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Neutron activation analysis of ceramic tiles and its component and radon exhalation rate
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作者 A.El-Shershaby A.Sroor +2 位作者 F.Ahmed A.S.Abdel-Haleem Z.Abdel 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2004年第1期94-99,共6页
The concentrations of 20 trace elements in several ceramics tiles and ceramic composites used in Egypt were elementally analyzed by neutron activation analysis(NAA) technique. The samples and standard were irradiate... The concentrations of 20 trace elements in several ceramics tiles and ceramic composites used in Egypt were elementally analyzed by neutron activation analysis(NAA) technique. The samples and standard were irradiated with reactor for 4 h(in the Second Research Egyptian Reactor(Et-RR-2)) with thermal neutron flux 5.9×10 13 n/(cm 2·s).The gamma-ray spectra obtained were measured for several times by means of the hyper pure germanium detection system(HPGe). Also a solid state nuclear track detector(SSNTD) CR-39, was used to measure the emanation rate of radon for these samples. The radium concentrations were found to vary from 0.39—3.59 ppm and the emanation rates were found to vary from (0.728—5.688) × 10 -4 kg/(m 2· s).The elemental analysis of the ceramic tiles and ceramic composites have a great importance in assigning the physical properties and in turn the quality of the material. 展开更多
关键词 CERAMIC neutron activation analysis(NAA) radon emanation solid state nuclear track detector(SSNTD)
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The affect of industrial activities on zinc in alluvial Egyptian soil determined using neutron activation analysis
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作者 Abde.MF Abde.N 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2002年第3期330-332,共3页
Thirty two surface (0—20 cm) soil samples were collected from different locations in Egypt representing non polluted, moderately and highly polluted soils. The aim of this study was to evaluate total Zn content in ... Thirty two surface (0—20 cm) soil samples were collected from different locations in Egypt representing non polluted, moderately and highly polluted soils. The aim of this study was to evaluate total Zn content in alluvial soils of Nile Delta in Egypt by using the delayed neutron activation analysis technique (DNAA), in the irradiation facilities of the first Egyptian research reactor (ET RR 1). The gamma ray spectra were recorded with a hyper pure germanium detection system. The well resolved gamma ray peak at 1116.0 keV was efficiently used for 65 Zn content determination. Zn content in non polluted soil samples ranged between 74.1 and 103.8 ppm with an average of 98.5±5.1 ppm. Zn content in moderately polluted soils ranged between 136.0 and 232.5 ppm with an average of 180.1±32.6 ppm. The highest Zn levels ranging from 240.0 and 733.0 ppm with an average of 410.3±54.4 ppm, were observed in soil samples collected from, either highly polluted agricultural soils exposed to prolonged irrigation with industrial wastewater or surface soil samples from industrial sites. 展开更多
关键词 elemental analysis POLLUTION neutron activation analysis
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An application of a simple computer program for neutron activation analysis
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作者 N.Abdel Basset 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2001年第1期22-24,共3页
A simple computer program is designed for estimation of elemental concentration values in complex samples by neutron activation analysis technique. The program is applied for an Egyptian cement sample which irradiat... A simple computer program is designed for estimation of elemental concentration values in complex samples by neutron activation analysis technique. The program is applied for an Egyptian cement sample which irradiated at the Egyptian Research Reactor 1(ET RR 1). The data obtained is compared with the reported values. The time consumed for such calculations has a remarkable reduction in comparison with the routine work. 展开更多
关键词 neutron activation analysis cement sample EGYPT
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Elemental analysis of some Egyptian ores and industrial iron samples by neutron activation analysis
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作者 A.Srror N.Abdel Basset +1 位作者 A.S.Abdel Haleem A.M.Hassan 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2001年第1期115-118,共4页
