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Experimental study of stratified lean burn characteristics on a dual injection gasoline engine

Chun XIA, Tingyu ZHAO, Junhua FANG, Lei ZHU, Zhen HUANG

《能源前沿（英文）》 2022年 第16卷 第6期   页码 900-915 doi: 10.1007/s11708-021-0812-6

摘要： Due to increasingly stringent fuel consumption and emission regulation, improving thermal efficiency and reducing particulate matter emissions are two main issues for next generation gasoline engine. Lean burn mode could greatly reduce pumping loss and decrease the fuel consumption of gasoline engines, although the burning rate is decreased by higher diluted intake air. In this study, dual injection stratified combustion mode is used to accelerate the burning rate of lean burn by increasing the fuel concentration near the spark plug. The effects of engine control parameters such as the excess air coefficient (Lambda), direct injection (DI) ratio, spark interval with DI, and DI timing on combustion, fuel consumption, gaseous emissions, and particulate emissions of a dual injection gasoline engine are studied. It is shown that the lean burn limit can be extended to Lambda= 1.8 with a low compression ratio of 10, while the fuel consumption can be obviously improved at Lambda= 1.4. There exists a spark window for dual injection stratified lean burn mode, in which the spark timing has a weak effect on combustion. With optimization of the control parameters, the brake specific fuel consumption (BSFC) decreases 9.05% more than that of original stoichiometric combustion with DI as 2 bar brake mean effective pressure (BMEP) at a 2000 r/min engine speed. The NOx emissions before three-way catalyst (TWC) are 71.31% lower than that of the original engine while the particle number (PN) is 81.45% lower than the original engine. The dual injection stratified lean burn has a wide range of applications which can effectively reduce fuel consumption and particulate emissions. The BSFC reduction rate is higher than 5% and the PN reduction rate is more than 50% with the speed lower than 2400 r/min and the load lower than 5 bar.

关键词： dual injection     stratified lean burn     gasoline engine     particulate matter emission     combustion analysis    

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Laboratory study on high-temperature adsorption of HCl by dry-injection of Ca(OH)

Junjun TAN,Guohua YANG,Jingqiao MAO,Huichao DAI

《环境科学与工程前沿（英文）》 2014年 第8卷 第6期   页码 863-870 doi: 10.1007/s11783-013-0618-9

摘要： Combustion-generated hydrogen chloride (HCl) is considered to be a very hazardous acid gaseous pollutant. This paper presents a laboratory study on the dry adsorption of HCl. The experiments were conducted in a dual-layer granular bed filter, at gas temperatures of 500°C–700°C and (Ca)/ (Cl)molar ratios of 1.0–5.0 using the silver nitrate titration method by dry adsorbent powders Ca(OH) . Mainly, the adsorption efficiency of HCl and utilization efficiency of Calcium were studied, by varying relevant factors including (Ca)/ (Cl), temperature, feeding method, water vapor and CO . With a relatively higher HCl concentration of 1000 ppm, the experimental results revealed that 600°C may be the optimum temperature for HCl adsorption when optimum (Ca)/ (Cl) was 2.5 in our tests. The results also demonstrated that the feeding at a constant pressure was more effective, and the HCl adsorption efficiency could rapidly reach over 90% with (Ca)/ (Cl) = 2.5 at 600°C. Furthermore, the HCl adsorption efficiency was found to be slightly promoted by water vapor, while could be impeded by CO , and the utilization efficiency of calcium could be up to 74.4% without CO , while was only 36.8% with CO when (Ca)/ (Cl) was 2.5 at 600°C.

关键词： acid gas HCl     Ca(OH)2     dry adsorption     high temperature     dual-layer granular bed filter    

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喷射策略对低负荷下天然气——柴油双燃料预混压燃燃烧的影响研究 Article

Hyunwook Park, Euijoon Shim, Choongsik Bae

《工程（英文）》 2019年 第5卷 第3期   页码 548-557 doi: 10.1016/j.eng.2019.03.005

摘要：

双燃料预混压燃（dual-fuel premixed charge compression ignition, DF-PCCI）燃烧因其氮氧化物（NOx）和颗粒物

关键词： 双燃料     反应可控压燃     预混压燃     天然气     喷射策略     废气再循环    

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Three-dimensional numerical simulation for plastic injection-compression molding

