bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-assembly of Pt nanoparticles and their localized surface plasmon-enhanced effects on the optical properties of the polymercrystalline ZnO thin films
Authors: Yang Weijia , Liu Junjie , Liu Mingquan , Liu Yanyi , Wang Nuoyuan , Shen Gengzhe , Liu Zhihao , Chen Mei
Published: October 2019

In this work, we report that Pt nanoparticles are self-assembled by annealing Pt thin films grown on Si (100) substrates at a high temperature. After growth of Pt thin films, annealing treatment is carried out at 700 and 850 °C respectively, under high purity nitrogen environment. It is found that Pt nanoparticles are formed at annealing temperature of 700 °C, while larger sized and high-quality crystalline Pt nanoparticles are generated at an elevated temperature of 850 °C. It is also found that Pt nanoparticles present plasmon enhanced effect on the optical properties of the polymercrystalline ZnO thin films, and Pt nanoparticles prepared by 20s sputtering time leads to about 5 fold excitation enhancement compared to that without Pt nanoparticles.
Failure analysis on 12cr1mov steel tube of high temperature reheater for 600 mw subcritical boiler
Authors: Wang Jia’an , Zhang Ruichen , Shi Yan , Song Zhongxiao
Published: October 2019

A 600 MW subcritical boiler high temperature reheater tube of 12Cr1MoV steel leaks after running for 11×104 h. Failure Analysis of the high temperature reheater is studied by optical microscope (OM), scanning electron microscopy(SEM) and energy dispersive spectroscopy(EDS), etc. The results show that under long-term service at high temperature, the alloy elements have been depleted in the matrix. The oxidation layer of the inner wall is too thick, and the micro-structure is degraded obviously. Many creep cavities and micro-cracks appear in the fire-facing side of the elbow. The micro-cracks extending along the grain boundaries are filled with oxide. In conclusion, the degradation of the microstructure caused by long term overheat is the main reason for the failure of 12Cr1MoV reheater tube, and the creep cracking causes the leak.
Steel stress monitoring analysis for water pressure test of spiral case
Authors: Wu Hao , Wu Xueyi , Zhu Zhaohui
Published: October 2019

Taking the water pressure test of Hohhot Pumped Storage Power Station as the research object, the steel stress was analyzed by monitoring data of 3# spiral case. It could be found that the change of steel case stress was closely related to the change of water pressure, multi-correlation coefficients were between 0.993 and 1.000. The largest steel stress (194.65MPa) was less than steel yield strength (610MPa) when the spiral case was faced to the largest inner water pressure. When the inner water pressure was up to holding pressure (3.24MPa), stress of spiral case was 20.73MPa. Under same water pressure, the stresses of up and down socket ring were 1. 1∼1.8 times as much as others in same section. When the largest inner water pressure was transmitted to the spiral case, 3.24MPa internal water pressure was endured by spiral case and 3.36MPa pressure was shared by spiral case and unit concrete. The results show that stress change of 3# spiral case is normal and steel is worked in the elastic range.
Study on gravity calculation method of integration about an upper extremity exoskeleton and loads
Authors: Feng Lin , Song Qiuzhi , Qi Zhuo , Wang Xin
Published: October 2019

The gravity center of integration about the upper extremity exoskeleton and loads has a great impact on the balance control of the systemic exoskeleton system. In this paper, a new method is presented to calculate the gravity of the integration. First, build a model of the upper extremity exoskeleton by standard D-H method, analyze the model by kinematics and then obtain the function of the gravity center by analyzing the relationship between the structure parameters, joint angles and gravity center of the integration. Second, simulate each curve of the gravity center with lifting the load of 0, 10KG and 20KG under a specific trajectory determined by cycloid interpolation method. This paper lays a foundation to study on the balance control of the systemic exoskeleton system.
Research and Application of Screw Feeding Mechanism for Fiberboard Separation
Authors: Ling Lu
Published: October 2019

The main function of the screw feeding mechanism is to force the cooked wood fiber material into the high pressure, high temperature and high humidity grinding chamber for fibrosis heat treatment, which is an important part of the fiberboard fiber separation feeding equipment. Through the analysis of typical screw feeding mechanism, combined with production performance requirements, the improvement measures are put forward and the structure of main functional components is determined, and the design scheme of screw feeding mechanism for fiberboard fiber separation is formulated, so as to effectively improve the feeding efficiency.
Design and research of a high speed small piezoelectric turntable
Authors: Xue Shan , Lv Nanfang , Guo Jianbo , Liu Zhengbin , Meng Xianyu
Published: October 2019

In order to achieve fast target locking and tracking in imaging system, a high-speed small piezoelectric turntable is designed. The piezoelectric turntable is driven directly by piezoelectric motor and has compact structure, which can realize high-speed rotation of imaging system. According to the index, the structure of piezoelectric turntable is designed, and the three-dimensional model is built by SolidWorks software. After simplifying the model, the finite element model is built by ANSYS software, and the static analysis of the turntable is carried out. Different materials were used to design the turntable, and their mass is compared. It is determined that the mass of the turntable with new materials is the lowest. The static analysis of the turntable with new materials shows that the designed turntable meets the design requirements of stiffness and strength, which provides a reference for the design optimization of similar turntables.
Hypolipidemic Effects of Polysaccharides from Fermented Seaweed
Authors: Wang Zhongjian , Su Yue , Li Kunlun , Zhao Lin , Liu Xinli
Published: October 2019

