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Lumped parameter model for resonant frequency estimation of a thermoacoustic engine with gas-liquid coupling oscillation

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第3期12卷 232-237页

作者： Ke TANG tian LEI Xiao-gang LIN Tao JIN Yu ZHANG Institute of Refrigeration and Cryogenics Zhejiang University Hangzhou 310027 China

Gas-liquid coupling oscillation is a novel approach to reducing the resonant frequency and to elevating the pressure amplitude of a thermoacoustic *** a thermoacoustic engine is used to drive low-frequency pulse tube refrigerators,the frequency matching between the thermoacoustic engine and the refrigerator plays an important *** on an acoustic-electric analogy,a lumped parameter model is proposed to estimate the resonant frequency of a standing-wave thermoacoustic engine with gas-liquid coupling ***,a simplified lumped parameter model is also developed to reduce the computation *** resonant frequency dependence on the mean pressure,the gas space volume,and the water column length is computed and *** impact of different working gases on the resonant frequency is also *** effectiveness of the models is validated by comparing the computed results with the experimental data of the gas-liquid coupling oscillation *** increase in the mean working pressure can lead to a rise in the resonant frequency,and a lower resonant frequency can be achieved by elongating the liquid *** comparison with nitrogen and argon,carbon dioxide can realize a lower frequency due to a smaller specific heat ratio.

关键词： Thermoacoustic engine Gas-liquid coupling oscillation Acoustic-electric analogy Resonant frequency

Correlation between ductus venosus spectrum and right ventricular diastolic function in isolated single-umbilical-artery foetus and normal foetus in third trimester

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World Journal of Clinical Cases 2020年第23期8卷 5866-5875页

作者： tian-gang Li Fang Nie Xiao-Yan Xu Department of Ultrasound Diagnosis Gansu Provincial Maternity and Child-Care HospitalLanzhou 730050Gansu ProvinceChina Department of Ultrasound Diagnosis Lanzhou University Second HospitalLanzhou 733000Gansu ProvinceChina

BACKGROUND Single umbilical artery(SUA)is the most common umbilical cord malformation in prenatal *** presence of an SUA can cause blood circulation disorder in the foetus and functional changes of the foetal heart,affecting foetal *** right ventricular diastolic functions in foetuses with isolated SUA and in normal foetuses in the third trimester were evaluated using the spectral Doppler of blood flow in the foetal ductus venosus(DV).AIM To evaluate the right ventricular diastolic functions in foetuses with isolated SUA and in normal foetuses in the third *** Colour Doppler was used to measure the spectrum of foetal DV and tricuspid orifice in 34 foetuses with isolated SUA aged 28-39 wk and in age-matched healthy *** DV flow velocities and velocity ratios were *** early passive/late active(E/A)ratio at the tricuspid orifice and tissue Doppler Tei index of the foetal right ventricular in the two groups were also *** During the third trimester,the isolated SUA group showed a lower‘a’-wave peak velocity in the DV than the control group(P<0.05).The correlations between the velocity ratios and E/A ratio at the tricuspid orifice in the two groups were analysed,and the correlation between the ventricular late diastolic velocity/ventricular diastolic peak flow velocity and E/A ratios was the best(R^2of the isolated SUA group:0.520;R2 of the control group:0.358).The correlations between the velocity ratios and tissue Doppler Tei index of foetal right ventricular in the two groups were analysed,and the correlation between the pulsatility index for veins(PIV)and tissue Doppler Tei index ratios was the best(R2 of the isolated SUA group:0.865;R2 of the control group:0.627).CONCLUSION In the isolated SUA group,the atrial systolic peak velocity‘a’decreased,and this finding might be related to the changes in foetal cardiac *** ratio of ventricular late diastolic velocity to ventricular diastolic peak flow

关键词： Isolated single umbilical artery Ductus venosus Velocity Right ventricular diastolic function Foetus

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介入栓塞治疗食管黏膜下巨大血肿一例

海南医学 2024年第15期35卷 2243-2245页

作者：杨光强李冈栉秦伟胡天刚袁凯川北医学院四川南充637000 遂宁市中心医院四川遂宁629000

一例无明显诱因突发胸骨后疼痛的青年男性患者,诊断考虑食管血肿,经保守治疗后血肿增大,经介入栓塞治疗后止血成功,术后患者恢复良好。食管黏膜下血肿是临床罕见的食管急危重性疾病,介入治疗能及时控制血肿的继续出血,无严重介入术后并... 详细信息

