88 research outputs found

    Using Feedback Servo Mechanism to Scale-up the Measurement Range on the Shift by Hore Sensor

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    霍尔器件可用于微位移测量 ,但通常只能测 1mm左右的位移 ,并在实用时要设计复杂的磁路以保证在测量范围内梯度磁场为均匀的。本文采用反馈随动机构带动霍尔传感器跟踪被测体的位移 ,从而扩大了测量范围 ,且不需要在测量中保持均匀梯度磁场Hore part may be used in measuring tiny shift,but in practice,a complicated magnetic circuit should be designed to assure the uniform gradient magnetic field in the measurement range,which is usually within 1mm.In this paper,a feedback servo mechanism is used to make the Hore sensor tracking the shift of the measured object.In this way the measurement range of shift is extended greatly.And the uniform gradient magnetic field during measurement is not demanded.福建省自然科学基金资助项

    一种基于各向异性磁传感器的车辆检测方法

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    针对目前车辆检测方法受环境影响大、精度低、成本高和安装维护复杂等问题,文章提出一种基于各向异性磁阻效应的车辆检测方法,利用两个各向异性磁阻传感器组成三轴检测电路,通过检测车辆对地磁场的扰动来进行车辆检测。详细了介绍了地磁检测原理、硬件构成和软件设计,实验结果证明利用该地磁检测模块进行车辆检测有一定的优势

    不完全川崎病早期诊断的探讨

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    目的探讨小儿不完全川崎病(Ikd)早期诊断的方法,以提高对该病的临床诊断水平,减少冠状动脉损害的发生。方法对2008年1月-2012年5月在厦门市第三医院儿科住院的21例Ikd患儿的临床表现及辅助检查进行回顾性分析。结果持续发热、川崎病面容、手足硬肿、肛周潮红或脱皮、卡巴红等症状及体征有助于Ikd的早期诊断。炎症指标(ESr及CrP)、WbC及bnP早期增高以及发病10 d内心脏彩超检查发现冠状动脉扩张是早期诊断Ikd可靠的辅助指标。21例Ikd患者中发生冠状动脉扩张10例,占47.6%,与典型kd比较,差异有统计学意义(P<0.05)。结论由于Ikd病例中冠状动脉病变发生率较高,对持续发热5天以上的婴幼儿,当出现川崎病面容、手足硬肿、肛周潮红或脱皮及卡巴红等表现中的2~3项时要引起重视,尽早做相应的辅助检查及心脏冠状动脉检测,尽早明确诊断,给予早期治疗,以避免冠状动脉损害的发生

    Slow Magnetic Relaxation in Sandwich-Type Tetranuclear Dysprosium Complex with TMe Q[6](TMe Q[6]=α, α, δ, δ-Tetramethylcucurbit[6]uril)

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    报道了2个基于四甲基取代六元瓜环的三明治型四核稀土簇合物,[ln4(μ3-OH)4(μ2-OH)2(H2O)4(nO3)2(TME Q[6])2]·(nO3)4·26H2O(ln=dy,1;ln=Tb,2)。晶体结构分析显示2个簇合物包含2个四甲基取代瓜环夹心的四核稀土立方烷结构,[ln4(μ3-OH)4]8+。磁性研究显示化合物1显示了慢磁弛豫行为。由于六元瓜环配体可以有效的传递能量给稀土铽离子,化合物2具有较好的发光性能。Two TMe Q[6]-supported sandwich tetranuclear complexes, [Ln4(μ3-OH)4(μ2-OH)2(H2O)4(NO3)2(TMe Q[6])2](NO3)4·26H2O(Ln=Dy, 1; Ln=Tb, 2), have been prepared and characterized.Crystal structural analysis reveals that both complexes contain a cubane-like [Ln4(μ3-OH)4]8+cluster core sandwiched between two TMe Q[6] macrocycles.Magnetic investigations indicate that complex 1 displays slow magnetization relaxation.Complex 2exhibits intense photoluminescence owing to the efficient energy transfer from TMe Q[6] ligand to Tb3+ion.国家自然科学基金(nos.21422106;21371144;21431005)资助项

    Preparation and Electrochemical Lithium Intercalation Performance of Segmented Carbon Nanofibers

