检索结果-南通市图书馆

L-Shell Ionization Study of Tungsten by Electron Impact

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2001年第1期18卷 39-41页

作者： PENG Xiu-Feng HE Fu-Qing long xian-guan AN Zhu LUO Zheng-Ming Key Laboratory for Radiation Physics and Technology of Education Ministry of China Institute of Nuclear Science and TechnologySichuan UniversityChengdu 610064

L-shell partial production cross sections of L_(α)-,L_(β)-,L_(γ)-rays by electron impact were measured by observing the counts of x-rays from an impacted thin tungsten *** total production cross sections and mean ionization cross sections were deduced from the measured *** electron beam energy range was found to be 11-36 *** influence of electrons reflected by the backing on ionization cross sections has been *** experimental results agree well with the theoretical predictions.

关键词： Impact Electron sections

Activation Cross Section Measurement for the ^(165)Ho(n,γ)^(166)Ho^(m) Reaction

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese journal of nuclear physics 1995年第1期17卷 43-44页

作者： Xia Yi-jun long xian-guan Luo Xiao-bing Yang Zhi-hua Liu Man-tian Wang Chun-hao Yang Jing-fu He Fu-qing Peng Xiu-feng Lu Han-lin Institute of Nuclear Science and Technology Sichuan UniversityChengdu 610064 China INstitute of Atomic Energy.P.O.Box 275(3).Beijing 102413

The cross sections for the 165Ho（n.γ）166Ho? reaction have been measured rel-ative to the 197Au（n.γ）198Au reaction at neutron energies of 203,676 and 974 keV usingthe activation technique in combination With high... 详细信息

关键词： Activation technique ^(165)Ho(n,γ)^(166)Ho^(m) Activation cross section

在线全文

学校读者我要写书评

暂无评论

OLAM神经网络分析X荧光谱的预处理研究

四川大学学报（自然科学版） 2009年第5期46卷 1357-1360页

作者：黄宁王鹏龙先灌四川大学原子核科学技术研究所成都610064

在采用最优线性联想记忆(Optimal Linear Associative Memory)神经网络分析X荧光谱时,可用多种方式对谱作预处理,如去掉多余数据、取对数、横向压缩、标准化等.针对实验测得的水泥生料X荧光谱,分别用上述方法进行预处理,然后再用神经网... 详细信息

在采用最优线性联想记忆(Optimal Linear Associative Memory)神经网络分析X荧光谱时,可用多种方式对谱作预处理,如去掉多余数据、取对数、横向压缩、标准化等.针对实验测得的水泥生料X荧光谱,分别用上述方法进行预处理,然后再用神经网络分析,与化学分析的偏差作对比.结果表明,去掉多余数据、横向压缩可以减少信息处理量,减少存储空间,提高运算速度,且对精度影响较小;标准化处理对含量较少的成分有优势,对含量大的成分误差太大;对数方法则不适用.

关键词：最优线性联想记忆 X荧光谱预处理水泥生料

在线全文

学校读者我要写书评

暂无评论

原子核—原子核散射的微观描述

四川大学学报(自然科学版) 1981年第3期 53-58页

作者：龙先灌

本文利用生成坐标方法和共振群办方法的等价性,使用Kohn的变分技术处理具有非定域势的薛定格方程,得出了原子核—原子核散射相移的一般表示式.

关键词：原子核反应方程波函数等价性波动力学共振群方法生成坐标方法

最优线性联想记忆网络方法在人发X射线荧光分析中的应用研究

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

四川大学学报（自然科学版） 2000年第4期37卷 558-562页

作者：袁学东吴丽萍龙先灌周厚全四川大学物理系成都610064 四川大学原子核科学技术研究所成都610064

作者针对X荧光分析中散射峰干扰和直线拟合精度差等问题 ,采用最优线性联想记忆 (OLAM )神经网络方法解谱 ,研究了无散射峰标准谱的产生和本底干扰问题 .通过用一维高斯分布随机数模拟本底计数产生无散射峰标准谱的方法 ,提高了分析精度 .

