The isostatic state of the southern Urals crust

The Uralide orogen, in Central Russia, is the focus of intense geoscientific investigations during recent years. The international research is motivated by some unusual lithospheric features compared with other collisional belts including the preservation of (a) a collisional architecture with an orogenic root and a crustal thickness of 55–58 km, and (b) large volumes of very low-grade and non-metamorphic oceanic crust and island arc rocks in the upper crust of a low–relief mountain belt. The latter cause anomalous gravity highs along the thickened crust and the isostatic equilibrium inside the Uralides lithosphere as well as the overthrust high-metamorphic rocks. The integrated URSEIS '95 seismic experiment provides fundamentally new data revealing the lithospheric architecture of an intact Paleozoic collisional orogen that allows the construction of density models. In the Urals' lithosphere different velocity structures resolved by wide-angle seismic experiments along both the URSEIS '95- and the Troitsk profile. They can be used to constrain lithospheric density models: a first model consists of a deep subducted continental lower crust which has been highly eclogitized at depths of 60–90 km to a density of 3550 kg/m³. The second model shows a slightly eclogitized lower crust underlying the Uralide orogen with a crustal thickness of 60 km. The eclogitized lower crust causes a too-small impedance contrast to the lithospheric mantle resulting in a lack of reflectors in the area of the largest crustal thickness. Both models fit the measured gravity field. Analyzing the isostatic state of the southern Urals' lithosphere, both density models are in isostatic equilibrium.     

金属加工过程中应力状态的分析方法

分析简单地拉伸、压缩和扭转的情况时,应力状态能容易地被确定.但是,实际上在金属加工过程中材料是承受复杂的应力状态,在模具——工件接触面上增加有摩擦力.而且,这些应力和摩擦力一般地沿着接触面变化.准确的计算或预测载荷、力、应力和温度,不但对设计适宜的设备是重要的,而且对研究工艺期间材料的变化过程也是重要的.本文将讨论材料变形过程中所运用的主要分析方法及其优缺点.     

Aluminum position in Rb-feldspar as determined by X-ray photoelectron spectroscopy

Al/Si configurations in some natural and synthetic Rb-feldspars have been examined carefully by EMPA and XPS analyses. Our results indicate that a small amount of H₂O and excess Si and Al are incorporated in hydrothermally synthesized Rb-feldspar. The quantities of excess Al are 0.056 atoms per formula unit and are negatively correlated with those of the Rb, suggesting the presence of excess Al occupying non-tetrahedral sites in feldspar structures. This leads to incorporation of Al(Al₃Si)O₈ endmember into Rb-feldspars, estimated as one appropriate endmember indication for unusual chemistry of feldspars. In addition, Si2p, Al2p and O1s XPS signals of Rb-feldspars shift drastically toward the higher energy side than those of any natural feldspars. These provide conclusive evidence not only for existence of perceptible excess Si and Al, but also for Al at both extra-framework and tetrahedral sites in feldspar structures.     

荆州市地表水沉积物中磷的形态分析

通过对荆州地区主要地表水沉积物中磷的形态分析,揭示了地表水沉积物中不同形态磷的分布特征。结果表明：地表水沉积物中磷主要有交换态磷（Ex—P）、铝磷（Al-P）、铁磷（Fe—P）、闭蓄态磷（Oe—P）、自生钙磷（ACa—P）、碎屑钙磷（De—P）、有机磷（Or—P）7种磷,其中以自生钙磷（ACa—P）、碎屑钙磷（De—P）和有机磷（Or—P）为主,约占总提取磷的95％。自然条件下,绝大部分湖泊的沉积物中95％以上的磷是以生物较难利用的形态存在的,活性磷所占比例较小,不足沉积物总磷的3％;沉积物中铝磷、铁磷、闭蓄态磷、自生钙磷的含量与总磷含量均没有明显相关性。各形态磷的含量分布与水体沉积物的释磷特点及其地球化学循环规律,并受沿岸污水排放及近岸养殖排污等人为活动的影响。     

Soil erosion induced by land use changes as determined by plough marks and field evidence in the Aksum area (Ethiopia)

