bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeled IMF By Effects on the Polar Ionosphere and Thermosphere Coupling
Authors: Liu Jing , Burns Alan G. , Wang Wenbin , Zhang Yongliang 
Published: February 2020

AbstractThere is still an inadequate understanding of how the interplanetary magnetic field (IMF) east‐west component (By) affects thermospheric composition, and other ionospheric and thermospheric fields in a systematic way. Utilizing the state‐of‐art first‐principles Coupled Magnetosphere Ionosphere Thermosphere (CMIT) modeling and TIMED/Global Ultraviolet Imager (GUVI)‐observed ΣO/N2 covering an entire solar cycle (year 2002–2016), as well as a neutral parcel trajectory tracing technique, we emphasize that not only the direction of By, but also its strength relative to the IMF north‐south component (Bz) that has important effects on high latitude convection, Joule heating, electron density, neutral winds, and neutral composition patterns in the upper thermosphere. The Northern Hemisphere convection pattern becomes more twisted for positive By cases than negative cases: the dusk cell becomes more rounded compared with the dawn cell. Consequently, equatorward neutral winds are stronger during postmidnight hours in negative By cases than in positive By cases, creating a favorable condition for neutral composition disturbances (characterized by low ΣO/N2) to expand to lower latitudes. This may lead to a more elongated ΣO/N2 depletion area along the morning‐premidnight direction for negative By conditions compared with the positive By conditions. Backward neutral parcel trajectories indicate that a lower ΣO/N2 parcel in negative By cases comes from lower altitudes, as compared with that for positive By cases, leading to larger enhancements of N2 in the former case.
Gassmann Consistency for Different Inclusion‐Based Effective Medium Theories: Implications for Elastic Interactions and Poroelasticity
Authors: Zhao Luanxiao , Cao Chenghao , Yao Qiuliang , Wang Yirong , Li Hui , Yuan Hemin , Geng Jianhua , Han De‐hua 
Published: February 2020

AbstractBy evaluating the consistency of the Gassmann theory with various inclusion‐based effective medium theories, we investigate the impact of elastic interactions between ellipsoidal pores on the poroelasticity. To rule out any factors that can violate the Gassmann condition, other than elastic interactions, we first construct idealized models that contain only a single set of isolated, identical, and vertically aligned ellipsoidal pores. The numerical simulation suggests that the periodic distribution of ellipsoidal pores generate uniform pore pressure distribution, whereas random distribution of ellipsoidal pores generates heterogeneous pore pressure distributions. Then we analyze the precise conditions under which the underlying Gassmann relationship is valid for various inclusion‐based models. The results reveal the following: (1) Noninteracting effective medium theories are always consistent with the Gassmann prediction, simply because the elastic interactions are ignored. (2) The elastic interactions between randomly distributed pores cause heterogeneous pore pressure that violates the essential requirement of the Gassmann theory. The differential effective medium and self‐consistent approximation theories corresponding to this model thus are inconsistent with the Gassmann prediction. (3) The elastic interactions between periodically distributed pores cause uniform pore pressure; therefore, the Gassmann condition is fully satisfied. The T‐matrix approach explicitly takes into account such elastic interactions and thus is consistent with the Gassmann theory. It is interesting to notice that on top of other well‐known common types of heterogeneities, like pore structure or fluid heterogeneities, the distribution of pores and its associated elastic interactions can be a separate source of heterogeneity, and this makes Gassmann equations not valid anymore.
Magmatic and Sedimentary Structure beneath the Klyuchevskoy Volcanic Group, Kamchatka, From Ambient Noise Tomography
Authors: Green Robert G. , Sens‐Schönfelder Christoph , Shapiro Nikolai , Koulakov Ivan , Tilmann Frederik , Dreiling Jennifer , Luehr Birger , Jakovlev Andrey , Abkadyrov Ilyas , Droznin Dima , Gordeev Evgeny 
Published: February 2020

