多级填料床对尿液养分吸附协同水质净化效果及机理

厕所粪污的资源化利用是我国农村“厕所革命”推进的重要任务,其中尿液的产生量大,氮、磷等养分含量分别占厕所粪污的87%和50%,相对混合粪污更加卫生和易于处理,将其单独处理和利用有利于提高厕所粪污的资源化利用水平。本文采用吸附法开展尿液氮磷回收和水质净化效果研究,通过分析生物炭、活性炭、沸石、瓷砂陶粒、凹凸棒土和混凝土6种不同填料的吸附特性和吸附机理,筛选最佳填料,采用多级填料床工艺,设计7种不同填料组合,分析其对尿液氮磷吸附及水质净化效果。结果表明,填料对氮和磷的吸附均是物理吸附与化学吸附共同作用的结果,其中氮的吸附以官能团作用和离子交换为主,磷的吸附以官能团键合和络合沉淀为主。6种填料中生物炭、活性炭对氮的吸附效果较好,沸石对磷的吸附效果较好。填料依照生物炭、活性炭、沸石顺序排列时,氮磷吸附和水质净化综合效果较好,在此条件下,尿液中氮、磷回收率分别达到76%和90.09%,出水COD和浊度去除率分别为84.36%和78.92%,色度<30,臭味降至2级水平。     

Formation of glaciers on Mars by atmospheric precipitation at high obliquity

Surface conditions on Mars are currently cold and dry, with water ice unstable on the surface except near the poles. However, geologically recent glacierlike landforms have been identified in the tropics and the midlatitudes of Mars. The ice has been proposed to originate from either a subsurface reservoir or the atmosphere. We present high-resolution climate simulations performed with a model designed to simulate the present-day Mars water cycle but assuming a 45 degrees obliquity as experienced by Mars a few million years ago. The model predicts ice accumulation in regions where glacier landforms are observed, on the western flanks of the great volcanoes and in the eastern Hellas region. This agreement points to an atmospheric origin for the ice and reveals how precipitation could have formed glaciers on Mars.     

Quantifying global warming from the retreat of glaciers

Records of glacier fluctuations compiled by the World Glacier Monitoring Service can be used to derive an independent estimate of global warming during the last 100 years. Records of different glaciers are made comparable by a two-step scaling procedure: one allowing for differences in glacier geometry, the other for differences in climate sensitivity. The retreat of glaciers during the last 100 years appears to be coherent over the globe. On the basis of modeling of the climate sensitivity of glaciers, the observed glacier retreat can be explained by a linear warming trend of 0.66 kelvin per century.     

The state and fate of Himalayan glaciers

Himalayan glaciers are a focus of public and scientific debate. Prevailing uncertainties are of major concern because some projections of their future have serious implications for water resources. Most Himalayan glaciers are losing mass at rates similar to glaciers elsewhere, except for emerging indications of stability or mass gain in the Karakoram. A poor understanding of the processes affecting them, combined with the diversity of climatic conditions and the extremes of topographical relief within the region, makes projections speculative. Nevertheless, it is unlikely that dramatic changes in total runoff will occur soon, although continuing shrinkage outside the Karakoram will increase the seasonality of runoff, affect irrigation and hydropower, and alter hazards.     

Contribution of small glaciers to global sea level

Observed long-term changes in glacier volume and hydrometeorological mass balance models yield data on the transfer of water from glaciers, excluding those in Greenland and Antarctica, to the oceans. The average observed volume change for the period 1900 to 1961 is scaled to a global average by use of the seasonal amplitude of the mass balance. These data are used to calibrate the models to estimate the changing contribution of glaciers to sea level for the period 1884 to 1975. Although the error band is large, these glaciers appear to account for a third to half of observed rise in sea level, approximately that fraction not explained by thermal expansion of the ocean.     

Sensitivity of glaciers and small ice caps to greenhouse warming

Recent field programs on glaciers have supplied information that makes simulation of glacier mass balance with meteorological models meaningful. An estimate of world-wide glacier sensitivity based on a modeling study of 12 selected glaciers situated in widely differing climatic regimes shows that for a uniform 1 K warming the area-weighted glacier mass balance will decrease by 0.40 meter per year. This corresponds to a sea-level rise of 0.58 millimeter per year, a value significantly less than earlier estimates.     

营养基质和栽培槽对番茄生长的影响研究

利用菇渣(MR)、沼渣(DR)、草炭土(PS)配合铁矿尾矿砂(IMT)等废弃物作为无土栽培的营养基质,研究了不同基质配比、不同形式的改良栽培槽对番茄生长的影响及其经济效益。结果表明:以尾矿砂∶草炭∶沼渣=3∶1∶1配比基质综合效果好、效益最高,比常用的炉渣∶草炭=3∶2基质降低物料成本约2 380元/667 m2;栽培槽以1块砖竖放的成本最低,较常规3块砖卧放的栽培槽对番茄生长和产量无明显影响,但可降低用砖成本约1 190元/667 m2。     

Rapid wastage of Alaska glaciers and their contribution to rising sea level

We have used airborne laser altimetry to estimate volume changes of 67 glaciers in Alaska from the mid-1950s to the mid-1990s. The average rate of thickness change of these glaciers was -0.52 m/year. Extrapolation to all glaciers in Alaska yields an estimated total annual volume change of -52 +/- 15 km3/year (water equivalent), equivalent to a rise in sea level (SLE) of 0.14 +/- 0.04 mm/year. Repeat measurements of 28 glaciers from the mid-1990s to 2000-2001 suggest an increased average rate of thinning, -1.8 m/year. This leads to an extrapolated annual volume loss from Alaska glaciers equal to -96 +/- 35 km3/year, or 0.27 +/- 0.10 mm/year SLE, during the past decade. These recent losses are nearly double the estimated annual loss from the entire Greenland Ice Sheet during the same time period and are much higher than previously published loss estimates for Alaska glaciers. They form the largest glaciological contribution to rising sea level yet measured.     