To study the hypolipidemic effect of a fermented seaweed polysaccharide on experimental hyperlipidemic mice for Conducted a series of work. Algal polysaccharides can alleviate hyperlipidemia and decrease risks of atherosclerosis and cardiovascular diseases. This study aimed to investigate effects of algal polysaccharides fermented by Yeast and Lactobacillus plantarum on hematic fat level of mice fed with high fat diet. Forty mice were randomly assigned to four groups: normal control group (NC), high-fat control group (HFC), high concentration of seaweed polysaccharide (HSP), low concentration of seaweed polysaccharide (LSP), respectively. The NC group was fed with the basic diet, while the other groups were fed with high-fat diet. After the experimenta period (4W), mice were sacrificed by decapitation. Results demonstrated that fermented algal polysaccharides could regulate lipid levels, the increase in HDL-c and decrease in TG, TC and LDL-c. In conclusion, algal polysaccharides fermented by Yeast and Lactobacillus plantarum may has effect of hypolipidemic.
In Vitro Hypoglycemic Potential of Dietary Fiber From Fermented Seaweed
Authors: Zhou Lin , Zhao Lin , Su Yue , Li Kunlun
Published: October 2019

Dietary fiber can regulate metabolic activity of the body by affecting enzyme activity in the intestine. It cut down the speed of digestion to relieve the release of glucose, so blood sugar can be controlled in the optimal range. In this study, seaweed was used to prepare dietary fiber by microbial transformation of Lactobacillus rhamnosus and Lactobacillus plantarum. The experiment showed that the content of soluble dietary fiber (SDF) increased significantly after the action of the mixed lactic acid bacteria, and the increments rate was 21.1%. The inhibition rate of α-amylase and α-glucosidase increased by 25.9% and 16.6% respectively after fermentation. Therefore, after fermentation seaweed can enhance the soluble dietary fiber and improve inhibition rate of enzyme activity related to digestion. Dietary fiber of seaweed has potential of hypoglycemic.
Preparation and Mechanical Properties of Short Carbon Fiber Networks Reinforced Anionic Polymerized Nylon 6 Composites
Authors: Li Hongyu , Li Wei , Fei Youqing , Guo Wenxun
Published: October 2019

Short carbon fiber three-dimensional network reinforcement (SCFNR) was prepared by bonding two different lengths of short carbon fibers (SCF) with phenolic resin powder (PF), and then carbonized at 800 °C. Two kinds of SCFNR/anionic polyamide 6 (APA6) composites were fabricated via vacuum assisted impregnation process (VAI). The microstructures and mechanical properties of the composites were characterized by scanning electron microscopy and universal testing machine. The thermal stability of the composites was evaluated by thermogravimetric. The results show that the carbonized phenolic resin can effectively bond SCF to form a rigid three-dimensional network reinforcement, both types of SCFNR can significantly improve the mechanical properties of the composites. The maximum thermal decomposition temperature of SCFNR/APA6 composite prepared with the carbon fiber length of 1 mm is 150 °C higher than that of APA6
Culture Conditions and Optimization of Glutathione - producing Yeast Fermentation Tank
Authors: Ming Sui , Zhang Yang , Rong Jiachao , Zhu Keyong , Hua jian , Zhou Rong-qing , Li Guoying
Published: October 2019

In this paper, yeast was used as the starting strain, and the obtained strain was inoculated in 5L fermentor by plate, slope and seed culture. The fermentation temperature, fermentation time, rotation speed and ventilation condition were changed by single factor experiment. The content of glutathione was determined by high performance liquid chromatography (HPLC). Finally, the optimum amount of biomass accumulation and target product accumulation were obtained. condition.
A Unique Settling Pattern for Two Circular Particles Having Different Densities
Authors: Shan Xiaopeng , Nie Deming
Published: October 2019

In this work the sedimentation of two circular particles having different densities in a vertical channel has been numerically studied using the lattice Boltzmann method (LBM). The case of a single particle settling in a narrow channel has been simulated to validate the computational code. The relationship between the Reynolds number and the particle-to-fluid density ratio was presented. For the case of two particles, a unique pattern of motion, represented by the process of “drafting-kissing-oscillating-separating”, has been revealed. The vortex structures along with the particle displacements are shown to illustrate this pattern.
Novel Biodegradable Antimicrobial Composite Scaffold by Coating Type I Collagen Scaffold with Pepsin-Degraded SIS Extraction
Authors: Zhong Risheng , Chen Xin , Dai Yao , Xia Leilei , Men Fumin , Zhao Bo , Chen Yi , Liu Hairong , Zhou Zheng
Published: October 2019

