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241.
242.
Measurement and analysis of soil nitrogen and organic matter content using near-infrared spectroscopy techniques 总被引:2,自引:0,他引:2
Near infrared reflectance (N1R) spectroscopy is as a rapid, convenient and simple nondestructive technique useful for quantifying several soil properties. This method was used to estimate nitrogen (N) and organic matter (OM) content in a soil of Zhejiang Province, Hangzhou County. A total of 125 soil samples were taken from the field. Ninety-five samples spectra were used during the calibration and cross validation stage. Thirty samples spectra were used to predict N and OM concentration. NIR spectra of these samples were correlated using partial least square regression. The regression coefficients between measured and predicted values of N and OM was 0.92 and 0.93, and SEP (standard error of prediction) were 3.28 and 0.06, respectively, which showed that NIR method had potential to accurately predict these constituents in this soil. The results showed that NIR spectroscopy could be a good tool for precision farming application. 相似文献
243.
分析了大学排行榜产生的原因,指出了大学排名活动中存在的问题,如评估指标的选取、大学的不同定位等,进而指出世界范围内的排名活动会加大英语国家大学的强势,不利于发展中国家大学的发展,并认为大学排名活动应以准确的评估和科学的指标体系作为基础。 相似文献
244.
This paper addresses the developmental nature of sexually abusive behaviors as they apply to juvenile male sexual offenders. Socialization and sexual victimization are discussed. Three case histories elucidate and support the discussion of the development of victim offending. Significant treatment issues of juvenile male sexual offenders center around the sexual assault cycle which provides a framework for sexual offenders to conceptualize and understand the cognitive, behavioral, psychological, and situational factors which have resulted in their offense(s). Although sexual offenders and sexual offenses are each unique, the sexual assault cycle offers a means of addressing essential commonalities in the treatment of juvenile sexual offenders. Sexual offender specific treatment is viewed as essential for decreasing the risk of further sexual offenses, and thus decreasing the incidence of sexual victimization. 相似文献
245.
Increased activity of multiple stakeholders (e.g. agents and owners) have created new challenges for some coaches working in professional sports clubs. The purpose of this project was to draw attention to the normative or accepted practices inherent in sport work, some of the day-to-day realities of some coaches working in this context, and to understand how coaches’ perceptions of other stakeholders come to bear on their individual circumstances, career expectations/objectives and professional agency. Data were generated from semi-structured interviews with seven professional basketball coaches who worked in top-level European clubs. The analysis reveals the coach’s relationships between some owners and agents differed with respect to exercising professional agency, and, coach’s decisions and actions were tied to their professional ideals as well as understandings of what they need to undertake their work effectively and negotiation and/or adjustment strategies. Occasionally coach’s work practices could be viewed as antithetical to employment security, however, the presence of insecurity was at times embraced and used strategically to affect workers’ career decisions. Amid contemporary regional geo-political shifts, this work aids examinations of global sport settings, structures and issues that may contour sporting professionals’ lives. 相似文献
246.
Alejandro Torrejón Carlos Balsalobre-Fernández G. Gregory Haff 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(3):245-255
This study aimed to determine the suitability of the load-velocity relationship to prescribe the relative load (%1RM) in women, as well as to compare the load-velocity profile between sexes and participants with different strength levels. The load-velocity relationship of 14 men (1RM: 1.17 ± 0.19) and 14 women (1RM: 0.66 ± 0.13) were evaluated in the bench press exercise. The main findings revealed that: (I) the load-velocity relationship was always strong and linear (R2 range: 0.987–0.993), (II) a steeper load-velocity profile was observed in men compared to women (Effect size [ES]: 1.09), with men showing higher velocities for light loads (ES: ? 0.81 and ? 0.40 for the y-intercept and 30%1RM, respectively), but women reporting higher velocities for the heavy loads (ES: 1.14 and 1.50 at 90%1RM and 100%1RM, respectively); and (III) while the slope of the load-velocity profile was moderately steeper for weak men compared to their strong counterpart (ES: 1.02), small differences were observed between strong and weak women (ES: ? 0.39). While these results support the use of the individual load-velocity relationship to prescribe the %1RM in the bench press exercise for women, they also highlight the large disparities in their load-velocity profile compared to men. 相似文献
247.
