检索结果-南通市图书馆

Model eyes with curved multilayer structure for the axial resolution evaluation of an ophthalmic optical coherence tomography device

引用

Journal of Innovative Optical Health Sciences 2018年第3期11卷 65-71页

作者： Zhenggang Cao Zengqian Ding zhixiong Hu wen Qiao wenli Liu Xiaojun Chen National Institute of Metrology Division of Medical and Biological MeasurementsBeijing 100029P.R.China Optoelectronics and Energy&Collaborative Innovation Center of Suzhou Nano Science and Technology College of Physics Soochow UniversitySuzhou 215006P.R.China Key Laboratory of Advanced Optical Manufacturing Technologies of Jiangsu Province and Key Laboratory of Modern Optical Technologies of Education Ministry of China Soochow University Suzhou 215006P.R.China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240P.R.China

Optical coherence tomography(OCT)has been widely applied to the diagnosis of eye diseasesduring the past two ***,valid evaluation methods are stil not available for theclinical OCT *** order to assess the axial resolution of the OCT system,standard modeleyes with micro-scale multilayer structure have been designed and manufactured in this *** a natural human eye,proper Titanium dioxide(TiO_(2))materials of particles withdifferent concentrations were selected by testing the scattering coefficient of PDMS *** artificial retinas with multilayer films were fabricated with the thicknesses from 9.5 to 30 micrometers using spin coating technology,Subsequently,standard OCT model eyes were ac-complished by embedding the retina phantoms into the artificial frames of *** ease ofmeasurement processing,a series of model eyes were prepared,and each contained flms withthree kinds of *** the traceability and accuracy of the key parameters of the standard model eyes,the thicknesses of multilayer structures were verfed using ThicknessMonitoring *** the experiment with three different OCT devices,it demonstratedthe model eyes fabricated in this study can provide an effective evaluation method for the axialresolution of an ophthalmic OCT device.

关键词： Optical coherence tomography metrology optical standards and testing spin coating

来源：

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

Comparison of global DNA methylation profiles in replicative versus premature senescence

Comparison of global DNA methylation profiles in replicative...

引用

中国毒理学会生化与分子毒理专业委员会第六届全国学术会议、中国毒理学会遗传毒理专业委员会第五届全国学术会议、广东省预防医学会卫生毒理专业委员会学术会议、广东省环境诱变剂学会学术会议

作者： wen juan Zhang~(a,b) Weidong Ji~(a,b,c) Jianping Yang~a Linqing Yang~b Jianhui Yuan~b Yuling Xu~(a,b) Wei Xu~(a,b) wen Chen~a zhixiong Zhuang~(b,*) ~a School of Public Health,Sun Yet-sen University,74 Zhongshan Road 2,Guangzhou 510080,P.R.China ~b Shenzhen Center for Disease Control and Prevention,21 Tianbei Road 1,Shenzhen 518020,P.R.China:~c Institute for Chemical Carcinogenesis,Guangzhou Medical College,195 Dongfeng Xi Road,Guangzhou 510182,P.R.China

DNA methylation is considered to play an essential role in cellular senescence. To uncover the mechanism underlying cellular senescence,we established the model of premature senescence induced by hydrogen peroxide （HO） in human embryonic lung fibroblasts and investigated the changes of genome methylation,DNA methyltransferases （DNMTs） and DNA-binding domain proteins （MBDs） in comparison with those observed during normal replicative *** found that premature senescence triggered by HO exhibited distinct morphological characteristics and proliferative capacity which were similar to those of replicative *** genome methylation level decreased gradually during the premature as well as replicative senescence,which was associated with the reduction in the expression of DNMTI,reflecting global hypomethylation as a distinct feature of senescent *** levels of DNMT3b and methyl-CpG binding protein 2 （MeCP2） increased in both mid-aged and replicative senescent cells,while DNMT3a and MBD2 were upregulated in the mid-aged *** DNMT3b was elevated in the cells in the premature senescence persistence ***,the expression for DNMTs, MBD2 and MeCP2 was increased rapidly upon HO *** results indicate that HO-induced premature senescence share some features of replicative senescence,such as basic biological characteristics and global hypomethylation while there are slight differences in the profile of methylation-associated enzyme *** damage may hence be a causative factor in epigenetic alteration partly responsible for cellular senescence.