Elemental analysis of iron ore samples and first industrial iron production prepared by the Egyptian Iron and Steel Company of Helwan near Cairo were determined by instrumental neutron activation analysis technique. ... Elemental analysis of iron ore samples and first industrial iron production prepared by the Egyptian Iron and Steel Company of Helwan near Cairo were determined by instrumental neutron activation analysis technique. Five samples from each kind were irradiated for a 48 hours at a thermal neutron flux of 4×10 12 n/(cm 2.s) in the first Egyptian research reactor ET RR 1. Also the Pneumatic irradiation Rabbit system (PIRS) attached to the reactor in Inshass, was used to measure the elements of short life time. The gamma ray spectra were recorded by means of the hyper pure germanium detection system. The concentration percentage values of major, minor and trace elements are presented. The long and short lived isotopes were considered. A comparative study and a discussion on the elemental concentration values are given. 展开更多
关键词 elemental analysis Egyptian iron samples neutron activation analysis
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Overview of Industrial Materials Detection Based on Prompt Gamma Neutron Activation Analysis Technology
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作者 Jiawen Fan Jie Xu Changming Wang 《World Journal of Engineering and Technology》 2020年第3期389-404,共16页
Prompt gamma neutron activation analysis (PGNAA) is a non-destructive online measurement nuclear analysis method. With its unique advantages, it has been widely used in online analysis of industrial materials such as ... Prompt gamma neutron activation analysis (PGNAA) is a non-destructive online measurement nuclear analysis method. With its unique advantages, it has been widely used in online analysis of industrial materials such as coal, cement, and minerals in recent years. </span><span style="font-family:Verdana;">However, there are many kinds of literature on PGNAA in the field of industrial materials detection, and there are still a few concluding articles. To this end,</span><span style="font-family:Verdana;"> based on the principle of PGNAA online analysis, the status quo and development of the real-time online detection of industrial material components in the field are reviewed and discussed by consulting a large number of domestic and foreign PGNAA related literature and data, to facilitate the reference of relevant scientific researchers. 展开更多
关键词 Prompt Gamma Neutron activation analysis Method PGNAA On-Line Detection of Industrial Materials
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Fluorine Assessment of Igneous Rocks by Neutron Activation Analysis
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作者 Abdelrazig Mohmed Abdelbagi 《World Journal of Nuclear Science and Technology》 2016年第3期140-146,共7页
The main goal of the current study was to determine the fluorine in the rock samples coal (SARM-18, SARM-19, and SARM-20), opal glass NBS91 and phosphate rock NBS694 using neutron activation analysis. Neutrons energy ... The main goal of the current study was to determine the fluorine in the rock samples coal (SARM-18, SARM-19, and SARM-20), opal glass NBS91 and phosphate rock NBS694 using neutron activation analysis. Neutrons energy of 14 MeV used for irradiation was produced by bombardment of a water-cooled titanium tri-tide target with a beam of deuterons accelerated to a potential of 350 KV to develop a neutron flux (10<sup>8</sup> n&sdot;cm<sup>-2</sup>&sdot;s<sup>-1</sup>) on the sample at the neutron generator in the ECN (Netherlands Energy Research Foundation) Petten. This new approach contributes to the existing knowledge of fluorine measurement by the coincidence channels investigation of the positron energy with respect to decay time for each radionuclide element. The present study was designed to determine the fluorine by fast neutron through the reaction of F<sup>19</sup> (n, 2n) F<sup>18</sup>. Interference was treated by irradiating the standard of these elements and reasonable selection of the decay time between the end of irradiation and beginning of counting time. The results of this method indicate that the concentration of fluorine is agreed fairly with literatures. 展开更多
关键词 FLUORINE New Method Rock Samples Neutron Generator activation analysis SPECTROSCOPY
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Determination of the Bromine, Manganese and Antimony in Nicotiana tabacum Solanaceae by Using the Neutron Activation Analysis Technique
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作者 Tufic Madi Filho Elson Barros Ferreira +1 位作者 José Roberto Berretta Maria da Conceição Costa Pereira 《Materials Sciences and Applications》 2022年第2期91-106,共16页