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    以泡沫镍为催化剂 ,在 6 0 0和 70 0℃下 ,以CVD法热解乙炔气体制备大量的纳米碳纤维 .随着制备温度增加 ,纳米碳纤维直径变小 ,竹节状含量减少 ,d0 0 2 值减小 ,微晶片层平面Lc 和La 值增大 ,碳材料的可逆容量则下降 .分别用透射电镜、X射线衍射和拉曼光谱观察和测定了纳米碳纤维的形貌、微结构 ,发现在不同条件下生长的纳米碳纤维有不同的形貌和结构 .对纳米碳纤维的电化学嵌锂性能的研究表明 ,纳米碳纤维的结构对其电化学嵌锂容量和充放电循环寿命起重要影响 ,制备温度越低 ,纳米碳纤维的石墨化程度越差 ,可逆嵌锂容量相应要高一些Segmented carbon nanofibers were prepared by pyrolysis of acetylene on foam Ni at 600 and 700℃ in a fixed bed flowed-reactor. The morphology, microstructure and lithium insertion properties of these carbon nanofibers were investigated by TEM, XRD, Raman and electrochemical methods. Through TEM observations, it was found that this kind of carbon nanofibers was composed of lens-like segments with nearly equal separation stacking along the nanofiber axis. When the reaction temperature was 600℃, segmented carbon nanofibers were the major production. However, when the reaction temperature increased to 700 ℃, the content of segmented carbon filaments decreased and their diameter became smaller. The crystallite size d 002 and L c were determined by the 002 carbon Bragg peak of XRD patterns using the Bragg and Scherrer formulas. The intensity ratios of the 1350 cm -1 line and the 1580 cm -1 line (R=I D/I G) was used to evaluate the L a value, which was inversely proportional to the effective crystallite size in the direction of the graphite plane (L a). With the reaction temperature increased, the d 002 value decreased, L a and L c values increased, which indicated the degree of crystallinity increased. Segmented carbon nanofibers were used as positive electrodes of C/Li cells. The first charge capacities of C/Li cells were 480 and 300 mAh/g for samples produced at 600 and 700℃, respectively. The samples at 600℃ showed capacities higher than the theoretical value of graphite, which was attributed to accommodation of more lithium at the edge of graphene layers and on the surface of graphene layers according to the mechanisms of lithium insertion in carbons prepared by low-temperature pyrolysis of hydrocarbons. As confirmed by the XRD and Raman spectra, the samples at 700℃ had larger L a and L c, which led to the capacity decreasing.国家自然科学基金 (6 0 2 710 0 9);; 浙江省自然科学基金 (5 0 110 9,2 0 0 0 5 3)资助项

    H5N1禽流感病毒血凝素抗原快速检测试剂对不同现场标本的检测比较

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    利用H5亚型禽流感病毒血凝素抗原快速检测试剂“H5-HA(Ag)Dot-ELISA(H5-Dot)”对来自陆禽、水禽的484份气管拭子、泄殖腔拭子和粪便拭子标本进行检测,结果:①不同采集方式的H5N1阳性标本的检出率高低有别,气管拭子的检出率最高,泄殖腔拭子次之,粪便拭子最低(P<0·05),因此建议现场采样时应尽可能采集气管拭子标本;②陆禽标本检出率显著高于水禽标本(P<0·05),对病毒培养阳性的陆禽气管拭子检出率达80%(95%CI:70·6%~87·8%),对水禽气管拭子标本的检出率为38%(95%CI:26·9%~49·4%),可能与标本中病毒滴度高低有关;③有症状与无症状陆禽标本的检出率无显著差异。另外,H5-Dot试剂对333份非H5病毒气管拭子标本的特异性为99·4%(95%CI:97·9%~99·9%)。这些结果表明,H5-Dot是一种较为可靠的H5亚型禽流感病毒早期快速检测方法,在缺乏仪器设施和高素质专业技术人员的H5N1禽流感病毒防控第一线具有重要推广价值

    一种新型H5N1禽流感病毒血凝素抗原快速检测试剂的建立

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    利用5株广谱特异性抗H5亚型血凝素单克隆抗体和酶联免疫渗滤技术成功地建立了一种适于现场检测H5亚型禽流感病毒血凝素蛋白的抗原快速检测试剂H5-HA(Ag)Dot-ELISA。该试剂对41株代表当前亚洲地区流行的各种遗传变异亚系H5N1禽流感病毒检测均为阳性,对多数毒株的分析灵敏度优于0.1个血凝滴度(HA titer),其中部分优于0.01个血凝滴度;比较该试剂与早期开发的同类ELISA试剂,发现前者对后者未能检出的H5N1新变异株检测均为阳性;利用该试剂和商品化Directigen Flu A(BD)试剂检测两株H5N1病毒株,提示前者灵敏度高于后者;该试剂对一株H5N1病毒的检测灵敏度与标准RT-PCR相当;该试剂对24株非H5亚型病毒检测均为阴性,显示出良好特异性。以上结果提示,此研究建立的H5N1病毒抗原快速检测试剂在H5禽流感现场检测上具有较好的应用前景

