964 resultados para Mac Cormick, Neil


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A series of novel poly(ester-carbonate)s bearing pendant allyl ester groups P(LA-co-MAC)s were prepared by ring-opening copolymerization Of L-lactide (LA) and 5-methyl-5-allyloxycarbonyl-1,3-dioxan-2-one (MAC) with diethyl zinc (ZnEt2) as initiator. NMR analysis investigated the microstructure of the copolymer. DSC results indicated that the copolymers displayed a single glass-transition temperature (T-g), which was indicative of a random copolymer, and the Tg decreased with increasing carbonate content in the copolymer.

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A biodegradable amphiphilic block copolymer, PEG-b-P(LA-co-MAC), was used to prepare spherical micelles consisting of a hydrophobic P(LA-co-MAC) core and a hydrophilic PEG shell. To improve their stability, the micelles were crosslinked by radical polymerization of the double bonds in the hydrophobic blocks. The crosslinked micelles had similar sizes and a narrow size distribution compared to their uncrosslinked precursor. The improved stability of the crosslinked micelles was confirmed by measurements of the CMC and a thermodynamic investigation. These micelles can internalize into Hela cells in vitro as demonstrated by inverted fluorescence microscopy and CLSM. These stabilized nanoscale micelles have potential use in biomedical applications such as drug delivery and disease diagnosis.

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利用改进了的 Mac Diarmid氧化偶联方法合成了苯 /胺封端的苯胺四聚体 .通过对循环伏安曲线的分析 ,给出二聚体经由电化学氧化 -化学偶联成为四聚体的机理 .利用基质辅助激光解吸质谱和红外光谱对产物进行了表征

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The proposed plan for enrichment of the Sulu Sea, Philippines, a region of rich marine biodiversity, with thousands of tonnes of urea in order to stimulate algal blooms and sequester carbon is flawed for multiple reasons. Urea is preferentially used as a nitrogen source by some cyanobacteria and dinoflagellates, many of which are neutrally or positively buoyant. Biological pumps to the deep sea are classically leaky, and the inefficient burial of new biomass makes the estimation of a net loss of carbon from the atmosphere questionable at best. The potential for growth of toxic dinoflagellates is also high, as many grow well on urea and some even increase their toxicity when grown on urea. Many toxic dinoflagellates form cysts which can settle to the sediment and germinate in subsequent years, forming new blooms even without further fertilization. If large-scale blooms do occur, it is likely that they will contribute to hypoxia in the bottom waters upon decomposition. Lastly, urea production requires fossil fuel usage, further limiting the potential for net carbon sequestration. The environmental and economic impacts are potentially great and need to be rigorously assessed. (C) 2008 Elsevier Ltd. All rights reserved.

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The rye B chromosome is a supernumerary chromosome that increases in number in its host by directed postmeiotic drive. Two types of rye B chromosomes that had been introduced into common wheat were dissected into separate segments by the gametocidal system to produce a number of rearranged B chromosomes, such as telosomes, terminal deletions and translocations with wheat chromosomes. A total of 13 dissected B chromosomes were isolated in common wheat, and were investigated for their nondisjunction. properties. Rearranged B chromosomes, separated from their B-specific repetitive sequences on the distal part of the long arm, did not undergo nondisjunction, and neither did a translocated wheat chromosome carrying a long-arm distal segment containing the B-specific repetitive sequences. However, such rearranged B chromosomes, missing their B-specific sequences could undergo nondisjunction when they coexisted with the standard B chromosome or a wheat chromosome carrying the B-specific sequences. Deficiencies of the short arm did not completely abolish the nondisjunction properties of the B chromosome, but did reduce the frequency of nondisjunction. These results confirmed previous suggestions that the directed nondisjunction of the rye B chromosome is controlled by two elements, pericentromeric sticking sites and a trans-acting element carried at the distal region of the long arm of the B chromosome. Additionally, it is now shown that the distal region of the long arm of the B chromosome which provides this function is that which carries the B-specific repetitive sequences.

