Synthesis and optical property of one-dimensional spinel ZnMn2O4 nanorods

Spinel zinc manganese oxide (ZnMn2O4) nanorods were successfully prepared using the previously synthesized α-MnO2 nanorods by a hydrothermal method as template. The nanorods were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV-Vis absorption, X-ray photoelectron spectroscopy, surface photovoltage spectroscopy, and Fourier transform infrared spectroscopy. The ZnMn2O4 nanorods in well-formed crystallinity and phase purity appeared with the width in 50-100 nm and the length in 1.5-2 μm. They exhibited strong absorption below 500 nm with the threshold edges around 700 nm. A significant photovoltage response in the region below 400 nm could be observed for the nanorods calcined at 650 and 800°C

STUDY ON EARTHQUAKE DAMAGE MECHANISM OF AQUEDUCT STRUCTURE BASED ON DIFFERENT BOUNDARY

Numerically simulating an infinite domain foundation is an important method for solving structural dynamics problems. This paper introduces several artificial dynamic boundaries commonly used in the study of structural dynamics, and elaborates the theory and methods of the dynamic infinite element method boundary (IEMB) and viscous–spring artificial boundary (VSAB). The capacity of different boundary effects on seismic waves energy absorption is verified by establishing a layered half-space model. An irrigation aqueduct is taken as a research object. The IEMB, VSAB, and fixed boundary (FB) models are established and the Concrete Damaged Plasticity (CDP) constitutive is introduced, which is aimed at studying the dynamic failure mechanism and the rules of damage development to the aqueduct structure during the seismic duration. The results for the IEMB and VSAB show better energy absorption for the incident waves and a better simulation result for the damping effect of the far field foundation than that of the FB. Comparing the maximum displacement response rules of the three boundaries, it is seen that the maximum displacement response values of the VSAB and dynamic IEMB increased by 6%–48% and 9%–35%, respectively, over the FB. The calculation results of the VSAB are similar to that of the IEMB. The difference between the maximum acceleration response values is 2%–17% whereas the difference between the maximum displacement response values is 0.4%–19%. The IEMB studied in this paper provides a theoretical reference for large–scale building boundary treatment in structural dynamics calculations

Photonics Crystal Fiber Loop Mirrors and Their Applications\u27

2011-2012 > Academic research: refereed > Chapter in an edited book (author

STUDY ON EARTHQUAKE DESTRUCTION MODE OF THE LARGEST CANAL CROSSING HIGHWAY BRIDGE BASED ON IEM BOUNDARY IN SOUTH-TO-NORTH WATER DIVERSION

  To study the dynamic failure mechanism and damage development law of highway bridge structure under the boundary effect in the process of seismic dynamic duration, the Wenchang Highway Bridge with the largest canal crossing in the South-to-North Water Diversion is taken as an example for seismic design analysis. Based on the finite element and infinite element coupling theory, the infinite element method boundary is introduced, the concrete damage plasticity is introduced, and the half-space free field model is established to study the energy dispersion phenomenon of waves in the boundary and the absorption effect of the infinite element method boundary on wave energy is verified. Under different peak acceleration intensities, the seismic response analysis of the bridge structure was carried out. The results show that: Under the action of selected artificial waves, the damage location of the bridge mainly concentrated in the junction of the box girder supported by the pier, the bottom of the pier and the junction of the pier and beam. The damage tends to develop downward near the bottom of the box girder. The damage at both ends of the beam extends from both ends to the middle. And the bottom and top of the pier have penetrating damage. These are weak points in seismic design. At a horizontal peak acceleration of 0.6g, in addition to damage to the pier column, damage also occurred to the bottom of the box girder. Therefore, when the horizontal peak acceleration of the seismic wave is greater than 0.6g, the failure of the bottom of the box girder is paid attention to. Moreover, the IEM boundary has a good control effect on the far-field energy dissipation of the wave, which is simpler and more efficient than the viscous–spring boundary

Droplet Deposition Pattern Affected by Different Heating Directions

The coffee ring effect commonly exists in droplet deposition patterns, which fundamentally affects scientific research and industrial applications, like pharmaceutical purification, salt manufacturing, etc. Some researchers have tried different solutions to control the distributions of droplet deposition patterns, but most control deposits by adjusting droplet characteristics. In this work, droplet deposition patterns with different wettability are investigated by both localized and substrate heating. A whole process of droplet evaporation is recorded. The droplet generally evaporates from constant contact radius (CCR) mode to constant contact angle (CCA) mode, and CCR stage occupies the most of time. Experimental results show that, without any chemicals, laser induced local heating transitions particle deposition patterns from ring-like structure to dot-like patterns on a hydrophilic surface, driving most saline solvent to the center. Meanwhile, a hydrophobic surface is also investigated showing that the particles tend to assemble at the central area, but the pattern is slightly different compared to that on hydrophilic surface. In addition, physical mechanisms of local heating and heating from substrate are also explored in the present study

Synthesis and Anti-HIV Activity Evaluation of 2-(5-(Naphthalen-1-yl)-1,2,3-thiadiazol-4-ylthio)-N-acetamides Derivatives

