bluuebunny/crossref_metadata_2025_split huggingface dataset:
Land-use intensity alters networks between biodiversity, ecosystem functions, and services
Authors: Felipe-Lucia María R. , Soliveres Santiago , Penone Caterina , Fischer Markus , Ammer Christian , Boch Steffen , Boeddinghaus Runa S. , Bonkowski Michael , Buscot François , Fiore-Donno Anna Maria , Frank Kevin , Goldmann Kezia , Gossner Martin M. , Hölzel Norbert , Jochum Malte , Kandeler Ellen , Klaus Valentin H. , Kleinebecker Till , Leimer Sophia , Manning Peter , Oelmann Yvonne , Saiz Hugo , Schall Peter , Schloter Michael , Schöning Ingo , Schrumpf Marion , Solly Emily F. , Stempfhuber Barbara , Weisser Wolfgang W. , Wilcke Wolfgang , Wubet Tesfaye , Allan Eric 
Published: October 2020

Significance
Ecosystem services derive from ecosystem functions and rely on complex interactions among a diversity of organisms. By understanding the relationships between biodiversity, ecosystem functions, and the services humans receive from nature, we can anticipate how changes in land use will affect ecosystems and human wellbeing. We show that increasing land-use intensity homogenizes the synergies between three organizational levels of the ecosystem, namely, biodiversity, ecosystem functions, and services. Increasing land-use intensity changes keystone components, which are important for the functioning of the ecosystem, and alters the synergies and trade-offs between biodiversity, ecosystem functions, and services. Our approach provides a comprehensive view of ecosystem functioning and can identify the key ecosystem attributes to monitor in order to prevent critical shifts in ecosystems.
Causal concept for black hole shadows
Authors: Siino Masaru 
Published: October 2020

Abstract
Causal concept for the general black hole shadow is investigated, instead of the photon sphere. We define several ‘wandering null geodesics’ as complete null geodesics accompanied by repetitive conjugate points, which would correspond to null geodesics on the photon sphere in Schwarzschild spacetime. We also define a ‘wandering set’, that is, a set of totally wandering null geodesics as a counterpart of the photon sphere, and moreover, a truncated wandering null geodesic to symbolically discuss its formation. Then we examine the existence of a wandering null geodesic in general black hole spacetimes mainly in terms of Weyl focusing. We will see the essence of the black hole shadow is not the stationary cycling of the photon orbits which is the concept only available in a stationary spacetime, but their accumulation. A wandering null geodesic implies that this accumulation will be occur somewhere in an asymptotically flat spacetime.
Development of static correlation functional using electron distribution on the energy coordinate
Authors: Takahashi Hideaki 
Published: October 2020

Abstract
A static correlation error (SCE) inevitably emerges when the dissociation of a covalent bond is described with a conventional density-functional theory (DFT) for electrons. The SCE gives rise to a serious overshoot in the potential energy (PE) at the dissociation limit even in the simplest molecules. The error is attributed to the basic framework of the approximate functional for the exchange correlation energy E
xc which refers only to local properties at coordinate
r
, namely, the electron density n(
r
) and its derivatives. To solve the problem we developed a functional

E

x
c

e

that uses the energy electron distribution n
e(ϵ) as a fundamental variable in DFT. n
e(ϵ) is obtained by projecting the density n(
r
) onto an energy coordinate ϵ defined by the external potential of interest. The functional was applied to the dissociations of single, double, and triple bonds in small molecules, showing reasonable agreement with the results given by a high-level molecular orbitals theory. We also applied the functional to the computation of the energy change associated with spin depolarization and symmetrization in a carbon atom, which made an improvement over the conventional functional. This work opens the way to develop a tougher functional that necessitates nonlocal properties of electrons, such as a kinetic energy functional.
Streamer propagation and pressure waves produced by a nanosecond pulsed surface sliding discharge: effect of the high-voltage electrode shape
Authors: Moreau E , Bayoda K , Benard N 
Published: October 2020

