广州、香港、澳门月均温与月用电量关系初探

根据2000—2005年广州、香港与澳门的月用电量及气温数据,以线性回归方式分离了3地的月均气象用电量,计算了相对月均气象用电量和月均气象用电量密度,分析了月均温变化对它们的影响.结果显示,3地月均用电量中气温波动的平均值分别为12.9%、17.1%和18.5%;月均温分别超过24.55、24.81、24.45℃时,月均气象用电量密度对月均温的变化比较敏感,两者的关系也较密切;热季月均温对月均气象用电量密度的作用要强于冷季.

SMIF/微环境的应用及节能分析

在大面积洁净室内引入SMIF/微环境系统能在更好的满足工艺洁净等级的要求下,起到节能的效果。分析总结了影响SMIF/微环境系统的主要参数以及提出了这些参数的建议取值范围、具体分析了在引入SMIF/微环境系统后所带来的节能效果(通过降低微环境内的风机能耗以及系统内气流组织的优化,其最大节能效果可达60-86%)。

农网规划中负荷处理的新思路

本文针对按负荷均匀分布进行农网规划存在最大负荷同时率,致使大供电区域与各子供电区域负荷密度不相等这一问题,提出了按电量均匀分布进行规划设计的新思路,同时给出了电量密度这一新概念。在此基础上,还提出了对集中负荷处理的新思路。这些负荷处理方法对农网的规划设计和建设改造具有一定的指导意义。

An Analytical Model of Drain Current for Ultra-Thin Body and Double-Gate Schottky Source/Drain MOSFETs Accounting for Quantum Effects

A compact drain current including the variation of barrier heights and carrier quantization in ultrathin-body and double-gate Schottky barrier MOSFETs （UTBDG SBFETs） is developed. In this model, Schrodinger＇s equation is solved using the triangular potential well approximation. The carrier density thus obtained is included in the space charge density to obtain quantum carrier confinement effects in the modeling of thin-body devices. Due to the quantum effects, the first subband is higher than the conduction band edge, which is equivalent to the band gap widening. Thus, the barrier heights at the source and drain increase and the carrier concentration decreases as the drain current decreases. The drawback of the existing models,which cannot present an accurate prediction of the drain current because they mainly consider the effects of Schottky barrier lowering （SBL） due to image forces,is eliminated. Our research results suggest that for small nonnegative Schottky barrier （SB） heights,even for zero barrier height, the tunneling current also plays a role in the total on-state currents. Verification of the present model was carried out by the device numerical simulator-Silvaco and showed good agreement.

Numerical Study of Optimization of Layer Thickness in Bilayer Organic Light-Emitting Diodes

A numerical model for bilayer organic light-emitting diodes (OLEDs) is developed under the basis of trapped charge limited conduction.The dependences of the current density on the layer thickness,trap properties and carrier mobility of the hole transport layer (HTL) and emission layer (EML) in bilayer OLEDs of the structure anode/HTL/EML/cathode are numerically investigated.It is found that,for given values of the total thickness of organic layers,reduced depth of trap,total density of trap,and carrier mobility of HTL as well as EML,there exists an optimal thickness ratio of HTL to EML,by which a maximal quantum efficiency can be achieved.Through optimization of the thickness ratio,an enhancement of current density and quantum efficiency of as much as two orders of magnitude can be obtained.The dependences of the optimal thickness ratio to the characteristic trap energy,total density of trap and carrier mobility are numerically analyzed.