The aim of the research presented here was to analyse soil erosion in response to changes in agricultural and soil conservation practices throughout history. The Aksum area (Tigray, northern Ethiopia) presents favourable conditions for the development of a long-term approach for assessing soil conservation techniques that have been applied for centuries (i.e., since the Aksumite kingdom, 400 BC to 800 AD). These techniques have been maintained until the present day, and parts of the terraced systems of the area are still in use. During the 1970s, social and political events led to a remarkable change in land use patterns, and large arable areas were converted into grazing land, resulting in a significant increase in soil loss. The rates of soil erosion were evaluated based on analyses of the deep scratches (plough marks) left on stones in the soil by the maresha, the ard plough pulled by oxen used in agricultural practices of the area, and the patinas, varnishes and weathering rinds exposed by soil loss after the abandonment of the fields. The study results show average rates of soil erosion of 2.8 t ha⁻¹ y⁻¹ and 65.8 t ha⁻¹ y⁻¹ for the soil conservation conditions under traditional agriculture (long-term observations) and accelerated erosion after abandonment (short-term observations), respectively. A comparison using recently calibrated erosion evaluation techniques conducted to support the field measurements revealed a close correlation between the calculated and recorded data.     

国家行政征用海域使用权补偿标准法律问题探讨

根据2002年开始实施的《中华人民共和国海域使用管理法》,在海域使用管理法中关于国家行政征用海域使用权、进行清海补偿标准的未作规定,只在渔业管理法中规定参照土地管理法的补偿标准进行补偿,因此,各沿海地区确定征用补偿标准缺乏统一标准。本文根据国家行政征用海域使用权补偿存在的无专门系统的行政征用补偿法、海域征用补偿程序混乱、海域征用补偿救济手段不完善、海域管理适用法律冲突和安置补偿与生产损失补偿混淆在一起等问题进行了探讨,对于完善国家行政征用海域补偿制度提出了法律建议。     

基于不同测试终点的土壤锌毒性阈值及预测模型

采用基质诱导硝化(PNR)、大麦根伸长、西红柿及小白菜生长毒性测试方法,结合Log-logistic模型,对我国16种典型土壤中锌(Zn)的毒性阈值(ECx)进行了测定,同时对Zn毒性与土壤主要影响因子间的量化关系及其预测模型进行了研究.结果表明:我国土壤中Zn的毒性阈值在不同测试物种间存在较大差异,以小白菜、大麦、西红柿及土壤微生物(PNR)测试的EC10均值分别为322,356,336,297mg/kg,以土壤微生物测试最低,以大麦根伸长测定结果最高; EC50均值则分别为: 846,1471,1160,768mg/kg.不同测试方法对土壤中Zn毒性的敏感性顺序为:土壤微生物(PNR)>西红柿>小白菜>大麦,而不同测试方法的稳健性顺序则相反,表明PNR法是土壤Zn毒害最敏感的测试方法,而西红柿则是对土壤Zn污染胁迫最敏感的植物品种; 不同毒性测试结果显示,EC50阈值的测定结果要敏感于EC10,而EC10测定结果的变异系数普遍大于EC50的测定结果.pH值是影响土壤Zn毒性阈值最为重要的因子,而基于土壤pH值,CEC,有机碳含量的归趋化预测模型可以很好地预测土壤中Zn的生态风险阈值.     

Accumulation of heavy metals in two crop seeds due to soil contamination as determined by neutron activation analysis techniques

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Prospective risk in reciprocal translocation heterozygotes at amniocentesis as determined by potential chromosome imbalance sizes. Data of the european collaborative prenatal diagnosis centres

