期刊文献+
共找到3,689篇文章
< 1 2 185 >
每页显示 20 50 100
Significant improvement after sensory tricks and trunk strength training for Parkinson’s disease with antecollis and camptocormia:A case report
1
作者 Jia-Ren Wang Yue Hu 《World Journal of Clinical Cases》 SCIE 2024年第2期443-450,共8页
BACKGROUND Patients with Parkinson's disease(PD)exhibit symptoms such as antecollis(AC)and camptocormia(CC).The pathology of these two conditions is unclear.Additionally,standard treatment methods have not been es... BACKGROUND Patients with Parkinson's disease(PD)exhibit symptoms such as antecollis(AC)and camptocormia(CC).The pathology of these two conditions is unclear.Additionally,standard treatment methods have not been established.The article reports the case of a 65-year-old female patient with AC and CC who was treated with central and peripheral interventions to alleviate symptoms.CASE SUMMARY We present the case of a 65-year-old female PD patient with AC and CC.The course of the disease was 5 years.She was treated with rehabilitation strategies such as sensory tricks and trunk strength training.During the inpatient period,we compared and analyzed the patient's gait,rehabilitation assessment scale score,and angles of her abnormal trunk posture in the first week,the third week,and the fifth week.The patient's stride length increased,indicating that the patient's walking ability was improved.The Unified Parkinson's Disease Scale Part Three score and CC severity score decreased.Furthermore,the score of the other scale increased.In addition,the patient showed significant improvements in AC,upper CC,and lower CC angles.CONCLUSION This case study suggested that sensory tricks and trunk strength training are beneficial and safe for patients with AC and CC. 展开更多
关键词 Antecollis Camptocormia Parkinson's disease Sensory tricks trunk strength training Case report
下载PDF
Simultaneous Compression of the Celiac Trunk, Superior Mesenteric Artery, and Renal Arteries by the Median Arcuate Ligament: About One Case
2
作者 Siddick Oumar Kenza Fathallah +5 位作者 Hassan Ahmed Aicha Merzem Hasnaa Belgadir Omar Amriss Nadia Moussali Naima El Benna 《Open Journal of Medical Imaging》 2024年第3期106-113,共8页
Median arcuate ligament syndrome (MALS), is a rare abdominal vascular compression syndrome caused by the compression of the proximal celiac trunk by the median arcuate ligament. According to many authors, a low insert... Median arcuate ligament syndrome (MALS), is a rare abdominal vascular compression syndrome caused by the compression of the proximal celiac trunk by the median arcuate ligament. According to many authors, a low insertion of the diaphragmatic crura or an abnormally high origin of the celiac trunk from the aorta can cause compression of the celiac artery. Usually, patients with MALS are asymptomatic. Computed tomography (CT) angiography of the abdomen is the main imaging modality to confirm the diagnosis. The coexistence of celiac trunk and superior mesenteric artery compression by the median arcuate ligament is rarely described in the literature. To our knowledge, until now, a simultaneous combination of three abdominal vascular compressions by the median arcuate ligament has never been described. From this case, we report a simultaneous compression of the celiac trunk, superior mesenteric artery, and renal arteries by the median arcuate ligament. 展开更多
