Opposite Transfer Research Articles

Opposite Electron Transfer Induced High Valence Mo Sites for Boosting the Water Splitting Performance of Ir Atoms.

Developing highly efficient and low-cost bifunctional electrocatalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in water splitting poses significant challenges. In this study, a novel bifunctional electrocatalyst, Irn-CoMoPOx, was achieved via incorporating low-loading Ir single atoms and clusters with the high-valence Mo6+ modified CoPOx nanosheets. The Irn-CoMoPOx catalyst demonstrates remarkable low overpotentials of 222 mV and 36 mV for the OER and HER, respectively, in delivering a current density of 10 mA cm-2. When employed as both the anode and cathode catalyst in overall water splitting, the Irn-CoMoPOx∥Irn-CoMoPOx configuration exhibits a superior cell voltage of 1.53 V, outperforming the benchmark Pt/C∥IrO2 electrolytic cell (1.60 V) for achieving the current density of 10 mA cm-2. Benefiting from the high-valence of Mo species, the metal-support interaction of Irn-CoMoPOx was greatly strengthened, resulting in an order of magnitude increase in the mass activity of Ir for the HER. The high valence of non-noble metals plays a crucial role in tuning the local electronic configurations and optimizing the adsorption energies of the intermediates, which synergistically improves the overall performance of Ir in water splitting. The study provides valuable insights for future research in the utilization of Ir-based bifunctional catalysts for overall water electrocatalysis applications.

An integrated experimental and theoretical study on Si/Al-based and Ca-based additives for immobilizing heavy metals during pyrolysis of high-organic solid waste

The high-organic solid waste (HSW), collected in compliance with China’s mandatory waste classification policy, exhibits elevated levels of heavy metals and a low ash composition. Effective management of HSW has become a contemporary focal point, with pyrolysis emerging as a viable method to mitigate secondary pollution and achieve waste-to-resource conversion. To address metallic contamination, the utilization of Si/Al-based and Ca-based additives was investigated to immobilize and stabilize heavy metals in situ during HSW pyrolysis. Experimental results demonstrated that Si/Al-based minerals, notably kaolin, effectively immobilized Cr, Cu, Pb, and Zn, while CaO enriched As and Cd better. The employment of additives enhanced heavy metal stabilization, thereby reducing ecological risks of derived chars. This comparative study could also provide principle for sorbent selection during other solid waste disposal containing heavy metals. Computational simulations explored the active sites and morphological alterations of additives at varying temperatures, establishing a theoretical basis for selecting appropriate pyrolytic parameters. The adsorption processes of kaolin and CaO for heavy metals exhibited opposite electron transfer directions, resulting in the formation of distinct types of covalent bonds. This disparity accounted for the differential adsorption selectivity of Si/Al-based and Ca-based additives towards various heavy metals. This research presented new ideas for developing targeted in-furnace sorbents during pyrolysis.

Experimental study of single-phase change material thermal diode based on calcium chloride hexahydrate

Phase change material thermal diodes designed on the basis of different heat transfer forms and coefficients caused by different phase transition degrees in opposite heat transfer directions are considered as potential thermal management devices. However, the use of a variety of materials or only relying on numerical simulation research makes its structure complex or idealized, which reduces the possibility of practical application. Therefore, in this work, a simple thermal diode structure containing only CaCl<sub>2</sub>·6H<sub>2</sub>O single-phase variable material is proposed in combination with changes in heat transfer form and heat transfer coefficient in solid-liquid phase change and natural convection process. The corresponding device is prepared, and a steady-state heat flux test system is set up for experimental study, the measured results are close to those recorded in the literature with good accuracy. The influence of the temperature difference between hot end and cold end and the direction of positive heat transfer and negative heat transfer on the thermal rectification effect of the thermal diode are studied experimentally. The results show that the heat flux of the thermal diode decreases with the decrease of the difference in temperature between the cold source and hot source, and the thermal rectification ratio reaches to 1.58 when the forward and reverse along the antigravity direction and gravity direction, respectively. The optimal cold source temperature range is 20–25 ℃, which is close to room temperature. The proposed phase change material thermal diode structure has a certain application potential in energy saving and thermal management of building.

