Nanotechnology : the development , application - XXI Century最新文献

{"title":"Thermoelastic martensitic transition and shape memory effect in Ti2NiCu alloy at micro- and nanoscale","authors":"P. Lega","doi":"10.18127/j20700970-202102-04","DOIUrl":"https://doi.org/10.18127/j20700970-202102-04","url":null,"abstract":"Problem. An important fundamental problem in condensed matter physics is the study of the physical properties of various materials at the nanoscale size. A deep understanding of size effects is necessary when studying multifunctional solid materials with phase transitions and giant effects, such as magnetocaloric, elastocaloric, shape memory effect (SME). Goal. Direct experimental study of the manifestation of the thermoelastic martensitic transition and the accompanying SME in the Ti2NiCu alloy at the nanoscale in transmission electron microscope (TEM). Result. For the first time in a TEM during heating and cooling, the observed SME in nanocomposite amorphous-crystalline Ti2NiCu samples while observing the evolution of the structure of martensitic twins and the shape of changes. Investigations are carried out on wedge-shaped samples with variable thickness from 200 to 20 nm, in the form of a composite bimetallic nano-actuator, using the original method of local etching and polishing with a focused ion beam (FIB). Practical significance. These findings open the pathway for size limit indications and regime modulations where the alloy-based nanomechanical devices can be tuned to operate more efficiently.","PeriodicalId":299896,"journal":{"name":"Nanotechnology : the development , application - XXI Century","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122260069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radiographic method for assessing the quality of sugar beet seeds","authors":"N. Potrakhov, O. Podvigina, N. Staroverov, Y. Potrakhov","doi":"10.18127/j22250980-202102-06","DOIUrl":"https://doi.org/10.18127/j22250980-202102-06","url":null,"abstract":"Currently, sugar beet is the main source of sugar in the Russian Federation. The use in modern production of intensive technologies for the cultivation of sugar beets, the main requirement of which is sowing seeds to the final density, entails the improvement and development of methods for pre-sowing preparation of seed material with high sowing qualities - laboratory germination not lower than 90-95%, single germination - 97-99 %, high germination energy and resistance to pathogens. Therefore, the problem of improving the quality of seeds is one of the most important tasks of crop production. The traditional assessment of the sowing qualities of selected seed samples is carried out according to standard methods in laboratory conditions, and further studies of this material become impossible. An alternative method for studying the qualitative characteristics of seeds is the non-destructive method of microfocus X-ray, which makes it possible to identify various anomalies in seed development and to study the relationship between the features of hidden structural defects of seeds and their biological properties. The uniqueness of the method lies in the fact that the biological and economic significance of defects and developmental anomalies can be identified from X-ray images of captured seeds with subsequent study and comparison with the results of plant growth and development. The purpose of the performed studies was the development of a promising X-ray technique for assessing the quality of sugar beet seeds. As a result of many years of joint research of the employees of the «Russian Scientific research institute of sugar beet and sugar» and Saint Petersburg Electrotechnical University \"LETI\", X-ray signs were determined, which made it possible to assess their viability by the image of seeds. All radiographic signs were conventionally divided into positive and negative. Positive traits characterize the structure of normally fulfilled viable seeds, negative ones indicate the presence of developmental defects.","PeriodicalId":299896,"journal":{"name":"Nanotechnology : the development , application - XXI Century","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133623680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical techniques of the estimation the amount of waveguides surface roughness for the THz regime","authors":"N. V. Fedorkova, A.A. Sultanshin","doi":"10.18127/j22250980-202101-02","DOIUrl":"https://doi.org/10.18127/j22250980-202101-02","url":null,"abstract":"The article is devoted to the problem of the efficient design of THz waveguides devices. Extreme small sizes of THz devices such as subharmonic pumped mixers for radiometer witch waveguides are integrated in copper block covered with 3 μm gold are presented. The three numerical techniques and direct measurements in the THz regime have been used to predict the effective conductivity reduction due to protrusions. Efficient design of THz systems requires the ability to predict effective conductivity, allowing engineers to determine the amount of surface roughness for acceptable reflection losses prior to fabrication. Full-wave numerical technique to predict the field enhancement factors for both the rf electric field and the rf magnetic field on the protrusion above smooth sample in the THz regime has been mentioned. The electric field and magnetic field enhancement factors on the hemispherical protrusion should be excluded in case the protrusions size are smaller than δ/50 and δ/1.5 correspondingly (δ is skin depth). Mie-Scattering-based approach approximates a unit cell of the