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671.
Except for the decade 1941-1951, in which Punjab's population declined because of a huge exchange of population between India and Pakistan and a large loss of life, the decade 1971-1981 was the 1st decade since 1911 to experience a deceleration in the growth rate of the rural population of Punjab, India. The deceleration was due to out-migration to urban areas. The scheduled caste population increased 28.37% between 1971 and 1981, while the nonscheduled caste population increased by only 13.32%, which was considerably below the rate of natural increase. Nonscheduled castes had experienced substantial out-migration because of 1) improved transport and communication facilities which enabled them to move to urban centers; 2) mechanization of main farming operations and easy availability of migrant laborers which lessened the need for family labor; 3) the rise of a relatively mobile younger generation with a high literacy rate; 4) rapidly decreasing land holdings which strengthened the push factor in the countryside; and 5) rising aspirations, especially among the younger generation. In 1981, Sikhs constituted 71.3% of the rural population in Punjab, followed by Hindus (26.51%), Christians (1.25%), and Muslims (.89%). From 1971-1981, Muslims experienced the greatest increase (49.29%). Sikhs grew by 20.74% and Hindus by 9.02%. The Sikhs high growth rate was due to 1) a new technique for counting religious affiliation in which all members of a household are considered the same religion as the head of household and 2) conversion of Hindus to Sikhism. Hindus had a low growth rate because 1) the new method of counting religious affiliation and 2) rural-urban migration. The area with the lowest population increase resulted from industrialists and other nonagriculturists buying farmland, causing the agriculturists to move away to less desirable land. Conclusions are 1) the sharp rural-urban division along religious lines should be lessened, 2) Sikhs' lag in urbanization and upward mobility should be decreased, and 3) nonagriculturalists should be prevented from buying farm land from peasants along main roads and around urban centers.  相似文献   
672.
Book reviews     
THE CAPITALIST SPACE ECONOMY: Geographical Analysis after Ricardo, Marx and Sraffa by E. Sheppard and T. J. Barnes. 15 × 22 cm, xviii and 328 pages. Unwin Hyman: London 1990 (ISBN 004 330401 X) £40.00 hard; (ISBN 004 330402 8) £14.95 (soft).

THE INTERNATIONAL STEEL INDUSTRY: Restructuring, State Policies and Localities by R. Hudson and D. Sadler. 14 × 22 cm, xii and 163 pages. Routledge: London 1989 (ISBN 0 415 02186 3) $A89.95 (hard).

INDUSTRIAL TRANSFORMATION AND CHALLENGE IN AUSTRALIA AND CANADA (Carleton Library No. 164) edited by R. Hayter and P. D. White. 15 × 23 cm, x and 340 pages. Carleton University Press: Ottawa 1990 (ISBN 0 88629 129 1) $A34.95 (hard); (ISBN 0 88629 128 3) $A 19.95 (soft).

LABOUR MIGRATION. The Internal Geographical Mobility of Labour in the Developed World edited by J. H. Johnson and J. Salt. 15 × 24 cm, viii and 215 pages. David Fulton: London 1990 (ISBN 1 85346 120 2) £30.00 (hard).

CITIES IN SPACE: CITY AS PLACE by D. Herbert and C. Thomas. 15 × 23 cm, xi and 340 pages. David Fulton: London 1990 (ISBN 1 85346 138 5) £35.00 (hard); (ISBN 1 85346 109 1) £14.95 (soft).

THE NEW URBAN FRONTIER. Urbanisation and City Building in Australasia and the American West by L. Frost. 15 × 23 cm, xvii and 226 pages. New South Wales University Press: Sydney (ISBN 0 86840 268 0) $A24.95 (soft).

SYDNEY: A Social Atlas by R. Horvath, G. E. Harrison and R. M. Dowling. 19 × 28 cm, 110 pages. Sydney University Press: Sydney 1989 (ISBN 0 424 00144 6) $A19.95 (soft).

CHANGE AND ADJUSTMENT IN NORTHERN NEW SOUTH WALES edited by D. J. Walmsley. 17 × 23 cm. 118 pages. Department of Geography and Planning, University of New England: Armidale 1990 (ISBN 0 85834 887 X) $A10.00 (soft).

