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Recently, physics-informed neural networks (PINNs) have emerged as a promising method for solving partial differential equations (PDEs). In this study, we establish a deep learning computational framework, HL-nets, for computing the flow field of hydrodynamic lubrication involving cavitation effects. Two classical cavitation conditions, i.e., the Swift-Stieber (SS) condition and the Jakobsson-Floberg-Olsson (JFO) condition, are implemented in the PINNs to solve the Reynolds equation. For the non-negativity constraint of the SS cavitation condition, a penalizing scheme with a residual of the non-negativity and an imposing scheme with a continuous differentiable non-negative function are proposed. For the complementarity constraint of the JFO cavitation condition, the pressure and cavitation fraction are taken as the neural network outputs, and the residual of the Fischer-Burmeister (FB) equation constrains their complementary relationships. Multi-task learning (MTL) methods are applied to balance the newly introduced loss terms described above. To estimate the accuracy of HL-nets, we present a numerical solution of the Reynolds equation for oil-lubricated bearings involving cavitation. The results indicate that the proposed HL-nets can highly accurately simulate hydrodynamic lubrication involving cavitation phenomena. The imposing scheme can effectively improve the accuracy of the training results of PINNs, and it is expected to have great potential to be applied to different fields where the non-negativity constraint is needed.

In this paper, the NU308 bearing rings were subjected to strengthen grinding treatment (SGT) at ambient temperature. And the running reliabilities of specimens that subjected to SGT and conventional treatment (CT) were respectively investigated by testing dynamic properties including the running temperature, vibrations, and surface burning. Moreover, the residual stress, microtopography, and microstructures on the cross-section were respectively tested with residual stress analyzer and field-emission scanning electron microscopy. The results showed that the running reliabilities of the specimen after SGT had been significantly improved with the reduction of running temperature, vibration, and surface burning. Further study showed that the specimen’s surface was filled with disordered micropores after SGT compared to the regular strip texture on the CT specimen’s surface, and the maximum residual compressive stress induced by SGT was about −900 MPa. Moreover, the thickness of the residual compressive stress layer was over 180 µm, while the thickness of severe plastic deformation layer was about 50 µm.

Additional file 1: Supplementary Table 1. Response to diverse initial bid amounts across sociodemographics among Chinese female health care workers. Supplementary Table 2. Attitude shift towards HPVvaccines between two payment scenarios across sociodemographics.

In 2019, transferable plasmid-borne tet(X3)/tet(X4) genes conferring high-level tigecycline resistance were identified in Enterobacteriaceae and Acinetobacter. These transferable tet(X) variants are associated with different plasmids and could further spread and disseminate through associated mobile plasmids, raising public concern. In this study, we report the identification and characterization of two novel plasmids carrying tet(X4) in Escherichia coli isolated from retail chicken meat. We believe that our study contributes to our understanding of the genetic environment of tet(X4) and their transferability and capability of recombination and integration with other resistance genes in plasmids.

Methicillin-resistant Staphylococcus aureus (MRSA) is a major multidrug-resistant (MDR) opportunistic pathogen that is responsible for nosocomial infections worldwide. The emergence of MRSA in food-producing animals has heightened concerns regarding the presence of MRSA in foods having an animal origin. The objectives of this study were to determine the prevalence of MRSA in different sources, including retail food, food-producing animals, and food handlers in Sichuan province. During 2007-2015, S. aureus was isolated from samples having different origins. Susceptibilities of MRSA to a panel of 12 antimicrobial agents were determined according to Clinical and Laboratory Standards Institute (CSLI) procedures. Pulsed-field gel electrophoresis, spa typing, staphylococcal chromosomal cassette (SCC) mec typing, and multilocus sequence typing (MLST) were used to characterize the relationship between these isolates. A total of 756 S. aureus were isolated from 11,067 samples. Of these, 52 isolates were classified as MRSA based on the presence of mecA genes. An antimicrobial susceptibility assay indicated that CHL-CLI-ERY-FOX-OXA-PEN-TET (n = 10) and CHL-CIP-CLI-ERY-FOX-OXA-PEN-TET (n = 8) were the two predominant MDR profiles in the isolates. Using 60% genetic similarity as a cutoff, the 52 MRSA isolates were grouped into 6 clusters having 34 pulsotypes. MLST typing showed seven multilocus sequence types (STs) with ST59 and ST9 being the most common. Six SCCmec types were identified in all MRSA isolates. The MRSA isolates had relatively low prevalence in Sichuan province. Clonal expansion is not involved in the dissemination of MRSA from food origins. Considering the threat of MRSA to public health, further surveillance is required to monitor the prevalence of food-related MRSA.