Israel Halperin Dale W. Chapman Kevin G. Thompson Chris Abbiss 《Journal of sports sciences》2019,37(1):59-66
Prior research indicates that providing participants with positive augmented feedback tends to enhance motor learning and performance, whereas the opposite occurs with negative feedback. However, the majority of studies were conducted with untrained participants performing unfamiliar motor tasks and so it remains unclear if elite athletes completing familiar tasks respond in a similar fashion. Thus, this study investigated the effects of three different versions of false-performance feedback on punching force (N), pacing (force over time) and ratings of perceived exertion (RPE) in 15 elite amateur male boxers. Athletes completed a simulated boxing bout consisting of three rounds with 84 maximal effort punches delivered to a punching integrator on four separate days. Day one was a familiarisation session in which no feedback was provided. In the following three days athletes randomly received false-positive, false-negative and false-neutral feedback on their punching performance between each round. No statistical or meaningful differences were observed in punching forces, pacing or RPE between conditions (P > 0.05; ≤ 2%). These null results could stem from the elite status of the athletes involved, the focus on performance rather than learning, or they may indicate that false feedback has a less potent effect on performance than previously thought. 相似文献
248.
S. Béliard J. Cassirame G. Ennequin G. Coratella N. Tordi 《Journal of sports sciences》2019,37(6):708-716
During soccer matches, performance decrements have been reported that relate to both physical abilities and technical skills. To investigate the effects of low-frequency electrical stimulation LFES (VeinoplusSport®, Ad Rem Technology, France) administered during half-time recovery on performance alterations during the second half. Twenty-two highly trained young players undertook a soccer-match simulation (SAFT90). During half-time, they were randomly assigned to LFES group or Placebo group. Each half was split into 3 bouts of 12 minutes. Following each bout, maximal strike speed (MSS), sprint test (ST), maximal sprint accelerations (MA) and metabolic power (MP) were determined in both groups. Arterial (AF) and venous flows (VF) were measured at rest and at the end of half-time. LEFS group exhibited beneficial effects on performance compared to the Placebo group with a likely effect for MSS, ST, MA, and a possible effect for MP. AF and VF increased statistically more in LEFS group compared to Placebo group. The use of specific calf-pump LFES during half-time of a youth simulated soccer match attenuated the decrease in performance during the second half compared to Placebo group. This effect is most marked at the beginning of the second half with regards to explosive parameters. 相似文献
249.
Daniel H. Mansson Aldís G. Sigurðardóttir 《Journal of Intercultural Communication Research》2017,46(2):161-172
This study sought to address Hofstede and McCrae’s (2004) call for systematic cross-cultural comparisons of trait-like attributes. Specifically, we examined the extent to which Danish, Icelandic, Polish, and American adults’ trait affection given and trait affection received are (a) dependent on national origin, and (b) associated with Hofstede’s dimensions of cultures (i.e. individualism-collectivism, masculinity-femininity, power distance, and uncertainty avoidance). The participants (N = 606) completed a questionnaire in English that consisted of the trait affection given and trait affection received scales. Results of a multivariate analysis of variance and linear regression analyses revealed that people’s trait affection given and received are (a) dependent on national origin, and (b) associated with Hofstede’s dimensions of cultures. 相似文献
250.
Andrew Post J. Michio Clark D. G. E. Robertson T. Blaine Hoshizaki Michael D. Gilchrist 《Sports Engineering》2017,20(2):111-119
Brain injury research in sport employs a variety of physical models equipped with accelerometers. These acceleration signals are commonly processed using filters. The purpose of this research was to determine the effect of applying filters with different cutoff frequencies to the acceleration signals used as input for finite element modeling of the brain. Signals were generated from reconstructions of concussion events from American football and ice hockey in the laboratory using a Hybrid III headform. The resulting acceleration signals were used as input for the University College Dublin Brain Trauma Model after being processed with filters. The results indicated that using a filter with a cutoff of 300 Hz or higher had little effect on the resulting strain measures. In some cases there was some effect of the filters on the peak linear (8–30g) and rotational measures (1000–4000 rad/s2), but little effect on the finite element strain result (approximately 2–6 %). The short duration and high magnitude accelerations, such as the puck impact, were most affected by the cutoff frequency of different filters. 相似文献