The antimicrobial activity of tissue engineering scaffolds is crucial for successful implantations and surgeries by reducing surgical infections. In this study, small intestinal submucosa (SIS) extracts were prepared by in vitro pepsin digestion (pSIS) and its antimicrobial active is stronger than those prepared by accelerated hydrolysis (aSIS). Compared with aSIS, the average molecular weight of pSIS seems smaller with more narrow distribution via SDS-PAGE electrophoresis combined with commassie blue staining. Furthermore, pSIS coated porous type I collagen scaffold (pSIS/COL I scaffolds) displayed a strong antibacterial activity and is suitable for cell seeded and growth, indicating that it can be potentially applied to tissue engineering or surgical tissue repairing in the future.
The Simulation of Electromagnetic Fields with Large Wavelengths
Authors: Wang Chunsheng , Wu Shibin , Shang Dongxing , Li Xueai
Published: October 2019

When the wavelength of an electromagnetic wave is much larger than the microscopic size of the material, the numerical solution of the model to study the effect of the material microstructure on the electromagnetic wave propagation usually fails to be obtained due to computational overload. In this paper, a method using a large-scale simulated structure instead of the real microstructure has been proven. With the simulated structure, the computational load is greatly reduced, and the numerical solution can be obtained. Furthermore, the simulated structure conditions needed to achieve an effect on the electromagnetic wave propagation equivalent to that of the real microstructure were studied.
Development of a new design method for composite pavement structure
Authors: Shi Ning , Su Huan
Published: October 2019

HMA/PCC composite pavement is a new type of durable pavement structure which is a rigid-flexible combination. The composite pavement structure with excellent design has better durability. However, due to less domestic use, there is no effective structural combination design method in china. In this paper, a new structural design method of HMA/PCC composite pavement is put forward, in which the maximum thickness of asphalt concrete is designed according to the allowable permanent deformation, and the lower limit of the thickness of asphalt concrete is designed with the allowable shear stress of bond layer as the index. The composite slab model was used to design the thickness of concrete layer.
The effect of walnut processing by-product filler on properties of plywood
Authors: Li Jing , Xu Shanfeng , Zhang Jialin , Luo Xing , Jiang Ke , He Xie , Chen Yuzhu , Xiao Hui
Published: October 2019

In this study, walnut processing by-product was served as filler to make three-layer plywood, and the physical-mechanical properties were also discussed. The results showed that the formaldehyde emission of plywood corresponding to walnut shell and walnut dregs decreased by 0.0542 mg/L and 0.066 mg/L, respectively. The properties of plywood filled with walnut dregs are better than that of walnut shell filler, and the formaldehyde emission of the corresponding plate is lower. At the same time, compared with flour, the wet bond strength of walnut shell plywood increased by 0.0332 MPa, and that of walnut dregs plywood decreased by 0.123 MPa, but they all met the national standards.
Cerebral Infarction Rehabilitation Evaluation with Posture Analyses
Authors: Fan Yutian
Published: October 2019

A cerebral infarction is a brain illness caused by a blockage in or narrowing of the arteries that supply blood and oxygen to the brain. The restricted amount of oxygen to the brain results in varying levels of disorder in the limb function of patients, severely affecting their normal lives. For cerebral infarction patients, physical rehabilitation is crucial in the early stage of their illness. The correct instruction of rehabilitation exercises can effectively restore the patient’s limb function, reduce the chance of reoccurrence and improve the patient’s daily life. In order to provide cerebral infarction patients effective early treatment, this project strives to develop a motion evaluation model based on deep learning. In order to enhance the instruction of rehabilitation exercises, the project’s model defines 6 standard exercises as training input. It then employs the python Openpose framework to extract the coordinates of 18 joints of the human body, and traces the trajectory of these 18 joints when a person carries out one of the standard exercises. The trajectory of the joints during the exercise is used to train the LSTM network. The final model can be used as a guiding model for rehabilitation training.
Effect of Y2O3 on physical and mechanical properties of TiAlbased alloys
Authors: Wang Che , Yang Liying , Wang Shouren
Published: October 2019

Ti-45Al-5Nb alloy powders were used as the matrix, and added different contents of Y2O3. The TiAl-based alloys with excellent mechanical properties were prepared by vacuum hot pressing sintering technology. Analysed the effect about Y2O3 on the properties of the alloys. The results show that trace amounts of Y2O3 can effectively improve the physical and mechanical properties and refine the grain size of the alloys. When 0.25% Y2O3, the TiAl alloy exhibits excellent hardness, density, flexural strength and fracture toughness. TiAl-based alloys are mainly composed of brittle fracture.
Multiple regression model for identification of material concentration and color reading
Authors: Zhang Hanping
Published: October 2019

According to the experimental data, the color dimensions of different concentrations of five substances were analyzed, and reasonable data was selected to analyze the correlation between concentration and color readings. The quantitative relationship model between material concentration and color reading was established by multiple regression. Considering the autocorrelation of the variables, a one-dimensional regression model of concentration and gray scale was established for sulfur dioxide. The two models were tested and were significant with minimal error. This method can be extended to measuring the concentration of the substance In practice.
Rolling bearing fault diagnosis method based on local tangent space arrangement and VMD decomposition
Authors: Zhang Yanan , Tong Qingbin
Published: October 2019

