道岔尖轨密贴和开程的动态检测方法研究

针对道岔尖轨密贴和开程的动态位移检测问题,采用具有磁致伸缩效应的位移测量技术,在道岔牵引点的定/反位分别安装位移传感器进行尖轨位移的全程动态测量,并对测量数据进行校准、保存、分析和显示。经现场试验验证:该动态检测方法能够满足道岔尖轨位移动态检测功能和性能的要求,为道岔的日常运用维护提供了有力的技术保障手段。

Design and Implementation of an FDP Chip

A novel Fudan programmable logic chip （FDP） was designed and implemented with a SMIC 0. 18μm CMOS logic process. The new 3-LUT based logic cell circuit increases logic density about 11% compared with a traditional 4-input LUT. The unique hierarchy routing fabrics and effective switch box optimize the routing wire segments and make it possible for different lengths to connect directly. The FDP contains 1,600 programmable logic cells, 160 programmable I/O, and 16kbit dual port block RAM. Its die size is 6. 104mm× 6. 620mm, with the package of QFP208. The hardware and software cooperation tests indicate that FDP chip works correctly and efficiently.

Singular Perturbation of Two Points Boundary Value Problems for a Class of Third Order Quasilinear Differential Equations

In this paper, the fixed-point Theorem i s used to estimate an asymptotic solution of boundary value problems for a class o f third order quasilinear differential equation and the uniformly valid asymptot ic expansion of solution of any orders including boundary layer is obtained.

Open multilevel hierarchic intelligent control system for eco-industrial system

In allusion to the characteristics of the open complex giant system, an open multilevel hierarchic intelligent control system is established for the eco-industrial system. With the idea of the open engineering system, using the hall for workshop of metasynthetic engineering （HWME）, intelligent control techniques, the expert system and the design of experiments are integrated within the framework of the nonlinear multiobjective decision support system to develop a robust, top-level design specification so as to make the system have the quality of adaptive control, self-organizing, self-learning and robustness. Finally, an illustrative example is given to clarify the effectiveness of the method.

Analysis on fatigue cracking for asphalt surface layers based on field cores

Field cores from typical cracking locations were tested by the semi-circular bending test and the digital image correlation method to evaluate the anti-fatigue performance of different asphalt pavements. Test results were analyzed by different fatigue models. Causes of fatigue cracking for different pavement sections were determined by extraction and sieving test results. It is found that the ranking （from high to low） in terms of the anti-fatigue performance for field cores is the crumb rubber modified asphalt mixture, densegraded modified asphalt mixture, continuous graded asphalt treated base, gap-graded stone asphalt concrete, and half open-graded asphalt macadam. Compared with the half opengraded asphalt macadam, the fatigue life of the crumb rubber modified asphalt mixture improves by 2. 0 to 3. 8 times. Fatigue lives of different mixtures and distress ratios of actual pavements can be accurately predicted by the dissipated energy density ratio. Causes of fatigue cracking vary with mixture types.

Integrated application of 3D seismic and microseismic data in the development of tight gas reservoirs

The development of unconventional resources, such as shale gas and tight sane gas, requires the integration of multi-disciplinary knowledge to resolve many engineering problems in order to achieve economic production levels. The reservoir heterogeneit3 revealed by different data sets, such as 3D seismic and microseismic data, can more full3 reflect the reservoir properties and is helpful to optimize the drilling and completioT programs. First, we predict the local stress direction and open or close status of the natura fractures in tight sand reservoirs based on seismic curvature, an attribute that reveals reservoi heterogeneity and geomechanical properties. Meanwhile, the reservoir fracture network is predicted using an ant-tracking cube and the potential fracture barriers which can affec hydraulic fracture propagation are predicted by integrating the seismic curvature attribute anc ant-tracking cube. Second, we use this information, derived from 3D seismic data, to assis in designing the fracture program and adjusting stimulation parameters. Finally, we interpre the reason why sand plugs will occur during the stimulation process by the integration of 3E seismic interpretation and microseismic imaging results, which further explain the hydraulic fracure propagation controlling factors and open or closed state of natural fractures in tigh sand reservoirs.

Simulation and Analysis of Flexible Solar Panels' Deployment and Locking Processes

To predict the attitude of satellite during the whole deployment process and evaluate the locking impact, a numerical flexible model of a certain satellite associated with four flexible honeycomb solar panels was established. The flexible solar panel was modeled by the finite element analysis (FEA), and the motion equations were derived by Lagrangian formulation. The locking process was based on the method of Hertzian contact, which enables one to predict the locking impact on the satellite and the subsequent oscillation of solar panels. The results reveal that locking operation has great impact on the attitude of the satellite, and the angular acceleration of satellite reaches 22.03°/s2 at the locking moment; the flexible solar panels model is feasible to predict the accurate response of the satellite during deployment and the oscillation of solar panels; the instantly impulsive force occurred during locking process is about 1.5 kN and the changing time is nearly 0.32 s. It provides an effective approach to present the flexible solar panels' deployment process and evaluate the locking impact.

