bluuebunny/crossref_metadata_2025 huggingface dataset:
Resonances of electromagnetically induced transparency and absorption in a light field of elliptically polarised waves
Authors: Kovalenko D.V. , Basalaev M.Yu. , Yudin V.I. , Taichenachev A.V.
Published: June 2020

Electromagnetically induced transparency (EIT) and electromagnetically induced absorption (EIA) resonances excited by a strong two-frequency field are considered for various values of the total angular momenta of the ground (F
g) and excited (F
e) states at a degenerated optical closed transition F
g → F
e. The light field is formed by two co-propagating waves with arbitrary elliptical polarisations. The process of spontaneous transfer of anisotropy from the excited state to the ground state is shown to determine the formation of the EIA resonance at the transition F
g = F → F
e = F + 1. The results obtained generalise the classification of transitions into ‘bright’ (F
g = F → F
e = F + 1) and ‘dark’ (F
g = F → F
e = F and F
g = F → F
e = F – 1) transitions with respect to the direction of a subnatural resonance.
The relationships between udder-quarter somatic-cell counts and milk and milking parameters in cows managed with an automatic milking system
Authors: Sitkowska Beata , Piwczyński Dariusz , Kolenda Magdalena
Published: June 2020

Context
Some milking parameters such as milk yield, milk flow, milking duration, milk conductivity and somatic-cell count can all be listed as economically important traits in dairy practice.

Aims
The aim of the study was to investigate the relationships among lactation stage, lactation number, milking season and milk-performance traits at an udder-quarter level, including somatic-cell count (SCC), milk yield (MY), milking duration (MD), time in box (TB), milk flow (MF) and milk conductivity (MC). An additional aim was to analyse milking-parameter levels in milkings with a SCC lower and higher than 400000 cells/mL.

Methods
The study included an analysis of 1621582 successful milkings obtained from six herds of dairy cattle equipped with milking robots (AMS).

Key results
The study confirmed that MD and MY differed greatly between front and rear quarters. Rear quarters took longer to be milked but produced more milk. During the first 100 days of lactation, the primiparous cows spent more time in the robot than did multiparous cows; however, in the second and third lactations, older cows were spending more time in the AMS. For primiparous cows, MF increased with time, being the highest at the end of lactation (>200 days in milk). A different trend has been found in the group of multiparous cows, where a steady decrease in MF was observed with subsequent lactation stages. A lower MC was recorded for cows in their first lactation than for multiparous cows. Data obtained from primiparous cows showed the highest MC to occur between 100 and 200 days of lactation. In the group of multiparous cows, MC increased with the lactation stage. It was also shown that the mean values obtained for MY, MD and TB were higher for cows with a lower SCC (<400000). Correlations between lnSCC (the natural logarithm of SCC) and MY and between lnSCC and MD were negative and low, while those between lnSCC and MC and lnSCC and MF were positive. Moderate correlations were found between lnSCC and total MC.

Conclusions
The study confirmed the differences in the performance of different udder quarters in relation to MY, MD, TB, MF, MS and SCC.

Implications
AMS provides farmers with vast data on milk and milking parameters. By monitoring changes in these parameters, farmer may be able to predict the level of production of their herd and the health of cows.
Plastic film mulching improves seed germination, seedling development and potential for perenniality of Vicia unijuga under subalpine climate conditions
Authors: Tang Wei , Baskin Carol C. , Baskin Jerry M. , Nan Zhibiao
Published: June 2020

Our aim was to identify temperature and moisture modifications needed for improvement of seed germination, growth and establishment of the protein-rich forage legume Vicia unijuga A.Br. so that it could become large enough and store sufficient root reserves to survive in subalpine conditions. Germination tolerance of scarified V. unijuga seeds to various temperatures and water potentials was tested in the laboratory, and a 3-year field experiment was conducted in the subalpine region of China to evaluate the effects of modified soil temperature and moisture conditions generated by mulching with plastic film and barley straw on seedling emergence, growth, root nutrient reserves and subsequent overwinter performance. The highest germination percentage and rate occurred at the optimum temperature of 15–20°C, which improved these germination traits at low water potentials between –0.6 and –1.0 MPa. Higher soil temperature and water content were recorded in the plastic mulch treatment than in the control and straw mulch treatments. This enhanced establishment and accumulation of biomass and root reserve pools in the plastic mulch treatment, with nearly 100% of the plants surviving overwinter. The relative contribution of soil temperature was greater than of soil-water content to the variation in biomass and root nutrient reserves. Root starch content explained the most variation in overwinter survival. In conclusion, scarified V. unijuga seeds can germinate over a wide range of conditions, including those in the subalpine zone in spring. The plastic mulch treatment provided adequate soil temperature and water resources to improve growth and root starch reserves in first-year plants of V. unijuga, thereby improving overwinter survival in the subalpine environment.
RNA-Seq-based identification of potential resistance mechanism against the soybean cyst nematode (Heterodera glycines) HG Type 0 in soybean (Glycine max) cv. Dongnong L-204
Authors: Jiang Haipeng , Bu Fanshan , Tian Lizheng , Sun Qiuxia , Bao Dongfang , Zhao Xue , Han Yingpeng
Published: June 2020

