Effect of Isobutyl-triethoxy-silane Penetrative Protective Agent on the Carbonation Resistance of Concrete

Effect of isobutyl-triethoxy-silane penetrative protective agent on the carbonation resistance of the concrete was studied.The concrete specimens for the 28 d accelerated carbonation process were manufactured with w/c of 0.49 and 0.64,both in the presence and absence of silane and mineral admixture.The penetration of isobutyl-triethoxy-silane and the carbonation of concrete were investigated by penetration depth,carbonation depth,XRD,SEM,and pore size distribution.The results showed that concrete compactness played an important role in the silane penetration and carbonation resistance.Penetration depth of silane-treated concrete mainly depended on the compactness of the concrete,and could not remarkably change through the accelerated carbonation process.In the accelerated carbonation process,penetrative protective agent improved the carbonation resistance of the higher compactness concretes but accelerated the carbonization process of the lower compactness concretes.As penetrative protective agent penetrated along the external connectivity pores into concrete not filling the entire surface area,the inorganic film could not fully protect the Ca（OH）_2 phase from carbonation.After 28 d accelerated carbonation,fibrous hydration products disappeared and the surface holes decreased.Due to the formation of carbonized products,the porosity of the concrete surface decreased,especially in high-strength concrete.

Optimization of Freeze-drying Protective Agents for Lactobacillus plantarum KLDS1.0391 by Response Surface Methodology

In this study, the Single Factor Test（SFT） was used to optimize the pre-freezing conditions of L. plantarum KLDS1.0391（KLDS1.0391）. Further, the Freeze-Drying Protective Agents（FDPA） of KLDS1.0391 was optimized by Response Surface Methodology（RSM）. The optimum pretreatment conditions were as the follows： initial concentration of KLDS1.0391 was 1011 CFU · m L-1 and KLDS1.0391 was pre-freezed at –80℃ for 8 h to achieve the survival rate of 46.21%. The main components of FDPA were skim milk, sucrose, sodium glutamate and Tween-80. And the influence of four factors on the survival rate of KLDS1.0391 in freeze-drying was in order as the follows： skim milk〉sucrose〉Tween-80〉sodium glutamate. The optimal FDPA composition was skim milk 11.3%, sucrose 9.8%, sodium glutamate 5.1% and Tween-80 0.2%. Under the above conditions, the survival rate of the cells was 82.98%. Comparing the predicted values, the relative error was 0.37% and the difference was not significant, which indicated that the established model could effectively reflect the actual protection of FDPA to KLDS1.0391.

Optimization of Protective Agent Formulation for Soybean Rhizobium Strain HW-05 by Response Surface Methodology

[Objective] This study aimed to investigate the protective effects of proteins, salts, sugars and trace elements on soybean rhizobium strain HW-05 by response surface methodology. [Method] Different types, combinations, ratios and concentrations of protective agents were designed. Under simulated conditions, the optimal protective agent formulation was screened for improving the survival rate and survival time of soybean rhizobium strain HW-05. The optimal combination of significant factors was determined by Box-Behnken central composite design. [Result] Three significant factors affecting effective number of viable cells were screened, including peptone, xanthan gum and NaCl. The final concentration of each compound was optimized 0. 13% peptone, 0.011% xanthan gum, 0.30% NaCl. [Conclusion] After addition of protective agent and preservation at room temperature for six months, effective number of viable cells of soybean rhizobium strain HW-05 reached 3.185 ×10^8 CFU/ml. The survival rate of HW-05 cells was improved by more than 25% compared with the control group （2.458×10^8 CFU /ml）.

Magnesium acethyltaurate as a potential agent for retinal and optic nerve protection in glaucoma

Glaucoma is the second leading cause of irreversible vision impairment affecting more than 70 million people worldwide with approximately 10%suffering from glaucoma-related bilateral blind（Quigley and Broman,2006）.It is a multi-factorial disease that is characterized by optic nerve damage and visual field loss.Progressive loss of retinal ganglion cells（RGCs）resulting in visual field deficits is the hallmark of glaucoma.

