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A high-aluminum-content sulfated zirconia was prepared by the kneading method, and the washing process was considered as a key factor. Catalysts were characterized by XRD, BET analysis, SEM, TG, FT-IR spectroscopy, pyridine IR spectroscopy, NH3 TPD, H2 TPR, and 27Al NMR spectroscopy, and the reactivity was evaluated by n-hexane isomerization. The results showed that the high-aluminum-content sulfated zirconia has a high activity after being washed with water. Moreover, the aluminum content was found to strongly influence the crystal form, catalyst structure, and acidity, as well as the anchoring effect on the labile sulfates. Actually, the higher the aluminum content was, the more sulfates were left in the catalyst samples after washing. The O--H and S=O stretching vibrations were shifted in the presence of aluminum or water. With the support of the aluminum coordination state, a hydrolysis model was deduced for different aluminum contents in the catalysts, and it can explain the formation of more Brønsted acid sites and Al--O--S bonds. [ABSTRACT FROM AUTHOR]

The human cornea, consisting of five layers, is the transparent tissue that refracts and transmits light to the lens and retina, providing about two thirds of the refractive power of the eye. The stroma layer comprises nearly 90 % of the thickness of the cornea and thus plays a pivotal role in normal visual function. The bulk of this layer is constituted by proteins in the extracellular martrix secreted by the corneal epithelial, stroma, and endothelial cells. Clinical research has shown that corneal stroma diseases are common and involve conditions such as infections, injuries, and genetic defects, which cause severe visual disturbances or even blindness. To improve our understanding of the basic molecular mechanisms involved in the physiological and pathological activities of the corneal stroma, its proteins have been brought into the limelight to determine their crucial and irreplaceable roles. The data presented in a previous study have demonstrated the presence of 1679 proteins in the stroma, and this data set has subsequently been perfected by utilizing a highly sensitive isobaric peptide-labeling approach. According to their manifestations, these proteins can be classified as a gel-like organic material composed of proteoglycans, enzymes, and hemocyanin-binding proteins and a network of filaments composed of collagen, elastin, keratin, vimentin, and interconnected filaments comprising fibronectin and laminin. The aim of this review is to describe some corneal stroma proteins by highlighting their major functions and valuable applications in ophthalmologic research toward the better characterization and treatment of eye diseases. [ABSTRACT FROM AUTHOR]

The influence of a directly adjacent or an anisotropic surrounding medium alters the plasmonic properties of a nanoparticle because it provides a mechanism for symmetry breaking of the scattering. Given the success of ion irradiation induced embedment of rigid metallic nanospheroids into amorphous substrate, it is possible to examine the effect of the silica glass substrate on the plasmonic properties of these embedded nanospheroids. In this work presented here, discrete dipole approximation (DDA) calculations for the Au nanospheroids' optical properties were performed based on 3-dimensional (3D) configuration extracted from planar SEM micrographs and cross-sectional TEM micrographs of the Au nanospheroids partially embedded in the silica glass, and the well-matched simulations with respect to the experimental measurements could demonstrate the dielectric constant at the near surface of silica glass decreased after Ar-ion irradiation. [ABSTRACT FROM AUTHOR]

Abnormalities in the TP53 gene and overexpression of MDM2, a transcriptional target and negative regulator of p53, are commonly observed in cancers. The MDM2-p53 feedback loop plays an important role in tumor progression and thus, increased understanding of the pathway has the potential to improve clinical outcomes for cancer patients. Hepatocellular carcinoma (HCC) has emerged as one of the most commonly diagnosed forms of human cancer; yet, the current treatment for HCC is less effective than those used against other cancers. We review the current studies of the MDM2-p53 pathway in cancer with a focus on HCC and specifically discuss the impact of p53 mutations along with other alterations of the MDM2-p53 feedback loop in HCC.Wealso discuss the potential diagnostic and prognostic applications of p53 and MDM2 in malignant tumors as well as therapeutic avenues that are being developed to target the MDM2-p53 pathway. [ABSTRACT FROM AUTHOR]

