台阶式溢洪道非掺气水流水面线的计算

台阶式溢洪道水面线是确定边墙高度的重要参数,目前尚无系统的研究成果.根据明渠非均匀渐变流理论,分析了台阶段水面线的计算方法;模型试验表明,用非均匀渐变流理论计算台阶式溢洪道非掺气水流水面线时,必须考虑局部水头损失的影响.经对比分析,台阶上的局部阻力系数ζ=0.5时计算水深和实测水深吻合良好.溢流反弧段水面线可以用动量方程给出的公式计算.同时,对于坡度为30°,51.3°和60°的WES曲线段,也通过模型试验给出了水面线的计算式.对比分析认为,本文给出的台阶式溢洪道非掺气水流全程水面线的计算方法简单,精度高.

非掺半绝缘磷化铟晶片的制备及其均匀性

对高温退火非掺磷化铟 (In P)制备的半绝缘晶片的电学性质和均匀性进行了研究 .非掺低阻 N型磷化铟晶片分别在纯磷气氛和磷化铁气氛下进行 930℃、80 h退火均可获得半绝缘材料 .但在这两种条件下制备的两种 5 0 mm半绝缘晶片却呈现出不同的电学性质和均匀性 .纯磷气氛下制备的磷化铟片的电阻率和迁移率分别达到 10 6 Ω·cm和 180 0 cm2 / (V· s) ;而在磷化铁气氛下退火获得的半绝缘片的电阻率和迁移率分别高达 10 7Ω· cm 和30 0 0 cm2 / (V· s)以上 .对这两种半绝缘片和原生掺铁磷化铟半绝缘片的 PL - Mapping结果进一步比较表明 :在磷化铁气氛下退火获得的半绝缘材料的均匀性最好 。

非掺锑化镓抛光工艺研究

分析了非掺锑化镓单晶片的化学抛光机制和影响获得表面质量良好的非掺锑化镓单晶片的因素，得到了非掺锑化镓的抛光工艺参数。利用该工艺可以制备表面光洁、平整、无缺陷的非掺锑化镓单晶抛光片。

非掺SI-GaAs单晶热处理的研究

采用闭管Ａｓ气氛保护高－低－中温热处理方法进行非掺ＳＩ－ＧａＡｓ单晶热处理的研究，结果表明晶体的特性有明显的改善，一般晶体的迁移率可提高一倍以上，在Φ３英寸非掺ＳＩ－ＧａＡｓ单晶研究中，其晶体的电阻率不均匀性≤１５％；ＥＬ２ＲＳＤ≤５％；ＰＬ－Ｍａｐ－ｐｉｎｇ≤９％。

非掺半绝缘GaAs单晶的垂直梯度凝固生长

研究了非掺GaAs半绝缘单晶的液封垂直梯度凝固法(VGF)生长技术,解决了Si沾污和C浓度的控制问题,得到了直径2英寸非掺半绝缘低位错单晶。测试表明:该单晶的位错密度较LEC单晶下降近一个数量级,电学参数与LEC单晶类似,接近国外VGF单晶的参数指标。

深亚微米非均匀掺杂MOSFET的衬偏效应及开启电压模型

本文根据MOS器件沟道区离子注入引起的衬底杂质非均匀分布情况，提出了一个简单的衬底杂质分布的近似．并以此导出了非均匀掺杂下开启电压的衬偏效应模型．模型中采用了一个双曲函数解决了在不同掺杂区域的边界处，电流（或开启电压）对衬偏VBS的导数的不连续问题，并可通过调整参数δ计及实际器件中衬底掺杂的缓变过程．本文还给出一个与村偏相关的短沟道效应公式，准确地反应了深亚微米器件衬偏效应减小的现象．模型计算的结果与数值模拟的结果十分一致．

