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15 August 2019, Volume 40 Issue 8 Previous Issue    Next Issue
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Information & Control
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Information & Control

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Minimax Congestion Control for a Class of TCP Network Systems JING Yuan-wei， LI Zan-hua， LIU Ting 2019, 40 (8):  1065-1069.  DOI: 10.12068/j.issn.1005-3026.2019.08.001 Abstract ( 605 )   HTML   PDF (499KB) ( 577 )   The congestion control for TCP network systems with UDP(user datagram protocol)flows is studied. Firstly， a nonlinear TCP network model with a strict-feedback structure is established. Afterwards， a novel congestion control algorithm is proposed by using backstepping approach and minimax scheme， and a sufficient condition is provided. Furthermore， a state-feedback congestion controller is constructed by considering the maximum UDP flows to make the TCP networks stable. Finally， four different cases are simulated. Especially in the presence of maximum interference， the four different control methods are compared. The simulation results show the feasibility and superiority of the proposed method. References | Related Articles | Metrics

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A Sunshine-Based Trajectory Simplification Algorithm RU Jing-yu， JIA Zi-xi， WU Cheng-dong 2019, 40 (8):  1070-1075.  DOI: 10.12068/j.issn.1005-3026.2019.08.002 Abstract ( 565 )   HTML   PDF (2148KB) ( 659 )   Sunshine has played a critical role in trajectory analysis. It is of great significance to design an algorithm that could not only estimate the sunshine information of the trajectory effectively， but also remove the redundant points and keep the necessary sunshine-based information. This paper proposes a sunshine based trajectory simplification algorithm， which considers the urban trajectory character， to solve the challenges of trajectory analyzing in various sunshine related scenarios. On the one hand， an orientation model is established to abstract the relationship between trajectory and sunlight. On the other hand， a sunshine related trajectory simplification model is proposed， and the genetic algorithm is applied to find the points that need to be reserved. Finally， the real-world data of Minneapolis， US， is used for experiment. The results demonstrate that the proposed algorithm can effectively reduce the number of turning points in the trajectories under the control of bound Tmax. References | Related Articles | Metrics

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Reflective Fiber Optic SPR Sensor for Nitrate Concentration Measurement LUY Jiang-tao， WANG Xiao-jun， E Si-yu， ZHANG Ya-nan 2019, 40 (8):  1075-1079.  DOI: 10.12068/j.issn.1005-3026.2019.08.003 Abstract ( 603 )   HTML   PDF (781KB) ( 650 )   A reflective fiber optical sensor based on surface plasmon resonance(SPR)is proposed for measuring nitrate concentration. The reflective structure sensor is coated with gold film to excite SPR. A copper nanoparticles/carbon nanotube(Cu-NPs/CNT)film is prepared as a sensitive film for nitrate concentration measurement. When the concentration of nitrate changes， the concentration of ammonia catalyzed by copper adsorbed on the CNT also changes， thus causing the refractive index of the CNT to change. The change of the refractive index leads to the shift of SPR resonance dip， so that nitrate concentration can be measured. The experimental results show that the sensor had an average sensitivity of 14.14nm/lg［c/(mol·L-1)］ in the low concentration range. This sensor is easy to package and can be used for long-distance measurement， and will have potential applications in biochemical parametric measurement. References | Related Articles | Metrics

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Design and Implement of TEE-Based Trusted Storage System ZHANG Qiang， QIAO Jian-zhong 2019, 40 (8):  1080-1086.  DOI: 10.12068/j.issn.1005-3026.2019.08.004 Abstract ( 683 )   HTML   PDF (820KB) ( 861 )   Based on the analysis of currently mainstream trusted storage system(TSS)， we design and implement a trusted execution environment(TEE)-based TSS， which conforms to Global Platform(GP)standard. Our TSS provides not only authorized encryption，the integrity and consistency of data， but also many security storage operation properties such as atomicity operations of persistent object. In order to improve the read/write performance of big data， a new method is proposed for dynamically allocating continuous memory in REE’s kernel memory space and mapping the address to the TEE through communication pipe. This method can reduce switching times， allocating memory times and copy memory overloads between two worlds. The experiments show that our system has an 8% to 10% performance improvement compared with related trusted storage systems. References | Related Articles | Metrics