Multiscale Simulation Starting at the Molecular Level for Adsorption Process Development

This article presents a multiscale simulation approach starting at the molecular level for the adsorption process development. A grand canonical Monte Carlo method is used for the prediction of adsorption isotherms of methanol on an activated carbon at the molecular level. The adsorption isotherms obtained in the linear region （or adsorption constant） are exploited as a model parameter required for the adsorption process simulation. The adsorption process model described by a set of partial differential equations （PDEs） is solved by using the conservation element and solution element method, which produces a fast and an accurate numerical solution to PDEs. The simulation results obtained from the adsorption constant estimated at the molecular level are in good agreement with the experimental results of the pulse response. The systematical multiscale simulation approach addressed in this study may be useful to accelerate the adsorption process development by reducing the number of experiments.

Applications of Computer Algebra in Solving Nonlinear Evolution Equations

With the use of computer algebra, the method that straightforwardly leads to travelling wave solutions is presented. The compound KdV-Burgers equation and KP-B equation are chosen to illustrate this approach. As a result, their abundant new soliton-like solutions and period form solutions are found.

Blow-up for a Class of Degenerate Reaction-diffusion Equation with Nonlocal Source

This paper deals with the properties of the solution to a class of nonlocal degenerate reaction-diffusion equation with nonlocal source,subject to the null Dirichlet boundary condition.We first give sufficient conditions for that the solution exists globally or blows up in the finite time.Then the blow-up time is also given.At last,we obtain a property differing from the local source which the blow-up set is the entire interval.

Design and application of solid, dense backfill advanced mining technology with two pre-driving entries

New solid backfill mining technology provides unique technical advantages for ‘‘three-under'' coal mining which refers to coal resources trapped under buildings, railways, and water bodies. This technology has a much higher recovery rate and can effectively control the surface subsidence. However, successful application of this technology depends heavily on geological conditions. To avoid the disadvantages associated with downward mining and overhead backfilling with this new technology, a new advanced solid backfill mining design with two pre-driving entries is proposed here to ensure the backfill effect. Taking Huayuan coal mine as an example, this paper tests the double gob-side entries retaining with no pillar left scheme and optimizes an integrated technology setup for backfill mining and gob-side entry retaining. Field applications show that the recovery rate increased from 40% for strip mining to 85% for backfill mining. Moreover, the new backfill technology allowed for better control over the surrounding rock deformation caused by the gob-side entry retaining effect and better control of ground subsidence as compared to strip mining.

Sensing for advancing mining automation capability:A review of underground automation technology development

This paper highlights the role of automation technologies for improving the safety, productivity, and environmental sustainability of underground coal mining processes. This is accomplished by reviewing the impact that the introduction of automation technology has made through the longwall shearer automation research program of Longwall Automation Steering Committee(LASC). This result has been achieved through close integration of sensing, processing, and control technologies into the longwall mining process. Key to the success of the automation solution has been the development of new sensing methods to accurately measure the location of longwall equipment and the spatial configuration of coal seam geology. The relevance of system interoperability and open communications standards for facilitating effective automation is also discussed. Importantly, the insights gained through the longwall automation development process are now leading to new technology transfer activity to benefit other underground mining processes.

Development and application of an instrument for simulating wetting-drying cycles of expansive soils under loads

Alternating rainfall and evaporation in nature severely impact the shear strength of expansive soils. This study presents an instrument for simulating the effect of wetting–drying cycles on the strength of expansive soils under different loads, and its testing error is verified. With this instrument,direct shear tests were performed on samples experiencing 0-6 cycles under vertical loads of 0 kPa,5 kPa, 15 kPa, and 30 k Pa. The results found that this instrument provides a new method for evaluating the effects of wetting–drying cycles on soils, and this method represents actual engineering conditions more accurately than do preexisting methods. It accurately controls the water content within 1% while simulating the specified loads at different soil depths.Cohesion is significantly affected by wetting–drying cycles, while the friction angle is not as sensitive to these cycles. Decrease in shear strength can be attributed to the fissures in soils caused by wetting–drying cycles. The existence of vertical loads effectively restricts shrinkage fissuring and cohesion attenuation, consequently inhibiting the attenuation of shear strength.

Research on microseismic activity rules in Sanhejian Coal Mine

By the microseismic (MS) monitoring system of Sanhejian Coal Mine,the detail MS activity rules in the entire mining process of 9202 strong rockburst working face were studied,following main conclusions were obtained.(1) The strong correlation between MS activity and the region stress gradient was revealed.The higher the region stress gradient, the stronger the MS signal is,and the frequency-spectrum moves to lower frequency band the amplitude begins to add gradually.(2) The different types of MS signals have the cor- responding frequency-spectrum character.Such as relieve-shot MS signal shows the wide frequency-spectrum,multi-peak high frequency character,while rockburst omen signal shows the low frequency and amplitude,the mainshock signal has relatively higher fre- quency and amplitude.(3) To monitor and recognize rockburst dangerous region,the strong consistence between the MS signal intensity and the amplitude of electromagnetic emission (EME) signal and drilling bits measured was observed.On above,the weakening and controlling technology of MS intensity was put forward.

