Prediction method for risks of coal and gas outbursts based on spatial chaos theory using gas desorption index of drill cuttings

Based on the evolution of geological dynamics and spatial chaos theory, we proposed the advanced prediction an advanced prediction method of a gas desorption index of drill cuttings to predict coal and gas outbursts. We investigated and verified the prediction method by a spatial series data of a gas desorption index of drill cuttings obtained from the 113112 coal roadway at the Shitai Mine. Our experimental results show that the spatial distribution of the gas desorption index of drill cuttings has some chaotic charac- teristics, which implies that the risk of coal and gas outbursts can be predicted by spatial chaos theory. We also found that a proper amount of sample data needs to be chosen in order to ensure the accuracy and practical maneuverability of prediction. The relative prediction error is small when the prediction pace is chosen carefully. In our experiments, it turned out that the optimum number of sample points is 80 and the optimum prediction pace 30. The corresponding advanced prediction pace basically meets the requirements of engineering applications.

Research on Reliability of Desorption Indexes of Drilling Cuttings(K_(1)andΔh_(2)):A Case-Based on Pingdingshan Mining Region,China

To accurately predict the risk of coal and gas outburst and evaluate the reliability of desorption indexes of drilling cuttings(K_(1) andΔh_(2))in No.16 coal seam of Pingmei No.12 coal mine,two sets of coal samples were selected from the target coal seams for proximate analyses,methane adsorption/desorption tests,and desorption indexes of drilling cuttings tests.The results indicated that the desorption volume in the initial stage of desorption is large,and increases slowly in the later stage.The methane desorption volume of PMD1 and PMD2 coal samples accounts for 15.14%-18.09%and 15.72%-18.17%respectively in the first 1 min,and 43.92%-48.55%and 41.87%-52.25%respectively in the first 10 min in the 120 min desorption tests.Both K_(1) andΔh_(2) present power function relationships with methane pressure.Similarly,the power function relationships also can be found between the initial desorption characteristics(Q1 and Q4-5)and the methane pressure.Finally,the average relative error between the measured value and the calculated value of Q1 based on K_(1) is less than that of Q4-5 based onΔh_(2),which indicates that K_(1) is a more reliable index thanΔh_(2) to predict the risk of coal and gas outburst in the No.16 coal seam of Pingmei No.12 coal mine.

Effects of Fermentation and Drying on the Fermentation Index and Cut Test of Pulp Pre-conditioned Ghanaian Cocoa （Theobroma cacao） Beans

Investigations were conducted to establish effects of fermentation and drying on the fermentation index （FI） and cut test of pulp pre-conditioned Ghanaian cocoa beans using a 4 x 3 full factorial experimental design with the principal factors being pod storage （0, 3, 7 and 10 d） and fermentation time （0, 3 and 6 d） to study the changes occurring during the fermentation process. The study also used a 4 x 3 full factorial design with pod storage （0, 3, 7 and 10 d） and drying time （0, 3 and 7 d） being the principal factors investigated to study the changes occurring during the drying process. FI and cut test of the beans were studied during fermentation as well as the drying process. FI of the beans increased significantly with pod storage and fermentation but decreased slightly during drying. FI of the unfermented beans increased slightly from 0.674 for the unstored pods to 0.763 after 10 days of pod storage. The FI of the fermented beans （six days fermentation） also increased from 1.390 for the unstored pods to 1.424 for pods stored for 10 days. It decreased from 1.389 at the start of drying for the unstored pods to 1.105 for pods stored for 10 days at the end of drying （seven days）. FI of all the beans were however, above 1.0 at the end of fermentation and drying for all pod storage treatments. Cut test revealed that storage of pods for 3, 7 and 10 days increased the percentage of brown beans by 66%, 94% and 72%, respectively, by the sixth day of fermentation. Percentage of brown beans decreased to 61%, 76% and 63%, respectively, for pods stored for 3, 7 and 10 d at the end of drying （seven days）. Cocoa pods can be stored for up to 10 days, fermented for six days and dried for seven days with the necessary formation of brown pigments characteristics of well fermented and dried cocoa beans.