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Sparse Sampling and Reconstruction Algorithm of Electrocardiogram Signal in Compressed Sensing QI Lin， XING Jia-zhu， CHEN Jun-xin， ZHANG Liang-yu 2019, 40 (8):  1087-1093.  DOI: 10.12068/j.issn.1005-3026.2019.08.005 Abstract ( 927 )   HTML   PDF (450KB) ( 958 )   Real-time electrocardiogram(ECG) monitoring will result in large data volume， which brings about severe pressure on the transmission and storage of the system. In order to reduce the computational complexity of data acquisition and the data volume in transmission， compressed sensing was used for the ECG signal. Taking time and error of signal reconstruction as critical indicators， the performance of different reconstruction algorithms and wavelet basis are comprehensively studied. The results demonstrate that when the compression ratio is within 30%， the percentage mean-square difference of the basis tracking algorithm is less than 4%， and the reconstruction takes the shortest time. When the compression ratio is within 70%， the error of subspace tracking algorithm is less than 10%， and the reconstruction time is always the lowest. However， the optimal wavelet basis is generally related to the specific compression ratio. References | Related Articles | Metrics

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Graph Theory Based Study on Multi-weighted Structural Brain Network of Schizotypal Personality Disorder QI Shou-liang， ZHANG Bo， LI Meng， WU Jian-lin 2019, 40 (8):  1093-1098.  DOI: 10.12068/j.issn.1005-3026.2019.08.006 Abstract ( 620 )   HTML   PDF (928KB) ( 720 )   With graph theory methods， this study identified the differences in nodal and global parameters between schizotypal personality disorder(SPD) and healthy control(HC). Firstly， the whole brain was divided into 246 regions of interest(ROIs)based on the human Brainnetome Atlas， then the fiber bundles were reconstructed based on DWI images， and the structural networks were constructed by statistics under the four weighting methods: fiber number， fiber density， fiber length and optimized fiber density. Secondly， nodal and global parameters were calculated， and brain ROIs with significant differences were determined by two-sample t-tests between groups. The results show that there is no difference in global parameters， but in nodal scale， SPD is significantly different in six ROIs. The distribution of ROIs is asymmetric in the left and right hemisphere. The functions of ROIs are highly related to cognition， emotion and perception. These findings would help the diagnosis and treatment of SPD. References | Related Articles | Metrics

Materials & Metallurgy

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Influence of Cold Rolling Process on Formability of a Ferritic Stainless Steel LIU Hou-long， LIU Ling-ling， LI Xing， CHEN Li-qing 2019, 40 (8):  1099-1104.  DOI: 10.12068/j.issn.1005-3026.2019.08.007 Abstract ( 697 )   HTML   PDF (1129KB) ( 589 )   In order to study the effect of cold rolling process on the formability of 19Cr2Mo1W ferritic stainless steel， the micro structure and texture evolution of this steel during cold-rolling and annealing processes were investigated by X-ray diffraction(XRD)， electron back-scatter diffraction(EBSD)，roughness and plastic strain ratio analytical methods. The results indicated that the amount of α and γ fiber textures in cold-rolled sheet increased with the increase of cold rolling reduction， and the stable orientation of α and γ fiber textures during cold rolling was223〈110〉and 111〈011〉component， respectively. In addition， the strength of the γ recrystallization texture became higher， when the amount of223〈110〉component increased. After annealing at 1050℃ for 1 min， the recrystallized ferritic grains in the sheet distributed uniformly with a fine grain size， the surface roughness was small and the strength of the γ fiber texture was relatively high， i.e.，the formability of the cold-rolled steel sheet was the best. References | Related Articles | Metrics

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Dimensional Analysis of Average Bubble Diameter in Desulfurization of Hot Metal WANG Kun， LIU Yan， YANG Yong-kun， ZHANG Ting-an 2019, 40 (8):  1105-1109.  DOI: 10.12068/j.issn.1005-3026.2019.08.008 Abstract ( 494 )   HTML   PDF (499KB) ( 505 )   In order to decrease magnesium vapor bubble diameter in desulphurization of hot metal and to improve desulphurization efficiency， the effects of the equipment parameters and operating conditions on average bubble diameter were studied by a water model based experiment. The bubble dispersions under different experimental conditions were collected by a high-speed camera. The image analysis software was used to obtain the average bubble diameter under different experimental conditions and the major factors were analyzed by a water model based experiment. A relationship between the average bubble diameter and the major influencing factors was established， according to the homogeneous principle and Buckingham’s theorem. The relationship between the average bubble diameter and the experimental conditions can be obtained by fitting the related parameters with experimental data. References | Related Articles | Metrics

