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Partial wave scattering cross sections for He-HBr collision 被引量:7
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作者 余春日 凤尔银 +1 位作者 汪荣凯 杨向东 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第11期2571-2577,共7页
A new anisotropic potential is fitted to ab initio data. The close-coupling approach is utilized to calculate state-tostate rotational excitation partial wave cross sections for elastic and inelastic collisions of He ... A new anisotropic potential is fitted to ab initio data. The close-coupling approach is utilized to calculate state-tostate rotational excitation partial wave cross sections for elastic and inelastic collisions of He atom with HBr molecule based on the fitted potential. The calculation is performed separately at the incident energies: 75, 100 and 200 meV.The tendency of the elastic and inelastic rotational excitation partial wave cross sections varying with total angular quantum number J is obtained. 展开更多
关键词 close-coupling approach partial wave cross sections He-BrH complex
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The effect of the attractive well of the potential energy surface for Ne-HC1 on rotationally inelastic partial wave cross sections 被引量:1
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作者 余春日 史守华 +1 位作者 汪荣凯 杨向东 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第11期3345-3351,共7页
An interaction potential of the Ne-HC1 van der Waals complex is obtained by utilizing the Huxley analytic potential function to fit the accurate interaction energy data, which have been computed at the coupled cluster... An interaction potential of the Ne-HC1 van der Waals complex is obtained by utilizing the Huxley analytic potential function to fit the accurate interaction energy data, which have been computed at the coupled cluster singles and doubles including connected triple excitations level and with the augmented correlation consistent polarized valence quintuple zeta basis set extended with a set of 3s3p2dlflg mid-bond functions [CCSD (T)/aug-cc-pV5Z-33211]. The close coupling calculation of state-to-state partial cross sections for collision of Ne with HC1 is first performed by employing the fitted interaction potential. This calculation is performed at the incident energies: 40, 60, 75 and 100 meV, separately. The effects of the long-range attractive and the short-range anisotropic interactions on the inelastic state-to-state partial cross sections are discussed in detail. Two maxima are present in the rotationally inelastic partial cross sections and they originate from different mechanisms. 展开更多
关键词 potential energy surface inelastic partial wave cross sections close-coupling approach Ne-HC1 complex
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Close coupling calculations for excitation partial cross sections in Ne-HF collisions
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作者 余春日 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第6期2097-2102,共6页
