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Low-energy electron collisions with normal-pentane (n-C5H12) that initiate the plasma to assist combustion are critical in understanding the underlying physics and chemistries. In the present work, we studied this collisional process using the R-matrix method at the static-exchange plus polarization and close-coupling model levels. The scattering calculation was performed by running the UKRmol+ code using the Quantemol Electron Collision interface to obtain elastic differential, momentum transfer, integral, and electronic excitation cross sections up to 20 eV and ionization cross sections up to 1000 eV. Our computed cross-section data are in better agreement with the available experimental results both regarding the magnitude and shape. We also demonstrated the importance of using a diffuse basis set in describing the scattering due to the Rydberg nature of the lowest unoccupied molecular orbitals of n-C5H12.

Moisture condensation often occurs in the cave wall in service, which results in the deterioration of the internal environment of the cavern and the decline of its functionality and durability. In this paper, the corrosion mechanism of concrete structure caused by the dew-condensation inside the cavern wall is analyzed, the daily temperature and humidity environment change inside and outside the cavern is measured, the influence of wind speed and ventilation condition on the dew-condensation inside the cavern is discussed, and the change rule of the external atmosphere temperature, the air temperature and humidity inside the cavern wall temperature is discussed. The results show that it is an inevitable physical phenomenon that the internal temperature of the cavern is lower than the dew point temperature, and the measures to deal with cold condensation such as sealing the cave with dry gas when no one is around, filling the cavern with air of appropriate temperature and humidity when there are people, and setting up dehumidification system are effective ways to improve the durability of the concrete structure of the cavern.

The charge carrier concentration profile is a critical factor that determines semiconducting material properties and device performance. Dielectric force microscopy (DFM) has been previously developed to map charge carrier concentrations with nanometer-scale spatial resolution. However, it is challenging to quantitatively obtain the charge carrier concentration, since the dielectric force is also affected by the mobility. Here, we quantitative measured the charge carrier concentration at the saturation mobility regime via the rectification effect-dependent gating ratio of DFM. By measuring a series of n-type GaAs and GaN thin films with mobility in the saturation regime, we confirmed the decreased DFM-measured gating ratio with increasing electron concentration. Combined with numerical simulation to calibrate the tip–sample geometry-induced systematic error, the quantitative correlation between the DFM-measured gating ratio and the electron concentration has been established, where the extracted electron concentration presents high accuracy in the range of 4 × 1016 – 1 × 1018 cm−3. We expect the quantitative DFM to find broad applications in characterizing the charge carrier transport properties of various semiconducting materials and devices.

To solve the disadvantages of traditional processing tooling, such as long processing cycle, low production efficiency, and easy deformation during the processing of large-size composite wing beams, a drilling and milling tooling for flexible positioning of composite wing beams of multiple types of aircraft is proposed based on the structural characteristics and manufacturing technology requirements of a certain type of aircraft wing spar combined with flexible tooling design technology. And a modular mobile clamping unit with automatic control is designed. Then the practical problems such as the difficult clamping and positioning of large-size wing beams, the deformation and vibration during processing are solved by the flexible drilling and milling tool. The results of the current design are helpful to improve the processing efficiency and shorten the manufacturing period of the wing beams.

To assess hadronic and electromagnetic components from extensive air shower events (EAS), 16 6Li-based ZnS (Ag) scintillator detectors combine into a thermal neutron detector array. After a shower event, each scintillator screen can concurrently catch neutrons and electrons, producing a succession of electrical signals with different pulse shapes. These signals are sampled by 16 oscilloscope-like circuits and sent over a single serial link, where EAS-related sampling results may fill each channel's memory. However, there are presently no specific studies to address data congestion in such random signal digitizers. Here, we demonstrate that decreasing the sampling rate on the trailing edge can compress data size while preserving pulse shapes and that optimizing the read/write time of memories can enhance transmission speed between asynchronous clock domains. According to test results, the 100 MHz serial transceiver can send 1996 pulses per second when only receiving data from one channel at 50 MHz rates, and it can send 242 pulses per second when simultaneously receiving data from 32 channels (16 × 2). This method increases transmitting speeds 2.3 times over previously employed algorithms, and the compressed rate reaches 97.74%. In addition, we found that the total error rate is lower than 10–10. Our findings also show how memory controllers would probably operate in data flows of 32 channels, predicting the slower writing time and the faster reading time that can complete sending a packet of one channel in the shortest time. We anticipate that our assay can help more detector arrays that require waveform transmission.

