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On minimal quasi-injective modules and strong Kasch modules 被引量:2
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作者 朱占敏 张小向 《浙江大学学报(理学版)》 CAS CSCD 北大核心 2009年第3期243-248,253,共7页
设R为一个环,M为一个右R-模.若每个从M的单子模到M的同态都可以开拓为M的自同态,则称M为一个极小拟内射模.若每个单的右R-模都可以嵌入M,则称M为一个强Kasch模.本文研究了这两类模的一些刻画和性质.
关键词 极小拟内射模 强Kasch模 半完全环 半局部环
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Three-dimensional(3D) Printing Technology Assisted by Minimally Invasive Surgery for Pubic Rami Fractures 被引量:8
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作者 Wen-bo NIE Fa-gang YE +4 位作者 Jian-lin MA Jiang-ping YU Ming-xing WANG Zhen-hua ZHANG Fu-jie SUN 《Current Medical Science》 SCIE CAS 2018年第5期827-833,共7页
The feasibility of three-dimensional (3D) printing technology cgmbined with minimally invasive surgery in the treatment of pubic rami fractures was explored.From August 2015 to October 2017,a series of 30 patients who... The feasibility of three-dimensional (3D) printing technology cgmbined with minimally invasive surgery in the treatment of pubic rami fractures was explored.From August 2015 to October 2017,a series of 30 patients who underwent surgical stabilization of their anterior pelvic ring (all utilizing the 3D printing technology)by one surgeon at a single hospital were studied.The minimally invasive incisions were made through anterior inferior cilia spine and pubic nodule.Data collected included the operative duration,the blood loss,the damage of the important tissue,the biographic union and therecovery of the function after the operation.Measurements on inlet and outlet pelvic cardiograph were made immediately post-operation and at all follow-up clinic visits.The scores of reduction and function were measured during follow-up.Results showed that the wounds of 30 patients were healed in the first stage,and there was no injury of important structures such as blood vessels and nerves.According to the Matta criteria,excellent effectiveness was obtained in 22 cases and good in 8 cases.According to the functional evaluation criteria of Majeed,excellent effectiveness was obtained in 21 cases and good in 9 cases.It was suggested that the 3D printing technology assisted by minimally invasive surgery can better evaluate the pelvic fracture before operation,which was helpful in plate modeling, and can shorten surgery duration and reduce intraoperative blood loss and complications. The positioning accuracy was improved,and better surgical result was finally achieved. 展开更多
关键词 digital design THREE-DIMENSIONAL printing ANTERIOR ring PELVIC FRACTURES minimalLY INVASIVE surgery
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Minimally Invasive Surgical Technique in Double Aortic Arch with Distal Atretic Left-Side in Infant:From a Single-Surgeon Clinical Experience
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作者 Qi Liu Shoujun Li Zhongdong Hua 《Congenital Heart Disease》 SCIE 2022年第5期533-539,共7页
