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This paper investigates operational decisions and online channel mode selection for green products with an e-commerce supply chain in which the manufacturer is subject to capital constraint. Starting from a Stackelberg game framework where the platform acts as a leader, two different online channel modes applied with an e-commerce supply chain are explored for equilibria, respectively. This paper then extends to a different supply chain with a reversed channel leadership, so as to reveal how the supply chain leaderships affect the equilibriums and supply chain performance. With the analytical studies, several important and interesting insights are derived. For example, but not limited to, the following is found: (a) the equilibrium decisions of the capital-constrained supply chain highly rely on the associated interest rate but are independent of the initial capital level of the financially-constrained manufacturer; (b) the platform and the capital-constrained manufacturer act largely differently when choosing the optimal online channel mode for themselves; (c) a win-win situation benefiting two parties holds when and only when the two members choose the agency mode under certain conditions; (d) the impacts of the supply chain leaderships and online channel modes on the consumer surplus and social welfare are clearly revealed. These results derived in our paper shed lights on industrial practicer on how to effectively make such decision-making in platform economy. The members in an e-commerce supply chain can appropriately determine their decisions such as commission and slotting fee to reach a win-win situation for two parties.

The emission from the accreting black holes (BHs) in low-mass X-ray binaries (LMXBs) covers a broad energy band from radio to X-rays. Studying the correlations between emission in different energy bands during outbursts can provide valuable information about the accretion process. We analyse the simultaneous optical, ultraviolet (UV) and X-ray data of the BH-LMXB Swift J1753.5-0127 during its $\sim$ 12-year long outburst with the {\it Neil Gehrels Swift Observatory}. We find that the UV/optical and X-ray emission are strongly correlated during the hard states of the outburst. We fit the relation with a power-law function $F_{UV/optical} \propto F_{X}^{\beta}$ and find that the power-law index $\beta$ increases from $\sim$ 0.24 to $\sim$ 0.33 as the UV/optical wavelength decreases from $\sim$ 5400 \r{A} (V) to $\sim$ 2030 \r{A} (UVW2). We explore the possible reasons for this and suggest that in Swift J1753.5-0127 the UV/optical emission is dominated by a viscously heated accretion disc at large radii. We find that the data that deviate from the correlation correspond to the low-intensity peaks appeared in the X-ray band during the outburst, and suggest that these deviations are driven by the emission from the inner part of the accretion disc., Comment: 15 pages, 8 figures, 1 table, accepted by MNRAS

There are many problems such as strong subjectivity, complex calculations, and lack of intelligence in most of the current energy system evaluation models, so a design of an evaluation system for urban smart energy systems based on an improved genetic algorithm-back propagation (BP) neural network is proposed. First of all, the hierarchical structure of the indicator evaluation system for energy system was established, analytic hierarchy process (AHP) was used to assign weights to each indicator, and data samples were classified. Then, SeqGAN was used to expand the data set, which solved the difficult problem of data acquisition. Finally, the genetic algorithm was used to determine the best initial values of the weights and thresholds of the BP neural network structure parameters designed for this research. The simulation experiment results showed that the method in this paper has higher classification accuracy than the traditional method, and comprehensive evaluation model proposed can effectively evaluate the urban smart energy system.

N-Hydroxyethyl-substituted 1,2,3,4-tetrahydroquinolines were synthesized by the reaction of 2-(phenylamino)ethanol with unsaturated ketone catalyzed by acidic ionic liquid N-methyl-2-pyrrolidonium dihydrogen phosphate [NMPH]H2PO4, obviating the need for toxic and expensive catalysts. The acidic ionic liquid not only showed superior performance over H3PO4 but also was stable and could be reused at least five times with a slight loss of activity. It provided a straightforward and efficient protocol for the synthesis of 1,2,3,4-tetrahydroquinoline derivatives.

Based on our previous work, a safer and more sustainable protocol for the synthesis of N-(2-Hydroxyethyl)anilines has been developed. The synthesis included the selective alkylation reaction of aniline with 2-chloroethanol in H2O, eliminating the need for any catalysts and solvents during synthesis. Comparing with our previous work, the salient features of this methodology are eco-friendliness, economic benefit, and the ease of obtaining target compounds. The selective alkylation reaction in H2O is amenable to scale-up for the synthesis of N-(2-Hydroxyethyl)anilines. A green and efficient alternative way for the industrial synthesis of N-hydroxyethyl anilines was developed, eliminating the need for toxic and expensive catalysts and volatile organic solvents. The selectivity of N-hydroxyethyl anilines obtained in H2O are significantly increased in comparison to those traditional methods.

