Application of the Gravity Method to the Iron Ore Exploration in Eastern Hebei Province

The nation-wide iron ore exploration is primarily based on aeromagnetic survey,based upon which a series of ground follow-up and drilling examination were carried out,and then reconnaissance and detailed investigation and exploration were fulfilled.However,for some large.

SYNTHESIS AND APPLICATION OF NANOPARTICLES BY A HIGH GRAVITY METHOD

Fast chemical reactions involved in nanomaterials synthesis, polymerization, special chemicals production, reactive absorption, etc., are often difficult to control in terms of product quality, process efficiency and production consistency. After a theoretical analysis on such processes based on chemical reaction engineering fundamentals, an idea to intensify micromixing (mixing on the molecular scale) and mass transfer and therefore to control the process ideally was proposed. By experimental investigations of mass transfer and micromixing characteristics in the Rotating Packed Bed (RPB, or 'HIGEE' device), we achieved unique intense micromixing. This led us to the invention of using RPB as a reactor for the fabrication of nanoparticles (Chen et al., 2000).

An iterative Wiener filtering method based on the gravity gradient invariants

How to deal with colored noises of GOCE （Gravity field and steady - state Ocean Circulation Explorer） satellite has been the key to data processing. This paper focused on colored noises of GOCE gradient data and the frequency spectrum analysis. According to the analysis results, gravity field model of the optima] degrees 90-240 is given, which is recovered by COCE gradient data. This paper presents an iterative Wiener filtering method based on the gravity gradient invariants. By this method a degree-220 model was calculated from GOCE SGG （Satellite Gravity Gradient） data. The degrees above 90 of ITG2010 were taken as the prior gravity field model, replacing the low degree gravity field model calculated by GOCE orbit data. GOCE gradient colored noises was processed by Wiener filtering. Finally by Wiener filtering iterative calculation, the gravity field model was restored by space-wise harmonic analysis method. The results show that the model＇s accuracy matched well with the ESA＇s （European Space Agency） results by using the same data,

A statistical method for assessment of the existing correlations of hydrate forming conditions

Hydrate formation in the oil and gas industries has been a serious problem for a long time. It may cause many difficulties for instance in gas pipelines blockages. In order to determine the hydrate forming condition, gas gravity method has been used. Several correlations have been proposed based on gas gravity method. Checking the accuracy of the applied correlations is important. In this paper, the leverage approach is used for this purpose. Leverage approach is a statistical method for detection outliers which identifies the applicability domain （AD） of hydrate data predicting correlations and the quality of the existing data. Moreover, the Williams plot is sketched, which is a graphical depiction for determination of the doubtful points. The obtained results showed the existing correlations are all statistically correct and valid to predict hydrate formation temperature, just one data point is out of the applicability domains, and none of the experimental data can be chosen as outliers.

Trends in gravity changes from 2009 to 2013 derived from ground-based gravimetry and GRACE data in North China

North China is a key region for studying geophysical progress. In this study, ground-based and Gravity Recovery and Climate Experiment（GRACE） gravity data from 2009 to 2013 are used to calculate the gravity change rate（GCR） using the polynomial fitting method. In general, the study area was divided into the Shanxi rift, Jing-Jin-Ji（Beijing-Tianjin-Hebei Province）, and Bohai Bay Basin（BBB） regions. Results of the distribution of the GCR determined from ground-based gravimetry show that the GCR appears to be ＂negativepositive-negative＂ from west to east, which indicates that different geophysical mechanisms are involved in the tectonic activities of these regions. However, GRACE solutions are conducted over a larger spatial scale and are able to show a difference between southern and northern areas and a mass redistribution of land water storage.

Numerical simulation on the stability of rock slope based on an improved SPH Method

