Feasibility of Re-injecting the Production Effluent from Alkali–Surfactant–Polymer Flooding Systems Back into a Reservoir to Further Improve Oil Recovery

Natural Resources Research - Alkali–surfactant–polymer (ASP)-produced effluent contains polymer, alkali and surfactant, and it has higher content of suspended oil droplets and suspended...     

场地土液化引起的地下管道上浮反应研究

本文利用虚功原理,建立了场地土液化引起的地下管道的上浮反应分析模型,用弹性地基梁来模拟地下管道,并考虑了土的非线性约束作用、管道的初始变形、液化区长度、管道的初始轴力等的影响。采用非线性增量有限元法,对场地土液化引起的地下管道的上浮反应进行了研究,给出了部分计算结果。     

Distance law and formation of satellite systems

In the solar system satellite systems of Jupiter, Saturn and Uranus are typical ones. The distribution of the semi-major axis of satellite orbits in each system may be expressed by an empirical formula corresponding to the Titius-Bode law. We found that it can be written as a_n = B′ · Bⁿ, where B′ and B are constants. Values of B′ and B depend on formation conditions of each system. Satellites should be formed in the gas-satellitesimal disk around a planet and by aggregation of satellitesimals. The gas is the major component in the disk and its damping effect must play an important role in the process of aggregation of satellitesimals. It may be proved that radial small perturbation in the disk can cause the gravitational instability and the formation of gaseous rings with increased density, where satellitesimals can easy aggregat into satellites.     

SOME NEW UNDERSTANDINGS OF LAND-SURFACE PROCESSES IN ARID AREA FROM THE HEIFE

The survey for the HEIFE(Atmosphere-Land Surface Processes Experiment at Heihe RiverBasin,Western China)is given in the paper.The following basic subjects for land-surface process-es in arid areas are studied:(1)the general characteristics of the energy budget on ground surfacein arid areas;(2)the parameterization of the land surface processes;(3)the interaction betweenoasis and its desert circumstances,a special phenomenon in arid areas.The analysis shows that thesensible heat flux in the surface energy budget is in the majority,and the latent heat flux may beneglected.The influence of atmospheric stratification stability on the turbulent transfer of energyand substance must be considered in parameterization of land surface processes in arid areas.The“cold island effect”phenomenon in oasis and the“humidity inversion”phenomenon in desert nearoasis are the result of the interaction between them.The results would improve the understandingof land surface processes in arid areas.     

Application of Astronomic Time-latitude Residuals in Earthquake Prediction

After the earthquake (Ms = 6.1) occurred in Luquan county of Yunnan province on April 18, 1985, the relationship between major earthquakes and astronomical time-latitude residuals (ATLR) of a photoelectric astrolabe in Yunnan Observatory was analyzed. ATLR are the rest after deducting the effects of Earth’s whole motion from the observations of time and latitude. It was found that there appeared the anomalies of the ATLR before earthquakes which happened in and around Yunnan, a seismic active region. The reason of the anomalies is possibly from change of the plumb line due to the motion of the groundmass before earthquakes. Afterwards, using studies of the anomalous characters and laws of ATLR, we tried to provide the warning information prior to the occurrence of a few major earthquakes in the region. The significant synchronous anomalies of ATLR of the observatory appeared before the earthquake of magnitude 6.2 in Dayao county of Yunnan province, on July 21, 2003. It has been again verified that the anomalies possibly provide the prediction information for strong earthquakes around the observatory.     

Catastrophe of Coronal Magnetic Flux Ropes Caused by Photospheric Motions

Using a 2.5-D, time-dependent ideal MHD model in Cartesian coordinates, we carried out numerical simulations to investigate the equilibrium and evolution properties of a magnetic configuration that consists of a coronal magnetic flux rope and a partly open photospheric background field, which is equivalent to that produced by a two-patch magnetic source on the photospheric surface. The axial and annular magnetic fluxes of the flux rope are given and fixed. The global magnetic configuration evolves in response to three types of changes of the background field: decreasing of the distance between the two sources, shrinking of the size of each source, and increasing of the shear in the closed component of the background field. As a result, the geometrical parameters of the flux rope, i.e. the height of the rope axis, the half-width of the rope and the length of the vertical current sheet below the rope, change due to the variation of the background field. It is shown that for a given coronal magnetic flux rope in a partly open background field, the variation of the geometrical parameters of the flux rope displays a catastrophic behavior, namely, there exists a critical point for each case, at which an infinitesimal change of the background field leads to a loss of equilibrium, and thus a jump of the flux rope. The implication of such a catastrophe in solar active phenomena is briefly discussed.     

