bluuebunny/crossref_metadata_2025 huggingface dataset:
Particulate dominance of organic carbon mobilization from thaw slumps on the Peel Plateau, NT: Quantification and implications for stream systems and permafrost carbon release
Authors: Shakil S , Tank S E , Kokelj S V , Vonk J E , Zolkos S
Published: August 2020

Climate change is increasing the frequency and intensity of thermokarst, and accelerating the delivery of terrestrial organic material from previously sequestered sources to aquatic systems, where it is subject to further biochemical alteration. Rapid climate change in the glacially conditioned ice-rich and ice-marginal terrain of the Peel Plateau, western Canada, is accelerating thaw-driven mass wasting in the form of retrogressive thaw slumps, which are rapidly increasing in area, volume and thickness of permafrost thawed. Despite major perturbation of downstream sedimentary and geochemical fluxes, few studies have examined changes in flux and composition of particulate organic carbon (POC) in streams and rivers as a result of permafrost thaw. Here we show that the orders of magnitude increase in total organic carbon, nitrogen, and phosphorus mobilized to streams from thaw slumps on the Peel Plateau is almost entirely due to POC and associated particulate nitrogen and phosphorus release. Slump-mobilized POC is compositionally distinct from its dissolved counterpart and appears to contain relatively greater amounts of degraded organic matter, as inferred from base-extracted fluorescence of particulate organic matter. Thus, slump-mobilized POC is potentially more recalcitrant than POC present in non-slump affected stream networks. Furthermore a substantial portion of POC mobilized from thaw slumps will be constrained within primary sediment stores in valley bottoms, where net accumulation is currently exceeding net erosion, resulting in century to millennial scale sequestration of thermokarst-mobilized POC. This study highlights the pressing need for better knowledge of sedimentary cascades, mobilization, and storage reservoirs in slump-affected streams, and baseline assessments of the biodegradability of POC and cycling of particulate nutrients within a sedimentary cascade framework. Explicit incorporation of POC dynamics into our understanding of land-water carbon mobilization in the face of permafrost thaw is critical for understanding implications of thermokarst for regional carbon cycling and fluvial ecosystems.
TiO2-(Zn1/3Nb2/3)O2-ZrO2microwave dielectric ceramics with near-zero temperature coefficient of resonant frequency
Authors: Wang Geng , Fu Qiuyun , Zhang Lu
Published: August 2020

(56.33-x)TiO2-x(Zn1/3Nb2/3)O2-43.67ZrO2(x = 2.60-37.66) ceramics with 0.5%wt CuO addition were prepared by the mixed metal oxide route. Effects of sintering temperature were investigated on the sintering behavior and microwave dielectric properties of ceramics. For all ceramics with x = 2.60-37.66, the optimal sintering temperature range was determined to be around 1280 °C. XRD analysis showed that the main crystalline phase of ceramics sintered at 1280 °C changed from ZrTiO4type at x = 2.60-30.20 to ZrTi2O6type at x = 30.20-37.66. In addition to the main crystalline phase, trace amounts of secondary phases ZrO2and ZnCuTiO4were also observed from SEM and EDS analysis for all ceramics. The permittivity decreased with the increasing x in the range of x = 2.60-30.20 and then remained stable at x = 30.20-37.66, corresponding to the density and covalency bond due to the substitution of (Zn1/3Nb2/3)4+for Ti4+and phase transition at x = 30.20. Furthermore, it was surprisingly found that the temperature coefficient of resonant frequency was near-zero (τf= -9.2 to +9.9 ppm/°C) in a very wide range of x = 10.80-30.20.
Fatigue life extension of 42CrMo high-strength steel and its micro strengthening mechanism under laser shock peening
Authors: Sun Rujian , Huang Weiqing , Cao Ziwen , Che Zhigang , Zou Shikun , Wu Junfeng
Published: August 2020

Laser shock peening is an advanced surface treatment technique in improving the fatigue properties of metallic components. In this study, the effects of different laser shock peening regions on the high cycle fatigue of 42CrMo high-strength steel were investigated. Surface deformation, residual stress, and microhardness were analyzed, and microstructural evolution including grain size, boundary distribution, and misorientation was examined. Results show that peening the specimen with both surfaces and sides resulted in a better fatigue life than only peening the surface. The compressive residual stress introduced in both the surfaces and sides provided a higher resistance for fatigue initiation. In addition, the increase of low angle grain boundary accounted for the micro strengthening mechanism for the fatigue life extension.
Effect of annealing temperature on the microstructure and optical properties of MoS2 films
Authors: Zhang Bianlian , Cheng Zhen , Meng Yu
Published: August 2020

