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Stress-unloading and gas migration improvement mechanism in the soft and hard interbedded coal seam using directional hydraulic flushing technology

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International Journal of Mining Science and Technology 2023年第9期33卷 1165-1179页

作者： Hao Zhang Yuanping Cheng Cunbao Deng jingyu jiang Lei Zhang Xiaoyu Yan Junwei Guo Suifang Wang College of Safety&Emergency Management Engineering Taiyuan University of TechnologyTaiyuan 030024China Datong Coal Mine Group Co. LtdDatong 037037China Key Laboratory of Coal Methane and Fire Control Ministry of EducationChina University of Mining and TechnologyXuzhou 221116China National Engineering Research Center for Coal and Gas Control China University of Mining and TechnologyXuzhou 221116China School of Safety Engineering China University of Mining and TechnologyXuzhou 221116China

To enhance gas drainage in the soft and hard interbedded(SHI)coal seam,it’s necessary to unload the insitu stress and improve its gas migration performance.In this research,a directional hydraulic flushing(DHF)technology was carried out.The stress-unloading and gas migration improvement mechanism was analyzed through numerical simulation,and systematic engineering tests were conducted to verify the gas drainage effect.The results show that the improvement of gas migration performance in the SHI coal seam is caused by a combined effect of seepage-improving and diffusion-improving.After DHF,stress-unloading and plastic failure could be achieved both in the soft coal(SC)sublayer and in the hard coal(HC)sublayer.However,the gas diffusion capacity improves significantly in the SC sublayer,while the gas seepage capacity improves notably in the HC sublayer.Meanwhile,the stress-unloading and gas migration improvement effect improves with the flushing radius and the thickness of the SC sublayer.Besides,after adopting the DHF technology,the gas drainage effect improved markedly.The borehole number dropped by 49%,the gas drainage ratio increased from 26.0%to 48.2%,and the average coal roadway excavation speed increased from 2.4 to 5.6 m/d.

关键词： Hydraulic flushing Stress-unloading Plastic failure Permeability-increasing Gas migration

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柔性边界三轴压缩条件下含瓦斯水合物煤体宏细观力学性质

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煤炭学报 2024年第6期49卷 2691-2710页

作者：高霞王楠楠秦程张保勇蒋静宇吴强黑龙江科技大学建筑工程学院黑龙江哈尔滨150022 黑龙江科技大学安全工程学院黑龙江哈尔滨150022 中国矿业大学安全工程学院江苏徐州221116

为探究不同边界条件下围压对含瓦斯水合物煤体的宏细观力学性质影响规律,对饱和度80%的煤样进行围压12、16、20 MPa下双轴离散元试验。首先,考虑颗粒形状效应、水合物胶结作用以及热缩管的影响,选取抗滚动阻力线性模型和平行黏结模型,... 详细信息

为探究不同边界条件下围压对含瓦斯水合物煤体的宏细观力学性质影响规律,对饱和度80%的煤样进行围压12、16、20 MPa下双轴离散元试验。首先,考虑颗粒形状效应、水合物胶结作用以及热缩管的影响,选取抗滚动阻力线性模型和平行黏结模型,分别构建了刚性边界和柔性边界的含瓦斯水合物煤体双轴数值模型。其次,通过与室内试验结果(偏应力−轴向应变曲线、体积应变−轴向应变曲线、内摩擦角、黏聚力以及试样破坏模式)对比,验证了数值模型的可靠性,并发现柔性边界能更好地反映试样轴向应变−偏应力特征、剪胀特性以及强度特性。基于所建数值模型,从试样内部位移场、力学平均配位数、平均孔隙率、接触力链以及水合物黏结破坏角度揭示围压和边界条件对含瓦斯水合物煤体宏细观力学性质的影响规律。结果表明:①随着围压的增大,刚性边界的破坏型式多表现为单斜面剪切破坏;柔性边界的破坏型式由单叉型剪切破坏转变为单斜面剪切破坏。②随着围压的增加,2种边界的力学平均配位数均呈增大趋势,平均孔隙率均呈减少趋势,试样更密实,试样强度增加。③随着围压的增加,颗粒间法向接触力继续增加,试样强度增加,分布在轴向附近的法向接触力随之增大,而在水平向附近的法向接触力变化较小,竖向与水平向法向接触力差异越明显,各向异性更突出;在峰值强度处,随着围压从12 MPa增加到20 MPa,柔性边界法向接触力增加了54.50%,刚性边界法向接触力增加了45.70%。④在不同围压和边界条件下,试样产生张拉和剪切2种不同破坏形式,试样内部起裂主要以水合物和煤间剪切裂纹为主导;随着围压的增大,2种边界内部剪切裂纹数量呈逐渐减小趋势。研究结果从细观尺度上揭示围压对含瓦斯水合物煤体强度变形破坏等宏观力学特性的影响机制。

