检索结果-南通市图书馆

influence of erbium on structural,and charged particles,photons,and neutrons shielding properties of ba_(1-x)Er_(x)SnO_(3) perovskite ceramics

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第4期42卷 724-732页

作者： M.K.h.Hamad Nidal Dwaikat M.H.A.Mhareb M.i.Sayyed R.M.Hamad Y.S.M.Alajerami M.A.Almessiere Gameel Saleh Ahmad Hussein Alomari K.A.Ziq Department of basic Sciences School of Social and Basics SciencesAl Hussein Technical UniversityKing Abdullah II St 242Amman11831Jordan Department of Physics College of Engineering and PhysicsInterdisciplinary Research Center for Advanced MaterialsKing Fahd University of Petroleum&MineralsDhahran31261Saudi Arabia Department of Physics College of ScienceImam Abdulrahman Bin Faisal UniversityP.O.Box 1982Dammam31441Saudi Arabia basic and Applied Scientific Research Center Imam Abdulrahman Bin Faisal UniversityP0.Box 1982Dammam31441Saudi Arabia Department of Physics Faculty of ScienceIsra UniversityAmman11622Jordan Department of Nuclear Medicine Research Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityPo.Box 1982Dammam31441Saudi Arabia Medical imaging Department Applied Medical Sciences FacultyAl Azhar University-Gaza CityPo.Box 1277Palestine Department of Biophysics Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityPo.Box1982Dammam 31441Saudi Arabia Department of Biomedical Engineering College of EngineeringImam Abdulrahman Bin Faisal UniversityPo.Box 1982Dammam31441Saudi Energy&Minerals Regulatory Commission Amman11821Jordan

Five perovskite ceramics samples of ba_(1-x)Er_(x)SnO_(3) with x=0.00,0.05,0.10,0.15,and 0.20 were synthesized using the conventional solid-state reaction *** prepared samples were characterized by X-ray diffraction(XRD),Fourier transforms infrared(FTiR),and UV-Vis *** shielding properties against ionizing radiation were also *** XRD analysis shows the perovskite cubic structure as the major phase in all *** FTiR reveals a distinctive band around 614-620 cm^(-1) ascribed to the antisymmetric O-Sn-O ***-Vis spectroscopy was used to determine the bandgap according to diffuse reflectance,and the results display a fixed enhancement in the bandgap from 3.2 to 3.3 eV for all ***-ray shielding properties of the synthesized samples were experimentally measured and compared with XCOM computational *** relative differences(Δ,%)between experimental and theo retical values are low and fall within the 0.446%-7.10%*** addition of Er leads to the enhanced density,neutron,and gamma shielding *** contrast,charged particles’shielding parameters gradually reduce with rising Er *** results suggest that ba_(1-x)Er_(x)SnO_(3) samples can be used in different radiation shielding applications.

关键词： Perovskite Ceramics Gamma ray shielding Mass stopping power Rare earths

山地旅游安全事故致因研究——基于“三山五岳”的文本案例

在线全文

学校读者我要写书评

暂无评论

干旱区资源与环境 2024年第3期38卷 201-208页

作者：黄佳杰巴兆祥复旦大学旅游学系上海200433

以国内外知名的“三山五岳”景区作为研究对象,搜集其相关的178个旅游安全事故典型案例,基于扎根理论对事故致因进行分析与讨论。结果表明:1)山地旅游安全事故的致因根据比重依次为:人为因素、环境因素、设备因素以及管理因素。2)致因... 详细信息

以国内外知名的“三山五岳”景区作为研究对象,搜集其相关的178个旅游安全事故典型案例,基于扎根理论对事故致因进行分析与讨论。结果表明:1)山地旅游安全事故的致因根据比重依次为:人为因素、环境因素、设备因素以及管理因素。2)致因分别对应8个子集:游客不安全行为、当地人不安全行为、天气不安全因素、陆地不安全因素、游客装备不齐全、设施设备不安全、管理水平低以及救援水平有限。3)借鉴旅游安全事故因果连锁理论,结合分析的要素与逻辑,建构了山地旅游安全分析模型。以政府、企业和游客三个维度为切入,为山地旅游业提出对策建议。