    Development of aquantitative ELISA detection method for Varicella Zoster Virus(VZV) antigen

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    目的:建立水痘-带状疱疹病毒(VzV)抗原的双抗体夹心ElISA定量检测方法,用于质控VzV灭活疫苗研发和生产中抗原含量。方法:以VzV中和单抗5f6C8为包被抗体、8H5d1为酶标抗体,构建定量检测VzV抗原的双抗体夹心ElISA方法,并对本方法的特异性、灵敏度、准确性、线性和稳定性等性能进行分析。结果:建立的双抗体夹心定量检测VzV抗原的ElISA方法,线性范围为0.4μg~13μg/Ml,相关系数为r2=0.994,定量限度为0.4μg/Ml;变异系数CV80%。与VzV以外的相关病毒样本没有交叉反应。结论:构建的VzV抗原ElISA定量检测方法的各项性能符合定量检测需要,可用于VzV灭活疫苗的研发和生产过程的抗原含量检测。Objective:To develop a quantitative enzyme linked immunosorbent assay(Q-ELISA) to determine the concentration of Varicella Zoster Virus(VZV) antigen.This method was used to determine VZV antigen content at each stage of VZV inactived vaccine developing and manufacturing process.Methods: A double antibody sandwich Q-ELISA was developed to determine concentration of VZV antigen,which was based on the the high-affinity neutralizing monoclonal antibodies 5F6C8 as capture antibodies,and 8H5D1 as HRP-labeled antibody.The performance of reagent were evaluated.Results: The Q-ELISA for VZV antigen content was successfully developed.The reagent had good performance.The quantitation scope was 0.4 μg~13 μg/ml,The coefficient correlation was 0.994,the limit of detection was 0.4 μg /ml,the recovery was between 87.5% and 111.6%.The stability was up to 80% after reagent was heated for 6 days at 37℃.The variation coefficient was lower than 15%,and the reagent was no reaction with other sample except VZV antigen.Conclusion: The Q-ELISA for VZV antigen was developed with good specificity,accuracy and stability.The method can be used to determine VZV antigen content during development and production of VZV inactived vaccine

    Preparation and electrochemical lithium intercalation performance of segmented carbon nanofibers

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    Segmented carbon nanofibers were prepared by pyrolysis of acetylene on foam Ni at 600 and 700degreesC in a fixed bed flowed-reactor. The morphology, microstructure and lithium insertion properties of these carbon nanofibers were investigated by TEM, XRD, Raman and electrochemical methods. Through TEM observations, it was found that this kind of carbon nanofibers was composed of lens-like segments with nearly equal separation stacking along the nanofiber axis. When the reaction temperature was 600degreesC, segmented carbon nanofibers were the major production. However, when the reaction temperature increased to 700degreesC, the content of segmented carbon filaments decreased and their diameter became smaller. The crystallite size d(002) and L-c were determined by the 002 carbon Bragg peak of XRD patterns using the Bragg and Scherrer formulas. The intensity ratios of the 1350 cm(-1) line and the 1580 cm(-1) line (R =I-D/I-G) was used to evaluate the L-a value, which was inversely proportional to the effective crystallite size in the direction of the graphite plane (L-a). With the reaction temperature increased, the d(002) value decreased, L-a and L-c values increased, which indicated the degree of crystallinity increased. Segmented carbon nanofibers were used as positive electrodes of C/Li cells. The first charge capacities of C/Li cells were 480 and 300 mAh/g for samples produced at 600 and 700degreesC, respectively. The samples at 600degreesC showed capacities higher than the theoretical value of graphite, which was attributed to accommodation of more. lithium at the edge of graphene layers and on the surface of graphene layers according to the mechanisms of lithium insertion in carbons prepared by low-temperature pyrolysis of hydrocarbons. As confirmed by the XRD and Raman spectra, the samples at 700degreesC had larger L-a and L-c, which led to the capacity decreasing
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