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Article ; Online: Modeling and simulation analysis of Starlink constellation communication

LI Yuanlong, LI Zhiqiang

Zhihui kongzhi yu fangzhen, Vol 45, Iss 4, Pp 118-

2023 Volume 126

Abstract: Starlink is the only giant constellation in low Earth orbit currently being rapidly deployed. This paper analyzes the advantages and characteristics of low orbit satellite communication and summarizes Starlink construction and system architecture. The ... ...

Abstract	Starlink is the only giant constellation in low Earth orbit currently being rapidly deployed. This paper analyzes the advantages and characteristics of low orbit satellite communication and summarizes Starlink construction and system architecture. The Satellite Toolkit (STK) is used to model and simulate 1 584 satellites of the first stage "Group 1". Then, according to the networking mode of Starlink satellite equipped with laser communication payload, Dijkstra algorithm is used to solve the shortest inter-satellite communication link distance between any two Starlink satellites. Thus, the theoretical shortest communication delay is calculated. The average communication delay from Hawaii Camp Smith to the Yokota Air Base is 42.700 749 2 ms. Based on the simulation results, the military application of Starlink in communication is predicted.
Keywords	leo satellite\|satellite internet\|starlink\|satellite tool kit\|communication delay\|military application ; Military Science ; U
Subject code	380
Language	Chinese
Publishing date	2023-08-01T00:00:00Z
Publisher	Editorial Office of Command Control and Simulation
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: The role of eddy-wind interaction in the eddy kinetic energy budget of the Agulhas retroflection region

Yanan Zhu / Yuanlong Li / Yang Yang / Fan Wang

Environmental Research Letters, Vol 18, Iss 10, p

2023 Volume 104032

Abstract: The Agulhas retroflection (AR) region possesses the highest eddy kinetic energy (EKE) level in the Indian Ocean. However, mechanisms regulating EKE of the AR remain uncertain. Here, by analyzing an eddy-resolving coupled model simulation with improved ... ...

Abstract	The Agulhas retroflection (AR) region possesses the highest eddy kinetic energy (EKE) level in the Indian Ocean. However, mechanisms regulating EKE of the AR remain uncertain. Here, by analyzing an eddy-resolving coupled model simulation with improved EKE representation, we show that the upper-ocean EKE of the AR is mainly generated through barotropic instability in its upstream and leakage zones and is by nonlocal transport in its downstream zone. The interaction between mesoscale eddies and local winds plays a key role in EKE dissipation. The lack of eddy-wind interaction results in flawed EKE budget in the leakage zone in ocean-alone models, leading to severe biases in EKE distribution with overestimation and over-strong penetration into the South Atlantic. Our results highlight the essence of mesoscale air-sea interaction in the dynamics of the AR, with implications for understanding the inter-basin transport of the Agulhas leakage.
Keywords	mesoscale eddies ; eddy kinetic energy ; mesoscale air-sea interaction ; Agulhas current ; South Indian Ocean ; western boundary currents ; Environmental technology. Sanitary engineering ; TD1-1066 ; Environmental sciences ; GE1-350 ; Science ; Q ; Physics ; QC1-999
Subject code	551
Language	English
Publishing date	2023-01-01T00:00:00Z
Publisher	IOP Publishing
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Biogeographical patterns and mechanisms of microbial community assembly that underlie successional biocrusts across northern China

Yuanlong Li / Chunxiang Hu

npj Biofilms and Microbiomes, Vol 7, Iss 1, Pp 1-

2021 Volume 11

Abstract: Abstract Biocrusts play critical eco-functions in many drylands, however it is challenging to explore their community assembly, particularly within patched successional types and across climate zones. Here, different successional biocrusts (alga, lichen, ...

