Boron carbide has unique properties for wide application possibilities;however,poor sinterability limits its applications.One approach to overcome this limitation is the addition of secondary phases into boron carbide...Boron carbide has unique properties for wide application possibilities;however,poor sinterability limits its applications.One approach to overcome this limitation is the addition of secondary phases into boron carbide.Boron carbide based composite ceramics are produced by the direct addition of secondary phases into the structure or via reactive sintering using a sintering additive.The present study investigated the effect of Ti_(3)SiC_(2) addition to boron carbide by reactive spark plasma sintering in the range of 1700-1900℃.Ti_(3)SiC_(2) phase decomposed at high temperatures and reacted with B4C to form secondary phases of TiB2 and SiC.The results demonstrated that the increase of Ti_(3)SiC_(2) addition(up to 15 vol%)effectively promoted the densification of B4C and yielded higher hardness.However,as the amount of Ti_(3)SiC_(2) increased further,the formation of microstructural inhomogeneity and agglomeration of secondary phases caused a decrease in hardness.展开更多
A streamlined shape of the best swimmers removes the boundary-layer separation and ensures a laminar flow pattern.The fastest fish have a very sharp convex nose(rostrum),the purpose of which remains unclear.The bodies...A streamlined shape of the best swimmers removes the boundary-layer separation and ensures a laminar flow pattern.The fastest fish have a very sharp convex nose(rostrum),the purpose of which remains unclear.The bodies of revolution similar to their shapes are analyzed in steady underwater and floating motion.The sources and sinks were located on the axis of symmetry and above the water surface to estimate the pressure on the body and the vertical velocities on the water surface.It was shown that the flow patterns on a special shaped body with concave nose has no stagnation points and ensure small values of the water surface elevation.These fact allow diminishing the maximum pressure on the surface and wave drag.Special shapes with the sharp concave nose and negative pressure gradients on their surface could be parts of the low drag underwater and floating hulls.展开更多
The main reasons for the occurrence of temperature error and perspective directions of decreasing of its value are presented by improving the device design based on the phenomenon of surface plasmon resonance (SPR) an...The main reasons for the occurrence of temperature error and perspective directions of decreasing of its value are presented by improving the device design based on the phenomenon of surface plasmon resonance (SPR) and numerical methods of processing the results of measurements by this device. The most essential influence on changes in results of measurements can be rendered by temperature changes in the analyte refractive index. It is shown that the application of the integrated temperature stabilization of the device with the test substance, and numerical processing of the measurement results for compensation of temperature changes of the test substance and the use of film heaters it is possible to reduce the measurement error of the refractive index of the analyte at least 30 times from 2.4 × 10-4 to 7.6 × 10-6.展开更多
The mechanisms of influence of physiotherapy procedures in ozokeriteparaffin therapy are considered in this paper.It is shown that microwave electromagnetic radiation formed by heated ozokerite-paraffin mixture is an ...The mechanisms of influence of physiotherapy procedures in ozokeriteparaffin therapy are considered in this paper.It is shown that microwave electromagnetic radiation formed by heated ozokerite-paraffin mixture is an important component of physiotherapy procedures.Using the experimental setup developed by the authors,the radiative abilities of ozokerite,paraffin and their mixtures in the microwave range were investigated.It was found that in the process of cooling the ozokerite-paraffin mixture,during the procedure,negative microwave fluxes occur,affecting the inflammatory processes in the patient’s body.The dependences of the microwave radiation level on the composition of the ozokerite-paraffin mixture are investigated.The results of experimental studies allowed us to evaluate the interaction of electromagnetic radiation of ozokerite-paraffin mixtures with human own electromagnetic radiation and to approach the choice of modes of therapeutic interaction more carefully.展开更多
In times of active research of the possibilities of colonization of other planets,it is important to acquire the skills of forecasting weather conditions on the planets,which are the prospects for human settlement.In ...In times of active research of the possibilities of colonization of other planets,it is important to acquire the skills of forecasting weather conditions on the planets,which are the prospects for human settlement.In this research,the theoretical model is developed that describes the physical processes that occur in the atmosphere of Mars in order to calculate the surface temperature of the planet for any point of the planet’s area,time of day,and day of the year.The following theoretical model is implemented in computer software realized by Python programming language to calculate the necessary data.展开更多
基金YOK(MEVLANA 2018-9999-Proj-ect-Based International Exchange Programme)for financial support in inter-national collaboration.
