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A novel method for gamma spectrum analysis of low-level and intermediate-level radioactive waste 被引量:2
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作者 Hui Yang Xin-Yu Zhang +4 位作者 Wei-Guo Gu Bing Dong Xue-Zhi Jiang Wen-Tao Zhou De-Zhong Wang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第6期199-213,共15页
The uncertainty of nuclide libraries in the analysis of the gamma spectra of low-and intermediate-level radioactive waste(LILW)using existing methods produces unstable results.To address this problem,a novel spectral ... The uncertainty of nuclide libraries in the analysis of the gamma spectra of low-and intermediate-level radioactive waste(LILW)using existing methods produces unstable results.To address this problem,a novel spectral analysis method is proposed in this study.In this method,overlapping peaks are located using a continuous wavelet transform.An improved quadratic convolution method is proposed to calculate the widths of the peaks and establish a fourth-order filter model to estimate the Compton edge baseline with the overlapping peaks.Combined with the adaptive sensitive nonlinear iterative peak,this method can effectively subtracts the background.Finally,a function describing the peak shape as a filter is used to deconvolve the energy spectrum to achieve accurate qualitative and quantitative analyses of the nuclide without the aid of a nuclide library.Gamma spectrum acquisition experiments for standard point sources of Cs-137 and Eu-152,a segmented gamma scanning experiment for a 200 L standard drum,and a Monte Carlo simulation experiment for triple overlapping peaks using the closest energy of three typical LILW nuclides(Sb-125,Sb-124,and Cs-134)are conducted.The results of the experiments indicate that(1)the novel method and gamma vision(GV)with an accurate nuclide library have the same spectral analysis capability,and the peak area calculation error is less than 4%;(2)compared with the GV,the analysis results of the novel method are more stable;(3)the novel method can be applied to the activity measurement of LILW,and the error of the activity reconstruction at the equivalent radius is 2.4%;and(4)The proposed novel method can quantitatively analyze all nuclides in LILW without a nuclide library.This novel method can improve the accuracy and precision of LILW measurements,provide key technical support for the reasonable disposal of LILW,and ensure the safety of humans and the environment. 展开更多
关键词 HPGe detector Low-level and intermediate-level radioactive waste Gamma spectrum analysis method Deconvolution method Continuous wavelet transform
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Effect of drying cracks on swelling and self-healing of bentonite-sand blocks used as engineered barriers for radioactive waste disposal
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作者 Yu Tan Guangping Zhou +2 位作者 Huyuan Zhang Xiaoya Li Ping Liu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第5期1776-1787,共12页
Experiments were conducted to evaluate the healing of drying cracks in air-dried bentonite-sand blocks after hydration and swelling in groundwater,providing justifications to simplify the protection of blocks prior to... Experiments were conducted to evaluate the healing of drying cracks in air-dried bentonite-sand blocks after hydration and swelling in groundwater,providing justifications to simplify the protection of blocks prior to installation in a high-level radioactive waste repository.Synthetic groundwater was prepared to represent the geochemistry of Beishan groundwater,and was used to hydrate the blocks during the swelling pressure and swelling strain measurements,as Beishan is the most promising site for China's repository.Healing of the surface cracks was recorded by photography,and healing of the internal cracks was visualized by CT images and hydraulic conductivity of air-dried blocks.The results indicate that the maximum swelling pressure and swelling strain are primarily affected by the geochemistry of Beishan groundwater,but not affected by the drying cracks.The maximum swelling pressure and swelling strain of air-dried blocks are comparable to or even higher than the pressure and strain of fresh blocks.The maximum swelling pressure measured in strong(i.e.high ion strength)Beishan groundwater was 44%of the pressure measured in deionized(DI)water,and the maximum swelling strain was reduced to 23%of the strain measured in DI water.Nevertheless,the remained swelling of the blocks hydrated in strong Beishan groundwater was sufficient to heal the surface and internal drying cracks,as demonstrated by the pictures of surface cracks and CT images.The hydraulic conductivity of the air-dried block permeated with strong groundwater was comparable(3.7×higher)to the hydraulic conductivity of the fresh block,indicating the self-healing of drying cracks after hydration and swelling in groundwater.A simplified method of protecting the block with plastic wraps before installation is recommended,since the remained swelling of the block hydrated in Beishan groundwater is sufficient to heal the drying cracks. 展开更多
关键词 Beishan groundwater chemistry Bentonite buffer Drying cracks High-level radioactive waste(HLW) SELF-HEALING SWELLING
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Relationship between Whole Body Iodine-131 Effective Half-Life and Estimated Glomerular Filtration Rate for Papillary Thyroid Cancer Patients Undergoing Radioactive Iodine Therapy
