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1.
基于太赫兹光谱技术的爆炸物类危险品检测 总被引:1,自引:1,他引:1
卢树华 《激光与光电子学进展》2012,(4):45-51
太赫兹(THz)光谱技术识别爆炸物类危险品是一种极具竞争力的新型安检方法。总结了不同研究机构的爆炸物指纹谱数据,建立了可供参考的数据库;讨论了棉布、塑料、皮革、涤纶和硬纸板等常见材料覆盖下隐蔽爆炸物的检测状况;介绍了远距离探测爆炸物的最新研究进展。最后,分析了实战场景中应用THz光谱技术检测爆炸物需要面临的混合爆炸物、复杂环境条件和远距离探测等主要问题,并对未来的发展趋势作了展望。 相似文献
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Yang Li Guangze Yang Lukas Gerstweiler San H. Thang Chun-Xia Zhao 《Advanced functional materials》2023,33(7):2210387
Stimuli-responsive peptides and proteins are an exciting class of smart biomaterials for various applications and have received significant attention over the past decades. A wide variety of stimuli such as temperature, pH, ions, enzymes, magnetic field, redox, etc., are explored. This article provides a review of five intensively studied types of stimuli-responsive peptides and proteins, their design principles and applications, including temperature-, pH-, light-, metal ion-, and enzyme-responsive with an emphasis on the key design concepts and switch function. Moreover, typical examples of their applications are discussed to provide a better understanding of the design concept and underlying methodology. This review will facilitate and inspire future innovation toward new peptide- and protein-based materials and their diverse applications. 相似文献
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The THz-wave generator based on the resonance of phonon-polaritons in GaP enabled THz spectral measurements of organic molecules like DNA/RNA-related molecules in wide frequency range (0.6–5.8 THz). High spectral purity of the generated THz-wave enables even the detection of defect structures of organic compounds, and will give a new tool for molecular sciences. We demonstrated THz imaging of a liver cancer. The THz-wave generator can be made small-size, light-weight system. 相似文献
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Benjamin Born Martina Havenith 《Journal of Infrared, Millimeter and Terahertz Waves》2009,30(12):1245-1254
The influence of water on biomolecular interfaces and functionality has been in the focus of hydration studies. Improved experimental
and computational probes gave insight to this question from different perspectives. The aspect of collective water network
dynamics has been experimentally accessed by terahertz (THz) spectroscopy, which is sensitive to even small solute-induced
rearrangements of the water network in the biomolecular surroundings. THz hydration studies uncovered that the dynamical hydration
shell of saccharides consists of several hundred water molecules and up to thousand water molecules for proteins. Mutations
at the protein surface and inside the core perturb the dynamical hydration, whereas it is noticeable that native wild-type
proteins most significantly affect hydration dynamics. Kinetic THz absorption (KITA) studies of protein folding recently revealed
that solvent dynamics are coupled to secondary structure formation of the protein. The solvent water network is dynamically
rearranged in milliseconds before the protein folds to its native state within the following seconds. THz spectroscopy gives
experimental evidence that collective long-range dynamics are a key factor of biomolecular hydration. 相似文献
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Electronic Terahertz Antennas and Probes for Spectroscopic Detection and Diagnostics 总被引:2,自引:0,他引:2
Grade J. Haydon P. van der Weide D. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》2007,95(8):1583-1591
The terahertz (THz) regime, generally considered to be 0.3-10 THz, is rich with emerging possibilities in sensing, imaging and wireless communications. Since it is non-ionizing and can exploit endogenous contrast mechanisms, it has particular potential for biological applications. These range from screening persons for concealed weapons to advanced biomedical diagnostics at the sub-cellular level. Supporting these applications are electronic techniques for generating, detecting and managing THz "light," including broadband antennas and scanning probes. 相似文献
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L. Consolino S. Bartalini P. De Natale 《Journal of Infrared, Millimeter and Terahertz Waves》2017,38(11):1289-1315
