检索结果-南通市图书馆

Microstructural Feature of As-cast A-356 Alloy Modifiers with the Addition of SrO

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2014年第3期29卷 617-619页

作者： MU?IZ rodrigo FLORES Alfredo ORTIZ Juan rodríguez nelly MARTíNEZ Fernando OROZCO Pilar LUNA Jesús Equihua Fabián García Adrián Faculty of Engineering Autonomous University of Coahuila Camporedondo UnitSaltillo Coahuila México CINVESTAV Saltillo Unit Department of Metal Mechanics Technological Institute of Saltillo Faculty of Engineering Autonomous University of Zacatecas FIME Autonomous University of Coahuila Unit

To explore the effect of strontium on the structure of as-cast A356 alloy, the strontium was incorporated to the alloy by metallothermic reduction of SrO where the mineral was added to the melt through the submerged powders injection technique. The evaluation of the modification of the eutectie silicon and the chemical analysis of samples were done using optical microscopy （OP） and inductively coupled plasma （ICP）, respectively, while microstructural analyses by scanning electron microscopy （SEM）, and the injection time was variable. Magnesium was added to the melt to increase the reactivity and reduce the surface tension of the molten aluminum. It was possible to increase the strontium content from 0 to 0.027% after 20 minutes treatment. This concentration was sufficient to bring about full modification structure of eutectic silicon of as cast alloy A 356 and the acceptable quality metallurgical of alloy.

关键词： modification microstmcture strontium eutectic silicon submerged powder injection

Synergy of sodium doping and nitrogen defects in carbon nitride for promoted photocatalytic synthesis of hydrogen peroxide

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第8期35卷 324-329页

作者： Fabrice nelly Habarugira Ducheng Yao Wei Miao Chengcheng Chu Zhong Chen Shun Mao College of Environmental Science and Engineering State Key Laboratory of Pollution Control and Resource ReuseTongji UniversityShanghai 200092China Baowu Water Technology Co. Ltd.Research InstituteShanghai 201999China

Photocatalytic synthesis of hydrogen peroxide has gradually become a promising method for in-situ pro-duction of hydrogen peroxide,which relies on sustainable solar ***,the commonly used photocatalyst,i.e.,carbon nitride(CN),still suffers from the drawbacks of narrow light absorption range and fast charge ***,we report a facile method to introduce nitrogen defects into carbon nitride together with sodium *** adjusting the ratio of sodium dicyandiamide,the band gap of carbon nitride can be controlled,while the carrier separation and transfer ability of carbon nitride is *** modified CN with sodium doping and nitrogen defect(SD-CN)demonstrates outstanding H_(2)O_(2)pro-duction performance(H_(2)O_(2)yield rate of 297.2μmol L^(−1)h^(−1))under visible light irradiation,which is approximately 9.8 times higher than that of pristine *** work deepens the understanding of the coordinated effect of structural defect and element doping of carbon nitride on the photocatalytic H_(2)O_(2)production performance,and provides new insight into the design of photocatalytic system for efficient production of H_(2)O_(2).

关键词： Photocatalysis H_(2)O_(2)evolution Sodium doping Nitrogen defect Metal-free catalyst

Angular unconformity in Pennsylvanian strata from 3-D seismic interpretation,Goldsmith Field,West Texas

在线全文

学校读者我要写书评

暂无评论

Energy Geoscience 2024年第2期5卷 298-303页

作者： Edwin I.Egbobawaye nelly Omoruyi Abdulmutallib Aminu Robert Trentham Mohamed K.Zobaa Sumit Verma Kinder Morgan MidlandTX79705USA Department of Geosciences University of Texas Permian BasinOdessaTX79762USA

The Pennsylvanian unconformity,which is a detrital surface,separates the beds of the Permian-aged strata from the Lower Paleozoic in the Central Basin *** data interpretation indicates that the unconformity is an angular unconformity,overlying multiple normal faults,and accompanied with a thrust fault which maximizes the region's structural ***,the Pennsylvanian angular unconformity creates pinch-outs between the beds above and *** computed the spectral decomposition and reflector convergence attributes and analyzed them to characterize the angular unconformity and *** spectral decomposition attribute divides the broadband seismic data into different spectral bands to resolve thin beds and show thickness *** contrast,the reflector convergence attribute highlights the location and direction of the pinch-outs as they dip south at angles between 2° and 6°.After reviewing findings from RGB blending of the spectrally decomposed frequencies along the Pennsylvanian unconformity,we observed channel-like features and multiple linear bands in addition to the faults and *** can be inferred that the identified linear bands could be the result of different lithologies associated with the tilting of the beds,and the faults may possibly influence hydrocarbon migration or act as a flow barrier to entrap hydrocarbon *** identification of this angular unconformity and the associated features in the study area are vital for the following reasons:1)the unconformity surface represents a natural stratigraphic boundary;2)the stratigraphic pinch-outs act as fluid flow connectivity boundaries;3)the areal extent of compartmentalized reservoirs'boundaries created by the angular unconformity are better defined;and 4)fault displacements are better understood when planning well locations as faults can be flow barriers,or permeability conduits,depending on facies heterogeneity and/or seal effectiveness of a fault,which