Abstract	Abstract Biocrusts play critical eco-functions in many drylands, however it is challenging to explore their community assembly, particularly within patched successional types and across climate zones. Here, different successional biocrusts (alga, lichen, and moss-dominated biocrusts) were collected across the northern China, and assembly of biocrust microbial communities was investigated by high-throughput sequencing combined with measurements of soil properties and microclimate environments. Bacterial and eukaryotic communities showed that the maximum and minimum community variation occurred across longitude and latitude, respectively. In the regions where all three stages of biocrusts were involved, the highest community difference existed between successional stages, and decreased with distance. The community assembly was generally driven by dispersal limitation, although neutral processes have controlled the eukaryotic community assembly in hyperarid areas. Along the succession, bacterial community had no obvious patterns, but eukaryotic community showed increasing homogeneity, with increased species sorting and decreased dispersal limitation for community assembly. Compared to early successional biocrusts, there were higher microbial mutual exclusions and more complex networks at later stages, with distinct topological features. Correlation analysis further indicated that the balance between deterministic and stochastic processes might be mediated by aridity, salinity, and total phosphorus, although the mediations were opposite for bacteria and eukaryotes.
Keywords	Microbial ecology ; QR100-130
Subject code	941
Language	English
Publishing date	2021-02-01T00:00:00Z
Publisher	Nature Portfolio
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Weak Mesoscale Variability in the Optimum Interpolation Sea Surface Temperature (OISST)-AVHRR-Only Version 2 Data before 2007

Yanan Zhu / Yuanlong Li / Fan Wang / Mingkun Lv

Remote Sensing, Vol 14, Iss 409, p

2022 Volume 409

Abstract: Mesoscale sea surface temperature (SST) variability triggers mesoscale air–sea interactions and is linked to ocean subsurface mesoscale dynamics. The National Oceanic and Atmospheric Administration (NOAA) daily Optimum Interpolation SST (OISST) products, ...

Abstract	Mesoscale sea surface temperature (SST) variability triggers mesoscale air–sea interactions and is linked to ocean subsurface mesoscale dynamics. The National Oceanic and Atmospheric Administration (NOAA) daily Optimum Interpolation SST (OISST) products, based on various satellite and in situ SST data, are widely utilized in the investigation of multi-scale SST variabilities and reconstruction of subsurface and deep-ocean fields. The quality of OISST datasets is subjected to temporal inhomogeneity due to alterations in the merged data. Yet, whether this issue can significantly affect mesoscale SST variability is unknown. The analysis of this study detects an abrupt enhancement of mesoscale SST variability after 2007 in the OISST-AVHRR-only version 2 and version 2.1 datasets (hereafter OI.v2-AVHRR-only and OI.v2.1-AVHRR-only). The contrast is most stark in the subtropical western boundary current (WBC) regions, where the average mesoscale SST variance during 2007–2018 is twofold larger than that during 1993–2006. Further comparisons with other satellite SST datasets (TMI, AMSR-E, and WindSAT) suggest that the OISST-AVHRR-only datasets have severely underestimated mesoscale SST variability before 2007. An evaluation of related documents of the OISST data indicates that this bias is mainly caused by the change of satellite AVHRR instrument in 2007. There are no corresponding changes detected in the associated fields, such as the number and activity of mesoscale eddies or the background SST gradient in these regions, confirming that the underestimation of mesoscale SST variability before 2007 is an artifact. Another OISST product, OI.v2-AVHRR-AMSR, shows a similar abrupt enhancement of mesoscale SST variability in June 2002, when the AMSR-E instrument was incorporated. This issue leaves potential influences on scientific research that utilize the OISST datasets. The composite SST anomalies of mesoscale eddies based on the OI.v2-AVHRR-only data are underestimated by up to 37% before 2007 in the subtropical WBC regions. The underestimation of mesoscale variability also affects the total (full-scale) SST variability, particularly in winter. Other SST data products based on the OISST datasets were also influenced; we identify suspicious changes in J-OFURO3 and CFSR datasets; the reconstructed three-dimensional ocean products using OISST data as input may also be inevitably affected. This study reminds caution in the usage of the OISST and relevant data products in the investigation of mesoscale processes.
Keywords	mesoscale eddies ; mesoscale air–sea interaction ; mesoscale SST anomalies ; OISST data ; western boundary current ; Science ; Q
Subject code	551
Language	English
Publishing date	2022-01-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Water sources of the Lombok, Ombai and Timor outflows of the Indonesian throughflow

Yaru Guo / Yuanlong Li / Dezhou Yang / Yuxuan Li / Fan Wang / Guandong Gao

Frontiers in Marine Science, Vol

2023 Volume 10

Abstract: The Lombok Strait (LS), Ombai Strait (OS), and Timor Passage (TP) are three major outlets of the Indonesian Throughflow to the Indian Ocean. Here, sources and pathways of the LS, OS, and TP outflows are explored by a Lagrangian particle tracking analysis ...

