应用PIMS选油模型实施进口原油优化选购

应用AspenTech公司PIMS软件，模拟炼油企业生产经营过程，综合考虑原油成本、产品价格以及长岭分公司炼油厂加工流程特点和产品质量等要求，建立了适用于该厂的原油选购模型。利用该模型对该企业2002年第三季度进口原油品种进行优化选择，对综合效益好的原油实施采购。实际生产数据表明，该模型比较准确。     

Integrated carbon nanotube field emission differential amplifier: Modeling and measurement of the common-mode rejection ratio

A novel integrated vacuum field emission (VFE) differential amplifier (diff-amp) utilizing carbon nanotube (CNT) emitters has been developed. A dual-mask microfabrication process was employed to achieve a VFE diff-amp by integrating identical CNT VFE transistors with built-in split gates and integrated anodes. The identical pair of triode amplifiers was well-matched in their device characteristics. The measured ac small-signal characteristics of the diff-amp showed a common-mode-rejection ratio (CMRR) of ~ 320 (~ 50 dB). The proposed analytical model of the CMRR was verified to be in good agreement with the experimental data. The successful implementation of the CNT diff-amp demonstrates a new way to achieve temperature and radiation tolerant VFE integrated microelectronics.     

Preparation and Compressive Stress Effect of Polymer Matrix RE-Fe Giant Magnetostrictive Composite

Polymer matrix RE-Fe giant magnetostrictire composite （GMPC） was prepared using bonding and magnetic field forming technique, and magnetostriction of samples was measured for different compressive stress. The experimental results show thai there is certain compressive effect in GMPC. And the influence of compressive stress on magnetostriction of sample was investigated. It offers essential reference for application and device design of GMPC.     

推行岩土工程体制,降低工程造价与勘探成本

推行岩土工程体制,在确保给定的安全水平条件下达到综合造价最低的目的。     

ERP管理系统下的物料代码体系研究和应用

随着计算机及网络技术在现代企业生产经营管理中的广泛应用，特别是以网络为信息交流平台的企业CMIS、ERP和MRPII等管理系统的应用推广，使得企业生产经营的管理技术和理念相比传统管理的方式、方法也发生了根本性的变化。企业内外形成和交流的信息量成倍增加，组织生产经营信息逐步表现为操作流程规范化、信息应用集成化和信息环境复杂化的趋势，从而使得组织信息交流语言及接口的规范统一，标准化也日显重要。     

A Low-Power CMOS Linear-in-Decibel Variable Gain Amplifier With Programmable Bandwidth and Stable Group Delay

This brief presents a new circuit architecture for linear-in-decibel, constant-bandwidth variable gain amplifier (VGA). To obtain high linearity under low-voltage operation, this VGA is a closed-loop structure. In loop amplifier design, two techniques are applied: first, the loop amplifier is given finite input impedance. This arrangement keeps the VGA bandwidth constant under different gain setting. Second, a current-buffered compensation is applied for loop stability. Compared to the Miller compensation, this method achieves wider bandwidth. The prototype chip using 0.18-mum CMOS technology demonstrates that -10- to 20-dB gain and 0.5- to 30-MHz bandwidth can be programmed independently. The group delay difference within 30-dB gain control range is smaller than 1%. The total circuit dissipates 1.35 mA from a 1.8-V supply     

镍氢电池负极用低成本储氢合金的研究

研究了ABS型储氢合金在低Co含量条件下，随B组元替代元素Co，Al，Si等含量的变化对合金电化学性能的影响规律，同时研究了A组元中不同La／Ce比对合金电化学性能的影响情况。结果表明，随合金中Co含量的降低，合金的活化性能和放电容量得以改善，但合金的循环寿命下降也比较明显；在试验范围内，随Al元素的加入，合金的循环寿命得以改善，但材料的放电容量和活化性能均有所下降；随合金La／Ce比的降低，合金的放电容量略有下降，但其循环寿命和放电电压平台有较大提高。     

防治水泥稳定碎石基层沥青路面裂缝的措施浅析

水泥稳定碎石基层沥青路面裂缝产生的原因复杂 ,但非荷载型裂缝更为主要。防治水泥稳定碎石基层沥青路面的裂缝应该从设计和施工两方面考虑 ,其中由结构、材料组成设计 ,以及施工工艺出发控制水泥稳定碎石基层本身的收缩也是一项重要措施。