关键词：山地旅游旅游安全旅游事故扎根理论事故致因

基于地缘环境视角的地缘破碎带历史演进解析——以南高加索地区为例

在线全文

学校读者我要写书评

暂无评论

地理学报 2024年第6期79卷 1592-1611页

作者：巴士奇陈瑛姚宇阳李淦叶帅陕西师范大学地理科学与旅游学院西安710119 江苏理工学院文化与旅游学院常州213001

地缘破碎带是全球冲突和大国竞争的主要区域,具备外部挤压性、内部分裂性、过程动态性等基本特征,是域内外双重尺度作用下共同形成的地理区域。地缘破碎带的基本特征与发展模式契合于地缘环境研究的核心理念,在地缘环境视角下,地缘破碎... 详细信息

地缘破碎带是全球冲突和大国竞争的主要区域,具备外部挤压性、内部分裂性、过程动态性等基本特征,是域内外双重尺度作用下共同形成的地理区域。地缘破碎带的基本特征与发展模式契合于地缘环境研究的核心理念,在地缘环境视角下,地缘破碎带是一个以域内外多元行为体互动实践为核心的不断发展演化的地理区域。通过互动实践,破碎带产生的决策信息集成为制约相关行为体发生行动的物质性与理念性因素,在此约束下,这些决策行动在时序上的排列关联构成了破碎带历史演进的核心内容。选取亚欧交界处的南高加索地区为研究区域,自1991年南高加索三国独立以来,该地区历经复杂的内部冲突与外部博弈,是地缘破碎带分析的典型案例。本文构建出地缘环境视角下地缘破碎带历史演进的分析框架,从本底要素、关联要素、结构要素3类视角解析1991年南高加索地区三国独立后至2020年底的历史演进过程及阶段性特征,并从跨领域互动、跨尺度耦合和多元行为体博弈3方面分析推动演进的内在路径,以地缘政治学理论视角多维化呈现地缘破碎带的历史演进过程,尝试将地理学研究的区域性、综合性、尺度性等基本思维模式融入历史学与国际关系学研究中。

关键词：地缘破碎带地缘环境多元行为体历史演进南高加索地区

Are all primary omental infarcts truly idiopathic?Five case reports

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第24期12卷 5596-5603页

作者： Haldun Kar Danial Khabbazazar Nihan Acar Şebnem Karasu Halis bağ Fevzi Cengiz Osman Nuri Dilek Department of General Surgery Katip Celebi University Ataturk Training and Research Hospitalİzmir 35150Türkiye Department of Radiology İzmir Katip Celebi UniversitySchool of Medicineİzmir 35150Türkiye Department of Surgery İzmir Katip Celebi UniversitySchool of Medicineİzmir 35150Türkiye

baCKGROUND idiopathic omental infarction(iOi)is challenging to diagnose due to its low incidence and vague *** differential diagnosis also poses difficulties because it can mimic many intra-abdominal organ *** hypercoagulability and thrombosis are among the causes of omental infarction,venous thromboembolism scanning is rarely performed as an etiological *** SUMMARY The medical records of the 5 cases,who had the diagnosis of iOi by computed tomography,were *** majority of the patients were male(n=4,80%)and the mean age was 31 years(range:21-38).The patients had no previous abdominal surgery or a history of any chronic *** main complaint of all patients was persistent abdominal *** infarction was detected in all patients with contrast-enhanced computed *** treatment was initially preferred in all patients,but it failed in 1 patient(20%).After discharge,all patients were referred to the hematology department for thrombophilia *** 1 patient applied for thrombophilia screening and was homozygous for methylenetetrahydrofolate reductase(A1298C mutation)and heterozygous for a factor V leiden *** iOi should be considered in the differential diagnosis in patients presenting with progressive and/or persistent right side abdominal *** risk factors such as hypercoagulability in patients with iOi is also important in preventing future conditions related to venous thromboembolism.

