Promoting the development of deep-sea mineral exploration instrumentation can help alleviate the global resource shortage faced by mankind.X-ray fluorescence(XRF)spectrometry has been widely used in the in situ analys...
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Promoting the development of deep-sea mineral exploration instrumentation can help alleviate the global resource shortage faced by mankind.X-ray fluorescence(XRF)spectrometry has been widely used in the in situ analysis of deep-sea minerals owing to its fast analytical speed,nondestructive nature,and wide analytical *** study focused on the structural safety and detection efficiency of X-ray fluorescence in situ measurement equipment under high pressure for deep-sea XRF *** study first combined finite element analysis and experiments to design and optimize the structure of an X-ray probe tube required for deep-sea mineral exploration and to determine the Be window thickness to ensure stress ***,the Monte Carlo method was used to analyze and optimize the Be window thickness on the X-ray probe tube to improve the accuracy of the elemental ***,the effect of seawater thickness between the transmitter outer tube and rock wall was also *** results show that based on ocean depth in different detection environments,Be windows with a thickness of 1.5 mm or 2.0 mm can be selected to improve the detection efficiency of the device while ensuring the structural safety of the *** to the design features and detection requirements of the device,in deep-sea exploration of minerals with characteristic peak energies below 10 keV,the transmitter outer tube should be as close as possible to the rock wall inside the *** the characteristic peak energy of the minerals is more than 10 keV,the distance between the transmitter outer tube and rock wall inside the logging should be controlled to approximately 2 *** study provides feasible solutions for future deep-sea mineral resource development and a useful reference for elemental analysis of minerals in the deep-sea or other extreme working environments.
To detect radioactive substances with low activity levels,an anticoincidence detector and a high-purity germanium(HPGe)detector are typically used simultaneously to suppress Compton scattering background,thereby resul...
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To detect radioactive substances with low activity levels,an anticoincidence detector and a high-purity germanium(HPGe)detector are typically used simultaneously to suppress Compton scattering background,thereby resulting in an extremely low detection limit and improving the measurement ***,the complex and expensive hardware required does not facilitate the application or promotion of this ***,a method is proposed in this study to discriminate the digital waveform of pulse signals output using an HPGe detector,whereby Compton scattering background is suppressed and a low minimum detectable activity(MDA)is achieved without using an expensive and complex anticoincidence detector and *** electric-field-strength and energy-deposition distributions of the detector are simulated to determine the relationship between pulse shape and energy-deposition location,as well as the characteristics of energy-deposition distributions for fulland partial-energy deposition *** relationship is used to develop a pulse-shape-discrimination algorithm based on an artificial neural network for pulse-feature *** accurately determine the relationship between the deposited energy of gamma(γ)rays in the detector and the deposition location,we extract four shape parameters from the pulse signals output by the *** learning is used to input the four shape parameters into the ***,the pulse signals are identified and classified to discriminate between partial-and full-energy deposition *** partial-energy deposition events are removed to suppress Compton *** proposed method effectively decreases the MDA of an HPGeγ-energy dispersive *** results show that the Compton suppression factors for energy spectra obtained from measurements on ^(152)Eu,^(137)Cs,and ^(60)Co radioactive sources are 1.13(344 keV),1.11(662 keV),and 1.08(1332 keV),respectively,and that the corresponding MDAs are 1.4%,5.
Onlineγ-spectrometry systems for inland waters,most of which extract samples in situ and in real time,are able to produce reliable activity concentration measurements for waterborne radionuclides only when they are d...
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Onlineγ-spectrometry systems for inland waters,most of which extract samples in situ and in real time,are able to produce reliable activity concentration measurements for waterborne radionuclides only when they are distributed relatively uniformly and enter into a steady-state diffusion regime in the measurement *** protect residents’health and ensure the safety of the living environment,better timeliness is required for this measurement *** address this issue,this study established a mathematical model of the online waterγ-spectrometry system so that rapid warning and activity estimates can be obtained for water under non-steady-state(NSS)*** addition,the detection efficiency of the detector for radionuclides during the NSS diffusion process was determined by applying the computational fluid dynamics technique in conjunction with Monte Carlo *** this basis,a method was developed that allowed the online waterγ-spectrometry system to provide rapid warning and activity concentration estimates for radionuclides in *** analysis of the NSS-mode measurements of^(40)K radioactive solutions with different activity concentrations determined the optimum warning threshold and measurement time for producing accurate activity concentration estimates for *** experimental results show that the proposed NSS measurement method is able to give warning and yield accurate activity concentration estimates for radionuclides 55.42 and 69.42 min after the entry of a 10 Bq/L^(40)K radioactive solution into the measurement chamber,*** times are much shorter than the 90 min required by the conventional measurement ***,the NSS measurement method allows the measurement system to give rapid(within approximately 15 min)warning when the activity concentrations of some radionuclides reach their respective limits stipulated in the Guidelines for Drinking-water Quality of the WHO,suggesting that this method con
To accurately reconstruct the tomographic gamma scanning(TGS)transmission measurement image,this study optimized the transmission reconstruction equation based on the actual situation of TGS transmission *** the trans...
