检索结果-南通市图书馆

Hepatitis B virus genotypes:an overview

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Hepatobiliary & Pancreatic Diseases International 2008年第5期7卷 457-464页

作者： Mamun-Al Mahtab Salimur rahman Mobin Khan Fazal Karim Department of Hepatology Bangabandhu Sheikh Mujib Medical UniversityDhaka Bangladesh

BACKGROUND:Hepatitis B virus(HBV)infection is a major cause of mortality and morbidity *** quest continues to identify viral factors that influence disease progression and severity as well as responses to treatment of HBV *** on variations in HBV,the virus has been divided into a number of genotypes. DATA SOURCES:Review of published literature on HBV genotypes. RESULTS:HBV genotypes are likely to be important in determining the severity and progression of HBV-induced liver disease as well as responses to different anti-viral agents. CONCLUSION:Although HBV genotyping is not yet recommended for routine use in treating HBV infection, available data suggest that,as in hepatitis C virus infection, HBV genotyping is also likely to become a routine investigation for HBV treatment,perhaps in the not too distant future.

关键词： hepatitis B virus genotype

维普期刊数据库

Impacts of Heat Flux Distribution, Sloping Magnetic Field and Magnetic Nanoparticles on the Natural Convective Flow Contained in a Square Cavity

在线全文

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2020年第3期16卷 441-463页

作者： Latifa M.Al-Balushi M.M.rahman Department of Mathematics College of ScienceSultan Qaboos UniversityMuscatOman

In the present paper,the effect of the heat flux distribution on the natural convective flow inside a square cavity in the presence of a sloping magnetic field and magnetic nanoparticles is explored *** nondimensional governing equations are solved in the framework of a finite element method implemented using the Galerkin *** role played by numerous model parameters in influencing the emerging thermal and concentration fields is examined;among them are:the location of the heat source and its lengthH,the magnitude of the thermal Rayleigh number,the nanoparticles shape and volume fraction,and the Hartmann *** is found that the nanofluid velocity becomes higher when the thermal source length,the nanoparticles volume fraction and/or the thermal Rayleigh number are increased,while it decreases as the Hartmann number Ha grows and the position of the heat source moves toward the center of the lower wall of the ***,the temperature of the nanofluid grows with the extension of the thermal source and decreases slowly when the heat flux position moves toward the center of the lower *** outcomes of the research also indicate that the average Nusselt number becomes smaller on increasing Hartmann number Ha and heat source length H^(*).The addition of Fe_(3)O_(4) to engine oil leads to a higher rate of heat transfer with respect to the addition of SiO_(2) ***-shaped nanoparticles generate the highest value of the Nusselt number compared to all the other considered shapes.

关键词： Nanofluids magnetic nanoparticles heat source natural convection finite element method square enclosure

The effect of replacing pnictogen elements on the physical properties of SrMg_2X_2(X=N,P,As,Sb,Bi) Zintl compounds

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第4期27卷 369-375页

作者： G Murtaza Abdul Ahad Khan M Yaseen A Laref Naeem Ullah Inayat ur rahman Materials Modelling Labortary Department of PhysicsIslamia College University Department of Physics University of the Peshawar Department of Physics University of AgricultureFaisalabad Department of Physics and Astronomy College of ScienceKing Saud University Department of Physics City University of Hong Kong

The effect of replacing the anion from N to Bi down the group in the periodic table is investigated on SrMg2X2（X = N,P,As,Sb,Bi）.A full potential linearized augmented plane wave plus local orbitals method is used along with different exchange–correlation potentials to obtain the lattice constants,phonons,electronic,and optical properties of the Sr Mg2X2（X = N,P,As,Sb,Bi） Zintl compounds.A good agreement is achieved and our calculations are validated by previous experimental and theoretical *** compounds have shown stable dynamical behavior with gamma centered longitudinal response having no imaginary *** band structures reveal the semiconducting nature of the *** Pnictogen（X）-p state contributed mainly in the valence band and the Sr-d state forms the conduction of the *** charge transfer and low overlapping of the atomic densities indicates the preferable ionic bonding character of these *** the optical properties,real and imaginary parts of dielectric function,complex refractive index,birefringence,reflectivity,and optical conductivity are *** compounds can be utilized in the optical and optoelectronic devices.

