鄂尔多斯盆地三叠系延长组长7段浊积扇对油气聚集的控制

鄂尔多斯盆地三叠系延长组长7段为湖盆环境,盆地深湖区以深湖泥岩沉积为背景,普遍发育浊流沉积,沉积范围广、厚度大,近源的先天优势使其成为油气充注的最先储集单元。弄清浊积扇的沉积特征及不同微相形成的砂体对油气聚集具有重要意义。通过野外剖面分析与岩心观察统计,对浊积扇微相进行精细划分,明确浊积岩的形状、展布与沉积特征。根据前人研究成果,将有固定补给水道的浊积扇和无固定补给水道的浊积扇划分为坡移浊积扇和滑塌浊积扇。通过单砂体厚度、浊积岩类型与发育位置的不同,将坡移浊积扇划分为内扇、中扇、外扇3个亚相和主沟道、溢岸沉积等6个微相;滑塌浊积扇相划分出中心扇和边缘扇2个亚相。浊积扇微相的划分及其成因的讨论能够指导测井对有利砂体的解释,区分不同的油气储集体,为寻找有利油气储层的分布提供依据。     

天山北坡精河1615—2007年径流量变化的树轮记录

中国天山北坡西部精河流域山区的树木年轮记录了气候与水文变化过程,利用树轮宽度重建流域径流量长期变化历史对艾比湖湿地自然保护区生态保护和流域水资源利用具有重要意义.建立了精河流域山区2个采样点的天山云杉树轮宽度年表,分析其对流域气象和水文要素的响应特征,建立了树轮宽度标准年表与精河水文站上年9月到当年8月径流量的线性转换方程(R2=37.5%, P<0.001),重建了公元1615—2007年的径流量变化历史.丰枯年份和持续丰枯期分析表明:精河出山口径流量重建序列包含7个丰水年和11个枯水年,且发生了13次持续丰水期和10次持续枯水期.多窗谱分析发现径流量序列在99%的置信水平上存在56.8 年、6.9 年、3.8 年、3.4 年、2.0~2.1 年周期,其中6.9 年对应厄尔尼诺-南方涛动(ENSO)事件的周期,同时还发现了重建序列与南方涛动指数的显著负相关(r =-0.329,n=56),表明研究区径流量受大尺度海气耦合模式的影响.精河径流量序列与天山北坡玛纳斯河和乌鲁木齐河的丰枯阶段以及天山山区、伊犁地区降水变化的干湿阶段较好的对应,表明天山北坡水文和气候变化的大尺度环流背景和驱动因子一致.     

The polypeptide in Chlamys farreri can protect human dermal fibroblasts from ultraviolet B damage

To investigate the effect of polypeptide fromChlamys farreri (PCF) on NHDFin vitro, we modeled oxidative damage on normal human dermal fibroblasts (NHDF) exposed to ultraviolet B (UVB). In this study, 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) were tested to measure cell viability. Enzymes including superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), catalase (CAT) and xanthine oxidase (XOD) were determined biochemically. Total antioxidative capacity (T-AOC) and anti-superoxide anion capacity (A-SAC) were also determined. Ultrastructure of fibroblasts was observed under transmission electron microscope. The results showed that: UVB (1.176×10⁻⁴ J/cm²) suppressed the growth of fibroblasts and the introduction of PCF (0.25%–1%) before UVB reduced the suppression in a concentration-dependent manner. PCF could enhance the activities of SOD, GSH-PX and T-AOC as well as A-SAC. Also PCF could inhibit XOD activity, while it did not affect CAT activity. Ultrastructure of fibroblasts were damaged after UVB irradiation, concentration-dependent PCF reduced the destructive effect of UVB on cells. These results indicated that PCF can protect human dermal fibroblasts from being harmed by UVB irradiation via its antioxidant proerty. This work was supported by the National Natural Science Foundation of China (No. 39970638) and the Science and Technology Bureau of Qingdao (No. 2001-28-50).     

