نتایج جستجو برای: شبکه 14 وجهی

تعداد نتایج: 395361  

2008

Very soon after the discovery of radioactivity, measurements of the heavy radioactive elements existing in nature were undertaken to determine the age of rocks (Rutherford 1904), but only when Professor Willard Libby in an evening lecture during the first United Nations Conference on the Peaceful Uses of Atomic Energy in Geneva in 1955 described how he and his research team had evolved the carb...

2014
Hideyuki Takahashi Naoko Adachi Toshihiko Shirafuji Sally Danno Takehiko Ueyama Michele Vendruscolo Anton N. Shuvaev Takuya Sugimoto Takahiro Seki Daizo Hamada Kazuhiro Irie Hirokazu Hirai Norio Sakai Naoaki Saito

Biosignal Research Center, Kobe University, Kobe 657-8501, Japan, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK, Department of Neurophysiology, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan, Department of C...

Journal: :Science 2001
G Siani M Paterne E Michel R Sulpizio A Sbrana M Arnold G Haddad

Sea surface reservoir ages must be known to establish a common chronological framework for marine, continental, and cryospheric paleoproxies, and are crucial for understanding ocean-continent climatic relationships and the paleoventilation of the ocean. Radiocarbon dates of planktonic foraminifera and tephra contemporaneously deposited over Mediterranean marine and terrestrial regions reveal th...

Journal: :Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association 2010
Myriam Coulet Jean-Charles Leblanc R Woodrow Setzer

Sudan I is generally considered mutagenic based on various in vitro and in vivo tests and is carcinogenic in the rat. Dose-response modelling of the data for hepatocellular adenomas in male rats gave a BMDL(10) of 7.3mg/kg-bw/day. Sudan I is an unauthorised substance that might be present in food intermittently. The great variability and uncertainties in the human exposure data which are countr...

ژورنال: ادب فارسی 2016

وجه به­طورکلی مقوله‌ای معنایی است که دیدگاه گوینده را دربارۀ گزاره‌ای نشان می‌دهد. عناصر وجهی مختلفی در زبان برای انتقال وجه وجود دارد؛ به­عبارت­دیگر، زبان‌ها ابزارهای مختلفی برای بیان مفاهیم وجهی در اختیار دارند؛ یکی از این ابزارها، وجه فعلی است. وجه فعلی آن جنبه از وجه است که در ساخت‌واژۀ فعل و از طریق صرف آن نمودار می‌شود و مقوله­ای دستوری است. با بررسی تاریخ دستورنویسی فارسی، مشخص می‌شود که...

ژورنال: :جستارهای زبانی 2015
محمَدحسن جلالیان چالشتری

در مطالعة زبانهای  کهن ایرانی مسائل نحوی از اقبال چندانی برخوردار نیستند و زبان سغدی هم از این مسأله مستثنی نیست. به این علّت که متون بازمانده سغدی عموماً ترجمه هایی از زبانهای دیگر  تشخیص داده شده اند دانشمندان کمتر به بررسی نحوی این متون اهتمام ورزیده اند. تعیین میزان تأثیرگذاری زبانهای مبدأ بر نحو زبان متون سغدی از سویی و وجود تمایز بین گونه های مختلف زبانی آن از دیگر سو خود مسائلی هستند که بد...

Journal: :The Biochemical journal 1974
I H White J Jeffery

Kinetic measurements were made with cortisone reductase (20-dihydrocortisone-NAD(+) oxidoreductase, EC 1.1.1.53) and a series of substrates which differed in shape, size and electronic character in the region adjacent to C-11, C-14 and C-18. Structural changes at C-11 in these substrates resulted in up to 660-fold changes in the apparent K(m) value, up to 200-fold changes in the apparent V(max....

Journal: :Science 2009
Vasilii V Petrenko Andrew M Smith Edward J Brook Dave Lowe Katja Riedel Gordon Brailsford Quan Hua Hinrich Schaefer Niels Reeh Ray F Weiss David Etheridge Jeffrey P Severinghaus

The cause of a large increase of atmospheric methane concentration during the Younger Dryas-Preboreal abrupt climatic transition (approximately 11,600 years ago) has been the subject of much debate. The carbon-14 (14C) content of methane (14CH4) should distinguish between wetland and clathrate contributions to this increase. We present measurements of 14CH4 in glacial ice, targeting this transi...

2013
Walter E. Brown

Although this paper is self-contained, it logically follows our discussion, begun several years ago in N1706 and continued in N1891, of a feature oft-requested for C++: an opaque typedef , sometimes termed a strong typedef . The earlier of those works was presented to WG21 on 2004-10-20 during the Redmond meeting, and the later work was presented during the Berlin meeting on 2005-04-06. Both pr...

Journal: :Science 2001
G Bond B Kromer J Beer R Muscheler M N Evans W Showers S Hoffmann R Lotti-Bond I Hajdas G Bonani

Surface winds and surface ocean hydrography in the subpolar North Atlantic appear to have been influenced by variations in solar output through the entire Holocene. The evidence comes from a close correlation between inferred changes in production rates of the cosmogenic nuclides carbon-14 and beryllium-10 and centennial to millennial time scale changes in proxies of drift ice measured in deep-...

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