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Optimization of Center of Gravity Position and Anti-Wave Plate Angle of Amphibious Unmanned Vehicle Based on Orthogonal Experimental Method
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作者 Deyong Shang Xi Zhang +3 位作者 Fengqi Liang Chunde Zhai Hang Yang Yanqi Niu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期2027-2041,共15页
When the amphibious vehicle navigates in water,the angle of the anti-wave plate and the position of the center of gravity greatly influence the navigation characteristics.In the relevant research on reducing the navig... When the amphibious vehicle navigates in water,the angle of the anti-wave plate and the position of the center of gravity greatly influence the navigation characteristics.In the relevant research on reducing the navigation resistance of amphibious vehicles by adjusting the angle of the anti-wave plate,there is a lack of scientific selection of parameters and reasonable research of simulation results by using mathematical methods,and the influence of the center of gravity position on navigation characteristics is not considered at the same time.To study the influence of the combinations of the angle of the anti-wave plate and the position of the center of gravity on the resistance reduction characteristics,a numerical calculation model of the amphibious unmanned vehicle was established by using the theory of computational fluid dynamics,and the experimental data verified the correctness of the numerical model.Based on this numerical model,the navigation characteristics of the amphibious unmanned vehicle were studied when the center of gravity was located at different positions,and the orthogonal experimental design method was used to optimize the parameters of the angle of the anti-wave plate and the position of the center of gravity.The results show that through the parameter optimization analysis based on the orthogonal experimental method,the combination of the optimal angle of the anti-wave plate and the position of the center of gravity is obtained.And the numerical simulation result of resistance is consistent with the predicted optimal solution.Compared with the maximum navigational resistance,the parameter optimization reduces the navigational resistance of the amphibious unmanned vehicle by 24%. 展开更多
关键词 Amphibious unmanned vehicle orthogonal experimental design anti-wave plate center of gravity resistance characteristic
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Applicability of Gravity Separation Method on the Ashashire Gold Ore Deposit from Benishangul Gumuz Region, Western Ethiopia
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作者 Misganu Kabeta Mulugeta Sisay Cheru Goitom Gebreyohannes Berhe 《International Journal of Nonferrous Metallurgy》 2024年第2期21-31,共11页
The study was conducted to determine the applicability of gravity separation method on the Ashashire gold ore deposit Benishangul gumuz region, western Ethiopia. The Ashashire composite was produced to provide suffici... The study was conducted to determine the applicability of gravity separation method on the Ashashire gold ore deposit Benishangul gumuz region, western Ethiopia. The Ashashire composite was produced to provide sufficient mass for this study and experiment, including sample preparation, mineralogical analysis of gold and associated elements, gravity concentration, and data interpretation and analysis. During the study, a grind optimization was conducted on the composites sample with varying grind size to evaluate the effect of grind size on gold recovery. The ore was moderately ground to the standard grind size of 80%, passing 106 µm, 75 µm, 53 µm and this nominal size was selected for the preliminary assessment for concentration optimization for this deposit. The gravity testing comprised three-stage concentration using Knelson concentrator. High recovery of gold from the gravity concentrates was achieved from the second gravity concentration. Based on the laboratory experimental result analysis, a grind size of P80 75 µm is selected as optimal size for the Ashashire gold deposit. Increasing the grind size from P80 of 75 µm to 106 µm decreases the recovery rate from 75% to 54%, or decreasing the grind size from P80 of 75 µm to 53 µm decreases the gold recovery rate to 37%. The native gold grain in the ores is mostly associated with quartz and fine gold is closely associated with pyrite. According to analysis of the fire assay, chemical, and mineralogical data, only gold and telluride is commercially valuable elements in the ores. Predominantly gold was occurred in the native form of Au-Te. The sample subjected to gravity separation assayed about 2.6 g/t Au. 展开更多
关键词 ORE GANGUE Ashashire gravity method Gold TELLURIDE Concentration Knelson
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From Sustainability to Gravity: The Research Path of an Engineer
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作者 Nicolas Vantis 《Philosophy Study》 2024年第2期81-90,共10页
