云南兰坪县城滑坡地质特征及其成因分析

2000年9月兰坪县城发生特大型山体滑坡,造成重大经济损失,采取挡墙、抗滑桩等措施后,北部边坡局部基本稳定,南部依见明显新变形,2010~2013年尤甚。基于滑坡现状特征及区域地质环境条件分析,提出了以隐伏断裂(F2)为界将滑坡区重新分块,能够合理反映滑坡的变形破坏特征,并为类似滑坡地质勘察加强针对隐伏断裂的影响分析具有重要的借鉴意义。通过分析滑坡体地质及变形破坏特征,认为滑坡的成因主要受控于滑坡区发育的不利岩性条件及地质结构面,水~岩作用是导致岩体崩解破坏诱发滑坡的主要因素。     

Acid-catalyzed heterogeneous reaction of 3-methyl-2-buten-1-ol with hydrogen peroxide

Acid-catalyzed heterogeneous oxidation with hydrogen peroxide(H2O2) has been suggested to be a potential pathway for secondary organic aerosol(SOA) formation from isoprene and its oxidation products. However, knowledge of the chemical mechanism and kinetics for this process is still incomplete. 3-Methyl-2-buten-1-ol(MBO321), an aliphatic alcohol structurally similar to isoprene, is emitted by pine forests and widely used in the manufacturing industries. Herein the uptake of MBO321 into H2SO4–H2O2mixed solution was investigated using a flow-tube reactor coupled to a mass spectrometer. The reactive uptake coefficients(γ) were acquired for the first time and were found to increase rapidly with increasing acid concentration. Corresponding aqueous-phase reactions were performed to further study the mechanism of this acid-catalyzed reaction. MBO321 could convert to 2-methyl-3-buten-2-ol(MBO232) and yield isoprene in acidic media. Organic hydroperoxides(ROOHs) were found to be generated through the acid-catalyzed route,which could undergo a rearrangement reaction and result in the formation of acetone and acetaldehyde. Organosulfates, which have been proposed to be SOA tracer compounds in the atmosphere, were also produced during the oxidation process. These results suggest that the heterogeneous acid-catalyzed reaction of MBO321 with H2O2 may contribute to SOA mass under certain atmospheric conditions.     

生态文明视域下技术创新、产业升级与污染控制的互作效应研究

随着工业化和城市化进程的加快,环境污染问题已成为生态文明建设亟需解决的重要问题.生态文明是对农业文明和工业文明的超越,代表了更为高级的人类文明形态.生态文明建设是体现经济、社会、环境可持续发展以及人与自然和谐共存的重要战略决策.本文从环境质量改善及污染控制的有效性方面,深入剖析了技术创新、产业升级与污染控制之间的互作效应关系,并探讨了有效的实现方式.研究结果旨在为生态文明建设的有效实施和顺利展开提供借鉴和参考价值.     

SDBS/Na+对红壤胶体悬液稳定性的影响

土壤中普遍存在的有机污染物和无机离子与土壤胶体颗粒的相互作用深刻地影响着土壤中一系列物理、化学和生物学过程.选取红壤胶体作为对象,利用动态光散射技术研究了不同浓度十二烷基苯磺酸钠(SDBS)和Na+作用下红壤胶体颗粒的凝聚过程,并结合体系的pH和Zeta电位分析了SDBS/Na+与土壤胶体颗粒相互作用的机制.结果表明:①相同浓度Na+作用下,随着SDBS浓度的升高,土壤胶体悬液稳定性增强.例如120 mmol·L-1Na+作用下,随着SDBS浓度从0 mmol·L-1升高到10 mmol·L-1,凝聚体有效粒径从702 nm下降至193 nm,总体平均凝聚速率从28.6 nm·min-1减小到3.36 nm·min-1;②相同浓度SDBS作用下,随着Na+浓度的升高,体系Zeta电位绝对值显著降低,凝聚体有效粒径逐渐增大,凝聚速率逐渐加快;③仅SDBS作用下,随着SDBS浓度的升高,体系Zeta电位绝对值从47.6 mV增加到62.2 mV,体系pH从6.17升高到6.76,但均小于土壤胶体悬液本身的pH(6.89).因此,SDBS通过疏水作用和静电作用吸附于土壤胶体颗粒表面,增加了颗粒表面的负电荷数量,降低了作用于胶体颗粒表面的有效Na+浓度(SDBS疏水长链的空间阻碍和高浓度SDBS所形成的胶束结构对Na+的吸附),使得胶体悬液稳定性增强,需要添加更多的Na+才能发生凝聚.     

Zn2+对铁氧化物吸附苄嘧磺隆的影响

研究2种人工合成的铁氧化物对磺酰脲类除草剂--苄嘧磺隆(bensulfuron-methyl,BSM)的吸附,以及Zn2 对供试样品吸附苄嘧磺隆的影响.实验结果表明,用Langmuir、Freundlich、Temkin等方程对供试样品加入Zn2 后吸附BSM的数据进行了拟合,发现供试样品吸附苄嘧磺隆的等温曲线较好地符合Freundlich方程.加入Zn2 后,铁氧化物吸附苄嘧磺隆的量较未加Zn2 有较大幅度的增加,但在苄嘧磺隆的平衡质量浓度较低(＜4 mg/L)时,氧化物吸附苄嘧磺隆的量不随Zn2 浓度的增加而增加;在苄嘧磺隆的平衡质量浓度较高(＞6 mg/L)时,氧化物吸附苄嘧磺隆的量随Zn2 浓度的增加而增加.这可能是Zn2 和苄嘧磺隆被吸附时存在竞争和协同交互作用的结果.     