The presence of random fissures has a great impact on rock slope stability.To investigate the failure modes and stability of rock slopes containing different types of pre-existing fissures,the fracture mark ξ was introduced to improve the kernel function in the traditional smoothed particle dynamics(SPH) method,and a novel numerical method,the improved kernel of smoothed particle hydrodynamics(IKSPH),was proposed to realise the microscopic damage characteristics of particles.The ‘random fissure generating method' has been proposed for random fissure generation,and the gravity increase method has been embedded into the IKSPH program,thereby realising the stability analysis of rock slopes considering crack propagation processes.A typical steep rock slope is taken as a numerical simulation example considering the random distributions of preexisting fissures,and its failure modes as well as the stability under different conditions were simulated.The results show that the failure processes of the rock slope contain propagations of microcracks and then macrocrack penetrations.When the fissure length is short,shallow collapse failure modes can be observed;when the fissure length is long,the deep layer slide occurs,and the slope stability decreases with an increase in fissure length.The micro and macrocrack surfaces are basically consistent with pre-existing fissure angles,and the safety factor is the least at a fissure angle of 30°.The greater the fissure density,the greater the number of macrocracks,and the stability decreases with an increase in the number of pre-existing fissures.The research results can provide some references for disaster protection and understanding the failure laws of rock slopes.Meanwhile,combining the geological survey results with the numerical simulations and developing a high-performance IKSPH program will be a future research direction.

Reconnaissance investigation of geothermal resources in parts of the Middle Benue Trough, Nigeria using remote sensing and geophysical methods

In Nigeria,the basement complex and the sedimentary basins house many thermal springs which are physical manifestations of geothermal energy.However,there are difficulties in accessing the sustain-ability of these resources due to ethical and security issues as well as limited data in Nigeria.Thus,identifying the precise location,temperature,and energy potential on a large scale has been a major drawback.This paper is the preliminary investigation of geothermal potential in parts of the Middle Benue Trough using satellite imagery,geology,regional gravity,and high-resolution aeromagnetic data.Landsat 8 scene was used to estimate the Land Surface Temperature(LST)in ArcGIS^(TM).Selected sites were classified as very low,low,moderate,and high LST.The intermediate and high classes happen to be possible geothermal zones,and they occupy 49% of the study area(38,077 km^(2)).The Riverline was superimposed on the LST,and the high-temperature sites were located by the identification tool.Streams/river data overlapped on the selected sites were regarded as thermal/warm springs.Remarkably,the LST results show lower temperatures(<36℃)at the famous thermal springs(Awe and Wukari)than some unknown rivers/streams found in Kwande(38℃),Ussa,(38℃),Gwer East(37℃),Yola Cross and Ogoja(36℃).Furthermore,the geophysical datasets,regional gravity,and high-resolution aeromagnetic data were interpolated to delineate the subsurface features associated with geothermal manifestations.The four layers from the LST were further evaluated using the geophysical approach.Gravity and mag-netic values revealed variations that could be linked to geothermal alterations.The correlation of the geophysical anomalies and LST with the geology of the study area uncovers essential information on energy potentials.Therefore,further investigation is required to estimate the depth of the causative body,the geothermal gradients,and the reservoir volumes.

Gravity changes and surface deformations due to faults with different geometry

Based on the formulae of the gravity changes and surface deformations raised by the dislocation of a point source,the gravity changes and deformations caused by the dislocations of fault with arbitrary geometry are computed by using numerical method. The results show that both of the dislocation and the geometry of the fault plane are the basic elements that determine the gravity and deformation effects. Gravity changes, vertical deformations and apparent vertical deformations induced by the dislocation are alike in their characteristic patterns. The similarities and differences of these patterns provide us a probability in acquiring the gravity and deformation anomalies due to faulting from the observed data. Thus the geometric and kinematic features of the earthquake-generating faults can be appropriately distinguished and evaluated.

Initial estimation of hydrate formation temperature of sweet natural gases based on new empirical correlation

Production,processing and transportation of natural gases can be significantly affected by clathrate hydrates.Knowing the gas analysis is crucial to predict the right conditions for hydrate formation.Nevertheless,Katz gas gravity method can be used for initial estimation of hydrate formation temperature （HFT） under the circumstances of indeterminate gas composition.So far several correlations have been proposed for gas gravity method,in which the most accurate and reliable one has belonged to Bahadori and Vuthaluru.The main objective of this study is to present a simple and yet accurate correlation for fast prediction of sweet natural gases HFT based on the fit to Katz gravity chart.By reviewing the error analysis results,one can discover that the new proposed correlation has the best estimation capability among the widely accepted existing correlations within the investigated range.

Study on Location of Wuhan Steel Logistics Distribution Center

This paper studies the location of Wuhan steel logistics distribution center. First of all, according to Wuhan Iron and Steel Plant sales in Hunan Province and the relative position of the city, the transport costs are calculated from Wuhan Iron and Steel Plant to the demand point. We further analyze the necessity of establishing steel logistics distribution center, using the precise center of gravity to determine the actual location of the distribution center. After the establishment of distribution center, the total freight is reduced by 15.46 million yuan from Wuhan Iron and Steel Plant to each city in Hunan province via distribution center each year. The results of this paper can provide theoretical basis for the logistics node planning of related enterprises.

