基于Android的室内定位系统的研究与实现

为满足定位市场的服务需求,改进传统的定位技术在室内使用存在着定位精确度低、耗电量大等缺点,作者对基于WiFi位置特征匹配的室内定位技术进行了深入研究,分析了各种因素对WiFi信号的影响以及一些常用定位算法的对比,通过在特征库建立阶段采用高斯过滤法剔除误差较大的信号强度值,提高了数据库中采集值的数据精度.在定位阶段采用改进的K加权近邻法,将改进后的算法作为在线匹配算法,有效地避免定位过程中偶然的信号波动给定位带来误差,设计与实现了一个基于Android系统的WiFi室内定位系统.     

含二次隶属函数的模糊二次规划模型求解

基于一种新定义的可调节二次隶属函数,研究了一类带有模糊资源约束的模糊二次规划模型,同时给出了两种相应的求解方法—扩展的Zimmermann算法和扩展的参数规划法。实例表明,两类方法均有一定的合理性和有效性。     

Synthesis process of Ba-ferrites from α-FeOOH and γ-FeOOH and investigation of magnetic properties

The claviform BaFe₁₂O₁₉ crystals were synthesized by the precipitation-toptactic reaction method using α-FeOOH and γ-FeOOH as raw materials respectively. The synthesis processes of BaFe₁₂O₁₉, studied by XRD, SEM, EDS, FT-IR, and TG-DTA techniques, included preparations of precursor γ and precursor α, formations of α-Fe₂O₃ and BaFe₂O₄, and production of rod-like BaFe₁₂O₁₉ through dehydroxylation of pod-like FeOOH, followed by reactions of α-Fe₂O₃ with BaCO₃ and BaFe₂O₄. The crystallinity of α-Fe₂O₃ and BaCO₃ from precursor α was better than from precursor γ due to the direct dehydroxylation of α-FeOOH, resulting in a lower nucleation rate and better crystallinity of BaFe₂O₄. BaFe₁₂O₁₉ prepared from precursor α showed lower crystallinity and purity with a higher length-diameter ratio than from precursor γ. The VSM results proved that the appearance of final products had an important influence on magnetic properties.     

Study on cellular internalization of poly（vinyldiaminotriazine）-based hydrogen bonding type non-viral transgene vector

Previously we successfully prepared poly（vinyldiaminotriazine）（PVDT）-based non-viral vectors which complexed piasmid DNA via hydrogen bonding with adenine-thymine base pairs, in this report, surface charges and complex sizes of this system were further examined. The results showed that PVDT-based polymer could cover surface charges of DNA resulting in slightly negative or neutral complexes. It was also found that the complex sizes were governed by two events： the aggregation induced by the instability of neutral particles, and more compact complexes produced by PVDT-based polymers. In the study of cellular uptake, chlorpromazine and filipin III were used to inhibit clathrin-and caveolae-mediated endocytosis, respectively. We found that PVDT-based systems were transported into cells via a non-clathrin, non-caveolae mediated endocytosis. This special process was studied by temperature inhibition and kinetics assays. It was revealed that such a pathway was characterized by （i） a more en- ergy dependent process and （ii） a much slow transfection-effective internalization.     

Analytical determination of flow resistance characteristic for combination channel inside hydraulic manifold block

Computational fluid dynamics （CFD） was used in conjunction with BP neural network to study the flow resistance characteristic of the combination-channel inside hydraulic manifold block （HMB）. The input parameters of the combination-channel model were confirmed to have effect on the pressure-drop by the numerical method, and a BP neural network model was accordingly constructed to predict the channel pressure-drops. The flow resistance characteristic curves of various channels were achieved, and a performance parameter was given to evaluate the through-flow characteristic of the channel according to the curves. The predictions are in agreement with the numerical computation, indicating that the method can be utilized to accurately determine the flow characteristic of the combination channel with high efficiency.     