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To accurately reconstruct the tomographic gamma scanning(TGS)transmission measurement image,this study optimized the transmission reconstruction equation based on the actual situation of TGS transmission *** the transmission reconstruction equation and the Monte Carlo program Geant4,an innovative virtual trajectory length model was *** model integrated the solving process for the trajectory length and detection efficiency within the same *** mitigate the influence of the angular distribution ofγ-rays emitted by the transmitted source at the detector,the transport processes of numerous particles traversing a virtual nuclear waste barrel with a density of zero were ***,a certain amount of information was captured at each step of particle ***,the model addressed the nonuniform detection efficiency of the detector end face by considering whether the energy deposition of particles in the detector equaled their initial *** models were established to validate the accuracy and reliability of the virtual trajectory length *** 1 was a simplified nuclear waste barrel,whereas Model 2 closely resembled the actual structure of a nuclear waste *** results indicated that the proposed virtual trajectory length model significantly enhanced the precision of the trajectory length determination,substantially increasing the quality of the reconstructed *** example,the reconstructed images of Model 2 using the“point-to-point”and average trajectory models revealed a signalto-noise ratio increase of 375.0%and 112.7%,***,the virtual trajectory length model proposed in this study holds paramount significance for the precise reconstruction of transmission ***,it can provide support for the accurate detection of radioactive activity in nuclear waste barrels.
Fast neutron flux measurements with high count rates and high time resolution have important applications in equipment such as *** this study,real-time neutron and gamma discrimination was implemented on a self-develo...
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Fast neutron flux measurements with high count rates and high time resolution have important applications in equipment such as *** this study,real-time neutron and gamma discrimination was implemented on a self-developed 500-Msps,12-bit digitizer,and the neutron and gamma spectra were calculated directly on an FPGA.A fast neutron flux measurement system with BC-501A and EJ-309 liquid scintillator detectors was developed and a fast neutron measurement experiment was successfully performed on the HL-2 M tokamak at the Southwestern Institute of Physics,*** experimental results demonstrated that the system obtained the neutron and gamma spectra with a time accuracy of 1 *** count rates of up to 1 Mcps,the figure of merit was greater than 1.05 for energies between 50 keV and 2.8 MeV.
A dedicated weak current measurement system was designed to measure the weak currents generated by the neutron ionization *** system incorporates a second-order low-pass filter circuit and the Kalman filtering algorit...
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A dedicated weak current measurement system was designed to measure the weak currents generated by the neutron ionization *** system incorporates a second-order low-pass filter circuit and the Kalman filtering algorithm to effectively filter out noise and minimize interference in the measurement *** conducted under normal temperature conditions has demonstrated the system's high precision ***,it was observed that temperature variations can affect the measurement *** were collected across temperatures ranging from -20 to 70℃,and a temperature correction model was established through linear regression fitting to address this *** feasibility of the temperature correction model was confirmed at temperatures of -5 and 40℃,where relative errors remained below 0.1% after applying the temperature *** research indicates that the designed measurement system exhibits excellent temperature adaptability and high precision,making it particularly suitable for measuring weak currents.
With the rapid development of the nuclear power industry on a global scale,the discharge of radioactive e uents from nuclear power plants and their impact on the environment have become important issues in radioactive...
