温度和盐度对青蛤耗氧率和排氨率的影响   总被引：9，自引：0，他引：9  

金春华 《丽水学院学报》2005,27(2):46-51

研究了温度(15℃～32℃)、盐度(5～28)对青蛤的耗氧率和氨-N排泄率的影响。实验在青蛤饥饿24h后的封闭水体中进行,试验水中的溶氧浓度和氨-N浓度采用仪器测定。实验结果表明,在温度为15℃～28℃范围内,青蛤的耗氧率和排氨率随温度的升高而升高,排氨率尤其明显。在盐度为5～20的范围内,青蛤的耗氧率和排氨率随着盐度的升高而升高。当水温高于28℃时,青蛤的耗氧率明显下降,氨-N排泄率却迅速增加;当盐度大于20时,其耗氧率明显下降,而氨-N排泄率变化幅度不大。随青蛤个体的变小,其O:N的比值有逐渐变大的趋势。当盐度在5～20时,3种规格青蛤的O:N随盐度的升高而逐步增大,在20时达到最大值,然后其值开始变小。当温度在15～28℃时,3种规格青蛤的O:N随温度的升高而逐步增大,在28℃时达到最大值,然后其值开始变小。  相似文献   

时域数字脉冲压缩及其实现系统     

纪平 《合肥联合大学学报》2002,12(1):100-104

本分析了时域脉冲压缩原理及数字式脉冲压缩方法，介绍了一种专用型FIR芯片构成的数字式脉冲压缩器，并给出了试验结果。  相似文献   

The exercise intensity at maximal oxygen uptake (i⩒O2max): Methodological issues and repeatability     

Kevin L. Merry  Mark Glaister  Glyn Howatson  Ken Van Someren 《European Journal of Sport Science》2016,16(8):989-995

The minimum exercise intensity that elicits ?O_2max (i?O_2max) is an important variable associated with endurance exercise performance. i?O_2max is usually determined during a maximal incremental exercise test; however, the magnitude and duration of the increments used influence the i?O_2max value produced by a given test. The aims of this study were twofold. The first was to investigate whether the i?O_2max value produced by a single cycle ergometer test (i?O_2max(S)) was repeatable. The second was to determine if i?O_2max(S) represents the minimum intensity at which ?O_2max is elicited when compared to a refined i?O_2max value (i?O_2max(R)) derived from repeated tests. Seventeen male cyclists (age 33.9?±?7.7 years, body mass 80.9?±?10.2?kg, height 1.82?±?0.05?m; VO_2max 4.27?±?0.62 L?min^?1) performed four maximal incremental tests for the determination of i?O_2max(S) and i?O_2max(R) (3 min stages; 20?W increments). Trials 1 and 2 were identical and used for assessing the repeatability of i?O_2max(S), trials 3 and 4 began at different intensities and were used to determine i?O_2max(R). i?O_2max(S) showed good test–retest repeatability for i?O_2max (CV?=?4.1%; ICC?=?0.93), VO_2max (CV?=?6.3%; ICC?=?0.88) and test duration (CV?=?6.7%; ICC?=?0.89). There was no significant difference between i?O_2max(S) and i?O_2max(R) (303?±?40?W vs. 301?±?42?W) (P?2max determined directly during a maximal incremental test is repeatable and provides a very good estimate of the minimum exercise intensity that elicits ?O_2max.  相似文献   

10W集成开关电源的制作     

许陵 《Journal of Zhangzhou Technical Institute》2006,8(4):37-39,60

Topwith—Ⅱ是一种PWM／MOSFET二合一的新型集成芯片，采用它制作高频开关电源，不仅简化了电路，同时可以改善电源的电磁兼容性能，降低制作成本，本文介绍一种用TOP223Y制作的稳压电源。  相似文献   