适用于饮料和食品罐内壁涂覆的镀锡机组钝化工艺

介绍了适用于饮料和食品罐内壁涂覆的镀锡板生产的流程。探讨了在不同生产速率下,电量密度对钝化膜重和后续涂层性能(包括附着力、抗硫性和抗酸性)的影响。通过研究不同电量密度下所得钝化膜的组织结构,分析了涂层附着力差的原因。90 C/cm^2下所得的钝化膜性能可以满足饮料食品罐的使用要求。

Neural-Network-Based Charge Density Quantum Correction of Nanoscale MOSFETs

For the treatment of the quantum effect of charge distribution in nanoscale MOSFETs,a quantum correction model using Levenberg-Marquardt back-propagation neural networks is presented that can predict the quantum density from the classical density. The training speed and accuracy of neural networks with different hidden layers and numbers of neurons are studied. We conclude that high training speed and accuracy can be obtained using neural networks with two hidden layers,but the number of neurons in the hidden layers does not have a noticeable effect, For single and double-gate nanoscale MOSFETs, our model can easily predict the quantum charge density in the silicon layer,and it agrees closely with the Schrodinger-Poisson approach.

Material Growth and Device Fabrication of GaN-Based Blue-Violet Laser Diodes

Studies on first GaN-based blue-violet laser diodes(LDs) in China mainland are reported.High quality GaN materials as well as GaN-based quantum wells laser structures are grown by metal-organic chemical vapor deposition method.The X-ray double-crystal diffraction rocking curve measurements show the full-width half maximum of 180″ and 185″ for (0002) symmetric reflection and (10 12) skew reflection,respectively.A room temperature mobility of 850cm2/(V·s) is obtained for a 3μm thick GaN film.Gain guided and ridge geometry waveguide laser diodes are fabricated with cleaved facet mirrors at room temperature under pulse current injection.The lasing wavelength is 405 9nm.A threshold current density of 5kA/cm2 and an output light power over 100mW are obtained for ridge geometry waveguide laser diodes.

Fabricating a Micro Electromagnetic Actuator with High Energy Density

This paper introduces a new technology to fabricate a micro electromagnetic actuator with high energy density without an enclosed magnetic circuit. This technology includes fabricating multi-turns planar micro coils and fabricating the thick magnetic （NiFe） core on the silicon wafer. The multi-turns planar micro coils are fabricated by the electroplating method from the surface along the line and by dynamically controlling the current density of the copper electrolytes. In order to fabricate thick NiFe plating,the adhesion properties between the NiFe plating and the silicon substrates are improved by changing the surface roughness of the silicon substrates and increasing the thickness of the seed layer. Furthermore,the micro electromagnetic actuator is tested and the energy density of the actuator is evaluated by force testing. The experiments show that the microactuator is efficient in producing high magnetic energy density and high magnetic force.

Effect of the amount of zinc-doped on the electrochemical performance of nickel hydroxide

The nickel hydroxide prepared by micro-emulsion method was doped by coprecipitated Zn. The effect of the amount of zinc-doped on the properties of Ni(OH)2 such as the reversibility of the electrode reaction, the charge efficiency and active material utilization ratio of nickel electrode, and discharge specific capacity was studied by cyclic voltammetry and constant current charge-discharge tests. The results indicate that the specific discharge capacity of nickel hydroxide obtained by micro-emulsion method is much less than its theoretical value because the transfer of electrons and the diffusion of protons H+ are hindered owing to its crystal grain size in a nanometer range and thus possessing higher crystal interface resistance. The crystal cells are swelled and the crystal defects increased in prepared material due to part of Ni2+ substituted by Zn2+ when zinc and nickel hydroxide are coprecipitated. Hence, the electrons and protons H+ in the electrode reaction are transferred easily, the electrochemical behavior of nickel electrode is improved and discharge specific capacity is promoted. However, the performance of Ni(OH)2 is gradually enhanced with the addition of zinc-doped at first, while slowly decreased after the content of zinc is added to a certain value. The best electrode reaction reversibility, the highest electrode charge efficiency, the highest active material utilization ratio and the largest specific capacity on discharge are available when the mass fraction of Zn doped in nickel hydroxide by coprecipitation reaches 2.5 %.

