基于甲亢临床指标的多维时间序列关联度分析

近年来,对临床医疗数据的挖掘分析越来越热,医疗数据中包含很多有价值的信息等待被挖掘。对基于时间序列的临床指标数据流进行关联度分析,从中发现临床指标相互之间变化趋势的相关性,对于开展精准医疗具有非常重要的价值。本文将高斯混合模型运用于临床医疗数据流的关联度分析中,提出关联支持度的方法来衡量指标之间的关联关系的强弱程度。最后通过分析100多位甲亢患者临床指标数据流,计算出各个指标对的关联支持度,得出各指标相互之间关联度的强弱关系。     

反溶剂重结晶法制备阿奇霉素超细粉体

采用反溶剂重结晶法进行了阿奇霉素微粉化实验研究.系统考察了药物溶液质量浓度、溶剂反溶剂比例、搅拌时间、干燥方式等因素对产品形貌和粒度的影响.得到较优的制备工艺条件为:药物溶液质量浓度0.2/mL、溶剂反溶剂体积比1:20及搅拌时间10min,可制备出平均粒径为270 nm的药物颗粒,经喷雾干燥可得粒径为2-5μm的阿奇霉素超细粉体.采用扫描电镜、比表面积测试、红外光谱分析和体外溶出实验对原料药及产品性质进行分析表征,分析结果表明,阿奇霉素超细粉体化学结构不变,且比表面积增大8倍,溶解速率明显提高.     

Image-quality metrics for characterizing adaptive optics system performance

Adaptive optics system (AOS) performance is a function of the system design, seeing conditions, and light level of the wave-front beacon. It is desirable to optimize the controllable parameters in an AOS to maximize some measure of performance. For this optimization to be useful, it is necessary that a set of image-quality metrics be developed that vary monotonically with the AOS performance under a wide variety of imaging environments. Accordingly, as conditions change, one can be confident that the computed metrics dictate appropriate system settings that will optimize performance. Three such candidate metrics are presented. The first is the Strehl ratio; the second is a novel metric that modifies the Strehl ratio by integration of the modulus of the average system optical transfer function to a noise-effective cutoff frequency at which some specified image spectrum signal-to-noise ratio level is attained; and the third is simply the cutoff frequency just mentioned. It is shown that all three metrics are correlated with the rms error (RMSE) between the measured image and the associated diffraction-limited image. Of these, the Strehl ratio and the modified Strehl ratio exhibit consistently high correlations with the RMSE across a broad range of conditions and system settings. Furthermore, under conditions that yield a constant average system optical transfer function, the modified Strehl ratio can still be used to delineate image quality, whereas the Strehl ratio cannot.     

半导体温差发电器的工作性能优化

应用有限时间热力学理论分析了半导体温差发电器的工作性能.推导了在内外均不可逆情况下发电器的输出功率和效率的表达式,并在此基础上重点讨论了发电器在外部条件变化时的性能,获得了一些有意义的结果.     

Proton Low-Field NMR Measurements on Crackers

We have shown that the signal obtained for crackers (3.5% water content) by low resolution NMR method using the CPMG sequence, described the relaxation of the protons of fat. For water content up to 7.1% the water signal is not seen by a CPMG sequence, the water has therefore a very short spin-spin relaxation time (T2 < 0.5 ms). However, that water modifies the mobility of protons of fat at solid-liquid interfaces. Protons exchangeable by deuterium affect neither the relaxation time of the short component (about 1 ms), nor its intensity. Between 7.1% and 14.8%, the water had a spin-spin relaxation time of about 1 msec and its signal was added to the short component of the fat. Thus, low resolution NMR could be used to follow the crystallization of fat in such samples after cooking.     

基于模式基因提取的多值编码遗传算法性能改善

本文通过模式基因的提取,即根据种群个体的基因值在种群中的统计量确定统计模式基因,然后通过对统计模式基因的测试搜寻模武基因,并将其在种群中进行传播,有效改变种群搜索的方向,改善多值编码遗传算法的搜索性能.以组合优化的多重选择背包问题为对象验证了本方法的有效性.     

高压超频凿击射流对空热器快速破堵技术研究

针对我国矿山坑口电站和大中型火力发电厂普遍存在的管式空气预热器大面积堵塞,严重威胁设备安全的现象,研究试制了一种高压水射流与机械结合的高速破堵系统,对电厂锅炉设备大修、安全运行和提高设备热效率具有重要意义。     

微型PSA制氧技术试验研究

研究了微型变压吸附(PSA)制氧时空气量、分子筛、吸附时间、吸附塔高径比等因素对产品气浓度和流量的影响.产氧量与空气量之比约为15~18,氧气收得率约为25%~30%.分子筛品种对制氧效率有重要影响,分子筛量与产氧量基本成线性关系.对于给定的条件,存在最佳的吸附时间.高径比对产品气浓度的影响与产氧量有关,浓度随高径比增加而增加.     

500kV限流器接入对南网系统过电压的影响分析

串联限流电抗器能有效限制500 kV电压等级的短路电流,但其接入系统后会影响系统的过电压水平,需要进一步进行安全校验。以广南站500 kV/90 kA 限流器示范工程为背景,利用电磁暂态仿真软件EMTP 研究500kV限流电抗器自身的过电压以及限流电抗器接入后对系统的工频过电压、操作过电压、线路断路器的暂态恢复电压,以保证系统与设备的安全运行。结果表明,无论是否采用限流电抗器,顺德-广南500kV线路无故障甩负荷和单相故障切负荷时的工频过电压均在允许的范围内;500 kV限流电抗器接入后的顺德-广南500kV线路合闸操作过电压未超过标准允许范围,变电站及限抗站金属氧化物避雷器MOA能耗及电流与其设计参数相比有很大的裕度。