Background:Double aortic arch(DAA)with distal left-sided aortic arch atresia(LAAA)can form complete vascular ring by ligamentum connection.We aimed to introduce an uncommon DAA-LAAA diagnosis and treatment by the mini... Background:Double aortic arch(DAA)with distal left-sided aortic arch atresia(LAAA)can form complete vascular ring by ligamentum connection.We aimed to introduce an uncommon DAA-LAAA diagnosis and treatment by the minimally invasive surgical technique(MIST).Methods:We retrospectively reviewed 7 cases of DAA-LAAA that were treated from January 2017 to July 2021.All infant patients underwent surgical repair by minimally invasive surgical technique.Mean follow-up was 14.43 months(range,5–21 months).Results:There were seven patients with DAA-LAAA,including six males and one female.Median age was 19.29 months(range,9.0–29.0 months).Median weight was 11.30 kg(range,9.6–13.0 kg).Three patients were found severe tracheal compression by cardiac computed tomography angiography(cCTA).Six patients with isolated DAA-LAAA were performed operations through left subaxillary minithoracotomy,and one patient with ventricular septal defect(VSD)was performed operation concurrently under the cardiopulmonary bypass(CPB)through right subaxillary minithoracotomy.All patients had symptom improvement in the postoperative period and discharged successfully.Follow-up data showed good results in short-term.Conclusions:We introduce a new surgical pathway for DAA-LAAA treatment with good symptomatic relief in short-term.MIST is a safe,feasible and economical approach for infant patients. 展开更多
关键词 Double aortic arch complete vascular ring minimally invasive surgical technique
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A unified analysis of a micro-beam,droplet and CNT ring adhered on a substrate:Calculation of variation with movable boundaries 被引量:3
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作者 Jian-Lin Liu Re Xia 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2013年第1期62-72,共11页
In this study, we developed a general method to analytically tackle a kind of movable boundary problem from the viewpoint of energy variation. Having grouped the adhesion of a micro-beam, droplet and carbon nanotube ... In this study, we developed a general method to analytically tackle a kind of movable boundary problem from the viewpoint of energy variation. Having grouped the adhesion of a micro-beam, droplet and carbon nanotube (CNT) ring on a substrate into one framework, we used the developed line of reasoning to investigate the adhesion behaviors of these systems. Based upon the derived governing equations and transversality conditions, explicit solutions involving the critical parameters and morphologies for the three systems are successfully obtained, and then the parameter analogies and common characteristics of them are thor- oughly investigated. The presented method has been verified via the concept of energy release rate in fracture mechanics. Our analyses provide a new approach for exploring the mechanism of different systems with similarities as well as for understanding the unity of nature. The analysis results may be beneficial for the design of nano-structured materi- als, and hold potential for enhancing their mechanical, chemical, optical and electronic properties. 展开更多
关键词 Variational theory - Transversality condition Beam adhesion Droplet adhesion Carbon nanotube ring adhesion
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ON STRONGLY REGULAR RINGS
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作者 Huang Junmin(Dept. of Applied Mathematics) 《Journal of Shanghai Jiaotong university(Science)》 EI 1996年第2期6-8,16,共4页
