光化法合成液体端羟基聚异戊二烯

通过光化法合成端羟基聚异戊二烯 (HTPI) ,考察了溶剂的种类、聚合反应时间、引发剂过氧化氢用量、单体浓度、光敏剂种类及用量等因素对聚合物的相对分子质量、分子量分布、平均官能度及转化率的影响。实验表明 ,光化法合成HTPI较合适的反应条件为 :用乙醇作溶剂 ,过氧化氢质量体积浓度 30～ 50g/L ,单体浓度 3.5～ 4 .0mol/L ,温度 ( 30± 2 )℃、反应时间 11h。产物的相对分子质量可达 950～ 10 0 0 ,分子量分布分散系数约为 1.2 ,平均官能度为 2 .0左右。添加光敏剂可提高单体转化率 ,浓度以 0 .3mol/L为宜。转化率最高可达 75%。

二步光氯化悬浮法制备高氯含量的氯化等规聚丙烯

采用二步光氯化悬浮法制备了高氯含量的 CIPP,研究了氯化温度、通氯量、固液比以及光照时间和方式等对 CIPP含氯量的影响。制备了含氯量在 61 %～ 63 %的高氯 CIPP,筛选出滤波介质并解决了光氯化法生产高聚物时灯易结膜的技术难点。得出的最佳工艺条件是 :在第一阶段 m( PP)∶ m(氯苯 ) =1∶ ( 8.5～ 9) ,反应温度 ( 1 1 0± 2 )℃ ,光照 5h,通氯速率为 4 0 cm3/min;第二阶段 m ( CPP)∶ m ( CCl4 )∶ m ( H2 O) =1∶ 3∶ 1 0 ,反应温度 70～ 75℃ ,光照反应时间 6～ 8h,通氯速率为 4 0cm3/min。

甲状腺功能五项指标联合检测法对孕妇甲状腺功能的评估意义

研究分析孕妇甲状腺功能评估采用电化学化光法甲状腺五项联合检测法的实施作用及临床应用价值。方法 2022年1月至2022年12月,健康体检行甲状腺功能检验孕妇1252例,采用电化学化光法甲状腺五项联合检测法进行检查,检查作用开展分析。结果 检验后阳性甲状腺数统计,检出阳性甲状腺数110例,检出率8.78%。对检出阳性甲状腺孕妇甲状腺功能评估准确率、灵敏度等进行计算,对比可见,甲状腺功能亢进、甲状腺功能减退者甲状腺功能评估准确率、灵敏度均较高,无统计学差异(P>0.05),对孕妇甲状腺功能指标进行比对,比较数据可见甲状腺功能亢进、甲状腺功能减退者与甲状腺功能正常者指标各项数据均具备明显差异性(P<0.05)。结论 评估孕妇甲状腺功能,甲状腺功能五项指标联合检测的实施,能够在甲状腺功能异常孕妇做到有效检出及准确评估。

大直径射流的放电特性及其等离子体参数和活性粒子分布的光谱诊断

大气压等离子体射流因其产生的等离子体羽富含活性粒子而在废水净化、元素探测、材料处理等方面具有良好的应用前景。通常等离子体羽的直径较小,限制了其工作效率。针对于此,利用交流电压激励大气压氩气等离子体射流,产生了直径约为14 mm的大尺度均匀等离子体羽。采用发射光谱法对电子密度和氧原子浓度随不同实验参数的变化关系进行了研究。光电测量结果表明,当外加电压峰值或氩气流量增加时,等离子体羽发光亮度增加。当电压峰值较低时,等离子体羽的上下游在电压的每个周期均有两个光脉冲信号,且上游光信号强度比下游的大。随着电压峰值增大,上下游等离子体羽的光信号强度都增大。当电压峰值较高时,上下游等离子体羽的光信号在每个电压周期呈现三个放电脉冲。不论每个电压周期放电脉冲数目多少,上下游等离子体羽的发光信号均具有同步性。利用光谱仪采集了300~800 nm范围内上下游等离子体羽的发射光谱,发现它们中均含有OH和N 2的谱线及ArⅠ和OⅠ谱线。其中,上游等离子体羽的ArⅠ谱线强度比下游的大,但OH和N 2的谱线强度比下游的小。利用谱线强度比对上、下游等离子体羽的电子密度进行了研究。结果表明,上游等离子体羽的电子密度在10^(14) cm^(-3)量级,高于下游羽的电子密度(10^(13)~10^(14) cm^(-3)量级)。并且,上游和下游等离子体羽的电子密度均随外加电压峰值的升高而增加,随氩气流量的增加而增加。利用光化线强度法,研究了下游羽中氧原子浓度随实验参数的变化规律。结果表明,氧原子浓度沿气流方向降低;对于一个等离子体羽,平均而言氧原子浓度随外加电压峰值升高而增加,随氩气流量增加而增加。对于以上实验现象,利用气体放电的基本理论进行了定性解释。

