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Purpose This study aims to examine the information transfer effects of customers’ credit rating downgrades on supplier firms. Design/methodology/approach In this study, the authors use suppliers’ cumulative abnormal returns around customers’ credit rating downgrade events to identify how shocks to customer credit impact supplier equity prices. The authors also incorporate ordinary least squares and weighted least squares regressions regression analysis of the determinants of supplier market response to customer downgrades. Findings The authors find that customer credit rating downgrades present significant negative shocks to the stock prices of supplier firms. Moreover, the authors show that the information transfer effects are determined by both firm- and industry-level factors, including the market anticipation of downgrades, the strength of the customer–supplier linkage, the industry rivals’ reactions to the downgrades and investor attention. The authors also find that the likelihood that a supplier will receive a rating downgrade is significantly higher following its primary customer firm’s downgrade. Originality/value To the best of the authors’ knowledge, this paper is the first to explore the information transfer effects of credit rating downgrades on primary stakeholders within the supply chain. The authors document that customer–supplier networks have valuable implications for the spillover effect across debt and equity holders. Information about customers’ financial stress is incorporated into suppliers’ equity prices outside of the context of customer bankruptcy.

With the increasing frequency of human exposure to blue light, the harmfulness of blue light has received wider attention. The damaging effect of blue light is complex and long-lasting. In this study, Drosophila melanogaster was used as a model organism to investigate the protective effect of the senolytic drug quercetin on blue light toxicity. As one of the first senolytic drugs discovered, quercetin not only has antioxidant properties, but also has been used to treat various neurological disorders. Our study shows that quercetin can effectively prolong the survival of flies under blue light irradiation, and it significantly increases the egg production of female flies under blue light. In addition, after flies intaking quercetin under blue light, both the spontaneous activity and nutrient metabolism show significant sex-specificity. The experimental results provide a potentially effective intervention method for organisms to defend against blue light toxicity, and reveal a new function of the senolytic drug quercetin from another perspective.

Purpose- the reason behind this work is to fine out the rising service of Mobile Money Transaction which offers banking services to all manner of persons only if they hold a phone can impact the biggest economy of the country Ghana thus agriculture which in this sector cocoa production in the country. Design/methodology/approach- the paper draws literature from numerous studies that relates to the subject of discussion. 204 questioners were designed and administered out of which 204 was correctly answered by small scale cocoa farmers and used for the analysis of this paper. Spss, excel and Smart Partial Least Square 3.0 was used in analyzing the data. Findings – Mobile Money Services has a strong service quality and thus impact transaction efficiency of the service positively. The transaction efficiency of the Mobile Money services also has a strong impact on the supply chain performance of the small holder cocoa farmers. Research limitations/implementations- the educational level of most of the respondents were low thus finding it difficult to read and understand. Researcher had to break things down and answer on their behalf. There is no clear laydown procedure for the supply chain of cocoa farmers. Most respondents live in the remotest part of the villages. Originality and value- there are so many papers on mobile money but no studies have been able to link the transactional efficiency of the service to agricultural supply chain. KEY WORDS- Mobile money services, supply chain performance, transactional efficiency, mobile money service quality Paper type- Research

Pretargeted imaging has emerged as a promising approach to advance nuclear imaging of malignant tumors, however, the application of pretargeted strategy for multimodality imaging of enzyme activity in vivo is challenging. Herein, we combine the enzyme-mediated fluorogenic reaction and in situ self-assembly with the inverse electron demand Diels-Alder (IEDDA) reaction to develop an activatable pretargeted strategy for multimodality imaging. The trans -cyclooctene (TCO) bearing small-molecule probe, P-FFGd-TCO , can be activated by alkaline phosphatase and in situ self-assembles into nanoaggregates ( FMNPs-TCO ) retained on the membranes, permitting to (1) amplify near-infrared (NIR) fluorescence (FL) and magnetic resonance imaging (MRI) signals, and (2) enrich TCOs to promote IEDDA ligation. The Gallium-68 ( 68 Ga) labeled tetrazine can readily conjugate the tumor-retained FMNPs-TCO to enhance radioactivity uptake in tumors. Hence, strong NIR FL, MRI and positron emission tomography (PET) signals are concomitantly achieved, allowing for pretargeted multimodality imaging of ALP activity in HeLa tumor-bearing mice.