基于投影寻踪模型的特高含水油藏剩余油可采潜力评价方法

影响特高含水油藏剩余油可采潜力的因素极其复杂,且各因素的影响程度差异明显,常规方法多以剩余油饱和度或剩余油储量丰度等单一指标评价剩余油潜力,难以有效指导特高含水油藏剩余油挖潜。在充分考虑特高含水油藏剩余油可采潜力影响因素的基础上,综合表征储层非均质性、剩余油可采储量规模、水淹状况以及油水分流能力的差异,构建了特高含水油藏剩余油可采潜力量化评价指标体系,并考虑不同指标对剩余油可采潜力控制程度的差异,将加速遗传算法与投影寻踪模型相结合来确定各评价指标的客观权重,从而构建了剩余油可采潜力指数,形成特高含水油藏剩余油可采潜力量化评价新方法。以渤海Q油田南区主力产层NmIL砂体为例,开展特高含水油藏剩余油可采潜力量化评价,结果表明,新方法可综合表征不同区域位置的储层物性、可采储量丰度和油水分流能力对剩余油可采潜力的影响,实现了主力产层NmIL砂体剩余油可采潜力分布的差异化定量评价,优势可采潜力区域刻画明显,将其作为NmIL砂体下一步井网加密调整潜力区域,以精准指导加密水平井的部署,为特高含水油藏剩余油挖潜提供了一种全新的分析方法与思路。

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。

不同处理方式对囊托羊蹄甲扦插繁殖的影响

于2022年3月在广西壮族自治区林业科学研究院园林花卉所苗圃,采用L9(33)正交试验设计方法,以枝条形状(A)、根啸生根粉浓度(B)和浸泡时间(C)3个因素,3个水平,研究各因素水平对囊托羊蹄甲扦插繁殖的影响。结果表明:3个因素对生根率、平均根长、抽芽数与新芽长影响的主次水平为A>C>B,对单株主根数量、根系效果指数影响的主次水平为A>B>C,对根粗影响的主次水平为C>B>A,表明除了在根粗指标中因素C占主导因子之外,因素A在其它指标中均占主导因子。细圆柱形插穗的生根率、根系数量、抽芽数、芽高度和根系效果指数等指标显著高于其它枝条形状,其根系效果指数最高(2.53);生根剂10 g·L^(-1)的根系数量、抽芽数、根系效果指数显著高于其它浓度,其根系效果指数最高(2.30);浸泡15 min的各项指标均最高,且显著高于浸泡45 min,其根系效果指数最高(2.08)。综合结果表明,囊托羊蹄甲扦插,采用细圆柱形插穗、根啸生根粉10 g·L^(-1)浸泡15 min为宜。

基于钻屑量界限方程的冲击危险性判定新方法

为提高钻屑法判定冲击危险性的精度,基于钻屑法原理及评价指标,对实际钻屑量数据进行拟合,提出一种基于钻屑量界限方程的冲击危险性判定方法(以下简称“钻屑量界限方程方法”):利用实际钻屑量自回归判定冲击危险性,将钻屑法判定冲击危险性分区细化为冲击危险区、潜在冲击危险区和无冲击危险区。以古城煤矿3208工作面运输巷为工程背景进行了应用,结果表明:钻屑量界限方程方法与现场动力效应及微震监测指标判定结果相符,可有效提高钻屑法判定冲击危险性的精度,减少误判。

盐胁迫对藜蒿扦插枝萌蘖生长及其生理生化特性的影响

以武汉市汉南湘口基地采集的野生种藜蒿和栽培种藜蒿为试验材料,设置NaCl溶液为0、20、40 mmol/L 3个浓度梯度,以无盐胁迫处理的Hoagland营养液作为对照,筛选出藜蒿扦插枝半致死浓度,研究盐胁迫对藜蒿扦插枝萌蘖生长指标和生理指标的影响。结果表明:与对照相比,盐胁迫显著降低栽培种和野生种藜蒿扦插枝的存活率,野生种藜蒿扦插枝的盐胁迫半致死浓度为53.40 mmol/L,栽培种藜蒿扦插枝的盐胁迫半致死浓度为50.99 mmol/L。在盐胁迫处理下,野生种藜蒿扦插枝的株高、根长和侧根数受抑制不显著,并呈现出先升后降的趋势,栽培种扦插枝株高、叶片数、根长和侧根数被显著抑制;野生种藜蒿扦插枝在盐胁迫影响下,CAT、POD、APX、SOD活性均显著提高,MDA与脯氨酸含量呈现先降后升的趋势;而栽培种藜蒿扦插枝随着盐浓度的上升,CAT、POD、APX、SOD的活性显著增强,MDA和脯氨酸含量也显著提高;野生种藜蒿扦插枝抗氧化酶(CAT、POD、SOD)活性均低于栽培种。由此可以推测栽培种藜蒿扦插枝应对盐胁迫伤害更大,野生种藜蒿扦插枝耐盐性更强。