Tobacco addiction has been mentioned as a leading cause of preventable illnesses and premature disability. Smoking is the main cause of lung cancer and one of the factors that most contribute to the occurrence of hear... Tobacco addiction has been mentioned as a leading cause of preventable illnesses and premature disability. Smoking is the main cause of lung cancer and one of the factors that most contribute to the occurrence of heart diseases, among others. The herbaceous species Nicotiana tabacum is a plant of the solanaceae family used for tobacco production. Some authors have conducted research about heavy metals and the toxicity of tobacco. It is, frequently, found in low concentrations in the ground, and superficial and underground waters, even though they do not have environmental anthropogenic contributions. However, with the increase of industrial activities and mining together with the agrochemical use of contaminated organic and inorganic fertilizers, an alteration of the geochemical cycle occurs. As a consequence, the natural flow of these materials increases and is released into the biosphere, where they are often accumulated in the superior layer of the ground, accessible to the roots of the plants. During planting and plant development, fertilizers and insecticides, including organochlorines and organophosphates, are used;consequently, the smoke from cigarette smoking presents various toxic substances, such as bromine (Br), manganese (Mn) and antimony (Sb), elements studied in this work. The procedures for the preparation of the samples were carried out in our laboratories and submitted to irradiation with thermal neutrons at Nuclear and Energy Research Institute (IPEN/CNEN-SP), in the Atomic Energy Institute IEA-R1 research reactor. The irradiated material was, then, analyzed by gamma spectrometry, using a high purity germanium detector (HPGe). 展开更多
关键词 Nicotiana tabacum BROMINE MANGANESE ANTIMONY Neutron activation analysis
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Construction Activity Analysis of Workers Based on Human Posture Estimation Information
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作者 Xuhong Zhou Shuai Li +2 位作者 Jiepeng Liu Zhou Wu Yohchia Frank Chen 《Engineering》 SCIE EI CAS CSCD 2024年第2期225-236,共12页
Identifying workers’construction activities or behaviors can enable managers to better monitor labor efficiency and construction progress.However,current activity analysis methods for construction workers rely solely... Identifying workers’construction activities or behaviors can enable managers to better monitor labor efficiency and construction progress.However,current activity analysis methods for construction workers rely solely on manual observations and recordings,which consumes considerable time and has high labor costs.Researchers have focused on monitoring on-site construction activities of workers.However,when multiple workers are working together,current research cannot accu rately and automatically identify the construction activity.This research proposes a deep learning framework for the automated analysis of the construction activities of multiple workers.In this framework,multiple deep neural network models are designed and used to complete worker key point extraction,worker tracking,and worker construction activity analysis.The designed framework was tested at an actual construction site,and activity recognition for multiple workers was performed,indicating the feasibility of the framework for the automated monitoring of work efficiency. 展开更多
关键词 Pose estimation Activity analysis Object tracking Construction workers Automatic systems
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Accumulation of heavy metals in two crop seeds due to soil contamination as determined by neutron activation analysis techniques 被引量:2
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作者 M.F.Abdel Sabour Soil and Water Department, Nuclear Research Center, Cairo, Egypt A.S.Abdel Haleem Hot Lab’s Center, Atomic Energy Authority, Cairo, Egypt A.Sroor, N.Abdel Baset Nuclear Physics Lab, Girls Faculty, Ain Shams University, Egypt R.A.Zaghloul Mubarak City for Scientific Research and Technology, Egypt 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1998年第2期118-124,共7页
Samples of two crop seeds (corn and sesame) grown on different contaminated soil sources were collected and prepared for neutron activation analysis. Soil contamination sources were organic waste compost applied to s... Samples of two crop seeds (corn and sesame) grown on different contaminated soil sources were collected and prepared for neutron activation analysis. Soil contamination sources were organic waste compost applied to soil amendments namely, sewage sludge(Bs) and municipal solid waste (MSW) at 4%, 6% and 8% respectively. The non destructive NAA technique was used to determine some trace elements accumulation in plant seeds. Results revealed that increasing rate of tested organic waste resulted in dramatic increase in tested heavy metals levels in seeds(i.e., Fe, Zn, Co, Cr, Sc and Hg). Sesame seeds showed higher affinity to accumulate trace elements than corn grains in most tested elements. Moreover, MSW addition enhanced the accumulation of tested metals in seeds more than Bs compost. 展开更多
关键词 heavy metals crop seeds neutron activation analysis techniques.
