舟山潮间带生态学研究：Ⅱ.数量及其分布

舟山潮间带生物种类数量的平面分布与盐度和海岸开敞性有关,垂直分布与潮汐有关;群落数量的水平分布与底质和海岸开敞性有关,垂直分布与潮汐有关。舟山潮间带生物有明显的分带现象,隐蔽的岩岸区分为:滨螺带和藤壶-牡蛎带两个带;开敞性岩岸区分为:滨螺带,藤壶-(虫戚)-藻类带及藻类带3个带。沙滩区分为:沙蟹带和浅蛤-斧蛤带两个带;泥沙滩区分为:盐碱植物-滨螺带和招潮蟹-大眼蟹带;泥滩区分为:蟹守螺-囊螺带和蟹守螺-织纹螺带。     

汉江上游郧县段黄土古土壤序列风化成壤特征以及成壤环境演变

对汉江上游进行野外实地详细调查,在湖北省郧县尚家河台地前沿发现了典型的全新世黄土-古土壤沉积剖面,通过粒度、磁化率、吸湿水和烧失量分析表明,黏粒、细粉砂、磁化率、吸湿水和烧失量在古土壤层S₀出现高值,在L₁、L_t、L₀为低值;而粗粉砂、细砂粒和粗砂粒在S₀为低值,在L₁、L_t、L₀为高值。这些指标的变化说明了全新世以来的气候和成壤环境的变化特征,即在古土壤S₀形成时期,气候温暖湿润,成壤作用非常强烈;黄土堆积时期气候相对干旱,成壤作用较弱。     

青藏高原农区农户的家庭能源消费研究

农村能源转型是能源消费革命的重要组成部分。基于问卷调查和入户访谈,对青海省10个县(区)的318户农区家庭用能信息进行调查,辨识了青海省农区不同收入分层家庭的能源消费模式,并通过建立典型家庭能源流模型,总结了家庭能获取-消费-废弃过程的形态变化。结果显示:青海省农区家庭能源消费以煤炭、薪柴和秸秆为主,非商品能源消费占比为49.6%,清洁能源使用率低。煤炭消费在5类家庭中均占比最高,薪柴和秸秆消费在低收入家庭占比较高。高收入家庭能源消费类型更多,消费量也大,能源流动更复杂。最后,根据青海省的经济地理特征,提出相应政策建议。     

Metallic Mineral Resources in the Twenty-First Century. I. Historical Extraction Trends and Expected Demand

Industrial, technological, and economic developments depend on the availability of metallic raw materials. As a greater fraction of the Earth’s population has become part of developed economies and as developed societies have become more affluent, the demand on metallic mineral resources has increased. Yet metallic minerals are non-renewable natural resources, the supply of which, even if unknown and potentially large, is finite. An analysis of historical extraction trends for eighteen metals, going back to the year 1900, demonstrates that demand of metallic raw materials has increased as a result of both increase in world population and increase in per-capita consumption. These eighteen metals can be arranged into four distinct groups, for each of which it is possible to identify a consistent pattern of per-capita demand as a function of time. These patterns can, in turn, be explained in terms of the industrial and technological applications, and in some cases conventional uses as well, of the metals in each group. Under the assumption that these patterns will continue into the future, and that world population will grow by no more than about 50% by the year 2100, one can estimate the amount of metallic raw materials that will be required to sustain the world’s economy throughout the twenty-first century. From the present until the year 2100, the world can be expected to require about one order of magnitude more metal than the total amount of metal that fueled technological and economic growth between the age of steam and the present day. For most of the metals considered here, this corresponds to 5–10 times the amount of metal contained in proven ore reserves. The two chief driving factors of this expected demand are growth in per-capita consumption and present-day absolute population numbers. World population is already so large that additional population growth makes only a small contribution to the expected future demand of metallic raw materials. It is not known whether or not the amount of metal required to sustain the world’s economy throughout this century exists in exploitable mineral resources. In the accompanying paper, I show that it is nevertheless possible to make statistical inferences about the size distribution of the mineral deposits that will need to be discovered and developed in order to satisfy the expected demand. Those results neither prove nor disprove that the needed resources exist but can be used to improve our understanding of the challenges facing future supply of metallic raw materials.     

Recent water quality trends and a comparison to sediment-core records for two riverine lakes of the Upper Mississippi River basin: Lake St. Croix and Lake Pepin

Long-term water quality monitoring data from two riverine lakes in the Upper Mississippi River basin, Lakes St. Croix and Pepin, were analyzed to compare the long-term average water quality conditions and land use distributions, water quality trends and loads at lake inlets and outlets, trends from long-term versus short-term monitoring records, and the ability of paleolimnological cores to accurately infer lake water quality conditions. During the 1976–2004 period, the long-term average concentrations of nutrients, suspended solids, and chlorophyll-a were consistently lower at the Lake St. Croix inlet versus the Lake Pepin inlet, which drains a greater proportion of urban and agricultural runoff. Despite these differences, nutrient trends were similar at the inlets to both lakes; reductions in total phosphorus and ammonium concentrations were attributed to improvements in point source technologies, whereas increasing nitrate concentrations were attributed to both point source changes and nonpoint source increases. Despite improvements in several water quality variables, nitrate concentrations are increasing in both lakes, sediment trends indicate persistent nonpoint source inputs to Lake Pepin, and current total phosphorus concentrations remain well above pre-1950s levels in both lakes. Since urban development and agriculture are increasing in the Lake St. Croix and Lake Pepin Watersheds, continued point source regulation and additional nonpoint source control efforts will be needed to further improve water quality in these lakes. The 1976–2004 trends for most water quality variables were similar at inlet versus outlet sites on Lake St. Croix. Trends at Lake Pepin inlet versus outlet sites were less similar, but data availability limited the comparison to the 1993–2003 period. While the truncated data record highlighted short-term trends in both lakes, the full data record was most useful for exploring general patterns in water quality. Length of monitoring record affected our ability to detect trends at the inlets to both lakes, and altered the magnitude of detected trends. During the two decades of the 1980s and 1990s, paleolimnological estimates of retained phosphorus loads were similar to those estimated from recent water quality monitoring. These similarities support the use of paleolimnological approaches to infer past water quality conditions in Lakes St. Croix and Pepin. This is one of eight papers dedicated to the “Recent Environmental History of the Upper Mississippi River” published in this special issue of the Journal of Paleolimnology. D. R. Engstrom served as guest editor of the special issue.     