Yun ZHANG, Wenjie YU, Junjie LIANG, Jianlin LANG, Dequn LI

《机械工程前沿（英文）》 2018年 第13卷 第1期   页码 74-84 doi: 10.1007/s11465-018-0490-1

摘要：

Compared with conventional injection molding, injection-compression molding can mold optical parts with higher precision and lower flow residual stress. However, the melt flow process in a closed cavity becomes more complex because of the moving cavity boundary during compression and the nonlinear problems caused by non-Newtonian polymer melt. In this study, a 3D simulation method was developed for injection-compression molding. In this method, arbitrary Lagrangian-Eulerian was introduced to model the moving-boundary flow problem in the compression stage. The non-Newtonian characteristics and compressibility of the polymer melt were considered. The melt flow and pressure distribution in the cavity were investigated by using the proposed simulation method and compared with those of injection molding. Results reveal that the fountain flow effect becomes significant when the cavity thickness increases during compression. The back flow also plays an important role in the flow pattern and redistribution of cavity pressure. The discrepancy in pressures at different points along the flow path is complicated rather than monotonically decreased in injection molding.

关键词： injection-compression molding     simulation     injection molding     melt flow     cavity pressure    

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density measurement for plastic injection molding via ultrasonic technology

《机械工程前沿（英文）》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0714-2

摘要： Density variation during the injection molding process directly reflects the state of plastic melt and contains valuable information for process monitoring and optimization. Therefore, in-situ density measurement is of great interest and has significant application value. The existing methods, such as pressure−volume−temperature (PVT) method, have the shortages of time-delay and high cost of sensors. This study is the first to propose an in-situ density measurement method using ultrasonic technology. The analyses of the time-domain and frequency-domain signals are combined in the proposed method. The ultrasonic velocity is obtained from the time-domain signals, and the acoustic impedance is computed through a full-spectral analysis of the frequency-domain signals. Experiments with different process conditions are conducted, including different melt temperature, injection speed, material, and mold structure. Results show that the proposed method has good agreement with the PVT method. The proposed method has the advantages of in-situ measurement, non-destructive, high accuracy, low cost, and is of great application value for the injection molding industry.

关键词： ultrasonic measurement     melt density     in-situ measurement     injection molding    

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凝析气藏的经济开采模式

刘廷元

《中国工程科学》 2001年 第3卷 第3期   页码 85-91

摘要：

液态凝析油是凝析气藏的重要产品，它的开采应该是有效而经济的。介绍了国外近20 a来在凝析气藏开采技术领域的各种经济模式，包括回注φd=75%干气、自流回注、注N2、注水、水气交替注和注CO2等开采模式。研究结果表明，这些开采模式同传统的降压开采方法相比，能够有效地适应地面-地下的各种复杂情况。

关键词： 凝析气藏     开采模式     注气     注氮     注水     注二氧化碳     经济    

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Trend prediction technology of condition maintenance for large water injection units

Xiaoli XU, Sanpeng DENG

《机械工程前沿（英文）》 2010年 第5卷 第2期   页码 171-175 doi: 10.1007/s11465-009-0091-0

摘要： Trend prediction technology is the key technology to achieve condition-based maintenance of mechanical equipment. Large-sized water injection units are key equipment in oilfields. The traditional preventive maintenance is not economical and cannot completely avoid vicious accidents. To ensure the normal operation of units and save maintenance costs, trend prediction technology is studied to achieve condition-based maintenance for water injection units. The main methods of the technology are given, the trend prediction method based on neural network is put forward, and the expert system based on the knowledge is developed. The industrial site verification shows that the proposed trend prediction technology can reflect the operating condition trend change of the water injection units and provide technical means to achieve condition-based predictive maintenance.

关键词： water injection units     condition-based maintenance     trend prediction    

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Intelligent methods for the process parameter determination of plastic injection molding

Huang GAO, Yun ZHANG, Xundao ZHOU, Dequn LI

《机械工程前沿（英文）》 2018年 第13卷 第1期   页码 85-95 doi: 10.1007/s11465-018-0491-0

摘要：

Injection molding is one of the most widely used material processing methods in producing plastic products with complex geometries and high precision. The determination of process parameters is important in obtaining qualified products and maintaining product quality. This article reviews the recent studies and developments of the intelligent methods applied in the process parameter determination of injection molding. These intelligent methods are classified into three categories: Case-based reasoning methods, expert system-based methods, and data fitting and optimization methods. A framework of process parameter determination is proposed after comprehensive discussions. Finally, the conclusions and future research topics are discussed.

