陕西油页岩地质特征及找矿远景

陕西具有丰富的油页岩资源,鄂尔多斯盆地是西北地区有关油页岩记录最多的地区,油页岩分布层位包括侏罗系延安组、安定组,三叠系延长组,二叠系山西组及石炭系太原组.在收集前人油页岩资料的基础上,根据陕西省油页岩资源特征和成矿条件,提出了12个找矿远景区,并建议对全省油页岩资源开展远景调查工作,大致查明区内油页岩的埋深、层数、分布范围、厚度变化、油质特征、工业用途,估算推断的、预测的资源量,为下步勘查工作部署提供依据.     

Morphological Characteristics of （K, Na）-Rectorite from Zhongxiang Rectorite Deposit, Hubei, Central China

The morphological characteristics of the Zhongxiang (钟祥) rectorite have been studied using X-ray diffraction (XRD), electron probe micro-analyzer (EPMA), scanning electron microscopy (SEM), atomic force microscope (AFM), and high-resolution transmission electron microscopy (HRTEM). The structural formula of the Zhongxiang rectorite is: interstratification of (K, Na)-mica and Ca-montmorillouite. SEM observations show that Zhongxiang rectorite occurs as platy and fold-shaped crystals, and mainly as extremely thin plates with thickness ranging from 0.4 to 0.05 μm and a smooth (001) surface. There are well-developed polygonal steps on the surfaces of some thick crystals, suggesting a layer-by-layer growth mechanism. AFM observations show a series of steps with a height of 2 nm on the platy particles, suggesting the stacking of 20 nm fundamental particles. Club-like or fiber-shaped halloysite is included in the platy crystals with their elongated dimension paralleling (001) of the platy crystals or crossing the (001) surface of the platy rectorite, indicating multi-stage crystallization and involvement of hydrothermal fluids. The Zhongxiang rectorite was generated by both layer-by-layer growth mechanism and dissolution and crystallization growth mechanism with multistages.     

社会—生态系统视角下农户对禁牧政策的适应性——以宁夏盐池县为例

为了保护草原生态环境,2002年起国家全面实施“退牧还草”工程,在草原破坏严重的地区实施禁牧政策。政策实施后,草地生态明显恢复。作为草原最主要的经济活动主体和禁牧政策的最直接承受者,农户对政策的适应性直接影响政策的顺利进行以及生态环境恢复的可持续性。基于宁夏盐池县入户调查资料,研究了不同类型农户对禁牧政策的生态环境效应感知以及对禁牧政策适应能力感知,分析了不同类型农户对禁牧政策的应对策略,探讨了影响农户适应策略选择的主要因素。结果表明：（1）盐池县社会-生态系统尚处于不理想的系统稳态,生态系统恢复明显,但社会系统的适应性较低。农户普遍认为禁牧政策实施对生态环境有很大的改善,但对禁牧政策满意度感知处于中等水平,对禁牧政策适应能力的感知处于较低水平。由于生计方式和收入水平的差异,不同类型农户对禁牧政策的适应性感知差异较大。（2）不同类型农户采取不同适应策略应对禁牧政策实施造成的影响。纯农户适应策略以收缩型为主,兼业户和非农户以调节型为主,低收入和中等收入农户以收缩型为主,高收入农户以调节型为主。（3）农户对禁牧政策的适应成本、自我效能和农户拥有的人力资本、金融资本是影响农户适应性策略类型选择的主要因素。     

科尔沁沙地沙漠化风险评价

基于气象、土地利用类型与植被覆盖指数等数据,采用层次分析法与加权综合评分法评价了科尔沁沙地沙漠化风险。结果表明：1995、2000、2010年科尔沁沙地沙漠化风险指数平均值分别为0.420、0.428、0.437,16年来科尔沁沙地沙漠化处于高度风险水平。科尔沁沙地沙漠化风险等级在空间分布上表现为北部与西部沙漠化风险等级低,南部与东部为沙漠化高风险区。1995-2010年科尔沁沙地各旗县沙漠化风险等级存在差异,开鲁县的沙漠化风险由高度风险转变为极高度风险等级,扎鲁特旗的沙漠化风险由中度风险转变为低度风险等级,敖汉旗、巴林右旗、科尔沁区与科尔沁左翼中旗的沙漠化风险等级波动变化,其余旗县的沙漠化风险等级未变化。1995-2010年科尔沁沙地沙漠化中度,高度风险等级的面积分别减少了16 544.76、4 223.25 km²,低度,极高度风险等级的面积分别增加了16 544.76、4 223.25 km²。区域沙漠化风险的主要影响因素为年降水量、年均风速、植被覆盖指数、沙漠化土地面积与载畜量,植被覆盖指数增加有助于区域沙漠化风险的降低。     

网格技术研究进展

介绍了网格的概念,以及网格体系结构、网格资源管理和网格应用等网格技术的研究现状, 最后对中国地震减灾仿真网格试验系统的研究概况进行了介绍。     

小高层住宅结构方案--大开洞剪力墙与异型柱框剪结构对比分析

通过对某小区小高层住宅2种结构方案的综合讨论,分析了小高层住宅的合理结构型式,提出了设计建议可供工程设计参考。异型柱框架-剪力墙结构框架柱布置灵活、隐蔽性好,但其柱截面不规则、计算理论不成熟、抗震能力较差、构造措施不理想、而且建筑自振周期长,侧向位移大,难以用于较高的高层住宅和抗震烈度较高的地区;大开洞剪力墙结构受力明确、计算理论成熟,又有较为精确的计算程序,而且墙厚可以在规范允许的范围内减薄,从而进一步降低了工程造价。通过2种方案比较,认为大开洞剪力墙体系与异型柱框剪结构相比,配筋总量基本接近,但其侧移较小,具有较好的延性,可应用于小高层住宅和地震烈度较高地区并可取得显著经济效益。     

