Conjugate Heat Transfer Analysis and Heat Dissipation Design of Nucleic Acid Detector Instrument

Temperature affects both the stability of nucleic acid detectors and efficiency of DNA amplification. In this study, temperature and flow inside a nucleic acid detector were simulated and the results were used to design vents for the instrument casing. A test platform was constructed to collect experimental temperature data that were used for simulation validation. The experimental and simulation results showed that the temperature error was less than ±3 K. A total of two heat-dissipation schemes were designed based on the simulation and a new instrument casing was fabricated based on the scheme with the best results. Nucleic acid amplification was performed continuously for 120 min using a prototype with the new casing. The temperatures of the monitoring points were stable and the maximum temperature measured only 307.76 K (34.61 °C). Therefore, waste heat was effectively eliminated, which ensured safety of the electronic components and stability of the nucleic acid detection process

High Mg effective incorporation in Al-rich AlxGa1 (-) N-x by periodic repetition of ultimate V/III ratio conditions

'973' program [2012CB619301, 2011CB925600]; '863' program [201144034111, 2014AA032608]; National Natural Science Foundation of China [61106008, 60827004, 90921002]; Natural Science Foundations of Fujian Province [2010 J01343, 2012 J01024]; fundamental research funds for the central universities [2011121042]According to first principles calculations, the solubility of Mg as a substitute for Ga or Al in AlxGa1- xN bulk is limited by large, positive formation enthalpies. In contrast to the bulk case, the formation enthalpies become negative on AIxGa(1 - x)N surface. In addition, the N-rich growth atmosphere can also be favorable to Mg incorporation on the surface by changing the chemical potentials. On the basis of these special features, we proposed a modified surface engineering technique that applies periodical interruptions under an ultimate V/III ratio condition (extremely N-rich), to enhance Mg effective incorporation. By optimizing the interruption conditions (2 nm interruption interval with 2 s interruption time), the enhancement ratio can be up to about 5 in the Al0.99Ga0.01N epilayer

High Mg effective incorporation in Al-rich AlxGa1-xN by periodic repetition of ultimate V/III ratio conditions

According to first-principles calculations, the solubility of Mg as a substitute for Ga or Al in AlxGa1-XN bulk is limited by large, positive formation enthalpies. In contrast to the bulk case, the formation enthalpies become negative on ALxGa1-xN surface. In addition, the N-rich growth atmosphere can also be favorable to Mg incorporation on the surface by changing the chemical potentials. On the basis of these special features, we proposed a modified surface engineering technique that applies periodical interruptions under an ultimate V/III ratio condition (extremely N-rich), to enhance Mg effective incorporation. By optimizing the interruption conditions (2 nm interruption interval with 2 s interruption time), the enhancement ratio can be up to about 5 in the Al0.99Ga0.01N epilayer. ? 2014 Zheng et al