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Effects of fuel combination and IVO timing on combustion and emissions of a dual-fuel HCCI combustion

Xin LIANG, Jianyong ZHANG, Zhongzhao LI, Jiabo ZHANG, Zhen HUANG, Dong HAN

《能源前沿（英文）》 2020年 第14卷 第4期   页码 778-789 doi: 10.1007/s11708-020-0698-8

摘要： This paper experimentally and numerically studied the effects of fuel combination and intake valve opening (IVO) timing on combustion and emissions of an n-heptane and gasoline dual-fuel homogeneous charge compression ignition (HCCI) engine. By changing the gasoline fraction (GF) from 0.1 to 0.5 and the IVO timing from –15°CA ATDC to 35°CA ATDC, the in-cylinder pressure traces, heat release behaviors, and HC and CO emissions were investigated. The results showed that both the increased GF and the retarded IVO timing delay the combustion phasing, lengthen the combustion duration, and decrease the peak heat release rate and the maximum average combustion temperature, whereas the IVO timing has a more obvious influence on combustion than GF. HC and CO emissions are decreased with reduced GF, advanced IVO timing and increased operational load.

关键词： homogeneous charge compression ignition     dual-fuel     n-heptane     gasoline     intake valve opening timing    

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一种混合电磁气门驱动机构设计 Article

Jawad ASLAM, Xing-hu LI, Faira Kanwal JANJUA

《信息与电子工程前沿（英文）》 2017年 第18卷 第10期   页码 1635-1643 doi: 10.1631/FITEE.1601215

摘要： 对该机构同双电磁阀驱动机构（double solenoid valve actuator，DSVA）进行了比较分析。所提机构和DSVA有限元设计方法经过自主制作的试验样机验证。

关键词： 永磁；电磁；可变气门正时；无凸轮轴发动机；磁动势    

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J-shaped association between dietary zinc intake and new-onset hypertension: a nationwide cohort study

《医学前沿（英文）》 2023年 第17卷 第1期   页码 156-164 doi: 10.1007/s11684-022-0932-3

摘要： We aimed to investigate the relationship of dietary zinc intake with new-onset hypertension among Chinese adults. A total of 12,177 participants who were free of hypertension at baseline from the China Health and Nutrition Survey were included. Dietary intake was assessed by three consecutive 24-h dietary recalls combined with a household food inventory. Participants with systolic blood pressure ≥ 140 mmHg or diastolic blood pressure ≥ 90 mmHg or diagnosed by a physician or under antihypertensive treatment during the follow-up were defined as having new-onset hypertension. During a median follow-up duration of 6.1 years, 4269 participants developed new-onset hypertension. Overall, the association between dietary zinc intake and new-onset hypertension followed a J-shape (P for non-linearity < 0.001). The risk of new-onset hypertension significantly decreased with the increment of dietary zinc intake (per mg/day: hazard ratio (HR) 0.93; 95% confidence interval (CI) 0.88–0.98) in participants with zinc intake < 10.9 mg/day, and increased with the increment of zinc intake (per mg/day: HR 1.14; 95% CI 1.11–1.16) in participants with zinc intake ≥ 10.9 mg/day. In conclusion, there was a J-shaped association between dietary zinc intake and new-onset hypertension in general Chinese adults, with an inflection point at about 10.9 mg/day.

关键词： dietary zinc intake     new-onset hypertension     general population     CHNS    

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Water pumping analysis and experimental validation of beach well infiltration intake system in a seawater

Huan ZHANG,Shu LIU,Xuejing ZHENG,Gaofeng CHEN

《能源前沿（英文）》 2015年 第9卷 第3期   页码 335-342 doi: 10.1007/s11708-015-0365-7

摘要： Based on energy conservation equation and Darcy’s law, a model of beach well infiltration intake system applied in a seawater source heat pump system was established. The model consists of the seawater seepage and the heat transfer process. A porous medium model in a software named FLUENT was applied to simulate the seepage and the heat transfer process. This model was also validated by field experiment conducted on the seashore in Tianjin, China. The maximum relative error between simulation results and experimental results was 2.1% (less than 5%), which was acceptable in engineering application. The porosity and coefficient of thermal conductivity of the aquifer soil were determined to be 0.49 W/(m·K) and 1.46 W/(m·K), respectively in the simulation. In addition, the influencing factors of pumping water of beach well were also analyzed. The pumping water was found to increase when the distance between the beach well and the impervious boundary becomes longer, when the distance between the beach well and the supplying water source shortens, when the diameter of the beach well enlarges, and the drawdown enlarges.

