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Reflexivization and Reciprocality in the Kalabari Language
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作者 Jackrich Oribomate Sopuruchi Christian Aboh 《宏观语言学》 2021年第1期126-133,共8页
This paper examines reflexivization and reciprocality in Kalabari with particular attention to the forms,functions and structures of reflexive and reciprocal constructions(the nominal sub-type)in the language.The pape... This paper examines reflexivization and reciprocality in Kalabari with particular attention to the forms,functions and structures of reflexive and reciprocal constructions(the nominal sub-type)in the language.The paper adopts the binding theory as a framework in analysing the data.The data were gathered through interaction and introspection.The findings reveal that reflexives and reciprocals in Kalabari require a compatible clause-mate antecedent due to the strong anaphoric relationship between reflexive and reciprocal markers and their antecedents respectively.The findings further reveal that the form of Kalabari reflexives consists of-ḇù(-self)and the appropriate form of the pronoun in the language.The paper also reveals that the Kalabari language makes a tripartite distinction for number,person and gender,and the form of the reflexive does not change;only the pronoun changes,while reciprocals consist of a reduplicated form jụmọjụmọ,jápụjápụand jéin jéin.In terms of the structure,findings reveal that reflexives and reciprocals come before the verb of the clause in which they occur.The finding further reveals that reflexives in the language perform both non-emphatic and emphatic functions,while reciprocal relates to human and non-human reference of mutuality.Tonal inflection also makes a distinction in 1st person singular and 2nd person singular reflexives.It is therefore recommended that more studies be done to ascertain the form,function and structure of the verbal and possessive sub-type of reflexive and reciprocal constructions in the language. 展开更多
关键词 REFLEXIVES reciprocals BINDING Kalabari Universal Grammar
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Nonreciprocal Photon Blockade Based on Zeeman Splittings Induced by a Fictitious Magnetic Field
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作者 苏欣 金飚兵 +1 位作者 唐江山 夏可宇 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第7期36-46,共11页
Quantum nonreciprocity, such as nonreciprocal photon blockade, has attracted a great deal of attention due to its unique applications in quantum information processing. Its implementation primarily relies on rotating ... Quantum nonreciprocity, such as nonreciprocal photon blockade, has attracted a great deal of attention due to its unique applications in quantum information processing. Its implementation primarily relies on rotating nonlinear systems, based on the Sagnac effect. Here, we propose an all-optical approach to achieve nonreciprocal photon blockade in an on-chip microring resonator coupled to a V-type Rb atom, which arises from the Zeeman splittings of the atomic hyperfine sublevels induced by the fictitious magnetic field of a circularly polarized control laser. The system manifests single-photon blockade or multi-photon tunneling when driven from opposite directions. This nonreciprocity results from the directional detunings between the countercirculating probe fields and the V-type atom, which does not require the mechanical rotation and facilitates integration. Our work opens up a new route to achieve on-chip integrable quantum nonreciprocity, enabling applications in chiral quantum technologies. 展开更多
关键词 EFFECT reciprocal QUANTUM
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Magnetic Nonreciprocity in a Hybrid Device of Asymmetric Artificial Spin-Ice-Superconductors
