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Research on Spatial Pattern and Its Industrial Distribution of Commercial Space in Mianyang Based on POI Data 被引量:2
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作者 Da Zheng Changqi Li 《Journal of Data Analysis and Information Processing》 2020年第1期20-40,共21页
The rational layout of urban commercial space is conducive to optimizing the allocation of commercial resources in the urban interior space. Based on the commercial POI (Point of Interest) data in the central district... The rational layout of urban commercial space is conducive to optimizing the allocation of commercial resources in the urban interior space. Based on the commercial POI (Point of Interest) data in the central district of Mianyang, the characteristics of urban commercial spatial pattern under different scales are analyzed by using Kernel Density Estimation, Getis-Ord , Ripley’s K Function and Location Entropy method, and the spatial agglomeration characteristics of various industries in urban commerce are studied. The results show that: 1) The spatial distribution characteristics of commercial outlets in downtown Mianyang are remarkable, and show a multi-center distribution pattern. The hot area distribution of commercial outlets based on road grid unit is generally consistent with the identified commercial density center distribution. 2) The commercial grade scale structure has been formed in the central urban area as a whole, and the distribution of commercial network hot spots based on road grid unit is generally consistent with the identified commercial density center distribution. 3) From the perspective of commercial industry, the differentiation of urban commercial space “center-periphery” is obvious, and different industries show different spatial agglomeration modes. 4) The multi-scale spatial agglomeration of each industry is different, the spatial scale of location choice of comprehensive retail, household appliances and other industries is larger, and the scale of location choice of textile, clothing, culture and sports is small. 5) There are significant differences in specialized functional areas from the perspective of industry. Mature areas show multi-functional elements, multi-advantage industry agglomeration characteristics, and a small number of developing areas also show multi-advantage industry agglomeration characteristics. 展开更多
关键词 Point of INTEREST (POI) Commercial Space Aggregating FEATURE Industry Dis-tribution Mianyang
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Migration Laws of Floating Population in Mianyang 被引量:1
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作者 LiuPeng 《Ecological Economy》 2005年第1期49-53,共5页
