Maximum likelihood estimation of parameters of several continuous and discrete failure distributions

A comprehensive quantitative treatment is presented for maximum-likelihood estimation of parameters of the following continuous and discrete failure distributions: (1) Exponential, (2) Gamma, (3) Weibull, (4) Normal, (5) Lognormal, (6) Extreme value, (7) Poisson, (8) Binomial and (9) Geometric.     

CIGS薄膜(InGa)2Se3-富Cu-富In(Ga)的演变

采用三步共蒸发工艺顺序沉积铜铟镓硒(CuInGaSe2,CIGS)薄膜.薄膜的厚度、组份、晶相结构分别由台阶仪、X射线荧光光谱仪(XRF)和X射线衍射仪(XRD)来表征.在(In,Ga)2Se3预制层-富Cu相的演变过程中,依次发生以下相变:Cu(In,Ga)5Se8、Cu(In,Ga)3Se5、Cu2(In,Ga)4Se7(或Cu(In,Ga)2Se3.5)、Cu(In,Ga)Se2(液相CuxSe).在富Cu相-富In(Ga)相的演变过程中,依次发生以下相变:Cu(In,Ga)Se2(液相CuxSe)、Cu2(In,Ga)4Se7(或Cu(In,Ga)2Se3.5)、Cu(In,Ga)3Se5、Cu(In,Ga)5Se8.对这两个演变过程中薄膜的生长机理和结构特性进行了讨论.     

Ca3(BO3)2的振动光谱分析

分别利用因子群对称分析法和位置群对称分析法对Ca₃(BO₃)₂晶体的振动模式进行了理论分析。Ca₃(BO₃)₂的晶格振动模式分为外振动和内振动模式,外振动模式为:3A_1g+4A_2g+7E_g+3A_1u+3A_2u+6E_u,内振动模式为：2A_1g+2A_2g+4E_g+2A_1u+2A_2u+4E_u。Ca₃(BO₃)₂晶体在布里渊区中心Γ点晶格振动的对称性分类为：5A_1g+6A_2g+11E_g+5A_1u+6A_2u+11E_u,其中声学模为：A_2u+E_u,拉曼活性光学模为5A_1g+11E_g,红外活性光学模为：5A_2u+10E_u,其余为非拉曼、非红外活性光学振动模。用高温固相法成功合成了Ca₃(BO₃)₂粉末,测量了它的室温Raman光谱,并利用群论分析的结果对谱图进行了讨论,指认了BO₃^3-基团的特征振动频率。     

Synthesis,characterization of the phenylquinoline-based on iridium(III) complexes for solution processable phosphorescent organic light-emitting diodes

A new series of highly efficient Ir(III) complexes, (DPQ)₂Ir(pic-N-O), (F₄PPQ)₂Ir(pic-N-O), (FPQ)₂Ir(pic-N-O), and (CPQ)₂Ir(pic-N-O) were synthesized for phosphorescent organic light-emitting diodes (PhOLEDs), and their photophysical, electrochemical, and electroluminescent (EL) properties were investigated. The Ir(III) complexes, including picolinic acid N-oxide (pic-N-O) ancillary ligand, are comprised with the various main ligands such as 2,4-diphenylquinoline (DPQ), 4-phenyl-2-(2,3,4,5-tetrafluorophenyl)quinoline (F₄PPQ), 2-(9,9-diethyl-9H-fluoren-2-yl)-4-phenylquinoline (FPQ) and 9-ethyl-3-(4-phenylquinolin-2-yl)-9H-carbazole. Remarkably, high performance PhOLEDs using a solution-processable (DPQ)₂Ir(pic-N-O) doped CBP host emission layer were fabricated to give a high luminance efficiency (LE) of 26.9 cd/A, equivalent to an external quantum efficiency (EQE) of 14.2%.The calculated HOMO–LUMO energy gaps for (DPQ)₂Ir(pic-N-O), (F₄PPQ)₂Ir(pic-N-O), (FPQ)₂Ir(pic-N-O) and (CPQ)₂Ir(pic-N-O) were in good agreement with the experimental results.     

