Insights into carbon dioxide sequestration into coal seams through coupled gas flow-adsorption-deformation modelling

Injecting carbon dioxide(CO_(2))into coal seams may unlock substantial carbon sequestration potential.Since the coal acts like a carbon filter,it can preferentially absorb significant amounts of CO_(2).To explore this further,desorption of the adsorbed gas due to pressure drop is investigated in this paper,to achieve an improved understanding of the long-term fate of injected CO_(2) during post-injection period.This paper presents a dual porosity model coupling gas flow,adsorption and geomechanics for studying coupled processes and effectiveness of CO_(2) sequestration in coals.A new adsorption?desorption model derived based on thermodynamics is incorporated,particularly,the desorption hysteresis is considered.The reliability of the proposed adsorption-desorption isotherm is examined via validation tests.It is indicated that occurrence of desorption hysteresis is attributed to the adsorption-induced pore deformation.After injection ceases,the injected gas continues to propagate further from the injection well,while the pressure in the vicinity of the injection well experiences a significant drop.Although the adsorbed gas near the well also decreases,this decrease is less compared to that in pressure because of desorption hysteresis.The unceasing spread of CO_(2) and drops of pressure and adsorbed gas depend on the degree of desorption hysteresis and heterogeneity of coals,which should be considered when designing CO_(2) sequestration into coal seams.

基于SEAMS评估的针对性护理干预在老年高血压患者的血压控制及用药依从性的影响

目的:探讨基于用药自我效能量表(SEAMS)评估的针对性护理对老年高血压的应用效果。方法:纳入2021年1月至2023年8月于上饶市人民医院门诊收治的65例老年高血压患者,根据抛掷法分为SEAMS组(基于SEAMS评估的针对性护理)33例、常规组(一般护理)32例,干预3个月。比较两组血压控制、用药依从性、自我管理能力、健康状况。结果:SEAMS组干预后血压值较常规组低(P<0.05),SEAMS组血压控制率高于常规组(P<0.05),SEAMS组高血压患者服药依从性自我效能量表(MASES-R)评分、SEAMS评分、高血压病人自我管理量表评分、自测健康评定量表评分较常规组高(P<0.05)。结论:对老年高血压患者行基于SEAMS评估的针对性护理干预可控制血压水平,提升用药依从性、自我管理能力,改善健康状况。

GMAS、MMAS-8和SEAMS评估慢性病病人用药依从性效能的比较

目的:比较普适性药物依从性量表(GMAS)、Morisky服药依从性测量量表(MMAS-8)、合理用药自我效能量表(SEAMS)在慢性病病人中的应用效果,为临床选择有价值的慢性病用药依从性评估工具提供参考。方法:于2021年10月—2022年2月选取在天津市3所医疗机构就诊的270例成年慢性病病人为研究对象,采用一般资料调查表、GMAS、MMAS-8、SEAMS进行用药依从性评估,并以MAQ作为效度评价标准,采用受试者工作特征(ROC)曲线、Bayes判别分析、Kappa一致性检验和阳性似然比对3种慢性病用药依从性评估工具进行比较。结果:以MAQ为评价标准,270例病人中用药依从性差者122例(45.2%)。GMAS、MMAS-8、SEAMS评分的ROC曲线下面积(AUC)分别为0.981,0.984,0.917,灵敏度分别为0.987,0.993,0.676,特异度分别为0.926,0.943,0.951,约登指数分别为0.913,0.936,0.627(P<0.001)。GMAS、MMAS-8和SEAMS对评估慢性病病人用药依从性的交叉检验准确率分别为89.6%、97.0%和80.7%,与MAQ评估结果的一致性检验Kappa值分别为0.917,0.940,0.608(P<0.001),阳性似然比分别为13.367,17.303,13.734。结论:3种量表在评估慢性病病人是否存在用药依从性不佳风险时均有较高价值,其中MMAS-8评估慢性病病人用药依从性的效能最高,GMAS量表次之,最后是SEAMS,提示研究人员可根据研究对象个性化特点和研究目的针对性地选择评估工具,有助于准确识别用药依从性不佳的慢性病病人并早期开展干预。

