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车用柴油机高压比宽流量增压器研制
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作者 邢卫东 佟鼎 +3 位作者 刘莹 邓春龙 门日秀 吴新涛 《装备环境工程》 CAS 2024年第6期37-44,共8页
目的 对于单级高压比宽流量增压器,为适应发动机强化指标,进行一系列的改进设计。方法 利用仿真设计与试验相结合的方法,对高海拔环境应用增压器进行改进设计。通过理论推导,确定压气机及涡轮的气动性能优化设计方法,开展高稳定裕度转... 目的 对于单级高压比宽流量增压器,为适应发动机强化指标,进行一系列的改进设计。方法 利用仿真设计与试验相结合的方法,对高海拔环境应用增压器进行改进设计。通过理论推导,确定压气机及涡轮的气动性能优化设计方法,开展高稳定裕度转子轴承系统设计方法研究与验证。结果 匹配高压比宽流量增压器的发动机与原机相比,高原功率恢复了17%,发动机排气温度降低了7%,增压器转速降低了13%。结论 在原机的基础上设计了压比为4.6的宽流量高性能涡轮增压器,成功实现了高压比宽流量增压器的设计,满足了发动机平原、高原不同环境的运行需求。 展开更多
关键词 高压比 增压器 压气机 涡轮 转子 高海拔环境
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Boosting Fischer-Tropsch Synthesis via Tuning of N Dopants in TiO_(2)@CN-Supported Ru Catalysts 被引量:1
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作者 Xincheng Li Yunhao Liu +10 位作者 Dejian Zhao Shuaishuai Lyu Jingwei Ye Xiaoshen Li Peipei Wu Ye Tian Yingtian Zhang tong ding Song Song Qingpeng Cheng Xingang Li 《Transactions of Tianjin University》 EI CAS 2024年第1期90-102,共13页
Nitrogen(N)-doped carbon materials as metal catalyst supports have attracted signifi cant attention,but the eff ect of N dopants on catalytic performance remains unclear,especially for complex reaction processes such ... Nitrogen(N)-doped carbon materials as metal catalyst supports have attracted signifi cant attention,but the eff ect of N dopants on catalytic performance remains unclear,especially for complex reaction processes such as Fischer-Tropsch synthesis(FTS).Herein,we engineered ruthenium(Ru)FTS catalysts supported on N-doped carbon overlayers on TiO_(2)nanoparticles.By regulating the carbonization temperatures,we successfully controlled the types and contents of N dopants to identify their impacts on metal-support interactions(MSI).Our fi ndings revealed that N dopants establish a favorable surface environment for electron transfer from the support to the Ru species.Moreover,pyridinic N demonstrates the highest electron-donating ability,followed by pyrrolic N and graphitic N.In addition to realizing excellent catalytic stability,strengthening the interaction between Ru sites and N dopants increases the Ru^(0)/Ru^(δ+)ratios to enlarge the active site numbers and surface electron density of Ru species to enhance the strength of adsorbed CO.Consequently,it improves the catalyst’s overall performance,encompassing intrinsic and apparent activities,as well as its ability for carbon chain growth.Accordingly,the as-synthesized Ru/TiO_(2)@CN-700 catalyst with abundant pyridine N dopants exhibits a superhigh C_(5+)time yield of 219.4 mol CO/(mol Ru·h)and C_(5+)selectivity of 85.5%. 展开更多
关键词 Fischer-Tropsch synthesis N-doped carbon materials Ruthenium catalyst Pyridinic N Metal-N interaction
