有理三角Bézier曲线曲面光滑融合的构造

为了使自由曲线曲面在较为简单的条件下能够达到相对高阶的光滑拼接,并在不改变控制顶点的情况下自由调整曲线曲面的形状,构造了含多个形状参数的有理三角函数.基于该组基函数,定义了含多个形状参数的有理三角曲线曲面,并讨论了曲线曲面的光滑拼接条件.根据拼接条件,分别定义了由含多个形状参数的有理三角曲线曲面构成的分段组合曲线、分片组合曲面.这种新的曲线曲面能够自动保证组合曲线、曲面的连续性.数值实例的结果显示了该方法的有效性.     

鳞状BiOBr/Bi2WO6的合成及其吸附性能

采用一步水热法成功制备鳞状形貌的BiOBr/Bi₂WO₆复合物,通过X射线衍射（XRD）仪、扫描电子显微镜（SEM）、N2吸附/解吸附比表面测定仪（BET）、傅里叶变换红外（FT-IR）光谱等对复合物进行了表征。对比Bi₂WO₆与BiOBr的SEM照片,结合KBr的浓度实验,提出了BiOBr/Bi₂WO₆的鳞状形貌的形成机理。选取有机染料为吸附质,BiOBr/Bi₂WO₆为吸附剂进行了复合物吸附性能测试。结果表明,BiOBr/Bi₂WO₆对阳离子染料表现出优越的吸附性能,10 min对次甲基蓝（MB）的吸附率高达99%,优于常规的活性炭吸附剂。此外,BiOBr/Bi₂WO₆对有机染料的吸附行为符合准二级反应速率方程和Freundlich等温吸附模型。     

一种新型核壳型色谱固定相在高效液相色谱中的评价及应用

采用扫描电镜、透射电镜和氮气吸附法对制备的新型核壳型色谱固定相进行了表征,结果表明该固定相单分散性好、表面放射状孔道壳层结构均一、孔径分布窄。对该核壳材料的表面进行C18键合修饰,考察其基本色谱性能,色谱柱的理论塔板数超过150000块/m,色谱峰峰形对称,甲苯与乙苯的保留因子之比为1.45,亚甲基选择性优异。将该核壳材料应用于汽车尾气中醛酮类化合物的检测,在优化的色谱条件下,2,4-二硝基苯肼（DNPH）衍生的醛酮类化合物在15 min内获得了较好的分离效果。该核壳型C18色谱固定相具有分离速度快、选择性好、柱效高等特点,适于复杂样品的高效、快速分离分析。     

Thermal Quantum Discord in Pure Dzyaloshinskii-Moriya Model with Magnetic Field

We investigate the effects of the directions of Dzyaloshinskii-Moriya (DM) interaction vector and magnetic field on the quantum discord in the pure DM model. For different directions of DM vector, we find that there are different optimal parameter components of magnetic field. Moreover, we find that the optimal parameter components rules are the same for the Hamiltonian H₁ and H₂. According to the rules, for a certain axial DM vector, we can get the maximal quantum discord by adjusting the direction of the external magnetic field, which is feasible under the current experimental technology.     

Quantum Measurement of Two-Qubit System in Damping Noise Environment

It is known that the inevitable interaction of the entangled qubits with their environments may result in the degradation of quantum correlation.We study the decoherence of two remote qubits under general local single-and two-sided amplitude-damping channel(ADC).By using concurrence,quantum discord and Clauser-Horne-ShimonyHolt(CHSH)inequality,we find that the relation between the residual quantum correlations and the initial ones are different.Recently,Wang et al.[Int.J.Theor.Phys.54(2015)5]showed that there exist a set of partially entangled states that are more robust than maximally entangled states in terms of the residual quantum correlation measured by concurrence,fully entangled fraction and quantum discord,respectively.Here we find that both in single-and two-sided ADC,only the evolution of CHSH inequality with the initial parameter is proportional to that of the initial nonlocality.That means the initial state with maximally nonlocality will retain its role in the evolution.It implies that the evolution of nonlocality may reveal the characteristics of quantum state better.Furthermore,we discuss the evolutions of the three different quantum measurements with the initial parameter under generalized amplitude damping channel(GADC)and find that they are all proportional to that of the initial state.     