Based on the overall analysis of the floating population among big and medium-sized cities in China,this paper, by means of statistics and questionnaires, makes a systematical study on the migratory features of the fl... Based on the overall analysis of the floating population among big and medium-sized cities in China,this paper, by means of statistics and questionnaires, makes a systematical study on the migratory features of the floating population in Mianyang, its employment structure, migrating causes and channels. According to the findings, the author finds a fact that with the strategy of Western Development, and with the construction of science and technology city of Mianyang, the migrating in Mianyang conforms to the general patterns of the migration, which has happened in those big and medium-sized cities in China.In addition,the city has a new but unique feature — economic factor, as the driving force of population migration, is quite distinct from that of those citiesin eastern areas of China. 展开更多
关键词 Mianyang floating population Migration Laws
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Relationship between Breakfast and Academic Performance of Primary and Middle School Students in Mianyang City
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作者 Xiao Chen Hongyu Chen +3 位作者 Linquan Gong Yonggen Fang Xiaobing Luo Dianqing Zhu 《Health》 2020年第10期1383-1389,共7页
In order to understand the relationship between breakfast frequency and academic performance of grade 5 and grade 8 students, we conducted an investigation through a multistage cluster sampling design with 16,840 stud... In order to understand the relationship between breakfast frequency and academic performance of grade 5 and grade 8 students, we conducted an investigation through a multistage cluster sampling design with 16,840 students (8017 5th graders and 8823 8th graders) from Mianyang city. Results show that: 1) 71.3% of fifth graders and 59.7% of eighth graders had breakfast every day of the week, and 9.7% of fifth graders and 7.5% of eighth graders had breakfast three times or less per week. 2) The number of times students eat breakfast per week has a significant impact on their comprehensive academic performance, which is reflected in the trend that the more times students eat breakfast, the better their overall academic performance is. Based on this, in order to help students eat breakfast more often, and further improve students’ academic performance, we will strengthen the publicity and education of students’ breakfast knowledge from multiple perspectives. 展开更多
关键词 Breakfast Frequency Academic Performance STUDENTS Mianyang City
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The Developing Thought of “Tourist Agriculture” in Suburb of Mianyang——Lessons from Taiwan Province of China
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作者 CaiShuhua ChenChaozheng 《Ecological Economy》 2005年第1期27-29,共3页
