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1.
梯形导向浮阀塔板具有良好的流体力学和传质性能。本文探讨了该塔板的流体力学模型,得出梯形导向浮阀塔板的阀孔临界气速,塔板压降,雾沫夹带和泄漏点孔速的关联式,可代价 梯形导向浮阀塔板设计之用。  相似文献   

2.
应用空气-水系统,在1600mm×400mm的矩形塔内,对梯形导向浮阀塔板的流体力学进行了实验研究,测定了阀孔临界气速,塔板压降,雾沫夹带和泄漏。应用空气-水-CO2系统,测定了梯形导向浮阀塔板的效率。实验结果表明,梯形导向浮阀塔板具有良好的流体力学和传质性能。  相似文献   

3.
对高开孔率、大孔径筛板复合塔板在喷射状态下的流体力学性能进行了测定及关联,提供了必要的流体力学参数。结果表明,该塔板具有阻力低、雾沫夹带量小、操作上限速度大等特点,特别适合那些要求气相负荷大、液相负荷低的过程。  相似文献   

4.
在大型冷模试验装置上,研究了液流强度、外堰高、降液管下口高和堰径比等因素对大型塔板板面液体流动状况的影响。实验表明:大型塔板上液体存在严重的不均匀流动,堰径比较大时,液体流动的不均匀性有所减弱;液流强度、外堰高和降液管下口高对板面液流分布的状况共同构成影响;在外堰高和降液管下口高一定的情况下,存在一个适合的液流强度,使板面液体回流区面积最小。  相似文献   

5.
在φ2.8m大型冷模塔板上,研究了双溢流扩张流和收缩流两种情况下塔板液体流动状况。考察了液流强度,堰径比,外堰高,降液管下口高等对板面液体流动的影响。实验表明,扩张流塔板存在严重回流和滞流现象,收缩流塔板面液体停留时间有明显差异。  相似文献   

6.
简要的说明了筛板塔的操作性能以及如何布置筛板塔板。对计算筛板塔的各项性能:干板压降、净液高度、雾沫夹带、塔板的效率的某些公式进行了比较,推荐一些比较适当的公式。编制了计算筛板塔流体力学以及塔板设计参数、塔板效率的软件‘SieveTray’,对特定的条件进行演练以说明其用法。  相似文献   

7.
对一种穿流式固阀塔板进行了流体力学冷态实验考察。采用常温、常压下的空气和水作为实验介质,测试了不同操作条件下塔板的干板压降、全板压降和清液层高度,比较了不同的塔板结构参数对流体力学性能参数的影响。实验结果表明,塔板压降和清液层高度均随着孔中心距和开孔率的减小而增大,而随着孔径的增大而增大。气液两相在穿流塔板上为逆流流动,且随着气液流量的变化呈现出4种不同的流动形态。建立了清液层高度的经验式,且计算值与实验测量值吻合良好。推导了描述穿流塔板独特的流动形态的参数即气体流通分率的数学表达式,计算结果表明,该分率随着孔中心距的减小而减小,并随着孔径和开孔率的增大而减小。  相似文献   

8.
在500mm×300mm的矩形有机玻璃实验塔中,用水-空气体系对组合式角钢塔板的流体力学性能及传质性能进行实验研究,并以筛孔塔板作对比实验。结果表明组合式角钢塔板是一种结构简单,压降低,压降低,操作弹性宽,处理能力大和板效率较高的新型塔板。  相似文献   

9.
利用双头电导探针测定了固阀塔板上密集鼓泡区气泡的运动速度,考察了密集鼓泡区不同轴向高度的气泡速度分布规律及其分形特征,分析了塔板上密集鼓泡区的气泡运动行为。研究结果表明:不同轴向高度处气泡速度沿同方向的分布具有相似性,近塔中心区域气泡速度变化平缓,呈弱双峰分布;塔板上气泡速度分布具有分形特征,分形维数为1.04~1.25,且随轴向高度的增加均先减小后增大;深层鼓泡区内气泡速度分布的分形维数可以较好地表征气泡运动的湍动强度,两者之间存在线性关系,气泡流湍动强度及分形维数与泡沫层高度间存在指数函数关系。  相似文献   