In this paper, MoS2 films were prepared on silicon and glass substrates by RF magnetron sputtering. The surface morphology, structure and transmission and reflectivity of MoS2 films were characterized by SEM, XRD and spectrometer. The effect of annealing temperature on the properties of MoS2 films was analyzed. The results show that the annealing temperature has an obvious effect on the surface morphology of MoS2 thin films, and different annealing temperature can change the position of XRD diffraction peak of MoS2 thin films. The higher the annealing temperature, the better the growth quality and the higher the transmission and reflectivity of MoS2 film.
Preparation and characteristics of Co nanoporous magnetic materials synthesized by a template-free method
Authors: Kong Jing , Li Yan , Gao Hong , Wang Xiangke , Yu Xiangtian , Yao Ziyang , Wang Fenglong , Liu Jiurong
Published: August 2020

We report a template-free hydrogen reduction approach to prepare cobalt nanoporous magnetic materials with various morphologies employing Co3O4 as precursors, which were obtained by thermal-decomposing CoCO3 intermediates. The kinetic control of experimental parameters of synthetic CoCO3 intermediates by a facile solvent-thermal route can be an effective strategy to tune the morphology of Co nanoporous structures. The microstructures, crystal structures or thermal characteristics of products at different stages were investigated to reveal the formation mechanism of the Co nanoporous structures. Magnetic measurement showed that the Co nanoporous structures with rhomb-like and prism-like morphology exhibited saturation magnetization (Ms) of 149.2 emu/g and 141.8 emu/g, and coercivity (Hcj) of 508.4 Oe and 554.9 Oe, respectively. The as-prepared Co ferromagnetic materials exhibited remarkably high coercivity values mainly due to the three dimensional nanoporous structures.
Application of PVC-melamine-formaldehyde resin composite in drug adsorption
Authors: Qi Boyi , Yang Qinghao
Published: August 2020

A new technique for the synthesis of melamine-urea-formaldehyde (MUF) resins was explored in conditions of normothermia.The MUF and common UF resin were analyzed by FTIR.The effects of activation time,pH on the adsorption performance (expressed by the adsorption capacity of Norfloxacin hydrochloride(NOR)) were investigated. The adsorption process of nonresident for Norfloxacin hydrochloride using batch technique was optimized by different parameters including pH, stirring time.The optimum stirring time was 180 min,the adsorption process was favored in acidic medium rather than alkaline one. The equilibrium data were fitted by the Freundlich and Langmuir isotherm models and the adsorption process fitted well with the linear Langmuir isotherm and pseudo- second order kinetics.
Research on the preparation and properties of biodegradable wood-plastic composites
Authors: Ge Zhenghao , Li Xiaoqian , Si Dange
Published: August 2020

In this work, the PLA/PBS/straw powder wood-plastic composite were fabricated by injection molding process. Special attention was paid to the effects of different parameters of injection molding process on the mechanical properties of the wood-plastic composite. The optimum injection molding process parameters of wood - plastic composites were determined by orthogonal experiment. According to the optimal injection molding process parameters, biodegradable wood-plastic composites filled with different compatibilizers were produced. The effects of MAPLA, silane and combination treatment on the interface compatibility and mechanical properties of the wood-plastic composite were investigated by scanning electron microscope and mechanical properties test. The results showed that the combination of the two compatibilizer treatments can improve the interface compatibility of wood-plastic composites, but the improvement of it mechanical properties is not obvious. The mechanical properties of wood-plastic composites were optimiz when the content of MAPLA was less than 5%.
Experimental analysis of damage mechanism and shrinkage performance of recycled concrete
Authors: Liu Ying , Du Tianling
Published: August 2020

This article analyzes the interface structural features and damage mechanism of recycled aggregate concrete. Recycled aggregates are divided into three types by particle shaping. Through the experiments, the shrinkage performance of recycled concrete is analyzed under the conditions of different cement content and the replacement rate of recycled coarse aggregate. The experimental results show that A is the worst, inferior to NA ordinary concrete; C is the best, superior to NA ordinary concrete.
Effect of different micro-texture shape on corrosion resistance of metal surface
Authors: Xu Rui , YongshengWang  , Wang Yipu , Wang Zhankui , Su Jianxiu
Published: August 2020

The 304 stainless steel is widely used in daily life. In this paper, the 304 stainless steel was taken as the substrate material and then the five different micro texture shapes were carved on them by nanosecond laser engraving machine under the same parameters. These shapes are the groove array, the square column array, the circular pit array, the regular hexagon column array and the trapezoid column array. Then these samples were immersed in 0.5mol/l perfluorodecyl trimethoxysilane ethanol solution at 45 °C for 5 hours. Five type super-hydrophobic surfaces were obtained. A series of corrosion experiments were conducted out and the influence of different micro texture on the corrosion resistance to the 304 stainless steel surface was analyzed. The results show that the square column array has the best corrosion resistance, and its corrosion rate is4.20mm.a−1, which is the lowest in all other micro texture shapes. It can be used as a reference for improving the corrosion resistance of metal surface.
Synthesis and fluorescence properties of dansyl labeled triazine dendrons
Authors: Li Long , Cheng Rong-chao , Ma Cha , Hao Hui-jun , Li Li-hua , Zhao Zhi-liang
Published: August 2020