Soybean cyst nematode (SCN, Heterodera glycines Ichinohe) is the most important disease affecting yield of soybean (Glycine max (L.) Merr.). In China, among the main physiological races of SCN causing serious economic loss of soybean, HG Type 0 is the most widely distributed. Breeding SCN-resistant varieties is one of the safest and most effective ways to manage SCN. Soybean cv. Dongnong L-204 has a green seed coat and is a resource for resistance to SCN; however, the transcriptional variation and main molecular mechanism of resistance of Dongnong L-204 are not clear. We obtained 66.42 Gb of raw reads by using Illumina HiSeq high-throughput sequencing of Dongnong L-204. Transcriptional changes at Days 3, 7 and 10 after HG Type 0 stress are described. In total, 11279 differentially expressed genes were responsive to HG Type 0 stress, including 6407 SCN-induced and 4872 SCN-suppressed genes. Gene Ontology analysis emphasised the important roles of the terms metabolic process, single-organism process, catalytic activity and binding under HG Type 0 stress. Among them, the terms related to extracellular matrix, extracellular region part, membrane-enclosed lumen, protein-binding transcription factor activity, and symplast and cell junction existed only in pairwise comparisons Day 7 vs Day 0 and Day 10 vs Day 0. KEGG enrichment analysis showed that metabolic pathway played an important role in the stress response to HG Type 0. Cellular processes, metabolism and organismal systems and other pathway-related genes increased significantly after 7 days. Transcription factor analysis showed that transcription factors such as MYB, AP2-EREBP, bHLH, WRKY and NAC may be involved in the anti-HG Type 0 response of Dongnong L-204. At the same time, few transient inducible transcription factors were found and more transient inhibited transcription factors in Dongnong L-204 in the early stage of HG Type 0 syncytial establishment. RT-qPCR was used to analyse expression of 10 genes closely related to the HG Type 0 stress response. The expression of GmWRKYX1 was >60 times higher at Day 10 after HG Type 0 stress than at Day 0. The WRKY transcription-factor family may play an important role in the resistance of Dongnong L-204 to HG Type 0 stress.
Integrating traditional knowledge, science and conservation in the search for undescribed mammals on Malaita, Solomon Islands
Authors: Lavery Tyrone H. , Alabai Masaafi , Esau Tommy , Fuiberi Simon , Furina Di'ifaka , Johnson Rebecca N. , Kekeubata Esau , MacLaren David , Waneagea Jackson , Flannery Tim F.
Published: June 2020

Basic knowledge of species diversity and distributions underpins the study of island biogeography and is fundamental for conservation planning. In Solomon Islands, new mammals continue to be described and several lineages are yet to be documented from large islands where, presumably, they should occur. On Malaita and Makira, no giant rats (Solomys or Uromys), or monkey-faced bats (Pteralopex) have been documented by scientists, but traditional knowledge suggests they exist. In East Kwaio, Malaita, we combined traditional knowledge and scientific methods to survey mammals and search for these taxa. Camera traps, mist nets, spotlight surveys, echolocation call recorders, rat traps and active searches were used to produce an inventory of the island’s mammals. No Solomys, Uromys or Pteralopex were captured. However, detailed accounts suggest that giant rats and monkey-faced bats were present as recently as 1996 and 2002 respectively. Moreover, we consider the presence of gnawed Canarium nuts an indicator that giant rats still persist. The human population of Malaita is dense, hunting pressure appears high, feral cats are common, and logging is rapidly reducing primary forests. A notable feature of this work has been the commitment towards collaboration and upskilling landowners in mammal survey techniques. This collaboration has helped fuel a growing conservation movement on Malaita and led to the designation of three large conservation areas. Gathering evidence for the existence of undescribed mammals on Malaita is paramount for reducing further extinctions in Melanesia. Continued support for skilled community members in East Kwaio will be key to collecting this evidence.
Influence of dung pats on soil physical quality mediated by earthworms: from dung deposition to decay and beyond
Authors: Bacher M. G. , Schmidt O. , Bondi G. , Fenton O.
Published: June 2020