We present for the neutron-star low-mass X-ray binary 4U 1636–53, and for the first time for any source of kilohertz quasi-periodic oscillations (kHz QPOs), the two-dimensional behaviour of the fractional rms amplitude of the kHz QPOs in the parameter space defined by QPO frequency and photon energy. We find that the rms amplitude of the lower kHz QPO increases with energy up to $\sim \!\!12$ keV and then decreases at higher energies, while the rms amplitude of the upper kHz QPO either continues increasing or levels off at high energies. The rms amplitude of the lower kHz QPO increases and then decreases with frequency, peaking at $\sim \!\!760$ Hz, while the amplitude of the upper kHz QPO decreases with frequency, with a local maximum at around $\sim \!\!770$ Hz, and is consistent with becoming zero at the same QPO frequency, $\sim \!\!1400$ Hz, in all energy bands, thus constraining the neutron-star mass at $M_{NS} \le 1.6 \, \mathrm{M}_{\odot }$, under the assumption that this QPO reflects the Keplerian frequency at the inner edge of the accretion disc. We show that the slope of the rms energy spectrum is connected to the changing properties of the kHz QPOs in different energy bands as its frequencies change. Finally, we discuss a possible mechanism responsible for the radiative properties of the kHz QPOs and, based on a model in which the QPO arises from oscillations in a Comptonizing cloud of hot electrons, we show that the properties of the kHz QPOs can constrain the thermodynamic properties of the inner accretion flow.

We studied five XMM-Newton observations of the neutron-star binary 4U 1728$-$34 covering the hard, intermediate and soft spectral states. By jointly fitting the spectra with several reflection models, we obtained an inclination angle of 25$-$53$\deg$ and an iron abundance up to 10 times the solar. From the fits with reflection models, we found that the fluxes of the reflection and the Comptonised components vary inconsistently; since the latter is assumed to be the illuminating source, this result possibly indicates the contribution of the neutron star surface/boundary layer to the disc reflection. As the source evolved from the relatively soft to the intermediate state, the disc inner radius decreased, opposite to the prediction of the standard accretion disc model. We also explore the possible reasons why the supersolar iron abundance is required by the data and found that this high value is probably caused by the absence of the hard photons in the XMM-Newton data., Comment: 14 pages, 6 figures

Noise is an unneglectable problem in emotion recognition if we want to put it into practice. First, aiming at the problem of noise in speech, we design a new acoustic feature, Long time frame Analysis Weighted Wavelet Packet Cepstral Coefficient (LW-WPCC), for better robustness. To extract LW-WPCC feature, first the best wavelet packet basis is constructed. On the basis of this, a robust wavelet packet Cepstral Coefficient is extracted by combining short time frame analysis with long time frame analysis. After that, we introduce a sub-band spectral center-of-mass parameter with good robustness to additive noise and propose an extraction algorithm of LW-WPCC. Through experiments on speech emotion recognition of different SNR levels, it is shown that our proposed method shows better noise robustness and performance on speech emotion recognition. What's more, as facial expressions will not be affected by noise, we do bio-modal emotion recognition based on audio-visual data to improve robustness by making a decision-level fusion. Experiments based on audio-visual data are conducted to evaluate efficiency of our method. Results show that bio-modal emotion recognition based on audio-visual data can improve robustness and achieve better performance by benefiting from different kinds of emotion data.

The evaluation and selection process can be regarded as a complex multiple criteria decision analysis (MCDA) problem which involves various interaction relationships among criteria under high uncertain environment. In addition, the decision-makers are always bounded rational in the risk decision-making process. However, the current robot evaluation and selection approach seldom considers the decision-maker’s risk preference and interactive criteria under high uncertain environment. Thus, the purpose of this paper is to develop a hybrid MCDA approach for solving the robot evaluation and selection problem. In the proposed framework, the interval type-2 fuzzy set is used to express the uncertain evaluation information provided by decision-makers. Next, the distance measure of interval type-2 fuzzy numbers is developed to determine the fuzzy measure of each criterion. Then, the extended prospect theory based on developed Choquet integral is proposed to evaluate and prioritize the robot by considering the decision-maker’s risk preference and interactive criteria. Finally, a case study of robot evaluation and selection in the auto industry is selected to exemplify the application of the proposed framework. After that, comparison and sensitivity studies are conducted to further demonstrate the robustness, effectiveness, and reasonableness of the developed approach.

