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采用基于扩展UNIQUAC模型的AQSOL027软件针对水盐体系Li–Na–K–Mg–Cl–SO4–H2O的六个五元子体系进行相平衡理论计算,首次报道了多个五元子体系在多个温度条件下的相图,将计算相图与已有实验相图以及基于其它热力学模型的计算相图进行了比较。结果表明：AQSOL027在相图计算中具有较好的准确性和可靠性。AQSOL027是一款基于Excel、用于计算复杂多温水-盐体系Li–Na–K–Mg–Ca–H–Cl–(HSO4/SO4)–(CO2/HCO3/CO3)–(H3BO3/B4O7/BO2)–OH–H2O的计算机软件,集成了扩展UNIQUAC模型和相平衡算法,该软件可结合SysCAD和Aspen过程模拟器,实现盐田工艺过程的计算机辅助设计。 相似文献
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《The Journal of geography》2012,111(6):284-285
Abstract This article examines the spatial implications of farm lot shape, a function of the survey system, for the rural landscape. Three aspects of farmstead location within the lot are investigated: the location of the house, the location of the barn, and the distance and direction relationships between the barn and the house. Our findings show that efficiency and lot shape affect farmstead location, in particular that barns are more concentrated behind the house and to the left in rectangular lots than in square lots. Suggestions for classroom and field applications of this methodology in other areas are included. 相似文献
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《Polar Science》2008,2(3):163-174
Isotopic analysis of the Martian lherzolitic shergottite Yamato 000097 yields a Rb–Sr age of 147 ± 28 Ma with an initial 87Sr/86Sr ratio of 0.710490 ± 0.000072, a Sm–Nd age of 152 ± 13 Ma with an initial ɛ143Nd-value of +11.7 ± 0.2, and a 39Ar–40Ar age of ∼260 Ma. The near concordance of these ages, in combination with the Rb–Sr and Sm–Nd initial isotopic signatures, suggests that Yamato 000097 crystallized from low Rb/Sr, light rare earth element depleted source materials ∼150 Ma ago. Although the obtained 39Ar–40Ar age is significantly higher than the Rb–Sr and Sm–Nd ages, Yamato 000097 shows little or no evidence of trapped Martian atmospheric 40Ar. The trapped 40Ar concentration of Yamato 000097 is similar to that of Zagami, suggesting that both basaltic and lherzolitic shergottites may have similarly inherited excess 40Ar from their magmas.The Rb–Sr and Sm–Nd ages, and initial 87Sr/86Sr and ɛ143Nd-values of Yamato 000097 and Yamato 793605 lie on the same isotopic ingrowth curves, suggesting that they came from very similar mantle sources. Allan Hills 77005 was also probably derived from the same source, but Lewis Cliff 88516 appears to be from a distinct but similar source. Yamato 000097 represents the most recent known magmatism from its source, and is the youngest Martian meteorite for which concordant Rb–Sr and Sm–Nd ages have been determined. 相似文献
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While speculation exists on global and regional climate change for temperature and precipitation, relatively little research is available on snowfall and its changes. Twenty-six sites were selected to describe and analyze various characteristics of snowfall in Pennsylvania from 1950–1951 through 1989–1990. Overall, the state experienced a significant stepwise change in seasonal snowfall total during this period. Abnormally high seasonal totals prevailed from 1957–1958 through 1971–1972. This rise in snowfall was accompanied by colder-than-normal temperatures and a dramatic increase in large daily snow events. Principal components analysis (PCA) revealed that the seasonal temporal patterns were not uniform across the state. The PCA revealed four distinct seasonal regions. These regions exhibited everything from nearly linear increases and decreases over time to cyclical formations. PCA performed on the months of November through April each unveiled between three and five separate temporal regions. PCA analyses generally identified an eastern region, a north-central region, and a western region across Pennsylvania. [Key words: regionalization, principal components, variability, snowfall, climate change, Pennsylvania.] 相似文献
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Colleen C. Hiner 《The Professional geographer》2016,68(4):520-532
As examinations of the rural–urban interface move beyond a focus on the rural or urban fringe as a location and move toward examining the patterns and processes that both divide and link rural and urban places, a broader (re)conceptualization of the rural–urban interface becomes increasingly important. Thus far the question of boundaries and interfaces between so-called urban and rural locales has mostly revolved around where and when such boundaries occur (including significant coverage of the differences and conflicts between urban vs. rural people), rather than asking what physical or social functions are being served by the rural–urban interface itself. In response, I (re)frame the rural–urban interface not only as a boundary between two distinct spaces but also as a conduit, a place of exchange, and a flux point between them. Using a particular case of contested ecologies in the exurban Sierra Nevada foothills of California, I (re)conceptualize the rural–urban interface as meaning, model, and metaphor (MMM), situating contrasting people and places in an ongoing negotiation of place and environmental meaning along the (ex)urbanizing edge. Although the differences between rural and urban are increasingly unclear, the division continues to be compelling from environmental and sociopolitical standpoints. I argue that (perceived) boundaries are instrumental in understanding physical–material change and for mitigating social conflicts occurring across them. As such, attention to the patterns, processes, and flows that connect or separate rural and urban areas is critical to forging effective and long-lasting solutions to contemporary social, economic, and environmental problems. 相似文献
