特厚煤层综放采动底板变形破坏规律的综合实测

为了探究兖州煤田兴隆庄煤矿特厚煤层综放开采对底板岩层的变形破坏规律,应用钻孔应变感应法和超声成像技术对该矿某综放工作面进行了综合实测,获得了底板下不同深度应变增量随工作面推进的变化曲线和工作面推进过程中不同深度钻孔超声成像图片资料。通过5个应变传感器监测数据和大量钻孔超声成像图片的关联对比分析,基本确定了该工作面采动底板扰动深度和矿压作用下支撑压力的影响范围。研究结果表明:①该工作面底板采动扰动深度约为19 m,具有较明显分带性,即可分为采动扰动破坏带和采动扰动变形带,带厚分别约为16 m和3 m;②采动扰动破坏带属于整体塑性变形,其强度条件已基本丧失,但采动扰动变形带仍以弹性变形为主,具有良好的承载条件和较强的抗渗强度;③采动矿压超前和滞后显现明显,其对底板影响程度具有由浅及深而减小的特征。该综合实测方法的成功应用不但为综放开采巷道支护、老空水防治等提供重要信息,而且对深部即将开采的下组煤能否安全带压采掘研究也将具有重要参考价值。

新环境背景下对企业经济管理规范化的思考与探究

新环境下,企业的发展面临着更加激烈的竞争,要想保持竞争力,实现高质量发展,需要企业实行规范化经济管理。规范化经济管理即贯彻执行技术标准、工作标准以及管理标准的过程,是提升企业管理水平和管理成效,助力企业健康可持续发展的有效措施。基于此,本文分析了新环境背景下企业管理模式发展现状,并就企业经济管理规范化进行探究。

Comparisons on RIEMS2.0's Ability to Simulate Multi-Year Mean Climate in Northern China with Two Model Domains

Regional Integrated Environment Modeling System Version 2.0 (RIEMS2.0) is now being developed by the Key Laboratory of Regional Climate-Environment for Temperate East Asia, Chinese Academy of Sciences. In order to test the sensitivity of the RIEMS2.0 model domain to simulate long-term climate and its change, and provide a basis for the further development and application of the model, the authors compared results between simulated and observed precipitation and surface-airtemperature using two model domains under different cumulus parameterization schemes. The model was driven by NCEP/NCAR re-analysis data with a simulation duration ranging from 1 January 1979 to 31 December 2007. There were no significant differences found in the spatial distributions of the simulated precipitation and surface-air-temperature, or interannual variations between the two model domains. There were, however, differences observed between the two model domain simulations of local sub-regions. The smaller model domain more accurately simulated precipitation, especially in summer (June, July, and August), and decreased the bias of surface-airtemperature, especially in winter (December, January, and February). The weak summer and winter monsoons simulated by the smaller model domain was a result of boundary forcings and may partially account for the improvements of this model.

Red blood cell distribution width is worthwhile when interpreted with other inflammatory markers

To the Editor In a recent issue of Journal of Geriatric Cardiology, we read the article by LIU, et al. with interest.~lJ They aimed to investigate whether red cell distribution width （RDW） had a relationship with mortality in elderly patients after percuta- neous coronary intervention （PCI）. The authors concluded that, RDW is an independent predictor of the increased in- termediate-term all-cause mortality in elderly patients after PCI. The easy availability of testing for RDW at no addi- tional cost may encourage its broader use in clinical practice We would like to thank the authors for their comprehensive contribution.

Ventilation and climate simulation with the Multiflux code

Multiflux, a new thermal, hydrologic, and airflow model and software was being employed to solve the flow of heat, moisture, and air in and around an underground opening. The airway domain was solved with an integrated-parameter Computational Fluid Dynamic （CFD） module, which is an embedded part of the Multiflux code. The CFD model includes convection, conduction, and radiation for heat, as well as convection and diffusion for moist-ure transport in an air-filled opening. The surrounding rockmass model may be from any analytical solution, or from a complex thermal-hydrologic numerical model such as NUFT or TOUGH2. The rockmass model is interfaced to Multiflux using a novel technique called Numerical Transport Code Functionalization （NTCF）. The purpose was to briefly describe the Multiflux model and show four example applications. The first example reports the results of Multiflux simulations for a mine drift, comparing calculations with CLIMSIM, a well known mine climate software, and with measured data. The second and third examples involve development ends in two coal mines. Another development-end ventilation model in Multiflux is also shown as the 4th example compared with field measurements from the Lucky Friday Mine in Idaho, USA for comparison.The results of the study show very good agreement between the Multiflux model and the available measured field results.

Bamboo Winding Composite Utility Tunnels:a case study on mechanical behavior with WSN monitoring and numerical simulation

Bamboo Winding Composite Pipes(BWCPs)have many advantages such as good mechanical properties,low cost,low carbon,environmental friendliness,thermal insulation and easy installation et al.At present,BWCP is widely used in urban water supply,drainage,communication cable protection,farmland irrigation etc.It is obvious that the Bamboo Winding Composite materials have good application prospects in the field of utility tunnels.However,considering that the size of utility tunnels is much larger than that of normal pipelines,the wide application of Bamboo Composite Utility Tunnels(BCUTs)is still a challenge.In this paper,the force performance of BCUT in Datong Shanxi Province,was studied using two methods:real time monitoring and numerical simulation.Wireless sensor networks were used for monitoring,and the real time monitoring data of horizontal convergence and strains under the condition of backfill were obtained.The monitoring data indicated that the horizontal convergence can meet the requirement of relevant technical standards.A three-dimensional numerical model of the utility tunnel was established using FEM software.The influence of soil parameters on the deformation and strain of the BCUT was studied using the numerical method.The simulation results were compared with real-time monitoring data.The soil parameters K_(0) and k_(sh) have significant effects on the deformation,stress and strain of the utility tunnel.This kind of utility tunnel is recommended to use in areas with relatively good geological conditions.

采动底板岩性及组合结构对破坏深度的制约作用

为了探究底板岩性及组合结构这一因素对采动底板变形破坏深度的影响,通过现场大量实测资料的整理分析,获得了类似均质底板和软硬岩不同组合结构底板在采动矿压作用下差异性变形破坏特征。研究结果表明:1)类似均质底板变形破坏规律相对简单,底板采动变形破坏深度主要受制于底板岩体的抗压破坏强度,总体上这种类型底板变形破坏程度具有自上至下呈由强及弱的渐次性变化特点;2)软硬岩夹层或互层底板采动变形破坏特征比较复杂,这种组合结构对底板采动变形破坏深度和程度均具有明显的控制作用,其中软弱夹层对底板破坏深度具有较强的约束效应,即软岩对上覆硬岩起到了重要的"褥垫效应",对下伏岩层产生"应力扩散效应"。研究结果揭示了底板岩性及组合结构对变形破坏深度具有重要的制约作用,对巷道支护和底板水防治均具有重要的理论和实际意义。