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The ecological system and the regionalization of landscape reconstruction in northwest of China

Peicheng LI,Guoyuan DU,Qilei LI,Jinfeng WANG,Feimin ZHENG

《农业科学与工程前沿(英文)》 2014年 第1卷 第4期   页码 291-298 doi: 10.15302/J-FASE-2014033

摘要: The northwest of China is a vast area with abundant resources and significant potential for development. However, the ecological system is extremely vulnerable to damage and must be managed carefully. Thus, the Chinese government is strengthening research on improvement and reconstruction of the ecological system and landscape in northwest of China while moving forward with large-scale development in west China. The disadvantages and vulnerabilities in the northwest area in China are presented. It is suggested that the reconstruction of landscape should be conducted by step by step regionalization across the various ecological systems in the 3.04 million km northwest area of China. The first level regionalization results of reconstruction of landscape are discussed.

关键词: reconstruction of landscape     ecological system     the northwest area of China     science and technology action    

Social media and mobility landscape: Uncovering spatial patterns of urban human mobility with multi source

Yilan Cui, Xing Xie, Yi Liu

《环境科学与工程前沿(英文)》 2018年 第12卷 第5期 doi: 10.1007/s11783-018-1068-1

摘要:

Check-in and survey data are explored to identify personal activity-specific places.

Ways for detecting and moderating sample bias of Weibo check-in data is proposed.

A graphic representation of urban activity intensity in Beijing, China is presented.

The potential application of Weibo check-in data for urban analysis is introduced.

关键词: Social media     Human mobility     Population bias     Sample reconstruction     Data integration    

Research on a quantificational method for chromatic-light emotions of architectural wall coatings in landscape

Ting WANG, Ma JIAN, Gang LIU, Xiaoxi LIU, Mingyu ZHANG

《结构与土木工程前沿(英文)》 2010年 第4卷 第4期   页码 498-502 doi: 10.1007/s11709-010-0096-0

摘要: Research on quantificational methods for chromatic-light emotion is an effective way of finding out the laws of light cognitive impact and the solution to the problem on application of light color in landscape lighting. This paper took chromatic-light-induced-emotion towards architectural wall coatings in landscape as the research object. The methods in use were real-state simulation and laboratory quantitative study. Consequently, the study successfully extracted light emotional factors and the rule of predictability to assist landscape light professionals.

关键词: landscape illumination     architectural wall coatings     chromatic-light emotion     quantitative research    

Isogeometric analysis based on geometric reconstruction models

《机械工程前沿(英文)》 2021年 第16卷 第4期   页码 782-797 doi: 10.1007/s11465-021-0648-0

摘要: In isogeometric analysis (IGA), the boundary representation of computer-aided design (CAD) and the tensor-product non-uniform rational B-spline structure make the analysis of three-dimensional (3D) problems with irregular geometries difficult. In this paper, an IGA method for complex models is presented by reconstructing analysis-suitable models. The CAD model is represented by boundary polygons or point cloud and is embedded into a regular background grid, and a model reconstruction method is proposed to obtain the level set function of the approximate model, which can be directly used in IGA. Three 3D examples are used to test the proposed method, and the results demonstrate that the proposed method can deal with complex engineering parts reconstructed by boundary polygons or point clouds.

关键词: isogeometric analysis     reconstruction model     level set function     trimmed element     point cloud    

FLOWERING PLANTS AND ENTOMOPHAGOUS ARTHROPODS IN THE AGRICULTURAL LANDSCAPE: A PRACTISE-ORIENTED SUMMARY

《农业科学与工程前沿(英文)》 2022年 第9卷 第1期   页码 63-74 doi: 10.15302/J-FASE-2021427

摘要:

There is a growing demand for high-quality agricultural products and more countries have adopted landscape management by sowing flowering plants in agricultural fields as an important branch of conservation biological control. However, there has been less concern over the interactions and trade-offs between floral plants and entomophagous arthropods. This paper review progress in pollen/nectar feeding habits of entomophagous insects including parasitoids and predators which are important natural enemies of crop pests in agricultural fields. Factors that influence the preference of different guilds of natural enemies are reviewed to guide the selection of flowering plants in conservation biological control practices. Most studies find that floral resources have positive effects on both biological traits of natural enemies and their abundance and diversity, and this is believed to contribute greatly to pest control. Furthermore, the potential impacts of floral resources on crop yields are also discussed with an emphasis on a guild of entomophagous insects that provides both pest control and pollination services.