一例无明显诱因突发胸骨后疼痛的青年男性患者,诊断考虑食管血肿,经保守治疗后血肿增大,经介入栓塞治疗后止血成功,术后患者恢复良好。食管黏膜下血肿是临床罕见的食管急危重性疾病,介入治疗能及时控制血肿的继续出血,无严重介入术后并发症。

关键词：食管黏膜下血肿栓塞介入治疗

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天龙竭调控Notch信号通路干预肺纤维化大鼠的实验研究

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时珍国医国药 2024年第9期35卷 2092-2098页

作者：罗婷袁德政李蕾李天纲袁嘉丽付义云南中医药大学云南昆明650500 成都中医药大学四川成都610000 云南省中西医结合慢病防治重点实验室云南昆明650500 辽宁中医药大学附属第四医院辽宁沈阳110101 云南中医药大学第三附属医院云南昆明650504

目的观察天龙竭对博来霉素诱导大鼠肺纤维化的Notch信号通路的影响,探讨天龙竭对肺纤维化(Pulmonary Fi-brosis,PF)的作用机理。方法将60只雄性Wistar大鼠随机分为空白组、模型组、天龙竭低、中、高剂量组、吡非尼酮组,每组10只,空白组... 详细信息

目的观察天龙竭对博来霉素诱导大鼠肺纤维化的Notch信号通路的影响,探讨天龙竭对肺纤维化(Pulmonary Fi-brosis,PF)的作用机理。方法将60只雄性Wistar大鼠随机分为空白组、模型组、天龙竭低、中、高剂量组、吡非尼酮组,每组10只,空白组除外,其余采用气管滴注博莱霉素制备大鼠肺纤维化模型,造模14d后,分别予天龙竭低、中、高剂量灌胃0.51g·kg^(-1)·d^(-1);1.01g·kg^(-1)·d^(-1);2.02g·kg^(-1)·d^(-1),吡非尼酮灌胃(0.12mg·kg^(-1)·d^(-1)),空白组和模型组予以相同量的生理盐水,每日给药1次,给药28d。肺功能检测后,收集肺组织并称重,计算肺指数。通过HE和Masson染色观察大鼠肺组织病理改变;实时荧光定量聚合酶链式反应(Real-time PCR)、蛋白免疫印迹法(Western blotting)检测TGF-β、α-SMA、COL-I、COL-III、Hes1、DLL4、Notch1以及免疫组织化学法检测VEGF的表达情况。结果与空白组比较,模型组大鼠肺指数均升高,HE和Masson染色示肺泡结构被破坏,大量炎性细胞浸润,肺间质大量蓝色胶原纤维沉积,纤维化病灶明显,肺组织TGF-β、α-SMA、VEGF、COL-I/III、Hes1、DLL4、Notch1 mRNA和蛋白表达上调;与模型组比较,天龙竭干预组大鼠肺指数降低,HE和Masson染色示肺组织炎症细胞浸润、肺泡结构破坏和纤维化病灶明显减轻,肺组织TGF-β、α-SMA、VEGF、COL-I/III、Hes1、DLL4、Notch1 mRNA和蛋白表达下调。结论天龙竭能够通过下调Notch信号通路相关基因VEGF、Hes1、DLL4、Notch1的表达,减少肺纤维化指标TGF-β、α-SMA的表达,降低PF大鼠肺指数和减少肺组织中COL-I/III胶原沉积,可能是通过调控Notch信号通路来实现改善肺纤维化。

关键词：天龙竭 Notch信号通路肺纤维化

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钛合金支架及其表面处理技术研究进展

中国口腔颌面外科杂志 2024年第5期22卷 505-509页

作者：陶文昊田刚韩煦祝迎春徐晓刚海军军医大学第一附属医院口腔科上海200433 中国科学院上海硅酸盐研究所中国科学院特种无机涂层重点实验室上海200050

3D打印制造出的Ti-6Al-4V多孔支架相比传统的钛合金支架,力学性能更加接近天然骨组织,具有很好的生物相容性,有望成为骨缺损修复的理想材料。为提升钛合金的生物性能,各种表面处理技术应运而生,这些处理技术可分为涂层法和非涂层法,而... 详细信息

