铝土矿选尾矿制备烧结砖的试验研究

综合分析尾矿利用的最新成果,分析了铝土矿选尾矿的成分特点,通过正交试验优化制备烧结砖的原料配比:铝土矿选尾矿84%、粉煤灰10%、污泥6%。在此配比下,按水固比0.24、烧成温度1100℃、保温时间60 min,制得烧结砖的性能均符合GB5101—2003《烧结普通砖》中MU20级的要求,该"全废渣"制备烧结砖的方法符合循环经济的发展要求。     

铁尾矿生产烧结砖过程中的一些问题分析

铁尾矿是一种堆存量和年排放量最大的废渣,它的循环利用有很好的经济价值。为此介绍了利用安徽某铁尾矿生产烧结砖的生产线,分析了在生产过程中出现的一些问题,提出一些相应的解决途径。     

关于废渣砖与高掺量粉煤灰烧结砖的界定

目前,对于废渣砖和高掺量粉煤灰烧结砖掺量比的评价指标,既有体积百分比,又有质量百分比,二者同时应用。这对废渣砖和高掺量粉煤灰烧结砖的规范化管理及生产工艺技术的研究产生了不利影响,也不利于对新型墙体材料的规范化管理。本文就如何界定废渣砖与高掺量粉煤灰烧结砖进行了讨论,并提出应以质量比界定废渣砖和高掺量粉煤灰烧结砖。     

鄂西铁尾矿烧结砖的烧结过程及机理

以鄂西赤铁矿尾矿为主要原料制备铁尾矿烧结砖,通过综合差热分析（TG DSC）、X射线衍射分析（XRD）和扫描电子显微镜分析（SEM）,研究了铁尾矿烧结砖的烧结过程及烧结机理.结果表明：铁尾矿烧结砖的烧结过程分为干燥预热、加热、烧成及冷却4个阶段.铁尾矿烧结砖烧结初期以固相表面的扩散传质为主,烧结中后期以熔融液相作用下的固体颗粒重排和塑性流动传质为主.熔融液相对铁尾矿砖坯的烧结致密及固相反应起到重要的促进作用.     

废渣烧结砖发展的现状与建议

1　废渣烧结砖发展存在的问题　　目前,不少制砖企业仅从自身利益出发,为降低产品成本,对废渣烧结砖中废渣掺量仅满足国家减免税收的最低要求就可以了,致使工业废渣在烧结砖中的综合利用的整体水平不高,在废渣资源丰富的地区的中小砖厂,采用自然干燥的废渣砖中废渣掺兑比一般只有30%左右。这一状况如不尽快改变,将会对烧结砖行业的技术进步、产品结构调整起到很大的制约作用。　　从20世纪60年代初至80年代末近20年间,是利用工业废渣制砖的第一阶段即初级阶段。这一阶段主要是利用废渣中的热值将废渣作为内掺燃料,以节约煤炭,同时起到了节约…     

利用铁尾矿生产烧结砖的实验研究

用正交试验法确定了利用铁尾矿作原料研制生产烧结砖的配方，并对铁尾矿烧结砖影响因素进行分析讨论，制成强度等级Ｍｕ１５和Ｍｕ１０的铁尾矿砖。     

利用金尾矿渣生产烧结空心砖的试验

金尾矿渣是金矿采选生产过程中产生的一种工业废渣，这种工业废弃物不仅占用大量良田好土，而且还严重污染周围环境。我们将山东省某金矿的金尾矿作试验，运用页岩做胶给剂，采用传统的烧结砖生产工艺和真空挤出成型等方法，试制出金尾矿渣掺量达到40％的金尾矿页岩烧结定心砖。这项研究成果不仅为金尾矿找到了一条较好的利用途径，而且还增加了一种新型墙体材料，具有化害为利、变废为宝的作用。     

利用贵州卡琳型金矿尾矿制备烧结砖的研究

研究了贵州卡琳型金矿尾矿的化学成分、物相、浸出毒性、放射性和可塑性等性能,并利用该金尾矿与页岩混合制备烧结砖.研究结果表明,该金尾矿可以制备出抗压强度超过20 MPa,石灰爆裂和泛霜都很轻微的烧结砖     

