Halley's comet is quite young

نویسندگان

چکیده

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

The Function Field Sieve Is Quite Special

In this paper, we describe improvements to the function field sieve (FFS) for the discrete logarithm problem in Fpn , when p is small. Our main contribution is a new way to build the algebraic function fields needed in the algorithm. With this new construction, the heuristic complexity is as good as the complexity of the construction proposed by Adleman and Huang [2], i.e Lpn [1/3, c] = exp((c ...

متن کامل

Is Enceladus a Comet? a Cometary Perspective

Introduction: The discovery of icy plumes emanating from Saturn's moon Enceladus by the Cassini spacecraft has raised questions about the cometary nature of this small satellite. The release of gas and dust from cometary nuclei is restricted to " jets " or plumes also and this activity has been observed in comets at distances much further than Saturn's orbit, including comet-like activity and a...

متن کامل

ABL alternative splicing is quite frequent in normal population - letter.

In the article by Lee et al. (1), an alternative splicing of BCR-ABL is proposed as a mechanism for imatinib resistance in chronic myeloid leukemia (CML) patients. This splicing (2), which inserts 35 bp between exons 8 and 9 of ABL (35INS), results in a truncated BCRABL protein that the authors compare dynamically with the native protein. We found their work very relevant, especially the findin...

متن کامل

Why Operativity-in-Context Is Not Quite a Sociocultural Model

Understanding cognitive development requires building up an approach that can effectively integrate constructivist and sociocultural perspectives, and this paper [Psaltis, Duveen, & Perret-Clermont, this issue] offers a useful contribution to that effort from a neo-Piagetian direction. Its key contribution lies in its overview and assessment of a line of empirical work situating children’s cogn...

متن کامل

Cosmology Solved? Quite Possibly!

The discovery of the cosmic microwave background (CMB) in 1964 by Penzias and Wilson led to the establishment of the hot big-bang cosmological model some ten years later. Discoveries made in 1998 may ultimately have as profound an effect on our understanding of the origin and evolution of the Universe. Taken at face value, they confirm the basic tenets of Inflation + Cold Dark Matter, a bold an...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Nature

سال: 1989

ISSN: 0028-0836,1476-4687

DOI: 10.1038/339095a0