Abstract
This paper aims at better understanding nanosecond sliding discharges based on a three-electrode geometry and at studying the effect of the shape of the pulsed high-voltage electrode on their electrical, optical and mechanical properties. Three different electrode shapes are considered: a typical planar electrode with a straight edge, a planar electrode with a sawtooth edge, and a wire electrode. First, we verified that the sliding discharge starts to appear when the potential difference between both air-exposed electrodes exceeds about 25 kV, corresponding to a mean electric strength (potential difference divided by the gap) a little bit higher than 6 kV cm−1, but this value differs slightly depending on the shape of the electrode. Secondly, we highlighted that the current with the wire-based discharge is slightly higher compared to the two others because the streamers are more numerous and they are more uniformly distributed along the wire. Moreover, whatever the electrode shape, intensified charge-coupled device visualizations showed that many streamers initiate from the pulsed high-voltage electrode edge and propagate on the dielectric surface toward the DC voltage electrode at a mean velocity of about 1 mm ns−1. However, the streamer trajectory depends strongly on the electrode shape. Visualizations of the pressure waves induced by the different plasma actuators have been realized with a shadowgraph system. In the presence of a sliding discharge, every streamer is at the origin of three different pressure waves. The first hemispherical pressure wave results from streamer ignition at the edge of the pulsed high-voltage electrode, the head of the streamer acting as a point heat source. The second hemispherical pressure wave is due to the corona-type discharge that ignites from the negative DC high-voltage electrode when the streamer head gets closer. Finally, the third wave is a semi-cylindrical wave as each streamer acts as a line source of heat. To conclude, pressure measurements highlighted that the peak value of the pressure is nearly constant along the spanwise direction of the wire electrode as it presents high fluctuations with the sawtooth electrode, the maximum pressure being measured above the tips, where streamers are localized.
Atomistic investigation of mechanical properties of metallic glass nanocomposites
Authors: Zhou Xiaoling , Wang Longqi , Chen Changqing 
Published: October 2020

Abstract
In this paper, tensile deformation of metallic glass (MG) nanocomposites which consist of cellular MG matrix and columnar grains are studied by the molecular dynamic simulations. The size effects of the ligament thickness and the grain size on the yield strength and plasticity are elucidated. It is found that the ratio of the grain size to the ligament thickness (d/s) has a great influence on the plastic deformation. Two typical deformation mechanisms are further investigated. In the composite models with large d/s, grain boundaries motion and voids formation are the main mechanisms. When d/s decreases to 6, the grains can not only promote multiple shear bands formation but also impede the main shear band propagation. As a result, large plastic plateau appears in the stress–strain curve. These results are helpful to optimize the mechanical properties of MG composites.
Carbon nanotubes assembled on porous TiO2 matrix doped with Co3O4 as sulfur host for lithium–sulfur batteries
Authors: Qiu Weilong , Li Jing , Zhang Yongguang , Kalimuldina Gulnur , Bakenov Zhumabay 
Published: October 2020

Abstract
Advanced design and fabrication of high performance sulfur cathodes with improved conductivity and chemical adsorption towards lithium polysulfides (LiPS) are crucial for further development of Li–S batteries. Hence, we designed a TiO2/Co3O4-CNTs composite derived from Ti-MOF (MIL-125) as the host matrix for sulfur cathode. The polar nature of metal oxides (TiO2, Co3O4) creates the adsorptive sites in the composite and leads to an efficient chemical capture of LiPS. The CNTs ensure the contact between S/Li2S and the host material with high conductivity, enhanced charge transfer and fast electrochemical kinetics. At the same time, the CNTs strengthen the stability of the electrode material. Consequently, the as-prepared TiO2/Co3O4-CNTs composite showed excellent electrochemical performance. The cell with S–TiO2/Co3O4-CNTs delivers an initial specific capacity of 1270 mAh g–1 at 0.2 C and high rate performance with a capacity of 603 mAh g–1 at 3 C.
Plasma flux expansion control on the DIII-D tokamak
Authors: Anand H , Humphreys D , Eldon D , Leonard A , Hyatt A , Sammuli B , Welander A 
Published: October 2020