文摘Boron carbide has unique properties for wide application possibilities;however,poor sinterability limits its applications.One approach to overcome this limitation is the addition of secondary phases into boron carbide.Boron carbide based composite ceramics are produced by the direct addition of secondary phases into the structure or via reactive sintering using a sintering additive.The present study investigated the effect of Ti_(3)SiC_(2) addition to boron carbide by reactive spark plasma sintering in the range of 1700-1900℃.Ti_(3)SiC_(2) phase decomposed at high temperatures and reacted with B4C to form secondary phases of TiB2 and SiC.The results demonstrated that the increase of Ti_(3)SiC_(2) addition(up to 15 vol%)effectively promoted the densification of B4C and yielded higher hardness.However,as the amount of Ti_(3)SiC_(2) increased further,the formation of microstructural inhomogeneity and agglomeration of secondary phases caused a decrease in hardness.
文摘A streamlined shape of the best swimmers removes the boundary-layer separation and ensures a laminar flow pattern.The fastest fish have a very sharp convex nose(rostrum),the purpose of which remains unclear.The bodies of revolution similar to their shapes are analyzed in steady underwater and floating motion.The sources and sinks were located on the axis of symmetry and above the water surface to estimate the pressure on the body and the vertical velocities on the water surface.It was shown that the flow patterns on a special shaped body with concave nose has no stagnation points and ensure small values of the water surface elevation.These fact allow diminishing the maximum pressure on the surface and wave drag.Special shapes with the sharp concave nose and negative pressure gradients on their surface could be parts of the low drag underwater and floating hulls.
文摘The main reasons for the occurrence of temperature error and perspective directions of decreasing of its value are presented by improving the device design based on the phenomenon of surface plasmon resonance (SPR) and numerical methods of processing the results of measurements by this device. The most essential influence on changes in results of measurements can be rendered by temperature changes in the analyte refractive index. It is shown that the application of the integrated temperature stabilization of the device with the test substance, and numerical processing of the measurement results for compensation of temperature changes of the test substance and the use of film heaters it is possible to reduce the measurement error of the refractive index of the analyte at least 30 times from 2.4 × 10-4 to 7.6 × 10-6.
文摘The mechanisms of influence of physiotherapy procedures in ozokeriteparaffin therapy are considered in this paper.It is shown that microwave electromagnetic radiation formed by heated ozokerite-paraffin mixture is an important component of physiotherapy procedures.Using the experimental setup developed by the authors,the radiative abilities of ozokerite,paraffin and their mixtures in the microwave range were investigated.It was found that in the process of cooling the ozokerite-paraffin mixture,during the procedure,negative microwave fluxes occur,affecting the inflammatory processes in the patient’s body.The dependences of the microwave radiation level on the composition of the ozokerite-paraffin mixture are investigated.The results of experimental studies allowed us to evaluate the interaction of electromagnetic radiation of ozokerite-paraffin mixtures with human own electromagnetic radiation and to approach the choice of modes of therapeutic interaction more carefully.
文摘In times of active research of the possibilities of colonization of other planets,it is important to acquire the skills of forecasting weather conditions on the planets,which are the prospects for human settlement.In this research,the theoretical model is developed that describes the physical processes that occur in the atmosphere of Mars in order to calculate the surface temperature of the planet for any point of the planet’s area,time of day,and day of the year.The following theoretical model is implemented in computer software realized by Python programming language to calculate the necessary data.
