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Analytical solutions to the precession relaxation of magnetization with uniaxial anisotropy
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作者 张泽南 贾镇林 薛德胜 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期656-660,共5页
Based on the Landau-Lifshitz-Gilbert(LLG)equation,the precession relaxation of magnetization is studied when the external field H is parallel to the uniaxial anisotropic field H_(k).The evolution of three-component ma... Based on the Landau-Lifshitz-Gilbert(LLG)equation,the precession relaxation of magnetization is studied when the external field H is parallel to the uniaxial anisotropic field H_(k).The evolution of three-component magnetization is solved analytically under the condition of H=nH_(k)(n=3,1 and 0).It is found that with an increase of H or a decrease of the initial polar angle of magnetization,the relaxation time decreases and the angular frequency of magnetization increases.For comparison,the analytical solution for H_(k)=0 is also given.When the magnetization becomes stable,the angular frequency is proportional to the total effective field acting on the magnetization.The analytical solutions are not only conducive to the understanding of the precession relaxation of magnetization,but also can be used as a standard model to test the numerical calculation of LLG equation. 展开更多
关键词 precession relaxation Landau-Lifshitz-Gilbert(LLG)equation uniaxial anisotropy analytical solutions
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Solid-state impedance spectroscopy studies of dielectric properties and relaxation processes in Na_(2)O–V_(2)O_(5)–Nb_(2)O_(5)–P_(2)O_(5) glass
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作者 Sara Marijan Luka Pavic 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CSCD 2024年第1期186-196,共11页
Solid-state impedance spectroscopy(SS-IS)was used to investigate the influence of structural modifications resulting from the addition of Nb2O5 on the dielectric properties and relaxation processes in the quaternary m... Solid-state impedance spectroscopy(SS-IS)was used to investigate the influence of structural modifications resulting from the addition of Nb2O5 on the dielectric properties and relaxation processes in the quaternary mixed glass former(MGF)system 35Na_(2)O–10V_(2)O_(5)–(55-x)P_(2)O_(5)–xNb_(2)O_(5)(x=0–40,mol%).The dielectric parameters,including the dielectric strength and dielectric loss,are determined from the frequency and temperature-dependent complex permittivity data,revealing a significant dependence on the Nb2O5 content.The transition from a predominantly phosphate glass network(x<10,region I)to a mixed niobate–phosphate glass net-work(10≤x≤20,region II)leads to an increase in the dielectric parameters,which correlates with the observed trend in the direct-cur-rent(DC)conductivity.In the predominantly niobate network(x≥25,region III),the highly polarizable nature of Nb5+ions leads to a fur-ther increase in the dielectric permittivity and dielectric strength.This is particularly evident in Nb-40 glass-ceramic,which contains Na_(13)Nb_(35)O_(94) crystalline phase with a tungsten bronze structure and exhibits the highest dielectric permittivity of 61.81 and the lowest loss factor of 0.032 at 303 K and 10 kHz.The relaxation studies,analyzed through modulus formalism and complex impedance data,show that DC conductivity and relaxation processes are governed by the same mechanism,attributed to ionic conductivity.In contrast to glasses with a single peak in frequency dependence of imaginary part of electrical modulus,M″(ω),Nb-40 glass-ceramic exhibits two distinct contributions with similar relaxation times.The high-frequency peak indicates bulk ionic conductivity,while the additional low-fre-quency peak is associated with the grain boundary effect,confirmed by the electrical equivalent circuit(EEC)modelling.The scaling characteristics of permittivity and conductivity spectra,along with the electrical modulus,validate time-temperature superposition and demonstrate a strong correlation with composition and modification of the glass structure upon Nb_(2)O_(5) incorporation. 展开更多
关键词 phosphate glasses GLASS-CERAMICS impedance spectroscopy dielectric properties relaxation processes permittivity scaling conductivity scaling modulus formalism
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Effectiveness of aromatherapy with lavender compared to progressive muscle relaxation on anxiety and vital signs in patients under spinal anesthesia:A randomized clinical trial
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作者 Nazanin AMINI Safoora OMIDVAR +2 位作者 Masoomeh Noruzi ZAMENJANI Mehdi HARORANI Hesameddin MODIR 《Journal of Integrative Nursing》 2024年第2期90-95,共6页
