Surrounding rock control of gob-side entry driving with narrow coal pillar and roadway side sealing technology in Yangliu Coal Mine

Gob-side entry driving can increase coal recovery ratio, and it is implied in many coal mines. Based on geological condition of 10416 working face tailentry in Yangliu Coal Mine, the surrounding rock deformation characteristics of gob-side entry driving with narrow coal pillar is analysed, reasonable size of coal pillar and reasonable roadway excavation time after mining are achieved. Surrounding rock control technology and effective roadway side sealing technology are proposed and are taken into field practice. The results showed that a safer and more efficient mining of working face can be achieved. In addition, results of this paper also have important theoretical significance and valuable reference for surrounding rock control technology of gob-side entry driving with narrow coal pillar under special geological condition.

Research Progress of On-line Monitoring Technology for Electromagnetic Environment of Power Transmission and Transformation Projects

Based on the collection of relevant literature and cases,the research and application status of on-line monitoring technology for electromagnetic environment of power transmission and transformation projects at home and abroad were introduced.Moreover,the problems existing in the on-line monitoring of electromagnetic environment were expounded,and the development prospect was forecasted.

Effect of Ilizarov external fixation combined with negative pressure sealing drainage and antibiotics in the treatment of infective tibial nonunion

Objective:Observation on the effect of Ilizarov external fixation combined with vacuum pressure sealing drainage and antibiotics in the treatment of infective tibial nonunion.Methods:79 patients with tibial infective nonunion who were treated in our hospital from August 2016 to August 2018 were divided into two groups according to random number table,with 39 patients in the control group treated with Ilizarov external fixation technology and 40 patients in the study group treated with vacuum pressure sealing drainage and antibiotics on the basis of the control group.Bone healing time and daily walking were recorded.Rasmussen score,serum intercellular adhesion molecule-1(ICAM-1)and IL-6 levels,lower limb Fugl-Meyer motor function score and lower limb BI index score were compared at different time.Results:The daily walking condition of the study group was significantly better than that of the control group(P<0.05),and the healing time of bone was significantly shorter than that of the control group(P<0.05);the Rasmussen score of the study group was higher than that of the control group at 1 month,6 months and 12 months after treatment(P<0.05);the levels of serum ICAM-1 and IL-6 in the two groups after treatment were lower than those before treatment(P<0.05),and the levels of serum ICAM-1 and IL-6 in the study group were lower than those in the control group after treatment(P<0.05).The lower limb Fugl-Meyer motor function score and lower limb BI index score of the two groups after treatment were higher than those before treatment(P<0.05),and the lower limb Fugl-Meyer motor function score and lower limb BI index score of the study group after treatment were higher than those of the control group(P<0.05).Conclusions:Ilizarov external fixation combined with vacuum pressure sealing drainage and antibiotics can promote the bone healing of patients with infective tibial nonunion,significantly improving their daily walking condition,alleviating inflammation,and recovering the knee joint function and lower limb function well.

Cold welding sealing of copper-water micro heat pipe ends

The quality of micro heat pipe(MHP) is strongly affected by sealing technology. Based on the analysis of requirements of sealing technology, a cold welding technology was presented to seal MHP. In the cold welding process, compression force was used to flatten micro groove copper(MGC) tube. Then the bonding of MGC tube was reached because of intensively plastic deformation of MGC tube under pressure. It is found that the plastic deformation area of the cold welding of MGC tube can be divided into three sections. The deformation of micro grooves in each section was investigated; the influence of the dimensions of cylindrical heads on the weld joint shape and strength was studied; and a comparison between smooth copper tube and MGC tube was done. The results show that a groove compression stage exists in the cold welding of MGC tube besides a flattened stage and a melting stage.

