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[en] Heat leakage is an important parameter to reflect heat insulated performance of cryogenic vessel. According to the current standard requirements, it needs to measure the daily evaporation rate to indicate heat leakage. The test needs-over 24h after cryogenic vessel in heat equilibrium as standard required, therefore test efficiency is poor and new efficient method is required to cut test time. First of all, the volume of instantaneous evaporated gas and heat leakage are calculated by the current standard corresponding to the maximum allowable daily evaporation rate of cryogenic vessel. Depending on the relationship between real daily evaporation rate and maximum allowable daily evaporation rate of cryogenic vessel, we designed a new test method based on the pressure changes over time in cryogenic vessel to determine whether its heat insulated performance meets requirements or not. Secondly, the heat transfer process was analyzed in measurement of cryogenic vessel, and the heat transfer equations of whole system were established. Finally, the test was completed in four hours; meanwhile the heat leakage and daily evaporation rate of cryogenic vessel are calculated basing on test data
[en] In this paper, we present an improved high-frequency equivalent circuit for SiGe heterojunction bipolar transistors (HBTs) with a CBE layout, where we consider the distributed effects along the base region. The actual device structure is divided into three parts: a link base region under a spacer oxide, an intrinsic transistor region under the emitter window, and an extrinsic base region. Each region is considered as a two-port network, and is composed of a distributed resistance and capacitance. We solve the admittance parameters by solving the transmission-line equation. Then, we obtain the small-signal equivalent circuit depending on the reasonable approximations. Unlike previous compact models, in our proposed model, we introduce an additional internal base node, and the intrinsic base resistance is shifted into this internal base node, which can theoretically explain the anomalous change in the intrinsic bias-dependent collector resistance in the conventional compact model. (paper)
[en] The conformal mapping of an electric field has been employed to develop an accurate parasitic capacitance model for nanoscale fin field-effect transistor (FinFET) device. Firstly, the structure of the dual-layer spacers and the gate parasitic capacitors are thoroughly analyzed. Then, the Cartesian coordinate is transferred into the elliptic coordinate and the equivalent fringe capacitance model can be built-up by some arithmetical operations. In order to validate our proposed model, the comparison of statistical analysis between the proposed calculation and the 3D-TCAD simulation has been carried out, and several different material combinations of the dual- k structure have been considered. The results show that the proposed analytical model can accurately calculate the fringe capacitance of the FinFET device with dual- k spacers. (paper)
[en] The impact of negative bias temperature instability (NBTI) can be ascribed to three mutually uncorrelated factors, including hole trapping by pre-existing traps ( in gate insulator, generated traps ( in bulk insulator, and interface trap generation (. In this paper, we have experimentally investigated the NBTI characteristic for a 40-nm complementary metal–oxide semiconductor (CMOS) process. The power-law time dependence, temperature activation, and field acceleration have also been explored based on the physical reaction–diffusion model. Moreover, the end-of-life of stressed device dependent on the variation of stress field and temperature have been evaluated. With the consideration of locking effect, the recovery characteristics have been modelled and discussed. (paper)
[en] Goatpox, caused by goatpox virus (GTPV), is an acute feverish and contagious disease in goats often associated with high morbidity and high mortality. To resolve potential safety risks and vaccination side effects of existing live attenuated goatpox vaccine (AV41), two Semliki forest virus (SFV) replicon-based bicistronic expression DNA vaccines (pCSm-AAL and pCSm-BAA) which encode GTPV structural proteins corresponding to the Vaccinia virus proteins A27, L1, A33, and B5, respectively, were constructed. Then, theirs ability to induce humoral and cellular response in mice and goats, and protect goats against virulent virus challenge were evaluated. The results showed that, vaccination with pCSm-AAL and pCSm-BAA in combination could elicit strong humoral and cellular responses in mice and goats, provide partial protection against viral challenge in goats, and reduce disease symptoms. Additionally, priming vaccination with the above-mentioned DNA vaccines could significantly reduce the goats' side reactions from boosting vaccinations with current live vaccine (AV41), which include skin lesions at the inoculation site and fevers. Data obtained in this study could not only facilitate improvement of the current goatpox vaccination strategy, but also provide valuable guidance to suitable candidates for evaluation and development of orthopoxvirus vaccines.