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无线通信技术在工业网络化控制系统中的应用已成为当今工业领域中的研究热点。然而无线通信技术在恶劣的工业环境中通信质量严重下降,使得现有无线通信技术在工业网络化控制系统中的应用受阻。为此在不断提高和改进无线信号传输性能的同时,更要在控制系统级层面上充分考虑无线通信技术的特点,进行相关系统结构和实时调度机制等方面的改进,以达到使系统产生的通信任务在应用层上得到可靠、实时调度的目的。同时也要从无线网络技术层面上入手,解决上层下达的通信任务在数据链路层中的实时调度问题。要设计适合工业无线网络化控制系统应用特点的MAC协议来有效调度网络所有节点的信息收发,减少高层下达的通信任务在网络中的平均时延,提高吞吐量,进而保证工业无线网络化控制系统的实时性。 因此,本文从工业无线网络化控制系统中的通信任务在数据链路层和应用层上的调度角度出发,以解决、改善工业无线网络化控制系统的实时性和可靠性等性能指标为目的。对工业无线网络化控制系统的结构、应用层调度策略和优化以及数据链路层中的MAC协议进行了系统的研究。主要工作和贡献有以下几点: (1)对工业网络化控制系统的基本问题和引入无线通信技术后产生的问题进行了探讨。在定性分析了工业环境对无线通信的影响及要求的同时,又推导出了无线通信的链路预算模型,并利用Matlab对该预算模型进行了建模,计算出了在工业级噪声指数和工业要求的误码率下,IEEE802.11b和IEEE802.15.4两大主流无线通信技术的链路预算情况及具体的量化数据。 (2)提出了工业无线网络化控制系统的双频二级拓扑结构和多路径传输机制。利用了无线信道特点和路径冗余优势,在系统级上改进了目前无线通信技术在工业网络化控制系统中的应用模式,部分缓解了无线通信技术在工业恶劣环境中的实时性和可靠性问题。为工业无线网络化控制系统结构的设计做了有益的尝试。同时,首次将DS-UWB技术应用于工业网络化控制系统中,设计出了基于该结构的UWB和FF及PROFIBUS的集成方案,为该结构的快速应用提供了有效的途径。 (3)提出了极大容忍无线通信时延的调度算法(GTD)。有效解决了工业无线网络化控制系统中周期性通信任务的实时性问题,部分弥补了因无线网络时延而导致周期性通信任务超时的缺陷。并针对GTD调度算法产生的通信窗口碎片问题进行了优化处理,又提出了面向非周期信息吞吐量最大化的优化调度算法,该算法提高了非周期性通信任务的吞吐量。同时,给出了基于这两种调度算法的非线性规划模型的调度时间表求解方法。 (4)提出了根据通信任务调度时间表进行分配无竞争期的混合CAP和CFP的MAC协议(HAF-MAC)。解决了工业无线网络化控制系统上层下达的周期性通信任务和非周期性通信任务在数据链路层中的实时调度问题,并有效解决了本文提出的应用层调度算法生成的预留时间可能存在浪费的问题。同时,在理论分析了HAF-MAC协议时隙利用率的基础上,提出了基于时隙的HAF-MAC(TSHAF-MAC)协议。TSHAF-MAC协议比HAF-MAC协议提高了时隙利用率,使吞吐量和平均延时得到了进一步改善,进而提高了非周期性通信任务的实时性。最后,对这两个协议进行了仿真建模与验证,进而较系统地解决了工业无线网络化控制系统中的通信任务的实时调度问题。 (5)分别将论文中的第三章和第四章的部分研究成果,在本人博士研究阶段研发的无线智能照明控制系统这一物理实验平台上进行了一定的验证。

