广东肇庆端砚石中石眼的矿物组成和成因研究

历代以来人们对广东肇庆端砚中的石眼十分关注,因为石眼是提高端砚的鉴赏品位和市场价值的重要因素之一。梅花坑砚石是端砚石中的一种,以梅花坑砚石的石眼作为样品,用显微激光拉曼光谱测试技术,研究和测定了石眼不同部位的矿物组成。实验结果表明,砚石和石眼中均有碳存在,只是砚石中石眼(含眼瞳、眼球、眼睑)附近的基体部位碳多以微晶石墨的物相形式存在,而在石眼的眼睑处的碳则以碳球形式存在;石眼的眼睑处颜色变黑,是由赤铁矿、石墨含量的增多以及黑色玻璃相的出现而引起的;相反,石眼眼球部位颜色变浅,是因为伊利石和石英是主成分、赤铁矿和石墨含量少以及没有绿泥石的存在而造成的。石眼的"瞳子"部位呈红褐色,是来源于金红石的颜色,不是行内长期以来认为的是由赤铁矿造成的。紫色端砚石品石眼的形成与火山作用密切相关,石眼是火山泥球在海湾或潮坪环境中沉积的粉砂质泥岩在后期浅变质作用条件下的变质残余。     

Gully and soil and water conservation structure densities in semi‐arid northern Ethiopia over the last 80 years

Gullies have been a common phenomenon in semi‐arid northern Ethiopia for the last centuries. However, soil and water conservation (SWC) structures have been implemented for a long time to curb soil erosion. Though, like most of the affected areas worldwide, density and distribution of gullies and SWC structures, their causes and interrelations are poorly understood. The aims of this study were to develop a technique for mapping these densities of gullies and SWC structures, to explain their spatial distribution and to analyze changes over the period 1935–2014. Aerial photographs from 1935 to 1936 and Google Earth images from 2014 of the 5142 km² Geba catchment were used. Transect lines were established to count gullies and SWC structures in order to calculate densities. On average, a gully density of 1.14 km km^?2 was measured in 1935–1936 of which the larger portion (75%) were vegetated, indicating they were not very active. Over 80 years, gully density has significantly increased to 1.59 km km^?2 with less vegetation growing in their channel, but 66% of these gullies were treated with check dams. There was c. 3 km km^?2 of indigenous SWC structures (daget or lynchets) in 1935–1936 whereas a high density (20 km km^?2) of introduced SWC structures (mainly stone bunds and terraces) were observed in 2014. The density of gullies is positively correlated with slope gradient and shrubland cover and negatively with cropland cover, whereas the density of SWC structures significantly increased with increasing cropland cover. Density maps of gullies and SWC structures indicate sensitive areas to gully formation and priority areas for the implementation of SWC structures in Geba catchment. The obtained results illustrate the feasibility of the methods applied to map the density of gullies and SWC structures in mountainous areas. Copyright © 2018 John Wiley & Sons, Ltd.     

渤南洼陷沙三下亚段泥页岩储集空间研究:以罗69井为例

济阳坳陷渤南洼陷沙三下亚段泥页岩厚度大、分布广,主要发育了深灰色泥岩、灰质泥岩、油泥岩、泥质灰岩和黄褐色—灰褐色油页岩。泥页岩的有机碳含量高,最高可达9.0%;生烃潜量高,最高可达82.6mg/g;演化程度高,最高可达3.0%;该区泥页岩既是良好的烃源岩,也是页岩油气赋存的有利场所。为研究该区沙三下亚段页岩油气储集空间,文中通过岩心观察、偏光显微镜、扫描电镜等手段,认为研究区泥页岩储集空间中裂缝包括构造裂缝、层间微裂缝、超压破裂缝;空隙主要为微孔隙,包括黄铁矿晶间孔、粘土矿物晶间孔、方解石晶间孔。总体上来讲,储集空间以构造张裂缝、层间微裂缝、粘土矿物晶间孔及方解石晶间孔为主导。通过对比不同岩相间储集空间的类型与特征,认为沙三下12下、13上砂组纹层状泥质灰岩为储集性能最好的岩相。     

四平杏山黄土堆积的粒度特征及成因探讨

对杏山黄土堆积的粒度分析,发现其粒度特征为:①颗粒分选差,主要由粒径φ值>7.61(0.005 mm)的颗粒组成,平均粒径φ值为7.61～8.26(0.005 mm～0.003 mm);②粒级构成:砂44.75%,粉砂31%,黏土24.25%;③频率曲线以单峰态为主,主要为正偏。结合剖面中其它沉积物的特征,推断该剖面黄土在中、晚更新世冰期时堆积,又于间冰期时在水和风的交替作用下形成现在的状态,即为沙丘成因。这一结论为研究本区黄土堆积的成因和本区第四纪气候的变化提供了一些有价值的资料。     

电阻率法评价膨胀土改良的物化过程

掺石灰、粉煤灰是工程中通常采用的改良膨胀土的方法。土电阻率是土的基本物理指标之一,其变化可反映土的其他物理性质指标的变化。通过掺灰改良膨胀土不同养护龄期下的电阻率测试以及膨胀量、膨胀力及无侧限抗压强度等试验研究,探讨了掺灰改良膨胀土养护过程中的物理化学反应过程。根据养护过程中的电阻率随龄期的变化规律,可将改良膨胀土的物理化学反应过程划分为瞬时反应阶段、主体反应阶段、残余反应阶段和稳定阶段4个不同阶段。针对改良膨胀土质量控制和评价体系中存在的不足,提出了基于电阻率指标的改性膨胀土的质量评价方法,通过试验证实了该方法的有效性和实用性。     

