نتایج جستجو برای: p d a
تعداد نتایج: 13785731 فیلتر نتایج به سال:
a two-dimensional nanolayered polyoxomolybdate, [4,4´-h2bipy] [mo7o22].h2o (1), where 4,4´-bipy = 4,4´-bipyridine, was prepared and characterized by ft-ir and atomic absorption spectroscopies, transmission electron microscopy (tem), x-ray single crystal and powder diffraction (xrd), and thermogravimetric analysis. the catalytic performance of 1 was assessed in the epoxidation of some olefins em...
% .3 +4 % . .+ %/ 01" ,-" ( )*+ -" )*+ #$ >4 % (! .5+ .3 6 7 !# 87 9: 8; 8<" .= c % " -7?" @ a!" b 6 6!! ," #% b !" (i 1) .3 (! .5+ 9d" e!f 9= ." g)*+ #$ &/"< p c #$ m5n" b c >o1 . k b#0 l &t gv5n" #$ % 50 &t % 50 g&t % 100) #$ m5n" e + w" x5 y4 z7[ "% . (#$ % 100 g" @ #$ n % 4 2 31" cropwat " ] . % " % . 6 k a17 % #+ 8$ g; e!f 9= a % m5n" b / &" `. !ib ....
a facile and efficient method for the preparation of 1, 1-diacetates of aldehydes is improved.p2o5/sio2 catalyzed 1, 1-diacetates formation from aldehydes in dry media. advantages of this methodare the use of an inexpensive and selective catalyst with high yields in simple operation and shortreaction time under solvent-free conditions.
فرض کنید a?c^n×n باشد.ماتریس a^d را معکوس درازین ماتریس a گوییم، هرگاه در سه شرط زیر a^d aa^d=a^d, a^d a=aa^d, a^(k+1) a^d=a^k که در آن k بزرگترین بلوک جردن متناظر با مقدار ویژه صفر ماتریس a می باشد، به نام شاخص a ، که با ind(a) نشان می دهیم، صدق کند. سیدی با تعمیم روش زیر فضای کریلف برای دستگاه های منفرد، یک چارچوب کلی برای محاسبه جواب معکوس درازین دستگاه ax=b ارایه نمود و خواص آن را مورد ب...
objective: epilepsy is a chronic neurological disorder requiring long term therapy using antiepileptic medications. reports have incriminated long term antiepileptic drugs use in deficiency of vitamin d and bone diseases in all age groups. to investigate the association between serum 25-hydroxyvitamin d levels and pediatric epilepsy in indian patients. methods& methods: we prospective...
to study the response of pinto-bean yield and yield components in intercropping with maize and naked-pumpkin under weed competition, two similar experiments were conducted in rasht and roudsar separately each in a randomized complete block design with 3 replications on factorial arrangements experiment in 2013. the treatments of first factor consisted of pinto bean (100 and 75%) sole cropping,...
background: radiotherapy treatment planning requires different dosimetric quantities as input in order to calculate a desired dose distribution. this study has been focused to evaluate the depth dose characteristics of superficial x-rays being used for radiotherapy treatment. materials and methods: computerized 3-d water phantom of multi-data system was used. the measurements were made through ...
in this work, zncao2 (zinc oxide-calcium oxide) nanocomposite were synthesized at different temperatures (500-700°c) by sol-gel method based on polymeric network of polyvinyl alcohol (pva). the synthesized samples were characterized by sem/edax, ft-ir and xrd techniques. it was found that synthesized nanocomposites have 1.62, 2.05 and 13.91%wt of cao, respectively. the obtained results show tha...
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