Topsoil and fertilizer effects on ground cover growth on calcareous minesoils

ABSTRACT

We measured canopy cover and aboveground biomass of herbaceous species in four studies for five years (1989–1993) in southeastern Ohio. Three studies compared graded cast overburden, standard graded topsoil (30 era depth), and ripped topsoil. The fourth study lacked the ripped topsoil treatment. In 1997 two studies were seeded with both a standard and a modified mixture of grass and legume species, and two studies used the modified mix only. A nitrogen rate study used 45, 90, or 135 kg/ha of N applied on two occasions, and a phosphorus fertilizer study used rock phosphate amendment at 0, 1120, or 2240 kg/ha and triple superphosphate amendment at 0, 280, or 560 kg/ha. Based on one clipping per year, overall average biomass (Mg/ha dry weight) was slightly greater on standard topsoil (3·34), and ripped topsoil (3·30) than on cast overburden (3·09). Biomass did not differ significantly (p=0·05) on standard topsoil versus cast overburden for 15 of 19 comparisons. Legume biomass (Mg/ha, measured for 3 or 4 years) averaged 0·84 on standard topsoil, 0·75 on ripped topsoil, and 1·16 on cast overburden. In three studies, legume biomass was 50% higher on cast overburden than the topsoils, but differences among the soil surfaces were decreasing by 1993. Nitrogen fertilizer increased ground cover only in the year when fertilizer was applied. Phosphorus fertilizer treatments had no significant effects. Ground cover showed no signs of deterioration during the last measurements in 1993. Observations in 1995 indicated dense canopy cover on all soil surfaces with substantial invasion by goldenrods (Solidago spp.) only on topsoils.     

潮湿煤体压缩破裂过程中红外辐射演化特征研究

为探寻水分对煤体破裂过程表面温度分布的影响,对不同含水率试样进行加载破裂试验,研究其表面红外辐射温度的演化特征,并以平均红外辐射温度AIRT、温度极差R、分形维数D、红外热像特征进行分析研究.结果 表明:干燥、潮湿试样表面平均红外辐射温度总体上均表现为随载荷增加呈下降趋势,但在临近破裂时出现了明显异常:干燥试样表现为升...     

关于黄土湿陷敏感性问题探讨

 黄土特有的结构,决定了黄土具有湿陷敏感性,本文通过土样湿陷敏感性比较试验,对黄土湿陷速率进行分析研究,探讨黄土湿陷敏感性程度的高低,以及黄土湿陷敏感性对地基的不良影响。在依据湿陷系数和湿陷量进行黄土的湿陷性评价时,要考虑黄土湿陷敏感性的特点。     

TL型湿式脱硫除尘器应用与效益分析

早期水平文丘里麻石水膜除尘器由于容易出现裂缝漏和灰尘堵现象,造成脱硫除尘效果差,影响周边环境.采用成熟技术的TL型湿式脱硫除尘设备,其工艺设备布局合理、使用寿命长、操作维护简单、不易结垢堵塞、经济实用、安全稳定、除尘脱硫与锅炉同步运行率达到95％以上、达标排放,产生的经济效益和社会效益显著.     

硅藻土湿法物理提纯工艺研究

针对优质硅藻土资源日益减少的现状,提出一种对资源丰富的中低品位含黏土类杂质的硅藻原土进行提纯的湿法物理分选工艺。分析了硅藻土原矿的化学成分、矿物成分和粒度组成,研究了硅藻颗粒和黏土矿物蒙脱石的表面电位与pH值和分散剂用量之间的关系,确定了硅藻土矿浆最佳的擦洗和分散条件,利用硅藻与黏土矿物之间的粒度差异和表面电位差异,原矿经充分分散后,借助离心力场中硅藻和黏土矿物颗粒之间显著的沉降速度差异,实现高效的分选。实际生产表明,硅藻原土经分选后,SiO2含量由81.78%提高到86.86%,Al2O3含量由5.49%下降到3.45%,Fe2O3含量由2.01%下降到1.42%,达到了一级硅藻土标准。     

钢渣湿法脱硫工艺试验研究

以钢渣作为吸收剂利用自行设计的喷射鼓泡反应器进行烧结烟气脱硫的试验研究,试验研究了钢渣作为新型脱硫剂脱硫效果的分析,针对钢渣粒度、SO2浓度、烟气流量、钢渣浓度等主要参数脱硫效率的影响。试验结果表明:钢渣粒度为0.074 mm、SO_2浓度499.3 ppm、烟气流量5 m3/h、钢渣浆液浓度1.2%时,钢渣的脱硫率在85%以上。因此,钢渣在喷射鼓泡反应器中进行湿法脱硫是可行、有效的。     

