降雨条件下黄土坡面溶质随地表径流迁移实验研究

根据西北黄土坡面溶质随地表径流迁移的特点，研制了黄土坡面溶质随地表径流迁移实验系统，并利用此系统进行了室内模拟实验，根据实验资料分析了土壤中各种离子随地表径流迁移特性，详细分析了土壤溶质随地表径流迁移机理。     

降水引起的地表径流中汞来源的研究

收集了北京市西北郊玉米地块的夏季降水和地表径流水样，对样品中各种形态的汞和理化性质进行了测定。结果表明，地表径流中的汞含量大于降水中汞的含量，用典型相关分析确定了地表径流中的汞来源及其影响因素。降水产生的地表径流与土壤接触后发生反应，可溶解土壤中的汞向水体中输送，地表径流的性质影响地表径流中汞的形态。估算出地表径流每年汞输出率约为18．24μg.m^-2。     

草地坡面径流调控放水试验研究

通过坡面放水模拟径流冲刷试验，研究了不同放水流量下草地减水减沙效应，并从起流历时、径流流速、径流深度等方面分析了草地调控水沙的机理。结果表明：（1）草地具有显著的减水减沙效应，平均径流系数较对照减少28．3％，输沙率较对照减少78．4％。（2）裸地与草地坡面产流规律一致，裸地土壤坡面的输沙率呈先增后减再增的变化趋势，而草地坡面的输沙率呈先增后减然后逐渐趋于稳定。（3）草地能将坡面径流起流历时推迟3倍以上，可将径流流速减小40％，从而使草地坡面的径流入渗率明显增加，使径流的冲刷能力和输沙能力迅速下降。（4）草地对径流深度的影响不明显，径流深度的变化难以反映草地对径流的调控作用，径流流速可能会更好地反映水土保持措施的径流调控效果和能力。     

北盘江流域降雨,径流,产沙相互关系研究

根据北盘江流域５个文站降雨，径流和悬移质输沙模数资料，采用线性函数和幂函数拟合降雨和径流，降雨和悬移质输沙模数、径流和悬移质输沙模数的相互关系，根据剩余标准差最小原则确定最优关系，并探讨了一个流域内单一雨量站资料和径流，悬移质输沙模数的关系。结果表明，流域平均降雨量与径流，悬移质输沙模数、径流与悬移质输沙模数之间存在较好相关关系，根据剩余标准差大小，确定用线性函数或幂函数表达。悬移质输沙模数与最大     

降雨径流污染及其控制述评

从降雨径流污染特点，径流过程，土壤侵蚀过程和泥沙传输过程，说明水土流失是一种严重的降雨径流污染形式，分析了讨论了水土保持措施对降雨污染的难度，提出了水土保持措施设计的3条原则。     

紫色丘陵区土壤抗冲性研究

以四川资阳土壤保护站1989－1995年径流小区观察资料为依据，分析了不同生态利用条例下，径流诸因素与相对应的泥沙冲刷量的关系，确认径流深为其主导影响因素，运用土壤抗冲性指标均值Kw=1/n∑^ni=1Kwi的计算方法，研究不同农耕措施与利用对Kw的影响，探讨了同一径流小区次降雨径流强度，径流时间与土壤抗冲性指标的关系，及作物不同生育时期土壤抗冲性指标的动态变化，并对秸杆覆 与名耕对提高土壤抗冲性的作用进行研究。     

紫色丘陵坡耕地土壤流失因子的权重分析

对不同紫色岩组形成的土壤，在不同地面坡度，不同径流小区面积，以及其它降雨径流等因子等１２项因子的主成份分析表明，土壤流失量主要同产生径流的降雨次数，最大一次降雨径流因子有关，这些因子构成第一、二主成份，并显示７０％以上的特征值累计贡献率，径流小面积大小和地面坡度因子的累计贡献率约占２５％；另对降雨径流因子和坡度因子所作的分析表明，降雨径流因子的累计贡献率约达８０％，径流含沙量和坡度因子的累计贡献约     

秸秆覆盖对黄土坡面矿质氮素径流流失的影响

利用室内模拟降雨试验，研究了秸秆覆盖对坡面土壤矿质氮素径流流失和入渗的影响。结果表明：秸秆覆盖可使侵蚀量显著减少，减沙效应十分明显。由于秸秆覆盖使坡面径流流速减弱，增加了表层土壤与地表径流的作用强度，使溶解和解吸于径流中的矿质氮素含量增加，但由径流显著减少，矿质氮流失总量仍减少。与裸地相比，秸秆覆盖可显著地增加土壤水分和硝态氮的入渗深度和入渗量。     

