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基于加速度传感器的自行车运动强度评估研究 被引量:4
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作者 赵月民 陈培友 刘晓翠 《山东体育学院学报》 北大核心 2019年第5期70-76,共7页
研究目的:基于加速度传感器,建立自行车运动强度预测方程,确定4.8 MET和7.2 MET对应的VM轴加速度计数最佳临界值点。研究方法:101名普通大学生(实验组81人,验证组20人)实验过程中同时佩戴K4b2和GT3X(腰部、大腿、脚踝),在功率自行车上... 研究目的:基于加速度传感器,建立自行车运动强度预测方程,确定4.8 MET和7.2 MET对应的VM轴加速度计数最佳临界值点。研究方法:101名普通大学生(实验组81人,验证组20人)实验过程中同时佩戴K4b2和GT3X(腰部、大腿、脚踝),在功率自行车上依次进行不同强度(①较低强度:37%~45%VO2max;②中等强度:46%~63%VO2max;③较大强度:64%~91%VO2max)的骑行。选取逐步回归方法建立运动强度预测模型,采用ROC曲线建立VM轴加速度计数最佳临界点。结果:1)脚踝处GT3X三分轴对MET的解释力最高(R2=0.80),且VM轴加速度计数与MET存在较高的相关关系(r=0.89,P<0.01)。2)方程MET=0.00019007×VM+3.121,R2为0.80,SEE为0.61,SEE/Y(%)为10.33%。3)经验证组数据回代检验,各强度水平下方程预测值与K4b2实测值相关系数在0.80~0.85之间(P<0.01);相对误差为8.69%~9.61%;95%的残差基本均落在Bland-Altman散点图Mean±1.96 SD的区间内。4)4.8 MET和7.2MET对应的VM轴加速度计数最佳临界值点分别为9764 counts/min和21138 counts/min。结论:脚踝处是自行车运动GT3X的最佳适配位置,新建方程能够有效地预测运动强度MET,预测准确度较高,所建切点能有效地区分运动强度,可为自行车运动科学监测提供参考。 展开更多
关键词 三轴加速度传感器 自行车运动 运动强度 MET
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基于加速度传感器的大学生自行车运动能耗预测模型研究 被引量:4
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作者 赵月民 陈培友 《山东体育学院学报》 北大核心 2019年第1期80-85,共6页
目的:基于三轴加速度传感器,建立大学生自行车运动能量消耗预测方程。方法:选取101名在校大学生,按性别、年龄分成实验组(81人)和验证组(20人)。实验过程中受试者同时佩戴K4b^2气体代谢分析仪和GT3X加速度传感器(脚踝处),在功率自行车... 目的:基于三轴加速度传感器,建立大学生自行车运动能量消耗预测方程。方法:选取101名在校大学生,按性别、年龄分成实验组(81人)和验证组(20人)。实验过程中受试者同时佩戴K4b^2气体代谢分析仪和GT3X加速度传感器(脚踝处),在功率自行车上依次进行不同强度(较低强度:37%~45%VO_2max;中等强度:46%~63%VO_2max;较大强度:64%~91%VO_2max)的骑行。采用逐步回归方法建立运动能量消耗预测模型。结果:1)ACz轴和VM轴的counts值与能量消耗存在较高的相关关系(P<0.01)。2)运动能量消耗(kcal/min)=0.000219×VM+0.065×BW+0.145×SE-2.032[VM为加速度传感器合轴counts值,BW为体重(kg),SE为性别(女=0,男=1)];R^2等于0.88,SEE和SEE/Y(%)分别为0.61和11.55%。3)经验证组数据回代检验,各强度水平下模型预测值与K4b^2实测值相关系数在0.82~0.86之间(P<0.01);绝对误差为0.38~0.61 kcal/min,相对误差为8.37%~10.54%;95%的残差均落在Bland-Altman散点图Mean±1.96SD的区间内。结论:自行车运动中,通过脚踝佩戴处加速度传感器合轴counts值、性别、体重三个变量建立的能量消耗预测方程,能够有效地预测不同强度水平下的运动能量消耗,预测精度较高,可为大学生自行车运动科学监测提供依据。 展开更多
关键词 自行车运动 三轴加速度传感器 能量消耗 预测方程
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Experimental Research on Desulfurization of Fine Coal Using an Enhanced Centrifugal Gravity Separator 被引量:13
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作者 TAO You-jun LUO Zhen-fu +1 位作者 zhao yue-min TAO Daniel 《Journal of China University of Mining and Technology》 EI 2006年第4期399-403,共5页
A desulphurization experimental study under the effects of compounding physical force fields has been described for 〈 0.5 mm fine particles of high sulfur coal. A statistical test using the Box-Behnken Design of expe... A desulphurization experimental study under the effects of compounding physical force fields has been described for 〈 0.5 mm fine particles of high sulfur coal. A statistical test using the Box-Behnken Design of experiments was conducted to evaluate the effects of individual operating variables and their interactions on desulfurization of fine coal using an enhanced centrifugal gravity separator. A model describing the relation between desulphurization efficiency of pyrite sulfur and different operating variables has been designed. The interactions between different factors on the pyrite sulfur desulphurization efficiency have been analysed. The optimal test conditions for desulfarization are extracted from the Design-Expert 6.0 software. Finally, the pointed out. advantage of centrifugal gravity separation for fine coal is pointed out. 展开更多
关键词 fine coal centrifugal force field Falcon separator PYRITE desulfarization efficiency
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Low Density Dry Coal Beneficiation Using an Air Dense Medium Fluidized Bed 被引量:19
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作者 LUO Zhen-fu ZHU Jian-feng +2 位作者 FAN Mao-ming zhao yue-min TAO Xiu-xiang 《Journal of China University of Mining and Technology》 EI 2007年第3期306-309,共4页
For the production of low ash content clean coal, separation at low density is required for some raw coals.Based on analyzing the fluidizing characteristics of magnetic-pearls with a specific size clistribution and fo... For the production of low ash content clean coal, separation at low density is required for some raw coals.Based on analyzing the fluidizing characteristics of magnetic-pearls with a specific size clistribution and formation mechanism of a microbubble fluidized bed, optimal technological and operating parameters suitable for low density coal separation were determined. The experimental results show that an air dense medium fluidized bed with low den-sity can be formed using magnetic pearls as medium solids, which can efficiently beneficiate coal of 6-50 mm size with a probable error Ep value of 0.05 at a separating density of 1.44 g/cm^3. 展开更多
关键词 fluidized bed medium solids BENEFICIATION
