检索结果-南通市图书馆

Water storage changes in the North China Plain from 2004 to 2019

Science China(Technological Sciences) 2023年第7期66卷 2036-2046页

作者： CHEN MinLan XU YuYue PAN Hang wang luhan School of Geography and Ocean Science Nanjing UniversityNanjing 210023China Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology Nanjing UniversityNanjing 210023China Frontiers Science Center for Critical Earth Material Cycling Nanjing UniversityNanjing 210023China National Earth System Science Data Center National Science and Technology Infrastructure of ChinaBeijing 100101China

In the past few decades,the irrational use of water resources has resulted in many issues such as land subsidence in the North China Plain(NCP),hindering its socio-economic development.An accurate understanding of water resource changes is important for the allocation of water resources in the NCP.In this study,we employed Gravity Recovery and Climate Experiment(GRACE) satellite data to monitor the total water storage(TWS) change in the NCP during 2004–2019.Evapotranspiration,precipitation,and runoff during 2004–2019 were sequentially examined,using the water balance formula(WBF),to retrieve TWS change.Furthermore,the soil moisture,snow water equivalent,and canopy water storage from the Global Land Data Assimilation System were used to calculate the natural component of the TWS variations.A comparison of these results revealed the drivers of the changes in water resources.The results showed that:(1) overall TWS retrieved by GRACE decreased substantially as a consequence of human activity,while TWS obtained by WBF fluctuated periodically around zero under the impact of three natural drivers;(2) TWS in the NCP fell at a remarkable rate of-12.39 mm/y from 2004 to 2019,and the natural part of TWS experienced two significant declines,during 2004–2010 and 2013–2016;(3) variations in runoff,precipitation,and evapotranspiration from 2004 to 2019 were not significant,but human activities contributed more to the decreasing TWS than natural factors.This study provides a reference for water resource management and groundwater exploitation across the NCP under climate change.

关键词： North China Plain water storage GRACE human activities climatic factor

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

Numerical Taxonomy and Bayes Discriminant Analysis on 42 Fossil Species in Dicksoniaceae from China

引用

Acta Geologica Sinica(English Edition) 2019年第1期93卷 183-198页

作者： XIN Cunlin wang Jingjing wang luhan ZHANG Yamei College of Geography and Environmental Science Northwest Normal University

As the basal group of Polypodiales, the specific taxonomy of Dicksoniaceae is still being debated. As aquantitative analysis method, numerical taxonomy has been applied to the taxonomic study of many plant families andgenera in recent years due to its simplicity and high accuracy. However, the numerical analysis of the Dicksoniaceae fossilshas not been reported at present. In the present study, the pinnule morphological data of 42 Mesozoic fossil species of theDicksoniaceae were analyzed using cluster analysis, principal component analysis and correlation analysis. The resultsrevealed that 42 taxonomic units could be divided into six representative groups, which are consistent with the traditionaltaxonomy. After screening, an identification key on 28 fossil species of four genera with a definite taxonomic position wasestablished. According to the quantitative analysis, a Bayes discriminant model was established for the selected species.Lastly, the model was tested using the morphological data of the fossil pinnules in Dicksoniaceae from the YaojieFormation, suggesting that the discriminant model is accurate to a certain extent. As a result, the numerical taxonomy canbe applied to the classification of the Dicksoniaceae fossils.

关键词： Dicksoniaceae fossil plants numerical taxonomy Bayes discriminant analysis China

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

Cuticles and Spores in Situ of Coniopteris hymenophylloides from the Middle Jurassic in Gansu, Northwestern China

引用

Acta Geologica Sinica(English Edition) 2018年第3期92卷 904-914页

作者： XIN Cunlin wang luhan DU Baoxia ZHANG Yamei wang Jingjing College of Geography and Environmental Science Northwest Normal University College of Earth and Environmental Sciences Lanzhou University

Coniopteris was a ubiquitous plant of the Jurassic and Cretaceous periods and played an important role in the flora of the time. However, its anatomical structure is relatively poorly known. The specimens of Coniopteris hymenophylloides(Brongniart) Seward described here were collected from the Yaojie Formation in Gansu Province, northwestern China. The sterile fronds are characterized as being at least bipinnate with alternate arranged linear pinnae covered by thin cuticles. Fertile fronds are linear-lanceolate, with single sorus at the margin of each fertile pinnule. In situ spores are typically trilete, triangle to subcircular in polar view, cap-shaped in equatorial view, and 37 μm in average diameter. The trilete marking is straight and narrow, generally extends to 4/5 of the spore radius. The spore surface is smooth, and parts of the exine are granulated. The epidermal cells of cuticles are irregular in shape, approximately 40-60μm long and 10-20 μm wide. The elliptical stomatal complexes are paracytic,approximately 30 μm long and 19 μm wide,and irregularly distributed. On the basis of its epidermal structures and comparisons with extant ferns, we consider that Coniopteris displays combined features of the related extant genera.

