Estimating shear strength of high-level pillars supported with cemented backfilling using the HoekeBrown strength criterion

Deep metal mines are often mined using the high-level pillars with subsequent cementation backfilling(HLSCB)mining method.At the design stage,it is therefore important to have a reasonable method for determining the shear strength of the high-level pillars(i.e.cohesion and internal friction angle)when they are supported by cemented backfilling.In this study,a formula was derived for the upper limit of the confining pressure σ3max on a high-level pillar supported by cemented backfilling in a deep metal mine.A new method of estimating the shear strength of such pillars was then proposed based on the Hoek eBrown failure criterion.Our analysis indicates that the horizontal stress σhh acting on the cemented backfill pillar can be simplified by expressing it as a constant value.A reasonable and effective value for σ3max can then be determined.The value of s3max predicted using the proposed method is generally less than 3 MPa.Within this range,the shear strength of the high-level pillar is accurately calculated using the equivalent MohreCoulomb theory.The proposed method can effectively avoid the calculation of inaccurate shear strength values for the high-level pillars when the original HoekeBrown criterion is used in the presence of large confining pressures,i.e.the situation in which the cohesion value is too large and the friction angle is too small can effectively be avoided.The proposed method is applied to a deep metal mine in China that is being excavated using the HLSCB method.The shear strength parameters of the high-level pillars obtained using the proposed method were input in the numerical simulations.The numerical results show that the recommended level heights and sizes of the high-level pillars and rooms in the mine are rational.

Research on the Path of Cultivating High-Level Technical and Skilled Talents in Vocational Undergraduate Colleges and Universities

This paper explores strategies to cultivate high-level technical talents in vocational undergraduate colleges by analyzing their development,the essence of such talents,and proposing several key measures.Strategies include optimizing professional settings and curricula,enhancing school-enterprise cooperation and the integration of industry-university-research,improving teaching staff quality and educational standards,and expanding international cooperation.The importance of policy support and funding and establishing robust quality assurance systems is emphasized for effectively cultivating skilled talents in vocational undergraduate colleges.

Analysis on the Physical Characteristics of High-level Football Players

This article uses the literature data method and literature review method to review and collect relevant literature,and summarizes and analyzes the representative views on domestic physical fitness research.After summarizing and summarizing,it is considered that:physical energy is the basic athletic ability of the human body expressed through physical qualities such as strength,speed,endurance,coordination,flexibility,and sensitivity,and is an important component of athletes'athletic ability.The level of physical fitness is closely related to the morphological characteristics of the human body and the functional characteristics of the human body.The morphological characteristics of the human body are the structural basis of its physical fitness,and the functional characteristics of the human body are its biological functional basis.As the basic ability of athletes,physical fitness is an important factor of athletes'competitive ability.Each competitive sport has its own specific physical characteristics and training rules and methods.Grasping these laws has very important guiding significance for the improvement of athletes'sports level.

Correlation analysis of national elite Chinese male table tennis players’ shoulder proprioception and muscle strength

