检索结果-南通市图书馆

Science China Chemistry 2010年第3期53卷 580-586页

作者： KHALIL Faghihi MEISAM Shabanian Polymer Research Laboratory Department of ChemistryFaculty of ScienceIslamic Azad University yang researchers club Islamic Azad University

Six new optically active poly(amide-imide)s(PAIs) 6a-f were prepared by direct polycondensation reaction of N-trimelli-tylimido-L-histidine 4 as a chiral diacid with various aromatic diamines *** phosphite(TPP)/pyridine(Py) in the presence of calcium chloride(CaCl2) and N-methyl-2-pyrrolidone(NMP) were successfully applied to direct polycondensation *** resulting new polymers were in good yields,and had inherent viscosities ranging between 0.29 and 0.41 dL g-1 and were detected with elemental analysis,FTIR,1H-NMR spectroscopy,specific rotation and differential scanning calorimeter(DSC),thermogravimetric analysis(TGA),and derivative of thermaogravimetry(DTG).Imidazole pendent groups of the polymer chains disturb interchain and intrachain interactions and make these PAIs readily soluble in polar aprotic solvents such as N,N-dimethylacetamide(DMAc),N,N-dimethylformamide(DMF),dimethylsulfoxide(DMSO),NMP and solvents such as sulfuric *** analysis indicated that the residual weight percents of polymers at 600 °C were between 56.47% and 68.76%,which show their thermal stability.

关键词： poly(amide-imide)s direct polycondensation optically active polymers imidazole histidine

Synthesis and Crystal Structure of 2-(4-Chlorophenyl)-1,4,5-triphenyl-1H-imidazole

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2012年第4期31卷 574-576页

作者： Ali Mohammad Amani Kazem Barati Young researchers club Shiraz BranchIslamic Azad University Young researchers club Yasooj BranchIslamic Azad University

The compound 2-（4-chlorophenyl）-1,4,5-triphenyl-1H-imidazole（1,C27H19ClN2） has been synthesized and its crystal structure was determined by single-crystal X-ray *** crystal of 1 belongs to the triclinic system,space group P with a = 10.3350（19）,b = 10.238（2）,c = 11.201（2） ,α = 85.957（16）,β = 83.148（15）,γ = 66.467（15）°,V = 1078.5（4） 3,Mr = 406.89,Z = 2,F（000） = 422,Dc = 1.257 g/cm3,μ = 0.193 mm-1,T = 298（2） K,S = 1.092,R = 0.0702 and wR = *** imidazole ring system is planar and makes a dihedral angle of 40.3° with the chlorobenzene ring.

关键词： crystal structure imidazole triclinic system

Total Pairwise Quantum Correlation and Entanglement in a Mixed-Three-Spin Ising-XY Model with Added Dzyaloshinskii-Moriya Interaction under Decoherence

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2016年第9期33卷 5-9页

作者： H.A.Zad Young researchers and Elite club Mashhad BranchIslamic Azad University

We investigate the behavior of geometric global quantum discord （GGQD） and concurrence （C） between half- spins of a mixed-three-spin （1/2, 1, 1/2） system with the Ising-XY model for which spins （1, 1/2） have the Ising interaction and half-spins （1/2, 1/2） have both XY and the Dzyaloshinskii Moriya interactions together, under the decoherence action. A single-ion anisotropy property with coefficient ζ is assumed for the spin-integer. This system which includes an analytical Hamiltonian is considered at the front of an external homogeneous magnetic field B in thermal equilibrium. Finally, we compare GGQD and C and express some interesting phase flip reactions of the total quantum correlation and pairwise entanglement between spins （1/2, 1/2）. Generally, we conclude that the concurrence and GGQD have different behaviors under the phase flip channel.