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作者 Asim Abualnaja Hanaa Alsheikh +2 位作者 Khaled Soliman Meshal Alnefaie Abdulraheem Alsheri 《Journal of Applied Mathematics and Physics》 2023年第8期2472-2479,共8页
Background: The aim of this work was to examine the relationship between the estimated glomerular filtration rate (eGFR) as indicator of renal efficiency potentially related to the ability to release radioactive iodin... Background: The aim of this work was to examine the relationship between the estimated glomerular filtration rate (eGFR) as indicator of renal efficiency potentially related to the ability to release radioactive iodine from the patients bodies and the radioactive iodine whole body effective half-life (WBEHL) defined as the time taken for the administered activity to decay to half of its value for papillary thyroid cancer (PTC) patients undergoing radioactive iodine therapy (RAIT) in a tertiary care medical Centre. Methods: This retrospective observational study included seventy nine patients, sixty females and nineteen males. The patients were divided in two subgroups, those who have WBEHL of less than 11 hours (n = 51) and those with more than 11 (n = 28) hrs based on k-means clustering technique. Results: Analysis of variance (ANOVA) was used to find out if there is a statistically significant difference between the two subgroups Conclusion: There was not a statistically significant difference between the short and the longer WBEHL patients’ groups analyzed in this study. . 展开更多
关键词 GFR Thyroid Cancer radioactive Iodine Therapy Renal Function
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Analysis of Morphometric Parameters and Radioactive Characteristics Using Remote Sensing Data and GIS Techniques in the Wadi Wizr Basin Area, Central Eastern Desert, Egypt
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作者 Sameh Anwar Ibrahim Hammouda Soliman Abu Elatta A. Mahmoud 《Journal of Geoscience and Environment Protection》 2023年第6期197-219,共23页
The purpose of this study is to demonstrate how modern technologies such as geographic information systems (GIS) and digital elevation models can help in the creation of a geographic database for the Wadi Wizr basin i... The purpose of this study is to demonstrate how modern technologies such as geographic information systems (GIS) and digital elevation models can help in the creation of a geographic database for the Wadi Wizr basin in Egypt’s Central Eastern Desert, in addition to examining and analysing the radioactive properties of various rocks. This was accomplished with the help of a digital elevation model (DEM) with a 30 metre accuracy and GIS software in 10.8 Arc Map. The RS-230 was also used to measure uranium and thorium concentrations. GIS softwares and digital elevation models have been shown to be more effective than the traditional method. This was demonstrated by the flexible and quick working method, the accuracy of the parameters used, and the results of the morphometric analysis of the basin river network. In addition to, the main drainage pattern from subtype to tree type, where the branching ratio was (1.59). This basin could also cause flooding. Similar studies, according to the results of this study, should make greater use of geographic information system technology and modern data sources. Wadi Wizr also has a radioactive anomaly, with uranium equivalent concentrations reaching 70 ppm in some fault parts. 展开更多
关键词 Wadi Wizr Basin Morphometric Analysis Drainage Pattern radioactive Characteristics Remote Sensing Geographic Information System
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Short-term efficacy assessment of transarterial chemoembolization combined with radioactive iodine therapy in primary hepatocellular carcinoma
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作者 Lei Wang Kun Huang +6 位作者 Yu Zhang Yi-Fan Wu Zhen-Dong Yue Zhen-Hua Fan Fu-Quan Liu Yong-Wu Li Jian Dong 《World Journal of Gastrointestinal Surgery》 SCIE 2023年第1期105-113,共9页
BACKGROUND Transarterial chemoembolization(TACE)is an effective treatment for primary hepatocellular carcinoma(PHC).Radioactive iodine therapy has been used in the treatment of advanced PHC,especially in patients with... BACKGROUND Transarterial chemoembolization(TACE)is an effective treatment for primary hepatocellular carcinoma(PHC).Radioactive iodine therapy has been used in the treatment of advanced PHC,especially in patients with portal vein tumor thrombosis.However,data on the therapeutic effect of TACE combined with radioactive iodine therapy in PHC are scarce.AIM To investigate the clinical efficacy of TACE combined with radioactive iodine implantation therapy in advanced PHC via perfusion computed tomography(CT).METHODS For this study,98 advanced PHC patients were recruited and divided randomly into the study and control groups.Patients in the study group were treated with TACE combined radioactive iodine implantation therapy.Patients in the control group were treated with only TACE.The tumor lesion length,clinical effect,serum alpha-fetoprotein(AFP)and CT perfusion parameters were compared before and after therapy,and statistical analysis was performed.RESULTS There was no significant difference in tumor length and serum AFP between the study and control groups(P>0.05)before