含裂隙岩石裂纹扩展与剪切特性的数值研究*

为研究直剪条件下含交叉裂隙岩石的裂纹扩展模式和剪切特性,基于PFC2D研究直剪条件下含裂隙岩石的裂纹扩展模式和剪切特性。研究结果表明:直剪过程可分4个阶段:Ⅰ初始平静阶段、Ⅱ裂纹单一扩展阶段、Ⅲ裂纹复杂扩展阶段、Ⅳ破坏阶段;法向应力越大,Ⅱ,Ⅲ阶段的裂纹扩展程度受到抑制;岩石中含单裂隙时,随裂隙角度α的增加,抗剪强度的变化趋势基本一致,遵循先降后增的规律;含交叉裂隙时,当主裂隙角度α=120°,150°时,抗剪强度随次裂隙角度β的增加呈先减小后增大的趋势,抗剪强度最小值均出现在β=30°;加固含裂隙岩体时,预防裂隙或者潜在破坏面两侧的岩体产生位移差,使其加固后成为1个稳固整体,是避免岩体产生裂纹导致破坏的重要手段。     

龙岩大气颗粒物中多环芳烃源识别及污染评价

采用恒能量同步荧光法,研究了龙岩市区不同功能区冬、春季大气颗粒物中多环芳烃(PAHs)的污染状况和污染来源,并对不同功能区的PAHs含量进行了评价. 结果表明:龙岩市区各功能区大气颗粒物中ρ(PAHs)为278.95～ 718.25 ng/m3,且冬季高于春季. 根据PAHs中一些特征标志物的比值,可判断冬、春季市区内PAHs主要来源于汽车尾气和燃煤污染. 采用苯并［a］芘(BaP)及苯并［a］芘等效致癌浓度(BaPE)来评价3个功能区大气颗粒物中PAHs的污染状况显示,冬季3个功能区苯并［a］芘含量(ρ(BaP))均超过国家标准(10 ng/m3),且ρ(PAHs)均严重超标.      

邯郸市物质流分析

利用邯郸市统计年鉴数据和实地调研资料,采用城市物质流分析框架研究邯郸市2005年物质流全景和1993─2005年物质输入和输出结构的时间序列变化.结果表明:13年间邯郸市地区生产总值增长3.4倍,物质输入增长1.1倍,物质生产力增长1.1倍,由1993年的151.8元/t上升至2005年的320.9元/t,反映了邯郸市前期经济发展与资源投入具有明显的“脱钩"现象;另一方面,邯郸市仍然遵循着“高投入、高排放"的发展模式,2005年物质净存量仅占全年物质通量的12.2%,大部分物质在开采当年并不进入经济系统而直接排放到生态系统中;同时,邯郸市经济发展的对外依存度逐年升高,从该市外调入的物质量所占比例由1993年的10.2%上升至2005年的39.2%,表明邯郸市经济发展将面临更大的资源      

区域环境中三氟乙酸富积多相传质模型研究

建立了描述挥发性有机物在大气、水、土壤和底泥等环境中动态分布的多相传质模型,并用于分析长江流域江苏段及太湖水系区域内三氟乙酸(TFA)在各环境相中的分布. 采集实测数据约300个,比较实测值与模拟值,对模型的可靠行进行验证. 建立了检测环境中微量TFA前处理及方法. 结果表明:多相传质模型能够正确描述研究区域内环境中的TFA分布. 在给定排放量变化规律的前提下,预测未来10年内研究区域环境水体中ρ(TFA)将接近100 ng/L,接近现阶段欧美发达国家主要水体中的ρ(TFA).      

Verification of the geographical origin of modeled air-mass trajectories by means of the isotope composition of rainwater during the SALLJEX experiment

The SALLJEX experiment was held during the summer 2002–2003. It consisted of three-dimensional observation of the atmosphere to study the structure of the low level jet along the eastern slopes of the Andes. Daily precipitation water samples were collected at two stations (Resistencia and Salta) in northern Argentina and isotope content was analyzed. The isotope data were used in conjunction with air parcel trajectories obtained from a 3-D kinematic model (3D-MTC) developed by the University of Sao Paulo, Brazil. Values of deuterium excess were related with air masses of continental origin, whilst low values were associated with air masses with longer oceanic trajectories. Furthermore, although data are scarce, results show that oxygen-18 and deuterium excess in rainwater are related with the occurrence of the low level jet.     