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Thermodynamic Analysis of Producing Hydrogen by Sorption Enhanced Steam Reforming Process of Raw Coke Oven Gas XIE Hua-qing， ZHAO Xiang-nan， YU Qing-bo， QIN Qin 2019, 40 (8):  1110-1114.  DOI: 10.12068/j.issn.1005-3026.2019.08.009 Abstract ( 685 )   HTML   PDF (752KB) ( 618 )   Thermodynamic analysis of producing hydrogen by the steam reforming process of raw coke oven gas(RCOG)was carried out using Aspen Plus software．It was found that the normal pressure was the best pressure for hydrogen-producing reaction by the steam reforming of RCOG without CO2 sorbent(i.e.， ordinary reforming)and with CO2 sorbent of CaO(i.e.， sorption-enhanced reforming). With increasing temperature and the ratio of steam to carbon(n○S/n○C)， the amount and concentration of H2 increased， while they changed slightly after n○S/n○C was over 3. The addition of CaO enhanced the reforming reaction process， resulting in the decrease of the best reaction temperature and the increase of the amount and concentration of H2. Compared with those by ordinary reforming， the best temperature for the reaction by sorption-enhanced reforming with n○CaO/n○C=1 dropped from 650℃ to 450℃， the amount of H2 increased from 186 mol to 212mol per 100mol RCOG， the volume fraction of H2 increased from 74% to 97%， and the energy consumption of producing hydrogen decreased from 2.26kW·h/m3 to 2.00kW·h/m3， when n○S/n○C=3. References | Related Articles | Metrics

Mechanical Engineering

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Analysis of Dynamic Characteristics of the Rotating Shrouded Blade Considering Elastic Support MA Hui， CUI Can， ZENG Jin， WEN Bang-chun 2019, 40 (8):  1115-1121.  DOI: 10.12068/j.issn.1005-3026.2019.08.010 Abstract ( 490 )   HTML   PDF (1136KB) ( 622 )   An analytical model of the shrouded blade considering elastic support is established， in which the influence of the blade’s rotational effect， setting angle， twist angle and variable cross-section are taken into consideration. ANSYS software is used to establish a corresponding finite element model to verify the effectiveness of the established analytical model. The influence of the support stiffness and shoulder position on the dynamic characteristics of the blade is analyzed through the established analytical model and finite element model. The results indicate that as the support stiffness increases， the natural frequency of the shrouded blade increases. However， after the support stiffness increases to a certain extent， the increase of the support stiffness will no longer cause the increase of the natural frequency. In addition， as the distance from the shoulder position to the blade tip increases， the first-order and third-order natural frequency of the shrouded blade tends to increase. In contrast， the second-order natural frequency will decrease. In addition， analytical methods can significantly improve the computational efficiency. References | Related Articles | Metrics

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Experimental Study on Influence of Vibration Parameters on Screening Efficiency CHEN Ya-zhe， YAO Hong-liang， LIU Gang 2019, 40 (8):  1122-1126.  DOI: 10.12068/j.issn.1005-3026.2019.08.011 Abstract ( 666 )   HTML   PDF (628KB) ( 978 )   The effects of vibration parameters on particle screening efficiency were studied by using dried silicon powder， molybdenum powder and zinc powder as typical materials. Firstly， the effects of vibration frequency， angle of eccentric block， thickness of material layer and different material properties on the screening efficiency of common rotary vibrating screen were investigated， and the optimal vibration parameters of typical materials under the action of common rotary vibrating screen were obtained. Then， the ultrasonic vibration experiment was carried out. The experiment shows that the ultrasonic vibration could effectively disperse the particle aggregates of the fine powder materials， solve the problem of the screen hole blockage， thus improving the screening efficiency significantly. According to the experimental results， the optimum combination parameters of silicon powder particles under the combined action of ordinary vibration and ultrasonic vibration can be obtained. References | Related Articles | Metrics