AbstractThe Klyuchevskoy Volcanic Group is a cluster of the world's most active subduction volcanoes, situated on the Kamchatka Peninsula, Russia. The volcanoes lie in an unusual off‐arc position within the Central Kamchatka Depression (CKD), a large sedimentary basin whose origin is not fully understood. Many gaps also remain in the knowledge of the crustal magmatic plumbing system of these volcanoes. We conducted an ambient noise surface wave tomography, to image the 3‐D shear wave velocity structure of the Klyuchevskoy Volcanic Group and CKD within the surrounding region. Vertical component cross correlations of the continuous seismic noise are used to measure interstation Rayleigh wave group and phase traveltimes. We perform a two‐step surface wave tomography to model the 3‐D Vsv velocity structure. For each inversion stage we use a transdimensional Bayesian Monte Carlo approach, with coupled uncertainty propagation. This ensures that our model provides a reliable 3‐D velocity image of the upper 15 km of the crust, as well as a robust assessment of the uncertainty in the observed structure. Beneath the active volcanoes, we image small slow velocity anomalies at depths of 2–5 km but find no evidence for magma storage regions deeper than 5 km—noting the 15 km depth limit of the model. We also map two clearly defined sedimentary layers within the CKD, revealing an extensive 8 km deep sedimentary accumulation. This volume of sediments is consistent with the possibility that the CKD was formed as an Eocene‐Pliocene fore‐arc regime, rather than by recent (<2 Ma) back‐arc extension.
Patterns and Dynamics of SST Fronts in the California Current System
Authors: Mauzole Y. L. , Torres H. S. , Fu L.‐L. 
Published: February 2020

AbstractThe California Current System (CCS) is one of the four major Eastern Boundary Current Systems, where major coastal upwelling is observed in the ocean. Oceanic fronts are abundant in the CCS, and are known to be associated with coastal upwelling. Analyses of satellite observations (altimetry and sea surface temperature, SST) of the CCS highlight the presence of SST fronts in the southern part of the CCS outside of the coastal upwelling season, which will be investigated. The submesoscale‐permitting and tidal‐resolving LLC4320‐simulation was used to analyze the nature of these features, through the study of the surface density gradients, the vertical velocities and the horizontal strain. An algorithm was also developed to track SST fronts in the model. The classical scenario of coastal upwelling is confirmed in the central CCS (off California), with a strain field correlated to vertical velocities associated with the SST fronts, and collocated density fronts. In contrast, in the southern CCS (off Baja California), vertical velocities were much weaker and density gradients were not always observed where SST fronts were detected, leading to the assumption that the fronts there may be affected by thermohaline compensation occurring in the region. These findings confirm the existence of SST fronts in the CCS outside of the traditional coastal upwelling framework, with part of the fronts in the southern CCS being passive and advected by the background flow.
Ground‐Based Observations Reveal Unique Valley Precipitation Patterns in the Central Himalaya
Authors: Ouyang Lin , Yang Kun , Lu Hui , Chen Yingying , Lazhu  , Zhou Xu , Wang Yan 
Published: February 2020

AbstractWhile the Himalayas act as a natural barrier to water vapor transport to the Tibetan Plateau, many north‐south‐oriented valleys channel moisture onto the Plateau. However, owing to the lack of in situ data, the spatiotemporal characteristics of precipitation remain unclear along these valleys. In this study, a high‐altitude (2,800–4,500 m above mean sea level) rain‐gauge network was established in the Yadong Valley, one of the main valleys in the central Himalayan Region (CHR). New observations from this network are used to evaluate the Integrated Multi‐satellitE Retrieval for Global Precipitation Measurement (IMERG) precipitation product, with results demonstrating that the IMERG data can reproduce the seasonal and diurnal patterns of precipitation seen in the observational data. This combination of in situ and IMERG precipitation data reveals two unique characteristics in the CHR. First, precipitation during the premonsoon season (March‐May) contributes 20–40% of the annual total, from the high altitudes of the CHR to Southeast Tibetan Plateau, due to water vapor flux conveyed by southwesterlies from the Bay of Bengal, whereas this percentage is much lower in the northern Himalaya and South Asia. Second, diurnal variations in precipitation during the monsoon season (June‐September) vary between the low and high altitudes of the north‐south‐oriented valleys in the CHR: Precipitation at high altitudes has two peaks (one in the afternoon and the other at night), which is different from the single nighttime peak in low altitudes that is usually reported. These two notable spatiotemporal characteristics are indicative of the unique climate that exists at the high altitudes of the CHR.
Effects of Anthropogenic Activity on Global Terrestrial Gross Primary Production
Authors: Melnikova Irina , Sasai Takahiro 
Published: February 2020