Movement and deformation characteristics of overlying rock mass in deep coal seam

The 110 mining method is an innovative and useful coal mining technology.It mainly relies on two technologies to improve coal mining rate:Top cutting and pressure relief,Negative Poisson’s ratio anchor cable(NPR anchor cable)support.This study develops a large-scale physical model test using the speckle monitoring system(DIC),the stress-strain monitoring system,and the infrared thermal imaging system to deeply investigate the roadway deformation and failure law of the 110 mining method,the displacement movement mechanism of the overlying rock mass,and the change law of rock pressure.Results showed that pillarless coal mining utilizing mine pressure and rock fragmentation and expansion characteristics,the use of cut top pressure relief and NPR anchor stress compensation technology in the kilometer level of deep underground coal mining still has a positive effect along the tunnel space.In addition,they can reduce surface subsidence,provide a scientific basis for ecological protection,and develop other kilometer-level deep soft rock high-ground stress underground projects.

Correction to:Application of long-reach directional drilling boreholes for gas drainage of adjacent seams in coal mines with severe geological conditions

Correction:International Journal of Coal Science&Technology(2022)9:88 https:/doi.org/10.1007/s40789-022-00553-6 In this article,the author would like to change the Ethics Declaration as below:EthicsDeclarations Scientific work published within the framework of an international project DD-MET co-financed by the Research Fund for Coal and Steel(RFCS),(Grant Agreement:847338)and by the Polish Ministry of Science and Higher Education(Contract no.5073/FBWiS/19/2020/2 and 5038/FBWiS/2019/2).

Parametric study on the ballistic performance of seamed woven fabrics

The ballistic perforation response of composite fabrics made by combining plain weaves with seaming technology is reported and compared with conventional unseamed plain fabrics.The effect of the seaming technique on the ballistic resistance of aramid plain fabrics is investigated by varying the seaming process.The ballistic experiment uses 8 mm diameter spherical projectiles to impact different fabric sample targets with velocities of 230 m/s and 400 m/s.The ballistic performance of seamed and unseamed fabrics is characterized by the specific energy absorption(SEA)values of the fabrics.The results show that the seamed fabric has a better energy absorption capacity than the unseamed fabric,e.g.,the SEA of sample 5(seaming lines on every four yarns in a single-ply fabric system)is 135%of sample 1(plain weave without thread seaming).In the single-layer system,the effect of the seaming technique on the energy absorption of the fabric in significant when considering seaming density,seaming orientation,seaming distance,and seaming material on the plain fabric;In addition,it is found that in multi-layer systems,seamed panels(e.g.,sample 7)exhibit better ballistic performance than multi-layer fabrics(e.g.,sample 2),and the specific energy absorption of sample 7 is approximately 156%and 200%of sample 6 and sample 2,respectively.Meanwhile,the energy absorption of the fabric decreases with the increase of impact velocity,which is related to the energy absorption mechanism of the soft fabric system at high impact velocities.The yarn pull-out tests shows that the constraint provided by the seaming thread increases the friction between the fabric-forming yarns.However,when the constraint exceeds a certain level,it is detrimental to the energy absorption of the fabric,which may be due to the overconstraint of yarn mobility.

Ground fissure development regularity and formation mechanism of shallow buried coal seam mining with Karst landform in Jiaozi coal mine: a case study

A comprehensive study was undertaken at Jiaozi coal mine to investigate the development regularity of ground fissures in shallow buried coal seam mining with Karst landform,shedding light on the development type,geographical distribution,dynamic development process,and failure mechanism of these ground fissures by employing field monitoring,numerical simulation,and theoretical analysis.The findings demonstrate that ground fissure development has an obvious feature of subregion,and its geographical distribution is significantly affected by topography.Tensile type,open type,and stepped type are three different categories of ground fissure.Ground fissures emerge dynamically as the panel advances,and they typically develop with a distance of less than periodic weighting step distance in advance of panel advancing position.Ground fissures present the dynamic development feature,temporary fissure has the ability of self-healing.The dynamic development process of ground fissure with closed-distance coal seam repeated mining is expounded,and the development scale is a dynamic development stage of“closure→expansion→stabilized”on the basis of the original development scale.From the perspective of topsoil deformation,the computation model considering two points movement vectors towards two directions of the gob and the ground surface is established,the development criterion considering the critical deformation value of topsoil is obtained.The mechanical model of hinged structure of inclined body is proposed to clarify the ground fissure development,and the interaction between slope activity and ground fissure development is expounded.These research results fulfill the gap of ground fissures about development regularity and formation mechanism,and can contribute to ground fissure prevention and treatment with Karst landform.

