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Mapping the landscape of gastric signet ring cell carcinoma:Overcoming hurdles and charting new paths for advancement
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作者 Shu-Yuan Wang Jing-Hang Wang +4 位作者 Run-Kai Chen Zhen Yuan Hao Cui Bo Wei Jian-Xin Cui 《World Journal of Clinical Oncology》 2025年第2期94-109,共16页
BACKGROUND In recent years,the global prevalence of gastric cancer(GC)has witnessed a progressive decrease,accompanied by a step-growth in the incidence of gastric signet ring cell carcinoma(GSRCC).As precision medici... BACKGROUND In recent years,the global prevalence of gastric cancer(GC)has witnessed a progressive decrease,accompanied by a step-growth in the incidence of gastric signet ring cell carcinoma(GSRCC).As precision medicine concepts progress,GSRCC,a distinct sub-type of GC,has drawn considerable attention from researchers.However,there still persist some controversies regarding the associated research findings.AIM To summarize the current obstacles and potential future directions for research on GSRCC.METHODS To begin with,all literature related to GSRCC published from January 1,2004 to December 31,2023 was subjected to bibliometric analysis in this article.Additionally,this paper analyzed the research data using CiteSpace,GraphPad Prism v8.0.2,and VOSviewer,which was obtained from the Web of Science Core Collection database.The analysis results were visually represented.RESULTS This study provided a comprehensive overview of the statistical characteristics of the 995 English articles related to GSRCC,including cited references,authors,journals,countries,institutions,and keywords.The popular keywords and clusters contain"prognosis","survival","expression","histology",and"chemotherapy".CONCLUSION The prognosis,precise definition and classification,as well as chemoresistance of GSRCC,continue to be crucial areas of ongoing research,whose directions are closely tied to advancements in molecular biology research on GSRCC. 展开更多
关键词 Gastric cancer Signet ring cell carcinoma Bibliometric analysis CITESPACE VOSviewer
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深水采油树Spring-Seal密封圈接触模型构建与实验测试
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作者 张红 龙圣均 +1 位作者 冯定 黄熠 《中国安全生产科学技术》 CAS CSCD 北大核心 2024年第8期112-119,共8页
为提高深水采油树在高压、高温、低温等工况下长时间工作的稳定性,对采油树密封圈进行重新设计,提出Spring-Seal密封圈(以下简称S密封圈);基于赫兹接触理论、填料密封接触理论,重新构建S密封圈接触力学模型;建立有限元仿真分析模型,分... 为提高深水采油树在高压、高温、低温等工况下长时间工作的稳定性,对采油树密封圈进行重新设计,提出Spring-Seal密封圈(以下简称S密封圈);基于赫兹接触理论、填料密封接触理论,重新构建S密封圈接触力学模型;建立有限元仿真分析模型,分析不同条件下S密封圈的密封性能,同时验证新建接触模型的合理性;利用实验测试S密封圈的实际密封效果。研究结果表明:S密封圈在高压、高温、低温等工况下能够长时间稳定工作且密封性能良好。研究结果可为S密封圈的接触研究及工程运用提供理论参考。 展开更多
关键词 S密封圈 接触模型 密封性能 实验
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Synthesis of New Chiral C_2-Symmetrical Bis(oxazoline) Compounds 被引量:2
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作者 Chun Hua ZHANG Nian Fa YANG Li Wen YANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第2期125-126,共2页
New chiral C_2-symmetrical bis(oxazoline) compounds bearing one isobutyl-, secbutyl-, benzyl- or isopropyl-substituent at the 4-position have been prepared and characterized.
关键词 SYNTHESIS CHIRAL C_2-symmetrical bis(oxazoline).