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IoV environment exploring coordination:A federated learning approach
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作者 tong ding Lei Liu +2 位作者 Yi Zhu Lizhen Cui Zhongmin Yan 《Digital Communications and Networks》 SCIE CSCD 2024年第1期135-141,共7页
Exploring open fields with coordinated unmanned vehicles is popular in academia and industries.One of the most impressive applicable approaches is the Internet of Vehicles(lov).The IoV connects vehicles,road infrastru... Exploring open fields with coordinated unmanned vehicles is popular in academia and industries.One of the most impressive applicable approaches is the Internet of Vehicles(lov).The IoV connects vehicles,road infrastructures and communication facilities to provide solutions for exploration tasks.However,the coordination of acquiring information from multi-vehicles may risk data privacy.To this end,sharing high-quality experiences instead of raw data has become an urgent demand.This paper employs a Deep Reinforcement Learning(DRL)method to enable IoVs to generate training data with prioritized experience and states,which can support the IoV to explore the environment more efficiently.Moreover,a Federated Learning(FL)experience sharing model is established to guarantee the vehicles'privacy.The numerical results show that the proposed method presents a better successful sharing rate and a more stable convergence within the comparison of fundamental methods.The experiments also suggest that the proposed method could support agents without full information to achieve the tasks. 展开更多
关键词 Internet of vehicle Deep reinforcement learning Federated learning Data privacy
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Risk Factors of the Progression of Renal Function Deterioration Among Patients with Diabetic Nephropathy
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作者 Nan Bao tong ding +2 位作者 Yanting Gao Yanting Zhu Pengjie Zhang 《Journal of Clinical and Nursing Research》 2024年第1期7-12,共6页
Objective:To explore the risk factors for the progression of renal function deterioration in patients with diabetic nephropathy(DN).Methods:The clinical data and biochemical indexes of 100 diabetic patients admitted t... Objective:To explore the risk factors for the progression of renal function deterioration in patients with diabetic nephropathy(DN).Methods:The clinical data and biochemical indexes of 100 diabetic patients admitted to our hospital from October 2021 to October 2022 were retrospectively analyzed.The patients were divided into a DN group,which consisted of 55 cases,and a nondiabetic nephropathy group(NDN),which consisted of 45 cases.The urinary microalbumin to creatinine ratio,the clinical data(gender,age,duration of the disease,and BMI),and the biochemical