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The emerging semiconductor spintronics has offered a practical routine for developing high-speed and energy-efficient electronic and optoelectronic devices. GaN holds broad prospects for room-temperature spintronic applications due to its weak spin scattering and moderate spin–orbit coupling. However, the development of GaN-based spintronic devices is still hindered by the relatively low spin injection efficiency and gate controllability. In this study, gate-modulated spin transport was achieved in a highly spin-polarized GaN-based non-local spin valve. A maximum spin diffusion length of 510 nm and a high spin polarization of 14.1% was obtained with the CoFeB/MgO tunnel spin injector. By applying gate voltages from −3 to +3 V, the spin-dependent magnetoresistance can be tuned in the range of 1.6–3.9 Ω. The modulation is attributed to the controllable spin relaxation of electrons by the gate electric field. This work has demonstrated high spin polarization and exceptional electric controllability in GaN, pushing forward the research in spin field-effect transistors.

Transition-metal dichalcogenides with intrinsic spin-valley degree of freedom have enabled great potentials for valleytronic and optoelectronic applications. However, the degree of valley polarization is usually low under nonresonant excitation at room temperature due to the phonon-assisted intervalley scattering. Here, achiral and chiral Au arrays are designed to enhance the optical response and valley polarization in monolayer and bilayer WS2. A considerable band edge emission with 7 times increment is realized under the resonant coupling with Au dimer-prism arrays. Valley polarization enhancement is quantitatively predicted by the inherent mechanisms from elevated electromagnetic field intensity and radiation efficiency and further realized in polarized photoluminescence. A tunable valley polarization up to 30.0% is achieved in bilayer WS2 under a nonresonant excitation at room temperature. All of these results provide a promising route toward the development of room-temperature valley-dependent optoelectronic devices.

Memristors with non-volatile storage performance and simulated synaptic functions are regarded as one of the critical devices to overcome the bottleneck in traditional von Neumann computer architecture. van der Waals heterostructures integrating excellent properties of two-dimensional semiconductor materials, possessing controllable optoelectronic properties and high compatibility with conventional microelectronic technology, have paved a new way for the development of advanced memristors. Herein, we demonstrate a two-dimensional planar memristor with both electrical and optical controllability based on ReS2/WS2 van der Waals heterostructure. The device shows a typical unipolar non-volatile behavior with a high Ron/Roff ratio, multiple tunable resistance states, and desirable endurance and retention. It also successfully realizes biological synaptic functions and plasticity, including spike rate-dependent plasticity and paired-pulse facilitation. Furthermore, the developed device shows a significant gate controllability and a remarkable optical tunability. The superior performance is attributed to the unique optoelectronic property and the interlayer interaction in the heterostructure. The research presented here demonstrates the potential of two-dimensional van der Waals heterostructures for high-performance memristor applications and further developments in modelling biological synapses.

Simple sol-gel method and microwave method were used to prepare two-dimensional Pd1Snx/TiO2-GO catalyst with high catalytic activity and strong resistance to CO poisoning. The morphology and structure of Pd1Snx/TiO2-GO catalyst were characterized by TEM, XRD and XPS. It was shown that the spindle TiO2 are uniformly fixed on the GO sheets and can still maintain the morphology after Pd and Sn nanoparticles loading. At the same time, Pd and Sn NPs were both uniformly anchored on the surface of the composite carrier according to EDS element mapping. The two-dimensional composite support TiO2-GO formed by the spindle-shaped TiO2 grown uniformly in-situ on GO helps to achieve uniform anchoring of metal nanoparticles. By introducing the second metal Sn, the electronic structure of Pd can be modified to provide more oxygen-containing groups, which leads to a more complete ethanol oxidation process. Through electrochemical tests, it can be found that Pd1Snx/TiO2-GO had excellent catalytic activity, anti-poisoning ability and long-term stability for ethanol electrooxidation in alkaline environment. The residual current density of Pd1Sn0.40/TiO2-GO is 7 times than that of PdSn/C (JM). Especially, the residual current density of Pd1Sn0.40/TiO2-GO catalyst only decreased by 16.7% after continuously scanned by cyclic voltammetry for 8 times.

