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Wadsley-Roth phase titanium niobium oxides have received considerable interest as anodes for lithium ion batteries. However, the volume expansion and sluggish ion/electron transport kinetics retard its application in grid scale. Here, fast and durable lithium storage in entropy-stabilized Fe0.4Ti1.6Nb10O28.8 (FTNO) is enabled by tuning entropy via Fe substitution. By increasing the entropy, a reduction of the calcination temperature to form a phase pure material is achieved, leading to a reduced grain size and, therefore, a shortening of Li+ pathway along the diffusion channels. Furthermore, in situ X-ray diffraction reveals that the increased entropy leads to the decreased expansion along a-axis, which stabilizes the lithium intercalation channel. Density functional theory modeling indicates the origin to be the more stable Fe-O bond as compared to Ti-O bond. As a result, the rate performance is significantly enhanced exhibiting a reversible capacity of 73.7 mAh g(-1) at 50 C for FTNO as compared to 37.9 mAh g(-1) for its TNO counterpart. Besides, durable cycling is achieved by FTNO, which delivers a discharge capacity of 130.0 mAh g(-1) after 6000 cycles at 10 C. Finally, the potential impact for practical application of FTNO anodes has been demonstrated by successfully constructing fast charging and stable LiFePO4||FTNO full cells.

Physicochemical and electrochemical properties of hydroxyphenyl boronic acids(HPBAs) and their use in fluoride determinations were investigated. HPBAs were electropolymerized at pH 1.0-11.0 in 40-60 %(v/v) methanol-buffer. Differential pulse voltammetry(DPV) determinations of fluoride (with 1.0x10(-5)-1.0x10(-4) M linearity based on potential shift) using poly(HPBAs) glassy carbon electrodes(GCEs) have -45.49 to +34.40 % error range. Significance of raw DPV data for chemometric discrimination was investigated by principle component analysis. This is the first demonstration of fluoride determination with poly(HPBAs)GCEs and chemometric discrimination of pharmaceutical formulations so far. Due to the lack of experimental data in literature, current findings will make a contribution to literature., National Boron Research Institute (BOREN) [BOREN2008-C0138]; University of Ege Department of Scientific Research Projects (BAP) [2008-BIL-002], This study was supported by a grant from National Boron Research Institute (BOREN, Project number: BOREN2008-C0138) and a grant from University of Ege Department of Scientific Research Projects (BAP, Project number: 2008-BIL-002). The authors would also like to thank FABAL (Pharmaceutical Sciences Research Laboratory of Faculty of Pharmacy of University of Ege, Izmir, Turkiye -https://www.fabal.ege.edu.tr) where DSC, TGA and FTIR measurements were performed.

The commercialized binder carboxymethyl cellulose sodium (CMC-Na) is considered unsuitable for micro-sized SiOx anode as it cannot endure the large volume change to retain the conductive network during repeated charge/discharge cycles. Herein, a small amount of silicon nano particles (SiNPs) is added during slurry preparation process as “nano-combs” to unfold the convoluted CMC-Na polymer chains so that they undergo a coil-to-stretch transition by interaction between polar groups (e.g -OH, -COONa) of polymer and SiNPs’ large surface. Through maximizing the utilization of binders, a uniform conductive network is constructed with increased interfacial contact with micro-sized SiOx. As a result, the SiOx electrode with optimized (10 wt%) SiNPs addition shows significantly improved initial capacity as well as cycling performance. Through revisiting CMC-Na, a currently deemed unqualified binder in SiOx anode, this work gives a brand-new perspective on the failing mechanism of Si-based anode materials as well as an improving strategy for electrode preparation.

This paper focuses on design of a control system for full bridge DC‐DC converter based on Lyapunov stability theorem which guarantees system stability. To achieve this goal, a full bridge DC‐DC converter is used as a Li‐ion battery charger and sinusoidal ripple current (SRC) is implemented as the charging algorithm. In initial step, state space equation of the system including DC‐DC converter and battery are obtained. After that, switching function is extracted by applying Lyapunov stability theorem to state space equation. Also in order to achieve unity power factor and allowable current Total Harmonic Distortion (THD) range based on standards, an Active Front End (AFE) PWM Rectifier is used. To evaluate the effectiveness of the proposed controller scheme, a laboratory prototype is implemented. Experimental result shows appropriate performance of proposed controller in tracking of reference values in comparison with fixed PI controller. In addition, results of AFE rectifier performance is evaluated by showing the unity power factor and low THD value.

