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喷气涡流纺导引体结构参数的优化 被引量:1
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作者 尚珊珊 郁崇文 《南通大学学报(自然科学版)》 CAS 2012年第3期24-28,共5页
导引体是喷气涡流纺喷嘴的重要组成部分,为了研究导引体结构参数对纺纱的影响,对导引体的结构参数(螺旋角α、导引针长度L)进行了研究,选择5种螺旋角α(15°,30°,45°,60°,75°),4种导引针长度L(0.5,1,1.5,2 mm)... 导引体是喷气涡流纺喷嘴的重要组成部分,为了研究导引体结构参数对纺纱的影响,对导引体的结构参数(螺旋角α、导引针长度L)进行了研究,选择5种螺旋角α(15°,30°,45°,60°,75°),4种导引针长度L(0.5,1,1.5,2 mm),以粘胶纤维(39 mm×1.23 dtex)为原料在喷气涡流纺纱小样机上进行纺纱实验,实验结果表明:α=30°~45°,L=1~1.5 mm为导引体的最佳结构参数. 展开更多
关键词 喷气涡流纺 喷嘴 导引体 结构参数
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开放系统中多体量子导引的保护
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作者 孙文洋 曹浩 叶柳 《安徽科技学院学报》 2024年第3期96-101,共6页
目的:基于量子测量技术,研究如何保护开放系统中多体量子导引。方法:通过使用量子反转测量和量子弱测量的组合测量,得出保护多体量子导引的最优测量结果。结果:当无测量时,多体量子导引在退相干效应的影响下逐渐退化直至消失不见;当使... 目的:基于量子测量技术,研究如何保护开放系统中多体量子导引。方法:通过使用量子反转测量和量子弱测量的组合测量,得出保护多体量子导引的最优测量结果。结果:当无测量时,多体量子导引在退相干效应的影响下逐渐退化直至消失不见;当使用最优的测量结果时,多体量子导引随着测量强度的增强而逐渐恢复。结论:在开放系统中,量子弱测量能够有效地保护由于退相干效应而退化的多体量子导引。 展开更多
关键词 退相干效应 量子 量子弱测量
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采用弹体追踪导引律的旋转弹锥形运动稳定性
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作者 宋金超 赵良玉 《兵工学报》 EI CAS CSCD 北大核心 2023年第6期1795-1808,共14页
针对旋转弹采用捷联导引头和弹体追踪导引律时可能导致锥形运动失稳的问题,推导了捷联导引头在非旋转弹体坐标系下的动力学模型,建立了复数形式的弹体追踪制导控制系统数学模型;在不同弹体转速及阻尼回路增益情况下,分别考虑导引头响应... 针对旋转弹采用捷联导引头和弹体追踪导引律时可能导致锥形运动失稳的问题,推导了捷联导引头在非旋转弹体坐标系下的动力学模型,建立了复数形式的弹体追踪制导控制系统数学模型;在不同弹体转速及阻尼回路增益情况下,分别考虑导引头响应延迟和陀螺标度因数误差,分析了上述制导控制系统的稳定性,并使用数值方法求得使其稳定的特征参数取值范围。研究结果表明:导引头延迟角越大,使系统稳定的制导回路增益上限越小;陀螺标度因数误差系数大于1时,使系统稳定的制导回路增益上限会变大,当陀螺标度因数误差系数小于1时,使系统稳定的制导回路增益稳定上限会变小。 展开更多
关键词 旋转弹 锥形运动 追踪 稳定性
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超声引导下门静脉穿刺导引经颈静脉肝内门体分流术联合曲张静脉栓塞治疗食管胃底静脉曲张破裂出血的临床效果 被引量:6
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作者 林纲毅 马洺远 蔡宗洋 《中国当代医药》 2020年第7期113-116,共4页
目的探讨超声引导下门静脉穿刺导引经颈静脉肝内门体分流术(TIPS)联合曲张静脉栓塞治疗食管胃底静脉曲张破裂出血的临床效果。方法选取2015年12月~2018年1月我院收治的60例食管胃底静脉曲张破裂出血患者作为研究对象,采用随机数字表法... 目的探讨超声引导下门静脉穿刺导引经颈静脉肝内门体分流术(TIPS)联合曲张静脉栓塞治疗食管胃底静脉曲张破裂出血的临床效果。方法选取2015年12月~2018年1月我院收治的60例食管胃底静脉曲张破裂出血患者作为研究对象,采用随机数字表法分为观察组(n=30)和对照组(n=30)。对照组采用传统TIPS路径联合经皮胃底曲张静脉栓塞术(PTVE)治疗,观察组采用超声引导下门静脉穿刺导引TIPS联合曲张静脉栓塞治疗。比较两组的手术指标、治疗前后的肝脏血管情况及肝功能指标。结果观察组的分流道穿刺次数少于对照组,分流道穿刺时间和手术时间短于对照组,分流道穿刺成功率高于对照组,差异均有统计学意义(P<0.05)。观察组治疗后的门静脉内径、脾静脉内径、肝动脉流速低于对照组,门静脉流速、脾静脉流速、肝动脉血管阻力指数(RI)高于对照组,差异均有统计学意义(P<0.05)。观察组治疗后的清蛋白水平高于对照组,总胆红素和丙氨酸氨基转移酶水平低于对照组,差异均有统计学意义(P<0.05)。结论超声引导下门静脉穿刺导引TIPS联合曲张静脉栓塞治疗食管胃底静脉曲张破裂出血可减少分流道穿刺次数,缩短分流道穿刺时间和手术时间,提高分流道穿刺成功率,改善患者的肝脏血管情况及肝功能指标。 展开更多
关键词 超声下门静脉穿刺经颈静脉肝内门分流术 曲张静脉栓塞 食管胃底静脉曲张破裂出血 临床对照研究
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基于导引头-弹体耦合模型和伴随制导系统的火箭弹脱靶量快速估计方法
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作者 崔梦曦 郝宏旭 +5 位作者 王新星 孟亮飞 毛昱天 万轲 刘耘臻 张妍 《兵工学报》 EI CAS CSCD 北大核心 2022年第10期2554-2564,共11页
导引头初步方案设计阶段快速估计制导系统脱靶量是缩短火箭弹研制进度的有效方法。依据刚体运动学和动力学原理,建立俯仰-偏航双框架稳定平台式导引头的耦合数学模型,模型重点考虑了导引头与弹体的耦合作用,在此基础上进一步提出伴随化... 导引头初步方案设计阶段快速估计制导系统脱靶量是缩短火箭弹研制进度的有效方法。依据刚体运动学和动力学原理,建立俯仰-偏航双框架稳定平台式导引头的耦合数学模型,模型重点考虑了导引头与弹体的耦合作用,在此基础上进一步提出伴随化制导系统脱靶量评估方法。利用导引头耦合数学模型、实际飞行试验数据和简单的制导系统设计参数,快速对火箭弹脱靶量作出估计,在导引头初步方案设计阶段快速更新设计参数、减少迭代设计过程。仿真结果表明,导引头耦合模型具有较高的精确度,结合伴随化方法可以快速估计脱靶量、为导引头和制导系统初步设计提供依据。 展开更多
关键词 火箭弹 脱靶量快速估计 头-弹耦合模型 伴随制系统
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量子导引在结构化环境中退相干演化 被引量:3
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作者 黄雨梦 杨志远 +1 位作者 谢燕青 郝翔 《云南大学学报(自然科学版)》 CAS CSCD 北大核心 2019年第2期291-297,共7页
以腔量子动力学系统为研究对象,讨论量子关联态的可导引性在结构化光场环境中演化规律.系统与各自环境的相互作用导致了量子退相干,其过程可以通过量子噪声信道描述.从数学几何角度,我们通过量子导引椭体球的动态形变和体积变化,研究两... 以腔量子动力学系统为研究对象,讨论量子关联态的可导引性在结构化光场环境中演化规律.系统与各自环境的相互作用导致了量子退相干,其过程可以通过量子噪声信道描述.从数学几何角度,我们通过量子导引椭体球的动态形变和体积变化,研究两体量子纠缠态中量子可导引性的动力学过程,分析了量子退相干对量子导引非对称性的影响.我们发现,随着量子关联态的演化,系统和各自环境的耦合会大大改变量子导引椭体球的形态,压缩其体积,从而降低量子导引.与单个系统经历量子噪声信道相比,在2个系统同时经历噪声信道的情形中,量子导引椭体球的形变更加剧烈.另一方面,当系统与环境发生强耦合时,与相同时间段内的弱耦合情况相比,量子导引的衰减被加速. 展开更多
关键词 量子 结构化环境 腔量子电动力学系统 量子噪声信道
