Novel coronaviruses can attach to other substances to become composite particles and do damage to the human body.The deposition characteristics of thermophoresis were obtained by calculations under different ambient temperatures and human body temperatures.Under the same conditions of only considering the thermophilic effect,the higher the temperature difference between air and airway wall,the higher the thermophilic speed of virus particles,and the easier they are deposited in the respiratory tract and alveoli;the higher the ambient temperature and the lower the body temperature,the higher the deposition rate of virus particles,By calculating the characteristics of deposition in different ambient temperature and human body temperature,but under the same conditions considering only thermophoretic effects,we result that:the higher the temperature of air than the wall of air duct is,the higher the thermal swimming speed of virus particles is,and it is easier to deposit in the respiratory tract and alveoli;the higher the ambient temperature is and the lower the body temperature is,the higher the deposition rate of virus particles is,the easier it is to infect people with novel coronavirus and enhance the effect of virus;the lower the ambient temperature is and the higher the body temperature is,the virus particles may be affected by anthermophoretic force during transportation,thus preventing the deposition of virus particles in the human body.Humans may be more susceptible to the virus in the spring and summer when their body temperature drops.
Missing data is a problem that cannot be ignored.When the proportion of missing data is high,it will seriously affect the test results,so it is particularly important to deal with missing data.To address this issue,the built-in data set of R is used,and the column deletion,single imputation and multiple imputation methods are used.Under the conditions that the data is missing 10%,25%,50%and 75%,the three methods are used for imputation to perform a statistical test on the imputed data.The results show that when the missing proportion is small,the results of the three methods do not differ much,and the simpler column deletion can be chosen.However,as the proportion of missing increases,the difference between the results of different methods gradually increases,and the relatively stable method is multiple imputation,and the difference between the results and the real data is smaller.
Based on the self-made dynamic circulating cooling water experimental platform,different concentrations of hard water were used as experimental water,and the effects of individual and combined actions were compared by adjusting the magnesium ion concentration and applying ultrasonic waves.The results showed that the average scale inhibition rate reached 97.82%after the magnesium ion concentration of 3 mmol/L and the application of ultrasonic waves with a frequency of 30 kHz and a power of 600 W.Moreover,the composite effect reduced the viscosity of the solution and inhibited the precipitation of scale-forming substances.By X-ray diffraction(XRD)and scanning electron microscopy(SEM)analysis,the combined effect of the two reduces the grain size of the fouling and transforms the fouling samples to the direction of spheroidal aragonite,which achieves the effect of scale inhibition and scale suppression.
In order to establish a physical analytical model that can more accurately and truly reflect the transient temperature field and thermal error changes of the spindle,this paper proposes a spindle thermal network model that considers radiation heat transfer and transient heat generation of the bearings.Firstly,the mechanism of thermal structural interaction of the bearings in the spindle system and its influence on the heat generation rate are analyzed,and the time-varying heat generation rate of the bearings is calculated.Then,the influence of radiation heat transfer on temperature field and thermal error of the spindle system are analyzed and discussed.Based on the radiation network,a calculation method for heat dissipation of the spindle system through radiation heat transfer is proposed.Finally,a calculation method of introducing radiant heat transfer into the heat network model is proposed,and a better analytical model of spindle temperature field and thermal error is established.In order to verify the accuracy and generalization ability of the model,experiments are conducted on the thermal characteristics of the spindle system at different rotational speeds,ambient temperatures and initial structural temperatures.The results show that the influence of radiation heat transfer on spindle temperature field and thermal error cannot be ignored,and the accuracy of the physical analytical model considering radiation heat transfer is higher.
For the experimentally obtained double-layer ice system,a quasi-3D hexagonal lattice system simulating the double-layer ice structure is designed and developed by using the protocell dynamics mean-field theory in combination with the continuous-time quantum Monte Carlo method,and the effect of the strong correlation interactions with the competing temperatures on the metal-Mott insulating phase transition in the system is investigated.The results show that,by calculating the density of states,the double occupancy number and the Fermi surface of the system,the metal-Mott insulating phase transition(e.g.,UC/t=6.5 at T/t=0.2)through which the oxygen atom passes as the interaction increases is a secondary phase transition.Due to the temperature-dependent formation of Kondo resonance peaks in the system,the Fermi surface of the hydrogen atom always has a sharp Fermi liquid peak.The double-layer ice experiment is used as a basis to simulate the process of quantum phase transition occurring in it,and the calculation results will provide a theoretical reference for the study of strong correlation of double-layer ice.
