三氧消毒杀菌与紫外线消毒杀菌效果的研究

对三氧消毒杀菌与紫外线对空气杀菌消毒的效果进行了比较，选择供应室无菌间的两间面积相同的房间，使用三氧消毒机和紫外线灯，照射到各自规定的时间进行空气采样，暴露15min后，置37℃培养24h，观察结果并进行菌落计数。结果表明，三氧消毒杀菌机的消毒作用优于紫外线灯，其消毒杀菌的安全性高，杀菌效果明确，是空气消毒理想的一种新型消毒方法。     

化妆品车间空气消毒方法效果比较

评价几种消毒方法对化妆品车间空气的消毒效果。分别使用紫外线照射消毒法、甲醛蒸熏消毒法、戊二醛消毒液气溶胶雾化消毒法、臭氧气体发生器消毒法4种方法进行消毒,然后用平皿沉降法进行采样评价分析,试验结果表明,戊二醛消毒法和臭氧消毒法可以代替紫外线消毒法和甲醛消毒法进行化妆品车间空气常规消毒。     

光催化水处理消毒的原理、材料和反应器

传统的水处理消毒技术使用含氯消毒剂和臭氧等化学品,容易产生有毒的副产物。紫外线消毒技术不使用化学试剂且不产生副产物,因此得到广泛应用。但是紫外线仅破坏致病微生物的遗传物质,阻断其繁殖,一些致病微生物能够修复紫外损伤恢复活性。光催化过程产生的羟基自由基不但能氧化分解DNA,还能破坏细胞膜并氧化流出的胞内物质,进而能彻底杀死微生物。由于紫外光和自由基同时参与灭菌,灭活速度也比紫外消毒快,因此具有较好的应用前景。本文综述了光催化产生的各种氧化性自由基的消毒原理,介绍了光催化剂分别与金属颗粒、纳米碳材料和微生物适配子构成的复合光催化消毒材料,在此基础上总结了薄膜反应器、固定床反应器和膜分离反应器在光催化消毒领域的研究进展。     

日本科学家研制成功全新紫外线监测器

<正>紫外线是电磁波谱中波长从10 nm到400 nm辐射的总称,不能引起人们的视觉。1801年德国物理学家里特发现在日光光谱的紫端外侧一段能够使含有溴化银的照相底片感光,因而发现了紫外线的存在。紫外线具有高能量,能够破坏、分解DNA,所以是人们的防范对象。自然界的主要紫外线光源是太阳,太阳光透过大气层时波长短于290 nm的紫外线为大气层中的臭氧吸收掉。因此,监测不同地区紫外线的强度可以获知当地臭氧层的状况。     

一种新型的糖基型紫外线吸收剂的合成和表征

<正>紫外线是太阳光谱中波长200～400nm部分的电磁波,约占太阳辐射的6%,按波长不同,又可分为UVC(短波紫外线,200～280nm)、UVB(中波红斑效应紫外线,280～320nm)、UVA(长波黑斑效应紫外线,320～400nm)3个区段,其中UVC几乎全部被大气层阻滞,对人体无法造成伤害。     

大分子紫外线吸收剂的制备及其在聚偏氟乙烯中的应用

通过原子转移自由基聚合(ATRP)方法,将反应型紫外线吸收剂2-羟基-4-(3-甲基丙烯酸酯基-2-羟基丙氧基)二苯甲酮(BPMA)与甲基丙烯酸甲酯(MMA)共聚合成紫外线吸收剂P(MMA-co-BPMA),然后共混涂膜制备出具有紫外线吸收性能的聚偏氟乙烯(PVDF)复合膜。 通过核磁共振谱(NMR)、凝胶渗透色谱(GPC)、差示扫描量热仪(DSC)等技术手段对BPMA及P(MMA-co-BPMA)的结构和性能进行表征,通过紫外-可见光谱(UV-Vis)对制备的复合膜的紫外线吸收性能进行表征。 结果表明,大分子紫外线吸收剂P(MMA-co-BPMA)相对分子量分布较窄,为1.11。 当BPMA质量分数为0.68%时,P(MMA-co-BPMA)/PVDF复合膜在200~345 nm范围内透过率可降至0.4%以下,能够实现对紫外线的完全吸收。 抽提实验表明紫外线吸收剂大分子化可有效地防止外迁移。     

工艺条件对稀土掺杂玻璃紫外线屏蔽性能的影响

研究了在玻璃中掺杂铈和钕对玻璃的紫外线屏蔽能力的影响,分析了其紫外线吸收的机制.结果表明,紫外线屏蔽能力与稀土元素添加量有明显的依赖关系,随着添加量的增加,紫外线的透过率均呈降低趋势,在同样添加量时,氧化钕比氧化铈的屏蔽能力强;随着保温时间的不同,含氧化铈玻璃的屏蔽能力有所不同,而含氧化钕的玻璃对保温时间不敏感.     