ANNOTATED BIBLIOGRAPHY OF URANIUM IN AUSTRALIA (Cover Title: URANIUM IN AUSTRALIA 1970–1987: An Annotated Bibliography) by C. O'Faircheallaigh, A. Webb and D. Wade‐Marshall. 18 × 25 cm, xi and 306 pages. North Australia Research Unit, Australian National University: Darwin 1989 (ISBN 07315 05433).  相似文献   

673.
Various studies have revealed high concentrations of contaminants such as organochlorines (OCs) and heavy metals in Mediterranean cetaceans. A geographical trend of contamination (PCBs and DDTs) has been found for striped dolphin (Stenella coeruleoalba). In this study we used a non-lethal approach (skin biopsy) to investigate bioaccumulation of OCs, including polychlorobiphenyls (PCBs), DDTs, polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs), trace elements (Hg, Cd, Pb) and CYP1A activity (BPMO) in nine striped dolphins sampled in the Aeolian area (Sicily - Italy) in summer 2002. The arithmetic mean value of BPMO activity in this group was 43.46 AUF/g tissue/h. This value is approximately 3 times and 5 times lower, respectively, than the value found in the Ionian and in the Ligurian groups. Skin biopsies of striped dolphins emerged as a suitable material for assessing the toxicological status of the various Mediterranean groups.  相似文献   
674.
675.
A field experiment was conducted under rainfed environment of Pothowar region of Pakistan to assess physical properties of soil as influenced by various green manure legumes (sesbania, cluster bean and rice bean) and different P levels (0, 30, 60, 90 kg P2O5/ha). Highest fresh biomass was observed in sesbania (23 t/ha) followed by cluster bean (19 t/ha) and lowest in rice bean (17 t/ha). Maximum crude protein content was found in sesbania (17%) followed by rice bean (10%) and cluster bean (8%). Green manuring crops, on average reduced soil bulk density (5%), enhanced total porosity (8%), and macropores and large mesopores (28%). Maximum reduction (7%) in soil bulk density, and an increase (11%) in total soil porosity and available water (17%) was observed in plots where sesbania was incorporated as green manuring crop. The order of effectiveness in improving bulk density, macro and mesopores was sesbania > cluster bean > rice bean. Sesbania produced greater number of macro and large mesopores about 41% increase over control followed by cluster bean (29%) and rice bean (16%). Phosphorus application showed meager positive impact on various soil physical properties but did not significantly increased porosity or reduced bulk density. Significant differences in volume fraction in pore space suggest that pore space on a volume basis was much higher in sesbania-amended soil than in other treatments.  相似文献   
676.
677.
678.
The exsolution of magmatic hydrosaline chloride liquids   总被引:14,自引:0,他引:14  
Jim D. Webster   《Chemical Geology》2004,210(1-4):33-48
Hydrosaline liquid represents the most Cl-enriched volatile phase that occurs in magmas, and the exsolution of this phase has important consequences for processes of hydrothermal mineralization and for volcanic emission of Cl to the atmosphere. To understand the exsolution of hydrosaline liquids in felsic to mafic magmas, the volatile abundances and (Cl/H2O) ratios of more than 1000 silicate melt inclusions (MI) have been compared with predicted and experimentally determined solubilities of Cl and H2O and associated (Cl/H2O) ratios of silicate melts that were saturated in hydrosaline chloride liquid with or without aqueous vapor in hydrothermal experiments. This approach identifies the minimum volatile contents and the values of (Cl/H2O) at which a hydrosaline chloride liquid exsolves from any CO2- or SO2-poor silicate melt. Chlorine solubility is a strong function of melt composition, so it follows that Cl solubility in magmas varies with melt evolution. Computations show that the (Cl/H2O) ratio of residual melt in evolving silicate magmas either remains constant or increases to a small extent with fractional crystallization. Consequently, the initial (Cl/H2O) in melt that is established early during partial melting has important consequences for the exsolution of vapor, vapor plus hydrosaline liquid, or hydrosaline liquid later during the final stages of melt ascent, emplacement, and crystallization or eruption. It is demonstrated that the melt (Cl/H2O) controls the type of volatile phase that exsolves, whereas the volatile abundances in melt control the relative timing of volatile phase exsolution (i.e., the time of earliest volatile exsolution relative to the rate of magma ascent and crystallization history).

