This paper points out that the equal sign("=")in the structural formulas of the main transmission Chain in machine tools is unaccountale, and suggests that the sign be replaced by a special symbol" (?)

Space between Si flakes increased,then decreased as the change of intension of magnetic field from 0 T to 0.15 T with the tow-rate of R equal to 20 μm/s,50 μm/s,100 μm/s,200 μm/s respactively.

Experiments show that the cooling efficiency η is equal to or larger than 83%, and the temperature of sand at the outlet is less man 40℃,with inlet sand temperature≈80℃-90℃,the productivity Qs equals to 5 t/(h.m width of sand cascade.)

It is well-known that the ring of invariants associated to a non-modular representation of a finite group is Cohen-Macaulay and hence has depth equal to the dimension of the representation.

The essential dimension is a numerical invariant of the group; it is often equal to the minimal number of independent parameters required to describe all algebraic objects of a certain type.

We also give conditions for the two algebras to be equal, relating equality to good filtrations and saturated subgroups.

We present two generalizations of the orthogonal basis of Malvar and Coifman-Meyer: biorthogonal and equal parity bases.

An important property of this matrix is that the maximum and minimum eigenvalues are equal (in some sense) to the upper and lower frame bounds.

A spectrographic procedure for determining copper in concentrated iron ores has been worked out for routine analysis. The powder method is found to be satisfactory with a medium quartz spectrograph and an activated a. c. arc between carbon electrodes as light source. In order to minimize erratic burning of the sample, the electrodes are pre-burned for one minute and then loaded with a mixture of equal weight of the ore sample and carbon powder. The analysis pair of lines chosen are: Cu 2824.369- Fe 2824.67...

A spectrographic procedure for determining copper in concentrated iron ores has been worked out for routine analysis. The powder method is found to be satisfactory with a medium quartz spectrograph and an activated a. c. arc between carbon electrodes as light source. In order to minimize erratic burning of the sample, the electrodes are pre-burned for one minute and then loaded with a mixture of equal weight of the ore sample and carbon powder. The analysis pair of lines chosen are: Cu 2824.369- Fe 2824.67 for copper contents ranging from 0.05 to 0.3%, and Cu 2824369- Fe 2828.813 for those between 0.3 and 1.0%. The results obtained spectrographically have been checked by wet chemical analysis, amongst 110 samples 80% of which the two methods checked within 0.02%.

The purpose of this series is to make a thermodynamic analysis of the Fe-C system with a minimum of assumptions and to revise the equilibrium diagram of the same system in the light of the results of this investigation. In this paper, the first of the series, activities in liquid Fe-C alloys have been evaluated up to saturation, using Richardson and Dennis' data123 on dilute solutions of carbon in liquid iron and Darken and Smith's model~([1]) for carbon dissolved in austenite with certain modifications.A parameter...