Study on water resisting property of subsurface aquiclude in shallow coal seam mining

According to the characteristic of clay aquiclude of overburden,the proper simulation materials and proportions of mixture for simulating the plastic clay aquiclude layers were developed,and the plastic similarity conditions were setup.Thus,the simili- tude and simulation method in whole stress-strain was progressed.Furthermore,the simulation condition and material proportions in water reaction property and crack closing property were also put forward.Based on systematical tests,the development and distri- bution of mined cracks in roof and subsurface aquiclude was found and the stability of aquiclude was analyzed at all.At last,the key section and key index of aquclude stability was advanced.It is found that the movement of clay aquiclude follows the movement of the underlying bedrock layers.The basic caving mechanism of the overburden roof strata was also presented.

Development of Sustainable Solutions for Zebra Mussel Control Through Chemical Product Engineering

The zebra mussel is an important aquatic pest that causes great damage to freshwater-dependent industries, due to biofouling. The main goal of the project discussed here is to develop improved solutions to control this species. Three approaches have been explored in an attempt to design innovative application strategies for existing biocides： （i） encapsulation of toxins; （ii） combination of toxins; （iii） investigation of the seasonal variation of the species＇ tolerance to toxins. In this paper, the principles behind these approaches and the major results on each topic are presented. The benefits of adopting a chemical product engineering approach in conducting this project are also discussed.

Automatically positioning microseismic sources in mining by the stereo tomographic method using full wavefields

For microseisimic monitoring it is difficult to determine wave modes and their propagation velocity. In this paper, we propose a new method for automatically inverting in real time the source characteristics of microseismic events in mine engineering without wave mode identification and velocities. Based on the wave equation in a spherical coordinate system, we derive a tomographic imaging equation and formulate a scanning parameter selection criterion by which the microseisimic event maximum energy and corresponding parameters can be determined. By determining the maximum energy positions inside a given risk district, we can indentify microseismic events inside or outside the risk districts. The synthetic and field examples demonstrate that the proposed tomographic imaging method can automatically position microseismic events by only knowing the risk district dimensions and range of velocities without identifying the wavefield modes and accurate velocities. Therefore, the new method utilizes the full wavefields to automatically monitor microseismic events.

Heavy metal pollution model of tailings and the pollution simulation by visualization

Based on the analysis of whole mining process in metal mines, it was pointed out that the investigation of the heavy metal pollution of tailings should be taken as an important project for a metal mine. Combined with the anlysis of the characteristics of tailings, it is found that the transformation of the heavy metal dissolution process, the heavy metal ions migration with groundwater and the heavy metal transport in porous media are three key aspects. Accordingly, the models of heavy metal pollution were established with providing boundary conditions. Depending upon a case of Ibnglushan Copper Mine railings and its relevant area from Google maps＇, a three-dimensional grid view of the tailings was set up. By application of Fluent software, the contaminated process of the heavy metal pollutants in the tailings was shown through digital visualization pattern.

Transitional geology and its effects on development and longwall mining in Pittsburgh Seam

This paper presents the geologic and ground control challenges that were encountered by Consol Energy＇s coal mining operations in southwestem Pennsylvania, USA. Geologic encounters, such as sandstone- to-limestone geology transition, massive sandstone channels, shale channels, pyritic rich green claystone, laminated roof, and soft floor, have significantly impacted the development and longwall mining in Consol＇s Pittsburgh Seam coal mines. Experience from different mines shows that, in the sandstone-to-limestone geology transition zone, 1.83 m high-tension, fully-grouted primary bolts employed along with 4.88 m cen- ter cable bolts at every other strap greatly improved beam building and ensured proper anchorage into the competent roof. Hydraulic fracturing of the massive sandstone was often necessary to enhance caving of the massive sandstone behind the shields to relieve pressure at the face. The presence of soft floor coupled with presence of thick floor coal and deep cover, induced excessive headgate convergence during retreat of the first right hand longwall panel. In all, it is important to explore the roof and in-seam geology in detail to delineate normal and anomalous geologic conditions prior to and during development. With diligent geologic reconnaissance, geotechnical monitoring, and assessment, site-specific geotechnical solutions have been provided to mine operations to improve safety and productivity.

3D deformation effect and optimal excavated design of surface mine

The three-dimensional （3D） deformation effect of the slope engineering under the step-by-step excavation for the Antaibao surface mine was analyzed using the FLAC^3D technique. An optimal excavated scheme with a relatively steeper slope angle of 47° instead of 30° was successfully implemented at the west wall in the geological section 73200 of the mine area, where the 3D effect of the nonlinear large deformation of the slope was taken into account. Based on the above research conclusion, put forward the countermeasures of shortening mining length, excavating by different regions, timely foot backfilling to protect the excavated slope, and monitoring and feedback adjustment by studying the nonlinear effect. The results show that these countermeasures are effective in controlling maximum deformation and increasing the stability of the slope.