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Finite element simulation for elastic dislocation of the North-Tehran fault: The effects of geologic

Pooya ZAKIAN; Hossein ASADI HAYEH

《结构与土木工程前沿（英文）》 2022年 第16卷 第4期   页码 533-549 doi: 10.1007/s11709-022-0802-8

摘要： The present study uses the finite element method for simulating the crustal deformation due to the dislocation of a segment of the North-Tehran fault located in the Karaj metropolis region. In this regard, a geological map of Karaj that includes the fault segment is utilized in order to create the geometry of finite element model. First, finite element analysis of homogeneous counterpart of the fault’s domain with two different sections was performed, and the results were compared to those of Okada’s analytical solutions. The fault was modeled with the existing heterogeneity of the domain having been considered. The influences of both uniform and non-uniform slip distributions were investigated. Furthermore, three levels of simplification for geometric creation of geological layers’ boundaries were defined in order to evaluate the effects of the geometric complexity of the geological layering on the displacement responses obtained with the finite element simulations. In addition to the assessment of slip distribution, layering complexity and heterogeneity, the results demonstrate both the capability and usefulness of the proposed models in the dislocation analysis for the Karaj segment of North-Tehran fault.

关键词： finite element method     fault dislocation     slip distribution     the North-Tehran fault     heterogeneity     geological layering    

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Application of random set method in a deep excavation: based on a case study in Tehran cemented alluvium

Arash SEKHAVATIAN, Asskar Janalizadeh CHOOBBASTI

《结构与土木工程前沿（英文）》 2019年 第13卷 第1期   页码 66-80 doi: 10.1007/s11709-018-0461-y

摘要： The design of high-rise buildings often necessitates ground excavation, where buildings are in close proximity to the construction, thus there is a potential for damage to these structures. This paper studies an efficient user-friendly framework for dealing with uncertainties in a deep excavation in layers of cemented coarse grained soil located in Tehran, Iran by non-deterministic Random Set (RS) method. In order to enhance the acceptability of the method among engineers, a pertinent code was written in FISH language of FLAC2D software which enables the designers to run all simulations simultaneously, without cumbersome procedure of changing input variables in every individual analysis. This could drastically decrease the computational effort and cost imposed to the project, which is of great importance especially to the owners. The results are presented in terms of probability of occurrence and most likely values of the horizontal displacement at top of the wall at every stage of construction. Moreover, a methodology for assessing the credibility of the uncertainty model is presented using a quality indicator. It was concluded that performing RS analysis before the beginning of every stage could cause great economical savings, while improving the safety of the project.

关键词： uncertainty     reliability analysis     deep excavations     random set method     finite difference method    

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Estimation of environmental effects of photovoltaic generation in North-west China

Mengjia REN, Anastasia SHCHERBAKOVA

《能源前沿（英文）》 2013年 第7卷 第4期   页码 535-543 doi: 10.1007/s11708-013-0280-8

摘要： In estimating emissions reductions brought about by renewables in China, much of existing research assumes that renewables displace coal power. In this paper, this assumption is challenged and the potential environmental effects of photovoltaic (PV) power in North-west China are reevaluated when the marginal generator actually being displaced is taken into account. The annual PV power generation in the North-west Grid is estimated, in this paper, to be as high as 17900 GW·h in 2015, roughly equaling to the output of 1.5 nuclear power plants in the US today. The total associated emission reduction in 2015 will at most be 0.36 percent of SO and 0.25 percent of NO emissions from their 2010 levels in China. Further, PV power may render no emissions reduction at all if it displaces hydropower, which is often used to meet peak demand in the North-west Grid in China. These results imply that a more cost-effective area of focus in the short-term may be on desulfurization and denitrification technologies for coal plants.

关键词： photovoltaic (PV)     emission reduction     North-west China     marginal generator    

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南水北调工程

Office of the South-to-North Water Diversion Project Construction Committee, State Council, PRC

《工程（英文）》 2016年 第2卷 第3期   页码 265-267 doi: 10.1016/J.ENG.2016.03.022

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Three-dimensional finite difference analysis of shallow sprayed concrete tunnels crossing a reverse faultor a normal fault: A parametric study

Masoud RANJBARNIA, Milad ZAHERI, Daniel DIAS

《结构与土木工程前沿（英文）》 2020年 第14卷 第4期   页码 998-1011 doi: 10.1007/s11709-020-0621-8

摘要： Urban tunnels crossing faults are always at the risk of severe damages. In this paper, the effects of a reverse and a normal fault movement on a transversely crossing shallow shotcreted tunnel are investigated by 3D finite difference analysis. After verifying the accuracy of the numerical simulation predictions with the centrifuge physical model results, a parametric study is then conducted. That is, the effects of various parameters such as the sprayed concrete thickness, the geo-mechanical properties of soil, the tunnel depth, and the fault plane dip angle are studied on the displacements of the ground surface and the tunnel structure, and on the plastic strains of the soil mass around tunnel. The results of each case of reverse and normal faulting are independently discussed and then compared with each other. It is obtained that deeper tunnels show greater displacements for both types of faulting.