indexes(triglycerides[TG],low-density lipoprotein cholesterol[LDL-C],high-density lipoprotein cholesterol[HDL-C],total cholesterol[TC],glycated hemoglobin A1c[HbA1c],systolic blood pressure[SBP],diastolic blood pressure[DBP])of the two groups were compared.Subsequently,the risk factors related to the progression of renal function deterioration in DN were analyzed through multifactorial logistic regression analysis.Results:No statistically significant difference was observed in the comparison of gender,age,BMI,LDL-C,and DBP between the two groups(P>0.05).The DN group demonstrated a longer disease duration and higher SBP,TC,HDL-C,HbA1c,and TG compared to the NDN group(P<0.05).Through multifactorial logistic regression analysis,it was found that the duration of the disease,the TC,the HDL-C,the HbA1c,the TG,and the SBP were independent risk factors of the deterioration of renal function in DN patients.Conclusion:Other than conventional indicators,TC,HDL-C,HbA1c,TG,and SBP are also crucial indicators in determining the progression of renal function deterioration in DN patients. 展开更多
关键词 Diabetic nephropathy Renal function deterioration Risk factors
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涡轮增压器轴向力变化规律试验与仿真 被引量:2
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作者 王翠翠 闫瑞乾 +4 位作者 丁占铭 佟鼎 吴新涛 高超 庄丽 《兵工学报》 EI CAS CSCD 北大核心 2023年第1期307-315,共9页
提出一种基于悬浮式设计的涡轮增压器轴向力测量方案,解决涡轮增压器轴向力测量范围窄和零点漂移问题,通过试验测量了增压器转子轴向载荷。进一步建立包含轮背间隙、密封环间隙的增压器压气机和涡轮仿真分析模型,基于试验结果验证模型... 提出一种基于悬浮式设计的涡轮增压器轴向力测量方案,解决涡轮增压器轴向力测量范围窄和零点漂移问题,通过试验测量了增压器转子轴向载荷。进一步建立包含轮背间隙、密封环间隙的增压器压气机和涡轮仿真分析模型,基于试验结果验证模型的可靠性,并应用该模型研究揭示了增压器压轮和涡轮轴向力随工况的一般变化规律。研究结果表明:外吹状态时,在同一转速下增压器转子轴向力值随压气机端质量流量的减小而增大;自循环状态时,在转速低于额定转速时,增压器转子轴向力随转速的增加而增大,在转速高于额定转速时,增压器转子轴向力随转速的增加而减小;同一转速下,除喘振点附近,压气机轴向载荷随入口质量流量的减小而增大,涡轮轴向载荷随涡轮入口质量流量的增加而增大;压端和涡端轴向载荷最大的两个区域均为叶轮背盘和叶轮轮毂,且两区域轴向载荷方向相反。 展开更多
关键词 涡轮增压器 止推轴承 轴向力 数值模拟计算
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早产儿视网膜病变抗VEGF治疗进展 被引量:1
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作者 丁瞳 陈宜 《国际眼科杂志》 CAS 北大核心 2023年第8期1328-1332,共5页
早产儿视网膜病变(retinopathy of prematurity,ROP)是发生于早产儿的一种未成熟视网膜血管增生性眼病,是发展中及发达国家儿童致盲的主要因素。ROP的传统治疗方法是视网膜激光光凝或冷冻治疗,但凝固治疗可导致视网膜永久性破坏,存在发... 早产儿视网膜病变(retinopathy of prematurity,ROP)是发生于早产儿的一种未成熟视网膜血管增生性眼病,是发展中及发达国家儿童致盲的主要因素。ROP的传统治疗方法是视网膜激光光凝或冷冻治疗,但凝固治疗可导致视网膜永久性破坏,存在发生视野缺损、高度近视等并发症风险。玻璃体腔注射抗血管内皮细胞生长因子(VEGF)药物治疗ROP后视网膜功能的发育比凝固治疗更趋向正常,再加上操作简便、耗时短等优点,玻璃体腔注射抗VEGF药物逐渐成为ROP的重要治疗方式;在Ⅰ区ROP、Ⅱ区后部ROP和急进型ROP治疗中为首选治疗方式。但是抗VEGF药物治疗ROP所致的严重系统并发症、最低有效剂量及后期复发情况等问题尚待进一步研究。本文将对ROP抗VEGF治疗现状进行综述。 展开更多
关键词 早产儿视网膜病变 血管内皮细胞生长因子(VEGF) 抗血管内皮细胞生长因子药物
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叶片前缘前掠对离心压气机性能的影响 被引量:1
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作者 王宪磊 刘欣源 +3 位作者 张强 佟鼎 王依宁 赵洋 《车用发动机》 北大核心 2023年第4期21-28,共8页