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Residential segregation in metropolitan areas has been the subject of much research, but this article analyzes patterns of white–black and white–Hispanic segregation in counties across the United States. Our purpose was to understand county variations in this one dimension of inequality. Conceiving of segregation as relative inequality of access to neighborhood resources, we measured segregation in 2000 by the index of dissimilarity (D) calculated by blocks, mapped the index values, and correlated them with census variables. Three filters enabled us to eliminate counties with characteristics that could have corrupted the analyses, leaving us with more than 1,000 counties in each analysis. Both minority groups were less segregated from whites in the West and South and in metropolitan counties. Lower segregation was strongly associated with higher minority socioeconomic status and higher percentages of minorities living in housing built in the 1990s, and Hispanic–white segregation was lower where more Hispanics were U.S.-born or English proficient. The racial threat hypothesis was supported only weakly and inconsistently. Mapping made it possible to identify regional and local patterns of high and low segregation as well as the lower segregation of suburban counties in some large metropolitan areas. 相似文献
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Universitetslektor dr.scient. Christian Wichmann Matthiessen 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):22-26
Matthiessen. Christian Wichmann: Byerhvervene. Lokaliseringstendenser 1970–83. Geografisk Tidsskrift 87:22–26. København, juni 1987. The Danish pattern of urban employment changed little 1970–83 although dynamic structural changes occurred, and although the total increased 23% to 2,353,366 urban jobs. The manufacturing deconcentration was more than counteracted by growth in no. of tertiary jobs in the large urban places. 相似文献
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《The Professional geographer》2013,65(1):26-27
The Organization of industrial production is becoming increasingly internationalized, and this is having important effects upon the groewth and changing structure of international trade. Three broad group of forces can be identified, each with its own set of economic impacts upon trade linkages: innovations in transport, communication, and manufacturing technology; the growth of multinational organizations; and changes in the politico-economic structure of the world. The international automobile industry is used to illustrate these developments. 相似文献
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《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(1-2):17-27
I årenes løp er det blitt utført ganske omfattende undersøkelser av kandidater til hovedfagsproven i geografi både ved matematisknaturvitenskapelig og ved språklig-historisk embetseksamen, og det vil kanskje være til nytte å få trykt en liste over hovedfagsarbeidenes titler. Landjordcns fysiske geografi. Til matematisk-naturvitenskapelig embetseksamen eller »lektoreksamen« kreves forst eksamen i 3 »bifag«. Videre må man utvide et av disse til »hovedfag«. Dette bestar for det forste i at man skal gjennomfore et selvvalgt vitenskapelig arbeid, og legge fram resultatene i en avhandling; dernest at man ved en muntlig prøve skal vise at man behersker den gren av faget som avhandlingen horer hjemme i. Den fysiske geografi kan deles i en rekke grener som behandler luften, vannet og den faste jord. Kandidater som har spesialisert seg i meteorologi, oceanografi eller limnologi har ved Oslo Universitet ogsa. fått sin embetseksamen med »geografi« som hovedfag. 相似文献
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The method of bi-dimensional empirical mode decomposition (BEMD) and the combined methods of entropy weight–Technique for Order of Preference by Similarity to an Ideal Solution (TOPSIS) were used to decompose gravity–magnetic data and evaluate targets in the Luziyuan Pb–Zn–Fe polymetallic ore field and surrounding areas. Three meaningful bi-dimensional intrinsic mode function (BIMF) images were obtained by BEMD at different wavelengths, depicting different layers of geological architectures in the study area. The results are as follows. (1) The BIMF2 images depict the shallow local geological architecture and show positive gravity–magnetic anomalies of the skarn alteration and Pb–Zn–Fe mineralization distributed around concealed granites. (2) The BIMF3 images depict the medium-depth geological architecture, indicating that concealed granitic stocks, which are shallow extensions of a deeply concealed pluton, intruded along the NE-trending fault. (3) The BIMF4 images depict gravity–magnetic anomalies at greater depth, which likely reflect regional geological architectures, indicating the potential presence of a large, concealed intermediate-acid pluton in the negative anomaly zone. Three potential targets (A, B, and C) were delineated based on BEMD results of the original gravity–magnetic data. The entropy weight–TOPSIS evaluation results show that the ranking of the metallogenic potential of the delineated targets in the study area is B, A, and C, with relative proximity values of 0.4576, 0.3925, and 0.1499, respectively. The results of this study can be used to guide future exploration.