As illegal mining in Ghana has become increasingly rampant ever, this study aimed at examining the effect of illegal mining on the dimensions of sustainability performance among crop farmers and the challenges they face because of illegal mining in the Ashanti Region, Ghana. To investigate the intriguing connections among illegal mining and sustainability performance among crop farmers, this paper draws on multidisciplinary literature and collects empirical data from 250 respondents in the Atwima Nwabiagya and Atwima Mponua Districts, Ghana to test the proposed model and hypotheses using structural equation modeling. All the three (3) elements or paradigms of sustainability performance were negatively affected by illegal mining activities. It was also observed that a significant positive relationship exists among all the elements of sustainability performance hence a consequence on one element may affect the other. Unlike most research on illegal mining that has been theoretical, this study represents one of the few empirical analyses of how illegal mining may affect sustainability performance

PurposeAs focal buyers implement sustainable supplier management (SSM) to advance their supply chain sustainability, the purpose of this paper is to provide a more nuanced understanding of how buyers’ use of power may incite varying perceptions of justice from suppliers that affect sustainable supplier performance (SSP).Design/methodology/approachThis paper draws on multidisciplinary literature and collects empirical data from 181 supplying firms in China to examine the complex links among power use, justice, SSM, and sustainable performance using partial least squares structural equation modeling.FindingsBoth coercive and reward buyer power can facilitate SSM implementation and justice perception moderates the impact of SSM on SSP. Furthermore, coercive power adversely influences justice evaluation, thereby attenuating the effect of SSM on performance.Research limitations/implicationsThis study complements and extends sustainable supply chain management research by evaluating SSM: on environmental, social and economic performance; from the perspectives of suppliers; and in an emerging market where many suppliers of Western firms are located. It also adds to behavioral SCM research by examining how buyers’ exercise of power might influence suppliers’ justice perception.Practical implicationsTo implement SSM, focal buyers cannot simply issue codes of conduct to suppliers and ignore suppliers’ disposition to commit to standards. While coercive power might be convenient and tempting for buying firms, managers ought to be judicious in the use of coercion.Originality/valueThis is the first large-scale empirical investigation on the links among power use, justice, SSM and sustainable performance from the perspectives of suppliers in an emerging economy.

Purpose As supply chain sustainability has become more urgent than ever before, this study aims to provide a more nuanced understanding of how supplying firms’ sustainability motives influence their compliance and commitment, as well as sustainable performance, as they respond to buyers’ sustainable supplier management programs. Design/methodology/approach To investigate the intriguing links among sustainability motives, compliance/commitment and sustainable performance of supplying firms, this paper draws on multidisciplinary literature and collects empirical data from 281 supplying firms in China to test the proposed model and hypotheses using structural equation modeling. Findings Instrumental and moral motives make comparable contributions to compliance; moral motives exert stronger influence on firms’ commitment to sustainable practices. In addition, although compliance has a greater impact on economic and environmental performance, commitment is far more robust in improving environmental and social performance. Research limitations/implications Unlike most research on motives that has been theoretical, this study represents one of the few empirical analyses of how motives may affect sustainable performance. Examining the challenges from the perspectives of supplying firms, it also adds to the SSCM literature by making clear how compliance and commitment may differentially predict sustainable performance. Practical implications Although instrumental and moral motives can be complementary in advancing sustainable practices, it is imperative for firms to integrate moral considerations into sustainability decision-making and move beyond compliance, if they are to contribute meaningfully to a better society and cleaner environment. Originality/value This is the first large-scale empirical investigation on the links among motives, compliance, commitment and sustainable performance from the perspectives of suppliers.

