Dynamic graph learning for spectral feature selection

Previous spectral feature selection methods generate the similarity graph via ignoring the negative effect of noise and redundancy of the original feature space, and ignoring the association between graph matrix learning and feature selection, so that easily producing suboptimal results. To address these issues, this paper joints graph learning and feature selection in a framework to obtain optimal selected performance. More specifically, we use the least square loss function and an ? _2,1-norm regularization to remove the effect of noisy and redundancy features, and use the resulting local correlations among the features to dynamically learn a graph matrix from a low-dimensional space of original data. Experimental results on real data sets show that our method outperforms the state-of-the-art feature selection methods for classification tasks.

     

Local sparsity preserving projection and its application to biometric recognition

Multimedia Tools and Applications - Dimensionality reduction techniques based on sparse representation have drawn great attentions recently and they are successfully applied to biometric...     

The Nucleation Potency of In Situ-Formed Oxides in Liquid Iron

Metallurgical and Materials Transactions A - The nucleation potency of iron oxides was verified experimentally through nucleation undercooling of liquid iron using aerodynamic levitation technology...     

秦山核电基地外围环境水体放射性水平监测

自1992年，浙江省辐射环境监测站对秦山核电基地外围环境放射性水平进行了连续的监督性监测。1992～2004年，基地外围环境水体放射性水平的监测结果表明：秦山核电基地外围地区陆地环境淡水（饮用水、湖塘水、井水）中总α、总β、^90Sr、^137Cs平均浓度分别为67、157、4．4、0．3mBq／L，^3H为1．4Bq／L，雨水中^3H为2．0Bq／L；正常排放下，基地附近海域水样中^90Sr、^137Cs平均浓度分别为1．4、0．7mBq／L，^3H为I．0Bq／L；第一期核电厂三回路冷却水总β、^90Sr、^137Cs平均浓度分别为2．6、4．1、1．0mBq／L，^3H为2．IBq／L，排放口海水^3H平均浓度为1．4Bq／Lo与运行前本底值和对照点监测值相比，秦山核电基地外围环境水体放射性水平在正常波动范围内，基地外围环境陆地淡水和附近海域海水没有受到放射性污染。     

外源RNA促进小鼠肠腺辐射损伤恢复的研究

ＢＡＬＢ／ ｃ小鼠１０４０ｃＧｙ＾６０Ｃｏγ射线腹部照射后，采用不同一源的ＲＮＡ、不同的注入剂量、途径、时间和次数等因素，研究外源ＲＮＡ对空肠肠腺存活率的影响。结果表明（１）不同来源的ＲＮＡ均可明显提高受照小鼠的腺存活率。（２）酵母ＲＮＡ的洲入剂量与肠腺存尖率之间呈一钟形曲线，局部肠腔注入的最适剂量为４０－６０μｇ／小鼠，腹腔和肌肉注入时为８０μｇ／小鼠。     

秦山核电二期工程蒸汽发生器专用吊装工具设计

简要介绍了秦山核电二期工程蒸汽发生器主要专用工程吊装工具的设计。论述了吊装过程、翻转竖立方法、设计原则、设计规范、主要结构材料选用、结构与强度设计、应力分析和试验。这些专用吊装工具已成功地用于秦山核电二期工程１号堆两台蒸汽发生器的吊装。     

仪器中子活化分析自动化系统研究

仪器中子活化分析(INAA)自动化控制系统可减少人员劳动强度和辐射剂量,提高实验室分析容量以及测量准确度。通过对比分析自动化集成系统在INAA实验室的最新进展和最新技术,提出了INAA系统分析过程中各阶段的优化设计方案。INAA自动化集成控制系统可实现样品批量辐照、冷却、测量和分析等一体化控制,为其他实验室设计INAA自动化系统提供一定的参考。     

Designing performance enhanced nuclear battery based on the Cd-109 radioactive source

A dual-effect nuclear battery based on the radio-voltaic and radioluminescence effect was developed, which has the ability to convert nuclear energy into electrical energy with two different modes. Performance-enhanced nuclear batteries are mainly based on the addition of ZnS:Cu radio-luminescent layer to Cd-109 X-ray radioactive source and GaAs radio-voltaic layer. In order to explore the response relationship between the mode of energy conversion and the electrical performance of nuclear battery, the physical model was established to research the deposition energy distribution by using Monte Carlo method. The addition of the radio-luminescent material increases the effective energy deposition of the X-rays and the optimized thickness of ZnS:Cu in such a dual-effect nuclear battery should be set to 560 μm. The current–voltage characteristic curves of the batteries before and after performance optimization were utilized to investigate the electrical properties. Through a comprehensive comparison of Cd-109 nuclear batteries with or without radio-luminescent layer, the simulated results are consistent with experimental results. The results indicate that the electrical performance of dual-effect nuclear battery is significantly higher than that of single radio-voltaic nuclear battery. Moreover, the energy conversion efficiency increases from 0.079% (single radio-voltaic nuclear battery) to 0.119% (dual-effect nuclear battery). The improved performance of the dual-effect nuclear battery provides potential applications for space-based autonomous remote sensors and continuous low-power generation technologies.     

Prediction of curved oil–water interface in horizontal pipes using modified model with dynamic contact angle

In this study, interface shapes of horizontal oil–water two-phase flow are predicted by using Young-Laplace equation model and minimum energy model. Meanwhile, the interface shapes of horizontal oil–water twophase flow in a 20 mm inner diameter pipe are measured by a novel conductance parallel-wire array probe(CPAP). It is found that, for flow conditions with low water holdup, there is a large deviation between the model-predicted interface shape and the experimentally measured one. Since the variation of pipe wetting characteristics in the process of fluid flow can lead to the changes of the contact angle between the fluid and the pipe wall, the models mentioned above are modified by considering dynamic contact angle. The results indicate that the interface shapes predicted by the modified models present a good consistence with the ones measured by CPAP.     

考虑流固耦合的Spar型浮式风力机涡激运动特性研究

对弹性支撑单圆柱在均匀流作用下的涡激运动特性进行数值模拟,捕捉到锁定区、拍、频率变换等现象。柱体周围流场采用Fluent求解,将4阶Runge-Kutta方法代码写入用户自定义函数(UDF)求解运动微分方程,运用动网格技术更新流场,实现圆柱与流场的非线性耦合作用。发现随着折合速度的增大,涡激运动响应可分为锁定前支、锁定区、锁定后支3个阶段,在进入锁定区前(折合速度Ur=3)横向运动响应发生拍现象,当跨过锁定区后(折合速度Ur=10)发生频率变换现象。结果表明,横向涡激运动有较大范围的频率锁定现象,频率解锁前后圆柱涡激运动轨迹由右8字形变换为左8字形。