In this paper, a method based on LTSA and VMD is proposed to effectively extract fault feature information of rolling bearing. The selection of reduced dimension d and neighborhood selection parameter k in LTSA adopts grid search method. Taking the fault characteristic energy ratio (FER) as the objective function, a set of optimal parameters is determined as the input parameter of the manifold learning algorithm. Variational modal decomposition (VMD) is used to denoise signal. The kurtosis value, correlation value and envelope entropy value are comprehensively evaluated, and the optimal component is selected for reconstruction. The optimal component of reconstruction is analyzed by envelope spectrum to realize fault diagnosis. The proposed method is applied to the fault measurement signal. The results show that the proposed LTSA-VMD fault diagnosis method has obvious advantages in signal denoising and fault feature extraction.
High-Throughput Sequencing of Plasma Free DNA In the Second Trimester for Non-Invasive Prenatal Testing of 21-Trisomy Syndrome
Authors: Fu Xiao , Li Mu , Wen Ping
Published: October 2019

Objective: To investigate the application of fetal free DNA (cff DNA) in the peripheral blood of pregnant women to the diagnosis of non-invasive prenatal bowel syndrome (21-trisomy). Methods: 1735 cases of single-pregnant pregnant women with 12-24 weeks of pregnancy were collected, and peripheral blood DNA was extracted. The new generation high-throughput sequencing technology was used for detection and bioinformatics analysis, and amniotic fluid or umbilical cord was selected for 21-three high-risk pregnant women. Blood karyotype analysis was performed. Result: In the 1735 specimens, 12 cases of 21-trisomy positive samples were detected by the new non-invasive prenatal technique, and 12 cases were confirmed by karyotype analysis. The sensitivity and specificity of the non-invasive prenatal technique for the 21-trisomy detection were 100%. Conclusion: The clinical non-invasive prenatal 21-trisomy diagnosis of cffDNA has broad application prospects in prenatal screening.
Global buckling of composite laminated box beam
Authors: Zhu Xiujie , Xiong Chao , Yin Junhui , Yin Dejun , Deng Huiyong
Published: October 2019

Based on the theory of first-order shear deformation beam, the equivalent constitutive Eq. of composite laminated box beam is established. The analytical formula of equivalent bending stiffness and equivalent torsional stiffness characterized by the stiffness coefficient of laminated plates are derived. The critical loads of bending instability and torsional instability are obtained by solving the integral buckling equilibrium differential Eq. of composite laminated box beam under axial load. The variation of critical load under different ply layers and different ply angles is analyzed.
Influence of Filler Wire Feed Speed on Microstructure and Properties of MIG Welding of 7005 Aluminum Alloy
Authors: Zhang Xiang , Xie Dejie , Chen Bo
Published: October 2019

Metal inert-gas welding (MIG) test was carried out using ER5356 welding wire as filler metal and 7005 aluminum alloy plate as base material. Different welding samples were obtained by changing the filler wire feed speed, and their microstructure and mechanical properties were observed and tested. The results show that the MIG welding joint of 7005 aluminum alloy usually consists of 3 parts: welding metal, heat affected zone and base material zone. The lowest hardness of the MIG welding joint is in the weld seam, which is the weakest position of the welding joint. The largest tensile strength of all the test samples is 303Mpa, which is 76.3% of the tensile strength of the base metal. The tensile fracture mode of all the test samples is dimple fracture, and the dimple fracture of the sample with a filler wire feed speed of 9.8m/min is small and dense, with the deepest depth of all the samples.
Research on synthesis and properties of room temperature curing polyurethane damping materials
Authors: Zhou Haijun , Zhou Mengmeng , Zhang Xiaolei , Chen Xiaoqi , Yang Shulan , Li Yantao
Published: October 2019

Room temperature curing polyurethane (PU) damping materials were synthesized with PU prepolymer and self-made curing agent. The prepolymer was synthesized from poly (neopentyl adipate) with higher side methyl content and toluene diisocyanate. Effects of molecular weight of poly (neopentyl adipate) and curing agent types on mechanical properties and damping properties of PU damping materials were investigated. Results showed that tensile strength of room temperature curing PU damping materials is 22.4MPa and the tan δmax reaches 1.10. The damping temperature range of tanδ>0.3 is more than 60°C, which is a kind of damping material with excellent comprehensive properties.
Design of dual narrow-band terahertz absorber based on metamaterials
Authors: Ren Zhongru
Published: October 2019

Metamaterial-based absorbers are a new kind of synthetic electromagnetic materials. Because of their small thickness, easy manufacture and stable performance, they are widely used in electromagnetic wave detection in different bands. Based on the principle of equivalent LC resonant circuit, a dual-band narrow-band absorber in terahertz band is designed in this paper. The frequency domain solver based on CST software is used to study the absorption characteristics of the absorber in terahertz band. The relationship between changing different system parameters and optimizing the absorption rate and adjusting the position of resonance absorption peak is analyzed in detail. It has certain guiding significance for the detection of terahertz wave and the fabrication and optimization of terahertz wave absorbers, filters and resonators.
Effect of Tb Content on The Electrical Properties of Double Perovskite Oxide Pr(2-X) Tbxcomno6
Authors: Li Xiaoxin , Xing Ru , Zhao Jianjun
Published: October 2019

