Polybrominated diphenyl ethers in combusted residues and soils from an open burning site of electronic wastes     

Qian Luo  Ming Hong Wong  Zijian Wang  Zongwei Cai 《Environmental Earth Sciences》2013,69(8):2633-2641

Polybrominated diphenyl ethers (PBDEs) are ubiquitous environmental contaminants due to their extensive use. Combusted residue from electronic waste (e-waste) combustion is one of the contamination sources because PBDEs may be deposited in the soil and transported to remote locations. The transport and deposition behaviors of PBDEs released from burning were evaluated by analyzing their concentrations and congener distributions. Total PBDE concentrations were detected in the range from 2379 to 6238 ng/g (dry weight) in the combusted residue samples collected from a large open burning site and from 247.4 to 1422.3 ng/g in soil samples collected from different locations close to the open burning site. BDE-209, 183, 153, 99, and 47 were detected in relative high concentrations in both combusted residue and soil samples. The interpretation of the PBDEs concentrations and congener patterns in the combusted residue and soil samples indicated that PBDEs contamination in soil might be a result of e-waste burning and transportation, and deposit of the combusted residue. The total PBDE concentrations decreased significantly with increasing distance from the burned site, suggesting that the combusted activities were the major source of PBDEs in the region and the transportation behavior of lower brominated congeners might not differ from that of higher brominated congeners for short distances.  相似文献   

Ecotourism planning using multiple criteria evaluation with GIS     

T. Fung  F. K.-K. Wong 《国际地球制图》2013,28(2):87-105

Hong Kong as an international metropolis is well known for its vibrant urban life, which attracts millions of mass conventional tourists for shopping and business. Recently, ecotourism has flourished and attracts ecotourists who visit the ecological and cultural resources of the rural landscape, country parks and marine parks. Yan Chau Tong, also known as ‘Double Haven’, is remote from the urban centre, which helps preserve its natural flavour and cultural heritages such as Hakka walled villages. It is noted as an important site for developing ecotourist activities. A symbiosis of humans and nature cannot be achieved without a sound planning and zoning scheme. This paper investigates the use of IKONOS imagery and a geographic information system for rational planning of ecotourist activities and conservation measures. Through image classification of IKONOS and integrated with ecological data, essential habitats can be mapped and a spatial database is established. Suitable sites for recreational activities (including camping, heritage visiting, hiking and snorkelling) and important ecological habitats can both be identified using multiple criteria evaluation techniques. The use of a multiple objective land allocation model helps resolve conflict between recreation and conservation. Sites are generally identified as (a) those where conservation or recreation should receive the highest priority; (b) those that can be treated as additional recreation or conservation sites; and (c) conflict areas that can serve both purposes. The result can assist in planning land resources for ecotourism to satisfy both objectives and attain sustainability in the area.  相似文献   

Cities On the Plains: The Evolution of Urban Kansas     

Kalyn M. Rossiter  David W. S. Wong  Paul L. Delamater 《The Professional geographer》2013,65(4):609-623

The process of congressional redistricting, delineating boundaries for districts in which voters elect members to the U.S. House of Representatives, has always been an expensive and controversial process. Congressional districts (CDs) are redrawn due to changes in population reflected by the decennial census to ensure equal representation. Laws and regulations literature identifies eight criteria that may be considered when determining the boundaries of CDs and this article focuses on one of those criteria, maintaining communities of interest (COIs). This criterion requires states to preserve these boundaries when delineating CDs but fails to define a COI. This research proposes and evaluates two approaches to define a COI and examines the extent to which this criterion has been adhered to. One definition uses Thiessen polygons and census designated places to delineate COIs based on known cultural places, whereas the other definition uses cluster analysis to group together people with similar sociodemographic characteristics. The results show that the two definitions are feasible for defining a COI. Furthermore, the states largely maintain the COI boundaries within their CDs by only splitting, at most, 17.1 percent of the COIs defined. Existing literature shows that maintaining COIs within CDs leads to higher voter participation and engagement, as well as better representation. The results show that if either definition was adopted, states could comply with this criterion with relative ease. Furthermore, a standard definition could help reduce the cost and controversy surrounding the redistricting process.  相似文献   

