一维车载Ad Hoc网络连接度分析

In this paper we analyze connectivity of one-dimensional Vehicular Ad Hoc Networks where vehicle gap distribution can be approximated by an exponential distribution. The probabilities of Vehicular Ad Hoc Network connectivity for difference cases are derived. Furthermore we proof that the nodes in a sub-interval [z1,z1 +Δz] of interval [0, z], z>0 where all the nodes are independently uniform distributed is a Poisson process and the relationship of Vehicle Ad hoc Networks and one-dimensional Ad Hoc networks ...     

Syntheses,structural characterization and luminescent properties of M2(ATPA)3(DMF)2(H2O)2 (M = Nd,Sm, Eu,Gd, Tb,Dy; ATPA = 2-aminoterephthalate,DMF = N,N-dimethylformamide)

Six isomorphous metal–organic frameworks: M₂(ATPA)₃(DMF)₂(H₂O)₂ (M = Nd (1), Sm (2), Eu (3), Gd (4), Tb (5), Dy (6); ATPA = 2-aminoterephthalate, DMF = N,N-dimethylformamide), were synthesized by the self-assembly of lanthanide ions, 2-aminoterephthalate, DMF and H₂O. Their crystal structures determined by X-ray crystallography reveal interpenetrating frameworks. Compounds 2, 3, 5 and 6 exhibit mainly ligand luminescence at room temperature while 3 exhibits enhanced Eu³⁺ emissions at 77 K. Magnetic studies indicate 4 is paramagnetic with slight Gd³⁺–Gd³⁺ couplings.     

A Novel Bimetallic Chain Based on [Mo(CN)<Subscript>8</Subscript>]<Superscript>3−</Superscript> and Yb<Superscript>3+</Superscript> Ions as Building Blocks in Which Containing Many Intriguing Structural Features

A novel Mo^V–Yb^III bimetallic chain, {[Yb^III(bpy)₂(DMF)(H₂O)][Mo^V(CN)₈]·0.5bpy·4.5H₂O}_n (1) (DMF = N,N′-dimethylformamide; bpy = 2,2′-bipyridine), has been constructed by the reaction of [Mo(CN)₈]³⁻ with Yb³⁺ and 2,2′-bipyridine. Complex 1 is confirmed as a host–guest supramolecular structure by X-ray structural analysis. The neighboring chains interact with each other with two types of hydrogen bonds and two types of π···π interactions. Thus complex 1 has a unique 3D network. Magnetic analysis of 1 indicates the presence of a strong Yb^III single-ion effect owing to spin–orbital coupling within this system.     

多因素共同作用下EPDM对PP稳定性的影响

通过对PP/EPDM共混物进行多因素条件下的老化,研究了EPDM对PP稳定性的影响。由样品老化前后的力学性能、表面形貌、玻璃化转变温度以及表面氧含量的变化分析表明:随着EPDM含量的增加,相应共混物的拉伸强度和断裂伸长率的变化趋势减缓;共混物的降解减弱,表面龟裂纹和脱落现象减轻。由此可见,EPDM能提高PP的抗老化能力。     

亚硝酸型硝化工艺处理高氨氮渗滤液的试验研究

以高氨氮垃圾渗滤液为处理对象,通过边进水边曝气的运行方式,同时控制pH≈7、溶解氧在1~2 mg/L,在SBR内成功实现了稳定的亚硝酸型硝化。当进水氨氮浓度为2 134~2 886mg/L、氨氮负荷高达2 kgNH3-N/(m3.d)时,出水氨氮和亚硝酸盐氮分别为400和1 200 mg/L左右,对氨氮的去除率达到80%以上。游离氨(FA)和游离亚硝酸(FNA)对亚硝态氮氧化菌(NOB)的抑制是实现亚硝酸型硝化的关键。另外,系统内高浓度的亚硝酸盐对异养菌的代谢产生了抑制,对TOC的去除率仅为60%左右。     

高炉基础受力性能的试验研究

通过对3个高炉基础试件在竖向荷载和温度作用下的受力性能试验,分析温度作用对基础的影响,研究各荷载工况下不同约束条件、不同配筋的高炉基础的受力特点。结果表明:温度作用对高炉基础顶部圆台基墩附近影响较大;竖向荷载作用下天然地基的高炉基础底部应力水平较低,而桩基的高炉基础底部应力水平较高;基础上表面与圆台基墩、高炉框架柱、泥砲基础等相交位置以及基础变截面处受力复杂,仅配置构造钢筋的做法有待改进。     

低碳视角下城市新区控制性详细规划编制——以宁波梅山保税港城国际商贸区为例

由于城市新区的土地集约化利用等特点,其控制性详细规划编制更易于将低碳发展理念与空间规划相结合。宁波梅山保税港城国际商贸区控制性详细规划通过构建紧凑、开放的低碳空间,应用低碳模拟评估技术,采用公共交通和步行优先的交通方式,以及低碳设计要素图示化、条文化的二元地块管理模式等,将低碳理念真正落实到空间,有效指导地块开发。     

城市环境敏感地段的“建筑·交通一体化”设计策略初探

城市中的大型建设项目往往处于重要交通节点或多种功能高密度集中的地段,此类地段可称为"环境敏感地段"。在地段内进行建设项目的设计与评价时,需要将"交通"作为内在要素之一纳入建筑设计的范畴综合考虑,实现建筑与步行、轨道、机动车等多种交通系统的整合。以提升城市品质为目标,提出了"建筑·交通一体化"的综合设计策略。     

地质雷达法(GPR)在浅埋特大断面小净距公路隧道中的应用

鉴于浅埋特大断面小净距公路隧道施工难度大,且隧道围岩地质条件的复杂性,为确保隧道施工安全,使用GPR地质雷达对隧道掌子面前方地质情况进行及时准确的预报,并以此为依据对施工进行动态指导,提前采取预防措施,确保了工程安全,达到了较好的预报效果。     

Radio-Optical Dual-Mode Communication Modules Integrated With Planar Antennas

This paper presents new results on integrated devices for radio and free-space optical dual-mode communication. Two novel hybrid packaging schemes using two different microwave printed antenna designs are presented for the integration of radio-optical front-end circuits on a planar compact printed circuit board with shared electrical and structural components. Full-wave electromagnetic (EM) simulations are presented for antenna optimization to minimize EM interference between the radio and optical circuits. A hybrid radio-optical package design is developed, prototyped, and experimentally studied using a modified quasi-Yagi antenna with split directors to form pads for opto-electronic device integration. Dual-mode link connectivity is investigated in simulations and experiments. A data rate of 2.5 Gb/s is demonstrated for the optical channel despite 15–20-dB signal coupling between the optical and microwave circuits.