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铀床氚残留量的测量  [PDF]
刘文科,龙兴贵,彭述明,王维笃,杨本福,曹小华,程贵钧
化学学报 , 2007,
Abstract: 分别采用直接测量法、同位素交换法和溶解法测量铀床中的氚残留量,并分析了这三种测量方法在本实验条件下的误差.直接测量法测量铀床的氚残留量的结果如下铀床的氚残留量为2.68%,即每克铀含(0.0308±0.0003)mmol氚气;当压力读数在1500~133332Pa之间时,基于理想气体状态方程的测量方法(简称PVT法)的标准差小于0.95%.同位素交换法测量铀床氚的结果如下加热充分解吸过的铀床经多次同位素交换后,其交换效率仅为2.84%,即不到3%(摩尔分数)的氚被氘气载带出来,其同位素交换法测量的标准差为7.35%.溶解法能够彻底地测量铀床中残留的氚,其溶解法测量的标准差为6.49%.
三相床甲醇合成过程:Ⅱ.C302催化剂甲醇反应本征动力学  [PDF]
丁百全,王存文
华东理工大学学报 , 2000,
Abstract: 研究了C302型铜基催化剂上由CO、CO2与H2合成CH3OH的本征反应动力学。为使本征动力学模型能应用于三相床甲醇合成过程,实验所用原料气中CO浓度较高,范围为yco=0.08~0.26,压力和温度均在合成甲醇工业操作的范围内。选用双速率的Langmuir-hinshelwood方程来描述系统的本征反应速率,该模型的计算值与实验结果相吻合。
三相床甲醇合成过程II.C302催化剂甲醇反应本征动力学  [PDF]
丁百全,王存文,秦惠芳,王弘轼,朱炳辰
华东理工大学学报 , 2000,
Abstract: 研究了C302型铜基催化剂上由CO、CO2与H2合成CH3OH的本征反应动力学。为使本征动力学模型能应用于三相床甲醇合成过程,实验所用原料气中CO浓度较高,范围为yCO=0.08~0.26,压力和温度均在合成甲醇工业操作的范围内。选用双速率的Langmuir-Hinshelwood方程来描述系统的本征反应速率,该模型的计算值与实验结果相吻合。
陕西丹凤三角地区花岗伟晶岩铀-稀有元素矿化特征及成矿作用分析  [PDF]
朱焕巧,李卫红,恵争卜,赵如意,王江波,龚奇福
西北地质 , 2015,
Abstract: 重点对北秦岭丹凤三角地带花岗伟晶岩的地质矿化特征及铀-稀有元素成矿作用进行了研究分析,认为花岗伟晶岩是在岩浆演化晚期,富含挥发分的残余岩浆进一步分异演化的结果,花岗伟晶岩主要侵位于加里东中晚期花岗岩体的内外接触带及秦岭岩群中,多沿背斜轴部和断裂、裂隙分布,多平行于区域构造线延伸方向.花岗伟晶岩的岩石类型有:黑云母伟晶岩、二云母伟晶岩、白云母伟晶岩、白云母钠长石伟晶岩、锂云母钠长石伟晶岩,是由交代分异作用引起的.花岗伟晶岩的成岩、成矿作用可划分为后岩浆、伟晶作用、气成作用和热水溶液4个阶段.花岗伟晶岩具明显的多元素矿化特征,富含U、Th、Nb、Ta、L等稀有金属和绿柱石、云母、钾长石等非金属矿产.
新型催化剂C302-2作用下的三相床甲醇合成过程Ⅲ.本征反应动力学  [PDF]
张淑华,李涛,王弘轼,朱子彬,朱炳辰
华东理工大学学报 , 2004,
Abstract: 在等温积分反应器中,压力2.5~5.6MPa,温度210~255℃,空速6000~20000h^-1的实验条件下,对西南化工研究院研制的新型低温低压甲醇合成催化剂C302—2的CO、CO2加氢合成甲醇的本征动力学进行了研究。用改进的单纯形法和改进的高斯-牛顿法相结合对所采用的Langmuir—Hinshelwood型动力学模型进行参数估值,得到本征动力学方程。残差分析和统计检验结果表明,得到的本征动力学模型是适定的,可良好地适合于反应条件。实验结果可以为采用细颗粒催化剂的三相淤浆床甲醇合成反应器设计提供本征动力学数据。
Ultraviolet structure in the lensed QSOs 0957+561  [PDF]
J. B. Hutchings
Physics , 2003, DOI: 10.1086/375464
Abstract: Imaging and spectra of the lensed QSO pair 0957+561 are presented and discussed. The data are principally those from the STIS NUV MAMA, and cover rest wavelengths from 850A to 1350A. The QSOs are both extended over about 1 arcsec, with morphology that matches with a small rotation, and includes one feature aligned with the VLBI radio jets. This is the first evidence of lensed structure in the host galaxy. The off-nuclear spectra arise from emission line gas and a young stellar population. The gas has velocity components with radial velocities at least 1000 km/s with respect to the QSO BLR, and may be related to the damped Ly alpha absorber in the nuclear spectra.
