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This article traces the origins and development of public history in China, from its roots in historical memory in pre-modern times, through its role in shaping the nation in the period of modernization, to the emergence of histories of everyday life and popular histories in China today. It raises questions about what is public history in contemporary China, particularly the relationship between popular and academic history and the formalization of the field as seen in new institutions and a new journal.

International audience; A vast quantity of high-dimensional, unstructured textual news data is produced every day, more than two decades after the launch of the global Internet. These big data have a significant influence on the way that decisions are made in business and finance, due to the cost, scalability, and transparency benefits that they bring. However, limited studies have fully exploited big data to analyze changes in news diversity or to predict financial market movements, specifically stock market crashes. Based on modern methods of textual analysis, this paper investigates the relationship between news diversity and financial market crashes by applying the change-point detection approach. The empirical analysis shows that (1) big data is a relatively new and useful tool for assessing financial market movements, (2) there is a relationship between news diversity and financial market movements. News diversity tends to decline when the market falls and volatility soars, and increases when the market is on an upward trend and in recovery, and (3) the multiple structural breaks detected improve the ability to forecast stock price movements. Therefore, changes to news diversity, embedded in big data, can be a useful indicator of financial market crashes and recoveries.

International audience; In this paper, we introduce a functional method to investigate how betas change over time in factor models. Based on the China A-share data, we drop the constant beta assumption in the CAPM and multi-factor models to estimate the time-varying betas directly from the functional data regression. The empirical results show that exposures to all risk factors have certain time-varying patterns in the Chinese A-share stock market.

We develop and study sequential testing procedures a la Chu et al. (1996) for on-line detection of changes in a time series from stationarity to mild forms of non-stationarity. The proposed tests are based on sequential CUSUM and KPSS-type detector processes, and are shown to provide consistent detection under a wide range of change point models, including changes in the parameters of ARMA and GARCH series from values within the model’s stationarity parameter region to values close (converging) to the stationarity boundary. Local asymptotic results are established giving precise descriptions of the time to detection under several of these models, which show that such procedures are powerful to detect a wide range of non-stationary characteristics, including changes in mean, volatility, and unit root behaviour. The proposed methods are investigated by means of a simulation study and in applications to monitoring for changes in trend and unit root behaviour in macroeconomic production series, and to detect changes in volatility of the S&P-500 stock market index.

This paper introduces and studies the Heun-Racah and Heun-Bannai-Ito algebras abstractly and establishes the relation between these new algebraic structures and generalized Heun-type operators derived from the notion of algebraic Heun operators in the case of the Racah and Bannai-Ito algebras., Comment: 18 pages

International audience; In the context of connections between algebras coming from quantum integrable systems and algebras associated to the orthogonal polynomials of the Askey scheme, we prove that the truncated reflection algebra attached to the Yangian of sl2 is isomorphic to the Hahn algebra. As a by-product, we provide a general setup based on Euler polynomials to study truncations of reflection algebras.

The little and big q-Jacobi polynomials are shown to arise as basis vectors for representations of the Askey-Wilson algebra. The operators that these polynomials respectively diagonalize are identified within the Askey-Wilson algebra generated by twisted primitive elements of $\mathfrak U_q(sl(2))$. The little q-Jacobi operator and a tridiagonalization of it are shown to realize the equitable embedding of the Askey-Wilson algebra into $\mathfrak U_q(sl(2))$., v2: References added. 15 pp

We introduce Heun algebras of Lie type. They are obtained from bispectral pairs associated to simple or solvable Lie algebras of dimension three or four. For $\mathfrak{su}(2)$, this leads to the Heun-Krawtchouk algebra. The corresponding Heun-Krawtchouk operator is identified as the Hamiltonian of the quantum analogue of the Zhukovski-Voltera gyrostat. For $\mathfrak{su}(1,1)$, one obtains the Heun algebras attached to the Meixner, Meixner-Pollaczek and Laguerre polynomials. These Heun algebras are shown to be isomorphic the the Hahn algebra. Focusing on the harmonic oscillator algebra $\mathfrak{ho}$ leads to the Heun-Charlier algebra. The connections to orthogonal polynomials are achieved through realizations of the underlying Lie algebras in terms of difference and differential operators. In the $\mathfrak{su}(1,1)$ cases, it is observed that the Heun operator can be transformed into the Hahn, Continuous Hahn and Confluent Heun operators respectively., Comment: 15 pages