This paper reports that an exact quantum close coupling calculation is carried out for rotational excitation in Ne HF collisions on the available anisotropic potential. Partial cross sections are obtained separately a... This paper reports that an exact quantum close coupling calculation is carried out for rotational excitation in Ne HF collisions on the available anisotropic potential. Partial cross sections are obtained separately at the incident energies of 48.35, 75, 120 and 150meV. The reliability of the results is demonstrated by comparison with previously published theoretical findings. Based on the calculations, the effect of the potential energy surface on the excitation partial cross sections is discussed in detail. 展开更多
关键词 close coupling calculation excitation partial cross section Ne HF collision
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Influence of Isotope Substitution Helium Atom on Partial Cross Sections in He-HF Collisions
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作者 YU Chun-Ri ZHANG Jie CHEN Li JIANG Gui-Sheng HUANG Guo-Dong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第11期924-928,共5页
Close-coupling equation and anisotropic potential developed in our previous research are applied to HE-SHe (4He, 6He, 8He,10He) collision system, and partial cross sections (PCSs) at the incident energy of 40 me V... Close-coupling equation and anisotropic potential developed in our previous research are applied to HE-SHe (4He, 6He, 8He,10He) collision system, and partial cross sections (PCSs) at the incident energy of 40 me V are calculated. By analyzing the differences of these PCSs, change rules of PCSs with the increase of partial wave number, and with the change of the mass of isotope substitution helium atom are obtained. The results show that excitation PCSs converge faster than elastic PCSs for collision energy and each of systems considered here. Also excitation PCSs converge more rapidly for high-excited states. Tail effect is present only in elastic scattering and low-excited states but not in high- excited states. With the increase of the mass of isotope substitution helium atom, converging speed of elastic, total inelastic, and state-to-state excitation PCS slows down, and the maxima of these PCSs undergoes a regular change. 展开更多
关键词 isotope substitution partial cross section close-coupling equation He-HF collision
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MAGNETOHYDRODYNAMIC PIPE FLOW IN DUCTS WITH PARTIAL CIRCULAR RING CROSS SECTION AND ANNULAR CROSS SECTION
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作者 Shu Yousheng, Department of Physics, Peking University, Beijing, ChinaQian Shangwu, Center of Theoretical Physics, CCAST (World Lab. ), Beijing Institute of Theoretical Physics, Academia Sinica, Beijing Department of Physics, Peking University, Beijing, China 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 1990年第1期85-91,共7页
In this paper we use the Green function method to solve the problem of steady one dimensional flow of an incompressible viscous, electrically conducting fluid through a pipe with partial circular ring cross sec- tion ... In this paper we use the Green function method to solve the problem of steady one dimensional flow of an incompressible viscous, electrically conducting fluid through a pipe with partial circular ring cross sec- tion and one with annular cross section, in the presence of an applied transverse uniform magnetic field, We ob- tain analytic solutions and carry out some numerical calculations of the velocity distribution and induced magnet- ic field. 展开更多
