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Rising utilization of stable isotopes in tree rings for climate change and forest ecology 被引量:1
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作者 Ru Huang Chenxi Xu +3 位作者 Jussi Grießinger Xiaoyu Feng Haifeng Zhu Achim Bräuning 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第1期103-116,共14页
Analyses of stable isotopes(C,O,H)in tree rings are increasingly important cross-disciplinary programs.The rapid development in this field documented in an increasing number of publications requires a comprehensive re... Analyses of stable isotopes(C,O,H)in tree rings are increasingly important cross-disciplinary programs.The rapid development in this field documented in an increasing number of publications requires a comprehensive review.This study includes a bibliometric analysis-based review to better understand research trends in tree ring stable isotope research.Overall,1475 publications were selected from the Web of Science Core Collection for 1974-2023.The findings are that:(1)numbers of annual publications and citations increased since 1974.From 1974 to 1980,there were around two relevant publications per year.However,from 2020 to 2022,this rose sharply to 109 publications per year.Likewise,average article citations were less than four per year before 1990,but were around four per article per year after 2000;(2)the major subjects using tree ring stable isotopes include forestry,geosciences,and environmental sciences,contributing to 42.5%of the total during 1974-2023;(3)the top three most productive institutions are the Chinese Academy of Sciences(423),the Swiss Federal Institute for Forest,Snow and Landscape Research(227),and the University of Arizona(204).These achievements result from strong collaborations;(4)review papers,for example,(Dawson et al.,Annu Rev Ecol Syst 33:507-559,2002)and(McCarroll and Loader,Quat Sci Rev 23:771-801,2004),are among the most cited,with more than 1000 citations;(5)tree ring stable isotope studies mainly focus on climatology and ecology,with atmospheric CO_(2) one of the most popular topics.Since 2010,precipitation and drought have received increasing attention.Based on this analysis,the research stages,key findings,debated issues,limitations and direc-tions for future research are summarized.This study serves as an important attempt to understand the progress on the use of stable isotopes in tree rings,providing scientific guid-ance for young researchers in this field. 展开更多
关键词 Tree rings Stable isotopes Web of Science BIBLIOMETRIC
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Beyond authorship: Analyzing contributions in PLOS ONE and the challenges of appropriate attribution 被引量:1
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作者 Abdelghani Maddi Jaime A.Teixeira da Silva 《Journal of Data and Information Science》 CSCD 2024年第3期88-115,共28页
Purpose:This study aims to evaluate the accuracy of authorship attributions in scientific publications,focusing on the fairness and precision of individual contributions within academic works.Design/methodology/approa... Purpose:This study aims to evaluate the accuracy of authorship attributions in scientific publications,focusing on the fairness and precision of individual contributions within academic works.Design/methodology/approach:The study analyzes 81,823 publications from the journal PLOS ONE,covering the period from January 2018 to June 2023.It examines the authorship attributions within these publications to try and determine the prevalence of inappropriate authorship.It also investigates the demographic and professional profiles of affected authors,exploring trends and potential factors contributing to inaccuracies in authorship.Findings:Surprisingly,9.14%of articles feature at least one author with inappropriate authorship,affecting over 14,000 individuals(2.56%of the sample).Inappropriate authorship is more concentrated in Asia,Africa,and specific European countries like Italy.Established researchers with significant publication records and those affiliated with companies or nonprofits show higher instances of potential monetary authorship.Research limitations:Our findings are based on contributions as declared by the authors,which implies a degree of trust in their transparency.However,this reliance on self-reporting may introduce biases or inaccuracies into the dataset.Further research could employ additional verification methods to enhance the reliability of the findings.Practical implications:These findings have significant implications for journal publishers,Beyond authorship:Analyzing contributions in PLOS ONE and Maddi,A.,&the challenges of appropriate attribution highlighting the necessity for robust control mechanisms to ensure the integrity of authorship attributions.Moreover,researchers must exercise discernment in determining when to acknowledge a contributor and when to include them in the author list.Addressing these issues is crucial for maintaining the credibility and fairness of academic publications.Originality/value:This study contributes to an understanding of critical issues within academic authorship,shedding light on the prevalence and impact of inappropriate authorship attributions.By calling for a nuanced approach to ensure accurate credit is given where it is due,the study underscores the importance of upholding ethical standards in scholarly publishing. 展开更多
