Foundations of petroleum prediction based on the activation of geochemical processes by direct current

Petroleum prediction in local objects and the applicability of geologic environment parameters in this regard are considered. The proposed guidelines for petroleum potential prediction are based on the analysis of the distribution of typomorphic epigenetic multivalent elements loosely fixed in rocks before and after electric current treatment. The advantage of geoelectrochemical methods providing data on the chemical composition of above-productive deposits is demonstrated.     

海洋生态监测站建设指南的标准化构建

为指导我国海洋生态监测站的建设,加速推进海洋生态系统长期、定点、持续监测的网络化、规范化建设进程,本研究提出了海洋生态监测站建设指南标准化构建的总体设计理念。通过分析国内外各类长期生态监测网络的建设现状和经验,论述了我国海洋生态系统长期定位监测的研究现状和存在的问题,以及进行海洋生态监测站建设指南构建的重要意义、构建原则、构建目标,并且对海洋生态监测站建站的原则、流程、建设内容与运行维护和管理等方面提出了建设指导,以促进海洋生态监测及其网络体系的健康有序发展,提升海洋生态系统监测预警能力和研究水平。     

半参数估计与LS估计的有效性比较

建立半参数回归模型,将系统误差加入,推导出了模型正则化矩阵时参数平差的计算方法,并用直接法得到了参数、非参数的估计量,在MSE准则下与最小二乘估值(简称LS估值)进行比较,证明了半参数估值的有效性。     

Guidelines for sampling bedload transport with minimum uncertainty

The stability of river channels and their suitability as habitat for aqueous organisms is strongly controlled by the rate of bedload transport. Quantification of bedload transport rates in rivers is difficult, not only because of the temporal variation in transport, but also because of the cross‐channel variation in transport. The objectives of this study were: (i) to determine the effect of cross‐channel variation in bedload transport on the uncertainty of width‐integrated transport rates; and to use this knowledge (ii) to improve guidelines for bedload sampling. This was done through a thorough statistical evaluation of stochastic and systematic uncertainties involved in bed‐load transport measurements. Based on this evaluation, new guidelines are presented for determination of the number of samples and sampling positions across the channel that are required for bedload measurements in several types of sand‐bed rivers and gravel‐bed rivers. The guidelines relate to bedload measurements made with pressure‐difference (Helley‐Smith type) samplers that require numerous bedload samples of short duration at several positions across the channel. The results show that generally more sampling positions across the channel are required in gravel‐bed rivers than in sand‐bed rivers. For gravel‐bed rivers with unknown cross‐channel distribution of transport, at least 10 sampling positions are recommended, whereas for most sand‐bed rivers five positions suffice. In addition, at least 12 short‐duration samples are required at each position to obtain bedload estimates with uncertainties below 20%. If the same level of uncertainty is desired in the case of high spatial and temporal variation in transport rates, the number of short‐duration samples needed per sampling position increases to 40.     

Spatial Thinking Concepts in Early Grade-Level Geography Standards

ABSTRACT

Research in the cognition and learning sciences has demonstrated that the human brain contains basic structures whose functions are to perform a variety of specific spatial reasoning tasks and that children are capable of learning basic spatial concepts at an early age. There has been a call from within geography to recognize research on spatial cognition in a meaningful way in primary school curriculum. This article utilizes the spatial thinking taxonomy proposed by Gersmehl and Gersmehl (2006) to examine to the extent to which spatial thinking concepts are being practiced in U.S. schools. The National Geography Standards and forty-nine state social studies or geography standards are examined. Using standards as a measure of geography content, it is concluded that while some of spatial thinking concepts appear often in curriculum, others are largely absent. Designing geography standards that address the findings of spatial cognition research may serve as a means of improving geography instruction.     

城市商业中心特色综合体研究——朝阳天马集团卫生学校地块商住综合体设计

从商业策划的角度介绍了朝阳天马集团卫生学校地块商住综合体设计的总体构思和特点,该项目欲在朝阳最重要的朝阳大街上建造地产的新标志,使之成为城市的重要节点。     

Spatial patterns of chemical contamination (metals, PAHs, PCBs, PCDDs/PCDFS) in sediments of a non-industrialized but densely populated coral atoll/small island state (Bermuda)

There is a recognized dearth of standard environmental quality data in the wider Caribbean area, especially on coral atolls/small island states. Extensive surveys of sediment contamination (n = 109 samples) in Bermuda revealed a wide spectrum of environmental quality. Zinc and especially copper levels were elevated at some locations, associated with boating (antifouling paints and boatyard discharges). Mercury contamination was surprisingly prevalent, with total levels as high as 12 mg kg⁻¹ DW, although methyl mercury levels were quite low. PAH, PCB and PCDD/PCDF contamination was detected a several hotspots associated with road run-off, a marine landfill, and a former US Naval annexe. NOAA sediment quality guidelines were exceeded at several locations, indicating biological effects are possible, or at some locations probable. Overall, and despite lack of industrialization, anthropogenic chemicals in sediments of the atoll presented a risk to benthic biodiversity at a number of hotspots suggesting a need for sediment management strategies.     

