检索结果-南通市图书馆

Mass spectra of Heavy and Light Mesons Using Asymptotic Iteration Method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2018年第8期69卷 179-184页

作者： Richa Rani s.B.Bhardwaj Fakir ChAND Department of Physics Kurukshetra University

The non-relativistic radial schr¨odinger equation is analytically solved using asymptotic iteration method within the framework of a general interaction potential whose special cases are the Cornell and Cornell plus harmonic potentials. The energy eigenvalues expression is derived in three dimensional space, which is further used to calculate the mass spectra of ˉcc,ˉbb,ˉbc, cˉs, bˉs and b ˉq mesons. The obtained results of this work are in good agreement with experimental and other relativistic results and also improved in comparison with other non-relativistic recent studies.

关键词： schrodinger equation asymptotic iteration method mass spectra mesons

Progressive Transfer Learning-based Deep Q Network for DDOs Defence in WsN

在线全文

学校读者我要写书评

暂无评论

Computer systems science & Engineering 2023年第3期44卷 2379-2394页

作者： s.Rameshkumar R.Ganesan A.Merline Department of Electronics and Communication Engineering Sethu Institute of TechnologyVirudhunagarTamilnaduIndia Department of Electrical and Electronics Engineering E.G.S.Pillay Engineering collegeNagapattinamTamilnaduIndia

In The Wireless Multimedia sensor Network(WNsMs)have achieved popularity among diverse communities as a result of technological breakthroughs in sensor and current *** utilising portable technologies,it achieves solid and significant results in wireless communication,media transfer,and digital *** nodes have been used in agriculture and industry to detect characteristics such as temperature,moisture content,and other environmental conditions in recent *** have also made apps easier to use by giving devices self-governing access to send and process data connected with appro-priate audio and video *** video sensor network studies focus on lowering power consumption and increasing transmission capacity,but the main demand is data *** of the obstacles in the sensor nodes,WMsN is subjected to a variety of attacks,including Denial of service(Dos)*** Convolutional Neural Network is designed with the stateaction relationship mapping which is used to identify the DDOs Attackers present in the Wireless sensor Networks for smart *** Proposed work it performs the data collection about the traffic conditions and identifies the deviation between the network conditions such as packet loss due to network congestion and the presence of attackers in the *** reduces the attacker detection delay and improves the detection *** order to protect the network against Dos assaults,an improved machine learning technique must be *** efficient Deep Neural Network approach is provided for detecting Dos in *** required parameters are selected using an adaptive particle swarm optimization *** ratio of packet transmission,energy consumption,latency,network length,and throughput will be used to evaluate the approach’s efficiency.

关键词： DOs attack wireless sensor networks for smart agriculture deep neural network machine learning technique

Zubair Lomax Distribution:Properties and Estimation Based on Ranked set sampling

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2020年第12期65卷 2169-2187页

作者： Rashad Bantan Amal s.Hassan Mahmoud Elsehetry Deanship of scientific Research King AbdulAziz UniversityJeddah21589Saudi Arabia Faculty of Graduate studies for statistical Research Cairo UniversityCairo11865Egypt Deanship of Information Technology King AbdulAziz UniversityJeddah21589Saudi Arabia

In this article,we offer a new adapted model with three parameters,called Zubair Lomax *** new model can be very useful in analyzing and modeling real data and provides better fits than some others new *** properties of the Zubair Lomax model are determined by moments,probability weighted moments,Renyi entropy,quantile function and stochastic ordering,among *** likelihood method is used to estimate the population parameters,owing to simple random sample and ranked set sampling *** behavior of the maximum likelihood estimates for the model parameters is studied using Monte Carlo *** measures including biases,mean square errors and relative efficiencies are used to compare *** the simulation study,we observe that the estimates based on ranked set sampling are more efficient compared to the estimates based on simple random *** importance and flexibility of Zubair Lomax are validated empirically in modeling two types of lifetime data.

