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Copyright of Uranium Mining & Metallurgy is the property of Uranium Mining & Metallurgy Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The blasting load during tunnel construction generates significant dynamic disturbances to the surface slopes. The poor stability of the accumulated layer slopes makes it highly susceptible to forming landslides in the accumulated layer and causing tunnel collapses. Based on the Qiaoping Mountain Tunnel project on the Yu-Xiang Expressway, a numerical model of the soil-rock mixture granular flow accumulated layer slope was established by combining CT scanning technology and the clump command in PFC. Dynamic triaxial tests were conducted to calibrate the mechanical parameters of the accumulated layer model. The FLAC 3D -PFC 3D coupling analysis method was used to study the stability of slopes with different accumulated layer thicknesses under tunnel excavation blasting. The results show that under the action of explosive stress waves, as the thickness of the accumulated layer increases from 0. 25 times to 1. 0 times the tunnel span, the particle velocity in the accumulated layer decreases by about four times, and the range of particle loosening almost disappears. The particle settlement slowly decreases from 2 cm to 1 cm and then remains stable. The bond-to-tension force chain ratio between particles rapidly increases from 2. 2 to 4. 5. Subsequently, the tensile failure between particles is minimal, and particle sliding is less likely to occur, leading to improved stability of the accumulated layer. When the accumulated layer thickness exceeds 1. 0 times the tunnel span, the area of the plastic zone produced by blasting is almost symmetrically distributed and approximates the cross-sectional area of the tunnel. The plastic zone is located within the bedrock range and is concentrated near the arch crown and arch base. Overall, when the accumulated layer thickness exceeds 1. 0 times the tunnel span, the dynamic disturbance effect of tunnel excavation blasting on the slope is significantly reduced. These findings provide theoretical support for the design and construction of tunnel entrance sections. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Space-Integrated-Ground Information Networks is the property of Beijing Xintong Media Co., Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Reclosing during a permanent fault subjects the transformer to secondary impacts， thereby increasing the likelihood of transformer damage. In this paper， a computational model for calculating the leakage magnetic field of a three-winding transformer operating in "high-medium-low" mode is first established. Subsequently， a nonlinear model for the axial vibration of winding coils is developed， and a dynamic calculation method for the axial pressure on the coils and spacers is proposed. Finally， the established model is utilized to evaluate the axial strength of a 110 kV transformer under reclosing operation conditions. The results indicate that during reclosing in the poorest operating condition， the leakage magnetic field of the transformer increases， vibrations become more intense， and the forces acting on the coils and spacers are greater， thereby increasing the possibility of axial instability in the transformer. These findings can provide a basis for the verification of operating conditions for transformers during reclosing.

Copyright of Journal of Ordnance Equipment Engineering is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: In order to investigate the effects of the dual action of F-T cycles and dynamic perturbation on the stability of slopes in open pit mines in cold regions. Method: we use the pendulum impact-loaded Split Hopkinson Pressure Bar(SHPB)test system to explore dynamic peak loads, loading rate sensitivity, and damage modes of intact granite and prefabricated single-crack granite specimens under dry, water-saturated, and frozen conditions. Additionally, we modeled dynamic Brazilian splitting tests of saturated specimens with empty cracks to verify their accuracy and subsequently simulate the damage patterns and strength-rate effects of crack-filled saturated specimens under different loading rates. Result: The results indicate that, under identical loading rates, the dynamic tensile peak load of frozen specimens is the highest, then the dry specimens, the saturated one is the lowest. The peak load of intact specimens exceeds that of specimens containing cracks, suggesting that pre-existing cracks reduce the peak load of specimens. Furthermore, the dynamic tensile peak load of specimens under different water contents and freezing states is positively correlated with the loading rate, demonstrating the loading rate strengthening effect. Specifically, the rate of increase for the dynamic tensile peak load of intact and cracked specimens under dry, water-saturated, and frozen conditions is 0.465, 0.456, 0.445, 0.479, 0.438, 0.480, respectively. This implies that freezing enhances dynamic strength, saturation weakens strength, and pre-existing cracks amplify loading rate sensitivity. Additionally, crack saturation increases the strength of saturated specimens and expands the range of crack propagation. Conclusion: The research findings provide experimental and simulation support for revealing the dynamic fracture mechanism of rocks with single fractures under different freezing conditions. [ABSTRACT FROM AUTHOR]

