大气压等离子体刷对PET表面改性的实验研究     

姚雪瑞  刘仁静  李雪辰 《滨州学院学报》2019,(2):74-78

为了提高聚对苯二甲酸乙二醇酯(PET)的亲水性,采用大气压等离子体刷对其进行表面改性。利用接触角测量仪、拉曼光谱和扫描电子显微镜对PET改性前后的性能进行了分析和表征。经过等离子体刷在PET表面单次扫描之后,PET表面的水接触角随着扫描速度的增加而增加。此外,水接触角随着耗散功率的增加而减小。通过拉曼光谱发现经等离子体处理之后的PET表面会产生含氧极性基团,如C-O、C=O、C-O-C和OH。通过扫描电子显微镜观察到,含氧极性基团包含在低分子量氧化材料中。  相似文献   

激光等离子体相互作用的有效度规     

王龙  季沛勇  BAI Ying 《上海大学学报(英文版)》2008,12(4):318-322

The interactions of laser field with plasma are studied by using the analog model of gravity. The interactions of laser field with plasma are regarded as an equivalent effective geometry. An effective metric for a plasma electron is developed. Validity of the metric is confirmed in the limit of non-relativity. The three-dimensional equation of motion for a plasma electron is derived from the general covariant equation of motion. The ponderomotive force and the Abraham＇s force are directly obtained from the three-dimensional equation.  相似文献   

Activating lignite and sludge by electro-hydraulic impulse     

陈德淑 《重庆大学学报(英文版)》2003,2(2)

1. Introduction At present, it is necessary to use fertilizer to ensure the stable and high agricultural productivity. However, as we all know, the fertilizer not only decreases the self-fertility of soil, but also is accompanied with pesticide. Food poisoning caused by remnant pesticide in fruits and vegetables is often reported, and in such cases, chronic poisoning is the majority. The remnant pesticide accumulates in body gradually, and then induces kinds of disease. As reported, the Miyu…  相似文献   

用ICP-AES法测定中药野马追的微量元素     

陈健 《金陵科技学院学报(社会科学版)》2003,18(1):34-35

用电感耦合等离子体原子发射光谱ICP-AES同时测定了野马追中的Fe、Al、Si等20种元素,用干法对样品进行处理.干法是先将样品600℃高温灰化,再用浓硝酸消解.将ICP-AES法用于野马追微量元素的测定具有简单、快速、准确度高的优点.  相似文献   

高效液相色谱法测定人血浆中氯氮平浓度     

吴岚 《岳阳职业技术学院学报》2007,22(4):58-61

目的建立测定人血浆中氯氮平浓度的高效液相色谱法。方法以DiamonsilTM C18反相柱(150mm×4.6mm,5μm)为色谱柱,流动相为0.03mol.L-1醋酸铵-甲醇(25:75);流速:0.8 ml.min-1;柱温:40°C;检测波长:254nm。以乙酸乙酯与二氯甲烷(80:20)为提取剂。结果氯氮平的高、中、低(1000.0,400.0,10.0 ng.mL-1)3种浓度平均回收率分别为105.36%,98.63%,97.46%,日内、日间差RSD均低于7%(n=5);分析方法的检测限为5.0 ng.mL-1;线性范围为10.0-1000.0 ng.mL-1。曲线方程:C=25.69F 3.47,r=0.9997(n=10)。结论:该方法灵敏、准确、简单、快速,可用于临床血药浓度监测和药动学研究。  相似文献   

Prenatal programming of sporting success: Associations of digit ratio (2D:4D), a putative marker for prenatal androgen action,with world rankings in female fencers     

Raúl Bescós  Marc Esteve  Jordi Porta  Mercè Mateu  Alfredo Irurtia  Martin Voracek 《Journal of sports sciences》2013,31(6):625-632

Abstract

Associations of the second-to-fourth digit ratio (2D:4D), a putative marker for prenatal androgen action, and of absolute finger length, a putative marker for pubertal–adolescent androgen action, with sport performance were examined in a multinational sample of 87 world-class women épée fencers. Lower (masculinized) digit ratios correlated, although not significantly so, with better current and highest past world rankings. These correlations were significant for right-hand 2D:4D with controls for the most salient factors for 2D:4D (ethnicity) and world rankings (years of international experience, height, and weight). Longer (masculinized) fingers correlated strongly with better current and highest past world rankings; these correlations became insignificant with the same controls. Replicating previous evidence for fencers, left-handedness was much more prevalent in this sample (21%) than in the female general population, and left-handers had somewhat, but not significantly so, lower 2D:4D as well as better world rankings than right-handers. These findings extend related evidence suggestive of prenatal programming of aptitude across a variety of sports, especially running and soccer. Some known extragenital effects of prenatal testosterone that contribute to the development of efficient cardiovascular systems, good visuospatial abilities, physical endurance and speed, and to the propensity for rough-and-tumble play, apparently promote sporting success in adult life.  相似文献   

The effects of work – rest duration on intermittent exercise and subsequent performance     