The effect of low-pressure carburizing (LPC) on the mechanical properties of open cellular structures was studied by taking the 316L stainless steel body-centred cubic (BCC) lattice fabricated by selective laser melting (SLM) as an example. The mechanical properties of the corresponding solid material and the microstructure of the carburized layer were also analyzed. The results showed that the depth of the carburized layer was about 450μm, composed of three sub-layers. After carburized, the yield strength of the 316L solid was obviously decreased accompanied by the reduced elongation at break. The embrittlement was also reflected in the carburized lattice so that the fracture occurred and the energy absorption capacity weakened. Simultaneously, the compressive proof strength of the lattice was improved after low-pressure carburizing due to the toughness inherent in the structure.

The present work investigates the kinetics of catalytic ammonia synthesis in a N2/H2 mixture activated by a nanosecond pulsed discharge plasma experimentally and numerically. X-ray diffraction, high-resolution transmission electron microscopy and x-ray photoelectron spectroscopy are combined to characterize the morphology and surface electronic properties of the catalyst. Special attention is placed on the role of excited species in promoting the formation of important intermediates and the plasma-enhanced surface chemistry. A detailed kinetic mechanism consisting of atoms, radicals, excited species, molecules, ions, and surface species is developed and studied by incorporating a set of the electron impact reactions, reactions involving excited species, ionic reactions, direct and dissociative adsorption reactions, and surface reactions. A zero-dimensional model incorporating the plasma kinetics solver is used to calculate the temporal evolution of species densities in a N2/H2 plasma catalysis system. The results show that the coupling of Fe/γ–Al2O3 catalyst with plasma is much more effective in ammonia synthesis than the Fe/γ–Al2O3 catalyst alone and plasma alone. The numerical model has a good agreement with experiments in ammonia formation. The path flux analysis shows the significant roles of excited species N(2D), H2(v1), N2(v) in stimulating the formation of precursors NH, NH2, and adsorbed N(s) through the pathways N(2D) + H2 → NH + H, H2(v1) + NH → NH2 + H and N2(v) + 2Fe(s) → N(s) + N(s), respectively. Furthermore, the results show that the adsorption reaction N + Fe(s) → N(s) and Eley–Ridel interactions N(s) + H → NH(s), N + H(s) → NH(s), NH + H(s) → NH2(s) and NH2 + H(s) → NH3(s) can kinetically enhance the formation of ammonia, which further highlights the plasma-enhanced surface chemistry. This work provides new insights into the roles of excited species and plasma-enhanced surface chemistry in the plasma catalytic ammonia synthesis.

Hypersonic interception weapons have high requirements for the efficiency and accuracy of the control system. As an effective control approach, the thermochemical non-equilibrium effect of jet flow must be considered in order to accurately predict the aerodynamic characteristic. At present, relevant researches are mostly focused on the low-flow rate hot jet, while numerical simulation and wind tunnel test studies on high-flow rate hot jet are rare. In this paper, the interaction flow field of the rail-controlled jet at the altitude of 60Km and 70Km has been simulated by solving the three-dimensional viscous fluid governing equations. The influence of the thermalchemical non-equilibrium effect of the jet interaction on the flow field characteristics and aerodynamic characteristics of the aircraft was analyzed. The primary results show that: (1) The flow fields of the cold-gas jet, frozen-gas jet and hot-gas jet have significant differences under the high-flow rate jet condition, which is mainly reflected the size and the pressure value of the separation region before the nozzle. The separation region length of the cold-gas jet is approximately twice that of the hot-gas jet and the length of the frozen-gas jet is between them; (2)Jet interaction will increase the surface pressure of the aircraft and reduce the skin-friction. When Ma=25, the aerodynamic interaction of hot jet is only about 30% of that of cold jet; (3) Jet interaction on aerodynamic characteristics increases with altitudes. With the increase of Mach number, the difference between the predicted results of hot jet and cold jet is enlarged because of the enhancement of the thermochemical non-equilibrium effect.

