15,284 research outputs found

    Study on impact toughness of TMCP and quenched and tempered high strength steels

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    In this study, the effect of steel rolling technique, temperature, yield strength and welding heat input on the impact toughness of high-strength steels is studied. The impact toughness of five kinds of high strength steels with yield strength of 550 MPa, 690 MPa and 890 MPa are experimentally studied. The standard Charpy V-notch test is carried out and the absorbed energy AKV of the test specimens is obtained. The test results show that the impact toughness of QT550 high-strength steel is not sensitive to temperature and it also has good impact performance at low temperature. For other high strength steels, with increase of steel strength, the impact toughness is severely degraded with decreasing temperature. For the effect of rolling technique on impact toughness, the QT type high-strength steel generally follows the law that the impact toughness deteriorates with the increase of the yield strength. QT process can produce better impact resistance than TMCP process for 690 grade steel. The effect of temperature on the impact toughness of WM is intensified at high heat input. The impact toughness of the base material (BM), heat-affected zone (HAZ) and weld metal (WM) deteriorates with the rise of the yield strength. QT550 and QT690 show different impact characteristics for HAZ and WM. The former HAZ has better impact performance under high heat input while WM is better under low heat input; both HAZ and WM of QT690 show higher impact toughness under low heat input

    Dense nuclear matter equation of state from heavy-ion collisions

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    International audienceThe nuclear equation of state (EOS) is at the center of numerous theoretical and experimental efforts in nuclear physics. With advances in microscopic theories for nuclear interactions, the availability of experiments probing nuclear matter under conditions not reached before, endeavors to develop sophisticated and reliable transport simulations to interpret these experiments, and the advent of multi-messenger astronomy, the next decade will bring new opportunities for determining the nuclear matter EOS, elucidating its dependence on density, temperature, and isospin asymmetry. Among controlled terrestrial experiments, collisions of heavy nuclei at intermediate beam energies (from a few tens of MeV/nucleon to about 25 GeV/nucleon in the fixed-target frame) probe the widest ranges of baryon density and temperature, enabling studies of nuclear matter from a few tenths to about 5 times the nuclear saturation density and for temperatures from a few to well above a hundred MeV, respectively. Collisions of neutron-rich isotopes further bring the opportunity to probe effects due to the isospin asymmetry. However, capitalizing on the enormous scientific effort aimed at uncovering the dense nuclear matter EOS, both at RHIC and at FRIB as well as at other international facilities, depends on the continued development of state-of-the-art hadronic transport simulations. This white paper highlights the essential role that heavy-ion collision experiments and hadronic transport simulations play in understanding strong interactions in dense nuclear matter, with an emphasis on how these efforts can be used together with microscopic approaches and neutron star studies to uncover the nuclear EOS

    Optimization of performance of the KM2A full array using the Crab Nebula

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    International audienceThe full array of the Large High Altitude Air Shower Observatory (LHAASO) has been in operation since July 2021. For its kilometer-square array (KM2A), we have optimized the selection criteria for very high and ultra-high energy ő≥\gamma-rays, using the data collected from August 2021 to August 2022, resulting in an improvement on significance of about 15%\% compared with previous cuts. With the implementation of these new selection criteria, the angular resolution is also significantly improved by approximately 10%\% at tens of TeV. Other aspects of the full KM2A array performance, such as the pointing error are also calibrated using the Crab Nebula. The resulting energy spectrum of the Crab Nebula in the energy range of 10-1000 TeV can be well fitted by a log-parabola model, which is consistent with the previous results from LHAASO and other experiments

    Optimization of performance of the KM2A full array using the Crab Nebula

    No full text
    International audienceThe full array of the Large High Altitude Air Shower Observatory (LHAASO) has been in operation since July 2021. For its kilometer-square array (KM2A), we have optimized the selection criteria for very high and ultra-high energy ő≥\gamma-rays, using the data collected from August 2021 to August 2022, resulting in an improvement on significance of about 15%\% compared with previous cuts. With the implementation of these new selection criteria, the angular resolution is also significantly improved by approximately 10%\% at tens of TeV. Other aspects of the full KM2A array performance, such as the pointing error are also calibrated using the Crab Nebula. The resulting energy spectrum of the Crab Nebula in the energy range of 10-1000 TeV can be well fitted by a log-parabola model, which is consistent with the previous results from LHAASO and other experiments

