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Evaluating the hydrocarbon generation potential of the Paleocene–Eocene carbonaceous rocks in the Barmer and Bikaner-Nagaur Basins, western Rajasthan, India

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China Geology 2025年第1期8卷 77-91页

作者： Alok Kumar Khairul Azlan Mustapha Alok K.Singh Mohammed Hail Hakimi Ali Y.Kahal Waqas Naseem Hijaz Kamal Hasnan Department of Geology Faculty of ScienceUniversiti MalayaKuala Lumpur 50603Malaysia Department of Geology Institute of ScienceBanaras Hindu UniversityVaranasi 221005India Department of Petroleum Engineering and GeoEngineering Rajiv Gandhi Institute of Petroleum TechnologyJais 229304India Institute of Geology and Petroleum Technologies Kazan Federal UniversityKazan 420008Russia Geology and Geophysics Department King Saud UniversityRiyadh 11451Saudi Arabia Department of Geology University of PoonchRawalakot 12350Pakistan

The Bikaner-Nagaur and Barmer Basins(Rajasthan)are the most important petroliferous sedimentary basins in *** over a decade,the exploration and extraction of hydrocarbons in these ***-Eocene age rocks bear organic-rich sediments in these basins,including lignite and carbonaceous shale *** present research investigates the source rock properties,petroleum potential and thermal maturity of the carbonaceous shale partings from the lignite mines of Gurha(Bikaner-Nagaur Basin)and Kapurdi(Barmer Basin)using petrographical and geochemical *** carbonaceous shales have high organic matter(OM),with considerable total organic carbon(TOC)contents ranging from 13%to 39%.Furthermore,they contain hydrogen-rich kerogen,including types II and II/III,as evidenced by the Rock-Eval and elemental analysis *** existence of these kerogen types indicates the abundance of reactive(vitrinite and liptinite)***,the carbonaceous shales from the Bikaner–Nagaur Basin have oil generation potentials,with a high hydrogen index(up to 516 mg HC/g TOC)and a H/C ratio(up to 1.5)along with a significant presence of oil-prone liptinitic *** from the geochemical and petrological results,the studied shales have low huminite reflectance(0.31%–0.48%),maximum temperature(S_(2) peak;Tmax)between 419℃ and 429℃,and low production index values(PI:0.01–0.03).These results indicate that these carbonaceous shales contain immature OM,and thereby,they cannot yet release commercial amount of *** immaturity level in the studied outcrop section is due to the shallow burial *** proxies further indicate the presence of both oil and gas-prone source rocks.

关键词： Carbonaceous shale Petroliferous Bikaner-Nagaur Basin Barmer Basin High hydrogen index Hydrogen-rich kerogen Western Rajasthan Geochemistry Petrology

Unveiling urbanization effects on trees outside forests along the urban-rural gradient in megacity Bengaluru

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Forest Ecosystems 2025年第01期 56-65页

作者： Tao Jiang Maximilian Freudenberg Christoph Kleinn V.P.Tewari B.N.Diwakara Nils N?lke Forest Inventory and Remote Sensing Department Faculty of Forest Sciences and Forest Ecology University of G?ttingen Himalayan Forest Research Institute ICFRE Institute of Wood Science and Technology IWST

Rapid urbanization has caused significant changes along the urban-rural gradient, leading to a variety of landscapes that are mainly shaped by human activities. This dynamic interplay also influences the distribution and characteristics of trees outside forests(TOF). Understanding the pattern of these trees will support informed decision-making in urban planning, in conservation strategies, and altogether in sustainable land management practices in the urban context. In this study, we employed a deep learning-based object detection model and high resolution satellite imagery to identify 1.3 million trees with bounding boxes within a 250 km2research transect spanning the urban-rural gradient of Bengaluru, a megacity in Southern India. Additionally, we developed an allometric equation to estimate diameter at breast height(DBH) from the tree crown diameter(CD) derived from the detected bounding boxes. Our study focused on analyzing variations in tree density and tree size along this gradient. The findings revealed distinct patterns: the urban domain displayed larger tree crown diameters(mean:8.87 m) and DBH(mean: 43.78 cm) but having relatively low tree density(32 trees per hectare). Furthermore,with increasing distance from the city center, tree density increased, while the mean tree crown diameter and mean tree basal area decreased, showing clear differences of tree density and size between the urban and rural domains in Bengaluru. This study offers an efficient methodology that helps generating instructive insights into the dynamics of TOF along the urban-rural gradient. This may inform urban planning and management strategies for enhancing green infrastructure and biodiversity conservation in rapidly urbanizing cities like Bengaluru.