Catalyst breakdown by physical attrition and chemicalstressesis a problem of great and continuing concern in the slurry phase Fischer–TropschSynthesis. To reach a better understanding of the morphology and compositionof a working catalyst, it requires first the removal of wax from thecatalyst. In this work, Improved Soxhlet Extraction (ISE) in comparisonof Standard Soxhlet Extraction was evaluated concerning their separationefficiency and relevancy for characterization of working catalysts.ISE extracted a greater amount of wax and recovered nearly all ofthe catalyst. In addition, ISE does not change the morphology andparticle size distribution of working catalysts whereas Soxhlet extractionfails to reflect the actual information on the catalyst. The ISE isappropriate for the rapid and accurate analysis in plant operation. [ABSTRACT FROM AUTHOR]

This work mainly involved the investigation of the adsorption of propylmercaptan (PM) on modified bentonite adsorbents. The adsorbents were prepared by loading it separately with Cu2+, Cu+, Fe3+, and MnO4–. In general, these bentonite adsorbents tested for sulfur adsorption capacity at breakthrough followed the order: KMnO4–bentonite > Cu(I)–bentonite > Cu(II)–bentonite > Fe(III)–bentonite. Several factors that influence the desulfurization capability, including loading and baking temperature, were investigated. The results of X-ray diffraction (XRD), nitrogen sorption (BET), thermal analysis (TGA), and Fourier transform infrared (FT-IR) spectroscopy showed that the ability of modified bentonite to adsorb PM depends strongly on its surface chemistry, particularly on the presence of basic oxygen-containing groups and acid content. The high sulfur capacities of KMnO4–bentonite and Fe(III)–bentonite were because of the powerful oxidization of MnO4–and Fe3+. The high sulfur capacities of Cu(I)–bentonite and Cu(II)–bentonite were due to π-complexation. [ABSTRACT FROM AUTHOR]

Ion irradiation and short-pulsed laser irradiation can be used to form nanostructures on the surfaces of substrates. This work investigates the synergistic effects of ion and nanosecond-pulsed laser co-irradiation on surface nanostructuring of Au thin films deposited under vacuum on SiO2 glass substrates. Gold nanoparticles are randomly formed on the surface of the substrate after nanosecond-pulsed laser irradiation under vacuum at a wavelength of 532 nm with a repetition rate of 10 Hz and laser energy density of 0.124 kJ/m2. Gold nanoparticles are also randomly formed on the substrate after 100-keV Ar+ ion irradiation at doses of up to 3.8×1015 ions/cm2, and nearly all of these nanoparticles are fully embedded in the substrate. With increasing ion irradiation dose (number of incident laser pulses), the mean diameter of the Au nanoparticles decreases (increases). However, Au nanoparticles are only formed in a periodic surface arrangement after co-irradiation with 6000 laser pulses and 3.8×1015 ions/cm2. The periodic distance is ∼540 nm, which is close to the wavelength of the nanosecond-pulsed laser, and the mean diameter of the Au nanoparticles remains at ∼20 nm with a relatively narrow distribution. The photoabsorption peaks of the ion- or nanosecond-pulsed laser-irradiated samples clearly correspond to the mean diameter of Au nanoparticles. Conversely, the photoabsorption peaks for the co-irradiated samples do not depend on the mean nanoparticle diameter. This lack of dependence is likely caused by the periodic nanostructure formed on the surface by the synergistic effects of co-irradiation. [ABSTRACT FROM AUTHOR]

The treatment of a β zeolite with sodium hydroxide solution can partially desilicate the β zeolite, thereby obtaining a mesoporous structure. The isomerization of α-pinene has been studied at 403 K and under atmospheric pressure. The catalytic materials were characterized by XRD, SEM, BET analysis, FT-IR spectroscopy and Py-IR spectroscopy. The results show that the pore structure of the β zeolite can be effectively regulated by the sodium hydroxide solution. The microporous structure of the β zeolite was destroyed. The crystallinity changed, the number of mesopores increased and the amount of acid slightly decreased. The catalyst after alkali treatment was applied to the isomerization reaction of α-pinene. The conversion of α-pinene increased to 96%, and the yield of camphene and limonene reached 67%. It was found that the isomerization reaction of α-pinene on the β zeolite followed the first-order reaction kinetics, and the activation energy of the reaction was 41.58 kJ mol-1. [ABSTRACT FROM AUTHOR]

