最新刊期
卷 54 ， 期 1 ， 2015
- 摘要：The model of image zooming based on fluid dynamics equation including convection term and diffusive term, have two ways of interpolation. The experimental results show the effective performance of the proposed model in image zooming.关键词：image zooming;Navier-Stokes equation;anisotropic diffusion;blocky affect
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发布时间：2023-12-11 - 摘要：The base space of the universal unfolding of isolated hypersurface singularities can be equipped with a geometry structure, which was atomizated by Hertling as CVstructures.Hertling also proved that this structure is compatible with the canonical Frobenius manifold on the base space and gave CDVstructure. Given any CDVstructure M,there are two natural flat meromorphic connections and on the pullback bundles of the complex tangent bundle H:=π*T(1,0)M, where π:?times;M→M，and the singularities of these two connections are subvarieties{0,∞}×M.If M is a semisimple Frobenius manifold, it is known that these two meromorphic connections have irregular singularities. It is concluded that there exists a formal isomorphism between these two formalized bundles with connections by applying the classifications of irregular flat meromorphic connections. A constructional proof of the formal isomorphism is given.关键词：Frobenius manifolds;tt*structures;CDVstructures;flat meromorphic connections;Poincare rank
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发布时间：2023-12-11 - 摘要：L1 regularization problem is a non-smooth unconstrained optimization problem,which is widely used in the fields such as variable selection,data compression and image processing. Optimality conditions for the solution of L1 regularization problem is given. And a MondWeir type dual problem for L1regularization problem is formulated, by using these optimal conditions. Finally a weak duality theorem and a strong duality theorem are proved.关键词：L1 regularization;optimality condition;dual problem
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发布时间：2023-12-11 - 摘要：Due to limited medical resources, vaccine immunization rates are not often constant. To adapt nonlinear pulse vaccination function, an SIR epidemic model with lifelong immunity and pulse vaccination is stablished. By using stroboscopic map and fixed point of difference equations, the existence of disease free periodic solution in the model is discussed. The global asymptotically stability of disease free periodic solution is proved by applying Floquet multiplier theory and differential pulse comparison theorem. By choosing the pulse vaccination period as a bifurcation parameter, a sufficient condition under which the system has a positive periodic solution is obtained by using the bifurcation theorem.关键词：nonlinear pulse vaccination;epidemic model;periodic solution;global asymptotically stability;bifurcation
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发布时间：2023-12-11 - 摘要：The scalefree nature of a scalefree network yields uneven distribution of connections (degrees) between its nodes. As the topological structures of scalefree networks are not exactly figured up to now, people can not observe clearly paths of information dissemination in scalefree networks. Based on the idea of using spanning trees in researching topological structures of scale-free networks, the universal structure of scalefree networks without relating time and subnodes are tried to find, and balanced sets that are extensively related with spanning trees in the networks are researched, and furthermore show an algorithm for finding spanning trees with more leaves.关键词：balanced set;connected graph;spanning tree;scale-free network
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发布时间：2023-12-11 - 摘要：A mathematical model describing the transmission dynamics of disease with nonlinear incidence rate and delay is constructed. The local stability of the disease-free equilibrium and epidemic equilibrium is established by analyzing the corresponding characteristic equation. Using suitable Lyapunov function and LaSalle's invariance principle, it is proved that if R0<= 1 then the diseasefree equilibrium is globally asymptotically stable, but if R0＞1 then the epidemic equilibrium is globally asymptotically stable. Some numerical simulations are also given to explain the conclusions.关键词：epidemic disease;mathematical model;incubation period;latent relapse;delay;global stability
