光活化杀虫剂的发展历史及光活毒性机制

所谓光活化杀虫剂 (light activatedinsecticides)即为在无光照条件下对害虫无活性或活性很低 ,但在日光或特定波长的人工光 (尤其是近紫外光 )照射下杀虫活性大幅度增加的一类物质。这类杀虫剂有望成为传统化学杀虫剂的替代物。众所周知 ,传统的化学杀虫剂引起了许多重要的问题 ,包括对动植物特别是人类的毒性 ,以及在环境中的长期残留造成的严重污染。光活化杀虫剂在可见光照射下迅速失活 ,加上它们在黑暗条件下缺乏明显的毒性 ,因而减少了它们对环境产生重要影响的风险。所以 ,从安全和环境方面考虑 ,人们对光活化杀虫剂产生了浓厚的兴趣…     

红光响应溶菌酶PLGA纳米囊的制备与表征

以聚乳酸-羟基乙酸共聚物(PLGA)为囊材,添加脱镁叶绿酸,采用复乳法制备红光响应溶菌酶纳米囊。以包封率、载药量和纳米囊粒径为指标优化配方,对其结构、热流变性和光控释测定。获得优化的PLGA、溶菌酶及脱镁叶绿酸用量配比为55:10:1,纳米囊包封率为81.3%±4.5%,载药量为13.1%±1.6%,平均粒径为(667±35)nm,电位(-39.6±4.6)m V。纳米囊呈紧密球形,光敏剂分布在囊壳,650 nm光照30 min药物释放明显加快。此新型纳米囊在不光照时具有增强药物稳定和缓释作用,而红光可促进释药,因而可实现光控靶向。     

真空脱氯系统中存在的问题及解决办法

2005年12月，平煤集团开封东大化工有限公司（以下简称“开封东大公司”）离子膜烧碱产能达到4万t／a。2006年1月，脱氯工艺由空气吹除法改为真空脱氯法。脱氯目的：电解工段出槽的淡盐水被阳极液产生的氯气饱和，淡盐水质量浓度为200g／L，电解槽阳极液未加酸，pH值在4．00—4．25，游离氯质量浓度为1．9—2．2mg／L。     

红光响应眼镜蛇神经毒素PEG-PLGA纳米囊的制备与表征

以聚乙二醇-聚乳酸-聚乙醇酸嵌段共聚物(PEG-PLGA)为囊材,添加脱镁叶绿酸作为光敏剂,采用复乳法制备了光响应的眼镜蛇神经毒素纳米囊。以纳米囊的包封率、载药量和粒径为指标,采用单因素法对纳米囊的制备条件进行优化;以差示量热扫描分析其热流变性能,并以累积释药量研究其光控释行为。优化的PEGPLGA、眼镜蛇神经毒素及光敏剂脱镁叶绿酸质量配比为40∶12.5∶1,获得的纳米囊包封率为72.3%±3.6%,载药量为15.1%±1.3%,平均粒径为(862±23)nm,电位为(-46.5±3.8)m V,呈紧密球形,光敏剂分布在囊壳;在650 nm半导体激光照射30 min,体外释放明显加快。该纳米囊在不光照时具有增强药物稳定和缓释作用,而红光可促进药物释放,因而可实现光控靶向。     

芦根复方提取液体外3T3中性红摄取光毒性试验研究

通过乙醇提取方法,以芦根、甘草、当归、丹参、山茱萸及地骨皮为组方,制备芦根复方提取液,生药质量浓度为0.05 g/m L。采用体外3T3中性红摄取试验,评估制备的芦根复方提取液潜在的光毒性。比较3T3中性红摄取试验中受试样品和阳性对照盐酸氯丙嗪(CPZ)在无光照及光照条件下对Balb/c 3T3细胞的IC_(50)值、光刺激因子(PIF)和平均光效应(MPE),以此评价样品预期产生光毒性的可能。结果显示,阳性对照品CPZ存在明显光毒性,而芦根复方提取液样品预期无光毒性。     

当归复方提取液体外3T3中性红摄取光毒性试验研究

以当归、三七、黄芪、女贞子、甘草按一定质量比形成复方,采用水提煎煮法,制备当归复方提取液,生药质量浓度为0.05 g/m L。采用体外3T3中性红摄取试验,评估制备的当归复方提取液潜在的光毒性。比较3T3中性红摄取试验中受试样品和阳性对照盐酸氯丙嗪(CPZ)在无光照及光照条件下对Balb/c 3T3细胞的IC_(50)值、光刺激因子(PIF)和平均光效应(MPE),以此评价样品预期产生光毒性的可能。结果显示,阳性对照品CPZ存在明显光毒性,而当归复方提取液样品预期无光毒性。     