Polycrystalline samples of double perovskite oxide Pr(2-x) TbxCoMnO6 (x=0,0.05,0.1,0.15) were prepared by traditional high temperature solid phase reaction. The structure and electrical transport properties of the samples were investigated by the relationship between the XRD lines and the resistivity of the samples ( ρ -T curve). The results show that all the samples show good single-phase, belonging to monoclinic system, space group is P21/n; the samples are all semiconductor materials; the existence of magnetic field is not conducive to electrical conduction; compared with other samples, the samples with x=0.1 and x=0.15 had better conductivity. The samples in the measured temperature region all follow the way of electrical conduction of variable-range hopping.
Properties of New Two-Dimensional Nanomaterial Black Phosphorus
Authors: Bao Xizhong
Published: October 2019

Two-dimensional (2D) materials have attracted broad interest because of their low-dimensional effect, and black phosphorus has become a member of them due to the successful preparation. Phosphorus has several allotropes, white phosphorus, red phosphorus and black phosphorus. Black phosphorus is most thermodynamic stable in them. Black phosphorus was obtained by a phase transition from white or red phosphorus at high pressure and high temperature. It is a natural p-type semiconductor in which each layer is vertically stacked by the van der Waals force. The thickness of black phosphorus can be scaled down to the atomic layer scale known as phosphorene by mechanical exfoliation or liquid exfoliation. Compared with black phosphorus, phosphorene’s physical properties have significant changes. The band gap in bulk black phosphorus is 0.3 eV and can be expanded to 1.0 to 1.5 eV depending on the layer numbers. Nevertheless, the poor chemical and structural stability of black phosphorus and phosphorene raises important concerns. In the past century, the synthesis, physical properties, and device applications have been extensively investigated in various studies. In this review article, a lot of references of black phosphorus are cited to introduce systematically the research progresses of structure and preparation, the study of material properties and device performance, the chemistry of the degradation process and the anti-degradation treatments. At last, the development trend of phosphorene is mentioned.
Fabrication and optical properties of InP/Cu2O nanojunctions
Authors: Li Qiang , Dai Kai , Li Hong , Zhang Min , Zhu Guangping , Zheng Maojun
Published: October 2019

The InP/Cu2O nanojunction hybrid materials are fabricated by a facile method via electrodeposition of CU2O nanoparticles on the ordered one dimensional InP nanopore arrays. The morphology and element composition of the InP/Cu2O heterostructures are characterized. Experimental results indicate p-type Cu2O nanoparticles homogenously covered on the surface of n-type InP nanopore arrays and formed efficient heterogeneous structure. Compared to the pristine InP nanopore arrays, the InP/Cu2O nanoheterojunction structure have advantageous of the separation of photogenerated electron-hole pairs.
Chemical Looping Method for Production the Feed Gases of Ammonia Synthesis: Thermodynamics
Authors: Wang Qi , Wang Kun , Hua Jialiang , Peng Ruijie
Published: October 2019

This work proposes a chemical looping method to achieve the coproduction of N2 and H2. The system include a fuel reactor, a H2 generator and a N2 generator. Thermodynamics analysis is carried out to evaluate the feasibility of this method. In the fuel reactor, when the reaction temperature is 1000°C, 1.067kmol Fe and 0.851kmol FeO can be transported to the H2 generator and 2.991kmol syngas is produced. In the H2 generator, when the reaction temperature is 500°C, 0.223kmol Fe, 0.485kmol FeO and 0.425kmol Fe3O4 can be transported to the N2 generator and 1.250kmol H2 is produced. In the N2 generator, when the reaction temperature is 600°C, 1kmol Fe2O3 can be transported to the fuel reactor and 1.484kmol N2 is produced.
Fermentation Optimization of Bacillus Licheniformis
Authors: Ming Sui , Zhang Yang , Guan Yonglin , Li Chunming , Shu Xuexiang , Rong Jiachao , Zhou Rongqing , Li Guoying
Published: October 2019

Optimizing the fermentation conditions of Bacillus licheniformis and increasing the yield of Bacillus licheniformis to better serve agriculture is a very important research. The purpose of this experiment was to investigate the optimal fermentation conditions for increasing the production of Bacillus licheniformis. Through a series of investigations on Bacillus licheniformis, the system has learned the optimization method of the culture medium and the analysis method of the experimental data, and strengthened the basic experimental operation skills to lay the foundation for future experimental exploration.
Prediction of SINS/GPS Navigation Information by ELM Algorithm during GPS outages
Authors: Cao Yang , Jia Fangxiu , Jiang Xun , Zhang Qing
Published: October 2019

SINS/GPS integrated navigation has received great attention recently due to its impressive navigation accuracy on missile-borne platforms. However, it remains an ongoing challenge to address the problem of GPS signal loss. Furthermore, the limited space and power consumption of a projectile have made it challenging to carry out time-consuming iterative calculations. In this paper, ELM is proposed for the first time to predict the navigation information on the missile-borne platform for its simpler neural network structure and no iterative calculation. Comparing it with the algorithms of BP and GABP, the simulation results reveal that the ELM algorithm is more time-saving with higher prediction accuracy than the others. More importantly, the number of parameters needed to be set is much less than those of the other two algorithms, which is beneficial for its practical application.
Intelligent contract design based on block chain in logistics management
Authors: Yang Ping , Yang Xiaolei , Li Jianwei
Published: October 2019

