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The precision of short-term photovoltaic power forecasts is of utmost importance for the planning and operation of the electrical grid system. To enhance the precision of short-term output power prediction in photovoltaic systems, this paper proposes a method integrating K-means clustering: an improved snake optimization algorithm with a convolutional neural network–bidirectional long short-term memory network to predict short-term photovoltaic power. Firstly, K-means clustering is utilized to categorize weather scenarios into three categories: sunny, cloudy, and rainy. The Pearson correlation coefficient method is then utilized to determine the inputs of the model. Secondly, the snake optimization algorithm is improved by introducing Tent chaotic mapping, lens imaging backward learning, and an optimal individual adaptive perturbation strategy to enhance its optimization ability. Then, the multi-strategy improved snake optimization algorithm is employed to optimize the parameters of the convolutional neural network–bidirectional long short-term memory network model, thereby augmenting the predictive precision of the model. Finally, the model established in this paper is utilized to forecast photovoltaic power in diverse weather scenarios. The simulation findings indicate that the regression coefficients of this method can reach 0.99216, 0.95772, and 0.93163 on sunny, cloudy, and rainy days, which has better prediction precision and adaptability under various weather conditions. [ABSTRACT FROM AUTHOR]

With the expansion of the scale of electric power, high-quality electrical energy remains a crucial aspect of power system management and operation. The generation of reactive power is the primary cause of the decline in electrical energy quality. Therefore, optimization of reactive power in the power system becomes particularly important. The primary objective of this article is to create a multi-objective reactive power optimization (MORPO) model for distribution networks. The model aims to minimize reactive power loss, reduce the overall compensation required for reactive power devices, and minimize the total sum of node voltage deviations. To tackle the MORPO problems for distribution networks, the improved sparrow search algorithm–particle swarm optimization (ISSA-PSO) algorithm is proposed. Specifically, two improvements are proposed in this paper. The first is to introduce a chaotic mapping mechanism to enhance the diversity of the population during initialization. The second is to introduce a three-stage differential evolution mechanism to improve the global exploration capability of the algorithm. The proposed algorithm is tested on the IEEE 33-node system and the practical 22-node system. The results indicate a reduction of 32.71% in network losses for the IEEE 33-node system after optimization, and the average voltage of the circuit increases from 0.9485 p.u. to 0.9748 p.u. At the same time, optimization results in a reduction of 44.07% in network losses for the practical 22-node system, and the average voltage of the circuit increases from 0.9838 p.u. to 0.9921 p.u. Therefore, the proposed method exhibits better performance for reducing network losses and enhancing voltage levels. [ABSTRACT FROM AUTHOR]

As an indispensable component of coal-fired power plants, boilers play a crucial role in converting water into high-pressure steam. The oxygen content in the flue gas is a crucial indicator, which indicates the state of combustion within the boiler. The oxygen content not only affects the thermal efficiency of the boiler and the energy utilization of the generator unit, but also has adverse impacts on the environment. Therefore, accurate measurement of the flue gas's oxygen content is of paramount importance in enhancing the energy utilization efficiency of coal-fired power plants and reducing the emissions of waste gas and pollutants. This study proposes a prediction model for the oxygen content in the flue gas that combines the whale optimization algorithm (WOA) and long short-term memory (LSTM) networks. Among them, the whale optimization algorithm (WOA) was used to optimize the learning rate, the number of hidden layers, and the regularization coefficients of the long short-term memory (LSTM). The data used in this study were obtained from a 350 MW power generation unit in a coal-fired power plant to validate the practicality and effectiveness of the proposed hybrid model. The simulation results demonstrated that the whale optimization algorithm–long short-term memory (WOA-LSTM) model achieved an MAE of 0.16493, an RMSE of 0.12712, an MAPE of 2.2254%, and an R 2 value of 0.98664. The whale optimization algorithm–long short-term memory (WOA-LSTM) model demonstrated enhancements in accuracy compared with the least squares support vector machine (LSSVM), long short-term memory (LSTM), particle swarm optimization–least squares support vector machine (PSO-LSSVM), and particle swarm optimization–long short-term memory (PSO-LSTM), with improvements of 4.93%, 4.03%, 1.35%, and 0.49%, respectively. These results indicated that the proposed soft sensor model exhibited more accurate performance, which can meet practical requirements of coal-fired power plants. [ABSTRACT FROM AUTHOR]

To realize the high‐efficiency utilization of iron‐rich coal, it is necessary to conduct in‐depth research on the ash fusion characteristics and regulation mechanism. In this paper, the ash fusion temperature test of iron‐rich coal in Xinjiang (ZC) under different atmospheres was first carried out. Then, red mud (HJ) from Huajin Aluminum Industry and black water pipe scale (GDG) were selected as the additives. After the same ashing procedure, the two additives were mixed with iron‐rich coal ash in different proportions to realize the regulation of the chemical composition of the coal ash to improve the ash fusion characteristic. The ash fusion temperature (AFT) experiment was carried out in the automatic ash melting point analyzer, and high‐temperature ash melting slags at different temperatures were prepared. The mineral phases of coal ash and slag were characterized by XRD and compared with the Factsage simulation calculation results to reveal the influence mechanism of coal ash fusion temperature. The result shows that the fusion temperature of ZC iron‐rich coal ash is significantly different between oxidizing atmosphere and weak reducing atmosphere. Compared with the oxidizing atmosphere, the four characteristic temperatures of ZC iron‐rich coal ash are significantly lower under weak reducing conditions, and the difference is about 150°C. The addition of red mud and pipeline scale increased the fusion temperature of ZC coal ash to varying degrees. The addition of HJ ash has little effect on the deformation temperature of ZC coal ash, while the addition of different proportions of HJ ash significantly increases the flow temperature of ZC coal ash. When the addition ratio of HJ ash is 40%, the flow temperature FT of ZC coal ash increases most obviously, which is about 50°C. The addition of HJ ash and GDG ash will lead to an increase in the content of iron‐containing spinel, thereby increasing the ash flow temperature. [ABSTRACT FROM AUTHOR]

Few studies have examined the relationship at the microscopic spatial scale. In this study, multiple sources of data including mobile phone signal data, automatic fare collection system data, geo-information data, and street-view image data are combined to measure metro ridership and built environment at the plot or block scale. The Random Gradient Boosting Decision Tree was used to explore relationship between the built environment and ridership. The results show the following: (1) the relationship between built environment and ridership shows different types of curves. (2) The path distance to the metro station and the visual perception of road space have more significant impacts on ridership than road network density. (3) The location of the grid also affects grid-level metro ridership. The results suggest that planners should consider the locational factors, pay attention to the different effective thresholds of different variables on ridership and the longitudinal landscaping of non-motorized urban roads. [ABSTRACT FROM AUTHOR]

As a product of China's transportation development in the last decade, the issue of road traffic crashes among ride-hailing drivers has become a growing concern for public safety. This study aims to investigate the human factors contributing to traffic crashes among traditional taxi and ride-hailing drivers, and to compare the similarities and differences between the two groups of drivers. The data was collected from 877 taxi drivers and 906 full-time ride-hailing drivers through a self-reported survey. The structural equation model was used to investigate structural interrelationships between the financial burden, work-related fatigue (WRF), road safety attitude, aberrant driving behaviors (ADBs) of the drivers and their influences on work-traffic crashes. Relevant results showed that there were significant differences in the work status between the two groups of drivers. The heavy economic burden increased the perception of WRF among taxi drivers and contributed to traffic crashes. Ride-hailing drivers had a more positive attitude toward road safety and controlled their ADBs better. These results will help formulate policy recommendations aimed at improving road safety among taxi and ride-hailing drivers. [ABSTRACT FROM AUTHOR]

