水热法新型水溶性荧光碳点的制备及其性能研究

以阿拉伯糖和磷酸酪蛋白肽进行水热反应,制备水溶性多色荧光碳点,利用透射电子显微镜(TEM)、紫外吸收光谱(UV)、荧光光谱(FL)、红外光谱(FTIR)和X射线衍射(XRD)等对所制备碳点的粒径大小、吸收光谱、发光性质、表面基团等进行表征,并考察了其性能和对不同金属离子的识别作用。结果表明:制备的荧光碳点平均粒径为4.62 nm,其紫外最大吸收波长为281 nm,XRD峰值约为21°,可在紫外灯下发出明亮的荧光,最大发射波长为414 nm,且呈荧光多元发射。红外光谱分析表明存在—COOH,—NH2和—OH基团。该荧光碳点具有良好的性能,且对Cu2+和Fe3+有较强的选择性识别作用,其原因可能是荧光碳点的聚合导致粒径增大从而使荧光强度减弱。该碳点有望作为荧光探针用于检测分析和生物成像等领域。     

葡萄糖酸碳量子点的合成及其光学性能的研究

以葡萄糖酸为碳源,采用微波法、热解法和水热溶液法合成了水溶性较好的蓝色荧光碳量子点。用透射电镜(TEM)观察其形貌,荧光光谱(FL)和紫外可见光谱(UV)探究其激发和发射光谱,用时间分辨光谱(TRF)测其荧光寿命值。微波和热解法制备的碳量子点粒径在2.5~7.5 nm之间,激发波长为360 nm,发射波长为450 nm,荧光发射依赖激发波长,有三个荧光寿命,表面状态不均一。水热法制备的碳量子点,粒径在3.0~8.5 nm之间,激发波长为350 nm,发射波长为430 nm,荧光发射不依赖激发波长,只有一个荧光寿命值,表面状态均一。水热法合成的碳量子点荧光量子产率高为6.01%,为进一步研究葡萄糖酸制备碳量子点提供参考。     

新型水溶性多色荧光碳点的制备及细胞成像研究

以鸡蛋清和牛奶分别与葡萄糖进行水热反应,制备水溶性多色荧光碳点,通过膜和柱层析分离纯化,利用透射电子显微镜(TEM)、紫外吸收光谱(UV)、荧光光谱(FL)、红外光谱(FTIR)等技术对所制备碳纳米粒子的粒径大小、吸收光谱、发光性质、表面基团进行表征。将所制备的碳点与小鼠黑色素瘤细胞共孵育,进行细胞成像应用评价。结果表明:制备的两种水溶性荧光碳点平均粒径分别为2.5 nm和4.9 nm,可在紫外灯下发出明亮的荧光,紫外最大吸收波长为250 nm。基于鸡蛋清或牛奶与葡萄糖反应制备的多色荧光碳量子点具有良好水溶性,其荧光光谱最大发射波长分别在410 nm和400 nm处,同时在660~800 nm激发波长范围内具有上转换性质,且荧光发射光谱随着激发光波长的增加发生红移。红外光谱表明存在—COOH、—NH2和—OH基团。细胞成像结果表明,在405 nm或488 nm激光照射下,所制备的碳点在细胞内的荧光成像清晰可见,而且在碳点浓度小于2.5 mg/mL时,均表现出较低的细胞毒性。     

枫树叶荧光碳量子点的合成及其传感性能研究

以枫树叶为原料,硼氢化钠为还原剂,利用水热法合成了一种新型的荧光碳量子点CQDs-fsy。利用XRD,TEM和FT-IR对碳量子点的结构进行了表征,利用紫外和荧光光谱仪研究了该碳量子点的光学性质,该荧光碳点的荧光量子产率为5.60%,最大激发波长为348nm,最大发射波长为428 nm。该碳点具有规则的球形分散结构;平均粒径为5~10 nm;表面富含羧基,氨基和羟基官能团;该碳点在水溶液中对Hg~(2+)具有专一识别能力,线性范围为5.00×10~(-7)~1.55×10~(-5)mol/L,线性方程为y=-10.37 x+337.24,R~2=0.996,检出限为2.01×10~(-8)mol/L。     

啤酒基荧光碳点的绿色合成及其在Fe3+检测和细胞成像中的应用

以啤酒为碳源,通过水热法合成了一系列啤酒基荧光碳点,其中以齐鲁工业大学自酿啤酒合成的碳点相比其他品牌啤酒合成的碳点具有更好的发光效率。该碳点表现出发射波长随激发波长变化而变化的性质,最大发射波长为475 nm,呈现蓝色荧光。利用透射电子显微镜、X射线衍射技术、傅里叶变换红外光谱、紫外－可见吸收光谱和荧光光谱等对碳点结构及其光学特性进行了表征。基于Fe3+对碳点的特异性荧光猝灭,建立了灵敏的Fe3+检测方法,线性范围为0.3 ~ 45 μmol/L,检出限达91 nmol/L,并成功用于实际水样中Fe3+浓度的分析。所合成的碳点具有良好的生物相容性和细胞膜穿透性,可用于细胞内Fe3+的可视化成像分析和多色细胞成像。     