Enhanced Photocatalytic Performance of Anatase TiO_(2) by Deposition-Precipitation Treatment

Deposition-precipitation(DP)method is commonly used to prepare the supported metal catalysts.In this study,the modification effect of the mild DP method on the photocatalytic performance of TiO_(2)was investigated.The TiO_(2)samples with DP treatment,as well as Au/TiO_(2)prepared under the same conditions,showed enhanced photocatalytic performance of the degradation of methylene blue(MB).·OH generated by photoexcited holes is identified as the main intermediate reactive species during the degradation reaction.X-ray photoelectron spectroscopy(XPS)and Fourier transform infrared spectroscopy(FTIR)show that TiO_(2)(A)-17 after DP treatment has the most amount of surface OH^(-)_(ad)species.The presence of surface OH^(-)_(ad)species not only changes the surface zeta potential,favoring the attraction of cationic MB;but also depresses the electron-hole recombination,favoring photodegradation of MB by hole-produced·OH.An implication of these findings is that the modification of support properties should be taken into account while preparing supported metal catalysts using DP methods.

Fabrication of a monoclinic/hexagonal junction in WO_3 and its enhanced photocatalytic degradation of rhodamine B

A series of WO3 samples with different crystalline phases were prepared by the thermal decomposition method from ammonium tungstate hydrate.X-ray diffraction（XRD）,scanning electron microscopy（SEM）,high-resolution transmission electron microscopy（HRTEM）,X-ray photoelectron spectroscopy,and N2 adsorption-desorption were used to characterize the crystalline phase,morphology,particle size,chemical composition,and surface area of the WO3 samples.The formation of hexagonal（h-WO3） and monoclinic（m-WO3） crystal structures of WO3 at different temperatures or different times was confirmed by XRD.m-WO3 is formed at 600 ℃,while m-WO3 starts to transform into h-WO3 at 800℃.However,h-WO3,which forms at 800℃,may transform into m-WO3 by increasing the calcination temperature to 1000℃.SEM results indicate that m-WO3 particles exhibit a bulky shape with heavy aggregates,while h-WO3 particles exhibit a rod-like shape.Moreover,m-WO3 crystals are sporadically patched on the surface of the h-WO3 rod-like particles,resulting in the exposure of both m-WO3 and h-WO3 on the surface.It is observed that the monoclinic phase（m-WO3）/hexagonal phase（h-WO3） junction was fabricated by tuning the calcination temperature and calcination time.The relative ratios between m-WO3 and h-WO3 in the phase junction can readily be tailored by control of the calcination time.The photocatalytic activities of WO3 with different crystalline phases were evaluated by the photocatalytic degradation of rhodamine B as a model pollutant.A higher photocatalytic activity was observed in the WO3 sample with the m-WO3/h-WO3junction as compared with the sample with only m-WO3.The improvement of photocatalytic activity can be attributed to the reduction of the electron-hole recombination rate owing to the formation of the phase junction,whose presence has been confirmed by HRTEM and photoluminescence spectra.

Fabrication and photodegradation properties of TiO_2 nanotubes on porous Ti by anodization

Both Ti foil and porous Ti were anodized in 0.5%HF and in ethylene glycol electrolyte containing 0.5%NH4F(mass fraction) separately. The results show that TiO2 nanotubes can be formed on Ti foil by both processes, whereas TiO2 nanotubes can be formed on porous Ti only in the second process. The overhigh current density led to the failure of the formation nanotubes on porous Ti in 0.5%HF electrolyte. TiO2 nanotubes were characterized by SEM and XRD. TiO2 nanotubes on porous Ti were thinner than those on Ti foil. Anatase was formed when TiO2 nanotubes were annealed at 400 °C and fully turned into rutile at 700 °C. To obtain good photodegradation, the optimal heat treatment temperature of TiO2 nanotubes was 450 °C. The porosity of the substrates influenced photodegradation properties. TiO2 nanotubes on porous Ti with 60% porosity had the best photodegradation.

