Graphene oxide (GO) is one typical two-dimension structured and oxygenated planar molecular material. Researchers across multiple disciplines have paid enormous attention to it due to the unique ...physiochemical properties. However, models used to describe the structure of GO are still in dispute and ongoing to update. And currently, synthesis methods for mass production are seemingly abundant but in fact, dominated by a few core methodologies. To update with the state-of-art opinions and progresses, herein we present a mini critical review regarding the synthesis of GO as well as its models and simulations of structure. Also, we discuss the perspectives.
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The Monitoring and Analysis Centre for the fight against money laundering is a valid financial information body which is responsible for collecting, analysing and providing financial information and ...conducting international exchanges of financial information for relevant undertakings. By constructing the analysis of the monitoring of the local and foreign currency and of the data transmission subsystem in the plan for the transitional period against In the light of the above, the Commission will continue to monitor the implementation of the acquis in the light of the progress made in implementing the acquis future new systems. The purpose of this paper is to study the research and implementation of the security control of the anti-money laundering monitoring and analysis system. This article studies the application of decision tree analysis technology in the anti-money laundering monitoring system of insurance companies to achieve the purpose of improving the anti-money laundering monitoring technology and capabilities of insurance companies. The emergence of data mining technology provides a new system solution for anti-money laundering monitoring. For insurance anti-money laundering, how to find potential money laundering cases in suspicious and large surrender transactions is key. The experimental data show that the decision tree method is the best predictor of the customer category between the insurance application and the surrender days. The decision tree analysis technology has greatly improved the security monitoring capabilities of the insurance in the anti-money laundering monitoring system. Experimental data shows that the security control capabilities of the anti-money laundering monitoring and analysis system make the accuracy of the entire model reach 95%, the accuracy of large and suspicious transactions reaches 88.6%, and the correct classification of customers is about 99.6%.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The development of extra‐broadband emitting phosphors is challenging but meaningful work. So far, however, phosphors that can be effectively excited by GaN‐based blue light‐emitting diode (LED) chips ...and emit from visible (VIS) to near‐infrared (NIR) regions are still rare. Herein, this study designs an extra‐broadband VIS‐NIR emitting phosphor with emission band ranging from 460 nm to 880 nm (bandwidth >400 nm) upon 450 nm excitation, owing to an efficient energy transfer from Ce3+ to the red and NIR emitting Mn2+ ions in Lu2BaAl4SiO12 (LBAS) host. By the analysis of extended X‐ray absorption fine structure (EXAFS) spectra and fluorescence lifetimes, it is demonstrated that the NIR emission most probably originates from those Mn2+ occupying the dodecahedral sites with high symmetry rather than the exchange‐coupled Mn2+‐Mn2+ pairs. Furthermore, two single‐phase phosphor‐converted LEDs are fabricated by combining blue LEDs with LBAS:Ce3+,Mn2+ phosphors, and thanks to the extra‐broadband emission, the resultant devices may realize multifunctional applications, such as in high‐quality general lighting, NIR spectroscopy, and plant growth lighting.
The combination of the dual roles of Mn2+ in generating red and near‐infrared (NIR) emission and the efficient energy transfer from Ce3+ to Mn2+ in Lu2BaAl4SiO12 garnet leads to an extra‐broadband visible‐NIR emitting phosphor for multifunctional light‐emitting diode (LED) applications. This study demonstrates that Mn2+ with highly symmetric coordination can efficiently activate broadband NIR phosphors.
While quasi‐two‐dimensional (quasi‐2D) perovskites have emerged as promising semiconductors for light‐emitting diodes (LEDs), the broad‐width distribution of quantum wells hinders their efficient ...energy transfer and electroluminescence performance in blue emission. In particular, the underlying mechanism is closely related to the crystallization kinetics and has yet to be understood. Here for the first time, the influence of bifunctional zwitterions with different coordination affinity on the crystallization kinetics of quasi‐2D perovskites is systematically investigated. The zwitterions can coordinate with Pb2+ and also act as co‐spacer organic species in quasi‐2D perovskites, which collectively inhibit the aggregation of colloidal precursors and shorten the distance of quantum wells. Consequently, restricted nucleation of high‐n phases and promoted growth of low‐n phases are achieved with moderately coordinated zwitterions, leading to the final film with a more concentrated n distribution and improved energy transfer efficiency. It thus enables high‐efficiency blue LEDs with a recorded external quantum efficiency of 15.6% at 490 nm, and the operation stability has also been prolonged to 55.3 min. These results provide useful directions for tuning the crystallization kinetics of quasi‐2D perovskites, which is expected to lead to high‐performance perovskite LEDs.
In this work, a facile strategy base on bifunctional zwitterions is proposed that effectively modulates the crystallization kinetics of quantum wells—both suppressing the formation of low‐n phases and restricting the growth of high‐n phases—contributing to a narrow n distribution. Accordingly, high‐performance sky‐blue PeLEDs at 490 nm with a recorded EQE of 15.6% are realized.
