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Seropositivity and Other Determinants Associated with Toxoplasmosis in Local Buffalo in Iraq
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作者 Rafid Jawad Kazem Imad Kazem Ali 《Open Journal of Veterinary Medicine》 CAS 2024年第1期1-9,共9页
A cross-sectional study was conducted to determine the Seropositivity of Toxoplasma gondii in water buffalo in three Iraqi governorates (Baghdad, Dhi Qar, and Maysan) and to estimate the risk aspects related to infest... A cross-sectional study was conducted to determine the Seropositivity of Toxoplasma gondii in water buffalo in three Iraqi governorates (Baghdad, Dhi Qar, and Maysan) and to estimate the risk aspects related to infestation throughout the period from January to December 2019. A total of 430 serum samples were inspected with a commercial ELISA (Enzyme linked immunosorbent assay) kit. Indirect multi-species kit. The overall Seropositivity of T. gondii in the examined local buffalo was 7.4%, and the highest rate (9.3%) was in Baghdad Governorate. A multivariate regression analysis revealed that adult buffalo (OR = 7.10;95% CI: 0.87-57.68;P = 0.067) and young herds (OR = 8.42;95% CI: 1.07-66.02;P = 0.043) were more subject to infestation from young buffalo and large herds. Furthermore, the hazard of toxoplasmosis was increased in winter especially among animals in contact with cats. It is therefore requisite to determine risk aspects to evaluate which mitigation, control, prevention and procedures should be carried out to diminish, control and prevent infestation with T. gondii and its propagation. 展开更多
关键词 TOXOPLASMOSIS BUFFALO local SEROPOSITIVITY Iraq
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Atlantic blocking events in a simplified nonlinear baroclinic model for local finite-amplitude wave activity
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作者 Ning Shi Bamidele Abiodun Paul Wencai Liu 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第4期41-45,共5页
为研究北大西洋阻高的形成机制,本文在局部有限振幅波活动(LWA)框架下进行了一系列数值实验.采用的数值模型能显式地描绘出两种重要的大气内部动力过程,即非线性纬向位涡通量和Rossby波包传播.模拟结果显示,这两种动力学过程均是形成大... 为研究北大西洋阻高的形成机制,本文在局部有限振幅波活动(LWA)框架下进行了一系列数值实验.采用的数值模型能显式地描绘出两种重要的大气内部动力过程,即非线性纬向位涡通量和Rossby波包传播.模拟结果显示,这两种动力学过程均是形成大西洋阻高的重要机理.具体地,非线性纬向位涡通量和Rossby波包传播,分别是大西洋阻高南部和北部LWA形成的主导因子.因此,本研究综合了前人关于大西洋阻高的研究成果,为其形成机理提供了新的认识. 展开更多
关键词 斜压模式 局地有限振幅波活动 罗斯贝波传播 非线性效应
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Real-World Evidence in Localized Pancreatic: Coping with Uncertainty in Unselected Populations
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作者 María I. Pamies Ramón Diana Ibarra Anguita +8 位作者 Paula Rodríguez Payá Alvaro Muñoz Abad David Sánchez García María Valero Revert Beatriz Grau Mirete Mariano Martínez Marín Alicia Calero Amaro Lorena Rodríguez Cazalla Javier Gallego Plazas 《Journal of Cancer Therapy》 2024年第4期164-178,共15页
Background: Localized pancreatic cancer, including resectable (R), borderline resectable (BR) and locally advanced unresectable disease (LAU), is considered in clinical guidelines for diverse treatment options based o... Background: Localized pancreatic cancer, including resectable (R), borderline resectable (BR) and locally advanced unresectable disease (LAU), is considered in clinical guidelines for diverse treatment options based on clinical trials in selected populations. Hence, exploring with real world evidence (RWE) clinicians’ preferences for treatment options and their results seems pertinent. Methods: In a set of consecutive patients with localized pancreatic cancer assisted in a third level hospital from January 2013 to December 2022, medical records, symptoms, diagnostic process, distribution between subtypes, and treatment plans, with safety and efficacy results, were assessed. Results: A total of 152 patients with localized disease were included (43.4% R, 21.0% BR, 33.6% LAU). The population characteristics exemplified differences between daily practice and clinical trials. Tumor location and symptoms were as expected. Treatment plan was conditioned by PS or comorbidities in 23.0% of patients. In patients with R disease, surgery followed by different adjuvant chemotherapy (CT) regimes was the antineoplastic treatment of choice (64.8%) with efficacy results (OS 37.5 months;95% CI 18.4 - 56.7), in the range of contemporary standards. The common use of neoadjuvant CT for BR disease (94.4%), with surgery in 50% of them, and its results (OS 