We have found and analysed 16 multi-peaked type-I bursts from the neutron-star low mass X-ray binary 4U 1636$-$53 with the Rossi X-ray Timing Explorer (RXTE). One of the bursts is a rare quadruple-peaked burst which was not previously reported. All 16 bursts show a multi-peaked structure not only in the X-ray light curves but also in the bolometric light curves. Most of the multi-peaked bursts appear in observations during the transition from the hard to the soft state in the colour-colour diagram. We find an anti-correlation between the second peak flux and the separation time between two peaks. We also find that in the double-peaked bursts the peak-flux ratio and the temperature of the thermal component in the pre-burst spectra are correlated. This indicates that the double-peaked structure in the light curve of the bursts may be affected by enhanced accretion rate in the disc, or increased temperature of the neutron star., Comment: 12 pages, 11 figures, accepted by MNRAS

Recently, many firms in various industries implement corporate social responsibility (CSR) in different ways. Based on considering a CSR-concerned retailer and an altruistic fairness concern manufacturer, this paper investigates pricing decisions as well as carbon emission policies in a socially responsible supply chain. In this paper, two different modes (the centralized model and decentralized model) are, respectively, conducted and investigated for equilibria. Analytical results reveal that socially responsible retailer (manufacturer) cares more about CSR (altruistic fairness) concern and will increase his counterpart’s pure profit as well as the pure channel profit, ending up with decreasing his own pure profit. The cooperative agents in decentralized scenario can coordinate the channel and achieve the maximum pure channel profit as much as that in a pure profit-maximizing centralized model. Moreover, this paper proposes a novel two-stage carbon cap-and-trade policy for the government and examines how it is affected by the CSR concern level and the altruistic fairness in such a socially responsible supply chain.

We used two XMM-Newton and six Neutron Star Interior Composition Explorer (NICER) observations to investigate the fractional rms amplitude of the millihertz quasi-periodic oscillations (mHz QPOs) in the neutron-star low-mass X-ray binary 4U 1636-53. We studied, for the first time, the fractional rms amplitude of the mHz QPOs vs. energy in 4U 1636-53 down to 0.2 keV. We find that, as the energy increases from 0.2 keV to 3 keV, the rms amplitude of the mHz QPOs increases, different from the decreasing trend that has been previously observed above 3 keV. This finding has not yet been predicted by any current theoretical model, however, it provides an important observational feature to speculate whether a newly discovered mHz oscillation originates from the marginally stable nuclear burning process on the neutron star surface., Instituto Argentino de Radioastronomía, Facultad de Ciencias Astronómicas y Geofísicas

Objective: To investigate the mid-and long-term clinical effects of tricuspid valvuloplasty with the implantation of an artificial plastic ring. Methods: Data of 677 patients who had functional tricuspid regurgitation and left cardiac valve disease and underwent tricuspid valvuloplasty and left cardiac valve surgery were retrospectively. Among these patients, 353 underwent simple suture annuloplasty (group A) while the rest 324 patients underwent artificial plastic ring annuloplasty (group B). The two-year and more-than-two-year clinical and ultrasonocardiograph (UCG) follow-up data of the two groups were obtained and compared. Results: A total of 600 patients (88.6%) completed the long-term follow-up (more than two years). The two-year follow-up showed no significant difference in the incidence of mild tricuspid regurgitation between the two groups (82.2% vs. 92.7%, P=0.37). However, there were significantly more cases that developed into moderate to severe tricuspid regurgitation in group A than in group B (17.8% vs. 7.3%, P=0.031). The long-term follow-up revealed that the recurrence rate of tricuspid regurgitation in group B was significantly lower than that in group A (11.0% vs. 25.0%, P=0.029), and the ratio of cases developing into moderate to severe tricuspid regurgitation in group A was significantly higher than that in group B (28.9% vs. 9.9%, P=0.007). The comparison between the two intra-group time segments showed that the development of tricuspid regurgitation in group A was significantly increased (28.9% vs. 17.8%, P=0.022), but in group B it was relatively stable (9.9% vs. 7.3%, P=0.52). Conclusions: Artificial ring annuloplasty is associated with significantly less tricuspid regurgitation than simple suture annuloplasty.

