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Transient acceleration in f(T) gravity

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Research in Astronomy and Astrophysics 2016年第2期16卷 13-18页

作者： jing-zhao qi Rong-Jia Yang Ming-Jian Zhang Wen-Biao Liu Department of Physics Institute of Theoretical Physics Beijing Normal University College of Physical Science and Technology Hebei University

Recently an f （T） gravity based on the modification of teleparallel gravity was proposed to ex-plain the accelerated expansion of the universe. We use observational data from type Ia supernovae, baryon acoustic oscillations, and cosmic microwave background to constrain this f（T） theory and reconstruct the effective equation of state and the deceleration parameter. We obtain the best-fit values of parameters and find an interesting result that the constrained f（T） theory allows for the accelerated Hubble expansion to be a transient effect.

关键词： f(T) gravity cosmology -- reconstruction -- observation

What do parameterized Om(z) diagnostics tell us in light of recent observations?

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Research in Astronomy and Astrophysics 2018年第6期18卷 49-58页

作者： jing-zhao qi Shuo Cao Marek Biesiada Teng-Peng Xu Yan Wu Si-Xuan Zhang Zong-Hong Zhu Department of Astronomy Beijing Normal University Department of Astrophysics and Cosmology Institute of Physics University of Silesia

In this paper, we propose a new parametrization for Om(z) diagnostics and show how the most recent and significantly improved observations concerning the H(z) and SN Ia measurements can be used to probe the consistency or tension between the ΛCDM model and observations. Our results demonstrate that H0 plays a very important role in the consistency test of ΛCDM with H(z)data. Adopting the Hubble constant priors from Planck 2013 and Riess, one finds considerable tension between the current H(z) data and ΛCDM model and confirms the conclusions obtained previously by others. However, with the Hubble constant prior taken from WMAP9, the discrepancy between H(z) data and ΛCDM disappears, i.e., the current H(z) observations still support the cosmological constant scenario. This conclusion is also supported by the results derived from the Joint Lightcurve Analysis(JLA) SN Ia sample. The best-fit Hubble constant from the combination of H(z)+JLA(H00 = 68.81+1.5-1.49 km s-1 Mpc-1) is very consistent with results derived both by Planck 2013 and WMAP9, but is significantly different from the recent local measurement by Riess.

关键词： cosmology: theory cosmology: observations cosmology: cosmological parameters

Null test for cosmic curvature using Gaussian process

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Chinese Physics C 2023年第5期47卷 259-270页

作者：武鹏举祁景钊张鑫 Key Laboratory ofCosmology and Astrophysics(Liaoning Province)&Department of Physics College of SciencesNortheastern UniversityShenyang 110819China Key Laboratory of Data Analytics and Optimization for Smart Industry(Ministry of Education) Northeastern UniversityShenyang 110819China National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern UniversityShenyang 110819China

The cosmic curvature Ω_(K,0),which determines the spatial geometry of the universe,is an important parameter in modern *** deviation from Ω_(K,0)=0 would have a profound impact on the primordial inflation paradigm and fundamental *** this work,we adopt a cosmological model-independent method to test whether Ω_(K,0) deviates from *** use the Gaussian process to reconstruct the reduced Hubble parameter E(z)and the derivative of the distance D'(z)from observational data and then determine Ω_(K,0) with a null test *** cosmic chronometer(CC)Hubble data,baryon acoustic oscillation(BAO)Hubble data,and supernovae Pantheon sample are *** result is consistent with a spatially flat universe within the domain of reconstruction 01,it tends to favor a closed *** this sense,there is still a possibility for a closed *** also carry out the null test of the cosmic curvature at 0

关键词： cosmic curvature Gaussian process cosmological observations cosmological model-independent method null test

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闭合宇宙的新观测证据与宇宙学的危机

科学通报 2019年第36期64卷 3773-3775页

作者：祁景钊张鑫东北大学理学院物理系

宇宙学的研究已经进入到一个精确宇宙学时代.普朗克卫星以前所未有的精度精确测量了宇宙微波背景辐射(cosmic microwave background,CMB)上的微小温度涨落和极化,这些测量结果为宇宙学参数提供了强有力的限制[1].总体来说,普朗克观测结... 详细信息

宇宙学的研究已经进入到一个精确宇宙学时代.普朗克卫星以前所未有的精度精确测量了宇宙微波背景辐射(cosmic microwave background,CMB)上的微小温度涨落和极化,这些测量结果为宇宙学参数提供了强有力的限制[1].总体来说,普朗克观测结果明确支持一个仅含有6个基本宇宙学参数的宇宙学模型,即所谓的宇宙学常数冷暗物质(߉cold dark matter,߉CDM)模型.目前,空间平直的߉CDM模型被普遍视为一个宇宙学的标准模型,因为该模型的预言与几乎所有的宇宙学观测都符合得很好.