Plant factory is an important field of practice in smart agriculture which uses highly sophisticated equipment for precision regulation of the environment to ensure crop growth and development efficiently. Environmental factors, such as temperature and humidity, significantly impact crop production in a plant factory. Given the inherent complexities of dynamic models associated with plant factory environments, including strong coupling, strong nonlinearity and multi-disturbances, a nonlinear adaptive decoupling control approach utilizing a high-order neural network is proposed which consists of a linear decoupling controller, a nonlinear decoupling controller and a switching function. In this paper, the parameters of the controller depend on the generalized minimum variance control rate, and an adaptive algorithm is presented to deal with uncertainties in the system. In addition, a high-order neural network is utilized to estimate the unmolded nonlinear terms, consequently mitigating the impact of nonlinearity on the system. The simulation results show that the mean error and standard error of the traditional controller for temperature control are 0.3615 and 0.8425, respectively. In contrast, the proposed control strategy has made significant improvements in both indicators, with results of 0.1655 and 0.6665, respectively. For humidity control, the mean error and standard error of the traditional controller are 0.1475 and 0.441, respectively. In comparison, the proposed control strategy has greatly improved on both indicators, with results of 0.0221 and 0.1541, respectively. The above results indicate that even under complex conditions, the proposed control strategy is capable of enabling the system to quickly track set values and enhance control performance. Overall, precise temperature and humidity control in plant factories and smart agriculture can enhance production efficiency, product quality and resource utilization. [ABSTRACT FROM AUTHOR]

Fatigue crack growth (FCG) tests under constant amplitude loading and fracture toughness tests of SA508-III steel were performed in this work. The effect of the R-ratio on the FCG behavior of SA508-III steel was investigated. The results indicated that the FCG rate was insensitive to R-ratio. This steel presented better resistance to FCG compared to the data in the ASME code. The better property was attributed to the residual compressive stresses and high-angle grain boundaries in this steel. Additionally, the results revealed that the fracture toughness gradually decreased with the increased initial crack length. While the initial crack length was the same, the fracture toughness of the specimens with high stress intensity factor (SIF) fatigue loading decreased by ~ 6.61%. This was due to the higher local fatigue damage produced at the crack tip when the crack was prefabricated at a high SIF. Electron back-scatter diffraction (EBSD) results confirmed that microcracks, micro-voids, and high geometrically necessary dislocations density were distributed near the crack tip when prefabricated cracks under a high SIF, which provided more crack nucleation sites for crack growth and resulted in a decrease in fracture toughness. Both scanning electron microscope and EBSD analyses of the fractography were performed to investigate the fracture modes of SA508-III at different stages of crack growth. [ABSTRACT FROM AUTHOR]

The severity of collisions involving heavy trucks exhibits a difference between the flat and mountainous expressways. Based on 1,175 records of truck crashes from 2015 to 2020 on two typical expressways in China, a heteroskedastic ordered probit model was applied to determine the significant factors among driver-vehicle-roadway-environment interactions and their marginal effects on the collision severity outcomes. The modeling results demonstrated that some variables (i.e. speeding and risky following behaviors of drivers, existence of curves and downgrades, adverse weather, etc.) are significant predictors of truck crashes on both flat and mountainous expressways. In contrast, some variables were significantly correlated with truck crashes on only the flat expressway (upgrade section) or the mountainous expressway (involvement of multiple vehicles, truck’s overloading status, nighttime period). The findings, taken collectively, may be valuable as a reference for drafting traffic rules and implementing technical solutions to ensure a safer traffic environment for heavy trucks on expressways. [ABSTRACT FROM AUTHOR]

The damage evolution and spall behavior of copper under complex shockwave loading conditions were investigated using plate impact experiments with conical targets. Sweeping tensile waves were generated by the interaction of the released waves that were reflected from the free surfaces of the impactor and the cone surface. From the free-surface velocity profiles measured by multi-channel velocimetry, the classic pull-back spall signals were observed in incipient and complete spallation experiments. The spall strength estimated from the pull-back velocity strongly depended on the loading path and the loading wave profile. Post-experiment analysis based on the soft-recovery technique revealed that the damage distributions were very different from the bottom to the top of the conical target, but the corresponding free-surface velocity data measured at different locations suggested that similar responses occurred, which indicated that the spall strength was the critical threshold stress of micro-void nucleation or early growth. The fractography analysis of the fracture surfaces showed that metal micro-spheres were scattered in deep dimples, which indicated that the increase in temperature due to local severe plastic deformation around the voids was important. With the same set of model parameters, the plate impact spallation experiments with plane and conical targets were simulated using a critical damage evolution model. A good agreement was obtained between the simulations and experiments, which demonstrated the model capabilities for predicting the spall responses of metals under complex shockwave loading. [ABSTRACT FROM AUTHOR]

Scoliosis before the age of 5 years is referred to as early-onset scoliosis (EOS). While causes may vary, EOS can potentially affect respiratory function and lung development as children grow. Moreover, scoliosis can lead to thoracic insufficiency syndrome when aggravated or left untreated. Therefore, spinal thoracic deformities often require intervention in early childhood, and solving these problems requires new methods that include the means for both deformity correction and growth maintenance. Therapeutic strategies for preserving the growing spine and thorax include growth rods, vertically expandable titanium artificial ribs, MAGEC rods, braces and casts. The goals of any growth-promoting surgical strategy are to alter the natural history of cardiorespiratory development, limit the progression of underlying spondylarthrosis deformities and minimize negative changes in spondylothorax biomechanics due to the instrumental action of the implant. This review further elucidates EOS in terms of its aetiology, pathogenesis, pathology and treatment. [ABSTRACT FROM AUTHOR]

The objective of this study is to establish a model for predicting the outcome of endovascular aneurysm repair for abdominal aortic aneurysms using deep learning algorithms. We performed a case series analysis of 493 patients with infra-renal abdominal aortic aneurysm who underwent elective endovascular aneurysm repair procedures between January 2016 and December 2019 in our single center. ITK-SNAP software was used to draw the abdominal aortic aneurysms region of interest. Images were preprocessed and deep learning model was built using MATrix LABoratory. Randomly divided, 80% of the patients were used as the training set, and 20% of the patients were enrolled in the test set. The area under the curve from receiver-operating characteristic curve was used to evaluate the predictive effect of the model. To further understand the prediction process of the deep learning model, visualization techniques were used to analyze the features learned by the model and the response of the convolutional layer to the different outcomes of endovascular aneurysm repair. The mean follow-up was 32.0 months, including 156 patients (31.6%) experiencing endovascular aneurysm repair-related severe adverse events. Number of patients in the training set was 394 (of which 269 had no severe adverse events and 125 had severe adverse events) and the number of patients in test set was 99 (of which 68 had no severe adverse events and 31 had severe adverse events). By training on 92,012–93,925 computed tomography angiography images (n = 315) and validation on 22,269–24,182 computed tomography angiography images (n = 79), the deep learning model finally achieved encouraging predictive performance in the test set (n = 99) with an area under the curve of 0.81 SD0.01, accuracy 0.82 SD0.02, and F1 score 0.87 SD0.02. The visualization techniques improved the model interpretability. The deep learning model could be an efficient adjunctive tool to predict outcomes after endovascular aneurysm repair. [ABSTRACT FROM AUTHOR]

