原棉异物剔除系统中的数据流程与系统实时性的实现

分析了原棉异物剔除系统中的数据流程,在此基础上,讨论了如何实现系统运作的实时性的问题。设计出原棉异物剔除系统原理样机,并进行了若干原理样机的调试实验。测试了原理样机的运作实时性,实验结果表明:原理样机能实时地运行。

基于矿井的无线传感器网络MAC协议的研究

介质访问控制(MAC)协议是一项构造底层基础网络结构的重要技术,其主要功能是为数据传输建立连接和在各网络节点间合理、高效地分配通信资源。从节能角度分析了当前几种比较典型的MAC协议,提出矿井下的无线网络拓扑结构,给出一种New-MAC协议,主要研究了节能问题、数据碰撞问题和同步问题。仿真实验表明:该协议较好地解决了节点能耗问题、延长了网络的生命周期。

瞬时无功功率理论及其研究现状

首先介绍了瞬时无功功率理论及公式推导,其次用PSCAD仿真验证了瞬时无功功率的可行性,然后分析目前瞬时无功功率理论在各个领域里的应用情况及其改进现状,最后作了总结和展望。

Modeling commuters' route choice behavior under pre-trip information system

Research about the auto commuter＇s pre-trip route choice behavior ignores the combined influence of the real-time information and all respondents＇ historical information in the existing documents.To overcome this shortcoming,an approach to describing the pre-trip route choice behavior with the incorporation of the real-time and historical information is proposed.Two types of real-time information are investigated,which are quantitative information and prescriptive information.By using the bounded rationality theory,the influence of historical information on the real-time information reference process is examined first.Estimation results show that the historical information has a significant influence on the quantitative information reference process,but not on the prescriptive information reference process.Then the route choice behavior is modeled.A comparison is also made among three route choice models,one of which does not incorporate the real-time information reference process,while the others do.Estimation results show that the route choice behavior is better described with the consideration of the reference process of both quantitative and prescriptive information.

Real-time Threshold Routing Algorithm Based on Wireless Sensor Network

[Objective] This study was to design an intelligent greenhouse real-time monitoring system based on the core technology of Internet of Things in order to meet the needs of agricultural informatization and intellectualization. [Method] Based on the application characteristics of Wireless Sensor Network （WSN）, the intelligent greenhouse monitoring system was designed. And for the incompleteness strategy of load balancing in the Low-Energy Adaptive Clustering Hierarchy （LEACH）, a Real- time Threshold Routing Algorithm （RTRA） was proposed. [Result] The performance of network lifetime and network delay of RTRA were tested in MATLAB and found that, within the same testing environment, RTRA can save nodes energy consumption, prolong network lifetime, and had better real-time performance than LEACH. The al- gorithm satisfies the crops＇ requirements on real-time and energy efficiency in the greenhouse system. [Conclusion] For the good performance on real-time, the de- signed intelligent greenhouse real-time monitoring system laid the foundation for the research and development of agricultural informatization and intellectualization.

Technology for Enzymolysis of Jellyfish Brain Protein by Bromelain

[Objective] This study aimed to investigate the optimal technology for en- zymolysis of jeUyfish brain protein by bromefain. [Method] Effects of enzymolysis temperature, the amount of added enzyme, solid/liquid ratio, enzymolysis time and pH on the enzymolysis of total protein were investigated through single factor ex- periments, and some technical parameters were optimized by orthogonal experi- ments. [Result] The results revealed that enzymolysis temperature of 55℃, the amount of added enzyme of 4 000 U/g, solid/liquid ratio of 1：4, the amount of added enzyme time for 5 h and pH 7 were the optimal combination of parameters for the enzymolysis; the average degree of hydrolysis obtained from the verification tests was 36.9%, indicating that the optimized results of the orthogonal experiment were credible. [Conclusion] This study provides the optimized conditions reliable theo- retical foundation and technical support for the exploitation and utilization of jellyfish resources as medicines or functional food in China.