Copyright of Zhejiang Electric Power is the property of Zhejiang Electric Power Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transportation Science & Technolgy is the property of Transportation Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study sought to clarify the importance of verifying the dynamic stability of cultivated land change and, on this basis, to predict cultivated land change in the“14th Five-Year Plan”target（2025）and long-term target years（2035）of Ganyu District. The aim was to provide reference data for relevant academic research and future cultivated land protection projects. The coefficient of variation of cultivated land, geographical concentration index, imbalance index, and trend analysis method were used. The dynamic stability of cultivated land change in Ganyu District was verified in three aspects：cultivated land quantity, spatial distribution, and spatial development trend. The future change in cultivated land under different policy scenarios was simulated by a CA-Markov model. The total amount of cultivated land in the Ganyu District continued to decline without major repetition or fluctuation. The spatial distribution of cultivated land was relatively balanced, and the spatial development trends of cultivated land occupation and supplementation were relatively continuous. On the whole, the changing process of cultivated land had high dynamic stability, consistent with the preconditions of the CA-Markov model. Under various policy scenarios, Ganyu District will still experience a rapid process of cultivated land conversion before 2025, and the rate of cultivated land reduction will slow by 2035. With regional advantages, the northern area of Ganyu District will be the key area of cultivated land conversion in the future, and cultivated land will gradually transfer to the southern inland area. Verifying the dynamic stability of cultivated land changes can effectively improve the simulation accuracy of the CA-Markov model. The future situation of cultivated land protection in Ganyu District is not optimistic. The relationship between economic development and cultivated land protection should be reasonably coordinated to ensure social, ecological, and food security. [ABSTRACT FROM AUTHOR]

Copyright of Bearing is the property of Bearing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The microwave-absorbing materials have excellent microwave heat transfer capacity and can be used for self-repairing micro cracks in asphalt pavement. Three microwave-absorbing materials, carbon black powder, carbonyl-iron powder and Ni-Zn ferrite powder, were used to replace some mineral powder to prepare SMA-13 microwave-absorbing asphalt mixture. The pavement performance of different absorbing asphalt mixtures was compared and analyzed by wheel tracking, low-temperature bending and freeze-thaw splitting tests, and the influence of microwave-absorbing material type, dosage, microwave heating time and other factors on the surface temperature distribution and the self-healing performance of microwave-absorbing asphalt mixtures were investigated by semi-circular bending (SCB) tests. Microscopic analysis of the microwave-absorbing materials was performed using scanning electron microscope (SEM) and X-ray diffraction (XRD). The results indicate that the dynamic stability and freeze-thaw splitting strength ratio of the carbon black powder asphalt mixture increases gradually with the increase of the content of absorbing material from 10% to 30%, while the low temperature bending strain first increases and then decreases. The dynamic stability and low temperature bending strain of the carbonyl iron powder asphalt mixture first increases and then decreases, while the freeze-thaw splitting strength ratio decreases. The dynamic stability and low temperature bending strain of the Ni-Zn ferrite powder asphalt mixture decreases, while the freeze-thaw splitting strength ratio is opposite. The surface temperature of absorbing asphalt mixture gradually increases with the increase of microwave-absorbing material dosage and microwave heating time, which can quickly reach the healing temperature of the crack surface of asphalt mixture, thus strengthening the microwave self-healing performance of the asphalt mixture. [ABSTRACT FROM AUTHOR]

In order to study the influence of long-term water action on the behavior characteristics of steel slag aggregate-asphalt interface and the related mechanism, atomic force microscope, X-ray diffraction, scanning electron microscope, immersion Marshall test, rutting test and so on were used to analyze from macro and micro perspectives. The results show that long-term water erosion changes the surface chemical properties of steel slag, making the surface roughness, surface area and adhesion strength of the steel slag increase. Compared with limestone asphalt mixture, the residual stability and dynamic stability of steel slag asphalt mixture have a growth potential, but the swelling of hot-sealed steel slag and cold-sealed steel slag is different. The swelling amount of cold-sealed steel slag asphalt mixture is greater than that of hot-sealed steel slag asphalt mixture, which should be treated differently in the application process. The slow digestion rate of f-CaO in cold-sealed steel slag aggregate causes the volume expansion of the specimen in the late stage, aggravates the generation of microcracks on the surface of the specimen, and results in the poor freeze-thaw splitting strength of cold-sealed steel slag asphalt mixture in the late stage. [ABSTRACT FROM AUTHOR]

