金属化球团工艺系统还原风机转子失衡故障分析与风机现场动平衡技术的应用

本文主要介绍了金属化球团工艺系统还原风机的工况,分析了该工艺下还原风机转子失衡故障的主要原因,提出了预防还原风机转子失衡振动故障的方案,并对风机现场动平衡技术应用进行了介绍。

衡扭矩技术在钻井工程中的应用

面对钻井工程中软硬交替等复杂地层中PDC钻头十分容易发生卡钻、崩齿、断脱的技术难题,提出衡扭矩技术的应用思路,对该技术工具配置、工作原理、执行机构等展开分析,并对其在试验井中的应用过程及效果进行阐述探析。结果表明,PDC钻头衡扭矩工具以碟簧蓄能装置和螺旋化键短节为主体,具备钻压自动调整功能,可确保钻头匀速转动,避免卡钻蹩滑等情况发生;有利于维护井下工具仪器的运行安全,可在我国井深与地层复杂程度较大的油井推广应用。

世界技术不平衡发展测度及其对经济增长的影响

在使用泰尔指数测度世界技术不平衡发展的基础上,可以尝试运用时间序列模型来分析世界技术不平衡发展对世界经济增长的影响。世界技术不平衡发展的程度呈现上升的态势,在按经济发展程度两区域划分标准下,区域间技术不平衡对世界技术不平衡发展的作用更大,而区域内技术不平衡对世界技术不平衡发展的作用较小,世界技术不平衡发展有助于全球、发达地区和不发达地区的经济增长,世界技术不平衡发展的程度每提高1%,将分别导致全球经济增长0.189%,发达地区经济增长0.351%,不发达地区经济增长0.258%。为了增大世界技术不平衡发展对经济增长的促进作用,发达地区和不发达地区均应逐步放松高级人才和资金流动限制,这样才有利于获得创新资源的集聚效应,降低创新风险,实现技术创新并促进经济增长。

制药企业水平衡测试技术的应用分析

水平衡测试技术能够促进制药企业节约用水并解决企业用水管理不足和水资源浪费的问题。利用水平衡测试技术,有利于制药企业结合自身的实际情况,采取相应的措施节约用水并解决企业内部用水管理存在的问题。本文详细分析了水平衡测试技术的原理及要点,详细阐述了制药企业水平衡测试技术的具体应用。

ICS-FH型浮衡皮带秤的设计与应用——一种自由浮动的计量设备

皮带秤高精度测量的关键是称重桥架将皮带上的物料重量全部、准确的传递给称重传感器,传递过程没有任何干扰力。目前,多托辊皮带秤秤架结构有单杠杆式、双杠杆式、悬浮式等多种结构形式,称重传感器与秤架的连接多采用刚性连接,其中多数设有水平力、侧向力限位装置,这种限位连接形式存在一定的限制力、结构内应力,该限制力、结构内应力无法很好释放,容易产生过定位,干扰了重力的准确测量,特别是小重力或重力变化小的情况,干扰影响尤为突出,无法提供高精度的称重计量。

Strategic equilibrium price analysis and numerical simulation of preponderant high-tech metal mineral resources

Based on exploitation compensation value system of preponderant high-tech metal mineral resources and distortion of pricing mechanism, social utility function was constructed to modify decision utility function of developers, and was extended to Stackelberg production decision model of preponderant high-tech metal mineral resources development. Analyzing the influences on market monopoly, output and price decision-making exerted by altruistic preferences, inequity aversion and sequential reciprocity fairness belief equilibrium, game fairness equilibrium which is significant in experimental economics can be obtained and verified by numerical simulation. In process of strategic pricing, method that uses the variation of producer surplus to measure strategic value from psychological preferences was proposed for the first time and technical support to improve exploitation compensation value system of preponderant metal mineral resources was available.

Study on online elimination of sudden unbalance-induced vibration using active balancing technology

An active balancing technology has been applied to solve the severe vibration caused by sudden unbalance in rotating machineries during their working process. First, based on the generation principle of sudden unbalance, a simulation test stand with a sudden unbalance generation device was set up. Then, the balancing planes were optimized by using the finite element method （FEM） to determine the position for balancing device installation. Finally, the active balancing experiments were carried out on the test stand. The experimental results indicate that the vibration response caused by sudden unbalance can be decreased from 77μm to 8μm by using the active balancing device, and the vibration amplitude reduction was up to 89.6%. From this example, it can be concluded that the active balancing device, which is installed on a proper position of the rotor, can effectively control the random transient synchronous vibration, demonstrating its high value in engineering practice.

