土体的本构模型和超重力物理模拟

数值模拟和物理模拟是分析土体沉降和稳定性的主要手段. 本构模型作为描述土体应力应变关系的数学表达式, 是数值模拟的基础. 土体具有碎散性, 这一基本物理特性导致了其具有压硬性、摩擦性和剪胀性, 这是土的力学特性区别于金属的主要特征, 在土体的本构模型中必须反映这3个基本特性. 传统土力学将土体的变形和强度分离考虑, 分别采用弹性理论和基于刚塑性模型的极限平衡理论分析, 虽然应用广泛, 但由于不能全面地反映土的基本力学特性, 计算结果的精度常常难以满足定量分析的需要. 剑桥模型作为第一个全面反映压硬性、摩擦性和剪胀性的弹塑性本构模型, 实现了变形和强度的统一, 能较好地描述饱和正常固结黏土的应力应变关系, 被视为是现代土力学的开端; 统一硬化模型通过引入一个独特的硬化参数进一步发展了剑桥模型, 将适用范围扩大到超固结黏土. 作者认为, 未来岩土体本构模型研究的挑战是: 如何考虑岩土体在受力过程中土骨架相变与多场耦合, 以解决目前本构模型尚无法定量分析的能源、交通、环境和水利相关的重大岩土工程问题. 超重力物理模拟具有缩尺效应和缩时效应, 克服了常重力物理模拟中模型的应力水平低于原型的缺点, 特别适用于大尺度、长历时问题的模拟. 相较数值模拟, 超重力物理模拟的优势在于能够检验本构模型的合理性, 揭示本构模型无法描述的未知特性. 最后, 介绍了采用数值模拟和物理模拟联合分析大直径钢管桩水平受荷特性的工程案例.      

二氧化钛光催化材料及其改性技术研究进展

二氧化钛(TiO2)光催化技术作为一种绿色、洁净、节能的技术,在污染物治理、光分解水制氢、抗菌环保等领域有着广泛的应用。然而TiO2材料本身大的禁带宽度(Eg=3.2eV)阻碍了其实际应用,进而导致其可见光利用率低、量子产率低。因此制备具有高量子产率且对可见光有快速响应能力的TiO2已成为当前光催化剂研究的关键课题。国内外关于TiO2光催化剂的改性技术逐渐完善并在制备方法、材料形貌和结构控制等方面有新的突破。本文综述了TiO2光催化的制备方法及其反应机理,总结了提高TiO2光催化性能的技术路线,阐明了针对TiO2改性的各种方法的原理及关键技术,同时对TiO2光催化技术存在的问题和发展前景进行了分析和展望。     

Photoluminescence properties of Ca_4La_6(SiO_4)_4(PO_4)_2O_2-based phosphors for wLEDs

The apatite compound Ca_4La_6(SiO_4)_4(PO_4)_2O_2(CLSPO) was explored as the host material for phosphors used in white light-emitting diodes(w LEDs). The crystal structure of the CLSPO host prepared by the solid-state reaction method was investigated with Rietveld refinement. The rare earth ions(Eu~(3+)/Tb~(3+)/Ce~(3+), Tb~(3+)/Tb~(3+), Mn~(2+))activated CLSPO phosphors were synthesized, and their photoluminescence properties, quantum yields, as well as thermal stabilities, were studied. Under near-ultraviolet excitations, the Eu~(3+) and Tb~(3+) -doped CLSPO compounds exhibited red and green emissions with high luminescence efficiencies. Besides, tunable emissions from green to orange were obtained by introducing Mn~(2+) ions into the Tb~(3+) -doped CLSPO samples. The results showed that the phosphors studied may have potential applications for w LEDs.     

Schemes for Teleportation of an Unknown Single-Qubit Quantum State by Using an Arbitrary High-Dimensional Entangled State

We propose a scheme to teleport an unknown single-qubit state by using a high-dimensional entangled state as the quantum channel. As a special case, a scheme for teleportation of an unknown single-qubit state via three-dimensional entangled state is investigated in detail. Also, this scheme can be directly generalized to an unknown f-dimensional state by using a d-dimensional entangled state （d〉f） as the quantum channel.     

