bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gas‐phase formation of Grignard‐type organolanthanide (III) ions RLnCl3−: The influences of lanthanide center and hydrocarbyl group
Authors: Yang Meixian , Xiong Zhixin , Li Yangjuan , Chen Xiuting , Zhou Wei 
Published: March 2023

RationaleCompared with organomagnesium compounds (Grignard reagents), the Grignard‐type organolanthanides (III) exhibit several utilizable differences in reactivity. However, the fundamental understanding of Grignard‐type organolanthanides (III) is still in its infancy. Decarboxylation of metal carboxylate ions is an effective method to obtain organometallic ions that are well suited for gas‐phase investigation using electrospray ionization (ESI) mass spectrometry in combination with density functional theory (DFT) calculations.MethodsThe (RCO2)LnCl3− (R = CH3, Ln = La‐Lu except Pm; Ln = La, R = CH3CH2, CH2CH, HCC, C6H5, and C6H11) precursor ions were produced in the gas phase via ESI of LnCl3 and RCO2H or RCO2Na mixtures in methanol. Collision‐induced dissociation (CID) was employed to examine whether the Grignard‐type organolanthanide (III) ions RLnCl3− can be obtained via decarboxylation of lanthanide chloride carboxylate ions (RCO2)LnCl3−. DFT calculations can be used to determine the influences of lanthanide center and hydrocarbyl group on the formation of RLnCl3−.ResultsWhen R = CH3, CID of (CH3CO2)LnCl3− (Ln = La‐Lu except Pm) yielded decarboxylation products (CH3)LnCl3− and reduction products LnCl3·− with a variation in the relative intensity ratio of (CH3)LnCl3−/LnCl3·−. The trend is as follows: (CH3)EuCl3−/EuCl3·− < (CH3)YbCl3−/YbCl3·− ≈ (CH3)SmCl3−/SmCl3·− < other (CH3)LnCl3−/LnCl3·−, which complies with the trend of Ln (III)/Ln (II) reduction potentials in general. When Ln = La and hydrocarbyl groups were varied as CH3CH2, CH2CH, HCC, C6H5, and C6H11, the fragmentation behaviors of these (RCO2)LaCl3− precursor ions were diverse. Except for (C6H11CO2)LaCl3−, the four remaining (RCO2)LaCl3− (R = CH3CH2, CH2CH, HCC, and C6H5) ions all underwent decarboxylation to yield RLaCl3−. (CH2CH)LaCl3− and especially (CH3CH2)LaCl3− are prone to undergo β‐hydride transfer to form LaHCl3−, whereas (HCC)LaCl3− and (C6H5)LaCl3− are not. A minor reduction product, LaCl3·−, was formed via C6H5 radical loss of (C6H5)LaCl3−. The relative intensities of RLaCl3− compared to (RCO2)LaCl3− decrease as follows: HCC > CH2CH > C6H5 > CH3 > CH3CH2 >> C6H11 (not visible).ConclusionA series of Grignard‐type organolanthanide (III) ions RLnCl3− (R = CH3, Ln = La‐Lu except Pm; Ln = La, R = CH3CH2, CH2CH, HCC, and C6H5) were produced from (RCO2)LnCl3− via CO2 loss, whereas (C6H11)LaCl3− did not. The experimental and theoretical results suggest that the reduction potentials of Ln (III)/Ln (II) couples as well as the bulkiness and hybridization of hydrocarbyl groups play important roles in promoting or limiting the formation of RLnCl3− via decarboxylation of (RCO2)LnCl3−.
A discontinuous integral action for robust output tracking in uncertain linear systems
Authors: Gutiérrez Ariana , Ríos Héctor , Mera Manuel 
Published: March 2023

AbstractIn this article, a solution to the output tracking problem is proposed for linear systems affected by external disturbances. The proposed robust control approach has a discontinuous integral term that provides exact and finite‐time convergence to zero of the output tracking error in the presence of external disturbances. The proposed nonlinear controller is non‐homogeneous. A constructive method to compute the controller gains is provided in order to ensure the convergence to zero of the output tracking error. Some simulation results are presented in order to illustrate the feasibility of the proposed robust control approach.
Ultrathin Lithiophilic 3D Arrayed Skeleton Enabling Spatial‐Selection Deposition for Dendrite‐Free Lithium Anodes
Authors: Zhang Guanhua , Yu Huihuang , Li Du , Yan Yu , Wei Donghai , Ye Jinghua , Zhao Yanli , Zeng Wei , Duan Huigao 
Published: March 2023