关键词 Median Arcuate Ligament Syndrome (MALS) Celiac trunk Compression Superior Mesenteric Artery and Renal Arteries Compression Computed Tomography Angiography
下载PDF
A tree detection method based on trunk point cloud section in dense plantation forest using drone Li DAR data 被引量:2
3
作者 Yupan Zhang Yiliu Tan +4 位作者 Yuichi Onda Asahi Hashimoto Takashi Gomi Chenwei Chiu Shodai Inokoshi 《Forest Ecosystems》 SCIE CSCD 2023年第1期37-45,共9页
Single-tree detection is one of the main research topics in quantifying the structural properties of forests. Drone Li DAR systems and terrestrial laser scanning systems produce high-density point clouds that offer gr... Single-tree detection is one of the main research topics in quantifying the structural properties of forests. Drone Li DAR systems and terrestrial laser scanning systems produce high-density point clouds that offer great promise for forest inventories in limited areas. However, most studies have focused on the upper canopy layer and neglected the lower forest structure. This paper describes an innovative tree detection method using drone Li DAR data from a new perspective of the under-canopy structure. This method relies on trunk point clouds, with undercanopy sections split into heights ranging from 1 to 7 m, which were processed and compared, to determine a suitable height threshold to detect trees. The method was tested in a dense cedar plantation forest in the Aichi Prefecture, Japan, which has a stem density of 1140 stems·ha^(-1) and an average tree age of 42 years. Dense point cloud data were generated from the drone Li DAR system and terrestrial laser scanning with an average point density of 5000 and 6500 points·m^(-2), respectively. Tree detection was achieved by drawing point-cloud section projections of tree trunks at different heights and calculating the center coordinates. The results show that this trunk-section-based method significantly reduces the difficulty of tree detection in dense plantation forests with high accuracy(F1-Score=0.9395). This method can be extended to different forest scenarios or conditions by changing section parameters. 展开更多
关键词 Tree detection trunk sections FOREST DRONE LiDAR
下载PDF
An Anatomical and Radiological Study of Origins of the Arteries Forming the Celiac Trunk: Clinical and Embryological Implications
4
作者 Fahrettin Fatih Kesmezacar Cem Kopuz +2 位作者 Onur Tutar Kubilay Kınoglu Erdoğan Kara 《Forensic Medicine and Anatomy Research》 2023年第2期15-29,共15页