Ion chemistry with temperature evolution in weakly ionized plasma is important in plasma-assisted combustion and plasma-assisted catalysis, fuel reforming, and material synthesis due to its contribution to plasma generation and state transition. In this study, the kinetic roles of ionic reactions in nanosecond discharge (NSD) plasma-assisted temperature-dependent decomposition and oxidation of methane are investigated by integrated studies of experimental measurements and mathematical simulations. A detailed plasma chemistry mechanism governing the decomposition and oxidation processes in a He/CH4/O2 combustible mixture is proposed and studied by including a set of electron impact reactions, reactions involving excited species, and ionic reactions. A zero-dimensional model incorporating the plasma kinetics solver ZDPlasKin and the combustion chemical kinetics solver CHEMKIN is used to calculate the time and temperature evolution of the ion density. Uncertainty analysis of ionic reactions on key species generation is conducted by using different referenced data, and insignificant sensitivity is found. The numerical model is consistent with experimental data for methane consumption and generation of major species including CO, CO2, and H2. By modeling the temporal evolution of key ions, it is observed that O2 + presents the largest concentration in the discharge stage, followed by CH4 +, CH3 +, and CH2 +, which is in accordance with the traditional ion chemistry in hydrocarbon flames and agrees well with molecular-beam mass spectrometer investigations. The path flux shows that the concentrations of key species, including electrons, O, OH, H, O(1D), O2(a1Δg), O2 +, CH3 +, and CH4 +, change within 1–2 orders of magnitude and that the transition from a homogeneous state to a contracted/constricted state does not occur. The path flux and sensitivity analysis reveal the significant roles of cations in the stimulation of active radical generation, including CH, O, OH, and O(1D), thus accelerating methane oxidation. This work provides a deep insight into the ion chemistry of temperature-dependent plasma-assisted CH4 oxidation.

Strong field ionization-photofragmentation (SFI-PF) with ultrafast pump–probe scheme is a powerful approach to study the dynamics of molecular cationic electronic states. Here we carry out a SFI-PF study on the cationic electronic states of vinyl bromide, C2H3Br. The yields of the parent C2H3Br+ and the formation of the fragment (Br+, C2H2 + and C2H3 +) ions have been measured at different pump–probe delay time. Analysis provides experimental evidence of A 2 A ′ –X2A″ internal conversion of vinyl bromide cations which occurs in a time of about 220 fs, and the time of C2H3 + formation induced by the dissociation of the A 2 A ′ state around 300 fs. The study would add our knowledge of the behavior of electronic excited states of complex molecular cations.

A novel reconfigurable band-stop filter using piezomagnetic-piezoelectric superlattices with the external direct-current (DC) electric field (PPSED) is presented. The center frequency of the forbidden band is reduced from to Hz in the band-stop filter as the thickness ratio of the piezoelectric domain to the piezomagnetic domain increases from to 9. The change of the forbidden bandwidth and the center frequency shows that the band-stop filter constructed by the PPSED is reconfigurable. The coupled polaritonic band structure is asymmetric with respect to the forward and backward directions and the forbidden bandwidth can be tuned by the DC electric field via the electro-optic effect. Unlike pure piezoelectric superlattices with the DC electric field, the forbidden bandwidth decreases with the increase of the electric field in the PPSED. The bandwidth tunability by the DC electric field can provide a guidance for the reconfigurable band-stop filter design to work in broadband frequencies.

Interfacial engineering has made an outstanding contribution to the development of high-efficiency perovskite solar cells (PSCs). Here, we introduce an effective interface passivation strategy via methoxysilane molecules with different terminal groups. The power conversion efficiency (PCE) has increased from 20.97% to 21.97% after introducing a 3-isocyanatopropyltrimethoxy silane (IPTMS) molecule with carbonyl group, while a trimethoxy[3-(phenylamino)propyl] silane (PAPMS) molecule containing aniline group deteriorates the photovoltaic performance as a consequence of decreased open circuit voltage. The improved performance after IPTMS treatment is ascribed to the suppression of non-radiative recombination and enhancement of carrier transportation. In addition, the devices with carbonyl group modification exhibit outstanding thermal stability, which maintain 90% of its initial PCE after 1500 h exposure. This work provides a guideline for the design of passivation molecules aiming to deliver the efficiency and thermal stability simultaneously.

Aiming at the common problems on flood control impact assessment of linear projects, combined with practical work experience, this paper summarizes and analyzes the characteristics and main impact types of linear projects involving rivers and embankments in recent years, and puts forward the key points of river and embankment impact assessment of linear projects in Zhejiang Province from the aspects of early site selection, construction mode, control factors and remedial measures. It is helpful to improve the quality of flood control impact assessment report, and provide reference for the design, construction, consultation and review of water conservancy department.

