Jing Hua Yu

Influence of Slag and Fly Ash on the Self-Healing Ability of Concrete

The influence of slag and fly ash on the self-healing ability of concrete was researched by strength measurement and SEM analysis. The self-healing ratio was measured by the increase of compressive strength before and after self-healing. The optimal mixing amount of slag and fly ash were determined, and the reasonable sand ratio was obtained. Analyzing results show that the self-healing ability of concrete was the strongest when the mixing content of slag and fly ash were 30% and 40% respectively. The appropriate sand ratio was also obtained, when the sand ratio is 33%, the self-healing ability of concrete is the strongest.

A High Throughput and High Selective Chemiluminescence Method for Quantification of Bifenthrin Based on Molecularly Imprinted Film

One novel highly cross-linked, shape-controllable molecularly imprinted sol-gel film (MISF) with good thermal and chemical stability and three-dimensional network porous structure has been developed. The binding characteristic of the imprinted film to bifenthrin was evaluated by equilibrium binding experiments and imprinting-induced promotion of binding. The MISF was modified into the wells of 96 micro-well plate combined with chemiluminescence (CL) technology to establish the molecular imprinting-chemiluminescence (MI-CL) sensor. The high throughput and high selective detection sensor of bifenthrin was applied in vegetable and food samples with satisfactory results.

Synthesis and Application of Molecularly Imprinted Sol-Gel Film for Simultaneous Determination of Multi-Component Pesticide Residue

In this paper, three kinds of molecularly imprinted sol-gel film (MISF) which have good thermal and chemical stability and three-dimensional network porous structure have been developed. The material was synthesized by sol-gel technology using lambda-cyhalothrin, trichlorphon and beta-cyfluthrin as model analytes. The special structural behavior makes the material have good capability to seizure and capture template molecules which enhanced the MISF’s recognition efficiency and the property of separation and enrichment. The material was environmental friendly and easy to operate. The binding characteristic of the imprinted film to the three pesticides was evaluated by equilibrium binding experiments. The SEM of the three MISF has been performed to characterize the morphology of MISF. The MISFs were combined with chemiluminescence (CL) technology by modifying the sol-gel into 96 micro-well plate to establish one molecular imprinting- chemiluminescence (MI-CL) sensor which realized high selectivity, sensitivity and high throughput simultaneous assay of three pesticides. The proposed method was successfully applied to the simultaneous determination of multi-component pesticide residue in foodstuff.

Determination of Trace Copper with Sulfophenylazo Rhodanine by Catalytic Dynamic Spectrofluorimetry

Series new methods were established which were based on the research of determination of trace copper with four sulfophenylazo rhodanine derivatives by catalytic dynamic spectrofluorimetry under the optimum conditions. This proposed method was applied to the determination of copper in real samples with satisfactory results. According to experiment results, the influences of different active groups and substitution positions on fluorescent property of rhodanine derivatives were investigated and the relationship between molecule structure and fluorescent property was explored.

Synthesis of CdS Quantum Dots for Detection of Copper (II) Using Fluorescence Spectroscopy

We report the synthesis and characterization of a low-cost high-quality CdS quantum dots (QDs).The synthesis was performed in aqueous system. The aqueous CdS colloidal solution was prepared using thioglycollic acid as a capping agent. Zetasizer Nano ZS (Malvern, UK) was employed to characterize the partical size of CdS QDs. The UV-vis and photoluminescence (PL) spectra of samples were systematically characterized (the full width at half maximum was 38 nm). The maximum photoluminescence (PL) quantum yield (QY) was as high as 68.5 %. The fluorescence intensity was enhanced by copper (II). The relative fluorescence intensity was linear to copper (II) concentration over the range 4.0 ×10-6 - 2.8×10-5 g mL-1. The regression equation was ΔIF= 59.07+ 90.57c (c / μg mL-1). The highly monodispersed CdS QDs could be used in many fields.

Synthesis of CdTe and CdTe/CdS Core-Shell Quantum Dots and their Optical Properties

This paper describes the synthesis of CdTe and CdTe/CdS core-shell quantum dots (QDs) in aqueous solution. The quantum dots are prepared by using thioglycolic acid (TGA) as stabilizers. The synthesis procedure is simple and controllable. Different sized CdTe QDs with tuned PL wavelengths from 550 to 640 nm was synthesized by controlling reaction time within 5 h in aqueous solutions at a temperature of 100 °C. We also investigated the influence of precursor Cd/Te molar ratio for the prepared QDs. It was showed that the core-shell CdTe/CdS QDs have larger photoluminescence (PL) emission intensity than the original CdTe QDs. The synthesized core-shell CdTe/ZnS QDs have high quality, water-soluble and will be useful in applications of biolabeling, biosensing, and imaging.

Influence of Electroless Copper Deposition on the Electrochemical Performance of Si/MCMB

Si-Cu alloys have been prepared by electroless depositions with different process. Si-Cu/MCMB materials have been prepared by carbonization of the mixture of Si-Cu, MCMB and mesophase pitch. The influences of electroless deposition condition and heat-treatment temperature on the anodic performance of Cu-Si/MCMB have been studied. Compared with Si/MCMB, Si-Cu/MCMB has more stable cyclical performance. Furthermore, the Si-Cu/MCMB sample produced by cleaning and then electroless deposition on Si shows the better anodic performance than the Si-Cu/MCMB sample produced by direct electroless deposition on Si, because the former sample has more Cu contents than the latter sample.

CdSe Quantum Dots Decorated by 3-Aminobenzeneboronic Acid as Fluorescence Probe for Glucose

A simple route to the production of high-quality CdSe quantum dots (QDs) is presented. The characterization of CdSe QDs was measured by Zetasizer Nano ZS, ultraviolet-visible spectoscopy and fluorospectrophotometer. The CdSe QDs were decorated by 3-Aminobenzeneboronic acid to obtain good fluorescent characteristic. Under the optimal conditions, the decreased normalized absorbance was linear to the concentration of glucose from 1.0×10−7 to 2.9×10−6 mol·L-1 with a detection limit of 5.0´10-8 mol·L-1. The relative standard deviation (RSD) for the determination of 1.0×10-7 mol·L-1 was 1.4 % by 11 replicate determination. In this paper, the fluorescent behavior of glucose with the decorated CdSe QDs was studied, and it is found that the system has a high sensitivity and selectivity for analysis of glucose.

Influence of Cement Coarse Particle on the Self-Healing Ability of Concrete Based on Ultrasonic Method

The influences of particle size and mixing content of coarse cement on the self-healing ability of concrete were researched by ultrasonic method. Damaged degree was measured through the decrease of ultrasonic head wave amplitude (UHA) before and after loading. The relationship between damaged degree and self-healing ratio of concrete was built based on the experimental results as well as the relationship between cement diameter and self-healing ratio of concrete. Analyzing results show that UHA can evaluate the damaged degree of concrete clearly. There exists a damaged threshold of the concrete during loading. Under the same mixing content of coarse cement, when the damaged degree is higher than the threshold, the self-healing ratio of concrete decreases with the increase of damaged degree and increases with the increase of coarse cement diameter, however, while the damaged degree is less than the threshold, the self-healing ratio of concrete increases with both the increase of damaged degree and coarse cement diameter.