空盒气压表示值修正值的不确定度评定

一、概述1.测量依据JJG272-2007《空盒气压表和空盒气压计》检定规程。2.环境条件实验室内没有阳光直接照射、过大的空气流动和较大的震动,室内温度波动度不大于±2℃。     

空盒气压表计量检定技术解析

空盒气压表被广泛的应用于气象台站、环保、地矿、实验室等部门进行大气压力的测试.为确保该类仪器测量时的准确可靠,探讨空盒气压表的计量检定技术十分重要.本文依据JJG272-2007《空盒气压表和空盒气压计检定规程》分析空盒气压表温度系数、示值检定、补充修正等三个步骤的计量检定.     

空盒气压表温度系数随温度响应关系的研究

在不同温度范围和不同温度变化幅度条件下,依据JJG 272-2007《空盒气压计和空盒气压表检定规程》要求,对不同空盒气压表在设定条件下温度系数的响应情况进行了研究.结果表明:空盒气压表在偏离室温越大、温差幅度越大的情况下,温度系数变化越明显.主要原因是由于空盒气压表在气体压力作用下发生的弹性形变与膜盒组受温度变化热胀冷缩使得膨胀系数变化的共同作用下,导致温度系数发生较大变化.     

温度系数对空盒气压表检定结果的影响

描述了JJG 272-2007规定的空盒气压表温度系数检测方法。通过实验方法分析了温度系数对空盒气压表检定结果的影响。研究结果表明了在空盒气压计检定过程中用出厂温度系数替代实测温度系数的可能性。     

基于空盒气压表温度系数的研究

根据JJG 272-2007规定的空盒气压表温度系数检测方法,选用宁波市鄞州姜山玻璃仪器仪表厂生产的六块DYM3型空盒气压表进行试验。试验中选用两组不同的高低温度点进行测量,得到六块空盒气压表的两组温度系数,同时分别对比生产厂家给出的温度系数,并计算两者的误差。试验结果表明由出厂温度系数与实测温度系数之差引起的气压差平均值测量误差可忽略不计,其对检定结果不产生影响。因此在检定新出厂未使用的空盒气压表时,可采用出厂温度系数作为参考,从而简化检定流程提高工作效率。     

音速喷嘴气体流量标准装置测量值的不确定度评定

依据JJF1059.1-2012《测量不确定度评定与表示》及JJG1037-2008《涡轮流量计》、JJG635-2005《气体容积式流量计》、JJG1030-2007《超声波流量计》检定规程评定了音速喷嘴气体流量标准装置的测量结果不确定度。建立了评定测量结果不确定度的数学模型,分别分析了各种流量计测量状态中的不确定度分量,并分别计算了合成不确定度和测量结果的扩展不确定度。     

荧光分光光度计检出极限校准结果的不确定度评定

依据JJF 1059-1999《测量不确定度评定与表示》及JJG537-2006《荧光分光光度计》检定规程评定了荧光分光光度计检出限测量结果的不确定度。建立了评定检出限测量结果不确定度的数学模型,分析了各不确定度分量,并计算了合成不确定度和测量结果的扩展不确定度。     

液压千斤顶示值测量结果的不确定度评定

本文依据GJB3756-99《测量不确定度的表示及评定》和JJF1059-1999《测量不确定度评定与表示》,以检定液压千斤顶为例,评定了测量结果的不确定度。建立数学模型,将各不确定度分量合成,并计算其测量结果的扩展不确定度。     

医用诊断X辐射源辐射输出的空气比释动能率测量不确定度评定

一、概述 1.测量标准和设备 依据JJG744-2004<医用诊断X射线辐射源>检定规程,在规定的测最条件下,使用不确定度小于5%的医用诊断X射线辐射源检定装置(其配套设备有非介入电压表、非介入电流表、半值层仪、星卡、分辨力卡、空盒气压表等),对工作级医用诊断X射线辐射源进行检定.     

液相色谱-原子荧光联用仪最小检测量不确定度评定

本文根据JJG 1151-2018《液相色谱-原子荧光联用仪检定规程》和JJF 1059. 1-2012《测量不确定度的评定与表示》,分析了各不确定度分量,建立了评定最小检测量不确定度的测量模型,评定了液相色谱-原子荧光联用仪最小检测量的不确定度。     

Psychosocial safety climate as a lead indicator of workplace bullying and harassment, job resources, psychological health and employee engagement

