Combining Context and Knowledge Representations for Chemical-Disease Relation Extraction

Automatically extracting the relationships between chemicals and diseases is significantly important to various areas of biomedical research and health care. Biomedical experts have built many large-scale knowledge bases (KBs) to advance the development of biomedical research. KBs contain huge amounts of structured information about entities and relationships, therefore plays a pivotal role in chemical-disease relation (CDR) extraction. However, previous researches pay less attention to the prior knowledge existing in KBs. This paper proposes a neural network-based attention model (NAM) for CDR extraction, which makes full use of context information in documents and prior knowledge in KBs. For a pair of entities in a document, an attention mechanism is employed to select important context words with respect to the relation representations learned from KBs. Experiments on the BioCreative V CDR dataset show that combining context and knowledge representations through the attention mechanism, could significantly improve the CDR extraction performance while achieve comparable results with state-of-the-art systems.Comment: Published on IEEE/ACM Transactions on Computational Biology and Bioinformatics, 11 pages, 5 figure

Efficient quasi-monoenergetic ion beams from laser-driven relativistic plasmas

Table-top laser-plasma ion accelerators have many exciting applications, many of which require ion beams with simultaneous narrow energy spread and high conversion efficiency. However, achieving these requirements has been elusive. Here we report the experimental demonstration of laser-driven ion beams with narrow energy spread and energies up to 18 MeV per nucleon and similar to 5% conversion efficiency (that is 4 J out of 80-J laser). Using computer simulations we identify a self-organizing scheme that reduces the ion energy spread after the laser exits the plasma through persisting self-generated plasma electric (similar to 10(12) V m(-1)) and magnetic (similar to 10(4) T) fields. These results contribute to the development of next generation compact accelerators suitable for many applications such as isochoric heating for ion-fast ignition and producing warm dense matter for basic science

Efficient quasi-monoenergetic ion beams from laser-driven relativistic plasmas

Table-top laser-plasma ion accelerators have many exciting applications, many of which require ion beams with simultaneous narrow energy spread and high conversion efficiency. However, achieving these requirements has been elusive. Here we report the experimental demonstration of laser-driven ion beams with narrow energy spread and energies up to 18 MeV per nucleon and similar to 5% conversion efficiency (that is 4 J out of 80-J laser). Using computer simulations we identify a self-organizing scheme that reduces the ion energy spread after the laser exits the plasma through persisting self-generated plasma electric (similar to 10(12) V m(-1)) and magnetic (similar to 10(4) T) fields. These results contribute to the development of next generation compact accelerators suitable for many applications such as isochoric heating for ion-fast ignition and producing warm dense matter for basic science

Continuous spin excitations in the three-dimensional frustrated magnet K2Ni2(SO4)3

Continuous spin excitations are widely recognized as one of the hallmarks of novel spin states in quantum magnets, such as quantum spin liquids (QSLs). Here, we report the observation of such kind of excitations in K2Ni2(SO4)3, which consists of two sets of intersected spin-1 Ni2+ trillium lattices. Our inelastic neutron scattering measurement on single crystals clearly shows a dominant excitation continuum, which exhibits a distinct temperature-dependent behavior from that of spin waves, and is rooted in strong quantum spin fluctuations. Further using the self-consistent-gaussian-approximation method, we determined the fourth- and fifth-nearest neighbor exchange interactions are dominant. These two bonds together form a unique three-dimensional network of corner-sharing tetrahedra, which we name as ''hyper-trillium'' lattice. Our results provide direct evidence for the existence of QSL features in K2Ni2(SO4)3 and highlight the potential for the hyper-trillium lattice to host frustrated quantum magnetism.Comment: 6 pages and 5 figures, plus several pages of supplemental material, comments are welcom

Emittance Measurements of Trapped Electrons from a Plasma Wakefield Accelerator

Recent electron beam driven plasma wakefield accelerator experiments carried out at SLAC showed trapping of plasma electrons. These trapped electrons appeared on an energy spectrometer with smaller transverse size than the beam driving the wake. A connection is made between transverse size and emittance; due to the spectrometer's resolution, this connection allows for placing an upper limit on the trapped electron emittance. The upper limit for the lowest normalized emittance measured in the experiment is 1 mm {center_dot} mrad

Computational studies and optimization of wakefield accelerators

Laser- and particle beam-driven plasma wakefield accelerators produce accelerating fields thousands of times higher than radio-frequency accelerators, offering compactness and ultrafast bunches to extend the frontiers of high energy physics and to enable laboratory-scale radiation sources. Large-scale kinetic simulations provide essential understanding of accelerator physics to advance beam performance and stability and show and predict the physics behind recent demonstration of narrow energy spread bunches. Benchmarking between codes is establishing validity of the models used and, by testing new reduced models, is extending the reach of simulations to cover upcoming meter-scale multi-GeV experiments. This includes new models that exploit Lorentz boosted simulation frames to speed calculations. Simulations of experiments showed that recently demonstrated plasma gradient injection of electrons can be used as an injector to increase beam quality by orders of magnitude. Simulations are now also modeling accelerator stages of tens of GeV, staging of modules, and new positron sources to design next-generation experiments and to use in applications in high energy physics and light sources

Spatio-temporal evolution characteristics of cultural heritage sites and their relationship with natural and cultural environment in the northern Fujian, China

Abstract China’s northern Fujian, as one of the spatial carriers of renowned traditional Chinese cultures such as Minyue, Zhu Xi’s Neo-Confucianism, tea, and porcelain, has preserved a wealth of tangible cultural relics, showcasing a profound cultural heritage and possessing strong research value and development potential. This study employs GIS spatial statistical analysis and map visualization technology to unveil the evolutionary processes of cultural heritage sites in northern Fujian, focusing on their spatial types, forms, and densities across different historical periods. Based on this foundation, the research further delves into the intrinsic relationships between the spatial distribution characteristics of cultural heritage sites in northern Fujian during various historical periods and the local natural and cultural environment. The results indicate that: (1) the spatial distribution of cultural heritage sites in northern Fujian varies across different historical periods, with the highest concentration and quantity observed during the Ming and Qing periods. In contrast, the Qin, Han, Wei, Jin, Northern and Southern Dynasties period exhibits the lowest quantity and a more dispersed distribution. (2) Cultural heritage sites in northern Fujian are mainly distributed in the relatively flat terrain below 400 m above sea level, including middle to low-altitude mountain basins, river valleys, and low hills. In terms of distance from rivers, cultural heritage sites exhibit a clear distribution pattern along rivers, with a large number of them located within 0–6 km from the riverbanks. (3) The spatial distribution of cultural heritage sites in northern Fujian is influenced not only by macro-environmental factors such as topography, altitude, and rivers but also by micro-shaping from social and cultural elements like Minyue culture, tea and porcelain ancient road culture, Zhu Xi’s Neo-Confucianism culture, religious beliefs and customs culture, and red revolutionary culture across different historical periods. This study contributes to the establishment of a model correlating cultural heritage sites with historical periods and provides an interdisciplinary methodological framework to understand the relationship between cultural heritage sites and the geographical environment