My career as a scientist has been a passionate pursuit of knowledge,objective knowledge devoid of ideology,that could prove useful in understanding and transforming the world.As an engineer,I aimed to produce planning... My career as a scientist has been a passionate pursuit of knowledge,objective knowledge devoid of ideology,that could prove useful in understanding and transforming the world.As an engineer,I aimed to produce planning solutions which would be economically feasible,technically viable,and socially acceptable.Disappointed by the ineffectiveness of methodology and planning initiatives to attain sustainability,I turned to the history of science to find answers,and finally to physics,searching for an explanation of gravity.I traced a path from social to natural sciences.My attachment to my values and ideals,my commitment to my goals costed me dearly.It led me to quit applied research,to move to a desert island in the Atlantic Ocean,to be consumed for years by a Galileo-like obsession.“I must create a system,or be enslaved by another man’s.I will not reason and compare:my business is to create”(Blake,2002,p.210),has been my life’s motto.Have I succeeded in my self-appointed task or have I just wasted valuable years of creative research building sand castles?I don’t have the answer to this question.What I know for sure is that I do not regret hanging to what I thought to be right. 展开更多
关键词 gravity gravitational waves SUSTAINABILITY critique of scientific method
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Selecting the optimum location of the corner using gravity gradient method
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作者 孙鹏飞 吴燕冈 +2 位作者 杨春成 韩兆红 范美宁 《Applied Geophysics》 SCIE CSCD 2011年第4期269-276,370,共9页
The conventional gravity gradient method to plot the geologic body location is fuzzy. When the depth is large and the geologic body is small, the Vzz and Vzx derivative errors are also large. We describe that using th... The conventional gravity gradient method to plot the geologic body location is fuzzy. When the depth is large and the geologic body is small, the Vzz and Vzx derivative errors are also large. We describe that using the status distinguishing factor to optimally determine the comer location is more accurate than the conventional higher-order derivative method. Thus, a better small geologic body and fault resolution is obtained by using the gravity gradient method and trial theoretical model calculation. The actual data is better processed, providing a better basis for prospecting and determination of subsurface geologic structure. 展开更多
关键词 high-order gravity derivative gravity gradient method status distinzuishinz factor
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Contraceptive Experiences of Women of Procreation Age Who Attended Two HealthCenters in the City of Abidjan (Cote d’Ivoire)
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作者 Essis Esme Marie Laure Koffi Kouassi Benjamin +6 位作者 Manouan N’guetta Mathilde Coulibaly-Koné Soltié Aminata Bamba Iba Kpebo Djoukou Olga Denise Konan Loukou Leandres Aka Joseph Ndola Prata 《Health》 CAS 2023年第1期1-19,共19页
Introduction: Maternal mortality, which is estimated at 614 deaths per 100,000 births in C&#244;te d’Ivoire, is associated with a low national contraceptive prevalence rate of 13.9%. In this study, we are interes... Introduction: Maternal mortality, which is estimated at 614 deaths per 100,000 births in C&#244;te d’Ivoire, is associated with a low national contraceptive prevalence rate of 13.9%. In this study, we are interested in the contraceptive experiences of women who attend health centers to estimate their rate of contraceptive use and to assess the factors involved in the use of modern contraceptive methods among women of childbearing age who are exposed to the risk of pregnancy. Method: A descriptive cross-sectional study was conducted from December 2018 to September 2019 among 423 women, who attended two health centers in Abidjan. A bivariate analysis identified factors associated with contraceptive use by these women. A descriptive analysis determined the means for the quantitative variables and the frequencies and percentages of qualitative variables. Interpretation of results was based on significance (α = 5%, 95% CI). Results: Contraceptive prevalence was 37%. There was a significant relationship between contraceptive use and the socio-demographic and reproductive characteristics of women (p Conclusion: Women who were over 35 years age, uneducated, primary school graduates, housewives, unemployed, in the informal sector, Muslims, nulliparous, and lacking information and decision-making power were less likely to use modern contraceptive methods. They are the target population for strategic interventions to improve contraceptive prevalence. 展开更多
关键词 Use Contraceptive methods WOMEN Health centers Côte d’Ivoire AFRICA
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Sensitivity analysis of factors affecting gravity dam anti-sliding stability along a foundation surface using Sobol method
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作者 Bo Xu Shi-da Wang 《Water Science and Engineering》 EI CAS CSCD 2023年第4期399-407,共9页