Recently, microgrids are increasingly used in our lives. The purpose of this paper is to solve the uncertainties of multi-objective decision-making and the instability of algorithms in the optimal configuration of traditional microgrids. This paper proposed a differential evolution algorithm based on PCA to determine the objective function. Firstly, a multi-objective optimization model of the micro-grid was established on the basis of fully considering the economy, environmental protection and stability of the micro-grid. Next, the first principal component of the multi-objective was extracted based on PCA combining innovatively the Pareto optimal solution set, and the multi-objective optimization problem was transformed into a single-objective optimization problem. Finally, the experimental simulation result shows that the algorithm proposed in this paper can comprehensively consider the economy, environmental protection and stability of the microgrid on the basis of ensuring the efficiency and stability of the algorithm to realize the optimized configuration of the microgrid.

This paper studies the asymptotic stability for a class of neutral systems with mixed time-varying delays. Through utilizing some Wirtinger-based integral inequalities and extending the convex combination technique, the upper bound on derivative of Lyapunov-Krasovskii (L-K) functional can be estimated more tightly and three mixed-delay-dependent criteria are proposed in terms of linear matrix inequalities (LMIs), in which the nonlinearity and parameter uncertainties are also involved, respectively. Different from those existent works, based on the interconnected relationship between neutral delay and state one, some novel triple integral functional terms are constructed and the conservatism can be effectively reduced. Finally, two numerical examples are given to show the benefits of the proposed criteria.

The robust stability in a class of uncertain linear neutral systems with time-varying delays is studied. Through choosing multiple integral Lyapunov terms and using some novel integral inequalities, a much tighter estimation on derivative of Lyapunov–Krasovskii (L–K) functional is presented and two stability criteria are expressed in terms of linear matrix inequalities, in which those previously ignored information can be considered. In particular, the proposed Lyapunov technique can effectively consider the interconnection between neutral delay and state one. Finally, two numerical examples with comparing results can show the application area and benefits of the proposed conditions.

We investigate the relation between the parameters of the energy spectrum and the frequency and amplitude of the kilohertz quasi-periodic oscillations (kHz QPOs) in the low-mass X-ray binary 4U 1636$-$53. We fit the $3-180$-keV spectrum of this source with a model that includes a thermal Comptonisation component. We show that the frequencies of both kHz QPOs follow the same relation as a function of the parameters of this spectral component, except for a systematic frequency shift, whereas the rms fractional amplitude of each QPO follows a different relation with respect to those same parameters. This implies that, while the dynamical mechanism that sets the frequencies of the QPO can be the same for both kHz QPOs, the radiative mechanisms that set the amplitudes of the lower and the upper kHz QPO are likely different. We discuss the implications of these results to the modelling of the kHz QPOs and the possibility that the lower kHz QPO reflects a resonance between the Comptonising medium and the photons from the accretion disc and/or the neutron star surface., Comment: 7 pages, 4 figures, 2 tables. Accepted for publication in MNRAS

We investigate the frequency and amplitude of the millihertz quasi-periodic oscillations (mHz QPOs) in the neutron-star low-mass X-ray binary (NS LMXB) 4U 1636-53 using Rossi X-ray Timing Explorer observations. We find that no mHz QPOs appear when the source is in the hard spectral state. We also find that there is no significant correlation between the frequency and the fractional rms amplitude of the mHz QPOs. Notwithstanding, for the first time, we find that the absolute RMS amplitude of the mHz QPOs is insensitive to the parameter Sa, which measures the position of the source in the colour-colour diagram and is usually assumed to be an increasing function of mass accretion rate. This finding indicates that the transition from marginally stable burning to stable burning or unstable burning could happen very rapidly since, before the transition, the mHz QPOs do not gradually decay as the rate further changes., Comment: Accepted for publication in ApJ, 9 pages, 8 figures

