衡阳紫色土丘陵坡地土壤酶活性对植被恢复的响应

以典型的衡阳紫色土丘陵坡地植被不同恢复阶段为研究对象。采用空间代替时间序列的方法,选用立地条件基本相似的裸荒地、草本群落、灌木群落和乔木群落4种类型表示恢复的4个阶段,通过调查取样和实验分析,探索不同恢复条件下0-10、10-20、20-40 cm土层酶活性的分布特征,以及土壤酶活性对植被恢复的响应。结果表明：1）随着恢复的进行,脲酶、蔗糖酶与碱性磷酸酶活性显著增加（P＜0.05）,过氧化氢酶活性显著减小（P＜0.05）。2）随着土层的加深,脲酶、蔗糖酶与碱性磷酸酶活性显著减小（P＜0.05）,过氧化氢酶活性显著增加（P＜0.05）。3）脲酶、蔗糖酶与碱性磷酸酶之间呈极显著正相关（P＜0.01）,且均与土壤含水量、物理性黏粒、土壤有机碳、全氮、全磷、碱解氮、速效钾、阳离子交换量呈极显著正相关（P＜0.01）,与容重及pH值呈显著或极显著负相关（P＜0.05或P＜0.01）。4）过氧化氢酶与脲酶呈极显著负相关（P＜0.01）,与蔗糖酶与碱性磷酸酶相关性不显著（P＞0.05）,与土壤有机碳、全氮、碱解氮、速效钾及阳离子交换量呈显著或极显著负相关（P＜0.05或P＜0.01）,与 pH 值呈显著正相关（P＜0.05）。5）土壤脲酶、蔗糖酶与碱性磷酸酶可敏感地反映植被过程中土壤质量的变化,植被恢复可改善表层与深层土壤的生物学性质。     

Dose and frequency dependent effects of olive mill wastewater treatment on the chemical and microbial properties of soil

Olive mill wastewater (OMW) is a problematic by-product of olive oil production. While its high organic load and polyphenol concentrations are associated with troublesome environmental effects, its rich mineral and organic matter contents represent valuable nutrients. This study aimed to investigate the valorization of this waste biomass as a potential soil conditioner and fertilizer in agriculture. OMW was assayed at three doses 50, 100, and 200 m³ ha⁻¹ year⁻¹) over three successive years in olive fields. The effects of the effluent on the physico-chemical and microbial properties of soil-layers were assessed. The findings revealed that the pH of the soil decreased but electrical conductivity and organic matter, total nitrogen, sodium, and potassium soil contents increased in proportion with OMW concentration and frequency of application. While no variations were observed in phosphorus content, slow increases were recorded in calcium and magnesium soil contents. Compared to their control soil counterparts, aerobic bacteria and fungi increased in proportion with OMW spreading rates. The models expressing the correlation between progress parameters and OMW doses were fitted into a second degree polynomial model. Principal component analysis showed a strong correlation between soil mineral elements and microorganisms. These parameters were not related to phosphorus and pH.     

基于保护层风险分析的液氯充装系统SIL审核评估研究

研究借助GB/T 20438—2006的系统安全完整性理念,在分析了液氯充装系统工艺流程的基础上,建立了液氯充装系统的4个独立保护层并对其进行了安全性分析,根据液氯充装的危险性,确立了液氯充装系统的安全完整性等级为SIL3。从系统安全完整性出发,对系统安全性要求分配进行了探讨,提出了以各保护层失效概率为基础的液氯充装系统安全完整性审核评估,为系统的风险分析评估提供了一种新的思路。     

下扬子区中晚元古界沉积建造特征、构造运动及其演化

下扬子区中上元古界,可以分为四个构造层次.中元古界早期构造层,为一套巨厚的地槽型火山碎屑岩及砂泥质复理石建造,形成于1900-1400Ma;中元古界晚期构造层,为滨海——浅海——半深海砂泥质复理石建造.形成于1400-1000Ma;晚元古界早期构造层,为山前凹地或山间盆地磨拉石堆积,形成于1000-800Ma;晚元古界晚期(震旦系)构造层,则为砂泥质、硅质、碳酸盐岩夹冰碛砾岩建造,形成于800-600Ma.这些构造层之间不同形式的接触关系都代表着不同性质的构造运动,九岭群和修水间的修水运动,形成扬子准地台的雏型;上溪群和历口群邓家组间的祁门运动是形成扬子准地台的主褶皱幕;历口群铺岭组和震且系间的休宁运动,只使地壳抬升.这些不同性质的构造运动,也是推动地质历史演化的主要动力.     