Geopolymer-based modification of blasting sealing materials and optimization of blasting block size in coal seams of open pit mines

This research proposes the utilization of a geopolymer-based blasting sealing material to improve the profitability of coal sales and reduce the rate of coal fragmentation during blasting in open pit mines.The study first focused on optimizing the strength of the sealant material and reducing curing time.This was achieved by regulating the slag doping and sodium silicate solution modulus.The findings demonstrated that increasing slag content and improving the material resulted in an early rise in strength while increasing the modulus of the sodium silicate solution extended the curing time.The slag doping level was fixed at 80 g,and the sodium silicate solution modulus was set at 1.5.To achieve a strength of 3.12 MPa,the water/gel ratio was set at 0.5.The initial setting time was determined to be 33 min,meeting the required field test duration.Secondly,the strength requirements for field implementation were assessed by simulating the action time and force destruction process of the sealing material during blasting using ANSYS/LS-DYNA software.The results indicated that the modified material meets these requirements.Finally,the Shengli Open Pit Coal Mine served as the site for the field test.It was observed that the hole-sealing material’s hydration reaction created a laminated and flocculated gel inside it.This enhanced the density of the modified material.Additionally,the pregelatinized starch,functioning as an organic binder,filled the gaps between the gels,enhancing the cohesion and bonding coefficient of the material.Upon analyzing the post-blasting shooting effect diagram using the Split-Desktop software,it was determined that the utilization of the modified blast hole plugging material resulted in a decrease in the rate of coal fragmentation from 33.2%to 21.1%.This reduction exhibited a minimal error of 1.63%when compared to the field measurement,thereby providing further confirmation of the exceptional plugging capabilities of the modified material.This study significantly contributes to establishing a solid theoretical basis for enhancing the blasting efficiency of open pit mines and,in turn,enhancing their economic advantages.

In-situ gas contents of a multi-section coal seam in Sydney basin for coal and gas outburst management

The gas content is crucial for evaluating coal and gas outburst potential in underground coal mining. This study focuses on investigating the in-situ coal seam gas content and gas sorption capacity in a representative coal seam with multiple sections (A1, A2, and A3) in the Sydney basin, where the CO_(2) composition exceeds 90%. The fast direct desorption method and associated devices were described in detail and employed to measure the in-situ gas components (Q_(1), Q_(2), and Q_(3)) of the coal seam. The results show that in-situ total gas content (Q_(T)) ranges from 9.48 m^(3)/t for the A2 section to 14.80 m^(3)/t for the A3 section, surpassing the Level 2 outburst threshold limit value, thereby necessitating gas drainage measures. Among the gas components, Q_(2) demonstrates the highest contribution to Q_(T), ranging between 55% and 70%. Furthermore, high-pressure isothermal gas sorption experiments were conducted on coal samples from each seam section to explore their gas sorption capacity. The Langmuir model accurately characterizes CO_(2) sorption behavior, with ft coefcients (R^(2)) greater than 0.99. Strong positive correlations are observed between in-situ gas content and Langmuir volume, as well as between residual gas content (Q_(3)) and sorption hysteresis. Notably, the A3 seam section is proved to have a higher outburst propensity due to its higher Q_(1) and Q_(2) gas contents, lower sorption hysteresis, and reduced coal toughness f value. The insights derived from the study can contribute to the development of efective gas management strategies and enhance the safety and efciency of coal mining operations.