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Application of neutron activation analysis in geochemistry and cosmochemistry 被引量:1
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作者 G.M. Kolesov(Vernadsky Institute of Geochem & Anal Chem.,Russian Academy of Sciences),Kosygin) st.19.117975、Moscow,V-334,Russian 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1994年第3期337-346,共10页
Generalized the use of neutron activation analysis(NAA)in the investigations of unique processes occurring in early stages of formations and evolution of bodies in solar system Out of them the formation of chondrules,... Generalized the use of neutron activation analysis(NAA)in the investigations of unique processes occurring in early stages of formations and evolution of bodies in solar system Out of them the formation of chondrules,emergence of ultra refractory inclusions in carbonaceous chondrites,formation of metallic and silicate phases of iron and stone meteorites,and formation of iron meteorites of different chemical groups Changes in regolite and lunar rock contents,differentiation in the upper mantle matter, identification of earthly meteoritic craters,transportation of cosmic(meteoritic)materials on to the Earth, investigations of unique events like Tunguska fall of the year 1908 and also ore formation studies and processes taking place on geochemical barrier type river-sea,ocean-atmosphere and so on Prospectives of NAA are pointed out 展开更多
关键词 neutron activation analysis GEOCHEMISTRY cosmochemistry Solar system
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Combined application of neutron activation analysis using IECF device and neural network for prediction of cement elements
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作者 G.H.Roshani E.Eftekhari-Zadeh +1 位作者 F.Shama A.Salehizadeh 《Radiation Detection Technology and Methods》 2017年第2期99-105,共7页
Purpose Gamma spectrum of a cement sample is not straightforward to analyze as a result of peak overlapping produced by Compton effect of gamma rays radiated from activated elements in the neutron activation process a... Purpose Gamma spectrum of a cement sample is not straightforward to analyze as a result of peak overlapping produced by Compton effect of gamma rays radiated from activated elements in the neutron activation process and also because of the change into the neutron energy spectrum in the target sample during activation.Methods Artificial neural network(ANN)is an excellent solution for complex and nonlinear systems.Consequently,the use of ANN for quantitative analysis of major cement elements including Ca,Si,Al,and Fe would be very advantageous.Iranian inertial electrostatic confinement fusion device is a fast,monoenergetic and steady neutron generator.It was simulated as a high-energy neutron source for performing neutron activation analysis.In the present study,a library of 29 members of delayed gamma-ray spectra of knowing cement samples were generated via MCNPX version 2.7.Specific photo-peaks related to Ca,Si,Al and Fe obtained from these spectra were used as inputs for ANN(21 of them for training and 8 for testing).Then,using MLP architecture,an ANN model has been presented to model the system to predict the percentages of the elements in cement.The ANN model is optimized to have only a hidden layer with five neurons.Results The comparison between modeling data and results of proposed MLP network shows that there is a good consistency between them.The MAE of training set for Ca,Si and Fe outputs were 0.0351,0.0656 and 0.0660,respectively,and the MAE of testing set for mentioned outputs were 0.0997,0.3046 and 0.8699,respectively.Conclusion Overall,it can be concluded that the defined dispensable errors show that this modeling is a good one as a prediction tool for the mentioned purpose. 展开更多
关键词 IR-IECF device Artificial neural network MCNPX Neutron activation analysis CEMENT
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Neutron activation method in the analysis of environmental objects
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作者 G.M. Kolesov(V.I.Vernadsky Institute of Geochem。&Anal.Chem.,Russian Academy of effciences,Kosygin St.19,Moskow,Russian) 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1995年第1期92-100,共9页
NeutronactivationmethodintheanalysisofenvironmentalobjectsG.M.Kolesov(V.I.VernadskyInstituteofGeochem。&Anal.... NeutronactivationmethodintheanalysisofenvironmentalobjectsG.M.Kolesov(V.I.VernadskyInstituteofGeochem。&Anal.Chem.,RussianAcad... 展开更多
关键词 neutron activation analysis:environmental objects nuclear-physical methods.