Objective:This study aimed to determine the effectiveness of aromatherapy with lavender essential oil compared to progressive muscle relaxation(PMR)on anxiety and vital signs of patients under spinal anesthesia.Materi... Objective:This study aimed to determine the effectiveness of aromatherapy with lavender essential oil compared to progressive muscle relaxation(PMR)on anxiety and vital signs of patients under spinal anesthesia.Materials and Methods:This clinical trial was conducted on 120 spinal anesthesia candidates who were randomly assigned into three groups of 40 including control,PMR(Jacobsen group),and aromatherapy.The state-trait anxiety inventory was completed on surgery day and 15 min after the end of the intervention by the samples of all three groups,and at the same time as completing the questionnaire,vital signs were also measured and recorded.Results:The mean score of anxiety after intervention was lower than that before the intervention in the aromatherapy group(P<0.001).The mean score of anxiety in the aromatherapy group was significantly lower than that in the Jacobsen group(P<0.001).Moreover,data analysis showed a significant decrease in the mean arterial blood pressure scores of the PMR(P=008)and aromatherapy(P<0.001)groups and a statistically significant increase in the mean heart rate scores in the control group(P=0.002).Conclusion:The use of aromatherapy with lavender is more effective than PMR therapy in reducing the anxiety level of patients undergoing spinal anesthesia.Due to the high level of anxiety and its serious effects on the patient’s hemodynamics,aromatherapy with lavender can be used as an easy and cheap method to reduce anxiety in operation rooms. 展开更多
关键词 ANXIETY AROMATHERAPY lavender essential oil MASSAGE progressive muscle relaxation spinal anesthesia vital signs
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Photoelectric State with Long-Term Relaxation in CdTe:(Ag, Cu, Cd) and Sb2Se3:Se Photovoltaic Films
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作者 Ozodbek Ravshanboy o‘g‘li Nurmatov Dilkhumor Tolibjonovna Mamadieva Nosirjon Khaydarovich Yuldashev 《Journal of Applied Mathematics and Physics》 2024年第1期43-51,共9页
The results of an experimental study of long-term relaxation of the photoelectret state of polycrystalline CdTe:(Ag, Cu, Cd) and Sb<sub>2</sub>Se<sub>3</sub>:Se films with an anomalous photovol... The results of an experimental study of long-term relaxation of the photoelectret state of polycrystalline CdTe:(Ag, Cu, Cd) and Sb<sub>2</sub>Se<sub>3</sub>:Se films with an anomalous photovoltaic property are presented. In such films, the residual photovoltage is caused by the separation of photocarriers by the built-in electrostatic field of the near-surface region of space charges and their asymmetric capture by deep levels of impurities or complexes, including impurity atoms and intrinsic defects, both in the bulk and on the surface of crystal grains. It has been shown that in activated films, a two-step exponential temporary relaxation of the initial photovoltage of the order of V<sub>APV</sub> ≈ (500-600) V is detected, and only 10% of it experiences long-term relaxation (t ≈ 100-120 min). 展开更多
关键词 Thin Polycrystalline Films Doping Deep Centers Anomalous Photovoltage Photoelectret State Long-Term relaxation
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Improved Algorithm for Efficient Extraction of Relaxation Parameter Values from Wideband Permittivity of Baijiu
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作者 Haoyan Yu Qi Jin +1 位作者 Zhaozong Meng Zhen Li 《Instrumentation》 2024年第1期62-69,共8页
The complex permittivity of baijiu varies with frequency,and dielectric spectroscopy has been used to evaluate the quality.To simplify the analysis and reduce the number of the parameters,a dielectric relaxation model... The complex permittivity of baijiu varies with frequency,and dielectric spectroscopy has been used to evaluate the quality.To simplify the analysis and reduce the number of the parameters,a dielectric relaxation model is often used to fit the permittivity data.However,existing fitting methods such as the least squares and particle swarm optimization methods are often computationally complex and require preset initial values.Therefore,a simpler calculation method of the relaxation parameters considering the geometric characteristics of the permittivity spectrum is proposed.It is based on the relationship between the Cole-Cole relaxation parameters and the Cole-Cole diagram,which is fitted by a geometric method.First,the concepts of the Cole-Cole parameters and the diagram are introduced,and then the process of obtaining the parameters from the complex permittivity measurement data is explained.Taking baijiu with 56%alcohol by volume(ABV)as an example,the fitting is better than the least squares method and similar to the particle swarm optimization.This method is then used for the parameter fitting of baijiu with ABV of 42-52%,and the average error is less than 1%,demonstrating its wider applicability.Finally,a prediction model is used for baijiu with 53%ABV,and the error is only 1.51%.Hence,the method can be applied to the measurement of ABV of baijiu. 展开更多
