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中泰彩色宝石参考价格体系建设及使用标准

中国宝石 2024年第2期 192-195页

作者：史洪岳(文/图) Chomphol Phornchindarak(文/图) 陆太进(文/图) 李崇杰(文/图) hemant kumar jain(文/图) 杨君怡(文/图) Napat Quintero(文/图) 不详

近年来,随着彩色宝石需求增长,市场供应不稳定,高品质且热门的彩色宝石价格呈现指数级增长,价格的波动幅度或将成为“后疫情时代”影响这一行业发展的重要因素之一。中国是彩色宝石主要消费市场,而泰国是主要加工和交易中心,两国彩色宝... 详细信息

近年来,随着彩色宝石需求增长,市场供应不稳定,高品质且热门的彩色宝石价格呈现指数级增长,价格的波动幅度或将成为“后疫情时代”影响这一行业发展的重要因素之一。中国是彩色宝石主要消费市场,而泰国是主要加工和交易中心,两国彩色宝石行业主要的业界团体积极响应“一带一路”倡议,展开合作。

关键词：彩色宝石交易中心一带一路参考价格体系消费市场市场供应波动幅度价格

Identification of EST–SSRs and molecular diversity analysis in Mentha piperita

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The Crop Journal 2015年第4期3卷 335-342页

作者： Birendra kumar Umesh kumar hemant kumar Yadav CSIR-Central Institute of Medicinal and Aromatic Plant Sciences P.O.CIMAP Near Kukrail Picnic Spot CSIR-National Botanical Research Institute Rana Pratap Marg Academy of Scientific and Innovative Research (AcSIR)

EST sequences of Mentha piperita available in the public domain(NCBI) were exploited to develop SSR markers. A total of 1316 ESTs were assembled into 155 contigs and 653 singletons and of these, 110 sequences were found to contain 130 SSRs, with a frequency of1 SSR/3.4 kb. Dinucleotide repeat SSRs were most frequent(72.3%) with the AG/CT(43.8%)repeat motif followed by AT/AT(16.2%). Primers were successfully designed for 68SSR-containing sequences(62.0%). The 68 primers amplified 13 accessions of M. piperita and 54 produced clear amplicons of the expected size. Of these 54, 33(61%) were found to be polymorphic among M. piperita accessions, showing from 2 to 4 alleles with an average of2.33 alleles/SSR, and the polymorphic information content(PIC) value varied between 0.13 and 0.51(average 0.25). All the amplified SSRs showed transferability among four different species of Mentha, with a highest in Mentha arvensis(87.0%) and minimum in Mentha citrata(37.0%). The newly developed SSRs markers were found to be useful for diversity analysis, as they successfully differentiated among species and accessions of Mentha.

关键词： EST–SSRs Genetic diversity Mentha piperita Polymorphic information content Transferability

Recharge and vulnerability assessment of groundwater resources in North west India:Insights from isotope-geospatial modelling approach

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Geoscience Frontiers 2024年第1期15卷 247-262页

作者： Annadasankar Roy Sitangshu Chatterjee Uday kumar Sinha Anil kumar jain hemant Mohokar Ajay Jaryal Tirumalesh Keesari Harish Jagat Pant Isotope and Radiation Application Division Bhabha Atomic Research CentreTrombayMumbai–400085India Homi Bhabha National Institute Mumbai 400094India Central Ground Water Board AhmedabadGujaratIndia

Recent studies indicate dwindling groundwater quantity and quality of the largest regional aquifer system in North West India,raising concern over freshwater availability to about 182 million population residing in this *** agricultural activities have resulted severe groundwater pollution in this area,demanding a systematic vulnerability assessment for proactive *** vulnerability assessment models encounter drawbacks due to subjectivity,complexity,data-prerequisites,and spatial-temporal *** study incorporates isotopic information into a weighted-overlay framework to overcome the above-mentioned limitations and proposes a novel vulnerability assessment *** isotope methodology provides crucial insights on groundwater recharge mechanisms(18O and 2H)and dynamics(3H)-often ignored in vulnerability *** characterisation of precipitation helped in establishing Local Meteoric Water Line(LMWL)as well as inferring contrasting recharge mechanisms operating in different *** aquifer(depth<60 m)showed significant evaporative signature with evaporation loss accounting up to 18.04%based on Rayleigh distillation ***-aquifer connections were apparent from Kernel Density Estimate(KDE)and isotope correlations.A weighted overlay isotope-geospatial model was developed combining 18O,3H,aquifer permeability,and water level *** central and northern parts of study area fall under least(0.29%)and extremely(1.79%)vulnerable zones respectively,while majority of the study area fall under moderate(42.71%)and highly vulnerable zones(55.20%).Model validation was performed using groundwater NO3-concentration,which showed an overall accuracy up to 82%.Monte Carlo Simulation(MCS)was performed for sensitivity analysis and permeability was found to be the most sensitive input parameter,followed by 3H,18O,and water *** the vulnerability map with Land Use Land Cover(LULC)and population density maps

