51 research outputs found

    人性化城市设计的源头——结合我国广场建设谈卡米诺·西特的意义

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    介绍了卡米诺西特在《遵循艺术原则的城市设计》中的设计观点,指出其充分考虑人性空间以及主张灵活多变的手法,并分析其在城市设计中的地位及作用,以及对我国现阶段城市设计尤其是公共空间的启示

    Direct experimental evidence for detailed growth of SiO_x nanowire during CVD

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    在纳米线的制备中,气-液-固(VlS)生长机制得到了人们的广泛认可,但该机制的很多细节还停留在模型阶段.依托实验室自行设计的一台生长条件高度可控的高温化学气相沉积(CVd)系统,采用较为简便的方法,直接在SI片衬底上制备出了SIOX纳米线.通过严格控制实验参数,用离位观测捕捉到了纳米线的催化、形核和长大的一系列过程及其相关细节,并发现纳米线从细到粗的气-液-固(VlS)生长机制.讨论了气-液-固(VlS)机制中气态SI原子的来源以及纳米线的催化、形核和长大过程中的纳米曲率效应和“纳米熟化“现象,取得了对SIOX纳米线VlS催化生长机制的理解的突破.Among the mechanisms for nanowire growths, the vapor-liquid-solid (VLS) mechanism is the most widely accepted.Nevertheless, the growth process and relevant details for the VLS mechanism are not yet fully understood for the complicated nano processes involved.In the present article, with a precise control of temperature, gas flow, pressure, and reaction periods in a home- built high-temperature chemical vapor deposition (CVD) system, detailed processes of catalyzing, nucleation, and growth of the SiOx nanowires and a stepwise non uniformity in diameter of nano- wire were successfully traced.With analysis of these experimental results via nanocurvature and nano ripening effects, a further understanding of the vapor-liquid-solid mechanism, especially the mechanism for formation of the stepwise non uniformity in diameter of nanowires, was achieved for the first time.国家科技计划国际科技合作与交流专项(编号:2008DFA51230);国家重点基础研究发展计划(编号:2007CB936603);国家自然科学基金(批准号:60776007、90401022);中澳科技合作特别基金(编号:20050222);教育部科技重点项目(编号:105099)资

    Determination of ~(230)Th/~(232)Th and correct methods by High Resolution Inductively Coupled Plasma Mass Spectrometry

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    快速可靠的230TH/232TH比值测定方法在230TH定年法中非常重要。实验室在前期工作基础上,建立了高分辨电感耦合等离子体质谱法(Hr-ICP-MS)测定天然样品中230TH/232TH比值的方法。影响230TH/232TH比值精确测定的主要因素是测量过程中强峰拖尾效应和仪器的质量歧视等。238u在236u处的强峰拖尾系数236u/238u可用于230TH/232TH比值的强峰拖尾校正,通过测量不同230TH/232TH比值的标准溶液可获得仪器测量230TH/232TH比值的质量歧视校正因子。采取四酸密闭消解法对砂岩样品进行消解,用bIO-rAd Ag 1x8 Cl-型阴离子交换树脂对钍进行分离,进一步纯化后稀释到一定体积在Hr-ICPMS上进行测量。采用空白-标准-空白样品的测量模式对230TH/232TH比值进行测量。实验室标样的测量结果为(7.29±0.34)x10-6,与参考值(7.33±0.17)x10-6一致。It is very important for the rapid and reliable determination of230Th/232Th in the thorium-230 dating.A method of measuring230Th /232Th in natural samples by high resolution inductively coupled plasma mass spectrometer(HR-ICP-MS) was developed on the base of our former work.The precise and accurate of natural230Th in geology samples is challenging,as the peak tailing to the high intensity of neighboring peak at232Th and the mass discrimination of the instrument.The peak tailing of238U to236U was used to decrease the peak tailing effect of232Th to230Th.The mass discrimination factor K between ture and measured isototpe ratio was calculated after measuring different230Th /232Th ratio solutions.Lab used standard samples was digested in mixed acids of HNO3-HF-HCl-HClO4,and separated by the Bio-rad AG 1×8 Cl-resin.The measurement method of blank-standard-blank- sample procession was used to determinate the230Th /232Th.The measured result of230Th/232Th was at(7.29±0.34)×10-6,which agreed with the reference value of(7.33±0.17)×10-6

    The properties of action potential and sodium-calcium exchange tail current of rabbit right ventricular outflow tract myocytes