BACKGROUND Shoulder is the most injured part in table tennis players,and it takes multiple roles in transmitting power and striking the center of the ball during the stroke.Proprioception is strongly correlated with high level of athletic performance.It is customary to assume that there is a correlation between proprioception and muscle strength and therefore proprioceptive assessment and rehabilitation is often neglected.AIM To investigate the correlation between isokinetic muscle strength and proprioception in the internal and external rotation muscle groups of elite Chinese male table tennis players,to provide reference for physical training and rehabilitation of elite table tennis players.METHODS A total of 19 national elite table tennis players from the Chinese National Table Tennis Team were recruited in this research.All of them had more than 10 years training experience and had participated major competitions such as the National Games and World Youth Championships.IsoMed 2000 was used to test the peak torque of internal and external rotation isokinetic concentric contraction of the athletes'bilateral shoulder joints at low speed(60°/s)and high speed(180°/s)respectively;IsoMed 2000 was used to conduct the Joint Position Reproduction test to evaluate the athletes'proprioceptive ability capacity at low speed(60°/s)and high speed(180°/s)respectively.If the data satisfied the normal distribution,the correlation between the differences in peak torque s and angles in different directions was analyzed using a Pearson simple linear model;otherwise,Spearman correlation analysis was used.The comparison of proprioceptive ability between the table tennis racket-holding hand and non-racket-holding hands was performed using independent samples t-test if the data satisfied a normal distribution;otherwise,the Mann-Whitney U test was used.RESULTS There was no direct linear correlation between the strength and proprioceptive correlation analysis at slow speed(60°/s)and fast speed(180°/s)in the racket-holding hand;At the slow speed(60°/s)and fast speed(180°/s),there was no correlation between muscle strength and proprioception in the non-racket-holding hand except for the internal rotation variable error(VE)and external rotation relative peak torque,which showed a moderate positive correlation(r=0.477,P<0.05),(r=0.554,P<0.05).The internal rotation’s constant error(CE)and VE were 1.06±3.99 and 2.94±2.16,respectively,for the racket-holding hand,and-3.36±2.39 and 1.22±0.93,respectively,for the non-racket-holding hand;the internal rotation’s CE,VE of the racket-holding hand was lower than that of the non-racket-holding hand,and there was a highly significant difference(P<0.01).CONCLUSION There was no correlation between muscle strength and proprioceptive function in the internal and external rotation of the racket-holding hand’s shoulder in elite Chinese male table tennis players.These results may be useful for interventions for shoulder injuries and for the inclusion of proprioceptive training in rehabilitation programs.

Glycogen and amyloid-beta: key players in the shift from neuronal hyperactivity to hypoactivity observed in Alzheimer's disease?

Introduction：Alzheimer’s disease（AD）begins to develop decades prior to its clinical manifestation（Sperling et al.,2011）,and while it is the most common form of dementia,as of yet there is no cure.Two of the most researched pathological features contributing to disease development are the extracellular amyloid plaques composed of amyloid-beta proteins（Aβ）and neurofibrillary tangles of tau proteins.Another feature of AD is the progression of early neuronal excitability/hyperactivity to silencing/hypoactivity（Palop and Mucke,2010）,

The Distribution of Benefits for Players in Agricultural Industrial Chain

Players of the agricultural industrial chain pursue their own profit maximization,which can lead to conflicts of interest and affect the stability of the industrial chain. Therefore,fair and reasonable profit allocation mechanism is the key to guaranteeing the development and strengthening the strategic alliance relationship between participate members. Shapley model is an effective method to solve the profit distribution in cooperative relations. But it does not consider the three factors: risks faced by players during the operation of the agricultural industrial chain,technology innovation ability,and the degree of participating in the cooperation. So,correction factors are introduced to modify the Shapley value model,in order to make the distribution of benefits more equitable and reasonable,and effectively guide practice.

The Prevalence and Characteristics of Thoracic Outlet Syndrome in High School Baseball Players

Thoracic outlet syndrome (TOS) is one of the common neurovascular disorders of the upper extremities, and the compression or traction of the brachial plexus is the main pathology. We hypothesized that baseball players are more likely to be affected by TOS compared with other overhead-throwing athletes because of strenuous use of their throwing arm. The purpose of this study was to investigate the prevalence and clinical characteristics of TOS in high school baseball players. One thousand two hundred eighty-eight high school baseball players were included in this study. The prevalence of symptomatic TOS and its association to disorders of the upper extremities were investigated. The prevalence of symptomatic TOS was 32.8%. Age- and position-adjusted logistic regression analysis revealed that subjects with symptomatic TOS were at significantly higher risk of shoulder and/or elbow pain (odds ratio [OR]: 1.96, 95% confidence interval [CI]: 1.50 - 2.58) and a higher recurrence rate of shoulder and/or elbow pain during the previous season (OR: 2.38, 95% CI: 1.87 - 3.04). As for physical findings, subjects with symptomatic TOS were also at significantly higher risk of MUCL tenderness (OR: 2.53, 95% CI: 1.83 - 3.50), positive milking maneuver, (OR: 2.63, 95% CI: 1.78 - 3.91), positive subacromial impingement sign (OR: 1.92, 95% CI: 1.20 - 3.07), and positive posterior impingement sign (OR: 2.34, 95% CI: 1.67 - 3.28) compared to the subjects without symptomatic TOS. It is necessary to recognize that TOS is not a rare pathology in overhead-throwing athletes, especially baseball players, and that players with symptomatic TOS are at significantly higher risk of shoulder/elbow pain.