The DIRC-like time-of-flight detector (DTOF) at the Super Tau-Charm Facility (STCF) in China is a Cherenkov light detector that uses the TOF technique to identify charged particles. To achieve the expected target that provides a $3\sigma \pi $ /K separation at 2-Ge/c momentum, a single-photon time resolution of better than 50 ps is required, while the contribution from electronics should be lower than 15 ps. To meet the requirements with high channel count integration, the timing electronics using leading-edge discrimination and field-programmable gate array (FPGA)-based time-to-digital converters (TDCs) are employed in the DTOF detector. This article reports the results of the first phase of project where the timing electronics with 128 channels has been constructed and its performance has been evaluated. Including the uncertainty of system clock distribution and synchronization, the intrinsic timing resolution of the electronics is better than 10-ps rms. Taking fast microchannel plate photomultiplier tubes (MCP-PMTs) as Cherenkov photodetectors and adopting time-over-threshold (TOT) measurement for time walk correction, the measured single-photon time resolutions are better than 40-ps rms. The test results confirm that the proposed timing electronics has advantages of high precision and high integration, which is highly demanded in future picosecond timing detectors. [ABSTRACT FROM AUTHOR]

In the present paper, single-crystal PbMoO4 nanorods and nanowires were synthesized via a simple sonochemical process without any templates or surfactants for the first time. The samples were analyzed by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and electron diffraction (ED). Experimental results indicated that the obtained PbMoO4 nanowires were single-crystal in structure and the aspect ratio was about 200. The pH value and precursor were found to be critical factors to the controlled preparation of PbMoO4 nanorods and nanowires. The possible mechanism for the synthesis of PbMoO4 nanorods and nanowires was also discussed and other one-dimensional nanomaterials can also be successfully prepared by the present method. [ABSTRACT FROM AUTHOR]

BACKGROUND: Endovascular aortic aneurysm repair (EVAR) is currently established as the first-line treatment for anatomically suitable abdominal aortic aneurysm (AAA). OBJECTIVE: To establish a deep convolutional neural networks (DCNN) model for fully automatic segmentation intraluminal thrombosis (ILT) of abdominal aortic aneurysm (AAA) in pre-operative computed tomography angiography (CTA) images. METHODS: We retrospectively reviewed 340 patients of AAA with ILT at our single center. The software ITKSNAP was used to draw AAA and ILT region of interests (ROIs), respectively. Image preprocessing and DCNN model build using MATLAB. Randomly divided, 80% of patients was classified as training set, 20% of patients was classified as test set. Accuracy, intersection over union (IOU), Boundary F1 (BF) Score were used to evaluate the predictive effect of the model. RESULTS: By training in 34760–35652 CTA images (n = 204) and validation in 6968–7860 CTA images (n = 68), the DCNN model achieved encouraging predictive performance in test set (n = 68, 6898 slices): Global accuracy 0.9988 ± 5.7735E-05, mean accuracy 0.9546 ± 0.0054, ILT IOU 0.8650 ± 0.0033, aortic lumen IOU 0.8595 ± 0.0085, ILT weighted IOU 0.9976 ± 0.0001, mean IOU 0.9078 ± 0.0029, mean BF Score 0.9829 ± 0.0011. Our DCNN model achieved a mean IOU of more than 90.78% for segmentation of ILT and aortic lumen. It provides a mean relative volume difference between automatic segmentation and ground truth (P > 0.05). CONCLUSION: An end-to-end DCNN model could be used as an efficient and adjunctive tool for fully automatic segmentation of abdominal aortic thrombus in pre-operative CTA image. [ABSTRACT FROM AUTHOR]

Gradient nanostructured (GNS) metallic materials have the potential to solve the strength-ductility dilemma. In this work, we investigate the depth-dependent microstructures and mechanical properties of the fully austenitic GNS 310S stainless steel fabricated by an adaptive surface mechanical rolling treatment technique. It is of great significance to study the mechanism of gradient nanocrystallization (GNC) and strength-ductility synergy of fully austenitic GNS 310S under the condition that severe plastic deformation does not induce martensitic transformation. Microstructural observations showed that a fully austenitic GNS surface layer is formed at room temperature, with a grain size ranging from ~ 56 nm to tens of microns from surface to the core. The GNC of GNS 310S is dominated by dislocation activities, twins, and shear bands. GNS 310S exhibited excellent mechanical properties and achieved good strength-ductility synergy, which is attributed to a high gradient residual compressive stress and a thicker GNS surface layer. [ABSTRACT FROM AUTHOR]

In recent years, all-solid-state high-voltage pulse generators have been widely used in irreversible electroporation for tumor ablation technology. However, high voltage may cause the breakdown of loads that leads to short circuits. The short circuit of loads will generate high short-circuit currents that will affect the performance of semiconductor switches. To improve the reliability and lifetime of solid-state pulse generators, a passive synchronous isolated gate drive circuit with short-circuit protection based on decreasing the gate–source voltage is proposed in this article. To verify the overcurrent protection during the breakdown of loads, a solid-state Marx generator prototype using the drive circuit was built and tests were carried out. The experimental results show that the 205-A short-circuit current was clamped with 90 A in less than 500 ns, while the transient voltage can be neglected. Besides, the response time, the maximum transient voltage, and the maximum current amplitude can all be adjusted. [ABSTRACT FROM AUTHOR]

The precise forecasting of wind power output is crucial for the integration of large-scale renewable energy generation into the power grid. It plays a vital role in ensuring safe and stable operation of power grid, diminishing fuel consumption, and minimizing environmental impacts. This research presents a machine learning prediction model that integrates intelligent optimization algorithms and data decomposition techniques for short-term wind power output forecasting. The initial phase of this research develops a prediction model utilizing variational mode decomposition and long short-term memory networks. To mitigate the randomness and uncertainty of wind energy, and improve prediction accuracy, the butterfly optimization algorithm is introduced to optimize the parameters of variational mode decomposition and long short-term memory networks. Several in-depth case studies are carried out on the actual wind power generation dataset in mainland China to confirm the feasibility and effectiveness of the proposed hybrid model. Experimental results demonstrate that the proposed model outperforms the compared model in terms of prediction accuracy across different seasons, showing good practicality and generalizability. • A novel hybrid model is proposed for wind power prediction. • Employ the parameter-optimized variational mode decomposition to capture the features of wind farms. • Hyperparameter optimization of long short-term memory is proposed. • The experiment categorizes data by season to validate the performance and reliability of the model. [ABSTRACT FROM AUTHOR]

The constitutive relationship can effectively describe and predict the deformation behavior of materials, and it is critical to establish appropriate constitutive relationships to obtain the mechanical response of gradient nanostructured (GNS) metallic materials during deformation. In this work, a general method for establishing the multi-layer constitutive relationship of the GNS metallic materials was proposed. A fully austenitic 310S stainless steel specimen with a thickness of 1.4 mm was fabricated by surface mechanical rolling treatment (SMRT) technology, and its depth-dependent microstructures and macroscopic mechanical properties were experimentally investigated. Based on the experimental results of uniaxial tensile and microhardness, using the quantitative relationship between microhardness and flow stress, the reverse analysis was conducted using a separation parameter method to establish the constitutive relationship of the 28 thin shells of the GNS310S specimen. Finite element analysis (FEA) confirmed that GNS310S was in a multiaxial stress state at low strains, and the evolution of stress and strain gradients during non-uniform deformation was analyzed. The method for establishing the constitutive relationship is independent of the microstructure and synergistic strengthening factors, and the experiment performs conveniently and has great generalizability, which can provide a useful guide for the mechanical modeling of the GNS metallic materials to obtain the intrinsic mechanical response. • GNS310S stainless steel with a thicker GNS layer was fabricated using SMRT processing. • A general method for establishing the multi-layer constitutive relationship of GNS materials was proposed. • Constitutive relationships of 28 layers in GNS310S were established based on reverse analysis. • Stress and strain gradient evolution was studied numerically. [ABSTRACT FROM AUTHOR]

