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2018 2

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“上限” 1

二冲程发动机 1

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An experimental study of a single-piston free piston linear generator

Jin XIAO, Yingdong CHENG, Jinlong WANG, Chengwei ZHU, Zhen HUANG

《能源前沿（英文）》 2022年第16卷第6期页码 916-930 doi: 10.1007/s11708-022-0838-4

摘要： Free piston linear generator (FPLG) is a promising range extender for the electrical vehicle with unparallel advantages, such as compact structure, higher system efficiency, and reduced maintenance cost. However, due to the lack of the mechanic crankshaft, the related piston motion control is a challenge for the FPLG which causes problems such as misfire and crash and limits its widespread commercialization. Aimed at resolving the problems as misfire, a single-piston FPLG prototype has been designed and manufactured at Shanghai Jiao Tong University (SJTU). In this paper, the development process and experimental validation of the related control strategies were detailed. From the experimental studies, significant misfires were observed at first, while the FPLG operated in natural-aspiration conditions. The root cause of this misfire was then identified as the poor scavenging process, and a compressed air source was leveraged to enhance the related scavenging pressure. Afterward, optimal control parameters, in terms of scavenging pressure, air-fuel equivalence ratio, and ignition position, were then calibrated in this charged-scavenging condition. Eventually, the FPLG prototype has achieved a continuous stable operation of over 1000 cycles with an ignition rate of 100% and a cycle-to-cycle variation of less than 0.8%, produced an indicated power of 2.8 kW with an indicated thermal efficiency of 26% and an electrical power of 2.5 kW with an overall efficiency of 23.2%.

关键词： free piston linear generator (FPLG) charged scavenging engine control misfire stable operation

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Temporal evolution of charged and neutral nanoparticle concentrations during atmospheric new particle

E. Rohan Jayaratne, Buddhi Pushpawela, Lidia Morawska

《环境科学与工程前沿（英文）》 2016年第10卷第5期 doi: 10.1007/s11783-016-0862-x

摘要： Over 100 new particle formation events were studied. In 50 events, charged and neutral particles were not formed at the same time. In 42 of these events the charged particles formed before the neutral particles. Their subsequent growth rates were not determined by the particle charge. The result suggests that ion induced nucleation plays a role in particle formation. Time series of nanoparticle number concentration during new particle formation (NPF) events in the urban environment of Brisbane, Australia, showed that the formation of charged particles often occurred before that of neutral particles. We monitored 241 days during the calendar year 2012 over which NPF events were observed on 108 days. We studied the times at which the charged and neutral particle concentrations in the size range 1.8–3.2 nm reached their peak values and found that they were clearly different in 50 events with the peak neutral particle concentration lagging behind the charged particle concentration during 42 of these events with a mean time lag of 24±12 min. While the charged particles were more likely to form before the neutral particles, once formed, the growth rate of the particles did not depend on their charge. While ion-induced nucleation is not the dominant mechanism of NPF in the atmosphere, our observations suggest that the presence of ions in the atmosphere plays a role that cannot be ignored.

关键词： Charged particles Cluster ions Secondary particles Environmental pollution

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Shear wall layout optimization of tall buildings using Quantum Charged System Search

Siamak TALATAHARI, Mahdi RABIEI

《结构与土木工程前沿（英文）》 2020年第14卷第5期页码 1131-1151 doi: 10.1007/s11709-020-0660-1

摘要： This paper presents a developed meta-heuristic algorithm to optimize the shear walls of tall reinforced concrete buildings. These types of walls are considered as lateral resistant elements. In this paper, Quantum Charged System Search (QCSS) algorithm is presented as a new optimization method and used to improve the convergence capability of the original Charged System Search. The cost of tall building is taken as the objective function. Since the design of the lateral system plays a major role in the performance of the tall buildings, this paper proposes a unique computational technique that, unlike available works, focuses on structural efficiency or architectural design. This technique considers both structural and architectural requirements such as minimum structural costs, torsional effects, flexural and shear resistance, lateral deflection, openings and accessibility. The robustness of the new algorithm is demonstrated by comparing the outcomes of the QCSS with those of its standard algorithm.