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Prognostic value of the ratio between prosthesis area and indexed annulus area measured by MultiSlice-CT for transcatheter aortic valve implantation procedures 被引量:1
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作者 Nicolas Debry Arnaud Sudre +6 位作者 Ihrahim Elquodeimat Cedric Delhaye Guillaume Schurtz Antoine Bical Mohamad Koussa Khalil FaRouch Thomas Modine 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2016年第6期483-488,共6页
Background Postprocedural aortic regurgitations following transcatheter aortic valve implantation (TAVI) procedures remain an is- sue. Benefit of oversizing strategies to prevent them isn't well established. We com... Background Postprocedural aortic regurgitations following transcatheter aortic valve implantation (TAVI) procedures remain an is- sue. Benefit of oversizing strategies to prevent them isn't well established. We compared different level of oversizing in our cohort of con- secutive patients to address if severe oversizing compared to normal sizing had an impact on post-procedural outcomes. Methods From January 2010 to August 2013, consecutive patients were referred for TAVI with preoperative Multislice-CT (MSCT) and the procedures were achieved using Edwards Sapien~ or Corevalve devices~. Retrospectively, according to pre-procedural MSCT and the valve size, pa- tients were classified into three groups: normal, moderate and severe oversizing; depending on the ratio between the prosthesis area and the annulus area indexed and measured on MSCT. Main endpoint was mid-term mortality and secondary endpoints were the Valve Academic Research Consortium (VARC-2) endpoints. Results Two hundred and sixty eight patients had a MSCT and underwent TAVI procedure, with mainly Corevalve~. While all-cause and cardiovascular mortality rates were similar in all groups, post-procedural new pacemaker (PM) implantation rate was significantly higher in the severe oversizing group (P = 0.03), while we observed more in-hospital congestive heart-failure (P = 0.02) in the normal sizing group. There was a trend toward more moderate to severe aortic regurgitation (AR) in the normal sizing group (P = 0.07). Conclusions Despite a higher rate of PM implantation, oversizing based on this ratio reduces aortic leak with lower rates of post-procedural complications and a similar mid-term survival. 展开更多
关键词 Aortic regurgitation Aortic valve stenosis Multislice-CT Oversizing Transcatheter aortic valve implantation
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On the policy of mainstream media to enhance public opinion's guide and influence
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作者 Ying Sang 《International Journal of Technology Management》 2013年第9期31-33,共3页
Under the new situation, news and propaganda work must hold high the banner around the overall situation, serve the people, make reform and innovation, adhere to the correct guidance of public opinion, to improve the ... Under the new situation, news and propaganda work must hold high the banner around the overall situation, serve the people, make reform and innovation, adhere to the correct guidance of public opinion, to improve the ability to guide public opinion, to create a good public opinion environment, to better play and publicize the party' s ideas, to promote social justice, to access to social conditions public opinion, to guide social hot spots, to divert the public mood, to improve the important role of public opinion. We should put the improvement of the ability to guide public opinion in a prominent position, conduct in-depth research, and come up with concrete measures to achieve new results. We must adhere to the Party' s principles; firmly grasp the correct guidance of public opinion. Guiding correctly public opinion will benefit the country, party and people; guiding media wrong will make damage to China, party and people. To firmly establish political awareness, the overall sense of responsibility, position sense, we should put adhering to the correct orientation in the first place on the news and propaganda work. 展开更多