Finite element simulation of stress change for the MS7.4 Madoi earthquake and implications for regional seismic hazards

On May 22, 2021, the M_S 7.4 earthquake occurred in Madoi County, Qinghai Province; it was another strong event that occurred within the Bayan Har block after the Dari M_S 7.7 earthquake in 1947. An earthquake is bound to cast stress to the surrounding faults, thus affecting the regional seismic hazard. To understand these issues, a three-dimensional viscoelastic finite element model of the eastern Bayan Har block and its adjacent areas was constructed. Based on the co-seismic rupture model of the Madoi earthquake, we analyzed the co- and post-seismic Coulomb stress change caused by the Madoi earthquake on the surrounding major faults. The results show that the Madoi earthquake caused significant co-seismic stress increases in the Tuosuo Lake and Maqin-Maqu segments of the East Kunlun fault (>10 ?kPa), which exceeded the proposed threshold of stress triggering. By integrating the accumulation rate of the inter-seismic tectonic stress, we conclude that the Madoi earthquake caused future strong earthquakes in the Tuosuo Lake and Maqin-Maqu segments of the East Kunlun fault to advance by 55.6-623 and 24.7-123 ?a, respectively. Combined with the influence of the Madoi earthquake and the elapsed time of the last strong earthquake, these two segments have approached or even exceeded the recurrence interval of the fault prescribed by previous research. In the future, it is necessary to focus greater attention on the seismic hazard of the Maqin-Maqu and Tuosuo Lake segments. This study provides a mechanical reference to understand the seismic hazard of the East Kunlun fault in the future, particularly to determine the seismic potential region.     

树轮记录的过去359a阿勒泰地区初夏气温变化

利用采集自阿尔泰山南坡森林上限3个采样点的西伯利亚落叶松(Larix sibirica Ledeb.)树芯样本,研制其树轮宽度年表。与区域内6个气象站点观测数据的相关分析结果表明,标准化宽度年表与6月平均气温相关较好,最高相关系数达0.675（p<0.0001）。使用逐步回归分析方法,建立温度的重建方程,调整自由度后的方差解释量为45.6%（1962~2012年）。过去359年来,阿勒泰地区平均气温变化存在7个偏暖（1667~1681年、1714~1728年、1747~1779年、1787~1800年、1862~1887年、1935~1968年、2000~2012年）和6个偏冷阶段（1682~1713年、1729~1746年、1780~1786年、1801~1861年、1888~1934年、1969~1999年）。并存在5个温暖年、54个偏暖年、252个正常年、37个偏冷年、以及11个寒冷年。6月平均温度的最高值出现在1830年（22.35℃）,最低温度出现在1985年（17.87℃）。功率谱分析显示该重建序列存在30.0年、7.4年的显著准周期（p<0.05）和6.4年的较显著准周期（p<0.10）。     

Study on Postseismic Impact of Wenchuan Earthquake on the Sichuan-Yunnan Region Based on Three-Dimensional Viscoelastic Finite Element Method

Based on the lateral segmentation and vertical stratification characteristics of the crustal medium in Sichuan-Yunnan region,and the asymmetry of the static dislocations on the coseismic fault plane of the Wenchuan M_S8. 0 earthquake,we built a three-dimensional viscoelastic finite element model of the crust in the Sichuan-Yunnan region. The postseismic impact of the Wenchuan M_S8. 0 earthquake on the Sichuan-Yunnan region was studied.The results show that:① The far-field horizontal deformation caused by the viscoelastic relaxation of the medium in the 10 years after the earthquake is about 0-20 mm within the Sichuan-Yunnan diamond-shaped block,which has a greater influence on north side and smaller on south side.② In the 10 years after the earthquake,the far-field vertical deformation caused by the viscoelastic relaxation effect of the medium is small,and it shows an increase of about 0-4 mm in most areas of the Sichuan-Yunnan diamond-shaped block.③ The Xianshuihe fault and the eastern segment of the East Kunlun fault,which are close to the seismogenic fault,show a high gradient on deformation fields after the earthquake.④ In order to compare with the strong earthquake activity in the SichuanYunnan region after the Wenchuan earthquake, the horizontal stress state and the Coulomb failure stress change of the active block boundary are also calculated. From the spatial distribution of the coseismic and postseismic displacement field,the fault activity characteristics reflected by the stress state and the stress loading of the fault layer reflected by the Coulomb failure stress change,there is a certain correlation with the spatial distribution of strong earthquake activity in this region.     

