检索结果-南通市图书馆

Science China(Information Sciences) 2019年第2期62卷 224-229页

作者： Ding XU qun li Wireless Communication Key Lab of Jiangsu Province Nanjing University of Posts and Telecommunications Jiangsu Key Lab of Big Data Security and Intelligent Processing Nanjing University of Posts and Telecommunications

Dear editor,Wireless powered communication networks(WPCNs) are popular especially for wireless sensor networks where sensors can be wirelessly powered. For coordinating wireless power and information transfer, Ju and Zhang in their pioneer work [1] proposed a "harvest-then-transmit" protocol for WPCN, where the time for wireless power transfer (WPT) and wireless information transfer(WIT) is divided into two phases:the WPT phase and WIT phase. Meanwhile, cognitive radio (CR)

关键词： WIT Resource allocation in cognitive wireless powered communication networks with wirelessly powered secondary users and primary users

Progress of Studies on Multi-Color Long Afterglow Luminescence Materials

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2004年第Z1期22卷 295-301页

作者： li qun Teng Xiaoming General Research Institute for Nonferrous Metals Beijing 100088 Grirem Advanced Materials Co.Ltd.Beijing 100088 China Institute of Chemistry and Material Science Anhui Normal University Wuhu241000 China

Progress of studies on various multi-color long afterglow luminescence materials was *** luminescent mechanism of long afterglow behavior were *** research and development prospects about the materials were proposed.

关键词： long afterlow materials mechanism luminescence rare earths

基于DBO-GRNN神经网络的冰水堆积物渗透系数预测

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

人民长江 2025年第2期56卷 167-174页

作者：彭俊皓魏玉峰李常虎王群李征征成都理工大学地质灾害防治与地质环境保护国家重点实验室四川成都610059 中国电建集团西北勘测设计研究院有限公司陕西西安710065

冰水堆积物具有粒径范围宽、颗粒组成不均匀的特点,此类颗粒级配特征会较大程度上影响其渗透特性,从而影响水利水电工程的安全运行。以易贡藏布流域夏曲水电站冰水堆积物为研究对象,设计开展20组室内常水头渗透试验,建立了考虑级配面积... 详细信息

冰水堆积物具有粒径范围宽、颗粒组成不均匀的特点,此类颗粒级配特征会较大程度上影响其渗透特性,从而影响水利水电工程的安全运行。以易贡藏布流域夏曲水电站冰水堆积物为研究对象,设计开展20组室内常水头渗透试验,建立了考虑级配面积的渗透系数计算经验公式;在此基础上,以试验数据为样本建立蜣螂算法(DBO)优化的GRNN神经网络,以特征粒径d 10~d 100、级配面积S为输入变量,预测冰水堆积物的渗透系数;并开展4组现场单环渗透试验验证DBO-GRNN模型精度。结果显示:该模型的渗透系数预测值与试验值能较好地吻合,误差在5%以内,而经验公式预测值、传统BP神经网络预测值与试验值的误差最大分别为61.29%和37.50%,表明DBO-GRNN神经网络可以较为准确地获取冰水堆积物的渗透系数。

关键词：冰水堆积物渗透系数颗粒级配 DBO-GRNN神经网络渗透试验夏曲水电站

Dynamic mechanical characteristics of NdFeB in electromagnetic brake

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

Defence Technology（防务技术） 2023年第1期19卷 111-125页

作者： Lei li Guo-lai Yang li-qun Wang School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094JiangsuChina

With the continuous development of artillery,the disadvantages of hydraulic recoil brakes gradually *** the same time,the appearance of high-performance Nd Fe B permanent magnet makes it possible to apply electromagnetic braking technology to recoil *** this paper,prototype tests of a certain artillery were carried out to verify the feasibility of the electromagnetic brake(EMB)and obtain the electromagnetic braking *** to the brittleness of Nd Fe B,in order to eliminate the worry about the safety of EMB,SHPB experiments of Nd Fe B were carried ***,based on the assumption of uniform crack distribution,the law of crack propagation and damage accumulation was described theoretically,and the damage constitutive model suitable for brittle materials was proposed by combining the Zhu-Wang-Tang(ZWT)***,the numerical simulation model of the artillery prototype was established and through calculation,the dynamic mechanical characteristics of Nd Fe B in the prototype were *** calculation results show that the strength of Nd Fe B can meet the requirements of the use in the working *** the perspective of damage factor,the damage value of the permanent magnet on the far right is larger,and the damage value of the inner ring gradually decreases to the outer ring.

