In the data transaction process within a data asset trading platform,quantifying the trustworthiness of data source nodes is challenging due to their numerous attributes and complex structures.To address this issue,a ...In the data transaction process within a data asset trading platform,quantifying the trustworthiness of data source nodes is challenging due to their numerous attributes and complex structures.To address this issue,a distributed data source trust assessment management framework,a trust quantification model,and a dynamic adjustment mechanism are proposed.Themodel integrates the Analytic Hierarchy Process(AHP)and Dempster-Shafer(D-S)evidence theory to determine attribute weights and calculate direct trust values,while the PageRank algorithm is employed to derive indirect trust values.Thedirect and indirect trust values are then combined to compute the comprehensive trust value of the data source.Furthermore,a dynamic adjustment mechanism is introduced to continuously update the comprehensive trust value based on historical assessment data.By leveraging the collaborative efforts of multiple nodes in the distributed network,the proposed framework enables a comprehensive,dynamic,and objective evaluation of data source trustworthiness.Extensive experimental analyses demonstrate that the trust quantification model effectively handles large-scale data source trust assessments,exhibiting both strong trust differentiation capability and high robustness.展开更多
Lead(Pb)plays a significant role in the nuclear industry and is extensively used in radiation shielding,radiation protection,neutron moderation,radiation measurements,and various other critical functions.Consequently,...Lead(Pb)plays a significant role in the nuclear industry and is extensively used in radiation shielding,radiation protection,neutron moderation,radiation measurements,and various other critical functions.Consequently,the measurement and evaluation of Pb nuclear data are highly regarded in nuclear scientific research,emphasizing its crucial role in the field.Using the time-of-flight(ToF)method,the neutron leakage spectra from three^(nat)Pb samples were measured at 60°and 120°based on the neutronics integral experimental facility at the China Institute of Atomic Energy(CIAE).The^(nat)Pb sample sizes were30 cm×30 cm×5 cm,30 cm×30 cm×10 cm,and 30 cm×30 cm×15 cm.Neutron sources were generated by the Cockcroft-Walton accelerator,producing approximately 14.5 MeV and 3.5 MeV neutrons through the T(d,n)^(4)He and D(d,n)^(3)He reactions,respectively.Leakage neutron spectra were also calculated by employing the Monte Carlo code of MCNP-4C,and the nuclear data of Pb isotopes from four libraries:CENDL-3.2,JEFF-3.3,JENDL-5,and ENDF/B-Ⅷ.0 were used individually.By comparing the simulation and experimental results,improvements and deficiencies in the evaluated nuclear data of the Pb isotopes were analyzed.Most of the calculated results were consistent with the experimental results;however,a few areas did not fit well.In the(n,el)energy range,the simulated results from CENDL-3.2 were significantly overestimated;in the(n,inl)D and the(n,inl)C energy regions,the results from CENDL-3.2 and ENDF/B-Ⅷ.0 were significantly overestimated at 120°,and the results from JENDL-5 and JEFF-3.3 are underestimated at 60°in the(n,inl)D energy region.The calculated spectra were analyzed by comparing them with the experimental spectra in terms of the neutron spectrum shape and C/E values.The results indicate that the theoretical simulations,using different data libraries,overestimated or underestimated the measured values in certain energy ranges.Secondary neutron energies and angular distributions in the data files have been presented to explain these discrepancies.展开更多
Beryllium(^(9)Be)serves as a crucial neutron multiplier and reflection material,being extensively employed in the nuclear industry.The evaluated nuclear data are utilized in the design of the nuclear devices.Following...Beryllium(^(9)Be)serves as a crucial neutron multiplier and reflection material,being extensively employed in the nuclear industry.The evaluated nuclear data are utilized in the design of the nuclear devices.Following the interaction between neutrons and^(9)Be,all neutrons generated stem from the^(9)Be(n,2n)^(8)Be reaction channel,except for the elastic scattering reaction channel.Nevertheless,the data of the outgoing neutron double differential cross section of the reaction channel provided by the latest internationally evaluated libraries still exhibit considerable discrepancies.A shielding integral experiment based on slab^(9)Be samples with measurements of neutron spectra leaked from different angles is an effective approach to verify the double differential cross-section data.Hence,in this study,a shielding integral experiment of^(9)Be samples of different thicknesses was conducted using a nanosecond pulsed deuterium-tritium neutron source established by the China Institute of Atomic Energy.The neutron time-of-flight spectra of three thicknesses(4.4 cm,8.8 cm,and 13.2 cm)and six angles(47°,58°,73°,107°,122°,and 133°)were measured by the neutron time-of-flight method,and 18 sets of experimental data were obtained.Additionally,the MCNP-4C program was used to obtain the simulated results of the leakage neutron spectra using the evaluated nuclear data of^(9)Be from the CENDL-3.2,ENDF/B-Ⅷ.0,JENDL-5,and JEFF-3.3 libraries.The simulated results of the leakage neutron spectra were compared with the experimental results,and the results showed that in the elastic scattering energy region,the simulated results from the CENDL-3.2,ENDF/B-Ⅷ.0,and JENDL-5 libraries were slightly higher at small angles and slightly lower at large angles.In the(n,2n)energy region,the simulated results from the CENDL-3.2 library were significantly different from the experimental results in terms of spectral shape,and the simulated results from the ENDF/B-Ⅷ.0 and the JENDL-5 libraries were in good agreement with the experimental results at small angles but low at large angles.The simulated results from the JEFF-3.3 library showed serious underestimation at all angles.展开更多
Hefei Light Source(HLS)is a synchrotron radiation light source that primarily produces vacuum ultraviolet and soft X-rays.It currently consists of ten experimental stations,including a soft X-ray microscopy station.As...Hefei Light Source(HLS)is a synchrotron radiation light source that primarily produces vacuum ultraviolet and soft X-rays.It currently consists of ten experimental stations,including a soft X-ray microscopy station.As part of its on-going efforts to establish a centralized scientific data management platform,HLS is in the process of developing a test sys-tem that covers the entire lifecycle of scientific data,including data generation,acquisition,processing,analysis,and de-struction.However,the instruments used in the soft X-ray microscopy experimental station rely on commercial propriet-ary software for data acquisition and processing.We developed a semi-automatic data acquisition program to facilitate the integration of soft X-ray microscopy stations into a centralized scientific data management platform.Additionally,we cre-ated an online data processing platform to assist users in analyzing their scientific data.The system we developed and de-ployed meets the design requirements,successfully integrating the soft X-ray microscopy station into the full lifecycle management of scientific data.展开更多
Automatic modulation recognition(AMR)of radiation source signals is a research focus in the field of cognitive radio.However,the AMR of radiation source signals at low SNRs still faces a great challenge.Therefore,the ...Automatic modulation recognition(AMR)of radiation source signals is a research focus in the field of cognitive radio.However,the AMR of radiation source signals at low SNRs still faces a great challenge.Therefore,the AMR method of radiation source signals based on two-dimensional data matrix and improved residual neural network is proposed in this paper.First,the time series of the radiation source signals are reconstructed into two-dimensional data matrix,which greatly simplifies the signal preprocessing process.Second,the depthwise convolution and large-size convolutional kernels based residual neural network(DLRNet)is proposed to improve the feature extraction capability of the AMR model.Finally,the model performs feature extraction and classification on the two-dimensional data matrix to obtain the recognition vector that represents the signal modulation type.Theoretical analysis and simulation results show that the AMR method based on two-dimensional data matrix and improved residual network can significantly improve the accuracy of the AMR method.The recognition accuracy of the proposed method maintains a high level greater than 90% even at -14 dB SNR.展开更多