treatment.However,the tumor length and serum AFP in the study group were lower than those in the control group 1 mo and 3 mo after therapy.After 3 mo of treatment,the complete and partial remission rate of the study group was 93.88%,which was significantly higher than the control group(77.55%)(P<0.05).Before treatment,there were no significant differences between the two groups on the perfusion CT variables,including the lesion blood volume,permeability surface,blood flow,hepatic artery flow and mean transit time(P>0.05).After 3 mo of treatment,all perfusion CT variables were lower in the study group compared to the control group(P<0.05).The survival time of patients in the study group was 22 mo compared to 18 mo in the control group,which was significantly different[log rank(Mantel-Cox)=4.318,P=0.038].CONCLUSION TACE combined with radioactive iodine implantation in the treatment of advanced PHC can inhibit the formation of blood vessels in tumor tissue and reduce the perfusion level of tumor lesions,thereby improving the clinical efficacy and prolonging the survival time of patients. 展开更多
关键词 Transarterial chemoembolization radioactive iodine Primary hepatocellular carcinoma PERFUSION Computed tomography
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Heuristic techniques for maximum likelihood localization of radioactive sources via a sensor network
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作者 Assem Abdelhakim 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第8期174-193,共20页
Maximum likelihood estimation(MLE)is an effective method for localizing radioactive sources in a given area.However,it requires an exhaustive search for parameter estimation,which is time-consuming.In this study,heuri... Maximum likelihood estimation(MLE)is an effective method for localizing radioactive sources in a given area.However,it requires an exhaustive search for parameter estimation,which is time-consuming.In this study,heuristic techniques were employed to search for radiation source parameters that provide the maximum likelihood by using a network of sensors.Hence,the time consumption of MLE would be effectively reduced.First,the radiation source was detected using the k-sigma method.Subsequently,the MLE was applied for parameter estimation using the readings and positions of the detectors that have detected the radiation source.A comparative study was performed in which the estimation accuracy and time consump-tion of the MLE were evaluated for traditional methods and heuristic techniques.The traditional MLE was performed via a grid search method using fixed and multiple resolutions.Additionally,four commonly used heuristic algorithms were applied:the firefly algorithm(FFA),particle swarm optimization(PSO),ant colony optimization(ACO),and artificial bee colony(ABC).The experiment was conducted using real data collected by the Low Scatter Irradiator facility at the Savannah River National Laboratory as part of the Intelligent Radiation Sensing System program.The comparative study showed that the estimation time was 3.27 s using fixed resolution MLE and 0.59 s using multi-resolution MLE.The time consumption for the heuristic-based MLE was 0.75,0.03,0.02,and 0.059 s for FFA,PSO,ACO,and ABC,respectively.The location estimation error was approximately 0.4 m using either the grid search-based MLE or the heuristic-based MLE.Hence,heuristic-based MLE can provide comparable estimation accuracy through a less time-consuming process than traditional MLE. 展开更多
关键词 radioactive source Maximum likelihood estimation Multi-resolution MLE k-sigma Firefly algorithm Particle swarm optimization Ant colony optimization Artificial bee colony
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Rapid progression of heart failure secondary to radioactive iodine treatment of hyperthyroidism:A case report
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作者 Zi-Han Li Lu-Jia Ni +1 位作者 Yuan-Qiao Liu Dao-Yuan Si 《World Journal of Clinical Cases》 SCIE 2023年第22期5316-5321,共6页
BACKGROUND The deterioration of thyroid health is involved in the progression of heart failure(HF).This is usually a lengthy process,so there are almost no reports on its rapid development.Here we report a case of a y... BACKGROUND The deterioration of thyroid health is involved in the progression of heart failure(HF).This is usually a lengthy process,so there are almost no reports on its rapid development.Here we report a case of a young male who rapidly developed hypothyroid cardiomyopathy secondary to radioactive iodine treatment,suggesting that severe HF might occur even after a short period of hypothyroidism.CASE SUMMARY A 26-year-old man was referred to our hospital for HF presenting with dyspnea on exertion and chest discomfort lasting for 1 mo.He received radioactive iodine treatment for hyperthyroidism 1 year ago and had an almost normal echocardiogram 6 mo ago.Admission echocardiogram and cardiac magnetic resonance(CMR)revealed left ventricle(LV)global hypokinesia and severely depressed systolic function.In addition,late gadolinium enhancement indicated no obvious changes in the myocardium.Thyroid function tests showed decreased serum levels of thyroid hormone(TH)and elevated thyroid-stimulating hormone.Based on an exclusionary examination,the patient was diagnosed with hypothyroid cardiomyopathy and was started on replacement therapy.His HF symptoms were completely relieved during the six-month follow-up,and echocardiogram and CMR revealed recovered LV size and ejection fraction.CONCLUSION This report demonstrates that severe fluctuations in TH levels may lead to acute HF,which can completely recover with timely thyroid hormone replacement.In addition,our findings highlight the importance of routinely detecting cardiac function in patients treated with radioactive iodine. 展开更多