30.8 months;95% CI 10.5 - 51.2) reflected current controversies of treatment recommendations and evolution in this scenario. Paliative CT with or without radiotherapy was the standard specific treatment in LAU disease (95.1%) with survival results (PFS: 10.8 months;95% CI 8.8 - 12.7. OS: 20.3 months;95% CI 13.5 - 27.2) that justify the distinct character and the specific study of this entity. Conclusion: RWE for localized pancreatic cancer aroused from the analysis of this population confirms the distinct nature of patients assisted in daily practice, as well as mirrors the complexity of decision making in clinical assumptions in which achieving stronger evidence should be paramount. 展开更多
关键词 Real-World Evidence localIZED PANCREATIC CANCER
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Modeling the Spatio-Temporal Dynamics of Local Context for a Contextualized Diffusion of Agroecological Intensification Options in Niger
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作者 Nouhou Salifou Jangorzo Maud Loireau +3 位作者 Abou-Soufianou Sadda Ousmane Sami Mari Abdoul-Aziz Saïdou Hassane Bil-Assanou Issoufou 《International Journal of Geosciences》 CAS 2024年第3期270-301,共32页
Spatio-temporal variability and dynamics in Sahelian agro-pastoral zones make each local situation a special case. These specificities must be considered to guide the dissemination of agricultural options with a view ... Spatio-temporal variability and dynamics in Sahelian agro-pastoral zones make each local situation a special case. These specificities must be considered to guide the dissemination of agricultural options with a view to sustainable development. The territorial scale of municipalities is not sufficient for this necessary contextualization;the scale of the “village terroir” seems to be a better option. This is the hypothesis we put forward in the framework of the Global Collaboration for Resilient Food Systems program (CRFS), i.e. local context is spatially defined by village terroir. The study is based on data collected through participatory mapping and surveys in “village terroirs” in three regions of Niger (Maradi, Dosso and Tillabéri). Then the links between farm managers and their cultivated land, as well as the spatio-temporal dynamics of local context are analyzed. This study provides evidence of the existence and functional usefulness of the village terroir for farmers, their land management and their activities. It demonstrates the usefulness of contextualizing agricultural options at this scale. Their analysis elucidates the links between “terroirs village” and the specific functioning of the agrosocio-ecosystems acting on each of them, thus laying the systemic and geographical foundations for a model of the spatio- temporal dynamics of “village terroirs”. This initial work has opened up new perspectives in modeling and sustainable development. 展开更多
关键词 NIGER Option by Context local Condition Complex System Multiscale Conceptual Modeling
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Fruit Powder of Tetrapleura tetraptera in Local Feed on Some Zootechnical Performances of Juveniles of Clarias gariepinus in Concrete Tank
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作者 Ngouana Tadjong Ruben Abdoulaye Abdoulaye +1 位作者 Kana Jean Raphaël Téguia Alexis 《Open Journal of Animal Sciences》 2024年第2期56-69,共14页
This study focused on the supplementation of four-sided spice fruit powder (Tetrapleura tetraptera) on some zootechnical performances of juveniles of Clarias gariepinus and was carried out from February 14 to July 20 ... This study focused on the supplementation of four-sided spice fruit powder (Tetrapleura tetraptera) on some zootechnical performances of juveniles of Clarias gariepinus and was carried out from February 14 to July 20 at the Massoma Fish Farm of Bojongo Mbeidi located in the Littoral Region, Department of Wouri, Douala IV district. The farm benefits from a climate favorable to aquaculture activity. For this purpose, five (5) treatments were tested including T<sub>0+</sub> (imported feed), T<sub>0-</sub>, T<sub>0.3</sub>, T<sub>0.4</sub>, and T<sub>0.5</sub> respectively for the treatments with 0% supplemented food;0.3%;0.4% and 0.5% of Tetrapleura tetraptera powder. A total of 450 Clarias gariepinus fry with an initial average weight of 7 ± 1.5 g, were distributed in happas of 0.49 m<sup>2</sup> each placed in Triplicate in a completely randomized device. Four isoprotein foods with 38% crude protein were formulated to feed these fry at 7% of their biomass per day for 15 days then to their fullness until the end of the experiment. Intermediate fishing was carried out every fortnight. 