AbstractLithium metal batteries are promising to become a new generation of energy storage batteries. However, the growth of Li dendrites and the volume expansion of the anode are serious constraints to their commercial implementation. Herein, a controllable strategy is proposed to construct an ultrathin 3D hierarchical host of honeycomb copper micromesh loaded with lithiophilic copper oxide nanowires (CMMC). The uniquely designed 3D hierarchical arrayed skeletons demonstrate a surface‐preferred and spatial‐selective effect to homogenize local current density and relieve the volume expansion, effectively suppressing the dendrite growth. Employing the constructed CMMC current collector in a half‐cell, >400 cycles with 99% coulombic efficiency at 0.5 mA cm−2 is performed. The symmetric battery cycles stably for >2000 h, and the full battery delivers a capacity of 166.6 mAh g−1. This facile and controllable approach provides an effective strategy for constructing high‐performance lithium metal batteries.
Efficient Fabrication of Micro/Nanostructured Polyethylene/Carbon Nanotubes Foam with Robust Superhydrophobicity, Excellent Photothermality, and Sufficient Adaptability for All‐Weather Freshwater Harvesting
Authors: Xie Heng , Du Yu , Zhou Weilong , Xu Wenhua , Zhang Congyuan , Niu Ran , Wu Ting , Qu Jinping 
Published: March 2023

AbstractThe integration of fog collection and solar‐driven evaporation has great significance in addressing the challenge of the global freshwater crisis. Herein, a micro/nanostructured polyethylene/carbon nanotubes foam with interconnected open‐cell structure (MN‐PCG) is fabricated using an industrialized micro extrusion compression molding technology. The 3D surface micro/nanostructure provides sufficient nucleation points for tiny water droplets to harvest moisture from humid air and a fog harvesting efficiency of 1451 mg cm−2 h−1 is achieved at night. The homogeneously dispersed carbon nanotubes and the graphite oxide@carbon nanotubes coating endow the MN‐PCG foam with excellent photothermal properties. Benefitting from the excellent photothermal property and sufficient steam escape channels, the MN‐PCG foam attains a superior evaporation rate of 2.42 kg m−2 h−1 under 1 Sun illumination. Consequently, a daily yield of ≈35 kg m−2 is realized by the integration of fog collection and solar‐driven evaporation. Moreover, the robust superhydrophobicity, acid/alkali tolerance, thermal resistance, and passive/active de‐icing properties provide a guarantee for the long‐term work of the MN‐PCG foam during practical outdoor applications. The large‐scale fabrication method for an all‐weather freshwater harvester offers an excellent solution to address the global water scarcity.
EVMFuzz: Differential fuzz testing of Ethereum virtual machine
Authors: Fu Ying , Ren Meng , Ma Fuchen , Yang Xin , Shi Heyuan , Li Shanshan , Liao Xiangke 
Published: March 2023

AbstractThe vulnerabilities in Ethereum virtual machine (EVM) may lead to serious problems for the Ethereum ecosystem. With lots of techniques being developed for the validation of smart contracts, the testing of EVM has not been well‐studied. In this paper, we propose EVMFuzz, the first that uses the differential fuzzing technique to detect vulnerabilities in EVM. The core idea of EVMFuzz is to continuously generate seed contracts for different EVMs' execution, so as to find as many inconsistencies among execution results as possible, and eventually discover vulnerabilities with output cross‐referencing. First, we present the evaluation metric for the internal inconsistency indicator. Then, we construct seed contracts via predefined mutators and employ a dynamic priority scheduling algorithm to guide seed contract selection and maximize the inconsistency. Finally, we leverage different EVMs as cross‐referencing oracles avoiding manual checking. For evaluation, we selected four widely used EVMs for the test, conducted large‐scale mutation on 36,295 real‐world smart contracts, and generated 253,153 smart contracts as initial seeds. Accompanied by manual root cause analysis, we found five previously unknown security bugs and all had been included in the common vulnerabilities and exposures (CVE) database.
A spatially adaptive large‐scale multiple‐testing procedure
Authors: Han Yixin , Wang Yunlong , Wang Zhaojun 
Published: March 2023