为了研究叶片前缘倾掠对离心压气机性能及稳定工况范围的影响,在叶片前缘处沿子午面弦长方向进行前缘前掠,前掠角分别为5°,10°和15°,实现了3种不同前掠角的叶片前缘前掠叶形。仿真后处理分析表明:前缘前掠叶形可提高压... 为了研究叶片前缘倾掠对离心压气机性能及稳定工况范围的影响,在叶片前缘处沿子午面弦长方向进行前缘前掠,前掠角分别为5°,10°和15°,实现了3种不同前掠角的叶片前缘前掠叶形。仿真后处理分析表明:前缘前掠叶形可提高压气机最高等熵效率和压比,并且可提高其流量范围;在前缘前掠的基础上进行自由掠叶形设计,自由掠叶形表现出更高的等熵效率和压比,且自由掠叶形可降低叶轮进口处的激波强度,减少激波损失。经过台架试验验证后发现,自由掠叶形与无掠叶形相比等熵效率和压比均得到有效提升,且流量范围也得到了提升。 展开更多
关键词 离心压气机 数值仿真 前缘前掠 计算流体力学
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离心压气机叶片式机匣拓稳流动特性 被引量:3
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作者 田红艳 侯康 +3 位作者 佟鼎 刘欣源 王宪磊 赵洋 《内燃机学报》 EI CAS CSCD 北大核心 2023年第4期361-368,共8页
内燃机功率提高以及高原、高空功率恢复的要求,推动着内燃机增压比不断提高,高增压技术成为先进内燃机发展的核心关键技术之一.提高压比将导致离心压气机稳定工作范围和效率急剧降低,高压比离心压气机的气动稳定性与扩稳成为高增压技术... 内燃机功率提高以及高原、高空功率恢复的要求,推动着内燃机增压比不断提高,高增压技术成为先进内燃机发展的核心关键技术之一.提高压比将导致离心压气机稳定工作范围和效率急剧降低,高压比离心压气机的气动稳定性与扩稳成为高增压技术研究的核心和难点.为拓宽跨声速离心压气机的稳定工作范围,对一种离心压气机叶片式机匣处理结构开展了研究,利用数值模拟研究了叶片式机匣内部流动特性与拓稳机理,并对导叶形式进行了优化,最后通过试验进行验证,结果表明:采用优化的导叶机匣处理结构,能够有效拓宽离心压气机高压比流动范围,喘振流量可拓宽6%~8%. 展开更多
关键词 离心压气机 叶片式机匣 高压比 数值模拟
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Diversity of Intestinal Flora in Elderly Patients with Type 2 Diabetes Mellitus with Early Nephropathy 被引量:1
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作者 Nan Bao tong ding +2 位作者 Yanting Gao Yanting Zhu Bing Wu 《Journal of Clinical and Nursing Research》 2023年第6期167-171,共5页
Objective:To investigate the intestinal flora in elderly patients with type 2 diabetes mellitus with early nephropathy.Methods:43 elderly patients with type 2 diabetes mellitus with early nephropathy(diabetic nephropa... Objective:To investigate the intestinal flora in elderly patients with type 2 diabetes mellitus with early nephropathy.Methods:43 elderly patients with type 2 diabetes mellitus with early nephropathy(diabetic nephropathy group)and 51 elderly patients with type 2 diabetes mellitus(type 2 diabetes mellitus group)admitted to our hospital from January 2021 to October 2022 were retrospectively analyzed,with 39 healthy people who underwent a physical examination in our hospital during the same period as the control group.The fecal specimens of the three groups were collected,and the 16S rDNAs of bacteria in the fecal samples were extracted,amplified,and sequenced for intestinal flora operational taxonomic unit(OTU)classification and Alpha diversity analysis.Results:(1)Intestinal flora OTUs:there were 545 intestinal flora OTUs unique to the control group,424 intestinal flora OTUs unique to diabetic nephropathy,and 321 intestinal flora OTUs unique to the type 2 diabetes group.There were 403 intestinal flora OTUs common to the control group and diabetic nephropathy group,256 intestinal flora OTUs common to the control group and type 2 diabetes group,and 298 intestinal flora OTUs common to the type 2 diabetes group and diabetic nephropathy group.235 intestinal flora OTUs were common to all 3 groups of subjects.