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Identification of Bandhead Spin and Identical Bands for Odd-A Nuclei in A-190 Superdeformed Mass Region
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作者 A.S.Shalaby 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第3期454-460,共7页
The dynamical moment of inertia is estimated with its even-power expansion of the rotational frequency and in accordance we determine the intermediate spins of the superdeformed (SD) rotational bands. Using Marquardt ... The dynamical moment of inertia is estimated with its even-power expansion of the rotational frequency and in accordance we determine the intermediate spins of the superdeformed (SD) rotational bands. Using Marquardt method of nonlinear least-squares routines, we determine the expansion coefficients by fitting the proposed dynamical moment of inertia with its recent experimental data of the SD nuclei in the A=190 mass region. The comparison between our theoretical and available experimental data for t~he dynamic moment of inertia and spin shows good agreements.Also, we have calculated the static moment of inertia at three alternative values of spin. The value of spin at which the two moments of inertia are nearly equals is to be regarded a~ a bandhead spin of the corresponding band. These studies are carried out for eighteen bands of odd-A nuclei of the superdeformed region 190, namely ^189Hg(bl), ^191Hg(b1,b2,b3,b4), ^193Hg(b2,b3,b5), ^195Hg(b1, b2, b3, b4), ^193Tl(b1, b2, b3, bS), 189Tl(b1), and 197Bi(b1). We also notice the occurrence of identical SD bands with near identical transition energies among the considered SD bands. 展开更多
关键词 哈利斯公式 弯曲模式 超变形原子核 原子核物理 光谱分析 能带分析
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The breaking of spin symmetry in the single-particle resonances in deformed nuclei
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作者 Zhen-Yu Zheng Shou-Wan Chen Quan Liu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第3期237-245,共9页
The exploration of spin symmetry (SS) in nuclear physics has been instrumental in identifying atomic nucleus structures.In this study,we solve the Dirac equation from the relativistic mean field (RMF) in complex momen... The exploration of spin symmetry (SS) in nuclear physics has been instrumental in identifying atomic nucleus structures.In this study,we solve the Dirac equation from the relativistic mean field (RMF) in complex momentum representation.We investigated SS and its breaking in single-particle resonant states within deformed nuclei,with a focus on the illustrative nucleus168Er.This was the initial discovery of a resonant spin doublet in a deformed nucleus,with the expectation of the SS approaching the continuum threshold.With increasing single-particle energy,the splitting of the resonant spin doublets widened significantly.This escalating splitting implies diminishing adherence to the SS,indicating a departure from the expected behavior as the energy levels increase.We also analyzed the width of the resonant states,showing that lower orbital angular momentum resonances possess shorter decay times and that SS is preserved within broad resonant doublets,as opposed to narrow resonant doublets.Comparing the radial density of the upper components for the bound-state and resonant-state doublets,it becomes evident that while SS is well-preserved in the bound states,it deteriorates in the resonant states.The impact of nuclear deformation (β_(2)) on SS was examined,demonstrating that an increase in β_(2) resulted in higher energy and width splitting in the resonant spin doublets,which is attributed to increased component mixing.Furthermore,the sensitivity of spin doublets to various potential parameters such as surface diffuseness (a),radius (R),and depth (Σ0) is discussed,emphasizing the role of these parameters in SS.This study provides valuable insights into the behavior of spin doublets in deformed nuclei and their interplay with the nuclear structure,thereby advancing our understanding of SS in the resonance state. 展开更多
