Deep learning (DL) has been widely used in bearing fault diagnosis. In particular, convolutional neural networks (CNNs) improve diagnosis accuracy by extracting excellent fault features. However, CNN lacks an explicit learning mechanism to distinguish between different fault characteristics in the input signal to the diagnosis results. This article presents a new end-to-end depth framework called multi-head self-attention convolution neural network (MSA-CNN) for bearing fault diagnosis. Firstly, we adopt a data pre-processing method that directly converts one-dimensional (1D) original signals into two-dimensional (2D) grayscale images, which is simple to implement and preserves the complete information of the original signal. Secondly, multi-head self-attention (MSA) is first constructed to aggregate the global information and adaptively assign weights to the input signal's features. Thirdly, the CNN with small-scale kernels extracted detailed local features. Finally, the learned high-level representations are fed into the full connect (FC) layer for fault diagnosis. The performance of the MSA-CNN is validated on different datasets. The results show that the proposed MSA-CNN can significantly improve fault diagnosis accuracy compared with the other state-of-the-art methods and has excellent noise immunity performance.

A low-cost and computer-controlled graphitization system connected to an elemental analyzer (EA) has been designed and built at the NTUAMS Lab. This semiautomatic system equips 6-unit reactors for the graphitization of CO2 with H2 on the iron catalyst. The entire procedure takes about 7 hours for iron conditioning, sample combustion and loading, and graphitization. The system can produce good-quality graphite for samples containing 0.5–1.6 mg carbon mass, with the pressure yield of graphitization ranging from 57.7% to 87.1%. The average values of OXI and OXII agree well with the consensus value, but the result of ANU sucrose was observed to be slightly higher than the reported one. The background samples of anthracite over ten months yielded an average of 0.38±0.10 pMC (n=21) corresponding to a 14C age of 45 kyr BP. Intercomparison samples L and M of FIRI exhibit that the measured 14C ages are almost identical to the consensus values and have a small spread in these values. The system has been carrying out graphitization for total organic carbon (TOC) of peat samples, and providing a more efficient and convenient way for AMS 14C dating.

This study assessed the efficacy of ThinPrep cytologic test and human papillomavirus (HPV) co-test in cervical cancer screening during pregnancy. A cohort of 8,712 pregnant women from Ren Ji Hospital participated in the study. Among them, 601 (6.90%) tested positive for high-risk HPV (HR-HPV) and 38 (0.44%) exhibited abnormal cytology results (ASCUS+). Following positive HR-HPV findings, 423 patients underwent colposcopy, and 114 individuals suspected of having high-grade squamous intraepithelial lesion and cervical cancer (HSIL+) underwent cervical biopsy. Histological examination revealed 60 cases of normal pathology (52.63%), 35 cases of low‐grade squamous intraepithelial lesion (30.70%), 17 cases of HSIL (14.91%), and 2 cases of cervical cancer (1.75%). The incidence of HSIL+ in HPV 16/18 group was significantly higher than that in non-HPV16/18 group (10.53% vs. 6.14%, P < 0.05). Subsequent evaluation of the clinical performance of cytology alone, primary HPV screening, and co-testing for HSIL+ detection revealed that the HSIL+ detection rate was lowest with cytology alone. These findings suggest that HPV testing, either alone or combined with cytology, presents an efficient screening strategy for pregnant women, underscoring the potential for improved sensitivity in cervical cancer screening during pregnancy. The significantly higher incidence of HSIL+ in the HPV16/18 group emphasizes the importance of genotype-specific considerations.

