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

基于最大离差与熵法的弹道导弹威胁度评估

中国电子科学研究院学报 2022年第5期17卷 484-488页

作者：李翔晨张亦弛南京电子技术研究所江苏南京210039 中国人民解放军63768部队陕西西安710600

弹道导弹威胁度评估是导弹预警系统工作流程中的重要一环。针对多方向多批次导弹来袭的复杂作战场景特点,对影响弹道导弹威胁度的主要因素进行分析,建立弹道导弹威胁度评估指标体系。参考现有威胁度评估指标体系权值确定方法,运用最大... 详细信息

弹道导弹威胁度评估是导弹预警系统工作流程中的重要一环。针对多方向多批次导弹来袭的复杂作战场景特点,对影响弹道导弹威胁度的主要因素进行分析,建立弹道导弹威胁度评估指标体系。参考现有威胁度评估指标体系权值确定方法,运用最大离差与熵法对弹道导弹威胁度评估指标进行权值确定。通过仿真实验进行定量分析,验证了最大离差与熵法在弹道导弹威胁度评估中的可用性。对支撑导弹预警系统进一步优化发展具有应用价值。

关键词：最大离差与熵弹道导弹威胁度评估导弹预警系统

在线全文

学校读者我要写书评

暂无评论

跨地域项目管理与监理分析

中国科技纵横 2018年第11期 120-121页

作者：李祥辰北京赛迪工业和信息化工程监理中心有限公司北京100048

随着我国信息化建设的不断深入,不同行业都在进行综合信息化管理平台进行分级业务管理,平台呈现跨地域、分层分级管理的特点.由此产生了跨地域目工程管理与监理问题,因而监理公司须根据不同地域的实际情况,制定符合项目管理流程及自身... 详细信息

随着我国信息化建设的不断深入,不同行业都在进行综合信息化管理平台进行分级业务管理,平台呈现跨地域、分层分级管理的特点.由此产生了跨地域目工程管理与监理问题,因而监理公司须根据不同地域的实际情况,制定符合项目管理流程及自身利益的工程监理模式、监理架构、监理流程等,达到控制项目投资、进度和质量的目标,并对项目进行合同与信息管理,使项目建设管理内外协调,工作关系和谐一致.本文以下内容将对跨地域项目管理与监理进行简要的探讨,以供大家参考学习之用.

关键词：跨地域项目监理监理分析

来源：评论

学校读者我要写书评

暂无评论

火箭整流罩内降噪装置低频声学性能仿真

北京理工大学学报 2016年第10期36卷 991-995页

作者：荣吉利谌相宇赵瑞秦朝红任方北京理工大学宇航学院北京100081 北京强度环境研究所北京100076

针对运载火箭整流罩内降噪装置所具有的特殊曲线颈部Helmholtz共鸣器,基于仿真方法研究降噪装置的低频声学性能.应用虚拟阻抗管法分析了Helmholtz共鸣器共振频率及吸声系数与其壁面厚度的变化关系.研究了降噪装置不同安装位置对圆柱空... 详细信息

针对运载火箭整流罩内降噪装置所具有的特殊曲线颈部Helmholtz共鸣器,基于仿真方法研究降噪装置的低频声学性能.应用虚拟阻抗管法分析了Helmholtz共鸣器共振频率及吸声系数与其壁面厚度的变化关系.研究了降噪装置不同安装位置对圆柱空腔内平均声压级的影响.仿真结果表明,随着壁面厚度增加,Helmholtz共鸣器共振频率逐渐趋于刚性壁面的值,但吸声系数先增大后减小.降噪装置不同的安装位置可使空腔内平均声压级相差10dB以上,在工程应用中需将其放置于空腔模态振幅较大的位置.

