模内微装配成型微装配界面熔接黏附脱黏剥离特性

如何准确预测和调控微装配界面熔接黏附脱黏剥离特性是聚合物模内微装配成型制备高性能微型机械运动的关键科学与技术问题。针对这一关键科学与技术问题,构建了模内微装配成型微型机械运动副界面熔接黏附脱黏剥离行为的模拟仿真平台和注射温度-材料副界面脱黏剥离断裂韧性参数-界面熔接黏附脱黏剥离特性的关联关系。研究表明,运动副微装配界面的启裂应力、临界应变能释放率和完全脱黏剥离驱动力与二次成型熔体注射温度呈正相关关系,降低二次成型注射温度,可以明显减小界面的启裂应力和临界应变能释放率,抑制微装配界面的熔接黏附,有利于降低微装配界面熔接黏附脱黏剥离的驱动力,提高微装配界面的可运动性能。

Assessing acceptance in mindfulness with direct-worded items:The development and initial validation of the Athlete Mindfulness Questionnaire

Purpose:The purpose of the current study was to develop and validate a sport-specific mindfulness measure,the Athlete Mindfulness Questionnaire(AMQ),through 5 related studies using 4 separate samples of Chinese athletes.The AMQ is a 3-factor measure designed to assess mindfulness that reflects present-moment attention,awareness,and acceptance in a sport context.Methods:In Study 1,an initial pool of items was generated based on previous literature,existing mindfulness scales,as well as interviews with and feedback from the athletes,coaches,and mindfulness experts.Initial support for the 3-factor structure of the AMQ was established via exploratory factor analysis in Study 2,and cross-validated through confirmatory factor analysis in Studies 3 and 4.In Study 5,a modified 3-factor AMQ with direct-worded acceptance items was examined in a fourth independent sample.Results:Convergent and concurrent validities of the acceptance subscale failed to be established in Studies 3 and 4 which may be due to the inattention and confusion of the athletes whilst interpreting the reverse-worded items.A modified 16-item AMQ in Study 5 displayed satisfactory model fit and acceptable internal consistencies.Most importantly,convergent and concurrent validities of the 16-item AMQ were supported.The3 subscales showed significant positive associations with mindfulness,flow,well-being,and positive affect and significant negative associations with experiential avoidance,burnout,and negative affect.Conclusion:The AMQ is a psychometrically sound measure of mindfulness in a sport context.The importance of using direct-worded acceptance items is discussed.

A comparison study of two Tricept units for reconfigurable parallel kinematic machines

This paper presents a comparison study of workspace and dexterity of two Tricept units for Reconfigurable Parallel Kinematic Machines （RPKMs）. The modular leg of RPKMs is designed and the RPKMs can be built by changing tile setting of modules. A compositive kinematic model is developed accordingly. The inverse kinematics and Jacobian of these two Trieept units are analyzed. Considering workspaee volume and dexterity, the effeets of geometric size of some modules on the two Trieept units are discussed. In the end, comparison results of these two Tricept units are. given. The eomparison of two kinds of Parallel Kinematic Machines （PKMs） can be of help in the design and configuration planning of the RPKMs.

A complexity-scalable software-based MPEG-2 video encoder

With the development of general-purpose processors (GPP) and video signal processing algorithms, it is possible to implement a software-based real-time video encoder on GPP, and its low cost and easy upgrade attract developers' interests to transfer video encoding from specialized hardware to more flexible software. In this paper, the encoding structure is set up first to support complexity scalability; then a lot of high performance algorithms are used on the key time-consuming modules in coding process; finally, at programming level, processor characteristics are considered to improve data access efficiency and processing parallelism. Other programming methods such as lookup table are adopted to reduce the computational complexity. Simulation results showed that these ideas could not only improve the global performance of video coding, but also provide great flexibility in complexity regulation.