A series of fluorescent dendrons with dansulfonyl group as a fluorophore attached at the focal point were synthesized by a convergent method. There was no need for tedious and lengthy protection/deprotection or chromatographic separation. The method provided simple operation and high yield. Their fluorescence characteristic in dichloromethane was investigated. The results indicated that the dendritic modification had positive effect on the emission of fluorescence, and the emission maximum of dansylated dendrons was enhanced up to 20-fold. Meanwhile, the fluorescent intensity of dansylated dendrons could be remarkably improved with the increase of dendron generation. These findings can contribute significantly to the general understanding of the dendron systems and also for potential applications in photochemical molecular devices and organic electroluminescent devices.
Coupled simulation for reentry ablative behavior of hypersonic vehicles
Authors: Mei Zongshu , Shi Chengying , Fan Xueling , Wang Xiaobin
Published: August 2020

Numerical analyses of hypersonic vehicles ablative behaviors focus on the accurate models of the thermochemical reaction flow field. The assumptions of chemical equilibrium and non-catalytic wall cannot meet the ablative behavior prediction requirements for high Mach number flights with multiphase materials. In this paper, the numerical analysis of hypersonic vehicle reentry involves the nonequilibrium thermochemical flow field and thermodynamic structure with moving boundary. Two surface models, finite rate catalysis model and Park finite rate surface interaction model were applied into the flow field simulation. And the reentry ablative behaviors of two hypersonic vehicles were simulated by the partitioning methods using the computational fluid dynamics code Fluent and the material thermal and structural response code Abaqus with user defined codes. And the two codes were loosely coupled in time to exchange the data. The structural temperature, surface shape change at the wall under different reentry altitudes and various angles of attack were obtained. The validity and reliability of frame work set up were validated with previous work.
Research on the effect of vibration of aerial cameras on imaging quality under flight conditions
Authors: Lin Jieqiong , Guo Xin , Gu Yan , Gao Minghui , Zhang Hanyuan
Published: August 2020

In order to make the structural design of the aerial camera meet the requirements of the imaging system, the influence of externally excited vibration interference on the imaging quality of the aerial camera optical system under the flying state of the UAV was studied. This paper adopts the optical-machine integrated analysis method (OIAM) to cause the vibration interference influence is studied. The MTF (modulation transfer function) is used as an evaluation index of imaging quality. The aerial camera dynamics simulation analysis is performed to extract the displacement of each node under vibration excitation. The lens deformation is fitted using the Fringe Zernike polynomial. The obtained data were used for optical performance evaluation. The analysis have showed that the optical system of the aerial camera has a 0.071% reduction in the MTF at a resolution of 91 lp / mm under the excitation of flight vibration, with little effect.
Application of tractor virtual test technology in product innovation design
Authors: Yan Xianghai , Zhou Zhili , Li Zhongli
Published: August 2020

As a necessary link for product development and evaluation, tractor testing covers new technologies in multidisciplinary fields and plays an important role in the research and development of product life cycle. This study discusses the research status of tractor test and evaluation technology and analyzes the new technology associated with the test and evaluation technology. Aiming at the problem of poor reusability, poor interoperability and weak expansion of the current tractor virtual test model, a virtual tractor-based test technology based on the architecture was proposed. The middleware technology, test data management technology, modeling technology and test environment construction technology in the tractor virtual test system were analyzed. Taking the tractor power shift transmission as an example, the application of the architecture-based virtual test system was verified, which pointed out the direction for the design verification of tractor innovative products.
Comparison and application of two time domain methods analysis to modal parameter identification of Songhuajiang River highway-railway bridge
Authors: Jin Bo , Zhu Chuankai , Yu Kunyang , Li Zhongwei , Bai Yu
Published: August 2020

In this paper, comparison and application of two time domain modal parameter identification methods of ERA and SSI in a steel truss bridge is discussed. Firstly, multidirectional comparison and analysis of structural modal parameter identification under environment excitation to the bridge are carried out. Then finite element model of the Songhuajiang River highway-railway bridge is established by MIDAS CIVIL, and the modal analysis of the structure is carried out. The first ten order modes of the structure are obtained, and some characteristics of the first ten order modes are analyzed and compared. And combining the partial trend of the finite element modal analysis, the vibration experiment of the Songhuajiang River highway-railway steel bridge under the environmental excitation is tested. Then the modal parameters of the structure are calculated, analyzed and compared through the ERA method and SSI method based on the state space model. Finally the accuracy of the two modal parameter identification methods is tested, and the feasibility of the two methods applied in the steel truss bridge structural analysis is verified.
Radius survey of crawler crane base on total station
Authors: Xu Haixiang , Qiu Jun , Wu Fengqi , Xue Jiai
Published: August 2020