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Numerical Study of Collision and Penetration Behavior Between Particles and Screen Plate 被引量:5
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作者 JIAO Hong-guang zhao yue-min WANG Quan-qiang 《Journal of China University of Mining and Technology》 EI 2006年第2期137-140,146,共5页
For a screening process, the collision and penetration phenomena between particles and screen plate is standard behavior and with collision the mechanical energy of the vibrating screen can be transmitted to the feed.... For a screening process, the collision and penetration phenomena between particles and screen plate is standard behavior and with collision the mechanical energy of the vibrating screen can be transmitted to the feed. In order to recognize further the collision process and the law of penetrating motion, with the spring-dashpot-slider contact model of the distinct element method (DEM), a mathematical model which can describe the collision process has been established and a program for simulating the motion of a single particle on the screen plate developed by VC++. NET. To evaluate the handling capacity of the screen that deals with difficult screening material, an instantaneous penetrating coefficient is defined. The moving period of the screen plate is divided into four stages. By analyzing the state of contact collision at each stage, it is pointed out that the collision ranging from 3π/2 to 2π period is the most favorable aperture for penetration of particles, while the collision ranging from π/2 to n period is the most unfavorable. The numerical simulation result further indicates that increasing the amplitude of the screen plate has a much greater effect on the augmentation of instantaneous penetration coefficient than increasing the vibration frequency. 展开更多
关键词 SCREENING numerical simulation particle motion COLLISION
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Metals Recovery from Fine Printed Circuit Boards Using Falcon SB Concentrator 被引量:2
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作者 WEN Xue-feng zhao yue-min +3 位作者 PAN Yan-jun HE Ya-qun SONG Shu-lei WANG Zhuo-ya 《Journal of China University of Mining and Technology》 EI 2005年第4期322-328,共7页
Physical methods show great potential and advantages on comprehensive reutilization of waste printed circuit boards (PCBs) because of lower investment and operation cost, higher efficiency and environment friendliness... Physical methods show great potential and advantages on comprehensive reutilization of waste printed circuit boards (PCBs) because of lower investment and operation cost, higher efficiency and environment friendliness. However, metals contained in fine fraction of PCBs cannot be recovered effectively by conventional equipments such as high tension electrostatic separator or shaking table. In the paper, this conundrum was resolved successfully with the enhanced Falcon SB concentrator. The separation mechanism of Falcon SB concentrator was analyzed and main factors affecting separation efficiency such as magnitude of rotation frequency of bowl, water counter pressure and slurry concentration of feed were studied and interaction of factors above also were investigated using Design-Expert software. Experiment results show that complete liberation degree and great difference of density between metals and nonmetals are suitable to recover metals from -74 μm PCBs using enhanced Falcon SB concentrator and 80.77 % integration efficiency can be achieved when slurry concentration of feed is 40 g/L with the water counter pressure of 0.01 MPa and rotation frequency of 50 Hz. 展开更多
关键词 Falcon concentrator centrifugal separation waste printed circuit boards integration efficiency
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Evaluating the treatment of E-waste──a case study of discarded refrigerators 被引量:1
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作者 DENG Jian-jun WEN Xue-feng zhao yue-min 《Journal of China University of Mining and Technology》 EI 2008年第3期454-458,共5页
