Hilbert空间中算子框架的稳定性研究

文章利用算子理论的方法研究了Hilbert空间中算子框架的稳定性,给出了算子框架分别在一列算子的不同方式的扰动下的稳定性结果和在一个Bessel列的扰动下的稳定性结果。     

奇异积分算子在H^1（R^n）空间上的有界性

利用H1（Rn）的原子分解理论以及h1（Rn）（局部Hardy空间）的分子理论,证明了一类奇异积分算子从H1（Rn）到h1（Rn）有界.作为应用,得到了若A′∈L （R1）,则Cauchy积分算子CA从H1（R1）到h1（R1）有界.     

量子力学中的超算符概念

对量子力学中的线性算符概念进行了研究,通过建立算符函数的微分学引入了超算符概念,并给出了各类超算符的定义,在此基础上利用超算符概念分析量子力学中的典型问题,结果表明超算符概念在量子力学中具有广泛的应用,且使物理意义更加清晰.     

用算符法求解物理学非线性微分方程

引入特征算符和相应的算符定理,用算符法把物理学中的非线性微分方程的叠代解表示成展开的幂级数,结合辅助函数,得出所要求的级数解,提供一种用算符法求解物理学非线性微分方程的技巧.     

Kinematic analysis of the drag flick in field hockey

Attaining high speed of the stick head and consequently of the ball is essential for successful performance of the drag flick in field hockey, but the coordination pattern used to maximise stick head speed is unknown. The kinematics of the drag flick was studied in ten elite hockey players who performed twenty shots each towards a target located 1.5 m high. A 150 Hz active marker motion analysis system was used, alongside two force plates to detect foot touchdown. Angular velocity and contribution to stick endpoint speed of upper body joints were analysed. Repeated measures ANOVA was used to compare timing of onset and peak angular velocities between joints. Participants used a kinematic pattern that was close to a proximal-to-distal sequence. Trunk axial rotation and lateral rotation towards the target, right wrist flexion and left wrist extension were the main contributors to stick endpoint speed. Coaches should emphasise trunk rotations and wrist flexion and extension movements for maximising stick head speed. Given the high level of the participants in this study, the coordination of joints motions, as reported here, can serve as a guideline for drag flick training.     

基于CWAA算子的战略新兴产业集群核心竞争力评价

构建一套基于CWAA算子的战略性新兴产业集群核心竞争力评价体系;通过文献调查法和统计分析法,构建战略性新兴产业集群核心竞争力评价指标体系,即产业集群经营规模、组织管理能力、集群成长能力、技术创新能力、知识管理能力、集群协同水平;提出利用OWA算子对多种赋权法进行加权组合,确定评价指标权重;基于CWAA算子,给出一种战略性新兴产业集群竞争力群决策方法;通过实证验证本文方法的可行性和合理性。     

QFD中客户需求权重确定的区间二元语义方法

客户需求权重的确定是质量功能展开中最关键、最核心的阶段。针对客户需求评价者可能作出的不同语言评价集,提出一种基于标准化区间二元语义的多属性评价方法。定义区间二元语义、集结算子和可能度排序方法,介绍基于区间二元语义模型的模糊多属性信息评价算法,并通过实例验证该方法的可行性。     

Effects of changing speed on knee and ankle joint load during walking and running

Joint moments can be used as an indicator of joint loading and have potential application for sports performance and injury prevention. The effects of changing walking and running speeds on joint moments for the different planes of motion still are debatable. Here, we compared knee and ankle moments during walking and running at different speeds. Data were collected from 11 recreational male runners to determine knee and ankle joint moments during different conditions. Conditions include walking at a comfortable speed (self-selected pacing), fast walking (fastest speed possible), slow running (speed corresponding to 30% slower than running) and running (at 4 m · s^?1 ± 10%). A different joint moment pattern was observed between walking and running. We observed a general increase in joint load for sagittal and frontal planes as speed increased, while the effects of speed were not clear in the transverse plane moments. Although differences tend to be more pronounced when gait changed from walking to running, the peak moments, in general, increased when speed increased from comfortable walking to fast walking and from slow running to running mainly in the sagittal and frontal planes. Knee flexion moment was higher in walking than in running due to larger knee extension. Results suggest caution when recommending walking over running in an attempt to reduce knee joint loading. The different effects of speed increments during walking and running should be considered with regard to the prevention of injuries and for rehabilitation purposes.     

Krasnoselskii不动点定理的一个应用

不动点理论是研究方程解的存在性的一种强有力的工具.本文主要考虑了一类特殊的积分方程,并应用Krasnoselskii不动点定理得到了该类积分方程解的存在性.     

An Analysis of Interpersonal Function of the Dialogues in the Film The King’s Speech

Based on the framework of Halliday’s theory of interpersonal function, this study intends to analyze the dialogues in the film The King’s Speech from the three aspects of mood type, modal operator and ...