75 days later, the results recorded show that the highest average survival rate (96.44% ± 3.5%) was recorded with the subjects fed feed supplemented with 0.4% T. tetraptera powder. The average weight (120.93 ± 67.20), weight gain (113.93 ± 67.20), specific growth rate (3.64 ± 0.79% g/d) and total lengths and standard (26.43 ± 1.9 and 23.66 ± 1.76) the highest were recorded with the T<sub>0+</sub> treatment (imported feed). The highest conditioning factor K (2.14 ± 0.15) was recorded with the treatment supplemented with 0.4% T. tetraptera. The lowest conversion ratio (1.28) was recorded with the treatment fed with imported blue crown food (T<sub>0+</sub>). Furthermore, the lowest production cost was recorded with the treatment supplemented with 0.4% T. tetraptera. It appears from this study that the juveniles of C. gariepinus better value the feed substituted with 0.4% of the powder of four sides (Tetrapleura tetraptera). 展开更多
关键词 Tetrapleura tetraptera local Feed Zootechnical Performance Juvenile of Clarias gariepinus
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Management of Square Carcinoma of the Lower Lip Using Camille-Bernard Flap under Local Anesthesia: When Constraints Dictate Our Attitude
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作者 Silly Toure Mouhamadou Makhtar Ndiaye +3 位作者 Abibou Ndiaye Mame Sanou Diouf Birame Loum Baye Karim Diallo 《Open Journal of Stomatology》 2024年第4期191-197,共7页
Introduction: Squamous cell carcinomas of the lip essentially pose a therapeutic management problem. In the West, their treatment is done under general anesthesia and follows the classic rules of oncology. In our cont... Introduction: Squamous cell carcinomas of the lip essentially pose a therapeutic management problem. In the West, their treatment is done under general anesthesia and follows the classic rules of oncology. In our context of exercise, we sometimes have a different attitude dictated by various constraints. Observation: 55-year-old patient with no notable history, seen in consultation for a very large ulcerative-budding lesion on the right 2/3 of the lower lip with mucocutaneous involvement without lymph node findings found on examination. Faced with this suspicious lesion and the patient’s financial difficulties, we decided to operate under local anesthesia to remove this tumor. The oncological excision was followed by immediate plasty using a Camille-Bernard flap with a good immediate aesthetic and functional result and postoperative day 7. The patient was unable to take his surgical specimen to anatomy-pathology and was lost to follow-up due to lack of financial resources. On anatomo-pathological analysis of the surgical specimen, the margins were healthy with confirmation of squamous cell carcinoma (anapathological reading made for scientific interest). Discussion: The particular mentality of certain patients and their difficult financial conditions push us to have an unconventional therapeutic attitude in oncology, but which nevertheless makes it possible to resolve certain problems that we often face. Local anesthesia is possible and realistic in cases like ours and the results can be acceptable and life-saving. 展开更多
关键词 Squamous Cell Carcinoma Lower Lip Camille Bernard Flap local Anesthesia
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Local dimming原理及在车载中的应用
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作者 周琨 《时代汽车》 2024年第5期168-170,共3页
Local dimming(局部调光)是一种低成本提升车载显示器对比度和清晰度的技术。在目前OLED技术尚无法突破严苛的汽车环境要求的状况下,局部调光是一种首选的成本和性能兼顾的技术。在满足汽车环境要求的同时,大幅提升了显示器的清晰度,提... Local dimming(局部调光)是一种低成本提升车载显示器对比度和清晰度的技术。在目前OLED技术尚无法突破严苛的汽车环境要求的状况下,局部调光是一种首选的成本和性能兼顾的技术。在满足汽车环境要求的同时,大幅提升了显示器的清晰度,提高了显示内容的辨识度,同时成本的上升也在合理范围内。它能给客户带来更好的体验,使驾驶更为安全。本文对它的工作原理以及如何应用进行了阐述,给读者提供了一种思路和方法来提升车载显示器的对比度。 展开更多
关键词 local dimming原理 local dimming应用 车载显示器
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Fresnel Equations Derived Using a Non-Local Hidden-Variable Particle Theory
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作者 Dirk J. Pons 《Journal of Modern Physics》 2024年第6期950-984,共35页