?The multiplication semigroup of strongly regular ring R in the light of semigroup is researched,hence some properties of strongly regular rings are obtained. The non-division strongly regular ring R is anilpotent sem... ?The multiplication semigroup of strongly regular ring R in the light of semigroup is researched,hence some properties of strongly regular rings are obtained. The non-division strongly regular ring R is anilpotent semisimple ring without identity element. It is neither the Artin ring nor the Noether ring. The setidempotents of ring R is an infinite set without the maximum and minimal conditions,it is a unions of someorder sets and hai a non-well-ordered order set at least. 展开更多
关键词 STRONGLY REGULAR ring maximum CONDITION minimal CONDITION IDEMPOTENT element well-ordered chain
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On Finite Rank Operators on Centrally Closed Semiprime Rings
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作者 J. C. Cabello R. Casas P. Montiel 《Advances in Pure Mathematics》 2014年第9期499-505,共7页
We prove that the multiplication ring of a centrally closed semiprime ring R has a finite rank operator over the extended centroid C iff R contains an idempotent q such that qRq is finitely generated over C and, for e... We prove that the multiplication ring of a centrally closed semiprime ring R has a finite rank operator over the extended centroid C iff R contains an idempotent q such that qRq is finitely generated over C and, for each , there exist and e an idempotent of C such that xz=eq. 展开更多
关键词 ring SEMIPRIME ring Extended CENTROID minimal IDEMPOTENT
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Formation of Hybrid Ring Structure of Cyanurate/Isocyanurate in the Reaction be-tween 2,4,6-Tris(4-Phenyl-Phenoxy)-1, 3,5-Triazine and Phenyl Glycidyl Ether
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作者 Daisuke Ohno Kazuya Zenyoji +2 位作者 Youji Kurihara Kazuyoshi Ueda Hitoshi Habuka 《International Journal of Organic Chemistry》 CAS 2016年第2期117-125,共9页
Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound w... Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound which were well known as reaction products of cyanate esters and epoxy resins, compounds with hybrid ring structure of cyanurate/isocyanurate were determined. Gibbs free energies of the compound having hybrid ring structure of cyanurate/isocyanurate with two isocyanurate moiety were found to be lower than that of the compound with cyanurate ring structure through calculations. Calculation data supported the existence of hybrid ring structure of cy-anurate/isocyanurate. It was revealed that isomerization from cyanurate to isocyanurate occurs via hybrid ring structure of cyanurate/isocyanurate in the reaction of aryl cyanurate and epoxy. 展开更多
关键词 Reaction products of 2 4 6-tris(4-phenyl-phenoxy)-1 3 5-triazine derived from 4-phenylphenol cya-nate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound which were well known as reaction products of cyanate esters and epoxy resins compounds with hybrid ring structure of cyanurate/isocyanurate were determined. Gibbs free energies of the compound having hybrid ring structure of cyanurate/isocyanurate with two isocyanurate moiety were found to be lower than that of the compound with cyanurate ring struc-ture through calculations. Calculation data supported the existence of hybrid ring structure of cy-anurate/isocyanurate. It was revealed that isomerization from cyanurate to isocyanurate occurs via hybrid ring structure of cyanurate/isocyanurate in the reaction of aryl cyanurate and epoxy.