39个传统秋菊品种扦插生根能力综合评价

为了筛选出扦插生根能力较强的传统秋菊(Chrysanthemum morifolium Ramat.)品种,对39个传统秋菊品种扦插12 d的8个根系形态指标进行差异分析、相关性分析和主成分分析,并对这些传统秋菊品种的扦插生根能力进行隶属函数分析和分级。结果显示:供试传统秋菊品种的总根数为3.3~44.0,总根长、平均根长和最长根长分别为2.463~129.174、0.632~4.470和1.610~7.964 cm,根直径为0.200~0.405 mm,根投影面积和根表面积分别为0.102~3.062和0.319~9.619 cm 2,总根体积为0.002~0.079 cm 3,且多数指标以‘火凤凰’(‘Huofenghuang’)最小。这些根系形态指标的变异系数为15.789%~51.605%,其中,总根长的变异系数最大,根直径的变异系数最小,其余指标的变异系数均大于32%。供试传统秋菊品种的多数根系形态指标间存在显著(P<0.05)或极显著(P<0.01)正相关。主成分分析结果显示:前3个主成分的累计贡献率达97.976%。隶属函数分析和分级结果表明:供试传统秋菊品种的扦插生根能力分为优秀、良好、中等和偏差4个等级,‘龙都春丽’(‘Longdu Chunli’)、‘玉楼人醉’(‘Yulou Renzui’)、‘龙都月华’(‘Longdu Yuehua’)、‘圣光华宝’(‘Shengguang Huabao’)、‘龙都秋枫’(‘Longdu Qiufeng’)、‘龙都春晓’(‘Longdu Chunxiao’)的扦插生根能力优秀,综合得分均大于0.70。根投影面积、根表面积和总根体积在不同等级间差异显著。研究结果显示:不同传统秋菊品种间扦插苗的根系形态指标变异较大,其中,‘龙都春丽’等6个品种的扦插生根能力较强,可作为传统秋菊品种遗传改良的亲本。

基于旋分法圆柱齿轮端面倒棱方法研究

基于生产中圆柱齿轮倒棱的高效率和高经济性等需求,结合旋分加工原理和特点,文章提出了一种基于旋分法端面的倒棱方法。首先,结合旋分加工原理,分析旋分倒棱加工运动,建立齿轮和刀具的运动坐标系,并推导坐标系之间的变换关系;其次,根据选定的初始切削刃和建立的坐标变换关系,在齿轮坐标系中构建初始刃扫面;再次,根据刀具设计原理和刃扫面,构建前刀面得到切削刃和构建后刀面,并建立刀具的三维模型;最后,通过多轴数控加工仿真平台开展了齿轮端面旋分倒棱仿真实验。实验结果表明,使用该方法配合所设计的倒棱刀能够实现齿轮端面齿廓高效倒棱需求。

基于高局域化FBG的液相扩散过程监测方法研究

提出了一种利用高局域化光纤布拉格光栅测量液相扩散过程的方法。采用飞秒激光和相位掩模法在载氢的普通单模光纤中成功制备了一种高局域化光纤布拉格光栅,其折射率变化区域在光束入射方向上高度局域在纤芯中,从而在透射光谱中除了具有纤芯模式对应的损耗峰之外,还具有丰富的包层模式对应的损耗峰,纤芯模式和包层模式对应的损耗峰分别达-17.6 dB和-17.2 dB。实验测得光栅截止模式对液体折射率很敏感,截止模式对应的损耗峰中心波长随液体折射率呈线性变化,折射率灵敏度为531.69 nm/RIU,而纤芯模式几乎不随液体折射率发生改变,可用于折射率测量过程中的温度补偿。将高局域化光纤布拉格光栅布设在两种液体的分界面处时,随着液相扩散过程的进行,光纤周围液体的折射率发生变化,通过监测高局域化光纤布拉格光栅透射光谱中截止模式中心波长的变化,实现了对液相扩散过程的原位实时监测。