关键词 Spin symmetry Resonant states Deformed nuclei Complex-momentum representation
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Magnetic moment predictions of odd-A nuclei with the Bayesian neural network approach
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作者 袁子龙 田大川 +1 位作者 李剑 牛中明 《Chinese Physics C》 SCIE CAS CSCD 2021年第12期147-154,共8页
The Bayesian neural network approach has been employed to improve the nuclear magnetic moment predictions of odd-A nuclei.The Schmidt magnetic moment obtained from the extreme single-particle shell model makes large r... The Bayesian neural network approach has been employed to improve the nuclear magnetic moment predictions of odd-A nuclei.The Schmidt magnetic moment obtained from the extreme single-particle shell model makes large root-mean-square(rms)deviations from data,i.e.,0.949μN and 1.272μN for odd-neutron nuclei and odd-proton nuclei,respectively.By including the dependence of the nuclear spin and Schmidt magnetic moment,the machine-learning approach precisely describes the magnetic moments of odd-A uclei with rms deviations of 0.036μN for odd-neutron nuclei and 0.061μN for odd-proton nuclei.Furthermore,the evolution of magnetic moments along isotopic chains,including the staggering and sudden jump trend,which are difficult to describe using nuclear models,have been well reproduced by the Bayesian neural network(BNN)approach.The magnetic moments of doubly closed-shell±1 nuclei,for example,isoscalar and isovector magnetic moments,have been well studied and compared with the corresponding non-relativistic and relativistic calculations. 展开更多
关键词 magnetic moment odd-a nuclei Bayesian neural network approach
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α-decay Branching Ratios to Rotational Band of Heavy Even-even and Odd-A Nuclei
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作者 REN Zhong-zhou1,2,3,XU Chang2,3 (1 Center of Theoretical Nuclear Physics,National Laboratory of Heavy Ion Research Facility in Lanzhou,Lanzhou 730000,China 2 Department of Physics,Nanjing University,Nanjing 210008,China 3 Joint Center for Particle,Nuclear Physics and Cosmology,Nanjing 210008,China) 《原子核物理评论》 CAS CSCD 北大核心 2009年第S1期55-58,共4页
By using a simple barrier penetration approach,we predict the α-decay branching ratios to members of ground-state rotational band of heavy even-even No isotopes. We also extend our approach to calculate the α-decay ... By using a simple barrier penetration approach,we predict the α-decay branching ratios to members of ground-state rotational band of heavy even-even No isotopes. We also extend our approach to calculate the α-decay branching ratios to the rotational band of heavy odd-A nuclei. The theoretical branching ratios of α-decays are found in good agreement with the available experimental data. 展开更多
关键词 Α-DECAY branching RATIO HEAVY nuclei
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Constraining nuclear symmetry energy with the charge radii of mirror-pair nuclei 被引量:1
