A Novel 0.72-6.2GHz Continuously-Tunable Delta Sigma Fractional-N Frequency Synthesizer

This paper presents a wideband Delta Sigma-based fractional-N synthesizer with three integrated quadrature VCOs for multiple-input multiple-output (MIMO) wireless communication applications. It continuously covers a wide range frequency from 0.72GHz to 6.2GHz that is suitable for multiple communication standards. The synthesizer is designed in 0.13-um RE CMOS process. The dual clock full differential multi-modulus divide (MMD) with low power consumption can operate over 9GHz under the worst condition. In the whole range frequency from 0.72GHz to 6.2GHz, the maximal tuning range of the QVCOs reaches 33.09% and their phase noise is -119d8/Hz similar to 124d8/Hz @1MHz. Its current is less than 12mA at a 1.2V voltage supply when it operates at the highest frequency of 6.2GHz.

A Simplified Soft-output QRD-M MIMO Detector

In this paper, a low-complexity soft-output QRD-M detection algorithm is proposed for high-throughput Multiple-input multiple-output (MIMO) systems. By employing novel expansion on demand and distributed sorting scheme, the proposed algorithm can reduce 70% and 85% foundational operations for 16-QAM and 64-QAM respectively compared to the conventional QRD-M algorithm. Furthermore, the proposed algorithm can yield soft information to improve the bit error rate (BER) performance. Simulation results show that the proposed algorithm can achieve a near-NIL detection performance with less foundational operations

Simulation on Gain Recovery of Quantum Dot Semiconductor Optical Amplifiers by Rate Equation

The gain recoveries in quantum dot semiconductor optical amplifiers are numerically studied by rate equation models. Similar to the optical pump-probe experiment, the injection of double optical pulses is used to simulate the gain recovery of a weak continuous signal for the QD SOAs. The gain recoveries are fitted by a response function with multiple exponential terms. For the pulses duration of 10 ps, the gain recovery can be described by three exponential terms with the time constants, and for the pulse with the width of 150 fs, the gain recovery can be described by two exponential terms, the reason is that the short pulse does not consume lot of carriers.

Calculation of Light Delay by FDTD Technique and Pade Approximation

The time delay for light transmission in a coupled microring waveguide structure is calculated from the phase shift of the transmission coefficient obtained by Pade approximation with Baker's algorithm from FDTD Output. The results show that the Pade approximation is a powerful tool for saving time in FDTD simulation.

A Smart Frequency Presetting Technique for Fast Lock-in LC-PLL Frequency Synthesizer

This paper proposes a smart frequency presetting technique for fast lock-in LC-PLL frequency synthesizer. The technique accurately presets the frequency of VCO with small initial frequency error and greatly reduces the lock-in time. It can automatically compensate preset frequency variation with process and temperature. A 2.4GHz synthesizer with 1MHz reference input was implemented in 0.35 mu m CMOS process. The chip core area is 0.4mm(2). Output frequency of VCO ranges from 2390 to 2600MHz. The measured results show that the typical lock-in time is 3 mu s. The phase noise is -112dBc/Hz at 600KHz offset from center frequency. The test chip consumes current of 22mA that includes the consumption of the I/O buffers.

Observation of deep electron states in n-type Al-doped ZnS1-xTex grown by molecular beam epitaxy

Deep level transient spectroscopy (DLTS) technique was used to investigate deep electron states in n-type Al-doped ZnS1-xTex epilayers grown by molecular fiction epitaxy (MBE), Deep level transient Fourier spectroscopy (DLTFS) spectra of the Al-doped ZnS1-xTex (x = 0. 0.017, 0.04 and 0.046. respectively) epilayers reveal that At doping leads to the formation of two electron traps at 0.21 and 0.39 eV below the conduction hand. 1)DLTFS results suggest that in addition to the rules of Te as a component of [lie alloy as well as isoelectronic centers, Te is also involved in the formation of all electron trip, whose energy level relative to the conduction hand decreases a, Te composition increases.

