检索结果-南通市图书馆

Quantification of the concrete freeze–thaw environment across the qinghai–Tibet Plateau based on machine learning algorithms

引用

Journal of Mountain Science 2024年第1期21卷 322-334页

作者： qin yanhui MA Haoyuan ZHANG Lele YIN Jinshuai ZHENG Xionghui LI Shuo Department of Civil Engineering Qingdao University of TechnologyQingdao 266520China Department of Geography Qinghai Normal UniversityXining 810008China

The reasonable quantification of the concrete freezing environment on the qinghai–Tibet Plateau(QTP) is the primary issue in frost resistant concrete design, which is one of the challenges that the QTP engineering managers should take into account. In this paper, we propose a more realistic method to calculate the number of concrete freeze–thaw cycles(NFTCs) on the QTP. The calculated results show that the NFTCs increase as the altitude of the meteorological station increases with the average NFTCs being 208.7. Four machine learning methods, i.e., the random forest(RF) model, generalized boosting method(GBM), generalized linear model(GLM), and generalized additive model(GAM), are used to fit the NFTCs. The root mean square error(RMSE) values of the RF, GBM, GLM, and GAM are 32.3, 4.3, 247.9, and 161.3, respectively. The R^(2) values of the RF, GBM, GLM, and GAM are 0.93, 0.99, 0.48, and 0.66, respectively. The GBM method performs the best compared to the other three methods, which was shown by the results of RMSE and R^(2) values. The quantitative results from the GBM method indicate that the lowest, medium, and highest NFTC values are distributed in the northern, central, and southern parts of the QTP, respectively. The annual NFTCs in the QTP region are mainly concentrated at 160 and above, and the average NFTCs is 200 across the QTP. Our results can provide scientific guidance and a theoretical basis for the freezing resistance design of concrete in various projects on the QTP.

关键词： Freeze–thaw cycles Quantification Machine learning algorithms qinghai–Tibet Plateau Concrete

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

Nano-effect enhanced cooperative luminescence of Yb^(3+) clusters in bulk materials

引用

Journal of Rare Earths 2024年第3期42卷 473-478,I0002页

作者： Daguang Li Jiahao Cui yanhui Dong Hao Cui Dan Zhao Weiping qin State Key Laboratory on Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun130012China

In order to improve the multi-ion cooperative transition, we proposed and exploited a novel nanoscale effect, namely the nanoshell effect in bulk materials. Based on the effect, an optimal material structure was designed by coating the surfaces of Ca F_(2):Yb^(3+)micron size particles with ZrO_(2). An about 2 times higher intensity of cooperative luminescence is observed upon laser excitation at 980 nm. Dynamical analysis exhibits that the novel effect plays a key role in improving the performance of cooperative transitions. Our results also suggest that the nanoshell effect in bulk materials is likely to be significant in some special cases, which have not been reported yet in the literature.

关键词： Yb^(3+)cluster ZrO_(2) Nanoshell Enhancement Cooperative luminescence Rare earths

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

Multi-Scale Design and Optimization of Composite Material Structure for Heavy-Duty Truck Protection Device

引用

Computer Modeling in Engineering & Sciences 2024年第5期139卷 1961-1980页

作者： yanhui Zhang Lianhua Ma Hailiang Su Jirong qin Zhining Chen Kaibiao Deng School of Mechanical and Automotive Engineering Guangxi University of Science and TechnologyLiuzhou545006China Commercial Vehicle Technology Center Dongfeng Liuzhou Automobile Co.Ltd.Liuzhou545005China School of Mechanical and Automotive Engineering South China University of TechnologyGuangzhou510641China

In this paper,to present a lightweight-developed front underrun protection device(FUPD)for heavy-duty trucks,plain weave carbon fiber reinforced plastic(CFRP)is used instead of the original high-strength steel.First,the mechanical and structural properties of plain carbon fiber composite anti-collision beams are comparatively analyzed from a multi-scale perspective.For studying the design capability of carbon fiber composite materials,we investigate the effects of TC-33 carbon fiber diameter(D),fiber yarn width(W)and height(H),and fiber yarn density(N)on the front underrun protective beam of carbon fiber compositematerials.Based on the investigation,a material-structure matching strategy suitable for the front underrun protective beam of heavy-duty trucks is proposed.Next,the composite material structure is optimized by applying size optimization and stack sequence optimization methods to obtain the higher performance carbon fiber composite front underrun protection beam of commercial vehicles.The results show that the fiber yarn height(H)has the greatest influence on the protective beam,and theH1matching scheme for the front underrun protective beamwith a carbon fiber composite structure exhibits superior performance.The proposed method achieves a weight reduction of 55.21% while still meeting regulatory requirements,which demonstrates its remarkable weight reduction effect.