Abstract
A new controller has been developed with help of the flexible divertor poloidal-field coil set of the DIII-D tokamak, to aid in the precise control of the flux expansion in the scrape-off layer. The single-input multiple-output architecture ensures flexibility through a complementary set of orthogonal actuator direction to guarantee minimum effect on existing controlled variables, e.g. radial and vertical position control of the X-point. A non-linear free-boundary simulation code (GSevolve) is used for simulating the closed-loop response and for verifying the implementation of the control algorithm on the DIII-D plasma control system. First results of the experimental commissioning of the new controller during 2020 DIII-D campaign are also presented.
Effects of AlInN graded polarization-dependent doped top cladding on the performance of deep ultra-violet laser diode emitting at ∼271 nm wavelength
Authors: Paliwal Avinash , Singh Kuldip , Mathew Manish 
Published: October 2020

Abstract
This work presents the theoretical study on the polarization induced p-type doping of undoped-AlInN graded cladding layers for the deep ultra-violet laser diode (LD) emitting at around 271 nm wavelength. The reference LD consists of 320 nm of linearly graded undoped AlN-Al0.7Ga0.3N layer, while in our LD the graded undoped AlN-Al0.7Ga0.3N layer is replaced by the undoped AlN-Al
x
In(1−x)N composition graded layers with different x mole fraction from 0.88 to 0.92. The static device resistance for reference LD is ∼28.6 Ω which is reduced to ∼18.38 Ω for AlN-Al0.12In0.88N graded layer at 500 mA. The device resistance has been reduced dramatically by ∼10.2 Ω. The reduction in resistance is attributed to the increased polarization grading in AlN-Al0.12In0.88N. The large polarization grading leads to large hole carrier induction in the layer which increases the p-type conductivity of the undoped AlN-Al0.12In0.88N graded layer. Threshold current for reference LD is 393 mA which has been reduced to 384 mA for AlN-Al0.12In0.88N. The electron leakage has reduced from 0.9 kA cm−2 to 0.11 kA cm−2 at ∼30 kA cm−2 injected current density, whereas the hole transportation has improved from 29.23 kA cm−2 to ∼30 kA cm−2 at ∼30 kA cm−2 injected current density.
Mathematical modelling and experimental validation of a hybrid clutch combined with two modes: hydraulic and electrorheological fluid modes
Authors: Musiałek I , Kesy Z , Kesy A , Kim G W , Choi S B 
Published: October 2020

Abstract
The paper presents a mathematical modelling of a combined hydraulic clutch consisting of a hydrodynamic clutch and viscous clutches operating with electrorheological fluid and validates the mathematical model via an experimental evaluation. An electric field is generated in some of the clutches consisting in the combined hydraulic clutch, and it influences the electrorheological working fluid to alter characteristics of the clutch. The mathematical model formulated in this work, which is intended for analysis of different design solutions, is verified on the basis of the results achieved from bench testing. Based on the assessment of modelling errors, it is confirmed that the formulated mathematical model can be successfully employed in building clutches of this type applicable to torque transmission system.
Quantum proportional-integral (PI) control
Authors: Chen Hui , Li Hanhan , Motzoi Felix , Martin Leigh , Whaley K Birgitta , Sarovar Mohan 
Published: October 2020

Abstract
Feedback control is an essential component of many modern technologies and provides a key capability for emergent quantum technologies. We extend existing approaches of direct feedback control in which the controller applies a function directly proportional to the output signal (P feedback), to strategies in which feedback determined by an integrated output signal (I feedback), and to strategies in which feedback consists of a combination of P and I terms. The latter quantum PI feedback constitutes the analog of the widely used proportional-integral feedback of classical control. All of these strategies are experimentally feasible and require no complex state estimation. We apply the resulting formalism to two canonical quantum feedback control problems, namely, generation of an entangled state of two remote qubits, and stabilization of a harmonic oscillator under thermal noise under conditions of arbitrary measurement efficiency. These two problems allow analysis of the relative benefits of P, I, and PI feedback control. We find that for the two-qubit remote entanglement generation the best strategy can be a combined PI strategy when the measurement efficiency is less than one. In contrast, for harmonic state stabilization we find that P feedback shows the best performance when actuation of both position and momentum feedback is possible, while when only actuation of position is available, I feedback consistently shows the best performance, although feedback delay is shown to improve the performance of a P strategy here.
Dissolution of donor-vacancy clusters in heavily doped n-type germanium
Authors: Prucnal Slawomir , Liedke Maciej O , Wang Xiaoshuang , Butterling Maik , Posselt Matthias , Knoch Joachim , Windgassen Horst , Hirschmann Eric , Berencén Yonder , Rebohle Lars , Wang Mao , Napolitani Enrico , Frigerio Jacopo , Ballabio Andrea , Isella Giovani , Hübner René , Wagner Andreas , Bracht Hartmut , Helm Manfred , Zhou Shengqiang 
Published: October 2020

