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Long-term observation of air pollution-weather/climate interactions at the SORPES station: a review and outlook

Aijun Ding,Wei Nie,Xin Huang,Xuguang Chi,Jianning Sun,Veli-Matti Kerminen,Zheng Xu,Weidong Guo,Tuukka Petäjä,Xiuqun Yang,Markku Kulmala,Congbin Fu

《环境科学与工程前沿(英文)》 2016年 第10卷 第5期 doi: 10.1007/s11783-016-0877-3

摘要: The concept design and detailed information of the SORPES station are introduced. Main scientific findings based 5-year measurements at the station are summarized. The future outlook of the development plan and its implications are discussed. The results improved understanding of interaction of physical and chemical processes. More SORPES-type stations are need to in different regions in China and the world. This work presents an overall introduction to the Station for Observing Regional Processes of the Earth System – SORPES in Nanjing, East China, and gives an overview about main scientific findings in studies of air pollution-weather/climate interactions obtained since 2011. The main results summarized in this paper include overall characteristics of trace gases and aerosols, chemical transformation mechanisms for secondary pollutants like O , HONO and secondary inorganic aerosols, and the air pollution – weather/climate interactions and feedbacks in mixed air pollution plumes from sources like fossil fuel combustion, biomass burning and dust storms. The future outlook of the development plan on instrumentation, networking and data-sharing for the SORPES station is also discussed.

关键词: Secondary pollution     Ground-based measurement     Planetary boundary layer meteorology     Earth system processes    

城市立交桥爆破拆除塌落振动的测量与分析

胡进军,杨永强,管英珺

《中国工程科学》 2014年 第16卷 第11期   页码 90-95

摘要:

为分析城市立交桥爆破拆除时结构构件塌落造成的地面振动的特征,介绍了某城市典型立交桥的爆破拆除中地面振动的测量方法,并基于观测点实测数据对地面振动的加速度峰值、频率和持时进行了分析。分析结果表明:塌落造成的竖向地振动幅值比水平分量大,但是其随着距离增大迅速衰减,因此在距离塌落处较近的区域应该考虑竖向地振动的影响;桥梁结构多次连续塌落会导致出现地面振动的叠加,采取减隔振措施可以降低加速度峰值,同时也会使得加速度的峰值频率降低、持时增加;爆破和塌落振动并未对保留桥梁结构造成损伤,说明爆破拆除是一种安全、高效的拆除方法。

关键词: 爆破拆除     城市立交桥     塌落     地面振动     加速度    

中国首个地基高分辨率傅里叶变换光谱观测站的大气成分长期观测研究 Article

刘诚, 孙友文, 单唱功, 王薇, Justus Notholt, Mathias Palm, 殷昊, 田园, 高吉熹, 毛慧琴

《工程(英文)》 2023年 第22卷 第3期   页码 201-214 doi: 10.1016/j.eng.2021.11.022

摘要:

长期观测主要大气成分的体积混合比(VMR)廓线和柱总量对掌握中国气候变化和碳收支具有重要意义。本文对我国首个全球碳总柱观测网(TCCON)高分辨率傅里叶变换光谱仪(FTS)地基观测站,即合肥观测站开展了系统性研究。该观测站可观测30多种大气成分的柱总量和VMR廓线。本文公布了2014年以来合肥观测站观测到的部分关键大气成分的时间序列,总结了迄今为止该站点取得的主要研究成果,包括光谱反演表征和归一化、关键大气成分的总体演变特征、排放估计、卫星和化学传输模式(CTM)校验以及对大气污染来源和传输的相关研究。同时,本文还对合肥观测站的观测、科学研究和未来研究计划进行了展望。中国明确提出2030年二氧化碳排放达到峰值,2060年实现碳中和。合肥观测站将为中国政府制定绿色经济政策、实现碳中和及《巴黎协定》目标提供科学支撑。