关键词： Helmholtz共鸣器整流罩低频噪声降噪

基于物质平衡的页岩气井压裂改造裂缝体积与面积计算

在线全文

学校读者我要写书评

暂无评论

天然气地球科学 2017年第7期28卷 1059-1064页

作者：杨斌游利军康毅力何志君李相臣西南石油大学"油气藏地质及开发工程"国家重点实验室四川成都610500 中国石化西南油气分公司川西采气厂四川德阳618000

页岩气井的压后排采过程呈现明显的阶段性特征,根据生产气液比与累积产气量的关系曲线可将整个排采阶段划分为早期阶段和晚期阶段。在排采生产早期,气井表现为气液同产,并以产液为主,此时页岩基质向裂缝系统的供气能力不足,整个水力裂... 详细信息

页岩气井的压后排采过程呈现明显的阶段性特征,根据生产气液比与累积产气量的关系曲线可将整个排采阶段划分为早期阶段和晚期阶段。在排采生产早期,气井表现为气液同产,并以产液为主,此时页岩基质向裂缝系统的供气能力不足,整个水力裂缝系统(主压裂缝、次级压裂缝及沟通天然裂缝)可视为封闭体系。从物质平衡原理出发,建立了基于排采早期阶段生产数据的压裂裂缝初始体积和面积的计算模型,并以龙马溪组典型页岩气井进行了实例分析。结果显示,分析井的裂缝体积为注入压裂液量的70%左右,裂缝面积可达10~7 m^2量级,较大的改造裂缝面积也说明压裂形成了较复杂的缝网,提高了气井有效泄流面积。该模型解释结果与页岩气井排采参数和产气能力吻合良好,是评价压裂裂缝参数和改造效果的有效途径,对矿场水力压裂效果评估具有指导意义。

关键词：页岩气排采阶段物质平衡裂缝体积裂缝面积

Exosomes originating from neural stem cells undergoing necroptosis participate in cellular communication by inducing TSC2 upregulation of recipient cells following spinal cord injury

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第11期20卷 3273-3286页

作者： Shiming li Jianfeng li Guoliang chen Tao lin Penghui Zhang Kuileung Tong Ningning chen Shaoyu liu Shenzhen Key Laboratory of Bone Tissue Repair and Translational Research Department of Orthopedic SurgeryThe Seventh Affiliated HospitalSun Yat-sen UniversityShenzhenGuangdong ProvinceChina Department of Orthopedic Surgery The First Affiliated Hospital of Jinan UniversityGuangzhouGuangdong ProvinceChina Department of Orthopedics and Traumatology Zhujiang HospitalSouthern Medical UniversityGuangzhouGuangdong ProvinceChina Department of Orthopedic Surgery The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhouGuangdong ProvinceChina Department of Orthopedic Surgery The First Affiliated Hospital of Sun Yat-sen UniversityGuangzhouGuangdong ProvinceChina

We previously demonstrated that inhibiting neural stem cells necroptosis enhances functional recovery after spinal cord *** exosomes are recognized as playing a pivotal role in neural stem cells exocrine function,their precise function in spinal cord injury remains *** investigate the role of exosomes generated following neural stem cells necroptosis after spinal cord injury,we conducted singlecell RNA sequencing and validated that neural stem cells originate from ependymal cells and undergo necroptosis in response to spinal cord ***,we established an in vitro necroptosis model using neural stem cells isolated from embryonic mice aged 16-17 days and extracted *** results showed that necroptosis did not significantly impact the fundamental characteristics or number of *** sequencing of exosomes in necroptosis group identified 108 differentially expressed messenger RNAs,104 long non-coding RNAs,720 circular RNAs,and 14 microRNAs compared with the control *** of a competing endogenous RNA network identified the following hub genes:tuberous sclerosis 2(Tsc2),solute carrier family 16 member 3(Slc16a3),and forkhead box protein P1(Foxp1).Notably,a significant elevation in TSC2 expression was observed in spinal cord tissues following spinal cord ***2-positive cells were localized around SRY-box transcription factor 2-positive cells within the injury ***,in vitro analysis revealed increased TSC2 expression in exosomal receptor cells compared with other *** assessment of cellular communication following spinal cord injury showed that Tsc2 was involved in ependymal cellular communication at 1 and 3 days post-injury through the epidermal growth factor and midkine signaling *** addition,Slc16a3 participated in cellular communication in ependymal cells at 7 days post-injury via the vascular endothelial growth factor and macrophage migration inhibitory factor signaling