关键词 Authorship Funding acquisition Research integrity Author contributions CREDIT Inappropriate authorship APC ring
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Cover story: Neuromodulation Brings Sunshine to Diseased Brains
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《General Psychiatry》 CSCD 2024年第1期32-32,共1页
Various invasive and non-invasive brain modulation methods are widely used to regulate sensory,cognitive,and motor functions both within local and large brain networks.This special issue provides innovative studies to... Various invasive and non-invasive brain modulation methods are widely used to regulate sensory,cognitive,and motor functions both within local and large brain networks.This special issue provides innovative studies to optimize relevant methods and understand their neural mechanisms,paving the way for personalized neuromodulation of cognitive function.The cover of this issue uses the image of the four heavenly Kings in Chinese culture who are in charge of good weather.It compares the process of neuroregulation technology that integrates the principles of sound,light electricity or magnetism in treating the diseased brain,to the moment when these gods cast their spells to bring sunshine and peace to the human brain in the midst of lightning and thunder. 展开更多
关键词 SUNSHINE LIGHTNING rings
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Beam based alignment using a neural network
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作者 Guan-Liang Wang Ke-Min Chen +5 位作者 Si-Wei Wang Zhe Wang Tao He Masahito Hosaka Guang-Yao Feng Wei Xu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第4期108-118,共11页
Beams typically do not travel through the magnet centers because of errors in storage rings.The beam deviating from the quadrupole centers is affected by additional dipole fields due to magnetic field feed-down.Beam-b... Beams typically do not travel through the magnet centers because of errors in storage rings.The beam deviating from the quadrupole centers is affected by additional dipole fields due to magnetic field feed-down.Beam-based alignment(BBA)is often performed to determine a golden orbit where the beam circulates around the quadrupole center axes.For storage rings with many quadrupoles,the conventional BBA procedure is time-consuming,particularly in the commissioning phase,because of the necessary iterative process.In addition,the conventional BBA method can be affected by strong coupling and the nonlinearity of the storage ring optics.In this study,a novel method based on a neural network was proposed to determine the golden orbit in a much shorter time with reasonable accuracy.This golden orbit can be used directly for operation or adopted as a starting point for conventional BBA.The method was demonstrated in the HLS-II storage ring for the first time through simulations and online experiments.The results of the experiments showed that the golden orbit obtained using this new method was consistent with that obtained using the conventional BBA.The development of this new method and the corresponding experiments are reported in this paper. 展开更多
关键词 Golden orbit Beam-based alignment Neural network Storage ring
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Dynamics of a rotating ring-stiffened sandwich conical shell with an auxetic honeycomb core
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作者 S.JAHANGIRI A.GHORBANPOUR ARANI Z.KHODDAMI MARAGHI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第6期963-982,共20页
The free vibration analysis of a rotating sandwich conical shell with a reentrant auxetic honeycomb core and homogenous isotropic face layers reinforced with a ring support is studied.The shell is modeled utilizing th... The free vibration analysis of a rotating sandwich conical shell with a reentrant auxetic honeycomb core and homogenous isotropic face layers reinforced with a ring support is studied.The shell is modeled utilizing the first-order shear deformation theory(FSDT)incorporating the relative,centripetal,and Coriolis accelerations alongside the initial hoop tension created by the rotation.The governing equations,compatibility conditions,and boundary conditions are attained using Hamilton’s principle.Utilizing trigonometric functions,an analytical solution is derived in the circumferential direction,and a numerical one is presented in the meridional direction via the differential quadrature method(DQM).The effects of various factors on the critical rotational speeds and forward and backward frequencies of the shell are studied.The present work is the first theoretical work regarding the dynamic analysis of a rotating sandwich conical shell with an auxetic honeycomb core strengthened with a ring support. 展开更多