关键词： Zintl compounds band structure optical response

维普期刊数据库

Electrochemical performance of overlithiated Li1＋xNi0.8Co0.2O2： structural and oxidation state studies

在线全文

学校读者我要写书评

暂无评论

Frontiers of Materials Science 2015年第2期9卷 199-205页

作者： Roshidah RUSDI Norlida KAMARULZAMAN Kelimah ELONG Hashlina RUSDI Azilah ABD-rahman School of Physics and Materials Faculty of Applied Sciences Universiti Teknologi MARA 40450 Shah Alam Selangor Malaysia Centre for Nanomaterials Research Institute of Science Universiti Teknologi MARA 40450 Shah Alam Selangor Malaysia Centre for Foundation Studies in Science University of Malaya 50603 Kuala Lumpur Malaysia School of Chemistry and Environment Faculty of Applied Sciences Universiti Teknologi MARA 40450 Shah Alam Selangor Malaysia

Pure, layered compounds of overlithiated Li1＋xNi0.8Co0.2O2（x = 0.05 and 0.1） were successfully prepared by a modified combustion method. XRD studies showed that cell parameters of the material decreased with increasing the lithium content. SEM revealed that the morphology of particles changed from rounded polyhedral-like crystallites to sharp-edged polyhedral crystals with more doped lithium. EDX showed that the stoichiometries of Ni and Co agrees with calculated synthesized values. Electrochemical studies revealed the overlithiated samples have improved capacities as well as cycling behavior. The sample with x = 0.05 shows the best performance with a specific capacity of 113.29 mA.h.g-1 and the best capacity retention of 92.2% over 10 cycles. XPS results showed that the binding energy of Li ls is decreased for the Li doped samples with the smallest value for the x = 0.05 sample, implying that Li＋ ions can be extracted more easily from Li1.05Ni0.8Co0.2O2 than the other stoichiometries accounting for the improved performance of the material. Considerations of core level XPS peaks for transition metals reveal the existence in several oxidation states. However, the percentage of the＋3 oxidation state of transition metals for the when x = 0.1 is the highest and the availability for charge transition from the ＋3 to＋4 state of the transition metal during deintercalation is more readily available.

关键词： overlithiation LiNio.8Coo.202 interstitial doped Li1.05Ni0.8Co0.2O2 Li1.1Ni0.8Co0.2O2

Deep reinforcement learning based computation offloading and resource allocation for low-latency fog radio access networks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Intelligent and Converged Networks 2020年第3期1卷 243-257页

作者： G.M.Shafiqur rahman Tian Dang Manzoor Ahmed Key Laboratory of Universal Wireless Communications(Ministry of Education) Beijing University of Posts and TelecommunicationsBeijing 100876China

Fog Radio Access Networks(F-RANs)have been considered a groundbreaking technique to support the services of Internet of Things by leveraging edge caching and edge ***,the current contributions in computation offloading and resource allocation are inefficient;moreover,they merely consider the static communication mode,and the increasing demand for low latency services and high throughput poses tremendous challenges in F-RANs.A joint problem of mode selection,resource allocation,and power allocation is formulated to minimize latency under various *** propose a Deep Reinforcement Learning(DRL)based joint computation offloading and resource allocation scheme that achieves a suboptimal solution in *** core idea of the proposal is that the DRL controller intelligently decides whether to process the generated computation task locally at the device level or offload the task to a fog access point or cloud server and allocates an optimal amount of computation and power resources on the basis of the serving *** results show that the proposed approach significantly minimizes latency and increases throughput in the system.

关键词： fog radio access networks computation offloading mode selection resource allocation distributed computation low latency deep reinforcement learning

An efficient hybrid system for anomaly detection in social networks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cybersecurity 2021年第1期4卷 136-146页

作者： Md.Shafiur rahman Sajal Halder MdAshraf Uddin Uzzal Kumar Acharjee Department of Computer Science and Engineering Dhaka International UniversityDhakaBangladesh Department of Computer Science and Engineering Jagannath UniversityDhakaBangladesh Department Computer Science and Information Technology RMIT UniversityMelbourneAustralia Internet Commerce Security Laboratory Federation University AustraliaBallarat VIC 3350Australia

Anomaly detection has been an essential and dynamic research area in the data mining.A wide range of applications including different social medias have adopted different state-of-the-art methods to identify anomaly for ensuring user’s security and *** social network refers to a forum used by different groups of people to express their thoughts,communicate with each other,and share the content *** social networks also facilitate abnormal activities,spread fake news,rumours,misinformation,unsolicited messages,and propaganda post malicious ***,detection of abnormalities is one of the important data analysis activities for the identification of normal or abnormal users on the social *** this paper,we have developed a hybrid anomaly detection method named DT-SVMNB that cascades several machine learning algorithms including decision tree(C5.0),Support Vector Machine(SVM)and Naïve Bayesian classifier(NBC)for classifying normal and abnormal users in social *** have extracted a list of unique features derived from users’profile and *** two kinds of dataset with the selected features,the proposed machine learning model called DT-SVMNB is *** model classifies users as depressed one or suicidal one in the social *** have conducted an experiment of our model using synthetic and real datasets from social *** performance analysis demonstrates around 98%accuracy which proves the effectiveness and efficiency of our proposed system.

