bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sodium Tetrakis(hexafluoroisopropyloxy)aluminates: Synthesis and Electrochemical Characterisation of a Room‐Temperature Solvated Ionic Liquid
Authors: Ould Darren M. C. , Menkin Svetlana , Smith Holly E. , Riesgo‐González Víctor , Smith Thomas H. , Chinn Melissa N. B. , Jónsson Erlendur , Bond Andrew D. , Grey Clare P. , Wright Dominic S. 
Published: September 2023

AbstractWeakly coordinating anions (WCAs) are used throughout chemistry to minimise cation‐anion interactions in the solid and solution states. The ability to suppress ion‐pairing has important bearings ‐ or impacts on the properties of materials, on single‐site catalysis and on ionic conductivity. Fluorinated alkoxy aluminates (containing [Al(ORF)4]− anions) are an attractive class of WCA owing to their high thermodynamic stability, stemming from strong aluminium‐oxygen bonds, and the ability to tailor their steric and electronic properties by changing the organic substituents (R). This work explores the structural and electrochemical properties of sodium tetrakis(hexafluoroisopropyloxy)aluminate, Na[Al(hfip)4] ⋅ xDME (hfip=hexafluoroisopropyloxy, OiPrF, DME=1,2‐dimethoxyethane, x=3 or 1). When solvated with one DME molecule, Na[Al(hfip)4] ⋅ DME is a room‐temperature solvated ionic liquid, with an activation energy of conduction of 0.4 eV. Both Na[Al(hfip)4] ⋅ 3DME and Na[Al(hfip)4] ⋅ DME have been studied as electrolyte salts for sodium‐ion batteries, where sodium‐ion cycling proceeds but with low capacity retention.
Electrocatalytic Hydrogen Evolution using a Nickel‐based Calixpyrrole Complex: Controlling the Secondary Coordination Sphere on an Electrode Surface
Authors: Trowbridge Logan , Averkiev Boris , Sues Peter E. 
Published: September 2023

AbstractIncorporating design elements from homogeneous catalysts to construct well defined active sites on electrode surfaces is a promising approach for developing next generation electrocatalysts for energy conversion reactions. Furthermore, if functionalities that control the electrode microenvironment could be integrated into these active sites it would be particularly appealing. In this context, a square planar nickel calixpyrrole complex, Ni(DPMDA) (DPMDA=2,2′‐((diphenylmethylene)bis(1H‐pyrrole‐5,2‐diyl))bis(methaneylylidene))bis(azaneylylidene))dianiline) with pendant amine groups is reported that forms a heterogeneous hydrogen evolution catalyst using anilinium tetrafluoroborate as the proton source. The supported Ni(DPMDA) catalyst was surprisingly stable and displayed fast reaction kinetics with turnover frequencies (TOF) up to 25,900 s−1 or 366,000 s−1 cm−2. Kinetic isotope effect (KIE) studies revealed a KIE of 5.7, and this data, combined with Tafel slope analysis, suggested that a proton‐coupled electron transfer (PCET) process involving the pendant amine groups was rate‐limiting. While evidence of an outer‐sphere reduction of the Ni(DPMDA) catalyst was observed, it is hypothesized that the control over the secondary coordination sphere provided by the pendant amines facilitated such high TOFs and enabled the PCET mechanism. The results reported herein provide insight into heterogeneous catalyst design and approaches for controlling the secondary coordination sphere on electrode surfaces.
The Calculation of Both Electrostatic and Van der Waals Effects to Probe the Efficiency of Solvent Extraction of Heterocyclic Aromatics from Heavy Oil
Authors: Wei Xingguo , Cui Lingrui , Liu Cao , Shen Kaili , Xu Jun , Dilworth Jon , Xiao Tiancun , Cao Fahai 
Published: September 2023

