ICP—AES法测定铁矿中铝,钙,镁,锰,钴,铜,钠和钾

本文研究了ICP-AES法测定铁矿中铝,钙、镁、锰、钴、铜、钠和钾的方法。对仪器工作参数,共存元素的光谱干扰和基体效应干扰进行了探讨。采用向标准系列中加入铁基空白溶液建立工作曲线,试样经酸处理后即可直接测定。本方法获得了良好的回收率(95～103%)和变异系数(0.5～1.3%,n=11),同原子吸收法进行比对试验,结果一致。     

甘氨酸和丙氨酸二肽、三肽中N-H…O=C分子内氢键键能的理论研究

提出一种计算多肽中N-H…O=C分子内氢键键能的新方法.并将新方法应用于计算甘氨酸和丙氨酸二肽、三肽中N-H…O=C分子内氢键键能.利用密度泛函理论B3LYP/6-31G(d)方法优化几何构型和计算频率.对全部结构计算MP2/6-311 G(3df,2p)水平上的单点能量.结果表明:在甘氨酸二肽中氢键键能为-6.38 kcal/mol,在丙氨酸二肽中氢键键能为-7.09-、6.25 kcal/mol;在甘氨酸三肽中氢键键能为-5.62 kcal/mol,在丙氨酸三肽中氢键键能为-5.37,-5.74 kcal/mol.     

谐振子的传播子

本文以谐振子为例，说明路径积分的一种计算方法。     

Influence ofΛ Hyperons 1S0 Superfluidity on the Direct Urca Processes with Hyperons

In the framework of the relativistic mean field theory (RMFT), the relativistic energy losses of the direct Urca processes withhyperons (Y-DURCA) for reactionsΛ→p + e +\bar{\nu}_{e} andΞ^- →Λ + e +ν_e arestudied in neutron stars. We calculate the energy gap ofΛ hyperons and investigate the effects of the ¹S₀superfluidity (SF) ofΛ hyperons on the Y-DURCA processes. The calculated results are in line with the recent experimental data\Delta B_ΛΛ∽1.01±0.20^+0.18_-0.11 MeV.The results indicate that the ¹S₀ SF ofΛ hyperons exists in most density ranges of happening the two reactions. The
theoretical cooling curves are in agreement with observation data.     

Validation of fuzzy logic method for automated mass spectral classification for mineral imaging

Imaging mass spectrometry requires the acquisition and interpretation of hundreds to thousands of individual spectra in order to map the mineral phases within heterogeneous geomatrices. A fuzzy logic inference engine (FLIE) was developed to automate data interpretation. To evaluate the strengths and limitations of FLIE, the chemical images obtained using FLIE were compared with those developed using two chemometric methods: principle component analysis (PCA) and cluster analysis (K-Means). Two heterogeneous geomatrices, a low-grade chalcopyrite ore and basalt, were imaged using a laser-desorption Fourier transform mass spectrometer. Similar mineral distribution patterns in the chalcopyrite ore sample were obtained by the three data analysis methods with most of the differences occurring at the interfaces between mineral phases. PCA missed one minor mineral phase in the chalcopyrite ore sample and did not clearly differentiate among the mineral classes of the basalt. K-Means cluster analysis differentiated among the various mineral phases in both samples, but improperly grouped some spectra in the chalcopyrite sample that only contained unanticipated high mass peaks. Unlike the chemometric methods, FLIE was able to classify spectra as unknowns for those spectra that fell below the confidence level threshold. A nearest neighbor approach, included in FLIE, was used to classify the unknowns to form a visually complete image; however, the unknowns identified by FLIE can be informative because they highlight potential problems or overlooked results. In conclusion, this study validated the fuzzy logic-based approach used in our laboratory and reveald some limitations in the three techniques that were evaluated.     

CoNiZ系列合金的结构和马氏体相变性质

利用X射线衍射研究了CoNiZ(Z=Si,Sb,Sn,Ga等)合金在不同热处理条件下的相组成.当Z元素为Sn,Sb时,材料是完全的B2结构;但Z为Si时,材料变成面心立方的γ相.形成B2还是γ相由电子浓度和原子尺寸效应两种因素共同决定.而CoNiGa的研究结果表明,在合金中除了形成B2结构的同时还容易形成γ相,常表现出两相共存的特性.对材料进行不同方式的热处理可以使合金中两相的含量有所消长,γ相含量的多少对CoNiGa合金的马氏体相变有很大的影响.分析指出,两相共存及其所带来的物性变化是CoNiGa铁磁性形状记忆合金非常有利用价值的物理性质.     

GPON体系结构研究

千兆比特无源光网络(GPON)是一种面向下一代网络(NGN)的接入技术,它具有速率高、传输距离长、效率高和可伸缩性强等关键优势.同时,GPON支持引入更高带宽的以太网新业务,并能低成本提供传统的语音服务.介绍了GPON的标准化进展,分析了GPON的系统结构和协议参考模型,并给出了传输汇聚层的分层结构.     

Analysis on surface charging of insulator prior to flashover in vacuum

Prior to the flashover across an insulator in vacuum, the insulator surface is usually charged. It is of great importance to investigate the charging phenomena for better understanding the flashover characteristics. It is considered that there are two kinds of mechanisms closely related to the surface charging of insulator i.e., the secondary electron emission occurred over an insulator, and while employing a perfect electrode contact ahead of electron emission into vacuum, the charge injection and accumulation occurred inside the surface layer of an insulator. Based on the rigorous analysis of the kinetic processes of both primary and secondary electrons, the related surface charges were theoretically deduced. Involving the detrapping of charges trapped and the recombination of charges injected, the charging process due to charge injection and accumulation was analyzed. Some formulas were given to express the density of surface charges.     

二氢黄酮类化合物的核磁共振碳谱模拟研究

采用表征分子内部化学微环境的结构描述子原子电负性作用矢量(Atomic Electronegativity Interaction Vector, AEIV)对255个共振碳原子进行了结构表征,应用多元线性回归技术建立了结构描述子AEIV与这些碳原子的¹³C NMR化学位移的定量相关模型.该定量结构谱图关系(定量构谱关系/QSSR)模型的复相关系数达到R_MM=0.915,标准偏差为SD_MM=14.879. 采用留一法交互检验的结果为R_CV=0.909,SD_CV=15.324. 结果表明,模型具有良好的估计力和稳定性.     

Pose estimation for UAV aerial refueling with serious turbulences based on extended Kalman filter

In recent years, many pose estimation algorithms were developed, and have been successfully applied to solve unmanned aerial vehicle (UAV) aerial refueling pose estimation problems. This paper mainly focuses on solving this problem under serious turbulences circumstance. The extended Kalman filter is a set of mathematical equations to estimate the state of a process, which is able to support estimations of past, present, and even future states. In reference to previous papers and some simulations, we build up the noise models of refueling boom and atmospheric turbulence. Then, an extend Kalman filter is adopted to solve the pose estimation problem in UAV aerial refueling with serious turbulences. The experimental results demonstrate the feasibility and effectiveness of our proposed approach.