The role of Mn oxide in the abiotic formation of humic substances has been well demonstrated. However, information on the effect of crystal structure and surface-chemical characteristics of Mn oxide on this process is limited. In the present study, hexagonal and triclinic birnessites, synthesized in acidic and alkali media, were used to study the influence of the crystal-structure properties of birnessites on the oxidative polymerization of hydroquinone and to elucidate the catalytic mechanism of birnessites in the abiotic formation of humic-like polymers in hydroquinone-birnessite systems. The intermediate and final products formed in solution and solid-residue phases were identified by UV/Visible spectroscopy, atomic absorption spectrometry, Fourier-transform infrared spectroscopy, X-ray diffraction, solid-phase microextraction-gaschromatography-mas ss pectrometry, ion chromatography, and ultrafiltration. The degree of oxidative polymerization of hydroquinone wasenhanced with increase in the interlayer hydrated H+, the average oxidation state (AOS), and the specific surface area of birnessites. The nature of the functional groups of the humic-like polymers formed was, however, almost identical when hydroquinone was catalyzed by hexagonal and triclinic birnessites with similar AOS of Mn. The results indicated that crystal structure and surface-chemistry characteristics have significant influence on the oxidative activity of birnessites and the degree of polymerization of hydroquinone, but have little effect on the abiotic formation mechanism of humic-like polymers. The proposed oxidative polymerization pathway for hydroquinone isthat, asit approachesthe birnessite, it formsp recursor surface complexes. Asa strong oxidant, birnessite accepts an electron from hydroquinone, which is oxidized to 1,4-benzoquinone. The coupling, cleavage, polymerization, and decarboxylation reactionsaccompany the generation of 1,4-benzoquinone, lead to the release of CO2 and carboxylic acid fragments, the generation of rhodochrosite, and the ultimate formation of humic-like polymers. These findings are of fundamental significance in understanding the catalytic role of birnessite and the mechanism for the abiotic formation of humic substances in nature.

In order to establish a compact all-optical Thomson scattering source, experimental studies were conducted on the 45 TW Ti: sapphire laser facility. By including a steel wafer, mixed gas, and plasma mirror into a double-exit jet, several mechanisms, such as shock-assisted ionization injection, ionization injection, and driving laser reflection, were integrated into one source. So, the source of complexity was remarkably reduced. Electron bunches with central energy fluctuating from 90 to 160 MeV can be produced. Plasma mirrors were used to reflect the driving laser. The scattering of the reflected laser on the electron bunches led to the generation of X-ray photons. Through comparing the X-ray spots under different experimental conditions, it is confirmed that the X-ray photons are generated by Thomson scattering. For further application, the energy spectra and source size of the Thomson scattering source were measured. The unfolded spectrum contains a large amount of low-energy photons besides a peak near 67 keV. Through importing the electron energy spectrum into the Monte Carlo simulation code, the different contributions of the photons with small and large emitting angles can be used to explain the origin of the unfolded spectrum. The maximum photon energy extended to about 500 keV. The total photon production was 107/pulse. The FWHM source size was about 12 μm.

This article outlines the research progress on radiocarbon (14C) dating of the Erlitou site. The Erlitou site, belonging to the Bronze Age, located in Yanshi, Henan province, China, was discovered by archaeologists in 1959 when they investigated the Xia people’s remains in the area where the Xia people lived according to the records of ancient documents. Since then, there has been a standing debate about whether the site belongs to the Xia or Shang dynasty. By the mid-1990s, several hundred discussion articles on the issue had been published, but the question was still unresolved. Therefore, evidence from the chronology has attracted a great amount of attention. The dating of the Erlitou site began in the 1970s, and since the Xia-Shang-Zhou Chronology Project began in the mid-1990s, by application of wiggle-matching on the basis of improving the dating accuracy, the date of the Erlitou site has gradually become clear, which provides a basis for the archaeological research on the Xia and Shang dynasties.