关键词： X射线荧光分析 OLAM神经网络微量元素人发

MHCII类分子反式激活因子突变体重组腺病毒治疗小鼠实验性自身免疫性甲状腺炎

在线全文

学校读者我要写书评

暂无评论

现代免疫学 2008年第4期28卷 312-317页

作者：龙宪连管政张军沈茜第二军医大学长海医院实验诊断科上海200433

评估IFN-γ调控型启动子(CIITA-pIV)驱动的MHC II类分子反式激活因子突变体(MHC class II transactivator mu-tant,CIITAm)重组腺病毒Ad-pIV-CIITAm对小鼠实验性自身免疫性甲状腺炎(experimental autoimmune thyroiditis,EAT)的治疗效果,并探讨其可能的作用机制。34只健康雌性CBA/J小鼠随机分成CIITAm治疗组(n=9)、GFP对照组(n=9)、EAT模型组(n=8)和正常对照组(n=8)共四组。正常对照组不做特殊处理,其余三组均以猪甲状腺球蛋白(porcinethyroglobulin,pTg)+弗氏佐剂(complete or incomplete Freund adjuvant,CFA/IFA)建立EAT小鼠模型,并分别静脉注射重组腺病毒Ad-pIV-CIITAm、Ad-GFP及等体积生理盐水。首次免疫后第29天处死小鼠,进行H-E染色观察甲状腺病理形态;免疫组织化学染色测定甲状腺MHC II类分子表达;分析pTg刺激下脾脏淋巴细胞的增殖及其上清液中IFN-γ的分泌水平;ELISA法检测血浆中抗-pTg自身抗体滴度;流式细胞术分析外周血和脾脏淋巴细胞中T细胞亚群。结果:H-E染色结果表明,CIITAm治疗组甲状腺淋巴细胞浸润指数(0.5±0.5)低于GFP对照组(1.5±0.2)和EAT模型组(1.4±0.4,P<0.01)。免疫组化结果显示,GFP对照组和EAT模型组甲状腺组织有弥漫性MHC II类分子表达,而CIITAm治疗组未见明显表达,正常对照组表达呈阴性。80μg/ml pTg刺激下,CIITAm治疗组小鼠淋巴细胞刺激指数(SI)明显低于GFP对照组或EAT模型组(P<0.01);培养上清各组IFN-γ分泌水平结果类似(P<0.01)。CIITAm治疗组血浆抗-pTg自身抗体滴度显著低于GFP对照组或EAT模型组(P<0.05);CIITAm治疗组外周血和脾脏CD4+T细胞百分率亦显著低于GFP对照组或EAT模型组(P<0.05)。重组腺病毒Ad-pIV-CIITAm能抑制EAT小鼠甲状腺组织MHC II类分子表达,抑制自身反应性T细胞增殖,减轻甲状腺炎性细胞浸润,降低自身抗体滴度,对EAT有一定的治疗作用。

关键词： MHCII类分子反式激活因子突变体腺病毒科自身免疫性甲状腺炎基因治疗 γ干扰素

Endoplasmic reticulum stress and autophagy in cerebral ischemia/reperfusion injury:PERK as a potential target for intervention

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第5期20卷 1455-1466页

作者： Ju Zheng Yixin Li Ting Zhang Yanlin Fu Peiyan long Xiao Gao Zhengwei Wang Zhizhong guan Xiaolan Qi Wei Hong Yan Xiao Key Laboratory of Endemic and Ethnic Diseases Ministry of Education&Key Laboratory of Medical Molecular Biology of Guizhou ProvinceGuizhou Medical UniversityGuiyangGuizhou ProvinceChina Guizhou Center for Disease Control and Prevention GuiyangGuizhou ProvinceChina Department of Histology and Embryology Guizhou Medical UniversityGuiyangGuizhou ProvinceChina Collaborative Innovation Center for Prevention and Control of Endemic and Ethnic Regional Diseases Co-constructed by the Province and Ministry GuiyangGuizhou ProvinceChina