The layout of battery pack for plug-in hybrid car is usual a difficult problem. The layout analysis involves the balance of battery pack capacity, ride space, passability and other performance. Through dimensional chain analysis, this paper refines each problem, balances each performance, and obtains a reasonable scheme. This paper also studies the layout of the battery for the expansion of electricity. At last, the layout method of battery pack for plug-in hybrid vehicle is summarized.

A macromolecular flame retardant was firstly the group reaction of DOPO-HQ. The modified polystyrene ADOPO-HQ-co-PS was prepared by copolymerization of macromolecular flame retardant and styrene. Its chemical structure was analyzed by Fourier transform infrared (FT-IR). PS composite was prepared by adding it to the experimental formula, and the cone-shaped calorimetry experiment was carried out on the material. The results show that it has a better flame retardant performance than DOPO-HQ. The smoke generation rate is very small, the highest is 0.2m 2/s, the CO production is very small, the highest is 0.007g/s, and the mass loss is the highest is 0.14g/s, which shows that the material is more environmentally friendly and stable during combustion.

With the rapid development of computer technology, Virtual Reality Technology (hereinafter referred to as VRT) has been applied to a variety of industries, especially industry. With the development of science and technology, people have higher requirements on the structure, quality and accuracy of products, such as aircraft shell, engine blade, mold, automobile complex surface, etc., which requires the application of Five axis CNC (hereinafter referred to as FA-CNC) machine tools. FA-CNC machine tool is the most recognized CNC machine tool in the market, which can achieve flexible pose conversion. Through the FA-CNC machine tool, we can achieve one-time clamping, which will better complete the processing of parts. Through the FA-CNC machine tool processing, we can ensure the processing accuracy, which can greatly improve the production efficiency. At the same time, CNC machining (hereinafter referred to as FA-CNC) simulation is the last verification program, which can verify the correctness of the program [1]. Through VRT, we can make clear the various conditions in the process of processing, which will facilitate the analysis of the processing program. Based on UG platform, this paper studies the impeller programming process. Through the VRT, this paper carries on the simulation verification to the processing technology, which will better complete the impeller and other complex surface structure equipment processing.

The generation of stylish Chinese fonts plays a central role in many applications such as the design of art fonts and Chinese calligraphy generation. Most of existing methods focus on the generation of a single-style Chinese font, while few works focus on the multi-style font generation. In this paper, we exploit the star generative adversarial networks (StarGAN), a very popular generative adversarial networks (GAN) model recently developed in the literature, to realize the generation of multi-style Chinese fonts via a single model. Furthermore, in order to tackle the generation issue of Chinese characters having similar strokes for StarGAN, i.e., generating the same mode for these different but similar Chinese characters, we introduce a diversity regularizer such that the generator can generate high-quality characters with better diversity. A series of experiments are conducted on a handwritten Chinese character dataset called CASIA-HWDB1.1 and three standard printing font datasets to show the effectiveness of the proposed method. The experiment results show that the proposed method can effectively tackle the generation issue of Chinese characters having similar strokes in terms of the quality and diversity of generated results, via comparing to the baseline StarGAN, and is scalable to the multi-font generation via comparing to existing methods for the single-style font generation.

Deep learning has shown great advantages in biomedical image segmentation. The classic model U-Net uses a stacked encoding-decoding structure of convolution operations for feature extraction and pixel-level classification. The stacking of convolutional layers can expand the receptive field, but it is still a local operation and cannot capture long-distance dependence. Therefore, in this work, we propose a Global Attention Mechanism that combines channel attention module and spatial attention module and integrates different convolutions in it. Besides, we design a residual module for the traditional up and down sampling blocks. And finally, we combine them with U-Net to propose a new global attention network GAU-Net. We perform experiments on the dataset BraTS2018. Our model has increased the mIoU from 0.65 to 0.75 with only 5.4% of U-Net parameters. At the same time, the inference time is also significantly shortened with relatively good performance.

