闪光放射治疗(Flash-RT)在肿瘤治疗中的研究进展

闪光放射治疗(Flash-RT)作为放射治疗技术基础领域的关键性突破,可能引起放疗领域新的大变革。本文综述了Flash-RT在肿瘤治疗中应用和机制探索的最新研究进展。目前研究发现无论是电子束和光子Flash-RT还是质子FlashRT相较于常规剂量率放疗均可以降低对正常组织的损伤,但相关机制还未明确,包括但不限于氧耗竭、DNA损伤、细胞衰老、凋亡和免疫反应等。Flash-RT在肿瘤组织与正常组织损伤间的差异进一步减少了放疗的局限性,相较于常规放疗减少了不良反应和并发症,具有广阔应用前景。

生化黄腐酸对不同质地苏打盐碱土水盐运移特征的影响

为了探讨生化黄腐酸(biochemical fulvic acid,BFA)对不同质地(砂质壤土和壤质砂土)苏打盐碱土的改良作用机理,明确BFA对不同质地苏打盐碱土水盐运移特征的影响,该研究通过室内一维垂直入渗试验,对不同BFA施加量(0(CK)、1、2、4、8 g/kg)条件下土壤水盐运移特征、入渗模型参数和土壤八大盐分离子的变化特征进行了研究。结果表明:对于砂质壤土,当入渗至280 min时,与CK相比,BFA施加量为1、2、4、8 g/kg处理的累积入渗量分别减小了3.70%、10.19%、12.04%、25.00%,湿润峰深度分别减小了9.33%、17.00%、24.00%、27.33%;对于壤质砂土,当入渗至40 min时,与CK相比,BFA施加量为1、2、4、8 g/kg处理的累积入渗量分别减小了1.36%、10.51%、18.98%、29.83%,湿润峰深度分别减小了5.00%、11.33%、21.67%、31.33%。土壤水分入渗速率会随着BFA施加量的增加而减小,在0、5、10、15、20、25、30 cm土层深度,8 g/kg施加量处理的砂质壤土含水率分别高于CK处理11.43%、4.99%、8.54%、8.79%、9.02%、4.98%、-7.76%,而壤质砂土含水率分别高于CK处理4.76%、9.28%、6.18%、9.25%、8.05%、8.77%、-0.06%。Kostiakov和Philip模型均能较好地模拟土壤水分入渗过程,且随着BFA施加量的增加,吸渗率逐渐减小。然而施加BFA同样会增加不同深度土层的含盐量,在土壤钙离子、镁离子浓度较低的情况下,可能会使得土壤中富集钠离子。因此,施加BFA能够改变不同质地苏打盐碱土的水盐运移特征,为了防止施加BFA加剧土壤的次生盐碱化以及考虑施加BFA后的经济效益,该研究推荐BFA施加量为2~4 g/kg时对于不同质地苏打盐碱土具有更好的改良效果。

鼻咽癌同步推量同步放化疗与常规分割后缩野同步放化疗的疗效及毒性反应对比分析

目的对比分析鼻咽癌同步推量同步放化疗与常规分割后缩野同步放化疗的疗效及毒性反应。方法回顾性分析自2007年1月—2008年12月于我院接受同步放化疗后的90例鼻咽癌患者,其中同步推量组45例,常规分割后缩野组45例。对比分析两组患者的5年总生存率(Overall survival,OS)、无进展生存率(Progression free survival,PFS)、无局部区域复发生存率(Loco-regional recurrence-free survival,LRFS)以及毒性反应。结果同步推量组5年OS、PFS、LRFS分别为84.4%、75.6%、88.9%,常规分割后缩野组5年OS、PFS、LRFS分别为82.2%、71.1%、86.7%,两组OS、PFS、LRFS差异无统计学意义。常规分割后缩野组脑干、脊髓、腮腺放疗反应要轻于同步推量组。结论在调强放疗时代,应用同步推量同步放化疗和常规分割后缩野同步放化疗两种方式在预后方面无统计学差异,而常规分割后缩野组放疗毒性较轻。

风力发电机绝缘失效原因及改进措施

通过统计和调研,研究了风力发电机运行环境的特殊性和绝缘老化的应力类型,逐个探讨了高频脉冲、潮湿、温度交变、盐雾等因素对绝缘材料和绝缘寿命的影响。在此基础上,从材料选择、结构设计、工艺优化和质量管控等方面提出了适用于风力发电机绝缘系统可靠性提升的优化改进措施。通过上述措施,避免了绝缘缺陷产生概率,提高了质量缺陷的可探测性,确保了风力发电机长期安全、可靠运行。

Risk Assessment and Change Monitoring of Soil and Water Loss in Ruijin City Based on RS and GIS

The land use information extraction technology for the high-resolution remote sensing images of the Gaofen No. 1 satellite was construc-ted. According to the spectral, band, texture and shape attributes, land use types were divided, and the changing laws of land use types were ana- lyzed. Aftewards,according to the Table of Grading Standard of Sooil Erosion Intensity（SL190-96）,as well as vegetation coverage index NDVI slope, the risks of soil and water loss were assessed. Meanwhile, the level, scale, location and scope of changes in the risks of soil and water loss were monitored by using spatial visualization and spatial statistical techniques. The results showed that the area of areas without soil erosion and moderate soil erosion areas decreased obviously from 2015 to 2017, and the decreases were up to 22.929 3 and 13.626 3 km2 respectively. The ar-ea of mild soil erosion areas increased fast, and the increase reached 31.140 0 km2. The area of extremely strong soil erosion areas increased by 7.267 4 km2. In the city, moderate and strong soil erosion areas reduced, while extremely strong soil erosion patches increased fast, which was mainly related to road construction and construction and development of orchards. The extremely strong soil erosion areas were distributed in the shape of a banded loop, surrounded the suburbs of the city, and shrank towards the center of Ruijin City. The constructed technology to monitor the changes in land use and soil and water loss, as well as the changing laws of land use and soil and water loss provide the theoretical basis and plan-ning basis of soil and water conservation for urban planning departments and soil and water conservation departments.

新型HARDLOCK螺母防松管路接头制作及焊接工艺探讨

介绍了一种新型防松管路接头的工艺,解决了新安江水力发电厂机械过速保护装置在振动、过热环境下管路接头松动、渗漏油等问题,确保了机组安全可靠的运行。