Wavelength Assignment in WDM Optical Networks with Limited-range Wavelength Conversion

According to previous studies, limited range wavelength conversion (LWC) can improve the performance of optical network. In this paper, the effects of FWM (Four Wave Mixing) and XGM (Cross-Gain Modulation) conversion are both examined. It is found that the performance difference between LWC and full conversion becomes quite remarkable with the increase in numbers of wavelengths per-link. So in order to improve the performance of optical network with limited conversion in the case of large number of wavelengths, three simple dynamic wavelength assignment algorithms (LUWC, FUWC and WSM) are proposed. Simulation results show that the algorithms greatly reduce the blocking probabilities of networks with LWC. Moreover, the algorithms require no global information of network.     

Hydrogen production by reforming methane in a corona inducing dielectric barrier discharge and catalyst hybrid reactor

A novel corona inducing dielectric barrier discharge(CIDBD) and catalyst hybrid reactor was developed for reforming methane. This corona inducing technique allows dielectric barrier discharge(DBD) to occur uniformly in a large gap at relatively low applied voltage.Hydrogen production by reforming methane with steam and air was investigated with the hybrid reactor under atmospheric pressure and temperatures below 600°C.The effects of input power,O2/C molar ratio and preheat temperature on methane conversion and hydrogen selectivity were investigated experimentally.It was found that higher methane conversions were obtained at higher discharge power,and methane conversion increased significantly with input power less than 50 W;the optimized molar ratio of O2/C was 0.6 to obtain the highest hydrogen selectivity(112%);under the synergy of dielectric barrier discharge and catalyst,methane conversion was close to the thermodynamic equilibrium conversion rate.     

Influence of silane coupling agent on the conversion film forming of galvanized steel treated with cerium salt

The influence of silane coupling agent on the film forming of galvanized steel treated with cerium salt was studied by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), and the corrosion resistance of conversion films was analyzed by electro interstitial scanning (EIS). The results show that silane coupling agent KH-570 has significant influence on the compactness and homogeneity of cerium conversion films, and the process of film forming is promoted by increasing the content of tervalent and tetravalent cerium oxide. The impedance value of the cerium conversion film, especially modified with KH-570, is greater than that of the base metal, which reveals that it is necessary to add silane coupling agent to the film-forming solution in order to improve the corrosion resistance of the conversion film.     

Relations between Mountain Settlements and Geographic Factors in Three Gorges Reservoir Area

Compared with previous studies,the research attempted to establish the appropriate quantitative models to explain the relations between settlement density Diand geographic factors,which could make a scientific guidance to the mountain settlements planning. Five factors,including slope,relief amplitude,distance to river, distance to cultivated land, and distance to road, were identified through principal component analysis( PCA). The inherent relations between five factors and Di( settlement density)were modeled by regression analysis. The results are as follows.( 1) The associations among Diand slope,relief amplitude,river,road are better modeled by the exponential decay line; with the buffer distance of slope, relief amplitude, distance to river and distance to road increasing, Didecreases.( 2) The associations between Diand cultivated land are better modeled by the quadratic polynomial line; with the buffer distance of cultivated land increasing,Diincreases first, and then dramatically decreases.( 3) The area within 500 m from the road,within 500 m from the cultivated land,within 1 600 m from the river,within the relief amplitude of 30-200 m,and the area within the slope of 0°-10° are the fitting land for settlements,and it is very important to lay the mountain settlements on those optimized regions.     

切比雪夫多项式的数字预失真算法及其FPGA实现

将切比雪夫多项式引入到数字预失真器的设计中,利用其特有的递归生成特性,提出了一种奇偶阶分离的生成方法,避免了高阶幂次操作并节约了资源.仿真表明,切比雪夫多项式预失真器的效果和收敛性能均优于现有的普通以及正交多项式.在现场可编程门阵列(field-programmable gate array,FPGA)上实现了设计,经过定点仿真验证,所设计的预失真器可以有效地抑制带外频谱泄漏,邻道泄漏比(adjacent channel leakage radio,ACLR)比普通记忆多项式有5~10 d B的提升.     

