膜技术在青海盐湖集团综合利用项目二期工程空分装置中的应用     

赵彪  李强  崔永刚  张波  王峰 《中国科技纵横》2010,(15):405-405,384

把膜分离技术用于空气分离是近年来发展很快的一种新型技术。在化工生产中有着广泛的应用。青海盐湖集团化工公司二期空分项目部以提高空分产品的经济效益为目的,采用膜分离技术提高氧、氮气及液氩产品的纯度,增强该项目产品的回收率。  相似文献   

铁路隧道TGP超前地质预报系统应用探讨     

黄建华  赵玉龙 《福建工程学院学报》2014,(3):205-210

通过京福铁路客运专线闽赣IV隧道工程实例,阐述了TGP地震反射波法的基本原理和过程,并分析其特点和优越性。通过工程应用研究,对TGP206系统的工作原理、数据处理、解释技术和等级分析等进行系统探讨,剖析了TGP系统进行隧道围岩类别判识及其有效性等相关问题,验证了预报结果的准确性。  相似文献   

中引式气力输送系统的特性研究     

吴晓 《常熟理工学院学报》2009,23(10):84-88

中引式气力输送系统具有独立、串联和远近距离均适应的优点．通过实验研究,探讨了中引式气力输送系统的流动模式、管道阻力特性和输送压力频谱特性等．实验结果表明,中引式气力输送随着操作气速的变化,管内灰栓的流动模式也相应发生变化,分别为：柱塞流、栓流和悬浮流;柱塞流压力频谱较小,灰栓、气栓相间的多栓流属基本稳定流动;栓流压力频谱振幅最大,易成为独栓,属不稳定流动,输送量与柱塞流相当;悬浮流压力频谱最低,属稳定流动,输送量最低,输送速度最快,管道易磨损．柱塞流、栓流及悬浮流模式,对于给定物料操作气速与输送平均压力之间随着操作气速增加,输送压力逐渐下降．  相似文献   

交流变频调速技术节能应用分析   总被引：1，自引：0，他引：1  

俞文英 《洛阳师范学院学报》2009,28(5):54-55

介绍了交流变频调速类型、基本原理和节能原理及分析,并在有关行业生产过程中,采用变频调速技术,实现节能、改善工艺、提高了产品质量,并阐述了变频调速技术(或装置)存在的优点,以及发展趋势.  相似文献   

狭义相对论速度与加速度变换   总被引：1，自引：0，他引：1  

文军 《渭南师范学院学报》2009,24(5):17-20

文中给出了相对论速度变换与四维速度变换、加速度变换与四维加速度变换的联系.  相似文献   

音叉的速度共振与位移共振曲线的测量和研究     

倪敏  薛珍美 《实验室研究与探索》2010,29(2)

利用接收线圈和压电换能片2种传感器测得音叉受迫振动的速度、位移共振曲线,通过实验比较和理论分析,证明这2种传感器所测得的物理量并不相同,同时分析和验证了2种幅频曲线的区别。对影响位移共振曲线测量结果的阻尼系数进行讨论和分析,得出:用接收线圈做传感器测得的音叉共振曲线为速度共振曲线,而用压电换能片做传感器测得的音叉共振曲线为位移共振曲线。实验的研究有利于学生对受迫振动和共振概念的深入理解,也有利于对2种传感器的正确运用。  相似文献   

马兰籽油中脂肪酸的GC—MS分析     

姜显光  侯冬岩  回瑞华  李铁纯  刘晓媛  李秀铭 《鞍山师范学院学报》2010,12(2):17-19

采用索氏提取法对马兰籽中马兰籽油进行了提取,进行甲酯化处理后,以气相色谱．质谱联用仪进行了分析．结果表明：马兰籽油中共鉴定出16种脂肪酸,占马兰籽油总量的98．66％,在马兰籽油中鉴定出的脂肪酸主要为十八碳二烯酸、十八碳烯酸、十六酸．  相似文献   

Comparison of two methodological approaches for the mechanical analysis of single-joint isoinertial movement using a customised isokinetic dynamometer*     