Understanding the origins of potential source rocks and unraveling the intricate connections between reservoir oils and their source formations in the Siwa Basin(Western Desert,Egypt)necessitate a thorough oil-source ...Understanding the origins of potential source rocks and unraveling the intricate connections between reservoir oils and their source formations in the Siwa Basin(Western Desert,Egypt)necessitate a thorough oil-source correlation investigation.This objective is achieved through a meticulous analysis of well-log responses,Rock-Eval pyrolysis,and biomarker data.The analysis of Total Organic Carbon across 31 samples representing Paleozoic formations in the Siwa A-1X well reveals a spectrum of organic richness ranging from 0.17 wt%to 2.04 wt%,thereby highlighting diverse levels of organic content and the presence of both Type II and Type III kerogen.Examination of the fingerprint characteristics of eight samples from the well suggests that the Dhiffah Formation comprises a blend of terrestrial and marine organic matter.Notably,a significant contribution from more oxidized residual organic matter and gas-prone Type III kerogen is observed.Contrarily,the Desouky and Zeitoun formations exhibit mixed organic matter indicative of a transitional environment,and thus featuring a pronounced marine influence within a more reducing setting,which is associated with Type II kerogen.Through analysis of five oil samples from different wells—SIWA L-1X,SIWA R-3X,SIWA D-1X,PTAH 5X,and PTAH 6X,it is evident that terrestrial organic matter,augmented by considerable marine input,was deposited in an oxidizing environment,and contains Type III kerogen.Geochemical scrutiny confirms the coexistence of mixed terrestrial organic matter within varying redox environments.Noteworthy is the uniformity of identified kerogen Types II and III across all samples,known to have potential for hydrocarbon generation.The discovery presented in this paper unveils captivating prospects concerning the genesis of oil in the Jurassic Safa reservoir,suggesting potential links to Paleozoic sources or even originating from the Safa Member itself.These revelations mark a substantial advancement in understanding source rock dynamics and their intricate relationship with reservoir oils within the Siwa Basin.By illuminating the processes of hydrocarbon genesis in the region,this study significantly enriches our knowledge base.展开更多
Aeromagnetic data over the Mamfe Basin have been processed. A regional magnetic gridded dataset was obtained from the Total Magnetic Intensity (TMI) data grid using a 3 × 3 convolution (Hanning) filter to remove ...Aeromagnetic data over the Mamfe Basin have been processed. A regional magnetic gridded dataset was obtained from the Total Magnetic Intensity (TMI) data grid using a 3 × 3 convolution (Hanning) filter to remove regional trends. Major similarities in magnetic field orientation and intensities were observed at identical locations on both the regional and TMI data grids. From the regional and TMI gridded datasets, the residual dataset was generated which represents the very shallow geological features of the basin. Processing this residual data grid using the Source Parameter Imaging (SPI) for magnetic depth suggests that the estimated depths to magnetic sources in the basin range from about 271 m to 3552 m. The highest depths are located in two main locations somewhere around the central portion of the study area which correspond to the area with positive magnetic susceptibilities, as well as the areas extending outwards across the eastern boundary of the study area. Shallow magnetic depths are prominent towards the NW portion of the basin and also correspond to areas of negative magnetic susceptibilities. The basin generally exhibits a variation in depth of magnetic sources with high, average and shallow depths. The presence of intrusive igneous rocks was also observed in this basin. This characteristic is a pointer to the existence of geologic resources of interest for exploration in the basin.展开更多
The real-time monitoring of environmental radiation dose for nuclear fa-cilities is an important part of safety, in order to guarantee the accuracy of the monitoring results regular calibration is necessary. Around nu...The real-time monitoring of environmental radiation dose for nuclear fa-cilities is an important part of safety, in order to guarantee the accuracy of the monitoring results regular calibration is necessary. Around nuclear facilities there are so many environmental dosimeters installed dispers-edly, because of its huge quantity, widely distributed, and in real-time monitoring state;it will cost lots of manpower and finance if it were tak-en to calibrate on standard laboratory;what’s more it will make the en-vironment out of control. To solve the problem of the measurement ac-curacy of the stationary gamma radiation dosimeter, an on-site calibra-tion method is proposed. The radioactive source is X-ray spectrum, and the dose reference instrument which has been calibrated by the national standard laboratory is a high pressure ionization. On-site calibration is divided into two parts;firstly the energy response experiment of dosim-eter for high and low energy is done in the laboratory, and the energy response curve is obtained combining with Monte Carlo simulation;sec-ondly experiment is carried out in the field of the measuring dosimeter, and the substitution method to calibrate the dosimeter is used;finally the calibration coefficient is gotten through energy curve correction. In order to verify the accuracy of on-site calibration method, the calibrated dosimeter is test in the standard laboratory and the error is 3.4%. The re-sult shows that the on-site calibration method using X-ray is feasible, and it can improves the accuracy of the measurement results of the stationary γ-ray instrument;what’s more important is that it has great reference value for the radiation safety management and radiation environment evaluation.展开更多
As part of“The Earth Summit Mission-2022”during the second Tibetan Plateau Scientific Expedition and Research(STEP)in April and May 2022,we conducted the ozone sounding experiment(an ozonesonde mated to a radiosonde...As part of“The Earth Summit Mission-2022”during the second Tibetan Plateau Scientific Expedition and Research(STEP)in April and May 2022,we conducted the ozone sounding experiment(an ozonesonde mated to a radiosonde)at Mt.Qomolangma Base Camp(MQBC;86.85°E,28.14°N;5200 m),a location at an extremely high altitude.A total of ten sounding profiles were obtained between April 30 and May 06,2022,of which seven profiles were above35 km in altitude,with a maximum detection altitude up to 39.0 km.This study presents the temporal variation and vertical distributions of atmospheric temperature,humidity,and ozone during the MQBC campaign.The averaged ozone concentration was high(68.3 ppbv)at the surface and then increased smoothly until peaking(~110 ppbv)in the middle troposphere(approximately 10 km),and afterward,the ozone concentration increased rapidly from the upper troposphere to a maximum of~10 ppmv at~30 km.The enhanced ozone concentration in the middle troposphere was associated with the blocking high pressure,and transport from the southern flank of the Himalayas occurred during the campaign period.The average total ozone column was 291.9±21.4 DU for the seven profiles exceeding 35km in altitude.The ozonesonde measurements were also compared with the vertical ozone profiles retrieved from the space-borne ozone products from the Microwave Limb Sounder(MLS)onboard the Aura satellite and the Atmospheric Infrared Sounder(AIRS)onboard the Aqua satellite.展开更多
Water storage has important significance for understanding water cycles of global and local domains and for monitoring climate and environmental changes. As a key variable in hydrology, water storage change represents...Water storage has important significance for understanding water cycles of global and local domains and for monitoring climate and environmental changes. As a key variable in hydrology, water storage change represents the sum of precipitation, evaporation, surface runoff, soil water and groundwater exchanges. Water storage change data during the period of 2003-2008 for the source region of the Yellow River were collected from Gravity Recovery and Climate Experiment （GRACE） satellite data. The monthly actual evaporation was estimated according to the water balance equation. The simulated actual evaporation was significantly consistent and correlative with not only the observed pan （20 cm） data, but also the simulated results of the version 2 of Simple Biosphere model. The average annual evaporation of the Tangnaihai Basin was 506.4 mm, where evaporation in spring, summer, autumn and winter was 130.9 mm, 275.2 mm, 74.3 mm and 26.1 mm, and accounted for 25.8%, 54.3%, 14.7% and 5.2% of the average annual evaporation, respectively, The precipitation increased slightly and the actual evaporation showed an obvious decrease. The water storage change of the source region of the Yellow River displayed an increase of 0.51 mm per month from 2003 to 2008, which indicated that the storage capacity has significantly increased, probably caused by the degradation of permafrost and the increase of the thickness of active layers. The decline of actual evaporation and the increase of water storage capacity resulted in the increase of river runoff.展开更多