Abstract	The Lombok Strait (LS), Ombai Strait (OS), and Timor Passage (TP) are three major outlets of the Indonesian Throughflow to the Indian Ocean. Here, sources and pathways of the LS, OS, and TP outflows are explored by a Lagrangian particle tracking analysis based on a ~3 km regional ocean model simulation. The Makassar Strait transport contributes to ~80%, ~75%, and ~45% of the LS, OS, and TP outflows, respectively. However, ~41% and ~19% of the TP and OS outflows stem from the Lifamatola Passage, which largely feeds the upper and intermediate layers of the outflows. The role of Karimata Strait is quite limited and restricted to the upper layer. It takes 1-2 years and 2-6 years for the Makassar Strait water to reach the OS and TP, respectively, whereas the Lifamatola Passage water passes through the OS (2-6 years) and TP (3-9 years) on a prolonged transit time. In the Banda Sea, the western boundary current is the main pathway toward the OS, while the waters to the TP tend to take a basin interior route.
Keywords	the Indonesian throughflow ; Indonesian seas ; lagrangian particle tracking ; Makassar strait ; Lifamatola passage ; Science ; Q ; General. Including nature conservation ; geographical distribution ; QH1-199.5
Subject code	551
Language	English
Publishing date	2023-12-01T00:00:00Z
Publisher	Frontiers Media S.A.
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Wind-Driven Mechanisms for the Variations of the Pacific Equatorial Undercurrent Based on Adjoint Sensitivity Analysis

Jin Wang / Chuanyu Liu / Xiaowei Wang / Armin Köhl / Yilong Lyu / Yuanlong Li / Fan Wang

Frontiers in Marine Science, Vol

2022 Volume 9

Abstract: The maintenance and variation of the Pacific Equatorial Undercurrent (EUC) are thought to be controlled by the zonal pressure gradient force (ZPGF). However, a recent study found that a large-scale circulation associated with Rossby waves can also lead ... ...

Abstract	The maintenance and variation of the Pacific Equatorial Undercurrent (EUC) are thought to be controlled by the zonal pressure gradient force (ZPGF). However, a recent study found that a large-scale circulation associated with Rossby waves can also lead to EUC variation, implying that the structures and timing of the influential winds and the underlying wind-driven mechanisms need to be revisited. Here, we use the adjoint-sensitivity method to obtain the crucial winds that can most efficiently influence EUC variations. The obtained adjoint sensitivities (denoting the sensitive winds) are confined to 15°S–15°N and exhibit a funnel-shaped pattern with high symmetry about the equator. The remote winds, which occur 4 to 11 months prior, can lead to EUC variations at the basin scale; in contrast, the near-term winds (occurring not earlier than 4 months) lead only to local EUC variations. Accordingly, we find that wind-initiated equatorial Kelvin waves, equatorial Rossby waves, and the reflected waves at both the western and eastern boundaries superimpose onto each other to result in EUC variations. Specifically, when the travel time is longer than 4 months, the waves can form a negative-positive-negative sea surface height anomaly (SSHA) pattern between 15°S and 15°N in the central-eastern tropical Pacific, indicating the joint effect of both types of waves; they also form a positive SSHA in the western equatorial Pacific, indicating the dominance of the Kelvin wave therein. These mechanisms are complementary to the canonical ZPGF mechanism, which provide a clear theoretical basis for EUC variation studies.
Keywords	Equatorial Undercurrent ; adjoint sensitivity analysis ; equatorial Rossby wave ; Kelvin wave ; wind-driven ; Science ; Q ; General. Including nature conservation ; geographical distribution ; QH1-199.5
Subject code	551
Language	English
Publishing date	2022-06-01T00:00:00Z
Publisher	Frontiers Media S.A.
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Effects of mesoscale eddies on intraseasonal variability of intermediate water east of Taiwan