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Crystal Structure, DFT and Electrochemical Property of a Novel C3-symmetrical 1,3,5-Tri(9-ethyl-6-nitrocarbazol-3-yl) Benzene
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作者 DONG Jin-Long WEN Bin +3 位作者 WANG Song SONG Zhen REN Jian-Guo ZHAO San-Hu 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2019年第9期1455-1462,共8页
A novel C3-symmetrical molecule, 1,3,5-tri(9-ethyl-6-nitrocarbazol-3-yl) benzene(IV), was synthesized and characterized by 1 H NMR, 13 C NMR and UV-vis spectroscopy, elemental analyses and X-ray single crystal diffrac... A novel C3-symmetrical molecule, 1,3,5-tri(9-ethyl-6-nitrocarbazol-3-yl) benzene(IV), was synthesized and characterized by 1 H NMR, 13 C NMR and UV-vis spectroscopy, elemental analyses and X-ray single crystal diffraction analysis. For this complex: C48 H36 N6 O6, Mr = 792.83, triclinic system, space group P1, a = 11.568(6), b = 13.158(7), c = 17.856(10) ?, α = 95.419(9), β = 107.345(8), γ = 114.682(8)o, V = 2281(2) ?3, Z = 2, Dc = 1.154 g/cm3, λ = 0.71073 ?, F(000) = 828, S = 1.083, R = 0.0836 and wR = 0.1926 for 3304 observed reflections with I > 2ζ(I). The compound possesses good thermal stability with the decomposition temperature(Td) of 265 ℃. The absorption and emission spectra show that the compound can emit blue light in CHCl3, and the quantum yield of compound IV in EtOH was 0.66. Furthermore, the electrochemical properties of compound IV were also studied by cyclic voltammetry(CV) method, and the results correspond to the data of theoretical calculation by the Gaussian 09 software. 展开更多
关键词 C3-symmetrical MOLECULE crystal structure DFT TG analysis electrochemical property
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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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MATRICES OVER A REDUCED RING AS SUMS OF THREE TRIPOTENTS
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作者 HUANG Tao CUI Jian ZENG Yue-di 《数学杂志》 2024年第5期406-412,共7页
In this paper,we study reduced rings in which every element is a sum of three tripotents that commute,and determine the integral domains over which every n£n matrix is a sum of three tripotents.It is proved that ... In this paper,we study reduced rings in which every element is a sum of three tripotents that commute,and determine the integral domains over which every n£n matrix is a sum of three tripotents.It is proved that for an integral domain R,every matrix in M_(n)(R)is a sum of three tripotents if and only if R■Zp with p=2,3,5 or 7. 展开更多
关键词 Tripotent companion matrix reduced ring matrix 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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Climate warming is significantly influenced by rising summer maximum temperatures:insights from tree-ring evidence of the Western Tianshan Mountains,China
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作者 Meng Ren Yu Liu +3 位作者 Qiufang Cai Qiang Li Huiming Song Changfeng Sun 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第5期142-154,共13页
As one of the regions most affected by global climate warming,the Tianshan mountains has experienced several ecological crises,including retreating glaciers and water deficits.Climate warming in these mountains is con... As one of the regions most affected by global climate warming,the Tianshan mountains has experienced several ecological crises,including retreating glaciers and water deficits.Climate warming in these mountains is considered mainly to be caused by increases in minimum temperatures and winter temperatures,while the influence of maximum temperatures is unclear.In this study,a 300-year tree-ring chronology developed from the Western Tianshan Mountains was used to reconstruct the summer(June-August)maximum temperature(Tmax6-8) variations from 1718 to2017.The reconstruction explained 53.1% of the variance in the observed Tmax6-8.Over the past 300 years,the Tmax6-8reconstruction showed clear interannual and decadal variabilities.There was a significant warming trend(0.18 ℃/decade) after the 1950s,which was close to the increasing rates of the minimum and mean temperatures.The increase in maximum temperature was also present over the whole Tianshan mountains and its impact on climate warming has increased.The Tmax6-8variations in the Western Tianshan mountains were influenced by frequent volcanic eruptions combined with the influence of solar activity and the summer North Atlantic Oscillation.This study reveals that climate warming is significantly influenced by the increase in maximum temperatures and clarifies possible driving mechanisms of temperature variations in the Western Tianshan mountains which should aid climate predictions. 展开更多
关键词 Tree rings Western Tianshan mountains Temperature change Climate warming
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Analysis and optimization of stamping and forming process of bearing outer ring
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作者 Shichao Zhu Yulu Ding +4 位作者 Bing Long Hun Guo Linhan Ouyang Wengang Chen Zhengyi Jiang 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2024年第3期227-237,共11页
