检索结果-南通市图书馆

Electrical property of 8-mol% yttria-stabilized zirconia electrolyte by spark-plasma sintering

science{1.(Technological sciences) 2004年第5期47卷 569-576页

作者： jian jiawen1,2, chang Aimin3, yang bangchao2.& zhang yikang4 1. The school of information science engineering, ningbo university, ningbo 3.52.1, china 2. The school of Microelectronics and Solid-state Electronics, university of Electronic science and Tech-nology of china, Chengdu 610054, china 3. The Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of sciences, Urumqi 830022, china 4. Hongtak (Chengdu) Electronic Co., Ltd, Chengdu 610041, china Correspondence should be addressed to jian jiawen 1. The school of {1. {2. engineering Ningbo University 315211 Ningbo China 2. The {1. of Microelectronics and Solid-state Electronics University of Electronic Science and Technology of China 610054 Chengdu China 3. The Xinjiang Technical Institute of Physics and Chemistry Chinese Academy of Sciences 830022 Urumqi China 4. Hongtak (Chengdu) Electronic Co. Ltd 610041 Chengdu China

Spark-plasma sintering (SPS) process was used to sinter ZrO2.(8Y) powders, and a relative density of 99% has been reached at a low temperature (1.50°C) and short dwelling time (1. min) compared to the conventional sintered identical samples (1.50°C 4 h)(CS). By the X-ray diffraction (XRD) patterns, the microstructure of the SPS pellet and CS pellet are both indexed by the cubic unit cell (Fm3m). The finer crystallite size (D1.1. of the SPS pellet is 1.4 nm and D1.1.of the CS pellet is more than 1.μm. The AC impedance spectroscopy shows that the ionic conductivity of SPS pellet is different from that of CS pellet. The activation energy for the SPS ceramics, estimated from the slope in the range of 400–800°C, was 91.kJ mol?1. which is in good agreement with CS pellet (96 kJ mol?1., indicating that the conduction mechanism in SPS ceramics is similar to that in CS ceramics.

关键词： yttria-stabilized zirconia electrolyte, spark-plasma sintering, AC impedance.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Stepped-up development of accelerator mass spectrometry method for the detection of ^(60)Fe with the HI-1. tandem accelerator

引用

Nuclear science and Techniques 2024年第4期35卷 136-143页

作者： yang zhang Sheng-Quan Yan Ming He Qing-zhang Zhao Wen-Hui zhang Chao-Xin Kan jian-Ming Zhou Kang-Ning Li Xiao-Fei Wang jian-Cheng Liu Zhao-Hua Peng Zhuo Liang Ai-Ling Li jian Zheng Qi-Wen Fan Yun-Ju Li You-Bao Wang Zhi-Hong Li yang-Ping Shen Ding Nan Wei Nan Yu-Qiang zhang Jia-Ying-Hao Li Jun-Wen Tian jiang-Lin Hou chang-Xin Guo Zhi-Cheng zhang Ming-Hao Zhu Yu-Wen Chen Yu-Chen jiang Tao Tian Jin-Long Ma Yi-Hui Liu Jing-Yu Dong Run-Long Liu Mei-Yue-Nan Ma Yong-Shou Chen Wei-Ping Liu Bing Guo china Institute of Atomic Energy P.O.Box 275(10)Beijing 102413China College of science Southern University of Science and TechnologyShenzhen 518055China school of Physics Xi’an Jiaotong UniversityXi’an 710049China

The Moon provides a unique environment for investigating nearby astrophysical events such as *** samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides such as^(60)*** this work,we stepped up the development of an accelerator mass spectrometry(AMS)method for detecting^(60)Fe using the HI-1.tandem accelerator at the{1. Institute of Atomic Energy(CIAE).Since interferences could not be sufficiently removed solely with the existing magnetic systems of the tandem accelerator and the following Q3D magnetic spectrograph,a Wien filter with a maximum voltage of±60 kV and a maximum magnetic field of 0.3 T was installed after the accelerator magnetic systems to lower the detection background for the low abundance nuclide^(60)Fe.A 1.m thick Si_(3)N_(4) foil was installed in front of the Q3D as an energy *** particle detection,a multi-anode gas ionization chamber was mounted at the center of the focal plane of the ***,an^(60)Fe sample with an abundance of 1.1.2}×1.^(-1.)was used to test the new AMS *** results indicate that^(60)Fe can be clearly distinguished from the isobar^(60)*** sensitivity was assessed to be better than 4.3×1.^(-1.)based on blank sample measurements lasting 5.8 h,and the sensitivity could,in principle,be expected to be approximately 2.5×1.^(-1.)when the data were accumulated for 1.0 h,which is feasible for future lunar sample measurements because the main contaminants were sufficiently separated.

