1,741 research outputs found

    Time-resolved Measurement of Quadrupole Wakefields in Corrugated Structures

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    Corrugated structures have recently been widely used for manipulating electron beam longitudinal phase space and for producing THz radiation. Here we report on time-resolved measurements of the quadrupole wakefields in planar corrugated structures. It is shown that while the time- dependent quadrupole wakefield produced by a planar corrugated structure causes significant growth in beam transverse emittance, it can be effectively canceled with a second corrugated structure with orthogonal orientation. The strengths of the time-dependent quadrupole wakefields for various corrugated structure gaps are also measured and found to be in good agreement with theories. Our work should forward the applications of corrugated structures in many accelerator based scientific facilities

    Z+(4430)Z^+(4430) as a D1DD_1'{D}^* (D1DD_1{D}^* ) molecular state

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    We reexamine whether Z+(4430)Z^+(4430) could be a D1DD_1'-{D}^* or D1DD_1-{D}^* molecular state after considering both the pion and σ\sigma meson exchange potentials and introducing the form factor to take into account the structure effect of the interaction vertex. Our numerical analysis with Matlab package MATSLISE indicates the contribution from the sigma meson exchange is small for the D1DD_1'-{D}^* system and significant for the D1DD_1-{D}^* system. The S-wave D1DˉD_1-\bar{D}^* molecular state with only JP=0J^{P}=0^- and D1DD_1'-{D}^* molecular states with JP=0,1,2J^P=0^-,1^-,2^- may exist with reasonable parameters. One should investigate whether the broad width of D1D_1' disfavors the possible formation of molecular states in the future. The bottom analog ZBZ_B of Z+(4430)Z^+(4430) has a larger binding energy, which may be searched at Tevatron and LHC. Experimental measurement of the quantum number of Z+(4430)Z^+(4430) may help uncover its underlying structure.Comment: 13 pages, 7 tables, 7 figure

    DDˉD\bar{D} production and their interactions

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    S and P wave DDˉD\bar{D} scatterings are studied in a meson exchange model with the coupling constants obtained in the heavy quark effective theory. With the extracted P wave phase shifts and the separable potential approximation, we include the DDˉD\bar{D} rescattering effect and investigate the production process e+eDDˉe^+e^-\to D\bar{D}. We find that it is difficult to explain the anomalous line shape observed by the BES collaboration with this mechanism. Combining our model calculation and the experimental measurement, we estimate the upper limit of the nearly universal cutoff parameter to be 1.7 GeV. With this number, the upper limits of the binding energies of the S wave DDˉD\bar{D} and BBˉB\bar{B} bound states are obtained. Assuming that the S wave and P wave interactions rely on the same cutoff, our study provides a way of extracting the information about S wave molecular bound states from the P wave meson pair production.Comment: 22 pages, 14 figures, 5 tables, publication versio

    Is Z^+(4430) a loosely bound molecular state?

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    Since Z+(4430)Z^+(4430) lies very close to the threshold of DDˉ1D^\ast{\bar D}_1, we investigate whether Z+(4430)Z^+(4430) could be a loosely bound S-wave state of DDˉ1D^\ast{\bar D}_1 or DDˉ1D^\ast{\bar D}^\prime_1 with JP=0,1,2J^P=0^-, 1^-, 2^-, i.e., a molecular state arising from the one-pion-exchange potential. The potential from the crossed diagram is much larger than that from the diagonal scattering diagram. With various trial wave functions, we notice that the attraction from the one pion exchange potential alone is not strong enough to form a bound state with realistic pionic coupling constants deduced from the decay widths of D1D_1 and D1D^\prime_1.Comment: 8 pages, 4 figures, 4 tables. Typos corrected, more discussions adde

    Robot Task Planning Based on Large Language Model Representing Knowledge with Directed Graph Structures

