Abstract The screening-current effect is an inhomogeneous distribution of current density inside the REBCO conductors. The additional strain induced by the screening current, known as ...screening-current induced strain (SCS), is considered to affect the structural integrity of REBCO windings, especially when operating high-field REBCO insert magnets. In this work, we wound and tested a series of 50-turn REBCO coils inside a 10 T LTS external to investigate the influencing mechanism of multiple electromagnetic factors on SCS. We varied the critical current in different coils by different heat treatment procedures. Each coil was tested individually, experiencing a external field cycle and multiple operation current cycles at constant external fields. The extreme scenario for each coil was being energized to 400 A while the external field was 10 T. We adapted the discrete-coupled model to estimate the hoop strain distribution, monitored the experimental results by multiple strain gauges at the outermost turn. Test coil with a lower critical current endured a lower maximum hoop strain. When we were energizing the test coils, hoop strain increased at the edge of REBCO tapes while remaining nearly constant in the middle region. Additionally, the maximum hoop strain at the outermost turn decreased after each excitation cycle. This work could be an experimental reference for optimizing the electromagnetic design and the excitation scheme during the development of high-field REBCO magnets.
Geodesy Gu, Jianzhe; Breen, David E.; Hu, Jenny ...
Proceedings of the 2019 CHI Conference on Human Factors in Computing Systems,
05/2019
Conference Proceeding
Thermoplastic and Fused Deposition Modeling (FDM) based 4D printing are rapidly expanding to allow for space- and material-saving 2D printed sheets morphing into 3D shapes when heated. However, to ...our knowledge, all the known examples are either origami-based models with obvious folding hinges, or beam-based models with holes on the morphing surfaces. Morphing continuous double-curvature surfaces remains a challenge, both in terms of a tailored toolpath-planning strategy and a computational model that simulates it. Additionally, neither approach takes surface texture as a design parameter in its computational pipeline. To extend the design space of FDM-based 4D printing, in Geodesy, we focus on the morphing of continuous double-curvature surfaces or surface textures. We suggest a unique tool path - printing thermoplastics along 2D closed geodesic paths to form a surface with one raised continuous double-curvature tiles when exposed to heat. The design space is further extended to more complex geometries composed of a network of rising tiles (i.e., surface textures). Both design components and the computational pipeline are explained in the paper, followed by several printed geometric examples.
This article employs the number of news appeared in Baidu News as a novel proxy for information arrival and investigates the validation of the Mixture of Distribution Hypothesis (MDH) using a sample ...of SME PRICE INDEX in China. The empirical results reveal a positive impact of internet information on the conditional volatility of stock returns. Compared with the prevailing proxies (trading volume and its adjustments), the volatility persistence is most decreased when this novel proxy is incorporated into the conditional variance equation of the GARCH model. Some tentative explanations are also given to expound the non-disappeared GARCH effects.
•We employ Baidu News as a proxy for information arrival.•A positive impact of internet information on volatility is found.•Internet information is a better proxy for information arrival.
Which kind of investor causes comovement? Li, Jie; Zhang, Yongjie; Feng, Xu ...
Journal of international financial markets, institutions & money,
07/2019, Letnik:
61
Journal Article
Recenzirano
•The flow of fund is the main generator of return comovement.•Other investors have no impacts on the return comovement.•Comovement arising from fund flow is due to the purchase and ...redemption.•Purchases cause more comovement than redemptions do.
In this study, we examine whether the trading behavior of different types of investors (individual investors, funds, qualified foreign institutional investors, insurance, and state-owned companies) generate different effects on excess return comovement. The empirical results show that only funds’ behavior forecasts more variation in excess return correlation, controlling for the other three types of factors (macroeconomic, stock characteristics, and information diffusion). Moreover, we provide adequate evidence that the comovement arising from funds’ trading behavior is due to their specific purchase and redemption mechanism, rather than holding more or trading more. Finally, an additional test is conducted to confirm that purchases cause more comovement than redemptions do, which might be related to larger amount of purchases.