(2)Alpha diversity:The statistical analysis indicated that there was a statistically significant difference(P<0.05)in the Alpha diversity of intestinal flora,as assessed by the Ace index and Simpson’s index,among the three subject groups.However,no statistical significance(P>0.05)was observed when comparing the Chao 1 index and Shannon index.Further observation of the Ace index and Simpson index in the three groups revealed that both the diabetic nephropathy group and the type 2 diabetes mellitus group had lower values than the control group.Conclusion:The diversity of intestinal flora decreases in elderly patients with type 2 diabetes mellitus with early nephropathy. 展开更多
关键词 Elderly type 2 diabetes mellitus NEPHROPATHY Intestinal flora DIVERSITY
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Galectin-14 promotes hepatocellular carcinoma tumor growth via enhancing heparan sulfate proteoglycan modification
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作者 Liming Gou Gang Yang +5 位作者 Sujuan Ma tong ding Luan Sun Fang Liu Jin Huang Wei Gao 《The Journal of Biomedical Research》 CAS CSCD 2023年第6期418-430,共13页
Hepatocellular carcinoma(HCC)is a highly heterogeneous malignancy and lacks effective treatment.Bulk-sequencing of different gene transcripts by comparing HCC tissues and adjacent normal tissues provides some clues fo... Hepatocellular carcinoma(HCC)is a highly heterogeneous malignancy and lacks effective treatment.Bulk-sequencing of different gene transcripts by comparing HCC tissues and adjacent normal tissues provides some clues for investigating the mechanisms or identifying potential targets for tumor progression.However,genes that are exclusively expressed in a subpopulation of HCC may not be enriched or detected through such a screening.In the current study,we performed a single cell-clone-based screening and identified galectin-14 as an essential molecule in the regulation of tumor growth.The aberrant expression of galectin-14 was significantly associated with a poor overall survival of liver cancer patients with database analysis.Knocking down galectin-14 inhibited the proliferation of tumor growth,whereas overexpressing galectin-14 promoted tumor growth in vivo.Non-targeted metabolomics analysis indicated that knocking down galectin-14 decreased glycometabolism;specifically that glycoside synthesis was significantly changed.Further study found that galectin-14 promoted the expression of cell surface heparan sulfate proteoglycans(HSPGs)that functioned as co-receptors,thereby increasing the responsiveness of HCC cells to growth factors,such as epidermal growth factor and transforming growth factor-alpha.In conclusion,the current study identifies a novel HCC-specific molecule galectin-14,which increases the expression of cell surface HSPGs and the uptake of growth factors to promote HCC cell proliferation. 展开更多