关键词 PERMITTIVITY cole-cole equation relaxation parameters alcohol by volume baijiu
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Effects of relaxation breathing exercise on fatigue and cortisol level among Indonesian gynecological cancer patients undergoing chemotherapy:a pilot study
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作者 Mulhaeriah Mulhaeriah Mohammad Syafar Sangkala +1 位作者 Syahrul Syahrul Rezki Wahyuni 《Frontiers of Nursing》 2024年第2期201-208,共8页
Objective:This study aimed to determine the effect of the relaxation breathing exercise(RBE)on fatigue and cortisol levels among Indonesian women with gynecological cancer undergoing chemotherapy.Methods:This pilot st... Objective:This study aimed to determine the effect of the relaxation breathing exercise(RBE)on fatigue and cortisol levels among Indonesian women with gynecological cancer undergoing chemotherapy.Methods:This pilot study consecutively recruited 44 gynecological cancer patients to receive RBE(22)or usual care(22).Cortisol level was measured before and after completion of the intervention(day 8).Fatigue was measured using the Piper Fatigue Scale(PFS).Anxiety and depression were assessed using the Hospital Anxiety and Depression Scale(HADS)at the baseline days of the study for days 1,4,and 8.The obtained data were analyzed using Fisher’s exact test,the independent t-test,and the Mann-Whitney U test.Results:There were significant increases in cortisol levels within the groups,either the intervention or control groups,respectively(P-value=0.0003 and 0.001).Despite there being no statistical significance between the intervention and control groups,there were noticeable differences in the cortisol levels,indicating the extreme increase in cortisol levels in the control group(Median[IQR1-IQR3]:2.30[0.99-9.09];Min-Max:0.43-23.38)compared with the intervention group(Median[IQR1-IQR3]=2.97[1.26-5.18];Min-Max=0.39-6.91).Conclusions:RBE helps prevent a significant increase in cortisol levels that can alleviate fatigue for women with gynecological cancer.Further research was recommended to compare several intervention modalities for fatigue and cancer-related symptom management based on cortisol level changes. 展开更多
关键词 ANXIETY CORTISOL FATIGUE gynecological cancer relaxation breathing exercise
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A Bibliometric Study on The Application of Progressive Muscle Relaxation Training in The Nursing Field in China
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作者 Chengwen Shi Feifan Zhao +4 位作者 Yingshuo Wang Chengxuan Liu Aiyu Mao Siqi Ji Ruixiao Lu 《Journal of Clinical and Nursing Research》 2024年第4期14-21,共8页
Objective:To systematically analyze the research status and application of progressive muscle relaxation training(PMRT)in the nursing field in China,and provide a reference basis for scientific research in this field.... Objective:To systematically analyze the research status and application of progressive muscle relaxation training(PMRT)in the nursing field in China,and provide a reference basis for scientific research in this field.Methods:The bibliometric method was adopted in“progressive muscle relaxation training”or“PMRT,”and“nursing.”The established database was included in the China National Knowledge Infrastructure(CNKI)and the Wanfang Medical Network.The relevant articles in the Chinese Science and Technology Periodical Database(VIP)were analyzed.Results:A total of 169 literatures were included.The journals,years,and regions of literature publication were uneven,mainly originating from the eastern region(43.19%),and listed the application of progressive muscle relaxation training in the field of nursing in China.Intervention literature information was mainly dominated by experimental studies(97%).Conclusion:The related research and application of progressive muscle relaxation training in nursing in China is increasing,but there is a lack of objective evaluation of outcome indicators and a short intervention period.Further research should be conducted in the future to effectively guide the development of PMRT in the field of nursing in China. 展开更多
关键词 Progressive muscle relaxation training Nursing practice BIBLIOMETRICS