To address the common issues of wrinkling,tearing,and uneven wall thickness in the actual sheet metal stamp-ing process of the outer ring of needle roller bearings,this study analyzes critical technical indicators suc... To address the common issues of wrinkling,tearing,and uneven wall thickness in the actual sheet metal stamp-ing process of the outer ring of needle roller bearings,this study analyzes critical technical indicators such asforming limits,thickness distribution,and principal strains in the forming process in detail.Three-dimensionalmodels of the concave and convex dies were constructed.The effects of different process parameters,includingstamping speed,edge pressure,sheet metal thickness,and friction coefficient,on the quality of the forming partswere investigated by varying these parameters.Subsequently,the orthogonal experimental method was used todetermine an optimal experimental group from multiple sets of experiments.It was found that under the processparameters of a stamping speed of 3000 mm/s,edge pressure of 2000 N,sheet metal thickness of 0.9 mm,andfriction coefficient of 0.125,the forming quality of the outer ring of the bearing is ideal. 展开更多
关键词 Plate stamping Bearing outer ring Mold design OPTIMIZATION
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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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Climate warming is significantly influenced by rising summer maximum temperatures: insights from tree-ring evidence of the Western Tianshan Mountains, China
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作者 Meng Ren Yu Liu +3 位作者 Qiufang Cai Qiang Li Huiming Song Changfeng Sun 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第4期47-59,共13页
As one of the regions most affected by global cli-mate warming,the Tianshan mountains has experienced sev-eral ecological crises,including retreating glaciers and water deficits.Climate warming in these mountains is c... As one of the regions most affected by global cli-mate warming,the Tianshan mountains has experienced sev-eral ecological crises,including retreating glaciers and water deficits.Climate warming in these mountains is considered mainly to be caused by increases in minimum temperatures and winter temperatures,while the influence of maximum temperatures is unclear.In this study,a 300-year tree-ring chronology developed from the Western Tianshan Moun-tains was used to reconstruct the summer(June-August)maximum temperature(T_(max6-8))variations from 1718 to 2017.The reconstruction explained 53.1% of the variance in the observed T_(max6-8).Over the past 300 years,the T_(max6-8)reconstruction showed clear interannual and decadal vari-abilities.There was a significant warming trend(0.18°C/decade)after the 1950s,which was close to the increasing rates of the minimum and mean temperatures.The increase in maximum temperature was also present over the whole Tianshan mountains and its impact on climate warming has increased.The T_(max6-8) variations in the Western Tianshan mountains were influenced by frequent volcanic eruptions combined with the influence of solar activity and the sum-mer North Atlantic Oscillation.This study reveals that cli-mate warming is significantly influenced by the increase in maximum temperatures and clarifies possible driving mech-anisms of temperature variations in the Western Tianshan mountains which should aid climate predictions. 展开更多
关键词 Tree rings Western Tianshan mountains Temperature change Climate warming
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Double intrastromal corneal ring segment implantation: a new approach for improved clinical outcomes in keratoconus patients
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作者 Sandro Coscarelli Reinaldo de Oliveira Sieiro +2 位作者 Victoria Moreira Fernandes Sandro P.Coscarelli Leonardo Torquetti 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第11期2023-2030,共8页
AIM:To evaluate the clinical outcomes after subsequent implantation of a new intrastromal corneal ring segment(ICRS)model followed by an additional short-arc ICRS implant in keratoconus patients.METHODS:This retrospec... AIM:To evaluate the clinical outcomes after subsequent implantation of a new intrastromal corneal ring segment(ICRS)model followed by an additional short-arc ICRS implant in keratoconus patients.METHODS:This retrospective single-arm cohort study evaluated 25 eyes of 21 keratoconus patients implanted with the new ICRS followed by 140-arch length ICRS(140-ICRS)implantation.Uncorrected distance visual acuity(UDVA,logMAR),corrected distance visual acuity(CDVA,logMAR),sphere,astigmatism,keratometry,spherical equivalent(SE),and asphericity were compared preoperatively and postoperatively after both ICRS implantation.RESULTS:The average follow-up time after 140-ICRS implantation was 6.40±2.20mo.The mean preoperative UDVA improved from 1.27±0.14 preoperative to 0.52±0.26 after both ICRS implantation(P=0.03).The mean sphere value reduced from-5.34±2.74 preoperatively to-2.06±1.84 postoperatively(P<0.001)after the first ICRS implantation and decreased to-0.59±1.54 postoperatively(P<0.001)after 140-ICRS implantation.The mean preoperative astigmatism was-3.72±1.56 and improved to-2.82±1.08 after the first ICRS implantation,and following the 140-ICRS implantation,the mean astigmatism was-1.37±0.67(P=0.001).The SE and asphericity changes were statistically significant(P<0.001).The researchers did not find intraoperative or postoperative complications for both procedures.CONCLUSION:The combination of 2 different ICRSs can efficiently regularize the cornea,reduce the SE,and improve visual acuity in selected keratoconus patients. 展开更多