    A sparse, triangle-shaped sensor array for damage orientation and characterization of composite structures

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    Title on author’s file: A Sparse, Triangle-shaped Sensor Array for Damage Orientation and Characterization of Composite Structures Using Support Vector Machine202306 bckwNot applicablePublished12 month

    Optimization of performance of the KM2A full array using the Crab Nebula

    No full text
    International audienceThe full array of the Large High Altitude Air Shower Observatory (LHAASO) has been in operation since July 2021. For its kilometer-square array (KM2A), we have optimized the selection criteria for very high and ultra-high energy ő≥\gamma-rays, using the data collected from August 2021 to August 2022, resulting in an improvement on significance of about 15%\% compared with previous cuts. With the implementation of these new selection criteria, the angular resolution is also significantly improved by approximately 10%\% at tens of TeV. Other aspects of the full KM2A array performance, such as the pointing error are also calibrated using the Crab Nebula. The resulting energy spectrum of the Crab Nebula in the energy range of 10-1000 TeV can be well fitted by a log-parabola model, which is consistent with the previous results from LHAASO and other experiments

    Detecting somatisation disorder via speech: introducing the Shenzhen Somatisation Speech Corpus

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    Objective Speech recognition technology is widely used as a mature technical approach in many fields. In the study of depression recognition, speech signals are commonly used due to their convenience and ease of acquisition. Though speech recognition is popular in the research field of depression recognition, it has been little studied in somatisation disorder recognition. The reason for this is the lack of a publicly accessible database of relevant speech and benchmark studies. To this end, we introduce our somatisation disorder speech database and give benchmark results. Methods By collecting speech samples of somatisation disorder patients, in cooperation with the Shenzhen University General Hospital, we introduce our somatisation disorder speech database, the Shenzhen Somatisation Speech Corpus (SSSC). Moreover, a benchmark for SSSC using classic acoustic features and a machine learning model is proposed in our work. Results To obtain a more scientific benchmark, we have compared and analysed the performance of different acoustic features, i. e., the full ComParE feature set, or only MFCCs, fundamental frequency (F0), and frequency and bandwidth of the formants (F1-F3). By comparison. the best result of our benchmark is the 76.0 % unweighted average recall achieved by a support vector machine with formants F1‚ÄďF3. Conclusion The proposal of SSSC bridges a research gap in somatisation disorder, providing researchers with a publicly accessible speech database. In addition, the results of the benchmark show the scientific validity and feasibility of computer audition for speech recognition in somatization disorders

    Shared and distinct genetic etiologies for different types of clonal hematopoiesis

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    Abstract Clonal hematopoiesis (CH)‚ÄĒage-related expansion of mutated hematopoietic clones‚ÄĒcan differ in frequency and cellular fitness by CH type (e.g., mutations in driver genes (CHIP), gains/losses and copy-neutral loss of chromosomal segments (mCAs), and loss of sex chromosomes). Co-occurring CH raises questions as to their origin, selection, and impact. We integrate sequence and genotype array data in up to 482,378 UK Biobank participants to demonstrate shared genetic architecture across CH types. Our analysis suggests a cellular evolutionary trade-off between different types of CH, with LOY occurring at lower rates in individuals carrying mutations in established CHIP genes. We observed co-occurrence of CHIP and mCAs with overlap at TET2, DNMT3A, and JAK2, in which CHIP precedes mCA acquisition. Furthermore, individuals carrying overlapping CH had high risk of future lymphoid and myeloid malignancies. Finally, we leverage shared genetic architecture of CH traits to identify 15 novel loci associated with leukemia risk

    Clinical and Molecular Characteristics of Carbapenemase-Producing E. coli Strains from Patients with Biliary System Diseases and Hematological Malignancies

