xr x 中文意思是什麼
xr x
解釋
射線-
The company passed iso9001 in 2001 : 2000 international quality management system attestations. now the predominant product has already become xr series helical gear units, xf series parallel shaft helical gear units, xk serial helical - bevel gear units, xs series helical - worm gear units, xt series spiral bevel gear units, xb series high power gear units, xh series high power gear units, nmrv series worm gear units, mb, mbn series planetary friction mechanical speed variator, x, b series cycloid reducer, wb series cycloid micro reducer to wait more than ten serieses, several thousand kinds of specificationses of in general use product
現主導產品已形成xr系列斜輪硬面減速機xf系列平行軸斜輪減速機xk系列斜輪螺旋錐輪減速機xs系列斜輪蝸輪減速機， xt系列螺旋錐輪減速機， xb系列螺旋錐輪-斜輪減速機xh系列平行軸斜輪減速機nmrv系列蝸輪減速機， mb mbn系列行星錐盤無級變速機， x b系列擺線針輪減速機， wb微型擺線針輪減速機等十幾個系列數千種規格的通用產品。 -
Xr, x. r. ex - right
無優惠權認購新股 -
X - ray diffractomer xr
射線衍射儀 -
The paper is concerned with periodic solutions to nonautonomous second order hamilton systems where, m : [ 0, t ] - s ( rn, rn ) is a continuous mapping in the space s ( rn, rn ) of symmetric real ( n x n ) - matrices, such that for some u > 0 and all ( t, z ) [ 0, t ] x rn, ( m ( t ) x, x ) > u | x | 2. a s ( rn, rn ), f : [ 0, t ] x rn r is continuous and f : [ 0, t ] xr r exists, is continuous and we study the existence of periodic solutions of the systems by using ekeland variational principle and the saddle points theorem. we suppose that the nonlinearity vf and potential f belongs to a class of unbounded functional. our work improves the existed results. we obtained the results of multiplicity of periodic solutions of the systems by using lusternik - schnirelman category theory and the generalized saddle points theorem, and the functional does not need the condition of constant definite. at last, we obtained the existence of infinity many distinct periodic solutions of the corresponding non - perturbation systems by using the symmetric mountain pass theorem
（ ? ， ? ）為r ~ n中內積， | ? |為對應范數。 f [ 0 ， t ] r ~ n r連續， ? f （ t ， x ）存在且連續， h l ~ 1 （ 0 ， t ； r ~ n ） 。利用ekeland變分原理和鞍點定理討論了該系統周期解的存在性，把非線性項和位勢函數放寬到一類無界函數，推廣了這方面工作的一些已有結果；利用廣義鞍點定理和lusternik - schnirelman疇數理論得到了該系統的多重周期解，取掉了泛函的常定要求；最後利用對稱山路定理得到沒有擾動時系統的無窮多周期解。
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