关键词： injection molding     intelligent methods     process parameters     optimization    

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methodology for regulating fuel stratification and improving fuel economy of GCI mode via double main-injection

《能源前沿（英文）》 2023年 第17卷 第5期   页码 678-691 doi: 10.1007/s11708-022-0859-z

摘要： Gasoline compression ignition (GCI) combustion faces problems such as high maximum pressure rise rate (MPRR) and combustion deterioration at high loads. This paper aims to improve the engine performance of the GCI mode by regulating concentration stratification and promoting fuel-gas mixing by utilizing the double main-injection (DMI) strategy. Two direct injectors simultaneously injected gasoline with an octane number of 82.7 to investigate the energy ratio between the two main-injection and exhaust gas recirculation (EGR) on combustion and emissions. High-load experiments were conducted using the DMI strategy and compared with the single main-injection (SMI) strategy and conventional diesel combustion. The results indicate that the DMI strategy have a great potential to reduce the MPRR and improve the fuel economy of the GCI mode. At a 10 bar indicated mean effective pressure, increasing the main-injection-2 ratio (Rm-2) shortens the injection duration and increases the mean mixing time. Optimized Rm-2 could moderate the trade-off between the MPRR and the indicated specific fuel consumption with both reductions. An appropriate EGR should be adopted considering combustion and emissions. The DMI strategy achieves a highly efficient and stable combustion at high loads, with an indicated thermal efficiency (ITE) greater than 48%, CO and THC emissions at low levels, and MPRR within a reasonable range. Compared with the SMI strategy, the maximum improvement of the ITE is 1.5%, and the maximum reduction of MPRR is 1.5 bar/°CA.

关键词： gasoline compression ignition     injection strategy     fuel stratification     high efficiency     high load    

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CO, N, and CO/N mixed gas injection for enhanced shale gas recovery and CO geological storage

《能源前沿（英文）》 2023年 第17卷 第3期   页码 428-445 doi: 10.1007/s11708-023-0865-9

摘要： In this work, using fractured shale cores, isothermal adsorption experiments and core flooding tests were conducted to investigate the performance of injecting different gases to enhance shale gas recovery and CO2 geological storage efficiency under real reservoir conditions. The adsorption process of shale to different gases was in agreement with the extended-Langmuir model, and the adsorption capacity of CO2 was the largest, followed by CH4, and that of N2 was the smallest of the three pure gases. In addition, when the CO2 concentration in the mixed gas exceeded 50%, the adsorption capacity of the mixed gas was greater than that of CH4, and had a strong competitive adsorption effect. For the core flooding tests, pure gas injection showed that the breakthrough time of CO2 was longer than that of N2, and the CH4 recovery factor at the breakthrough time (RCH4) was also higher than that of N2. The RCH4 of CO2 gas injection was approximately 44.09%, while the RCH4 of N2 was only 31.63%. For CO2/N2 mixed gas injection, with the increase of CO2 concentration, the RCH4 increased, and the RCH4 for mixed gas CO2/N2 = 8:2 was close to that of pure CO2, about 40.24%. Moreover, the breakthrough time of N2 in mixed gas was not much different from that when pure N2 was injected, while the breakthrough time of CO2 was prolonged, which indicated that with the increase of N2 concentration in the mixed gas, the breakthrough time of CO2 could be extended. Furthermore, an abnormal surge of N2 concentration in the produced gas was observed after N2 breakthrough. In regards to CO2 storage efficiency (Sstorage-CO2), as the CO2 concentration increased, Sstorage-CO2 also increased. The Sstorage-CO2 of the pure CO2 gas injection was about 35.96%, while for mixed gas CO2/N2 = 8:2, Sstorage-CO2 was about 32.28%.

