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11.
Assessing China’s human-environment relationship 总被引：3，自引：0，他引：3
Journal of Geographical Sciences - China’s coupled human-environment system (CHES) is assessed here via a systems schema that emphasizes the complex interactions of components and their... 相似文献
12.
N. Tolich Y. -D. Chan C. A. Currat B. K. Fujikawa R. Henning K. T. Lesko A. W. P. Poon M. P. Decowski J. Wang K. Tolich 《Earth, Moon, and Planets》2006,99(1-4):229-240
A significant fraction of the 44TW of heat dissipation from the Earth’s interior is believed to originate from the decays
of terrestrial uranium and thorium. The only estimates of this radiogenic heat, which is the driving force for mantle convection,
come from Earth models based on meteorites, and have large systematic errors. The detection of electron antineutrinos produced
by these uranium and thorium decays would allow a more direct measure of the total uranium and thorium content, and hence
radiogenic heat production in the Earth. We discuss the prospect of building an electron antineutrino detector approximately
700 m3 in size in the Homestake mine at the 4850’ level. This would allow us to make a measurement of the total uranium and thorium
content with a statistical error less than the systematic error from our current knowledge of neutrino oscillation parameters.
It would also allow us to test the hypothesis of a naturally occurring nuclear reactor at the center of the Earth. 相似文献
13.
kif7 is a member of the kinesin superfamily members which are molecular motor proteins that move along microtubules in a highly regulated manner through ATP hydrolysis. In this paper, we report on the cloning of the Oryziasmelastigmakif7 (omkif7) using primers designed according to the Japanese medaka (Oryziaslatipes) database. The cloned omkif7 has an open reading frame of 3762bp and is deduced to encode a polypeptide of 1254 amino acids that possesses the putative ATP-binding and microtubule-binding motifs in its motor domain at the N-terminal region. We characterized the cloned omkif7 by comparison with the zebrafish kif7. Both omkif7 and zebrafish kif7 are shown to be expressed in all embryonic stages and adult tissues examined with higher expression level in the testis and ovary. Whole-mount in situ hybridization revealed that the expression of omkif7 is ubiquitous during the early stages of embryonic development, but became more restrictive and localized to the brain, fin bud and eye at later development. This study suggested that the brackish O.melastigma can serve as a good seawater model organism for developmental studies by utilizing the resources developed from its close relative of the Japanese medaka. 相似文献
14.
15.
P. Poon E. A. C. Liepa D. R. Cohen I. J. Pringle D. A. Burkett 《Australian Journal of Earth Sciences》2020,67(4):575-590
AbstractThere is significant economic interest in the Murray Basin of southeastern Australia as it is proving to be a major heavy mineral sands (HMS) province that will be one of Australia’s major source for production of rutile, zircon and ilmenite. The distribution and provenance of HMS resources in the Murray Basin is poorly understood because of its huge size, limited exploration and the complex depositional, structural and weathering mechanisms in their development. In this paper, we focus on the Copi North and Magic deposits some 130–180?km south of Broken Hill, NSW. The heavy mineral assemblages of the Copi North and Magic deposits are very similar, with the main economic minerals being ilmenite, leucoxene, pseudorutile, rutile and zircon. Intensive fracturing and brecciation are identified in many samples and are inferred to have been initially caused by multi-stage deformational processes associated with metamorphism and then further developed through alluvial and eolian transportation. Both deposits are classified as ‘medium sands, symmetrical, mesokurtic and moderately well-sorted’. The majority of economic minerals are of low to medium sphericity and subrounded, along with abundant polished eolian quartz grains. The Copi North deposit has coarser and more poorly sorted sediments with higher HMS grades and magnetics content than the Magic deposit, reflecting a higher energy depositional environment. The main source for the HMS for the Copi North and Magic deposits is largely ascribed to the Broken Hill Block. Previous studies have shown that the Broken Hill orebody underwent substantial sub-aerial weathering over hundreds of millions of years. In addition, the complex metamorphic events experienced by the Broken Hill Block were capable of forming the broad series of minerals identified within the Copi North and Magic deposits. The HMS were believed to have been transported through paleovalleys near the Mulculca Fault in a southeast direction representing a feeder system into the NW Murray Basin. Both deposits feature a relatively linear geometry (roughly parallel to the strike of the paleoshoreline), with high HMS grades, modest tonnages, and coarser sediments when compared to WIM-style offshore deposits. Compared to other strandline HMS deposits of the Murray Basin, they are smaller in size although have similar high grades of 3.7–6.9% THM and similar proportions of the HMS assemblage of ilmenite, leucoxene, rutile and zircon. Deposits of similar size and grade are likely to occur throughout the northern part of the Murray Basin.