The purpose of this series is to make a thermodynamic analysis of the Fe-C system with a minimum of assumptions and to revise the equilibrium diagram of the same system in the light of the results of this investigation. In this paper, the first of the series, activities in liquid Fe-C alloys have been evaluated up to saturation, using Richardson and Dennis' data123 on dilute solutions of carbon in liquid iron and Darken and Smith's model~([1]) for carbon dissolved in austenite with certain modifications.A parameter α_c defined as logγc/N_Fe~2 with reference to graphite as the standard state is plotted against N_c for both austenite and Fe-C melt in order to facilitate the evaluation of α_(Fe) by graphical integration. Smith's data~([1]) on equilibrium between austenite and gaseous mixtures (CO_2/CO, CH_4/H_2) are re-treated to yield α_c~γ-N_c~γ curves for 800° and 1000℃ as shown in Fig. 1. On the assumption that L_c~γ the relative partial molal enthalpy of carbon in austenite, does not chan preciably with temperature, the α_c~γ-V_c~γ curve for 1153℃, the iron-graphite eutectic temperature, is obtained by extrapolation and found to lie above the graphite saturation point. This fact seems to indicate that the limit of application of Darken and Smith's model is reached somewhere around N_c~γ=0.0661 (1.50%) and a point of inflection should occur at this concentration. The above-mentioned assumption has been semi-quantitatively proved in this paper and will be discussed further in another paper of this series.In a similar manner, α_c~l-N_c~l curves for liquid Fe-C alloys are drawn through the experimental points of Richardson and Dennis on equilibrium between CO_2/CO mixed gases and dilute solutions of carbon in liquid iron at 1560° and 1660℃ as shown in Fig. 1. The curves are extended up to N_c~1=0.15 on the basis of Darken and Smith's model using 3600 cals. as the energy of interaction at 1560℃ between carbon atoms in the neighbouring interstitial sites as recommended by Richardson and Dens. Then, a suitable curve is drawn between N_c~l=0.15 and the graphite saturation point for 1560℃ to meet certain requirements, and a corresponding curve for 1660℃ is obtained by extrapolation, assuming that L_c~l, the relative partial molal enthalpy of carbon in liquid iron, does not change appreciably with temperature. Thus, α_c~l-N_c~l curves for 1560° and 1660℃ are completed from low carbon concentrations up to saturation. The activities of carbon in Fe-C melts at 1600℃ with reference to graphite as the standard state are readily obtained at different carbon concentrations by interpolation, from which the reversible electromotive forces of a concentration cell of the type Fe,C|slag, C_2~2|Fe,C(sat.) have been calculated and found to agree fairly well with the experimental values obtained by and as shown in Fig. 2. This agreement may be taken as partial confirmation of the choice of N_c~l=0.15 as the limit of application of Darken and Smith's model to liquid Fe-C alloys.From α_c~l-N_c~l curves for 160°and 1660℃, L_c~l is easily calculated to be 3930 cals., and by combining this value with certain other data, the following equation is obtained:C(gr.)=C[%]; AF°=3930-9.21 T,which differs considerably from Chipman's equation AF°=8900-12.10T given in the 1951 edition of the "Basic Open Hearth Steelmaking". It is believed that the present author's equation is more reliable than Chipman's in view of the uncertainties involved in the derivation of the latter especially regarding the evaluation of the enthalpy of solution of graphite in liquid iron.By graphical integration of the Gibbs-Duhem equation, the activities of iron in Fe-C melts with pure liquid iron as the standard state are obtained at different carbon concentrations and plotted against N_c~l in Fig. 3. The α_(Fe)~l-N_c~l curve thus obtained is independent of temperature. With the aid of Fig. 3 and certain other data, the activities of iron in an Fe-C melt and austenite both saturated with graphite at the eutectic temperature are evaluated with pure γ iron as the common standard state and found to be practically equal as required by the eutectic equilibrium. This fact renders additional support to the choice of N_c~l=0.15 as the inflection point of the α_c~l-N_c~l curves.The shape of the α_c~l-N_c~l curves is briefly discussed from a structural viewpoint.

This is the first of a series of papers with a view to evaluation activities inliquid blast-furnace-type slags.The purpose of this paper is to present new results of calculation for activities of CaO and SiO_2 in liquid CaO-SiO_2,CaO-SiO_2-Al_2O_3 and CaO-MgO-SiO_2-Al_2O_3 systems from existing chemical and electrochemi-caldata with certain assumptions The activities of CaO in the above-mentionedsystems with reference to solid CaO as the standard state are plotted against(%CaO)/(%SiO_2).From a comparison of...

This is the first of a series of papers with a view to evaluation activities inliquid blast-furnace-type slags.The purpose of this paper is to present new results of calculation for activities of CaO and SiO_2 in liquid CaO-SiO_2,CaO-SiO_2-Al_2O_3 and CaO-MgO-SiO_2-Al_2O_3 systems from existing chemical and electrochemi-caldata with certain assumptions The activities of CaO in the above-mentionedsystems with reference to solid CaO as the standard state are plotted against(%CaO)/(%SiO_2).From a comparison of these ~αCaO-(%CaO)/(%SiO_2)curves,a new expression for basicity has been proposed instead of the simple(%CaO)/(%SiO_2)ratio.The activities of CaO in the various systems concerned becomeapproximately equal at the same basicity when the latter is calculated accordingto the new formula.Alumina shows amphoteric behaviour in the new basicityformula in agreement with the general pattern of slag constitution.