相似文献13.
Zhang Zhiqiang Wang Gongwen Carranza Emmanuel John M. Yang Shuren Zhao Ke Yang Wangdong Sha Deming 《Natural Resources Research》2022,31(4):2163-2179
Natural Resources Research - Methods for the analysis and integration of multi-source geophysical datasets are fundamental technologies for three-dimensional (3D) geological modeling and subsurface... 相似文献
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Ryan J. Bunting Oliver Yang Chang Christopher Cowen Richard Hankins Staci Langston Alexander Warner 《The Professional geographer》2018,70(1):34-46
The combination of crime mapping and geospatial analysis methods has enabled law enforcement agencies to develop more proactive methods of targeting crime-prone neighborhoods based on spatial patterns, such as hot spots and spatial proximity to specific points of interest. In this article, we investigate the spatial and temporal patterns of the neighborhood crimes of aggravated assault and larceny in 297 census tracts in Miami–Dade County from 2007 to 2015. We use emerging hot spot analysis (EHSA) to identify the spatial patterns of emerging, persistent, continuous, and sporadic hot spots. In addition, we use geographically weighted regression to analyze the spatial clustering effects of sociodemographic variables, poverty rate, median age, and ethnic diversity. The hot spots for larceny are much more diffused than those for aggravated assaults, which exhibit clustering in the north over Liberty City and Miami Gardens and in the south near Homestead, and the ethnic heterogeneity index has a moderate and positive effect on the incidence of both larceny and aggravated assaults. The findings suggest that law enforcement can better target prevention programs for violent versus property crime using geospatial analyses. Additionally, the ethnic concentration of neighborhoods influences crime differently in neighborhoods of different socioeconomic status, and future studies should account for spatial patterns when estimating conventional regression models. 相似文献
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Using land reclamation information from gazetteers and corresponding historical records as further evidence, we extracted information about land reclamation in the early years of reclamation (at the “beginning date”) and during the climax period (the maximum extent). We analyzed land reclamation processes in the farming–grazing transitional zone in northeast China during the Qing Dynasty (1644–1911). Among thirty-seven counties for which the beginning date of land reclamation was recorded, 32 percent began reclamation early, primarily between the Shunzhi (1644–1661) and the Kangxi reigns (1662–1722), 19 percent were exploited during the Yongzheng reign (1723–1735), and 19 percent were exploited during the Guangxu reign (1875–1908). Among forty-six counties for which the maximum extent of land reclamation was recorded, the counties of Fengning, Longhua, and Longjiang were extensively exploited before 1800. From 1800 to 1860, four counties were extensively exploited, including Changtu County, Horqin Left Wing and Behind Banner, Horqin Left Wing and Middle Banner, and Shangyi County. Most counties were extensively exploited after 1860. Land reclamation was usually carried out by Han farmers, who were either recruited by Mongol landowners or were fleeing famine. Extensive land reclamation in the majority of counties was conducted during the Guangxu reign (1875–1908) in the late Qing Dynasty, when the Qing government implemented the policy of promoting Han migration to strengthen its hold on the frontier by distributing land. 相似文献
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Natural Resources Research - In this study, the adsorption–desorption/induced strains/permeability characteristics of seven columnar coal samples with Ro.ran ranging from 0.42 to 3.23% were... 相似文献
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Inequality has been the subject of intense debates in China, but inequality across cities remains less studied. This article investigates economic inequality based on prefectural-level cities during the period from 1990 to 2010. Statistical analyses indicate that interregional inequality among cities has increased, which is mostly attributable to widening intraregional inequality, especially within the western region. The high gross domestic product (GDP) per capita clusters emerged in the Pearl River Delta in the 1990s, spread to the Yangtze River Delta in the 2000s, and then reached north China in the 2010s. In contrast, the number of low GDP per capita clusters significantly increased in the central and western regions in the 2010s. In addition, the significance of national development zones and foreign direct investment indicates the greatest effect of globalization on the increasing intercity inequality. Decentralization also contributes to the intercity inequality of China. We suggest that in addition to national programs aimed at reducing the inequality between the eastern region and the rest of China, efforts are needed to reduce inequality within each region through provincial and local government policies, especially in western China. Key Words: China, cluster, decentralization, globalization, regional inequality, urban inequality. 相似文献