Disassembly and recycling of E-waste creates a series of environmental problems. The selection of a technologically reliable, environmentally friendly, economically affordable and socially acceptable recycling technol... Disassembly and recycling of E-waste creates a series of environmental problems. The selection of a technologically reliable, environmentally friendly, economically affordable and socially acceptable recycling technology for E-waste is a significant question. This study establishes a Monte-Carlo mathematical model of cost minimization, given the constraints of environmentally sound handling of the e-waste, in the context of Crystal Ball risk assessment and evaluation software. By following the streams of the different treatment processes, which consist of various technologies including disassembly, recycling and disposal, the econom-ics of various possibilities were identified and the optimal recycling technology proposed. The key factors of the proposed scenarios were determined by using sensitivity analysis. The results of this study show that, for discarded refrigerators, the operating life span plays the key role. The model supports maintenance and resale of the short lived refrigerators. For the longer lived refrigerators material recycling is recommended by the model. Sensitivity analysis shows that purchase cost, plastic sale price, condenser sale price and disassembly costs are the main effects. This study provides a significant technical support for policy making in E-waste management. 展开更多
关键词 E-WASTE end-of-life refrigerator RECYCLING Monte-carlo method sensitivity analysis
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Theoretical study on separation density of gravity beneficiation
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作者 JIAO Hong-guang zhao Xiao-nan zhao yue-min 《Journal of Coal Science & Engineering(China)》 2010年第2期193-197,共5页
Separation density is one of the most concerned operating parameters in gravity beneficiation.Although equal-errors cut point or distribution density is usually used as practical separation density in gravity benefici... Separation density is one of the most concerned operating parameters in gravity beneficiation.Although equal-errors cut point or distribution density is usually used as practical separation density in gravity beneficiation, the gravity separating process complexly affected by many kinds of factors is actually carried out at a fluctuant density; namely, the practical separation density is essentially a random variable.The studied results show that the equal-errors cut point is the mathematical expectation of this random variable, and the distribution density corresponds to the highest separation efficiency in the gravity separation process.This shows that the distribution density is the best working point of the gravity separation equipment under a particular operating condition.Therefore,in order to fully develop the function of the gravity separation equipment, the distribution density should be close to the theoretical separation density unlimitedly in the range of minimum fluctuation. 展开更多
关键词 separation density gravity beneficiation equal-errors cut point distribution density random variable
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Combined Removal of Surface Moisture and Dust from Feed Coal for Coal Dry Cleaning with an Air-solid Fluidized Bed
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作者 YANG Guo-hua zhao yue-min CHEN Qing-ru 《Journal of China University of Mining and Technology》 EI 2005年第4期283-287,共5页
A demonstration plant and a commercial plant employing coal dry cleaning technology with an air-solid fluidized bed were built in China. The operation practice of these two plants shows that the surface moisture and t... A demonstration plant and a commercial plant employing coal dry cleaning technology with an air-solid fluidized bed were built in China. The operation practice of these two plants shows that the surface moisture and the fines or dust of feed coal must be well controlled as low as possible. For this purpose, a new process of combined removal of surface moisture and dust from feed coal using a vibrated fluidized bed dryer was investigated in a batch test apparatus and a pilot test system. A mathematical model on drying kinetics of coal surface moisture was developed and three empirical formulas of the model coefficient involving the main operating variables were determined based on the test results from the batch test apparatus. The mathematical model shows that the surface moisture retained in coal during drying decreases exponentially with drying time. According to this model, a new divisional heat supply mode, in which the inlet gas of higher temperature was introduced into the fore part of the dryer and the inlet gas of lower temperature into the rear part of the dryer, was employed in the pilot test system. The pilot tests show that 1) the new divisional heat supply mode is effective for lowering down the average temperature and reducing the total heat loss of the outlet gas off the dryer, 2) the moist coal of about 60 g/kg surface moisture contentcan be dried to about 10 g/kg, and simultaneously the fines (〈1mm in diameter) adhering to the surface of coarse coal particles are completely washed off by the gas flow. 展开更多
关键词 COAL dry cleaning DRYING DUST vibrated fluidized bed
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