The anti-sliding stability of a gravity dam along its foundation surface is a key problem in the design of gravity dams.In this study,a sensitivity analysis framework was proposed for investigating the factors affecti... The anti-sliding stability of a gravity dam along its foundation surface is a key problem in the design of gravity dams.In this study,a sensitivity analysis framework was proposed for investigating the factors affecting gravity dam anti-sliding stability along the foundation surface.According to the design specifications,the loads and factors affecting the stability of a gravity dam were comprehensively selected.Afterwards,the sensitivity of the factors was preliminarily analyzed using the Sobol method with Latin hypercube sampling.Then,the results of the sensitivity analysis were verified with those obtained using the Garson method.Finally,the effects of different sampling methods,probability distribution types of factor samples,and ranges of factor values on the analysis results were evaluated.A case study of a typical gravity dam in Yunnan Province of China showed that the dominant factors affecting the gravity dam anti-sliding stability were the anti-shear cohesion,upstream and downstream water levels,anti-shear friction coefficient,uplift pressure reduction coefficient,concrete density,and silt height.Choice of sampling methods showed no significant effect,but the probability distribution type and the range of factor values greatly affected the analysis results.Therefore,these two elements should be sufficiently considered to improve the reliability of the dam anti-sliding stability analysis. 展开更多
关键词 gravity dam Anti-sliding stability Sensitivity analysis Sobol method Latin hypercube sampling
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Analysis and Study on Spatial Gravity Center of PM_(2.5) and Population Scale
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作者 Chaoqun LIU 《Meteorological and Environmental Research》 CAS 2023年第5期11-13,共3页
With the rapid development of urbanization construction in China,population and industries are rapidly gathering in cities,bringing about economic development and also causing a large number of environmental problems,... With the rapid development of urbanization construction in China,population and industries are rapidly gathering in cities,bringing about economic development and also causing a large number of environmental problems,among which PM_(2.5) is the most concerned.In this paper,a spatial gravity center model was used to systematically analyze the spatiotemporal distribution characteristics of PM_(2.5) and population scale in China from 1999 to 2016.Conclusions were as below:(1)there were significant regional differences in PM_(2.5) pollution from 1999 to 2016,characterized by a spatial distribution of"high in the north and low in the south,and high in the inland and low in the coastal areas".(2)Nationwide,there was a significant spatial mismatch between the gravity center of PM_(2.5) pollution and the gravity center of population scale,with the two centers showing a trend of reverse dislocation development. 展开更多
关键词 PM_(2.5) Population scale gravity center model Spatial mismatch
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Analysis of Urbanization Based on Center-of-gravity Movement and Characteristics in Songhua River Basin of China and its Southern Source Sub-basin between 1990 and 2010 被引量:1
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作者 FU Xiao SHEN Yuan +2 位作者 DONG Rencai DENG Hongbing WU Gang 《Chinese Geographical Science》 SCIE CSCD 2016年第1期117-128,共12页
Urbanization in modern times led to a series of development strategies that brought new opportunities in China. Rapid urbanization caused severe stress to the ecosystems and the environment. Using the center-of-gravit... Urbanization in modern times led to a series of development strategies that brought new opportunities in China. Rapid urbanization caused severe stress to the ecosystems and the environment. Using the center-of-gravity(COG) method and parameters such as population, economy, and land, we studied the urbanization pattern in Songhua River Basin and its southern source sub-basin from 1990 to 2010. Urbanization was analyzed based on the COG position, eccentric distance, movement direction of COG, and distance of COG movement. Various characteristics of urbanization in the southern source sub-basin of the Songhua River were explained in relation to the whole Songhua River Basin. Urbanization in the southern source sub-basin of the Songhua River is balanced, relatively advanced, and stable compared to the whole Songhua River Basin. The average eccentric distance between the urbanization COGs in the Songhua River′s south source basin indicated rapid expansion of land urbanization during the span of this study. A basic pattern of urbanization COG in the whole Songhua Basin was observed, but there existed differences among the three aspects of urbanization process. Land urbanization is still in its active stage, so future studies should focus on analysis of such urbanization trends. 展开更多
关键词 URBANIZATION Songhua River Basin southern source sub-basin of Songhua River center of gravity method eccentric distance
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Application of the Gravity Method to the Iron Ore Exploration in Eastern Hebei Province 被引量:5