AbstractGross primary production (GPP) has been identified as the largest terrestrial carbon flux and the major driver of the growing biosphere uptake of carbon. Factorial simulations using several biosphere models have been used to estimate the effects of long‐term (>50 years) climate change on global terrestrial GPP. However, no study has integrated large‐ensemble climate simulation data into a biosphere model to realistically estimate global terrestrial GPP with associated uncertainty. Here we present a novel approach to estimate the global terrestrial long‐term GPP with associated climate data‐induced uncertainty that combines a diagnostic‐type biosphere model with a large‐ensemble climate simulation data set. We distinguish the effects of recent anthropogenic activity on global GPP (the anthropogenic GPP effect) from the effects of interannual climate variability (the natural GPP effect) by comparing GPP model estimates forced by historical and “nonwarming” climate data. We provide evidence for an increasing anthropogenic effect on global terrestrial GPP. The anthropogenic GPP effect is driven by CO2 fertilization, which is projected to weaken or saturate by 2050–2150, depending on the representative concentration pathway scenario used. Model results suggest that shortwave radiation couples with El Niño–Southern Oscillation conditions and volcanic eruptions to drive the natural GPP effect. Because shortwave radiation at the surface is related to cloud cover, we encourage future studies to focus on cloud‐radiation feedbacks on the carbon cycle.
Crustal‐Scale Sheath Folding at HP Conditions in an Exhumed Alpine Subduction Zone (Tauern Window, Eastern Alps)
Authors: Groß Philip , Handy Mark R. , John Timm , Pestal Gerhard , Pleuger Jan 
Published: February 2020

AbstractWe investigate a well‐preserved paleo subduction channel that preserves a coherent part of the European continental margin exposed in the central Tauern Window (Eastern Alps), with the aim of testing models of sheath fold nappe formation and exhumation. The subduction zone was active during Paleogene convergence of the European and Adriatic plates, after closure of the Alpine Tethyan ocean. New cross sections and structural data together with new petrological data document a recumbent, tens of kilometers‐scale sheath fold in the center of the Tauern Window that formed during pervasive top‐foreland shear while subducted at high‐pressure (HP) conditions (~2.0 GPa, 500 °C) close to maximum burial depth. The fold comprises an isoclinally folded thrust that transported relicts of the former Alpine Tethys onto a distal part of the former European continental margin. The passive margin stratigraphy is still well preserved in the fold and highlights the special character of this segment of the European continental margin. We argue that this segment formed a promontory to the margin, which was inherited from Mesozoic rifting. In accordance with classical sheath fold theory, this promontory may have acted as an initial structural perturbation to nucleate a fold that was passively amplified to a sheath fold during top‐foreland shear in the subduction zone. The fold was at least partly exhumed and juxtaposed with the surrounding lower pressure units by opposing top‐hinterland and top‐foreland shear zones above and below, respectively, that is, in the sense of a nappe fold formed during channel‐extrusion exhumation.
Diagnostic Analysis of Bank Storage Effects on Sloping Floodplains
Authors: Liang Xiuyu , Zlotnik Vitaly A. , Zhang You‐Kuan , Xin Pei 
Published: February 2020

