期刊文献+
共找到6,472篇文章
< 1 2 250 >
每页显示 20 50 100
上颌骨改良Le FortⅠ型截骨术的三维建模和术后咬合有限元分析
1
作者 刘楚晴 李阳 +1 位作者 毕绍洋 林阳阳 《中国医科大学学报》 北大核心 2024年第1期46-50,共5页
目的根据CT扫描数据,基于4种软件建立光顺的上颌骨三维几何模型,模拟改良Le FortⅠ型截骨术及固定方案,对患者术后咬合情况进行有限元分析。方法使用Mimics软件初步处理CT图像,建立STL模型。将模型导入Inspire Studio软件中,建立光滑的P... 目的根据CT扫描数据,基于4种软件建立光顺的上颌骨三维几何模型,模拟改良Le FortⅠ型截骨术及固定方案,对患者术后咬合情况进行有限元分析。方法使用Mimics软件初步处理CT图像,建立STL模型。将模型导入Inspire Studio软件中,建立光滑的PolyNURBS几何模型。使用SpaceClaim软件,模拟手术截骨及钛板、钛钉固定方案。使用ANSYS Workbench软件,对术后患者咬合情况进行三维有限元分析。结果仿真结果显示,在磨牙咬合状态下有限元模型的连接关系建立准确无误。在共计6 N的咬合力作用下,钛板最大等效应力为73 MPa。结论本研究采用的上颌骨建模和分析方法可获得适用于仿真分析的光滑几何模型,有限元分析结果可以为各类正颌手术的固定方案提供参考。 展开更多
关键词 上颌骨建模 有限元分析 改良le FortⅠ型截骨术 应力分布
下载PDF
Effect of Specific Verbal Instructions on the Identification of Pain Location during a Passive Straight Leg Raise Test
2
作者 Masae Ikeya Takumi Jiroumaru +2 位作者 Hitomi Bunki Noriyuki Kida Teruo Nomura 《Open Journal of Therapy and Rehabilitation》 2023年第2期45-53,共9页
Musculoskeletal pain is common. Because pain is subjective, objectively describing it is crucial. However, pain assessment may cause distress in patients;therefore, physical therapists (PTs) should conduct these tests... Musculoskeletal pain is common. Because pain is subjective, objectively describing it is crucial. However, pain assessment may cause distress in patients;therefore, physical therapists (PTs) should conduct these tests quickly and accurately. Simple and clear instructions are recommended for pain assessment. However, few studies have provided evidence to support this hypothesis. Correspondingly, this study aimed to confirm the effectiveness of specific verbal instructions for pain location during five consecutive Passive Straight Leg Raise (PSLR) tests. The 28 asymptomatic participants (age 27.4 ± 9.6 years) who provided informed consent received five consecutive PSLR tests: three without and two with specific verbal instructions to ascertain pain intensity, quality, and location. The participants drew pain locations on a body chart and described the pain intensity and quality after each test. All participants were interviewed regarding the differences they noted in the presence and absence of specific verbal instructions. Each pain location was classified into one of ten areas for statistical analysis. The proportion of participants who changed the pain location was compared between the tests using McNemar’s test, and the kappa coefficient was confirmed for consistency of pain location. There was a significant difference in the proportion of participants who changed their pain location between the second and third tests and from the third to the fourth test (McNemar’s test: p = 0.003). Kappa coefficients had low consistency (κ = 0.28) just after receiving the specific verbal instructions in the fourth test compared to the third test. Consistency improved in the fifth test (κ = 0.57);93% of the participants answered that the pain location had become clearer. This study revealed the effects of specific verbal instructions in identifying pain locations. This detailed information may help PTs provide appropriate treatment and contribute to reducing pain in clinical settings. 展开更多
