近代开滦煤矿矿难及其发生的自然原因缕析

近代开滦煤矿在其生产经营繁荣的背后,矿难却是频发不断、难以遏止,矿难造成的惨重伤亡更是让人触目惊心。文章对矿难的总体情况及其发生的自然原因进行了缕析。     

论江湖义气在黑社会性质组织中的影响

江湖义气作为黑社会性质组织亚文化的核心,是拴束组织成员的纽带,对黑社会性质组织成立与发展起着重要的促进作用。黑社会性质组织中江湖义气的内核是获取最大化的非法经济利益,其内核促使黑社会性质组织获取最大化的非法经济利益。探究江湖义气在黑社会性质组织中的影响,剖析黑社会性质组织的文化根源,有利于针对性地建立防控黑社会性质组织犯罪的长效机制。     

中国物理学会的成立及其抗战前的主要活动

我国现代物理学的发展起步较晚,因此现代意义上的专门化物理学会在中国的成立具有重要的意义,是我国物理学发展具有里程碑式的事件.清末民初中国出现了向西方学习的热潮,一批留学欧美和日本的留学生在上个世纪二三十年代陆续学成归国,他们把物理学的种子带了回来,并生根发芽结果,物理学人的专门化组织--中国物理学会经过李书华、叶企孙、吴有训等物理学前辈的努力终于在1932年8月于清华大学成立.中国物理学会的成立促进了我国物理学研究和教学事业发展,在抗日战争前取得了令人可喜的成绩.     

关于灾害报道的英文编译——以汶川地震为例

灾害报道编译,是自成一类的新闻传播方式.以汶川地震报道的汉英编译为例,重点探讨如何运用有效的翻译方法及时、准确地报道灾害破坏,描述施救行动,悼念遇难同胞并以此争取国际社会的同情及人道主义援助,激发全世界人们联合起来共同面对自然灾害.     

武汉抗战期间募捐特点

1937年12月,南京沦陷。尽管当时已经宣布重庆为陪都,但是,包括财政部、内政部、外交部在内重要的、关键的政府职能部门以及国民党中央党部、国民政府军事委员会等正面战场最高决策指挥机构,都直接迁往武汉办公,武汉成为实际上的首都;与此同时,分布在战区的商界、文化界等各种社会团体也纷纷聚集武汉,他们与武汉民众一起开展了义薄云天的救亡运动,武汉成为全国抗战的中心。在国民政府、湖北省地方政府和各种社会团体的共同参与下,武汉的募捐活动呈现出新的特点,这主要表现在征募的组织性、动员宣传的规模性、群众参与的广泛性和募捐运动的多样性。这一时期的募捐运动为以后国统区开展募捐运动提供了宝贵的经验借鉴,也揭开了此后以重庆为中心整个国统区大规模募捐运动的序幕。     

包头供电局治理外力破坏对策研究

分析历年来包头供电局近年在预防输电线路外力破坏过程中存在的输电线路遭受外力破坏的几种类型及原因,总结防范输电线路的相关经验,提出有效防治的措施。     

Resultant muscle torque and electromyographic activity during high intensity elastic resistance and free weight exercises

Abstract

The purpose of this study was to quantify and compare Resultant Muscle Torque (RMT) and muscle activation (EMG) pattern, during resistance exercise comprising eight repetitions maximum (8 RM) biceps curl with elastic resistance and free weight exercise. Sixteen male and female recreationally active subjects completed 8 RM biceps curl by each of three modalities of resistance exercise: (i) dumbbell (DB), (ii) elastic tubing with original un-stretched length at the commencement of contraction (E0), and (iii) elastic tubing with 30% decrement of original length (E30) at the commencement of contraction. The magnitude of muscle activation, external force, acceleration as well as range of motion (ROM) were quantified and synchronised by specific software. The data were collected from all eight repetitions but the first (initial), the fifth (middle) and the eighth (last) repetitions were selected for further data analysis. Each selected repetition was partitioned into a concentric and eccentric phase and then each phase was further divided into three equal segments (3 concentric and 3 eccentric = 6 segments per repetition). The EMG and RMT data demonstrated a bell-shaped muscle activation and muscle torque production pattern for the three modes of exercise. The E30 resulted in 15.40% and 14.89% higher total EMG (µV) as well as 36.85% and 17.71% higher RMT (N · m) than E0 and DB, respectively (all P <0.05). These findings support the contention that an elastic resistance device (E30) has the capacity to provide an appropriate high resistance stimulus to meet the training requirement of elite athletes.     