关键词： of is in for Total Pairwise Quantum Correlation and Entanglement in a Mixed-Three-Spin Ising-XY Model with Added Dzyaloshinskii-Moriya Interaction under Decoherence with

Reliability evaluation of future photovoltaic systems with smart operation strategy

在线全文

学校读者我要写书评

暂无评论

Frontiers in Energy 2016年第2期10卷 125-135页

作者： Amir AHADI Hosein HAYATI SeyedMohsen MIRYOUSEFI AVAL Young researchers and Elite club Ardabil Branch Islamic AzadUniversity Ardabil *** Iran

This paper investigates a new operation strategy for photovoltaic （PV） systems, which improves the overall reliability of the system as a result of the improvement in the reliability of the critical components. First, a mathematical model is proposed using the fault tree analysis （FTA） to estimate the reliability of the PV systems in order to find the suitable maintenance strategies. The implementations demonstrate that it is essential to employ smart maintenance plans and monitor the identified most critical components of PV systems. Then, an innovative analytical method based on the Markov process is presented to model smart operation plans in PV systems. The impact of smart operation strategy on the PV systems is then evaluated. The objective of this paper is to develop plans for improving the reliability of PV systems. A series of case studies have been conducted to demonstrate the importance of smart operation well as the applicability and method. strategies for PV systems as feasibility of the proposed

关键词： smart operation strategy renewable energy,fault tree analysis (FTA) Markov model

Two new methods for power flow tracing using bus power balance equations

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2014年第7期21卷 2712-2718页

作者： Noradin Ghadimi Young researchers club Ardabil BranchIslamic Azad University

Two new methods were presented for power flow tracing(PFT).These two methods were compared and the results were discussed in *** methods use the active and reactive power balance equations at each bus in order to solve the tracing *** first method considers the proportional sharing assumption while the second one uses the circuit laws to find the relationship between power inflows and outflows through each line,generator and load connected to each bus of the *** methods are able to handle loop flow and loss issues in tracing problem.A formulation is also proposed to find the share of each unit in provision of each *** methods are applied to find the producer and consumer's shares on the cost of transmission for each line in different case *** the results of these studies show,both methods can effectively solve the PFT problem.

关键词： load contribution power flow tracing proportional/non-proportional sharing network Zbus transmission cost allocation

Developing energy forecasting model using hybrid artificial intelligence method

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2015年第8期22卷 3026-3032页

作者： Shahram Mollaiy-Berneti Young researchers and Elites club Bandar Abbas Branch Islamic Azad University

An important problem in demand planning for energy consumption is developing an accurate energy forecasting model. In fact, it is not possible to allocate the energy resources in an optimal manner without having accurate demand value. A new energy forecasting model was proposed based on the back-propagation(BP) type neural network and imperialist competitive algorithm. The proposed method offers the advantage of local search ability of BP technique and global search ability of imperialist competitive algorithm. Two types of empirical data regarding the energy demand(gross domestic product(GDP), population, import, export and energy demand) in Turkey from 1979 to 2005 and electricity demand(population, GDP, total revenue from exporting industrial products and electricity consumption) in Thailand from 1986 to 2010 were investigated to demonstrate the applicability and merits of the present method. The performance of the proposed model is found to be better than that of conventional back-propagation neural network with low mean absolute error.

关键词： energy demand artificial neural network back-propagation algorithm imperialist competitive algorithm

Development of a least squares support vector machine model for prediction of natural gas hydrate formation temperature

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2017年第9期25卷 1238-1248页

作者： Mohammad Mesbah Ebrahim Soroush Mashallah Rezakazemi Young researchers and Elites club Science and Research Branch Islamic Azad University Young researchers and Elites club Ahvaz Branch Islamic Azad University Department of Chemical Engineering Shahrood University of Technology

Hydrates always are considered as a threat to petroleum industry due to the operational problems it can *** problems could result in reducing production performance or even production stoppage for a long *** this paper, we were intended to develop a LSSVM algorithm for prognosticating hydrate formation temperature(HFT) in a wide range of natural gas mixtures. A total number of 279 experimental data points were extracted from open literature to develop the LSSVM. The input parameters were chosen based on the hydrate structure that each gas species form. The modeling resulted in a robust algorithm with the squared correlation coefficients(R^2) of 0.9918. Aside from the excellent statistical parameters of the model, comparing proposed LSSVM with some of conventional correlations showed its supremacy, particularly in the case of sour gases with high H_2S concentrations, where the model surpasses all correlations and existing thermodynamic models. For detection of the probable doubtful experimental data, and applicability of the model, the Leverage statistical approach was performed on the data sets. This algorithm showed that the proposed LSSVM model is statistically valid for HFT prediction and almost all the data points are in the applicability domain of the model.