The blood supply to the most of abdominal organs is provided by the branches of CT. The SMA supply caecum, ascends colon, all of the small bowels except the upper part of duodenum. Knowledge of variable anatomy of cel... The blood supply to the most of abdominal organs is provided by the branches of CT. The SMA supply caecum, ascends colon, all of the small bowels except the upper part of duodenum. Knowledge of variable anatomy of celiac axis and SMA may be useful in planning and executing radiological interventions such as celiacography and chemoembolization of hepatic and pancreatic tumors. In this study, the uncommon or low percentage cases of CT and SMA are presented in the light of clinical and embryological information. The celiac axises of a total of 30 adult corpses were examined. Dissections of abdominal region were performed in detail according to Cunningham’s manual. Angiographic images of 100 consecutive adult patients who underwent celiac MDCT angiography were evaluated. During autopsies, an incomplete celiac trunk or bifurcation of celiac trunk associated with the hepatomesenteric and gastrosplenic trunks (0.7%) and a celiacomesenteric trunk associated with high origin superior mesenteric artery and gastrosplenic trunk were detected (0.7%). During MDCT angiography, a case of total absence of celiac trunk associated with a hepatosplenomesenteric trunk (0.7%) and also a case of total absence of celiac trunk alone were observed (0.7%). The persistence or unusual development of ventral splanchnic arteries (VSAs) or ventral longitudinal anastomosis may result in variations or the unusual trunks related to celiac axis and SMA. The anomalous trunks of the CT may be result of either the persistence of some parts of the VSAs or ventral longitudinal anastomose that normally disappear or disappearance of parts that normally persist. The prevalence of unusual trunks of celiac axis and SMA in this study is quite low in literature. These abnormal vessels pose problems for surgeons and radiologists. Such vascular anomalies may cause clinical complications following surgical and radiological procedures such as resection of tumor of the pancreatic head, lymphadenectomy, coeliacography, aortic replacement with reimplantation of the trunk and coembolization of pancreatic and liver tumors. 展开更多
关键词 Celiac trunk Superior Mesenteric Artery Variation Hepatosplenomesenteric trunk Celiacomesenteric trunk EMBRYOLOGY
下载PDF
Trunk volume estimation of irregular shaped Populus euphratica riparian forest using TLS point cloud data and multivariate prediction models
5
作者 Asadilla Yusup Umut Halik +4 位作者 Maierdang Keyimu Tayierjiang Aishan Abdulla Abliz Babierjiang Dilixiati Jianxin Wei 《Forest Ecosystems》 SCIE CSCD 2023年第1期1-11,共11页