关键词： methylation senescence methyltransferases hydrogen peroxide

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Thermal–moisture dynamics and thermal stability of active layer in response to wet/dry conditions in the central region of the Qinghai–Tibet Plateau,China

引用

Research in Cold and Arid Regions 2023年第1期15卷 27-38页

作者： MingLi Zhang zhixiong Zhou Zhi wen FengXi Zhou Zhao Ma BingBing Lei College of Civil Engineering Lanzhou University of TechnologyLanzhouGansu 730050China State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environmental and ResourcesChinese Academy of SciencesLanzhouGansu 730000China Geological Hazards Prevention Institute Gansu Academy of SciencesLanzhouGansu 730000China College of Civil Engineering Lanzhou Jiaotong UniversityLanzhouGansu 730070China

The amount of rainfall varies unevenly in different regions of the Qinghai-Tibet Plateau, with some regions becoming wetter and others drier. Precipitation has an important impact on the process of surface energy balance and the energy-water transfer within soils. To clarify the thermal-moisture dynamics and thermal stability of the active layer in permafrost regions under wet/dry conditions, the verified water-vapour-heat coupling model was used. Changes in the surface energy balance, energy-water transfer within the soil, and thickness of the active layer were quantitatively analyzed. The results demonstrate that rainfall changes significantly affect the Bowen ratio, which in turn affects surface energy exchange. Under wet/dry conditions, there is a positive correlation between rainfall and liquid water flux under the hydraulic gradient;water vapour migration is the main form under the temperature gradient, which indicates that the influence of water vapour migration on thermalmoisture dynamics of the active layer cannot be neglected. Concurrently, regardless of wet or dry conditions,disturbance of the heat transport by conduction caused by rainfall is stronger than that of convection by liquid water. In addition, when rainfall decreases by 1.5 times(212 mm) and increases by 1.5 times(477 mm), the thickness of the active layer increases by 0.12 m and decreases by 0.21 m, respectively. The results show that dry conditions are not conducive to the preservation of frozen soil;however, wet conditions are conducive to the preservation of frozen soil, although there is a threshold value. When this threshold value is exceeded, rainfall is unfavourable for the development of frozen soil.

关键词： Active layer Wet/dry conditions Qinghai-Tibet Plateau(QTP) Thermal-moisture dynamics Permafrost thermal stability Numerical modelling

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

Whistle signal variations among three Indo-Pacific humpback dolphin populations in the South China Sea:a combined effect of the Qiongzhou Strait’s geographical barrier function and local ambient noise?

引用

Integrative Zoology 2021年第4期16卷 499-511页

作者： Jing YUAN Zhitao WANG Pengxiang DUAN Yousheng XIAO Hongke ZHANG zhixiong HUANG Ruichun ZHOU Hua wen Kexiong WANG Ding WANG The Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences Institute of Hydrobiology of the Chinese Academy of SciencesWuhanChina University of Chinese Academy of Sciences BeijingChina Pearl River Estuary Chinese White Dolphin National Nature Reserve ZhuhaiChina National Hepu Dugong Nature Reserve Administration Station BeihaiChina Hong Kong-Zhuhai-Macao Bridge Authority ZhuhaiChina

Geographic variations in the dolphin whistles could be useful in assessing association and isolation among *** of free-ranging Indo-Pacific humpback dolphins(Sousa chinensis)among the Pearl River Estuary(PRE),Leizhou Bei(LZB)and Sanniang Bay(SNB)populations were investigated.A total of 2850 whistles with legible fundamental contour were extracted and 15 acoustic parameters were *** to SNB,PRE and LZB had the same relative proportion of tonal type compositions with flat and sine representing the most frequent *** generalized linear model analysis showed significant acoustic difference among populations and tonal *** frequency parameters in SNB were significantly higher than those in PRE and LZB,where no significant variation was observed in most of the parameters either at the population level or within each tonal *** discriminant functions analysis showed a smaller difference between PRE and LZB than between PRE and SNB and between LZB and *** with previous recordings,recent recordings demonstrated a consistent pattern of becoming higher in whistle frequency parameters in both LZB and SNB populations,suggesting that noise pollution in LZB and SNB increasing with time according to the acoustic niche *** whistle’s geographic variations could be shaped by the combined function of the geographical barrier function of the Qiongzhou strait and local ambient *** the isolated condition and the relatively smaller population size of the humpback dolphin in the SNB,more effective and proactive conservation actions should be taken to prevent the extinction of small populations.