We consider a spatial multiple‐testing problem for large‐scale data with clustered signals. The clustering pattern of signals enlightens us to aggregate the neighbouring information for better statistical inference. We design a novel spatial‐assisted procedure via kernel‐based aggregation, automatically incorporating spatially localized mode of significant signal regions. More specifically, we utilize a sample‐splitting strategy to construct a series of marginal symmetric statistics and a data‐adaptive threshold for false discovery rate (FDR) control. Theoretical results show that the proposed method controls the desired FDR asymptotically under mild conditions. Simulation studies and a functional magnetic resonance imaging data application confirm the advantages of our methodology in terms of FDR control and power improvement.
Elementary school science teachers' discourse and on‐the‐job learning about student motivation
Authors: Sedawi Wisam , Eshchar‐Netz Livat , Yakovov Hasida , Vedder‐Weiss Dana 
Published: March 2023

AbstractScience teachers' professional learning about student motivation can play a key role in developing their ability to nurture student motivation and cope with motivational challenges. To advance the understanding of how on‐the‐job discussions facilitate teacher learning about student motivation, this study investigated how elementary‐school science teachers described and reasoned about student motivation in school‐based team meetings, by analyzing 20 audio‐recorded meetings of three Israeli elementary school science teams. The analysis included characterizing 123 episodes in which teachers referred to student motivation, coding how central and specific the references to motivation were, what indicators of motivation teachers addressed, and what influencing factors they considered. It also included a thematic analysis of teachers' discussions about motivation‐promoting methods and a microanalysis of one select event, drawing on linguistic ethnographic concepts and methods. The findings showed that teachers often addressed student motivation, but briefly and in relation to other topics. They tended to address behavioral and emotional indicators of motivation much more than cognitive indicators. They focused on instructional methods, predominantly addressing motivational issues from a practical perspective and seldom considering them from the student perspective or accounting for internal factors. Teachers often offered methods for promoting student motivation, but they expressed reservations without critically exploring them. Furthermore, critical discussions about motivation‐supporting methods were frequently constrained by teachers' attempts to manage the face threat these discussions entailed. These findings highlight how a theory‐crossing framework that integrates theories of student motivation with a theory of teacher productive discourse can serve as a guide for teachers' on‐the‐job discussions to develop their motivation‐related professional learning and their capacity to support student motivation.
Fetal cardiac function at midgestation and conception by in‐vitro fertilization
Authors: Huluta I. , Wright A. , Cosma L. M. , Dimopoulou S. , Nicolaides K. H. , Charakida M. 
Published: March 2023

ABSTRACTObjectiveTo assess differences in cardiac morphology and function at midgestation in fetuses conceived by in‐vitro fertilization (IVF), using fresh or frozen embryo transfer, compared with those conceived naturally.MethodsThis was a prospective study of 5801 women with a singleton pregnancy attending for a routine ultrasound examination at 19 + 0 to 23 + 6 weeks' gestation, including 343 that conceived by IVF. Conventional and more advanced echocardiographic modalities, including speckle‐tracking analysis, were used to assess fetal cardiac function in the right and left ventricles. The morphology of the fetal heart was assessed by calculating the right and left sphericity index. Placental perfusion and function were assessed by measurement of uterine artery pulsatility index (UtA‐PI) and serum placental growth factor (PlGF), respectively.ResultsFetuses that were conceived by IVF, compared with those conceived spontaneously, had significantly lower right and left ventricular sphericity index, higher left ventricular global longitudinal strain and lower left ventricular ejection fraction. There were no significant differences in any of the cardiac indices within the IVF group between the fresh and frozen embryo transfers. In the IVF group, compared with spontaneously conceived pregnancies, UtA‐PI was lower and PlGF was higher, suggesting better placental perfusion and function.ConclusionsOur study demonstrates that, in IVF pregnancies, compared with those conceived spontaneously, there is evidence of fetal cardiac remodeling at midgestation, which is not related to the use of fresh or frozen embryo transfer. In the IVF group, compared with naturally conceived pregnancies, fetal heart was globular and left ventricular systolic function was mildly reduced. Whether these cardiac changes are accentuated later in pregnancy and remain in the postnatal period remains to be established. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.
External validation of Fetal Medicine Foundation competing‐risks model for midgestation prediction of small‐for‐gestational‐age neonates in Spanish population
Authors: Albaiges G. , Papastefanou I. , Rodriguez I. , Prats P. , Echevarria M. , Rodriguez M. A. , Rodriguez Melcon A. 
Published: March 2023