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作者 李冲 黄培源 +15 位作者 王晨光 李浩杰 吕阳阳 岳文诚 袁子雄 李甜雨 涂学凑 陶涛 董思宁 何亮 贾小氢 孙国柱 康琳 王华兵 吴培亨 王永磊 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第6期119-127,共9页
Controlling the size and distribution of potential barriers within a medium of interacting particles can unveil unique collective behaviors and innovative functionalities.We introduce a unique superconducting hybrid d... Controlling the size and distribution of potential barriers within a medium of interacting particles can unveil unique collective behaviors and innovative functionalities.We introduce a unique superconducting hybrid device using a novel artificial spin ice structure composed of asymmetric nanomagnets.This structure forms a distinctive superconducting pinning potential that steers unconventional motion of superconducting vortices,thereby inducing a magnetic nonreciprocal effect,in contrast to the electric nonreciprocal effect commonly observed in superconducting diodes.Furthermore,the polarity of the magnetic nonreciprocity is in situ reversible through the tunable magnetic patterns of artificial spin ice.Our findings demonstrate that artificial spin ice not only precisely modulates superconducting characteristics but also opens the door to novel functionalities,offering a groundbreaking paradigm for superconducting electronics. 展开更多
关键词 artificial COLLECTIVE reciprocal
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An analogical study of wave equations,physical quantities,conservation and reciprocity equations between electromagnetic and elastic waves
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作者 Yuchen Zang 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第11期296-304,共9页
This paper presents an analogical study between electromagnetic and elastic wave fields,with a one-to-one correspondence principle established regarding the basic wave equations,the physical quantities and the differe... This paper presents an analogical study between electromagnetic and elastic wave fields,with a one-to-one correspondence principle established regarding the basic wave equations,the physical quantities and the differential operations.Using the electromagnetic-to-elastic substitution,the analogous relations of the conservation laws of energy and momentum are investigated between these two physical fields.Moreover,the energy-based and momentum-based reciprocity theorems for an elastic wave are also derived in the time-harmonic state,which describe the interaction between two elastic wave systems from the perspectives of energy and momentum,respectively.The theoretical results obtained in this analysis can not only improve our understanding of the similarities of these two linear systems,but also find potential applications in relevant fields such as medical imaging,non-destructive evaluation,acoustic microscopy,seismology and exploratory geophysics. 展开更多
关键词 analogical study electromagnetic waves elastic waves wave equations physical quantities conservation laws reciprocity theorems
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Optimal interval for delayed retrieval surgery with reciprocating morcellators after enucleation of giant prostatic hyperplasia in holmium laser enucleation of the prostate
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作者 Fumiyasu Endo Masaki Shimbo +2 位作者 Kenji Komatsu Kazuhiro Ohwaki Kazunori Hattori 《Asian Journal of Urology》 CSCD 2024年第3期423-428,共6页