Hemolytic reactions can cause serious complications after administration of Intravenous Immunoglobulin (IVIG), due to passive transfer of anti-A and anti-B IgG antibodies (isoagglutinins). A maximum allowable amount of isoagglutinins is established in the US and EU for licensed IVIG, as measured by a specified direct hemagglutination test (DHAT). Despite this limit, reports of hemolysis have increased over time, raising the question of how well the DHAT predicts clinically significant hemolysis. This study was undertaken to develop a microplate-based complement-dependent hemolysis assay (CDHA) that reproducibly measures functional hemolytic activity of IVIG, for assessment of IVIG products. An IVIG working reference reagent (NIBSC 14/160) was qualified as an assay control and for quantitation purposes. Hemolytic activities of 36 IVIG product lots encompassing seven brands and including 6 clinically hemolytic lots were measured. Hemolytic activity varied among IVIG product brands, and to a lesser extent, from lot-to-lot for individual brands. Correlation between the CDHA and DHAT was not robust which may reflect imprecision of the DHAT method or additional variables that influence complement-dependent hemolysis after opsonization. In conclusion, the CDHA provides a simple, specific, and sensitive tool for IVIG product characterization and investigation of hemolytic events by manufacturers, researchers, and regulatory authorities. [ABSTRACT FROM AUTHOR]

Pea is an important grain and vegetable crop with a large genome of ~4.45 Gb. The softness of pod is key to the quality of pea, yet the genes controlling softness remain unknown. Here, the pod softness phenotype was visually scored at the fully mature stage, which suggested that this trait was a composite trait governed by two genes. Bulked segregant analysis sequencing (BSA‐Seq) using the soft‐ and hard‐podded pools from the F2 detected a strong peak of Δ (SNP‐index) on chromosome 1 and a weaker peak on chromosome 5. The former was designated as PsPS1. Fine mapping using the F2 delimited PsPS1 to a ~6 Mb genomic region. A set of interesting candidate genes including those encoding cell wall components were identified. Sequence variants analysis from a panel of pea accessions and qRT‐PCR in immature pods of the parents suggested Psat1g150000 encoding a pectate lyase superfamily protein as a candidate gene. The results solidify the basis for cloning of the gene determining pod softness and marker‐assisted selection for the trait improvement. [ABSTRACT FROM AUTHOR]

This article proposes a solid-state linear transformer driver (LTD) structure based on full-bridge bricks, which can not only generate bipolar pulses but also avoid the use of additional core reset circuits. The theoretical analysis and experimental results show that a reverse voltage overshoot will occur after each pulse ends if simultaneous conduction strategy is adopted. The phase shift strategy can provide a low-impedance circuit for the primary current to suppress reverse voltage overshoot. An experimental prototype with six modules is implemented. Each module consists of two full-bridge bricks. The prototype can generate bipolar high-voltage pulses with an amplitude of 0–4.2 kV, a pulsewidth of 100–500 ns, and a frequency of 0–10 kHz. The full-bridge LTD can drive the ozone generator with surface dielectric barrier discharge structure. [ABSTRACT FROM AUTHOR]

BACKGROUND: Scoliosis causes changes in the thorax, but it is unclear what type of changes occur in the thoracic profile after scoliosis surgery. OBJECTIVE: To investigate changes in rib cage deviation in the postoperative period after adolescent idiopathic scoliosis (AIS) surgery. METHODS: Forty-four patients with AIS with a main right thoracic curvature underwent posterior surgical fusion (PSF), and radiological parameters of the spine and thorax were evaluated. RESULTS: The correction rates of main thoracic curve (MT)-Cobb angle at immediate after surgery and postoperative follow-up (2 years) were 64% and 66%, respectively. At these two postoperative time points, the correction rates of height of thoracic vertebrae 1 to 12 (T1T12) were 10% and 12%; the correction rates of Rib-vertebra angle difference (RVAD) were 59% and 52%; the correction rates of Apical rib hump prominence (RH) were 58% and 76%; while the correction rates of Apical vertebral body-rib ratio (AVB-R) were 23% and 25%, respectively. Statistical analysis showed that all these radiological parameters at the two postoperative time points were significantly different from the preoperative values (p < 0.001). There were significant correlations between MT-Cobb angle and T1-T12 height (p < 0.001), RVAD (p < 0.001), RH (p < 0.001), and AVB-R (p < 0.001). CONCLUSIONS: Posterior spinal fusion appears to be effective at correcting scoliosis, and the correction of rib cage deviation also plays an important role. [ABSTRACT FROM AUTHOR]

Objective. This study was aimed at clarifying the application effect of silicone mattress combined with hydrocolloid dressing in ICU patients with liver failure. Methods. A total of 86 patients with liver failure admitted to the intensive care unit (ICU) of the Fifth Medical Center of Chinese PLA General Hospital from September 2018 to September 2020 were selected as the research subjects. Patients treated with conventional sponge mattress and routine nursing care were included in group A (n = 43), and those treated with silicone mattress combined with hydrocolloid dressing were included in group B (n = 43). The incidence of pressure ulcers and phlebitis, the scores of Visual Analogue Scale (VAS) and Pittsburgh Sleep Quality Index (PSQI), and the nursing satisfaction were observed and compared between the two groups. Results. The incidence of pressure ulcers in group B (6.98%) was lower than that in group A (25.58%). The incidence of phlebitis in group B was lower than that in group A (20.93% vs. 53.49%). The VAS score of group B was 2.16 ± 0.38 , which was lower than that of group A (4.86 ± 1.09). The PSQI score of group B was lower than that of group A (9.74 ± 2.76 vs. 14.84 ± 3.95). A higher nursing satisfaction was determined in group B compared with group A (93.02% vs. 76.74%). Conclusions. Silicone mattress combined with hydrocolloid dressing can reduce the incidence of pressure ulcers and phlebitis in ICU patients with liver failure, reduce complications, and improve nursing satisfaction, which is worthy of clinical promotion. [ABSTRACT FROM AUTHOR]

In this work, four slag samples were collected from the OMB CWS gasification, and the mineral behavior and morphology were studied to explore the formation mechanism of blockage slag. Results showed that amorphous phase is dominant in all slag samples, which was mainly glassy substances rich in low‐temperature eutectic of iron. The precipitation of metallic iron and the crystals of SiC, calcite, and quartz were found in slags which were taken from the bottom of the combustion chamber (S‐b). The quench slag collected from stable operation conditions (S‐s) had a low content of quartz crystalline. While slag from the down pipe of the quench chamber (S‐b) and bulk slag from the water‐cooled pool (S‐p) had observed the precipitation of crystals. Comparing to S‐s, carbon matters in S‐b had a higher order degree of carbon structure. By comparing the slag sample obtained during stable operation (S‐s) with slag blocking occurs (S‐b, S‐d, S‐p), it is found that the blockage of the OMB CWS gasifier was strongly related to unreacted residual carbon and the high content of sodium and iron in coal. They will interact with each other and form small number of crystals and most of the amorphous material. [ABSTRACT FROM AUTHOR]

This study focuses on analyzing the injury severity of crashes occurring at different times of the day and providing insights into crash prevention countermeasures. The data contained 1521 police-reported crashes that occurred on a mountainous expressway between 2012 and 2017, which were divided into two subsamples: the daytime crash sample and the nighttime crash sample. The statistical plausibility of developing separate models for the two subsamples was verified by the likelihood ratio test. Two random thresholds random parameters hierarchical ordered probit models were independently conducted to analyze the relationship between injury severity and risk factors. The results showed that the contributing factors to injury severity were different between the two subsamples. The three factors most likely to cause serious crashes during the daytime were 'not keep a safe distance', 'drunk driving' and 'adverse weather', while during the nighttime, these three factors were 'fatigued driving', 'adverse weather' and 'drunk driving'. The same factors can cause more serious consequences during the nighttime than that during the daytime. After fully identifying the contributing factors related to injury severity, and in particular distinguishing the features of daytime and nighttime crashes, some useful suggestions were proposed to mitigate crash injury severity. [ABSTRACT FROM AUTHOR]