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Capillary-gravity ship wave patterns

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Journal of Hydrodynamics 2017年第5期29卷 825-830页

作者： Hui Liang Xiaobo Chen Deepwater Technology Research Centre(DTRC) Bureau VeritasSingapore College of Shipbuilding Engineering Harbin Engineering UniversityHarbin 150001China

Ship wave pattern is a fascinating research topic in the fields of marine hydrodynamics and water waves. Within the pure-gravity wave theory, the ship wave pattern composed of transverse waves and divergent waves appearing on the downstream is confined within a sector symmetrical about the ship track with a half-angle 19°28＇. However, when the surface tension is accounted for, the wave pattern is greatly modified especially at a low translating speed. Besides the minimum speed of capillary waves c_（min）= 0.23 m/s below which waves cannot be generated, there is another critical speed c_（div）= 0.45 m/s associated with the disappearance of divergent waves. In the present paper, the wave patterns created by a steadily translating source are studied, and they are examined with the crestlines obtained from the asymptotic analysis.

关键词： Ship waves wave pattern gravity-dominant waves capillarity-dominant waves

Self-centering seismic retrofit scheme for reinforced concrete frame structures:SDOF system study

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Earthquake Engineering and Engineering Vibration 2010年第2期9卷 271-283页

作者： Yunfeng Zhang and Xiaobin Hu Department of Civil and Environmental Engineering,University of Maryland,College Park,MD 20742,USA Department of Civil and Environmental Engineering University of Maryland College Park 20742 USA

This paper presents the results of a parametric study of self-centering seismic retrofit schemes for reinforced concrete (RC) frame buildings. The self-centering retrofit system features flag-shaped hysteresis and minimal residual deformation. For comparison purpose,an alternate seismic retrofit scheme that uses a bilinear-hysteresis retrofit system such as buckling-restrained braces (BRB) is also considered in this paper. The parametric study was carried out in a single-degree-of-freedom (SDOF) system framework since a multi-story building structure may be idealized as an equivalent SDOF system and investigation of the performance of this equivalent SDOF system can provide insight into the seismic response of the multi-story building. A peak-oriented hysteresis model which can consider the strength and stiffness degradation is used to describe the hysteretic behavior of RC structures. The parametric study involves two key parameters -the strength ratio and elastic stiffness ratio between the seismic retrofit system and the original RC frame. An ensemble of 172 earthquake ground motion records scaled to the design basis earthquake in California with a probability of exceedance of 10% in 50 years was constructed for the simulation-based parametric study. The effectiveness of the two seismic retrofit schemes considered in this study is evaluated in terms of peak displacement ratio,peak acceleration ratio,energy dissipation demand ratio and residual displacement ratio between the SDOF systems with and without retrofit. It is found from this parametric study that RC structures retrofitted with the self-centering retrofit scheme (SCRS) can achieve a seismic performance level comparable to the bilinear-hysteresis retrofit scheme (BHRS) in terms of peak displacement and energy dissipation demand ratio while having negligible residual displacement after earthquake.

关键词： earthquake reinforced concrete frame structure nonlinear analysis SDOF system seismic retrofit self-centering

A Novel Approach to Clustering Merchandise Records

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Journal of Computer Science & Technology 2007年第2期22卷 228-231页

作者：程涛远王珊 School of Information Renmin University of China Beijing 100872 China

Object identification is one of the major challenges in integrating data from multiple information sources. Since being short of global identifiers, it is hard to find all records referring to the same object in an integrated database. Traditional object identification techniques tend to use character-based or vector space model-based similarity computing in judging, but they cannot work well in merchandise databases. This paper brings forward a new approach to object identification. first, we use merchandise images to judge whether two records belong to the same object; then, we use Naive Bayesian Model to judge whether two merchandise names have similar meaning. We do experiments on data downloaded from shopping websites, and the results show good performance.

