Capillary Electrophoretic Determination of Jinggangmycin A in Formulations Using Direct UV Detection

A simple, fast and reliable method was developed for the analysis of jinggangmycin A （validamycin A） in commercial formulations. The running buffer used was acetate buffer （100 mmol/L, pH 4.7） with 15 kV as the applied voltage. The detection was achieved by using direct UV mode at 200 nm and the detection limit was 0.2 μg/mL. Linearity in the concentration range of 5-500 μg/mL was excellent （RE 〉 0.999）. The run-to-run repeatability （n = 3）, as expressed by the relative standard deviation （RSD） for migration times and peak areas were less than 0.5% and 3.0% respectively. The mean recovery ranged from 97.2% to 101.4%.

Detection and Separation of Inorganic Cations in Natural, Potable, and Wastewater Samples Using Capillary Zone Electrophoresis with Indirect UV Detection

Capillary zone electrophoresis (CZE) is a sensitive and rapid technique for determining traces of inorganic cations in water samples. CZE with indirect UV-diode array detection (CZE-DAD) was utilized to identify several inorganic cations in natural, potable, and wastewater samples. A pH 4.35 background electrolyte system was employed and consisted of 15 mM imidazole, 8 mM malonic acid, 2 mM 18-crown-6 ether as complexing agents, 10% v/v methanol as an organic modifier with indirect absorbance reference at 214 nm. The CZE method involved electromigration injection at 5 kV for 5 s, a separation voltage of 20 kV at 25℃, and a detection wavelength of 280 nm. Six main cations (ammonium , potassium K+, calcium Ca2+, sodium Na+, magnesium Mg2+, and lead Pb2+) were tested, and all but lead, were detected in the water samples at concentrations between 0.03 and 755 ppm with a detection limit ranging between 0.023 and 0.084 ppm. The successful evaluation of the proposed methodology allowed us to reliably detect and separate six metal ions in different water samples without any pretreatment. All water samples were collected from Northern New York towns and the Raquette River water system, the third longest river in New York State and the largest watershed of the central and western Adirondacks.

NON-AQUEOUS REVERSED PHASE HPLC WITH LOW-WAVELENGTH UV DETECTION FOR TRIGLYCERIDE ANALYSIS

Glycerides are first separated to classes of triglycerides(TGs), diglycerides(DGs) and monoglycerides(MGs) by normal phase HPLC on silica gel column. Individual triglyceride separation is then achieved by non-aqueous reversed phase(NARP) HPLC on C_(18) column with UV detection at 215nm.

Test Study on Corona Onset Voltage of UHV Transmission Lines Based on UV Detection

Corona discharge is being detected by UV imaging detection technology at home and abroad in recent years.This technology is used in the corona tests of conductor bundles in this paper.In order to further research the corona characteristic,optimize geometry parameters and diameter of sub-conductor,and increase corona onset voltage of transmission lines,corona tests of three model conductors which are placed inside the outdoor corona cage are conducted.Corona cage could be used to simulate the corona activities on transmission lines under a low voltage and different conditions in an effective and economical way.Photon which was created by UV light as a result of corona discharge on conductors is detected by the UV detection apparatus.The photon number within unit interval,namely photon counting rate is adopted as the parameter of quantifying the intensity of corona discharge.According to the apparent change of photon number,corona onset voltage can be judged.All tests are conducted under almost same atmosphere condition.Using the method,corona onset voltage is acquired.The results indicate that the tests have a good repeatability,in other words,repeating same test twice same result can be aquired.The corona onset voltage can be acquired exactly from the curve of applied voltage vs.photon counting rate.Therefore UV detection apparatus can not only used to find discharge point exactly,but also applied on corona discharge research and live detection for power equipments.The method using in this paper is proved that is a new available method.

