The aligned Si nanowires growth using MW plasma enhanced CVD

New and simple modification of vapor-liquid-solid process for Si nanowires growth based on microwave plasma enhanced chemical vapor deposition that uses solid-state Si target as a source of Si atoms was developed. The method was temperature and pressure controlled evaporation of solid phase of Si source in hydrogen microwave plasma. Aligned growth of Si nanowires was performed in local electric field by applying of constant negative bias to substrate holder. Deposited Si nanowires were studied by scanning electron microscopy (SEM), Raman and photoluminescence spectroscopy. Correlation between photoluminescence spectra and Si nanowires properties were studied.     

Calculation of the standard heat capacities of crystalline oxides in the Fe-O-Ti system

Our earlier experimental studies of the solid-phase reduction of disseminated lump ores demonstrate that an oxide lattice transforms into a metal lattice via the saturation of the oxide crystal lattice by charged oxygen vacancies. Low-charge metal cations appear in the oxide crystal lattice, and they are related to oxygen vacancies by the condition of local electrical neutrality. As oxygen vacancies are accumulated (i.e., during reduction), the number of oxygen vacancy-low charge cation complexes in the initial oxide increases. The total composition of the oxide phase in the range of a crystal lattice of a certain type changes continuously from the initial oxide to the end product of reduction, i.e., to the lower oxide or a metal. Therefore, it is necessary to determine the thermal characteristics of not only all possible stoichiometric compounds in the M-O system but also MO_x oxides of variable compositions. Equations for calculating the standard heat capacities of complex stoichiometric oxides and oxides of variable compositions in the Fe-O-Ti system are derived using a mathematical model developed earlier, and these characteristics are calculated.     

A 72-mW CMOS 802.11a direct conversion front-end with 3.5-dB NF and 200-kHz 1/f noise corner

A direct conversion 802.11a receiver front-end including a synthesizer with quadrature VCO has been integrated in a 0.13-/spl mu/m CMOS process. The chip has an active area of 1.8 mm/sup 2/ with the entire RF portion operated from 1.2 V and the low frequency portion operated from 2.5 V. Its key features are a current driven passive mixer with a low impedance load that achieves a low 1/f noise corner and an high I-Q accuracy quadrature VCO. Measured noise figure is 3.5 dB with an 1/f noise corner of 200 kHz, and an IIP3 of -2 dBm. The synthesizer DSB phase noise integrated over a 10 MHz band is less than -36 dBc while its I-Q phase unbalance is below 1 degree.     

Conduction band states of transition metal (TM) high-k gate dielectrics as determined from X-ray absorption spectra

This paper uses X-ray absorption spectroscopy to study the electronic structure of the high-k gate dielectrics including TM and RE oxides. The results are applicable to TM and rare earth (RE) silicate and aluminate alloys, as well as complex oxides comprised of mixed TM/TM and TM/RE oxides. These studies identify the nature of the lowest conduction band d^* states, which define the optical band gap, E_g, and the conduction band offset energy with respect to crystalline Si, E_B. E_g and E_B scale with the atomic properties of the TM and RE atoms providing important insights for identification high-k dielectrics that meet performance targets for advanced CMOS devices.     

Wear Resistance of Coatings from Self‐Fluxing Alloys after Laser Doping under Dry Friction Conditions

The wear resistance of Ni–Cr–B–Si–C coatings after laser treatment with a doping covering under dry friction conditions has been investigated. The microstructure of coatings after fusion by a gas burner and a laser beam and the roughness and waviness parameters of the friction surfaces before and after wear have been investigated.     

Generalized Nakagami-m phase crossing rate

This paper provides simple, exact, new closed-form expressions for the generalized phase crossing rate of Nakagami-m fading channels. Sample numerical results obtained by simulation are presented that validate the formulations developed here. A special case of this formulation is the Rayleigh case, whose result agrees with that obtained elsewhere in the literature. In passing, several new closed-form results concerning the statistics of the envelope, its in-phase and quadrature components, phase, and their time derivatives are obtained.     

Automatic transport plane resource discovery mechanisms for ASON/GMPLS ring networks

In this letter, we propose two novel mechanisms which enable GMPLS LMP to cope with the automatic discovery of all-optical transport planes. The feasibility of our contributions and their performances are assessed by simulations as well as experimental results over the ASON/GMPLS CARISMA field-trial     

Modified modulation formats using time-varying phase functions

New modulation formats are presented that increase the transmission rate over that of conventional systems, without degrading the bit error rate (BER) and with minimal bandwidth variation. A time-varying function called an "extra phase variation function" (EPVF) is added to the discrete phase of conventional modulation formats such as M-PSK and QAM to transmit additional data bits. A receiver configuration is presented that allows the decoding of information represented by the discrete and extra phases. It is shown that in an additive white Gaussian noise (AWGN) channel, the BER performance of the bits carried by the discrete phase and the extra phase in the modified format improves over the BER of conventional modulation formats.     

变频调速技术在污水处理厂的应用

概述污水处理厂的一般工艺，简单介绍了风机、水泵等的节能特点，介绍了变频调速装置在污水处理厂各处理工段的应用。