关键词： Hydrate formation temperature(HFT) Natural gas Sour gases Least squares support vector machine Outlier diagnostics Leverage approach

Influence of Non-Maxwellian Particles on Dust Acoustic Waves in a Dusty Magnetized Plasma

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2013年第11期60卷 615-622页

作者： M.Nouri Kadijani H.Zareamoghaddam Young researchers and Elite club Kashmar Branch Islamic Azad University

In this paper an investigation into dust acoustic sofitary waves （DASWs） in the presence of superthermM electrons and ions in a magnetized plasma with cold dust gains and trapped electrons is discussed. The dynamic of both electrons and ions is simulated by the generalized Lorentzian （κ） distribution function （DF）. The dust grains are cold and their dynamics are studied by hydrodynamic equations. The basic set of fluid equations is reduced to modified Korteweg-de Vries （mKdV） equation using Reductive Perturbation Theory （RPT）. Two types of solitary waves, fast and slow dust acoustic soliton （DAS） exist in this plasma. Caiculations reveal that compressive solitary structures are possibly propagated in the plasma where dust grains are negatively （or positively） charged. The properties of DASs are also investigated numerically.

关键词： dust acoustic soliton magnetized plasma superthermal electrons and ions trapped electrons

Orbital electronic heat capacity of hydrogenated monolayer and bilayer graphene

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2017年第2期26卷 375-381页

作者： Mohsen Yarmohammadi Young researchers and Elite club Kermanshah Branch Islamic Azad University Kermanshah Ira

The tight-binding Harrison model and Green＇s function approach have been utilized in order to investigate the contribution of hybridized orbitals in the electronic density of states（DOS） and electronic heat capacity（EHC） for four hydrogenated structures, including monolayer chair-like, table-like, bilayer AA- and finally AB-stacked graphene. After hydrogenation, monolayer graphene and bilayer graphene are behave as semiconducting systems owning a wide direct band gap and this means that all orbitals have several states around the Fermi level. The energy gap in DOS and Schottky anomaly in EHC curves of these structures are compared together illustrating the maximum and minimum band gaps are appear for monolayer chair-like and bilayer AA-stacked graphane, respectively. In spite of these, our findings show that the maximum and minimum values of Schottky anomaly appear for hydrogenated bilayer AA-stacked and monolayer table-like configurations, respectively.

关键词： hydrogenated monolayer and bilayer graphene Harrison model electronic heat capacity density of states Green's function

Phase Control of Transient Optical Properties of Double Coupled Quantum-Dot Nanostructure via Gaussian Laser Beams

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2018年第2期35卷 29-33页

作者： J.Shiri F.Shahi M.R.Mehmannavaz L.Shahrassai Young researchers and Elite club Tabriz BranchIslamic Azad University Department of Atomic and Molecular Physics University of Tabriz Young researchers and Elite club Mashhad BranchIslamic Azad University

We theoretically analyze the transient properties of a probe field absorption and dispersion in a coupled semiconductor double-quantum-dot *** show that in the presence of the Gaussian laser beams,absorption and dispersion of the probe field can be dramatically influenced by the relative phase between applied fields and intensity of the Gaussian laser *** and steady-state behaviors of the probe field absorption and dispersion are discussed to estimate the required switching *** estimated range is between 5-8 ps for subluminal to superluminal light propagation.

关键词： Phase Control of Transient Optical Properties of Double Coupled Quantum-Dot Nanostructure via Gaussian Laser Beams QDs