交工35拖轮的增匹技术改造

本文介绍交工 35拖轮在由 2 94k W(40 0 HP)增匹改造为 44 1 k W(6 0 0 HP)的基础上 ,进而再达到 735 k W(1 0 0 0 HP)

Development of Turbocharger for Improving Diesel Engine Matching Performance

The two development ways of turbocharger technology to solve the problem of matching performance with diesel were presented. The ways of waste valve gate turbocharger and variable geometry turbocharger can solve the problem of engine’s low speed torque and achieve lower smoke level. Especially for variable geometry turbocharger, it covers all conditions of engine. It can not only improve the low engine’s speed torque and keep the power performance at high engine speed, but also cover wide engine speed performance that keeps lower fuel consumption and exhaust gas temperature in full load and part load matching. The results of theory analysis and experiment research showed that it’s the ideal solution to solve the matching problem of diesel engines.

CMOS Dual-Band Low Noise Amplifer

A CMOS dual-band low noise amplifer (LNA) design is presented.The purpose of th is work is intended to substitute only one LNA for two individual LNA's in dual -band transceivers for applications such as wireless local area network complying with both IEEE 802.11a and 802.11b/g.Dua l-band simultaneous input power and noise matching and load shaping are discuss ed.The chip is implemented in 0.25μm CMOS mixed and RF process.The measured pe rformance is summarized and discussed.

Mechanisms underlying aspirin-mediated growth inhibition and apoptosis induction of cyclooxygenase-2 negative colon cancer cell line SW480

AIM： To investigate the effects of aspirin （acetylsalicylic acid） on proliferation and apoptosis of colorectal cancer cell line SW480 and its mechanism. METHODS： Cyclooxygenase （COX）-2 negative colorectal cancer cell line SW480 was treated with aspirin at concentrations of 2.5 mmol/L, 5.0 mmol/L, 10.0 mmol/L for different periods in v/tro. Anti-proliferation effect of aspirin on SW480 was detected by 3-（4,5-dimeth- ylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay. Cell cycle and apoptosis were observed by flow cytometry （FCM）. Transmission electron microscope （TEM） was used for morphological study. Apoptosis-associated genes were detected by immunohistochemical staining and Western blotting. RESULTS： Aspirin inhibited SW480 proliferation and induced apoptosis in a dose- and time-dependent manner. Treatment with different concentrations of aspirin significantly increased the proportions of cells at the G0/G1 phase and decreased the proportions of cells at the S- and G2/M phases in a concentration-dependent manner. Aspirin not only induced apoptosis but also caused cell necrosis at a high concentration as well. After treatment with aspirin, SW480 cells displayed typically morphological features of apoptosis and necrosis under TEM, and increased the Bcl-2 expression in cells, but the expression of Bax was down regulated. CONCLUSION： Aspirin inhibits proliferation and induces apoptosis of SW480 cells. Its anti-tumor mechanism may arrest cell cycle and shift Bax/Bcl-2 balance in cells.

UHF power amplifier design in 0.35μm SiGe BiCMOS

A two-stage power amplifier operated at 925 MHz was designed and fabricated in Jazz' s 0.35μmSiGe BiCMOS process.It was fully integrated excluding the inductors and the output matching network.Under a single 3.3V supply voltage,the off-chip bonding test results indicated that the circuit has a smallsignal gain of more than 24dB,the input and output reflectance are less than- 24dB and-10dB,re-spectively,and the maximal output power is 23.5 dBm.At output power of 23.1 dBm,the PAE(poweradded efficiency)is 30.2%,the IMD2 and IMD3 are less than- 32 dBc and-46 dBc,respectively.The chip size is 1.27mm ×0.9mm.

SYMBOL-RATE ESTIMATION BASED ON TEMPLATE MATCHING RULES

For non-cooperative communication, the symbol-rate estimation of digital communication signal is an important problem to be solved. In this letter, A new algorithm for the symbol-rate estimation of single-tone digitally modulated signal (i.e. MPSK/QAM) is proposed. Firstly a section from the received signal is cut as the template, and then the signal is matched sectionwise by making use of the signal selfsimilarity. So a signal con- taining the information of symbol jumping is got, and the symbol-rate can be estimated by DFT (Discrete Fou- rier Transformation). The validity of the new method has been verified by experiments.

Matching between mechanics and thermodynamics among 4 individual strokes in a 4-stroke engine by non-circular gear mechanism

The relationship between engine mechanics and thermo-dynamics has been investigated by means of numerical simulation.The inherent mismatching between the mechanical behaviors and the thermodynamic process in internal combustion engine is identified,which is believed to be one of the important limiting factors of energy efficiency for conventional engines available in the current market.An approach for engine efficiency improvement through optimal matching between mechanics and thermodynamics(OMBMT)is proposed.An ideal matching model is defined and the conflicts due to the constraints among the mapping strokes in a 4-stroke engine are analyzed.A novel mechanical model is built for approaching optimal matching among all 4 individual strokes in a 4-stroke spark-ignition engine,which is composed of non-circular gears(NCG)and integrated with conventional slider crank engine mechanism.By means of digital mechanical model and numerical simulation,the matching gains among all 4 strokes are defined and calculated for quantifying the NCG engine efficiency improvement by comparing with a baseline engine.The potentials with the OMBMT implemented and the enhancements made by NCG mechanism for engines in terms of overall engine efficiency are reported.Based on the results achieved,it is recommended that the feasibility studies and the experimental validations should be conducted to verify the engine matching concept and effectiveness of the NCG mechanism engine model proposed,and the engine performance and NCG design parameters should be further optimized.

Theoretical analysis of stimulated polariton scattering from the A_1-symmetry modes of KNbO_3 crystal

Stimulated polariton scattering(SPS) based on noncollinear phase matching scheme from the A_1-symmetry modes of KNbO_3 crystal is investigated for generating terahertz(THz) wave. Frequency tuning characteristics of THz wave by varying the phase matching angle and pump wavelength are analyzed. The expression of the effective parametric gain length under the noncollinear phase matching condition is deduced. Parametric gain and absorption characteristics of THz wave in KNbO_3 are theoretically simulated. The characteristics of KNbO_3 for parametric oscillator(TPO) are compared with those of Mg O:LiNbO_3. The analysis results indicate that KNbO_3 is an excellent optical crystal for TPO to enhance the output of THz wave.