15 research outputs found

    Strain Response of FBG at Liquid Nitrogen Temperature

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    对光纤Bragg光栅(FBG)液氮(77 K)下的应变传感技术及应变特性进行了研究.实验和分析表明:常温下FBG反射谱中的单个中心峰在低温下会劈裂为多峰,它产生于光纤、粘贴胶和金属基底热膨胀系数间的差异引起的强烈非均匀热弹性应变,使常温下均匀的光栅变啁啾化.建立了多种技术手段,成功消除了低温多峰现象,并测得了FBG低温和常温下的应变传感特性.实验结果表明:FBG的应变灵敏系数与温度无关

    养正消积胶囊辅助GP方案治疗晚期非小细胞肺癌临床研究

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    目的观察养正消积胶囊辅助GP方案治疗晚期非小细胞肺癌(NSCLC)的临床疗效。方法采用随机数字表法将89例晚期NSCLC患者分为对照组44例及观察组45例。2组均采用GP方案;观察组并予养正消积胶囊,每次4粒,每日3次,口服。2组均21d为1个周期,连续治疗2个周期,随访1年。观察2组治疗前后Ki67、Bax、Bcl-2蛋白表达及肿瘤标志物[血管内皮生长因子(VEGF)、骨桥蛋白(OPN)、癌胚抗原(CEA)、糖类抗原199(CA199)]、中医症状评分、生活质量评分,比较2组客观缓解率(ORR)、疾病控制率(DCR)、无进展生存时间(PFS),监测不良反应。结果观察组ORR、DCR明显优于对照组(P<0.05)。与本组治疗前比较,观察组治疗后、随访1年VEGF、OPN、CEA、CA199水平明显降低(P<0.05);对照组治疗后上述指标明显降低(P<0.05),随访1年CEA水平明显降低(P<0.05)。与本组治疗前比较,2组治疗后Ki67、Bcl-2蛋白表达明显降低,Bax蛋白表达明显升高(P<0.05);2组治疗后比较,观察组Ki67、Bcl-2蛋白表达低于对照组(P<0.05),Bax蛋白表达高于对照组(P<0.05)。与本组治疗前比较,2组治疗后中医症状评分(神疲乏力、胃纳少馨、腰膝无力、夜尿频多、头晕目眩)、生活质量评分(躯体功能、认知功能、社会功能、情绪功能)明显改善(P<0.05);2组治疗后比较,观察组上述评分改善明显优于对照组(P<0.05)。观察组PFS明显长于对照组(P<0.05),不良反应明显低于对照组(P<0.05)。结论养正消积胶囊辅助GP方案治疗晚期NSCLC可有效降低患者肿瘤标志物水平,改善生存质量,减少吉西他滨和顺铂的不良反应,提高疗效。福建省卫生厅中医药科研专项课题(wst201210

    Study on temperature, response of fiber Bragg grating at liquid helium temperature

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    进行了液氦温度(4.2K)到室温(298K)温区内光纤Bragg光栅(FHG)温度传感性能的实验研究。重点分析了液氦温度(4.2K)到液氮温度(77K)FBG的温度传感特性。实验表明:FHG传感特性与温度相关。在50K以下,温度响应基本没有变化;50K-77K,波长偏移量随温度上升变化不规律;150K-298K传感特性近似成线性。对比裸光栅与涂敷光栅,涂敷光栅的温度灵敏度远大于裸光栅的温度灵敏度。选用外加热膨胀系数大的聚合物封装,可以显著提高FHG的温敏系数和线性度

    光纤Bragg光栅在77K环境下的温度传感性能研究

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    进行了从液氮温度(77 K)到室温(286 K)的光纤Bragg光栅(FBG)温度传感性能的实验研究。结果表明,FBG的温敏系数与温度相关。低于210 K,FBG的温敏系数变小,这将限制低温环境下FBG作为温度传感器的使用。通过在裸FBG外部涂敷热膨胀系数为61×10-6的丙烯酸脂材料,可以显著提高FBG的温敏系数和线性度。80 K时,有丙烯酸脂包层材料的FBG温敏系数为0.01526 nm/K,而同温度条件下裸FBG的温敏系数仅为0.00449 nm/K

    Assemblies and Properties of Asymmetric Supercapacitors Based on WO3/Carbon Cloth