To evaluate the frequency and associated factors of artifacts in swept-source optical coherence tomography (SS-OCT) imaging. This was a population-based cross-sectional study. Individuals aged 35 years or older, residing in the Yuexiu district of Guangzhou, China, were recruited by random cluster sampling. Nearly half of the participants were randomly selected for SS-OCT imaging centered on the optic nerve head. Six types of artifacts in the peripapillary choroidal layer and retinal nerve fiber layer (RNFL) were graded and identified. Univariate and multivariate logistic regression analyses were used to investigate the association between the presence of artifacts and clinical characteristics. Out of the 616 eligible individuals who underwent SS-OCT imaging, 18.3% and 13.6% of subjects exhibited at least one artifact in peripapillary RNFL (pRNFL) and peripapillary choroidal thickness (pCT) measurements, respectively, with posterior segmentation error and off-center artifact ranked as the most common artifacts. The presence of artifacts was significantly associated with age (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.01–1.06; p =.003), refractive error (OR, 0.80; 95% CI, 0.71–0.89; p <.001), and signal strength (OR, 0.95; 95% CI, 0.90–0.997; p =.039) in pRNFL thickness measurement. Similarly, the presence of artifacts in pCT measurement was significantly associated with age (OR, 1.05; 95% CI, 1.03–1.08; p <.001), and refractive error (OR, 0.76; 95% CI, 0.68–0.86; p <.001). Nearly one-fifth of the eyes were noted with at least one artifact in the population-scale SS-OCT study. Age was a risk factor for the presence of artifacts and should be considered in clinical settings. [ABSTRACT FROM AUTHOR]

Introduction: Axial length (AL) elongation in myopia is considered irreversible. We aimed to systemically report unexpected AL shortening observed in a randomized clinical trial (RCT) after repeated low-level red-light (RLRL) therapy. Methods: This is a post hoc analysis of a multicenter, single-masked RCT. Two hundred sixty-four myopic children aged 8–13 years allocated to RLRL treatment (intervention group) or a single vision spectacle (SVS, control group) were included. AL was measured using an IOL-master 500 at baseline, 1-, 3-, 6-, and 12-month follow-up visits. AL shortening was defined as AL reduction from baseline to follow-up visits at three cutoffs: > 0.05 mm, > 0.10 mm, and > 0.20 mm. Frequency of AL shortening at different cutoffs was calculated. Analysis was done with intent to treat (ITT). Results: At 12-months follow up, frequency of AL shortening > 0.05 mm was 26/119 (21.85%) and 2/145 (1.38%) for the RLRL group versus the control group, respectively. The frequency was 18/119 (15.13%) versus 0/145 (0%) for AL shortening > 0.10 mm, and 7/119 (5.88%) versus 0/145 (0%), for AL shortening > 0.20 mm, respectively (p < 0.001). Mean AL shortening after 12 months (SD) was −0.156 (0.086) mm in the RLRL group and −0.06 mm in the control group. Age was significantly associated with AL shortening in the multivariable analysis. For the RLRL group that exhibited AL shortening (n = 56), choroidal thickness (ChT) thickening (0.056 mm) could only explain 28.3% of AL shortening (−0.20 mm). Conclusion: Nearly a quarter of children had > 0.05 mm AL shortening following 12 months of RLRL therapy, whereas AL shortening rarely occurred among controls. Trial Registration: ClinicalTrials.gov (NCT04073238). [ABSTRACT FROM AUTHOR]