磺基氯酚偶氮罗丹宁应用于贵金属分析

1.引言罗丹宁类化合物(硫代罗丹宁、乙内酰硫脲、假乙内酰硫脲、3-氨基罗丹宁、硒代罗丹宁、硫代丙酰罗丹宁等)与芳香胺(含成盐基、羟基)的重氮盐进行偶合反应,可制得一系列5-偶氮罗丹宁的化合物,其中适用于贵金属分析的是磺基氯酚偶氮罗丹宁(CXΦAP):

Determination the Vigor of Rice Seed with Different Degrees of Aging with Ultraweak Chemiluminescence During Early Imbibition

用高灵敏度的单光子计数系统探测人工老化 (40℃ ,相对湿度 90 % ) 0、7、14和 2 1d的水稻种子吸胀初期的超弱化学发光强度变化 ,首次观测到水稻 (OryzasativaL .)种子吸胀初期超弱化学发光强度与其老化程度有关。加水激活水稻种子的超弱化学发光 ,其强度依赖于种子的老化程度。实验结果表明水稻种子的人工老化时间越短 ,则吸胀初期 (2 0～ 30min)超弱化学发光的强度越强 ,萌发率越高。水稻种子萌发率与超弱化学发光强度呈显著正相关。观测水稻种子吸胀初期超弱化学发光强度的变化可望成为检测种子老化程度的一种快速、简便、无损伤的新方法。

Field Measurement of NO2 and RNO2 by Two-Channel Thermal Dissociation Cavity Ring Down Spectrometer

A two-channel thermal dissociation cavity ring down spectroscopy （CRDS） instrument has been built for in situ, real-time measurement of NO2 and total RNO2 （peroxy nitrates and alkyl nitrates） in ambient air, with a NO2 detection limit of 0.10 ppbv at 1 s. A 6-day long measurement was conducted at urban site of Hefei by using the CRDS instrument with a time resolution of 3 s. A commercial molybdenum converted chemiluminescence （Mo-CL） instrument was also used for comparison. The average RNO2 concentration in the 6 days was measured to be 1.94 ppbv. The Mo-CL instrument overestimated the NO2 concentration by a bias of ＋1.69 ppbv in average, for the reason that it cannot distinguish RNO2 from NO2. The relative bias could be over 100% during the afternoon hours when NO2 was low but RNO2 was high.

Spectrophotometric Determination of Lodine in Soils by Chloramine T-Tetrabase System

Optimized the experimental conditions of determination of trace iodine in soil in chloramine T-Tetrabase system, and analysis the national standards material, the results showed that the measured values was to be identical with recommended values with a detection limit of 0.16 μg/g, and the relative standard deviation was less than 8%, the whole process was short in time and simple, so it was applicable to the determination of trace iodine in batches.

Hydrophilic and photocatalytic activities of Nd-doped titanium dioxide thin films

The Nd-doped TiO2 thin films with higher hydrophilic and photocatalytic activities were prepared on glass slides by an acid-catalyzed sol？gel method. The effects of Nd doping on crystalline phase, surface composition and optical property were investigated by means of techniques such as X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, Fourier transform infrared spectroscopy （FT-IR）, optical contact angle tester and UV-Vis spectroscopy. The results show that Nd doping obviously influences the hydrophilic and photocatalytic activities of TiO2thin films. Nd doping could cause the TiO2 lattice distortion, inhibit phase transition from anatase to rutile, cause red shift of the absorption spectrum edge, produce hydroxyl radicals （·OH）, and accelerate surface hydroxylation, which result in a significant improvement in the hydrophilicity and photoreactivity of Nd-doped TiO2 thin films. When the content of Nd is 0.1% （mass fraction）, TiO2 thin films achieve the smallest grain size （about 15 nm）, and the hydrophilic and photocatalytic activities of TiO2 thin film reach the maximum, the contact angle is only 8.1°, and 92% of methylene blue is finally degraded. Moreover, the modification mechanism of Nd doping was also discussed.