关键词：煤与瓦斯突出含瓦斯水合物煤体离散元三轴压缩试验围压柔性边界

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急速卸压条件下构造煤体应力释放规律试验研究

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采矿与安全工程学报 2024年第3期41卷 634-644页

作者：蒋静宇史孝宁程远平沈润生马建军王成浩中国矿业大学煤矿瓦斯治理国家工程研究中心江苏徐州221116 中国矿业大学煤矿瓦斯与火灾防治教育部重点实验室江苏徐州221116 中国矿业大学安全工程学院江苏徐州221116 河南神火煤电股份有限公司薛湖煤矿河南永城476600 中山大学土木工程学院广东广州510275

为研究构造煤在急速卸压条件下的应力释放规律,开展了不同卸围压速度条件下的型煤试样三轴试验,对比分析了构造煤在不同应力路径下的应力⁃应变曲线和力学特性演化特征,并通过数据拟合分析了急速卸压条件下的应力释放规律。结果表明:卸... 详细信息

为研究构造煤在急速卸压条件下的应力释放规律,开展了不同卸围压速度条件下的型煤试样三轴试验,对比分析了构造煤在不同应力路径下的应力⁃应变曲线和力学特性演化特征,并通过数据拟合分析了急速卸压条件下的应力释放规律。结果表明:卸围压速度越快,构造煤破坏时的变形程度和峰值应力越小。卸围压降低了煤体的内聚力,劣化程度为14.02%~21.95%,卸围压速度越快,劣化作用越强。卸围压降低了煤体变形模量和泊松比,表明卸围压加剧了煤体损伤,降低了煤体抵抗变形的能力。当卸围压速度趋近于急速时,峰值应力的劣化程度为17.84%,内聚力的劣化程度为21.95%,表明急速卸压条件下构造煤更易失稳破坏,应力释放控制瓦斯膨胀能的非稳态释放,从而导致构造煤突出的连续发展。

关键词：构造煤急速卸压卸围压速度应力释放煤与瓦斯突出

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A Planning Method for Operational Test of UAV Swarm Based on Mission Reliability

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Computer Modeling in Engineering & Sciences 2024年第8期140卷 1889-1918页

作者： jingyu Wang Ping jiang Jianjun Qi College of Systems Engineering National University of Defense TechnologyChangsha410073China Beijing Special Engineering Design Institution Beijing100028China

The unmanned aerial vehicle(UAV)swarm plays an increasingly important role in the modern battlefield,and the UAV swarm operational test is a vital means to validate the combat effectiveness of the UAV swarm.Due to the high cost and long duration of operational tests,it is essential to plan the test in advance.To solve the problem of planning UAV swarm operational test,this study considers the multi-stage feature of a UAV swarm mission,composed of launch,flight and combat stages,and proposes a method to find test plans that can maximize mission reliability.Therefore,a multi-stage mission reliability model for a UAV swarm is proposed to ensure successful implementation of the mission.A multi-objective integer optimization method that considers both mission reliability and cost is then formulated to obtain the optimal test plans.This study first constructs a mission reliability model for the UAV swarm in the combat stage.Then,the launch stage and flight stage are integrated to develop a complete PMS(Phased Mission Systems)reliability model.Finally,the Binary Decision Diagrams(BDD)and Multi Objective Quantum Particle Swarm Optimization(MOQPSO)methods are proposed to solve the model.The optimal plans considering both reliability and cost are obtained.The proposed model supports the planning of UAV swarm operational tests and represents a meaningful exploration of UAV swarm test planning.

关键词： UAV swarm PMS MOQPSO BDD mission reliability operational test planning

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Full sexual maturity-cycle exposure to environmentally relevant concentrations of 17β-estradiol decreases reproductive capacity of zebrafish

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Journal of Environmental Sciences 2024年第3期137卷 580-592页

作者： Yongkang Zhang Yuanjun jiang Qian Sun Meng Li Sheng Chen jingyu Liang Chunsheng Liu College of Fisheries Huazhong Agricultural UniversityWuhan 430070China School of Environmental Studies China University of GeosciencesWuhan 430074China

17β-Estradiol(E2)has been widely detected in natural water and treatment with E2 induces potential endocrine disrupting effects in fish.However,effects on fish fecundity and steroid system after treatment with environmentally relevant concentrations of E2 for the full sexual maturation cycle remain unclear.In this study,zebrafish were treatment with 0,10 or100 ng/L E2 from embryo to adult stage,and effects on gonadal development and differentiation,steroid hormone levels,transcription of genes associated with the hypothalamic-pituitary-gonadal-liver(HPG)axis in adults and fertilization rate of offspring were assessed.The results showed that treatment with E2 lead to increased number of feminization in zebrafish.In females,E2 decreased cumulative amount of spawning and inhibited the maturation of oocyte.In males,E2 inhibited the maturation and motility of sperm,as well as decreased the movement speed of sperm.These adverse effects on sperm might be responsible for the reduced fertilization observed in offspring.In addition,treatment with E2 changed the levels of steroid hormones in zebrafish gonad and altered the transcriptional levels of genes associated with HPG axis,which is responsible for the regulation of germ cells maturation and gonadal development in zebrafish.Overall,these results suggested that treatment with environmentally relevant concentrations of E2 for the full sexual maturity cycle resulted in adverse effects on reproduction in zebrafish.

