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61.
62.
As the feature size of the CMOS integrated circuit continues to shrink, the more and more serious scattering effect has a serious impact on interconnection performance, such as delay and bandwidth. Based on the impact of the scattering effect on latency and bandwidth, this paper first presents the quality-factor model which optimises latency and bandwidth effectively with the consideration of the scattering effect. Then we obtain the analytical model of line width and spacing with application of curve-fitting method. The proposed model has been verified and compared based on the nano-scale CMOS technology. This optimisation model algorithm is simple and can be applied to the interconnection system optimal design of nano-scale integrated circuits. 相似文献
63.
研究pH和Ca(Ⅱ)对砷酸根在海水与NaCl介质中对水合氧化物和粘土矿物上交换吸附的影响:(1)在酸性条件下和海水及NaCl介质中,砷酸根在针铁矿上的交换率E(%)—pH曲线呈平顶峰型、在δ-MnO呈峰型、在粘土上分别呈双峰型和肩峰型。这是砷酸根存在多种形式与固体表面发生离子/配位子交换以及介质中阴离子竞争交换吸附共同作用的结果。(2)在碱性条件下的海水介质中,砷酸根与水合氧化物和粘土矿物的E(%)—pH曲线都呈V型,这是因为生成了具有一定结构的液—固界面三元络合物之故。(3)在NaCl介质中,Ca加入起促进作用,再次证明液—固界面三元络合物生成机理与V型曲线的内在关系 相似文献
64.
Robert J. Wilcock Graham B. McBride John W. Nagels Grant L. Northcott 《新西兰海洋与淡水研究杂志》2013,47(2):277-288
Abstract The Whangamaire Stream (North Island, New Zealand) has high concentrations of nitrate nitrogen (NO? 3‐N), biochemical oxygen demand (BOD5), and Kjeldahl nitrogen (TKN) as a result of catchment land use practices. The lower reaches of the stream drain intensively farmed land and have dissolved oxygen (DO) levels of 10–50% saturation. The dominant riparian vegetation, Apium nodiflorum, provides a large organic loading by intercepting nutrients in run‐off and then decaying in the stream channel. Water quality and reaeration aspects of the stream were studied in order to explain the observed low DO levels. Measurements of the reaeration coefficient at 20°C, K2 20, using methyl chloride (CH3Cl) as a gas tracer, yielded values of 1.1–3.0 d?1 for the upper part of the study reach and 15.5–16.2 d?1 for the lower reach (overall average 12.5 ± 2.5 d?1). These were in agreement with values inferred from single‐station diurnal curve analysis, which also showed that respiration was dominant in the lower reach where photo‐synthetic activity was inhibited by shade. The relatively large reaeration coefficients ensure that parts of the stream do not become anoxic at night time. Better riparian management and reduced nutrient inputs are likely to improve stream water quality. 相似文献
65.
Uniaxial compression and tension tests of anthracite and loading rate dependence of peak strength 总被引:2,自引:0,他引:2
The mechanical characteristics of coal under uniaxial compressive stress and uniaxial tensile stress are key factors in investigations of the stability of galleries and coal faces, and are vital considerations for the efficient design of coalmines, disaster prevention, and environmental preservation. These mechanical characteristics have long been a topic of research, but remain insufficiently understood. In this study we performed uniaxial compression tests and uniaxial tension tests on coal, with particular attention to two concerns. The first was to measure the loading rate dependence of the peak strength of coal. Coal shows high sample-to-sample scatter in strength; test methods that are successful in comparatively homogeneous rock types cannot be used for coal. We therefore used an alternative test method that was recently developed by the authors. Anthracite samples were subjected to alternating slow and fast strain rates. Measured variations in stress during this process were used to estimate the loading rate dependence of peak strength. The second objective was to obtain complete stress–strain curves for coal under uniaxial tensile stress. It is difficult to hold samples secure during a tensile test; consequently, such curves have yet to be obtained. This study presents a successful application of the authors' method to the analysis of coal samples, yielding a complete stress–strain curve under tensile stress. The two methods presented here hold promise for application not only to anthracite but also to a wide variety of coals. It is possible to derive the values of the constants used in constitutive equations from the obtained experimental results. Once these equations are determined, they can be incorporated into finite-element software to investigate various time-dependent behaviors of coal and aid in the efficient design of coalmines and the prevention of subsidence and mine disasters. 相似文献
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67.
结合安徽省高速公路建设工程实例,介绍瞬态瑞雷面波勘探技术在公路工程地质勘察中的应用,解决沿线高边坡、深路堑、桥梁、隧道进出口的岩土分层,给出基岩风化分带等工程地质问题,省时、省力,取得了良好的经济效益和环境效益. 相似文献
68.
69.
Several studies have shown that the dominant streamflow generation mechanism in a river basin can leave distinct geomorphological signatures in basin topography. In particular, it has been suggested previously that basins generated by groundwater discharge tend to have a larger hypsometric integral than surface runoff basins because fluvial erosion is more focused in the valleys where groundwater discharge tends to occur. In this analysis, we aim to clarify this relationship by developing an alternative method to quantify the effects of streamflow generation mechanisms on basin hypsometry and by using a numerical model that can generate streamflow by different processes to evaluate the sensitivity of the results to the hydrological and geomorphological properties of the basin. The model results suggest that the hypsometric characteristics that are usually associated with groundwater discharge basins, such as a larger hypsometric integral, occur primarily when drainage networks are still advancing in the watershed. During later stages of development, an additional factor such as lithological controls or a distinct geomorphological process would be needed to preserve these features. The model results also show that the hypsometric effects are stronger when the parameters of the fluvial erosion process promote the influence of small discharge rates. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
70.
太湖流域南区湿地磷状况及其滞留能力 总被引:1,自引:0,他引:1
选取太湖流域南区29个典型湿地采样点进行土-水磷素状况调查,并采集杭州西湖茅家埠、湖州德清下渚湖、湖州长兴包漾河等泥样进行静态柱和稳流水槽模拟实验,研究区域湿地底泥含TP 0.169-1.200g/kg,Olsen-P 7.08-67.08mg/kg,最大吸附量为269.5-824.5mg/kg,NaOH+EDTA-P占底泥TP的52.O%±11.6%,且伴随其积累会提高Olsen-P含量,相应上覆水含TP 0.036-0.944mg/L,总颗粒态磷占TP含量的70.9%±13.2%,DRP相对较低,静态柱实验中的DRP初始阶段缓慢下降,之后快速下降并维持在稳定水平,稳流水槽实验的DRP动态表现出准U型曲线特征,经验证,底泥的磷素吸附能力在Langmuir吸附实验及室内模拟实验中表现一致. 相似文献