关键词: 遥感     傅里叶变换     大气污染     温室气体     气候变化    

Real-time tool condition monitoring method based on temperature measurement and artificial neural network

《机械工程前沿(英文)》 doi: 10.1007/s11465-021-0661-3

摘要: Tool failures in machining processes often cause severe damages of workpieces and lead to large quantities of loss, making tool condition monitoring an important, urgent issue. However, problems such as practicability still remain in actual machining. Here, a real-time tool condition monitoring method integrated in an in situ fiber optic temperature measuring apparatus is proposed. A thermal simulation is conducted to investigate how the fluctuating cutting heats affect the measuring temperatures, and an intermittent cutting experiment is carried out, verifying that the apparatus can capture the rapid but slight temperature undulations. Fourier transform is carried out. The spectrum features are then selected and input into the artificial neural network for classification, and a caution is given if the tool is worn. A learning rate adaption algorithm is introduced, greatly reducing the dependence on initial parameters, making training convenient and flexible. The accuracy stays 90% and higher in variable argument processes. Furthermore, an application program with a graphical user interface is constructed to present real-time results, confirming the practicality.

关键词: tool condition monitoring     cutting temperature     neural network     learning rate adaption    

Seismic responses and resilience of novel SMA-based self-centring eccentrically braced frames under near-faultground motions

Zhi-Peng CHEN; Songye ZHU

《结构与土木工程前沿(英文)》 2022年 第16卷 第8期   页码 962-975 doi: 10.1007/s11709-022-0873-6

摘要: In this paper, the seismic responses and resilience of a novel K-type superelastic shape memory alloy (SMA) self-centring (SC) eccentrically braced frame (EBF) are investigated. The simulation models of the SMA-based SC-EBF and a corresponding equal-stiffness traditional EBF counterpart are first established based on some existing tests. Then twenty-four near-fault ground motions are used to examine the seismic responses of both EBFs under design basis earthquake (DBE) and maximum considered earthquake (MCE) levels. Structural fragility and loss analyses are subsequently conducted through incremental dynamic analyses (IDA), and the resilience of the two EBFs are eventually estimated. The resilience assessment basically follows the framework proposed by Federal Emergency and Management Agency (FEMA) with the additional consideration of the maximum residual inter-storey drift ratio (MRIDR). The novel SMA-based SC-EBF shows a much better resilience in the study and represents a promising attractive alternative for future applications.

关键词: shape memory alloy     eccentrically braced frame     self-centring     fragility     loss function     resilience    

Measurement of activity coefficients at infinite dilution for hydrocarbons in imidazolium-based ionic

ZHU Jiqin, YU Yanmei, CHEN Jian, FEI Weiyang

《化学科学与工程前沿(英文)》 2007年 第1卷 第2期   页码 190-194 doi: 10.1007/s11705-007-0035-3

摘要: The separations of olefin/paraffin, aromatic/aliphatic hydrocarbons or olefin isomers using ionic liquids instead of volatile solvents have interested many researchers. Activity coefficients γ at infinite dilution of a solute in ionic liquid are generally used in the selection of solvents for extraction or extractive distillation. In fact, the measurement of γ by gas-liquid chromatography is a speedy and cost-saving method. Activity coefficients at infinite dilution of hydrocarbon solutes, such as alkanes, hexenes, alkylbenzenes, styrene, in 1-allyl-3-methylimidazolium tetrafluoroborate ([AMIM][BF]) and 1-butyl-3-methyl imidazolium hexafluorophosphate ([BMIM][PF6]), 1-isobutenyl-3-methylimidazolium tetrafluoroborate ([MPMIM][BF]) and [MPMIM][BF]-AgBF have been determined by gas-liquid chromatography using ionic liquids as stationary phase. The measurements were carried out at different temperatures from 298 to 318 K. The separating effects of these ionic liquids for alkanes/hexane, aliphatic hydrocarbons/benzene and hexene isomers have been discussed. The hydrophobic parameter, dipole element, frontier molecular orbital energy gap and hydration energy of these hydrocarbons were calculated with the PM3 semi-empirical quantum chemistry method. The quantitative relations among the computed structure parameters and activity coefficients at infinite dilution were also developed. The experimental activity coefficient data are consistent with the correlated and predicted results using QSPR models.