Tourist agriculture, based on agriculture,is a new cross combination of agriculture and tourism from 1970s.Ithas appeared some original features by now, and weshould use the successful experience of the tourist agricu... Tourist agriculture, based on agriculture,is a new cross combination of agriculture and tourism from 1970s.Ithas appeared some original features by now, and weshould use the successful experience of the tourist agriculture in Taiwan of China for reference to standardize all the aspects of work.Support it more in policy,fund, technology, and propaganda, and strengthen the combination of the program of city and suburb to promote the development of the tourist agriculture in Mianyang. 展开更多
关键词 Tourist agriculture developing thought suburbin Mianyang
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Primary Analysis for the Establishment of Ecological City of Mianyang
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作者 ZhangXinhe 《Ecological Economy》 2005年第1期23-26,共4页
This paper probes into the establishment of ecological city of Mianyang and directive thoughts,measures, and countermoves are put forward based on analyzing the current situation about ecological environment of Mianya... This paper probes into the establishment of ecological city of Mianyang and directive thoughts,measures, and countermoves are put forward based on analyzing the current situation about ecological environment of MianyangCity. 展开更多
关键词 ecologicalcity ecological economy Mianyang City
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Research on Thermal Comfort of Outdoor Space in Summer Urban Park: Take Mianyang Urban Park as an Example 被引量:1
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作者 Bin Cheng Rongzhou Cheng Xinyu Tang 《Journal of Building Construction and Planning Research》 2020年第3期161-179,共19页
One of the factors for the evaluation of the space environment is the comfort of outdoor activities spaces in urban parks. The space composed of different landscape elements has different microclimate environment. In ... One of the factors for the evaluation of the space environment is the comfort of outdoor activities spaces in urban parks. The space composed of different landscape elements has different microclimate environment. In this paper, in order to evaluate the role of thermal comfort in influencing resident’s assessment of the outdoor space and activities of the park, a thermal comfort survey was conducted on the outdoor open space of Mianyang Urban Park in summer. In this article, meteorological surveys, questionnaire surveys and observation of park attendance are selected to collect data. The physiological equivalent temperature (PET) assessment was selected as the index to evaluate resident’s thermal comfort level, and the comprehensive evaluation and analysis of the spatial thermal environment of different outdoor landscape elements in the park. The overall comfort of current visitors is mainly influenced by their subjective heat perception voting (TSV). In this article, we focus on providing microclimate adjustment considerations for urban park landscape design, and may help people understand the outdoor thermal comfort of Mianyang in summer, increase the using time of outdoor activities, and promote the use of outdoor space. 展开更多