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Effect of Nano MoS2Concentrations on Nano Minimum Quantity Lubrication in CFRPs Grinding ZHAO Xu-feng， YU Tian-biao， LI Chang-he， WANG Wan-shan 2019, 40 (8):  1127-1131.  DOI: 10.12068/j.issn.1005-3026.2019.08.012 Abstract ( 590 )   HTML   PDF (2385KB) ( 554 )   To investigate the effect of nano MoS2 concentration on minimum quantity lubrication(MQL)in grinding carbon fiber reinforced plastics(CFRPs)， the grinding experiments of CFRPs were carried out with lubricating oils of various concentrations(0%， 3%， 6%， 9%， and 12%)of nano MoS2 in palm oil. The surface roughness and morphology of the CFRPs were studied by optical microscopy. The grinding forces were measured by dynamometer， and the grinding force ratio was calculated and analyzed. Also， the CFRPs grinding mechanism with MQL of various nano MoS2 concentrations was explained. The results show that when the mass fraction of nano MoS2 reaches 9%， the grinding force ratio reaches the lowest value of 0.0632， and the quality of surface roughness with R○aof 1.86μm and surface morphology of CFRPs are both better than those with other concentrations. References | Related Articles | Metrics

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Influence of Nonlinearity Factors of Rolling Bearings on Vibration Characteristics of Rotor System LUO Zhong， ZHOU Yi-fu， BIAN Zi-fang， WANG Fei 2019, 40 (8):  1131-1138.  DOI: 10.12068/j.issn.1005-3026.2019.08.013 Abstract ( 582 )   HTML   PDF (958KB) ( 714 )   Aiming at the hysteresis jump of a rotor system supported by rolling bearings during operation， by using the HB-AFT method embedded in the homotopy arc extension， the interval of the hysteresis jump of the rotor system supported by rolling bearings can be quickly calculated. The Floquent theory is used to determine the stability， and the effects of bearing equivalent stiffness， bearing clearance and linear damping coefficient on the hysteresis jump of the rotor system are analyzed. The results show that the variation of bearing clearance and bearing equivalent stiffness within a certain range will affect the hysteresis jump range of the rotor system， and the damping coefficient only affects the system’s vibration amplitude near the critical speed of the rotor system. The results of the study provide a theoretical reference for setting the bearing-rotor system parameters. References | Related Articles | Metrics

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Influence of Thermal Deformation of Rolling Linear Guide on Contact Stiffness ZHANG Yao-man， ZHENG Wei 2019, 40 (8):  1139-1143.  DOI: 10.12068/j.issn.1005-3026.2019.08.014 Abstract ( 641 )   HTML   PDF (861KB) ( 568 )   Taking an HSR15A rolling linear guide as a research object， its elastic deformation under the conditions of pre-loading and thermal deformation is analyzed on the basis of Hertz contact theory. The geometric relationship of the deformation of the rolling linear guide’s joint surfaces is established， and the theoretical model for the influence of thermal deformation of joint surfaces on contact stiffness is derived. The temperature distribution of the rolling linear guide under different vertical loads and the influence of thermal deformation on the guides’s stiffness are analyzed by using the finite element software. The results show that with the increase of vertical load， the stiffness of the upper raceway increases gradually， while the stiffness of the lower raceway decreases and the equivalent stiffness decreases also; the stiffness of the rolling linear guide can be reduced by thermal deformation， and the influence of the thermal deformation on the stiffness becomes more and more significant with the increase of vertical load. References | Related Articles | Metrics

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Automatic Compensation of Digital Holographic Microscopic Phase Distortion Based on the Reference Objective MA Shu-jun， ZHOU Peng-fei， LIU Wei-hua 2019, 40 (8):  1144-1149.  DOI: 10.12068/j.issn.1005-3026.2019.08.015 Abstract ( 571 )   HTML   PDF (1976KB) ( 579 )   The method of combining reference objective and numerical fitting is established to solve the phase distortion of off-axis digital holography. Because of the optical curvature difference caused by the objective， the pre-amplified digital holographic microscopy system often produces additional phase factors. By introducing the same reference objective in the reference beam path， the phase distortion due to curvature problems is initially eliminated. With the addition of the reference objective， phase distortion mainly comes from three aspects: the numerical simulation of plane reference light is used in diffraction calculation， and a phase distortion is generated with the off-axis structure having a spatial angle; the actually recorded hologram causes a secondary phase distortion because the object wave passes through the pre-amplified objective; the other optical components in the optical path form aberrations， failing to get the correct 3D shape of the microstructure. The entire phase surface is fitted by a polynomial， and the difference between the phase surface and the fitted surface is used to extract the true phase distribution of the sample. With only one hologram， multiple phase distortions are automatically compensated by a polynomial fit. The USAF resolution plate being used as the microstructure pattern for measurement，the accuracy and effectiveness of the method are verified. References | Related Articles | Metrics