光响应茶皂苷元纳米囊的制备及其抗耐药菌活性研究

为了提高茶皂苷元的稳定性和抗耐药菌活性,采用复乳法制备光响应茶皂苷元纳米囊。以大豆卵磷脂、胆固醇和脱镁叶绿酸(质量比为50:10:1)为囊材,制得茶皂苷元纳米囊的包封率、载药量、平均粒径、Zeta电位分别为:87.3%±4.6%、13.5%±1.2%、(155±5)nm、(-43.3±2.0)m V。该纳米囊在无光照下具有缓释作用,而在650 nm光照下可加速释放。对耐药金黄色葡萄球菌和大肠杆菌的50%抑菌浓度分别是52.5和85.4μg?m L-1,而与庆大霉素(10μg?m L-1)联合用药时,降至22.6和45.7μg?m L-1,表明它可降低并逆转细菌对庆大霉素的耐药性。分子对接显示茶皂苷元和细菌的甘露醇脱氢酶和黏肽合成酶有显著相互作用,与其抗耐药菌机制相关。     

氟吗啉对家蚕的毒性和安全性评价

研究了氟吗啉对家蚕的胃毒、触杀、熏蒸毒性，并进行安全性评价。试验结果表明：氟吗啉对家蚕2龄起蚕胃毒毒性的LC50为10548．4mg／L；对家蚕触杀毒性的结果为10000．0mg/L浓度以下对2龄起蚕没有毒性作用；对家蚕熏蒸毒性的结果为10000．0mg／L浓度以下对2龄起蚕没有毒性作用。与氟吗啉的推荐使用剂量100-200mg/kg相比，氟吗啉对家蚕安全，对家蚕毒性为“低毒”。     

生物质再燃焦管道喷射脱汞性能

采用高温携带流反应装置在1050℃和1150℃条件下制备了稻壳再燃焦（RH1050和RH1150）和小麦秸秆再燃焦（WS1050和WS1150），并分别将其与燃煤灼烧飞灰混合制成相应的脱汞吸附剂。在吸附剂管道喷射脱汞实验装置上，研究了生物质种类、吸附温度、初始汞浓度和烟气组分（SO₂、NO和HCl）对生物质再燃焦管道喷射脱汞性能的影响，并结合生物质及其再燃焦的理化特性分析，探讨了单质汞（Hg⁰）脱除机理。结果表明：4种生物质再燃焦平均脱汞效率相差不大，约为30%，稻壳再燃焦的脱汞效率略高于小麦秸秆焦。随着吸附温度的升高，RH1050脱汞效率持续增加，RH1150脱汞效率则呈现波动变化趋势。随着初始汞浓度的升高，稻壳再燃焦的平均脱汞效率均呈现先增大后减小的趋势，初始汞浓度为25μg/m³时RH1050和RH1150的平均脱汞效率最大，分别为35.6%和37.1%。SO₂对生物质再燃焦管道喷射脱汞具有一定的抑制作用，NO具有一定促进作用，而HCl的促进作用更为显著，且当HCl浓度大于50μL/L时，生物质再燃焦的平均脱汞效率均在90%以上。     

杨木粉酶水解工艺条件的研究

研究了杨木粉酶水解的工艺条件。实验结果表明丙酸处理杨木粉的最优条件为：900g／L的丙酸，3g／L的盐酸，121℃蒸解90min；处理过的杨木粉用纤维素酶水解，酶解温度50℃、底物浓度50g／L、每100g底物加酶1．00mL、水解时间72h，葡萄糖浓度可达22.5g／L。     

EP/苯酚-苯胺型单环苯并噁嗪树脂共聚体系研究

采用无溶剂法合成了苯酚-苯胺型单环苯并噁嗪树脂(P-a),然后将其与环氧树脂(EP)进行共聚,并采用差示扫描量热(DSC)法对该共聚体系的固化特性进行了研究。结果表明:不同P-a/EP质量比的复合材料体系,其冲击强度由纯EP体系的16.12 kJ/m2分别降至14.51 kJ/m2(质量比10%)、13.90 kJ/m2(质量比30%)和14.15 kJ/m2(质量比50%);纯EP体系的弯曲强度和弯曲模量分别为100.56 MPa和3.46 GPa,而P-a/EP体系的最大弯曲强度和弯曲模量分别为110.26 MPa和3.84 GPa;EP/P-a体系含氮量最高为3.52%,但各组试样均燃尽,说明单纯增加树脂体系的氮含量并不能有效提高其垂直燃烧性能。     

Synthesis of cardanol-based phthalonitrile monomer and its copolymerization with phenol–aniline-based benzoxazine

