检索结果-南通市图书馆

改进位姿估计环节的ORB-SLAM稠密建图算法

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

科学技术与工程 2024年第7期24卷 2782-2789页

作者：刘畅党淑雯陈丽上海工程技术大学航空运输学院上海201600

为提高ORB-SLAM2 (oriented fast and rotated brief, and simultaneous localization and mapping)系统的位姿估计精度并解决仅能生成稀疏地图的问题,提出了融合迭代最近点拟合(iterative closest point, ICP)算法与曼哈顿世界假说的位姿估计策略并在系统中加入稠密建图线程。首先通过ORB(oriented fast and rotated brief)特征点法、最小显著性差异(least-significant difference, LSD)算法和聚集层次聚类(agglomerative hierarchical clustering, AHC)方法提取点、线、面特征,其中点、线特征与上一帧匹配,面特征在全局地图匹配。然后采用基于surfel的稠密建图策略将图像划分为非平面与平面区域,非平面采用ICP算法计算位姿,平面则通过面与面的正交关系确定曼哈顿世界从而使用不同估计策略,其中曼哈顿世界场景通过位姿解耦实现基于曼哈顿帧观测的无漂移旋转估计,而该场景的平移以及非曼哈顿世界场景的位姿采用追踪的点、线、面特征进行估计和优化;最后根据关键帧和相应位姿实现稠密建图。采用慕尼黑工业大学(technische universit?t münchen, TUM)数据集验证所提建图方法,经过与ORB-SLAM2算法比较,均方根误差平均减少0.24 cm,平均定位精度提高7.17%,验证了所提方法进行稠密建图的可行性和有效性。

关键词：位姿估计平面曼哈顿世界假说同步定位与建图稠密建图

在线全文

学校读者我要写书评

暂无评论

中药微针:创新的中药给药方式

沈阳药科大学学报 2024年第7期41卷 817-825页

作者：党海涛周彦君党文李宁沈阳药科大学中药学院辽宁省重大慢病中药创新药重点实验室/沈阳市中药药效物质研究与创新药开发重点实验室辽宁沈阳110016

中药微针是一种将中药活性成分直接递送至表皮层或真皮层的新型给药方式,可大大减轻患者的痛感,提高透皮给药效率,且能绕过传统中药口服的肝脏首过效应。本文阐述了中药微针的概念、研究进展、存在的问题以及其发展前景。进一步通过介... 详细信息

中药微针是一种将中药活性成分直接递送至表皮层或真皮层的新型给药方式,可大大减轻患者的痛感,提高透皮给药效率,且能绕过传统中药口服的肝脏首过效应。本文阐述了中药微针的概念、研究进展、存在的问题以及其发展前景。进一步通过介绍中药微针的制备方法和设计因素,总结出影响中药微针机械强度、载药量和透皮深度的主要因素,为中药微针的优化设计提供了参考。

关键词：中药微针可溶微针微针制备微针设计

基于HPLC指纹图谱结合化学模式识别法对黄芪不同炮制品多指标成分分析研究

在线全文

学校读者我要写书评

暂无评论

天然产物研究与开发 2024年第6期36卷 993-1003页

作者：周晶晶周洁张红伟党文飞窦霞靳子明甘肃中医药大学甘肃中医药大学附属医院杨锡仓全国名老中医药专家工作室兰州730030

本研究通过建立黄芪不同炮制品HPLC指纹图谱及多成分含量测定方法,并结合化学计量法对其进行比较分析,为黄芪炮制品的综合利用提供理论支持。采用HPLC建立黄芪炮制品指纹图谱并进行6种成分的含量测定,并通过聚类分析(hierarchical clust... 详细信息