The process of surveying crane parameters has been continually refined due to the competitive situation, modern surveying instruments and more powerful softwares. As the radius is the crucial parameter to determine the jib crane’s safety, a survey scheme is put forward to solve the problem that the rotary axis can’t be determined on-site in the paper, which measures the coordinate data of marked points by utilizing the total station, then the plane fitting method and the space analytic geometry method are adopted to determine the revolving centre axis. The proposed method is simple and easy to implement with acceptable accuracy in the field.
Study on the collaborative design architecture of tractor performance prototype
Authors: Wu Yiwei , Zhou Zhili
Published: August 2020

The tractor performance prototype characterizes the multidisciplinary performance properties of tractor and plays an important role in the iterative upgrade process of new product performance. In order to meet the needs of collaborative development for tractor new products, the functions of distributed design and remote interconnection, and the performance verification of product system-level design, this paper analyzes the tractor collaborative development organizations and functions from the tractor performance prototype collaborative design theory. The performance prototype collaborative design process model is established with UML, and the design supporting environment characteristics are extracted. On this basis, a collaborative design architecture is constructed, and the key technologies which include the collaborative modeling and simulation, tool integration, data management and resource platform construction are proposed and analyzed. Through the preliminary study on the collaborative design architecture of tractor performance prototype, this paper aims to provide the theory and technical mode for developing the tractor digital, networked and intelligent design system.
Research on train fingerprint positioning based on LTE-R signal strength
Authors: Luo Miao
Published: August 2020

Being aimed at improving the low accuracy when using WKNN location fingerprint based on LTE-R signal strength value, CPSO algorithm, for its advantage, is applied to optimize the weight. CPSO_WKNN location fingerprint positioning algorithm is proposed to solve the train position coordinates.Through verification by cases, WKNN weight optimized by CPSO algorithm and PSO algorithm are separately analyzed and compared, which proves that CPSO optimizes the weight of WKNN algorithm with faster convergence speed. By fingerprint spacing every 25m, 50m, and 100m, the positions of the train in tunnel environment are solved separately by CPSO_WKNN location fingerprint positioning, PSO_WKNN location fingerprint positioning and WKNN location fingerprint positioning. The simulation results show that the positioning accuracy increases with the decrease of the fingerprint spacing for any of the three positioning methods. Under the same fingerprint spacing and the same accuracy demand, the accuracy level of CPSO_WKNN location fingerprint positioning is the highest. When fingerprint spacing is 25m and CPSO_WKNN location fingerprint is applied, the probability of positioning error less than 10m is 87.8%, and the probability of positioning error less than 25m is 96%, which can meet the demand of high-precision positioning in tunnel environment.
Research on intelligent vehicle trajectory tracking based on model predictive control
Authors: Fang Yongshou , Cheng Jin , Lv Minyu
Published: August 2020

Intelligent vehicle trajectory tracking lateral control is the key technology to realize intelligent driving. Aiming at the problems that the existing control methods have a small effective control area and poor control effect under cornering conditions or small road adhesion coefficients, a model predictive control (MPC) algorithm is proposed for trajectory tracking control. Based on the two-degree-of-freedom vehicle model, a state space equation is established and discretized to obtain a predictive model that meets the conditions. Then, the corresponding objective function is designed based on the ideal yaw angular velocity under the optimal preview control theory, and the input-output constraints and side-slip angle constraints are designed according to the control and state quantities. The controller model is established in MATLAB / Simulink, and the road model is built in CarSim for joint simulation. Compared with CarSim’s own algorithm, the changes in side acceleration and steering wheel angle are smoother and less oscillating. The maximum lateral deviation and lateral acceleration are also smaller, and the lateral stability of the car is improved. It has better adaptability on pavement with lower adhesion coefficient, and can also maintain control stability. The real vehicle test results are consistent with the simulation results, with a maximum lateral error of 0.44m and a maximum heading angle deviation of 1.43 °. Therefore, the trajectory tracking control algorithm based on model predictive control designed in this paper has significantly improved control accuracy and stability, and can maintain control stability even when the road surface adhesion coefficient is low.
A HMM-based and multi-indicator driven network model for complex electromechanical system reliability analysis with considering reliability fluctuation
Authors: Li Jiwu , Gao Zhiyong , Wang Rongxi
Published: August 2020

In this paper, a new network model is developed for better expression of the interaction of a complex electromechanical system. The developed model can reflect the current reliability fluctuation followed by system state disturbances. The Failure Mode and Effect Analysis (FMEA) data and indicator data from detection and monitoring is collected and processed for the structure and parameters of this network model. Hidden Markov Model (HMM) is used for transforming indicators into the probability of fault causes. The recorded fault statistic data is considered as the prior knowledge, and the current indicator data can be used to renew the prior probability of component failure and system malfunction. With this model, the current component failure probability and system malfunction probability can be obtained.
Pole assignment PID controller based on parameter identification and its application
Authors: Lu Tong , Wu Ruliang , Zhang Jun , Liu Shouwen , Hu Fang , Guo Jiacheng
Published: August 2020