Introduction: Myopia is recognized as a progressive eye disease. The aim of this study was to evaluate the frequency and associated factors of clinically significant axial length (AL) shortening among myopic children following repeated low-level red light (RLRL) therapy. Methods: The clinical data that were collected for the myopic children aged 3–17 years who received an RLRL therapy delivered by home-use desktop light device that emitted light at 650 nm for at least 1 year, were reviewed. The clinical data included AL, spherical equivalent refraction (SER), and visual acuity measured at baseline and follow-up. The primary outcomes were frequency of AL shortening of > 0.05 mm, > 0.10 mm, and > 0.20 mm per year, and associated factors of AL shortening per year. Results: A total of 434 myopic children with at least 12 months of follow-up data were included. The mean age of participants was 9.7 (2.6) years with SER of −3.74 (2.60) diopters. There were 115 (26.50%), 76 (17.51%), and 20 (4.61%) children with AL shortening based on cutoffs of 0.05 mm/year, 0.10 mm/year, and 0.20 mm/year, respectively. In the multivariable model, AL shortening was significantly associated with older baseline age, female gender, and longer baseline AL or greater spherical equivalent refraction (all P < 0.05). Among AL shortened eyes, the mean AL difference (standard deviation, SD) was −0.142 (0.094) mm/year. Greater AL shortening was observed among children who were younger and had longer baseline AL (all P < 0.05). Conclusions: More than a quarter of children had AL shortening > 0.05 mm following RLRL therapy, and the overall mean AL change was −0.142 mm/year. Further studies should explore the mechanisms underlying AL shortening. [ABSTRACT FROM AUTHOR]

To evaluate longitudinal changes in macular choroidal thickness (mCT) in myopic children treated for 1 year with repeated low-level red-light (RLRL) therapy and their predictive value for treatment efficacy on myopia control. A secondary analysis of data from a multicenter, randomized controlled trial (RCT; NCT04073238). Myopic children aged 8–13 years who participated in the RCT at 2 of 5 sites where mCT measurements were available. Repeated low-level red-light therapy was delivered using a home-use desktop light device that emitted red-light at 650 nm. Choroidal thickness was measured by SS-OCT at baseline and 1-, 3-, 6-, and 12-month follow-ups. Visual acuity, axial length (AL), cycloplegic spherical equivalent refraction (SER), and treatment compliance were measured. Changes in mCT at 1, 3, 6, and 12 months relative to baseline, and their associations with myopia control. A total of 120 children were included in the analysis (RLRL group: n = 60; single-vision spectacle [SVS] group: n = 60). Baseline characteristics were well balanced between the 2 groups. In the RLRL group, changes in mCT from baseline remained positive over 1 year, with a maximal increase of 14.755 μm at 1 month and gradually decreasing from 5.286 μm at 3 months to 1.543 μm at 6 months, finally reaching 9.089 μm at 12 months. In the SVS group, mCT thinning was observed, with changes from baseline of –1.111, –8.212, –10.190, and –10.407 μm at 1, 3, 6, and 12 months, respectively. Satisfactory myopia control was defined as annual progression rates of less than 0, 0.05, or 0.10 mm for AL and less than 0, 0.25, or 0.50 diopters for SER. Models that included mCT changes at 3 months alone had acceptable predictive discrimination of satisfactory myopia control over 12 months, with areas under the curve of 0.710–0.786. The predictive performance of the models did not significantly improve after adding age, gender, and baseline AL or SER. This analysis from a multicenter RCT found RLRL induced sustained choroidal thickening over the full course of treatment. Macular choroidal thickness changes at 3 months alone can predict 12-month myopia control efficacy with reasonable accuracy. Proprietary or commercial disclosure may be found after the references. [ABSTRACT FROM AUTHOR]

