Cogito ,as the first principle of Descartes’metaphysical system, opens modern philosophy ofconsciousness and becomes modern and contemporary western philosophical discourse’s sources and objectof discussion.

Arbitrariness,which was proposed as the first principle of language by Saussure,father of the modern linguistics,contributes to the versatility and flexibility of language.

During the course of design and realization,the first principle is to protect users' investment and reduce the cost while designing Distributed Information Release System.

To establish a Principal form in the historic characters , the first Principle is the social circulation, and the second is the systematic nature, if necessary, with reference to the motivation of character, the standing of the historic forms in dynastic dictionaries.

The principle of virtual power here is so formulated that, when combined, forreal velocity fields, with the first principle of thermodynamics in global form, it yields directly the socalled energy theorem both in the bulk and at the singular surface.

Due to the complexity and highly nonlinearity of the process, the modeling of the process based on the first principle is difficult and involve too many unknown parameters.

The safety first principle and capital market equilibrium

As a first principle, I assume that in any decision-making situation in which organisational leaders must choose between their own welfare and the welfare of their employees, they will almost always select the selfish course of action.

The first principle, "method noise", specifies that only noise must be removed from an image.

The so-called "truss rigid frames" are those rigid frames with trusses as their horizontal beams, of which the two ends are rigidly connected to columns. Within the author's knowledge, all the methods available at present for analyzing such rigid frames are based on Certain special assumptions such as (1) that the positions of the points of contra-flexure in all the columns are previously known; (2) that the end rotations of a truss may be reprensented by that of its assumed line of axis as in the case of an...

The so-called "truss rigid frames" are those rigid frames with trusses as their horizontal beams, of which the two ends are rigidly connected to columns. Within the author's knowledge, all the methods available at present for analyzing such rigid frames are based on Certain special assumptions such as (1) that the positions of the points of contra-flexure in all the columns are previously known; (2) that the end rotations of a truss may be reprensented by that of its assumed line of axis as in the case of an ordinary beam; or (3) that the end verticals of trusses may be given certain prescribed deformations. Of course, the adoption of any of such assumptions leads to only approximate results inconsistent with the actual deformations of such rigid frames under any loading. Heretofore, the author did not know any correct method for analyzing such rigid frames. In this paper, the author presents two principles of the correct analysis of truss rigid frames. The first principle is that of "moment action on column" for computing the angle change constants of columns, and the second principle is that of "effect of span-change in truss" for computing the angle and span change constants of trusses.As, for computing the angle change constants of a truss, the dummy unit moment is a couple applied to its end verticals, so, for computing the angle change constants of a column, the dummy unit moment must also be a couple applied to the section of column rigidly connected to the end of a truss, in order to effect a consistent deformation at the joint of the two. This is the first principle.A truss just like a curved or gabled beam of which the effect of span-change can not be neglected, so truss rigid frames belong to the same category of what may be called "span-change" rigid frames such as rigid frames with curved or gabled beams. Therefore the span-change constants of trusses should be included besides their angle-change constants for analyzing truss rigid frames. This is the second principle.With the constants of columns and trusses are all computed in accordance with respectively the first and second principles mentioned above, truss rigid frames may be analyzed by any method including the effect of span-change as in the case of rigid frames with curved or gabled beams, and the results thus obtained will be exactly the same as by the method of least work or deflections without any special assumptions.In this paper, after the two principles are described and the formulas for computing the constants of columns and trusses are derived, the correctness of the two principles are then proved by the methods of least work, deflections and slope-deflection. A two-span truss rigid frame is analyzed under the following three conditions:Ⅰ. Applying both of the two principles to obtain the correct results.Ⅱ. Applying only the first principle to show the discrepancies of neglecting the effect of span-change in trusses as born out by comparing the results of Ⅱ with Ⅰ.Ⅲ. Applying neither of the two principles, and the truss rigid frames being analyzed by the special assumption (2) mentioned above with the line of axis at the bottom chord of truss, in order to show the discrepancies of neglecting the moment action on column as born out by comparing the results of Ⅲ with Ⅱ. For the sake of brevity, only the results are given in Tables 1 to 5 without computations in details.Although the discrepancies of neglecting the moment acticn on column are only slight as shown by comparing the results of Ⅲ with Ⅱ in Tables 2, 4 and 5, there is no reason why special assumptions should not be replaced by the correct principle of moment action on column to obtain correct results. As shown by comparing the results of Ⅱ with Ⅰ in Tables 2, 4 and 5, the discrepancies by neglecting the span change in trusses are generally considerable and, in certain particular part, as large as 3000%. Therefore, for the safe and economical design of truss rigid frames, the effect of span-change in trusses should not be neglected in their analysis.Finally, for analyzing co

The blade (lug) of a blade-wheel is the basic element to interact with the soil. The driving profile of a double-curved-profile blade is the profile to obtain thrust and lift characteristics. It's geometrical parameters have highly significant effect on the mobility performance of the rigid wheel at wet paddy field.In order to develop and to design the geometrical parameters of the driving profile, there are two fundamental principles that must be kept in mind. The first principle is the fundamental law...

