30M-35kV/2000A高温超导电缆制冷系统

本文介绍了我国新研制成的首条并网运行的热绝缘型30M-35KV/2000A高温超导电缆制冷系统。该制冷系统主要有液氮泵箱、过冷箱、高真空输液管道、液氮贮槽、辅助减压抽空系统、泵箱及气动阀门供气系统、监控系统所组成。冷却方式是过冷液氮循环,制冷方式是G-M制冷机和减压抽空(备用)。给出了制冷系统的运行结果。     

Crystallization of (Bi,Nd)4Ti3O12 films in N2 environment by chemical solution deposition

(Bi,Nd)₄Ti₃O₁₂ (BNT) ferroelectric films were deposited on Pt/Ti/SiO₂/Si substrates by chemical solution deposition and crystallized in an N₂ environment after pre-annealing in air at 500 °C. The effect of crystalline temperature on the structural and electrical properties of the BNT films was studied. The BNT films annealed in N₂ in the temperature range of 630 °C to 670 °C were crystallized well and the average grain size increased with increasing crystalline temperature, while the remanent polarization and dielectric constant of the films are not a monotonic function of the crystalline temperature. The BNT films crystallized at 650 °C have the largest remanent polarization value of 2P_r=63.6 μC/cm², a dielectric constant of 344 at 10 kHz, and a fatigue-free characteristic. A positive correlation between the remanent polarization and the dielectric constant of the BNT films has been observed. PACS 81.20.Fw; 81.40.Ef; 77.84.-s     

运营商播种农村市场

转型是电信运营商在新形势下的必然战略选择，开创蓝海则是该战略中的一个方向。对于我国的电信运营商们来说，农村市场拥有着巨大的潜力，他们都纷纷将其作为未来的工作重点之一。在大的战略方向明确之后，运营商们的重点也逐渐在向具体工作的执行方面转移，近日出现的“沙盘”概念似乎也在验证着这样一种趋势。当然，运营商们并不会仅限于这种纸上谈兵式的模拟，他们的农村市场开拓工作已经在进行中了。     

手机用户手册问题解析

手机用户手册不仅是对手机的介绍和使用指南，而且是生产厂家对其产品和服务品质的一份承诺。如今手机用户手册貌似内容完备，但其实存在很多问题。     

用红外热成像技术精确测定物体发射率

根据红外探测器对物体辐射的输出响应，从实际测量的角度提出了物体发射率的一般性定义，分析了红外热成像技术进行精确测量的条件，导出了物体温度Ｔｏｂｊ、环境温度Ｔｓｕｒ、物体发射率ηｏ和测量精度ｅ之间的关系，并建立了一套用红外热成像技术精确测定ηｏ的方法，实验表明该方法可获得满意的测量结果     

紫外光电材料ZnO的反应溅射制备及研究

采用直流反应溅射法分别在Si(111),Si(001),及K4玻璃衬底上制备ZnO薄膜,研究了氧氩比、衬底温度以及退火处理对于晶体结晶质量的影响,发现生长过程中的退火处理提高了薄膜质量和晶面取向.通过优化生长条件,在衬底温度为350℃,氧氩比为1:2的条件下生长出了XRD半高宽为01°、C轴取向高度一致的ZnO薄膜.     

q-deformed boson-realization model applied to vibrational spectrum of sulfur dioxide

Aq-deformed boson-realization model is presented to study both stretching and bending vibrations of sulfur dioxide, where Fermi resonances are taken into account. Our results are compared with those of other models.     

A Monte Carlo study of the thermal properties of Cu3Au low index surfaces

The thermal dependencies of composition and order of the (111), (100) and (110) Cu₃Au surfaces are studied at the atomic scale by means of Monte Carlo simulations in the “transmutational” ensemble at constant volume. The question addressed is the extent to which such simulations carried on with a model N-body potential designed on the basis of bulk energetic and mechanical properties allow predictions consistent with experimental observations of the surface. Although the currently available experimental data still leave unanswered questions, many of them allow for comparison with modelling. Qualitative agreement is found for temperature dependencies of both surface composition and order, and the simulation results are discussed in detail. Some clear discrepancies are found as well, in particular (but not only) in the case of the (110) surface and its first neighbouring layer. Although the origin of such differences is not yet clear, it is suggested that they may serve to assess and to improve the model in the light of quantitative surface studies.     

A physical and scalable I-V model in BSIM3v3 for analog/digitalcircuit simulation

A new physical and continuous BSIM (Berkeley Short-Channel IGFET Model) I-V model in BSIM3v3 is presented for circuit simulation. Including the major physical effects in state-of-the art MOS devices, the model describes current characteristics from subthreshold to strong inversion as well as from the linear to the saturation operating regions with a single I-V expression, and guarantees the continuities of I_ds, conductances and their derivatives throughout all V_gs, V_ds, and T_bs, bias conditions. Compared with the previous BSIM models, the improved model continuity enhances the convergence property of the circuit simulators. Furthermore, the model accuracy has also been enhanced by including the dependencies of geometry and bias of parasitic series resistances, narrow width, bulk charge, and DIBL effects. The new model has the extensive built-in dependencies of important dimensional and processing parameters (e.g., channel length, width, gate oxide thickness, junction depth, substrate doping concentration, etc.). It allows users to accurately describe the MOSFET characteristics over a wide range of channel lengths and widths for various technologies, and is attractive for statistical modeling. The model has been implemented in the circuit simulators such as Spectre, Hspice, SmartSpice, Spice3e2, and so on     

LaBaMnO薄膜的铁磁共振

用电子自旋共振实验研究La_0.65Ba_0.35MnO₃(LBMO)薄膜的磁性,从磁性膜的各向异性铁磁共振谱得到不同角度θ_h时的共振磁场B_r,求出样品的等效磁场B_eff及旅磁比γ,并通过样品的饱和磁化强度M_s,求出各向异性常数K.