关键词： Lomax distribution Zubair-g family moments maximum likelihood estimation ranked set sampling

The Advent of scientific Aircraft Navigation

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 Applied sciences 2016年第10期6卷 714-727页

作者： Jorge M. M. Barata António L. M. Mendes Cândido M. P. Morgado fernando M. s. P. Neves André R. R. silva Aerospace sciences Department Universidade da Beira Interior Covilh&atilde Portugal

Two Portuguese aerial navigators, Gago Coutinho and sacadura Cabral, crossed for the first time, from Europe to the south Atlantic in 1922;they developed and used for the first time scientific methods of astronomic navigation when flying out of sight of land: a path corrector and a precision sextant. Both navigation devices were tested during short flights from Lisbon to Madeira Island (1921) and the encouraging results obtained, allow the navigators to apply them with quite success into an intercontinental flight. The “path corrector” was invented by sacadura Cabral and Gago Coutinho with the intent to calculate graphically the angle between the longitudinal axis of an airplane and the direction of flight, taking into account the intensity and the direction of the winds. The regular sextant used by the navy could not be applied to aviation due to the difficulty of the definition of the sky-line at a normal flight altitude. Gago Coutinho developed a new model of sextant that could be used to measure the altitude of a star without the need of the sea horizon;this new device was called “precision sextant” and was improved with an artificial horizon line defined with the help of a water bubble. This device was later improved with an internal illumination system to allow its use during night flights and was used along the First Aerial south Atlantic Night Crossing, in 1927, performed by Portuguese airmen sarmento Beires, Jorge Castilho, Duvalle Portugal and Manuel Gouveia. An advanced version of this instrument started to be manufactured in Germany by C. Plath under the name of “system Admiral Gago Coutinho”.

关键词： History of the sextant Gago Coutinho Precision sextant

Environmental Isotopic Characterization of Groundwater and surface Water in Northeast Missan Province,south Iraq

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geologica sinica(English Edition) 2014年第4期88卷 1227-1238页

作者： Hussein Badr GHALIB Ali Riza sGüT selcuk University college of EngineeringGeology DepartmentSelcukTurkey Basrah University Geology DepartmentBasrahIraq

The present work studies the environmental isotopes assess groundwater characteristics of the different parts of the main aquifer in the northeast Missan Province in south of Iraq. Water samples of groundwater and surface water were collected for two dry and wet seasons during the water year of 2011-2012. The study shows that most of the groundwater in the aquifer falls above the global meteoric water line, and all the samples fall below the Mediterranean meteoric water line, indicating that these samples are a mixture of two water types. The tritium content of these samples supports this conclusion. The overall conclusion of this study indicates that there are two sources of groundwater recharge in the studied area： the ephemeral streams （Teeb and Dewerge） and major precipitation sources. According to the tritium levels at or below one tritium unit （TU） obtained from the water, supply wells are highly confined or ＂not vulnerable＂. Overall, the 3^H results imply that recent recharge has taken place during the last four to five decades. In the recharge area, the high tritium content in the southern part of the Teeb area suggests that the recharge originates from rapid infiltration of surface runoff. Therefore, the groundwater resources in the study area should be protected from contamination, because it will influence the aquifer in a relatively short period of time if any contamination enters the recharge areas of the aquifer.

关键词： Groundwater recharge Tritium environmental isotope meteoric water line Iraq

Cyclic stress-controlled tests on offshore clay

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2017年第2期9卷 376-381页

作者： s.Y. Thian C.Y. Lee Department of Civil Engineering Jalan Ikram-UnitenUniversiti Tenaga NasionalKajang43000Malaysia

One of the main concerns in cyclic behavior of soft clay is gradual degradation with the progression of loading cycle.A series of cyclic constant-volume direct simple shear(CDss) loading tests was performed on Malaysia offshore clay to study its undrained *** testing program consists of stresscontrolled tests with cyclic shear ratio ranging from 0.34 to 0.83 at different overconsolidation ratios(OCRs).For a given cyclic stress ratio in stress-controlled tests,the accumulated cyclic strain and pore water pressure increase with elevated number of *** heavily overconsolidated clay specimens,the negative cyclic pore water pressure is generated followed by positive cyclic pore water pressure as cyclic tests *** post-cyclic strength of offshore clay specimens is reduced by undrained cyclic stresscontrolled loading.

