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Independent cover meshless particle method for complex geotechnical engineering

Jianqiu WU, Yongchang CAI

《结构与土木工程前沿(英文)》 2018年 第12卷 第4期   页码 515-526 doi: 10.1007/s11709-017-0428-4

摘要: A new Independent Cover Meshless Particle (ICMP) method is proposed for the analysis of complex geotechnical engineering. In the ICMP method, the independent rectangular cover regardless of the shape of the analysis model is employed as the influence domain of each discrete node, the general polynomial is employed as the meshless interpolation function of the independent nodal cover, and the Cartesian Transformation Method (CTM) is used for the numerical integration of the nodal covers cut by material interfaces, joints, cracks and faults. The present method has a simple formulation and a low computational cost, and is easy for the numerical analysis and modeling of complex geotechnical engineering. Several typical numerical examples are presented to demonstrate the accuracy and robustness of the proposed method.

关键词: meshless method     particle method     independent cover     CTM     geotechnical engineering    

Evaluating effect of chloride attack and concrete cover on the probability of corrosion

Sanjeev Kumar VERMA, Sudhir Singh BHADAURIA, Saleem AKHTAR

《结构与土木工程前沿(英文)》 2013年 第7卷 第4期   页码 379-390 doi: 10.1007/s11709-013-0223-9

摘要: Corrosion of reinforced concrete (RC) structures is one of the significant causes of deterioration of reinforced concrete (RC) structures. Chlorination is a major process governing the initiation and advancement of the injurious corrosion of steel bars. Now, several researches on the chlorination of concrete structures have been ongoing around the world. Present article reviews several recently performed chlorination studies, and from results of a field survey evaluates the effect of chloride content on the probability of corrosion and the influence of concrete compressive strength on the chloride content and penetration, also evaluates the effect of concrete cover over the chloride content of the RC structures at rebar depth and on the probability of corrosion.

关键词: concrete     chloride     reinforcement     corrosion     deterioration     cover    

Industrial development and land use/cover change and their effects on local environment: a case study

Yurui LI, Hualou LONG, Yansui LIU

《环境科学与工程前沿(英文)》 2010年 第4卷 第4期   页码 438-448 doi: 10.1007/s11783-010-0273-3

摘要: The interactions among industrial development, land use/cover change (LUCC), and environmental effects in Changshu in the eastern coastal China were analyzed using high-resolution Landsat TM data in 1990, 1995, 2000, and 2006, socio-economic data and water environmental quality monitoring data from research institutes and governmental departments. Three phases of industrial development in Changshu were examined (i.e., the three periods of 1990 to 1995, 1995 to 2000, and 2000 to 2006). Besides industrial development and rapid urbanization, land use/cover in Changshu had changed drastically from 1990 to 2006. This change was characterized by major replacements of farmland by urban and rural settlements, artificial ponds, forested and constructed land. Industrialization, urbanization, agricultural structure adjustment, and rural housing construction were the major socio-economic driving forces of LUCC in Changshu. In addition, the annual value of ecosystem services in Changshu decreased slightly during 1990–2000, but increased significantly during 2000–2006. Nevertheless, the local environmental quality in Changshu, especially in rural areas, has not yet been improved significantly. Thus, this paper suggests an increased attention to fully realize the role of land supply in adjustment of environment-friendly industrial structure and urban-rural spatial restructuring, and translating the land management and environmental protection policies into an optimized industrial distribution and land-use pattern.