Objective:The aim of this research was to evaluate the efficiency of reciprocating morcellation for removing giant benign prostatic hyperplasia during holmium laser enucleation of the prostate,investigate whether perf... Objective:The aim of this research was to evaluate the efficiency of reciprocating morcellation for removing giant benign prostatic hyperplasia during holmium laser enucleation of the prostate,investigate whether performing morcellation as a two-stage procedure improves tissue retrieval efficiency,and seek to determine the optimal interval between the two surgeries.Methods:This study included nine cases of holmium laser enucleation of the prostate with an enucleated prostate weight exceeding 200 g,indicative of substantial prostate enlargement.Morcellation was performed on Day 0(n=4),Day 4(n=1),Day 6(n=1),and Day 7(n=3).The intervals were compared regarding the morcellation efficiency,beach ball presence,and pathology.Results:The mean estimated prostate volume was 383(range 330e528)mL;the median enucleation weight was 252(interquartile range[IQR]222,342)g;and the median enucleation time was 83(IQR 62,100)min.The mean morcellation efficiency was 1.44(SD 0.55)g/min on Day 0 and 13.69(SD 2.46)g/min on day 7.The morcellation efficiency was 4.15 g/min and 10.50 g/min on Day 4 and Day 6,respectively,with significantly higher in the two-stage group compared to one-stage group(11.0 g/min vs.1.5 g/min;p=0.014).Efficiency was strongly correlated with intervals(p<0.001);the incidences of beach balls were 100%(4/4)and 60%(3/5)in the immediate and two-stage surgery groups,respectively.Conclusion:The efficiency of two-stage morcellation with reciprocating morcellators was highly related to the postoperative interval,with the maximum efficiency reached on Day 7. 展开更多
关键词 Holmium laser enucleation of the prostate reciprocating morcellator Giant adenoma Two-stage surgery
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Bidirectional rotating direct-current triboelectric nanogenerator with self-adaptive mechanical switching for harvesting reciprocating motion
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作者 Donghan Lee Joonmin Chae +6 位作者 Sumin Cho Jong Woo Kim Awais Ahmad Mohammad Rezaul Karim Moonwoo La Sung Jea Park Dongwhi Choi 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第4期324-335,共12页
Amid the growing interest in triboelectric nanogenerators(TENGs)as novel energy-harvesting devices,several studies have focused on direct current(DC)TENGs to generate a stable DC output for operating electronic device... Amid the growing interest in triboelectric nanogenerators(TENGs)as novel energy-harvesting devices,several studies have focused on direct current(DC)TENGs to generate a stable DC output for operating electronic devices.However,owing to the working mechanisms of conventional DC TENGs,generating a stable DC output from reciprocating motion remains a challenge.Accordingly,we propose a bidirectional rotating DC TENG(BiR-TENG),which can generate DC outputs,regardless of the direction of rotation,from reciprocating motions.The distinct design of the BiR-TENG enables the mechanical rectification of the alternating current output into a rotational-direction-dependent DC output.Furthermore,it allows the conversion of the rotational-direction-dependent DC output into a unidirectional DC output by adapting the configurations depending on the rotational direction.Owing to these tailored design strategies and subsequent optimizations,the BiR-TENG could generate an effective unidirectional DC output.Applications of the BiR-TENG for the reciprocating motions of swinging doors and waves were demonstrated by harnessing this output.This study demonstrates the potential of the BiR-TENG design strategy as an effective and versatile solution for energy harvesting from reciprocating motions,highlighting the suitability of DC outputs as an energy source for electronic devices. 展开更多