Background: Trunk volume(Vt) is an essential parameter for estimating forest stand volume, biomass, and carbon sequestration potential. As the dominant tree species in desert riparian forests, Euphrates poplar(Populus... Background: Trunk volume(Vt) is an essential parameter for estimating forest stand volume, biomass, and carbon sequestration potential. As the dominant tree species in desert riparian forests, Euphrates poplar(Populus euphratica) has a high proportion of irregularly shaped tree trunks along the Tarim River, NW China, where the habitat is very fragile owing to long-term water stress. This causes uncertainty in estimation accuracy as well as technical challenges for forest surveys. Our study aimed to acquire P. euphratica Vtusing terrestrial laser scanning(TLS) and to establish a species-specific Vtprediction model.Methods: A total of 240 individual trees were measured by TLS multiple-station in 12 sampling plots in three sections along the lower reaches of the Tarim River. Vtwas calculated by a definite integration method using trunk diameters(Di) at every 0.1-m tree height obtained from TLS, and all data were split randomly into two sets:70% of data were used to estimate the model parameter calibration, and the remaining 30% were used for model validation. Sixteen widely used candidate tree Vtestimation models were fitted to the TLS-measured Vtand tree structural parameter data, including tree height(H), diameter at breast height(DBH), and basal diameter(BD). All model performances were evaluated and compared by the statistical parameters of determination coefficient(R^(2)),root mean square error(RMSE), Bayesian information criterion(BIC), mean prediction error(ME), mean absolute error(MAE), and modeling efficiency(EF), and accordingly the best model was selected.Results: TLS point cloud reflection intensity(RI) has advantageous in the extraction of data from irregular tree trunk structures. The P. euphratica tree Vtvalues showed obvious differences at the same tree height(H). There was no significant correlation between Vtand H(R^(2)=0.11, P < 0.01), which reflected the irregularity of P. euphratica trunk shape in the study area. Among all the models, model(14): Vt=0.909DBH1.184H0.487BD0.836(R^(2)=0.97, RMSE=0.14) had the best prediction capability for irregularly shaped Vtwith the highest R^(2), BIC(-37.96), and EF(0.96), and produced a smaller ME(0.006) and MAE(1.177) compared to other models. The prediction accuracy was 93.18%.Conclusions: TLS point cloud RI has a potential for nondestructively measuring irregularly shaped trunk structures of P. euphratica and developed Vtprediction models. The multivariate models more effectively predicted Vtfor irregularly shaped trees compared to one-way and general volume models. 展开更多
关键词 Populus euphratica trunk volume Terrestrial laser scanning(TLS) Reflection intensity Tarim river
下载PDF
Possibilities of Assessing Respiratory Muscle Strength and Trunk Muscle Mass in the Prevention of Sarcopenia in Older People Living in the Community
6
作者 Yutaro Hyodo Takumi Jiroumaru +4 位作者 Kenji Mori Tomoka Hattori Yasumasa Oka Minoru Kuroda Takamitsu Fujikawa 《Open Journal of Therapy and Rehabilitation》 2023年第3期82-89,共8页
