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Article ; Online: Highly sensitive ultrasound detection using nanofabricated polymer micro-ring resonators

Youngseop Lee / Hao F. Zhang / Cheng Sun

Nano Convergence, Vol 10, Iss 1, Pp 1-

2023 Volume 19

Abstract: Abstract Photoacoustic (PA) imaging enables noninvasive volumetric imaging of biological tissues by capturing the endogenous optical absorption contrast. Conventional ultrasound detectors using piezoelectric materials have been widely used for ... ...

Abstract	Abstract Photoacoustic (PA) imaging enables noninvasive volumetric imaging of biological tissues by capturing the endogenous optical absorption contrast. Conventional ultrasound detectors using piezoelectric materials have been widely used for transducing ultrasound signals into the electrical signals for PA imaging reconstruction. However, their inherent limitations in detection bandwidth and sensitivity per unit area have unfortunately constrained the performance of PA imaging. Optical based ultrasound detection methods emerge to offer very promising solutions. In particular, polymer micro-ring resonators (MRRs) in the form of integrated photonic circuits (IPC) enable significant reduction for the sensing area to 80 μm in diameter, while maintaining highly sensitive ultrasound detection with noise equivalent pressure (NEP) of 0.49 Pa and a broad detection frequency range up to 250 MHz. The continued engineering innovation has further transformed MRRs to be transparent to the light and thus, opens up a wide range of applications, including multi-modality optical microscope with isometric resolution, PA endoscope, photoacoustic computed tomography (PACT), and more. This review article summarizes and discusses the evolution of polymer MRR design and the associated nanofabrication process for improving the performance of ultrasound detection. The resulting novel imaging applications will also be reviewed and discussed.
Keywords	Photoacoustic imaging ; Micro-ring resonator ; Ultrasound detector ; Nano-fabrication ; Maskless lithography ; Nanoimprint lithography ; Technology ; T ; Chemical technology ; TP1-1185 ; Biotechnology ; TP248.13-248.65 ; Science ; Q ; Physics ; QC1-999
Subject code	620
Language	English
Publishing date	2023-06-01T00:00:00Z
Publisher	SpringerOpen
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Microbiologically influenced corrosion of circulating cooling systems in power plants – A review

Jialin Li / Lijuan Chen / Bo Wei / Jin Xu / Boxin Wei / Cheng Sun

Arabian Journal of Chemistry, Vol 17, Iss 2, Pp 105529- (2024)

2024

Abstract: The problems caused by microbiologically influenced corrosion (MIC) have become increasingly prominent, which has caused very serious economic losses. The research on the mechanism and protective measures of MIC is becoming more and more important. In ... ...

Abstract	The problems caused by microbiologically influenced corrosion (MIC) have become increasingly prominent, which has caused very serious economic losses. The research on the mechanism and protective measures of MIC is becoming more and more important. In this paper, combined with the unique environment of the circulating water cooling system, the influence of the unique environmental factors of the system on MIC is analyzed. Several kinds of bacteria known to cause microbial corrosion are summarized, including sulfate-reducing bacteria, nitrate-reducing bacteria, iron oxidizing bacteria, etc. The current MIC mechanisms and related research progress are reviewed. Several common MIC monitoring methods are summarized. The commonly used protection methods and the ideas of MIC technologies in the recent stage are listed. Finally, the future research direction of the MIC is prospected.
Keywords	Microbiologically influenced corrosion ; Circulating cooling system ; Corrosion mechanism ; Sulfate reducing bacteria ; Prevention ; Chemistry ; QD1-999
Language	English
Publishing date	2024-02-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Dynamics of a 3-UPS-UPU-S Parallel Mechanism

Jing-Shan Zhao / Song-Tao Wei / Xiao-Cheng Sun

Applied Sciences, Vol 13, Iss 3912, p

2023 Volume 3912

Abstract: In this paper, a parallel mechanism with two rotational degrees of freedom is proposed. It could rotate freely and continuously around the two coordinate axes at the fixed origin of the coordinate frame. The structure of the mechanism is a second-order ... ...