An earthquake of Ms= 6, 9 occurred at the Gonghe, Qinghai Province, China on April 26, 1990. Three larger aftershocks took place at the same region, Ms= 5. 0 on May 7, 1990, Ms= 6. 0 on Jan. 3, 1994 and Ms= 5. 7on Feb...An earthquake of Ms= 6, 9 occurred at the Gonghe, Qinghai Province, China on April 26, 1990. Three larger aftershocks took place at the same region, Ms= 5. 0 on May 7, 1990, Ms= 6. 0 on Jan. 3, 1994 and Ms= 5. 7on Feb. 16, 1994. The long-period recordings of the main shock from China Digital Seismograph Network (CDSN) are deconvolved for the source time functions by the correspondent0 recordings of the three aftershocks asempirical Green's functions (EGFs). No matter which aftershock is taken as EGF, the relative source time functions (RSTFs) Obtained are nearly identical. The RSTFs suggest the Ms= 6. 9 event consists of at least two subevents with approximately equal size whose occurrence times are about 30 s apart, the first one has a duration of 12 s and a rise time of about 5 s, and the second one has a duration of 17 s and a rise time of about & s. COmParing the RSTFs obtained from P- and SH-phases respectively, we notice that those from SH-phases are a slightly more complex than those from p-phases, implying other finer subevents exist during the process of the main shock. It is interesting that the results from the EGF deconvolution of long-Period way form data are in good agreement with the results from the moment tensor inversion and from the EGF deconvolution of broadband waveform data. Additionally, the two larger aftershocks are deconvolved for their RSTFs. The deconvolution results show that the processes of the Ms= 6. 0 event on Jan. 3, 1994 and the Ms= 5. 7 event on Feb. 16,1994 are quite simple, both RSTFs are single impulses.The RSTFs of the Ms= 6. 9 main shock obtained from different stations are noticed to be azimuthally dependent, whose shapes are a slightly different with different stations. However, the RSTFs of the two smaller aftershocks are not azimuthally dependent. The integrations of RSTFs over the processes are quite close to each other, i. e., the scalar seismic moments estimated from different stations are in good agreement. Finally the scalar seismic moments of the three aftershocks are compared. The relative scalar seismic moment Of the three aftershocks deduced from the relative scalar seismic moments of the Ms=6. 9 main shock are very close to those inverted directly from the EGF deconvolution. The relative scalar seismic moment of the Ms =6. 9 main shock calculated using the three aftershocks as EGF are 22 (the Ms= 6. 0 aftershock being EGF), 26 (the Ms= 5. 7 aftershock being EGF) and 66 (the Ms= 5. 5 aftershock being EGF), respectively. Deducingfrom those results, the relative scalar sesimic moments of the Ms= 6. 0 to the Ms= 5. 7 events, the Ms= 6. 0 tothe Ms= 5. 5 events and the Ms= 5. 7 to the Ms= 5. 5 events are 1. 18, 3. 00 and 2. 54, respectively. The correspondent relative scalar seismic moments calculated directly from the waveform recordings are 1. 15, 3. 43, and 3. 05.展开更多
As the key ion source component of nuclear fusion auxiliary heating devices, the radio frequency （RF） ion source is developed and applied gradually to offer a source plasma with the advantages of ease of control and...As the key ion source component of nuclear fusion auxiliary heating devices, the radio frequency （RF） ion source is developed and applied gradually to offer a source plasma with the advantages of ease of control and high reliability. In addition, it easily achieves long-pulse steady-state operation. During the process of the development and testing of the RF ion source, a lot of original experimental data will be generated. Therefore, it is necessary to develop a stable and reliable computer data acquisition and processing application system for realizing the functions of data acquisition, storage, access, and real-time monitoring. In this paper, the development of a data acquisition and processing application system for the RF ion source is presented. The hardware platform is based on the PXI system and the software is programmed on the LabVIEW development environment. The key technologies that are used for the implementation of this software programming mainly include the long-pulse data acquisition technology, multi- threading processing technology, transmission control communication protocol, and the Lempel-Ziv-Oberhumer data compression algorithm. Now, this design has been tested and applied on the RF ion source. The test results show that it can work reliably and steadily. With the help of this design, the stable plasma discharge data of the RF ion source are collected, stored, accessed, and monitored in real-time. It is shown that it has a very practical application significance for the RF experiments.展开更多
An earthquake of M S=6.9 occurred in Gonghe County, Qinghai Province, China on April 26, 1990.This earthquake was followed by three larger aftershocks of M S=5.5 on May 7, 1990, M S=6.0 on Jan.3, 199...An earthquake of M S=6.9 occurred in Gonghe County, Qinghai Province, China on April 26, 1990.This earthquake was followed by three larger aftershocks of M S=5.5 on May 7, 1990, M S=6.0 on Jan.3, 1994, and M S=5.7 on Feb.16, 1994, consecutively. The moment tensors of these earthquakes as function of time were obtained by the technique of moment tensor inversion in frequency domain . The results inverted indicate that these earthquakes had a very similar focal mechanism of predominantly reverse faulting on a plane striking NWW, dipping to SSW.The scalar seismic moments of these earthquakes are M 0=9.4×10 18 Nm for the M S=6.9 event, 8.0×10 16 Nm for the M S=5.5 event, 4.9×10 17 Nm for the M S =6.0 event and 2.9×10 17 Nm for the M S=5.7 event, respectively. The results inverted also show that the source processes of these events were significantly different. The main shock had a very complex process, consisting of two distinct sub events with comparable sizes. The first sub event occurred in the first 12s, having a seismic moment of 4.7×10 18 Nm, and the second one continued from 31s to 41s, having a seismic moment of 2.5×10 18 Nm. In addition, a much smaller sub event, having a seismic moment of about 2.1×10 18 Nm, may exist in the interval of 12 s and 31 s, In contrast, the source processes of the three aftershocks are quite simple. The source time function of each of aftershocks is a single impulse, suggestting that each of aftershocks consists of a mainly uninterrupted rupture. The rise times and total rupture durations are 4 s and 11 s for the M S=5.5 event, 6 s and 16 s for the M S= 6.0 event and 6 s and 13 s for the M S=5.7 event, respectively.展开更多
Source location is the core foundation of microseismic monitoring.To date,commonly used location methods have usually been based on the ray-tracing travel-time technique,which generally adopts an L1 or L2 norm to esta...Source location is the core foundation of microseismic monitoring.To date,commonly used location methods have usually been based on the ray-tracing travel-time technique,which generally adopts an L1 or L2 norm to establish the location objective function.However,the L1 norm usually achieves low location accuracy,whereas the L2 norm is easily affected by large P-wave arrival-time picking errors.In addition,traditional location methods may be affected by the initial iteration point used to find a local optimum location.Furthermore,the P-wave arrival-time data that have travelled long distances are usually poor in quality.To address these problems,this paper presents a microseismic source location method using the Log-Cosh function and distant sensor-removed P-wave arrival data.Its basic principles are as follows:First,the source location objective function is established using the Log-Cosh function.This function has the stability of the L1 norm and location accuracy of the L2 norm.Then,multiple initial points are generated randomly in the mining area,and the established Log-Cosh location objective function is used to obtain multiple corresponding location results.The average value of the 50 location points with the largest data field potential values is treated as the initial location result.Next,the P-wave travel times from the initial location result to triggered sensors are calculated,and then the P-wave arrival data with travel times exceeding 0.2 s are removed.Finally,the aforementioned location steps are repeated with the denoised P-wave arrival dataset to obtain a high-precision location result.Two synthetic events and eight blasting events from the Yongshaba mine,China,were used to test the proposed method.Regardless of whether the P-wave arrival data with long travel times were eliminated,the location error of the proposed method was smaller than that of the L1/L2 norm and trigger-time-based location method(TT1/TT2 method).Furthermore,after eliminating the Pwave arrival data with long travel distances,the location accuracy of these three location methods increased,indicating that the proposed location method has good application prospects.展开更多