A new method for preparing plan-view TEM specimen of multilayered films using focused ion beam

A new method is proposed for preparing plan-view specimens of a CeO(2)/Gd(2)Zr(2)O(7) multilayer on a metal substrate using focused ion beam milling. In the plan-view specimen, a membrane from the surface region of the CeO(2) to the Gd(2)Zr(2)O(7) layer was thinned to electron transparence so that the entire span of the multilayer can be observed in a single sample. The in-plane alignments of the CeO(2) layer and the Gd(2)Zr(2)O(7) layer were analysed using selected-area diffraction patterns (SADPs). The boundaries between the CeO(2) grains were also examined using SADPs.     

On estimating spectral moments in the presence of colored noise

Let{q^(1) (t)}, the signal, be a complex Gaussian process corrupted by additive Gaussian noise{q^(2) (t) }. Observations onp(t)q(t)andp(t) q^(2) (t)are assumed to be available wherep(t)is a smooth weighting function andq = q^(1) + q^(2). Using the Fourier transform of the samples ofp(t)q(t)andp(t) q^(2) (t), estimators are derived for estimating the mean frequency and spectral width of the unknown power spectrum of the unweighted signal process. The means and variances of these statistics are computed in general, and explicitly for nontrivial practical examples. Asymptotic formulas for the moment estimators as a function of the number of realizations, frequency resolution, signal-to-noise ratio and spectral width, and consistency of the estimators are some of the results that are discussed in detail.     

On the structure of linear codes with covering radius two and three

We obtain new bounds on l(m,r), the minimum length of a linear code with codimension m and covering radius r. All bounds are derived in a uniform way. We employ results from coding theory, some earlier results on covering codes, and combinatorial arguments. We prove the following bounds: l(6, 2)=13, l(7,2)=19, l(8,2)⩾25, l(9,2)⩾34, l(2m-l,2)⩾2^m+1 for m⩾3, l(14,2)⩾182, l(16,2)⩾363, l(18,2)⩾725, l(20,2)⩾1449, l(22,2)⩾2897, l(24,2)⩾5794, l(9,3)⩾17, l(10,3)⩾21, l(12,3)⩾31, l(13,3)⩾38     

Comparison of the pharmacological properties of rat Na(V)1.8 with rat Na(V)1.2a and human Na(V)1.5 voltage-gated sodium channel subtypes using a membrane potential sensitive dye and FLIPR

A novel, membrane potential sensitive dye and a fluorescence imaging plate reader (FLIPR) have been used to characterize the pharmacological properties of rat Na(v)1.8 voltage-gated sodium channels (VGSC) in parallel with rat Na(v)1.2a and human Na(v)1.5 VGSC subtypes, respectively. The sensitivity of recombinant Na(v)1.2a-CHO, Na(v)1.5-293-EBNA, and Na(v)1.8-F-11 cells to VGSC activators was subtype dependent. Veratridine evoked depolarization of Na(v)1.2a-CHO and Na(v)1.5-293-EBNA cells with pEC(50) values of 4.78 +/- 0.13 and 4.84 +/- 0.12, respectively (n = 3), but had negligible effect on Na(v)1.8-F-11 cells (pEC(50) < 4.5). Type I pyrethroids were without significant effect at all subtypes. In contrast, the type II pyrethroids deltamethrin and fenvalerate evoked direct depolarization of Na(v)1.8-F-11 and Na(v)1.5-293-EBNA cells. Deltamethrin potentiated the veratridine-evoked response in Na(v)1.8-F-11 cells by > or =20-fold, in contrast to a 相似文献   

Surface active buffered hydrogen fluoride having excellentwettability for ULSI processing