Effect of Humus on Activity of Mineral-Bound Hg: III.Effect on Leachability and Transfer of Mineral-Bound Hg Under Acid Leaching Condition

Effects of humus fractions (fulvic acid, brown humic acid and grey humic acid) on the leachability and transferring activity of five types of mineral-bound Hg were investigated. Under the acid leaching condition: fulvic acid could promote leachability and vertical transference of all the mineral-bound Hg. Brown humic acid could retard the leaching and transferring processes of CaCO3-Hg, Fe2O3-Hg, MnO2-Hg and kaolinite Hg but not bentonite-Hg. Grey humic acid could greatly enhance residing ability of the mineral-bound Hg in the soil column and restrain them from vertical transferring. The effect of humus on leachability and transferring activity on the mineral-bound Hg was closely related to its ability to convert the mineral-bound Hg into organic-bound form and the transferability of the latter in the soil column. The characteristics of the mineral-bound Hg in speciation were the internal factors that determined the extent and rate of the influence of the humus.

The Description of Motion in Tunisian Arabic： A Thinking-for-Speaking Approach

Motion event typology predicts that languages can be divided into either satellite-framed, verb-framed or serial-framed languages. However, an increasing number of studies show that languages within the same type predispose their speakers to describe motion events differently. Based on the narrative behavior of 15 native speakers, we provide evidence that suggests Tunisian Arabic （TA） is an untypical verb-framed language. One the one hand, TA conflates motion and path meanings in the main verb, and native speakers adhere to the boundary-crossing constraint. On the other hand, the availability of a rich manner verb lexicon combined with the availability of mono-verbal clauses ready to be coordinated asyndetically, encourages TA speakers to attend to the manner of motion more often than reported for a typical verb-framed language （e.g., Spanish）. Based on these fmdings, we conclude that predictions based on motion event typology are best considered as guidelines, and not as an accurate reflection of how motion meanings may be lexicalized and expressed in individual languages

Validity and reliability of eating disorder assessments used with athletes： A review

Background： Prevalence of eating disorders （EDs） among college-aged athletes has risen in recent years. Although measures exist for assessing EDs, these measures have not been thoroughly reviewed in athletes. This study reviewed the validity and reliability evidence of the commonly used measures for assessing EDs in athlete populations aged 18--26 years. Methods： Databases were searched for studies of regarding ED on male and/or female athletes. Inclusion criteria stated the study （a） assessed EDs in an athlete population 18--26 years of age and （b） investigated EDs using a psychometric measure found valid and/or reliable in a non- athlete population and/or athlete population. Results： Fifty studies met the inclusion criteria. Seven and 22 articles, respectively, studied EDs behaviors in male and female athletes whereas 21 articles studied EDs in combined-gender samples. The five most commonly used measures were the Eating Attitudes Test （EAT）, Eating Disorder Inventory （EDI）, Bulimia Test-Revised （BULIT-R）, Questionnaire for Eating Disorder Diagnosis （QEDD）, and the Eating Disorder Examination Questionnaire （EDE-Q）. Conclusion： Only seven studies calculated validity coefficients within the study whereas 47 cited the validity coefficient. Twenty-six calculated a reliability coefficient whereas 47 cited the reliability of the ED measures. Four studies found validity evidence for the EAT, EDI, BULIT-R, QEDD, and EDE-Q in an athlete population. Few studies reviewed calculated validity and reliability coefficients of ED measures. Cross- validation of these measures in athlete populations is clearly needed.

Integrable System and Motion of Curves in Projective and Similarity Geometries

Based on the natural frame in the projective geometry, motions of curves in projective geometry are studied. It is shown that several integrable equations including Sawada-Kotera and KK equations arise from motion of plane curves in projective geometries. Motion of space curves described by acceleratlon field and governed by endowing an extra space variable in similarity geometry P^3 is also studied.

Ecology, Environment, Sustainability： The Development of the Environmental Movement in Israel

The article surveys the development of the environmental movement in Israel from the establishment of the state through the present day. Based on trends and transformations in the institutional planning system, it appears that activism by environmental movement organizations in Israel can be divided into three sub-periods： the establishment period, marked by the Sharon Plan, the founding of the Society for the Protection of Nature in Israel and MALRAZ--Council for the Prevention of Noise and Air Pollution in Israel, and the enactment of the Kanovitch Law and the National Parks and Nature Reserves Law （1963）. The next phase of institutionalization is characterized by the establishment of designated institutional bodies--the Nature Reserves Authority, the National Parks Authority and the Environmental Protection Service, and their integration into the national planning system. The institutionalization period concludes with the establishment of the Ministry of the Environment （1989） and the transition to the third period, sustainability. Prominent during this period is a trend toward multidimensional proactive environmental planning and policymaking, reaching across many areas and including extensive regulation As far as environmental organizations are concerned, these three periods comprised a framework of cultural action in which they developed, acted and shaped environmental discourse and practice in Israel. Based on other studies, the article offers a model that illustrates the development of the environmental movement while emphasizing the interaction between individual actors, local organizing and national organizations. Finally, some characteristics and insights regarding activism by environmental organizations in Israel are suggested.