AbstractDue to the complex composition and similar structure, the extraction denitrification of aromatic rich oil is faced with the contradiction problem of denitrification efficiency and aromatic loss which cannot be efficiently solved by experiments. However, the complex interactions involved can be analyzed from the perspective of calculation, and the prediction criteria and methods are proposed. Based on rigorous density functional theory calculation data, Simple models based on electrostatic potential (ESP) and Van der Waals potential (VdWP)‐based calculations were established and validated. The twofold model provided the best prediction for interactions between extractants and nitrogen compounds and between extractants and aromatics, which determines denitrification efficiency and aromatic loss, respectively, due to the most complete description of both electrostatic and VdW force. This provides a powerful tool for evaluating the non‐covalent interactions and thence tuning the efficiency of the separation process. Thus, high denitrification efficiency (43.2~66.3 %) and moderate aromatic loss (1.7~4.4 %) were obtained using screened deep eutectic solvents (DESs). This ideal observation provided the potential for mild hydrodesulfurization and manufacture of high‐grade carbon materials.
Metal‐Free Catalytic Hydrogenolysis of Chlorosilanes into Hydrosilanes with “Inverse” Frustrated Lewis Pairs**
Authors: Durin Gabriel , Berthet Jean‐Claude , Thuéry Pierre , Nicolas Emmanuel , Cantat Thibault 
Published: September 2023

AbstractThe challenging metal‐free catalytic hydrogenolysis of silyl chlorides to hydrosilanes is unlocked by using an inverse frustrated Lewis pair (FLP), combining a mild Lewis acid (Cy2BCl) and a strong phosphazene base (BTPP) in mild conditions (10 bar of H2, r. t.). In the presence of a stoichiometric amount of the base, the hydrosilanes R3SiH (R=Me, Et, Ph) are generated in moderate to high yields (up to 95 %) from their chlorinated counterparts. A selective formation of the valuable difunctional monohydride Me2SiHCl is also obtained from Me2SiCl2. A mechanism is proposed based on stoichiometric experiments and DFT calculations; it highlights the critical role of borohydride species generated by the heterolytic splitting of H2.
The Facile Hydrolysis of Imidazolinium Chlorides (N‐Heterocyclic Carbene Precursors) Under Basic Aqueous Conditions
Authors: Touj Nedra , Taping Jerwin Jay , Tumanov Nikolay , Wouters Johan , Delaude Lionel 
Published: September 2023

AbstractThe hydrolysis of imidazolinium chlorides takes place readily in a basic water/dichloromethane biphasic mixture at room temperature. Experimental parameters were optimized to afford full conversions and high yields of γ‐aminoformamides starting from twelve symmetrical substrates with alkyl or aryl substituents on their nitrogen atoms, and five unsymmetrical 1‐alkyl‐3‐arylimidazolinium chlorides. NMR and XRD analyses showed that the cleavage of unsymmetrical salts led to γ‐alkylamino‐N‐arylformamides with a high regioselectivity and that bulky alkyl or aryl groups on the formamide moiety led to the isolation of the (E)‐isomer in high stereoisomeric purity (>95 %), whereas smaller and more flexible alkyl substituents afforded mixtures of (E)‐ and (Z)‐rotamers. Control experiments showed that the hydrolysis of 1,3‐dimesitylimidazolinium chloride (SIMes ⋅ HCl) did not occur readily in pure or acidic water and that the presence of bulky aromatic substituents on the nitrogen atoms of 1,3‐bis(2,6‐diisopropylphenyl)imidazolinium chloride (SIDip ⋅ HCl) efficiently slowed down its hydrolysis under basic aqueous conditions. Most strikingly, this work highlighted the critical influence of the counteranion on the reactivity of imidazolinium cations. Indeed, the chloride salts underwent a facile hydrolysis in the presence of water and Na2CO3, whereas various other NHC ⋅ HX derivatives reacted much slower or remained essentially inert under these conditions.
Atroposelective NiII‐Catalyzed Cross‐Coupling Reactions Enable a Deeper Understanding of Negishi Couplings: Isolation and Application of Solid Aryl Higher‐Order Zincates
Authors: Groß Damian , van Otterlo Willem A. L. , Trapp Oliver , Berthold Dino 
Published: September 2023

AbstractThe Negishi cross‐coupling reactions involves the application of organozinc reagents and is a highly versatile reaction in synthetic organic chemistry. The transmetallation step plays a pivotal role in the mechanism of these types of cross‐coupling reactions. In this study, mechanistic investigations are presented indicating that higher‐order zincates are the transmetallating active species in Pd‐ and Ni‐catalyzed Negishi cross‐coupling reactions. These findings are supported by halide salt addition experiments and by obtaining a single X‐ray crystal structure of the solid monoaryl higher‐order zincate [1‐NaphthylZnX3]2−Mg(THF)22+. The procedure developed in this work was further applied to the synthesis of various monoaryl higher‐order zincates, after which their synthetic usefulness in terms of high reactivity towards transmetallation in Negishi cross‐couplings, as well as stability, was exemplified in several reactions.
Digital image analysis allows objective stratification of patients with silent PIT1‐lineage pituitary neuroendocrine tumors
Authors: Zhao Jiangyan , Ji Chenxing , Cheng Haixia , Ye Zhen , Yao Boyuan , Shen Ming , Shou Xuefei , Zhou Xiang , Ye Hongying , Zhang Zhaoyun , Chen Hong , Wang Yongfei , He Fuchu , Zhao Yao , Gong Wei , Zhang Qilin , Qiao Nidan 
Published: September 2023