关键词： urban tunnel     sprayed concrete     reverse fault     normal fault     finite difference analysis    

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Quantitative standard of eco-compensation for the water source area in the middle route of the South-to-North

Zhanfeng DONG, Jinnan WANG

《环境科学与工程前沿（英文）》 2011年 第5卷 第3期   页码 459-473 doi: 10.1007/s11783-010-0288-9

摘要： The Middle Route Project(MRP) of the South-to-North Water Transfer Scheme (SNWT) in China will require a very large financial expenditure to ensure the water supply and the associated water quality to northern China. An eco-compensation mechanism between the water service source areas and its beneficiaries is essential. This paper establishes an analytic framework of eco-compensation standard for the protection of the water source area, including both the calculation of eco-compensation based on opportunity cost method (OCM) and calculation of the burden sharing of eco-compensation between the water source area and the external water reception area based on the deviation square method (DSM). Taking Shiyan City, Hubei Province in China as a case study, our results show that the eco-compensation in the first-phase of MRP for the water source area in Shiyan, Hubei Province should be 1.63×10 CNY, about four times of planned eco-construction investment budget(4.33×10 CNY). In addition, the burden sharing of eco-compensation varied greatly in terms of different methods. It would be better to integrate the results of different single-factor burden sharing methods by determining the corresponding weighting coefficient with DSM and form one unanimous consent result by the interested parties.

关键词： the South-to-North Water Transfer Scheme     eco-compensation standard     opportunity costs     deviation square method    

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Perceived resource support for chronic illnesses among diabetics in north-western China

null

《医学前沿（英文）》 2016年 第10卷 第2期   页码 219-227 doi: 10.1007/s11684-016-0441-3

摘要：

A high level of social support can improve long-term diabetes self-management. Support from a single source has been evaluated. This study aims to analyze support from multiple and multilevel sources for diabetic patients by using the Chronic Illness Resources Survey (CIRS). Factors influencing the utilization of the CIRS were also evaluated. A total of 297 patients with diabetes were investigated using the CIRS and Perceived Diabetes Self-management Scale in Shihezi City, China. Descriptive statistics were used to explain demographic variables and scores of the scales. Factors affecting the utilization of chronic illness resources were determined through univariate analysis and then examined by multivariate logistic regression analysis. Of the 297 diabetic patients surveyed, 67% failed to reach the standard (more than 3 points) of utilizing chronic illness resources. Moreover, utilization of chronic illness resources was positively moderately correlated with self-management of diabetes (r = 0.75, P <0.05). According to the multivariate logistic regression analysis, age (OR, 3.42; 95%CI, 1.19–9.84) and monthly income (OR, 5.27; 95%CI, 1.86–14.90) were significantly positively associated with the CIRS score. Individuals with high school (OR, 2.61; 95%CI, 1.13–6.05) and college (OR, 3.02; 95%CI, 1.13–8.04) degrees obtained higher scores in the survey than those with elementary school education. Results indicated that utilization of resources and support for chronic illness self-management, particularly personal adjustment and organization, were not ideal among diabetics in the communities of north-western China. Improved utilization of chronic illness resources was conducive for proper diabetes self-management. Furthermore, the level of utilization of chronic illness resources increased with age, literacy level, and monthly income.

关键词： chronic illness resources survey     diabetes     community     north-western China    

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GROUNDWATER DEPLETION IN THE NORTH CHINA PLAIN: THE AGROHYDROLOGICAL PERSPECTIVE

《农业科学与工程前沿（英文）》 2021年 第8卷 第4期   页码 594-598 doi: 10.15302/J-FASE -2021407

摘要：

Agricultural production in the North China Plain with rainfall of less than 500 mm·yr−1 has been steadily increasing over the past 40 years, with the groundwater levels decreasing at a rate of over 1 m·yr−1. In this paper, it is demonstrated theoretically that the water level in the aquifer can be expressed as a function of agricultural production and the sum of water added as rainfall and imported from outside the basin. Therefore, the most effective measures to halt groundwater depletion are importing water, decreasing cropping intensity and growing less thirsty crops. Irrigation improvements, mulching and agronomic measures that could increase the yield per unit area have less of an impact on solving the declining groundwater levels.

 

关键词： crop yield / groundwater depletion / sustainability    

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Current status of municipal wastewater treatment plants in North-east China: implications for reforming

《环境科学与工程前沿（英文）》 2023年 第17卷 第6期 doi: 10.1007/s11783-023-1673-5

摘要：

● The performance and costs of 20 municipal WWTPs were analyzed.