关键词: cost-saving     consistent     coefficient     measurement     separating    

Mechanical responses of multi-layered ground due to shallow tunneling with arbitrary ground surface load

《结构与土木工程前沿(英文)》 2023年 第17卷 第5期   页码 745-762 doi: 10.1007/s11709-023-0935-4

摘要: An analytical model based on complex variable theory is proposed to investigate ground responses due to shallow tunneling in multi-layered ground with an arbitrary ground surface load. The ground layers are assumed to be linear-elastic with full-stick contact between them. To solve the proposed multi-boundary problem, a series of analytic functions is introduced to accurately express the stresses and displacements contributed by different boundaries. Based on the principle of linear-elastic superposition, the multi-boundary problem is converted into a superposition of multiple single-boundary problems. The conformal mappings of different boundaries are independent of each other, which allows the stress and displacement fields to be obtained by the sum of components from each boundary. The analytical results are validated based on numerical and in situ monitoring results. The present model is superior to the classical model for analyzing ground responses of shallow tunneling in multi-layered ground; thus, it can be used with assurance to estimate the ground movement and surface building safety of shallow tunnel constructions beneath surface buildings. Moreover, the solution for the ground stress distribution can be used to estimate the safety of a single-layer composite ground.

关键词: analytical model     mechanical response     multi-layered ground     shallow tunneling     ground surface load     complex variable solution    

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    

Experimental studies of ash film fractions based on measurement of cenospheres geometry in pulverized

Siqi LIU, Yanqing NIU, Liping WEN, Yang LIANG, Bokang YAN, Denghui WANG, Shi’en HUI

《能源前沿(英文)》 2021年 第15卷 第1期   页码 91-98 doi: 10.1007/s11708-020-0806-9

摘要: In pulverized coal particle combustion, part of the ash forms the ash film and exerts an inhibitory influence on combustion by impeding the diffusion of oxygen to the encapsulated char core, while part of the ash diffuses toward the char core. Despite the considerable ash effects on combustion, the fraction of ash film still remains unclear. However, the research of the properties of cenospheres can be an appropriate choice for the fraction determination, being aware that the formation of cenospheres is based on the model of coal particles with the visco-plastic ash film and a solid core. The fraction of ash film is the ratio of the measuring mass of ash film and the total ash in coal particle. In this paper, the Huangling bituminous coal with different sizes was burnt in a drop-tube furnace at 1273, 1473, and 1673 K with air as oxidizer. A scanning electron microscope (SEM) and cross-section analysis have been used to study the geometry of the collected cenospheres and the effects of combustion parameters on the fraction of ash film. The results show that the ash film fraction increases with increasing temperature and carbon conversion ratio but decreases with larger sizes of coal particles. The high fraction of ash film provides a reasonable explanation for the extinction event at the late burnout stage. The varied values of ash film fractions under different conditions during the dynamic combustion process are necessary for further development of kinetic models.

关键词: ash film fraction     cenospheres     coal combustion     fly ash    

R&D of the ground-coupled heat pump technology in China

Nairen DIAO, Ping CUI, Junhong LIU, Zhaohong FANG,

《能源前沿(英文)》 2010年 第4卷 第1期   页码 47-54 doi: 10.1007/s11708-009-0080-3

摘要: The ground-coupled heat pump (GCHP) systems have been identified as one of the best sustainable energy technologies for space heating and cooling in residential and commercial buildings. In this paper, research on and development of the GCHP technology in China are summarized. New models are presented for efficient thermal analysis of ground heat exchangers, of which one- and two-dimensional solid cylindrical source models and their analytical solutions are devised to deal with pile ground heat exchangers. Analytical solutions are also derived for vertical and inclined finite line source models as well as for a groundwater advection model. Explicit solutions of a quasi-three-dimensional model can be used to better evaluate the thermal resistance inside boreholes. Studies on hybrid GCHP systems and the thermal response test in China are also commented.