康滇地轴中段西缘二叠纪火山岩岩石地球化学特征

沿扬子地台西缘与松潘甘孜造山带东缘结合部中段两侧分布的二叠纪火山岩,分别代表攀西裂谷时期海相和陆相环境中的火山喷发产物。西部为海相高钾钙碱性—碱性拉斑玄武岩系列,东部为陆相低钾钙碱性拉斑玄武岩系列;两者的来源深度不一,前者较后者相对较深。     

Sound speed profiles in high spatiotemporal resolution using multigrid three-dimensional variational method: a coastal experiment off northern Shandong Peninsula

It is essential to acquire sound speed profiles (SSPs) in high-precision spatiotemporal resolution for undersea acoustic activities. However, conventional observation methods cannot obtain high-resolution SSPs. Besides, SSPs are complex and changeable in time and space, especially in coastal areas. We proposed a new space-time multigrid three-dimensional variational method with weak constraint term (referred to as STC-MG3DVar) to construct high-precision spatiotemporal resolution SSPs in coastal areas, in which sound velocity is defined as the analytical variable, and the Chen-Millero sound velocity empirical formula is introduced as a weak constraint term into the cost function of the STC-MG3DVar. The spatiotemporal correlation of sound velocity observations is taken into account in the STC-MG3DVar method, and the multi-scale information of sound velocity observations from long waves to short waves can be successively extracted. The weak constraint term can optimize sound velocity by the physical relationship between sound velocity and temperature-salinity to obtain more reasonable and accurate SSPs. To verify the accuracy of the STC-MG3DVar, SSPs observations and CTD observations (temperature observations, salinity observations) are obtained from field experiments in the northern coastal area of the Shandong Peninsula. The average root mean square error (RMSE) of the STC-MG3DVar-constructed SSPs is 0.132 m/s, and the STC-MG3DVar method can improve the SSPs construction accuracy over the space-time multigrid 3DVar without weak constraint term (ST-MG3DVar) by 10.14% and over the spatial multigrid 3DVar with weak constraint term (SC-MG3DVar) by 44.19%. With the advantage of the constraint term and the spatiotemporal correlation information, the proposed STC-MG3DVar method works better than the ST-MG3DVar and the SC-MG3DVar in constructing high-precision spatiotemporal resolution SSPs.

     

长输埋地管道振动台试验传感器布置方案研究

在进行长输埋地管道振动台试验的过程中,针对数据信息的采集量测以及传感器的布置位置进行了研究。采用三维数值模拟的方法对管-土相互作用体系进行了地震反应分析,内容包括埋地管道结构纵、横向在非一致地震动作用下的地震响应及受力变形特征。根据计算结果确定了主观测断面及辅助观测断面的位置及观测断面上传感器布置的位置,在满足基本信息采集要求的前提下,对可供采用的信息采集通道进行了优化分配,由此确定本次试验的观测断面以及传感器的具体测量部位与数目。成果对试验获得成功起到了保障作用,可为同类试验提供参考。     

Net primary productivity and its control of the Middle Jurassic peatlands: An example from the southern Junggar coalfield

The Jurassic is an important period of global coal formation, including the development of several large coalfields in central Asia and northern China. Individual seams within these peatlands represent sustained periods of terrestrial carbon accumulation and a key environmental indicator attributed to this record is the rate of carbon accumulation. Determining the rate of carbon accumulation requires a measure of time contained within the coal and this study aimed at determining the rate via the identification of Milankovitch orbital cycles using spectral analysis. Spectral analyses of geophysical data from two thick coal seams, No. 43(35.9 m) and No. 3(13.2 m), of the Middle Jurassic of the southern Junggar coalfield were conducted to identify significant signals of variations in ash content. The results showed that the variations in ash content of the coal showed spatial cycles at 0.2, 0.7 and 1.1 m~(-1), which were interpreted to represent 123 ka(eccentricity), 37.1 ka(obliquity), and 21.2 ka(precession) orbital periodicities, respectively. Using this timeframe, the depositional time of the No. 43 and No. 3 coal seams were calculated to be 876–970 and 322–357 ka, respectively. In combination with an understanding of carbon loss during coalification, the carbon accumulation rates of these Middle Jurassic peatlands were calculated to be 58.6–64.9 and60.3–66.8 g C m~(-2) a~(-1) for the No. 43 and No. 3 coal seams, respectively. Given that the net primary productivity(NPP) was 4.3 times the value of the carbon accumulation in a mid-latitude region of 40°–45°N, an NPP of 251.8–279.1 and259.1–287.1 g C m~(-2) a~(-1) was calculated for the No. 43 and No. 3 coal seams, respectively. In the context of the same paleolatitude(40°–45°N) and peat type, the NPP values of the Middle Jurassic strata in the study area were higher than those of the peatlands of the Holocene and Permian, and were similar to the NPP values of Early Cretaceous peatlands. Considering the NPP of a peatland is predominantly controlled by atmospheric CO_2 and O_2 levels and temperature, the lower content of CO_2 and an excessive O_2 level in the temporal atmosphere would lead to a decrease in peatland NPP. Therefore, it is inferred that the CO_2 level during the Middle Jurassic was higher than that of the icehouse Permian and Holocene periods, and it was similar to the CO_2 level of the greenhouse Cretaceous period. The results are consistent with the global CO_2 variation curve of Berner. In conclusion, Milankovitch orbital cycles calculated from geophysical logs can be used to infer the NPP of temporal peatlands during different geological periods, based on which the deep-time paleoclimates can be analyzed.