Integrated identification method of rheological model of sandstone in Sanmenxia bauxite

Based on the uniaxial compression creep experiments conducted on bauxite sandstone obtained from Sanmenxia,typical creep experiment curves were obtained.From the characteristics of strain component of creep curves,the creep strain is composed of instantaneous elastic strain,ε（me）,instantaneous plastic strain,ε（mp）,viscoelastic strain,ε（ce）,and viscoplastic strain,ε（cp）.Based on the characteristics of instantaneous plastic strain,a new element of instantaneous plastic rheology was introduced,instantaneous plastic modulus was defined,and the modified Burgers model was established.Then identification of direct screening method in this model was completed.According to the mechanical properties of rheological elements,one- and three-dimensional creep equations in different stress levels were obtained.One-dimensional model parameters were identified by the method of least squares,and in the process of computation,Gauss-Newton iteration method was applied.Finally,by fitting the experimental curves,the correctness of direct method model was verified,then the examination of posterior exclusive method of the model was accomplished.The results showed that in the improved Burgers models,the rheological characteristics of sandstone are embodied properly,microscopic analysis of creep curves is also achieved,and the correctness of comprehensive identification method of rheological model is verified.

EFFECT OF TIME AND ENVIRONMENT ON THE DIMENSION PRECISION AND MASS OF LOM PROTOTYPES

The effect of time and environment on the dimension precision and mass of LOM prototypes was experimentally investigated.It is to identify the stability of the dimension of LOM prototypes after forming.The results show that the dimension and the mass tendency to grow,which is mainly caused by elastic recovery and moisture absorption and is characterized principally by the growth of Z dimension.Self restraint can be a significant factor to influence Z growth of LOM prototypes.

Changes of the Transcriptional Levels of Molecules Associated with Endogenous Antigen Processing and Presentation in Porcine Skin-derived Dendritic Cells Infected with PCV2 in vivo

[Objective] This study aimed to investigate the changes of the transcriptional levels of molecules associated with endogenous antigen processing and presenta- tion in porcine skin-derived dendritic cells infected with PCV2 in vivo. [Method] Healthy 40-day-old Landrace piglets were infected with porcine circovirus type 2 （PCV2） and euthanized on the 34, 7rd, 14th, 21st and 35th d post inoculation （DPI）. The porcine skin-derived dendritic cells （DCs） were collected to analyze the transcrip- tional levels of molecules （LMP7, UBP, MHC-I, calreticulin） associated with endogenous antigen processing and presentation by using real-time fluorescent quantitative PCR （real-time FQ-PCR）. [Result] The results showed that the level of LMP7 mR- NAs was reduced significantly on the 3DPI （P〈0.05）; the level of UBP mRNAs was consistently up-regulated, which increased significantly on the 21DPI and 35DPI （P〈 0.05）; the level of MHC-I mRNAs was significantly down-regulated on the 7DPI （P〈 0.05）; the level of calreticulin mRNAs was up-regulated slightly without significant dif- ference. [Conclusion] PCV2 can inhibit the endogenous antigen processing and presentation ability of porcine skin-derived DCs at early stages of infection.

Long-release-interval-first real-time scheduling algorithm and its schedulability test

To fulfill the requirements for hybrid real-time system scheduling, a long-release-interval-first （LRIF） real-time scheduling algorithm is proposed. The algorithm adopts both the fixed priority and the dynamic priority to assign priorities for tasks. By assigning higher priorities to the aperiodic soft real-time jobs with longer release intervals, it guarantees the executions for periodic hard real-time tasks and further probabilistically guarantees the executions for aperiodic soft real-time tasks. The schedulability test approach for the LRIF algorithm is presented. The implementation issues of the LRIF algorithm are also discussed. Simulation result shows that LRIF obtains better schedulable performance than the maximum urgency first （MUF） algorithm, the earliest deadline first （EDF） algorithm and EDF for hybrid tasks. LRIF has great capability to schedule both periodic hard real-time and aperiodic soft real-time tasks.

Analysis on Tissue-specific Expression of Dp XTH1 and Dp XTH2 Genes in Dahlia

[Objective] This study aimed to investigate the functions and related mechanisms of xyloglucan Endotransglycosylase/hydrolases （XTHs） during the growth and development of dahlia. [Method] Using /3-actin as the reference gene, the rela- tive transcription levels of DpXTH1 and DpXTH2 genes in roots, stems, leaves and petals of dahlia were analyzed by real-time RT-PCR. [Result] The DpXTH1 and DpXTH2 were not expressed in the roots, but expressed abundantly in the petals of dahlia. There were little expressions in the stems and leaves of dahlia. [Conclusion] The DpXTH1 and DpXTH2 were petal-specific genes and closely related to the growth and development of petals in dahlia.