关键词 free vibration conical shell rotating shell ring support auxetic honeycomb
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Effectivity and safety of trifocal intraocular lenses and capsular tension rings implantation for cataract patients with axial high myopia
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作者 Shan Hua Qiu-Xia Xie +1 位作者 Hu Wang Jing-Xiang Zhong 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第3期499-508,共10页
●AIM:To assess effectivity and safety of trifocal intraocular lenses(IOLs)and capsular tension rings in treating cataract patients with axial high myopia.●METHODS:A prospective nonrandomized controlled clinical tria... ●AIM:To assess effectivity and safety of trifocal intraocular lenses(IOLs)and capsular tension rings in treating cataract patients with axial high myopia.●METHODS:A prospective nonrandomized controlled clinical trial was conducted.Totally 98 eyes(74 patients)who underwent femtosecond laser-assisted cataract surgery(FLACS)with trifocal IOLs were enrolled in the study and followed up for 2y after surgery:46 eyes(33 patients)with capsular tension ring implantation in the long axial lengths(AL)group(26<AL<29 mm)and 52 eyes(41 patients)in the normal AL group(22<AL<24.5 mm).Postoperative outcomes about effectivity and safety,including the subjective and objective visual quality,and postoperative complications were assessed.●RESULTS:Uncorrected distance visual acuity at 5 m and uncorrected intermediate visual acuity at 60 and 80 cm in the long AL group were significantly worse than those in the normal AL group at 3mo postoperatively(P<0.05).The differences in reading speed,spectacle independence and potential visual complaints between the two groups were not statistically significant(P>0.05).The dysfunctional lens index and total modulation transfer function(MTF)average height were similar between the two groups.The postoperative internal coma aberrations in the axial high myopia eyes were significantly higher than that in the normal AL group(P<0.05).The total satisfaction score in the long AL group(91.32±2.76)was slightly higher than that in the normal AL group(90.36±3.47),but there was no difference(P=0.136).A statistically negative correlation was found between corrected distance visual acuity(CDVA)and dysfunctional lens index(r=-0.382,P=0.009),and between CDVA and the total MTF average height(r=-0.374,P=0.01).But there was no significant correlation between CDVA and total satisfaction score(r=0.059,P=0.696).Postoperative complications mainly presented as posterior capsular opacity(PCO),retinal detachment and cystoid macular edema.There was no difference in the incidence of fundus disease(6.5%vs 3.8%,P=0.663)or PCO(17.4%vs 7.7%,P=0.217)between the two groups at two years.●CONCLUSION:The utilization of trifocal IOL and capsular tension ring implantation is beneficial for cataract patients with axial high myopia undergoing FLACS.This approach not only ensures excellent subjective feelings and objective visual quality,but also does not increase the incidence of postoperative complications. 展开更多
关键词 trifocal intraocular lenses capsular tension ring axial high myopia CATARACT visual quality
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Wilson's disease in two siblings from Ecuador:Two case reports
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作者 Enrique Carrera Jonathan Alvarado +1 位作者 Martina Astudillo Galo Pillajo 《World Journal of Clinical Cases》 SCIE 2025年第3期50-60,共11页
BACKGROUND Wilson's disease(WD)is a rare metabolic disorder of copper accumulation in organs such as liver,brain,and cornea.Diagnoses and treatments are challenging in settings,where advanced diagnostic tests are ... BACKGROUND Wilson's disease(WD)is a rare metabolic disorder of copper accumulation in organs such as liver,brain,and cornea.Diagnoses and treatments are challenging in settings,where advanced diagnostic tests are unavailable,copper chelating agents are frequently scarce,healthcare professionals lack disease awareness,and medical follow-ups are limited.Prompt diagnoses and treatments help prevent complications,improve patients’quality of life,and ensure a normal life expectancy.The clinical presentations and outcomes of WD can vary within a single family.CASE SUMMARY We present the cases of two siblings(19 and 27 years)from a consanguineous family in rural Ecuador,diagnosed as having WD during a family screening.The male patient,diagnosed at age 19 after his brother’s death from acute liver failure,presented with compensated cirrhosis,neurological symptoms,and bilateral Kayser-Fleischer rings.He developed progressive neurological deterioration during an irregular treatment with D-penicillamine due to medication shortages.His condition improved upon switching to trientine tetrahydrochloride,and his neurological symptoms improved over an 8-year period of follow-ups.The female patient,diagnosed at age 10,exhibited only biochemical alterations.Her treatment history was similar;however,she remained asymptomatic without disease progression over the same follow-up period.We discuss the potential influence of epigenetic mechanisms and modifier genes on the various phenotypes,emphasizing the need for research in these areas to optimize therapeutic strategies.CONCLUSION Our patients’medical histories show how early diagnosis and treatment can prevent disease progression;and,how suboptimal treatments impact disease outcomes. 展开更多
