论企业创汇统计

本文针对企业收汇、创汇指标在使用上的误解和混乱现象,首先从动态和静态两个方面给出了广义和狭义的企业收汇、创汇定义,然后具体讨论了企业创汇统计的对象、范围和基本原则,并对几个具体操作问题进行了探讨。     

“微藻-小白鼠”二元生态系统气体交换规律研究

为探讨“微藻-小白鼠”二元生态系统中氧气和二氧化碳交换规律,进一步评价空间微藻光生物反应器地面试验样机生产螺旋藻的能力,开展了螺旋藻和小白鼠的整合试验研究。将微藻光生物反应器和动物活动室组成气路闭环系统,试验期间连续监测系统中氧气和二氧化碳含量、小白鼠的活动状况、藻液pH变化以及藻体浓度含量等指标。试验结果表明,螺旋藻生长良好,系统闭环后促进了藻体的生长;从小白鼠的体征来看,小白鼠生活正常,但对小白鼠的生理影响还需深入研究。螺旋藻和小白鼠间能实现氧气和二氧化碳的完全交换,螺旋藻具有较强的吸收二氧化碳和放氧能力,可作为未来受控生态生保系统中的重要生物部件。     

一个基于XML的A2A数据交换系统

传统的数据交换系统缺乏可复用性与可扩充性。本文通过构建符合XML标准的业务流程规范,建立了一个通用的,易于扩展与维护的软件框架,并通过面向对象和构件技术提高数据交换系统的可复用性与可扩充性来适应数据交换标准不统一的现状,从而设计并实现了一种基于XML的企业内部电子数据交换系统。     

Study of fast atoms in molecular gas plasma via emission spectroscopy

Fast atoms are generated in reactions of ions with the molecular gas in laboratory and astrophysical plasma. In hydrogen they are observed in the emission spectra via Excessive line broadening. Energetic atoms also occur in astrophysical plasma in hydrogen, nitrogen and oxygen. The proposal here is that low pressure discharges can be used to simulate the phenomena in certain space plasma. In this study, we have used a special configuration of the electrode system, to obtain energetic atoms in plasma of three types of diatomic gases (H₂, O₂, N₂). Emission spectroscopy was used to detect the atoms and measure their velocity. Energy analysis was performed to obtain atoms’ distributions and evaluate the mean energy of atoms. This was compared to the potential energy available from the electric field. The field acceleration model, previously established for hydrogen, was extended to nitrogen and oxygen. We suggest, that the same method of analysis can be applied for astrophysical plasma spectrum.     

外燃波转子压力交换技术发展综述

外燃波转子利用端口启闭触发形成的非定常压力波来进行高效能量转换，具有广泛的应用前景。本文分析了外燃波转子内部流场的典型结构，回顾了国内外性能试验的重要成果，总结了其用于燃气轮机增压的优势与挑战。指出在端口渐开渐闭、转静间隙泄漏、离心力与科氏力加速、固体壁面传热等的影响下，流场结构呈现多维特征，且形成的泄漏损失占比最大；在模型试验条件下，可以获得15%~30% 的压力收益，以及70%~85% 的压缩效率；与燃气轮机联合使用时，具有通流自冷却、稳态性能突出、动态响应优异、尺寸效应不明显等优点，但需要攻克紧凑式总体结构设计、高性能外燃波转子设计、宽工况波系结构控制、低损失过渡段设计、复合损失抑制等难题。     

Investigation of pressure wave behaviors in the rotational speed effects on a pressure-exchange wave rotor

A wave rotor is suitable for compact and efficient pressure-exchange between gas flows.This work measured the circumferential pressure distribution of the rotor/stator interfaces and utilized a CFD method to simulate the unsteady pressure waves. The experimental and CFD results showed some slopes in the circumferential pressure distributions, and the slopes indicated the traces of specific unsteady pressure waves. Such traces varied regularly if the rotational speed varied within a range from-11...     

基于数字多波束星载多通道VDES设计

阐述了甚高频数据交换系统(VDES)系统产生背景,针对目前普遍存在的系统通信速率受限以及自动识别系统(AIS)时隙冲突问题,提出一种全双工射频通信频段设计方法和时隙冲突解决途径。通过采用多个射频通道以及多个波束合成,利用阵列天线和数字波束合成(DBF)技术,将卫星大覆盖范围划分为多个相互独立区域,缩小单个天线波束视场覆盖范围,减少单波束范围内船舶数量,能有效降低AIS信号时隙冲突。以600 km卫星轨道为例,介绍了8通道及8个波束DBF设计方法,对波束视场和天线增益等进行了仿真计算。结果表明:多波束可覆盖±42°视场角范围,单波束视场角最大为±14°。