Heat Stability of HA Antigen in Influenza Virus Rapid Diagnosis Kit

[ Objective] The aim was to select protective agent of HA antigen of influenza virus. [ Method] H3N2 and H1 N1 subtype influenza virus were added into A - F groups to conduct accelerated test at 37 ℃and measure HA titer through hemagglutination test. t Result] Hemagglutination titers of H3 N2 and H, N1 subtype influenza virus were 20 and 32 in group A （ with PBS buffer solution） for 28 d; heat stability of HA antigen proved the best in group F （with BSA, fucose, proclin 300, triton 100） ; hemagglutination titers of HA antigen of H3N2 and H1 N1 subtype virus were 48 and 96 for 28 d. [ Conclusion] Components in group F were best in protection on HA antigen, which can be a candidate of protective agent.

Development and Performance Evaluation of a Deep Water Synthetic Based Drilling Fluid System

With the enhancement of environmental protection awareness, the requirements on drilling fluid are increasingly strict, and the use of ordinary oil-based drilling fluid has been strictly restricted. In order to solve the environmental protection and oil-gas reservoir protection problems of offshore oil drilling, a new synthetic basic drilling fluid system is developed. The basic formula is as follows: a basic fluid (80% Linear a-olefin + 20% Simulated seawater) + 2.5% nano organobentonite + 3.5% emulsifier RHJ-5# + 2.5% fluid loss agent SDJ-1 + 1.5% CaO + the right amount of oil wetting barite to adjust the density, and a multifunctional oil and gas formation protective agent YRZ has been developed. The performance was evaluated using a high-low-high-temperature rheometer, a high-temperature and high-pressure demulsification voltage tester, and a high-temperature and high-pressure dynamic fluid loss meter. The results show that the developed synthetic based drilling fluid has good rheological property, demulsification voltage ≥ 500 V, temperature resistance up to 160°C, high temperature and high pressure filtration loss < 3.5 mL. After adding 2% - 5% YRZ into the basic formula of synthetic based drilling fluid, the permeability recovery value exceeds 90% and the reservoir protection effect is excellent. The new synthetic deepwater drilling fluid is expected to have a good application prospect in offshore deepwater drilling.

Advanced Strategies for Stabilizing Single‑Atom Catalysts for Energy Storage and Conversion

Well-defined atomically dispersed metal catalysts(or single-atom catalysts)have been widely studied to fundamentally under-stand their catalytic mechanisms,improve the catalytic efficiency,increase the abundance of active components,enhance the catalyst utilization,and develop cost-effective catalysts to effectively reduce the usage of noble metals.Such single-atom cata-lysts have relatively higher selectivity and catalytic activity with maximum atom utilization due to their unique characteristics of high metal dispersion and a low-coordination environment.However,freestanding single atoms are thermodynamically unstable,such that during synthesis and catalytic reactions,they inevitably tend to agglomerate to reduce the system energy associated with their large surface areas.Therefore,developing innovative strategies to stabilize single-atom catalysts,including mass-separated soft landing,one-pot pyrolysis,co-precipitation,impregnation,atomic layer deposition,and organometallic complexation,is critically needed.Many types of supporting materials,including polymers,have been commonly used to stabilize single atoms in these fabrication techniques.Herein,we review the stabilization strategies of single-atom catalyst,including different synthesis methods,specific metals and carriers,specific catalytic reactions,and their advantages and disadvantages.In particular,this review focuses on the application of polymers in the synthesis and stabilization of single-atom catalysts,including their functions as carriers for metal single atoms,synthetic templates,encapsulation agents,and protection agents during the fabrication process.The technical challenges that are currently faced by single-atom catalysts are summarized,and perspectives related to future research directions including catalytic mechanisms,enhancement of the catalyst loading content,and large-scale implementation are proposed to realize their practical applications.