We present the first release of the data and compact-source catalogue for the JCMT Large Program SCUBA-2 Continuum Observations of Pre-protostellar Evolution (SCOPE). SCOPE consists of 850-um continuum observations of 1235 Planck Galactic Cold Clumps (PGCCs) made with the Submillimetre Common-User Bolometer Array 2 on the James Clerk Maxwell Telescope. These data are at an angular resolution of 14.4 arcsec, significantly improving upon the 353-GHz resolution of Planck at 5 arcmin, and allowing for a catalogue of 3528 compact sources in 558 PGCCs. We find that the detected PGCCs have significant sub-structure, with 61 per cent of detected PGCCs having 3 or more compact sources, with filamentary structure also prevalent within the sample. A detection rate of 45 per cent is found across the survey, which is 95 per cent complete to Planck column densities of $N_{H_{2}}$ $>$ 5 $\times$ 10$^{21}$ cm$^{-2}$. By positionally associating the SCOPE compact sources with YSOs, the star formation efficiency, as measured by the ratio of luminosity to mass, in nearby clouds is found to be similar to that in the more distant Galactic Plane, with the column density distributions also indistinguishable from each other., 16 pages, 13 figures, 1 table. Accepted for publication in MNRAS

We present optical, UV and X-ray monitoring of the short orbital period black hole X-ray binary candidate Swift J1753.5-0127, focusing on the final stages of its 12$-$year long outburst that started in 2005. From September 2016 onward, the source started to fade and within three months, the optical flux almost reached the quiescent level. Soon after that, using a new proposed rebrightening classification method we recorded a mini-outburst and a reflare in the optical light curves, peaking in February (V$\rm\sim$17.0) and May (V$\rm\sim$17.9) 2017, respectively. Remarkably, the mini-outburst has a peak flux consistent with the extrapolation of the slow decay before the fading phase preceding it. The following reflare was fainter and shorter. We found from optical colors that the temperature of the outer disk was $\sim 11$,000 K when the source started to fade rapidly. According to the disk instability model, this is close to the critical temperature when a cooling wave is expected to form in the disk, shutting down the outburst. The optical color could be a useful tool to predict decay rates in some X-ray transients. We notice that all X-ray binaries that show mini-outbursts following a main outburst are short orbital period systems ($, Comment: 12 pages, 4 figures, accepted for publication in ApJ

In this White Paper we present the potential of the Enhanced X-ray Timing and Polarimetry (eXTP) mission for determining the nature of dense matter; neutron star cores host an extreme density regime which cannot be replicated in a terrestrial laboratory. The tightest statistical constraints on the dense matter equation of state will come from pulse profile modelling of accretion-powered pulsars, burst oscillation sources, and rotation-powered pulsars. Additional constraints will derive from spin measurements, burst spectra, and properties of the accretion flows in the vicinity of the neutron star. Under development by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Science, the eXTP mission is expected to be launched in the mid 2020s., Comment: Accepted for publication on Sci. China Phys. Mech. Astron. (2019)

In order to enhance the stable operation of the multi-energy complementary microgrid for wind, solar, and diesel storage, reduce operating costs, and solve the problems of large randomness, low accuracy, and slow convergence of traditional microgrid optimization multi-objective decision-making, a differential evolution based on the entropy weight method to determine the weight is proposed. Firstly, we establish a microgrid integrated energy model from the perspectives of system operation stability, economy and environmental protection; combined with the Pareto optimal solution set, multi-objectives are weighted according to the entropy weight method, and the multi-objective optimization problem is transformed into single-objective optimization The problem is to avoid artificial setting of weight factors; the calculation example shows that this method is more economical and reasonable in optimization results, and provides an economic, reliable and environmentally friendly microgrid configuration strategy for users to increase power capacity.

During indoor mobile mapping, localization plays an important role. It is difficult for IMU, odometer, Lidar or SLAM algorithm singly to meet the high efficiency, real-time, accurate and robust performance. So the fusion of the data measured by these different methods is a current research hotspot. However, most of the researches still focus on the loosely coupled fusion based on filtering methods, and the data cannot be fully utilized. In this paper, based on LOM-SAM framework, the Intensity Scan Context is introduced to extract keyframes and detect loop closure which will provide a closed-loop factor, together with IMU pre-integration factor and Lidar odometry factor to construct the factor graph. Then incremental smoothing optimization algorithm is used to get high precision trajectory, realize the tightly-coupled Lidar and IMU positioning. The results show that the number of keyframes is reduced, the elevation error is effectively decreased, and the real-time performance is improved without decreasing the accuracy of LIO-SAM.