Problem: The Fresnel equations describe the proportions of reflected and transmitted light from a surface, and are conventionally derived from wave theory continuum mechanics. Particle-based derivations of the Fresnel... Problem: The Fresnel equations describe the proportions of reflected and transmitted light from a surface, and are conventionally derived from wave theory continuum mechanics. Particle-based derivations of the Fresnel equations appear not to exist. Approach: The objective of this work was to derive the basic optical laws from first principles from a particle basis. The particle model used was the Cordus theory, a type of non-local hidden-variable (NLHV) theory that predicts specific substructures to the photon and other particles. Findings: The theory explains the origin of the orthogonal electrostatic and magnetic fields, and re-derives the refraction and reflection laws including Snell’s law and critical angle, and the Fresnel equations for s and p-polarisation. These formulations are identical to those produced by electromagnetic wave theory. Contribution: The work provides a comprehensive derivation and physical explanation of the basic optical laws, which appears not to have previously been shown from a particle basis. Implications: The primary implications are for suggesting routes for the theoretical advancement of fundamental physics. The Cordus NLHV particle theory explains optical phenomena, yet it also explains other physical phenomena including some otherwise only accessible through quantum mechanics (such as the electron spin g-factor) and general relativity (including the Lorentz and relativistic Doppler). It also provides solutions for phenomena of unknown causation, such as asymmetrical baryogenesis, unification of the interactions, and reasons for nuclide stability/instability. Consequently, the implication is that NLHV theories have the potential to represent a deeper physics that may underpin and unify quantum mechanics, general relativity, and wave theory. 展开更多
关键词 Wave-Particle Duality Optical Law Fresnel Equation Non-local Hidden-Variable
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Principles for Designing New Types of Housing for a Strong and Resilient Local Economy in the Republic of Congo
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作者 Alain Symphorien Ndongo Destin Gemetone Etou Christian Tathy 《Open Journal of Civil Engineering》 2024年第1期82-95,共14页
The Congolese population is organised into households, which are thus headed by a chief who ensures the social well-being, development and integration into working life of the individuals in his charge. This study exa... The Congolese population is organised into households, which are thus headed by a chief who ensures the social well-being, development and integration into working life of the individuals in his charge. This study examines the functional principles of new housing design as an instrument for transforming the (current) failing economy into a strong and resilient one. Accordingly, a literature review of the practice of designing and building housing in human settlements in the Congo revealed the state of the art on this subject. An analysis of the existing housing stock from a demographic, social and economic point of view made it possible to identify the most common household sizes and numbers, as well as the lifestyle processes that determine the need for developed space. To this end, the experimental method was used to propose configuration plans for various new types of dwelling. To this end, the study highlighted the link between people’s standard of living and the effectiveness of their involvement in the local economy. To achieve the aims of the National Development Plan (NDP), particular attention must be paid to solving the housing problem. The existing housing stock actively contributes to the problems associated with unemployment and insecurity. Functional principles for the design of new types of housing have been developed. Four model types are proposed in line with the demographic structure of the population, their socio-economic characteristics and their lifestyle. 展开更多
关键词 Congolese Households New Types of Lodging Human Settlements Resilient local Economy Households Resilient Endogenous Economy Logement CONCEPTION
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仿紧正则locale的紧正则反射
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作者 任春蕾 孙向荣 《江苏师范大学学报(自然科学版)》 CAS 2023年第2期43-46,共4页
在locale范畴中讨论仿紧locale的性质,证明仿紧正则locale是正规的.通过正规locale的插入性,给出正则理想格CR(L)是仿紧正则locale的紧正则反射的构造性描述.