The manipulation of spin and valley degree of freedom in two-dimensional materials is desirable for emerging applications in next-generation electronics. Here, we report a regulation of the spin splitting in monolayer antiferromagnetic MnPSe3 through stacking van der Waals (vdW) heterostructures with transition-metal dichalcogenides (TMDs). Different TMDs including Janus MoSSe, MoSe2, and MoS2 are engaged and the spin and valley dependences on stacking configurations, interfacial atoms, and interlayer spacings are comprehensively investigated based on first-principles calculations. The results show that spin degeneracy of MnPSe3 can be lifted through the interfacial interaction in the vdW heterostructures. Compared with the MnPSe3 interfacing with traditional TMDs (MoSe2 and MoS2), those with Janus TMDs (MoSSe or MoSeS) have larger spin splitting. A maximal spin splitting of 50.8 meV at valence band maximum is achieved in MoSSe/MnPSe3 heterostructure, and such splitting is further enhanced to 243.0 meV when the interlayer spacing is reduced to 2.9 Å. It is found that the different hybridizations between the d-orbitals of the two inequivalent Mn atoms in MnPSe3 and the above TMDs lead to the occurrence of net magnetic moments, and thus induce spin splitting. This work paves a novel way to modify the spin-valley properties of two-dimensional semiconductors.

Memristors are excellent candidates for non-volatile memory and neuromorphic computing. Controlling the resistive switching polarity in certain materials holds great promise for the design and integration of multifunctional memristors. Here, bipolar and unipolar nonvolatility were realized by modulating the crystal structures, which exhibit high switching ratios, desirable cyclability, and long retention. By investigating the defect level and conductivity difference in single-crystal and polycrystal ReS2, the competition between electric field and Joule heat effects were revealed as the essential mechanism governing the switching process and memristive polarities. These results promote the design of two-dimensional memristors with controllable polarity.

Background The Chinese government has proposed cancer screening guidelines and launched 2 cancer screening programs to improve screening practices. However, the screening participation rates of Chinese women remain low. Exploring the factors affecting breast cancer screening to promote cancer screening is necessary. Objective The aim of this study was to investigate women's satisfaction with healthcare providers and screening practices. Methods A cross-sectional survey was conducted from November 2019 to April 2020 in Changchun, Jilin Province, China. The Medical Care Satisfaction Scale and SERVQUAL were used to quantify women's satisfaction with doctors and nurses, respectively. Results Women's satisfaction with doctors (68.81 ± 11.08; range, 20-100) and with nurses (87.64 ± 16.17; range, 22-110) was moderate. Compared with women who had not participated in screening within the past 2 years, screened women reported higher satisfaction with doctors (P = .026) and nurses (P = .012). Older age (P = .004) was an independent predictor of women's satisfaction with doctors. Similarly, women's education level (P = .049), chronic disease history (P = .029), and physical examination history (P = .039) were 3 independent predictors of women's satisfaction with nurses. Conclusions Future intervention strategies can not only increase the screening rates by providing existing intervention methods but also improve women's satisfaction with healthcare providers to promote screening practices. Implications for practice This article provides a theoretical basis for healthcare providers to increase female screening practices. It also provides references for improving existing intervention methods.

