细长轴车削动特性的研究   总被引：9，自引：0，他引：9  

黄跃华  张景勘  李德滋 《科技通报》2001,17(4):41-45,49

对细长轴车削的动特性进行了分析、试验和研究，为保证细长轴车削的稳定性以提高加工质量，提出了转速与进量的合理计算公式，计算与实验结果基本一致。  相似文献   

面向城市应急管理的情报能力建设思考     

李阳 《现代情报》2019,39(5):17-23

[目的/意义]研究面向城市应急管理的情报能力建设问题，既是大数据时代城市应急管理变革的基本要求，也是实现城市智慧应急的重要途径，能够推动应急管理情报支持的理论创新与实践应用。[方法/过程]立足情报能力与城市应急管理之间的逻辑关系，阐释城市应急管理情报能力的内涵，从多维视域探讨城市应急管理情报能力建设的主要内容，分析新时代城市应急管理情报能力建设的发展机遇。[结果/结论]情报能力建设是城市应急管理的关键支撑。城市应急管理情报能力建设涉及情报资源、情报人员、情报管理、情报技术、情报实战等多方面的内容。目前，应抓住新型智慧城市建设与情报治理创新两个方向的发展机遇，支持城市应急管理情报能力的综合提升。  相似文献   

长白山地区蒙古栎光合特性   总被引：15，自引：0，他引：15  

吴家兵  关德新  张弥  施婷婷  韩士杰  金昌杰 《中国科学院研究生院学报》2006,23(4):548-554

基于单叶尺度上的光强－光合响应以及CO2－光合响应测定，对长白山地区蒙古栎成树和幼树的光合特性分别进行了研究．结果表明，蒙古栎成树的光补偿点（Lcp）为21μmol/m2/s，光饱和点（Lsp）为1564μmol/m2/s，表观量子效率（a）为0.045μmol/mol；幼树的Lcp、Lsp、a以及CO2补偿点、饱和点分别为29μmol/m2/s、1581μmol/m2/s、0.049μmol/mol、73μmol/mol、625μmol/mol．幼树和成树具有相似的光响应特征，但前者的光合同化能力要高于后者．蒙古栎具有典型的喜光性，但对高光的利用效率要低于弱光．  相似文献   

Identifying families with complex needs after an initial child abuse investigation: A comparison of demographics and needs related to domestic violence,mental health,and substance use     

《Child abuse & neglect》2017

Families with complex needs related to domestic violence, mental health, and substance use have some of the worst child protective services (CPS) outcomes. Although many of these families are identified during a CPS investigation and subsequently referred to home-based postinvestigation services (HBPS), many are re-reported to CPS, so it is important to understand the postinvestigation experiences of this vulnerable group. Therefore, this study compared families with and without complex needs to understand their uniquedemographics, needs, and postinvestigation outcomes.The sample consisted of 2008 caregivers who received HBPS following an initial CPS investigation. The Family Assessment Form (FAF) was used to measure family functioning in eight domains using a 1–5 scale with higher ratings representing worse functioning. Complex needs were indicated by a mean FAF score of 3 or higher for either domestic violence, mental health, or substance use. Using Pearson chi-square analyses and two-sample t-tests, comparisons were made between families with (n = 836) and without (n = 1172) complex needs. Half of caregivers with complex needs had a history of abuse, 25% had three to five needs, and nearly half had six to eight needs; 90% of caregivers without complex needs had zero to two needs. Furthermore, caregivers with complex needs had higher mean scores for concrete, educational, and clinical needs. These findings highlight the importance of recognizing variation among families referred to HBPS and accurate screening to ensure that families with complex needs are offered and receive services matched to their unique characteristics and needs.  相似文献   

Assessing the Sensitivity of Weighted Least Squares Model Fit Indexes to Local Dependence in Item Response Theory Models     

Anne Corinne Huggins-Manley  HyunSuk Han 《Structural equation modeling》2017,24(3):331-340

Given the relationships of item response theory (IRT) models to confirmatory factor analysis (CFA) models, IRT model misspecifications might be detectable through model fit indexes commonly used in categorical CFA. The purpose of this study is to investigate the sensitivity of weighted least squares with adjusted means and variance (WLSMV)-based root mean square error of approximation, comparative fit index, and Tucker–Lewis Index model fit indexes to IRT models that are misspecified due to local dependence (LD). It was found that WLSMV-based fit indexes have some functional relationships to parameter estimate bias in 2-parameter logistic models caused by violations of LD. Continued exploration into these functional relationships and development of LD-detection methods based on such relationships could hold much promise for providing IRT practitioners with global information on violations of local independence.  相似文献   

真涡虫的习性   总被引：1，自引：0，他引：1  

丁建发 《宁德师专学报(自然科学版)》2004,16(1):24-26

简要叙述了真涡虫的形态、生态、运动、食性、光反应性、再生、生殖等方面的习性．  相似文献   

基于VAR模型的中国消费价格指数分析   总被引：5，自引：0，他引：5  

李庆华 《华中师范大学学报(人文社会科学版)》2006,45(4):56-61

本文在建立中国消费价格指数、货币供给增长和固定资产投资增长的VAR模型的基础上,通过对脉冲响应函数及其方差分解的研究,一方面得出了消费价格指数对本身的冲击和对滞后的固定资产投资的冲击是敏感的,而对货币供给量的增长率的变化是不敏感的结论;另一方面得到了一个从粮食种植面积减少到消费价格指数上升的传递机制和货币供给量的增长率的一个不能被公众预测的突发性变化到消费价格指数同方向变化的传导机制。最后提出了相应的政策建议:在政策层面上仍应以稳健为主。加强对土地开发利用的管理,抑制耕地面积下降的势头,通过灵活运用隐蔽性较强的货币政策调节货币供给量。加强对政府投资特别是地方政府投资的管理,减少固定资产投资中的非理性因素。  相似文献   

从新课标看自主学习     

任清敏 《安顺学院学报》2005,(1)

学习必须主动、独立、创新,培养实际能力。自主学习是指具有自觉的意识和反应的学习方式。自主阅读是自主学习的关键。总结能力是自主学习非常重要的一个方面。自主学习是指教学条件下的学生的高品质的学习。  相似文献   

当前大学生挫折心理成因及其教育对策   总被引：3，自引：0，他引：3  

吴雪梅 《重庆职业技术学院学报》2005,14(3):142-143,148

当前大学生心理健康越来越受到关注，对于大学生挫折的研究，可以使我们充分了解在校大学生的心理状态．为学校的思想工作提供理论依据，为培养学生的良好心理素质提供有效的途径。  相似文献   

汉英双语者心理词汇的发展研究     

李黎  倪传斌 《外语教学理论与实践》2021,173(1):16

本研究应用反应时测量,探究汉英双语者心理词汇的结构和发展。被试为两组大学生,执行汉英翻译判断任务。576组实验材料由拉丁方分配为四个词表,均包含翻译词对、词形干扰词对、语义干扰词对和无关词对。组间比较发现,只有语义干扰效应量有显著差异。组内比较显示,只有高水平组语义干扰大于词形干扰。结果提示,汉英双语者心理词汇结构最显著的特点是词形和语义连结长期混合存在;权重呈非同步、非均衡、量变的发展特征。  相似文献