关键词： Accelerator mass spectrometry Wien filter Isobar separation Supernovae chang'e-5 lunar samples

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Pathological significance of tRNA-derived small RNAs in neurological disorders

引用

Neural Regeneration Research 2020年第2期15卷 212-221页

作者： Chuan Qin Pei-Pei Xu Xin zhang Chao zhang {2.-Bin Liu De-Gang yang Feng Gao Ming-Liang yang Liang-Jie Du jian-Jun Li school of Rehabilitation Medicine Capital Medical UniversityBeijingChina china Rehabilitation {1. Institute BeijingChina Center of Neural Injury and Repair Beijing Institute for Brain DisordersBeijingChina Department of Spinal and Neural Functional Reconstruction China Rehabilitation Research CenterBeijingChina Beijing Key Laboratory of Neural Injury and Rehabilitation BeijingChina

Non-coding RNAs(ncRNAs) are a type of RNA that is not translated into proteins. Transfer RNAs(tRNAs), a type of ncRNA, are the second most abundant type of RNA in cells. Recent studies have shown that tRNAs can be cleaved into a heterogeneous population of ncRNAs with lengths of 1.–40 nucleotides, known as tRNA-derived small RNAs(tsRNAs). There are two main types of tsRNA, based on their length and the number of cleavage sites that they contain: tRNA-derived fragments and tRNA-derived stress-induced RNAs. These RNA species were first considered to be byproducts of tRNA random cleavage. However, mounting evidence has demonstrated their critical functional roles as regulatory factors in the pathophysiological processes of various diseases, including neurological diseases. However, the underlying mechanisms by which tsRNAs affect specific cellular processes are largely unknown. Therefore, this study comprehensively summarizes the following points:(1. The biogenetics of tsRNA, including their discovery, classification, formation, and the roles of key enzymes.(2. The main biological functions of tsRNA, including its miRNA-like roles in gene expression regulation, protein translation regulation, regulation of various cellular activities, immune mediation, and response to stress.(3) The potential mechanisms of pathophysiological {1.es in neurological diseases that are regulated by tsRNA, including neurodegeneration and neurotrauma.(4) The identification of the functional diversity of tsRNA may provide valuable information regarding the physiological and pathophysiological mechanisms of neurological disorders, thus providing a new reference for the clinical treatment of neurological diseases. Research into tsRNAs in neurological diseases also has the following challenges: potential function and mechanism studies, how to accurately quantify expression, and the exact relationship between tsRNA and miRNA. These challenges require future research efforts.

关键词： epigenetics molecular biology neurological disorders review sequencing stress tRNA tRNA-derived fragments tRNA-derived small RNAs tRNA-derived stress-induced RNA

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dynamic correlation of diffusion tensor imaging and neurological function scores in beagles with spinal cord injury

引用

Neural Regeneration Research 2018年第5期13卷 877-886页

作者： chang-Bin Liu De-Gang {1. Qian-Ru Meng Da-Peng Li Ming-Liang {1. Wei Sun Wen-Hao zhang chang Cai Liang-Jie Du Jun Li Feng Gao Yan Yu Xin zhang Zhen-Tao Zuo jian-Jun Li school of Rehabilitation Medicine Capital Medical University Department of Spinal and Neural Function Reconstruction China Rehabilitation Research Center Center of Neural Injury and Repair Beijing Institute for Brain Disorders China Rehabilitation Science Institute Beijing Key Laboratory of Neural Injury and Rehabilitation Beijing China State Key Laboratory of Brain and Cognitive science Institute of Biophysics Chinese Academy of Sciences Beijing ChinaThe Innovation Center of Excellence on Brain Science Chinese Academy of Sciences Sino-Danish College University of Chinese Academy of Sciences Beijing China