Comparing melt inclusion compositions with experimentally determined (Cl/H2O) ratios and corresponding volatile solubilities of hydrosaline liquid-saturated silicate melts suggests that some fractions of the eruptive, calc-alkaline dacitic magmas of the Bonnin and Izu arcs should have saturated in and exsolved hydrosaline liquid at pressures of 2000 bars. Application of these same melt inclusion data to the predicted volatile solubilities of Cu-, Au-, and Mo-mineralized, calc-alkaline porphyritic magmas suggests that the chemical evolution of dioritic magmas to more-evolved quartz monzonite compositions involves a dramatic reduction in Cl solubility that increases the probability of hydrosaline liquid exsolution. The prediction that quartz monzonite magmas should exsolve a hydrosaline chloride liquid, that is potentially mineralizing, is consistent with the general observation of metal-enriched, hypersaline fluid inclusions in the more felsic plutons of numerous porphyry copper systems. Moreover, comparing the volatile contents of melt inclusions from the potassic, alkaline magmas of Mt. Somma-Vesuvius with the predicted (Cl/H2O) ratios of hydrosaline liquid-saturated melts having compositions similar to those of the volatile-rich, alkaline magmas associated with the orthomagmatic gold–tellurium deposits of Cripple Creek, Colorado, suggests that hydrosaline chloride liquid should have exsolved at Cripple Creek as the magmas evolved to phonolite compositions. This prediction is consistent with the well-documented role of Cl-enriched, mineralizing hydrothermal fluids at this major gold-mining district.  相似文献   

679.
Rats were raised on a variety of isotopically controlled diets comprising 20% C3, C4 or marine protein and C3 and/or C4 non-protein or energy (i.e. sucrose, starch and oil) macronutrients. Compound specific stable carbon isotope (δ13C) analysis was performed on the cholesterol isolated from the diet (n=7 ) and bone (n=15 ) of these animals and the values compared with bulk δ13C measurements of bone collagen and apatite. The dietary signals reflected by these three bone biochemical components were investigated using linear regression analysis. δ13C values of bone cholesterol were shown to reflect whole diet δ13C values, collagen to reflect mainly dietary protein values and apatite to reflect whole diet values. Further correlations between dietary protein-to-energy spacings (Δ13Cprot-engy = δ13Cprotein - δ13Cenergy) and whole diet-to-bone component fractionations (Δ13Cbcomp-wdiet = δ13Cbone component - δ13Cwhole diet) indicates that for hypothetical diets where protein δ13C values are equal to energy values, fractionations between whole diet and bone biochemical fractions are -3.3‰ for cholesterol, +5.4‰ for collagen and +9.5‰ for apatite. Moreover, the narrow range of variation observed in apatite-to-cholesterol spacings (Δ13Capat-bchol) suggests that cholesterol δ13C values can potentially also be used as an independent test for the isotopic integrity of apatite δ13C values. These insights into bone cholesterol, collagen and apatite dietary signals, diet-to-bone fractionations and bone component-to-bone component spacings provide the basis for more accurate interpretations of the dietary behaviour of archaeological populations and food webs when the δ13C analysis of bone is employed.  相似文献   
680.
Jiménez  J. C.  Raga  G. B.  Baumgardner  D.  Castro  T.  Rosas  I.  Báez  A.  Morton  O. 《Natural Hazards》2004,31(1):21-37
A 17-day field campaign was carried out in April–May 1999 to determine thecontribution that gaseous volcanic emissions make to the compositionof solid particles,particularly to the presence and quantity of sulfates. Theexperimental site was located inTonantzintla (in the State of Puebla), only 30 km E from the volcanoPopocatépetl, whichhas been in an active phase since the end of 1993. An analysis ofthe carbon monoxide(CO) and sulfur dioxide (SO2) in the ambient air identifiedvolcanic influence in 6 out ofthe 17 days sampled. Particles collected in an 8-stage cascadeimpactor were analyzed for inorganic ions (by liquid chromatography).A non-parametric test indicates asignificant difference on the total particle mass and thesulfate fraction between days withand without volcanic influence. This difference was predominantlyobserved in the stages that collect the smaller particles. Windsat 500 mb (roughly corresponding to thesummit of the volcano) indicate a westerly transport from thevolcano to the experimentalsite, even though surface winds do not show a clear signal ofsuch a transport. Back trajectories from the experimental site werecalculated and clearly indicated that air parcels on the daysindependently identified as with volcanic influence had indeed passed over the volcano.  相似文献   
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