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1.
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.  相似文献   

2.
Probability density function (PDF) method is proposed for analysing the structure of the reconstructed attractor in computing the correlation dimensions of RR intervals of ten normal old men. PDF contains important information about the spatial distribution of the phase points in the reconstructed attractor. To the best of our knowledge, it is the first time that the PDF method is put forward for the analysis of the reconstructed attractor structure. Numerical simulations demonstrate that the cardiac systems of healthy old men are about 6 - 6.5 dimensional complex dynamical systems. It is found that PDF is not symmetrically distributed when time delay is small, while PDF satisfies Gaussian distribution when time delay is big enough. A cluster effect mechanism is presented to explain this phenomenon. By studying the shape of PDFs, that the roles played by time delay are more important than embedding dimension in the reconstruction is clearly indicated. Results have demonstrated that the PDF method represents a promising numerical approach for the observation of the reconstructed attractor structure and may provide more information and new diagnostic potential of the analyzed cardiac system.  相似文献   

3.
In the Ode to the Grecian Urn Keats came to the realization that the immortality he had quested for is a myth that cannot be interpreted. The marbleized sacrificial rite on the ancient urn implies that human life is a process of endless sacrifice. This inevitable recognition of mortal limitation during the process of human growth can not be dissolved by the soothing oracle that Beauty is truth, truth beauty'.  相似文献   

4.
The combination of online or semi-online with deterioration jobs has never been researched in scheduling problems. In this paper, two semi-online parallel machine scheduling problems with linear deterioration processing time are considered. In the first problem, it is assumed that the deterioration rates of jobs are known in an interval, that is, bj ∈[0, α], where 0 〈α≤ 1 and bj denotes the linear deterioration rate. In the second problem, it is assumed that the largest deterioration rate of jobs is known in advance, that is, b = max1≤j≤n {bj }. For each of the two problems, a heuristic MBLS algorithm is worked out and its worst-case ratio is analyzed. At the same time, the worst-case ratio of the list (LS) algorithm is investigated and it is proved that all the ratios are tight.  相似文献   

5.
This paper presents the forward displacement analysis of an 8-PSS (prismatic-spherical-spherical) redundant parallel manipulator whose moving platform is linked to the base platform by eight kinemtic chains consisting of a PSS joint and a strut with fixed length. A general approximation algorithm is used to solve the problem. To avoid the extraction of root in the approximation process, the forward displacement analysis of the 8-PSS redundant parallel manipulator is transformed into another equivalent problem on the assumption that the strut is extensible while the slider is fixed. The problem is solved by a modified approximation algorithm which predicates that the manipulator will move along a pose vector to reduce the difference between the desired configuration and an instantaneous one, and the best movement should be with minimum norm and least quadratic sum. The characteristic of this modified algorithm is that its convergence domain is larger than that of the general approximation algorithm. Simulation results show that the modelified algorithm is general and can be used for the forward displacement analysis of the redundant parallel manipulator actuated by a revolute joint.  相似文献   

6.
Vanishing torsion of parametric curves   总被引:1,自引:0,他引:1  
We consider the class of parametric curves that can be represented by combination of control points and basis func- tions. A control point is let vary while the rest is held fixed. It’s shown that the locus of the moving control point that yields points of zero torsion is the osculating plane of the corresponding discriminant curve at its point of the same parameter value. The special case is studied when the basis functions sum to one.  相似文献   

7.
The mechanism involving the effect of disorder/order transformation on the environmental embrittlement in gaseous H2 is summarized. It is shown that there is no hydrogen embrittlement in disordered state of Kurnakov type intermetallics in gaseous H2. However, the H2-induced environmental embrittlement for the ordered alloy having identical chemical composition becomes severer as the degree of the order increases. The results of testing on the ion gage turned on and off during tensile testing show that the more sensitive to H2-induced hydrogen embrittlement for ordered alloy than disordered one is attributed to the fact that atomic ordering may accelerate the kinetics of the catalytic reaction to produce more atomic hydrogen. The results on simultaneous hydrogen charging show that disordered alloys embrittled as hydrogen atoms are forced into the material implying that the embrittlement of ordered alloy in gaseous H2 is also due to the acceleration of the kinetics of catalytic reaction. The above suggestion was further verified by the adsorption tests of Ni3Fe intermetallics powder. It is shown that the amount of chemically adsorbed hydrogen in ordered state is significantly larger than that adsorbed by the disordered alloy, indicating that the more sensitive to H2-induced embrittlement in the ordered state of alloy is essentially due to the accelerated catalytic reaction.  相似文献   

8.
张青  郝志远 《时代教育》2007,(8Z):141-141,147
In the Ode to the Grecian Urn Keats came to the realization that the immortality he had quested for is a myth that cannot be interpreted. The marbleized sacrificial rite on the ancient urn implies that human life is a process of endless sacrifice. This inevitable recognition of mortal limitation during the process of human growth can not be dissolved by the soothing oracle that 'Beauty is truth, truth beauty'.  相似文献   

9.
张青 《双语学习》2007,(7M):175-176
In the Ode to the Grecian Urn Keats came to the realization that the immortality he had quested for is a myth that cannot be interpreted. The marbleized sacrificial rite on the ancient urn implies that human life is a process of endless sacrifice. This inevitable recognition of mortal limitation during the process of human growth can not be dissolved by the soothing oracle that Beauty is truth, truth beauty:  相似文献   