This article puts forward a high repetition rate and high-voltage resonant pulse generator for plasma-assisted milling. This circuit uses only one semiconductor switch with an antiparallel diode and works in the resonant mode with the help of a resonant inductor, a resonant capacitor, and a pulse transformer to generate high-voltage pulses. An equivalent circuit of the proposed topology considering parasitic elements is established. Based on the equivalent circuit, the working principle of the pulse generator is analyzed in detail. In order to verify the theoretical analysis and circuit operation, a laboratory prototype with a 150-V dc input is implemented. The pulse repetition rate can be adjusted from 5.32 to 18.90 kHz, and the peak output voltage correspondingly varies between 8.84 and 11.7 kV. The pulse generator is used to drive a dielectric barrier discharge plasma-assisted milling chamber. Experimental results show that the pulse generator can work stably. [ABSTRACT FROM AUTHOR]

BACKGROUND: Lumbar X-rays are usually preferred in patients with lower back pain, but lumbar spinal stenosis (LSS) cannot be directly observed on lumbar X-ray films. OBJECTIVE: The purpose of this study is to explore the correlation between the degree of single-segment central LSS and lumbar X-ray measurements. METHODS: The data of 60 male patients aged 39–78 years with single-segment central LSS were analyzed. Linear correlation analysis was used to determine the correlation between the single-segment central LSS and the various measurement parameters. Multiple linear regression analysis was used to analyze the factors affecting single-segment central LSS. RESULTS: There were significant differences in S 1 /S 0 , E, B, L 1 - 5 Cobb, and M among the three groups (p < 0.05). S 1 /S 0 was positively correlated with E, B, L 1 - 5 Cobb, and M (p < 0.05), but was not correlated with D (p = 0.66). After multiple linear regression analysis, B, L 1 - 5 Cobb, and M were independently associated with S 1 /S 0. CONCLUSIONS: The B, L 1 - 5 Cobb, and M parameters were independently associated with single-stage central LSS, and would likely be of particular value in evaluating the degree of single-segment central LSS; B, L 1 - 5 Cobb, and M served as independent predictors of the degree of LSS. These findings will guide clinicians' decision-making in the future. [ABSTRACT FROM AUTHOR]

In large-scale physics experiments, there is a trend to implement clock distribution and synchronization over multi-Gigabit serial links on optical networks. The accuracy of clock synchronization in such a fashion is mainly determined by two aspects: one is the stability of the clock distribution over the links, and the other is the employed mechanism of clock synchronization. To achieve a high synchronization accuracy in a range of tens of picoseconds, this article proposes a new optical fiber link and synchronization scheme based on optical circulators and serial transceivers embedded in field-programmable gate arrays (FPGAs). Benefiting from the single wavelength fiber connection, high-precision time-to-digital converters (TDCs) and phase interpolator (PI) sub-block in state-of-the-art Serializer–Deserializer (SerDes) transceivers on FPGAs, the offset of distributed clocks can be measured on-line and precisely compensated. The time synchronization performance is evaluated on a prototype system with three levels of structure. Through multiple power or reset cycles and long-term operation tests, the clock synchronization accuracy over a 5-km fiber connection is measured to be lower than 15 ps, and the recovered clocks at nodes at different levels have independent jitter, all lower than 4.2 ps. In addition, the achieved high performance is also proved to be insensitive to operating temperature and the connection distance. [ABSTRACT FROM AUTHOR]

In picosecond timing detectors, the time over threshold (TOT) of detector signals is normally required to be measured to enhance the front-edge timing precision. The extremely narrow pulsewidth of these detector signals has posed challenges to the design of time-to-digital converters (TDCs) based on field programmable gate arrays (FPGAs) for TOT measurement. In this article, an FPGA-based tapped-delay-line (TDL)-type TDC is proposed to simultaneously measure the arrival time and TOT time of nuclear pulses. By propagating the hit signal along a single TDL, the proposed bubble-proof encoding scheme can extract the time information of two transitions of hit signal in one measurement. The minimum measurable TOT time is proved to be limited only by the electrical characteristics of low-voltage differential signaling (LVDS) receivers of FPGAs. Through the performance evaluation on the prototype with a Virtex Ultrascale + FPGA, where the minimum measurable TOT time can be as low as 370 ps, the rms precision reaches 3.0 ps for TOT time measurement. Given the pulsewidths ranging from 0.4 to 1.5 ns, the measured TOT time is highly consistent with the direct readout values from the oscilloscope in a wide temperature range. To apply the TDC into a microchannel plate photomultiplier tube (MCP-PMT)-based timing detector, the front-end electronics board with a dual-threshold TOT measurement is constructed. The joint beam test results show that the coincidence time resolution of two identical detector channels can be improved from 36.5 to 10.3 ps, which demonstrates the significance of TOT measurement to modern picosecond timing detectors. [ABSTRACT FROM AUTHOR]

Water-based lubricant is regarded as an important substitute for the oil-based lubricant when used in improving the tribological properties. Additives are urgent required in water-based lubricants as their disadvantages of poor lubricating properties. In the present work, a new additive containing S, P, Cl active element was synthesized, and the tribological properties were evaluated by using a four-ball tester. The impact of temperature on the tribological properties of water-soluble lubricant was also studied. The worn surfaces were analyzed by X-ray absorption near-edge structure (XANES) spectroscopy. The results show that the synthesized additive exhibit better tribological properties than oleate solution at higher load. XANES spectroscopy indicates that the compositions of tribofilms changed with the temperature. The different composition of the tribofilm has a great influence on tribological behavior. [ABSTRACT FROM AUTHOR]

Four hundred fifty four pyrosequencing was used to analyze the microbial community and diversity of oily farmland soil from Fushun, Liaoning Province, China. The results showed that a total of 114 Phyla, 262 Classes, 430 Orders, 685 Families, 869 Genera, and 294 Species were detected and summarized in the soil microbe. The petroleum hydrocarbons significantly changed the structure and diversity of soil microbial communities. Proteobacteria, Bacteroidetes, Actinobacteria, Acidobacteria, Gemmatimonadetes, Nitrospirae, Firmicutes, Verrucomicrobia, Elusimicrobia became the dominant flora in oil-contaminated areas. And the changes in the main bacterial flora in the soil were highly correlated with soil TPH (total petroleum hydrocarbon), pH and SOM (soil organic matter). The prediction of community metabolism function exhibited that 8 KEGG pathways were significantly enriched in petroleum contaminated soil, and the abundance of Proteobacteria, Moraxellaceae, Enterobacteriales and Sphingobacteriales significantly decreased under the stress of oil pollution. This research provided a theoretical and technical basis for the development and application of functional strains in the future. [ABSTRACT FROM AUTHOR]