By incorporating selected hydrocarbon surfactants, a surface-active BHF (buffered hydrogen fluoride) has been tailored to achieve the following requirements: (1) the same etch rate as that of conventional BHF; (2) low contact angle; (3) nonsegregation; (4) nonfoaming; (5) low particulate count; (6) few impurities (possibility of purification); (7) low particulate adhesion on the wafer surface; (8) no surface residues; (9) excellent surface smoothness; and (10) high SiO ₂/Si etching selectivity. In order to satisfy these requirements, surfactants must satisfy the following characteristics: (1) good solubility in BHF; (2) hydrophilic property at the wafer surface, (3) nondecomposition in BHF; (4) nonreaction with BHF; and (5) sufficient lowering of contact angle at the critical micelle concentration (CMC). Aliphatic amines satisfy these requirements but have foaming problems. The requirements have been achieved using a binary surfactant system consisting of a combination of aliphatic amine and aliphatic alcohol or aliphatic acid     

Narrow-band systems and Gaussianity

The approach to Gaussianity of the outputy(t)of a narrow-band systemh(t)is investigated. It is assumed that the inputx(t)is ana-dependent process, in the sense that the random variablesx(t)andx(t + u)are independent foru > a. WithF(y)andG(y)the distribution functions ofy(t)and of a suitable normal process, a realistic boundBon the differenceF(y) -- G(y)is determined, and it is shown thatB rightarrow 0as the bandwidthomega_oof the system tends to zero. In the special case of the shot noise process begin{equation} y(t) = sum_i h(t - t_i) end{equation} it is shown that begin{equation} mid F(y) - G(y) mid < (omega_o/lambda) frac{1}{2} end{equation} wherelambda_iis the average density of the Poisson pointst_i.     

High-brightness blue organic light emitting diodes with different types of guest-host systems

We demonstrate high-brightness blue organic light emitting diodes (OLEDs) using two types of guest-host systems. A series of blue OLEDs were fabricated using three organic emitters of dibenz anthracene (perylene), di(4-fluorophenyl) amino-di (styryl) biphenyl (DSB) and 4,4''-bis[2-(9-ethyl-3-carbazolyl)vinyl]biphenyl (BCzVBi) doped into two hosting materials of 4,4''-bis(9-carbazolyl) biphenyl (CBP) and 2-(4-biphenylyl)-5(4-tert-butyl-phenyl)-1,3,4-oxadiazole (PBD) as blue emitting layers, respectively. We achieve three kinds of devices with colors of deep-blue, pure-blue and sky-blue with the Commission Internationale de L''Eclairage (CIE) coordinates of (0.16, 0.10), (0.15, 0.15) and (0.17, 0.24), respectively, by employing PBD as host material. In addition, we present a microcavity device using the PBD guest-host system and achieve high-purity blue devices with narrowed spectrum.     

Triple correlations

The (auto)triple correlation l⁽³⁾(t1, t2) is defined as the triple function integral, applied to the signal l(t) l⁽³⁾(t1, t2) = ∫ l(t)l(t + t1)l(t + t2) dt. The triple correlation l⁽³⁾(t1, t2) is less popular than the standard (double) correlation l⁽²⁾(t1) for several reasons: l⁽²⁾is sometimes easier to observe and to process, l⁽³⁾is small for many bipolar or complex signals, the mathematics associated with l⁽²⁾is better known. On the other hand, the triple correlation l⁽³⁾knows more about the signal l than does the ordinary autocorrelation l⁽²⁾. Also l⁽³⁾is in some ways more sensitive, in other ways less sensitive to noise, to bias drifts, etc. Hence, there are situations, where it is quite favorable to evaluate one-dimensional signals or two-dimensional pictures by means of their triple correlations. We will review the underlying mathematical tools and report on our projects where triple correlations were employed for studying laser pulse shapes, sound quality, halftone print statistics, mobility of bacteria, and astronomical speckle interferometry. We will mention also how others have used the triple correlation for ocean waves, engine noises, intensity interferometry, and other optical signal processing tasks.     