To predict the boiler’s combustion efficiency and NOx emissions, this paper introduced a particle swarm optimization optimized XGBoost algorithm. The results show that the MAPE can reach 0.107% and 3.732% respectively on the verification set, which is better SVM, LR and ANN. At the same time, this paper presents a comprehensive benefits evaluation function considering economic and environmental benefits to optimize the multi-objective optimization problem of boiler’s combustion efficiency and NOx emission. Based on the operation data of a 300 MW Circulating Fluidized Bed, the experimental results show that: the comprehensive benefits evaluation function can reasonably balance boiler’s combustion efficiency and NOx emissions to achieve the optimal comprehensive benefit.

In this paper, the problem of event-triggered output synchronization is investigated in a class of master-slave Lur'e systems with heterogeneous dimensions. By designing an improved event-triggered strategy via sampled-data transmission, a novel stability criterion on the error system is formulated and the synchronization ones are presented in terms of linear matrix inequalities (LMIs). In particular, the proposed results can be easily checked and the controller gains can be achieved by solving the derived LMIs. Furthermore, the previously neglected information can be fully considered and the conservatism can be efficiently reduced. Finally, two numerical examples are given to illustrate the efficiency of the presented results.

While there are many dynamical mechanisms and models that try to explain the origin and phenomenology of the quasi-periodic oscillations (QPOs) seen in the X-ray light curves of low-mass X-ray binaries, few of them address how the radiative processes occurring in these extreme environments give rise to the rich set of variability features actually observed in these light curves. A step towards this end comes from the study of the energy and frequency dependence of the phase lags of these QPOs. Here we used a methodology that allowed us to study, for the first time, the dependence of the phase lags of all QPOs in the range of 1 Hz to 1300 Hz detected in the low-mass X-ray binary 4U 1636-53 upon energy and frequency as the source changes its states as it moves through the colour-colour diagram. Our results suggest that within the context of models of up-scattering Comptonization, the phase lags dependencies upon frequency and energy can be used to extract size scales and physical conditions of the medium that produces the lags.

Using hydroxyl radicals as an in vitro antioxidant model and using ascorbic acid (Vc) as a positive control, four important marine activities of trehalose, carboxymethyl chitosan, glucosamine hydrochloride, and rippled paphia small molecule peptide were studied Antioxidant ability of the substance in vitro. The experimental results show that the four marine active substances have good antioxidant properties, and their antioxidant properties show a certain positive correlation with the concentration; carboxymethyl chitosan has a stronger ability to eliminate hydroxyl radicals than the other three marine active substances. When the concentration was 4 g/L, the elimination rate of para-hydroxyl radicals reached 91.71%.

More than one hundred galaxy-scale strong gravitational lens systems have been found by searching for the emission lines coming from galaxies with redshifts higher than the lens galaxies. Based on this spectroscopic-selection method, we introduce the deep Residual Networks (ResNet, a kind of deep Convolutional Neural Networks) to search for the galaxy-Ly$\alpha$ emitter (LAE) lens candidates by recognizing the Ly$\alpha$ emission lines coming from high redshift galaxies ($2 < z < 3$) in the spectra of early-type galaxies (ETGs) at middle redshift ($z\sim 0.5$). The spectra of the ETGs come from the Data Release 12 (DR12) of the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey \uppercase\expandafter{\romannumeral3} (SDSS-\uppercase\expandafter{\romannumeral3}). In this paper, we first build a 28 layers ResNet model, and then artificially synthesize 150,000 training spectra, including 140,000 spectra without Ly$\alpha$ lines and 10,000 ones with Ly$\alpha$ lines, to train the networks. After 20 training epochs, we obtain a near-perfect test accuracy at 0.9954. The corresponding loss is 0.0028 and the completeness is 93.6\%. We finally apply our ResNet model to our predictive data with 174 known lens candidates. We obtain 1232 hits including 161 of the 174 known candidates (92.5\% discovery rate). Apart from the hits found in other works, our ResNet model also find 536 new hits. We then perform several subsequent selections on these 536 hits and present 5 most believable lens candidates., Comment: 9 pages, 7 figures, 1 table, Accepted by MNRAS