关键词 magnetohydrodynamic pipe flow Green function method partial circular ring cross section annular cross section
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工艺孔对大截面部分包覆钢-混凝土组合梁受弯性能影响的试验研究 被引量:1
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作者 贾水钟 刘宏欣 +3 位作者 李亚明 孙求知 张朕磊 钱桦 《建筑结构》 北大核心 2024年第4期9-17,共9页
为了研究工艺孔对大截面部分包覆钢-混凝土组合梁(大截面PEC梁)受弯性能的影响,对5根不同构造的大截面PEC梁进行了静力试验,研究了两点加载下主次梁腹板开洞方式对大截面PEC梁试件受弯性能、延性、破坏模式等的影响规律。结果表明:静力... 为了研究工艺孔对大截面部分包覆钢-混凝土组合梁(大截面PEC梁)受弯性能的影响,对5根不同构造的大截面PEC梁进行了静力试验,研究了两点加载下主次梁腹板开洞方式对大截面PEC梁试件受弯性能、延性、破坏模式等的影响规律。结果表明:静力荷载作用下,各个试件均表现出良好的延性,腹部开孔对试件承载力和截面刚度有一定的削弱作用。型钢主钢件的应变与混凝土的应变沿截面高度方向均大致呈线性变化,符合平截面假定。按《部分包覆钢-混凝土组合结构技术规程》(T/CECS 719—2020)计算得到的开工艺孔的大截面PEC梁抗弯承载力与试验值误差较小,受尺寸效应影响不大,所采用计算公式安全可靠。 展开更多
关键词 大截面部分包覆钢-混凝土组合梁 工艺孔 破坏模式 受弯承载力 延性
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基于局部剖视图的UG软件应用技巧
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作者 罗若 肖振泉 《内燃机与配件》 2024年第5期104-107,共4页
本文介绍了利用UG软件创建二维、立体局部剖视图的方法,研究总结了几何体创建具有相同剖切分界线的二维、立体局部剖视图的应用技巧和符合国家标准的局部剖视图表达方法。局部剖视图相同剖切分界线的创建,分界线在二维、立体视图中的切... 本文介绍了利用UG软件创建二维、立体局部剖视图的方法,研究总结了几何体创建具有相同剖切分界线的二维、立体局部剖视图的应用技巧和符合国家标准的局部剖视图表达方法。局部剖视图相同剖切分界线的创建,分界线在二维、立体视图中的切换,是整个过程比较关键的操作,关系到视图能否创建成功。通过本文介绍的方法,绘图者可以轻松实现正交的局部剖、轴测局部剖视图的绘制,熟练掌握后可以大大提高绘图的工作效率,为绘图工作提供方便。 展开更多
关键词 机械制图 UG软件 局部剖视图
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基于倾斜关联筛选的船舶分区消磁绕组部署及消磁电流优化策略
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作者 田野 余墨多 +2 位作者 黄文焘 邰能灵 牛璐 《上海交通大学学报》 EI CAS CSCD 北大核心 2024年第7期1018-1026,共9页
在现代舰船消磁系统中,消磁绕组主要基于舰船舱壁的形状进行分布,难以保证每个消磁绕组的消磁效果.为解决这一问题,引入一种高维变量筛选中的倾斜关联筛选方法,选择合适的阈值,将原有绕组进行拆分重组,对原有消磁区段进行重新划分,进而... 在现代舰船消磁系统中,消磁绕组主要基于舰船舱壁的形状进行分布,难以保证每个消磁绕组的消磁效果.为解决这一问题,引入一种高维变量筛选中的倾斜关联筛选方法,选择合适的阈值,将原有绕组进行拆分重组,对原有消磁区段进行重新划分,进而改善每个绕组的单位绕组磁感应强度.针对绕组重组后消磁电流计算时存在的参数向量稀疏和多重共线的问题,提出了倾斜关联筛选-部分岭回归算法,通过仿真可知,在阈值为0.73和0.91时,该算法相较最小二乘法消磁误差最大幅值分别减小了10.08%和17.59%,而剩余均方根误差分别减小了10.45%和12.17%.根据仿真结果可知,采用该算法后消磁效果得到明显提升. 展开更多
关键词 船舶消磁 倾斜关联筛选 最小二乘法 部分岭回归 区段划分
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部分断面煤矿掘进机纠偏系统设计与应用研究
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作者 卢春锋 《能源与节能》 2024年第7期208-210,214,共4页
以EBZ-160型掘进机为例,介绍一种部分断面煤矿掘进机纠偏系统设计方案。该纠偏系统主要由液压缸、液压泵、发电机、液压阀、压力传感器与位移传感器构成,通过对掘进机位移方向的监测,判断掘进机位移方向是否符合要求,并根据监测结果对... 以EBZ-160型掘进机为例,介绍一种部分断面煤矿掘进机纠偏系统设计方案。该纠偏系统主要由液压缸、液压泵、发电机、液压阀、压力传感器与位移传感器构成,通过对掘进机位移方向的监测,判断掘进机位移方向是否符合要求,并根据监测结果对掘进机掘进方向予以调节,确保掘进机按照预期方向逐渐掘进。由应用分析可知,通过该纠偏系统的应用,可显著提升部分断面煤矿掘进机掘进的精确性,有利于提高煤矿开采效率,确认该纠偏系统具有一定应用价值。 展开更多
关键词 部分断面煤矿 掘进机 纠偏系统
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连铸机扇形段用调心滚子轴承失效分析
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作者 董玉柱 郭宏军 +5 位作者 许荣昌 夏佃秀 孙宗辉 田盛林 吴赛赛 杨旭 《科学技术创新》 2024年第7期225-228,共4页
本文采用了光学显微镜、扫描电子显微镜及硬度仪等设备,对失效的连铸机扇形段调心滚子轴承进行了分析,以探求其失效的原因。结果表明:轴承安装时存在一定的偏载,随着轴承的不断运转,偏载会越来越严重地挤压轴承的滚子,加上在重载环境下... 本文采用了光学显微镜、扫描电子显微镜及硬度仪等设备,对失效的连铸机扇形段调心滚子轴承进行了分析,以探求其失效的原因。结果表明:轴承安装时存在一定的偏载,随着轴承的不断运转,偏载会越来越严重地挤压轴承的滚子,加上在重载环境下会产生更剧烈的磨损,使轴承内圈升温,最终导致轴承滚子严重挤压变形和内圈硬度下降。调心滚子轴承的内圈硬度下降最严重,其中大量珠光体的存在是其硬度降低的关键原因。 展开更多