Programmed death ligand 1 (PD-L1) expression level is a reproducible biomarker for guiding stratification of patients to immunotherapy. However, the most widely used immunohistochemistry method is incompetent to fully understand the PD-L1 expression level in the whole body because of the highly complex PD-L1 expression in the tumor microenvironment. In this work, a novel small-molecular radiotracer [

The jamming transition and jammed packing structures of hydrogel soft ellipsoids are studied using magnetic resonance imaging techniques. As the packing fraction increases, the fluctuation of local free volume decreases and the fluctuation of particle deformation increases. Effective thermodynamic quantities are obtained by characterizing these fluctuations using k-gamma distributions based on an underlying statistical model for granular materials. Surprisingly, the two granular temperatures measuring the relative fluctuations of both free volume and particle deformation remain basically unchanged as the packing fraction increases. The total configurational entropy is also approximately constant for packing with different packing fractions. The significantly different behaviors of these effective thermodynamic quantities compared with hard sphere systems are further attributed to a statistically affine structural transformation of the packing structures along with particle deformations when the packing fraction changes.

The development of metallic monolithic catalysts with various morphologies to catalyze rapid combustion of volatile organic compounds (VOCs) under high space velocity is a profound challenge in catalyst research. Herein, we reported the preparation of novel electrically heated monolithic Pt and Pd catalysts supported on an FeCrAl metal wire. The catalysts exhibited high catalytic activity for the VOC combustion to CO2 and H2O under low-current DC power. Notably, the catalysts exhibited nearly 100% toluene and ethyl acetate conversion rates under a DC power of 5 W and 8 W and a space velocity of 30 000 mL h−1 g−1 with a combustion response time of less than 30 s. The exceptional activity of the catalysts can be attributed to a well-adhered alumina coating that formed on the surface of the FeCrAl metallic substrate after thermal treatment and highly dispersed Pt and Pd nanoparticles on the surface of an alumina coating. Meanwhile, surface temperature can instantly reach the desired ignition point, because of high thermal conductivity and electrical conductivity.

Concentrating light technology is used to improve photoreduction of CO2 to CH4 reaction on semiconductor catalysts such as TiO2. The catalysts were prepared by anodization method and characterized by XRD, SEM, XPS and photoillumiation. The results showed that the CH4 yield rate could be raised from 0.70 μmol g−1 h−1 to 20.67 μmol g−1 h−1 under concentrating light, and it could be further increased to 28.49 μmol g−1 h−1 after pretreatment in the air. It is inferred that the concentrating light increases CO2 conversion not only by heightening light intensity, but also by improving the surface properties of the catalyst.

An activated carbon pore-expanding technique was achieved through innovative reactivation by CO2/microwave. The original and modified activated carbons were characterized by nitrogen adsorption–desorption, scanning electron microscopy, transmission electron microcopy, and Fourier transform infrared spectroscopy. The mesopore volume increased from 0.122 cm3·g− 1 to 0.270 cm3·g− 1, and a hierarchical pore structure was formed. A gradual decrease in the phenolic hydroxyl and carboxyl groups on the surface of activated carbon enhanced the surface inertia of granular activated carbon (GAC). The toluene desorption rate of the modified sample increased by 8.81% compared with that of the original GAC. Adsorption isotherm fittings revealed that the Langmuir model was applicable for the original and modified activated carbons. The isosteric adsorption heat of toluene on the activated carbon decreased by approximately 50%, which endowed the modified sample with excellent stability in application. The modified samples showed an enhanced desorption performance of toluene, thereby opening a way to extend the cycle life and improve the economic performance of carbon adsorbent in practical engineering applications.

Programmed death ligand 1 (PD-L1) expression level is a reproducible biomarker for guiding stratification of patients to immunotherapy. However, the most widely used immunohistochemistry method is incompetent to fully understand the PD-L1 expression level in the whole body because of the highly complex PD-L1 expression in the tumor microenvironment. In this work, a novel small-molecular radiotracer [18F]LG-1 based on the biphenyl active structure was developed to evaluate PD-L1 expression in tumors. [18F]LG-1 was obtained by conjugating and radiolabeling with [18F]FDG with high radiochemical purity (>98.0%) and high molar activity (37.2 ± 2.9 MBq/nmol). In vitro experimental results showed that [18F]LG-1 could target PD-L1 in tumor cells and the cellular uptake in A375-hPD-L1 cells (PD-L1 + ) was clearly higher than that in A375 cells (PD-L1-). In vivo dynamic PET images of [18F]LG-1 provided clear visualization of A375-hPD-L1 tumor with high tumor-to-background contrast, and the tumor uptake was determined to be 3.98 ± 0.21 %ID/g at 60 min, which was 2.6-fold higher than that of A375 tumor. These results suggested that [18F]LG-1 had great potential as a promising PD-L1 radiotracer.

