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Erratum to: Determination of cut-off time of accelerated aging test under temperature stress for LED

Jian Hao, Lei Jing, Hong-liang Ke, Yao Wang, Qun Gao, Xiao-xun Wang, Qiang Sun, Zhi-jun Xu,sunq@ciomp.ac.cn

《信息与电子工程前沿(英文)》 2017年 第18卷 第10期   页码 1678-1678 doi: 10.1631/FITEE.15e0483

摘要: Erratum to: , 2017 18(8):1197-1204. doi:

关键词: LED lamp     Accelerated aging test     Medium lifetime     Moving average error    

LED灯具温度应力加速老化截止时间的确定 Article

Jian HAO, Lei JING, Hong-liang KE, Yao WANG, Qun GAO, Xiao-xun WANG, Qiang SUN, Zhi-jun XU

《信息与电子工程前沿(英文)》 2017年 第18卷 第10期   页码 1678-1678 doi: 10.1631/FITEE.1500483

摘要: 在LED灯具加速老化过程中,为获得最小截止时间,对其寿命进行快速预估,本文采用5阶滑动平均误差方法分析数据。选用同批次的16个样本,分别进行80℃和85℃应力条件下的加速老化。首先,采用e指数对光通维持率进行拟合,获得每个灯具的加速寿命,进而采用威布尔分布对加速寿命进行拟合,获得中位寿命。其次,采用平均滑动误差方法,可获取不同截止时间下中位寿命预估误差。结果表明:加速老化过程中,存在最小截止时间,该时间可通过滑动平均误差和截止时间的关系确定;当截止时间小于该值时,寿命预估不合理;寿命预估误差随截止时间增加而逐渐减小。对于该类LED灯具,80℃时最小截止时间为1104小时,寿命预估误差为1.15%;85℃时最小截止时间为936小时,寿命预估误差为1.24%。当寿命估计误差约为0.46%时,80 ℃和85 ℃对应的中位寿命分别为7310小时和4598小时。

关键词: LED灯具;加速老化测试;中位寿命;滑动平均误差    

Accelerated life-time test of MEA durability under vehicle operating conditions in PEM fuel cell

Tian TIAN, Jianjun TANG, Wei GUO, Mu PAN

《能源前沿(英文)》 2017年 第11卷 第3期   页码 326-333 doi: 10.1007/s11708-017-0489-z

摘要: In this paper, a novel accelerated test method was proposed to analyze the durability of MEA, considering the actual operation of the fuel cell vehicle. The proposed method includes 7 working conditions: open circuit voltage (OCV), idling, rated output, overload, idling-rated cycle, idling-overload cycle, and OCV-idling cycle. The experimental results indicate that the proposed method can effectively destroy the MEA in a short time (165 h). Moreover, the degradation mechanism of MEA was analyzed by measuring the polarization curve, CV, SEM and TEM. This paper may provide a new research direction for improving the durability of fuel cell.

关键词: polymer electrolyte membrane fuel cell     accelerated life-time test     load cycling test     durability    

Pretest analysis of shake table response of a two-span steel girder bridge incorporating accelerated

Elmira SHOUSHTARI, M. Saiid SAIIDI, Ahmad ITANI, Mohamed A. MOUSTAFA

《结构与土木工程前沿(英文)》 2020年 第14卷 第1期   页码 169-184 doi: 10.1007/s11709-019-0590-y

摘要: This paper presents pretest analysis of a shake table test model of a 0.35-scale, two-span, steel plate girder bridge. The objective of pretest analysis was to obtain an insight on the seismic response of the bridge model during the shake table tests. The bridge included seat type abutments, full-depth precast deck panels, and a two-column bent in which columns were pinned to the footing and integral with superstructure. Six accelerated bridge construction connections were incorporated in the bridge model. An analytical model was developed in OpenSees and was subjected to ten input bi-directional earthquake motions including near-fault and far-field records. The overall seismic response of the bridge was satisfactory for all the earthquake records at 100%, 150%, and 200% design level. All connections and capacity-protected components remained elastic, and the average ductility capacity surpassed the ductility demand even at 200% design level. Using experimental fragility curves developed for RC bridge columns, it was predicted that there was a probability of 45% that columns would undergo the imminent failure in the last run and a probability of 30% for their failure.