关键词 连铸机扇形段 调心滚子轴承 偏载 珠光体
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Dissociative ionization cross sections of CO_2 at electron impact energy of 5 keV 被引量:1
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作者 王恩亮 沈镇捷 +3 位作者 阳弘江 唐亚国 单旭 陈向军 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第11期280-284,共5页
The dissociative ionization of CO2 induced by 5 keV electrons in two-body and three-body dissociative channels of CO2+2 and CO3+2 is identified by the ion-ion coincidence- method using a momentum imaging spectromete... The dissociative ionization of CO2 induced by 5 keV electrons in two-body and three-body dissociative channels of CO2+2 and CO3+2 is identified by the ion-ion coincidence- method using a momentum imaging spectrometer. The partial ionization cross sections (PICSs) of different ionic fragments are measured and the results generally agree with the calculations made by a semi-empirical approach. Furthermore, the PICSs of the dissociative channels are also obtained by carefully considering the detection efficiency of the micro-channel plates and the total transmission efficiency of the time of flight system. 展开更多
关键词 electron collision partial ionization cross section dissociative ionization cross section momentumimaging
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The direct ionization processes in the collisions of partially stripped carbon and oxygen ions with helium atoms at low-to-intermediate energies
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作者 周春林 邵剑雄 +2 位作者 陈熙萌 孙光智 邹贤容 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第11期4193-4198,共6页
The values of direct double- to-single ionization ratio R of helium atoms induced by C^q+, O^q+ (q = 1 -4) ions at incident energies from 0.2 to 8.5MeV are measured. Based on the existing model (Shao J X, Chen X ... The values of direct double- to-single ionization ratio R of helium atoms induced by C^q+, O^q+ (q = 1 -4) ions at incident energies from 0.2 to 8.5MeV are measured. Based on the existing model (Shao J X, Chen X M and Ding B W 2007 Phys. Rev. A 75 012701) the effective charge of the projectile is introduced to theoretically estimate the value of R for the partially stripped ions impacting on helium atoms. The results calculated from our "effective charge" model are in good agreement with the experimental data, and the dependence of the effective charge on the ionization energy of the projectile is also discussed qualitatively. 展开更多
关键词 effective charge partially stripped ions cross-section ratio direct ionization
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Termination of a partial hydatidiform mole and coexisting fetus: A case report
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作者 Rui-Qing Zhang Jia-Rong Zhang Shuang-Di Li 《World Journal of Clinical Cases》 SCIE 2019年第20期3289-3295,共7页