Objective. In this study, α-Gal epitope-deficient (GGTA1 knockout (GTKO)) mice were used to assess the immunological risks of xenogeneic dural patch by comparing with raw material. Methods. The ...xenogeneic dural patch (T2) was prepared from bovine pericardium (T1, raw material) through decellularization and carboxymethyl chitosan (CMCS) coating. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to characterize the collagen fibers and surface microstructural changes in the T1 and T2 samples. The remnant α-Gal epitopes and DNA of implants were detected by standardized method. T1 and T2 were implanted subcutaneously into GTKO mice for 4 and 12 weeks, respectively, and the negative control group (Con) was only performed sham operation. The total serum antibody, anti-Gal antibody, and splenic lymphocyte subtypes were analyzed by ELISA or flow cytometry, and histological analysis of implant-tissue was performed by H&E and Masson stain. Results. TEM and Sirius red staining showed that the collagen fibers in the dural patch were closely arranged, and SEM showed that a loose three-dimensional structure was successfully constructed on the surface of the dural patch after CMCS coating. The remnant DNA in T2 was 24.64±8.73 ng/mg (dry weight), and clearance of α-Gal epitope was up to 99.83% compared to T1. The significant increases in serum total IgM, anti-Gal IgG, and anti-Gal IgM at 4 weeks and the significant changes in anti-Gal IgG and spleen lymphocyte at 12 weeks were observed in the T1 group, but no significant change was observed in the T2 group, compared to the control group. Histological semiquantitative analysis showed severe cell and tissue responses at 4 weeks and a moderate response at 12 weeks in the T1 group, while a moderate response at 4 weeks and a slight response at 12 weeks in the T2 group. Conclusions. The results demonstrated that the xenogeneic dural patch has a lower and acceptable immunological risk compared to the raw material and control, respectively. On the other hand, it was suggested that GTKO mice are useful experimental model for immunological risk assessment of animal tissue-derived biomaterials.
A novel amphiphilic B,O-chelated azadipyrromethene (aza-BODIPY) dye, containing hydrophobic dodecyloxy groups and hydrophilic tetraethylene glycol (TEG) chains, was synthesized and characterized by ...NMR, HRMS, Vis/NIR absorption and fluorescence spectroscopy. The B,O-chelated dye 1 exhibited largely bathochromically shifted NIR absorption and fluorescence spectra in comparison with common BF2-chelated aza-BODIPY dyes. Upon gradual addition of trifluoroacetic acid (TFA) to the dye 1 solution, obvious spectral changes were observed in Vis/NIR absorption and fluorescence spectroscopy measurements. Meanwhile, the colour change of the dye 1 solution from pink to blue was noticeable by the naked eye, indicating the pH-sensitivity of dye 1. The pH-sensitivity of dye 1 under acidic conditions could be ascribed to the formation of dye species 2·H+. Furthermore, owing to the amphiphilic feature of dye 1, it self-assembled into J-type aggregates in a mixed solvent of water/DMSO (2/8, v/v). Temperature-dependent Vis/NIR spectroscopic studies revealed a cooperative aggregation process of dye 1 and a nanowire-like morphology of the nanoaggregates was observed by AFM.
A novel cationic surfactant Guerbet-cetyl trimethyl ammonium chloride (G-CTAC) was synthesized by combining several traditional synthetic processes in laboratory. The molecular structure of G-CTAC ...was characterized by Fourier transform infrared (FT-IR) spectra and proton nuclear magnetic resonance (
1
HNMR). This new amphiphile exhibited excellent performances in aqueous solution, which was investigated by surface tension measurement, contact angle on parafilm, particle size of aggregates, transmission electron microscopy (TEM), emulsifying experiments, and antistatic tests. It was found that the new quaternary ammonium compound could effectively decrease the surface tension of aqueous solution to 26.2 mN m
−1
with the critical micelle concentration (CMC) being 5.9 mmol L
−1
. In addition, the cationic surfactant synthesized could efficiently decrease the contact angle of aqueous solution on paraffin surface. We suppose that these unique properties are attributed to the presence of the branching Guerbet-cetyl being hydrophobic group in the molecule. Moreover, according to TEM observations, this quaternary ammonium compound was inclined to aggregate into vesicles spontaneously without induction of any other additives in aqueous solution. Antistatic tests and emulsifying experiments were also conducted to explore the potential applications of this new material.