关键词： Low temperature     Municipal WWTPs     Cold region     Electricity consumption     Nitrogen removal    

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我国北方地区水资源合理配置与南水北调

潘家铮

《中国工程科学》 2000年 第2卷 第10期   页码 26-32

摘要：

根据我国的水资源状况及可持续发展的需要，从水量丰富的长江流域引水北上的南水北调工程是势在必行和可以做到的。南水北调的原则应是：建立节水型社会，以供定需；合理配置，注意挖潜；东线、中线相辅相成，并非有我无他；编制概算实事求是，力戒“上马概算”；局部利益服从整体利益，暂时利益服从长远利益；坚持水资源统一管理，科学调配，有偿使用；西南调水不现实，宜暂缓。

关键词： 水资源     可持续发展     南水北调    

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Basic research on machinery fault diagnostics: Past, present, and future trends

Xuefeng CHEN, Shibin WANG, Baijie QIAO, Qiang CHEN

《机械工程前沿（英文）》 2018年 第13卷 第2期   页码 264-291 doi: 10.1007/s11465-018-0472-3

摘要：

Machinery fault diagnosis has progressed over the past decades with the evolution of machineries in terms of complexity and scale. High-value machineries require condition monitoring and fault diagnosis to guarantee their designed functions and performance throughout their lifetime. Research on machinery Fault diagnostics has grown rapidly in recent years. This paper attempts to summarize and review the recent R&D trends in the basic research field of machinery fault diagnosis in terms of four main aspects: Fault mechanism, sensor technique and signal acquisition, signal processing, and intelligent diagnostics. The review discusses the special contributions of Chinese scholars to machinery fault diagnostics. On the basis of the review of basic theory of machinery fault diagnosis and its practical applications in engineering, the paper concludes with a brief discussion on the future trends and challenges in machinery fault diagnosis.

关键词： fault diagnosis     fault mechanism     feature extraction     signal processing     intelligent diagnostics    

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Machine learning for fault diagnosis of high-speed train traction systems: A review

《工程管理前沿（英文）》 doi: 10.1007/s42524-023-0256-2

摘要： High-speed trains (HSTs) have the advantages of comfort, efficiency, and convenience and have gradually become the mainstream means of transportation. As the operating scale of HSTs continues to increase, ensuring their safety and reliability has become more imperative. As the core component of HST, the reliability of the traction system has a substantially influence on the train. During the long-term operation of HSTs, the core components of the traction system will inevitably experience different degrees of performance degradation and cause various failures, thus threatening the running safety of the train. Therefore, performing fault monitoring and diagnosis on the traction system of the HST is necessary. In recent years, machine learning has been widely used in various pattern recognition tasks and has demonstrated an excellent performance in traction system fault diagnosis. Machine learning has made considerably advancements in traction system fault diagnosis; however, a comprehensive systematic review is still lacking in this field. This paper primarily aims to review the research and application of machine learning in the field of traction system fault diagnosis and assumes the future development blueprint. First, the structure and function of the HST traction system are briefly introduced. Then, the research and application of machine learning in traction system fault diagnosis are comprehensively and systematically reviewed. Finally, the challenges for accurate fault diagnosis under actual operating conditions are revealed, and the future research trends of machine learning in traction systems are discussed.

关键词： high-speed train     traction systems     machine learning     fault diagnosis    

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Acoustic fault signal extraction via the line-defect phononic crystals

《机械工程前沿（英文）》 2022年 第17卷 第1期   页码 10-10 doi: 10.1007/s11465-021-0666-y

摘要： Rotating machine fault signal extraction becomes increasingly important in practical engineering applications. However, fault signals with low signal-to-noise ratios (SNRs) are difficult to extract, especially at the early stage of fault diagnosis. In this paper, 2D line-defect phononic crystals (PCs) consisting of periodic acrylic tubes with slit are proposed for weak signal detection. The defect band, namely, the formed resonance band of line-defect PCs enables the incident acoustic wave at the resonance frequency to be trapped and enhanced at the resonance cavity. The noise can be filtered by the band gap. As a result, fault signals with high SNRs can be obtained for fault feature extraction. The effectiveness of weak harmonic and periodic impulse signal detection via line-defect PCs are investigated in numerical and experimental studies. All the numerical and experimental results indicate that line-defect PCs can be well used for extracting weak harmonic and periodic impulse signals. This work will provide potential for extracting weak signals in many practical engineering applications.

