Preparation and characterization of multilayer Gd2O2S:Tb phosphor screen for X-ray detection application

Gd2O2S:Tb (GOS) phosphor screen, generally with a multilayer structure, has been widely used in digital X-ray imaging. GOS phosphor screen is fabricated via a slip casting route, which is an effective method to obtain multilayer composites with good strength. The GOS slurry was prepared using the menhaden oil, polyvinyl butyral and PEG-400 as dispersant, binder and plasticizer, respectively, and slip casted on a support layer. After the GOS scintillation layer is formed, a transparent polyethylene terephthalate film is covered on it as a protective layer. The X-ray excited emission spectra of the obtained GOS phosphor screen is well match to the spectral response of a-Si:H photodiode, and the spatial resolution was close to 3.7 LP/mm, which could meet the request of the commercial application.     

螺纹量规的数字化检测方法

螺纹量规是判定螺纹紧固件合格与否的重要量具,其几何参数的精确测量具有重要意义。利用螺纹综合测量仪完成了螺纹量规的数字化测量试验,分析得出该方法的测量结果准确,精度可靠。同时对螺纹综合测量仪测量中径的不确定度进行了评定,为螺纹量规的测量质量提供了参考依据。     

数字化核电厂班组SSA测度方法与实验研究

情景意识(SA)问题在数字化核电厂中更为突出。为识别班组共享情景意识（SSA）水平及行为形成因子（PSF）对班组SSA的影响，基于情景意识全面评估技术（SAGAT）建立一种班组SSA测量和计算方法并进行模拟机实验。结果表明，个体SA（ISA）水平与SSA水平有关，ISA级别越高，SSA级别越高；ISA和班组SSA都受到PSF的影响，PSF的状态水平越高，ISA和SSA的水平越高；对于不同的实验场景，操纵员的ISA水平和班组SSA水平不同，这表明风险场景的症状越明显及知识经验水平越好，ISA和SSA水平就越高。最后，通过被试的自评价识别当前PSF的状态水平，主要不良的PSF是班组沟通和合作水平、压力水平、人-机界面等。这些评估结果为提高数字化核电厂人因可靠性和安全水平提供了理论支持。     

Reality-based interaction affecting mental workload in virtual reality mental arithmetic training

ABSTRACT

The concept of digital game-based learning (DGBL) evolves rapidly together with technological enhancements of virtual reality (VR) and smart phones. However, the mental workload (MWL) that VR-training applications demand and motivational qualities originating from user experience (UX) should be identified in order to create effective and enjoyable training/learning challenges that fit with individual users’ capabilities. This study examined the effects of reality-based interaction (RBI) and VR on measures of student motivation and MWL, in a mental arithmetic game for secondary school pupils. In a randomised controlled trial with sixty school children, a mental arithmetic game was tested with three different interaction and two different presentation methods – VR RBI, VR head-mounted-display tapping and tablet flick-gesture. Results found a significant effect of RBI on MWL but no differences in enjoyment of training were found between VR-experience and tablet training-experience. In fact, adding the gaming-context to the mental arithmetic task created an enjoyable, motivating experience regardless of presentation or interaction-style.     

高能同步辐射光源储存环快校正磁铁电源设计

高能同步辐射光源（HEPS）具有0.1 nm·rad的超低发射度，对束流稳定度提出了较高要求，研制1台高性能快校正磁铁电源用来提高快速轨道反馈系统（FOFB）的性能以提升束流稳定度。电源样机采用新颖的多电平级联拓扑结构提升电源样机的动态性能，使用基于数字控制的新颖控制方法实现样机的动态性能提升。软件仿真与样机试验数据证明，电源样机具有10 kHz小信号带宽、电源阶跃响应时间小于70 μs、输出电流纹波低于20 ppm，电源样机可很好地满足HEPS建设需求。     

宽带数字接收机IQ不平衡估计与自适应补偿算法

针对宽带调制解调技术中广泛存在的IQ不平衡问题,在IQ不平衡模型及补偿原理的分析基础上提出了一种宽带数字接收机IQ不平衡估计与自适应补偿算法。首先利用解调数据对IQ不平衡参数进行实时估计,然后利用估计参数对接收信号进行自适应补偿。实验结果表明,所提算法可以有效解决宽带调制解调系统中普遍存在的IQ不平衡问题,提升系统误码性能。     

To shop or not: Understanding Chinese consumers’ live-stream shopping intentions from the perspectives of uses and gratifications,perceived network size,perceptions of digital celebrities,and shopping orientations