In order to ensure spacecraft qualification before the delivery, thermal tests should be performed with regard to its performance specification. The aim of thermal tests is to examine the function and performance under extreme thermal and vacuum conditions, and also to detect possible manufacturing defects or check the rationality of theoretical thermal models[1]. Temperature control of spacecraft products is one of the critical tasks in the thermal test, which has the characteristics of large thermal inertia and time-delay. Ordinary single control method often leads to poor performance or even out of control[2]. In this paper, the model of control object is identified by the least squares recursive algorithm (LSRA). According to the identified parameters and the expected pole position, three parameters of the PID controller are obtained. In order to test the control effect of this control method, representative test data is selected for simulation analysis, and the simulation effect is satisfactory. Then this control method is applied to temperature control of satellite solar array of Chang’E-1. The results show that pole assignment and the self-tuning PID controller based on parameter identification has the advantages of strong adaptability and high control precision.
Fully-digital tension control system with PID algorithm for winding ultra-fine enameled wires
Authors: Gu Zhewei , Zeng Sheng , Zhao Kaijie , Song Chenliang
Published: August 2020

An active fully-digital tension control system with PID algorithm is proposed. Only digital signals are involved and processed throughout the closed-loop control system, which employs the micro-controller unit (MCU) dsPIC33EV256GM102 as the main controller with PID algorithm, incremental photoelectric encoder as the angular sensor and AC servo motor as the actuator. A rod-spring mechanism is indispensably constructed to convert the change of tension to the variation of rod’s swing angle. Characteristics of the controlled object are tested and analyzed, from results of which the mathematical model is theoretically deduced. The PID coefficient set is determined by Ziegler and Nichols method. Its practicability is initially validated in simulation using SIMULINK/MATLAB. The prototype is also fabricated and experimented on with ultra-fine enameled wires (0.08mm). In order to enhance the practical performance, PID coefficients are further adjusted in experiments. The results show that the proposed system performs well both in transient process and steady stage. Meanwhile, it has good anti-interference capability as well.
Numerical control press design based on quantitative evaluation of appearance area features
Authors: Yuan Hao , Wu Tong , Li Mingzhu , Liang Boke , Zhang Qinglin
Published: August 2020

The appearance characteristics of numerical control presses were quantitatively evaluated using eye-tracking technology, and a numerical control press design method was proposed to provide guidance for the design of such mechanical products. By investigating and analyzing the appearance of numerical control presses locally and abroad, the modeling characteristics of these products are summarized. The interest areas of the press are divided using the hot zone map data of the eye movement experiment, and people’s knowledge of each area of the press is quantitatively analyzed. Data generated by multiple eye movement experiments are combined with a subjective questionnaire to identify the mechanics of the press. The front and work areas are the main features of the press design. Based on the experiment result, the press design is conducted based on color and modeling elements. We used the Jiangsu CPTEK numerical control press as the actual case. We also re-matched the color, optimized the details, and developed an improved design scheme, thus verifying the proposed design method.
Fault diagnosis method of rolling bearing based on the multiple features of LMD and random forest
Authors: Liu Ning , Liu Bing , Xi Cungen
Published: August 2020

The occurrence of rolling bearing fault not only affects the operation efficiency of mechanical equipment, but also leads to the safety accidents. The research on fault diagnosis of rolling bearing is of great practical significance to improve the reliability of mechanical equipment, avoid unexpected faults and ensure safety in production. In this paper, a fault diagnosis method of rolling bearing based on the multiple features of local mean decomposition (LMD) and random forest is proposed. It is suitable for processing non-stationary vibration signals generated by rolling bearings and adaptively decomposing the characteristic information excited by faults into a series of product function (PF). Then, the mixed feature vectors of each PF are constructed from different angles to realize the extraction and quantification of the rolling bearing fault feature information. Finally, combined with the random forest algorithm, accurate identification of the type of rolling bearing failure is achieved. The overall recognition rate reached 94.4%. It proves that the method proposed in this paper is effective.
Fault diagnosis of rolling bearing based on improved EMD algorithm
Authors: Meng Shuo , Kang Jianshe , Chi Kuo , Die Xupeng
Published: August 2020

The EMD (Empirical mode decomposition) is a good method to diagnose faults of equipment, but the endpoint effect and false IMF (Intrinsic Mode Function) of EMD seriously affects the effect of fault diagnosis. So this paper used an adaptive waveform matching extension algorithm to restrain the endpoint effect. To select effective IMF, moreover, this paper put forward another method which is based on information entropy and kurtosis value. Finally, the paper used the two methods combined with HHT to diagnose the bearing fault, the experimental results show that the above problems have been effectively solved and the fault diagnosis effect has been significantly improved.
Simulation for drawing process of core filled tube
Authors: Qi Junlong , Liu Xianghua , Gao Haitao , Sun Xiangkun
Published: August 2020

