中国菌糠露天焚烧污染物排放时空分布特征

基于我国2000~2017年食用菌年产量数据,采用排放因子法估算了菌糠露天焚烧的污染物排放量,利用Mann-Kendall法和聚类分析法分析了排放量的时空分布特征,使用回归分析法预测了污染物的排放趋势.结果表明：（1）2000~2017年全国菌糠露天焚烧污染物排放量持续上升,PM_2.5、CO₂、CO、CH₄、NMVOCs、PAHs、NO_x、SO₂累积排放量分别为1.40×10⁶,3.48×10⁸,1.99×10⁷,8.43×10⁵,2.08×10⁶,3.00×10⁴,6.34×10⁵,8.29×10⁴t;（2）污染物排放量较高的省区包括山东、黑龙江、浙江、湖南、江苏、福建和河南,排放量较低的省区包括贵州、宁夏、天津、北京、新疆、重庆、甘肃;（3）预计2021年菌糠焚烧污染物总排放量高达4.25×10⁷t,其对生物质焚烧污染物总排放量的贡献率约为19.82%.我国菌糠露天焚烧污染物排放规模较大,应予以重点关注.     

Heavy metals in water bodies purified by suspended substrate of rivers

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骆马湖的氮磷平衡及实施截污工程对水质改善效果的研究

骆马湖“九五”期间的氮磷平衡分析结果表明：氮磷在骆马湖湖体中的滞留量分别为1188.89t/a和193.36t/a。根据骆马湖的水质要求，在骆马湖截污工程完成后，没有新的污染进入水体的前提下，对骆马湖水体通过自然净化恢复到要求状态所需的时间进行了详细的数学推导和科学论证，结果表明，在不考虑底泥营养物质的情况下，只需0.19年左右的时间就能恢复，如果考虑底泥的影响。也只需0.59年左右的时间就能恢复，因此得出结论：对骆马湖实施截污是加速骆马湖水体改善的最佳途径。     

COLD WATER PATCHES IN WARM STREAMS: PHYSICOCHEMICAL CHARACTERISTICS AND THE INFLUENCE OF SHADING1

ABSTRACT: Discrete cold water patches within the surface waters of summer warm streams afford potential thermal refuge for cold water fishes during periods of heat stress. This analysis focused on reach scale heterogeneity in water temperatures as influenced by local influx of cooler subsurface waters. Using field thermal probes and recording thermistors, we identified and characterized cold water patches (at least 3°C colder than ambient streamflow temperatures) potentially serving as thermal refugia for cold water fishes. Among 37 study sites within alluvial valleys of the Grande Ronde basin in northeastern Oregon, we identified cold water patches associated with side channels, alcoves, lateral seeps, and floodplain spring brooks. These types differed with regard to within floodplain position, area, spatial thermal range, substrate, and availability of cover for fish. Experimental shading cooled daily maximum temperatures of surface waters within cold water patches 2 to 4°C, indicating a strong influence of riparian vegetation on the expression of cold water patch thermal characteristics. Strong vertical temperature gradients associated with heating of surface layers of cold water patches exposed to solar radiation, superimposed upon vertical gradients in dissolved oxygen, can partially restrict suitable refuge volumes for stream salmonids within cold water patches.     

Development of Layered Sediment Structure and its Effects on Pore Water Transport and Hyporheic Exchange

Hyporheic exchange is known to provide an important control on nutrient and contaminant fluxes across the stream-subsurface interface. Similar processes also mediate interfacial transport in other permeable sediments. Recent research has focused on understanding the mechanics of these exchange processes and improving estimation of exchange rates in natural systems. While the structure of sediment beds obviously influences pore water flow rates and patterns, little is known about the interplay of typical sedimentary structures, hyporheic exchange, and other transport processes in fluvial/alluvial sediments. Here we discuss several processes that contribute to local-scale sediment heterogeneity and present results that illustrate the interaction of overlying flow conditions, the development of sediment structure, pore water transport, and stream-subsurface exchange. Layered structures are shown to develop at several scales within sediment beds. Surface sampling is used to analyze the development of an armor layer in a sand-and-gravel bed, while innovative synchrotron-based X-ray microtomography is used to observe patterns of grain sorting within sand bedforms. We show that layered bed structures involving coarsening of the bed surface increase interfacial solute flux but produce an effective anisotropy that favors horizontal pore water transport while limiting vertical penetration.     

以造粒粉煤灰为过滤介质去除景观水中磷的研究

研究了造粒粉煤灰的最大磷吸附量、磷吸附速率等吸附特征，以及颗粒粒径、磷浓度、水力负荷对景观水除磷效果的影响。还进行了为期21天的连续过滤试验，发现滤床在高水力负荷条件下能持续地去除景观水中的磷。     

Polymeric Complexes from Casein and Starch Phosphate: Characteristics and Enzyme Susceptibility

Novel biodegradable materials were prepared from potato starch enriched in phosphato moieties (DS 0.018 and 0.033) and casein in defatted milk. The components were blended in proportions providing starch: casein ratios of 2:1, 1:1, and 1:2 and were then precipitated with hydrochloric acid. Aqueous solubility, water-binding capacity, infrared spectra, and thermal analysis (thermogravimetry[7] and differential thermogravimetry of the precipitates revealed that they were not simple physical mixtures of the components. The components interacted with one another electrostatically with involvement of the phosphate groups of starch and the peptide bond of casein, as documented by infrared spectra. Because of insolubility in 7 M aqueous urea solution, they might also be considered as complexes in which the components were chemically bound.     