Objective: The purpose of this study was to clarify the relationship between respiratory muscle strength and skeletal muscle mass (trunk, upper limbs, and lower limbs) in older people who were certified as requiring n... Objective: The purpose of this study was to clarify the relationship between respiratory muscle strength and skeletal muscle mass (trunk, upper limbs, and lower limbs) in older people who were certified as requiring nursing or supportive care. Methods: Thirty-five older people (65 years or older) who were certified as requiring nursing care or support were included in the study. The subjects were divided into a non-sarcopenic group (n = 12) and a sarcopenic group (n = 23) according to the sarcopenia diagnostic criteria proposed by the Asian Working Group for Sarcopenia. Maximum inspiratory pressure, maximum expiratory pressure, skeletal muscle mass (trunk, upper and lower limbs), and hand grip strength were measured. Pearson’s correlation coefficient and multiple regression analysis were used for statistical processing. Results: In the non-sarcopenic group, both expiratory muscle strength and hand grip strength were correlated with skeletal muscle mass. In the sarcopenia group, expiratory muscle strength was not correlated with skeletal muscle mass, and only hand grip strength was correlated with upper limb muscle mass. Multiple regression analysis revealed that, in the non-sarcopenic group, trunk muscle mass was the primary factor in expiratory muscle strength and upper limb muscle mass was the primary factor in hand grip strength. In the sarcopenia group, upper limb muscle mass was found to be the main factor in hand grip strength. Conclusion: Our results highlight the importance of assessing expiratory muscle strength and trunk muscle mass before sarcopenia develops in older people who require support and nursing care. 展开更多
关键词 Respiratory Strength PIMAX PEMAX trunk Muscle Mass Skeletal Muscle Mass
下载PDF
Modeling Date Palm Trunk Fibers (DPTF) Packed Bed Adsorption Performances for Cadmium Removal from Aqueous Wastewater
7
作者 Ahmad S.Awad Banan Hudaib Waid Omar 《Fluid Dynamics & Materials Processing》 EI 2023年第6期1535-1549,共15页
In this study,the potential of a low-cost bio-adsorbent,taken directly from Date Palm Trunk Fibers(DPTF)agricultural wastes,for cadmium ions removal from wastewaters is examined.The performances of this adsorbent are ... In this study,the potential of a low-cost bio-adsorbent,taken directly from Date Palm Trunk Fibers(DPTF)agricultural wastes,for cadmium ions removal from wastewaters is examined.The performances of this adsorbent are evaluated by building breakthrough curves at different bed heights and flow rates while keeping other parameters,such as the initial feed concentration,pH,and particle size,constant.The results indicate that the maximum cadmium adsorption capacity of DTPF can be obtained from the Thomas model as 51.5 mg/g with the most extended mass transfer zone of 83 min at the lowest flow rate at 5 ml/min.The saturation concentrations(NO)and the rate