Local-scale patterns of genetic variation in coexisting floating-leaved Nymphoides peltata and submerged Myriophyllum spicatum in Donghu Lake

Journal of Oceanology and Limnology - Coexisting floating-leaved and submerged plants experience similar environmental changes but may evolve different patterns of genetic variation. To compare...     

Extraction of basic trends of urban expansion in China over past 40 years from satellite images

If urban sprawl is to be avoided in China in the next ten years, it is not only crucial to understand the overall history, current status, and future trends of urban expansion there, but also these differences, and this is presently lacking. In this study, remotely sensed images with approximately 30 m spatial resolution were used to quantitatively assess the spatial and temporal patterns of urban expansion of 60 Chinese cities(1973–2013). Urban-expansion-process curves of the cities studied were drawn using annual expansion area as an indicator. Curve similarity analysis generated four basic process modes of urban expansion in China. These included cities that: 1) peaked around 2004 and then decelerated; 2) peaked around 2010 and then decelerated; 3) showed sustained acceleration, and 4) showed continued deceleration. Four basic process modes represented cities under different levels of development stage. Geographic location was found to be the most related characteristic to urban expansion process. Regional development policies at the national level in each region also showed highly temporal consistency with fluctuation characteristics of urban expansion process. Urban characteristic such as population size and administrative level were not found to be significantly related to urban expansion-process modes. Understanding the basic process-mode categories well is extremely important for future regional-balance planning and development of macroeconomic policies.     

Livelihood changes and evolution of upland ethnic communities driven by tourism: a case study in Guizhou Province,southwest China

As an effective livelihood approach to alleviate poverty without rural population migration, ethnic tourism has become the primary choice of economic development in ethnic areas worldwide in addition to traditional livelihood approaches. This article applies the theories of livelihood to study the community evolution driven by tourism livelihood and examine three mountainous tourism communities in different stages of tourist area life cycle. Drawing on the methods of GIS spatial analysis, semi-structured interviews and questionnaires, this article proposes a sustainable livelihood framework for ethnic tourism to explore the evolution of ethnic tourism communities by identifying changes in livelihood assets (natural, financial, social, cultural and human capitals) in the process of tourism development. The results show that the development of ethnic tourism has led to changes in the increase of building land, and the diversification of land use functions with a trend of shifting from meeting local villagers' living needs to satisfying tourists, income composition and uneven distribution of tourism income spatially. Ethnic tourism also led to the deterioration of traditional social management structure, collapse of neighboring relationship, the over- commercialization and staged authenticity of ethnic culture, as well as the gradual vanish of agricultural knowledge with a trend of increasing modern business knowledge and higher education. In addition, these changes, involving livelihood assets from natural, economic, human, social and cultural aspects are interrelated and interactive, which form new evolution characters of ethnic community. This study reveals the conflicts over livelihood approaches which have formed new vulnerabilities to impact on sustainable evolution of ethnic communities. This research provides implications for achieving the sustainable development of ethnic communities with the driving force of tourism livelihood.     

顶板诱导崩落模式选择时变数值分析

顶板诱导崩落是一种新的空区处理技术,其实施效果与诱导崩落施工路径、方法和顺序有关,同时矿岩体作为一种弹塑性体,具有非线性时变力学特征。运用时变力学的基本理论,建立了顶板诱导崩落的时变力学有限元基本方程。针对大厂铜坑矿92号矿体试验采场的地质特征,构建了顶板诱导崩落的时变力学有限元模型,采用多步骤开挖模拟两种不同顶板诱导崩落模式,研究两种不同工序的顶板塑性区发展、东西预裂与崩顶硐室的位移及其安全系数,分析了其对采场的综合效应。结果表明,先预裂后崩顶的顶板诱导崩落模式有利于顶板崩落诱导,并综合考虑诱导崩落效果与作业安全,建议采用先预裂爆破后强制崩顶的微差爆破一次成型工艺。