10.
定向一喷射式塔板在该塔板上,排列有许多舌形板瓣和横向隔板,后者与气液流接触时,能在隔板表面附近产生附加的两相接触区,塔板的结构如图所示。这种塔板经试验台试验和工业性试验,已成功地投入硅有机化合物生产中使用。它比泡罩式塔板具有以下几个优点:生产能力增加50~100%,制造简单,金属消耗量少,安装容易,当有固相沉淀时易于清洗,在塔停止操作进行检查时,液体可以完全流出。因此可以广泛推广于工业中应用。  相似文献   

11.
Objective: To evaluatel the value of D-dimers in patients with acute aortic dissection (AAD). Methods: This study consisted of 16 patients with AAD and 27 non-AAD patients. Serum D-dimets were measured by Sta-Liatest D-DI immunoturbidimetric assay. Results: D-dimer level was higher (P < 0.001) in patients with AAD(7.91 ± 5.52 μg/ml) than that in non- AAD group(1.57±1.24 μg/ml). D-dimer was positive (>0.4 μg/ml) in all patients with AAD and in 10 control group patients (37%). Among patients with acute AAD, D-dimers tended to be higher in Stanford A than in Stanford B (8.67 ± 4.31 μg/ml vs. 3.24±1.27 μg/ml, P <0.01). D-dimer values tended to be higher in more extended disease(3.84 ± 1.65 μg/ml, 8.57 ± 3.58 μg/ml and 11.87 ± 5.69 μg/ml in thoracic aorta, thoracic and abdominal aorta, thoracic and abdominal aorta and iliacal arteries, respectively, P < 0.05 for both 8.57 ± 3.58 and 11.87 ± 5.69 vs. 3.84 ± 1.65 ). Including the control group into the analysis, we found a sensitivity of 100%, a negative predictive value of 100%, and a specificity of 66% and a positive predictive value of 64% for D-dimer in diagnosis of AAD in our patients with suspected AAD. Conclusion: D-dimer was elevated in patients with AAD. A negative D-dimer test result could be useful in excluding AAD.  相似文献   

12.
Objective: To set up a simple and reliable rat model of combined liver-kidney transplantation. Methods: SD rats served as both donors and recipients. 4℃ sodium lactate Ringer's was infused from portal veins to donated livers,and from abdominal aorta to donated kidneys, respectively. Anastomosis of the portal vein and the inferior vena cava (IVC) inferior to the right kidney between the graft and the recipient was performed by a double cuff method, then the superior hepatic vena cava with suture. A patch of donated renal artery was anastomosed to the recipient abdominal aorta. The urethra and bile duct were reconstructed with a simple inside bracket. Results: Among 65 cases of combined liver-kidney transplantation, the success rate in the late 40 cases was 77.5%. The function of the grafted liver and kidney remained normal. Conclusion: This rat model of combined liver-kidney transplantation can be established in common laboratory conditions with high success rate and meet the needs of renal transplantation experiment.  相似文献   

13.
FOR anesthesiologis s ,treatingpostoperativepainhas alwaysbeen a problem.Althoughopioidshave been provedtobe effective,theirsideeffectscouldnotbeignored.With thedevelopmentofscienceand pharmacology,many drugs with aspectsof satisfactoryanalgesicefficacyand couldbe welltoleratedby patientshave been developed.And lornoxicamisone of them, which isa non-steroidalanti-inflammatorydrug (NSAID ), with analgesic, anti-infl-ammatory,andantipyreticproperties.Itseliminationhalf-time(3 to 5 hours) isle…  相似文献   