关键词: ground source heat pump     ground heat exchanger     HVAC     China    

INTERACTIONS BETWEEN ABOVE AND BELOW GROUND PLANT STRUCTURES: MECHANISMS AND ECOSYSTEM SERVICES

《农业科学与工程前沿(英文)》 2022年 第9卷 第2期   页码 197-213 doi: 10.15302/J-FASE-2021433

摘要:

Interactions between above and below ground parts of plants can be considered under the (overlapping) categories of energy, material and information. Solar energy powers photosynthesis and transpiration by above ground structures, and drives most water uptake through roots and supplies energy as organic matter to below ground parts, including diazotrophic symbionts and mycorrhizas. Material transfer occurs as water and dissolved soil-derived elements transport up the xylem, and a small fraction of water moving up the xylem with dissolved organic carbon and other solutes down the phloem. The cytosolic nature of sieve tubes accounts for at least some of the cycling of K, Mg and P down the phloem. NO3 assimilation of above ground parts requires organic N transport down phloem with, in some cases, organic anions related to shoot acid-base regulation. Long-distance information transfer is related development, biotic and abiotic damage, and above and below ground resource excess and limitation. Information transfer can involve hydraulic, electrical and chemical signaling, with their varying speeds of transmission and information content. Interaction of above and below ground plant parts is an important component of the ecosystem service of storing atmospheric CO2 as organic C in soil, a process that has decreased since the origin of agriculture.

关键词: aerenchyma / carbon accumulation / hormones / phloem / xylem    

Shanghai center project excavation induced ground surface movements and deformations

Guolin XU, Jiwen ZHANG, Huang LIU, Changqin REN

《结构与土木工程前沿(英文)》 2018年 第12卷 第1期   页码 26-43 doi: 10.1007/s11709-017-0439-1

摘要: Empirical data on deep urban excavations can provide designers a significant reference basis for assessing potential deformations of the deep excavations and their impact on adjacent structures. The construction of the Shanghai Center involved excavations in excess of 33-m-deep using the top-down method at a site underlain by thick deposits of marine soft clay. A retaining system was achieved by 50-m-deep diaphragm walls with six levels of struts. During construction, a comprehensive instrumentation program lasting 14 months was conducted to monitor the behaviors of this deep circular excavation. The following main items related to ground surface movements and deformations were collected: (1) walls and circumferential soils lateral movements; (2) peripheral soil deflection in layers and ground settlements; and (3) pit basal heave. The results from the field instrumentation showed that deflections of the site were strictly controlled and had no large movements that might lead to damage to the stability of the foundation pit. The field performance of another 21cylindrical excavations in top-down method were collected to compare with this case through statistical analysis. In addition, numerical analyses were conducted to compare with the observed data. The extensively monitored data are characterized and analyzed in this paper.

关键词: deep excavation     foundation pit     soft clay     top-down method     field observation     ground surface movements     ground deformations    

Seismic ground motion analysis of Shanghai Pudong Airport site considering the effects of spatial correlation