Early automatic and accurate melanoma recognition is an important method to reduce melanoma deaths. Existing methods are less sensitive to the position of the lesion areas. Network training may be affected by the uncorrelated noisy parts. In light of this circumstance, an end-to-end attention-based network AF-CNN for accurate melanoma recognition is proposed in this paper, which is mainly composed of pre-trained VGG19, attention blocks and a classification layer. Instead of treating each part of the input dermoscopy images equally, our AF-CNN model has strong discriminative ability to focus on the lesion areas. The AF-CNN was evaluated on the ISIC2017 dataset and concluded the proposed single model achieves the state-of-the-art result in melanoma recognition task.

It is a big challenge for lidar to detect soft targets over long distances in the atmosphere due to the low reflection of soft targets and the strong atmospheric attenuation. In this paper, we propose an all-day lidar system based on the 4 pixel array superconducting nanowire single-photon detectors. This significantly improves the detection efficiency of the aerosol and other targets by utilizing the advantages of high sensitivity, low dark count rate, wide dynamic range and photon number resolution. The system detects both soft targets and hard targets 100 km away in the atmosphere. In experiments, based on the photon-number resolving detection method, the lidar detects and distinguishes soft and hard targets simultaneously 50 km away during the day. Furthermore, the system obtains the wind field information in the atmosphere by monitoring clouds at a distance exceeding 86 km. The detection results indicate that the system is promising for applications as a long distance all-day lidar.

The performance of a proton exchange membrane fuel cell (PEMFC) strongly relies on the flow-field design. In this study, a three-dimensional, multiphase, and non-isothermal PEMFC model with single serpentine flow field has been developed to investigate the effect of interface contact resistance (ICR) between the bipolar plate (BP) and gas diffusion layer (GDL) on the flow field dimension. In the cases of 25 different combinations of channel and rib width, polarization curves and power density curves of the PEMFC without ICR and with ICR of 7.418 mΩ.cm2 as well as 21 mΩ.2 are investigated. The results show that ICR has little effect on channel pressure drop but on liquid water accumulation. The value of ICR affects both the ohmic loss stage and concentration loss stage of the polarization curves. The power density of the PEMFC without ICR at the operating voltage 0.5V decreases as the rib width increases, while that with ICR increases as the rib width increases. Furthermore, the influence of invalid active area in BPs caused by flow field configuration on the cell performance should not be neglected when the ICR value is lower than 10 mΩ.2.

The temperature in the high-pressure high-temperature (HPHT) synthesis is optimized to enhance the thermoelectric properties of high-density ZnO ceramic, Zn0.98Al0.02O. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy show that HPHT can be utilized to control the crystal structure and relative density of the material. High pressure can be utilized to change the energy band structure of the samples via changing the lattice constant of samples, which decreases the thermal conductivity due to the formation of a multi-scale hierarchical structure and defects. The electrical conductivity of the material reaches 6 × 104 S/m at 373 K, and all doped samples behave as n-type semiconductors. The highest power factor (6.42 μW ⋅ cm−1⋅K−2) and dimensionless figure of merit (zT = 0.09) are obtained when Zn0.98Al0.02O is produced at 973 K using HPHT, which is superior to previously reported power factors for similar materials at the same temperature. Hall measurements indicate a high carrier concentration, which is the reason for the enhanced electrical performance.

Machine learning surrogate models for quantum mechanical simulations has enabled the field to efficiently and accurately study material and molecular systems. Developed models typically rely on a substantial amount of data to make reliable predictions of the potential energy landscape or careful active learning and uncertainty estimates. When starting with small datasets, convergence of active learning approaches is a major outstanding challenge which limited most demonstrations to online active learning. In this work we demonstrate a $\Delta$-machine learning approach that enables stable convergence in offline active learning strategies by avoiding unphysical configurations. We demonstrate our framework's capabilities on a structural relaxation, transition state calculation, and molecular dynamics simulation, with the number of first principle calculations being cut down anywhere from 70-90%. The approach is incorporated and developed alongside AMPtorch, an open-source machine learning potential package, along with interactive Google Colab notebook examples., Comment: 8 pages, 5 figures, submitted to Machine Learning: Science & Technology journal of IOP

