目的:探讨Prowess5.1计划系统在鼻咽癌静态调强放疗(IMRT)计划设计时子野小数机器跳数(MU)的四舍五入取整对计划剂量学的影响。方法:选择33例病理诊断明确的鼻咽癌患者的IMRT计划纳入研究,分为两组计划:计划系统优化完成的原始计划组为P...目的:探讨Prowess5.1计划系统在鼻咽癌静态调强放疗(IMRT)计划设计时子野小数机器跳数(MU)的四舍五入取整对计划剂量学的影响。方法:选择33例病理诊断明确的鼻咽癌患者的IMRT计划纳入研究,分为两组计划:计划系统优化完成的原始计划组为P_(orig);对原始计划组的子野小数机器跳数四舍五入取整,做最终剂量计算后生成新计划组P_(new)。两组计划所有子野形状未改变,比较两组计划的MU变化及剂量学差异。结果:两组计划所有靶区的CI和HI相近,差异均无统计学意义;P_(new)组靶区覆盖率、PGTVnd的D_(98)、D_(95)、D_2、D_(mean)及PTV2的D_(98)、D_(95),P_(new)组均低于P_(orig)组(P<0.05),PGTV_(nd)、PTV_(nx)和PTV1的V_(100%)分别降低了1.807%、0.655%和1.258%;危及器官仅左颞叶的D_(mean)差异具有统计学意义(P<0.05);对于P1计划,单次P_(new)比Porig跳数增加了1.600,差异具有统计学意义(519.758±46.410 vs 518.158±46.693,P<0.05)。结论:Prowess5.1计划系统在制定鼻咽癌静态调强IMRT计划时,子野小数MU的微小变化会引起剂量学的变化,临床实践中应引起重视。展开更多
Plenty of inorganic nitrogen in wastewater can cause the eutrophication in water bodies, so it is an important task to remove nitrogen. Purification role was realized by absorption, filtration, depositon, evaporation,...Plenty of inorganic nitrogen in wastewater can cause the eutrophication in water bodies, so it is an important task to remove nitrogen. Purification role was realized by absorption, filtration, depositon, evaporation, nitrification and denitrification of microbes. Although the studies of Phragmites austrilis bed in the constructed wetland are popular, the purification performances of constructed wetland filled by saline-alkali soil substrate are less reported. In the paper, the purification efficiency of nitrogen with Phragmites austrilis bed in the constructed wetland filled by saline-alkali soil substrate was discussed through a simulation study. Results to date indicated that the first order plug flow model was adequate to describe the nitrogen removal. The experiment showed that the diminishing concentration of TN, NO 2-N, NO 3-N, NH 4-N were closely related to hydrological retention time (HRT), the correlation coefficient was R 2=0.98499, R 2=0.9911, R 2=0.89407 and R 2=0.95459, respectively. According to the data, the most suitable hydrological retention time (HRT) for this kind of constructed wetland should be determined to 4 days. In addition, the experiment showed the purification efficiency of nitrogen has very broad range and drastic vibration, TN (17%-79%), NO 2-N (33%-98%), NO 3-N(13%-93%), NH 4-N (28%-64%). The study will promote wetland’s design and operation procedures in large saline-alkaline soil areas.展开更多
The principle of optical fiber pressure sensing probe with common diaphragm and the method for stabilizing the laser diodes are described in this paper at first.Then we discussed the improvement in characteristics of ...The principle of optical fiber pressure sensing probe with common diaphragm and the method for stabilizing the laser diodes are described in this paper at first.Then we discussed the improvement in characteristics of the system by means of taking the techniques of reference light channel and ratio measurement.展开更多
The method of using multiplexing technique to realize the optically powered multiple detection system is presented. As this system adopted novel time and pulse width multiplexing techniques, reliable separation and er...The method of using multiplexing technique to realize the optically powered multiple detection system is presented. As this system adopted novel time and pulse width multiplexing techniques, reliable separation and error code correcting techniques, it realizes optically powered multiple channel and parameters detection, and successfully applied in the oil tanks for temperature, pressure, liquid level and reserve measurings.展开更多