辽东次生林土壤呼吸及主要组分分离与量化

土壤呼吸是森林生态系统碳循环的重要组成部分，对土壤呼吸的主要组分根系呼吸和土壤微生物呼吸进行分离并量化，对于了解土壤碳释放规律、估算生态系统土壤碳的年际通量以及预测气候变化条件下根系或土壤微生物对土壤碳释放格局的影响具有重要意义。本文采用挖壕法测定辽东山区蒙古栎林、杂木林和胡桃楸林的土壤表面CO2通量，并同步分析土壤水热因子及土壤有机质、N含量、根系生物量、土壤酶活性、土壤微生物生物量等。研究结果表明：（1）辽东山区次生林0-10cm土壤有机质含量为9.29-18.15%，全氮含量为0.43-0.90%，pH值为5.67-6.19；次生林生长季细根生物量平均为152.61- 447.79 g/m2，粗根生物量平均为255.42-507.42 g/m2，根系总量平均为540.93-955.22 g/m2；土壤酶活性季节变化明显，且具垂直分布特征，蒙古栎林的土壤转化酶、淀粉酶和脱氢酶活性最高，胡桃楸林最低，胡桃楸林过氧化氢酶活性相对最大；土壤微生物量碳、氮的季节变化呈明显的单峰曲线并与土壤温度相关，土壤微生物量碳氮之间具显著相关性（P<0.05）。（2）次生林土壤总呼吸、根呼吸和土壤微生物呼吸具明显的日、季变化规律，生长季根呼吸贡献相对较低，胡桃楸林根呼吸贡献率为34.0-34.8%，蒙古栎林为17.9-28.4%，杂木林为14.7-35.3%；土壤微生物呼吸贡献率为66.0-85.3%，高于根呼吸贡献率，说明辽东山区次生林土壤微生物呼吸决定土壤总呼吸的变化趋势。（3）土壤呼吸与地下5cm土壤温度呈指数函数关系，土壤总呼吸的Q10值为1.29-2.30，微生物呼吸的Q10值为1.28-2.09，根呼吸的Q10值为1.29-3.72；土壤总呼吸、微生物呼吸、根呼吸与土壤含水量均无明显相关关系；蒙古栎林根呼吸与细根生物量显著相关，杂木林根呼吸与粗根生物量及根系总生物量显著相关，胡桃楸林根呼吸与根系生物量总量显著相关（P<0.05）；微生物呼吸与淀粉酶、转化酶、脱氢酶、过氧化氢酶均无显著相关性（除胡桃楸林与过氧化氢酶显著相关）；微生物呼吸与土壤微生物量碳、氮均呈显著线性相关关系（P<0.05）。（4）蒙古栎林土壤总呼吸、根呼吸、土壤微生物呼吸年际碳释放量分别为572.78、147.78和425.59 g C m-2a-1，杂木林分别为403.12、108.92、297.51 g C m-2a-1，胡桃楸林分别为519.47、173.75、345.72 g C m-2a-1；生长季和非生长季通过根呼吸释放的碳量均小于分解土壤有机质的微生物呼吸释放的碳量，非生长季次生林土壤碳释放量为39.21-152.04 g C m-2a-1，占全年呼吸总量的10-29%，说明冬季土壤碳释放量不能忽略。

肿瘤组织诊断用DPET探测器研制

依托中国科学院近代物理研究所的HIRFLCSR重离子冷却储存环,研制了肿瘤组织诊断用对扇形正电子断层影像(DPET,doublesectorpositronemissiontomography)探测器。介绍了肿瘤组织诊断用DPET探测器的晶体构形、传输光导选择、信号读出电路设计和电子学获取系统,给出了探测器探测单元的一些测试结果和结果讨论。

重离子与生物等效材料核反应产生的碎片剂量

采用55MeV/u40Ar17+离子束研究了其与生物等效材料作用在不同角度产生的核碎片的分布情况,同时对各角度碎片剂量给出了相对的估计量。结果表明,碎片的剂量应主要考虑0°角的贡献,而大角度的贡献可以忽略,这一结果为理论计算深度剂量曲线,考虑核碎片引起的剂量提供了实验依据。

输入信号时序鉴别方法与电路研究

简要介绍一种新的输入信号时序鉴别方法与电路。该电路的主要功能是对输入信号的时序进行鉴别和分拣,它可以鉴别出一个输入信号串中包含的各个脉冲的序号,并且产生与各个序号相对应的输出信号。可以鉴别的输人信号的序号为N=1,2,3,…,8。适用于多路时间幅度转换器(TAC)和多路时间数字转换器(TDC)系统,其输出信号可作TAC和TDC的停止信号。该电路输出信号的前沿tr≤3.2ns,传输延迟tpd≤20ns.

论林带防风效应结构参数及其应用

以防护林带经营管理的实际出发 ,提出了林带新的结构参数———地上生物体积密度 ,阐明了该参数在林带削弱风速中的物理意义 ,分析了它与过去常用林带参数 (透风系数 ,疏透度 )的关系 ,并举例说明了它在生产中的实际应用

蛭弧菌BDG-9质粒不稳定性研究

本文建立了研究难于单独连续培养的专性蛭弧菌质粒稳定性的方法体系。应用此方法体系发现并证明了在专性蛭弧菌BDG9中所含的质粒pSTⅠ存在着独特的质粒缺失现象,当蛭弧菌BDG9单独培养时,在通常决定质粒稳定性的复制功能和分配功能都正常的情况之下,随着细胞的传代,质粒pSTⅠ逐渐丢失,蛭弧菌的生长繁殖也逐渐停止,表明质粒pSTⅠ的存在对BDG9细胞单独生长有重要作用。

MAK-04型粘弹分析仪测试方法及实验条件的选择

本文介绍MAK－04型粘弹分析仪的测试方法和实验条件的选择方法，举例说明温度、扫描频率、振幅等条件对测试结果的影响。只有合理地选择测试方法和实验条件，才能得到满意的实验结果。

MAK－04型粘弹分析仪在复合材料动态力学性能测定中的应用

依据仪器原理和实验条件的限定，介绍了ＭＡＫ—０４粘弹分析仪在复合材料动态力学性能方面的应用。针对各种含不同聚合物的复合材料的特点进行分析测试，得出理想的分折数据。

Desempenho das cultivares de milho BRS Planalto e BRS Missões nas safras 2003/04 e 2004/05.

2006