The effects of operation height and tree shape on droplet deposition in citrus trees using an unmanned aerial vehicle (UAV) were investigated in this study. When the operation height was 1.2 m and the flight speed was 3.5 m s−1, the droplet density and droplet coverage rate were maximized in all the canopies. The droplets exhibited the most uniform distribution (CV = 32.44%) in the lower layer of inverted triangle-shaped trees. The droplet density in the lower layer of inverted triangle-shaped trees was 48.04% higher than that in triangle-shaped trees. There was no statistically significant difference between the middle and lower layers of inverted triangle-shaped trees. The uniformity of the droplet deposition distribution was studied in six parts of the citrus trees at an operation height of 1.2 m. The results indicated that the front, middle, rear, left and centre parts displayed uniform distributions, but the right part of the inverted triangle-shaped trees did not. This difference might have been caused by a deviated flight route due to manual control error or by droplet drift from the wind originating from the right.

In this study, the tensile tests of Sn-0.3Ag-0.7Cu-xMn composite solder alloys were carried out at strain rates of 1 × 10 −4 s −1 , 1 × 10 −3 s −1 , and 1 × 10 −2 s −1 over a range of test temperatures of 20 °C, 60 °C, and 120 °C. The tensile tests of Cu/Sn-0.3Ag-0.7Cu-xMn/Cu solder joints aged at 150 °C for 0, 144, 288, 576, 864, and 1152 h were conducted under a strain rate of 1 × 10 −3 s −1 at 20 °C. Scanning electron microscope (SEM) was used to observe the fracture surfaces of solder alloys and joints. Results show that the Mn-containing solder alloys and joints have higher ultimate tensile strength (UTS) than Mn-free due to the effect of particle hardening. The UTS of Sn-0.3Ag-0.7Cu-xMn composite solder alloys has a logarithmic relation with strain rate and decreases with an increase of test temperature. The tensile strengths of both Sn-0.3Ag-0.7Cu-xMn solder alloy and solder joints reach the highest value when 0.1 wt.% Mn nanoparticles is added. With an increase in aging time, the tensile strength of all solder joints shows a decreasing trend as the interfacial intermetallic compound (IMC) layer becomes thicker and thicker. This results in the fracture mode of the solder joint gradually changing from the initial ductile fracture in the solder joints into the mixed fracture mode of both the ductile and the brittle fracture, and finally to the brittle fracture mode along interface IMC.

Fine-grained image Classification is an important task in computer vision. The main challenge of the task are that intra-class similarity is large and that training data points in each class are insufficient for training a deep neural network. Intuitively, if we can learn more discriminative features and more detailed features from fined-grained images, the classification performance can be improved. Considering that channel attention can learn more discriminative features, spatial attention can learn more detailed features, this paper proposes a new spatial attention mechanism by modifying Squeeze-and-Excitation block, and a new mixed attention by combining the channel attention and the proposed spatial attention. Experimental results on two small-sample fine-grained image classification datasets demonstrate that on both VGG16 network and ResNet-50 network, the proposed two attention mechanisms achieve good performance, and outperform other referred fine-grained image classification methods.

For achieving accurate detection of greenhouse planting environment and obtaining agricultural information such as illumination and air conditions, a multi-node greenhouse environment information collection system was designed combining environment information integrated sensor fusion technology and Internet of Thing technology. The experimental results show that the system is stable in operation, and the collected environmental information data has high precision, which can better detect greenhouse plantations and provide reliable environmental information data.

For solving the compatibility problem of the control system to different track vehicle platforms, a track vehicle cross-platform control system is designed, which reduces the development difficulty of track vehicle control system based on different control platforms, avoids repeated development, and also provides an application interface for the subsequent development of other functions. In the design, the hardware and software parts of the control system are constructed with the general multi-processor hardware architecture and μC/OS operating system kernel. For adapting the multi-processor hardware architecture, a multi-processor collaboration management task is designed. At the same time, the hardware interface of the bottom hardware management layer and the module package of the top application layer are added, so that the hardware development and software development are isolated from each other. The control module developed by this method can be portable to the track vehicle of other platforms, which is convenient for the development and application of different control system.

As the development of artificial intelligence continues, mobile vehicle has increasingly wider applications in intelligent patrol, intelligent crop, etc. For meeting the mobile vehicle's demands, the positioning and navigation system of mobile vehicle is established based on SLAM (Simultaneous Localization and Mapping).The system adopts Raspberry Pi as the main controller and STM32 as the sub-controller. The function of SLAM is realized by data combination and coordinate correlation conversion, after which the target point is located on the map and the functions of positioning and investigation is achieved. The experiment shows that the system can effectively establish the map, obtain the moving vehicle's coordinate information and realize its function of automatic investigation.