A novel design method of low profile cavity backed planar slot antenna has been described in this paper. The whole antenna including backed cavity and feeding element is completely constructed at a ...single substrate by using substrate integrated waveguide technique and grounded coplanar waveguide. An example with 1.7% bandwidth has been presented, which has 5.4 dBi gain, 16.1 dB front-to-back ratio and -19 dB maximum cross polarized radiation level with its total thickness less than lambda 0 /50. The proposed antenna keeps good radiation performance of conventional cavity backed antenna and has advantages of conventional planar antenna including low profile, light weight, easy fabrication with low cost and convenient integration with planar circuit.
Lanthanide pairs, which can upconvert low energy photons into higher energy photons, are promising for efficient upconversion emission. A typical system with Yb
3+
as a sensitizer can convert short ...NIR into visible/ultraviolet light
via
energy transfer between lanthanide ions. Such upconverting nanocrystals doped with lanthanide ions have found significant potential in bioimaging, photochemical reactions and energy conversion. This review presents a fundamental understanding of energy transfer in lanthanide-supported photon upconversion. We introduce the emerging progress in excitation selection based on the energy transfer within lanthanide ions or activation from antennae, with an outlook in the development and applications of the lanthanide upconversion emissions.
In this review, the various energy transfer pathways involved in lanthanide-related upconversion emissions are comprehensively discussed.
Cesium lead halide (CsPbX3) perovskite has emerged as a promising low‐threshold multicolor laser material; however, realizing wavelength‐tunable lasing output from a single CsPbX3 nanostructure is ...still constrained by integrating different composition. Here, the direct synthesis of composition‐graded CsPbBrxI3−x nanowires (NWs) is reported through vapor‐phase epitaxial growth on mica. The graded composition along the NW, with an increased Br/I from the center to the ends, comes from desynchronized deposition of cesium lead halides and temperature‐controlled anion‐exchange reaction. The graded composition results in varied bandgaps along the NW, which induce a blueshifted emission from the center to the ends. As an efficient gain media, the nanowire exerts position‐dependent lasing performance, with a different color at the ends and center respectively above the threshold. Meanwhile, dual‐color lasing with a wavelength separation of 35 nm is activated simultaneously at a site with an intermediate composition. This position‐dependent dual‐color lasing from a single nanowire makes these metal halide perovskites promising for applications in nanoscale optical devices.
Composition‐graded CsPbBrxI3−x nanowires resulting from desynchronized deposition and anion exchange are efficiently synthesized via vapor‐phase growth. The graded Br/I along the nanowire endows it with tunable emission. Position‐dependent lasing with different colors from the ends and center is detected. Dual‐color lasing is activated simutaneously from the site with an intermediate composition to that of the ends and center.
The unique electronic configuration and structural properties of ceria make ceria‐based nanomaterials such as morphology‐dependent ceria nanocrystals, rare earth‐doped ceria‐zirconia solid solutions ...and noble metal‐ceria nanocomposites effective promoters in three‐way catalysts for low‐temperature water‐gas‐shift reaction, preferential oxidation of traces of CO, the treatment of toxic auto‐mobile exhaust, etc. The activities of nanoceria catalysts can be determined by their morphologies, oxygen vacancies, interfacial structures and the type of exposed crystal surfaces, as well as the synergistic effect exhibited by nanocomposites. In this review, the state‐of‐the‐art developments in the well‐controlled synthesis of ceria‐based nanocatalysts and their applications in both environmental and energy fields is summarized. The involved reaction mechanisms are also briefly introduced, and eventually an outlook in the design of novel nanoceria catalysts for valuable energy applications is addressed.
As the environmental pollution and energy shortage issues become more and more serious, ceria‐based nanomaterials such as well−defined ceria nanocrystals, ceria−zirconia solid solutions, and noble metal−ceria nanocomposites have been the promising candidate catalysts to tackle these urgent problems in effective energy utlization, conversion, and storage as well as environmental remediation.
Metal–organic frameworks (MOFs) have shown great potential as nanophotosensitizers (nPSs) for photodynamic therapy (PDT). The use of such MOFs in PDT, however, is limited by the shallow depth of ...tissue penetration of short-wavelength light and the oxygen-dependent mechanism that renders it inadequate for hypoxic tumors. Here, to combat such limitations, we rationally designed core–shell upconversion nanoparticle@porphyrinic MOFs (UCSs) for combinational therapy against hypoxic tumors. The UCSs were synthesized in high yield through the conditional surface engineering of UCNPs and subsequent seed-mediated growth strategy. The heterostructure allows efficient energy transfer from the UCNP core to the MOF shell, which enables the near-infrared (NIR) light-triggered production of cytotoxic reactive oxygen species. A hypoxia-activated prodrug tirapazamine (TPZ) was encapsulated in nanopores of the MOF shell of the heterostructures to yield the final construct TPZ/UCSs. We demonstrated that TPZ/UCSs represent a promising system for achieving improved cancer treatment in vitro and in vivo via the combination of NIR light-induced PDT and hypoxia-activated chemotherapy. Furthermore, the integration of the nanoplatform with antiprogrammed death-ligand 1 (α-PD-L1) treatment promotes the abscopal effect to completely inhibit the growth of untreated distant tumors by generating specific tumor infiltration of cytotoxic T cells. Collectively, this work highlights a robust nanoplatform for combining NIR light-triggered PDT and hypoxia-activated chemotherapy with immunotherapy to combat the current limitations of tumor treatment.
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