Differences in body components and electrical characteristics between youth soccer players and non-athletes

Many previous studies have focused on youth soccer player injuries without body component analysis compared to non-athletes. Only a few studies which have investigated body components of youth soccer players, and studies that look at electrical characteristics used by rheobase and chronaxie as well as body components are even scarcer. Therefore, we feel that there is a need for a study investigating objective clinical analysis of the body components (body structure and body composition) and electrical characteristics of both youth soccer players and non-athletes. Sixty subjects participated in our study, comprising of thirty youth soccer players and thirty non-athletes. The Inbody 520 was used to measure and analyze body composition and the Duo 500 was employed to measure electrical characteristics. It was observed that the soccer players showed markedly lower total impedance compared to the non-athletes. In both legs, it was particularly noted that there were significant differences between the right and left sides. The soccer players showed a higher skeletal muscle mass and lean/ideal lean × 100% compared to the non-athletes. Furthermore, the soccer players had a lower rheobase and higher chronaxie. A comparison of the genders showed a similar pattern. In this study, we were able to separate the differences in body components and electrical characteristics between the subject groups using a systemic approach. Future studies on diverse types of athletes would contribute further to the development of clinical physiotherapy and sports rehabilitation.

What factors are associated with premature death among professional baseball players in Japan?

The aim of this study is to clarify factors related to premature death among Japanese professional baseball players by a case-control analysis. The subjects are two matching groups of 622 Japan Professional Baseball (JPB) league players, those deceased and those surviving. Cases and controls are matched by birth year. All players debuted on the first string between 1934 and 2003, and are listed in The Official Baseball Encyclopedia of Japan. To compare means and frequencies of characteristics between deceased and surviving groups, t-tests and chi-square tests were used. A logistic regression analysis was assessed contributions of each independent variable on death. Significant differences between deceased and surviving players were observed in this study;deceased players had higher body mass indexes and longer careers. Furthermore, logistic regression analysis confirmed that body mass index and career length were statistically significant determinants of death for baseball players. This is the first report to examine factors of death for professional baseball players except employing data attained from Major League Baseball.

Association between Daily Living Walking Speed and Lifestyle and Physiological Factors in Older, Female Pokémon GO Players

Background: Walking speed is a reliable barometer of adverse health outcomes, particularly among older people. Few studies evaluated factors associated with daily actual walking speed, rather than that measured in a laboratory setting or self-reported data. Methods: In a joint effort with The Pokémon Company, we recruited study participants through a women’s magazine and analyzed data from 63 Pokémon GO players. We measured the true walking speed in daily life among older women using a data-gathering mobile application. Then, using questionnaire survey data collected on these participants in 2019, we estimated the relationship between walking speed and their lifestyle and physiological factors. In the analysis, we employed a bi-directional stepwise linear regression approach, with the Akaike information criterion (AIC) for variable selection. Results: The mean age of the 63 participants was 63.03 years (standard deviation, SD 7.46);the average walking speed was 4.56 km per hour (SD 1.54);and 52 (82.5%) and 55 (87.3%) participants answered that they had excellent/good health physically and mentally, respectively. After adjusted for covariates in a stepwise regression approach, we identified a significant association between −1.33 (95% confidence intervals −2.52 to −0.15) km/hour lower walking speed and the experience of outdoor falls within a year. We also demonstrated that the walking speed was 1.07 (0.33 to 1.81) km/hour faster for those who had played Pokémon GO before the study started. Conclusions: The true walking speed in daily life among older women was measured by a data-gathering mobile application. Although all participants were women recruited on a voluntary basis with an understanding of the purpose of the study, and the surveys were conducted at a cross-sectional setting, a significant relationship with the experience of outdoor falls was demonstrated. We also present evidence suggesting a possible relationship between Pokémon GO play and faster walking speed.