关键词： Quantum Charged System Search shear wall layout optimization tall buildings

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Free radical scavenging window of infertile patients with polycystic ovary syndrome: correlation with

null

《医学前沿（英文）》 2017年第11卷第2期页码 247-252 doi: 10.1007/s11684-017-0519-6

摘要：

The activity of free radicals in follicular fluid was related to ovarian responsiveness, in vitro fertilization (IVF), and embryo transfer success rate. However, studies analyzing the relationship between the free radical scavenging capacity and embryo quality of infertile women with polycystic ovarian syndrome (PCOS) were lacking. The aim of this study was to evaluate the relationship between the free radical scavenging window of women with PCOS and their embryo quality. The free radical scavenging capacity of follicular fluid from women with PCOS was determined by a,a-diphenyl-b-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzthiazoline-6-sulphonic acid) assay, superoxide radical, and reactive oxygen species (ROS) assay. In the DPPH and ROS assays, the follicular fluid from grades I and II embryos was significantly higher than the follicular fluid from grades III and IV embryos. The lower control limit of DPPH radical scavenging capacity and upper control limit of ROS level were 13.2% and 109.0 cps, respectively. The calculated lower control limit and upper control limit were further confirmed in the follicular fluid of embryos of all grades. These cut-off values of free radical scavenging activity of follicular fluid could assist embryologists in choosing the development of embryos in PCOS patients undergoing IVF.

关键词： in vitro fertilization PCOS free radical embryo quality

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Ductility loss of hydrogen-charged and releasing 304L steel

Yanfei WANG, Jianming GONG, Yong JIANG, Wenchun JIANG, Wang JIANG

《机械工程前沿（英文）》 2013年第8卷第3期页码 298-304 doi: 10.1007/s11465-013-0265-7

摘要：

The mechanical properties and fracture behavior of 304L austenitic stainless steel after cathodic hydrogen charging and hydrogen spontaneously releasing are investigated by tensile tests. Flat tensile specimens were cathodic hydrogen charged at various current densities. For each density, two specimens were charged at the same condition. When the charging process completed, one specimen was tensile immediately to fracture and the other was aged to release the hydrogen out of it and then was also tensile to fracture. The resulting tensile properties and micrographs of fracture surfaces of these specimens were evaluated and compared. The results show ductility loss occurred in the hydrogen-charged specimens and the loss increased as the current density increasing. After hydrogen releasing, the specimens recovered a certain extent but not all of its original ductility. Scanning electron microscope (SEM) micrographs of fracture surfaces reveal that irreversible damage had developed in the hydrogen-releasing specimens during the releasing process rather than the charging process. This consequence can be ascribed to the high tensile stress caused by non-uniform hydrogen distribution during hydrogen releasing.

关键词： hydrogen embrittlement ductility loss hydrogen releasing control strategy 304L austenitic stainless steel

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Effect of electrokinetic property of charged polyether sulfone membrane on bovine serum albumin fouling

Xiaorong Meng, Shanshan Huo, Lei Wang, Xudong Wang, Yongtao Lv, Weiting Tang, Rui Miao, Danxi Huang

《环境科学与工程前沿（英文）》 2017年第11卷第2期 doi: 10.1007/s11783-017-0907-9

摘要： Negatively charged CMPES and positively charged QAPES membranes were fabricated. Charge modification reduced the adhesion forces between PES UF membranes and BSA. QAPES-BSA / was weaker than that of CMPES-BSA at pH 3 and on the contrary at pH 9. Flux decline rate was positively correlated with the adhesion forces of membrane-BSA. Variation of adhesion was consistent with that of potential absolute values. Negatively charged carboxymethylated polyethersulfone (CMPES) and positively charged quaternized polyethersulfone (QAPES) ultrafiltration (UF) membranes were prepared by bulk chemical modification and non-solvent induced phase separation method. The effects of PES membrane interfacial electrokinetic property on the bovine serum albumin (BSA) membrane fouling behavior were studied with the aid of the membrane-modified colloidal atomic force microscopy (AFM) probe. Electrokinetic test results indicated that the streaming potential (D ) of QAPES membrane was not consistent with its expected value, however, within the pH range of 3–10, the potentials of two charged-modified PES membranes were more stable than the unmodified membrane. When pH value was 3, 4.7 or 9, the interaction behavior between charged PES membrane and BSA showed that there was significant linear correlation between the jump distance of membrane-BSA adhesion force ( ) and the potential absolute value. Charged modification significantly reduced the adhesion of PES membrane-BSA, and the adhesion data was good linear correlated with the flux decline rate in BSA filtration process, especially reflected in the CMPES membrane. The above experimental facts proved that the charged membrane interfacial electric double layer structure and its electrokinetic property had strong ties with the protein membrane fouling behavior.

关键词： Charged PES UF membrane BSA Electrokinetic characterization Adhesion force Jump distance

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Combustion and emission characteristics of a turbo-charged common rail diesel engine fuelled with diesel-biodiesel-DEE

Ni ZHANG, Zuohua HUANG, Xiangang WANG, Bin ZHENG

《能源前沿（英文）》 2011年第5卷第1期页码 104-114 doi: 10.1007/s11708-011-0138-x

摘要： The combustion and emission characteristics of a turbo-charged, common rail diesel engine fuelled with diesel-biodiesel-DEE blends were investigated. The study reports that the brake-specific fuel consumption of diesel-biodiesel-DEE blends increases with increase of oxygenated fuel fractions in the blends. Brake thermal efficiency shows little variation when operating on different diesel-biodiesel-DEE blends. At a low load, the NO emission of the diesel-biodiesel-DEE blends exhibits little variation in comparison with the biodiesel fraction. The NO emission slightly increases with increase in the biodiesel fraction in diesel-biodiesel-DEE blends at medium load. However, the NO emission increases remarkably with increase of the biodiesel fraction at high load. Particle mass concentration decreases significantly with increase of the oxygenated-fuels fraction at all engine speeds and loads; particle number concentration decreases remarkably with increase of the oxygenated-fuels fraction. HC and CO emissions decrease with increasing oxygenated-fuels fraction in these blends.