Disc instability models predict that for X-ray binaries in quiescence, there should be a brightening of the optical flux prior to an X-ray outburst. Tracking the X-ray variations of X-ray binaries in quiescence is generally not possible, so optical monitoring provides the best means to measure the mass accretion rate variability between outbursts, and to identify the beginning stages of new outbursts. With our regular Faulkes Telescope/Las Cumbres Observatory (LCO) monitoring we are routinely detecting the optical rise of new X-ray binary outbursts before they are detected by X-ray all-sky monitors. We present examples of detections of an optical rise in X-ray binaries prior to X-ray detection. We also present initial optical monitoring of the new black hole transient MAXI J1820+070 (ASASSN-18ey) with the Faulkes, LCO telescopes and Al Sadeem Observatory in Abu Dhabi, UAE. Finally, we introduce our new real-time data analysis pipeline, the 'X-ray Binary New Early Warning System (XB-NEWS)' which aims to detect and announce new X-ray binary outbursts within a day of first optical detection. This will allow us to trigger X-ray and multi-wavelength campaigns during the very early stages of outbursts, to constrain the outburst triggering mechanism., Comment: Accepted to Astronomische Nachrichten/Astronomical Notes (proceedings of XMM-Newton workshop 'Time-Domain Astronomy: A High Energy View', ESAC, Madrid, Spain, 13-15 June 2018)

We present the X-ray timing results of the new black hole candidate (BHC) MAXI J1535-571 during its 2017 outburst from Hard X-ray Modulation Telescope (\emph{Insight}-HXMT) observations taken from 2017 September 6 to 23. Following the definitions given by \citet{Belloni2010}, we find that the source exhibits state transitions from Low/Hard state (LHS) to Hard Intermediate state (HIMS) and eventually to Soft Intermediate state (SIMS). Quasi-periodic oscillations (QPOs) are found in the intermediate states, which suggest different types of QPOs. With the large effective area of \emph{Insight}-HXMT at high energies, we are able to present the energy dependence of the QPO amplitude and centroid frequency up to 100 keV which is rarely explored by previous satellites. We also find that the phase lag at the type-C QPOs centroid frequency is negative (soft lags) and strongly correlated with the centroid frequency. By assuming a geometrical origin of type-C QPOs, the source is consistent with being a high inclination system., Comment: 12 pages, 11 figures, Sumbitted to ApJ

This paper is concerned with designing delay feedback controllers of master---slave synchronization for Lur'e systems. Through dividing the delay interval into two parts and choosing two augmented Lyapunov---Krasovskii functionals, some delay-dependent synchronization criteria are formulated in terms of linear matrix inequalities (LMIs), in which the conservatism can be effectively reduced based on adjusting some useful parameters. The proposed conditions can be easily checked, and the controller gains can be achieved by solving the derived LMIs. Finally, two numerical examples are given to illustrate the presented results.

The candidate black hole X-ray binary Swift J1753.5-0127 faded to quiescence in 2016 November, after a prolonged outburst that was discovered in 2005. Nearly three months later the system displayed renewed activity that lasted through 2017 July. Here, we present radio and X-ray monitoring over ~3 months of the renewed activity to study the coupling between the jet and the inner regions of the disk/jet system. Our observations cover low X-ray luminosities that have not historically been well-sampled (Lx~2e33 - 1e36 erg/s; 1-10 keV), including time periods when the system was both brightening and fading. At these low luminosities Swift J1753.5-0127 occupies a parameter space in the radio/X-ray luminosity plane that is comparable to "canonical" systems (e.g., GX 339-4), regardless of whether the system was brightening or fading, even though during its >11-year outburst Swift J1753.5-0127 emitted less radio emission from its jet than expected. We discuss implications for the existence of a single radio/X-ray luminosity correlation for black hole X-ray binaries at the lowest luminosities (Lx < 1e35 erg/s), and we compare to supermassive black holes. Our campaign includes the lowest luminosity quasi-simultaneous radio/X-ray detection to date for a black hole X-ray binary during its rise out of quiescence, thanks to early notification from optical monitoring combined with fast responses from sensitive multiwavelength facilities., 11 pages, 3 figures, 1 table. Accepted for publication in ApJ

