跨世纪新一代通信网及其节点交换机技术定位问题

本文以新的视野和观念，讨论“定位”问题。文中描述了面临的新跨越以及跨世纪通信技术进化的总体特征，进而简要介绍了跨世纪全新结构的通信网，以及与之配套的节点交换机。本文把跨世纪的“定位”看作是一种机遇，建议超前于ＩＴＵ－Ｔ积极参与开发国际最新技术，推进我国通信行业于２０１０年进入世界领先行列。     

The recent trend of coronary surgery

As the use of PTCA (Percutaneous Transluminal Coronary Angioplasty) is progressively widespread, the indication of CABG (Coronary Artery Bypass Grafting) and its candidates are changing accordingly. At present the candidates for CABG have left main trunk disease or severe triple-vessel disease, which are difficult or too dangerous to undergo PTCA. We should also note the population of operative candidates is becoming gradually older than before. The results from CABG appear to be limited according to the random follow-up studies in Europe and United States. The recurrence of angina and myocardial infarction tends to happen after five years. Our follow-up study shows the same tendency as those studies abroad. In order to improve the long-term results of CABG, we recommend the use of arterial grafts such as internal mammary artery, opt to the complete revascularization, and follow the patients postoperatively maximum medical therapy. At the same time, we should stress the importance of deciding the best operative opportunity, and not hesitate to make the decision for reoperation if it became necessary. Older candidates have tendency to suffer from neurological or respiratory complications during the postoperative period. If the risk of those complications appears great from the preoperative examination, we must make efforts to prevent those complications and finish CABG in the shortest possible time. Recently the cases for emergent CABG are decreasing for unstable angina or acute myocardial infarction, because PTCA is more effective for a short time. Time appears to be the most limiting factor for emergent coronary revascularization. Therefore the indication of emergent CABG is left only for left main trunk disease or severe triple vessel disease with complete occlusion of two coronary vessels. As a conclusion, CABG should be considered as only a palliative therapy same as PTCA and other medical treatments. Therefore the treatment of ischemic heart disease must be constituted by a integrated strategy including PTCA and drug therapy arranged for each patient.     

GaAs-AlxGa1-xAs双势垒结构中电子共振隧穿寿命

采用转移矩阵和数值计算相结合的方法求解含时Schrodinger方程，计算了电子在双势垒结构中的构建时间和隧穿寿命. 结果表明：构建时间和隧穿寿命对于描述电子隧穿时间特性同等重要. 通过研究隧穿时间对结构参数的依赖情况发现，隧穿寿命随阱宽和垒厚的增加而迅速增大.     

Sonographic analysis of recurrent parotitis in children: a comparative study with sialographic findings

BACKGROUND: Patients with asthma show altered surface expression of the adhesion molecules CD11b and L-selectin on airway granulocytes compared with blood granulocytes. OBJECTIVE: To investigate whether this modulation is related to disease activity or due to transendothelial migration, we compared the CD11b and L-selectin expression on blood and induced sputum eosinophils and neutrophils between patients with asthma and normal subjects. METHODS: Eleven normal subjects (21-43 years), nine patients (21-34 years) with mild atopic asthma and 10 patients (20-47 years) with moderate to severe atopic asthma on regular treatment with inhaled steroids underwent sputum induction by inhalation of nebulized hypertonic saline (4.5%). CD11b and L-selectin expression on granulocytes from blood and DTT-homogenized sputum were analysed by flow cytometry. Eosinophils could be discriminated from neutrophils by using depolarized light scatter. Disease activity was assessed by baseline FEV1 and airway responsiveness to histamine (PC20). RESULTS: Sputum eosinophils showed higher expression of CD11b (P<0.001) and lower expression of L-selectin (P<0.001) compared with peripheral blood eosinophils. CD11b and L-selectin expression on eosinophils from blood or sputum did not differ between the three groups. Similar results were obtained for neutrophils. The PC20 in the patients with moderate-to-severe asthma was related to CD11b expression on blood (R=-0.92, P=0.001) and sputum eosinophils (R=0.75, P=0.02). CONCLUSIONS: Flow cytometry of induced sputum granulocytes from asthmatic as well as normal subjects is feasible. We conclude that the modulated expression of CD11b and L-selectin on airway granulocytes is not specific for asthmatic airway inflammation, but is probably the result of tissue migration per sé. This implies that CD11b and L-selectin expression on granulocytes in induced sputum cannot be used as marker of disease activity.     

