New coniferophyte ovulate structures from the Early Permian of China

نویسندگان
چکیده

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود 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 contorted New England Orogen (eastern Australia): New evidence from UPb geochronology of early Permian granitoids

[1] A series of sharp bends (oroclines) are recognized in the Paleozoic to early Mesozoic New England Orogen of eastern Australia. The exact geometry and origin of these bends is obscured by voluminous magmatism and is still debated. Here we present zircon U-Pb ages that confirm the lateral continuation of early Permian (296–288 Ma) granitoids and shed new light on the oroclinal structure. Orog...

متن کامل

Early Permian coal-forming floras preserved as compressions from the Wuda District (Inner Mongolia, China)

Four different compression/impression floras are preserved in only 4.32 m of the geologic section in the Early Permian Shanxi Formation of the Wuda District of Inner Mongolia, northwestern China. These floras represent four different plant communities and landscapes that followed each other in time. The oldest flora was rooted in sandy clay and initiated peat accumulation that lead to the forma...

متن کامل

the effect of traffic density on the accident externality from driving the case study of tehran

در این پژوهش به بررسی اثر افزایش ترافیک بر روی تعداد تصادفات پرداخته شده است. به این منظور 30 تقاطع در شهر تهران بطور تصادفی انتخاب گردید و تعداد تصادفات ماهیانه در این تقاطعات در طول سالهای 89-90 از سازمان کنترل ترافیک شهر تهران استخراج گردید و با استفاده از مدل داده های تابلویی و نرم افزار eviews مدل خطی و درجه دوم تخمین زده شد و در نهایت این نتیجه حاصل شد که تقاطعات پر ترافیک تر تعداد تصادفا...

15 صفحه اول

the role of task-based techniques on the acquisition of english language structures by the intermediate efl students

this study examines the effetivenss of task-based activities in helping students learn english language structures for a better communication. initially, a michigan test was administered to the two groups of 52 students majoring in english at the allameh ghotb -e- ravandi university to ensure their homogeneity. the students scores on the grammar part of this test were also regarded as their pre...

15 صفحه اول

Equisetites from the Early Permian of North-central Texas

Equisetites is a genus of fossil plants allied with, if not identical to, modern Equisetum, which is the only extant genus of the ancient lineage Sphenopsida. This class-level group of lower vascular plants is characterized by whorled vegetative and reproductive appendages, distinctive nodal and internodal morphologies, and unique "sporangiophores," specialized reproductive organs of uncertain ...

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: Botanical Journal of the Linnean Society

سال: 1999

ISSN: 0024-4074

DOI: 10.1111/j.1095-8339.1999.tb00495.x