大学生化学课堂笔记行为特点的研究*

研究从笔记内容、笔记位置、笔记格式、笔记详细程度和笔记编码程度等5个方面描述大学生的化学课堂笔记行为,分析了大学生化学课堂笔记行为的特点,比较了不同学业水平大学生的化学课堂笔记行为差异,为改进大学生化学课堂笔记行为提出相应的教学建议。     

四川得荣地区徐麦超基性岩体地球化学特征及成矿潜力

对四川得荣地区徐麦超基性岩体的主量元素进行了分析。结果表明,该岩体中S iO2含量为35.27%~42.25%,MgO含量34.85%~38.16%,ALK为0.019 3%~0.031 9%,m/f比值为7.06~12.78;微量元素分析成果显示其富相容元素Cr、Co、N i,几乎亏损所有的不相容元素;稀土元素球粒陨石标准化曲线显示轻稀土富集而重稀土亏损;δEu值介于0.82~12.61之间,具明显正铕异常特征。结合该岩体的地质特征,认为徐麦超基性岩体属于镁质超基性岩,含矿性较好,其成矿远景意义相对较大。     

Optical and Structural Properties of Mn-Doped GaN Grown by Metal Organic Chemical Vapour Deposition

Mn-doped GaN epitaxial films were grown by metal organic chemical vapour deposition （MOCVD）. Microstructural properties of films are investigated using Raman scattering. It is found that with increasing Mn-dopants levels, longitudinal optical phonon mode A1 （LO） of films is broadened and shifted towards lower frequency. This phenomenon possibly derives from the difference in bonding strength between Ga-N pairs and Mn-N pairs in host lattice. In addition, optical properties of films are investigated using cathodoluminescence and absorption spectroscopy. Mn-related both emission band around 3.0eV and absorption bands around 1.5 and 2.95eV are observed. By studies on structural and optical properties of Mn-doped GaN, we find that Mn ions substitute for Ga sites in host lattice. However, carrier-mediated ferromagnetic exchange seems unlikely due to deep levels of Mn acceptors.     

Global optimality condition and fixed point continuation algorithm for non-Lipschitz ?_p regularized matrix minimization

Regularized minimization problems with nonconvex, nonsmooth, even non-Lipschitz penalty functions have attracted much attention in recent years, owing to their wide applications in statistics, control,system identification and machine learning. In this paper, the non-Lipschitz ?_p(0 p 1) regularized matrix minimization problem is studied. A global necessary optimality condition for this non-Lipschitz optimization problem is firstly obtained, specifically, the global optimal solutions for the problem are fixed points of the so-called p-thresholding operator which is matrix-valued and set-valued. Then a fixed point iterative scheme for the non-Lipschitz model is proposed, and the convergence analysis is also addressed in detail. Moreover,some acceleration techniques are adopted to improve the performance of this algorithm. The effectiveness of the proposed p-thresholding fixed point continuation(p-FPC) algorithm is demonstrated by numerical experiments on randomly generated and real matrix completion problems.     

以函数为参量的间歇发酵非线性动力系统及其辨识

建立以连续分段线性函数为参量的间歇发酵非线性动力系统,证明该动力系统的主要性质及解的存在性.以实验数据拟合得到的光滑曲线为依据,提出了连续分段线性函数为优化变量的辨识模型,论述可辨识性.依状态变量与辨识函数的相关性,构造求解辨识模型的优化算法,并给出优化算法的收敛性分析及数值结果.     

Global error bounds for the extended vertical LCP

A new necessary and sufficient condition for the row -property is given. By using this new condition and a special row rearrangement, we provide two global error bounds for the extended vertical linear complementarity problem under the row -property, which extend the error bounds given in Chen and Xiang (Math. Program. 106:513–525, 2006) and Mathias and Pang (Linear Algebra Appl. 132:123–136, 1990) for the P-matrix linear complementarity problem, respectively. We show that one of the new error bounds is sharper than the other, and it can be computed easily for some special class of the row -property block matrix. Numerical examples are given to illustrate the error bounds. The work was in part supported by a Grant-in-Aid from Japan Society for the Promotion of Science, and the National Natural Science Foundation of China (10671010).     

Clarke Generalized Jacobian of the Projection onto Symmetric Cones

In this paper, we give an exact expression for Clarke generalized Jacobian of the projection onto symmetric cones, which generalizes and unifies the existing related results on second-order cones and the cones of symmetric positive semi-definite matrices over the reals. Our characterization of the Clarke generalized Jacobian exposes a connection to rank-one matrices.      

A CLASS OF TRUST REGION METHODS FOR LINEAR INEQUALITY CONSTRAINED OPTIMIZATION AND ITS THEORY ANALYSIS：Ⅰ. ALGORITHM AND GLOBAL CONVERGENCE

A class of trust region methods tor solving linear inequality constrained problems is propo6ed in this paper. It is shown that the algorithm is of global convergence. The algorithm uses a version of the two-slded projection and the strategy of the unconstrained trust region methods. It keeps the good convergence properties of the unconstrained case and has the merits of the projection method. In some sense, our algorithm can be regarded as an extension and improvement of the projected type algorithm.     

Quantum Secure Direct Communication with Four-Particle Genuine Entangled State and Dense Coding

A quantum secure direct communication scheme using dense coding is proposed. At first, the sender （Alice） prepares four-particle genuine entangled states and shares them with the receiver （Bob） by sending two particles in each entangled state to him. Secondly, Alice encodes secret information by performing the unitary transformations on her particles and transmits them to Bob. Finally, Bob performs the joint measurements on his particles to decode the secret information. The two-step security test guarantees the security of communication.     

波长色散X射线荧光光谱仪的内部校准

根据波长色散X射线荧光光谱仪检定规程制定了内部校准作业指导书,对PANalytical Axios 4.0型X射线荧光光谱仪的外观、精密度（RSD）、稳定性（RR）、探测器分辨率（流气正比计数器、闪烁计数器、封Xe正比计数器）和仪器的计数线性进行了性能测试和内部校准.