检索结果-南通市图书馆

Spectroscopic Electrochemical Properties and DFT Calculation of 1-Aryltriazenes

International Journal of Organic Chemistry 2023年第4期13卷 109-128页

作者： Insa Seck Mohamed Lamine Sall atoumane ndiaye Samba Fama Ndoye Lalla Aïcha Ba Matar Seck Organic Chemistry Coordination Laboratory Cheikh Anta Diop University of Dakar Dakar-Fann Senegal Organic Chemistry and Therapeutic Chemistry Laboratory Cheikh Anta Diop University of Dakar Dakar-Fann Senegal Organic Physical Chemistry and Environmental Analysis Laboratory Cheikh Anta Diop University of Dakar Dakar-Fann Senegal Department of Physics Cheikh Anta Diop University of Dakar Dakar-Fann Senegal Amadou Mahtar Mbow University Dakar Nafa VDN Senegal

Electrochromic materials are of great interest for their potential in eyewear protection and data storage devices, as they change colors in response to electrochemical switching. While many of the systems currently used are based on inorganic materials, organic materials such as triazenes have emerged as viable alternatives due to their unique properties, including optical properties. Triazenes are a class of organic compounds with three consecutive nitrogen atoms in an acyclic arrangement, and they have been used for a variety of applications in medicinal and synthetic chemistry. However, the effects of solvents on the UV-visible absorption spectrum of triazenes have not been fully investigated. The neutral molecules of 3,3-diisopropyl-1-phenyltriazene and 1-(4-chlorophenyl)-3-cyclopentyltriazene in acetonitrile, the UV-visible spectra corresponded respectively to HOMO → LUMO transitions with a large maximum absorption at 299.74 nm (4.1364 eV) and 299.57 nm (4.1387 eV) and the most intense oscillator strength (f = 0.6988) and (f = 0.7372). These results suggest that the electronic transitions of the compounds are highly influenced by the nature of the substituents on the triazene unit, as well as the solvent used in the experiment. The redox couple 0.92 and -0.44 V/Ag/AgCl is attributed to the phenyl group. Compound III showed an oxidation and reduction peak respectively -0.27 and -0.8 V/Ag/AgCl attributed to the phenyl molecule. The study concluded that all three compounds were electroactive and exhibited reversible characteristics with oxidizing/reducing couples. This study aims to contribute to research on the optical properties of triazenes compounds and the application of quantum chemical calculation methods for understanding their molecular structures. By investigating the solute-solvent interactions occurring in the solvation shell of the solutes, we aim to gain insights into the effects of solvents on the UV-visible absorption spectrum of triazenes. Our fin

关键词： Triazenes UV-Visible Spectroscopy Electrochemical DFT Calculations

来源：

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

Spectroscopic Electrochemical Properties and DFT Calculation of 1-Aryltriazenes

引用

International Journal of Organic Chemistry（有机化学国际期刊） 2023年第4期

作者： Insa Seck Mohamed Lamine Sall atoumane ndiaye Samba Fama Ndoye Lalla Aïcha Ba Matar Seck

来源：博看期刊评论

在线全文

博看期刊

学校读者我要写书评

暂无评论

ADEFGuard:Anomaly detection framework based on Ethereum smart contracts behaviours

引用

Blockchain(Research and Applications) 2023年第3期4卷 88-97页

作者： Malaw ndiaye Thierno Ahmadou Diallo Karim Konate Computer Science Department UCAD DakarSenegal Computer Science Department UASZ ZiguinchorSenegal

Smart contracts are the building blocks of blockchain systems that enable automated peer-to-peer transactions and decentralized *** contracts certainly provide a powerful functional surplus for maintaining the consistency of transactions in applications governed by blockchain *** contracts have become lucrative and profitable targets for attackers because they can hold a large amount of *** verification and symbolic analysis have been employed to combat these destructive scams by analysing the codes and function calls,yet each scam's vulnerability should be discreetly *** this work,we introduce ADEFGuard,a new anomaly detection framework based on the behaviour of smart contracts,as a new *** design a learning and monitoring module to determine fraudulent smart contract *** framework is advantageous over basic algorithms in three ***,ADEFGuard provides a unified solution to different genres of scams,relieving the need for code analysis ***,ADEFGuard's inference is orders of magnitude faster than code ***,the experimental results show that ADEFGuard achieves high accuracy(85%),precision(75%),and recall(90%)for malicious contracts and is potentially useful in detecting new malicious behaviours of smart contracts.