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Effects of Progressive Muscle Relaxation Training on Anxiety, Depression, and Quality of Life in Patients with Cerebral Small Vessel Disease
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作者 Chengwen Shi Feifan Zhao +3 位作者 Yingshuo Wang Chengxuan Liu Aiyu Mao Siqi Jin 《Journal of Clinical and Nursing Research》 2024年第5期283-292,共10页
Objective:To explore the effects of progressive muscle relaxation training on anxiety,depression,and quality of life in patients with cerebral small vessel disease(CSVD).Methods:Sixty-one patients with CSVD in the Dep... Objective:To explore the effects of progressive muscle relaxation training on anxiety,depression,and quality of life in patients with cerebral small vessel disease(CSVD).Methods:Sixty-one patients with CSVD in the Department of Neurology of a tertiary hospital were divided into an observation group(28 patients)and a control group(33 patients)by lottery method.The control group received conventional nursing care,while the observation group received progressive muscle relaxation training interventions in addition to the conventional care.The Hamilton Anxiety Scale(HAMA),the Hamilton Depression Scale(HAMD),and the Stroke-Specific Quality of Life Scale(SS-QOL)were used to compare the effects before the intervention,7 days after the intervention,and 30 days after the intervention.Results:Over time,at different time points after the intervention,the anxiety and depression scores of patients with CSVD in the observation group were significantly lower than those in the control group(P<0.05).The quality of life scores were significantly higher in the observation group compared to the control group(P<0.05),and these differences were statistically significant.Conclusion:Progressive muscle relaxation training can improve anxiety and depression in patients with cerebral small vessel disease and can effectively enhance their quality of life. 展开更多
关键词 Progressive muscle relaxation training Cerebral small vessel disease(CSVD) ANXIETY DEPRESSION Quality of life
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Treatment and surveillance for non-muscle-invasive bladder cancer:a clinical practice guideline(2021 edition) 被引量:1
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作者 Ying-Hui Jin Xian-Tao Zeng +31 位作者 Tong-Zu Liu Zhi-Ming Bai Zhong-Ling Dou De-Gang Ding Zhi-Lu Fan Ping Han Yi-Ran Huang Xing Huang Ming Li Xiao-Dong Li Yi-Ning Li Xu-Hui Li Chao-Zhao Liang Jiu-Min Liu Hong-Shun Ma Juan Qi Jia-Qi Shi Jian Wang De-Lin Wang Zhi-Ping Wang Yun-Yun Wang Yong-Bo Wang Qiang Wei Hai-Bo Xia Jin-Chun Xing Si-Yu Yan Xue-Pei Zhang Guo-You Zheng Nian-Zeng Xing Da-Lin He Xing-Huan Wang on behalf of the Chinese Urological Doctor Association(CUDA),Urological Association of Chinese Research Hospital Association(CRHA-UA),Uro-Health Promotive Association of China International Exchange,Promotive Association for Medical,Health Care(CPAM-UHPA) 《Military Medical Research》 SCIE CAS CSCD 2023年第2期141-161,共21页
Non-muscle invasive bladder cancer(NMIBC)is a major type of bladder cancer with a high incidence worldwide,resulting in a great disease burden.Treatment and surveillance are the most important part of NIMBC management... Non-muscle invasive bladder cancer(NMIBC)is a major type of bladder cancer with a high incidence worldwide,resulting in a great disease burden.Treatment and surveillance are the most important part of NIMBC management.In 2018,we issued“Treatment and surveillance for non-muscle-invasive bladder cancer in China:an evidencebased clinical practice guideline”.Since then,various studies on the treatment and surveillance of NMIBC have been published.There is a need to incorporate these materials and also to take into account the relatively limited medical resources in primary medical institutions in China.Developing a version of guideline which takes these two issues into account to promote the management of NMIBC is therefore indicated.We formed a working group of clinical experts and methodologists.Through questionnaire investigation of clinicians including primary medical institutions,24 clinically concerned issues,involving transurethral resection of bladder tumor(TURBT),intravesical chemotherapy and intravesical immunotherapy of NMIBC,and follow-up and surveillance of the NMIBC patients,were determined for this guideline.Researches and recommendations on the management of NMIBC in databases,guideline development professional societies and monographs were referred to,and the European Association of Urology was used to assess the certainty of generated recommendations.Finally,we issued 29 statements,among which 22 were strong recommendations,and 7 were weak recommendations.These recommendations cover the topics of TURBT,postoperative chemotherapy after TURBT,Bacillus Calmette–Guérin(BCG)immunotherapy after TURBT,combination treatment of BCG and chemotherapy after TURBT,treatment of carcinoma in situ,radical cystectomy,treatment of NMIBC recurrence,and follow-up and surveillance.We hope these recommendations can help promote the treatment and surveillance of NMIBC in China,especially for the primary medical institutions. 展开更多