Although the logistics management has been improving, the information management is still stagnant. The renewal mechanism of logistics information is the basic requirement of logistics system, but it is more important to solve the trust problem of logistics information. It is good for improving the logistics management to design a verifiable information management mechanism which can help relevant participants establish trust relationships. This paper analyzes the development status of block chain technology, then a decentralized and self-verifiable system management program model is designed. Finally, the application is implemented based on the intelligent contract design of Ethereum block chain.
Simulation Analysis of the Vibration Isolation Performance of Elastic Mounting bracket for Hydraulic Pipeline
Authors: Cai Biaohua , Wang Haisheng , Xiao Longzhou
Published: October 2019

The dynamic characteristics of hydraulic pipeline elastic mounting bracket directly affect the vibration and noise characteristics of pipeline system, as well as the strength and fatigue life of the mounting bracket itself. The modeling and simulation method of rubber elastic mounting bracket for hydraulic pipeline is studied by using non-linear finite element analysis method. The validity of this method is proved by an engineering example. At the same time, the analysis results show that the use of flexible rubber mounting bracket in hydraulic pipeline system has a good effect on isolating high-frequency noise, and the exciting forces of higher frequency in pipeline has a significant attenuation when it is transmitted to the base.
Acceleration of Target Detection Based on Forced Knowledge Distillation
Authors: Wen Jing , Gong Chenggui
Published: October 2019

In recent years, deep learning has achieved outstanding results on many problems such as computer vision, natural language processing and so on. The research of network model compression and acceleration can make the network model run efficiently on resource-constrained devices by greatly reducing the amount of computation of the network when the performance of the network decreases slightly. At present, knowledge distillation has achieved good results in classification tasks, but it shows strong limitations in the face of more complex tasks like detection. In this work, we propose a forced knowledge distillation framework, which focuses on improving the ability of feature extraction in detection. The whole model can be compact and fast without losing much accuracy. We use PASCAL VOC, KITTI and MSCOCO data sets to make a comprehensive evaluation. The results show that the forced knowledge distillation framework can fully learn the knowledge of teacher networks and achieve better detection results in smaller student networks.
Application of A New Firefighter Protective Clothing Material in Fire Rescue
Authors: Wu Chuansong
Published: October 2019

Firefighters are usually exposed to high temperatures, smoke and other hazards from the environment when carrying out fire fighting and rescue. Fire fighting clothes are special protective clothes used to protect firefighters from high temperature and fire damage. PPS fabrics can meet the basic requirements of fire service coatings. According to the standard requirements of a pair of firefighters’ chemical protective clothing, this topic further coats the surface of PPS fabric to achieve a certain chemical penetration resistance, and does basic research on the application of PPS fibers in the outer layer of chemical protective clothing. It can be used to make exterior material of Fire Fighting Protective clothing. Fabric density affects the warp and weft tear properties, but due to the limited fabric density in this design, the density does not affect much. In addition, it has been found that reducing the latitude and longitude density difference can increase the latitudinal tear strength value. The possibility of multi-stage airbag cushioning type pressure-proof protective clothing captured in actual fire-fighting and rescue work is analyzed, which provides a certain guarantee for the safety of fire-fighters during fire-fighting and rescue operations.
Mechanical Analysis of Rolling Mill Support System Based on ANSYS-Workbench
Authors: Song Xuan , Zhang Gang , Chen Hong , Sun Lin
Published: October 2019

In the rolling of four-roll mills, there are often damages in bearing such as the burning and adhesion failure. Domestic and foreign scholars have done a lot of calculations and experiments on this, and believe that when the support system of the roll neck (roll neck, bearing and bearing seat) suffers the roll bending force, the four-row cylindrical roller bearing suffering the radial bending force may be eccentric due to the hyperstatic structure of the mechanism in which the bearing block cannot be synchronously bent with the roller neck, thereby causing bearing damage. In this paper, the integrated model of the roll neck support system of the roll is established by SolidWorks, which is introduced into ANSYS-Workbench for contact surface setting, loading and constraint, and finally the roll neck bending deflection and bearing roller contact stress are analyzed and verified, which confirmed the validity of integrated deformation and mechanical analysis of roll neck support system by finite element method.
Application and Implementation of CNN in Artillery Countermeasure Training System
Authors: Chen Dong , Yang Chuandong , Ji Hang , Jiang Bin’an , Liu Zhen
Published: October 2019