关键词: industrial development     land use/cover change (LUCC)     driving forces     environmental effects     ecosystem services value (ESV)     water environmental quality     Changshu    

Effect of land use and land cover change on soil erosion and the spatio-temporal variation in Liupan

Bin QUAN, M. J. M. R?MKENS, Rui LI, Fang WANG, Jie CHEN

《环境科学与工程前沿(英文)》 2011年 第5卷 第4期   页码 564-572 doi: 10.1007/s11783-011-0348-9

摘要: The Liupan Mountains are located in the southern Ningxia Hui Autonomous Region of China, that forms an important divide between landforms and bio-geographic regions. The populated part of the Liupan Mountain Region has suffered tremendous ecological damage over time due to population pressure, excessive demand and inappropriate use of agricultural land resources. To present the relationship between land use/cover change and spatio-temporal variation of soil erosion, data sets of land use between the late 1980s and 2000 were obtained from Landsat Thematic Mapper (TM) imagery, and spatial models were used to characterize landscape and soil erosion conditions. Also, soil erosion in response to land use and land cover change were quantified and analyzed using data from geographical information systems and remote sensing. Soil erosion by water was the dominant mode of soil loss, while soil erosion by wind was only present on a relatively small area. The degree of soil erosion was classified into five severity classes: slight, light, moderate, severe, and very severe. Soil erosion in the Liupan Mountain Region increased between the late 1980s and 2000, both in terms of acreage and severity. Moderate, severe, and very severe eroded areas accounted for 54.86% of the total land area. The lightly eroded area decreased, while the moderately eroded area increased by 368817 ha (22%) followed by severe erosion with 146552 ha (8.8%), and very severe erosion by 97067.6 ha (5.8%). Soil loss on sloping cropland increased with slope gradients. About 90% of the cropland was located on slopes less than 15°. Most of the increase in soil erosion on cropland was due to conversion of steep slopes to cropland and degradation of grassland and increased activities. Soil erosion was severe on grassland with a moderate or low grass cover and on dry land. Human activities, cultivation on steep slopes, and overgrazing of pastures were the main reasons for the increase in erosion severity.

关键词: land use/land cover change     soil erosion     geographical information system     remote sensing     Liupan Mountain Region    

基于抗浮稳定的盾构隧道合理覆土厚度研究

刘学彦,袁大军,姜 曦

《中国工程科学》 2015年 第17卷 第1期   页码 88-95

摘要:

运用理论分析和数值计算相结合的方法,分别从施工期和运营期角度提出了隧道抗浮稳定合理覆土厚度设定原则和理论计算方法;对于隧道施工期,考虑土体侧向摩阻力和管片环间摩阻力的影响等较为有利因素,同时考虑未凝浆液的影响等不利因素,建立了合理覆土厚度的理论计算公式;对于隧道运营期,建议只考虑隧道上覆土体自重进行抗浮,对于存在洪水冲刷的隧道设计,其上覆土体厚度还要加上设计冲刷深度;为南京某在建隧道的纵断面设计提供了一定的参考,同时也为其他过江海盾构隧道满足抗浮稳定的覆土厚度设定提供理论支持。

关键词: 抗浮安全;隧道施工期;隧道运营期;覆土厚度    

Land use/cover change effects on floods with different return periods: a case study of Beijing, China

Yueling WANG, Xiaoliu YANG

《环境科学与工程前沿(英文)》 2013年 第7卷 第5期   页码 769-776 doi: 10.1007/s11783-013-0542-z

摘要: In this study, an approach integrating digital land use/cover change (LUCC) analysis, hydraulic modeling and statistical methods was applied to quantify the effect of LUCC on floods in terms of inundation extent, flood arrival time and maximum water depth. The study took Beijing as an example and analyzed five specific floods with return periods of 20-year, 50-year, 100-year, 1000-year and 10000-year on the basis of LUCC over a nine-year period from 1996 to 2004. The analysis reveals that 1) during the period of analysis Beijing experienced unprecedented LUCC; 2) LUCC can affect inundation extent and flood arrival time, and floods with longer return periods are more influenced; 3) LUCC can affect maximum water depth and floods with shorter return periods are more influenced; and 4) LUCC is a major flood security stressor for Beijing. It warns that those cities having experienced rapid expansion during recent decades in China are in danger of more serious floods and recommends that their actual land use patterns should be carefully assessed considering flood security. This integrated approach is demonstrated to be a useful tool for joint assessment, planning and management of land and water.