On November 13, 2016, an MW7.8 earthquake struck Kaikoura in South Island of New Zealand. By means of back-projection of array recordings, ASTFs-analysis of global seismic recordings, and joint inversion of global sei...On November 13, 2016, an MW7.8 earthquake struck Kaikoura in South Island of New Zealand. By means of back-projection of array recordings, ASTFs-analysis of global seismic recordings, and joint inversion of global seismic data and co-seismic In SAR data, we investigated complexity of the earthquake source. The result shows that the 2016 MW7.8 Kaikoura earthquake ruptured about 100 s unilaterally from south to northeast(~N28°–33°E), producing a rupture area about 160 km long and about 50 km wide and releasing scalar moment 1.01×1021 Nm. In particular, the rupture area consisted of two slip asperities, with one close to the initial rupture point having a maximal slip value ~6.9 m while the other far away in the northeast having a maximal slip value ~9.3 m. The first asperity slipped for about 65 s and the second one started 40 s after the first one had initiated. The two slipped simultaneously for about 25 s.Furthermore, the first had a nearly thrust slip while the second had both thrust and strike slip. It is interesting that the rupture velocity was not constant, and the whole process may be divided into 5 stages in which the velocities were estimated to be 1.4 km/s, 0 km/s, 2.1 km/s, 0 km/s and 1.1 km/s, respectively. The high-frequency sources distributed nearly along the lower edge of the rupture area, the highfrequency radiating mainly occurred at launching of the asperities, and it seemed that no high-frequency energy was radiated when the rupturing was going to stop.展开更多
The source and evolution of ore-forming fluids is important to understand the genesis of Carlin-type gold deposit.Constraints on the source and evolution of ore fluid components by the con-ventional geochemical method...The source and evolution of ore-forming fluids is important to understand the genesis of Carlin-type gold deposit.Constraints on the source and evolution of ore fluid components by the con-ventional geochemical methods have long been a challenge due to the very fine-grained nature and complex textures of hydrothermal minerals in these deposits.In this study,we present the crush-leach analyzed solute data of fluid inclusion extracts within quartz,calcite,realgar,and fluorite from the Shuiyindong,Nibao,and Yata gold deposits in the Youjiang Basin,providing new insights into the source and evolution of ore-forming fluids.The results show that the high molar Cl/Br ratios up to 2508 in fluid inclusion extracts are indicative of a contribution of magmatic hydrothermal fluids.Flu-ids mixing between basinal and magmatic-hydrothermal fluids are evident on the plots of Cl/Br versus Na/K ratios,showing that ore-stage milky quartz near the magmatic-hydrothermal fluids reflects magma origin of the ore-forming fluids,whereas late ore-stage drusy quartz and realgar near the de-fined basinal fluids suggest the later input of basinal fluids in late-ore stage.Although the predominate-ly host rocks in Shuiyindong,Nibao and Yata gold deposit are bioclastic limestone,sedimentary tuff,and calcareous siltstone,respectively,the solute data of fluid inclusion extracts records they underwent the similar fluid-rocks reactions between the Na-rich magmatic hydrothermal fluids and the Ca-and Mg-rich host rocks.This study highlights the solute data of fluid inclusion extracts obtained by crush-leach analyses have the potential to fingerprint the source and evolution of ore-forming fluids of the Carlin-type gold deposit.展开更多
A 16 kV/20 A power supply was developed for the extraction grid of prototype radio frequency（RF） ion source of neutral beam injector. To acquire the state signals of extraction grid power supply（EGPS） and control ...A 16 kV/20 A power supply was developed for the extraction grid of prototype radio frequency（RF） ion source of neutral beam injector. To acquire the state signals of extraction grid power supply（EGPS） and control the operation of the EGPS, a data acquisition and control system has been developed. This system mainly consists of interlock protection circuit board, photoelectric conversion circuit, optical fibers, industrial compact peripheral component interconnect（CPCI） computer and host computer. The human machine interface of host computer delivers commands and data to program of the CPCI computer, as well as offers a convenient client for setting parameters and displaying EGPS status. The CPCI computer acquires the status of the power supply. The system can turn-off the EGPS quickly when the faults of EGPS occur. The system has been applied to the EGPS of prototype RF ion source. Test results show that the data acquisition and control system for the EGPS can meet the requirements of the operation of prototype RF ion source.展开更多
With its high repeatability,the airgun source has been used to monitor the temporal variations of subsurface structures. However,under different working conditions,there will be subtle differences in the airgun source...With its high repeatability,the airgun source has been used to monitor the temporal variations of subsurface structures. However,under different working conditions,there will be subtle differences in the airgun source signals. To some extent,deconvolution can eliminate changes of the recorded signals due to source variations. Generally speaking,in order to remove the airgun source wavelet signal and obtain the Green's functions between the airgun source and stations,we need to select an appropriate method to perform the deconvolution process for seismic waveform data. Frequency domain water level deconvolution and time domain iterative deconvolution are two kinds of deconvolution methods widely used in the field of receiver functions,etc. We use the Binchuan( in Yunnan Province,China) airgun data as an example to compare the performance of these two deconvolution methods in airgun source data processing. The results indicate that frequency domain water level deconvolution is better in terms of computational efficiency;time domain iterative deconvolution is better in terms of the signal-to-noise ratio( SNR),and the initial motion of P-wave is also clearer. We further discuss the sequence issue of deconvolution and stack for multiple-shot airgun data processing. Finally,we propose a general processing flow for the airgun source data to extract the Green 's functions between the airgun source and stations.展开更多
Real traffic information was analyzed in the statistical characteristics and approximated as a Gaussian time series. A data source model, called two states constant bit rate (TSCBR), was proposed in dynamic traffic mo...Real traffic information was analyzed in the statistical characteristics and approximated as a Gaussian time series. A data source model, called two states constant bit rate (TSCBR), was proposed in dynamic traffic monitoring sensor networks. Analysis of autocorrelation of the models shows that the proposed TSCBR model matches with the statistical characteristics of real data source closely. To further verify the validity of the TSCBR data source model, the performance metrics of power consumption and network lifetime was studied in the evaluation of sensor media access control (SMAC) algorithm. The simulation results show that compared with traditional data source models, TSCBR model can significantly improve accuracy of the algorithm evaluation.展开更多
The Digital Elevation Model(DEM)data of debris flow prevention engineering are the boundary of a debris flow prevention simulation,which provides accurate and reliable DEM data and is a key consideration in debris flo...The Digital Elevation Model(DEM)data of debris flow prevention engineering are the boundary of a debris flow prevention simulation,which provides accurate and reliable DEM data and is a key consideration in debris flow prevention simulations.Thus,this paper proposes a multi-source data fusion method.First,we constructed 3D models of debris flow prevention using virtual reality technology according to the relevant specifications.The 3D spatial data generated by 3D modeling were converted into DEM data for debris flow prevention engineering.Then,the accuracy and applicability of the DEM data were verified by the error analysis testing and fusion testing of the debris flow prevention simulation.Finally,we propose the Levels of Detail algorithm based on the quadtree structure to realize the visualization of a large-scale disaster prevention scene.The test results reveal that the data fusion method controlled the error rate of the DEM data of the debris flow prevention engineering within an allowable range and generated 3D volume data(obj format)to compensate for the deficiency of the DEM data whereby the 3D internal entity space is not expressed.Additionally,the levels of detailed method can dispatch the data of a large-scale debris flow hazard scene in real time to ensure a realistic 3D visualization.In summary,the proposed methods can be applied to the planning of debris flow prevention engineering and to the simulation of the debris flow prevention process.展开更多
基金funded by Haikou Science and Technology Plan Project(2022-007),in part by key Laboratory of PK System Technologies Research of Hainan,China.
