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气流床气化炉的数学模型是气化装置设计和操作优化的基础,气固停留时间分布是影响气流床气化炉出口组成和碳转化率的关键因素。以气固停留时间分布为依据,结合反应动力学建立气流床气化炉的通用网络模型,模拟值与工业值吻合。对于神府煤,考察了氧煤比改变对气化结果的影响,结果表明:最佳氧煤比(氧气体积与煤(干基)质量之比)期望值约为0.655 Nm3/kg,生产中为保证液态排渣,氧煤比应控制在0.663 Nm3/kg左右。该通用网络模型计算速度快,适用于建立气化炉的动态模型。 相似文献
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采用α-萘酚与对氨基苯磺酸重氮盐的偶合竞争串联二级反应体系,在4种型式的两喷嘴对置同轴撞击流反应器内研究了喷嘴中心和环隙射流的动量比、射流速度、喷嘴间距、反应器容积对撞击流反应器内微观混合过程的影响。结果表明:增大喷嘴中心和环隙射流的动量比可改善微观混合状态;在撞击区特征停留时间处于0.03-1.0s的实验范围内存在一最佳特征停留时间tRC,当tR〈tRC时,减少tR并不能有效改善微观混合状况;当 相似文献
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利用Fluent软件对德士古水煤浆气化炉进行数值模拟仿真。用Finite Rate/Eddy-Dissipation(有限速率/涡耗散)模型求解气化过程;用Standard k-ε湍流模型封闭动量方程;用DPM(离散相)模型设置并求解煤粉燃烧的多步焦炭反应;用P-1辐射模型模拟气化炉内辐射特性。通过比较模型预测的数据与工业数据的差别,证实了模型的有效性。在此模型基础上考察了煤浆流量、氧气流量和煤浆浓度三者之间的耦合关系和中心氧体积分数对出口气体组成、有效气产率、温度及碳转化率的影响规律,为提高煤气有效成分、碳转化率和保证生产安全提供参考依据。 相似文献
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在小型单管气化反应炉内进行了本题的研究。用粉煤和变换剂制成的型煤进行了水煤气气化反应试验,考察了变换剂种类添加量,气化反应温度,反应时间,蒸汽流量对煤气组成的产气率的影响。结果表明,Ca基变换剂可使煤气CO含量ψ降低0.10左右,Ca-Na复合变换剂还可显著提高煤气产率。 相似文献
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通气策略对腹腔镜手术病人肺内分流及氧合的影响 总被引:3,自引:0,他引:3
目的:观察不同潮气量(VT)、呼吸频率(F)、吸呼比(I:E)等通气参数对腹腔镜手术病人肺内分流及氧合情况的影响。方法:25例ASAⅠ~Ⅱ级全麻下择期腹腔镜手术患者随机分为3组,麻醉诱导药物相同,呼吸机参数VT=8ml/kg,F=15次/min,I:E=1:2。气腹后通气参数设定分别为A组VT=10ml/kg。F=12次/min,I:E=1:3;B组VT=6ml/kg,F=20次/min,I:E=1:2;C组同气腹前。分别于气腹前、后测定混合静脉血和动脉血血气,计算各组气腹前后的肺泡气动脉血氧分压差[P(A-a)O2]、呼吸指数(RI)、肺内分流(QS/QT)及氧摄取率(ERO2)。结果:气腹后C组RI增加(P〈0.05),A、C两组的P(A-a)O2升高(P〈0.05),ERO2下降(P〈0.05),而QS/QT增加(P〈0.05),尤以A组QS/QT,增加显著(P〈0.01)。但各组数据组间比较,差异无统计学意义(P〉0.05)。结论:A、B、C3种通气策略对腹腔镜手术病人的P(A-a)O2、QS/QT、ERO2和RI等方面的影响无大差别。 相似文献
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导向喷动流化床生物质快速裂解制液体燃料 总被引:1,自引:0,他引:1
在冷模试验得到的优化的结构参数基础上,建立了一套生物质最大处理量为5kg/h的导向管喷动流化床生物质裂解反应器。反应在常压和440~520℃进行,以木屑为生物质原料,二氧化碳和氮气为喷动气或流化气,沙子为流化介质。结果表明该喷动流化床反应器可用于生物质的快速裂解。在400~480℃,液体产率随温度增加而上升,高于480℃时,二次反应的加剧又导致液体产品产率下降。固体和气体的产率则随温度的升高而减少。喷动气和流化气流量的增加均强化了反应器内的传热,并使生物质初始裂解产物的停留时间减少,二次反应进行程度减弱。在适当的裂解条件下液体产率可达73.2%,此时气体和焦的产率分别为12.8%和14.0%。所得液体产品为单一相液体,含水约30%,可用于燃烧。与流化床相比,喷动流化床作为生物质快速裂解反应器可明显提高液体产率。 相似文献
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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
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Jiageng Zhu Jun Li Ruipeng Ji Jianghao Su Mingshun Shen Zhigang Cao 《南京医科大学学报(自然科学版)》2007,21(2):125-128
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
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APPLICATION OF LORNOXICAM TO PATIENT-CONTROLLED ANALGESIA IN PATIENTS UNDERGOING ABDOMINAL SURGERIES 总被引:13,自引:0,他引:13
Hong Zhao Tie-hu Ye* Zhi-yi Gong Yang Xue Zhang-gang Xue and Wen-qi HuangDepartment of Anesthesiology Peking Union Medical College Hospital Chinese Academy of Medical Sciences & Peking Union Medical College Beijing Department of Anesthesiology Zhongshan Hospital Fudan University Shanghai Department of Anesthesiology the First Affiliated Hospital Zhongshan University Guangzhou 《中国医学科学杂志(英文版)》2005,20(1):59-62
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
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Tao Ye * Zhi-quan Liu Jian-jun Mu Xi-han Fu Jun Yang Bao-lin Gao and Xiao-hong Zhang Department of Cardiology First Hospital of Xi'an Jiaotong University Xi'an Hanzhong Cardiovascular Institute Hanzhong 《中国医学科学杂志(英文版)》2004,19(4):248-251
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
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Xi-zhao Sun Zhi-wei Zhang 《中国医学科学杂志(英文版)》2005,20(3):221-221
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
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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
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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
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People with dysglycemia are at high risk for atherosclerotic diseases. This study aims at investigating the atherosclerotic vascular damage in dysglycemia its metabolic origin in Tibetan population.…… 《中国医学科学杂志(英文版)》2007,22(2):F0003-F0003
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
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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
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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