关键词： Blockchain Smart contract Security Anomaly

来源：

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

Numerical Approach of Network Problems in Optimal Mass Transportation

引用

Applied Mathematics 2012年第5期3卷 457-466页

作者： Lamine ndiaye Babacar Mbaye ndiaye Pierre Mendy Diaraf Seck Laboratory of Mathematics of Decision and Numerical Analysis (LMDAN) FASEG University of Cheikh Anta Diop Dakar Senegal Unité Mixte Internationale UMMISCO Institut de Recherche pour le Développement Bondy France

In this paper, we focus on the theoretical and numerical aspects of network problems. For an illustration, we consider the urban traffic problems. And our effort is concentrated on the numerical questions to locate the optimal network in a given domain (for example a town). Mainly, our aim is to find the network so as the distance between the population position and the network is minimized. Another problem that we are interested is to give an numerical approach of the Monge and Kantorovitch problems. In the literature, many formulations (see for example [1-4]) have not yet practical applications which deal with the permutation of points. Let us mention interesting numerical works due to E. Oudet begun since at least in 2002. He used genetic algorithms to identify optimal network (see [5]). In this paper we introduce a new reformulation of the problem by introducing permutations . And some examples, based on realistic scenarios, are solved.

关键词： Optimal Mass Transportation Network Urban Traffic Monge-Kantorovich Problem Global Optimization

来源：

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

Compressive Myeloradiculopathies in Multiple Myeloma: Clinical and Radiological Characteristics of a Series of 29 Patients

引用

Open Journal of Blood Diseases 2021年第4期11卷 133-139页

作者： El Hadji Daouda Niang Mbodji Ahmadou Bamba Ka Mamadou Fall Seynabou Seck Moussa Mbaye Khalifa Ababacar Bousso Elimane Sarr Khadim Faye atoumane ndiaye Fatou Samba Diago ndiaye Moustapha Diop Saliou Department of Haematology Cheikh Anta Diop University Dakar Senegal Department of Neurology Cheikh Anta Diop University Dakar Senegal Internal Medicine Service Aristide Le Dantec Hospital Cheikh Anta Diop University Dakar Senegal

Introduction: Patients with multiple myeloma (MM) develop neurological complications such as root and/or spinal cord compression in at least 5% of cases. The aim of this work is to describe the clinical and radiological features of root and/or spinal cord compression occurring during multiple myeloma. Patients and Methods: We conducted a retrospective study in the Clinical Haematology Department of Dalal Jamm Hospital and the National Blood Transfusion Centre, the Neurological Clinic of Fann Hospital Centre and the Internal Medicine Department of Aristide Le Dantec Hospital in Dakar between January 2016 and December 2019. All patients whose multiple myeloma diagnosis was established according to the International Myeloma Working Group’s 2014 and who had root, spinal or myeloradicular compression, were included in our study. Results: A total of 29 patients were included. The average age was 54.31 years [32 - 76 years]. The sex ratio (M/F) was 1.6. Motor deficits were the reason for consultation in 68% of the patients and spinal pains were reported by 93% of the patients. Neurological signs revealed multiple myeloma in all our patients. 25 patients (86.2%) had paraplegia and 1 patient had tetraparesis. Hypoesthesia to a defined sensory level was noted in 8 patients (28%). 5 patients (17.24%) had sphincter disorders. The types of lesions showed by imaging were vertebral lysis in 100% of cases, vertebral compression in 37% of cases, and epidural infiltration in 34% of cases. 12 patients (41.37%) had spinal compression, 14 patients (48.27%) had

关键词： Multiple Myeloma Spinal Cord Compression Root Compression Bone Lesions

来源：

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

Grazing effects on vegetation dynamics in the savannah ecosystems of the Sahel

引用

Ecological Processes 2023年第1期12卷 752-763页

作者： Haftay Hailu Gebremedhn Ousmane ndiaye Sylvanus Mensah Cofélas Fassinou Simon Taugourdeau Torbern Tagesson Paulo Salgado African Center of Excellence for Climate-Smart Agriculture and Biodiversity Conservation Haramaya UniversityP.O.Box 138Dire DawaEthiopia Dispositif en Partenariat«Pôle Pastoralisme Et Zones Sèches» Route du Front de Terre BP 2057Pôle de Recherche de HannISRADakarSenegal Centre de Recherches Zootechniques de Dahra Institut Sénégalais de Recherches AgricolesDakarSenegal Laboratoire de Biomathématiques et d’Estimations Forestières Facultédes Sciences AgronomiquesUniversitéd’Abomey-CalaviCotonouBenin Chair of Forest Growth and Dendroecology Albert-Ludwigs-Universität FreiburgFreiburg Im BreisgauGermany Facultédes Sciences et Techniques Département BVUniversitéCheikh-Anta-DiopDakarSenegal UMR SELMET CIRADINRAEInstitut Agro Univ MontpellierMontpellierFrance Department of Physical Geography and Ecosystem Science Lund UniversitySölvegatan 1222362 LundSweden Department of Geosciences and Natural Resource Management University of CopenhagenØster Voldgade 101350 CopenhagenDenmark