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术中滑轨CT辅助在经皮骶髂关节螺钉治疗骨盆后环损伤中的应用 被引量:1
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作者 盛斌 王奕威 +4 位作者 王愉思 刘德龙 杨瞻宇 关蕊 刘超 《中国骨伤》 CAS CSCD 2024年第5期438-444,共7页
目的:比较术中滑轨CT联合C形臂X线机辅助与单纯使用C形臂X线机辅助透视下经皮骶髂关节螺钉治疗骨盆后环损伤临床疗效。方法:自2018年12月至2022年2月收治76例骨盆后环损伤患者,其中,C形臂联合滑轨CT辅助下行内固定治疗39例为CT组,男23例... 目的:比较术中滑轨CT联合C形臂X线机辅助与单纯使用C形臂X线机辅助透视下经皮骶髂关节螺钉治疗骨盆后环损伤临床疗效。方法:自2018年12月至2022年2月收治76例骨盆后环损伤患者,其中,C形臂联合滑轨CT辅助下行内固定治疗39例为CT组,男23例,女16例,年龄(44.98±7.33)岁;仅在C形臂透视下行内固定治疗37例为C形臂组,男24例,女13例,年龄(44.37±10.82)岁。合并有前环骨折患者42例,均采用经皮髂前下棘内置外固定架(internal fixation,INFIX)或耻骨上支螺钉固定骨盆前环。术后比较两组随访时间、置钉时间、并发症。比较两组Matta复位评价、Majeed疗效评价、CT分级及二次手术翻修率。结果:CT组置钉时间(32.63±7.33) min,短于C形臂组(52.95±10.64) min(t=-9.739,P<0.05)。CT组随访时间(11.97±1.86)个月,C形臂组(12.03±1.71)个月,两组比较差异无统计学意义(P>0.05)。两组术后并发症发生比较,差异无统计学意义(χ~2=0.159,P>0.05)。CT组Matta复位评价结果(Z=2.79,P<0.05)、Majeed疗效评价结果(Z=2.79,P<0.05)、CT分级(Z=2.83,P<0.05)均优于C形臂组。CT组二次手术翻修率低于C形臂组(χ~2=5.641,P<0.05)。结论:术中滑轨CT联合C形臂辅助下经皮骶髂关节螺钉置入手术与传统C形臂透视相比,具有手术时间短、准确度及安全性高、术后二次翻修率显著下降等特点,是重建骨盆骨折后环稳定性的有效方法之一。 展开更多
关键词 滑轨CT 经皮骶髂关节螺钉 骨盆后环损伤 术中透视 微创
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两种内固定治疗骨盆前环骨折的疗效比较 被引量:1
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作者 徐练 林旭 +4 位作者 吴超 谭伦 钟泽莅 曾俊 胡海刚 《临床骨科杂志》 2024年第3期390-394,共5页
目的比较经皮空心螺钉内固定与皮下钉棒系统内固定(INFIX)治疗骨盆前环骨折的疗效。方法将43例骨盆前环骨折患者根据内固定方式不同分为经皮空心螺钉组(19例)和INFIX组(24例)。记录手术时间、术中出血量、术中透视次数、术后下地时间、... 目的比较经皮空心螺钉内固定与皮下钉棒系统内固定(INFIX)治疗骨盆前环骨折的疗效。方法将43例骨盆前环骨折患者根据内固定方式不同分为经皮空心螺钉组(19例)和INFIX组(24例)。记录手术时间、术中出血量、术中透视次数、术后下地时间、骨折复位质量、骨折愈合时间以及并发症发生情况,采用Matta影像学标准评价骨折复位质量,采用Majeed评分系统评价临床疗效。结果患者均获得随访,时间12~24个月。手术时间、术后下地时间、骨折复位质量优良率、骨折愈合时间两组比较差异均无统计学意义(P>0.05)。术中出血量经皮空心螺钉组少于INFIX组(P<0.05)。术中透视次数经皮空心螺钉组多于INFIX组(P<0.05)。并发症发生率经皮空心螺钉组低于INFIX组(P<0.05)。末次随访时,两组疗效优良率比较差异无统计学意义(P>0.05)。结论采用经皮空心螺钉内固定与INFIX治疗骨盆前环骨折临床疗效相当,经皮空心螺钉内固定具有术中出血量少、并发症发生率低的优点,但存在术中透视次数较多的不足。 展开更多
关键词 骨盆前环骨折 微创手术 经皮空心螺钉 经皮钉棒系统
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经皮椎间孔镜治疗椎体后缘离断症的手术技巧及短期疗效观察
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作者 李成勇 石志 +4 位作者 龚志强 娄振凯 赵石好 苗辉 王兵 《颈腰痛杂志》 2024年第2期248-251,共4页
目的探讨经皮椎间孔镜手术(percutaneous endoscopic lumbar discectomy,PELD)治疗腰椎椎体后缘离断症(posterior apophyseal ring separation,PARS)的手术技巧及短期疗效。方法纳入PELD治疗的腰椎PARS患者53例,均采用症状较重侧椎间孔... 目的探讨经皮椎间孔镜手术(percutaneous endoscopic lumbar discectomy,PELD)治疗腰椎椎体后缘离断症(posterior apophyseal ring separation,PARS)的手术技巧及短期疗效。方法纳入PELD治疗的腰椎PARS患者53例,均采用症状较重侧椎间孔入路,通过恰当的手术技巧摘除突出椎间盘、摘除全部或部分离断骨块。于术前和术后3个月、1年、2年时,通过视觉模拟评分(visual analogue scale,VAS)评价患者腰、腿痛改善情况,Oswestry残疾指数(oswestry disability index,ODI)评估腰椎功能改善程度,采用改良MacNab标准评估疗效。结果所有手术顺利,无神经损伤、硬膜撕破及感染等并发症。复查CT显示减压良好,离断骨块全部切除32例,部分切除21例。所有患者均获得2年随访,与术前相比,术后腰、腿痛VAS和腰椎ODI均明显降低,差异有统计学意义(P<0.001);疗效评估优良率为94.34%。结论PELD治疗腰椎PARS具有创伤小、康复快、疗效好等优点,可作为手术治疗PARS的良好选择。 展开更多
关键词 腰椎椎体后缘离断症 经皮椎间孔镜 微创
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Quasi-duo环的刻画 被引量:8
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作者 魏俊潮 《扬州大学学报(自然科学版)》 CAS CSCD 2006年第3期1-4,共4页
证明了如下结果:1)环R是左quas i-duo环当且仅当对任意x J(R),y∈R,Ry+R(yx-1)=R;2)环R是左quas i-duo环当且仅当R是左极小A be l环和左M ELT环.