Evaluation of roof cutting by directionally single cracking technique in automatic roadway formation for thick coal seam mining

Automatic roadway formation by roof cutting is a sustainable nonpillar mining method that has the potential to increase coal recovery,reduce roadway excavation and improve mining safety.In this method,roof cutting is the key process for stress relief,which significantly affects the stability of the formed roadway.This paper presents a directionally single cracking(DSC)technique for roof cutting with considerations of rock properties.The mechanism of the DSC technique was investi-gated by explicit finite element analyses.The DSC technique and roof cutting parameters were evaluated by discrete element simulation and field experiment.On this basis,the optimized DSC technique was tested in the field.The results indicate that the DSC technique could effectively control the blast-induced stress distribution and crack propagation in the roof rock,thus,achieve directionally single cracking on the roadway roof.The DsC technique for roof cutting with optimized parameters could effectively reduce the deformation and improve the stability of the formed roadway.Field engineering application verified the feasibility and effectiveness of the evaluated DSC technique for roof cutting.

Automation Technology in Welding Seam Welding Machining Design

With the continuous development of society,the gradual improvement of mechanical automation technology has been introduced into the production of many enterprises in China,which has had a great impact on the increase of China′s gross national product.Applying mechanical automation technology greatly saves labor cost,improves working efficiency and the production level of enterprises,effectively promotes the development of enterprises,and increases the enterprise′s income.In addition,mechanical automation technology is closely related to product production⁃related technology and plays a very important role in the innovation of enterprise products.This article will briefly introduce the design and application of automation technology in welding seam welding design,and understand the development background,research status,current application and simulation design.

煤层瓦斯含量测定技术及装备研究进展

瓦斯含量是煤与瓦斯突出危险预测、煤层瓦斯资源量估算、矿井瓦斯治理工程设计的重要参数。围绕如何在大区域准确快速测定煤层瓦斯含量,依托国家科技重大专项、国家自然科学基金和煤炭企业联合基金等项目科技攻关,在取样、测试方面取得了一定进展。主要表现在如下4个方面:①煤层瓦斯含量测定取样经历了孔口接样、岩心管定点取样、压力引射定点取样和密闭取样4个阶段,密闭取样装备保压能力达到11.5 MPa,煤心直径达到38 mm;②针对不同煤层地质条件,发展形成了顺煤层定向长钻孔密闭取样、底板穿层钻孔密闭取样和顶(底)板梳状定向长钻孔密闭取样3种取样技术;③在河南焦作和山西晋城矿区硬煤层中,顺层定向长钻孔取样深度达到516 m,密闭取样法测得煤层瓦斯含量较常规取样法分别平均提高了0.44倍和1.04倍。在安徽淮南矿区碎软煤层中,穿层钻孔密闭取样深度达到209 m,测得煤层瓦斯含量较常规取样法平均提高了0.26倍;在安徽淮北矿区碎软煤层中,顶(底)板梳状钻孔密闭取样深度达到484 m,测得煤层瓦斯含量较常规取样法平均提高了0.19倍,密闭取样法在煤层瓦斯含量测定精度、探测范围上优于常规取样法;④在瓦斯含量测试方面,除了传统解吸法测试,发展了系列煤矿井下瓦斯含量快速测试装备,可实现最快30 min内测得煤层瓦斯含量,一般用于百米孔内的瓦斯含量测试。提出了煤层瓦斯含量测定密闭取样装备需向小型化、轻量化的方向发展,并能实现随钻密闭取样。在测试上,应根据实际情况确定合理的解吸终止限,并将测试装备和密闭取样装备进一步结合,以实现深孔瓦斯含量快速准确测定。密闭取样技术已成为煤层瓦斯含量大区域精准勘查、预测的主要手段,是煤炭安全高效开采的重要技术保障。

