青藏高原边缘积雪辐射特征

利用中国陆地生态系统通量观测研究网络的玛曲站观测的一次降雪过程的资料,对青藏高原东部边缘冬季的降雪、积雪过程的辐射特征进行了分析.研究结果表明;积雪期晴天和降雪过程的向上短波辐射的峰值分别约为降雪前晴天的3和2倍.无积雪晴天地表反射率主要分布在0.175～0.36,新雪地表反射率主要分布在0.8～0.9.大气逆辐射变化较小,降雪过程的最大,积雪时的最小.地表长波辐射则为降雪前最大,降雪时最小.积雪覆盖的晴天比无积雪时的净辐射变化幅度减小,且早上由负转正的时间推迟.     

Pyrite oxidation: a state-of-the-art assessment of the reaction mechanism

The oxidation of pyrite to release ferrous iron and sulfate ions to solution involves the transfer of seven electrons from each sulfur atom in the mineral to an aqueous oxidant. Because only one or, at most, two electrons can be transferred at a time, the overall oxidation process is quite complex. Furthermore, pyrite is a semiconductor, so the electrons are transferred from sulfur atoms at an anodic site, where oxygen atoms from water molecules attach to the sulfur atoms to form sulfoxy species, through the crystal to cathodic Fe(II) sites, where they are acquired by the oxidant species. The reaction at the cathodic sites is the rate-determining step for the overall process. This paper maps out the most important steps in this overall process.     

吉林省土壤冻融的逐日变化及与气温、 地温的关系

土壤冻融过程对气候和生态环境演变有重要影响。为了研究季节冻土区土壤冻融过程及其对气候变化的响应,利用2014-2017年吉林省典型代表观测站逐日冻土、气温和地温数据,研究土壤冻融的逐日变化及其与气温、地温的关系。结果表明：在土壤冻结和融化完整过程中,冻土上限呈直线上升趋势变化,下限呈先增大后减小的三次曲线趋势变化,即从稳定冻结初日起,冻土深度逐渐加深,在达到最大值后,缓慢变浅。冻土融化包括下限和上限融化两个过程,具有“两头化”的变化特征。冻土上限融化与下限同时开始或者晚于下限,但冻土上限融化的日变化量要大于下限。在土壤冻结过程中,活动积温、0 cm地积温、10 cm地积温与冻结深度呈三次曲线变化关系,随负积温的增加,冻结深度加深。在冻土上限融化过程中,活动积温、0 cm地积温、10 cm地积温与冻土上限深度呈三次曲线变化关系,随正积温的增加,上限融化深度加深。在冻土下限融化过程中,活动积温、0 cm地积温、160 cm地积温与冻土下限深度呈显著的直线趋势,随正积温的增加,下限融化深度变浅。     

Early-indicator signals of groundwater contamination: the case of seawater encroachment

 An early indication of groundwater contamination occurs when pollutant concentrations start to fluctuate and exceed background values of ambient fresh groundwater. An analysis of a characteristic situation of this type uses data from Israel's coastal phreatic granular aquifer. The pollutant is generally seawater, and the contamination process involves replacement of freshwater by encroaching sea- or other saltwater, a process augmented by human activity. The contamination process involves three stages: (1) groundwater composition remains relatively stable with small salinity content; (2) small salinity changes are perceptible with reversible fluctuations; and (3) salinity concentration increases at a sharply higher rate. The second stage is a useful early-indicator signal of contamination. Early-indicator signals of groundwater pollutant concentrations involve "minor" fluctuations in water chemistry at the advent of the contamination process. The intensity and magnitude of such a salinization/pollution process at any given location depends upon lithologic matrix, aquifer heterogeneity, and resultant flow domain characteristics, as well as contaminant properties. If such "signs" are detected at a sufficiently early stage, appropriate management steps may be taken to rectify further seawater and/or saltwater encroachment. Received: 23 July 1996 · Accepted: 25 June 1997     