This paper presents an evolution-based hyperheuristic (EHH) for addressing the capacitated location-routing problem (CLRP) and one of its more practicable variants, namely, CLRP with simultaneous pickup and delivery (CLRPSPD), which are significant and NP-hard model in the complex logistics system. The proposed approaches manage a pool of low-level heuristics (LLH), implementing a set of simple, cheap, and knowledge-poor operators such as “shift” and “swap” to guide the search. Quantum (QS), ant (AS), and particle-inspired (PS) high-level learning strategies (HLH) are developed as evolutionary selection strategies (ESs) to improve the performance of the hyperheuristic framework. Meanwhile, random permutation (RP), tabu search (TS), and fitness rate rank-based multiarmed bandit (FRR-MAB) are also introduced as baselines for comparisons. We evaluated pairings of nine different selection strategies and four acceptance mechanisms and monitored the performance of the first four outstanding pairs in 36 pairs by solving three sets of benchmark instances from the literature. Experimental results show that the proposed approaches outperform most fine-tuned bespoke state-of-the-art approaches in the literature, and PS-AM and AS-AM perform better when compared to the rest of the pairs in terms of obtaining a good trade-off of solution quality and computing time.

The Location Routing Problem (LRP), a branch of logistics management, has been addressed in many research papers. However, there are few papers on time-dependent LRP. And only a few of them take fuel consumption into consideration. To reduce the environmental pollution from vehicle emissions and the cost pressure on logistics, a novel model named the time-dependent green location routing problem with time windows (TDGLRP) is developed. Its objective is to minimize costs including opened depot costs, enabled vehicle costs and fuel consumption costs. In TDGLRP the speed and travel times are time-dependent function. A hyper-heuristic algorithm (HH) that consists of two levels, high-level heuristics (HLHs) and low-level heuristics (LLHs), is proposed to solve the TDLGRP. The Tabu Search (TS) algorithm is taken as the high-level selection mechanism, and the Greedy algorithm is taken as the acceptance mechanism. With reference to the Solomon benchmarks, we design a series of TDGLRP instances with 100 client nodes, and analyze the impact of client distribution characteristics on the path. Based on the TDGLRP model and HH, the end of the article gives the solution results of a large-scale instances with 1000 nodes.

To systematically evaluate the effects of decision aids for women facing breast reconstruction decision on decision conflict, decision regret, knowledge, satisfaction, anxiety and depression.Breast reconstruction decision is not good or bad and should be guided by clinical evidence and patient preferences. Decision aids can increase the patient's decision-making enthusiasm and ability, improve the quality of decision and promote shared decision-making between patients and medical staff.Systematic review and meta-analysis.Eight databases were conducted from the establishment of the database until October 2021. The PRISMA checklist was selected for analysis in this paper. The meta-analysis was conducted in Review Manager 5.3. The quality of the studies was assessed using the Cochrane risk-of-bias tool. The result is decision conflict, decision regret, knowledge and other secondary outcomes. Sensitivity analysis and subgroup analysis were also conducted.A total of twelve randomised controlled trials (RCTs) were included in the systematic review and meta-analysis. Meta-analysis revealed that decision aids could significantly reduce decision conflict and decision regret, improve knowledge, satisfaction and depression and had no influence on anxiety.The results of the systematic review and meta-analysis reviewed the positive effect of decision aids on the decision-making of women facing postmastectomy breast reconstruction. In the future, more well-designed RCTs are needed to confirm the effects of decision aids on the decision-making of breast reconstruction and nurses should be encouraged to take part in the development of decision aids in accordance with strict standards and apply them to breast cancer patients considering postmastectomy breast reconstruction.Our study provides evidence for the effectiveness of decision aids on breast reconstruction and points to the important role of healthcare providers in the use of decision aids and in facilitating shared decision-making.