关键词 Wilson disease Kayser-Fleischer rings Copper chelator D-PENICILLAMINE Trientine tetrahydrochloride Case report
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A vector sum analysis method for stability evolution of expansive soil slope considering shear zone damage softening
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作者 Junbiao Yan Lingwei Kong +1 位作者 Cheng Chen Mingwei Guo 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第9期3746-3759,共14页
Slope stability analysis is a classical mechanical problem in geotechnical engineering and engineering geology.It is of great significance to study the stability evolution of expansive soil slopes for engineering cons... Slope stability analysis is a classical mechanical problem in geotechnical engineering and engineering geology.It is of great significance to study the stability evolution of expansive soil slopes for engineering construction in expansive soil areas.Most of the existing studies evaluate the slope stability by analyzing the limit equilibrium state of the slope,and the analysis method for the stability evolution considering the damage softening of the shear zone is lacking.In this study,the large deformation shear mechanical behavior of expansive soil was investigated by ring shear test.The damage softening characteristic of expansive soil in the shear zone was analyzed,and a shear damage model reflecting the damage softening behavior of expansive soil was derived based on the damage theory.Finally,by skillfully combining the vector sum method and the shear damage model,an analysis method for the stability evolution of the expansive soil slope considering the shear zone damage softening was proposed.The results show that the shear zone subjected to large displacement shear deformation exhibits an obvious damage softening phenomenon.The damage variable equation based on the logistic function can be well used to describe the shear damage characteristics of expansive soil,and the proposed shear damage model is in good agreement with the ring shear test results.The vector sum method considering the damage softening behavior of the shear zone can be well applied to analyze the stability evolution characteristics of the expansive soil slope.The stability factor of the expansive soil slope decreases with the increase of shear displacement,showing an obvious progressive failure behavior. 展开更多
关键词 Expansive soil slope Stability analysis Ring shear test Vector sum method Damage model Strain softening
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Developing a novel big dataset and a deep neural network to predict the bearing capacity of a ring footing
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作者 Ramin Vali Esmaeil Alinezhad +3 位作者 Mohammad Fallahi Majid Beygi Mohammad Saberian Jie Li 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第11期4798-4813,共16页
The accurate prediction of the bearing capacity of ring footings,which is crucial for civil engineering projects,has historically posed significant challenges.Previous research in this area has been constrained by con... The accurate prediction of the bearing capacity of ring footings,which is crucial for civil engineering projects,has historically posed significant challenges.Previous research in this area has been constrained by considering only a limited number of parameters or utilizing relatively small datasets.To overcome these limitations,a comprehensive finite element limit analysis(FELA)was conducted to predict the bearing capacity of ring footings.The study considered a range of effective parameters,including clay undrained shear strength,heterogeneity factor of clay,soil friction angle of the sand layer,radius ratio of the ring footing,sand layer thickness,and the interface between the ring footing and the soil.An extensive dataset comprising 80,000 samples was assembled,exceeding the limitations of previous research.The availability of this dataset enabled more robust and statistically significant analyses and predictions of ring footing bearing capacity.In light of the time-intensive nature of gathering a substantial dataset,a customized deep neural network(DNN)was developed specifically to predict the bearing capacity of the dataset rapidly.Both computational and comparative results indicate that the proposed DNN(i.e.DNN-4)can accurately predict the bearing capacity of a soil with an R2 value greater than 0.99 and a mean squared error(MSE)below 0.009 in a fraction of 1 s,reflecting the effectiveness and efficiency of the proposed method. 展开更多