本研究通过建立黄芪不同炮制品HPLC指纹图谱及多成分含量测定方法,并结合化学计量法对其进行比较分析,为黄芪炮制品的综合利用提供理论支持。采用HPLC建立黄芪炮制品指纹图谱并进行6种成分的含量测定,并通过聚类分析(hierarchical clustering analysis,HCA)、主成分分析(principal component analysis,PCA)和正交偏最小二乘-判别分析(orthogonal partial least squares discriminant analysis,OPLS-DA)评价不同黄芪炮制品的差异,找寻差异性成分。结果显示,不同炮制品(各10批)共得到20个共有峰,其中指认了6个共有峰,且6个成分在各自的质量浓度范围内线性关系良好(r>0.999),平均加样回收率为100.5%~102.1%,相对标准偏差(relative standard deviation,RSD)为0.77%~2.1%;指纹图谱相似度结果显示,蜜麸黄芪、蜜炙黄芪、盐黄芪、酒黄芪各自10批的相似度均在0.900以上,但不同类型炮制品的相似度降低;聚类分析可将四种炮制品聚为3类,主成分分析与聚类分析结果一致,可相互佐证,正交偏最小二乘-判别分析能有效的将4种炮制品区分,以变量重要性投影(variable importance of projection,VIP)大于1为依据,筛选了9种主要差异成分,确认了毛蕊异黄酮苷、芒柄花苷、5-羟甲基糠醛是引起黄芪不同炮制品间成分差异的主要标志性成分。该研究所建立的黄芪炮制品HPLC指纹图谱结合化学计量法的方法准确可靠,可为黄芪炮制品的质量控制和品质评价提供参考依据。

关键词：黄芪 HPLC 指纹图谱含量测定化学模式识别质量评价

同方期刊数据库

口蹄疫病毒等小RNA病毒可通过一种共性机制操纵细胞加速病毒复制

在线全文

学校读者我要写书评

暂无评论

中国兽医科学 2024年第7期54卷 993-993页

作者： Ruoqing Mao Zixiang Zhu Fan Yang Dehui Sun Xiaoli Zhou Weijun Cao Xiaodong Qin wen dang Huanan Liu Hong Tian Keshan Zhang Qingfeng Wu Xiangtao Liu Haixue Zheng State Key Laboratory for Animal Disease Control and Prevention College of Veterinary Medicine Lanzhou University Lanzhou Veterinary Research Institute Chinese Academy of Agricultural Sciences Lanzhou China. Analysis and Test Group Center for Technical Development and Analysis Service Institute of Modern Physics Chinese Academy of Sciences Lanzhou China.

小RNA病毒是RNA病毒中最小的类群。这种病毒的颗粒为直径22~30 nm的正二十面体,无包膜,并且含有29%~32%的连续线型单链RNA。小RNA病毒科的主要成员包括口蹄疫病毒(FMDV)、脊髓灰质炎病毒(PV)、塞内卡病毒(SVA)、埃可病毒、柯萨奇病毒等... 详细信息

小RNA病毒是RNA病毒中最小的类群。这种病毒的颗粒为直径22~30 nm的正二十面体,无包膜,并且含有29%~32%的连续线型单链RNA。小RNA病毒科的主要成员包括口蹄疫病毒(FMDV)、脊髓灰质炎病毒(PV)、塞内卡病毒(SVA)、埃可病毒、柯萨奇病毒等,能引起多种人或动物传染性疾病,对人和动物的健康构成威胁。小RNA病毒的VP3蛋白是病毒结构中的关键组成部分,尤其在口蹄疫病毒、脊髓灰质炎病毒和塞内卡病毒等病毒中,VP3蛋白被视为病毒复制和致病过程中的关键毒力因子。

关键词：口蹄疫病毒 VP3蛋白病毒结构脊髓灰质炎病毒小RNA病毒致病过程病毒复制毒力因子

Long-term improvements in water conservation functions at Qilian Mountain National Park, northwest China

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2023年第10期20卷 2885-2897页

作者： GAO Xiang HUANG Xing-xing CHANG Shu-hang dang Qian-wen wen Rui-yang LO Kevin LI Jie YAN An College of Earth and Environmental Sciences Lanzhou UniversityLanzhou 730000China Department of Geography Hong Kong Baptist UniversityHong Kong 999077China

Water conservation is one of the most important ecosystem *** study uses the InVEST model to examine the water conservation function of the Qilian Mountain National Park(QMNP),an important water supply area in northwest *** analyzed the spatiotemporal water conservation patterns of QMNP from 1988 to *** showed that the water conservation capacity in QMNP has increased over the past 32 years,reaching a peak of 6.495×108 m3 in *** area with an increased water conservation capacity is 12 times larger than the area with a reduced *** also examined how climatic,land-use,vegetation coverage,and topographical factors influence water conservation *** found that precipitation is the main climatic factor in water *** water conservation function also varies with land-cover type,with forests having the highest capacity,followed by ***,topographical factors,including altitude and slope,also shape the spatial patterns of water conservation functions in QMNP.