Electricity is the basic necessity for daily life and a core component for a country's economic growth. However, in DR Congo access to electricity is less than 20%. This paper investigates various factors affecting electricity supply in DR Congo from 2000 to 2018. We utilized seven different determinants including economic growth, population, life expectancy, electricity production, access to electricity, labor force, and unemployment rate, to analyze their impact on electricity consumption. FMOLS (fully modified ordinary least square) and DOLS (dynamic ordinary least square) regression techniques were used to explore the relationship. While, canonical cointegrating regression (CCR) estimation was employed as robust estimator. The results indicate that economic growth, population, life expectancy, electricity production, access to electricity and labor force have a positive effect on and increase electricity consumption. However, unemployment rate has a negative impact, namely an increase in unemployment rate decreases electricity consumption. The results further indicate that access to electricity is the most prominent determinant among all and has the most severe impact on electricity consumption. Based on the results, this study puts forward several policy implications.

A series of Ni-Cu supported on SBA-15 were prepared by impregnation, and used as catalysts in cyclohexane dehydrogenation for hydrogen production. The results indicated that the addition of Cu into Ni changes the crystal structure of metal Ni, and forms Ni-Cu alloy. Thus, Cu improves the reduction properties of Ni. Conversely, Ni stables and disperses metal Cu. With the space limitation of the ordered channels and high surface area of SBA-15, the bimetallic Ni-Cu/SBA-15 catalysts expose large amounts of selective active sites composed uniformly with Ni and Cu. Therefore, they present not only excellent catalytic performance for cyclohexane dehydrogenation, but also low coke formation. The in-situ DRIFT studies have shown the vinyl species, indicating the existence of alkenes in the reactive intermediates. Additionally, the strong absorption of benzene on the metal could induce benzene was dehydrogenated further to carbon.

CO2 photoreduction is an attractive process which allows the storage of solar energy and synthesis of solar fuels. Many different photocatalytic systems have been developed, while the alternative photo-reactors are still insufficiently investigated. In this work, photoreduction of CO2 with H2O into CH4 was investigated in a modified concentrating solar reactor, using TiO2 and Pt/TiO2 as the catalysts. The TiO2 and Pt/TiO2 samples were extensively characterized by different techniques including powder X-ray diffraction (XRD), N2 adsorption/desorption and UV–vis absorption. The catalytic performance of the TiO2 and Pt/TiO2 samples in the gas phase was evaluated under unconcentrated and concentrated Xe-lamp light and nature solar light with different concentrating ratios. Various parameters of the reaction system and the catalysts were investigated and optimized to maximize the catalytic performance of CO2 reduction system. Compared with the normal light irradiation, the TiO2 and Pt/TiO2 samples show higher photocatalytic activity (about 6–7 times) for reducing CO2 into CH4 under concentrated Xe-lamp light and nature solar light. In the range of experimental light intensity, it is found that the concentration of the light makes it suitable for the catalytic reaction, and increases the utilization efficiency of the TiO2 and Pt/TiO2 samples while does not decrease the quantum efficiency.