Sulfurization synthesis and photocatalytic activity of oxysulfide La_3NbS_2O_5

The oxysulfide La3NbS2O5 was synthesized by sulfurization using H2S and characterized by X-ray diffraction （XRD）, UV-Vis diffuse reflectance spectroscopy （DRS） and field emission scanning electron microscopy （FE-SEM）. The relationship between the sulfurization conditions and the photocatalytic activities for H2 evolution was investigated. Sulfurization method allowed for synthesis of La3NbS2O5 at much lower temperatures and significantly shortened reaction time of 1 h compared with conventional solid-state techniques. The particle morphologies were regular platelike with sizes of 0.1-0.6μm and smooth surfaces. The highest activity for H2 evolution was obtained at 1073 K for 1 h, which was about 1.83 times that of La3NbS2O5 prepared by solid-state method.

Preparation, Characterization and Photocatalytic Activity of Fe, La Co-doped Nanometer Titanium Dioxide Photocatalysts

A series of photocatalysts of un-doped, single-doped and co-doped nanometer titanium diox- ide （TiO2） have been successfully prepared by template method using Fe（NO3）3.9H2O, La（NO3）3.6H2O, and tetrabutyl titanate as precursors and glucan as template. Scanning electron microscopy, X-ray diffraction, and N2 adsorption-desorption measurement were employed to characterize the morphology, crystal structure and surface structure of the samples. The photo-absorbance of the obtained catalysts was measured by UV-Vis absorption spectroscopy, and the photocatalytic activities of the prepared samples under UV and visible light were estimated by measuring the degradation rate of methyl orange in an aqueous solution. The characterizations indicated that the prepared photocatalysts consisted of anatase phase and possessed high surface area of ca. 163-176 m2/g. It was shown that the Fe and La co-doped nano-TiO2 could be activated by visible light and could thus be used as an effective catalyst in photo-oxidation reactions. The synergistic effect of Fe and La co-doping played an important role in improving the photocatalytic activity. In addition, the possibility of cyclic usage of co-doped nano-TiO2 was also confirmed, the photocatalytic activity of codoped nano-TiO2 remained above 89.6% of the fresh sample after being used four times.

Preparation, Characterization, Photocatalytic Activity of S and Ag co-Doped Mesoporous Titania Photocatalysts

In order to improve the photocatalytic performance of mesoporous titania under visible light, a series of photocatalysts of S and Ag co-doped mesoporous titania have been successfully prepared by template method using thiourea, AgNO3 and tetrabutyl titanate as precursors and Pluronic P123 （EO20PO70EO20） as template. Scanning electron microscopy （SEM）, X-ray diffraction （XRD）, nitrogen adsorption-desorption measurements, and UV-visible spectroscopy （UV-Vis） were employed to characterize the morphology, crystal structure, surface structure, and optical absorption properties of the samples. The microcrystal of the photocatalysts consisted of anatase phase and was approximately present in the form of spherical particle. The photocatalytic performance was studied by photodegradation methyl orange （MO） in water under UV and visible light irradiation. The calcination temperature and the doping content influenced the photoactivity. In addition, the possibility of cyclic usage of co-doped mesoporous titania was also confirmed, the photocatalytic activity of mesoporous titania remained above 89% of that of the fresh sample after being used four times. It was shown that the co-doped mesoporous titania could be activated by visible light and could thus be potentially applied for the treatment of water contaminated by organic pollutants. The synergistic effect of sulfur and silver co-doping played an important role in improving the photocatalytic activity.

Preparation and photocatalytic activity of neodymium doping titania loaded to silicon dioxide

Neodymium doping titania was loaded to silicon dioxide to prepare Nd/TiO2-SiO2 by sol-gel method and Nd/TiO2-SiO2 was characterized by X-ray diffractometry （XRD）, scanning electron microscopy （SEM）, Fourier transform-infrared spectroscopy （FT-IR） and diffuse reflectance spectra （DRS）. Photocatalytic activities of Nd/TiO2-SiO2 with different neodymium contents were evaluated by degradation of methyl orange. The light absorption of Nd/TiO2-SiO2 increased with increasing doping neodymium in a visible light range of 388-619 nm, and Nd doping was in favor of decreasing the recombination of photo-generated electrons with holes. Nd and SiO2 improved the photocatalytic activity of TiO2. The optimal molar fraction of Nd to Ti was 0.1%, and the optimum calcination temperature was 600 ℃. The highest degradation rate of methyl orange was 82.9% after irradiation for 1 h.