大别超高压变质岩折返过程中的部分熔融作用

研究表明,在大别超高压变质岩的折返过程中,超高压变质岩一方面要经受中下地壳所特有的角闪岩相退变质作用,另一方面要在合适环境下发生部分熔融作用,超高压变质岩在中下地壳的减爱变和部分熔融作用,是一个重要的物理化学过程,它可以降低岩石的强度,提高岩石的可变性,促进挤压（碰撞）体制向伸展体制的转变。超高压变质岩折返过程减压退变和部分熔融作用的确定,进一步支持了“原地”观点。它不仅说明了超高压榴辉岩石和围岩     

应用合金天然破裂特征进行孕震机理研究

自然界的宏观和微观领域都有天然破裂现象存在,这些现象之间存在着大量的普适性筮有的特征。应用微观领域合金的天然破裂过程和宏观领域强震孕育发育过程之间的相似性,从破裂发生的环境、破裂过程的非线性特征以及临界表现等方面对孕震机理进行研究,从而为强震孕育机理研究提供了新的实验方法和证据。     

黄河干流头道拐河段凌汛期小流量过程变化及其影响因素研究

黄河干流内蒙古段河道冬季流凌封河期, 河道水量除一部分转化为冰量外, 很大一部分转化为槽蓄水量而贮存在河道中, 导致下游头道拐河段出现小流量过程, 上游河道流量转化为槽蓄水量和贮存的冰量越大, 小流量持续时间越长, 开河期发生凌汛洪水风险越高。通过对1998 - 2016年头道拐站凌讯期流量变化过程分析, 重新界定了小流量上限阈值为330 m³·s^-1, 并且以此值为标准进行小流量过程研究, 分别采用R/S极差分析法、 Fourier变换分析法对近年来小流量过程变化特征进行分析; 结合非线性概率Logit模型和Probit模型对小流量过程的影响因素进行讨论。结果表明： 小流量持续天数变化呈现缩短趋势; 同时, 小流量过程与上游相对来水之间变化关系显著且过程同步, 而滞后于河道槽蓄水量变化过程; 通过Logit模型和Probit模型分析各影响因素变化时相应小流量持续时间变化的响应概率大小, 明确河道冰流量是小流量过程第一影响因素, 气温条件是小流量过程的决定因素, 首封位置和相对来水量是小流量过程重要影响因素。     

Degradation of trace aqueous 4-chloro-2-nitrophenol occurring in pharmaceutical industrial wastewater by ozone

Degradation of 4-chloro-2-nitro phenol by ozonation in aqueous solution was studied in a semi batch reactor under constant ozone dosage and variable pH conditions. The effectiveness of the process was estimated based on the degree of conversion of 4-chloro-2-nitro phenol. It was observed that ozonation is more effective at alkaline reaction of medium than other conditions. The degree of conversion achieved (at the first 5 minutes of the process)at pH 9 was 99.64% compared to 99.03% and 77.35% at pH 7 and 3, respectively. Another parameter used to quantify the 4-chloro-2-nitrophenol during ozonation was the pseudo first order rate constant k [min^?1]. Results showed that the rate constant of the process was approximately much higher at the alkaline pH compared to acidic ones. A considerable improvement in chemical oxygen demand removal was observed at pH above 7. At pH 9, the reduction in chemical oxygen demand at the end of the process reached 56.9 %. The degree of organically bounded nitrogen conversion to nitrate was higher at pH 3. Of the total organic carbon reduction, 15.89 % was observed at pH 9. The 4-chloro-2-nitro phenol degradation intermediate products were analyzed by mass- spectrometry. The main intermediate product was chlorophenol.     