关键词： Agricultural pollution Data scarcity Recharge mechanism Rayleigh distillation Isotope-geospatial model Vulnerability assessment

Design of crown pillar thickness using finite element method and multivariate regression analysis

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International Journal of Mining Science and Technology 2017年第6期27卷 955-964页

作者： kumar hemant Deb Debasis Chakravarty D. Department of Mining Engineering Indian Institute of Technology (Indian School of Mines) Dhanbad 826004 India Department of Mining Engineering Indian Institute of Technology Kharagpur 721302 India

Minerals are now being extracted from deep mines due to drying up of resource in shallow ground. The need for suitable supports and ground control mechanisms for safe mining necessitates proper pillar design with filling technology. In addition, high horizontal stress may cause collapse of hanging wall and footwall rocks, hence designing of suitable crown pillars is absolutely necessary for imposing overall safety of the stopes. This paper provides a methodology for the evaluation of the required thickness of crown pillars for safe operation at depth ranging from 600 m to 1000 m. Analyses are conducted with the results of 108 non-linear numerical models considering Drucker-Prager material model in plane strain condition. Material properties of ore body rock and thickness of crown pillars are varied and safety factors of pillars estimated. Then, a generalized statistical relationship between the safety factors of crown pillars with the various input parameters is developed. The developed multivariate regression model is utilized for generating design/stability charts of pillars for different geo-mining *** design charts can be used for the design of crown pillar thickness with the depth of the working,taking into account the changes of the rock mass conditions in underground metal mine.

关键词： Cut and fill mining Crown pillar FEM Regression model Design chart

Understanding pore characteristics through core-based petrographic and petrophysical analysis in a heterogeneous carbonate reservoir:A case study from the Mumbai Offshore Basin,India

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Petroleum Research 2023年第4期8卷 469-480页

作者： Ilius Mondal kumar hemant Singh Department of Earth Science Indian Institute of TechnologyBombayIndia

Carbonate rocks exhibit complex and heterogeneous pore structures;such heterogeneity is manifested by the occurrence of a wide variety of pore types with different sizes and geometries as a result of depositional and diagenetic *** complications substantially increase the uncertainty of predicted rock hydraulic parameters because samples with comparable porosities might have very different permeability *** this study,small-scale characterisation of porosity and permeability in heterogeneous Eocene limestone samples from the Bassein Formation of the B-X structure of the MK Field in Mumbai Offshore Basin,India,was carried out,employing an integrated framework that in-corporates thin-section petrography,routine core analysis,mercury injection capillary pressure and nuclear magnetic resonance *** pore characteristics of these carbonates range from poor to *** studied samples exhibited large ranges of porosity,permeability and other associated petrophysical *** pore types,as well as their orientations and connectivity,are the primary factors causing the *** of the complexity of the pore networks,a simple lithofacies classification alone would have been insufficient to link porosity and *** reservoir char-acteristics in the study area are strongly linked to the development and/or destruction of reservoir porosity-permeability during different phases of ***-four carbonate core samples from the limestone unit were studied and classified into microfacies and pore type classes,producing an accurate assessment of reservoir *** comprehensive workflow incorporates the pore volume distributions and pore throat attributes for each rock *** carbonate microfacies were identified by petrographic analysis and their petrophysical characteristics,such as porosity,permeability,pore throat size,pore volume and fluid flow factors,were *** study demonstrates how macro-porosity

关键词： Carbonatereservoir Permeability Mercury injection capillary pressure Nuclear magnetic resonance Porosity partitioning

Fluid substitution in NMR T_(2)distribution and resistivity independent saturation computation using synthetic capillary pressure data

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Petroleum Research 2023年第1期8卷 77-86页

作者： Ilius Mondal kumar hemant Singh Department of Earth Science Indian Institute of Technology BombayIndia

Petrophysicists and reservoir engineers utilise the capillary pressure and saturation-height function for calculating the water saturation of any reservoir,at a given height above the free water *** results have a big impact on reserve *** majority of capillary pressure studies are carried out in labs with core ***,on the other hand,are usually altered from their original state before being delivered to ***,the accuracy of discrete sets of core data in describing entire reservoir parameters,is still up for *** of the capillary pressure curve in reservoir condition is an important subject that is challenging to *** use of nuclear magnetic resonance(NMR)logs for oil and gas exploration has grown in popularity over the last few ***,most of the time the utilization of the data is limited for evaluating porosity-permeability,distributions and computation of irreducible water *** the advent of fluid substitution methods,NMR T_(2)distributions may now be used to synthesize core equivalent capillary pressure *** fluid substitution workflow,our study introduces a better approach for obtaining capillary pressure curves from the NMR T_(2)*** available core data has been used to calculate calibration parameters for better saturation height *** workflow introduces a novel approach in resistivity independent saturation *** the exploratory wells of our study area,computed water saturation derived from the saturation height function exhibits encouraging agreement with resistivity based water saturation from multi-mineral *** NMR based saturation height modelling approach has been included in study area for the first time so far.