关键词： Environmental estrogen Zebrafish Fecundity Gonadal development Endocrine disruption

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A nonradical oxidation process initiated by Ti-peroxo complex showed high specificity toward the degradation of tetracycline antibiotics

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Chinese Chemical Letters 2024年第5期35卷 366-370页

作者： Jian Peng Yue jiang Shuangyu Wu Yanran Cheng jingyu Liang Yixin Wang Zhuo Li Sijie Lin College of Environmental Science and Engineering Biomedical Multidisciplinary Innovation Research InstituteShanghai East HospitalTongji UniversityShanghai 200092China Key Laboratory of Yangtze River Water Environment Shanghai Institute of Pollution Control and Ecological SecurityTongji UniversityShanghai 200092China

Nonradical oxidation has received wide attention in advanced oxidation processes for environmental remediation.Understanding the relationship between material characteristics and their ability to initiate nonradical oxidation processes is the key to better material design and performance.Herein,a novel titanium-based metal-organic framework MIL-125-Ti/H_(2)O_(2) system was established to show a highly selective degradation efficacy toward tetracycline antibiotics.MIL-125-Ti with the abundance of TiO6 octahedra units was found to effectively activate H_(2)O_(2) under dark conditions by forming an oxidative Ti-peroxo complex.The presence of the Ti-peroxo complex,confirmed by UV-visible spectrophotometer,fourier transform infrared spectroscopy,and X-ray photoelectron spectroscopy characterizations,showed superior degradation(>95%removal rate)of oxytetracycline hydrochloride(OTC),doxycycline hydrochloride,chlortetracycline hydrochloride,and tetracycline.Density functional theory calculations were performed to assist the elucidation on the mechanism of H_(2)O_(2) activation and antibiotics degradation.The MIL-125-Ti/H_(2)O_(2) system was highly resistant to halogens and background organics,and could well maintain its original catalytic activity in actual water matrices.It retained the ability to degrade 75%of OTC within ten test cycles.This study provides new insight into the nonradical oxidation process initiated by the unique Ti-peroxo complex of Ti-based MOF.

关键词： Nonradical oxidation Metal-organic frameworks Advanced oxidation process Ti-peroxo complex Antibiotics degradation

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Multiple-dimensioned defect engineering for graphite felt electrode of vanadium redox flow battery

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Carbon Energy 2024年第2期6卷 143-153页

作者： Yingqiao jiang Yinhui Wang Gang Cheng Yuehua Li Lei Dai Jing Zhu Wei Meng jingyu Xi Ling Wang Zhangxing He School of Chemical Engineering North China University of Science and TechnologyTangshanChina Tsinghua Shenzhen International Graduate School Institute of Materials ResearchTsinghua UniversityShenzhenChina

The scarcity of wettability,insufficient active sites,and low surface area of graphite felt(GF)have long been suppressing the performance of vanadium redox flow batteries(VRFBs).Herein,an ultra-homogeneous multipledimensioned defect,including nano-scale etching and atomic-scale N,O codoping,was used to modify GF by the molten salt system.NH_(4)Cl and KClO_(3) were added simultaneously to the system to obtain porous N/O co-doped electrode(GF/ON),where KClO_(3) was used to ultra-homogeneously etch,and O-functionalize electrode,and NH4Cl was used as N dopant,respectively.GF/ON presents better electrochemical catalysis for VO_(2)+/VO_(2)+ and V3+/V2+ reactions than only O-functionalized electrodes(GF/O)and GF.The enhanced electrochemical properties are attributed to an increase in active sites,surface area,and wettability,as well as the synergistic effect of N and O,which is also supported by the density functional theory calculations.Further,the cell using GF/ON shows higher discharge capacity,energy efficiency,and stability for cycling performance than the pristine cell at 140 mA cm^(−2) for 200 cycles.Moreover,the energy efficiency of the modified cell is increased by 9.7% from 55.2% for the pristine cell at 260 mA cm^(−2).Such an ultra-homogeneous etching with N and O co-doping through“boiling”molten salt medium provides an effective and practical application potential way to prepare superior electrodes for VRFB.