关键词 仿紧正则locale 紧正则反射 正规locale
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Current Status and Research Progress of Neoadjuvant Chemotherapy for Locally Advanced Gastric Cancer 被引量:1
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作者 Junjian Liu Tian Wei +1 位作者 Zhiping Xiang Yinlu Ding 《Journal of Biosciences and Medicines》 CAS 2023年第3期156-170,共15页
Gastric cancer is one of the most common malignant tumours worldwide, with a high degree of malignancy and a poor prognosis. While early gastric cancer can be cured by surgical treatment, locally advanced gastric canc... Gastric cancer is one of the most common malignant tumours worldwide, with a high degree of malignancy and a poor prognosis. While early gastric cancer can be cured by surgical treatment, locally advanced gastric cancer requires neoadjuvant therapy to shrink the tumour, suppress potential metastases, achieve down-staging, and provide patients with the opportunity for radical surgery to prolong their survival. This article reviews the current status and progress of neoadjuvant chemotherapy for locally advanced gastric cancer. 展开更多
关键词 locally Advanced Gastric Cancer Adjuvant Chemotherapy Neoadjuvant Chemotherapy
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基于Local-BGM法的冷涡暴雨集合预报试验及评估检验
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作者 张海鹏 智协飞 +3 位作者 李昊 黎振宇 张志强 黄晶 《气象科学》 北大核心 2023年第1期36-45,共10页
基于传统增长模繁殖法(Breeding Growing Mode,BGM)和局地增长模繁殖法(Local Breeding Growing Mode,Local-BGM)生成初始扰动成员,对一次冷涡暴雨过程进行集合预报试验,从多方面比较两种方案的预报效果,并且在邻域概率法(Neighborhood ... 基于传统增长模繁殖法(Breeding Growing Mode,BGM)和局地增长模繁殖法(Local Breeding Growing Mode,Local-BGM)生成初始扰动成员,对一次冷涡暴雨过程进行集合预报试验,从多方面比较两种方案的预报效果,并且在邻域概率法(Neighborhood Probability,NP)中引入时间邻域,评估概率预报结果。结果表明,引入局地化思想的Local-BGM方案能够生成比传统BGM方案更合理的初始扰动,具有很明显的局地特征。对于扰动变量的预报,Local-BGM方案在均方根误差和离散度等方面均表现更好,同时能够提高各量级降水的预报技巧。邻域集合概率法能够综合各个集合成员预报的降水信息得到优于集合平均的概率预报,分数技巧评分更高。并且在考虑时间不确定性后,无论是控制预报、集合平均还是邻域集合概率法,分数技巧评分均有很大改善,并且降水阈值越大改善效果越明显,能够为极端强降水天气提供较为客观的概率预报信息。 展开更多
关键词 集合预报 局地增长模繁殖法 降水预报 邻域概率法 分数技巧评分
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基于LIO-SAM建图和激光视觉融合定位的温室自主行走系统 被引量:2
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作者 孙国祥 黄银锋 +2 位作者 汪小旵 袁云鹏 陈光宇 《农业工程学报》 EI CAS CSCD 北大核心 2024年第3期227-239,共13页