Determination of Total Flavones Content in Ceratocarpus arenarius L. by Spectrophotometry

[Objective] The aim was to establish the method for determining total flavoens content in Ceratocarpus arenarius L.[Method ] Flavonoids were extracted from C. arenarius by heating refluxing, and determined with rutin as the standard.[Result] In the range of 0.019-0.102 mg/ml, linear relationship was good （r=0.999 1）. This method had higher precision and accuracy with RSD of 0.226% and recoveries of 99.36%. The total flavones content from C. arenarius was 10.12 mg/g. [Conclusion] The method is simple and reliable, which could be used to control the quality of C. arenariu.

Research on Activity and Expression of Tyrosinase in Varicorhinus macrolepis

[Objective] This study aimed to analyze tyrosinase activity and its expression in Varicorhinus macrolepis. [Method] V. macrolepis was used as experimental material for the analysis and research of tyrosinase in nine kinds of organs and tissues of male and female V. macrolepis individuals by using polyacrylamide gel electrophoresis and biochemical staining method, spectrophotometry and enzyme histochemical technology. [Result] Tyrosinase exists in the liver and pancreas, intestine and spleen of female and male V. macrolepis and in the gallbladder of male V. macrolepis. Tyrosinase activities in various tissues of V. macrolepis varied largely. Specifically, tyrosinase activities in the spleen was the maximum, which was higher in female V. macrolepis than in males. According to the enzyme histochemistry results, strong positive signals of tyrosinase existed in the spleen, intestine, liver and pancreas and gallbladder of V. macrolepis, which was the strongest in the spleen. [Conclusion] In this paper, research on tissue localization of tyrosinase in V. macrolepis had been first reported, which provided theoretical basis for further exploring the functions of tyrosinase in V. macrolepis.

Determination of the Trace Element Contents in Plants Using Atomic Absorption Spectrophotometer

The aim of the study is to investigate the contents of trace element Se, Cd, Pb in three plants including burdock, ginkgol and garlic via graphite furnace atomic absorption and standard addition method. The results show that Se in burdock stem, skin and leaf are 32.40, 48.63, 38.10 μg/g, respectively; Cd in burdock stem, skin and leaf are 0. 160 0, 0. 300 0, 0. 140 0 μg/g, respectively; Cd in burdock stem, skin and leaf are 2. 020, 3. 960, 2. 410 μg/g, respectively. In the ginkgo and ginko leaf, Se contents are 17.63 and 16.91 μg/g, respectively ; for Cd are 0. 181 0 and 0.2020μg/g, respectively ; for Pb are 3. 572 and 4. 021 μg/g, respectively. In garlic, Se, Cd and Pb are 73. 900 0, 6. 900 0 and 0. 390 0, respectively. All the standard deviations of measured results are below 2.3%, recovery rate are from 99% to 101%.

Influence of lanthanum-doping on photocatalytic properties of BiFeO_3 for phenol degradation

A series of BiFeO3 and lanthanum‐doped BiFeO3 photocatalysts were synthesized by a facile sol‐gel method using citric acid as complexing agent, and used to remove phenol in industrial wastewater under simulated sunlight irradiation. The samples were characterized by X‐ray diffraction, energy dispersive spectroscopy, X‐ray photoelectron spectroscopy, UV‐Vis diffuse reflectance spectroscopy and photoluminescence spectroscopy. The introduction of La effectively suppressed the generation of an impurity phase. All the metals （La, Bi and Fe） are well distributed. Under simulated sunlight irradiation, the La‐doped BiFeO3 photocatalysts exhibited superior photocatalytic activity to pure BiFeO3. The 15%La‐doped BiFeO3 photocatalyst exhibited the best activity, with a degradation rate of 96%and COD removal rate of 81.53%after irradiation for 180 min, and it showed good recycling stability. The enhanced photocatalytic ability of 15% La‐doped BiFeO3 was attributed to the in‐crease of adsorbed surface hydroxyl groups, enhancement of visible light absorption and reduction of electron‐hole recombination. We confirmed that the primary active species was -OH by adding different scavengers during the photodegradation of phenol and proposed a reaction mechanism based on these experiments.