关键词 Heart failure Hypothyroid cardiomyopathy Hormone replacement therapy radioactive iodine therapy Case report
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Novel algorithm for detection and identification of radioactive materials in an urban environment
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作者 Hao-Lin Liu Hai-Bo Ji +3 位作者 Jiang-Mei Zhang Jing Lu Cao-Lin Zhang Xing-Hua Feng 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第10期103-116,共14页
This study introduces a novel algorithm to detect and identify radioactive materials in urban settings using time-series detector response data. To address the challenges posed by varying backgrounds and to enhance th... This study introduces a novel algorithm to detect and identify radioactive materials in urban settings using time-series detector response data. To address the challenges posed by varying backgrounds and to enhance the quality and reliability of the energy spectrum data, we devised a temporal energy window. This partitioned the time-series detector response data, resulting in energy spectra that emphasize the vital information pertaining to radioactive materials. We then extracted characteristic features of these energy spectra, relying on the formation mechanism and measurement principles of the gammaray instrument spectrum. These features encompassed aggregated counts, peak-to-flat ratios, and peak-to-peak ratios. This methodology not only simplified the interpretation of the energy spectra's physical significance but also eliminated the necessity for peak searching and individual peak analyses. Given the requirements of imbalanced multi-classification, we created a detection and identification model using a weighted k-nearest neighbors(KNN) framework. This model recognized that energy spectra of identical radioactive materials exhibit minimal inter-class similarity. Consequently, it considerably boosted the classification accuracy of minority classes, enhancing the classifier's overall efficacy. We also executed a series of comparative experiments. Established methods for radionuclide identification classification, such as standard KNN, support vector machine, Bayesian network, and random tree, were used for comparison purposes. Our proposed algorithm realized an F1 measure of 0.9868 on the time-series detector response data, reflecting a minimum enhancement of 0.3% in comparison with other techniques. The results conclusively show that our algorithm outperforms others when applied to time-series detector response data in urban contexts. 展开更多
关键词 Gamma-ray spectral analysis Nuclide identification Urban environment Temporal energy window Peakratio spectrum analysis Weighted KNN
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Dynamic Update Scheme of Spectrum Information Based on Spectrum Opportunity Incentive in the Database-Assisted Dynamic Spectrum Management
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作者 Zhang Yu Chen Yong +1 位作者 He Panfeng Cai Yueming 《China Communications》 SCIE CSCD 2024年第3期75-90,共16页
To solve the problem of delayed update of spectrum information(SI) in the database assisted dynamic spectrum management(DB-DSM), this paper studies a novel dynamic update scheme of SI in DB-DSM. Firstly, a dynamic upd... To solve the problem of delayed update of spectrum information(SI) in the database assisted dynamic spectrum management(DB-DSM), this paper studies a novel dynamic update scheme of SI in DB-DSM. Firstly, a dynamic update mechanism of SI based on spectrum opportunity incentive is established, in which spectrum users are encouraged to actively assist the database to update SI in real time. Secondly, the information update contribution(IUC) of spectrum opportunity is defined to describe the cost of accessing spectrum opportunity for heterogeneous spectrum users, and the profit of SI update obtained by the database from spectrum allocation. The process that the database determines the IUC of spectrum opportunity and spectrum user selects spectrum opportunity is mapped to a Hotelling model. Thirdly, the process of determining the IUC of spectrum opportunities is further modelled as a Stackelberg game by establishing multiple virtual spectrum resource providers(VSRPs) in the database. It is proved that there is a Nash Equilibrium in the game of determining the IUC of spectrum opportunities by VSRPs. Finally, an algorithm of determining the IUC based on a genetic algorithm is designed to achieve the optimal IUC. The-oretical analysis and simulation results show that the proposed method can quickly find the optimal solution of the IUC, and ensure that the spectrum resource provider can obtain the optimal profit of SI update. 展开更多
关键词 database-assisted dynamic spectrum management HOTELLING information updating contribution spectrum information updating STACKELBERG
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Correction:Brillouin scattering spectrum for liquid detection and applications in oceanography