Influence of binding energies of electrons on nuclear mass predictions

Nuclear mass contains a wealth of nuclear structure information, and has been widely employed to extract the nuclear effective interactions. The known nuclear mass is usually extracted from the experimental atomic mass by subtracting the masses of electrons and adding the binding energy of electrons in the atom. However,the binding energies of electrons are sometimes neglected in extracting the known nuclear masses. The influence of binding energies of electrons on nuclear mass predictions are carefully investigated in this work. If the binding energies of electrons are directly subtracted from the theoretical mass predictions, the rms deviations of nuclear mass predictions with respect to the known data are increased by about 200 ke V for nuclei with Z, N 8. Furthermore, by using the Coulomb energies between protons to absorb the binding energies of electrons, their influence on the rms deviations is significantly reduced to only about 10 ke V for nuclei with Z, N 8. However, the binding energies of electrons are still important for the heavy nuclei, about 150 ke V for nuclei around Z = 100 and up to about 500 ke V for nuclei around Z = 120. Therefore, it is necessary to consider the binding energies of electrons to reliably predict the masses of heavy nuclei at an accuracy of hundreds of ke V.     

g-C3N4/SnS2异质结构:一类有潜力的光解水催化剂

采用第一性原理方法研究了层间耦合作用对g-C₃N₄/SnS₂异质结构的电子结构和吸光性质的影响.发现g-C₃N₄/SnS₂是一类典型的范德瓦异质结构,能有效吸收可见光,其价带顶和导带底与水的氧化还原势匹配,且由于电荷转移而导致的界面处极化场有利于光生载流子的分离.这些理论研究结果表明g-C₃N₄/SnS₂异质结构是一类非常有潜力的光解水催化材料.     

光学自由曲面面形检测技术

光学自由曲面因其表面自由度较大,可以针对性地提供或矫正不同的轴上或轴外像差,同时满足现代光学系统高性能、轻量化和微型化的要求,逐渐成为现代光学工程领域的热点。自由曲面的检测技术已经成为制约其应用的最重要因素,而目前精密光学自由曲面的检测手段仍然沿用非球面检测方法。本文回顾了近年来的自由曲面检测发展历程,对目前主流的非接触式检测方法(微透镜阵列法,结构光三维检测法,相干层析术,干涉检测法)进行了重点介绍;总结了非球面检测方法运用到自由曲面检测中的技术难点,同时结合这些技术难点,展望了自由曲面检测的未来发展新趋势,主要集中在非旋转对称像差的动态补偿、分区域像差的回程误差校准及子孔径拼接技术。     

基于相移干涉技术的晶体溶解及生长边界层实时监测

晶体在溶解及生长过程中边界层的信息直接影响晶体生长速度和物质输运过程,进而影响晶体质量和生长机制。本文利用相移干涉技术建立了晶体生长过程实时监测系统,对无机盐晶体溶解及生长过程中的边界层信息及物质输运过程进行了实时监测,获得了整个实验过程中的晶体生长速度。实验表明:在溶解过程中,边界层内浓度分布与晶体界面距离呈指数下降关系,边界层内浓度差与晶体溶解速度随时间呈指数减小关系;在结晶过程中,边界层内浓度分布规律与溶解过程相反;边界层内浓度差和晶体生长速度曲线则呈现出先上升再下降最后趋于稳定的规律,且在重力场和物质输运过程的共同作用下,晶体表面会产生浮力对流现象。     

污水处理厂及受纳水体样品的三维荧光光谱解析

采用三维荧光光谱表征了污水厂各处理单元及受纳水体上下游的样品,应用平行因子分析方法获得了样品中各主成分的激发发射光谱图及荧光强度得分矩阵。结果表明,类蛋白质和类富里酸物质是污水厂和受纳水体样品的主要荧光组分。污水厂进水样品的类蛋白质荧光较强,后续各处理单元样品的荧光强度显著下降。受纳水体上游样品的类蛋白质荧光较弱,经过城区各取样点的类蛋白质荧光显著增加,而污水厂排放口上游荧光强度则显著高于下游。类蛋白质荧光强度得分可与样品COD值建立相关曲线,污水厂与受纳水体样品的相关系数分别为0.930和0.913,类蛋白质荧光可以反映样品点的有机污染程度。该研究为污水处理厂的运行及其对受纳水体影响提供了新的思路和方法。