Camera-based Experimental Modal Analysis (EMA) is able to measure full-field vibration modes contactlessly. However, camera measurements still suffer from a lower sampling frequency and lower Signal-to-Noise Ratio (SNR) compared to accelerometers and laser vibrometers. Since regular sampling confines the results to the Nyquist frequency (i.e. , half the frame rate of a camera), in a previous paper we have proposed an approach that exploits images randomly sampled in time, allowing to measure modes beyond the Nyquist frequency. In this paper we employ such an approach and we propose a novel excitation scheme to increase the SNR, i.e. , the specimen under investigation is excited at selected resonance frequencies, which results in high amplitudes of the structural responses. These frequencies are measured by accelerometers during a pre-test, and a multi-sine signal containing these frequency components is generated as structural excitation through a shaker. Furthermore, as Rigid Body Motion (RBM) due to pseudo-free suspension is not desired for EMA, in this paper we also propose a novel optimization workflow for RBM compensation. The accuracy of the proposed approach with multi-sine excitation is first evaluated numerically by reconstructing steady-state response signals. Secondly, the whole workflow (i.e. , multi-sine excitation and RBM compensation) is validated on an experimental case with a 3D component and a stereo camera setup. From a sequence of randomly sampled images equivalent to a frame rate below 50 fps (corresponding to an equivalent Nyquist frequency below 25 Hz), four modes up to 250 Hz (i.e. , ten times higher than the Nyquist frequency) are extracted, which correlate well with the modes predicted through a finite element simulation. • We propose a multi-sine excitation method to improve SNR in the camera-based EMA. • The excitation contains the resonance frequencies of the specimen. • We propose a two-step approach to compensate for rigid body motion. • We adopt a random sampling scheme to go beyond the Nyquist frequency. • We obtain 3D spatially dense vibration mode shapes with a fast measurement campaign. [ABSTRACT FROM AUTHOR]

• The fictitious crack growth length of RCC is determined considering the relative ligament depth. • A model is proposed to describe the dispersion of the RCC material parameters. • The fracture failure behavior and structural peak load of RCC are predicted. • The relationship between a laboratory sample and an RCC dam is studied numerically. Roller-compacted concrete (RCC) is widely used in dam structures; the fracture properties of RCC directly affect the cracking resistance of RCC dams. Solving the discrete problem of the RCC fracture properties and obtaining real material parameters is important for the healthy and stable operation of RCC structures. The tensile strength (f t) and fracture toughness (K IC) are two critical parameters that have a direct impact on the fracture properties of RCC structures. In this study, the relative ligament depth [(W − a 0)/ d i ] is associated with the fictitious crack growth length (Δ a fic). A normal statistical fracture model is developed to describe the dispersion of the RCC f t and K IC to obtain the real material parameters of RCC with different cement-to-aggregate (C/A) ratios. For an increase in the C/A ratio from 12 % to 17 %, the f t and K IC for each group of RCC structures are 4.05–6.35 MPa and 0.90–1.41 MPa·m1/2, respectively. Based on the results of the normal statistical analysis, fracture failure curves are constructed with 95 % reliability, revealing that the fracture behavior of RCC is quasi-brittle fracture. Additionally, a relationship between the peak load (P max) and the material parameters is proposed, this confirms the correctness of the proposed model. Finally, the relationship between indoor small-size specimens and actual engineering-scale RCC dams regarding fracture failure is discussed based on the fracture failure curve. [ABSTRACT FROM AUTHOR]

Objective: The objective was to investigate the law of three-dimensional thermal field radiation of ceramic slot microwave (CSMW) ablation antenna.Materials and Methods: First, microwave ablation experiments were performed with phantom and temperature data were collected. Second, the specific absorption rate distribution function of microwave (MW) ablation antenna was fit. Third, the MW ablation thermal field morphology was simulated based on the rapid simulation method. In addition, to determine the thermal field simulation accuracy, comparative analysis on the ablation morphology of forty clinical patients with liver cancer receiving percutaneous treatment was conducted.Results: Regarding the ablation morphology, the CSMW ablation antenna had greater long and transverse diameters and ablation volume than the polytetrafluoroethylene slot microwave (PSMW) ablation antenna (P < 0.05). Compared with the actual ablation morphology in clinical practice, the error rate in long and transverse diameters of the simulated morphology of thermal field was up to 5% and the minimum was 1.2%, whereas the maximum volume error rate was up to 9.8%.Conclusion: The CSMW ablation antenna had a greater long diameter, transverse diameter, and volume regarding the ablation morphology than the PSMW ablation antenna, and the thermal field morphology obtained based on the rapid simulation algorithm had a high accuracy. [ABSTRACT FROM AUTHOR]

Key message: An effective and stable quantitative resistance locus, QSc.VR4, was fine mapped, characterized and physically anchored to the short arm of 4H, conferring adult plant resistance to the fungus Rhynchosporium commune in barley. Scald caused by Rhynchosporium commune is one of the most destructive barley diseases worldwide. Accumulation of adult plant resistance (APR) governed by multiple resistance alleles is predicted to be effective and long-lasting against a broad spectrum of pathotypes. However, the molecular mechanisms that control APR remain poorly understood. Here, quantitative trait loci (QTL) analysis of APR and fine mapping were performed on five barley populations derived from a common parent Vlamingh, which expresses APR to scald. Two QTLs, designated QSc.VR4 and QSc.BR7, were detected from a cross between Vlamingh and Buloke. Our data confirmed that QSc.VR4 is an effective and stable APR locus, residing on the short arm of chromosome 4H, and QSc.BR7 derived from Buloke may be an allele of reported Rrs2. High-resolution fine mapping revealed that QSc.VR4 is located in a 0.38 Mb genomic region between InDel markers 4H2282169 and 4H2665106. The gene annotation analysis and sequence comparison suggested that a gene cluster containing two adjacent multigene families encoding leucine-rich repeat receptor kinase-like proteins (LRR-RLKs) and germin-like proteins (GLPs), respectively, is likely contributing to scald resistance. Adult plant resistance (APR) governed by QSc.VR4 may confer partial levels of resistance to the fungus Rhynchosporium commune and, furthermore, be an important resource for gene pyramiding that may contribute broad-based and more durable resistance. [ABSTRACT FROM AUTHOR]

We report for the first time the discovery of reversible n–p conduction type switching in a chalcogenide, NaCu5S3, without structural transition. AC impedance and first-principles simulations of the ionic migration confirmed the local melting trends of the hexagonal copper lattice at high temperatures, which could result in superionic conductivity within NaCu5S3. [ABSTRACT FROM AUTHOR]

The effect of amine on the tribological properties and hydrolytic stability of borate ester additives was examined by adding different kinds and quantities of amines into borate esters, which formed boron–nitrogen (BN) coordination complex or BN ammonium complex. The results showed that all BN complexes obviously improved the hydrolytic stability of borate ester, and most of them promoted load-carrying abilities, friction-reducing and anti-wear properties. By comparison, BN extra-coordination complexes presented a little stronger hydrolytic stability and tribological properties than BN ammonium complexes. Generally, the hydrolytic stability and tribological properties of BN complexes is promoted with the extension of carbon chain of the added amine. The worn surface analyses revealed B2O3 deposits and adsorbed B- and N-containing organic compounds were responsible for the resulted tribological properties. Our results would provide some guidance to practical application of borate ester additives in lubricants. [ABSTRACT FROM AUTHOR]