关键词 Thermal Comfort Outdoor Activities Space Physiological Equivalent Temperature Landscape Elements
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Research on the Spatial Database Construction of Three-line Industrial Heritage Based on “One Map” of Territorial Space Planning —A Case Study of Mianyang Two-Bomb City
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作者 Wandi Huang Mingming Xiang 《World Journal of Engineering and Technology》 2022年第4期895-906,共12页
In the process of promoting the national territorial spatial planning system in all provinces, cities and counties, the geospatial database of “One Map” has realized the information sharing and collaborative work of... In the process of promoting the national territorial spatial planning system in all provinces, cities and counties, the geospatial database of “One Map” has realized the information sharing and collaborative work of multiple departments. Based on this, this paper intended to provide a set of standardized mapping models for industrial heritage storage, and through the establishment of the database to protect and reuse the status quo of industrial heritage research. This paper took the third-line construction industrial heritage of Mianyang “Two-Bomb City” as the research object, developed the relevant drawing standards of third-line industrial heritage database, and studied the database construction process. GIS technology is used to establish a geospatial database of the third-line industrial heritage in cooperation with the “One Map” system, in order to provide reference for the storage of the third-line industrial heritage in various places, and to protect and reuse the third-line industrial heritage from the perspectives of spatial factors, planning coordination and dynamic assessment. 展开更多
关键词 Third-Line Construction of Industrial Heritage GIS Geospatial Database
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Epidemiological Characteristics and Genotypes of Human Papillomavirus Infection in Mianyang
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作者 Daping Song Min Min +1 位作者 Pingjing Guo Xuemei Zhou 《Proceedings of Anticancer Research》 2021年第6期61-67,共7页
Objective:To investigate the epidemiological characteristics and genotypes of human papillomavirus(HPV)infection in Mianyang.Methods:The cervical samples of 27,040 patients,who visited the Department of Gynecology of ... Objective:To investigate the epidemiological characteristics and genotypes of human papillomavirus(HPV)infection in Mianyang.Methods:The cervical samples of 27,040 patients,who visited the Department of Gynecology of The Third Hospital of Mianyang from January 2018 to January 2020,were collected.Results:The HPV-positive infection rate was 21.40%(5,787/27,040);the