Live-stream shopping is experiencing unprecedented growth. However, research in live-stream commerce is in its infancy. The current study integrates uses and gratifications, perceived network size, perceptions of digital celebrities, and experience-focused shopping orientation to clarify motivations for live-stream shopping. Accordingly, the current study used a questionnaire to collect data from 339 Chinese consumers and structural equation modeling to analyze data in AMOS 24. In this study, individuals were motivated by gratifications that were (1) hedonic (perceived enjoyment), (2) utilitarian (self-presentation), and (3) social (social presence and interaction). Moreover, perceived network size significantly predicted perceived enjoyment, social interaction, social presence, and utility. In addition, experience-focused shopping orientation mediated the relationships among perceived enjoyment, self-presentation, social interaction, and live-stream shopping intentions. Finally, the mediating roles of the perceptions of digital celebrities in the relationships of perceived network size with perceived utility, perceived engagement, social interaction, social presence, and self-presentation were confirmed.     

Morphology,adipocyte size,and fatty acid analysis of dairy cattle digital cushions,and the effect of body condition score and age

The digital cushion is an essential part of maintaining a healthy foot, working to dissipate foot strike and body weight forces and lameness from claw horn disruption lesions. Despite the importance of the digital cushion, little is known about the basic anatomy, adipocyte morphology, and fatty acid composition in relation to age, limb position, and body condition score. In total, 60 claws (from 17 cows) were selected and collected from a herd, ensuring that body condition score data and computed micro-tomography were known for each animal. Digital cushion tissue underwent histological staining combined with stereology, systematic random sampling, and cell morphology analysis, in addition to lipid extraction followed by fatty acid analysis. The results describe digital cushion architecture and adipocyte sizes. Adipocyte size was similar across all 4 claws (distal left lateral and medial and distal right lateral and medial) and across the ages (aged 2–7 yr); however, animals with body condition score of 3.00 or more at slaughter had a significantly increased cell size in comparison to those with a score of less than 2.50. Of 37 fatty acid methyl esters identified, 5 differed between either the body condition score or different age groups. C10:0 capric acid, C14:0 myristic acid, C15:0 pentadecanoic acid, and C20:0 arachidic acid percentages were all lesser in lower body condition score cows, whereas C22:1n-9 erucic acid measurements were lesser in younger cows. Saturated fatty acid, monounsaturated fatty acid, and polyunsaturated fatty acid percentages were not altered in the different claws, ages, or body condition score groups. Triglyceride quantities did not differ for claw position or age but had decreased quantities in lower body condition score animals. Digital cushion anatomy, cellular morphology, and fatty acid composition have been described in general and also in animals with differing ages, body condition scores, and in the differing claws. Understanding fat deposition, mobilization, and composition are essential in not only understanding the roles that the digital cushion plays but also in preventing disorders and maintaining cattle health and welfare.     

The effectiveness of adaptive versus non-adaptive learning with digital educational games

For the training of academic skills, digital educational games with integrated adaptivity are promising. Adaptive games are considered superior to non-adaptive games, because they constantly assess children's performance, and accordingly adapt the difficulty of the tasks corresponding to the children's individual level. However, empirical evidence with regard to the effectivity of adaptive compared to non-adaptive games is limited. A study was conducted with 191 children from the third year of Kinder garten who were enrolled in one of three conditions, that is, playing an adaptive version of the reading game (RG), a non-adaptive version of the RG or training with pen-and-paper exercises. In all three conditions, children trained emergent reading (phonological awareness and letter knowledge) once a week for 30 min over a period of 5 weeks. Children's performance on cognitive (phonological awareness, letter knowledge, reading fluency) and non-cognitive (motivation, self-concept) factors was assessed. Results revealed a significant improvement in phonological awareness and letter knowledge in all conditions. However, no differences between the conditions were observed with respect to children's improvement on phonological awareness and letter knowledge or on their post-test scores for reading fluency. With regard to motivation and self-concept, again, no differences in these non-cognitive factors were observed across conditions.     

Inverse identification of constitutive parameters from heat source fields: A local approach applied to hyperelasticity

In this paper, a new inverse identification method of constitutive parameters is developed from full kinematic and thermal field measurements. It consists in reconstructing the heat source field from two different approaches by using the heat diffusion equation. The first one requires the temperature field measurement and the value of the thermophysical parameters. The second one is based on the kinematic field measurement and the choice of a thermo-hyperelastic model that contains the parameters to be identified. The identification is carried out at the local scale, ie, at any point of the heat source field, without using the boundary conditions. In the present work, the method is applied to the challenging case of hyperelasticity from a heterogeneous test. Due to large deformations undergone by the rubber specimen tested, a motion compensation technique is developed to plot the kinematic and the thermal fields at the same points before reconstructing the heterogeneous heat source field. In the present case, the constitutive parameter of the Neo-Hookean model has been identified, and its distribution has been characterized with respect to the strain state at the surface of a cross-shaped specimen.