Occurrence and Trophic Transfer of Polychlorinated Naphthalenes (PCNs) in the Arctic and Antarctic Benthic Marine Food Webs.

Information about the occurrence and trophic transfer of polychlorinated naphthalenes (PCNs) in polar ecosystems is vital but scarce. In this study, PCNs were analyzed in benthic marine sediment and several biological species, collected around the Chinese polar scientific research stations in Svalbard in the Arctic and South Shetland Island in Antarctica. Total PCNs in biota ranged from 28 to 249 pg/g of lipid weight (lw) and from 11 to 284 pg/g lw in the Arctic and Antarctic regions, respectively. The concentrations and toxic equivalent (TEQ) of PCNs in polar marine matrices remained relatively low, and the compositions were dominated by lower chlorinated homologues (mono- to trichlorinated naphthalenes). Trophic magnification factors (TMFs) were calculated for congeners, homologues, and total PCNs in the polar benthic marine food webs. Opposite PCN transfer patterns were observed in the Arctic and Antarctic regions, i.e., trophic dilution and trophic magnification, respectively. This is the first comprehensive study of PCN trophic transfer behaviors in remote Arctic and Antarctic marine regions, providing support for further investigations of the biological trophodynamics and ecological risks of PCNs.

A thermal contact model encompassing near-field effects of multi-interface TEGs in hypersonic conditions

High efficiency heat harvest of hypersonic vehicles claims elaborate design of thermoelectric (TE) conversion process. A thermoelectric generator (TEG) contains multi-interfaces in the heat transfer path and the interfacial thermal contacts with certain amount of nanoscale effects have significant influence on its TE conversion process. In this paper, a thermal contact model encompassing near-field thermal radiation (NFTR) effects of TEGs with heterogeneous interfaces between substrates, electrodes and TE legs is established and experimentally validated in hypersonic conditions. First, a real-topology-based thermal contact resistance (TCR) prediction model is developed and the far- and near-field radiative heat transfer at heterogeneous interfaces is considered by the fluctuational electrodynamics, and the model is validated by direct and indirect experimental measurements. Second, the effects of average interfacial temperature, clearance distance and opposite heat transfer paths on the thermal radiation are analyzed, and the influences of average interfacial temperature, loading pressure and clearance mediums on the TCR are then clarified. Third, the TCR is equivalently considered in a TEG performance evaluation model and the NFTR effects is quantitatively counted. The result shows that: with the consideration of the NFTR, the TCRs between TE legs and electrodes, substrates and electrodes decrease by about 3.90% to 17.0% and 0.510% to 6.40% under vacuum clearance, 1.30% to 5.50% and 0.220% to 2.00% under air clearance, respectively; and the maximum output power of the TEG increases by about 8.02% and 1.29% under vacuum and air clearance (0.1 MPa, 650 K), respectively.

Impact of environmental policy on the innovation of SMEs: Chinese evidence

As environmental concerns continue to grow worldwide, the role of environmental policy in promoting sustainable development has become increasingly important. This study examines the impact of environmental policy on the innovation of small and medium-sized enterprises (SMEs) in China, a country where environmental regulation has been rapidly expanding in recent years. The analysis employs a regression model that controls for various firm-level and environmental factors that may affect innovation. A loan guarantee may boost an SME’s chances of acquiring borrowed funds, the number of loans obtained, expenses, capital equipment expenditures, and TFP by 2%, 17.4%, 7.6%, 6.16%, and 5.26%, respectively. Furthermore, the influence of information networks on performance is examined. Environmental policy and open innovation activity, opposite transfer, investor interactions, and SMEs’ success are all examined, with a focus on Chinese SMEs. The findings suggest that policymakers should consider designing more targeted and flexible environmental policies that provide incentives for SMEs to innovate and adopt sustainable practices, while minimizing potential negative impacts on their competitiveness and financial performance.

