EXCEL在高精度广东省第二次土地调查控制面积计算中的应用

行政区控制面积计算是第二次土地调查的一项重要工作。本文介绍了广东省第二次土地调查行政区控制面积计算的方法与生产过程,及各软件配合使用的情况、EXCEL的部分实用功能和运用EXCEL软件在本项目中计算、检查的一些应用案例和经验。     

基于2.5维面的气象数据可视化技术——以风场数据显示为例

根据2.5维面的设计思想及曲面可视化的方法,结合部分气象数据信息具有相同的经纬度范围和海拔高度的特点,构造了基于温度和可降水量的2.5维面,并重点提出在2.5维面上进行风场流线可视化的方法。实践证明,应用2.5维面分析气象数据在一定程度上平衡了运算量和可视化结果之间的矛盾,对地理环境气象数据的分析和比较有帮助作用。     

Degradation Pathway of the Photochemical Oxidation of Ethylenediaminetetraacetate (EDTA) in the UV/H2O2-process

The degradation pathway for the oxidation of EDTA in the UV/H₂O₂-process was investigated. In absence of iron ions, the mineralization of EDTA is dominated by the reaction of the HO-radicals generated by the photolysis of H₂O₂. The organic degradation products iminodiacetate (IMDA), glycinate, oxamate, glyoxylate, oxalate and formate, and the inorganic degradation products carbon dioxide, ammonia, nitrate, nitrite, and cyanate were found. In the presence of iron ions, photolytic decarboxylation processes inside the complex get an important role during degradation, and the organic degradation products ethylenediaminetriacetate (ED3A), ethylenediaminediacetate (EDDA), ethylenediaminemonoacetate (EDMA) were also found. By combining product studies with balances of carbon and nitrogen, the degradation pathway in the UV/H₂O₂-process could be elucidated. The degradation of EDTA was fast (k_deg = 0.012 s^–1), and no toxic degradation products were identified. Therefore, the process is well suited for the elimination of EDTA in water treatment.     

敞开酸溶和偏硼酸锂碱熔ICP-MS法测定多金属矿中的稀土元素及铌钽锆铪

用电感耦合等离子体质谱法(ICP-MS)测定地质样品中的稀土及难熔元素,混合酸敞开酸溶法和碱熔融法是两种主要的溶样方法。但地质样品组分复杂,元素之间存在相互共生的现象,对于特殊元素、特殊样品用传统酸溶法会造成部分元素消解不完全,使测定结果不准确;而碱熔法的操作过程繁琐,且溶液盐度高,易产生基体干扰和堵塞仪器进样系统。本文改进了传统四酸和五酸体系,采用氢氟酸-硝酸-硫酸敞开酸溶体系,用国家一级标准物质制作标准曲线测定15种稀土元素,方法准确度(ΔlgC)为0.001～0.027。同时改进了偏硼酸锂碱熔法,样品用偏硼酸锂碱熔提取,加入氢氧化钠调节溶液至碱性条件,所测元素与偏硼酸锂共沉淀后过滤分离熔剂,再用硝酸复溶测定15种稀土元素及铌钽锆铪。两种溶样方法的测定值与认定值的相对误差为1.09%～9.30%。将混合酸敞开酸溶法测定稀土元素、偏硼酸锂碱熔法测定铌钽锆铪的结果与其他实验室密闭酸溶法相比,两组数据的相对偏差为0.13%～15.32%。本实验表明,混合酸敞开酸溶法适用于测定地质样品中的稀土元素,偏硼酸锂碱熔法不仅适用于测定地质样品中的稀土元素及铌钽锆铪,也适用于测定如古老高压变质岩石及铝含量高的样品中的铌钽锆铪。     

南极海洋动物粪土源N2O稳定同位素实验研究

N₂O是一种重要的温室气体,土壤是全球N₂O的重要排放源。通过测定土壤源N₂O中N、O同位素值,可以有效识别N₂O的来源途径。本文采集了南极法尔兹半岛两个地点的海豹粪土（HS和GS）、阿德雷岛两个地点的企鹅粪土(AB和AF)以及东南极的帝企鹅粪土(DQ和DQT),在室内对所采集的样品分别在有氧和厌氧条件下进行冻融培养实验。结果表明：土壤在厌氧条件下比有氧条件下排放了更多的N₂O。土壤排放的N₂O与当地大气N₂O相比普遍贫15N和18O。除DQT和HS外, δ15N和δ18O在有氧和厌氧培养下均呈现很好的正相关性。N₂O排放量下降的同时伴随着培养瓶内剩余N₂O中δ15N和δ18O 值的增加,证实N₂O还原为N2的过程会引起重同位素富集。高的水分含量有利于土壤反硝化作用的进行,使释放的N₂O气体富集重同位素;pH值也会影响N₂O的同位素组成,低pH会引起δ15N值增加。     

Limestone Dissolution Processes in Beke Doline Aggtelek National Park,Hungary

Aggtelek National Park, Hungary, is a limestone karst upland characterized by karren, dolines and river caves. For a period of two years, climatic and carbonate dissolution variables were monitored at four depths in a 7·5 m shaft through the soil fill in the floor of a typical large (150 m diameter) doline. Results are compared to other monitoring stations in the shallow soils on side slopes. Runoff and groundwater flow are focused into the base of the doline soil fill, where moisture is maintained at 70–90 per cent field capacity and temperatures permit year-round production of soil CO₂. The capacity to dissolve calcite (limestone) ranges from c. 3 g m⁻² per year beneath thin soils on the driest slopes to 17–30 g m⁻² per year in the top 1–2 m of doline fill and at its base 5–7 m below. © 1997 John Wiley & Sons, Ltd.     