关键词 direct-current triboelectric nanogenerator mechanical rectification self-adaptive mechanical design harvesting reciprocation motion
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Reciprocal Distance Laplacian Eigenvalue Distribution Based on Graph Parameters
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作者 CUI Jiaxin MA Xiaoling 《新疆大学学报(自然科学版中英文)》 CAS 2024年第5期562-570,共9页
Let G be a connected graph of order n and m_(RD)^(L)_(G)I denote the number of reciprocal distance Laplacian eigenvaluesof G in an interval I.For a given interval I,we mainly present several bounds on m_(RD)^(L)_(G)I ... Let G be a connected graph of order n and m_(RD)^(L)_(G)I denote the number of reciprocal distance Laplacian eigenvaluesof G in an interval I.For a given interval I,we mainly present several bounds on m_(RD)^(L)_(G)I in terms of various structuralparameters of the graph G,including vertex-connectivity,independence number and pendant vertices. 展开更多
关键词 reciprocal distance Laplacian eigenvalue VERTEX-CONNECTIVITY independence number pendant vertices
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Reciprocity Relation between Alternative Gravity Formulas
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作者 Hans Hermann Otto 《Journal of Applied Mathematics and Physics》 2024年第4期1432-1440,共9页
We compare Newton’s force law of universal gravitation with a corrected simple approach based on Bhandari’s recently presented work, where the gravitation constant G is maintained. A reciprocity relation exists betw... We compare Newton’s force law of universal gravitation with a corrected simple approach based on Bhandari’s recently presented work, where the gravitation constant G is maintained. A reciprocity relation exists between both alternative gravity formulas with respect to the distances between mass centers. We conclude a one-to-one mapping of the two gravitational formulas. We don’t need Einstein’s construct of spacetime bending by matter. 展开更多
关键词 Gravity Formulas reciprocity Distance Relation NEWTON EINSTEIN Bhandari Higgs Field Dirac’s Large Number
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机用ProTaper和Reciproc对弯曲根管成形能力的对比研究 被引量:3
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作者 郭田 郭嘉 +1 位作者 史婷 刘进 《牙体牙髓牙周病学杂志》 CAS 2016年第7期431-434,共4页
目的:比较机用Pro Taper(PT)和Reciproc(RE)两种镍钛根管预备系统对弯曲根管的成形能力。方法:选择20个离体下颌第一磨牙,随机分为2组(n=10),分别用PT和RE进行根管预备并记录预备时间;在根管预备前后分别进行Micro-CT扫描,并利用Fitme D... 目的:比较机用Pro Taper(PT)和Reciproc(RE)两种镍钛根管预备系统对弯曲根管的成形能力。方法:选择20个离体下颌第一磨牙,随机分为2组(n=10),分别用PT和RE进行根管预备并记录预备时间;在根管预备前后分别进行Micro-CT扫描,并利用Fitme DICOM Viewer软件进行根管三维重建和分析,比较2种器械对弯曲根管的形能力。结果:三维重建图像显示,根管预备前后弯曲度的改变量PT组大于RE组(P<0.05);两组根管体积和表面积的改变量在根上部和根中部差异无统计学意义(P>0.05),而在根尖部PT组大于RE组(P<0.05);根管预备时间PT组长于RE组(P<0.05)。结论:单支锉根管预备系统Reciproc在预备效率及中心定位能力,尤其在根尖1/3部,优于机用Pro Taper。 展开更多
关键词 reciproc PROTAPER 根管成形能力 MICRO-CT
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TFA、Reciproc及ProTaper Next根管预备系统的清洁能力及根尖推出物量的比较 被引量:5
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作者 丁群 李振英 +2 位作者 郑晶 王安 叶帼嫔 《牙体牙髓牙周病学杂志》 CAS 2017年第12期698-701,724,共5页
目的:评价3种新型镍钛根管预备系统TFA、Reciproc及ProTaper Next的根管清洁能力及根尖推出量的差异。方法:将40个人类单根管前磨牙随机分为4组(n=10),分别用K锉(A组)、TFA(B组)、Reciproc(C组)和ProTaper Next(D组)进行根管预备后,用... 目的:评价3种新型镍钛根管预备系统TFA、Reciproc及ProTaper Next的根管清洁能力及根尖推出量的差异。方法:将40个人类单根管前磨牙随机分为4组(n=10),分别用K锉(A组)、TFA(B组)、Reciproc(C组)和ProTaper Next(D组)进行根管预备后,用扫描电镜(SEM)对各组根管壁表面的碎屑及玷污层进行评估。然后再将40个树脂根管模型随机分为4组(n=10),分别采用上述4种预备系统进行根管预备,在预备过程中收集其根尖推出物,分别称量,用Ahmad评估标准比较各组推出碎屑及冲洗液的量。结果:各组根管壁的碎屑及玷污层评分由高到低依次为:A组>D组>C组>B组(组间两两相比P<0.05);各组推出根尖的碎屑及冲洗液的量由高到低依次为:K锉组>Reciproc组>ProTaper Next组>TFA组(组间两两相比P<0.05)。结论:TFA、Reciproc及ProTaper Next 3种镍钛预备系统的根管清洁力均优于K锉,TFA效果最佳。 展开更多
关键词 TFA reciproc PROTAPER NEXT 清洁能力 根尖推出物
