检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

成昆线红层地区泥石流沟侵蚀程度量化分析

中国铁道科学 2006年第2期27卷 1-5页

作者：秦军王一川西南交通大学遥感中心四川成都610031

以成昆铁路红层地区的3个小流域为研究区,计算3个年份的地面割裂度及其年平均变化率,分析用地面割裂度表征泥石流沟侵蚀程度的不足及其原因。基于泥石流沟发育的物理模型,以原来的地面割裂度定义为基础,引入表述沟谷分布零散程度的异型... 详细信息

以成昆铁路红层地区的3个小流域为研究区,计算3个年份的地面割裂度及其年平均变化率,分析用地面割裂度表征泥石流沟侵蚀程度的不足及其原因。基于泥石流沟发育的物理模型,以原来的地面割裂度定义为基础,引入表述沟谷分布零散程度的异型度因子,导出新侵蚀系数公式。以3个小流域固体物质的年平均流失量作为侵蚀程度强弱的标准,采用非参数统计推断方法,将侵蚀系数、地面割裂度的年变化值和固体物质的年平均流失量作秩统计和次序统计。对秩统计参数和次序统计参数比较结果表明:在表征泥石流沟侵蚀程度方面,侵蚀系数优于地面割裂度。

关键词：泥石流侵蚀程度地面割裂度水土流失数字地形模型量化分析

在线全文

学校读者我要写书评

暂无评论

基于期刊耦合和作者耦合的学科内部结构研究

情报科学 2016年第12期34卷 108-114页

作者：赵文涟张艺蔓曲阜师范大学图书馆山东日照276826 东营职业学院图书与信息技术中心山东东营257091

以耦合分析方法为基础,证明耦合分析对于探索学科内部结构的有效性,以期为以后的研究提供借鉴和参考,促进耦合分析多样化发展和在知识分析中的推广应用。综合运用因子分析、聚类分析、多维尺度分析、社会网络分析等方法,利用期刊耦合分... 详细信息

以耦合分析方法为基础,证明耦合分析对于探索学科内部结构的有效性,以期为以后的研究提供借鉴和参考,促进耦合分析多样化发展和在知识分析中的推广应用。综合运用因子分析、聚类分析、多维尺度分析、社会网络分析等方法,利用期刊耦合分析与作者耦合分析方法对图书情报学的学科内部结构进行分析。在期刊耦合分析中,开创性地选取了新的耦合对象——被引期刊,建立期刊-引文期刊耦合强度指标,将图书情报学18种期刊划分为四类;在作者耦合分析中,加入了内容分析法——共词分析,通过共同的词语将作者联系到一起,发现其研究的同一主题,建立作者关键词耦合强度指标,运用社会网络分析法,将核心作者划分为六类。研究结果与图书情报学科的研究主题及学科特点基本一致,且划分更为细致,分别说明了期刊-引文期刊耦合分析和作者耦合分析的有效性,也证明了耦合分析对于分析学科内部结构的有效性。

关键词：期刊耦合分析作者耦合分析学科内部结构

在线全文

学校读者我要写书评

暂无评论

基于募集机制的连续蚁群系统及其应用

浙江大学学报（工学版） 2006年第5期40卷 748-752页

作者：贺益君俞欢军陈德钊浙江大学化学工程与生物工程学系浙江杭州310027

针对经典蚁群算法只适用于离散优化问题的不足,从蚂蚁觅食的生物学行为出发,以寻觅最优食物源为目标,运用蚁群的海量募集和成群募集两种机制,并结合蚂蚁的厌食现象,均衡地搜索,由此构建了适用于连续问题的蚁群优化系统(MG-CACO).经典函... 详细信息

针对经典蚁群算法只适用于离散优化问题的不足,从蚂蚁觅食的生物学行为出发,以寻觅最优食物源为目标,运用蚁群的海量募集和成群募集两种机制,并结合蚂蚁的厌食现象,均衡地搜索,由此构建了适用于连续问题的蚁群优化系统(MG-CACO).经典函数的测试表明,MG-CACO的全局寻优效率高,稳健性良好,尤其对高维问题的适应性强.将MG-CACO用于二甲苯异构化装置的操作条件优化,效果令人满意,其全局寻优性能和稳定性均优于其他方法.