The Data of the European Cooperative Prenatal Diagnosis Laboratories (Boué and Gallano, 1984) of 596 prenatal (amniocyte) diagnoses of familial rep was examined as to relationships between balanced/unbalanced result and ascertainment, carrier parent and chromosome imbalance size (percentage haploid autosome length). Each rearrangement was graphed once with actual (unbalanced result) or potential (normal or balanced result) imbalances plotted with trisomy as the ordinate and monosomy as the abscissa. The graphed data was divided into 15 regions, each of 2·0 per cent trisomy and 0·75 per cent monosomy and the rate of unbalanced pregnancies determined for each region. The highest rates of chromosomally unbalanced progeny (excluding regions with inadequate data) were found closest to the origin (i.e. associated with the smallest imbalances) and these were for ascertainment category 1 (previous rep unbalanced child) 22·3 per cent for maternal carriers and 39 per cent for paternal carriers. Overall in pooled data for this ascertainment category (without reference to the imbalance graphs) there were for paternal carriers 28·6 per cent unbalanced pregnancies and for maternal carriers 18·1 per cent. The graphed data, therefore, revealed the higher rates associated with some of the rep with small potential (combined duplication/ deficiency) imbalances. Lesser rates were observed for ascertainment category 2 (carrier parent with a history of recurrent miscarriage) with overall percentages of imbalanced progeny ranging from 2·7 (paternal carriers) to 4·7 (maternal carriers). Again, higher rates were revealed in graphed data for small potential imbalances. All unbalanced results for this group (ascertainment category 2) plotted in the region closest to the origin with rates of 16 per cent (maternal carriers) and 9·5 per cent (paternal carriers) in this region. Remarkably in both ascertainment groups 1 and 2 there was no significant difference in the size of the imbalanced segments for unbalanced progeny. In ascertainment group 1 this was (dup/def; mean ±S.D.): 1·09±0·77/0·47 ± 0·45 and in ascertainment group 2: 1·09 ±0·80/0·66±0·71. From the graphed data which arguably denote viability relationships, a trisomy was approximately 2·7 times as likely to survive until amniocentesis as a monosomy of equivalent size. It is proposed that given further data, risk estimates could be determined for rep heterozygotes using the present approach where empiric data (from the family history or an analysed series of similar rep) is not available.     

Blank values of trace elements in aerosol filters determined by ICP-MS

Blank values of 30 elements in 19 different filter types from Gelman, Millipore, Nuclepore and Whatman have been compared. The filter media were extracted with dilute nitric acid and the element contents determined by ICP-MS. Large differences in blank values were observed between different filter materials. Glass fiber filters showed high blank values for a number of elements, whereas PTFE filters were generally the cleanest. However, most filter types showed high blank values of one or more elements of environmental interest.     

The influence of outliers on results of wet deposition measurements as a function of measurement strategy

The results of a wet deposition monitoring experiment, carried out by eight identical wet-only precipitation samplers operating on the basis of 24 h samples, have been used to investigate the accuracy and uncertainties in wet deposition measurements. The experiment was conducted near Lelystad, The Netherlands over the period 1 March 1983–31 December 1985.By rearranging the data for one to eight samplers and sampling periods of 1 day to 1 month both systematic and random errors were investigated as a function of measuring strategy. A Gaussian distribution of the results was observed. Outliers, detected by a Dixon test (a = 0.05) influenced strongly both the yearly averaged results and the standard deviation of this average as a function of the number of samplers and the length of the sampling period. The systematic bias in bulk elements, using one sampler, varies typically from 2 to 20% and for trace elements from 10 to 500%, respectively. Severe problems are encountered in the case of Zn, Cu, Cr, Ni and especially Cd. For the sensitive detection of trends generally more than one sampler per measuring station is necessary as the standard deviation in the yearly averaged wet deposition is typically 10–20% relative for one sampler. Using three identical samplers, trends of, e.g. 3% per year will be generally detected in 6 years.     

祁连地块中元古代火山岩地球化学特征

分布于祁连造山带中祁连地块东端北缘的中元古代皋兰岩群火山岩为一套以基性—中基性—中酸性火山岩组合的浅变质岩,通过岩石组合、岩石化学、稀土及微量元素地球化学的综合分析研究,认为该套火山岩产于陆缘弧及弧后活动盆地的构造环境。     

次溴酸盐氧化法测定水中NH4-N的改进方法

次溴酸盐氧化法测定水中NH4-N存在较严重的、不易消除的干扰.本文认为这是玻璃内部所含的杂质氮化物(MmNn)所致.实验将氧化反应改在塑料容器中进行,克服了干扰,降低了空白值,改善了线性关系.空白吸光度降为0.020左右,校准曲线的相关系数能达到0.999 8～0.9999 6.改进方法具有较好的精密度和准确度,实测样品的相对标准偏差为0.68%,加标回收率为94.6%～96.8%.     