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    Traditional robot task planning methods face challenges when dealing with highly unstructured environments and complex tasks. We propose a task planning method that combines human expertise with an LLM and have designed an LLM prompt template, Think_Net_Prompt, with stronger expressive power to represent structured professional knowledge. We further propose a method to progressively decompose tasks and generate a task tree to reduce the planning volume for each task, and we have designed a strategy to decouple robot task planning. By dividing different planning entities and separating the task from the actual machine binding process, the task planning process becomes more flexible. Research results show that our method performs well in handling specified code formats, understanding the relationship between tasks and subtasks, and extracting parameters from text descriptions. However, there are also problems such as limited complexity of task logic handling, ambiguity in the quantity of parts and the precise location of assembly. Improving the precision of task description and cognitive structure can bring certain improvements. https://github.com/NOMIzy/Think_Net_Promp

    Bibliometric analysis of post-traumatic stress disorder in forensic medicine: Research trends, hot spots, and prospects

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    BackgroundPost-traumatic stress disorder (PTSD) has various risk factors, complex pathogenesis, and diverse symptoms, and is often comorbid with other injuries and diseases, making forensic diagnosis difficult.MethodsTo explore the current research status and trends of PTSD, we used the Web of Science Core Collection databases to screen PTSD-related literature published between 2010 and 2021 and CiteSpace to perform bibliometric analysis.ResultsIn recent years, PTSD-related research has grown steadily. The countries and institutions with the most research results were the United States and England, and King’s College London and Boston University, respectively. Publications were identified from 2,821 different journals, including 13 forensic-related journals, but the journal distribution was relatively scattered and there was a lack of professional core journals. Keyword co-occurrence and clustering identified many hot topics; “rat model,” “mental health,” and “satisfaction” were the topics most likely to have a clear effect on future research. Analysis extracted nine turning points from the literature that suggested that neural network centers, the hypothalamic–pituitary–adrenal axis, and biomarkers were new research directions. It was found that COVID-19 can cause severe psychological stress and induce PTSD, but the relationship needs further study. The literature on stress response areas and biomarkers has gradually increased over time, but specific systemic neural brain circuits and biomarkers remain to be determined.ConclusionThere is a need to expand the collection of different types of biological tissue samples from patients with different backgrounds, screen PTSD biomarkers and molecular targets using multi-omics and molecular biology techniques, and establish PTSD-related molecular networks. This may promote a systematic understanding of the abnormal activation of neural circuits in patients with PTSD and help to establish a personalized, accurate, and objective forensic diagnostic standard

    High frequency of Machado-Joseph disease identified in Southeastern Chinese kindreds with spinocerebellar ataxia

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    <p>Abstract</p> <p>Background</p> <p>Machado-Joseph disease (MJD), caused by a CAG repeat expansion located in exon10 of the <it>ATXN3 </it>gene, is now regarded as one of the most common spinocerebellar ataxia (SCA) in the world. The relative frequency of MJD among SCA has previously been estimated at about 50% in the Chinese population and has been reported to be related to the frequency of large normal alleles in some populations. Taq polymerase has been used for PCR in nearly all studies reported previously.</p> <p>Methods</p> <p>Normal and expanded alleles of <it>ATXN3 </it>were detected via PCR using LA Taq DNA polymerase (better for GC-rich sequences) and denaturing polyacrylamide gel electrophoresis in 150 normal individuals and 138 unrelated probands from autosomal dominant SCA families. To compare reaction efficiency, 12 MJD patients' expanded alleles were amplified with La Taq and Taq polymerase respectively in the same amplifying systems and reaction conditions.</p> <p>Results</p> <p>Normal alleles ranged from 12 to 42 CAG repeats. The most common allele contained 14 repeats with a frequency of 23.3%, which corroborates previous reports. The frequency of large normal alleles (>27 repeats) was 0.28, which was very high relative to previous reports. The frequency of MJD in SCA patients was 72.5%, which was significantly higher than those in previous reports about the Chinese and other Asian populations. This frequency was one of the highest reported worldwide, with only Portuguese and Brazilian populations exhibiting higher proportions. All 12 expanded alleles were amplified in PCR with La Taq polymerase, whereas only 2 expanded alleles were amplified with Taq polymerase.</p> <p>Conclusion</p> <p>We have first reported the highest relative frequency of MJD in Asia, and we attribute this high frequency to a more efficient PCR using LA Taq polymerase and hypothesized that large ANs may act as a reservoir for expanded alleles in the Southeastern Chinese population.</p

