土壤气氡测量影响因素的初步研究

通过分析实验资料和断层气氡测量中所遇到的问题，较全面地讨论了断层气氡测量中地因素和明因素的影响。分析了断层气氡形态与断层性质的关系，以及岩土性质，土壤含水量和气温，地温，气压对土氡测量的影响。指出只要充分认识并注意避开或消除上术因素的影响就可以得到较满意的气氡测量结果。     

Monitoring periodically national land use changes and analyzing their spatiotemporal patterns in China during 2015–2020

Journal of Geographical Sciences - High-resolution mapping and monitoring of national land use/cover changes contribute significantly to the knowledge of the interaction between human activities...     

增生弧基本特征与地质意义

增生弧是发育在增生楔基底之上的岩浆弧,是由于海沟后撤、新的弧岩浆前缘向着洋的方向迁移至早期增生杂岩基底之上。增生弧的发育是?engör （1992）提出的增生型（突厥型）造山带的核心动力学过程,然而对其识别与大地构造意义尚存诸多争议。日本岛弧是?engör用以建立增生弧模式的范例,其白垩纪以来的岩浆弧发育在侏罗纪和更早的增生杂岩基底之上。日本岛弧的增生弧岩浆具有典型的岛弧型微量元素地球化学特征,包括富集的LREE和LILE、以及亏损的HFSE,但其Sr-Nd同位素随着海沟后撤和增生弧演化不断变亏损。地球物理剖面显示日本增生弧岩浆来自两个截然不同的岩浆源区,一个位于弧前俯冲大洋岩石圈莫霍面之上,一个位于弧岩浆轴部的莫霍面之下,这可能暗示了日本增生弧具有增生楔重熔和增生弧地幔楔部分熔融两种不同的岩浆形成机制,但增生弧的地幔楔如何形成这一问题尚未得到解决。中亚造山带是增生型造山带,其西段的西准噶尔地区出露早古生代成吉斯弧和晚古生代萨吾尔弧,均为增生弧。萨吾尔弧晚石炭世的弧岩浆岩以Ⅰ型花岗岩、花岗闪长岩—闪长岩岩墙、中-基性火山熔岩等为代表,发育在包括有蛇绿混杂岩、OPS混杂岩、连续单元浊积岩的增生杂岩基底之上这些侵入岩和喷出岩与增生楔物质分别呈侵入和不整合覆盖接触关系。成吉斯弧早泥盆世的弧岩浆岩以中-基性火山熔岩为代表,不整合覆盖在混杂带基底之上;其中混杂带的基质为晚志留世砂岩,夹持有晚奥陶世—晚志留世灰岩、硅质岩等岩块。以上案例展示了增生弧具有典型的二元结构：上盘为晚期增生弧弧岩浆、下盘是早期增生杂岩基底,二者被一个大型的不整合面分隔或构成岩浆侵入接触关系。萨吾尔增生弧岩浆岩具有典型的岛弧型微量元素地球化学特征,花岗岩端元Nd同位素亏损、Sr同位素富集,而玄武岩端元的Sr-Nd同位素均表现为亏损特征,表明基性岩端元直接源自新生的增生弧地幔楔的部分熔融,继承了亏损地幔的同位素特征;酸性岩端元则受到增生楔物质重熔的混染,如富集的Sr同位素,源自增生楔中大洋沉积物和蛇绿岩。增生弧的发育可能是增生型造山带大量年轻地幔物质加入和大规模地壳生长的原因。这一现象还可以进一步地探讨增生弧地幔楔的成因：即随着海沟后撤,原海沟位置的俯冲大洋岩石圈并不会发生断离下沉,而是保留在原位、形成新的增生弧地幔楔。     

河流相油气储层的井震结合相控随机建模约束方法

河流相油气储层的研究传统上多是只依据井点资料,先在井上进行沉积相的划分,而后进行剖面相的分析,最后再结合平面沉积参数等值线图编制平面相图,这样往往会造成"见砂画河,吾跟勘探走"的局面,这种平面相图在井间可能存在着较大的误差。然而,平面相图的正确与否直接影响着储层建模中相控的结果。为此作者提出了一种井震结合进行沉积相图编制的新方法,即"以河找砂,指导勘探行"的思路,并在此基础上进行分层次地相控约束随机建模。同时提出相控建模的三个基本的约束条件,即首先要保证随机建模模型的"相序"符合地质规律;其次要保证建模实现的微相分布统计概率与单井沉积微相数据离散化至三维网格后的统计概率相一致;第三要确保三维数据中每种微相的变差函数特征与定量地质知识库一致。因而,从沉积形成与演化的成因角度来指导沉积储层随机建模过程,应用多参数协同、分层次约束的方法,以河道的平面展布和垂向演化来控制建模的结果,使其更逼近地下地质的真实。     

