检索结果-南通市图书馆

Direction finding of bistatic MIMO radar in strong impulse noise

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2024年第4期35卷 888-898页

作者： CHEN Menghan GAO Hongyuan DU Yanan CHENG Jianhua zhang yuze College of Information and Communication Engineering Harbin Engineering UniversityHarbin 150001China College of Intelligent Systems Science and Engineering Harbin Engineering UniversityHarbin 150001China

For bistatic multiple-input multiple-output(MIMO)radar,this paper presents a robust and direction finding method in strong impulse noise *** means of a new lower order covariance,the method is effective in suppressing impulse noise and achieving superior direction finding performance using the maximum likelihood(ML)estimation method.A quantum equilibrium optimizer algorithm(QEOA)is devised to resolve the corresponding objective function for efficient and accurate direc-tion *** results of simulation reveal the capability of the presented method in success rate and root mean square error over existing direction-finding methods in different application situations,e.g.,locating coherent signal sources with very few snapshots in strong impulse *** than that,the Cramér-Rao bound(CRB)under impulse noise environment has been drawn to test the capability of the presented method.

关键词： bistatic multiple-input multiple-output(MIMO)radar impulse noise direction finding lower order covariance quan-tum equilibrium optimizer algorithm(QEOA) maximum likeli-hood estimation method Cramér-Rao bound(CRB)

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

动态牵伸过程中浮游纤维变速点分布模拟

纺织学报 2024年第3期45卷 44-48页

作者：范居乐张玉泽汪军东华大学纺织学院上海201620

为研究牵伸条件的变化对牵伸过程的影响,通过建立动态牵伸模型,仿真浮游纤维在动态牵伸过程中受到摩擦力作用的加速过程,得到动态牵伸过程中浮游纤维变速点分布。纤维的牵伸过程被细化为后纤维、慢浮游纤维、快浮游纤维和前纤维4种纤维... 详细信息

为研究牵伸条件的变化对牵伸过程的影响,通过建立动态牵伸模型,仿真浮游纤维在动态牵伸过程中受到摩擦力作用的加速过程,得到动态牵伸过程中浮游纤维变速点分布。纤维的牵伸过程被细化为后纤维、慢浮游纤维、快浮游纤维和前纤维4种纤维运动状态变化的过程。通过记录纤维在牵伸过程中速度和位置的变化,计算得到纤维保持每种状态的时间。模拟过程中,通过获取纤维在牵伸过程中速度和位置的变化,得到每根纤维在牵伸区内分别维持4种运动状态的时间,从而建立动态的牵伸模型。此外,通过确定浮游纤维与快速纤维和慢速纤维相互接触的长度,计算浮游纤维在动态牵伸过程中受到的控制力与引导力,模拟浮游纤维在动态牵伸过程中的加速过程。同时计算简单罗拉牵伸的摩擦力界分布,通过改变牵伸模型的牵伸倍数和纤维长度,模拟不同牵伸条件下浮游纤维变速点分布。结果表明:仿真得到的变速点分布近似于正态分布,与实际牵伸过程中变速点分布形态接近;牵伸倍数越大,纤维的长度越长,变速点分布越接近前罗拉,并且变速点分布范围越小。

关键词：动态牵伸模型牵伸浮游纤维变速点分布纤维运动状态摩擦力界分布

在线全文

学校读者我要写书评

暂无评论

集聚赛络纺纱导流装置的设计与应用

毛纺科技 2024年第3期52卷 38-43页

作者：孔祥江张玉泽江慧汪军东华大学纺织学院上海201620

针对集聚赛络纺纱系统能耗较大的问题,设计3种导流装置,以降低集聚赛络纺纱系统的负压,达到节能降耗的效果。首先通过solidworks软件建立集聚赛络纺纱集聚区三维物理模型,利用fluent进行数值模拟,分析集聚区气流场的分布情况;然后通过... 详细信息