11 pages; International audience; An embedding of the Bannai–Ito algebra in the universal enveloping algebra of osp(1,2) is provided. A connection with the characterization of the little −1 Jacobi polynomials is found in the holomorphic realization of osp(1,2). An integral expression for the Bannai–Ito polynomials is derived as a corollary.

The q-Heun operator of the big q-Jacobi type on the exponential grid is defined. This operator is the most general second order q-difference operator that maps polynomials of degree $n$ to polynomials of degree $n+1$. It is tridiagonal in bases made out of either q-Pochhammer or big q-Jacobi polynomials and is bilinear in the operators of the q-Hahn algebra. The extension of this algebra that includes the q-Heun operator as generator is described. Biorthogonal Pastro polynomials are shown to satisfy a generalized eigenvalue problem or equivalently to be in the kernel of a special linear pencil made out of two q-Heun operators. The special case of the q-Heun operator associated to the little q-Jacobi polynomials is also treated., Comment: 10 pages. arXiv admin note: text overlap with arXiv:1808.00153

Two sets of mutually commuting $q-$difference operators $x_i$ and $y_j$, $i,j=1, ...,N$ such that $x_i$ and $y_i$ generate a homomorphic image of the $q-$Onsager algebra for each $i$ are introduced. The common polynomial eigenfunctions of each set are found to be entangled product of elementary Pochhammer functions in $N$ variables and $N+3$ parameters. Under certain conditions on the parameters, they form two `dual' bases of polynomials in $N$ variables. The action of each operator with respect to its dual basis is block tridiagonal. The overlap coefficients between the two dual bases are expressed as entangled products of $q-$Racah polynomials and satisfy an orthogonality relation. The overlap coefficients between either one of these bases and the multivariable monomial basis are also considered. One obtains in this case entangled products of dual $q-$Krawtchouk polynomials. Finally, the `split' basis in which the two families of operators act as block bidiagonal matrices is also provided., Comment: 21 pages. v3: Minor changes in the text

International audience; This paper develops a game model of a closed-loop supply chain consisting of one manufacturer, one remanufacturer and one retailer and investigates the long-term collection strategies of the manufacturer who needs to cooperate with the remanufacturer to develop the remanufacturing technology. The game model is developed from a fully dynamic perspective on the remanufacturing technology development and analyzed using the system dynamics method. We identify the trade-off in the choice of collection strategies: the early entry in the remanufacturing industry versus the complete control in the later stage. The simulation results show that when the entry barrier to the remanufacturing industry is low, the manufacturer can develop the remanufacturing technology in a short time and the direct reverse channel outperforms the indirect reverse channel; when the entry barrier is high, the manufacturer can achieve more profits under the indirect reverse channel by acquiring the remanufacturing technology directly from the remanufacturer. Moreover, the indirect reverse channel is more likely to be superior for low-barrier remanufacturing industry when the cost advantage is high as the early entry in the remanufacturing industry becomes more important than the complete control in the later stage.

How to evaluate the performance of decision-making units (DMUs) with fixed-sum outputs is a timely and challenging question in data envelopment analysis (DEA). Two major challenges are (1) how to determine a common equilibrium efficient frontier and (2) how to deal with multiple feasible equilibrium efficient frontiers. This paper first uses a simple dataset to illustrate the possibility of multiple equilibrium efficient frontiers and the corresponding major differences in the DMUs’ efficiencies and rankings resulting from these frontiers. We address these challenges by considering all feasible equilibrium efficient frontiers and develop several models to obtain the corresponding efficiency intervals, ranking intervals and dominance relations for the DMUs with fixed-sum outputs. We illustrate the proposed approach with two numerical examples and show that it gives more informative results than previous DEA approaches. For example, there are interesting dominance relations between DMUs under the fixed-sum outputs; yet these relations do not exist when there are no fixed-sum outputs. In addition, the efficiency ranges and ranking intervals can be narrowed by accounting for policy suggestions such as adjustment constraints of fixed-sum outputs for DMUs.