Aims and objectives Review the content, quality and effect of breast cancer screening decision aids (BCS-DAs) in women approximately 50 years of age to provide a basis for the development of DAs. Background Breast cancer screening (BCS) decisions are complex and should vary depending on a woman's risk of breast cancer and her values and preferences. Decision aids (DAs) can help support women and medical staff in shared decision-making (SDM) when solving BCS problems. Design Systematic review and meta-analysis. Methods Four databases were searched starting at the time of establishment of the database to March 2021. The PRISMA checklist was followed. The meta-analysis was carried out using Review Manager 5.3 software. The quality of the studies was assessed using the risk of bias tool recommended by the Cochrane Handbook. The quality of the DAs was assessed using the International Standards for Decision Aid (IPDASi v4.0). Results The search strategy obtained 2024 references. After abstraction and full text screening, a total of seven studies were included. This article systematically reviews the content, quality and effectiveness of DAs in seven RCTs in helping women to make BCS decisions. The DAs were mostly in paper or online form and displayed disease screening information, analysed the benefits and harms of options and clarified the value to patients. Among all the DAs, only one met the minimum quality standards of IPDASi v4.0. Comprehensive analysis shows that DAs can significantly improve knowledge and increase the proportion of women who make informed choices, but they have no effect on screening attitude, intention, decision conflict or regret. Conclusions In the future, nurses should be encouraged to develop DAs in accordance with strict standards and to make them applicable to young women of different backgrounds. Relevance to clinical practice The result may be provide a basis for the development of DAs to promote women's informed screening choices.

Transition-metal dichalcogenides with intrinsic spin-valley degree of freedom have enabled great potentials for valleytronic and optoelectronic applications. However, the degree of valley polarization is usually low under nonresonant excitation at room temperature due to the phonon-assisted intervalley scattering. Here, achiral and chiral Au arrays are designed to enhance the optical response and valley polarization in monolayer and bilayer WS

Among large numbers of transition metal dichalcogenides (TMDCs), monolayer rhenium disulfide (ReS2) is of particular interest due to its unique structural anisotropy, which opens up unprecedented opportunities in dichroic atomical electronics. Understanding the domain structure and controlling the anisotropic evolution of ReS2 during the growth is considered critical for increasing the domain size toward a large-scale growth of monolayer ReS2. Herein, by employing angle-resolved Raman spectroscopy, we reveal that the hexagonal ReS2 domain is constructed by six well-defined subdomains with each b-axis parallel to the diagonal of the hexagon. By further combining the first-principles calculations and the transmission electron microscopy (TEM) characterization, a dislocation-involved anisotropic evolution is proposed to explain the formation of the domain structures and understand the limitation of the domain size. Based on these findings, growth rates of different crystal planes are well controlled to enlarge the domain size, and moreover, single-crystal domains with a triangle shape are obtained. With the improved domain size, large-scale uniform, strictly monolayer ReS2 films are grown further. Scalable field-effect transistor (FET) arrays are constructed, which show good electrical performances comparable or even superior to that of the single domains reported at room temperature. This work not only sheds light on comprehending the novel growth mechanism of ReS2 but also offers a robust and controllable strategy for the synthesis of large-area and high-quality two-dimensional materials with low structural symmetry.

Two-dimensional transition-metal dichalcogenides (TMDCs) possess unique electronic and optical properties, which open up a new opportunity for atomically thin optoelectronic devices. Synthesizing l...

This paper addresses a new variant of location-routing problem (LRP), namely the LRP with simultaneous pickup and delivery (LRPSPD). A hyper-heuristic approach based on iterated local search (ILS-HH) is introduced to automatically optimize the LRPSPD. On basis of the novel proposed framework of hyper-heuristic, four selections mechanisms and five activation strategies are developed to examine the performance of the proposed framework. Three types computational evaluations were carried out and several conclusions can be drawn: (1) the proposed framework performs better than the classical one with performing several heavy-duty combinations of strategies in terms of solution quality and computing time; (2) different activated strategies have slight (not significant) effect on exploiting best solutions; (3) FRR-MAB-TS (fitness ratio rank based on multi-armed bandit with tabu search) works best among all selection methods. Moreover, the proposed approach could provide competitive, even better results compared to fine-tuned bespoke state-of-the-art approaches.

The breakdown characteristics of AlGaN/GaN high-electron-mobility transistors are one of the most important parameters for practical applications when used as power devices. In this study, the relationship between the relative permittivity of the passivation layers and the breakdown voltages in the off state was investigated in detail using TCAD simulations. An embedded double-passivation layer was proposed to enhance the breakdown voltage of the devices. This device structure was realized using an additional step of etching and opening holes on the edge of the gate metal, followed by the deposition of the embedded passivation films. The extracted electric field shows that this embedded passivation layer not only can improve the breakdown characteristics of the device like using a single high-k passivation film but also presents as the function of the ‘Metal Field Plate’, additionally resulting in the enlarged breakdown voltage. Further theoretical simulations indicated that the greater the difference between the dielectric constants of the high/low passivation materials, the higher the breakdown voltage can be obtained.