Exploring the relationship between different structure of the spinal cord and functional assessment after spinal cord injury is important. Quantitative diffusion tensor imaging can provide information about the microstructure of nerve tissue and can quantify the pathological damage of spinal cord white matter and gray matter. In this study, a custom-designed spinal cord contusion-impactor was used to damage the T_（1.） spinal cord of beagles. Diffusion tensor imaging was used to observe {1.es in the whole spinal cord, white matter, and gray matter, and the Texas Spinal Cord Injury Score was used to assess {1.es in neurological function at 3 hours, 2. hours, 6 weeks, and 1.3}weeks after injury. With time, fractional anisotropy values after spinal cord injury showed a downward trend, and the apparent diffusion coefficient, mean diffusivity, and radial diffusivity first decreased and then increased. The apparent diffusion-coefficient value was highly associated with the Texas Spinal Cord Injury Score for the whole spinal cord（R = 0.91., P = 0.02.）, white matter（R = 0.932. P = 0.02.）, and gray matter（R = 0.882. P = 0.048）. Additionally, the other parameters had almost no correlation with the score（P 〉 0.05）. In conclusion, the highest and most significant correlation between diffusion parameters and neurological function was the apparent diffusion-coefficient value for white matter, indicating that it could be used to predict the recovery of neurological function accurately after spinal cord injury.

关键词： nerve regeneration spinal cord injury diffusion tensor imaging fractional anisotropy apparent diffusion coefficient white matter gray matter Texas Spinal Cord Injury Score beagles neural regeneration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mott Transition and Superconductivity in Quantum Spin Liquid Candidate NaYbSe2

引用

Chinese Physics Letters 2020年第9期37卷 89-94页

作者： Ya-Ting Jia Chun-Sheng Gong Yi-Xuan Liu jian-Fa Zhao Cheng Dong Guang-{1. Dai Xiao-Dong Li He-{2. Lei Run-Ze Yu Guang-Ming zhang {2.-Qing Jin Institute of Physics Chinese Academy of SciencesBeijing 100190China university of Chinese Academy of {1.s Beijing 100190China Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials&Micro-nano Devices Ren min University of ChinaBeijing 100872China Peking university Shenzhen Graduate {1. School of Advanced MaterialsShenzhen 518055China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics Tsinghua UniversityBeijing 100084China Frontier science Center for Quantum {1. Beijing 100084China

The Mott transition is one of the fundamental issues in condensed matter physics,especially in the system with antiferromagnetic long-range ***,such a transition is rare in quantum spin liquid(QSL)systems without long-range *** we report the experimental pressure-induced insulator to metal transition followed by the emergence of superconductivity in the QSL candidate NaYbSe2.with a triangular lattice of 4 f Yb^3+*** analysis of transport properties in metallic state shows an evolution from non-Fermi liquid to Fermi liquid behavior when approaching the vicinity of *** irreversible structure phase transition occurs around 1. GPa,which is revealed by the x-ray *** results shed light on the Mott transition in the QSL systems.

关键词： diffraction. transition Fermi

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Two-Dimensional NiMoO_(4)Nanowire Electrode for the Sensitive Determination of Hydroquinone in Four Types of Actual Water Samples

引用

Journal of Analysis and Testing 2022年第4期6卷 382-392页

作者： Li-Wei Bai Yu-Fen Shi Xue zhang Xue-Bo Liu Feng Wu {1. Liu {2.-Feng Jia Wen-Bo Lu Key Laboratory of Magnetic Molecules and Magnetic information Materials(Ministry of Education) School of Chemistry and Material ScienceShanxi Normal UniversityTaiyuan030031China school of Medicine Jiangsu UniversityZhenjiang212013China school of Grain {1. and Technology Jiangsu University of Science and TechnologyZhenjiang212000China

Hydroquinone(HQ)poses immeasurable risk to human health and the natural environment on the grounds of high toxicity of organic phenolic ***,an innovative electrochemical sensor based on two-dimensional nickel molybdate nanowires(NiMoO_(4)NWs)is constructed for the ultra-sensitive determination of HQ,which can provide useful reference for the human health and environment ***-dimensional NiMoO_(4)NWs are prepared successfully through a facile hydrothermal reaction and annealing *** obtained two-dimensional NiMoO_(4)NWs are characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),high-resolution TEM(HRTEM),energy-dispersive X-ray spectroscopy(EDS)mapping and X-ray photoelectron spectroscopy(XPS).The accurate contents of Ni and Mo have been characterized by inductively coupled plasma atomic emission spectroscopy(ICP-AES),confirming that the lower content of the nickel in NiMoO_(4)NWs possesses the higher catalytic activity of *** the optimized conditions,the constructed HQ sensor exhibits satisfactory electrocatalytic activity with a low detection limit of 0.0355μmol/L(S/N=3),a wide linear range of 0.05-4600μmol/L and sensitivity of 1.0.064μA/(mmol cm^(2.).The sensor has been successfully applied to the detection of HQ in rainwater,tap water,domestic sewage and drinking water samples with satisfactory *** the same time,this sensor has excellent reproducibility,selectivity,and *** constructed sensor has potential practical application value and broad application prospect in human health and environmental monitoring.