我国大倾角煤层开采技术变革与展望

大倾角煤层是我国煤炭资源的主要赋存样式之一。在地域分布上呈现出广泛性与区域性,据不完全统计,全国25个省、自治区、直辖市均涉及该类煤层开采,在中西部地区储量丰富、产量大、生产集中程度高。在赋存条件上呈现出多样性与复杂性,不同区域成煤时期不一,构造控煤过程迥异,形成了多样且复杂的开采条件,催生了不同的开采技术要求。大倾角煤层开采的技术难度大。煤层倾角导致采场围岩运动破坏呈现非对称性显现特征,支护系统稳定性控制与“三机”配套与协同、采准巷道布置与支护、工作面“人-机”环境安全保障等工作的难度显著加剧,严重制约了矿井安全高效开采。大倾角煤层开采的区域经济需求强,该类煤层赋存与生产较集中的区域多见以煤炭工业为主的资源型城市,经济结构相对单一,煤炭资源安全高效开发利用对区域能源保供、民生保障、经济保稳具有兜底作用。长期以来,大倾角煤层开采技术变革聚焦于解决“难”与“需”的矛盾,在采煤方法与工艺、岩层控制理论与技术、成套装备研制与应用3个方面不断完善、创新、发展,实现了由非机械化向机械化开采的转变,安全产效水平大幅提升,人员劳动强度大幅下降,作业环境显著改善。20世纪90年代中期,川煤集团绿水洞煤矿首次成功实现了大倾角中厚煤层长壁综采,冲破了大倾角煤层机械化开采技术“禁区”。在此示范作用下,大倾角厚煤层长壁综放开采、大采高综采、薄煤层伪俯斜长壁综采三项首创性工程实践先后取得成功。这一过程中创新了工作面非线性限位布置与调斜方式,确立了“支架-围岩”系统稳定性多维交互控制模式,研发了工作面成套装备,取得良好收效,综合机械化开采技术适用范围进一步拓宽。与此同时,大倾角煤层开采仍存在许多亟待突破的关键科学问题与技术瓶颈,导致自动化、智能化水平提升与近水平/缓倾斜煤层相较仍存在较大差距。需进一步强化倾斜层状煤系地层煤岩体采动力学行为研究,揭示其对采场围岩灾变的控制机制,并实现量化表征;需进一步阐明岩体承载结构-采场装备群组系统间的多维动态作用过程与规律,完善装备与围岩多维动态多目标协同控制理论与技术基础,实现技术转化应用。在科学问题取得突破的基础上进行采煤方法、回采工艺、岩层控制、成套装备的系统性技术创新与研发,破解大倾角煤层开采安全-产效双提升的制约技术瓶颈,使大倾角煤层综合机械化开采倾角上限在有可靠技术保障的前提下向上延伸(扩展),为实现自动化、智能化开采奠定基础。

煤炭原位开发地质保障

“双碳”目标下,面对“缺油、少气、相对富煤”的资源禀赋特征,煤炭在一段时期内仍占据中国的主体能源地位,但煤炭的低碳、清洁开发转型势在必行。地下原位热解、气化、干馏、制氢等方式有望成为未来煤炭开发的重要抓手。当前对煤炭原位开发已有较多探索,但地质选址和开发过程的地质安全性、可靠性和环保性仍是制约其规模化和商业化的科学难题。因此,煤炭原位开发地质保障的理论和技术研究亟待深入。秉持“安全、经济、环保、可持续”原则,从煤炭资源禀赋特征和地质条件出发,分析了煤炭原位开发研究现状;基于煤炭开发全生命周期的科学理念,提出了“煤炭原位开发地质保障”的科学内涵;在查明采前地质条件的基础上,从物理机制角度揭示深部原位开发过程中围岩地质体响应特征和损害规律,阐明原位开发中岩体工程地质力学行为,构建原位开发地质条件动态评价模型,形成原位开发减损保障策略和方法,提出原位开发空间的再利用途径,并以煤炭地下气化和地下热解2种开发模式为例阐述了原位开发阶段性,明确了原位开发区设计的地质条件要素,强调开发过程中实时动态监测和评价围岩地质体响应保证开发区密封性与安全性,实现地质条件时空演化的评价及地质风险可控性,此外注重协同开发深部热能与共伴生资源,实现残余资源利用和地下空间再利用。煤炭原位地质保障研究体现了资源赋存条件、地质环境约束、原位开发技术、地质风险防控、资源协同开发等层面的要求,突出了原位扰动条件下的地质条件变化,强调开发扰动与地质体结构的整体研究,理解原位开发时空效应范畴的多相场耦合损伤机制,从多圈层角度揭示原位开发扰动效应下地质风险模式,破解资源开发与地质环境制约之间矛盾,对于推动未来煤炭低碳开发,实现煤炭工业高质量发展具有重要的理论和实践指导意义。