关键词： water pumping analysis     experimental validation     infiltration intake system     seawater source heat pump    

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Optimal Timing and Recycling Operation Mode for Electro-Mechanical Products Active Remanufacturing

Wang Gao,Tao Li,Shi-tong Peng,Liang Wang,Hong-chao Zhang

《工程管理前沿（英文）》 2016年 第3卷 第2期   页码 115-122 doi: 10.15302/J-FEM-2016019

摘要： The uncertainties of remanufactured products in multi-life cycle service, such as injury and restoration process route, are comprehensively analyzed in the present study from perspectives of cost and the environment. Based on life cycle assessment method and the life cycle cost analysis, the optimal timing model of active remanufacturing for electro-mechanical products is established considering these uncertainties. In addition, regarding the active remanufacturing as its guidance, this study explores the economic efficiency and corresponding operation mode of electro-mechanical products when recycling in the optimal timing. To validate the optimal timing model for electro-mechanical products active remanufacturing, a specific type of product is taken as a case study with mathematical statistics method and Monte Carlo simulation.

关键词： electro-mechanical products     active remanufacturing     optimal timing     reverse logistics     recycling mode    

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Novel piezoelectric pump with “E”-shaped valve found from sub-experiments

Jianhui ZHANG, Jun HUANG, Xiaoqi HU, Qixiao XI,

《机械工程前沿（英文）》 2010年 第5卷 第2期   页码 212-218 doi: 10.1007/s11465-010-0009-x

摘要： Increasing the driving frequency of a piezoelectric vibrator can resolve the bottleneck of low flow in a valve piezoelectric pump. However, a piezoelectric pump of a traditional valve body presents the hysteretic nature of the valve, and macroscopic performance is up-frequency to flow-sharply. This research is to settle the bottleneck mentioned above. First, through the sub-experiment on various parameters of the plate valve of a piezoelectric pump, the reasons why a valve body itself can influence “up-frequency to flow-sharply”, which causes the hysteretic nature of the valve, were discovered. Second, an “E”-shaped valve and piezoelectric pump with an “E”-shaped valve (PPEV) were invented. Finally, the efficiency of PPEV has been proved helpful to reduce hysteretic nature in experiments. Under the similar conditions, compared with traditional pumps, the driving frequency of novel PPEV can be more than 10 times high, and the flow rate also can be several times high.

关键词： piezoelectricity     valve     pump     experiment     “     E”     -shaped valve    

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Liquid metal printing opening the way for energy conservation in semiconductor manufacturing industry

《能源前沿（英文）》 2022年 第16卷 第4期   页码 542-547 doi: 10.1007/s11708-022-0834-8

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Optimization design of anti-seismic engineering measures for intake tower based on non-dominated sorting

《结构与土木工程前沿（英文）》   页码 1428-1441 doi: 10.1007/s11709-023-0998-2

摘要： High-rise intake towers in high-intensity seismic areas are prone to structural safety problems under vibration. Therefore, effective and low-cost anti-seismic engineering measures must be designed for protection. An intake tower in northwest China was considered the research object, and its natural vibration characteristics and dynamic response were first analyzed using the mode decomposition response spectrum method based on a three-dimensional finite element model. The non-dominated sorting genetic algorithm-II (NSGA-II) was adopted to optimize the anti-seismic scheme combination by comprehensively considering the dynamic tower response and variable project cost. Finally, the rationality of the original intake tower antiseismic design scheme was evaluated according to the obtained optimal solution set, and recommendations for improvement were proposed. The method adopted in this study may provide significant references for designing anti-seismic measures for high-rise structures such as intake towers located in high-intensity earthquake areas.