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作者 ZHANG Guoli ZHAO Gengxin +3 位作者 HE Fuqing SU Yongjun TENG Fei KUANG Haiyang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2015年第6期2097-2098,共2页
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... 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. 展开更多
关键词 Application of the gravity method to the Iron Ore Exploration in Eastern Hebei Province
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Quantum Chemical Studies on Proteins in the Reaction Center of Rhodobacter sphaeroides 被引量:1
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作者 徐红 马淑华 +3 位作者 沈玲玲 张晓东 张兴康 张启元 《Acta Botanica Sinica》 CSCD 2001年第6期565-570,共6页
The electronic structure of protein chains L and M in photosynthetic reaction center (PRC) of Rhodobacter sphaeroides (Van Niel) Imhoff, Truper et Pfennig) was studied by using the Overlapping Dimer Approximation meth... The electronic structure of protein chains L and M in photosynthetic reaction center (PRC) of Rhodobacter sphaeroides (Van Niel) Imhoff, Truper et Pfennig) was studied by using the Overlapping Dimer Approximation method and the Extended Negative Factor Counter method at ab initio level. The result indicated that: (1) Amino acid residues, the molecular orbitals of which composed the main components of frontier orbitals of protein chain L (M), are located at the random coil areas of chain L (alpha helix areas of chain M). Since the random coil is flexible and more easy to change its conformation in the electron transfer process and to reduce the energy of the system, and the structure of the alpha helix is reletively stable, this difference might be one of the causes for the electron transfer in photosynthetic reaction center (PRC) only takes place along the L branch. (2) The His residues which axially coordinated to the 'special pair' P and accessory chlorophyll molecules (ABChls) are essentially important for the E-LUMO levels of P and ABChl. But, the corresponding molecular orbitals of these His residues do not appear in the composition of frontier orbitals of protein chains. It means that the interaction between pigment molecules and protein chains do not influence the contribution to the frontier orbitals of protein chains explicitly, but influences the corresponding E-LUMO levels significantly. 展开更多
关键词 photosynthetic reaction center Rhodobacter sphaeroides electronic structure of protein ab initio Extended Negative Factor Counter method (ENFC)
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Extrapolated Tikhonov method and inversion of 3D density images of gravity data
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作者 王祝文 许石 +1 位作者 刘银萍 刘菁华 《Applied Geophysics》 SCIE CSCD 2014年第2期139-148,252,共11页
Tikhonov regularization(TR) method has played a very important role in the gravity data and magnetic data process. In this paper, the Tikhonov regularization method with respect to the inversion of gravity data is d... Tikhonov regularization(TR) method has played a very important role in the gravity data and magnetic data process. In this paper, the Tikhonov regularization method with respect to the inversion of gravity data is discussed. and the extrapolated TR method(EXTR) is introduced to improve the fitting error. Furthermore, the effect of the parameters in the EXTR method on the fitting error, number of iterations, and inversion results are discussed in details. The computation results using a synthetic model with the same and different densities indicated that. compared with the TR method, the EXTR method not only achieves the a priori fitting error level set by the interpreter but also increases the fitting precision, although it increases the computation time and number of iterations. And the EXTR inversion results are more compact than the TR inversion results, which are more divergent. The range of the inversion data is closer to the default range of the model parameters, and the model features and default model density distribution agree well. 展开更多
关键词 gravity data inversion 3D inversion extrapolated Tikhonov regularization method extrapolated Tikhonov parameter selection
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METHOD TO CALCULATE BENDING CENTER AND STRESS INTENSITY FACTORS OF CRACKED CYLINDER UNDER SAINT_VENANT BENDING
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作者 汤任基 汤昕燕 《应用数学和力学》 EI CSCD 北大核心 2001年第1期71-78,共8页
Using the single crack solution and the regular solution of plane harmonic function, the problem of Saint_Venant bending of a cracked cylinder by a transverse force was reduced to solving two sets of integral equation... Using the single crack solution and the regular solution of plane harmonic function, the problem of Saint_Venant bending of a cracked cylinder by a transverse force was reduced to solving two sets of integral equations and its general solution was then obtained. Based on the obtained solution, a method to calculate the bending center and the stress intensity factors of the cracked cylinger whose cross_section is not thin_walled, but of small torsion rigidity is proposed. Some numerical examples are given. 展开更多