土壤溶液性质对Zn的形态变化及其微生物毒性的影响

采集了我国具有代表性的12种不同性质土壤,利用基础诱导硝化(SIN)方法测定了不同土壤中锌的微生物毒性阈值,同时利用850离子色谱仪与WHAM6.0模型,测定了溶液不同阴离子组成及自由Zn2+含量,建立了基于不同土壤性质与溶液离子的土壤中Zn毒性预测模型.结果表明,基于SIN测定的不同土壤Zn微生物毒性阈值在不同土壤间有显著差异,其中EC50从196mg/kg至1310mg/kg;EC10值从48mg/kg增加至682mg/kg,不同土壤EC50与EC10的最大值与最小值的比例分别达到了6.68及14.3倍,表明土壤性质对Zn的微生物毒性有非常显著的影响;基于SIN的Zn的毒性阈值ECx(x=10,50)与溶液自由Zn2+浓度的负对数p(Zn2+)间呈正相关关系,表明随着土壤溶液中自由Zn2+值的升高,Zn的毒性逐渐增加.土壤pH值、OC、CEC、F-、Cl-、Ca2+及Mg2+与Zn的毒性阈值ECx(x=10,50)及p(Zn2+)呈正相关关系,其中土壤pH值为最重要的影响因子,偏相关系数均达到极显著水平(P<0.01),其次为OC、CEC及F-,ECx与溶液中NO3-, SO42-呈负相关关系.基于不同主控因子的土壤中Zn毒性阈值(ECx)及P(Zn2+)的预测模型表明,pH值、OC、CEC、F- 四个变量因子分别解释了log(EC50)、log(EC10)及p(Zn2+)预测模型变异的89.9%、81.2%和92.3%.     

煤炭全成本核算改革方向渐明

生态环境的保护与资源能源的节约相互交错，考验着政府与企业的智慧。在“十一五”规划开局之年的节能与脱硫浪潮中，煤炭工业发展中存在的诸多矛盾浮出了水面。近期，无论是政府还是民间组织，都对煤炭工业可持续发展投入了极大关注。其中，关于煤炭全成本核算的讨论尤为热烈，并已形成一些初步共识。     

Zeta电位法研究除草剂在土壤胶体中的吸附

应用Zeta(ζ)电位法研究比较了扑草净和扑灭通在4种土壤胶体中的吸附.结果表明,当带有正电荷的除草剂在负电荷土壤表面吸附后,土壤表面的ζ电位有所增加,甚至使ζ电位从负转变成正.通过零电荷点计算得到除草剂和土壤之间的吸附常数和Gibbs自由能,并由经典的振荡平衡法得到相近结果.     

硫酸改性火山石对水中左氧氟沙星的吸附研究

利用硫酸改性火山石对水中左氧氟沙星进行吸附,通过XRD、SEM和FT-IR等手段对吸附剂进行表征,考察了吸附剂投加量、初始pH、共存盐类和吸附时间等因素对吸附效果的影响,并对吸附动力学和吸附等温线进行拟合。结果表明：天然火山石经硫酸改性后孔隙结构更加丰富,抗pH和共存盐类干扰能力较强;当吸附剂投加量为25 g/L、pH为3.0、温度20℃、左氧氟沙星初始浓度为50 mg/L、吸附平衡时间为120 min时,改性火山石对左氧氟沙星吸附去除率可达99.46%;天然和改性火山石的吸附过程符合伪一级和伪二级动力学;在20℃时,Langmuir等温方程式能更好地描述天然火山石对左氧氟沙星的吸附行为,而改性火山石对左氧氟沙星的吸附更符合Freundlich等温吸附模型;吸附过程同时包括物理吸附和化学吸附。     

The state of ISO 14001 certification in Greece

Consideration is given to the evaluation of the present state of ISO 14001 implementation, as determined by the penetration of certifications and of certification agencies within industries in Greece. After identifying nearly all certified enterprises by the end of year 2004, a large cluster of 153 enterprises (circa 80.5% of all certifications), for which published information was available, are analysed. The data used concern both individual enterprises and demographic averages for respective industrial activities (determined by industry and sector). Analysis reveals ISO 14001 to be mainly accepted in manufacture, with both services and commerce to seriously lag behind. Analysis by sector, a more detailed activity indicator, shows marked ISO 14001 penetration differences between sectors, suggesting the influence of activity-related practices as a major certification driver. Evidence is also provided for the existence of a sector-related certification culture associating ISO 14001 certification decisions with ISO 9000 sector penetration levels. In addition, relatively larger enterprises, but not necessarily more profitable, seem to seek ISO 14001 certification in most sectors. Finally, analyses of all main certification agencies identified in Greece demonstrate that, with one exception, the choice of agency is mostly independent of industrial activity as well as certified enterprise size and profitability.