On the installation of an in situ large-scale vertical SEALing (VSEAL) experiment on bentonite pellet-powder mixture

Recently,the Institute for Radiological protection and Nuclear Safety(IRSN)has launched VSEAL(Vertical SEALing)project to investigate the impact of gas migration on the long-term performance of bentonite based vertical sealing systems(VSS).The first VSEAL in situ test was emplaced in IRSN’s Underground Research Laboratory(URL)in Tournemire(France)in 2019 and was equipped with 76 wired and wireless sensors.The test is still in progress,but the collected set of data provides already valuable information of the hydro-mechanical behavior of VSS during hydration.The swelling core consists of a mixture of highdensity pellets and powder of MX80 bentonite in a ratio of 80/20(in dry mass).An innovative method was adopted to drill a 1-m diameter and w10-m deep shaft in order to minimize the rock perturbation at the sidewalls.Because a specific protocol was adopted to install the bentonite mixture together with a careful characterization of the core during construction,VSEAL 1 constitutes the unique in situ sealing test with a well-known initial structural distribution of the pellets and the powder.Some heterogeneities occurred within the experiment during the installation process:a damaged zone developed around the shaft walls due to the interruption of the installation operations caused by COVID19 lockdown in France;a technological gap with a variable thickness between the last pellets layer and the top confining lid and a heterogeneous distribution of the bentonite powder at some layers inducing large inter pellets voids close to the bentonite-rock interface.Artificially injected water volume,relative humidity,water content and swelling pressure in both radial and axial directions were monitored.Comparison of the results showed that the presence of installation-induced heterogeneities led to the generation of preferential flow paths that influenced the swelling pressure evolution at radial and axial directions.

Gasket-Seal技术在颅底肿瘤内镜手术颅底重建中应用的荟萃分析

目的评价Gasket-Seal技术在颅底肿瘤内镜手术颅底重建中应用的效果。方法在中外文文献数据库中检索2007年10月至2016年10月已发表的关于应用Gasket-Seal技术进行颅底肿瘤内镜手术颅底重建的病例对照研究。利用Review Manager(5.3版)软件进行荟萃分析。结果按文献入选标准共纳入5篇病例对照研究,共210例颅底肿瘤内镜手术患者纳入荟萃研究。荟萃分析表明,与非GS组相比,GS组患者术后远期脑脊液漏发生率低(OR=0.32,95%CI=0.11~0.89,P=0.03),术后脑膜炎发生率低(OR=0.10,95%CI=0.01~0.67,P=0.02)。根据GS组是否联合NSF进行亚组分析,结果表明两亚组术后远期脑脊液漏发生率间比较,差异无统计学意义(P=0.85)。在GS组中,采用人工骨组与采用同种骨(包括自体骨和异体骨)组病例术后脑脊液漏发生率比较,差异无统计学意义(P=0.25)。结论应用Gasket-Seal技术能安全有效地完成颅底肿瘤内镜手术中的颅底重建。相较其他颅底重建方法,术后脑脊液漏及脑膜炎的发生率更低。

Review on recent progress in on-line monitoring technology for atmospheric pollution source emissions in China

Emissions from mobile sources and stationary sources contribute to atmospheric pollution in China,and its components,which include ultrafine particles(UFPs),volatile organic compounds(VOCs),and other reactive gases,such as NH3and NOx,are the most harmful to human health.China has released various regulations and standards to address pollution from mobile and stationary sources.Thus,it is urgent to develop online monitoring technology for atmospheric pollution source emissions.This study provides an overview of the main progress in mobile and stationary source monitoring technology in China and describes the comprehensive application of some typical instruments in vital areas in recent years.These instruments have been applied to monitor emissions from motor vehicles,ships,airports,the chemical industry,and electric power generation.Not only has the level of atmospheric environment monitoring technology and equipment been improving,but relevant regulations and standards have also been constantly updated.Meanwhile,the developed instruments can provide scientific assistance for the successful implementation of regulations.According to the potential problem areas in atmospheric pollution in China,some research hotspots and future trends of atmospheric online monitoring technology are summarized.Furthermore,more advanced atmospheric online monitoring technology will contribute to a comprehensive understanding of atmospheric pollution and improve environmental monitoring capacity.

