二粒子纠缠GHZ型量子隐形传态(英文)

提出了一个通过三粒子纠缠GHZ状态传输未知的二粒子纠缠GHZ型状态的方案,对应于发送者测量结果的酉变换被详细给出,且成功的概率是1.为了推广该方案,提出了利用四粒子纠缠GHZ态作为量子信道的单受控隐形传态方案,并推广单受控到多受控的情况.在通过六粒子纠缠GHZ态单受控三方传态的基础上,提出了多受控多方传态方案.在这些控制方案中,任何一个接收者在其它接受者和受控者的帮助下都可重构原始态.但是任何一个控制者仅仅依靠其自己的粒子是不能恢复到原始态.我们获得了接受重构的酉运算与发送者、控制者和其它接受者的测量结果之间关系,且总体方案成功的概率是1.     

Bristol Palin: the pedagogical media spectacle of a sexual abstinence ambassador

This paper explores the public political media spectacle of Bristol Palin's teenage pregnancy and her status as a single mother through the lens of a critical feminist discourse analysis. The author explores how cultural anxieties over teenage sexuality and unintended pregnancy in America are constructed when the pregnant teen is the daughter of an ambitious politician who is White, upper-middle class, and holds evangelical Christian beliefs. From pregnant teen thrust into the media spotlight by her politically ambitious mother to ambassador of sexual abstinence, the pedagogical media spectacle of Bristol Palin promoting abstinence is unique and can be understood as part of a broader postfeminist media culture in which the articulation of feminist empowerment principles, such as female agency and reproductive choice, is subverted within the neoliberal discourse of personal responsibility and financial independence.     

Should educators and parents encourage other-gender interactions? Gender segregation and sexism

We investigated gender differences in the association between gender-segregated peer preferences and sexism in adolescents (15–17 years, 60 boys and 85 girls). To assess gender-segregated peer preferences, adolescents nominated peers for interaction in two contexts: ‘hanging out’ at home and working on a school project. The Modern Sexism Scale [Swim, J. K., K. J. Aikin, W. S. Hall, and B. A. Hunter. 1995. “Sexism and Racism: Old-Fashioned and Modern Prejudices.” Journal of Personality and Social Psychology 68 (2): 199–214] measured two dimensions of sexism: Antagonism towards Women's Demands (believing feminist issues are unimportant) and denial of continuing discrimination (believing gender discrimination no longer exists). For boys, Antagonism towards Women's Demands was associated with gender-segregated peer preferences in the school and home context. For girls, Denial of Continuing Discrimination was associated with gender-segregated peer preferences in the home context. Results are informative for educators and for other professionals interested in reducing inequality and sexism among adolescents.     

Figure Skating

The purpose of this study was to compare triple (T) and quadruple (Q) toe‐loop figure skating jumps and quantify basic characteristics of these jumps to provide information to coaches that will assist them in teaching quadruple toe‐loops to elite figure skaters. High‐speed video was taken during men's practice and competition sessions at the 2002 Salt Lake City Winter Olympics; three‐dimensional analyses of selected triple and quadruple jumps were completed. The most significant difference between triple and quadruple toe‐loops was an increase in rotational velocity in the air. Additionally, increased vertical velocity at take‐off and subsequent time in the air were also observed. Three main conclusions were developed: 1) The timing of rotation of the hips and shoulders was different for quadruple toe‐loops compared to triples with the differences being observed before toe‐pick; 2) Increases in rotational velocity occurred primarily as a result of the skaters assuming different body positions from take‐off through landing which resulted in tighter rotating positions for longer durations of the jump; 3) Greater vertical velocity was gained during the propulsive phase due to the extension of the legs during the press off the ice.     

从中国古代正史体育文献看我国单项体育运动的发展

采用文献资料、逻辑分析和现象学等研究方法,从正史中的体育文献着手分析评述了我国古代单项体育运动发展,根据其特点把我国古代的单项体育运动分为军事性、竞技性、娱乐性和保健性的几类,并对其发展规律进行了分析.     

2012年澳网男单决赛选手发球技战术统计分析

运用文献资料法、数理统计法、录像观察法和比较法等研究方法对2012年澳网男单决赛选手的发球环节中一发成功率、一发得分率、二发得分率、发球速度以及发球落点等进行统计分析,结果表明一发和二发球的平均速度具有明显差别,而且随发球区域的不同一发二发的落点选择也不同。但是总体趋势都是意图控制对方的反手和中路,尤其是二发中路偏重。     

轮滑运动进入奥运会的可行性研究

运动文献资料法、归纳演绎法等研究方法,对轮滑运动的发展历史和健身价值进行分析。认为轮滑运动具有观赏性强、刺激性大、娱乐性广等特点,并具有一定的健身价值和社会价值,符合奥运会的选项要求。对轮滑进入奥运会的可行性因素进行了初步探讨。     

On Judged Sports

Whereas Bernard Suits argued that judged sports such as diving and figure skating are aesthetic performances rather than games, I argue that they’re simultaneously performances and games. Moreover, their two aspects are connected, since their prelusory goal is to dive or skate beautifully and the requirement to do somersaults or triple jumps makes achieving that goal more difficult. This analysis is similar to one given by Scott Kretchmar, but by locating these sports’ aesthetic side in their goals rather than in their rules, it better captures the importance of beauty in them.     

Influence of starting position on finishing position in World Cup 500 m short track speed skating

Abstract

Top short track speed skaters and their coaches have suspected that starting positions influence finishing positions, especially in the 500 m racing distance. The objective of this study was to examine systematically the influence of starting position on finishing position in 500 m short track speed skating. The data analysed included results from World Cup 500 m races ranging from the 1999 – 2000 season through to the end of the 2003 – 2004 season. All 500 m men's and women's races with four skaters starting and finishing (preliminaries, heats, quarter-finals, semi-finals and finals) were included in the data set. The association between starting position and finishing position was examined using Kendall's tau. Results show that for both sexes, there is a significant positive correlation between starting position and finishing position (P < 0.001). This effect is generally more pronounced in semi-finals and finals than it is in preliminaries, heats and quarter-finals. Strategies to counter this inequity are proposed, drawing upon similar experiences in other sports.     

Ice friction of flared ice hockey skate blades

Abstract

In ice hockey, skating performance depends on the skill and physical conditioning of the players and on the characteristics of their equipment. CT Edge have recently designed a new skate blade that angles outward near the bottom of the blade. The objective of this study was to compare the frictional characteristics of three CT Edge blades (with blade angles of 4°, 6°, and 8°, respectively) with the frictional characteristics of a standard skate blade. The friction coefficients of the blades were determined by measuring the deceleration of an aluminium test sled equipped with three test blades. The measurements were conducted with an initial sled speed of 1.8 m · s^?1 and with a load of 53 kg on each blade. The friction coefficient of the standard blades was 0.0071 (s=0.0005). For the CT Edge blades with blade angles of 4°, 6°, and 8°, friction coefficients were lower by about 13%, 21%, and 22%, respectively. Furthermore, the friction coefficients decreased with increasing load. The results of this study show that widely accepted paradigms such as “thinner blades cause less friction” need to be revisited. New blade designs might also be able to reduce friction in speed skating, figure skating, bobsledding, and luge.