OBJECTIVE To investigate the in vivo inhibitory effects of sodium houttuyfonate (SH) on symptom pattern of Qi -deficiency in rats induced by infection of bacterial biofilm on rat respiratory tract. METHODS Symptom pattern is a term used in Traditional Chinese Medicine (TCM) to define a cluster of symptoms in a medical condition. Based on the pattern, TCM therapies are administered. The symptom pattern used in this study was lung- Qi deficiency pattern identified in rats, which was induced by nasal intubation drip of Pseudomonas aeruginosa (P. aeruginosa) (two strains) to form bacterial biofilm on airway combined with stimulation of cold and fatigue. We measured the variations of the symptoms of the pattern, weight, spleen and thymus index, blood gas, lung bronchial tissue pathology and cytokine of rat in different treatments and control groups. RESULTS The rats of SH-treatment groups had not showed typical symptoms comparing with model group in the early stage of infection. The weight, spleen and thymus index of the SH-treatment groups were significantly higher comparing with untreated model group. The SH-treatment groups also showed higher O 2 partial pressure and lower CO 2 partial pressure than model group. Furthermore, we found that the bronchopulmonary section of SH-treatment groups not showed typical pathogenic variation in model group. The comparison of cytokine concentration in different groups indicated that SH could prevent the over-production of cytokine to reduce the inflammation occurrence. CONCLUSION In the early stage of airway infection by biofilm of P. aeruginosa, application of SH can prevent the occurrence of lung- Qi deficiency pattern.

According to Ming's classification, gastric cancer (GC) can be divided into two types: expanding and infiltrative. The two types are readily recognizable by histology: expanding carcinomas grow en masse and by expansion, resulting in the formation of discrete tumour nodules, whereas in infiltrative carcinoma, tumour cells invade individually. Both types show varying degrees of cell maturation. The two types of carcinomas have vastly different pathological and clinical features. However, little is known concerning the mechanisms underlying these differences since no GC cell line models are available. For comprehensive and insightful analyses of mechanisms and treatment methods, new cell lines derived from expanding- and infiltrative-type gastric tumours are urgently needed. In the present study, we established an expanding-type GC cell line from a 72-year-old male patient. Different in vitro and in vivo methods were used to characterize the phenotypes of this cell line. This GC cell line was named XGC-2 and had an ~60 h doubling time. The cell line displayed strong colony formation and tumourigenicity in nude mice and had complicated chromosomal abnormalities. XGC-2 cells showed some markers of epithelial-to-mesenchymal transition (EMT), with decreased E-cadherin expression levels and increased vimentin expression levels. The XGC-2 cell line may be useful for future studies of GC development, progression, metastasis and therapy.

A microfluidic chip driven by capillary force has the advantage of low cost and ease of manufacturing in batches, and its flow behavior is dominated by the geometry and surface characteristics of the microchannel. The design of mirochannel structures is very important for the microfluidic chips. This study presents a semi analytical method for the design of capillary microchannel. In this method, the quasi-steady state approximate solution method of the Young–Laplace equation is used to derive the capillary surface tension, and the parallel flow assumption based on the Reynolds equation is used to derive the resistance of the channel wall. A computational fluid dynamics simulation is used to provide the inlet effect coefficient and channel shape effect coefficient of this model. The availability of the semi analytical model is verified by the experiment. This model realizes the flow analysis of two-dimensional capillary flow channel with a continuous shape of the flow channel wall, providing a fast and accurate method for the structural design of the microfluidic chip driven by capillary force.

It is attractive and meaningful to apply the lattice Boltzmann method (LBM) to electrohydrodynamic (EHD) problems. As an important and fundamental problem in EHD, the behavior of freely-suspended liquid drops subjected to electrostatic fields was simulated with a 2-D LBM by means of the permittivity-density relation proposed by the authors and Peng’s multiphase LBM which can obtain high liquid-to-vapor density ratio and low liquid-phase compressibility. The phenomena and laws of deformation, especially the instable behavior of the liquid drops were well simulated. And two important critical parameters, i.e. the critical permittivity ratio and the critical electric-field strength were obtained. These results agree with the corresponding theories and experiments. The simulations show the particular advantages and potential of the LBM in studying multiphase electrohydrodynamic problems.