PURPOSE The accurate knowledge of the effective point of measurement (Peff ) is particularly important for measurements in proximity to high dose gradients such as in the distal fall-off of particle beams. For plane-parallel ionization chambers (IC), Peff is well known and located at the center of the inner surface of the entrance window. For cylindrical ICs, Peff is shifted from the chamber's center towards the beam source. According to IAEA TRS-398, this shift can be calculated as 0.75·rcyl for light ions with rcyl being the radius of the cavity. For proton beams and in absence of a dose gradient, no shift is recommended. We have experimentally determined Peff for the 0.125 cc Semiflex IC in both proton and carbon ion beams. METHODS The first method consisted of simultaneous irradiation of a plane-parallel IC and the Semiflex in a 4 cm wide spread-out Bragg peak. In the second method, a single-energy beam was used and both ICs were positioned successively at the same measurement depths. For both approaches, the shift of the distal edge of the depth ionization distributions recorded by the two chambers at different reference points was used to calculate Peff of the Semiflex. Both methods were applied in carbon ion beams and only the latter was applied in proton beams. RESULTS Both methods yielded a similar Peff for carbon ions, 0.88·rcyl and 0.84·rcyl , which results in a difference of only 0.1 mm. The difference to the recommended value of 0.75·rcyl is 0.4 and 0.3 mm respectively, which is larger than the positioning uncertainty. In the proton beam, a Peff of 0.92·rcyl was obtained. CONCLUSIONS The Peff for the 0.125 cc Semiflex IC is shifted further from the cavity center as recommended by IAEA TRS-398 for light ions, with the shift for proton beams being even larger than for carbon ion beams. This article is protected by copyright. All rights reserved.

Three derivatives of 1-aminopyrene are functionalized with 2-picolyl and 2-picolinyl groups and tested as fluorescent sensors for metal ions. The target compounds are successfully synthesized in 50 to 90% yields and characterized by 1 H-NMR, 13 C-NMR, and HRMS. The compound with an amino picolyl group (P1) exhibits an excellent selectivity towards Cu(II) ion as the fluorescent signal shifts from 433 to 630 nm. From a fluorescence titration experiment, the limit of detection for Cu(II) ion is estimated to 0.19 µM. That the fluorescence spectral shift by Cu(II) ion is reliant on the use of acetonitrile as a co-solvent and the results from cyclic voltammetry and UV-Vis spectroscopy suggest that the sensing mechanism involves a coordination complex between the P1, acetonitrile, and Cu(II) ion. Furthermore, this P1-Cu complex can also be used as a selective fluorescent sensor for PO43- ion with a detection limit of 0.44 µM.

Erbium(III) ion (Er3+ ) has abundant energy levels that can emit light covering a quite broad wavelength range in many hosts. Here we synthesized LaSrGaO4 :Er3+ phosphors by a high-temperature solid-state method. Upon excitation at the ultraviolet (UV) band, LaSrGaO4 :Er3+ phosphors could emit green, red and near-infrared emission simultaneously. The temperature dependent emission characteristics of the as-prepared samples was then studied and two kinds of luminescent ratiometric thermometry were constructed. The first one is on the basis of two green emission bands that stems from the 2 H11/2 → 4 I15/2 and 4 S3/2 → 4 I15/2 transitions of Er3+ . The intensity ratio between these two emission bands was found to follow well with the Boltzmann distribution, and its maximum relative sensitivity was calculated to be 0.84% K-1 at 299 K. The other one depends on the 4 F9/2 → 4 I15/2 transition of Er3+ and self-luminescence of the host LaSrGaO4 , considering that these two emission lines have different temperature response. The relative sensitivity of this type of luminescence intensity ratio (LIR) thermometry could reach 1.86% K-1 at 299 K, we have successfully developed materials with one of the largest relative sensitivities to date, which provides some basis for the subsequent development of a new type of non-contact temperature sensor.

