检索结果-南通市图书馆

Trace fossil evidences of an Early Miocene paleoseismic event and depositional regime change from the Kutch(Kachchh) Basin

引用

Journal of Palaeogeography 2024年第1期13卷 165-180页

作者： Ayush Srivastava sudipta dasgupta Krishanu Chatterjee Mohuli das Bombay Ichnos Research Group Department of Earth SciencesIndian Institute of Technology Bombay(lIT Bombay)PowaiMumbaiMaharashtra400076India

Unconsolidated siliciclastic sediments can undergo post-burial deformation, which leads to the formation of distinctive sedimentary structures, known as soft-sediment deformation structures(SSDS). The presence of a series of sand volcanoes confined to a particular lithostratigraphic horizon can represent a paleoseismic activity and, thereby, exemplifies the concept of “seismite”. The Kutch Basin has been a tectonically active region since the initiation of eastern Gondwana rifting followed by a tectonic inversion during the Cenozoic due to the collision of the Indian and Eurasian plates. A stratum-bound series of sand volcanoes belonging to the Khari Nadi Formation(KNF) is exposed along the banks of Khari River. They separate the shallow marine deposits below and non-marine deposits above with their characteristic marine and paleosol trace fossil suites, respectively. Although a seismogenic origin has been much debated for the SSDS,the ichnofabric analysis of the sand-volcano-bearing stratum unequivocally points toward such an origin under a shallow seafloor condition. In addition to the sedimentary regime change from an open shallow-marine setting to a continental depositional environment concomitant with basinal uplift, the behavior of the burrowing crustaceans testifies to a syn-depositional development of a fault network associated with the fluidization, sand volcanism, and the resilience of the trace-producers in surviving those processes until the sedimentary regime change in the overlying strata. Although the ichno-sedimentological evidence apparently differs from the previous works that proposed a continuous base-level rise from the beginning of deposition of the Khari Nadi Formation up to the middle part of the overlying Chhasra Formation, the paleoseismic activity,its ichnologic signature, and the depositional regime change refer to a higher-resolution(i.e., lower-order)sequence-stratigraphic change causing a short-duration regression within a longer-durat

关键词： Sand volcano Seismite Ichnology Khari Nadi Formation Kutch Basin Kachchh Basin

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A new parametrization of dark energy equation of state leading to double exponential potential

引用

Research in Astronomy and Astrophysics 2018年第11期18卷 1-10页

作者： sudipta das Abdulla Al Mamon Manisha Banerjee Department of Physics Visva-Bharati Department of Mathematics Jadavpur University

We show that a phenomenological form of energy density for the scalar field can provide the required transition from decelerated(q > 0) to accelerated expansion(q < 0) phase of the *** have used the latest type Ia supernova(SNIa) and Hubble parameter datasets to constrain the model parameters. The best fit values obtained from those datasets are then applied to reconstruct ωφ(z), the equation of state parameter for the scalar field. The results show that the reconstructed forms of q(z) and ωφ(z) do not differ much from the standard ΛCDM value at the current epoch. Finally, the functional form of the relevant potential V(φ) is derived by a parametric reconstruction. The corresponding V(φ)comes out to be a double exponential potential, which has a number of cosmological ***, we have also studied the effect of this particular scalar field dark energy sector on the evolution of matter overdensities.

关键词： cosmic acceleration quintessence field dark energy density perturbation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Visible Light Excitable SCN^- Selective Fluorescence Probe Derived from Thiophene

引用

Chinese Journal of Chemistry 2015年第10期33卷 1173-1177页

作者： sudipta das Sisir Lohar Jesus Sanmartin Matalobos Debasis das Department of Chemistry The University of Burdwan Burdwan 713104 West Bengal India Departamento de Qu'tmicalnorg'anica Facultade de Qutmica Avda. Das Ciencias s/n 15782 Santiago de Compostela Spain