Abstract
The n-type doping of Ge is a self-limiting process due to the formation of vacancy-donor complexes (D
n
V with n ⩽ 4) that deactivate the donors. This work unambiguously demonstrates that the dissolution of the dominating P4V clusters in heavily phosphorus-doped Ge epilayers can be achieved by millisecond-flash lamp annealing at about 1050 K. The P4V cluster dissolution increases the carrier concentration by more than three-fold together with a suppression of phosphorus diffusion. Electrochemical capacitance–voltage measurements in conjunction with secondary ion mass spectrometry, positron annihilation lifetime spectroscopy and theoretical calculations enabled us to address and understand a fundamental problem that has hindered so far the full integration of Ge with complementary-metal-oxide-semiconductor technology.
Inherent uncertainty disguises attribution of reduced atmospheric CO2 growth to CO2 emission reductions for up to a decade
Authors: Spring Aaron , Ilyina Tatiana , Marotzke Jochem 
Published: October 2020

Abstract
The growth rate of atmospheric CO2 on inter-annual time scales is largely controlled by the response of the land and ocean carbon sinks to climate variability. Therefore, the effect of CO2 emission reductions to achieve the Paris Agreement on atmospheric CO2 concentrations may be disguised by internal variability, and the attribution of a reduction in atmospheric CO2 growth rate to CO2 emission reductions induced by a policy change is unclear for the near term. We use 100 single-model simulations and interpret CO2 emission reductions starting in 2020 as a policy change from scenario Representative Concentration Pathway (RCP) 4.5 to 2.6 in a comprehensive causal theory framework. Five-year CO2 concentration trends grow stronger in 2021–2025 after CO2 emission reductions than over 2016–2020 in 30% of all realizations in RCP2.6 compared to 52% in RCP4.5 without CO2 emission reductions. This implies that CO2 emission reductions are sufficient by 42%, necessary by 31% and both necessary and sufficient by 22% to cause reduced atmospheric CO2 trends. In the near term, these probabilities are far from certain. Certainty implying sufficient or necessary causation is only reached after, respectively, ten and sixteen years. Assessments of the efficacy of CO2 emission reductions in the near term are incomplete without quantitatively considering internal variability.
Repeated differentiation suppresses superoscillations
Authors: Berry M V 
Published: October 2020

Abstract
Two mathematical phenomena with applications in physics are: superoscillations, in which band-limited functions oscillate more rapidly than their fastest Fourier component; and the transformation of almost any smooth function into a monochromatic oscillation under repeated differentiation. These are opposite phenomena, and one mutates into the other, i.e. superoscillations are destroyed, as the number of derivatives increases. This behaviour is explained, and illustrated with an example.
Experimental study on the Solidification of silt by composite curing agent with fiber
Authors: Li Ding-ding , Zhou Xiao-guo , Mo Jian-bing 
Published: October 2020

Abstract
The influence of jute fiber and polyvinyl alcohol on the solidified silt was analyzed through the unconfined compressive strength test. The results showed that the addition of jute fiber and polyvinyl alcohol could not only improve the strength of the solidified silt, but also significantly improve the residual strength of the solidified soil. With the addition of fiber, the compressive strength of solidified soil increases first and then decreases with the increase of fiber content, and the optimal fiber content is 0.3%. The addition of PVA makes the compressive strength of solidified soil increase with the increase of fiber, and when the PVA content is 0.8%, the strength of solidified soil increases most obviously. Under the action of composite curing agent, the strength of solidified soil increases rapidly in the 1d-7d age, but decreases slowly in the 7d-14d age.
Evaluation Method of Highway Safety Maintenance Based on the Two-Dimensional Cloud Model Considering Equilibrium
Authors: Wang Jing-Chun , Zhang Xing-Xuan 
Published: October 2020

