青春

Youth is not a time of life; it is a state of mind; it is not a matter of rosy cheeks, red lips and supple knees; it is a matter of the will, a quality of the imagination, a vigor of the emotions; it is the freshness of the deep springs of life.     

Effects of a flexible joint on instability of a free-free jointed bipartite beam under the follower and transversal forces

This paper deals with the problem of the instability regions of a free-free flexible jointed bipartite beam under the follower and transversal forces as a realistic simulation of a two-stage aerospace structure. The aim of this study is to analyze the effects of the characteristics of a flexible joint on the beam instability to use maximum bearable propulsion force. A parametric study is conducted to investigate the effects of the stiffness and the location of the joint on the critical follower force by the Ritz method and the Newmark method, then to research the vibrational properties of the structure. It has been shown that the nature of instability is quite unpredictable and dependent on the stiffness and the location of the joint. The increase of the follower force or the transversal force will increase the vibration of the model and consequently cause a destructive phenomenon in the control system of the aerospace structure. Furthermore, this paper introduces a new concept of the parametric approach to analyze the characteristics effects of a flexible two-stage aerospace structure joint design.     

E-characteristic polynomials of real rectangular tensor

By the resultant theory, the E-characteristic polynomial of a real rectangular tensor is defined. It is proved that an E-singular value of a real rectangular tensor is always a root of the E-characteristic polynomial. The definition of the regularity of square tensors is generalized to the rectangular tensors, and in the regular case, a root of the E-characteristic polynomial of a special rectangular tensor is an E-singular value of the rectangular tensor. Moreover, the best rank-one approximation of a real partially symmetric rectangular tensor is investigated.     

New Methods in Design Education： The Systemic Methodology and the Use of Sketch in the Conceptual Design Stage

This study describes the application of a new product concurrent design methodologies in the context in the education of industrial design. The use of the sketch has been utilized many times as a tool of creative expression especially in the conceptual design stage, in an intuitive way and a little out of the context of the reality needs that the design should be attended. This methodology systematizes and guides the process of sketching by means of a conceptual model and a geometric model toward a feasible solution, complementing the role of the sketch in the phase of a product conceptual design. The model describes its operating principles, as well as the phases of implementation in the context of teaching the industrial design illustrated with projects carried out in the workshop of conceptual design of the University Technical College of Valencia and University of the Bio-Bio, Chile. Finally, we discuss the implementation of the systemic models, their relation with the optimisation of the sketching process in the conceptual design stage, and their implications in the educational context.     

Dynamic response of a beam on a Pasternak foundation and under a moving load

The dynamic response of an infinite beam placed on a Pasternak foundation when the system was subjected to a moving load was investigated. We used the double Fourier transform and its inversion to solve the formulations of the problem. A closed form analytic solution of the beam was obtained by the theorem of residues. We selected a numerical example to illustrate the dynamic response of the beam on Pasternak and Winkler foundations, respectively. We discuss the effect of the moving load velocity on the dynamic displacement response of the beam. The maximum deflection of the beam increases slightly with increased load velocity but increases significantly with reduced shear modulus of subgrade at a given velocity. The maximum deflection of a beam resting on a Pasternak foundation is much smaller than that of a beam on a Winkler foundation.     

Solution of a rigid disk on saturated soil considering consolidation and rheology

INTRODUCTION An important problem in foundation engineeringis the determination of the rate of settlement of a raftfoundation placed on a deep clay layer. Gibson andMcNamee (1957), and McNamee and Gibson (1960a;1960b) considered the problem of normal uniformloading applied to the surface of a half-space andshowed that one-dimensional theory gives a markedunderestimate of the rate of settlement. This theorycorresponds to the case of a perfectly flexible footing.However, it is often…     

青春寄语

Youth is not a time of life; it is a state of mind; it is not a matter of rosycheeks, red lips and supple(柔韧的)knees; it is a matter of will, a quality of imagination, a vigor of the emotions; it is the freshness of the deep springs of life.Youth means a temperamental predominance(支配,主导)of courage over timidity(胆怯),of the appetite for adventure over the love of ease. This often exists in a man of 60 more than a boy of 20. Nobody grows old merely by a number of     

Aesthetic Processing for Theatre Translation

Theatre translation is one of the most neglected areas in the field of translation.Theatre is a special member of the literature family in that it doubles as a branch of the performing art.It follows that the aesthetic constitutions of a dramatic creation is a complex problem. It is the translator’s duty to grasp the artistic features of the literary creation and reproduce them in the version since the most important thing in a piece of literature is its artistic features.     

