历史查询   







 为了更好的帮助您理解掌握查询词或其译词在地道英语中的实际用法，我们为您准备了出自英文原文的大量英语例句，供您参考。 
Our approach generalizes Lévy's midpoint displacement technique which is used to generate Brownian motion.


Finite element simulations for compressible miscible displacement with molecular dispersion in porous media


We consider a nonlinear parabolic system describing compressible miscible displacement in a porous medium [5].


Galerkin method for completely compressible displacement with molecular diffusion and dispersion


In this paper, the numerical approximation by Galerkin method for completely compressible miscible displacement with molecular diffusion and dispersion in porous media is considered.

 更多 
It was found that in the Σ5 case two Burgers vectors of the structure are not simple basic complete displacement shift lattice (DSC) vectors and are larger than any one of them.


Burgers vectors associated with structural ledges and misfitcompensating ledges are displacement shift complete (DSC) lattice vectors.


They tend to cleave the carbene ligand with a simultaneous hydrogen displacement/shift.




 The socalled "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 contraflexure 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 socalled "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 contraflexure 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 spanchange 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 spanchange can not be neglected, so truss rigid frames belong to the same category of what may be called "spanchange" rigid frames such as rigid frames with curved or gabled beams. Therefore the spanchange constants of trusses should be included besides their anglechange 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 spanchange 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 slopedeflection. A twospan 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 spanchange 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 spanchange in trusses should not be neglected in their analysis.Finally, for analyzing co  所謂“桁架剛構”即以桁架為横梁与柱相剛接之剛構。現下採用分析剛構之任一方法,以分析此項剛構时,均須採用種種特殊之假定而得近似之結果。據著者所知,中外書刊中似尚无此項剛構之正確分析法。於本文中,著者發表关於桁架剛構正確分析之兩項原理,即柱頂力矩作用与桁架跨变影響之兩项原理。前項原理使柱頂段之角夔与桁架端豎桿相同,以符合柱与桁架剛接处之連续性。後項原理指出桁架与曲梁(即拱)及折梁(即山墙式梁)相同係一種“跨变横梁”,故桁架刚構亦与拱式及山墙式剛構相同,係一種“跨变剛構”。若根據此兩项原理,分别计算柱与桁架兩端的撓曲常数,再用分析跨变刚構之任一分析法以分析此項刚構,則所得之枯果,与不作任何特殊假定用最少功法或变位法所得者完全相同。本文先說明此兩项原理及根據此兩項原理计算柱与桁架撓曲常數之方法。次取一最簡單之桁架刚構为例,證明此丙項原理之正確性。桁架刚構既与拱式及山墙式刚構同属於跨变刚構一類型,分析後者之任何方法均可用以分析前者,本文无須贅述。但取一兩跨之桁架刚構為例,列举所得之正確結果,与用近似法所得者相比较,藉以顯出近似法有相當巨大之差誤。關於階形之複式桁架刚構之分析,本文用“代替桁架”之辦法,但只說... 所謂“桁架剛構”即以桁架為横梁与柱相剛接之剛構。現下採用分析剛構之任一方法,以分析此項剛構时,均須採用種種特殊之假定而得近似之結果。據著者所知,中外書刊中似尚无此項剛構之正確分析法。於本文中,著者發表关於桁架剛構正確分析之兩項原理,即柱頂力矩作用与桁架跨变影響之兩项原理。前項原理使柱頂段之角夔与桁架端豎桿相同,以符合柱与桁架剛接处之連续性。後項原理指出桁架与曲梁(即拱)及折梁(即山墙式梁)相同係一種“跨变横梁”,故桁架刚構亦与拱式及山墙式剛構相同,係一種“跨变剛構”。若根據此兩项原理,分别计算柱与桁架兩端的撓曲常数,再用分析跨变刚構之任一分析法以分析此項刚構,則所得之枯果,与不作任何特殊假定用最少功法或变位法所得者完全相同。本文先說明此兩项原理及根據此兩項原理计算柱与桁架撓曲常數之方法。次取一最簡單之桁架刚構为例,證明此丙項原理之正確性。桁架刚構既与拱式及山墙式刚構同属於跨变刚構一類型,分析後者之任何方法均可用以分析前者,本文无須贅述。但取一兩跨之桁架刚構為例,列举所得之正確結果,与用近似法所得者相比较,藉以顯出近似法有相當巨大之差誤。關於階形之複式桁架刚構之分析,本文用“代替桁架”之辦法,但只說明其原則,不列出公式及算例。  In this paper a method for computing the influence lines in open rigid frames is presented. This method is based on the MüllerBreslau's principle that every deflection diagram is an influence line. If any section of a given rigid frame, at which the influence llne of any stress function——such as reaction, shear, bending moment and torsion——is desired, is allowed to produce freely a corresponding unit deformation, the deflection diagram of this frame will be the same as the influence of that stress function.The... In this paper a method for computing the influence lines in open rigid frames is presented. This method is based on the MüllerBreslau's principle that every deflection diagram is an influence line. If any section of a given rigid frame, at which the influence llne of any stress function——such as reaction, shear, bending moment and torsion——is desired, is allowed to produce freely a corresponding unit deformation, the deflection diagram of this frame will be the same as the influence of that stress function.The fundamental idea of this method is that the anglechanges at ends of bars due to unit deformation can be determined by propagating joint rotations and that the resulting deflection diagram which is the same as the influence line of the corresponding stress function may be determined by method of conjugate beam.Typical numerical examples are worked out to show the application of this method.  本文提供一種求敞口剛架影響線的方法。依據米勒白斯老(MüllerBres1au)氏“變位線即影響線”的原理,令剛架中某點有與其應力函數相应的單位形变,則剛架因此所產生的變位曲線即為該應力函數的影響線。本文所叙述的方法,係利用角變傳播原理,求出各桿兩端由於上项單位形變所引起的角变,再根據此項角變求出各桿的變位曲線,亦即該應力函數的影響線。举有實例以示此法之應用。  The frequencies of free vibrations of an arch with fixed ends and a twohinged arch are calculated by method of deflection. With the use of a few suitable formulae or equations, the method is fairly straightforward.  在苏联出版的结构理认研究论论集的第五期和第六期的里面,教授写了两篇关于拱的振动的文章,第五期写的是拱的正对称振动,第六期写的是拱的反对称振动,他把一个拱分成六根刚性的桿,用弹性铰联在一起,用的方法似乎和结耩静力学里面用的分析拱的力法相同,我认为这个问题也可以把拱兰做刚架用变位法来解的,提出来请大家指教,因为公式比鲛简单的缘故,教授只算了内个双铰拱的自由振动。但是用变位法时,无铰拱和双铰拱的计算工作是差不多的。   << 更多相关文摘 
相关查询  



CNKI小工具

在英文学术搜索中查有关变位的内容

在知识搜索中查有关变位的内容

在数字搜索中查有关变位的内容

在概念知识元中查有关变位的内容

在学术趋势中查有关变位的内容