Abstract	In this paper, a parallel mechanism with two rotational degrees of freedom is proposed. It could rotate freely and continuously around the two coordinate axes at the fixed origin of the coordinate frame. The structure of the mechanism is a second-order over constraint parallel structure and the moving platform and base platform are connected by five kinematic chains. The motion characteristics of this structure are analyzed by reciprocal screw equation. Then, the kinematics and dynamics modelling are carried out systematically in a unified way. The kinematics of the mechanism is established by means of screws, the displacements and accelerations of each joint and any point on a link could be calculated by the kinematic screw equation directly. The analysis of acceleration and its mathematical expression in screw form are given, and the acceleration matrix could be applied into the dynamic analysis based on the Newton–Euler equation. All the constraint forces and torques could be obtained by a single set of Newton–Euler equations.
Keywords	kinematics ; screw dynamics ; closed kinematic chain ; numerical algorithm ; Technology ; T ; Engineering (General). Civil engineering (General) ; TA1-2040 ; Biology (General) ; QH301-705.5 ; Physics ; QC1-999 ; Chemistry ; QD1-999
Subject code	629
Language	English
Publishing date	2023-03-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Equity Measurement of Public Sports Space in Central Urban Areas Based on Residential Scale Data

Ying Liu / Huan Wang / Cheng Sun / Huifang Wu

International Journal of Environmental Research and Public Health, Vol 19, Iss 3104, p

2022 Volume 3104

Abstract: Urban public sports facilities have captured much public attention because of their close ties to public health. However, few studies have comprehensively assessed the equity of accessibility to various types of public sports space with a fine scale. ... ...

Abstract	Urban public sports facilities have captured much public attention because of their close ties to public health. However, few studies have comprehensively assessed the equity of accessibility to various types of public sports space with a fine scale. This study proposed a spatial equity measurement method based on multi-source urban data and GIS network analysis. Residential buildings were taken as the minimum research unit to investigate the equity differences of residents’ enjoyment of urban public sports space accessible by walking and public transportation. Taking Harbin, China, as an example, this study calculated and visualized the proximity of more than 12,000 residential buildings to a variety of public sports space in the central urban area. The results showed that: (1) urban centers enjoy more public sports space resources than border areas, that is, the developed area has more advantages than the emerging area; (2) according to the classification of sports space, their spatial distribution pattern and measurement results are obviously different; (3) the areas with a low walking equity degree also had a low bus equity degree. This study integrated multi-source data into the traditional spatial computing models and provided an important reference for the equitable planning of urban public sports space.
Keywords	public sports facilities ; spatial equity ; network analysis ; multi-source data ; traffic mode ; Medicine ; R
Subject code	720
Language	English
Publishing date	2022-03-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Trend Changes of the Vegetation Activity in Northeastern East Asia and the Connections with Extreme Climate Indices

Zijing Guo / Wei Lou / Cheng Sun / Bin He

Remote Sensing, Vol 14, Iss 3151, p

2022 Volume 3151

Abstract: In the context of global warming, vegetation activity in northeastern East Asia (40–45°N, 105–130°E) (NEA) shows a significant growth trend on a multidecadal scale, but how vegetation changes on a decadal scale is unclear. In this study, we find a ... ...

Abstract	In the context of global warming, vegetation activity in northeastern East Asia (40–45°N, 105–130°E) (NEA) shows a significant growth trend on a multidecadal scale, but how vegetation changes on a decadal scale is unclear. In this study, we find a significant trend of vegetation greening in northeastern East Asia during 1982–1998 and a slowdown in the greening trend during 1998–2014. Trend analysis of the extreme climate indices reveals that the trends of precipitation-related extreme climate indices are similar to those of vegetation change, and further correlation analysis reveals that precipitation-related extreme climate indices have a strong positive correlation with the NDVI. The results indicate that the vegetation in northeastern East Asia is more sensitive to precipitation changes, especially extreme precipitation, compared with the temperature and related extreme indices. Furthermore, the analysis of large-scale atmospheric circulation changes suggests a role of Northwest Pacific subtropical high (NPSH) in the trend changes of precipitation-related extreme indices. The strengthening of NPSH before 1998 enhances the moisture transport to the NEA, providing abundant water vapor favorable for extreme precipitation events, while after 1998, the NPSH trend is much weakened, corresponding to a decrease in the moisture transport trend.
Keywords	northeastern East Asia ; NDVI ; extreme events ; subtropical high ; Science ; Q
Subject code	910
Language	English
Publishing date	2022-06-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Resilience-Based Repair Strategy for Gas Network System and Water Network System in Urban City

Xirong Bi / Jingxian Wu / Cheng Sun / Kun Ji

Sustainability, Vol 14, Iss 3344, p

2022 Volume 3344

Abstract: In resilience-based frameworks, optimizing the repair strategy and approaches is important for the recovery of the function of gas network systems (GNS) and water network systems (WNS). According to the resilience quantification results of GNS and WNS ... ...