关键词 Bearing capacity Ring footing Finite element limit analysis(FELA) BC-RF dataset Deep neural network(DNN)
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Comparative evaluation of rotational stability of toric IOLs with four-eyelet vs two-eyelet capsular tension rings in eyes with high myopia 被引量:11
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作者 Hui-Min Jiang Kun Liang Li-Ming Tao 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2021年第3期378-382,共5页
AIM:To compare the rotational stability of Toric intraocular lens(IOLs)implantation combined with foureyelet or two-eyelet capsular tension rings(CTRs)in eyes with high myopia and cataract.METHODS:This prospective ran... AIM:To compare the rotational stability of Toric intraocular lens(IOLs)implantation combined with foureyelet or two-eyelet capsular tension rings(CTRs)in eyes with high myopia and cataract.METHODS:This prospective randomized controlled interventional study in cluded 33 eyes which had preoperative corneal astigmatism≥1.5 D and ocular axial length≥25.5 mm.These eyes were randomly divided into two groups to undergo phacoemulsification and toric IOL implantation with either four-eyelet CTR implantation(group A,n=16)or two-eyelet CTR implantation(group B,n=17).Uncorrected visual acuity(UCVA),best-corrected visual acuity(BCVA),phoropter examination results,and toric IOL rotation degrees were tested 6 mo after the surgery.RESULTS:In both groups,the toric IOL was in the capsular sac 6 mo after surgery.The difference between the two groups in terms of visual outcome was not found to be statistically significant(P>0.05)at a follow-up of 6 mo.The mean residual astigmatism values were 0.56±0.22 D and 0.92±0.24 D in A and B groups,respectively(P<0.001).The mean rotation degree of IOL was 1.00°±0.73°in group A and 3.53°±1.46°in group B(P<0.001).CONCLUSION:In cataract patients with high myopia and astigmatism,four-eyelet CTR can effectively increase the rotation stability of toric IOLs,achieving the desired goal of correcting corneal astigmatism. 展开更多
关键词 capsular tension ring toric intraocular lens CATARACT axial myopic astigmatism
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High-temperature nodal ring semimetal in two-dimensional honeycomb-kagome Mn_(2)N_(3) lattice 被引量:1
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作者 Xin-Ke Liu Xin-Yang Li +2 位作者 Miao-Juan Ren Pei-Ji Wang Chang-Wen Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第12期477-483,共7页
The search for two-dimensional(2D)nodal ring semimetallic materials is a current research hotspot in spintronics,and designing a 2D nodal ring(NR)material with high Curie temperature(TC)and strong robustness to spin-o... The search for two-dimensional(2D)nodal ring semimetallic materials is a current research hotspot in spintronics,and designing a 2D nodal ring(NR)material with high Curie temperature(TC)and strong robustness to spin-orbit coupling(SOC)is an even greater challenge.Here,based on the first-principles calculations and symmetry analysis,we predict that 2D Mn_(2)N_(3)is a nodal ring semimetal(NRSM)with three energy bands near the Fermi energy level consisting of electrons in the same spin channel.An electron-like energy band and two hole-like energy bands near the Fermi plane cross to form two NRs centered at the pointΓ.Symmetry analysis shows that the spin-polarized NR semimetal is robust to SOC due to the conservation of horizontal mirror symmetry.Monte-Carlo simulations further demonstrate that the TCof the 2D Mn_(2)N_(3)reaches 530 K,well above the room temperature.Notably,the 2D Mn_(2)N_(3)remains an NRSM on h-BN substrate.Our results not only reveal a general framework for designing 2D NR materials,but also promote further research in the direction of multifunctional quantum devices for spintronics. 展开更多
关键词 first-principles calculation semi-metal nodal ring Curie temperature
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ON THE CHARACTERIZATION OF CYCLIC CODES OVER TWO CLASSES OF RINGS
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作者 刘修生 《Acta Mathematica Scientia》 SCIE CSCD 2013年第2期413-422,共10页
Let R be a finite chain ring with maximal ideal (7) and residue field F,and letγ be of nilpotency index t. To every code C of length n over R, a tower of codes C = (C : γ0) C_ (C: 7) C ... C_ (C: γ2) C_ ... Let R be a finite chain ring with maximal ideal (7) and residue field F,and letγ be of nilpotency index t. To every code C of length n over R, a tower of codes C = (C : γ0) C_ (C: 7) C ... C_ (C: γ2) C_ .-. C_ (C:γ^t-1) can be associated with C, where for any r C R, (C : r) = {e C Rn I re E C}. Using generator elements of the projection of such a tower of codes to the residue field F, we characterize cyclic codes over R. This characterization turns the condition for codes over R to be cyclic into one for codes over the residue field F. Furthermore, we obtain a characterization of cyclic codes over the formal power series ring of a finite chain ring. 展开更多
关键词 Finite chain rings formal power series rings cyclic codes tower of codes Hensel lift