Study on Test Methods for Flow Ability of Superfine Powder Extinguishing Agent

According to the physical and chemical characteristics of superfine powder extinguishing agent, three test methods are selected to measure the flow ability. By studying and comparing various test methods, apparatus and conditions, the optimum method and conditions to test flow property of superfine powder extinguishing agent are confirmed.     

古诗词英译中意象的传递——从两首古诗英译看动态意象和静态意象的传递

意象是古诗词的灵魂,是赏析和翻译古诗词的关键.为了使原文和译文达到一样或类似的审美效果,译者要对意象做适当的处理.在翻译古诗词的过程中,原文中的意象应尽量保留.当保留原文意泉可能引起译文读者误解或转交意象可以更好地体现原文时,需做适当的转换.     

高三尖杉酯碱对白血病细胞分化和肿瘤转移的影响

为研究高三尖杉酯碱（Ｈｏｍ）对白血病细胞分化和肿瘤转移的影响．采用四氮唑蓝法检测ＨＬ－６０细胞的分化及测定游离磷含量观测肿瘤细胞Ｎａ＋－Ｋ＋－ＡＴＰ酶和Ｍｇ＋＋－ＡＴＰ酶活性．肿瘤转移模型采用小鼠皮下接种Ｌｅｗｉｓ肺癌观测肺转移灶数和小鼠足跖接种Ｐ３８８白血病细胞观察动物生存期,且用γ射线测定法评价１２５Ｉ－纤维蛋白原与肿瘤细胞的结合能力．结果显示Ｈｏｍ１．５～４．５μｇ／Ｌ能诱导ＨＬ－６０细胞分化,Ｈｏｍ０．１μｍｏｌ／Ｌ２４ｈ对Ｆｒｉｅｎｄ白血病细胞Ｎａ＋－Ｋ＋－ＡＴＰ酶活性抑制,对Ｍｇ＋＋－ＡＴＰ酶活性无影响,Ｈｏｍ０．５～１．５ｍｇ·ｋｇ－１／ｄ剂量下能抑制Ｌｅｗｉｓ癌肺转移和Ｐ３８８白血病细胞淋巴道转移,以及Ｈｏｍ２～１０ｍｇ／Ｌ抑制纤维蛋白原与癌细胞的结合．提示Ｈｏｍ能通过以上途径诱导肿瘤细胞分化和抗肿瘤转移     

粉末冶金法制备混杂增强铜基复合材料的增强体竞争析出行为研究

Copper matrix composites reinforced by in situ-formed hybrid titanium boride whiskers (TiB_w) and titanium diboride particles (TiB_2p) were fabricated by powder metallurgy. Microstructural observations showed competitive precipitation behavior between TiB_w and TiB_2p, where the relative contents of the two reinforcements varied with sintering temperature. Based on thermodynamic and kinetic assessments, the precipitation mechanisms of the hybrid reinforcements were discussed, and the formation of both TiB_w and TiB_2p from the local melting zone was thermodynamically favored. The precipitation kinetics were mainly controlled by a solid-state diffusion of B atoms. By forming a compact compound layer, in situ reactions were divided into two stages, where Zener growth and Dybkov growth prevailed, respectively. Accordingly, the competitive precipitation behavior was attributed to the transition of the growth model during the reaction process.     

强透水地层水平帷幕作用下基坑渗流特性

为研究强透水地层水平帷幕作用下基坑渗流特性,基于Darcy渗流理论,建立了水平封底帷幕作用下基坑渗流计算模型,推导出基坑内涌水量及帷幕底部水压的理论解,并通过室内渗流试验,验证了理论计算方法的可靠性.分析了渗透系数比、帷幕厚度以及帷幕与基坑底部的距离对基坑渗流的影响.研究结果表明:渗透系数比对渗流的影响起主导作用,当渗流系数比为0.01时,涌水量仅为不设帷幕的10％;帷幕厚度对渗流具有一定影响,而帷幕位置对渗流几乎没有影响.建议强透水地层基坑水平帷幕渗透系数比不宜高于0.01,厚度不宜小于4 m.