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发布时间：2023-12-11 - 摘要：According to the long rainy season and strong solar radiation in subtropical monsoon climate zone in western Guangdong, a set of high slope stability remote real-time monitoring system was designed and developed, which includes mechanical sensors, data acquisition and processor, wireless transmission devices, solar power system and information management platform. This system has been applied to the engineering stability monitoring of a slope in YunLuo Highway more than one year，and is still working well. This indicates that the solar power system is doing well in long-time energy supply. The analysis of the monitoring data is associated with the rainfall and the proceeding of the project. The results show that this system is sensitive to the rainfall and disturbance，and the slope is stable. The successful application of this system indicates that it can dill with the stability monitoring problems of the slope which are caused by the long rainy season and strong solar radiation in subtropical monsoon climate zone, and also shows that the system has very wide popularization and application prospects.关键词：high slope;stability;monitoring;remote
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发布时间：2023-12-11 - 摘要：The thermal decomposition of sucralose was measured using TG-DSC-FTIR hyphenated techniques under air flow and nitrogen flow. The result shows that the thermal process contains four stages. The first stage is endothermic, and the others are exothermic. The fourth stage has different reaction mechanism between under air flow and under nitrogen flow. FTIR analysis indicates that degradation of sucrolose cooked at high temperature does not produce poisonous material.关键词：sucralose;thermal decomposition;TG-DSC;TG-IR
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发布时间：2023-12-11 - 摘要：A hybrid ant colony algorithm was proposed.Because, ant colony algorithm used to solve the vehicle routing problem with time windows (VRPTW) is easy to fall into local optimum, and the quality of initial population in genetic algorithm affects the effectiveness of the algorithm directly. Firstly, the algorithm introduces the factors of time windows into node selection probability formula of ant colony algorithm to get the initial population. Secondly， the crossover and the mutation were operated to get a better path for the initial population. Applying Matlab environment for hybrid algorithm simulation, the effects on the vehicle utilization and path planning is obvious. It shows the algorithm is efficient, and can avoid falling into local optimum.关键词：ant colony algorithm;genetic algorithm;vehicle routing problem;time window
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发布时间：2023-12-11 - 摘要：Concentrated solar panel can effectively save semiconductor consumption of solar cells because of its high photoelectric conversion efficiency. However, traditional concentrated optical design is inflexible so that the overall dimensions of such panels are very large, coming with high installation and maintenance cost. Flat plate concentrated solar module using proportionate light compression, with small thickness, is flexible to design and fabricate according to sunshine condition. An optical design principle of flat plate solar module is proposed, and software simulation will show the optical performance of the concentrators.关键词：concentrated photovoltaic;non-image optics;high-concentrated solar system;low-concentrated solar system;reflective concentrated solar systems
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发布时间：2023-12-11 - 摘要：By exploiting an ancillary measured qubite and a system unitary evolution, a simpler method for state discrimination of qubits with a fixed inconclusive answer is given. The strategy includes the minimal error discrimination is zero as the probability of an inconclusive answer and the optimal unambiguous discrimination is some value as the probability of an inconclusive answer.The analytical solution was derived between the maximal total correct probability and the fixed inconclusive probability. By using an ancillary measured qubite, a unitary transformation acts on the whole initial system and the orthogonal measures on the output states can reach quantum state discrimination of two nonorthogonal states. The scheme itself provides an implementation of a positive operatorvalued measure of two nonorthogonal quantum states.关键词：quantum state discrimination;minimumerror discrimination;unambiguous discrimination
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发布时间：2023-12-11 - 摘要：The primary short circuited melted mark identification must be scientific and objective for physical evidence of the electricity fire during detecting, and the conclusions are related to the fire survey process. Currently, identification method of electricity fire, including macroscopic method and metallographic method, is very general and lacking of standard reference map and detailed description, The character of first short circuited melted mark is short of summary as well as analysis in actual fire cases. The macroscopic and metallographic character of melted mark from three class typical actual fire cases caused by first short circuited are analyzed. These cases include house, warehouse and workshop. Compared with character of melted mark from national standard, the simulated experiment is discussed. The relationship is summarized between the first short circuited melted mark and the surroundings. At the last, it is proposed that the attention points of using the first short circuited can provide for judgment and reference criterion of it.关键词：primary short circuited;melted mark;electricity fire;material evidence identification