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作者 Yuanqing Wang Jinghao Zhang +6 位作者 Yongchao Zheng Yangrui Xu Jiaqi Xu Jiao Jiao Yun Su Hai-Feng Lü Kun Liang 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2024年第1期47-47,共1页
After publication of this article1,it was brought to our at-tention that the mathematical expressions‘‰’were mis-takenly replaced by‘%’for salinities.Details are listed below.1.In the last sentence in abstract,“... After publication of this article1,it was brought to our at-tention that the mathematical expressions‘‰’were mis-takenly replaced by‘%’for salinities.Details are listed below.1.In the last sentence in abstract,“approximately 0.1℃and 0.5%”should be“approximately 0.1℃and 0.5‰”. 展开更多
关键词 SCATTERING LISTED spectrum
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Construction of a Cu@hollow TS-1 nanoreactor based on a hierarchical full-spectrum solar light utilization strategy for photothermal synergistic artificial photosynthesis
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作者 Sixian Zhu Qiao Zhao +5 位作者 Hongxia Guo Li Liu Xiao Wang Xiwei Qi Xianguang Meng Wenquan Cui 《Carbon Energy》 SCIE EI CAS CSCD 2024年第2期25-36,共12页
The artificial photosynthesis technology has been recognized as a promising solution for CO_(2) utilization.Photothermal catalysis has been proposed as a novel strategy to promote the efficiency of artificial photosyn... The artificial photosynthesis technology has been recognized as a promising solution for CO_(2) utilization.Photothermal catalysis has been proposed as a novel strategy to promote the efficiency of artificial photosynthesis by coupling both photochemistry and thermochemistry.However,strategies for maximizing the use of solar spectra with different frequencies in photothermal catalysis are urgently needed.Here,a hierarchical full-spectrum solar light utilization strategy is proposed.Based on this strategy,a Cu@hollow titanium silicalite-1 zeolite(TS-1)nanoreactor with spatially separated photo/thermal catalytic sites is designed to realize high-efficiency photothermal catalytic artificial photosynthesis.The space-time yield of alcohol products over the optimal catalyst reached 64.4μmol g−1 h−1,with the selectivity of CH3CH2OH of 69.5%.This rationally designed hierarchical utilization strategy for solar light can be summarized as follows:(1)high-energy ultraviolet light is utilized to drive the initial and difficult CO_(2) activation step on the TS-1 shell;(2)visible light can induce the localized surface plasmon resonance effect on plasmonic Cu to generate hot electrons for H2O dissociation and subsequent reaction steps;and(3)low-energy near-infrared light is converted into heat by the simulated greenhouse effect by cavities to accelerate the carrier dynamics.This work provides some scientific and experimental bases for research on novel,highly efficient photothermal catalysts for artificial photosynthesis. 展开更多
关键词 artificial photosynthesis full spectrum NANOREACTORS photothermal catalysis
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Floquet spectrum and universal dynamics of a periodically driven two-atom system
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作者 谢文柱 周正强 +2 位作者 李轩 崔思淼 孙明远 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期436-443,共8页
We investigate the Floquet spectrum and excitation properties of a two-ultracold-atom system with periodically driven interaction in a three-dimensional harmonic trap.The interaction between the atoms is changed by va... We investigate the Floquet spectrum and excitation properties of a two-ultracold-atom system with periodically driven interaction in a three-dimensional harmonic trap.The interaction between the atoms is changed by varying the s-wave scattering length in two ways,the cosine and the square-wave modulations.It is found that as the driving frequency increases,the Floquet spectrum exhibits two main features for both modulations,the accumulating and the spreading of the quasienergy levels,which further lead to different dynamical behaviors.The accumulation is associated with collective excitations and the persistent growth of the energy,while the spread indicates that the energy is bounded at all times.The initial scattering length,the driving frequency and amplitude can all significantly change the Floquet spectrum as well as the dynamics.However,the corresponding relation between them is valid universally.Finally,we propose a mechanism for selectively exciting the system to one specific state by using the avoided crossing of two quasienergy levels,which could guide preparation of a desired state in experiments. 展开更多
关键词 Floquet spectrum universal dynamics two-atom system avoided crossing
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Comparison of inebilizumab or rituximab in addition to glucocorticoid therapy for neuromyelitis optica spectrum disorders
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作者 Chu-Yuan Lou Yong Wang +4 位作者 Jia-Yuan Xing Teng Ma Lei Tao Xiao-Tang Wang Run-Sheng Wang 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第6期1073-1078,共6页