关键词： Anomaly Detection Machine Learning Hybrid Anomaly Detection Social Networks

In situ growth of single-crystal TiO2 nanorod arrays on Ti substrate： Controllable synthesis and photoelectro- chemical water splitting

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2017年第3期10卷 1021-1032页

作者： Tingting Zhang Zia Ur rahman Ning Wei Yupeng Liu Jun Liang Daoai Wang State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy ofSciences Lanzhou 730000 China University of Chinese Academy of Sciences Beijing 100049 China Qingdao Center for Resource Chemistry and New Materials Qingdao 266100 China

Despite one-dimensional （1D） semiconductor nanostructure arrays attracting increasing attention due to their many advantages, highly ordered TiO2 nanorod arrays （TiO2 NR） are rarely grown in situ on Ti substrates. Herein, a feasible method to fabricate TiO2 NRs on Ti substrates by using a through-mask anodization process is reported. Self-ordered anodic aluminum oxide （AAO） overlaid on Ti substrate was used as a nanotemplate to induce the growth of TiO2 NRs. The NR length and diameter could be controlled by adjusting anodization parameters such as electrochemical anodization voltage, anodization time and temperature, and electrolyte composition. Furthermore, according to the proposed NR formation mechanism, the anodized Ti ions migrate and deposit in the AAO nanochannels to form Ti（OH）4 or amorphous TiO2 NRs under electric field, owing to the confinement effect of the template. Photoelectrochemical tests indicated that, after hydrogenation, the TiO2 NRs presented higher photocurrent density under simulated sunlight and visible light illuminations, suggesting their potential use in photoelectrochemical water splitting, photocatalysis, solar cells, and sensors.

关键词： hydrogenation TiO2 nanorod arrays in situ preparation through-hole anodic alu-minum oxide (AAO) mask photoelectrochemical

Bilirubin sensor based on CuO-CdO composites deposited in a nafion/glassy carbon electrode matrixes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2017年第5期27卷 566-573页

作者： Mohammed M.rahman Mohammad Musarraf Hussain Abdullah M.Asiri Chemistry Department King Abdulaziz UniversityFaculty of Science Center of Excellence for Advanced Material Research (CEAMR) King Abdulaziz University

Copper oxide-cadmium oxide nanocomposites(CuO-CdO NCs) were synthesized by solvothermal technique in a basic medium. CuO-CdO NCs were characterized using conventional techniques, such as Fourier Transform Infrared Spectroscopy(FTIR), UV–Visible Spectroscopy(UV/Vis), Field-Emission Scanning Electron Microscopy(FESEM), X-ray electron dispersive spectroscopy(XEDS), X-ray photoelectron spectroscopy(XPS), and powder X-ray diffraction(XRD). A selective and enzyme-less Bilirubin(BLR) sensor was developed with a thin-layer of NCs onto a glassy carbon electrode(GCE, surface area = 0.0316 cm~2) using 5% nafion binders at room conditions. Improved electrochemical performances of higher sensitivity, lower detection limit,linear dynamic range(LDR), and long-term stability of preferred BLR were achieved by a reliable currentvoltage(I-V) approach. The calibration curve was found linear(R~2= 0.9347) in a wide range of BLR concentration(10.0 pM ~ 10.0 mM). Based on the signal to noise ratio value of 3, the sensitivity and limit of detection(LOD) of the sensor were calculated as 95.0 pA μM-1cm-2and 1.0 ± 0.1 pM *** synthesized CuO-CdO NCs/GCE is an excellent advancement of developing a selective and sensitive BLR sensor by electrochemical approach and practically implemented in real sample applications.

关键词： CuO-CdO nanocomposites Bilirubin biosensor Glassy carbon electrode Sensitivity Real sample analysis Health care field

Melting phenomenon in magneto hydro-dynamics steady flow and heat transfer over a moving surface in the presence of thermal radiation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2013年第3期22卷 57-62页

作者： Reda G.Abdel-rahman M.M.Khader Ahmed M.Megahed Department of Mathematics Faculty of ScienceBenha University

The Lie group method is applied to present an analysis of the magneto hydro-dynamics（MHD） steady laminar flow and the heat transfer from a warm laminar liquid flow to a melting moving surface in the presence of thermal *** using the Lie group method,we have presented the transformation groups for the problem apart from the scaling *** application of this method reduces the partial differential equations（PDEs） with their boundary conditions governing the flow and heat transfer to a system of nonlinear ordinary differential equations（ODEs） with appropriate boundary *** resulting nonlinear system of ODEs is solved numerically using the implicit finite difference method（FDM）.The local skin-friction coefficients and the local Nusselt numbers for different physical parameters are presented in a table.

关键词： Lie group method magneto hydro-dynamics melting phenomenon Newtonian fluid radiation

维普期刊数据库