 

关键词: ecosystem services / flowering plants / natural enemies / nectar / pollen    

of texture and irrigation on the soil moisture vertical-temporal variability in an urban artificial landscape

Xiaofeng ZHANG,Xu ZHANG,Guanghe LI

《环境科学与工程前沿(英文)》 2015年 第9卷 第2期   页码 269-278 doi: 10.1007/s11783-014-0672-y

摘要: Soil moisture variability in natural landscapes has been widely studied; however, less attention has been paid to its variability in the urban landscapes with respect to the possible influence of texture stratification and irrigation management. Therefore, a case study was carried out in the Beijing Olympic Forest Park to continuously monitor the soil in three typical profiles from 26 April to 11 November 2010. The texture stratification significantly affected the vertical distribution of moisture in the non-irrigated profile where moisture was mostly below field capacity. In the profile where irrigation was sufficient to maintain moisture above field capacity, gravity flow led to increased moisture with depth and thus eliminated the influence of texture. In the non-irrigated sites, the upper layer (above 80 cm) exhibited long-term moisture persistence with the time scale approximating the average rainfall interval. However, a coarse-textured layer weakened the influence of rainfall, and a fine-textured layer weakened the influence of evapotranspiration, both of which resulted in random noise-like moisture series in the deeper layers. At the irrigated site, frequent irrigation neutralized the influence of evapotranspiration in the upper layer (above 60 cm) and overshadowed the influence of rainfall in the deeper layer. As a result, the moisture level in the upper layer also behaved as a random noise-like series; whereas due to deep transpiration, the moisture of the deep layer had a persistence time-scale longer than a month, consistent with characteristic time-scales found for deep transpiration.

关键词: moisture vertical distribution     moisture temporal variation     texture stratification     irrigation     meteorological forcing     urban landscape    

Fractal characteristic evaluation and interpolation reconstruction for surface topography of drilled

《机械工程前沿(英文)》 2021年 第16卷 第4期   页码 840-854 doi: 10.1007/s11465-021-0643-5

摘要: In this paper, an improved fractal interpolation model is proposed to reconstruct the surface topography of composite hole wall. This model adopts the maximum positive deviations and maximum negative deviations between the measured values and trend values to determine the contraction factors. Hole profiles in 24 directions are measured. Fractal parameters are calculated to evaluate the measured surface profiles. The maximum and minimum fractal dimension of the hole wall are 1.36 and 1.07, whereas the maximum and minimum fractal roughness are 4.05 × 10 −5 and 4.36 × 10 −10 m, respectively. Based on the two-dimensional evaluation results, three-dimensional surface topographies in five typical angles (0°, 45°, 90°, 135°, and 165°) are reconstructed using the improved model. Fractal parameter D s and statistical parameters Sa, Sq, and Sz are used to evaluate the reconstructed surfaces. Average error of D s, Sa, Sq, and Sz between the measured surfaces and the reconstructed surfaces are 1.53%, 3.60%, 5.60%, and 9.47%, respectively. Compared with the model in published literature, the proposed model has equal reconstruction effect in relatively smooth surface and is more advanced in relatively rough surface. Comparative results prove that the proposed model for calculating contraction factors is more reasonable.

关键词: surface topography     fractal evaluation     fractal interpolation     reconstruction     composite    

nitrogen/phosphorus concentration and hydraulic retention time for bloom control in reclaimed water landscape

《环境科学与工程前沿(英文)》 2022年 第16卷 第10期 doi: 10.1007/s11783-022-1564-1

摘要:

● A new model for bloom control in open land scape water was constructed.

关键词: Reclaimed water landscape     Algal bloom     Nitrogen and phosphorus     Hydraulic retention time     Threshold     Control model    

Analysis of the genomic landscape of primary central nervous system lymphoma using whole-genome sequencing

《医学前沿(英文)》   页码 889-906 doi: 10.1007/s11684-023-0994-x

摘要: Primary central nervous system lymphoma (PCNSL) is an uncommon non-Hodgkin’s lymphoma with poor prognosis. This study aimed to depict the genetic landscape of Chinese PCNSLs. Whole-genome sequencing was performed on 68 newly diagnosed Chinese PCNSL samples, whose genomic characteristics and clinicopathologic features were also analyzed. Structural variations were identified in all patients with a mean of 349, which did not significantly influence prognosis. Copy loss occurred in all samples, while gains were detected in 77.9% of the samples. The high level of copy number variations was significantly associated with poor progression-free survival (PFS) and overall survival (OS). A total of 263 genes mutated in coding regions were identified, including 6 newly discovered genes (ROBO2, KMT2C, CXCR4, MYOM2, BCLAF1, and NRXN3) detected in ≥ 10% of the cases. CD79B mutation was significantly associated with lower PFS, TMSB4X mutation and high expression of TMSB4X protein was associated with lower OS. A prognostic risk scoring system was also established for PCNSL, which included Karnofsky performance status and six mutated genes (BRD4, EBF1, BTG1, CCND3, STAG2, and TMSB4X). Collectively, this study comprehensively reveals the genomic landscape of newly diagnosed Chinese PCNSLs, thereby enriching the present understanding of the genetic mechanisms of PCNSL.