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发布时间：2023-12-11 - 摘要：The soft soil contain high water content, high compressibility, high creep, low permeability and low strength. Recently, some researches have dealt with soft foundation using vacuum preloading-electroosmosis method which can only discharge partial weakly bound water in soft soil, but the amount of postconstruction settlement is still too much to meet the requirements of engineering. To solve this problem, a small amount of salt solution was added on the basis of vacuum preloading-electroosmosis method, known as vacuum preloading-electrokinetics method, and achieved a better experiment result. The soft soil in the pearl river delta region was studied. The comparative test was used between vacuum preloading-electroosmosis method and vacuum preloadingelectrokinetics method（adding Cacl2solution） in soft ground treatment, and it came to a conclusion that vacuum preloadingelectrokinetics method is at an advantage when dealing with soft soil, which provided a scientific basis for applications of vacuum preloadingelectrokinetics method.关键词：soft soil;vacuum preloading;electrokinetics
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发布时间：2023-12-11 - 摘要：The volatile oil was extracted from 3 samples Agaricus bisporus of Tibet using a steam distillation method, compared with 1 sample of Guangzhou. Forty volatile compounds were identified with GC-MS analysis and the NIST spectral library search. Through an area normalization method by adding menthol as reference material, the relative contents of No.2796,No.709,No.694 from Tibet were determined to be 43.10%，37.15%，31.34% respectively with the high content volatile compounds benzyl alcohol, furancarboxaldehyde, benzaldehyde, Cedrol. While No.0107 from Guangzhou was 27.24% with compounds benzyl alcohol, furancarboxaldehyde, benzaldehyde, 2-(1,1-dimethylethyl)-3-methyl-Oxirane, 5,6-dihydro-6-pentyl-2H-Pyran-2-one and 2-Propen-1-ol. The results showed that fungus source, origin of climate, cultivation methods affected the flavor of Agaricus bisporus and provided theoretical basis for the multiple development and utilization of Agaricus bisporus.关键词：Agaricus bisporus;volatile component;steam distillation;GC-MS
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发布时间：2023-12-11 - 摘要：As one class of the most important aggregation-induced emission materials, tetraphenylethylene derivatives have been widely used in organic light-emitting diodes and sensors with excellent photophysical and sensing properties. Tetraphenylethylene and 4-hexyloxybenzoic acid were combined together to synthesize a new compound with aggregation-induced emission (AIE) effect and self-assembly properties. In this work, the thermal, photophysical and selfassembly properties were mainly characterized by UV-vis absorption spectroscopy, fluorescence spectroscopy, thermal gravimetric analysis, differential scanning calorimetry, polarizing optical microscopy (POM), and scanning electron microscopy. The results showed that the compound emitted strong fluorescence, possessed high thermal stability, exhibited thermotropic liquid crystalline phase and formed different selfassembly structures.
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发布时间：2023-12-11 - 摘要：BiFeO3(BFO) thin films were prepared on ITO glass substrates using a chemical solution deposition method. The thin films exhibited pure perovskite structure, no secondary phase was observed. Meanwhile, they were smooth, dense and crack-free with small grain size of about 45 nm. Good electrical properties were observed in the films annealed at 550 ℃ for 1 h. The relative permittivity and the dissipation factor (at 1 kHz) were 198 and 3%, respectively. Driven by a electric field of 760 kV/cm, BFO showed 2Prof 25 μC/cm2and 2Ecof 650 kV/cm. The optical band gap of BFO thin films was 2.7 eV. These results indicated that the BFO thin films annealed at 550 ℃ had excellent properties and they had potentials in opticoelectric devices.关键词：chemical solution deposition method;BFO;relative permittivity;dielectric loss;optical band gap