Electrical characteristics of a nozzle-attached meso-scale premixed methane-air flame under low-frequency AC (0-4300 V, 0-500 Hz) and DC (0-3300 V) electric fields were studied. I-V curves were measured under different experimental conditions to estimate the magnitude of the total current 100-102 μA, the electron density 1015-1016 m−3 and further the power dissipation ≤ 0.7 W in the reaction zone. At the same time, the meso-scale premixed flame conductivity 10−4-10−3 Ω−1m−1 as a function of voltage and frequency was experimentally obtained and was believed to represent a useful order-of magnitude estimate. Moreover, the influence of the collision sheath relating to Debye length (31–98 μm) and the contamination layer of an active electrode on measurements was discussed, based on the combination of simulation and theoretical analysis. As a result, the electrode sheath dimension was evaluated to less than 0.5 mm, which indicated a complex effect of the collision sheath on the current measurements. The surface contamination effect of an active electrode was further analyzed using the SEM imaging method, which showed elements immigration during the contamination layer formation process.

Electrical properties of the wafer bonding p-GaAs/n-GaN, p-GaAs/n-Si and p-GaAs/ITO//ITO/n-Si are investigated systematically by scanning Kelvin probe force microscopy (KPFM), capacitance–voltage (C–V) and current–voltage (I–V) measurements. By using KPFM, the contact potential distributions and contact barrier differences of these bonding heterojunctions with Schottky-like characteristics or ohmic feature have been obtained. The contact barrier differences measured by KPFM match well with those measured by C–V. These barriers indicate the thicker interface layer has a larger barrier height, which could contain more interface states. The I–V curve of the heterostructure with the smaller contact barrier difference is shown as an Ohmic contact feature. In contrast, the I–V curve of the junction with the larger contact barrier difference shows a Schottky contact behavior with a larger turn-on voltage. These behaviors indicate that the electrical conductivity of the bonding sample depends on the bonding interface layer significantly.

Perovskite solar cells (PSCs) have rapidly developed in recent years with the advantages of high efficiency and low cost. Although PSCs are the fastest-advancing solar technology to date, bottlenecks such as J–V hysteresis have limited the further development significantly. In this work, we have investigated the in-depth mechanism of hysteresis in both three-dimensional (3D) and quasi-2D (Q-2D) planar p-i-n PSCs. We conducted scanning-rate-dependent and temperature-dependent measurements to distinguish the ion migration and the capacitive charging. The coefficient for capacitance and pseudocapacitance from the J–V curves are further employed to analysis the hysteresis. It is found that both capacitance and ion migration contribute to the J–V hysteresis, but play different roles in 3D and Q-2D perovskite devices. In 3D PSCs, the ion migration has substantial impacts on the J–V hysteresis, wherein ions are tending to move. While in the Q-2D PSCs, the capacitance extends the characteristic charging time, which is mainly responsible for J–V hysteresis. These findings will help to effectively suppress the hysteresis for 3D and Q-2D PSCs, eventually benefiting device performance and long term stability.

Self-lubricating gears can better adapt to the bad lubrication conditions without oil or oil scarcity. Staggered groove can be produced by Electrochemical machining (ECM) on the gear tooth surface to fill solid lubricating materials. The cathode with and without flow slot has been designed. Three basin models have been established which are forward flow mode, reverse flow mode and side flow mode. The gap flow field of ECM has been analyzed. It is determined that positive flow is a suitable flow mode. By optimizing the structure of the flow slot in the cathode, the deficiency of the forward flow field is improved.

A macromolecular antioxidant was prepared by copolymerization with styrene and modified A1010-co-PS. Its chemical structure was confirmed by Fourier transform infrared (FTIR). It was added into the formula of PS composite material and the thermal and oxygen aging experiment was carried out on the material. The tensile strength is stable at about 27MPa, the bending strength is stable at about 33MPa, and the impact strength is stable at about 2.3kJ/m2. The results show that it has a more significant effect than antioxidant 1010 and has higher performance stability.

With the rapid decrease of available water resources, to satisfy the needs of human life, it is urgent to treat and purify the water resources of waterworks so that the purified water can satisfy people’s needs. This article mainly elaborates on the current research progress of tap water treatment technology and advanced treatment technology. Provide some basis for the application of social enterprises and scientific research workers.

In this paper, we explore the localization condition of Kalb–Ramond (KR) tensorial gauge field on a thick de Sitter (dS) brane. Following the localization mechanism in the work by Chumbes et al (2012 Phys. Rev. D 85 085003), we analyze the localization of KR tensorial gauge field on a non-flat three-brane. We propose three kinds of coupling methods and two of them support the localization of zero mode. In addition, there exist resonant Kaluza–Klein modes on the thick dS brane. The effects of three parameters on the localization and the resonant mode for the KR field are also discussed.