AIMS To analyse the effect of decision aids (DAs) used by pregnant women on prenatal testing decisions. DESIGN Systematic review and meta-analysis. DATA RESOURCES We searched Embase, PubMed, Web of Science and the Cochrane Central Library ending October 2020. REVIEW METHODS Papers were selected for analysis in accordance with the PRISMA guidelines. The meta-analysis was carried out using Review Manager 5.3 software. The quality of the studies was assessed using the risk of bias tool recommended by the Cochrane Handbook. The result is knowledge, decision conflict, anxiety and other secondary outcomes. RESULTS A total of 18 studies were included in the systematic review and meta-analysis. Comprehensive analysis showed that DAs could significantly improve knowledge and decision-making satisfaction, reduce decision conflict, increase the proportion of women who make informed choice and had no influence on anxiety and decision regret. CONCLUSIONS This article systematically reviewed the positive effect of DAs on the decision-making of pregnant women facing prenatal testing. In the future, nurses should be encouraged to develop DAs in accordance with strict standards and apply them to pregnant women of different backgrounds. IMPACT There is a growing consensus that health care should be patient-centred, and the values and preferences of pregnant women who undergo prenatal testing need to be incorporated into the clinical decision-making process. This review reports that the use of DAs can increase pregnant women's chances of participating in prenatal testing decisions and may improve the quality of their decision-making. It also provides information on the role and practice of nurses in promoting evidence-based prenatal testing for DAs.

We report tunable optical performances of gallium selenide (GaSe) layers in phonon vibrations, band edge emission, circular polarization, and anisotropic response via strain manipulation. By applying a uniaxial tensile strain, frequency shift and peak broadening are observed in Raman spectra. A shrink in bandgap is demonstrated in photoluminescence (PL) spectra and confirmed by first-principles calculations. A continuously growing circular polarization from 3.8% to 37.9% is detected at room temperature when the tensile strain is increased from 0% to 0.35%, which is almost a ten-fold enhancement compared with that under the non-resonant excitation. Through the theoretical calculations, the decrease in exciton lifetime is revealed to be responsible for the overwhelming enhanced circular polarization. By deforing the lattices of GaSe layers, the Raman intensity was found to be suppressed in the strain direction. The intrinsic fourfold-symmetry of the E2g1 mode in angle-dependent Raman spectra is tuned to a two-fold symmetry. An anisotropic PL response is further regulated by changing the structural symmetry of GaSe lattices. A maximal polarization of 66.0% is achieved when the detection polarizations are perpendicular to the strain direction. All the findings in this study suggest a route for tuning the optical properties, particularly the polarized response in two-dimensional (2D) materials, and provide a strategy for developing flexible and anisotropic 2D optical devices.

Identically sized $\mathrm{Co}$ quantum dots (QDs) are constructed on monolayer tungsten disulfide (${\mathrm{WS}}_{2}$), forming coupled heterostructures. Topographical images investigated by means of in situ scanning tunneling microscopy (STM) show a bias-dependent feature. First-principles-calculated binding energies combined with the simulated STM images identify that the $\mathrm{Co}$ QDs possess a unique magic number, with a tetrahedral ${\mathrm{Co}}_{4}$ configuration. Numerical differential conductance measured by means of scanning tunneling spectroscopy indicates a p-type doping and an Ohmic contact property for the ${\mathrm{Co}}_{4}/{\mathrm{WS}}_{2}$ system. The mechanism of the transport and conduction properties of the coupled heterostructures is further revealed by analyzing the work functions and interfacial interaction. Our findings offer some references for the controlled fabrication of identically sized zero-dimensional and two-dimensional heterostructures, and we propose a feasible strategy for Ohmic interface contact in nanodevices.