关键词： graphite felt molten salt N O co-doping ultra-homogeneous etching vanadium redox flow battery

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Effect of magma intrusion on the occurrence of coal gas in the Wolonghu coalfield

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Mining Science and Technology 2011年第5期21卷 737-741页

作者： jiang jingyu Cheng Yuanping Wang Lei An Fenghua jiang Haina National Engineering Research Center for Coal ＆ Gas Control China University of Mining ＆ Technology Xuzhou 221008 China

Chemical analysis, methane isothermal adsorption studies, and mercury porosimetry were performed on ten samples taken from the magma intrusion boundary in the Wolonghu coalfield. The physico-chemical properties of coals from the magma intrusion region are compared to those from the normal regions. The results show that the volatile content (Vad), the limiting adsorption constant (a), and the initial methane diffusion rate of samples from the magma intrusion region are generally smaller than those values from samples from the normal region. The number three coal sample from the magma intrusion region has a large vitrinite reflectance, well developed macropores, a small surface area, and weak methane adsorp- tion capacity. The number ten coal sample from the normal region has a small vitrinite reflectance, well developed micropores, a large surface area, and a strong methane adsorption capacity. The maceral of the coal samples from the magma intrusion region and the normal region are similar. The coal in the area near the magma intrusion boundary is rich in methane and is an area where coal and gas outbursts often occur.

关键词：岩浆侵入区卧龙湖煤田煤气物理化学性质煤与瓦斯突出吸附能力比表面积

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高等级病原微生物实验室在生物医药领域的应用研究

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中国药事 2024年第3期38卷 298-306页

作者：代航刘莎叶强陈晨黄洋王劲松姜晶钰牛群史宇辰徐潇陈国庆中国食品药品检定研究院北京102629 首都医科大学基础医学院北京100069 中国医学科学院医学生物学研究所昆明650118

目的:介绍烈性传染病病原体的诊断试剂、疫苗、治疗药物的研发和评价基本情况,突出高等级病原微生物实验室作为科技支撑和产业成果转化的重要作用,阐释高等级病原微生物实验室在生物医药领域的广阔应用前景。方法:分析国内外应对烈性传... 详细信息

目的:介绍烈性传染病病原体的诊断试剂、疫苗、治疗药物的研发和评价基本情况,突出高等级病原微生物实验室作为科技支撑和产业成果转化的重要作用,阐释高等级病原微生物实验室在生物医药领域的广阔应用前景。方法:分析国内外应对烈性传染病流行的重要措施,梳理高等级病原微生物实验室在诊断试剂、疫苗、治疗药物的研发和评价中发挥的重要作用,阐明提前布局医药产业发展、强化高等级实验室能力建设的方法。结果与结论:应充分发挥高等级病原微生物实验室在生物医药领域的基础设施作用,提前布局我国新发突发传染病病原体的检测鉴定、预防控制、药物治疗的前瞻性技术储备。这是应对SARS、MERS、EBHF、COVID-19等高致病性新发突发传染病引发的全球重大公共卫生问题的重要保障,也是有效防范化解生物安全风险,筑牢国家安全的重要举措。高等级病原微生物实验室在生物医药领域具有广阔的应用前景。

关键词：高等级病原微生物实验室传染病体外诊断试剂疫苗治疗药物

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长江经济带乡村振兴时空演变特征及影响因素分析

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统计与决策 2023年第5期39卷 44-49页

作者：黄敦平蒋静宇安徽财经大学、经济学院安徽蚌埠233030

文章从产业兴旺、生态宜居、乡风文明、治理有效、生活富裕5个维度构建指标体系评价2011—2019年长江经济带乡村振兴发展水平,分析其时空演变规律,并进一步分析影响长江经济带乡村振兴发展水平的因素。研究结果表明:2011—2019年长江经... 详细信息

文章从产业兴旺、生态宜居、乡风文明、治理有效、生活富裕5个维度构建指标体系评价2011—2019年长江经济带乡村振兴发展水平,分析其时空演变规律,并进一步分析影响长江经济带乡村振兴发展水平的因素。研究结果表明:2011—2019年长江经济带乡村振兴发展水平呈现稳步上升态势,并且存在指标维度与空间维度上的双重异质性。首先,长江经济带生态宜居与产业兴旺得分相对较高,乡风文明与生活富裕得分紧随其后,而治理有效得分相对较低;其次,长江经济带乡村振兴发展水平在空间上呈现“东—中—西”梯度递减的分布格局,即长江经济带东部地区乡村振兴发展水平相对较高、中部地区次之、西部地区相对较低;最后,农业现代化水平、农村固定资产投资水平、农村教育水平与财政支农水平是影响长江经济带乡村振兴发展水平的主要因素。

关键词：长江经济带乡村振兴时空分异

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