Soil quality determines the ability of soil to deliver ecosystem services and can be inferred from physical, biological and chemical indicators either in isolation or in combination. Earthworms are good soil-quality indicators that contribute to both chemical and physical quality by maintaining soil structure and cycling nutrients. The presence of dung pats can increase earthworm abundance locally and consequently the network of pores that they create through their burrowing activity. Inevitably this affects soil structure and consequently will have a spatially distributed effect on soil physical quality (SPQ). The aim of this field study was to examine the relationship between SPQ and earthworm abundance under dung and non-dung pat areas from deposition to decay and beyond. The present spatial and temporal study compared SPQ indicator (integral air-water energy, AWr) results with earthworm abundance across control and simulated dung pat treatments. Results showed that existing earthworm populations in this grassland were already very large (>500 individuals m–2) and SPQ (AWr) remained in the ‘very good’ category throughout the experiment. Earthworm abundance under dung pats and SPQ exhibited a significant (P = 0.05) temporal trend. In general, the time of decay of the dung pats played a role in increasing earthworm abundance and SPQ. Earthworm abundance and macropore density data formed a similar, ‘hump’-shaped dynamic over time. However, when an earthworm abundance threshold was exceeded (equivalent to about >3000 individuals m–2), the increase of SPQ under dung was attenuated and did increase further only under the control sward with high earthworm abundance. After 11 weeks, for both treatments, AWr under dung pats was capped at 0.83% and AWr under control sward peaked at 1.34%. Future work should focus on (a) further exploration of the threshold where earthworm abundance becomes detrimental for SPQ and (b) using the AWr SPQ indicator within an actual grazed trial which incorporates a gradient of soil degradation.
The onset of the frictional motion of dissimilar materials
Authors: Shlomai Hadar , Kammer David S. , Adda-Bedia Mokhtar , Fineberg Jay
Published: June 2020

Frictional motion between contacting bodies is governed by propagating rupture fronts that are essentially earthquakes. These fronts break the contacts composing the interface separating the bodies to enable their relative motion. The most general type of frictional motion takes place when the two bodies are not identical. Within these so-called bimaterial interfaces, the onset of frictional motion is often mediated by highly localized rupture fronts, called slip pulses. Here, we show how this unique rupture mode develops, evolves, and changes the character of the interface’s behavior. Bimaterial slip pulses initiate as “subshear” cracks (slower than shear waves) that transition to developed slip pulses where normal stresses almost vanish at their leading edge. The observed slip pulses propagate solely within a narrow range of “transonic” velocities, bounded between the shear wave velocity of the softer material and a limiting velocity. We derive analytic solutions for both subshear cracks and the leading edge of slip pulses. These solutions both provide an excellent description of our experimental measurements and quantitatively explain slip pulses’ limiting velocities. We furthermore find that frictional coupling between local normal stress variations and frictional resistance actually promotes the interface separation that is critical for slip-pulse localization. These results provide a full picture of slip-pulse formation and structure that is important for our fundamental understanding of both earthquake motion and the most general types of frictional processes.
P-hacking in clinical trials and how incentives shape the distribution of results across phases
Authors: Adda Jérôme , Decker Christian , Ottaviani Marco
Published: June 2020

Clinical research should conform to high standards of ethical and scientific integrity, given that human lives are at stake. However, economic incentives can generate conflicts of interest for investigators, who may be inclined to withhold unfavorable results or even tamper with data in order to achieve desired outcomes. To shed light on the integrity of clinical trial results, this paper systematically analyzes the distribution ofPvalues of primary outcomes for phase II and phase III drug trials reported to the ClinicalTrials.gov registry. First, we detect no bunching of results just above the classical 5% threshold for statistical significance. Second, a density-discontinuity test reveals an upward jump at the 5% threshold for phase III results by small industry sponsors. Third, we document a larger fraction of significant results in phase III compared to phase II. Linking trials across phases, we find that early favorable results increase the likelihood of continuing into the next phase. Once we take into account this selective continuation, we can explain almost completely the excess of significant results in phase III for trials conducted by large industry sponsors. For small industry sponsors, instead, part of the excess remains unexplained.
Remote nongenetic optical modulation of neuronal activity using fuzzy graphene
Authors: Rastogi Sahil K. , Garg Raghav , Scopelliti Matteo Giuseppe , Pinto Bernardo I. , Hartung Jane E. , Kim Seokhyoung , Murphey Corban G. E. , Johnson Nicholas , San Roman Daniel , Bezanilla Francisco , Cahoon James F. , Gold Michael S. , Chamanzar Maysam , Cohen-Karni Tzahi
Published: June 2020

The ability to modulate cellular electrophysiology is fundamental to the investigation of development, function, and disease. Currently, there is a need for remote, nongenetic, light-induced control of cellular activity in two-dimensional (2D) and three-dimensional (3D) platforms. Here, we report a breakthrough hybrid nanomaterial for remote, nongenetic, photothermal stimulation of 2D and 3D neural cellular systems. We combine one-dimensional (1D) nanowires (NWs) and 2D graphene flakes grown out-of-plane for highly controlled photothermal stimulation at subcellular precision without the need for genetic modification, with laser energies lower than a hundred nanojoules, one to two orders of magnitude lower than Au-, C-, and Si-based nanomaterials. Photothermal stimulation using NW-templated 3D fuzzy graphene (NT-3DFG) is flexible due to its broadband absorption and does not generate cellular stress. Therefore, it serves as a powerful toolset for studies of cell signaling within and between tissues and can enable therapeutic interventions.
Midgap radiative centers in carbon-enriched hexagonal boron nitride
Authors: Koperski Maciej , Vaclavkova Diana , Watanabe Kenji , Taniguchi Takashi , Novoselov Kostya S. , Potemski Marek
Published: June 2020