关键词： Electromagnetic brake Sintered NdFeB Damage constitutive Dynamic mechanical characteristics

石斛碱通过作用于SRC调控氧化应激干预糖尿病肾病的机制研究

在线全文

学校读者我要写书评

暂无评论

海南医科大学学报 2025年第1期31卷 41-50页

作者：李军薛铃芝马群张楠楠贵州中医药大学基础医学院贵州贵阳550025

目的:探讨石斛碱通过调控氧化应激干预糖尿病肾病(DKD)的作用机制。方法:利用OMIM等数据库检索DKD靶点,使用PharmMapper、SuperPred、ChemMapper和ChEMBL数据库获得石斛碱靶点,通过GeneCards、OMIM数据库检筛选氧化应激相关靶点,并取交... 详细信息

目的:探讨石斛碱通过调控氧化应激干预糖尿病肾病(DKD)的作用机制。方法:利用OMIM等数据库检索DKD靶点,使用PharmMapper、SuperPred、ChemMapper和ChEMBL数据库获得石斛碱靶点,通过GeneCards、OMIM数据库检筛选氧化应激相关靶点,并取交集靶点。交集靶点导入STRING数据库获取靶标相互联系以构建PPI,利用MCC拓扑算法分析获取关键靶点。关键作用靶点通过DAVID平台进行基因本体论(GO)分析、京都基因与基因组百科全书(KEGG)富集分析。通过SangerBox平台进行糖尿病肾病临床相关性分析、基因差异表达分析以及ROC分析。将筛选得到的关键靶点通过分子对接和分子动力学模拟进行验证。采用Western Blot实验进行实验验证。结果:获得DKD-石斛碱-氧化应激交集靶点102个,并筛选出15个关键基因;通过临床相关性分析筛选出11个有临床意义的关键基因;通过差异表达和ROC分析发现CASP3、CXCR4、ESR1、KDR、SRC差异表达明显,且SRC最具有诊断价值(AUC=0.86,P<0.05);分子对接及分子动力学模拟分析结果发现SRC与石斛碱结合能力最强,且配合物较稳定。Western Blot实验结果表明,与对照组相比SRC和P-SRC在DKD中表达上调(P<0.05),石斛碱可降低其的表达。结论:石斛碱可以通过作用于SRC调控氧化应激干预糖尿病肾病。

关键词：糖尿病肾病石斛碱氧化应激网络药理学分子对接

基于全转录组测序探讨褪黑素抑制神经胶质瘤细胞增殖的机制

在线全文

学校读者我要写书评

暂无评论

中国药理学通报 2025年第1期41卷 163-170页

作者：徐丽陈秀娇郑伟男毛馨琳林丽彬谢群金清东莆田学院基础医学院福建莆田351100 莆田学院基础医学院肿瘤转化医学福建省高校重点实验室福建莆田351100 莆田市第一医院神经外科福建莆田351100

目的全转录组测序检测神经胶质瘤细胞非编码RNA(ncRNA)表达谱并构建ceRNA网络,揭示ncRNA参与褪黑素抑制神经胶质瘤细胞增殖的分子机制。方法0、2、4、6、8 mmol·L^(-1)褪黑素干预神经胶质瘤细胞24、48、72 h,CCK-8检测褪黑素对细胞增... 详细信息