Mike Price  Karl Halabi 《Journal of sports sciences》2013,31(8):835-842

This study examined the effects of different work?–?rest durations during 40?min intermittent treadmill exercise and subsequent running performance. Eight males (mean?±?s: age 24.3?±?2.0 years, body mass 79.4?±?7.0?kg, height 1.77?±?0.05?m) undertook intermittent exercise involving repeated sprints at 120% of the speed at which maximal oxygen uptake (v-[Vdot]O_2max) was attained with passive recovery between each one. The work?–?rest ratio was constant at 1:1.5 with trials involving short (6:9?s), medium (12:18?s) or long (24:36?s) work?–?rest durations. Each trial was followed by a performance run to volitional exhaustion at 150% v-[Vdot]O_2max. After 40?min, mean exercise intensity was greater during the long (68.4?±?9.3%) than the short work?–?rest trial (54.9?±?8.1% [Vdot]O_2max; P?<?0.05). Blood lactate concentration at 10?min was higher in the long and medium than in the short work?–?rest trial (6.1?±?0.8, 5.2?±?0.9, 4.5?±?1.3?mmol?·?l^?1, respectively; P?<?0.05). The respiratory exchange ratio was consistently higher during the long than during the medium and short work?–?rest trials (P <?0.05). Plasma glucose concentration was higher in the long and medium than in the short work?–?rest trial after 40?min of exercise (5.6?±?0.1, 6.6?±?0.2 and 5.3?±?0.5?mmol?·?l^?1, respectively; P?<?0.05). No differences were observed between trials for performance time (72.7?±?14.9, 63.2?±?13.2, 57.6?±?13.5?s for the short, medium and long work?–?rest trial, respectively; P = 0.17), although a relationship between performance time and 40?min plasma glucose was observed (P?<?0.05). The results show that 40?min of intermittent exercise involving long and medium work?–?rest durations elicits greater physiological strain and carbohydrate utilization than the same amount of intermittent exercise undertaken with a short work?–?rest duration.  相似文献   

Digit ratio (2D:4D) and performance in elite rugby players     

M. Bennett  J. T. Manning  C. J. Cook 《Journal of sports sciences》2013,31(13):1415-1421

Abstract

The relative length of the second and fourth digits (2D:4D) is a putative marker for prenatal testosterone. Low 2D:4D has been reported to correlate with high performance in sport in general. Here, for the first time, we examine the relationship between 2D:4D and performance in elite rugby players. The 44 players (28 forwards, 16 backs) were drawn from the Ospreys Rugby Union Club and 44 age-matched controls. The measures of performance comprised age-adjusted number of international performances (caps) for Wales, a comparison of coaches' first-choice League team with others, and the number of tries scored by backs in club matches. Compared with controls, players were larger and had lower 2D:4D for the right and left hand. With regard to number of caps, players with low 2D:4D in their right hand and low right 2D:4D compared with their left (right ? left 2D:4D difference) had high numbers of caps. First-choice players did not differ significantly from second-choice players in their 2D:4D but they did have a lower right ? left 2D:4D difference than second-choice players. Low right 2D:4D and low right ? left 2D:4D difference were significantly linked with large numbers of tries. We conclude that low right 2D:4D and low right ? left 2D:4D difference are predictors of high rugby performance.  相似文献   

Salivary and plasma cortisol and testosterone responses to interval and tempo runs and a bodyweight-only circuit session in endurance-trained men     

Amy Vivien Tanner  Birthe Vejby Nielsen  Judith Allgrove 《Journal of sports sciences》2013,31(7):680-689

Abstract

The aim of this study was to examine the acute response to plasma and salivary cortisol and testosterone to three training protocols. Ten trained endurance athletes participated in three experimental trials, such as interval training (INT), tempo run (TEMP) and bodyweight-only circuit training (CIR), on separate days. Blood and saliva samples were collected pre- and 0, 15, 30 and 60 min post-exercise. Peak post-exercise salivary cortisol was higher than pre-exercise in all trials (P < 0.01). After INT, salivary cortisol remained elevated above pre-exercise than 60 min post-exercise. Salivary testosterone also increased post-exercise in all trials (P < 0.05). Plasma and salivary cortisol were correlated between individuals (r = 0.81, 0.73–0.88) and within individuals (r = 0.81, 0.73–0.87) (P < 0.01). Plasma and salivary testosterone was also correlated between (r = 0.57, 0.43–0.69) and within individuals (r = 0.60, 0.45–0.72), (P < 0.01). Peak cortisol and testosterone levels occurred simultaneously in plasma and saliva, but timing of post-exercise hormone peaks differed between trials and individuals. Further investigation is required to identify the mechanisms eliciting an increase in hormones in response to CIR. Furthermore, saliva is a valid alternative sampling technique for measurement of cortisol, although the complex, individual and situation dependent nature of the hormone response to acute exercise should be considered.  相似文献   

Effect of tapering period on plasma hormone concentrations,mood state,and performance of elite male cyclists     

《European Journal of Sport Science》2013,13(3):183-190

Abstract

In this study, we investigated the effect of 1- and 3-week tapering periods on concentrations of plasma testosterone (T), cortisol (C), T/C ratio, mood state, and performance in elite male cyclists. After 8 weeks of progressive training, cyclists were randomly assigned to a control group (n=12) who continued performing intense training for a further 3 weeks, or a taper group (n=12) who continued with a 50% reduction in training volume. Blood testosterone and cortisol concentrations were assayed and the T/C ratio calculated from analysis obtained via standard ELISA. Mood state was determined using the Profile of Mood States (POMS) questionnaire. All data were collected immediately after a 40-km time-trial performed before, during, and after the 8-week training protocol and after the 1- and 3-week tapering/training periods. In the taper group, 40-km time-trial time decreased significantly (P<0.01) and equally for both the 1- and 3-week taper periods relative to the control group. There were significant elevations in T/C ratio (P<0.001) and reductions in cortisol concentrations and POMS scores in the taper group relative to the control groups at the end of both the 1- and 3-week tapering periods. Hence, taper periods are effective in improving performance and mood state and elevating the blood T/C ratio.  相似文献