不同基质和激素处理对常山嫩枝扦插生根的影响

常山是一种优良的观叶、观花、观果的乡土荫生地被和室内观赏植物,兼具药用价值,开发前景好。本文探讨了不同基质种类和激素浓度对常山嫩枝扦插生根的影响,以期获得高效的嫩枝扦插优化方案,指导其商品化生产。采用L 16(42)正交试验设计,研究黄心土、50%珍珠岩+50%泥炭、椰糠和河沙4种不同基质以及4个不同浓度水平(0、500、1000和1500 mg·L^(-1))的K-IBA溶液组合成的16个处理对常山嫩枝扦插生根的影响,分析生根率、平均根长、生根数量、生根指数4个指标。研究结果表明:最有利于扦插生根的是处理8(A 2B 4),即50%珍珠岩+50%泥炭+1500 mg·L^(-1) K-IBA溶液组合,性价比最高的是处理12(A 3B 4),即椰糠+1500 mg·L^(-1) K-IBA溶液组合,二者生根率均达100%,根系发育好,且生根速度比黄心土、河沙快。可见,常山插穗生根是综合生根型,生产上宜用嫩枝扦插大量扩繁;扦插基质适合用混合基质,同时解决生根和生长所需营养;合适的激素浓度有利于插穗生根,以缩短育苗周期。

山西离石断裂南段区域河流地貌指数和阶地下切过程及其构造意义

基于数字高程模型(DEM)、野外河流阶地测量和光释光(OSL)测年,对离石断裂带南段坡度、地形起伏度(RDLS)、面积高程积分(HI)和河道陡峭指数(Ksn)指标进行了提取和分析,对穿过断裂的黄河支流中垛河进行了下切速率的蒙特卡洛模拟。研究结果表明,根据河流地貌指数指示,各河流流域地貌指标均呈低值分布,河流地貌发展总体上处于发育或成熟阶段,离石断裂南段构造活动性较弱。根据中垛河河流阶地和断层的断错关系,结合阶地测年结果认为,该断裂带至少晚更新世晚期以来不活动。利用各级阶地拔河高度和年代数据,中垛河T1—T4年龄分别为(2.08±0.19)ka、(5.63±0.5)ka、(10.22±0.62)ka和(41.22±2.33)ka,42 ka以来中垛河流下切速率线性拟合的结果为0.78 mm/a,全新世以来的下切速率为1.89 mm/a,主要受气候变化影响。

不同方式处理沙地柏母株对扦插生根的影响

以沙地柏为材料,开展在沙地柏母株上四种不同处理下的单因素试验,以黄化、环剥、喷施尿素、喷施NAA处理为试验组,清水处理作对照,分析插穗的生根过程的生根率、腐烂率、平均根数和生根指数,对其生根效果进行多重比较和综合评价。结果表明:利用四种不同的方式处理嫩枝和硬枝插穗,其中生根率和生根指数最高的均为NAA处理方式,分别为84.43%、92.76和76.67%、76.74;综合评价来看,NAA处理方式对扦插生根效果最好,优于其他处理。

钻屑瓦斯解吸指标测定取样装置研究现状

随着我国煤与瓦斯突出预测技术日益完善,煤与瓦斯突出事故得到极大改善,但开采深度增加导致煤层结构日趋复杂,煤与瓦斯突出事故仍时有发生。取样装置是采用钻屑指标法预测煤与瓦斯突出的基础,目前普遍存在因为钻机振动、钻屑飞扬而取样困难的问题,特别是我国煤层逐渐呈现出松软和急倾斜特征。总结了煤矿用钻屑瓦斯解吸指标测定取样装置的研究现状,阐述了其工作特点及未来发展趋势。

乌煤公司锗煤露天矿排土场削坡20°背景下的生态修复评价

为了对锗煤露天矿排土场高陡边坡削坡20°后的生态修复效果进行评价,采用Sentinel-2遥感数据,运用主成分分析法构建了削坡区域RSEI遥感生态指数,研究分析了生态环境质量的演替规律。结果表明:高陡边坡削坡后可实现保水保墒,减少水分蒸发等作用,其生态环境质量明显改善,3~5年基本可实现免维护状态。