Corrosion behaviors and mechanism of electroless Ni-Cu-P/n-TiN composite coating

In the present investigation, electroless Ni-Cu-P/n-TiN composite coating was prepared using alkaline citrate-based bath. X-ray diffraction （XRD）, scanning electron microscopy（SEM）, energy-dispersive spectroscopy（EDS）, electrochemical measurements, weight loss tests and Raman spectrometer were used to character the properties of the coating. As the Cu content increased from 7.3 wt% to 24.8 wt%, the corrosion current density of the Ni-Cu-P/n-TiN coating decreased from 10.80 to 4.34 ~tA. And the inclusion of Cu in NiP alloy resulted in refinement and less porosity in microstructure. The addition of TiN resulted in a slight decline in anti-corrosion property of the coating. As the mass loss test showed, Ni-24.8%Cu-P exhibited perfect corrosion resistance. Studies by Raman spectroscopy on coatings proved that Cu（II）3（PO4）（OH）3, Cu（OH）2 and CuO were examined while no compound of nickel was found, and Cu exhibited preferred corrosion in saline solution, providing cathodic protection to Ni alloy.

三元正极材料清洗废水资源化回收零排放处理工艺

锂电三元正极材料在清洗过程中产生含有Li^(+)、Al^(3+)、SO_(4)^(2-)、镍钴锰氧化物及少量其他离子的废水,对该三元正极材料清洗废水的资源化回收零排放处理工艺进行了阐述。该废水处理系统涉及的成套工艺包括预处理单元、废水减量化单元、沉锂单元和制纯水单元。重点对Al^(3+)的去除、膜浓缩、沉锂等关键工艺进行了重点描述,最后通过实际与理论对比分析,达到了预期的设计目标——锂资源得到有效回收、废水实现全部回用。通过对实际案例的相关数据的例举和分析,证明了本套废水处理工艺的可行性和可靠性,为锂电三元正极材料清洗废水的治理提供了典型的参考工艺路线。

Applications of Compton scattering

Compton scattering is used very widely. In this article, we depict an overall picture for its applications which are based on two basic theories. The first is the electron densitometry theory related to electron density. According to this theory its applications are in two fields: one is Compton scatter densitometry (CSD), the other is Compton scatter imaging (CSI). The second technique involves the electron momentum distribution and Compton profile. Applications of this technique are mainly the Compton profile analysis (CPA) and the Compton profile or the electron momentum distribution in physics and chemistry. Future research fields are suggested according to the current situation and limits of this technique and a promising prospect is unfolded.

Investigation of Mg^2＋/Li^＋ Separation by Nanofiltration

The Mg2+/Li+/Cl solutions were filtrated with a commercially available DK nanofiltration membrane to investigate the possibility to enrich the lithium component.The investigation was significant as such an approach might be a competing substitute for the present lithium purification industry and the environmental protection purpose.The Donnan steric pore model(DSPM) was implemented for the prediction.The separation of Mg2+/Li+was mainly affected by the working pressure(or the permeation flux) and a limiting separation factor was found around 0.31.The effective membrane charge density was evaluated and its dependence on the permeation flux as well as the ion pattern was discussed.For predicting an actual separation of electrolytes,the experimental investigation seems necessary for the reliability and efficiency.

Anti-flooding of polymer electrolyte membrane fuel cell with in-plate adverse-flow flow-field

The stoichiometric ratios and related regimes, which can promote anti-flooding of polymer electrolyte membrane fuel cell （PEMFC） with in-plate adverse-flow flow-field （IPAF）, were investigated. Two flow combinations, which are the simple and complex adverse-flow between plates （ABP） that can be realized by IPAF, were employed. Constant stoichiometric ratios examination indicates that the complex ABP could improve anti-flooding of PEMFC better in the medium （greater than 200 mA/cm2 and less than 1 000 mA/cm2） and high （greater than 1 000 mA/cm2） current densities than the simple ABP. More stoichiometric ratios were introduced to find the cathode critical stoichiometry. Under the condition of cathode critical stoichiometry, the maximal local relative humidity of both electrodes of complex ABP is equal to 100% and below while the anti-flooding of the cathode of simple ABP is not satisfactory in the medium and high current densities. Further study shows that the mechanism of fuel cell, which is the imerdependence between the electrodes effect, can make significant contribution to anti-flooding.