constant(kab)obtained from the BDST(bed depth service time)model are 7022.16 mg/l and 0.0536 l/mg.min,respectively.Using the Yon-Nelsen Model,it is found that operating at a lower flow rate leads to a larger value of the elapsed needed time to reach a 50%breakthrough.The Wolborska model indicates that the bed capacity increases with decreasing the flow rate,and the adsorbent can achieve a greater external mass transfer kinetic coefficient(2.271/min)at a higher flow rate. 展开更多
关键词 Cadmium ions ADSORPTION fixed bed biodorbent POLLUTANT date palm trunk fibers wastewater treatment breakthrough curves MODELING
下载PDF
咯血患者甲状颈干异位支气管动脉解剖分析和栓塞治疗
8
作者 沈斌 侯忠衡 +1 位作者 李明国 许建伟 《介入放射学杂志》 CSCD 北大核心 2024年第4期371-375,共5页
目的分析咯血患者中起源于甲状颈干的异位支气管动脉解剖特点和栓塞治疗。方法回顾性分析2020年1月至2023年7月在湖州市中心医院接受支气管动脉栓塞术(BAE)治疗的连续565例咯血患者临床资料。所有患者BAE前均接受多层螺旋CT血管造影(MDC... 目的分析咯血患者中起源于甲状颈干的异位支气管动脉解剖特点和栓塞治疗。方法回顾性分析2020年1月至2023年7月在湖州市中心医院接受支气管动脉栓塞术(BAE)治疗的连续565例咯血患者临床资料。所有患者BAE前均接受多层螺旋CT血管造影(MDCTA)检查,其中519例BAE期间同时行锁骨下动脉及其分支DSA检查。对发现起源于甲状颈干支气管动脉的解剖、影像学表现及BAE情况进行初次描述。结果21例患者中有22支起源于甲状颈干的异位支气管动脉。根据开口位置及血管走行,22支甲状颈干异位支气管动脉中13支(59.1%)为Ⅰ型,4支(18.2%)为Ⅱ型,4支(18.2%)为Ⅲ型,1支(4.5%)为Ⅳ型。有5支(22.7%)异位支气管动脉与其他支气管动脉交通。所有异位支气管动脉均经BAE栓塞成功,术后均未发生严重并发症。结论MDCTA联合锁骨下动脉及其分支DSA可显示起源于甲状颈干异位支气管动脉的解剖学特征。超选择性BAE栓塞此类支气管动脉安全有效。 展开更多
关键词 咯血 支气管动脉 甲状颈干 血管内栓塞
下载PDF
精表处在公路预防性养护中的应用研究 被引量:1
9
作者 高彦芝 《科技创新与应用》 2024年第8期162-165,共4页
沥青路面长期暴露在自然条件下,受外界因素的影响,经常出现各种各样的病害,大部分病害都是逐渐形成的。因此,道路的预防性养护工作要得到足够重视,在病害早期阶段就加以控制。预防性养护就是在既有路面上加一个不超过4 cm的薄层,经过研... 沥青路面长期暴露在自然条件下,受外界因素的影响,经常出现各种各样的病害,大部分病害都是逐渐形成的。因此,道路的预防性养护工作要得到足够重视,在病害早期阶段就加以控制。预防性养护就是在既有路面上加一个不超过4 cm的薄层,经过研究精表处可以提高沥青路面的防水性能、抗滑性能,对路面的平整度和行车舒适性也会有明显改善。该文以某省道为例,经过路况调查评价,使用精表处对预防性养护路段进行处理,精表处施工前后,渗水系数、摩擦系数、构造深度均有明显改善。精表处施工无需加热,对于资源节约、环境保护方面可以起到积极的作用,同时还具有养护成本低、质保时间长等优点。 展开更多
关键词 精表处 普通国省干线 改性环氧沥青 预防性养护 路面结构
下载PDF
基于牛脸和躯干综合信息的奶牛个体识别研究
10
作者 赵玲 周桂红 任力生 《河北农业大学学报》 CAS CSCD 北大核心 2024年第2期112-118,共7页
针对基于单一信息对奶牛个体身份识别精度低的问题,本文提出1种基于牛脸和躯干综合信息对奶牛个体身份识别的方法。在Mask R-CNN目标检测模型的基础上进行改进,将注意力机制模块引入到Mask R-CNN的ResNet50特征提取网络的输出阶段,能够... 针对基于单一信息对奶牛个体身份识别精度低的问题,本文提出1种基于牛脸和躯干综合信息对奶牛个体身份识别的方法。在Mask R-CNN目标检测模型的基础上进行改进,将注意力机制模块引入到Mask R-CNN的ResNet50特征提取网络的输出阶段,能够在图像通道和空间上增强奶牛身份信息。针对奶牛不同部位,本文对改进前后的Mask R-CNN模型分别基于牛脸、基于躯干以及基于牛脸和躯干综合信息进行了相关实验。实验结果表明,原始Mask R-CNN模型基于牛脸和躯干综合信息进行奶牛个体识别,比单独基于牛脸或躯干的识别精度提高2.3%~3.7%。改进后的Mask R-CNN模型在自建奶牛图像数据集上的准确率达到了93.63%,mAP值达到92.16%,相较于原始Mask R-CNN,准确率提高了2.92%,mAP值提高了2.63%。本文方法能够实现对养殖场环境下奶牛个体身份的识别,可为奶牛的精准养殖提供技术支持。 展开更多
关键词 奶牛 牛脸和躯干 个体识别 Mask R-CNN 注意力机制
下载PDF
基于深度学习的森林移动机器人树干检测
11
作者 胡峻峰 朱昊 +2 位作者 黄晓文 李柏聪 赵亚凤 《森林工程》 北大核心 2024年第4期109-114,共6页
基于视觉导航的森林移动机器人具有机器人作为边缘设备算力有限、导航效果受光照影响较大的问题。为此,提出一种轻量化的树干检测方法,该方法基于YOLOv7-tiny模型,采用可见光图像与热成像图像作为输入,导航效果受光照影响较小;同时采用... 基于视觉导航的森林移动机器人具有机器人作为边缘设备算力有限、导航效果受光照影响较大的问题。为此,提出一种轻量化的树干检测方法,该方法基于YOLOv7-tiny模型,采用可见光图像与热成像图像作为输入,导航效果受光照影响较小;同时采用基于部分通道卷积(Partial Convolution,PConv)的特征提取模块-部分通道卷积高效层聚合网络(Partial Efficient Layer Aggregation Networks,P-ELAN),对基准模型进行轻量化改进;在训练阶段用alpha-CIoU损失函数替换原始的CIoU损失函数,提高边界框回归的准确性。结果表明,所提出的森林移动机器人树干检测方法相较于原始YOLOv7-tiny模型参数量减少31.7%,计算量减少33.3%,在图形处理器(Graphics Processing Unit,GPU)和中央处理器(Central Processing Unit,CPU)上的推理速度分别提升了33.3%和7.8%。修改后的模型在保持对树干检测精度基本不变的基础上更加轻量化,成为部署在机器人等边缘设备上的理想选择。 展开更多