Originating from “rocking‐chair concept”, lithium‐ion batteries (LIBs) have become one of the most important electrochemical energy storage technologies, which have largely impacted our daily life. The utilization of electrolyte additives in small quantities (≤5% by wt or vol) has been long viewed as an economical and efficient approach to regulate the properties of electrolyte and electrode–electrolyte interphases and consequently improve the cycling performance of LIBs. Among all the kinds of electrolyte additives, sulfur‐containing compounds have gained significant attention due to their unique features in building stable electrode–electrolyte interphases and protect battery cells from overcharging. In this work, advances and progresses of sulfur‐containing additives used in LIBs are overviewed, with special attention paid to the working mechanisms of these electrolyte additives. Particularly, four representative sulfur‐containing compounds (i.e., 1,3‐propane sultone, prop‐1‐ene‐1,3‐sultone, 1,3,2‐dioxathiolane‐2,2‐dioxide, and ethylene sulfite) are comparatively discussed concerning their impact on electrode–electrolyte interphases and cell performances. Future work on the development of sulfur‐containing compounds as functional electrolyte additives is also provided. The present review is anticipated to be not only a base document to access the status quo in this research domain but also a guideline to select specialized additives and electrolytes for practical applications.

Medical physics 49(1), 714 - 726 (2022). doi:10.1002/mp.15343, Published by AAPM, College Park, Md.

In this paper, based on the fluorescence of carbon quantum dots (CQDs) quenched by mercury ions (Hg2+ ) and the nonresponse of Hg2+ to rhodamine B fluorescence, a dual emission ratio fluorescence sensor was constructed to realize the quantitative detection of Hg2+ . Under excitation at 365 nm, the fluorescence spectrum showed double emission peaks at 437 nm and 590 nm, corresponding to the fluorescence emissions of CQDs and rhodamine B, respectively. This method quantitatively detected Hg2+ based on the linear relationship between the ratio of the intensities of the two emission peaks F437 /F590 and the concentration of Hg2+ . The detection range was 10-70 nM, and the limit of detection (S/N = 3) was 3.3 nM. In addition, this method could also realize the qualitative and semiquantitative detection of Hg2+ according to the fluorescence colour change of the probe under ultraviolet light. After various evaluations, the method could be successfully applied to the quantitative and visual detection of Hg2+ in tap water, and demonstrated excellent selectivity, anti-interference performance, and repeatability of the method.

Deep-ultraviolet (deep-UV) nonlinear optical (NLO) crystals are key materials in creating tunable deep-UV lasers for frequency conversion technology. However, practical application of the sole usable crystal, KBe2 BO3 F2 , has been hindered by the high toxicity of beryllium and its layering tendency in crystal growth. Herein, we report a beryllium-free deep-UV NLO material NaSr3 (OH)(B9 O16 )[B(OH)4 ] (NSBOH), synthesized by a covalent bond modification strategy under hydrothermal conditions. Moisture-stable NSBOH exhibits strong second-harmonic generation (SHG) at 1064 nm (3.3 × KH2 PO4 ) and 532 nm (0.55 × β-BaB2 O4 ), both amongst the largest powder SHG responses for a deep-UV borate, with good phase-matchability and a short wavelength cutoff edge (below 190 nm). NSBOH possesses a 3D covalent anionic [B9 O19 ]∞ honeycomb-like framework with no layering. The Sr2+ and Na+ ions, residing in the cavities of the anionic framework, act as templates for the assembly and favorable alignment of NLO-active groups, resulting in an optimal balance between strong SHG activities and wide UV transparency. These merits indicate NSBOH is a very attractive candidate for deep-UV NLO applications.

A stable rod-like sulfonated viologen (R-Vi) derivative is developed through a spatial-structure-adjustment strategy for neutral aqueous organic redox flow batteries (AORFBs). The obtained R-Vi features four individual methyl groups on the 2,2',6,6'-positions of the 4,4'-bipyridine core ring. The tethered methyls confine the movement of the alkyl chain as well as the sulfonic anion, thus driving the spatial structure from sigmoid to rod shape. The R-Vi with weak charge attraction and large molecular dimension displays an ultralow membrane permeability that is only 14.7 % of that of typical sigmoid viologen. Moreover, the electron-donating effect of methyls endows R-Vi with the lowest redox potential of -0.55 V vs. SHE among one-electron-storage viologen-based AORFBs. The AORFB with the R-Vi anolyte and a K4 Fe(CN)6 catholyte exhibits an energy efficiency up to 87 % and extremely low capacity-fade rate of 0.007 % per cycle in 3200 continuous cycles.