针对集聚赛络纺纱系统能耗较大的问题,设计3种导流装置,以降低集聚赛络纺纱系统的负压,达到节能降耗的效果。首先通过solidworks软件建立集聚赛络纺纱集聚区三维物理模型,利用fluent进行数值模拟,分析集聚区气流场的分布情况;然后通过纺纱实验进一步验证导流装置能够起到节能降耗的效果。结果表明:出口负压越大,集聚槽附近的速度越大,集聚槽上方的气流对须条起到挤压作用,使须条紧紧贴在网格圈表面,集聚槽侧向气流使须条宽度减小,须条表面的毛羽能够卷入到纱体表面,形成紧密的结构,从而能够减小甚至消除加捻三角区;使用所设计的3种导流装置(集聚负压1000 Pa)纺制出来的纱线与普通集聚赛络纱(集聚负压2000 Pa)质量相当,甚至更好。

关键词：集聚赛络纺导流装置数值模拟纱线质量检测

Recovery of Li_(2)CO_(3)and FePO_(4)from spent LiFePO_(4)by coupling technics of isomorphic substitution leaching and solvent extraction

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2023年第2期54卷 306-315页

作者： Yong Niu Xiaowu Peng Jinfeng Li yuze zhang Fugen Song Dong Shi Lijuan Li Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources Engineering Laboratory for Green Applications of Salt Lakes and Salt DepositsQinghai Institute of Salt LakesChinese Academy of SciencesXining 810008China Qinghai Technology Research and Development Center of Comprehensive Utilization of Salt Lakes Resources Xining 810008China Shanghai Institute of Organic Chemistry Chinese Academy of SciencesShanghai 200032China University of Chinese Academy of Sciences Beijing 100049China Innovation Academy for Green Manufacture Chinese Academy of SciencesBeijing 100190China

Efficient and low-cost recycling of spent lithium iron phosphate(LiFePO_(4),LFP)batteries has become an inevitable *** this study,an integrated closed-loop recycling strategy including isomorphic substitution leaching and solvent extraction process for spent LFP was *** inexpensive FeCl_(3)was used as leaching agent to directly substitute Fe^(2+)from LFP.99%of Li can be rapidly leached in just 30 min,accompanied by 98%of FePO_(4)precipitated in *** tri-n-butyl phosphate(TBP)-sulfonated kerosene(SK)system was applied to extract Li from lixivium through a twelve-stage countercurrent process containing synchronous extraction and stepwise stripping of Li^(+)and Fe^(3+).80.81%of Li can be selectively enriched in stripping liquor containing 3.059 mol·L^(-1)of Li^(+)under optimal *** the Fe stripping liquor was recovered for LFP re-leaching,of which,Fe^(2+)was oxidized to Fe^(3+)by appropriate H_(2)O_(2).Raffinate and lixivium were concentrated and entered into extraction process to accomplished closeloop recycling ***,the results suggest that more than 99%of Li was ***_(3)holding in solution was directly regenerated without any pollutant *** sustainable mothed would be an alternative candidate for total element recycling of spent LFP batteries with industrial potential.

关键词： Spent LiFePO_(4) Leaching lithium Extraction Stripping Recovery

In-situ 3D contour measurement for laser powder bed fusion based on phase guidance

在线全文

学校读者我要写书评

暂无评论

Theoretical & Applied Mechanics Letters 2023年第2期13卷 113-119页

作者： yuze zhang Pan zhang Xin Jiang Siyuan zhang Kai Zhong Zhongwei Li State Key Lab of Materials Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan430074China Research Institute of Huazhong University of Science and Technology in Shenzhen Shenzhen51800China

In-situ layerwise imaging measurement of laser powder bed fusion(LPBF)provides a wealth of forming and defect data which enables monitoring of components quality and powder bed *** high-resolution camera layerwise imaging and image processing algorithms to monitor fusion area and powder bed geometric defects has been studied by many researchers,which successfully monitored the contours of components and evaluated their ***,research for the methods of in-situ 3D contour measurement or component edge warping identification is *** this study,a 3D contour mea-surement method combining gray intensity and phase difference is proposed,and its accuracy is verified by designed *** results show that the high-precision of the 3D contours can be achieved by the constructed energy minimization *** method can detect the deviations of common ge-ometric features as well as warpage at LPBF component edges,and provides fundamental data for in-situ quality monitoring tools.