Phonetic and Lexical Crosslinguistic Influence in Early Spanish–Basque–English Trilinguals

AbstractA central question in multilingualism research is how multiple languages interact. Most studies have focused on first (L1) and second language (L2) effects on a third language (L3), but a small number of studies dedicated to the opposite transfer direction have suggested stronger L3 influence on L2 than on L1 in postpuberty learners. In our study, we provide further support for stronger L3‐to‐L2 than L3‐to‐L1 influence and show that it extends to (a) phonetics and the lexicon and (b) childhood learners. Fifty Spanish–Basque–English trilingual adults who had acquired Spanish from birth and Basque between 2 to 4 years of age through immersion participated in a speeded trilingual switching task measuring production of voice onset time and lexical intrusions. Participants experienced more phonetic and lexical crosslinguistic influence from L3 English during L2‐Basque production than during L1‐Spanish production. These findings show that even highly proficient early bilinguals experience differential influence from a classroom‐taught L3 to L1 and to L2.

Charge transfer driving interfacial reconstructions in perovskite oxide heterostructures

Charge transfer in perovskite oxide heterostructures could break the delicate balance among charge, spin, orbital and lattice order at the interface, producing exotic phenomena that cannot be observed in bulk materials. Here, opposite interfacial charge transfer directions are observed in SrIrO3/NdNiO3 and SrIrO3/LaNiO3 3d/5d perovskite heterostructures. This is accompanied with an inverse change of Ni eg orbital polarization and Ni-O pd hybridization across the interface, by stretching/compressing the out-of-plane Ni-O bond in the opposite internal electrical field due to the opposite electron transfer direction. These interfacial reconstructions finally bring about a manipulation on the transport and magnetic characteristics. This work reveals that A site cation in perovskite heterostructures could be a knob to control the interfacial charge transfer direction, and the 3d/5d perovskite interfaces are excellent platform to study the complex interplay between various order parameters and stimulate novel interfacial effects.

Investigating valley-dependent current generation due to asymmetric energy dispersion for charge-transfer from a quantum dot to single-walled carbon nanotube

Single-wall carbon nanotubes (SWCNT), which consist of a two-dimensional hexagonal lattice of carbon atoms, possess unique mechanical, electrical, optical and thermal properties. SWCNT can be synthesized in diverse chiral indexes to determine certain attributes. This work theoretically investigates electron transport in different directions along SWCNT. The electron studied in this research transfers from the quantum dot that can possibly move to the right or left direction in SWCNT with different valley-dependent probability. These results show that valley polarized current is present. The valley current in the right and left directions has a composition of valley degrees of freedom where its components (K and K′) are not identical. Such a result can be traced theoretically by certain effects. That firstly is the curvature effect on SWCNT in which the hopping integral between pi electrons from the flat graphene is altered, and another is curvature-inducing sigma -pi mixture. Due to these effects, the band structure of SWCNT is asymmetric in certain chiral indexes leading to the asymmetry of valley electron transport. Our results exhibit that the zigzag chiral indexes is the only type making electron transport symmetrical that is different to the result from the other chiral index types which are the armchair and chiral. This work also illustrates the characteristic of the electron wave function propagating from the initial point to the tip of the tube over time, and the current density of the probability in specific times. Additionally, our research simulates the result from the dipole interaction between the electron in QD and the tube that impacts the lifetime of the electron being in QD. The simulation portrays that more dipole interaction encourages the electron transfer to the tube, thereby shortening the lifetime. We as well suggest the reversed electron transfer from the tube to QD that the time duration of such transfer is much less than the opposite transfer owing to the different orbital of the electron’s states. Valley polarized current in SWCNTs may also be used in the development of energy storage devices such as batteries and supercapacitors. The performance and effectiveness of nanoscale devices, including transistors, solar cells, artificial antennas, quantum computers, and nano electronic circuits, must be improved in order to achieve a variety of benefits.