文摘In the data transaction process within a data asset trading platform,quantifying the trustworthiness of data source nodes is challenging due to their numerous attributes and complex structures.To address this issue,a distributed data source trust assessment management framework,a trust quantification model,and a dynamic adjustment mechanism are proposed.Themodel integrates the Analytic Hierarchy Process(AHP)and Dempster-Shafer(D-S)evidence theory to determine attribute weights and calculate direct trust values,while the PageRank algorithm is employed to derive indirect trust values.Thedirect and indirect trust values are then combined to compute the comprehensive trust value of the data source.Furthermore,a dynamic adjustment mechanism is introduced to continuously update the comprehensive trust value based on historical assessment data.By leveraging the collaborative efforts of multiple nodes in the distributed network,the proposed framework enables a comprehensive,dynamic,and objective evaluation of data source trustworthiness.Extensive experimental analyses demonstrate that the trust quantification model effectively handles large-scale data source trust assessments,exhibiting both strong trust differentiation capability and high robustness.
基金supported by the National Natural Science Foundation of China(Nos.11775311 and U2067205)the Stable Support Basic Research Program Grant(BJ010261223282)the Research and Development Project of China National Nuclear Corporation。
文摘Lead(Pb)plays a significant role in the nuclear industry and is extensively used in radiation shielding,radiation protection,neutron moderation,radiation measurements,and various other critical functions.Consequently,the measurement and evaluation of Pb nuclear data are highly regarded in nuclear scientific research,emphasizing its crucial role in the field.Using the time-of-flight(ToF)method,the neutron leakage spectra from three^(nat)Pb samples were measured at 60°and 120°based on the neutronics integral experimental facility at the China Institute of Atomic Energy(CIAE).The^(nat)Pb sample sizes were30 cm×30 cm×5 cm,30 cm×30 cm×10 cm,and 30 cm×30 cm×15 cm.Neutron sources were generated by the Cockcroft-Walton accelerator,producing approximately 14.5 MeV and 3.5 MeV neutrons through the T(d,n)^(4)He and D(d,n)^(3)He reactions,respectively.Leakage neutron spectra were also calculated by employing the Monte Carlo code of MCNP-4C,and the nuclear data of Pb isotopes from four libraries:CENDL-3.2,JEFF-3.3,JENDL-5,and ENDF/B-Ⅷ.0 were used individually.By comparing the simulation and experimental results,improvements and deficiencies in the evaluated nuclear data of the Pb isotopes were analyzed.Most of the calculated results were consistent with the experimental results;however,a few areas did not fit well.In the(n,el)energy range,the simulated results from CENDL-3.2 were significantly overestimated;in the(n,inl)D and the(n,inl)C energy regions,the results from CENDL-3.2 and ENDF/B-Ⅷ.0 were significantly overestimated at 120°,and the results from JENDL-5 and JEFF-3.3 are underestimated at 60°in the(n,inl)D energy region.The calculated spectra were analyzed by comparing them with the experimental spectra in terms of the neutron spectrum shape and C/E values.The results indicate that the theoretical simulations,using different data libraries,overestimated or underestimated the measured values in certain energy ranges.Secondary neutron energies and angular distributions in the data files have been presented to explain these discrepancies.
基金supported by the National Natural Science Foundation of China(Nos.11775311,U2167203,U2067205 and 12075105)Research and development project of China National Nuclear Corporation(FD010241222552)+2 种基金Continuous-Support Basic Scientific Research Project(BJ010261223282)Major Science and Technology Projects of Gansu Province(22ZD6GB020)Fundamental Research Funds for the Central Universities(lzujbky-2024-jdzx10)。
文摘Beryllium(^(9)Be)serves as a crucial neutron multiplier and reflection material,being extensively employed in the nuclear industry.The evaluated nuclear data are utilized in the design of the nuclear devices.Following the interaction between neutrons and^(9)Be,all neutrons generated stem from the^(9)Be(n,2n)^(8)Be reaction channel,except for the elastic scattering reaction channel.Nevertheless,the data of the outgoing neutron double differential cross section of the reaction channel provided by the latest internationally evaluated libraries still exhibit considerable discrepancies.A shielding integral experiment based on slab^(9)Be samples with measurements of neutron spectra leaked from different angles is an effective approach to verify the double differential cross-section data.Hence,in this study,a shielding integral experiment of^(9)Be samples of different thicknesses was conducted using a nanosecond pulsed deuterium-tritium neutron source established by the China Institute of Atomic Energy.The neutron time-of-flight spectra of three thicknesses(4.4 cm,8.8 cm,and 13.2 cm)and six angles(47°,58°,73°,107°,122°,and 133°)were measured by the neutron time-of-flight method,and 18 sets of experimental data were obtained.Additionally,the MCNP-4C program was used to obtain the simulated results of the leakage neutron spectra using the evaluated nuclear data of^(9)Be from the CENDL-3.2,ENDF/B-Ⅷ.0,JENDL-5,and JEFF-3.3 libraries.The simulated results of the leakage neutron spectra were compared with the experimental results,and the results showed that in the elastic scattering energy region,the simulated results from the CENDL-3.2,ENDF/B-Ⅷ.0,and JENDL-5 libraries were slightly higher at small angles and slightly lower at large angles.In the(n,2n)energy region,the simulated results from the CENDL-3.2 library were significantly different from the experimental results in terms of spectral shape,and the simulated results from the ENDF/B-Ⅷ.0 and the JENDL-5 libraries were in good agreement with the experimental results at small angles but low at large angles.The simulated results from the JEFF-3.3 library showed serious underestimation at all angles.
基金supported by the Fundamental Research Funds for the Central Universities(WK2310000102)。
文摘Hefei Light Source(HLS)is a synchrotron radiation light source that primarily produces vacuum ultraviolet and soft X-rays.It currently consists of ten experimental stations,including a soft X-ray microscopy station.As part of its on-going efforts to establish a centralized scientific data management platform,HLS is in the process of developing a test sys-tem that covers the entire lifecycle of scientific data,including data generation,acquisition,processing,analysis,and de-struction.However,the instruments used in the soft X-ray microscopy experimental station rely on commercial propriet-ary software for data acquisition and processing.We developed a semi-automatic data acquisition program to facilitate the integration of soft X-ray microscopy stations into a centralized scientific data management platform.Additionally,we cre-ated an online data processing platform to assist users in analyzing their scientific data.The system we developed and de-ployed meets the design requirements,successfully integrating the soft X-ray microscopy station into the full lifecycle management of scientific data.
基金National Natural Science Foundation of China under Grant No.61973037China Postdoctoral Science Foundation under Grant No.2022M720419。
文摘Automatic modulation recognition(AMR)of radiation source signals is a research focus in the field of cognitive radio.However,the AMR of radiation source signals at low SNRs still faces a great challenge.Therefore,the AMR method of radiation source signals based on two-dimensional data matrix and improved residual neural network is proposed in this paper.First,the time series of the radiation source signals are reconstructed into two-dimensional data matrix,which greatly simplifies the signal preprocessing process.Second,the depthwise convolution and large-size convolutional kernels based residual neural network(DLRNet)is proposed to improve the feature extraction capability of the AMR model.Finally,the model performs feature extraction and classification on the two-dimensional data matrix to obtain the recognition vector that represents the signal modulation type.Theoretical analysis and simulation results show that the AMR method based on two-dimensional data matrix and improved residual network can significantly improve the accuracy of the AMR method.The recognition accuracy of the proposed method maintains a high level greater than 90% even at -14 dB SNR.