Several studies have shown that activation of unfolded protein response and endoplasmic reticulum(ER)stress plays a crucial role in severe cerebral ischemia/reperfusion *** occurs within hours after cerebral ischemia,but the relationship between ER stress and autophagy remains *** this study,we established experimental models using oxygen-glucose deprivation/reoxygenation in PC12 cells and primary neurons to simulate cerebral ischemia/reperfusion *** found that prolongation of oxygen-glucose deprivation activated the ER stress pathway protein kinase-like endoplasmic reticulum kinase(PERK)/eukaryotic translation initiation factor 2 subunit alpha(e IF2α)-activating transcription factor 4(ATF4)-C/EBP homologous protein(CHOP),increased neuronal apoptosis,and induced ***,inhibition of ER stress using inhibitors or by si RNA knockdown of the PERK gene significantly attenuated excessive autophagy and neuronal apoptosis,indicating an interaction between autophagy and ER stress and suggesting PERK as an essential target for regulating *** autophagy with chloroquine exacerbated ER stress-induced apoptosis,indicating that normal levels of autophagy play a protective role in neuronal injury following cerebral ischemia/reperfusion *** from this study indicate that cerebral ischemia/reperfusion injury can trigger neuronal ER stress and promote autophagy,and suggest that PERK is a possible target for inhibiting excessive autophagy in cerebral ischemia/reperfusion injury.

关键词： apoptosis ATF4 autophagy C/EBP homologous protein cerebral ischemia/reperfusion injury eIF2α endoplasmic reticulum stress PERK

Biological object recognition approach using space variant resolution and pigeon-inspired optimization for UAV

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2017年第10期60卷 1577-1584页

作者： XIN long xian Ning State Key Laboratory of 14rtual Reality Technology and Systems Beihang University Beijing 100191 China

Recognizing the target from a rotated and scaled image is an important and difficult task for computer vision. Visual system of humans has a unique space variant resolution mechanism(SVR) and log-polar transformations(LPT) is a mapping method that is invariant to rotation and scale. Motivated by biological vision, we propose a novel global LPT based template-matching algorithm(GLPT-TM) which is invariant to rotational and scale changes; and with pigeon-inspired optimization(PIO) used to optimize search strategy, a hybrid model of SVR and pigeon-inspired optimization(SVRPIO) is proposed to accomplish object recognition for unmanned aerial vehicles(UAV) with rotational and scale changes of the target. To demonstrate the efficiency, effectiveness and reliability of the proposed method, a series of experiments are carried out. By rotating and scaling the sample image randomly and recognizing the target with the method, the experimental results demonstrate that our proposed method is not only efficient due to the optimization, but effective and accurate in recognizing the target for UAV.

关键词： biological vision space variant resolution mechanism (SVR) log-polar transformations (LPT) pigeon-inspiredoptimization (PIO) object recognition

Structural controllability of multi-agent systems with absolute protocol under fixed and switching topologies

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2017年第9期60卷 226-240页

作者： Yongqiang guan long WANG Center for Complex Systems School of Mechano-Electronic EngineeringXidian University Center for Systems and Control College of Engineering Peking University

The paper investigates the structural controllability of leader-follower multi-agent systems under fixed and switching topologies. Three models of agents: double-integrator, high-order integrator and generallinear dynamics are analyzed. Necessary and sufficient graphical conditions are provided for structural controllability based on communication topology of the system. In particular, a linear neighbor-based control protocol is designed for generic linear agents under which structural controllability is proved to be uniquely determined by communication topology structure. The role that leaders play in the structural controllability of multi-agent system is characterized, and a method is developed to realize structural controllability under single leader. The results clearly indicate the role of leaders and the effect of communication topology on structural controllability.

关键词： multi-agent systems structural controllability absolute protocol leader-follower connectedness switching topology