关键词 hepatocellular carcinoma galectin-14 heparan sulfate proteoglycans CO-RECEPTOR
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Continuous renal replacement therapy with oXiris®in patients with hematologically malignant septic shock:A retrospective study
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作者 Juan Wang Shu-Run Wei +10 位作者 tong ding Li-Ping Zhang Zhi-Hua Weng Ming Cheng Yang Zhou Meng Zhang Fang-Jun Liu Bei-Bei Yan Dan-Feng Wang Ming-Wen Sun Wei-Xin Cheng 《World Journal of Clinical Cases》 SCIE 2023年第26期6073-6082,共10页
BACKGROUND The mortality rate from septic shock in patients with hematological malignancies(HMs)remains significantly higher than that in patients without HMs.A longer resuscitation time would definitely be harmful be... BACKGROUND The mortality rate from septic shock in patients with hematological malignancies(HMs)remains significantly higher than that in patients without HMs.A longer resuscitation time would definitely be harmful because of the irreversibly immunocompromised status of the patients.Shortening the resuscitation time through continuous renal replacement therapy(CRRT)with oXiris^(■)would be an attractive strategy in managing such patients.AIM To explore the effects of CRRT and oXiris^(■)in shortening the resuscitation time and modifying the host response by reducing inflammation mediator levels.METHODS Forty-five patients with HM were diagnosed with septic shock and underwent CRRT between 2018 and 2022.Patients were divided into two groups based on the hemofilter used for CRRT(oXiris^(■)group,n=26;M150 group,n=19).We compared the number of days of negative and total fluid balance after 7 d of CRRT between the groups.The heart rate,norepinephrine dose,Sequential Organ Failure Assessment(SOFA)score,and blood lactic acid levels at different time points in the two groups were also compared.Blood levels of inflammatory mediators in the 26 patients in the oXiris^(■)group were measured to further infer the possible mechanism.RESULTS The average total fluid balance after 7 d of CRRT in the oXiris^(■)group was significantly lower than that of patients in the M150 hemofilter group.The SOFA scores of patients after CRRT with oXiris^(■)therapy were significantly lower than those before treatment on day 1(d1),d3 and d7 after CRRT;these parameters were also significantly lower than those of the control group on d7.The lac level after oXiris^(■)therapy was significantly lower than that before treatment on d3 and d7 after CRRT.There were no significant differences in the above parameters between the two groups at the other time points.In the oXiris^(■)group,procalcitonin levels decreased on d7,whereas interleukin-6 and tumor necrosis factor levels decreased significantly on d3 and d7 after treatment.CONCLUSION CRRT with oXiris^(■)hemofilter may improve hemodynamics by reducing inflammatory mediators and playing a role in shortening the resuscitation period and decreasing total fluid balance in the resuscitation phases. 展开更多