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    Xiaojuan Qian,1,2,* Weiwei Bao,1,2,* Shenghai Wu,2 Jiawei Zhou,3 Yunxing Yang,2 Xianjun Wang,2 Daojun Yu,2 Qiong Chen2 1Department of Laboratory Medicine, Affiliated Hangzhou First People‚Äôs Hospital, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, People‚Äôs Republic of China; 2Department of Laboratory Medicine, Affiliated Hangzhou First People‚Äôs Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People‚Äôs Republic of China; 3State Key Laboratory of Diagnosis and Treatment for Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People‚Äôs Republic of China*These authors contributed equally to this workCorrespondence: Qiong Chen, Department of Laboratory Medicine, Affiliated Hangzhou First People‚Äôs Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310006, People‚Äôs Republic of China, Email [email protected]: This study aims to investigate the clinical and molecular characteristics of carbapenemase-producing E. coli strains (CPECO).Patients and Methods: We collected 38 non-repetitive CPECO strains, identified them using MALDI-TOF, and assessed their antimicrobial susceptibility via the VITEK-Compact II system. We gathered demographic and clinical patient data. Phenotypic assays were employed to detect carbapenemase types. Polymerase chain reaction (PCR) was utilized to identify the carbapenemase genes. Seven housekeeping genes were amplified and sequenced to determine the multilocus sequence typings (MLSTs).Results: These CPECO strains, primarily isolated from aseptic site and stool screening specimens, exhibited significant resistance to most clinical antibiotics, except for tigecycline and amikacin. Most patients had underlying medical conditions and underwent invasive procedures. There were significant differences among patients concerning the presence of malignancies, digestive system disorders, endoscopic retrograde cholangiopancreatography (ERCP) surgeries and abdominal drainage tubes. However, no significant differences were observed among patients regarding conditions, including hypertension, diabetes, respiratory diseases, urinary diseases and cardiovascular diseases, as well as invasive procedures such as deep venous catheterization, endotracheal intubation and gastrointestinal catheterization. Metallo-ő≤-lactamase was primarily responsible for carbapenem resistance, including blaNDM-5(24/38), blaNDM-1(5/38), blaNDM-9(1/38) and blaIMP-4(1/38). Additionally, 7 CPECO strains carried blaKPC-2. The distribution of CPECO sequence types (STs) was diverse, with seven strains being ST131, six strains being ST410, three strains each of ST1196 and ST10, although most STs were represented by only one strain.Conclusion: CPECO infections in patients with biliary system diseases may result from intestinal CPECO translocation, with ERCP surgery potentially facilitating this. Meanwhile, malignant tumor was found to be a significant factor affecting CPECO infections in patients with hematological diseases. blaNDM-5, blaNDM-1 and blaNDM-9 were primarily responsible for carbapenem resistance in CPECO strains. The emergence of carbapenem-resistant ST131 and ST410 strains should be alert to prevent the spread of carbapenem-resistant genes within high-risk epidemic clones.Keywords: carbapenemase-producing E. coli, underlying diseases, endoscopic retrograde cholangiopancreatography, ERCP, ND

    Very high energy gamma-ray emission beyond 10 TeV from GRB 221009A

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    International audienceThe highest energy photons from gamma-ray bursts (GRBs) have important implications for the physics of particle acceleration and constraints on the extragalactic background light (EBL). Here we report for the first time the detection of photons beyond 10 TeV from the unprecedentedly brightest GRB 221009A by the Large High Altitude Air-shower Observatory (LHAASO). The LHAASO-KM2A detector registered more than 140 photons with energies above 3 TeV from GRB 221009A during 230‚ąí-900s after the trigger. The intrinsic energy spectrum of gamma-rays can be described by a power-law after correcting for EBL absorption, with the highest energy photon of 13 TeV. Such a hard spectrum challenges the synchrotron self-Compton (SSC) scenario of relativistic electrons for the afterglow emission above several TeV, because the Klein-Nishina effect and the internal ő≥ő≥\gamma\gamma absorption within the GRB generally lead to a spectral softening towards high energies. Observations of photons up to 13 TeV from a source with a measured redshift of z=0.151 requires more transparency in intergalactic space than previously expected, in order to avoid an unusual pile-up at the end of the spectrum. Alternatively, one may invoke new physics such as Lorentz Invariance Violation (LIV) or assume an axion origin of very high energy (VHE) signals
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