The Ultraviolet Detection of Corona Discharge in Power Transmission Lines

Corona discharge is a common phenomenon in power transmission lines external insulation, and it may cause serious defect if without effective detection. The ultraviolet (UV) imagery technology has been widely used to detect the corona discharge in industry in recent years, but some influence factors’ functions are not definite. In this paper, the fracture aluminum strands which is common in power transmission lines were used as the electrode model while a SuperB ultraviolet imager were utilized to detect, the photon count rate was detected with different detect distance, electric field, aluminum strands length and UV gain were applied. Then the multivariate regression analysis (MRA) was taken to calculate the function between the photon count and the factors.

Detection of Three Common Organic Explosives Using Capillary Electrophoresis

In this article, a detection method for organic explosives by capillary electrophoresis (CE) is developed based on previous detection techniques. Firstly, a buffer solution consisting of 50 mmol·L-1 sodium dodecyl sulfate (SDS), 20 mmol·L-1 sodium tetraborate and 5% methanol was prepared and the UV detection in this buffer solution was conducted for three common organic explosives, including TNT, DNT and PETN. Then, the capillary UV detection method was investigated in terms of the transition time repeatability, the linear relationship between mass concentration and peak area and the limit of detection. The results revealed good reliability and stability of this method. In addition, these samples were characterized by photodiode array detector (PDA) to verify the qualitative results of UV detection.

Ion Radiation Detection Using Implanted Ultrahigh Molecular Weight Polyethylene Structures (UHMWPE)

The effect of ion implantation, including Ar+ ion with influences (1 × 1013 - 1015 ions/cm2), on the electrical and optical properties of ultrahigh molecular weight polyethylene (UHMWPE) were investigated with particular emphasis placed on the sensor performance to be used in the field of radiation detection. The obtained results focusing on the effect of the different influences showed a significant change in the electrical conductivity, capacitance and loss tangent. The absorption spectra for UHMWPE samples were recorded and the values of the allowed direct and indirect optical energy gap (Eopt)d, (Eopt)in of UHMWPE and energies of the localized states for the virgin and implanted samples were calculated. We found that the optical energy gap values decreased as the radiation dose increased. The results can be explained on the basis of the ion beam radiation-induced damage in the linear chains of UHMWPE, with cross-linking generated after implantation. The observed changes in both the optical and the electrical properties suggest that the UHMWPE film may be considered as an effective material to achieve ion-radiation detection at room temperature.

基于UV位置图的视频三维人脸表情克隆

为了解决三维人脸表情克隆时的准确性与实时性问题,提出了一种基于UV位置图的视频三维人脸表情克隆方法。首先逐帧读取视频进行人脸检测,然后裁剪出人脸区域,输入到位置图回归网络中得到UV位置图,最后根据UV位置图获得人脸关键点三维信息,驱动三维人脸模型产生变形,完成人脸表情克隆。为了提高克隆效果,构建了基于Ghost瓶颈的轻量级网络,并根据人脸肌肉运动规律与表情变化特征设计了一种新的人脸分区方式及权重,结合Wing Loss损失函数,对卷积神经网络模型进行训练。使用所提算法与其他算法在AFLW2000-3D、COFW-68数据集上进行对比实验,结果表明,所提算法提高了人脸关键点检测的准确率,能够有效解决视频三维人脸表情克隆的准确性与实时性问题。

空间天文紫外偏振探测技术研究进展

新型空间天文探测技术在科学进步和国家发展方面起着至关重要的作用。其高精度的观测提供了独特的机遇,深化了人们对宇宙的理解,同时推动了天体物理学和宇宙学的前沿研究。这些探测不仅为理论模型的验证与发展提供了不可或缺的数据,还在基础物理学领域催生了新理论。在国家层面,拥有先进的空间天文探测技术不仅凸显了国家在科研领域的实力,同时为培养高水平的科研人才提供了重要平台,有助于国家在全球科研舞台上赢得竞争优势。因此,对新型空间天文探测技术的研究和发展显得十分紧迫。天文紫外偏振作为一种创新的空间天文探测手段,相较于传统探测手段,紫外偏振测量技术能够提供多维度的观测数据,进而实现全方位的宇宙感知能力,具备巨大地应用潜力。鉴于目前尚未有关于空间天文紫外偏振探测的系统性综述报告和文章,因此,文中从紫外偏振科学研究的角度出发,总结已有的紫外偏振载荷,挖掘这一领域技术发展的思路和途径,最后对该技术未来发展方向进行展望与总结,为我国在该领域的未来研究提供有益参考。