Trailing vortices typically persist into the extreme far-wake where the asymptotic perturbation dominates. In this work, we investigate the mechanism underlying the asymptotic growth of perturbation in trailing vortices by looking into the linear instabilities of two canonical trailing vortex systems, namely an isolated vortex and a co-rotating vortex pair with axial flow, generated by an M6 swept wing without/with winglets in a wind tunnel experiment. The dynamics and wandering phenomena of both vortex configurations are characterized by stereoscopic particle image velocimetry (SPIV). Their linear perturbation modes are acquired by local and bi-global linear stability analyses. For the isolated trailing vortex, the dominating perturbation mode is found to be a viscous, unstable Mode-A counter to the vortex rotation ($m>0$), while Mode-A with $m\leqslant 0$ is essentially damped and Mode-P, which is exclusive to $|m|\leqslant 1$, remains marginally stable. For the co-rotating vortex pair, the upper vortex is subject to an unstable, azimuthal perturbation, while the dominating perturbation of the lower vortex is radial. The perturbation mode of the upper vortex is more unstable than that of the lower vortex. The difference is supported by the corresponding wandering amplitude. The dominating modes of the two vortex configurations manifest an identical feature of azimuthal perturbations penetrating the core boundary. The dominating mode overwhelms those centre modes confined within the core. For both vortex configurations, a limiting penetration depth exists, where the perturbation is most amplified asymptotically. The limiting penetration depth is ascribed to the alignment of the critical point with vortex shear. For the isolated vortex, it is the shear layer at the core boundary; for the vortex pair, it is the mutual shear layer of both vortices. The asymptotic growth of perturbations is thus attributed to an interaction between the respective characteristic layers of the perturbation and the flow at the leading order.

Echinococcus shiquicus is currently limited to the Qinghai–Tibet plateau, a large mountainous region in China. Although the zoonotic potential remains unknown, progress is being made on the distribution and intermediate host range. In this study, we report E. shiquicus within Gansu and Qinghai provinces in regions located not only around the central areas but also the southeast edge of the plateau and describe their genetic relationship with previous isolates from the plateau. From 1879 plateau pikas examined, 2.39% (95% CI 1.79–3.18) were infected with E. shiquicus. The highest prevalence of 10.26% (4.06–23.58) was recorded in Makehe town, Qinghai province. Overall the prevalence was marginally higher in Qinghai (2.5%, CI 1.82–3.43) than in Gansu (2%, CI 1.02–3.89). The cox1 and nad1 genes demonstrated high and low haplotype and nucleotide diversities, respectively. The median-joining network constructed by the cox1–nad1 gene sequences demonstrated a star-like configuration with a median vector (unsampled haplotype) occupying the centre of the network. No peculiar distinction or common haplotype was observed in isolates originating from the different provinces. The presence of E. shiquicus in regions of the southeast and northeast edges of the Qinghai–Tibet plateau and high genetic variation warrants more investigation into the haplotype distribution and genetic polymorphism by exploring more informative DNA regions of the mitochondrial genome to provide epidemiologically useful insight into the population structure of E. shiquicus across the plateau and its axis.

In this paper, the generation of relativistic electron mirrors (REMs) and the reflection of an ultra-short laser off this mirrors are discussed, applying two-dimensional particle-in-cell (2D-PIC) simulations. REMs with ultra-high acceleration and expanding velocity can be produced from a solid nanofoil illuminated normally by an ultra-intense femtosecond laser pulse with a sharp rising edge. Chirped attosecond pulse can be produced through the reflection of a counter-propagating probe laser off the accelerating REM. In the electron moving frame, the plasma frequency of the REM keeps decreasing due to its rapidly expanding. The laser frequency, on the contrary, keeps increasing due to the acceleration of REM and the relativistic Doppler shift from the lab frame to the electron moving frame. Within an ultra-short time interval, the two frequencies will be equal in the electron moving frame, which leads the resonance between laser and REM. The reflected radiation near this interval and the corresponding spectra will be amplified due to the resonance. Through adjusting the arriving time of the probe laser, certain part of the reflected field could be selectively amplified or depressed, leading to the selectively adjusting of the corresponding spectra.

A Na-montmorillonite (Na-MMT) was activated with HNO3 (20 wt.%) solution at various temperatures and times to obtain acid-activated MMT (Acid-MMT). Zinc (4 wt.%) was supported on Acid-MMT via the impregnation method using Zn(NO3)2⋅6H2O as a precursor. The catalytic performance of the Zn/Acid-MMT for the aromatization of heptane was investigated. The amount and distribution of acidity of Acid-MMT, which could be adjusted by changing the acid activation time and temperature, significantly affected the heptane conversion and aromatics content. As a result, an efficient Zn/Acid-MMT catalyst for the aromatization reaction was obtained by optimizing the acid-treatment conditions of Na-MMT.