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With the rapid development of the nuclear power industry on a global scale,the discharge of radioactive e uents from nuclear power plants and their impact on the environment have become important issues in radioactive waste management,radiation protection,and environmental impact assessments.-detection of nuclides requires tedious processes,such as waiting for the radioactive balance of the sample and pretreatment separation,and there is an urgent need for a method specifically designed for mixing rapid energy spectrum measurement method for nuclide *** analysis of hybrid-energy spectrum is proposed in this study as a new algorithm,which takes advantage of the spectral analysis of-logarithmic energy spectrum and fitting ability of Fourier *** logarithmic energy spectrum is obtained by logarithmic conversion of the hybrid linear energy *** Fourier fitting interpolation method is used to fit the logarithmic energy spectrum ***,the interpolation points for the‘e ective high-energy window’and‘e ective low-energy window’corresponding to the highest E_(m)nuclide in the hybrid logarithmic fitted energy spectrum are set,and spline interpolation is performed three times to obtain the logarithmic fitted energy spectrum of the highest E_(m)***,the logarithmic fitted spectrum of the highest E_(m)nuclide is subtracted from the hybrid logarithmic fitted spectrum to obtain a logarithmic fitted spectrum comprised of the remaining lower E_(m)*** aforementioned process is iterated in a loop to resolve the logarithmic spectra of each nuclide in the original hybrid logarithmic ***,the radioactivity of E_(m)nuclides to be measured is *** the experimental tests,^(14)C,^(90)Sr,and ^(90)Y spectra,which are obtained using the Fourier fitting interpolation method are compared with the original simulated ^(14)C,^(90)Sr,and ^(90)Y spectra of *** measured liquid scintillator data of ^(90)Sr∕^(90)Y sample source
At present,industrial development is heavily dependent on traditional fossil energy,which has had an increasingly serious impact on the *** and renewable energy has received extensive attention and its proportion in d...
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At present,industrial development is heavily dependent on traditional fossil energy,which has had an increasingly serious impact on the *** and renewable energy has received extensive attention and its proportion in daily life has gradually *** a clean and renewable energy source that is not affected by changes in weather and seasons,geothermal energy has developed rapidly in recent years and has received increasing *** to reports,the total installed capacity of geothermal power generation in the world in 2020 was 15950 MW-an increase of~27%over *** the end of 2019,the total installed capacity for global geothermal direct use was 107727 MW-an increase of 52.0%compared with 2015;the total annual energy use was 1020887 TJ(283580 GWh)-an increase of 72.3%over *** the investigation of geothermal power generation technology in recent years,the characteristics and shortcomings of various power generation methods are *** the same time,this review analyzes the characteristics of geothermal energy and other renewable-energy(solar energy,water energy)coupling power generation,and analyzes the principles and characteristics of geothermal energy and various new-energy coupling power generation *** investigation and analysis,this review provides a complete understanding of various geothermal power generation technologies and provides insights into the future development direction.
With the construction and grid integration of large-scale photovoltaic power generation systems, utilizing energy storage technology to reduce grid-connected power fluctuations and enhance grid stability has become a ...
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In current neural network algorithms for nuclide identification in high-background,poor-resolution detectors,traditional network paradigms including back-propagation networks,convolutional neural networks,recurrent ne...
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In current neural network algorithms for nuclide identification in high-background,poor-resolution detectors,traditional network paradigms including back-propagation networks,convolutional neural networks,recurrent neural networks,etc.,have been limited in research on γ spectrum analysis because of their inherent mathematical *** is difficult to make progress in terms of training data requirements and prediction *** contrast to traditional network paradigms,network models based on the transformer structure have the characteristics of parallel computing,position encoding,and deep stacking,which have enabled good performance in natural language processing tasks in recent ***,in this paper,a transformer-based neural network (TBNN) model is proposed to achieve nuclide identification for the first ***,the Geant4 program was used to generate the basic single-nuclide energy spectrum through Monte Carlo simulations.A multi-nuclide energy spectrum database was established for neural network training using random matrices of γ-ray energy,activity,and *** on the encoder–decoder structure,a network topology based on the transformer was built,transforming the 1024-channel energy spectrum data into a 32×32 energy spectrum sequence as the model *** experiments and adjustments of model parameters,including the learning rate of the TBNN model,number of attention heads,and number of network stacking layers,the overall recognition rate reached 98.7%.Additionally,this database was used for training AI models such as back-propagation networks,convolutional neural networks,residual networks,and long shortterm memory neural networks,with overall recognition rates of 92.8%,95.3%,96.3%,and 96.6%,*** indicates that the TBNN model exhibited better nuclide identification among these AI models,providing an important reference and theoretical basis for the practical application of transformers in the qualitative and quantitativ
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