关键词: inundation extent     flood arrival time     maximum water depth     shallow flow model    

Maximum independent set in planning freight railway transportation

Gainanov Damir N., Mladenovic NENAD, Rasskazova V. A.

《工程管理前沿(英文)》 2018年 第5卷 第4期   页码 499-506 doi: 10.15302/J-FEM-2018031

摘要:

This work is devoted to the problem of planning of freight railway transportation. We define a special conflict graph on the basis of a set of acceptable train routes. The investigation aims to solve the classical combinatorial optimization problem in relation to the maximum independent set of vertices in undirected graphs. The level representation of the graph and its tree are introduced. With use of these constructions, the lower and upper bounds for the number of vertices in the maximum independent set are obtained.

关键词: independent set     algorithm     planning of transportation     two-sided estimate    

Interaction and independence on methane oxidation of landfill cover soil among three impact factors:

Pinjing HE, Na YANG, Wenjuan FANG, Fan Lü, Liming SHAO

《环境科学与工程前沿(英文)》 2011年 第5卷 第2期   页码 175-185 doi: 10.1007/s11783-011-0320-8

摘要: To understand the influence patterns and interactions of three important environmental factors, i.e. soil water content, oxygen concentration, and ammonium addition, on methane oxidation, the soils from landfill cover layers were incubated under full factorial parameter settings. In addition to the methane oxidation rate, the quantities and community structures of methanotrophs were analyzed to determine the methane oxidation capacity of the soils. Canonical correspondence analysis was utilized to distinguish the important impact factors. Water content was found to be the most important factor influencing the methane oxidation rate and Type II methanotrophs, and the optimum value was 15% (w/w), which induced methane oxidation rates 10- and 6- times greater than those observed at 5% (w/w) and 20% (w/w), respectively. Ambient oxygen conditions were more suitable for methane oxidation than 3% oxygen. The addition of of ammonium induced different effects on methane oxidation capacity when conducted at low or high water content. With regard to the methanotrophs, Type II was sensitive to the changes of water content, while Type I was influenced by oxygen content. Furthermore, the methanotrophic acidophile, , was detected in soils with a pH of 4.9, which extended their known living environments.

关键词: quantitative polymerase chain reaction (PCR)     denaturing gradient gel electrophoresis (DGGE)     principal component analysis (PCA)     canonical correspondence analysis (CCA)    

自主开发——强国之道

金履忠

《中国工程科学》 2005年 第7卷 第7期   页码 1-6

摘要:

论证了自主开发在政治、军事、经济、安全、科技等方面的重大意义。建议用10~15年的时间,使我国的绝大多数产业具备自主开发和国际竞争能力;分析了实现这个目标是完全可能的。最后提出了应在思想观念、精神状态、法律法规、政策、体制、宣传舆论等方面创造有利于自主开发的环境。

关键词: 自主开发的重要性     实现的目标     可能性     营造自主开发的环境    

Fast removal of ocular artifacts from electroencephalogram signals using spatial constraint independent