Background: Scoliosis causes thoracic deformities, and it is necessary to assess these changes in pulmonary function test (PFT). To determine how measurements of spinal and thoracic cage deformities are related to pulmonary function. Methods: Seventy-two patients with main right thoracic curvature in adolescent idiopathic scoliosis (AIS) underwent a PFT and a radiological parameter evaluation of spinal and thoracic cage deformities. Simple and multiple linear regressions were also used to note whether a combination of variables might better predict PFT values. Means were compared using the two-sample t test or one-way ANOVA with Tukey's multiple comparison methods. Results: Forced vital capacity (FVC)% predicted had significantly negative correlations with main thoracic curve Cobb (MT-Cobb) (R2 = 0.648, p < 0.001), main thoracic curve-rib hump (MT-RH) (R2 = 0.522, p < 0.001), main thoracic curve apical vertebral body-to-rib ratio (MT-AVB-R) (R2 = 0.536, p < 0.001), and main thoracic curve apical vertebra translation (MT-AVT) (R2 = 0.383, p < 0.001). Multiple regression analysis was performed with FVC% predicted as the dependent variable and MT-Cobb, MT-RH, MT-AVB-R, and MT-AVT as the independent variables. MT-Cobb, MT-RH, MT-AVB-R, and MT-AVT were factors with a significant effect on FVC% predicted (p < 0.001). For 45 patients who had preoperative FVC impairment (FVC% predicted < 80%), their MT-Cobb averaged 76.71°. Twenty-seven patients with normal preoperative FVC (FVC% predicted ≥ 80%) had a smaller mean MT-Cobb of 52.03° (p < 0.001). In other radiological parameters, the impaired FVC group had a MT-AVT of 54.29 mm compared to 38.06 mm for the normal FVC group (p < 0.001). MT-AVB-R averaged 2.92 for the impaired FVC group and 1.78 for the normal FVC group (p < 0.001). MT-RH averaged 28.79 mm for the impaired group and 16.62 mm for the normal group (p < 0.001). Further stratification of preoperative PFT results is divided into three groups. The three groups also showed significant differences in MT-Cobb, MT-RH, MT-AVB-R, and MT-AVT (p < 0.001). Conclusion: Severe scoliosis leads to an increased degree of thoracic deformity, which increases the risk of lung damage in AIS. Moreover, a more accurate assessment of pulmonary function is achieved through radiological parameters and PFTs. [ABSTRACT FROM AUTHOR]

Silicon photomultiplier (SiPM) arrays normally contain tens of photon detection channels, with each channel consisting of several thousand microcells and each microcell being a normal single-photon avalanche diode with a quenching resistor. The dark counts of SiPM arrays have independent spatial and temporal randomness, which will be used for true random number generation in this paper. Since the arrival times of the high dark count rate in each channel are measured with a fast, high precision time-to-digital converter, along with the number of channels, the entropy can be extracted with very high efficiency. The bias in the raw data due to the exponential distribution of the arrival time differences between successive dark counts is removed using the transformation of the cumulative distribution function. Except for the preamplifiers for a signal readout from a 4-channel SiPM, all electronics components in our prototype are implemented inside of one chip of a field programmable gate array. The prototype has a 63.54 Mbps generation throughput, and the statistical quality of the generated random numbers is evaluated. Since the property of the dark count is compatible with single-photons from laser beams, one can easily increase the generation bitrate by either adding more SiPM channels or irradiating the SiPM with extra laser beams. [ABSTRACT FROM AUTHOR]

Li 1.2 Ni 0.2–x Mn 0.6–x Al 2x O 2 (x = 0, 0.01, 0.02, 0.03) electrode materials with hierarchical micro−nanostructures are synthesized via a porous polypropylene (PP) membrane as hard template. The physical and electrochemical measurements of the samples are systematically investigated to reveal the effects of the Al3+–doping on the electrochemical properties and physical characteristics. The test results show that the Li 1.2 Ni 0.18 Mn 0.58 Al 0.04 O 2 (x = 0.02) sample delivers the highest specific charge/discharge capacities and an improved rate capabilities for the enhanced the structure stability, reduced the charge transfer resistance and improved the diffusion coefficient of lithium ions. Hierarchical micro−nanostructured Li 1.2 Ni 0.2–x Mn 0.6–x Al 2x O 2 (x = 0, 0.01, 0.02, 0.03) electrode materials with sheet−like structures are synthesized via a porous polypropylene membrane as hard template. The effects of morphology characteristics and doping amount of Al3+ on the electrochemical properties and physical characteristics of the samples (e.g., phase composition, element composition and valence states, electrode reaction kinetics, charge/discharge capacities, cycling life, rate capability) are measured systematically in this work. The doping of Al3+ does not change the crystal structure of the Li 1.2 Ni 0.2 Mn 0.6 O 2 material, and the Li 1.2 Ni 0.18 Mn 0.58 Al 0.04 O 2 (x = 0.02) sample delivers the high specific charge/discharge capacities and the improved rate capabilities. Simultaneously, this method is suitable to synthesize other multi–component electrode materials with porous sheet–like structures. Unlabelled Image [ABSTRACT FROM AUTHOR]

In a field-programmable gate array (FPGA)-based time-to-digital converter (TDC), the hit signal to be measured launches out a segment of the clock-like signal propagating along the tapped delay line (TDL). If every edge of the clock-like signal in the TDL status is identified by the encoder, parallel multiple measurements can be achieved to improve the TDC time precision. In this article, we propose a bubble-proof multi-edge encoding scheme by hardware in pipeline fashion, which can achieve 277-MSamples/s measurement throughput on a Kintex-7 FPGA. Based on the encoding scheme, TDCs with 1-, 2-, 4-, 6-, and 8-edge multiple measurements are sequentially implemented. The corresponding average rms precisions measuring time intervals from 0 to 50 ns are evaluated as 8.2, 4.8, 3.5, 3.1, and 3.0 ps, respectively. The test results confirm that the proposed TDC with a multi-edge encoding scheme can effectively improve TDC time precision without adding TDC measurement dead time. Its resource-saving feature also makes it feasible for multi-channel TDC integration. [ABSTRACT FROM AUTHOR]

• Focus on road crashes involving trucks on mountain expressways in China. • Road curves should have radius between 1000 and 2000 m. • The longitudinal gradient should be between 1 and 3% • Measures should discourage driver aberrant behaviour. • Measures should disincentivate the overloading of trucks. The fast economic growth in China has dramatically increased the number of heavy traffic and the length of the expressway network, with consequent road safety issues emerging in particular in mountainous expressways. This study positions itself at the intersection of these issues by analysis determinants of injury severity for truck crashes on mountainous expressways in China. A sample of 2695 heavy truck crashes occurring on four mountain expressways in Jiangxi and Shaanxi (China) between 2006 and 2015 was analysed to uncover the effect on crash injury severity of geometric, driver, crash, truck and environmental characteristics. Given that the expansion of the expressway network is underway, model findings focused on the effect of geometric characteristics and suggested that road design should have curves that are neither too sharp nor too long, as well as longitudinal gradients not too steep. Also, model findings indicated a need for the toughening of deterrence measures and the bolstering of police enforcement with respect to aberrant driver behaviour (e.g., driving without a valid license, without seat belts, or while intoxicated) and most relevantly overloading of the trucks. [ABSTRACT FROM AUTHOR]

• Laser and photochemistry were first used in restoring and transformation of PbS on painted cultural relics. • Targeted fast realization of restoring and transformation of PbS, and without damage to the base color. • Laser catalysis restoration has wide applicability to papers, the silks and other organic materials. Lead white darkening is a common disease in all kinds of painted cultural relics. In this study, a combination of laser and photodynamic technology was used to achieve controlled restoration of lead sulfide at the lead darkening site on the painted layer of cultural relics by laser catalysis with porphyrin to produce singlet oxygen. The chromatic change, micromorphology and chemical composition were systematically studied for a simulated sample with the lead darkening part of the painted layer. The results show that laser catalytic treatment can repair the color darkening that occurs by the PbS formation, while no obvious changes to the pore and microparticle structure of the painted layer and the base. In this study, the pollutant of lead sulfide was proved to be converted into lead sulfate by oxidation, and then was converted to lead white by precipitation, which was the original composition of the pigment. It is also found that the laser catalytic treatment method can effectively avoid basic layer damages of cultural relics, especially for the papers, the silks and other organic materials. This technology not only provides a new approach for the restoration and transformation of PbS on painted cultural relics, but also makes available new applications for the laser and photodynamic technology in the field of cultural relics protection. [ABSTRACT FROM AUTHOR]