Peculiarities of Convective Heat and Mass Transfer in Magnetic Nanofluids

Abstract Heat transfer enhancement due to thermomagnetic convection arising in nonisothermal electrically nonconducting ferrofluids placed in an external magnetic field is reviewed with an emphasis on realistic applications. It is shown that due to a complex composition of such fluids numerous internal physical processes can lead to directly opposite heat transfer trends. Physical factors influencing such processes are identified. It is concluded that while the complexity of such mechanisms makes designing ferrofluid-based heat exchangers a delicate task when done correctly, it ensures manyfold improvement of heat removal characteristics of such devices compared with their natural convection counterparts. This short review aims to provide a concise starting-point summary of ferrohydrodynamic effects and processes that need to be taken into account when designing practical applications.

From Microtiter Plates to Droplets-There and Back Again.

Droplet-based microfluidic screening techniques can benefit from interfacing established microtiter plate-based screening and sample management workflows. Interfacing tools are required both for loading preconfigured microtiter-plate (MTP)-based sample collections into droplets and for dispensing the used droplets samples back into MTPs for subsequent storage or further processing. Here, we present a collection of Digital Microfluidic Pipetting Tips (DMPTs) with integrated facilities for droplet generation and manipulation together with a robotic system for its operation. This combination serves as a bidirectional sampling interface for sample transfer from wells into droplets (w2d) and vice versa droplets into wells (d2w). The DMPT were designed to fit into 96-deep-well MTPs and prepared from glass by means of microsystems technology. The aspirated samples are converted into the channel-confined droplets’ sequences separated by an immiscible carrier medium. To comply with the demands of dose-response assays, up to three additional assay compound solutions can be added to the sample droplets. To enable different procedural assay protocols, four different DMPT variants were made. In this way, droplet series with gradually changing composition can be generated for, e.g., 2D screening purposes. The developed DMPT and their common fluidic connector are described here. To handle the opposite transfer d2w, a robotic transfer system was set up and is described briefly.

Nonlinear forced vibration analysis of a multi-cracked Euler-Bernoulli curved beam with inclusion of damping

Curved beams that have advantages of excellent bearing capacity and beautiful appearance are widely applied in various engineering constructions. This paper studies nonlinear forced vibration of a multi-cracked Euler-Bernoulli curved beam (ECB) with damping effects and derives the closed-formed analytical solution of steady-state forced vibration of the multi-cracked curved beam by means of Green’s functions. Based on the mathematical structure of Green’s functions, a new transfer matrix method called the opposite coordinate two-step transfer matrix (OCTM) method is proposed. By employing the OCTM method and Laplace transform method, Green’s functions of ECBs with one crack and multiple cracks are obtained. The vibration model of the multi-cracked ECB degenerates into a healthy curved beam vibration model when depths of cracks are set to zero. The healthy curved beam vibration model can be reduced to a straight beam vibration model bysetting the radius of curvature to infinity. The present analytical solution is verified by experimental results, finite element results, and analytical solutions in the literature in this work. Effects of some important physical parameters, such as the crack depth and location, on vibration of a curved beam with one crack are investigated. Interaction between two cracks of a curved beam is also investigated.

A Study on the Effect of the Substituent against PAK4 Inhibition Using In Silico Methods.