International audience; The idea for this book originates from reflections by the editors on the nature and dynamics of emerging research agendas on engineering. The book is based on our understanding of engineering and engineering education as an intrinsic socio- technical endeavor transcending the technical core–non-technical periphery dichot- omy. With backgrounds in engineering, social science, and the humanities, we have been developing and/or teaching courses for engineering students across the liberal arts-engineering divide for decades. During participation in research projects aimed at understanding and reforming engineering education we have published a series of books on engineering with contributions from a broad network of scholars from across the globe. This present book aspires to pull together the various strands of this trajectory of collaboration and to extend it in part by reflecting on the conversa- tions between engineers and non-engineers.

A confined electronic system can host a wide variety of fascinating electronic, magnetic, valleytronic and photonic phenomena due to its reduced symmetry and quantum confinement effect. For the recently emerging one-dimensional van der Waals (1D vdW) materials with electrons confined in 1D sub-units, an enormous variety of intriguing physical properties and functionalities can be expected. Here, we demonstrate the coexistence of giant linear/nonlinear optical anisotropy and high emission yield in fibrous red phosphorus (FRP), an exotic 1D vdW semiconductor with quasi-flat bands and a sizeable bandgap in the visible spectral range. The degree of photoluminescence (third-order nonlinear) anisotropy can reach 90% (86%), comparable to the best performance achieved so far. Meanwhile, the photoluminescence (third-harmonic generation) intensity in 1D vdW FRP is strong, with quantum efficiency (third-order susceptibility) four (three) times larger than that in the most well-known 2D vdW materials (e.g., MoS2). The concurrent realization of large linear/nonlinear optical anisotropy and emission intensity in 1D vdW FRP paves the way towards transforming the landscape of technological innovations in photonics and optoelectronics., One-dimensional van der Waals (1D vdW) materials derive interesting behaviour from dimensional confinement. Here the authors study a 1D vdW semiconductor, fibrous red phosphorous, and observe exceptional optical properties of large optical anisotropy and high photoluminescence.

International audience; Between 2012 and 2016, a systematic regional survey was conducted around the Xinhuang and Yueliang Lakes in northwest Jilin, Northeast China. This paper investigates the results of that fieldwork. We are especially interested in the degree to which the settlements are integrated with one another. The spatial analysis of the results shed new light on the local trajectory of settlement patterns and subsistence strategies from pre-Neolithic to the historical era, and provides data about the current and ancient environment and socio-economic changes in this region and how they differ from other nearby regions.

The CFP1 CXXC zinc finger protein targets the SET1/COMPASS complex to non-methylated CpG rich promoters to implement tri-methylation of histone H3 Lys4 (H3K4me3). Although H3K4me3 is widely associated with gene expression, the effects of CFP1 loss vary, suggesting additional chromatin factors contribute to context dependent effects. Using a proteomics approach, we identified CFP1 associated proteins and an unexpected direct link between Caenorhabditis elegans CFP-1 and an Rpd3/Sin3 small (SIN3S) histone deacetylase complex. Supporting a functional connection, we find that mutants of COMPASS and SIN3 complex components genetically interact and have similar phenotypic defects including misregulation of common genes. CFP-1 directly binds SIN-3 through a region including the conserved PAH1 domain and recruits SIN-3 and the HDA-1/HDAC subunit to H3K4me3 enriched promoters. Our results reveal a novel role for CFP-1 in mediating interaction between SET1/COMPASS and a Sin3S HDAC complex at promoters.