对量子噪声实虚部互关联情况下饱和激光模型光强涨落的分析     

李跃宏 《云南电大学报》2007,9(3):90-93

针对实、虚部关联的量子噪声及泵噪声驱动的饱和激光模型,基于近似福克—普郎克方程,推导激光强度定态概率分布函数,利用投影算子法,分析了由于量子噪声实虚部关联度λq导致锁相时的光强度关联函数C(τ)和集中驰豫时间Tc。通过计算机数据计算及作图,得到了定态情况下光强概率分布函数图形,讨论了量子噪声实、虚部的互关联对光强关联函数和集中驰豫时间的影响。结果表明:量子噪声实、虚部互关联会导致激光强度涨落增大。  相似文献   

用遥控器操作单片机     

黄光桂  邹书文 《中山大学学报论丛》1994,(4)

本文介绍红外线遥控器操作单片机8031的红外信号接收器的连结电路，阐述遥控指令信号的软件和从软件硬件上排除干扰信号的原理、方法，并给出相应的程序．  相似文献   

Letter to the editor     

Martin Mooses  Kerli Mooses  Diresibachew W. Haile  Jérôme Durussel  Priit Kaasik  Yannis P. Pitsiladis 《Journal of sports sciences》2016,34(1):99-100

Santos-Concejero and Tucker argued in their letter to the editor that in our study the running economy in achieving superior performance was overlooked due to some methodological aspects. Having given the remarks of Santos-Concejero and Tucker appropriate consideration, in this letter to the editor, we argue that our paper does not downplay the influence of running economy on the determinants of the East African running phenomenon, but rather adds novel insights into the interaction between running economy, maximal oxygen uptake and performance.  相似文献   

Similar results for face mask versus mouthpiece during incremental exercise to exhaustion     

Dale R. Wagner  Nicolas W. Clark 《Journal of sports sciences》2016,34(9):852-855

Investigations in the 1990s evaluated the influence of breathing assemblies on respiratory variables at rest and during exercise; however, research on new models of breathing assemblies is lacking. This study compared metabolic gas analysis data from a mouthpiece with a noseclip (MOUTH) and a face mask (MASK). Volunteers (7 males, 7 females; 25.1 ± 2.7 years) completed two maximal treadmill tests within 1 week, one MOUTH and one MASK, in random order. The difference in maximal oxygen consumption (VO_2max) between MOUTH (52.7 ± 11.3 ml · kg^?1 · min^?1) and MASK (52.2 ± 11.7 ml · kg^?1 · min^?1) was not significant (P = 0.53). Likewise, the mean MOUTH–MASK differences in minute ventilation (V_E), fraction of expired oxygen (FEO₂) and carbon dioxide (FECO₂), respiration rate (RR), tidal volume (V_t), heart rate (HR), and rating of perceived exertion (RPE) at maximal and submaximal intensities were not significant (P > 0.05). Furthermore, there was no systematic bias in the error scores (r = ?0.13, P = 0.66), and 12 of the 14 participants had a VO_2max difference of ≤3 ml · kg^?1 · min^?1 between conditions. Finally, there was no clear participant preference for using the MOUTH or MASK. Selection of MOUTH or MASK will not affect the participant’s gas exchange or breathing patterns.  相似文献   

脉冲电流测量装置设计     

田库  李小鹏  刘玉敏 《天津工程师范学院学报》2007,17(3):36-38

为准确测量重接式电磁发射装置中的脉冲大电流,设计了一个Rogowski线圈,阐明了其设计原理,分析了电流变化对Rogowski线圈本身参数(电阻、电感)的影响,并针对重接式电磁发射线圈电流的特殊性,采用了适当的外部接线方式。最后,采用此系统测量了重接式电磁发射装置中的电流,取得了令人满意的效果。  相似文献   

推测青少年拳击运动员最大摄氧量指标的三元回归方程分析     

马维民 《伊犁师范学院学报》2004,(3):78-80

对青少年拳击运动员的体重、肺活量、台阶指数三项指标对最大摄氧量指标的影响作了三元回归方程分析，其结果对运动员选材有重要的参考价值。  相似文献