混凝土面板堆石坝填筑料选择的几个问题

混凝土面板堆石坝填筑材料的选择,应视坝体各区对其的要求不一而有所区别,坝体变形和坝体渗透稳定同样也对填筑材料提出了不同的质量要求。对填筑材料场的选择应讲究一定的原则。     

Mechanical Behaviors of Silt Rock Subjected to Coupling Static and Impact Loads

Experiments of silt rock subjected to coupling loads were carried out on tailormade equipment. With a constant dynamic load, the behaviors of eight sets of siltite specimens were investigated with different axial static loads. The experimental results show that the modulus of the specimens under coupling loads increases at first and then decreases with the increase of axial static pressure. The failure model of the specimens also varies. Keeping the dynamic load constant, when the axial static pressure is low, the specimen breaks in two simply. With the increase of axial static pressure, the cone-shaped fragment appeares. When the axial static pressure reaches 90% of the static strength of rock, the specimen smashes into amount of small fragments.     

关于函数可积性与原函数存在性问题

本文结合实例探讨了函数的可积性与原函数的存在性之间的相互关系。     

混合岩化作用和混合岩成因模式研究

具备油气水组合的圈闭构造，在地下深处能形成重熔岩浆，富含气体的岩浆能导致圈闭隐爆而上侵入，研究认为，混合岩化作用及混合岩就是在这种圈闭隐爆过程中产生形成的。     

攀岩者深度休闲特征的研究

基于深度休闲理论,采用质性方法探索攀岩者的深度休闲特征,从而揭示攀岩的意义和价值。对11名参与1年以上的攀岩者进行开放式访谈,运用质性分析软件NVivo 11.0对数据进行主题分析。研究发现,攀岩者具有4项深度休闲特征,即自我超越、认同感、个人利益和独特个性。深度攀岩者渴望不断超越自我,突破个人能力局限。他们认同攀岩项目和攀岩社会,将攀岩内化为自我的一部分。他们获得了生理和心理上的个人利益,尤其可以满足在工作中未能满足的成就需求。他们的独特个性包括独立、坚韧和沉静,可以被攀岩塑造。建议未来加大普及攀岩的力度,鼓励更多人参与攀岩,培养深度休闲生活方式。     

Regression Discontinuity Designs With Multiple Rating-Score Variables

Abstract

In the absence of a randomized control trial, regression discontinuity (RD) designs can produce plausible estimates of the treatment effect on an outcome for individuals near a cutoff score. In the standard RD design, individuals with rating scores higher than some exogenously determined cutoff score are assigned to one treatment condition; those with rating scores below the cutoff score are assigned to an alternate treatment condition. Many education policies, however, assign treatment status on the basis of more than one rating-score dimension. We refer to this class of RD designs as “multiple rating score regression discontinuity” (MRSRD) designs. In this paper, we discuss five different approaches to estimating treatment effects using MRSRD designs (response surface RD; frontier RD; fuzzy frontier RD; distance-based RD; and binding-score RD). We discuss differences among them in terms of their estimands, applications, statistical power, and potential extensions for studying heterogeneity of treatment effects.     

高职公共体育教学改革实践研究——以南宁职业技术学院户外攀岩俱乐部教学为例

随着新体育课程标准的实施,体育课堂教学必须改革创新。在现今的社会环境下,什么样的体育教学既能促进大学生身心健康的发展,又能锻炼学生的人际交往、组织管理、培养自信心等能力,更能体现出职业学院的职业体育特色?南宁职业技术学院公共体育教学改革——户外攀岩休闲俱乐部教学对开设目的与功能和意义进行了探讨,依据各地高校体育教学和户外运动开展的实际情况,精心地设计户外休闲运动课程体系,以此为高校户外教学提供理论和实证依据。     

隧道软弱围岩斜井进正洞挑顶施工技术的研究

隧道施工中经常遇到斜井进正洞的情况,从工艺原理、施工方法、监控量测等方面对斜井进正洞挑顶施工技术进行详细阐述,并提出质量控制以及施工安全的措施,对同类施工具有参考和借鉴意义。     

Examining relationships among elementary schools' contexts,leadership, instructional practices,and added-year outcomes: a regression discontinuity approach

This study proposes and tests a multilevel structural model of school context, composition, and school leadership on school instructional practices and outcomes in elementary schools in a western state in the United States. We focus on direct and indirect relationships implied in our proposed model using an “added year of schooling” in reading and math as our primary school-level outcomes. Added-year effects, which result from a regression discontinuity design, represent a relatively new approach for describing how school factors influence outcomes. Our results suggest that, net of context and composition factors, improvement-focused school leadership directly affected subsequent school instructional practices and, in turn, instructional practices affected added-year outcomes. We discuss the findings in terms of their theoretical and practical implications for conducting further educational effectiveness research.     

Phosphorus status and microbial community of paddy soil with the growth of annual ryegrass (Lolium multiflorum Lam.) under different phosphorus fertilizer treatments

Annual ryegrass (Lolium multiflorum Lam.) was grown in paddy soil in pots under different phosphorus (P) fertilizer treatments to investigate changes of P fractions and microbial community of the soil. The treatments included Kunyang phosphate rock (KPR) applications at 50 mg P/kg (KPR50) and 250 mg P/kg (KPR250), mono-calcium phosphate (MCP) application at 50 mg P/kg (MCP50), and the control without P application. The results showed that KPR50, KPR250, and MCP50 applications significantly increased the dry weight of the ryegrass by 13%, 38%, and 55%, and increased P uptake by 19%, 135%, and 324%, respectively. Compared with MCP50, the relative effectiveness of KPR50 and KPR250 treatments in ryegrass production was about 23% and 68%, respectively. After one season ofryegrass growth, the KPR50, KPR250, and MCP50 applications increased soil-available P by 13.4%, 26.8%, and 55.2%, respectively. More than 80% of the applied KPR-P remained as HCI-P fraction in the soil. Phospholipid fatty acid (PLFA) analysis showed that the total and bacterial PLFAs were significantly higher in the soils with KPR250 and MCP50 treatments compared with KPR50 and control. The latter had no significant difference in the total or bacterial PLFAs. The KPR50, KPR250, and MCP50 treatments increased fungal PLFA by 69%, 103%, and 69%, respectively. Both the principal component analysis and the cluster analysis of the PLFA data suggest that P treatments altered the microbial community composition of the soils, and that P availability might be an important contributor to the changes in the microbial community structure during the ryegrass growth in the paddy soils.