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Tracing Method of Natural Sediments by Neutron Activation and Its Application 被引量:3
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作者 Mao, Zhixiang Yan, Peilan +6 位作者 Huang, Jianwei Dai, Xiankai Han, Naibing Chai, Zhifang Qian, Qinfang Ma, Shulan Ma, Jianguo 《China Ocean Engineering》 SCIE EI 1991年第3期335-345,共11页
A new method of Neutron Activation Analysis (NAA) for sediment movement study is presented in this paper. Through analyzing the natural sediment, the information about natural tracing agents has been obtained, which c... A new method of Neutron Activation Analysis (NAA) for sediment movement study is presented in this paper. Through analyzing the natural sediment, the information about natural tracing agents has been obtained, which can show the direction of sediment movement and relative discharge of sediment transportation. Test results in some areas, such as Shanton Harbour and Hangzhou Bay, are in good agreement with those from normal hydrologic measurements and some results are not obtainable with the latter. The NAA is economical, practical and reliable, and should be widely used in engineering practice. 展开更多
关键词 HYDROLOGY MEASUREMENTS Neutrons activation analysis
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An evaluation of the influence of impurity concentration and composition in concrete on activation and radiation dose in the reactor facility
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作者 Jae Hyun KIM Myeong Hyeon WOO +1 位作者 Chang Ho SHIN Jong Kyung KIM 《辐射防护》 CAS CSCD 北大核心 2020年第6期486-490,共5页
The content analysis of radioactive waste and radiation dose evaluation is considered as one of the important factors in the reactor facility design.This kind of buildings consists of the concrete for the most part an... The content analysis of radioactive waste and radiation dose evaluation is considered as one of the important factors in the reactor facility design.This kind of buildings consists of the concrete for the most part and uses it as the structure and shield of the building.Generally,the concrete has impurities such as cobalt,europium,nickel,and cesium with specific content depending on the production method or manufacturing company.Dominant radioactive nuclides generated from the fundamental components of concrete are considered that it is less contributed to the radiation dose because they are beta decay nuclides in general.Thus,impurities of irradiated concrete in the reactor facilities,are considered occasionally an important evaluation factor for induced activity.In this study,the influence on the activation of impurities in concrete was evaluated from the radiation dose and induced activity calculations.The calculation was evaluated at the bio-shield which is one of the areas with the highest neutron irradiation among the concrete structure in the reactor facility.The results show that radioactive nuclides with gamma decay were produced in these impurities.Moreover,the radiation dose of concrete with impurities was higher than concrete without impurities.The increased radiation dose was quantified through the content of impurities. 展开更多
关键词 radiation dose CONCRETE IMPURITY activation analysis
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Atmospheric Deposition Study in the Area of Kardzhali Lead-Zinc Plant Based on Moss Analysis
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作者 Gergana Hristozova Savka Marinova +3 位作者 Lyudmila Pavlovna Strelkova Zoya Goryainova Marina Vladimirovna Frontasyeva Trajce Stafilov 《American Journal of Analytical Chemistry》 2014年第14期920-931,共12页