人工降雨条件下黄土坡面养分随径流迁移试验

降雨条件下坡面农用化合物随地表径流迁移既是农业问题，又是水环境问题。利用室内人工降雨模拟试验，研究了黄土坡面不同坡度下土壤氮、磷和钾随地表径流迁移的特征。研究结果表明，在定坡长土槽坡度变化为5°～25°范围内，初始产流时间随坡度增大呈先变小后增大的趋势；产流15 min内，径流量均急剧增加，随后趋于稳定。随着坡度增加，水土流失程度加剧，径流溶质浓度增高，土壤侵蚀对径流溶质浓度的贡献增大。基于指数函数和幂函数拟合试验数据的结果，表明了幂函数模型更适合模拟黄土坡面非饱和条件下径流溶质浓度变化过程，也可描述径流磷和钾的流失过程，但其初始阶段的拟合不太令人满意。该研究为进一步完善黄土坡面径流养分迁移模拟模型提供了参考。     

黄土坡面径流冲剧侵蚀试验研究

通过径流冲刷试验，运用能量守恒原理，分析了坡面土壤侵蚀率（Dr)与径流能耗（ΔE）之间的关系，建立了给定土壤条件下坡面土 侵蚀率估算模型，结果表明，坡面土壤侵蚀的发生具有一定的临界能量条件，以径流能耗作为土壤侵蚀形成的临界参数具有明确的物理意义，当径流能耗大于7．387J时坡面开始有侵蚀发生。     

Transformation of the Bryansk Paleosol in Microdepressions in the Center of the East European Forest-Steppe during the Maximum of Valdai Glaciation and in the Holocene

Eurasian Soil Science - Recent and Late Pleistocene soils of the central forest-steppe in the East European Plain have been studied. The main objective of the work is to reveal changes in the...     

Changes in the structure of the rhizosphere complex of actinomycetes in the ontogenesis of winter rye

Changes in the taxonomic structure of actinomycetes in the rhizosphere of winter rye (Secale cereale L.) growing on acid soddy-podzolic soil were studied. During the first stages of ontogenesis of winter rye, the rhizosphere complex of mycelial prokaryotes was characterized by a relatively level generic structure (with respect to the indices of abundance and frequency of particular genera), low values of the species diversity, and low domination frequency of the species from the Streptomyces genus. The numbers and species diversity of the streptomycetes increased during the further growth of the winter rye, so that streptomycetes became a dominant group in the complex of the rhizosphere actinomycetes. According to the two-way ANOVA, the population density of the Micromonospora and the Streptosporangium genera in the rhizosphere was mainly dictated by the winter rye variety, whereas the population density of the streptomycetes depended on the particular stage of the winter rye development. The differences between the actinomycetal complexes characteristic of different varieties of winter rye at the early stages of its development was leveled by the end of the winter rye growth.     

Evolution of forest pedogenesis in the south of the forest-steppe of the Central Russian Upland in the Late Holocene

The Late Holocene stage of forest pedogenesis has been studied on the interfluves along river valleys in the forest-steppe zone of the Central Russian Upland. The development of gray forest soils from the former chernozems as a result of the Late Holocene advance of forest vegetation over steppes is discussed. It is argued that the climatic conditions of the Subatlantic period were unstable, so that multiple alternation of forest and steppe vegetation communities took place. This specified a complex character of soil evolution upon contrasting substitution of forest pedogenesis for steppe pedogenesis. On the interfluves near the natural drainage network (balkas, ravines, and steep slopes of river valleys), the climate-driven dynamics of forest and steppe vegetation with corresponding changes in the character of pedogenesis could take place during the entire Holocene, which is reflected in a lower thickness of humus profiles and deeper leaching of carbonates from chernozems of the Early Iron Age in comparison with their analogues formed under steppe cenoses in central parts of the interfluves. Two variants of the evolution of gray forest soils can be suggested: the pulsating evolution typical of balkas and interfluves near river valleys and the continuous progressive evolution typical of automorphic (plakor) positions in central parts of the interfluves.     

Accumulation of chemical elements in the raised peatbogs of the subtaiga Trans-Urals in the Holocene

The results of studying the variability of the geochemical parameters of the layers of the Sartamskii upland peatbog in the south of Tyumen oblast based on the radiocarbon time scale are given. Four basic types of peat and stages of peat deposits formation in the Holocene are distinguished: the organomineral layer of the sediments in a paleolake (up to 5065 ± 60 years ago), the low moor layer (4300–4900 years ago), the transitional layer (3100–4300 years ago), and the high moor peat (250–3100 years ago). The upper peat layer (last 200–300 years) significantly differs from its main portion; in particular, it is characterized by an increased ash content and the accumulation of a number of elements. The relationship between the various characteristics of the deposit is analyzed using principal component analysis, and the conditions of the formation of the peat deposit in different time periods are estimated, including the climatic conditions (in relative units). The anthropogenic signal of the accumulation of some elements in wetland systems is identified.     