关键词: shake table test     accelerated bridge construction     steel girder bridge     OpenSEES     UHPC     simple for dead continuous for live    

基于风险分析的可靠性指标加速验证方法研究

张辉睿

《中国工程科学》 2015年 第17卷 第5期   页码 31-37

摘要:

传统的可靠性验证试验由于一般在使用条件下进行,且只利用失效数据进行判定,往往需要大量的时间和费用。这对于高可靠长寿命船舶设备可靠性指标的验证是不可接受的。本文提出一种基于风险分析的可靠性指标加速验证方法,该方法利用退化数据进行分析,在试验风险可接受的条件下提前截止试验,得出验证结果。同时,利用高环境应力可以加速退化过程,进一步减少试验时间。本文具体给出了分析和计算提前截止试验和利用高应力进行试验产生的额外风险的方法,保证了验证结果的真实可靠。最后利用案例证实了该方法在减少验证试验时间上的有效性。

关键词: 退化数据;加速验证试验;可靠性验证;风险分析;优化设计    

淀粉基API胶合木胶接结构破坏模式及失效机理

时君友,徐文彪,王淑敏

《中国工程科学》 2014年 第16卷 第4期   页码 40-44

摘要:

以淀粉基水性高分子异氰酸酯(API)胶合木胶接结构为研究对象,以胶接的压缩剪切强度为评估指标,通过加速湿热老化试验对胶接结构的破坏模式和失效机理进行了研究。结果表明:胶接结构的断裂性质为韧性断裂,且随着老化时间的增加,其破坏模式为由内聚破坏向内聚破坏+界面破坏转变。在湿热老化试验前期温度对压缩剪切试样性能起主要作用,在老化后期湿度起主要作用。

关键词: 胶接结构     加速湿热老化     断裂性质     破坏模式    

the characterization of pore structures and permeability of diesel contaminated clays under different aging

《结构与土木工程前沿(英文)》   页码 1264-1280 doi: 10.1007/s11709-023-0921-x

摘要: In this study, mercury intrusion porosimetry (MIP) and X-ray micro-computed tomography (XRμCT) were used to characterize the pore structures and investigate the permeability characteristics of clay after aging and contamination with diesel. The results of the MIP tests showed that aging leads to reductions in porosity and average diameter, as well as an increase in tortuosity. The XRμCT analysis yielded consistent results; it showed that aging renders pores more spherical and isotropic and pore surfaces smoother. This weakens the pore connectivity. Micromorphological analysis revealed that aging led to the rearrangement of soil particles, tighter interparticle overlapping, and a reduction in pore space. The combination of MIP and XRμCT provided a comprehensive and reliable characterization of the soil pore structure. An increased diesel content increased the porosity and average diameter and reduced the tortuosity of the pores. Mechanistic analysis showed that aging weakens interparticle cohesion; this causes large agglomerates to break down into smaller agglomerates, resulting in a tighter arrangement and a subsequent reduction in porosity. An increase in diesel content increases the number of large agglomerates and pore spaces between agglomerates, resulting in increased porosity. Both aging and diesel content can weaken the permeation characteristics of soil.

关键词: MIP     XRμCT     aging     diesel content     pore structure     permeability characteristics    

Mechanism and characterization of microplastic aging process: A review

《环境科学与工程前沿(英文)》 2023年 第17卷 第8期 doi: 10.1007/s11783-023-1700-6

摘要:

● Methods for estimating the aging of environmental micro-plastics were highlighted.

关键词: Microplastics     Aging     Degradation     Characterization     Mechanism    

Monitoring corrosion of reinforcement in concrete structures via fiber Bragg grating sensors

Zhupeng ZHENG, Xiaoning SUN, Ying LEI

《机械工程前沿(英文)》 2009年 第4卷 第3期   页码 316-319 doi: 10.1007/s11465-009-0040-y

摘要: Corrosion of steel and rebar in concrete structures is one of the most frequent reasons for civil infrastructure failures. Thus, improving the effective corrosion sensor technology can greatly reduce cost and provide safe structures with long service lives. However, assessing the corrosion condition of rebars is not simple because they are buried in concrete. In this paper, using fiber Bragg grating (FBG), a corrosion sensor for monitoring steel rebars embedded in a concrete structure is developed and validated by experiments. Based on the fact that the volume and diameter of a rebar embedded in concrete will enlarge due to corrosion, an FBG packaged with fiber-reinforced plastics (FRP) is wrapped on the steel bar. During corrosion, the increase in the bar diameter leads to the increase in fiber strain, which can be measured by the shift of the wavelength of FBG. Performances of the corrosion sensor are validated by accelerating corrosion in lab experiments. The corrosion sensor is embedded in a concrete specimen put in a 5% sodium chloride solution with a constant current. Experimental results show that the corrosion sensor can monitor the concurrence of corrosion of rebars in concrete. The corrosion extent can be quantitatively evaluated through the change in the wavelength of FBG. Therefore, the corrosion sensor developed in this paper is feasible for monitoring the early corrosion of rebars in concrete.