Area-Efficient Low Power CMOS Image Sensor Readout Circuit with Fixed Pattern Noise Cancellation

A low cost of die area and power consumption CMOS image sensor readout circuit with fixed pattern noise(FPN) cancellation is proposed.By using only one coupling capacitor and switch in the double FPN cancelling correlative double sampling(CDS),pixel FPN is cancelled and column FPN is stored and eliminated by the sampleand-hold operation of digitally programmable gain amplifier(DPGA).The bandwidth balance technology based on operational amplifier(op-amp) sharing is also introduced to decrease the power dissi...

Equalization for continuous phase modulation over frequency-selective fading channels

This paper presents an equalization algorithm for continuous phase modulation （CPM） over frequency-selective channels. A specific training sequence is first embedded in each data packet. By recursive least-squares （RLS） estimation, the channel information parameters can be acquired, and a fractionally Simulation results show that the proposed algorithm can acquire the spaced equalizer performs joint decoding and equalization. channel information parameters rapidly and accurately, and that the fractionally spaced equalizer can eliminate the intersymbol interference （ISI） effectively, and is not sensitive to timing inaccuracy, so this algorithm can be exploited for demodulation system in burst mode.

Separation Efficiency of Thin-film Evaporators

The recovery of contaminants and useful substances from liquid wastes, thepurification of production effluents and the separation of thermally instable mixtures are some ofthe multivarious applications of thin-film distillers in many processes of the chemical and alliedindustries and of the food industries. In a study carried out in pilot plants with distillation testsystems there was found a good agreement between the experimental separation results and thoseobtained by computing with a theorectical model; the latter is based on the assumption of phaseequilibrium between the vapour formed on an infinitely small element of area in a liquid film of anygiven concentric periphery of the vertically arranged evaporator. These tests were perfomed undervarious phase loads.

A MICROPAYMENT SCHEME BASED ON WEIGHTED MULTI-DIMENSIONAL HASH CHAIN

Hash chain and its generalization—Multi-Dimensional Hash Chain (MDHC) have been widely used in the design of micropayment due to its simplicity and efficiency. In this letter, a more efficient variant of MDHC, called WMDHC, which endows in the structure of MDHC a weight value for each hash value through a well-defined mapping, is proposed. The average hash operation number of WMDHC is log(2 m / t ),which is better than log( m )of MDHC when the parameter t is typically suggested as t = 7.

Determination of Equilibrium Distribution Coefficients of Impurities in Phosphorus by Vertical Zone-melting Technique

The equilibrium distribution coefficients of 12 impurities （As,Fe,Ca,Co,Al,Cr,Cu,Mg,Mn,Ni,Pb,Zn） in phosphorus were obtained by measuring their effective distribution coefficients at zone travel rate of 3,5,10,15,and 20 mm·h-1 in the purification process with vertical zone-melting technique.The results indicate that the method is reliable.The equilibrium distribution coefficients are below 0.3 except arsenic.

Energy-Efficient Multi-UAV Coverage Deployment in UAV Networks:A Game-Theoretic Framework

UAV cooperative control has been applied in many complex UAV communication networks. It remains challenging to develop UAV cooperative coverage and UAV energy-efficient communication technology. In this paper, we investigate current works about UAV coverage problem and propose a multi-UAV coverage model based on energy-efficient communication. The proposed model is decomposed into two steps: coverage maximization and power control, both are proved to be exact potential games(EPG) and have Nash equilibrium(NE) points. Then the multi-UAV energy-efficient coverage deployment algorithm based on spatial adaptive play(MUECD-SAP) is adopted to perform coverage maximization and power control, which guarantees optimal energy-efficient coverage deployment. Finally, simulation results show the effectiveness of our proposed approach, and confirm the reliability of proposed model.

Local dynamic balance theory and technology of flow field in multilayer gob area

Flow field in multilayer gob area, which formed in small hiden-depth, multi-coal layer groups, close distance, hard coal layer, and hard roof, possesses characteristics such as complex, changeable and unstable. Dynamic balance theory of local flow field in multilayer gob area was built based on the realistic requirement that the serious threat on current mining coal layer by large-scale spontaneous combustion fire on close spontaneous combustion coal layer group of Datong Coal mining area at the ＇di-hard＇ conditions was caused by small coal pit mining. The kernel was in dynamic balance between flow field pressures of working face and local flow field in multilayer gob area was kept by transformation. Corresponding technology and set of devices were developed.