关键词： intake tower     NSGA-II     mode decomposition response spectrum method     anti-seismic engineering measures     optimization design     variable project cost    

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Impacts of opening baffle of city road tunnels on natural ventilation performance

Weixiao YANG, Jincheng XING, Jianxing LI, Jihong LING, Haixian HAO, Zhiqiang YAN

《结构与土木工程前沿（英文）》 2013年 第7卷 第1期   页码 55-61 doi: 10.1007/s11709-013-0194-x

摘要： Based on the opening baffle mode for natural ventilation of city road tunnels, this paper studies the impacts of opening baffle on natural ventilation performance by verifying numerical simulation through model tests. By analyzing the impacts of installation angle, dimension, location, and quantity of opening baffle on ventilation performance, the paper reached the conclusions as follows: 1) When installation angle is larger than 45° and tunnel ventilation is well operated, the baffle exhaust could increase by at least 30% compared to when there is no baffle. 2) The baffle reaches its optimal performance when the length of the baffle is equal to the width of the city road tunnels. 3) Baffle exhaust could increase by 30% when it is installed in the downstream of openings. 4) The performance of a single baffle is better than that of multiple baffles.

关键词： city road tunnel     numerical simulation     baffle     top opening     natural ventilation    

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Assessment on contaminations in sediments of an intake and the inflow canals in Taihu Lake, China

Xiaolong WANG,Shiming DING,Qi ZHANG,Weiping HU

《环境科学与工程前沿（英文）》 2015年 第9卷 第4期   页码 665-674 doi: 10.1007/s11783-014-0701-x

摘要： As the second largest freshwater lake in China, Taihu Lake provides water supply to approximately 32 million inhabitants around the lake. However, dramatically increased pollution has threatened the safety of drinking water supply in recent years. In the present study, we investigated the contaminations of nutrients and heavy metals in the sediments of an intake and inflow canals in Gonghu Bay, Taihu Lake. Moreover, we also examined the impact of human activities on spatial distribution characteristics of contaminations. Our results showed that the intake presented relatively lower concentrations of phosphorus and nitrogen compared with inflow canals. However, the concentrations of Cr, Ni, Cu, Zn and Pb in the sediments of the intake exceeded the lowest effect level (LEL) values, indicating a potential risk to drinking water resource. In addition, the concentrations of Ni in the sediments of Tianji Canal and Jinshu Canal exceeded the severe effect level (SEL) value. More importantly, the concentrations of Cu in the sediments of Tianji Canal exceeded three times of the SEL value. Multivariate statistical analysis confirmed that the domestic sewage primarily contributed to the nutrient accumulation, and the leakage of electronic trash dominated the enrichment of metals in the sediments. Taken together, more effort should be made to ensure the security of water resources in Taihu Lake, especially for the treatment of domestic sewage and industrial wastewater.

关键词： drinking water resource     nutrients     heavy metals     sediments     Taihu Lake    

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Nonlinear sealing force of a seawater balance valve used in an 11000-meter manned submersible

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0726-y

摘要： Balance valve is a core component of the 11000-meter manned submersible “struggle,” and its sealing performance is crucial and challenging when the maximum pressure difference is 118 MPa. The increasing sealing force improves the sealing performance and increases the system’s energy consumption at the same time. A hybrid analytical–numerical–experimental (ANE) model is proposed to obtain the minimum sealing force, ensuring no leakage at the valve port and reducing energy consumption as much as possible. The effects of roundness error, environmental pressure, and materials on the minimum sealing force are considered in the ANE model. The basic form of minimum sealing force equations is established, and the remaining unknown coefficients of the equations are obtained by the finite element method (FEM). The accuracy of the equation is evaluated by comparing the independent FEM data to the equation data. Results of the comparison show good agreement, and the difference between the independent FEM data and equation data is within 3% when the environmental pressure is 0–118 MPa. Finally, the minimum sealing force equation is applied in a balance valve to be experimented using a deep-sea simulation device. The balance valve designed through the minimum sealing force equation is leak-free in the experiment. Thus, the minimum sealing force equation is suitable for the ultrahigh pressure balance valve and has guiding significance for evaluating the sealing performance of ultrahigh pressure balance valves.