3D打印制造出的Ti-6Al-4V多孔支架相比传统的钛合金支架,力学性能更加接近天然骨组织,具有很好的生物相容性,有望成为骨缺损修复的理想材料。为提升钛合金的生物性能,各种表面处理技术应运而生,这些处理技术可分为涂层法和非涂层法,而不同的表面处理技术各有优劣,本文就钛合金支架及其表面处理技术的研究进展进行综述。

关键词： 3D打印多孔钛合金聚多巴胺羟基磷灰石纤维蛋白原 Ⅰ型胶原蛋白成骨软组织封闭

RCEP协定下跨境电商对贸易影响的时间差异性研究

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对外经贸 2024年第6期 15-19页

作者：胡艳英赵家琪田刚东北林业大学经济管理学院黑龙江哈尔滨150040

为了拓宽双循环渠道,打开外循环新思路,以中国与RCEP成员国在2010年至2021年间进出口面板数据结合中国跨境电商交易额建立VAR模型,研究跨境电子商务发展对我国进出口贸易的动态影响。结果表明,在长期,跨境电商的发展使得发展中国家与我... 详细信息

为了拓宽双循环渠道,打开外循环新思路,以中国与RCEP成员国在2010年至2021年间进出口面板数据结合中国跨境电商交易额建立VAR模型,研究跨境电子商务发展对我国进出口贸易的动态影响。结果表明,在长期,跨境电商的发展使得发展中国家与我国双边贸易弹性系数高于发达国家,跨境电商的发展有利于我国同发展中国家进行贸易往来;在短期,跨境电商的发展对中国与韩国等部分国家的进出口存在逐渐增强的正向影响;跨境电商的发展对我国与多国贸易存在双向动态交互关系。

关键词： RCEP 进出口贸易跨境电商 VAR模型

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鄂尔多斯盆地基底结构特征及演化过程新认识

地球科学 2024年第1期49卷 123-139页

作者：田刚杨明慧宋立军邢舟白东来陈杰李竞赢陕西省煤田物探测绘有限公司陕西西安710005 中国石油大学(北京)地球科学学院北京102249 中国石油大学(北京)油气资源与探测国家重点实验室北京102249 西安石油大学地球科学与工程学院陕西西安710065 中国地质调查局自然资源综合调查指挥中心北京100055

为了解鄂尔多斯盆地基底结构特征,利用1∶20万航磁数据和地震资料,结合盆内基底岩样和周缘前寒武变质岩系的岩石组合、岩石磁性、年代学和地球化学等最新研究进展,分别对基底一级断裂和基底结构特征进行了详细研究.在明确盆内基底各区... 详细信息

为了解鄂尔多斯盆地基底结构特征,利用1∶20万航磁数据和地震资料,结合盆内基底岩样和周缘前寒武变质岩系的岩石组合、岩石磁性、年代学和地球化学等最新研究进展,分别对基底一级断裂和基底结构特征进行了详细研究.在明确盆内基底各区时代属性基础上,尝试恢复了基底古元古代的构造演化过程.盆地基底结构整体上受4条一级断裂控制,将其分为5个二级构造单元.各构造单元岩性为周缘太古-古元古界向盆内的延伸,高航磁异常带主要由太古宙块体反映,负航磁异常带主要由古元古代沉积变质岩反映,显示北东横向分块的特征.古元古代构造演化过程包括>2.2 Ga北部洋壳俯冲早期阶段、~2.2~1.95 Ga俯冲-弧后NE向伸展-表壳岩类沉积阶段、~1.95~1.85 Ga阴山地块与鄂尔多斯地块碰撞-弧后NE向伸展区闭合-形成西部陆块阶段、~1.85~1.80 Ga东部陆块与西部陆块东部碰撞-NE向构造被改造-形成近南北向中部造山带阶段.