AbstractStream bank storage effects during floods have received limited attention, despite the significant role of such floods in aquifer water budgets. One reason is the complexity of geometry of the problem, which commonly has been treated numerically. Using a simple model in a domain with moving boundary, a semianalytical solution for bank storage effects is proposed to account for stream stage hydrograph, floodplain slope, and aquifer parameters. The results extend classic solutions by Cooper and Rorabaugh (1963, https://doi.org/10.3133/wsp1536J) for idealized vertical streambanks but applied to realistic floodplain cross sections. The accuracy of the semianalytical solution is verified by a one‐dimensional numerical method and compared to a vertical two‐dimensional variably saturated‐flow numerical model. Comparison indicates that a robust solution is valid for diagnostic analyses of modeling bank storage effects on floodplains. The semianalytical solution is applied to laboratory experiments as well. The results indicate that the present solution provides reasonable estimates of peak timing and head of groundwater flow response in the sloping bank during varying stream stage.
What Causes the Postmonsoon 18O Depletion Over Bay of Bengal Head and Beyond?
Authors: Cai Zhongyin , Tian Lide 
Published: February 2020

AbstractModern observations from Bay of Bengal (BOB) head have shown that precipitation δ18O value reaches the lowest stage during late postmonsoon when the summer monsoon has weakened or retreated, complicating the traditional interpretation of low δ18O value as strong monsoon. We show that this postmonsoon 18O depletion phenomenon exists from BOB periphery to the southeast and south Tibetan Plateau. Accumulative precipitation along back‐trajectory still explains daily precipitation δ18O variability during both the monsoon and nonmonsoon, thus indicating that longer‐term weighted‐mean δ18O is biased toward synoptic conditions during precipitation events. Further, we propose that transport of moisture from the east (west) of the India‐Burma Trough leads to depleted (enriched) 18O during the postmonsoon (premonsoon). Our results reconcile the apparent contradiction but beg the consideration of potential bias and influence of different precipitation regimes in paleo archives.
Single-agent activity of phosphatidylinositol 3-kinase inhibition with copanlisib in patients with molecularly defined relapsed or refractory diffuse large B-cell lymphoma
Authors: Lenz Georg , Hawkes Eliza , Verhoef Gregor , Haioun Corinne , Thye Lim Soon , Seog Heo Dae , Ardeshna Kirit , Chong Geoffrey , Haaber Jacob , Shi Wei , Gorbatchevsky Igor , Lippert Susanne , Hiemeyer Florian , Piraino Paolo , Beckmann Georg , Peña Carol , Buvaylo Viktoriya , Childs Barrett H. , Salles Gilles 
Published: February 2020

AbstractPatients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) have adverse outcomes. We evaluated the efficacy and safety of the phosphatidylinositol 3-kinase inhibitor copanlisib in patients with relapsed/refractory DLBCL and assessed the relationship between efficacy and DLBCL cell of origin (COO; activated B-cell like [ABC] and germinal center B-cell like [GCB]) and other biomarkers. The primary endpoint was objective response rate (ORR) in DLBCL COO subgroups (ABC, GCB, and unclassifiable) and by CD79B mutational status (NCT02391116). Sixty-seven patients received copanlisib (ABC DLBCL, n = 19; GCB DLBCL, n = 30; unclassifiable, n = 3; missing, n = 15). The ORR was 19.4%; 31.6% and 13.3% in ABC and GCB DLBCL patients, respectively. ORR was 22.2%/20.0% for patients with/without CD79B mutations (wild type, n = 45; mutant, n = 9; missing, n = 13). Overall median progression-free survival and duration of response were 1.8 and 4.3 months, respectively. Adverse events included hypertension (40.3%), diarrhea (37.3%), and hyperglycemia (32.8%). Aberrations were detected in 338 genes, including BCL2 (53.7%) and MLL2 (53.7%). A 16-gene signature separating responders from nonresponders was identified. Copanlisib treatment demonstrated a manageable safety profile in patients with relapsed/refractory DLBCL and a numerically higher response rate in ABC vs. GCB DLBCL patients.
5G camouflage antenna for pico‐cell base stations
Authors: Alieldin Ahmed , Huang Yi , Stanley Manoj , Xu Qian 
Published: February 2020

