低

The dual-band differential LNA use Inductive source degeneration structure, a matching network is used for the LNA to develop dual-band. The micro-mixer use a matching network shunt and parallel LC elements to develop wide-band matching. The biasing method reduces the"voltage headroom" difficulties inherent to the Gilbert cell, and the mixer linearity can be improved using this biasing method "Charge -Injection"by accurate adjustment of the input MOSFET operating point. The complementary VCO based on 2.5GHz, and tuning output buffer to approach 2GHz/5GHz dual-band for dual-band down-converter with MMIC technology.

其中双频差动低杂讯放大器，本电路用Inductive Source Degeneration 架构，在匹配网上设计，使低杂讯放大器工作在个频带上达成双频带的效果；CMOS 微混频器上采用LC串联、并联电路做匹配，达到宽频匹配的效果，并加入了"Charge-Injection"的方法来改善"voltage headroom"的问题，并同时提高线性度的表现；互补式压控振荡器以2.5GHz为基频的振荡器为出发点，透过电路的调整，以期达成2.5/5GHz的双频带需求，能够完整达成双频带接收机系统。

The design of digital notch filters can be achieved through three steps:firstly,the design of analog lowpass filter; secondly,it is analog lowpass to analog band stop filter conversion;at last,using the bilinear transformation make the analog notch filters change into digital notch filters.

研究一种在Matlab语言环境下设计IIR数字陷波滤波器的方法，在数字陷波滤波器设计过程中，先进行模拟低通滤波器的设计，然后进行模拟低通/模拟带阻滤波器转换，最后采用双线性变化法将模拟陷波滤波器转化成数字陷波滤波器。

Sb can combine with Cu and P to form a low melting point compound which lowers the melting point of binary Cu-8P eutectic alloy by nearly 200℃. Bi and Cu can create compounds with low melting point(270℃) distributing at the boundaries and that is the reason why the melting point of (Cu-8P)-Bi is lower than that of binary Cu-8P eutectic alloy. The eutectic cluster can be refined with the addition of Fe, and that is the reason why the addition of Fe can decrease the melting point of Cu-8P alloy. Two means of decreasing the melting point of Cu-8P are found.

一定量的Sb与Cu， P形成低熔点相，从而大幅降低了Cu-8P合金的熔点，使其熔点降低近200℃；加入少量Bi后， Bi与Cu在共晶团晶界上形成熔点为270℃左右的低熔点化合物，且Bi的加入明显细化Cu-8P合金共晶团，从而使Cu-8P合金的熔点降低；加入Fe能明显细化Cu-8P合金的共晶团，使层片间距由8μm减为2μm以下，并使共晶团由层片状向短棒状转变，虽然Fe与Cu形成熔点为806℃的高温相，但Fe的细化作用使得Cu-8P合金的熔点降低，但降低幅度不大。

The binomial deliverability equation can only be used to describe the high velocity non-Darcy filtering flow. For low permeability fracturing gas wells, due to low permeable property and high flow conductivity of the formation, the filtering flow laws of the formation are different from those before fracturing, and binomial deliverability equation can not be used for the flow condition of gas wells, therefore, new equation is needed.

二项式产能方程只能描述高速非达西渗流，对于低渗压裂气井，地层的低渗透性和裂缝的高导流能力使得其渗流规律已经和压裂前大不一样，二项式产能方程已无法描述气井的生产状况，必须建立新的方程。

With the high sensitivity of biomarker assays,the exposure levels and its biological effect in population exposed to low level carcinogens for a long time can be more directly measured,and the dose-effect relationship between biomarkers and a specific risk can be more accurately descripted The study on biomarker,which still stayed in primary stage,presented good prospect in the field of risk assessment on environmental health In this review,data are summarized on the role of biomarkers that are used for...

利用生物标志物高灵敏的特性，可以直接测量人群长期低剂量的暴露水平及其效应水平，能够较准确地估计生物标志物水平与特定危险性之间的关系，这方面的研究尚属起步阶段，但在环境健康危险度评价中具有很好的发展前景。对生物标志物的选择，其在低剂量致癌物暴露危险度评价中的作用，评价方法或途径及存在的问题进行了总结。

Emphasis was placed on CB-polymer interaction adjustment in order to control dispersion of carbon black aggregates in polymer matrix and obtain technical data for designing and manufacturing PTC products of practical values.

本论文在中山大学材料科学研究所有关工作的基础上，着重从聚合物基PTC材料的组成和加工工艺的角度，以炭黑填充单一低密度聚乙烯为参照体系，通过调节炭黑-聚合物基体之间的界面相互作用、控制炭黑的分散程度与分布状态，进而研究炭黑填充低密度聚乙烯/乙烯-乙酸乙烯酯共混物基PTC型复合材料，力图改善上述不足，为更好地了解这类PTC材料的结构-加工-性能之间的关系，设计和制造具有实际应用价值的PTC制品提供科学依据。

The research also reveals that it is difficult to get blocky metallic arsenic of industrial value by the method of electrodeposition.

因此在较低温度下实现无定形砷As粉末转晶形成块状金属砷As，具有重要的环境保护意义，同时，能源消耗较低。

The key features of Bluetooth technology are robustness, low power, and low cost.

蓝牙技术的主要特点是稳健、低功耗、低成本。

Bluetooth is a low cost, low power, short distance wireless communication technology.

蓝牙是一种低成本低功耗的短距离无线通信技术。

In this paper the control technology of low phosphorous and silicon steel in BOF is described.

本文结合生产实践，研究了转炉低磷低硅钢的控制技术，概述了冶炼控制过程，取得了预期的生产效果，有一定的借鉴和推广价值。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。