ABSTRACTObjectiveTo examine the external validity of the new Fetal Medicine Foundation (FMF) competing‐risks model for prediction in midgestation of small‐for‐gestational‐age (SGA) neonates.MethodsThis was a single‐center prospective cohort study of 25 484 women with a singleton pregnancy undergoing routine ultrasound examination at 19 + 0 to 23 + 6 weeks' gestation. The FMF competing‐risks model for the prediction of SGA combining maternal factors and midgestation estimated fetal weight by ultrasound scan (EFW) and uterine artery pulsatility index (UtA‐PI) was used to calculate risks for different cut‐offs of birth‐weight percentile and gestational age at delivery. The predictive performance was evaluated in terms of discrimination and calibration.ResultsThe validation cohort was significantly different in composition compared with the FMF cohort in which the model was developed. In the validation cohort, at a 10% false‐positive rate (FPR), maternal factors, EFW and UtA‐PI yielded detection rates of 69.6%, 38.7% and 31.7% for SGA < 10th percentile with delivery at < 32, < 37 and ≥ 37 weeks' gestation, respectively. The respective values for SGA < 3rd percentile were 75.7%, 48.2% and 38.1%. Detection rates in the validation cohort were similar to those reported in the FMF study for SGA with delivery at < 32 weeks but lower for SGA with delivery at < 37 and ≥ 37 weeks. Predictive performance in the validation cohort was similar to that reported in a subgroup of the FMF cohort consisting of nulliparous and Caucasian women. Detection rates in the validation cohort at a 15% FPR were 77.4%, 50.0% and 41.5% for SGA < 10th percentile with delivery at < 32, < 37 and ≥ 37 weeks, respectively, which were similar to the respective values reported in the FMF study at a 10% FPR. The model had satisfactory calibration.ConclusionThe new competing‐risks model for midgestation prediction of SGA developed by the FMF performs well in a large independent Spanish population. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.
Spatially localized nonlinear magnetoelastic waves in an electrically conductive micropolar medium
Authors: Erofeev Vladimir I. , Malkhanov Alexey O. 
Published: March 2023

AbstractA nonlinear model of an electrically conductive micropolar medium interacting with an external magnetic field is proposed. The deformable state of such a medium is described by two asymmetric tensors: tensor of deformations and bending‐torsion tensor. Both tensors consider both linear and nonlinear terms in rotation and displacement gradients (geometric nonlinearity). The components of the bending‐torsion tensor which have the same indices, describe torsional deformations, while the rest describe bending deformations. The stress state of the medium is described by two asymmetric tensors: stresses tensor and moment stresses tensor. It is assumed, as is customary in magnetoelasticity, that the action of an electromagnetic field on a strain field occurs through Lorentz forces. From the system of Maxwell's equations follow the equations for electric and magnetic induction, which together with electromagnetic equations of state, should be added to the group of equations which describe the dynamics of a micropolar medium. In the frames of the proposed model, a one‐dimensional nonlinear magnetoelastic shear‐rotation wave is considered. In the equations of dynamics, a nonlinear term is considered. This term makes the most significant contribution to wave processes. It is shown that two factors will influence the wave propagation: dispersion and nonlinearity. Nonlinearity leads to the emergence of new harmonics in the wave, which contributes to the appearance of sharp drops in the moving wave profile. Dispersion, on the contrary, smoothed out differences due to differences in phase velocities of harmonic component waves. The combined action of these factors can lead to the formation of stationary waves that propagate at a constant speed without changing shape. Only those cases where a constant component is absent in the deformation wave are physically realizable. Stationary waves can be either periodic or aperiodic. The latter are spatially localized waves—solitons. It is shown that the behavior of “subsonic” and “supersonic” solitons will be qualitatively different.
Climate Governance in Eastern Africa: The Challenges and Prospects of Climate Change Adaptation Policies
Authors: Kweyu Raphael Mulaha , Asokan Shilpa Muliyil , Ndesanjo Ronald Boniphace , Obando Joy Apiyo , Tumbo Madaka Harold 
Published: March 2023

