Search

奇点光束包括基于相位奇点的轨道角动量（OAM）光束和基于偏振奇点的柱矢量光束（CVB）。OAM光束和CVB都具有正交性,可以作为空分复用的模式应用于光通信中,为光束复用提供一个新的自由度,大幅度地提高光通信系统的容量,在光通信中具有广泛的应用前景。文章首先介绍了OAM光束和CVB的数学描述和物理特性,然后重点综述了其产生和检测方法以及在自由空间光通信和光纤通信中的研究进展,比较了OAM光束和CVB在光通信应用中各自的优势与不足之处。最后,探讨了奇点光束复用光通信的应用方向和发展趋势。

Copyright of Basic & Clinical Medicine is the property of Editorial Office of Basic & Clinical Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Plateau Meteorology is the property of Plateau Meteorology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Telecommunications Science is the property of Beijing Xintong Media Co., Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An analytical method using gas chromatography isotope ratio mass spectrometry (GC-IRMS) combined with solid phase micro-extraction (SPME) was developed to measure the δ 13C values of six typical volatiles commonly occurring in wine (isoamyl acetate, 2-octanone, limonene, 2-phenylethanol, ethyl octanoate and ethyl decanoate) for the first time. SPME selected with a divinylbenzene/carboxen/polydimethylsiloxane fiber was combined with the GC-IRMS for pretreatment optimization. The optimized SPME parameters of extraction time, extraction temperature and salt concentration were 40 min, 40 °C and 10%, respectively. The δ 13C values measured by SPME-GC-IRMS were in good agreement with those measured via elemental analyzer (EA)-IRMS and GC-IRMS. The differences range from 0.02 to 0.44‰ with EA-IRMS and from 0 to 0.28‰ with GC-IRMS, indicating the high accuracy of the method. This newly established method measured the precision within 0.30‰ and was successfully validated to discriminate imported real wine samples with identical label but amazing price differences from different importers. [ABSTRACT FROM AUTHOR]

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this study was to verify the effects of arbuscular mycorrhizal fungi (AMF) on drought resistance of Nyssa yunnanensis, and to explore the mycorrhizal ways of plant conservation. A pot experiment was conducted to study the effects of AMF on anatomical structure characteristics of N. yunnanensis seedlings and their drought resistances under different water conditions. Six water conditions (soil water content) were designed in this pot experiment: 32.32%, 29.63%, 25.86%, 19.39%, 12.93% and 6.46%, and at each water treatment, both sterilization (Low AMF) and no sterilization (High AMF) were contained through adding fungicide benomyl to control AMF. The results showed that AMF colonization rate were significantly decreased in “Low AMF” treatment under different water treatments. Moreover, AMF colonization rate of N. yunnanensis roots significantly decreased with the intensity of increased drought. No significant difference was found in anatomical structure characteristics under mild drought stress conditions (soil water content was 29.63%) whereas N. yunnanensis seedlings showed higher resistances under severe drought stress conditions (soil water content was less than 25.86%). Benomyl treatment significantly affected seven leaf structure indices, such as the leaf cuticle thickness, palisade tissue thickness, upside epidermal thickness, plisade tissue / spongy tissue ratio, tightness of leaf tissue structure, sponge tissue thickness and leaf institutions looseness when soil water content was less than 25.86%, suggesting that high AMF could enhance leaf structure traits on behalf of the drought resistance of N. yunnanensis seedlings when under severe drought stress conditions. Effects of AMF on N. yunnanensis seedlings under 25.86%, 19.39% and 12.93% were more significant than under 6.46% water content of soil. That was because AMF colonization was severely restrained by 6.46% water content of soil. Thus, effects of AMF on plant probably positively related to the colonization rate. Based on principal component analysis of N. yunnanensis 10 structure's index of leaves, and the method of membership function value, leaf traits of main structure index were comprehensively evaluated. The results demonstrated that N. yunnanensis seedlings showed stronger drought resistance under high AMF conditions. The experimental results provided the theoretical basis for the reasonable use of AMF in the protection of endangered species N. yunnanensis. [ABSTRACT FROM AUTHOR]

Objective To investigate the perceptions and experience of patients with sudden deafness, and provide reference for clinical interventions on sudden deafness. Methods Totally 16 patients with sudden deafness were recruited using a purposive sampling method, A face-to-face semi-structured method was adopted, and qualitative data was analyzed Colaizzis method of phenomenological analysis. Results Four themes were identified: difficulty in accepting the disease, reduced quality of life(changes in daily life, being disturbed by accompanying symptoms), uncertainty in illness(inadequate awareness of the disease, worse-than-expected treatment outcome ) and negative emotions(anxiety and depression, losing confidence in treatment). Conclusion Clinical nursing staff should pay more attention on physical and psychological needs and conflicts among patients with sudden deafness, and establish individualized and targeted nursing measures. (目的 深入了解突发性聋患者的疾病感受和体验, 为突发性聋患者的护理干预策略制订提供参考依据。方法 采用目的抽样选取突发性聋患者共16人进行访谈, 以半结构式深入访谈形式收集资料, 并采用质性研究中的现象学研究方法分析提炼主题。结果 突发性聋患者的疾病感受和体验4个主题: 难以接受疾病状态, 生活质量下降(生活状态改变、受伴随症状困扰), 疾病不确定感(疾病认知缺乏、治疗效果不及预期), 负性情绪(焦虑抑郁、对治疗失去信心)。结论 突发性聋患者在生理和心理方面存在诸多需求与困扰, 临床护理人员需予以重视, 结合患者自身需求, 制定个体化、针对性护理措施。)