为解决传统导航方案在温室内无法应对光照变化大、作物行间距窄、接收GPS信号差等问题,该研究提出了基于即时定位与地图构建技术的激光视觉融合式自主导航算法。该系统利用三维激光雷达VLP-16(Velodyne LiDAR,VLP-16)和惯性测量单元获... 为解决传统导航方案在温室内无法应对光照变化大、作物行间距窄、接收GPS信号差等问题,该研究提出了基于即时定位与地图构建技术的激光视觉融合式自主导航算法。该系统利用三维激光雷达VLP-16(Velodyne LiDAR,VLP-16)和惯性测量单元获取温室环境信息,采用基于紧耦合的雷达惯导定位建图(tightly-coupled lidar inertial odometry via smoothing and mapping,LIO-SAM)算法构建导航地图,基于轮式里程计和视觉里程计采用扩展卡尔曼滤波器算法实现局部定位,融合激光点云配准算法和自适应蒙特卡洛定位算法实现全局定位。同时,在自主行走系统应用A*算法规划全局路径和动态窗口算法规划局部路径,从而实现自主导航。试验结果表明,LIO-SAM算法构建的温室导航地图最大相对误差、最大绝对误差和均方根误差分别为9.9%、0.081和0.063 m,在温室内改进后的定位算法横向偏差小于0.020 m,纵向偏差小于0.090 m;当自主行走系统以0.15、0.30和0.50 m/s的速度运行时,横向偏差、纵向偏差和航向偏角的平均值分别小于0.120 m、0.10 m和8.5°,标准差分别小于0.070 m、0.140 m和6.6°。该导航方案满足自主行走系统在温室内高精度建图、定位和导航的需求,可为自主移动平台提供理论与技术支撑。 展开更多
关键词 温室 自主导航 视觉里程计 即时定位与地图构建 自适应蒙特卡洛定位 卡尔曼滤波
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局部锈蚀圆钢管混凝土短柱轴压承载力试验研究 被引量:2
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作者 陈梦成 罗苏昌 +3 位作者 黄宏 方苇 许开成 钱文磊 《中南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第1期317-329,共13页
钢管混凝土(CFST)在服役环境中被腐蚀,导致其钢结构承载力降低,严重威胁到结构的服役性能和使用寿命。首先,采用机加工车铣方法制作模拟局部锈蚀的人工缺陷,然后以钢管外表面局部环向贯通锈蚀位置、锈蚀钢管体积损失率、锈蚀外表面面积... 钢管混凝土(CFST)在服役环境中被腐蚀,导致其钢结构承载力降低,严重威胁到结构的服役性能和使用寿命。首先,采用机加工车铣方法制作模拟局部锈蚀的人工缺陷,然后以钢管外表面局部环向贯通锈蚀位置、锈蚀钢管体积损失率、锈蚀外表面面积损失率(简称锈蚀面积损失率,下同)为试验参数,对45根局部锈蚀圆CFST短柱试件进行轴压承载力试验;其次,分析锈蚀位置、锈蚀钢管体积损失率、面积损失率和壁厚损失率对锈蚀试件承载力、刚度和延性的影响,揭示锈蚀CFST试件破坏机理和承载力退化机制;最后,针对局部锈蚀圆CFST短柱构件轴压承载力提出一个简化实用计算公式。研究结果表明:各试件具有类似的破坏特征,主要呈明显的腰鼓状破坏,且发生在锈蚀区;随着锈蚀钢管体积损失率增大,锈蚀CFST柱的承载力、刚度和延性均出现不同程度的降低;在锈蚀钢管体积损失率和面积损失率相同的情况下,就局部锈蚀位置影响而言,中部影响最大;就锈蚀程度表征参数影响而言,锈蚀钢管体积损失率影响最大,面积损失率次之,壁厚损失率最小;本文提出的简化实用公式可为圆钢管混凝土构件全寿命设计提供参考依据。 展开更多
关键词 圆钢管混凝土短柱 局部锈蚀 轴压承载力 退化机制
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视觉SLAM方法综述 被引量:2
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作者 王朋 郝伟龙 +2 位作者 倪翠 张广渊 巩慧 《北京航空航天大学学报》 EI CAS CSCD 北大核心 2024年第2期359-367,共9页
实时定位与建图(SLAM)技术搭载特定传感器,使移动机器人在无任何环境先验条件下,在运动过程中自主建立环境模型来计算自身位姿,大幅提高其自主导航能力,以及对不同应用环境的适应性。视觉SLAM方法以相机作为外部传感器,通过采集周围环... 实时定位与建图(SLAM)技术搭载特定传感器,使移动机器人在无任何环境先验条件下,在运动过程中自主建立环境模型来计算自身位姿,大幅提高其自主导航能力,以及对不同应用环境的适应性。视觉SLAM方法以相机作为外部传感器,通过采集周围环境信息来创建地图并实时估计机器人自身位姿。为此,介绍了具有代表性的经典视觉SLAM方法及与深度学习相结合的视觉SLAM方法,分析了视觉SLAM方法中采用的不同特征检测方法、后端优化、闭环检测,以及动态环境下视觉SLAM方法的应用,总结了视觉SLAM方法的问题,并探讨了视觉SLAM方法在未来的热点研究方向和发展前景。 展开更多
关键词 视觉实时定位与建图 深度学习 特征检测 位姿估计 闭环检测