Structure reliability analysis based on supercavity vehicle steady motion

Taking the steady motion status as a starting point,according to the modeling of actual state of theoretical analysis,a predigested model of supercavity vehicle was established,and relationship expressions of these angles were obtained when the movement of supercavity vehicle was stable.A theoretical analysis on the stability of underwater high-speed movement in the movement simulation program was conducted and the simulation results were given.Then the force status of the supercavity vehicle was elicited from the results.The finite element analysis was carried out based on the stability at all angles obtained from simulation results.Taking a pilot model as example,the Monte Carlo method was adopting to analyze the reliability with the given state of force and displacement.The result indicates that this method is feasible.

Modeling of Bubble Motion in Two Dimensional Space

The equations of motion of a bubble, expanding adiabatically through an incompressible viscous fluid, are deduced when the centre of the bubble moves in a vertical plane in the presence of gravitational acceleration, acting vertically downwards. The non-linear equations of motion obtained are solved numerically for different values of the various parameters of the problem. The path traced by the centre of the bubble and velocity of the centre, the change of radius R with time, and the influence of the buoyancy force, which is experienced by the expanding bubble for different values of the gravitational acceleration on these quantities, are investigated. The radius R（t） of the bubble is found to vary periodically with time when the acceleration due to gravity is small. But when the acceleration due to gravity increases, this periodicity in the value of R（t） with t is lost. The influence of viscosity in determining the periodicity of the bubble motion is also investigated.

Differentiability of stochastic differential equations driven by the G-Brownian motion

In this paper,we study the differentiability of the solutions of stochastic differential equations driven by the G-Brownian motion with respect to the initial data and the parameter.

The predictability of atmospheric and oceanic motions:Retrospect and prospects

This paper reviews the historic understanding of the predictability of atmospheric and oceanic motions, and interprets it in a general framework. On this basis, the existing challenges and unsolved problems in the study of the intrinsic predictability limit(IPL) of weather and climate events of different spatio-temporal scales are summarized. Emphasis is also placed on the structure of the initial error and model parameter errors as well as the associated targeting observation issue. Finally, the predictability of atmospheric and oceanic motion in the ensemble-probabilistic methods widely used in current operational forecasts are discussed.The necessity of considering IPLs in the framework of stochastic dynamic systems is also addressed.

Null Controllability of Some Reaction-Diffusion Systems with Only One Control Force in Moving Domains

In this article, the authors establish the local null controllability property for semilinear parabolic systems in a domain whose boundary moves in time by a single control force acting on a prescribed subdomain. The proof is based on Kakutani＇s fixed point theorem combined with observability estimates for the associated lineaxized system.

Bifurcation and chaos of an airfoil with cubic nonlinearity in incompressible flow

Using a combination of analytical and numerical methods, the paper studies bifurcations and chaotic motions of a two-dimensional airfoil with cubic nonlinearity in incompressible flow. One type of critical points (characterized by a negative eigenvalue, a simple zero eigenvalue and a pair of purely imaginary eigenvalues) for the bifurcation response equations is considered. With the aid of the normal form theory, the explicit expressions of the critical bifurcation lines leading to incipient and secondary bifurcations are obtained. The stability of the bifurcation solutions is also investigated. By using the undetermined coefficient method, the homoclinic orbit is found, and the uniform convergence of the homoclinic orbit series expansion is proved. It analytically demonstrates that there exists a homoclinic orbit joining the initial equilibrium point to itself, therefore Smale horseshoe chaos occurs for this system via Si'lnikov criterion. The system evolves into chaotic motion through period-doubling bifurcation, and is periodic again as the dimensionless airflow speed increases. Numerical simulations are also given, which confirm the analytical results.