An efficient fluorescence probe, 4-methyl-2,6-bis（（thiophen-2-ylmethylimino）methyl）phenol （DFPTMA） and its SCN adduct has been synthesized and characterized by different spectroscopic techniques like ^1H NMR,^13C NMR, QTOF-MS ES^＋, UV-Vis and FTIR spectroscopy. Single crystal X-ray structure of DFPTMA is reported. In presence of SCN-, DFPTMA exhibits significant fluorescence enhancement （λEx, 455 nm, λEm, 504 nm） in aqueous methanol （water-methanol, 1 ： 4, V/V, 0.1 mol/L HEPES buffer, pH 7.4）. Common bio-relevant anions viz. CH3COO^-, NO2, NO7, Cl^-, Br^-, I^-, SO4^2-, HSO4^-, N3^-, HAsO4^2-, Cr2O7^2-, H2PO4, ClO4^-, NCO^-, CN^-, CO3^2-, F^-, PO4^3-, S2-, HS- do not interfere in the recognition of SCN-. Lowest detection limit for SCN^- is 0.88 μmol/L with response time 〈5 min. The SCN assisted enhancement in emission intensity may be attributed to the formation of H-bond which enhances the rigidity of the molecular assembly.

关键词： visible light excitation SCN^- fluorescence thiophene derivative

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Tree species composition and diversity in montane forests of Garhwal Himalaya in relation to environmental and soil properties

引用

Journal of Mountain Science 2020年第12期17卷 3097-3111页

作者： Dinesh Singh RAWAT P.TIWARI sudipta Kumar das J.K.TIWARI Department of Botany&Microbiology HNB Garhwal UniversitySrinagar(Garhwal)-246174UttarakhandIndia Central National Herbarium Botanical Survey of IndiaHowrah-711103West BengalIndia

The montane forests of Garhwal Himalaya were investigated for tree species composition and diversity in relation to environmental and edaphic variables.A stratified random sampling approach was adopted to collect the field data from each forest.A total of 39 tree species belonging to 31 genera and 23 families were recorded from the sampling area(6 forest stands ×10 plots in each).Lauraceae with 5 species was the largest family while Quercus(4 species) emerged as the largest ***-area curve(asymptote) predicted more species than the observed number of *** analysis has shown that the two Abies pindrow dominant forest stands had the highest similarity in tree species *** tree stem density ranged from 540-1170 ha-1,basal area 23.01-55.94 m^2 ha-1,ShannonWiener diversity index 1.69-2.49,evenness index0.42-0.74,beta diversity 0.40-0.82 and similarity index 0.17-0.54 in the six studied ***-way indicator species analysis(TWINSPAN) identified four distinct tree communities in the study area with Daphniphyllum himalayense,Abies pindrow,Quercus oblongata,and Pinus roxburghii as indicator species of corresponding *** correspondence analysis(CCA) ascertained the TWINSPAN results and revealed the relation of tree species with environmental and edaphic *** phytosociological attributes of tree species varied from one forest stand to another;however,the tree species richness,density,and diversity peaked at intermediate elevation on the north *** reveal that tree composition and diversity in the montane forests of Garhwal Himalaya are influenced by both environmental(elevation and slope aspect)and soil variables(texture,water holding capacity,moisture content,available N,exchangeable P,and pH).This study will help in understanding the forest distribution across the western Himalaya,guiding the conservationists and policymakers in carrying out conservation-related management activities,designing the long-

关键词： Diversity Tree species Montane forests Soil properties Western Himalaya

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Green Degumming of Silk by Enzyme Extracted from Natural Sources

引用

Journal of Materials Science and Chemical Engineering 2020年第8期8卷 30-40页

作者： Mahbubur Rahman Asim Bhowmik sudipta das Kartick Chowhan Tanmoy Biswas Department of Textile Engineering Mawlana Bhashani Science and Technology University Tangail Bangladesh