采空区冒落带内破碎岩体的渗流特征与渗透性试验研究

为探索采空区冒落带内破碎岩体中地下水的渗流特征,建立采空区冒落带内破碎岩体渗透系数与空隙率的相关关系,确定采空区冒落带内破碎岩体的渗透系数值,并基于采空区冒落带内破碎岩体的空隙分布特征与大孔隙非均质多孔介质的水流特征,设计了一套一维渗流柱,采用常水头稳态渗透法对采空区冒落带内破碎岩体的渗透性能以及不同空隙率破碎岩体的渗...     

凋落物覆盖及掩埋对不同质量的藜蒴种子萌发和幼苗生长的影响

以南亚热带常见的先锋乡土树种藜蒴(Castanopsis fissa)为研究对象.通过室内萌发试验,分析了种子质量、凋落物覆盖和掩埋对种子萌发及幼苗早期生长的影响.结果表明,藜蒴种子能否成功萌发并形成幼苗的决定性因素是种子的掩埋深度.掩埋显著抑制了藜蒴种子萌发及形成幼苗的过程,随掩埋深度的增大,这种抑制作用越明显.掩埋对幼苗的存活和生物量没有显著影响,但可提高幼苗根部生物量的分配.深度掩埋时,质量大的种子在幼苗形成过程中具明显优势;而置于土壤表层或浅埋的种子成苗率与种子质量的相关性较低.大质量种子形成的幼苗更易于存活,在生物量的积累方面也表现H{一定的优势.凋落物覆盖未抑制幼苗的出土,且对幼苗的存活和生长具有明显的促进作用,表现在可提高幼苗的相对生长率以及生物量的积累.另外,凋落物的覆盖明显提高了幼苗生物量在其冠部的分配.因而,若利用直接播撒藜蒴种子的方式改造南亚热带退化草坡.理论上应尽可能选用大质量的种子直接播种于地表,并覆以原有的地表凋落物,以促进藜蒴幼苗成功建立.     

Age- and state-dependent reproductive effort in male mountain goats, Oreamnos americanus

In mammalian polygynous mating systems, male reproductive effort consists mainly of male–male competition and courting of females, which entail substantial somatic costs. Males are thus expected to adjust their reproductive effort according to their age and condition. In this study, we examined how activity budgets of male mountain goats (Oreamnos americanus), a polygynous ungulate, varied with age in a marked population over two periods: (1) summers 1995–2006 and (2) ruts 2004–2006. We then assessed if the proportions of time spent in male–male competition and courtship behaviors were influenced by age-specific body mass and social rank during the rut. Males spent most of their time foraging and resting during summer, and rested more and foraged less with increasing age. During the rut, pronounced shifts in activity budgets occurred as juveniles (1–2 years) increased time spent foraging, whereas adults (≥3 years) increased standing and time spent in social interactions at the expense of foraging. At old age, reproductive effort either stabilized or decreased slightly, providing weak support for the ‘mating strategy–effort’ hypothesis, predicting that courtship behaviors should peak in prime-aged males. Age-specific body mass did not affect time spent in male–male competition, but was positively related with time spent in courtship behaviors, providing support for the ‘individual quality’ hypothesis, predicting that males with more resources at the start of the rut should spend more time in mating-related activities. Age-specific social rank did not affect reproductive effort. Surviving to prime age while increasing mass each year should thus allow male ungulates to gain greater ability to court estrus females.     

Qualitative analysis and quantitative simulation on Yin-Huang water salinization mechanism in Bei-Da-Gang reservoir

Yellow River water transfer for Tianjin is important in solving the water shortage in Tianjin, which facilitate economic development and social progress for many years. Fresh water drawn from Yellow River（ i. e., Yin-Huang water） becomes saltier and saltier when being stored in the Bei-Da-Gang reservoir. We qualitatively analyze the water salinization mechanism based on mass transfer theory. The main factors are salinity transfer of saline soil, evaporation concentrating, and the agitation of wind. A simulative experimental pond and an evaporation pond were built beside the Bei-Da-Gang reservoir to quantitatively investigate the water salinization based on water and solute balance in the simulative pond. 80% of increased [Cl^-] is due to the salinity transfer of the saline soil and the other 20% is due to evaporation concentrating, so the former is the most important factor. We found that the salinization of Yin-Huang water can be described with a zero-dimension linear model.     

乳化液膜法提取活性艳蓝KN-R工艺研究

利用表面活性剂TH-1、民用煤油、载体N235和内水相NaOH溶液组成的液膜体系,采用正交试验法,对提取活性艳蓝KN-R工艺进行了研究。结果表明:以5%TH-1,5%N235,10%NaOH,油内比Roi为1∶1.5的乳状液膜体系,处理初始浓度为6000mg/L活性艳蓝KN-R废水,在pH值为1,传质温度为25℃,乳水比Rew为1∶5的传质条件下,提取率可达94.8%。