基于非充分掺混模式的流域来水组成模型

针对如何减小数值求解对流输运方程耗散误差的问题,引进断面计算浓度的概念来计算河段平均浓度,提出了非充分掺混模式的有限控制体积法离散对流输运方程的新算法,据此构建了模拟流域内的水源组成以及不同水源在流域内的时空变化情况的流域来水组成模型。通过数值试验与具体实例验证,结果表明所提出的非充分掺混模式的新算法可有效地提高流域来水模型的计算精度。

非金属元素N-S共掺杂SnO_(2)电性能第一性原理研究

基于密度泛函理论第一性原理和平面波超软赝势法,采用广义梯度近似法构建了非金属元素N、S单掺,以及N-S共掺的SnO_(2)的超晶胞,分析这三类超晶胞的焓变、能带图、态密度、电荷布局以及导电率。理论结果表明,N和S单掺杂以及N-S共掺杂都可以使SnO_(2)的带隙变小,能带紧密,而N-S双掺杂的效果最好。其中,在价带中部S原子和N原子的掺入均引入了新能级,S原子的轨道和N原子的轨道与Sn轨道发生杂化,使得电子转移加剧。价带顶被S原子的3p轨道和N原子,2p轨道占据,会有更多的空穴载流子,价带顶部向上移动。N、S原子共掺杂时,轨道共同杂化,效果最明显,电性能变好。

食用油中掺入非食用油的检验方法

食用油是甘油和各种脂肪酸形成的甘油兰酯混合物,食用油中掺入桐油的检验主要有三氯化锑一三氯甲烷界面法、亚硝酸法、硫酸法和苦昧酸法。食用植物油中掺入蓖麻油的检验主要有乙酵溶解法、气味与沉淀法和呈色反应法。回收油脂的掺伪检验主要有酸值(AV)测定、过氧化值(POV)测定、羰基值的测定和薄层色谱鉴定煎炸油。

纵向非均匀掺铒的光波导放大器特性数值模拟研究

提出一种通过非均匀掺铒方法提高光波导放大器增益和抽运效率的优化设计方案 ,并在有限元法基础上构建了光波导放大器模型 .计算中考虑到合作上转换、交叉弛豫和激发态吸收等效应 .利用自适应法求解了两种铒离子浓度分布方案 ,分别使脊形光波导放大器增益在固定长度和增益最大值有 10 2 7%和 5 6 5 %的提高 .计算结果与级联掺铒玻璃样品的实验结果相符合 .

Threshold Voltage Model for a Fully Depleted SOI-MOSFET with a Non-Uniform Profile

A novel approximation of the two-dimensional （2D） potential function perpendicular to the channel is proposed,and then an analytical threshold voltage model for a fully depleted SOI-MOSFET with a non-uniform Gaussian distribution doping profile is given based on this approximation. The model agrees well with numerical simulation by MEDICI. The result represents a new way and some reference points in analyzing and controlling the threshold voltage of non-uniform fully depleted （FD） SOI devices in practice.

Peculiar Nonlinear Depletion in Double-Layered Gated Si-δ-Doped GaAs

The low-temperature measurement of Hall effect of the two-dimensional electron system in a double-layered gated Si-δ-doped GaAs is presented.A complex peculiar nonlinear dependence of the depletion on gate voltage is observed.The nonlinearity is also explained on the basis of the assumption that the double-capacity model consists of two δ-doped two-dimensional electron layers and a metallic gate,and the experimental result that the electron mobility is linear with the electron density on a log-log scale.

High activity and durability of carbon-supported core-shell PtPx@Pt/C catalyst for oxygen reduction reaction