关键词 Specific verbal Instructions Pain Location Pain Assessment Passive Straight leg Raise Test
下载PDF
亚临界区圆柱绕流相干结构壁面模化混合RANS/LES模型
3
作者 季梦 尤云祥 +3 位作者 韩盼盼 邱小平 马乔 吴凯健 《物理学报》 SCIE EI CAS CSCD 北大核心 2024年第5期190-216,共27页
本文发展了一种具有壁面模化大涡模拟能力的雷诺平均纳维-斯托克斯(RANS)和大涡模拟(LES)方法的混合模型(简称WM-HRL模型),致力于对亚临界区雷诺数钝体绕流相干结构这类复杂流动现象进行高置信度的CFD解析模拟研究.该方法通过一个仅与... 本文发展了一种具有壁面模化大涡模拟能力的雷诺平均纳维-斯托克斯(RANS)和大涡模拟(LES)方法的混合模型(简称WM-HRL模型),致力于对亚临界区雷诺数钝体绕流相干结构这类复杂流动现象进行高置信度的CFD解析模拟研究.该方法通过一个仅与当地网格空间分布尺寸有关的湍动能解析度指标参数rk即可实现从RANS到LES的无缝快速转换,并且RANS/LES混合转换区的边界位置及其各个分区(包括RANS区、LES区及RANS/LES混合转换区)对湍动能的解析能力均可通过两个指标参数nrk1-Q和nrk2-Q准则进行预先设定.通过对雷诺数Re=3900下圆柱绕流场的系列数值模拟研究,获得了能够高置信度解析并捕捉其绕流场中三维时空瞬态发展相干结构特性的湍动能解析度指标参数nrk1-Q和nrk2-Q准则的组合条件.研究表明,该WM-HRL模型不仅能够准确获取圆柱绕流场中剪切层小尺度K-H不稳定性结构的精细谱结构,而且在同一套网格系统下通过变化湍动能解析度指标参数nrk2-Q和nrk1-Q准则的组合条件,还可以精细解析圆柱绕流场中两类不同回流区的长度结构特征,及其对应的圆柱尾部近壁面处V和U形两个平均流向速度剖面的分支结构特性. 展开更多
关键词 圆柱绕流 相干结构 KELVIN-HELMHOLTZ不稳定性 混合RANS/leS模型
下载PDF
基于LES湍流模型的角形喷嘴数值模拟
4
作者 邓富春 王尊策 +2 位作者 刘海水 李森 岳宇航 《煤矿机械》 2024年第7期203-206,共4页
针对RANS方法存在空化流场预测不准确的问题,通过采用大涡模拟(LES)对角形喷嘴进行数值模拟来获得其瞬时速度场以及空化云分布。通过对其流场进一步分析,揭示了空化水射流在发展过程中漩涡结构与空化之间的关系以及不同压力下的射流分... 针对RANS方法存在空化流场预测不准确的问题,通过采用大涡模拟(LES)对角形喷嘴进行数值模拟来获得其瞬时速度场以及空化云分布。通过对其流场进一步分析,揭示了空化水射流在发展过程中漩涡结构与空化之间的关系以及不同压力下的射流分布特征,为工程实践应用及空化射流机理提供了理论参考。 展开更多
关键词 空化水射流 漩涡 leS 流场分析
下载PDF
基于WRF-LES模式的大气边界层近地风场精细化模拟研究
5
作者 刘达琳 陶韬 +2 位作者 曹勇 周岱 韩兆龙 《上海交通大学学报》 EI CAS CSCD 北大核心 2024年第2期220-231,共12页
台风等极端气象灾害对工程结构安全造成严重威胁,研究近地面大气边界层精细化模拟对于土木工程具有重要应用价值.数值天气预报系统(WRF)中的大涡模拟(LES)模块具有参数方案多、精度高等优点,适用于近地面风场精细化模拟,但数值天气预报... 台风等极端气象灾害对工程结构安全造成严重威胁,研究近地面大气边界层精细化模拟对于土木工程具有重要应用价值.数值天气预报系统(WRF)中的大涡模拟(LES)模块具有参数方案多、精度高等优点,适用于近地面风场精细化模拟,但数值天气预报-大涡模拟(WRF-LES)精细化模拟效果与参数设置密切相关.寻求适用于精细化模拟近地面风场的参数设置,选用WRF-LES模式中的几种次网格模型和空间差分格式,采用较细密的网格分辨率,进行理想大气边界层模拟.对比平均风速剖面、湍流强度剖面和功率谱等风场特性,讨论关键参数对近地面风场模拟精度的影响,确定合适的参数设置.研究表明:对次网格模型,非线性回波散射和各向异性(NBA1)模型可有效改善近地面风场模拟精度;对网格方案,在计算域底部不均匀加密垂直网格可更好地描述近地面风场空间分布特征,有效减小计算资源;对空间差分格式,偶数阶差分相较奇数阶差分格式可捕获更小尺度湍流结构.所提出的WRF-LES模式参数方案,可为精细化模拟近地面风场和台风边界层提供技术参考. 展开更多
关键词 次网格模型 网格分辨率 空间差分格式 数值天气预报-大涡模拟
下载PDF
Strategies for Fostering Interaction in Online Classrooms:A Conversation Analysis of Teacher-Student Verbal Interaction in Random Questioning in Pandemic-Initiated Online Teaching
6
作者 Ping Zhang 《Journal of Contemporary Educational Research》 2024年第2期98-111,共14页