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Reciproc单支锉预备磨牙弯曲根管疗效观察 被引量:4
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作者 郅洁云 王芳 《口腔医学》 CAS 2016年第7期621-623,共3页
目的:评价往复运动式Reciproc单支锉预备磨牙弯曲根管,保持原根管解剖走向的能力。方法选择年龄18~59岁牙髓病初诊病例,按 Schneider 测量法,第一磨牙弯曲根管(20°~30°)100例,200个根管(颊,舌弯曲根管),随机分为... 目的:评价往复运动式Reciproc单支锉预备磨牙弯曲根管,保持原根管解剖走向的能力。方法选择年龄18~59岁牙髓病初诊病例,按 Schneider 测量法,第一磨牙弯曲根管(20°~30°)100例,200个根管(颊,舌弯曲根管),随机分为Reciproc组50例,100个根管,Protaper组50例,100个根管,进行根管预备。测量术前片、插针片、主尖片的根管弯曲度,比较根管偏移率,评价根管成形和根尖封闭效果。结果2组机用镍钛锉备根成功率:Reciproc组99%,Protaper组92%,有显著性差异( P<0.05)。结论 Reciproc的创新设计,使预备磨牙弯曲根管成形佳,反应轻,根尖封闭好,快捷高效,实现了一支锉代替一组锉。 展开更多
关键词 往复运动 根管预备 reciproc 偏移度
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Low temperature quasi-superplasticity of ZK60 alloy prepared by reciprocating extrusion 被引量:5
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作者 杨文朋 郭学锋 杨凯军 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第2期255-261,共7页
Fine-grained ZK60 alloy was prepared by 2-pass reciprocating extrusion, and the low temperature superplasticity was conducted in a temperature range from 443 to 523 K and an initial strain rate ranging from 3.3×1... Fine-grained ZK60 alloy was prepared by 2-pass reciprocating extrusion, and the low temperature superplasticity was conducted in a temperature range from 443 to 523 K and an initial strain rate ranging from 3.3×10^-4 to 3.3×10-2^s^-1. The results show that the alloy has an equiaxed grain structure with an average grain size of about 5.0μm, and the sizes of broken secondary particles and precipitates are no more than 175 and 50 nm, respectively. The alloy exhibits quasi-superplasticity with a maximum elongation of 270% at 523 K and an initial strain rate of 3.3×10^-4 s^-1. The strain rate sensitivity m is less than 0.2 at 443 and 473 K, and it is 0.42 at 523 K. The apparent activation energies at temperature below 473 K and at 523 K are less than 63.2 and 110.6 kJ/mol, respectively At temperature below 473 K, mainly intragranular sliding contributes to superplastic flow. At 523 K, grain boundary sliding is the dominant deformation mechanism, and dislocation creep controlled by grain boundary diffusion is considered to be the main accommodation mechanism. 展开更多
关键词 ZK60 Mg alloy reciprocating extrusion QUASI-SUPERPLASTICITY intragranular sliding grain boundary sliding
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Reciproc和Mtwo两种镍钛根管预备系统在下颌第一磨牙一次法根管治疗术中的应用对比 被引量:4
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作者 周岚 《中国当代医药》 2017年第17期92-94,共3页
目的评价应用Reciproc和Mtwo两种镍钛根管预备系统在下颌第一磨牙一次法根管治疗术中的效果差异。方法选择2015年6月~2016年6月在我院行下颌第一磨牙一次法根管治疗术的72例患者,随机分为R组和M组,各组36例分别在基础治疗之上采用Recip... 目的评价应用Reciproc和Mtwo两种镍钛根管预备系统在下颌第一磨牙一次法根管治疗术中的效果差异。方法选择2015年6月~2016年6月在我院行下颌第一磨牙一次法根管治疗术的72例患者,随机分为R组和M组,各组36例分别在基础治疗之上采用Reciproc和Mtwo两种镍钛根管预备系统进行根管预备后行根管填充,术后随访6个月,比较两组患者根管预备时间、根管预备并发症(如髓腔穿孔、台阶和器械折断)、根管填充情况和根管治疗约诊间痛(EIAP)以及术后6个月的疗效差异。结果 R组和M组的根管准备时间分别为(120.23±38.67)s和(72.82±36.22)s,R组的EIAP发生率和疼痛程度明显低于M组,差异有统计学意义(P<0.05)两组根管预备并发症发生率、根管恰填率、以及术后6个月的疗效均无统计学差异(P>0.05)。结论与Mtwo镍钛;根管预备系统相比,在下颌第一磨牙一次法根管治疗术中应用Reciproc镍钛根管预备系统的根管准备时间较短,患者疼痛反应较小,而临床疗效无统计学差异,值得推广。 展开更多
关键词 根管准备 reciproc Mtwo 下颌第一磨牙
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Protaper next和Reciproc在一次法根管治疗术中的应用效果比较 被引量:3
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作者 周立波 戴辛鹏 +2 位作者 王晗 赵玥 刘陆斌 《医学理论与实践》 2019年第18期2948-2950,共3页
目的:探讨比较Protaper next和Reciproc在一次法根管治疗术中的应用效果。方法:将我院2017年11月-2018年11月接收的90例行一次法根管治疗的病人随机均分为PTN组(采用Protaper next根管预备系统)与RP组(采用Reciproc根管预备系统),比较... 目的:探讨比较Protaper next和Reciproc在一次法根管治疗术中的应用效果。方法:将我院2017年11月-2018年11月接收的90例行一次法根管治疗的病人随机均分为PTN组(采用Protaper next根管预备系统)与RP组(采用Reciproc根管预备系统),比较二组的根管预备时间、疼痛率及有效率。结果:PTN组每个根管的平均预备时间显著长于RP组(P<0.05);根管治疗1周后,PTN组的疼痛率显著低于RP组(P<0.05);二组治疗总有效率比较差异无统计学意义(P>0.05)。结论:Protaper next及Reciproc根管预备系统疗效相当,但Reciproc的根管预备用时较短,Protaper next的术后疼痛发生率较低。 展开更多