关键词 public opinion mainstream media POLICY
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GUIDED TISSUE REGENERATION AROUND DENTAL IMPLANTS IN IMMEDIATE EXTRACTION SOCKETS:COMPARISON OF RESORBABLE ANDNONRESORBABLE MEMBRANES 被引量:5
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作者 毛驰 SatoJunichi +1 位作者 MatsuuraMasaroh SetoKanichi 《Chinese Medical Sciences Journal》 CAS CSCD 1997年第3期170-174,共5页
This study was per formed to compare the efficacy of guided tissue regeneration (GTR) around dentalimplants immediately placed into extraction sockets by resorbable of nonresorbable membranes. Mandibular. P2, P3, and ... This study was per formed to compare the efficacy of guided tissue regeneration (GTR) around dentalimplants immediately placed into extraction sockets by resorbable of nonresorbable membranes. Mandibular. P2, P3, and P4 of four aduIt beagle dogs were extracted bilaterally, and buccal standard defects were cre-ated and measured. Eighteen commercially pure titanium Steri-Oss implant fixtures were placed into thefresh extraction sockets. Four implants were untreated controls, four implants received polytetrafluoro-ethylene (e-PTFE, Gore-Tex) membranes, five implants received collagen membranes (ParaGuide), andfive implants received polyglactin 910 mesh (Vicryl). After l4 weeks, clinical measurements were takenand the dogs were sacrificed and all specimens retrieved for histologic and histomorphometric evaluation.The average gain in bone height was 2. 1mm for untreated control sites, 3. 3mm for Gore-Tex sites,3. 8mm for collagen sites, and 1. 3mm for polyglactin 910 sites. The greatest gain in bone height and volume was seen for two sites that received Gore-Tex membranes and remained covered for the entire evalua-tion interval. The results of this study indicate that Gore-Tex and collagen membrane preduced gdri re-sults for GTR around Implants immediately placed into extraction sockets. Since collagen membrane doesnot cause obvious infection and does not need the surgical reentry for membrane removal, it can be a validalternative to Gore-Tex membrane to improve bone regeneration around dental implants, while polyglactin910 mesh seems not suitable to be used as GTR membrane in immediate implantation for its hIgh infectionrate. 展开更多
关键词 guided tissue regeneration MEMBRANE dental implants
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Long non-coding RNA-guided regulation in organisms 被引量:3
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作者 QI WenChuan SONG Xu LI Ling 《Science China(Life Sciences)》 SCIE CAS 2013年第10期891-896,共6页
It is clear that RNA is more than just a messenger between gene and protein.The mammalian genome is pervasively transcribed,giving rise to tens of thousands of non-coding transcripts.Whether all of these transcripts a... It is clear that RNA is more than just a messenger between gene and protein.The mammalian genome is pervasively transcribed,giving rise to tens of thousands of non-coding transcripts.Whether all of these transcripts are functional remains to be elucidated,but it is evident that there are many functional long non-coding RNAs(lncRNAs).Recent studies have set out to decode the regulatory role and functional diversity of lncRNAs.Here we organize these studies to highlight the significant involvements of lncRNAs in regulation of gene expression and human physiological and pathological processes,which are achieved by their interaction with DNA,RNA or protein. 展开更多
关键词 lncRNAs gene expression physiological and pathological processes interaction
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