Ab initio calculations of depolarization ratios and intensities of classically scattered light, in terms of dipole polarizabilities and polarizability anisotropies, are reported for different hydrogen bonded molecular clusters. Five different groups of organic heterodimers formed with water are considered: HCHO · · ·H2O, CH3HO · · ·H2O, HCOOH · · ·H2O, CH3CN · · ·H2O, and (CH3)2CO · · ·H2O, tog...

Density functional theory (DFT) calculations are carried out to investigate partial oxidation of propylene over neutral VO 3 clusters. C=C bond cleavage products CH 3CHO + VO 2CH 2 and HCHO + VO 2CHCH 3 can be formed overall barrierlessly from the reaction of propylene with VO 3 at room temperature. Formation of hydrogen transfer products H 2O + VO 2C 3H 4, CH 2=CHCHO + VO 2H 2, CH 3CH 2CHO + V...

امروزه کاربردهای تصاویر ماهواره‌ای، در پایش و مدیریت زمین‌های کشاورزی، رو به گسترش است. با توجه قدرت تفکیک مکانی، طیفی زمانی بالای سنتینل‌ـ 2، این مطالعه، کشاورزی دقیق شهرستان قروه از استفاده شده ابتدا تقویم زراعی محصولات متفاوت آن منطقه، سری جمع‌آوری شد. روش پیشنهادی، نخست، فضای ویژگی براساس بازتاب باندها همچنین شاخص‌های گیاهی، ایجاد ابعاد طیفی، آنالیز مؤلفه‌های اصلی، کاهش یافت. سپس چهار طبقه‌...

The dielectric constant and the pyroelectric coefficient at constant stress of 1-lithium hydrogen dimalate l-Li®(OOCCHOHCH 2CO O H )e (HOOCCHOHCH2COOH), were investigated in the temperature range 200 S 77K ^ Td (decomposition temperature) and 100 ^ T/K ^ Td, respec­ tively. The compound crystallizes in the space group P2j. In the direction of the 2, axis £22 increases with almost constant slope...

1 ABSTRACT The atmospheric General Circulation Model of the Laboratoire de M et eorologie Dynamique (LMD) is coupled to a slab ocean model and is used to investigate the climatic impact of a CO 2 doubling. Two versions of the model are used with two diierent representations of the cloud-radiation interaction. Both of them contain a prognostic equation for the cloud liquid water content, but the...

The effect of fertilization in the first growing season on early survival and growth of narrow-leaved ash (NLA) (Fraxinus angustifolia ssp. oxycarpa) was evaluated throughout the first 3 years of growth in Adapazari, Turkey. A randomized complete block design with four replications was established to investigate fertilization effects. Granular N urea [46%, (NH2)2CO, NH2-N] and NPK (15/15/15%; N...

The class of [NiFe]-hydrogenases is characterized by a bimetallic cofactor comprising low-spin nickel and iron ions, the latter of which is modified with a single carbon monoxide (CO) and two cyanide (CN-) molecules. Generation of these ligands in vivo requires a complex maturation apparatus in which the HypC-HypD complex acts as a 'construction site' for the Fe-(CN)2CO portion of the cofactor....

Substituted Internal Alkene Complex Kerry A. Pickin, Cynthia S. Day, Marcus W. Wright, and Mark E. Welker* Department of Chemistry, Wake Forest University, P.O. Box 7486, Winston-Salem, NC 27109 An unusual cobaloxime substituted terminal alkene has been isolated and characterized by X-ray crystallography. The double bond in the alkene readily isomerizes but the title compound could be isolated ...

A fundamental problem in astrochemistry concerns the synthesis and survival of complex organic molecules (COMs) throughout the process of star and planet formation. While it is generally accepted that most complex molecules and prebiotic species form in the solid phase on icy grain particles, a complete understanding of the formation pathways is still largely lacking. To take full advantage of ...