Examining the Relationship Between Purposeful Heading in Soccer and Computerized Neuropsychological Test Performance

The purpose of this study was to determine if a relationship exists between purposeful heading in soccer and neuropsychological test performance. Automated Neuropsychological Assessment Metrics throughput scores were derived on seven subset variables that measure a variety of neurocognitive abilities. Simple Spearman's rank correlations were calculated between headers per game (HPG) and the criterion variables. Interestingly, math processing speed (Spearman's rho = .160) and continuous performance test #2 (rho = .124) had small but significant correlations; both showed improvement in performance pre- to postseason. There were no significant correlations between HPG and the other five variables. This study found no detrimental relationship between the number of purposeful headers and the neurocognitive measures in this population.     

Influence of reaction piles on test pile response in a static load test

This work presents a new analytical method to analyze the influence of reaction piles on the test pile response in a static load test.In our method,the interactive effect between soil and pile is simulated using independent springs and the shear displacement method is adopted to analyze the influence of reaction piles on test pile response.Moreover,the influence of the sheltering effect between reaction piles and test pile on the test pile response is taken into account.Two cases are analyzed to verify the rationality and efficiency of the present method.This method can be easily extended to a nonlinear response of an influenced test pile embedded in a multilayered soil,and the validity is also demonstrated using centrifuge model tests and a computer program presented in the literature.The present analyses indicate that the proposed method will lead to an underestimation of the test pile settlement in a static load test if the influence of the presence of reaction piles on the test pile response is neglected.     

理论研究中的量子化学计算方法

量子化学近阶段的高度发展使量子力学在自然科学各个领域都发挥着非常重要的作用,然而量子力学概念非常抽象,其主要包括求解Harree Fock—Roothaan方程、半经验方法和密度泛函等,用于化学反应中的理论计算,可以找出势能面的最低能量,从而对反应机理的研究有很大的促进作用．     

钛酸钡的制备及光催化性能研究

溶胶-凝胶法制备了纳米BaTiO3,用XRD、SEM分析了BaTiO3的表面形态、结晶度和粒径等,在紫外光下,以甲基橙为被降解物对其光催化活性评进行了评价。结果表明,制备得到的钙钛矿型BaTiO3,颗粒较均匀,结晶度好,其粒径约为52.4nm,样品有严重地团聚。在紫外光下,BaTiO3对甲基橙溶液有较高光催化活性,当甲基橙溶液初始浓度为10mg.L-1、pH=3、光催化剂用量2.5g.L-1、通空气量20L.h-1、光催化反应1h后,甲基橙的光催化降解率可达81.63%。     

体育锻炼对反应时的影响

本文观察了大学体育系女生和非体育系女生功率自行车上从事递增运动负荷时的反应时、心率、动作频率,并分析它们之间的相互关系。测试结果表明:体育系女生的反应时不仅在安静状态时比对照组短,而且在递增运动负荷时的反应时均短于对照组。提示:体育锻炼能提高神经肌肉的反应性,促进灵敏素质的发展,增强机体的适应能力。     

C/C＋＋数据内存分配和指针使用中若干问题的分析

从C/C＋＋编译器对数据进行内存分配的策略人手,详细阐述了内存分配策略,并对指针使用中的若干问题进行分析,给出解决策略,确保合理、正确的使用指针,从而避免产生异常和内存错误,保证程序的健壮性和正确性.     

不同水平散打运动员动作的视觉选择反应时研究

文章采用文献资料法、专家访谈法、实验法、数理统计法,以前直拳、后直拳、后鞭腿三个动作为研究题材,对不同水平12名散打运动员的视觉选择反应时进行了测定和对比研究,一方面为散打运动员反应时进一步研究提供相关数据;另一方面为散打运动员科学训练的针对性、训练手段的有效性的动作视觉判断反应能力提供参考。研究结论得出：视觉选择反应时可用做比较不同水平散打运动员的一个参考指标。运动员预知一个动作与预知有两个动作中选择一个动作时,其反应时延长。而当运动员预知二个动作中选择一个动作与预知有三个动作中选择一个动作时,其反应时延长。     

两种燃煤电厂逃逸氨的在线测量方法

燃煤电厂逃逸氨危害环境和设备,有效监测逃逸氨排放并及时采取措施是目前燃煤电厂脱硝逃逸氨监测的首要目的,同时也是一个难题。本文探讨了目前得到应用的两种逃逸氨的监测方法,对它们的特点和不足进行了讨论和说明。     

Biomechanical loading in the triple jump

The triple jump is a demanding field event in which a jumper must tolerate extremely high impact forces while maintaining high horizontal speed. The present study was designed to clarify the mechanical loading characteristics and the role of neuromuscular function in the triple jump. Seven national triple jumpers (4 males, 3 females) volunteered to perform 3-6 jumps. The mean best performances were 14.32 - 0.45 m and 11.90 - 0.28 m for males and females, respectively. The three longest triple jumps for each jumper were selected for final analysis. The mean contact times were 0.139 s (hop), 0.157 s (step) and 0.177 s (jump). The largest ground reaction forces were observed in the step (15.2 times body weight), while the highest peak pressures were recorded under the heel and forefoot. The plantar pressure of the lateral side of the forefoot was highly related to the length of the triple jump ( P ? 0.05-0.01). In addition, electromyograms of both legs suggested that mechanical loading places high demands on the neuromuscular system, as characterized by the high rate of activation in the pre-activity phase followed by high eccentric activity. Thus, the high activities of the gastrocnemius, vastus lateralis and hip extensor muscles seem to play an important role in preventing unnecessary yielding of the jumper during the braking phase.     

Experimental and model comparisons of H2O2 assisted UV photodegradation of Microcystin-LR in simulated drinking water

The degradation of Microcystin-LR （MC-LR） in water by hydrogen peroxide assisted ultraviolet （UV/H2O2） process was investigated in this paper. The UV/H2O2 process appeared to be effective in removal of the MC-LR. MC-LR decomposition was primarily ascribed to production of strong and nonselective oxidant-hydroxyl radicals within the system. The intensity of UV radiation, initial concentration of MC-LR, MC-LR purity, dosages of H2O2, the initial solution pH, and anions present in water, to some extent, influenced the degradation rate of MC-LR. A modified pseudo-first-order kinetic model was developed to predict the removal efficiency under different experimental conditions.