关键词 PROTAPER NEXT reciproc 一次法根管治疗术 应用效果
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VDW Reciproc Blue单支锉与传统根管治疗器械在牙髓炎治疗中的疗效对比 被引量:3
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作者 王立臣 汤文兵 陈珍 《广东医科大学学报》 2022年第6期691-693,共3页
目的对比VDW Reciproc Blue单支锉与传统根管治疗器械在牙髓炎治疗中的疗效。方法将60例牙髓炎患者随机分为对照组与实验组,每组30例。对照组采用传统根管预备器械,实验组采用VDW Reciproc Blue单支锉,比较两组的根管预备成型效果(根管... 目的对比VDW Reciproc Blue单支锉与传统根管治疗器械在牙髓炎治疗中的疗效。方法将60例牙髓炎患者随机分为对照组与实验组,每组30例。对照组采用传统根管预备器械,实验组采用VDW Reciproc Blue单支锉,比较两组的根管预备成型效果(根管流畅度)、根管填充效果、Negm分级(疼痛状态分级)、器械折断率及根管预备时间。结果实验组根管流畅度与根管填充效果均优于对照组(P<0.05);Negm分级轻于对照组(P<0.05)。实验组根管预备时间短于对照组(P<0.01)。结论VDW Reciproc Blue单支锉能够减少患者椅旁时间、减轻术后疼痛和提高治疗效果。 展开更多
关键词 VDW reciproc Blue单支锉 传统根管治疗器械 牙髓炎 疗效
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Reciproc单支锉清除iRoot SP糊剂单尖法根管充填材料的再治疗效率研究 被引量:2
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作者 高萍 王月秋 +1 位作者 游冬冬 严章勇 《中国医药科学》 2023年第14期157-161,共5页
目的以AH糊剂冷侧压法、热牙胶垂直加压法为对照,口腔锥形束CT(CBCT)三维重建评价使用Reciproc单支锉去除iRoot SP糊剂单尖法术后根管充填材料的再治疗效率。方法选择福建医科大学附属福州市第一医院口腔科2021年7—11月正畸拔除的卵圆... 目的以AH糊剂冷侧压法、热牙胶垂直加压法为对照,口腔锥形束CT(CBCT)三维重建评价使用Reciproc单支锉去除iRoot SP糊剂单尖法术后根管充填材料的再治疗效率。方法选择福建医科大学附属福州市第一医院口腔科2021年7—11月正畸拔除的卵圆形单根管下颌前磨牙90个,采用随机数表法分为iRoot SP糊剂单尖法组(1组)、热牙胶垂直加压组(2组)和AH糊剂冷侧压组(3组)。使用Reciproc单支锉再治疗,终末超声荡洗2 min。分别于根充术后、再治疗、超声荡洗后CBCT扫描并三维重建,记录再治疗时间、根管残余充填材料体积。结果1组再治疗耗时最长,2组最短,差异有统计学意义(P<0.05)。1组残余充填材料最多,大于2组,差异有统计学意义(P<0.05),大于3组,但差异无统计学意义(P>0.05)。超声荡洗后,1组残余量大幅度减少,差异有统计学意义(P<0.05);最终残余量大于2组,差异有统计学意义(P<0.05),大于3组,但差异无统计学意义(P>0.05)。结论无论哪种充填方法,Reciproc单支锉再治疗均不能完全去除充填材料。iRoot SP糊剂单尖法进行再治疗耗时最多,残余量也最多,超声荡洗能够显著减少残余量。 展开更多
关键词 根管再治疗 iRoot SP 单尖法 reciproc单支锉 超声荡洗
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MICROSTRUCTURE OF Mg-6.4Zn-1.1Y ALLOY FABRICATED BY RAPID SOLIDIFICATION AND RECIPROCATING EXTRUSION 被引量:7
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作者 Z.M. Zhang C.J. Xu X.F. Guo 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2008年第1期30-36,共7页
In order to explore the methods to prepare high-strength quasicrystal-reinforced magnesium alloys, the flakes of rapidly solidified Mg-6.4Zn-1.1 Y magnesium alloy with a thickness of 50-60μm were obtained by a melt s... In order to explore the methods to prepare high-strength quasicrystal-reinforced magnesium alloys, the flakes of rapidly solidified Mg-6.4Zn-1.1 Y magnesium alloy with a thickness of 50-60μm were obtained by a melt spinning single-roller device, and the flakes were then processed into rods by reciprocating extrusion and direct extrusion. The microstructure of the alloy was analyzed by optical microscope and SEM, and the constituent phases were identified by XRD. Phase transformation and its onset temperature were determined by differential thermal analyzer (DTA). The analysis result shows that rapid solidification for Mg-6.4Zn-I.IY alloy can inhibit the eutectic reactions, broaden the solid solubility of Zn in α-Mg solute solution, and impede the formation of Mg3 Y2Zn3 and MgZn2 compounds, and thus help the icosahedral Mg3 YZn6 quasicrystal formed directly from the melt. The microstructure of the flakes consists of the α-Mg solid solution and icosahedral Mg3 YZn6 quasicrystal. Dense rods can be made from the flakes by two-pass reciprocating extrusion and direct extrusion. The interfaces between flakes in the rods can be welded and jointed perfectly. During the reciprocating extrusion and direct extrusion process, more Mg3 YZn6 compounds are precipitated and distributed uniformly, whereas the rods possess fine microstructures inherited from rapidly solidified flakes. The rods contain only two phases: α- magnesium solid solution as matrix and fine icosahedral Mg3 YZn6 quasicrystal which disperses uniformly in the matrix. 展开更多
