As an important optical constant of optical properties for spectacle lens,the refractive index measurement is studied using V prism refractometer. In the experiment,according to various factors inducing measurement er...As an important optical constant of optical properties for spectacle lens,the refractive index measurement is studied using V prism refractometer. In the experiment,according to various factors inducing measurement error,the experimental results are analyzed,which include right angle deviation,contact liquid,curvature,and focusing accuracy. The study results show that focusing accuracy is the most important factor of influence for measurement,consists of contact liquid wettability,sample shape,and effective width of light transmission. In addition,the refractive index measurement is less affected by angle deviation of sample and the refractive index deviation of contact liquid. On the basis of the experimental data analysis,it is possible to relax the deviation of right angle of the sample to 1' or 2'.展开更多
目的以桂枝茯苓胶囊(Guizhi Fuling Capsules,GFC)和天舒胶囊(Tianshu Capsule,TC)为研究对象,将近红外光谱(near-infrared spectroscopy,NIRS)技术与机器学习算法结合,建立快速检测2种制剂中间体水分的方法。方法采集GFC总混颗粒和TC...目的以桂枝茯苓胶囊(Guizhi Fuling Capsules,GFC)和天舒胶囊(Tianshu Capsule,TC)为研究对象,将近红外光谱(near-infrared spectroscopy,NIRS)技术与机器学习算法结合,建立快速检测2种制剂中间体水分的方法。方法采集GFC总混颗粒和TC总混颗粒的NIRS,考察不同的预处理方法、变量筛选方法及算法对模型的影响,筛选最佳建模条件,并对2种中间体建立1个水分NIRS通用定量模型。结果对同一中间体建立定量模型时,广义路径追踪(generalized path seeker,GPS)算法均优于偏最小二乘(partial least square,PLS)算法;GPS通用模型与PLS通用模型相比,预测性能更高,验证集相对偏差(relative standard errors of prediction,RSEP)由3.17%降至3.03%,性能偏差比(ratio of performance to deviation,RPD)由4.83升至5.05,可用于水分的预测,且与独立模型的预测性能相差不大。结论GPS算法结合NIRS技术建立的通用定量模型,可快速、准确地检测2种制剂中间体的水分。展开更多
By model test and numerical simulation, this paper analyzed the effects of different blades with varying rotation angle deviations on the hydraulic performance of a mixed-flow pump. It was found that when some blades ...By model test and numerical simulation, this paper analyzed the effects of different blades with varying rotation angle deviations on the hydraulic performance of a mixed-flow pump. It was found that when some blades had rotation angle deviations, the hydraulic performance curves of the mixed-flow pump would move. With a positive deviation, the curves moved towards the large flow rate; with a negative deviation, the curves moved towards the small flow rate. When some blades had rotation angle deviations, the symmetry and uniformity of the pressure distribution inside the mixed-flow pump flow passage both decreased; the larger the deviation, the greater the decrease. When a single blade had a large rotation angle deviation, a rather clear low pressure area was formed, lowering the cavitation performance. When two adjacent blades changed simultaneously, under the small flow rate condition, adverse pressure gradient and flow separation occurred in the flow field, and a hump appeared in the head curve and the operation stability of the mixed-flow pump dropped significantly. Near the best efficiency point（BEP）, the simultaneous change of two alternate blades produced a more significant change of pressure in the flow passage, with an even larger area. Compared to the effect of two adjacent blades, two alternate blades, when changed simultaneously, made the mixed-flow pump slightly less efficient, but with a flatter efficiency curve and relatively wider high efficiency area. By fitting the test results, a functional relation among the BEP of the mixed-flow pump QBEP, the number of deviated blades N, and blade rotation angle deviation α was established, thus realizing an effective prediction of the BEP of the mixed-flow pump when blade rotation angles have deviations.展开更多
Purpose： Alcohol consumption can lead to risky driving and increase the frequency of traffic accidents, injuries and mortalities. The main purpose of our study was to compare simulated driving performance between two...Purpose： Alcohol consumption can lead to risky driving and increase the frequency of traffic accidents, injuries and mortalities. The main purpose of our study was to compare simulated driving performance between two groups of drivers, one consumed alcohol and the other not consumed, using a systematic review. Methods： In this systematic review, electronic resources and databases including Medline via Ovid SP, EMBASE via Ovid SP, PsyclNFO via Ovid 5P, PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature （CINHAL） via EBSCOhost were comprehensively and systematically searched. The randomized controlled clinical trials that compared simulated driving performance between two groups of drivers, one consumed alcohol and the other not consumed, were included. Lane position standard deviation （LPSD）, mean of lane position deviation （MLPD）, speed, mean of speed deviation （MSD）, standard deviation of speed deviation （SDSD）, number of accidents （NA） and line crossing （LC） were considered as the main parameters evaluating outcomes. After title and abstract screening, the articles were enrolled for data extraction and they were evaluated for risk of biases. Results： Thirteen papers were included in our qualitative synthesis. All included papers were classified as high risk of biases. Alcohol consumption mostly deteriorated the following performance outcomes in descending order： SDSD, LPSD, speed, MLPD, LC and NA. Our systematic review had troublesome heterogeneity. Conclusion： Alcohol consumption may decrease simulated driving performance in alcohol consumed people compared with non-alcohol consumed people via changes in SDSD, LPSD, speed, MLPD, LC and NA. More well-designed randomized controlled clinical trials are recommended.展开更多
文摘As an important optical constant of optical properties for spectacle lens,the refractive index measurement is studied using V prism refractometer. In the experiment,according to various factors inducing measurement error,the experimental results are analyzed,which include right angle deviation,contact liquid,curvature,and focusing accuracy. The study results show that focusing accuracy is the most important factor of influence for measurement,consists of contact liquid wettability,sample shape,and effective width of light transmission. In addition,the refractive index measurement is less affected by angle deviation of sample and the refractive index deviation of contact liquid. On the basis of the experimental data analysis,it is possible to relax the deviation of right angle of the sample to 1' or 2'.