关键词 non-muscle invasive bladder cancer Bladder cancer Transurethral resection of bladder tumor TREATMENT SURVEILLANCE GUIDELINE
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Data-driven optimization study of the multi-relaxation-time lattice Boltzmann method for solid-liquid phase change 被引量:1
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作者 Yanlin REN Zhaomiao LIU +1 位作者 Zixiao KANG Yan PANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第1期159-172,共14页
Sharp phase interfaces and accurate temperature distributions are important criteria in the simulation of solid-liquid phase changes.The multi-relaxation-time lattice Boltzmann method(MRT-LBM)shows great numerical per... Sharp phase interfaces and accurate temperature distributions are important criteria in the simulation of solid-liquid phase changes.The multi-relaxation-time lattice Boltzmann method(MRT-LBM)shows great numerical performance during simulation;however,the value method of the relaxation parameters needs to be specified.Therefore,in this study,a random forest(RF)model is used to discriminate the importance of different relaxation parameters to the convergence,and a support vector machine(SVM)is used to explore the decision boundary of the convergent samples in each dimensional model.The results show that the convergence of the samples is consistent with the sign of the decision number,and two types of the numerical deviations appear,i.e.,the phase mushy zone and the non-physical heat transfer.The relaxation parameters chosen on the decision boundary can further suppress the numerical bias and improve numerical accuracy. 展开更多
关键词 solid-liquid phase change lattice Boltzmann method(LBM) relaxation parameter random forest(RF) support vector machine(SVM)
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A Th2-score in the tumor microenvironment as a predictive biomarker of response to Bacillus Calmette Guérin in patients with non-muscle invasive bladder carcinoma:A retrospective study
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作者 GUSTAVO MARTÍN VILLOLDO MARÍA TERESA POMBO +11 位作者 MARIANA ARIS JOAQUÍN CHEMI PABLO MANDÓ SUPRIYA NAGARAJU JUAN CAMEAN ADRIÁN BURIONI DEBORAH EGEA MORA AMAT JOSÉLEÓN MELLADO JOSÉMORDOH ALBERTO VILLARONGA MARÍA MARCELA BARRIO 《Oncology Research》 SCIE 2023年第2期207-220,共14页
Intravesical Bacillus Calmette Guerin(BCG)is the gold standard therapy for intermediate/high-risk nonmuscle invasive bladder cancer(NMIBC).However,the response rate is~60%,and 50%of non-responders will progress to mus... Intravesical Bacillus Calmette Guerin(BCG)is the gold standard therapy for intermediate/high-risk nonmuscle invasive bladder cancer(NMIBC).However,the response rate is~60%,and 50%of non-responders will progress to muscle-invasive disease.BCG induces massive local infiltration of inflammatory cells(Th1)and ultimately cytotoxic tumor elimination.We searched for predictive biomarker of BCG response by analyzing tumor-infiltrating lymphocyte(TIL)polarization in the tumor microenvironment(TME)in pre-treatment biopsies.Pre-treatment biopsies from patients with NMIBC who received adequate intravesical instillation of BCG(n=32)were evaluated retrospectively by immunohistochemistry.TME polarization was assessed by quantifying the T-Bet+(Th1)and GATA-3+(Th2)lymphocyte ratio(G/T),and the density and degranulation of EPX+eosinophils.In addition,PD-1/PD-L1 staining was quantified.The results correlated with BCG response.In most non-responders,Th1/Th2 markers were compared in pre-and post-BCG biopsies.ORR was 65.6%in the study population.BCG responders had a higher G/T ratio and a greater number of degranulated EPX+cells.Variables combined into a Th2-score showed a significant association with higher scores in responders(p=0.027).A Th2-score cut-off value>48.1 allowed discrimination of responders with 91%sensitivity but lower specificity.Relapse-free survival was significantly associated with the Th2-score(p=0.007).In post-BCG biopsies from recurring patients,TILs increased Th2-polarization,probably reflecting BCG failure to induce a pro-inflammatory status and,thus,a lack of response.PD-L1/PD-1 expression was not associated with the response to BCG.Our results support the hypothesis that a preexisting Th2-polarized TME predicts a better response to BCG,assuming a reversion to Th1 polarization and antitumor activity. 展开更多