基金the research project is funded by Abdullah Alrushaid Chair for Earth Science Remote Sensing Research at King Saud University,Riyadh,Saudi Arabia.。
文摘Understanding the origins of potential source rocks and unraveling the intricate connections between reservoir oils and their source formations in the Siwa Basin(Western Desert,Egypt)necessitate a thorough oil-source correlation investigation.This objective is achieved through a meticulous analysis of well-log responses,Rock-Eval pyrolysis,and biomarker data.The analysis of Total Organic Carbon across 31 samples representing Paleozoic formations in the Siwa A-1X well reveals a spectrum of organic richness ranging from 0.17 wt%to 2.04 wt%,thereby highlighting diverse levels of organic content and the presence of both Type II and Type III kerogen.Examination of the fingerprint characteristics of eight samples from the well suggests that the Dhiffah Formation comprises a blend of terrestrial and marine organic matter.Notably,a significant contribution from more oxidized residual organic matter and gas-prone Type III kerogen is observed.Contrarily,the Desouky and Zeitoun formations exhibit mixed organic matter indicative of a transitional environment,and thus featuring a pronounced marine influence within a more reducing setting,which is associated with Type II kerogen.Through analysis of five oil samples from different wells—SIWA L-1X,SIWA R-3X,SIWA D-1X,PTAH 5X,and PTAH 6X,it is evident that terrestrial organic matter,augmented by considerable marine input,was deposited in an oxidizing environment,and contains Type III kerogen.Geochemical scrutiny confirms the coexistence of mixed terrestrial organic matter within varying redox environments.Noteworthy is the uniformity of identified kerogen Types II and III across all samples,known to have potential for hydrocarbon generation.The discovery presented in this paper unveils captivating prospects concerning the genesis of oil in the Jurassic Safa reservoir,suggesting potential links to Paleozoic sources or even originating from the Safa Member itself.These revelations mark a substantial advancement in understanding source rock dynamics and their intricate relationship with reservoir oils within the Siwa Basin.By illuminating the processes of hydrocarbon genesis in the region,this study significantly enriches our knowledge base.
文摘Aeromagnetic data over the Mamfe Basin have been processed. A regional magnetic gridded dataset was obtained from the Total Magnetic Intensity (TMI) data grid using a 3 × 3 convolution (Hanning) filter to remove regional trends. Major similarities in magnetic field orientation and intensities were observed at identical locations on both the regional and TMI data grids. From the regional and TMI gridded datasets, the residual dataset was generated which represents the very shallow geological features of the basin. Processing this residual data grid using the Source Parameter Imaging (SPI) for magnetic depth suggests that the estimated depths to magnetic sources in the basin range from about 271 m to 3552 m. The highest depths are located in two main locations somewhere around the central portion of the study area which correspond to the area with positive magnetic susceptibilities, as well as the areas extending outwards across the eastern boundary of the study area. Shallow magnetic depths are prominent towards the NW portion of the basin and also correspond to areas of negative magnetic susceptibilities. The basin generally exhibits a variation in depth of magnetic sources with high, average and shallow depths. The presence of intrusive igneous rocks was also observed in this basin. This characteristic is a pointer to the existence of geologic resources of interest for exploration in the basin.
文摘The real-time monitoring of environmental radiation dose for nuclear fa-cilities is an important part of safety, in order to guarantee the accuracy of the monitoring results regular calibration is necessary. Around nuclear facilities there are so many environmental dosimeters installed dispers-edly, because of its huge quantity, widely distributed, and in real-time monitoring state;it will cost lots of manpower and finance if it were tak-en to calibrate on standard laboratory;what’s more it will make the en-vironment out of control. To solve the problem of the measurement ac-curacy of the stationary gamma radiation dosimeter, an on-site calibra-tion method is proposed. The radioactive source is X-ray spectrum, and the dose reference instrument which has been calibrated by the national standard laboratory is a high pressure ionization. On-site calibration is divided into two parts;firstly the energy response experiment of dosim-eter for high and low energy is done in the laboratory, and the energy response curve is obtained combining with Monte Carlo simulation;sec-ondly experiment is carried out in the field of the measuring dosimeter, and the substitution method to calibrate the dosimeter is used;finally the calibration coefficient is gotten through energy curve correction. In order to verify the accuracy of on-site calibration method, the calibrated dosimeter is test in the standard laboratory and the error is 3.4%. The re-sult shows that the on-site calibration method using X-ray is feasible, and it can improves the accuracy of the measurement results of the stationary γ-ray instrument;what’s more important is that it has great reference value for the radiation safety management and radiation environment evaluation.
基金supported by the second Tibetan Plateau Scientific Expedition and Research Program(STEP,2019QZKK0606,2019QZKK0604)the National Natural Science Foundation of China(Grant No.41875183)。
文摘As part of“The Earth Summit Mission-2022”during the second Tibetan Plateau Scientific Expedition and Research(STEP)in April and May 2022,we conducted the ozone sounding experiment(an ozonesonde mated to a radiosonde)at Mt.Qomolangma Base Camp(MQBC;86.85°E,28.14°N;5200 m),a location at an extremely high altitude.A total of ten sounding profiles were obtained between April 30 and May 06,2022,of which seven profiles were above35 km in altitude,with a maximum detection altitude up to 39.0 km.This study presents the temporal variation and vertical distributions of atmospheric temperature,humidity,and ozone during the MQBC campaign.The averaged ozone concentration was high(68.3 ppbv)at the surface and then increased smoothly until peaking(~110 ppbv)in the middle troposphere(approximately 10 km),and afterward,the ozone concentration increased rapidly from the upper troposphere to a maximum of~10 ppmv at~30 km.The enhanced ozone concentration in the middle troposphere was associated with the blocking high pressure,and transport from the southern flank of the Himalayas occurred during the campaign period.The average total ozone column was 291.9±21.4 DU for the seven profiles exceeding 35km in altitude.The ozonesonde measurements were also compared with the vertical ozone profiles retrieved from the space-borne ozone products from the Microwave Limb Sounder(MLS)onboard the Aura satellite and the Atmospheric Infrared Sounder(AIRS)onboard the Aqua satellite.
基金funded by the Global Change Research Program of China (2010CB951401)the National Natural Science Foundation of China (41030638, 41121001, 41030527,41130641,and 41201025)the One Hundred Talents Program of the Chinese Academy of Sciences
文摘Water storage has important significance for understanding water cycles of global and local domains and for monitoring climate and environmental changes. As a key variable in hydrology, water storage change represents the sum of precipitation, evaporation, surface runoff, soil water and groundwater exchanges. Water storage change data during the period of 2003-2008 for the source region of the Yellow River were collected from Gravity Recovery and Climate Experiment （GRACE） satellite data. The monthly actual evaporation was estimated according to the water balance equation. The simulated actual evaporation was significantly consistent and correlative with not only the observed pan （20 cm） data, but also the simulated results of the version 2 of Simple Biosphere model. The average annual evaporation of the Tangnaihai Basin was 506.4 mm, where evaporation in spring, summer, autumn and winter was 130.9 mm, 275.2 mm, 74.3 mm and 26.1 mm, and accounted for 25.8%, 54.3%, 14.7% and 5.2% of the average annual evaporation, respectively, The precipitation increased slightly and the actual evaporation showed an obvious decrease. The water storage change of the source region of the Yellow River displayed an increase of 0.51 mm per month from 2003 to 2008, which indicated that the storage capacity has significantly increased, probably caused by the degradation of permafrost and the increase of the thickness of active layers. The decline of actual evaporation and the increase of water storage capacity resulted in the increase of river runoff.
