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In order to explore the differences in the aroma quality of different white-fleshed peach cultivars, an electronic nose and headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS) were used to analyze the volatile components of eight cultivars of white-fleshed peach including Baiyintao (BYT), Longmi 5 (LM5H), Xinchuanzhongdao (XCZD), Qiutong (QT), Xindajiubao (XDJB), Yihongmi (YHM), Yihongshuimi (YHSM) and Okayama (GSB). Relative odor activity value (ROAV) and variable importance in projection (VIP) were used to analyze the contribution of each volatile component to the overall aroma of white-fleshed peaches. In the electronic nose radar fingerprint, the W1W, W5S, W1S and W2W sensors showed different responses to the eight cultivars. Principal component analysis (PCA) demonstrated differences in the overall aroma of white-fleshed peach cultivars. In total, 49, 46, 46, 47, 49, 47, 47, 53 volatile compounds were identified in BYT, LM5H, XCZD, QT, XDJB, YHM, YHSM, and GSB by HS-SPME-GC-MS, respectively, the major ones being aldehydes, alcohols, lactones and esters. 2-Hexenal, hexanal, trans-2-hexenal and trans-2-hexen-1-ol, contributing to grass aroma; linalool, contributing to floral aroma; and n-hexanol, responsible for fruity aroma, were identified as key aroma compounds due to their ROAV ≥ 1 and VIP > 1. Variations in their concentrations caused differences in the key aroma of the eight white-fleshed peach cultivars.

The interconnecting solder is a key control factor for the reliability of electronic power packaging because it highly affects the junction temperature of insulated-gate bipolar transistor (IGBT) modules and is prone to plasticity, creep, and other failure behaviors under temperature-change environments. In this paper, the interconnecting performance and fatigue life of five different kinds of solders such as SAC305, sintered silver, Au80Sn20, sintered copper, and pure In under direct current (DC), power cycle, and electro-thermal coupling complex environments were studied based on electro-thermal multi-physical field coupling finite element simulation method, respectively. Results show that the sintered silver owns the most outstanding thermal reliability and the DC operating junction temperature of the IGBT module after utilizing sintered silver solder is only 90.2 °C, which is nearly 15 °C lower than that of the IGBT module utilizing SAC305 solder. Furthermore, in the power cycle reliability test, the fatigue life of Au80Sn20 solder reaches a maximum of 3.26 × 107 cycles while the life of indium presents only 5.85 × 103 cycles, a difference of nearly four orders of magnitude. Finally, under the complex environment of electro-thermal coupling, the fatigue life of Au80Sn20 solder is also the largest at 1.9 × 106 cycles, while the smallest life of solder becomes SAC305 solder at 4.44 × 102 cycles. The results of this paper can provide a theoretical basis for solder selection and life prediction of the IGBT module, which is of great significance in improving the reliability of power electronic packaging. [ABSTRACT FROM AUTHOR]

Using a gel-overlay technique of biotinylated calmodulin (CaM), we showed that maize cytosolic Hsp70 protein could bind to CaM in the presence of 1 mM CaCl2. The purified maize cytosolic Hsp70 inhibited the activity of CaM-dependent NADK in a concentrationdependent manner. A synthetic peptide, which possesses the 21 amino acid sequence, PRALRRLRTACERAKRTLSST, at positions 261–281 in maize cytosolic Hsp70, could associate with CaM in the presence of 1 mM calcium. The synthetic peptide inhibited CaM-dependent NADK activity and PDE activity. This indicates that the 21-amino acid sequence at positions 261–281 is the CaM-binding site. The binding of CaM to Hsp70 inhibited the ATPase activity of Hsp70. The possible regulator function of Hsp70 in cell signaling events in response to heat stress is discussed. [ABSTRACT FROM AUTHOR]