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Post-synthetic metalation of organic cage for enhanced porosity and catalytic performance

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Science China Chemistry 2023年第6期66卷 1763-1770页

作者： Miao Yang Xun Chen Yifei Xie El-sayed mel-sayed Ning Xu Wenjing Wang Kongzhao Su Daqiang Yuan State Key Lab of Structure Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of the Chinese Academy of Sciences Beijing 100049China College of Chemistry Fuzhou UniversityFuzhou 310116China Chemical Refining Laboratory Refining DepartmentEgyptian Petroleum Research InstituteNasr City 11727Egypt

Porous organic cages(POCs)have shown great potential in many applications,and post-synthetic modification(PSM)has been confirmed to be an effective strategy to tailor their structures and related ***,it is extremely challenging to develop a general platform for simple-to-make functional POCs for advanced applications by PSM ***,we reported that octahedral calix[4]resorcinarene-based hydrazone-linked porous organic cage(HPOC-401)provides an excellent platform for post-synthetic metalation by various transition metal(TM)ions under mild conditions due to the abundance of coordination sites in its *** metalated products(HPOC-401-TM)exhibit Brunauer-Emmett-Teller(BET)surface area up to1,456 m^(2)g^(-1),much higher than that of the pristine HPOC-401,which has a BET value of 474 m^(2)g^(-1).Moreover,the metalation and porosity increases further influence their gas capture,separation,as well as catalytic *** instance,HPOC-401-TM products exhibit higher CO_(2),H_(2),and C2 hydrocarbon gas uptake,as well as higher C_(2)H_(6)/C_(2)H_(4) selectivity than ***,the HPOC-401-TM also shows better catalytic performance in the cycloaddition of CO_(2) with epoxides compared to *** findings uncover a simple yet effective approach for modifying the porosity characteristics of organic cages,which will undoubtedly expand their future implementations.

关键词： porous organic cage(POC) calixresorcinarene post-synthetic metalation(PSM) gas adsorption and separation CO_(2)cycloaddition

Robust Giant Octahedral[6+8]Porous Organic Cages for Efficient Ethylene/Ethane Separation

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CCS Chemistry 2024年第9期6卷 2264-2274页

作者： Lijuan Feng Yan-Xi Tan El-sayed mel-sayed Fenglei Qiu Wenjing Wang Kongzhao Su Daqiang Yuan State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002 College of Chemistry Fuzhou UniversityFuzhou 350116 Chemical Refining Laboratory Refining Department Egyptian Petroleum Research InstituteNasr CityCairo 11727 University of the Chinese Academy of Sciences Beijing 100049 Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108

The exploration of ethane(C_(2)H_(6))-selective porous materials for the direct production of polymer-grade ethylene(C_(2)H_(4))from a C_(2)H_(6)/C_(2)H_(4) mixture in a single energy-saving adsorption step is of utmost importance but remains a significant ***,developing robust C_(2)H_(6)-selective adsorbents with high C_(2)H_(6) capacity and C_(2)H_(6)/C_(2)H_(4) selectivity is urgently needed for industrial *** this study,we have successfully designed and synthesized two novel calix[4]resorcinarene-based porous organic cages(POCs)named CPOC-501 and *** POCs were formed via a Schiff-base reaction involving face-directed[6+8]condensation between a bowlshaped tetratopic tetraformylcalix[4]resorcinarene and triangular tritopic amine *** using single crystal X-ray crystallography revealed that both cages possess large truncated octahedral cavities with a volume of approximately 6500Å3 and 12 accessible rhombic windows with a side length of approximately 10.5Å.Furthermore,the cages exhibited excellent chemical stability under neutral,acidic,and basic conditions and high Brunauer–Emmett–Teller specific surface areas of up to 2175 m^(2) g^(−1) after *** POCs demonstrated superior adsorption capabilities for C_(2)H_(6) over C_(2)H_(4).Notably,CPOC-502 exhibited a C_(2)H_(6) capacity and C_(2)H_(6)/C_(2)H_(4) selectivity of 83 cm^(3) g^(−1) and 2.83,respectively,surpassing most of the best-performing C_(2)H_(6)-selective porous organic materials reported to ***,breakthrough experiments confirmed that both cages efficiently produced polymer-grade C_(2)H_(4)(>99.9%)directly from the C_(2)H_(6)/C_(2)H_(4) mixture,highlighting their outstanding recyclability.