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Topological Optimization Design of Blade-Type Grinding Head Structure for Integral Blade Disk Polishing Machine HUANG Zhi， WU Xiang， WANG Hong-yan， ZHOU Tao 2019, 40 (8):  1149-1153.  DOI: 10.12068/j.issn.1005-3026.2019.08.016 Abstract ( 582 )   HTML   PDF (2555KB) ( 671 )   Aiming at the lightweight design target of the head structure of grinding and polishing machine for the blade surface grinding of aeroengine’s overall blade disk， the variable density method for topological optimization design was applied to the grinding head support plate. Based on the static and dynamic analysis of the grinding head structure， the theory of topological optimization of variable density method was studied. Based on the topologically optimized material distribution results， the lightweight structure and size optimization of the grinding head structure were carried out， and the final design parameters of the grinding head structure were obtained. The results showed that the mass of the optimized grinding head structure is reduced by 8.74%， and the dynamic and static mechanical properties of the structure are advanced， that is， the lightweight design of the grinding head structure is well achieved. References | Related Articles | Metrics

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Tooth Surface Design and Sliding Characteristics Analysis of Compound Motion Curve Face Gear Pair LIN Chao， HE Chun-jiang， HU Ya-nan， CAI Zhi-qin 2019, 40 (8):  1154-1159.  DOI: 10.12068/j.issn.1005-3026.2019.08.017 Abstract ( 592 )   HTML   PDF (726KB) ( 684 )   According to the gear meshing theorem， the ordinal design of the pitch curve and tooth surface of the gear pair is presented to realize the predicted transmission function for different application. Based on the complex motion and applications of curve face gear， the transmission ratio and axial movement speed are proposed by space coordinate transformation， also the slip velocity equation on the tooth surface curve face gear is established. The sliding characteristics on the tooth surface with different parameters are given. The results show that the size and direction of sliding velocity vary with the tooth height， and the sliding characteristics of the 5 teeth are different during the half cycle. References | Related Articles | Metrics

Resources & Civil Engineering

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Fluidization Characteristics of U-Typed Reduction Chamber with Pressure Fluctuation Method TANG Zhi-dong， HAN Yue-xin， GAO Peng， LI Er-lei 2019, 40 (8):  1160-1165.  DOI: 10.12068/j.issn.1005-3026.2019.08.018 Abstract ( 598 )   HTML   PDF (714KB) ( 510 )   The U-typed reduction chamber is the core reaction device of the iron suspension roaster. In order to study the fluidization characteristics， a cold experiment system of U-typed reduction chamber was established. Based on the experimental data collected by pressure fluctuation method， the following conclusions were drawn. Aeration velocity and particle size were the main factors affecting the initial fluidization velocity， while the initial bed height had little effect. With the increasing of initial bed height and aeration velocity， the pressure fluctuation in fluidization chamber became lower， but opposite result was obtained for particle size. Besides， power spectrum analysis revealed that the formation， coalescence and fragmentation of bubbles were the fundamental reasons for pressure fluctuation. The results would provide theoretical support for the design and optimization of the operating parameters during suspension magnetization roasting experiments. References | Related Articles | Metrics

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Influence of PEG/WCl6 Ratio on the Morphology and Gas Sensing Properties of WO3 Thin Films ZHOU Peng-fei， ZHAO Si-kai， WANG Wei， SHEN Yan-bai 2019, 40 (8):  1166-1171.  DOI: 10.12068/j.issn.1005-3026.2019.08.019 Abstract ( 675 )   HTML   PDF (1359KB) ( 679 )   WO3 thin films were synthesized by a non-hydrolytic sol-gel(NHSG)method in the presence of WCl6， C2H5OH and C3H7NO as the precursor as well as the PEG-1000 as the pore former. The influence of PEG/WCl6 ratio on the morphology and gas sensing properties of WO3 thin films were investigated.It is shown that WO3 thin films with uniform morphology， high porosity and large specific surface area were obtained at the PEG/WCl6 ratio of 0.5. The obtained thin films have a single monoclinic crystal structure and consist of WO3 crystalline nanoparticles with the diameters of 20~60nm. The gas sensing measurements indicate that WO3 thin films show n-type semiconductor characteristics and demonstrate excellent gas sensing properties at the optimal operation temperature of 100℃. The film formation mechanism of WO3 thin films indicates that PEG-1000 may induce the inorganic material to form a three-dimensional porous film structure with high porosity and large specific surface area. The obtained WO3 porous films are potential sensing materials for the detection of NO2. References | Related Articles | Metrics