A camouflage dual‐polarised antenna for 5G pico‐cell (PC) base stations is proposed in this study. The antenna offers good coverage for the 5G sub‐6 GHz frequency band (3.3–3.8 GHz) with a reflection coefficient better than −15 dB and a port‐to‐port coupling less than −23 dB. The proposed antenna consists of two layers (a radiating layer and a feeding layer) separated by an air gap. The radiating layer uses a transparent conducting film (indium tin oxide) to form two patches (a radiating patch and a parasitic patch) printed on the opposite sides of a glass laminate. The radiating layer has visual transparency of 77%, which makes it possible to be integrated with the glass cover of the head of a street lamp while the feeding layer is embedded inside the head for camouflage. A 2 × 2 antenna array is formed to achieve a realised gain of 13.2 dBi and a 3‐dB solid angle of 33° × 33°. Therefore, the proposed design is very suitable to be employed as a camouflage 5G PC base station.
Inrush current reduction technology of DAB converter for low‐voltage battery systems and DC bus connections in DC microgrids
Authors: Kwak Bongwoo , Kim Myungbok , Kim Jonghoon 
Published: February 2020

Low‐voltage battery energy storage system and dual active bridge (DAB) converter control method for DC bus connection in DC microgrid. To use power efficiently in a DC microgrid, power must be easily transferred in both directions. DAB converters can easily transfer power in both directions using only the phase shift of the gate at 50% fixed duty on the primary and secondary sides. In the transient state, however, an overcurrent occurs to charge the output capacitor. A soft start algorithm is used to overcome this overcurrent problem. In the conventional method, the control complexity and response characteristics are slow because the duty control is included and the algorithm is performed in several stages. In this study, a gate drive circuit is constructed using a pulse transformer for 50% fixed duty control and short circuit protection. A soft start control algorithm is proposed, including a first‐order phase shift scheme for the stable soft start at 50% fixed duty. The 3 kW prototype DAB converter is designed and implemented for bidirectional power conversion testing. The experimental results show that stable power transfer is achieved in the initial transient state through bidirectional output control and soft start.
Modelling and optimisation of a dual‐control MHz‐level CLLC converter with minimised power losses in battery charging applications
Authors: Zhang Zeyu , Khaligh Alireza 
Published: February 2020

In this study, a novel ‘’ dual‐control modulation is proposed for the MHz‐level CLLC converters in battery charging applications. Phase shift between the primary and secondary switches is utilised as an additional control variable to effectively reduce the power losses, especially in light‐ and medium‐load conditions. Compared to other state of the art, a more generalised theoretical model is developed to characterise the converter with higher accuracy based on extended harmonic approximation. Furthermore, a numerical algorithm is utilised to thoroughly examine the converter performance under various operating conditions and systematically search for the optimised design parameters under the proposed modulation scheme. The modelling and optimisation are verified by simulation on a 3.3 kW onboard charger design for electric vehicles, which shows an estimated efficiency enhancement between 1 and 4%. Finally, a laboratory prototype has been developed using gallium nitride semiconductor devices, at the resonant frequency of 1 MHz. The converter measured efficiencies are 96.4, 96.2 and 94% for the selected heavy, medium‐ and light‐load conditions, respectively. This system would allow insights into the practical implementation and evaluation of utilising wide bandgap semiconductors to achieve both high power density and enhanced efficiency for emerging power electronic systems.
Dual range flyback topology for high efficiency at dual voltage mains
Authors: Ezra Noam , Long Teng 
Published: February 2020

This study introduces a dual range flyback converter, which overcomes low efficiency of the conventional flyback converter for universal mains voltages, i.e. 220 and 110 V AC mains. The topology comprises of reconfigurable primary power loops enabled by additional state switches. This combination allows the converter to run in parallel or series modes, enhancing the performance at 220 V AC high line or 110 V AC low line mains. It reduces the voltage rating of devices, supports two working points that operate in boundary conduction mode under fixed frequency and improves the utilisation of the devices. A 100 kHz, 60 W, 110 V AC or 220 V AC to 13 V DC converter has been designed and tested. The experimental results of the proposed converter have been compared against a conventional flyback converter. The results show a small improvement of performance at low voltage (110 V AC) and considerable performance improvement at high voltage (230 V AC): 0.6 and 2.3% efficiency improvement at full load, respectively.