利用金尾矿渣生产烧结空心砖的试验

金尾矿渣是金矿采选过程中产生的一种工业废渣，这种工业废弃物不仅占用大量良田好土,而且还严重污染周围环境。我们以山东省某金矿的金尾矿作为试验对象，利用页岩做胶结剂，采用传统的烧结砖生产工艺和真空挤出成型等方法，试制出金尾矿渣掺量达到40％的金尾矿面岩烧结空心砖。这项研究成果不仅为金尾矿找到了一条较好的利用方法，而且又增加了一种新型墙体材料，具有化害为利、变废为宝的作用，有很好的推广价值。     

珍珠岩尾矿烧结砖的实验研究

以珍珠岩尾矿动原料进行烧结砖实验研究,发现该砖具有轻质、高强及保温等特声、。珍珠岩尾矿烧结砖的生产有利于环境治理,又具有较为显著的经济效益。     

Heat and cold stresses in different climate zones across China: A comparison between the 20th and 21st centuries

Summer and winter discomfort in terms of heat and cold stresses in the nine major architectural climate zones and sub-zones across China in the 21st century were investigated using predictions from general circulation models for the low and medium emissions scenarios. For the six severe cold and cold climate zones in the north, reductions in cumulative cold stress outweighed the increase in cumulative heat stress resulting in an overall decreasing trend in the annual cumulative stress, and vice versa for the other three warmer climate zones in the south. Compared with the 20th century, significant reduction in the cumulative cold stress was observed across the six zones in severe cold and cold climates, ranging from 15.8 in cold-III to 42.3 in severe cold-II. There were modest increases in the cumulative heat stress from 0.3 in cold-II to 12.3 in cold-III. For the warmer climates in the south, reduction in cumulative cold stress ranged from 7.6 in hot summer and warm winter (HSWW) to 10.3 in hot summer and cold winter, while cumulative heat stress increased from 9.9 in the mild zone to 30.6 in HSWW. A reduction in cold stress would result in less winter heating and an increase in heat stress more cooling requirement.     

Health assessment of artisanal gold miners in Indonesia

Small scale miners use mercury to extract gold from ore in many countries. An environmental and health assessment was performed in Indonesia in two regions, Galangan in Central Kalimantan and Talawaan in Northern Sulawesi. The environmental assessment showed severe mercury contamination of the sediments, and increased mercury levels in local fish. For the health investigation 281 volunteers were recruited and examined by a standardized questionnaire, a neurological examination and neuro-psychological tests. A medical score was used consisting of significant factors of mercury intoxication. Mercury exposed workers showed typical symptoms of mercury intoxication, such as movement disorders (ataxia, tremor, dysdiadochokinesia, etc.). Blood, urine and hair samples were taken from any participant and analyzed for mercury. The mercury concentration in the biomonitors was high, partly extreme high in the working population, increased in the population living in the same habitat and low in the control group. By a standard protocol which includes a combination of threshold values of mercury in the biomonitors and a medical sum score the diagnosis of chronic mercury intoxication was made for highly burdened workers (amalgam smelters) in 55% in Sulawesi and in 62% in Kalimantan. Less exposed mineral processors and the general population in the mining areas were also intoxicated to a high percentage.     

Urban environmental mercury in Changchun, a metropolitan city in Northeastern China: source, cycle, and fate

Mercury concentrations in each environmental compartment in Changchun City had obvious spatial and temporal trends. Particulate Hg (HgP) and total gaseous mercury (TGM) concentrations in air, total Hg (HgT) concentrations in precipitation and ratios of HgP to HgT (total Hg in air) in the atmosphere in heating season were higher than those in non-heating season, which resulted from civil heating. In contrast, reactive Hg (HgR) concentrations in precipitation were higher in non-heating season than those in heating season. TGM and SO2 in air had good agreement. HgP concentrations in the atmosphere were correlated with HgT concentrations in precipitation. Based on Hg concentrations in each environmental compartment, Hg exchange fluxes between environmental interfaces were estimated. Only 11.6% of Hg, emitted from coal combustion, deposited into land surface in urban district and the rest part participated in regional or global cycle, so urban district was the source of Hg global and regional cycle. Net fluxes of Hg into land surface and water were 34.26 kg year(-1) and 0.051 kg year(-1), respectively, which were clearly accumulated in the water and soil. Therefore considering urban local Hg cycle, each environmental compartment of urban ecosystem (water, air and soil) was the sink of Hg.     