AIM:To investigate the short-term efficacy and safety of inebilizumab for neuromyelitis optica spectrum disorders(NMOSD).METHODS:A total of 33 patients with NMOSD treated with inebilizumab(Group INB,n=15)or rituximab(... AIM:To investigate the short-term efficacy and safety of inebilizumab for neuromyelitis optica spectrum disorders(NMOSD).METHODS:A total of 33 patients with NMOSD treated with inebilizumab(Group INB,n=15)or rituximab(Group RTX,n=18)in addition to high-dose glucocorticoids were included.Both groups underwent hormone shock therapy during the acute phase.Subsequently,Group INB received inebilizumab injections during the remission phase,while Group RTX received rituximab injections.A comparison of aquaporins 4(AQP4)titer values,peripheral blood B lymphocyte counts,and visual function recovery was conducted before and 8wk after treatment.Additionally,adverse reactions and patient tolerability were analyzed after using inebilizumab treatment regimes.RESULTS:Following inebilizumab treatment,there was a significantly improvement in the visual acuity of NMOSD patients(P<0.05),accompanied by a notable decrease in AQP4 titer values and B lymphocyte ratio(P<0.05).Moreover,inebilizumab treatment showed a partial effect in preventing optic nerve atrophy(P<0.05).However,there were no significant differences in other therapeutic effects compared to rituximab,which has previously demonstrated substantial therapeutic efficacy(P>0.05).Furthermore,inebilizumab exhibited higher safety levels than that of rituximab injections.CONCLUSION:The combination of inebilizumab and high-dose glucocorticoids proves to be effective.In comparison to rituximab injections,inebilizumab displays better tolerance and safety.Moreover,it demonstrates a partial effect in preventing optic nerve atrophy.Thus,it stands as an effective method to reduce the disability rates and improve the daily living ability of patients with NMOSD. 展开更多
关键词 neuromyelitis optica spectrum disorders inebilizumab RITUXIMAB GLUCOCORTICOIDS
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Blockchain-Based MCS Detection Framework of Abnormal Spectrum Usage for Satellite Spectrum Sharing Scenario
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作者 Ning Yang Heng Wang +3 位作者 Jingming Hu Bangning Zhang Daoxing Guo Yuan Liu 《China Communications》 SCIE CSCD 2024年第2期32-48,共17页
In this paper, the problem of abnormal spectrum usage between satellite spectrum sharing systems is investigated to support multi-satellite spectrum coexistence. Given the cost of monitoring, the mobility of low-orbit... In this paper, the problem of abnormal spectrum usage between satellite spectrum sharing systems is investigated to support multi-satellite spectrum coexistence. Given the cost of monitoring, the mobility of low-orbit satellites, and the directional nature of their signals, traditional monitoring methods are no longer suitable, especially in the case of multiple power level. Mobile crowdsensing(MCS), as a new technology, can make full use of idle resources to complete a variety of perceptual tasks. However, traditional MCS heavily relies on a centralized server and is vulnerable to single point of failure attacks. Therefore, we replace the original centralized server with a blockchain-based distributed service provider to enable its security. Therefore, in this work, we propose a blockchain-based MCS framework, in which we explain in detail how this framework can achieve abnormal frequency behavior monitoring in an inter-satellite spectrum sharing system. Then, under certain false alarm probability, we propose an abnormal spectrum detection algorithm based on mixed hypothesis test to maximize detection probability in single power level and multiple power level scenarios, respectively. Finally, a Bad out of Good(BooG) detector is proposed to ease the computational pressure on the blockchain nodes. Simulation results show the effectiveness of the proposed framework. 展开更多
关键词 blockchain hypothesis test mobile crowdsensing satellite communication spectrum sharing
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Periodic signal extraction of GNSS height time series based on adaptive singular spectrum analysis
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作者 Chenfeng Li Peibing Yang +1 位作者 Tengxu Zhang Jiachun Guo 《Geodesy and Geodynamics》 EI CSCD 2024年第1期50-60,共11页
Singular spectrum analysis is widely used in geodetic time series analysis.However,when extracting time-varying periodic signals from a large number of Global Navigation Satellite System(GNSS)time series,the selection... Singular spectrum analysis is widely used in geodetic time series analysis.However,when extracting time-varying periodic signals from a large number of Global Navigation Satellite System(GNSS)time series,the selection of appropriate embedding window size and principal components makes this method cumbersome and inefficient.To improve the efficiency and accuracy of singular spectrum analysis,this paper proposes an adaptive singular spectrum analysis method by combining spectrum analysis with a new trace matrix.The running time and correlation analysis indicate that the proposed method can adaptively set the embedding window size to extract the time-varying periodic signals from GNSS time series,and the extraction efficiency of a single time series is six times that of singular spectrum analysis.The method is also accurate and more suitable for time-varying periodic signal analysis of global GNSS sites. 展开更多
关键词 GNSS Time series Singular spectrum analysis Trace matrix Periodic signal
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Occurrence of K1 and K2 serotypes and genotypic characteristics of extended spectrumβ-lactamases-producing Klebsiella pneumoniae isolated from selected hospitals in Malaysia