关键词: primary central nervous system lymphoma     whole-genome sequencing     TMSB4X     copy number variation     gene mutation    

以东为鉴 秀丽晚成——西部风景园林开发浅议

孟兆祯

《中国工程科学》 2000年 第2卷 第10期   页码 56-58

摘要:

首先我们要站在人类社会生产与自然环境协调的可持续发展的高度着手综合的国土规划,建立从总体到单体的规划设计科学序列。现阶段城市的本质应为人类聚居并藉以生存的生活环境。城市化进程与自然环境间并非针锋相对的破坏关系。城市形象不仅仅是建筑加道路的形象,而是以人工美入自然,将城市和建筑融汇到自然环境中的形象。我们美好的前景是将城市和建筑建在绿色环境中。风景名胜区和城市园林的建设当前仍须将保护自然资源放在首位。要创造特色,从各市的自然环境和人文脉络中捕捉城市风景园林的特色,不要盲目跟风。秀丽山川,大器晚成。扎实积累,功到必成。

关键词: 城市化进程     风景名胜区     城市园林    

Full-field dynamic strain reconstruction of an aero-engine blade from limited displacement responses

《机械工程前沿(英文)》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0731-1

摘要: Blade strain distribution and its change with time are crucial for reliability analysis and residual life evaluation in blade vibration tests. Traditional strain measurements are achieved by strain gauges (SGs) in a contact manner at discrete positions on the blades. This study proposes a method of full-field and real-time strain reconstruction of an aero-engine blade based on limited displacement responses. Limited optical measured displacement responses are utilized to reconstruct the full-field strain. The full-field strain distribution is in-time visualized. A displacement-to-strain transformation matrix is derived on the basis of the blade mode shapes in the modal coordinate. The proposed method is validated on an aero-engine blade in numerical and experimental cases. Three discrete vibrational displacement responses measured by laser triangulation sensors are used to reconstruct the full-field strain over the whole operating time. The reconstructed strain responses are compared with the results measured by SGs and numerical simulation. The high consistency between the reconstructed and measured results demonstrates the accurate strain reconstructed by the method. This paper provides a low-cost, real-time, and visualized measurement of blade full-field dynamic strain using displacement response, where the traditional SGs would fail.

关键词: aero-engine blade     displacement response     dynamic strain reconstruction     mode shape     strain gauge    

Shape reconstruction of parallelogram flaw

ZHENG Gangfeng, WU Bin, HE Cunfu

《机械工程前沿(英文)》 2008年 第3卷 第1期   页码 17-22 doi: 10.1007/s11465-008-0015-4

摘要: To reconstruct the shape of the scatterer in elastic media, the authors deduce the Born approximation solution of the two-dimensional scattering problem, which includes the shape factor that embodies all information about the shape of the scatterer. Accordingly, the change in the shape of the scatterer only necessitates the number of the corresponding new shape factors. For a parallelogram void in a long Al rod, its shape factor can be obtained. In view of the definition of a characteristic function, the shape factor has a corresponding integral representation. Obviously, the shape factor can be considered as a Fourier transform of the characteristic function, which is reconstructed from the inverse Fourier transform. The integral equation is considered as the basic equation to reconstruct the shape of the scatterer. The identification of the geometrical character of a flaw is then given by the two dimensional inverse Born approximation in a low-frequency range. For the parallelogram void, a theoretical calculating identification is performed. At the same time, the numerical results are obtained by the finite element method.

关键词: approximation     scatterer     scattering problem     information     inverse    

Extrapolation reconstruction of wind pressure fields on the claddings of high-rise buildings

Yehua SUN, Guquan SONG, Hui LV

《结构与土木工程前沿(英文)》 2019年 第13卷 第3期   页码 653-666 doi: 10.1007/s11709-018-0503-5

摘要: Recent research about reconstruction methods mainly used the interpolation reconstruction of the fluctuating wind pressure field on the surface. However, to investigate wind pressure at the edge of the building, the work presented in this paper focuses on the extrapolation reconstruction of wind pressure fields. Here, we propose an improved proper orthogonal decomposition (POD) and Kriging method with a von Kármán correlation function to resolve this issue. The studies show that it works well for not only interpolation reconstruction but also extrapolation reconstruction. The proposed method does require determination of the Hurst exponent and other parameters analysed from the original data. Hence, the fluctuating wind fields have been characterized by the von Kármán correlation function, as an a priori function. Compared with the cubic spline method and different variogram, preliminary results suggest less time consumption and high efficiency in extrapolation reconstruction at the edge.