Design and implementation of multi-hop video transmission experiment system in VANET

Abts ract A wireless mutl i-hop videot ransmission experiment system is designed and implemented for vehiculra ad-hoc networks VANET and the rt ansm ission control protocol and routing protocol are proposed. This system in tegrates the embedded Linux system witha n ARM kernel and oc ns ists of a S3C6410 main control module a wirel ss local arean etwork WLAN card a LCD screne and so on.In the scenario of a wireless multi-hop video transmission both the H.264 and JPEG are used and their performances such as the compression rate delay and frame loss rate are analyzed in theory andc ompared in the experiment.The system is tested in the real indoor and outdoor environment.The results show that the scheme of the multi-hop video transmission experiment system can be applicable for VANET and multiple scenes and the transmission control protocol and routing protocol proposed can achieve real-time transmission and meet multi-hop requirements.

Transition metal catalysis in lithium‐ion batteries studied by operando magnetometry

Owing to the potential ability of metal nanoparticles to enhance the performance of energy storage devices,their catalytic performance has been studied by many researchers.However,a limited number of suitable characterization techniques does not allow fully elucidating their catalytic mechanism.Herein,high‐accuracy operando magnetometry is employed to investigate the catalytic properties of a cobalt oxide electrode for lithium‐ion batteries fabricated by magnetron sputtering.Using this technique,the magnetic responses generated by the Co‐catalyzed reversible formation and decomposition of a polymer/gel‐like film are successfully detected.A series of CoO/Co films are prepared by magnetron sputtering in different environments at various sputtering times to study the influence of Co content and film thickness on their catalytic properties.It is clearly demonstrated that increasing the Co content enhances the magnetic signal associated with the catalysis process.Furthermore,decreasing the electrode thickness increases the area affected by the catalytic reactions,which in turn enhances the corresponding magnetic responses.The obtained results experimentally confirm the catalytic activity of Co metal nanoparticles and provide a scientific guidance for designing advanced energy storage devices.This work also shows that operando magnetometry is a versatile technique for studying the catalytic effects of transition metals.

Application of Real-time Ultrasound Elastography in Diagnosing Benign and Malignant Thyroid Solid Nodules

Objective Real-time ultrasound elastography(US-E) is a helpful tool in diagnosing thyroid nodules.This study aims to evaluate thyroid solid nodules,to establish the accuracy of US-E in providing information on the nature of these nodules,and to assess the clinical value of elasticity scores(ES) and strain ratio(SR) in differentiating thyroid solid nodules and to explore its distribution characteristics using pathological analysis as reference. Methods Traditional ultrasonography and US-E were performed on 131 thyroid solid nodules(99 benign ones and 32 malignant ones) in 120 patients(78 females and 41 males).Three radiologists evaluated the nodules based on a four-degree elasticity scoring system.The nodules were classified according to the ES as soft(ES 1-2) or hard(ES 3-4).The SR was calculated online. Results The sensitivity and specificity of the ES for thyroid cancer diagnosis were 78%and 80%,respectively.SR values > 2.9 used as a standard to distinguish benign from malignant nodules had a sensitivity of 87%and a specificity of 92%.The SR of the benign lesions was 1.64±1.37,which was significantly different from that of malignant lesions,which was 4.96±2.13(P<0.01). Conclusions Both the ES and SR were higher in malignant nodules than those in benign ones.Real-time US-E was a useful index in the differential diagnosis of thyroid solid nodules.It can provide quantitative information on thyroid nodule characterization and improve diagnostic confidence.

Real-time haptic model for soft tissue deformation in surgery simulation

The modelling and simulation of deformable objects is a challenging topic in the field of haptic rendering between human and virtual environment.In this paper,a novel and efficient layered rhombus-chain-connected haptic deformation model based on physics is proposed for an excellent haptic rendering.During the modelling,the accumulation of relative displacements in every chain structure unit in each layer is equal to the deformation on the virtual object surface,and the resultant force of corresponding springs is equivalent to the external force.The layered rhombus-chain-connected model is convenient and fast to calculate,and can satisfy real-time requirement due to its simple nature.Simulation experiments in virtual human liver based on the proposed model are conducted,and the results demonstrate that our model provides stable and realistic haptic feeling in real time.Meanwhile,the display result is vivid.

