共查询到20条相似文献，搜索用时 15 毫秒
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Zhi‐Ling Song Xu‐Hua Zhao Wei‐Na Liu Ding Ding Xia Bian Hao Liang Xiao‐Bing Zhang Zhuo Chen Weihong Tan 《Small (Weinheim an der Bergstrasse, Germany)》2013,9(6):951-957
Graphene nanomaterials are typically used in biosensing applications, and they have been demonstrated as good fluorescence quenchers. While many conventional amplification platforms are available, developing new nanomaterials and establishing simple, enzyme‐free and low‐cost strategies for high sensitivity biosensing is still challenging. Therefore, in this work, a core–shell magnetic graphitic nanocapsule (MGN) material is synthesized and its capabilities for the detection of biomolecules are investigated. MGN combines the unique properties of graphene and magnetic particles into one simple and sensitive biosensing platform, which quenches around 98% of the dye fluorescence within minutes. Based on a programmed multipurpose DNA capturing and releasing strategy, the MGN sensing platform demonstrates an outstanding capacity to fish, enrich, and detect DNA. Target DNA molecules as low as 50 pM could be detected, which is 3‐fold lower than the limit of detection commonly achieved by carbon nanotube and graphene‐based fluorescent biosensors. Moreover, the MGN platform exhibits good sensing specificity against DNA mismatch tests. Overall, therefore, these magnetic graphitic nanocapsules demonstrate a promising tool for molecular disease diagnosis and biomedicine. This simple fishing and enrichment strategy may also be extended to other biological and environmental applications and systems. 相似文献
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目的 针对芯片包装载带在生产过程中经常出现的型腔底部和边缘变形、穿孔等缺陷的检测问题,提出一种机器视觉检测方法。方法 首先离线准备配准模板及标准模板图像,然后根据模板在生产过程中进行在线检测。在检测过程中由传感器触发采集待检测型腔图像,然后通过模板匹配方法配准模板图像和待检测图像,并进行异或运算检测两图像差异从而定位缺陷。结果 实验证明边缘变形检测最大错误率为0.45%,底部变形检测最大错误率为0.50%,穿孔检测最大错误率为0.35%,每帧图像检测平均耗时为0.22 s,满足用户错误率不超过1%和每帧耗时不超过0.5 s的要求。结论 该方法能够实时检测芯片载带边缘变形、穿孔等缺陷,有效地实现载带加工生产过程中的质量监控。 相似文献
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目的 通过基于控制策略数据的智能汽车自适应巡航控制功能的人机界面设计研究、实践和评估,为自动驾驶汽车中的智能功能HMI设计提供参考方法和指导.方法 首先通过大量查阅文献资料,了解ACC功能在切入场景下的运行逻辑和控制策略参数.然后结合驾驶员操作及认知任务,抽离出汽车HMI中进行展示的数据信息.最后通过信息架构设计、基础元素设计和多屏互动方案设计等设计分析和实践,对切入场景下汽车多屏HMI进行设计.结果 对ACC功能切入场景下的设计方案进行了可用性测试评估,结果显示ACC的HMI设计方案逻辑清晰,有较高的可用性.结论 基于控制策略数据的HMI设计,能有效帮助设计人员进行复杂汽车智能功能的人机交互设计,提高HMI可用性. 相似文献
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Xiao‐Yu Xu Xiao Lian Ji‐Na Hao Chi Zhang Bing Yan 《Advanced materials (Deerfield Beach, Fla.)》2017,29(37)
Unsafe food is a huge threat to human health and the economy, and detecting food spoilage early is an ongoing and imperative need. Herein, a simple and effective strategy combining a fluorescence sensor and one‐to‐two logic operation is designed for monitoring biogenic amines, indicators of food spoilage. Sensors (methyl red@lanthanide metal–organic frameworks (MR@EuMOFs)) are created by covalently modifying MR into ? NH2‐rich EuMOFs, which have a high quantum yield (48%). A double‐stimuli‐responsive fluorescence center is produced via energy transfer from the ligands to Eu3+ and MR. Portable sensory hydrogels are obtained by dispersing and solidifying MR@EuMOFs in water‐phase sodium salt of carboxy methyl cellulose (CMC‐Na). The hydrogels exhibit a color transition upon “smelling” histamine (HI) vapor. This transition and shift in the MR‐based emission peak are closely related to the HI concentration. Using the HI concentration as the input signal and the two fluorescence emissions as output signals, an advanced analytical device based on a one‐to‐two logic gate is constructed. The four output combinations, NOT (0, 1), YES (1, 0), PASS 1 (1, 1), and PASS 0 (0, 0), allow the direct analysis of HI levels, which can be used for real‐time food‐freshness evaluation. The novel strategy suggested here may be a new application for a molecular logic system in the sensing field. 相似文献
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The performance of state-of-the-art machine translation (MT) systems is still far from being perfect. In this article, we investigate the combination of on-line MT systems to produce better outputs. The basic idea is to apply editorial operations of substitution, insertion, and deletion to candidate outputs in an automatic fashion. The proposed methods are evaluated on the translation task in the travel domain from Chinese to English as defined in the International Workshop on Spoken Language Translation evaluation campaign. Outputs of three on-line MT engines are combined. The proposed method is evaluated on Chinese-to-English MT tasks in the tourism domain. An overall improvement of 1.4 in the BLEU score over the best single-system baseline has been achieved. 相似文献