Background: To evaluate the long‐term efficacy and safety of continued repeated low‐level red‐light (RLRL) therapy on myopia control over 2 years, and the potential rebound effect after treatment cessation. Methods: The Chinese myopic children who originally completed the one‐year randomised controlled trial were enrolled. Children continued RLRL‐therapy were defined as RLRL‐RLRL group, while those who stopped and switched to single‐vision spectacle (SVS) in the second year were RLRL‐SVS group. Likewise, those who continued to merely wear SVS or received additional RLRL‐therapy were SVS‐SVS and SVS‐RLRL groups, respectively. RLRL‐therapy was provided by an at‐home desktop light device emitting red‐light of 650 nm and was administered for 3 min at a time, twice a day and 5 days per week. Changes in axial length (AL) and cycloplegic spherical equivalence refraction (SER) were measured. Results: Among the 199 children who were eligible, 138 (69.3%) children attended the examination and 114 (57.3%) were analysed (SVS‐SVS: n = 41; SVS‐RLRL: n = 10; RLRL‐SVS: n = 52; RLRL‐RLRL: n = 11). The baseline characteristics were balanced among four groups. In the second year, the mean changes in AL were 0.28 ± 0.14 mm, 0.05 ± 0.24 mm, 0.42 ± 0.20 mm and 0.12 ± 0.16 mm in SVS‐SVS, SVS‐RLRL, RLRL‐SVS and RLRL‐RLRL group, respectively (p < 0.001). The respective mean SER changes were −0.54 ± 0.39D, −0.09 ± 0.55D, −0.91 ± 0.48D, and −0.20 ± 0.56D (p < 0.001). Over the 2‐year period, axial elongation and SER progression were smallest in RLRL‐RLRL group (AL: 0.16 ± 0.37 mm; SER: −0.31 ± 0.79D), followed by SVS‐RLRL (AL: 0.44 ± 0.37 mm; SER: −0.96 ± 0.70D), RLRL‐SVS (AL: 0.50 ± 0.28 mm; SER: −1.07 ± 0.69D) and SVS‐SVS group (AL: 0.64 ± 0.29 mm; SER: −1.24 ± 0.63D). No self‐reported adverse events, functional or structural damages were noted. Conclusions: Continued RLRL therapy sustained promising efficacy and safety in slowing myopia progression over 2 years. A modest rebound effect was noted after treatment cessation. [ABSTRACT FROM AUTHOR]

Aiming at the common existing problems of traditional detecting methods for emulsion concentration such as needing manual sampling, having a lag and low measuring accuracy, the image of the light incident to the emulsion was studied. A kind of special detection system based on the principle of the total reflection of light was put forward. The image's geometric model was established. The relationship between the characteristic parameters and the emulsion concentration was researched. A variety of different concentration emulsion was detected using the relationship. The results indicate that the precision of the online detection method based on image processing can reach 0.001% and has higher precision and reliability compared with the traditional detection method's precision of 0.5%. The detection scheme overcomes the shortcomings of traditional detection methods and has a good practicability through experimental verification. [ABSTRACT FROM AUTHOR]

Exploring reliable hydrogenation catalysts to remove trace olefins in aromatic hydrocarbons through hydrogenation is an important topic. In this paper, a bimetallic Cu-Ru/montmorillonite (Cu-Ru/M) catalyst was prepared using a step-by-step impregnation method, and the effects of bimetallic catalysts on removing olefins were assessed. The catalysts were characterized using X-ray diffraction, Brunauer-Emmett-Teller specific surface area, inductively coupled plasma atomic emission spectrometry, high-resolution transmission electron microscopy and temperature-programmed reduction of H2. The results show that there is a strong interaction between Cu and Ru on the Cu-Ru/M catalyst, which improves the dispersion of the metals on the surface of the support M. The hydrogen spillover phenomenon of Cu-Ru/M enhances its activity and adsorption capacity for hydrogen species. The catalytic performance test confirmed that the bimetallic catalyst has significantly greater activity and stability. The optimal loadings are 5% copper and 1% ruthenium, and the performance of this catalyst is comparable to those of noble-metal Pt/M catalysts. [ABSTRACT FROM AUTHOR]