Solute provenance,transport and denudation in a high arctic glacierized catchment

Recent understanding of chemical weathering in glacierized catchments has been focused on mid-latitude, Alpine catchments; comparable studies from the high latitudes are currently lacking. This paper attempts to address this deficiency by examining solute provenance, transport and denudation in a glacierized catchment at 78°N in the Svalbard High Arctic archipelago. Representative samples of snow, glacier ice, winter proglacial icing and glacier meltwater were obtained from the catchment during spring and summer 1993 and analysed for major ion chemistry. Seasonal variations in the composition of glacier meltwater occur and are influenced by proglacial solute acquisition from the icing at the very start of the melt season, and subsequently by a period of discharge of concentrated snowmelt caused by snowpack elution; weathering within the ice-marginal channels that drain the glacier, particularly carbonation reactions, continues to furnish solute to meltwater when suspended sediment concentrations increase later in the melt season. Partitioning the solute flux into its various components (sea-salt, crustal, aerosol and atmospheric sources) shows that c. 25% of the total flux is sea salt derived, consistent with the maritime location of the glacier, and c. 71% is crustally derived. Estimated chemical denudation, 160 meq m⁻² a⁻¹ sea salt-corrected cation equivalent weathering rate, is somewhat low compared with other studied glacierized catchments (estimates in the range 450–1000 meq m⁻² a⁻¹), which is probably attributable to the relatively short melt season and low specific runoff in the High Arctic. A positive relationship was identified between discharge and CO₂ drawdown owing to carbonation reactions in turbid meltwater. © 1997 John Wiley & Sons, Ltd.     

A Floating Astronomical Time Scale for the Early Late Cretaceous Continental Strata in the Songliao Basin,Northeastern China

A continuous terrestrial succession was recovered from the Songke-2(SK-2) borehole in the Songliao Basin, Northeastern China. This borehole provides a unique material for further research on the continental paleoclimate during Cretaceous greenhouse period, following a series of achievements of the Songke-1(SK-1) core. In this study, thorium(Th) logging data were chosen as a paleoclimate proxy to conduct a detailed cyclostratigraphic analysis. The Th series varies quasi-periodically; power spectra and evolutionary fast Fourier transformation(FFT) analysis reveal significant cycles in the Quantou(K2 q), Qingshankou(K2 qn), Yaojia(K2 y) and Nenjiang(K2 n) formations. The ratio of cycle wavelengths in these stratigraphic units is approximately 20:5:2:1, corresponding to long orbital eccentricity(405 kyr), short orbital eccentricity(100 kyr), obliquity(37 kyr), and precession cycles(22.5 kyr and 18.4 kyr). The durations of the K2 n, K2 y, K2 qn and K2 q are estimated as 6.97, 1.83, 5.30 and 4.52 Myr, respectively, based on the constructed ～18.62 Myr "floating" astronomical time scale(ATS). Comparison of the durations between the SK-1 s and SK-2 boreholes exhibits a slight difference of 0.06 Myr and 0.459 Myr for K2 qn and K2 y. Nevertheless, our ATS of K2 n supports the chronostratigraphic frame constructed by the CA-ID-TIMS data of the SK-1 s borehole. This new "floating" ATS provides precise numerical ages for stratigraphic boundaries, biozones and geological events in the Songliao Basin, and can serve as a basis for correlation of strata and events between marine and terrestrial systems.     

CO2浓度升高对浮游藻类元素化学计量值的影响

通过梅梁湾和东太湖的四季原位实验,研究CO_2浓度升高对不同营养水平淡水生态系统中浮游藻类C、N、P元素计量值的影响.实验设置了270、380和750 ppm共3个CO_2浓度,分别代表工业革命前、当前和IPCC预测的21世纪末的CO_2浓度.结果表明梅梁湾水体营养盐浓度在四季均高于东太湖水体营养盐浓度,但梅梁湾原位实验中浮游藻类C、N、P含量却普遍低于东太湖原位实验中浮游藻类营养元素含量,并且前者在季节上变化更大.CO_2浓度升高使梅梁湾原位实验中浮游藻类C∶P比明显增加,N∶P比略有增加,这种增加归因于藻细胞内C、N含量的升高,而东太湖浮游藻类化学计量值对CO_2浓度变化的响应不显著.因此浮游藻类元素化学计量值对CO_2浓度变化的响应程度与水体营养盐的绝对浓度无关,而与浮游藻类的生长是否受营养盐限制有关,只有当藻类生长受到水体营养盐浓度限制时,CO_2浓度升高才会显著改变其元素组成.     

微囊藻CO2-浓缩机制基因型的动态变化及其对CO2的竞争效应

由于具有高效的CO₂-浓缩机制,蓝藻在低CO₂浓度条件下具有竞争优势。然而,随着大气中CO₂浓度急剧增加,蓝藻CO₂-浓缩机制如何响应的研究较少。因此,本文以常见水华蓝藻——微囊藻为研究对象,通过对滇池微囊藻水华动态及不同CO₂-浓缩机制基因型进行监测,探讨蓝藻CO₂-浓缩机制基因的微进化特征及其动态变化。同时,设置高(0.08%)、中(0.04%)、低(0.02%)CO₂浓度(V/V)进一步揭示微囊藻不同CO₂-浓缩机制基因微进化对CO₂的竞争效应。结果表明:滇池无机碳浓度在4个采样点存在空间差异性,均呈现先降低后升高的趋势,并以HCO₃^-为主要无机碳存在形式。调查期间,东大河、观音山、洛龙河和生态所4个采样点的微囊藻均以sbtA基因型占绝对优势,相对丰度远高于bicA基因型。在不同水华时期,bicA基因型和sbtA基因型呈现相反的变化趋势,即从...