2010年通信技术和业务概貌预测──AT＆T贝尔研究院John Mayo院长演讲笔记

本文是贝尔研究院ＪｏｈｎＭａｙｏ院长１９９４年７月１１日在上海所作学术报告的听讲笔记。报告预测２０１０年通信技术和业务十大方面的概貌：（１）微电子集成芯片；（２）光子逻辑控制；（３）光纤传输容量；（４）语音信号处理；（５）传真和可视通信；（６）通信网结构进化，（７）个人无线通信；（８）计算机处理能力；（９）通信软件生产率；（１０）多媒体信息终端。     

非对称多模量子叠加态光场的等幂高次和压缩

根据量子力学中的态叠加原理,构造了由多模复共轭相干态|{zj(a)*}>q和多模复共轭相干态|{zj(b)*}>q的相反态|{-zj(b)*}>q的线性叠加所组成的非对称两态叠加多模量子叠加态光场|ψ(2)>q,利用多模压缩态理论研究了态|ψ1f(2)>q的等幂高次和压缩特性,结果表明: 1)当Rj(a)=Rj(b)和ψj(a)-ψj(b)=±(2k 1)π(k=0,1,2,3……),态|ψ1f(2)>q的两个正交相位分量均处于N-H最小测不准态的结果;2)当Rj(a)=Rj(b)=Rj和ψj(a)=ψj(b)=ψj,ψ态|1f(2)>q的等幂高次和压缩与文献3的结果相似; 3)当Rj(a)≠Rj(b)=Rj和ψj(a)=ψj(b)=ψj,且和满足一定条件时,无论qN为奇数还是偶数,态|ψ1f(2)>q的两个正交相位分量均可分别呈现周期性变化的等幂高次和压缩效应,但qN为奇数时的压缩深度大于qN为偶数时的压缩深度。     

Synthesis, optical and electroluminescent properties of novel polyfluorene/carbazole-based conjugated polyelectrolytes and their precursors

A series of novel aminoalkyl-substituted fluorene/carbazole-based main chain copolymers with benzothiadiazole (BTDZ) of different contents: poly[3,6-(N-(2-ethylhexyl)carbazole)-(9,9-bis(3'-(N,N-dimethyl-amino)propyl)-2,7-fluorene)-4,7-(2,1,3-benzothiadiazole)] (PCzN-BTDZ) were synthesized by Suzuki coupling reaction. Through a postpolymerization treatment on the precursor polymer, a corresponding quaternized ammonium polyelectrolyte derivatives: poly[3,6-(N-(2-ethylhexyl)carbazole)-(9,9-bis(3'-((N,N-dimethyl)-N-ethylammonium)propyl)-2,7-fluorene)-4,7-(2,l, 3-benzothiadiazole)] dibromide (PCzNBr-BTDZ) were obtained. It was found that devices from such polymers with high work-function metal cathode such as Al showed similar device performance to that by using low work-function cathode such as Ba, indicating the excellent electron injection ability of these polymers. The efficient energy transfer from fluorene-carbazole segment to the narrow band gap BTDZ site for both the neutral and the quaternized copolymers was also observed. The addition of BTDZ into the polymer main chain can also improve polymer LED (PLED) device performance. When poly(3,4-ethylenedioxythiophene) (PEDOT)/poly(vinylcarbazole) (PVK) was used as an anode buffer, the external quantum efficiency of the copolymer PCzN-BTDZ1 was 0.99%, which was much higher than the copolymer PCzN without the incorporation of BTDZ in the same device configuration.     

Comparison of GaAs grown on standard Si (511) and compliant SOI (511)

Gallium arsenide (GaAs) films were grown by molecular beam epitaxy (MBE) on a (511) silicon substrate and a compliant (511) silicon-on-insulator (SOI) substrate. The top silicon layer of the compliant (511) SOI was thinned to ～1000 Å. The five inch diameter SOI wafer was created by wafer bonding. The GaAs (004) x-ray diffraction (XRD) reflection showed a 25% reduction in the full width half maximum (FWHM) for GaAs on a compliant (511) SOI as compared to GaAs on a silicon substrate. Cross section transmission electron microscopy (XTEM) clearly indicates a different dislocation structure for the two substrates. The threading dislocation density is reduced by at least an order of magnitude in the compliant (511) SOI as compared to the (511) silicon. XTEM found dislocations and damage was generated in the top silicon layer of the compliant SOI substrate after GaAs growth.     