关键词 树干检测 森林移动机器人 目标检测 热成像 轻量化
下载PDF
从同步数据分析乔木树干液流与气象因子的关系
12
作者 马泽 宋维峰 +1 位作者 徐小青 储娅 《林业科学研究》 CSCD 北大核心 2024年第2期165-177,共13页
[目的]树干液流是研究植物蒸腾耗水的重要生理指标,树种和气象因子均是其关键影响因素。本文旨在消除树种因素限制,探讨树干液流与气象因子之间的关系。[方法]以哈尼梯田水源区3种林分中10种乔木树种为研究对象,采用Granier热扩散探针... [目的]树干液流是研究植物蒸腾耗水的重要生理指标,树种和气象因子均是其关键影响因素。本文旨在消除树种因素限制,探讨树干液流与气象因子之间的关系。[方法]以哈尼梯田水源区3种林分中10种乔木树种为研究对象,采用Granier热扩散探针技术测定其树干液流速率,将其同步数据与气象因子进行关联分析。[结果]从次生落叶阔叶林和原生常绿阔叶林的7779条乔木树干液流速率数据中发现7条异常数据,且这些异常数据在各个树种中都表现出同步一致性;进一步关联分析表明,太阳辐射的突然增加是产生乔木树干液流数据同步上升的主要原因,而降雨则是产生树干液流数据同步下降的主要原因,两者的变化可导致其他气象因子发生变化,从而影响树干液流速率;树干液流与气象因子存在一定的时滞效应,在发生同步异常数据的气候条件下,树干液流滞后太阳辐射0~30 min,提前于饱和水汽压差、气温和湿度0~60 min,滞后或提前时间远小于正常气候条件下各树种的时滞时间。[结论]乔木树干液流受到太阳辐射和降雨等气象因子的综合调节,其中太阳辐射的影响最为显著。研究结果可为从生理生态角度探究乔木的蒸腾作用与气象因子的关系提供科学依据。 展开更多
关键词 树干液流 气象因子 关系分析 同步异常 时滞效应
下载PDF
基于SVM的干线输气管道泄漏压降速率信号识别
13
作者 吴瑕 陈红环 +2 位作者 贾文龙 孙溢彬 任思波 《中国安全科学学报》 CAS CSCD 北大核心 2024年第6期119-126,共8页
为解决压缩机抽吸或截断阀截断形成的压降信号导致截断阀发生误关断,以及小孔泄漏因管道压降不显著导致截断阀不动作的问题,以某输气干线为对象建立仿真模型,获取压缩机抽吸、截断阀紧急截断及管道泄漏3类不同工况下的300组压降信号,根... 为解决压缩机抽吸或截断阀截断形成的压降信号导致截断阀发生误关断,以及小孔泄漏因管道压降不显著导致截断阀不动作的问题,以某输气干线为对象建立仿真模型,获取压缩机抽吸、截断阀紧急截断及管道泄漏3类不同工况下的300组压降信号,根据对点检测法计算出压降信号的压降速率值;以奇异值分解(SVD)法和极差归一化方法提取压降速率信号特征,采用支持向量机(SVM)法识别不同压降速率特征值信号,获取所对应的工况类型;针对SVM模型中的核函数参数与惩罚因子设置不合理,影响算法识别准确性的问题,采用教与学优化算法(TLBO)优化核函数参数与惩罚因子,建立干线输气管道泄漏信号智能识别的TLBO-SVM模型;应用该模型,分类识别该管道在3类工况下的300组模拟压降速率信号。结果表明:该模型对3类不同工况下压降速率信号的识别准确率为92.22%;对泄漏口径为50~125 mm,压降速率范围为0.01~0.07 MPa/min的小孔泄漏,识别准确率为96.67%。针对某干线管道的实际泄漏压降速率信号,TLBO-SVM识别到的准确率为100%。 展开更多
关键词 支持向量机(SVM) 干线输气管道 压降速率信号 泄漏压力信号 截断阀
下载PDF
彩色多普勒超声在腹腔干与肠系膜上动脉共干畸形中的诊断价值
14
作者 闫庆 姚亚男 《四川解剖学杂志》 2024年第4期1-3,共3页
目的:探讨彩色多普勒超声在腹腔干与肠系膜上动脉共干畸形(celio-mesenteric trunk,CMT)中的诊断价值.方法:选取2009年1月至2024年6月于本院行超声检查的6例腹腔干与肠系膜上动脉共干畸形患者为研究对象,观察并分析彩色多普勒超声表现.... 目的:探讨彩色多普勒超声在腹腔干与肠系膜上动脉共干畸形(celio-mesenteric trunk,CMT)中的诊断价值.方法:选取2009年1月至2024年6月于本院行超声检查的6例腹腔干与肠系膜上动脉共干畸形患者为研究对象,观察并分析彩色多普勒超声表现.结果:6例CMT畸形中,2例为短干型,共同动脉干长均约3mm,超声表现为CMT从腹主动脉发出后立即分为腹腔干及肠系膜上动脉.长干型4例,共同动脉干长约15~20mm,共同动脉干从腹主动脉发出后,走行较长一段距离后分出腹腔干和肠系膜上动脉.结论:彩色多普勒超声对CMT具有重要的诊断价值. 展开更多
关键词 超声检查 彩色多普勒 腹腔干 肠系膜上动脉 共干
下载PDF
基于激光雷达与相机融合的树干检测方法 被引量:1
15
作者 刘洋 冀杰 +3 位作者 赵立军 冯伟 贺庆 王小康 《西南大学学报(自然科学版)》 CSCD 北大核心 2024年第2期183-196,共14页
针对传统传感器在树干检测中的局限性和单一性,提出一种基于激光雷达与相机融合的树干检测方法.首先,利用深度图对激光雷达点云进行处理,实现地面点云去除以及树干点云聚类,并在聚类中设置横、纵向自适应阈值,去除聚类中墙体、杂草、树... 针对传统传感器在树干检测中的局限性和单一性,提出一种基于激光雷达与相机融合的树干检测方法.首先,利用深度图对激光雷达点云进行处理,实现地面点云去除以及树干点云聚类,并在聚类中设置横、纵向自适应阈值,去除聚类中墙体、杂草、树叶等多余信息;然后,利用YOLOv3算法对相机图像进行分析,基于树干特征实现目标识别并返回检测框与类别信息;最后,基于交并比方法(IoU)对2种传感器的检测结果进行融合,识别树干并返回其三维信息与位置信息.以无人割草机为载体开展场地测试,实验结果表明:融合算法的树干检测准确率在93.1%左右,树干定位横、纵向平均误差分别为0.075 m和0.078 m,能够满足无人割草机的树干检测要求,为智能农机的环境感知提供了一种新的方法. 展开更多
关键词 树干检测 激光雷达 相机 深度图 传感器融合
下载PDF
面向Trunk技术的网络拓扑发现算法研究 被引量:5
16
作者 李丹程 马东琳 +1 位作者 韩春燕 刘益先 《小型微型计算机系统》 CSCD 北大核心 2012年第11期2435-2441,共7页