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Mechanism of Water Flow Migration Evolution in Multi-layer Soil Slope During Rainfall Infiltration WANG Shu-hong， HE Jian， LIU Huan 2019, 40 (8):  1172-1178.  DOI: 10.12068/j.issn.1005-3026.2019.08.020 Abstract ( 628 )   HTML   PDF (1626KB) ( 633 )   In order to study the law of water flow migration in multi-layer soil slope， the homogeneous soil slope model and the multi-layer soil slope model were established. The temporal and spatial characteristics and influencing factors of water flow migration were explored， with the development of saturated-zone taken into account， based on the governing equation of moisture content and matrix suction in multi-layer soil slope derived from the VG model. The relationship between water flow migration and effective stress was also studied. It is found that the difference in the matrix suction in the horizontal direction decides the change of water flow migration mode and the rate of change of matrix suction along the horizontal direction determines the rate increment of water flow horizontal direction. The formation of the saturated-zone is a necessary condition for forming the vertical water flow. After the rainfall stops， the down-slope water flow is rapidly generated only in the shallow layer of 0~1.3m， with the forming of down-slope water flow in deep area lagging behind. The horizontal water flow at the interface of two layers of soil with large differences in permeability changes sharply， and the forming of up-slope water flow is always accompanied with the decrease of effective stress. References | Related Articles | Metrics

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Numerical Analysis on Thermo-Hydro-Mechanical Coupling of Surrounding Rocks in Cold Region Tunnels YANG Tian-jiao， WANG Shu-hong， ZHANG Ze， GAO Yu 2019, 40 (8):  1178-1184.  DOI: 10.12068/j.issn.1005-3026.2019.08.021 Abstract ( 681 )   HTML   PDF (1919KB) ( 867 )   Based on the theory of “three regions”， a combined differential equation is established to solve the problems of hydro-thermal coupling in cold regions considering water transfer and water ice phase transition. The numerical simulation of temperature field coupled with water field was carried out by COMSOL multi-physics software， and the numerical simulation results were compared with the results of soil column freezing experiment to verify the effectiveness of the hydrothermal coupled numerical simulation model. By considering the theory of frost heave， the stress field governing equation of the tunnel in the cold regions is deduced， and the thermo-hydro-mechanical coupled model of the tunnel in the cold regions is established by using the relationship between pore ice and frost heave rate. Finally， the temperature field， humidity field and stress field were simulated by taking the Musui tunnel between Mudanjiang and Suifenhe as a case study. The results show that the change in external temperature has a great impact on the tunnel after excavation. The thickness of the freezing ring of the tunnel hole gradually increased with time and reached a maximum depth of about 2meters in January. References | Related Articles | Metrics

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Disease Mechanism and Theoretical Quantification Method of Tunnel Structure LIU Yu， WANG Peng-yu， WANG Shu-hong， LING Shuang 2019, 40 (8):  1185-1190.  DOI: 10.12068/j.issn.1005-3026.2019.08.022 Abstract ( 726 )   HTML   PDF (502KB) ( 864 )   The distribution characteristics and laws of existing structural defects of tunnel lining are summarized based on the regular inspection data of expressway tunnels in Liaoning Province. On the basis of in-depth study of the main structural diseases of the tunnel， the extenics theory is used to extract several indicators that can accurately reveal the health status of the structure， to quantify and classify the health status， and to establish the corresponding matter-element model， so as to determine the weight of each indicator and the grade of tunnel structure disease. A health evaluation system for tunnel lining structure is constructed by combining qualitative evaluation and quantitative research， which is convenient for managers to make reasonable decisions. At the same time， based on the actual test data of tunnel engineering， the calculation and analysis of the extension model are carried out to verify the engineering applicability of the model. References | Related Articles | Metrics

