浅谈Oracle数据库性能调优

对数据库进行优化是DBA的一个工作重点,本文以Oracle为例,简单论述了数据库本身的一些性能优化方法,重点包括了数据库系统的内存调优和Oracle的数据封锁机制等。     

Establishment of gender- and age-specific reference intervals for serum liver function tests among the elderly population in northeast China: a retrospective study

IntroductionReference intervals (RIs) for younger population may not apply to the elderly population. The aim of this study was to establish gender- and age-specific RIs for serum liver function tests among the elderly population and to compare with younger population RIs currently used in China and other countries.Materials and methodsThis was a retrospective study, and subjects (≥ 18 year-old) were recruited from the laboratory information system (LIS) at the First Hospital of Jilin University between April 2020 and April 2021. The following parameters were collected: aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), alkaline phosphatase (ALP), total protein (TP), albumin (ALB), total bilirubin (TBIL), and direct bilirubin (DBIL). The Tukey method was used to eliminate outliers. Reference intervals were established by the nonparametric method.ResultsA total of 23,597 healthy individuals were enrolled in the study. From all parameters AST, ALT, TP and ALB required no gender partition, while ALT, GGT, TP, ALB and DBIL required different partitions for age. Activities and concentrations of ALT, ALB, and TP showed a downward trend in the elderly aged 60-89. In contrast, DBIL showed a gradual upward trend.ConclusionThe RIs for liver function tests among healthy elderly population were different from those among young population in China. There were apparent gender and age differences in the RIs of liver function for elderly and significant differences compared with national standards and RIs in other countries. Therefore, it is necessary to establish gender- and age-specific RIs for serum liver function tests among the elderly population.     

虚拟社区研究现状及展望

在阐述虚拟社区定义和分类的基础上,采用内容分析法,从文献的研究内容及研究方法两个维度切入．对国内外虚拟社区研究现状做了简要的统计及分析。认为我国对虚拟社区的应用、绩效评估以及产业化应用等内容的研究相对缺乏,研究方法上并不注重定量分析方法的应用。目前我国在虚拟社区研究及实际应用中亟待解决虚拟社区成员行为方面的定量研究、虚拟社区在知识共享上的运作机制及绩效评价这两方面的问题。     

颜真卿的生死大义

颜真卿走上仕途之后,基本上处于李唐王朝的乱世,先是安史之乱,后是藩镇割据.朝廷之上,又先后有杨国忠、李辅国、元载、卢杞等奸倭之徒得势弄权.然而,对于乱局,他敢于担当;对于奸佞,他疾恶如仇;身陷绝境,他临危不惧.可谓乱世凸显忠孝,生死俱存大义.     

The mediating effects of needs satisfaction on the relationships between prior knowledge and self-regulated learning through artificial intelligence chatbot

The anthropomorphic characteristics of artificial intelligence (AI) can provide a positive environment for self-regulated learning (SRL). The factors affecting adolescents' SRL through AI technologies remain unclear. Limited AI and disciplinary knowledge may affect the students' motivations, as explained by self-determination theory (SDT). In this study, we examine the mediating effects of needs satisfaction in SDT on the relationship between students' previous technical (AI) and disciplinary (English) knowledge and SRL, using an AI conversational chatbot. Data were collected from 323 9th Grade students through a questionnaire and a test. The students completed an AI basic unit and then learned English with a conversational chatbot for 5 days. Confidence intervals were calculated to investigate the mediating effects. We found that students' previous knowledge of English but not their AI knowledge directly affected their SRL with the chatbot, and that satisfying the need for autonomy and competence mediated the relationships between both knowledge (AI and English) and SRL, but relatedness did not. The self-directed nature of SRL requires heavy cognitive learning and satisfying the need for autonomy and competence may more effectively engage young children in this type of learning. The findings also revealed that current chatbot technologies may not benefit students with relatively lower levels of English proficiency. We suggest that teachers can use conversational chatbots for knowledge consolidation purposes, but not in SRL explorations.

Practitioner notes

What is already known about this topic

• Artificial intelligence (AI) technologies can potentially support students' self-regulated learning (SRL) of disciplinary knowledge through chatbots.
• Needs satisfaction in Self-determination theory (SDT) can explain the directive process required for SRL.
• Technical and disciplinary knowledge would affect SRL with technologies.

What this paper adds

• This study examines the mediating effects of needs satisfaction in SDT on the relationship between students' previous AI (technical) and English (disciplinary) knowledge and SRL, using an AI conversational chatbot.
• Students' previous knowledge of English but not their AI knowledge directly affected their SRL with the chatbot.
• Autonomy and competence were mediators, but relatedness was not.

Implications for practice and/or policy

• Teachers should use chatbots for knowledge consolidation rather than exploration.
• Teachers should support students' competence and autonomy, as these were found to be the factors that directly predicted SRL.
• School leaders and teacher educators should include the mediating effects of needs satisfaction in professional development programmes for digital education.

     

劳动参与对高职学生健康水平影响的调查与研究

高校后勤社会化背景下,寝室是大学生从事劳动活动最频繁的场所。以山西省3所职业院校学生为研究对象,基于问卷调查探究了寝室劳动参与对健康水平的影响。分析结果显示,学生劳动参与能够显著提升其自评健康、客观健康和心理健康水平。基于研究发现,建议从加强寝室文化建设、注重寝室劳动实践、严格寝室卫生管理等三方面着手,激发劳动意识、培养劳动习惯、提升劳动品质,在劳动参与中提高学生的健康水平。