Psychosocial safety climate (PSC) is defined as shared perceptions of organizational policies, practices and procedures for the protection of worker psychological health and safety, that stem largely from management practices. PSC theory extends the Job Demands–Resources (JD-R) framework and proposes that organizational level PSC determines work conditions and subsequently, psychological health problems and work engagement. Our sample was derived from the Australian Workplace Barometer project and comprised 30 organizations, and 220 employees. As expected, hierarchical linear modeling showed that organizational PSC was negatively associated with workplace bullying and harassment (demands) and in turn psychological health problems (health impairment path). PSC was also positively associated with work rewards (resources) and in turn work engagement (motivational path). Accordingly, we found that PSC triggered both the health impairment and motivational pathways, thus justifying extending the JD-R model in a multilevel way. Further we found that PSC, as an organization-based resource, moderated the positive relationship between bullying/harassment and psychological health problems, and the negative relationship between bullying/harassment and engagement. The findings provide evidence for a multilevel model of PSC as a lead indicator of workplace psychosocial hazards (high demands, low resources), psychological health and employee engagement, and as a potential moderator of psychosocial hazard effects. PSC is therefore an efficient target for primary and secondary intervention.     

Numerical modeling of thermal regimes during the assembly of a multicomponent system

Results are presented from a numerical modeling of the solution of a problem involving optimization of the thermal regime in the assembly of integrated circuits. The modeling was performed on array processors of hybrid computers.Notation T_g gas temperature - heat-transfer coefficient - c_V specific heat capacity - thermal conductivity - time - q heat flux - L internal heat of phase transformations or other internal transformations - c_Ve effective volumetric heat capacity - density - q_V power of internal heat sources Indices g gas - c convection, contact - sp spectral - r radiative - L phase transformation - V volumetric - 0 initial - e environment - liquidus - s solidus - s surface - total Abbreviations R-R resistance circuit - Liebmann method - T Gel'perin method Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 56, No. 5, pp. 793–798, May, 1989.     

Question of the convergence of iteration methods of solving the inverse heat-conduction problem

The convergence of iteration methods of solving the inverse heat-conduction problem depending on the type of desired boundary function is numerically investigated.Notation t time - t_p length of the time interval - x space coordinate - b thickness - T(x, t) temperature - C(T) bulk specific heat of the material - (T) heat conduction coefficient of the material - (x) initial temperature distribution - q thermal flux density - f(t) measured temperature - (x, t) adjoint variable - , , p parameters of the method of conjugate gradients - k number of the iteration Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 45, No. 5, pp. 770–773, November, 1983.     

Analysis of the effect of the decomposition of char-forming heat-insulating materials on the free discharge of a gas mixture

The article presents results of a numerical solution of a nonsteady problem on the free discharge of a mixture of gases from a hemispherical volume with allowance for thermal decomposition of heat-insulating materials.Notation V volume - S area - t - P p - T - u v - Q q, dimensional and dimensionless time, pressure, temperature, TIM decomposition rate, and heat flux - adiabatic exponent - R gas constant - density - H specific enthalpy - c specific heat - thermal conductivity - , , _s dimensionless complexes - coefficient expressing the radiative properties of the gas medium and the heat-transfer surface - Stefan-Boltzmann constant Indices 0 initial state and scale factors - s surface - coke - M TIM material - P pyrolysis front - A ablation front - v volatile degradation products - adiabatic conditions - c completion of discharge Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 54, No. 5, pp. 787–793, May, 1988.     

Application of coherent-optical methods in physical studies of evaporation

The application of the methods of laser and holographic interferometry to the problems of measuring evaporation rates is examined. Mass transfer accompanying evaporation in the region of extradiffusion monitoring is studied.Notation j_v specific mass flux of the vapor, kg/(m²·sec) - _c coefficient of condensation - _v coefficient of evaporation - D coefficient of diffusion - m²/sec, wetting angle - R radius of the vessel, m - time, sec - h height of the segment, m - wavelength of the laser radiation, m - N order of the interference fringe or the number of fringes passing through a given point - density of the matter, kg/m³ - length of the cell with the liquid of interest, m - T temperature, K - n refractive index of the medium - m mass - kg, V volume of the spheroidal segment, m³ - _liq and _g molar mass, kg/mole - C₀ and C_p concentration of vapor in the gas, kg/m³ - a and b semiaxes of the spheroid, m - _e ellipsoidal coordinate of a point on the surface, m² - c/n derivative along the normal - r coordinate of a point on the surface of evaporation, m - n change in the refractive index of the medium Indices st standard liquid - liq liquid - g gas - 0 starting state - p equilibrium pressure Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 55, No. 4, pp. 605–611, October, 1988.     

Volt-ampere characteristics of an ac arc in a transverse gas flow

An analytical dependence of the volt-ampere characteristic of an arc on the velocity of the incoming transverse gas flow is obtained. The stability threshold of arc combustion is determined.Notation h enthalpy - density - t time - v velocity - , thermal conductivity and electrical conductivity - E electric field strength - U potential at the arc - Q radiant flux - T period of oscillation of the current - r radius - l length of electric arc - d, L diameter and length of electrode - temperature - kinematic viscosity - Pr Prandtl number - current function Indices 0 gas parameters far from arc - 1 parameters at arc boundary - x projection on the axis 0x - y projection on the axis 0y - E effective value - e characteristic value Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 47, No. 1, pp. 133–138, July, 1984.     