For the first time the moss biomonitoring technique was used to assess the environmental situation in the area affected by a lead zinc plant as one of the most hazardous enterprises in Bulgaria. 77 Hypnum cupressiform... For the first time the moss biomonitoring technique was used to assess the environmental situation in the area affected by a lead zinc plant as one of the most hazardous enterprises in Bulgaria. 77 Hypnum cupressiforme moss samples were collected in the Kardzhali municipality, in the summer and autumn of 2011. The concentrations of a total of 47 elements were determined by means of instrumental epithermal neutron activation analysis (ENAA), atomic absorption spectrometry (AAS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). Multivariate statistics was applied to characterize the sources of elements detected in the samples. Four groups of elements were found. In comparison to the data averaged for the area outside of the town, the atmospheric deposition loads for the elements of industrial origin in Kardzhali, where the smelter chimney is located, were found to be much higher. Median levels of the measured concentrations for the most toxic metals (Pb, Zn, Cd, As, Cu, In, Sb) were extremely high in this hot spot when compared to the median Bulgarian cross-country data from the 2010/2011 European moss survey. GIS technology was used to produce element distribution maps illustrating deposition patterns of element pollutants in the study area. The results obtained contribute to the Bulgarian environmental research used to study and control the manufacturing processes of a lead-zinc smelter in the town of Kardzhali. 展开更多
关键词 Moss Biomonitoring Heavy Metals Epithermal Neutron activation analysis Atomic Absorption Spectrometry
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Expression of Recombinant Human Lysozyme-tachyplesin I(hLYZ-TP I)in Pichia Pastoris and Analysis of Antibacterial Activity 被引量:7
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作者 GAO Yu ZHAO Hong Lei +5 位作者 FENG Xin ZHAI Rui Dong ZHU Seng DU Chong Tao SUN Chang Jiang LEI Lian Cheng 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2013年第4期319-322,共4页
Antimicrobial peptides (AMPs) are making headlines in science because they demonstrate superior microbicidal characteristics compared to synthetic and semi-synthetic antibiotics.
关键词 Design hLYZ-TP I)in Pichia Pastoris and analysis of Antibacterial Activity Expression of Recombinant Human Lysozyme-tachyplesin I TP
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Wavelet Analysis of Several Important Periodic Properties in the Relative Sunspot Numbers 被引量:16
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作者 Gui-MingLe Jia-LongWang 《Chinese Journal of Astronomy and Astrophysics》 CSCD 北大核心 2003年第5期391-394,共4页
We investigate the wavelet transform of yearly mean relative sunspot number series from 1700 to 2002. The curve of the global wavelet power spectrum peaks at 11-yr, 53-yr and 101-yr periods. The evolution of the ampli... We investigate the wavelet transform of yearly mean relative sunspot number series from 1700 to 2002. The curve of the global wavelet power spectrum peaks at 11-yr, 53-yr and 101-yr periods. The evolution of the amplitudes of the three periods is studied. The results show that around 1750 and 1800, the amplitude of the 53-yr period was much higher than that of the the 11-yr period, that the ca. 53-yr period was apparent only for the interval from 1725 to 1850, and was very low after 1850, that around 1750, 1800 and 1900, the amplitude of the 101-yr period was higher than that of the 11-yr period and that, from 1940 to 2000, the 11-yr period greatly dominates over the other two periods. 展开更多
关键词 Sun: sunspots - Sun: activity - methods: data analysis
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Phase analysis of sunspot group numbers on both solar hemispheres 被引量:2
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作者 Lin-Hua Deng Zhong-Quan Qu +1 位作者 Xiao-Li Yan Kai-Rang Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2013年第1期104-114,共11页
Cross-correlation analysis and wavelet transform methods are proposed to investigate the phase relationship between the monthly sunspot group numbers in the solar northern and southern hemispheres. It is found that (... Cross-correlation analysis and wavelet transform methods are proposed to investigate the phase relationship between the monthly sunspot group numbers in the solar northern and southern hemispheres. It is found that (1) the monthly sunspot group numbers in the northern hemisphere begin two months earlier than those in the southern one, which should lead to phase asynchrony between them but with a slight effect; (2) the Schwabe cycle length for the monthly sunspot group numbers in the two hemispheres obviously differs from each other, and the mean Schwabe cycle length of the monthly sunspot group numbers in the northern hemisphere is slightly larger than that in the southern one; (3) the monthly sunspot group numbers in the northern hemisphere precede those in the southern hemisphere during the years of about 1874- 1927, after which, the southern hemisphere leads the northern hemisphere in the years 1928-1964, and then the northern hemisphere leads in time till the present. 展开更多