关键词 KERATOCONUS CORNEA intrastromal corneal ring segments refractive surgery
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Winter-spring minimum temperature variations inferred from tree-ring δ^(13)C in southeastern China
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作者 Wenli Li Feifei Zhou +1 位作者 Heng Zhang Keyan Fang 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第5期182-190,共9页
Long-term temperature variations inferred from high-resolution proxies provide an important context to evaluate the intensity of current warming.However,tem-perature reconstructions in humid southeastern China are sca... Long-term temperature variations inferred from high-resolution proxies provide an important context to evaluate the intensity of current warming.However,tem-perature reconstructions in humid southeastern China are scarce and particularly lack long-term data,limiting us to obtain a complete picture of regional temperature evolution.In this study,we present a well-verified reconstruction of winter-spring(January–April)minimum temperatures over southeastern China based on stable carbon isotopic(δ^(13)C)records of tree rings from Taxus wallichiana var.mairei from 1860 to 2014.This reconstruction accounted for 56.4%of the total observed variance.Cold periods occurred during the 1860s–1910s and 1960s–1970s.Although temperatures have had an upward trend since the 1920s,most of the cold extremes were in recent decades.The El Niño-Southern Oscillation(ENSO)variance acted as a key modulator of regional winter-spring minimum temperature variability.However,teleconnections between them were a nonlinear process,i.e.,a reduced or enhanced ENSO variance may result in a weakened or intensified temperature-ENSO relationship. 展开更多
关键词 Tree rings Carbon isotope Southeastern China Extreme coldness El nino-southern oscillation
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Dynamics of perinuclear actin ring regulating nuclear morphology
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作者 Haoxiang YANG Houbo SUN +2 位作者 Jinghao SHEN Hao WU Hongyuan JIANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第8期1415-1428,共14页
Cells are capable of sensing and responding to the extracellular mechanical microenvironment via the actin skeleton.In vivo,tissues are frequently subject to mechanical forces,such as the rapid and significant shear f... Cells are capable of sensing and responding to the extracellular mechanical microenvironment via the actin skeleton.In vivo,tissues are frequently subject to mechanical forces,such as the rapid and significant shear flow encountered by vascular endothelial cells.However,the investigations about the transient response of intracellular actin networks under these intense external mechanical forces,their intrinsic mechanisms,and potential implications are very limited.Here,we observe that when cells are subject to the shear flow,an actin ring structure could be rapidly assembled at the periphery of the nucleus.To gain insights into the mechanism underlying this perinuclear actin ring assembly,we develop a computational model of actin dynamics.We demonstrate that this perinuclear actin ring assembly is triggered by the depolymerization of cortical actin,Arp2/3-dependent actin filament polymerization,and myosin-mediated actin network contraction.Furthermore,we discover that the compressive stress generated by the perinuclear actin ring could lead to a reduction in the nuclear spreading area,an increase in the nuclear height,and a decrease in the nuclear volume.The present model thus explains the mechanism of the perinuclear actin ring assembly under external mechanical forces and suggests that the spontaneous contraction of this actin structure can significantly impact nuclear morphology. 展开更多
关键词 mechanical force actin dynamics perinuclear actin ring compressive stress NUCLEUS
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Stability assessment of tree ring growth of Pinus armandii Franch in response to climate change based on slope directions at the Lubanling in the Funiu Mountains,China
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作者 Jinkuan Li Jianfeng Peng +4 位作者 Xiaoxu Wei Meng Peng Xuan Li Yameng Liu Jiaxin Li 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第3期87-98,共12页
Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and ... Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and tree-ring chronologies developed on northern and western slopes from the Lubanling in the Funiu Mountains.Correlation analyses showed that two chronologies were mainly limited by temperatures in the previous June-August and the com-bination of temperatures and moisture in the current May-July.The difference of the climate response to slopes was small but not negligible.Radial growth of the LBLO1 site on the northern slope was affected by the combined maximum and minimum temperatures,while that of the LBLO2 site was affected by maximum temperatures.With regards to moisture,radial growth of the trees on the north slope was influenced by the relative humidity in the current May-July,while on the western slope,it was affected by the relative humidity in the previous June-August,the current May-July and the precipitation in the current May-July.With the change in climate,the effects of the main limiting factors on growth on different slopes were visible to a certain extent,but the differences in response of trees on different slopes gradually decreased,which might be caused by factors such as different slope directions and the change in diurnal temperature range.These results may provide information for forest protection and ecological construction in this region,and a scientific reference for future climate reconstruction. 展开更多
关键词 Tree ring width Lubanling Pinus armandi Franch Slope direction Climate response
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Stability assessment of tree ring growth of Pinus armandii Franch in response to climate change based on slope directions at the Lubanling in the Funiu Mountains,China
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作者 Jinkuan Li Jianfeng Peng +4 位作者 Xiaoxu Wei Meng Peng Xuan Li Yameng Liu Jiaxin Li 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第2期197-208,共12页
Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and ... Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and treering chronologies developed on northern and western slopes from the Lubanling in the Funiu Mountains.Correlation analyses showed that two chronologies were mainly limited by temperatures in the previous June–August and the combination of temperatures and moisture in the current May–July.The difference of the climate response to slopes was small but not negligible.Radial growth of the LBL01 site on the northern slope was affected by the combined maximum and minimum temperatures,while that of the LBL02 site was affected by maximum temperatures.With regards to moisture,radial growth of the trees on the north slope was influenced by the relative humidity in the current May–July,while on the western slope,it was affected by the relative humidity in the previous June–August,the current May–July and the precipitation in the current May–July.With the change in climate,the effects of the main limiting factors on growth on different slopes were visible to a certain extent,but the differences in response of trees on different slopes gradually decreased,which might be caused by factors such as different slope directions and the change in diurnal temperature range.These results may provide information for forest protection and ecological construction in this region,and a scientific reference for future climate reconstruction. 展开更多
关键词 Tree ring width Lubanling Pinus armandii Franch Slope direction Climate response
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The Construction and Analysis of Linear Ring Spaces
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作者 Daniel A. Jaffa 《Advances in Pure Mathematics》 2024年第9期759-767,共9页
This paper proposes the novel algebraic structure of a linear ring space. A linear ring space is an order triad consisting of two rings, and a linear map between the two rings. The definition of quasi-linearity is dis... This paper proposes the novel algebraic structure of a linear ring space. A linear ring space is an order triad consisting of two rings, and a linear map between the two rings. The definition of quasi-linearity is discussed, in addition to the examination of properties and classifications of linear ring spaces. Particularly, the ring of holomorphic functions on a region of the complex plane is examined, and the manner in which it generates an iterated linear ring space under the complex derivative operator. This notion is then generalized to all rings with nth order linear and surjective operators. Basic operator theory regarding the classifications of linear ring maps is also covered. 展开更多
关键词 ring Theory Group Theory Commutative Algebra Operator Theory Holomorphic Functions
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Annual growth of Fagus orientalis is limited by spring drought conditions in Iran’s Golestan Province
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作者 Khalil Ghorbani Jahangir Mohammadi Laleh Rezaei Ghaleh 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第1期128-142,共15页
