广东省体育专业学生就业意向及压力现状调查

对广东省体育专业学生的就业意向及压力进行调查,结果表明:广东省体育专业学生对毕业后第一份工作的工资待遇、地点均有较高的期待;在职业选择上,主要是体育教师、公务员、跟着父母或亲戚自主创业.近九成的学生存在就业压力,其中逾四成学生感到压力很大.学生期望学校给予以下帮助:增加学生的实习、实践机会;多进行就业策略、形势分析;在大学低年级的时候,依据学生的就业意向进行具体分类、定向辅导;设置2个专项,并针对专选学生给予更多的实践机会等.     

应力腐蚀条件下的承压设备去应力设计

根据产生应力腐蚀的条件,提出了锅炉压力容器等承压设备去应力设计的概念,分别阐述了它的三个组成部分——运行工艺设计、结构设计和热处理工艺设计。并结合一种LHS型燃油(气)锅炉烟管的碱脆和压力容器的现场制造,提出了具体的去应力结构和处理办法。     

科技期刊编辑的心理压力及心理调适

对科技期刊编辑存在的多种心理压力进行分析,并针对此,就编辑如何调适自身心理进行探讨,以期减少编辑心理疾病,促进心理健康,以更好的心境和充沛的精力投入到编辑工作中去.     

列车荷载对下穿盾构隧道影响的模型试验

为研究地面线路运营对下穿盾构隧道结构的影响规律,基于相似比理论建立室内大型试验模型,模拟上部列车荷载作用下土层及其内部盾构隧道结构的受力变形过程,总结变形规律。结果表明,模型试验能够较好地反映外部荷载影响下土层以及内部盾构隧道结构的受力和变形特性;地表列车荷载在土层传递过程中,同一层面上沿地面线路方向的土压力大于两侧土压力,远离线路的地层受列车荷载影响相对较小,同一竖向截面土压力变化量由上至下逐渐减小,即外部荷载对浅层土的影响明显大于深层土;盾构隧道在地表列车行驶过程中,环向出现背车面受拉迎车面受压的受力特性,呈斜向压扁,纵向应变从中间交叉点向盾构隧道两侧逐渐减小,呈下凹压弯;盾构隧道埋深越小,受地表荷载影响越显著,增大一倍埋深对应纵向应变最大值减小约44.5%。     

Acute cardiovascular responses to interval exercise: A systematic review and meta-analysis

ABSTRACT

Interval exercise training is increasingly recommended to improve health and fitness; however, it is not known if cardiovascular risk is different from continuous exercise protocols. This systematic review with meta-analyses assessed the effect of a single bout of interval exercise on cardiovascular responses that indicate risk of cardiac fibrillation and infarction compared to continuous exercise. Electronic databases Medline, CINAHL, Embase, Scopus and Cochrane were searched. Key inclusion criteria were: (1) intervals of the same intensity and duration followed by a recovery period and (2) reporting at least one of blood pressure, heart rate variability, arterial stiffness or function. Cochrane Risk of Bias tool and GRADE approach were used. Meta-analyses found that systolic blood pressure responses to interval exercise did not differ from responses to continuous exercise immediately (MD 8 mmHg [95% CI ?32, 47], p = 0.71) or at 60 min following exercise (MD 0 mmHg [95% CI ?2, 1], p = 0.79). However, reductions in diastolic blood pressure and flow-mediated dilation with interval exercise were observed 10–15 min post-exercise. The available evidence indicates that interval exercise does not convey higher cardiovascular risk than continuous exercise. Further investigation is required to establish the safety of interval exercise for clinical populations.     

Interval exercise induces milder respiratory responses compared to continuous exercise

ABSTRACT

The purpose of this study was to explore the respiratory response of acute interval and continuous exercise (CE) of low and high intensity. Fourteen recreational athletes (7 men and 7 women; VO₂max = 35.7 ± 6.1 mlkg^–1min^–1) performed a bout of continuous and a bout of interval exercise (IE) both consisted of 5-min cycling at low intensity [80% of the power output (W) of the predetermined gas exchange threshold (GET) (80%W_GET)] and 5-min cycling at high intensity {W_GET plus the work rate corresponding to 50% of the difference between peak power output (PPO) at oxygen uptake (VO₂max) test and the W_GET [W_GET + 0.50 Δ(PPO – W_GET)]}. CE compared to IE induced significant higher heart rate and ventilation as well as significant higher levels of mouth occlusion pressure for 0.1 s (P_0.1) (P < 0.05) during low and high intensities. Our results indicate that CE stimulates respiration more than IE when the exercise is performed at the same relative intensity.     

利用差压变送器检测流量

采用差压变送器直接测量流量，输出电流与被测流量将是非线性关系。若在差压变送器的电磁反馈机构中串接一个电流平方器，就会使输出电流与被测流量呈线性关系。便于显示、记录、调节。为此设计了一个由分离元件构成的电流平方器电路，就能解决非线性问题。     

全自动电冰箱保护器

本文介绍了一种只用一块NE555时基电路和少量分立元件，就能制作一个具有过压，欠压和断电延迟三种保护功能的全自动电冰箱保护器。     

液压系统中液流压力损失的相关分析

分析液压系统中压力损失产生的原因,液流压力损失与雷诺数的关系,局部压力损失在不同管道下的计算;影响液流压力损失的因素,减少液压系统中压力损失产生的相关方法。     

高校实施压力管理的问题与对策

目前高校教师的身体健康与心理健康令人担忧,造成这种状况的直接原因在于高校教师承受着各种过大的压力。国内外有关压力与压力管理的研究已取得很多成果,很多知名企业在帮助员工减轻压力方面也有不少措施办法与经验。高校教师的压力类型与表现有其特殊性,目前的高校压力管理措施还存在问题与认识误区;高校实施压力管理,可借鉴企业的有效方法,维持合理适度的良性压力,倡导并帮助教师健康快乐工作。