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《Journal of Nuclear Science and Technology》2013,50(4):435-441
The pressure swing adsorption (PSA) method, operating rapid desorption, has become applied to medium-massive air-component separation. In this study, with the aim of applying the PSA method to a hydrogen isotope separation process, the multi-component adsorption characteristics of H2-D2 or H2-HD-D2 on a synthetic zeolite at the liquid nitrogen temperature 77.4 K are investigated by using a volumetric apparatus, where the system effects of thermal transpiration and diffusion are taken into account. The adsorption isotherms for pure H2 and D2 are shown in a wide pressure range between 10-2 and 105Pa. The isotherms are closely approximated by an error functional expression proposed here. The separation factors resulting in adsorption are measured in a wide range of amount adsorbed. The separation factors of D2/H2 are estimated in accordance with the ideal adsorbed solution theory using the adsorption isotherms for H2 and D2. The behavior of the estimated factors agrees with that of the experimental ones. The result suggests that values around 3 are expectable for the factors of D2/H2 at amounts adsorbed roughly between 0.01 and 1 mol/kg. 相似文献
53.
基于ASP技术的动态网站组件的研发及应用 总被引:1,自引:0,他引:1
作为一种典型的服务器端网页制作技术,利用ASP(Active Server Pages)可以创建动态交互的Web服务器应用程序。根据油田生产、科研和日常办公的应用需求,以面向对象的思想和ASP技术开发出3类25种动态网站组件。应用结果表明,基于ASP技术的网站组件有利于快速、高效地开发动态网站,增强网站的实用性,降低网站的管理和维护成本。 相似文献
54.
本文建立了模拟农田SPAC(Soil-Plant-Atmosphere Continuum)系统中土壤水分动态,蒸发蒸腾、CO2通量和光合作用的模型。模型包括土壤水流子模型,根系吸水子模型,蒸发蒸腾子模型,冠层阻力-光合作用-CO2通量子模型几个组成部分。土壤水流子模型采用土壤水流的连续方程来描述;根系吸水子模型采用了根据Feddes模型改进得到的模型;蒸发蒸腾子模型采用Shuttleworth-Wallace公式;采用叶片水平的气孔阻力-光合作用模型,并将其扩展到冠层尺度来确定冠层阻力、光合作用速度以及叶片气孔下腔的CO2浓度,并进而确定冠层的CO2通量。本模型的特点是尽可能采用简便的处理方法来描述SPAC系统中的水、热、CO2传输过程与光合作用过程,同时各个子模型又具有较强的机理性。 相似文献
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由于农业用地对环境要求相对较高,且需要大量的人力、物力进行管理,多数矿山企业在土地复垦时一般不将种植作物作为其土地用途,而是以管理工作及费用相对较少的林、草种植为主.林草种植在矿山复垦种植中占有相当重要的地位,着重探讨海州露天矿排土场牧草种植的技术途径. 相似文献
57.
Haimin Zhang Yun Wang Dan Wang Yibing Li Xiaolu Liu Porun Liu Huagui Yang Taicheng An Zhiyong Tang Huijun Zhao 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(16):3371-3378
In this work, we present a low cost and environmentally benign hydrothermal method using dried grass as the sole starting material without any synthetic chemicals to directly produce high quality nitrogen‐doped carbon nanodot/nanosheet aggregates (N‐CNAs), achieving a high yield of 25.2%. The fabricated N‐CNAs possess an N/C atomic ratio of 3.41%, consist of three typed of doped N at a ratio of 2.6 (pyridinic):1.7 (pyrrolic):1 (graphitic). The experimental results reveal that for oxygen reduction reaction (ORR), the performance of N‐CNAs, in terms of electrocatalytic activity, stability and resistance to crossover effects, is better or comparable to the commercial Pt/C electrocatalyst. The theoretical studies further indicate that the doped pyridinic‐N plays a key role for N‐CNAs' excellent four‐electron ORR electrocatalytic activity. 相似文献
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59.
I.C Madakadze K Stewart P.R Peterson B.E Coulman R Samson D.L Smith 《Biomass & bioenergy》1998,15(6):475-482
Switchgrass (Panicum virgatum L.) has been identified as a potential biomass crop in North America. A two-year study was conducted to characterize leaf area development and estimate radiation-use efficiency (RUE) of switchgrass in eastern Canada. Three cultivars, Cave-in-Rock (CIR), Pathfinder (PF) and Sunburst (SB) were grown in solid stands in a randomized complete block design. Dry matter (DM) yield, leaf area development and light interception were monitored bi-weekly throughout the growing season. Herbage subsamples were hand separated into leaf and sheath-stem fractions. Mean seasonal maximum leaf area indices (LAI) were 6.1, 5.3 and 5.1 for CIR, PF and SB, respectively. By early July of each season the canopies were intercepting about 90% of the incoming light. End of season DM yields were 12.2, 11.5 and 10.6 Mg ha−1 for CIR, PF and SB, respectively. The stem plus leaf sheaths constituted the major component of DM and its accumulation trend parallelled that of total DM. End of season stem-sheath components averaged 764, 714 and 691 of the total g kg−1 DM for CIR, PF and SB, respectively. Energy contents of the switchgrasses averaged 17.4 MJ g−1 DM and did not vary among cultivars or during the season. This translated into total energy yields ha−1 of 216 GJ for CIR, 197 for PF and 186 for SB. Radiation-use efficiencies computed using total incoming solar radiation, for the near linear growth phases, averaged 1.07 g DM MJ−1 for CIR, 0.90 for PF and 0.89 for SB. The respective values based on photosynthetically active radiation were 2.20, 2.00 and 1.96 g DM MJ−1. Changes in LAI, relationships between LAI and light interception and DM yield could all be described by predictive regression equations. These results indicate the potential of switchgrass as a biomass crop in short season areas. 相似文献
60.
环境因子对土壤水分蒸散的影响 总被引:3,自引:0,他引:3
在有作物生长的条件下,土壤散失到大气中的水分主要通过土壤表面蒸发和作物叶面蒸腾两种方式进行,二者之和称为土壤水分蒸散。由于作物冠层的遮荫作用,作物覆盖下土壤水分的蒸发强度与裸土情况下显然不同。本文建立了土壤水分蒸散率的计算公式,并对几个环境因子的影响进行了讨论。计算结果表明,冠层净辐射强度和空气饱和差对蒸散率影响较大,而气温和风速的影响相对较小。当冠层净辐射强度和空气饱和差增大时,蒸散率和日蒸散总量的增加均较为明显。另外,作物的叶面积指数对蒸散也有较大的影响,同时它对蒸发和蒸腾在蒸散中所占的比重影响很大,叶面积指数增大时,叶面蒸腾所占的份额增大,而蒸发所占的份额相应地减小。 相似文献