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Experimental Study on Lower Flammability Limits of CO2/N2 Diluted Syngas SHANG Rong-xue， WAN Song， YANG Hong-xia， LI Gang 2019, 40 (8):  1191-1196.  DOI: 10.12068/j.issn.1005-3026.2019.08.023 Abstract ( 630 )   HTML   PDF (555KB) ( 568 )   The lower flammability limits of syngas/air mixtures with CO2 and N2 inert dilution were experimentally studied under atmospheric conditions via a self-developed closed cylindrical stainless steel vessel. The experimental data were used to validate the performance of the Le Chatelier’s Rule. The experimental results showed that， the lower flammability limit of fuels mixtures decreases with the increase of H2 fraction. A small amount of H2 in the fuels presents the significant effect on the lower flammability limit of mixtures due to the variation of the controlled mechanism of the reaction. The lower flammability limits of mixtures almost linearly increases with an increase in inert dilution ratio. CO2 has a stronger inert effect than N2 due to CO2’s stronger thermal and chemical kinetic effect in reducing the flame temperature and radical concentrations. The prediction by Le Chatelier’s Rule has great discrepancy against the experimental results when H2 fraction is small or with the high presence of inert species in the mixture. Moreover， the different inter effect between CO2 and N2 on the lower flammability limit cannot be calculated using Le Chatelier’s Rule. References | Related Articles | Metrics

Management Science

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Impact of Buyers’ Market Power on Innovation Incentives of Product Quality in Downstream Enterprises GUO Xiao-ling， LI Kai， NONG Bei 2019, 40 (8):  1197-1204.  DOI: 10.12068/j.issn.1005-3026.2019.08.024 Abstract ( 512 )   HTML   PDF (465KB) ( 570 )   A vertical product quality differentiation model consisting of monopolistic manufacturers and downstream oligarchic competitors was constructed. Based on this model， the changes in quality-innovating incentives and market equilibrium results were investigated before and after the downstream large-scale enterprises with high-quality products had market power. Research showed that when downstream enterprises at different quality levels all have no market power， the quality promotion of any party will stimulate the innovation enthusiasm of its competitors. When a downstream large-scale enterprise has market power and negotiates with an upstream manufacturer， the wholesale prices and the retail prices of the two downstream enterprises will decline with the increase of market power. At the same time， the wholesale prices， retail prices and market sales of the two downstream companies all depend on buyers’ market power while the sales and profitability of small-scale enterprises remain unchanged. References | Related Articles | Metrics

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Effects of Customer Resources on Customer Value from the Perspective of Value Co-creation XIAO Meng， MA Qin-hai 2019, 40 (8):  1205-1211.  DOI: 10.12068/j.issn.1005-3026.2019.08.025 Abstract ( 566 )   HTML   PDF (429KB) ( 668 )   Based on the theory of social identity and organizational support， the empirical research method was used， and the mechanism of customer resources affecting customer value through customer-company identification and perceived organizational support was analyzed. The results showed that:customers’ human resources and relationship resources have a significant impact on customers’ utilitarian value and hedonic value; customers’ human resources and relationship resources have a significant impact on customer-company identification and perceived organizational support; customer-company identification has a significant positive impact on customers’ utilitarian value and hedonic value;perceived organizational support has a significant positive impact on customers’ utilitarian value;customer-company identification and perceived organizational support have mediating effect on the relationship between customers’ human resources and customer value;the relationship between customer-company identification and perceived organizational support is non-recursive. References | Related Articles | Metrics

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Prediction of Carbon Emission and Selection of Optimal Scenario in Liaoning Province HOU Hui， YIN Yun， BU Man-man， HE Jie 2019, 40 (8):  1211-1216.  DOI: 10.12068/j.issn.1005-3026.2019.08.026 Abstract ( 785 )   HTML   PDF (428KB) ( 818 )   Based on the economic development growth rate，energy-saving and emission-reduction constraints， and LMDI decomposition model of the factors that influence carbon emission， the different models of economic/social development variables and energy-saving/emission-reduction variables were combined into six scenarios. The extended SPIRPAT model is used to predict and analyze the carbon emission of Liaoning from 2016 to 2040， and it is concluded that the ‘medium growth and strong emission-reduction’ scenario is the best choice for Liaoning. Under the optimal scenario， the increase of energy consumption in Liaoning in 2020 over 2015 will be much lower than the constraint standard. The provincial planning target of non-fossil energy sources proportion will be reached in 2020 and the national planning target will be reached in 2030. The drop of carbon emission will reach its peak in 2023， and the reduction in carbon emission intensity in 2020 and 2030 over 2005 will exceed the national planning target. If the government can change the mode of economic development effectively， adjust the industrial structure， and improve the development and utilization of clean energy， Liaoning would be able to achieve the goal of energy-saving and emission-reduction without the expense of economic development. References | Related Articles | Metrics