不同生态浮床对景观水质的净化效果

【目的】明确不同生态浮床改善亚热带地区景观水质的效果,为我国南方地区应用生态浮床技术修复生态水环境提供参考依据。【方法】对比分析不同生态浮床对景观水体化学需氧量(COD)、总磷(TP)、总氮(TN)、氨氮(NH4+-N)去除能力及浮床植物生长状况的影响。【结果】美人蕉、鸢尾、花叶芦竹均能适应较高有机物及氮、磷浓度的水体,具有良好的适应性,对水体COD、TP、TN及NH4+-N也表现出良好的去除能力,但以美人蕉的净化效果最佳。美人蕉+组合填料生态浮床、美人蕉生态浮床、组合填料浮床对水体COD、TP、TN及NH4+-N的去除能力分别为33.75~48.98、0.23~0.93、3.71~10.26和4.12~8.44 mg/m2,3种不同生态浮床对水体COD、TP、TN和NH4+-N的去除能力存在极显著差异(P<0.01),去除能力排序为美人蕉+组合填料生态浮床>美人蕉生态浮床>组合填料浮床。【结论】美人蕉+组合填料生态浮床对水体COD、TP、TN及NH4+-N的去除效果最佳,较单一使用美人蕉生态浮床和组合填料浮床的净化效果更具优势,可作为我国南方地区修复生态水环境的首选生态浮床。     

一种自适应的无线传感器网络流量控制机制

随着科技的发展和社会的进步,无线传感器网络在人们生活中的应用越来越广泛。然而,随着传感器网络负荷的增加,拥塞将会导致网络性能的大幅下降。采用基于自适应的无线传感器网络流量控制机制,通过对拥塞节点的虚拟代价进行计算和判断,并实时地将虚拟代价发送到发送节点,然后对发送节点进行流量控制,将能在很大程度上改善网络性能,提高网络服务质量。     

Accretion of mudstone beds from migrating floccule ripples

Mudstones make up the majority of the geological record. However, it is difficult to reconstruct the complex processes of mud deposition in the laboratory, such as the clumping of particles into floccules. Using flume experiments, we have investigated the bedload transport and deposition of clay floccules and find that this occurs at flow velocities that transport and deposit sand. Deposition-prone floccules form over a wide range of experimental conditions, which suggests an underlying universal process. Floccule ripples develop into low-angle foresets and mud beds that appear laminated after postdepositional compaction, but the layers retain signs of floccule ripple bedding that would be detectable in the rock record. Because mudstones were long thought to record low-energy conditions of offshore and deeper water environments, our results call for reevaluation of published interpretations of ancient mudstone successions and derived paleoceanographic conditions.     

牛顿流体紊流-层流的分层流动规律

通过分析掺入少量高粘流体形成分层紊流-层流的流动状态,抛弃传统的水力学研究方法,应用流体力学原理、高级程序设计语言和先进的数值计算技术研究了掺入少量高粘流体分层紊流-层流减阻规律,为实现管道混相输送时高效减阻和经济节约的设计提供理论依据.     

火龙果保健软糖的研制工艺研究

以火龙果、凝胶剂、葡萄糖浆等为主要原料,通过正交试验方法确定凝胶剂的最佳配比和软糖的最佳配方。结果表明:凝胶剂的最佳配比为明胶:琼脂∶卡拉胶=3∶2∶2.4,软糖的最佳工艺配方为火龙果汁25%、凝胶剂3%、柠檬酸0.09%、白砂糖20%、葡萄糖55%。在最佳凝胶剂配比和最佳工艺配方条件下,得到的产品糖体饱满、表面光滑细腻、韧而不黏,具有火龙果特有的风味。     

温室蚯蚓垄上种养不同蚓床对番茄生长的影响

以番茄为供试材料,采用常规栽培作为对照（CK）,设 3个处理,分别为：垄面上开50 cm（T1）、60 cm（T2）和70 cm（T3）宽的暗沟（蚓床）养殖蚯蚓,研究不同处理对番茄生长及品质的影响。结果表明：（1）垄上不同蚓床宽度套种套养技术均优于对照,可有效促进植株地上部生长。（2）从根系生长发育看,T1更有利于促进植株根系生长,T1根系总长、一级分枝数和健康根尖数均最多。其中,根系总长分别较CK、T2、T3增加了0.18%、0.91%和7.74%;一级分枝数分别较CK、T2、T3增加了12.53%、45.42%和18.0%;健康根尖数分别较CK、T2、T3增加了12.53%、45.42%和18.00%。（3）从产量情况看,T2产量最高,T2显著高于其他处理（P ＜ 0.05）,较T1、T3、CK分别增加了23.96%、19.91%和49.34%。（4）从品质提升看,T1更有利于提升番茄品质,T1维生素C和糖酸比含量均显著高于其他处理（P ＜ 0.05）,其中,维生素C含量分别较T2、T3、CK显著增加了22.87%、55.45%和46.40%,糖酸比分别较T2、T3和CK显著增加了23.33%、27.38%和11.08%;T1谷氨基酸与天冬氨酸比值更接近4,C/T值为5.88,分别较CK、T2、T3增加13.70%、5.76%和9.70%。（5）T1土壤有效氮、磷、钾、全量氮、磷、钾、全盐及有机质含量均最高。综合判定,垄上开50 cm宽的暗沟养殖蚯蚓套种番茄（T1）效果更佳。