关键词：蚁群优化系统海量募集成群募集厌食现象二甲苯异构化

A review on spatial self-phase modulation of two-dimensional materials

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2019年第9期26卷 2295-2306页

作者： ZHANG Xue-jun YUAN Zhen-hua YANG Rui-xin HE yi-lin QIN ying-lin XIAO Si HE jun Hunan Key Laboratory of Super Microstructure and Ultrafast Process School of Physics and ElectronicsCentral South UniversityChangsha 410083China

Self-diffraction appears when the strong laser goes through two-dimensional material suspension,and this spatial self-phase modulation(SPPM)phenomenon can be used to measure nonlinear optical parameters and achieve optical *** present,the mechanism of SPPM is still *** debate mainly focuses on whether the phenomenon is caused by the nonlinear refractive index of the two-dimensional material or the thermal effect of the *** lack of theory limits the dimension of the phase modulation to the radius of the diffraction ring and the vertical ***,it is urgent to establish a unified and universal SSPM theoretical system of two-dimensional material.

关键词： nonlinear optics spatial self-phase modulation two-dimensional materials

The Influence of the Verticillium dahliae Kleb Infection on the Anti-Enzyme Inside the Body of the Cotton with Different Root Injured Degree

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2007年第7期6卷 816-824页

作者： FAN Wei-wei WANG Li-an MA Chun-hong DONG Wen-qi LI Yun-chao LIU Zi-hui JIA yin-suo GENG jun-yi ZHANG Xiang-yun Shijiazhuang Center for Disease Control and Prevention Shijiazhuang 050011 P.R.China College of Life Science Hebei Normal University Shijiazhuang 050016 P.R.China Institute of Genetics and Physiology Hebei Academy of Agriculture and Forestry Sciences Shijiazhuang 050051 P.R. China Hebei Academy of Agriculture and Forestry Sciences Shijiazhuang 050051 P.R.China Institute of Cotton Hebei Academy of Agriculture and Forestry Sciences Shijiazhuang 050051 P.R.China

This study was to explore the influence of the Verticillium dahliae Kleb inflection on the anti-enzyme inside the body of the cotton with a different root injured degree. When the cotton seedling was long, with four leaves, it was flushed with water carefully, and then the following were obtained：（1） complete root seedling; （2） cut root seedling - by cutting off the lower part, 3-5 cm of the root, with a disinfected knife; （3） injured root seedling - by cutting off most of the side roots, but keeping the main root. Three kinds of cotton seedlings with different roots were immersed separately in different concentrations of the germ liquid （V. dahliae） of 20 mL each. Through 0- 48 h, the wilt degree of the seedling was recorded, and the related anti-enzyme of the variety was measured. After being immersed in the germ liquid, there was a significant difference in the wilt degree of the three kinds of injured root. When the germ liquid was in the ratio of 1：10, the complete root seedling was the lightest with no wilt; the injured root seedling was the second with a 2-degree wilt; but the cut root seedling was the most serious with a 3- degree wilt. At the same time, the changes in the peroxidase and malondialdehvde activities were determined. Peroxidase （POD） activities in the cut root seedling were 38.2 U mg^-1 min^-1, in the injured root seedling were 42.96 U mg^-1 min^-1, and in the complete root seedling were the highest at 49.2 U mg^-1 min^-1. The malondialdenvde （MDA） content in cut root seedling was 39.483 mmol g^-1, injured root seedling was 27.12 mmol g^-1, and the complete root seedling was only 3.845 mmol g^-1 The activity of the related anti-enzymes, such as POD was high or low, the quantity of the MDA was more or less, which they met the order of the harm of the seedlings. The change of SOD activities in cut root seedling was the most obvious as well. After injuring and inflecting the young roots, the exterior pathological reaction of the seedling and the

关键词： cotton Verticillium dahliae Kleb injury of root POD SOD MDA

Evaluation of 10 Different Pipelines for Bacterial Single-Nucleotide Variant Detection

在线全文

学校读者我要写书评

暂无评论

Infectious Microbes & Diseases 2023年第4期5卷 172-179页

作者： Zi-Hao Hu yingWang Long Yang Qing-yi Cao Ming Ling Xiao-Hua Meng Yao Chen Shu-jun Ni Zhi Chen Cheng-Zhi Liu Kun-Kai Su Zhejiang University–University of Edinburgh Institute(ZJU-UoE Institute) School of MedicineZhejiang UniversityHainingChina State Key Laboratory for Diagnosis and Treatment of Infectious Diseases Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseasesthe First Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhouChina Hangzhou Digital-Micro Biotech Co LtdHangzhouChina JinanMicroecological Biomedicine Shandong Laboratory JinanChina Jinhua Institute for Food and Drug Control JinhuaChina

Bacterial genome sequencing is a powerful technique for studying the genetic diversity and evolution ofmicrobial ***,the detection of genomic variants from sequencing data is challenging due to the presence of contamination,sequencing errors and multiple strains within the same *** bioinformatics tools have been developed to address these issues,but their performance and accuracy have not been systematically *** this study,we compared 10 variant detection pipelines using 18 simulated and 17 real datasets of high-throughput sequences froma bundle of representative *** assessed the sensitivity of each pipeline under different conditions of coverage,simulation and strain *** also demonstrated the application of these tools to identify consistentmutations in a 30-time repeated sequencing dataset of Staphylococcus *** found that HaplotypeCaller,but not Mutect2,from the GATK tool set showed the best performance in terms of accuracy and *** and Snippy performed not as well in several simulated and real sequencing *** results provided a comprehensive benchmark and guidance for choosing the optimal variant detection pipeline for high-throughput bacterial genome sequencing data.