文摘目的:探讨Prowess5.1计划系统在鼻咽癌静态调强放疗(IMRT)计划设计时子野小数机器跳数(MU)的四舍五入取整对计划剂量学的影响。方法:选择33例病理诊断明确的鼻咽癌患者的IMRT计划纳入研究,分为两组计划:计划系统优化完成的原始计划组为P_(orig);对原始计划组的子野小数机器跳数四舍五入取整,做最终剂量计算后生成新计划组P_(new)。两组计划所有子野形状未改变,比较两组计划的MU变化及剂量学差异。结果:两组计划所有靶区的CI和HI相近,差异均无统计学意义;P_(new)组靶区覆盖率、PGTVnd的D_(98)、D_(95)、D_2、D_(mean)及PTV2的D_(98)、D_(95),P_(new)组均低于P_(orig)组(P<0.05),PGTV_(nd)、PTV_(nx)和PTV1的V_(100%)分别降低了1.807%、0.655%和1.258%;危及器官仅左颞叶的D_(mean)差异具有统计学意义(P<0.05);对于P1计划,单次P_(new)比Porig跳数增加了1.600,差异具有统计学意义(519.758±46.410 vs 518.158±46.693,P<0.05)。结论:Prowess5.1计划系统在制定鼻咽癌静态调强IMRT计划时,子野小数MU的微小变化会引起剂量学的变化,临床实践中应引起重视。
文摘大家可能在最近的报刊杂志上看到过这样一条消息，就是说在2038年的时候有一些软件会出现诸如2000年的4年虫问题。我们最常用的软件TRW（2000）也存在着这个问题，那么究竟有没有办法把它的2038年问题破解呢？找出很早以前下载的trw 1.23版，在Windows 9x操作系统下，笔者使用Softice for 9x开始分析。
基金NortheastInstituteofGeographyAgriculturalEcology,CAS .(KZCX3 SW NA 13 )
文摘Plenty of inorganic nitrogen in wastewater can cause the eutrophication in water bodies, so it is an important task to remove nitrogen. Purification role was realized by absorption, filtration, depositon, evaporation, nitrification and denitrification of microbes. Although the studies of Phragmites austrilis bed in the constructed wetland are popular, the purification performances of constructed wetland filled by saline-alkali soil substrate are less reported. In the paper, the purification efficiency of nitrogen with Phragmites austrilis bed in the constructed wetland filled by saline-alkali soil substrate was discussed through a simulation study. Results to date indicated that the first order plug flow model was adequate to describe the nitrogen removal. The experiment showed that the diminishing concentration of TN, NO 2-N, NO 3-N, NH 4-N were closely related to hydrological retention time (HRT), the correlation coefficient was R 2=0.98499, R 2=0.9911, R 2=0.89407 and R 2=0.95459, respectively. According to the data, the most suitable hydrological retention time (HRT) for this kind of constructed wetland should be determined to 4 days. In addition, the experiment showed the purification efficiency of nitrogen has very broad range and drastic vibration, TN (17%-79%), NO 2-N (33%-98%), NO 3-N(13%-93%), NH 4-N (28%-64%). The study will promote wetland’s design and operation procedures in large saline-alkaline soil areas.
文摘The principle of optical fiber pressure sensing probe with common diaphragm and the method for stabilizing the laser diodes are described in this paper at first.Then we discussed the improvement in characteristics of the system by means of taking the techniques of reference light channel and ratio measurement.
基金This subject is subsidized by Hebei Education Commission
文摘The method of using multiplexing technique to realize the optically powered multiple detection system is presented. As this system adopted novel time and pulse width multiplexing techniques, reliable separation and error code correcting techniques, it realizes optically powered multiple channel and parameters detection, and successfully applied in the oil tanks for temperature, pressure, liquid level and reserve measurings.