关键词： Combustion particulate emissions diesel-biodiesel-DEE blend diesel engine

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一种高效的二冲程发动机概念——结合空气混合动力系统的增压直流扫气式直喷汽油（BUSDIG）发动机 Review

王新颜, 赵华

《工程（英文）》 2019年第5卷第3期页码 535-547 doi: 10.1016/j.eng.2019.03.008

摘要：

本研究提出并设计了一种新颖的二冲程增压直流扫气式直喷汽油（BUSDIG）发动机，以实现发动机小型化和低速化，进而提升发动机的性能和效率。本文综述了BUSDIG 发动机的设计和开发过程，并总结了主要的研究成果。为了最大限度地提高发动机的扫气性能，并实现合理的缸内流动以促进燃油/ 空气的混合过程，本研究采用三维（3D）计算流体动力学（CFD）模拟手段系统分析了发动机缸径/ 冲程比（B/S）、扫气道角度和进气道的设计。此外，本研究还系统分析了扫气口和排气门开启型线对扫气过程的影响。为实现最佳的缸内燃油分层，采用经过实验标定的Reize-Diwakar模型开展了缸内喷雾的CFD 模拟，系统分析了不同喷油策略对缸内混合气形成过程的影响。基于优化后的BUSDIG 发动机设计方案，在Ricardo WAVE 软件中构建了对应的一维（1D）发动机计算模型。计算结果表明，采用稀薄燃烧和喷水策略，二冲程BUSDIG发动机的最高有效热效率可达47.2%。在化学计量燃空当量比条件下，BUSDIG 发动机在1600 r∙min^–1 的转速下可实现379 N∙m 的扭矩，在4000 r∙min^–1的转速下可达到112 kW∙L^–1 的功率密度。

关键词：二冲程发动机直流扫气发动机设计发动机模拟扫气性能热效率

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离子分离用电荷Janus结构单价选择性阳离子交换膜 Article

王文广, 张艳秋, 杨晓彬, 孙海翔, 吴亚东, 邵路

《工程（英文）》 2023年第25卷第6期页码 204-213 doi: 10.1016/j.eng.2021.09.020

摘要：

单价选择性阳离子交换膜（M-CEMs）已被广泛应用于环境修复和能量收集等领域，例如，从卤水和海水中提取Na⁺或Li⁺。然而，由于膜结构和材料的限制，M-CEMs存在渗透选择性低的问题。在此，我们提出了一种简单的方法以构建具有电荷Janus结构的新型M-CEMs，该结构由荷正电的均苯三甲酸/聚乙烯亚胺选择层和荷负电的商业阳离子交换膜（CEM）组成。选择性电渗析（SED）分析结果表明，具有电荷Janus结构的M-CEMs可以有效抑制多孔阳离子交换膜中存在的阴离子迁移问题，因而使这种具有电荷Janus结构的M-CEMs具有较高的渗透选择性和总阳离子通量。与最先进的单价选择性阳离子交换膜的分离性能相比，具有电荷Janus结构的M-CEMs对于Na⁺/Mg²⁺的最高渗透选择性可以达到145.77，这超过了目前单价选择性阳离子交换膜性能的“上限”，且对于Li⁺/Mg²⁺也具有优异的渗透选择性（14.11），在离子分离领域具有巨大的应用潜力。这项研究可以为具有电荷Janus结构的M-CEMs的设计提供新的见解，并应用于不同的环境和能源领域。

关键词：单价选择性阳离子交换膜电荷Janus结构选择性电渗析渗透选择性 “上限” 离子分离

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Novel polyethyleneimine/TMC-based nanofiltration membrane prepared on a polydopamine coated substrate