grating as a circular cylinder protrusion the additional loss due to the protrusion compared with a perfectly flat surface of the same material. Hammerstad–Bekkadal Model demonstrates an analytical function which depends of sheet resistance for a sample with surface roughness on the surface roughness and skin depth of the metal. Numerical calculations using this technique predict 10% power absorption due to surface features 35 nm at 400 GHz. A layout of the apparatus for direct measurements of the effective conductivity of samples with roughness features using an open quasi-optical resonator is given. The results of theoretical calculation and empirical evaluation have been compared with computer simulation software taking into consideration of the effective conductivity only due to the change in the surface geometry. The comparison empirical results and numerical calculations full-wave numerical technique are more accurate for samples that are smooth relative to the skin depth. For surface features greater than the skin depth, we found the Hammerstad and Bekkadal model to be a better. The observed methods can be used as a rapid means to estimate waveguides surface roughness in terms of power loss in the THz regime.","PeriodicalId":299896,"journal":{"name":"Nanotechnology : the development , application - XXI Century","volume":"118 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131817955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nucleation, first growth stages and structure of nano-sized polymer coatings deposited from active gas phase","authors":"A. Rogachev","doi":"10.18127/j22250999-201901-02","DOIUrl":"https://doi.org/10.18127/j22250999-201901-02","url":null,"abstract":"This paper presents an analysis of the structural-morphological, kinetic patterns of the initial growth stages of single-component and composite (polymer-polymer and metal-polymer) nanoscale coatings based on the products of electron-beam dispersion of polymers. The main features of the deposition processes from the active gas phase occurring on the substrate surface and the established size dependences of the structure and molecular composition are explained on the basis of the adsorption-polymerization mechanism for the formation of coatings. It was established that among the most important features of the deposition process from the active gas phase is the simultaneous flow of polymerization and structure formation of adsorbed molecular fragments of the polymer under the conditions of exposure of the active components of the plasma, dispersive filler, and the substrate surface. This feature has a decisive influence on the nucleation of polymer particles, the molecular structure and morphology of nanoscale layers, as well as the dependence of their properties on thickness. Using the PTFE and PE coatings, it was shown that the orientation and ordering of the formed layers changes during the coating growth: at the initial stages of deposition in the layer up to 150 nm, the molecules are oriented predominantly parallel, and in thicker layers due to the bulk structure formation perpendicularly substrate surface. When deposited on the surface subjected to plasma treatment, the growth rate of the formed coating at the initial stages of growth increases by more than 5 times. At the same time, such layers contain predominantly linear molecules with a relatively lower molecular weight. The introduction of micro-and nanoscale polymer coatings in the process of their growth of the formed silver or copper nanoclusters leads to the formation of highly oriented, continuous, highly dispersed layers already at the initial stages of growth. The orientation of the macromolecules of the matrix with the maintenance of Ag or Cu nanoclusters in it has parameters characteristic of single-component coatings. In PTFE+Mo coatings, a linear dependence of molecular orientation on the layer thickness appears. In composite coatings containing silver nanoclusters, the effect of selective plasmon absorption was established.","PeriodicalId":299896,"journal":{"name":"Nanotechnology : the development , application - XXI Century","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116040281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The analysis of the network structures in high tech industrial enterprises","authors":"E. Gorlacheva, E. Ivannikova, A. Vasilenko","doi":"10.18127/j22250980-202101-03","DOIUrl":"https://doi.org/10.18127/j22250980-202101-03","url":null,"abstract":"The relevance of information and the speed of its processing are of significant importance for high-tech industrial enterprises. To solve this problem, R&D departments are created within enterprises, but often all efforts are broken down by inefficient organizational structures. Purpose of the research– identify patterns that will ensure the most productive work with innovations. For the dissemination of new ideas in the enterprise, the role distribution of employees is more important. The impact of the ability to freely share information does not affect the results as much as the change in the ratio of different types of employees. The determined share of conservative employees (30-40% of the total number) allows us to determine the optimal ratio of employees who test innovative ideas for adequacy, in order to maximize the number of successfully accepted ideas by the team.","PeriodicalId":299896,"journal":{"name":"Nanotechnology : the development , application - XXI Century","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116902292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}