关键词： cellular communication competing endogenous RNA exosomes Foxp1 necroptosis neural stem cells Slc16a3 spinal cord injury transcriptome sequencing Tsc2

Transforming growth factor-beta 1 enhances discharge activity of cortical neurons

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第2期20卷 548-556页

作者： Zhihui Ren Tian li Xueer liu Zelin Zhang Xiaoxuan chen Weiqiang chen Kangsheng li Jiangtao Sheng Department of Microbiology and Immunology Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular ImmunopathologyShantou University Medical CollegeShantouGuangdong ProvinceChina Department of Neurosurgery First Affiliated Hospital of Shantou University Medical CollegeShantouGuangdong ProvinceChina

Transforming growth factor-beta 1(TGF-β1)has been extensively studied for its pleiotropic effects on central nervous system *** neuroprotective or neurotoxic effects of TGF-β1 in specific brain areas may depend on the pathological process and cell types ***-gated sodium channels(VGSCs)are essential ion channels for the generation of action potentials in neurons,and are involved in various neuroexcitation-related ***,the effects of TGF-β1 on the functional properties of VGSCs and firing properties in cortical neurons remain *** this study,we investigated the effects of TGF-β1 on VGSC function and firing properties in primary cortical neurons from *** found that TGF-β1 increased VGSC current density in a dose-and time-dependent manner,which was attributable to the upregulation of Nav1.3 *** VGSC current density and Nav1.3 expression were significantly abolished by preincubation with inhibitors of mitogen-activated protein kinase kinase(PD98059),p38 mitogen-activated protein kinase(SB203580),and Jun NH2-terminal kinase 1/2 inhibitor(SP600125).Interestingly,TGF-β1 significantly increased the firing threshold of action potentials but did not change their firing rate in cortical *** findings suggest that TGF-β1 can increase Nav1.3 expression through activation of the ERK1/2-JNK-MAPK pathway,which leads to a decrease in the firing threshold of action potentials in cortical neurons under pathological ***,this contributes to the occurrence and progression of neuroexcitatory-related diseases of the central nervous system.

关键词： central nervous system cortical neurons ERK firing properties JNK Nav1.3 p38 transforming growth factor-beta 1 traumatic brain injury voltage-gated sodium currents

Real-world evidence on the efficacy and safety of vonoprazanamoxicillin dual therapy for Helicobacter pylori treatment in elderly patients

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2025年第1期31卷 68-78页

作者： Wen Gao Jing-Wen li Hui Ye Xue-Zhi Zhang Jian-xiang liu Hong cheng Department of Gastroenterology Peking University First HospitalBeijing 100034China School of Medicine Tsinghua MedicineTsinghua UniversityBeijing 100034China Department of Traditional Chinese Medicine and Integrative Medicine Peking University First HospitalBeijing 100034China

BACKGROUND A dual therapy regimen containing amoxicillin is a common treatment option for the eradication of Helicobacter pylori(***).While substantial research supports the efficacy and safety of vonoprazan and amoxicillin(VA)dual therapy in the general population,there is still a lack of studies specifically focusing on its safety in elderly *** To evaluate efficacy and safety of VA dual therapy as first-line or rescue treatment for *** in elderly *** As a real-world retrospective study,data were collected from elderly patients aged 60 years and above who accepted VA dual therapy(vonoprazan 20 mg twice daily+amoxicillin 1000 mg thrice daily for 14 days)for *** eradication in the Department of Gastroenterology at Peking University First Hospital between June 2020 and January *** status was evaluated by^(13)C-urease breath test 6 weeks after *** adverse events(AEs)during treatment were *** In total,401 cases were ***-one cases were excluded due to loss to follow-up,lack of re-examination,or unwillingness to take *** total of 380 included cases comprised 250 who received VA dual therapy as first-line treatment and 130 who received VA dual therapy as rescue *** was successfully eradicated in 239 cases(95.6%)in the first-line treatment group and 116 cases(89.2%)in the rescue treatment *** overall incidence of AEs was 9.5%for both ***,9.2%of patients experienced an AE in the first-line treatment group and 10.0%in the rescue treatment *** patients discontinued treatment due to AE,with a discontinuation rate of 1.3%.No serious AE *** The VA dual therapy regimen as a first-line treatment and a rescue therapy was effective and safe for elderly patients aged 60 and older.

