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1.
广州轨道交通三号线高速行驶条件下对安全限界的影响研究 总被引:3,自引:2,他引:1
给出了轨道交通车辆横向偏移量的计算方法 ,并应用列车 -线路动力耦合模型 ,分析了广州地铁三号线的安全限界变化问题。确定了当前按 80km/h行车速度设计的建筑限界能满足 13 0km/h行车速度的要求 ,限界尺寸不需改动可保证列车运行安全平稳 相似文献
2.
Dong Cao Ziyu Rao Fanglan Geng Hongyun Niu Yali Shi Yaqi Cai Yuehui Kang 《环境科学学报(英文版)》2020,32(11):67-74
Molecular level characterization of dissolved organic sulfur (DOS) by electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR MS) is necessary for further understanding of the role of DOS in the environment. Here, ESI spray solvent, a key parameter for ion production during ESI process, was investigated for its effect on the molecular characterization of DOS by ESI-FTICR MS. 100% MeOH as spray solvent was found for the first time to remarkably enhance the ionization efficiency of the majority of CHOS-molecules in NOM, which facilitated a total of 1473 CHOS-molecular formulas with one sulfur atom to be detected. The number of CHOS-molecular formulas obtained using 100%MeOH as spray solvent increased notably over 740 in comparison with those using 50% MeOH aqueous solution (731) or 50% ACN aqueous solution (653). Moreover, due to the enhancement of ionization efficiency of DOS during ESI processes, the tandem mass spectra of the NOM CHOS-molecules could be easily obtained using 100% MeOH as spray solvent, which were hardly obtained using 50% MeOH aqueous solution as spray solvent. The results of the tandem mass spectra suggested the first discovery of organosulfates or sulfonic acids in Suwannee River NOM sample. A simple method based on 100% MeOH as ESI spray solvent for advanced molecular characterization of DOS by ESI-FTICR MS was proposed and applied, and the results revealed more molecular information of DOS in sea DOM samples. 相似文献
3.
采用火焰原子吸收分光光度法测定鱼内脏及河流底泥中的铜。鱼内脏经组织捣碎机捣成匀浆后,加硝酸消解;底泥则经氢氟酸和高氯酸消化。该方法具有灵敏度高,精密度和回收率较好等特点。 相似文献
4.
We propose a modelling framework for the design of a Pigouvian effluent tax, in an environmental management problem implicating
several economic agents located in a river basin. The proposed charging system allows for the agents' geographical position
relative to the river's sections, at which environmental standards are to be enforced, and takes into account the possible
different market structures within which the agents are operating. In particular, we consider industrial agents competing
on an oligopolistic market, and a set of farmers acting as price takers on a large market. A regional authority's goal is
to induce agents to some sort of cooperation which would result in the satisfaction of the common environmental constraints.
The economic process on one side, and the pollution transport and accumulation on the other, constitute two dynamic processes
in two different time scales. As the economic process is much slower than the other process we can neglect the latter's transients
and concentrate on the time invariant steady state solutions to the transportation equation. The model thus constructed has
some noncooperative game and optimal control problem's features with space being the ‘running’ variable.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
5.
6.
石墨炉原子吸收法直接测定水中钼 总被引:1,自引:0,他引:1
用石墨炉原子吸收法测定水中钼.用不带平台的热涂层石墨管,将灰化温度提高到1850℃,原子化温度定为2380℃,取得较好效果.对6个样品测定,相对标准差<10%,加标回收率在96.6~101%之间,精密度和准确度较好. 相似文献
7.
目前GB/T164 88-1996以红外分光光度法这测定石油类的有一种方法。该法用四氯代碳作莘取剂 ,四氯化碳用量大。四氯化碳是一种有毒、挥发性较强的有机溶剂。在监测该项目时 ,绘制标准曲线所用的标准储备液的配制相当复杂且形成的系统误差比较大 ,为减少误差并准确地绘制标准曲线 ,本文采取了简化配制步骤的方法来绘制曲线 ,并达到了与JDS -10 0型红外分光测油仪使用说明书中提供的方法一致的效果。 相似文献
8.
We report a gas chromatographic-mass spectrometric method which allows the very long chain fatty acids content of trophoblastic tissue to be directly measured in samples collected by biopsy between 8 and 11 weeks of gestation. This method has been successfully applied to the detection of fetal Zellweger syndrome in two pregnant women who had previously delivered affected infants. In one of them, increased concentrations of C26:0 (0.254 versus 0.108±0.035 μ/mg proteins) and C24:0 (1.32 versus 0.815±0.325 μ/mg proteins) in trophoblast indicated that the fetus had Zellweger syndrome, a diagnosis confirmed by pathological findings after abortion. In the second case, the pregnancy was allowed to proceed, on the basis of normal concentrations of very long chain fatty acids in trophoblastic tissue, and its outcome was actually a healthy newborn. 相似文献
9.
氢化物发生一原子荧光光谱法测定气田废水中的痕量砷 总被引:2,自引:0,他引:2
采用氢化物发生-原子荧光光谱法测气田废水中的痕量砷。方法有取样量少,操作简单、灵敏度高、准确度高、重现性好等优点。砷的测定线性范围为1~200ng/mL,方法的检出限为0.0453ng/mL,相对标准偏差小于等于1.6%,加标回收率在96.0%~97.7%范围内。测定密码标样与气田废水中的痕量砷,获得了满意的结果。 相似文献
10.