Contraction force specificity and its relationship to functional performance

Abstract

Best practice for improving strength and power through resistance strength training has been the subject of much research and subsequent conjecture. Much of the conjecture can be attributed to methodological discrepancies. The type of dynamometry used in testing, the training experience of research participants, the specific technique employed in a lift, and the methods of collection and calculation all impact on the final variables of interest. This review examines contraction force specificity by first addressing the methodological issues surrounding our interpretation of the results. Then we address the kinematics and kinetics associated with single and multiple repetitions in relation to the development of strength, power, and functional performance. This discussion provides the delimitations for analysis of subsequent training studies. Finally, recommendations are formulated with the aim of assisting assessment and training practice as well as providing directions for future research. The results of this review suggest that the enhancements in performance resulting from resistance training are context specific in experienced resistance-trained participants. Thus, specific conditioning could be required to achieve improvements in functional performance in this group.     

The effects of eccentric phase duration on concentric outcomes in the back squat and bench press in well-trained males

ABSTRACT

The velocity and magnitude in which the eccentric phase of an exercise is completed directly affects performance during the concentric phase. Therefore, the purpose of this research was to investigate the effects of eccentric phase duration on concentric outcomes at 60% and 80% of one-repetition maximum (1RM) in the squat and bench press. Sixteen college-aged, resistance-trained males completed 1RM testing, established normative eccentric durations, and performed fast (0.75 times normative) and slow (2.0 times normative) metronome-controlled eccentric duration repetitions. Outcome measures assessed during the concentric phase were: average concentric velocity (ACV), peak concentric velocity (PCV), rating of perceived exertion (RPE), range of motion (ROM), and barbell path. Eccentric duration was significantly and inversely correlated with ACV at 60% (r = ?0.408, p = 0.004) and 80% (r = ?0.477, p = 0.001) of 1RM squat. At 60% of 1RM squat, both fast and slow eccentric conditions produced greater (p < 0.001) PCV than normative duration with fast also producing greater PCV than slow (p = 0.044). Eccentric duration had no impact on RPE, ROM, or barbell path. Our results report for the first time that resistance-trained males performing a deliberately faster eccentric phase may enhance their own squat and bench press performance.     

Effect of loading on peak power of the bar,body, and system during power cleans,squats, and jump squats

Abstract

Nine males (age 24.7 ± 2.1 years, height 175.3 ± 5.5 cm, body mass 80.8 ± 7.2 kg, power clean 1-RM 97.1 ± 6.36 kg, squat 1-RM = 138.3 ± 20.9 kg) participated in this study. On day 1, the participants performed a one-repetition maximum (1-RM) in the power clean and the squat. On days 2, 3, and 4, participants performed the power clean, squat or jump squat. Loading for the power clean ranged from 30% to 90% of the participant's power clean 1-RM and loading for the squat and jump squat ranged from 0% to 90% of the participant's squat 1-RM, all at 10% increments. Peak force, velocity, and power were calculated for the bar, body, and system (bar + body) for all power clean, squat, and jump squat trials. Results indicate that peak power for the bar, body, and system is differentially affected by load and movement pattern. When using the power clean, squat or jump squat for training, the optimal load in each exercise may vary. Throwing athletes or weightlifters may be most concerned with bar power, but jumpers or sprinters may be more concerned with body or system power. Thus, the exercise type and load vary according to the desired stimulus.