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自20世纪60年代以来,探索全球性气候变化规律和环境变迁史的研究工作在世界各国广泛开展。大规模的深海岩芯的研究、中国北方黄土的系统研究、大型湖泊沉积岩芯的研究及对树木年轮、泥炭、珊瑚、冰芯等“自然环境历史档案”开展的研究工作,都为重建古气候和古生态环境提供了大量的资料。洞穴化学沉积物(石笋)由于其特有的微层结构及其内的稳定氧、碳同位素和微量元素所蕴含的古气候与古生态环境信息,并且具有分布广、时间长、信息保存完整等特点,因此,它是研究地球环境变化很好的自然环境历史档案。本论文通过对凉风洞洞穴体系的综合研究和对凉风洞石笋(微层)生长特征及石笋的碳、氧稳定同位素组成的研究,系统探讨了贵州凉风洞石笋的古气候记录和古生态环境意义,得出以下主要结论:1,地表植被的类型及生物量等信息可综合反映于洞穴体系的不同组.分(气样、土样、水样)中。而洞穴的水动力条件也能很好的被洞穴滴水中所含微量(常量)元素记录。根据分析,洞穴综合体系对外界气候与生态环境的响应关系存在一定规律性。通过对比说明,我们所选的凉风洞基岩的溶蚀和缓冲对水体中的信息影响不大,即洞穴滴水较好的继承了土壤水所携带的地表气候与生态环境信息,是理想的研究对象。2.凉风洞石笋具有多个沉积旋回,不同沉积旋回的纹层组合及纹层结构存在一定的差异,指示不同的沉积环境。根据年龄数据判断,旋回①至旋回⑧之间年龄跨度为1570-8000 aBP,以呈缓平顶(柱)对称叠复状的沉积形态组合为主,示洞顶滴水量较大,滴水点相对稳定,且均匀,与全新世较为稳定的气候与环境变化的主旋律相一致。旋回⑧以下至底部石葡萄状沉积物之上部分之间年龄跨度为8000-14220 aBP,期间经历末次冰期晚期向全新世大暖期过渡,受诸如新仙女木事件(Younger Dryas)等的影响,气候变化幅度大,且经历多次反复,石笋生长的沉积学特征表现为斜锥(柱)、尖顶锥不对称叠复纹层组合,示洞顶滴水水量较小但变化较大,且洞穴滴水不稳(固)定。与此时间段内不稳定的气候与环境变化的主旋律也相一致。3.凉风洞石笋上段微层具有典型南方石笋微层发育的特性:微层发育较差,层面多弯曲,层间界面模糊等。下段因为沉积间断较多、风化层面厚及受到若干时段内碳酸钙重结晶而导致晶体穿插层位生长的影响,尽管在某些层位有微层发育,但无法对石笋微层作连续观察记录。根据高精度的石笋TIMS、ICP-MS测年数据和在显微镜下所数石笋微层数量的对比,扣除若干个沉积间断及风化层导致的微层缺失,以及显微镜下肉眼对细小微层计数的误差,我们认为,凉风洞石笋微层是年生长层的可能性较大。4,由于部分测年数据仍在测试中,目前无法精确控制石笋中沉积间断的存在导致的信息缺失,因此,我们仅仅根据部分石笋测年数据,建立了凉风洞石笋在不同时段的生长速率。全新世以来石笋的生长速率在22μm/yr-51μm/yr之间,明显高于末次冰期晚期向全新世过渡这一时间段内的石笋生长速率(16μm/yr)。这些数据间接印证了石笋生长响应于外界气候,尤其是降雨的变化。5.通过对洞穴体系的综合分析对比,我们判断凉风洞洞穴综合体系相对完整,洞穴化学沉积物的6先值较为直接的响应了土壤c压的61t值变化,即反映了地表的植被(c3植物和c;植物)的组成状况。贵州地区降雨80%集中在5-10月份,在此期间,基本受西南季风和东亚季风所控制。西南季风盛行时贵州各地的降雨频繁,是一年中雨量最集中的时期,在东亚季风影响时期,贵州多晴少雨,往往形成干早的天气。又西南季风控制区大气降雨创的值的加权平均值明显低于东亚季风控制区大气降雨δ18O值的加权平均值。因此,贵州地区年均降雨量和年均降雨δ18O值主要取决于西南(印度洋)季风的强弱:西南季风加强,降雨量增加,年均降雨剐、值偏负;西南季风减弱,降雨量减少,年均降雨δ18O值偏正。洞穴滴水的6旧O值变化基本继承了大气降水的别勿值变化。