The intrinsic inductive properties of atoms or functional groups depend on the chemical properties of either electron-withdrawing groups (EWGs) or electron-donating groups (EDGs). This study aimed to evaluate in silico methods to determine whether changes in chemical properties of the compound by single atomic substitution affect the biological activity of target proteins and whether the results depend on the properties of the functional groups. We found an imidazo[4,5-b]pyridine-based PAK4 inhibitor, compound 1, as an initial hit compound with the well-defined binding mode for PAK4. In this study, we used both experimental and in silico methods to investigate the effect of atomic substitution on biological activity to optimize the initial hit compound. In biological assays, in the case of EWG, as the size of the halogen atom became smaller and the electronegativity increased, the biological activity IC50 value ranged from 5150 nM to inactive; in the case of EDG, biological activity was inactive. Furthermore, we analyzed the interactions of PAK4 with compounds, focusing on the hinge region residues, L398 and E399, and gatekeeper residues, M395 and K350, of the PAK4 protein using molecular docking studies and fragment molecular orbital (FMO) methods to determine the differences between the effect of EWG and EDG on the activity of target proteins. These results of the docking score and binding energy did not explain the differences in biological activity. However, the pair-interaction energy obtained from the results of the FMO method indicated that there was a difference in the interaction energy between the EWG and EDG in the hinge region residues, L398 and E399, as well as in M395 and K350. The two groups with different properties exhibited opposite electrostatic energy and charge transfer energy between L398 and E399. Additionally, we investigated the electron distribution of the parts interacting with the hinge region by visualizing the molecular electrostatic potential (MEP) surface of the compounds. In conclusion, we described the properties of functional groups that affect biological activity using an in silico method, FMO.

Gastrocnemius Transfer for Foot Drop versus Traditional Tibialis Posterior Transfer: Results from a Long-term Follow-up in a Randomized Controlled Trial

BACKGROUND: Traditional methods of treating patients with foot drop include tibialis posterior muscle and peroneus longus muscle transfer. Although still considered as the gold standard, tibialis posterior transfer is often associated with inadequate dorsiflexion, ankle instability as well as difficulty in walking without support or splint. This is because the forces generated by the posterior group of muscles are far greater than the anterior ones, and simple transfer of the relatively weak tibialis posterior is insufficient to counteract this difference. In this study, we use gastrocnemius muscle to neutralize the cumulative forces of posterior compartment by transferring it to the anterior compartment. METHODS: Thirty-eight patients were included in this study conducted between 2016 and 2020. They were randomly divided into two equal groups. The patients in the group A underwent transfer of the lateral, medial, or both heads of the gastrocnemius muscle to the tendons of anterior compartment. On the other hand, the patients in the group B underwent the standard transfer of the tibialis posterior tendon to the anterior compartment by fixing it to one of the tarsal bones. Patients were followed up for at least 1 year to assess range of motion, toes movement, and ability to walk without splint or support. Further, functional assessment was done by utilizing the American Orthopaedic Foot & Ankle Society score. RESULTS: Fifteen patients in group A showed excellent results with a good active range of motion of >40 degrees showing no signs of ankle instability and were able to walk without support or splint with no inversion or eversion abnormalities. Two patients were recorded to have good results with >30 degrees of active range of motion. They were able to walk without support and a stable gait. In one case treated with unilateral gastrocnemius, the patient suffered from recurrence. He underwent the opposite gastrocnemius transfer and was ultimately able to walk without support. Active dorsiflexion in patients treated in group A was 17.1 ± 1.3 as opposed to 8.8 ± 1.9 in group B; this difference was significantly better in group A (P < 0.01). Similarly mean active range of motion in group A was 47.2 in group A compared with 38.6 in group B, the difference being significant (P < 0.01). Mean American Orthopaedic Foot & Ankle Society scores significantly improved from 63.4 to 87.8 in the group A and from 65.4 to 70.2 points at final follow-up, denoting that the results were significantly better in the former group (P < 0.001). CONCLUSIONS: Surgical failure and recurrence in patients undergoing standard procedures for foot drop is a commonly found problem. Transferring gastrocnemius muscle to the tendons of anterior compartment not only improves postoperative dorsiflexion with good range of motion, but also provides a stable ankle that allows the patient to walk without a splint or support. This technique should be utilized more often in treating patients with foot drop because it gives better long-term results with no postoperative complications.