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作者 Rong An Shuai Sun +1 位作者 Li-Gang Cao Feng-Shou Zhang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第8期154-163,共10页
The nuclear charge radius plays a vital role in determining the equation of state of isospin asymmetric nuclear matter.Based on the correlation between the differences in charge radii of mirror-partner nuclei and the ... The nuclear charge radius plays a vital role in determining the equation of state of isospin asymmetric nuclear matter.Based on the correlation between the differences in charge radii of mirror-partner nuclei and the slope parameter(L)of symmetry energy at the nuclear saturation density,an analysis of the calibrated slope parameter L was performed in finite nuclei.In this study,relativistic and nonrelativistic energy density functionals were employed to constrain the nuclear symmetry energy through the available databases of the mirror-pair nuclei^(36)Ca–^(36)S,^(38)Ca–^(38)Ar,and ^(54)Ni–^(54)Fe.The deduced nuclear symmetry energy was located in the range 29.89–31.85 MeV,and L of the symmetry energy essentially covered the range 22.50–51.55 MeV at the saturation density.Moreover,the extracted L_(s) at the sensitivity density p_(s)=0.10 fm^(-3) was located in the interval range 30.52–39.76 MeV. 展开更多
关键词 Symmetry energy Charge radii Mirror nuclei
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Study of weakly-bound odd-A nuclei with quasiparticle blocking
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作者 熊雪宇 裴俊琛 +1 位作者 张一怒 朱怡 《Chinese Physics C》 SCIE CAS CSCD 2016年第2期19-24,共6页
The coordinate-space Hartree-Fock-Bogoliubov(HFB) approach with quasiparticle blocking has been applied to study the odd-A weakly bound nuclei ^17,19B and ^37Mg,in which halo structures have been reported in experim... The coordinate-space Hartree-Fock-Bogoliubov(HFB) approach with quasiparticle blocking has been applied to study the odd-A weakly bound nuclei ^17,19B and ^37Mg,in which halo structures have been reported in experiments.The Skyrme nuclear forces SLy4 and UNEDF1 have been adopted in our calculations.The results with and without blocking have been compared to demonstrate the emergence of deformed halo structures due to blocking effects.In our calculations,^19B and ^37Mg have remarkable features of deformed halos. 展开更多
关键词 deformed halo blocking effects weakly bound nuclei Hartree-Fock-Bogoliubov
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Stability of Nuclei Based on the New Proton and Neutron Model
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作者 Ágnes Cziráki 《Natural Science》 2023年第12期289-299,共11页
According to the new proton and neutron nuclear picture described earlier, the structure of the nucleus will also be given a new interpretation. The role of the delocalized electrons detached from the outer shell of n... According to the new proton and neutron nuclear picture described earlier, the structure of the nucleus will also be given a new interpretation. The role of the delocalized electrons detached from the outer shell of neutrons is shown in the binding energy value of the nucleus. It is pointed out that the spatial arrangement of nucleons is also very important for the stability of nuclei according to the analyzation of the magic numbers from a geometric point of view. 展开更多
关键词 New Nuclear Picture of nuclei Stability of nuclei Binding Energy Magic Numbers
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Nuclei Segmentation in Histopathology Images Using Structure-Preserving Color Normalization Based Ensemble Deep Learning Frameworks