Blasting point recognition is the basic task in artillery countermeasure training system. In order to solve the inefficiency and inaccuracy caused by manual recognition, this paper proposes a blast point area recognition algorithm based on convolution neural network. Aiming at the relatively small area of blasting point, the design idea of transfer learning is adopted. Firstly, based on the Mask-RCNN model, the structure of feature pyramid network is modified. By comparing the recognition effects of different feature fusion methods, the optimal one is selected. The anchor parameters are adjusted according to the target characteristics as well. Finally combining the mask branch network and the target detection network, the contour of the blasting point area and the center of it are calculated. The experimental results show that the method proposed in this paper achieve 97.6% mAP on the blasting points test dataset we built at 4.7 FPS, which solved a basic problem in artillery countermeasure training system well.
Research on Vibration Reduction of a Squeeze Film Damper
Authors: Liu Jun , Wang Xiaojing , Chen Chao , Zhu Caizhi , Zheng Jiaqi
Published: October 2019

With the trending to high speed, high precision and heavy load of large-scale rotating machinery, the problem of dynamic instability of rotor-bearing systems has become increasingly serious. In this paper, a dynamic model of squeezed-film damper-journal bearing-rotor system was established and the influence of different stiffness and damping on rotor response was analyzed. Three kinds of squeeze film dampers with different stiffness and damping were designed to be tested under various conditions. The signals of acceleration amplitude of bearing seat and rotor displacement were acquired, processed and analyzed. The experimental results show that there is a significant decrease in vibration response and acceleration amplitude of the bearings embedded with SFD compared to journal bearings without SFD. In addition, the greater the damping value of SFD, the smaller response of rotor. Stiffness has less effect on vibration reduction compared to damping which is basically consistent with the theoretical analysis.
Analysis of The Role of Ceramic Green Body Enhancer (C3h3nao2) N in Art Ceramic Molding
Authors: Yan Shen , Fang Yu
Published: October 2019

Using (C3H3NaO2) n as a dispersing agent, an alumina art ceramic slurry having good dispersibility and suspension stability is obtained. The effect of the addition amount of (C3H3NaO2) n on the viscosity of alumina art ceramic slurry and the influence of solid content on the blanking time, mold release performance and shrinkage of the green body were analyzed. The results show that (C3H3NaO2) n can effectively improve the forming strength of the art ceramic body and reduce the deformation rate of the green body. When the mass fraction of the reinforcing agent c is 0.6%, the drying strength of the green body increases by 167.5%. The deformation rate of the blank is reduced from 50% to 10%.
Research and Analysis on Quality Control of Concrete Raw Materials in Construction of Road and Bridge
Authors: Song Tianjiao
Published: October 2019

By introducing the contradiction of concrete construction quality control, the main points of concrete construction quality control, concrete mix design considerations, concrete mixing, transportation, on-site acceptance quality control points, bridge concrete construction control key points, issues that need to be highlighted, etc. Eliminate or reduce common quality problems, identify quality hazards, use FMECA technology to analyze failure modes and impacts in all aspects of prestressed road and bridge construction process, after process combing, failure mode determination, failure cause analysis, failure mode for road bridge concrete, The impact of safety and other aspects of judgment, to remind engineering construction and technical personnel to start from the details, to do a good job in the quality of bridge engineering.
Study on Lubrication and Friction Performance of Grease Lubricated Sliding Bearings
Authors: Sun Yuanyuan
Published: October 2019

In order to study the friction performance of grease lubricated sliding bearings of construction machinery under long-term radial heavy load, a bearing testing machine was developed to measure the changes of friction force, friction coefficient and temperature rise of such bearings. The testing machine can not only simulate the operation process of bearings under low speed and heavy load conditions, but also evaluate the operation state of grease during grease lubrication. Through durability tests on bearings designed and produced by three different manufacturers, the friction coefficient between bearings and pin shafts can be accurately obtained, the current lubrication and wear conditions of bearings can be detected, the advantages and disadvantages of bearing performance can be judged, and at the same time, reference can be provided for designers to estimate bearing life and optimize design.
Future Prospects of UAV Tilt Photogrammetry Technology
Authors: Ren Jinghong , Chen Xuan , Zheng Zhangzhe
Published: October 2019

In recent years, China’s science and technology have developed rapidly, and the surveying and mapping industry has also made great breakthroughs. Traditional aerospace photogrammetry cannot collect more accurate information from modern surveying and mapping. In recent years, UAV tilt photogrammetry technology has been developed. UAV tilt photogrammetry technology can more realistically reflect the position and appearance of features. Traditional aerospace photogrammetry can only perform vertical data acquisition, but tilt photogrammetry can perform fast and efficient data acquisition from different angles. Not only that, tilt photogrammetry has greatly improved the image matching and measurement technology. This paper analyzes the future development trend and application fields of the development of tilt photogrammetry technology.
Magnetic array knitting needle driving system design
Authors: Zhang Chengjun , Li Dongdong , Zuo Xiaoyan , Zhou Xiangyang
Published: October 2019

The traditional needle driving in knitting machine has drawbacks, such as vibration, noise, temperature rising, high energy consumption, and so on. A new non-contact magnetic array needle driving method is proposed in principle, which completely overcome traditional mechanical cam driving shortcomings. The permanent magnet together with knitting needle as the permanent knitting needle, the control system real-time controls the electromagnet coil current direction and value, which can generate different magnetic force to drive the needle movement. The magnetic array needle driving structure and its DSP control system are designed, the mathematic model is analysed, and the experiment and simulation are applied. By comparing the experiment and simulation, the control system is verified to satisfy the new knitting needle driving.
Design and exploration of an apple sorting baler
Authors: Luo Zhun , Ma Lihua , Zhou Zhonghua , Jia Senjun , Fu Zongguo
Published: October 2019