臭氧层为什么会破洞

臭氧层距地表约20—30km,那里聚集了大量的无色、活泼的气体-臭氧,我们便称之为臭氧层。臭氧会吸收太阳光里的紫外线,大量的紫外线会导致皮肤癌的发生;而这群臭氧尖兵阻挡了近98％的紫外线,只让那些对生物有益的光线照到地球上。     

3类高关注紫外线吸收剂的前处理与检测技术研究进展

紫外线吸收剂是一种具有强烈吸收紫外线作用的光稳定剂,会对生态环境以及人体健康造成危害,国内外许多国家已制定相关法规限制其使用。该文综述了近几年来国内外关于二苯甲酮类、三嗪类和苯并三唑类3类紫外线吸收剂检测的研究现状,分别对样品前处理与检测技术进行了详细介绍,并对其研究发展趋势进行了展望。     

加拿大推出能即时监测空气质量的可穿戴设备

<正>加拿大一新创公司推出了一款新型可穿戴设备,称为TZOA包围追踪器,可以即时监测人们周围的环境状况,如空气质量、紫外线强度等。据物理学家组织网不久前报道,在设计上,这种配置器可以直接检测环境中的空气污染和紫外线强度,TZOA通过蓝牙向智能手机发送并共享数据,i OS和安卓的App(应用程序)就会显示环境指标,指示空气污染和紫外线对用户     

紫外吸收试剂对反相液相色谱-间接紫外检测法分析烷基磺酸盐的影响

研究了不同背景紫外吸收试剂对无紫外光吸收的烷基磺酸盐检测的影响。采用反相C18色谱柱的高效液相色谱-间接紫外检测法,以背景紫外吸收试剂-有机溶剂为流动相分离烷基磺酸盐。研究不同背景紫外吸收试剂对分离检测烷基磺酸盐的影响规律和分离机理。结果表明,不同类型的背景紫外吸收试剂测定烷基磺酸盐的色谱峰类型不同。阳离子型背景紫外吸收试剂测定烷基磺酸盐时,样品峰均为正峰;阴离子型和两性离子型背景紫外吸收试剂时,样品峰均为倒峰。比较不同的背景紫外吸收试剂,发现采用阳离子型紫外吸收试剂测定烷基磺酸盐的色谱峰更好,其中以咪唑离子液体最佳,检测响应值最高。     

Effect of ultraviolet absorption reagent for determination of piperidinium ionic liquid cations by ion pair chromatography with indirect ultraviolet detection

Indirect ultraviolet detection method is a simple and effective method for the determination of ionic liquid cations without ultraviolet absorption group. This paper focused on the influence of different background ultraviolet absorption reagents on the determination of piperidinium ionic liquid cations by ion pair chromatography with indirect ultraviolet detection. Ultraviolet absorption reagents are divided into cationic (4-aminophenol hydrochloride, 1-ethyl-3-methylimidazolium tetrafluoroborate, and N-ethylpyridinium tetrafluoroborate), anionic (potassium biphthalate and 5-sulfosalicylic acid), and amphiprotic (p-aminobenzoic acid). The results showed that piperidinium cations can be separated and detected by cationic and anionic ultraviolet absorption reagents. In general, the cationic ultraviolet absorption reagents have the best effect for separation and detection of the piperidinium cations by ion pair chromatography with indirect ultraviolet detection.     

Measurement of solar ultraviolet radiation at a temperate and a tropical site using polysulphone film

Measurements of solar ultraviolet radiation (<320 nm) have been made with polysulphone film at a temperate and a tropical site and compared mean monthly values of the fraction of ultraviolet in solar radiation are calculated which allow an estimate of ultraviolet dose to be made from a knowledge of total solar radiation.While the data demonstrate the marked effect of sun elevation on the ultraviolet fraction of solar radiation they also indicate the effect of seasonal variation in the thickness of the ozone layer above the temperate site.It is also shown that whereas sunlight makes by far the major contribution to total solar radiation, skylight is of prime importance as regards ultraviolet radiation.     

Enhanced ultraviolet resistance of polypropylene random copolymer filled by ZnO-supported mesoporous zeolite

To enhance the ultraviolet resistance of ZnO based polymer materials, ZnO-supported mesoporous zeolite(M-ZnO) was prepared and characterized by atomic absorption spectroscopy and scanning electron microscopy. The ultraviolet resistance, crystallization behavior and melting characteristics of ZnO and M-ZnO filled PPR composites were compared by FTIR spectra and differential scanning calorimetry. The ultraviolet resistance of M-ZnO filled PPR composites is higher than that of ZnO filled PPR composites, indicating higher ultraviolet resistance of M-ZnO than that of ZnO. The crystallization temperatures of mesoporous zeolite filled PPR were higher than those of M-ZnO and decreased with increasing UV-irradiation time. But the crystallization temperatures of M-ZnO filled PPR composites were not influenced by UV-irradiation time. The ZnO supported on the surface of zeolite is effective in enhancing the ultraviolet resistance of ZnO based polymer materials.     