关键词 quasi-duo环 JACOBSON根 左极小幂等元 直接有限环
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微创经皮空心螺钉内固定治疗骨盆前环骨折的效果分析 被引量:1
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作者 任占锋 陈同林 《中国社区医师》 2024年第14期25-27,共3页
目的:分析微创经皮空心螺钉内固定治疗骨盆前环骨折的临床效果。方法:选取2020年3月—2022年3月北京市上地医院和北京大望路急诊抢救医院收治的骨盆前环骨折患者66例作为研究对象,根据随机数字表法分为对照组与观察组,各33例。对照组实... 目的:分析微创经皮空心螺钉内固定治疗骨盆前环骨折的临床效果。方法:选取2020年3月—2022年3月北京市上地医院和北京大望路急诊抢救医院收治的骨盆前环骨折患者66例作为研究对象,根据随机数字表法分为对照组与观察组,各33例。对照组实施开放复位内固定术,观察组实施微创经皮空心螺钉内固定术。比较两组治疗效果。结果:观察组骨折复位总优良率高于对照组,差异有统计学意义(P=0.039)。观察组术中出血量少于对照组,术后下床活动时间、骨痂形成时间早于对照组,差异有统计学意义(P<0.001)。术后3、6、8个月,两组骨盆功能评分逐渐升高,且观察组高于对照组,差异有统计学意义(P<0.001)。观察组并发症总发生率低于对照组,差异有统计学意义(P=0.046)。结论:微创经皮空心螺钉内固定治疗骨盆前环骨折的效果显著,可减少术中出血量,加速康复,提高骨折复位优良率,降低并发症发生率。 展开更多
关键词 骨盆前环骨折 微创经皮空心螺钉内固定 骨折复位
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Lie环分解中的Krull-Schmidt定理
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作者 廖军 刘合国 《数学物理学报(A辑)》 CSCD 北大核心 2009年第2期399-405,共7页
该文得到了Lie环分解的Krull—Schmidt定理:若L是在理想上满足极大、极小条件的Lie环,如果L=H1+H2+…+Hr=K1+K2+…+Ks是L的两个Remak分解,即Hi和Kj是不可分解的,那么r=s,并且存在L的一个中心自同构a,使在适当排列Kj的顺序后... 该文得到了Lie环分解的Krull—Schmidt定理:若L是在理想上满足极大、极小条件的Lie环,如果L=H1+H2+…+Hr=K1+K2+…+Ks是L的两个Remak分解,即Hi和Kj是不可分解的,那么r=s,并且存在L的一个中心自同构a,使在适当排列Kj的顺序后,Hi^a=Ki,进一步地,对任意的k=1,2,…,r,L=K1+K2…+Kk+Hk+1+…Hr.如果L=H1+H2+…Hr是L的一个Remak分解,那么这个分解是L的唯一Remak分解当且仅当对L的任意正规自同态θ有Hi^θ≤Hi,i=1,2,…,r. 展开更多
关键词 Krull—Schmidt定理 LIE环 直和分解 极大极小条件.
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Auslander-型环上的合冲模
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作者 黄宠辉 《佳木斯大学学报(自然科学版)》 CAS 2014年第6期934-936,共3页
研究了Auslander-型环上合冲模的性质.通过模的极小内射分解,定义了一类比合冲模类更广的模类,讨论了这种模类与合冲模类相等的必要条件与充分条件.