关键词： C_(2)H_(6)/C_(2)H_(4)separation porous organic cages calixresorcinarene gas adsorption and separation host-guest interactions

Tunable Cage-Based Three- Dimensional Covalent Organic Frameworks

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CCS Chemistry 2022年第9期4卷 3095-3105页

作者： Chunqing Ji Kongzhao Su Wenjing Wang Jianhong Chang El-sayed mel-sayed Lei Zhang Daqiang Yuan State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002 University of the Chinese Academy of Sciences Beijing 100049 State Key Laboratory of Inorganic Synthesis and Preparative Chemistry Jilin UniversityChangchun 130012 Chemical Refining Laboratory Refining DepartmentEgyptian Petroleum Research InstituteNasr City 11727 College of Materials Science and Engineering Fujian University of TechnologyFuzhou 350118 Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350002

It is extremely challenging to construct three-dimensional(3D)crystalline covalent organic frameworks(COFs)with flexible building blocks and to further explore their tunable or adaptive characteristics due to crystallization and structure determination ***,we constructed three crystalline isostructural 3D-OC-COFs based on a newly synthesized flexible organic cage(6NH_(2)-OC.4HCl)through a novel in situ acid–base neutralization strategy.

关键词： organic cages covalent organic frameworks tunable gas adsorption and separation breakthrough experiment

Efficient Deep-Learning-Based Autoencoder Denoising Approach for Medical Image Diagnosis

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Computers, Materials & Continua 2022年第3期70卷 6107-6125页

作者： Walid El-Shafai Samy Abd El-Nabi El-sayed mel-Rabaie Anas M.Ali Naglaa F.Soliman Abeer D.Algarni Fathi E.Abd El-Samie Department of Electronics and Electrical Communications Faculty of Electronic EngineeringMenoufia UniversityMenouf32952Egypt Alexandria Higher Institute of Engineering&Technology(AIET) AlexandriaEgypt Department of Information Technology College of Computer and Information SciencesPrincess Nourah Bint Abdulrahman UniversityRiyadh84428Saudi Arabia

Effective medical diagnosis is dramatically expensive,especially in third-world *** of the common diseases is pneumonia,and because of the remarkable similarity between its types and the limited number of medical images for recent diseases related to pneumonia,themedical diagnosis of these diseases is a significant ***,transfer learning represents a promising solution in transferring knowledge from generic tasks to specific ***,experimentation and utilization of different models of transfer learning do not achieve satisfactory *** this study,we suggest the implementation of an automatic detectionmodel,namelyCADTra,to efficiently diagnose pneumonia-related *** model is based on classification,denoising autoencoder,and transfer ***,pre-processing is employed to prepare the medical *** depends on an autoencoder denoising(AD)algorithm with a modified loss function depending on a Gaussian distribution for decoder output to maximize the chances for recovering inputs and clearly demonstrate their features,in order to improve the diagnosis ***,classification is performed using a transfer learning model and a four-layer convolution neural network(FCNN)to detect *** proposed model supports binary classification of chest computed tomography(CT)images and multi-class classification of chest X-ray ***,a comparative study is introduced for the classification performance with and without the denoising *** proposed model achieves precisions of 98%and 99%for binary classification and multi-class classification,respectively,with the different ratios for training and *** demonstrate the efficiency and superiority of the proposed CADTra model,it is compared with some recent state-of-the-art CNN *** achieved outcomes prove that the suggested model can help radiologists to detect pneumonia-related diseases and improve the diagnostic efficiency compared to the exis

关键词： Medical images CADTra AD CT and X-ray images autoencoder

Sanitary Quality of the Meals Served in the Canteens and Vicinity of the Lagoon Mother and Child University Hospital Centre and National Hospital and University Centre Hubert Koutoukou Maga of Cotonou (Benin)

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Open Journal of Preventive Medicine 2023年第5期13卷 183-197页

作者： Moussiliou Paraïso Cyriaque Comlan Degbey yasmine Bakary Ozavino Colette Azandjeme Charles Sossa-Jerome Regional Institute of Public Health University of Abomey-Calavi Abomey-Calavi Benin