关键词： shale gas     gas injection     competitive adsorption     enhanced shale gas recovery     CO2 geological storage    

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A novel task-oriented framework for dual-arm robotic assembly task

《机械工程前沿（英文）》 2021年 第16卷 第3期   页码 528-545 doi: 10.1007/s11465-021-0638-2

摘要： In industrial manufacturing, the deployment of dual-arm robots in assembly tasks has become a trend. However, making the dual-arm robots more intelligent in such applications is still an open, challenging issue. This paper proposes a novel framework that combines task-oriented motion planning with visual perception to facilitate robot deployment from perception to execution and finish assembly problems by using dual-arm robots. In this framework, visual perception is first employed to track the effects of the robot behaviors and observe states of the workpieces, where the performance of tasks can be abstracted as a high-level state for intelligent reasoning. The assembly task and manipulation sequences can be obtained by analyzing and reasoning the state transition trajectory of the environment as well as the workpieces. Next, the corresponding assembly manipulation can be generated and parameterized according to the differences between adjacent states by combining with the prebuilt knowledge of the scenarios. Experiments are set up with a dual-arm robotic system (ABB YuMi and an RGB-D camera) to validate the proposed framework. Experimental results demonstrate the effectiveness of the proposed framework and the promising value of its practical application.

关键词： dual-arm assembly     AI reasoning     intelligent system     task-oriented motion planning     visual perception    

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Microcellular injection molding process for producing lightweight thermoplastic polyurethane with customizable

Thomas ELLINGHAM, Hrishikesh KHARBAS, Mihai MANITIU, Guenter SCHOLZ, Lih-Sheng TURNG

《机械工程前沿（英文）》 2018年 第13卷 第1期   页码 96-106 doi: 10.1007/s11465-018-0498-6

摘要：

A three-stage molding process involving microcellular injection molding with core retraction and an “out-of-mold” expansion was developed to manufacture thermoplastic polyurethane into lightweight foams of varying local densities, microstructures, and mechanical properties in the same microcellular injection molded part. Two stages of cavity expansion through sequential core retractions and a third expansion in a separate mold at an elevated temperature were carried out. The densities varied from 0.25 to 0.42 g/cm3 (77% to 62% weight reduction). The mechanical properties varied as well. Cyclic compressive strengths and hysteresis loss ratios, together with the microstructures, were characterized and reported.

关键词： thermoplastic polyurethane     microcellular injection molding     cavity expansion     compressive strength     hysteresis loss ratio    

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气辅注塑成型注气压力的模糊神经网络控制研究

欧长劲

《中国工程科学》 2007年 第9卷 第5期   页码 27-32

摘要：

针对气辅注塑成形的注气压力精确控制要求，设计了具有５层结构的模糊神经网络控制器和控制算法，利用神经网络的学习能力实现对模糊逻辑规则的优化，改善了系统的适应性。对系统３段压力控制的仿真 分析，验证了模糊神经网络控制模型的可行性，控制效果良好。

关键词： 气体辅助注射成型     模糊神经网络     注气压力控制    

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Combustion characteristics of a direct-injection diesel engine fueled with Fischer-Tropsch diesel

HUANG Yongcheng, ZHOU Longbao, PAN Keyu

《能源前沿（英文）》 2007年 第1卷 第2期   页码 239-244 doi: 10.1007/s11708-007-0033-7

摘要： Fischer-Tropsch (F-T) diesel fuel is characterized by a high cetane number, a near-zero sulphur content and a very low aromatic level. On the basis of the recorded incylinder pressures and injector needle lifts, the combustion characteristics of an unmodified single-cylinder direct-injection diesel engine operating on F-T diesel fuel are analyzed and compared with those of conventional diesel fuel operation. The results show that F-T diesel fuel exhibits a slightly longer injection delay and injection duration, an average of 18.7% shorter ignition delay, and a comparable total combustion duration when compared to those of conventional diesel fuel. Meanwhile, F-T diesel fuel displays an average of 26.8% lower peak value of premixed burning rate and a higher peak value of diffusive burning rate. In addition, the F-T diesel engine has a slightly lower peak combustion pressure, a far lower rate of pressure rise, and a lower mechanical load and combustion noise than the conventional diesel engine. The brake specific fuel consumption is lower and the effective thermal efficiency is higher for F-T diesel fuel operation.
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Preventive effect of Shenkang injection against high glucose-induced senescence of renal tubular cells