    5-[(3,4-Dimethoxy­benzyl)­aminomethyl­ene]-2,2-dimethyl-1,3-dioxane-4,6-dione

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    The title compound, C15H17NO6, is approximately planar, with dihedral angles of 3.11 (4) and 2.12 (4)° between the connecting amino­methyl­ene unit and the planar part of the dioxane ring, and between the dimethoxy­benzyl ring and the amino­methyl­ene group, respectively. The dioxane ring exhibits a half-boat conformation, in which the C atom between the dioxane O atoms is 0.5471 (8) Å out of the plane. The mol­ecule has an intra­molecular N—H⋯O hydrogen bond which may stabilize the planar conformation. In the crystal, weak inter­molecular C—H⋯O hydrogen-bonding contacts, result in the formation of sheets parallel to the ab plane

    Lithospheric electrical structure across the Bangong-Nujiang Suture in northern tibet revealed by magnetotelluric

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    Competing hypotheses have been proposed to explain the subduction polarity of the Bangong-Nujiang Tethyan Ocean and the formation of the high-conductivity anomaly beneath the Qiangtang terrane. However, the lithospheric architecture of the northern Tibetan Plateau is still poorly understood due to inhospitable environments and topography. Therefore, in the winter of 2021, a 440 km long, SN-trending broadband magnetotelluric (MT) profile was recorded in northern Tibet to detect its regional lithospheric structure. The nonlinear conjugate gradients algorithm is conducted to invert the individual TM mode data. A reliable 2D electrical model was obtained by ablation processing and analysis of broadband magnetotelluric data to test the lithospheric electrical structure and dynamics between the northern Lhasa and Qiangtang terranes. The inversion results reveal the lithospheric structure at a depth of 100 km in northern Tibet, which synthesizes geological, geochemical and deep seismic reflection evidence and firmly identifies that the trace of the south-dipping conductor mainly resulted from the southward subduction of the Bangong-Nujiang Tethyan Ocean under the Lhasa terrane and the trace of the north-dipping conductor likely due to the northward subduction of the Bangong-Nujiang Tethyan Ocean under the Qiangtang terrane. In addition, the magnetotelluric profile also images a high-conductivity lithospheric-scale anticline beneath the central Qiangtang terrane, which may correspond to the upwelling of postcollisional magmatism triggered by northward subduction of the Bangong-Nujiang Tethyan Ocean under the Qiangtang terrane, aqueous fluid and/or partial melting

    Behavioral Evidence and Olfactory Reception of a Single Alarm Pheromone Component in Halyomorpha halys

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    Halyomorpha halys is a major herbivore insect in the fruit orchards of China that has become a devastating invasive pest in North America and Europe since its accidental introductions in the 1990s and 2000s, respectively. Like other hemipteran insects, H. halys releases defensive chemicals against natural enemies, including (E)-2-decenal, which is an aldehyde associated with alarm pheromones. In this study, a series of electrophysiological and behavioral tests were conducted to characterize the alarm functions of (E)-2-decenal among H. halys adults and nymphs. An antennal transcriptome was obtained from a Chinese H. halys population, and 44 odorant-binding protein (OBP) genes were annotated. Among them, five putative alarm pheromone-binding proteins were screened and were extremely consistent with their homologs from US populations. These five OBPs were later expressed in a heterologous expression system, harvested, and then challenged with (E)-2-decenal in a binding assay. All five OBPs showed high binding activities to (E)-2-decenal, which demonstrated its behavioral significance as a defensive component in H. halys, as well as being the first report of its olfactory reception. These findings will help develop behavioral-mediating tools as part of integrated pest management approaches to control this invasive pest
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