基于综合指标法的公路隧道瓦斯有效排放半径考察研究

超前钻孔排放瓦斯作为公路隧道揭煤防突的优选技术措施,依据有效排放半径对超前钻孔进行合理布置,可在保证安全揭煤的前提下,大大优化现场钻孔施工量。采用了综合指标法对待揭煤层有效排放半径进行考察,该方法通过在隧道掘进面布置一组钻孔,对3个反映不同突出主导因素的防突指标(瓦斯含量、K_(1)值、S值)进行测定,分析确定出最优有效排放半径,以此提高测定结果的可靠性与准确性。以四川某隧道8号煤层作为考察研究对象,研究结果表明,该隧道采用直径90 mm的排放钻孔,在排放时间为12 h的条件下有效排放半径为1.6 m。现场运用该方法进行钻孔布置,钻孔施工量减少了56%,安全、高效地完成了揭煤作业。

不同植物生长调节剂对三叶木通扦插生根的影响

为了探究不同植物生长调节剂处理对三叶木通扦插生根的影响,采用正交试验设计L_(9)(3^(4)),以植物生长调节剂种类(ABT1,NAA,GGR6)、质量浓度(50 mg·L^(-1),100 mg·L^(-1),200 mg·L^(-1))、浸泡时间(1 h,2 h,3 h)为试验因素,研究各因素对三叶木通扦插生根的影响。结果表明:植物生长调节剂种类对平均生根数量、平均根长的影响起主导作用,浓度对生根率、根系效果指数的影响起主导作用;对于平均生根数量指标,最优的水平组合是A_(3)B_(3)C_(2)(200 mg·L^(-1)的GGR6浸泡2 h),对平均根长、根系效果指数指标而言,最优水平组合均为A_(1)B_(2)C_(2)(100 mg·L^(-1)的ABT1溶液浸泡2 h),对生根率指标的最优组合为A_(3)B_(2)C_(2)(100 mg·L^(-1)的GGR6浸泡2 h)。经综合评价,三叶木通扦插时植物生长调节剂的最优组合为A_(3)B_(3)C_(2),即以200 mg·L^(-1)的GGR6溶液浸泡2 h为组合,能获得最优的扦插效果。

煤矿综放工作面矿压显现规律与切顶压架预警指标分析

煤矿特厚煤层综放开采时受技术装备等条件限制,放顶煤时由于顶板松散程度较高难以形成稳定结构,导致工作面顶板更容易大面积切落,瞬间冲击支架,损坏液压支架结构,严重影响矿井安全高效生产。以不连沟煤矿F6218综放工作面为工程背景,通过实测数据分析了工作面支架初撑力、安全阀开启情况及工作阻力频率等支架基本工况,揭示了工作面矿压显现规律,建立了适合该矿的切顶压架灾害预警指标体系。结果表明:不连沟煤矿预警指标界限分别为循环增阻率40 kN/min、安全阀开启率50%、动载系数1.4、活柱下缩量500 mm、支架前柱不低于25 MPa,前柱合格率不低于90%;后柱不低于20 MPa,后柱合格率不低于90%。

The Influence Law of Oil Relative Permeability on Water Cut

Water cut is a key evaluation parameter for reservoir development evaluation. Relative permeability curve reflects reservoir characteristics and fluid characteristics. It is important to figure out the influence law of oil relative permeability on water cut. Based on the 269 relative permeability curves of Bohai oilfields, the distribution of oil index of Bohai oilfields were studied. On the basis, combined with Corey expression of relative permeability and fractional flow equation, the theoretical relationship between oil index and water cut increasing rate was established. Three end points of water cut increasing rate curve were proposed and the influence law between three end points and oil index was studied. The results show that the oil index has a linear relationship with three end points. When the value of water oil mobile ratio is large than 1, with the increase of oil index, maximum value of water cut increasing rate gradually increase. When the value of water oil mobile ratio is less than 10, oil index has great effect on recovery percent when water cut increasing rate reaches to the maximum value as well as water cut when water cut increasing rate reaches to the maximum value. The application of SS field shows that the theoretical value is consistent with the field data.