Dalian University of Technology

About: Dalian University of Technology is a education organization based out in Dalian, China. It is known for research contribution in the topics: Catalysis & Finite element method. The organization has 60890 authors who have published 71921 publications receiving 1188356 citations. The organization is also known as: Dàlián Lǐgōng Dàxué.

ZIF-8/ZIF-67-Derived Co-Nx -Embedded 1D Porous Carbon Nanofibers with Graphitic Carbon-Encased Co Nanoparticles as an Efficient Bifunctional Electrocatalyst.

Abstract: Herein, an approach is reported for fabrication of Co-Nx -embedded 1D porous carbon nanofibers (CNFs) with graphitic carbon-encased Co nanoparticles originated from metal-organic frameworks (MOFs), which is further explored as a bifunctional electrocatalyst for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Electrochemical results reveal that the electrocatalyst prepared by pyrolysis at 1000 °C (CoNC-CNF-1000) exhibits excellent catalytic activity toward ORR that favors the four-electron ORR process and outstanding long-term stability with 86% current retention after 40 000 s. Meanwhile, it also shows superior electrocatalytic activity toward OER, reaching a lower potential of 1.68 V at 10 mA cm-2 and a potential gap of 0.88 V between the OER potential (at 10 mA cm-2 ) and the ORR half-wave potential. The ORR and OER performance of CoNC-CNF-1000 have outperformed commercial Pt/C and most nonprecious-metal catalysts reported to date. The remarkable ORR and OER catalytic performance can be mainly attributable to the unique 1D structure, such as higher graphitization degree beneficial for electronic mobility, hierarchical porosity facilitating the mass transport, and highly dispersed CoNx C active sites functionalized carbon framework. This strategy will shed light on the development of other MOF-based carbon nanofibers for energy storage and electrochemical devices.

An Off–On COX-2-Specific Fluorescent Probe: Targeting the Golgi Apparatus of Cancer Cells

Abstract: Identifying cancer cells and quantifying cancer-related events in particular organelles in a rapid and sensitive fashion are important for early diagnosis and for studies on pathology and therapeutics of cancers. Herein a smart “off–on” cyclooxygenase-2-specific fluorescence probe (ANQ-IMC-6), able to report the presence of cancer cells and to image Golgi-related events, has been designed and evaluated. Cyclooxygenase-2 (COX-2) has been used as imaging target in the probe design, since this enzyme is a biomarker of virtually all cancer cell lines. In the free state in aqueous solution, ANQ-IMC-6 mainly exists in a folded conformation where probe fluorescence is quenched through photoinduced electron transfer between the fluorophore acenaphtho[1,2-b]quinoxaline (ANQ) and the recognition group, indomethacin (IMC). Fluorescence is turned on, by restraining the photoinduced electron transfer, when ANQ-IMC-6 is forced to adopt the unfolded state following binding to COX-2 in the Golgi apparatus of cancer cells...

3D Architecture Materials Made of NiCoAl-LDH Nanoplates Coupled with NiCo-Carbonate Hydroxide Nanowires Grown on Flexible Graphite Paper for Asymmetric Supercapacitors

Abstract: Asymmetric supercapacitors featuring both high energy and power densities as well as a long lifespan are much sought after and may become a reality depending on the availability of cheap yet highly active electrode materials. Here, a novel flexible architecture electrode made of NiCoAl-layered double hydroxide (NiCoAl-LDH) nanoplates coupled with NiCo-carbonate hydroxide (NiCo-CH) nanowires, grown on graphite paper via an in situ, one-step, hydrothermal method is reported. The nanowire-like NiCo-CH species in the nanoplate matrix function as a scaffold and support the dispersion of the NiCoAl-LDH nanoplates, resulting in a relatively loose and open structure within the electrode matrix. Asymmetric supercapacitors fabricated using the nanohybrids as the positive electrode and a typical activated carbon (AC) as negative electrode show a high energy density of 58.9 Wh kg−1 at a power density of 0.4 kW kg−1, which is based on the total mass of active materials at a voltage of 1.6 V. An energy density of 14.9 Wh kg−1 can be retained even at a high power density of 51.5 kW kg−1. Our asymmetric supercapacitor also exhibits an excellent long cycle life, whereby a specific capacitance of 97% is retained even after 10 000 cycles.

Theoretical prediction and numerical simulation of multi-cell square thin-walled structures

Abstract: The axial crushing of square multi-cell columns were studied analytically and numerically. Based on the Super Folding Element theory, a theoretical solution for the mean crushing force of multi-cell sections were derived by dividing the profile into 3 parts: corner, crisscross, and T-shape. Numerical simulations of square multi-cell sections subjected to dynamic axial crushing were conducted and an enhancement coefficient was introduced to account for the inertia effects for aluminum alloy AA6060 T4. The analytical solutions show an excellent agreement with the numerical results. It was found that the crisscross part was the most efficient component for energy absorption and the energy absorption efficiency of a single-cell column can be increased by 50% when the section was divided into 3×3 cells. Finally, the proposed method was extended to analyze the plateau stress of square cell honeycomb subjected to out-plane axial crushing and to some extent validate the mechanical insensitivity of honeycomb to cell size.

Aquatic photochemistry of fluoroquinolone antibiotics: kinetics, pathways, and multivariate effects of main water constituents.

Abstract: The ubiquity of fluoroquinolone antibiotics (FQs) in surface waters urges insights into their fate in the aqueous euphotic zone. In this study, eight FQs (ciprofloxacin, danofloxacin, levofloxacin, sarafloxacin, difloxacin, enrofloxacin, gatifloxacin, and balofloxacin) were exposed to simulated sunlight, and their photodegradation was observed to follow apparent first-order kinetics. Based on the determined photolytic quantum yields, solar photodegradation half-lives for the FQs in pure water and at 45 degrees N latitude were calculated to range from 1.25 min for enrofloxacin to 58.0 min for balofloxacin, suggesting that FQs would intrinsically photodegrade fast in sunlit surface waters. However, we found freshwater and seawater constituents inhibited their photodegradation. The inhibition was further explored by a central composite design using sarafloxacin and gatifloxacin as representatives. Humic acids (HA), Fe(III), NO(3)(-), and HA-Cl(-) interaction inhibited the photodegradation, as they mainly acted as radiation filters and/or scavengers for reactive oxygen species. The photodegradation product identification and ROS scavenging experiments indicated that the FQs underwent both direct photolysis and self-sensitized photo-oxidation via *OH and (1)O(2). Piperazinyl N(4)-dealkylation was primary for N(4)-alkylated FQs, whereas decarboxylation and defluorination were comparatively important for the other FQs. These results are of importance toward the goal of assessing the persistence of FQs in surface waters.