共查询到20条相似文献,搜索用时 984 毫秒
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通过改善镜面冷却系统及光学探测装置扩大中温传递标准;通过在相对高露点温度下,使水和空气分离的冷凝回复系统,设计建立了新型高温传递标准,并做了误差分析。 相似文献
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提出了 2种计算二元理想物系的泡点和露点的简捷方法 ,通过实例说明计算过程 ,结果表明该方法收敛迅速 ,过程简单。 相似文献
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WS-Ⅰ型微量水份测定仪的研制 总被引:1,自引:0,他引:1
测定气体中痕量水份有露点仪、电解水份仪、压电水份仪和氧化铝水份仪等,各有优缺点;就灵敏度、连续性和操作繁简来说,以氧化铝水份仪为佳。1941年Kaller首先发表了氧化铝作介质的电容电阻湿度计。Cutting和Jason为现代氧化铝湿度计奠定了理论和实践方面的基础。美国Pana公司和爱尔兰Shaw公司已生产多种型号的商品仪器。而国内,未见有报导。WS—I型微量水份仪即根据氧化铝电容、电阻原理而设计並研制的仪器。可连续测定氢、氮、氩、空气等洁净气体中的水份,测量范围为-90℃~-20℃露点(相当于0.1~1000ppmv);测量准确度为±3℃露点;测量重复性为±1℃露点。 相似文献
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研究标准测量方法规定的测量范围和精密度在冶金分析仪器计量性能评价中的应用,包括常规的计量技术项目如检出限、重复性、稳定性、示值误差等,探讨了这些计量技术项目与测量方法重复性(r)、再现性(R)的关系。方法测定下限至少为仪器检出限的3~4倍,标准物质10次重复测量值的标准偏差限值为0.5r,标准物质10次再现性条件下测量值的限值为0.5R,示值误差的确定可参照临界极差CD_(0.95)。当仪器无计量技术规范或现有规范规定的参数无法评价仪器计量性能时均可以参照标准测量方法。 相似文献
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推导了络合返滴定曲线方程 ,绘制了络合返滴定曲线和计算了pN突跃。并利用双曲正弦函数的性质 ,提出了内含最大敏锐指数的络合返滴定误差计算公式 ,从而获得了计算络合返滴定pN突跃范围的公式。 相似文献
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《International journal of quantum chemistry》2018,118(12)
The problem of the stability of a confined atom when it is extracted from the confining cavity has been investigated, modeled by a spherical hard wall potential. The ionization probability when the atom is released from confinement has been obtained. The dependence of the ionization probability on the confinement radius and on the quantum numbers of the initial confined state has been studied. The probability density function of the ionization energy of the ejected electron has been obtained for the different cases considered. The oscillatory structure of this distribution function, with a principal maximum located in the neighborhood of the energy of the initial state and minima very close to zero has been elucidated. The sudden approximation has been applied and the analytic continuation method has been used to calculate the different stationary states. 相似文献
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Aleksandra F. Prokhorova Elena N. Shapovalova Aleksei V. Shpak Sergei M. Staroverov Oleg A. Shpigun 《Journal of chromatography. A》2009,1216(17):3674-3677
The evaluation of a macrocyclic glycopeptide antibiotic, eremomycin, as a chiral selector in capillary electrophoresis (CE) has been performed. The stability of eremomycin in solution and capillary electrolyte, as well as its optical and electrophoretic properties have been discussed. The effect of experimental parameters influencing the enantioseparation of several profens has been studied. Excellent enantioseparation of profens has been achieved and migration order has been validated. Comparison of enantioseparations of profens in CE by using eremomycin-mediated electrolytes and in HPLC with eremomycin immobilized on silica has revealed similar trends for both methods. 相似文献
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Three-dimensional shape of polyethylene single crystals grown from the melt has been studied. Two distinct types of lateral habit have been obtained: lenticular shape (type A) and truncated lozenge (type B) in the range of regime I and II. Electron microscopy has revealed chair-like shape of type B crystal and reconfirmed the planar shape of type A crystal. In the type B crystal, spiral growth has occurred frequently in the {110} sectors and the sense of the handedness of spiral terraces has been maintained. It has been, suggested that the frequens occurrence of spiral growth is responsible for a morphological change (axialite-spherulite) accompanying the regime I–II transition. The origin of the chair-like crystals has been discussed and, a possible mechanism has been suggested for the formation of spiral terraces; the mechanism is based on a distortion caused by the three-dimensional shape of chair-like crystals. It has been found that the chair-like crystals are curved in the opposite way to S-shaped lamellae observed by Bassett and Hodge in banded spherulites. In fact, the present work has led to the recognition of further classes of crystal with curving cross-sections and of distinctions between them. In final analysis, a unifying thread has been identified between lateral habits, growth kinetics and three-dimensional shape of lamellae, in turn, leading to some rationalization of multilayer developments including twisting in banded spherulites, the latter based on existing suggestions in the literature. 相似文献
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用INDO系列方法对C60自由基负离子进行了几何构型优化,得到D2h对称性的构型,表明C60--确实发生了Jahn-Teller畸变,导致单键变短,双键变长,形成15种键,9种不等同碳原子,其额外负电荷主要分布在赤道附近。以此构型为基础,计算了C60--的电子光谱,与实验值吻合,在对光谱进行理论指认的同时讨论了光谱红移的原因。 相似文献
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研究了一种纳米蜡乳液的制备方法。通过测试证明该体系稳定,得到平均粒径为57.6nm大小的纳米蜡乳液,可代替各种行业中使用的普通蜡乳液,如皮革[1]、纺织[2]、造纸[3][4]等行业· 相似文献
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茂金属 乙烯的流变性与加工性 总被引:8,自引:0,他引:8
研究了丁烯-1共聚的茂金属聚乙烯(mPE)的流变性,发现茂金属聚乙烯的窄分子量分 布导致它在挤出加工剪切范围里熔体粘度高、对剪切敏感性差以及熔体从牛顿型转为非牛顿型所需的剪切速率、转变应力高,在挤出加工条件下流动性差,加工困难。对茂金属聚乙烯(mPE)进行改性制得MmPE,MmPE熔体对温度、剪切速率的敏感性提高,在加工温 度、加工剪切范围里的天观粘度降低,加工流动性得到了显著的改进,可在普通聚乙烯加工 相似文献
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聚苯胺/膨润土纳米复合材料的合成与表征 总被引:9,自引:0,他引:9
通过嵌入手段设计与合成同时具有某些无机和有机物双重性能的新型材料-无机/有机纳米复合材料,是科学家们关注的课题[1].Inoue等人[2]采用蒙脱土吸附苯胺单体然后电氧化的方法制备了聚苯胺/蒙脱土(Pan/Mont)复合材料,由于Mont片体的表面吸附了苯胺,所合成的为聚合物包覆的复合材料,这样在一定的程度上影响了材料的各向异性.本文采用离子交换,洗涤除去吸附在粘土颗粒表面的单体,成功地合成了非包覆的聚苯胺/膨润土壤(Ben)层状纳米复合材料,并用FTIR等方法对材料进行了表征.该材料兼有粘土的离子交换性能和聚苯胺的良好… 相似文献