In this study, finite element method (FEM) was adopted to analyze the drawing process of the core filled tube (CORFT), and wall thickness and relative density of the core material were obtained. The prediction results of the FEM were compared with experimental results, revealing good agreement between them. Both the simulations and the experiments showed the existence of an ultimate relative density of the core material during the drawing of the CORFT. The influences of the process parameters on the ultimate relative density of the core material were determined using the FEM.
FEM simulation and frequency shift calculation of a quartz crystal resonator adhered with soft micro-particulates considering contact deformation
Authors: Xie Xuan , Liu Yuhong , Ye Yong
Published: August 2020

Recently some researchers studied the frequency characteristics of a quartz crystal resonator (QCR) adhered with micro-particles to measure their physical and geometric parameters. Many researchers regard the particles as rigid spheres or consider the elasticity but ignore the contact deformation and contact area of the particles. In fact, the adhesion and vibration of soft particles are coupled together and the interaction is strong and complicated. In this paper, we separately simulated the adhesion and vibration of the particles using finite element method with ANSYS software. Through transmission line model of the QCR, we get the frequency shift induced by surface particles. We found larger, softer and heavier particles produce greater contact deformation and load impedance which cause greater frequency shift (negative). The obtained results can be applied into characterization of size and elastic modulus of micro-particulates.
Theoretical and micro simulation study on cutting temperature of SiCp/Al by ultrasound vibration cutting
Authors: Yang Liang , Xu Chunguang , Fu Bohua , Sun Mingjie , Ming Liu Xiao
Published: August 2020

SiCp/Al material is isotropic and belongs to hard machining materials. Cutting temperature has a great influence on the optimization of machining process and tool life. In this paper, the analytical expression of temperature field in ultrasonic vibration turning of SiCp/Al composites is obtained by iteration of heat source method. The dynamic physical simulation model of ultrasonic vibration cutting SiCp/Al cutting temperature is established. Particles are randomly distributed in the matrix, temperature curves of particles above, middle and below the cutting path with time are analysed, the trend of the temperature curve of particles with time is that it increases first, then decreases, then increases, and finally stabilizes.
Research on the application of neuroaesthetics in industrial design
Authors: Sun Mei , Han Haocheng , Jiang Quanhong
Published: August 2020

People’s pursuit of aesthetic emotion is rising day by day, they pay attention to the practicality of products with a higher pursuit for the beauty of products. Industrial design takes the product design as core, the artistic decent expression is an indispensable link. The emergence of neuroaesthetics has laid a solid foundation for exploring the connection between individual nerves and product design. This paper introduces the history of industrial design, analyzes its development stages through comparison of different cases, and discusses the application principles of neuroaesthetics in industrial design.
Improved Elman neural network in turbine blade fault diagnosis
Authors: Zhuo Pengcheng , Xia Tangbin , Zhang Kaigan , Chen Zhen , Xi Lifeng
Published: August 2020

To remotely monitor and maintain large-scale complex equipment in real-time, it is required to create a comprehensive framework integrating remote data collection, transmission, storage, analysis and prediction. The framework is designed to provide manufacturers with proactive, systematic, integrated operation and maintenance service, where the data analysis and health forecasting are the most important part. This paper conducts health management for the turbine blades. An output-hidden feedback (OHF) Elman neural network is developed by adding a self-feedback factor in the context nodes. Thus, this improved method can increase the accuracy of the fault diagnosis for guide vane damage. Through the results, the applicability of this improved Elman neural network has been verified.
Thickness effect on pinning properties for GdBa2Cu3O7-x films deposited with RF sputtering
Authors: Xu Jianming , Xie Zhongzhou , Li Zhen , Luo Xiaojing , Zhu Yanyan , Gao Tian , Wang Ying
Published: August 2020

We studied the relationship between JC and H, direction and crystallization orientation of GBCO films grown by RF sputtering with different thickness which is 0.3 um, 0.5um and 0.9um respectively. By de-convoluting the random pinning from the correlated pinning contributions, we find that all the three films exhibit a lower effective anisotropy parameter γ = 3 rather than γ = 5 in YBCO films. The thinnest film is the most anisotropic. The anisotropic scaling analysis reveals an enhanced random pinning for thick film the whole range of angles studied in the angle correlation Jc curve. The Jc-thickness dependence analysis indicates that there is a certain threshold field Hd and a certain thickness d for magnetic decoupling.
Analysis on failure mechanism of CFRP double-tap interference-fit joint
Authors: Zou Peng , Chen Hao , Bi Xue
Published: August 2020

