藏东南高寒区尼洋河河谷地带不同土地利用方式土壤抗蚀性研究

土壤抗蚀性是评价土壤侵蚀潜在发生可能性的重要综合性指标,研究高寒河谷地带不同土地利用方式土壤抗蚀性为土地利用模式优化和资源整合提供理论依据.本文应用主成分分析法对藏东南高寒区尼洋河流域5种不同土地利用方式下的3大类、13个土壤抗蚀性指标进行分析研究.研究结果表明:土壤团粒类指标和有机质能很好地反映土壤抗蚀性,0.25 mm水稳性团聚体质量分数、0.5mm水稳性团聚体质量分数、0.25 mm非水稳性团聚体质量分数、水稳性指数、平均重量直径、团聚体结构破坏率、有机质7个指标对土壤抗蚀性的影响最为明显,是表现不同土地利用方式土壤抗蚀性的最佳指标.各抗蚀性指标值基本表现出(0～15)cm(16～30)cm规律.通过建立权重求和模型发现0～15 cm表层土壤抗蚀性能远远大于16～30 cm;最终,通过叠加法得出不同土地利用类型土壤抗蚀性评价从强到弱顺序为:灌木林地(SL)、天然林地(NF)、农耕地(CL)、河滩林地(BL)、人工林地(AF).     

喀斯特石漠化地区不同治理措施下的土壤抗蚀性研究——以贵州毕节石桥小流域为例

对喀斯特山区不同治理措施下的石漠化演化过程土壤抗蚀性分析研究,结果表明:采用不同治理措施后,强度石漠化土壤抗蚀性优于其他等级石漠化土壤,潜在石漠化土壤抗蚀力最差.石漠化土壤抗蚀性大小顺序为原生样地、强度石漠化、轻度石漠化、中度石漠化、潜在石漠化.采用土壤有机质含量、EVA、结构体破坏率、＞0.25 mm水稳性团粒含量、＞0.5 mm水稳性团粒含量、团聚度、分散率、侵蚀率、＜0.001 mm粘粒分散系数等指标,较好地表征喀斯特山区石漠化土壤的抗蚀性.     

喀斯特石漠化地区退耕模式对土壤团聚体组成和稳定性的影响

探明贵州花江—关岭喀斯特石漠化地区不同退耕模式对土壤团聚体组成和稳定性的影响,为石漠化地区不同植被恢复模式的水土保持效益评估提供科学依据。选取喀斯特石漠化地区耕地(对照)、乔木林地和花椒林地土壤为研究对象,采用湿筛法测定0～40 cm土层土壤团聚体组成,计算0.25 mm水稳性团聚体含量(R_(0.25))、平均重量直径(MWD)、几何平均直径(GMD)和分形维数(D)等团聚体指标。结果表明:1)耕地转变为乔木林地和花椒林地显著增加了粗大团聚体(2 mm)含量(P0.05),显著降低了2 mm粒径团聚体含量(P0.05);2)土壤R_(0.25)、MWD和GMD值表现为乔木林地花椒林地耕地,土壤分形维数D值则相反;3)退耕后土壤团聚体稳定性的增加主要与粗大团聚体含量增加有关,2 mm和0.25 mm粒径是土壤团聚化过程中关键的临界点;4)退耕后,土壤团聚体含量和稳定性指标的变化幅度随土层深度的增加而减小,表明表层土壤团聚体组成和稳定性对土地利用变化的响应更为敏感。     

黄淮地区不同土地利用方式下土壤团聚体特征

选取三种土地利用方式(耕地、林地和草地)0-100 cm土层土壤为研究对象,采用湿筛法和干筛法通过计算0.25 mm大团聚体的比例、平均重量直径和几何平均直径分析土壤团聚体粒级分布和稳定性.不同土地利用方式下,土壤机械稳定性团聚体以0.25-0.5 mm粒级团聚体比例最低,在0-40 cm土层以5 mm粒级团聚体比例最高;土壤水稳性团聚体以0.25 mm粒级团聚体比例最高,各土层0.25-0.5 mm粒级团聚体比例最低.三种土地利用方式下,土壤团聚体机械稳定性水稳定性总体表现为林地和草地高于耕地.综合分析表明,林地土壤团聚体稳定性较高,耕地土壤团聚体稳定性表现最差.     