关键词： bacterial single-nucleotide variant GATK Snippy CFSAN

Ferroelectric artificial synapse for neuromorphic computing and flexible applications

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

Fundamental Research 2023年第6期3卷 960-966页

作者： Qing-Xuan Li yi-Lun Liu Yuan-Yuan Cao Tian-Yu Wang Hao Zhu Li Ji Wen-jun Liu Qing-Qing Sun David Wei Zhang Lin Chen State Key Laboratory of ASIC and System School of MicroelectronicsFudan UniversityShanghai 200433China National Integrated Circuit Innovation Center No.825 Zhangheng RoadShanghai 201203China

Research of artificial synapses is increasing in popularity with the development of bioelectronics and the appearance of wearable *** the high-temperature treatment process of inorganic materials is not compatible with flexible substrates,organic ferroelectric materials that are easier to process have emerged as *** organic synaptic device based on P(VDF-TrFE)was prepared in this *** device showed reliable P/E endurance over 104 cycles and a data storage retention capability at 80℃ over 104 ***,it possessed excellent synaptic functions,including short-term/long-term synaptic plasticity and spike-timing-dependent *** addition,the ferroelectric performance of the device remained stable even under bending(7 mm bending radius)or after 500 bending *** work shows that low-temperature processed organic ferroelectric materials can provide new ideas for the future development of wearable electronics and flexible artificial synapses.

关键词： Organic artificial synapse Neuromorphic computing Synaptic devices Wearable electronics Ferroelectric

具有时变时滞的离散切换系统的鲁棒H_∞控制

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

东北大学学报（自然科学版） 2007年第4期28卷 469-472页

作者：宋政一聂宏赵军东北大学信息科学与工程学院辽宁沈阳110004

利用多Lyapunov函数方法,研究一类具有时变时滞的线性离散切换系统的鲁棒H∞控制问题.在每个子系统都不能实现鲁棒H∞控制的假设条件下,基于切换状态反馈控制策略,给出了系统实现鲁棒H∞控制的充分条件,且这一条件可以表示成与时滞界相... 详细信息

利用多Lyapunov函数方法,研究一类具有时变时滞的线性离散切换系统的鲁棒H∞控制问题.在每个子系统都不能实现鲁棒H∞控制的假设条件下,基于切换状态反馈控制策略,给出了系统实现鲁棒H∞控制的充分条件,且这一条件可以表示成与时滞界相关的线性矩阵不等式(LMI)的形式,还分别给出了切换律和鲁棒H∞切换控制器的设计方案,并讨论了时滞界与H∞性能的关系.最后的仿真例子表明了结论的有效性.

关键词：线性离散切换系统时变时滞鲁棒H∞控制多Lyapunov函数线性矩阵不等式(LMI)

在线全文

学校读者我要写书评

暂无评论

轴突导向信号的研究进展

军事医学科学院院刊 2006年第2期30卷 180-183页

作者：马振莲刘少君军事医学科学院基础医学研究所北京100850

在神经发育过程中,轴突沿特定的路径延伸,穿越很长的路线到达靶区并与之形成精确的神经连接。轴突在前进过程中受到多种因素的影响,其中最主要的是具有吸引或排斥作用的导向分子,这类分子既可以通过长程也可以通过短程方式指导轴突选择... 详细信息

在神经发育过程中,轴突沿特定的路径延伸,穿越很长的路线到达靶区并与之形成精确的神经连接。轴突在前进过程中受到多种因素的影响,其中最主要的是具有吸引或排斥作用的导向分子,这类分子既可以通过长程也可以通过短程方式指导轴突选择正确的前进路线,目前发现的轴突导向分子家族主要有netrins,slits,sem a-phorins和ephrins。此外,神经营养因子、细胞黏附分子、胞外基质分子等对轴突延伸也具有导向作用。这些分子与相应的受体结合,启动下游的一系列信号转导途径,调控生长锥的细胞骨架动力学,使轴突按特定的路径前进并最终到达靶标。

关键词：轴突受体信号转导生长锥