真空紫外灯单光子电离源飞行时间质谱仪的研制

研制了真空紫外灯单光子电离源飞行时间质谱仪(Vacuum ultraviolet single photon ionization time-offlight mass spectrometer,VUV-SPI-TOFMS),包括真空系统、毛细管进样系统、真空紫外灯电离源、垂直加速反射式飞行时间质量分析器和数据采集系统...     

Terpolymerization of sulfur dioxide or maleic anhydride with unsaturated compounds under ultraviolet irradiation

The effect of ultraviolet irradiation on the terpolymerization was investigated. In the terpolymerizations of sulfur dioxide–butene-1–acrylonitrile, sulfur dioxide–butene-1–n-butyl acrylate, and maleic anhydride–allyl chloride–acrylonitrile systems, the composition of the terpolymers prepared under ultraviolet irradiation was different from those prepared in the dark. The unit content of sulfur dioxide and butene-1 or of maleic anhydride and allyl chloride in the terpolymer increased under ultraviolet irradiation. The nature of the growing end under ultraviolet irradiation is supposed to be the same as that of the dark polymerization on the basis of the same solvent effect on the terpolymer composition, the rate of polymerization and the molecular weight of polymer. The experimental results suggest that the complex between sulfur dioxide and butene-1 or maleic anhydride and allyl chloride might be excited by ultraviolet light and the excited complex may participate in the terpolymerization.     

Effect of ultraviolet irradiation on terpolymerization of sulfur dioxide with two unsaturated compounds

The terpolymerization of sulfur dioxide, butene-1 and acrylonitrile affords terpolymers containing equimolar amounts of sulfur dioxide and butene-1 with various acrylonitrile contents. Ultraviolet irradiation was found to accelerate the polymerization and decrease the acrylonitrile content in the polymer. This fact is interpreted by a mechanism through a copolymerization of sulfur dioxide–butene-1 complex and acrylonitrile, whereby the polymerizability of sulfur dioxide–butene-1 complexed monomer may be accelerated by ultraviolet light. In fact, a binary system of sulfur dioxide and butene-1 was found to be accelerated by ultraviolet irradiation, and it affords a maximum rate at a 1:1 composition of feed monomer. Ultraviolet light of 250–300 mμ wavelength is effective for the initiation and the propagation. This may be ascribed to the ultraviolet absorption of the sulfur dioxide–butene-1 complex. The temperature coefficient was measured in both dark and ultraviolet irradiation reactions. The ultraviolet irradiation enhances the reactivity of sulfur dioxide–butene-1 complexed monomer at low temperature. In the terpolymerization with sulfur dioxide, isoprene, and butadiene, the ratio of isoprene and butadiene in the terpolymer was not altered by ultraviolet irradiation because both monomers from complexes with sulfur dioxide, perhaps having the same temperature coefficient for the polymerization.     

Application of Dielectric Barrier Discharge Reactor Immersed in Wastewater to the Oxidative Degradation of Organic Contaminant

Dielectric barrier discharge (DBD) is an effective method available for the production of ozone and ultraviolet light. The wastewater treatment system of this study was designed to utilize both ozone and ultraviolet light produced in the DBD reactor for the degradation of organic contaminant. The DBD reactor consisted of a quartz cylinder and a coaxial ceramic tube inside of which a steel rod was placed. The DBD reactor was immersed in the wastewater that was grounded. In this case, the wastewater acted not only as an electrode but also as the cooling medium for the DBD reactor. An azo dye, Acid Red 27, was used as the organic contaminant. In this system, the organic contaminant was degraded by two oxidation pathways induced by ozone and ultraviolet light. The concentration of ozone, the ultraviolet radiation intensity and the degradation efficiency of the organic contaminant were measured by varying the discharge. The results showed that the present system was very effective for the degradation of the organic contaminant. The energy requirement for the degradation was found to be 0.654 kJ/mg, which is much smaller value than those obtained with an ultraviolet/photocatalytic process.     

THE WAVELENGTH-DEPENDENT FRACTION OF BIOLOGICAL DAMAGE DUE TO THYMINE DIMERS AND TO OTHER TYPES OF LESION IN ULTRAVIOLET-IRRADIATED DNA

Abstract— The sensitivity of Hemophilus influenzae transforming DNA to monochromatic ultraviolet radiation has been determined with and without maximum photoreactivation. The fraction of ultraviolet damage which is photoreactivable (the photoreactivable sector) is large and varies with the wavelengths of the inactivating radiation, decreasing at the extremes of the ultraviolet spectrum. Equating photoreactivable damage with thymine dimer damage, we may interpret the wavelength dependence of photoreactivability and the spectrum for non-photo-reactivable damage in terms of the absorption spectra of thymidine and cytosine deoxyriboside. The data suggest that cytosine deoxyriboside alteration is important in non-photoreactivable biological damage.