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用于多通道单分子定位的高精度图像配准方法 被引量:1
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作者 林丹樱 龚振权 +3 位作者 黄黎琳 聂梦娇 于斌 屈军乐 《物理学报》 SCIE EI CAS CSCD 北大核心 2024年第6期374-385,共12页
单分子定位技术可以绕过光学系统的衍射限制,在生物样品的单粒子追踪和超分辨显微成像中得到了广泛应用.多通道单分子定位采用多个成像通道,可以实现对不同目标的同时追踪或多色超分辨成像,也可以提升单粒子追踪的轴向深度或实现更高的... 单分子定位技术可以绕过光学系统的衍射限制,在生物样品的单粒子追踪和超分辨显微成像中得到了广泛应用.多通道单分子定位采用多个成像通道,可以实现对不同目标的同时追踪或多色超分辨成像,也可以提升单粒子追踪的轴向深度或实现更高的定位精度和密度.但各通道图像间的差异会影响协同定位或定量分析,因此图像配准是其图像数据预处理的关键环节;且由于单分子定位精度高,其对多通道图像配准精度的要求也很高.现有技术一般采用基于控制点的配准方法,且多采用复杂而精密的方式来获取基准物网格图像用于定位得到控制点对,以实现高精度图像配准,对样品或实验设备要求高,难以直接推广.为此,本文基于局部非线性变换和误匹配点剔除,发展了一种可以直接采用随机分布荧光珠样品作为基准物的高精度图像配准方法,通过在特征匹配和变换模型参数估计的过程中对控制点进行监测和迭代筛选,以剔除因单分子定位不准确或精度差而导致未精确匹配的控制点对,从而消除以随机分布荧光珠样品作为基准物时对于控制点准确获取和精确匹配所带来的不良影响,同时采用基于局部加权平均的二阶多项式拟合进行变换模型参数估计,以更好地适用于不同通道间存在局部非线性形变的情形.结果表明,采用该方法只需要3次迭代,就可以将未准确定位和精确匹配的控制点对找到并剔除,从而实现更准确的变换模型参数估计,将配准精度提高一个数量级,在图像局部非线性形变情况严重的正交像散双通道单分子定位成像系统中实现了约6 nm的配准精度. 展开更多
关键词 单分子定位 多通道成像 图像配准 误匹配点剔除
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关节镜下自体骨软骨移植对膝关节局限性软骨损伤的临床疗效评价 被引量:2
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作者 李杰峰 金艳南 +3 位作者 王庆东 康乐 徐向峰 李付彬 《组织工程与重建外科》 CAS 2024年第1期83-86,92,共5页
目的探讨关节镜下自体骨软骨移植术对膝关节局限性软骨损伤的临床疗效,并以磁共振成像(MRI)检查对疗效进行评价。方法选取2018年6月至2021年6月诊治的100例膝关节局限性软骨损伤患者,按随机数字表法分为研究组和对照组,每组各50例。研... 目的探讨关节镜下自体骨软骨移植术对膝关节局限性软骨损伤的临床疗效,并以磁共振成像(MRI)检查对疗效进行评价。方法选取2018年6月至2021年6月诊治的100例膝关节局限性软骨损伤患者,按随机数字表法分为研究组和对照组,每组各50例。研究组采取关节镜下自体骨软骨移植术,对照组采取微骨折术治疗。采用MRI评估其手术疗效,并记录其术后膝关节软骨愈合时间;采用Lysholm膝关节功能评分表、国际膝关节文献委员会(IKDC)膝关节评估表,评估患者治疗前后膝关节功能变化;统计患者术后并发症发生率。结果研究组关节软骨愈合优良率98.00%,高于对照组84.00%(P<0.05)。两组术前和术后3个月的Lysholm评分、IKDC评分比较差异无统计学意义(P>0.05);术后6、12、24个月,研究组Lysholm评分、IKDC评分均高于对照组(P<0.05)。两组患者术后均无严重并发症,且并发症发生率差异无统计学意义(P>0.05)。研究组术后膝关节软骨愈合时间短于对照组(P<0.05)。结论关节镜下自体骨软骨移植术对膝关节局限性软骨损伤的远期治疗效果显著,可有效改善患者术后膝关节功能,缩短膝关节软骨愈合时间,安全性高。 展开更多
关键词 关节镜 自体骨软骨移植术 膝关节局限性软骨损伤 磁共振成像 膝关节功能
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四季秋海棠BsMYB62的抗旱性功能研究 被引量:1
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作者 刘保国 张艳文 +4 位作者 姚珂心 史志坤 李菲 李永华 张开明 《西北农林科技大学学报(自然科学版)》 CSCD 北大核心 2024年第4期95-104,共10页