关键词: fiber Bragg grating (FBG)     corrosion     concrete structures     accelerated corrosion test    

Aging properties and aging mechanism of activated waste rubber powder modified asphalt binder based on

《结构与土木工程前沿(英文)》 2023年 第17卷 第4期   页码 625-636 doi: 10.1007/s11709-023-0938-1

摘要: The research and development of high-performance pavement materials has been intensified owing to the demand for long-life pavements. This study is performed to develop a novel pavement material using waste rubber powder, waste lubricating by-product (LBP), and asphalt. Subsequently, the aging properties and aging mechanism of activated waste rubber powder modified asphalt (ARMA) are investigated based on its rheological properties and micro-characterization. The rheological results show that, compared with waste rubber powder modified asphalt (RMA), ARMA offers a higher aging resistance and a longer fatigue life. A comparison and analysis of the rheological aging parameters of ARMA and RMA show that LBP activation diminishes the aging sensitivity of ARMA. The micro-characterization result shows that the aging of ARMA may be caused by the fact that LBP-activated waste rubber powder is more reactive and can form a dense colloidal structure with asphalt. Therefore, the evaporation loss of asphalt light components by heat and the damage to the colloidal structure by oxygen during the aging process are impeded, and the thermal-oxidative aging resistance of ARMA is improved.

关键词: rubber powder modified asphalt     aging     mechanism     rheological     characterization    

Insights into influence of aging processes on zero-valent iron modified biochar in copper(II) immobilization

《化学科学与工程前沿(英文)》 2023年 第17卷 第7期   页码 880-892 doi: 10.1007/s11705-022-2282-8

摘要: The zero-valent iron modified biochar materials are widely employed for heavy metals immobilization. However, these materials would be inevitably aged by natural forces after entering into the environment, while there are seldom studies reported the aging effects of zero-valent iron modified biochar. In this work, the hydrogen peroxide and hydrochloric acid solution were applied to simulate aging conditions of zero-valent iron modified biochar. According to the results, the adsorption capacity of copper(II) contaminants on biochar, zero-valent iron modified biochar-1, and zero-valent iron modified biochar-2 after aging was decreased by 15.36%, 22.65% and 23.26%, respectively. The surface interactions were assigned with chemisorption occurred on multi-molecular layers, which were proved by the pseudo-second-order and Langmuir models. After aging, the decreasing of capacity could be mainly attributed to the inhibition of ion-exchange and zero-valent iron oxidation. Moreover, the plant growth and soil leaching experiments also proved the effects of aging treatment, the zero-valent iron modified biochar reduced the inhibition of copper(II) bioavailability and increased the mobility of copper(II) after aging. All these results bridged the gaps between bio-adsorbents customization and their environmental behaviors during practical agro-industrial application.

关键词: zero-valent iron modified biochar     aging processes     copper removal     adsorption     pilot-scale experiments    

Projections of heat-related excess mortality in China due to climate change, population and aging

《环境科学与工程前沿(英文)》 2023年 第17卷 第11期 doi: 10.1007/s11783-023-1732-y

摘要:

● Four scenarios were used to project heat-related excess mortality in China.

关键词: Heat-related excess mortality     LMDI     Aging     YLL     VSLY    

Outdoor aging of road asphalt and SBS modified asphalt

Li XIANG, Juan TU, Jian CHENG, Guohe QUE

《化学科学与工程前沿(英文)》 2011年 第5卷 第1期   页码 35-42 doi: 10.1007/s11705-010-0551-4

摘要: The process of performance degradation of road asphalt (RA) is regarded as aging. At present, better understanding of the thermal-oxidative aging of asphalt is achieved and the corresponding method to evaluate this process is developed; meanwhile, photo-oxidative aging (aging in an atmospheric environment, which is referred to as “outdoor aging” in this paper) of asphalt remains at the initial stages of scientific exploration. The outdoor natural ultraviolet (UV) aging of RA and SBS modified asphalt (SBSMA) are investigated in this study. The experimental results show that the basic performances of RA and SBSMA present similar change tendencies. The softening point increased, while the penetration and ductility decreased as the outdoor aging time passed by, and the 5°C ductility (ductility measured at 5°C) of SBSMA decreased very quickly. The group components of RA and SBSMA also change during UV aging. The content of asphaltene rose and that of aromatics and saturates decreased, while the content of resins changed insignificantly. Moreover, the Fourier transform infrared (FTIR) graphs show that the content of sulfoxide and carbonyl groups in RA and SBSMA increased significantly during the outdoor aging process.

