The material flow concept for materials

Mineral supply and demand data were used to track the flow of a material from its source through stages of production, processing, and fabrication into the consumption and postconsumption phases. In each stage prior to consumption, the quantity of material lost to the environment or recovered for reuse was determined. In the postconsumption stage, the quantity of material discarded was analyzed to determine how much was disposed to landfills, lost through incineration, or dispersed to the environment. Where the consumption stage involved releases to the environment, as in the use of fertilizer, this was noted also. The material flow studies also strived to determine the amount of recycling that was done in the preconsumption and postconsumption phases. Cumulative historical supply data were used to estimate the total inventory of the materials that have been put into service within the United States, and aggregated consumption data based on end use provided a basis for assessing the cumulative effect of those materials on the environment.Correspondence should be directed to Earle B. Amey, U.S. Geological Survey, National Center 983, Reston, Virginia 20192.     

Multiwavelength analysis of a well observed flare from SMM

We describe and analyse observations of an M1.4 flare which began at 17: 00 UT on 12 November, 1980. Ground based H and magnetogram data have been combined with EUV, soft and hard X-ray observations made with instruments on-board the Solar Maximum Mission (SMM) satellite. The preflare phase was marked by a gradual brightening of the flare site in Ov and the disappearance of an H filament. Filament ejecta were seen in Ov moving southward at a speed of about 60 km s^–1, before the impulsive phase. The flare loop footpoints brightened in H and the Caxix resonance line broadened dramatically 2 min before the impulsive phase. Non-thermal hard X-ray emission was detected from the loop footpoints during the impulsive phase while during the same period blue-shifts corresponding to upflows of 200–250 km s^–1 were seen in Ca xix. Evidence was found for energy deposition in both the chromosphere and corona at a number of stages during the flare. We consider two widely studied mechanisms for the production of the high temperature soft X-ray flare plasma in the corona, i.e. chromospheric evaporation, and a model in which the heating and transfer of material occurs between flux tubes during reconnection.     

Exploiting Illusory Grid Lines for Object-Location Memory Performance in Urban Topographic Maps

In order to be successful in spatial orientation tasks, people need to recall locations and configurations of spatial objects from their memory. This understanding of geographic space often arises from experience with cartographic media representing topographic and topological information by graphic symbols. Learning spatial information from graphic media is influenced by different perception-based grouping effects distorting the accuracy of spatial object-positions and their relations. Such geometric inaccuracies can be softened by adding a grid layer, which regionalizes the map and can be used as an additional orientation pattern. This grid layer usually consists of solid lines and overlays semantic information. The present paper reports the results of two empirical studies on object-location memory (OLM) performance. In these studies, the amount of visual detail of the grid layer was reduced. By positioning the grid layer below specific urban topographic objects (study 1), the grid pattern was graphically interrupted. These interrupted grid lines were completed by cognitive completion mechanisms (illusory grid lines) described in the Gestalt principles of closure and continuation. The second experiment examined the maximum grid line gap that is closed by cognitive line completion and keeps an advantage for OLM (study 2).     

A Century of Sea Level Measurements at Newlyn,Southwest England

The Newlyn Tidal Observatory is the most important sea level station in the United Kingdom. It commenced operations in 1915 as part of the Second Geodetic Levelling of England and Wales, and the mean sea level determined from the tide gauge during the first six years (May 1915–April 1921) defined Ordnance Datum Newlyn (ODN) which became the national height datum for the whole of Great Britain. The 100 years of sea level data now available have contributed significantly to many studies in oceanography, geology, and climate change. This paper marks the centenary of this important station by reviewing the sea level (and, more recently, detailed land level) measurements and Newlyn's contributions to UK cartography, geodesy and sea-level science in general. Recommendations are made on how sea and land level measurements at Newlyn might be enhanced.     

长三角地区企业本土并购网络的时空动态性分析

不同于企业绿地投资优选最佳区位,并购投资的关键在于买方和标的企业间的配选、交易与整合,其时空动态性需要从并购双方地理分布格局、投资联系网络结构等方面进行刻画。本文以长三角作为研究案例区,通过企业并购投资数据库建构与多元技术方法应用,重点分析区域尺度的企业并购网络时空动态性,研究发现：① 长三角企业并购双方共同集聚特征明显,主要分布在上海以及沪宁、沪杭甬沿线地区,但并购双方空间集散趋势出现分化,标的企业向外围区扩散的态势更为明显,买方企业则进一步向上海和区域性中心城市市区集聚。② 长三角基于企业跨区域并购投资联系的县市（区）网络不断加密、拓展,但上海中心城区、浦东新区以及杭州、南京等城市市区的核心节点地位日益强化,核心区与外围区、一市三省、大都市与其周边地区之间企业并购投资联系强度的空间“不对称性”也较为明显。③ 伴随区域一体化发展进程,长三角企业并购网络时空动态性经历三个阶段,即单核心、弱网络联系阶段,单核心、多次级重要节点、网络联系加强阶段,多核心、多层级复杂网络结构基本形成阶段。企业本土并购网络的时空动态性探析有助于丰富经济地理学界的企业投资网络及区位模式研究,能够为全国促进企业兼并重组、推动区域经济转型升级发展等决策提供有益参考。     

