利用场耦合理论研究开放微波谐振腔

利用电磁场的等效原理，将一个开放微波腔等效于一个闭合边界微波腔（即封闭微波腔）和开放边界（即行波吸收边界）两部分，然后利用等效封闭微波腔的本征模式及其与开放边界的耦合，建立了关于开放微波腔模式（即模式场分布、频率、品质因子）的耦合方程组，其中开放边界为行波吸收边界.以X波段六腔渡越振荡管为例进行分析，将该振荡管等效为封闭微波腔和同轴输出结构两部分，用SUPPERFISH获得封闭腔的各个模式场分布及频率，然后根据封闭微波腔与开放边界的耦合，求得六腔渡越振荡管的工作模频率为9.25GHz，品质因子为115.2，与实验测量结果基本符合.     

基于SPA联系数的大连产业结构演化规律研究

SPA联系数是把研究对象各种测度联系起来加以系统性地描述、计算、分析的一种结构函数,其一般形式为a+bi+cj,用于城市第一产业、第二产业、第三产业相互联系和演化规律的研究有其合理和创新之处,其特点是把城市第一产业、第二产业、第三产业看成一个系统.用于大连产业结构演化规律研究后发现,大连市在1978~1999年20年间经历了稳定——剧烈调整——稳定这样三个阶段.在今后的10~20年间,对于第三产业的投资仍将处在首位.     

基于产业聚集的城镇化发展战略研究--对安徽省地级城市发展的思考

本文运用2000年至2003安徽省17个城市的统计资料，运用比较分析法和回归分析法，从城市规模、产业聚集、要素聚集以及综合经济实力等方面，对安徽省17个地级城市的发展进行了分析。主要结论认为，近几年来安徽省城市化发展步伐加快，城市规模、产业聚集与城市综合经济实力三者关系密不可分。但安徽省在城市化过程中存在着城市空间规模外延式扩张多，注重城市内涵效益的发展不够的问题，而城市发展的首要任务是产业的发展，带动要素的聚集，进而促进城市化水平的提高。安徽省城市发展的关键是建立有利于城市化发展的聚集机制和政策环境。     

各国信息产业综合水平的比较

使用因子分析法对世界 4 1个国家的信息产业发展作横向关联和时间纵向的综合水平比较 ,在定量分析的基础上 ,提出了自己的观点和看法。     

Urban rapid transit network capacity expansion

This paper examines a multi-period capacity expansion problem for rapid transit network design. The capacity expansion is realized through the location of train alignments and stations in an urban traffic context by selecting the time periods. The model maximizes the public transportation demand using a limited budget and designing lines for each period. The location problem incorporates the user decisions about mode and route. The network capacity expansion is a long-term planning problem because the network is built over several periods, in which the data (demand, resource price, etc.) are changing like the real problem changes. This complex problem cannot be solved by branch and bound, and for this reason, a heuristic approach has been defined in order to solve it. Both methods have been experimented in test networks.     

Development of a sequential injection anodic stripping voltammetry (SI-ASV) method for determination of Cd(II), Pb(II) and Cu(II) in wastewater samples from coatings industry

This paper describes the development and validation of a sequential injection (SI) anodic stripping voltammetry (ASV) method using the hanging mercury drop electrode for accumulation of the heavy metal cations Cu(II), Pb(II) and Cd(II). The method was applied to wastewater samples after proper acid digestion in open vessels to eliminate matrix effects. For a deposition time of 90 s at the flow rate of 10 μl s⁻¹, the detection limits of the method were 0.06, 0.09 and 0.16 μmol L⁻¹ for Cd, Pb and Cu, respectively. Under these conditions the linear dynamic range was between 0.20 and 9.0 μmol L⁻¹ and the sampling frequency was 30 analyses per hour. The relative standard deviation of the method was 3%(n=7) at the concentration level of 2.0 μmol L⁻¹. The accuracy of the method was evaluated by spiking the samples with known amounts of the metal cations, and by comparison with an independent analytical technique, the inductively coupled plasma atomic emission spectroscopy (ICP-AES). Average recoveries were around of 84%, and the results showed no evidence of systematic errors in comparison to the ICP-AES.     

产业转移下的海上丝绸之路沿线集装箱港口的投资决策研究

在产业转移背景下,考虑港口服务货运需求与刺激货运需求的双重功效,研究海上丝绸之路沿线产业承接地的港口投资建设问题。首先,在现实交通运输网络中加入虚拟链接构建超级网络,用以刻画制造业的转移、生产和运输过程。其次,建立制造业承接地港口投资决策优化模型,用运输阻抗、地价和工资三个内生变量描述港口投资、产业转移与区域经济之间均衡关系。模型以产业承接地港口收益最大为目标,确定承接地港口的投资规模及费率水平。最后,以斯里兰卡的科伦坡口为例进行数值分析,计算海上丝绸之路沿线港口需求与供给间正向反馈的数量关系及上确界,为优化沿线港口投资实现投资利益最大化提供依据。     

现代物流业与其相关产业灰色关联度研究——基于山西省的实证分析

结合山西省2002～2006年的相关行业生产总值增加值,运用灰色系统理论方法,得到山西省现代物流业与相关产业的灰色关联系数,按照关联度的不同排序,对山西省发展现代物流业提出了切实可行的政策建议.     

Untersuchung der Schwefelbilanz bei metallurgischen Prozessen unter Verwendung von 35S

Es werden Methoden und Ergebnisse der Untersuchung der Schwefelbilanz beim Krupp-Rennverfahren und beim Siemens- Martin-Prozeβ unter Verwendung von ³⁵S beschrieben. Die Markierungsverfahren für die Ausgangsstoffe werden angegeben.     

Estimation of N Absorption and Secretion by Digesta Exchange between 15N Labelled and Unlabelled Pigs

Abstract

Three female pigs (LW～30 kg) were fitted with re-entrant cannulas in the duodenum and the ileum and with bladder catheters. Animal No. 1 was labelled by continuous infusion of [¹⁵N]leucine via a catheter into the vena jugularis. After reaching a steady state in the level of endogenous N (4–5 d after beginning of the infusion) the digesta of the labelled animal No. 1 and the two unlabelled animals were exchanged in a 3 day experiment. During this time the course of transit rates of digesta, digesta N and ¹⁵N through duodenum and ileum as well as the proportion of endogenous N: exogenous N were estimated. Using these data it was possible to calculate the secretion and absorption rates of endogenous and exogenous N in the three segments of the digestive tract: mouth-duodenum, duodenum-ileum, ileum-anus and in addition the reabsorption (intestinal recycling) of the endogenous N during its passage through the gut could be computed.