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作者 Manas Ranjan Prusty Rishi Dinesh +2 位作者 Hariket Sukesh Kumar Sheth Alapati Lakshmi Viswanath Sandeep Kumar Satapathy 《Computers, Materials & Continua》 SCIE EI 2023年第12期3077-3094,共18页
This paper presents a novel computerized technique for the segmentation of nuclei in hematoxylin and eosin(H&E)stained histopathology images.The purpose of this study is to overcome the challenges faced in automat... This paper presents a novel computerized technique for the segmentation of nuclei in hematoxylin and eosin(H&E)stained histopathology images.The purpose of this study is to overcome the challenges faced in automated nuclei segmentation due to the diversity of nuclei structures that arise from differences in tissue types and staining protocols,as well as the segmentation of variable-sized and overlapping nuclei.To this extent,the approach proposed in this study uses an ensemble of the UNet architecture with various Convolutional Neural Networks(CNN)architectures as encoder backbones,along with stain normalization and test time augmentation,to improve segmentation accuracy.Additionally,this paper employs a Structure-Preserving Color Normalization(SPCN)technique as a preprocessing step for stain normalization.The proposed model was trained and tested on both single-organ and multi-organ datasets,yielding an F1 score of 84.11%,mean Intersection over Union(IoU)of 81.67%,dice score of 84.11%,accuracy of 92.58%and precision of 83.78%on the multi-organ dataset,and an F1 score of 87.04%,mean IoU of 86.66%,dice score of 87.04%,accuracy of 96.69%and precision of 87.57%on the single-organ dataset.These findings demonstrate that the proposed model ensemble coupled with the right pre-processing and post-processing techniques enhances nuclei segmentation capabilities. 展开更多
关键词 nuclei segmentation image segmentation ensemble U-Net deep learning histopathology image convolutional neural networks
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Cyclic feeding regime may delay aging in animals by enhancing the hepatocytes nuclei structure
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作者 Ceasar Dubor Danladi Anatoli Bozhkov Ivanovich Nedime Serakinci 《Aging Communications》 2023年第1期29-34,共6页
Background:The liver is fundamental for keeping up the entire body’s homeostasis.The liver hepatocytes have been shown to undergo genomic instability with aging.The stability of the hepatocytes depends on its nuclear... Background:The liver is fundamental for keeping up the entire body’s homeostasis.The liver hepatocytes have been shown to undergo genomic instability with aging.The stability of the hepatocytes depends on its nuclear architecture.Calorie restriction has been shown to extend life-span favorably and this may be through the reorganization of the nuclear structure.Objective:To study the effect of cyclic feeding regime on the chromatin assembly anchored to the nuclear membrane scaffold of rat models hepatocytes nuclei.Method:Rats models underwent cyclic feeding regime,after which nuclei were isolated;then,we investigated the chromatin decondensation and nuclear membrane disintegration of the hepatocytes using fluorescence imaging methods.Results:In 60 seconds,protease decondensed the chromatin and disintegrated the nuclear membrane structure of controls.After the first fasting,the time increased to 145 seconds in 3-month-old rats.The first refeeding increased the time to 156 seconds with a further rise to 340 seconds following the second fasting,then dropped to 116 seconds by the second refeeding.20 months old rats showed 186 