Northeastern China is a region of high tick abundance, multiple tick-borne pathogens and likely human infections. The spectrum of diseases caused by tick-borne pathogens has not been objectively evaluated in this region for clinical management and for comparison with other regions globally where tick-transmitted diseases are common. Based on clinical symptoms, PCR, indirect immunofluorescent assay and (or) blood smear, we identified and described tick-borne diseases from patients with recent tick bite seen at Mudanjiang Forestry Central Hospital. From May 2010 to September 2011, 42% (75/180) of patients were diagnosed with a specific tick-borne disease, including Lyme borreliosis, tick-borne encephalitis, human granulocytic anaplasmosis, human babesiosis and spotted fever group rickettsiosis. When we compared clinical and laboratory features to identify factors that might discriminate tick-transmitted infections from those lacking that evidence, we revealed that erythema migrans and neurological manifestations were statistically significantly differently presented between those with and without documented aetiologies (P < 0.001, P = 0.003). Twelve patients (6.7%, 12/180) were co-infected with two tick-borne pathogens. We demonstrated the poor ability of clinicians to identify the specific tick-borne disease. In addition, it is necessary to develop specific laboratory assays for optimal diagnosis of tick-borne diseases.

The Chinese Loess Plateau (CLP) in North China is an important terrestrial archive that witnessed the environmental changes and mammal and early human evolution in Asia over the past 2.6 Ma. Establishing precise ages for the Pleistocene faunas on the CLP is critical for better understanding of these environmental, biological, and archaeological issues. Here we report a new magnetostratigraphic record that places age constraints on the Linyi Fauna on the southeastern CLP. Our investigated 170-m-thick Linyi section mainly consists of two portions: (1) an overlying eolian Quaternary loess-paleosol sequence and (2) underlying fluvial-lacustrine sand and silty clay. Paleomagnetic results suggest that the composite section records the Brunhes chron, Jaramillo and Olduvai subchrons, and successive reverse polarity portions of the intervening Matuyama chron. The Linyi Fauna is located between Jaramillo and Olduvai subchrons in the fluvial-lacustrine interval, with an estimated age of ~1.5–1.6 Ma. Combining previously dated faunas, we establish a Pleistocene magnetochronology spanning from 2.54 to 0.65 Ma for the faunas on the CLP.

A comprehensive geochronological and geochemical study was carried out on the gneissic monzogranites, porphyritic granodiorites and charnockites in the Gaozhou complex of the Yunkai massif in the southern part of the South China block to better understand the Early Palaeozoic tectonic regime of the South China block. Laser ablation – inductively coupled plasma – mass spectrometry (LA-ICP-MS) U–Pb dating of zircons indicates an age of 453.2 ± 5.1 Ma to the formation of the gneissic monzogranites, whereas the porphyritic granodiorites and charnockites were generated at 437.0 ± 1.5 Ma and 435.2 ± 2.2 Ma, respectively. The gneissic monzogranites show geochemical features consistent with the high-K, calc-alkaline rock series and are strongly peraluminous. They have SiO2 contents ranging from 67.75 to 69.65 wt. % and relatively low CaO contents (1.66–1.94 wt. %). Their REE patterns are fractionated with enriched LREEs and negative Eu anomalies. The samples also show enrichment in LILEs (e.g. Rb and K) and Pb, and depletion in Sr, Ba and HFSEs (e.g. Nb, Ta, Ti and P). They have εNd(t) values of −8.2 to −7.7. Conversely, the porphyritic granodiorites and charnockites are characterized as medium-K, calc-alkaline rock series and weakly to strongly peraluminous. They exhibit pronounced depletions in HFSEs and positive Pb anomalies. Compared to the earlier gneissic monzogranites, these rocks have relatively lower SiO2 (65.50–69.36 wt. %), but higher CaO contents (3.34–4.05 wt. %), and have slightly lower εNd(t) values (−9.1 to −8.4). Petrography and geochemical compositions of the gneissic monzogranites indicate that they are S-type granite and likely formed by partial melting of Neoproterozoic to Early Palaeozoic immature metagreywackes; whereas The porphyritic granodiorites and charnockites are A-type granite and likely derived from low degrees of partial melting of the dry, granulitic residue depleted by prior extraction of granitic melt. The new data for the Caledonian granitoids in the Yunkai massif suggest that they were formed in a post-collisional tectonic setting. They represent the earliest post-collisional alkaline magmatism reported so far in the Yunkai massif, and thus indicate a tectonic regime switch, from compression to extension, as early as the Late Ordovician to Early Silurian (~450–435 Ma).