关键词： Pennsylvanian unconformity Seismic data interpretation Spectral decomposition Reflector convergence Reservoir characterization

Comparative Quantitative Analysis of Retinal Superficial Capillary Plexus in Patients with Retinal Vein Occlusion and Unaffected Fellow Eyes

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 Ophthalmology 2024年第3期14卷 218-228页

作者： Sinan Aptikadir nelly Sivkova Department of Ophthalmology Faculty of Medicine Medical University of Plovdiv Plovdiv Bulgaria University Eye Clinic St. George University Hospital Plovdiv Bulgaria

Purpose: To evaluate optical coherence tomography angiography (OCT-A) data obtained from the superficial retinal capillary plexus of patients with retinal vein occlusion and comparative analysis with data registered from unaffected fellow eyes. Methods: The examined patients were classified into 2 groups: group 1—eyes with established retinal vein occlusion (n = 29) and group 2—unaffected fellow eyes of patients with retinal vein occlusion (n = 24). The scanning protocol “Angiography 3 × 3 mm” of Zeiss Cirrus HD-OCT 6000, AngioPlex Metrix was used to evaluate the retinal superficial capillary plexus. The analyzed parameters were vascular density and perfusion density, as well as the area, perimeter, and circularity of the foveolar avascular zone (FAZ). Results: The comparative analysis of FAZ parameters at the superficial capillary plexus (SCP) between group 1 (eyes with retinal vein occlusion) and group 2 (unaffected fellow eyes) showed significant results for the three parameters, respectively area (p = 0.003), perimeter (p ≤ 0.001), and circularity (p = 0.011) of FAZ. The comparative analysis of the vascular network at SCP in patients with diagnosed retinal vein occlusion and unaffected fellow eyes showed significant results for vascular density (VD) in the central (p = 0.038) and inner (p ≤ 0.001) zones as well as total VD (p ≤ 0.001) were statistically significant. Moreover, the results obtained in the study of vascular perfusion (VP) indicated significant results in the inner zone (p ≤ 0.001) and total VP (p = 0.001). Vascular perfusion in the central zone (p = 0.116) was the only parameter not to meet significant results. Conclusion: The current study observed a significant enlargement of the FAZ and loss of its circularity, along with a reduction in vascular network parameters at the superficial retinal capillary plexus level.

关键词： Retinal Vein Occlusion Optical Coherence Tomography Angiography Superficial Retinal Capillary Plexus

Clinical features of chronic kidney disease in dogs with the serological presence of Leptospira spp.,Ehrlichia canis,and Anaplasma phagocytophilum

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Animal Diseases 2024年第3期4卷 224-230页

作者： Claire A.Vázquez‑Manzanilla María F.Cárdenas‑Marrufo Eduardo Gutiérrez‑Blanco Matilde Jiménez‑Coello nelly R.Pech‑Sosa Antonio Ortega‑Pacheco Departamento de Salud Animal y Medicina Preventiva Facultad de Medicina Veterinaria y ZootecniaCampus de Ciencias Biológicas y AgropecuariasUniversidad Autónoma de YucatánMéridaYucatán 97100México Unidad Interinstitucional de Investigación Clínica y Epidemiológica Facultad de MedicinaUniversidad Autónoma de YucatánMéridaYucatán 97000México

Chronic kidney disease is commonly diagnosed in dogs,and clinical signs may be aggravated when infected agents are *** this case report,33 dogs with chronic kidney disease were clinically evaluated and serologically tested for Leptospira spp.,Ehrlichia canis,and Anaplasma *** seroprevalence for Leptospira *** 39.4%.The most frequent serovars found were Pyrogenes,Canicola,Bratislava and Australis,with serological titers between 1:100 to 1:*** signs included fever,depression,decreased body condition,vomiting and hema‑*** laboratory fndings were anemia,leukocytosis,thrombocytopenia,increased liver enzymes,urea and creatinine,hyperbilirubinemia and *** leptospira seronegative dogs were positive for one or both monitored homoparasites(i.e.,*** and ***);only three leptospira seropositive dogs were positive for one or both *** also suggest that endemic hemoparasites of dogs should be moni‑tored in dogs with a kidney condition for a better clinical picture of the patients and therapeutic approach.