随着企业组网模式的大型化、复杂化及VLAN技术在交换层网络中的广泛应用,当前交换层拓扑发现算法在拓扑发现效率及普适性上存在诸多问题,本文分析Trunk技术特点,提出一种结合地址转发表与Trunk信息的网络拓扑发现算法,该算法提高了网络... 随着企业组网模式的大型化、复杂化及VLAN技术在交换层网络中的广泛应用,当前交换层拓扑发现算法在拓扑发现效率及普适性上存在诸多问题,本文分析Trunk技术特点,提出一种结合地址转发表与Trunk信息的网络拓扑发现算法,该算法提高了网络拓扑发现算法运行效率及发现结果准确性,此外,算法对多厂商数据进行分析使其对当前主流的多VLAN交换网络拓扑有着更强的适应性并能够准确给出网络逻辑拓扑连接关系,同时,给出了算法的实现方法及园区网测试的结果. 展开更多
关键词 trunk 二层网络拓扑发现 地址转发表 计算机网络 VLAN
下载PDF
应用地基激光雷达三维点云数据构建长白落叶松树干削度方程 被引量:2
17
作者 种雨丝 何培 +1 位作者 张兹鹏 姜立春 《东北林业大学学报》 CAS CSCD 北大核心 2024年第3期69-75,共7页
使用地基激光雷达(TLS)三维点云数据提取的落叶松干形数据,构建树干削度方程,为落叶松干形精准预测提供依据。以吉林省一面山林场和杨木林林场落叶松人工林为研究对象,获取71株落叶松点云信息,并提取树干干形数据。选择简单、可变指数... 使用地基激光雷达(TLS)三维点云数据提取的落叶松干形数据,构建树干削度方程,为落叶松干形精准预测提供依据。以吉林省一面山林场和杨木林林场落叶松人工林为研究对象,获取71株落叶松点云信息,并提取树干干形数据。选择简单、可变指数、三角函数和分段函数等9个基础削度方程进行比较,利用分位数回归和广义加性模型方法构建削度方程。结果表明:在9个基础削度方程中,Bi(2000)削度方程的拟合效果最好,多重共线性指标条件数也小于100;Bi(2000)基础削度方程构建的分位数回归模型,在9个分位点(τ=0.1、0.2、0.3、0.4、0.5、0.6、0.7、0.8、0.9)处均能收敛,其中在τ=0.5的分位点处的拟合效果最好,略优于非线性回归的拟合结果。在以相对直径为因变量,以相对高的平方根、胸径的平方和树高为自变量的广义加性削度方程中,6种光滑样条函数(三次回归样条函数(CR)、B-样条函数(BS)、薄板回归样条函数(TP)、P-样条函数(PS)、Duchon样条函数(DS)和高斯过程平滑样条函数(GP))的拟合效果相差不大,但广义加性削度方程使用(DS+CR)光滑样条函数比一种光滑样条函数的拟合效果好(相对误差4.407、均方根误差1.158、确定系数0.966),广义加性削度方程的各检验统计量均优于基础削度方程和分位数回归削度方程,且在树干相对高度10%~80%,广义加性削度方程也表现最优(相对误差4.534、均方根误差1.191、确定系数0.964)。因此,(DS+CR)组合光滑样条函数的广义加性削度方程预测精度最高,可用于该区域的落叶松干形预测。 展开更多
关键词 长白落叶松 树干削度 分位数回归 广义加性模型 留一交叉验证
下载PDF
Trunk和VLAN技术在大型校园网中的综合运用 被引量:12
18
作者 黄世权 《安徽大学学报(自然科学版)》 CAS 北大核心 2006年第2期30-32,共3页
Trunk和V lan不仅可以提高网络运行的性能和效率,而且有利于网络安全、管理、升级和扩容,解决许多其他问题[1].根据多校区校园网建设和管理中的应用需求,充分发挥三层交换机的性能,采用Trunk和VLAN技术实施多校区网络建设的解决方案.并... Trunk和V lan不仅可以提高网络运行的性能和效率,而且有利于网络安全、管理、升级和扩容,解决许多其他问题[1].根据多校区校园网建设和管理中的应用需求,充分发挥三层交换机的性能,采用Trunk和VLAN技术实施多校区网络建设的解决方案.并通过网络建设实例介绍Trunk和VLAN技术在校园网管理中的构建、应用和配置策略. 展开更多
关键词 多校区 校园网 trunk VLAN 运用
下载PDF
八达岭林场黄栌枯萎病防效研究 被引量:1
19
作者 郭瑞峰 沈冲 +5 位作者 李必萌 杜辰明 李奇岩 王奥 崔轻舟 王永林 《北京林业大学学报》 CAS CSCD 北大核心 2024年第1期1-9,共9页
【目的】研究不同药剂组合和施药技术对八达岭林场黄栌枯萎病林间控制效果,探讨黄栌枯萎病有效防控措施,旨在保障北京地区黄栌健康和红叶景观安全。【方法】选择枯草芽孢杆菌、50%嘧菌酯、156 g/L丙环唑、50%多菌灵和45%咪鲜胺等5种药剂... 【目的】研究不同药剂组合和施药技术对八达岭林场黄栌枯萎病林间控制效果,探讨黄栌枯萎病有效防控措施,旨在保障北京地区黄栌健康和红叶景观安全。【方法】选择枯草芽孢杆菌、50%嘧菌酯、156 g/L丙环唑、50%多菌灵和45%咪鲜胺等5种药剂,采用灌根、树干注射和两者相结合的施药方式,共设置12个处理,对八达岭林场黄栌枯萎病开展林间防治试验。【结果】通过比较各处理在2021—2022年间黄栌枯萎病病情指数,得出当年防治效果最好的施药组合是灌根丙环唑结合树干注射多菌灵与嘧菌酯复配,校正病情指数为5,防治效果达到88%。并且,该组合中有26.67%植株保持健康,健康植株数量最多。第2年5月病情指数最低的施药组合是灌根枯草芽孢杆菌结合树干注射多菌灵与嘧菌酯复配,表现出较好的治疗效果,健康植株数量最多,且往年重度发病样树均转为无病或轻度发病,病情指数仅有3.33。其他施药方式和药剂组合均在不同程度上缓解黄栌枯萎病的发生,但是不同处理的防治效果统计学上存在显著差异(P <0.05)。【结论】本研究结果表明灌根丙环唑和树干注射多菌灵与嘧菌酯复配组合防治效果最佳,灌根枯草芽孢杆菌结合树干注射多菌灵与嘧菌酯复配组合在感病治疗及防治效果方面均表现良好,两者均可作为黄栌枯萎病的防治方案。 展开更多
关键词 灌根 树干注射 化学防治 黄栌枯萎病
下载PDF
华南地区国人成人腹腔干分型变异的临床应用研究
20
作者 赖文华 毛隆昆 +5 位作者 王诗雨 李奕宣 刘瑞平 徐达政 李明哲 周丽华 《中国临床解剖学杂志》 CSCD 北大核心 2024年第3期259-264,共6页
目的研究成人腹腔干的分型及其解剖变异特点,为临床手术提供参考依据。方法对44具经防腐处理的尸体进行了腹腔干解剖。观察腹腔干各分支的走形,根据Panagouli分型法以及其起源椎体水平对其进行进一步量化和描述。结果成人腹腔干标本存在... 目的研究成人腹腔干的分型及其解剖变异特点,为临床手术提供参考依据。方法对44具经防腐处理的尸体进行了腹腔干解剖。观察腹腔干各分支的走形,根据Panagouli分型法以及其起源椎体水平对其进行进一步量化和描述。结果成人腹腔干标本存在5种分型:83%(36例)拥有典型的腹腔干解剖结构(分型Ⅰ),18%(8例)有解剖变异,其中11%(5例)为分型Ⅲ,2%(1例)为分型Ⅳ,2%(1例)为分型Ⅴ,2%(1例)为分型Ⅸ。结论成人腹腔干变异较多,术前需结合影像学做好充分评估,避免损伤。 展开更多
关键词 腹腔干 腹腔血管 解剖研究
下载PDF
上一页 1 2 185 下一页 到第
使用帮助 返回顶部