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发布时间：2023-12-11 - 摘要：Acanthaster planci, commonly known as the crown of thorns starfish, usually preys upon scleractinian corals. Recently, Acanthaster planci has been found biocenotic association with diverse and abundant microbial communities. Using three different media, nearly 200 strains of the endophytic fungi were isolated from the Acantaster planci collected from the Sanya, Hainan province, China. The ITS-rDNA gene of 16 strains were sequenced, and submitted to GenBank. The register numbers of the sequences for these strains are KF999808KF999822 and KJ723458. The phylogenetic tree was then constructed by using a neighborjoining method, as well as the population diversity analysis. 16 strains belonging to 2 phyla (Deuteromycota, Ascomycota), 5 orders (Hypocreales, Eurotiales, Meliolales, Microascales), 6 genera (Trichoderma, Pseudallescheria, Penicillium, Neosartorya, Leptosphaerulina, Pleosporale, Fusarium,) were classified into 8 groups. And ten strains belonging to Fusarium indicates that Fusarium is the dominant fungi, and the endophytic fungi community with form of commensalism of Acanthaster planci has the low degree of homogeneity.关键词：Acanthaster planci;endophytic fungus;ITS-rDNA;diversity
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发布时间：2023-12-11 - 摘要：Green roofs, an increasingly visible component of urban environments, are becoming increasingly popular in many countries and have attracted much attention in China. The interest for green roofs has been related to their benefit as the crucial determinants of energy flux and of buildings water retention, so as to reduce stormwater runoff volumes and peak flows, mitigate effect of urban heat island and also provide urban habitats to improve urban biodiversity. However, there is rare research focusing on its carbon sequestration potential and the mitigation of climate change. In present study, two experiments were conducted on 10 green roofs with the objective of evaluating carbon accumulation potential of green roofs and the factors that affect green roof carbon storage. In the chamber experiment, a green roof was able to absorb CO2as high as 0.46 g per m2in one hour, and CO2concentration declined as much as 162×10-6over 5 minutes. Mean decrease of CO2concentration and CO2exchange rate in the chamber over the measurement period were 77.8×10-6and-0.24 g·m-2·h-1, respectively. However, there was a high degree of variability because the photosynthesis rate of green roof plant greatly is dependent on light intensity and temperature, which change from time to time. Decrease of CO2concentrations ranged from 23.50×10-6to 162.00×10-6and CO2exchange rates ranged from-0.06 to-0.46 g·m-2·h-1in the chamber. In the aboveground harvest experiment, data of the carbon reserve investigations showed that these green roofs stored an average of 92.55 g·m-2in aboveground biomass with also a wide variability(from 39.47 to 138.41 g·m-2), depended on the harvested biomass and carbon content of the biomass collected from the studied green roofs. In addition, it is notable that a significant correlation (R2=0.93) was observed between plant carbon content and substrate depth, while the correlations between substrate nutrient variables and carbon content was not statistically significant. Overall, the experimental results suggested that green roof can reduce the CO2concentration in surrounding environment by absorbing CO2in the daytime and act as a small carbon sink in urban area. It is likely that substrate depth may have big impacts on green roof carbon sequestration potential. Additional sophisticated research should be needed to evaluate the factors that contribute to the carbon sequestration potential of green roofs.关键词：green roofs;carbon sequestration;canopy CO2flus
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发布时间：2023-12-11 - 摘要：This paper presents two new species, Parasipyloidea jinggangshanensis Ho, sp. nov. and Macellina qizhouense Ho, sp. nov., from the Phasmida of China. The type specimens of the new species are deposited in the Museum of Biology, Sun YatSen University, Guangzhou.关键词：Phasmida;Parasipyloidea;Macellina;China;New species
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发布时间：2023-12-11 - 摘要：The methylationsensitive amplification polymorphism (MSAP) technique is an amplified fragment length polymorphism (AFLP) based method for detection of DNA methylation. It represents a reliable technique for the detection of cytosine methylation alterations at the site of CCGG in a genomewide perspective. MSAP has been extensively applied in plants and some animals, but no application in insects has been reported yet. The method was improved from DNA extraction, the amount of genomic DNA used for restriction enzyme digestion, time for enzyme digestions and ligation of adapters, and electrophoresis imaging method. And the method was applied successfully in Sogatella furcifera (Horvath), an important rice pest in China. It will provide some references and guiding values for the study of genome DNA methylation in other insects by using this method in the future. By comparing MSAP maps between male and female or between long wing and short wing of S. furcifera, it was found that there were obvious differences in DNA methylation patterns. This indicates that DNA methylation may be involved in gender and wings type differentiation.关键词：MSAP;DNA methylation;Sogatella furcifera;gender differentiation;wing dimorphism