The gussasphalt mixture has excellent water tightness, coordinated deformation ability and durability, while the epoxy asphalt mixture has extremely outstanding strength and heavy load on high temperature resistance. In order to realize the integration of the advantages of the two mixtures, the epoxy gussas-phalt mixture is proposed. The mechanical properties and 170 °C viscosity tests of epoxy resin and hot mixed epoxy asphalt from three sources were carried out; based on the mix proportion design of hot mixed epoxy gussasphalt mixture, the fluidity, Marshall, penetration, rutting, bending and fatigue performance tests of the mixture with mixing time of 45 min and 135 min were carried out. The results show that the mechanical properties of the three epoxy resins and the hot mixed epoxy asphalt are basically the same, and the viscosity is up to 1 Pa ⋅ s at 170 °C for more than 3 h; the performance of mixture attenuates greatly with the increase of mixing time; the type of epoxy asphalt has no significant effect on the performance indexes except flow value and ultimate flexural strain. When mixing for 45 min, the performance of XB epoxy gussasphalt mixture is the best, the fluidity is less than 5 s, and the constructability fluidity maintenance time is more than 135 min. The Marshall stability exceeds 48 kN, the rutting dynamic stability reaches 18 945 times/mm, the penetration increment is only 0.1 mm, and the ultimate flexural strain at - 10 °C exceeds 3 000 µε. The impact toughness of fatigue performance index reached 3 517 N ⋅ mm, and its performance was far higher than that of conventional gussasphalt mixture, and many indexes were also higher than that of epoxy asphalt mixture, and the cost is also relatively low. The hot mixed epoxy gussasphalt mixture has the advantages of both the gussasphalt mixture and the hot mixed epoxy asphalt, which can effectively improve the high-temperature strength of the gussasphalt mixture, and is of great significance to improve the quality and durability of steel bridge pavement in China. [ABSTRACT FROM AUTHOR]

In order to clarify the influence of asphalt species on the pavement performance of semi-flexible pavement, used matrix asphalt, SBS modified bitumen and high-viscosity modified asphalt to prepare semi-flexible pavement materials, perform gradation optimization, and test to explore the influence of asphalt species on semi-flexible pavement perfusion rate, high temperature stability, water stability and strength in the past. The results showed that the stability of the parent asphalt mixture prepared with different asphalt increased first and then decreased with the increase of oil-stone ratio, while the porosity decreased continuously, and the stability of the mixture using SBS modified bitumen and high-viscosity modified asphalt increased under the same oil-stone ratio and decreased. The type of asphalt had little effect on the perfusion rate, SBS modified bitumen and high-viscosity asphalt could improve the water stability and high temperature stability and strength of the pavement in the past, and the lifting effect was basically the same. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Donghua University (Natural Science Edition) is the property of Journal of Donghua University (Natural Science) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bearing is the property of Bearing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Engineering Management / Gongcheng Guanli Xuebao is the property of Journal of Engineering Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transportation Science & Technolgy is the property of Transportation Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Oil based drilling fluids have been widely used in drilling unconventional wells, and one of the key problems with the use of oil based drilling fluids is how to effectively clean off the residue mud and the mud cakes on the borehole wall to provide a good bonding surface for cement slurries. Nanometer emulsion has low surface tension, small droplets and strong solubilization capacity, making it a good flushing fluid for cleaning residue oil based drilling fluids. Take the flushing efficiency and the sizes of the emulsion droplets as the evaluation criteria, a nanometer emulsion was selected as a flushing fluid for residue oil based mud cleaning. By testing the stability, electric potential and sizes of the droplets, the compatibility of the emulsion and spacer additives was analyzed, and a nanometer emulsion flushing spacer was formulated as a result of the study. Laboratory studies show that by changing the ratio of two surfactants, which are alkyl glycoside and polyoxyethylene ether, from 2∶8 to 9∶1, the flushing efficiency of the nanometer emulsion first increased and then decreased, the sizes of the droplets first decreased and then increased. The consistency between the flushing efficiency and small droplet size of the nanometer emulsion provides a theoretical basis for selecting an emulsion with both high flushing efficiency and dynamic stability. Some polymer additives will increase the viscosity of the nanometer emulsion and the oil-water interfacial tension, but do not significantly affect the stability of the nanometer emulsion. Surfactants with opposite charges will decrease the Zeta potential of a nanometer emulsion droplet, leading to a decrease of the stability of the nanometer emulsion. Commonly additives can be directly used to control of properties of a nanometer emulsion and to make nanometer emulsion flushing spacers. The spacer formulated in this study has stable rheology, high settling stability and good compatibility with cement slurries at temperatures up to 100 ℃. At 120 ℃, the spacer has flushing efficiency in 3 min of more than 99% and is able to remarkably enhance the bonding strength of the cement sheaths on the walls of the borehole drilled with an oil based drilling fluid. [ABSTRACT FROM AUTHOR]