The influence of seafloor hydrothermal activity on major and trace elements of the sediments from the South Mid-Atlantic Ridge

Sediment samples obtained from the South Mid-Atlantic Ridge were analyzed for the major and trace elements by inductively coupled plasma atomic emission spectroscopy and inductively coupled plasma mass spectrometry. Results revealed that the contents of elements (e.g., Fe, Mn, Cu, Zn, V, Co) were high in samples 22V-TVG10 and 26V-TVG05 from the sites near the hydrothermal areas, and low in sample 22V-TVG14, which was collected far from the hydrothermal areas. The contents of Ca, Sr and Ba in the samples showed opposite trends. A positive correlation between the concentrations of metallic elements (Cu, Zn, Co, Ni, Pb, V) and Fe in the samples were observed. These results are consistent with chemical evolution of the dispersing hydrothermal plume.     

State of China's climate in 2021

This report is a summary of China's climate, as well as major weather and climate events, during 2021. In 2021, the mean temperature in China was 10.5°C, which was 1.0°C above normal (1981–2010 average) and broke the highest record since 1951. The annual rainfall in China was 672.1 mm, which was 6.7% above normal. Also, the annual rainfall in northern China was 40.2% above normal, which ranked second highest since 1961. The rainstorm intensity in the rainy season was strong and featured significant extremes, and disasters caused by rainstorms and flooding were more serious than the average in the past decade. In particular, the extremely strong rainstorm in Henan during July and autumn caused flooding in the middle and lower reaches of the Yellow River with severe consequences. Heatwaves occurred more frequently than normal, and their durations in southern China were longer than normal in summer and autumn. Phased drought was obvious, and caused serious impacts in South China. The number of generated and landfalling typhoons was lower than normal; however, Typhoon In-fa broke the record for the longest overland duration, held since 1949, and affected a wide area. Severe convective weather and extreme windy weather occurred frequently, causing serious impacts. The number of cold waves was more than normal, which caused wide-ranging extremely low temperatures in many places. Sandstorms appeared earlier than normal in 2021, and the number of strong dust storm processes was more than normal.摘要2021年, 中国气候暖湿特征明显, 全国平均气温10.5℃, 较常年偏高1.0℃, 创下了1951年以来最高纪录; 全国平均降水量672.1毫米, 比常年偏多6.7%, 其中北方地区平均降水量较常年偏多40.2%, 为1961年以来第二多. 汛期暴雨过程强度大, 极端性显著, 河南特大暴雨灾害影响重, 黄河中下游流域秋汛明显; 高温过程多, 夏秋南方高温持续时间长; 区域性, 阶段性气象干旱明显, 华南干旱影响较重; 台风生成和登陆均偏少, “烟花”陆地滞留时间长, 影响范围广; 强对流天气强发, 极端大风频发, 局地致灾重; 寒潮过程多, 强度大, 极端低温频现; 沙尘天气出现早, 强沙尘暴过程多.     

Permeability tensor and representative elementary volume of fractured rock masses

Based on a simulation of three-dimensional fracture networks and a superposition principle of liquid dissipation energy for fractured rock masses, a model of the fracture permeability tensor is proposed. An elastic constitutive model of rock fractures, considering fracture closure and dilation during shearing, is also proposed, based on the dilation angle of the fracture. Algorithms of flow-path searching and calculation of the effective flow coefficients for fracture networks are presented, together with a discussion on the influence of geometric parameters of the fractures (trace length, spacing, aperture, orientation and the number of fracture sets) on magnitude, anisotropy of hydraulic permeability and the size of a representative elementary volume (REV). The anisotropy of hydraulic permeability of fractured rock masses is mainly affected by orientation and the number of fracture sets, and the REV size is mainly influenced by trace length, spacing and the number of fracture sets. The results of studies on REV size and the influence of in-situ stress on hydraulic conductivity of the rock mass on the slope of Jinping-I hydropower station, China, are presented using the developed models and methods. The simulation results agreed well with the results obtained from field water-pressure measurements, with an error of less than 10 %.     