关键词： Structural optimization front underrun protection device carbon fiber reinforced plastic multi-scale model lightweight design

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

AcWRKY28 mediated activation of AcCPK genes confers salt tolerance in pineapple(Ananas comosus)

引用

Horticultural Plant Journal 2024年第2期10卷 398-412页

作者： Qiao Zhou Samaranayaka Vidana Gamage Nirosha Priyadarshani Rongjuan qin Han Cheng Tiantian Luo Myat Hnin Wai Mohammad Aqa Mohammadi yanhui Liu Chang Liu Hanyang Cai Xiaomei Wang Yeqiang Liu Yuan qin Lulu Wang Guangxi Key Lab of Sugarcane Biology State Key Laboratory for Conservation and Utilization of Subtropical Agro-BioresourcesCollege of AgricultureGuangxi UniversityNanningGuangxi 530004China State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops College of Life ScienceCollege of Plant ProtectionCollege of AgricultureCollege of HorticultureFujian Provincial Key Laboratory of Haixia Applied Plant Systems BiologyCenter for Genomics and BiotechnologyFujian Agriculture and Forestry UniversityFuzhouFujian 350002China Pingtan Science and Technology Research Institute of Fujian Agriculture and Forestry University PingtanFujian 350400China National Education Commission BMICHColombo00700Sri Lanka Fishery Multiplication Management Station of Lijiang River Water Supply Hub Project GuilinGuangxi 541001China Horticulture Research Institute Guangxi Academy of Agricultural SciencesNanning Investigation Station of South Subtropical Fruit TreesMinistry of AgricultureNanningGuangxi 530007China

Unfavorable environmental cues severely affect crop productivity resulting in significant economic losses to farmers. In plants, multiple regulatory genes, such as the WRKY transcription factor (TF) family, modulate the expression of defense genes. However, the role of the pineapple WRKY genes is poorly understood. Here, we studied the pineapple WRKY gene, AcWRKY28, by generating AcWRKY28 over-expressing transgenic pineapple plants. Overexpression of AcWRKY28 enhanced the salt stress resistance in transgenic pineapple lines. Comparative transcriptome analysis of transgenic and wild-type pineapple plants showed that “plant-pathogen interaction” pathway genes, including 9calcium-dependent protein kinases (CPKs), were up-regulated in AcWRKY28 over-expressing plants. Furthermore, chromatin immunoprecipitation and yeast one-hybrid assays revealed AcCPK12, AcCPK3, AcCPK8, AcCPK1, and AcCPK15 as direct targets of AcWRKY28. Consistently, the study of AcCPK12 over-expressing Arabidopsis lines showed that AcCPK12 enhances salt, drought, and disease resistance. This study shows that AcWRKY28 plays a crucial role in promoting salt stress resistance by activating the expression of AcCPK genes.

关键词： Pineapple AcWRKY AcCPK Transcription factor Salt stress ChIP

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

Hydroxylated metal–organic-layer nanocages anchoring single atomic cobalt sites for robust photocatalytic CO_(2) reduction

引用

Nano Research 2024年第4期17卷 2410-2419页

作者： Weiyi Pan Zhihe Wei yanhui Su Yuebin Lian Zhangyi Zheng Huihong Yuan Yongze qin Xulan Xie Qianqian Bai Zhenyang Jiao Wei Hua Jinzhou Chen Wenjun Yang Zhao Deng Yang Peng Soochow Institute for Energy and Materials Innovations College of EnergySoochow UniversitySuzhou 215006China Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province Soochow UniversitySuzhou 215006China School of Photoelectric Engineering Changzhou institute of technologyChangzhou 213032China Jiangsu Key Laboratory for Advanced Negative Carbon Technologies Soochow UniversitySuzhou 215123China

Assembly of two-dimensional(2D)metal–organic layers(MOLs)based on the hard and soft acid–base theorem represents an exquisite strategy for the construction of photocatalytic platforms in virtue of the highly exposed active sites,much improved mass transport,and greatly elevated stability.Herein,nanocages composed of MOLs are produced for the first time through a cosolvent approach utilizing zirconium-based UiO-66-(OH)2 as the structural precursor.To endow the catalytic activity for CO_(2) conversion,single atomic Co^(2+)sites are appended to the Zr-oxo nodes of the MOL cages,demonstrating a remarkable CO yield of 7.74 mmol·g^(-1)·h^(-1) and operational stability of 97.1%product retention after five repeated cycles.Such an outstanding photocatalytic performance is mainly attributed to the unique nanocage morphology comprising enormous 2D nanosheets for augmented Co^(2+)exposure and the abundant surface hydroxyl groups for local CO_(2) enrichment.This work underlines the tailoring of both metal–organic framework(MOF)morphology and functionality to boost the turnover rate of photocatalytic CO_(2) reduction reaction(CO_(2)RR).