深部煤层地下气化选址研究——以东胜气田J148地区为例

从地质构造、水文地质、煤层气化适用性等角度,系统研究了东胜气田J148地区中生界侏罗系中下统延安组延9煤层地下气化的可行性,并探讨了利用深部煤层气化燃空区孔隙层、含水层及该区致密气层进行碳封存的前景。研究结果表明,该区延9煤层埋深1 264~1 285 m、倾角小于1°,煤层稳定性好。气化目标选区内地层断层、节理裂隙不发育,偶有裂隙但断面新鲜、闭合,煤层气化后空腔有较好的密闭性,对煤炭地下气化影响小,有利于气化炉的建设和扩展,可满足规模化煤炭地下气化项目实施。延9煤层顶底板存在连续的隔水层,能阻截地下水对煤层直接充水,有利于地下气化炉布置;顶板隔水层厚度小于导水裂隙带高度,存在垮落导通顶板含水层间接充水的风险,但顶板含水层属弱富水含水层,涌水量小,风险可控;底板隔水层厚度大于隔水层的安全厚度,能有效阻截煤层底板含水层对煤层直接充水的风险。总体而言,延9煤层厚度适中、夹矸少,属低灰、低硫、高热值不黏煤,煤焦反应活性高,具有良好开发前景。针对深部煤层规模化气化开采产生大量的CO_(2)排放,初步探讨了利用煤层燃空区、顶底板含水层和下部致密天然气层进行CO_(2)安全封存可行性。分析认为,在延9煤层气化燃空区孔隙层和顶底板含水层中,可封存煤层气化产生的CO_(2)的60.8%~88.2%;若结合东胜气田上古生界致密天然气开发,用煤气化产生CO_(2)进行天然气驱替与封存,有望实现深部煤层气化开采过程近零碳排放。

深埋倾斜特厚煤层窄煤柱护巷机理与围岩控制

我国中东部地区采深大、巷道变形和冲击风险大,窄煤柱沿空掘巷技术可改善巷道围岩环境。为掌握窄煤柱护巷机理并形成针对性围岩控制技术体系,以800 m埋深倾斜特厚煤层3 m窄煤柱沿空掘巷为背景,开展了理论分析、现场实测及数值模拟研究,结果表明:①该巷围岩破碎程度及变形煤柱侧比实体煤侧严重,煤柱破碎程度及变形采空区侧比巷道侧大,尽管埋深大,但已稳定采空区承担较大覆岩载荷,高应力已充分向深部岩体分流;②巷道变形非对称,实体煤侧顶板下沉量比煤柱侧大,巷帮以浅部变形为主,煤柱帮上部和实体煤帮中部变形较大;③采空区是掘巷卸荷后主要的形变通道,利于形变能向采空区缓释、降低冲击风险;④卸压区形状由掘巷前三角形扩展为掘巷后平行四边形,掘巷后应力集中区转移至实体煤帮右上方实体煤岩体中;⑤窄煤柱一次和二次剪切破坏的交界面及掘巷右上方实体高应力区为围岩关键控制区,据此提出基于煤柱多重塑性破坏区发育规律的煤柱加固和高应力区精准卸压联合的围岩控制技术体系。研究可为邻近工作面以及其他类似深埋倾斜特厚煤层开采提供理论支撑和科学依据。