关键词： Anaplasma Chronic kidney disease Dog Ehrlichia Leptospira

Acceptance and Experience of HIV-Infected Adolescents in Two Hospitals in Yaoundé

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 Pediatrics 2024年第2期14卷 435-443页

作者： Isabelle Mekone Nkwele nelly Kamgaing Pierrette Amanda Emah Manga Jeannette Épée Ngoué Hélène Kamo Sélangai Claude Audrey Meguieze Nsoh Ndeh-Fofang Serge Tchoukoua Jean-Baptiste Fotso Djemo Paul Koki Ndombo Department of Pediatrics Faculty of Medicine and Biomedical Sciences University of Yaoundé I Yaoundé Cameroon Institut Supérieur des Sciences de la Santé de Bangangté Université des Montagnes Bangangté Cameroon Faculty of Medicine and Biomedical Sciences University of Garoua Garoua Cameroon

Introduction: Access to antiretroviral drugs has improved the survival of children infected with the Human Immunodeficiency Virus (HIV). As they reach adolescence, they are confronted with various constraints related to the infection and its treatment, in addition to those of the growth period they are going through. The main aim of the study was to assess the acceptance and describe the experience of HIV infection by infected adolescents but also to investigate the factors associated with good acceptance and a positive experience. Methodology: The cross-sectional analytic study concerned HIV-infected adolescents aged 15 to 19 followed up at the Chantal Biya Foundation-Mother and Child Centre (CME-FCB) and the Yaoundé University Hospital Centre (CHUY) between February 2020 and June 2020. The study saw participants complete a questionnaire containing socio-demographic data and assessing acceptance and experience with the infection. Data analysis was accomplished using Epi info software version 7.***.2.6. Results: One hundred and thirteen HIV-infected adolescents were included in the study. The sex ratio was 0.68 and the mean age was 17 years. More than half of the adolescents had a good acceptance and positive experience with the infection. Related factors were the adolescent’s perception of good health and participation in an association with other infected adolescents. Conclusion: Emphasizing the psychological and educational follow-up of infected adolescents and encouraging their participation in associations for adolescents living with HIV could reduce the consequences of poor acceptance and ensure a better transition to adulthood. .

关键词： HIV Adolescent Acceptance Experience

Determinants of Sexual Activity among HIV-Infected Adolescents in Cameroon

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 Pediatrics 2024年第5期14卷 921-936页

作者： Calixte Ida Penda Rachel Fotso Yogue nelly Noubi Kamgaing Sena Mouna Penda Loïc Boupda Francis Atéba Ndongo Christian Eyoum Ritha Mbono Betoko Grace Dalle Ngondi Patricia Epee Eboumbou Francisca Monebenimp Essome Henri Faculty of Medicine and Pharmaceutical Sciences University of Douala Douala Cameroon General Hospital of Douala Douala Cameroon Faculty of Medicine and Biomedical Sciences University of Yaound 1 Yaound Cameroon University Hospital Centre of Yaound Yaound Cameroon Mokolo Regional Hospital Annex Mokolo Cameroon University of Garoua Garoua Cameroon Mother and Child Centre of the Chantal Biya Foundation in Yaound Yaound Cameroon Douala Laquintinie Hospital Douala Cameroon District Hospital of Bonassama Douala Cameroon