The cardanol-based phthalonitrile (PN) monomer was successfully produced via the nucleophilic substitution reaction of cardanol with 4-nitrophthalonitrile in potassium carbonate media. The conventional methods were employed to predict the chemical structure. The influence of long alkyl chains of cardanol was observed on the thermomechanical properties, recorded values were much below than the poly(Baph) standards. However, the thermal stabilities were recorded in good agreement to PN resin values. Furthermore, the 100 kGy dose of Co⁶⁰ irradiation does not show any remarkable changes in the studied properties. The copolymers from P-a benzoxazine and cardanol-based PN (CPN) on the different wt % blending were prepared. The curing behavior and mechanism of the monomer blends were analyzed. The curing of CPN was improved in the presence of active hydrogen produced from the P-a polymerization. The T _g and thermal properties of the copolymer were much better than the neat poly(P-a). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47505.     

Trifunctional quinoxaline-based maleimide and its polymer alloys with benzoxazine: Synthesis,characterization, and properties

Novel quinoxaline-based trismaleimide (2,3-di[3-maleimido]phenyl-6- maleimidoquinoxaline, namely TQMI) and its polymer alloys with 3-phenyl-3,4-dihydro-2H-1,3-benzoxazine (P-a) were successfully prepared and characterized. Differential scanning calorimetry investigation of TQMI exhibited distinct double exothermic peaks, which implied that the curing behavior of different type of maleimide group was discrepant. The curing temperature of P-a/TQMI prepolymers was lower than that of both neat TQMI and P-a monomer. The temperatures at 5% (T₅) and 10% (T₁₀) weight loss and the char yield (Y_c) of cured TQMI at 800°C reached 513°C, 524°C, and 63.5%, respectively, which were much higher than the record of traditional 4,4′-bismaleimideodiphenylmethane (BMDPM) resin as well as most of other reported bismaleimide resins. Moreover, the addition of TQMI enhanced thermal stability, glass transition temperature (T_g), and limiting oxygen index of benzoxazine resin dramatically. Attractively, the T_g value of P-a/TQMI copolymer at 30 wt% TQMI loadings was approximately 20°C higher than that of P-a/BMDPM copolymer owing to the bulky quinoxaline group.     

Studies on high density polyethylene (HDPE) functionalized by ultraviolet irradiation and its application

The structure and properties of high density polyethylene (HDPE) functionalized by ultraviolet irradiation at different light intensities in air were studied by electron analysis, FTIR spectroscopy, contact angle with water, differential scanning calorimetry and mechanical properties measurement. The results show that oxygen‐containing groups such as C?O, C—O and C(?O)O were introduced onto the molecular chain of HDPE following irradiation, and the rate and efficiency of HDPE functionalization increased with enhancement of irradiation intensity. After irradiation, the melting temperature, contact angle with water and notched impact strength of HDPE decreased, the degree of crystallinity increased, and their variation amplitude increased with irradiation intensity. Compared with HDPE, the yield strength of HDPE irradiated at lower light intensity (32 W m^?2 and 45 W m^?2) increases monotonically with irradiation time, and the yield strength of HDPE irradiated at higher light intensity (78 W m^?2) increases up to 48 h and then decreased with further increase in irradiation time. The irradiated HDPE behaved as a compatibilizer in HDPE/polycarbonate (PC) blends, and the interface bonding between HDPE and PC was ameliorated. After adding 20 wt% HDPE irradiated at 78 W m^?2 irradiation intensity for 24 h to HDPE/PC blends, the tensile yield strength and notched Izod impact strength of the blend were increased from 26.3 MPa and 51 J m^?1 to 30.2 MPa and 158 J m^?1, respectively. Copyright © 2003 Society of Chemical Industry     

Modeling of an external light irradiation slurry photoreactor: UV light or sunlight-photoassisted Fenton discoloration of azo-dye Orange II with natural mineral tourmaline powder

A model for design and scale-up of an external light irradiation slurry photoreactor was developed on the basis of a model for the average light intensity in the photoreactor. In order to assess the design parameters in the proposed model, experiments for UV light or sunlight-photoassisted Fenton discoloration of azo-dye Orange II in water with iron ion eluted from the natural mineral tourmaline powder containing 4.49 wt% Fe₂O₃ were conducted using an external light irradiation cylindrical column photoreactor. The efficiency of discoloration increased as initial Orange II concentration decreased and the tourmaline concentration and UV light intensity increased. It was found that the optimal hydrogen peroxide concentration and pH are and 3, respectively. The proposed model, in which the change of light intensity with degradation time due to the discoloration of Orange II and the light scatter due to solid photocatalysts are taken into account, could simulate the experimental results both for UV light and sunlight irradiation conditions reasonably well. The model is applicable commonly both for UV light and sunlight irradiation. The results will be very useful for designing slurry photoreactors in the treatment of textile effluents.     