Composite interference-fit joints have attracted much attention because they can effectively reduce the stress concentration around the holes during loading. In this paper, the load-bearing mechanism and strength of a typical double-lap structure under static load are studied through experiment and finite element method. In order to eliminate the influence of bending moment and other factors, a special fixture was designed to study the damage failure mechanism of CFRP interference fit joint under pure tension. The finite element model of CFRP interference fit double lap structure considering both intralaminar and interlaminar damages was established with ABAQUS user subroutine and cohesive element. The damage propagation mechanism during loading process is revealed and the ultimate bearing strength is predicted by comparing the results of experiment and finite element model.
Vibration control of deployable truss antenna reflector-scanning mechanism
Authors: Hu Fei , Song Yanping , Ma Xiaofei , Duan Yuzhu , Xie Fangfang , Li Wan
Published: August 2020

Scanning mechanism and truss reflector are important components of antenna. Aiming at the mechanical system and control system composed of scanning mechanism and truss antenna, the co-simulation technology of hybrid stepping motor and flexible dynamic mechanism is proposed. Through the simulation results of the current and position changes of the antenna system, the various physical characteristics of the system during the co-simulation are studied, and the vibration characteristics of the overall antenna system are analyzed, which verifies the cooperative ability of the antenna mechanism system and the control system.
Study on surface roughness of zirconia ceramics in high efficient and precision grinding process
Authors: Wang Kechong , Li Songhua , Sun Jian
Published: August 2020

In order to solve the problem that the surface roughness of engineering ceramics is difficult to control, this paper studied the influencing factors of surface roughness of zirconia ceramic grinding. The effects of grinding depth, grinding wheel speed and workpiece feed rate on surface roughness were analyzed by the orthogonal experiments of zirconia ceramic grinding. On this basis, single factor experiments were carried out respectively, and the optimal combination of process parameters was analyzed. In addition, an empirical formula of surface roughness for the grinding of zirconia ceramics was established based on the experimental results. The results showed that the grinding depth had a great influence on the surface roughness, the grinding wheel speed effect was secondary, and the effect of the workpiece feed rate on the surface roughness was not very obvious. Compared with the measured value, the maximum relative error of the predicted value was less than 5%, which indicated that the empirical formula had a better prediction effect and provided a theoretical basis for reasonable selection of grinding parameters in actual processing.
Study on inner insulation tube for ITER axial insulation breaks
Authors: Yang Changchun
Published: August 2020

Inner insulation tube as a key component of ITER insulation break, its fabrication process was designed, and the specimen type was designed and made. Fibres and void content was tested, and thermal coefficient was measured. The results showed that it is reasonable to use R glass fibres in filament wet winding as inner tube for ITER IB because the thermal shrinking measure of this composite fabricated by this process technology is so close to the one of stainless steel 316L that it is good to reduce the thermal stress in the insulation structure of IB
Parameter identification of additional forces and torques for simulated space manipulator in zero-g simulation system
Authors: Tian Sihui , Tang Xiaoqiang , Li Yuqi
Published: August 2020

In this paper, the strain expressions a manipulator arm are established. The strain expressions affected by gravity, suspension force and torque are considered as well. The arm model is simplified as a cantilever beam, which makes the derivation more concise. In addition, the strain gauges are set on the arm to collect the strain data when the manipulator operates. The parameters of additional forces and torques are identified. And the fitting curve is very close to the experimental data.
Experimental research on laser micro-texture friction coefficient of V-clamp Mold
Authors: Mei Mei , Wu Shuqian
Published: August 2020

The friction pair between the V-clamp stamping mold and the blank directly affects the forming quality of the V-clamp. The goal of this paper is to optimize the mold friction coefficient of V-clamp with laser micro-texturing technology. To validate the texture area occupancy rate and the depth of morphological depression, the actual working condition was simulated, and the friction test was conducted. The experiment results implies that, in the case of the same morphological depression depth, the friction increase effect achieved the best with 15% texture area occupancy rate and the friction reduction effect worked best while 50%; the sample with 15% area occupancy rate and with the morphological depression depth 7.192μm had the best friction reduction effect. The research results provided a basis for surface optimization of V-clamp stamping mold.
Research on adjusting size proportion of cut tobacco
Authors: Hou Jiawen , Dong Wang Dong , Wang Deji
Published: August 2020

For solving the applicability of size proportion ofcut tobacco under the Internet environment, The device adjusting size proportion of cut tobacco needs to be developed including a feeding belt conveyor, a tobacco regulating device, a discharging belt conveyor, a guiding groove and a fixed bracket. Among these devices the feeding belt conveyor adopts two-way control of size proportion ofcut tobacco without adjusting the choice; the device adjusting size proportion of cut tobacco consists of a feed roller of tobacco, a Uniform roller of tobacco and a Cut tobacco roller, mainly by adjusting the feeding roller of tobacco, Cut tobacco roller speed difference and gap adjustment to control size proportion cut tobacco. Application test was made in Henan tobacco corporation. The results showed that: the gap between the feeding roller and the broken roller are the significant factors in proportion of long stands rate, middle stands rate, short stands rate and small particles rate. the long stands rate is positively associated with the gap, the rest are negatively correlated with the gap, ② the rotational speed of cut tobacco smoothing roller, cut tobacco feeding roller, Cut tobacco cutting roller has certain effect on, proportion of long stands rate, middle stands rate, short stands rate and small particles rate and cannot be ignored in practical work. Conclusion: This design can improve the structure of the cut tobacco through the gap between the cut tobacco feed roller and the cut tobacco break roller. How to quantify the specific effect requires special research.
An evaluation method of synthetic force engineering support capability based on multi-level grey system
Authors: Fan Jisong , Xu Jiawei , Ren Hui
Published: August 2020