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发布时间：2023-12-11 - 摘要：Genetic diversity of three wild populations of 〖WTBX〗Siniperca kneri〖WTBZ〗 from Youjiang River，Zuojiang River and Red Water River was studied by microsatellite DNA molecular markers. Total 19 pairs of highly polymorphic microsatellite primers of S. kneri, including 4 pairs exploited autonomously by bioinformatics and 15 pairs screened from 28 pairs of general primers, were adopted for this study. Analyzing 19 microsatellite locis for three populations, and total 102 individuals, Fixation Index among 3 populations varied from 0.001 4 to 1.000 0 showed the loss of heterozygosity, which leaded to lowering its response to the environment. Observed Number of Alleles (Na=19.473 7) , Shannons Information Index (I=2.399 8), Average Heterozygosity (Ave_Het =0720 6), and Polymorphism Information Content (0.447＜PIC＜0.947) were indicated the abundant genetic diversity among the three populations under Hardy-Weinberg equilibrium. But there was some differentiation among the three populations: Average Heterozygosity of Red Water River was the highest（Ave_Het=0.771 5）, and that of Zuojiang River and Youjiang River were lower and similar (0.692 1、0.698 3). The Genetic Differentiation Index (Fst) among 3 populations was 0.153 9, between 0.15 and 0.25, 84.61% of which was contributed by intra-population and 15.39% by inter-population. Fis Value was 0.576 1. Gene Flow (Nm) of all locis were widely varied between 0.147 4 and 8.909 1, and its average was 0.795 7, which indicated there was the medium genetic differentiation level among populations, and gene flow was smooth in general. Their inbreeding coefficient was relatively high which changed easily genetic structure of population. The UPGMA dendrogram based on the Nei's genetic distance suggested that the populations of Zuojiang River and Youjiang River clustered firstly and then did with that of Red Water River. The dendrogram relationship and genetic distance of three populations are closely linked with geography distribution.关键词：Siniperca kneri;Pearl River;genetic diversity;microsatellite
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发布时间：2023-12-11 - 摘要：Streamflow drought index (SDI) with 6-month was calculated using monthly runoffs as hydrologic drought analysis indicator at three hydrologic stations of Shuikou, Sikou and Chaoan during 1956-2011. And extraction of two variable element which is duration and degree of drought through run theory as well as analysis the drought characteristics of Hanjiang based on two variable joint probability distribution's method. The distribution of P-III was selected as the drought duration marginal distribution and the distribution of Weibull was selected as the drought degree marginal distribution by comparing each distribution fitting index. In order to obtain the design value of \ joint return period and co-occurrence with duration and degree of drought using joint distribution structured by GH Copula. For the sake of obtain conditional probability of drought duration or drought degree under the each one, to consider combination of different duration and degree of drought. Seen from the results, the greater risk of facing drought by Meijiang is more than the Hanjiang downstream.关键词：hydrologic drought;joint distribution;Copula function;the Hanjiang river
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发布时间：2023-12-11 - 摘要：WRF/UCM model was used to simulate the meteorological characteristics of an air pollution episode over the Pearl River Delta (PRD) in autumn, 2008. In order to study the impact of urbanization on atmospheric boundary layer characteristics, this article set up sensitivity experiments by changing the surface landuse type and the anthropogenic heat flux. The results showed that urbanization, including the increase of urban area, anthropogenic heat and the increase of its flux, helped to strengthen the effect of urban heat island and urban dry island, and the surface temperature inversion turned to be more obvious, which resulted in the accumulation of surface pollutants. Urbanization not only decreased the wind speed due to the increase of surface roughness, but also strengthened the heat island circulation, which was adverse to the diffusion of pollutants and caused the pollution episodes in urban areas. Moreover, the urbanization could raise the atmospheric boundary layer height both in daytime and nighttime.关键词：urbanization;land use type;anthropogenic heat;atmospheric boundary layer