This paper aims to explore how a veteran teacher organizes online teaching initiated by the pandemic and how she deals with the problems in online teacher-student verbal interaction.By analyzing a corpus of 20 audio-r... This paper aims to explore how a veteran teacher organizes online teaching initiated by the pandemic and how she deals with the problems in online teacher-student verbal interaction.By analyzing a corpus of 20 audio-recorded online lessons between a math teacher and her students during the COVID-19 pandemic from April 11 to May 10,2022,four interactional segments are selected as the focus of the study.The results of the conversation analysis of the segments showed that students’modesty,lack of confidence,lack of ability,and network delay are the main factors affecting online teacher-student interaction.By encouraging students to answer questions,enlightening students to give answers,enriching students’answers,and entertaining the teaching atmosphere(“4Es”strategies),the teacher solved the problems successfully.The findings from this study can provide pedagogical experience and implications for practical teaching. 展开更多
关键词 Online teaching Teacher-student verbal interaction Conversation analysis “4Es”strategies
下载PDF
Exploring the Relationship between Learning Styles and Proficiency in Verbal Communication
7
作者 李培隆 赵足娥 《中国校外教育(上旬)》 2008年第S1期1378-1378,1416,共2页
In the light of need to use learning styles to enhance verbal proficiency,this paper will explore the interconnectedness of learning styles and proficiency in verbal communication.It will first introduce the backgroun... In the light of need to use learning styles to enhance verbal proficiency,this paper will explore the interconnectedness of learning styles and proficiency in verbal communication.It will first introduce the background of the study.This will be followed by an overview of the research on related literature and studies in the field.Lastly the paper concludes that foreign language teachers should give attention to the styles for languages learning and verbal proficiency since they are closely correlated. 展开更多
关键词 learning STYleS PROFICIENCY verbal Communication E
下载PDF
Multimodal Discourse Analysis of College English Teacher 's Nonverbal Behaviors
8
作者 王倩 《海外英语》 2015年第14期219-220,共2页
This paper analyzes College English teacher's non-verbal behaviors in multimedia classroom from the perspective ofMultimodal Discourse Analysis, aiming to explore how the non-verbal behaviors in classroom teaching... This paper analyzes College English teacher's non-verbal behaviors in multimedia classroom from the perspective ofMultimodal Discourse Analysis, aiming to explore how the non-verbal behaviors in classroom teaching can be applied in meaning-making process to facilitate teacher-students interaction and realize three metafunctions of language in class. 展开更多
关键词 teachers’ NON-verbal BEHAVIORS MULTIMODAL discours
下载PDF