STABLE ISOTOPE CHARACTERIZATION OF THE IMPACTS OF ARTIFICIAL GROUND WATER RECHARGE1

ABSTRACT: Stable isotopes of deuterium and oxygen-18 of surface and ground water, together with anion concentrations and hydraulic gradients, were used to interpret mixing and flow in ground water impacted by artificial recharge. The surface water fraction (SWF), the percentage of surface water in the aquifer impacted via recharge, was estimated at different locations and depths using measured deuterium/hydrogen (DIH) ratios during the 1992, 1993, and 1994 recharge seasons. Recharged surface water completely displaced the ground water beneath the recharge basins from the regional water table at 7.60 m to 12.16 m below the land surface. Mixing occurred beneath the recharge structures in the lower portions of the aquifer (>12.16 m). Approximately 12 m down-gradient from the recharge basin, the deeper zone (19.15 m depth) of the primary aquifer was displaced completely by recharged surface water within 193, 45, and 55 days in 1992, 1993, and 1994, respectively. At the end of the third recharge season, recharged surface water represented ～50 percent of the water in the deeper zone of the primary aquifer ～1000 m downgradient from the recharge basin. A classic asymmetrical distribution of recharged surface water resulted from the recharge induced horizontal and vertical hydraulic gradients. The distribution and breakthrough times of recharged surface water obtained with stable isotopes concurred with those of major anions and bromide in a tracer test conducted during the 1995 recharge season. This stable isotope procedure effectively quantified mixing between surface and ground water.     

苏南现代化进程中的遥感土地利用动态监测——以苏、锡、常地区为例

地少人多的广大苏南地区早在６０年代已形成了强大的经济实力,改革开放以来,乡镇企业的迅速崛起带动了地区经济的全面发展。随着苏南经济的迅速发展,土地开发和利用方式也发生了较大变化。人地矛盾、人与空间的不协调日益严重。改善投资环境、合理利用城市土地、促进苏南经济的持续、快速发展,必须更好地实现土地利用的动态监测。为了适应这种新的需求,本文以苏、锡、常地区土地动态变化研究为背景,采用人机交互式解译遥感图像,将多时相遥感信息进行复合,用地理信息系统软件进行分析处理并输出图件。并对苏、锡、常地区的土地利用动态变化特点、各类型变化情况进行了具体分析。实践证明,该方法是行之有效的     

INFLUENCING WATER LEGISLATWE DEVELOPMENT WHAT TO DO AND WHAT TO AVOID1

ABSTRACT: Whomever would affect water policy development must influence the water legislative process. This paper discusses in the context of the Model State Water Allocation Code the following ten ideas about doing that: (1) seek the right timing for enactment; (2) set modest goals; (3) prepare a well-drafted proposal; (4) recognize diversity by offering legislative choices; (5) consider the impacts of adoption; (6) make alliances; (7) respect executive influence; (8) become involved in legislative interaction; (9) be flexible; and (10) persist. Heeding these ideas, although not guaranteeing enactment, is sure to be educational for participants and useful to legislators.     

ADVANCES IN THE BOUNDARY INTEGRAL EQUATION METHOD IN SUBSURFACE FLOW1

ABSTRACT: This paper explores some of the advances of the boundary element method, as applied to ground-water problems, during the last five years. Although the method is still somewhat limited compared to solution by finite elements, the range of solutions has increased considerably. Diffusion and advection-diffusion solutions are done efficiently. These include the incorporation of inhomogeneity, anisotropy, and nonlinear diffusion. The difficult problem of stream-aquifer interaction is an important application as it is much easier to follow a free surface with its multiple configurations. The application must be able to cycle between ground-water connection and disconnection with the stream and include seepage surfaces. Flow in fractured media is a natural application where the flow in fractures can usually be treated without a computational exception in spite of extremely high aspect ratios. The case of seawater intrusion forms a type of free surface problem and thus is a case for which the method has special advantages. For these and other applications the boundary element method provides an inexpensive technique for calculation where the data preparation and setup time is minimal. In most of these cases, programs can and have been written on microcomputers.     

Hedgerows and hedgerow networks in landscape ecology

Hedgerows originated and coexist with agriculture. Their internal structure and species diversity vary widely with origin (planted, spontaneous, or remnant), farming practices in adjacent fields, and the refined art of hedgerow management. Most hedgerow species are forest-edge species, and apparently none is limited to hedgerows. Wide hedgerows composed of trees and shrubs appear to function as corridors for movement of many plants and animals across a landscape. The reduction of crop loss, by dampening pest population fluctuations with hedgerow predators, remains a hypothesis for study.Field microclimate downwind of a hedgerow is modified about 16 times the hedgerow height (h) for evaporation, and approximately 28 h for wind speed. A turbulent wind pattern with harsher microclimate is present at 6–8 h if a second hedgerow is nearby downwind. Zones of higher crop productivity at 3- to 6-h downwind, and 2- to 6-h upwind of a second hedgerow may be expected. Overall, we expect little short-term difference in farm-field production with or without hedgerows.Evidence suggests that hedgerow networks, and especially their mesh size (of fields), exert a major control on many major landscape fluxes. Such fluxes include animal populations, wind speed, evapotranspiration and soil desiccation, soil erosion and nutrient runoff, species movement along network lines, and movement of field species across the network. In a relatively short period, the hedgerow ecosystem, with no unique species, has attained a metastable equilibrium, which is regulated by enormous human inputs.More than 20 economic roles of hedgerows are pinpointed. The roles, providing resources and protection of resources, are poorly known quantitatively. We conclude that hedgerows perform diverse functions for society and the farmer that are both economically and ecologically significant.