AbstractStudies describing the clinical presentation and prognosis of patients with silent PIT1 (pituitary specific transcription factor)‐lineage pituitary neuroendocrine tumors (PitNETs) are rare. We identified patients with positive PIT1 tumor staining but without evidence of hormone hypersecretion at a tertiary center. Clusters were obtained according to cell morphology and immunostaining from each patient's digitally segmented whole slide image. We compared the clinical presentations, radiological features, and prognoses of the different clusters. We identified 146 patients (68 male, 42.9 ± 14.1 years old) with silent PIT1‐lineage PitNETs. Morphology clustering suggested that tumors with large nuclei and apparent eccentricity were associated with a higher proportion of aggressiveness and a higher hazard of recurrence [hazard ratio (HR): 2.64, (95% CI, 1.06–6.55), p = 0.037]. Immunohistochemical clustering suggested that tumors with thyroid stimulating hormone (TSH) staining or all negative PIT1‐lineage hormones were associated with a higher proportion of aggressiveness and a higher risk of recurrence [HR: 12.4, (95% CI, 1.60–93.5), p = 0.015]. We obtained three‐tier risk profiles by combining morphological and immunohistochemical clustering. Patients with the high‐risk profile presented the highest recurrence rate compared with those in the medium‐risk and low‐risk profiles [HR: 3.54, (95% CI, 1.40–8.93), p = 0.002]. In conclusion, digital image analysis based on cell morphology and immunohistochemical staining allows objective stratification of patients with silent PIT1‐lineage tumors. Typical morphological characteristics of high‐risk tumors are large tumor nuclei and high eccentricity, and typical immunostaining characteristics are TSH staining or negative staining for all PIT1‐lineage hormones.
Development and Verification of a Diagnostic Technology for Waste Battery Deterioration Factors
Authors: Jung Sunghun , Seo Joon Kyo , Jang Il‐Chan , Kim Jihun , Shim Jae‐Hyun , Woo Jung‐Je 
Published: September 2023

AbstractWe defined four major deterioration factors (electrolyte loss (EL), lithium loss (LL), lithium precipitation (LP), and compound deterioration (CD)). Then, we derived eleven key performance indicators (KPIs) for comparative analysis. After that, we fabricated three deteriorated cells for each of three deterioration factors (EL, LL, and LP) and one cell with CD (for verification) with four individual (dis)charging experiment manuals. The two major contributions of this study are the performance of 1) trend analysis to determine a suitable diagnostic metric by inspecting the eleven KPIs and 2) comparison analysis of
and
to verify the effectiveness of utilizing
as a real‐time deterioration diagnostic factor using a concept of model‐in‐the‐loop simulation. The results show that 1)
has the most conspicuous trendline tendency among the eleven comparison targets for all four major deterioration factors, and 2) the angle difference between the two trends of
and
lies within a minimum of 9° and a maximum of 43° (with a
sscale on the x‐axis and a
scale on the y‐axis for a clear trend line analysis). From this, we can conclude that the trendline‐based real‐time deterioration analysis employing
may be practically applicable to a limited extent.
Electronic and Optical Properties of Novel Graphene‐Like InTe Monolayer: First Principle Calculations
Authors: Liao Yujie , Liu Huating , Yuan Guanghui , Huang Zongyu , Qi Xiang 
Published: September 2023