Optimization of polymer electrolytes for quasi-solidstate dye-sensitized solar cells

The dye-sensitized nanocrystalline TiO2 thin filmsolar cells (DSSCs) have attracted much attention since1990s[1— , due to their high light to electrical energy 4]conversion efficiency. So far, many studies have beenmade on the use of liquid electrolytes such as acetonitrile,3-methoxypropionitrile and a mixture of ethylene/pro-pylene carbonate (EC/PC) containing I? /I3 redox cou-?ple. A light to electrical energy conversion efficiency of7%— 12% has been obtained for DSSC using liquid e…     

Simulation of mode conversion at the magnetopause

Two-dimensional(2-D)and three-dimensional(3-D)hybrid simulations are carried out for mode conversion from fast mode compressional wave to kinetic Alfvn waves(KAWs)at the inhomogeneous magnetopause boundary.For cases in which the incident fast wave propagates in the xz plane,with the magnetopause normal along x and the background magnetic field pointing along z,the 2-D (xz)simulation shows that KAWs with large wave number kxρi～1 are generated near the Alfve′n resonance surface,whereρi is the ion Larmor radius.Several nonlinear wave properties are manifest in the mode conversion process.Harmonics of the driver frequency are generated.As a result of nonlinear wave interaction,the mode conversion region and its spectral width are broadened.In the 3-D simulation,after this first stage of the mode conversion to KAWs with large kx,a subsequent generation of KAW modes of finite ky is observed in the later stage,through a nonlinear parametric decay process.Since the nonlinear cascade to ky can lead to massive transport at the magnetopause,the simulation results provide an effective transport mechanism at the plasma boundaries in space as well as laboratory plasmas.     

Thermodynamics and phase transformations in the recovery of zinc from willemite

Willemite is a common component of zinc and lead metallurgical slags that, in the absence of effective utilization methods, cause serious environmental problems. To solve this problem and increase zinc recovery, we proposed a novel extraction method of zinc from willemite by calcified roasting followed by leaching in NH₄Cl-NH₃·H₂O solution. The thermodynamics and phase conversion of Zn₂SiO₄ to zinc oxide (ZnO) during calcified roasting with CaO were investigated. The mechanism of mineralogical phase conversion and the effects of the CaO-to-Zn₂SiO₄ mole ratio (n(CaO)/n(Zn₂SiO₄)), roasting temperature, and the roasting time on zinc-bearing phase conversion were experimentally investigated. The results show that Zn₂SiO₄ was first converted to Ca₂ZnSi₂O₇ and then to ZnO. The critical step in extracting zinc from willemite is the conversion of Zn₂SiO₄ to ZnO. The zinc percent leached in the ammonia leaching system rapidly increased because of the gradual complete phase conversion from willemite to ZnO via the calcified roasting process.     

HEMT压力传感器

利用Al Ga N/Ga N半导体的极化效应在异质结界面产生二维电子气(2DEG)的特性,设计了一种基于高电子迁移率场效应管(HEMT)的压强传感器;并利用标准的微电子工艺和背部深硅刻蚀技术制作了器件;对器件在不同压强下的源-漏I-V特性进行了测试和评价.结果表明本文设计制作的压强传感器的I-V特性对压强的变化能做出灵敏的反应.Ⅲ族氮化物半导体器件具有高速度、高灵敏、大功率和耐高温等特点,本压强传感器具有更广的应用领域.     

Low cycle fatigue behavior of high strength gun steels

The low cycle fatigue (LCF) behavior of two high strength steels, with nominal chemical compositions (mass fraction, %)of 0.40C-1.5Cr-3Ni-0.4Mo-0.2V (PCrNi3MoV) and 0.25C-3Cr-3Mo-0.8Ni-0.1Nb (25Cr3Mo3NiNb), was investigated by using the smooth bar specimens subjected to strained-controlled push-pull loading. It is found that both steels show cyclic softening, but 25Cr3Mo3NiNb steel has a lower tendency to cyclic softening. 25Cr3Mo3NiNb steel has higher fatigue ductility, and its transition fatigue life is almost three times that of PCrNi3MoV. 25Cr3Mo3NiNb steel also shows higher LCF life either at a given total strain amplitude above 0.5% or at any given plastic strain amplitude, despite its lower monotonic tensile strength than that of PCrNi3MoV.It also means that 25Cr3Mo3NiNb steel can endure higher total strain amplitude and plastic strain amplitude at a given number of reversals to failure within 104. 25Cr3Mo3NiNb steel is expected to be a good gun steel with high LCF properties because only several thousand firings are required for gun barrel in most cases.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with