BASE FLOW RECESSION RATES,LOW FLOWS,AND HYDROLOGIC FEATURES OF SMALL WATERSHEDS IN PENNSYLVANIA,USA1

This paper examines the relationships between measurable watershed hydrologic features, base flow recession rates, and the Q_7,10 low flow statistic (the annual minimum seven‐day average streamflow occurring once every 10 years on average). Base flow recession constants were determined by analyzing hydrograph recession data from 24 small (>130 km²), unregulated watersheds across five major physiographic provinces of Pennsylvania, providing a highly variable dataset. Geomorphic, hydrogeologic, and land use parameters were determined for each watershed. The base flow recession constant was found to be most strongly correlated to drainage density, geologic index, and ruggedness number (watershed slope); however, these three parameters are intercorrelated. Multiple regression models were developed for predicting the recession rate, and it was found that only two parameters, drainage density and hydrologic soil group, were required to obtain good estimates of the recession constant. Equations were also developed to relate the recession rates to Q_7,10 per unit area, and to the Q_7,10/Q₅₀ ratio. Using these equations, estimates of base flow recession rates, Q_7,10, and streamflow reduction under drought conditions can be made for small, ungaged basins across a wide range of physiography.     

A Lost Link between a Flightless Parrot and a Parasitic Plant and the Potential Role of Coprolites in Conservation Paleobiology

Late Quaternary extinctions and population fragmentations have severely disrupted animal‐plant interactions globally. Detection of disrupted interactions often relies on anachronistic plant characteristics, such as spines in the absence of large herbivores or large fruit without dispersers. However, obvious anachronisms are relatively uncommon, and it can be difficult to prove a direct link between the anachronism and a particular faunal taxon. Analysis of coprolites (fossil feces) provides a novel way of exposing lost interactions between animals (depositors) and consumed organisms. We analyzed ancient DNA to show that a coprolite from the South Island of New Zealand was deposited by the rare and threatened kakapo (Strigops habroptilus), a large, nocturnal, flightless parrot. When we analyzed the pollen and spore content of the coprolite, we found pollen from the cryptic root‐parasite Dactylanthus taylorii. The relatively high abundance (8.9% of total pollen and spores) of this zoophilous pollen type in the coprolite supports the hypothesis of a former direct feeding interaction between kakapo and D. taylorii. The ranges of both species have contracted substantially since human settlement, and their present distributions no longer overlap. Currently, the lesser short‐tailed bat (Mystacina tuberculata) is the only known native pollinator of D. taylorii, but our finding raises the possibility that birds, and other small fauna, could have once fed on and pollinated the plant. If confirmed, through experimental work and observations, this finding may inform conservation of the plant. For example, it may be possible to translocate D. taylorii to predator‐free offshore islands that lack bats but have thriving populations of endemic nectar‐feeding birds. The study of coprolites of rare or extinct taxonomic groups provides a unique way forward to expand existing knowledge of lost plant and animal interactions and to identify pollination and dispersal syndromes. This approach of linking paleobiology with neoecology offers significant untapped potential to help inform conservation and restoration plans. Un Eslabón Perdido entre un Loro No Volador y una Planta Parásita y el Papel Potencial de Coprolitos en Paleobiología de la Conservación     

石油降解菌的分离鉴定及4株芽胞杆菌种间效应

通过富集培养和分离纯化的方法,从天津大港油田石油污染土壤和渤海海上钻井平台洗油污水中分离出6株石油降解细菌,生理生化试验及16S r DNA序列分析鉴定表明,它们分别属于Bacillus芽胞杆菌属(S1、S2、S3、S4)、Pseudomonas假单胞菌属(W1)和Ochrobactrum苍白杆菌属(W2),其中,S3具有最高的烷烃(41.3%)和芳烃(30.9%)降解率,从石油污染场地中筛选出的内源微生物对本油田石油的降解效果优于外源物种.对4株芽胞杆菌属菌株构建微生物组进行石油降解实验,结果表明,由S1和S4构成的微生物组F3具有最高的烷烃(50.5%)和芳烃(54.0%)降解率,比单菌降解率分别提高了69.9%和156.1%,同时比最优降解单菌S3的降解率分别高出22.1%和74.6%,而由S2和S3构成的微生物组F4对烷烃和芳烃的降解率最低,分别为18.5%和18.9%,比单菌降解率降低了55.3%和39.0%,实验表明同菌属微生物种间对石油的降解同时存在协同促进和拮抗抑制作用,芽胞杆菌属内亲缘性近的菌株之间对石油降解主要表现为促进作用.