X. Wang

The performance of the grinding wheel demonstrably affects the machining efficiency and the quality of the workpiece. Therefore, it is essential to evaluate the wear of the wheel and then operate the dressing or replacement in time. The wear procession of the wheel was monitored and evaluated systematically in this paper. A surface grinding experiment was performed by using an alumina wheel to grind the workpiece made of Cr12. The grinding force and the grinding temperature were monitored and measured while the wheel grinds the workpiece. The surface topography of the wheel was also being observed. The distribution of the gray value of pixels in the image of the wheel surface was analyzed by the method of the histogram. Processing of the binary image of the wheel was performed after determining the gray threshold of the gray value. Then, the blockading and the wearing area on the grinding wheel were calculated. Moreover, the relation of the projection area of a single abrasive derived from theory and derived by image recognition was studied. The results of the grinding experiment show that wheel performance degradation occurs when the material removal volume reaches 210 mm3/mm. At this time, the ratio of blockage area on the grinding wheel reaches 13.4%. The percentage of the wearing area is 9.5%. The method of image recognition combined with grinding temperature is workable to realize monitoring and evaluating the wear of wheels on site without unloading them.

According to resource limitation, a more realistic pest management is that the impulsive control actions should be adjusted according to the densities of both pest and natural enemy in the field, which result in nonlinear impulsive control. Therefore, we have proposed a Beddington–DeAngelis interference predator-prey model concerning integrated pest management with both density-dependent pest and natural enemy population. We find that the pest-eradication periodic solution is globally stable if the impulsive period is less than the critical value by Floquet theorem. The condition of permanent is established, and a stable positive periodic solution appears via a supercritical bifurcation by bifurcation theorem. Finally, in order to investigate the effects of those nonlinear control strategies on the successful pest control, the bifurcation diagrams showed that the model exists with very complex dynamics. Consequently, the resource limitation may result in pest outbreak in complex ways, which means that the pest control strategies should be carefully designed.

Alterations in dural venous sinus hemodynamics have recently been suggested as the major contributing factors in venous pulsatile tinnitus. Nevertheless, little is known about the association between real-time alterations in hemodynamics and the subjective perception of venous PT. This study aimed to investigate the hydroacoustic correlations among diverticular vortices, mainstream sinus flow, and PT using various Doppler ultrasound techniques. Nineteen venous PT patients with protrusive diverticulum were recruited. The mainstream sinus and diverticular hemodynamics before and after ipsilateral internal jugular vein compression were investigated using an innovative retroauricular color-coded Doppler method to examine the correlation between the disappearance of PT and hemodynamic alterations. To reveal the hydroacoustic characteristics of disparate segments of venous return, a computational fluid dynamics technique combined with the transcranial color-coded Doppler method was performed. When the ipsilateral IJV was compressed, PT disappeared, as the mean velocity of mainstream sinus flow and diverticular vortex decreased by 51.2 and 50.6%, respectively. The vortex inside the diverticulum persisted in 18 of 19 subjects. The CFD simulation showed that the flow amplitude generated inside the transverse–sigmoid sinus was segmental, and the largest flow amplitude difference was 20.5 dB. The difference in flow amplitude between the mainstream sinus flow and the diverticular flow was less than 1 dB. In conclusion, the sensation of PT is closely associated with the flow of kinetic energy rather than the formation of a vortex, whereby the amplitude of PT is correlated to the magnitude of the flow velocity and pressure gradient. Additionally, the range of velocity reduction revealed by the RCCD method may serve as a presurgical individual baseline curative marker that may potentially optimize the surgical outcomes.

Optimization for vertical vibration performance of a rail-train coupling system is investigated in this paper with the introduction of inerters for both primary and secondary suspensions. A model of a typical Chinese passenger train that travels on a traditional rail with track, sleepers, and ballast is simulated. The goal is to improve the ride quality for the train and vibration attenuation for the rail system in response to track irregularities. Optimizations for only inertance and all suspension parameters are carried out by the particle swarm algorithm. Performance benefits for both the train and the rail system are demonstrated and suspension layouts with inerters connected in parallel and series are compared with the traditional one in both time domain and frequency domain.