关键词： photocatalytic CO_(2) reduction metal–organic layer nanocage single-atom catalyst co-catalyst

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

A Population-Membrane-System-Inspired Evolutionary Algorithm for Distribution Network Reconfiguration

引用

Chinese Journal of Electronics 2014年第3期23卷 437-441页

作者： ZHANG Gexiang RONG Haina CHENG Jixiang qin yanhui School of Electrical Engineering Southwest Jiaotong University

This paper proposes a Populationmembrane-system-inspired evolutionary algorithm(PMSIEA), which is designed by using a population P system and a Quantum-inspired evolutionary algorithm(QIEA). PMSIEA uses the population P system with three cells to organize three variants of QIEAs, where communications between cells are performed at the level of genes,instead of the level of individuals reported in the existing membrane algorithms. This work provides a useful framework for synthesizing different algorithms at macro level and exchanging genic information at micro scale. Experimental results conduced on knapsack problems show that PMSIEA is superior to four representative QIEAs and our previous work with respect to the quality of solutions and the elapsed time. We also use PMSIEA to solve the optimal distribution system reconfiguration problem in power systems for minimizing the power loss.

关键词： Membrane computing Membrane-inspired evolutionary algorithm Population P system Distribution system reconfiguration

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

基于改进Faster R-CNN的隧道衬砌中离散实体目标自动检测研究

引用

铁道学报 2024年第2期46卷 171-180页

作者：崔广炎王艳辉徐杰丁冠军秦湘怡任秋阳北京交通大学先进轨道交通自主运行全国重点实验室北京100044 北京交通大学交通运输学院北京100044 北京交通大学北京市城市交通信息智能感知与服务工程技术研究中心北京100044 北京交通大学城市轨道交通运营安全管理技术及装备交通运输行业研发中心北京100044

隧道衬砌中离散实体目标的检测精度和时效性直接关乎隧道的运营安全,采用图像视觉技术进行图像自动解译可极大提升检测效率和结果的准确性,因此基于离散实体目标的雷达图像数据构建自定义雷达数据集合,并提出一套改进的Faster R-CNN算... 详细信息

隧道衬砌中离散实体目标的检测精度和时效性直接关乎隧道的运营安全,采用图像视觉技术进行图像自动解译可极大提升检测效率和结果的准确性,因此基于离散实体目标的雷达图像数据构建自定义雷达数据集合,并提出一套改进的Faster R-CNN算法对隧道衬砌中的离散实体目标进行自动检测。该算法首先对现有Faster R-CNN网络的特征提取模块进行改进,提出一套全新的轻量化特征提取网络ResNet_FMBConv对雷达图像特征进行深度挖掘;基于ResNet_FMBConv网络改进现有特征金字塔(FPN)结构,实现对多尺寸下目标的精准辨识。其次,基于实测和仿真的雷达图像数据构建离散实体目标的自定义雷达数据集合,通过几何变换方法对雷达图像进行数据增强后用于算法验证。结果表明,改进算法在IOU=0.50∶0.95情况下的检测精确率、召回率、F 1分数和FPS分别为45.1%、54.0%、49.1%和21.65 fps。在保证召回率基本持平的情况下,同比YOLOv3_spp、SSD、Retinanet和Faster R-CNN等目标检测算法的精确率和F 1分数分别提升2%~9%和1%~6%。同时,试验结果表明改进后的特征提取网络ResNet_FMBConv也优于现有Resnet-50、VGG16、Efficientnet_b0和Mobilenetv3等目标分类网络。

关键词：离散实体目标检测 Faster R-CNN ResNet_FMBConv模块 GPR 特征金字塔

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

儿童青少年新型冠状病毒感染流行病学研究进展

引用

中国学校卫生 2024年第1期45卷 142-147页

作者：秦阳董彦会谢俊卿苏彬彬宋逸马军北京大学公共卫生学院/北京大学儿童青少年卫生研究所北京100191 Centre for Statistics in Medicine NDORMSUniversity of Oxford 北京协和医学院群医学及公共卫生学院