因此,对地处我国西南地区贵州南部的凉风洞,源于洞穴滴水的凉风洞石笋的别勺值变化直接响应了外界的大气降雨量的变化和西南季风与东亚季风相互的强弱交替。6.对凉风洞石笋碳、氧同位素组成的时间序列曲线作20点移动平均,发现,特别是进入全新世后,石笋的引3c值和扩、值几乎具有完全一致的同步变化,只是在变化幅度上在某些时段存在差异。说明在凉风洞石笋反映的14220-1570 aBP时间段内,尤其是10500-1570 aBP期间,本区域气候具有雨热(或干冷)同期的气候特征:在气温较高时间段,西南季风增强,气候湿润多雨,更有利于地表。植物的生长。气温降低时,随着东亚季风增强,西南季风减弱,气候干旱少雨,地表C;植物的生长占有一定的比例。据此重建和恢复了本地区14220-1570 aBP期间的古气候和古生态环境:(1).14220-10500aBP,处于末次冰期晚期,气温较低。凉风洞石笋此时段的司、值都大于-9.8‰,最小值为-9.31‰,最大值达-7.290‰,平均值为-8.552‰。说明凉风洞洞穴地表的生长植被。植物占有一定的组分,石笋的δ18C值受C3植物和C4植物的共同影响。此时段内石笋6、值也存在一定的波动(-5.651‰-6.942‰),考虑到末次冰期晚期先全新世过渡期间气温变幅较大,O'Neil等(1969)所建立的氧同位素平衡分馏方程中的温度变化已不能忽略,并且大气降雨的温度效应作用也比较明显,因此我们对此时段的季风和大气降雨量的变化不作讨论。(2). 10500-9300 aBP,新仙女木事件结束,进入全新世,气温逐渐回升。凉风洞石笋此时段的扩3c值大都小于-9.8‰,最小值为-10.377‰,最大值为-9.267‰,平均值为-9.910‰。凉风洞洞穴地表植被已逐渐由C3植物占主导。此时段石笋δ18C值明显卜降,最小值为-7.420‰,最大值为-6.077‰,平均值为-6.854‰。反映在全新世早期夏季风盛行,降雨量较大,西南季风对本地区全年降雨贡献率大。(3).9300-8300 aBP,经历一段明显温度波动变化。仟3c值在-9.8‰上下波动,最小值为-10.155‰,最大值为-9.096‰,平均值为-9.712‰。凉风洞洞穴地表植被C4植物所占比例存在反复。此时段石笋岁a0值变化幅度不是很大,最小值为-6.796‰,最大值为-6.260‰,平均值为-6.490‰。受冬季风影响,夏季风有一定的减弱,总体降雨量一般,东亚季风对本地区全年降雨贡献率比全新世初期有所增大。(4).8300-3l000BP,俗称全新世大暖期,此时段全球气温明显回升,石笋δ18C值总体逐渐降低,最小值为-n.926编,平均值为-10.496‰。凉风洞洞穴地表植被基本由C3植物所控制。但在扩飞值总体逐渐降低的趋势一F,也存在若干扩3c值明显增大时段,如7700-6700 aBP时段,61七值最大值达-8.110‰,地表C4植物所占比例已不能忽略。此时段石笋6150值变化幅度较大,最小值为-7.373‰,最大值为-5.047‰,平均值为-6.261‰。反映在全新世大暖期的大背景下西南季风和东亚季风的交替以及大气降雨量的变化存在较大的波动,说明了季风气候的不稳定性。(5).3100-1570 aBP,在3100aBP前后,凉风洞石笋的δ18C值和δ18O值均急剧上升,标志进入晚全新世。此时段气温变幅很大,δ18C值总体虽然仍偏低,平均值为-10.275‰,但刻畜介于-6.495-12.097‰之间;δ18C值平均值为-6.184‰,变幅介于-4.677-8.65‰之间,均超过以往任何时段。此时段凉风洞洞穴地表植被基本上仍然由C。植物所控制,始于3100 aBP的急速降温事件使得在全新世晚期开始时段C4植物所占比例有一定的上升。此时段内西南季风和东亚季风反复多次交替,大气降雨量存在较大幅度的变化,说明了季风气候在此时段的很不稳定性。对于169于巧70 oBP百年时间段内石笋的δ18C值和司、值巨大幅度的急剧升高,有待进一步研究,也不排除石笋表层长期裸露受外界污染所致。