Introduction: Adolescence is a period of transition to adulthood, including for HIV-infected adolescents (HIA), when sexual problems emerge. Few studies have been carried out on the sexuality of HIA. This study aimed to assess the sexual behavior of HIV-infected adolescents in Cameroon. Methodology: A cross-sectional study was conducted in three hospitals in the cities of Yaoundé and Douala, from November 2019 to June 2020. All HIA aged 13 to 19 years followed in the study who knew their HIV status were included in the study after obtaining their assent and their parent’s consent. Socio-demographic and clinical characteristics were collected, as well as sexual practices and the determinants of their sexual activity. A multivariate analysis was performed to explore the relationship between the different variables studied and the sexual activity of these adolescents. Results: Of 204 HIA enrolled in the study, 64 (31.7%) were sexually active, the mean age at first sexual intercourse was 15.6 ± 2.8 years and the sex ratio was 0.94. Of the adolescents in the study, 75.7% of girls and 61.2% of boys had regular sexual activity, while 21.3% of girls and 35.4% of boys had multiple sexual relationships in the six months preceding the study. Nearly 16 (25.0%) of the sexually active HIA had more than 2 sexual encounters per month, 6 (9.3%) of these encounters had been paid for and 9 (27.2%) of the girls had already had at least one pregnancy. More than 7 out of 10 HIA (79.6%) had used a condom the last time they had sex. Age less than 18 years [OR = 11.1 (95% CI: 3.1 - 39.4), p = 0.001], lack of remuneration [OR = 9.8 (95% CI: 2.0 - 47.4), p = 0.001] and self-care were significantly associated with sexual activity in HIA, while school attendance was a protective factor. Self-funded HIAs were 21 times more likely to be sexually active [OR = 21.6 (95% CI: 2.3 - 179), p = 0.004]. Conclusion: More than a third of HIV-infected adolescents were sexually active and risky sexual practi

关键词： HIV Adolescent Sexual Behavior Cameroon

Concept cathedral and “squaring the circle”:Interpreting the Gothic cathedral of Notre Dame de Paris as a standing hymn

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Architectural Research 2021年第2期10卷 369-393页

作者： nelly Shafik Ramzy Department:of Architectural Engineerins Faculty of EngineeringBenha UniversityEl KalyobiaEgypt

Semiotics is used in the sphere of visual arts as a tool that helps reading the message included in a certain *** architecture,as an outcome of the rich cultural context of medieval tradition,where metaphysics,numbers and geometry were indispensable tools to symbolically manifest cosmological and theological concepts,is suggested as a good example for testing this approach in the field of *** this paper,a semiotic reading for one of the most distinguished works of this era;i.e.,the cathedral of Notre Dame de Paris,is introduced as a model for this *** many message included in the building,such as the functional or the technical messages,this is a trial to introduce a reading,i.e.,an interpretation,of what could be called rta hidden spiritual messase,The paper comes to a conclusion that the Gothic cathedral,as represented in Notre Dame de Paris,might be perceived as an extemalization of a standing hymn that was meant to send continuous appeals of protection to Heaven.

关键词： Semiotics Architectural language Symbolism Gothic architecture Notre Dame de Paris

Short, Medium, and Long-Term Stroke Mortality in Libreville and Associated Factors

在线全文

学校读者我要写书评

暂无评论

Neuroscience & Medicine 2024年第1期15卷 39-50页

作者： Grass Aurelle Mambila Matsalou Jennifer Nyangui Mapaga Pupchen M. Gnigone Minka’a Pagbe Michael Chermine Mboumba Mboumba Christian Allognon Mahutondji Aissata Ibrahima Camara Annick A. Nsounda nelly Diouf Mbourou Michel-Arnaud Saphou-Damon Elsa Ayo Bivigou Philomene Kouna Ndouongo Neurology Department University Hospital of Libreville Libreville Gabon Cardiology Department University Hospitalof Libreville Libreville Gabon

Strokes are common around the world and especially in sub-Saharan Africa. They are responsible for severe sequelae and the majority of deaths. In Gabon, no study on stroke mortality has been conducted. Objective: To determine short, medium, long-term mortality and factors associated with long-term stroke mortality. Method: Our study took place in the Neurology Department of the University Hospital Center of Libreville (UHCL). It was a historical cohort study with descriptive and analytical purposes covering the period from June 1 to August 31, 2018 and taking into account hospitalized patients from January 1, 2013 to December 31, 2017. We conducted a comprehensive systematic recruitment of patients with stroke, 18 years old and more, and had been agreed to give information. We included all patients meeting the inclusion criteria. The data was gathered using Epi-Info 7 software. The CHI-2 test was used for the comparison of frequencies and the Student’s test, for comparison of means. Multivariate analysis with logistic regression allowed us to look for factors associated with long-term mortality. A result was statistically significant for a p 0.05 value. Results: At 3 months, 28 patients (18.1%) died, at 6 months thirty-one patients or 20.1% died. At 5 years old, fifty-three patients or 34.4% had died. The factors associated with long-term mortality, if the lost of sight were all alive were tobacco (p = 0.01) and stroke (p = 0.008). If all those who were lost to sight had died, no factor was associated with 5-year mortality. Conclusion: Stroke mortality must not be taken for granted, it can be underestimated because of the large number of lost sight. Measures must be put in place to strengthen post-stroke monitoring. .

关键词： Stroke Mortality Associated Factors Libreville