新型冠状病毒感染(COVID-19,以下简称“新冠”)大流行带来了一系列复杂的挑战,COVID-19在儿童青少年身上的病情通常不及成年人和老年人严重;但在轻度或无症状的新冠之后,一些儿童青少年也可能出现一系列严重并发症和不良健康影响。文章... 详细信息

新型冠状病毒感染(COVID-19,以下简称“新冠”)大流行带来了一系列复杂的挑战,COVID-19在儿童青少年身上的病情通常不及成年人和老年人严重;但在轻度或无症状的新冠之后,一些儿童青少年也可能出现一系列严重并发症和不良健康影响。文章重点梳理儿童青少年新冠感染流行特征、健康影响、风险因素、防控措施和疫苗接种现状等,以期为后续儿童青少年新冠疫情防控提供参考。

关键词：冠状病毒属感染流行病学研究儿童青少年

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

1例复合杂合突变导致遗传性凝血因子Ⅺ缺陷症的分子致病机制

引用

中华血液学杂志 2024年第3期45卷 294-298页

作者：陈元秦朗译林双女杨丽红张柯叶龙颖金艳慧王明山温州医科大学附属第一医院医学检验中心浙江省检验诊断及转化研究重点实验室温州325015

1例34岁女性患者因“乳房结节”拟行手术切除,术前检查发现活化部分凝血活酶时间(APTT)66.2 s、凝血因子Ⅺ活性(FⅪ∶C)2%、FⅪ抗原(FⅪ∶Ag)40.3%,患者及家系成员均无异常出血表现。诊断为遗传性凝血因子Ⅺ缺陷症。基因检测发现其F11... 详细信息

1例34岁女性患者因“乳房结节”拟行手术切除,术前检查发现活化部分凝血活酶时间(APTT)66.2 s、凝血因子Ⅺ活性(FⅪ∶C)2%、FⅪ抗原(FⅪ∶Ag)40.3%,患者及家系成员均无异常出血表现。诊断为遗传性凝血因子Ⅺ缺陷症。基因检测发现其F11基因第10外显子c.1107C>A(p.Tyr351stop)杂合无义突变、第13外显子c.1562A>G(p.Tyr503Cys)杂合错义突变,其父亲和儿子为p.Tyr351stop突变的杂合携带者,而母亲和女儿为p.Tyr503Cys突变的杂合携带者。体外表达结果显示,p.Tyr351stop突变导致F11基因转录水平显著降低,而p.Tyr503Cys突变对F11基因转录水平以及蛋白表达水平无影响,但该突变导致细胞培养上清液中FⅪ∶C水平显著降低。

关键词：遗传性凝血因子Ⅺ缺陷症异常出血家系成员无义突变携带者凝血因子Ⅺ 基因检测分子致病机制

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

卫星柔性热控薄膜材料充放电效应试验

引用

国防科技大学学报 2024年第1期46卷 87-92页

作者：陈益峰王金晓冯娜秦晓刚杨生胜季启政韩炎晖柳青许昌学院表面微纳米材料研究所河南许昌461000 北京东方计量测试研究所北京100086 兰州空间技术物理研究所真空技术与物理重点实验室甘肃兰州730000

针对柔性热控薄膜材料导电/绝缘多层复合、微纳尺寸厚度的结构特点,采用10~70 KeV电子辐照的方法开展了kapton基二次表面镜薄膜材料充放电特性的测试试验,获得了表面充电电位、静电放电频次等关键参数,并采用蒙特卡罗方法研究了辐照电... 详细信息

针对柔性热控薄膜材料导电/绝缘多层复合、微纳尺寸厚度的结构特点,采用10~70 KeV电子辐照的方法开展了kapton基二次表面镜薄膜材料充放电特性的测试试验,获得了表面充电电位、静电放电频次等关键参数,并采用蒙特卡罗方法研究了辐照电子在多层薄膜材料内的输运规律。研究结果表明由于kapton基二次表面镜薄膜结构的特殊性,当辐照电子能量为10 KeV时未发生静电放电现象,随着电子能量不断增加,薄膜材料的表面充电电位幅值与静电放电频次呈先上升后下降的变化规律,且在电子能量为25 KeV时空间充放电效应最为显著。

关键词： kapton基二次表面镜空间充放电效应静电放电频次表面充电电位

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：