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发布时间：2023-12-11 - 摘要：Based on the hot and humid climate and the underlying surface of Guangzhou, taking a typical community in Guangzhou Higher Education Mega Center as the test site, we analyze the microclimate characteristics over this area by meteorological observational data and a numerical model ENVI-met under typical sunny weather condition. The results indicate that the ENVI-met model can successfully simulate the special distribution and temporal evolution of temperature, humidity and flow field. ① There exist high temperature and low humidity, low temperature and high humidity over the different surfaces. ② Channeling effect can be found between the Adjoining Buildings, and the wind speed will become 1.4 to 1.7 times of the upper stream. ③ The corner flow can take place on two sides of the Single Building, and wind gust may be two to three times of the average wind speed. ④ There exists vortex between the Street Canyon Buildings. This effect is connected with the aspect ratio and the approach flow. This study helps us better understand some microclimate phenomenon in the area under sunny weather condition, which may play an important role in pedestrian comfort and diffusion of air pollutants, and can represent the features of hot and humid area. The research has practical significance for the city planning in the region with similar microclimate characteristics.关键词：microclimate;ENVI-met;numerical simulation;Guangzhou
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发布时间：2023-12-11 - 摘要：Time-dependent capacity increase of jacked piles is caused by the timeliness of shaft resistance and is affected directly by the character and mobilization of shaft resistance at the end of pile installation. However, the previous researches on the time-dependent capacity always relies on the correlation study between the pile installation resistance and its bearing capacity tested by load test, while the influence of the total shaft resistance at the end of pile installation on timeliness has been seldom considered . In this paper, jacking installation tests of model piles and load tests after installation are conducted to study the influence of base resistance on shaft resistance and further influence on the timeliness of bearing capacity of jacked pile with the theory of tribology in the Pearl River Delta. The study reveals that the friction at the pile-soil interface changes between lubricated friction and unlubricated friction during the whole pile installation. This phenomenon is caused by the change of installation velocity of the jacked pile when inserting different soil layers. If the pile shaft friction is unlubricated friction, then there is almost no timedependent capacity increase, if the pile shaft friction is lubricated friction, then the timeliness of bearing capacity is very significant. That means the shaft friction condition of pile can be used to prediction the timeliness of bearing capacity.关键词：end bearing jacked pile;shaft resistance of pile;timeliness of bearing capacity;unlubrication friction;lubrication friction
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发布时间：2023-12-11 - 摘要：The Duocaima Pb-Zn deposit is located in the northern Sanjiang polymetallic metallogenic belt. The values of δ34S in main sulfides are significantly variable, mainly ranging in between-26.72 ‰ and-4.1 ‰ with a normal distribution. The maximum δ34S value of galena is larger than the corresponding value of pyrite, indicating that the sulfur isotopes are in disequilibrium during the process of mineralization and that sulfur is originated mainly from bacterial sulfate reduction. The208Pb/204Pb values vary from 38.985 to 39.253, and206Pb/204Pb from 18.825 to 18.918 Tectonic evolution and Δβ~Δγ genetic classification diagrams of lead isotope show that the source of lead is complex and diverse. It is not only originated from the upper crust and orogenic belts, but also from the subducted zone with crust and mantle mixed. The values of δ13CV-PDB=1.2‰~6.7‰ and δ18OV-SMOW=16.4‰~23.4‰ show that the C and O are derived from marine carbonates, accompanied by carbonate dissolution. The origin of the Duocaima PbZn deposit is complex, The hosting carbonates and the mantle may provide metals, while biomineralization may play an important role in the oreforming process.关键词：isotopic geochemistry;metals origins;Duocaima Pb-Zn deposit;Northern Sanjiang metallogenic belt
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发布时间：2023-12-11
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