关键词 裂纹柱 SAint-VenAnt弯曲 弯曲中心 应力强度因
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Evolution of economic linkage network of the cities and counties on the northern slope of the Tianshan Mountains,China
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作者 YANG Zeyu ZHANG Shubao +4 位作者 LEI Jun ZHANG Xiaolei TONG Yanjun DUAN Zuliang FAN Liqin 《Regional Sustainability》 2023年第2期173-184,共12页
The exchanges between cities and counties in the northern slope economic belt of Tianshan Mountains(NSEBTM)are increasingly frequent and the economic linkages are increasingly close,but the spatial distribution of eco... The exchanges between cities and counties in the northern slope economic belt of Tianshan Mountains(NSEBTM)are increasingly frequent and the economic linkages are increasingly close,but the spatial distribution of economic development and linkages among the cities and counties within NSEBTM is uneven.Therefore,it is of great significance to study the evolution of spatial-temporal pattern of the economic linkage network of cities and counties on NSEBTM to promote the coordinated and integrated development of the regional economy on NSEBTM.In this study,we used the modified gravity model and social network analysis method to analyze the spatio-temporal evolution characteristics of the economic linkage network structure of cities and counties on NSEBTM in 2000,2010,and 2020.The results showed that the comprehensive development quality level of cities and counties on NSEBTM increased from 2000 to 2020,its growth rate also increased,and its gap between cities and counties continued expanding.Both the spatial distribution patterns of the comprehensive development quality level of cities and counties on NSEBTM in 2000 and 2010 were presented as“high in the middle and low at both ends”,while the spatial distribution pattern of 2020 was exhibited as“high value and low value staggered”.The total amount of external economic linkages of cities and counties on NSEBTM showed an obvious upward trend,and its gap between cities and counties continued expanding,presenting a pattern of“a strong middle section and weak ends”.The direction of economic linkages of NSEBTM existed obvious central orientation and geographical proximity.The density of economic linkage network of NSEBTM increased from 2000 to 2020,and the structure of economic linkage network changed from single-core structure centered with Urumqi City to multicore structure centered with Urumqi City,Karamay City,Shihezi City,and Changji City,shifting from unbalanced development to balanced development.In the future,we should accelerate the construction of urban agglomeration on NSEBTM,cultivate a modern Urumqi metropolitan area,improve comprehensive development quality of the cities and counties at the eastern and western ends,strengthen the intensity of economic linkages between cities and counties,optimize the economic linkage network,and promote the coordinated and integrated development of regional economy. 展开更多
关键词 Entropy method Economic linkages gravity model Network structure Social network analysis Northern slope economic belt of Tianshan Mountains China
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Evolvement Characteristics of Population and Economic Gravity Centers in Tarim River Basin,Uygur Autonomous Region of Xinjiang,China 被引量:6
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作者 WANG Yang CHEN Yaning LI Zhi 《Chinese Geographical Science》 SCIE CSCD 2013年第6期765-772,共8页
Using the data at the county levcl and the regional gravity center model, we calculated six key socio-economic gravity centers, namely population, GDP, output values of primary, secondary and tertiary industries, and ... Using the data at the county levcl and the regional gravity center model, we calculated six key socio-economic gravity centers, namely population, GDP, output values of primary, secondary and tertiary industries, and arable land area in the Tarim River Basin for each year from 1980 to 2009. We inspected the spatial dynamics of these centers and found that the gravity centers of population and economy evolved simultaneously. The disproportional growth between the population and the economy is also analyzed. The results show that: 1) The gravity centers of the GDR the output values of the main three industries and arable land area show migration trending from southwest to northeast, while the population gravity center shows an excessive growth in the southwest during the same time period. The migration amplitude of the GDP and output values of primary industry, secondary industry, tertiary industry are measurably higher than that of the population. 2) The population gravity center has a negative correlation with the gravity centers of secondary and tertiary industries output values in both longitudinal and latitudinal directions, and a positive correlation with that of primary industry output value in the longitudinal direction. Based on the analysis of correlation coefficient and offset distance, the imbalance between the population and the economy has increased since the 1980s, with regional economic differences now exceeding the international cordon. 展开更多
