Body composition of female road and track endurance cyclists: Normative values and typical changes

The aims of this study were to describe normative values and seasonal variation of body composition in female cyclists comparing female road and track endurance cyclists, and to validate the use of anthropometry to monitor lean mass changes. Anthropometric profiles (seven site skinfolds) were measured over 16 years from 126 female cyclists. Lean mass index (LMI) was calculated as body weight?×?skinfolds^?x. The exponent (x) was calculated as the slope of the natural logarithm of body weight and skinfolds. Percentage changes in LMI were compared to lean mass changes measured using dual-energy X-ray absorptiometry (DXA) in a subset of 25 road cyclists. Compared to sub-elite and elite cyclists, world class cyclists were (mean [95% CI]) 1.18?kg [0.46, 1.90] and 0.60?kg [0.05, 1.15] lighter and had skinfolds that were 7.4?mm [3.8, 11.0] and 4.6?mm [1.8, 7.4] lower, respectively. Body weight (0.41?kg [0.04, 0.77]) and skinfolds (4.0?mm [2.1, 6.0]) were higher in the off-season compared to the early-season. World class female road cyclists had lower body weight (6.04?kg [2.73, 9.35]) and skinfolds (11.5?mm [1.1, 21.9]) than track endurance cyclists. LMI (mean exponent 0.15 [0.13, 0.18]) explained 87% of the variance in DXA lean mass. In conclusion, higher performing female cyclists were lighter and leaner than their less successful peers, road cyclists were lighter and leaner than track endurance cyclists, and weight and skinfolds were lowest early in the season. LMI appears to be a reasonably valid tool for monitoring lean mass changes.     

混联式滑车的构造及技术特点分析

深入分析了“顺穿法”和“花穿法”绕制的单行并联式滑车组在起重工作时的受力性能，通过对滑车组的偏心距和倾斜角计算，证明偏心距及倾斜角较大时对滑车组的工作和使用寿命存在很不利的影响。详细分析了混联式滑车的构造和受力性能，并对其起重时的偏心及倾斜角进行了计算，计算结果表明该新型滑车组在构造和技术上具有明显的优越性。混联式滑车于1996年获得国家发明专利。     

基于遗传算法和BP神经网络的优化设计方法

随着生产规模的复杂化、多维化和非线性等复杂特性的增加，对生产中高效的优化技术要求也越来越迫切，利用并行遗传算法和BP网络的优点，提出采用遗传算法的并行搜索和解空间搜索的优点进行网络参数的选取，利用BP网络简单和可塑性强的优点来优化样本空间，以取得整体的优化效率。     

也谈《世说新语》何以不收陶渊明

《世说新语》何以不收陶渊明?宁稼雨教授认为主要是陶氏家族在东晋没有取得世家大族的地位和声望所致。王建国博士商榷说一是与《世说新语》的收录旨趣有关,二是陶渊明那时的地位和影响远非我们现在所想象的那么重要。细较二人研究成果,究其原因主要是陶渊明不是清谈之士,其次还有家世衰微破落、文风平淡等,在当时没有产生广泛的影响和足够的声誉所致。     

小孔成像在中国古代之研究

通过对古代有关小孔成像的观察和实验记载的分析，阐明了中国古代学者在光学发展的初期所作的贡献，同时也指出由于轻理论而重现象的定性描述使得在光学上的成就远落后于西方的历史教训。     

七元素调控宏观经济

经济哲学与宏观经济调控方略在经济发展中的重要性显而易见．回顾经济学流派的各种经济政策展示了调控的显著性，在当今国际经济一体化过程中，宏观经济政策的贫乏越加显现出来．创新是首要任务．以宏观经济指标理论，政策性和阶段性的宏观调控策略．宏观经济良性循环三大任务为综合目标的七元素调控宏观经济的数学模型是三率调控宏观经济的进一步深入和细致，我们分析了税收，存款利率，贷款利率，汇率，货币发行量，国债发行量，财政预算七元素与30个宏观经济指标变量间的经验关系，并由此建立粗略的阶段性的效益矩阵作为决策的基础．利用宏观经济指标对经济的贡献率确定加权系数，并建立线性的目标函数并求出离散组合优化值，为中国宏观经济的发展献一点调控策略。供政府部门的决策者参考．     

计算机补码概念探究

计算机补码表示法是计算机相关原理的重要知识点,更是计算机运算方法乃至运算器设计的基础.采用类比法,结合日常生活中的实例和计算机硬件特点,从＂模＂的概念入手,依次从补码概念的引入、补码的性质、由补码求真值的方法和引入补码的真正意义四个方面对计算机补码的概念进行了探究.     

Global existence and blow-up of solutions to reaction-diffusion system with a weighted nonlocal source

In this paper, we study a semi-linear reaction-diffusion system with a weighted nonlocal source, subject to the null Dirichlet boundary condition. Under certain conditions, we prove that the classical solution exists globally and blows up in finite time respectively, and then obtain the uniform blow-up rate in the interior.     

Fe^3＋掺杂TiO2可见光催化降解酸性红的研究

研究了在可见光条件下,用实验室合成的Fe3＋掺杂TiO2为催化剂催化降解酸性红染料,重点考察了Fe3＋的掺杂量、Fe3＋掺杂TiO2为催化剂的添加量、酸性红溶液的初始浓度、溶液pH值、光照时间对降解率的影响.实验结果表明,Fe3＋掺杂比为1.5%、催化剂用量为1.5 g/L、pH为2.0、质量浓度为40 mg/L的酸性红100 mL,用白炽灯光照降解酸性红30 min,酸性红降解率可达98.45%.     

主体材料对磷光染料掺杂聚合物薄膜光谱性质的影响

研究了以（PPQ）2Ir（acac）为客体,分别以PFO、PVK、PFB和PFG四种不同聚合物为主体掺杂体系的光谱性质.各种材料的紫外-可见吸收光谱和光致发光光谱的性质表明PVK和PFO与客体之间可以发生有效的能量转移.此外,与光致发光谱不同,发光器件电致发光光谱有较纯的红光发射,表明除了能量转移之外,电荷捕获也是实现器件红色发光的主要原因之一.