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作者 Nurul Syazrah Anuar Hazmin Hazman +5 位作者 Sharven Raj Jeyakumar Mohd Nasir Mohd Desa Hasni Idayu Saidi Siti Norbaya Masri Nur Afiza Aziz Nurshahira Sulaiman 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2024年第1期30-38,共9页
Objective:To determine the distribution,phenotypic and genetic background of extended spectrumβ-lactamases(ESBL)-producing Klebsiella(K.)pneumoniae clinical isolates associated with K1 and K2 serotypes in two selecte... Objective:To determine the distribution,phenotypic and genetic background of extended spectrumβ-lactamases(ESBL)-producing Klebsiella(K.)pneumoniae clinical isolates associated with K1 and K2 serotypes in two selected hospitals in Malaysia.Methods:A total of 192 K.pneumoniae isolates were collected and subjected to antibiotic susceptibility,hypermucoviscosity test and multiplex PCR to detect the presence of K1-and K2-serotype associated genes.Multilocus sequence typing(MLST)was performed on ESBL-producing K.pneumoniae isolates presented with K1 and K2 serotypes,followed by phylogenetic analysis.Results:A total of 87 out of 192(45.3%)of the K.pneumoniae isolates collected were ESBL producers.However,only 8.3%(16/192)and 10.9%(21/192)of the total isolates were detected to carry K1-and K2-serotype associated genes,respectively.Statistical analysis showed that K1 and K2 capsular serotypes were not significantly associated with ESBL phenotype(P=0.196).However,they were significantly associated with hypervirulent,as demonstrated by the positive string test(P<0.001).MLST analysis revealed that ST23 as the predominant sequence type(ST)in the K1 serotype,while the ST in the K2 serotype is more diverse.Conclusions:Although the occurrence of ESBL-producing isolates among the hypervirulent strains was low,their coexistence warrants the need for continuous surveillance.MLST showed that these isolates were genetically heterogeneous. 展开更多
关键词 Extended spectrumβ-lactamases Klebsiella pneumoniae Capsular serotypes GENOTYPIC
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Exploring impedance spectrum for lithium-ion batteries diagnosis and prognosis:A comprehensive review
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作者 Xinghao Du Jinhao Meng +2 位作者 Yassine Amirat Fei Gao Mohamed Benbouzid 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期464-483,I0010,共21页
Lithium-ion batteries have extensive usage in various energy storage needs,owing to their notable benefits of high energy density and long lifespan.The monitoring of battery states and failure identification are indis... Lithium-ion batteries have extensive usage in various energy storage needs,owing to their notable benefits of high energy density and long lifespan.The monitoring of battery states and failure identification are indispensable for guaranteeing the secure and optimal functionality of the batteries.The impedance spectrum has garnered growing interest due to its ability to provide a valuable understanding of material characteristics and electrochemical processes.To inspire further progress in the investigation and application of the battery impedance spectrum,this paper provides a comprehensive review of the determination and utilization of the impedance spectrum.The sources of impedance inaccuracies are systematically analyzed in terms of frequency response characteristics.The applicability of utilizing diverse impedance features for the diagnosis and prognosis of batteries is further elaborated.Finally,challenges and prospects for future research are discussed. 展开更多
关键词 Lithium-ion battery Impedance spectrum Temperature monitoring Failure diagnosis Health prognosis
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Aquaporin-4-IgG-seropositive neuromyelitis optica spectrum disorders:progress of experimental models based on disease pathogenesis
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作者 Li Xu Huiming Xu Changyong Tang 《Neural Regeneration Research》 SCIE CAS 2025年第2期354-365,共12页
Neuromyelitis optica spectrum disorders are neuroinflammatory demyelinating disorders that lead to permanent visual loss and motor dysfunction.To date,no effective treatment exists as the exact causative mechanism rem... Neuromyelitis optica spectrum disorders are neuroinflammatory demyelinating disorders that lead to permanent visual loss and motor dysfunction.To date,no effective treatment exists as the exact causative mechanism remains unknown.Therefore,experimental models of neuromyelitis optica spectrum disorders are essential for exploring its pathogenesis and in screening for therapeutic targets.Since most patients with neuromyelitis optica spectrum disorders are seropositive for IgG autoantibodies against aquaporin-4,which is highly expressed on the membrane of astrocyte endfeet,most current experimental models are based on aquaporin-4-IgG that initially targets astrocytes.These experimental models have successfully simulated many pathological features of neuromyelitis optica spectrum disorders,such as aquaporin-4 loss,astrocytopathy,granulocyte and macrophage infiltration,complement activation,demyelination,and neuronal loss;however,they do not fully capture the pathological process of human neuromyelitis optica spectrum disorders.In this review,we summarize the currently known pathogenic mechanisms and the development of associated experimental models in vitro,ex vivo,and in vivo for neuromyelitis optica spectrum disorders,suggest potential pathogenic mechanisms for further investigation,and provide guidance on experimental model choices.In addition,this review summarizes the latest information on pathologies and therapies for neuromyelitis optica spectrum disorders based on experimental models of aquaporin-4-IgG-seropositive neuromyelitis optica spectrum disorders,offering further therapeutic targets and a theoretical basis for clinical trials. 展开更多