The blade (lug) of a blade-wheel is the basic element to interact with the soil. The driving profile of a double-curved-profile blade is the profile to obtain thrust and lift characteristics. It's geometrical parameters have highly significant effect on the mobility performance of the rigid wheel at wet paddy field.In order to develop and to design the geometrical parameters of the driving profile, there are two fundamental principles that must be kept in mind. The first principle is the fundamental law of conjugate action between two meshing profiles, when two profiles are designed to produce a constant angular velocity ratio during meshing, they are said to have conjugate action. In order to transmit motion at a constant angular velocity ratio, the pitch point P must remain fixed, and the line of action must remain intersected the horizontal line at a constant pressure angle. The second principle is that the rolling motion and locus of any point of a slipping wheel must be used in developing the parameters of a blade.The rate of slip of a slipping driving wheel is the main parameter which relates with all other geometric parameters of blades. It acts some thing like the 'module m' of a gear profile.This paper analyses and deals with nine geometrical parameters of the driving profile of a blade. Those are.Top circle pitch circleBase circle Inclined anglePressure angle Radial height of profileContact length Arc length of profileRolling wheel angle within meshing The author derives the following equations to relate the nine parameters.1 . Rate of slip 5 and radius of pitch circle r, radius of top circle2 . The inclined angle (y) equation 0=1- ^-HULjSY-.3. The pressure angle (a) equationcos (tga) -tgasin (tga)b _ jTo compute the above two equations, the author develops his program using the Programmable casio fx-1 calculator, and obtains the value y and a with respect to 6, and plots the curves of the above equations. The curves intersect at a point which represents optimum value of inclined angle and pressure angle with respect to the rate of slip (y = a = 26.5%, o=14.87%) .4 . Radius of base circle (rg)rg = rcoscc = r0 (1-5) cosacos (tga) -tgasin (tga) = r0 -------- ------------- cosa5. The radial height (h)h"=r0 (1 -5) ( 1 -cosa) 6 . The arc length of profile (s) s= -i-rgtg2a0r20 sin2a 2rg7. Contact length (L)L = r0sina8. The rolling wheel angle within meshing? - L ro sina , 昬A + eA2=-^ + Y = - - - + Yrs rgFor a blade profile with 26.51? inclined angle and pressure angle, the rolling angle of wheel within meshing is 60. 08? and thus the minimum blades in one wheel are six. Six blades are sufficient to assure that there is always a blade in meshing with the soil.This paper lists out three tables of tractor test data which reveal the performance of 30? inclined angle blade wheel mounted on wheel tractors, riding tractors, and boat-type tractors. The data shows that the tractive efficiency of these three kinds of tractors with blade wheels are 48-54%, but for other wheels they are 10-43%.The author designs the optimum geometrical parameters of 26.50?blade wheels and compares them with the parameters of the 30癰lade wheels.The author hopes that the advanced theoretical study of the driving profile of a blade will give the tractor more tractive efficiency,and thus increasing the tractor's pull and obtaining the higher fuel efficiency. The fuel saving will give from 5 to 9 % for the paddy field wheel tractors.

Solid state physicists witnessed notable progress in single electron energy band theories during the past decade. It is now possible to compare informations from sophisticated experimental measurements, with not only energy band structure but also various physical expectation values that can be calculated with energy eigenfunctions. The local density functional theory initiated by Hohenberg, Kohn and Sham, aiming at supplying a rigorous basis for single particle energy band description of ground state properties,...

Solid state physicists witnessed notable progress in single electron energy band theories during the past decade. It is now possible to compare informations from sophisticated experimental measurements, with not only energy band structure but also various physical expectation values that can be calculated with energy eigenfunctions. The local density functional theory initiated by Hohenberg, Kohn and Sham, aiming at supplying a rigorous basis for single particle energy band description of ground state properties, also provides accurate and practical methods of calculation starting from first principles. The present article is a review on recent progress of Local Density Functional (LDF) theory——energy band methods. We first give a general introduction to the theoretical background and then show the readers their successes through discussions of applications to various physical systems.