The nature of electron density enhancement over a wide altitude range during ionosphere heating experiments at EISCAT

During the course of ionospheric heating experiments, researchers at the European Incoherent Scatter Scientific Association (EISCAT) observed an apparent electron density enhancement. The enhancement extended over a wide range of altitudes, above the reflection altitude of the high-frequency pump wave. However, whether this enhancement actually corresponds to a true enhancement in electron density remains an open question. When the dispersion relation of ion acoustic waves is followed, the frequency ratio of the enhanced ion line to the background ion line suggests that the profile of the effective ion mass may have remained unchanged. Furthermore, the solar radio flux and ion drift velocity indicate no significant changes in the ion species and their densities. In conclusion, the electron density enhancement observed at EISCAT should not, in fact, be considered a true enhancement.

Comprehensive Benefit Evaluation Method of Mountain Flood Disaster Prevention and Control in Jiangxi Province Based on Matter-Element Extension Model

Taking the mountain flood disaster prevention and control project in Jiangxi province as the research object, the evaluation period is 2010-2015, and 29 evaluation indexes are selected from 7 aspects. In this paper, game theory is introduced to optimize the subjective and objective weights of the index, and the comprehensive weights are obtained by normalization. The results show that the eigenvalues of the grade variables of benefit evaluation decreased from 3.43 to 2.03, indicating that the project of mountain flood disaster prevention and control in Jiangxi province brings into play the benefits year by year, and the eigenvalues tend to decrease steadily after 2012, it is consistent with the changes of various engineering measures and non-engineering measures in the project.

A Case of Pelvic Floor Peritoneal Hernia after Miles’ Surgery

Objective: To investigate the causes and preventive measures of pelvic floor peritoneal hernia after transabdominal perineal radical resection of rectal cancer. Patients and Methods: A 68-year-old patient with progressive exacerbation of Miles’ postoperative intestinal obstruction was retrospectively analyzed. Conservative treatment was ineffective, and surgery was performed again. Surgery confirmed that the obstruction was caused by a pelvic floor peritoneal hernia. The original reconstruction peritoneal suture needle spacing was too wide, resulting in peritoneal hiatus. Results: The early postoperative intestinal obstruction in this patient was not caused by inflammatory intestinal obstruction, stenosis of stoma, and intestinal adhesion, but by the formation of pelvic floor peritoneal hernia. Conclusion: Pelvic floor peritoneal hernia should not be ignored in the early stage of intestinal obstruction after Miles’ operation. Improper suture during pelvic floor peritoneal reconstruction is the main cause of pelvic floor peritoneal hernia.

Incoherent scatter radar (ISR) observations of high-frequency enhanced ion and plasma lines induced by X/O mode pumping around the critical altitude

Analysis of Incoherent Scatter Radar(ISR)data collected during an experiment involving alternating O/X mode pumping reveals that the high-frequency enhanced ion line(HFIL)and plasma line(HFPL)did not appear immediately after the onset of pumping,but were delayed by a few seconds.By examining the initial behaviors of the ion line,plasma line,and electron temperature,as well as ionosphere conditions,we find that(1)the HFIL and HFPL were delayed not only in the X mode pumping but also in the O mode pumping and(2)the HFIL was not observed prior to enhancement of the electron temperature.Our analysis suggests that(1)leakage of the X mode to the O mode pumping may not be ignored and(2)spatiotemporal uncertainties and spatiotemporal variations in the profiles of ion mass and electron density may have played important roles in the apparent failure of the Bragg condition to apply;(3)nevertheless,the absence of parametric decay instability(PDI)cannot be ruled out,due to our inability to match conditions caused by the spatiotemporal uncertainties.

发展我国自主电波事业的若干建议

本文从国内外进展、政策与形势、问题与挑战等不同层面,分析了国家重大信息基础设施和应用系统对电波环境与电波传播的发展需求,分析阐述了电磁波领域发展面临的基础科学问题和关键技术,进一步探讨提出了“自主电波”的概念和内涵,包含三个层次,即:电波环境数字化,传播行为透明化,应用服务自主化。最后,提出了发展思路和建议,以期促进电波领域在新时代的跨越发展。

液相串联质谱在妇幼健康领域的应用与挑战

液相串联质谱技术具有高灵敏度、高特异性、高通量等特点, 可以准确、高效的检测维生素、胆汁酸、类固醇激素、代谢小分子等人体内水平的变化。液相串联质谱技术作为预防医学中筛查、诊断疾病的一种有效手段, 在妇幼健康方面广泛应用, 有效降低妇幼疾病的发生率, 提高我国妇幼人群的健康水平。目前质谱技术在我国面临着许多挑战, 但同时也有诸多机遇。本文将阐述液相串联质谱技术在妇幼健康领域的代表性应用方向, 并讨论临床实验室开展质谱检测遇到的主要一些问题。

A reliable opportunistic routing for smart grid with in-home power line communication networks

The topology of in-home power line communication(PLC) networks varies frequently, which makes traditional routing algorithms failure. To solve this problem, an end-to-end transmission time for remaining path(TTRP) metric-based opportunistic routing(TTRPOR) is proposed. Since a local broadcasting scheme is adopted, the algorithm can find the optimal path for forwarding packets in a dynamic PLC network. The closed-form of the outage probability for a PLC channel is derived to estimate the TTRP. It is proved that the average throughput can achieve maximum as the metric TTRP is utilized to sort candidate forwarding nodes.Numerical results show that the end-to-end throughput of networks with TTRPOR, outperforms that of the network adopting DSR and EXOR, especially for the case of varying-topology in-home PLC networks.