openaire: EC/H2020/820423/EU//S2QUIP Valley-contrasting Berry curvature and orbital magnetic moment have led to highly selective circular polarization of direct excitons at the K valleys in transition-metal dichalcogenides. In addition to K valleys, Q valleys, another critical point in the conduction band, also possess well-defined but distinct magnetic moment. Being akin to the direct excitons at K valleys, indirect excitons associated with Q (K) valleys in the conduction (valence) band could allow circular polarization in principle. Here, we report an experimental observation of the circular polarization of indirect Q-K transitions in noncentrosymmetric bilayer 3R-WS2. In stark contrast to the circular polarization of direct excitons which depolarizes with increasing lattice temperature, the circular polarization of indirect Q-K excitons is extremely robust and independent on the temperature. Such robust circular polarization can be understood as follows: The spin-orbit coupling in the Q valley is much stronger than that in the K point of the conduction band, significantly suppressing the temperature induced valley depolarization. Our results open up opportunities for exotic valleytronics and quantum information processing applications.

International audience; Chinese investments in African countries have increased massively in the last two decades. Critics have been vociferous for or against the Afro-Chinese relationship depending on their convictions making it a bit difficult to have an objective analysis on the issue.African nations and their leaders have repeatedly shown preference for Western culture and civilization due to or despite their respective and common historical experiences.When given the option, African states have always embraced Western companies and businesses. This can be seen in the larger majority of Western businesses established in the continent compared to those from other parts of the world.Foreign direct investments into Africa have also been traditionally from the West. But this preference for the West at least since the age of independence has not yielded the anticipated results. And this is the main reason why the Chinese are seen as an alternative today. Using the most recent research and data on this topic, this paper endeavors to analyze the nascent Chinese policies and investments in Africa comparing and contrasting their successes and failures compared to those of Western countries.

International audience; Chinese investments in African countries have increased massively in the last two decades. Critics have been vociferous for or against the Afro-Chinese relationship depending on their convictions making it a bit difficult to have an objective analysis on the issue.African nations and their leaders have repeatedly shown preference for Western culture and civilization due to or despite their respective and common historical experiences.When given the option, African states have always embraced Western companies and businesses. This can be seen in the larger majority of Western businesses established in the continent compared to those from other parts of the world.Foreign direct investments into Africa have also been traditionally from the West. But this preference for the West at least since the age of independence has not yielded the anticipated results. And this is the main reason why the Chinese are seen as an alternative today. Using the most recent research and data on this topic, this paper endeavors to analyze the nascent Chinese policies and investments in Africa comparing and contrasting their successes and failures compared to those of Western countries.

The Heun-Askey-Wilson algebra is introduced through generators $\{\boX,\boW\}$ and relations. These relations can be understood as an extension of the usual Askey-Wilson ones. A central element is given, and a canonical form of the Heun-Askey-Wilson algebra is presented. A homomorphism from the Heun-Askey-Wilson algebra to the Askey-Wilson one is identified. On the vector space of the polynomials in the variable $x=z+z^{-1}$, the Heun operator of Askey-Wilson type realizing $\boW$ can be characterized as the most general second order $q$-difference operator in the variable $z$ that maps polynomials of degree $n$ in $x=z+z^{-1}$ into polynomials of degree $n+1$., 16 pages

Intrinsic anomalous Nernst effect (ANE), like its Hall counterpart, is generated by Berry curvature of electrons in solids. Little is known about its response to disorder. In contrast, the link between the amplitude of the ordinary Nernst coefficient and the mean-free-path is extensively documented. Here, by studying Co$_3$Sn$_2$S$_2$, a topological half-metallic semimetal hosting sizable and recognizable ordinary and anomalous Nernst responses, we demonstrate an anti-correlation between the amplitude of ANE and carrier mobility. We argue that the observation, paradoxically, establishes the intrinsic origin of the ANE in this system. We conclude that various intrinsic off-diagonal coefficients are set by the way the Berry curvature is averaged on a grid involving the mean-free-path, the Fermi wavelength and the de Broglie thermal length., 10 pages, 9 figures, suppmental materials included