Knowledge of the structure of the electrical double layer in ionic liquids (IL) is crucial for their applications in electrochemical technologies. We report the synthesis and applicability of an imidazolium-based amphiphilic ionic liquid with a perdeuterated alkyl chain for studies of electric potential-dependent rearrangements, and changes in the microenvironment in a monolayer on a Au(111) surface. Electrochemical measurements show two states of the organization of ions on the electrode surface. In situ IR spectroscopy shows that the alkyl chains in imidazolium cations change their orientation depending on the adsorption state. The methylene-d2 stretching modes in the perdeuterated IL display a reversible, potential-dependent appearance of a new band. The presence of this mode also depends on the anion in the IL. Supported by quantum chemical calculations, this new mode is assigned to a second νas (CD2 ) band in alkyl-chain fragments embedded in a polar environment of the anions/solvent present in the vicinity of the imidazolium cation and electrode. It is a measure of the potential-dependent segregation between polar and nonpolar environments in the layers of an IL closest to the electrode.

This study is the first to report the clinical lifetime of Varian Kapton sealed ion chambers as a retrospective review. The data have been analyzed using ion chamber gain values, daily quality assurance results, monthly quality assurance results, and delivered treatment field data were analyzed to comprehensively review trends. The data show the average lifetimes of the ion chambers from our institution, so other physicists can prepare for replacement. Additionally, we share our experience in performing quality assurance tests to calibrate and validate the radiation beam after ion chamber replacement.

Rational nanostructure design has proved fruitful in addressing the bottlenecks of diverse fields. Especially hollow multi-shelled structures (HoMS) have stood out due to their temporal-spatial ordering mass transfer and buffering effect. Localizing multiple cores in a HoMS is highly desired, which could endow it with more fascinating properties. However, such a structure has been barely reported due to the highly challenging fabrication. Here, we develop a controllable synthesis strategy to realize such a structure, which is applicable for diverse cores and shells. Additionally, cores and shells could be tuned to be homogeneous or heterogeneous, with the core and shell number well controlled. In situ TEM analysis verifies that the inner shell confines the expansion orientation of cores, while the outer shell maintains a stable interface. In addition to energy storage, such structure is also promising for multi-drug co-delivery and sequential responsive release as well as tandem catalysis applications.

Chalcogenide-containing compounds have been widely studied as infrared nonlinear optical (NLO) materials. However, they have never been applied in the ultraviolet (UV) region owing to the high energy levels of chalcogen anions, leading to band gap narrowing. We report the synthesis of a new UV NLO oxysulfide La3 Ga3 Ge2 S3 O10 with an exceptionally wide band gap of 4.70 eV due to from the unique anion-ordered frameworks comprising 1D 1∞ [(Ga3/5 Ge2/5 )3 S3 O3 ] triangular tubes and 0D (Ga3/5 Ge2/5 )2 O7 dimers of corner-sharing (Ga/Ge)S2 O2 and (Ga/Ge)O4 tetrahedra, respectively. Second harmonic generation (SHG) measurements revealed that La3 Ga3 Ge2 S3 O10 was phase matchable with twice the SHG response of KH2 PO4 . The results of theoretical calculations suggest that the strong SHG response is mainly attributable to the S-3p and O-2p orbitals in the occupied states. The anion-directed band-gap engineering may give insights into the application of NLO oxychalcogenides in the UV regions.

The development of high-performance cathode materials for aqueous zinc-ion batteries (ZIBs) based on nontoxic and earth-abundant elements remains a great challenge. This study introduces the iron-based NASICON-type material Na4 Fe3 (PO4 )2 (P2 O7) with carbon layer (NFPP@C) as a cathode material for ZIBs. When Zn2+ /Na+ dual ion electrolyte is employed, NFPP@C shows a high capacity of 114.4 mAh g-1 with two voltage plateaus, excellent rate capability (95 mAh g-1 at 2 A g-1 ), and long-term cycling stability (66.4 mAh g-1 after 1800 cycles at 1 A g-1 ). The outstanding electrochemical performance is ascribed to the synergistic use of NFPP@C and dual ion electrolyte. The NASICON-structure and carbon layer of NFPP@C enable fast ion and electron transport, whereas Na+ in the electrolyte reduces the concentration gradient between the electrode and electrolyte, and thus inhibits excessive extraction of Na+ from NFPP, maintaining structural stability. Moreover, Zn2+ /Na+ co-intercalation in NFPP@C brings two potential platforms and enhanced capacity.