Seal技术轮胎内部亮层薄膜的定性分析

直径不大于5 mm的尖锐异物刺入Seal技术轮胎胎面时,会被胎体层上的特殊密封胶料包裹住。特殊密封胶料具有粘性,喷涂在透明光亮的专用保护薄膜上。亮层薄膜能够对Seal技术轮胎特殊密封胶料起保护和防粘作用,并使成型贴合容易操作。傅里叶红外光谱分析表明,亮层薄膜材质为聚己内酰胺。

STAR-SEAL Supreme技术及其在高速公路上桥面预防性养护中的应用研究

主要以STAR-SEALSupreme为研究对象,通过对该材料技术的介绍,简述了其在沪渝高速公路上桥面预防性养护中的应用方法,研究结果发现,其可以有效改善高速公路桥面的质量,提高公路的防渗水性能,且可有利于高速公路的可持续性使用,应当被广泛应用于高速公路的预防性养护中。

航天器密封舱水分含量测量与除水工艺方法研究

航天器密封舱在进行真空热试验时处在真空容器内部,常规的水分含量测量和除水方法均无法满足密封舱除水要求。本文针对航天器密封舱在真空热试验时的除水难题,设计了一套适合密封舱内水分含量测量的装置,经过标定确保其满足真空环境下水蒸气含量的测量要求。设计的密封舱除水系统通过双向密封法兰与密封舱连接,可以在真空容器外完成对密封舱的除水。试验验证结果表明,该除水方法能够保证在真空热试验过程中密封舱内气体的露点温度低于0℃。

铀矿实物地质资料保护技术探究——以铀矿岩心保护为例

岩心是铀矿资源勘查和开发中重要的数据来源,其对于研究矿床成因、预测矿床分布、评价矿产资源量和开采等具有重要意义。文章深入探究了岩心的保护技术,分析了目前常见的保护方法——石蜡封护法、树脂浇筑法以及真空包覆法的优缺点及对铀矿岩心的适用性。研究结果表明,石蜡封护法、树脂浇筑法和真空包覆法均可用于铀矿岩心保护,应根据实际需要选择最适合的方法,真空包覆法在铀矿实物地质资料保护中的实用性更强,应加强这一方法的应用研究。

富油煤煤质特征与原位热解技术开发利用现状

富油煤是保障我国油气资源供给的重要战略资源,充分利用富油煤的油气属性可拓展煤炭的利用方式,有助于减少煤炭直接燃烧利用所带来的环境问题,尤其通过富油煤原位热解技术还可以促进深部煤炭资源的有效利用。以我国富油煤分布特点为基础,分析富油煤的煤岩组成、煤质特征及其对焦油产率的影响,并总结富油煤原位热解技术的开发利用现状。由现有勘探实践表明,我国富油煤资源丰富,其形成和分布受控于构造演化、古气候、沉积环境以及成煤物质来源等因素;大量的测试分析显示,富油煤的焦油产率与煤成因类型、变质程度、煤岩组成、煤质特征有关;富油煤原位热解开发利用是煤炭清洁高效利用的重要途径之一,针对油页岩等其他地质资源开发利用的技术对富油煤适用性有限。为实现富油煤中潜在“油-气”资源的低碳化开发利用,仍需在富油煤资源精细勘查与评价技术、富油煤原位加热与地下体系封闭技术、富油煤中低温热解与热解油气高效抽采技术以及全工艺流程的施工、监测与评估技术等方面加强研究。