Abstract	In resilience-based frameworks, optimizing the repair strategy and approaches is important for the recovery of the function of gas network systems (GNS) and water network systems (WNS). According to the resilience quantification results of GNS and WNS for a real example urban city in China, the potential impact of utilizing different repair sequences and repair/replacement approaches was investigated. First, a Monte Carlo simulation-based method was proposed to search for the optimal repair sequence according to the skew of the recovery trajectory (SRT). Under high seismic intensity conditions, the significant difference between the repair sequence corresponding to maximum SRT and minimum SRT indicates that choosing the optimal repair sequence is important in the enhancement of repair efficiency, especially when the pipelines have experienced serious damage. We also discussed the parallel repair strategy, which is more consistent with the practice, and can greatly improve the recovery efficiency compared with the single pipeline repair strategy under large damage conditions; however, under minor damage levels, the parallel repair strategy may result in a certain degree of redundancy. Next, three different repair approaches were thoroughly compared, including the point-by-point repair approach, whole pipeline replacement, and hybrid repair approach. At the condition of high seismic intensity (e.g., macroseismic intensity IX), the resilience curves for the hybrid repair approach and the pipeline replacement approach are overall similar and take less time and economic cost than the point-by-point repair approach. However, when the seismic intensity is low, the point-by-point repair approach is most efficient and has the shortest recovery time. Therefore, the choice of repair approach should be determined by stakeholders based on the specific pipeline’s damage situation. Finally, we calculated the joint resilience curves by allocating different weight factors to GNS and WNS, to represent the proportion of water and ...
Keywords	water network system ; gas network system ; seismic resilience ; parallel repair ; quantitative evaluation of resilience ; repair efficiency ; Environmental effects of industries and plants ; TD194-195 ; Renewable energy sources ; TJ807-830 ; Environmental sciences ; GE1-350
Subject code	500
Language	English
Publishing date	2022-03-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Periodic decadal swings in dry/wet conditions over Central Asia

Yusen Liu / Cheng Sun / Zengchao Hao / Bian He

Environmental Research Letters, Vol 17, Iss 5, p

2022 Volume 054050

Abstract: Periodic variability in the hydro-climatic system has important implications not only for climate prediction but also for planning and managing water resources. Here we identify periodic decadal variability of dry/wet conditions in Central Asia (CA) ... ...

Abstract	Periodic variability in the hydro-climatic system has important implications not only for climate prediction but also for planning and managing water resources. Here we identify periodic decadal variability of dry/wet conditions in Central Asia (CA) since the mid-20th century, which are tied to the Pacific quasi-decadal oscillation (PQDO) with a period of 8–16 years ( r = 0.87). The periodically varying forcing in the Pacific modulates zonal winds and moisture transport and profoundly affects the precipitation on the decadal time scale. The PQDO-related equatorial central Pacific warming significantly heats the overlying troposphere, increasing the meridional temperature/geopotential gradients in the subtropics. As a result, the strengthened westerly jet in CA transports more water vapor from the North Atlantic and increases local precipitation. The plateau to the east further amplifies the increased precipitation in eastern CA through orographic influence on the convection and large-scale circulation. The atmospheric model forced by the PQDO signal reproduces an overall consistent mechanism with the observation, indicating a robust synchronization of the Central Asian hydro-climatic system to the PQDO. The newly discovered oscillatory feature in this study may advance the predictability of Central Asian precipitation on the decadal time scale, which promotes the mitigation and prevention of natural disasters like droughts and wildfires.
Keywords	decadal oscillation ; Pacific quasi-decadal oscillation ; Central Asian dry/wet conditions ; periodic climate variability ; Environmental technology. Sanitary engineering ; TD1-1066 ; Environmental sciences ; GE1-350 ; Science ; Q ; Physics ; QC1-999
Subject code	551
Language	English
Publishing date	2022-01-01T00:00:00Z
Publisher	IOP Publishing
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Variations and Factors Characterizing Ecological Niches of Understory Herbaceous Species in Plantation Forests

Cheng Sun / Long Li / Xiaoyu Dong / Fucang Qin / Zhenqi Yang

Sustainability, Vol 14, Iss 10719, p

2022 Volume 10719

Abstract: Plant ecological niche characteristics are powerful representations of plant survival status. Understory herbaceous species in plantation forests are sensitive to local ecological environment changes; patterns of ecological niche changes of herbaceous ... ...