Morphology and microstructure of electrochemically deposited calcium phosphates in a modified simulated body fluid

Calcium phosphates were deposited on a pure titanium plate for various loading times under 1.3 and 12.9 mA/cm2 in a modified simulated body fluid at 52-92 degrees C. The plate-like crystals formed under 1.3 mA/cm2 were identified to be octacalcium phosphate (OCP) and/or carbonate-containing apatite. OCP converted to carbonate-containing apatite with the elapsing time of the loading current. The needle-like precipitates formed under 12.9 mA/cm2 were identified to be carbonate-containing apatite crystals elongated parallel to the c-axis direction. The degrees of crystallinity of the deposits formed under 1.3 mA/cm2 showed the highest value around 72 degrees C, whereas those under 12.9 mA/cm2 increased with the electrolyte temperature. The carbonate content of the deposits decreased with the electrolyte temperature and the flow current. The degree of crystallinity of the electrochemically deposited calcium phosphates decreased with the carbonate content.     

Detailed analysis of high‐quality symmetrical octagonal spiral inductors on Si substrate

Research studies of symmetrical spiral inductors for silicon technology have become very important and challenging. In this article, we attempt to give a detailed explanation of how symmetrical spiral inductors help to improve the quality factor (Q) as compared to conventional nonsymmetrical inductors. The experimental results are presented to verify our theory. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005.     

First Tests of 6Li Doped Glass Scintillators for Ultracold Neutron Detection

We report the results of test measurements aimed at determining the performances of ⁶Li doped glass scintillators for the detection of ultra-cold neutrons. Four types of scintillators, GS1, GS3, GS10 and GS20, which differ by their ⁶Li concentrations, have been tested. The signal to background separation is fully acceptable. The relative detection efficiencies have been determined as a function of the neutron velocity. We find that GS10 has a higher efficiency than the others for the detection of neutrons with velocities below 7 m/s. Two pieces of scintillators have been irradiated with a high flux of cold neutrons to test the radiation hardness of the glasses. No reduction in the pulse height has been observed up to an absorbed neutron dose of 1 × 10¹³ cm⁻³.     

Rate adaptive video transmission over ad-hoc networks

A packet control mechanism via a cross-layer feedback to reduce bursts of packet drops for transmission of video over mobile multihop ad-hoc networks is presented. With this approach, the application layer would be capable of controlling the packet transmission flow in accordance with the multihop characteristics of the routing layer.     

多功能组合工艺装置

为了进一步简化油气集输、储运工艺流程，在设计上发展多功能组合的工艺装置，可减少厂房建筑、场区管网等工程量，为确保安全生产，建议在原多功能组合设备的基础上，选用国外的液下泵或潜油泵代替现有卧式输油泵与现有多功能设备组合，实现转油站油气分离、加热、缓冲、增压等工艺流程全面组合成一套多功能组合的工艺装置。     

吸收式1310nm～1550nm半导体激光器波长稳定的实验研究

文中对半导体激光器光电吸收稳频方法进行了基础研究和原理性实验，设计并制作以氪气（Kr）作吸收介质的光电吸收池，实现了波长为1310nm IgGaAsP DFB激光器工作波长的基本稳定。测试结果表明，激光器输出中心波长和峰值波长锁定在1308.279nm，且-20dB谱宽由稳频前的0.30nm变为0.12nm左右。