Engineering support operations are characterized by diverse tasks, dispersed regions, complex command coordination, many points, long lines and wide areas. It has been difficult to model and evaluate its capability comprehensively. In this paper, according to the characteristics, the index system of support capability of synthetic Force project is constructed, and the support capability of synthetic Force project is analysed and evaluated by combining multi-level grey relational analysis theory and AHP. An evaluation method is put forward and verified by an example. Compared with the past models and methods, they are simple to operate, applicable and scientific in conclusion. It is convenient to analyze and compare the support capacity of multiple units. It can provide support and basis for the development of engineering support capacity construction and scientific assessment of synthetic Force.
Static balancing of flexural pivots with two symmetrically arranged pre-compressing springs
Authors: Yang Qizi , Bi Shusheng , Liu Tian
Published: August 2020

To overcome the spring back behavior of the flexural pivots, a novel statically balanced flexural pivot with two symmetrically arranged pre-compressing springs (SBFP-2PCS) is proposed. Five balancing design parameters and two design objectives of the SBFP-2PCS are specified. The design parameters are determined based on the stiffness analysis of the SBFP-2PCS. Samples of the SBFP-2PCS are built to verify the proposed balancing method. The test result of the average stiffness reduction is 92.5%. The proposed method is general for various flexural pivots with low axis drift.
Revised Reporting (Issuing Addenda and Amendments) in Pathology
Authors: Spiczka Amy , Waibel Liz , Garcia Edna , Kundu Iman , Kelly Melissa , Brown Ali
Published: August 2020

Objectives

The purpose of this study was to align the current experiences and best practices in revised reporting (issuing of addenda and amendments) in pathology. Pathology specialties explored in the survey include anatomic pathology, surgical pathology, cytopathology, and hematopathology.

Methods

The study used a cross-sectional design in which an online revised reporting survey was deployed to a large national sample represented by pathologists, pathology residents, pathology fellows, pathology managers, and laboratory directors.

Results

Qualitative and quantitative results from this survey highlight significant variation in standards for creating, issuing, and tracking quality indicators related to addenda and amendments. The most notable findings were a lack of standardization and the potential for widespread adoption of revised reporting best practices within and between pathology services.

Conclusions

Survey insight provides the potential for improving patient safety outcomes, engaging with consumers of our reports, providing a current state view of revised reporting, and assessing the attitudes of pathologists and laboratory professionals on how their individual approaches and team-based workflows achieve revised reports. The data generated from this survey will provide patient safety opportunities associated with accurate pathology reporting and will encourage further development of optimal pathology revised reporting guidelines.
Accurate and Reliable Diagnosis of Avascular Necrosis of the Femoral Head From Total Hip Arthroplasty Specimens Requires Pathologic Examination
Authors: Dermawan Josephine K , Goldblum Andrew , Reith John D , Kilpatrick Scott E
Published: August 2020

Objectives

To evaluate the necessity of pathologic examination for confirming the diagnosis of avascular necrosis (AVN).

Methods

We retrospectively reviewed consecutive nonfractured total hip arthroplasty cases (n = 1,722), comparing operative diagnoses and radiologic data with final histologic diagnoses, focusing specifically on AVN.

Results

Among 199 histologically confirmed cases of AVN, 62 (31%) had a preoperative diagnosis of osteoarthritis/degenerative joint disease (OA/DJD); 58 of the latter patients had radiology reports, but only two (3%) documented AVN. Patients with AVN preoperatively diagnosed as OA/DJD were significantly older (mean, 65 years) than patients with AVN correctly diagnosed clinically (mean, 52 years; P < .00001). Among 163 cases with a preoperative diagnosis of AVN, 26 (16%) were confirmed as OA/DJD; the radiology report incorrectly diagnosed AVN in 17 (65%) patients. These latter patients also were significantly older (mean, 60 years) than patients with AVN correctly diagnosed clinically (P = .0008). Patients with a preoperative clinical and/or radiologic diagnosis of AVN were more likely to be younger and have known AVN risk factors.

Conclusions

Accurate and reliable diagnosis of AVN requires pathologic examination, especially among older patients without known risk factors. Prompt diagnosis may lead to behavioral changes in affected patients that reduce the risk of subsequent lesions.