Background The savannah ecosystems of Sahel have experienced continuous and heavy grazing of livestock for centuries but still,their vegetation response to grazing pressure remains poorly *** this study,we analysed the herbaceous plant dynamics,measured by species diversity,composition,cover,and biomass in response to grazing pressure in the savannah ecosystems of *** Senegal,we selected four savannah sites represented with high,moderate,light and no grazing intensity *** survey methods were used for sampling the vegetation data within each of the *** richness and composition were analysed using species accumulation curve and multivariate ***,we used General Linear Models and a piecewise Structural Equation Model(pSEM)to examine the relationships between grazing intensity,vegetation cover,diversity and *** The herbaceous species diversity and composition varied significantly among the different grazing intensity levels(p<0.001).The plant species composition shifted from the dominance of grass cover to the dominance of forb cover with increasing grazing ***,the attributes of species diversity,herbaceous biomass,and ground cover were higher on sites with low grazing than sites with high and moderate grazing *** all sites,species diversity was positively related to total *** pSEM explained 37%of the variance in total biomass and revealed that grazing intensity negatively influenced total biomass both directly and indirectly through its negative influence on species *** Managing grazing intensity may lead to higher plant production and higher mixed forage establishment in the dryland savannah *** information can be used to support land management strategies and promote sustainable grazing practices that balance the needs of livestock with the conservation of ecosystem health and biodiversity.

关键词： Biomass Biodiversity Diodella sarmentosa Forb Grazing intensity Invasive species Pastoral ecosystem Senegal West Africa

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Modeling of the Photovoltaic Module Operating Temperature for Various Weather Conditions in the Tropical Region

引用

Fluid Dynamics & Materials Processing 2022年第5期18卷 1275-1284页

作者： Mame Cheikh Diouf Mactar Faye Ababacar Thiam Alphousseyni ndiaye Vincent Sambou Efficiency and Energetic Systems Research Group Alioune Diop UniversityBambeySenegal Laboratoire Eau EnergieEnvironnement et Procédés Industriels(LE3PI)UniversitéCheikh Anta DiopBambeySenegal

The operating temperature is a critical factor affecting the performances of photovoltaic(PV)*** this work,relevant models are proposed for the prediction of this operating temperature using data(ambient temperature and solar irradiance)based on real measurements conducted in the tropical *** each weather condition(categorized according to irradiance and temperature levels),the temperatures of the PV modules obtained using the proposed approach is compared with the corresponding experimentally measured *** results show that the proposed models have a smaller Root Mean Squared Error than other models developed in the literature for all weather conditions,which confirms the reliability of the proposed framework.

关键词： Photovoltaic operating temperature PV module weather condition

来源：

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

Laplace Transform, Non-Constant Coefficients Differential Equations and Applications to Riccati Equation

引用

Applied Mathematics 2020年第7期11卷 639-649页

作者： Malick ndiaye Mathematics and Computer Sciences Department at Marist College Poughkeepsie NY USA

In this paper, the Laplace Transform is used to find explicit solutions of a fam-ily of second order Differential Equations with non-constant coefficients. For some of these equations, it is possible to find the solutions using standard tech-niques of solving Ordinary Differential Equations. For others, it seems to be very difficult indeed impossible to find explicit solutions using traditional methods. The Laplace transform could be an alternative way. An application on solving a Riccati Equation is given. Recall that the Riccati Equation is a non-linear differential equation that arises in many topics of Quantum Me-chanics and Physics.

关键词： Ordinary Differential Equations Laplace Transform

来源：

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

Matrix Riccati Equations in Optimal Control

引用

Applied Mathematics 2024年第3期15卷 199-213页

作者： Malick ndiaye School of Computer Sciences and Mathematics Marist College Poughkeepsie USA

In this paper, the matrix Riccati equation is considered. There is no general way for solving the matrix Riccati equation despite the many fields to which it applies. While scalar Riccati equation has been studied thoroughly, matrix Riccati equation of which scalar Riccati equations is a particular case, is much less investigated. This article proposes a change of variable that allows to find explicit solution of the Matrix Riccati equation. We then apply this solution to Optimal Control.

关键词： Optimal Control Matrix Riccati Equation Change of Variable

来源：

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

Origin of Sexy Prime Numbers, Origin of Cousin Prime Numbers, Equations from Supposedly Prime Numbers, Origin of the Mersenne Number, Origin of the Fermat Number

引用

Advances in Pure Mathematics 2024年第5期14卷 321-332页

作者： Mady ndiaye Middle School Badara Mbaye Kaba Dakar Academy Inspection Ministry of National Education of Senegal Dakar Senegal

We have found through calculations that the differences between the closest supposed prime numbers other than 2 and 3 defined in the articles are: 2;4: and 6. For those whose difference is equal to 6, we showed their origin then we classified them into two categories according to their classes, we showed in which context two prime numbers which differ from 6 are called sexy and in what context they are said real sexy prime. For those whose difference is equal to 4, we showed their origin then we showed that two prime numbers which differ from 4, that is to say two cousin prime numbers, are successive. We made an observation on the supposed prime numbers then we established two pairs of equations from this observation and deduced the origin of the Mersenne number and that of the Fermat number.

关键词： Cousin Prime Numbers Sexy Prime Numbers Real Sexy Prime Numbers Equations from Supposed Prime Numbers Mersenne Number Fermat Number Supposed Prime Numbers Prime Numbers

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：