关键词： geographic difference geographical barrier Indo-Pacific humpback dolphins noise whistle

来源：

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

可控冲击波震源技术在陕北沙漠区地震勘探的应用

引用

陕西煤炭 2024年第1期43卷 30-35页

作者：薛海军韩志雄韩军锋汶小岗张永民吴大林陕西省煤田物探测绘有限公司陕西西安710005 自然资源部煤炭资源勘查与综合利用重点实验室陕西西安710021 西安交通大学电力设备电气绝缘国家重点实验室陕西西安710049 西北核技术研究所强脉冲辐射环境模拟与效应国家重点实验室陕西西安710024

针对现有地震勘探震源存在问题和局限性,创新性地将金属丝电爆炸可控冲击波技术应用于地震勘探中,分析了金属丝电爆炸可控冲击波技术和产生原理。在掌握金属丝电爆炸可控冲击波技术作为地震勘探震源技术的特点和陕北沙漠地区进行现场激... 详细信息

针对现有地震勘探震源存在问题和局限性,创新性地将金属丝电爆炸可控冲击波技术应用于地震勘探中,分析了金属丝电爆炸可控冲击波技术和产生原理。在掌握金属丝电爆炸可控冲击波技术作为地震勘探震源技术的特点和陕北沙漠地区进行现场激发试验的情况下,从理论分析和现场试验验证了金属丝电爆炸可控冲击波技术作为震源技术的可行性。通过对获取的数据进行定量分析,认为可控冲击波技术可作为一种新型震源技术,且在陕北沙漠区煤田地震勘探领域具备较好的应用发展前景。同时,通过总结试验中存在的问题,为下一步的改进提供方向。

关键词：地震勘探金属丝电爆炸可控冲击波脉冲功率技术等离子体沙漠区域

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

基于CiteSpace分析中医药治疗慢性心力衰竭的知识图谱

引用

西部中医药 2024年第6期37卷 79-83页

作者：祁祥朱智德卢健棋潘朝锌温志浩蒋志雄蔡宗余广西中医药大学广西南宁530200 河南中医药大学河南郑州450046 广西中医药大学第一附属医院/国家中医心血管病临床医学研究中心分中心广西南宁530200

目的:探讨中医药治疗慢性心力衰竭的研究现状、热点及前沿。方法:检索中国知网(CNKI)2011—2021年有关中医药治疗慢性心力衰竭的相关文献,使用软件CiteSpace 5.7.R5W对检索出的3767篇文献作者的文章发表量、机构合作及分布情况、关键词... 详细信息

目的:探讨中医药治疗慢性心力衰竭的研究现状、热点及前沿。方法:检索中国知网(CNKI)2011—2021年有关中医药治疗慢性心力衰竭的相关文献,使用软件CiteSpace 5.7.R5W对检索出的3767篇文献作者的文章发表量、机构合作及分布情况、关键词共现及聚类进行可视化分析,并绘制知识图谱。结果:该领域近十年发文量呈稳定增长态势,其中核心作者30名,以张艳为代表;研究机构381家,以辽宁中医药大学最为高产;关键词289个“中西医结合疗法”出现频次最高;聚类结果包括目前该领域文献研究类型、该病的中西医常用疗法及干预机制、该病的临床诊断研究。结论:近十年来对中医药治疗慢性心力衰竭的研究呈蓬勃发展态势,且中医特色疗法与心脏康复将是该领域未来的研究热点。

关键词： CiteSpace 文献计量学科学知识图谱可视化分析心力衰竭,慢性中医药

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

基于BP神经网络的齿轮材料热处理工艺优化

引用

热加工工艺 2018年第8期47卷 175-178页

作者：温然金志雄四川长江职业学院

以齿轮材料型号、退火温度、退火时间、淬火温度、淬火时间、回火温度和回火时间7个参数作为输入参数,以耐磨损性能为输出参数,构建出7×35×1三层拓扑结构的齿轮复合材料热处理工艺BP神经网络优化模型,并进行了学习训练、预测验证与应... 详细信息

以齿轮材料型号、退火温度、退火时间、淬火温度、淬火时间、回火温度和回火时间7个参数作为输入参数,以耐磨损性能为输出参数,构建出7×35×1三层拓扑结构的齿轮复合材料热处理工艺BP神经网络优化模型,并进行了学习训练、预测验证与应用验证。结果表明,BP神经网络优化模型的预测能力强,预测精度高,平均预测相对误差为3.6%。与原用热处理工艺相比,齿轮材料在采用BP神经网络优化的热处理工艺后耐磨损性能得到明显提高,其中42CrMo-15%WC磨损体积减小44%,42CrMo-50%WC磨损体积减小58%。

关键词： BP神经网络热处理工艺优化齿轮材料耐磨损性能

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

Identification and characterization of rice blast resistance gene Pid4 by a combination of transcriptomic profiling and genome analysis