Significance

Well‐defined defect centers play a crucial role in condensed-matter physics. That is particularly evident in the case of semiconductors and wide‐gap insulators, where midgap levels provide a number of versatile functionalities: from lasing to pressure sensing. Individual defects may become single-photon sources—crucial for applications in quantum technology. Recently, such defects have been observed in hexagonal boron nitride (hBN). Here, a method to fabricate stable and reproducible defects in hBN is introduced. Large bandgap of boron nitride allows the use of such defects in many quantum applications. Fabrication and characterization of such defects in hBN, which has become a relevant, emerging, wide-bandgap 2D material, is an important step toward novel functionalities of van der Waals heterostructures.
Final report, on-going key comparison BIPM.QM-K1, ozone at ambient level, comparison with EAA, September 2019
Authors: Viallon Joële , Idrees Faraz , Moussay Philippe , Wielgosz Robert , Wolf Andreas
Published: June 2020

As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone standard of Austria maintained by the Environment Agency Austria (EAA) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). The instruments have been compared over a nominal ozone amount-of-substance fraction range from 0 nmol/mol to 500 nmol/mol.

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
On the solution of direct and inverse multiple scattering problems for mixed sound-soft, sound-hard and penetrable objects
Authors: Rapún M–L
Published: June 2020

In this work we consider a scattering problem governed by the two-dimensional Helmholtz equation, where some objects of different nature (sound-hard, sound-soft and penetrable) are present in the background medium. First we propose and analyze a system of boundary integral equations to solve the direct problem. After that, we propose a numerical method based on the computation of a multifrequency topological energy based imaging functional to find the shape of the objects (without knowing their nature) from measurements of the total field at a set of observation points. Numerical examples show that the proposed indicator function is able to detect objects of different nature and/or shape and size when processing noisy data for a rich enough range of frequencies.
Nanophotonic quantum network node with neutral atoms and an integrated telecom interface
Authors: Menon Shankar G , Singh Kevin , Borregaard Johannes , Bernien Hannes
Published: June 2020

The realization of a long-distance, distributed quantum network based on quantum memory nodes that are linked by photonic channels remains an outstanding challenge. We propose a quantum network node based on neutral alkali atoms coupled to nanophotonic crystal cavities that combines a long-lived memory qubit with a photonic interface at the telecom range, thereby enabling the long-distance distribution of entanglement over low loss optical fibers. We present a novel protocol for the generation of an atom–photon entangled state which uses telecom transitions between excited states of the alkali atoms. We analyze the realistic implementation of this protocol using rubidium and cesium atoms taking into account the full atomic level structure and properties of the nanophotonic crystal cavity. We find that a high fidelity entangled state can be generated with current technologies.
Use of radar data for characterizing extreme precipitation at fine scales and short durations
Authors: Lengfeld Katharina , Kirstetter Pierre-Emmanuel , Fowler Hayley J , Yu Jingjing , Becker Andreas , Flamig Zachary , Gourley Jonathan
Published: June 2020

Extreme precipitation is one of the most devastating forms of atmospheric phenomenon, causing severe damage worldwide, and is likely to intensify in strength and occurrence in a warming climate. This contribution gives an overview of the potential and challenges associated with using weather radar data to investigate extreme precipitation. We illustrate this by presenting radar data sets for Germany, the U.S. and the UK that resolve small-scale heavy rainfall events of just a few km2 with return periods of 5 years or more. Current challenges such as relatively short radar records and radar-based QPE uncertainty are discussed. An example from a precipitation climatology derived from the German weather radar network with spatial resolution of 1 km reveals the necessity of radars for observing short-term (1–6 h) extreme precipitation. Only 17.3% of hourly heavy precipitation events that occurred in Germany from 2001 to 2018 were captured by the rain gauge station network, while 81.8% of daily events were observed. This is underlined by a similar study using data from the UK radar network for 2014. Only 36.6% (52%) of heavy hourly (daily) rain events detected by the radar network were also captured by precipitation gauging stations. Implications for the monitoring of hydrologic extremes are demonstrated over the U.S. with a continental-scale radar-based reanalysis. Hydrologic extremes are documented over ∼1000 times more locations than stream gauges, including in the majority of ungauged basins. This underlines the importance of high-resolution weather radar observations for resolving small-scale rainfall events, and the necessity of radar-based climatological data sets for understanding the small-scale and high-temporal resolution characteristics of extreme precipitation.
Research on observation method of along the contour of China coastline based on CASEarth Satellite
Authors: Zhaojun Hu
Published: June 2020