关键词 AQUAPORIN-4 experimental model neuromyelitis optica spectrum disorder PATHOGENESIS
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Increased Mortality Risk in Children with Fetal Alcohol Spectrum Disorders: A Scoping Review
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作者 Devin Evavold Tyler Mueller +2 位作者 Erika Johnson Marilyn G. Klug Larry Burd 《Open Journal of Pediatrics》 2024年第4期754-766,共13页
Objective: Fetal Alcohol Spectrum Disorders (FASDs) are common, often undiagnosed, lifelong developmental disorders that result from prenatal alcohol exposure. FASD is present at birth and typically identified around ... Objective: Fetal Alcohol Spectrum Disorders (FASDs) are common, often undiagnosed, lifelong developmental disorders that result from prenatal alcohol exposure. FASD is present at birth and typically identified around seven years of age. The most severe outcome in cases of FASD is mortality. The purpose of this scoping review is to 1) use a systematic review to provide an estimated mortality proportion for children with FASD, and 2) update a study published in 2014 by reviewing published reports of mortality in individuals diagnosed with FASD. Method: A search of PubMed, CINAHL, and Google Scholar for reports published between 2013 and 2023 on mortality in individuals with FASD. Results: Three population-based studies have reported on all-cause mortality rates, finding a combined mortality rate of 10.9%, a 2.63 fold (95% CI: 2.61 to 2.65) increase in mortality risk over the general population. Since 2016, this review identified only eight new cases meeting the study inclusion criteria. The reported causes of death were five cases of pneumonia, and one case each of failure to thrive and dehydration, intestinal dilatation and asphyxiation caused by overeating due to pica, and acute gastric volvulus. Discussion: While current research suggests a diagnosis of FASD is associated with a 2.6-fold increase in mortality risk, this is likely an underestimation, as most cases of FASD-related mortality go unreported. Globally, about 1 new case is reported every 15 months. However, in the United States alone, between 1752 to 4400 FASD related deaths occur annually. Our review suggests that FASD is rarely identified as a causal or contributing factor in deaths of children and adolescents, resulting in a substantial undercount of FASD-related deaths. Increased attention to the role of FASD in infant and child mortality case reviews, child death review committee reports, and mortality reviews is needed. 展开更多
关键词 Fetal Alcohol spectrum Disorders MORTALITY Birth Defects DEATH EXPOSURE PNEUMONIA
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Is a Mini-Screen for Fetal Alcohol Spectrum Disorder Feasible?
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作者 Tyler Mueller Devin Evavold +2 位作者 June-Yung Kim Marilyn G. Klug Larry Burd 《Open Journal of Pediatrics》 2024年第4期767-781,共15页
Background: Fetal Alcohol Spectrum Disorders (FASDs) are a global public health concern with lifelong consequences for affected individuals. Recent prevalence studies suggest FASD prevalence rates range from 1-5% amon... Background: Fetal Alcohol Spectrum Disorders (FASDs) are a global public health concern with lifelong consequences for affected individuals. Recent prevalence studies suggest FASD prevalence rates range from 1-5% among school age children. Most people with FASD are not correctly diagnosed and inadequate screening to identify patients with increased risk may contribute to under-diagnosis. This study developed a 10-item screening tool for FASD and examined its feasibility. Methods: The sample consisted of 355 children who had been evaluated at an FASD clinic. Data from the 33-item Alcohol Related Neurodevelopmental Disorder Behavioral Checklist was used to develop a brief FASD screen by comparing the changes in Cronbach’s alpha for different combinations of items. The validity of the brief scale was then further examined using receiving operating characteristic analyses. Results: The 10-item screen demonstrated acceptable sensitivity, specificity, and accuracy to identify children at high risk for FASD. The percentage correctly classified was 91.3 and the area under the receiving operating characteristic curve was 0.971. Conclusions: This feasibility study demonstrated that a screen for FASD consisting of 10 items with yes or no responses can be completed in 3 - 4 minutes. The tool is brief, with a low administration burden and has acceptable epidemiologic performance characteristics including accuracy. Future research should examine the performance of this tool when used in larger, community-based populations where screening for FASD would be appropriate. 展开更多
关键词 Fetal Alcohol spectrum Disorders (FASDs) CHILDREN SCREENING PREVALENCE
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