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。 
It is defined thanks to a natural distance on the space of compact open subgroups of G.


Let S be a band in Z2 bordered by two parallel lines that are of equal distance to the origin.


However, the Mattila integral, associated with the Falconer distance problem for these measures is unbounded in the range $0 >amp;lt; s >amp;lt; \frac{d^2}{2d1}$.


They are Polish vector spaces for a natural distance.


Let M be a 3 X 3 matrix and d(M) is the distance to the diagonal algebra.

 更多 


 The gravitational field and the motion of matter in the universe are investigated according to Einstein's field equations and his dynamical equations of motion. In a spatially isotropic and homogeneous spacetime continuum it can be shown that up to about 2x10~8 l.y. the following relation holds between spectrum displacement δλ from distant spiral nebulae and their observationally defined distance d,where A is Einstein's cosmological constant. The first term on the right hand side is essentially Hubble... The gravitational field and the motion of matter in the universe are investigated according to Einstein's field equations and his dynamical equations of motion. In a spatially isotropic and homogeneous spacetime continuum it can be shown that up to about 2x10~8 l.y. the following relation holds between spectrum displacement δλ from distant spiral nebulae and their observationally defined distance d,where A is Einstein's cosmological constant. The first term on the right hand side is essentially Hubble and Humason's velocitydistance relation. The second part is a correction which amounts to 11.5% for d2x10~8 l.y. and hence lies within observational error of the present Mt. Wilson 100inch telescope. The theory shows that both Milne's recent Newtonian theory of the expanding universe and Lemaitre's interpretation of tha velocitydistance are first order approximations and are valid only within 2xl08 l,y. from our galaxy. The calculation for the phenomsna of nebular recession beyond 2xl08 l.y. to be observed by the 200inch telescope now under construction according to the present scheme will be presented in the near future.  本文用安因斯坦力学及引力论解释宇宙之膨胀现象。从本文方程式中可证明雷猛德及米恒诸氏之学说皆为本文之近似值,而本文理论之能成立与否须恃200英寸反光镜完成后之观测云。  Upper air visibility and vertical visibility are different from horizontal far distance visibility. They have special signifigance in aviation.In this paper the atmospheric extinction coefficieat, the upper air visibility and vertical visibility are calculated by observing the polit balloons and radiosonde balloons.The principle of visibility instrument is used that is making use of optical wedge, photoelectric cell etc, to carry out the measurement. Foitzik 1947, Duntley 1948, and some other scientists... Upper air visibility and vertical visibility are different from horizontal far distance visibility. They have special signifigance in aviation.In this paper the atmospheric extinction coefficieat, the upper air visibility and vertical visibility are calculated by observing the polit balloons and radiosonde balloons.The principle of visibility instrument is used that is making use of optical wedge, photoelectric cell etc, to carry out the measurement. Foitzik 1947, Duntley 1948, and some other scientists have disscnsed the problem of vertical visibility. Their method is to carry out the calculation with given atmospheric extinction coefficient, while in practical application this calculation is the second step, what we need to find out first is the atmospheric extinction coefficient. In Duntley's paper, he assumes that within the limit of discussion, the intensity of sky light is constant. But this can only be true within a very thin layer of atmosphere, as to the atmosphere which is kilometres thick, it has to consider the attenuation of light by the atmosphere. Furthermore he assumes that the anisotropy of atmosphere's scattering function is invariant with height and then it is considered as a molecular atmosphere. But this has been proved by several authors in theory and in experiment to be not true, especially in the lower atmosphere. Certainly, Duntley's calculation is not accurate and is limited in application.A correction has been given to the above mentioned assumptions in this paper. Finally, the problem of light of source visibility in night and some other materials on observation are being discussed.  高空能见度,垂直能见度是和地平远程能见度不相同的。在航空方向,高空能见度与垂直能见度具有着特殊的意义。 本文藉助于测风气球及雷送气球的观测,计算大气削弱系数,从而计算高空能见度与垂直能见度。 我们利用莎罗诺夫能见度仪器的原理:利用光楔,光电池等进行测量。  It has long been realised that for laminar flow through a circuclar pipe, the Poiseulle's velocity distribution exits only at a sufficient distance downstream from the entrance to the pipe. For a wellrounded entrance, the velocily distribution at the entrance is approximately uniform, it then varies gradually with the distance from the entrance until the parabolic distribution is fully developed. The distance from the entrance required for practically complete transition has been calculated... It has long been realised that for laminar flow through a circuclar pipe, the Poiseulle's velocity distribution exits only at a sufficient distance downstream from the entrance to the pipe. For a wellrounded entrance, the velocily distribution at the entrance is approximately uniform, it then varies gradually with the distance from the entrance until the parabolic distribution is fully developed. The distance from the entrance required for practically complete transition has been calculated by Boussiuesq and olso by Schiller, and formulas for calculating tle transition length have been proposed. For laminar flow between parallel plates, however, no information for the length of transition appears to be available. An attempt is thus made, in this paper, to calculate this lenqth by applying Schiller's theory; and the result obtained is given by L=0.0259bR in which L is the transition length, b is half the distance between the plates and R is the Reynolds number.  我們很早就知道流體在圓管中作層流運動時,泊西里(Poiseulle)的流速分佈只是在距進口處相當長的一段距離處才能實現。如管子進口是圓滑的,則在進口處斷面上的流速是均匀分佈的,此後流速分佈即逐漸轉變直至抛物線形的流速分佈完全形成爲止。由進口處至完全轉化成抛物線形流速分佈所需的距離曾先後經鮑辛尼斯克(Boussinesq)和錫拉(Schiller)進行過研究,他們求得了計算此轉化長度的公式。但是對於在二平行平板間的層流運動,其轉化長度的計算尚無公式可資利用。爲此本文應用錫拉理論對此進行了計算,求得了此轉化長度的公式爲L=0.0259bR,式中,L爲轉化長度,R爲雷諾數,b爲二平板間的距離之半。   << 更多相关文摘 
相关查询  