Cultivation of College Students' Ability in Cross-cultural Non-verbal Communication
9
作者 张琳琳 《海外英语》 2015年第17期247-248,共2页
For a long time,students' non-verbal communicative competence is neglected by themselves as well as the teachers.Inthis paper a research is done to analyze the causes of students' non-verbal communicative fail... For a long time,students' non-verbal communicative competence is neglected by themselves as well as the teachers.Inthis paper a research is done to analyze the causes of students' non-verbal communicative failure.And some suggestions are givento cultivate students' ability in cross-cultural non-verbal Communication The students' enhanced communicative competencewill help them avoid non-verbal communicative failure and communicate effectively and appropriately in cross-cultural communi-cation. 展开更多
关键词 NON-verbal Communication CULTURE DIFFERENCE COMMUN
下载PDF
基于RANS和LES的高大空间建筑气流组织仿真和热舒适度评价方法
10
作者 张慎 程明 +4 位作者 王义凡 孟凡凯 李霆 陈菡 戢志峰 《系统仿真学报》 CAS CSCD 北大核心 2023年第10期2212-2222,共11页
针对大空间建筑的暖通空调设计,开展气流组织分析和热舒适评价对于改善室内环境热舒适度和降低能耗具有重要意义。结合基于雷诺时均方程的稳态分析和基于大涡模拟的瞬态分析这2种计算流体力学分析方法的特点,建立了高大空间建筑气流组... 针对大空间建筑的暖通空调设计,开展气流组织分析和热舒适评价对于改善室内环境热舒适度和降低能耗具有重要意义。结合基于雷诺时均方程的稳态分析和基于大涡模拟的瞬态分析这2种计算流体力学分析方法的特点,建立了高大空间建筑气流组织仿真方案和热舒适度评价方法。利用稳态分析计算消耗较小的特点,开展多工况热舒适度和空气质量评价;选取典型工况实施计算消耗较大的瞬态分析,获取空气调节全过程,给出室内温度达到设定温度所需要的空调运行时间,从而优化空调运行策略,降低能耗。基于实验结果对2种方法的准确性进行了验证,介绍了所用方法在实际工程项目中的应用,供其他工程参考。 展开更多
关键词 雷诺时均方程 大涡模拟 高大空间建筑 气流组织 热舒适度评价
下载PDF
Atrophy of the left dorsolateral prefrontal cortex is associated with poor performance in verbal fluency in elderly poststroke women 被引量:2
11
作者 Yang-Kun Chen Wei-Min Xiao +6 位作者 Defeng Wang Lin Shi Winnie CW Chu Vincent CT Mok Ka Sing Wong Gabor S Ungvari Wai Kwong Tang 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第4期346-356,共11页
This study aimed to investigate the association between atrophy in the prefrontal cortex with executive function and verbal fluency in elderly male and female patients poststroke. Thirty elderly female patients with n... This study aimed to investigate the association between atrophy in the prefrontal cortex with executive function and verbal fluency in elderly male and female patients poststroke. Thirty elderly female patients with non-aphasic ischemic stroke aged -〉 60 years and 30 age-matched non-aphasic male patients with ischemic stroke were recruited. Automatic magnetic resonance imaging segmentation was used to assess the volume of the whole prefrontal cortex, along with its subdivisions: anterior cingulate cortex, orbitofrontal cortex and dorsolateral prefrontal cortex. The Semantic Verbal Fluency Test was administered at 3 and 15 months poststroke. At 3 months poststroke, left dorsolateral prefrontal cortex volume was significantly correlated with Verbal Fluency Test score in female patients