An Efficient and Economic Scheme for Remotely Preparing a Multi-Qudit State via a Single Entangled Qudit Pair

We propose some schemes for remote preparation of arbitrary high-dimensional equatorial entangled state via a single bipartite high-dimensional entangled state as quantum channel. We firstly present the remote preparation of bipartite three- and d-dimensional equatorial entangled state by using a single entangled qutrit and qudit pair, respectively, and then directly generalize the schemes to multipartite case. The cases of the quantum channel being non-maximally two-qutrit and two-qudit entangled state are also considered, respectively. In these schemes the required resources are single-particle projective measurement dimensional C-NOT operation. It is shown that the greatly reduced in our schemes. appropriate local unitary operation, auxiliary particle, and highentanglement resource and classical communication cost are both     

Scheme for probabilistic remotely preparing a multi-particle entangled GHZ state

This paper presents a scheme for probabilistic remote preparation of a three-particle entangled Greenberger-Horne-Zeilinger （GHZ） state via three-particle orthonormal basis projective measurement, and then directly generalize the scheme to multi-particle case. It is shown that by using N pairs of bipartite non-maximally entangled states as the quantum channel and N-particle orthonormal basis projective measurement, the multi-particle remote preparation can be successfully realized with a certain probability.     

Controlled remote implementation of quantum operations with high-dimensional systems

We present two protocols for the controlled remote implementation of quantum operations between three-party high-dimensional systems. Firstly, the controlled teleportation of an arbitrary unitary operation by bidirectional quantum state teleportaion (BQST) with high-dimensional systems is considered. Then, instead of using the BQST method, a protocol for controlled remote implementation of partially unknown operations belonging to some restricted sets in high-dimensional systems is proposed. It is shown that, in these protocols, if and only if the controller would like to help the sender with the remote operations, the controlled remote implementation of quantum operations for high-dimensional systems can be completed.     

β-多肽聚合物的优化合成及其抗菌活性

为了解决不同结构的β-内酰胺单体由于反应活性差异而可能出现的聚合反应不完全的问题,选择了侧链带有疏水性基团、反应速率慢的β-内酰胺单体3,3,4,4-四甲基-2-氮杂环丁酮(TM)和侧链带有正电荷的β-内酰胺单体4-[(叔丁氧羰基氨基)甲基]-3-甲基-2-氮杂环丁酮(MM)制备得到β-多肽聚合物,通过考察反应物浓度、反应溶剂类型、引发剂类型等因素来优化聚合反应。实验结果表明,相对于目前常用的以锂作为反离子的引发剂,以钾作为反离子的引发剂可提高β-多肽聚合物的聚合反应速率和难聚合单体的转化率,增加反应物浓度和优化溶剂体系均可改善聚合反应速率。通过测定优化条件下所得聚合物的最小抑菌浓度(ρMIC),观察到聚合物对某些微生物的抗菌活性有所提高。     

大孔载体固定化微生物处理污水研究

通过载体结合法将高效微生物菌群B500或活性污泥固定于不同材质的大孔载体之上,得到固定化微生物.所得固定化微生物置于曝气水槽中,依所用载体密度的不同而形成流化床及固定床型固定化微生物污水处理技术.用所得工艺进行了生活及化工污水的生物处理研究,探讨了不同载体、床型的污水处理能力及其影响因素,考察了相应的CODCr、NH4 -N去除动力学特征.应用克氏定氮法考察了所得大孔载体的微生物负载量,并借助SEM观察了固定化微生物前后载体的表面形态.结果表明,固定化微生物流化床适合于高浓度污水的处理,固定化微生物固定床则在高效去除污水中污染物的同时亦有利于悬浮物的去除,且两种固定化微生物床型处理实际污水时的耐冲击性能良好,出水CODCr、NH4 -N均达到国家污水综合排放一级标准,具有一定的应用前景.     

离子迁移谱仪快速鉴别当归

当归是传统的中药材之一,又称金当归、当归身、当归尾、酒当归、土当归等,为多年生草本植物,全株有特异香气。当归味甘、辛,性温,可以调经止痛、润肠通便、补血活血、也有治疗风湿痹痛和跌扑损伤等的功效。不同产地的当归其药用价值有很大的差异,鉴别当归的产地对研究和应用当归的药理作用具有极重要的意义。离子迁移谱仪(IMS)是一种基于大气压离子化、描述弱电场中离子迁移特性的谱学方法[1]。其