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    目的研究兔右室流出道(rVOT)心肌细胞动作电位及钠钙交换尾电流(InCX,TAIl)相关特性,探讨源于rVOT室性心律失常的发生机制。方法采用全细胞膜片钳技术记录兔右室(rV)游离壁和rVOT心肌细胞的动作电位,在不更换细胞及电极内液情况下连续记录InCX,TAIl,对比分析两者动作电位和InCX,TAIl特性。结果兔rVOT心室肌细胞动作电位复极时程(APd)的变异程度大于rV游离壁心肌细胞。在rVOT心肌细胞记录到早期后除极及显著延长的APd。动作电位显著延长及后除极的rVOT心肌细胞所对应的InCX,TAIl到达峰值时程较动作电位正常的细胞延迟,并且电流强度大于rV游离壁对照组心肌细胞(P<0.05)。结论 rVOT心肌细胞APd变异程度大,而且APd显著延长的rVOT细胞InCX,TAIl到达峰值时程延迟及相应电流显著增大,这是rVOT部位好发触发活动的重要机制。Objective To explore the electrophysiological basis of arrhythmogenesis in right ventricular outflow tract(RVOT) myocytes of rabbit heart.The properties of action potential and sodium-calcium exchange tail current(INCX,tail) in rabbit RVOT cells were observed.Methods Patch-clamp technique was used to measure INCX,tail and action potential in single myocytes obtained by enzymatic dispersion of rabbit ventricle.Results Marked variability of action potential repolarization was observed in rabbit RVOT cardiomyocytes.The events of early afterdepolarization(EAD) and marked action potential duration(APD) extension were recorded in RVOT cells.The peak of INCX,tail was delayed significantly in marked APD extension RVOT cells compared to RV free wall cells,and the amplitude of INCX,tail in the former was larger than the latter ones(P<0.05).Conclusion In rabbit RVOT cardiomyocytes,prolonged APD might be the induction factor of delayed afterdeporization and EAD genesis.Under this precondition,the late-peaking and larger amplitude of INCX,tail in RVOT cells might play pivotal role in the mechanism of RVOT arrhythmogenesis.厦门市卫生局资助项目(No.A0000258

    一种定量检测人血清高敏C反应蛋白的化学发光免疫方法

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    旨在建立一种可定量检测人血清高敏CRP的化学发光检测方法(High-sensitivity C-reactive protein quantifiable chemiluminescent immunoassay,hs-CRP CLIA)。首先利用亲和层析和离子交换层析技术从肝硬化病人腹水中纯化出高纯度的天然CRP作为免疫原制备了22株CRP单克隆抗体(单抗),其中13株单抗在磷酸胆碱配体捕获ELISA中呈阳性,然后利用方正滴定法筛选出单抗10C5和10C11建立了hs-CRP CLIA。试剂盒评估结果显示:该方法对血清中干扰物质IgG、血红蛋白、甘油三酯等无非特异性反应;该方法检测灵敏度高,在0.04~20.38mg/L范围内定量检测人血清CRP标准品呈良好线性关系(R2>0.993);该方法准确性高、可重复性好,平均回收率为99%,批内差为4.2%~5.8%,批间差为9.0%~11.5%;该方法与进口商品化高敏CRP ELISA试剂盒平行比较检测90份血清标本,结果显示两者有良好的可比性(r=0.968)。综上,建立的hs-CRP CLIA是一种准确、可靠、可定量的高灵敏C反应蛋白检测方法,该方法的临床应用,有利于改善我国心脏病风险评估及肠炎性疾病预后判断