In Ghana, there is growing concerns about the quality of service provided by banks to their customers. The major issues concerning Service Quality related to customer relations, access to saved monies, limited loans with high-interest rates, and delays in service delivery. This study investigated the impact of service quality on customer satisfaction and loyalty in the banking sector of Ghana. A survey was conducted in three regions of Ghana with the highest banking activities in which a set of questionnaires were administered to 157 respondents. Data collected was analyzed using the Structural Equation Modelling-Partial Least Squares (SEM-PLS). It was revealed that customer satisfaction is highly influenced by the quality of services offered to them. The satisfaction derived by customers makes them loyal, which is an advantage to service providers in realizing their profit motive. The results of this study suggest that service quality is the precursor of customer satisfaction and instill confidence and loyalty in customers

The effects of metal particle size on catalytic activities of Cu/SBA-15 with different Cu content were investigated for high selectivity of cyclohexane dehydrogenation. Overall, the smaller Cu nanoparticles exhibit higher hydrogen evolution rate or lower active energy barrier. But, even when the smaller CuO nanoparticles have formed on the catalyst with lower Cu content during the calcination, they would be more prone to sinter after reduction. An appropriate Cu content could lead to form amounts of stable and small Cu nanoparticles after high-temperature treatment with the space limitation by ordered channels of SBA-15.

A series of Ni-Cu/SiO2 catalysts were prepared by sol-gel method for use in the dehydrogenation of cyclohexane to evolve hydrogen. The Ni/SiO2 catalyst exhibits excellent catalytic activity but low selectivity, due to the highly dispersion of Ni species. After the addition of Cu, the Ni-Cu nanoparticles with narrow size distribution (3–6 nm) and a uniform structure of bimetallic Ni and Cu has been formed, and it drastically improves the selectivity to benzene. A 94.9% conversion of cyclohexane with 99.5% benzene selectivity was observed at 350 °C in a continuous fixed bed flow reactor.

Four CePr mixed oxides with different structures were designed and synthesized using a solid-phase grinding method: a uniform solid solution of Ce and Pr (CePr-NN), Pr6O11-coated CeO2 (CePr-NO), CeO2-coated Pr6O11 (CePr-ON), and particle packing of CeO2 and Pr6O11 (CePr-OO) were obtained, and characterized by XRD, H2-TPR, TEM and TG. The results show that CePr-NN exhibits the best low temperature catalytic activity among the CePr catalysts. CeO2 is the major active phase on the surface of the CePr catalysts, and the use of Pr6O11 as the framework maintains the thermal stability of the CePr composite oxide. Moreover, both the oxygen storage capacity and mobility of the active oxygen of the catalyst were improved with the incorporation of Pr into CeO2, resulting in a higher combustion rate. The “molten state” which appeared during the preparation when nitrate was used as the precursor, plays a significant role in the migration of Ce and Pr, and is the premise of forming different structures of solid solution or coating structure.

This study investigates whether a firm's competitive advantage, measured by its relative operating efficiency, can be maintained in the long run. Based on a sample of US listing firms in the wholesale and the retail industries from 1995 to 2015, we examine the dynamics of the trend and stability of firms' operating efficiency in the long run. We find that companies that are moving ahead in the short run cannot guarantee their operating efficiency status in the long run. In the long run, operating efficiency can trend upwards, downwards, fluctuate, or remain flat. The findings are consistent to both industries, except that in the retail industry, there are more firms that consistently fall behind than firms that are in other categories of efficiency. This study provides implications for firms to measure and improve their operating efficiency dynamically over the short and long horizons to win the competitive market.

Programmed cell death protein-ligand 1 (PD-L1) is a crucial biomarker in immunotherapy and its expression level plays a key role in the guidance of anti-PD-L1 therapy. It had been reported that PD-L1 was quantified by noninvasive imaging with more developed radiotracers. In our study, a novel [18F]fluoride labeled small molecule inhibitor, [18F]LN was designed for positron emission tomography (PET) imaging in both PD-L1 transfected (A375-hPD-L1) and non-transfected (A375) melanoma-bearing mice. LN showed the specificity (IC50 = 50.39 ± 2.65 nM) to PD-L1 confirmed by competitive combination and cell flow cytometry (FACS) analysis. The radiotracer [18F]LN was obtained via 18F-19F isotope exchange from precursor LN. After radiosynthesis, [18F]LN was achieved with a high radiochemical purity (RCP) above 95% and got a favorable molar activity of 36.34 ± 5.73 GBq/μmol. [18F]LN displayed the moderate affinity (Kd = 65.27 ± 3.47 nM) to PD-L1 by specific binding assay. And it showed 1.3-fold higher uptake in A375-hPD-L1 cells than that in A375 cells. PET imaging revealed that [18F]LN could enter into PD-L1 expressing tumor site and visualize the outline of tumor. And tumor uptake (1.96 ± 0.27 %ID/g) reached the maximum at 15 min in the positive group, showed 2.2-fold higher than the negative (0.89 ± 0.31 %ID/g) or the blocked (1.07 ± 0.26 %ID/g) groups. Meanwhile, biodistribution could slightly distinguish the positive from the negative. The results indicated [18F]LN would become an efficient tool for evaluating PD-L1 expression with further optimization.