BACKGROUND We describe the treatment strategy for a patient who was found to have a partial hydatidiform mole and coexisting fetus(PHMCF)during the second trimester.The patient was a 38-year-old Chinese woman who had ... BACKGROUND We describe the treatment strategy for a patient who was found to have a partial hydatidiform mole and coexisting fetus(PHMCF)during the second trimester.The patient was a 38-year-old Chinese woman who had become pregnant following in vitro fertilization and embryo transplantation.We wanted to determine the safest therapeutic strategy to terminate the PHMCF during the second trimester.CASE SUMMARY In this case,we present a patient who was found to have a PHMCF complicated with serious continuous vaginal bleeding and pre-eclampsia during the second trimester.After careful evaluation,the pregnancy was considered to be unsustainable and was terminated via caesarean section(CS).An infant with weak vital signs and a partially cystic placenta measuring 110 mm×95 mm×35 mm were delivered by CS.The patient was discharged after 4 d.The serum levels ofβ-human chorionic gonadotropin decreased to within a normal range 5 wk after the operation,and no evidence of persistent trophoblastic disease or lung metastases was noticed at the 6-mo follow-up.CONCLUSION CS termination of PHMCF during the second trimester may be a relatively safe therapeutic strategy. 展开更多
关键词 partial hydatidiform MOLE and coexisting FETUS CAESAREAN section SECOND trimester Case report
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预制装配式型钢部分外包混凝土梁受剪性能试验研究
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作者 梁炯丰 宋瑞霖 +2 位作者 王刘浩翔 汤蒂莲 刘如来 《混凝土》 CAS 北大核心 2023年第8期154-156,共3页
提出了一种部分预制部分外包装配式组合梁,为研究其受剪性能,设计了5根预制装配式型钢部分外包混凝土(PPEC)梁和1根整浇部分外包混凝土(PEC)梁。观察了PPEC梁在竖向荷载作用下的剪切破坏特点并绘制了荷载-跨中挠度曲线,分析了混凝土强... 提出了一种部分预制部分外包装配式组合梁,为研究其受剪性能,设计了5根预制装配式型钢部分外包混凝土(PPEC)梁和1根整浇部分外包混凝土(PEC)梁。观察了PPEC梁在竖向荷载作用下的剪切破坏特点并绘制了荷载-跨中挠度曲线,分析了混凝土强度等级、剪跨比和浇筑方式对受剪承载力的影响。试验结果表明:PPEC梁截面形式与构造基本可行,破坏形式均为剪压破坏。混凝土强度越高,PPEC梁受剪承载力越高;随剪跨比增大,PPEC梁受剪承载力降低;PPEC梁受剪承载力略小于整浇PEC梁。 展开更多
关键词 装配式 型钢部分外包混凝土梁 受剪 承载力
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臭氧吸收截面关键参数研究进展
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作者 王维康 熊华竞 李怀平 《中国测试》 CAS 北大核心 2023年第9期73-81,共9页
近期,国际计量局(BIPM)修订臭氧吸收截面的新参数,这是该参数在沿用40余年后的首次变更。修订后的臭氧吸收截面值为1.1329×10^(–17)cm^(2)·molecule^(–1),相对标准不确定度0.31%,相对于现行参数,数值上减小了1.23%,不确定... 近期,国际计量局(BIPM)修订臭氧吸收截面的新参数,这是该参数在沿用40余年后的首次变更。修订后的臭氧吸收截面值为1.1329×10^(–17)cm^(2)·molecule^(–1),相对标准不确定度0.31%,相对于现行参数,数值上减小了1.23%,不确定度减小到七分之一。BIPM建议新参数于2024年开始在全球推广使用。臭氧吸收截面系数是当前国内外臭氧量值溯源体系中的关键计量参数,该参数的修订将直接影响臭氧气体浓度的测量值及其不确定度,进而影响全球的臭氧浓度监测结果。我国也同样面临该参数的修订问题,为便于相关工作的推进,该文介绍臭氧吸收截面的研究历程,阐述本次修订的背景和意义,重点讨论气相滴定法与分压法这两种臭氧吸收截面的核心研究方法的原理与技术差异,深入分析这两种方法的技术现状,以期为我国臭氧检测和量值溯源工作的进一步国际化接轨打下坚实基础。 展开更多
关键词 臭氧吸收截面 量值溯源 气相滴定法 分压法
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Differential cross sections of elastic electron scattering from CH4. CF4 and SF6 in the energy range l00-700eV
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作者 马二俊 马余刚 +3 位作者 蔡翔舟 方德清 沈文庆 田文栋 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第11期3339-3344,共6页