正常高值血压患者心血管危险因素和中医体质的相关性研究

目的：通过对正常高值血压患者进行中医体质分型,统计患者的血管紧张素Ⅱ（AngⅡ）等心血管危险因素,通过危险因素和中医体质的相关性分析,探讨高危人群的中医体质特征。方法：采用中医体质评分量表对150例正常高值血压患者进行中医体质分类,运用体质九分法,并记录患者的身高、体质量、吸烟史、饮酒史、家族史、血浆AngⅡ、血糖、低密度脂蛋白胆固醇（LDL-C）等,利用统计学方法处理数据,寻找AngⅡ、身体质量指数（BMI）、血糖、LDL-C、年龄、吸烟史、饮酒史、家族史等因素和中医体质之间的相关性,从而通过此类心血管危险因素筛选出正常高值血压人群中的高危体质。结果：不同中医体质人群在吸烟史、饮酒史、家族史方面,差异无统计学意义（P＞0.05）,痰湿质和湿热质人群的AngⅡ、BMI、血糖、LDL-C明显高于其他体质人群,差异有统计学意义（P＜0.05）。结论：痰湿质和湿热质属于高危体质,其发展为高血压病的风险比其他体质高,应予以早期干预。     

Fluid Property Discrimination in Dolostone Reservoirs Using Well Logs

The Ordovician Majiagou Formation is one of the main gas-producing strata in the Ordos Basin,China.The identification of hydrocarbon-bearing intervals via conventional well logs is a challenging task.This study describes the litholog of Ma 5(Member 5 of Majiagou Formation)dolostones,and then analyzes the responses of various conventional well logs to the presences of natural gas.The lithology of the gas bearing layers is dominantly of the dolomicrite to fine to medium crystalline dolomite.Natural gas can be produced from the low resistivity layers,and the dry layers are characterized by high resistivities.Neutron-density crossovers are not sensitive to the presences of natural gas.In addition,there are no significant increases in sonic transit times in natural gas bearing layers.NMR(nuclear magnetic resonance)logs,DSI(Dipole Sonic Imager)logs and borehole image logs(XRMI)are introduced to discriminate the fluid property in Majiagou dolostone reservoirs.The gas bearing intervals have broad NMR T_2(transverse relaxation time)spectrum with tail distributions as well as large T_(2gm)(T_2 logarithmic mean values)values,and the T_2 spectrum commonly display polymodal behaviors.In contrast,the dry layers and water layers have low T_(2gm) values and very narrow T_2 spectrum without tails.The gas bearing layers are characterized by low V_p/V_s ratios,low Poisson’s ratios and low P-wave impedances,therefore the fluid property can be discriminated using DSI logs,and the interpretation results show good matches with the gas test data.The apparent formation water resistivity(AFWR)spectrum can be derived from XRMI image logs by using the Archie’s formula in the flushed zone.The gas bearing layers have broad apparent formation water resistivity spectrum and tail distributions compared with the dry and water layers,and also the interpretation results from the image logs exhibit good agreement with the gas test data.The fluid property in Majiagou dolostone reservoirs can be discriminated through NMR logs,DSI logs and borehole image logs.This study helps establish a predictable model for fluid property in dolostones,and have implications in dolostone reservoirs with similar geological backgrounds worldwide.     

Acceleration Phase of Coronal Mass Ejections: I. Temporal and Spatial Scales

We study kinematics of 22 coronal mass ejections (CMEs) whose motion was traced from the gradual pre-acceleration phase up to the post-acceleration stage. The peak accelerations in the studied sample range from 40, up to 7000 m s⁻², and are inversely proportional to the acceleration phase duration and the height range involved. Accelerations and velocities are, on average, larger in CMEs launched from a compact source region. The acceleration phase duration is proportional to the source region dimensions; i.e., compact CMEs are accelerated more impulsively. Such behavior is interpreted as a consequence of stronger Lorentz force and shorter Alfvén time scales involved in compact CMEs (with stronger magnetic field and larger Alfvén speed being involved at lower heights). CMEs with larger accelerations and velocities are on average wider, whereas the widths are not related to the source region dimensions. Such behavior is explained in terms of the field pile-up ahead of the erupting structure, which is more effective in the case of a strongly accelerated structure.