关键词：演化过程基底结构基底断裂航磁数据和地震资料鄂尔多斯盆地石油地质

Toxicity of Fluoranthene and Its Biodegradation by Cyclotella caspia Alga

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Journal of Integrative Plant Biology 2006年第2期48卷 169-180页

作者： Yu Liu tian-gang Luan Ning-Ning Lu Chong-Yu Lan School of Life Sciences State Key Laboratory for Biocontrol Sun Yet-sen （Zhongshan） University Guangzhou 510275 China School of Environmental Sciences and Engineering Sun Yet-sen （Zhongshan） University Guangzhou 510275 China

Fluoranthene Is one of the polynuclear aromatic hydrocarbons with four benzene rings. Because of Its toxicity, mutagenlclty, and carclnogenlclty, fluoranthene Is on the black lists of 129 and 68 priority pollutants established by US Environmental Protection Agency and the People＇s Republic of China, respectively. In recent years, the amount of fluoranthene In the aquatic environment has been Increasing with Increases In anthropogenlc discharge. Based on the biological investigation of tidal water In the Futlan mangrove, Cycioteila ~aspla was selected as the dominant algal species to determine the toxicity of fluoranthene towards C. caspla alga and to Investigate the blodegradatlon of fluoranthene by C. caspla under pure culture. The toxicity experiment showed that the 96-h EC50 value for fluoranthene was 0.2 mg/mL. Four parameters, namely C. caspla algal growth rate, chlorophyll （Chl） a content, cell morphology, and superoxlde dlsmutase （SOD） activity, were chosen as Indices of toxicity and were measured at 6 d （144 h）. The results showed that：（Ⅰ） the toxicity of fluoranthene towards C. caspla alga was obvious; （Ⅱ） C. caspla algal growth rate and Chl a content decreased with Increasing concentrations of fluoranthene; and （Ⅲ） the rate of cell deformation and SOD activity Increased with Increasing concentrations of fluoranthene. The blodegradatlon experiment showed that：（Ⅰ） the rate of physical degradation of fluoranthene was only 5.86%; （Ⅱ） the rate of blodegradatlon of fluoranthene on the 1st and 6th days （l.e. at 24 and 144 h） was approximately 35% and 85%, respectively; and （Ⅲ） the blodegradatlon capability of C. caspla alga towards fluoranthene was high. It is suggested that further Investigations on the toxicity of fluoranthene towards algae, as well as on algal blodegradatlon mechanisms, are of great Importance to use C. caspla as a biological treatment species In an organic wastewater treatment system.

关键词： biodegradation Cyclotella caspia fluoranthene toxicity.

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盾构弃渣在壁后注浆中绿色再利用试验研究

甘肃科学学报 2024年第1期36卷 87-93,116页

作者：陈时光田刚李海张博玮陶津中建八局轨道交通建设有限公司江苏南京210008 东南大学土木工程学院江苏南京210096

为解决泥水平衡盾构的弃渣显著增加施工成本,且极易造成环境污染的常见问题,依托南京市江宁区新济洲供水工程过江廊道工程,考虑掘进线路处于黏土地层,提出了弃渣取代同步注浆原材料的再利用研究方案。探讨了弃渣取代膨润土原材料的可行... 详细信息

为解决泥水平衡盾构的弃渣显著增加施工成本,且极易造成环境污染的常见问题,依托南京市江宁区新济洲供水工程过江廊道工程,考虑掘进线路处于黏土地层,提出了弃渣取代同步注浆原材料的再利用研究方案。探讨了弃渣取代膨润土原材料的可行性,通过正交设计试验测试了浆液性能,研究了各种渣土情况下的浆液性质的变化。研究发现,经初步处理后的泥水盾构弃渣可取代膨润土材料,最优配比下同步注浆浆液的比重为1.812 g/cm^(3),稠度为14.25 cm,初凝时间为10.55 h,2 h泌水率为1.41%,28 d体积收缩率为0.0147%。研究结果表明,泥水盾构弃渣各项指标均能满足南京市江宁区新济洲供水工程过江廊道工程现场同步注浆性能要求,且该技术的经济和环境效益显著,可为后续相似工程建设提供一定的参考。

关键词：盾构隧道壁后注浆绿色施工弃渣膨润土

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