Two-dimensional (2D) atomic crystals have made major inroads into condensed-matter physics and give rise to fascinating phenomena due to quantum confinement. Here we report the first Raman scattering study on phonon-magnetic scattering coupling, proximate quantum spin liquid ground state and collective fractionalized excitations in exfoliated α-RuCl 3 atomic layers. Our results uncover that 2D α-RuCl 3 could harbour the unusual magnetic continuum, serving as a hallmark of the 2D proximate quantum spin liquid state and frustrated magnetic interactions. More importantly, our work demonstrates that the unusual magnetic scattering, as compared with bulk, is more obvious in 2D α-RuCl 3, indicating that the frustrated magnetic interactions are enhanced strongly. Such unusual enhancement of frustrated magnetic interactions may be responsible for the gigantic phonon-magnetic scattering coupling of 2D α-RuCl 3 and play a key role in stabilizing the 2D proximate quantum spin liquid state. Our work establishes a firm basis for exploring and understanding the 2D proximate quantum spin liquid and fractionalized excitations based on the atomically thin α-RuCl 3.

International audience; Nanobubbles have gained much attention due to their unusual properties such as large specific surface area, surface energy and internal energy, thereby, increase the surface reaction and improve the mass transfer efficiency. The long term stability of nanobubbles and generation of reactive oxygen species enables them to address various environmental issues for water purification without secondary pollution. However, there are few studies concerning the application of oxygen nanobubbles in the advanced oxidation processes (AOPs). In this study, first time, oxygen nanobubbles were introduced into the photoreaction system under visible light irradiation for enhanced photodegradation of oxytetracycline (OTC). Results indicated that oxygen nanobubbles significantly improved the photodegradation of OTC through high mass transfer and generation of reactive radicals during the nanobubble collapse. The oxygen nanobubble stability was confirmed to be pH dependent. The nanobubbles concentration increased from 0.76 to 3.78×108 particles/mL, while the mean size decreased from 205 nm to 138 nm as the pH value increased (3.2-11.0). The degradation efficiency of OTC was improved from 45% to 98% with the increase of pH (4.0-11.0). Oxygen nanobubbles hold promise to improve the AOPs, such as reducing catalysts and chemicals usage and costs. Quenching experiments demonstrated that •OH was the predominant active species induced the photodegradation of OTC. With the development of nanobubbles technology, it is anticipated to realize totally chemicals free green technology. This study provides a novel nanobubble/AOPs technology, which will be more efficient and environmental friendly and will have broad application in waste water treatment and drinking water purification.

International audience; Blockchain technology has very recently been involved in a wide range of extra-financial activities and is attracting a lot of interest in numerous sectors. The purpose of this paper is to discuss the implications of this technology for accounting, audit and control practices. Specifically, we will seek, in a prospective approach, to present this technology and to illustrate its innovative aspects, which will influence these activities in the years to come.; La technologie Blockchain, support de Bitcoin, se diffuse récemment à des activités extra financières variées et suscite un intérêt dans de nombreux secteurs d’activité. Cet article vise à discuter des conséquences à attendre de cette technologie pour les métiers du champ CCA. Plus précisément, nous chercherons, dans une approche prospective, à présenter cette technologie et à en illustrer les aspects novateurs, qui influenceront ces activités dans les années à venir.