only (partial coefficient = 0.453, P = 0.045), after controlling for age, education, diabetes, neurological deficit, white matter lesions volume, as well as the location and volume of infarcts. At 15 months poststroke, there remained a significant association between the left dorsolateral prefrontal cortex volume and Verbal Fluency Test (partial coefficient = 0.661, P = 0.001) and between the left prefrontal cortex volume and Verbal Fluency Test (partial coefficient = 0.573, P = 0.004) in female patients after the same adjustments. These findings indicate that atrophy of the left dorsolateral prefrontal cortex contributes to the impairment of verbal fluency in elderly female patients with stroke. Sex differences may be present in the neuropsychological mechanisms of verbal fluency impairment in patients with stroke. 展开更多
关键词 neural regeneration NEUROIMAGING brain atrophy verbal fluency executive function stroke sex differences prefrontal cortex dorsolateral prefrontal cortex magnetic resonance imaging grants-supported paper photographs-containing paper NEUROREGENERATION
下载PDF
Friendliness to Animals and Verbal Aggressiveness to People: Using Prison Inmates Education Networks as an Illustration 被引量:1
12
作者 Nikolaos Hasanagas Alexandra Bekiari Periklis Vasilos 《Social Networking》 2017年第3期224-238,共15页
Goal of this research is to detect possible relations between animal-related attitudes and verbal aggressiveness as well as types combining such parameters. The sample collected in 2015 contains two adult education cl... Goal of this research is to detect possible relations between animal-related attitudes and verbal aggressiveness as well as types combining such parameters. The sample collected in 2015 contains two adult education classes equivalent to secondary school level (class A = 23 inmates and B = 12 inmates, all male) at a correctional facility. Questionnaires were used. Network analysis software (Visone) and conventional statistics (SPSS) are used for calculating network variables (indegree, outdegree, katz, pageranketc) and implementing Spearman test and Principal Component Analysis. Inmates who have adopted an animal-friendly value system and are too coward to react against torture of animals, maintain a repressed emotion. If they do not intervene and provoke, then they are also not targeted by others. No reaction against torture is also connected with a deep-rooted aggressiveness. Concerning superficial aggressiveness, a profile, whose characterize is multiple verbal aggressiveness, can be attributed to repressed emotions. A type is torturing and indifferently restricts his aggressiveness, as he can satisfy his need of dominance by being aggressive towards animals. A type of inmate who loves animals and reacts against their torture, presents the most restricted and relatively smooth aggressiveness, as he discharges his repressed emotions to this reaction. Under condition of indifference, keeping pets is not evidence of loving but of a need of companionship. As for the deep-rooted aggressiveness (over-extroversion), it does not seem to be triggered by any repression. 展开更多