关键词 Hematological malignancy Septic shock oXiris®hemofilter Blood purification Fluid balance
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进气弯管对离心压气机特性影响及弯管结构优化 被引量:2
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作者 佟鼎 田红艳 +3 位作者 刘欣源 刘烨 高超 李欣 《兵工学报》 EI CAS CSCD 北大核心 2021年第4期706-714,共9页
离心压气机进口常采用弯管导流进气,弯管中的二次流动会导致压气机进口气流出现畸变,影响压气机的气动性能。针对这一问题,通过数值仿真与台架试验相结合的方式,研究弯管对离心压气机特性的影响规律及产生机理。在此基础上提出在弯管内... 离心压气机进口常采用弯管导流进气,弯管中的二次流动会导致压气机进口气流出现畸变,影响压气机的气动性能。针对这一问题,通过数值仿真与台架试验相结合的方式,研究弯管对离心压气机特性的影响规律及产生机理。在此基础上提出在弯管内增加导流肋片的改进方法,并进行数值仿真与试验验证。研究结果表明:在压气机进口增加弯管后,压比和效率特性都发生了一定程度的恶化,在大流量工况时,性能的下降尤其显著;采用内部布置导流肋片的弯管结构,能够进一步规范弯管内部气流的流动特征,改善压气机进口流动状态,使流动变得相对均匀,从而使性能得到全方位的提升。 展开更多
关键词 跨声速离心压气机 进气弯管 导流肋片 数值模拟
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离心压气机非对称有叶扩压器拓稳流动方法研究
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作者 佟鼎 田红艳 +6 位作者 刘欣源 何海龙 刘莹 邢卫东 吉建波 李广瑞 贾晓亮 《车用发动机》 北大核心 2018年第6期17-22,28,共7页
离心压气机是涡轮增压器的核心部件,对于高压比离心压气机来讲,一般采用有叶扩压器。与无叶扩压器相比,在相同直径比时,有叶扩压器具有更大的扩压能力和更高的效率。但是,受扩压器叶片攻角的影响,压气机非设计工况效率比无叶扩压器要低... 离心压气机是涡轮增压器的核心部件,对于高压比离心压气机来讲,一般采用有叶扩压器。与无叶扩压器相比,在相同直径比时,有叶扩压器具有更大的扩压能力和更高的效率。但是,受扩压器叶片攻角的影响,压气机非设计工况效率比无叶扩压器要低,而且压气机稳定工作范围变窄。本研究针对有叶扩压器离心压气机流动稳定性的提升,通过蜗壳非对称性对有叶扩压器内部流动的影响研究,改变蜗壳喉口处对应扩压器叶片分布形式以及叶片的安装角,设计了一种非对称有叶扩压器结构,并分析了有叶扩压器内部流动特性的变化,最终通过了台架试验验证。验证结果表明:采用非对称有叶扩压器结构能够有效拓宽离心压气机的稳定工作范围,在高压比区域,较对称叶片式扩压器离心压气机流量范围提升10%左右。 展开更多
关键词 压气机 有叶扩压器 流动分布 台架试验
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双离心压气机共用单一进气歧管致进口流场畸变的仿真分析
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作者 佟鼎 田红艳 +2 位作者 邢卫东 刘莹 刘欣源 《内燃机工程》 EI CAS CSCD 北大核心 2020年第4期63-69,共7页
针对V型发动机的共用单一管路对置离心压气机进口流场畸变特性进行了研究,通过台架试验测试了初始压气机性能,完成了仿真模型的标定。在此基础上分析了压气机进口流场的变化特征,分析结果表明:共用单一管路对压气机特性影响明显,造成了... 针对V型发动机的共用单一管路对置离心压气机进口流场畸变特性进行了研究,通过台架试验测试了初始压气机性能,完成了仿真模型的标定。在此基础上分析了压气机进口流场的变化特征,分析结果表明:共用单一管路对压气机特性影响明显,造成了两侧压气机堵塞流量的降低,在大流量工况区域效率明显下降,右侧压气机恶化程度要明显高于左侧。原因在于受安装位置空间限制,喉口处畸变扩展与进口周向畸变叠加效应使得右侧压气机在周向和叶高方向的畸变程度均高于左侧压气机。进口的畸变效应会一直持续至压气机叶轮内部,使压气机性能变差。 展开更多
关键词 进口畸变 离心压气机 Y型管路 数值模拟
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某型涡轮增压器的多应力耦合分析与测试验证
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作者 钱云鹏 刘勤 +2 位作者 佟鼎 刘英 花琳 《兵器装备工程学报》 CAS 北大核心 2020年第S02期162-167,共6页
针对某型车用发动机涡轮增压器,考虑热、机械、气动载荷等多应力耦合作用建立了涡轮气固热耦合仿真模型,通过气动流体稳态分析获得流固交界面的压力、温度分布,随后进行稳态热分析确定固体域的温度分布,最后综合考虑热应力、气动压力和... 针对某型车用发动机涡轮增压器,考虑热、机械、气动载荷等多应力耦合作用建立了涡轮气固热耦合仿真模型,通过气动流体稳态分析获得流固交界面的压力、温度分布,随后进行稳态热分析确定固体域的温度分布,最后综合考虑热应力、气动压力和旋转离心力获得涡轮的综合应力和温度分布。为了验证应力分析结果,采用热电偶和非接触应力测试系统测试涡轮工作过程中的表面温度和叶片尖端应力,结果表明仿真温度误差为5.2%,应力误差为7.1%,满足工程要求,为后续可靠性分析和耐久性分析奠定了基础。 展开更多