关键词 regional gravity center model population gravity center economic gravity center Tarim River Basin
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Efficient and rapid accuracy estimation of the Earth's gravitational field from next-generation GOCE Follow-On by the analytical method 被引量:4
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作者 郑伟 许厚泽 +2 位作者 钟敏 刘成恕 员美娟 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第4期563-570,共8页
Firstly, a new analytical error model of the cumulative geoid height using the three-dimensional diagonal tensors of satellite gravity gradiometry (SGG) is introduced based on the variance-covariance matrix principl... Firstly, a new analytical error model of the cumulative geoid height using the three-dimensional diagonal tensors of satellite gravity gradiometry (SGG) is introduced based on the variance-covariance matrix principle. Secondly, a study for the requirements demonstration on the next-generation GOCE Follow-On satellite gravity gradiometry system is developed using different satellite orbital altitudes and measurement accuracies of satellite gravity gradiometer by the new analytical error model of SGG. The research results show that it is preferable to design satellite orbital altitudes of 300 km–400km and choose the measurement accuracies of 10-13/s2 –10-15/s2 from satellite gravity gradiometer. Finally, the complementarity of the four-stage satellite gravity missions, including past CHAMP, current GRACE, and GOCE, and next-generation GOCE Follow-On, is contrastively demonstrated for precisely recovering the Earth’s full-frequency gravitational field with high spatial resolution. 展开更多
关键词 GOCE Follow-On satellite analytical method requirements demonstration satellite gravity gradiometry Earth’s gravitational field
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Application of strength reduction method to dynamic anti-sliding stability analysis of high gravity dam with complex dam foundation 被引量:3
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作者 Deng-hong CHEN Cheng-bin DU 《Water Science and Engineering》 EI CAS 2011年第2期212-224,共13页
Considering that there are some limitations in analyzing the anti-sliding seismic stability of dam-foundation systems with the traditional pseudo-static method and response spectrum method, the dynamic strength reduct... Considering that there are some limitations in analyzing the anti-sliding seismic stability of dam-foundation systems with the traditional pseudo-static method and response spectrum method, the dynamic strength reduction method was used to study the deep anti-sliding stability of a high gravity dam with a complex dam foundation in response to strong earthquake-induced ground action. Based on static anti-sliding stability analysis of the dam foundation undertaken by decreasing the shear strength parameters of the rock mass in equal proportion, the seismic time history analysis was carried out. The proposed instability criterion for the dynamic strength reduction method was that the peak values of dynamic displacements and plastic strain energy change suddenly with the increase of the strength reduction factor. The elasto-plastic behavior of the dam foundation was idealized using the Drucker-Prager yield criterion based on the associated flow rule assumption. The result of elasto-plastic time history analysis of an overflow dam monolith based on the dynamic strength reduction method was compared with that of the dynamic linear elastic analysis, and the reliability of elasto-plastic time history analysis was confirmed. The results also show that the safety factors of the dam-foundation system in the static and dynamic cases are 3.25 and 3.0, respectively, and that the F2 fault has a significant influence on the anti-sliding stability of the high gravity dam. It is also concluded that the proposed instability criterion for the dynamic strength reduction method is feasible. 展开更多
关键词 dynamic anti-sliding stability complex dam foundation dynamic strength reduction method instability criteria elasto-plastie model dynamic time history analysis gravity dam
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Study on Industrial Application of Hydrogen Sulfide Removal by Wet Oxidation Method with High Gravity Technology 被引量:5
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作者 Qi Guisheng Liu Youzhi Jiao Weizhou (Research Center of Shanxi Province for High Gravity Chemical Engineering and Technology, North University of China, Taiyuan 030051) 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2011年第4期29-34,共6页
The removal of hydrogen sulfide from gas plays an important role in rational utilization of resources and environ- mental protection. In this paper, the process of hydrogen sulfide removal by wet oxidation method in a... The removal of hydrogen sulfide from gas plays an important role in rational utilization of resources and environ- mental protection. In this paper, the process of hydrogen sulfide removal by wet oxidation method in a rotating packed bed was investigated in a scale for treating 10 000 Nm3/h of gas. On the basis of studying the influence of the species and con- centration of alkali source, the liquid/gas volume ratio, the high gravity factor, and the hydrogen sulfide content in feed gas on the desulfurization effect, the suitable technological conditions were obtained. The hydrogen sulfide removal efficiency could reach 98.0% under these conditions. The results of continuous operation of process facilities showed that the high gravity method has many merits including higher desulfurization rate, good stability in operation, lower liquid/gas volume ratio, greater operation elasticity, and apparent energy saving effects. 展开更多
