Native legume establishment on acidic coal mining overburden at Collie,Western Australia

Nitrogen is often provided to impoverished overburden dumps through the establishment of legumes. Low indigenous soil nutrient levels, summer drought conditions and an acidic mining overburden represent major obstacles to successful rehabilitation of open-cut coal mining at Collie in southwest Western Australia. In this study,Acacia pulchella, a native Western Australian species often used in rehabilitation of mined lands, was shown to nodulate and grow in coal mining overburden with pH values less than 4.0 under glasshouse conditions. Plant growth (both top and root dry weight), nodule fresh weight, and nodulation success was best at a pH near 5.0, a value only slightly lower than the typical soil pH of the native jarrah (Eucalyptus marginata) forest. Acetylene reduction rates were reduced by acidity and ranged from 8.2 m C₂H₄g^–1hr^–1 at pH 6.77 to 3.0 m C₂H₄g^–1hr^–1 at a pH of 3.98. Four additional plant species were found to occur and to nodulate on acid overburden material at Collie.     

The sensory basis of prey location by the California leaf-nosed bat Macrotus californicus (Chiroptera: Phyllostomidae)

Summary Macrotus californicus, an insectivorous bat, captures prey on the ground, and shows great sensory flexibility in hunting for prey: it uses high frequency, low intensity, frequency modulated echolocation to locate prey in total darkness, however data from this study suggest that it uses vision preferentially, and switches off its echolocation when adequate illumination is available. When souncs of prey are available it exploits these also. It uses echolocation only 50% of the time at 4.2x10^-2 mL, comparable to ground luminance on a brightly moonlit night, and employs vision even at 10^-3 mL.     

水利旅游开发研究——以淠史杭灌区为例

水利旅游是水利工程综合效益的体现。淠史杭灌区为世界7大人工灌区之一，是发展水利旅游的典型区域。对淠史杭灌区开发水利旅游的资源条件、现状和存在的问题进行了较为系统的分析，提出了联动开发、展示水利文化、合理整合资源、多种开发模式等发展策略。     

A RATIONALE FOR THE REGIONALIZATION OF PUBLIC WATER SYSTEMS1

ABSTRACT. A rationale is set forth for requiring and/or encouraging the consolidation or regionalization of all systems beneath certain population size levels based on the small water systems’ capability to produce an adequate supply of safe drinking water at a reasonable cost to customers. Estimates for basic costs of water service including personnel, other operation and maintenance and capital are made and a range of water rates is suggested based on reasonableness and acceptability to customers. Guidelines are then drawn for a moderate rate of $10.00 per month and an upper limit rate of $15.00 per month to show the sizes at which public water systems might be expected to achieve fiscal viability. Finally, recommendations are made to State and Federal governmental agencies concerning possible legislation, plans and programs to achieve better public water service through the regionalization or consolidation of small public water systems.     

Electrochemical performance of magnesium alloy and its application on the sea water battery

The magnesium sea water battery belongs to a kind of reserved battery, which takes the active metal such as magnesium alloy as the anode based on the sea water as the electrolyte. Experiments of magnesium alloy sea water battery were carried out and its electrochemical performance was studied. Thin sheets of Mg-Al-Zn and Mg-Mn series of magnesium alloy were fabricated and used as the anode of magnesium battery. The discharging voltage and current were measured for different composition and thickness of Mg alloy sheet under various surface state, temperature as well as electrolyte. The effect of the temperature, the surface condition and the electrolyte to the electrical current and voltage were investigated. Anodic dissolution and mechanism of activation of Mg alloy anode were discussed based on surface microstructure observation. The feasibility to apply magnesium alloy sheet to highly effective sea water battery was verified.     

Coating of γ-Al2O3 on the stainless steel substrate by electrophoretic deposition method

γ-Al₂O₃ coatings were prepared on aluminum-free stainless steel (SUS304) by electrophoretic deposition method. Both X-ray diffraction and scanning electron microscopy were used to study the crystalline structure and morphological features of the coatings. Themo gravimetry-differential termal analysis (TG-DTA) is used to study the thermo-chimerical reaction behavior of coatings. Catalytic activity of coatings is determined by degrading of NO_x. The results indicated that the thickness of the coatings onto SUS304 could reach 5 μm without any exfoliation at optimized conditions. Catalytic properties of samples coated by electrophoretic deposition method were highly enhanced as compared with that of samples prepared by the dip coating method.     

普通及指示克里格法在水稻禁产区筛选中的应用

在对农产品产地进行监测基础上,以川东南水稻生产区为研究对象,探讨了普通克里格法及指示克里格法在农产品产地禁产区筛选中应用的可行性.研究区土壤监测统计结果表明,川东南水稻生产区以重金属Cd污染为主,区域Cd最高值为0.53mg·kg-1;监测点超过<土壤环境质量标准>(GB 15618-1995)2级标准值的比例达34.98%.探索性分析结果显示,研究区土壤Cd异常值较少,土壤Cd监测值及指示值实验半变异函数均为各向同性,采用人工干预条件下的基台值自动拟合法拟合普通及指示克里格实验半变异函数,并根据交叉验证结果确定分别采用带块金值的指数模型及带块金值的球形模型套合结构拟合普通及指示克里格实验半变异函数.通过普通和指示克里格插值结果筛选水稻禁产区后,应用误判率法评估了两种方法应用于水稻禁产区筛选的优缺点.结果表明,普通克里格法训练数据集的误判率为3.89%,验证数据集误判率为26.09%;指示克里格法训练集的误判率为0.78%,验证数据集误判率为21.73%,指示克里格法的估计精度要优于普通克里格法,更适合于研究区水稻禁产区的筛选.     

我国南方不同类型草地生产力及对气候变化的响应

为进一步明晰南方不同类型草地的碳源汇关系,预测未来气候情景下可能的碳循环特征,利用本地参数化的BIOME-BGC模型对2001~2010年低山丘陵草原化草甸、典型草山草坡和典型山地草甸样地净初级生产力(NPP)与净生态系统生产力(NEP)进行了模拟估算。不同类型草地的NPP和NEP 10年间变化趋势不同,低山丘陵草原化草甸、典型草山草坡和典型山地草甸的NPP平均值分别为357.17、232.4和191.96gC/(m2·a);NEP的平均值分别为3.25、21.28和81.96gC/(m2·a)。3种类型草地NPP与温度之间存在显著的正相关关系,NEP与温度之间存在着显著的负相关关系;本模型模拟的NPP和NEP与年平均降水量之间相关性不明显。未来气候情景C1P-1T1下(CO2浓度倍增,年均温增加2℃,降水减少10%),低山丘陵草原化草甸样地NPP增加26.93%,NEP增加160%;典型草山草坡样地NPP增加62.20%,NEP增加153%;典型山地草甸样地NPP增加135%,NEP增加206%。3种南方草地类型在未来气候情景下都将有一定的碳汇增长潜力,其中以典型山地草甸的碳汇潜力最为明显,与降水量相比受温度变化的影响相对较大。