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Nanogap antennas are plasmonic nanostructures with a strong electromagnetic field generated at the gap region of two neighboring particles owing to the coupling of the collective surface plasmon resonance. They have great potential for improving the optical properties of fluorophores. Herein, nanogap antennas are constructed using an aqueous solution‐based method to overcome the defects of weak fluorescence and photobleaching associated with traditional organic dyes, and a highly sensitive nanogap antenna‐based sensing strategy is presented for the detection of low‐abundance nucleic acid biomarkers via a target‐triggered strand displacement amplification (SDA) reaction between two DNA hairpins that are tagged to the tips of gold nanorods (Au NRs). In the presence of targets, end‐to‐end Au NR dimers gradually form, and the fluorophores quenched by the Au NRs exhibit a dramatic fluorescence enhancement due to the plasmon‐enhanced fluorescence effect of nanogap antennas. Meanwhile, the SDA reaction results in secondary amplification of fluorescence signals. Combined with single‐molecule counting, this method applied in miRNA‐21 detection can achieve a low detection limit of 97.2 × 10?18 m . Moreover, accurate discrimination between different cells through miRNA‐21 imaging demonstrates the potential of this method in monitoring the expression level of low‐abundance nucleic acid biomarkers. 相似文献
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Chunyang Zhou Hongmei Geng Pengfei Wang Chunlei Guo 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(49)
The prospect of programming molecular computing systems to realize complex autonomous tasks has advanced the design of synthetic biochemical logic circuits. One way to implement digital and analog integrated circuits is to use noncovalent hybridization and strand displacement reactions in cell‐free and enzyme‐free nucleic acid systems. To date, DNA‐based circuits involving tens of logic gates capable of implementing basic and complex logic functions have been demonstrated experimentally. However, most of these circuits are still incapable of realizing complex mathematical operations, such as square root logic operations, which can only be carried out with 4 bit binary numbers. A high‐capacity DNA biocomputing system is demonstrated through the development of a 10 bit square root logic circuit. It can calculate the square root of a 10 bit binary number (within the decimal integer 900) by designing DNA sequences and programming DNA strand displacement reactions. The input signals are optimized through the output feedback to improve performance in more complex logical operations. This study provides a more universal approach for applications in biotechnology and bioengineering. 相似文献
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Xiang Ran Fang Pu Jinsong Ren Xiaogang Qu 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(8):1500-1503
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Park KS Seo MW Jung C Lee JY Park HG 《Small (Weinheim an der Bergstrasse, Germany)》2012,8(14):2203-12, 2129
A new platform technology is herein described with which to construct molecular logic gates by employing the hairpin-structured molecular beacon probe as a basic work unit. In this logic gate operation system, single-stranded DNA is used as the input to induce a conformational change in a molecular beacon probe through a sequence-specific interaction. The fluorescent signal resulting from the opening of the molecular beacon probe is then used as the output readout. Importantly, because the logic gates are based on DNA, thus permitting input/output homogeneity to be preserved, their wiring into multi-level circuits can be achieved by combining separately operated logic gates or by designing the DNA output of one gate as the input to the other. With this novel strategy, a complete set of two-input logic gates is successfully constructed at the molecular level, including OR, AND, XOR, INHIBIT, NOR, NAND, XNOR, and IMPLICATION. The logic gates developed herein can be reversibly operated to perform the set-reset function by applying an additional input or a removal strand. Together, these results introduce a new platform technology for logic gate operation that enables the higher-order circuits required for complex communication between various computational elements. 相似文献
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T. Abu-Zayyad M. Al-Seady K. Belov D. J. Bird J. Boyer G. Chen R. W. Clay H. Y. Dai B. R. Dawson Y. Ho M. A. Huang C. C. H. Jui M. J. Kidd D. B. Kieda B. C. Knapp W. Lee E. C. Loh E. J. Mannel J. N. Matthews T. A. O''Halloran A. Salman K. M. Simpson J. D. Smith P. Sokolsky P. Sommers S. B. Thomas L. R. Wiencke C. R. Wilkinson N. R. Wild 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2000,450(2-3):253-269
The High-Resolution Fly's Eye (HiRes) is an observatory for the highest energy cosmic rays. It detects the nitrogen fluorescence light induced by the passage of giant cosmic ray extensive air showers through the atmosphere. A two-site prototype of the observatory was operated from September 1994 to November 1996. In this paper we describe the components of that detector, and the procedures used to calibrate the detector and characterise the atmosphere. Data collected by the HiRes prototype are being used for physics studies, including an analysis of the cosmic ray mass composition in the energy range from 1017 to 1018 eV. 相似文献
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目的提高阈值法在纸病检测系统中的通用性。方法通过实验法获取不同时间段图像灰度数据,依据获取数据的时间段对图像灰度数据进行分类,求得相应时间段的灰度最大平均值、灰度最小平均值、总体灰度平均值以及灰度标准差,应用图表分析法对图像灰度的各种数据进行对比分析,总结出图像灰度变化规律,使用Visual studio 2015进行编程并验证。结果实验结果显示此方案可以较好地适应外界光线的变化,提高纸病检测系统的鲁棒性。结论基于模糊逻辑的纸病检测动态阈值设置方案,可以有效提高阈值法在纸病检测系统中的通用性。 相似文献