碳量子点荧光探针的制备及其在苦味酸检测中的应用

以银杏叶为原料,采用水热法制备得到新型荧光碳量子点(CQDs)。该碳量子点的平均粒径为5.5 nm,最大激发波长为335 nm,最大发射波长为418 nm。基于碳量子点荧光光谱与苦味酸(PA)吸收光谱存在部分重叠而发生荧光共振能量转移(FRET),建立了以碳量子点作为荧光探针用于苦味酸检测的新方法。在最佳实验条件下,加入苦味酸前、后的荧光强度比值(I₀/I)与苦味酸浓度(c)在0.2～800μmol/L范围内呈良好的线性关系,相关系数(r)为0.999 5,检出限(LOD)为32 nmol/L。在5、40、80μmol/L加标水平下,实际水样中苦味酸的回收率为98.0%～104%,相对标准偏差(RSD)为1.0%～3.2%。该方法可用于实际样品中苦味酸的灵敏、快速和高效检测。     

川木香水热法一步合成荧光碳量子点及光学性能研究

以中药材川木香原药为碳源，采用水热法一步合成了荧光碳量子点。通过水热法实验条件优化，获得制备荧光碳量子点的最佳实验参数，通过透射电镜(TEM)对荧光碳量子点进行形貌表征，通过X射线光电子能谱分仪(XPS)对荧光碳量子点进行元素组成分析，通过荧光光谱和紫外-可见吸收光谱对荧光碳量子点进行了光学性能研究。结果表明：川木香用量1.00 g,水热反应温度180℃,水热反应时间2.0 h时，制备得到的荧光碳量子点光学性能最佳。荧光碳量子点平均粒径为5 nm,主要含有C元素和O元素，最大激发波长为360 nm,对应的发射波长为420 nm,特征吸收峰为280 nm,量子产率为12.9%。     

豆奶粉提取碳点及含碳点荧光纳米纤维的制备

以豆奶粉为碳源, 以有机硅烷为钝化剂, 用水热合成法制备碳点, 采用静电纺丝技术, 以碳点与聚乙烯吡咯烷酮(PVP)共混溶液为纺丝液, 制备了含碳点的纳米纤维. 通过紫外吸收光谱、 荧光吸收光谱和荧光发射光谱表征了碳点性质. 结果显示, 所得碳点纳米纤维直径分布均匀, 形貌良好, 碳点分散溶液在340~540 nm的紫外光激发下发出强青绿色荧光, 荧光发射峰出现在550 nm处, 并且随着激发波长增加有微弱的红移.     

柠檬酸荧光碳点的合成及其在Fe(Ⅲ)检测和细胞成像中的应用

以柠檬酸为原料,采用一步水热法合成荧光碳点。所合成的荧光碳点在310nm激发波长下的荧光量子产率为5.3%,发射光谱随着激发波长红移而红移。透射电镜(TEM)表征显示荧光碳点在水溶液中分布均匀,平均粒径为2.9nm。红外(IR)光谱和Zeta电位结果表明碳点表面有羧基和羟基等活性官能团。Fe(Ⅲ)对这些荧光碳点表现出选择性猝灭效果,这种现象可以用于Fe(Ⅲ)检测。在10mmol/L的HEPES缓冲溶液(pH=7.0)中,荧光碳点的荧光强度随着Fe(Ⅲ)浓度的增加逐渐衰减。该方法对Fe(Ⅲ)测定的线性范围为100~500μmol/L,检出限为112.5nmol/L。细胞成像结果表明,柠檬酸的碳点可进入到B16-F10细胞内,并在405nm和488nm激光照射下发出不同颜色的荧光。以上结果表明该碳点在Fe(Ⅲ)检测和细胞成像方面有潜在应用价值。     

氮硫共掺杂碳点的制备及其对牛奶中土霉素的检测

以柠檬酸和谷胱甘肽为原材料,通过热解法一步合成一种氮硫共掺杂蓝色荧光碳点（N,S-CDs）。使用透射电子显微镜（TEM）、紫外-可见吸收光谱、荧光光谱、X射线光电子能谱等技术对制备的碳点进行形貌及光学性质表征。结果表明,该碳点的激发波长和发射波长分别为366和440 nm,荧光产率为0.46,平均粒径为（2.55 ± 0.75） nm。土霉素可有效猝灭该碳点的蓝色荧光,且具有良好的选择性。将该碳点用于牛奶中土霉素的检测时,在0.77~18.40 μg/mL的范围内,（F₀-F）/F₀与土霉素浓度有良好的线性关系,回归方程为y=0.02282x+0.02913,检出限为0.09 μg/mL。该检测方法具有简单易操作的优点。     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.