In order to improve the removal efficiency of clays in oil refining, to explore the related factors and to clarify the removal mechanism of alkaline nitride, a series of modified clays was prepared to test removal of alkaline nitride from lubricating oil. After the addition of 1 wt.% FeCl3, the removal rate of alkaline nitride increased from 33.6% to 43.3%. Furthermore, the acidity and chlorine content did not exceed acceptable levels. The testing methods of N2 adsorption-desorption, particle-size distribution, Fourier-transform infrared spectroscopy and X-ray diffraction were conducted to verify the removal mechanism. The removal rate of alkaline nitride is mainly related to the density of Lewis acid sites. The Fourier-transform infrared spectra confirmed the existence of the complexation reaction. The basic nitrides were removed by chemical adsorption via Fe3+-complexation. [ABSTRACT FROM AUTHOR]

The aim of this multicenter study was to demonstrate the distribution pattern of atherosclerotic stenosis and its trend with aging between extracranial and intracranial arteries and its distribution between the anterior and posterior circulations in Chinese patients hospitalized with ischemic stroke. In addition, the risk factors for the distribution pattern were illustrated. From June 2015 to May 2016, 9,346 patients with ischemic stroke from 20 hospitals were enrolled. Carotid artery ultrasonography and transcranial color-coded sonography/transcranial Doppler were used to evaluate the extracranial and intracranial arteries. The distribution pattern of atherosclerotic stenosis and its trend with aging were analyzed. Logistic regression was used to analyze the risk factors for the distribution pattern. Among the 9,346 patients, 2,882 patients (30.8%) had at least one artery with a degree of stenosis =50%. Among patients with arterial stenosis, the proportion of patients with intracranial artery stenosis was higher than those with extracranial artery stenosis (52.6% vs. 27.6%), and the proportion of anterior circulation artery stenosis was higher than that in the posterior circulation (52.2% vs.26.2%). With aging, the proportion of intracranial artery stenosis alone decreased; at the same time, the proportion of extracranial artery stenosis and extracranial plus intracranial artery stenosis increased (trend Χ²=6.698, P=0.001). Hypertension (OR 1.416, P=0.008) and family history of stroke (OR 1.479, P=0.014) were risk factors for intracranial artery stenosis. Male, aging, and smoking were factors more related to extracranial artery stenosis. Aging (OR 1.022, P<0.001) and hypertension (OR 1.392, P=0.019) were related to posterior circulation artery stenosis. Intracranial arteries and anterior circulation arteries were susceptible to stenosis in Chinese patients with ischemic stroke. However, the distribution pattern of atherosclerotic stenosis was dynamic and varied with aging. Aging and different risk factors contribute to this distribution pattern. [ABSTRACT FROM AUTHOR]

Background and aims Vascular peroxidase 1 (VPO1) plays a key role in mediation of cardiovascular oxidative injury. This study aims to determine whether VPO1 can promote programmed necrosis of endothelial cells and the underlying mechanisms. Methods and results Human umbilical vein endothelial cells (HUVECs) were incubated with oxidized low-density lipoprotein (ox-LDL, 100 μg/mL) for 48 h to induce cell injury, which showed an elevation in cell necrosis (reflected by the increased propidium iodide (PI) positive-staining cells, LDH release and decreased cell viability), concomitant with an increase in programmed necrosis-relevant proteins including receptor-interacting protein kinase 1/3 (RIPK1/3), p-RIPK3 and mixed lineage kinase domain like (MLKL); these phenomena were attenuated by necrostatin-1(Nec-1) and RIPK3 siRNA. Meanwhile, VPO1 was up-regulated in ox-LDL-treated endothelial cells accompanied by a decrease in GSK-3β activity and p-β-catenin levels, and an elevation of β-catenin levels; these phenomena were reversed in the presence of VPO1 siRNA or hypochlorous acid (HOCl) inhibitor; replacement of ox-LDL with HOCl could also induce endothelial programmed necrosis and activate the β-catenin signaling; β-catenin inhibitor could also suppress ox-LDL-induced RIPK-dependent necrosis. In hyperlipidemic patients, the plasma level of VPO1 was obviously increased concomitant with an elevation in plasma levels of RIPK1, RIPK3 and MLKL, and they were positively correlated. Conclusions VPO1 plays an important role in promotion of endothelial programmed necrosis under hyperlipidemic conditions through activation of β-catenin signaling. It may serve as a novel therapeutic target for prevention of endothelial dysfunction in hyperlipidemia. [ABSTRACT FROM AUTHOR]