Due to the lack of a uniform and accurate defi-nition of‘drought’,several indicators have been introduced based on different variables and methods,and the efficiency of each of these is determined according to their... Due to the lack of a uniform and accurate defi-nition of‘drought’,several indicators have been introduced based on different variables and methods,and the efficiency of each of these is determined according to their relationship with drought.The relationship between two drought indices,SPI(standardized precipitation index)and SPEI(standard-ized precipitation-evapotranspiration index)in different sea-sons was investigated using annual rings of 15 tree samples to determine the effect of drought on the growth of oriental beech(Fagus orientalis Lipsky)in the Hyrcanian forests of northern Iran.The different evapotranspiration calcula-tion methods were evaluated on SPEI efficiency based on Hargreaves-Samani,Thornthwaite,and Penman-Monteith methods using the step-by-step M5 decision tree regression method.The results show that SPEI based on the Penman-Monteith in a three-month time scale(spring)had similar temporal changes and a better relationship with annual tree rings(R^(2)=0.81)at a 0.05 significant level.Abrupt change and a decreasing trend in the time series of annual tree rings are similar to the variation in the SPEI based on the Penman-Monteith method.Factors affecting evapotranspiration,temperature,wind speed,and sunshine hours(used in the Penman-Monteith method),increased but precipitation decreased.Using non-linear modeling methods,SPEI based on Penman-Monteith best illustrated climate changes affecting tree growth. 展开更多
关键词 Climate change Drought index Hyrcanian forests SPEI'Annual growth rings Fagus orientalis
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Novel Assessment Technique: Ring Gauge Measurement of Finger Joint Circumference Changes in Patients with Rheumatoid Arthritis
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作者 Kan Imai Daisaku Tokunaga +6 位作者 Satoru Nakamura Shogo Toyama Naoki Okubo Takahiro Seno Yutaka Kawahito Kenji A. Takahashi Ryo Oda 《Open Journal of Rheumatology and Autoimmune Diseases》 2024年第4期190-200,共11页
Objectives: As therapeutic modalities for rheumatoid arthritis (RA) advance, immediate and quantitative determination of RA disease status is becoming increasingly important. The purpose of this study was to validate ... Objectives: As therapeutic modalities for rheumatoid arthritis (RA) advance, immediate and quantitative determination of RA disease status is becoming increasingly important. The purpose of this study was to validate the usefulness of a ring gauge as a simple semiquantitative method for assessing hand swelling in patients with RA. Methods: We enrolled patients diagnosed with RA either initiated or switched to a biological therapeutic agent. The circumference of the interphalangeal (IP) joint and the proximal interphalangeal (PIP) joint was measured using a ring gauge. Assessments of the joint echocardiography, incorporating both Gray Scale (GS) and Power Doppler (PD) imaging, were conducted. These evaluations were performed both before the initiation of biological agent treatment and 28 days after the initial dose. Results: Following the treatment intervention, a significant reduction was observed in the circumference of the joint from the thumb to the little finger (p Conclusions: Our study demonstrated the effectiveness of using a ring gauge as a simple assessment tool for RA, revealing that a change in the ring gauge number by 2 or more corresponded to either improvement or deterioration in synovial thickening detected via joint echocardiography. 展开更多
关键词 Disease Activity Interphalangeal Joint Rheumatoid Arthritis ring Gauge Semi-Quantitative Evaluation
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Lateral ring compression test applied to a small caliber steel jacket:Identification of a constitutive model
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作者 Yann Coget Yael Demarty +3 位作者 Christophe Czarnota Anthony Bracq Jean-Sebastien Brest Alexis Rusinek 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第6期133-148,共16页
The evolution of threats and scenarios requires continuous performance improvements of ballistic protections for armed forces.From a modeling point of view,it is necessary to use sufficiently precise material behavior... The evolution of threats and scenarios requires continuous performance improvements of ballistic protections for armed forces.From a modeling point of view,it is necessary to use sufficiently precise material behavior models to accurately describe the phenomena observed during the impact of a projectile on a protective equipment.In this context,the goal of this paper is to characterize the behavior of a small caliber steel jacket by combining experimental and numerical approaches.The experimental method is based on the lateral compression of ring specimens directly machined from the thin and small ammunition.Various speeds and temperatures are considered in a quasi-static regime in order to reveal the strain rate and temperature dependencies of the tested material.The Finite Element Updating Method(FEMU)is used.Experimental results are coupled with an inverse optimization method and a finite element numerical model in order to determine the parameters of a constitutive model representative of the jacket material.Predictions of the present model are verified against experimental results and a parametric study as well as a discussion on the identified material parameters are proposed.The results indicate that the strain hardening parameter can be neglected and the behavior of the thin steel jacket can be described by a modeling without strain hardening sensitivity. 展开更多
关键词 Full metal jacket ammunition Lateral ring compression Inverse identification Numerical simulation
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