负压封闭引流技术在Ⅲ级暴露犬咬伤创面处理中的应用

目的 探讨负压封闭引流技术(VSD)在Ⅲ级暴露犬咬伤创面的治疗效果。方法 选取2020年1月至2023年12月在郑州大学第五附属医院接受治疗的90例Ⅲ级暴露犬咬伤创面患者,以随机数字表法分为研究组(n=45)与对照组(n=45),研究组采用常规清创结合VSD治疗,对照组采用常规清创、换药治疗,对两组临床相关指标、疼痛程度、各时间段C反应蛋白(CRP)、并发症发生率进行比较。结果 研究组换药次数较对照组少,二期缝合、肿胀消退、创面愈合及住院时间短,差异有统计学意义(P <0.05);研究组换药时疼痛评分较对照组低,差异有统计学意义(P <0.05);两组治疗前、治疗后1 d CRP水平比较差异无统计学意义(P> 0.05),治疗后2 d两组CRP水平均达到最高值,治疗后2~5 d研究组CRP水平低于对照组,差异有统计学意义(P <0.05);随访6个月,研究组并发症发生率(8.89%)低于对照组(24.44%),差异有统计学意义(P <0.05)。结论 Ⅲ级暴露犬咬伤创面应用常规清创结合VSD进行治疗,能够缩短创面愈合时间,减轻患者疼痛,降低创面感染等并发症发生率。

基于传感器技术和水封效应协同的VOCs废气处理系统火灾监测及阻隔装置设计

为了预防和控制有机废气处理设施在运行过程中发生火灾事故,研究设计并制作了一种基于传感器技术和水封效应协同的VOCs废气处理系统火灾监测及阻隔装置。通过多种类型的传感器实时监测关键设备状态参数,早期发现火灾隐患,利用水喷淋阻火装置有效切断火焰在VOCs废气处理系统各区域及生产车间之间的传播路径,依靠逻辑控制程序实现各设备之间的安全联锁,保障VOCs废气处理系统的稳定运行,对当前企业废气处理设施的安全生产研究与探索具有一定的现实价值和意义。

黄茶闷黄工艺影响因子及品质评价技术研究进展

黄茶是我国主要的消费茶类之一。黄茶加工步骤为萎凋、闷黄和干燥,其中闷黄是黄茶品质特征形成的关键环节,快速准确对黄茶闷黄度作出判别,对于黄茶加工至关重要。黄茶闷黄工艺影响因子及品质评价技术研究是认识影响因子、品质评价技术与闷黄质量关系的前提。然而,黄茶闷黄体系受自身复杂性和不可直接测定性的限制,目前闷黄品质评价技术普遍存在精确度低、重复性差和操作复杂等问题。综述已有文献表明,温度、含水率、时间及闷黄过程中微生物等环境因素均会影响黄茶品质特征化合物的形成,从而影响其品质。目前常用的品质评价技术主要包括人工感官、成分检测及智能仿生技术。人工感官易受主观因素影响;成分检测专业性强、操作难度大、前处理复杂;智能仿生技术具有简单、快速、无损等特点,可检测黄茶闷黄适度快速高效评价。通过回顾近年来针对黄茶闷黄影响因子及3种主要评价技术研究进展,重点关注闷黄影响因子与黄茶品质成分之间的关联性及智能仿生技术的发展趋势,以期为黄茶标准化和数字化加工提供支持。

压电陶瓷可控机械密封多场耦合模型与调控性能分析

提出一种基于压电陶瓷的可控机械密封结构,基于有限元软件分析施加电压和压电陶瓷数量对密封静环端面的变形规律;考虑密封动静环与润滑液膜间的热力耦合作用,建立可控机械密封的流固热耦合模型,研究施加电压和压电陶瓷数量对密封调控性能的影响。结果表明:施加电压的压电陶瓷使静环端面产生了径向锥度和周向波度变形,变形量随电压的增大而增加;静环端面变形在增大液膜承载力的同时减小了端面接触力;压电陶瓷数量的增多减小了周向波度变形,增大了径向锥度变形,使静环端面变形趋于周向均匀化;增大压电陶瓷电压可实现密封端面润滑状态的转变,使密封端面摩擦温升降低,使泄漏率控制在允许范围之内。

