FAST灵敏度优化及“回照”方式分析

针对500 m口径球面射电望远镜的灵敏度优化和天顶角超过26.4°时溢损增大引起系统噪声温度上升的问题。文中采用调整馈源照明进行灵敏度优化,提出"回照"方式降低系统噪声管温度的方法。当馈源为高斯照明时,边缘照明约为-12^-14 d B时点源观测的灵敏度达到极大值。在天顶角为30°、35°和40°时,分别选取最佳回照角为15°、21°和26°时,望远镜的灵敏度分别提高了19%、48%和100%。

苦难与激情的人生回照——勃朗特三姐妹的创作意识

勃朗特三姐妹是英国文坛上的著名作家,她们都有自己独特的性格,从写作视角、取材范围和写作风格等方面无不折射出她们各自的百味人生。三姐妹的小说带给我们的不只是作品的惊喜,而且还有她们赋予作品的精髓与深刻的含义。从她们的小说中,折射出了女性已不再驻留于温柔的抗争和纯粹的逃避,而是开始奋力突围,努力彰显着真正的自我和人性的憧憬,是她们对生活的激情与苦难的人生回照:坚强与执著,女性的新诠释;回归自然,人性的永恒。

利用文本细节回照文本意蕴的教学策略

阅读教学中紧扣细节，引领学生以儿童独有的视角去探寻、去思考，能够丰厚学生的认知积淀。教学中，教师要引领学生视通万里，体悟文本细节的精深；通过认知转化，鉴赏文本细节的精妙；进行图文相融，品析文本细节的精致。

FAST馈源支撑系统位姿分配方法研究

为实现五百米口径球面射电望远镜(Five-hundred meter Aperture Spherical radio Telescope,FAST)馈源支撑系统馈源终端的高精度轨迹跟踪及防止馈源支撑索力超限,研究了馈源支撑系统星形框架和AB轴机构对目标终端位姿的分配算法。首先,根据馈源支撑系统机构特征,综合馈源舱的重心时变及其采用的回照策略,建立了带有馈源舱回照策略的考虑馈源舱重心时变的悬索牵引并联系统力学模型。然后,为解决AB轴机构与星形框架间的运动耦合问题,设计了两种馈源支撑系统位姿分配算法:优先保障六索索力均衡的位姿分配算法和优先保障馈源接收终端定位精度的位姿分配算法。最后,通过仿真对两种算法在馈源终端定位精度和索力分布情况两个方面的性能进行分析。仿真结果表明:前一算法能使六索索力分配均匀,但是引入了最大1.2°的馈源接收终端指向误差,已超出工程指向精度范围。后一算法的六索索力波动较大,但索力没超限或虚牵,能保证馈源接收终端的位姿,此算法满足工程需求。

RESEARCH ON COLOR CONSTANCY UNDER OPEN ILLUMINATION CONDITIONS

Color information plays a key role in the research fields of object recognition and image retrieval. However, the actual color varies by the conditions of illumination, especially the open natural daylight. Four different color constancy schemes are proposed in the paper to minimize the effects of open illumination conditions. (1) The color constancy scheme based on the image statistics is proposed, which includes the color cast detection and removal. (2) The color constancy scheme based on the color temperature curve is proposed, which combines Gaussian model with linear fitting to estimate color temperature curve. (3) The color constancy scheme based on the double exposure theory is proposed, which is able to reproduce a color image under typical illumination. (4) According to the concepts of supervised learning, the supervised color constancy scheme is proposed. The transformation of color values from unknown illumination to typical illumination is solved by improved Support Vector Regression (SVR).

Vascular endothelial growth factor polymorphisms and risk of lung cancer

Objective:We investigated the potential association between vascular endothelial growth factor(VEGF) polymorphisms and the risk of lung cancer.Methods:In the case-control study, we used PCR-RFLP technique to determine two VEGF genotypes-2578C/A and 936C/T in 171 lung cancer patients and 172 healthy controls for conformation, and constructed haplotypes of the two gene sites by PHASE1.0 software.Unconditional logistic regression model was used to analyze the statistical association of genontypes or haplotypes in the two groups adjusted by gender and age.Results:Compared with at least one-2578A allele, individuals with-2578CC genotype found associated with a significantly decreased risk of lung cancer P=0.001;adjusted odds ratio(OR), 0.391;95% confidence interval(95% CI), 0.226-0.686.Analyses stratified by gender showed that the combined-2578 CA and AA genotype were also associated with a significantly decreased risk of lung cancer.(P = 0.016;OR = 0.303;95% CI = 0.153-0.601 and P = 0.018;OR = 0.547;95% CI = 0.331-0.903, respectively).The distribution of the two haplotypes(936C/-2578C and 936C/-2578A) were significantly different between case-and-control groups(P = 0.016, OR = 0.317, 95% CI = 0.124-0.809 and P = 0.018, OR = 0.547, 95% CI = 0.331-0.903).Analyses categorized by tumor histology showed that Haplotype C-C was associated with a significantly decreased risk of adenocarcinoma compared with the reference haplotypes.(P = 0.004;OR = 0.237;95% CI = 0.090-0.627).Conclusion:These results suggest that the VEGF polymorphisms may be a critical factor for the risk of lung cancer.

“Four Sacral Needles” Therapy for Female Stress Incontinence

Objective： To make a retrospective control study of the curative effects of ＂Four sacral needles＂ method and conventional acupuncture therapy on female stress incontinence. Methods：A treatment group was treated by ＂Four sacral needles＂ method, in which four sacral points were electroacupunctured with special insertion of needles to excite the pudendal nerve and induce the rhythmic contraction of the pelvic floor muscles, thereby increasing the strength of the pelvic floor muscles and improving ability in urinary continence. A control group was treated by conventional acupuncture therapy, in which corresponding points were acupunctured according to syndrome-based classification. Results： In the 31 cases of the treatment group treated by ＂Four sacral needles＂ method, 100% symptom improvement occurred in 22（71.0% ）after an average of 21 treatments （3-63 treatments）. In the 34 cases of the control group treated by conventional acupuncture therapy, 100% symptom improvement occurred in 0 after 30 treatments. The curative effect was better in the treatment group than in the control group（p〈 0.01）.The curative effect improved with an increase in the number of treatments in the treatment group. Conclusion： ＂Four sacral needles＂ method is more effective than conventional acupuncture therapy in treating female stress incontinence.