Alloying Pt with transition metals can significantly improve the catalytic properties for the oxygen reduction reaction(ORR).However,the application of Pt-transition metal alloys in fuel cells is largely limited by poor long-term durability because transition metals can easily leach.In this study,we developed a nonmetallic doping approach and prepared a P-doped Pt catalyst with excellent durability for the ORR.Carbon-supported core-shell nanoparticles with a P-doped Pt core and Pt shell(denoted as PtPx@Pt/C)were synthesized via heat-treatment phosphorization of commercial Pt/C,followed by acid etching.Compositional analysis using electron energy loss spectroscopy and X-ray photoelectron spectroscopy clearly demonstrated that Pt was enriched in the near-surface region(approximately 1 nm)of the carbon-supported core-shell nanoparticles.Owning to P doping,the ORR specific activity and mass activity of the PtP_(1.4)@Pt/C catalyst were as high as 0.62 mA cm^(–2)and 0.31 mAμgPt–^(1),respectively,at 0.90 V,and they were enhanced by 2.8 and 2.1 times,respectively,in comparison with the Pt/C catalyst.More importantly,PtP_(1.4)@Pt/C exhibited superior stability with negligible mass activity loss(6%after 30000 potential cycles and 25%after 90000 potential cycles),while Pt/C lost 46%mass activity after 30000 potential cycles.The high ORR activity and durability were mainly attributed to the core-shell nanostructure,the electronic structure effect,and the resistance of Pt nanoparticles against aggregation,which originated from the enhanced ability of the PtP_(1.4)@Pt to anchor to the carbon support.This study provides a new approach for constructing nonmetal-doped Pt-based catalysts with excellent activity and durability for the ORR.

Comparative characteristics of yttrium oxide and yttrium nitric acid doping in ZnO varistor ceramics

The effect of different molar ratios of Y2O3 and Y（NO3）3 on the microstructure and electrical response of ZnO-Bi203-based varistor ceramics sintered at 1 000 ℃ was investigated, and the mechanism by which this doping improves the electrical characteristics of ZnO-Bi203-based varistor ceramics was discussed. With increasing amounts of Y（NO3）3 or Y2O3 in the starting composition, Y2O3, Sb204 and Y-containing Bi-rich phase form, and the average grain size significantly decreases. The average grain size significantly decreases as the contents of rare earth compounds of Y（NO3）3 or Y2O3 increase. The maximum value of the nonlinear coefficient is found at 0.16% Y（NO3）3 or 0.02% YaO3 （molar fraction） doped varistor ceramics, and there is an increase of 122% or 35% compared with the varistor ceramics without Y（NO3）3 or Y2O3. The threshold voltage VT of Y（NO3）3 and Y2O3 reaches at 1 460 V/mm and 1 035 V/ram, respectively. The results also show that varistor sample doped with Y（NO3）3 has a remarkably more homogeneous and denser microstructure in comparison to the sample doped with Y2O3.

Nonlinear analysis of nano-cluster doped fiber

There are prominent nonlinear characteristics that we hope for the semiconductor nano-clusters doped fiber. Refractive index of fiber core can be effectively changed by adulteration. This technology can provide a new method for developing photons components. Because the semiconductor nano-cluster has quantum characteristics, Based on first-order perturba- tion theory and classical theory of fiber, we deduced refractive index expressions of fiber core, which was semiconductor nano-cluster doped fiber. Finally, third-order nonlinear coefficient equation was gained. Using this equation, we calculated SMF-28 fiber nonlinear coefficient. The equation shows that new third-order coefficient was greater.

Promoting Effects of Pt on the Catalytic Performance of Supported NiB Amorphous Alloy Catalysts for Benzene Hydrogenation

A support(denoted AM) was prepared using pseudo-boehmite and mordenite.Ni-B and NiPtB amorphous catalysts were prepared on the support by the impregnation method followed by chemical reduction with a KBH4 solution.And the catalysts were characterized by X-ray diffraction(XRD),environment scanning electron microscope(ESEM),inductively coupled plasma(ICP),H2-temperature programmed reduction(H2-TPR),differential thermal analysis(DTA),and BET.Benzene hydrogenation was used as a probe reaction to evaluate the effect of addition of small quantities of Pt on the NiB/AM catalyst.The results show that Pt can promote the reduction of NiO and the formation of active sites,leading to smaller catalyst particles and better dispersion of active metal particles on the support.The catalytic activity,sulfur resistance and thermal stability were remarkably improved by Pt doping of the NiB/AM catalyst.