Extant research documents the valuation effects of credit rating change on the stock price. This study extends the research by examining the information transfer effects of customer credit rating downgrades on supplier firms. We find that supplier firms experience negative abnormal returns during the announcement of customer firms’ rating downgrades. This effect persists over a 50 trading day window after the downgrade announcement. We also find that credit rating deterioration spreads along the supply chain, where the probability of future rating downgrades is significantly higher for supplier firms with downgraded customers. Further, we show that the information transfer effects are associated with certain cross-sectional factors, including the market anticipation of customers rating downgrades, the strength of the customer-supplier linkage, the valuation effects within customer firms’ industries, and investor attention on supplier firms.

Various ZSM-5 zeolites modified with alkali metals (Li, Na, K, Rb, and Cs) were prepared using ion exchange. The catalysts were used to enhance the catalytic dehydration of lactic acid (LA) to acrylic acid (AA). The effects of cationic species on the structures and surface acid-base distributions of the ZSM-5 zeolites were investigated. The important factors that affect the catalytic performance were also identified. The modified ZSM-5 catalysts were characterized using X-ray diffraction, temperature-programmed desorptions of NH 3 and CO 2 , pyridine adsorption spectroscopy, and N 2 adsorption to determine the crystal phase structures, surface acidities and basicities, nature of acid sites, specific surface areas, and pore volumes. The results show that the acid-base sites that are adjusted by alkali-metal species, particularly weak acid-base sites, are mainly responsible for the formation of AA. The KZSM-5 catalyst, in particular, significantly improved LA conversion and AA selectivity because of the synergistic effect of weak acid-base sites. The reaction was conducted at different reaction temperatures and liquid hourly space velocities (LHSVs) to understand the catalyst selectivity for AA and trends in byproduct formation. Approximately 98% LA conversion and 77% AA selectivity were achieved using the KZSM-5 catalyst under the optimum conditions (40 wt% LA aqueous solution, 365 °C, and LHSV 2 h −1 ).

A series of TiO2 supported MnWOx catalysts MnxW0.05Ti0.95 − xO2 − δ (x = 0.05, 0.1, 0.15) were synthesized by solution combustion method. The Mn0.10W0.05Ti0.85O2 − δ catalyst showed highest activity in NH3-SCR reaction within a broad temperature range of 200 °C–400 °C. XRD and TEM results indicate that the active Mn and W species are highly dispersed over TiO2 support in the form of nanoparticles (4–7 nm). The TEM and H2-TPR results also suggest that a MnWOx phase has been formed on the TiO2, which is beneficial for the activity of the MnxW0.05Ti0.95 − xO2 − δ catalysts in the high temperature range of 280 °C–400 °C.

We report a facile and general strategy for the preparation of metallic monolithic catalysts. Our strategy involved subjecting the surfaces of FeCrAl fibers to thermal treatment and the spraying of Pt nanoparticles suspension liquid. The catalyst exhibited high catalytic activity and good stability in the combustion of volatile organic compounds to CO2 and H2O at mild temperature. The exceptional activity of the catalyst can be attributed to the well-adhered alumina coating that formed on the surfaces of the FeCrAl fibers after thermal treatment and the highly dispersed Pt nanoparticles on the surface of the alumina coating.

Lanthanum-transition-metal perovskites with robust meso-scale porous frameworks (meso-LaMO3) are synthesized through the use of ionic liquids. The resultant samples demonstrate a rather high activity for CO oxidation, by taking advantage of unique nanostructure-derived benefits. This synthesis strategy opens up a new opportunity for preparing functional mesoporous complex oxides of various compositions.