Biqiong Fu, Jie Yang, Jia Chen, Lirong Lin, Kehong Chen, Weiwei Zhang, Jianguo Zhang, Yani He

《医学前沿（英文）》 2019年 第13卷 第2期   页码 267-276 doi: 10.1007/s11684-017-0586-8

摘要： Shenkang injection (SKI) is a classic prescription composed of , rhubarb, , and . This treatment was approved by the State Food and Drug Administration of China in 1999 for treatment of chronic kidney diseases based on good efficacy and safety. This study aimed to investigate the protective effect of SKI against high glucose (HG)-induced renal tubular cell senescence and its underlying mechanism. Primary renal proximal tubule epithelial cells were cultured in (1) control medium (control group), medium containing 5 mmol/L glucose; (2) mannitol medium (mannitol group), medium containing 5 mmol/L glucose, and 25 mmol/L mannitol; (3) HG medium (HG group) containing 30 mmol/L glucose; (4) SKI treatment at high (200 mg/L), medium (100 mg/L), or low (50 mg/L) concentration in HG medium (HG+ SKI group); or (5) 200 mg/L SKI treatment in control medium (control+ SKI group) for 72 h. HG-induced senescent cells showed the emergence of senescence associated heterochromatin foci, up-regulation of P16 and cyclin D1, increased senescence-associated β-galactosidase activity, and elevated expression of membrane decoy receptor 2. SKI treatment potently prevented these changes in a dose-independent manner. SKI treatment prevented HG-induced up-regulation of pro-senescence molecule mammalian target of rapamycin and p66Shc and down-regulation of anti-senescence molecules klotho, sirt1, and peroxisome proliferator-activated receptor- in renal tubular epithelial cells. SKI may be a novel strategy for protecting against HG-induced renal tubular cell senescence in treatment of diabetic nephropathy.

关键词： Shenkang injection     senescence     renal tubular epithelial cells     diabetic nephropathy    

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标题 作者 时间 类型 操作

Experimental study of stratified lean burn characteristics on a dual injection gasoline engine

Chun XIA, Tingyu ZHAO, Junhua FANG, Lei ZHU, Zhen HUANG

期刊论文

Laboratory study on high-temperature adsorption of HCl by dry-injection of Ca(OH)

Junjun TAN,Guohua YANG,Jingqiao MAO,Huichao DAI

期刊论文

喷射策略对低负荷下天然气——柴油双燃料预混压燃燃烧的影响研究

Hyunwook Park, Euijoon Shim, Choongsik Bae

期刊论文

Three-dimensional numerical simulation for plastic injection-compression molding

Yun ZHANG, Wenjie YU, Junjie LIANG, Jianlin LANG, Dequn LI

期刊论文

density measurement for plastic injection molding via ultrasonic technology

期刊论文

凝析气藏的经济开采模式

刘廷元

期刊论文

Trend prediction technology of condition maintenance for large water injection units

Xiaoli XU, Sanpeng DENG

期刊论文

Intelligent methods for the process parameter determination of plastic injection molding

Huang GAO, Yun ZHANG, Xundao ZHOU, Dequn LI

期刊论文

methodology for regulating fuel stratification and improving fuel economy of GCI mode via double main-injection

期刊论文

CO, N, and CO/N mixed gas injection for enhanced shale gas recovery and CO geological storage

期刊论文

A novel task-oriented framework for dual-arm robotic assembly task

期刊论文

Microcellular injection molding process for producing lightweight thermoplastic polyurethane with customizable

Thomas ELLINGHAM, Hrishikesh KHARBAS, Mihai MANITIU, Guenter SCHOLZ, Lih-Sheng TURNG

期刊论文

气辅注塑成型注气压力的模糊神经网络控制研究

欧长劲

期刊论文

Combustion characteristics of a direct-injection diesel engine fueled with Fischer-Tropsch diesel

HUANG Yongcheng, ZHOU Longbao, PAN Keyu

期刊论文

Preventive effect of Shenkang injection against high glucose-induced senescence of renal tubular cells

Biqiong Fu, Jie Yang, Jia Chen, Lirong Lin, Kehong Chen, Weiwei Zhang, Jianguo Zhang, Yani He

期刊论文