Bang-hua YANG,Liang-fei HE,Lin LIN,Qian WANG

《信息与电子工程前沿(英文)》 2015年 第16卷 第6期   页码 486-496 doi: 10.1631/FITEE.1400299

摘要: Ocular artifacts cause the main interfering signals within electroencephalogram (EEG) signal measurements. An adaptive filter based on reference signals from an electrooculogram (EOG) can reduce ocular interference, but collecting EOG signals during a long-term EEG recording is inconvenient and uncomfortable for the subject. To remove ocular artifacts from EEG in brain-computer interfaces (BCIs), a method named spatial constraint independent component analysis based recursive least squares (SCICA-RLS) is proposed. The method consists of two stages. In the first stage, independent component analysis (ICA) is used to decompose multiple EEG channels into an equal number of independent components (ICs). Ocular ICs are identified by an automatic artifact detection method based on kurtosis. Then empirical mode decomposition (EMD) is employed to remove any cerebral activity from the identified ocular ICs to obtain exact artifact ICs. In the second stage, first, SCICA applies exact artifact ICs obtained in the first stage as a constraint to extract artifact ICs from the given EEG signal. These extracted ICs are called spatial constraint ICs (SC-ICs). Then the RLS based adaptive filter uses SC-ICs as reference signals to reduce interference, which avoids the need for parallel EOG recordings. In addition, the proposed method has the ability of fast computation as it is not necessary for SCICA to identify all ICs like ICA. Based on the EEG data recorded from seven subjects, the new approach can lead to average classification accuracies of 3.3% and 12.6% higher than those of the standard ICA and raw EEG, respectively. In addition, the proposed method has 83.5% and 83.8% reduction in time-consumption compared with the standard ICA and ICA-RLS, respectively, which demonstrates a better and faster OA reduction.

关键词: Ocular artifacts     Electroencephalogram (EEG)     Electrooculogram (EOG)     Brain-computer interface (BCI)     Spatial constraint independent component analysis based recursive least squares (SCICA-RLS)    

Topology-independent end-to-end learning model for improving the voltage profile in microgrids-integrated

《能源前沿(英文)》 2023年 第17卷 第2期   页码 211-227 doi: 10.1007/s11708-022-0847-3

摘要: With multiple microgrids (MGs) integrated into power distribution networks in a distributed manner, the penetration of renewable energy like photovoltaic (PV) power generation surges. However, the operation of power distribution networks is challenged by the issues of multiple power flow directions and voltage security. Accordingly, an efficient voltage control strategy is needed to ensure voltage security against ever-changing operating conditions, especially when the network topology information is absent or inaccurate. In this paper, we propose a novel data-driven voltage profile improvement model, denoted as system-wide composite adaptive network (SCAN), which depends on operational data instead of network topology details in the context of power distribution networks integrated with multiple MGs. Unlike existing studies that realize topology identification and decision-making optimization in sequence, the proposed end-to-end model determines the optimal voltage control decisions in one shot. More specifically, the proposed model consists of four modules, Pre-training Network and modified interior point methods with adversarial networks (Modified IPMAN) as core modules, and discriminator generative adversarial network (Dis-GAN) and Volt convolutional neural network (Volt-CNN) as ancillary modules. In particular, the generator in SCAN is trained by the core modules in sequence so as to form an end-to-end mode from data to decision. Numerical experiments based on IEEE 33-bus and 123-bus systems have validated the effectiveness and efficiency of the proposed method.

关键词: end-to-end learning     microgrids     voltage profile improvement     generative adversarial network    

Intra-abdominal hypertension is an independent cause of acute renal failure after orthotopic liver transplantation

SHU Ming, PENG Chenghong, CHEN Hao, SHEN Boyong, ZHOU Guangwen, SHEN Chuan, LI Hongwei

