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双侧吸气射流增氧机内吸气作用的分析 被引量:10
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作者 周建来 邱白晶 郑铭 《农业工程学报》 EI CAS CSCD 北大核心 2009年第7期72-78,共7页
为提高射流增氧机的吸气效率,在其射流器喷嘴内增设吸气管以增加一次吸气。利用流体分析软件,结合试验现象,对内吸气部位的流场进行了CFD三维仿真及分析,从压力分布、流体流速与流动方向两方面,计算分析喷嘴及内吸气管内部的液、气两相... 为提高射流增氧机的吸气效率,在其射流器喷嘴内增设吸气管以增加一次吸气。利用流体分析软件,结合试验现象,对内吸气部位的流场进行了CFD三维仿真及分析,从压力分布、流体流速与流动方向两方面,计算分析喷嘴及内吸气管内部的液、气两相流体运动规律,以判断喷嘴内能够形成吸气的条件及吸气状况。结果证明当位置系数在一定范围内变化时,内吸气管确实发挥了吸气作用,当内吸气管轴向位置系数R=0,射流器喷嘴内吸气作用达到最佳效果,而当R=1时,射流器喷嘴内吸气作用最差。此外,对不能形成吸气的情况进行了对比研究。 展开更多
关键词 养殖机械 流场 增氧机 射流器 内吸气 仿真
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Respiratory Risk Associated with Indoor Air Pollutants in the Form of Settled House Dust
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作者 Herbert Jackson III 《Journal of Environmental Science and Engineering(B)》 2017年第5期231-293,共63页
Asthma and allergies are considered by many physicians as being triggered by different substances in the air that people breathe. The lung is the most common site of injury by airborne pollutants. Acute effects, howev... Asthma and allergies are considered by many physicians as being triggered by different substances in the air that people breathe. The lung is the most common site of injury by airborne pollutants. Acute effects, however, may also include non-respiratory signs and symptoms, which may depend upon toxicological characteristics of the substances and host-related factors. The studying of indoor air quality can provide a method for appropriate remedial action. Research suggests that SHD (Settled House Dust) may be a significant source for indoor exposure to different substances. This research study consisted of sampling dust from homes in different area codes. The dust samples were collected from August 2006 thru March 2007 and analyzed using GC/MS (Gas Chromatography/Mass Spectrometry). The purpose of this research study will display how sampling household dust is a powerful tool for identifying chemicals that contribute to poor indoor air quality. 展开更多
关键词 SHD (Settled House Dust) asthma and allergies phthalates.
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死腔内气体吸出技术对急性高碳酸血症犬呼吸功能及血流动力学的影响 被引量:4
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作者 赵卫国 刘又宁 +2 位作者 曹德森 陈良安 张歆刚 《中华结核和呼吸杂志》 CAS CSCD 北大核心 2001年第11期643-646,共4页
目的 建立死腔内气体吸出技术 (ASPIDS)的方法 ,并探讨ASPIDS对急性高碳酸血症(HC)杂种犬二氧化碳清除的效果及其对通气效率的改善作用。方法 将 12只杂种犬分为常规机械通气 (CMV)组和高碳酸血症 (HC)组 ,每组 6只。用自行设计的ASP... 目的 建立死腔内气体吸出技术 (ASPIDS)的方法 ,并探讨ASPIDS对急性高碳酸血症(HC)杂种犬二氧化碳清除的效果及其对通气效率的改善作用。方法 将 12只杂种犬分为常规机械通气 (CMV)组和高碳酸血症 (HC)组 ,每组 6只。用自行设计的ASPIDS装置对两组动物行气管内吹气(TGI)和ASPIDS ,分别观察两组动物在TGI(吹气流量 4 0L min)和ASPIDS(抽气流量 4 0L min)时呼气末二氧化碳分压 (PetCO2 )、血气、呼吸力学、血流动力学等指标的变化。结果  (1)ASPIDS可明显降低两组动物的动脉血二氧化碳分压 (PaCO2 )水平 (P <0 0 0 0 1) ,并能在潮气量 (VT)降低 30 %的情况下维持PaCO2 在正常范围 ,ASPIDS对二氧化碳的清除效果优于TGI;(2 )ASPIDS使两组动物的气道压力明显降低 (P <0 0 0 0 1) ;(3)ASPIDS使PetCO2 和呼气阻力 (Re)显著降低 ,而对肺顺应性 (Cst)无明显影响(P >0 0 5 ) ;(4 )ASPIDS对血流动力学和氧动力学指标无显著影响 (P >0 0 5 )。结论 ASPIDS是一种简便实用的机械通气的辅助手段 ,较TGI更能有效地降低PaCO2 。 展开更多
关键词 死腔内气体吸出 气管内吸气 高碳酸血症 机械通气 呼吸功能 血流动力学
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Efficacy of continuous tracheal gas insufflation in spontaneously breathing canine with acute lung injury 被引量:1
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作者 詹庆元 王辰 +2 位作者 商宇鸣 童朝辉 翁心植 《Chinese Medical Journal》 SCIE CAS CSCD 2001年第6期98-100,111,共4页
Objective To investigate the effects of continuous tracheal gas insufflation (CTGI) combined with biphasic intermittent positive airway pressure (BIPAP) ventilation on dogs with spontaneous breathing. Methods Eight ... Objective To investigate the effects of continuous tracheal gas insufflation (CTGI) combined with biphasic intermittent positive airway pressure (BIPAP) ventilation on dogs with spontaneous breathing. Methods Eight canine models with oleic acid induced lung injury and spontaneous breathing were ventilated in a random order by Evita 2 (Drager Inc., Germany) in modes of BIPAP (BIPAP group) and BIPAP with CTGI flow rate of 3, 6 and 9?L/min (T3, T6 and T9 groups), respectively. The setting parameters of BIPAP were fiction of inspired oxygen 60%, inspiratory to expiratory ratio 1∶1, respiratory rate 20 and positive end expiratory pressure 5?cm?H2O. Arterial and mixed venous blood gas, lung mechanics, systemic and pulmonary hemodynamics status were monitored at the same level of PaCO2 obtained by adjusting peak inspiratory pressure of BIPAP. Results Peak inspiratory pressure