Trade credit is the liquidity provision from suppliers to customers. In this paper, we examine the use of trade credit in the supply chain after customer firm's credit rating being downgraded. We find that trade credit is likely to decrease after customers getting downgraded credit ratings. We further show that suppliers and customers will be both better off in profitability if trade credit increases following customers' credit rating downgrades. Given that the use of trade credit generally has a significant positive effect on suppliers' and customers' profitability, we show that this effect is stronger when customers receive credit rating downgrades. The empirical evidence in our paper suggests that strengthening the financial collaborations in the supply chain is a superior strategy relative to shrinking the financial collaborations under the circumstance that customer firms suffer from a growing financial constraint and financial distress.

In order to assess the radioactive impact of Fukushima Incident on the coastal environment of Dapeng Peninsula, Shenzhen, China, combining accelerator mass spectrometry with epithermal neutron activation analysis, we measured the I-129/I-127 ratios and I-129 levels in surface seawater, oyster (Ostrea gigas) and kelp (Sargassum henslouianum). The results showed that the influence of Daya Bay Nuclear Power Base was ignorable to local environment, but the Fukushima Incident had caused significant increase of I-129 levels in oyster (P < 0.001) and kelp (P < 0.05) from Dapeng Peninsula between Jun-2011 and Apr-2012. However, the I-129 levels in oyster and kelp were far below the guideline given by Codex Alimentarius Commission and would not cause immediate harm to the health of local residents.

To improve their thermal stability, La0.8Sr0.2MnO3 cordierite monoliths are washcoated with mayenite, which is a novel Al-based material with the crystal structure of 12MO·7Al2O3 (M = Ca, Sr). The monoliths are characterized by means of nitrogen adsorption/desorption, scanning electron microscopy, and X-ray diffraction. Catalytic performances of the monoliths are tested for methyl methacrylate combustion. The results show that mayenite obviously improves both the physicchemical properties and the catalytic performance of the monoliths. Because mayenite improves the dispersity of La0.8Sr0.2MnO3 and also prevents the interaction between La0.8Sr0.2MnO3 and cordierite or γ-Al2O3, both crystal structure and surface morphology of La0.8Sr0.2MnO3 phase can thereby be stable on the mayenite surface even at high temperature up to 1050 °C. Under the given reaction conditions, La0.8Sr0.2MnO3 monolith washcoated with 12SrO·7Al2O3 shows the best catalytic activity for methyl methacrylate combustion among all the tested monoliths.

A series of Fe-Y zeolite catalysts with different Fe loading were prepared by ferrocene sublimation under solvent and water-free conditions. The dispersion, structure and morphology of the iron species on the Fe-Y catalysts were characterized by XRD, TEM and UV-Vis. The catalytic activities of Fe-Y samples were measured in selective catalytic reduction of NO with ammonia (NH3-SCR). The results showed that the iron species on the HY zeolite support were mainly made up of isolated Fe3+ ions, Fe x O y oligomers and a little amount of < 3 nm spherical Fe2O3 particles. Isolated Fe3+ ions are predominating among all the Fe-Y catalysts. The sum of isolated Fe3+ ions and Fe x O y oligomers took up more than 90% percent of total iron species on the Fe-Y till 10.0 wt% loading of Fe.

ZrO 2 was used as a support for the preparation of Cu–Mn–Ce mixed oxides catalysts (CMC) by impregnation method and calcination at different temperatures. A model reaction, toluene combustion was conducted to evaluate the performance of CMC/ZrO 2 catalysts. High thermal stability and activity was obtained on these catalysts. The effects of CMC loading and calcination temperature on the structure and redox properties of catalysts were also investigated by XRD, H 2 -TPR, TEM and XPS. Results show that calcination leads to the interaction of ZrO 2 and CMC via the formation of a new phase of Zr 0.88 Ce 0.12 O 2 in the interface, which is more likely to be formed in the catalysts with low CMC loading levels. Zr 0.88 Ce 0.12 O 2 seems to function as the actual carrier of active phase of CMC, which cannot only stabilize the surface active structure of CMC but also enhance the mobility of active oxygen and improve the catalytic performance of total oxidation as well.