Mn-based oxides have sparked extensive scientific interest for aqueous Zn-ion batteries due to the rich abundance, plentiful oxidation states, and high output voltage. However, the further development of Mn-based oxides is severely hindered by the rapid capacity decay during cycling. Herein, a two-step metal-organic framework (MOF)-engaged templating strategy has been developed to rationally synthesize heterostructured Mn 2 O 3 -ZnMn 2 O 4 hollow octahedrons (MO-ZMO HOs) for stable zinc ion storage. The distinctive composition and hollow heterostructure endow MO-ZMO HOs with abundant active sites, enhanced electric conductivity, and superior structural stability. By virtue of these advantages, the MO-ZMO HOs electrode shows high reversible capacity, impressive rate performance, and outstanding electrochemical stability. Furthermore, ex situ characterizations reveal that the charge storage of MO-ZMO HOs mainly originates from the highly reversible Zn 2+ insertion/extraction reactions.

Discovering new functional genes and developing high-performance materials are the goals being pursued by scientists. In this work, we successfully obtained a second-order nonlinear optical (NLO) material via the aqueous solution method, Y[N(CN) 2 ] 4 [NH(C 2 H 5 ) 3 ]∙3H 2 O, which is the first NLO material with anionic group N(CN) 2 - . Remarkably, this material not only is strongly NLO-active at 1064 nm with a response of about 2.8 × KH 2 PO 4 , but also possesses a short UV absorption edge of 250 nm. In-depth first-principles calculations well illustrate that the optical properties are mainly from the strong interaction of N, C and Y atoms. This result indicates that the N(CN) 2 - anion may be a new NLO functional gene. This work enriches the diversity of NLO functional genes and materials.

In this work, we synthesized diethylamino substituted pyrazolo imine (3) fluorescent probe for recognition of Hg2+ ion.The sensor probe 3 can detect Hg2+ by colorimetric method, and there is a 10-fold enhancement in fluorescence response. When the fluorescent probe bound with Hg2+ ion, turn-on fluorescence was observed via the coordination. Probe 3 has an excellent selectivity toward Hg2+ in the CH3 CN/H2 O (8:2, v/v) solution with low limit of detection and high binding association constant of 551 parts per billion (ppb) and 6.6067 × 106 m-1 for 3+Hg2+ , respectively. Furthermore, the formation of 3+Hg2+ complex with 1:1 binding mode was evidenced by Job's plot, 1 H NMR spectroscopy and Mass analysis. In addition, probe 3 is a feasible option to detect Hg2+ in various sources of water samples. Bio-imaging experiments have demonstrated that probe 3 can be used to monitor Hg2+ in Escherichia coli bacterial cell. The sensor 3 was also used for paper strip application to detect Hg2+ ion.

Solid polymer electrolytes (SPEs) have become increasingly attractive in solid‐state lithium‐ion batteries (SSLIBs) in recent years because of their inherent properties of flexibility, processability, and interfacial compatibility. However, the commercialization of SPEs remains challenging for flexible and high‐energy‐density LIBs. The incorporation of functional additives into SPEs could significantly improve the electrochemical and mechanical properties of SPEs and has created some historical milestones in boosting the development of SPEs. In this study, we review the roles of additives in SPEs, highlighting the working mechanisms and functionalities of the additives. The additives could afford significant advantages in boosting ionic conductivity, increasing ion transference number, improving high‐voltage stability, enhancing mechanical strength, inhibiting lithium dendrite, and reducing flammability. Moreover, the application of functional additives in high‐voltage cathodes, lithium–sulfur batteries, and flexible lithium‐ion batteries is summarized. Finally, future research perspectives are proposed to overcome the unresolved technical hurdles and critical issues in additives of SPEs, such as facile fabrication process, interfacial compatibility, investigation of the working mechanism, and special functionalities.