AbstractInspired by the research on exotic two‐dimensional (2D) carbon nanomaterials, that is, graphene, monolayer group‐IIIA chalcogenide compounds have broad application prospects in the field of material science and device physics. The structure characteristics and electronic and optical properties of the graphene‐like InTe monolayer are calculated and discussed in this work. It is found that the two sides of InTe monolayer are the same elements with the same electronegativity, and its charge distribution is very uniform. The band structure indicates that the InTe monolayer exhibits an indirect‐band gap of 1.286 eV. It is also noted that the absorption of InTe monolayer extends from the ultraviolet region to the visible region, reflecting its ability to capture light in a wide spectrum. Additionally, the absorption coefficient of InTe monolayer in the ultraviolet is up to 10−5 cm–1, which indicates that InTe has certain advantages in the application of ultraviolet detectors and photovoltaic absorption devices. Therefore, the present work provides a theoretical foundation for the design of electronic and optoelectronic device based on InTe, and further provides a favorable guidance for the practical application of these materials.
The Transformation Relationship between Two Hydrates of Calcium Dobesilate and its Application in Crystallization Process
Authors: Yao Xuan , Wu Yan‐Fang , Sun Shu‐Jia , Ren Fu‐Zheng , Yang Shun‐Ping , Liu Yan 
Published: September 2023

AbstractAs a classic drug with several hydrate forms, Calcium Dobesilate is widely used in the treatment of diabetic retinopathy and chronic venous insufficiency, and Monohydrate is the medicinal form. The key impurity, hydroquinone, is an important synthetic raw material of Calcium Dobesilate, but has a potential genotoxicity, so the content of hydroquinone in the final product should be lower. In this paper, based on characterization results of different hydrates, the Dihydrate is found as the beneficial form for purification, thus a novel crystallization process for purification has been carried out. The Dihydrate is obtained by a recrystallization and then transformed into the Monohydrate. From the results of solid‐state characterization and process analysis of phase transformation, the transformation relationship between the two hydrates is determined, and it is found out that the transformation from Dihydrate to Monohydrate could only happen via solution‐mediated transformation in Ethanol or Isopropanol. The impurity content of the Monohydrate product prepared by the new crystallization process is far below the current standard in the Pharmacopoeia.
Surface Passivation of LiCoO2 by Solid Electrolyte Nanoshell for High Interfacial Stability and Conductivity
Authors: Peng Jun , Peng Hao , Shi Chen‐Guang , Huang Ling , Sun Shi‐Gang 
Published: September 2023

AbstractThe practical application of lithium cobalt oxide (LiCoO2) cathodes at high voltages is hindered by the instability of the surface structure and side reactions with the electrolyte. Herein, we prepared a multifunctional hierarchical core@double‐shell structured LiCoO2 (MS‐LCO) cathode material using a scalable sol–gel method. The MS‐LCO cathode material comprised an outer shell with fast lithium‐ion conductivity, a La/Zr co‐doped inner shell, and a bulk LiCoO2 core. The outermost shell prevented direct contact between the electrolyte and LiCoO2 core, which alleviated the electrolyte decomposition and loss of active cobalt, while the La/Zr co‐doped shell improved the structural stability at higher voltages in a half‐cell with a liquid electrolyte. The MS‐LCO cathode exhibited a stable capacity of 163.1 mAh g−1 after 500 cycles at 0.5 C, and a high specific capacity of 166.8 mAh g−1 at 2 C. In addition, a solid lithium battery with the surface‐passivated MS‐LCO cathode and a polyethylene oxide (PEO)‐based inorganic/organic composite electrolyte retained 85.8 % of its initial discharge capacity after 150 cycles at a charging cutoff voltage of 4.3 V. Thus, the introduction of a surface‐passivating shell can effectively suppress the decomposition of PEO caused by highly reactive oxygen species in LiCoO2 at high voltages.
X‐Rays emission by high‐intensity pulsed lasers irradiating thin foils at PALS laboratory
Authors: Torrisi Lorenzo , Cutroneo Mariapompea , Torrisi Alfio 
Published: September 2023

AbstractX‐rays and forward ion emission from laser‐generated plasma in the Target Normal Sheath Acceleration regime of different targets with 10‐μm thickness, irradiated at Prague Asterix Laser System (PALS) laboratory at about 1016 W/cm2 intensity, employing a 1,315 nm‐wavelength laser with a 300‐ps pulse duration, are investigated. The photon and ion emissions were mainly measured using Silicon Carbide (SiC) detectors in time‐of‐flight configuration and X‐ray streak camera imaging. The results show that the maximum proton acceleration value and the X‐ray emission yield growth are proportional to the atomic number of the irradiated targets. The X‐ray emission is not isotropic, with energies increasing from 1 keV for light atomic targets to about 2.5 keV for heavy atomic targets. The laser focal position significantly influences the X‐ray emission from light and heavy irradiated targets, indicating the possible induction of self‐focusing effects when the laser beam is focalized in front of the light target surface and of electron density enhancement for focalization inside the target.
C‐MRC–based cooperative spatial modulation with antenna selection
Authors: Aydin Erdogan , Basar Ertugrul , Ilhan Haci , Kabaoğlu Nihat 
Published: September 2023