We provide an overview on terahertz (THz) frequency metrology, starting from the nowadays available continuous wave THz sources, discussing their main features such as tunability, spectral purity, and frequency referencing to the primary frequency standards. A comparison on the achieved results in high-precision molecular spectroscopy is given and discussed, and finally, a special emphasis poses on the future developments of this upcoming field. 相似文献
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R. Gente N. Born N. Voß W. Sannemann J. Léon M. Koch E. Castro-Camus 《Journal of Infrared, Millimeter and Terahertz Waves》2013,34(3-4):316-323
We present a numerical method to determine the volumetric water content of leaves from transmission terahertz time-domain spectroscopy data. The method is based on iterative optimization of parameters of an effective medium model for vegetative tissue. We found a very good agreement between measurements performed with this method and direct fresh/dry leaf weight-based water measurements. 相似文献
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Daniel Voß Wissem Zouaghi Mehran Jamshidifar Sebastian Boppel Cormac McDonnell James R. P. Bain Nils Hempler Graeme P. A. Malcolm Gareth T. Maker Maris Bauer Alvydas Lisauskas Adam Rämer Sergey A. Shevchenko Wolfgang Heinrich Viktor Krozer Hartmut G. Roskos 《Journal of Infrared, Millimeter and Terahertz Waves》2018,39(3):262-272
Aiming for non-destructive testing and security applications, we investigate transmission-mode imaging and spectroscopic sensing using terahertz (THz) pulses from a commercial optical parametric oscillator (OPO) in combination with THz detectors based on antenna-coupled field-effect transistors (TeraFETs). The Q-switched OPO generates quasi-continuous-wave THz pulses with a peak power of up to 1 W at a repetition rate between 12 and 90 Hz. The pulses are frequency-tunable between 0.7 and 2.6 THz with a typical linewidth of 50 GHz. We explore detection with fast GaN/AlGaN TeraFETs which hold the potential for multi-pixel and homodyne detection. 相似文献
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Carlito S. PonsecaJr. Ohki Kambara Shintaro Kawaguchi Kohji Yamamoto Keisuke Tominaga 《Journal of Infrared, Millimeter and Terahertz Waves》2010,31(7):799-809
The low-frequency spectra of the amino acids l-alanine and glycine and their peptides were studied using terahertz (THz) time-domain spectroscopy (TDS) at room temperature.
In a previous work (Yamamoto et al., Biophys. J. 89, L22–L24 (2005)), the low-frequency spectra of amino acids (glycine and l-alanine) and their polypeptides (polyglycine and poly- l-alanine) were studied by THz-TDS, and it was found that there is a clear difference in low-frequency dynamics between the
amino acids and the polypeptides. In the present study, amino acids and short peptides were chosen in order to investigate
the effect of polymerization on low-frequency spectra. We focus on two physical quantities to represent the spectral features:
(1) the intensity of the reduced absorption cross section (RACS), which we define from the absorption coefficient and refractive
index, and (2) the exponent in the power law behavior of the RACS. We found that the two physical quantities show different
dependences on peptide chain length, suggesting that the two physical quantities reflect different dynamics and interactions.
The change in RACS intensity may be due to intermolecular or intrachain motion. The validity of the assumption of constant
IR activity in the investigated frequency region is critical to understanding the origin of the variation in the exponent
with chain length. 相似文献
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太赫兹波能穿透许多物质,相对于可见光和X射线,其具有非常强的互补特征;它的光子能量极低,且没有X射线的电离性质,因此太赫兹成像技术的应用前景非常广阔。在太赫兹成像系统中,系统参数的合理选择,软件部分的合适控制,对系统的成像结果有着至关重要的作用。从调试过程中得到的图像来看,不合适的处理如斩波器、锁相放大器参数选择不当等,将会导致两行之间错位、信噪比不高,以至于图像失真,甚至无法辨认。对出现这种错位现象的原因进行了研究,在硬件参数选择和软件两个层次,对导致该现象的系统偏差进行控制、补偿和消除,最后给出成像结果。扫描成像结果表明,搭建了稳定合适的光路,选择了适当的仪器参数,在软件上控制了偏差,通过实验和测试,系统达到了较好的成像效果。 相似文献
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THz信号处理与分析的研究现状和发展展望 总被引:1,自引:1,他引:1
本文对THz信号的特点、THz信号的产生技术、THz信号的探测技术、THz时域光谱(THz-TDS)技术、THz信号的处理技术,以及THz 信号应用技术等当前的研究现状进行了综述,并对未来可能的发展做了展望. 相似文献