Palaeoproterozic metasedimentary rocks, also referred to as khondalites, characterized by Al-rich minerals, are extensively exposed in the nucleus of the Yangtze craton, South China block. Samples of garnet–sillimanite gneiss in the khondalite suite were collected from the Kongling complex for Nd isotopic and elemental geochemical study. These rocks are characterized by variable SiO2 contents ranging from 35.71 to 58.07 wt%, and have low CaO (0.45–0.84 wt%) but high Al2O3 (18.56–29.04 wt%), Cr (174–334 ppm) and Ni (42.5–153 ppm) contents. They have high CIW (Chemical Index of Weathering) values (90.4–94.7), indicating intense chemical weathering of the source material. The samples display light rare earth elements (LREE) enrichment with negative Eu anomalies (Eu/Eu*=0.40–0.68), and have flat heavy rare earth elements (HREE) patterns. The high contents of transition elements (e.g. Cr, Ni, Sc, V) and moderately radiogenic Nd isotopic compositions suggest that the paragneisses might be those of first-cycle erosion products of predominantly mafic rocks mixing with small amounts of felsic moderately evolved Archaean crustal source. Geochemical and Nd isotopic compositions reveal that at least some of the protoliths of Kongling khondalite were sourced from local pre-existing mafic igneous rocks in a continental arc tectonic setting. Combined with documented zircon U–Pb geochronological data, we propose that the Palaeoproterozoic high-pressure granulite-facies metamorphism, rapid weathering, erosion and deposition of the khondalites in the interior of the Yangtze craton might be related to a Palaeoproterozoic collisional orogenic event during 2.1–1.9 Ga, consistent with the worldwide contemporary orogeny, implying that the Yangtze craton may have been an important component of the Palaeoprotorozoic Columbia supercontinent.

The molecular basis of resistance to tribenuron-methyl, an acetolactate synthase (ALS)–inhibiting herbicide was investigated in four resistant (R) and three susceptible (S) flixweed populations. The resistance level in the R populations was assessed in whole-plant pot experiments in a greenhouse, and resistance indices ranged from 723 to 1422. The ALS genes of the three S populations and four R populations were cloned and sequenced, and the full coding sequence of the ALS gene of flixweed was 2,004 bp. The sequences of the ALS genes of the three S populations collected from Shaanxi, Gansu, and Tianjin were identical. Comparison of the ALS gene sequences of the S and R populations with Arabidopsis revealed that proline at position 197 of the ALS gene was substituted by leucine in R population SSX-2, by alanine in R population SSX-3, and by serine in R populations TJ-2 and GS-2. In another study of two R flixweed populations from Hebei and Shaanxi, resistance was also related to mutation at position 197 of the ALS gene. Both studies confirmed tribenuron-methyl resistance in flixweed in China, with the resistance mechanism being conferred by specific ALS point mutations at amino acid position 197.

Carbon nanotube (CNT) reinforced A356 aluminum alloys cast nanocomposites containing lower CNT contents were successfully fabricated where the way of introducing diluted Al–8 wt% CNT master nanocomposite in A356 melts was used. The differential thermal analysis and x-ray diffraction results showed that aluminum carbide phases (Al4C3) were formed before Al melting. The formation of Al4C3 was then proved to improve the wettability of CNTs during Al melting. Effect of CNT addition on microstructure and mechanical properties of CNTs/A356 nanocomposites were investigated by optical microscopy, scanning electron microscopy, transmission electron microscopy, and universal tensile testing machine. The results showed that CNTs (<0.4 wt%) were well distributed in the CNTs/A356 nanocomposites. CNTs could greatly refine the microstructure of A356 alloy. The mechanical properties of CNTs/A356 nanocomposites were also enhanced by CNT addition. Fractography analysis revealed that CNTs were distributed uniformly throughout the fracture surface.