SummaryA new high‐performance low‐complexity cooperative maximal ratio combining (C‐MRC)‐based cooperative relaying scheme, which is called antenna selection‐aided cooperative spatial modulation scheme with C‐MRC (AS‐CSM), is proposed for decode and forward (DF)‐based cooperative relaying networks operating over independent but non‐identically distributed (i.n.d.) Rayleigh fading channels. The AS‐CSM scheme is formed with the combination of cooperative SM with the high‐performance low‐complexity coherent demodulator C‐MRC and antenna selection techniques. In the AS‐CSM scheme, the information is transmitted from the source terminal (ST) to the relay terminal (RT) and the destination terminal (DT) in the form of not only modulated symbols but also antenna indices, which carry additional information bits in the spatial domain. Therefore, a high spectral efficiency is obtained by the proposed scheme for cooperative relaying networks. In this scheme, first, the index of the activated antenna of ST is estimated, and the best antenna selection at RT is investigated considering the received instantaneous equivalent to signal‐to‐noise values acquired at DT. The transmitted symbols are estimated with low‐complexity coherent demodulator C‐MRC at DT by using the noisy signals from ST and RT. An exact closed‐form expression for the bit error probability (BEP) of the AS‐CSM scheme is derived, and the theoretical results are validated with Monte‐Carlo simulation results.
A survey and meta‐analysis of application‐layer distributed denial‐of‐service attack
Authors: Odusami Modupe , Misra Sanjay , Abayomi‐Alli Olusola , Abayomi‐Alli Adebayo , Fernandez‐Sanz Luis 
Published: September 2023

SummaryBackgroundOne of the significant attacks targeting the application layer is the distributed denial‐of‐service (DDoS) attack. It degrades the performance of the server by usurping its resources completely, thereby denying access to legitimate users and causing losses to businesses and organizations.AimThis study aims to investigate existing methodologies for application‐layer DDoS (APDDoS) attack defense by using specific measures: detection methods/techniques, attack strategy, and feature exploration of existing APDDoS mechanisms.MethodologyThe review is carried out on a database search of relevant literature in IEEE Xplore, ACM, Science Direct, Springer, Wiley, and Google Search. The search dates to capture journals and conferences are from 2000 to 2019. Review papers that are not in English and not addressing the APDDoS attack are excluded. Three thousand seven hundred eighty‐nine studies are identified and streamlined to a total of 75 studies. A quantifiable assessment is performed on the selected articles using six search procedures, namely: source, methods/technique, attack strategy, datasets/corpus, status, detection metric, and feature exploration.ResultsBased on existing methods/techniques for detection, the results show that machine learning gave the highest proportion with 36%. However, assessment based on attack strategy shows that several studies do not consider an attack form for deploying their solution. Result based on existing features for the APDDoS detection technique shows request stream during a user session and packet pattern gave the highest result with 47%. Unlike packet header information with 33%, request stream during absolute time interval with 12% and web user features 8%.ConclusionResearch findings show that a large proportion of the solutions for APDDoS attack detection utilized features based on request stream during user session and packet pattern. The optimization of features will improve detection accuracy. Our study concludes that researchers need to exploit all attack strategies using deep learning algorithms, thus enhancing effective detection of APDDoS attack launch from different botnets.
Physical layer security for multiuser multi‐eavesdropper multi‐input multi‐output (MIMO) system in the presence of imperfect feedback
Authors: Kumar Rajiv , Chauhan Sudakar Singh 
Published: September 2023

SummaryIn this work, we analyze the physical layer security (PLS) for a multiuser (MUS) multi‐input multi‐output multi‐eavesdropper (MIMOME) wireless network using selection transmission (ST) at the base station (BS) with maximum ratio combining (MRC) at both of the receivers, receivers of legitimate users (LUs) as well as the receivers of illegitimate users over an uncorrelated Rayleigh fading channel. In this scenario, multiple users communicate to a BS at the same time multiple eavesdropper user may intercept the transmission. Next, we drive exact closed‐form expression for probability of nonzero secrecy capacity (PNZSC) and secrecy outage probability (SOP) in the presence of imperfect channel state information (ICSI). At last, we present the simulation results to authenticate the analytical results and analyze the impact of ICSI on PLS of MUS‐MIMOME system.