关键词 Auslander-型环 合冲模 极小内射分解
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微创经皮钢板内固定术与皮下内固定支架术治疗骨盆前环骨折患者的效果比较
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作者 王再军 王兴焱 陈州 《中国民康医学》 2024年第15期156-158,162,共4页
目的:比较微创经皮钢板内固定术与皮下内固定支架术治疗骨盆前环骨折患者的效果。方法:回顾性分析2020年6月至2022年6月该院收治的106例骨盆前环骨折患者的临床资料,根据术式不同将其分为观察组(n=53)、对照组(n=53)。对照组采用皮下内... 目的:比较微创经皮钢板内固定术与皮下内固定支架术治疗骨盆前环骨折患者的效果。方法:回顾性分析2020年6月至2022年6月该院收治的106例骨盆前环骨折患者的临床资料,根据术式不同将其分为观察组(n=53)、对照组(n=53)。对照组采用皮下内固定支架术治疗,观察组采用微创经皮钢板内固定术治疗,比较两组手术相关指标(住院时间、手术时间、骨折愈合时间、术中出血量)水平、血清骨转化状态指标[骨特异性碱性磷酸酶(BAP)、骨钙素(OCN)、总I型胶原氨基端延长肽(T-P1NP)]水平、骨盆垂直移位距离和并发症发生率。结果:观察组住院时间、手术时间、骨折愈合时间均短于对照组,术中出血量少于对照组,差异均有统计学意义(P<0.05);术后2周,两组血清BAP、OCN水平高于术前,且观察组高于对照组,两组血清T-P1NP水平低于术前,且观察组低于对照组,差异均有统计学意义(P<0.05);术后6个月,两组骨盆垂直移位距离均短于术前,且观察组短于对照组,差异有统计学意义(P<0.05);两组并发症发生率比较,差异无统计学意义(P>0.05)。结论:微创经皮钢板内固定术治疗骨盆前环骨折患者可改善骨转化状态指标水平,降低手术相关指标水平,缩短骨盆垂直移位距离,效果优于皮下内固定支架术治疗。 展开更多
关键词 骨盆前环骨折 微创经皮钢板内固定术 皮下内固定支架术 骨转化 骨盆垂直移位 并发症
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交流电磁铁短路环的设计
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作者 李新叶 冉勇 +1 位作者 郑云 史亚闻 《电工电气》 2024年第5期58-62,73,共6页
为了解决接触器动、静铁心出现的频率振动问题,接触器交流电磁系统通常是在铁心上增加短路环。介绍了接触器交流电磁系统铁心短路环的作用及其工作原理,分析了短路环的结构参数对铁心最小吸力及平均吸力的影响。着重阐述了短路环内、外... 为了解决接触器动、静铁心出现的频率振动问题,接触器交流电磁系统通常是在铁心上增加短路环。介绍了接触器交流电磁系统铁心短路环的作用及其工作原理,分析了短路环的结构参数对铁心最小吸力及平均吸力的影响。着重阐述了短路环内、外磁通相位差对短路环性能的影响,给出了基于此磁通相位差来确定短路环综合参数的方法,同时通过数值计算予以理论论证,并以实际接触器研发应用证明了此设计方法的有效性。 展开更多
关键词 短路环 噪音 最小吸力 磁通相位差 短路环综合参数 滞后叠加
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Selective Construction of Borromean Rings and Tweezer-Like Molecular Assembly Featuring Cp^(*)Rh/Ir Clips for Near-Infrared Photothermal Conversion
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作者 Yan Zou Hai-Ning Zhang +2 位作者 Qiu-Shui Mu Li-Long Dang Guo-Xin Jin 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2023年第23期3229-3237,共9页
Making full use of coordination-driven self-assembly strategy,we herein described the selective synthesis of a molecular Borromean rings and two cases of “U”-shaped tweezer-like molecular assemblies in high yield by... Making full use of coordination-driven self-assembly strategy,we herein described the selective synthesis of a molecular Borromean rings and two cases of “U”-shaped tweezer-like molecular assemblies in high yield by using bipyridyl ligands based on biphenyl unit and half-sandwich binuclear rhodium(III)/iridium(III) building blocks.The selective synthesis was realized by adjusting the length of dipyridyl arms.The utilization of curved U-shaped bipyridyl ligand L1 led to tweezer-like molecular assemblies.Subsequently,olefinic bonds were introduced to elongate dipyridyl arms obtaining ligand L2.The ligand L2 has two stable conformations,U-shape and Z-shape,which facilitated the formation of different topologies including the tetranuclear macrocycle and Borromean rings with different building blocks in this work.These structures in solid and solution all have been further confirmed by single-crystal X-ray diffraction,NMR analysis,and mass spectrometry.In addition,as an important driving