Facing the rugged complicated coastline in china, three ways including data smoothing algorithm based on Third-Order Bezier Curve, High-order Bezier curve fitting algorithm and curve fitting algorithm based on least squares method are used to generate a smooth contour of coastline by analysing coordinate of coastal city. In the meanwhile, setting a series of leading point that meet the constraints of performance of CASEarth satellite to guide the satellite’s centre of view to move along the contour, and giving best solution among the three methods by the comparison.
Explosion force and shape fitting based modelling of dynamic virtual crater deformation
Authors: Shao Xiaoyao , Xu Bingli , Niu Shulai , Jin Tao , Wang Shaoqin , Guo Congjie
Published: June 2020

The dynamic deformation of virtual terrain is an important research content to improve the dynamic adaptability of virtual geographic environment, which can support the research of disaster simulation, combat simulation and so on. It is also a novel method to support human-environment interaction research in the community of geographic information science. In this paper, the dynamic generation of bomb crater is taken as an example to study the construction method of virtual terrain deformation model. Starting from the formation process of crater in explosive mechanics, the deformation model is coupled with the calculation method to control the radius and depth of crater shape. Through the method of geometric fitting, the shape of crater is modeled in different regions and the basic crater model is established. On the basis of the basic model, the incidence angle of projectile is introduced to build the relationship model between crater deformation and incidence angle of projectile. Based on the Digital Terrain Model (DTM), the terrain data model is improved by coupling the radius coefficient and depth coefficient related to the geological characteristics, and the crater shape algorithm reflecting the geological characteristics is proposed. Finally, the Perlin noise is added to realize the disturbance of the elevation value of each position point in the crater zone. The simulation environment of crater deformation is established by Unity, and the crater model is simulated and verified. The results show that the crater model can basically reflect the impact of different projectile incidence angle, explosion equivalent and geological characteristics. The deformation state of crater is similar to the actual situation. The research results can provide support for the simulation of the dynamic process of the crater produced by the projectile touch-down explosion in the virtual battlefield environment.
Potentials of UAV Remote Sensing Data Carrier – A Case of Application in UAV Low Altitude Route—planning
Authors: Liao Xiaohan , Ye Huping , Xu Chenchen , Tan Junming , Yue Huanyin
Published: June 2020

Unmanned aerial vehicles (UAVs) are commonly applied for low-altitude remote sensing, and their effective flights generate a large amount of remote sensing data in centimeter-level resolution every day. UAV remote sensing has become an important new source for generating geographic big data. However, UAV remote sensing data is multi-source heterogeneous and disordered in management. To scientifically manage and maximize the utilization of UAV remote sensing data, the “UAV remote sensing data carrier” has been proposed. It features distribution of remote sensing tasks and exchange of rich datasets for various UAVs owned by individuals or organizations and thus has great application potential in low altitude with complex artificial and natural environments. The UAV low-altitude public air route is a commonly recognized solution to enable safe flights of UAVs in low altitude, which requires a variety of precise geographic data. Therefore, the UAV remote sensing data carrier can contribute to the construction of low-altitude public air routes. It can realize the three-dimensional geospatial data acquisition and dynamic information updates on routes, the service to route construction in various industries, and the support of real-time optimal path selection. Construction of low-altitude public air routes based on the carrier have already been applied in the UAV cloud regulation system “SkyGrid”, which is currently inadequately studied. Besides route construction, the carrier has great potential for further development of low-altitude airspace resources and reasonable use applications.
Design and implementation of planting information service system based on GIS
Authors: Jia Hu , Zhenyu Zhao , Qiulan Wu , Feng Zhang , Zhenyu Si , Cuihong Lu , Xia Geng
Published: June 2020

The information service of planting features various service content; scattered and isolated information; diversity of data source and format, as well as high cost of system operation. Since agricultural production decision-making and management have diversified demands on scientific and technological service, a GIS-based planting information service system was designed and developed. This system integrates the geographic information data and planting service thematic data, which is based on multi-source heterogeneous data integration, GIS spatial analysis, responsive framework and other technologies. Through various terminals such as computers and mobile phones, the system provides land circulation information inquiry, soil fertility analysis, crop variety selection, production materials purchase, agricultural technology guidance, labor employment recruitment, agricultural product sales and other comprehensive information services of the whole planting life cycle. It guides farmers to plant rationally, and helps farmers resolve the issues relating to information islands and the information shortage problem in production and life by “one-stop”, and increase the famers’ income. It can also provide decision-making gist for agricultural administrative departments to adjust planting structure, optimize the rural industrial layout and related policy formulation. Through demonstration in Zhucheng, a new model for serving “agriculture, rural areas and farmers” with surveying and mapping geographic information has been formed in terms of resource integration, geospatial data services, and service information access.
Behavior modeling method and its application in combat simulation
Authors: Shaoqin Wang , Bingli Xu , Shulai Niu , Xiaoyao Shao , Congjie Guo , Lin Li
Published: June 2020

