Fluid balance and hydration assessment during the weight-stable preparation phase in elite youth boxers

This study investigated (i) the prevalence of hypohydration and (ii) association between urinary indices of hydration status and confounding factors (e.g., urine protein content, water intake) in elite youth boxers during their weight-stable phase before competition. Sixteen national champion boxers (all male, 17 ± 1 y) were measured on 3 occasions (baseline, day 3, day 10), 30-day prior to competition. Body mass, total body water, urine specific gravity (USG), osmolality (UOSM) and total protein content (TPC) were evaluated to determine hydration status and fluid balance. Overall macronutrient and water intake were assessed using dietary records. Both UOSM and USG increased from day 3 to day 10 by 16% and 0.4% (P < 0.001), despite athletes being in their weight-stability period, and regardless of ad libitum fluid intake. Hypohydration was universally prevalent among all athletes on both test days with USG: 1.027 ± 0.003 g · mL^?1 and UOSM: 1035 ± 108 mOsmol · kg^?1. An inverse association between mean UOSM values and mean water intake was observed (R = ?0.52, P = 0.04), while TPC was not associated with any urinary dehydration markers (USG, P = 0.51; UOSM, P = 0.61). The present outcomes find that the most prevalent urinary dehydration markers used to classify hydration status in competition exhibit large variability, even during weight-stable periods.     

矿井自动排水系统综述

叙述矿井自动排水系统的组成和工作方式,介绍了矿井自动排水系统的分类和某些系统硬件的安装及作用,讲述大多数矿井自动排水系统具备的特点,最后分析系统中PCL的可靠性及其解决办法。     

农村信息化公众满意度指数模型研究

文章首先定义了农村信息化公众满意度指数的内涵,然后在定性研究和数理检验的基础上开发了农村信息化公众满意度测量表,并建立了农村信息化公众满意度指数模型.最后,依据上海郊区农村信息化调查数据,运用结构方程模型估计技术对测评模型进行了检验和参数求解.研究表明,文章建立的农村信息化公众满意度指数模型拟合度较高;另外,通过样本数据,得到了各潜在因子之间的路径系数以及可测变量的载荷系数,并对各潜在变量之间的相关关系进行了系统分析,文章在最后就研究发现的农村信息化过程不足提出了建议.     

The Reliability of Distance Run Tests for Children in Grades K—4

Abstract

The purpose of this study was to determine test–retest reliability for the 1-mile, 3/4-mile, and 1/2-mile distance run/walk tests for children in Grades K—4. Fifty-one intact physical education classes were randomly assigned to one of the three distance run conditions. A total of 1,229 (621 boys, 608 girls) complied the test–retests in the fall (October), with 1,050 of these students (543 boys, 507 girls) repeating the tests in the spring (May). Results indicated that the 1-mile run/walk distance, as recommended for young children in most national test batteries, has acceptable intraclass reliability (.83 < R < .90) for both boys and girls in Grades 3 and 4, has minimal (fall) to acceptable (spring) reliability for Grade 2 students (.70 < R < .83), but is not reliable for children in Grades K and 1 (.34 < R < .56). The 1/2 mile was the only distance meeting minimal reliability standards for boys and girls in Grades K and 1 (.73 < R < .82). Results also indicated that reliability estimates remained fairly stable across gender and age groups from the fall to spring testing periods, with the exception of the noticeably improved values for Grade 2 students on the 1-mile run/walk test. Criterion-referenced reliability (P, percent agreement) was also estimated relative to Physical Best and Fitnessgram run/walk standards. Reliability coefficients for all age group standards were acceptable to high (.70 < P < .95), except for Fitnessgram standards for 5-year-old girls on the 1-mile test for both fall and spring and for 6-year-old boys and girls on the 1-mile test administered in the spring.     

感知跳跃测量方法的可靠性研究

采用实验法及数理统计分析法，对431名大学生的感知跳跃进行多次测量，用单因素方差分析法对测量数据的可靠性进行统计分析。结果表明，性别、测量次数和取值方法是影响测量可靠性的因素。建议在运动员选材、机能评定以及全民健身体质测评工作中推广应用文章中的两种方法。     

Reliability as Argument

Reliability consists of both important social and scientific values and methods for evidencing those values, though in practice methods are often conflated with the values. With the two distinctly understood, a reliability argument can be made that articulates the particular reliability values most relevant to the particular measurement situation and then the most appropriate evidence and theory to support an argument for the presence of that value. The steps in making a reliability argument are explained and an extended example is given. The article is intended to provoke discussion, debate, and the development of additional reliability methodologies.     

基于ANSYS的Au-Al引线键合热可靠性研究

采用ANSYS有限元分析软件建立Au-Al引线键合模型考察键合区在热循环加载下的应力应变情况;并采用Coffin-Manson方程计算了在热循环加载下焊点的疲劳寿命。结果表明：随着热加载循环次数的增加,模型的应力应变将增大;施加约束后,模型的应力将减小,引线键合的寿命延长。此方法可以比较各种不同情形下Au-Al引线键合热可靠性。     

中外地理学英文论文题名的结构及常用词比较分析

[目的]探讨地理学期刊论文英文题名在句法结构和常用表达方面的撰写特点,提高我国期刊论文英译题名的质量。[方法]选取地理学中、外权威期刊2008-2012年间的2000个题名,以国际期刊为参照,对比分析我国英文题名的句法结构及常用表达特点。[结果]与国际期刊相比,我国地理学英文题名句法结构单一,过多使用名词短语结构,复合式题名与动名词短语类使用偏少;常用表达方面,某些学术套语出现率高。[结论]我国英文题名不够简洁,减弱了题名的信息性与吸引性功能。建议期刊编辑和论文作者在英译题名时注意句法结构的多样性,尽量减少母语表达习惯的影响。     

关于汽车线束系统设计及其可靠性的研究

汽车线束作为整车电气与信息系统的输送枢纽,关系着车辆在行驶过程中的安全性与电子电器工作的可靠性,经常由于汽车线束烧蚀问题导致车辆烧车,造成消费者与生产厂家巨大损失。为此,在进行整车线束系统设计的基础上,对汽车线束系统设计及其可靠性进行分析与论述。     

提高计算机网络可靠性的方法研究

为满足社会生活和国民经济对计算机的需要,对于计算机网络的可靠性就有更高的要求。本文主要对提高计算机网络可靠性的方法与途径进行了研究与探讨,对计算机网络的现状进行了分析和介绍,并提出一套具有可靠性的设计方法。