排序方式： 共有48条查询结果，搜索用时 328 毫秒
41.
清真慢词的网状框架及其解读 总被引：1，自引：0，他引：1
小林春代 《天津师范大学学报(社会科学版)》2001,(6):67-71
周邦彦的慢词框架呈网状。每片是一组网块，皆有一纲数目；全词又有统帅各网块的总纲。此种框架富有立体感、流动感，充满活力。它不同于复杂结构。复式是由线到面的平面结构；网状由纲、目构筑框架，是立体结构。分析复式结构宜用线索解读法，审察网状框架应试用网状解读法。前者依赖线索，后者依赖纲目，虽不丢弃线索，但对它绝非依赖，而是立于框架之颠，居高临下地俯瞰线索。 相似文献
42.
学生资助和高等教育机会均等--对中日美3国的比较分析 总被引：5，自引：0，他引：5
世界各国的高等教育规模在不断扩大，但是低收入阶层的教育机会未必在同步增长，他们需要政府的资助。另一方面，教育规模的扩大又严重压迫着财政支出。各国都处在解决机会均等和财政负担的困境中。本文将讨论学生资助的相关理论，比较多样的资助制度，从中获得启示。 相似文献
43.
This paper describes the use of Pareto-optimal solutions for the screw kick in rugby. We attempted to optimise the initial
conditions for a screw kick. The optimisation was carried out using an elitist non-dominated sorting genetic algorithm. Distance
achieved in flight is considered as an objective function, as well as the lateral deviation between the ball and the touchline,
or the flight time. Six initial conditions were defined as control parameters: the magnitude of the velocity vector, the flight
path angle, the azimuth angle, the spin rate, the pitch angle and the yaw angle. The results are summarised as follows: it
is impossible for both objective functions to be satisfied simultaneously, although the greatest distance achieved in flight
and the smallest value of the lateral deviation between the ball and the touchline, or the least flight time, is the ideal
situation. This kind of conflicting solution is called a ‘Pareto-optimal solution’. The optimal kick in Pareto-optimal solutions
made by the leg nearest the touchline produces a greater flight distance than the optimal kick in Pareto-optimal solutions
made using the leg furthest from the touchline. The initial pitch angle, which is the angle between the longitudinal axis
of the ball and the horizontal plane, should be comparable to or slightly greater than the initial flight path angle in order
to satisfy the Pareto-optimal solutions. 相似文献
44.
When the boundary layer of a sports ball undergoes the transition from laminar to turbulent flow, a drag crisis occurs whereby
the drag coefficient (C
d) rapidly decreases. However, the aerodynamic properties and boundary-layer dynamics of a soccer ball are not yet well understood.
In this study we showed that the critical Reynolds number (Re
crit) of soccer balls ranged from 2.2 × 105 to 3.0 × 105. Wind-tunnel testing, along with visualisation of the dynamics of the boundary layer and the trailing vortex of a ball in
flight, demonstrated that both non-spinning and spinning (curved) balls had lowC
d values in the super-critical region. In addition, theRe
crit values of the soccer balls were lower than those of smooth spheres, ranging from ∼ 3.5 × 105 to 4.0 × 105, due to the effects of their panels. This indicated that the aerodynamic properties of a soccer ball were intermediate between
those of a smooth ball and a golf ball. In a flow visualisation experiment, the separation point retreated and theC
d decreased in a super-critical regime compared with those in a sub-critical regime, suggesting a phenomenon similar to that
observed in other sports balls. With some non-spinning and spinning soccer balls, the wake varied over time. In general, the
high-frequency component of an eddy dissipated, while the low-frequency component increased as the downstream vortex increased.
The causes of the large-scale fluctuations in the vortex observed in the present study were unclear; however, it is possible
that a ‘knuckle-ball effect’ of the non-rotating ball played a role in this phenomenon. 相似文献
45.
In this paper we focus on individual coaching carried out by an external coach as a new pedagogical element that can impact doctoral students’ sense of progress in doctoral education. The study used a mixed-methods approach in that we draw on quantitative and qualitative data from the evaluation of a project on coaching doctoral students. We explore how coaching can contribute to the doctoral students’ development of a broad set of personal competences and suggest that coaching could work as a means to engender self-management and improve relational competences. The analysis of the participants’ self-reported gains from coaching show that doctoral students experience coaching as an effective method to support the doctoral study process. This study also provides preliminary empirical evidence that coaching of doctoral students can facilitate the doctoral study process so that the doctoral students experience an enhanced feeling of progress and that they can change their study behaviour in a positive direction. The study discusses the difference between coaching and supervision, for instance power imbalances and contrary to earlier research into coaching of doctoral students this study indicates that coaching can impact the supervisor–student relationship in a positive way. 相似文献
46.
为了提高计算机视觉领域中核心问题之一的基础矩阵估算的效率,基于条纹边界编码约束实现了一种快速估算方法．与传统的基于代数最小二乘法算法不同,该算法利用Hough变换将Hough半径作为最优化过程的最小化因子．在特定条纹边界编码的结构光投影系统模型下,利用条纹编码的共面性构造线性约束,采用Hough变换将同码像素映射到Hough空间,其交点的半径可作为最优化评价函数的最小化因子．再通过Levenberg—Marquardt最优化迭代过程估算出基本矩阵的全局最优解．实验结果表明了该算法的正确性,并证明了其可有效提高估算精度与效率． 相似文献
47.
Taishu Nakamura Tasuku Miyoshi Shota Sato Motoki Takagi Yasuhisa Kamada Yoshiyuki Kobayashi 《Sports Engineering》2018,21(3):149-159
Soccer kicks are characterized by segmental and joint rotations in multiple planes, where large discrepancies between two- and three-dimensional analyses for angular measurements of soccer kicks exist. The aim of this study was to clarify the differences in motions of the lower limbs and the pelvis required to achieve a shot without rotations as compared with an instep kick. Kinematic parameters obtained from non-rotational shots and instep kicks were analyzed using principal component analysis (PCA). The results clearly demonstrated that the PCA identified the differences in the instep kick and the non-rotational shot relative to the kinematic motions of the lower limbs and the pelvis. These findings suggest that the key issue for executing the NR shot is achieving a straight-line foot trajectory in the impact phase. 相似文献
48.