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    以超级电容器的电极材料制备、性质研究及对组装的非对称超级电容器的性能研究为核心内容,提高超级电容器电化学性能为主要目的,采用水热合成法在碳布基底上合成三氧化钨/碳布和活化后的碳布为超级电容器的电极材料。采用SEM、XRD表征方法对制备的材料进行了形貌表征及物相分析;使用上海辰华电化学工作站对电极材料进行了循环伏安、恒流充放电、交流阻抗等电化学性能测试. 最终得到以三氧化钨/碳布为正极材料、活化后的碳布为负极材料组装成不对称柔性电容器,进行电化学测试,其电位窗口提高到0~1.6 V,电流密度61.9 mA&middot;cm-2时,电容达到58.96 F&middot;cm-2,功率密度0.48 W&middot;cm-2时,能量密度为20.36 mWh&middot;cm-2,同时在电流密度8 mA&middot;cm-2时,循环3000次时表现出良好的循环性能,相较于对称型超级电容器,倍率性能更加优异.The demand for a new generation of flexible, portable, and high-capacity power sources increases rapidly with the development of advanced wearable electronic devices. One dimensional (1D) nanowires structures have been demonstrated as one of the most ideal electrode materials in energy storage systems due to their advantages in both micorstructures and their high surface areas. Here we report a simple process for large-scale fabrication of self-standing composite film electrodes composed of WO3 nanorods on carbon cloth. In order to improve the energy density of supercapacitor, we assembled an asymmetric supercapacitor using WO3 nanorods and activated carbon cloth as positive and negative electrodes, respectively. The scanning electron microscopy (SEM) and X-ray diffraction spectroscopy (XRD) were used to characterize the morphology and structure of the electrode materials, respectively. In addition, cyclic voltammetry (CV), galvanostatic charge-diacharge (GCD) test, and electrochemical impedance spectroscopy (EIS) were employed to study the electrode materials in a three-electrode system. It was found that the WO3 nanorods exhibited attractive electrochemical performance as well as remarkable flexibility with the high areal capacitance of 3347 mF&middot;cm-2 at 5 mA&middot;cm-2. In addition, to improve the electrochemical performance of activated carbon cloth by introducing function groups onto its surface for producing pseudocapacitance and increasing surface area by electrochemically oxidizing CC in the mixed acid solution, it was also shown the high areal capacitance of 1160 mF&middot;cm-2 at 7 mA&middot;cm-2. This method was simpler and more effective compared with the previous strategies for activating carbon materials. The as-fabricated asymmetric supercapacitor based on WO3/carbon cloth exhibited high areal capacitance of 58.96 F&middot;cm-2 at 61.9 mA&middot;cm-2, high energy density of 20.36 mWh&middot;cm-2 at 0.48 W&middot;cm-2 with the operation voltage window expanding to 0 ~ 1.6 V, and excellent lifespan after 3000 cycles. This work opens up a novel, low-cost route to design advanced integrated-array and high performance electrode materials for portable supercapacitor application on a large scale.大学生创新创业基金项目(No. XCX17025)资助作者联系地址:中南民族大学,催化材料科学国家民委-教育部重点实验室,湖北 武汉 430074Author's Address: Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission and Ministry of Education, Hubei Province, South-Central University for Nationalities, Wuhan 430074, Hubei,China通讯作者E-mail:[email protected]

    Investigation on awareness rate of AIDS-related knowledge and prevention among homosexual men in Beijing (北京市男同性恋者艾滋病预防知识知晓率现状调查)

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    Objective To investigate the awareness rate of AIDS-related knowledge and prevention measures among homosexual men in Beijing. Methods The Blued platform registered users whose place of registration was Beijing were investigated by anonymous questionnaire. Results Of the 600 sending questionnaires, totally 500 questionnaires were retrieved. A low level of awareness rate of AIDS-related knowledge was identified among respondents, and there was a significant difference in awareness rate between respondents with different age and education level (P<0. 05). Conclusion Findings of the survey showed a low level of awareness of AIDS-related knowledge and prevention among homosexual men in Beijing, and awareness of AIDS-related knowledge was influenced by age and education level of. It is required to strength the efforts on publicity and education of AIDS prevention among homosexual men. (目的 调查北京市男同性恋者艾滋病预防相关知识知晓率现状。方法 采用无记名方式通过Blued平台对地理位置显示北京地区的注册用户发放600份问卷。结果 回收有效问卷500份。调查对象问卷总体得分较低, 不同年龄、学历的受访人员知晓率比较, 差异有统计学意义(P<0. 05)。结论 北京市男同性恋人群艾滋病预防相关知识的知晓率偏低, 年龄和文化程度影响知晓率。应加强对男同性恋预防艾滋病知识的宣传力度。

    聚集诱导发光

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    聚集诱导发光(AIE)是唐本忠院士于2001年提出的一个科学概念,是指一类在溶液中不发光或者发光微弱的分子聚集后发光显著增强的现象。高效固态发光的AIE材料有望从根本上解决有机发光材料面临的聚集导致发光猝灭难题,具有重大的实际应用价值。从分子内旋转受限到分子内运动受限,从聚集诱导发光到聚集体科学,AIE领域已经取得了许多原创性的成果。在本综述中,我们从AIE材料的分类、机理、概念衍生、性能、应用和挑战等方面讨论了AIE领域最近取得的显著进展。希望本综述能激发更多关于分子聚集体的研究,并推动材料、化学和生物医学等学科的进一步交叉融合和更大发展。 Aggregation-induced emission (AIE), conceptually coined by Prof. Ben Zhong Tang in 2001, refers to a unique photophysical phenomenon non- or weakly emissive luminogens in dilute solutions emit intensely upon aggregation. AIE can solve the aggregation-caused quenching problem that traditional fluorophores are suffering from and hold great technological values for practical applications. The past 20 years have witnessed the rapid development of AIE research, from the restriction of intramolecular rotations to restriction of intramolecular motions, and from AIE to aggregate science, and many original results have been achieved. In this review, we summarize the advances in the field of AIE and its related areas. We specifically discuss the recent progress in AIE area, including material classification, mechanism, concept derivation, property, applications, and challenges. It is hoped that this review will inspire more research into the molecular aggregate level and make significant advances in materials, chemistry and biological sciences

    Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024*

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    JUNO Sensitivity on Proton Decay pνˉK+p\to \bar\nu K^+ Searches

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    The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in pνˉK+p\to \bar\nu K^+ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via pνˉK+p\to \bar\nu K^+ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is 9.6×10339.6 \times 10^{33} years, competitive with the current best limits on the proton lifetime in this channel
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