single HPV infection rate was 72.04%(4,169/5,787);the double HPV infection rate was 19.73%(1,142/5,787);the triple and above HPV infection rate was 8.22%(476/5,787);the top five high-risk HPV subtypes with the highest infection rates were HPV52,16,58,53,and 51,while the top five low-risk HPV subtypes with the highest infection rates were HPV81,42,43,6,and 11;there were significant differences in the HPV-positive infection rate,high-risk infection rate,low-risk infection rate,and multiple infection rate among different age groups(P<0.05).Conclusion:The HPV infection rate in Mianyang was 21.4%,in which the majority of the cases were single infection;the high-risk HPV subtypes were HPV52,16,58,53,and 51;the HPV-positive infection rate,high-risk infection rate,low-risk infection rate,and multiple infection rate were high in the middle but low at both ends in the context of age distribution;the top three age groups with the highest infection rates were 45-49,40-44,and 30-34. 展开更多
关键词 HPV EPIDEMIOLOGY Gene subtype Age
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转臂式高速离心机减阻设计及机室流场特性研究
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作者 陈红永 杨鑫 +4 位作者 黎启胜 龚志斌 宋琼 李心耀 尹益辉 《应用力学学报》 北大核心 2026年第1期164-170,共7页
风阻功率是大型转臂式土工离心机驱动功率设计的重要依据,机室流场具有随流、温升、流速高等特点。为降低风阻需对转臂或吊篮采取整流减阻设计。针对两型分别采用转臂整流和整流罩减阻的离心机,开展了基于CFD(computational fluid dynam... 风阻功率是大型转臂式土工离心机驱动功率设计的重要依据,机室流场具有随流、温升、流速高等特点。为降低风阻需对转臂或吊篮采取整流减阻设计。针对两型分别采用转臂整流和整流罩减阻的离心机,开展了基于CFD(computational fluid dynamics)的气动特性仿真,通过优化仿真参数获得离心机高速运行时的机室内部流场流场特性及离心机风阻功率,并通过型线设计对离心机整流罩进行了气动阻力系数优化。研究表明:高速离心机低气压运行时机室下壁面的摩擦阻力矩占主导,高于周向壁面的摩擦阻力矩;吊篮不采用整流罩时,在迎风端面肩部出现了流动分离,压差阻力较大;采用整流罩后,吊篮前缘肩部的分离被削弱,总阻力系数大幅降低。研究表明对于高速离心机开展整流设计是必要的,通过转臂外形设计及整流罩设计,可有效降低风阻功率,更有益于控制机室温升。 展开更多
关键词 转臂式离心机 高速转动 流场 CFD 整流罩
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一种新型高压电子束焊机偏压电源设计
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作者 李波 赵娟 +3 位作者 李洪涛 康传会 李松杰 马勋 《强激光与粒子束》 北大核心 2026年第2期116-122,共7页
偏压电源是高压电子束焊机电源系统的重要部件之一,根据电子束焊机电源系统的技术要求,研制了一套输出直流电压-100 V~-2 kV可调,全电压范围内纹波小于等于0.1%,电压稳定性优于0.1%,输出电流大于3 mA的偏压电源,分别给出了该电源在电阻... 偏压电源是高压电子束焊机电源系统的重要部件之一,根据电子束焊机电源系统的技术要求,研制了一套输出直流电压-100 V~-2 kV可调,全电压范围内纹波小于等于0.1%,电压稳定性优于0.1%,输出电流大于3 mA的偏压电源,分别给出了该电源在电阻负载和高压电子枪负载下的实验结果。设计上采用吸收、保护等方法,解决了电子枪负载打火损坏偏压电源问题,成功将偏压电源串接在高压电源回路中,通过回采偏压电源回路中工作电流的大小来改变偏压电源输出电压(偏压杯电压),偏压杯电压根据束流大小进行自适应调节,实现了工作束流实时快速跟随和精细调控。成功应用于-150 kV/33 mA高压电子束焊机,使高压电子束焊机的束流纹波达到±0.19%,束流稳定性优于±5μA、束流可重现性达到±0.04%,满足了总体指标要求。 展开更多
关键词 偏压电源 电压自适应调节 束流稳定性 束流重复性
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国产ECRH 175 GHz兆瓦回旋管实现500 kW/100 s长脉冲输出
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作者 胡林林 黄麒力 +11 位作者 胡鹏 卓婷婷 龚胜刚 刘皓中 向永飞 姚徐 郭俊 蒋艺 张鲁奇 孙迪敏 马国武 马弘舸 《强激光与粒子束》 北大核心 2026年第1期41-43,共3页
报道了面向磁约束聚变电子回旋共振加热(ECRH)应用的175 GHz长脉冲回旋管的最新实验进展。该回旋管输出窗采用了金刚石窗,电子枪采用双阳极磁控注入枪,谐振腔工作模式为TE_(28,11),收集极采用了单极降压和纵向扫描线圈。通过实验调试和... 报道了面向磁约束聚变电子回旋共振加热(ECRH)应用的175 GHz长脉冲回旋管的最新实验进展。该回旋管输出窗采用了金刚石窗,电子枪采用双阳极磁控注入枪,谐振腔工作模式为TE_(28,11),收集极采用了单极降压和纵向扫描线圈。通过实验调试和长时间老炼,该回旋管实现了输出功率500 kW、连续工作100 s的实验结果,总效率达到为46%。这是国内首次在ECRH回旋管研究中实现百千瓦级100 s长脉冲输出。 展开更多