基于iTOUGH2的生物降解模型全局敏感性时变分析

Monod动力学方程被广泛应用于描述地下水中有机污染物微生物降解过程。由于Monod方程参数众多,采用敏感性分析可识别参数的重要程度,有助于参数反演和理解微生物降解过程。已有敏感性分析一般仅关注敏感性的整体平均值及其随空间的变化,很少考虑敏感性随时间的变化。以一个好氧生物降解甲苯的一维砂柱试验为例,基于iTOUGH2采用Morris法和Sobol’法对降解过程参数及试验条件参数开展全局敏感性时变分析。研究结果发现,由于微生物好氧降解能力随时间先提高后减弱,导致降解过程参数的敏感性相应地随时间先增加后减少。最大基质降解速率k的Sobol’一阶敏感性指数在试验早期小于10%,中期最大为62%,晚期减至49%。参数间的相互作用效应随时间先增大后减小。k的参数间相互作用效应根据Sobol’总敏感性指数与一阶敏感性指数的差值表征,该值在试验早期和晚期近乎为0,中期达6%。通过敏感性以及参数间相互作用效应的时变分析发现,试验晚期的观测数据对模型过程参数的敏感性较大以及相互作用效应较小,因此选择试验晚期数据更有利于降解过程参数的反演识别。同时由于试验条件参数在早期敏感性较大,为避免试验条件控制不当导致的观测数据误差增大,试验早期应较中期和晚期更严格控制试验条件。     

乌鲁木齐河源1号冰川积累区表面雪层演化成冰过程的观测研究

根据天山乌鲁木齐河源1号冰川积累区海拔4 130 m处28个月,每周1次的连续雪层剖面观测,分析研究了雪层厚度、雪层中的污化层、冰片和各种粒雪随时间的演变过程.结果表明:雪层中各种要素的演变受水热条件的影响而呈现明显的季节特征.根据温度、融水渗浸程度及雪层剖面的变化程度,我们将其分成冬季稳定期、夏季剧变期和春秋季波动期分别进行了分析.此外,还对雪层年限与年成冰量等进行了专门讨论.     

Towards an expanded model of curriculum development and diffusion in education

The general model of the curriculum development process has been widely accepted as a satisfactory view of the process at work and of how the process might be made to work in practice. Such a model ignores the human element. The paper expands the general model so as to include the social interaction and interpersonal dynamics dimension of curriculum change. Concepts in diffusion theory and behavioural geography provide a perspective for building into the curriculum process views of it as a social system akin in some respects to a feudal society. The expanded model includes consideration of the influence of the social, personal, psychological and attitudinal traits of those engaged in curriculum development. The spatial pattern likely to be created by the model provokes questions about the best management of the diffusion process.     

Gaussian approximations to conditional distributions for multi-Gaussian processes

Suppose a multi-Gaussian process is observed at some set of sites, and we wish to obtain the conditional block grade distribution given some observations. We show that this conditional distribution is approximately Gaussian under certain conditions. In particular, given a single observation from a continuous multi-Gaussian process, the conditional distribution under a small change of support is approximately Gaussian unless, roughly speaking, the observed process is twice differentiable and the observation site is at the center of mass of the support region. A Gaussian approximation for the conditional prediction error of the total ore in a fixed region is considered also, although an example demonstrates that a naive analysis can give incorrect limiting conditional means.     

The influence of the construction process on the deformation behaviour of diaphragm walls in soft clayey ground

Conventional numerical predictions of deep excavations normally neglect the construction process of the retaining structure and choose the earth pressure at rest as initial condition at the beginning of the simulation. The presented results of simulation and measurements during the construction process of the Taipei National Enterprise Center show, that such an assumption leads to an underestimation of the horizontal wall deflection, the surface ground settlements as well as the loading of the struts in case of normally to slightly over‐consolidated clayey soil deposits. The stepwise installation process of the individual diaphragm wall panels results in a substantial modification of the lateral effective stresses in the adjacent ground. Especially the pouring process of the panel and the fresh concrete pressure causes a partial mobilization of the passive earth pressure and a distinct stress level increase in the upper half of the wall. As a consequence of the increased stresses prior to the pit excavation, up to 15% greater ground and wall movements are predicted. Moreover, the increased stress level due to the installation process of the diaphragm wall leads to substantial higher strut loadings during the excavation of the pit. Copyright © 2006 John Wiley & Sons, Ltd.     