Impacts of climate change on phosphorus loading from a grassland catchment: Implications for future management

Dynamic modelling was used to quantify the impact of projected climate change, and potential changes in population and land use, on phosphorus (P) export from a sub-catchment in SW Ireland using the Generalised Watershed Loading Functions (GWLF) model. Overall the results indicated that the increase in annual total phosphorus loads attributable to climate change was greater than that from either population or land use change, and therefore that future climate variability will pose an increasingly significant threat to the successful long-term implementation of catchment management initiatives. The seasonal pattern in projected P export mirrored changes in streamflow, with higher rates between January and April and lower rates in summer. The potential reduction in export in summer was, however, negated when increases in population were included in simulations. A change in the slurry spreading period from that stipulated in national regulations to the months between April and September could potentially mitigate against future increases in dissolved P export in spring. The results indicate that projected changes in climate should be included when undertaking modelling exercises in support of decision making for catchment management plans.     

Cyanobacteria and earthy/musty compounds found in commercial catfish (Ictalurus punctatus) ponds in the Mississippi Delta and Mississippi--Alabama Blackland Prairie

The compounds responsible for earthy and musty "off-flavors" in farm-raised channel catfish (Ictalurus punctatus) in the southeastern United States of America are geosmin and 2-methylisoborneol (MIB), respectively. These compounds are produced by certain species of cyanobacteria (blue-green algae) that grow in the aquaculture ponds. Previous research has focused on the species of cyanobacteria found in catfish ponds in west Mississippi (the leading region of catfish production in the USA), while the species responsible for earthy/musty off-flavors in catfish produced in the Mississippi-Alabama Blackland Prairie (MABP) region (second greatest region of catfish production) have not been described. We examined water samples from commercial catfish ponds in both regions to contrast the different types of cyanobacteria and assess the prevalence of geosmin and MIB. Results established that filamentous cyanobacteria are more common in west Mississippi compared to the MABP region. Also, the MIB-producing cyanobacterium Oscillatoria perornata is present in catfish ponds in both geographic locations, and geosmin is more prevalent in catfish ponds in the MABP region than in west Mississippi.     

在革新与现代主义之间:夏昌世与德国(英文)

夏昌世,中国第一代建筑师,1920年代在德国卡尔斯鲁厄留学。1932年,他在图宾根完成了博士论文之后重返祖国。1940年代后期,他在广州成为教授,1973年与妻子一同重返德国,并在那里生活直至1996年逝世。他的设计方法不仅受到那个时代欧洲现代主义运动氛围的熏陶,还来自他对中国传统景观与建筑艺术历史的研究。他是引领岭南区域形成岭南学派建筑的主导力量之一。同时,作为一建筑学教授,他在广州培养了新一代青年建筑师。     

Heavy metal contaminants in Red Pandora (Pagellus erythrinus) tissues from the Eastern Aegean Sea, Turkey

Heavy metal contents were investigated in different organ tissues of Red Pandora (Pagellus erythrinus) from the eastern Aegean Sea between May 1996 and July 1998. The concentrations of mercury in the muscle tissue ranged between 16 and 716, in liver 125-5451, in gonad 2.0-1858; cadmium in muscle nd-9.6, in liver 1.4-2245, in gonad nd-192; lead in muscle nd-1397, in liver 112-8311, in gonad nd-2927; zinc in muscle 1352-6693, in liver 2710-78705, in gonad 7273-168655; copper in muscle nd-383, in liver nd-21986, in gonad nd-20499 (microg/kg wet weight). The highest concentrations were generally found in the Southern Aegean Sea. All metal levels in muscle tissues are lower than the limits of European Dietary Standards and Guidelines. The metals ratios between liver and muscle indicated that the liver accumulated higher levels of metals than the muscle tissues. The bioaccumulation factor (BAFs) of metals was measured in muscle, liver and gonads. BAFs among the analysed elements showed the descending orders as Zn>Cu>Cd>Pb for muscle and gonads and Cd>Zn>Cu>Pb for liver.     