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Present study consists of two experiments. In the first experiment, the relationship between psycho-behavioral factors, immune function and the stage of breast cancer was investigated. Fifty six postoperated hospitalized breast cancer patients with radiotherapy were used as the subjects. EPQ and MAC questionnaires were used to assess the patients' psycho-behavioral factors. Blood NK activation level and saliva IgA level were determined as the assessment of their immune function. It was found that the late stage breast cancer patients were more stable but more anxious in emotion. Patients with extrovert personality had higher NK activation and higher fighting spirit than did the patients with introvert personality. The patients with more fatalism had higher levels of saliva IgA and NK activation than did the patients with less fatalism. It was also found that the higher the level of saliva IgA, the higher the level of fighting spirit. In the second experiment, the effect of psycho-behavioral intervention on the immune function and the emotional state of these patients was studied. It was found that the psycho-behavioral intervention significantly increased the level of NK activation and tended to decrease the level of anxious preoccupation. The number of the patients who had to use medicine to increase peripheral blood white cells during radiotherapy was significantly decreased in patients with psycho-behavioral therapy when compared with the control group. Collectively, the data suggested that the immune function, cancer stage were related to the patients' psycho-behavioral factors and the psycho-behavioral intervention could improve the patients' immune function and emotional state.

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This report mainly summarizes the Project MAC A.I. Group work between July 1968 and June 1969 but covers some work up to February 1970. The work on computer vision is described in detail. This summary should be read in conjunction with last year's A.I. Group Report which is included at the end of this Memo.

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Control of machines that exhibit flexibility becomes important when designers attempt to push the state of the art with faster, lighter machines. Three steps are necessary for the control of a flexible planet. First, a good model of the plant must exist. Second, a good controller must be designed. Third, inputs to the controller must be constructed using knowledge of the system dynamic response. There is a great deal of literature pertaining to modeling and control but little dealing with the shaping of system inputs. Chapter 2 examines two input shaping techniques based on frequency domain analysis. The first involves the use of the first deriviate of a gaussian exponential as a driving function template. The second, acasual filtering, involves removal of energy from the driving functions at the resonant frequencies of the system. Chapter 3 presents a linear programming technique for generating vibration-reducing driving functions for systems. Chapter 4 extends the results of the previous chapter by developing a direct solution to the new class of driving functions. A detailed analysis of the new technique is presented from five different perspectives and several extensions are presented. Chapter 5 verifies the theories of the previous two chapters with hardware experiments. Because the new technique resembles common signal filtering, chapter 6 compares the new approach to eleven standard filters. The new technique will be shown to result in less residual vibrations, have better robustness to system parameter uncertainty, and require less computation than other currently used shaping techniques.

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For the design of affinity membranes, protein adsorption in membrane affinity chromatography (MAC) was studied by frontal analysis. According to fast mass transfer, small thickness of affinity membranes and high affinity between the protein and the ligand, an ideal adsorption (IA) model was proposed for MAC and was used together with equilibrium-dispersive (E-D) model to describe the adsorption of bovine serum albumin (BSA) onto cellulose diacetate/polyethyleneimine (CA/PEI) blend membranes with and without Cu2+ chelating. E-D model was found to better describe the initial region of experimental breakthrough curves. The influence of axial dispersion was revealed and it showed the importance of design of the module to homogenously distribute feed solution. IA model was found to be better for the whole experimental breakthrough curve. According to it, the capacity of affinity membranes and the specificity of the interaction are of equal importance for the design of affinity membranes. An optimum feed concentration was also found in the operation of MAC. The discrepancy between experimental optimum feed concentrations and predicted ones from IA model may be due to the ignorance of some experimental effects such as axial dispersion.

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It is in the interests of everybody that the environment is protected. In view of the recent leaps in environmental awareness it would seem timely and sensible, therefore, for people to pool vehicle resources to minimise the damaging impact of emissions. However, this is often contrary to how complex social systems behave – local decisions made by self-interested individuals often have emergent effects that are in the interests of nobody. For software engineers a major challenge is to help facilitate individual decision-making such that individual preferences can be met, which, when accumulated, minimise adverse effects at the level of the transport system. We introduce this general problem through a concrete example based on vehicle-sharing. Firstly, we outline the kind of complex transportation problem that is directly addressed by our technology (CO2y™ - pronounced “cosy”), and also show how this differs from other more basic software solutions. The CO2y™ architecture is then briefly introduced. We outline the practical advantages of the advanced, intelligent software technology that is designed to satisfy a number of individual preference criteria and thereby find appropriate matches within a population of vehicle-share users. An example scenario of use is put forward, i.e., minimisation of grey-fleets within a medium-sized company. Here we comment on some of the underlying assumptions of the scenario, and how in a detailed real-world situation such assumptions might differ between different companies, and individual users. Finally, we summarise the paper, and conclude by outlining how the problem of pooled transportation is likely to benefit from the further application of emergent, nature-inspired computing technologies. These technologies allow systems-level behaviour to be optimised with explicit representation of individual actors. With these techniques we hope to make real progress in facing the complexity challenges that transportation problems produce.

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Kibble, N, ?The Relevance and Admissibility of Prior Sexual History with the Defendant in Sexual Offence Cases? (2001) 32 Cambrian Law Review 27-63 (cited with approval by HL in R v A(2) [2002] AC 45) RAE2008

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Judicial Perspectives on the Operation of s.41 and the Relevance and Admissibility of Prior Sexual History Evidence: Four scenarios. N.Kibble. Crim.L.R. 2005 190. RAE2008

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Kibble, N., Campbell, A., Dishonoured Cheques: A Comparative Analysis (2001) 16/3 Journal of International Banking Law 77-83 RAE2008