Background: Food safety is an integral part of food security. It refers to the protection of the food supply against risks of microbial, chemical and physical origin at every stage of the food chain. The study aimed to investigate the sanitary quality of meals served in the canteens and vicinity of the Lagoon Mother and Child University Hospital Centre (CHU-mel) and National Hospital and University Centre Hubert Koutoukou Maga (CNHU-HKM) of Cotonou. Methods: It was a cross-sectional with a data collection period from 16 March to 22 April 2021. There were 32 vendors surveyed and 40 meals sampled for microbiological examination. We collected data on the vendors’ socio-demographic characteristics, working environment, health status, knowledge and food hygiene practices. Results: About 83% of the meals contained pathogenic microorganisms. All meals had a temperature from 4°C to 60°C called the “danger zone”. The level of knowledge about food hygiene was low in 65.7% of the vendors. About 47% had poor personal and clothing hygiene, food storage and service practices. Conclusion: These results show that the meals sold in the CHU-mel and CNHU-HKM could present a health risk for the consumer. There is a need for improvement of the sanitary quality of the meals delivered in the canteens and vicinity of these hospitals.

关键词： Sanitary Quality Meals Canteens CHU-mel CNHU-HKM Benin

Blind Modulation Recognition in Wireless MC-CDMA Systems Using a Support Vector Machine Classifier

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Wireless Engineering and Technology 2013年第3期4卷 145-153页

作者： Mohamed El-Hady Magdy Keshk Keshk El-sayed Elrabie Fathi El-sayed Abd El-Samie Mohammed Abd El-Naby Egyptian Space Program National Authority for Remote Sensing and Space Science Cairo Egypt Faculty of Electronic Engineering Menoufia University Menouf Egypt.

Automatic Digital Modulation Recognition (ADMR) is becoming an interesting problem with various civil and military applications. In this paper, an ADMR algorithm in Multi-Carrier Code Division Multiple Access (MC-CDMA) systems using Discrete Transforms (DTs) and mel-Frequency Cepstral Coefficients (MFCCs) is proposed. This algorithm uses various DT techniques such as the Discrete Wavelet Transform (DWT), Discrete Cosine Transform (DCT) and Discrete Sine Transform (DST) with MFCCs to extract features from the modulated signal and a Support Vector Machine (SVM) to classify the modulation orders. The proposed algorithm avoids over fitting and local optimal problems that appear in Artificial Neural Networks (ANNs). Simulation results shows the classifier is capable of recognizing the modulation scheme with high accuracy up to 90% - 100% using DWT, DCT and DST for some modulation schemes over a wide Signal-to-Noise Ratio (SNR) range in the presence of Additive White Gaussian Noise (AWGN) and Rayleigh fading channel, particularly at a low Signal-to-Noise ratios (SNRs).

关键词： ADMR MC-CDMA MFCC DT SVM ANN

Stand-Alone Intelligent Voice Recognition System

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Journal of Signal and Information Processing 2014年第4期5卷 179-190页

作者： Mohammed R. Saady Hatem El-Borey El-sayed A. El-Dahshan Ashraf Shamseldin Yahia Basic Science Department Faculty of Computers and Information Fayoum University El Fayoum Egypt Physics Department Faculty of Science Ain Shames University Cairo Egypt Egyptian E-Learning University Elmesaha El-Doki Giza Egypt

In this paper, an expert system for security based on biometric human features that can be obtained without any contact with the registering sensor is presented. These features are extracted from human’s voice, so the system is called Voice Recognition System (VRS). The proposed system?consists of a combination of three stages: signal pre-processing, features extraction by using?Wavelet Packet Transform (WPT) and features matching by using Artificial Neural Networks (ANNs). The features vectors are formed after two steps: firstly, decomposing the speech signal at level 7 with Daubechies 20-tap (db20), secondly, the energy corresponding to each WPT node is calculated which collected to form a features vector. One hundred twenty eight features vector for each speaker was fed to the Feed Forward Back-propagation Neural Network (FFBPNN). The data used in this paper are drawn from the English Language Speech Database for Speaker Recognition (ELSDSR) database which composes of audio files for training and other files for testing. The performance of the proposed system is evaluated by using the test files. Our results showed that the rate of correct recognition of the proposed system is about 100% for training files and 95.7% for one testing file for each speaker from the ELSDSR database. The proposed method showed efficiency results were better than the well-known mel Frequency Cepstral Coefficient (MFCC) and the Zak transform.

关键词： Voice Recognition Wavelet Packet Transform Feature Extraction Artificial Neural Network