This paper explores some problems concerning ancient Chinese classical linguistics. It is maintained that there are both similarities and obvious differences between it and western philology. The development of ancient Chinese linguistics from the Pre-Qin Period to the Qing Dynasty can be divided into five stages: the embryonic stage, the stage for laying the foundation, the preparatory stage, the stage of growth, and the stage of overall revival and prosperity. The literature produced during this period can be grouped in six categories: gloss exegesis, orthographical form and meaning, phonological form and meaning, historical phonology, grammar on function words, and rhetoric. It is pointed out that, in researching the theoretical history of ancient Chinese linguistics, great importance should be attached to the consistency between history and theoretical logic, cultural background as reference, and textual research methodology.

Ultra-high strength X100 welded pipe can be used in the construction of long distance oil and gas pipeline to improve transmission capacity and reduce operation cost. By using the way of thermo-simulation and pilot rolling, the CCT (Continuous Cooling Transformation) diagram and the relationship between ACC (Accelerated Cooling) parameters, microstructure and mechanical properties were studied for the designed X100 pipeline steel with low carbon, high manganese and niobium micro-alloyed composition in lab. The analysis of CCT diagram indicates that the suitable hardness and microstructure can be obtained in the cooling rate of 20~80°C/sec. The pilot rolling results show that the ACC cooling start temperature below Ar3 phase transformation point is beneficial to increase uniform elongation, and the cooling stop temperature of 150~350°C is helpful to obtain high strength and toughness combination. Based on the research conclusions, the X100 plate and UOE pipe with dimension in O.D.1219×W.T.14.8mm, O.D.1219×W.T.17.8mm, designed for the natural gas transmission pipeline, were trial produced. The manufactured pipe body impact absorbed energy at −10°C is over 250J. The DWTT shear area ratio at 0°C is over 85%. The transverse strength meets the X100 grade requirement, and uniform elongation is over 4%. The X100 plate and UOE pipe with dimension in O.D.711×W.T.20.0mm, O.D.711×W.T.12.5mm, designed for an offshore engineering, were also trial produced. The average impact absorbed energy of pipe body at −30°C is over 200J. The average impact absorbed energy of HAZ (Heat-affected zone) and WM (Welded Seam) at −30°C is over 100J. And the good pipe shapes were obtained

MicroRNAs (miRs) play important roles in modulating gene expression during the processes of tumorigenesis and tumor development. Previous studies have found that miR-145 is down-regulated in the stomach neoplasm and is related to tumor migration and invasion. However, both the molecular mechanism and function of miR-145 in gastric cancer remain unclear. The present study is the first demonstration of the significant down-regulation of miR-145 expression in infiltrative gastric cancer compared to expanding gastric cancer. Additionally, correlation analyses revealed strong inverse correlations between miR-145 and FSCN1 expression levels in infiltrative gastric cancer. Furthermore, we demonstrated that miR-145 directly targets FSCN1 and suppresses cell migration and invasion in gastric cancer. Knocking down the expression of FSCN1 led to the suppression of migration and invasion in gastric cancer cells, and re-expressing FSCN1 in miR-145-overexpressing cells reversed their migration and invasion defects. Thus, we concluded that miR-145 regulates cell migration and invasion in gastric cancer primarily by directly targeting FSCN1.

The temperature field of mechanical seals was studied by numeric simulation and experiment, where was only quenching but not washing. The standard k-e model was used as turbulence model. Through numerical simulation of FLUENT, this paper calculated the temperature field, including the seal and the flow. By means of embedding thermocouple in static ring, the temperature of several points along the radial direction and the axial direction were measured respectively. The computational results were in agreement with the experimental data, which indicated that the present numerical method was effective. The experimental and numerical results showed that the maximum temperature point in the seal face was neat the inner diameter. The nearer to the seal face axially, the higher thermal gradient. The temperature and the inlet position of cooling water would affect the temperature field, and reasonable design was necessary.

Variable block size motion estimation in H.264 not only requires large computation complexity but also needs huge memory bandwidth. This paper proposes one high data reuse VLSI architecture for variable size motion estimation. The multi-bank memory organization reduces control complexity of reading and writing on-chip memory. The 16 4times4 sub-block sums of absolute differences (SADs) are combined from 256 primitive SADs by two levels cross network. Then other block size SADs can be obtained by reusing the 4times4 sub-block SADs. This architecture has been designed and synthesized in HJTC 0.18 um technology. The result shows it consists of 176 K gates and 41.6 KByte SRAM, operates at 55.6 MHz. The architecture allows the real-time processing of HDTV (1280times720) at 60 fps in a search range [-8, +7].