目的全转录组测序检测神经胶质瘤细胞非编码RNA(ncRNA)表达谱并构建ceRNA网络,揭示ncRNA参与褪黑素抑制神经胶质瘤细胞增殖的分子机制。方法0、2、4、6、8 mmol·L^(-1)褪黑素干预神经胶质瘤细胞24、48、72 h,CCK-8检测褪黑素对细胞增殖的抑制作用;0、4 mmol·L^(-1)褪黑素干预U251细胞24h后,全转录组测序检测差异表达miRNA(DEmiRNA)、lncRNA(DElncRNA)、mRNA(DEmRNA),对DEmRNA进行GO和KEGG富集分析;构建ceRNA网络,采用qRT-PCR验证ceRNA关键基因表达。结果褪黑素呈时间-剂量依赖性抑制神经胶质瘤细胞增殖;全转录组测序筛选出0 mmol·L^(-1)与4 mmol·L^(-1)褪黑素组DEmRNA 5049个、DElncRNA 635个、DEmiRNA 146个;DEmRNA主要富集在铁死亡、mTOR信号通路、FoxO信号通路、细胞周期等癌症相关信号通路;ceRNA网络包含4个lncRNA、3个miRNA和48个mRNA,qRT-PCR验证U251细胞hsa-miR-129-5p、hsa-miR-362-5p、liNC00707和SLC16A1-AS1表达与测序结果一致,U87细胞的基因表达与测序结果基本一致。结论褪黑素通过ncRNA差异表达,影响癌症相关信号通路,进而抑制神经胶质瘤细胞增殖;liNC00707、SLC16A1-AS1、hsa-miR-129-5p、hsa-miR-362-5p构成的ceRNA网络可能参与褪黑素抑制神经胶质瘤细胞增殖的分子机制。

关键词：褪黑素神经胶质瘤全转录组测序 ceRNA网络 hsa-miR-129-5p hsa-miR-362-5p

同方期刊数据库博看期刊

Experimental Study on Thermal Management of Cylindrical li-ion Battery with Flexible Microchannel Plates

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2020年第4期29卷 1001-1009页

作者： WEI liting JIA li AN Zhoujian dang Chao Institute of Thermal Engineering School of MechanicalElectronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China Beijing Key Laboratory of Flow and Heat Transfer of Phase Changing in Micro and Small Scale Beijing 100044China

A novel thermal management system of cylindrical li-ion battery with the liquid cooling in flexible microchannel plate was established in the study. The experiments were conducted with R141 b in flexible microchannel plates. The cooling system with the flexible aluminum microchannels can effectively transfer heat from battery to the cooling refrigerant R141 b based on flow boiling. A battery module with five cells along flow channel was chosen to study the effects of contact surface area and mass flux on the thermal performance and electrochemical characteristics in the experiments. Three types of structure with different contact areas were studied and their performances were compared with the experiments without cooling structures. The experiments were carried out at the same discharge rate with the inlet mass flow rates of 0–10 kg/h. For the inlet mass flow rate of 5.98 kg/h, the surface temperature and temperature uniformity of battery were the best, and the output voltage and capacity of batteries were higher than those under other mass flow rates. With given inlet mass flow rates, the five series cells exhibited different electrochemical performances, including output voltage and discharge capacity, due to the different refrigerant flow states in the microchannels. Finally, an optimal design was presented with thermal performances, macroscopic electrochemical characteristics, inlet mass flow rates and cooling performance taken into consideration.

关键词： thermal management li-ion battery flexible microchannels contact area

关中地区典型行业VOCs排放源成分谱及环境影响

在线全文

学校读者我要写书评

暂无评论

中国环境科学 2025年第2期45卷 619-628页

作者：董静李顺姬党小庆屈嘉鑫王赫吉硕西安建筑科技大学环境与市政工程学院陕西西安710055 西安市环境保护科学研究院陕西西安710061

持续推进关中地区VOCs精细化管控,以西安市和咸阳市为代表,选取包装印刷、电子产品制造、工业涂装、涂料及油墨制造、家具制造和橡胶制品6个行业进行样品采集,研究关中地区典型行业VOCs排放源成分谱、臭氧生成潜势(OFP)和二次气溶胶生... 详细信息

