新型电子工业清洗工艺研究

本文报告了一种新型电子工业清洗工艺。用该工艺清洗过的硅片上的钠残留量低于常规ｃｍｏｓ／ｓｏｓ栅氧化工艺，去重金属离子的能力及对器件参数的影响与常规ｃｍｏｓ／ｓｏｓ栅氧化工艺相当。新型清洗工艺具有操作简单，价格低廉等优点，无毒，无腐蚀性，对人体无危害，对环境无污染。     

清洗后硅片表面的电子结构

介绍了一种含表面活性剂和螯合剂的新型半导体清洗剂和清洗工艺。利用红外吸收谱、X射线光电子谱和原子力显微镜等 ,把它和标准 RCA清洗工艺的清洗效果做了比较。测试结果表明 ,经清洗过的硅片表面主要是由硅、氧和碳三种元素组成 ,它们分别以 Si-O键、C-O键和 Si-C键的形式存在。两种清洗技术都在硅片表面产生氧化硅层 ,在硅片表面都存在有机碳污染 ,但新型半导体清洗工艺产生的有机碳污染少于标准 RCA清洗。在对硅片表面的粗糙化影响方面 ,新型半导体清洗技术清洗明显优于标准 RCA清洗技术     

一种对抗组网雷达的新型组网干扰技术

针对组网雷达技术的不断发展,提出了一种新式的针对组网雷达的干扰技术,详细介绍了这种新干扰技术的干扰原理,并对这种新干扰技术的布站模式和RCS的计算进行了阐述,最后从有效干扰功率密度的角度分析了该方法的干扰效果。通过理论分析和计算证明该技术具有很多优势和发展潜力。     

An Accurate and Cost-Effective Jitter Measurement Technique Using a Single Test Frequency

An accurate and cost-effective jitter measurement technique is proposed. The new technique uses only a single test with a high frequency input sine wave. Eliminating the need for a 2nd low frequency test, which is required in the conventional dual-frequency jitter test, provides significantly savings in both hardware and data acquisition time. The new technique is computationally efficient since it requires only one FFT together with some simple time domain computation. Furthermore, there are no nonlinear operations involved, hence avoiding errors inherently associated with such operations. Theoretical analysis, extensive simulation results and experimental results show that the proposed technique is cost-effective and achieves comparable test accuracy to that achieved by the conventional dual-frequency test. The new technique is reliable and robust to both harmonic and non-harmonic distortions. The algorithmic simplicity and the relaxed hardware requirement make the new technique potentially suited for built-in self test.     

Adaptive denoising of event-related functional magnetic resonance imaging data using spectral subtraction

A new adaptive signal-preserving technique for noise suppression in event-related functional magnetic resonance imaging (fMRI) data is proposed based on spectral subtraction. The proposed technique estimates a parametric model for the power spectrum of random noise from the acquired data based on the characteristics of the Rician statistical model. This model is subsequently used to estimate a noise-suppressed power spectrum for any given pixel time course by simple subtraction of power spectra. The new technique is tested using computer simulations and real data from event-related fMRI experiments. The results show the potential of the new technique in suppressing noise while preserving the other deterministic components in the signal. Moreover, we demonstrate that further analysis using principal component analysis and independent component analysis shows a significant improvement in both convergence and clarity of results when the new technique is used. Given its simple form, the new method does not change the statistical characteristics of the signal or cause correlated noise to be present in the processed signal. This suggests the value of the new technique as a useful preprocessing step for fMRI data analysis.     

Statistical estimation of average power dissipation usingnonparametric techniques

In this paper, we present a new statistical technique for estimation of average power dissipation in digital circuits. The present parametric statistical technique estimates the average power based on the assumption that the power distribution can be characterized by a preassumed function. Large error can incur when the assumption is not met. On the other hand, the existing nonparametric technique, although accurate, is too conservative and requires a large sample size in order to achieve convergence. For a good tradeoff between simulation accuracy and computational efficiency, we propose a new nonparametric technique using the properties of the order statistics. It is generally applicable to any type of circuit irrespective of its power distribution function. Compared to the existing nonparametric technique, it is much more computationally efficient since it requires a much smaller sample size to achieve the same accuracy specification. This new technique is implemented in the distribution-independent power estimation tool (DIPE). DIPE is empirically demonstrated to be more robust and accurate than the parametric technique     

一种新的低副瓣曲线阵数值综合方法

本文提出了一种新的低副瓣曲线阵数值综合方法。把曲线阵综合问题表述为约束非线性最优化问题,利用新直接方法求解它,即可求出使阵列的总方向图满足特定的副瓣电平指标,且具有尽可能高的方向性系数的激励和空间分布,文中主要给出了自由空间曲线阵综合的数学模型和计算结果,并给出了直线阵时新综合方法与Taylor分布的比较结果。新综合方法也适用于共形曲线阵综合问题。     

信息选择天线技术提高多天线系统信道容量的研究

在多天线系统中,将一部分信源信息映射于发射天线的选择,可以有效提高系统的传输效率.本文介绍了这种以信息选择发射天线的传输模式,并从信息理论的角度对其信道容量进行了分析、得到了解析表达式.理论分析的数值结果表明,与相同天线结构的随机选择发射天线系统相比,信息选择发射天线系统能够达到更高的信道容量.     