Enhanced solar water splitting using plasmon-induced resonance energy transfer and unidirectional charge carrier transport.

Solar water splitting by photoelectrochemical (PEC) reactions is promising for hydrogen production. The gold nanoparticles (AuNPs) are often applied to promote the visible response of wideband photocatalysts. However, in a typical TiO2/AuNPs structure, the opposite transfer direction of excited electrons between AuNPs and TiO2 under visible light and UV light severely limits the solar PEC performance. Here we present a unique Pt/TiO2/Cu2O/NiO/AuNPs photocathode, in which the NiO hole transport layer (HTL) is inserted between AuNPs and Cu2O to achieve unidirectional transport of charge carriers and prominent plasmon-induced resonance energy transfer (PIRET) between AuNPs and Cu2O. The measured applied bias photon-to-current efficiency and the hydrogen production rate under AM 1.5G illumination can reach 1.5% and 16.4 μmol·cm-2·h-1, respectively. This work is original in using the NiO film as the PIRET spacer and provides a promising photoelectrode for energy-efficient solar water splitting.

Ultralong π-Conjugated Bis(terpyridine)metal Polymer Wires Covalently Bound to a Carbon Electrode: Fast Redox Conduction and Redox Diode Characteristics.

We developed an efficient and convenient electrochemical method to synthesize π-conjugated redox metal-complex linear polymer wires composed of azobenzene-bridged bis(terpyridine)metal (2-M, M = Fe, Ru) units covalently immobilized on glassy carbon (GC). Polymerization proceeds by electrochemical oxidation of bis(4′-(4-anilino)-2,2′:6′,2″-terpyridine)metal (1-M) in a water–acetonitrile–HClO4 solution, affording ultralong wires up to 7400 mers (corresponding to ca. 15 μm). Both 2-Fe and 2-Ru undergo reversible redox reactions, and their redox behaviors indicate remarkably fast redox conduction. Anisotropic hetero-metal-complex polymer wires with Fe and Ru centers are constructed via stepwise electropolymerization. The cyclic voltammograms of two hetero-metal-complex polymer wires, GC/[2-Fe]–[2-Ru] (3) and GC/[2-Ru]–[2-Fe] (4), show irreversible redox reactions with opposite electron transfer characteristics, indicating redox diodelike behavior. In short, the present electrochemical method is useful to synthesize polymer wire arrays and to integrate functional molecules on carbon.

Asymmetric interlateral transfer of motor learning in unipedal dynamic balance.

Interlateral transfer of learning between the legs in body balance training is a topic of theoretical and practical interest, but it has been left untouched in previous research. In this investigation, we aimed to evaluate the magnitude and asymmetry of interlateral transfer of balance stability following the practice of a challenging task of unipedal support on an unstable base. Thirty participants (18-30years old) were assigned to two groups practicing either with the right or the left leg. Training consisted of a single practice session of unipedal balance on a platform free to sway in the anteroposterior direction. Balance time (off ground) of either leg in 10-s trials was compared across pre-test, post-test, and 7-day retention. Post-test indicated that both groups had similar performance gains with the trained leg, and equivalent transfer to the transfer leg. Analysis of retention indicated further balance improvement with both transfer legs, while practice with the right leg led to the superior transfer to the untrained leg as compared to the opposite transfer direction. These results suggest that persistent transfer of learning effects for unipedal dynamic balance is bilateral but more prominent in the right-to-left direction.