seconds increase in the time of chromatin decondensation and nuclear membrane disintegration after the first fasting,with a decrease to 140 seconds observed after first refeeding.The second fasting increased the time to 165 seconds,which then slightly decreased to 163 seconds after the second refeeding.Conclusion:These results show that intermittent fasting may have acted on chromatin histone interactions and the structural lamin networks of the nuclear membranes in bringing about nuclear stability,which is essential for normal cellular function. 展开更多
关键词 AGING hepatocytes nuclei cyclic feeding regime nuclear stability
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首发抑郁症伴自杀意念患者中缝核功能连接的改变
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作者 姜雨 陈苑 +4 位作者 韩少强 郑瑞平 周冰倩 李淑英 程敬亮 《中国介入影像与治疗学》 北大核心 2024年第1期22-27,共6页
目的观察首发抑郁症伴自杀意念(SI)患者中缝核功能连接(FC)改变。方法前瞻性纳入98例首发抑郁症患者,根据伴SI与否将其分为伴SI组(n=56)与不伴SI组(n=42);另以47名健康志愿者为对照组。以静息态功能MRI观察背侧中缝核(DRN)、中缝中央核(... 目的观察首发抑郁症伴自杀意念(SI)患者中缝核功能连接(FC)改变。方法前瞻性纳入98例首发抑郁症患者,根据伴SI与否将其分为伴SI组(n=56)与不伴SI组(n=42);另以47名健康志愿者为对照组。以静息态功能MRI观察背侧中缝核(DRN)、中缝中央核(MRN)与全脑间的FC;比较3组及两两组间FC,分析伴SI组差异脑区FC与临床资料的相关性。结果相比对照组,伴与不伴SI组DRN与左侧小脑及左侧壳核的FC均降低(P均<0.05),MRN与右侧颞下回的FC均升高而与左侧额下回、右侧枕上回、左侧顶下小叶及左侧壳核的FC均降低(P均<0.05);其中,伴SI组DRN与左侧壳核的FC高于不伴SI组(P<0.05);相比不伴SI组及对照组,伴SI组MRN与右侧中央后回的FC升高(P均<0.05)。伴SI组MRN与左侧壳核的FC与24项汉密尔顿抑郁量表(HAMD-24)体质量得分呈正相关(r_(s)=0.297,P=0.026)。结论首发抑郁症伴SI患者中缝核与皮层和皮层下区的FC存在异常改变,且其MRN与左侧壳核的FC与HAMD-24体质量得分呈正相关。 展开更多
关键词 抑郁症 自杀 功能连接 中缝核 磁共振成像 前瞻性研究
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延胡索酸水合酶与2琥珀酸半胱氨酸在初筛延胡索酸水合酶缺陷型子宫平滑肌瘤的应用价值
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作者 方甜甜 施凤 +2 位作者 钱宁 张维菊 顾芸 《临床与实验病理学杂志》 CAS 北大核心 2024年第3期251-254,共4页
目的探讨延胡索酸水合酶(fumarate hydratase,FH)和2琥珀酸半胱氨酸(2-succinocysteine,2SC)在具有奇异核特征平滑肌瘤中的表达,分析2种蛋白在初筛延胡索酸水合酶缺陷型(fumarate hydratase-deficient,FH-d)平滑肌瘤中的诊断价值。方法... 目的探讨延胡索酸水合酶(fumarate hydratase,FH)和2琥珀酸半胱氨酸(2-succinocysteine,2SC)在具有奇异核特征平滑肌瘤中的表达,分析2种蛋白在初筛延胡索酸水合酶缺陷型(fumarate hydratase-deficient,FH-d)平滑肌瘤中的诊断价值。方法收集67例具有奇异核特征平滑肌瘤的临床资料,采用免疫组化EnVision两步法染色,分析FH、2SC表达与FH-d型平滑肌瘤形态学特征的相关性,并复习相关文献。结果67例患者有27例为FH-d型平滑肌瘤,FH在FH-d型平滑肌瘤中的阳性率为(2/27,7.41%),低于无FH-d形态平滑肌瘤(31/40,77.50%);2SC在FH-d型平滑肌瘤中的阳性率为(26/27,96.30%),高于无FH-d形态平滑肌瘤(11/40,27.50%)。统计学显示FH和2SC的表达存在相关性(P<0.05),且FH、2SC阳性与显著嗜酸性核仁、核仁周围空晕、嗜酸性包涵体和鹿角形血管均有关(P<0.05)。FH免疫组化染色显示FH-d型平滑肌瘤的敏感度为92.59%,特异度77.50%。2SC免疫组化染色显示FH-d型平滑肌瘤的敏感度为96.30%,特异度为72.50%。结论多数FH-d形态的平滑肌瘤中FH阴性和2SC阳性,对两者行联合检测可显著提高FH-d型平滑肌瘤的诊断准确性。 展开更多
关键词 FH缺陷型平滑肌瘤 奇异核平滑肌瘤 延胡索酸水合酶 2琥珀酸半胱氨酸
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基于Transformer与距离图谱的泛癌细胞核图像分割
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作者 鲁浩达 梁实 +2 位作者 顾松 王向学 徐军 《南京信息工程大学学报(自然科学版)》 CAS 北大核心 2024年第1期66-75,共10页
肿瘤细胞的密度、核质比和平均尺寸等指标对癌症的分级和预后有重要的意义.在计算病理学中,细胞核分割是肿瘤微环境分析的基础.通过对分割结果进行统计分析,对新的肿瘤标记物的探索有重大的意义.病理图像背景下的细胞核形态不规则,细胞... 肿瘤细胞的密度、核质比和平均尺寸等指标对癌症的分级和预后有重要的意义.在计算病理学中,细胞核分割是肿瘤微环境分析的基础.通过对分割结果进行统计分析,对新的肿瘤标记物的探索有重大的意义.病理图像背景下的细胞核形态不规则,细胞核染色不均匀,且细胞核边缘之间存在黏连的问题,而现有的深度学习算法在细胞核主体分割正确的情况下,边缘的分割错误不会对总体的损失造成太大的影响,黏连的细胞核很容易被当作同一个分割目标.为了解决细胞核重叠问题,本文提出一种基于Transformer与距离图谱的分割模型,将Transformer中的核心多头自注意力机制与距离图谱引导算法相结合,重视细胞核内部,弱化细胞核边界,提升对图像局部和全局上下文信息的学习能力.本文方法在两个公开数据集上的平均Dice系数为0.7979、精度为0.7561、AJI系数为0.6672、Hausdorff距离为10.11.实验结果表明,相较其他分割算法,本文方法的性能更好,能够有效提高细胞核的分割精度,同时较好地解决了细胞核之间的黏连问题. 展开更多
关键词 深度学习 病理图像 细胞核分割 TRANSFORMER 多头自注意力 距离图谱
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运动疲劳通过基底神经节输出核团损伤大鼠工作记忆能力
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作者 金硕 李鸿扬 +2 位作者 吉宸萱 祁金顺 孙丽娜 《神经解剖学杂志》 CAS CSCD 北大核心 2024年第1期9-15,共7页