关键词： Carbonate reservoir NMR fluid Substitution Capillary pressure Saturation height function Resistivity independent saturation

Grid Tied Solar PV System with Power Quality Enhancement Using Adaptive Generalized Maximum Versoria Criterion

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CSEE Journal of Power and Energy Systems 2023年第2期9卷 722-732页

作者： Manoj Badoni Alka Singh Ankit kumar Singh hemant Saxena Rajeev kumar Delhi Technological University Delhi 110042India.A.K.Singh is with Netaji Subhas University of TechnologyDelhi 110078India Netaji Subhas University of Technology Delhi 110078India Electrical and Electronics Engineering Department KIET Group of InstitutionsGhaziabadIndia Electrical Engineering Department Jamia Millia IslamiaNew DelhiIndia

A three phase grid tied solar photovoltaic(PV)system with power quality compensation features is presented in this *** system is used to transfer power generated from a solar PV array to feed linear and nonlinear loads along with compensation for several power quality(PQ)issues,such as harmonics,redundant reactive power and load *** generated DC power from the PV array is converted into AC by implementing a three-phase voltage source converter(VSC).In order to transfer active power and mitigate PQ problems,an efficient control technique is required for the grid tied solar PV *** study presents the use of an adaptive generalized maximum Versoria criterion(AGMVC)controller for VSC used in a solar PV energy conversion *** utilization of the solar PV array is accomplished by using the Perturb and Observe based maximum power point tracking(MPPT)*** experimental setup of the grid integrated PV system is implemented in the laboratory using an IGBT based VSC and DSP(dSPACE DS-1202).The performance of the AGMVC control technique is verified experimentally using laboratory *** control technique is compared with different conventional controllers,such as synchronous reference frame theory(SRFT)and instantaneous reactive power theory(IRPT)along with recently developed weight-based controllers viz.,least mean square(LMS),least mean mixed norm(LMMN)and normalized kernel least mean fourth-neural network(NKLMFNN).Numerous terms,such as fundamental weight convergence,steady state error,computational complexity,phase lock loop(PLL)requirement and harmonic compensation capability,are considered for comparison purposes of AGMVC with the above listed control *** system performance is verified according to the IEEE-519 standard.

关键词： Harmonics maximum versoria criterion power factor corection(PFC) solar photovoltaic

Impact of orientation of blast initiation on ground vibrations

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第1期15卷 255-261页

作者： Dayamoy Garai hemant Agrawal Arvind kumar Mishra Indian Institute of Technology(ISM) DhanbadIndia Central Mine Planning and Design Institute Limited RanchiIndia

The blast-induced ground vibrations can be significantly controlled by varying the location and orien-tation of point of interest from blast *** blast waves generated due to individual holes get super-imposed and resultant peak particle velocity(PPV)*** the orientation sequence of holes blasts on site,the superimposition angle of wave changes and hence results in significant variation in resultant *** orientation with respect to the initiation of blasts resulting in lowest PPV needs to be identified for any *** knowing the PPV contour of vibration waves in mine sites,it is possible to reduce the vibration on the structures by changing the initiation *** this paper,experimental blasts were conducted at two different mine sites and the PPV values were recorded at different ori-entations from the blast site and its initiation *** PPV contours were drawn to identify the orientation with least and highest PPV generation *** was found that by merely changing the initi-ation sequence of blasts with respect to the sensitive structure or point of interest,the PPV values can be reduced significantly up to 76.9%.

关键词： Peak particle velocity(PPV) Initiation orientation Wave superimposition Orientation of blast Blast initiation

Core-log integration and application of machine learning technique for better reservoir characterisation of Eocene carbonates,Indian offshore

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Energy Geoscience 2022年第1期3卷 49-62页

作者： Ilius Mondal kumar hemant Singh Indian Institute of Technology Bombay India

Rock types,pore structures and permeability are essential petrophysical outputs,and they contribute considerably to the highest degree of uncertainty in reservoir *** factors have a strong influence on exploration and field development *** analysis is the best approach for estimating permeability,assigning rock types and characterising pore *** logs are the most often employed method for estimating the parameters at each data point of reservoirs since there are more un-cored wells than cored *** intelligence,on the other hand,is gaining popularity in the geosciences due to the ever-increasing complexity and volume of available subsurface *** is also obvious in the demand for faster and more accurate interpretations in order to identify reservoir characteristics in increasingly difficult and complicated petroliferous *** Neural Networks and Self-Organizing Maps are examples of machine learning approaches that can be used in both supervised and unsupervised modes for modelling and *** carbonates of Mukta oilfield are the major pay rocks of strong geological heterogeneity in terms of their porosity and permeability relationship with pore *** paper outlines a novel method of rock fabric classification,pore structure characterization,flow unit classification and robust reservoir permeability modelling based on an integrated approach that incorporates core measurements,log data and machine learning *** pore structure has been characterised by the combination of conventional core,capillary pressure and nuclear magnetic resonance *** neural network has added an adequate benefit in accurate permeability modelling by utilizing the concepts of rock classifications and hydraulic flow units.

关键词： Permeability Microfacies MICP NMR Hydraulic flow unit Artificial neural network Reservoir characterisation