喷浆机湿式除尘器防粘技术研究

针对ZCS-7/11型喷浆机上料湿式除尘器水泥粉尘粘结滤网和引射器器壁的问题,采用数值模拟和实验验证的方法,对不同风速条件下除尘器内水泥粉尘的沉积规律进行数值模拟,优选出最佳抽尘风速为1.0 m/s,并通过实验得到了验证。采用增加2个不同方向冲洗喷嘴并在水中添加缓凝剂葡萄糖酸钠解决水泥粉尘粘结问题的方法,实验得出最佳技术参数：每个冲洗喷嘴的喷雾流量为2.5 L/min、葡萄糖酸钠质量分数为1.0%,在此条件下,滤网和引射器入口下侧的水泥粉尘粘结质量分别下降了99.5%、99.3%,且随着时间的推移水泥粉尘粘结质量无明显增大,有效解决了水泥粉尘的粘结问题。     

湿陷性黄土地基的处理与应用

文章主要介绍了有关的湿陷性黄土不同的处理方法,包括:换填法、挤密法、DDC桩、强夯法、重锤夯实法、桩基础、预浸水法和振冲法.并以陕西韩城矿务局采煤综合治理新梅苑小区为例,该工程地基土均为湿陷性黄土,湿陷等级为Ⅱ级～Ⅲ级,部分区域为Ⅳ级,该工程的地基处理方案所取得的效果对同类工程有一定的借鉴.     

Effects of minesoil and seeded herbaceous species on survival of planted trees

ABSTRACT

A series of studies to help find environmentally sound methods to reforest surface-mined lands at reduced cost was established on the Muskingum Mine near Cumberland, Ohio. In one study, three minesoil types (graded topsoil, graded and ripped topsoil, and leveled gray cast overburden) were planted with green ash (Fraxinus pennsylvanica)and white pine (Pinus strobus) trees on subplots seeded with various grass and/or legume mixtures either before tree planting in September or at time of tree planting in March. Also, trees were planted on unseeded subplots. After planting, some trees were oversprayed with Simazine to reduce competition from seeded species. A severe drought that began after planting resulted in heavy mortality but striking survival differences were observed among treatments by end of the growing season.

Green ash survived best (71 percent)on unseeded cast overburden. Survival was significantly lower on graded topsoil (50 percent)and on other minesoils that were seeded the previous September (50–54 percent). The Simazine overspray severely reduced survival of green ash. Among trees that were not sprayed, seeding grasses or grasslegume mixtures in September reduced survival to less than 48 percent compared to 81–94 percent survival on subplots seeded in March or in September with only legumes.

Unlike green ash, white pine trees survived poorly on cast overburden and were not harmed by the Simazine overspray. In fact, few pines survived on seeded subplots unless they were oversprayed. Although Simazine reduced herbaceous competition to pines, survival was about 14 percent higher when grass species were not included in the seeding mixtures. Total mean survival of pine in the study was only 19 percent, with best survival (45 percent)on ripped topsoil.     

超细煤粉表面润湿性的研究

为了研究不同变质程度的煤经超细化处理后表面润湿性的变化，利用德国产的接触角自动测量仪(Operating manual DCAT21)对所制的5种不同变质程度的超细煤粉进行了接触角的测定．测试结果表明，虽然各煤样的变质程度和平均粒径各不相同，但超细化粉碎后，表面润湿性都发生了很大的变化，不同变质程度的超细煤粉表面都变成了强疏水表面．     

基于ABAQUS的湿式多盘制动器温度场数值模拟分析

以井下工程车辆的湿式多盘制动器为研究对象,建立了基于ABAQUS的湿式多盘制动器的热-机耦合有限元分析模型。通过对湿式多盘制动器温度场的数值模拟分析,得到了不同制动工况下湿式多盘制动器各摩擦副的温度变化曲线,为分析湿式多盘制动器的失效形式及原因提供了参考。     