一种应用于探测器上的抗激光致盲新方法

基于Ｆｒａｎｚ－Ｋｅｌｄｙｓｈ效应．提出了一种新型的提高（ＨｇＣｄ）Ｔｅ探测器抗激光致盲能力的新方法，同时给出了利用这种新方法实现自动保护功能的简单方案．并通过实验加以验证．证明这一方法能够大幅度提高（ＨｇＣｄ）Ｔｅ探测器的抗激光致盲能力。     

激光冷却和捕陷气体原子或分子

本文综述了激光冷却和捕陷气体原子和分子的新技术.这项技术是激光应用的一个新的重要发展方向.它将为光谱学、原子频标和原子物理学的研究工作提供一个有效工具.估计会在其他研究领域也将有广泛应用.     

An efficient method for handling ectopic beats using the heart timing signal

The problem of analyzing heart rate variability in the presence of ectopic beats is revisited. Based on the integral pulse frequency modulation model and the closely related heart timing signal, a new technique is introduced which corrects for the occasional presence of ectopic beats. The correction technique, which involves the occurrence times of a certain number of beats preceding the ectopic beat, is computationally very efficient. From actual heart rate data, the results show that the new technique is associated with a much lower computational complexity (flops reduced by a factor of about 3000) than the original heart timing technique, while producing similar performance. It is also shown that the power spectrum and related clinical indices obtained by the new technique are more accurately estimated than by other methods.     

A frequency offset estimation technique for frequency-selectivefading channels

Rapid frequency offset estimation is required in burst communication systems. The performance of traditional open loop frequency estimation techniques is severely degraded by multipath propagation. We present a new data-aided technique for frequency offset estimation in the presence of strong multipath. The technique allows estimation of the frequency offset with no knowledge of the channel parameters. Results comparing the new technique with the maximum-likelihood estimation technique in a frequency selective Ricean fading environment are presented     

一种新的SAT问题预处理算法

提出了一项新的正向推理技术:对称扩展的一元子句推导(Symmetric Extended Unit Propagation)。与传统的一元子句推导技术相比,文中的方法通过在一元子句推导过程中添加对称的蕴涵关系从而能够推导出更多的一元子句。基于这项新技术实现了一个可满足性问题(SAT)预处理器Snowball。实验结果验证了该项技术的有效性,表明该预处理器Snowball能够有效地化简SAT问题的规模并减少解决SAT问题的时间。     

一种改进的非单调自适应新锥模型信赖域算法

对无约束优化问题提出了一种改进的非单调自适应信赖域算法。尽管传统的非单调技术存在着众多优点,但是也存在着易丢失最优解等缺点,为了克服这些缺点,文中提出了一种新的非单调技术,该技术是将已成功迭代点的函数最大值与当前迭代点的函数值相结合,充分利用了目标函数的信息,进一步将这种非单调技术引入到信赖域中,提出了一种改进的非单调自适应信赖域算法,在一定的条件下,证明了算法的收敛性,数值实验表明此算法的有效性。     

Parallel correlated double sampling technique for pipelined analogue-to-digital converters

A new correlated double sampling technique that avoids the additional thermal noise penalty is presented. The new technique employs a low- gain two-stage opamp with the second stage made up of multiple gain stages in parallel. The superior noise performance of the proposed technique to correlated double sampling is shown.     

一种气(Ga)-固(Al掺杂氧化物)-固(Si)掺杂新工艺

针对制造高压晶闸管p型杂质扩散工艺的不足,进行了开管式受主双质掺杂技术的研究.通过大量试验和工艺论证,研制成一种气(Ga) -固(Al掺杂氧化物) -固(Si)掺杂新工艺.经应用证明,该掺杂技术能明显提高器件的电参数一致性、综合性能和成品率,为电力半导体器件研究和生产开辟了一条可行的受主双质掺杂新工艺     

Direct digital frequency synthesizers with polynomial hyperfolding technique

A new approach to design the phase to sine mapper of a direct digital frequency synthesizer (DDFS) is presented. The proposed technique uses an optimized polynomial expansion of sine and cosine functions to achieve either a 60-dBc spurious free dynamic range (SFDR), with a second-order polynomial, or a 80-dBc SFDR, with third-order polynomials. Polynomial computation is done by using new canonical-signed-digit (CSD) hyperfolding technique. This approach exploits all the symmetries of polynomials parallel computation and uses CSD encoding to minimize hardware complexity. CSD hyperfolding technique is also presented in the paper. The performances of new DDFS compares favorably with circuits designed using state-of-the-art Cordic algorithm technique.     

Low-cost high-resolution time-domain reflectometry for monitoringthe range of reflective points

A new OTDR technique to interrogate the range of reflective markers in an optical fiber (or an electrical cable) is presented. The technique has been developed to monitor strain in sections of a fiber over gauge lengths of several meters. Signal-to-noise analysis shows that current OTDR systems do not fully exploit the spatial resolution theoretically available. The available resolution is explored with a new OTDR technique     

Modified algorithm for block truncation coding of monochrome images

Block truncation coding (BTC) is a recent technique used in the coding of image data. In the letter a modified technique for BTC coding of image data is presented which is algorithmically simple and hence easy to implement. This new technique uses only the first-order statistical information as `block overhead?. The new algorithm is shown to be optimum in the mean-square sense for a particular class of BTC algorithms. The letter presents the results of using the new algorithm for a typical image and compares the performance with that of the earlier algorithm for the same image.     

The Ellipsoidal Technique for Design Centering of Microwave Circuits Exploiting Space-Mapping Interpolating Surrogates

A new technique for design centering of microwave circuits is introduced. This technique exploits the space-mapping interpolating surrogate (SMIS) with a modified ellipsoidal technique. The design centering solution for microwave circuits is obtained with a small number of fine model evaluations and, hence, the number of electromagnetic simulations is greatly reduced. Practical and demonstrative examples are included to show the efficiency of the new technique.