Environmental scanning electron microscopy (ESEM) and nanoindentation investigation of the crack tip process zone in marble

This study explores the interaction between crack initiation and nanomechanical properties in the crack-tip fracture process zone of Carrara marble. Specimens with preexisting cracks were loaded in a uniaxial testing machine until the process zone appeared at the tips of the preexisting cracks. ESEM analysis reveals an increase in microcrack density in the process zone with increased loading of the specimen. Nanoindentation testing comprised of lines and grids of single nanoindentations located both near and far from the process zone shows a decrease in both indentation modulus and indentation hardness near grain boundaries in intact material, and with closeness to the process zone. Ultimately, the study confirms that the crack-tip process zone manifests itself as an area of reduced indentation hardness and indentation modulus in marble.     

A reassessment of the human dimension of desertification

So far, the human dimension of desertification has been confined to some peripheral aspects of desertification. Man is either set at the beginning of the process as a triggerer or at the end as a victim. This paper tries to show the high degree of involvement of human communities in the process of desertification itself and that they undergo degradation just like the vegetation associations and the wildlife communities. A new, more human-orientated definition of desertification is discussed here.     

A model of household preparedness for earthquakes: how individuals make meaning of earthquake information and how this influences preparedness

One way to reduce the risk from earthquakes is for individuals to undertake preparations for earthquakes at home. Common preparation measures include gathering together survival items, undertaking mitigation actions, developing a household emergency plan, gaining survival skills or participating in wider social preparedness actions. While current earthquake education programmes advocate that people undertake a variety of these activities, actual household preparedness remains at modest levels. Effective earthquake education is inhibited by an incomplete understanding of how the preparedness process works. Previous research has focused on understanding the influence individual cognitive processes have on the earthquake preparedness process but has been limited in identifying other influences posed by the wider social contextual environment. This project used a symbolic interactionism perspective to explore the earthquake preparedness process through a series of qualitative interviews with householders in three New Zealand urban locations. It investigated earthquake information that individuals are exposed to, how people make meaning of this information and how this relates to undertaking actual preparedness measures. During the study, the relative influence of cognitive, emotive and societal factors on the preparedness process was explored and the interactions between these identified. A model of the preparedness process based on the interviews was developed and is presented in this paper.     

基于本源菌的褐煤生物气生成过程与可能途径

利用富集培养得到的本源产甲烷菌群对云南昭通褐煤样品进行生物气模拟实验,分析了褐煤生物气生成过程与可能 途径。结果显示,为期130 d 的褐煤生物气生成过程至少经历了两个产气高峰,第一高峰产气率高于第二高峰。本文认为第 一高峰期间生气母质主要为褐煤中的腐殖组分,第二高峰期间类脂组和惰质组的微生物降解程度相对增强。甲烷碳氢同位 素组成显示,模拟生物气主要通过乙酸发酵途径生成。模拟过程中,甲烷浓度和二氧化碳浓度具有相互消长的变化趋势, 甲烷碳同位素组成在模拟后期有变轻趋势,氢同位素则趋于变重,表明模拟过程后期生成的部分甲烷具有二氧化碳还原成因。     

静压与劈裂注浆加固铁路路基的效果分析

本文通过对滨绥铁路某段软地基进行静压与劈裂注浆处理施工效果的分析,提出在类似地层中进行软地基处理设计应注意的问题。     

Constraints on the early cooling rates of Mt. Dabie from diffusion modeling of chemical zoning of garnet

Diffusion modeling of zoning profiles in eclogite garnets from three different tectonic units of Mt. Dabie, UHPM unit, HPM unit and northern Dabie, was used to estimate the relative time span and cooling rates of these rocks. Modeling result for the Huangzhen eclogite garnet shows that the maximal time span for the diffusion-adjustment process is about 22 Ma since the peak-temperature metamorphism, which is the maximum time span from amphibolite facies metamorphism to greenschist facies metamorphism. The Bixiling eclogites had subjected to a cooling process at a rate of - 10℃/Ma from 750℃ to 560℃ during 20 Ma. The second cooling stage of the Raobazhai eclogite following granulite-facies metamorphism is an initial fast cooling process at a rate of about 25℃/Ma and then slowed down gradually. All these belong to a coherent Dabie collision orogen with differences in subduction depth and exhumation/uplifting path.