紫外线对给水除藻作用的研究

以武汉东湖水为原水,采用不同的光强和照射时间组合,对原水进行紫外光预处理来加强除藻效果,后续工艺为栅条絮凝、气浮。试验结果表明:2.8mW/cm2照射1.5min可达到83.5%的除藻率,2.5mW/cm2照射6min除藻率为87.6%。光强和时间对藻的抑制存在交互作用,增大光强可提高除藻率,但当光强小幅增大时,随着照射时间的延长会出现小剂量效应。针对试验期间的原水,2.5mW/cm2照射6min的效果最好。经过紫外线预处理后,水的浊度略有升高,溶解氧减少,pH值降低,CODMn降低。     

TiO2混晶负载磷钨酸借自然光照对甲基橙的脱色性能研究

研究了以TiO2混晶负载磷钨酸为光催化剂,在光照条件下模拟染料废水甲基橙溶液的光催化脱色性能。实验结果表明:催化剂的投入量,甲基橙的初始浓度,光照时间是影响甲基橙溶液脱色率的重要因素。当H3PW12O40/TiO2催化剂用量为1.5 g/L,甲基橙的初始浓度为10 mg/L,光照时间为2.5 h时,甲基橙溶液的脱色率可达97.9%。     

侧光光纤引导的内源可见光催化降解亚甲基蓝(英文)

The side-glowing optical fibers (SOFs) were chosen as the conducting medium of endogenous light; and 20 mg·L-1 methylene blue was chosen as the target to be degraded. The SOF is made up of quartz core with a silicon cladding, which can emit light through side surface more uniformly and transmit light for longer distance to avoid attenuation of light by liquid medium. The filament lamp was chosen as visible light source. Different reaction conditions, such as the presence of optical fiber or not, the quantity of SOF, light irradiation intensity were tested by measuring the methylene blue degradation of methylene blue. The results show that suitable reaction conditions were 1.167 g·L-1 Ag + /TiO 2 with 7% (by mass) of Ag + doped in TiO 2 , and 500 roots of SOF (30 cm length in solution). The photocatalytic degradation efficiency under 300W lamp irradiation for 8h was about 97%. And the photocatalytic degradation efficiency of methylene blue degradation was proportional to SOF quantity, light irradiation intensity and catalytic dosage within a certain range. Compared with general UV and visible light SOFs could save a huge amount of energy and cost, in the potential applications in dealing with organic pollutants on a large scale.     

Spectrofluorometric analysis and electrical conductivities of styrene and methyl methacrylate polymers

Conductive polymers were obtained by using a new polymerization method where UV‐light was used as a photochemical initiator. To obtain high molecular weights, optimum irradiation times were determined. The luminescence properties of polymers have been found to be useful for their identification. The use of luminescence spectroscopy as an analytical technique for polymer identification involves the measurement of fluorescence emission spectrum, which is obtained by exciting the polymer with UV‐radiation. Fluorescence emission spectra of polystyrene (PS) and polymethyl methacrylate (PMMA) samples were taken at room temperature at excitation wavelengths at 290 nm and 292 nm, respectively. PPMA was prepared with different molecular weights, and the intensity of the fluorescence emission was correlated with polymer chain length. Conductivity versus molecular weight relation was established for each polymer. The plots obtained between conductivities and molecular weights can be used as a calibration curve. From the plot of emission intensity against polymer molecular weights, the molecular weights of unknown polymeric samples can be determined. The most efficient irradiation times were determined by using conductivity versus irradiation time plots. Conductivity versus temperature change of the polymeric samples at different temperatures was determined. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Photocatalytic activity of AgBr/TiO2 in water under simulated sunlight irradiation

In this paper, the synthesis of AgBr/TiO₂ catalyst and the photocatalytic activity in water under simulated sunlight irradiation were studied. The influence of AgBr content in catalyst and the incident light intensity on the degradation of methyl orange (MO) was investigated. It was found that the initial reaction rate constant was dependent on the relative levels of AgBr content and incident light intensity, ranging between 0.008 min⁻¹ and 0.023 min⁻¹. At higher levels of AgBr content (>9 wt%), MO degradation was exclusively dependent on the incident light intensity, which implied that the excessive AgBr in catalyst had negligible effect on catalyst activity. However, at lower AgBr contents, the reaction rate increased with the increase of incident light intensity, and eventually reached a plateau level, indicating that the degradation of MO was limited by AgBr content. The results from powder X-ray diffraction (XRD) analysis showed that more than 80% of AgBr remained intact after 14 h of irradiation, although metallic silver was also detected.