Qiang Ren / Fei Yu / Feng Nan / Yuanlong Li / Jianfeng Wang / Yansong Liu / Zifei Chen

Scientific Reports, Vol 12, Iss 1, Pp 1-

2022 Volume 13

Abstract: Abstract The intraseasonal variability of the intermediate water (IW) and its characteristics east of Taiwan are studied utilizing 17 months of long-term, continuous and synchronous measurements of temperature, salinity and current from mooring sites ... ...

Abstract	Abstract The intraseasonal variability of the intermediate water (IW) and its characteristics east of Taiwan are studied utilizing 17 months of long-term, continuous and synchronous measurements of temperature, salinity and current from mooring sites deployed at 122° E/23° N from January 2016 to May 2017. Direct measurements revealed water masses east of Taiwan alternately show complete South China Sea Intermediate Water or North Pacific Intermediate Water (NPIW) characteristics, mostly in a mixed state, with NPIW dominating 70% of the time. For the first time, it is demonstrated that the variation of IW with periods of ~ 80 days is mainly related to mesoscale eddies. Anticyclonic (cyclonic) eddies corresponding to an increase (decrease) in temperature and salinity in the intermediate layer. Further mechanism analysis indicates the vertical motion of the water mass inside the eddies is one of the reasons for the thermohaline change in the intermedaiter layer. In addition, the anticyclonic eddies may increase the salinity concentration gradient across the Luzon Strait, and the enhanced advection is favorable to the outflow of water masses in the South China Sea. When the cyclonic eddies acts on the eastern part of Taiwan, the influence of the northward advection is weakened and the southward flow on its left side is more favorable to the transport of NPIW.
Keywords	Medicine ; R ; Science ; Q
Subject code	551
Language	English
Publishing date	2022-06-01T00:00:00Z
Publisher	Nature Portfolio
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Development of A Safety Climate Scale for Geological Prospecting Projects in China

Xiang Wu / Jingqi Gao / Yuanlong Li / Chunlin Wu

International Journal of Environmental Research and Public Health, Vol 16, Iss 6, p

2019 Volume 1082

Abstract: The geological prospecting industry has developed rapidly in China over the past few years. It has made outstanding contributions to the discovery of new mineral resources, new energy sources, and the excavation and utilization of resources. However, ... ...

Abstract	The geological prospecting industry has developed rapidly in China over the past few years. It has made outstanding contributions to the discovery of new mineral resources, new energy sources, and the excavation and utilization of resources. However, geological prospecting projects do not have effective safety management measures at present. Moreover, the geological prospecting project has its own traits and features that differ from other industries, leading to the fact that safety management measures in other industries cannot be used in geological prospecting projects. Therefore, development of an effective safety management measuring tool is urgent and necessary. In recent years, safety climate has drawn great attention from scholars, and research results have been successfully applied in construction, coal mining and other industries. Based on the extensive literature review on safety climate as well as its organizational structure and employees’ individual behavior characteristics, this paper first extracted the factor structure of the safety climate and then developed a safety climate scale for geological prospecting projects. This paper used the methods of exploratory factor analysis and reliability analysis to ensure the developed safety climate scale was valid and reliable. The safety climate scale developed has four dimensions, i.e., project leader’s safety commitment, safety institutions, risk response, and employee’s safety attitude, containing a total of 17 measurable items. This study contributes to the current literature by exploring the factor structure of the safety climate for geological prospecting projects, and further provides a scientific basis for improvements in the geological prospecting industry. Meanwhile, the findings not only provide technical support for investigating and analyzing the safety management levels of the geological prospecting industry, but also contribute to the benchmarking standards among different enterprises and projects.
Keywords	geological prospecting project ; safety climate ; factor analysis ; scale development ; Medicine ; R
Language	English
Publishing date	2019-03-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: The Mechanism of Zinc Sulfate in Improving Fertility in Obese Rats Analyzed by Sperm Proteomic Analysis

Jing Ma / Ruiyu Han / Yuanlong Li / Tong Cui / Shusong Wang

BioMed Research International, Vol

2020 Volume 2020

Abstract: This study investigates the mechanism underlying the improving effect of zinc on fertility in obese rats using proteomics. The effects of three different doses of ZnSO4 on spermatogenesis and hormone levels were studied. Testicular spermatogenesis was ... ...