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Coupling between Two NO Radicals Linked through Electron-Rich Rings
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作者 Hai Quan HU1 Xian ZHAO2 +1 位作者 Da Cheng FENG1 Cheng Bu LIU1 (1Institute of Theoretical Chemistry. Shandong University. Jinan 250100 2Institute of Crystal Materials, Shandong University. Jinan 250100) 《Chinese Chemical Letters》 SCIE CAS CSCD 2000年第2期123-126,共4页
The characters of coupling between two doublet NO radicals linked through electron-rich rings have been studied. The results demonstrate that the molecules have triplet ground states, and ferromagnetic coupling exists... The characters of coupling between two doublet NO radicals linked through electron-rich rings have been studied. The results demonstrate that the molecules have triplet ground states, and ferromagnetic coupling exists in these molecules. 展开更多
关键词 electron-rich ring ferromagnetic coupling NO radical
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Analytical Expression of Ampere’s Force Between Two Current Rings in a Compensated Torsion Balance
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作者 LUO Jun FAN Shuhua 《Chinese Physics Letters》 SCIE CAS CSCD 1994年第3期141-144,共4页
An analytical expression of ampere’s force between two current rings in a compensated torsion balance is deduced here,the properties and stability of this force are discussed.The result of numerical estimation for ty... An analytical expression of ampere’s force between two current rings in a compensated torsion balance is deduced here,the properties and stability of this force are discussed.The result of numerical estimation for typical experimental parameters shows that the uncertainties of the force are smaller than 1×10^(-4) orders,which is very important for precise measurement of gravitational constant G. 展开更多
关键词 TORSION PRECISE rings
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Stability of neodymium:YAG laser posterior capsulotomy in eyes with capsular tension rings 被引量:1
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作者 Yang Kyung Cho Min Sun Kim 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第6期891-896,共6页
·AIM: To evaluate the stability of neodymium(Nd):YAG laser posterior capsulotomy in eyes with capsular tension rings(CTRs).·METHODS: A total of 60 eyes that underwent cataract surgery and laser posterior cap... ·AIM: To evaluate the stability of neodymium(Nd):YAG laser posterior capsulotomy in eyes with capsular tension rings(CTRs).·METHODS: A total of 60 eyes that underwent cataract surgery and laser posterior capsulotomy postoperatively were included in this retrospective cohort study. To evaluate the safety and stability of capsulotomy, changes in the size of posterior capsulotomy and anterior chamber depth(ACD) in three groups: the group without CTR, the group with 12 mm CTRs, and the group with 13 mm CTRs, at 1wk, 3, 12, and 15mo after capsulotomy, were compared. ·RESULTS: In the group without CTR and the group with 12 mm CTR, there was no significant change in ACD at every post-laser follow-up. In the group with 13 mm CTR, the ACD change was significant until 3mo after capsulotomy. In all groups, there was a significant increase in the area of capsulotomy between 1wk and 3mo post-laser. Between 3 and 12mo post-laser, only the group with 13 mm CTR showed a significant increase in the area of capsulotomy(P<0.01). ·CONCLUSION: Laser posterior capsulotomy is safe in all three groups. The capsulotomy and ACD become stabilized and have not shown significant changes since 1y postlaser, even with larger CTRs. The maintenance of centrifugal capsular tension can last longer with larger CTRs, and the stability of the capsulotomy site can be reached about 12mo after capsulotomy in pseudophakic eyes with larger CTRs. 展开更多
关键词 Nd:YAG laser CAPSULOTOMY capsular tension ring
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Persistent Current in Two Connected Mesoscopic Rings with Reservoirs
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作者 WEIJian-Hua HONGJongbae 《Communications in Theoretical Physics》 SCIE CAS CSCD 2003年第3期359-364,共6页
The persistent current and transmission of two connected Aharonov-Bohm rings coupled to external leads are solved analytically. The conditions on which we may observe persistent current, zero or perfect transmission a... The persistent current and transmission of two connected Aharonov-Bohm rings coupled to external leads are solved analytically. The conditions on which we may observe persistent current, zero or perfect transmission as well as Fano resonance are studied. 展开更多
关键词 persistent current Aharonov-Bohm effects mesoscopic rings
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Synthesis, Structure and Properties of Two Photochromic Compounds Containing A Pyrazolone-ring 被引量:1
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作者 TANG Xincun JIA Dianzeng +2 位作者 ZHANG Xiaogang XIA Xi ZHOU Zhongyuan 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2000年第2期116-121,共6页