关键词: asphalt     SBS     modified road asphalt     outdoor aging     ultraviolet    

Role of brown adipose tissue in metabolic syndrome, aging, and cancer cachexia

null

《医学前沿(英文)》 2018年 第12卷 第2期   页码 130-138 doi: 10.1007/s11684-017-0555-2

摘要:

Brown adipose tissue (BAT) plays a fundamental role in maintaining body temperature by producing heat. BAT that had been know to exist only in mammals and the human neonate has received great attention for the treatment of obesity and diabetes due to its important function in energy metabolism, ever since it is recently reported that human adults have functional BAT. In addition, beige adipocytes, brown adipocytes in white adipose tissue (WAT), have also been shown to take part in whole body metabolism. Multiple lines of evidence demonstrated that transplantation or activation of BAT or/and beige adipocytes reversed obesity and improved insulin sensitivity. Furthermore, many genes involved in BAT activation and/or the recruitment of beige cells have been found, thereby providing new promising strategies for future clinical application of BAT activation to treat obesity and metabolic diseases. This review focuses on recent advances of BAT function in the metabolic aspect and the relationship between BAT and cancer cachexia, a pathological process accompanied with decreased body weight and increased energy expenditure in cancer patients. The underlying possible mechanisms to reduce BAT mass and its activity in the elderly are also discussed.

关键词: brown adipose tissue     beige adipocyte     anti-obesity     anti-diabetes     cancer cachexia     aging    

Effect of styrene-butadiene-styrene copolymer on the aging resistance of asphalt: An atomistic understanding

《结构与土木工程前沿(英文)》 2021年 第15卷 第5期   页码 1261-1276 doi: 10.1007/s11709-021-0761-5

摘要: To reveal the potential influence of styrene-butadiene-styrene (SBS) polymer modification on the anti-aging performance of asphalt, and its mechanism, we explored the aging characteristics of base asphalt and SBS-modified asphalt by reaction force field (ReaxFF) and classical molecular dynamics simulations. The results illustrate that the SBS asphalt is more susceptible to oxidative aging than the base asphalt under oxygen-deficient conditions due to the presence of unsaturated C=C bonds in the SBS polymer. In the case of sufficient oxygen, the SBS polymer inhibits the oxidation of asphalt by restraining the diffusion of asphalt molecules. Compared with the base asphalt, the SBS asphalt exhibits a higher degree of oxidation at the early stage of pavement service and a lower degree of oxidation in the long run. In addition, SBS polymer degrades into small blocks during aging, thus counteracting the hardening of aged asphalt and partially restoring its low-temperature cracking resistance.

关键词: SBS asphalt     oxidative aging     asphalt hardening     ReaxFF     molecular dynamics    

标题 作者 时间 类型 操作

Erratum to: Determination of cut-off time of accelerated aging test under temperature stress for LED

Jian Hao, Lei Jing, Hong-liang Ke, Yao Wang, Qun Gao, Xiao-xun Wang, Qiang Sun, Zhi-jun Xu,sunq@ciomp.ac.cn

期刊论文

LED灯具温度应力加速老化截止时间的确定

Jian HAO, Lei JING, Hong-liang KE, Yao WANG, Qun GAO, Xiao-xun WANG, Qiang SUN, Zhi-jun XU

期刊论文

Accelerated life-time test of MEA durability under vehicle operating conditions in PEM fuel cell

Tian TIAN, Jianjun TANG, Wei GUO, Mu PAN

期刊论文

Pretest analysis of shake table response of a two-span steel girder bridge incorporating accelerated

Elmira SHOUSHTARI, M. Saiid SAIIDI, Ahmad ITANI, Mohamed A. MOUSTAFA

期刊论文

基于风险分析的可靠性指标加速验证方法研究

张辉睿

期刊论文

淀粉基API胶合木胶接结构破坏模式及失效机理

时君友,徐文彪,王淑敏

期刊论文

the characterization of pore structures and permeability of diesel contaminated clays under different aging

期刊论文

Mechanism and characterization of microplastic aging process: A review

期刊论文

Monitoring corrosion of reinforcement in concrete structures via fiber Bragg grating sensors

Zhupeng ZHENG, Xiaoning SUN, Ying LEI

期刊论文

Aging properties and aging mechanism of activated waste rubber powder modified asphalt binder based on

期刊论文

Insights into influence of aging processes on zero-valent iron modified biochar in copper(II) immobilization

期刊论文

Projections of heat-related excess mortality in China due to climate change, population and aging

期刊论文

Outdoor aging of road asphalt and SBS modified asphalt

Li XIANG, Juan TU, Jian CHENG, Guohe QUE

期刊论文

Role of brown adipose tissue in metabolic syndrome, aging, and cancer cachexia

null

期刊论文

Effect of styrene-butadiene-styrene copolymer on the aging resistance of asphalt: An atomistic understanding

期刊论文