关键词： NiMoO_(4)nanowire Electrochemical sensor Hydroquinone Actual water samples

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mineralogy of chang'e-4 landing site:preliminary results of visible and near-infrared imaging spectrometer

引用

science{1.({2. sciences) 2020年第4期63卷 195-206页

作者： jian CHEN Zongcheng LING Le QIAO Zhiping HE Rui XU Lingzhi SUN jiang {2. Bo LI Xiaohui FU changqing LIU Xiaobin QI Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment School of Space Science and PhysicsInstitute of Space Sciences Shandong University Key Laboratory of Space Active Opto-Electronics Technology Shanghai Institute of Technical PhysicsChinese Academy of Sciences Hawai'i Institute of Geophysics and Planetology Department of Earth Sciences University of Hawai'i at Manoa

The exploration of mafic anomaly in South Pole-Aitken(SPA, the largest confirmed) basin on the Moon provides important insights into lunar interior. The landing of chang’e-4(CE-4) and deployment of Yutu-{1.rover on the discontinuous ejecta from Finsen crater enabled in-situ measurements of the unusual mineralogy in the central portion of SPA basin with visible and near-infrared imaging spectrometer(VNIS).Here we present detailed processing procedures based on the level {1. data of CE-4 VNIS and preliminary mineralogical results at the exploration area of Yutu-{1.rover. A systematic processing pipeline is developed to derive credible reflectance spectra, based on which several spectral and mineral indices are calculated to constrain the mafic mineralogy. The mafic components in the soils and boulder around CE-4 landing site are concluded as clinopyroxene-bearing with intermediate composition and probably dominated by pigeonite although the possibility of mixing orthopyroxen(OPX) and calcic clinopyroxene(CPX) also exists. These mineralogical results are more consistent with a petrogenesis that the CE-4 regolith and rock fragment are derived from rapid-cooling magmatic systems and we interpret that the materials at the CE-4 landing site ejected from Finsen crater are probably recrystallized from impact melt settings.

关键词： chang’e-4 visible and near-infrared spectroscopy mineralogy impact melt the Moon

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

工作记忆训练诱发的神经可塑性——基于系列fMRI实验的脑区分布递减时空模型

引用

心理科学进展 2022年第2期30卷 255-274,I0002-I0005页

作者：陈幸明付彤刘昌张宾伏云发李恩泽 zhang {1. 陈盛强党彩萍广州医科大学附属脑科医院广州510370 广州医科大学卫生管理学院广州511436 南京师范大学心理学院南京210024 昆明理工大学信息工程与自动化学院昆明理工大学医学院昆明650031 南方医科大学南方医院精神心理科广州510515 天津医科大学天津300070

工作记忆训练(Working Memory Training,WMT)诱发神经可塑性,但其具体机制尚不明晰。为探索WMT改变正常人群大脑功能的时空特性,以"扩展的智力顶额整合理论"和"神经效率假说"为依据,采用逐层递进的5种方法,分6个步骤来查究近2.年来正常... 详细信息

工作记忆训练(Working Memory Training,WMT)诱发神经可塑性,但其具体机制尚不明晰。为探索WMT改变正常人群大脑功能的时空特性,以"扩展的智力顶额整合理论"和"神经效率假说"为依据,采用逐层递进的5种方法,分6个步骤来查究近2.年来正常人群WMT的37篇fMRI文献。第一步,用叙述性综述、频数分析和卡方检验法比较脑区激活模式和脑网络功能连接在WMT前后发生的改变,发现WMT改变了大脑的5个联合区、7个宏观区和3个子区。其中,额上回、顶下小叶和扣带回这3个子区各自激活减弱的报道文献数量多于其激活增强的,且这种差异分别具有统计学意义。第二步,采用激活似然估计法对其中2.篇开展元分析,发现大脑的3个子区激活减弱水平在WMT前后的差异具有统计学意义,即额中回(BA6和8)、额上回(BA6)和前扣带回(BA2.和32.。第三步,综合定性和定量分析结果,提出WMT脑区分布递减时空模型,产生5个结果和讨论。第四步,采用非参数检验进一步追踪WMT效应的调节因素,发现训练的任务类型和时间分别对脑区激活的影响具有统计学意义。第五步,针对正常人群WMT诱发神经可塑性的时空特性,得出3个结论:第一, WMT改变了正常人群相应脑区的神经活动,表现为减弱或增强,但减弱更加突出,且更新和较短时间的WMT倾向于诱发较多减弱;第二,这些神经活动变化主要发生在额顶叶联合区,但也包括分别以颞叶、枕叶、扣带回及纹状体为主的联合区,在一定范围内体现了整脑功能联合。这体现了WMT诱发神经可塑性的空间特性,且符合"扩展的智力顶额整合理论";第三,额中回、额上回、顶下小叶和扣带回(尤其前扣带回)这4个子区在激活减弱水平上重点展示了WMT神经可塑性的时间特性,且符合"神经效率假说",恰好体现出"聪明的大脑更懒惰"。第六步,指出WMT诱发神经可塑性的未来研究可能关注脑可塑性中的低活跃性、辨析额中回、额上回、顶下小叶和扣带回(尤其前扣带回)这4个子区在激活减弱水平上体现的时间特性、找寻训练减弱或增强大脑活动的综合性影响因素。