Abstract
In recent years, the total length of highways in service has been continuously increasing, and the demand for highway transportation has also increased. The damages and defects of highway and its supporting facilities with aging have serious effects on operation efficiency and driving safety. This paper studied the evaluation method of highway safety maintenance to assess the safety condition of highway and its supporting facilities. Firstly, an evaluation index system of highway safety maintenance was established from two major aspects: road structure and environment conditions, safety protection and management conditions. Secondly, the impact of discrete degree of index scores on the evaluation result of cloud model was analyzed, and then the equilibrium fine-tuning factor was proposed to improve the weighted mode between weights and scores. Based on the two-dimensional cloud model, a general process of safety evaluation considering the equilibrium fine-tuning factor was thus developed, and a cloud similarity algorithm based on the membership degree method was also proposed. Finally, a numerical study was carried out to validate the proposed model, and the sensitivity analysis of equilibrium significance α was conducted. The results showed that the impact of equilibrium fine-tuning factor on the comprehensive evaluation result is unneglectable, and the proposed method conforms to the reality of safety evaluation better, which can be applied in the highway safety maintenance evaluation for future reference.
Dynamic characteristics of external luminance of highway tunnel in cold area
Authors: Wang Yansong , Zhao Yuguo , Quan Qunshan , Cao Zhengmao 
Published: October 2020

Abstract
The external luminance of highway tunnels in cold areas is a key parameter for the lighting design of the tunnel entrance section. Due to the influence of the tunnel portal form, tunnel orientation, solar radiation intensity and solar irradiation angle, the external luminance of the tunnel varies with different seasons and different times. At present, there are relatively few studies on the time-varying characteristics of the external luminance of highway tunnels in cold areas. Relying on the Wunvfeng extra-long tunnel, combined with different tunnel opening orientations, the changes in the luminance of the tunnel exterior with time under several typical weather conditions are analyzed. The dynamic characteristics of the external luminance outside the tunnel in the cold area was obtained, which provide more detailed and reliable data for tunnel design. It has reference value for the lighting design and operation control of the entrance section of the tunnel and the design of light reduction outside the tunnel.
Multiple Classifier of Traffic Accident Based on Matter-Element Analysis
Authors: Sun Chao , Quan Wei 
Published: October 2020

Abstract
The paper establishes a new multiple classifier for grading the traffic accident based on the Hard Decision Model and the parallel topological structure. Logistic Regression, decision tree(DT) and BP Neural Network are selected as the base classifiers and matter-element analysis is employed as the fusion algorithm to improve the traditional topological structure. Matter-Element analysis has potential to increase the objectivity and dynamic in the criterion setting of the multiple classifier by combining the confidence coefficient of the base classification results. The accuracies of different base classifiers are used for weight factors calculation instead of the analytic hierarchy process (AHP) or the fuzzy synthetic evaluation (FSE) to avoid the influence of human factors. 200 recordings of the traffic accident are selected as a case study for methodology verification. The results show that compared with the base classifiers, the capacity to identify the class of traffic accident can be strengthened apparently by the multiple classifier based on confidence coefficient and Matter-Element Analysis Meanwhile, this classifier provides the best opportunity to avoid many bad conditions of single model, such as overfitting and under-fitting.
Construction and Operation of Logistics Parks: Insights from Bremen’s Experience
Authors: Wenwen Jiao , Shuo Su , Dachuan Ding 
Published: October 2020

Abstract
Logistics parks have made tremendous contributions not only to freight industry but also to the urban development and social benefits. We took German logistics and logistics parks as an illustration. Firstly, we introduced the definition and the status quo of German logistics and logistics parks, especially the development characteristics of the Bremen logistics park. Then we summarized both domestic and international theoretical researches on the relationship between government and logistics parks. By reviewing the practice of logistics parks in China, we pointed out the challenges and existing problems based on the actual situation of logistics development in China. At last, we put forward the relevant suggestions, which are beneficial to the development of logistics parks in China.