signal. 140Ce was proposed to be an alternative reference Ce isotope as there is no isobaric interference on 140Ce and complicated peak tailing correction can be avoided. The combinations of diverse amplifiers (1010 Ω, 1011 Ω, 1012 Ω and 1013 Ω) were used for the measurement of Ce isotope ratios as Ce+ and 137Ba was monitored simultaneously on a 1013 Ω amplifier for 138Ba interference correction. The reproducibility of Ce isotope ratios obtained was ca. 10-fold better than the previously published Ce+ results and even comparable with that obtained using the more laborious CeO+ techniques. This method was further applied for the analysis of reference rock samples and uranium ores of world-wide origin. The analytical results demonstrated that Ce isotope ratios could be a promising signature for the nuclear forensic investigation to identify the source of unknown nuclear materials.

In the future, electronic system is developing towards higher integration density, higher performance and higher working frequency. Traditional integration and packaging technology will not reach the integration requirement of the novel RF microsystems. The integration technology of RF microsystems is the main method of realizing the requirement of the future electronic system. In this paper, the technology connotation and system of the RF microsystems integration technology is reviewed. The technology challenge and development opportunity is predicted. The strategic thinking of the research on the integration technology of RF microsystems is illustrated.

There is an increasingly critical demand on the angular stability of double crystal monochromator (DCM). This work focuses on a method to measure angular vibration directly at the DCM crystals using a dual-frequency interferometer. This method was applied to the off-line test of a newly developed cryocooled DCM at Shanghai Syn-chrotron Radiation Facility (SSRF), which can obtain a resolution of 8 nrad. The DCM was then tested on the X-ray Test Line. Both off-line and on-line results were referenced for DCM structure optimizations. In this paper, the DCM angular stability measuring method is presented, and detailed information of the results are shown., Proceedings of the Mechanical Eng.~Design of Synchrotron Radiation Equipment and Instrumentation, MEDSI2018, Paris, France

SAE ARP 4754 has been widely applied in the process of airworthiness certification in highly-integrated or complex electronic system of civil aircraft since 1996. But with the complexity of integration and function increasing in the system design process, the standard can not fully meets the state-of-art technical requirements of designer and engineers. Hence the new version SAE ARP 4754A arises in December 2010, which mainly revises the part of development assurance level allocation, provids a methodology to assign the correct development assurance levels. In order to better understand and apply ARP 4754A in the field of airworthiness and safety, this paper will compare SAE ARP 4754A and 4754 on aspects of applicable scope, development process and integral process, etc, expecting to make clear the differences and carry on analysis about the differences to show the significances of the changes for civil aircraft airworthiness and safety

Objective: to explore the possible mechanism of sub-health in women from the perspective of traditional Chinese medicine, and to explore the mechanism of treating sub-health status in women at different physiological stages by using professor xia guicheng, a master of traditional Chinese medicine, his theory of tonifying kidney and regulating menstruation. Methods: through the sharing and interpretation of clinical cases of female sub-health, the occurrence mechanism, therapeutic effect and action mechanism were analyzed. Conclusion: the method of tonifying kidney and regulating menstruation by professor xia guicheng, can effectively solve the sub-health status of women.