文摘目的以桂枝茯苓胶囊(Guizhi Fuling Capsules,GFC)和天舒胶囊(Tianshu Capsule,TC)为研究对象,将近红外光谱(near-infrared spectroscopy,NIRS)技术与机器学习算法结合,建立快速检测2种制剂中间体水分的方法。方法采集GFC总混颗粒和TC总混颗粒的NIRS,考察不同的预处理方法、变量筛选方法及算法对模型的影响,筛选最佳建模条件,并对2种中间体建立1个水分NIRS通用定量模型。结果对同一中间体建立定量模型时,广义路径追踪(generalized path seeker,GPS)算法均优于偏最小二乘(partial least square,PLS)算法;GPS通用模型与PLS通用模型相比,预测性能更高,验证集相对偏差(relative standard errors of prediction,RSEP)由3.17%降至3.03%,性能偏差比(ratio of performance to deviation,RPD)由4.83升至5.05,可用于水分的预测,且与独立模型的预测性能相差不大。结论GPS算法结合NIRS技术建立的通用定量模型,可快速、准确地检测2种制剂中间体的水分。
基金supported by the National Natural Science Foundation of China(Grant No.51176088)
文摘By model test and numerical simulation, this paper analyzed the effects of different blades with varying rotation angle deviations on the hydraulic performance of a mixed-flow pump. It was found that when some blades had rotation angle deviations, the hydraulic performance curves of the mixed-flow pump would move. With a positive deviation, the curves moved towards the large flow rate; with a negative deviation, the curves moved towards the small flow rate. When some blades had rotation angle deviations, the symmetry and uniformity of the pressure distribution inside the mixed-flow pump flow passage both decreased; the larger the deviation, the greater the decrease. When a single blade had a large rotation angle deviation, a rather clear low pressure area was formed, lowering the cavitation performance. When two adjacent blades changed simultaneously, under the small flow rate condition, adverse pressure gradient and flow separation occurred in the flow field, and a hump appeared in the head curve and the operation stability of the mixed-flow pump dropped significantly. Near the best efficiency point（BEP）, the simultaneous change of two alternate blades produced a more significant change of pressure in the flow passage, with an even larger area. Compared to the effect of two adjacent blades, two alternate blades, when changed simultaneously, made the mixed-flow pump slightly less efficient, but with a flatter efficiency curve and relatively wider high efficiency area. By fitting the test results, a functional relation among the BEP of the mixed-flow pump QBEP, the number of deviated blades N, and blade rotation angle deviation α was established, thus realizing an effective prediction of the BEP of the mixed-flow pump when blade rotation angles have deviations.
文摘Purpose： Alcohol consumption can lead to risky driving and increase the frequency of traffic accidents, injuries and mortalities. The main purpose of our study was to compare simulated driving performance between two groups of drivers, one consumed alcohol and the other not consumed, using a systematic review. Methods： In this systematic review, electronic resources and databases including Medline via Ovid SP, EMBASE via Ovid SP, PsyclNFO via Ovid 5P, PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature （CINHAL） via EBSCOhost were comprehensively and systematically searched. The randomized controlled clinical trials that compared simulated driving performance between two groups of drivers, one consumed alcohol and the other not consumed, were included. Lane position standard deviation （LPSD）, mean of lane position deviation （MLPD）, speed, mean of speed deviation （MSD）, standard deviation of speed deviation （SDSD）, number of accidents （NA） and line crossing （LC） were considered as the main parameters evaluating outcomes. After title and abstract screening, the articles were enrolled for data extraction and they were evaluated for risk of biases. Results： Thirteen papers were included in our qualitative synthesis. All included papers were classified as high risk of biases. Alcohol consumption mostly deteriorated the following performance outcomes in descending order： SDSD, LPSD, speed, MLPD, LC and NA. Our systematic review had troublesome heterogeneity. Conclusion： Alcohol consumption may decrease simulated driving performance in alcohol consumed people compared with non-alcohol consumed people via changes in SDSD, LPSD, speed, MLPD, LC and NA. More well-designed randomized controlled clinical trials are recommended.