LC-UV和LC-MS在山楂叶多元酚类成分分析中的应用比较

目的:对LC-UV和LC-MS在山楂叶多元酚类成分分析中的应用进行方法学比较。方法:采用高效液相色谱并联双检测器(VWD和MSD)法。色谱柱为Lichrospher C18(250×4.6 mm I.D.,5μm);流动相A为乙腈,B为0.5%甲酸溶液,梯度洗脱,0-12 min A由11%-17%,12-30 min A由17%-18%,30-45 min A由18%-40%,45-60 minA由40%-100%;流速为1ml/min,三向分流阀分流进入MSD和VWD进行检测;柱温30℃;进样量10μl。结果:LC-MS灵敏度比HPLC法高10倍以上,在检测样品中微量成分时具有很大的优势;另外,LC-MS是根据tR和m/z两项指标来确定成分的类型,对于某些用LC-UV方法不能得到良好分离的组分或在LC-UV图谱上保留时间与对照品相近的其它成分,可以选用选择性离子检测(SIM)进行分析,能避免这些成分的干扰,因而具有高度的选择性和专属性。而LC-UV法操作简便,成本低,流动相选择面较广,因而分离度往往比LC-MS高,在检测样品中具有较好的紫外吸收、较好的分离度以及含量较高的成分时,LC-UV法以其高精密度和高稳定性完全可以达到LC-MS同样的检测结果。结论:LC-MS和LC-UV在山楂叶多元酚类成分的定量分析方面各有特色,可根据不同的检测指标选用不同的检测器。

基于光辐射强度的日盲紫外放电检测结果一致性校准方法

随着紫外放电检测技术的广泛应用,为解决不同型号日盲紫外成像仪的检测结果缺乏一致性和可比性的问题,该文基于MODTRAN模型分析了温度、湿度、气压和检测距离等不同因素对日盲紫外波段光辐射的大气传输过程的影响特性,建立了紫外检测辐射传输模型,搭建了辐射计量一致性校准平台,提出了紫外检测结果一致性校准方法。利用该方法建立了3台不同型号紫外成像仪的检测结果一致性校准公式,可将紫外成像仪测得的光斑面积换算为检测目标产生的光辐射强度。使用3台紫外成像仪对棒-板模型电晕放电和氘灯光源进行紫外放电检测,由一致性校准公式所得检测目标的光辐射强度计算值的相对标准偏差均小于0.1,验证了一致性校准方法的普适性。

依替膦酸钠片的毛细管电泳-间接UV法测定

建立了高效毛细管电泳-间接紫外吸收检测法测定依替膦酸钠。采用未涂层熔融石英毛细管柱,以7mmol/L苯甲酸钠-7mmol/L磷酸二氢钾(pH8.0)为运行缓冲液,分离电压20kV,检测波长224nm。依替膦酸钠在62.5～1000μg/ml浓度范围内线性关系良好,检测限为7.82μg/ml,回收率为98.1%～100.8%,RSD≤1.5%。