In this article, we introduce a hierarchy on the class of non-archimedean Polish groups that admit a compatible complete left-invariant metric. We denote this hierarchy by $\alpha $ -CLI and L- $\alpha $ -CLI where $\alpha $ is a countable ordinal. We establish three results: (1) G is $0$ -CLI iff $G=\{1_G\}$ ; (2) G is $1$ -CLI iff G admits a compatible complete two-sided invariant metric; and (3) G is L- $\alpha $ -CLI iff G is locally $\alpha $ -CLI, i.e., G contains an open subgroup that is $\alpha $ -CLI. Subsequently, we show this hierarchy is proper by constructing non-archimedean CLI Polish groups $G_\alpha $ and $H_\alpha $ for $\alpha

The aim of this study was to examine the interactive effects of situational variables on teams’ technical performance in the UEFA Champion League. Match data of 19 technical actions and events were collected and classified into three groups during eight seasons. Repeated-measures analysis of variance was used to identify the differences in the technical performances among teams. Results showed that the significant differences in the technical performance between the group stage and the knockout stage were only found in dribble and yellow card. However, differences in the variables related to goal scoring and offense were more significant than in the variables related to defense under the comparisons across competition situations, and the differences in the variables related to defense were mainly detected in the yellow card. The number of variables that showed significant differences among match location and match outcome in the group stage were less than in the knockout stage. Therefore, the identified key performance indicators by considering the interactive effects of situational variables may provide detailed and practical insights for coaches to develop useful training interventions and match strategies for upcoming match playing in specific competition situations.

Anticipation is a crucial perceptual-cognitive skill in fast-ball sports, and the effect of high anxiety on performance has attracted more attention from sports psychologists. Related studies mainly focus on the effect of anxiety on influencing processing efficiency and attentional control during information processing in sport. Attentional Control Theory has been supported by several studies. However, these studies have been criticized by the low ecological validity of task design, such as neglecting the dynamic process of anticipation, and inadequate performance analysis, such as analyzing response accuracy and time separately. Using temporal occlusion paradigm, we tested ACT in a dynamic anticipation process. Eighteen skilled and eighteen less-skilled table tennis players were required to anticipate the serves of opponents under dynamic task constraints and anxiety conditions. High cognitive state anxiety decreased processing efficiency for both groups whereas performance effectiveness did not differ. In addition, it negatively affected processing efficiency in early anticipation compared with late anticipation tasks, suggesting that high cognitive state anxiety may have a greater impact on top-down attentional control. Our findings provide support for ACT and show that anxiety impairs anticipation efficiency and performance, possibly due to an ineffectively attentional shift from external kinematic cues to internal long-term working memory. Findings also have implications for the adaptation of attentional strategies and anxiolytic training.

The aim of cognitive diagnosis is to classify respondents' mastery status of latent attributes from their responses on multiple items. Since respondents may answer some but not all items, item-level missing data often occur. Even if the primary interest is to provide diagnostic classification of respondents, misspecification of missing data mechanism may lead to biased conclusions. This paper proposes a joint cognitive diagnosis modeling of item responses and item-level missing data mechanism. A Bayesian Markov chain Monte Carlo method is developed for model parameter estimation. Our simulation studies examine the parameter recovery under different missing data mechanisms. The parameters could be recovered well with correct use of missing data mechanism for model fit, and missing that is not at random is less sensitive to incorrect use. The Program for International Student Assessment 2015 computer-based mathematics data are applied to demonstrate the practical value of the proposed method.