关键词： Laser powder bed fusion In-situ measurement Active contours 3D contour Measurement accuracy

基于网络药理学与细胞实验探讨加味黄芪桂枝五物汤治疗类风湿关节炎的作用机制

在线全文

学校读者我要写书评

暂无评论

河南中医 2024年第4期44卷 542-548页

作者：徐俊张彦红陈姣姣张雨泽庄丽华湖北中医药大学湖北武汉430065

目的:基于网络药理学与细胞实验探讨加味黄芪桂枝五物汤治疗类风湿关节炎(rheumatoid arthritis, RA)的作用机制。方法:通过中药系统药理学数据库与分析平台(Traditional Chinese Medicine Systems Pharmacology Database and Analysis ... 详细信息

目的:基于网络药理学与细胞实验探讨加味黄芪桂枝五物汤治疗类风湿关节炎(rheumatoid arthritis, RA)的作用机制。方法:通过中药系统药理学数据库与分析平台(Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform, TCMSP)、BATMAN-TCM数据库检索并筛选加味黄芪桂枝五物汤的活性成分和作用靶点。在GeneCards数据库、OMIM数据库检索RA的作用靶点,将加味黄芪桂枝五物汤与RA的靶点取交集。通过Bioconductor平台和R软件对交集基因进行基因本体(Gene Ontology, GO)分析和京都基因与基因组百科全书(Kyoto Encyclopedia of Genes and Genomes, KEGG)分析。将20只SD大鼠随机分为加味黄芪桂枝五物汤组(1.8 g·kg^(-1))和正常组,每组各10只。灌胃7 d后,制备体积分数为5%、10%、20%的含药血清。利用CCK-8法检测MH7A细胞的增殖情况;Annexin V-PI双染色法检测MH7A细胞凋亡情况;Western Blot检测MH7A细胞磷脂酰肌醇-3-激酶(phosphatidylinositol-3-hydroxykinase, PI3K)、磷酸化蛋白激酶B(phosphorylated protein kinase B,p-AKT)蛋白表达水平;ELISA检测MH7A细胞白细胞介素-17(interleukin-17,IL-17)、白细胞介素-6(interleukin-6,IL-6)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)含量。结果:共检索加味黄芪桂枝五物汤的活性成分141个,作用靶点303个。RA的作用靶点4 937个,加味黄芪桂枝五物汤与RA的交集靶点127个。GO分析主要涉及对脂多糖的反应、对细胞增殖的负反馈调节、对细胞因子的反应、细胞活化调节、细胞凋亡过程的正调节等。KEGG通路主要包括PI3K/AKT信号通路、TNF信号通路、钙信号通路等。细胞培养12 h、24 h、48 h时,与对照组比较,加味黄芪桂枝五物汤高剂量组、中剂量组与低剂量组细胞的增殖抑制率升高(P<0.05)。细胞培养24 h时,与对照组比较,加味黄芪桂枝五物汤低剂量组、中剂量组、高剂量组细胞凋亡率增加(P<0.05)。与对照组比较,模型组细胞PI3K、p-AKT表达水平升高(P<0.05);与模型组比较,加味黄芪桂枝五物汤低剂量组、中剂量组、高剂量组细胞PI3K、p-AKT表达水平降低(P<0.05)。与对照组比较,模型组细胞IL-17、TNF-α、IL-6含量升高(P<0.05);与模型组比较,加味黄芪桂枝五物汤低剂量组、中剂量组、高剂量组细胞IL-17、TNF-α、IL-6含量下降(P<0.05)。结论:加味黄芪桂枝五物汤可能通过调节PI3K/AKT信号通路等相关途径、抑制MH7A细胞增殖、促进细胞凋亡、降低炎症因子水平,从而发挥抗RA的作用。

关键词：类风湿关节炎加味黄芪桂枝五物汤 PI3K/AKT信号通路网络药理学细胞增殖细胞凋亡《金匮要略》张仲景

在线全文

学校读者我要写书评

暂无评论

钢纤维混凝土抗冻性及损伤模型研究

湖北工业大学学报 2024年第1期39卷 97-100,115页

作者：易怀书陈月顺李传雄张玉泽湖北工业大学土木工程与建筑学院湖北武汉430068

选取钢纤维掺量为0%、1.5%,基体混凝土强度等级为C30、C40的混凝土试件进行冻融试验与抗压强度试验,研究其质量损失率变化规律及抗压强度衰减规律。以得到的抗压强度数据为损伤变量建立三种不同的函数模型。结果表明:冻融循环200次后,2... 详细信息