A multiresolution analysis of the radio–FIR correlation in the Large Magellanic Cloud     

A. Hughes  T. Wong †  R. Ekers  L. Staveley-Smith  M. Filipovic  S. Maddison  Y. Fukui  N. Mizuno 《Monthly notices of the Royal Astronomical Society》2006,370(1):363-379

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Three‐dimensional analysis of single pile response to lateral soil movements     

J. L. Pan  A. T. C. Goh  K. S. Wong  A. R. Selby 《国际地质力学数值与分析法杂志》2002,26(8):747-758

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Adaptation of existing behaviour models to unsaturated states: application to CJS model     

Jean‐Michel Pereira  Henry Wong  Philippe Dubujet  Patrick Dangla 《国际地质力学数值与分析法杂志》2005,29(11):1127-1155

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Comparing the CO and HI Distributions in Nearby Spiral Galaxies at High Resolution     

Tony Wong  Leo Blitz  J. M. van der Hulst 《Astrophysics and Space Science》2004,289(3-4):211-214

With wide-field CO maps of spiral galaxies at ～6′′resolution provided by the BIMA Survey of Nearby Galaxies (BIMA SONG),it is now feasible to compare the CO and HI distributions in disks onscales of ～1 kpc or less. The results of such a comparisonsuggest that, when azimuthally averaged, the ratio of CO to HIemission, and by implication the molecular-to-atomic gas ratio, isdetermined by the midplane interstellar pressure, with the ISMmetallicity as a secondary factor. A variety of observed phenomena,including the inhibition of molecular cloud and star formation in theouter disks of galaxies, can be understood in terms of thisdependence. We present recent data on the edge-on galaxy NGC 891 thatallow a comparison of the vertical distribution of CO and HI, and willtherefore provide an independent test of these ideas.  相似文献   

Beam patterns of an underwater acoustic vector hydrophone located away from any reflecting boundary     

Wong  K.T. Hoiming Chu 《Oceanic Engineering, IEEE Journal of》2002,27(3):628-637

A vector hydrophone is composed of two or three spatially collocated but orthogonally oriented velocity hydrophones plus an optional collocated pressure hydrophone. A vector hydrophone may form azimuth-elevation beams that are invariant with respect to the sources' frequencies, bandwidths and radial location (in near field as opposed to the far field). This paper characterizes the spatial matched filter beam patterns (a.k.a. fixed or conventional or maximum signal-to-noise ratio beam patterns) and the minimum variance distortionless response (MVDR) beam patterns associated with a single underwater acoustic vector hydrophone distant from any reflecting boundary.  相似文献   

Water effects on rock strength and stiffness degradation     

Louis Ngai Yuen Wong  Varun Maruvanchery  Gang Liu 《Acta Geotechnica》2016,11(4):713-737

Reduction in strength and stiffness in rocks attributed to an increase in water content has been extensively researched on a large variety of rock types over the past decades. Due to the considerable variations of texture and lithology, the extent of water-weakening effect is highly varied among different rock types, spanning from nearly negligible in quartzite to 90 % of uniaxial compressive strength reduction in shale. Readers, however, often face difficulties in comparing the data published in different sources due to the discrepancy of experimental procedures of obtaining the water saturation state and how the raw laboratory data is interpreted. In view of this, the present paper first reviews the terminologies commonly used to quantify the amount of water stored in rocks. The second part of the paper reviews the water-weakening effects on rock strengths, particularly focusing on uniaxial compressive strength and modulus, as well as tensile strength, under quasi-static loading and dynamic loading. The correlation relationships established among various parameters, including porosity, density and fabric of rocks, and external factors such as strain rate, surface tension and dielectric constant of the saturating liquid, absorption percentage and suction pressure, are reviewed and presented toward the end of the paper.  相似文献   

Influences of Normal Loading Rate and Shear Velocity on the Shear Behavior of Artificial Rock Joints     

Zhi Cheng Tang  Louis Ngai Yuen Wong 《Rock Mechanics and Rock Engineering》2016,49(6):2165-2172

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