The application of a biquadratic programming method to phase onlyoptimization of antenna arrays

Antenna array optimization by a biquadratic programming method is formulated with variable-phase (analog and digital) and constant amplitude excitation. The method can optimize an antenna performance index expressible as a ratio of Hermitian quadratic forms. Power gain optimization and least-squares pattern synthesis with a specified gain are illustrated. Linear, planar, and circular arrays with dipole or circular loop elements are optimized, taking mutual coupling effects between antenna elements into account. The method shows much more rapid convergence characteristics than the Rosenbrock (1960) and Fletcher-Power (1963) methods     

膛口气流速度测量

本文采用一种新的时间序列等离子体示踪方法测量武器膛口流场的高超音速非定常流速度——时间变化规律.详细介绍了使用该测速系统对7.62mm枪的测量结果。     

Ellipsometry as a means of mass-thickness determination in the earliest film growth stages

Gold was evaporated onto a fused silica substrate, and the normalized Stokes parameters S₁, S₂ and S₃, which represent the state of polarization of the light reflected from the sample, were determined in situ for films of average thickness less than a few monolayers with an automatic ellipsometer; the film mass m per unit substrate area was measured simultaneously with a torsion microbalance. It was found that $\text{ΔS = {(ΔS}{}_1\text{)}{}^2\text{+ (ΔS}{}_2\text{)}{}^2\text{+ (ΔS}{}_3\text{)}{}^2\text{}}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ changes linearly with m for light of wavelength λ well outside the absorption band of the film. For λ = 440 nm the sensitivity is comparable with that of a good torsion microbalance. Thus an automatic ellipsometer can conveniently be employed in the microgravimetry of submonolayer films.     

Proposals for wastewater treatment by applying flocculating activity of cross-linked poly-gamma-glutamic acid

Cross-linked poly-gamma-glutamic acid (C-L gamma-PGA) markedly purified polluted water collected from rivers and ponds by flocculation and precipitation. This effect of C-L gamma-PGA occasionally required pretreatment with polyaluminum chloride (PAC). Components of polluted water in rivers or ponds are generally thought to be clay minerals, microorganisms and chemical compounds. In this study, the flocculating activities of C-L gamma-PGA against suspensions of bentonite, diatomaceous earth, Escherichia coli and Mycrocystis aeruginosa, and against solutions of crystal violet and bisphenol A were investigated. The mode of action of C-L gamma-PGA is thought to be based on electrostatic interaction between flocculants, C-L gamma-PGA and PAC, and the surface of polluted water components, which may lead to neutralization of the zeta-potential of those components.     

Biosynthesis of poly-gamma-glutamic acid in plants: transient expression of poly-gamma-glutamate synthetase complex in tobacco leaves

Transient expression of genes coding for the poly-gamma-glutamate (gammaPGA) synthetase system (pgs) was investigated in tobacco plants. Three genes of the pgs, pgsA, pgsB and pgsC, were separately placed under the control of the CaMV 35S promoter and introduced into tobacco leaves via Agrobacterium infection. Synthesized gammaPGA in plant tissues was detected immunologically with mouse anti-gammaPGA antiserum which specifically reacts with gammaPGA on a nitrocellulose membrane. Confirmation of gammaPGA biosynthesis in the transient expression analysis in tobacco tissue indicates that subunits of pgs complex were expressed and reassembled in a functional form.     

An efficient maximum-likelihood-decoding algorithm for linear blockcodes with algebraic decoder

A new soft decoding algorithm for linear block codes is proposed. The decoding algorithm works with any algebraic decoder and its performance is strictly the same as that of maximum-likelihood-decoding (MLD). Since our decoding algorithm generates sets of different candidate codewords corresponding to the received sequence, its decoding complexity depends on the received sequence. We compare our decoding algorithm with Chase (1972) algorithm 2 and the Tanaka-Kakigahara (1983) algorithm in which a similar method for generating candidate codewords is used. Computer simulation results indicate, for some signal-to-noise ratios (SNR), that our decoding algorithm requires less average complexity than those of the other two algorithms, but the performance of ours is always superior to those of the other two