目的:探讨基底神经节输出核团[脚内核(EPN)和黑质网状部(SNr)]内小清蛋白(PV)阳性神经元参与运动疲劳损害工作记忆能力的神经调控机制。方法:采用随机数字法将雄性SD大鼠分为对照组(Control)和疲劳组(Fatigue),选用三级递增负荷跑台训... 目的:探讨基底神经节输出核团[脚内核(EPN)和黑质网状部(SNr)]内小清蛋白(PV)阳性神经元参与运动疲劳损害工作记忆能力的神经调控机制。方法:采用随机数字法将雄性SD大鼠分为对照组(Control)和疲劳组(Fatigue),选用三级递增负荷跑台训练方案,建立慢性力竭运动疲劳模型。利用Y迷宫自主交替实验评估大鼠的工作记忆能力。免疫组织化学染色观察大鼠EPN和SNr内PV和caspase-3的表达。结果:Y迷宫自主交替实验表明,疲劳组大鼠自主交替正确率较对照组大鼠呈显著性降低(P<0.05)。免疫组织化学染色结果显示,疲劳组大鼠EPN和SNr内PV阳性细胞密度和阳性纤维染色程度与对照组相比均大幅降低(P<0.05,P<0.01)。同时,疲劳组大鼠EPN和SNr内caspase-3阳性细胞密度明显升高(P<0.05,P<0.01)。结论:运动疲劳导致大鼠工作记忆能力受损,其机制可能与EPN和SNr内PV阳性神经元凋亡有关。 展开更多
关键词 运动疲劳 工作记忆 基底神经节输出核团 小清蛋白 CASPASE-3 大鼠
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α-synuclein C端截短体的胞内分布 被引量:1
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作者 马开利 苑玉和 +4 位作者 胡金凤 孙建栋 刘岩 李博宇 陈乃宏 《中国药理学通报》 CAS CSCD 北大核心 2010年第1期36-39,共4页
目的研究α-synuclein的4种C端截短体胞内的表达分布情况。方法PCR法获得α-synuclein的4个C端截短体基因片段,分别克隆入pEGFP-N1载体,并转染MN9D细胞、PC12细胞及SH-SY5Y细胞,于Confocal荧光显微镜下观察α-synuclein 4个C端截短体胞... 目的研究α-synuclein的4种C端截短体胞内的表达分布情况。方法PCR法获得α-synuclein的4个C端截短体基因片段,分别克隆入pEGFP-N1载体,并转染MN9D细胞、PC12细胞及SH-SY5Y细胞,于Confocal荧光显微镜下观察α-synuclein 4个C端截短体胞内的表达分布情况。结果α-synuclein的不同C端截短体胞内分布明显不一致,表现为随着C端部分的增长,α-synuclein截短体向核分布的趋势增强。结论α-synuclein的胞内定位与其C端密切相关,并且整个C端序列都可能在其核分布中发挥重要作用。 展开更多
关键词 Α-SYnucleiN 截短体 核分布 MN9D细胞 PC12细胞 SH-SY5Y细胞
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Isotopic dependence of the yield ratios of light fragments from different projectiles and their unified neutron skin thicknesses
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作者 Ting-Zhi Yan Shan Li 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第3期228-236,共9页
The yield ratios of neutron-proton(R(n/p))and^(3)H-^(3)He(R(^(3)H∕^(3)He))with reduced rapidity from 0 to 0.5 were simulated at 50 MeV/u even-even ^(36−56)Ca+^(40)Ca,even-even ^(48−78)Ni+^(58)Ni,and ^(100−139)Sn(ever... The yield ratios of neutron-proton(R(n/p))and^(3)H-^(3)He(R(^(3)H∕^(3)He))with reduced rapidity from 0 to 0.5 were simulated at 50 MeV/u even-even ^(36−56)Ca+^(40)Ca,even-even ^(48−78)Ni+^(58)Ni,and ^(100−139)Sn(every third isotopes)+112 Sn for full reduced impact parameters using the isospin-dependent quantum molecular dynamics(IQMD)model.The neutron and proton density distributions and root-mean-square radii of the reaction systems were obtained using the Skyrme-Hartree-Fock model,which was used for the phase space initialization of the projectile and target in IQMD.We defined the unified neutron skin thickness asΔRnp=<r^(2)>^(1∕2) n−<r^(2)>^(1∕2)p,which was negative for neutron-deficient nuclei.The unifiedΔRnp values for nuclei with the same relative neutron excess from different isotopic chains were nearly equal,except for extreme neutron-rich isotopes,which is a type of scaling behavior.The yield ratios of the three isotopic chain-induced reactions,which depended on the reduced impact parameter and unified neutron skin thickness,were studied.The results showed that both R(n/p)and R(^(3)H∕^(3)He)decreased with a reduced impact parameter for extreme neutron-deficient isotopes;however,they increased with reduced impact parameters for extreme neutron-rich isotopes,and increased with theΔRnp of the projectiles for all reduced impact parameters.In addition,a scaling phenomenon was observed betweenΔR np and the yield ratios in peripheral colli-sions from different isotopic chain projectiles(except for extreme neutron-rich isotopes).Thus,R(n/p)and R(^(3)H∕^(3)He)from peripheral collisions were suggested as experimental probes for extracting the neutron or proton skin thicknesses of non-extreme neutron-rich nuclei from different isotopic chains. 展开更多
关键词 Exotic nuclei Unified neutron skin thickness Yield ratios IQMD