氧化物稀磁半导体的本征铁磁性及其应用

电子具有电荷和自旋两个重要属性，传统的半导体器件仅利用了电子的电荷属性，稀磁半导体材料可以同时利用电子的电荷和自旋属性，成为未来半导体自旋电子器件的关键材料之一。人们期望通过对稀磁半导体材料的研究获得具有非易失、多功能、超高速和低功耗等特性的半导体自旋器件，这对材料和信息技术领域都将是一场质的革命。

Efficient and stable non-doped deep-blue organic light emitting diode based on an anthracene derivative

A new anthracene derivative 9,10-bis[3,5-di(4-tert-butylphenyl)phenyl]anthracene (BPPA) was synthesized via Suzuki coupling reaction and characterized by 1H NMR spectrum,mass spectrum,and elemental analysis.BPPA exhibits deep-blue emission both in solution and in solid thin film.This compound has a non-planar structure that results in high thermal stability and the phenomenon of polymorphism.The non-doped device based on this material shows stable deep-blue emission with the 1931 Commission international de I'Eclairage (CIE) coordinate of (0.15,0.05) under different applied voltages.The device exhibits the maximum external quantum efficiency of 2.2% at 14.9 mA/cm2 with luminance of 105 cd/m2.

Organic light emitting devices employing non-doped structure

A kind of efficient non-doped white organic light-emitting diodes(WOLEDs) were realized by using a bright blue-emitting layer of 4,4-bis(2,2-diphenylvinyl)-1,1-biphenyl(DPVBi) combining with red emitting ultrathin layer of [2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene]propane-dinitrile(DCM2) and green emitting ultrathin layer of 10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H, 11H(1)-benzopyropyrano(6,7-8-i,j)quinolizin-11-one(C545T) with different thicknesses of 0.05 nm, 0.10 nm and 0.20 nm. For comparing, a doped WOLED was also fabricated, in which C545 T and DCM2 are codoped into DPVBi layer to provide blue, green and red emission for obtaining white emission. The maximum luminance and power efficiency of the doped WOLED are 5 765 cd/m^2 at 16 V and 5.23 lm/W at 5 V, respectively, and its Commission Internationale de l'Eclairage(CIE) coordinate changes from(0.393 7, 0.445 3) at 5 V to(0.300 7, 0.373 8) at 12 V. When the thickness of the ultrathin C545 T layer in non-doped WLEDs increases, the emission luminance increases, but all non-doped devices are in the yellow white region. The device with 0.10-nm-thick C545 T has a maximum efficiency of 15.23 cd/A at 8 V and a maximum power efficiency of 6.51 lm/W at 7 V, and its maximum luminance is 10 620 cd/m^2 at 16 V. CIE coordinates of non-doped WLEDs with C545 T thickness of 0.05 nm, 0.10 nm and 0.20 nm are(0.447 3, 0.455 6),(0.464 0, 0.473 1) and(0.458 4, 0.470 0) at 8 V, respectively.

Porous nitrogen/halogen dual-doped nanocarbons derived from imidazolium functionalized cationic metal-organic frameworks for highly efficient oxygen reduction reaction

Heteroatom-doped carbon materials as alternative catalysts for oxygen reduction reaction(ORR)have drawn increasing attention due to their tunable chemical and electronic structures for achieving high activity and stability. However, there still remains a great challenge to fabricate porous heteroatoms dual-doped carbons with uniformly doping in a facile and controllable way. Herein,imidazole/imidazolium-functionalized metal-organic frameworks(MOFs) are employed as precursors and templates to achieve porous nitrogen and halogen dual-doped nanocarbons. Among these carbon materials, the as-prepared nitrogen/bromine dual-doped catalyst BrNC-800 exhibits the best ORR performance with a positive half-wave potential at 0.80 V(vs. RHE) in 0.1 mol L-1 KOH, which is comparable to the benchmark commercial 20 wt% Pt/C catalyst. BrNC-800 shows excellent long term stability and methanol tolerance.This work provides a facile approach to fabricate highly efficient heteroatoms dual-doped carbon catalysts for energy conversion.