公交优先模型的建立和计算机仿真分析

实施城市公交运输优先战略是城市道路交通资源优化的主要途径 .提出了在道路交叉口实施动态实时公交优先通行的模式和方案 ,分析了方案实施的条件和技术支持 ,给出了计算机模拟分析的框图 .利用智能交通系统来实现动态的公交优先战略 ,是目前城市道路交通资源相对紧张条件下的一种可行的技术措施     

Seasonal microhabitat relationships of blue grouse in southeastern Idaho

Microhabitat characteristics of blue grouse ( Dendragapus obscurus ) were analyzed in breeding and wintering habitats in southeastern Idaho. Breeding habitats typically were open sagebrush ( Artemisia spp.), mixed shrub, mountain mahogany ( Cercocarpus ledifolius ) , and maple ( Acer grandidentatum ) stands on east to south facing aspects of slopes below 2100 m elevation. Breeding blue grouse selected areas with approximately a 50:50 or greater open to cover ratio. Blue grouse selected areas with higher tree coverage than available on average within the mixed shrub vegetation type. Hens with broods preferred sites with relatively tall (>50 cm) herbaceous vegetation. During autumn and winter, blue grouse preferred high elevation (>2285 m) stands of open (50% tree cover) conifer. Douglas-fir ( Pseudotsuga menziesii ) were preferred as winter roost trees. Sites selected in winter had significantly more Douglas-fir than those selected in autumn.      

Aquatic Insects in Montezuma Well, Arizona, USA: A Travertine Spring Mound With High Alkalinity and Dissolved Carbon Dioxide

An annotated list of aquatic insects from the high carbonate system of Montezuma Well, Arizona, USA, is presented for collections taken during 1976-1986. Fifty-seven taxa in 16 families are reported, including new distribution records for Arizona ( Anacaena signaticollis , Laccobius ellipticus , and Crenitulus sp. [nr. debilis ]) and the USA ( Enochrus sharpi ). Larval stages for Trichoptera, Lepidoptera, Megaloptera, Neuroptera, Chironomidae, and Anisoptera were absent even though the habitat lacks fish, and water temperature, dissolved oxygen, available food, and substrata appear adequate in Montezuma Well. The potential importance of alkalinity in restricting these insect groups is discussed.     

领导效用影响机理模型的建立与实证研究

本文通过探索领导学的相关理论以及合作与竞争理论，建立了领导效用影响机理模型，提出目标依赖性能够调解领导价值和领导效间的关系。并且对在上海企业工作的103个管理者和206个员工做了问卷调查，运用SPSS和EQS软件对问卷数据进行了相关分析和结构分析。实证研究结果表明领导价值减少了竞争性和独立性目标，但其本身并没有加强合作性目标，这项研究的结果和以前的研究表明领导价值与合作性目标的结合为有效的领导提供了基础。同时，发现合作性目标将对领导的有效性和员工行为产生显著的积极影响。     

Relativistic effects in homogeneous gold catalysis

Transition-metal catalysts containing gold present new opportunities for chemical synthesis, and it is therefore not surprising that these complexes are beginning to capture the attention of the chemical community. Cationic phosphine-gold(i) complexes are especially versatile and selective catalysts for a growing number of synthetic transformations. The reactivity of these species can be understood in the context of theoretical studies on gold; relativistic effects are especially helpful in rationalizing the reaction manifolds available to gold catalysts. This Review draws on experimental and computational data to present our current understanding of homogeneous gold catalysis, focusing on previously unexplored reactivity and its application to the development of new methodology.     

Control of the electronic phase of a manganite by mode-selective vibrational excitation

Controlling a phase of matter by coherently manipulating specific vibrational modes has long been an attractive (yet elusive) goal for ultrafast science. Solids with strongly correlated electrons, in which even subtle crystallographic distortions can result in colossal changes of the electronic and magnetic properties, could be directed between competing phases by such selective vibrational excitation. In this way, the dynamics of the electronic ground state of the system become accessible, and new insight into the underlying physics might be gained. Here we report the ultrafast switching of the electronic phase of a magnetoresistive manganite via direct excitation of a phonon mode at 71 meV (17 THz). A prompt, five-order-of-magnitude drop in resistivity is observed, associated with a non-equilibrium transition from the stable insulating phase to a metastable metallic phase. In contrast with light-induced and current-driven phase transitions, the vibrationally driven bandgap collapse observed here is not related to hot-carrier injection and is uniquely attributed to a large-amplitude Mn-O distortion. This corresponds to a perturbation of the perovskite-structure tolerance factor, which in turn controls the electronic bandwidth via inter-site orbital overlap. Phase control by coherent manipulation of selected metal-oxygen phonons should find extensive application in other complex solids--notably in copper oxide superconductors, in which the role of Cu-O vibrations on the electronic properties is currently controversial.     

盐溶液饱和高庙子膨润土膨胀特性的时效性

考虑到缓冲材料膨润土块体从制作到浸水的时间很长,需要分析膨润土膨胀特性的时效性.以高庙子钠基膨润土为试验材料,在保持试样干密度和含水率不变条件下,分别静置0,7,15,30和90 d,利用单向固结仪进行不同总溶解固体(total dissolved solid,TDS)浓度溶液饱和的膨胀力和膨胀变形试验,同时完成部分试...     

由甲醇与丙酮合成甲基乙烯基酮铜基催化剂的研究

用连续流动微型反应一色谱装置评价由甲醇与丙酮合成甲基乙烯基酮（ＭＶＫ）铜基催化剂。研究了载体、助催剂、反应温度及时间对催化性能的影响。结果表明，以ＳｉＯ２为载体并添加Ｃｒ２Ｏ３和ＫＯＨ助催剂，ＭＶＫ选择性大大提高，催化性能也较稳定。用ＸＰＳ分析催化剂表面发现铜的化学状态是Ｃｕ＋，认为Ｃｕ２Ｏ是催化剂活性相组份并使甲醇脱氢为甲醛，后者是生成ＭＶＫ的关键中间物。     

CO在铑上化学吸附的量子化学

用SCC-DV-X_a 法计算CO在金属氧化物助催的铑上的化学吸附。结果定量地证明了Blyhoider 关于CO 在过渡金属上化学吸附模型的正确性。含亲氧性助催剂有利于CO在铑表面的倾斜吸附。金属氧化物助催剂的主要作用在于促进铑反馈电子到CO的2π反键轨道,削弱C—O键,促进了CO的活化。