定向深孔探放水技术在平煤五矿的应用

为了解决平煤五矿上层煤采空区积水威胁到下层煤开采的问题,对当前采空区积水空间位置及积水量进行分析,从经济性、合理性以及时间效应三个方面对三种排水方案进行比选,分析了定向深孔探放水技术相较于常规钻孔探放水技术具有的优势,最终确定定向深孔探放水技术为最优方案。基于此,研究了定向深孔探放水技术的设计方案及施工工艺,并进行现场应用试验,同时采用了固安特封孔技术,与传统水泥浆封孔技术相比缩短了88%的封孔时间,累计排放采空区积水量近30000 m^(3),解决了己_(15)-32020采空区水害问题,掩护了巷道安全掘进。

富油煤原位热解技术研究现状及进展

我国富油煤资源量丰富,原位热解提取油气不仅可以实现富油煤的高效清洁低碳利用,还可以缓解油气对外依存度,是未来富油煤开采利用的重要发展方向之一。简述了富油煤的热物理性质及分布特性,地面热解和原位热解的工艺特点,重点阐述了富油煤原位热解(布井方式、加热方式、原位气化热解一体化、余热利用、储层压裂、地下封闭技术)的研究现状及进展,最后对富油煤原位热解技术的发展方向进行了展望。①梯级利用是富油煤地面热解的重要途径,井工式原位热解可实现井下收油,但需解决长距离输运管道保温问题,钻孔式原位热解是通过高温介质或电加热进行热解,可采用矿区的分布式能源加热载热流体。②推荐采用对流加热为主,其他加热方式为辅的复合加热技术,可利用原位热解后的余热预热载热流体,也可将煤层局部氧化反应的热量用于富油煤原位热解过程,降低载热流体的注热能耗。③原位气化热解一体化技术可有效提高热能利用率,但气化空腔需进行填充。④综合考虑储层压裂和富油煤原位热解孔隙变化规律,控制煤层裂缝生成路径,形成裂缝网络,以增强煤层热传导效率,降低油气产物在煤层中的运移难度。⑤根据富油煤热解工艺特点,选择适宜的地下体系封闭技术,可促进富油煤原位热解过程中能量的高效利用及生态环境保护,其中CO_(2)气驱止水技术在实现地下体系封闭的同时,还可以进行油气驱替并实现CO_(2)的地质封存。

高超声速飞行器的动态热密封技术研究进展

高马赫数飞行带来的气动热一直是制约飞行器向更大速域和空域发展的最大因素,特别是针对飞行器发动机尾喷管和机体之间、飞行器尾翼控制舵等有较大动态间隙部位,对其进行动态热密封的技术难度也远高于一般的机身表面防热;因此,动态热密封技术成为各国在新型高超声速空天飞行器发展中需要突破的重要瓶颈。本文以X-38等飞行器为例,对国外动态热密封技术进行了简要介绍,并对其主要技术类型和关键性能测试方法进行综述,最后对动态热密封技术的发展进行了总结和展望。

配合相对误差对挤压式微流道密封技术的影响规律

由于检测通量的不断提高,微流控芯片包含的检测腔室数量多、间距小、与之连通的流道结构尺寸在微米尺度,这对密封过程的操作精度提出了严苛的要求。探究了外部挤压刀具与微流道位置存在配合相对误差时微流道的塑性变形情况,分析了微流道密封失效的原因,总结了相邻检测腔室内反应液互串的发生规律。统计数据揭示了配合相对误差对密封效果的影响,发现芯片主体和支撑板在宽度方向的配合相对误差对密封成功与否起主导作用,而长度方向的配合相对误差对密封效果影响起次要作用。当宽度方向配合相对误差小于17.7%时,芯片密封成功率为100%;当宽度方向配合相对误差为17.7%~23.5%时,长度方向配合相对误差大于34.2%将导致密封的失效。基于以上结果,对芯片制作和密封过程进行优化,使得宽度方向配合相对误差主要集中在6.8%~8.1%,最大值不超过14.9%。制备并密封后的高通量微流控芯片经温度循环密封测试验证,密封效果优异,所有的检测腔室均未发生泄漏。揭示了影响挤压式微流道密封技术的主要因素,为阵列式微流控芯片的设计与制作提供了参考。