关键词： Omental infarction Acute abdominal pain Thrombophilia screening Factor V leiden Methylenetetrahydrofolate reductase Case report

Results of the First 10 Cases of Coronary Bypass Surgery in Senegal

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

World Journal of Cardiovascular Surgery 2024年第4期14卷 45-60页

作者： Papa Amath Diagne Jean Claude Ndiogou Dione Papa Ousmane ba Momar Sokhna Diop El Hadji Boubacar ba Momar Dioum Marième Soda Mbaye Moussa Seck Diop Mory Camara Abdou lahad Mbengue Abdou Aziz Thiaw Abdoul Khoudoss Diallo Moussa Mareme Samba Dialtabé ibrahima Guéssé ba Anta Mbaye Sall Papa Salmaneba Amadou Gabriel Ciss Department of Cardiovascular and Thoracic Surgery FANN National University Hospital Dakar Senegal

This is a review of the first 10 coronary artery bypass surgeries performed by the local team. The mean age was 62 years old [45 - 74]. The patients were predominantly male, with a M/F ratio of 4:1. Cardiovascular risk factors were mainly myocardial infarction (Mi) (60%), hypertension (50%), obesity (40%) and diabetes (30%), with at least two risk factors per patient. Angina was the main symptom (80%). The average time from presentation to surgery was 8 months. The mean Euroscore 2 was 2.92 ± 1.65 [1.33 - 6.60]. Coronary angiography revealed an average of 2 lesions per patient, with 3-vessel involvement in 70% of cases: the interventricular artery (iVA) (100%), the right coronary artery (90%) and the circumflex artery (70%). On echocardiography, the mean left ventricular ejection fraction (lVEF) was 59% [33% - 76%]. All patients underwent median sternotomy with bypass grafting. The average duration of the cardiopulmonary bypass was 150 min [46 - 275 min];that of aortic clamping, 120 min [43 - 232 min]. The grafts used were internal thoracic artery (iTA) in 100% of cases (80% on the left and 20% on the right), and the great saphenous vein (GSV) in 60% of cases (50% on the left and 10 on the right). Double bypass was performed in 60% of cases, single bypass in 30% and triple bypass in 10%. The bypasses were performed on the iVA (100%), the middle lateral of the circumflex (30%) and the bisector (20%). The average time to extubation was 11 hours and the length of stay in the intensive care unit was 7 days [03 - 17 days]. One patient had a reoperation on Day 0 post-op. The average hospital stay was 13 days [06 - 27 days]. Complications occurred in nine of the patients (90%), with a predominance of infectious and neurological complications. Overall operative mortality was 3%, all in intensive care.

关键词： Coronary Bypass Surgery Coronary lesions Cardiac Surgery Senegal

From Fostering to Delusional Disorder of Filiation

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

Open Journal of Psychiatry 2024年第4期14卷 283-286页

作者： Momar Camara Wissem Masmoudi El Hadji Makhtar ba Sokhna Seck Maïmouna Dieye Aïda Sylla Department of Psychiatry and Medical Psychology Cheikh Anta Diop University Dakar Senegal Thiaroye National Psychiatric Hospital Center Dakar Senegal Fann National University Hospital Center Dakar Senegal Albert Royer Childrens Hospital Dakar Senegal

introduction: Fostering is a widespread practice in West Africa. it played an essential role in the circulation of children. The failure of its community regulation, not compensated by a legal framework, has made its practice precarious. Observation: A case study was conducted on Dior, who was hospitalised in a psychiatric ward for a delusional disorder of filiation. Dior was entrusted to her maternal grandmother and aunt at ages 2 and 9. During these fosterings, the place of the symbolic father was not substituted, causing a void that challenged her imagination. The outcome was an inscription in a genealogy where she had found herself with prestigious parents. Discussion: Fostering has strongly disrupted the family dynamics in Dior’s case. One of her options was to assume the paternal function, the use of which was perceived as a defiance or even a transgression. This same function would be a starting point of a psychosis whose filial character would only be an attempt at rectification where reality and imagination collide. Conclusion: Our study reveals the importance of stable parental figures at stake in fostering contexts, which constitute a risk factor for the development of a subsequent psychosis.