- KEY POINTS
Both the Copi North and Magic deposits contain similar mineral assemblages with the provenance of the heavy minerals ascribed to the Broken Hill Block.
A relatively high energy inshore environment is inferred for the Copi North deposit while a lower energy environment associated with either a foreshore or backshore environment is inferred for the Magic deposit.
Deposits of similar mineralogy, grades and size are likely to occur elsewhere throughout the northern Murray Basin.
16.
Use of fuzzy sets for evaluating shear strength of soils 总被引：1，自引：0，他引：1
Poon Hwei Chuang 《Computers and Geotechnics》1995,17(4):425-446
The shear strength of soils measured in laboratory tests may be different from the in-situ values. This is due to imperfections in the laboratory measurement of soil properties. Expert opinions, based on professional judgements and experience gained in related works, which are usually expressed linguistically, can be sought to assess the measurement biases. The theory of fuzzy sets is a useful tool for conveying this type of subjective information in a computer-usable form. A quantitative methodology which uses fuzzy set theory to represent and process expert opinions, updates the experimental results to more realistic values. A numerical illustration shows that the proposed methodology is simple to use, and produces consistent results. The methodology can be easily implemented using microcomputers to give rapid solutions. 相似文献
17.
Nga Yu Ho Vincent Wai Tsun Li Wing Lin Poon Shuk Han Cheng 《Marine pollution bulletin》2008,57(6-12):425
kif7 is a member of the kinesin superfamily members which are molecular motor proteins that move along microtubules in a highly regulated manner through ATP hydrolysis. In this paper, we report on the cloning of the Oryzias melastigma kif7 (omkif7) using primers designed according to the Japanese medaka (Oryzias latipes) database. The cloned omkif7 has an open reading frame of 3762bp and is deduced to encode a polypeptide of 1254 amino acids that possesses the putative ATP-binding and microtubule-binding motifs in its motor domain at the N-terminal region. We characterized the cloned omkif7 by comparison with the zebrafish kif7. Both omkif7 and zebrafish kif7 are shown to be expressed in all embryonic stages and adult tissues examined with higher expression level in the testis and ovary. Whole-mount in situ hybridization revealed that the expression of omkif7 is ubiquitous during the early stages of embryonic development, but became more restrictive and localized to the brain, fin bud and eye at later development. This study suggested that the brackish O.melastigma can serve as a good seawater model organism for developmental studies by utilizing the resources developed from its close relative of the Japanese medaka. 相似文献
18.
19.
This paper examines two propositions in the creative-class debate in the context of China’s large cities. The first evaluates Richard Florida’s contention that creative workers enjoy higher level of well-being and are happier than blue-collar workers. The second investigates the influence of urban amenities, lifestyle, and work on creative workers’ happiness. Both propositions are analyzed in relation to China’s post-Socialist, industrial, and mining cities. Based on data from a household survey, the results indicate that Chinese creative workers are indeed happier in post-Socialist, or service-sector oriented, cities. However, creative work does not explain their happiness. Stable social sites that reinforce authentic experience of urban cultural amenities (e.g. the teahouse rather than modern coffeehouses, bars, and theaters) are a significant factor for creative-class happiness in post-Socialist Chinese cities. However, creative work is more likely to explain creative-class happiness in mining cities. Further, our study found that blue-collar workers report a higher level of happiness in those settings with less pronounced inter- and intra-class distinctions at the workplace—in those places where power and status are more evenly distributed. 相似文献
20.
Jochen F. Müller Caroline Gaus Joelle A. Prange Olaf Ppke Ka Fai Poon M. H. W. Lam Paul K. S. Lam 《Marine pollution bulletin》2002,45(1-12)
Concentrations of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in 14 sediment samples collected from four sites in the Mai Po Marshes Nature Reserve (within a RAMSAR Site) and from another six sites in Victoria Harbour and along the Hong Kong coastline. Elevated levels of PCDDs, and particularly OCDD, were detectable in all samples collected from the Mai Po Marshes and five of the six sites. In contrast to PCDDs, PCDFs were mainly found in sediment samples collected from industrial areas (Kwun Tong and To Kwa Wan) in Victoria Harbour. PCDD/F levels and congener profiles in the samples from the Mai Po Marshes Nature Reserve in particular show strong similarities to those reported in studies which have attributed similar elevated PCDD concentrations to nonanthropogenic PCDD sources. 相似文献