湖泊湿地的水质净化效应——以太湖三山湿地为例

为了解湖泊湿地的水质净化效果,以太湖三山湿地为研究对象,综合利用遥感、GIS技术、现场水质监测、实验室分析和模型模拟等方法,分析三山湿地对污染物的拦截净化效果,进而探讨湖泊湿地对水体氮、磷污染物的削减渠道及其贡献率.结果表明三山湿地对太湖水体和三山岛生活污水均有明显净化效果.2014年三山湿地的总氮(TN)、总磷(TP)输入通量分别为549.45和19.4 t,通过水草打捞/收割分别去除20.99和4.52 t,湿地水体内TN、TP变化量分别为528.46和14.88 t,这部分营养盐输出途径包括沉积到底泥、降解转化、水体交换等.湿地的TN、TP拦截能力分别为2723.56和102.48 kg/(hm2·a).水生植物收割打捞与底泥疏浚是提高湿地水质净化能力的有效措施.水动力模拟结果显示,三山湿地建成后使附近水域水体流向发生变化,流速减小,对湿地内水质产生多方面的作用.     

温度、照度和接种量对钝顶螺旋藻去除酒精废水氮和磷的影响

【目的】确定钝顶螺旋藻(Spirulina platensis)最大程度去除酒精废水中氮、磷的最佳温度、照度和接种量。【方法】通过单因子实验与正交实验研究不同温度、照度和接种量对钝顶螺旋藻去除酒精废水中氮、磷的效果。【结果】单因子实验结果显示,不同温度、照度和接种量对钝顶螺旋藻去除酒精废水中的氮、磷有显著影响(P <0.05)。温度为30℃时,钝顶螺旋藻对酒精废水中总氮和总磷的去除率平均值最高,分别为38.0%和59.0%;照度为3000lx时,钝顶螺旋藻对酒精废水中总氮和总磷的去除率平均值最高,分别为40.9%和60.4%;接种量为(培养基的)50%时,钝顶螺旋藻对酒精废水中总氮的去除率平均值最高,为43.6%;接种量为30%时,钝顶螺旋藻对酒精废水中总磷的去除率平均值达到最高,为62.7%。正交实验结果显示,温度是影响钝顶螺旋藻去除酒精废水中氮、磷的最主要因素。温度30℃、照度2 500～3 000 lx、接种量20%为钝顶螺旋藻去除酒精废水氮和磷的最优组合条件。【结论】适宜的温度、照度和接种量可有效提高酒精废水中氮、磷的去除率。     

TERRA: Terrain Extraction from elevation Rasters through Repetitive Anisotropic filtering

Over the past decades, several filters have been developed to derive a Digital Terrain Model (DTM) from a Digital Surface Model (DSM), by means of filtering out aboveground objects such as vegetation. In this filtering process, however, one of the major challenges remains to precisely distinguish sharp terrain features, e.g. ridges, agricultural terraces or other anthropogenic geomorphology such as open-pit mines, riverbanks or road ramps. Hence, loss of elevation data around terrain edges (and consequent smoothing) is very common with existing algorithms. In terraced landscapes, the preservation of precise geomorphology is of key importance in digital terrain analyses, such as hydrologic and erosion modelling, or automatic feature recognition and inventorying. In this work, we propose a new filtering method called TERRA (Terrain Extraction from elevation Rasters through Repetitive Anisotropic filtering). The novelty of the algorithm lies within its usage of terrain aspect to guide the anisotropic filtering direction, therefore maximising the preservation of terrain edges. We derived six DTMs from DSMs using UAV Structure from Motion (SfM) photogrammetry, laser altimetry and satellite sources (grid resolutions ranging from 0.1–1.0 m). The results indicated a close agreement of DTMs filtered using the TERRA algorithm and reference DTMs, while terrace risers were well preserved even under thick canopies of vines and trees. Compared to existing filtering approaches, TERRA performed well in minimising Type I errors (false ground removal), while Type II errors occurred locally where vegetation was covering the terrace edges. Given the promising filtering performance, and supported by the minimal requirements of parameterisation and computation, the TERRA algorithm could be a useful tool in DTM preparation for digital terrain analysis of agricultural terraces and similar hillslopes characterised by a complex mosaic of sharp terrain and non-terrain features.     