兰州窦家山典型坡面土壤水分、有机质含量及抗蚀性相关关系研究

通过取样实验和数据分析,研究了窦家山典型坡面五种不同植被类型下的土壤含水量和土壤有机质含量变化规律以及其与土壤抗蚀性之间的关系,为窦家山及兰州地区的水土流失防治提供参考措施.研究发现,在相同的土壤剖面深度和坡位条件下,不同植被类型土壤含水量大小顺序为银白杨侧柏柽柳白沙蒿醉马草,土壤有机质含量与含水量呈现负相关;相同条件下,不同植被类型有机质含量大小顺序为醉马草白沙蒿柽柳侧柏银白杨,不同植被类型有机质含量与大于0.25mm的水稳性团聚体含量均呈正相关关系;水稳性土壤团聚体含量大小顺序与有机质含量大小顺序相一致.大于0.25mm粒级水稳性团聚体含量越高,土壤抗蚀性越强,即水土流失量越少.从而有机质含量越高,土壤抗蚀性越好.结果表明,醉马草或白沙蒿的种植有利于窦家山的水土保持工作.     

汾河南内环桥-南中环桥河道土壤稳定入渗率变化规律的试验研究

通过分析在汾河南内环桥至南中环桥河道段进行的双环垂直入渗试验和颗粒分析试验,探讨了该河段的土壤稳定入渗速率和土壤颗粒组成之间的变化规律.研究结果表明:在土壤颗粒组成中,土壤水稳性团聚体质量分数和土壤稳定入渗速率的相关性最大.试验结果对于确定二期工程防渗措施设计和工程完成后管理运行有实际的应用价值.     

露天煤矿排土场土壤抗冲性影响因素分析

为了深入研究土石混合介质土壤侵蚀过程机理,加快开发建设项目水土流失的预测与预报,采用改进的原状土水槽冲刷法,研究了露天矿排土场土壤理化性质与土壤抗冲性的关系。结果表明:土壤抗冲指数与容重之间呈显著的负相关,与总孔隙度和毛管孔隙度之间呈极显著正相关,与砂粒含量呈极显著负相关,与粘粒含量呈显著负相关,与大于0.25 mm水稳性团聚体含量呈显著正相关,与2~1 mm水稳性团聚体含量和1~0.5 mm水稳性团聚体含量呈显著负相关,与土壤初渗率和稳渗率呈显著正相关,与有机质、全氮和全钾含量呈显著相关关系。该研究可为开发建设项目土壤侵蚀的预测建模提供理论依据。     

石漠化地区石灰岩喀斯特林地土壤抗蚀性研究

对贵州中部石灰岩喀斯特地区3种林分（常绿阔叶林,构树林和灌木林）林地土壤的抗蚀性指标进行主成分分析,并以农地土壤作对照,研究表明,用抗蚀性指标主成分分析综合指数表明3种林分林地土壤抗蚀性为：阔叶林（88.90）〉构树林（77.02）〉灌木林（62.69）;表层土壤抗蚀性（97.14）高于亚表层土壤抗蚀性（67.30）,土壤抗蚀性从表层向下呈下降趋势。通过聚类分析可将贵州中部石灰岩喀斯特不同土地利用类型不同层次的8土壤样本划分为抗蚀性强度不同的3类,与评价结果一致。     

