2019年8月22日黑龙江绥滨小地震序列特征

2019年8月22日在黑龙江绥滨发生9次小震活动，地震活动分布的时间与空间相对集中。利用调制地震、震源机制解及视应力等方法，分析此次小震序列活动特征，并结合黑龙江省以往震例，进行震后趋势分析，初步判定，黑龙江绥滨地区后续发生中强地震的可能性较小。     

合成地震记录标定反射层位方法简析

地震层位的标定是地震勘探构造解释的基础,合成地震记录与井旁道对比是层位标定的一个主要方法。层位标定精度除了受地震资料本身的质量及测井资料质量影响之外,制作合成地震记录的准确性取决于地震剖面极性、反射系数、平均速度、地震子波等关键因素的精度。通过介绍确定各种参数的关键技术,提出了在标定地震发射层位中采用的具体方法和标准,如利用相关系数对比时相关系数应大于0.6;利用平均速度对比确定的人工合成地震记录与实际剖面形态差异较小;时深调整前后测井曲线在形态上不应存在差异等。另外为提高对比精度,对目的层段时深关系进行调整时,应结合其他资料,如电性曲线、岩性剖面及钻井地质分层等信息,使之符合地质规律。     

浅谈煤层气与游离气共同开发新思路

游离气是由煤系地层生成的烃类气体,游离于储层储集空间之中而形成天然气气藏,与煤层中的吸附气呈共生关系.根据游离气储集层的岩性及空间组合特征,可将其分为3种类型:煤岩顶板砂岩型、煤岩顶板灰岩型、不整合面灰岩型.测井中子密度重叠法是判别煤系地层游离气层主要的方法之一,拉梅常数、剪切模量及密度预测法可有效识别砂岩中的气饱和层.AVO高异常可准确解释煤层气的富集部位,等温曲线法及补偿中子变化量法能够有效计算煤层气的含气量.游离气与煤层气的成藏特点使得煤层气与游离气共同开发成为可能.以山西沁水盆地为例,介绍了在查明煤层气和游离气富集高产部位后,利用高密度勘探开发井网,有望实现煤层气与煤系地层浅层游离气的联合开发.     

Study on secondary migration of hydrocarbons in Tazhong area of Tarim Basin in terms of carbazole compounds

Fractionated carbazoles have been detected for the first time in crude oils from the Tazhong area of the Tarim Basin, and these nitrogen compounds were successfully utilized in the study of petroleum migration. Alkylcarbazoles are quite abundant in all the samples analyzed; small amounts of benzocarbazoles were detected only in some of the sample, and dibenzocarbazoles were not found in the oils. Based on the distributions of G1, G2 and G3 types of C₂-alkylcarbazoles, the ratio of C₃-/C₂-carbazoles and the relative concentrations of alkylcarbazole and alkylbenzocarbazole, oils in the Carboniferous C_III reservoir in the Tazhong uplift are thought to have laterally migrated to the high level of Tazhong structure No. 4 from both northwest and southeast. The study here also shows that oils in the area may have undergone long-distance migration. This project is financially supported by the China National Petroleum Corporation and the State Educational Commission.     

Vertical structure of the M<Subscript>2</Subscript> tidal current in the Yellow Sea

The vertical structure of the M₂ tidal current in the Yellow Sea is analyzed from data acquired using an acoustic Doppler current profiler. The observed vertical profiles of the M₂ tidal current are decomposed into two rotating components of counter-clockwise and clockwise, and restructured using a simple one-point model with a constant vertical eddy viscosity. The analyzed results show that the internal fictional effect dominates the vertical structure of the tidal current in the bottom boundary layer. In the Yellow Sea, the effect of the bottom friction reduces the current speed by about 20–40% and induces the bottom phase advance by about 15–50 minutes. In the shallower coastal regions, the effects of bottom topography are more prominent on the vertical structure of tidal currents. The vertical profile of the tidal current in summer, when the water column is strongly stratified, is disturbed near the pycnocline layer. The stratification significantly influences the vertical shear and distinct seasonal variation of the tidal current.     