Behavior Modeling and Simulation is an important method to analyze macro-and micro-behaviors of groups and individuals. It can predict and analyze the law of crowd activity under a certain density and provide important support for the study of social and economic activities and war and military activities. It has been widely used in emergency response, combat simulation and many other fields. This paper reviews behavioral modeling and simulation, mainly from the current situation of behavioral simulation applications, the main methods of behavioral modeling and the needs of future development direction. Firstly, the application status of behavior simulation is analyzed from both military and social aspects. In the aspect of social behavior simulation, it mainly analyses several aspects, such as safe evacuation, automatic driving, road traffic planning, intelligent robots and so on. In the aspect of military behavior simulation, it mainly analyses individual combat behavior simulation, battlefield element model construction, combat action combination model, multi-agent coupling simulation and so on. Secondly, the method of behavior modeling is deeply analyzed, and the main models of behavior modeling are summarized, including social force model, cellular automata model, agent model, etc. At the same time, the behavior model of individual’s multiple forces in a certain environment and the emergence effect model of group are deeply analyzed. Finally, based on the above two aspects of research and analysis results, this paper aims at the simulation of multi-person cooperative attack and defense, which is a military behavior simulation problem. From the four aspects of dynamic environmental factors, operational rules constraints, enemy threat factors and multi-agent cooperative control, this paper puts forward several problems that need to be further improved in cooperative attack and defense.
Application Engineering of Big Data Technology for Global Marine Environment Forecasting
Authors: Lin Bo , Xiao Fan
Published: June 2020

The thesis explained the construction and development path of the application engineering of big data technology for global marine environment forecasting: opening up a big data collection source global marine environment forecasting, developing the comprehensive data lake of marine environment forecasting, deeply digging the big data of marine environment forecasting, and applying multi-factor composite and multi-model coupled numerical forecasting method and combining with international scientific and technological cooperation and polar scientific expedition practice, to create the application engineering groups of big data technology for global marine environment forecasting. Secondly, the thesis introduced the overview, social and economic benefits of these application engineering groups of big data technology. Then, the current status, business technology level, and guarantee service capabilities of China’s data application of marine environment forecasting were shown in the big data level. Finally, from the perspective of forecasting experience and professional thinking, this study looked forward to the application prospects of big data in the global marine environment forecasting field as well as its technological changes and product (service) innovation.
Nitrate inversion based on remote sensing in the Pearl River Estuary, China
Authors: Lv Qiuxiao , Wang Difeng , Gong Fang , Bai Yan , He Xianqiang
Published: June 2020

Against a background of ongoing economic and industrial development, the impact of human activities on the offshore environment has become increasingly significant in recent years. In many regions, contamination of the marine environment necessitates the need for dynamic, real-time and wide-coverage water quality monitoring and satellite remote sensing, such that multi-temporal and spatial scale observation of various oceanic parameters are realized. In this paper, using salinity, in situ spectral data, nitrate and other water quality data from five sampling campaigns in the Pearl River Estuary and adjacent waters, studies on the inversion of nitrate concentrations using an artificial neural network were performed. Two inversion models, based on input of the measured salinity and field spectral data and just the field spectral data, were investigated. After comparing the accuracy of the two models, it was considered that the nitrate model with salinity and field spectral data as input performed best. Finally, the selected model was applied to MODIS data to achieve inversion of the nitrate concentrations in the estuary waters and obtain the temporal distribution of nitrate concentrations as a means to monitor and evaluate water quality in the estuary.
Verification and analysis of surface water in China based on Landsat8 OLI images
Authors: Jiang Wei , He Guojin , Pang Zhiguo , Long Tengfei , Fu JUNE , Guo Hongxiang , Ni Yuan
Published: June 2020

Surface water map is important to understand climate change and the hydrologic cycle and manage water resource. This study introduces multilayer perceptron (MLP) neural network to produce a surface water map of China in 2015 (SWMC-2015), Then, a new framework is created to generate a set of random water and not water validation points to assess the accuracy of the SWMC-2015. The overall accuracy and kappa coefficients of SWMC-2015 are 90% and 0.78, respectively. Finally, with the SWMC-2015, the spatial characteristics of surface water are comprehensively analysed at national, basin and province scales. The surface water area in China is 154,811.1 km2, accounting for 1.63% of the total land area. There are considerable differences in surface water abundance at both the basin and province scales. The water body areas are largest in the continental basin and Tibet, and water bodies cover the greatest percentage of total surface area in the Huaihe River Basin and Jiangsu.
Analysis of Spatial and Temporal Variations of Vegetation Index in Liaodong Bay in the last 30 years based on the GEE Platform
Authors: Zhou Chao , Li Fei , Zhang Jianli , Zhao Jianhua , Zhang Yun , Wang Jingwei
Published: June 2020