We investigate the differential cross sections (DCS) of elastic electron scattering from CH4, CF4 and SF6 at six impact energies in a range of 100 700eV by employing the independent atom model (IAM) together with ... We investigate the differential cross sections (DCS) of elastic electron scattering from CH4, CF4 and SF6 at six impact energies in a range of 100 700eV by employing the independent atom model (IAM) together with the relativistic partial waves. The atom is present in an optical potential which is complex, spherically symmetric, and energy dependent. The optical potential of the atom is the sum of the direct static, dynamic polarization, local exchange and modified absorption potentials. The results obtained by using a modified absorption potential show significant improvements on the unmodified absorption potential results. The present results are generally in good agreement with experimental data available. In addition, the present results indicate that the structure of molecule manifests the observable effects on electron- molecule scattering. 展开更多
关键词 differential cross sections independent atom model electron molecule scattering relativistic partial waves modified absorption potential
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500A MeV^(40)Ar与铜靶作用弹核碎裂电荷变化总截面及碎片产生分截面研究
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作者 李蓉 张东海 《山西师范大学学报(自然科学版)》 2023年第2期28-36,共9页
本文对最高能量为500 A MeV的^(40)Ar与铜靶作用弹核碎裂电荷变化总截面及碎片产生分截面进行了实验研究,并与相近能区^(40)Ar诱发铜靶核碎裂的实验结果及理论模型计算结果进行了比较.结果表明:电荷变化总截面与相近能区实验结果一致,也... 本文对最高能量为500 A MeV的^(40)Ar与铜靶作用弹核碎裂电荷变化总截面及碎片产生分截面进行了实验研究,并与相近能区^(40)Ar诱发铜靶核碎裂的实验结果及理论模型计算结果进行了比较.结果表明:电荷变化总截面与相近能区实验结果一致,也与Bradt-Peters及Nilsen半经验公式预言一致;NUCFRG2和PHITS模型预言低于实验结果.弹核碎片产生分截面在所研究的能区范围与束流能量没有明显依赖关系,EPAX3及FRACS半经验参数化公式可以较好地再现实验结果. 展开更多
关键词 核碎裂 电荷变化反应总截面 弹核碎片产生分截面
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腹板两侧部分填充混凝土新型预制组合梁受弯性能试验研究
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作者 辛力 刘源 +2 位作者 姚怡帆 史生志 廖含喻 《建筑结构》 北大核心 2023年第24期96-102,共7页
为探讨腹板两侧部分填充混凝土新型预制组合梁的受弯性能,制作两个新型预制组合梁试件和两个对比梁试件,对比梁分别为工字钢梁和传统部分外包混凝土组合梁。通过改变新型预制组合梁翼缘内侧填充混凝土厚度,研究其裂缝分布、荷载-应变变... 为探讨腹板两侧部分填充混凝土新型预制组合梁的受弯性能,制作两个新型预制组合梁试件和两个对比梁试件,对比梁分别为工字钢梁和传统部分外包混凝土组合梁。通过改变新型预制组合梁翼缘内侧填充混凝土厚度,研究其裂缝分布、荷载-应变变化规律和受弯承载力。结果表明:腹板两侧部分填充混凝土新型预制组合梁具有较好的受弯承载力,改变翼缘内侧填充混凝土厚度对组合梁极限承载力的影响不显著;新型预制组合梁与传统部分外包混凝土组合梁相比,在不降低组合梁屈服承载力和极限承载力的同时,混凝土用量和组合梁自重分别降低了63.5%和50.67%,具有良好的经济效益。基于试验结果,提出了新型预制组合梁截面受弯承载力计算公式,公式计算值与试验值吻合良好。 展开更多
关键词 腹板两侧部分填充混凝土组合梁 部分外包混凝土组合梁 预制构件 受弯性能 平截面假定 受弯承载力
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HCl-He相互作用势及碰撞截面的理论计算 被引量:3
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作者 朱俊 王彩霞 +1 位作者 孙桂华 杨向东 《四川大学学报(自然科学版)》 CAS CSCD 北大核心 1999年第3期476-482,共7页
利用三种势采用密耦合方法计算了HClHe碰撞体系的散射截面,比较了不同势模型下截面的异同,讨论了势函数的变化对散射截面的影响。
关键词 碰撞 微分截面 相互作用势 散射截面 氯化氢
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不同能量的氦原子与氢的非对称同位素替代分子碰撞分波截面理论计算 被引量:4
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作者 周晓林 李德华 +1 位作者 冯一兵 杨向东 《四川师范大学学报(自然科学版)》 CAS CSCD 2004年第4期387-390,共4页
用密耦方程(Closecouplingequation)研究和计算了氦与氢的非对称同位素替代分子HD碰撞.当入射氦原子能量分别为0.05、0.15eV和0.25eV时,考虑到非对称同位素替代时质心偏移量对势能函数的影响,计算了弹性碰撞激发00 00分波和非弹性碰撞激... 用密耦方程(Closecouplingequation)研究和计算了氦与氢的非对称同位素替代分子HD碰撞.当入射氦原子能量分别为0.05、0.15eV和0.25eV时,考虑到非对称同位素替代时质心偏移量对势能函数的影响,计算了弹性碰撞激发00 00分波和非弹性碰撞激发00 01、00 02分波截面. 展开更多
关键词 非对称同位素替代分子 分波截面 转动激发
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