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1.
Voronov V. A. Dergachev E. A. Zhukovskii M. E. Neopryatnaya A. M. 《Mathematical Notes》2021,109(1-2):29-37
Mathematical Notes - The problem of finding the least number of variables of a first-order formula expressing the statement that an input-graph contains a subgraph isomorphic to a given... 相似文献
2.
Doklady Mathematics - New properties of convex infinitely differentiable functions related to extremal problems are established. It is shown that, in a neighborhood of the solution, even if the... 相似文献
3.
Mayboroda I. O. Kolobkova E. M. Grishchenko Yu. V. Chernykh I. A. Zanaveskin M. L. Chumakov N. K. 《Crystallography Reports》2021,66(3):520-524
Crystallography Reports - The formation of β-Si3N4 for subsequent growth of AlGaN and GaN heterostructures of silicon wafers has been studied. It is established that the native oxide layer... 相似文献
4.
Crystallography Reports - Methods of coherent X-ray diffraction imaging of the spatial structure of noncrystalline objects and nanocrystals (nanostructures) are considered. Particular attention is... 相似文献
5.
Patel Chirag N. Kumar Sivakumar Prasanth Pandya Himanshu A. Rawal Rakesh M. 《Molecular diversity》2021,25(1):421-433
Molecular Diversity - The pandemic outbreak of the Corona viral infection has become a critical global health issue. Biophysical and structural evidence shows that spike protein possesses a high... 相似文献
6.
Khabensky V. B. Almjashev V. I. Granovsky V. S. Krushinov E. V. Vitol S. A. Kotova S. Yu. Gusarov V. V. 《Technical Physics》2021,66(2):221-228
Technical Physics - In the case of a severe accident at a nuclear power plant with light-water reactors, the most effective method for localization of the formed melt (corium) is its retention in... 相似文献
7.
Russian Physics Journal - The paper shows that the values of zero-point energy and vibrations of atoms in a crystal determined by the uncertainty principle, depend on the dynamic response of atoms.... 相似文献
8.
Abiola O. Ajayeoba Adewoye A. Olanipekun Wasiu A. Raheem Oluwaseun O. Ojo Ayowumi R. Soji–Adekunle 《声与振动》2021,55(1):69-85
Economic wood processing employs the use of industrial machines for cutting, shaping, milling, and sawing timber, thereby leading to the generation of high levels of noise. Published data from empirical studies have categorized noise as an environmental hazard of global significance. Furthermore, noise exposure limits for different industries and all the industrial machines available has not been formally established as it presently exists in developed nations around the world. Therefore, this study assessed the daily exposure of sawmills workers to noise in Southwestern Nigeria. Reconnaissance surveys were first carried out in Osun, Oyo, Ondo, Ekiti, Lagos, and Ogun States to select sawmills that were fully operational and fit for the study. Two fully functional sawmills in two cities of each State were eventually selected for data collection, making a total of 24 sawmills, while the Circular Machines (CM), Planer Machines (PM), and Band-saw Machines (BM) were the machines in each sawmill considered. Two machines each of CM, PM, and BM were considered in each sawmill, making a total of forty-eight (48) machines each of CM, PM, and BM. Sound data were collected between 7 am and 7 pm each day for six days (between Monday and Saturday) using Extech 407732 sound level meter and all stabilized measurements were taken three times at different intervals. The data collected were in three different periods: Machine No-work Period (NPm), Machine Idle Period (IPm), and Machine Working Period (WPm). A two–way Analysis of Variance (ANOVA) was carried out at P < 0.05 to determine whether there is a significant difference in the sound level average before and after the break, for both the idle and working periods of the three machines considered. This was also done to determine whether there is a significant difference between the sound level average of the results collected during idle and working periods of the three machines. Noise Pollution Levels (Lnp) ranged from 83.20 dB (PM) to 107.65 (BM) and 93.42 (CM and PM) – 116.00 (BM) respectively, while IPm also gave the least noise pollution level of 95.79 dB and WPm gave the highest level of 102.88 dB. The results revealed that all the machines’ Lnp values in the working period are more than the 90 dB acceptable limit the recommendation value of 90 dB while 89.6% of CMs, 75% of PMs, and 89.6% of BM had their Lnp above 90 dB in the idle period respectively. The minimum and the maximum noise dose levels for IPm, WPm and overall are 0.09 (BM) and 2.37 (CM), 0.50 (CM), and 4.77 (PM) and 0.69 (BM) and 6.64 (PM) respectively. The study found out that the fundamental contributing factors to the high noise levels in sawmills are poor machine maintenance, use of old and obsolete machines, poor housekeeping strategy, limited space, workers’ negligence, lack of PPE, and lack of occupational safety training. The study recommends that proper workplace practices such as use of personal protective equipment, new and modern machines, training, and occupational safety programmes be implemented in the considered sawmills. 相似文献
9.
Breev I. D. Likhachev K. V. Yakovleva V. V. Veishtort I. P. Skomorokhov A. M. Nagalyuk S. S. Mokhov E. N. Astakhov G. V. Baranov P. G. Anisimov A. N. 《JETP Letters》2021,114(5):274-278
JETP Letters - The effect of static mechanical strain on the splitting of spin sublevels of color centers based on spin 3/2 silicon vacancies in silicon carbide at room temperature has been shown.... 相似文献
10.
JETP Letters - It is shown that the intrinsic magnetization of transition metal dichalcogenide monolayers calculated within the two-band model depends significantly on the boundary conditions on... 相似文献