《医学前沿(英文)》 2007年 第1卷 第2期   页码 167-172 doi: 10.1007/s11684-007-0031-5

摘要: An independent association between acute renal failure (ARF) and intra-abdominal hypertension (IAH) after liver transplantation has not been established previously. The aim of this retrospective study was to understand the role of IAH as an independent risk factor for ARF in the early postoperative period. This study involved 62 subjects who underwent liver transplantation. Intra-abdominal pressure (IAP) was measured in the first three days after surgery by using the urinary bladder technique. An IAP of at least 20 mmHg per day was defined as IAH. Clinical parameters between group IAH and group NO-IAH were compared in terms of the incidence of ARF, blood creatinine levels, blood urea nitrogen (BUN) levels, urine volume per hour and glomerular filtration gradient (GFG). Hemodynamic variations were recorded in the first three postoperative days between group ARF and group NO-ARF. The perioperative suspected risk factors of ARF were determined for statistical evaluation using correlation coefficients and logistic regression analysis. In group IAH, 45.8% patients developed ARF as against 7.9% in group NO-IAH; GFG was significantly lower at 0 72 h after surgery; and blood creatinine levels, BUN levels, urine volume per hour were significantly different at 24 72 h after surgery compared with group NO-IAH. The patients with ARF were not significantly different from those without ARF in terms of central venous pressure, pulmonary artery pressure and mean arterial pressure (MAP) in the first three postoperative days despite a significant increase in heart rate at 24 72h after operation. Postoperative IAH, intraoperative MAP and intraoperative blood transfusion volume of more than 15 U were found to be independent risk factors for ARF. IAH impaired renal function and was an independent risk factor for ARF after liver transplantation. Routine measurement should be taken to monitor IAP every eight hours postoperatively.

G protein-coupled receptor LGR6 is an independent risk factor for colon adenocarcinoma

Wenjing Wang, Shigang Ding, Hejun Zhang, Jun Li, Jun Zhan, Hongquan Zhang

《医学前沿(英文)》 2019年 第13卷 第4期   页码 482-491 doi: 10.1007/s11684-018-0633-0

摘要: LGR6 is a member of the G protein-coupled receptor family that plays a tumor-suppressive role in colon cancer. However, the relationship between LGR6 expression in patients and clinicopathological factors remains unclear. This study aimed to clarify whether the expression level of LGR6 is correlated with colon adenocarcinoma progression. Immunohistochemistry was used to detect LGR6 expression in colon adenoma tissues ( = 21), colon adenocarcinoma tissues ( = 156), and adjacent normal tissues ( = 124). The expression levels of LGR6 in colon adenoma and adenocarcinoma were significantly higher than those in normal colon epithelial tissues ( <0.001). Low LGR6 expression predicted a short overall survival in patients with colon adenocarcinoma (log-rank test, = 0.016). Univariate and multivariate survival analyses showed that, in addition to N and M classification, LGR6 expression served as an independent prognostic factor. Thus, low expression of LGR6 can be used as an independent prognostic parameter in patients with colon adenocarcinoma.

关键词: LGR6     colon adenocarcinoma     immunohistochemistry     prognosis    

p53 functional activation is independent of its genotype in five esophageal squamous cell carcinoma cell

Junfang JI, Kun WU, Min WU, Qimin ZHAN,

《医学前沿(英文)》 2010年 第4卷 第4期   页码 412-418 doi: 10.1007/s11684-010-0260-x

摘要: mutations have been found in many esophageal squamous cell carcinoma (ESCC) clinical specimens and cell lines. We reasoned that functional inactivation of wild-type or the functional activation of mutant-type might exist in these specimens and cell lines. In this study, we identified the correlation between p53 functional activation and its genotype in five different ESCC cell lines. To examine the potential p53 activation in a certain ESCC cell line, DNA damage methods including X-ray exposure and cisplatin treatment were employed to treat cells. Further, the expression of p53 protein and four transcripts of well-known p53 target genes were investigated using Western blot and reverse transcription-polymerase chain reaction (RT-PCR) after cell exposure to DNA damage. The results showed that in KYSE 30 cell line with mutant and KYSE 150 with wild-type , p53 could be activated by DNA damages. However, p53 could not be activated following the DNA damages in YES 2 with wild-type , KYSE 70 with mutant , and EC9706 with unknown genotype. All our data indicated that p53 function in certain cells is not closely correlated with its genotype. To judge p53 function in a particular cell line, it is important to examine the p53 functional activation, but not to simply rely on the genotype.