Mass conservation and atmospheric dynamics in the Regional Atmospheric Modeling System (RAMS)

This paper examines the spatio-temporal patterns of atmospheric carbon dioxide transport predicted by the Regional Atmospheric Modeling System (RAMS). Forty-eight hour simulations over northern New England incorporating a simple representation of the diurnal summertime surface carbon dioxide forcing arising from biological activity indicate that, in its native formulation, RAMS exhibits a significant degree of mass non-conservation. Domain-wide rates of non-physical mass gain and mass loss are as large as three percent per day which translates into approximately eleven parts per million per day for carbon dioxide — enough to rapidly dilute the signature of carbon dioxide fluxes arising from biological activity. Analysis shows that this is due to the approximation used by RAMS to compute the Exner function. Substitution of the exact, physically complete equation improves mass conservation by two orders of magnitude. In addition to greatly improving mass conservation, use of the complete Exner function equation has a substantial impact on the spatial pattern of carbon dioxide predicted by the model, yielding predictions differing from a conventional RAMS simulation by as much as forty parts per million. Such differences have important implications both for comparisons of modeled atmospheric carbon dioxide concentrations to observations and for carbon dioxide inversion studies, which use estimates of atmospheric transport of carbon dioxide in conjunction with measurements of atmospheric carbon dioxide concentrations to infer the spatio-temporal distribution of surface carbon dioxide fluxes. Furthermore, use of the complete Exner function equation affects the vertical velocity and water mixing ratio fields, causing significant changes in accumulated precipitation over the region.     

《中国自然灾害数字地图集》的编制

随着地图应用范围的日益扩大和数字地球的提出，数字地图开始得到发展，它与传统地图在信息源、容量、表达方式以及兼容扩展等方面有着较大的差别。数字地图具有的3个表达层次：视觉表达、逻辑表达和物理表达，使得处理海量地图数据、生成多用户视图成为数字地图集的最大优势。基于自然灾害专题信息的特殊性，作者开发的自然灾害数字地图集在数据精度、信息表达以及自然灾害的时空性展示等方面独具特点，它是挖掘灾害数据、传播信息的一种有效手段。     

基于SDS结构理论建构和谐环巢湖旅游带

建构和谐社会是可持续发展战略的目标。从可持续发展系统层次结构与旅游区发展的关系出发,以和谐思想为支撑,解析建构环巢湖带过程中的非和谐阻力,提出建构和谐环巢湖旅游带的战略响应原则和战略响应举措,为相关部门积极主动、科学合理地规避规划、开发、经营和管理中来自各方的非和谐阻力,以期为打造一个体现和谐、健康、可持续发展的环巢湖旅游带提供一定的借鉴作用。     

可渗透反应复合电极法对铬(Ⅵ)污染土壤的电动修复

将Fe0、沸石等活性材料附着在电极上构成可渗透反应复合电极,以Cr(Ⅵ)污染土壤为处理对象,对电动修复过程中可渗透反应复合电极法对土壤pH的控制、Cr的去除效果以及形态变化进行了研究.结果表明,添加可渗透反应材料的复合电极法比单一电极法无论在土壤pH控制还是Cr的去除方面都有明显的改善和提高,其中以在阳极同时添加Fe0和沸石效果最为显著.在施加2 V.cm-1的直流电压,运行5 d后,相比在阳极单纯添加沸石或Fe0可渗透反应层,添加"Fe0+沸石"反应层能在最大程度上减小阳极土壤pH值的波动,可将土壤pH值控制在5.5～8.5范围内,土壤中任意位置Cr(Ⅵ)的去除率可提高到97%以上,土壤中残留的Cr(Ⅲ)更少,可渗透反应层对Cr的截留量可分别提高8倍和1.8倍,并将98%的Cr(Ⅵ)转化为低毒的Cr(Ⅲ).研究结果为开发具有实用意义的可渗透反应复合电极修复技术提供了理论依据.     

Effects of an Oil Spill on Soil Physico-Chemical Properties of a Spill Site in a Typic Udipsamment of the Niger Delta Basin of Nigeria

Physico-chemical analysis of soil samples at an oil spill site in a Typic Udipsamment of the Niger Delta Basin of Nigeria showed that the total hydrocarbon content of top soil layers ranged from 18.6 to 23.6 ppm in the heavy impact zone and the oil had penetrated to a depth op 8.4 m. The concentration of hydrocarbons in the medium impact zone ranged from 10.04 to 10.38 ppm while hydrocarbons were not detected in 85% of samples from the unimpacted reference zone. Heavy metal concentration measurements in the soil revealed a significant build-up (P < 0.05) of lead, copper and zinc in the heavy impact zone. Other quality parameters including electrical conductity, exchangeable cations, total nitrogen and available phosphorus in impacted soils were relatively low, while the total organic carbon was high compared with the reference site. Textural class of soil from the different depths showed a predominantly brown sand at the topsoil, loamy sand and grey coarse sand at medium depths, and grey coarse sand and greyish sandy clay at greater depths.     

Tolerance of an Albino Fish to Ultraviolet-B Radiation

We exposed albino and pigmented medakaOryzias latipes to simulated solar ultraviolet-B (UVB) radiation to determine if albino medaka were less tolerant of UVB radiation than medaka pigmented with melanin. There was no difference in the number of albino and pigmented medaka that died during the exposure period. Spectrophotometric analyses of the outer dorsal skin layers from albino and pigmented medaka indicated that, prior to exposure, both groups of fish had similar amounts of an apparent colorless non-melanin photoprotective substance that appears to protect other fish species from UVB radiation. Our results indicate that albino medaka were as tolerant of UVB radiation as pigmented medaka because they had similar amounts of this photoprotective substance in the outer layers of the skin.