重庆万盛煤矸石山自燃爆炸型滑坡碎屑流成因探讨

2 0 0 4 - 0 5 - 0 5重庆万盛胡家沟煤矸石山发生滑坡碎屑流灾害。灾害发生时,伴随巨大的响声和刺鼻气味,约2 0×10 4m3 煤矸石碎屑以极高初始速度崩滑而下,滑体横扫运动途中一切障碍,垂直坡降32 0m ,水平运动距离6 0 0m。造成重大人员和财产损失。通过实地考察和实验研究,作者认为煤矸石山中硫铁矿和碳氧化物升温,煤矸石山自燃、内部热量大量积聚所导致的煤矸石山的爆炸,是使大量矸石脱离矸石山形成此次煤矸石高速滑坡碎屑流灾害的主要原因     

构筑于GIS-GPS-GSM技术集成的120急救系统设计

该文介绍了一个基于 3G集成的 12 0急救系统的设计 :信息流的分析 ,系统结构组成 ,以及构建 12 0急救系统的核心技术分析。并对与GIS、GPS技术联系紧密的三个重要部分进行分析 :1)系统构件关系设计 ;2 )数据收录处理 ;3)急救车路径规划。     

Effect of system variables and particle size on physical characteristics of air sparging plumes

Air was injected through a well in a thin transparent tank filled with saturated glass beads to study how the size and air saturation of air sparging plumes are affected by particle size and gradation; operational parameters such as injection pressure, well depth, injection pressure pulsing; and well outlet configuration. V-shaped air plumes with an apex between 40° and 60° were obtained for all tests. The air pressure required to initiate sparging agreed closely with the sum of the air entry pressure and the hydrostatic pressure, with higher initiation pressures required in the fine and well-graded beads. Higher air flow rates and air saturations were obtained in coarser beads at a given pressure, and the variation in flow rate was consistent with estimated air permeabilities. Peak average air saturations were 28–56% for the coarse-medium beads, 10% for the well-graded beads, and 8% for the fine beads. Air saturation and the radius of influence increased modestly (<40%) as the normalized injection pressure exceeded 0.1. Radius of influence increased by approximately a factor of two as the well depth increased, but leveled off once the ratio of radius of influence to well depth reached 0.60–1.05. Pulsing of injection pressure had no effect on the initiation pressure, air flow rate, or air saturation, but increased the size of the air plume and the radius of influence slightly (<15%). Well outlet configuration had only a slight affect the radius of influence (<10%), air saturation (<10%), or air flow rate (<12%). Dye testing showed that water surrounding the air plume circulated during continuous and pulsed sparging. However, pulsed sparging resulted in greater and more defined circulation of water within and adjacent to the air plume, which should reduce mass transfer limitations during sparging.     

Stratigraphy,type and formation conditions of the late precambrian banded iron ores in south China

Based on research on the “Xinyu-type” Sinian iron deposits in Jiangxi Province and metamorphosed iron deposits in Jiangkou and Qidong of Hunan, Sanjiang and Yingyangguan of Guangxi, Longchuan of Guangdong and some other areas in Fujian, the authors have come to the following conclusions:

1. The metamorphosed late Precambrian iron ores widespread in south China may be roughly assigned to two ore belts, namely the Yiyang-Xinyu (Jiangxi)-Jiangkou(Hunan)-Sanjiang (Guangxi) ore belt or simply the north ore belt, and the Songzheng(Fujian)-Shicheng (Jiangxi)-Bailing (Longchuan of Guangdong)-Yingyangguan (Guangxi) ore belt or the south ore belt. Tectonically, the former lies along the southern margin of the “Jangnan Old Land”, while the latter along the northwestern border of the “Cathaysian Old Land”.
2. Iron deposits of this type occur exclusively in the same interglacial horizon of the Sinian Glaciation in south China. Above and below the ore bed there lie the glacial till-bearing volcanic-sedimentary layers.
3. Based on sedimentary features, the iron formations can be divided into four types: silica-iron-basalt formation, silica-iron-clastic rock formation, silica-iron-tuff formation and silica-iron-carbonate rock formation, which progressively grade into each other.
4. Iron ores were formed at the late stage of late Proterozoic rifting in neritic environments, with their distribution governed by the rift valleys on the margins of the “Jiangnan Old Land” and “Cathaysian Old Land”. Consequently, intense mafic volcanism as well as weathering and denudation of palaeocontinent during rifting provided material sources for the formation of iron deposits. Meanwhile, warm and humid stationary neritic environment during the south China great glacial period constitutes favorable palaeoclimatologic and palaeogeographic conditions for the deposition of iron ores.
5. The iron formations have undergone regional metamorphism of greenschist-amphibolite facies.

To sum up, the late Precambrian banded iron ores should be of metamorphosed volcano-sedimentary type.