关键词 non-muscle invasive bladder cancer BCG predictive biomarkers Lymphocyte polarization
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Unusual magnetic relaxation in a single-molecule magnet with toroidal magnetic moments
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作者 苏丹 张义权 +1 位作者 刘恩克 孙阳 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第8期446-449,共4页
We report the synthesis and characterization of a single-molecule magnet composed of triangular clusters of dysprosium ions.The structural study shows that the symmetry changes from one polar point group(mm2)at room t... We report the synthesis and characterization of a single-molecule magnet composed of triangular clusters of dysprosium ions.The structural study shows that the symmetry changes from one polar point group(mm2)at room temperature to another polar point group(m)at low temperature.Magnetic studies and theory calculations illustrate that the vortex distribution of magnetic dipoles in the triangular dysprosium clusters forms a toroidal magnetic moment.Interestingly,the analysis of AC magnetic susceptibility reveals the coexistence of three distinct magnetic relaxation processes,corresponding to the Raman,Orbach,and QTM relaxation pathways,respectively.The sum of three modified Debye functions is successfully used to describe the multiple relaxation behavior. 展开更多
关键词 single-molecule magnet magnetic relaxation toroidal moment
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Relaxation of Ne^(1+)1s^(0)2s^(2)2p^(6)np produced by resonant excitation of an ultraintense ultrafast x-ray pulse
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作者 闫杰 刘彦鹏 +4 位作者 侯永 高城 吴建华 曾交龙 袁建民 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第6期75-79,共5页
The creation and relaxation of double K-hole states 1s^(0)2s^(2)2p^(6)np(n≥3)of Ne^(1+)in the interaction with ultraintense ultrafast x-ray pulses are theoretically investigated.The x-ray photon energies are selected... The creation and relaxation of double K-hole states 1s^(0)2s^(2)2p^(6)np(n≥3)of Ne^(1+)in the interaction with ultraintense ultrafast x-ray pulses are theoretically investigated.The x-ray photon energies are selected so that x-rays first photoionize1s^(22)s^(22)p^(6) of a neon atom to create a single K-hole state of 1s2s^(22)p^(6) of Ne^(1+),which is further excited resonantly to double K-hole states of ls^(0)2s^(2)2p^(6)np(n≥3).A time-dependent rate equation is used to investigate the creation and relaxation processes of 1s^(0)2s^(2)2p^(6)np,where the primary microscopic atomic processes including photoexcitation,spontaneous radiation,photoionization and Auger decay are considered.The calculated Auger electron energy spectra are compared with recent experimental results,which shows good agreement.The relative intensity of Auger electrons is very sensitive to the photon energy and bandwidth of x-ray pulses,which could be used as a diagnostic tool for x-ray free electron laser and atom experiments. 展开更多
关键词 hollow atoms x-ray resonant excitation relaxation
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GLOBAL SOLUTIONS TO A HYDRODYNAMIC MODEL FOR SEMICONDUCTORS WITH VELOCITY RELAXATION
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作者 王先婷 陆云光 +1 位作者 Richard De la cruz 尤国桥 《Acta Mathematica Scientia》 SCIE CSCD 2023年第2期975-980,共6页
In this paper,we apply the method given in the paper“Zero relaxation time limits to a hydrodynamic model of two carrier types for semiconductors”(Mathematische Annalen,2022,382:1031–1046)to study the Cauchy problem... In this paper,we apply the method given in the paper“Zero relaxation time limits to a hydrodynamic model of two carrier types for semiconductors”(Mathematische Annalen,2022,382:1031–1046)to study the Cauchy problem for a one dimensional inhomogeneous hydrodynamic model of two-carrier types for semiconductors with the velocity relaxation. 展开更多
关键词 global L solution hydrodynamic model two-carrier types velocity relaxation
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Functional group resolved NMR relaxation of 3-carbon adsorbates in mesoporous alumina
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作者 Neil Robinson Carmine D’Agostino Michael LJohns 《Magnetic Resonance Letters》 2023年第3期248-255,I0004,共9页