关键词：宇宙学宇宙微波背景辐射冷暗物质普朗克标准模型温度涨落

δ-phase precipitation regularity of cold-rolled fine-grained GH4169 alloy plate and its effect on mechanical properties

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Transactions of Nonferrous Metals Society of China 2020年第12期30卷 3287-3295页

作者： Hao XUE jing-qi zhao Yong-kang LIU Chun-xiang ZHANG Jun-ting LUO Key Laboratory of Advanced Forging&Stamping Technology and Science of Ministry of Education Yanshan UniversityQinhuangdao 066004China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China

Cold rolling and heat-treatment were used for the grain refinement of GH4169 superalloy *** effects of cold rolling reduction ratio and heat-treatment time on the precipitatedδphase,and the effects ofδ-phase content and morphology on the mechanical properties of the GH4169 alloy plates,are *** results demonstrate that coldrolling can promote the precipitation of theδphase and its transformation from theδ-Ni3Nb phase to theδ-NbNi4 *** comprehensive properties of the alloy are better when the heat treatment time is 1 h,with 132 MPa increase in the tensile strength and only 2.9%decrease in the elongation relative to those of the original *** mechanical properties of the alloy are shown to change greatly with the change in theδ-phase morphology.

关键词： fine-grained GH4169 alloy cold rolling δphase mechanical properties

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国家技术创新工程试点省份安徽概况及其启示

科学管理研究 2015年第1期33卷 68-71页

作者：沙其富赵菁奇安徽中澳科技职业学院安徽合肥230031 安徽省委党校安徽合肥230022

安徽通过建立组织保障、制度保障、产学研合作保障和科研平台保障,有力提升了全省技术创新投入产出水平,但同时也存在专项资金监督检查机制不健全、企业优惠政策落实不全面、产学研合作考核评价体系不完善、技术创新服务平台投入不足等... 详细信息

安徽通过建立组织保障、制度保障、产学研合作保障和科研平台保障,有力提升了全省技术创新投入产出水平,但同时也存在专项资金监督检查机制不健全、企业优惠政策落实不全面、产学研合作考核评价体系不完善、技术创新服务平台投入不足等问题。因此,建立健全监督检查机制、加大创新型企业扶持力度、制定产业技术创新战略联盟考核办法、增加技术创新服务平台建设投入等措施,将有助于推进安徽省技术创新体系建设。

关键词：技术创新投入产出保障措施

Lipid droplets in the nervous system:involvement in cell metabolic homeostasis

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Neural Regeneration Research 2025年第3期20卷 740-750页

作者： Yuchen Zhang Yiqing Chen Cheng Zhuang jingxuan qi Robert Chunhua zhao Jiao Wang School of Life Sciences Shanghai UniversityShanghaiChina School of Medicine Shanghai UniversityShanghaiChina Institute of Basic Medical Sciences Chinese Academy of Medical Sciences School of Basic MedicinePeking Union Medical CollegeBeijingChina Center of Excellence in Tissue Engineering Chinese Academy of Medical SciencesBeijingChina Beijing Key Laboratory of New Drug Development and Clinical Trial of Stem Cell Therapy BeijingChina

Lipid droplets serve as primary storage organelles for neutral lipids in neurons,glial cells,and other cells in the nervous *** droplet formation begins with the synthesis of neutral lipids in the endoplasmic ***,lipid droplets were recognized for their role in maintaining lipid metabolism and energy homeostasis;however,recent research has shown that lipid droplets are highly adaptive organelles with diverse functions in the nervous *** addition to their role in regulating cell metabolism,lipid droplets play a protective role in various cellular stress ***,lipid droplets exhibit specific functions in neurons and glial *** of lipid droplet formation leads to cellular dysfunction,metabolic abnormalities,and nervous system *** review aims to provide an overview of the role of lipid droplets in the nervous system,covering topics such as biogenesis,cellular specificity,and ***,it will explore the association between lipid droplets and neurodegenerative *** the involvement of lipid droplets in cell metabolic homeostasis related to the nervous system is crucial to determine the underlying causes and in exploring potential therapeutic approaches for these diseases.