Minor Players, Major Drivers

If light is the way to dispel darkness,then Beijing-based Landsky Technology Group Co.,Ltd.narrates a bright and fascinating way of displaying optical technology.“Light is no longer just for illuminating objects.A well-designed lighting scheme can make people truly sense their surroundings,”Liang Ye,a senior manager at Landsky,said.Coming in from this perspective,the hi-tech enterprise in the field of lighting technology has focused its research and development(R&D)efforts on enriching the relationship between light and life,light and space,as well as that between light and nature.

ZTE Co-organized Global WiMAX Operation Congress in Singapore with Leading Industry Players

ZTE Corporation was among the key participants in the recently concluded WiMAX Operation Congress,

Leave or Stay?Antecedents of High-level Talent Migration in the Pearl River Delta Megalopolis of China:from a Perspective of Regional Differentials in Housing Prices

Rapid urbanization and population growth have triggered an increase in urban housing demand and rising housing prices,which can influence the migration intention of high-level talents.Much work within the literature has focused more on the migration of the general public.However,antecedents of migration intention and the impact of housing prices on the migration of high-level talents remain unclear.Therefore,based on the push-pull theory,this study investigates the influencing factors of talent migration intention and explores the role of housing prices.This study reveals a complex mechanism underlying migration decisions by using logistic regression models and survey data of high-level talents in the Pearl River Delta(PRD)megalopolis of China.The results indicate that:1)in high house-price regions,social integration is the primary push factor,and the main factors for retaining talents are the expectation of future work and intimate family relationships;2)in medium house-price regions,the main factors that attract talents are the current salary level and close family ties;3)in low house-price regions,living convenience is a determining factor in retaining talents.This study provides a new perspective for talent mobility research and offers valuable inputs for retaining and attracting talents in different economic development regions.Findings are of great significance for formulating talent introduction policies and forming a new pattern of rational spatial docking and effective allocation of human resources.

On appraisal models of basketball players'athletics a-bilities

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An Exploratory Practice of Integration of Industry and Education in High-level Programming Language Course in the Background of New Engineering

This paper analyzes some problems of the current teaching situation in the course High-level Programming Language,such as the lagging content of the course compared with technology development,the emphasis on theory rather than on practice,the low enthusiasm of students for learning,and the weak practical ability of students.In response to the needs of enterprises for talents under the background of New Engineering,especially the cultivation of students’adaptability and practical abilities towards future industries to improve students’knowledge and problemsolving abilities to keep up with the modern technology,this paper proposes the ways and methods to reform and explore the teaching content and teaching methods by integrating industry and education,assisting teaching according to industrial demands,and lowering technology barriers of new technology.The practical effect is evaluated through a survey in class and the follow-up questionnaire after class,and the results show that the effect of the practice is effective.

An Intial Study On the Training Of Point Man In Young Basketball Players

To train young point man is an important link in raising China′s basketball level.It consists of selecting good successors and train them. Criteria for the selection include ideology and behaviour, figure, physical fitness, type of nerves and genetic factors. The selection is conducted among 8 10-year-old children to find good successors.

Carving out a Niche African football players feature prominently in the Chinese leagues

The Chinese Football Association Super League （CSL） has broken yet another record. Indeed, the league＇s record recruitment budget of 388 million euros （$342.76 million） yeas broken this season. In 2018, more than 470 million euros （$415.19 million） have been spent on retaining the best football stars that have come to China in recent years, as well as on attracting even more talented footballers.

Research on the Space Construction of the Novel Ready Player One

The novel Ready Player One shows Ernest Cline’s ability of space construction,and demonstrates charm and artistic value of the virtual fantasy space it depicts.It is a science fiction with perfect combination of ideological content and artistic form.This thesis aims to discuss the Ernest Cline’s construction of the virtual pace and the real space in Ready Player One and the function of their construction.In real space,the environment is awful and dilapidated,and people’s lives are depressed.While in the virtual space,the world is colorful and people have varied ways of entertainment to fulfill their mind.This Thesis summarizes the effects brought by both the real space and virtual space for Ready Player One.With such a strong contrast,the conflict between the two spaces promotes the narrative process and also highlights the theme of the novel.