Quantum Teleportation and Superdense Coding via W-Class States

Abstract According to the protocol of Agrawal et al., we propose a cavity QED scheme for realization of teleportation and dense coding. Instead of using EPR states and GHZ states, our scheme is more insensitive to the loss of one particle by using a W-class state as a quantum channel. Besides, our scheme is immune to thermal field, and does not require the cavity to remain in the vacuum state throughout the procedure.

Electron Acceleration and Bunch Generation by Intense Femtosecond Laser Pulse in Preplasma of a Target

We present analytical studies of electron acceleration in the low-density preplasma of a thin solid target byan intense femtosecond laser pulse.Electrons in the preplasma are trapped and accelerated by the ponderomotive forceas well as the wake field.Two-dimensional particle-in-cell simulations show that when the laser pulse is stopped by thetarget,electrons trapped in the laser pules can be extracted and move forward inertially.The energetic electron bunchin the bubble is unaffected by the reflected pulse and passes through the target with small energy spread and emittance.There is an optimal preplasma density for the generation of the monoenergetic electron bunch if a laser pulse is given.The maximum electron energy is inverse proportion to the preplasma density.

Electronic and Magnetic Properties of Double Perovskite Ca_2CrSbO_6

First-principles calculations have been performed for the study of the electronic band structure and ferromagnetic properties of double perovskite Ca2CrSbO6. The density of states, total energy, spin magnetic moment, and charge density were calculated and analyzed in details. It is found that Ca2CrSbO6 has a stable ferromagnetic ground state and the spin magnetic moment per molecule is about 2.99#B. The chromium contributes the most in the total magnetic moments. The results indicate that Ca2CrSbO6 is half-metallic.

Four-Electron Quantum Ring in a Magnetic Field

We study a quantum ring （QR） with four electrons in a perpendicular external magnetic field B by exact diagonalization. The low-lying spectra of the QR as a function orb are obtained. A phase diagram is presented indicating that the angular momentum and the spin of the ground state of the QR may jump when B and/or the radius of the QR vary, and a corresponding analysis is performed. By plotting the density functions of the QR, the ground-state configuration is found to be a regular quadrangle. Furthermore, the features of the ground-state persistent current are revealed.

The Upper Mixed Layer during Coastal Upwelling Events on the Northern Portugal Shelf

The upper mixed layer (UML) depth obtained from temperature is very close to that from density:the maximum is about 15m. This indicates that temperature is a good indicator of mixed layer during measurements. When the surface heat flux is balanced by a cross-shore heat flux, the surface mixed layer depth obtained from the WM model (Weatherly and Martin, 1978),hPRT, is roughly the same as observed. The mixed layer depth calculated from the PWP model (Price, Weller and Pinkel, 1986) is close to the depth obtained from thermistor chain temperature data. The results show that both the WM model and PWP model can provide a good estimate of stratification in the study area during the cruise. The value of log( h/u3) is about 9.5 in the study area, which shows that the study area is strongly stratified in summer. Observations on the northern Portugal shelf reveal high variability in stability, giving rise to semi-diurnal, semi-monthly and diurnal oscillations, and long term variations. The fortnightly oscillations are highlighted by post-springs and post-neaps. The stirring of spring tide is reinforced by strong wind mixing which brings about complete vertical homogeneity everywhere. The semi-diurnal periodic stratification is very pronounced because the major axis of the tidal ellipse is orientated acrossshore, even though the tidal current is weak in this area, the maximum stratification is observed around the middle of ebb, and, the water at this time is much warmer. The diurnal oscillation results from the upper ocean response to heating and wind mixing when solar heating warms and stabilizes the upper ocean. There is a clear relationship between upper mixed layer depth and wind-stress magnitude at subtidal frequencies. Stronger winds result in a deeper surface mixed layer. Typically, the surface mixed layer depth lags the wind stress by 6 -12 h.