Use of iodide to enhance the phytoextraction of mercury-contaminated soil

Low bioavailability of mercury (Hg) in soil is a restricting factor in phytoextraction of Hg-contaminated soil. Iodide is known to mobilize Hg in soil and, therefore, the aim of this study was to investigate the possibility to use iodide to increase phytoextraction of Hg. The sensitivity of willow to iodide was investigated in both hydroponics with 0-10 mM KI and in soil with 0.2 and 1 mM KI addition. The capacity to accumulate HgI(2) was compared with that of Hg(NO(3))(2) in hydroponics. Soil extractions with 0-2 mM KI were used to study mobilization of Hg in aged Hg-spiked soil. Additions of KI (0.2-1 mM) were used in pot tests with aged Hg-spiked soil as well as in field trials in an industrial Hg-contaminated soil to study whether iodide addition increased the accumulation of Hg from contaminated soil and the translocation of Hg to the shoots. The total Hg contents in plants, soils and extracts were analyzed by CVAAS. The results showed that too high KI concentration was toxic to plants. Moreover, KI was toxic to plants at lower concentrations in hydroponics than in soil additions. KI (85 microM) in hydroponics gave 50% growth decrease in terms of dry weight of shoot biomass, whereas 0.2 mM KI in soil addition could be tolerated by the plant without growth disturbance. Willow accumulated Hg from HgI(2) solution slower than that from Hg(NO(3))(2) solution. KI mobilized Hg in contaminated soil and thereby increased the bioavailability of Hg in soil. Up to 1 mM KI addition increased the Hg concentrations to about 5, 3 and 8 times, respectively, in the leaves, branches and roots. However, the Hg translocation to the shoots did not show an increase with KI addition. Only less than 1% of the total Hg accumulated in the plant was distributed in the shoots. We may conclude that iodide addition enhances the phytoextraction of Hg, however, the translocation of Hg to the shoots is still too low and therefore it will not be realistic to use this method for phytoextraction of Hg-contaminated soil in practice.     

Chernobyl fallout in the uppermost (0-3 cm) humus layer of forest soil in Finland, North East Russia and the Baltic countries in 2000--2003

The situation resulting from the Chernobyl fallout in 1987 was compared to that in 2000--2001 in Finland and NW Russia and that in 2003 in the Baltic countries. 786 humus (0-3 cm layer) samples were collected during 2000--2001 in the Barents Ecogeochemistry Project, and 177 samples in the Baltic countries in 2003. Nuclides emitting gamma-radiation in the 0-3 cm humus layer were measured by the Radiation and Nuclear Safety Authority-STUK in Finland. In 1987 the project area was classified by the European Commission into four different fallout classes. 137Cs inventory Bg/m2 levels measured in 2000--2003 were compared to the EU's class ranges. Fitting over the whole project area was implemented by generalizing the results for samples from the Baltic countries, for which Bq/m2 inventories could be calculated. A rough estimation was made by comparing the mass of organic matter and humus with 137Cs concentrations in these two areas. Changes in 137Cs concentration levels are illustrated in both thematic maps and tables. Radionuclide 137Cs concentrations (Bq/kg d.w.) were detected in the humus layer at all the 988 sampling sites. 134Cs was still present in 198 sites 15 years after the nuclear accident in Chernobyl. No other anthropogenic nuclides emitting gamma-radiation were detected, but low levels of 60Co, 125Sb and 154Eu isotopes were found in 14 sites. Fifteen years after the Chernobyl accident, the radioactive nuclide 137Cs was and still is the most significant fallout radionuclide in the environment and in food chains. The results show that the fallout can still be detected in the uppermost humus layer in North East Europe.     

从息壤到土工合成材料

据说息壤是一种可以自生自长的土,远古的先民们曾用它防治洪水。对这种传说中的岩土材料进行了考据,根据河狸坝与我国古代的治河工程,指出所谓息壤应当是古代人们利用草、木、竹、石、土创造出来的加筋土,用以拦截阻挡洪水。秦汉时期称为茨防,宋代称为埽工。回顾了我国土工加筋及其在河工中应用的长远历史,指出土工合成材料在保护环境、保护资源和我国经济可持续发展中应用的广阔前景。