关键词： Coniopteris hymenophylloides spore in situ cuticle Middle Jurassic Yaojie Formation Gansu China

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

Joint system consumption minimization and workload allocation in edge-core network

引用

The Journal of China Universities of Posts and Telecommunications 2018年第3期25卷 45-54页

作者： wang Shaochun Lu Zhaoming Wen Xiangming wang luhan Ma Lu Beijing Laboratory of Advanced Information Networks Beijing University of Posts and Telecommunications Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications

The explosive increase of smart devices and mobile traffic results intolerable network latency and degraded service to the end-users. in heavy burden on backhaul and core network, As a complement to core network, edge network contributes to relieving network burden and improving user experience. To investigate the problem of optimizing the total consumption in an edge-core network, the system consumption minimization problem is fromulated, considering the energy consumption and delay. Given that the formulated problem is a mixed nonlinear integer programming （MNIP） , a low-complexity workload allocation algorithm is proposed based on interior-point method. The proposed algorithm has an extremely short running time in practice. Finally, simulation results show that edge network can significantly complement core network with much reduced backhaul energy consumption and delay.

关键词： edge network core network system consumption optimization workload allocation

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

Service-oriented network performance evaluation framework based on LA-FAHP

引用

The Journal of China Universities of Posts and Telecommunications 2015年第3期22卷 74-83页

作者： Zhao Xing Lu Zhaoming wang luhan Wen Xiangming Lei Tao School of Information and Communication Engineering Beijing University of Posts and Telecommunications

Since the different characteristics of various network services determine that their requirements for network are also disparate, the performance of one network varies according to the services running on it. However, most of previous network performance evaluation （NPE） researches conduct evaluations based on the network parameters, but without considering from the perspective of specific service running on the network. In view of this issue, a novel service-oriented NPE framework is proposed. First, the characteristics discrepancy among different types of services are investigated. Next, in order to conduct comprehensive evaluation of multiple services, an enhanced low-complexity adaptive （LA）-fuzzy analytical hierarchy process （FAHP） is introduced; meanwhile by applying the experts-construct-directly （ECD） algorithm proposed later, the consistency check required in previous studies can be omitted, thereby significantly reducing the computation complexity and assessment workload for experts. Then, in accordance with the features of each service, corrections are made to their respective membership functions, thus making the proposed LA-FAHP adaptive to various service evaluation scenarios. The subsequent comparison with other NPE methods well proves the effectiveness and high sensitivity of proposed framework, and the analysis verifies the low computation complexity of the proposed algorithms as well.

关键词： network performance evaluation low-complexity adaptive- fuzzy analytical hierarchy process （LA- FAHP） service-oriented

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

Best-effort service QoE assessment using visual information based Weber-Fechner law

引用

The Journal of China Universities of Posts and Telecommunications 2016年第2期23卷 38-45页

作者： Guan Wanqing wang luhan Lu Zhaoming Wen Xiangming Chen Xin Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications

Quality of experience（QoE） has been one of the most important factors for service providers and operators to develop and deploy services. Previous works have shown that Weber-Fechner law（WFL） can be used to promote the accuracy of best-effort（BE） services＇ QoE assessment. In this paper, based on WFL, we take a deep insight into the visual information of BE services and its role in WFL, especially in web browsing services, and propose an enhanced QoE assessment model for BE services by taking the visual information into account. Both images and texts visual information are extracted and combined to get the visual information for web pages. Finally, a subjective experiment is performed to validate performance of proposed QoE assessment model, which shows that it performs better than traditional WFL based model.

关键词： QoE assessment Weber-Fechner law best-effort service visual information

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

我国老年人医疗服务政策文本量化分析

引用

中国卫生经济 2024年第4期43卷 26-32页

作者：吴振东王璐涵陈功武汉理工大学中国残疾人事业发展研究中心武汉420071 武汉理工大学法学与人文社会学院武汉420071 北京大学人口研究所北京100871

目的:研究系统梳理我国老年人医疗服务相关政策,分析政策的特征与现状,为推动我国老年人医疗服务政策体系的发展提出建议。方法:通过北大法宝,检索47份老年人医疗服务政策,构建“政策工具—政策过程—政策作用力”三维分析框架,并对其... 详细信息

目的:研究系统梳理我国老年人医疗服务相关政策,分析政策的特征与现状,为推动我国老年人医疗服务政策体系的发展提出建议。方法:通过北大法宝,检索47份老年人医疗服务政策,构建“政策工具—政策过程—政策作用力”三维分析框架,并对其进行量化分析。结果:发现我国老年人医疗服务政策存在政策工具结构性失衡、政策过程中监督与评估不足、政策制定主体单一且效力有限3个问题。结论:建议促进我国老年人医疗服务政策工具的均衡性发展、完善政策监督和政策评估、推进老年人医疗服务条例立法进程。

关键词：文本分析老年人医疗服务政策政策工具政策过程政策作用力

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

多聚焦显微图像融合算法

引用

激光与光电子学进展 2024年第6期61卷 322-330页

作者：付宏语巩岩汪路涵张艳微郎松张志郑汉青中国科学技术大学生物医学工程学院(苏州)生命科学与医学部江苏苏州215163 中国科学院苏州生物医学工程技术研究所医用光学技术研究室江苏苏州215163