The effect of a series of tetramethylammonium salts with different counter anions on the photophysical properties of a chiral Eu(III) complex (Eu( D -facam) 3 ) was investigated. The aniondependent luminescence of the Eu(III) complex was observed, and particularly in the presence of acetate ions, an outstanding luminescence enhancement (>300 times) and induced circularly polarized luminescence ( g lum = -0.63) were obtained. The energy transfer process was then evaluated using key photophysical parameters, and it was found that the sensitisation efficiency of the Eu(III) complex significantly increased in the presence of tetramethylammonium acetate (TMAOAc). The interactions between Eu( D -facam) 3 and TMAOAc were confirmed by luminescence analysis, circular dichroism spectroscopy, Fourier transform infrared spectroscopy and mass spectral measurements.

The stepwise chemical reduction of a molecular warped nanographene (WNG) having a negatively curved π-surface and defined C80 H30 composition with Cs metal used as the reducing and complexing agent allowed the isolation of three different reduced states with one, two, and three electrons added to its π-conjugated system. This provided a unique series of nanosized carbanions with increasing negative charge for in-depth structural analysis of consequences of controlled electron charging of non-planar nanographenes, using X-ray crystallographic and computational tools. The 3D molecular electrostatic potential (MEP) maps identified the negative charge localization at the central part of the WNG surface where selective coordination of Cs+ ions is confirmed crystallographically. In-depth theoretical investigation revealed a complex response of the WNG to the stepwise electron acquisition. The extended and contorted π-surface of the WNG undergoes subtle swinging distortions that are accompanied by notable changes in the electronic structure and site-dependent aromaticity of the resulting carbanions.

Chiral tetrahydro-β-carboline (THβC) is not only a prevailing structural feature of many natural alkaloids but also a versatile synthetic precursor for a vast array of monoterpenoid indole alkaloids. Asymmetric synthesis of C1-alkynyl THβCs remains rarely explored and challenging. Herein, we describe the development of two complementary approaches for the catalytic asymmetric alkynylation of 3,4-dihydro-β-carbolinium ions with up to 96 % yield and 99 % ee. The utility of chiral C1-alkynyl THβCs was demonstrated by the collective total syntheses of seven indole alkaloids: harmicine, eburnamonine, desethyleburnamonine, larutensine, geissoschizol, geissochizine, and akuammicine.

Low-temperature NMR studies with a 4-C-methyl-4-O-benzoyl galactopyranosyl donor enable the observation and characterization of a bridged bicyclic dioxacarbenium ion arising from participation by a distal ester. Variable-temperature NMR studies reveal this bridged ion to decompose at temperatures above ≈-30 °C. In the absence of the methyl group, the formation of a bicyclic ion is not observed. It is concluded that participation by typical secondary distal esters in glycosylation reactions is disfavored in the ground state conformation of the ester from which it is stereoelectronically impossible. Methylation converts the secondary ester to a conformationally more labile tertiary ester, removes this barrier, and renders participation more favorable. Nevertheless, the minor changes in selectivity in model glycosylation reactions on going from the secondary to the tertiary esters at both low and room temperature argue against distal group participation being a major stereodirecting factor even for the tertiary system.

ChemElectroChem 8(24), 4750-4761 (2021). doi:10.1002/celc.202101174, Published by Wiley-VCH, Weinheim

Polymeric carbon nitride (PCN) as a class of two-electron oxygen reduction reaction (2 e- ORR) photocatalyst has attracted much attention for H2 O2 production. However, the low activity and inferior selectivity of 2 e- ORR greatly restrict the H2 O2 production efficiency. Herein, we develop a new strategy to synthesize hydrophilic, fragmented PCN photocatalyst by the terminating polymerization (TP-PCN) effect of iodide ions. The obtained TP-PCN with abundant edge active sites (AEASs), which can form quasi-homogeneous photocatalytic system, exhibits superior H2 O2 generation rate (3265.4 μM h-1 ), far surpassing PCN and other PCN-based photocatalysts. DFT calculations further indicate that TP-PCN is more favorable for electron transiting from β spin-orbital to the π* orbitals of O2 , which optimizes O2 activation and reduces the energy barrier of H2 O2 formation. This work provides a new concept for designing functional photocatalysts and understanding the mechanism of O2 activation in ORR for H2 O2 production.