关键词： Helicobacter pylori Vonoprazan Amoxicillin Dual therapy Elderly

Multiphase reaction spinning of high-temperature resistant weavable SiO_(2)-Kevlar hybrid aerogel fibers

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

Nano Research 2025年第1期18卷 424-433页

作者： Yunna chen Wenlu Zhang Qingyang li Wenbin li Chong He School of Textile Science and Engineering Wuhan Textile UniversityWuhan 430200China State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile UniversityWuhan 430200China

Advanced aerogel fibers possess numerousadvantages amalgamating the attributes of aerogels and fibermaterials, rendering them invaluable in the realm of thermalmanagement and regulation. However, the achievement ofrobust mechanical properties and increased temperaturestability is still a major challenge for the majority of aerogelfibers. Herein, SiO_(2)-Kevlar hybrid aerogel fibers with bioniccore-shell structure were prepared by reaction spinning andweaved into fabric. Kevlar nanowires dispersion is pumpedinto a bath comprising a self-synthesized silica sol, whichfacilitates the hybridization of biphasic aerogels through thegel reaction. Precise control over the diameter (200-800 μm)and structure of the wet gel fibers was achieved throughmeticulous adjustment of the spinning solution composition and spinning parameters. Subsequent freeze-drying processfacilitates the formation of a core-shell hybrid structure, in which the SiO_(2) aerogel layer effectively encapsulate the Kevlaraerogel core fiber. Taking full advantage of the mechanical properties of the Kevlar core fiber, the resulting SiO_(2)-Kevlaraerogel fibers exhibit commendable weaving characteristics (51.8 MPa). Furthermore, SiO_(2)-Kevlar aerogel fabrics exhibitenhanced thermal insulation characteristics with a thermal conductivity of 0.037 W/(m·K). As a result of the presence ofexternal SiO_(2) aerogel layer, the overall temperature resistance performance of the SiO_(2)-Kevlar fabric reach up to 700 ℃.

关键词： aerogel fibers SiO_(2)aerogel Kevlar aerogel reaction spinning thermal protective performance

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

基于地形信息的平流层通信系统传播衰减预测

上海交通大学学报 2002年第5期36卷 678-682页

作者：李霄翔何晨诸鸿文上海交通大学电子工程系上海200030

给出了一种基于地形信息的预测平流层通信系统大尺度衰落的算法 ,包括地形重建和传播衰减计算 ,及编程实现的方法 .计算出了平流层空中平台到某一区域的大尺度传播衰减 ,并根据该算法针对地形变化对传播衰减的影响进行了仿真 .结果表明 ... 详细信息

给出了一种基于地形信息的预测平流层通信系统大尺度衰落的算法 ,包括地形重建和传播衰减计算 ,及编程实现的方法 .计算出了平流层空中平台到某一区域的大尺度传播衰减 ,并根据该算法针对地形变化对传播衰减的影响进行了仿真 .结果表明 ,平流层通信系统的传播衰减受地形变化的影响比地面通信系统小得多 .在没有平流层通信实测数据的情况下 ,上述预测算法对仿真通信系统性能具有重要意义 .

关键词：平流层通信大尺度衰减基于地形信息传播衰减反射绕射