关键词 多应力耦合 多物理场仿真 涡轮增压器 涡轮 测试验证
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车用跨声速离心压气机高原适应性改进设计
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作者 佟鼎 刘贵升 +4 位作者 林森 宋志伟 王宪磊 贾晓亮 马锦荣 《车用发动机》 北大核心 2021年第2期18-24,共7页
针对某增压器原机高原适应性不足的问题,开展了一维初始目标设计和详细的三维流动仿真分析,对车用跨声速离心压气机进行了高原适应性改进设计。通过降低叶片后弯角、增加叶片数进而增加叶轮做功能力来提升压比。通过叶片细节设计,包括... 针对某增压器原机高原适应性不足的问题,开展了一维初始目标设计和详细的三维流动仿真分析,对车用跨声速离心压气机进行了高原适应性改进设计。通过降低叶片后弯角、增加叶片数进而增加叶轮做功能力来提升压比。通过叶片细节设计,包括分流叶片前掠和出口曲线掠型进一步优化压气机性能,最终通过了试验验证,在原机的基础上成功优化设计了高压比离心压气机,满足了发动机的使用需求。 展开更多
关键词 离心压气机 高原适应性 改进设计 台架试验
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前/尾缘自由掠叶型跨声速离心压气机叶轮流动特性 被引量:4
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作者 田红艳 佟鼎 +2 位作者 张俊跃 程江华 刘欣源 《内燃机学报》 EI CAS CSCD 北大核心 2021年第6期554-560,共7页
针对某跨声速离心压气机叶轮,对其前/尾缘叶型进行了自由掠叶型的改进,并开展了相应的数值分析和试验验证,结果表明:在全转速范围内,离心叶轮前缘采用前自由掠叶型能够使叶轮更加适应进口的跨声速流动,有效改善叶轮进口的激波形态,增大... 针对某跨声速离心压气机叶轮,对其前/尾缘叶型进行了自由掠叶型的改进,并开展了相应的数值分析和试验验证,结果表明:在全转速范围内,离心叶轮前缘采用前自由掠叶型能够使叶轮更加适应进口的跨声速流动,有效改善叶轮进口的激波形态,增大堵塞流量,降低激波损失,增加效率.尾缘采用后自由掠叶型能够增加出口叶片的做功面积,抑制叶片尾缘间隙流动与主流结合形成的低能流团,从而使压比和稳定性提升.最后,针对设计的前/尾缘自由掠叶型跨声速离心压气机叶轮,开展了台架性能试验,验证了仿真分析结果. 展开更多
关键词 离心压气机 自由掠叶型 数值模拟 台架试验
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双分流叶片跨声速离心压气机流动特性仿真研究 被引量:2
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作者 刘贵升 佟鼎 +4 位作者 李广瑞 李晶晶 侯琳琳 花琳 庄丽 《车用发动机》 北大核心 2020年第5期36-40,共5页
以某高压比跨声速离心叶轮为基础,为进一步强化其性能,对双分流叶片叶轮内部流动特性进行了仿真分析。研究结果表明:采用双分流叶片结构,能够改善堵塞工况的流动,降低主叶片前缘激波强度和叶片表面载荷,随着转速的提升,压比提升效果明显... 以某高压比跨声速离心叶轮为基础,为进一步强化其性能,对双分流叶片叶轮内部流动特性进行了仿真分析。研究结果表明:采用双分流叶片结构,能够改善堵塞工况的流动,降低主叶片前缘激波强度和叶片表面载荷,随着转速的提升,压比提升效果明显;在数量改进的约束条件下,两种双分流叶片结构各有其特点,所得到的结果为高压比离心压气机叶轮性能优化提供新的思路。 展开更多
关键词 离心压气机 双分流叶片 仿真 流动分布
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进口端壁导叶对离心压气机特性影响研究 被引量:2
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作者 田红艳 侯康 +1 位作者 佟鼎 刘欣源 《内燃机工程》 CAS CSCD 北大核心 2021年第6期95-102,共8页
针对进口端壁导叶对离心压气机的特性影响进行了研究,基于试验验证的压气机性能对仿真模型进行标定,并对压气机内部的流动特性进行了详细的分析。结果表明:正预旋导叶使压气机的阻塞流量和喘振流量向小流量方向偏移,可有效提升离心压气... 针对进口端壁导叶对离心压气机的特性影响进行了研究,基于试验验证的压气机性能对仿真模型进行标定,并对压气机内部的流动特性进行了详细的分析。结果表明:正预旋导叶使压气机的阻塞流量和喘振流量向小流量方向偏移,可有效提升离心压气机的稳定性。负预旋导叶在流量特性上与正预旋刚好相反,使压气机特性向大流量工况偏移。进口预旋导叶的存在明显改变了叶轮进口的相对气流角,正预旋能够使得入流气流冲角变小从而提升效率,负预旋会使压气机效率特性变差。端壁正预旋导叶使离心压气机堵塞流量略有降低,但效率和稳定性明显提升。试验证实了理论结果的正确性。 展开更多
关键词 端壁导叶 离心压气机 流动特性 数值仿真
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白内障术中灌注压对视网膜结构及功能的影响 被引量:1
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作者 丁瞳 邱伟强 《国际眼科杂志》 CAS 北大核心 2018年第8期1420-1423,共4页
白内障超声乳化术日益普及,为提高手术效率,很多医师会应用高负压、高灌注压。高灌注压可维持前房的稳定性,但同时急性高眼压状态也会引起视网膜结构及功能的变化。现主要对白内障术中高灌注压对视网膜结构及功能的影响研究进展进行综述。
关键词 灌注压 高眼压 白内障 超声乳化手术 神经节细胞
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