引用

Journal of Genetics and Genomics 2018年第12期45卷 663-672页

作者： zhixiong Chen wen Zhao Xiaobo Zhu Chengdong Zou Junjie Yin Mawsheng Chern Xiaogang Zhou Heng Ying Xin Jiang Yongzhen Li Haicheng Liao Mengping Cheng Weitao Li Min He Jing Wang Jichun Wang Bingtian Ma Jirui Wang Shigui Li Lihuang Zhu Xuewei Chen State Key Laboratory of Crop Genetics of Disease Resistance and Disease Control State Key Laboratory of Hybrid RiceKey Laboratory of Major Crop Diseases & Collaborative Innovation Center for Hybrid Rice in Yangtze River BasinRice Research InstituteSichuan Agricultural UniversitySichuan 611130 China Department of Plant Pathology University of CaliforniaDavisCA 95616USA Triticeae Research Institute.Sichuan Agricultural University Sichuan 611130China State Key Laboratory of Plant Genomics National Center for Plant Gene ResearchInstitute of Genetics and Developmental Biology，Chinese Academy of SciencesBeijing 100101China

Map-based cloning of plant disease resistance (R) genes is time-consuming. Here, we reported the isolation of blast R gene Pid4 using comparative transcriptomic profiling and genome-wide sequence analysis. Pid4 encodes a coiled-coil nucleotide-binding site leucine-rich repeat(CC-NBS-LRR) protein and is constitutively expressed at diverse developmental stages in the rice variety Digu. The Pid4 protein is localized in both the nucleus and cytoplasm. Introduction of Pid4 into susceptible rice cultivars confers race-specific resistance to leaf and neck blast. Amino acid sequence comparison and blast resistance spectrum tests showed that Pid4 is a novel R gene, different from the previously reported R genes located in the same gene cluster. A Pid4 Indel marker was developed to facilitate the identification of Pid4 in different rice varieties. We demonstrated that a plant R gene can be quickly isolated using transcriptomic profiling coupled with genome-wide sequence analysis.

关键词： Blast disease Genome-wide sequence analysis Resistance Rice Transcriptome

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

全液压转向特性测试的实验与分析

引用

中国农机化学报 2014年第5期35卷 122-127页

作者：文爱民鲁植雄吴俊淦南京交通职业技术学院汽车工程学院南京市211188 南京农业大学工学院南京市210031

分析全液压转向系统的特性,提出拖拉机全液压转向特性的实验测试方法及传感器在拖拉机上的安装方法,采用labview软件平台设计测试软件,实验测试分别在水泥硬路面与泥土软路面上进行,将所测得的数据导入到Matlab软件中绘制出不同工况下... 详细信息

分析全液压转向系统的特性,提出拖拉机全液压转向特性的实验测试方法及传感器在拖拉机上的安装方法,采用labview软件平台设计测试软件,实验测试分别在水泥硬路面与泥土软路面上进行,将所测得的数据导入到Matlab软件中绘制出不同工况下的特性曲线并对其进行了分析。结果表明:全液压转向系统的方向盘转角与油缸活塞位移有着对应的函数关系,而方向盘转矩的大小不随着轮胎转向阻力矩大小的变化而变化。这些结论对今后转向系统的研究具有非常重要的指导意义与参考价值。

关键词：拖拉机全液压转向转向特性实验测试

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

深圳服务业的空间分布及自相关格局分析

引用

深圳大学学报（理工版） 2014年第6期31卷 638-646页

作者：章文程涛梅志雄王佳璆中山大学地理科学与规划学院广州510275 广东省城市化与地理环境空间模拟重点实验室广州510275 伦敦大学学院工程学院华南师范大学地理科学学院广州510631 伦敦大学学院高级空间分析中心

在建立深圳服务业地理数据库基础上,采用空间分析法分析深圳服务业的分布格局及空间自相关性.研究表明,点密度渲染和加权平均中心刻画出了地理要素总量分布情况,深圳服务业企业分布密度基本体现从市中心向外递减的规律,各服务业加权中... 详细信息

在建立深圳服务业地理数据库基础上,采用空间分析法分析深圳服务业的分布格局及空间自相关性.研究表明,点密度渲染和加权平均中心刻画出了地理要素总量分布情况,深圳服务业企业分布密度基本体现从市中心向外递减的规律,各服务业加权中心均西向偏离地理中心.通过Moran's I检验,显示深圳服务业具有不同的全局空间自相关性,高增加值比重(≥3%)服务业局部自相关集聚区呈多样化格局,区域分工已经形成,这是区位条件、经济联系和政府规划等因素共同作用的结果.研究指出,因为城市区位差异性和产业异质性的存在,不同区域有必要坚持定制化的服务业空间发展策略.

关键词：经济地理学空间分析法服务业发展战略空间自相关深圳第三产业区域经济

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：