文摘An earthquake of Ms= 6, 9 occurred at the Gonghe, Qinghai Province, China on April 26, 1990. Three larger aftershocks took place at the same region, Ms= 5. 0 on May 7, 1990, Ms= 6. 0 on Jan. 3, 1994 and Ms= 5. 7on Feb. 16, 1994. The long-period recordings of the main shock from China Digital Seismograph Network (CDSN) are deconvolved for the source time functions by the correspondent0 recordings of the three aftershocks asempirical Green's functions (EGFs). No matter which aftershock is taken as EGF, the relative source time functions (RSTFs) Obtained are nearly identical. The RSTFs suggest the Ms= 6. 9 event consists of at least two subevents with approximately equal size whose occurrence times are about 30 s apart, the first one has a duration of 12 s and a rise time of about 5 s, and the second one has a duration of 17 s and a rise time of about & s. COmParing the RSTFs obtained from P- and SH-phases respectively, we notice that those from SH-phases are a slightly more complex than those from p-phases, implying other finer subevents exist during the process of the main shock. It is interesting that the results from the EGF deconvolution of long-Period way form data are in good agreement with the results from the moment tensor inversion and from the EGF deconvolution of broadband waveform data. Additionally, the two larger aftershocks are deconvolved for their RSTFs. The deconvolution results show that the processes of the Ms= 6. 0 event on Jan. 3, 1994 and the Ms= 5. 7 event on Feb. 16,1994 are quite simple, both RSTFs are single impulses.The RSTFs of the Ms= 6. 9 main shock obtained from different stations are noticed to be azimuthally dependent, whose shapes are a slightly different with different stations. However, the RSTFs of the two smaller aftershocks are not azimuthally dependent. The integrations of RSTFs over the processes are quite close to each other, i. e., the scalar seismic moments estimated from different stations are in good agreement. Finally the scalar seismic moments of the three aftershocks are compared. The relative scalar seismic moment Of the three aftershocks deduced from the relative scalar seismic moments of the Ms=6. 9 main shock are very close to those inverted directly from the EGF deconvolution. The relative scalar seismic moment of the Ms =6. 9 main shock calculated using the three aftershocks as EGF are 22 (the Ms= 6. 0 aftershock being EGF), 26 (the Ms= 5. 7 aftershock being EGF) and 66 (the Ms= 5. 5 aftershock being EGF), respectively. Deducingfrom those results, the relative scalar sesimic moments of the Ms= 6. 0 to the Ms= 5. 7 events, the Ms= 6. 0 tothe Ms= 5. 5 events and the Ms= 5. 7 to the Ms= 5. 5 events are 1. 18, 3. 00 and 2. 54, respectively. The correspondent relative scalar seismic moments calculated directly from the waveform recordings are 1. 15, 3. 43, and 3. 05.
基金the NBI team and the partial support of National Natural Science Foundation of China (No. 61363019)National Natural Science Foundation of Qinghai Province (No. 2014-ZJ-718)
文摘As the key ion source component of nuclear fusion auxiliary heating devices, the radio frequency （RF） ion source is developed and applied gradually to offer a source plasma with the advantages of ease of control and high reliability. In addition, it easily achieves long-pulse steady-state operation. During the process of the development and testing of the RF ion source, a lot of original experimental data will be generated. Therefore, it is necessary to develop a stable and reliable computer data acquisition and processing application system for realizing the functions of data acquisition, storage, access, and real-time monitoring. In this paper, the development of a data acquisition and processing application system for the RF ion source is presented. The hardware platform is based on the PXI system and the software is programmed on the LabVIEW development environment. The key technologies that are used for the implementation of this software programming mainly include the long-pulse data acquisition technology, multi- threading processing technology, transmission control communication protocol, and the Lempel-Ziv-Oberhumer data compression algorithm. Now, this design has been tested and applied on the RF ion source. The test results show that it can work reliably and steadily. With the help of this design, the stable plasma discharge data of the RF ion source are collected, stored, accessed, and monitored in real-time. It is shown that it has a very practical application significance for the RF experiments.
文摘An earthquake of M S=6.9 occurred in Gonghe County, Qinghai Province, China on April 26, 1990.This earthquake was followed by three larger aftershocks of M S=5.5 on May 7, 1990, M S=6.0 on Jan.3, 1994, and M S=5.7 on Feb.16, 1994, consecutively. The moment tensors of these earthquakes as function of time were obtained by the technique of moment tensor inversion in frequency domain . The results inverted indicate that these earthquakes had a very similar focal mechanism of predominantly reverse faulting on a plane striking NWW, dipping to SSW.The scalar seismic moments of these earthquakes are M 0=9.4×10 18 Nm for the M S=6.9 event, 8.0×10 16 Nm for the M S=5.5 event, 4.9×10 17 Nm for the M S =6.0 event and 2.9×10 17 Nm for the M S=5.7 event, respectively. The results inverted also show that the source processes of these events were significantly different. The main shock had a very complex process, consisting of two distinct sub events with comparable sizes. The first sub event occurred in the first 12s, having a seismic moment of 4.7×10 18 Nm, and the second one continued from 31s to 41s, having a seismic moment of 2.5×10 18 Nm. In addition, a much smaller sub event, having a seismic moment of about 2.1×10 18 Nm, may exist in the interval of 12 s and 31 s, In contrast, the source processes of the three aftershocks are quite simple. The source time function of each of aftershocks is a single impulse, suggestting that each of aftershocks consists of a mainly uninterrupted rupture. The rise times and total rupture durations are 4 s and 11 s for the M S=5.5 event, 6 s and 16 s for the M S= 6.0 event and 6 s and 13 s for the M S=5.7 event, respectively.
基金Project(cstc2020jcyj-bshX0106)supported by the Chongqing Postdoctoral Science Foundation,ChinaProject(2020M683247)supported by the China Postdoctoral Science Foundation+1 种基金Project(cstc2020jcyj-zdxmX0023)supported by the Key Natural Science Foundation Project of Chongqing,ChinaProject(551974043)supported by the National Natural Science Foundation of China。
文摘Source location is the core foundation of microseismic monitoring.To date,commonly used location methods have usually been based on the ray-tracing travel-time technique,which generally adopts an L1 or L2 norm to establish the location objective function.However,the L1 norm usually achieves low location accuracy,whereas the L2 norm is easily affected by large P-wave arrival-time picking errors.In addition,traditional location methods may be affected by the initial iteration point used to find a local optimum location.Furthermore,the P-wave arrival-time data that have travelled long distances are usually poor in quality.To address these problems,this paper presents a microseismic source location method using the Log-Cosh function and distant sensor-removed P-wave arrival data.Its basic principles are as follows:First,the source location objective function is established using the Log-Cosh function.This function has the stability of the L1 norm and location accuracy of the L2 norm.Then,multiple initial points are generated randomly in the mining area,and the established Log-Cosh location objective function is used to obtain multiple corresponding location results.The average value of the 50 location points with the largest data field potential values is treated as the initial location result.Next,the P-wave travel times from the initial location result to triggered sensors are calculated,and then the P-wave arrival data with travel times exceeding 0.2 s are removed.Finally,the aforementioned location steps are repeated with the denoised P-wave arrival dataset to obtain a high-precision location result.Two synthetic events and eight blasting events from the Yongshaba mine,China,were used to test the proposed method.Regardless of whether the P-wave arrival data with long travel times were eliminated,the location error of the proposed method was smaller than that of the L1/L2 norm and trigger-time-based location method(TT1/TT2 method).Furthermore,after eliminating the Pwave arrival data with long travel distances,the location accuracy of these three location methods increased,indicating that the proposed location method has good application prospects.