【目的】以前期从四季秋海棠叶片中克隆得到的R2R3型MYB转录因子BsMYB62为研究对象,分析其在干旱胁迫下的功能。【方法】对四季秋海棠MYB62蛋白进行亚细胞定位,并通过实时荧光定量PCR方法明确BsMYB62基因在四季秋海棠根、茎、叶、雄花... 【目的】以前期从四季秋海棠叶片中克隆得到的R2R3型MYB转录因子BsMYB62为研究对象,分析其在干旱胁迫下的功能。【方法】对四季秋海棠MYB62蛋白进行亚细胞定位,并通过实时荧光定量PCR方法明确BsMYB62基因在四季秋海棠根、茎、叶、雄花和雌花5个组织部位中的表达情况;构建BsMYB62基因的过表达载体转化到拟南芥,观察过表达转基因株系与野生型植株在萌发期和幼苗期遭受干旱胁迫时的生长表型、种子萌发和根长情况,测定各株系在幼苗期干旱胁迫处理时的叶绿素荧光参数PSⅡ最大光化学效率(F_(v)/F_(m)),叶绿素、丙二醛(MDA)、脯氨酸(Pro)含量,抗氧化酶(SOD、POD、CAT)活性以及转基因株系中BsMYB62基因的相对表达量变化。【结果】BsMYB62定位于四季秋海棠的细胞核,其在根、茎、叶和雌雄花中均有表达,其中以根和茎中的表达水平较高。在MS培养基中,野生型拟南芥和3个BsMYB62过表达转基因株系(OE1、OE2和OE3)的发芽率和长势均无显著差异,而在200 mmol/L甘露醇(模拟干旱胁迫)培养基中,OE1、OE2和OE3在胁迫处理后前2 d的发芽率及主根长均显著高于野生型拟南芥,幼苗长势也明显优于野生型。置于培养土中干旱胁迫1 d时,OE1、OE2和OE3的BsMYB62即被显著诱导;干旱胁迫13 d时,OE1、OE2和OE3的F_(v)/F_(m)、叶绿素含量、Pro含量以及SOD、POD和CAT活性均显著高于野生型拟南芥,而MDA含量则显著低于野生型拟南芥。【结论】BsMYB62基因通过提高转基因拟南芥的光合潜能和抗氧化能力,显著增强其对干旱胁迫的抗性。 展开更多
关键词 四季秋海棠 BsMYB62转录因子 亚细胞定位 组织特异性表达 干旱胁迫
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关系研究与本土传播:一种媒介化的视野 被引量:1
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作者 李红 刘慧钰 《中州学刊》 北大核心 2024年第3期169-176,共8页
“关系”概念是一个相对比较成熟的本土化理论成果,它与传播具有天然的亲缘关系,可以援用到传播学研究中。媒介作为基础设施可被视为关系研究的关键变量,以填补既有研究的缺失。在中国,关系并非一个本质化的概念,而是人们处理问题的方法... “关系”概念是一个相对比较成熟的本土化理论成果,它与传播具有天然的亲缘关系,可以援用到传播学研究中。媒介作为基础设施可被视为关系研究的关键变量,以填补既有研究的缺失。在中国,关系并非一个本质化的概念,而是人们处理问题的方法,其内涵充满开放性、经验性和历史感。它可被视为传播学得以本土化的有效通道,而媒介正是其支点。媒介可通过组织时空、培养惯习、重构权力等方式逐步实现对关系形态和关系文化的重塑。因此,传播学本土化可从媒介实践入手,关注媒介对于关系形态及其文化的影响,并将其对接到诸如乡土社会的维系和变迁以及社会治理等议题的讨论中。 展开更多
关键词 关系研究 媒介化 本土化
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基于IMU-LiDAR紧耦合的煤矿防冲钻孔机器人定位导航方法 被引量:1
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作者 司垒 王忠宾 +4 位作者 魏东 顾进恒 闫海峰 谭超 朱远胜 《煤炭学报》 EI CAS CSCD 北大核心 2024年第4期2179-2194,共16页
防冲钻孔机器人是冲击地压矿井卸压的关键设备,其在复杂卸压巷道的精确地图构建和的稳定导航是实现钻孔作业智能化的基础和前提。在分析激光雷达点云畸变成因和同步定位与地图构建(SLAM)算法缺陷的基础上,设计了基于惯性测量单元(IMU)... 防冲钻孔机器人是冲击地压矿井卸压的关键设备,其在复杂卸压巷道的精确地图构建和的稳定导航是实现钻孔作业智能化的基础和前提。在分析激光雷达点云畸变成因和同步定位与地图构建(SLAM)算法缺陷的基础上,设计了基于惯性测量单元(IMU)连续时间轨迹的点云畸变矫正方法,建立了激光雷达和IMU的数据融合模型,提出了基于IMU-LiDAR紧耦合的防冲钻孔机器人定位建图方法。根据煤矿卸压巷道特点建立了密闭坡道模型,开展了建图效果仿真分析,结果表明,所提算法在定位精度、轨迹误差方面均优于现有常用算法。在此基础上,设计了基于改进人工势场法和快速扩展随机树的动态路径规划方法,建立了适用于防冲钻孔机器人的路径规划与导航融合方案,并设计了2种仿真运动场景,结果表明,所提路径规划方法在全局路径规划和动态路径规划的平均路径长度、平均运行时间、平均生成节点数等方面均具有较好的综合性能。为了进一步验证防冲钻孔机器人定位导航方法的实用性,在校内模拟巷道、地面实验基地和井下卸压巷道等场景下开展了多组对比实验,结果表明:将IMU数据与LiDAR数据紧耦合后,所提方法的定位建图精度明显提高,在特征退化场景中具有优越的定位建图性能,且规划路径的运算效率和路径代价方面均具有良好的表现,验证了所提定位导航方法在多种场景中的可行性和优越性。 展开更多
关键词 防冲钻孔机器人 同步定位与地图构建 惯性-雷达融合 定位导航 路径规划
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