关键词： object identification data cleaning data integration

AN ERROR ANALYSIS METHOD SPP-BEAM AND A CONSTRUCTION GUIDELINE OF NONCONFORMING FINITE ELEMENTS FOR FOURTH ORDER ELLIPTIC PROBLEMS

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Journal of Computational Mathematics 2020年第1期38卷 195-222页

作者： Jun Hu Shangyou Zhang LMAM and School of Mathematical Sciences Peking UniversityBeijing 100871China Department of Mathematical Sciences University of DelawareNewarkDE 19716USA

Under two hypotheses of nonconforming finite elements of fourth order elliptic problems,we present a side-patchwise projection based error analysis method(SPP-BEAM for short).Such a method is able to avoid both the regularity condition of exact solutions in the classical error analysis method and the complicated bubble function technique in the recent medius error analysis *** addition,it is universal enough to admit ***,we propose a sufficient condition for these hypotheses by imposing a set of in some sense necessary degrees of freedom of the shape function *** an application,we use the theory to design a P3 second order triangular H2 non-conforming element by enriching two P4 bubble functions and,another P4 second order triangular H2 nonconforming finite element,and a P3 second order tetrahedral H2 non-conforming element by enriching eight P4 bubble functions,adding some more degrees of freedom.

关键词： Nonconforming finite element A priori error analysis Biharmonic equation

Structural optimization of elliptical-tip star propellant grain using sub-problem approximation

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航空动力学报 2012年第2期27卷 457-464页

作者： Muhammad Adnan SUN Bing ZHANG Jian-wei Ali Sarosh School of Astronautics Beijing University of Aeronautics and AstronauticsBeijing 100191China

A method is presented here for structural optimization of elliptical-tip star *** grain structural integrity was improved by minimizing the most critical area of inner bore hoop strain during cool *** was done by sub-problem approximation method in conjunction with finite element *** radii of the ellipse were varied during optimization to find the optimal *** optimization resulted in grain geometry having minimum level of Inner bore hoop strain without violating the preset limits of burning *** von mises strain at grain inner bore was also reduced in resultant grain.

关键词： solid propellant grain star grain viscoelastic analysis structure optimization sub-problem approximation

On the Supercyclicity and Hypercyclicity of the Operator Algebra

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Acta Mathematica Sinica,English Series 2008年第7期24卷 1221-1232页

作者： B.YOUSEFI H.REZAEI Department of Mathematics College of SciencesShiraz UniversityShiraz 71454Iran and Department of MathematicsPayame-Noor UniversityIran

Let B（X） be the operator algebra for a separable infinite dimensional Hilbert space H, endowed with the strong operator topology or ＊-strong topology. We give sufficient conditions for a continuous linear mapping L ： B（X） →B（X） to be supercyclic or ,-supercyclic. In particular our condition implies the existence of an infinite dimensional subspace of supercyclic vectors for a mapping T on H. Hypercyclicity of the operator algebra with strong operator topology was studied＇ by Chan and here we obtain an analogous result in the case of ＊-strong operator topology.

关键词： operator algebra,*-strong topology strong operator topology hypercyclicity criterion supercyclicity criterion

On ASGS framework:general requirements and an example of implementation

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第4期8卷 511-521页

作者： KULESZA Kamil KOTULSKI Zbigniew Department of Applied Mathematics and Theoretical Physics University of CambridgeCambridge CB3 0WAUK Institute of Fundamental Technological ResearchPolish Academy of SciencesWarsaw 00-049Poland Institute of Fundamental Technological Research Polish Academy of SciencesWarsaw 00-049Poland

In the paper we propose a general, abstract framework for Automatic Secret Generation and Sharing (ASGS) that should be independent of underlying Secret Sharing Scheme (SSS). ASGS allows to prevent the Dealer from knowing the secret. The Basic Property Conjecture (BPC) forms the base of the framework. Due to the level of abstraction, results are portable into the realm of quantum computing. Two situations are discussed. first concerns simultaneous generation and sharing of the random, prior nonexistent secret. Such a secret remains unknown until it is reconstructed. Next, we propose the framework for automatic sharing of a known secret. In this case the Dealer does not know the secret and the secret Owner does not know the shares. We present opportunities for joining ASGS with other extended capabilities, with special emphasis on PVSS and pre-positioned secret sharing. Finally, we illustrate framework with practical implementation.

关键词： Secret sharing Security protocols Dependable systems Authentication management