The main objective of this work is to degum the silk with natural enzyme in lieu of conventional degumming to make it sustainable. Fibroin and sericin are the main composition of silk. Sericin provides a harsh and stiff effect of silk and decreases the valuable property like luster and whiteness and also leads to uneven dyeing. It is necessary to remove this sericin for the better post processing of silk. The removal process of sericin from silk is called degumming. Usually degumming process is done by using chemicals like soda (Na2CO3), detergent and other chemical staffs. But these chemicals are lethal to the environment. So, if such component found that can be substitute the fatal components and give the same required result or very close then that would be considered as an asset. This work deals with the different enzymes extracted from natural sources such as papaya skin, pineapple skin and guava leaf with variation of enzyme concentrations such as 10 (%), 15 (%) & 20 (%) as well as 35°C 45°C & 55°C temperatures that influence the degumming efficiency. By analyzing the various samples on the basis of degumming efficiency and other tests such as tensile strength, water vapor permeability, pilling and abrasion, crease recovery, whiteness test and spot test are done by standard method, it is found that the enzyme extracted from papaya skin shows the best degumming efficiency 15.9 (%) and other tests also show the good result at 15 (%) concentration and 45°C temperature whereas degumming efficiency 16.6 (%) for conventional process. From this work, it can be concluded that enzyme extracted from papaya skin can be substituted of conventional degumming which is also ecofriendly.

关键词： Degumming Silk Enzyme Pineapple Skin Ecofriendly

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

On chip chiral and plasmonic hybrid dimer or tetramer:Generic way to reverse longitudinal and lateral optical binding forces

引用

Chinese Physics B 2022年第5期31卷 305-316页

作者： sudipta Biswas Roksana Khanam Rumi Tasnia Rahman Raima Saikat Chandra das M R C Mahdy Department of Electrical&Computer Engineering North South UniversityBashundharaDhaka1229Bangladesh

For both the longitudinal binding force and the lateral binding force,a generic way of controlling the mutual attraction and repulsion(usually referred to as reversal of optical binding force)between chiral and plasmonic hybrid dimers or tetramers has not been reported so *** this paper,by using a simple plane wave and an onchip configuration,we propose a possible generic way to control the binding force for such hybrid objects in both the near-field region and the far-field *** also investigate different inter-particle distances while varying the wavelengths of light for each inter-particle distance throughout the *** of all,for the case of longitudinal binding force,we find that chiral-plasmonic hybrid dimer pairs do not exhibit any reversal of optical binding force in the near-field region nor in the far-field region when the wavelength of light is varied in an air ***,when the same hybrid system of nanoparticles is placed over a plasmonic substrate,a possible chip,it is possible to achieve a reversal of the longitudinal optical binding ***,for the case of lateral optical binding force,we investigate a setup where we place the chiral and plasmonic tetramers on a plasmonic substrate by using two chiral nanoparticles and two plasmonic nanoparticles,with the setup illuminated by a circularly polarized plane *** applying the left-handed and the right-handed circular polarization state of light,we also observe the near-field and the far-field reversal of lateral optical binding force for both *** far as we know,so far,no work has been reported in the literature on the generic way of reversing the longitudinal optical binding force and the lateral optical binding force of such hybrid *** a generic way of controlling optical binding forces can have important applications in different fields of science and technology in the near future.

关键词： longitudinal binding force plasmonics chirality optical force

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

天然橡胶-聚苯乙烯互穿网络——形态和机械性能

引用

橡胶参考资料 1994年第2期24卷 40-44页

作者： Bibekananda das sudipta Sinha Tanmoy Gangopadhyay 王怀宇

1 前言近年来,人们对互穿网络聚合物(IPN)产生了极大的兴趣。IPN 是一类新型网络形式的聚合物共混体,在其他组分直接存在的情况下,其中至少有一个组分被聚合和/或交联,合成 IPN 是两交联聚合物紧密共混的唯一方法,并且具有独特的综合性能。

关键词：天然橡胶聚苯乙烯互穿网络性能

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：