M416_7a 39..44
نویسندگان
چکیده
A long-standing question in the planetary sciences asks what the Earth is made of. For historical reasons, volatile-depleted primitive materials similar to current chondritic meteorites were long considered to provide the `building blocks' of the terrestrial planets. But material from the Earth, Mars, comets and various meteorites have Mg/Si and Al/Si ratios, oxygen-isotope ratios, osmium-isotope ratios and D/H, Ar/H2O and Kr/Xe ratios such that no primitive material similar to the Earth's mantle is currently represented in our meteorite collections. The `building blocks' of the Earth must instead be composed of unsampled `Earth chondrite' or `Earth achondrite'.
منابع مشابه
Computer Assisted Ontology clustering for Knowledge sharing
Department of Computer Science, The University of Liverpool, Chadwick Building, Peach Street, Liverpool, L69 7ZF, UK, tel: +44-151-794 3706, fax: +44-151-794 3715, email: [email protected] SAP AG Entw. HR HRMS Netherlands, PO Box 1461, D-69190 Walldorf, Germany, tel: +49-622776 47 45, fax: +49-6227-77 47 45, email: [email protected] Dipartimento di Informatica, Universita' degli Studi di ...
متن کاملThe Effect of Stifle Angle on Stifle Kinematics following TPLO
.......................................................................... ii ACKNOWLEDGEMENTS......................................................... iii TABLE OF CONTENTS............................................................ iv INTRODUCTION................................................................... 1 CHAPTER I: Literature Review.....................................................
متن کاملFirst births to older women continue to rise.
KEY FINDINGS Data from the National Vital Statistics System The first birth rate for women aged 35-39 increased from 1970 to 2006, decreased from 2006 to 2010, and increased again in both 2011 and 2012. The first birth rate for women aged 40-44 was steady in the 1970s and started increasing in the 1980s. The rate more than doubled from 1990 to 2012. For women aged 35-39 and 40-44 all race and H...
متن کاملThe effects of methylamine osmolytes on the cytoskeleton microtubule assembly
16 Introduction 17 Materials and Methods 20 Results 23 Discussion 33 Acknowledgments 37 References 37 CHAPTER 3: TRIMTHYLAMINE N-OXIDE CAN PROMOTE 39 PHOSPHORYLATED TAU-TUBULIN ASSEMBLY Abstract 39 Introduction 41 Materials and Methods 4439 Introduction 41 Materials and Methods 44
متن کاملCoping with loneliness
............................................................................................................................... 37 Introduction ......................................................................................................................... 39 Methods ...........................................................................................................................
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2002