持续推进关中地区VOCs精细化管控,以西安市和咸阳市为代表,选取包装印刷、电子产品制造、工业涂装、涂料及油墨制造、家具制造和橡胶制品6个行业进行样品采集,研究关中地区典型行业VOCs排放源成分谱、臭氧生成潜势(OFP)和二次气溶胶生成潜势(SOAFP).结果表明:包装印刷和工业涂装行业主要排放VOCs为含氧挥发性有机物(OVOCs)(53%~73%)和烷烃(17%~34%);电子产品制造行业为OVOCs(68%)和烯烃(29%);涂料及油墨制造行业以OVOCs(61%)和芳香烃(22%)为主;家具制造行业以芳香烃(78%)和OVOCs(19%)为主;橡胶制品行业以烷烃(78%)为主.其中乙醇、丙酮、异丙醇、甲醛、乙酸乙酯、间/对-二甲苯为关中地区典型行业排放的主要特征物种.基于最大增量反应活性法(MIR)和气溶胶生成系数法(FAC),得出OVOCs、芳香烃和烯烃是OFP的主要来源,芳香烃是SOAFP的主要来源,主要排放来源为涂料及油墨制造、工业涂装和家具制造行业应重点管控.

关键词：关中地区典型行业挥发性有机物(VOCs) 源成分谱臭氧生成潜势(OFP) 二次气溶胶生成潜势(SOAFP)

A Double Varying-coefficient Modeling Approach for Analyzing Longitudinal Observations

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2019年第3期35卷 671-688页

作者： qun-fang XU Rui li School of Business Ningbo UniversityNingbo 315211China School of Statistics and Information Shanghai University of International Business and EconomicsShanghai 201620China Key Laboratory of Advanced Theory and Application in Statistics and Data Science East China Normal UniversityMinistry of EducationShanghai 200062China

The identification of within-subject dependence is important for constructing efficient estimation in longitudinal data *** this paper,we proposed a flexible way to study this dependence by using nonparametric regression ***,we considered the estimation of varying coefficient longitudinal data model with non-stationary varying coefficient autoregressive error process over observational time *** on spline approximation and local polynomial techniques,we proposed a two-stage nonparametric estimation for unknown functional coefficients and didn’t not drop any observations in a hybrid least square loss ***,we showed that the estimated coefficient functions are asymptotically normal and derived the asymptotic biases and variances *** Carlo studies and two real applications were conducted for illustrating the performance of our proposed methods.

关键词： autoregressive process double varying coefficient irregular time quantum locally linear

The Mixed-Mode Fatigue Crack Propagation Model of Piezoelectric Materials Under Electric Fatigue Loading by the J_(k)-Integral

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2024年第4期37卷 634-641页

作者： Xianghua Chen Chunguang Wang qun li The Institute of Xi’an Aerospace Solid Propulsion Technology Xi’an710025China State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an710049China

The electric fatigue load has a significant effect on the crack propagation behavior and failure life of piezoelectric materials and devices. In this paper, an electrical mixed-mode fatigue crack propagation model for piezoelectric materials is proposed based on the piezoelectric J_(k)-integral theory. The crack initiation, propagation, and life prediction criteria of piezoelectric materials under electric fatigue loading are given by this model, and the finite element simulation model is established to study the electrical mixed-mode crack propagation behavior of piezoelectric structures. Meanwhile, the electrical mixed-mode fatigue crack propagation model is applied to the fatigue crack propagation behavior of a piezoelectric typical defective structure, the crack–hole interference model. The mixed-mode crack propagation, fatigue life, and the interference behavior between the crack and hole at various hole locations of the crack–hole interference model are well recognized by this model. The crack propagation behavior under different electrical load intensities is also considered. The results show that the hole in front of the crack tip inhibits crack propagation to a certain extent, and the strength of electrical load affects the fatigue life of piezoelectric materials and structures. Therefore, the proposed electrical mixed-mode fatigue crack propagation model provides a reference for predicting the mixed-mode fatigue crack propagation behavior and fatigue life of piezoelectric structures under electric fatigue loading.

关键词： Configurational force J_(k)-integral Piezoelectric Mixed-mode crack propagation life prediction