JIANG Tong, CHEN Laiyun, XING Hailing, L? Xilin

《结构与土木工程前沿(英文)》 2007年 第1卷 第4期   页码 430-435 doi: 10.1007/s11709-007-0058-3

摘要: The terminal No. II of Shanghai Pudong International Airport is located at Pudong District of Shanghai City near shore of East China Sea, and the area of the long-span terminal is 400 m × 200 m. The construction site of the terminal locates on the irregular topography, and its alluvium achieves about 300 m in thickness. The spatial correlation of seismic ground motion, as well as the amplification of soft alluvium and the effect of irregular topography, should be considered. This paper uses a simplified method to obtain the response spectrum of the engineering bedrock under the irregular topography. The spectrum is used to generate the sets of spatially correlative horizontal and vertical seismic motions. The surface ground motion was calculated under incidence of the spatially correlative seismic motion by 2D finite element method (FEM) model considering nonlinear properties of the soil by means of the equivalent linear method. In order to compare the effect of 2D irregular topography, the seismic response analysis of 1D model is carried out by using the equivalent linear method. For indicating the effect of the spatial correlation of input motions, the horizontal uniform inputs, as well as the horizontal and vertical uniform input are carried out for the seismic response analysis of the site. Finally, some characteristics of seismic ground motion calculated for previously mentioned cases are compared.

关键词: surface ground     horizontal uniform     Finally     seismic ground     correlative seismic    

Evaluation of measurement uncertainty of the high-speed variable-slit system based on the Monte Carlo

Yin ZHANG, Jianwei WU, Kunpeng XING, Zhongpu WEN, Jiubin TAN

《机械工程前沿(英文)》 2020年 第15卷 第4期   页码 517-537 doi: 10.1007/s11465-020-0589-z

摘要: This paper presents a dynamic and static error transfer model and uncertainty evaluation method for a high-speed variable-slit system based on a two-dimensional orthogonal double-layer air-floating guide rail structure. The motion accuracy of the scanning blade is affected by both the moving component it is attached to and the moving component of the following blade during high-speed motion. First, an error transfer model of the high-speed variable-slit system is established, and the influence coefficients are calculated for each source of error associated with the accuracy of the blade motion. Then, the maximum range of each error source is determined by simulation and experiment. Finally, the uncertainty of the blade displacement measurement is evaluated using the Monte Carlo method. The proposed model can evaluate the performance of the complex mechanical system and be used to guide the design.

关键词: air-floating guide rail     error transfer model     driving and following structure     dynamic error     uncertainty evaluation     Monte Carlo method    

地基超光谱立体遥感网络——一种探究中国PM2.5和O3协同控制的新策略 Article

刘诚, 邢成志, 胡启后, 李启华, 刘浩然, 洪茜茜, 谈伟, 季祥光, 林华, 陆川, 林继楠, 刘瀚洋, 魏少聪, 陈健, 杨昆鹏, 王顺天, 柳婷, 陈羽佳

《工程(英文)》 2022年 第19卷 第12期   页码 71-83 doi: 10.1016/j.eng.2021.02.019

摘要:

