“俄国文学在原有水平上向前发展”——谢·丘普里宁访谈录

1996年11月19日,北京大学俄语系教授、俄罗斯文学研究专家任光宣先生在莫斯科《旗》杂志编辑部对该杂志主编丘普里宁进行了采访。现将这次访谈的记录刊登如下。 任光宜(以下简称任):有人说,俄国文学最近十年的发展水平降低了,您是怎么看的? 丘普里宁(以下简称丘):俄国文学在最近的十年里存在、发展着,虽然出现了一些新现象、新变化,但她基本上保持着原有的水平,在原有的水平上向前发展,没有提高。

浅谈江南园林特色的运用

天津市塘沽区河滨公园一南园,位于公园内东部,南北长约240米,东西宽70-90米,占地21400平方米,原来大部分是苇塘,本着因地制宜的原则,尽量利用原有水塘和冬季地热回水,规划设计江南古典山水园林。在规划设计中结合实际情况主要在突出江南园林特色上做了如下几个方面工作。

介绍一种简便的甘薯杂交方法

甘薯杂交育种,在田间操作费力、费时,管理不便,存在诸多困难。这里介绍一种简便易行的方法——水培法。“水培法”,就是利用南方(北纬23℃以南地区),多数甘薯能自然开花的优势,将见到已经现有小花蕾的,而又是我们要作亲本的甘薯蔓取回。剪成约33厘米左右长,一端插在玻璃瓶内(亦可用啤酒瓶),内盛满清水,以后注意经常添水,保持原有水分。约经7—10天左右,换一次新水,并将薯蔓适当见阳光,以促生根成活和自然开花。当甘薯开花时,可选择适合我们需要的亲本进行杂交,操作十分方便。杂交后约25—30天(依温度高低不同),种子成熟,可以采摘备用。

Recent developments in the use of single-atom catalysts for water splitting

Electrochemical water splitting is regarded as the most promising approach to produce hydrogen.However,the sluggish electrochemical reactions occurring at the anode and cathode,namely,the oxygen evolution reaction(OER)and the hydrogen evolution reaction(HER),respectively,consume a tremendous amount of energy,seriously hampering its wide application.Recently,single-atom catalysts(SACs)have been proposed to effectively enhance the kinetics of these two reactions.In this minireview,we focus on the recent progress in SACs for OER and HER applications.Three classes of SACs have been reviewed,i.e.,alloy-based SACs,carbon-based SACs and SACs supported on other compounds.Different factors affecting the activities of SACs are also highlighted,including the inherent element property,the coordination environment,the geometric structure and the loading amount of metal atoms.Finally,we summarize the current problems and directions for future development in SACs.

Study on Water－Soluble Organic Reducing Substances：Ⅲ．Electrochemical Properties of Decomposition Products of Rice Straw and Their Interactions with Variable Charge Soils

Some electrochemical properties,such as PH,Eh,and voltammetric behavior,of the decomposition products of rice straw and the in eractions of these products with soils were studied.The PH,Eh,and amounts of organic reducing substances changed markedly during the 60-day anaerobic decomposition.pH decreased sharply to pH 5 on the tenth day and then increased gradually to 7 on the 45th day.The amouats of organic reducing substances increased almost synchronously with the fall of redox potential during the first 15 days.The differential pulse voltammetric(dpv) behavior changed not only in the peak current but also in the peak potential.The fractions with apparent molecular weights lower than 200 dations appeared to be active in dpv behavior.The electric charge of organic reducing substances was closely related to the decomposition stage.The 6th day of incubation was the crucial time before and after which the major part of the components was negatively charged and positively charged, respectively.The group with a low apparent molecular weight and a negative charge was the main components responsible for the lower anodic peak potentials.They were oxidized first during the interactions of the organic reducing substances with soils.

Effective stress law for rock masses and its application in impoundment analysis based on deformation reinforcement theory

Reservoir impoundment is related to several hydraulic engineering concerns,including irreversible valley contractions,landslides and reservoir-induced earthquakes.However,these phenomena,such as valley contractions,are hardly to be explained by the conventional method.The scientific understanding of water effects during impoundment and their hazards to hydraulic structure are needed.The effective stress law for fissured rock masses is introduced in the elasto-plastic model employing the Drucker-Prager criterion and implemented in the three dimension(3D)nonlinear finite element method(FEM)program Three-dimensional FINite Element(TFINE).The slope deforms towards river-way during impoundment since the increasing pore pressure in fissures changes stress state and leads to additional plastic deformation in the rock materials.The value of Biot coefficient and the influence of water on rock materials are discussed in detail.Thus,the mechanism of slope deformation during the impoundment of Jinping-I arch dam is revealed,and the deformation is accurately measured.The application of the effective stress law provides a method to consider stress assessment,deformation evaluation and stability estimate of hydraulic structures during the impoundment process.This is a beneficial exploration and an improvement of hydraulic engineering design.