关键词 Animal FRIENDLINESS And CRUELTY verbal AGGRESSIVENESS INMATES Classes Social Network Analysis
下载PDF
上颌Le FortⅠ前徙术与前份根尖下截骨后退术术后软组织变化的比较研究
13
作者 李沛然 毕瑞野 +5 位作者 王旻 王瑞宇 刘尧 姜楠 曹品银 祝颂松 《国际口腔医学杂志》 CAS CSCD 2023年第3期293-301,共9页
目的测量不同上颌骨正颌术式前后鼻唇区域软组织变化,分析可能导致变化的因素。方法2017—2021年于四川大学华西口腔医院正颌及关节外科住院行正颌手术的患者37例,其中因上颌后缩行上颌骨Le FortⅠ型骨切开前徙术(LFIA)的患者18例,因上... 目的测量不同上颌骨正颌术式前后鼻唇区域软组织变化,分析可能导致变化的因素。方法2017—2021年于四川大学华西口腔医院正颌及关节外科住院行正颌手术的患者37例,其中因上颌后缩行上颌骨Le FortⅠ型骨切开前徙术(LFIA)的患者18例,因上颌前突行上颌骨前份根尖下截骨后退术(AMOS)的患者19例。收集其术前即刻和术后6~12个月的螺旋CT影像,通过Mimics和3-Matic软件进行三维重建和匹配,测量软硬组织标志点变化。使用GraphPad Prism软件进行统计学分析,显著性水平α=0.05。结果2种术式术后最主要的软组织变化均发生在上唇区域且改变方向与骨组织移动方向相同。在前后向软组织改变上,LFIA组软硬组织改变的比例为0.628,而AMOS组为0.465。颊部和鼻尖软组织在2种术式后均发生了前移,其中AMDS组中颊部软组织前移的量与软组织厚度的改变具有显著正相关性。在垂直向软组织变化上,LFIA组鼻尖点发生上抬且其距离与颌骨前徙距离具有显著正相关性,AMOS组上唇缘点发生下降且其距离与颌骨后退距离具有显著正相关性。在水平向软组织变化上,鼻翼宽度在行2种术式后均出现增宽,但在AMOS组中鼻翼宽度增宽量与后退距离呈显著负相关。结论AMOS和LFIA术后的鼻唇区域软组织改变与颌骨移动量及方向具有显著相关性。上唇前后向改变与颌骨移动距离具有显著正相关性,鼻翼宽度改变与上颌骨后退距离具有相关性。以上相关性的发现可能帮助临床医生更准确地判断鼻唇区域的软硬组织改变。 展开更多
关键词 软组织 牙颌面畸形 上颌骨le FortⅠ型骨切开术 上颌骨前份骨切开术 正颌外科
下载PDF
The Role of Non-verbal Behavior of Teachers in Providing Students Corrective Feedback and Their Consequences 被引量:3
14
作者 Emre Guvendir 《Sino-US English Teaching》 2011年第9期577-591,共15页
关键词 英语教学 教学方法 阅读教学 英语翻译
下载PDF
上颌Le Fort Ⅰ型截骨术对鼻形态影响的研究进展
15
作者 叶亨妮 陈学鹏 +2 位作者 唐贶昀 周梦琪 胡济安 《口腔医学》 CAS 2023年第11期1041-1046,共6页
上颌Le Fort Ⅰ型截骨术是正颌外科中矫治上颌骨畸形最常采用术式之一。但是,上颌骨的移动、肌肉的剥离会影响周围软组织的形态,其中鼻形态的改变越来越受到重视。已有研究报道,正颌手术后鼻形态的不利改变是降低患者手术满意度的主要... 上颌Le Fort Ⅰ型截骨术是正颌外科中矫治上颌骨畸形最常采用术式之一。但是,上颌骨的移动、肌肉的剥离会影响周围软组织的形态,其中鼻形态的改变越来越受到重视。已有研究报道,正颌手术后鼻形态的不利改变是降低患者手术满意度的主要原因之一。明确上颌Le Fort Ⅰ型截骨术对鼻形态的影响能够帮助医生更准确地预测术后鼻形态的变化,从而优化手术设计、提高医患沟通效率。本文将对上颌Le Fort Ⅰ型截骨术后鼻部形态变化的研究进展作一综述,旨在为临床实践提供相应的参考。 展开更多
关键词 le FortⅠ型截骨术 三维扫描仪 鼻形态 鼻翼基底缝合
下载PDF
上颌骨Le Fort Ⅰ型截骨术后上颌窦炎的研究现状
16
作者 王守鹏 孟箭 张雷 《中国口腔颌面外科杂志》 CAS 2023年第1期75-80,共6页
上颌窦炎是Le Fort Ⅰ型截骨术后常见的并发症,对正颌术后的骨质愈合等非常不利。明确Le Fort Ⅰ型截骨术后上颌窦炎发生的相关因素,针对性采取预防措施,早期发现与及时治疗,对于降低上颌窦炎的发生率,加快患者术后康复,以及提升患者术... 上颌窦炎是Le Fort Ⅰ型截骨术后常见的并发症,对正颌术后的骨质愈合等非常不利。明确Le Fort Ⅰ型截骨术后上颌窦炎发生的相关因素,针对性采取预防措施,早期发现与及时治疗,对于降低上颌窦炎的发生率,加快患者术后康复,以及提升患者术后生活质量具有重要意义。本文就上颌骨Le Fort Ⅰ型截骨术后并发上颌窦炎的影响、病因、诊断、治疗和预防等进行总结,为正颌外科相关医护人员早期诊治上颌窦炎提供参考。 展开更多
关键词 le FortⅠ型截骨术 上颌窦炎 术后并发症 正颌手术
下载PDF
基于WRF-LES的崇礼复杂地形局地风场模拟研究 被引量:1
17
作者 张珊 王宗敏 +1 位作者 黄刚 薛学武 《高原气象》 CSCD 北大核心 2023年第1期197-209,共13页