In order to determine the space-time characteristics of vegetation growing, aiming at the problems of poor efficiency in remote sensing information extraction of traditional methods, based on the Google Earth Engine (GEE) platform, NDVI data was extracted using Landsat image in the growing season from 1990 to 2019, and the space-time characteristics of vegetation were discussed with unitary linearity regression. The results showed that, 1) Taking 2010 as the turning point, NDVI of surface vegetation in Liaodong Bay showed a trend of first increase, then decrease and then increase during the past 30 years. The total area of vegetation cover have less change, while the proportion of medium-high coverage (0.6<NDVI<0.8) and high coverage (0.8<NDVI<1) increased significantly, 2) The spatial distribution of NDVI in Liaodong Bay have obvious differences, which shows a trend of gradual decrease from the Liaohe estuary delta to both sides. Affected by the development of coastal resources, NDVI increased firstly and then decreased from land to sea. In conclusion, the space-time change of NDVI in Liaodong Bay is affected by human development activities and ecological restoration. As an important quantitative factor, NDVI can provide basic data for the evaluation of environmental carrying capacity and ecological restoration.
Effects of spatial grain size on different types of cultivated land landscape pattern in fragmented agricultural landscapes based on GF-2 imagery
Authors: Wang Jingjing , Sun Ling , Wang Zhiming , Shan Jie , Huang Xiaojun , Li Mu
Published: June 2020

The landscape pattern of the cultivated land determines the type, number, distribution and the allocation of cultivated land resource, which could provide theoretical basis for ecological security research, provide reference for policy formulation. The high resolution satellite image provides macroscopic, real-time, fine and dynamic data source for the study of cultivated land landscape pattern. The study of spatial grain effects on the different types of cultivated land is an important part of the study of landscape pattern, and also provides a basis for the selection of suitable spatial resolution of remote sensing image. In this study, a concentrated area of cultivated land in the suburban area of Nanjing City in Jiangsu Province was taken as the study area. Based on the analysis of China high spatial resolution GF-2 image, different types of cultivated land in the study area were extracted, including rice, soybean, vegetables, fallow land and greenhouse cultivation. On this basis, a series of landscape pattern indices were used to analyse the effects of spatial grain size on different types of cultivated land landscape pattern characteristics. The Percentage of landscape index (PLAND) of five types of cultivated land in the study area remained stable with the increase of grain size and the Area weighted mean patch fractal index (FRAC_AM) of the five types of cultivated land landscape in the study area changed slightly especially the rice landscape. The Mean patch area (AREA_MN) and Mean nearest neighbour index (ENN_MN) increased in varying degrees with the increase of grain size, while Edge density (ED), Area weighted mean contiguity (CONTIG_AM) and Patch cohesion index (COHESION) decreased in varying degrees with the increase of grain size. Among the five types of cultivated land landscape, the ED and COHESION of soybean and fallow land decreased more obviously with the increase of grain size, and the AREA_MN a and ENN_MN of rice landscape increased most obviously with the increase of grain size.
Stand species identification using GF-2 imagery and airborne LiDAR data based on SVM classifier
Authors: Chen Caiyan , Jing Linhai
Published: June 2020

Stand species recognition is one of the key topics in forest research. The new GaoFen-2 (GF-2) satellite imagery contains detailed spectral and texture features. LiDAR data can provide abundant forest structure information. Using deep learning algorithms to identify forest types from optical and LiDAR data can improve recognition accuracy effectively. In this paper, the GaoFeng forest farm of Guangxi Zhuang Autonomous Region is taken as the experimental area, the mean and variance of GF-2 red-green-blue triple band spectra are taken as the spectral characteristics, and the corner two matrix, entropy, contrast and correlation in the gray level co-occurrence matrix are taken as the texture characteristics, a canopy height model (CHM) derived from LiDAR data is built as the structural characteristics, comparing the classification accuracy of using spectral feature, texture feature and structure information or spectral feature, texture feature based on SVM deep learning algorithm to classify in different resolution and different classification levels. The results show that the accuracy of the specific tree species classification by SVM classifier using 2 m-resolution fused GF-2 image combined with spectral, texture and structure features is high, the total classification accuracy is 95.65%, and Kappa coefficient reaches 0.93. As a contrast, the results of 4m-resolution fused GF-2 image using spectral and texture feature classification are poor. Combining the spectral and texture information of forest and the structural information reflected by LiDAR point cloud data can achieve significantly better classification results than each single feature. Compared with several traditional supervised classifiers, the new method needs less specialization and is more beneficial to the large-scale promotion of forestry classification.
Using SBAS-InSAR to Detect Surface Movement above Old Mining Areas after Mine Closure
Authors: Yu Zhigang , Huang Guoman
Published: June 2020