Sulfated zirconia was synthesized by a one step solvent-free method, directly mixing Zr(OH)4 and (NH4)2SO4. The entire synthesis process produces no wastewater, which is environmentally friendly. The synthesis factor (mole ratio of (NH4)2SO4:Zr(OH)4) is the main point to test catalytic activity. Structural properties are characterized by X-ray diffraction (XRD), N2 adsorption-desorption isotherms, and inductively coupled plasma (ICP). The acid property is characterized by pyridine-FTIR. The S coverage (x10-6 mol S•m-2)-Lewis acidic sites density (mmol•m-2) relationship in sulfated zirconia reveals that the generation order of Lewis acidic sites is from weak ones to strong ones. Calculation of acid property reveals the positive structural-functional relationship (WL/SL-catalytic activity). Weak Lewis acidic sites (WL) promote the activity toward removal olefins, while strong Lewis acidic sites (SL) speed up the deactivation of catalysts. The superior catalytic performance as well as environmentally friendly synthesis method demonstrates that solvent-free sulfated zirconia has bright application prospects in industry. [ABSTRACT FROM AUTHOR]

For the postprocessing of the spectral image of a microwave burst observed by the PMO solar fast spectrometer at 4.5–7.5 GHz, we have used various image-processing methods to remove noise and interference, to make the image reflect better the burst event, and to intensify the more interesting details. The software is developed on the platform of MATLAB with good results. [Copyright &y& Elsevier]

A broadband solar radio spectrometer with a bandwidth of about 7 GHz has been developed in China for solar maximum 23. This work is a cooperative project of Beijing Astronomical Observatory (BAO), Purple Mountain Observatory (PMO), Yunnan Observatory (YNO), and Nanjing University. The spectrometer of PMO worked in the waveband of 4.5–7.5 GHz, that of BAO in 1–2 GHz, 2.6–3.8 GHz, and 5.2–7.6 GHz, and that of YNO in 0.7–1.5 GHz. The spectrometer of PMO is a multichannel and frequency-agile one with a time resolution of 1–5 ms and a frequency resolution of 10 MHz. It started to operate in August 1999 and since then more than 300 spectral events have been observed, and some type III or type III-like structures have also been found. In this paper, some selected typical events, for example, the events on 25 August 1999 and 27 October 1999, are presented, and some new observed features are also described and discussed. [ABSTRACT FROM AUTHOR]

The in situ observation of Au dot formation and the self-assembly dynamics of Au nanoparticles (NPs) was successfully demonstrated via dewetting of Au thin films on SiO2 glass substrates under nano-second pulsed laser irradiation using a multi-quantum beam high-voltage electron microscope. Moreover, using electron energy-loss spectroscopy (EELS) performed in a scanning transmission electron microscope (STEM), the plasmonic properties of the formed Au/SiO2 nanostructure were analyzed to demonstrate its validity in advanced optical devices. The uniformly distributed Au NPs evolved into a dot alignment through movement and coalescence processes was demonstrated in this in situ observation. We carried out the plasmon-loss images of the plan view and the cross-section of the Au/SiO2 nanostructures were obtained at the plasmon-loss peak energy for investigate the three-dimensional distribution of surface plasmon. Furthermore, discrete-dipole approximation (DDA) calculations were used to simulate the plasmonic properties, such as the surface plasmon resonance and the surface plasmon field distribution, of isolated single Au/SiO2 nanostructures. This STEM-EELS-acquired surface plasmon map of the cross-sectional sample is in excellent agreement with the DDA calculations. This results demonstrated the influence of the contact condition between Au NP and SiO2 glass on the plasmonic properties, and may improve the technology for developing advanced optical devices. [ABSTRACT FROM AUTHOR]