A transmit/receive IF chip set for WCDMA mobiles in 0.35 /spl mu/m CMOS

An implementation of the IF section of WCDMA mobile transceivers with a set of two chips fabricated in an inexpensive 0.35-/spl mu/m two-poly three-metal CMOS process is presented. The transmit/receive chip set integrates quadrature modulators and demodulators, wide dynamic range automatic gain control (AGC) amplifiers, with linear-in-decibel gain control, and associated circuitry. This paper describes the problems encountered and the solutions envisaged to meet stringent specifications, with process and temperature variations, thus overcoming the limitations of CMOS devices, while operating at frequencies in the range of 100 MHz-1 GHz. Detailed measurement results corroborating successful application of the new techniques are reported. A receive AGC dynamic range of 73 dB with linearity error of less than /spl plusmn/2 dB and spread of less than 5 dB for a temperature range of -30/spl deg/C to +85/spl deg/C in the gain control characteristic has been measured. The modulator measurement shows a carrier suppression of 35 dB and sideband/third harmonic suppression of over 46 dB. The core die area of each chip is 1.5 mm/sup 2/.     

空气中^131I的取样和测量方法的研究

本文介绍一种气态和气载~(131)I 取样器。着重介绍了一种指数分布源的效率刻度方法,讨论了与取样有关的一些问题。     

微波辐射电镜生物样品制备方法研究

本文报道一种快速微波辐射电镜样品制备方法──水浴法，以及这个方法在动植物样品超薄切片制备中的应用。实验结果表明，水浴法使得样品可以接受相对较长时间的微波辐射而不致造成任何损伤，浸泡液和样品的温度控制简单而且准确，样品处理的结果内外均匀一致，超微结构保存优秀，完全可与常规制样法和Ｌｏｇｉｎ法的结果相媲美，而且在某些方面水浴法要优于常规法和Ｌｏｇｉｎ法。     

烷基化原料预加氢工艺应用分析

由于来自催化裂化装置的烷基化原料中所含有的丁二烯在烷基化反应中可生成重质油,使产品干点上升,辛烷值下降,并使酸耗增加.针对这种状况,齐鲁石化公司研究院和胜利炼油厂联合开发了QSH-01烷基化原料预加氢催化剂及其相应的工艺技术,来脱除原料中丁二烯.笔者对该工艺技术及其应用作了阐述,并对该技术的应用前景作出分析.     

Computation of Microwave Attenuation on Coplanar Waveguide with Conformal ADI-FDTD Method

A novel Conformal Finite-Difference Time-Domain based on Alternating-Direction Implicit Method(ADI-CFDTD) used to calculate the microwave attenuation on coplanar waveguide(CPW) with complicated cross-section up to 200GHz is presented. This ADI-CFDTD algorithm is the combination of conformal algorithm dealing with the deformed cell with ADI-FDTD, and has unconditionally stable. The difference equations are derived from the Faraday's and Ampere's law. To validate its accuracy and efficiency, as an example, a CPW fabricated on lithium niobate is proposed. Numerical results demonstrate that this new ADI-CFDTD algorithm has more accuracy than that of quasi-static and CFDTD and shows good agreement with experiment data. When frequency is up to millimeter wave band the radiation loss is not negligible in total power loss.     

空气井测井响应现象分析与探讨

空气钻井作为一种新的钻井技术已在四川油田川东地区的zbl井首次投入使用。2003年2月1日，四川测井公司数控分公司对该井进行了测井施工作业，采集了合格的井径、自然伽马、补偿声波、补偿中子、补偿密度和深浅双侧向资料。针对空气井测井中出现的现象进行了分析与探讨，旨在为今后空气井测井系列的选择与解释奠定基础。     

单井注水吞吐在塔河油田的应用

在塔河油田开发生产过程中，个别油井在修井作业中出现先漏后喷的现象。在修井完成后，产量较前期有大幅增加。针对这类油井进行单井注水吞吐采油试验，研究发现钻遇定容封闭性油藏的油井适合单井注水吞吐开采。一方面利用油水重力分异，抬升油水界面，增加采出量；另一方面注水补充地层能量，恢复地层压力。该方法在塔河油田实际应用中，取得了较好的效果和较高的经济效益，也为提高定容封闭性油藏油井的采收率提供了一个较好的方法。     

Development of composite tissue scaffolds containing naturally sourced mircoporous hydroxyapatite

The aims of this work were to investigate the conversion of a marine alga into hydroxyapatite (HA), and furthermore to design a composite bone tissue engineering scaffold comprising the synthesised HA within a porous bioresorbable polymer. The marine alga, Phymatolithon calcareum, which exhibits a calcium carbonate honeycomb structure, with a natural architecture of interconnecting permeable pores (microporosity 4–11 μm), provided the initial raw material for this study. The objective was to convert the alga into hydroxyapatite while maintaining its porous morphology using a sequential pyrolysis and chemical synthesis processes. Semi-quantitative XRD analysis of the post-hydrothermal material (pyrolised at 700–750 °C), indicated that the calcium phosphate (CaP) ceramic most likely consisted of a calcium carbonate macroporous lattice, with hydroxyapatite crystals on the surface of the macropores. Cell visibility (cytotoxicity) investigations of osteogenic cells were conducted on the CaP ceramic (i.e., the material post-hydrothermal analysis) which was found to be non-cytotoxic and displayed good biocompatibility when seeded with MG63 cells. Furthermore, a hot press scaffold fabrication technique was developed to produce a composite scaffold of CaP (derived from the marine alga) in a polycaprolactone (PCL) matrix. A salt leaching technique was further explored to introduce macroporosity to the structure (50–200 μm). Analysis indicated that the scaffold contained both micro/macroporosity and mechanical strength, considered necessary for bone tissue engineering applications.     

激光角膜矫正术中所用激光波长的选择

用分光光度计测定了12例兔角膜和1例人角膜的吸收光谱,结果表明波长小于300nm的准分子激光和波长在1.88μm～2.64μm,2.36μm～40μm的激光,均可对角膜进行切割并可望用于激光角膜矫正术。     

Cr_2O_3对矾土－尖晶石耐火材料抗渣性的影响

以高铝矾土及预合成电熔ＭＡ砂为原料，制各了矾土－尖晶石耐火材料。对其加入铬精矿后的抗渣性进行了试验。结果表明，少量铬精矿的加入能形成尖晶石固溶体，提高制品的抗渣性能。