The effect of fertilizer N on maize (Zea mays L.) root size has been reported with inconsistency. It remains unclear whether a quantitative relationship exists between soil NO3–N and root growth ...under field conditions. A 3‐yr field experiment was conducted in three soils (loamy clay, clay loam, and sandy loam) with five N treatments (from 0–312 kg N ha−1). Soil NO3–N concentration and total root length were determined to a depth of 60 cm at the silking stage. It was found that plants grown in clay loam soil had larger root size compared with the other two soil. A weak parabolic relationship between N supply and root length was found in loamy clay and clay loam soil, but not in sandy loam soil. There was a parabolic relationship between soil NO3–N concentration in the 0‐ to 60‐cm depth and total root length per plant. This relationship was mostly found in clay loam soil. Across soils and years, there was a parabolic relationship between root length density (RLD) and shoot dry matter (DM) at silking and between RLD at silking and grain yield with fertilizer N rate £240 kg N ha−1. It is suggested that it may be not practical to regulate total root length by simply adjusting N fertilizer amount. Total root length is not relevant to maize yield under excess N input conditions.
Core Ideas
Plants grown in clay loam soil had larger root than in loamy clay and sandy loam soils.
A parabolic relationship between soil nitrate‐N concentration and total root length.
A weak parabola relationship between N supply and root length was found in loamy clay soil and clay loam soil, but not in sandy loam soil. Root length and the maximum yield reached synchronously at optimum N rates (168–240 kg N ha−1 in the present study).
The objective of this paper is to examine the possible linkage between the intraday stock price crashes and jumps and public information by using data from the Chinese stock market and Baidu Index. ...We divided public information into two kinds of information: supply through online media and information demand across inquiries by individual investors. Using a large sample from Chinese listed firms from 2013 to 2019, our evidence clearly indicates that online information supply and demand both have a positive impact on the intraday crashes and jumps; this is, the firm with higher information supply and demand more likely to experience intraday crashes and jumps. The results are robust to an alternative measure of crash risk. Moreover, we further examine whether the market conditions have an impact on the relationship between information flow and intraday crashes and jumps, and find that the marginal effect of information supply on intraday price crashes and jumps is smaller in the bull market phase. Moreover, the bull market phase enhances the effect of information demand on intraday price crashes and jumps.
This paper describes an automatic and efficient approach to construct unstructured tetrahedral and hexahedral meshes for a composite domain made up of heterogeneous materials. The boundaries of these ...material regions form non-manifold surfaces. In earlier papers, we developed an octree-based isocontouring method to construct unstructured 3D meshes for a single material (homogeneous) domain with manifold boundary. In this paper, we introduce the notion of a
material change edge and use it to identify the interface between two or several different materials. A novel method to calculate the minimizer point for a cell shared by more than two materials is provided, which forms a non-manifold node on the boundary. We then mesh all the material regions simultaneously and automatically while conforming to their boundaries directly from volumetric data. Both material change edges and interior edges are analyzed to construct tetrahedral meshes, and interior grid points are analyzed for proper hexahedral mesh construction. Finally, edge-contraction and smoothing methods are used to improve the quality of tetrahedral meshes, and a combination of pillowing, geometric flow and optimization techniques is used for hexahedral mesh quality improvement. The shrink set of pillowing schemes is defined automatically as the boundary of each material region. Several application results of our multi-material mesh generation method are also provided.
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