关键词 回旋管 兆瓦 电子回旋共振加热 磁约束聚变
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孔洞缺陷对α-Fe拉伸变形行为影响的分子动力学模拟
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作者 李翔 尹益辉 +2 位作者 张元章 李继承 李洪祥 《稀有金属材料与工程》 北大核心 2026年第2期510-516,共7页
为深入研究孔洞缺陷对α-Fe试样拉伸变形行为的影响,构建含不同大小孔洞缺陷的α-Fe试样计算模型,并进行单轴拉伸应变下的分子动力学模拟。结果表明:整体趋势上,含孔洞缺陷试样的拉伸力学性能损减与孔洞尺寸正相关,孔洞尺寸越大,试样越... 为深入研究孔洞缺陷对α-Fe试样拉伸变形行为的影响,构建含不同大小孔洞缺陷的α-Fe试样计算模型,并进行单轴拉伸应变下的分子动力学模拟。结果表明:整体趋势上,含孔洞缺陷试样的拉伸力学性能损减与孔洞尺寸正相关,孔洞尺寸越大,试样越容易进入塑性变形阶段;含孔洞缺陷试样的杨氏模量、屈服应力、极限强度和拉断延伸率均随着孔洞半径的增大而减小;试样的塑性变形表现为拉伸应力诱发的相变和位错滑移混合的机制;随着孔洞半径的增大,试样的应力-应变曲线特征发生显著变化——试样的塑性屈服段和应变硬化段越来越短,应变硬化段甚至消失。研究有助于深入认识孔洞缺陷对金属变形机制的影响,为后续开展多晶α-Fe材料的物理和力学性质的分析研究奠定有益基础。 展开更多
关键词 Α-FE 孔洞 相变 位错滑移
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双波长全光纤激光干涉速度复测技术
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作者 王为 刘盛刚 +4 位作者 谷伟 陶天炯 马鹤立 王翔 翁继东 《高压物理学报》 北大核心 2026年第3期31-37,共7页
针对冲击爆轰实验中对速度测量系统的高可靠性要求,基于光纤波分复用/解复用技术,提出了一种双波长全光纤激光干涉速度复测方法及技术。设计并搭建了一套速度复测原理验证系统,采用1530.3和1550.0 nm 2个波长,在气体炮上开展了低速、高... 针对冲击爆轰实验中对速度测量系统的高可靠性要求,基于光纤波分复用/解复用技术,提出了一种双波长全光纤激光干涉速度复测方法及技术。设计并搭建了一套速度复测原理验证系统,采用1530.3和1550.0 nm 2个波长,在气体炮上开展了低速、高速2种典型状态下的动态验证实验。实验结果显示,利用单一光纤探头实现了样品自由面运动速度的复测,2个波长系统得到的速度测量结果具有较好的一致性,速度相对偏差在±1.5%以内。 展开更多
关键词 激光干涉 多普勒测速 波分复用 速度复测
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高温Taylor撞击实验技术及其在金属材料本构模型验证中的应用
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作者 陈军红 尹标 +4 位作者 张胜德 胡文军 张方举 谢若泽 徐伟芳 《力学学报》 北大核心 2026年第2期486-496,共11页
高温Taylor撞击实验为应变率和温度相关的材料本构模型验证和参数优化提供了新方法.基于空气炮装置,突破了实验件速度实现与控制、实验件高温实现与装置设计、高温实验件冲击动力学响应量测试三项关键技术,建立了高温Taylor撞击实验技术... 高温Taylor撞击实验为应变率和温度相关的材料本构模型验证和参数优化提供了新方法.基于空气炮装置,突破了实验件速度实现与控制、实验件高温实现与装置设计、高温实验件冲击动力学响应量测试三项关键技术,建立了高温Taylor撞击实验技术,并将其应用于05Cr17Ni4Cu4Nb钢本构模型参数验证与优化中.首先,对05Cr17Ni4Cu4Nb钢进行了室温~900℃以及1.0×10^(-3)~1.0×10^(3) s^(-1)应变率下的拉伸实验,获得了不同温度和应变率下的应力应变曲线.基于参考应变率下材料流动应力随塑性应变变化、屈服强度随应变率变化以及屈服强度随温度变化规律,拟合得到了05Cr17Ni4Cu4Nb钢应变率和温度相关的Johnson-Cook本构模型参数.其次,利用高温Taylor撞击实验技术对05Cr17Ni4Cu4Nb钢进行了室温,300,500,570和710°C下的Taylor撞击实验,获取了不同温度下撞击后实验件外形尺寸.开展了05Cr17Ni4Cu4Nb钢室温及高温Taylor撞击有限元数值模拟分析,建立了本构模型参数优化流程和优化算法,以实验件尺寸平均偏差作为优化目标函数,开展了05Cr17Ni4Cu4Nb钢本构模型参数优化,获取了优化后的Johnson-Cook本构模型参数.优化结果表明:由单轴应力状态获取的Johnson-Cook本构模型参数过高地描述了05Cr17Ni4Cu4Nb钢在复杂应力状态下的应变硬化行为、应变率硬化行为和温度软化行为. 展开更多
关键词 高温 高应变率 TAYLOR 撞击 本构模型 参数优化
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火箭倒飞逆向喷流干扰特性数值模拟研究
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作者 张培红 贾洪印 +3 位作者 赵娇 吴晓军 周桂宇 张耀冰 《北京航空航天大学学报》 北大核心 2026年第1期120-128,共9页
有动力垂直回收是实现运载火箭可重复使用的关键技术之一。垂直回收过程中,火箭倒飞产生的大分离非规则流动,以及发动机逆向喷流与主流相互作用导致的复杂气动干扰,对数值模拟方法提出了严峻挑战。基于NNW-FlowStar软件和非结构混合网... 有动力垂直回收是实现运载火箭可重复使用的关键技术之一。垂直回收过程中,火箭倒飞产生的大分离非规则流动,以及发动机逆向喷流与主流相互作用导致的复杂气动干扰,对数值模拟方法提出了严峻挑战。基于NNW-FlowStar软件和非结构混合网格技术,采用球头逆向喷流标模,以及自主开展的火箭倒飞逆向喷流风洞试验标模,对数值模拟方法进行了验证,研究不同双喷喷流状态对火箭倒飞逆向喷流干扰特性的影响。结果表明:NNW-FlowStar软件可以较好模拟火箭倒飞逆向喷流干扰特性,数值模拟结果与试验结果吻合较好,计算得到的流场结构与风洞试验一致;不同组合喷流形式呈现出不同的喷流干扰特性和流场结构,不同喷流方案轴向力差异明显,对力矩特性影响也较大,甚至会导致全箭本体的纵向静稳定性发生变化,在超声速来流状态采用双喷状态2即2个水平喷管的方案减速效果较好。 展开更多