AbstractClimate governance leverages collaborative climate change adaptation actions. Despite many joint actions, gaps exist between policy and practice in climate adaptation among East African countries. Climate governance in East Africa takes cues from the state’s politics and policy structures underpinned by its level of political transformation. As such, climate governance confronts challenges common to all other policy sectors that integrate a complex mix of economic resource allocation and variables akin to the management of public affairs. This chapter identifies prebendalism, nepotism and political patronage in resource allocations. This chapter assesses the trends in climate change governance in East Africa. It addresses climate change policy frameworks on adaptation at regional, national and local governments, gaps between policy and practice of the nationally determined contributions (NDCs) and the management of climate-related conflicts. The chapter concludes by recommending further courses of action to strengthen climate governance among the local communities.
The Evolution of the Political Dimension of EU Co-operation with Eastern Africa
Authors: Laakso Liisa 
Published: March 2023

AbstractA significant element in the EU co-operation with Eastern Africa relates to the EU’s aspirations to support democracy worldwide. The Treaty of Nice of the EU (2001) explicitly stipulated that promoting human rights and freedoms should be part of all EU development and other co-operation with developing countries. This principle gained prominence and an explicit codification in the Cotonou Agreement between the EU and the African, Caribbean and Pacific states (ACP) between 2000 and 2022. The year 2022, when a new agreement is to be signed, is a good time to look back at the application of these principles. Has the EU been able to support democracy in Eastern Africa? To this end, this chapter pays attention to both positive and negative democratisation instruments. The positive instruments like the election observation missions (EOM) appear to be the public image of EU democracy support before everything else. Economic sanctions, particularly smart sanctions and suspension of development aid, are the most important negative instruments. Together, these instruments have become an increasingly important part of the AU and EU’s attempts to prevent the erosion of democratic institutions in its Eastern African partner countries.
Conclusion
Authors: Viola Lorella 
Published: March 2023

AbstractIn this final chapter, I review the main formulations of this book, and I retrace the key concepts and values at the foundation of the post-authentic framework that I proposed here. I reflect on why it is no longer sufficient to limit our observations to how the digital is impacting higher education and argue that it is time to ask a more fundamental question. As digital vs non-digital positions have entirely lost relevance, I reiterate that it has become increasingly futile to create ultra-specialised disciplines from other disciplines’ overlapping spaces; this is a legacy of last century’s model of knowledge. The digital transformation has magnified the inadequacy of such a mono-perspective approach and exposed the hypocrisy of a system which praises interdisciplinarity but forces knowledge into rigid categories. I end the chapter with a few additional propositions for remodelling the process of digital knowledge production that could be adopted to restructure academic and higher education programmes not just for today, but also for future generations.
Data Practices and Management
Authors: Roje Rea 
Published: March 2023

AbstractEmploying good data management practices is important for enhancing the transparency and validity of research, as well as the reproducibility of research findings. This chapter aims to help early career researchers translate the European Code of Conduct for Research Integrity principles and guidance on data management practices into everyday research. In this chapter we will guide you on data practices and management throughout the lifecycle of research data – data management planning, organizing and storing data, preserving and sharing data, reusing and citing data. You will also learn about the data management procedures relevant to each of the data lifecycle phases – preparation of data management plans, procedures for storing data properly and securely, examples of repositories for preserving and sharing data, licenses for reusing data, etc. The chapter will also outline the FAIR data principles and data protection requirements and safeguards important when handling personal data in your research (GDPR requirements, pseudonymization, anonymization, and deleting data).
How to Deal with Allegations of Misconduct
Authors: Marušić Ana , Roje Rea 
Published: March 2023

AbstractThis book is about good and responsible research but you have to be also aware of research misconduct and other unacceptable research practices that may occur during the research process. This chapter offers a guide on what is considered research misconduct, and what other behaviours are considered unacceptable research practices. Moreover, the chapter provides guidance on what to do if you have witnessed research misconduct or if you have been accused of a breach of research integrity. Besides the procedures, the chapter outlines the responsibilities and rights of those involved in the investigation process.