关键词 methods data analysis -- Sun activity -- Sun sunspots
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Cloning and Functional Analysis of Xylem Specific Promoter Deletion Fragment
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作者 Yajing LUO Liang WANG +1 位作者 Kejiu DU Shuang ZHANG 《Agricultural Biotechnology》 CAS 2016年第6期1-3,9,共4页
Xylem-specific promoter could regulate efficient expression of foreign genes in xylem. Deletion analysis method was applied to obtain 5' deletion promoter fragments MU2 andMU4 with different distances from transcript... Xylem-specific promoter could regulate efficient expression of foreign genes in xylem. Deletion analysis method was applied to obtain 5' deletion promoter fragments MU2 andMU4 with different distances from transcription start site of xylem-specific promoter MDCcsAP through PCR procedure. Then CaMV35S promoter in plant expression vector pBI121 was replaced by amplified fragments. The recombinant plasmids fused with corresponding gene segments and GUS reporter gene were obtained and transformed into Agrobacterium. The results of the tobacco transient transformation test showed that MU2 andMU4 had the promoter function, and both of their activity were significantly higher than that of CaMV35S promoter, and they had the characteristics of xylem tissue specificity as well. Research on xy- lem-specific promoter structure and function could lay a foundation for the determination of necessary components to the xylem tissue specificity and cis-acting ele- ments with induction activity, so as to enable the regulation of efficient expression of exogenous genes in specific time and specific tissues in plants through these cis-acting elements. 展开更多
关键词 PROMOTER Deletion analysis Vector construction GUS activity analysis
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Characterizing large-scale weak interlayer shear zones using conditional random field theory 被引量:1
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作者 Gang Han Chuanqing Zhang +5 位作者 Hemant Kumar Singh Rongfei Liu Guan Chen Shuling Huang Hui Zhou Yuting Zhang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第10期2611-2625,共15页
The shear behavior of large-scale weak intercalation shear zones(WISZs)often governs the stability of foundations,rock slopes,and underground structures.However,due to their wide distribution,undulating morphology,com... The shear behavior of large-scale weak intercalation shear zones(WISZs)often governs the stability of foundations,rock slopes,and underground structures.However,due to their wide distribution,undulating morphology,complex fabrics,and varying degrees of contact states,characterizing the shear behavior of natural and complex large-scale WISZs precisely is challenging.This study proposes an analytical method to address this issue,based on geological fieldwork and relevant experimental results.The analytical method utilizes the random field theory and Kriging interpolation technique to simplify the spatial uncertainties of the structural and fabric features for WISZs into the spatial correlation and variability of their mechanical parameters.The Kriging conditional random field of the friction angle of WISZs is embedded in the discrete element software 3DEC,enabling activation analysis of WISZ C2 in the underground caverns of the Baihetan hydropower station.The results indicate that the activation scope of WISZ C2 induced by the excavation of underground caverns is approximately 0.5e1 times the main powerhouse span,showing local activation.Furthermore,the overall safety factor of WISZ C2 follows a normal distribution with an average value of 3.697. 展开更多
关键词 Interlayer shear weakness zone Baihetan hydropower station Conditional random field Kriging interpolation technique activation analysis
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