To realize the high‐efficiency utilization of iron‐rich coal (ZC), it is necessary to conduct in‐depth research on its ash fusion characteristics and regulation mechanism. In this paper, the fusion temperature test of ZC coal ash was first carried out in a weak reducing atmosphere, and diatomite (GZT) and Naomaohu high‐calcium coal (NMH) were selected as additives. The results show that the four characteristic temperatures of ZC coal ash are all low under weak reducing conditions. The addition of NMH ash lowered the fusion temperature of ZC coal ash, while the GZT ash increased the fusion temperature to varying degrees. When the addition ratio of NMH ash is less than 40 %, the effect of increasing the difference between the deformation temperature and flow temperature of ZC coal ash is still positive. The addition of NMH ash made the slag system generate a high content of calcium‐magnesium feldspar and calcium‐iron feldspar, decreasing the fusion temperature of the blended coal ash. The addition of GZT ash increased the content of SiO2 in the slag system and promoted the increase of the iron‐pyroxene content, and the formation of the iron‐aluminum pyroxene and cordierite mineral phases, thereby increasing the coal ash fusion temperature. [ABSTRACT FROM AUTHOR]

Unlike the solid dense medium, the low-porosity metals exhibit many unique dynamic behaviors. These properties have been investigated in this work for aluminum with a porosity of 3.3% under high velocity and planar plate impact. A push-pull-type velocity interferometer system for any reflector was used to measure the rear free surface velocity profiles of the samples. Time-resolved dynamic compaction and tensile fracture properties are presented. Results demonstrated that there are three distinct shock compressive waves in succession, including elastic wave, compaction wave, and stable shock wave. The dynamic tensile fracture occurs after the porosity being fully compacted and the stable shock wave being formed. With the increase of impact velocity, the dynamic tensile strength becomes higher and the spalled layer becomes thicker. Nevertheless, the dynamic tensile strength of the shock compacted aluminum is apparently lower than that of the solid dense aluminum, and is approaching that of the aluminum alloy 6061-T6. Physical explanations are illustrated and discussed. [ABSTRACT FROM AUTHOR]

An approach is developed to investigate the dynamic tensile fracture of nanocrystalline copper by laser irradiation loading. A push-pull type velocity interferometer system for any reflector is used to measure the rear free surface velocity profiles. The dynamic tensile strength of nanocrystalline copper films is determined from these velocity profiles as a function of the tensile strain rate. Results show that the dynamic tensile strength of nanocrystalline copper film is about 3 GPa, which is much higher than that of polycrystalline bulk copper, but lower than that of single crystal copper. This dynamic tensile strength increase may be attributed to constraints on dislocation motion by more grain boundaries in nanocrystalline materials. [ABSTRACT FROM AUTHOR]

Vanadium-based alloys are promising hydrogen storage materials which reversibly absorb hydrogen > 2.0 wt% under ambient conditions. In present study, we systematically investigated the V-Ti-Cr-Fe quaternary alloys with V concentration of 65–80 at% and discussed the relationship between hydrogen sorption properties and lattice parameter (a) and valence electron density (e/a). When 3.023 ≤ a ≤ 3.031 Å and e/a ≤ 5.12, the alloys show the hydrogen desorption amount ≥ 2.30 wt% and desorption plateau pressure ≥ 0.1 MPa at 298 K. More interestingly, compared to the Fe-free V 75 -Ti-Cr (Ti/Cr = 0.9) alloy, addition of 1–3 at% Fe could improve the hydrogen desorption amount and plateau pressure. The optimized alloy, V 75 -Ti-Cr-Fe 2 (Ti/Cr = 0.9), shows a reversible hydrogen capacity of 2.46 wt% at 298 K in the 1st cycle and the capacity retention rate of 96 % after 100 cycles. • Presence of 1–3 at% Fe improves hydrogen desorption properties of BCC alloys. • V 75 -Ti-Cr-Fe 2 shows a high desorption capacity of 2.46 wt% at 298 K. • V-Ti-Cr-Fe alloy exhibits the capacity retention rate of 96 % after 100 cycles. • Appropriate range of lattice parameter and valence electron density are determined. [ABSTRACT FROM AUTHOR]

To explore the effect of n-heptane soluble (HS) content in refined coal tar pitch (RCTP) on the preparation of needle coke (NC), a series of RCTP with different HS content were prepared by the solvent method. The RCTPs were reacted at 490 °C and 0.2 MPa for 6 h to obtain green cokes (GCs), and the GCs were calcined at 1400 °C to obtain NCs. The properties of RCTPs were studied by Fourier transform infrared (FTIR) spectroscopy, 1H nuclear magnetic resonance spectrum (1H NMR), and thermogravimetric (TG) analyses. The appearance and polarized microstructure of the GCs, and the Scanning electron microscope (SEM) image, X-ray diffraction (XRD) spectroscopy, Raman spectroscopy, linear expansion coefficient, and true density of the NCs were obtained and analyzed. The results show that with the decrease of HS content, the aromaticity of RCTPs increases, and the amount and length of branched chains decrease. Mesophase structures in GCs formed by these RCTPs have different types and orientations, which leads to obvious quality differences in NCs. The NC prepared from RCTP with HS content of 15.9% (RCTP-4) has the lowest linear expansion coefficient of 0.991 × 10−6 /°C, the highest true density of 2.1195 g/cm3, better fiber structure and carbon microcrystalline structure. Therefore, the HS content should be controlled not less than 15.9%, and the TI content should not be higher than 12.6% when RCTP was prepared by solvent method. [Display omitted] • The aromaticity index of I ar increased with the decrease of HS content. • Appropriate reduction of HS content is beneficial to improve the quality of needle coke. • The optimum group composition distribution of refined coal tar pitch was confirmed. [ABSTRACT FROM AUTHOR]

• The period from the first last train departure to network service ending is studied. • An optimization model is proposed to reschedule the train timetable of the network. • Total transfer waiting time and robustness of the optimization scheme is considered. • An improved quantum-behaved particle swarm optimization (QPSO) algorithm is designed. • Shenzhen metro network is used to verify model's effectiveness and practicality. Non-last train passengers in the last train period experience issues with transferability and accessibility in addition to the final service of each line. Therefore, a specified schedule needs to be determined by operators with full consideration of passengers' travel demand for all the trains during this period. Aiming at minimizing the average transfer waiting time, failure transfer rate, and the negative effect of random passenger flow without incurring excessive costs to the operator, a model optimizing the train connection in the last train period is formulated under constraints of operation parameters and transfer passenger flow conditions. To depict the uncertain features of transfer demand, a random passenger flow generation method with stochastic simulation is incorporated into an improved quantum particle swarm algorithm (QPSA). Taking Shenzhen Metro network in 2019 as an example, the rationality of the optimized model, the feasibility of the quantum-behaved particle swarm optimization (QPSO) model, and its superiority over the conventional particle swarm optimization (PSO) model in solving this problem are successfully verified. The results show an 18.54% decrease in the average waiting time for transfer passengers with the optimized last train connections, along with an increase of 8.31% and 6.54% in the number of successful transfer passengers and directions, respectively, after optimization. The proposed QPSO model can reach convergence faster and without falling into local optima. The results also show that the average waiting time of transfer passengers can be significantly decreased after fine-tuning train operation parameters. A reasonable combination of objective weight factors (λ = 10 , μ = 100) can reflect the game characteristics between passenger's and operator's preferences, while extending the service closure time within 20 min can further improve the overall service quality of last train period across the network. [ABSTRACT FROM AUTHOR]