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Taiichi Otsuji Stephane Boubanga-Tombet Akira Satou Maki Suemitsu Victor Ryzhii 《Journal of Infrared, Millimeter and Terahertz Waves》2012,33(8):825-838
This paper reviews recent advances in spectroscopic study on ultrafast carrier dynamics and terahertz (THz) stimulated emission in optically pumped graphene. The gapless and linear energy spectra of electrons and holes in graphene can lead to nontrivial features such as negative dynamic conductivity in the THz spectral range, which may lead to the development of new types of THz lasers. First, the non-equilibrium carrier relaxation/recombination dynamics is formulated to show how photoexcited carriers equilibrate their energy and temperature via carrier-carrier and carrier-phonon scatterings and in what photon energies and in what time duration the dynamic conductivity can take negative values as functions of temperature, pumping photon energy/intensity, and carrier relaxation rates. Second, we conduct time-domain spectroscopic studies using an optical pump and a terahertz probe with an optical probe technique at room temperature and show that graphene sheets amplify an incoming terahertz field. Two different types of samples are prepared for the measurement; one is an exfoliated monolayer graphene on SiO2/Si substrate and the other is a heteroepitaxially grown non-Bernal stacked multilayer graphene on a 3C-SiC/Si epi-wafer. 相似文献
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The noise performance of photoconductive terahertz detectors is analyzed and the tradeoff between low-noise and high-responsivity operation of photoconductive detectors is investigated as a function of device parameters and operational settings. The analysis is conducted on two general photoconductive detector architectures, symmetrically pumped and asymmetrically pumped photoconductive detector architectures. The results indicate that the highest signal-to-noise ratios are offered by the symmetrically pumped and asymmetrically pumped detector architectures for the photoconductive detectors based on short-carrier lifetime and long-carrier lifetime semiconductors, respectively. 相似文献
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钝感RDX及HMX炸药的太赫兹光谱分析 总被引:2,自引:0,他引:2
采用太赫兹时域光谱技术(Terahertz time-domain spectroscopy,THz-TDS)对钝感RDX(黑索金)和HMX(奥克托金)炸药在0~2.5THz频段的太赫兹吸收光谱进行了探测.得到了待测样品的太赫兹吸收光谱,确定了其特征吸收峰的位置并与其他研究机构所测吸收谱进行了对比分析.实验结果表明:利用THz-TDS技术可以对炸药进行检测和识别,同时可以对样品组成的细微变化进行分析和鉴别.为利用THz-TDS技术研究其他爆炸性物质,建立爆炸物的指纹谱库提供了科学依据. 相似文献
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石墨烯太赫兹波段性质及石墨烯基太赫兹器件 总被引:1,自引:0,他引:1
石墨烯在太赫兹波段的优异性质,使其在太赫兹源、太赫兹探测和太赫兹调控三个方面都具备广阔的应用前景。主要对石墨烯在太赫兹波段的性质及石墨烯基太赫兹器件的相关研究进行了综述,并对石墨烯在太赫兹波段的应用前景进行了展望。在石墨烯太赫兹波段性质方面,主要介绍了石墨烯的电导模型、静态和超快光谱响应特性,以及表面太赫兹波辐射特性。在石墨烯基太赫兹器件方面,主要综述了基于光、电、磁调控的太赫兹主动器件,石墨烯基超材料的太赫兹调制器,基于阻抗匹配的减反射调控器件,以及可调太赫兹源器件的最新研究进展。 相似文献
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Yifan Yang Haichao Zhu Dingkang Liu Hong Luo Ruilong Chang Yue Ji Wenbing Yao Jun Yin Xiangdong Gao 《Advanced functional materials》2023,33(30):2301011
The efficient delivery of biologics into cells provide unique opportunities to modulate intracellular targets not druggable by conventional small molecules. The supercharged polypeptide (SCP) has become a novel intracellular delivery system due to their special advantages, including enhanced delivery efficiency and serum tolerance. However, owing to their cationic charge and non-specificity characteristics, the in vivo application of SCP is limited. Here, an activatable SCP (ASCP) with a pH-sensitive charge shielding sequence (CSS), a protease cleavage site, and SCP are engineered. This system shows the potential to reduce the non-specific binding and effectively deliver various cargo (peptide, protein, small molecule, and siRNA) into the cytosol not only in vitro but also in vivo. Furthermore, an ASCP fusion protein is designed to co-delivery of peptide (KLA)/siRNA (IKBKE) with different tumorigenesis pathways to triple negative breast cancer (TNBC) for optimal therapeutic outcomes. It is believed that ASCP delivery system will facilitate the development of bioactive molecules for use against intracellular targets. This simple yet versatile delivery system can also pave the way for the co-delivery of multiple therapeutic cargos to address the emerging needs of combination cancer therapy. 相似文献