关键词 Magnesium alloy Rapid solidification reciprocating extrusion QUASICRYSTAL
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Valve Dynamic and Thermal Cycle Model in Stepless Capacity Regulation for Reciprocating Compressor 被引量:9
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作者 JIN Jiangming HONG Weirong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2012年第6期1151-1160,共10页
The existing researches of stepless capacity regulation system by depressing the suction valve for reciprocation compressor always adopt hypothesis that the compressor valves are open or close instantaneously, the val... The existing researches of stepless capacity regulation system by depressing the suction valve for reciprocation compressor always adopt hypothesis that the compressor valves are open or close instantaneously, the valve dynamic has not been taken account into thermal cycle computation, the influence of capacity regulation system on suction valves dynamic performance and cylinder thermal cycle operation has not been considered. This paper focuses on theoretical and experimental analysis of the valve dynamic and thermal cycle for reciprocating compressor in the situation of stepless capacity regulation. The valve dynamics equation, gas forces for normal and back flow, and the cylinder pressure varying with suction valve unloader moment during compression thermal cycle are discussed. A new valve dynamic model based on L-K real gas state equation for reciprocating compressor is first deduced to reduce the calculation errors induced by the ideal gas state equation. The variations of valve dynamic and cylinder pressure during part of compression stroke are calculated numerically. The calculation results reveal the non-normal thermal cycle and operation condition of compressor in stepless capacity regulation situation. The numerical simulation results of the valve dynamic and thermal cycle parameters are also verified by the stepless capacity regulation experiments in the type of 3L-10/8 reciprocating compressor. The experimental results agree with the numerical simulation results, which show that the theoretical models proposed are effective and high-precision. The proposed theoretical models build the theoretical foundation to design the real stepless capacity regulation system. 展开更多
关键词 reciprocating compressor valve dynamic thermal cycle model stepless capacity regulation
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RECIPROCATING EXTRUSION OF IN SITU Mg_2Si REINFORCED Mg-Al BASED COMPOSITE 被引量:8
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作者 Z.M. Zhang C.J. Xu X.F. Guo S.Z. Jia 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2008年第3期169-177,共9页
M92Si reinforced Mg-Al based composite with high amount o/silicon was prepared by permanent mould casting, and then extruded by reciprocating extrusion (RE) after the composite was processed by homogenization heat t... M92Si reinforced Mg-Al based composite with high amount o/silicon was prepared by permanent mould casting, and then extruded by reciprocating extrusion (RE) after the composite was processed by homogenization heat treatment. The effect of RE processing on the morphology and size of M92Si and the mechanical properties of the com- posite were investigated, to develop new ways to refine the M928i phase and improve its shape. The result showed that RE was very useful in refining the M92Si phase. The more the RE processing passes, the better the refining effect would be. Moreover, the uniform distribution of M928i phases would be more in the composite. After the composite was processed by RE for 12 passes, most M92Si phases were equiaxed, with