关键词 hydrogen sulfide DESULFURIZATION wet oxidation method high gravity
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A Study on the Functional Reliability of Gravity Dam 被引量:1
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作者 Qiang Xu Jianyun Chen Jing Li 《Energy and Power Engineering》 2012年第2期59-66,共8页
The research objective is to design and construct a method for functional reliability analysis of concrete gravity dam. Firstly, the pseudo excitation method was utilized to analyze to calculate the probabilistic char... The research objective is to design and construct a method for functional reliability analysis of concrete gravity dam. Firstly, the pseudo excitation method was utilized to analyze to calculate the probabilistic characteristics of concrete gravity dam excited by random seismic loading. Meanwhile, the response surface method based on weighted regression was associated to that method to analyze functional reliability of concrete gravity dam. Eventually, a test example was given to verify and analyze the convergence and stability of this method. 展开更多
关键词 Concrete gravity DAM RANDOM Load FUNCTIONAL Reliability PSEUDO EXCITATION method
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The Akp-Btk value method and the resultsfor the retrieval of the parameters of the Earth's free core nutation 被引量:1
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作者 雷湘鄂 贾民育 李辉 《Acta Seismologica Sinica(English Edition)》 CSCD 2000年第3期342-350,358,共10页
The rotation of the Earth's liquid core creates the Nearly Diurnal Free Wobble (NDFW). It is one of the problems of researching the Earth's liquid core for us to retrieve the parameters of the Earth's Free... The rotation of the Earth's liquid core creates the Nearly Diurnal Free Wobble (NDFW). It is one of the problems of researching the Earth's liquid core for us to retrieve the parameters of the Earth's Free Core Nutation (FCN),from the Earth's liquid core resonance of gravity tide waves on the diurnal frequency band. Since 1987, some scientists in many different countries have come to calculate the parameters of FCN by using the observational data of gravity tide waves on the diumal frequency band. They basically followed the Stacking method, which needed five diurnal waves for the resolution. In this paper, authors introduced the Aky-Btk value method with clearly geometrical meaning as a new method, which only requires three very high signal-noise-ratio waves o1, K1 and P1 for the resolution. Authors chose the observational data of the three superconducting gravimeter stations respectively located in Cantley of Canada, Wuhan of China and Brussels of Belgium, to compute the parameters of FCN. It was the first time that the observational results of the parameters of FCN obtained from gravitational tide were in accord with the parameters of FCN gained from VLBI since 1987. 展开更多
关键词 Earth's liquid core resonance of gravity tide (LCR) parameters of Earth's free core nutation triangle of LCR Akp-Btk value method
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Uncertainty analysis of ship model vertical center of gravity and transverse moment of inertia test 被引量:1
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作者 史圣哲 郑亚雄 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2015年第1期41-46,共6页
The usability of test results of ship model vertical center of gravity and transverse moment of inertia is generally depends on its uncertainty. Referring to the guidelines for uncertainty analysis in examination of l... The usability of test results of ship model vertical center of gravity and transverse moment of inertia is generally depends on its uncertainty. Referring to the guidelines for uncertainty analysis in examination of liquid dynamic recommended by International Towing Tank Conference ( ITTC), the results were analyzed, bias limits and precision limits were calculated and total uncertainty was estimated. The total uncertainty of six tests on ship model vertical center of gravity is is 0. 16% of the mean value, and the total uncertainty of six tests on ship model transverse moment of inertia is 5.66% of the mean value. The test results show that the total uncertainty of both the multiple tests and the single test is from the precision limits of ship model vertical center of gravity and transverse moment of inertia tests. Thus, the improved measurement system stability can enormously decrease the total uncertainty of multiple tests and the single test. 展开更多
关键词 ship model test vertical center of gravity transverse moment of inertia uncertainty analysis
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