关键词 火箭倒飞 逆向喷流 干扰特性 NNW-FlowStar 数值模拟
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基于微纳结构靶的强场激光辐射源发展和展望
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作者 杨月 温家星 +11 位作者 王少义 吴思辛 于明海 叶翰晟 张天奎 储根柏 邓志刚 周凯南 陈忠靖 吴玉迟 周维民 赵宗清 《强激光与粒子束》 北大核心 2026年第2期1-16,共16页
微纳结构靶具有从激光焦斑尺度至亚波长尺度的周期或非周期性结构,能够有效调控激光-靶相互作用过程中的能量传递、电磁场分布、粒子输运与辐射产生过程,是创造高能量密度物质状态、提高激光辐射源能量与亮度的重要技术途径。本文将针... 微纳结构靶具有从激光焦斑尺度至亚波长尺度的周期或非周期性结构,能够有效调控激光-靶相互作用过程中的能量传递、电磁场分布、粒子输运与辐射产生过程,是创造高能量密度物质状态、提高激光辐射源能量与亮度的重要技术途径。本文将针对超短超强激光和微纳结构靶相互作用的物理机理、研究方法和发展趋势,详细介绍基于微纳结构靶的强场激光辐射源研究进展,包括迄今已经趋于实用的基于数十太瓦至百太瓦激光装置产生的强流粒子束及射线源,以及当前理论研究热点—量子电动力学辐射、高次谐波等新型光源等,最后对基于微纳结构靶的辐射源技术发展需求和研究趋势进行展望。 展开更多
关键词 微纳结构靶 激光加速 超热电子 强辐射源
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粉末热轧9Cr-ODS钢三维组织及力学性能研究
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作者 邹东利 崔书山 +2 位作者 何立峰 陈长安 张胜 《钢铁研究学报》 北大核心 2026年第1期122-132,共11页
先进核能系统的发展,对其核心结构材料提出了更高要求。本文在粉末冶金制备基础上,结合热轧与热处理工艺,制备了高性能9Cr-ODS钢板材,系统研究了板材的三维显微组织及力学性能。结果表明,9Cr-ODS钢三维显微组织具有典型的轧制态特征,轧... 先进核能系统的发展,对其核心结构材料提出了更高要求。本文在粉末冶金制备基础上,结合热轧与热处理工艺,制备了高性能9Cr-ODS钢板材,系统研究了板材的三维显微组织及力学性能。结果表明,9Cr-ODS钢三维显微组织具有典型的轧制态特征,轧向-横向轧制表面由等轴状晶粒组成,横向-法向、轧向-法向面由严重变形拉长的晶粒组成,长径比大于10。9Cr-ODS钢中存在Cr元素分布不均匀的现象,同时存在一定密度的位错结构以及弥散分布的球状强化相。9Cr-ODS钢力学性能具有一定的不均匀性,标准大样品之间差异较小,而板状小样品力学性能与取样位置密切相关,特别是断后伸长率,最大差别可达30%以上。9Cr-ODS钢以沿晶和穿晶断裂为主,拉伸过程发生明显的缩颈行为,断口形貌为层叠纤维状,片层之间的间距约3~5μm。 展开更多
关键词 9Cr-ODS钢 三维显微组织 力学性能 粉末热轧 热处理
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一种表面热流辨识结果的不确定度分析方法
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作者 周宇 邵元培 +1 位作者 钱炜祺 郑凤麒 《实验流体力学》 北大核心 2026年第1期127-134,共8页
利用热防护层内部温度时序数据辨识表面热流,是获取高速飞行器表面热环境的重要手段。分析及量化辨识结果的不确定度,可为试验数据有效性提供量化标准,支撑热环境“极端工况”安全评估。表面热流辨识是一种典型的不适定问题,测量噪声中... 利用热防护层内部温度时序数据辨识表面热流,是获取高速飞行器表面热环境的重要手段。分析及量化辨识结果的不确定度,可为试验数据有效性提供量化标准,支撑热环境“极端工况”安全评估。表面热流辨识是一种典型的不适定问题,测量噪声中的高频成分会破坏解的稳定性,需要通过正则化获得稳定解。虽然正则化降低了估计结果的不确定性,但给不确定度分析制造了障碍。为此,将正则化看作低通滤波器,将辨识结果转换到频域来分析辨识结果的不确定度。最后,以典型飞行器温度测量组件的表面热流辨识为例,分析了不确定度来源,并利用蒙特卡洛方法验证了不确定度分析方法的有效性。 展开更多
关键词 表面热流 辨识 不适定性 正则化 不确定度 低通滤波器
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U-2Nb合金试样尺寸对拉伸性能的影响
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作者 何兴会 李鱼飞 +2 位作者 陈冬 任志勇 崔书山 《金属热处理》 北大核心 2026年第1期65-70,共6页
U-2Nb合金拉伸性能的可靠性取决于晶粒尺寸和样品尺寸的匹配程度。采用铸造+均匀化热处理获得平均晶粒尺寸在1 mm左右的大晶粒合金,再经冷旋和再结晶热处理后获得平均晶粒尺寸约122μm的小晶粒合金,大晶粒合金制备了Ф5 mm棒状和厚0.75... U-2Nb合金拉伸性能的可靠性取决于晶粒尺寸和样品尺寸的匹配程度。采用铸造+均匀化热处理获得平均晶粒尺寸在1 mm左右的大晶粒合金,再经冷旋和再结晶热处理后获得平均晶粒尺寸约122μm的小晶粒合金,大晶粒合金制备了Ф5 mm棒状和厚0.75、1.5 mm板状拉伸试样,小晶粒合金制备了Ф4 mm棒状和厚0.75、1.5 mm板状拉伸试样,研究了试样尺寸对合金拉伸性能的影响。结果表明,这4种规格拉伸试样的断口都具有准解理开裂特征,试样截面包含的晶粒数目多,断裂截面越平整,韧窝所占比例越大。拉伸试样尺寸主要影响抗拉强度、断裂总延伸率和断面收缩率。减小晶粒尺寸有利于降低不同尺寸拉伸试样之间力学性能指标的差异。为了在省料的前提下准确表示U-Nb合金的力学性能,对于大晶粒U-2Nb合金,推荐采用Ф5mm的棒状拉伸试样,此时屈服强度为511.7 MPa,抗拉强度为1047.0 MPa,断裂总延伸率为17.8%。对于小晶粒U-2Nb合金,推荐采用厚1.5 mm的板状拉伸试样,此时屈服强度为588.7 MPa,抗拉强度为1070.3 MPa,断裂总延伸率为23.7%。 展开更多
关键词 U-2Nb合金 样品尺寸 晶粒尺寸 拉伸性能 断口形貌
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