In this paper, in order to figure out the variations before an earthquake and extract abnormal signals related to it, the geomagnetic three component Z, H, F minute values of 15 geomagnetic stations within 600[Formula: see text]km of the epicentral distance before the MS 6.6 Minxian–Zhangxian earthquake in Gansu were analyzed. The following are the results. (1) After the fractal analysis was used directly, only three geomagnetic stations in 15 geomagnetic stations showed synchronous anomalous signals; (2) After the method of this paper was used, 9 of the 15 geomagnetic stations (including the three stations in the first point) extracted two synchronous anomalous signals, and six of the nine geomagnetic stations presented additional synchronous anomalous signals. (3) Of the three abnormal signals extracted, one had a medium-term effect and two had short-term effects. (4) The anomalous duration of the Z component of nine geomagnetic stations was longer than that of H and F. And as the epicentral distance increased, duration decreased. While the proposed method could not clearly indicate the exact relationship between the anomalous signals and the earthquake, it was proved that the signals extracted are effective and well-correlative to the earthquake.

We investigated the convexity of all type I X-ray bursts with millihertz quasi-periodic oscillations (mHz QPOs) in 4U 1636-53 using archival observations with the Rossi X-ray Timing Explorer. We found that, at a 3.5 $\sigma$ confidence level, in all 39 cases in which the mHz QPOs disappeared at the time of an X-ray burst, the convexity of the burst is positive. The convexity measures the shape of the rising part of the burst light curve and, according to recent models, it is related to the ignition site of bursts on the neutron star surface. This finding suggests that in 4U 1636-53 these 39 bursts and the marginally-stable nuclear burning process responsible for the mHz QPOs take place at the neutron-star equator. This scenario could explain the inconsistency between the high accretion rate required for triggering mHz QPOs in theoretical models and the relatively low accretion rate derived from observations., Comment: Accepted for publication in MNRAS; 12 pages, 3 figures

Blockade of aberrant Wnt signaling is an attractive therapeutic approach in multiple cancers. We developed and performed a cellular high-throughput screen for inhibitors of Wnt secretion and pathway activation. A lead structure (GNF-1331) was identified from the screen. Further studies identified the molecular target of GNF-1331 as Porcupine, a membrane bound O-acyl transferase. Structure–activity relationship studies led to the discovery of a novel series of potent and selective Porcupine inhibitors. Compound 19, GNF-6231, demonstrated excellent pathway inhibition and induced robust antitumor efficacy in a mouse MMTV-WNT1 xenograft tumor model.

Recently, the neutron star X-ray binary EXO 0748-676 underwent a transition to quiescence. We analyzed an XMM-Newton observation of this source in quiescence, where we fitted the spectrum with two different neutron-star atmosphere models. From the fits we constrained the allowed parameter space in the mass-radius diagram for this source for an assumed range of distances to the system. Comparing the results with different neutron-star equations of state, we constrained the distance to EXO 0748-676. We found that the EOS model 'SQM1' is rejected by the atmosphere model fits for the known distance, and the 'AP3' and 'MS1' is fully consistent with the known distance.

Time-resolved spectra during the cooling phase of thermonuclear X-ray bursts in low-mass X-ray binaries (LMXBs) can be used to measure the radii and masses of neutron stars. We analyzed ~ 300 bursts of the LMXB 4U 1636-53 using data from the Rossi X-ray Timing Explorer. We divided the bursts in three groups, photospheric radius expansion (PRE), hard non-PRE and soft non-PRE bursts, based on the properties of the bursts and the state of the source at the time of the burst. For the three types of bursts, we found that the average relation between the bolometric flux and the temperature during the cooling phase of the bursts is significantly different from the canonical $F \propto T^4$ relation that is expected if the apparent emitting area on the surface of the neutron star remains constant as the flux decreases during the decay of the bursts. We also found that a single power law cannot fit the average flux-temperature relation for any of the three types of bursts, and that the flux-temperature relation for the three types of bursts is significantly different. Finally, for the three types of bursts, the temperature distribution at different flux levels during the decay of the bursts is significantly different. From the above we conclude that hard non-PRE bursts ignite in a hydrogen-rich atmosphere, whereas for soft non-PRE and PRE bursts the fuel is helium-rich. We further conclude that the metal abundance in the neutron star atmosphere decreases as the bursts decay, probably because the heavy elements sink faster in the atmosphere than H and He.