To improve the traffic safety at the two-phase intersection, collision risk value between the left-turn vehicle and the straight vehicle in the opposite direction could be used to judge their order. Based on the safety and risk, this method analyzed the process of conflict, modified the operating parameters and then collision risk analysis model was proposed. In the paper, one practical example was given. The result shows that the method can be applied to design the signal phasing-sequence of traffic at signalized intersection, which not only improve safety theory but also provide the theoretical basis for security information service.

The gear with solid lubricating material embedded in micro grooves on gear tooth surface can better adapt to severe lubrication conditions. Electrochemical machining with the mask has shown good feasibility in machining micro grooves for filling solid self-lubricating materials on the tooth surface of gear. The electrolyte flow field is a vital contributor to the accuracy of electrochemical machining, therefore, it is important to design a suitable electrolyte flow mode. In this paper, based on the distribution characteristics of micro grooves on gear tooth surface, two kinds of shaped cathodes are designed, one with electrolyte flow slot and the other without. Each cathode can form two electrolyte flow modes respectively. The effects of four electrolyte flow modes on the stability of the machining gap flow field are analyzed by using computational fluid dynamics. The simulated results show that the cathode without electrolyte flow slot is beneficial to electrolyte flow during electrochemical machining with the mask, notably when the electrolyte flows into the machining gap from the face of the gear.

The recognition and extraction of visual text information is the basis of the realization of Text-to-Scene Conversion, while nouns are the main expression form of entity, event, orientation, action and other information in text, but not all nouns are suitable for visualization, so how to recognize the visibility of nouns is the key problem of Text-to-Scene Conversion. Based on the definition and classification of noun visualization, this paper establishes a keyword visibility dictionary. Furthermore, in view of the static limitations of the dictionary, a dynamic expansion method based on semantic similarity is studied, and an optimization method for the visibility annotation of nouns is proposed in combination with unsupervised clustering. The experimental results show that the proposed method is effective and feasible for nominal visibility annotation of common texts, and the accuracy of the optimized method is 16% higher than that of the simple semantic similarity method.

The river chief system has been advanced in all respects, river management is an important part of river chief system. River demarcation refers to the demarcation of river shoreline and the scope of management and protection, which is the premise of water management. Based on the analysis of the present situation, management and demarcation of the river in Anji County, the article puts forward the management problem and necessity of the demarcation of the current situation of the river in Anji County, and puts forward the principles and methods of the demarcation of the river shoreline and the scope of management protection according to different types.

Based on density function theory with the ultrasoft pseudopotential scheme in the frame of the local density approximation and the generalized gradient approximation, the structural, elastic, and electronic properties of carbon with P2221 phase have been systematically studied in this paper. The calculated results show that the P2221 phase of carbon is mechanically stable and dynamically stable at ambient pressure. The anisotropy studies of Young's modulus, Poisson's ratio, shear anisotropic factor, the percentage of elastic anisotropy for bulk modulus, the percentage of elastic anisotropy for shear modulus and the universal anisotropic index show that P2221 phase of carbon exhibits anisotropy. In addition, P2221 phase is an indirect semiconductor with bandgap of 3.423 eV. But, the band gap of P2221 phase for carbon increase with increasing pressure.

In order to maintain the pipeline better and remove the dirt more effectively, it was necessary to analyze the contents of elements in dirt. Mg in soil outside of the pipe and the dirt inside of the pipe was quantitatively analyzed and compared by using the laser-induced breakdown spectroscopy (LIBS). Firstly, Mg was quantitatively analyzed on the basis of Mg I 285.213 nm by calibration curve for integrated intensity and peak intensity of the spectrum before and after subtracting noise, respectively. Then calibration curves on the basis of Mg II 279.553 nm and Mg II 280.270 nm were analyzed. The results indicated that it is better to use integrated intensity after subtracting noise of the spectrum line with high relative intensity to make the calibration curve.

In this paper, the generalized Darboux transformation is constructed to variable coefficient nonlinear Schrodinger (NLS) equation. The N-th order rogue wave solution of this variable coefficient NLS equation is obtained by determinant expression form. In particular, we present rogue waves from first to third-order through some figures and analyze their dynamics.