Abstract	Plant ecological niche characteristics are powerful representations of plant survival status. Understory herbaceous species in plantation forests are sensitive to local ecological environment changes; patterns of ecological niche changes of herbaceous plants under plantation forests are of great significance for maintaining the stability and sustainable development of plantation forest ecosystems. This study aims to explore the ecological niche characteristics of understory herbaceous species in plantation forests and their influencing factors. Six different site types of Pinus tabulaeformis plantations were selected from a stable plantation community in the feldspathic sandstone area of the Loess Plateau (China). The relative importance value and niche breadth were used as comprehensive quantitative indices to characterize the status, role, and degree of dominance of understory herbaceous species in plantation forests. We found few dominant species of understory herbaceous species in plantation forests, mostly companion species. The niche characteristics of understory herbaceous species in plantation forests varied significantly. For understory herbaceous species, the niche width was positively correlated with slopes and the niche overlap of the sunny slopes was positively relevant with slopes, while that of the shady slopes was negatively correlated. A canonical correspondence analysis indicated that several major factors influencing the niche breadth and niche overlap of understory herbaceous species in plantation forests were different. The canopy density and slope of plantation played a major role in the niche breadth and niche overlap of understory herbaceous species in plantation forests. In summary, the species distribution of understory herbaceous species in plantation forests was determined by site type. The canopy density and geographical slope were the dominant environmental factors for different ecological niche characteristics of understory herbaceous species. The ecological niche variation of ...
Keywords	plantation forests ; niche breadth ; niche overlap ; environmental interpretation ; Environmental effects of industries and plants ; TD194-195 ; Renewable energy sources ; TJ807-830 ; Environmental sciences ; GE1-350
Language	English
Publishing date	2022-08-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Research on a Service Load Prediction Method Based on VMD-GLRT

Jin Zhang / Yiqi Huang / Yu Pi / Cheng Sun / Wangyang Cai / Yuanyuan Huang

Applied Sciences, Vol 13, Iss 3315, p

2023 Volume 3315

Abstract: In this paper, a deep learning-based prediction model VMD-GLRT is proposed to address the accuracy problem of service load prediction. The VMD-GLRT model combines Variational Mode Decomposition (VMD) and GRU-LSTM. At the same time, the model incorporates ...

Abstract	In this paper, a deep learning-based prediction model VMD-GLRT is proposed to address the accuracy problem of service load prediction. The VMD-GLRT model combines Variational Mode Decomposition (VMD) and GRU-LSTM. At the same time, the model incorporates residual networks and self-attentive mechanisms to improve accuracy of the model. The VMD part decomposes the original time series into several intrinsic mode functions (IMFs) and a residual part. The other part uses a GRU-LSTM structure with ResNets and Self-Attention to learn the features of the IMF and the residual part. The model-building process focuses on three main aspects: Firstly, a mathematical model is constructed based on the data characteristics of the service workload. At the same time, VMD is used to decompose the input time series into multiple components to improve the efficiency of the model in extracting features from the data. Secondly, a long and short-term memory (LSTM) network unit is incorporated into the residual network, allowing the network to correct the predictions more accurately and improve the performance of the model. Finally, a self-focus mechanism is incorporated into the model, allowing the model to better capture features over long distances. This improves the dependence of the output vector on these features. To validate the performance of the model, experiences were conducted using open-source datasets. The experimental results were compared with other deep learning and statistical models, and it was found that the model proposed in this paper achieved improvements in mean absolute percentage error (MAPE).
Keywords	deep learning ; cloud computing ; microservices ; time series analysis ; Technology ; T ; Engineering (General). Civil engineering (General) ; TA1-2040 ; Biology (General) ; QH301-705.5 ; Physics ; QC1-999 ; Chemistry ; QD1-999
Subject code	330
Language	English
Publishing date	2023-03-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Genus-Wide Characterization of Nuclear Mitochondrial DNAs in Bumblebee (Hymenoptera

Lele Ding / Huiling Sang / Cheng Sun

Insects, Vol 12, Iss 963, p

Apidae) Genomes

2021 Volume 963

Abstract: In eukaryotes, DNA of mitochondria is transferred into the nucleus and forms nuclear mitochondrial DNAs (NUMTs). Taking advantage of the abundant genomic resources for bumblebees, in this study, we de novo generated mitochondrial genomes (mitogenomes) ... ...

Abstract	In eukaryotes, DNA of mitochondria is transferred into the nucleus and forms nuclear mitochondrial DNAs (NUMTs). Taking advantage of the abundant genomic resources for bumblebees, in this study, we de novo generated mitochondrial genomes (mitogenomes) for 11 bumblebee species. Then, we identified and characterized NUMTs in genus-wide bumblebee species. The number of identified NUMTs varies across those species, with numbers ranging from 32 to 72, and nuclear genome size is not positively related to NUMT number. The insertion sites of NUMTs in the nuclear genome are not random, with AT-rich regions harboring more NUMTs. In addition, our results suggest that NUMTs derived from the mitochondrial COX1 gene are most abundant in the bumblebee nuclear genome. Although the majority of NUMTs are found within intergenic regions, some NUMTs do reside within genic regions. Transcripts that contain both the NUMT sequence and its flanking non-NUMT sequences could be found in the bumblebee transcriptome, suggesting a potential domestication of NUMTs in the bumblebee. Taken together, our results shed light on the molecular features of NUMTs in the bumblebee and uncover their contribution to genome innovation.
Keywords	bumblebee ; mitogenome ; NUMT ; genome innovation ; Science ; Q
Subject code	580
Language	English
Publishing date	2021-10-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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