收缩型城市:认知误区、统计甄别与测算反思

收缩型城市是中国城镇化、空间规划与城市治理的全新命题。论文在简要梳理收缩型城市相关文献的基础上总结了当前收缩型城市研究在中国的认知误区。因人口统计口径不一致、划分标准不可比、数量属性与地域空间脱节等原因给科学清晰的识别收缩型城市提出了挑战。在周一星、史育龙（1995）建议的基础上,论文提出了基于实体地域对比与行政地域互验来分析全国城市人口的增减变化及收缩型城市的甄别框架,测算表明：全国有114个建制市2010年的“城人口”规模低于2000年“市人口”规模,但由于2000年“市人口”的偏大统计以及2010年“城人口”存在的“个别水分”,这些城市也未必就全是“收缩型城市”;在剔除乡村人口较高的“城市型政区”后,全国2000年和2010年人口处于净流出状态的建制市分别为56个和75个。论文认为：中国应尽快建立城市实体地域概念,推进城市化区域协同统计制度;要构建“时空对齐”的全国常住人口地理信息系统数据库并综合考虑各地行政区划建制差异,持续推进城乡人口的精准划分。     

新疆贝母(Fritillaria walujewii)的遗传多样性与遗传结构

新疆贝母具较高的药学利用价值,但现存量稀少,被列为新疆Ⅲ级保护植物。为了探明其天然居群的遗传多样性,本研究选取3个叶绿体基因片段对18个居群的235个个体进行测序。结果表明:新疆贝母总的遗传多样性较高;居群间发生了明显的遗传分化;遗传距离与地理距离呈显著的相关性;昭苏县及新源县的居群具有较高的遗传多样性。居群间的地理障碍及自身的有限传播距离可能导致了居群间的遗传分化。较高的遗传灭绝风险提示应该及时对新疆贝母的天然居群进行保护,尤其在遗传多样性较高的昭苏、新源地区。     

金沙江乌东德水电站暴雨概念模型与云型特征

利用自动气象观测站降水资料、常规地面与高空观测资料及卫星云图资料,对2012—2017年6—10月金沙江乌东德水电站坝区18次暴雨个例的大尺度环流背景及卫星云图演变特征进行统计分析,结果表明,切变冷锋型、两高辐合型、西南涡型、孟加拉湾风暴型、切变线型和高空槽型是金沙江乌东德水电站坝区的六类暴雨概念模型。总结归纳出对应的六类典型云型：切变线云带前界处的对流云团8次(占44.4%)、两高辐合云区内部的对流云团4次(占22.2%)、西南涡西南或东南象限的对流云团2次(占11.1%)、孟加拉湾风暴涡旋云系中分离出来的对流云团或对流云系2次(占11.1%)、切变线云带内部的对流云团1次(占5.6%)、高空槽前盾状卷云区南端的对流云系1次(占5.6%)。     

黄土斜坡桩基竖向荷载传递规律现场试验研究

结合某黄土斜坡桥梁桩基工程,对同一坡度相近位置的两根桩基开展现场试验,研究其在不同竖向荷载工况下的桩身上、下坡面两侧的轴力、桩侧摩阻力及桩侧土压力的传递规律与分布特征。试验表明：桩基荷载传递具有明显的区域性,第1区域是从桩顶至约3倍桩径深度处,此区域上坡面桩侧轴力较下坡面相应位置小,且其轴力随深度递减幅度及侧摩阻力发挥程度均较下坡面桩侧大;第2区域是从约3倍桩径至10倍桩径深度处,桩身上坡面一侧竖向受力减小幅度小于桩基下坡面一侧,但此时下坡面桩侧摩阻力发挥幅度大于桩基上坡面一侧;第3区域是从约10倍桩径直至桩端,该区桩身两侧轴力差异不大,摩阻力发挥幅度相近,荷载平衡协调且向下传递稳定。针对斜坡桥梁桩基上、下坡面两侧所受土压力的不均匀性,对设计桩基竖向承载力进行了一定程度地折减,并对计算公式作了相应修正,研究结论可供类似工程参考、借鉴。     

Temperature and thermal growing season variations along elevational gradients on a sub-alpine,temperate China

Fully and accurately studying temperature variations in montane areas are conducive to a better understanding of climate modeling and climate-growth relationships on regional scales. To explore the spatio-temporal changes in air and soil temperatures and their relationship in montane areas, on-site monitoring over 2 years (2015 and 2016) was conducted at nine different elevations from 2040 to 2740 m a.s.l. on Luya Mountain in the semiarid region of China. The results showed that the annual mean of air temperature lapse rate (ATLR) was 0.67 °C/100 m. ATLR varied obviously in different months within a range of 0.57~0.79 °C/100 m. The annual mean of the soil temperature lapse rate (STLR) was 0.48 °C/100 m. Seasonally, monthly mean soil temperature did not show a consistent pattern with regard to elevation. The relationships between air and soil temperatures showed piecewise changes. Soil was decoupled from the air temperature in cold winter and early spring. The parameters of the growing season based on the two temperature types had no corresponding relations, and seasonal mean of soil temperature showed the smallest value at mid-elevation rather than in the treeline ecotone. Based on these changes, our results emphasized that altitudinal and seasonal variability caused by local factors (such as snow cover and soil moisture) should be taken into full consideration in microclimate extrapolation and treeline prediction in montane areas, especially in relation to soil temperature.