Virtual Huanghe River System:Framework and Technology

Virtual Reality provides a new approach for geographical research. In this paper, a framework of the Virtual Huanghe （Yellow） River System was first presented from the view of technology, which included five main modules——data sources, 3D simulation terrain database, 3D simulation model database, 3D simulation implementation and application system. Then the key technoiogies of constructing Virtual Huanghe River System were discussed in detail： 1） OpenGL technology, the 3D graphics developing instrument, was employed in Virtual Huanghe River System to realize the function of dynamic real-time navigation. 2） MO and OpenGL technologies were used to make the mutual response between 3D scene and 2D electronic map available, which made use of the advantages of both 3D scene and 2D electronic map, with the macroscopic view, integrality and conciseness of 2D electronic map combined with the locality, reality and visualization of 3D scene. At the same time the disadvantages of abstract and ambiguity of 2D electronic map and the direction losing of virtual navigation in 3D scene were overcome.

A Selective Moving Window Partial Least Squares Method and Its Application in Process Modeling

A selective moving window partial least squares(SMW-PLS) soft sensor was proposed in this paper and applied to a hydro-isomerization process for on-line estimation of para-xylene(PX) content. Aiming at the high frequency of model updating in previous recursive PLS methods, a selective updating strategy was developed. The model adaptation is activated once the prediction error is larger than a preset threshold, or the model is kept unchanged.As a result, the frequency of model updating is reduced greatly, while the change of prediction accuracy is minor.The performance of the proposed model is better as compared with that of other PLS-based model. The compromise between prediction accuracy and real-time performance can be obtained by regulating the threshold. The guidelines to determine the model parameters are illustrated. In summary, the proposed SMW-PLS method can deal with the slow time-varying processes effectively.

Research on the measurement of belt speed by video in coal mine based on improved template matching algorithm

In order to improve the intelligence of video monitoring system of belt and make up the deficiency of higher failure rate and bad real-time performance in the traditional systems of measurement of belt speed, according to the fact that the light of coal mine is uneven, the strength of light changes greatly, the direction of belt movement is constant, and the position of camera was fixed, various algorithms of speed measurement by video were studied, and algorithm for template matching based on sum of absolute differences （SAD） and correlation coefficient was proposed and improved, besides, the tracking of feature regions was realized. Then, a camera calibration method using the invariance of the cross-ratio was adopted and the real-time measurement of belt speed by the hardware platform based on DM642 was realized. Finally, experiment results show that this method not only has advantages of high precision and strong anti-jamming capability but also can real-time reflect the changes of belt speed, so it has a comprehensive applicability.

Stability and remote real-time monitoring of the slope slide body in the Luoshan mining area

Landslides have occurred frequently in the Luoshan mining area because of disordered mining.This paper discusses the landforms and physiognomy,hydro-meteorology,formation lithology,and geologic structure of the Luoshan mining area.It also describes the factors influencing the slope stability of landslide No.Ⅲ,determines the general parameters and typical section plane,analyzes the stress-strain state of the No.Ⅲ slope,and calculates its safety factors with FLAC3 D under saturated and natural conditions.Based on a stability analysis,a remote real-time monitoring system was applied to the No.Ⅲ slope,and these monitoring data were collected and analyzed.

Micro-failure process and failure mechanism of brittle rock under uniaxial compression using continuous real-time wave velocity measurement

In this study,the micro-failure process and failure mechanism of a typical brittle rock under uniaxial compression are investigated via continuous real-time measurement of wave velocities.The experimental results indicate that the evolutions of wave velocities became progressively anisotropic under uniaxial loading due to the direction-dependent development of micro-damage.A wave velocity model considering the inner anisotropic crack evolution is proposed to accurately describe the variations of wave velocities during uniaxial compression testing.Based on which,the effective elastic parameters are inferred by a transverse isotropic constitutive model,and the evolutions of the crack density are inversed using a self-consistent damage model.It is found that the propagation of axial cracks dominates the failure process of brittle rock under uniaxial loading and oblique shear cracks develop with the appearance of macrocrack.