进入“十四五”时期,PM2.5(空气动力学当量直径小于等于2.5 μm的颗粒物)和O3的协同控制成为我国大气污染防治的重大课题。PM2.5、O3及其前体物的立体监测对于实现协同控制至关重要。然而,目前的监测网络不足以同时监测PM2.5和O3的垂直分布以及支持空气质量控制。2015 年以来,中国科学技术大学(USTC)基于多轴差分吸收光谱仪(MAX-DOAS)在全国范围内主导建立了地基超光谱遥感网络。该立体监测网络为我国PM2.5和O3的区域协同控制提供了重要机遇。基于搭设于四个特大城市(北京、上海、深圳和重庆)的四个MAX-DOAS 监测站获取的一年时间的气溶胶、NO2和HCHO的垂直廓线,探究京津冀(JJJ)、长三角(YRD)、珠三角(PRD)和四川盆地(SB)四大典型污染区域的大气污染物垂直分布差异。400 m以下归一化和年平均的气溶胶垂直廓线在JJJ 和PRD地区分别呈箱型和高斯型分布,在YRD和SB地区都呈E指数型分布。由于四个区域的NO2都主要来自交通车辆排放,因此NO2在四个区域都呈E指数型分布。HCHO垂直廓线在JJJ 和PRD地区呈高斯型分布,在YRD和SB地区呈E指数型分布。此外,立体监测网络中的五个MAX-DOAS 站点[石家庄(SJZ)、望都(WD)、南城(NC)、中国气象科学研究院(CAMS)和中国科学院大学(UCAS)]同时监测到一次发生在华北平原(NCP)西南—东北通道海拔600~1000 m 的典型区域传输事件。气溶胶光学厚度(AOD)在上述五个站点表现为SJZ > WD > NC > CAMS > UCAS。在WD和NC之间监测到了发生在700~900 m高空的NO2短距离区域传输。作为二次气溶胶的重要前体物,研究发现WD和NC的NO2气团峰值均比其气溶胶消光气团峰值早出现约1 h。同时监测到了NC和CAMS之间发生在700~900 m高空的HCHO短距离区域传输,这可能会对北京的O3浓度造成潜在影响。最后,选择CAMS作为典型站点探究垂直方向O3-NOx-挥发性有机化合物(VOC)的敏感性。研究发现O3在0~100 m和100~200 m高度层分别受VOC控制和VOC-NOx混合控制。此外,O3的向下输送也可能会增加近地面O3的浓度。该地基超光谱立体遥感网络为支持PM2.5、O3及其前体物的管控和溯源提供了一种非常具有前景的策略。

关键词: 多轴差分吸收光谱仪     立体监测     区域传输     臭氧生成     控制策略    

标题 作者 时间 类型 操作

Long-term observation of air pollution-weather/climate interactions at the SORPES station: a review and outlook

Aijun Ding,Wei Nie,Xin Huang,Xuguang Chi,Jianning Sun,Veli-Matti Kerminen,Zheng Xu,Weidong Guo,Tuukka Petäjä,Xiuqun Yang,Markku Kulmala,Congbin Fu

期刊论文

城市立交桥爆破拆除塌落振动的测量与分析

胡进军,杨永强,管英珺

期刊论文

中国首个地基高分辨率傅里叶变换光谱观测站的大气成分长期观测研究

刘诚, 孙友文, 单唱功, 王薇, Justus Notholt, Mathias Palm, 殷昊, 田园, 高吉熹, 毛慧琴

期刊论文

Real-time tool condition monitoring method based on temperature measurement and artificial neural network

期刊论文

Seismic responses and resilience of novel SMA-based self-centring eccentrically braced frames under near-faultground motions

Zhi-Peng CHEN; Songye ZHU

期刊论文

Measurement of activity coefficients at infinite dilution for hydrocarbons in imidazolium-based ionic

ZHU Jiqin, YU Yanmei, CHEN Jian, FEI Weiyang

期刊论文

Mechanical responses of multi-layered ground due to shallow tunneling with arbitrary ground surface load

期刊论文

density measurement for plastic injection molding via ultrasonic technology

期刊论文

Experimental studies of ash film fractions based on measurement of cenospheres geometry in pulverized

Siqi LIU, Yanqing NIU, Liping WEN, Yang LIANG, Bokang YAN, Denghui WANG, Shi’en HUI

期刊论文

R&D of the ground-coupled heat pump technology in China

Nairen DIAO, Ping CUI, Junhong LIU, Zhaohong FANG,

期刊论文

INTERACTIONS BETWEEN ABOVE AND BELOW GROUND PLANT STRUCTURES: MECHANISMS AND ECOSYSTEM SERVICES

期刊论文

Shanghai center project excavation induced ground surface movements and deformations

Guolin XU, Jiwen ZHANG, Huang LIU, Changqin REN

期刊论文

Seismic ground motion analysis of Shanghai Pudong Airport site considering the effects of spatial correlation

JIANG Tong, CHEN Laiyun, XING Hailing, L? Xilin

期刊论文

Evaluation of measurement uncertainty of the high-speed variable-slit system based on the Monte Carlo

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