Study on Water-Soluble Organic Reducing Substances: II. Organic Reducing Substances Produced from Anaerobic Decomposition of Milk Vetch (Astragalus sinicus L.)

The characteristics of electric charge and molecular weight distribution,oxidation-reduction regimes,e.g.Eh and amounts of organic reducing substances produced by milk vetch during anaerobic decomposition process,were studied by using electrochemical methods.Interaction between soils and organic reducing substances was also observed.The results indicate that the organic reducing substances were mainly the organic compounds with negative and amphoteric charges,which were distributed in two groups at anodic peak potentials of 0.25 and 0.69 volt in differential pulse voltammograms,respectively.Their apparent molecular weights are all less than 700 daltons,in which those active in oxidation-reducion reaction were distributed in the fraction with apparent molecular weight less than 200 daltons.The organic reduction substances can be oxidized by manganese oxides in their interaction with soils.

Changes in the Thermal and Hydraulic Regime within the Active Layer in the Qinghai-Tibet Plateau

The change trends of air temperature,precipitation and evaporation from 1999 to 2008 shows that the climate in the Qinghai-Tibet Plateau permafrost region had become warmer.The analysis of the systematic active-layer data monitoring network along the Qinghai-Tibet Highway indicated that the active-layer thickness had been increasing and the soil temperature was rising.The soil temperature was rising in winter but not at the end of spring or during the entire summer.With thickening and warming of the active layer,the liquid water content of the active layer had an obvious downward migration and liquid water content in the top horizons decreased,but in the deeper horizons it increased.

Development of a bismuth-based metal-organic framework for photocatalytic hydrogen production

A novel 3 D bismuth-organic framework(called Bi-TBAPy) single crystal was synthesized by employing 1,3,6,8-tetrakis(p-benzoic acid)pyrene(H4TBAPy) as an organic linker. The study demonstrates that the Bi-TBAPy not only possesses good chemical stability and suitable band edge positions for promising photocatalytic H2 evolution, but it also exhibits a typical ligand-to-metal charge transfer for favorable charge separation. The photocatalytic H2 evolution rates on the as-obtained Bi-TBAPy with different cocatalysts modified were examined with triethanolamine as the sacrificial reagent. Based on this, the hydrogen evolution rate of 140 μmol h-1 g-1 was obtained on the optimized sample with a loading of 2 wt% Pt as a cocatalyst. To the best of our knowledge, this is the first bismuth-based metal-organic framework(MOF) that functions as an effective photocatalyst for photocatalytic water reduction. Our study not only adds a new member to the family of photocatalyst materials, but also reveals the importance of cocatalyst modification in improving photocatalytic activity of MOFs.

Influence of the Type of Fertilization on Nitrogen Balance of the Mountain Meadow

Among fertilizer ingredients nitrogen is the one noted for biggest losses because its susceptibility to volatilize to the atmosphere and to be leached away from the soil. These losses depend on the level and mode of fertilization. It appears that every year in Poland river waters transport to the Baltic Sea from the whole area about 180 thousand tons of the nutrient. The largest portion of this load is ascribed to agriculture. This study focused on the highland areas, which are commonly seen as a water supplying region owing to the fact that they cover about 35% of water need in the authors＇ country. Specificity of grassland fertilization in these lands is high contribution of natural fertilizers including dunging with fresh manure left by penned animals, particularly by sheep. Authors decided to assess the influence of dunging by folded sheep on meadow nitrogen balance and on its concentration in percolating water. It was demonstrated that a nitrogen balance was highly negative for each object, so the grassland plants supplied their needs in large part with nitrogen from mineralization of soil organic matter. Relatively high loads of nitrogen leached out of the folded objects indicate that nitrogen from mineral fertilizers is better utilized by grassland herbage and thus is much safer for soil and water environment.