关键词： Delusional Disorder of Filiation Psychopathology interactions Fostering Family

计算机断层扫描在工业遗产文物保护中的应用研究

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

热加工工艺 2024年第17期53卷 78-83页

作者：巴玥温瑀燕山大学河北秦皇岛066004

针对工业遗产的钢材结构表面及内部的孔隙、裂缝等微观缺陷,采用计算机断层扫描系统进行三维可视化,检测出缺陷位置,随后采用激光再制造技术以Fe-Cr-Mo+8wt%Al2O3复合粉末对缺陷位置进行精确修复。结果表明:经激光再制造后试样表面裂纹... 详细信息

针对工业遗产的钢材结构表面及内部的孔隙、裂缝等微观缺陷,采用计算机断层扫描系统进行三维可视化,检测出缺陷位置,随后采用激光再制造技术以Fe-Cr-Mo+8wt%Al2O3复合粉末对缺陷位置进行精确修复。结果表明:经激光再制造后试样表面裂纹和气孔显著减少,修复层主要由固溶体FeCr相、碳化物M(Fe,Cr,Mo)7C3、金属间化合物Fe3Al和陶瓷相Al2O3组成,显著提高了原始表面的耐腐蚀性。

关键词：工业遗产激光再制造计算机断层扫描

基于抚育整枝目标的毛白杨枝条冲击切割性能适应性分析

在线全文

学校读者我要写书评

暂无评论

北京林业大学学报 2024年第4期46卷 158-166页

作者：吕坤班以琛坝仕宏刘洋文剑北京林业大学工学院林业装备与自动化国家林业和草原局重点实验室北京100083

【目的】为了提高毛白杨枝条冲击切割效率并改善切割效果,通过研究枝条内部因素对切割性能的影响,对毛白杨枝条的冲击切割性能进行适应性分析。【方法】以我国华北地区林场广泛种植的速生林品种毛白杨的枝条为研究对象,使用自制的枝条... 详细信息

【目的】为了提高毛白杨枝条冲击切割效率并改善切割效果,通过研究枝条内部因素对切割性能的影响,对毛白杨枝条的冲击切割性能进行适应性分析。【方法】以我国华北地区林场广泛种植的速生林品种毛白杨的枝条为研究对象,使用自制的枝条切割平台进行枝条切割试验。在单因素试验的基础上采用Box-Benhnken中心组合试验方法,通过试验和理论研究枝条直径、含水率和分枝角度3个内部因素对峰值切割力和断裂效果的影响规律。【结果】(1)建立了毛白杨枝条冲击切割性能的切割机理模型;(2)通过对模型进行优化分析,得到最优参数组合为枝条直径14.7 mm、含水率14.0%、分枝角度90°,该组合下的峰值切割力为370.48 N,断裂效果评分为4.6分,峰值切割力和断裂效果分数的预测值与实测值的相对偏差均小于5%;(3)峰值切割力与枝条直径呈线性增长关系,随枝条含水率的增大呈先增大后减小的趋势,随着分枝角度的增大而小幅增大。【结论】选择树龄为7年时进行修枝作业,作业的季节选择秋冬季,可以获得较优的修枝质量,该研究可为速生林修枝装备的研发与林木抚育方式的优化结合提供数据支撑。

关键词：机械化抚育整枝冲击切割毛白杨枝条切割适应性切割质量参数

Effectively modulating spatial vortex four-wave mixing in a diamond atomic system

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第4期33卷 473-478页

作者：巴诺姜明奇费金友王丹蒋海林王磊王海华 National Demonstration Center for Experimental Physics Education College of PhysicsJilin Normal UniversitySiping 136000China College of Physics Jilin UniversityChangchun 130012China

Due to the spatial characteristics of orbital angular momentum,vortex fields can be applied in the fields of quantum storage and quantum *** study the realization of spatially modulated vortex fields based on four-wave mixing in a four-level atomic system with a diamond *** intensity and spiral phase of the vortex field are effectively transferred to the generated four-wave mixing *** changing the detuning of the probe field,the phase and intensity of the generated vertex four-wave mixing field can be *** the probe field takes a large detuning value,the spatial distribution of the intensity and phase of the vertex four-wave mixing field can be effectively tuned by adjusting the Rabi frequency or detuning value of the coupled *** the same time,we also provide a detailed explanation based on the dispersion relationship,and the results agree well with our simulation results.

关键词： coherent optical effects four-wave mixing orbital angular momentum