International audience; Book Front Matter of LNCS 11276

Cyanobacterial blooms can cause serious damage to aquatic ecosystems. However, we have demonstrated that typical algae-blooming species Microcystis aeruginosa (M. aeruginosa) combined with photocatalysts could synergistically facilitate the photodecontamination of tetracycline hydrochloride (TC) and Cr(VI). In this study, for the first time, harmful algae were successfully converted into photoreactive bionano hybrid materials by immobilizing M. aeruginosa cells onto polyacrylonitrile (PAN)-TiO2/Ag hybrid nanofibers, and their photocatalytic activity was evaluated. The addition of M. aeruginosa significantly improved the photodecontamination, and the reaction rate constant (k) values of TC and Cr(VI) degradation by M. aeruginosa-PAN/TiO2/Ag nanofiber mats were 2.4 and 1.5-fold higher than that of bare PAN/TiO2/Ag nanofiber. Photoreaction caused damage to algae cells, but no microcystin was found that had been photodegraded simultaneously. The effects of various active species were also investigated, and the photodegradation mechanism was proposed. Recycling tests revealed that this flexible M. aeruginosa-PAN/TiO2/Ag hybrid mat had potential application in the removal of mixed organic and inorganic pollutants with high efficiency and without secondary pollutants. Thus, harmful algae blooms could serve as an efficient materials to remove toxic pollutants in a sustainable way under visible light irradiation.

Environmental enrichment (EE) has long been postulated as a behavioral treatment for drug addiction based on its preventive effects in animal models: rodents experiencing prior EE exhibit increased resistance to establishing drug taking and seeking. However, the therapeutic effects of EE, namely, the effects of EE when applied after drug exposure, are often marginal and transient. Using incubation of cue-induced cocaine craving, a rat relapse model depicting progressive intensification of cocaine seeking after withdrawal from cocaine self-administration, our present study reveals that after cocaine withdrawal, in vivo circuit-specific long-term depression (LTD) unmasks the therapeutic power of EE to achieve long-lasting anti-relapse effects. Specifically, our previous results show that cocaine self-administration generates AMPA receptor (AMPAR)-silent excitatory synapses within the basolateral amygdala (BLA) to nucleus accumbens (NAc) projection, and maturation of these silent synapses via recruiting calcium-permeable (CP) AMPARs contributes to incubation of cocaine craving. Here, we show that after cocaine withdrawal and maturation of silent synapses, the BLA-to-NAc projection became highly resistant to EE. However, optogenetic LTD applied to this projection in vivo transiently re-silenced these silent synapses by removing CP-AMPARs. During this transient window, application of EE resulted in the insertion of nonCP-AMPARs, thereby remodeling the "incubated" BLA-to-NAc projection. Consequently, incubation of cocaine craving was decreased persistently. These results reveal a mechanistic basis through which the persistent anti-relapse effects of EE can be unleashed after drug withdrawal.

c-Axis oriented Bi2Sr2Co2Oy thin films imbedded with Au nanoparticles were prepared by pulsed laser ablation a ceramic Bi2Sr2Co2Oy target with a small piece of Au foil overlapped. It was found that the incorporation of Au nanoparticles, about 5–15 nm in diameter, did not disrupt the c-axis orientation of the films. Fortunately, the incorporation of Au nanoparticles decreased the resistivity of Bi2Sr2Co2Oy films while maintained the Seebeck coefficient almost unchanged, thus resulted in an enhanced power factor. Possible mechanisms were proposed to explain the results. This work demonstrated a promising approach to optimize the thermoelectric performance of layered cobaltite thin films. Keywords: Thermoelectric, Layered cobaltite thin films, Au nanoparticles, Pulsed laser deposition

International audience

International audience; This research developed and tested a comprehensive model of the antecedents of international graduate students' interest in an international career. Based largely on Social Cognitive Career Theory (SCCT), the model included elements that pertain to perceptions of external constraints (perceptions of the labor market, family pressure to return), international student experience (adjustment in the foreign country during graduate studies, exposure and immersion to the international context) and individual factors (self-efficacy with respect to working abroad and outcome expectancy). Participants were 139 international graduate students in the UK. Individual factors and perceived constraints were directly related to interest in an international career. The factors that comprised current international student experience were indirectly related to interest via their relationship with self-efficacy, while adjustment moderated the relationship between self-efficacy and interest. Although the hypothesized moderating role of family pressure to return did not materialize, the findings suggest that perceptions of constraints play a more substantial role in the formation of interest than has been assumed by SCCT theory thus far. The findings are discussed with respect to their implications for the literature and for the policies of host country stakeholders.

International audience

International audience