基金supported by the NSFC project (41474046)the DQJB project (DQJB16B05) of the Institute of Geophysics, CEA
文摘On November 13, 2016, an MW7.8 earthquake struck Kaikoura in South Island of New Zealand. By means of back-projection of array recordings, ASTFs-analysis of global seismic recordings, and joint inversion of global seismic data and co-seismic In SAR data, we investigated complexity of the earthquake source. The result shows that the 2016 MW7.8 Kaikoura earthquake ruptured about 100 s unilaterally from south to northeast(~N28°–33°E), producing a rupture area about 160 km long and about 50 km wide and releasing scalar moment 1.01×1021 Nm. In particular, the rupture area consisted of two slip asperities, with one close to the initial rupture point having a maximal slip value ~6.9 m while the other far away in the northeast having a maximal slip value ~9.3 m. The first asperity slipped for about 65 s and the second one started 40 s after the first one had initiated. The two slipped simultaneously for about 25 s.Furthermore, the first had a nearly thrust slip while the second had both thrust and strike slip. It is interesting that the rupture velocity was not constant, and the whole process may be divided into 5 stages in which the velocities were estimated to be 1.4 km/s, 0 km/s, 2.1 km/s, 0 km/s and 1.1 km/s, respectively. The high-frequency sources distributed nearly along the lower edge of the rupture area, the highfrequency radiating mainly occurred at launching of the asperities, and it seemed that no high-frequency energy was radiated when the rupturing was going to stop.
基金This study is supported by the Natural Science Foundation of China(Nos.41802094,U1812402)the National Basic Research Program(No.2014CB440906).
文摘The source and evolution of ore-forming fluids is important to understand the genesis of Carlin-type gold deposit.Constraints on the source and evolution of ore fluid components by the con-ventional geochemical methods have long been a challenge due to the very fine-grained nature and complex textures of hydrothermal minerals in these deposits.In this study,we present the crush-leach analyzed solute data of fluid inclusion extracts within quartz,calcite,realgar,and fluorite from the Shuiyindong,Nibao,and Yata gold deposits in the Youjiang Basin,providing new insights into the source and evolution of ore-forming fluids.The results show that the high molar Cl/Br ratios up to 2508 in fluid inclusion extracts are indicative of a contribution of magmatic hydrothermal fluids.Flu-ids mixing between basinal and magmatic-hydrothermal fluids are evident on the plots of Cl/Br versus Na/K ratios,showing that ore-stage milky quartz near the magmatic-hydrothermal fluids reflects magma origin of the ore-forming fluids,whereas late ore-stage drusy quartz and realgar near the de-fined basinal fluids suggest the later input of basinal fluids in late-ore stage.Although the predominate-ly host rocks in Shuiyindong,Nibao and Yata gold deposit are bioclastic limestone,sedimentary tuff,and calcareous siltstone,respectively,the solute data of fluid inclusion extracts records they underwent the similar fluid-rocks reactions between the Na-rich magmatic hydrothermal fluids and the Ca-and Mg-rich host rocks.This study highlights the solute data of fluid inclusion extracts obtained by crush-leach analyses have the potential to fingerprint the source and evolution of ore-forming fluids of the Carlin-type gold deposit.
基金supported by National Natural Science Foundation of China(Contract Nos.11505225&11675216)Foundation of ASIPP(Contract No.DSJJ-15-GC03)the Key Program of Research and Development of Hefei Science Center,CAS(2016HSC-KPRD002)
文摘A 16 kV/20 A power supply was developed for the extraction grid of prototype radio frequency（RF） ion source of neutral beam injector. To acquire the state signals of extraction grid power supply（EGPS） and control the operation of the EGPS, a data acquisition and control system has been developed. This system mainly consists of interlock protection circuit board, photoelectric conversion circuit, optical fibers, industrial compact peripheral component interconnect（CPCI） computer and host computer. The human machine interface of host computer delivers commands and data to program of the CPCI computer, as well as offers a convenient client for setting parameters and displaying EGPS status. The CPCI computer acquires the status of the power supply. The system can turn-off the EGPS quickly when the faults of EGPS occur. The system has been applied to the EGPS of prototype RF ion source. Test results show that the data acquisition and control system for the EGPS can meet the requirements of the operation of prototype RF ion source.
基金jointly sponsored by the Special Fund for Earthquake Scientific Research in the Public Welfare of China Earthquake Administration(201508008)the tundamental Research Funds for the Central University(WK2080000053)Academician Chen Yong Workstation Project in Yunnan Province
文摘With its high repeatability,the airgun source has been used to monitor the temporal variations of subsurface structures. However,under different working conditions,there will be subtle differences in the airgun source signals. To some extent,deconvolution can eliminate changes of the recorded signals due to source variations. Generally speaking,in order to remove the airgun source wavelet signal and obtain the Green's functions between the airgun source and stations,we need to select an appropriate method to perform the deconvolution process for seismic waveform data. Frequency domain water level deconvolution and time domain iterative deconvolution are two kinds of deconvolution methods widely used in the field of receiver functions,etc. We use the Binchuan( in Yunnan Province,China) airgun data as an example to compare the performance of these two deconvolution methods in airgun source data processing. The results indicate that frequency domain water level deconvolution is better in terms of computational efficiency;time domain iterative deconvolution is better in terms of the signal-to-noise ratio( SNR),and the initial motion of P-wave is also clearer. We further discuss the sequence issue of deconvolution and stack for multiple-shot airgun data processing. Finally,we propose a general processing flow for the airgun source data to extract the Green 's functions between the airgun source and stations.
基金The National Natural Science Foundation ofChia(No60372076)The Important cienceand Technology Key Item of Shanghai Science and Technology Bureau ( No05dz15004)
文摘Real traffic information was analyzed in the statistical characteristics and approximated as a Gaussian time series. A data source model, called two states constant bit rate (TSCBR), was proposed in dynamic traffic monitoring sensor networks. Analysis of autocorrelation of the models shows that the proposed TSCBR model matches with the statistical characteristics of real data source closely. To further verify the validity of the TSCBR data source model, the performance metrics of power consumption and network lifetime was studied in the evaluation of sensor media access control (SMAC) algorithm. The simulation results show that compared with traditional data source models, TSCBR model can significantly improve accuracy of the algorithm evaluation.
基金support provided by the National Natural Sciences Foundation of China(No.41771419)Student Research Training Program of Southwest Jiaotong University(No.191510,No.182117)。
文摘The Digital Elevation Model(DEM)data of debris flow prevention engineering are the boundary of a debris flow prevention simulation,which provides accurate and reliable DEM data and is a key consideration in debris flow prevention simulations.Thus,this paper proposes a multi-source data fusion method.First,we constructed 3D models of debris flow prevention using virtual reality technology according to the relevant specifications.The 3D spatial data generated by 3D modeling were converted into DEM data for debris flow prevention engineering.Then,the accuracy and applicability of the DEM data were verified by the error analysis testing and fusion testing of the debris flow prevention simulation.Finally,we propose the Levels of Detail algorithm based on the quadtree structure to realize the visualization of a large-scale disaster prevention scene.The test results reveal that the data fusion method controlled the error rate of the DEM data of the debris flow prevention engineering within an allowable range and generated 3D volume data(obj format)to compensate for the deficiency of the DEM data whereby the 3D internal entity space is not expressed.Additionally,the levels of detailed method can dispatch the data of a large-scale debris flow hazard scene in real time to ensure a realistic 3D visualization.In summary,the proposed methods can be applied to the planning of debris flow prevention engineering and to the simulation of the debris flow prevention process.