Zhe Yang, Xiaoyu Huang, Jianqiang Wang, Chuyang Y. Tang

《化学科学与工程前沿（英文）》 2018年第12卷第2期页码 273-282 doi: 10.1007/s11705-017-1695-2

摘要： Most commercial NF membranes are negatively charged at the pH range of a typical feed solution. In order to enhance the removal of cations (such as Mg or Ca ), we utilized polyethyleneimine (PEI) and trimesoyl chloride (TMC) to perform interfacial polymerization reaction on a polydopamine coated hydrolyzed polyacrylonitrile substrate to obtain a positively charged nanofiltration membrane. Effects of polydopamine coating time, PEI concentration, TMC reaction time and concentration on the membrane physicochemical properties and separation performance were systematically investigated using scanning electron microscopy, streaming potential and water contact angle measurements. The optimal NF membrane showed high rejection for divalent ions (93.6±2.6% for MgSO , 92.4±1.3% for MgCl , and 90.4±2.1% for Na SO ), accompanied with NaCl rejection of 27.8±2.5% with a permeation flux of 17.2±2.8 L·m ·h at an applied pressure of 8 bar (salt concentrations were all 1000 mg·L ). The synthesized membranes showed promising potentials for the applications of water softening.

关键词： nanofiltration polyethyleneimine trimesoyl chloride polydopamine positively charged rejection layer

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冶金行业呼吸性粉尘的喷雾净化技术研究

邹声华,李刚,李孔清

《中国工程科学》 2007年第9卷第11期页码 196-199

摘要：

阐述了呼吸性粉尘的特点和危害，介绍了近年来国内外在呼吸性粉尘防治和控制方面的新技术，分析了各种降尘技术的机理并进行了比较。结果表明：在钢铁企业呼吸性粉尘的净化研究中，采用添加湿润剂的荷电水雾降尘技术是一种较好的治理方案。通过理论分析和试验研究，将该项技术应用于某钢铁企业的呼吸性粉尘的净化中，取得了良好的降尘效果。

关键词：呼吸性粉尘湿润剂超声雾化磁化水荷电水雾降尘效果

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Metal cation removal by P(VC-r-AA) copolymer ultrafiltration membranes

Nachuan Wang, Jun Wang, Peng Zhang, Wenbin Wang, Chuangchao Sun, Ling Xiao, Chen Chen, Bin Zhao, Qingran Kong, Baoku Zhu

《化学科学与工程前沿（英文）》 2018年第12卷第2期页码 262-272 doi: 10.1007/s11705-017-1682-7

摘要： A series of amphiphilic copolymers containing poly(vinyl chloride-r-acrylic acid) (P(VC-r-AA) ) was synthesized and used to prepare membranes via a non-solvent induced phase separation method. The prepared membranes were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and water contact angle and zeta potential measurements. The copolymer P(VC-r-AA) chains did not dissolved in a coagulation bath, indicating that the AA segments were completely retained within the membrane. Enriching degree of AA segments in surface layer was 2 for copolymer membrane. In addition, the introduction of AA segments made the membrane electronegative and hydrophilic so that the membrane was sensitive to the solution pH. The fouling resistance, adsorption of Cu(II), Cr(III) and Ce(IV) ions and the desorption properties of the membranes were also determined. The copolymer membranes exhibited good antifouling performance with a fouling reversibility of 92%. The membranes also had good adsorption capacities for Cu(II), Cr(III) and Ce(IV) ions. The optimal pH for Cu(II) adsorption was 6 and the copolymer membrane has potential applications for low concentration Cu(II) removal.

关键词： poly(vinyl chloride-r-acrylic acid) negatively charged PVC membrane anti-fouling heavy metal adsorption Cu(II) removal

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微波无线能量收集技术——统一模型、自动化整流天线设计及前沿技术 Review

Si-Ping Gao, Jun-Hui Ou, Xiuyin Zhang, Yongxin Guo

《工程（英文）》 2023年第30卷第11期页码 32-48 doi: 10.1016/j.eng.2023.05.019

摘要：

While sufficient review articles exist on inductive short-range wireless power transfer (WPT), long-haul microwave WPT (MWPT) for solar power satellites, and ambient microwave wireless energy harvesting (MWEH) in urban areas, few studies focus on the fundamental modeling and related design automation of receiver systems. This article reviews the development of MWPT and MWEH receivers, with a focus on rectenna design automation. A novel rectifier model capable of accurately modeling the rectification process under both high and low input power is presented. The model reveals the theoretical boundary of radio frequency-to-direct current (dc) power conversion efficiency and, most importantly, enables an automated system design. The automated rectenna design flow is sequential, with the minimal engagement of iterative optimization. It covers the design automation of every module (i.e., rectifiers, matching circuits, antennae, and dc–dc converters). Scaling-up of the technique to large rectenna arrays is also possible, where the challenges in array partitioning and power combining are briefly discussed. In addition, several cutting-edge rectenna techniques for MWPT and MWEH are reviewed, including the dynamic range extension technique, the harmonics-based retro-directive technique, and the simultaneous wireless information and power transfer technique, which can be good complements to the presented automated design methodology.

关键词：微波无线能量传输微波无线能量收集统一整流器模型自动化整流天线设计新兴整流天线技术