凉水井矿综采工作面粉尘运移规律数值仿真

为研究凉水井矿42112综采工作面粉尘运移规律,基于Fluent数值仿真软件,选用标准k-epsilon湍流模型以及DPM计算模型建立了气-固两相流的粉尘运移数学和物理模型。用数值仿真及现场实测的方法研究了凉水井矿综采工作面风流运动情况,以及在移架和割煤时粉尘的运移规律和悬浮时间。研究表明:风流沿工作面在速度上表现出"小-大-小"的规律,速率和湍流强度在采煤机附近达到最大,在人行道空间有一定的低值区域。移架产生的粉尘一部分随风流运动,另一部分因粒径不同沉降到巷道底板不同位置。采煤机割煤产生的大粒径粉尘在重力作用下逐渐沉降,小粒径粉尘随气流继续运动,粉尘浓度最大处为前后滚筒附近及后滚筒下风向10 m左右靠近煤壁一侧区域,但扩散性不大,随着粉尘团向后移动,影响范围不断扩大,直至向整个工作面弥散。综采工作面粉尘在距底板1 m处粉尘浓度最高且分布范围最广,在巷道上部空间,直径大于100μm的粉尘粒子迅速沉降,而随着粒径减小,粉尘悬浮时间也逐渐延长。本研究可为综采工作面除尘、抑尘提供参考。     

梁北矿大采高松软突出煤层工作面综合防尘技术

分析了梁北矿11081工作面粉尘分布特点,通过理论分析和现场测试,定性给出了大采高松软突出煤层综采工作面的产尘特点和扩散规律,分析了煤壁垮落产尘特点和采煤机割煤产尘中粉尘分布特征。提出综采工作面三维"立体"控尘、防尘技术,即含尘气流控制技术、采煤机高压外喷雾降尘技术和采煤机尘源跟踪降尘技术相结合的综合防尘技术。在原有降尘措施基础上降尘效率提高了82.2%,使得工作面工作环境得到了很大的改善。     

普采工作面呼吸性粉尘浓度分布的数学模型

普采工作面是煤矿主要尘源之一,而采煤机滚筒割煤是普采工作面粉尘的主要来源.将采煤机滚筒简化成沿高度方向的连续集中线源,依据扩散理论,建立滚筒割煤时呼吸性粉尘扩散的数学模型.结合工作面物理模型,得出工作面呼吸性粉尘浓度分布的表达式.通过计算实例,分析了普采工作面呼吸性粉尘浓度分布规律及其影响因素.     

综采割煤粉尘运移影响因素的数值模拟

为解决综采割煤粉尘质量浓度高的问题,获取粉尘控制的合理参数,改善作业环境,以邢东矿2225工作面为研究背景,依据气固两相流理论,运用Fluent软件对综采工作面割煤粉尘运动规律进行数值模拟,并与现场实测的粉尘质量浓度分布情况进行对比分析,模拟结果与实际数据基本一致.研究结果表明:工作面风速、采煤机滚筒转速、溜子速度以及壁面条件是影响综采工作面粉尘质量浓度分布的几个重要因素.当工作面平均风速在1.4m·s-1,滚筒转速不超过2.5rad·s-1,溜子速度不超过1.5m·s-1,防降尘效果最佳.同时洒水保持煤壁湿润也起到一定的捕尘作用.     

采煤机截割粉尘扩散运移规律的试验研究

采煤机割煤滚筒旋转形成涡旋风流是导致割煤截割粉尘扩散运移的直接原因.通过对成庄煤矿某综放工作面采煤机割煤滚筒受限空间截割粉尘现场实测,分析研究截割粉尘在不同条件下扩散运移的基本规律,得出无论是顺风割煤还是逆风割煤,涡旋风流场对截割粉尘的作用主要发生在割煤滚筒靠近采煤机机身侧的下1/4圆周区域,并使该区域顺风割煤时截割呼吸性粉尘质量浓度达到95 mg/m~3,逆风割煤时呼吸性粉尘质量浓度达到110mg/m~3,远远高于国家有关标准和要求.     

综放工作面粉尘运动的数值模拟及试验研究

运用气固两相流动理论建立了粉尘颗粒的离散型数学模型,采用Fluent软件,对成庄矿3309综放工作面的粉尘运动分布规律进行了数值模拟和实测.结果表明:利用数值模拟方法可以得到粉尘颗粒的运动分布特征,工作面割煤、移架、放顶煤各工序过程粉尘的浓度分布规律不同,粉尘浓度出现最大值的位置不同,难以沉降的呼吸性粉尘的分布区域也不同;经对比实测数据与模拟结果较为一致.研究结果可以为现场防尘技术措施提供理论性指导.     

浅谈综采工作面大倾角浅截深割煤控制顶板工艺

详细介绍了综采工作面大倾角浅截深割煤控制顶板工艺，包括浅截深割煤操作工序，采煤机割煤工序，浅截深割煤的移架工艺，并分析了浅截深往复单循环作业的优点。     

综采面架间喷雾引射除尘技术

为了有效解决综采面采煤机割煤及液压支架移架产尘难以控制的难题,根据喷雾引射除尘机理、采煤机及液压支架结构、产尘特点,对综采面架间喷雾引射除尘技术进行研究;在12种空心和实心锥形喷雾场喷嘴中,实验选定综合雾化性能(包含雾化角、有效射程及雾滴粒径)最优的喷嘴。研究结果表明:最佳喷雾压力为8 MPa,在该压力下,架间喷雾引射除尘技术形成的喷雾场可基本完全覆盖煤壁至液压支架立柱的空间区域,总吸风量为22.03 m3/min,可有效吸入人行道处的含尘气流;相对采取原有除尘措施,综采面全尘和呼尘的降尘率平均值分别提高26.2%和27.3%,移架工处全尘和呼尘的降尘率分别提高30.6%和31.9%。     

综采面自动定位智能喷雾降尘控制系统

分析综采面的特点和采煤工艺流程,根据其粉尘扩散运动规律及降尘要求,采用软件调试及模拟运行的方法,设计一套综采面自动定位智能喷雾降尘控制系统,以改善煤矿井下综采面的工作环境。系统通过红外线收发器自动采集采煤机位置信息,无线触控传感器自动采集移架和放煤位置信息,根据设置参数控制数道喷雾组件开启喷雾。现场运行试验表明,系统能够在综采面架间、移架作业、放煤作业时自动喷雾以及井下自动照明。     

采煤机参数与工作面环境及安全关系

通过对煤矿尘源的分析可知,截割粉尘是采掘工作面粉尘的根源;而截割粉尘扩散到工作面并悬浮在空气中,成为影响工作面环境及安全的主要因素,从而得出采煤机的参数与工作面的环境及安全之间的关系,并将采煤机参数和工作面环境及安全联系起来,为设计新型、环保型、安全型的采煤机提供理论依据,并从根本上来改善工作面环境和提高工作面的安全.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.