关键词: extrapolation reconstruction     proper orthogonal decomposition     Kriging method     von Kármán function     Hurst exponent     rescaled range analysis    

From understanding to designing soundscapes

Jian KANG

《结构与土木工程前沿(英文)》 2010年 第4卷 第4期   页码 403-417 doi: 10.1007/s11709-010-0091-5

摘要: Soundscape represents a step change in the field of environmental acoustics in that it combines physical, social, and psychological approaches. Although the term soundscape was introduced in the 1960s, significant attention to it has mainly been paid in the last decade or so in the community of environmental acoustics by researchers and recently by practitioners including policy makers. This paper explores the current situation and future challenges in soundscape. Starting with a framework on research and practical needs in soundscape and a brief introduction of some recent/current networks, activities, projects, and publications, this paper then presents a systematic review of recent progress in soundscape research and practice. A short review of the soundscape research in China is also given.

关键词: soundscape     environment     sound     design     urban     landscape    

A dynamic stiffness-based framework for harmonic input estimation and response reconstruction considering

Yixian LI; Limin SUN; Wang ZHU; Wei ZHANG

《结构与土木工程前沿(英文)》 2022年 第16卷 第4期   页码 448-460 doi: 10.1007/s11709-022-0805-5

摘要: In structural health monitoring (SHM), the measurement is point-wise but structures are continuous. Thus, input estimation has become a hot research subject with which the full-field structural response can be calculated with a finite element model (FEM). This paper proposes a framework based on the dynamic stiffness theory, to estimate harmonic input, reconstruct responses, and to localize damages from seriously deficient measurements. To begin, Fourier transform converts the dynamic equilibrium equation to an equivalent static one in the frequency domain, which is under-determined since the dimension of measurement vector is far less than the FEM-node number. The principal component analysis has been adopted to “compress” the under-determined equation, and formed an over-determined equation to estimate the unknown input. Then, inverse Fourier transform converts the estimated input in the frequency domain to the time domain. Applying this to the FEM can reconstruct the target responses. If a structure is damaged, the estimated nodal force can localize the damage. To improve the damage-detection accuracy, a multi-measurement-based indicator has been proposed. Numerical simulations have validated that the proposed framework can capably estimate input and reconstruct multi-types of full-field responses, and the damage indicator can localize minor damages even with the existence of noise.

关键词: dynamic stiffness     principal component analysis     response reconstruction     damage localization     under-determined equation    

标题 作者 时间 类型 操作

The ecological system and the regionalization of landscape reconstruction in northwest of China

Peicheng LI,Guoyuan DU,Qilei LI,Jinfeng WANG,Feimin ZHENG

期刊论文

Social media and mobility landscape: Uncovering spatial patterns of urban human mobility with multi source

Yilan Cui, Xing Xie, Yi Liu

期刊论文

Research on a quantificational method for chromatic-light emotions of architectural wall coatings in landscape

Ting WANG, Ma JIAN, Gang LIU, Xiaoxi LIU, Mingyu ZHANG

期刊论文

Isogeometric analysis based on geometric reconstruction models

期刊论文

FLOWERING PLANTS AND ENTOMOPHAGOUS ARTHROPODS IN THE AGRICULTURAL LANDSCAPE: A PRACTISE-ORIENTED SUMMARY

期刊论文

of texture and irrigation on the soil moisture vertical-temporal variability in an urban artificial landscape

Xiaofeng ZHANG,Xu ZHANG,Guanghe LI

期刊论文

Fractal characteristic evaluation and interpolation reconstruction for surface topography of drilled

期刊论文

nitrogen/phosphorus concentration and hydraulic retention time for bloom control in reclaimed water landscape

期刊论文

Analysis of the genomic landscape of primary central nervous system lymphoma using whole-genome sequencing

期刊论文

以东为鉴 秀丽晚成——西部风景园林开发浅议

孟兆祯

期刊论文

Full-field dynamic strain reconstruction of an aero-engine blade from limited displacement responses

期刊论文

Shape reconstruction of parallelogram flaw

ZHENG Gangfeng, WU Bin, HE Cunfu

期刊论文

Extrapolation reconstruction of wind pressure fields on the claddings of high-rise buildings

Yehua SUN, Guquan SONG, Hui LV

期刊论文

From understanding to designing soundscapes

Jian KANG

期刊论文

A dynamic stiffness-based framework for harmonic input estimation and response reconstruction considering

Yixian LI; Limin SUN; Wang ZHU; Wei ZHANG

期刊论文