force,π-π stacking interactions not only played a significant role in the stability of structures but also further triggered photothermal conversion in solution.The experimental results demonstrated that compounds 1a and 2 had good NIR photothermal conversion efficiency (11.83% and 17.76%),and further analysis found the photothermal conversion efficiency had a gradual increase in the trend with the π-π stacking interactions increasing.This research expands the application of topological structures in materials science and provides a new idea for the synthesis of novel photothermal conversion materials. 展开更多
关键词 Self-assembly π-πstacking interaction Half-sandwich Cp*Rh/Ir Rhodium Iridium Borromean rings and Tweezer-like molecular assembly Near-infrared photothermal conversion
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任意Krull-Schmidt范畴中的右极小态射(英文)
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作者 边宁 《数学杂志》 CSCD 北大核心 2009年第5期577-580,共4页
本文研究任意Krull-Schmidt范畴中的右极小态射.利用半完全环众所周知的理论,证明了任意Krull-Schmidt范畴中右极小态射的基本定理,推广了具有有限长度模范畴上的经典结果[1].
关键词 半完全环 Krull—Schmidt范畴 右极小态射
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Lifting Minimal Resolutions over Zariskian Filtered Rings
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作者 Wang Zhixi Department of Mathematics, Capital Normal University, Beijing 100037, China 《Acta Mathematica Sinica,English Series》 SCIE CSCD 1997年第4期513-516,共4页
The correlation between the resolution for a Zariskian filtered ring R and that for its associated graded ring G(R) is discussed in this note. Then we show some examples satisfying the condition of the theorem.
关键词 Zariskian filtered ring minimal filt--projective resolution Gr-semiperfect ring
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A Mixed-valent Hexanuclear Cu~Ⅱ-Cu~ⅠComplex with Unusual Tridentate pbi Ligand (pbi = 2-(2-Pyridyl)-benzimidazole)
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作者 刘九辉 吴小园 +2 位作者 张全争 何翔 卢灿忠 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2006年第12期1507-1511,共5页
A mixed-valent hexanuclear complex [Cu^ⅡCu^Ⅰ2(pbi)2Br2]2 (pbi = (2-(2-pyridyl)-benzimidazole) exhibiting a dimeric unit bridged by two Br atoms was synthesized by hydrothermal reaction Interestingly, there ex... A mixed-valent hexanuclear complex [Cu^ⅡCu^Ⅰ2(pbi)2Br2]2 (pbi = (2-(2-pyridyl)-benzimidazole) exhibiting a dimeric unit bridged by two Br atoms was synthesized by hydrothermal reaction Interestingly, there exist intramolecular and intermolecular n^zstacking interactions as well as metalaromatic ring interactions in the title complex. The crystal belongs to the monoclinic system, space group P1, with a = 7.1061(9), b = 12.1008(13), c = 14.0711(17) A, α=91.742(8),β=100.155(9), γ=90.486(7)°, V = 1190.3(2) A^3, Z = 2, C48H32Br4CucoNt2, Mr = 1477.74, Dc= 2.061 g/cm^3, F(000) = 718, μ(MoKα) = 6.039 mm^-1, the final R = 0.0481 and wR = 0.0974 for 3426 observed reflections (I 〉 2σ(I)). 展开更多
关键词 mixed-valence π-π staeking interaction metal-aromatic ring interaction
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