关键词： Water conservation function Ecosystem services InVEST model Qilian Mountain National Park Northwest China

Identification of African swine fever virus MGF505-2R as a potent inhibitor of innate immunity in vitro

在线全文

学校读者我要写书评

暂无评论

Virologica Sinica 2023年第1期38卷 84-95页

作者： Huaguo Huang wen dang Zhengwang Shi Mingyang Ding Fan Xu Tao Li Tao Feng Haixue Zheng Shuqi Xiao College of Veterinary Medicine Northwest A&F UniversityYangling712100China State Key Laboratory of Veterinary Etiological Biology College of Veterinary MedicineLanzhou UniversityLanzhou Veterinary Research InstituteChinese Academy of Agricultural SciencesLanzhou730046China College of Veterinary Medicine Gansu Agricultural UniversityLanzhou730070China

African swine fever(ASF)is etiologically an acute,highly contagious and hemorrhagic disease caused by African swine fever virus(ASFV).Due to its genetic variation and phenotypic diversity,until now,no efficient commercial vaccines or therapeutic options are *** ASFV genome contains a conserved middle region and two flexible ends that code for five multigene families(MGFs),while the biological functions of the MGFs are not fully ***,ASFV MGF505-2R-deficient mutant ASFV-Δ2R was constructed based on a highly virulent genotype II field isolate ASFV CN/GS/2018 currently circulating in *** profiling demonstrated that ASFV-Δ2R was capable of inducing a larger number of differentially expressed genes(DEGs)compared with ASFV CN/GS/*** clustering of up-regulated DEGs revealed that ASFV-Δ2R induced the most dramatic expression of interferon-related genes and inflammatory and innate immune genes,as further validated by *** GO and KEGG pathway analysis identified significantly enriched pathways involved in pathogen recognition and innate antiviral ***,pharmacological activation of those antiviral immune responses by exogenous cytokines,including type I/II IFNs,TNF-αand IL-1β,exerted combinatory effects and synergized in antiviral capacity against ASFV ***,MGF505-2R is a newly identified inhibitor of innate immunity potentially implicated in immune evasion.

关键词： African swine fever virus(ASFV) Multigene families(MGFs) MGF505-2R Differentially expressed genes(DEGs)

Geochemical identification of a source rock affected by migrated hydrocarbons and its geological significance:Fengcheng Formation,southern Mahu Sag,Junggar Basin,NW China

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

Petroleum Science 2024年第1期21卷 100-114页

作者： wen-Long dang Gang Gao Xin-Cai You Ke-Ting Fan Jun Wu De-wen Lei wen-Jun He Yong Tang State Key Laboratory of Petroleum Resource and Prospecting China University of Petroleum(Beijing)Beijing102249China School of GeoSciences China University of Petroleum(Beijing)Beijing102249China Exploration&Development Institute Xinjiang Oil Field CompanyKaramay834000XinjiangChina

The Fengcheng Formation is a crucial source rock and the primary reservoir for oil accumulation in the Mahu *** oils are distributed throughout the Fengcheng Formation,ranging from the edge to the interior of the sag in the southern Mahu *** crude oils originate from in-situ source rocks in shallowly buried areas and the inner deep *** migration,the crude oil from the inner deep sag affects the source rocks close to carrier beds,leading to changes in the organic geochemical characteristics of the source *** changes might alter source rock evaluations and oil-source *** on data such as total organic carbon(TOC),Rock-Eval pyrolysis of source rocks,and gas chromatography-mass spectrometry(GC-MS)of the saturated fraction,and considering the geological characteristics of the study area,we define the identification characteristics of source rock affected by migrated hydrocarbons and establish the various patterns of influence that migrated hydrocarbons have on the source rock of the Fengcheng Formation in the southern Mahu *** source rocks of the Fengcheng Formation are mostly fair to good,containing mainly Type II organic matter and being thermally mature enough to generate *** rocks affected by migrated hydrocarbons exhibit relatively high hydrocarbon contents(S1/TOC>110 mg HC/g TOC,Extract/TOC>30%,HC:hydrocarbon),relatively low Rock-Eval Tmax values,and relatively high tricyclic terpane contents with a descending and mountain-shaped ***,biomarker composition parameters indicate a higher thermal maturity than in-situ source *** a comparison of the extract biomarker fingerprints of adjacent reservoirs and mudstones in different boreholes,three types of influence patterns of migrated hydrocarbons are identified:the edge-influence of thin sandstone-thick mudstone,the mixed-influence of sandstone-mudstone interbedded,and the full-influence of thick sandstone-thin *** finding reminds