高效液相色谱法检测水环境中全氟辛酸铵的研究

全氟辛酸铵(APFO)是一种难降解、生物积累和有毒的全氟和多氟烷基化合物(PFAS),对环境和生物健康构成严重威胁。虽然质谱法对PFAS的检测效果较好,但其成本高昂。高效液相色谱(HPLC)法是一种成本较低的检测方法,但现有的技术稳定性、重现性和效率较低。研究成功建立了一种以高氯酸水溶液和乙腈为流动相能够分离和检测APFO的HPLC法,系统探究了流动相体积比和pH对APFO检测的影响。结果表明,在高氯酸水溶液∶乙腈=60∶40,pH=3.5条件下呈现出最佳的APFO的出峰效果。该方法单样耗费时间少于15 min,检测限为1.01 mg/L,使用更简便的操作和花费更少的时间与成本达到了与其他HPLC方法相近的灵敏度,并在2~50 mg/L的浓度范围具有良好的线性。精密度和准确度实验结果表明,本方法相对标准偏差在9%以内,对实际水体的加标回收率在97.35%~104.80%之间,表现出对复杂样品测定的抗干扰性。本研究展示了该方法在水处理材料开发初期的实验环境中高效且经济地检测高浓度PFAS的巨大潜力。

具有UV探测灵敏性、稳定性和重复利用性的层状铀酰配位聚合物研究

灵敏的UV探测对于工业生产和个人防护非常重要,本研究旨在开发新型UV探测材料。一般而言,铀酰单元具有相对高的UV吸收效率和荧光强度。本课题组成功地在水热条件下制备了一例铀酰配位聚合物[(TEA)2(UO2)5(PhPC)6](TEA=四乙基胺离子,PhPC=(2-羧基乙基)苯膦酸,标记为UPhPC-1)。基于单晶XRD数据的结构分析表明UPhPC-1中有三个不同的铀酰中心,其中两个铀酰单元为五角双锥构型,而第三个铀酰单元为四角双锥构型。全部三个铀酰中心与配体在[bc]平面配位形成无限的铀酰层。通过氢键网格和π-π相互作用,这些铀酰层堆积成整体的层状结构。此化合物具有很好的热稳定性、水稳定性和高抗辐照能力。UV辐照实验结果表明UPhPC-1的本征荧光强度对365 nm的UV辐射高度敏感,检测下限低且响应速率快,而发光强度与UV辐照剂量呈负相关。电子顺磁共振谱分析证实在UV光照射下,UPhPC-1中极有可能产生自由基,造成铀酰荧光部分淬灭。进一步,被淬灭样品中的自由基能够在加热后被去除,从而实现UPhPC-1发光强度的快捷恢复。目前的结果表明UPhPC-1在UV辐照的定量探测领域具有一定的发展潜力。

紫外可见光谱在水质COD检测中的应用研究

加强水质监测是严控水污染和确保水质健康的关键性工作,为加强对水质污染问题的处理,文章提出紫外可见光谱技术在水质COD检测中的应用,从检测原理入手,提出了一种预测模型,以达到检测水质COD的目的。

紫外光固化修复技术(UV-CIPP)在长江大保护建设中的应用

以长江大保护岳阳项目湖滨污水系统收集管网完善工程为例,介绍了紫外光固化修复技术(UV-CIPP)的工艺流程及操作要点。通过采用紫外光固化修复技术,对岳阳市湖滨片区老旧城区长达3.1 km的雨、污水管网进行修复,最大限度地避免了对环境造成的破坏,施工效率高,且符合环保要求,取得了良好的社会及经济效益。

基于红紫外光电传感器的多波段火焰探测方法研究

针对不同火灾发生场景对火焰探测的要求,建立具有火灾特征的火灾探测模型,对多波段红紫外传感器火焰探测机理、多特征数据融合算法和火灾决策判断方法进行研究。选择185~260 nm波段的紫外光电传感器和3.6、4.4、4.8μm波段的红外光电传感器进行火焰探测,采集火焰特征信号数据信息;采用多信号数据融合和特征参数相关性算法,建立多波段火灾特征的火灾探测数学模型,模拟火灾发生场景,训练有关特征参数的最佳配置。研究结果表明,对185~260 nm波段的紫外光和3.6、4.4、4.8μm波段的红外光进行多波段火焰探测,能够满足标准GB 15631-2008《特种火灾探测器》的要求,火焰的识别和决策判断能力提高,试验中无误报和漏报。

