Fe-based metallic glasses(MGs) with excellent soft magnetic properties are applicable in a wide range of electronic industry. We show that the cryogenic thermal cycle has a sensitive effect on soft magnetic properties of Fe_(78)Si_9B_(13) glassy ribbon. The values of magnetic induction(or magnetic flux density) B and H_c coercivity c show fluctuation with increasing number of thermal cycles. This phenomenon is explained as thermal-cycle-induced stochastically structural aging or rejuvenation which randomly fluctuates magnetic anisotropy and, consequently, the magnetic induction and coercivity. Overall,increasing the number of thermal cycles improves the soft magnetic properties of the ribbon. The results could help understand the relationship between relaxation and magnetic property, and the thermal cycle could provide an effective approach to improving performances of metallic glasses in industry. 相似文献
The solubilities of solid pentane, 2-methylbutane (isopentane), and cyclopentane in liquid argon at 87.3 K have been measured by the filtration method. The C5 hydrocarbon content in solution was determined using gas chromatography. The solubilities of the C5 hydrocarbons in liquid argon at 87.3K vary from 0.61 × 10–7 mole fraction for cyclopentane, to 1.37 × 10–7 mole fraction for pentane, and 8.83 × 10–6 mole fraction for 2-methylbutane. The Preston–Prausnitz method was used for calculation of the solubilities of solid C5 hydrocarbons in liquid argon in the temperature range 84–110 K and in liquid nitrogen in the range 64–90K. The values of the solvent–solute interaction constant l12 were also calculated. 相似文献
Comprehensive gas chromatography is the realization of true continuous multidimensional (dual column) gas chromatography. The key requirement in the comprehensive GC experiment is that the second dimension analysis is completed in a rapid time‐frame compared to the elution of components in the first dimension, and that the two coupled dimensions represent ‘orthogonal’ analyses towards the analytes to be separated. The former normally necessitates pulsing of contiguous segments of each chromatographic band from the first to the second dimensions. The two dimensions should be in fluid communication. The comprehensive GC×GC experiment passes all the column flow from the first column to the second column, leading to no sample loss, but this also requires a suitable method for time‐ or zone‐compression of the band to be pulsed to the second column. The final pulse should be narrow, and should be delivered to the second column quickly. A simple procedure can achieve this using the cryogenic modulator that has been recently described by this group. The system uses a cryogenic trap which can be moved away from the cooled zone of the column faster than 10 ms. A fast‐acting pneumatic ram achieves this performance. The cooled column heats up to the prevailing oven temperature within 10–15 ms. Molecules as volatile as C5 alkanes or small aromatics will be fully retained by the trap within the period of modulation used for GC×GC. The technique is simple to implement and requires no special column connections. Using a gas chromatograph which allows control of external events and can acquire from a detector at 50 Hz or faster, and a timing controller for modulation, the comprehensive result can easily and effectively be achieved. 相似文献
A new procedure for obtaining density-dependent mixing rules is applied to the Soave-Redlich-Kwong equation of state. The result is a one-parameter local-composition mixing rule which adequately represents the nonidealities possible in dense fluid mixtures but approaches the classical mixing rule at low densities. A three-parameter version of the mixing rule is also presented which allows for the local-composition effect in the low density limit. The expressions are tested with the Soave-Redlich-Kwong equation of state. Results for vapor-liquid and gas-liquid systems are discussed. 相似文献
The gyrotron system forECH and burn control onITER requires at least50MW ofRF power at frequencies near170GHz operating inCW. To meet these requirements, high efficiency gyrotron tubes with 1MW power output capability are necessary, as well as simple coupling to either a quasi-optical or waveguide transmission line. The paper reports the feasibility study on the design of anITER-relevant gyrotron oscillator at170GHz,1MW CW employing a diode electron gun, an advanced internal quasi-optical converter, a cryogenically cooled single disk sapphire window, and a depressed potential collector. The operating mode selection and the cavity design is a compromise between many design constraints. 相似文献
Gow, A.S., 1993. A modified Clausius equation of state for calculation of multicomponent refrigerant vapor-liquid equilibria. Fluid Phase Equilibria, 90: 219-249.
A modified Clausius equation of state with a single temperature dependent energy-volume parameter a(T) in the attractive term was designed to describe the vapor pressure vs. temperature relationship of 39 pure refrigerant fluids including elementary cryogenic materials (e.g. He, Ar, N2, CO2, CH4, etc.), chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFCs), fluorocarbons (FCs), and various other simple cryogenic compounds. The equation developed represents the vapor-liquid coexistence dome, and the superheated vapor compressibility factor and enthalpy for pure refrigerants.
The vapor-liquid equilibrium for refrigerant mixtures is calculated using a “phi-phi” method with “one fluid” van der Waals mixing and combining rules for the equation of state parameters aM(T), bM and cM. A single interaction constant k12 is used to describe non-ideal behavior of each binary. The binary interaction constant, which is a strong function of temperature, and the sign of which signifies the type of deviations from Raoult's law, is obtained by correlating experimental bubble point data for isothermal binary refrigerant mixtures. The proposed equation of state generally describes binary P-x,y data more accurately the higher the temperature for a given system. The method presented is extended to predict vapor-liquid equilibria for the R14-R23-R13 ternary system at 198.75 K using binary interaction constants at this temperature for the three binaries involved. 相似文献
The solubilities of solid 1-hexyne in liquid argon at 87.3 and in liquid nitrogen at 77.4 K have been measured by the filtration method. The hydrocarbon contents in solutions were determined using gas chromatography. GC–MS was used to identify impurities in 1-hexyne. The experimental value of the mole fraction solubility of solid 1-hexyne in liquid argon at 87.3 K is (0.85 ± 0.19) × 10–7 and (1.25 ± 0.08) × 10–8 in liquid nitrogen at 77.4 K. The Preston–Prausnitz method was used for calculation of the solubilities of solid hydrocarbon in liquid argon in the temperature range 84.0–110.0 K and in liquid nitrogen from 64.0 to 90.0 K. The solvent–solute interaction parameters l12 were also calculated. At 90.0 K liquid argon is a better solvent for solid 1-hexyne than is liquid nitrogen. 相似文献
The solubilities of 1-pentene ice in liquid nitrogen at a temperature of 77.4 K and in liquid argon at 87.3 K have been measured by the filtration method. The 1-pentene content in solution was determined using gas chromatography. The experimental value of the mole fraction solubility of 1-pentene ice in liquid nitrogen at 77.4 K is: (1.28±0.25)×10–7 and (4.11±0.44)×10–7 in liquid argon at 87.3 K. The Preston–Prausnitz method was used for calculation of the solubilities of 1-pentene ice in liquid nitrogen in the temperature range 64.0–90.0 K and in liquid argon in the temperature range 84.0–90.0 K. The parameters l12 were also calculated. At 90.0 K liquid argon is the better solvent for 1-pentene ice than is liquid nitrogen. 相似文献