Applications of Water Sensitivity In Situ Remediation at Saltwater-Freshwater Interface

Based on the laboratory experiments with the saltwater and freshwater replacing each other in the level sand column, taking the kaolin, illite, smectite, bivalent hydrargyrum ion （Hg^2＋） and ＂phenol （C6H5OH） as examples, this paper studies the applications of water sensitivity in situ remediation in saltwater-freshwater transition zone. In the water sensitivity process, the release and migration of clay minerals can make the hydraulic conductivity （HC） decrease and pollutants remove. A new type of low penetrable or impenetrable purdah can be built by adding clay minerals into the sand media to replace the underground concrete impenetrable wall to prevent seawater intrusion, and a number of the heavy metals and organic pollutants in the sand media can be removed by in situ remediation. The results show that the content of kaolin and illite influences the water sensitivity process slightly, and HC of the sand columns descends from 0.011 cm/s to 0.001 4 cm/s and 0.001 2 cm/s respectively even if the content reaches 12% （weight ratio, sic passim）. However, for smectite, HC descends sharply to about 1 × 10^-8 cm/s when its content reaches 4%, and no water can flow through the sand columns beyond 5%. The particle release and migration processes can remove the Hg^2＋ and C6HsOH out of the sand columns efficiently, the removing rate of Hg^2＋ is 31.68% when the freshwater and saltwater are filtered through the sand columns polluted by Hg^2＋, while it is 67.55% when the water sensitivity occurs. With the same method, the removing rates of C6H5OH under the fluid flow and water sensitivity are 55.71% and 43.43% respectively.

Influence of litter layer on ecological environment in northeastern leymus chinensis grassland of China

In this paper, we adopted simulation method to discuss influences of litter layer on plants habitat in grassland. Results indicated that ground surface evaporation, soil moisture, surface temperature, soil pH, soil bulk density and soil porosity were all strongly related to the litter quantity. Potassium （K） and organic materials in the soil covered by litter layer were higher than those in the soil uncovered by litter layer. With 100 g.ln-z increase of litter, the percentage of organic materials increased by 17.9%, nitrogen （N） increased by 7.6%, phosphor （P） increased by 26.4%, and K increased by 3.8%. With the litter accumulation amounting up to 600 g-m-2, the percentage of organic materials increased by 1.8 times, N increased by 81.5%, P increased by 1.8 times and K increased by 26.4%. According to the expected coefficient method of optimization, a mathematical model was established about the optimal accumulation quantity of litter.

Free polyamine content during algal bloom succession in the East China Sea in spring 2010

We measured the concentrations and distribution of major polyamines(spermine, putrescine and spermidine) in seawater during successive spring algal blooms in an area of frequent harmful blooms in the East China Sea. Spermine, putrescine, and spermidine concentrations were analyzed by high performance liquid chromatography and ranged from 1–64, 7–81, and 0–19 nmol/L. Spermine was present at the highest concentrations, followed by putrescine and spermidine. In late April, when a diatom bloom dominated by Skeletonema costatum dispersed, polyamine concentrations increased, presumably as a result of diatom decomposition. In early May, when a dinoflagellate bloom dominated by Prorocentrum donghaiense occurred, the polyamine concentration decreased from the level seen in late April. The abundant polyamines that decomposed and were released during the diatom bloom in late April may have promoted the growth of P. donghaiense, resulting in its dominance.

Vegetation and Topographic Control on Spatial Variability of Soil Organic Carbon

Soil organic carbon (SOC) is one of the most important parameters affecting the hydraulic characteristics of natural soils. Despite being rather easy to measure, SOC is known to be highly variable in space. In this study, vegetation, climate, and morphology factors were used to reproduce the spatial distribution of SOC in the mineral horizons of forest and grassland areas in north-western Italy and the feasibility of the approach was evaluated. When the overall sample (114 samples) was analyzed, average annual rainfall and elevation were significant descriptors of the SOC variability. However, a large part of the variability remains unexplained. Two stratification criteria were then adopted, based on vegetation and topographic properties. We obtained an improvement of the quality of the estimates, particularly for grasslands and forests in the absence of local curvatures. These results indicate that the spatial variability of soil organic matter is scarcely reproducible at the regional scale, unless an a-priori reduction of the heterogeneity is applied. A discussion on the feasibility of applying stratification criteria to deal with heterogeneous samples closes the paper.