Effect of nonlinearity of gas mixtures on the process of their partition by thermal diffusion

Under consideration is the effect of nonideality of the components in a gas mixture on the process of their separation by thermal diffusion. It is demonstrated that in the expressions for the heat flux and the mass flux, the thermodiffusion ratio and the characteristic of diffusional thermal conductivity the effect of nonideality appears in the heat of mixing.Notation p pressure - density - length of the mean free path for molecules during transport of particles - length of the mean free path for particles during a transfer of the mean velocity - n molecule concentration - M molecular weight - I particle flux - J mass flux - m mass of a molecule - t time - D_ij coefficient of interdiffusion for a binary mixture - D _i ^T coefficient of thermal diffusion - K_T thermodiffusion ratio - _T thermodiffusion constant - x_i molar fraction of the i-th component in the mixture (r), intermolecular interaction potential - r intermolecular distance - collision integrals - T temperature - T^* referred temperature - R universal gas constant - k Boltzmann constant - Ñ Avogadro's number - v mean velocity of molecules - ¯V diffusion rate - _{i, trans} thermal conductivity associated with translatory degrees of freedom - f_i(r, v, t) velocity distribution function of molecules - viscosity - _i chemical potential of the i-th component - c_i mass fraction - _o thermal conductivity at the initial instant of time - thermal conductivity in the steady state - _DT diffusional component of thermal conductivity - g and h molar thermodynamic functions - ¯g and ¯h specific thermodynamic functions - c_p specific heat - J_q heat flux - J_q reduced heat flux - B second virial coefficient - U^* transport energy - coefficient of thermal expansion - coefficient of isothermal compression - f_i activity coefficient for the i-th mixture component Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 40, No. 5, pp. 829–839, May, 1981.     

Study of entrainment of drops of coolant by wet vapor in a heat-pipe vaporizer

Expressions are obtained to describe the performance of a heat pipe in a regime of wet vapor flow. The analytical results are experimentally confirmed.Notation Q heat flow - q heat flux in the vaporizer - T temperature - P pressure - S surface area - length - r radius - G mass velocity - y mass moisture content - n number of droplets - V volume - N_ca calculated concentration - v axial linear velocity - d diameter - volume moisture content - a inclination of heat pipe - m mass velocity from a unit surface area - F force - w radial velocity - I intensity of beam - K permeability - N parameter - slip coefficient - g gravitational constant - distribution parameter - variance - x, y, z coordinates - C constant - attenuation efficiency factor - friction coefficient - attenuation factor of medium referred to a unit surface area - n=S_d/S_s coefficient of heat-flow transformation - k heattransfer coefficient in the heat-pipe condenser Indices liquid - w wick - hp heat pipe - ef effective value - cap capillary structure - d drop - v vapor - f flow-rate value - s vaporizer - cond condenser - e free-falling - ar arithmetic mean value - a adiabatic zone - b light beam Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 42, No. 1, pp. 11–20, January, 1982.     

The mechanism of adhesion of moist powders to solid surfaces in the presence of a temperature field

An examination is made of the basic factors which influence the creation of forces causing powders to adhere to solid surfaces in the presence of a temperature field. An experimental investigation has been conducted on an apatite concentrate.Notation p_c capillary pressure - density of fluid - g acceleration due to gravity - h_cap, h limiting and actual height of capillary rise - surface tension - r radius of equivalent capillary - q specific suction force - k_w water saturation coefficient - V_w volume of water in pores - V_pore volume of pores - Wg humidity by weight - R particle radius - polar angle - _c area of contact - N total adhesive force - _m, _w specific weight of powder and water     

Thermohydraulic stability of helium flow at supercritical pressure under conditions of forced and mixed convection in a vertical heated channel

The excitation of thermally induced oscillations in low-temperature helium flow in channels with different orientation are studied and the boundaries of stability are constructed.Notation c heat capacity - D diameter - F area of the transverse cross section - G flow rate - Gr_A Grashof number - g acceleration of gravity - h enthalpy - p pressure - perimeter - Re Reynolds number - s complex Laplace transform variable - T temperature - t time - x distance along the channel - thermal conductivity - circular frequency of the pulsations - p specific density - in at the inlet to the channel - out at the outlet from the channel - liq the flow - O in front of the throttle at the channel input - m the pseudocritical temperature - N in front of the throttle at the channel output - w and c the pipe wall Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 55, No. 4, pp. 538–545, October, 1988.