Prediction of transient wellbore cement circulating temperature distribution using CFD simulation

Accurate prediction of the cement slurry temperature while being circulated downhole is critical for a successful cement job. Failure to predict the cement slurry temperature correctly may result in premature or delayed cement setting. Due to the practical limitations of using temperature sensors for direct measurement and the complexity of the bottomhole circulating conditions, it is difficult to gather accurate information about how the temperature of cement slurry changes as it is being circulated through the well. To overcome these challenges and help with designing a cement system more accurately, a computational fluid dynamics (CFD) model is developed. The model simulates the balanced-plug cementing operation, which considers the continuous displacement of the drilling fluid by the cement slurry and the cement slurry by water. The CFD model predicts the transient changes in the temperatures of the cement slurry and near wellbore formation during this displacement process involving three different fluids. A new dynamic mesh method was developed to effectively handle the interface mixing of different fluids, and thus model the three-fluid displacement process in the annulus more realistically. The CFD model can also deal with complex well conditions such as deviated wellbores, variable geothermal gradients and formation rock properties. Most importantly, in the absence of the measurements allowing direct monitoring of the downhole conditions, the new CFD model allows for continuous monitoring of downhole transient fluid and formation temperature at any position along the wellbore. The results of CFD transient simulations indicate that the bottomhole circulation temperature (BHCT) values predicted by using API method are significantly overestimated. The highest cement slurry temperature in the annulus was observed at some distance above the bottom of the well. Results also confirmed the existence of an equilibrium plane (extending horizontally) into the formation across which a temperature reversal was observed. The formations above and below the equilibrium plane have opposite heat transfer patterns. The depth of the equilibrium plane rises steadily while its temperature gradually decreases as the circulation continues. The change of the cement/drilling fluid interface temperature is traced dynamically. CFD simulation is proven to be a realistic and reliable approach for prediction of the cement circulating temperature and can be easily used in combination with real time operational data. Practical guidelines and solutions derived from the simulation results can be useful for improved cement job design in field applications.

Thermodynamic Evaluation of Chemical Transport of VSe2 and ZrSe2 with Сl2 and I2 as Transporting Agents

To study chemical transport and refine synthetic routes, single crystals of vanadium and zirconium diselenides were grown by the chemical transport reaction method using I2 and Cl2 as transporting agents. The thermodynamic parameters of chemical transport have been evaluated, and the mass transfer direction in a growth ampoule has been determined. The phase composition of the samples has been examined by X‑ray powder diffraction. Analysis of X-ray powder diffraction patterns of samples from the low- and high-temperature zones of the growth ampoule has confirmed the predictions based on thermodynamic calculations. With both transporting agents, ZrSe2 transport occurs from the cold to the hot zone of the ampoule, while the direction of VSe2 transport depends on the nature of the transporting agent. With I2 as a transporting agent, transport occurs from the hot to the cold zone of the ampoule, while with Cl2, in the opposite mass transfer direction is observed. Microphotographs of the samples are consistent with thermodynamic and X‑ray diffraction data. The results can be used to optimize the technology of producing layered transition metal dichalcogenides.

Effect of Copper-Based Spring Alloy Selection on Arc Erosion of Electrical Contacts in a Miniature Electrical Switch

A spring beam in a miniature electrical switch enables the two electrical contacts to either close or separate and supplies both current and necessary contact pressure between the contacts. Arc erosion and material transfer between the contacts occur, and those aspects depend on various parameters including the kinematics of the contacts. Therefore, the mechanical properties of the spring beam will affect the arc erosion and material transfer, but this topic has not been well studied. In this study, the material transfer phenomena between two AgCu contacts attached to a spring beam made of three different copper-based strip alloys were investigated after 30,000 switching operations under 12 V and 9 A in a direct-current resistive load circuit. For spring beams made of beryllium copper (BeCu) and titanium copper (TiCu) alloy, the material transfer occurred from the cathode to the anode. However, an opposite material transfer occurred for a spring beam made of Corson-type (CuNiSi) alloy. The make- and break-arc voltage waveforms were analyzed, and the results showed that the changes in arcing behaviors depend on the spring beam material. The properties of the spring beam materials responsible for the changed arcing behaviors are discussed and their relationship with the observed contact arc erosion and material transfer is analyzed.