This paper took Wanrong Tunnel of Haolebaoji-Ji'nan Railway as the research object, based on various parameters such as length, height and distribution range of the surrounding rock arch cavity, the dynamic response characteristics of the tunnel and the tunnel lining stress were studied. On the basis of analyzing the mechanism and the method of applying train dynamic loads, a vehicle track tunnel dynamic finite element model was established to calculate the effects of different cavity parameters on tunnel displacement, acceleration, and lining principal stress under the action of train loads. Research shows that cavities exacerbate the vibration response of various parts of the tunnel, with the dynamic response of the arch changing the most. When the height of the cavity increases from 0 to 20 cm, the peak displacement of the arch increases by nearly three times, while the displacement of the inverted arch is the smallest. The cavity also changes the stress state of the lining concrete (from compression to tension), which is extremely unfavorable for the concrete material. As the range of voids continues to increase, the impact of dynamic loads on the arch increases. The peak acceleration of the arch increases from 1. 62 m/ s-2 without voids to 3. 49 m/ s-2, indicating that the structure is already in an unstable state. [ABSTRACT FROM AUTHOR]

Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Geology & Exploration is the property of Xian Research Institute of China Coal Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Ordnance Equipment Engineering is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Sciencepaper is the property of China Sciencepaper and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Control Theory & Applications / Kongzhi Lilun Yu Yinyong is the property of Editorial Department of Control Theory & Applications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Jilin University (Science Edition) / Jilin Daxue Xuebao (Lixue Ban) is the property of Zhongguo Xue shu qi Kan (Guang Pan Ban) Dian zi Za zhi She and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Inorganic Chemicals Industry is the property of Editorial Office of Inorganic Chemicals Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Based on the recent studies on the stability of heavy oil emulsion at home and abroad, the influencing factors of the stability of oil-in-water heavy oil emulsion were reviewed. The formation of oil-in-water heavy oil emulsion and the properties of oil-water interface film are introduced. The strength of oil-water interface film largely determines the stability of oil-in-water heavy oil emulsion. Secondly, the dynamic stability and static stability of heavy oil emulsion were comprehensively analyzed. Water content, particle size distribution of emulsion, emulsification temperature, interfacial tension, salinity and chemical additives all have certain influence on the stability of oil-in-water heavy oil emulsion. The measurement of particle size distribution of emulsion based on focused beam reflection measuring instrument is introduced, which provides a certain reference value for studying the dynamic stability of heavy oil emulsion. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin University of Science & Technology is the property of Journal of Harbin University of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Maintaining postural stability during walking is critical for the prevention of falls, and how dynamic stability alters during cognitive dual-task walking remains controversial. OBJECTIVE: To explore the influence of cognitive load factors on posture control performance of dual-task research paradigm by comparing the differences of dynamic stability during walking under four different cognitive loads, and to provide theoretical basis for dynamic stability rehabilitation training. METHODS: The Motion three-dimensional motion capture system was used to collect the kinematic data of 16 male college students during walking under different cognitive loads (zero load, one load, double load and triple load), and the dynamic stability margin was calculated indirectly through the kinematic data. Among them, cognitive single-task walking refers to walking + zero times cognitive load; cognitive dual-task walking refers to walking + one, two, and three times cognitive load. Univariate repeated measure analysis of variance was used to compare the differences of gait parameters and dynamic stability under different cognitive loads. RESULTS AND CONCLUSION: (1) Compared with zero load, walking speed and dynamic stability margin of other cognitive loads were decreased (P < 0.05). (2) Walking speed and step length of double cognitive load were lower than those of one cognitive load (P < 0.05). The step length of double cognitive load was lower than that of zero cognitive load (P < 0.05). (3) Step width parameters had no statistical significance when walking under different cognitive loads (P > 0.05). (4) It is indicated that with the increase of cognitive load, young adults responded to the intervention of cognitive task mainly by decreasing stride speed and stride length and changing gait pattern. During dual-task walking, the intervention of cognitive task did not affect step width parameters, and it is not recommended to use step width parameters as an effective indicator to evaluate the performance of dual-task posture control when evaluating the effectiveness of dual-task rehabilitation training program. When the cognitive load did not exceed the total attention resources of the human body, the intervention of cognitive task increased the dynamic stability of the left and right directions during walking. For young people, different cognitive loads have little influence on postural control, and the setting of cognitive load can be appropriately reduced when implementing dual-task rehabilitation intervention. [ABSTRACT FROM AUTHOR]