在显微成像过程中,受系统景深限制,沿光轴方向不同层面之间聚焦位置存在显著差异,同时不同层面的显微图像存在部分聚焦区域重叠,现有多聚焦融合算法往往无法并行提取和融合多幅显微图像中最清晰的聚焦部分。提出一种多聚焦显微图像融合... 详细信息

在显微成像过程中,受系统景深限制,沿光轴方向不同层面之间聚焦位置存在显著差异,同时不同层面的显微图像存在部分聚焦区域重叠,现有多聚焦融合算法往往无法并行提取和融合多幅显微图像中最清晰的聚焦部分。提出一种多聚焦显微图像融合算法,首先构造了一种类高斯四邻域梯度算子并结合快速引导滤波,实现高频聚焦信息的提取;同时针对大视场显微图像序列中存在聚焦信息重叠、像素数量大的情况,引入了一种小区域聚焦度量方法,提高了对聚焦清晰区域高频信息提取的能力,实现了多图最佳聚焦点的融合。拍摄3组包括4 mm和2 mm对角线视场的多聚焦显微图像序列进行测试,相较5种常用多聚焦图像融合算法,所提算法的峰值信噪比平均提高了2.4772,结构相似性指数达0.9400以上,对聚焦清晰区域有更好的融合效果,融合图像细节丰富且清晰度高,能够满足大视场多聚焦显微图像融合的准确性要求。

关键词：图像处理多聚焦显微图像引导滤波聚焦信息检测多图融合

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

ML-SLD:A message-level stateless design for cloud-native 5G core network

引用

Digital Communications and Networks 2023年第3期9卷 743-756页

作者： Keliang Du luhan wang Xiangming Wen Yu Liu Haiwen Niu Shaoxin Huang Beijing Laboratory of Advanced Information Networks China Beijing Key Lab of Network System Architecture and Convergence China School of Information and Communication Engineering Beijing Univ.of Posts&TelecomBeijing100876China

The Internet of Things(IoTs)has become an essential component of the 5th Generation(5G)network and beyond,accelerating the transition to digital society.The increasing signaling traffic generated by billions of IoT devices has placed significant strain on the 5G Core network(5GC)control plane.To address this issue,the 3rd Gener-ation Partnership Project(3GPP)first proposed a Service-Based Architecture(SBA),intending to create a flexible,scalable,and agile cloud-native 5GC.However,considering the coupling of protocol states and functions,there are still many challenges to fully utilize the benefits of the cloud computing and orchestrate the 5GC in a cloud-native manner.We propose a Message-Level StateLess Design(ML-SLD)to provide a cloud-native 5GC from an architectural standpoint in this paper.Firstly,we propose an innovative mechanism for servitization of the N2 interface to maintain the connection between Radio Access Network(RAN)and the 5GC,avoiding interruptions and dropouts of large-scale user data.Furthermore,we propose an On-demand Message Forwarding(OMF)al-gorithm to reduce the impact of cloud fluctuations on the performance of cloud-native 5GC.Finally,we create a prototype that is based on the OpenAirInterface(OAI)5G core network projects,with all Network Functions(NFs)packaged in dockers and deployed in a kubernetes-based cloud environment.Several experiments have been built with UERANSIM and Chaosblade simulation tools.The findings demonstrate the viability and efficiency of our proposed methods.

关键词： Cloud-native 5G core network service Based architecture Stateless OpenAirInterface

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

Ce:GdYAG phosphor-in-glass:An innovative yellow-emitting color converter for solid-state laser lighting

引用

Journal of Materials Science & Technology 2023年第3期134卷 42-49页

作者： luhan wang Jiangdan Zhang Li Xu Shuyang Bao Yu wang Jiawei Liu Xiaojuan Liang Weidong Xiang College of Chemistry and Materials Engineering Wenzhou UniversityWenzhou 325035China College of Life and Environmental Science Wenzhou UniversityWenzhou 325035China

Stable,efficient and high color rendering index all-inorganic color converters are urgently demanded for white laser diodes.Phosphor-in-glass(PiG),possessing the advantages of phosphors excellent quantum efficiency as well as favorable chemical and thermal stability of glass,has attracted widespread attention.There have been only very few reports of Y_(1.31)Ce_(0.09)Gd_(1.6)Al_(5)O_(12)(Ce:GdYAG)PiG for solid-state laser light-ing.Herein,a series of Ce:GdYAG PiG samples are fabricated by a simple solid-state sintering method.Impressively,the supreme internal quantum efficiency of as-prepared PiG is 91%,which is very close to original phosphors(95%).Furthermore,PiG exhibits a high thermal conductivity(1.844 W m^(−1)K^(−1))and a maximum transparency(62%).Remarkably,by changing the concentration of phosphors and the thickness of PiG samples,a luminous efficacy of 163.5 lm/W,high color rendering index of 74.8 and low correlated color temperature of 4806.8 K are achieved under blue laser irradiation.These results indicate that the Ce:GdYAG PiG samples have shown tremendous application foreground as all-inorganic color converter for solid-state laser lighting.

关键词： Ce:GdYAG Phosphor-in-glass Solid-state laser lighting Optical performance

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

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：