关键词： Alzheimer's disease lipid droplet biogenesis lipid droplets lipid metabolism nervous system neurodegenerative disorders oxidative stress Parkinson's disease

Flexible molecules dedicate to release strain of inverted inorganic perovskite solar cell

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Journal of Energy Chemistry 2025年第1期100卷 87-93页

作者： Hongrui Sun Sanlong Wang Pengyang Wang Yali Liu Shanshan qi Biao Shi Ying zhao Xiaodan Zhang Institute of Photoelectronic Thin Film Devices and Technology Renewable Energy Conversion and Storage Center State Key Laboratory of Photovoltaic Materials and CellsNankai University Key Laboratory of Photoelectronic Thin Film Devices and Technology of Tianjin Haihe Laboratory of Sustainable Chemical Transformations Engineering Research Center of Thin Film Photoelectronic Technology of Ministry of Education Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)

The tensile strain in inorganic perovskite films induced by thermal annealing is one of the primary factors contributing to the inefficiency and instability of inorganic perovskite solar cells （IPSCs）,which reduces the defect formation ***,a flexible molecule 5-maleimidovaleric acid （5-MVA） was introduced as a strain buffer to release the residual strain of *** anhydride and carboxyl groups in 5-MVA interact strongly with the uncoordinated Pb2+through Lewis acid-base reaction,thus tightly“pull”the perovskite *** in-between soft carbon chain increased the structural flexibility of CsPbI2.85Br0.15perovskite materials,which effectively relieved the intrinsic internal strain of CsPbI2.85Br0.15,resisted the corrosion of external strain,and also reduced the formation of defects such as VIand *** addition,the introduction of 5-MVA improved crystal quality,passivated residual defects,and narrowed energy level ***,power conversion efficiency （PCE） of NiOxbased inverted IPSCs increased from 19.25% to 20.82% with the open-circuit voltage enhanced from 1.164 V to 1.230 *** release of strain also improved the stability of CsPbI2.85Br0.15perovskite films and devices.

关键词： Perovskite solar cells

混合型肝癌的多期增强影像表现及与其他类型原发性肝癌的比较

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中国医学影像技术 2017年第2期33卷 212-216页

作者：陈枫李宏军赵晶齐石夏振营赵大伟首都医科大学附属北京佑安医院放射科北京100069

目的探讨混合型肝癌(cHCC-CC)的CT、MRI多期增强影像表现,并与其他类型原发性肝癌对比分析。方法回顾性分析25例经病理证实的cHCC-CC的多期增强影像表现,并依据临床及影像表现分别与200例普通类型肝细胞癌(HCC)、51例硬化型肝癌(SHCC)、... 详细信息

目的探讨混合型肝癌(cHCC-CC)的CT、MRI多期增强影像表现,并与其他类型原发性肝癌对比分析。方法回顾性分析25例经病理证实的cHCC-CC的多期增强影像表现,并依据临床及影像表现分别与200例普通类型肝细胞癌(HCC)、51例硬化型肝癌(SHCC)、104例肝内肿块型胆管癌(IMCC)进行比较,分析其差异。结果 cHCC-CC的多期增强强化方式主要分为3种:动脉期肿瘤呈整体不均匀强化,平衡期仍见持续不均匀强化(n=12);动脉期肿瘤呈不均匀强化,平衡期对比剂流出,呈低密度/低信号改变(n=8);动脉期肿瘤呈边缘环状强化,平衡期对比剂呈环状或不规则状向内填充(n=5)。cHCC-CC在年龄、性别、病毒性肝炎病史、血管受侵及淋巴结转移与HCC、SHCC、IMCC差异无统计学意义(P均>0.05),而与IMCC比较,cHCC-CC更常见于肝硬化患者(P<0.001)。cHCC-CC邻近肝包膜皱缩的发生率明显低于SHCC和IMCC(P=0.021、0.005),AFP与CA19-9升高的比例与IMCC差异有统计学意义(P=0.005、0.001)。结论 cHCC-CC是原发性肝癌的少见类型,其影像及临床表现与HCC、SHCC及IMCC既重合,又有其特征性,准确诊断有助于临床治疗方案的选择和对预后的判断。

关键词：肝脏肿瘤体层摄影术,X线计算机磁共振成像