论图书馆数字馆藏资源建设中亟待解决的问题

论述数字馆藏的产生、概念和特点,分析数字馆藏资源建设中存在的问题,探讨数字馆藏资源建设中应采取的策略。     

Variations in the composition of the sap of zea mays with the increase in osmotic pressure of the nutritive solution

The alterations are studied which are produced in the content of mineral elements and organic fractions of sap with the increase in the osmotic pressure of the nutritive solution at levels of 2.0; 3.5 and 5.0 atm., obtained through the addition to the nutritive solution either of magnesium sulphate or PEG‐4000.

Through the effect of the osmotic pressure, the transformations are modified of the nitrogen and mineral phosphorus at organic fractions experience a series of modifications which produce different values in the Nm%TSN and Pm%TSP ratios with respect to control. Through action of the specific effect of magnesium sulphate, the reducing sugars concentrations in sap having an important increase.     

Seasonal changes in the communities of microorganisms and algae in the litters of tree plantations in the steppe zone

Specific structural and dynamic parameters of communities from various ecological and trophic groups of microorganisms and algae in the litter of artificial tree stands were studied using the example of the Staro-Berdyansky Forest in the steppe zone of Ukraine. The composition of the communities was shown to vary by seasons and depend on the forest-forming woody species. In spring, in all the litters, the maximal number of actinomycetes and aminotrophs was recorded; in the leaf litter, the number of phosphate-mobilizing organisms was also the largest. In summer, the development of cellulolytic organisms, ammonifiers, and nitrogen-fixers was intensified; in autumn, the number of micromycetes and oligotrophic organisms decreased. The composition of dominants, the species richness of algae and their abundance also varied by seasons. Representatives of the Chlorophyta division predominated. The highest species richness of algae was characteristic of the spring litter samples, and their number, for the spring and autumn ones. The positive correlation was established between the numbers of micromycetes and oligotrophs, micromycetes and algae. The negative correlation was found between the numbers of micromycetes and actinomycetes, cellulose-decompose bacteria and algae in the litters.     

近50年博斯腾湖水位变化特征分析

以干旱区博斯腾湖为研究对象,依据博斯腾湖1956—2012年期间的水位监测数据,采用小波分析及MannKendall(M-K)趋势检验等统计学方法,揭示了近50a博斯腾湖水位变化趋势及规律。结果显示:博斯腾湖1956—2012年水位变化分为3个阶段下降(1956—1987年)—上升(1988—2002年)—下降(2003—2012年),其中1956—1987年水位下降了3.39m;1988—2002年上升了3.7m;2003—2012年再次下降了3.21m。水位总体上呈现出显著的下降趋势,且通过了α=0.05时的显著性检验。就其周期性变化规律而言,博斯腾湖水位存在18a的主周期,而38a的周期由于水位资料序列有限难以确定,需要更长的资料序列进行分析验证。     

Changes in the physical properties of soils in the Kamennaya Steppe under the impact of shelterbelts

The physical properties of ordinary chernozems and meadow-chernozemic soils under different land management practices (maple, larch, birch, and pine sections of the shelterbelts; continuous (since 1959) fallow; and arable field (since 1952)) were studied in the Kamennaya Steppe. The soils had favorable physicochemical properties, light clayey texture, and high microaggregation independently from the type of land management. The long-term impact of the shelterbelts improved the soil structure in the upper part of the humus horizon: the content of agronomically valuable aggregates increased, the content of coarse aggregates (>10 mm) decreased, the aggregation coefficient increased by 3.7–4.3 times, and the water stability of the aggregates became by 8–12% higher. The soils under the shelterbelts were characterized by minimum values of the bulk density and solid phase density and by maximum values of the total, active, and air porosities. At the same time, no considerable differences between water reserves in the studied range of soils were detected. The ratio of the optimum productive water range to the active (productive) water range (OPWR/AWR) within the upper soil meter varied from 0.42–0.44 to 0.45–0.54. This points to changes in the character of perched water: the content of intra-aggregate capillary-perched water decreases, and content of film perched water increases down the soil profile.     

Quality of used-snow discharged in the ST-Lawrence river,in the region of the Montreal Harbor

Snow disposal creates problems each year in Montreal. Snow dumping in water courses is favored due to both esthetic and economic considerations. Used snow must be considered as a potential pollutant. Its impact on the aquatic receiving environment is not well known. With river dumping in progress, snow samples were collected at 3 sites: Concorde Bridge, and at piers 30 and 52 in Montreal Harbor. Analysis of 28 routine parameters demonstrated that the quality of snow ultimately dumped in the river varies considerably according to its sources and the time it remains in the streets. Used-snow from residential areas was shown to be less polluted than the snow from commercial areas. Furthermore, from the total number of sampled districts, used-snow dumped at pier 30 appears to be relatively more polluted as it originated from downtown areas where vehicle circulation is more dense. Heavy metals in particles sizes between 0.45 and 63 μm represented more than 70% of the measured suspended solids which reflects the risk of bioaccumulation via benthic organisms. Principal component analysis of present data suggests that with analysis of chlorides, suspended solids and Pb alone, it is possible to approximately determine the quality of used-snow.