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Gears serve as vital elements in high-efficiency mechanical transmissions, playing a pivotal role in vehicles. Employing gear modification has the capacity to significantly enhance the dynamic properties of the Planetary Gear Transmission (PGT) systems. In this study, the investigation has been directed toward a three-stage PGT model system with a comprehensive consideration of various vibration-related factors that affect the dynamic behavior of the system. These factors are encompassed by Time Varying Mesh Stiffness (TVMS), torsion and bending forces experienced by connecting shafts, dynamic Transmission Error (TE), impact of gear meshing eccentric load forces, inherent flexibility in the supporting shaft structure, and influence of torque and power fluctuations originating from a multi-cylinder engine. The estimation of TVMS is carried out for both external-external and external-internal teeth meshing pairs, utilizing the Potential Energy Method (PEM). Subsequently, this study employs the lumped parameter method to establish a model with a specific objective of investigating the lateral-torsional-coupling behavior within adopted PGT model system. The lateral vibration displacement characteristics of the PGT model system is deeply analyzed, revealing the influence of speed on lateral vibration and displacement frequency domain characteristics through a 3D waterfall diagram. Furthermore, a Tooth Profile Modification (TPM) method is applied utilizing two distinct parameters namely ΔTPM parameter and ϑTPM parameter. The objective is to mitigate vibrations and evaluate the performance of the adopted PGT model after employing each TPM parameter through both TVMS and Root Mean Square (RMS).

Callus cultures of Arnebia euchroma (Royle) Johnst can produce considerable amounts of shikonin derivatives, which are shown to possess a wide spectrum of pharmaceutical properties, such as antimicrobial, anticancer, antioxidative, immune regulative and anti-inflammatory. To explore the possible regulation mechanism of shikonin derivatives biosynthesis, the effects of ammonium ion (NH+4) on cell growth and formation of shikonin derivatives in callus cultures of A. euchroma were investigated in this paper. The main results include: When A. euchroma callus were cultured in medium with different concentrations of NH+4(0 mM, 7.02 mM, 14.04 mM), the fresh weight of the cell cultured in 7.02 mM NH+4was higher than those in 0 mM and 14.04 mM NH+4, indicating that NH+4 is necessary for the cell growth of A. euchroma callus cultures, while excessive NH+4concentration (14.04 mM) could rather inhibit the cell growth of A. euchroma. The quantitative analysis of the seven main naphthoquinone compounds showed that the contents of most of the shikonin derivatives (including the bioactive components acetylshikonin and β,β-dimethyl-acrylshikonin) of the Red Strain cultured in 0 mM NH+4condition were higher than those in other NH+4conditions (7.02 mM, 14.04 mM) at most of the sample points, suggesting that NH+4essentially plays an unfavorable role in the biosynthesis of shikonin derivatives. The analysis of quantitative real-time RT- PCR showed that a higher NH+4concentration inhibited the expression of key enzyme genes (such as AePGT) of shikonin derivatives biosynthesis, while -NH+4condition was conducive to the expression of such genes. In sum, our results show that NH+4is necessary for the cell growth of A. euchroma, while unnecessary, or even adversary to the biosynthesis of shikonin derivatives.

Callus cultures of Arnebia euchroma(Royle) Johnst can produce considerable amounts of shikonin derivatives, which are shown to possess a wide spectrum of pharmaceutical properties, such as antimicrobial, anticancer, antioxidative, immune regulative and anti-inflammatory. To explore the possible regulation mechanism of shikonin derivatives biosynthesis, the effects of ammonium ion (NH4+) on cell growth and formation of shikonin derivatives in callus cultures of A. euchromawere investigated in this paper. The main results include: When A. euchromacallus were cultured in medium with different concentrations of NH4+(0 mM, 7.02 mM, 14.04 mM), the fresh weight of the cell cultured in 7.02 mM NH4+was higher than those in 0 mM and 14.04 mM NH4+, indicating that NH4+is necessary for the cell growth of A. euchromacallus cultures, while excessive NH4+concentration (14.04 mM) could rather inhibit the cell growth of A. euchroma. The quantitative analysis of the seven main naphthoquinone compounds showed that the contents of most of the shikonin derivatives (including the bioactive components acetylshikonin and β,β-dimethyl-acrylshikonin) of the Red Strain cultured in 0 mM NH4+condition were higher than those in other NH4+conditions (7.02 mM, 14.04 mM) at most of the sample points, suggesting that NH4+essentially plays an unfavorable role in the biosynthesis of shikonin derivatives. The analysis of quantitative real-time RTPCR showed that a higher NH4+concentration inhibited the expression of key enzyme genes (such as AePGT)of shikonin derivatives biosynthesis, while -NH4+condition was conducive to the expression of such genes. In sum, our results show that NH4+is necessary for the cell growth of A. euchroma, while unnecessary, or even adversary to the biosynthesis of shikonin derivatives.