14.
Objective To observe blood pressure change with age in salt-sensitive teenagers whose salt sensitivity were determined by repeated testing.Methods Salt sensitivity was determined through intravenous infusion of normal saline combined with volume-depletion by oral diuretic furosemide in 55 teenagers. After five years, salt sensitivity was re-examined and subject blood pressure was followed up. Blood pressure changes in salt-sensitive teenagers were compared to that of non-salt sensitive teenagers over five years.Results After 5 years, the repetition rate of salt sensitivity determined by intravenous saline loading is 92.7%. In teenagers with salt sensitivity on the baseline, both the systolic blood pressure increments and increment rates were much higher than non-salt sensitive teenagers (12.7±12.1 mmHg vs. 2.8±5.2 mmHg, P< 0.01; 12.2%± 12.0% vs. 2.5% ±4.4%, P< 0.001,respectively). There was a similar trend for diastolic blood pressure (8.4 ± 6.4 mmHg vs. 3.7 ± 6.4 mmHg, P = 0.052; 13.2% ±10.6 % vs. 6.8%± 10.1%, P = 0.053, respectively).Conclusions Salt sensitivity determined by intravenous saline loading showed good reproducibility. Blood pressure increments with age were much higher in salt-sensitive teenagers than non-salt sensitive teenagers, especially in terms of systolic blood pressure.  相似文献   

15.
Shock wave lithotripsy (SWL) is a treatment of choice for upper urinary stones. However, this procedure is inappropriate for obese patients because the focus is often unable to reach the target owing to the limited focal distance in shock wave source. Although treating such patients in a blast path may increase the application length of shock wave source, it's difficult to find this path on the lithotripter monitor. For this reason, we invented an adjustable calibration marker in order to set an effective focus in the shock wave hath.  相似文献   

16.
Excess production of reactive oxygen species(ROS)of mitochondrion mediated by hyperglycemia is the common pathogenesis of angiopathic complications of diabetes.TCM holds that the damp from the dysfunction of spleen.kidney and liver is the causative factor of complications of diabetes.This is similar to the mechanism of Ros resulting in angiopathic complications of diabetes.When the angiopathic complications of type II diabetes mellitus(T2DM)are difierentiated as caused by turbid damp in TCM can be explained as ROS.Since the obstruction of pathogenic damp in channels and collaterals is said to be the main pathogenesis,the treating principle should be dissolving the damp to remove the obstruction.  相似文献   

17.
INTRODUCTION Obesity is a complex emergent problem, which can be possibly solved not only by the diet but also by the life style and promotion of a constant physical exercise. 1, 2 No doubt careful attentions must be given to the nutritional condition of obese people, the dietary habits, the somatic build (i.e. distribution of fat mass) and the organic functions linked to formation of the fat mass. All the parameters should be constantly monitored before, during and after a diet treatment. 3, 4, 5  相似文献   

18.
People with dysglycemia are at high risk for atherosclerotic diseases. This study aims at investigating the atherosclerotic vascular damage in dysglycemia and its metabolic origin in Tibetan population.  相似文献   

19.
Objective: To observe the therapeutic effects in acupunture treatment of primary dysmenorrhea combined with spinal Tui Na, and study its mechanism. Methods: Thirty cases of the treatment group were treated by acupuncture combined with spinal Tui Na, and thirty cases in the control group were treated by routine acupuncture. Results: The total effective rate was 93.3% in the treatment group, and 73.3% in the control group, with a significant difference between the two groups (P<0.05). Conclusions: Acupuncture combined with spinal Tui Na has good prospects for treatment of primary dysmenorrhea.  相似文献   

20.
In treating chronic nephropathy,Luo Lingjie,a chief physician,pays attention to regulating the balance between yin and yang,treating infection if present,and removing pathogenic factors.He prescribes gentle drugs and uses carefully strongly warming-tonifying ones,emphasizes the importance of persuading the patient to persist in treatment with medication and nurse one's health for recuperation,and is good at combined use of TCM and western medicine therapy and brings the merits of various therapies into full play,with obvious theraoeutic effects.  相似文献   

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