This paper includes seven chapters. The first chapter discusses the purport and the structure of Vimalakirti Nirdesa Sutra. Its purport is inconceivable liberation-development and liberation of living beings-purification of Buddha-fields. These three items are one essentially, the inconceivable liberation being the essence of its purport and the development and liberation of living beings and the purification of Buddha-fields being the function of it. Essence and function are identical. This sutra has a structure that goes forward step by step and arranges in a crisscross pattern. The second chapter discusses the thought of sunya. On one hand, this sutra follows and develops the thought of sunya in the Prajn~a^pa^ramita^-su^tra while paying much emphasis on the middle-way sunya, on the other hand, it is characterized by two points in the way of its thought of sunya: all things standing on the root which is baseless and surpassing it within e qu-sunya. The third chapter argues the thought of middle way and non-discrimination. The domain of the bodhisattva embodies the thought of middle way. The thought of middle way of this sutra influenced greatly Na^ga^rjuna who claimed eight-not middle way. Jizang and Zhiyi followed and developed the thought of his. Nonduality is without discrimination. The dharma of nonduality is middle way dharmata^. The theory of dharmata^ is profound and abstruse, being without any form and beyond speech. Entering-the Dharma-door of nonduality has three layers of meaning. Nonduality is inconceivable and entering-the Dharma-door of nonduality is inconceivable liberation. The idea of nonduality of this sutra had a profound impact on Huineng’s Tanjing and Jizang’s thought of nonduality in four-layer two truths. The theory of sunya, middle way and non-discrimination discussed in the above two chapters, is the way of thinking of this sutra which is named as the negative affirming. Without the way of thinking of this kind, no sentient beings were gifted with the great compassion and skill in liberative technique.Without it, there were no developing and liberating living beings and purifying Buddha-fields. The fourth chapter discusses the thought of inconceivable liberation. In general, the Inconceivable is that which is beyond contemplation or conceptualization, beyond linguistic expression. In this sutra, apart from the above significance, the Inconceivable is equal to Liberation. The essence of inconceivable liberation is developing and liberating living beings and purifying Buddha-fields, is being released in liberation without abandoning the passions that are the province of the world, is following the way to attain the qualities of the Buddha, is neither destroying the compounded nor resting in the uncompounded, is being beyond the world without abandoning it. The fifth chapter argues the probability and method of developing and liberating sentient beings, that is, the thought of the Buddha-qualities and skill in liberative technique. The family of the Tathagatas', being constituted by all passions, is different from the true mind, the pure mind, the tatha^gatagarbha or the Buddha-nature. So it is certain that the thought of the Buddha-qualities would develop into the idea which insists on all sentient beings having the Buddha-nature. Zhiyi’s theory of evil-nature was evolved from the thought of the family of the Tathagatas'. The skill in liberative technique has many meanings: (1) A method, a means, a device for saving sentient beings; "expedient means" (upa^ya). "Excellent method for converting beings" (upa^ya-kau/salya). The wisdom of being able to save sentient beings by knowing discriminated phenomena. A temporary teaching established in order to lead sentient beings to the true teaching. This is a subject of primary importance in the Lotus Sutra. (2) A plan, scheme, design (a^rambha). (3) Usage of metaphor in teaching. (4) Chinese Buddhists utilized the doctrine of expedient means to help deal with the hermeneutical problem of reconciling the disparities among the different teachings attributed to the Buddha-to explain that the differences in the teachings of the Buddha delivered in his forty-nine year ministry were the result of the different audiences he addressed. The sixth chapter discusses how to purify the Buddha-fields. When we say that the purity of the Buddha-field reflecting the purity of one’s own mind, the mind is not the transcendental pure one, but the empirical one after arousing the thought of intention to achieve enlightenment. The purity of one’s own mind leading to the purity of the Buddha-field, means that the pure Buddha-field are constructed not only by purifying his own mind but also by purifying all living beings’ minds. Huineng’s idea of “one’s own mind is Buddha immediately” and the argument of “one’s own mind is pure Buddha-field immediately” are greatly different from the thought of the purity of one’s own mind leading to the purity of the Buddha-field. The seventh chapter discusses the relation between this sutra and householder-Buddhism and the secularization of Buddhism. This sutra doesn’t gives theoretical arguments for the householder-Buddhism and the secularization of Buddhism.

The “dynamic turn” in the field of second language acquisition catalyzed scholarly devotion to the complex dynamic relationships between learner and teacher variables and various academic emotions. As such, the present study examined the varying effects of the aforementioned variables on the constructs of positive and negative flow, and determined their strongest predictors, respectively. This study used a mixed-method approach to collect data from 607 Chinese English-as-a-Foreign-Language learners. In stage one of the research, the researcher first assessed the participants’ levels of positive flow and negative flow in a blended learning context, then performed Pearson correlation analysis to confirm a significant, but weak positive relationship between positive flow and negative flow. Then, significant difference tests were run to determine the varied effects of those variables on flow. Finally, two multiple regression analyses were conducted to identify five predictors of positive flow, with the biggest contribution coming from learners’ attitudes toward the foreign language, and three predictors of negative flow, with the learners’ major accounting for the majority of variance. In the second stage of the research, a qualitative corpus was constructed, based on accounts of classroom experiences from 71 participants of the total sample, and further illustrated the quantitative findings. Pedagogical implications for educational psychologists and teachers of second and/or foreign languages are addressed.