Toxicities of antifouling biocide Irgarol 1051 and its major degraded product to marine primary producers

Irgarol 1051 (2-methythiol-4-tert-butylamino-6-cyclopropylamino-s-triazine) is an algaecide commonly used in antifouling paints. It undergoes photodegradation which yields M1 (2-methylthio-4-tert-butylamino-6-amino-s-triazine) as its major and most stable degradant. Elevated levels of both Irgarol and M1 have been detected in coastal waters worldwide; however, ecotoxicity effects of M1 to various marine autotrophs such as cyanobacteria are still largely unknown. This study firstly examined and compared the 96 h toxicities of Irgarol and M1 to the cyanobacterium Chroococcus minor and two marine diatom species, Skeletonema costatum and Thalassiosira pseudonana. Our results suggested that Irgarol was consistently more toxic to all of the three species than M1 (96 h EC50 values: C. minor, 7.71 microug L(-1) Irgarol vs. > 200 microg L(-1) M1; S. costatum, 0.29 microg L(-1) Irgarol vs. 11.32 microg L(-1)M1; and T. pseudonana, 0.41 microg L(-1) Irgarol vs. 16.50 microg L(-1)M1). Secondly, we conducted a meta-analysis of currently available data on toxicities of Irgarol and M1 to both freshwater and marine primary producers based on species sensitivity distributions (SSDs). Interestingly, freshwater autotrophs are more sensitive to Irgarol than their marine counterparts. For marine autotrophs, microalgae are generally more sensitive to Irgarol than macroalgae and cyanobacteria. With very limited available data on M1 (i.e. five species), M1 might be less toxic than Irgarol; nonetheless this finding warrants further confirmation with additional data on other autotrophic species.     

某农药厂场地土壤地下水污染修复指导值探讨

参考加拿大Alberta SGRG层次性分析模式,选择其中Tier 1、Tier 2两层次进行分析,结合适合我国的参数计算出了某农药厂土壤地下水中的有机污染物1,2-二氯乙烷、1,2-二氯丙烷修复值,得到了通用的Tier 1修复指导值分别为:渗坑土壤中1,2-二氯乙烷6.2μg/kg,1,2-二氯丙烷67μg/kg;场地地下水中1,2-二氯乙烷、1,2-二氯丙烷均为5μg/L。在此基础上,结合实地调查获取场地参数,利用Tier 2评价对指导值进行修正,确定了场地最终修复目标值:渗坑土壤中1,2-二氯乙烷为11μg/kg,1,2-二氯丙烷为45μg/kg;地下水中1,2-二氯乙烷、1,2-二氯丙烷仍为5μg/L。各途径修复值的改变较符合层次性评价的理论,即Tier 2修复值较Tier 1宽松;但1,2-二氯丙烷的保护DUA途径修复值较Tier 1更加严格,这是由于场地特定条件造成的。     

Heavy metal pollution and assessment in the tidal flat sediments of Haizhou Bay,China

The heavy metal inventory and the ecological risk of the tidal flat sediments in Haizhou Bay were investigated. Results show that the average concentrations of heavy metals in the surface sediments exceeded the environment background values of Jiangsu Province coastal soil, suggesting that the surface sediments were mainly polluted by heavy metals (Cd, Cr, Cu, Mn, Pb and Zn). In addition, the profiles of heavy metals fluxes can reflect the socio-economic development of Lianyungang City, and heavy metals inputs were attributed to anthropogenic activities. Cr, Cu, Pb and Zn were mainly present in the non-bioavailable residual form in surface sediments, whereas Cd and Mn were predominantly in the highly mobile acid soluble and reducible fractions. The ecological risk of the polluted sediments stemmed mainly from Cd and Pb. According to the Sediment quality guidelines (SQGs), however, the adverse biological effects caused by the heavy metals occasionally occurred in tidal flat.