A monolithic series of Cu-Mn-Ce oxides supported on cordierites with different Cu/Mn/Ce molar ratios were prepared by the in-situ sol-gel method without any binder. The catalysts were characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD), and Brunauer-Emmett-Teller method (BET) and examined in the catalytic combustion of volatile organic compounds (VOCs). The results showed that the well-dispersed nanometer particles of mixed oxides adhered firmly to the cordierite surface. Cu 0.15 Mn 0.3 Ce 55 /cordierite was identified as the most active catalyst. Compared with commercial Pd/Al 2 O 3 , Cu 0.15 Mn 0.3 Ce 55 /cordierite showed higher activities for the combustion of various types of VOCs, especially for oxy-derivative compounds which could be lighted off below 200 °C.

A highly loaded LaMnOx/SBA-15 catalyst (60%) was prepared by step coating NH3/water vapor-induced internal hydrolysis (VIH) and characterized by X-ray diffraction, N2 adsorption-desorption, and temperature-programmed reduction (H2-TPR). Its catalytic performance for toluene combustion was also evaluated. The results showed that the VIH process clearly improved the activity of the LaMnOx/SBA-15 catalyst. Using a toluene concentration of 0.86% and a GHSV of 5000 h−1, a 50% toluene conversion was obtained at 205 °C for the LaMnOx/SBA-15 sample prepared by the VIH process. This temperature was 105 °C lower than that for the sample prepared by conventional impregnation. N2 adsorption-desorption and H2-TPR revealed that the VIH process improved the distribution of the LaMnOx active phase in the pores of SBA-15 and improved its reduction properties. The optimal VIH conditions were a temperature of 60 °C and a reaction time of 40 min.

La0.8Cu0.2MnO3 and La0.8Sr0.2MnO3 perovskite catalysts were prepared by the co-precipitation method. The resistance of these catalysts to sulfur poisoning was tested via catalytic combustion of toluene. The results show that the perovskite catalysts were poisoned in the presence of SO2. In the presence of dodecyl mercaptan (C12H25SH), La0.8Sr0.2MnO3 exhibits better resistance to sulfur poisoning than La0.8Cu0.2MnO3. It was determined that the SO2 deactivation is due to the formation of CuSO4 on the catalyst surface.

The effect of pure and high silica Hβ zeolites on the catalytic performance of toluene combustion over Pd/Hβ catalyst was evaluated. Pure and high silica β zeolites were prepared by direct synthesis procedures, then 0.1 wt% of palladium was impregnated on different Hβ zeolites via incipient wetness technique using palladium nitrate as the Pd source. The Pd/Hβ catalysts were characterized by XRD, N2 adsorption/desorption, H2O adsorption, NH3-TPD, H2-TPR and XPS techniques. With increasing the SiO2/Al2O3 ratio of β zeolite, the activity of the Pd/Hβ catalysts for toluene combustion increased clearly and the pure silica β zeolite supported Pd catalyst showed the best catalytic activity. The superior catalytic performance of Pd/β catalyst prepared from pure silica β zeolite was attributed to its high hydrophobicity and the preserving ability for PdO active species.

Combustive oxidation of volatile organic compounds (VOCs), such as propyl alcohol, toluene and cyclohexane, were studied. The combustion was catalyzed by nanoparticles of La 1− x Sr x CoO 3 ( x = 0, 0.2) perovskites prepared by a co-precipitation method. The results showed high activities of the perovskite catalysts. Compared to LaCoO 3 , in particular, La 0.8 Sr 0.2 CoO 3 was much higher in catalytic ability. The total oxidation of VOCs followed the increasing order: cyclohexane T 99% of cyclohexane was 40 °C lower than that of toluene, which appeared to be determined by the bond strengths of the weakest C–H and C–C bonds. The 100-h stability experiments showed that La 1− x Sr x CoO 3 ( x = 0, 0.2) perovskite was highly stable.