The Major Mode of the Shaanxi Thunderstorm and Possible Influence Mechanism

Based on observational data of thunderstorm and lightening of 76 stations in Shaanxi, the National Centers for Environmental Prediction / National Centers for Atmospheric Research (NCEP/NCAR) reanalysis dataset from 1960 to 2010, the major modes of thunderstorm in warm seasons (May to September) of Shaanxi province and mechanism of its possible influence are studied .The results show that:①the thunderstorms show an obvious decreasing trend in the past 51 years, the average thunderstorm days reaching the peak in July, of which 70% occurred in warm season.②There are two dominant modes: EOF1 mode depicting a thunderstorm phase oscillation between the East and the West of Shaanxi province and EOF2 mode describing negative anomaly oscillation between the North and the middle of Shaanxi province and positive anomaly oscillation between Yan’an area and some areas of Southern Shaanxi province. These two modes account for 53.1% and 13.6% of total variance respectively. ③Analysis with Morlet wavelet method indicates that EOF1 mode has an inter annual changing cycle of 3 to 6 years and EOF2 has an interdecadal change cycle of about 15 years.④The meteorological field regression of EOF1 time coefficient shows the West Pacific subtropical high 584 line is located near 30°N ,the flowing of the southwest warm wet airflow to the north increases and the thunderstorms increase in the west of Shaanxi province; the time coefficient regression of EOF2 shows that the Northern Hemisphere polar vortex is weaker and the pressure over Mongolia area is stronger than usual result in the north wind component’s increasing ,which contributes to the formation EOF2. ⑤The important factors influencing Shaanxi thunderstorm spatial mode EOF1 include the location and the strength of Northwest Pacific subtropical high. In the same way, the Northern Hemisphere polar vortex possibly has a close connection with Shaanxi thunderstorm.     

Change of digestive physiology in sea cucumber <Emphasis Type="Italic">Apostichopus japonicus</Emphasis> (Selenka) induced by corn kernels meal and soybean meal in diets

The present study was conducted to determine the change of digestive physiology in sea cucumber Apostichopus japonicus(Selenka) induced by corn kernels meal and soybean meal in diets. Four experimental diets were tested, in which Sargassum thunbergii was proportionally replaced by the mixture of corn kernels meal and soybean meal. The growth performance, body composition and intestinal digestive enzyme activities in A. japonicus fed these 4 diets were examined. Results showed that the sea cucumber exhibited the maximum growth rate when 20% of S. thunbergii in the diet was replaced by corn kernels meal and soybean meal, while 40% of S. thunbergii in the diet can be replaced by the mixture of corn kernels meal and soybean meal without adversely affecting growth performance of A. japonicus. The activities of intestinal trypsin and amylase in A. japonicus can be significantly altered by corn kernels meal and soybean meal in diets. Trypsin activity in the intestine of A. japonicus significantly increased in the treatment groups compared to the control, suggesting that the supplement of corn kernels meal and soybean meal in the diets might increase the intestinal trypsin activity of A. japonicus. However, amylase activity in the intestine of A. japonicus remarkably decreased with the increasing replacement level of S. thunbergii by the mixture of corn kernels meal and soybean meal, suggesting that supplement of corn kernels meal and soybean meal in the diets might decrease the intestinal amylase activity of A. japonicus.     

Study of 3D Geological Modeling Based on Aeromagnetic Data

With the increasing difficulty of finding the shallow surface deposit and the increasing depth of resources exploration, three-dimensional modeling technology is more apparent in deep prospecting, and its accuracy directly determines the cognitive degree of geological body and metallogenic condition. For this, we put forward a set of the extraction technology of abnormal information combined with aeromagnetic data processing with three-dimensional geological modeling. Inversing the selected profile of the study area and obtaining each profile geological model, we built three-dimensional geological model of geological units by the method of profile linked, using undulating terrain three-dimensional block magnetic field forward techniques to model the three-dimensional geological model of the whole area, and obtained the forward modeling results of the whole three-dimensional geological model and the geological unit. After the comparative analysis with the test result, adding reasonable geological constraints and revising model, through adjusting for many times, we made the model maximum close to the actual situation. The model can well reflect the geological information and make minimum fitting error of observations and theoretical field, with which geologists can use the most of their experience and get more regional geological understanding. Using the thought of main block and secondary block to subdivision modeling of geological body, on the condition of ensuring the accuracy of model, the number of the total model block decreased and the multi-window and multi-geological body parallel computing method were used to improve the modeling speed, effectively solve the limitation problem of the model complexity in the process of the three-dimensional inversion modeling method, and easily form complex and different sizes three-dimensional geological model. We applied this method to the Hubei Daye area, constructed the three-dimensional geological model of Daye Iron Mine, and verified the feasibility and rationality of this method.