Vibration analysis of a beam on a moving vehicle under the road excitation with different contact models

Dynamic analysis of a beam on a moving vehicle is presented in this paper. The vehicle is simulated by a four degrees-of-freedom mass-spring system and the beam on top is supported by spring-damping systems. Two contact models named the ‘point contact’ and the ‘patch contact’ respectively, are adopted to simulate the interaction between road surface and vehicular tyres. The equation of motion of the beam-vehicle system is formulated and the dynamic response on the beam under the excitation of the irregular road surface is derived. Numerical simulations are conducted to demonstrate the influence of different factors, such as the length of the contact, the velocity of vehicle, the road condition and the bracing stiffness, etc. on the vibration level of the beam structure, which aims to provide references on the vibration problem in transporting a beam-shaped package

HD-ZIP IV gene Roc8 regulates the size of bulliform cells and lignin content in rice

The morphology of bulliform cells located on the upper epidermis of leaves is one of the most important cell structures affecting leaf shape. Although many mechanisms regulating the development of bulliform cells have been reported, the fine regulatory mechanisms governing this process have rarely been described. To identify novel components regulating rice leaf morphology, a mutant showing a constitutively rolling phenotype from the seedling stage to flowering, known as crm1-D, was selected for further analysis. Anatomical analyses in crm1-D were attributable to the size reduction of bulliform cells. The crm1-D was controlled by a single dominant nuclear gene. Map-based cloning revealed that Roc8, an HD zipper class IV family member, was responsible for the crm1-D phenotype. Notably, the 50-bp sequence in the 3′-untranslated region (3′-UTR) of the Roc8 gene represses Roc8 at the translational level. Moreover, the roc8 knockdown lines notably increased the size of bulliform cells. A series of assays revealed that Roc8 negatively regulates the size of bulliform cells. Unexpectedly, Roc8 was also observed to positively mediate lignin biosynthesis without incurring a production penalty. The above results show that Roc8 may have a practical application in cultivating materials with high photosynthetic efficiency and low lignin content

Strategy evaluation and optimization with an artificial society toward a Pareto optimum

Strategy evaluation and optimization in response to troubling urban issues has become a challenging issue due to increasing social uncertainty, unreliable predictions, and poor decision-making. To address this problem, we propose a universal computational experiment framework with a fine-grained artificial society that is integrated with data-based models. The purpose of the framework is to evaluate the consequences of various combinations of strategies geared towards reaching a Pareto optimum with regards to efficacy versus costs. As an example, by modeling coronavirus 2019 mitigation, we show that Pareto frontier nations could achieve better economic growth and more effective epidemic control through the analysis of real-world data. Our work suggests that a nation’s intervention strategy could be optimized based on the measures adopted by Pareto frontier nations through large-scale computational experiments. Our solution has been validated for epidemic control, and it can be generalized to other urban issues as well

Water Oxidation with Cobalt‐Loaded Linear Conjugated Polymer Photocatalysts

We report here the first examples of linear conjugated organic polymer photocatalysts that produce oxygen from water after loading with cobalt and in the presence of an electron scavenger. The oxygen evolution rates, which are higher than for related organic materials, can be rationalized by a combination of the thermodynamic driving force for water oxidation, the light absorption of the polymer, and the aqueous dispersibility of the relatively hydrophilic polymer particles. We also used transient absorption spectroscopy to study the best performing system and we found that fast oxidative quenching of the exciton occurs (picoseconds) in the presence of an electron scavenger, minimizing recombination

Comparison Between Electropositive and Electronegative Cold Atmospheric-Pressure Plasmas: A Modelling Study

Cold atmospheric-pressure He + N2 and He + O2 plasmas are chosen as the representatives for electropositive and electronegative plasmas, of which the discharge characteristics are studied and then compared to each other by fluid models. As the increase of the impurity (N2 or O2) fraction from 0 to 10%, for He + N2 plasmas the electron density and ion density increase, the spatiotemporal distributions of electron density, ion density, electron temperature and electron generation rate change a little. On contrast, for He + O2 plasmas the electron density decreases, the ion density first increases and then decreases, the electron temperature increases in the bulk region, but decreases in the sheath region, and the plasmas transform from ᵞ mode to α mode as the significant change of electron generation rate distributions. Larger electric field is needed in the bulk region to sustain the electronegative plasma, so the electrical characteristics of He + O2 plasmas transform form capacitive to resistive with increasing O2fraction. Meanwhile, the ion-coupling power increases dramatically, which can be estimated by a formula based on the electronegativity. A new criterion for determining the sheath boundary, |ΔE| = 5 kV/cm2, is put forward, which is found suitable for both the electropositive and electronegative plasmas

Polo-like kinase 1 siRNA-607 induces mitotic arrest and apoptosis in human nasopharyngeal carcinoma cells

Polo-like kinase (Plk) 1 is overexpressed in many human malignancies including nasopharyngeal carcinoma, indicating its potential as a therapeutic target. Recently, using a simple cellular morphologybased strategy, we have identified several novel effective siRNAs against Plk1 including Plk1 siRNA- 607. In this study, we further investigated the effects of Plk1 siRNA-607 in human nasopharyngeal carcinoma cell line, HNE-1. Real time RT-PCR and Western blot indicated that Plk1 siRNA-607 transfection resulted in a significant inhibition in Plk1 expression in the HNE-1 cells. Furthermore, cell cycle, cell growth and apoptosis analysis clearly indicated that Plk1 siRNA-607 caused a dramatic mitotic cell cycle arrest followed by massive apoptotic cell death, and eventually resulted in a significant decrease in growth and viability of the nasopharyngeal carcinoma cells. Given that Plk1 has been widely accepted as a novel efficient target for cancer therapy, these results suggested that Plk1 siRNA-607 could be further developed for the treatment of human nasopharyngeal carcinoma.Key words: Nasopharyngeal carcinoma, Plk1, RNA silencing, cell cycle, apoptosis