凤阳山主要林分类型土壤团聚体及其稳定性研究

【目的】探究凤阳山自然保护区的林地土壤团聚体组成及其影响因素,为恢复与保护土壤资源提供一定的理论依据。【方法】以浙江省凤阳山自然保护区内海拔1 300～1 400 m范围内主要林分类型(阔叶混交林、针阔混交林、杉木林、竹林)林地为对象,测定不同土层土壤基本理化性质和水稳定性团聚体粒径分布及其含量,分析土壤理化性质对土壤团聚体及其稳定性的影响。【结果】①4种林分土壤水稳定性大团聚体(WSA)(≥0.250 mm)含量均在90%以上。土壤水稳定性大团聚体含量及平均质量直径(MWD)和几何平均直径(GMD)均以杉木林的最大,竹林的最小。②通过非度量多维标度(NMDS)排序分析,阔叶混交林、针阔混交林和杉木林对≥2.000 mm粒级土壤团聚体影响较大,竹林对≥0.053～0.106 mm粒级的土壤团聚体的影响较大。③土壤密度与土壤MWD及GMD之间均呈显著正相关,与土壤分形维数(D)呈显著负相关。非毛管孔隙度与土壤MWD及GMD之间均呈显著负相关,与土壤D呈显著负相关。【结论】林分类型较土层深度对土壤团聚体粒级组成及稳定性的影响更显著,土壤密度及非毛管孔隙度等土壤理化性质较土壤总孔隙度、毛管孔隙度及总有机碳含量等对土壤团聚体粒级组成及稳定性的影响更显著。     

寒温带4种森林类型土壤团聚体有机碳氮特征

【目的】 大兴安岭是我国唯一的寒温带地区,森林资源丰富,但大兴安岭地区土层较薄,且存在永冻层,对于该地区土壤结构、养分循环存在巨大影响。探讨该地区土壤团聚体的结构组成和有机碳、氮的含量与分布规律,了解不同粒径团聚体对土壤有机碳、氮的固存与保护作用,为深入研究我国寒温带地区土壤结构与碳氮循环提供依据。【方法】 在黑龙江大兴安岭地区,以我国寒温带4种主要森林类型(兴安落叶松林、樟子松林、山杨林、白桦林)为研究对象,测定生长季林地0~5、≥5~10和≥10~20 cm土层粒径<0.053、≥0.053~0.250、≥0.250~0.500、≥0.500~1.000和>1.000 mm水稳性团聚体的分配比例并结合有机碳、氮含量,分析各粒径团聚体有机碳、氮对土壤总有机碳、全氮的贡献率,进行多因素方差分析。【结果】 ①樟子松林、山杨林和白桦林0~10 cm土层和兴安落叶松林0~5 cm土层以大团聚体(粒径≥0.250 mm)为主,占50%以上,随着土层的加深,大团聚体质量分数下降,各个林型生长季中期大团聚体质量分数均高于初期和末期,且阔叶林大团聚体质量分数高于针叶林。②团聚体有机碳含量与全氮含量呈现出大致相同的变化规律,4种森林类型以粒径≥0.500 mm团聚体有机碳、全氮含量较高,大致表现为随粒径的减小含量递减。阔叶林团聚体有机碳、全氮含量比针叶林的高,且阔叶林的在生长季中后期含量相对较高,而兴安落叶松林的呈波动式变化趋势,樟子松林的则以生长季前期含量较高。③4种森林类型0~10 cm土层,团聚体有机碳、全氮以粒径≥0.500 mm团聚体贡献率较高,最高达到90%;随着土层的加深,≥0.250 mm的大团聚体的贡献率下降,≥10~20 cm土层以粒径<0.250 mm的微团聚体贡献率最高。④森林类型、土层和月份对土壤团聚体组成和团聚体有机碳、全氮含量均具有显著影响,且粒径≥0.500 mm团聚体有机碳、全氮含量与对应粒径团聚体含量呈正相关,粒径>1.000 mm团聚体有机碳、全氮含量与该粒径团聚体含量呈极显著正相关。【结论】 森林类型、土层和月份的变化均对土壤团聚体组成及其结合的有机碳、全氮含量产生影响,阔叶林大团聚体含量以及团聚体结合的有机碳氮含量均高于针叶林。4种森林类型以生长季中期大团聚体含量更高,阔叶林团聚体有机碳、全氮含量在生长季中后期较高,针叶林则在生长季内呈波动式变化趋势。随着土层的加深,大团聚体含量、团聚体有机碳、全氮含量以及大团聚体贡献率均逐渐降低。本研究区粒径≥0.500~1.000 m和>1.000 mm团聚体是有机碳和全氮的主要载体。由此可见,寒温带4种森林类型团聚体组成及其结合的有机碳、全氮特征各异,在一定程度上反映了寒温带主要森林类型下的土壤结构与碳氮固存特征。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-