无重复因析试验中散度效应的截断估计及其性质

在无重复因析试验的散度效应分析中,常常对残差平方取对数来建立散度效应模型,但是当拟合位置模型后得到的残差绝对值很小或者近似为0时,直接对残差平方取对数建立散度效应模型显然是不合适的.基于此,文章提出了一种新的散度效应估计方法--截断估计,并且考虑了该估计的渐近性质,给出了它的渐近期望和渐近方差.     

运河煤矿13_下04综放面采空区自燃危险区域划分

针对运河煤矿煤层的自然发火倾向,采用真空泵抽气法和埋设热电阻测定法对采空区气体成分进行测定,掌握了氧气浓度随工作面推进的变化规律.借助测定的氧浓度反推出了采空区漏风强度变化规律.根据获得的氧气浓度、漏风强度变化曲线,利用"三带"划分的极限值法对运河煤矿采空区进行了"三带"划分,并根据工作面实际推进速度确定出自然发火区域为采空区进风侧大于78m的范围.     

土体性质对Cl-迁移过程影响的试验研究

通过室内土柱试验模拟污染物迁移,分析了平均粒径、孔隙比、不均匀系数等土体性质对迁移规律的影响。试验结果表明:平均孔隙流速随着土样平均粒径的增大而增大,初始穿透时间随着土样孔隙比变大而缩短;弥散系数随着平均粒径、孔隙比的增大而增大。通过试验数据拟合得到符合试验土样的弥散系数经验公式。试验结果为污染土体及地下水体的防治工作提供依据。     

二维粘弹介质五点八阶超紧致有限差分声波方程数值模拟

本文首次将五点八阶超紧致有限差分格式(CCD8)用于粘弹介质声波方程的数值模拟中。此文根据泰勒级数展开粘滞声波方程,建立了位移场时间二阶离散格式,将CCD8用于对位移场空间导数的求取。然后,对CCD8格式进行稳定性研究,频散的压制效果对比分析,及截断误差对比。将CCD8格式运用于均匀介质模型以及水平层状介质模型中进行数值模拟,最后运用于对Marmousi模型的数值模拟中。研究结果表明：(1)CCD8与普通八阶紧致差分相比,具有更小的截断误差、更高的模拟精度以及低数值频散的优势;(2)CCD8具有较高稳定性;(3)采用完全匹配层(PML)对人工边界进行处理后对均匀介质、含有层状介质以及Marmousi模型进行粘弹声波方程的数值模拟,发现模拟效果不错,从而验证了方法的实用性和有效。     

Dispersion relation and energy allotment of eigenmode of layer-by-layer photonic crystal

The photonic crystal of layer-by-layer(LBL) structure is discussed in this paper.The structure of LBL photonic crystal is body-centered tetragonal (b.c.t)rather than face-centered tetragonal(f.c.t.)For the LBL photonic crystal of f.e.c or b.c.c lattice,to obtain the fulll information on its Brillouin zone,the calculation of three restricted volumes is needed and our calculation result agrees well with the experiment.The allotments of optical fields of eigenmodes in a dielectric material are also calculated.In the dielectric material,for the eigenmode at the bottom of the forbidden gap,electric field takes a larger fraction of the whole energy than magnetic field,while for the eigenmode at the top of the forbidden gap,allotment of energy is just the other way round.     

误差项为RDM的广义线性模型的诊断

该文将Cook和Weisberg提出的线性模型残差分析和影响分析方法用于误差项为RDM的广义线性模型,证明了均值漂移模型与数据删除模型的等价性,求出常用诊断统计量的一阶表示式。     

煤自燃性测试技术及数值分析

利用装煤量850kg的XK型煤自然发火实验台,真实地模拟了煤的自燃过程,根据实验测定的温度场和气体浓度场变化,结合流体力学和传热学理论,推算出不同温度时煤氧复合的耗氧速度,放热强度,为煤自燃性的定量分析及自然发火预测提供理论依据,并根据煤自身的氧化放热性能及其所处的蓄热环境,应用热平衡法推导出煤自燃极限参数的计算方法,为煤自燃预测及防治提供了量化的理论判据。     

单道流路中样品分散与管路体积的关系

论文经推导和实验证实,单道流路系统中样品分散与管路体积的关系可表示为线性关系,对应于流出曲线极大值的流体元一经分散,分散系数的增量与所通过的管路体积的增量成正比,在一合适的范围内,一细反应管可用另一管体积相同而管径不同的细反应管替换,若其他实验条件不变,样品分散系数保持不变。     

微波辐照合成单分散、大粒径的聚苯乙烯微球

以聚乙烯吡咯林酮为稳定剂,十六醇为助稳定剂,４,４’－偶氮二异（４－氰基）戊酸或偶氮二异丁腈为引发剂,无水乙醇为分散介质,在微波辐射合成了聚苯乙烯大粒径,在透射电镜下观察粒子形状和大小,制备出直径１－２．５μｍ的单分散聚苯乙烯微球,并讨论了引发剂浓度对所得聚合物颗粒直径和直径分布的影响。     

Surface interactions of MoO3/ α-Fe2O3 system

α-Fe₂O₃ -supported molybdena catalysts have been prepared by heating a mixture of MoO₃ and α-Fe₂O₃. XRD, XPS, LRS, TG-DTA and Mössbauer spectroscopy were used to characterize the interactions between MoO₃ and α-Fe₂O₃. The dispersion capacity of MoO₃ on the surface of α-Fe₂O₃ determined by XRD and XPS was 0.8 mmol/100m² α-Fe₂O₃ in the samples calcined at 420 . For the sample with low MoO₃ loading, LRS and FT-IR results showed that Mo⁶⁺ ions were located in the tetrahedral vacant sites on the surface of α-Fe₂O₃, signed as Mo- . The amount of Mo-II species, formed by Mo6+ ions incorporated into the octahedral vacant sites, increased with the MoO₃ loading. Based on the assumption that the (001) plane of α-Fe₂O₃ is preferentially exposed, almost all the Mo⁶⁺ ions of the dispersed molybdena species existed at the surface octahedral sites for the sample with MoO₃ loading close or beyond the dispersion capacity, and formed the Mo-II species. In this case, the capping O^2- ions linking with the incorporated Mo⁶⁺ ions formed a surface epitaxial structure, which was in good agreement with the results predicted by the incorporation model proposed previously. XRD and Mössbauer spectroscopy of the MoO₃ α-Fe₂O₃ samples calcined at different temperatures showed that the calcination temperature could strongly influence the interaction extent: ( i) at 420 , MoO₃ dispersed on the surface of α-Fe₂O₃ and formed surface Mo species; (ii ) at 500 , MoO₃ reacted with the bulk of α-Fe₂O₃ and formed Fe₂(MoO₄)₃ compound.