Pyrolysis-combustion C dating of soil organic matter

Radiocarbon (¹⁴C) dating of total soil organic matter (SOM) often yields results inconsistent with the stratigraphic sequence. The onerous chemical extractions for SOM fractions do not always produce satisfactory ¹⁴C dates. In an effort to develop an alternative method, the pyrolysis-combustion technique was investigated to partition SOM into pyrolysis volatile (Py-V) and pyrolysis residue (Py-R) fractions. The Py-V fractions obtained from a thick glacigenic loess succession in Illinois yielded ¹⁴C dates much younger but more reasonable than the counterpart Py-R fractions for the soil residence time. Carbon isotopic composition (δ¹³C) was heavier in the Py-V fractions, suggesting a greater abundance of carbohydrate- and protein-related constituents, and δ¹³C was lighter in the Py-R fractions, suggesting more lignin- and lipid-related constituents. The combination of ¹⁴C dates and δ¹³C values indicates that the Py-V fractions are less biodegradation resistant and the Py-R fractions are more biodegradation resistant. The pyrolysis-combustion method provides a less cumbersome approach for ¹⁴C dating of SOM fractions. With further study, this method may become a useful tool for analyzing unlithified terrestrial sediments when macrofossils are absent.     

The Effects of Climate Change on the Hydrology and Water Resources of the Colorado River Basin

The potential effects of climate change on the hydrology and water resources of the Colorado River basin are assessed by comparing simulated hydrologic and water resources scenarios derived from downscaled climate simulations of the U.S. Department of Energy/National Center for Atmospheric Research Parallel Climate Model (PCM) to scenarios driven by observed historical (1950–1999) climate. PCM climate scenarios include an ensemble of three 105-year future climate simulations based on projected `business-as-usual'(BAU) greenhouse gas emissions and a control climate simulation based on static 1995 greenhouse gas concentrations. Downscaled transient temperature and precipitation sequences were extracted from PCM simulations, and were used to drive the Variable Infiltration Capacity (VIC) macroscale hydrology model to produce corresponding streamflow sequences. Results for the BAU scenarios were summarized into Periods 1, 2, and 3 (2010–2039,2040–2069, 2070–2098). Average annual temperature changes for the Colorado Riverbasin were 0.5 °C warmer for control climate, and 1.0, 1.7, and 2.4 °C warmer for Periods 1–3, respectively, relative to the historicalclimate. Basin-average annual precipitation for the control climate was slightly(1%) less than for observed historical climate, and 3, 6, and 3%less for future Periods 1–3, respectively. Annual runoff in the controlrun was about 10% lower than for simulated historical conditions, and 14, 18, and 17% less for Periods 1–3, respectively. Analysis of watermanagement operations using a water management model driven by simulated streamflows showed that streamflows associated with control and future BAU climates would significantly degrade the performance of the water resourcessystem relative to historical conditions, with average total basin storage reduced by 7% for the control climate and 36, 32 and 40% for Periods 1–3, respectively. Releases from Glen Canyon Dam to the LowerBasin (mandated by the Colorado River Compact) were met in 80% of years for the control climate simulation (versus 92% in the historical climate simulation), and only in 59–75% of years for the future climate runs. Annual hydropower output was also significantly reduced for the control and future climate simulations. The high sensitivity of reservoir system performance for future climate is a reflection of the fragile equilibrium that now exists in operation of the system, with system demands only slightly less than long-term mean annual inflow.     

Effects of rapid changes in temperature on two estuarine crustaceans

Weight specific oxygen consumption (Q_O2) patterns of the amphipod, Gammarus sp. (acclimated to 5°, 15° and 25°C) and of juvenile blue crabs, Callinectes sapidus (15° and 25°C) were used to evaluate the potential effect of exposure to rapid temperature changes simulating once-through power plant pumped entrainment. Amphipods at all acclimation temperatures and blue crabs at 15°C responded to the temperature changes by increasing Q_O2 above pre-exposure levels after the thermal increase and then returning to pre-exposure levels. The response was judged to be a normal physiological compensation response, not a thermal stress response, as suggested by some investigators. Significant differences were found among seasonal Q_O2, patterns in both species; Q_O2, increased with increasing acclimation temperature. However, no seasonal stress effects were found as a result of exposure to the temperature changes. This implies that the effects of ΔT's up to 10°C from power plants of this design should have no significant impact on these organisms.