关键词： Offshore clay Cyclic degradation Undrained cyclic loading shear strength Pore pressure Overconsolidation ratio(OCR)

Implications of Onshore Development on Global software Engineering

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2023年第2期74卷 3029-3044页

作者： Abdulrahman M.Qahtani Ahmed s.Ghiduk College of Computers and Information Technology Taif UniversityP.O.Box 11099Taif21944Saudi Arabia Department of Mathematics and Computer science Faculty of ScienceBeni-Suef UniversityBeni-Suef62521Egypt

Recently software industry has paid significant attention to customizing software products across distributed *** the requirements of multiple clients across distributed borders is a crucial challenge for the software customization *** decision-making and local development at the client site are considered methods for reducing difficulties in communicating the requirements of multiple clients across distributed *** paper introduces a new model called the onshore development model(ODM)for accomplishing the customization requests in the distributed development process of *** model presents a scenario for enhancing the onsite development of specific requirements to reduce delays andmisunderstandings between the clients and the team *** model depends on moving the development process to the client’s *** empirical studies were conducted to evaluate the proposed model to measure its productivity,time performance,and cost *** proposed model has been compared with two other models:the basic model(BM),which allocates the decision-making process and the development process for teams at the vendor’s location,and the local decision-making model(LDec),which assigns the decision-making process for team at the client’s *** results of the empirical studies showed significant outperforming of the proposed model over the basic model and local decision-making model in productivity,time performance,and cost *** productivity of the proposed model improved by 39%and 10%more than the basic model and the local decision-making model,*** addition,the time performance of the proposed model became faster by 49%and 20.8%than the basic model and the local decision-making model,***,it reduced the total cost of the development process by 31%in terms of the salaries of all persons involved in requirements collecting,decision-making,and development.

关键词： Distributed development local development software customization

Leaching of copper from chalcopyrite concentrate by using ammonium persulphate in an autoclave:Determination of most suitable impeller type by using response surface methodology

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Central south University 2013年第3期20卷 622-628页

作者： M.D.Turan H.s.Altundogan Department of Metallurgical and Materials Engineering Fιrat UniversityElaz 23279Turkey Department of Bioengineering F rat UniversityElaz 23279Turkey

some effective parameters on the copper extraction from Kiire chalcopyrite concentrate were optimized by using response surface methodology （RsM）. Experiments designed by RsM were carried out in the presence of ammonium persulfate （APs） and different types of impeller in an autoclave system. Ammonium persulfate concentration and leaching temperature were defined numerically and three types of impellers were defined categorically as independent variables using experimental design software. The optimum condition for copper extraction from the chalcopyrite concentrate is found to be ammonium persulfate concentration of 277.77 kg/m3, leaching temperature of 389.98 K and wheel type of impeller. The proposed model equation using RsM has shown good agreement with the experimental data, with correlation coefficients R2 and RaZaj for the model as 0.89 and 0.84, respectively.

关键词： copper chalcopyrite leaching response surface methodology ammonium persulfate optimization

Microstructures and Mechanical Properties of Vacuum Brazed Ti3Al/TiAl Joints Using Two Ti-based Filler Metals

在线全文

学校读者我要写书评

暂无评论

Journal of Materials science & Technology 2016年第4期32卷 372-380页

作者： H.s.Ren H.P.Xiong B.Chen s.J.Pang B.Q.Chen L.Ye Department of Material science and Engineering Beihang University Beijing 100191 China Welding and Plastic Forming Division Beijing Institute of Aeronautical Materials Beijing 100095 China

Vacuum brazing of Ti3Al-based alloy to TiAI was firstly carried out by Ti-15Cu-15Ni （wt%） filler metal. A continuous Ti3Al band, Ti2Ni and Ti2Cu/Cu3Ti phases formed and the joint showed a shear strength of 53.8-112.4 MPa at room temperature. For the improvement of the joint strength, a new Ti--Zr--Cu--Ni--Fe filler alloy was designed, and its wettability on Ti3AI and TiA1 substrate was studied with the sessile drop method. After holding for 20 rain at 1010 ℃ the Ti--Zr--Cu--Ni--Fe filler showed a low contact angle of 20° and 21° on Ti3Al and TiAI substrate, respectively. The joint brazed with this novel filler mainly con- sisted of Ti-rich area, Ti3Al reaction layer and residual filler metal. With the increase of the brazing temperature, the amount of residual filler metal decreased and the TisAl reaction layer thickened. The Ti3Al/TiA1 joint brazed with Ti--Zr--Cu--Ni--Fe filler exhibited a lower hardness than that brazed with Ti--Cu--Ni filler. The corresponding joints brazed at 950 ℃ for 5 min presented the shear strength of 257.6± 33.6 MPa at room temperature and 304.8 ± 9.9 MPa at 600 ℃.

关键词： BrazingTitanium aluminidesMicrostructureshear strength