紫外分光光度法测定工作场所空气中油雾

建立溶剂洗脱-紫外分光光度法测定工作场所空气中油雾的方法。用玻璃纤维滤膜采集工作场所空气样品,经正己烷超声洗脱,将洗脱液置于1 cm石英比色皿中,在225 nm波长处用紫外分光光度计测定。油雾的质量浓度在0~30.0μg/mL范围内与吸光度线性关系良好,线性相关系数为0.9997,方法检出限为0.3μg/mL,定量限为0.8μg/mL。以采集45 L空气样品计,最低检出质量浓度为0.07 mg/m^(3),最低定量质量浓度为0.18 mg/m^(3)。测定结果的相对标准偏差为1.8%~4.5%(n=6),样品加标回收率为95.7%~104.7%。该方法操作简单,试剂耗材成本低,对实验人员身体危害较小,且检出限低,精密度、准确度、样品稳定性均能够满足职业卫生检测方法要求,适用于工作场所空气中油雾的测定。

山西产酸枣仁HPLC-UV-ELSD特征图谱及7个化学成分的含量测定

目的采用高效液相色谱法建立酸枣仁的特征图谱,并同时测定酸枣仁7个化学成分的含量。方法收集山西临汾大宁、运城闻喜和晋中榆次3个产地的酸枣仁样品,以乌药碱、木兰花碱、维采宁Ⅱ、斯皮诺素、6-阿魏酰斯皮诺素、酸枣仁皂苷A、酸枣仁皂苷B为指标成分,采用Apollo C18柱(250 mm×4.6 mm,5μm)色谱柱,以乙腈和0.1%甲酸水为流动相进行梯度洗脱,柱温为30℃,流速为1.0 ml/min,紫外检测波长分别为227 nm和335 nm,蒸发光散射检测器(ELSD)漂移管温度105℃。空气体积流量为2.5 L/min。结果建立了酸枣仁的特征图谱,标定了7个共有峰,不同检测波长下特征图谱的相似度为0.979-1,相对保留时间和相对峰面积RSD均小于0.3%。在227 nm波长,以木兰花碱为参照峰,乌药碱的相对保留时间为0.84;在335 nm,以斯皮诺素为参照峰,维采宁Ⅱ,6-阿魏酰斯皮诺素的相对保留时间为0.63和1.35;在蒸发光散射检测器(ELSD)检测条件下,以酸枣仁皂苷A为参照峰,酸枣仁皂苷B的相对保留时间为1.1。不同产地酸枣仁中7个成分含量有明显差异,其中乌药碱、木兰花碱、斯皮诺素、酸枣仁皂苷A 4个成分在榆次产地显著高于大宁和闻喜产地。结论本研究所建立的酸枣仁特征图谱方法操作简单,重复性好,并能同时测定酸枣仁中7个成分含量,可为酸枣仁的质量标准研究提供更加全面的依据。

Vision-Based System of AUV for An Underwater Pipeline Tracker

This paper describes a new framework for detection and tracking of underwater pipeline, which includes software system and hardware system. It is designed for vision system of AUV based on monocular CCD camera. First, the real-time data flow from image capture card is pre-processed and pipeline features are extracted for navigation. The region saturation degree is advanced to remove false edge point group after Sobel operation. An appropriate way is proposed to clear the disturbance around the peak point in the process of Hough transform. Second, the continuity of pipeline layout is taken into account to improve the efficiency of line extraction. Once the line information has lbeen obtained, the reference zone is predicted by Kalman filter. It denotes the possible appearance position of the pipeiine in the image. Kalman filter is used to estimate this position in next frame so that the information of pipeline of each frame can be known in advance. Results obtained on real optic vision data in tank experiment are displayed and discussed. They show that the proposed system can detect and track the underwater pipeline online, and is effective and feasible.