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Multi-layer phenomena in petawatt laser-driven acceleration of heavy ions
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作者 苏琬晴 曹喜光 +2 位作者 马春旺 王玉廷 张国强 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第2期70-76,共7页
Laser-accelerated high-flux-intensity heavy-ion beams are important for new types of accelerators.A particle-in-cell program(Smilei) is employed to simulate the entire process of Station of Extreme Light(SEL) 100 PW l... Laser-accelerated high-flux-intensity heavy-ion beams are important for new types of accelerators.A particle-in-cell program(Smilei) is employed to simulate the entire process of Station of Extreme Light(SEL) 100 PW laser-accelerated heavy particles using different nanoscale short targets with a thickness of 100 nm Cr, Fe, Ag, Ta, Au, Pb, Th and U, as well as 200 nm thick Al and Ca. An obvious stratification is observed in the simulation. The layering phenomenon is a hybrid acceleration mechanism reflecting target normal sheath acceleration and radiation pressure acceleration, and this phenomenon is understood from the simulated energy spectrum,ionization and spatial electric field distribution. According to the stratification, it is suggested that high-quality heavy-ion beams could be expected for fusion reactions to synthesize superheavy nuclei. Two plasma clusters in the stratification are observed simultaneously, which suggest new techniques for plasma experiments as well as thinner metal targets in the precision machining process. 展开更多
关键词 petawatt laser-plasma interaction laser-driven heavy-ion accelerator for synthesizing superheavy nuclei PARTICLE-IN-CELL multi-layer phenomena target fabrication
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不同修复方法改善因固定不良引起细胞核灰染的比较
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作者 丁诗情 《实用医技杂志》 2024年第3期210-212,F0003,共4页
目的探索不同修复方法对改善因固定不良导致苏木精-伊红(HE)染色细胞核灰染的效果,提高HE染色质量。方法收集7例因固定不良导致HE染色细胞核灰染的胃肠镜活检小组织,重新切片,用磷酸盐缓冲液(PBS)高温高压、水煮,柠檬酸盐修复液高温高... 目的探索不同修复方法对改善因固定不良导致苏木精-伊红(HE)染色细胞核灰染的效果,提高HE染色质量。方法收集7例因固定不良导致HE染色细胞核灰染的胃肠镜活检小组织,重新切片,用磷酸盐缓冲液(PBS)高温高压、水煮,柠檬酸盐修复液高温高压、水煮以及乙二胺四乙酸(EDTA)抗原修复液高温高压、水煮6种方法修复后行HE染色,以此设为对照,比较各种方法的染色效果。结果6种方法都可以改善细胞核灰染的问题,同时使组织中幽门螺杆菌更易于观察,以PBS缓冲液和柠檬酸盐修复液高温高压修复效果较好,EDTA抗原修复液高温高压和水煮都有细胞核挤压变形,胞质被破坏的现象。结论PBS缓冲液和柠檬酸盐修复液高温高压都可以较好地改善细胞核灰染问题,并使幽门螺杆菌更易于观察。 展开更多
关键词 苏木精-伊红染色 细胞核灰染 修复 幽门螺杆菌
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Low-Level Temperature Inversions and Their Effect on Aerosol Condensation Nuclei Concentrations under Different Large-Scale Synoptic Circulations 被引量:13
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作者 LI Jun CHEN Hongbin +3 位作者 Zhanqing LI WANG Pucai Maureen CRIBB FAN Xuehua 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2015年第7期898-908,共11页
Knowledge of the statistical characteristics of inversions and their effects on aerosols under different large-scale synoptic circulations is important for studying and modeling the diffusion of pollutants in the boun... Knowledge of the statistical characteristics of inversions and their effects on aerosols under different large-scale synoptic circulations is important for studying and modeling the diffusion of pollutants in the boundary layer. Based on results gen- erated using the self-organizing map (SOM) weather classification method, this study compares the statistical characteristics of surface-based inversions (SBIs) and elevated inversions (EIs), and quantitatively evaluates the effect of SBIs on aerosol condensation nuclei (CN) concentrations and