Genetic model and exploration target area of geothermal resources in Hongtang Area, Xiamen, China

The geothermal resources in Fujian Province are mainly hydrothermal resources of medium-low temperature.To better understand the whole process and conditions of heat control in the middle and deep crust,this study focuses on the analysis of heat accumulation model in Hongtang Area of Xiamen,and the main conditions of the model such as faults and sags are explored and interpreted in detail by using gravity and wide-field electromagnetic methods.4 main faults(F33,F2,F12 and HT-F1)and 10 secondary faults(HT-F2,HT-F3,HT-F4,HT-F5,HT-F6,HT-F7,HT-F8,HT-F9,HT-F10 and HT-F11)were inferred,and the distribution range of sags was delineated.The convective geothermal system is composed of four components:Heat source,geothermal reservoir,heat-conductive fault and heat retaining cover,which form a quaternary heat accumulation model.According to the model,the intersection of the main faults F12,HTF1 and F33 can be delineated as the primary target area of geothermal exploration,while the intersection of the secondary faults(F12 and HT-F6;F12 and HT-F2;HT-F9,HT-F10 and F12;F12 and HT-F11;F33 and HT-F3;HT-F8 and HT-F3;HT-F2,HT-F10 and HT-F1)can be delineated as the secondary target area.Borehole DR01,which is located in the primary target area,shows that the water temperature increases from fast to slow in the depth range of 0–500 m,and stays at 36℃below 500 m.The reliability of the heat accumulation model and the target area was tested via geothermal boreholes,which is of great significance to the exploitation and utilization of geothermal resources in Hongtang Area of Xiamen.

New Technology Going Up from the GPS Measurements,Known W_(0) and Its Possible Utilization in Praxis

New height precise Earth Geopotential Model EGM08 made it possible to develop the value of the geoidal geopotential W0. This value is independent on Earth’s tides and others disturbances, therefore it can be used as basic quantity for many applications. Value W0 represents mean sea surface. W0 was developed from data of satellite altimetry which monitores actual ocean’s surface. This value is one of the four fundamental geodetic constants. This value has been accepted worldwide and is included to the International Earth Rotation and Reference Systems Service Conventions (IERS Conventions) 2003, 2007. This value defines in principle parameters of level ellipsoid which best fit to the surface defined by W0. The body of this level ellipsoid produces normal gravity. We developed other important parameters for determination of the density deviations (VTT technology), i.e. values of normal gravity ge at the equator and gp at the pole on the elipsoid E0 and the value of parameter β. All parameters above used for development of VTT technology are supplied by GPS/leveling data that enable to create so-called density deviation maps at any place in the World. In comparison with gravity anomalies, the density deviations represent more precise density anomalous places in the Earth’s crust. A construction of density deviation map is applied at two from geologically different regions—the Western Carpathians and the Central African Rifts.

A rapid compensation method for launch data of long-range rockets under influence of the Earth＇s disturbing gravity field

Regarding the rapid compensation of the influence of the Earth＇ s disturbing gravity field upon trajectory calculation,the key point lies in how to derive the analytical solutions to the partial derivatives of the state of burnout point with respect to the launch data.In view of this,this paper mainly expounds on two issues：one is based on the approximate analytical solution to the motion equation for the vacuum flight section of a long-range rocket,deriving the analytical solutions to the partial derivatives of the state of burnout point with respect to the changing rate of the finalstage pitch program;the other is based on the initial positioning and orientation error propagation mechanism,proposing the analytical calculation formula for the partial derivatives of the state of burnout point with respect to the launch azimuth.The calculation results of correction data are simulated and verified under different circumstances.The simulation results are as follows：（1） the accuracy of approximation between the analytical solutions and the results attained via the difference method is higher than 90%,and the ratio of calculation time between them is lower than 0.2%,thus demonstrating the accuracy of calculation of data corrections and advantages in calculation speed;（2） after the analytical solutions are compensated,the longitudinal landing deviation of the rocket is less than 20 m and the lateral landing deviation of the rocket is less than 10 m,demonstrating that the corrected data can meet the requirements for the hit accuracy of a long-range rocket.