The impact of underground coal mining on the surface is not only manifested in the period of coal mining, but also after the coal mining stops and after the coal mine closes down, there will still be residual settlement, or the opposite movement - surface uplift. With the continuous development of microwave earth observation technology, time series InSAR technology has become one of the important means of surface deformation observation in mining areas. In this paper, SBAS-InSAR technology is applied to study the surface deformation movement in Lingzi coal mine, Shandong Province. The time series observations of Sentinel-1A/B data acquired from March 2015 to August 2019 were analyzed, it is found that the seasonal variation of atmosphere is more obvious under the short revisit period and long time series of satellite data, especially in mountainous areas. Considering this effect, the polynomial method is used to fit the observed results. The results show that the surface deformation in Lingzi coal mine is diverse. Some areas continue to uplift, with the maximum uplift of 69mm. Others first subsidence and then uplift, with the maximum subsidence of - 80mm. The process of subsidence and uplift is based on different mechanisms. The subsidence is the residual subsidence of underground caving caused by coal mining, and the process of uplift is related to the recharge of groundwater.
Improved performance of perovskite photodetectors with a hybrid planar-mixed heterojunction
Authors: Wu Hairuo , Chu Bei , Su Zisheng
Published: June 2020

Improved performance of lateral perovskite photodetectors is demonstrated based on a hybrid planar-mixed heterojunction structure, which comprises a CH3NH3PbI3:PC61BM ([6,6]-phenyl-C61-butyric acid methyl ester) bulk heterojunction on a planar SnO2 layer. The photodetector with an optimized PC61BM doping concentration shows a photocurrent more than three times to that device without a PC61BM doping or without a planar SnO2 layer, confirming that the hybrid planar-mixed heterojunction structure plays an important role in improving the performance of the devices. The photodetector exhibits a responsivity higher than 2 A W−1 in a wide range from ultraviolet to near infrared with a maximum one of 9 A W−1 at 315 nm. The improved performance is not only attributed to the increased electron transporting ability and the dissociation probability of excitons and/or electron-hole pairs in perovskite, but also to the growth of compact perovskite films with decreased grain boundary and hence the increased charge carriers transporting efficiency due to the introduction of PC61BM.
First-principles investigation on the bonding mechanism between graphyne and the (111) surface of Cu, Ag and Au
Authors: Sun Shenghui , Zhang Xin , Wang Shaoqing
Published: June 2020

A series of adsorption configurations with less than 2% lattice mismatch of graphyne adsorbed at different sites on the (111) surface of Cu, Ag and Au are obtained by a systematic rotation of the graphyne sheet. Besides, all the non-equivalent adsorption configurations of graphyne on metal surfaces are obtained by a structure screening method based on the translation of graphyne sheet and the calculation of the atomic overlapping area at the interface. The most stable adsorption configuration of graphyne on each metal surface is obtained by optimizing these non-equivalent adsorption configurations with a small computational cost. Then the adsorption energy, differential charge density, and partial density of states are calculated using a first-principles method in order to investigate the bonding mechanism between graphyne and the (111) surface of these three metals. The results show that the adsorption types of graphyne on the (111) surface of Cu, Ag and Au are chemisorption, chemical and physical mixed adsorption and pure physisorption, respectively. In detail, when a metal (Cu or Ag) atom is below a C atom, the C-pz orbital will interact with the s and d orbitals of the metal atom and then form a covalent bond with the metal atom. In particular, when a Cu atom lies below two carbon atoms joined by an acetylene bond, the s and d orbitals of the Cu atom hybridize with each other to form two identical sd orbitals and then form two covalent bonds with two C-pz orbitals. Our results not only provide a structure screening method for obtaining the most stable configuration with a very small lattice mismatch but also reveal the interface bonding mechanism between graphyne and metals, which will provide help for the preparation of graphyne and its application in composite materials.
The effects of interface and matrix reinforcements on fracture toughness of E-Glass/epoxy laminate
Authors: Saracoglu Goksel , Yapici Ahmet
Published: June 2020

In this study, the effects of low amount (0.1 wt%) multi-walled carbon nanotube (MWCNTs) distributed homogenously in epoxy via cationic surfactant (cetyl pyridiniumchloride-CPC), polyacrylonitrile nanofiber (in the range of 240–570 nm diameter) mats between each lamina, main fiber-matrix interface improvement using γ-Glycidoxypropyltrimethoxysilane and intermediate combinations were investigated on the fracture toughness of E-Glass/epoxy laminate. Considering the data obtained from three-point bending test samples with a single edge crack, it was found that the ultimate bending strength, modulus and fracture toughness of the silane-treated samples increased by 25.6%, 4.9 and 16.6% respectively, with respect to the reference sample. When MWCNTs was added to the silane treated sample, it was observed that it did not enhance the fracture toughness and decreased the strength and modulus slightly (1%) with the effect of CPC. The effect of 128 μm thick nanofiber mats on the silane-treated sample did not occur as expected and was found to cause delamination by working as a separate layer between the laminae.