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利用紫外脉冲激光和光电倍增管相结合测量油类产品激光诱导荧光的光谱特性和时间特性,分析了荧光光谱的产生,给出了时间分辨荧光光谱的测量,实际测量了几种油产品的时间分辨荧光的光谱分布和荧光寿命,测得的荧光光谱分布结果和其他方法测量结果相同。 相似文献
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以硝酸铁、硝酸钴和柠檬酸为原料,通过溶胶-凝胶微波加热自蔓延燃烧法制备出了纯的立方尖晶石型铁酸钴(CoFe2O4)纳米粒子,然后通过原位聚合将聚苯胺(PAN)对所得粒径约20~30nm铁酸钴纳米粒子进行了包覆,制得了PAN/CoFe2O4纳米复合物。通过傅里叶变换红外光谱(FTIR)、透射电子显微镜(TEM)、X射线衍射(XRD)等测试手段对所得产物的形貌和结构进行了表征。结果表明,PAN链段与CoFe2O4纳米粒子之间存在作用力,通过原位聚合制得的PAN包覆在CoFe2O4纳米粒子表面,X射线粉末衍射和红外光谱进一步证实了PAN/CoFe2O4纳米复合物的形成。荧光分析结果表明,引入CoFe2O4纳米粒子后PAN荧光强度增强。 相似文献
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无汞介质阻挡放电型平面光源(DBD-FFL)是一种有着优良光电特性的环保光源,既可以为液晶显示提供发光均匀的背光,也可以用作具备成本优势的装饰光源。本文叙述了DBD-FFL在近年来取得的重要研究成果,着重介绍了其在电极结构、介质层材料、放电气体以及驱动技术等核心技术方面的研究进展。 相似文献
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Evgeniya V. Pushchina Maria E. Bykova Ekaterina V. Shamshurina Anatoly A. Varaksin 《International journal of molecular sciences》2022,23(9)
Corpus cerebelli in juvenile chum salmon is a multiprojective region of the brain connected via afferent and efferent projections with the higher regions of the brainstem and synencephalon, as well as with multiprojection regions of the medulla oblongata and spinal cord. During the postembryonic development of the cerebellum in chum salmon, Oncorhynchus keta, the lateral part of the juvenile cerebellum gives rise to the caudomedial part of the definitive cerebellum, which is consistent with the data reported for zebrafish and mouse cerebellum. Thus, the topographic organization of the cerebellum and its efferents are similar between fish (chum salmon and zebrafish) and mammals, including mice and humans. The distributions of recombinant adeno-associated viral vectors (rAAVs) after an injection of the base vector into the cerebellum have shown highly specific patterns of transgene expression in bipolar neurons in the latero-caudal lobe of the juvenile chum tectum opticum. The distribution of rAAVs in the dorsal thalamus, epithalamus, nucleus rotundus, and pretectal complex indicates the targeted distribution of the transgene via the thalamo-cerebellar projections. The detection of GFP expression in the cells of the epiphysis and posterior tubercle of juvenile chum salmon is associated with the transgene’s distribution and with the cerebrospinal fluid flow, the brain ventricles and its outer surface. The direct delivery of the rAAV into the central nervous system by intracerebroventricular administration allows it to spread widely in the brain. Thus, the presence of special projection areas in the juvenile chum salmon cerebellum, as well as outside it, and the identification of the transgene’s expression in them confirm the potential ability of rAAVs to distribute in both intracerebellar and afferent and efferent extracerebellar projections of the cerebellum. 相似文献
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Jennifer Therkorn David Drewry III Thomas Pilholski Kathryn Shaw‐Saliba Gregory Bova Lisa L. Maragakis Brian Garibaldi Lauren Sauer 《Indoor air》2019,29(1):143-155
Biocontainment units (BCUs) are facilities used to care for patients with highly infectious diseases. However, there is limited guidance on BCU protocols and design. This study presents the first investigation of how HVAC (heating, ventilation, air‐conditioning) operating conditions influence the dissemination of fluorescent tracer particles released in a BCU. Test conditions included normal HVAC operation and exhaust failure resulting in loss of negative pressure. A suspension of optical brightener powder and water was nebulized to produce fluorescent particles simulating droplet nuclei (0.5‐5 μm). Airborne particle number concentrations were monitored by Instantaneous Biological Analyzers and Collectors (FLIR Systems). During normal HVAC operation, fluorescent tracer particles were contained in the isolation room (average concentration = 1 × 104 ± 3 × 103/Lair). Under exhaust failure, the automated HVAC system maximizes airflow into areas adjacent to isolation rooms to attempt to maintain negative pressure differential. However, 6% of the fluorescent particles were transported through cracks around doors/door handles out of the isolation room via airflow alone and not by movement of personnel or doors. Overall, this study provides a systematic method for evaluating capabilities to contain aerosolized particles during various HVAC scenarios. Recommendations are provided to improve situation‐specific BCU safety. 相似文献