NMR relaxation analysis provides a unique and non-invasive probe of fluid dynamics within porous materials,and may be applied to the interpretation of a wide variety of material and interfacial characteristics.Here,we... NMR relaxation analysis provides a unique and non-invasive probe of fluid dynamics within porous materials,and may be applied to the interpretation of a wide variety of material and interfacial characteristics.Here,we report two-dimensional^(1)H T_(1)-T_(2)relaxation correlation measurements of a range of three-carbon adsorbates(1-propanol,2-propanol and propanoic acid)imbibed within the mesoporous metal oxide gamma-alumina.Our data,acquired across field strengths of 2 MHz,12.7 MHz and 43 MHz,clearly reveal two populations in each measurement,identified as the alkyl and hydroxyl moieties of each adsorbate.These results expand the range of materials in which such functional group resolved relaxation is known to occur,and demonstrate the clear persistence of such phenomena using a range of typical benchtop NMR systems employed to study fluid-saturated porous media. 展开更多
关键词 NMR relaxation ADSORPTION Porous media Low-field NMR
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The dynamic relaxation form finding method aided with advanced recurrent neural network
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作者 Liming Zhao Zhongbo Sun +1 位作者 Keping Liu Jiliang Zhang 《CAAI Transactions on Intelligence Technology》 SCIE EI 2023年第3期635-644,共10页
How to establish a self‐equilibrium configuration is vital for further kinematics and dynamics analyses of tensegrity mechanism.In this study,for investigating tensegrity form‐finding problems,a concise and efficien... How to establish a self‐equilibrium configuration is vital for further kinematics and dynamics analyses of tensegrity mechanism.In this study,for investigating tensegrity form‐finding problems,a concise and efficient dynamic relaxation‐noise tolerant zeroing neural network(DR‐NTZNN)form‐finding algorithm is established through analysing the physical properties of tensegrity structures.In addition,the non‐linear constrained opti-misation problem which transformed from the form‐finding problem is solved by a sequential quadratic programming algorithm.Moreover,the noise may produce in the form‐finding process that includes the round‐off errors which are brought by the approximate matrix and restart point calculating course,disturbance caused by external force and manufacturing error when constructing a tensegrity structure.Hence,for the purpose of suppressing the noise,a noise tolerant zeroing neural network is presented to solve the search direction,which can endow the anti‐noise capability to the form‐finding model and enhance the calculation capability.Besides,the dynamic relaxation method is contributed to seek the nodal coordinates rapidly when the search direction is acquired.The numerical results show the form‐finding model has a huge capability for high‐dimensional free form cable‐strut mechanisms with complicated topology.Eventually,comparing with other existing form‐finding methods,the contrast simulations reveal the excellent anti‐noise performance and calculation capacity of DR‐NTZNN form‐finding algorithm. 展开更多
关键词 dynamic relaxation form‐finding noise‐tolerant zeroing neural network sequential quadratic programming TENSEGRITY
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关于最小二乘拟合的 Succesive over Relaxation渐进迭代逼近
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作者 田沂 杜勇奇 《应用数学进展》 2023年第11期4806-4813,共8页
本文以Guass-Seidel progressive iterative approximation for least squares fitting( LSPLA)算法为基础,提出一种基于 Succesive Over Relaxation(SOR)迭代的 LSPIA算法,简称SOR- LSPIA。我们分析了SOR- LSPIA算法的收敛性,数值实验... 本文以Guass-Seidel progressive iterative approximation for least squares fitting( LSPLA)算法为基础,提出一种基于 Succesive Over Relaxation(SOR)迭代的 LSPIA算法,简称SOR- LSPIA。我们分析了SOR- LSPIA算法的收敛性,数值实验表明,当拟合精度相同时,SOR- LSPIA算法比GS- LSPIA算法送代步数更少、运行时间更短。 展开更多
关键词 渐进迭代逼近 Guass-Seidel迭代法 Succesive Over relaxation迭代法 曲线逼近
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Binary fluids in mesoporous materials: Phase separation studied by NMR relaxation and diffusion
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作者 Siegfried Stapf Niklas Siebert +3 位作者 Timo Spalek Vincent Hartmann Bulat Gizatullin Carlos Mattea 《Magnetic Resonance Letters》 2023年第2期108-117,I0003,共11页
Relaxation and diffusion measurements were carried out on single and binary liquids filling the pore space of controlled porous glass Vycor with an average pore size of about 4 nm.The dispersion of the longitudinal re... Relaxation and diffusion measurements were carried out on single and binary liquids filling the pore space of controlled porous glass Vycor with an average pore size of about 4 nm.The dispersion of the longitudinal relaxation time Tr is discussed as a means to identify liquid-surface interaction based on existing models developed for metal-free glass surfaces.In addition,the change of T1 and T2 with respect to their bulk values is discussed,in particular T2 serves as a probe for the strength of molecular