the relationship between temperature gradients and aerosols for six prevailing synoptic patterns over the the Southern Great Plains (SGP) site during 2001-10. Large-scale synoptic patterns strongly influ- ence the statistical characteristics of inversions and the accumulation of aerosols in the low-level atmosphere. The activity, frequency, intensity, and vertical distribution of inversions are significantly different among these synoptic patterns. The verti- cal distribution of inversions varies diurnally and is significantly different among the different synoptic patterns. Anticyclonic patterns affect the accumulation of aerosols near the ground more strongly than cyclonic patterns. Mean aerosol CN con- centrations increase during SBIs compared to no inversion cases by 16.1%, 22.6%, 24.5%, 58.7%, 29.8% and 23.7% for the six synoptic patterns. This study confirms that there is a positive correlation between temperature gradients and aerosol CN concentrations near the ground at night under similar large-scale synoptic patterns. The relationship is different for different synoptic patterns and can be described by linear functions. These findings suggest that large-scale synoptic patterns change the static stability of the atmosphere and inversions in the lower atmosphere, thereby influencing the diffusion of aerosols near the ground. 展开更多
关键词 temperature inversion AEROSOL condensation nuclei large-scale synoptic pattern statistical characteristics
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Discussion of RE Inclusions as Heterogeneous Nuclei of Primary Austenite in Hardfacing Metals of Medium-High Carbon Steels 被引量:5
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作者 杨庆祥 任学军 +2 位作者 廖波 姚枚 万鑫 《Journal of Rare Earths》 SCIE EI CAS CSCD 1999年第4期293-297,共5页
As the substrate for nucleation of primary austenite in hardfacing metals, the effectiveness of RE inclusions and the most common inclusions such as Al2O3, SiO2 and MnO in hardfacing metals of medium-high carbon steel... As the substrate for nucleation of primary austenite in hardfacing metals, the effectiveness of RE inclusions and the most common inclusions such as Al2O3, SiO2 and MnO in hardfacing metals of medium-high carbon steels was analyzed and calculated in detail. The calculation based on the theory of planar lattice misfit shows that Ce2O3, La2O3 and Ce2O2S, instead of SiO2, Al2O3, MnO and CeS, are effective as the heterogeneous nuclei of primary austenite in medium-high carbon steels. 展开更多
关键词 rare earths INCLUSIONS heterogeneous nuclei primary gamma phase
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Study on Heterogeneous Nuclei in Cast H13 Steel Modified by Rare Earth 被引量:4
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作者 兰杰 贺俊杰 +2 位作者 丁文江 王渠东 朱燕萍 《Journal of Rare Earths》 SCIE EI CAS CSCD 2001年第4期280-283,共4页
The dendrite segregation in cast H13 steel was weakened with RE modification treatment. Grain boundary carbide during quenching was also under control and impact toughness was improved greatly. By thermodynamic calcul... The dendrite segregation in cast H13 steel was weakened with RE modification treatment. Grain boundary carbide during quenching was also under control and impact toughness was improved greatly. By thermodynamic calculation, analysis of two-dimensional lattice misfitting and electron probe analysis, it is found that Ce2O3 may act as the heterogeneous nuclei of modified cast H13 steel. 展开更多
关键词 rare earths cast H13 steel MODIFICATION heterogeneous nuclei
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