铀对外依存与铀供应保障的关系研究  [PDF]
崔娜
资源科学 , 2014,
Abstract: 理性认识铀对外依存,正确理解铀对外依存度与铀供应保障之间的关系是正确分析我国铀供应现状、完善铀供应体系的前提和基础。通过对铀对外依存度的概念、内涵、计算方法及世界主要核电国家/区域铀供应体系的分析得出:由于世界铀资源分布与核电发展的非均衡性,铀市场注定是全球性市场;铀对外依存度仅能反映铀供应安全的一个方面,铀供应的关键问题在于构建合理的铀供应保障体系,保证国外铀产品为我所用。为保障能源资源长远供应安全,我国有必要在一定程度上对外依存铀,同时加大国内铀矿勘探开发投入力度,全方位开展国际铀贸易,灵活采取多种方式促进海外铀资源勘探开发,积极发展天然铀循环加工服务,建立和扩充铀储备完善现有铀供应体系。
Velocity Dispersion of the Gravitational Lens 0957+561  [PDF]
John L. Tonry,Marijn Franx
Physics , 1998, DOI: 10.1086/307048
Abstract: 0957+561 is the first gravitational lens system to be discovered and first for which a time delay was measured. Because the system is unusually rich in observables such as image positions, fluxes, VLBI structure, and polarization it has been modelled quite extensively. However, since it resides in a cluster providing substantial convergence, the velocity dispersion of the lensing galaxy is an important component to models. We have measured this dispersion to be 288+/-9 kms (1-sigma), which implies a Hubble constant of 72+/-7 kms/Mpc (1-sigma) according to the preferred FGS model of Grogin and Narayan, and 70+/-7 kms/Mpc (1-sigma) using the SPLS model. The unknown velocity dispersion anisotropy of the central galaxy produces an additional uncertainty of perhaps 15% or more. We see no variation in dispersion with position to a radius of +/-3". In addition to a galaxy from the background cluster at z=0.5, our slit serendiptously picked up a galaxy at z = 0.448, and two galaxies which may be part of a background cluster at a redshift of z=0.91.
Hourly Variability in Q0957+561  [PDF]
Wesley N. Colley,Rudolph E. Schild
Physics , 1999, DOI: 10.1086/309305
Abstract: We have continued our effort to re-reduce archival Q0957+561 brightness monitoring data and present results for 1629 R-band images using the methods for galaxy subtraction and seeing correction reported previously. The new dataset comes from 4 observing runs, several nights apiece, with sampling of typically 5 minutes, which allows the first measurement of the structure function for variations in the R-band from timescales of hours to years. Comparison of our reductions to previous reductions of the same data, and to r-band photometry produced at Apache Point Observatory shows good overall agreement. Two of the data runs, separated by 417 days, permit a sharpened value for the time delay of 417.4 days, valid only if the time delay is close to the now-fashionable 417-day value; our data do not constrain a delay if it is more than three days from this 417-day estimate. Our present results show no unambiguous signature of the daily microlensing, though a suggestive feature is found in the data. Both time delay measurement and microlensing searches suffer from from the lack of sampling at half-day offsets, inevitable at a single observatory, hence the need for round-the-clock monitoring with participation by multiple observatories.
A Large Brightness Enhancement of the QSO 0957+561 A Component  [PDF]
A. Oscoz,D. Alcalde,M. Serra-Ricart,E. Mediavilla,J. A. Munoz
Physics , 2002, DOI: 10.1086/341968
Abstract: We report an increase of more than 0.2 mag in the optical brightness of the leading image (A) of the gravitational lens Q0957+561, detected during the 09/2000 -- 06/2001 monitoring campaign (2001 observing season). The brightening is similar to or even greater than the largest change ever detected during the 20 years of monitoring of this system. We discuss two different provisional explanations to this event: intrinsic source variability or microlensing (either short timescale microlensing or cessation of the historical microlensing). An exhaustive photometric monitoring of Q0957+561 is needed until summer of 2002 and during 2003 to discriminate between these possibilities.
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