选取钢纤维掺量为0%、1.5%,基体混凝土强度等级为C30、C40的混凝土试件进行冻融试验与抗压强度试验,研究其质量损失率变化规律及抗压强度衰减规律。以得到的抗压强度数据为损伤变量建立三种不同的函数模型。结果表明:冻融循环200次后,2组钢纤维混凝土试件组较素混凝土试件组的质量损失率减少了0.69%和1.09%,抗压强度损失率减少了3.9%和4.0%,说明钢纤维的掺入减小了混凝土强度的衰减以及冻融损伤。对三种函数所拟合的损伤模型相关系数进行比较,基于二项式函数所拟合的损伤模型精度最高,相关系数均超过0.95。

关键词：钢纤维冻融力学性能损伤模型

在线全文

学校读者我要写书评

暂无评论

聚丙烯纤维混凝土抗冻性能研究

湖北工业大学学报 2024年第1期39卷 106-110页

作者：李传雄陈月顺易怀书张玉泽湖北工业大学土木工程与建筑学院湖北武汉430068

为提高混凝土在冻融环境下的耐久性,研究0.9 kg/m^(3)聚丙烯纤维掺量下混凝土等级和冻融循环次数两种因素对混凝土抗压强度和质量损失的影响。将C40、C50素混凝土和同等级聚丙烯纤维混凝土进行50、100、150、200次冻融循环试验。使用ori... 详细信息

为提高混凝土在冻融环境下的耐久性,研究0.9 kg/m^(3)聚丙烯纤维掺量下混凝土等级和冻融循环次数两种因素对混凝土抗压强度和质量损失的影响。将C40、C50素混凝土和同等级聚丙烯纤维混凝土进行50、100、150、200次冻融循环试验。使用origin软件进行试验数据分析,并对建立抗压强度损伤模型。结果表明:冻融0次时,添加聚丙烯纤维对C40、C50素混凝土的抗压强度分别提高了4.2%和3.8%,随着冻融次数达200次时,聚丙烯纤维的加入使混凝土抗压强度损失率减小了7.9%和5.5%,说明聚丙烯纤维混凝土抗冻性优于普通混凝土。在试验数据的基础上,理论分析了不同配合比聚丙烯纤维混凝土冻融循环后抗压强度损伤规律,建立了混凝土冻融破坏后的力学性能损伤规律模型。

关键词：聚丙烯纤维冻融循环试验抗压强度强度损伤模型

THE STRUCTURE-PRESERVING METHODS FOR THE DEGASPERIS-PROCESI EQUATION

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2019年第4期37卷 475-487页

作者： yuze zhang Yushun Wang Yanhong Yang Department of Applied Mathematics The Hongkong Polytechnic University China Jiangsu Key Laboratory of NSLSCS School of Mathematical Sciences Nanjing Normal University Nanjing 210023 China Department of Mathematics College of Taizhou Nanjing Normal University Taizhou 225300 China

This paper gives several structure-preserving schemes for the Degasperis-Procesi equation which has bi-Hamiltonian structures consisted of both complex and non-local Hamiltonian differential operators. For this sake, few structure-preserving schemes have been proposed so far. In our work, based on one of the bi-Hamiltonian structures, a symplectic scheme and two new energy-preserving schemes are constructed. The symplecticity comes straightly from the application of the implicit midpoint method on the semi-discrete system which is proved to remain Hamiltonian, while the energy conservation is derived by the combination of the averaged vector field method of second and fourth order, respectively. Some numerical results are presented to show that the three schemes do have the advantages in numerical stability, accuracy in long time computing and ability to preserve the invariants of the DP equation.

关键词： Degasperis-Procesi equation bi-Hamiltonian structure Structure-preserving scheme Fourier pseudospectral method