in the T6 group (14±4?cm?H2O) and in the T9 group (11±3?cm?H2O) were significantly lower than that of BIPAP (20±5?cm?H2O, P<0.01), but there was no significant difference among the T3, T6 and T9 groups or between the T3 and BIPAP groups. PaO2, mean artery blood pressure, mean pulmonary artery pressure, pulmonary artery wedge pressure, cardiac ouput, oxygen delivery and oxygen consumption all remained unchanged in four different conditions.Conclusions Using BIPAP combined with CTGI does not cause asynchrony between ventilator and spontaneous breathing, but significantly decreases airway pressure with no influence on hemodynamics and oxygenation. Therefore, BIPAP with CTGI may be a useful support technique, especially in cases where the airway pressure should be limited. 展开更多
关键词 mechanical ventilation · tracheal gas insufflation · acute lung injury · spontaneous breathing
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Effects of extrinsic positive end-expiratory pressure on work of breathing in patients with chronic obstructive pulmonary disease
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作者 孔维民 王辰 +2 位作者 杨媛华 黄克武 姜超美 《Chinese Medical Journal》 SCIE CAS CSCD 2001年第8期8-11,101,共5页
Objective To investigate the effects of extrinsic positive end-expiratory pressure (PEEPe) on work of breathing in patients with chronic obstructive pulmonary disease (COPD) and their corresponding mechanism.Methods... Objective To investigate the effects of extrinsic positive end-expiratory pressure (PEEPe) on work of breathing in patients with chronic obstructive pulmonary disease (COPD) and their corresponding mechanism.Methods Ten ventilated patients with COPD were included in the study. A Bicore CP-100 pulmonary monitor (Bicore Monitoring System, USA) was used for monitoring respiratory mechanics. First, dynamic intrinsic positive end-expiratory pressure (PEEPi,dyn) was measured when PEEPe was zero, which was called PEEPi,dynz. Then the PEEPe was set randomly at 0%, 40%, 60%, 80% and 100% of PEEPi,dynz respectively. Pulmonary mechanics and other parameters (heart rate, blood pressure and blood gas analysis) were measured 30 minutes after the level of PEEPe was changed.Results Work of breathing patient (WOBp), pressure time product, difference of esophageal pressure and PEEPi,dyn decreased significantly when PEEPe was applied, and continued decreasing as PEEPe was increased. Work of breathing ventilator increased significantly when PEEPe was increased to 80% and 100% of PEEPi,dynz. Significantly positive linear correlation was found between the changes in WOBp and in PEEPi,dyn.Conclusions WOBp decreases gradually as PEEPe is increased. WOBp decreases by narrowing the difference between the alveolus pressure and the central airway pressure at the end of expiration when PEEPe is applied. 展开更多
关键词 obstructive pulmonary disease · mechanical vent ilation · extrinsic positive end expiratory pressure work of bre athing
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Gas Absorption by Wavy Falling Liquid Film Formed on Inner Surface of Vertical lubes
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作者 Akio Miyara Tomoki Yamamoto +1 位作者 Toru Iemura Takashi Shimada 《Journal of Thermal Science》 SCIE EI CAS CSCD 2003年第1期57-61,共5页
An experimental study on gas absorption into falling liquid film formed on inner surface of vertical tubes has been carried out in order to clarify fundamental characteristics of the gas absorption and enhancement by ... An experimental study on gas absorption into falling liquid film formed on inner surface of vertical tubes has been carried out in order to clarify fundamental characteristics of the gas absorption and enhancement by surface waves. The water supplied into the test tubes is periodically disturbed by fluctuating a silicon tube before the test section with a speaker and the wavy films absorb the oxygen filled in the tubes. Imposing the periodic disturbance enhances the gas absorption and the enhancement has a maximum at around 20-30 Hz, where the gas absorption is 20-30% higher. Mass transfer coefficients obtained with five tubes agree well with those obtained with single tube. Two-dimensional numerical simulations have also been conducted for gas absorption by wavy film and the enhancement mechanism of the gas absorption is discussed. 展开更多
关键词 falling liquid film gas absorption surface wave vertical tube mass transfer enhancement.
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