关键词： Organic geochemistry Source rock Influence of migrated hydrocarbons Fengcheng Formation Southern Mahu Sag

Yixin Ningshen Tablet Alleviates Comorbidity of Myocardial Infarction and Depression by Enhancing Myocardial Energy Metabolism and Increasing Availability of Monoamine Neurotransmitter

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Integrative Medicine 2022年第7期28卷 586-593页

作者： JIANG Bing WU Ruo-ming LI Hai-dong LI Kun LI Hui dang wen-zhen FENG Gui-ze BAO Wei-lian YE Guan SHEN Xiao-yan Department of Pharmacology School of PharmacyFudan UniversityShanghai 200120China Department of Pharmacology of Chinese Materia Medica School of Traditional Chinese MedicineGuangdong Pharmaceutical UniversityGuangzhou 510006China Central Research Institute Shanghai Pharmaceuticals Holding Co.Ltd.Shanghai 200120China

Objective: To investigate the therapeutic effect of Yixin Ningshen Tablet(YXNS) on comorbidity of myocardial infarction(MI) and depression in rats and explore the underlying mechanism. Methods: The Sprague-Dawley rats were randomly divided into 5 groups with 7 rats in each group according to their weights,including control, model, fluoxetine(FLXT, 10 mg/kg), low-dose YXNS(LYXNS, 100 mg/kg), and high-dose YXNS(HYXNS, 300 mg/kg) groups. All rats were pretreated with corresponding drugs for 12 weeks. The rat model of MI and depression was constructed by ligation of left anterior descending coronary artery and chronic mild stress stimulation. The echocardiography, sucrose preference test, open field test, and forced swim test were performed. Myocardial infarction(MI) area and myocardial apoptosis was also detected. Serum levels of interleukin(IL)-6, IL-1β, tumor necrosis factor-α(TNF-α), 5-hydroxytryptamine(5-HT), adrenocorticotrophic hormone(ACTH), corticosterone(CORT), and norepinephrine(NE) were determined by enzyme linked immunosorbent assay. The proteins of adenosine 5’-monophosphate-activated protein kinase(AMPK), p-AMPK,peroxisome proliferator-activated receptor gamma coactivator-1α(PGC-1α), and nuclear respiratory factor 1(NRF1) in heart were detected by Western blot analysis. The expression levels of TNF-α, IL-6, indoleamine 2,3-dioxygenase(IDO1), kynurenine 3-monooxygenase(KMO), and kynureninase(KYNU) in hippocampus were detected by real-time quantitative polymerase chain reaction. Results: Compared with the model group,the cardiac function of rats treated with YXNS significantly improved(P<0.01). Meanwhile, YXNS effectively reduced MI size and cardiomyocytes apoptosis of rats(P<0.01 or P<0.05), promoted AMPK phosphorylation,and increased PGC-1α protein expression(P<0.01 or P<0.05). HYXNS significantly increased locomotor activity of rats, decreased the levels of TNF-α, IL-6 and IL-1β, and increased the serum levels of 5-HT, NE, ACTH,and CORT(all P<0.05). More

关键词： Yixin Ningshen Tablet depression cardiovascular disorders inflammatory factor monoamine neurotransmitter kynurenine pathway Chinese medicine

Studies on Fixed-depth Control of Supercavitating Vehicles

在线全文

学校读者我要写书评

暂无评论

自动化学报 2010年第3期36卷 421-426页

作者： LI Dai-Jin LUO Kai ZHANG Yu-wen dang Jian-Jun College of Marine Engineering Northwestern Polytechnical University Xi'an 710072 P. R. China

A supercavitating vehicle is a complex high-speed underwater body that is exposed to extreme operating conditions due to its speed. To successfully control the depth and attitude,it is necessary to study the motion characteristics of the vehicles on a vertical plane. This study investigates the motion model on the vertical plane and analyzes the dynamic characteristics of supercavitating vehicles. Then,a fixed-depth control method is developed. For validating the designed control-algorithm, related simulation and experiments have been carried out for the control system. Analytical results show that the proposed control system accomplishes precise depth control of the supercavitating vehicles, providing a necessary theoretical basis for further study of the dynamic control problem for underwater supercavitating vehicles

关键词：运动特性控制算法计算方法动态控制