物理显影记录系统

简述了物理显影记录系统的原理和特性 ,并讨论了PD -D系统和PD -R系统 ,彩色物理显影以及物理显影的应用等 ,以期对物理显影有着更深入的理解     

Plan and generate: Explicit and implicit variational augmentation for multi-document summarization of scientific articles

Multi-Document Summarization of Scientific articles (MDSS) is a challenging task that aims to generate concise and informative summaries for multiple scientific articles on a particular topic. However, despite recent advances in abstractive models for MDSS, grammatical correctness and contextual coherence remain challenging issues. In this paper, we introduce EDITSum, a novel abstractive MDSS model that leverages sentence-level planning to guide summary generation. Our model incorporates neural topic model information as explicit guidance and sequential latent variables information as implicit guidance under a variational framework. We propose a hierarchical decoding strategy that generates the sentence-level planning by a sentence decoder and then generates the final summary conditioned on the planning by a word decoder. Experimental results show that our model outperforms previous state-of-the-art models by a significant margin on ROUGE-1 and ROUGE-L metrics. Ablation studies demonstrate the effectiveness of the individual modules proposed in our model, and human evaluations provide strong evidence that our model generates more coherent and error-free summaries. Our work highlights the importance of high-level planning in addressing intra-sentence errors and inter-sentence incoherence issues in MDSS.     

坪宝地区深部找矿潜力分析

坪宝地区有黄沙坪、宝山两个大型Pb、Zn（Cu）矿床,由于矿山长期开采,前几年矿山的铅锌资源已处于危机状态。但通过近两年的危机矿山接替资源找矿工作,已经取得突破性进展,在开采铅锌矿的开拓系统深部,又发现或找到了厚度较大、质量较好的铅锌（铜）矿体及大规模的矽卡岩型（铁）钨钼多金属矿体。文章在分析前人资料的同时,通过分析研究区内成矿地质背景、铅锌矿控矿地质条件、地球物理和地球化学背景及成矿模式,对坪宝地区深部铜铅锌及钨钼资源的找矿潜力进行了初步分析,初步确定了区内深部找矿靶区及找矿潜力．     

污水源采集凝固热热泵系统的可行性分析

针对常规污水源热泵系统出力常无法满足建筑最大负荷的问题,提出了在高峰负荷下提取污水凝固潜热作为补充热源的新思路.首先,结合污水特征设计了一种集除冰、取热、除垢于一体的凝固换热器,并给出了城市污水源采集凝固热热泵的合理形式.然后,从理论上分析探讨了新系统的供热潜力.典型的工况计算结果表明,采集凝固热热泵系统的供热能力大于常规城市污水源热泵系统,两者的最大供热率之比在4.5～8.7之间,说明该污水源采集凝固热热泵系统在寒冷地区的应用潜力较大.     

工作记忆:人类高级认知活动的核心

工作记忆是个体在执行认知任务过程中,对信息暂时保持与操作的能力。近年来的诸多研究指出,工作记忆在人类智力、学习、推理、创造力等高级认知活动中起重要的作用。潜变量分析揭示了工作记忆的中央执行系统与高级认知活动之间存在着密切关系;而脑成像研究显示,工作记忆与高级认知活动的共享脑机制可能是两者关系紧密的主要原因;通过对个体工作记忆能力的训练,提升其阅读能力、智力水平等高级认知能力的干预研究,则进一步证明了工作记忆在人类高级认知活动中的核心影响。     

基于LSI理论的文本自动聚类研究

结合潜性语义索引（latent semantic index,LSI）理论和K-means聚类法,提出一种改进的文本自动聚类方法,即首先利用N-gram统计法抽取文档关键词,并应用潜性语义索引LSI对构建文档的向量空间模型进行降维,然后采用K-means算法进行文本聚类。实验表明,该算法进行文本聚类的准确度最高可达84.7%。     

Assessing Measurement Invariance in Multiple-Group Latent Profile Analysis

The study of measurement invariance in latent profile analysis (LPA) indicates whether the latent profiles differ across known subgroups (e.g., gender). The purpose of the present study was to examine the impact of noninvariance on the relative bias of LPA parameter estimates and on the ability of the likelihood ratio test (LRT) and information criteria statistics to reject the hypothesis of invariance. A Monte Carlo simulation study was conducted in which noninvariance was defined as known group differences in the indicator means in each profile. Results indicated that parameter estimates were biased in conditions with medium and large noninvariance. The LRT and AIC detected noninvariance in most conditions with small sample sizes, while the BIC and adjusted BIC needed larger sample sizes to detect noninvariance. Implications of the results are discussed along with recommendations for future research.     

改进潜在语义索引的个性化搜索引擎的设计

个性化搜索引擎是一种通过机器主动学习用户兴趣,并根据用户兴趣帮助用户进行信息筛选的新一代智能化搜索引擎,潜在语义索引模型在词与词、文本与文本之间的检索中具有先进性．针对该模型中文档集用户兴趣有效性低的问题引入用户个性词典来改进,给出一个完整的可学习用户兴趣并可动态调整的个性化搜索引擎的设计．实验表明潜在语义索引比向量空间模型具有更好的信息检索性能,同时改进的潜在语义索引算法与传统算法相比在文献检索方面性能有明显提高．     

Relationships between cardiorespiratory fitness,inhibition, and math fluency: A cluster analysis

ABSTRACT

This study identified clusters of adolescents who share similar cardiorespiratory fitness levels and analysed the relationships between cardiorespiratory fitness, inhibition, and math fluency in each of the clusters. The subjects were 490 high-school students aged 10–16 years. The mean age was 13.82 years (SD = 1.12). Latent class analysis identified three clusters with high, medium, and low levels of cardiorespiratory fitness. The high-fitness cluster achieved higher scores in inhibition and math fluency than the low-fitness cluster. Path analysis revealed that the influence of cardiorespiratory fitness on inhibition was non-existent in the three clusters. The effect of inhibition on math fluency was positive and significant in all three cardiorespiratory fitness levels. Cardiorespiratory fitness had a direct, positive, and significant effect on math fluency only in the high-fitness cluster. Therefore, a high level of cardiorespiratory fitness is a significant determining factor in the explanation of math fluency. These results indicate that inhibition does not mediate the relationship between cardiorespiratory fitness and math fluency. However, the benefits of cardiorespiratory fitness affect math fluency, which has important implications for the educational environment and the teaching/learning process.     

A Latent Growth Curve Approach to Investigating Developmental Dynamics and Correlates of Change in Children's Perceptions of Physical Competence

Abstract

In both the physical and academic domains interest has recently grown regarding developmental change in children's perceptions of competence. Recent advances in statistical methodology, such as latent growth modeling, enable the researcher to analyze developmental trends from both an inter- and intraindividual perspective, thus serving to increase our understanding of correlates of change in perceived competence. Using latent growth modeling, the purpose of the present study was to investigate developmental change in children's perceived competence at physical skills, examining maturational factors and chronological age as possible correlates of change. Subjects were male adolescents (N = 94). Data were collected during the child's sixth, eighth, and ninth grade school years. Results revealed a good fit for the hypothesized model, which specified mean level changes in the variables over time and an interrelationship among the latent chronometric common factors. Although a significant relationship existed between maturation and perceived competence, no significant relationship was evident between chronological age and perceived competence. Findings are discussed with particular reference to the utility of latent growth curve models for assessing developmental processes at both the inter- and intraindividual level.