关键词: p53     esophageal squamous cell carcinoma     DNA damage    

Independent continuous and mapping method of structural topology optimization based on the global stress

Yunkang SUI, Jili FENG, Hongling YE, Xirong PENG,

《机械工程前沿(英文)》 2010年 第5卷 第2期   页码 130-142 doi: 10.1007/s11465-010-0011-3

摘要: There are three difficulties in topology optimization of continuum structures. 1) The topology under multiple load case is more difficult to be optimized than under single load case, because the former becomes a multiple objective based on compliance objective functions. 2) With local constraints, such as an elemental stress limit, the topology is more difficult to be solved than with global constraints, such as the displacement or frequency limits, because the sensitivity analysis of the former has very expensive computation. 3) With the phenomenon of load illness, which is similar with stiffness illness in the structural analysis, it is not easy to get the reasonable final topological structure, because it is difficult to consider different influences between the loads with small forces and big forces, and some topology paths of transferring small forces may disappear during the iteration process. To overcome difficulties above, four measures are adopted. 1) Topology optimization model is established by independent continuous mapping (ICM) method. 2) Based on the von Mises strength theory, all elements’ stress constraints are transformed into a structural energy constraint. 3) The phenomenon of load illness is divided to classify into three cases. 4) A strategy based on strain energy is proposed to adopt ICM method with stress globalization, and the problems of the above mentioned three cases of load illness are solved in terms of different complementary approaches. Several numerical examples show that the topology path of transferring forces can be obtained more easily by substituting global strain energy constraints for local stresses constraints, and the problem of load illness can be solved well by the weighting method that takes the structural energy as a weighting coefficient.

关键词: independent continuous mapping (ICM) method     global stresses constraints     topology optimization     continuum structure     load illness    

标题 作者 时间 类型 操作

Independent cover meshless particle method for complex geotechnical engineering

Jianqiu WU, Yongchang CAI

期刊论文

Evaluating effect of chloride attack and concrete cover on the probability of corrosion

Sanjeev Kumar VERMA, Sudhir Singh BHADAURIA, Saleem AKHTAR

期刊论文

Industrial development and land use/cover change and their effects on local environment: a case study

Yurui LI, Hualou LONG, Yansui LIU

期刊论文

Effect of land use and land cover change on soil erosion and the spatio-temporal variation in Liupan

Bin QUAN, M. J. M. R?MKENS, Rui LI, Fang WANG, Jie CHEN

期刊论文

基于抗浮稳定的盾构隧道合理覆土厚度研究

刘学彦,袁大军,姜 曦

期刊论文

Land use/cover change effects on floods with different return periods: a case study of Beijing, China

Yueling WANG, Xiaoliu YANG

期刊论文

Maximum independent set in planning freight railway transportation

Gainanov Damir N., Mladenovic NENAD, Rasskazova V. A.

期刊论文

Interaction and independence on methane oxidation of landfill cover soil among three impact factors:

Pinjing HE, Na YANG, Wenjuan FANG, Fan Lü, Liming SHAO

期刊论文

自主开发——强国之道

金履忠

期刊论文

Fast removal of ocular artifacts from electroencephalogram signals using spatial constraint independent

Bang-hua YANG,Liang-fei HE,Lin LIN,Qian WANG

期刊论文

Topology-independent end-to-end learning model for improving the voltage profile in microgrids-integrated

期刊论文

Intra-abdominal hypertension is an independent cause of acute renal failure after orthotopic liver transplantation

SHU Ming, PENG Chenghong, CHEN Hao, SHEN Boyong, ZHOU Guangwen, SHEN Chuan, LI Hongwei

期刊论文

G protein-coupled receptor LGR6 is an independent risk factor for colon adenocarcinoma

Wenjing Wang, Shigang Ding, Hejun Zhang, Jun Li, Jun Zhan, Hongquan Zhang

期刊论文

p53 functional activation is independent of its genotype in five esophageal squamous cell carcinoma cell

Junfang JI, Kun WU, Min WU, Qimin ZHAN,

期刊论文

Independent continuous and mapping method of structural topology optimization based on the global stress

Yunkang SUI, Jili FENG, Hongling YE, Xirong PENG,

期刊论文