Freeze-thaw performance of chemically stabilized natural and recycled highway materials

This article provides an overview of several previous studies that investigated the stiffness and strength performance of chemically stabilized roadway materials under winter conditions (freeze-thaw cycling). The objective of this research was to understand the behavior of different materials stabilized with different type of binders when they were subjected to freeze-thaw cycling. Nine different materials including natural soils (organic soil, clay, silt, sand, and road surface gravel), reclaimed pavement material, and recycled asphalt pavement stabilized with nine different binders (five different fly ashes, lime, cement, lime kiln dust, cement kiln dust) were discussed. This article investigated how the volume, resilient modulus and unconfined compressive strength of soils/materials stabilized with different binders change in response to freeze-thaw cycling. Overall, the review results indicate that the stiffness and strength of all stabilized materials decrease somewhat with freeze-thaw cycling. However, the reduced strength and stiffness of stabilized materials after freeze-thaw cycling was still higher than that of unstabilized-unfrozen original soils and materials. In addition, materials stabilized with cement kiln dust provided the best performance against freeze-thaw cycling.     

忠县地面石质文物的风化病害研究

忠县地面石质文物风化病害形式有：裂隙状风化、页片状风化、絮粉状风化、松胀状风化。其中以絮粉状风化对文物破坏最为严重。控制风化的主要因素是：岩性和岩体结构、气候和气象条件、人为的污染。现场简易强度测试数据表明，风化石材的力学强度明显下降。最后提出了三峡水库蓄水前，对石质文物搬迁和保护的建议。参加研究工作的还有王金华、陈超平、唐毅烈、邓修甫、卞大巍、黄明元等人。表１３处文物概况Ｔａｂｌｅ１ＳｕｒｖｅｙｏｆｔｈｅｔｈｒｅｅｓｔｏｎｅｃｕｌｔｕｒａｌｒｅｌｉｃｓｉｎＺｈｏｎｇｘｉａｎＣｏｕｎｔｙ表２石材的化学成分（％）Ｔａｂｌｅ２Ｃｈｅｍｉｃａｌｃｏｍｐｏｓｉｔｉｏｎｓｏｆｒｏｃｋｍａｔｅｒｉａｌｓ注：丁房阙石样已非新鲜岩石。表３石材岩块的主要物理力学性质指标Ｔａｂｌｅ３Ｍａｉｎｐｈｙｓｉｃａｌ－ｍｅｃｈａｎｉｃａｌｐａｒａｍｅｔｅｒｓｏｆｒｏｃｋｍａｔｅｒｉａｌｓ注：灰绿色砂岩试验成果取自三峡工程库区环境地质研究有关资料。２石质文物的风化病害分析受自然地质环境及人文环境的制约，３处石质文物的主要环境病害是风化病害。２．１风化病害形式［１］（１）裂隙状风化。这是一种典型的物理风化形式，见于无铭阙和临江岩摩崖造像。无     

Evaluation of seismic behaviour of Cheomseongdae using dynamic centrifuge model test

Cheomseongdae is known to be the oldest astronomical observatory in Asia. According to historical records, the Gyeongju area, where Cheomseongdae is located, suffered from numerous medium‐scale earthquakes. Cheomseongdae has a masonry structure, which is apparently vulnerable to horizontal dynamic loads such as earthquakes. However, despite its appearance, features such as the filler of the lower half, inner irregular‐shaped stones which can induce high frictional resistance, eight long horizontal tie stones inside the artefact, and a grid of interlocking headstones increase its resistance to horizontal dynamic loads. Dynamic centrifuge model tests were performed on Cheomseongdae in order to evaluate the seismic response characteristics of this architectural heritage structure. Model tests were executed on two 1/15‐scale models: one which was an exact duplicate of the original Cheomseongdae and the other without the long horizontal tie stones and grid of interlocking headstones. On the basis of the amplification patterns in the time and frequency domains, the differences in seismic behaviour between the two Cheomseongdae models, and a broken stone at the 19th layer during tests, the long horizontal tie stones and headstones were found to increase the seismic resistance within Cheomseongdae and provide a glimpse of the ‘seismic design’ of our ancestors. Copyright © 2014 John Wiley & Sons, Ltd.     

昌化明矾石石英地鸡血石的宝石矿物学特征

利用宝石学常规手段、偏反光显微镜、红外光谱仪、X射线粉末衍射仪和X荧光光谱仪等测试方法对昌化明矾石石英地鸡血石的宝石矿物学特征进行了较详细的分析。结果发现,该品种鸡血石中的＂地＂主要由明矾石和石英组成,并含少量的黄铁矿和镜铁矿,不含地开石和高岭石。据其透明度、光泽、硬度等特征应归属于＂刚地＂鸡血石,但其矿物组成明显不同于其它含有粘土矿物的昌化＂刚地＂鸡血石。X荧光光谱仪的测试结果显示,样品中含有一定量的Sr和Ba,推测其可能含有少量的天青石-重晶石的类质同象系列矿物。     

动力法计算振冲碎石桩桩体压缩模量

振冲碎石桩为散体结构,所形成的复合地基受垂直荷载后的变形较刚性桩复合地基要大,为研究振冲碎石桩复合地基的沉降规律,建立振冲器动力性能指标与碎石桩桩体强度的关系。根据压缩模量概念,结合振冲桩制桩工艺,建立桩体压缩模量与振冲器激振力、施工中的加密段长、加密电流及留振时间的关系式-动力法。采用动力法和载荷试验法所得的压缩模量在沉降量计算中进行对比,结果与按实际观测推算值的偏差均小于10%。