The development of novel HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) offers the possibility of generating novel structures of increased potency. Based on the bioisosterism principle, two novel 2-(5-(naphthalen-1-yl)-1,2,3-thiadiazol-4-ylthio)-N-acetamides derivatives have been designed, synthesized and evaluated for their anti-HIV activities in MT-4 cells. The results indicate that these compounds show good activities against HIV-1. Especially, compound 9B (EC50 = 0.019 μM) was more effective than the reference drugs nevirapine and delavirdine.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Design and development of 3D hierarchical ultra-microporous CO2-sieving carbon architectures for potential flow-through CO2 capture at typical practical flue gas temperatures

Developing effective carbon materials for post-combustion CO2 capture (PCC) has received great attentions over many recent years, owing to their desirable adsorption?desorption performance and exceptional thermo-oxidative stability compared to virtually any other capture materials typically the wide array of amine-based sorbent materials. However, due to the nature of physical adsorption, virtually none of the carbon materials reported so far can be practically used for PCC applications without deep flue gas cooling to ambient or even lower temperatures in order to achieve appreciable levels of CO2 uptake capacities at low CO2 partial pressures. Here, we present a category of 3D hierarchical molecular sieving carbon architectures that are able to operate at realistic flue gas temperatures with exceedingly high reversible CO2 capacities. The breakthrough CO2-sieving carbon materials are prepared from using a cost-effective and commercially widely available precursor of polymeric polyisocyanurates with a facile one-step compaction-activation methodology. Tested at sensible flue gas temperatures of 40?70 o C and a low CO2 partial pressure of 0.15 bar, the best performing materials are found to have exceedingly high reversible CO2 capacities of up to 2.30mmol/g at 40 o C and 1.90mmol/g at 70 o C. Advanced characterisations suggest that the unique geometry and chemistry of the easily available precursor material coupled with the characteristics of the compaction-activation protocol used are responsible for the CO2-sieving structures and capacities of the 3D carbon architectures. The findings essentially change the general perception that carbon-based materials can hardly find applications in post-combustion capture due to their low CO2 uptake capacity at low CO2 partial pressures and realistic flue gas temperatures

Discovery, optimization, and target identification of novel coumarin derivatives as HIV-1 reverse transcriptase-associated ribonuclease H inhibitors

Despite significant advances in antiretroviral therapy, acquired immunodeficiency syndrome remains as one of the leading causes of death worldwide. New antiretroviral drugs combined with updated treatment strategies are needed to improve convenience, tolerability, safety, and antiviral efficacy of available therapies. In this work, a focused library of coumarin derivatives was exploited by cell phenotypic screening to discover novel inhibitors of HIV-1 replication. Five compounds (DW-3, DW-4, DW-11, DW-25 and DW-31) showed moderate activity against wild-type and drug-resistant strains of HIV-1 (IIIB and RES056). Four of those molecules were identified as inhibitors of the viral RT-associated RNase H. Structural modification of the most potent DW-3 and DW-4 led to the discovery of compound 8a. This molecule showed increased potency against wild-type HIV-1 strain (EC = 3.94 ± 0.22 μM) and retained activity against a panel of mutant strains, showing EC values ranging from 5.62 μM to 202 μM. In enzymatic assays, 8a was found to inhibit the viral RNase H with an IC of 12.3 μM. Molecular docking studies revealed that 8a could adopt a binding mode similar to that previously reported for other active site HIV-1 RNase H inhibitors.Natural Science Foundation of China (NSFC Nos. 81973181, 81903453), Shandong Provincial Key research and development project (Nos. 2019JZZY021011), Shandong Provincial Natural Science Foundation (ZR2019BH011, ZR2020YQ61, ZR2020JQ31), Foreign cultural and educational experts Project (GXL20200015001), Qilu Young Scholars Program of Shandong University, the Taishan Scholar Program at Shandong Province, and KU Leuven (GOA 10/014). Work in Madrid was supported by the Spanish Ministry of Science and Innovation (grant PID2019-104176RB-I00/AEI/10.13039/501100011033), and an institutional grant of Fundación Ramón Areces (Madrid, Spain)

Investigation of chemical and physical surface changes of thermally conditioned glass fibres

A number of analytical techniques were applied to investigate changes to the surface of unsized boron-free E-glass fibres after thermal conditioning at temperatures up to 700 °C. Novel systematic studies were carried out to investigate the fundamental strength loss from thermal conditioning. Surface chemical changes studied using X-ray photoelectron spectroscopy (XPS) showed a consistent increase in the surface concentration of calcium with increasing conditioning temperature, although this did not correlate well with a loss of fibre strength. Scanning electron microscopy fractography confirmed the difficulty of analysing failure-inducing flaws on individual fibre fracture surfaces. Analysis by atomic force microscopy (AFM) did not reveal any likely surface cracks or flaws of significant dimensions to cause failure: the observation of cracks before fibre fracture may not be possible when using this technique. Fibre surface roughness increased over the whole range of the conditioning temperatures investigated. Although surface roughness did not correlate precisely with fibre strength, there was a clear inverse relationship at temperatures exceeding 400 °C. The interpretation of the surface topography that formed between 400-700 °C produced evidence that the initial stage of phase separation by spinodal decomposition may have occurred at the fibre surface