10.
Greenland     
Greenland is in the north of Europe.It's targer thanany other island in the world.Near Greenland is another is-land.It is small.Its name is Iceland.Do you think that Green-land is green and warm?Do you think that Iceland is white  相似文献   

11.
短文改错5题     
一In America,Monday is the day that most people likeLeast.Monday was the beginning of the workweek.It’snot surprised that the day they like most isFriday,which is end of the workweek.Life is different on the weekend:most AmericanTake care of their houses…  相似文献   

12.
刁俊春 《海外英语》2013,(6X):195-197
This paper tries to analyze Philip Larkin’s poem"High Window"from a deconstructive perspective. It is to show that in the poem the key words/signifiers are always under erasure, and thus the chain of signification is endless since the poem is self-deconstructing. Then, the paper argues that the linguistic features of the poem paradoxically meaningful in the sense that it reflects the poet’s skepticism and anxiety.  相似文献   

13.
It is explored that the line integral is a path independent in two or three arbitrary dimensional orthogonal curvilinear coordinate systems, which is based on the integral condition with the path independent in two or three dimensional rectangular coordinate systems. Firstly, according to the coordinate transformation, the condition that the line integral is the path independent in the polar coordinate system is obtained easily from the Green’s theorem in two-dimensional rectangular coordinate system and the condition is extended to arbitrary two-dimension orthogonal curvilinear coordinates. Secondly, through the coordinate transformation relationship and the area projection method, the Stokes formula in three-dimensional rectangular coordinate system is promoted to the spherical coordinate system and cylindrical coordinate system, and the condition that the line integral is a path independent is obtained. Furthermore, the condition is extended to arbitrary three-dimension orthogonal curvilinear coordinates. Lastly, the conclusions are made.  相似文献   

14.
张格 《海外英语》2012,(16):283-284
The language is a play of signs. However, behind the signs is the culture manipulates the signs. The sign is the surface structure; while under the surface is that the thinking pattern matters, which is the only small part of the culture. The culture difference always exists. I would like to study it in terms of the problems which the essay reveals. The first part is to list examples, and the second part tries to analyze it in terms of thinking patterns. The last part is the concluding part. It intends to find solutions to avoid that problem.  相似文献   

15.
The rules in this area arecomplex.1.Isuggest that you do it.[Don't say:l suggest you to doit.]This indicates that it is true.[Don'tsay:This indicates it to be true.]These patterns hold for the noun form:His suggestion is that we do it.All the in dications are that it is true.[Exercise1]Say if the bracketed passage is correct. If it  相似文献   

16.
As the old saying goes that interest is the best teacher and it is quite true that the students’initiative in learning is diffi cult to spur without interest.English is the most widely used language in the world,and people are aware of the importance and necessity in English learning.But English is a second language to us,so learning it is more difficult than the acquiring of our na tive language.Interest is the internal power to spur students’learning.So how to spur the students’s interest in engliash learning is the main prblem discussing in it.  相似文献   

17.
The more unambiguous statement of the P versus NP problem and the judgement of its hardness, are the key ways to find the full proof of the P versus NP problem. There are two sub-problems in the P versus NP problem. The first is the classifications of different mathematical problems (languages), and the second is the distinction between a non-deterministic Turing machine (NTM) and a deterministic Turing machine (DTM). The process of an NTM can be a power set of the corresponding DTM, which proves that the states of an NTM can be a power set of the corresponding DTM. If combining this viewpoint with Cantor’s theorem, it is shown that an NTM is not equipotent to a DTM. This means that "generating the power set P(A) of a set A" is a non-canonical example to support that P is not equal to NP.  相似文献   

18.
In this paper,the expected discounted penalty function is considered in the risk process with the time-correlated claims,that is,every main claim can cause a by-claim but the occurrence of the by-claim may be delayed.By the renewal argument,it is shown that the expected value satisfies a system of integro-differential equations.Moreover,the explicit expression for the Laplace transform of the expected value is derived by means of Rouchés theorem.A numerical example is  相似文献   

19.
This paper studies the modelling and simulation for all forms of hcaters.The assumption of former days that the temperature of condensation is the saturationtemperature corresponding to heater pressure in steam side is no longer used.On the basisof the laws of conservation of mass,energy and momentum,the mathematical model ofheaters is established and the simulation calculation of a 125MW unit is made.The rcsultshows that the model is applicable for various kinds of steam-water heater in power plant.  相似文献   

20.
A cognitive relay network model is proposed, which is defined by a source, a destination, a cognitive relay node and a primary user. The source is assisted by the cognitive relay node which is allowed to coexist with the primary user by imposing severe constraints on the transmission power so that the quality of service of the primary user is not degraded by the interference caused by the secondary user. The effect of the cognitive relay node on the proposed cognitive relay network model is studied by evaluating the outage probability under interference power constraints for different fading environments. A relay transmission scheme, namely, decode-and-forward is considered. For both the peak and average interference power constraints, the closed-form outage expressions are derived over different channel fading models. Finally, the analytical outage probability expressions are validated through simulations. The results indicate that the proposed model has better outage probability than direct transmission. It is also found that the outage probability decreases with the increase of interference power constraints. Meanwhile, the outage probability under the average interference power constraint is much less than that under the peak interference power constraint when the average interference power constraint is equal to the peak interference power constraint.  相似文献   

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