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《Atmospheric Environment. Part A. General Topics》1992,26(5):807-812
A quantitative analysis of the infrared spectrum of gaseous methanesulphonic acid (MSA, CH3SO3H) has been performed in the region of 4100-700 cm−1 using in situ Fourier Transform Infrared Spectroscopy (FTIR). The influence of the temperature and the partial pressure of the diluent gas (N2) on the measured infrared absorption coefficients and the integrated band intensities was investigated. This study represents the first report of infrared absorption coefficients and integrated band intensities for gaseous MSA. 相似文献
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L. Sentilhes E. Verspyck D. Eurin V. Ickowicz S. Patrier J. Lechevallier L. Marpeau 《黑龙江环境通报》2004,24(3):198-201
Amniotic band syndrome or amniotic disruption complex is a well-known congenital limb abnormality, which occurs in 1 in 1200 to 1 in 15 000 live births. In cases of an isolated band constriction, it has been speculated that the bands lead to decreased blood flow in the constricted limb and subsequent natural amputation. Fetal surgery could be considered in these situations in order to release the constriction band in threatened limb amputation. We present a case of a tight constriction ring secondary to amniotic band syndrome with a favourable outcome, despite the failure of an attempted surgical procedure. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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藻类的光谱吸收特征及其混合藻吸收系数的分离 总被引:5,自引:3,他引:2
利用定量滤膜技术测定了实验室培养的聚球藻(Synechococcus 7942)、铜绿微囊藻(Microcystis aeruginosa)、斜生栅藻(Scenedesmusobliquus)、蛋白核小球藻(Chlorella pyrenoidosa)、直链硅藻的吸收光谱(Melosira granulate Var.angustissima),通过其标准化吸收谱,分析了同种藻不同生长时期的吸收谱特征,并比较分析了不同藻类的标准化吸收谱.结果表明,同一藻的标准化吸收光谱在不同生长时期基本恒定不变.色素组成及其比例的不同是引起藻类间吸收光谱变化的主要原因,同时也是大型浅水湖泊中浮游植物种群演替的原因之一.蓝藻光谱主要存在620nm左右的吸收峰,使得其在水体中较易获取生长所需的光能.直链硅藻在短波范围内稍强的吸收能力被非藻类颗粒物、黄质所弱化,而其在630nm的吸收峰较低,因而难以成为浅水湖泊中的优势种;绿藻在655nm处的吸收肩峰有利于其光能竞争.通过纯种藻的标准化吸收谱,较为成功地对混合藻的吸收谱进行了分离. 相似文献
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本文对呼和浩特市冬季大气污染情况,就采暖锅炉烟尘排放严重超标的成因进行调查分析,并丰现实条件下通过强人全方位管理、实现改善大气环境质量之目的,提出一些具体措施,具有一定的可操作性和适用性。 相似文献
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RelationshipbetweenoilfumemutagensinambientairandthedeteriorationofheatededibleoilsBaoZiping,HeJianqun,HouFuzhong(Instituteof... 相似文献
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采用间歇振荡法,研究了钢渣吸附模式、选择性以及等温吸附方程。结果表明,钢渣对阳离子的吸附容量远远大于对阴离子的吸附容量,其吸附模式属于离子交换;其对重金属离子具有一定的吸附选择性,其选择性能与离子的电性、电价、离子半径和水化热等因素有关;钢渣吸附Pb2+是单层吸附,符合Langmuir等温吸附方程。 相似文献
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《Journal of Cleaner Production》2006,14(1):80-86
The Dilemma of the Dead Sea is briefly addressed. The Dead Sea is a major source for the production of food grade Sodium Chloride (NaCl) through the use of traditional salt grinding, multiple washing stages and then evaporation. But there have been problems in producing industrial grade NaCl due to the high percentage of Ca+2 and Mg+2 ion concentrations. Pilot plant experiments were conducted to simulate a sodium chloride recovery from the Dead Sea brines. Viable engineering options were examined and tested. These options are classified either by adding certain chemicals such as the use of Sodium Stearate and Sodium Carbonate or implementing and modifying process conditions. The changes in operating conditions involve; reducing the particle size and changing both water type and contact time in the washing stages, adding a low 45 rpm agitator and finally investigating the appropriate water type scheme to be used in a double washing system. These changes have significant impact in enhancing NaCl recovery especially when brackish water is used. Also brine/brackish scheme is the best choice to be used in a double washing operation. 相似文献
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Cañaveras JC Cuezva S Sanchez-Moral S Lario J Laiz L Gonzalez JM Saiz-Jimenez C 《Die Naturwissenschaften》2006,93(1):27-32
In this study, we show that moonmilk subaerial speleothems in Altamira Cave (Spain) consist of a network of fiber calcite
crystals and active microbial structures. In Altamira moonmilks, the study of the typology and distribution of fiber crystals,
extracellular polymeric substances, and microorganisms allowed us to define the initial stages of fiber crystal formation
in recent samples as well as the variations in the microstructural arrangement in more evolved stages. Thus, we have been
able to show the existence of a relationship among the different types of fiber crystals and their origins. This allowed us
to outline a model that illustrates the different stages of formation of the moonmilk, developed on different substrata, concluding
that microbes influence physicochemical precipitation, resulting in a variety of fiber crystal morphologies and sizes. 相似文献
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Large diamond crystals up to 6 mm in average diameter may be grown at high pressures (55–60 kbar) and temperatures (1400–1500 °C) by causing diamond to dissolve in a molten catalyst metal (Fe, Ni, Co, etc.) in a hot region and deposit upon a seed crystal in a slightly cooler region. Several days are required to produce a high quality single crystal. The process can be controlled to produce different kinds of diamonds whose properties have been studied. 相似文献
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IdentificationandmechanismofformationofcertainmutageniccomponentsinthevolatilecondensatesfromoxidizedandheatededibleoilsBaoZi... 相似文献
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