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     

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.     

The Song of the River

You hear it all along the river. You hear it, loud and strong, from the rowers as they urge the junk with its high stern, the mast lashed alongside, down the swift running stream. You hear it from the trackers, a more breathless chant, as they pull desperately against the current, half a dozen of them perhaps if they are taking up a wupan, a couple of hundred if they are hauling a splendid junk, its square sail set, over a rapid. On the junk a man stands amidships beating a drum incessantly to…     

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     

Dynamic Analysis of Structural Columns Subjected to Impulsive Loading

For a building structure subjected to impulsive loading, particularly shock and impact loading , the response of the critical columns is crucial to the behaviour of the entire system during and after the blast loading phase. Therefore, an appropriate evaluation of the column response and damage under short-duration impulsive loading is important in a comprehensive assessment of the performance of a building system. This paper reports a dynamic analysis approach for the response of RC columns subjected to impulsive loading. Considering that the dynamic response of a column in a frame structure can also be affected by the floor movement which relates to the global vibration of the frame system, a generic column-mass model is used, in which a concentrated mass is attached to the column top to simulate the effect of a global vibration. To take into account the high shear effect under impulsive load, the model is formulated using Timoshenko beam theory, and three main nonlinear mechanisms are considered. Two typical scenarios, one under a direct air blast loading, and another under a blast-induced ground excitation, are analyzed and the primary response features are highlighted.     

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.     

Numerical computations of the flow in a finite diverging channel

The flow in a finite diverging channel opening into a large space and resembling the experimental prototype of Putkaradze and Vorobieff （2006） was numerically investigated. The effects of the Reynolds number, initial condition, intersection angle, length of the wedge edges, and the outer boundary condition were examined. The numerical results showed that the flow in the wedge undergoes a change from symmetrical flow to unsymmetrical flow with a weak backflow, then a vortical （circulation） flow and finally an unsteady jet flow as the Reynolds number is increased for an intersection angle of 32° and a wedge edge of length 30 times the width of the inlet slit. For the unsteady flow, the jet attached to one side of the wedge constantly loses stability and rolls up into a mushroom-shaped vortex-pair near the outlet of the wedge. As the intersection angle is increased to 50°, a stable jet flow is observed as a new regime between the vortex and unsteady regimes. Both the intersection angle and the wedge length have negative effects on the stability of the flow, although the effect of the wedge length on the critical Reynolds number for the symmetry-breaking instability is not pronounced. The outer boundary condition was found not to affect the flow patterns inside the wedge significantly. At a certain Re regime above the onset of symmetry-breaking instability, the flows evolve into steady state very slowly except for the initial stage in the case of decreasing flow flux. Two different solutions can be observed within the normal observation time for the experiment, providing a possible explanation for the hysteresis phenomenon in the experiment.     

Proving Inequalities

Proving inequalities means to establish that theinequality holds true for arbitrary admissible valuesof the parameters.Example 1:Prove that the absolute value of asum does not exceed the sum of the absolute values:|a+b|≤|a|+|b|.①Proof.The absolute value of the sum |a+b| isequal to a+b or to -(a+b).From the definition ofthe absolute value we havea≤|a|,b≤|b|and combining these inequalities termwise,we geta+b≤|a|+|b|.②In exactly the same manner,-a≤|a|,-b<|b| and-(a+b)≤|a|+|b|.③From the inequalities ②,③ and the definition of the     

语言体系、人类思维以及语言习得

In the following 3 discussions, the writer tries to show that the Chinese language affects the English language just as one sub-system affects another one within the same system, that a language is a shell of a certain thinking, and that the affection between 2 lunguages is actually the affection between 2 modes of thinking; the writer also suggests a way to understand and accept a thinking,and promote one's learning of the language by the accepted thinking.     

中考冠词专项精练(英文)

1.This is song I’ve told you about.Isn’t it beautiful one?A.the;the B.a;aC.the;a D.a;the2.There is book on the desk.It is interesting book.A.a;a B.a;theC.a;an D.the;the3.Jim likes to play football and w as on school team.A./;theB./;/C.the;the D.a;a4.This m orning I had egg and a bottleof m ilk for m y breakfast.A.anB.a C.the D./5.—W hat’s the m atter with you?—I caught bad cold and had to stay in bed.A.a;/B.a;the C.a;a D.the;the6.sun is bigger than earth.A.A;the B.A;anC.The;a…     

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.     

The Altruistic Barber

A barber gave a haircut to a priest one day.When the priest tried to pay for the haircut,the barber refused,saying:"You do God's work."The next morning the barber found a dozen bibles at the door to his shop. A policeman came to the barber for a haircut,and again the barber refused payment,saying:"You protect the public."The next morning the barber found a dozen doughnuts at the door to his shop. A lawyer came to the barber for a haircut,and again the barber refused payment,saying:"You serve…     

童话(英文)

A crow and a fox Once upon a time, a crow and her children lived at the top of a tree and a fox lived in the hole under the tree. One day the crow found a piece of meat. Holding it in her mouth, she flied back home. As the hungry fox saw this, he     

冠词专练(英文)

1. Wouldn1t it be wonderful world if all nations lived in peace with one another? A. a,× B. the,× C. a,the D. the,theA S c h o o l G a r d e n O f E n g l i s h 中 学 英 语 园 地 2 0 0 7 . 7 - 8 2. Mum was sitting on chair near door when I came back. A. the,a B. a,a C. a,the D. the,the 3. Xi相似文献   

Analysis of Second-Order Effect in Frame

The second-order effect is the interaction between the vertical load and the deformation in a vertically forced element. In order to deduce a more brief but practical method, which has considered the second-order effect in a sway frame, some factors which affect the second-order deformation in a sway frame should be generalized based on a more accurate method. Nonlinear finite element is adopted in this paper, and according to this theory, a program, which can calculate the inner force and the deformation of the sway frame considering the second-order effects is coded.     

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.     

有感美国枪械法改革

Some time ago, really, let me be more precise, many years ago, I went for a job interview. Halfway through the interview, one of the interviewers asked me a question,“lf someone robs his victim using a gun with a bullet in it, should he be punished more severely than if he uses a gun that does not have a bullet in it? "What's the difference?"I got a quick response for that one. lsn't it true that if a person robs a victim with a gun, only the robber knows whether or not the gun is loaded, but the victim has no way of knowing it?The gun is used to threaten the victim into submission, and a crime is committed. Why should there be a difference between the sen-tence of a person committing robbery with a gun that has an empty chamber and a person robbing while holding a gun with a bullet in it? Of course I didn't get the job - I guess I didn't need a job then anyway.     

英语第四册模拟练习题

综合练习 A1 完形填空(10分)Men first measured time(?)using a stick in the ground.The lengthof the(?)shadow would(?)what time of day it was.(?),the Egyp-tians used a pillar,(?)as a gnomon,and then developed a simple sundial,(?)consisted of a stone with a pointer on it.The stone was placed in aneast-west direction,and the shadow of the pointer showed the time.About 300 BC,a Babylonian(?)Berosus invented a semi-circularsundial,(?)he marked twelve hours.The Babylonians,like the Egyp-     

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.     

Three Wishes

Once upon a time,there lived a woodman and his wife.They were very poor,and they lived in a cottage on the edge of a forest.Every day,the woodman would set out early in the morning to chop down trees. As the woodman was travelling through the forest one day,he saw a