关键词： seawater balance valve     sealing performance     hybrid ANE model     FEM     minimum sealing force equation    

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Artificial bee colony optimization for economic dispatch with valve point effect

Yacine LABBI,Djilani Ben ATTOUS,Belkacem MAHDAD

《能源前沿（英文）》 2014年 第8卷 第4期   页码 449-458 doi: 10.1007/s11708-014-0316-8

摘要： In recent years, various heuristic optimization methods have been proposed to solve economic dispatch (ED) problem in power systems. This paper presents the well-known power system ED problem solution considering valve-point effect by a new optimization algorithm called artificial bee colony (ABC). The proposed approach has been applied to various test systems with incremental fuel cost function, taking into account the valve-point effects. The results show that the proposed approach is efficient and robust when compared with other optimization algorithms reported in literature.

关键词： artificial bee colony (ABC) algorithm     economic dispatch (ED)     valve-point effect     optimization    

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Development of a novel two-stage proportional valve with a pilot digital flow distribution

Qiang GAO, Yuchuan ZHU, Changwen WU, Yulei JIANG

《机械工程前沿（英文）》 2021年 第16卷 第2期   页码 420-434 doi: 10.1007/s11465-020-0622-2

摘要： Pilot two-stage proportional valves are widely used in high-power hydraulic systems. For the purpose of improving the dynamic performance, reliability, and digitization of the traditional proportional valve, a novel two-stage proportional valve with a pilot digital flow distribution is proposed from the viewpoint of the dual nozzle-flapper valve’s working principle. In particular, the dual nozzle-flapper is decoupled by two high-speed on/off valves (HSVs). First, the working principle and mathematical model of the proposed valve are determined. Then, the influences of the control parameters (duty cycle and switching frequency) and structural parameters (fixed orifice’s diameter and main valve’s spring) on the main valve’s motion are analyzed on the basis of theory, simulation, and experiment. In addition, in optimizing the value of the fixed orifice’s diameter, a new design criterion that considers the maximum pressure sensitivity, flow controllability, and flow linearization is proposed to improve the balance between the effective displacement and the displacement fluctuation of the main valve. The new scheme is verified by simulations and experiments. Experimental results of the closed-loop displacement tracking have demonstrated that the delay time of the main valve is always within 3.5 ms under different working conditions, and the tracking error can be significantly reduced using the higher switching frequency. The amplitude–frequency experiments indicate that a ‒3 dB-frequency of the proposed valve can reach 9.5 Hz in the case of±50% full scale and 15 Hz in the case of 0%–50% full scale. The values can be further improved by increasing the flow rate of the pilot HSV.

关键词： two-stage proportional valve     digital flow distribution     high-speed on/off valve     position tracking characteristic     dynamic performance    

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Right coronary occlusion following transcatheter aortic valve implantation: two case reports

null

《医学前沿（英文）》 2016年 第10卷 第3期   页码 351-355 doi: 10.1007/s11684-016-0465-8

摘要：

This paper discusses two male patients with severe aortic stenosis, whose right coronary arteries (RCA) were completely occluded during transcatheter aortic valve implantation (TAVI), leading to fatal hemodynamic disorder. Occlusions of RCA complicated by TAVI are rare. In addition, emergency cardiopulmonary bypass (CPB) played a critical role in rescuing our second patient. Both patients were admitted for “severe aortic stenosis,” and TAVIs were performed. The first patient’s blood pressure immediately dropped to 70/40 mmHg after the balloon expansion and did not increase much after the administration of aramine or fluid therapy. He did not receive emergency surgery and died after 1.5 h of resuscitation. The second patient’s blood pressure fluctuated greatly for several minutes after the valve implantation, ranging from 170/100 mmHg to 60/40 mmHg. Angiography revealed a total occlusion of RCA. Thoracic surgery with CPB was performed, and the patient survived.