关键词： phononic crystals     line-defect     fault signal extraction     acoustic enhancement    

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Pollution of NPEOs in four municipal sewage treatment plants in the north of China

HOU Shaogang, SUN Hongwen

《环境科学与工程前沿（英文）》 2007年 第1卷 第2期   页码 196-201 doi: 10.1007/s11783-007-0034-0

摘要： The concentration and distribution of nonylphenol polyethoxylates (NPEOs represents the mixture, and NPEO represents the monomer) and its metabolites in the influent and effluent of four municipal sewage treatment plants (STPs) in the north of China were measured. Moreover, the concentration and distribution of the above chemicals in the sludge of two STPs were also determined, and the transfer and fate of NPEOs in the sewage treatment process were discussed primarily by analyzing the distribution of the products in the effluent and the sludge. The results showed that NPEOs and its metabolites existed in all the samples of the influent, effluent, and sludge. NPEOs were degraded in the sewage treatment process with the removal efficiency in the range of 23.38% 77.11%, or an average of 52.86%. However, the large analogs of NPEO were only degraded to small ones, whose degradation rate was rather slow, and consequently the degradation was not complete. Hence, the concentrations of some small metabolites, such as nonylphenol (NP), nonylphenol monoethoxylate (NP1EO), and nonylphenol diethoxylate (NP2EO) were elevated in the effluent. These small metabolites are more toxic than the large NPnEO analogs, and some of them were reported to exhibit environmental endocrine disrupting activity. From this point of view, the process of sewage treatment does not reduce but elevate the risk of NPEOs, which becomes the main source of these small NPEO in the environment. The sludge exhibited good adsorption ability for NPEOs, especially for the small analogs, which led to the high level of NPEOs in the sludge. Hence, reasonable disposal of the surplus sludge to avoid re-pollution is very important.
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Iterative HOEO fusion strategy: a promising tool for enhancing bearing fault feature

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0725-z

摘要： As parameter independent yet simple techniques, the energy operator (EO) and its variants have received considerable attention in the field of bearing fault feature detection. However, the performances of these improved EO techniques are subjected to the limited number of EOs, and they cannot reflect the non-linearity of the machinery dynamic systems and affect the noise reduction. As a result, the fault-related transients strengthened by these improved EO techniques are still subject to contamination of strong noises. To address these issues, this paper presents a novel EO fusion strategy for enhancing the bearing fault feature nonlinearly and effectively. Specifically, the proposed strategy is conducted through the following three steps. First, a multi-dimensional information matrix (MDIM) is constructed by performing the higher order energy operator (HOEO) on the analysis signal iteratively. MDIM is regarded as the fusion source of the proposed strategy with the properties of improving the signal-to-interference ratio and suppressing the noise in the low-frequency region. Second, an enhanced manifold learning algorithm is performed on the normalized MDIM to extract the intrinsic manifolds correlated with the fault-related impulses. Third, the intrinsic manifolds are weighted to recover the fault-related transients. Simulation studies and experimental verifications confirm that the proposed strategy is more effective for enhancing the bearing fault feature than the existing methods, including HOEOs, the weighting HOEO fusion, the fast Kurtogram, and the empirical mode decomposition.

关键词： higher order energy operator     fault diagnosis     manifold learning     rolling element bearing     information fusion    

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标题 作者 时间 类型 操作

Finite element simulation for elastic dislocation of the North-Tehran fault: The effects of geologic

Pooya ZAKIAN; Hossein ASADI HAYEH

期刊论文

Application of random set method in a deep excavation: based on a case study in Tehran cemented alluvium

Arash SEKHAVATIAN, Asskar Janalizadeh CHOOBBASTI

期刊论文

Estimation of environmental effects of photovoltaic generation in North-west China

Mengjia REN, Anastasia SHCHERBAKOVA

期刊论文

南水北调工程

Office of the South-to-North Water Diversion Project Construction Committee, State Council, PRC

期刊论文

Three-dimensional finite difference analysis of shallow sprayed concrete tunnels crossing a reverse faultor a normal fault: A parametric study

Masoud RANJBARNIA, Milad ZAHERI, Daniel DIAS

期刊论文

Quantitative standard of eco-compensation for the water source area in the middle route of the South-to-North

Zhanfeng DONG, Jinnan WANG

期刊论文

Perceived resource support for chronic illnesses among diabetics in north-western China

null

期刊论文

GROUNDWATER DEPLETION IN THE NORTH CHINA PLAIN: THE AGROHYDROLOGICAL PERSPECTIVE

期刊论文

Current status of municipal wastewater treatment plants in North-east China: implications for reforming

期刊论文

我国北方地区水资源合理配置与南水北调

潘家铮

期刊论文

Basic research on machinery fault diagnostics: Past, present, and future trends

Xuefeng CHEN, Shibin WANG, Baijie QIAO, Qiang CHEN

期刊论文

Machine learning for fault diagnosis of high-speed train traction systems: A review

期刊论文

Acoustic fault signal extraction via the line-defect phononic crystals

期刊论文

Pollution of NPEOs in four municipal sewage treatment plants in the north of China

HOU Shaogang, SUN Hongwen

期刊论文

Iterative HOEO fusion strategy: a promising tool for enhancing bearing fault feature

期刊论文