Mathieu Plautard  Gaël Guilhem  Vincent Fohanno  Antoine Nordez  Christophe Cornu 《Sports biomechanics / International Society of Biomechanics in Sports》2018,17(3):287-302

Compared to isokinetic and isometric tests, isoinertial movements have been poorly used to assess single-joint performance. Two calculation procedures were developed to estimate mechanical performance during single-joint isoinertial movements performed on a customised isokinetic dynamometer. The results were also compared to appreciate the effects of measurement systems and calculation procedures. Five participants performed maximal knee extensions at four levels of resistance (30, 50, 70 and 90% of the one-repetition maximum, 1-RM). Joint angular velocity and torque were assessed from customised isokinetic dynamometer measures (method A) and from weight stack kinematic (method B). Bland–Altman plots and mean percent differences (M_diff) were used to assess the level of agreement for mean and peak angular velocity and torque. A Passing–Bablok regression was performed to compare the angular velocity-angle and torque-angle relationships computed from the two analysis methods. The results showed a high level of agreement for all mechanical parameters (M_diff < 6% for all parameters). No statistically significant differences were observed between methods A and B in terms of angular velocity-angle and torque-angle relationships except at 30% of 1-RM for the torque-angle relationship. Both methodologies provide comparable values of angular velocity and torque, offering alternative approaches to assess neuromuscular function from single-joint isoinertial movements.  相似文献   

Reliability of power and velocity variables collected during the traditional and ballistic bench press exercise     

Amador García-Ramos  G. Gregory Haff  Paulino Padial  Belén Feriche 《Sports biomechanics / International Society of Biomechanics in Sports》2018,17(1):117-130

This study aimed to examine the reliability of different power and velocity variables during the Smith machine bench press (BP) and bench press throw (BPT) exercises. Twenty-two healthy men conducted four testing sessions after a preliminary BP one-repetition maximum (1RM) test. In a counterbalanced order, participants performed two sessions of BP in one week and two sessions of BPT in another week. Mean propulsive power, peak power, mean propulsive velocity, and peak velocity at each tenth percentile (20–70% of 1RM) were recorded by a linear transducer. The within-participants coefficient of variation (CV) was higher for the load–power relationship compared to the load–velocity relationship in both the BP (5.3% vs. 4.1%; CV ratio = 1.29) and BPT (4.7% vs. 3.4%; CV ratio = 1.38). Mean propulsive variables showed lower reliability than peak variables in both the BP (5.4% vs. 4.0%, CV ratio = 1.35) and BPT (4.8% vs. 3.3%, CV ratio = 1.45). All variables were deemed reliable, with the peak velocity demonstrating the lowest within-participants CV. Based upon these findings, the peak velocity should be chosen for the accurate assessment of BP and BPT performance.  相似文献   

The effect of altering loading distance on skeleton start performance: Is higher pre-load velocity always beneficial?     

Steffi L. Colyer  Keith A. Stokes  James L. J. Bilzon  Danny Holdcroft 《Journal of sports sciences》2018,36(17):1930-1936

Athletes initiating skeleton runs differ in the number of steps taken before loading the sled. We aimed to understand how experimentally modifying loading distance influenced sled velocity and overall start performance. Ten athletes (five elite, five talent; 67% of all national athletes) underwent two to four sessions, consisting of two dry-land push-starts in each of three conditions (preferred, long and short loading distances). A magnet encoder on the sled wheel provided velocity profiles and the overall performance measure (sled acceleration index). Longer pre-load distances (12% average increase from preferred to long distances) were related to higher pre-load velocity (r = 0.94), but lower load effectiveness (r = ?0.75; average reduction 29%). Performance evaluations across conditions revealed that elite athletes’ preferred distance push-starts were typically superior to the other conditions. Short loading distances were generally detrimental, whereas pushing the sled further improved some talent-squad athletes’ performance. Thus, an important trade-off between generating high pre-load velocity and loading effectively was revealed, which coaches should consider when encouraging athletes to load later. This novel intervention study conducted within a real-world training setting has demonstrated the scope to enhance push-start performance by altering loading distance, particularly in developing athletes with less extensive training experience.  相似文献