关键词：工作记忆训练神经可塑性脑区分布递减时空模型额中回额上回前扣带回

来源：

维普期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

基于多特征融合的混凝土结构表面病害图像分类算法

引用

长安大学学报（自然科学版） 2021年第3期41卷 64-74页

作者：杨扬王连发张宇峰韩晓健在役长大桥梁安全与健康国家重点实验室江苏南京210012 长大桥梁健康检测与诊断技术交通行业重点实验室江苏南京210012 江苏省长大桥梁健康监测数据中心江苏南京210012 苏交科集团股份有限公司江苏南京210012 南京工业大学土木工程学院江苏南京211800

为提升混凝土表面开裂、露筋锈蚀和损伤3类病害图像分类效率与准确性,减少人工成本,提出了基于多特征融合的混凝土结构表面病害图像分类算法。该算法通过提取混凝土表面病害图像的纹理特征、灰度直方图特征、颜色特征,以支持向量机(SVM... 详细信息

为提升混凝土表面开裂、露筋锈蚀和损伤3类病害图像分类效率与准确性,减少人工成本,提出了基于多特征融合的混凝土结构表面病害图像分类算法。该算法通过提取混凝土表面病害图像的纹理特征、灰度直方图特征、颜色特征,以支持向量机(SVM)为分类器,分别训练3类特征的病害图像分类模型,采用特征权重算法估计各个特征的权重系数,借助分类模型与权重系数估计病害图像类别划分的可信度值,根据最小误差原则将病害图像判定为可信度值最大的类别。设计了7组覆盖上述图像特征的特征融合方案,以2.00张病害图片为样本,训练了3种单一特征和4种多特征病害图像分类模型,并测试算法的准确性。结果表明:总体上,多特征融合分类模型对于混凝土表面病害图像分类准确率高于单一特征分类模型;基于多项式核函数,灰度+颜色+纹理特征融合分类模型分类效果最佳,平均分类准确率达到84%,较单一特征分类模型提升了7%;依赖于混凝土病害图像多特征的综合信息,灰度+颜色+纹理特征融合分类模型可将混凝土表面锈蚀和缺损的分类准确率提升至88%,多特征融合分类模型对于病害的分类判别稳定性显著优于单一特征分类模型。该研究可为混凝土表面病害图像分类提供有效方法,提升病害分类效率与准确性。

关键词：桥梁工程分类算法多特征融合病害图像混凝土结构支持向量机

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

激光稳频技术在大气探测激光雷达中的应用研究进展

引用

计量学报 2023年第2期44卷 186-194页

作者：黄聪张圣梓王将常建华南京信息工程大学电子与信息工程学院江苏南京210044 中国计量科学研究院北京100029

大气探测激光雷达因其时空分辨率高、探测精度高等特点,在大气探测、环境监测、国防安全等研究领域应用广泛。根据大气探测激光雷达的测量原理,其光源的频率稳定性会对大气参数的测量和反演产生巨大影响,因此,对光源进行稳频尤为重要。... 详细信息

大气探测激光雷达因其时空分辨率高、探测精度高等特点,在大气探测、环境监测、国防安全等研究领域应用广泛。根据大气探测激光雷达的测量原理,其光源的频率稳定性会对大气参数的测量和反演产生巨大影响,因此,对光源进行稳频尤为重要。综述了目前应用于大气探测激光雷达的4种激光稳频技术及特点,介绍了这些稳频技术在大气探测激光雷达中的应用研究现状,为未来研制高精度大气探测激光雷达提供参考和借鉴。

关键词：计量学大气探测激光雷达激光稳频大气参数

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：