In view of the problem that the traditional PCC hard switch cannot actively adjust the power flow, the back-to-back converters are used to replace the traditional PCC hard switch to flexibly interconnect the distribution network and microgrid, so as to facilitate the coordinated control between them. In order to analyze the stability of the system and consider the different number of distributed generators in microgrid of different scales, a microgrid small signal state space model framework with N distributed generators connected through back-to-back converter is established. The eigenvalue analysis is carried out using MATLAB, and the key parameters affecting the stability and dynamic performance of microgrid are determined. Finally, a microgrid flexible grid connection operation model based on droop control is built on PSCAD/EMTDC platform. The established small signal model is combined with the built simulation model, and the simulation is carried out under multiple working conditions to verify the correctness of the modeling, analysis and conclusion. [ABSTRACT FROM AUTHOR]

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nonferrous Metals (Mining Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transportation Science & Technolgy is the property of Transportation Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective This study aimed to build a surgical navigation system based on mixed reality (MR) and optical positioning technique and evaluate its clinical applicability in craniomaxillofacial trauma bone reconstruction. Methods We first integrated the software and hardware platforms of the MR-based surgical navigation system and explored the system workflow. The systematic error, target registration error, and osteotomy application error of the system were then analyzed via 3D printed skull model experiment. The feasibility of the MR-based surgical navigation system in craniomaxillofacial trauma bone reconstruction was verified via zygomatico-maxillary complex (ZMC) reduction experiment of the skull model and preliminary clinical study. Results The system error of this MR-based surgical navigation system was 1.23 mm±0.52 mm, the target registration error was 2.83 mm±1.18 mm, and the osteotomy application error was 3.13 mm±1.66 mm. Virtual surgical planning and the reduction of the ZMC model were successfully conducted. In addition, with the guidance of the MR-based navigation system, the frontal bone defect was successfully reconstructed, and the clinical outcome was satisfactory. Conclusion The MR-based surgical navigation system has its advantages in virtual reality fusion effect and dynamic navigation stability. It provides a new method for doctor-patient communications, education, preoperative planning, and intraoperative navigation in craniomaxillofacial surgery. [ABSTRACT FROM AUTHOR]

ObjectivesThe dynamic stability of large ocean-going passenger vessel is of great important to ensuring the safety of a large number of passengers. Thus, it is necessary to carry out vulnerability assessment and optimization for typical failure modes.MethodsThis study adopts the assessment methods and criteria of parametric rolling, pure loss of stability and excessive acceleration developed by the international maritime organization's (IMO) second generation intact stability criteria. For the first time, the vulnerability assessment of dynamic stability failure modes is conducted for the design scheme project of a large ocean-going passenger vessel. In order to fulfill the requirements of this project, an optimization scheme is studied and proposed for the design from a practical point of view.ResultsThe assessment results show that the original ship design scheme is not vulnerable to the evaluated dynamic stability failure modes except the pure loss of stability failure mode without considering the speed limit, that means the safety level can meet the requirement. However, the scheme cannot fulfill the requirements of pure loss of stability criterion, when the service speed needs to be increased to 24.8 kn. By slightly adjusting the design of hull and windows to improve the reserve buoyancy, the safety level of pure loss of stability failure mode can be effectively increased, and the service speed limit can be eliminated.ConclusionsThe design scheme of large ocean-going passenger vessel has a high safety margin of dynamic stability, which can fully ensure the dynamic stability and safety of large passenger vessels sailing in serious sea conditions.