关键词： aortic stenosis     transcatheter aortic valve implantation     right coronary occlusion     cardiac group    

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improving left ventricular remodelling and clinical outcome following surgical and trans-catheter aortic valve

《医学前沿（英文）》 2021年 第15卷 第3期   页码 416-437 doi: 10.1007/s11684-021-0852-7

摘要： Over the last half century, surgical aortic valve replacement (SAVR) has evolved to offer a durable and efficient valve haemodynamically, with low procedural complications that allows favourable remodelling of left ventricular (LV) structure and function. The latter has become more challenging among elderly patients, particularly following trans-catheter aortic valve implantation (TAVI). Precise understanding of myocardial adaptation to pressure and volume overloading and its responses to valve surgery requires comprehensive assessments from aortic valve energy loss, valvular-vascular impedance to myocardial activation, force-velocity relationship, and myocardial strain. LV hypertrophy and myocardial fibrosis remains as the structural and morphological focus in this endeavour. Early intervention in asymptomatic aortic stenosis or regurgitation along with individualised management of hypertension and atrial fibrillation is likely to improve patient outcome. Physiological pacing via the His-Purkinje system for conduction abnormalities, further reduction in para-valvular aortic regurgitation along with therapy of angiotensin receptor blockade will improve patient outcome by facilitating hypertrophy regression, LV coordinate contraction, and global vascular function. TAVI leaflet thromboses require anticoagulation while impaired access to coronary ostia risks future TAVI-in-TAVI or coronary interventions. Until comparable long-term durability and the resolution of TAVI related complications become available, SAVR remains the first choice for lower risk younger patients.

关键词： surgical aortic valve replacement     trans-catheter aortic valve implantation     left ventricular hypertrophy and fibrosis     myocardial force-velocity relationship     His-Purkinje pacing     renin-angiotensin system inhibitors     coronary access impairment    

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标题 作者 时间 类型 操作

Effects of fuel combination and IVO timing on combustion and emissions of a dual-fuel HCCI combustion

Xin LIANG, Jianyong ZHANG, Zhongzhao LI, Jiabo ZHANG, Zhen HUANG, Dong HAN

期刊论文

一种混合电磁气门驱动机构设计

Jawad ASLAM, Xing-hu LI, Faira Kanwal JANJUA

期刊论文

J-shaped association between dietary zinc intake and new-onset hypertension: a nationwide cohort study

期刊论文

Water pumping analysis and experimental validation of beach well infiltration intake system in a seawater

Huan ZHANG,Shu LIU,Xuejing ZHENG,Gaofeng CHEN

期刊论文

Optimal Timing and Recycling Operation Mode for Electro-Mechanical Products Active Remanufacturing

Wang Gao,Tao Li,Shi-tong Peng,Liang Wang,Hong-chao Zhang

期刊论文

Novel piezoelectric pump with “E”-shaped valve found from sub-experiments

Jianhui ZHANG, Jun HUANG, Xiaoqi HU, Qixiao XI,

期刊论文

Liquid metal printing opening the way for energy conservation in semiconductor manufacturing industry

期刊论文

Optimization design of anti-seismic engineering measures for intake tower based on non-dominated sorting

期刊论文

Impacts of opening baffle of city road tunnels on natural ventilation performance

Weixiao YANG, Jincheng XING, Jianxing LI, Jihong LING, Haixian HAO, Zhiqiang YAN

期刊论文

Assessment on contaminations in sediments of an intake and the inflow canals in Taihu Lake, China

Xiaolong WANG,Shiming DING,Qi ZHANG,Weiping HU

期刊论文

Nonlinear sealing force of a seawater balance valve used in an 11000-meter manned submersible

期刊论文

Artificial bee colony optimization for economic dispatch with valve point effect

Yacine LABBI,Djilani Ben ATTOUS,Belkacem MAHDAD

期刊论文

Development of a novel two-stage proportional valve with a pilot digital flow distribution

Qiang GAO, Yuchuan ZHU, Changwen WU, Yulei JIANG

期刊论文

Right coronary occlusion following transcatheter aortic valve implantation: two case reports

null

期刊论文

improving left ventricular remodelling and clinical outcome following surgical and trans-catheter aortic valve

期刊论文