氟碳铈矿／直氟碳钙铈矿混层结构中新规则混层矿物的超微结构研究

用电子衍射和晶格像技术研究了钙稀土氟碳酸盐矿物中的氟碳铈矿（Ｂ）／直氟碳钙铈矿（Ｓ）混层结构，发现并确定了Ｂ＿４Ｓ＿４、Ｂ＿８Ｓ＿６、Ｂ＿１Ｓ＿６、Ｂ＿７Ｓ＿４和Ｂ＿２Ｓ＿１５种新规则混层矿物的对称性、晶胞参数及理论晶体化学式。根据所获得的高分辨晶格像真实而直观地揭示出该类Ｂ＿ｍＳ＿ｎ（ｍ＞ｎ）型新规则混层矿物的长周期有序堆垛结构特征及变化规律。     

Comparisons of PWM and one-cycle control for power amplifier with multilevel converter

Based on the concepts of cascade multilevel converters and one-cycle technique, comparisons are conducted to characterize the distortion of the pulsewidth modulation (PWM) and one-cycle control methods that were applied to converters. Simulation results for the different control schemes are obtained in PSIM software initially to see the effect of one-cycle control different from that of PWM control. Through the comparisons, the advantages and disadvantages are identified for each method. The one-cycle scheme is better than PWM control in reducing undesirable harmonics and tracing dynamic waveforms. Simulation and experimental results are also provided to verify the conclusions.     

用CPLD实现的高速数字图像存储转发装置

本文叙述了一种利用CPLD器件实现的高速数字图像存储转发装置,它被用于一个数字视频图像传输系统中.该装置的主要功能是将来自于CCD的数字图像数据存入大容量存储器中,并可以对数据进行编码,变换成PCM码输出.由于采用了VHDL语言设计,实现了分立器件难以实现的功能,提高了系统的可靠性,并可以方便地移植到各种CPLD器件中.     

YAG：Ce Phosphors for WLED via Nano-Pesudoboehmite Sol-Gel Route

The sub-micron sized YAG ： Ce phosphors were synthesized via a modified sol-gel method by peptizing nano-pesudoboehmite particulate. It is found that YAG phase from the dried gel powders appears at 1000 ℃ then the pure YAG phase exists at a relatively lower sintering temperature of 1400 ℃. The smaller sizes of phosphors in the ranges of 1 - 3 μm are obtained due to the contribution of seeding effects of nano-sized alumina particles to strengthen each step of the processes. Both the excitation and emission spectra of photoluminescence of the phosphor obtained at 1400 ℃ meet well with the spectroscopic requirements of the WLED phosphors.     

微波等离子体化学气相沉积的 a-Si∶H 性能研究

本文着重对微波等离子体化学气相沉积法高速沉积的 a-Si∶H 膜的物理性能进行评价研究.测量了沉积膜的光电性能、暗电导激活能、光禁带宽度、光吸收特性、沉积膜中悬键态密度以及氢含量等,并讨论沉积条件对膜性能的影响.结果表明,在沉积速率高达30～90(?)/s 情况下,膜的光电导(光照强度10~5Lux)与暗电导比值可达10~3～10~5,暗电导率从10~(-3)到10~(-11)((?)cm)~(-1),其激活能在0.23～0.88eV 之间(0～200℃温度范围内),光禁带宽度为1.40～2.20eV,氢含量约为2～20%.     

Improved coupled-mode theory for nonlinear directional couplers

An improved coupled-mode equation for nonlinear directional couplers (NLDC) with Kerr-like nonlinear media is proposed. The method is based on the generalized reciprocity relation in which two sets of field solutions satisfying Maxwell's equations are for the NLDC and for the isolated nonlinear waveguide. That leads to a reasonable result that all the coefficients in the coupled-mode equations, including the coupling coefficient, become power dependent. For the NLDC with a self-focusing or self-defocusing nonlinear material, the authors examine how the coupling coefficient, the coupling length, and the guided power depend on the input power in the range of coupling stronger than in previous reports. It is found that the critical power at which the coupling length becomes infinity does not increase as much with the two guides for the case of self-focusing media     

The Hardness of the Closest Vector Problem With Preprocessing Over$ell_infty$Norm

We show that the closest vector problem with preprocessing (CVPP) over lscr _infin norm (CVPP_infin) is NP-hard. The result is obtained by the reduction from the subset sum problem with preprocessing to CVPP_infin. The reduction also shows the NP-hardness of CVP_infin, which is much simpler than all previously known proofs. In addition, we also give a direct reduction from exact 3-sets cover problem to CVPP_infin     

2#板坯连铸机振动台故障分析及改造

论述了银山型钢有限公司炼钢厂2#板坯连铸机自投产以来其振动台存在的问题，根据实际情况分析论证并进行改造实施，实施后效果明显。     

En/Decoder for Spectral Phase-Coded OCDMA System Based on Amplitude Sampled FBG

A novel en/decoder for spectral phase-coded optical code-division multiple-access system based on amplitude sampled fiber Bragg grating (FBG) is proposed. Both equivalent chirp and equivalent phase shift are achieved by amplitude sampling. Compared with previous en/decoder based on step chirped FBG, it is easier to fabricate. The performance of the proposed en/decoder is verified by both numerical simulation and experimental demonstration.     

Geotechnical properties of the soft soil in Guangzhou College City

The paper describes some geotechnical properties of the soft soils in Guangzhou College City, China, which are difficult to both sample and test. Laboratory and in situ tests were carried out to assess the physical and mechanical indices of the soils. The data were statistically analyzed and linear regression undertaken such that equations could be developed by which the geotechnical properties of the soft soils can be predicted. The statistical validity of the degree of correlation confirmed that using these equations, the mechanical indices can be estimated from physical indices determined by routine testing.