检索结果-南通市图书馆

Clay Mineral and Geochemical Proxies for Intense Climate Change in the Permian Gondwana Rock Record from Eastern India

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research 2019年第1期2019卷 186-199页

作者： Sampa Ghosh Joydip Mukhopadhyay abhijit chakraborty Department of Geology Presidency University86/1 College StreetKolkata-700073India Department of Geology Jogamaya Devi College92 Shyama Prasad Mukherjee Road700026KolkataIndia

The clay mineral assemblages and geochemical compositions of the Permian Talchir and Barakar mudstones of the Raniganj basin,India,have been used to interpret terrestrial *** Talchir Formation presents unequivocal evidences of the Permian global glacial climate,and the overlying Barakar Formation with braided fluvial deposits immediately follows the glacial amelioration stage to a humid warm *** unaffected by burial diagenesis and originated from a similar source under contrasting climates are ideal for developing proxies for substantial climate ***(28.4-63.8%),illite/smectite(0-58.6%,40-80%illite),chlorite(0-53.9%),and chlorite/smectite(5.6-29.8%)constitute the clay mineral assemblage in the Talchir Formation whereas illite(5.3-78.2%),illite/smectite(trace-34.1%,mostly 60-90%illite),and kaolinite(36.1-86.8%)dominate the clay mineral assemblage in the Barakar *** Talchir mudrocks are enriched in mobile elements and depleted in alumina ***,have relatively higher K_(2)O/Al_(2)O_(3) ratios(~0.3),high ICV(1.12-1.28),and lower CIA values(52.6-65.1)compared to those of the younger Barakar *** Barakar mudstones are depleted in mobile elements ***,have relatively low ICV(0.33-0.62)and K_(2)O/Al_(2)O_(3) values(0.11-0.16),and higher CIA values(72.9-88.2).Textural,mineralogical immaturity,and rock fragments of different components of the basement seen in the Talchir sandstones show these sediments being a first-cycle sedimentary *** distinctive clay mineral assemblage and major oxide composition of the Talchir mudrocks attest to a unique low intensity chemical weathering in cold arid *** presence of kaolinite as well as distinctive geochemical characters of the Barakar mudrocks marks a shift in the paleoclimate from cold arid to *** climatic shift is further supported by the proportion and composition of illite/smectite across the *** relative proportion of chlorite

关键词： Permian mudstone assemblage

Identification of regulatory sequence signatures in microRNA precursors implicated in neurological disorders

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Bioscience and Biotechnology 2013年第5期4卷 26-33页

作者： Sayak Ganguli Sasti Gopal Das Hirak Jyoti chakraborty Sohini Gupta abhijit Datta DBT Centre for Bioinformatics Presidency University Kolkata India

MicroRNAs have emerged as one of the major classes of non-coding RNAs. Recent reports have placed them in high abundance in the nervous system, having key roles in development. Neurological disorders such as Parkinson’s disease, Alzheimer’s disease as well as Huntington disease have also been studied and several microRNAs associated with diseases pathogenesis have been identified. Various such findings indicate differential expression levels of many of these microRNAs. Such changes in the expression levels not only indicate towards a control of the biogenesis of these microRNAs but also indicate towards critical yet unelucidated roles of regulatory proteins, which probably act in concert to control the production or maturation of these molecules. In this work, a collection of overrepresented regulatory motif signatures were identified in the DNA and RNA sequences of the precursor microRNAs. The identification of such regulatory sequence signatures promises to provide new insights into many facets of microRNA regulation and neurological disorders.

关键词： Neurological Diseases Regulatory Motif Signatures Parkinson’s Disease Alzheimer’s Disease Huntington Disease

Track forecast:Operational capability and new techniques-Summary from the Tenth International Workshop on Tropical Cyclones(IWTC-10)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Tropical Cyclone Research and Review 2023年第1期12卷 64-80页

作者： Adam Conroy Helen Titley Rabi Rivett Xiangbo Feng John Methven Kevin Hodges Alan Brammer Andrew Burton Paromita chakraborty Guomin Chen Levi Cowan Jason Dunion abhijit Sarkar Bureau of Meteorology West PerthAustralia Met Office ExeterUK National Centre for Atmospheric Science and Department of Meteorology University of ReadingReadingUK Department of Meteorology University of ReadingReadingUK Cooperative Institute for Research in the Atmosphere Colorado State UniversityFort CollinsUSA National Centre for Medium Range Weather Forecasting NoidaIndia Shanghai Typhoon Institute of China Meteorological Administration ShanghaiChina Joint Typhoon Warning Center HonoluluUSA Cooperative Institute for Marine and Atmospheric Studies University of Miamiand Hurricane Research DivisionNOAA/Atlantic Oceanographic and Meteorological LaboratoryMiamiUSA

In this paper,we summarize findings from the Tenth International Workshop on Tropical Cyclones(IWTC-10)subgroup on operational track forecasting techniques and *** rate of improvement in the accuracy of official forecast tracks(OFTs)appears to be slowing down,at least for shorter lead times,where we may be approaching theoretical *** agencies continue to use consensus methods to produce the OFT with most continuing to rely on an unweighted consensus of four to nine NWP *** continues to be limited use of weighted consensus techniques,which is likely a result of the skills and additional maintenance needed to support this *** in the accuracy of ensemble mean tracks is leading to increased use of ensemble means in consensus *** agencies are increasingly producing situation-dependent depictions of track uncertainty,rather than relying on a static depiction of track forecast certainty based on accuracy statistics from the preceding 5 *** trend has been facilitated by the greater availability of ensemble NWP guidance,particularly vortex parameter files,and improved spread in *** improving spread-skill relationships,most ensemble NWP systems remain under *** many operational centers are looking to leverage“super-ensembles”(ensembles of ensembles)to ensure the full spread of location probability is *** is an important area of service development for multi-hazard impact-based warnings as it supports better decision making by emergency managers and the community in the face of uncertainty.©2023 The Shanghai Typhoon Institute of China Meteorological *** services by Elsevier *** behalf of KeAi Communication *** is an open access article under the CC BY-NC-ND license(http://***/licenses/by-nc-nd/4.0/).

关键词： Tropical cyclones Track forecasting Ensembles Track uncertainty

A Brief Review on Fundamentals of Conductive Polymer(CPs)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Organic Polymer Material Research 2022年第1期4卷 1-11页

作者： Subhadeep chakraborty Rahul Chatterjee abhijit Bandyopadhyay Department of Polymer Science and Technology University of Calcutta92A.P.C.RoadCalcutta700009India

Polymers are huge compounds made up of numerous monomers(repeated subunits).They have similar macro and micro properties,as well as electrical transport qualities,semiconductive capabilities,and optical *** the advent of conductive polyacetylene,conductive polymers have gotten a lot of *** conductors have a wide range of electrical conductivity,which may be produced by doping,while being mechanically flexible and having a high thermal *** may be created using a variety of methods,including chemical and electrochemical *** advancement in material stability and greater property control,an increasing variety of new applications are now being investigated.

关键词： Polymers Conducting Synthesis Optical properties Structures