南海北部大鹏湾中DOP的分布、滞留时间、自养生产和异养降解

The importance of dissolved organic phosphorus(DOP) as a potential nutrient source for primary producers in marine systems has been recognized for up to eight decades, but currently, the understanding of the biogeochemistry of DOP is in its infancy. In the present study, monthly data between 2000 and 2014 were used to analyze the temporal and spatial distributions of DOP in the Mir Bay, the northern South China Sea. The DOP residence time(T_(DOP)) was also investigated using a simple regression analysis in combination with chlorophyll a(Chl a) measurements while excess DOP(ΔDOP), produced by the biogeochemical processes of autotrophic production and heterotrophic removal, was determined using a two-component mixing mass-balance model in combination with salinity measurements. The results showed that the DOP concentration was(0.017±0.010) mg/L higher in the surface-water compared with the bottom-water and higher in the inner Tolo Harbour and waters adjacent to Shatoujiao compared with the main zone of the bay. Although seasonal changes and annual variability in the DOP were small, the surface DOP concentration was higher in the wet season(April–September)than in the dry season(October–March) due to the impacts of seaward discharges and atmospheric deposition into the bay. Measurement and regression results showed that the DOP release rate from phytoplankton production was about 1.83(gP)/(gChl a) and the T_(DOP) was about 7 d, which implied that the DOP cycle in the bay was rapid. The ΔDOP was calculated from the model to be about 0.000 mg/L in the main zone of the bay and about 0.002 mg/L in the inner Tolo Harbour and waters adjacent to Shaotoujiao, suggesting that the autotrophic production of DOP was almost balanced by the heterotrophic removal in the main zone of the bay and dominated in the inner Tolo Harbour and waters adjacent to Shaotoujiao. In conclusion, the Mirs Bay is very productive and fairly heterotrophic.     

若尔盖盆地-西秦岭造山带结合部位深反射资料的静校正和去噪技术

深地震反射剖面技术是探测岩石圈精细结构的有效手段.通常情况下工区地质情况复杂,尤其在盆山结合部位,地表地形起伏大,地下构造复杂,其深地震反射资料具有低信噪比、干扰强、构造复杂等特点,给后续处理和解释造成很大困难,因此获得真实的叠加剖面是地质解释的前提和基础.复杂地区低信噪比深地震反射资料处理的关键是做好静校正和去噪工作.本文以若尔盖盆地－西秦岭造山带接合部位深地震反射资料作为例,通过方法试验和参数测试,找到适合该工区的静校正方法和去噪技术,得到较好的处理结果,为揭示若尔盖盆地－西秦岭造山带结合部位的细结构提供了可靠的依据.     

微藻在污水中的除磷脱氮作用

初步调查了广州海珠区污水排放区污水中微藻的组成,表明该区微藻以蓝藻门颤藻科Ｏｓｃｉｌｌａｔｏｒｉａｃｅａｅ为主,以小颤藻Ｏｓｃｉｌｌａｔｏｒｉａｔｅｎｕｉｓ、两栖颤藻Ｏ．ａｍｐｈｉｌｉａ为优势种;测定了其在污水中的除磷脱氮能力,结果表明,两优势种处理污水氮、磷的能力随微藻的生长期和污水中氮、磷浓度的不同而有较大的变化。     

CO2倍增下遥感-光合作物产量响应模型的研究与应用

由于卫星散射计探视雷达回波的各向异性的双调和性质,同时由于散射物理模型函数的非线性及信号中存在噪声,使得常规点方式风场反演中风向有多至4 个解的多解存在。给出了一种改进的场方式反演方法,利用该方法从卫星散射计测量的后向散射强度的数据中唯一反演出大尺度海洋风场。通过数值模拟和实际算例计算表明反演结果在风向、风速上都与真解是吻合的。从结果可以看到,所采用的改进的场方式反演方法对模拟数据或真实散射计探测海面风场的反演是成功的。     

Glitch effects in ISOCAM Long Wave detector

One of the main limitations to the sensitivity of observations carried out withthe ISOCAM infrared camera comes from the responsivity variations and glitchescaused by impacts of charged particles. After more than 28 months of successfuloperations, the predicted glitch rate has been re-evaluated and compared toin-flight measurements. Glitch properties have been studied in orderto improve the removal algorithms, and thus the ultimate sensitivity of ISOCAM.All informations about the glitch phenomenon are very useful in order toprepare next space experiments.     

基于多源激光点云融合的建筑物BIM建模

墙体、窗户等单元构件是建筑物重要组成部分,精细提取其几何参数及位置信息对于完整表达建筑物整体模型具有重要意义.针对单一点云数据源无法获取建筑物单元构件相关参数并完整表达室内外模型重建问题,本文提出一整套融合室内外多源点云数据的BIM模型重建技术.为验证方法的有效性,选取河南理工大学测绘与国土信息工程学院教学楼为实验区域...     

NP油田Ed1储层泥浆伤害综合评价与解堵技术研究

酸化是解除该类储层伤害,恢复、提高油气井产能最主要的手段。对于各种特定的伤害类型若仅采用笼统的酸化措施,往往难以取得理想的增产效果,如何从伤害机理的角度出发对症解除污染是研究者面临的重要课题。NP油田Ed1储层在以往的酸化改造中,由于对钻井泥浆伤害机理认识不够准确,导致酸液选择存在较大的盲目性,严重影响解堵效果。为解决上述问题,提出酸化解堵设计方法,通过泥浆固相粒度和滤液红外波谱分析试验评价,明确了Ed1储层钻井泥浆伤害产生的机理。在此基础上,设计在同一组试验内先模拟泥浆伤害的产生,发现岩心伤害后渗透率降低至基准渗透率的0.12倍,然后比较评价不同类型的酸液解除该类泥浆污染的能力,最终筛选出解堵效果最好的4%多氢酸体系推荐现场施工使用。