A Book Report on Psychology of Language

This paper is a book report of "Psychology of Language",a book on the field of psycholinguistics written by Carroll,a professor of University of Wiscosin-Superior.In this book report,besides a general summary of the development of psycholinguistics and an introduction of the content of this book,my personal interest in the field of psycholinguistics is also stated,that is,the in-fluence of the syntactic structure upon language comprehension     

阅读理解五篇

A A ride in a cable-car is one of the most exciting and enjoyable experiences a child can have. In Switzerland, which is the home of the cable-car, it is used mostly to take tourists up the slope of a mountain, to a restaurant from which one can have a bird's-eye view of the surrounding country, or to the top of ski-run, from which, in winter, skiers glide down the snow-cov- ered slope on skis, in Singapore, however, the cable-car takes one from the summit of a hill on the main island     

Analysis of My Fair Lady from the Perspective of Sociolinguistics

My Fair Lady is a movie about how a poor flower girl is turned into a graceful lady by changing the language she speaks with the help of a linguist.It demonstrates the great influence that language exerts on a person’s experience.This paper tries to analyze the movie from the perspective of sociolinguistics,especially the language variations caused by region,class,and gender difference,with the aim of helping the reader to have a better understanding of the movie and displaying the charm of language.     

English Noun Inflections in Different Periods

One of the distinguishing featuros of English is its inflections, which experiencedchanges in the different periods. Old English is known as a language of full Inflections,Middle English as a language of leveling inflections and Modern English as a language oflost inflections. The history of English is in part the history of the gradual loss of the inflection system.Definition of inflectionInflection is the process of varying the form of a word to differentiate related meanings or uses. Fo…     

Finite element study on impact sound transmission through a floating floor

To understand the characteristics of impact-sound transmission through a floor is very helpful for developing sound attenuation strategies to acquire a high quality of dwellings. Sound transmission through a floating floor to the room underneath was modeled by finite-element method (FEM). The sound pressure levels calculated by the FEM model on a scale of 1:4 was compared with the measured values, which demonstrate good agreement, particularly for impact sound of a relatively low frequency. The sound pressure level in a receiving room is strongly affected by the structural characteristics of both the floor and the room. The sound pressure transmitted through a clamped floor is lower than through a simply supported floor because of the larger rigidity of the clamped floor that contributes to the attenuation mechanism of stiffness. Increase in the thickness of the fiber-glass damping layer in the floor improves sound insulation. A larger room has a larger capacity to dissipate the sound pressure and thus has a lower sound pressure level. An asymmetric configuration of room avails sound attenuation because it has weaker structural and acoustic coupling than a symmetric one.     

准轴对称陀螺体自激运动的平均化分析

The averaging analysis was carried out to study the motion of a quasi-axisymmetrical gyrostat under a small-magnitude self-excited control troque.The common approach to investigating the problem of rigid body rotatyion under the action of a small torque known in the body frame was described.Using this approach,the problem(Grammel‘s problem for the case of small torque) that is maintaining the angular velocity of a quasi-axisymmetrical gyrostat using a control torque quadratic in the angular velocity was solved.Maintaining the angular velocity of a quasi-axisymmetrical gryostat using a control torque quadratic in the angular velocity was solved.     

Earth return path impedances of underground cable for three-layer earth

One of the factors that affect the parameters of an underground cable is earth return path impedance. Pollaczek developed a formula for the case of one-layer （homogenous） earth. But in practice the earth is composed of several layers. In this study we develop a new formula for earth return path impedance in the case of a three-layer earth. To check the accuracy of the obtained results, a comparison has been made with the finite element method （FEM）. A comparison between the results of the Pollaczek formula and results of the obtained formula for a three-layer earth has been made, showing that the use of the Pollaczek formula instead of the actual formula can cause serious errors.     

What Was the Riddle of the Sphinx？

The Sphinx was a make-belive animal of long ago.It had the head of a person, the body of a lion,and the wings of a bird.The Sphinx lived near a city called Thebes.     

向量与数的乘法

Vectors may also be multiplied by a number. The productof the vector a by the number λ is defined as the vector a λ=λa, the absolute value of which is obtained by multiplying theabsolute value of the vector a by the absolute value of thenumber λ, i. e. |λa|=|λ||a|, the direction coinciding withthe direction of the vector a or being in the opposite sensedepending on whether λ>0 or λ<0. If λ=0 or a=0, then λ a     

Kantorovich’s theorem for Newton’s method on Lie groups

The convergence criterion of Newton’s method to find the zeros of a map f from a Lie group to its corresponding Lie algebra is established under the assumption that f satisfies the classical Lipschitz condition, and that the radius of convergence ball is also obtained. Furthermore, the radii of the uniqueness balls of the zeros of f are estimated. Owren and Welfert (2000) stated that if the initial point is close sufficiently to a zero of f, then Newton’s method on Lie group converges to the zero; while this paper provides a Kantorovich’s criterion for the convergence of Newton’s method, not requiring the existence of a zero as a priori.     

A Hidden Color of Spring

Blue is the sky that finally appeared behind a winter of gray。Blue is the silhouette of a bird soaring high in the sky. Blue is the pedals of a newborn flower. Blue is the current of a rushing stream freed from the cold. Blue is the broken shells that revealed the world to twittering robins.     

利用小角度近似测定水的折射率

Measurement of the index of refraction has longbeen a standard experiment in the introductory labora-tory.We have developed a variation of this experimentthatrequires only a series of length measurements andutilizes the small- angle approximation.It is a simplealternative to the more conventional laboratory exer-cise in which,for example,one uses a ruler and pro-tractor to measure the angles at which a ray entersand leaves a block of glass.Our method typically givesa refractive index of water …