The packaging classification for the more vulnerable objects such as apple is only at the stage of manual classification, which is not only time-consuming and laborious, but also cannot accurately sort apples. Therefore, a design scheme of apple sorting and packaging machine is proposed. The structure of the machine and the functions of each part are systematically expounded. The functional modules of bad fruit removal, wax drying, intelligent classification and bagging are analyzed. The design scheme is to reduce the apples’ surface damage, improve the degree of mechanization.
Variable stiffness stability analysis based on time-domain method and experimental verification
Authors: Wang Min , Yang Quankai , Qin Peng , Sun Tiewei , Wang Chen
Published: October 2019

During the turning process, if the feed rate too high, or the feed rate too large, chattering will be occurred. The variable stiffness tip can change the system stiffness during the machine work, so as to increase the limit depth, but the stability of time-varying systems is difficult to predict. This article will be explained in as follows: Firstly, in this paper, the turning stiffness is studied, and the turning dynamics model is established. Secondly, it predicts the limit depth of cut by changing the time domain model parameters, and using the variable stiffness method to optimize the ultimate depth of cut. Finally, verify the correctness of the limit depth of cut through experiments.
Influence of installation error on roundness error measurement
Authors: Chen Xuelei , Dai Yifan , Hu Hao , Tie Guipeng , Guan Chaoliang
Published: October 2019

The installation tilt causes the actual measured circular contour to be an elliptical contour [1], and the installation eccentricity causes the sampled points uneven [2], which can both affect the measurement accuracy of the roundness error [3, 4]. The tilt and eccentricity error must be separate from the measured data when measuring the cylindrical workpiece roundness error with a cylindricity measuring instrument to obtain the true contour information of the cylindrical workpiece itself. In this paper, the mathematical models of the workpiece installation tilt and eccentricity are established based on the least square roundness error evaluation algorithm. The influence of the workpiece installation tilt and eccentricity on the roundness error measurement are simulated by MATLAB, and an actual measurement is analysed. The results show that after leveling and centering the workpiece, the influence of the tilt and eccentricity error of the workpiece installation on roundness error measurement can be neglected when the Taylor565H type cylindricity measuring instrument is used for micron order roundness error measurement.
Investigation of camshaft grinder’s electric spindle mounted with electromagnetic bearings
Authors: Feng Jianjun , Wu Zhi , Xu Zhiqiang
Published: October 2019

In the process of high-speed grinding, the deflection of the spindle axis of the grinder has a severe impact on the surface quality of the workpiece. To solve the problem of bending deformation of the motorized spindle, aiming at the traditional cam grinder, the structure of grinding spindle is designed with active control of electromagnetic bearing. Due to the influence of centrifugal inertia force on deformation, the equation of deformation of the rod is deduced, and the relationship between minimum distortion of the motorized spindle and the displacement of grinding wheel end and the electromagnetic loading force is obtained. The finite element method is used to analyze the relationship between the minimum bending deformation of motor The most suitable electromagnetic force to restrain the spindle is received at different rotational speeds due to the deflection of the motorized axis. The results show that the deviation of grinder spindle is effectively suppressed by applying appropriate electromagnetic force. Reduce the vertical displacement of the spindle grinding wheel end. The results obtained have specific guiding significance for the design of electromagnetic bearing motorized spindle and the improvement of grinding accuracy.
Experimental study on vibration of air cooling fan bridges
Authors: Guo Tieneng , Bai Chunsheng , Wang Li , Cao Jinxuan , Yan Zhijie , Yang Tao
Published: October 2019

ACC (air cooled condenser) is widely used in coal-fired power plants. It has the advantages of water saving and energy saving, and the system is simple. The fan bridge is an important part of the ACC. At present, the vibration problem of the fan bridge is very much, and the experimental data of the bridge vibration is single, and the fundamental vibration source problem is not revealed. Therefore, it is important to study the vibration causes of the wind turbine bridge. This paper analyzes the possible causes of vibration of the fan bridge. Through the combination of field test and theoretical analysis, the main causes of bridge vibration are analyzed. Research shows that air disturbance is the main cause of bridge vibration. The research results provide basis for bridge design.
Motion Attitude Analysis Method of Bullets Based on Field Shadow Image
Authors: Zhou Yijie , Gao Hongju , Sun Zhonghui , Qiao Zhiwang , Di Changan
Published: October 2019

Aimed at obvious interference noise of shadow images of bullet shot in outside field, and larger extraction error of bullet attitude features of shadow images and other problems, intersection point location method based on axis line and edge is adopted to extract features of bullet tip, and the method based on ellipse fitting is adopted to extract features of bullet tail in the Paper, and then extracted feature information is used to calculate motion attitude of bullets. The method can be applied to shadow image analysis of bullets under field environment well with accurate feature extraction, good consistency and high analysis precision and other features.