基于高分一号数据的干旱监测方法研究

高分一号数据分辨率高、适用性强、数据获取容易,来源稳定,在较小区域业务化有很大优势。在干旱监测应用方面,使用垂直干旱监测,以德州市为研究区域,利用高分一号数据进行干旱监测研究。垂直干旱指数法适用于裸地,在实际应用时要考虑到植被的影响,对垂直干旱监测法进行了改进,结合实际数据进行多次改进实验,找到适合德州的影响因子计算方法,最终确定适合德州的改进型垂直干旱指数法。研究得出,改进后的垂直干旱指数法精度得到了提高,该方法适用于对德州干旱进行监测。     

基于MODIS-TVDI的山东省干旱监测研究

文中利用MODIS植被指数和地表温度数据构建了温度植被干旱指数(TVDI),对山东省2018年的干旱情况进行监测,并利用气象站观测的温度和降水对结果进行验证评价.研究表明:增强型植被指数(EVI)与地表温度(LST)构建的TVDI模型可以较好地监测山东省干旱情况;且TVDI受温度影响明显大于受降水影响.     

矿用湿式除尘器的发展和现状

首先介绍了矿用湿式除尘器的结构和工作原理,通过对比分析了矿用湿式除尘器较其它除尘器在矿山井下除尘方面的效率优势和特点。随后对国内外矿用湿式除尘器的发展历程进行了回顾,分析了目前我国矿用湿式除尘器行业的现状和水平,提出了目前制约矿用湿式除尘器发展的关键技术。最后对我国矿用湿式除尘器发展前景进行了展望。     

基于正交试验的低温湿喷混凝土力学性能与配比优化研究

为了研究养护温度、钢纤维、减水剂和速凝剂的掺量这4种因素在低温环境下对湿喷混凝土力学性能的影响规律并对其配比进行优化,对湿喷混凝土的早期强度和后期强度进行了极差分析以及方差分析,利用Duncan法事后比较得到初步配比,并建立了湿喷混凝土早期和后期强度回归模型。研究表明：养护温度对于湿喷混凝土早期、后期的抗压强度影响最为明显,前期抗压强度钢纤维掺量影响最弱,后期强度速凝剂掺量影响最弱。在方差分析中,钢纤维、减水剂掺量和养护温度对湿喷混凝土的早期、后期强度都有极显著影响,而速凝剂掺量则仅对早期强度有极显著影响,后期强度无显著影响。基于Duncan法事后比较可得到湿喷混凝土精度略差的初步配比,后续利用回归强度模型实现对湿喷混凝土配比的高精度优化。通过数据模型结合矿山要求得出湿喷钢纤维混凝土最优配比：钢纤维掺量42.496 kg/m³、减水剂掺量7.989 kg/m³、速凝剂掺量66.910 kg/m³,同时最佳养护温度为12℃。     

论办公自动化系统的发展与建设

简要回顾了办公自动化系统的历史、现状及特点，并就内部办公自动化系统的建设阐述了自己的见解。     

基于湿法堆浸工艺的多重渗漏阻隔技术应用

根据湿法堆浸渗漏阻隔技术的应用情况,介绍渗漏阻隔屏障构造、屏障材料和施工方法。     

新型湿式永磁磁选机的研制及对赤铁矿提铁试验研究

新型湿式永磁磁选机的磁系采用稀土钕铁硼和优质铁氧体材料,磁系包角138°,采用开放式磁路设计,磁滚筒表面磁场可达700 mT,比原来顺流型磁选机磁场强度提高40%以上。槽体内表面及磁滚筒外表面粘有耐磨层增加耐磨性,入选矿石粒度直径可达20 mm。通过提铁试验表明,本机运行成本低,使用寿命长,处理量大。-0.074 mm原矿在选别试验中,经过一次粗选的精矿品位可达到52.37%,回收率可达到86.3%,而尾矿则降到36.57%,损失率为13.7%,具有良好的经济效益和社会价值。     

干湿循环作用下岩石力学性质的实验研究

为了模拟风化作用对岩石力学特性的影响.利用MTS815岩石力学测试系统,实验研究了岩石在干湿循环条件下的变形与力学特性,得出:岩石应力应变全过程曲线可分为四个阶段:即初始压密阶段、弹性阶段、应变硬化阶段、应变软化阶段;随干湿循环次数的增加,试件的变形增大;干湿循环作用下,岩石的单轴抗压强度、弹性模量、E50模量减小,且与干湿循环次数呈对数函数关系.研究成果为岩石工程设计与保护具有重要的理论和工程实际意义.