    Experimental study on reperfusion of intraocular lens

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    作者简介: 祁明信, 男, 1945 年7 月 出生, 教授、主任医师、博士研究生 导师, 主要从事白内障的基础与临 床研究。联系电话: 0591-83570887; E-mail:qihuang@netease. com 通讯作者: 黄秀榕,E-mail:[email protected][中文文摘]目的开展晶状体再灌注的离体和动物实验研究,并对再灌注人工晶状体技术进行评价。方法采用新鲜离体幼兔眼、离体猪眼、新西兰白兔眼,应用自行研制的人工晶状体材料,进行以下实验:(1)体外固化实验;(2)晶状体前囊膜微型撕囊及其稳固性实验;(3)经微型前囊膜开口超声乳化吸出晶状体内容物实验;(4)活的新西兰白兔眼内人工晶状体再灌注实验。结果(1)按硅酮聚合物与固化剂50:1的比例可获得柔软、弹性好、固化时间短(完全固化时间为60min)的注入材料;(2)晶状体前囊膜1.8~2.0mm的连续环形撕囊口具有较好的稳定性,可经该微型开口吸出晶状体内容物并灌注材料;(3)超声能量18%、流量25mL·min-1、负压120mmHg(1kPa=7.5mmHg)为晶状体内容物经微型前囊膜开口吸出的最佳条件;(4)注入灌注材料后可形成由晶状体囊膜包裹的、置换原晶状体皮质和核的、新的再灌注人工晶状体。结论采用再灌注人工晶状体的方法可进行新型人工晶状体再灌注,可为治疗白内障和老视提供参考。[英文文摘]Objective To carry out the experimental study on reperfusion of intraocular lens(IOLs) in vitro or in animal,and to assess the technique of IOLs reperfusion.Methods The following experiments were performed by using self-developed materials in fresh rabbit eyes and pig eyes in vitro,as well as in eyes of alive New-Zea-land rabbits:(1)Solidification study of self-developed material in vitro;(2)Continuous circular capsulorhexis(CCC) in anterior capsule of lens and its stability;(3)Draw of lens contents via phaco through mini-CCC;(4)IOLs ref illing in the eyes of alive New-Zea land rabbits. Results(1) Thematerialwhich was soft, springy and short-term solidification(full solidification time was 60 minutes) were obtained in certain proportion of geland solidified agent(50:1) in vitro; ( 2)The CCC in anterior capsule of lens with 1.8-2.0 mm diameter had very good stability. The lens contents were drawn and the materialwere refilled through themini-CCC; (3) The best conditions of drawing out lens contents through m ini-CCC were phaco energy 18% , flow 25 mL·min- 1, and negative pressure 120 mmH g (1kPa=7.5 mmHg);(4) The new refilled IOLs, which were wrapped by capsule of lens and were replaced original cortex and nucleus of lens, were obtained after thematerial refillied. Conc lusion. New IOLs are refilled through this method, which can prov ide reference for the treatment of cataract and presbyopia.福建省科技三项费用;教育厅重点资助项目基金资助(编号:K98041

    神经网络在DMMP红外光谱判别中的应用

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    介绍了神经网络在化学毒剂红外遥感监测领域应用的概况,探讨了反向传播人工神经网络分类器应用于红外光谱鉴别的可能性。用一个甲基膦酸二甲酯红外光谱数据样本集进行了实际的训练和鉴别性能预测。训练结果表明,这种分类器在一定条件下可以将95%以上的样本正确分离;预测结果表明,经过适当训练的神经网络分类器可以获得70%以上的鉴别率,具备了一定的识别能力

    光通信系统中基于等差矩阵的QC-LDPC码

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    基于等差矩阵的性质特征,提出了一种QC-LDPC(准循环低密度奇偶校验)码的新颖构造方法。该构造方法易于有效编译码,具有良好的围长特性,可有效避免四环,使生成的码字不受短环的干扰,且在硬件实现方面可节省存储空间。仿真结果表明:当误码率达到10-7时,该构造方法造出的高码率QC-LDPC(3780,3542)码与ITU-T G.975中的RS(255,239)码相比,其净编码增益提高了约2.1dB,具有更好的纠错性能;与QC-LDPC(4221,3956)码相比,净编码增益提高了0.35dB

    光通信中基于伽罗华域的QC-LDPC码构造方法

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    为了满足光通信系统对纠错码高码率、低误码率的要求,基于伽罗华域中域的特征提出了一种结构简单、易于编码并且可以有效避免四环的QC-LDPC(准循环低密度奇偶校验)码的新构造方法。并运用该方法构造了适用于光通信系统的FCQC-LDPC(基于域特征的QC-LDPC)(3969,3729)码。仿真结果表明,在误码率=10-7时,所构造的码率为0.937的FC-QCLDPC(3969,3729)码的NCG(净编码增益)比QC-LDPC(4288,4020)码提高了约0.15dB,比Linshu-QC-LDPC(3780,3542)码和经典的RS(255,239)码的NCG分别提高了约0.35和2.1dB。此外,所构造的码的性能与Mackay码的性能相当。因而其纠错性能更强,更适用于高速长距离光通信系统
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