granular diameter below 20 μm, and distributed uniformly in the matrix of the composite. The mechanical properties of the composite could be increased prominently by RE processing, and were much higher than that in the as-cast state. As the temperature rises, the tensile strength is reduced. For the composite RE processed for 12 passes, the tensile strength, yield strength, and elongation are 325.9 MPa, 211.4 MPa, and 3.3% at room temperature, whereas, 288.2 MPa, ,207.7 MPa, and 7.8%, respectively, at 150℃. In comparison with the properties at room temperature, the tensile strength and yield strength are high and only decrease by 11.6% and 1.8% at 150℃. The M928i reinforced Mg-Al based composite possesses good heat resistance at 150℃. The excellent resistance to effect of heat is attributed to the high melting tempera- ture and good thermal stability of fine Mg2Si phases, which are distributed uniformly in the composite, and effectively hinder the grain boundary gliding and dislocation movement. 展开更多
关键词 reciprocating extrusion Magnesium alloy In situ composite Elevated temperature property
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Fluid-solid Interaction Model for Hydraulic Reciprocating O-ring Seals 被引量:11
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作者 LIAO Chuanjun HUANG Weifeng +2 位作者 WANG Yuming SUO Shuangfu LIU Ying 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第1期85-94,共10页
Elastohydrodynamic lubrication characteristics of hydraulic reciprocating seals have significant effects on sealing and tribology performances of hydraulic actuators, especially in high parameter hydraulic systems. On... Elastohydrodynamic lubrication characteristics of hydraulic reciprocating seals have significant effects on sealing and tribology performances of hydraulic actuators, especially in high parameter hydraulic systems. Only elastic deformations of hydraulic reciprocating seals were discussed, and hydrodynamic effects were neglected in many studies. The physical process of the fluid-solid interaction effect did not be clearly presented in the existing fluid-solid interaction models for hydraulic reciprocating O-ring seals, and few of these models had been simultaneously validated through experiments. By exploring the physical process of the fluid-solid interaction effect of the hydraulic reciprocating O-ring seal, a numerical fluid-solid interaction model consisting of fluid lubrication, contact mechanics, asperity contact and elastic deformation analyses is constructed with an iterative procedure. With the SRV friction and wear tester, the experiments are performed to investigate the elastohydrodynamic lubrication characteristics of the O-ring seal. The regularity of the friction coefficient varying with the speed of reciprocating motion is obtained in the mixed lubrication condition. The experimental result is used to validate the fluid-solid interaction model. Based on the model, The elastohydrodynamic lubrication characteristics of the hydraulic reciprocating O-ring seal are presented respectively in the dry friction, mixed lubrication and full film lubrication conditions, including of the contact pressure, film thickness, friction coefficient, liquid film pressure and viscous shear stress in the sealing zone. The proposed numerical fluid-solid interaction model can be effectively used to analyze the operation characteristics of the hydraulic reciprocating O-ring seal, and can also be widely used to study other hydraulic reciprocating seals. 展开更多
关键词 reciprocating O-ring seal elastohydrodynamic lubrication finite-element method fluid-solid interaction mixed lubrication SRV friction and wear tester
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