Two photochromic compounds with the pyrazolonering as the photochromic functional structure, 2(1phenyl3methyl4benzoformylpyrazolone5)thiosemicarbazone(PMBPTSC) and 2(1phenyl3methyl4benzoformylpyrazolone5)smethylthiose... Two photochromic compounds with the pyrazolonering as the photochromic functional structure, 2(1phenyl3methyl4benzoformylpyrazolone5)thiosemicarbazone(PMBPTSC) and 2(1phenyl3methyl4benzoformylpyrazolone5)smethylthiosemicarbazone(PMBPMTSC), were synthesized and characterized by elemental analysis, MS, IR spectra, NMR spectra. The crystal structure of the photocolored product of PMBPTSC was determined by single crystal XRD analysis. The results show that the photochromic phenomenon is due to the photoisomerization from enol form to keto form. Their photochromic properties were studied by powderUV reflectance spectra under the irradiation of 200—380 nm light. The firstorder rate constants of the photocoloring reaction were found to be 780×10 -3 s -1 for compound 1A and 103×10 -3 s -1 for compound 2A. 展开更多
关键词 SYNTHESIS Crystal structure Pyrazolone-ring Photochromic compound
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Quantum Rings with Two Deeply Bound Electrons under a Magnetic Field
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作者 SITU Shu-Ping 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第4期733-736,共4页
A model is proposed to study the quantum rings with two deeply bound electrons under a variable magnetic field. The emphasis is placed to clarify the effect of the size (diameter) and the width of the ring on the fr... A model is proposed to study the quantum rings with two deeply bound electrons under a variable magnetic field. The emphasis is placed to clarify the effect of the size (diameter) and the width of the ring on the fractional Aharonov-Bohm oscillation. It was found that the reduction of size will lead to a very strong oscillation in the ground state energy and in the persistent current. The electronic correlation has also been demonstrated by showing the nodal structures of wave functions. 展开更多
关键词 quantum ring fractional Aharonov-Bohm oscillation persistent current
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Decomposition of Jordan automorphism of two-order upper triangular matrix algebra over certain semilocal rings
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作者 王兴涛 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2006年第1期4-5,共2页
Let T(R) be a two-order upper matrix algebra over the semilocal ring R which is determined by R=F×F where F is a field such that CharF=0. In this paper, we prove that any Jordan automorphism of T(R) can be decomp... Let T(R) be a two-order upper matrix algebra over the semilocal ring R which is determined by R=F×F where F is a field such that CharF=0. In this paper, we prove that any Jordan automorphism of T(R) can be decomposed into a product of involutive, inner and diagonal automorphisms. 展开更多
关键词 Jordan automorphism upper triangular matrix algebra semilocal ring
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Study of Radio over Fiber Transmission with a Single Line in Ring Topology for Deployment of MIMO Antenna Access Points in a Cell-less Network
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作者 Mamadou Sarr Dialo Diop +1 位作者 Ndolane Diouf Kharouna Talla 《Journal of Sensor Technology》 2023年第2期13-23,共11页
The massive growth of wireless traffic goes hand in hand with the deployment of advanced radio interfaces as well as network densification. This growth has a direct impact on the radio access architecture, which today... The massive growth of wireless traffic goes hand in hand with the deployment of advanced radio interfaces as well as network densification. This growth has a direct impact on the radio access architecture, which today is moving from centralized to distributed deployments through the use of a large number of access points (APs). This paper verifies the feasibility of deploying multiple APs in series on a single line in a ring topology in a cell-less network. On the one hand, this technique will further improve the communication capacity and flexibility of a Radio-over-Fiber (RoF) based mobile communication system and will reduce its construction cost. And on the other hand, this deployment topology is a solution to achieve a massive cell-free Multiple-Input Multiple-Output (MIMO) architecture and a cost-effective fronthaul solution. First, a passive optical add/drop multiplexer (OADM) is used to extract and add downlink and uplink signals from the remote access points of one kilometer. Then, a deployment model is developed with version 17 Optisystem software. The results obtained showed that the quadrature amplitude modulation (QAM) does not adapt to this multi-carrier transmission to deploy several AP in series on a single line. Thus, the performance degradation increases when the number of APs integrated on the line increases. 展开更多
关键词 ROF Ring Topology MIMO Antennas Cell-less Network
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