DECODING BEYOND THE BOUND OF THE COMPLEX-ROTARY CODE AND ITS DUAL CODE

The capabilities of decoding beyond the bound of the Complex-Rotary code (CRcodes) and its dual code are analyzed. It is obtained that the CR codes with normal error-correcting ability t = (p+1)/2 can correct (t+1)-errors up to C_(p~2+p(p+1))~(t+1)-p~(2Ct)_(2t+1) and itsdual code can correct (t_1+1)-errors up to C_(p~2+2tp)~(t_1+1)-2tpC_(p+1)~(t_1+1) where t_1=(p+1)/2-1 and pis a prime.     

High-resolution transmission electron microscopy study of Ca(3)Co(4)O(9)

The crystal structure of Ca(3)Co(4)O(9) was investigated using high-resolution transmission electron microscopy (HRTEM) and the image-simulation method. The c(*) was 10.8A and the b parameters were 4.56A for the Ca(2)CoO(3) block and 2.82A for the CoO(2) sheet. The [110] zone axis HRTEM images confirmed that Ca(3)Co(4)O(9) has a modulated layered structure with modulation. For the first time, the atomic positions of the Ca and Co atoms in the Ca(2)CoO(3) block were identified, corresponding to three rows of dark spots in the [110] direction. The observed HRTEM images for Ca(2)CoO(3) agreed well with the calculated images based on the structural model obtained by the Rietveld refinement method.     

Pharmacological analysis of the contractile role of M2 and M3 muscarinic receptors in smooth muscle

Muscarinic receptors expressed on smooth muscle cells are primarily of the M(2) and M(3) subtypes. The M(3) subtype triggers contraction through an interaction with G(q) proteins to stimulate phosphoinositide hydrolysis and mobilize Ca(2+). In contrast, activation of M(2) receptors modulates contraction by preventing relaxation or by potentiating M(3) receptor-mediated contractions, which enhances heterologous desensitization. These effects can be explained by the coupling of M(2) receptors to G(i) proteins that mediate an inhibition of adenylyl cyclase and calcium-activated potassium channels. The pharmacological antagonism of a response mediated through an interaction between M(2) and M(3) receptors has been shown to resemble the profile of the directly acting receptor (M(3)), primarily, and not that of the conditional receptor (M(2)). Evidence for a contractile role of the M(2) receptor has been obtained by inactivating its signaling pathway with pertussis toxin or by measuring contractile effects of muscarinic agonists after M(3) receptors have been covalently inactivated. Under these conditions, M(2) receptors have been shown to mediate an inhibition of the relaxant effects of agents, like isoproterenol, on the contractile effects of nonmuscarinic spasmogens. Muscarinic M(2) and M(3) receptor knockout mice are useful tools for exploring interactions between these receptors in smooth muscle.     

2,5,8,11-Tetra-Tertbutylperylene作为辅助掺杂剂的红色有机电致发光二极管(英文)

制备了采用9,10-di-(2-naphthyl)anthracene(ADN)作为主体,4-(dicya-nomethylene)-2-t-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran(DCJTB)作为红色发光中心,2,5,8,11-tetra-tertbutylperylene(TBPe)作为辅助掺杂剂的红光有机电致发光器件。4,4′,4″-tris[2-naphthyl(phenyl)amino]triphenylamine(2TNATA)用作空穴注入材料,4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl(NPB),tris-(8-hydroxyquinoline)aluminum(Alq3)用于空穴和电子传输。实验结果表明,掺有DCJTB的ADN也可实现红色发光,掺入TBPe作为辅助掺杂,可以提高该红光器件的效率,但几乎不改变器件色坐标。此外,2%TBPe(质量分数)作为辅助掺杂的器件表现出最佳的流明效率和最大升温速率。