采用四重嵌套的WRF-LES,针对2022年北京冬奥会张家口崇礼赛区开展局地风场模拟试验,基于地面自动气象站和激光雷达观测资料,对一次晴空高压系统控制下的具有明显局地风环流特征的天气个例模拟结果进行检验评估。文中引入了STRM130 m地... 采用四重嵌套的WRF-LES,针对2022年北京冬奥会张家口崇礼赛区开展局地风场模拟试验,基于地面自动气象站和激光雷达观测资料,对一次晴空高压系统控制下的具有明显局地风环流特征的天气个例模拟结果进行检验评估。文中引入了STRM130 m地形数据、glc201527 m土地利用数据和CL‐DAS的土壤湿度数据用以提高模拟结果的准确性,并设计了敏感性试验来探讨不同资料对模拟结果的影响。结果表明:(1)WRF-LES能够呈现出复杂地形下局地风场的时空变化特征,各站风向绝对误差在10°~60°,风速绝对误差在0.5~2 m·s^(-1)。在山谷和山沟区域,模拟风场和观测风场都表现出明显的日变化特征,海拔较高站点的误差比海拔相对较低站点的误差更小。海拔较低站点在山谷风或上下坡风发展稳定时段风向误差较小,风向转换时段误差较大。(2)更新地形、土地利用以及CLDAS土壤湿度初始场对模拟结果都有一定程度改善。其中更新CLDAS土壤湿度初始场对风向和2 m气温的改善效果最为明显,风向绝对误差减小4.26°,2 m气温绝对误差减小0.84℃。更新土地利用对风速的改善效果最明显,风速绝对误差减小0.32 m·s^(-1)。(3)CLDAS土壤湿度较ERA5的土壤湿度明显偏小,较小的土壤湿度会使土壤具有低传导率或低热容量,这种状态会导致地表温度在白天的升温幅度和夜间的降温幅度都增大,较强的白天增温垂直高度可延伸至700~900 m,较强的夜间降温垂直高度在200 m以下,与此同时,较小土壤湿度也会使白天低层风速增大,这些特征在山谷和山沟中更为明显。 展开更多
关键词 WRF-leS 复杂地形 风场模拟 CLDAS土壤湿度
下载PDF
Constructing a Simple Verbal Compiler
18
作者 Ahmed Laarfi Veton Kepuska 《International Journal of Intelligence Science》 2020年第4期83-91,共9页
The paper’s purpose is to design and program the four operation-calculators that receives voice instructions and runs them as either a voice or text phase. The Calculator simulates the work of the Compiler. The paper... The paper’s purpose is to design and program the four operation-calculators that receives voice instructions and runs them as either a voice or text phase. The Calculator simulates the work of the Compiler. The paper is a practical <span style="font-family:Verdana;">example programmed to support that it is possible to construct a verbal</span><span style="font-family:Verdana;"> Compiler.</span> 展开更多
关键词 Speech Recognition Artificial Intelligence Programming Languages Compiler Construction verbal Programming
下载PDF
改良鼻旁植骨减少Le FortⅠ型截骨术后上颌骨垂直向复发的探讨
19
作者 葛卫文 祁磊 +1 位作者 王昀 张雷 《中国口腔颌面外科杂志》 CAS 2023年第2期163-167,共5页
目的:探讨改良鼻旁植骨是否能减少Le Fort 1型截骨下降手术术后上颌骨垂直向的复发。方法:选择双颌手术中上颌骨下降幅度>3 mm的患者30例,分为改良鼻旁植骨组和非改良鼻旁植骨组。利用术前(T0)、术后3天(T1)和术后6个月(T2)的颌面CT... 目的:探讨改良鼻旁植骨是否能减少Le Fort 1型截骨下降手术术后上颌骨垂直向的复发。方法:选择双颌手术中上颌骨下降幅度>3 mm的患者30例,分为改良鼻旁植骨组和非改良鼻旁植骨组。利用术前(T0)、术后3天(T1)和术后6个月(T2)的颌面CT数据对上颌骨位置进行三维测量;同时利用T1与T2的CT数据计算植骨块厚度的变化。采用SPSS 22.0软件包对数据进行统计学分析。结果:术后6个月,在垂直方向上,改良鼻旁植骨组上切牙点复发量为(0.54±0.35)mm,非改良鼻旁植骨组上切牙点复发量为(1.18±0.76)mm(P=0.3997)。2组在前后、水平方向的复发率无显著差异。改良鼻旁植骨组的植骨块厚度降低(11.75±6.25)%,非改良鼻旁植骨组的植骨块厚度降低(33.77±11.56)%(P<0.0001)。结果:改良鼻旁植骨可有效减少植骨块吸收,以及术后上颌骨垂直向复发。 展开更多
关键词 鼻旁植骨 复发 三维分析 le FortⅠ型截骨术 正颌手术
下载PDF
基于LES的螺旋桨精细流场特性分析与研究
20
作者 谢超凡 柏铁朝 +1 位作者 吴方良 张志国 《舰船科学技术》 北大核心 2023年第23期39-43,共5页
为了研究大侧斜螺旋桨的精细流场,采用有限体积法结合大涡模拟(LES)模型,对E1619螺旋桨的速度场、压力场、涡量场和湍动能场进行不同程度的分析。模拟结果表明:大涡模拟很好地捕捉了尾流涡结构,梢涡互感合并的本质是相邻的下游梢涡将上... 为了研究大侧斜螺旋桨的精细流场,采用有限体积法结合大涡模拟(LES)模型,对E1619螺旋桨的速度场、压力场、涡量场和湍动能场进行不同程度的分析。模拟结果表明:大涡模拟很好地捕捉了尾流涡结构,梢涡互感合并的本质是相邻的下游梢涡将上游梢涡推向尾流轴向速度较高的内半径区域,梢涡与相邻上游梢涡的随边涡符号相同,导致他们相互吸引;近场轮毂涡比梢涡强度更高是因为轮毂涡包含了叶根涡,且其衰减速度更快;外半径湍动能极大值在梢涡处,且梢涡的不稳定现象极大地影响了外半径湍动能的变化,内半径湍动能先减小后增大,其增大原因是梢涡失稳导致轮毂涡振荡产生湍流。 展开更多
关键词 大涡模拟 梢涡 轮毂涡 湍动能
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部