Abstract	This study investigates the mechanism underlying the improving effect of zinc on fertility in obese rats using proteomics. The effects of three different doses of ZnSO4 on spermatogenesis and hormone levels were studied. Testicular spermatogenesis was observed by HE staining. Serum estrogen and testosterone levels were measured by chemiluminescent microparticle immunoassay. Sperm proteomic analysis was performed by liquid chromatography-mass spectrometry. The DAVID database was used to perform the GO enrichment analysis and KEGG pathway analysis of the differentially expressed genes, and the STRING online database was used to construct a PPI network. The sperm count, sperm motility, and testosterone hormones of the ZnSO4-treated rats group were increased. ZnSO4 improved testicular structure and spermatogenesis abnormalities caused by obesity. Proteomic analysis showed that there were 401 differentially expressed proteins in a total of 6 sperm samples from the ZnSO4-treated group and the obesity groups. Differential proteins were input into the DAVID website. The 341 identified proteins were then classified according to their biological functions. The KEGG analysis showed that the enriched signal pathways included glycolysis/gluconeogenesis, carbon metabolism, citrate cycle, fatty acid metabolism, and pyruvate metabolism. Some proteins were shown to be associated with valine, leucine, and isoleucine degradation pathways. STRING analysis obtained 36 node proteins. Cytoscape analysis showed that these proteins mainly participated in nine networks including metabolic process, oxidation-reduction, aerobic respiration, RNA splicing, and glutathione conjugation. ZnSO4 may improve the fertility of obese male rats by regulating protein expression related to metabolism, inflammation, and sperm maturation.
Keywords	Medicine ; R
Subject code	572
Language	English
Publishing date	2020-01-01T00:00:00Z
Publisher	Hindawi Limited
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Development and Validation of a Safety Attitude Scale for Coal Miners in China

Xiang Wu / Wenwen Yin / Chunlin Wu / Yuanlong Li

Sustainability, Vol 9, Iss 12, p

2017 Volume 2165

Abstract: Safety attitude is of vital importance to accident prevention, and the high accident rate in the coal mining industry makes it urgent to undertake research on coal miners’ safety attitude. However, the current literature still lacks a valid and reliable ... ...

Abstract	Safety attitude is of vital importance to accident prevention, and the high accident rate in the coal mining industry makes it urgent to undertake research on coal miners’ safety attitude. However, the current literature still lacks a valid and reliable safety attitude measurement scale for coal miners, which stands as a barrier against their safety attitude improvement. In this study, a scale is developed that can be used to measure coal miners’ safety attitude. The preliminary scale was based on an extended literature review. Empirical data were then collected from 725 coal miners using the preliminary scale. Both exploratory and confirmatory factor analyses were undertaken to validate and improve the scale. The final scale, which consists of 17 items, contains four dimensions: management safety commitment, team safety climate, fatalism and work pressure. Results show that this safety attitude scale can effectively measure the safety attitude of coal miners, showing high psychological measurement validity. This paper contributes to the occupational safety research by developing the factor structure and indicator system of coal miners’ safety attitude, thus providing more profound interpretation of this crucial construct in the safety research domain. The measurement scale serves as an important tool for safety attitude benchmarking among different coal mining enterprises and, thus, can boost the overall safety improvement of the whole industry. These findings can facilitate improvement of both theories and practices related to occupational safety attitude.
Keywords	safety attitude ; measurement scale ; coal miners ; exploratory factor analysis ; confirmatory factor analysis ; Environmental effects of industries and plants ; TD194-195 ; Renewable energy sources ; TJ807-830 ; Environmental sciences ; GE1-350
Subject code	306
Language	English
Publishing date	2017-11-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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