interactions.As the native glass surface is polar and contains a large amount of hydroxyl groups,a pronounced interaction of polar and protic adsorbate liquids is expected;however,the T dispersion,and the corresponding reduction of T2,are also observed for non-polar liquids such as alkanes and cyclohexane.Deuterated liquids are employed for simplifying data analysis in binary systems,but also for separating the respective contributions of intra-and intermolecular interactions to the overall relaxation rate.Despite the lack of paramagnetic impurities in the glass material,H and 2H relaxation dispersions of equivalent molecules are frequently found to differ from each other,suggesting intermolecular relaxation mechanisms for the'H nuclei.The variation of the T dispersion when comparing single and binary systems gives clear evidence for the preferential adsorption of one of the two liquids,suggesting complete phase separation in several cases.Measurement of the apparent tortuosity by self-diffusion experiments supports the concept of a local variation of sample composition within the porespace. 展开更多
关键词 NMR relaxation Fast field cycling Porous media Binary fluids Phase separation
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Prediction of impedance responses of protonic ceramic cells using artificial neural network tuned with the distribution of relaxation times
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作者 Xuhao Liu Zilin Yan +6 位作者 Junwei Wu Jake Huang Yifeng Zheng Neal PSullivan Ryan O'Hayre Zheng Zhong Zehua Pan 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第3期582-588,I0016,共8页
A deep-learning-based framework is proposed to predict the impedance response and underlying electrochemical behavior of the reversible protonic ceramic cell(PCC) across a wide variety of different operating condition... A deep-learning-based framework is proposed to predict the impedance response and underlying electrochemical behavior of the reversible protonic ceramic cell(PCC) across a wide variety of different operating conditions.Electrochemical impedance spectra(EIS) of PCCs were first acquired under a variety of opera ting conditions to provide a dataset containing 36 sets of EIS spectra for the model.An artificial neural network(ANN) was then trained to model the relationship between the cell operating condition and EIS response.Finally,ANN model-predicted EIS spectra were analyzed by the distribution of relaxation times(DRT) and compared to DRT spectra obtained from the experimental EIS data,enabling an assessment of the accumulative errors from the predicted EIS data vs the predicted DRT.We show that in certain cases,although the R^(2)of the predicted EIS curve may be> 0.98,the R^(2)of the predicted DRT may be as low as~0.3.This can lead to an inaccurate ANN prediction of the underlying time-resolved electrochemical response,although the apparent accuracy as evaluated from the EIS prediction may seem acceptable.After adjustment of the parameters of the ANN framework,the average R^(2)of the DRTs derived from the predicted EIS can be improved to 0.9667.Thus,we demonstrate that a properly tuned ANN model can be used as an effective tool to predict not only the EIS,but also the DRT of complex electrochemical systems. 展开更多
关键词 Protonic ceramic fuel cell/electrolysis cell Electrochemical impedance spectroscopy Distribution of relaxation times Artificial neural network
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Modified Exact Jacobian Semidefinite Programming Relaxation for Celis-Dennis-Tapia Problem
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作者 赵馨 孔汕汕 《Journal of Donghua University(English Edition)》 CAS 2023年第1期96-104,共9页
A modified exact Jacobian semidefinite programming(SDP)relaxation method is proposed in this paper to solve the Celis-Dennis-Tapia(CDT)problem using the Jacobian matrix of objective and constraining polynomials.In the... A modified exact Jacobian semidefinite programming(SDP)relaxation method is proposed in this paper to solve the Celis-Dennis-Tapia(CDT)problem using the Jacobian matrix of objective and constraining polynomials.In the modified relaxation problem,the number of introduced constraints and the lowest relaxation order decreases significantly.At the same time,the finite convergence property is guaranteed.In addition,the proposed method can be applied to the quadratically constrained problem with two quadratic constraints.Moreover,the efficiency of the proposed method is verified by numerical experiments. 展开更多
关键词 Celis-Dennis-Tapia(CDT)problem quadratically constrained problem with two quadratic constraints semidefinite programming(SDP)relaxation method
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