Liquidus and phase equilibria in CaO-SiO2-5%MgO-20%Al2O3-TiO2 system

The single hot thermocouple technique （SHTT） and high temperature equilibrium technique were combined to investigate the phase diagram of the CaO-SiO2-5%MgO-20%AlzO3-TiO2 system. The 1300 ℃ to 1500 ℃ liquidus lines are calculated according to the thermodynamic equations based on the pseudo-melting temperatures measured by the single hot thermocouple technique. The phase equilibria relationships are experimentally determined at 1400 ℃ using the high temperature equilibria technique followed by X-ray fluorescence （XRF）, X-ray diffraction（XRD）, scanning electron microscopy （SEM） and energy dispersive X-ray spectroscopy （EDX） analysis. The liquid phase（L）, melilite solid solution phase （（C2MSz,C2AS）ss）, diopside phase（CMS2） and perovskite phase （CaO·TiO2） are found. Coupled with the liquidus lines and equilibria results, the phase diagram is constructed for the specified region of the CaO-SiO2-5%MgO-20%Al2O3-TiO2 system.

Sorbitol Hydrogenolysis to Glycols over Baisic Additive Promoted Ni-based Catalysts

A series of Ni based catalysts with different supports and basic additives were prepared by sequential impregnation method. The catalysts were characterized by XRD, BET, H2-TPR and CO2-TPD techniques. It was found that the introduction of basic additives enhanced the basicities of catalyats and promoted the dispersities of Ni particles by strong interaction between Ni2＋ and basic additives. Among the Ni based catalysts, 10%Ni/10%La203/ZrO2 showed the superior performance in sorbitol hydrogenolysis. The synergistic effect of Ni and La203 was proven to play an essential role in selective synthesis of EG and 1,2-PG. In the optimal reaction condition, the catalyst presented 100% sorbitol conversion and over 48% glycols （EG and 1,2-PG） yield. The kinetics study of polyols （sorbitol, xylitol and glycerol） hydrogenolysis showed that polyols with more hydroxyl number have higher activity and products distribution was final results of kinetic balance, which could give us some inspiration abeut how to change the products selectivity.

A two-stage short-term traffic flow prediction method based on AVL and AKNN techniques

Short-term traffic flow prediction is one of the essential issues in intelligent transportation systems(ITS). A new two-stage traffic flow prediction method named AKNN-AVL method is presented, which combines an advanced k-nearest neighbor(AKNN)method and balanced binary tree(AVL) data structure to improve the prediction accuracy. The AKNN method uses pattern recognition two times in the searching process, which considers the previous sequences of traffic flow to forecast the future traffic state. Clustering method and balanced binary tree technique are introduced to build case database to reduce the searching time. To illustrate the effects of these developments, the accuracies performance of AKNN-AVL method, k-nearest neighbor(KNN) method and the auto-regressive and moving average(ARMA) method are compared. These methods are calibrated and evaluated by the real-time data from a freeway traffic detector near North 3rd Ring Road in Beijing under both normal and incident traffic conditions.The comparisons show that the AKNN-AVL method with the optimal neighbor and pattern size outperforms both KNN method and ARMA method under both normal and incident traffic conditions. In addition, the combinations of clustering method and balanced binary tree technique to the prediction method can increase the searching speed and respond rapidly to case database fluctuations.

Fog Computing Dynamic Load Balancing Mechanism Based on Graph Repartitioning

Because of cloud computing's high degree of polymerization calculation mode, it can't give full play to the resources of the edge device such as computing, storage, etc. Fog computing can improve the resource utilization efficiency of the edge device, and solve the problem about service computing of the delay-sensitive applications. This paper researches on the framework of the fog computing, and adopts Cloud Atomization Technology to turn physical nodes in different levels into virtual machine nodes. On this basis, this paper uses the graph partitioning theory to build the fog computing's load balancing algorithm based on dynamic graph partitioning. The simulation results show that the framework of the fog computing after Cloud Atomization can build the system network flexibly, and dynamic load balancing mechanism can effectively configure system resources as well as reducing the consumption of node migration brought by system changes.