DFT Study on the Substituent Effect of Anticancer Picoline-Diazido-Pt(IV) Compounds

The geometric structure of azido Pt(IV) compounds containing picoline was calculated by using density functional theory(DFT) at the LSDA/SDD level. The ESP distribution shows the possible reaction sites of the compounds. In addition, the frequency calculation results assigned the infrared spectra of these compounds, and specified important stretching and bending vibrations. The HOMO-LUMO energy gaps of these compounds are also calculated to explain the charge transfer of the molecules. The distribution of Mulliken charges and natural atomic charges of these atoms is also calculated. Natural bond orbital(NBO) analysis explains the intramolecular interactions and their electron density.

A frequency determination method for automotive nanosensors

The growing popularity of nanosensors in various automotive applications requires new methods for counting the frequency of electrical signals, into which the measured non-electrical parameters are converted. This need is because automobile nanosensors are to register very small changes in the measured parameters that, besides, can change very fast. The paper proposes for use in automotive nanosensors a frequency calculation method based on the principle of rational approximation, which meets the above requirements.

Free Vibration and Frequency Calculation in Tall Buildings with Stepped Tube-in-Tube Systems

This study investigates the free vibration and frequency analysis of tall buildings with stepped cross-sections for stepped tube-in-tube structures. Dynamic equations were presented in accordance with the stepped structural system for free vibration and the differential equations were solved according to the application of boundary conditions and flexural and shear stiffness and stepped cross-section of different steps. The answer was converted to an 8x8 matrix and was obtained using the determinants of matrix and mathematical calculations of frequency. Nine mathematical computational models were designed for stepped tube-in-tube structures for a 50-story tube-in-tube building by increasing the height of the outer tube by 15 meters. Finally, the heights of the inner and outer tubes were equalized by increasing the height of the outer tube and then compared with the results of free vibration in the articles with the tube-in-tube structural system with equal height and characteristics. Using this method, the frequency of structures was calculated correctly and the obtained results from finite element analysis showed that this mathematical method accurately calculated the frequency. It was found that this method was accurate enough and the obtained computational error was very small. The results showed that the frequency decreases by adding to the outer tube and increasing its height.

Dynamic Characteristics Analysis of Cylinders Bundle Coupling System Under Axial Flow

Nuclear reactor fuel assemblies are mainly composed of cylinders bundle(CB), calculating the dynamics characteristics of CB under axial flow can lay a foundation for predicting fretting wear and vibration fatigue. In the paper, the CB coupling dynamic model of forced vibration under pulsating flow is established. And the stability analysis and natural frequency calculation of the CB system under steady flow are compared with the existing results to verify the model. Finally, the Runge-Kutta method is applied to solve the forced vibration equation of the CB under pulsating flow. The influence of the pulsating parameters m, w0, on the amplitude-frequency characteristics and the motion trajectory of the midspan cross section of the CB under forced vibration are analyzed and discussed. The results show that the pulsating parameters have an important influence on the vibration of the CB system.

Increasing social anxiety in the context of globalization of migration processes as a problem of international relations

Research background: Increasing inward and outward labor migration flows between Central Asian countries and Russia are very significant for both sides. Migration processes in the Central Asian region play an important role in stabilizing international relations, because their economic, political and social results are important for all the countries in the region. The Russian Federation is one of the countries which receives the most immigrants, along with the United States, Germany, France and Canada. Migrants with different ethnicities from Central Asia constitute most of the migratory flows to Russia. Purpose of the article: The authors aimed to analyze the growing social anxiety about the rising influx of migrants from Central Asian countries in Russia, as an indicator of the risk of developing damaging social processes. Methods: The authors draw their conclusions from the results of a questionnaire survey given to residents of Yekaterinburg in 2016 (N=485) and 2019 (N=476), and a comparison of comments on the internet from Russians in 2019 and 2020 about the behavior of migrants from Central Asian countries. The methods for analysis include a descriptive analysis, correlation analysis, content analysis, comparative analysis, words clustering analysis and quantitative word frequency calculation. Findings & Value added: The authors conclude that the increasing social anxiety from residents of Yekaterinburg about the rising influx of migrants from Central Asian has moved to the next stage of latent conflict, which R. Darendorff describes as the stage of “awareness of latent interests”. The obtained results are important for the regulation of processes inter-country relations in the field of migration exchanges.

Quantum Field of Functional Density

For the first time in scientific and engineering practice, it is logically and mathematically substantiated, computationally verified and metrologically confirmed that classic and quantum physics, analytical and quantum chemistry, as well as continuous symbolic and discrete digital mathematical analysis, all have computational limits of information entropy, upper 1/10^16 and lower 1/10^64. Mutual displacement of these limits relatively center of Euclidean three-dimensional and of Cartesian two-dimensional space generate sets of quantum dots of mesh topology and weighted average harmonic units of quantum metrics of internal atomic and outer cosmic space, as well as determines limits of communication speed, clock frequency, calculation power and accuracy for any computing machine with subatomic elements of memory. The matrices of functional density and entropy of energy and information fields reconciles classic and quantum physics with continuous and discrete mathematics of special and general relativity.

Acceleration Frequency Characteristics of the Freight-Train-Induced Vibration of the Beijing-Harbin Railway Subgrade

The vibration acceleration during a freezing period was monitored in the Beijing-Harbin railway subgrade, and its frequency characteristics were studied. The results show the following. (1) The vibration acceleration frequency of the railway subgrade was divided into three main bands: the first frequency band is caused by the vehicle wheelbase, the second frequency band is caused by the sleeper spacing, and the third frequency band is mainly affected by the track irregularity spectrum and site structure. (2) The fitted dominant frequency, as can be seen from the monitored results, is in good agreement with the calculated value from the vibration frequency calculation formulas. (3) From the monitoring, it can be seen that train type, traveling speed, and train formation have a significant influence on the dominant frequencies of the first and second bands. Train formation, load, and distance from the track have a great influence on the amplitude of each frequency band.