倾斜碎软煤层群煤层气协调开发关键技术-以艾维尔沟矿区为例

为了明确与倾斜碎软煤层开采条件相适配的煤与煤层气协调开发关键技术,基于倾斜碎软煤层群瓦斯难抽采与煤层群非对称采动特征,形成了与之匹配的非对称卸压时空协同“三孔四区五量”煤与煤层气协调开发模式,明确了非对称采动下煤与煤层气协调开发策略,阐明了井上下联合煤与煤层气协调开发时空协同机制。针对倾斜碎软突出首采煤层消突困难的问题,优化了倾斜碎软煤层下向长钻孔施工工艺,研制了钻头电磁波无线随钻测量系统,实现了更高精度的钻孔轨迹防偏。针对非对称采动区地面井防护缺乏针对性的难题,阐明了非对称采动覆岩卸压破坏时空演化特征,获得了非对称采动下覆岩采动裂隙演化特征,确定了倾斜煤层地面井井位安全位置,研发了能够兼顾地面井稳定性和抽采效率双因素的采动区地面三开套管结构。应用结果表明:时空协同的“三孔四区五量”模式能够实现煤层气高效抽采,保障倾斜煤层群的抽掘采接替平衡;倾斜煤层下向钻孔递进式抽采方式拓展了递进式抽采的应用范围,破解了倾斜煤层煤层气抽采过程中的时间不协调问题;优化后的采动地面井维稳结构能够适应非对称采动作用,实现了采动区地面井煤层气高效抽采。上述成果在新疆焦煤集团艾维尔沟矿区得到推广应用,初步形成符合艾维尔沟矿区主要高瓦斯矿区倾斜煤层特点的煤层气抽采关键技术和典型模式。

开采保护层与预抽煤层瓦斯防突效果分析

为比较开采保护层与预抽煤层瓦斯防突效果,以1124(3)运顺开采保护层段和预抽煤层瓦斯段煤巷掘进为试验对象,统计了试验地点煤巷掘进期间残余瓦斯含量、钻屑瓦斯解吸指标K1、钻屑量等防突指标,采用假设检验方法推断了各防突指标是否有差别,分析了开采保护层段和预抽煤层瓦斯段各防突指标产生差别的原因,验证了开采保护层区域防突措施比预抽煤层瓦斯区域防突措施更加安全可靠。

大倾角煤层伪俯斜工作面平行四边形液压支架结构设计与运动响应

液压支架是大倾角煤层伪俯斜工作面“围岩-装备”系统稳定性的核心,现有液压支架结构无法适应伪俯斜开采空间稳定性要求,严重影响了该类条件下工作面安全高效开采。以大倾角煤层伪俯斜开采工作面为研究背景,采用工程类比、结构运动学分析、数值仿真的综合研究方法,分析了大倾角伪俯斜工作面“支架-围岩”稳定性特征,并以ZY7000/22/45型液压支架为基础,发明一种新型平行四边形液压支架,进行了结构合理性设计,分析了关键构件运动学响应特征。研究表明:大倾角伪俯斜综采工作面垮落矸石非均匀填充以及矸石对支架的砸、压、推作用是影响支架稳定性的关键因素,平行四边形顶梁与底座更适应伪俯斜工作面。设计的平行四边形支架顶梁、底座及立柱排布方式为平行四边形,异形掩护梁与后连杆、油缸连杆、底座构成柔性四连杆结构。平行四边形支架立柱为主要承载结构,油缸连杆为主要运动机构,其运动特征影响因素主要为上下柱窝间距和前后连杆与掩护梁铰接位置间距,其中掩护梁与后连杆是支架位姿调控的关键,且支架运动过程中无双扭线产生。研究结果为该类条件工作面支架提供了一种选型,一定程度上保障了该类煤层的安全生产。

结合主成分分析和图像分块的重定向研究

针对现有图像重定向方法视觉效果差和处理速度慢的问题,提出一种基于主成分分析法和分块的内容感知图像重定向方法。首先,利用主成分分析法融合梯度图和显著图来提取更加丰富的图像特征,避免主体信息失真;其次,相邻裁缝线由均值代替,避免像素不连贯;最后,根据能量图中列能量值的大小将图像分为显著区域和非显著区域,并行缩放分块,更加注重图像特征并提高运行效率。在MIT RetargetMe、DUT-OMRON和NJU2000数据集上进行实验分析,以主观感受和客观因子运行时间、SIFT-flow作为评价指标,与几种常用算法对比。实验结果表明,该方法保证了图像主体信息的完整性,平均运行时间为线裁剪算法的1/3。本文提出的方法不仅具有较优的视觉效果,而且可降低运算量。