Two-dimensional (2D) 2H-1 T′ heterojunctions based on transition-metal dichalcogenides have attracted great attention due to their special interface structures and novel properties. Understanding the growth mechanism and the interface structures is essential for their controllable growth. In this work, we successfully synthesize lateral and vertical MoS2/ReS2 heterojunctions by using a two-step chemical vapor deposition (CVD) method, and deeply explore the evolution of the structure. It is found that the growth mode of heterojunction undergoes a transition from lateral epitaxy to vertical stacking under a high Re/S ratio during the growth. Furthermore, the interface structure is greatly determined by the edge shape of MoS2 core. Two kinds of structures, with the b-axis of 1 T′ ReS2 shell parallel to the (1 0 0) and (0 1 0) plane of MoS2 core respectively, are observed. Meanwhile, by comparing with MoS2 monolayer, MoS2/ReS2 heterostructures possess a reduced emission intensity due to the carrier transfer. This work provides a robust and controllable strategy for the synthesis of heterostructures with different phase structures.

Group-IIIA metal-monochalcogenides with the enticing properties have attracted tremendous attention across various scientific disciplines. With the aim to satisfy the multiple demands of device applications, here we report a design framework on GaSe monolayer in an effort to tune the electronic and magnetic properties through a dual modulation of vacancy doping and electric field. A half-metallicity with a 100% spin polarization is generated in a Ga vacancy doped GaSe monolayer due to the nonbonding 4p electronic orbital of the surrounding Se atoms. The stability of magnetic moment is found to be determined by the direction of applied electric field. A switchable magnetic configuration in Ga vacancy doped GaSe monolayer is achieved under a critical electric field of 0.6 V/A. Electric field induces redistribution of the electronic states. Finally, charge transfers are found to be responsible for the controllable magnetic structure in this system. The magnetic modulation on GaSe monolayer in this work offers some references for the design and fabrication of tunable two-dimensional spintronic device.

Developing highly active Pd-based nanocatalysts with a well-organized structure is desired for direct alcohol fuel cell commercialization. In this study, room temperature seed mediated growth strategy has been successfully developed to prepare ternary Pd@Cdx-Agy core-shell as advanced novel non-Pt anode nanocatalysts for ethanol oxidation reaction EOR in alkaline electrolyte. The introduction of oxophilic Cd and Ag metals into Pd nanocatalysts can reduce the adsorption energy of OHads on the Pd@Cdx-Agy nanocatalysts and inhibit the COads on the Pd surface. Morphological characterization demonstrates that the as-synthesized Pd@Cdx-Agy nanocatalysts are well-organized core-shell nanostructure with Pd NPs as the core and Cd-Ag alloy as the shell. Moreover, electrochemical results indicate that the Pd@Cd1-Ag1 core-shell catalyst exhibit a remarkable electrochemical activity ( 2995.76 mA mg Pd − 1 ), excellent CO tolerance and long-term durability compared to those of Pd@Cd ( 1285.9 mA mg Pd − 1 ), Pd@Ag ( 2423.52 mA mg Pd − 1 ) and commercial Pd/C (JM) ( 477.4 mA mg Pd − 1 ) nanocatalysts. The excellent catalytic activity and stability of Pd@Cd1-Ag1 nanocatalyst can be associated to their huge electrochemical active surface area, positive influence of Cd-Ag NPs on Pd NPs and the unique well-organized core-shell nanostructure. These results suggested that the as-synthesized Pd@Cdx-Agy core-shell could serve as advanced catalysts towards alkaline DEFCs.

We investigate the electric-field-dependent optical properties and electronic behaviors of GaS monolayer by using the first-principles calculations. A reversal of the dipole transition from E//c to E⊥c anisotropy is found with a critical external electric field of about 5 V/nm. Decomposed projected band contributions exhibit asymmetric electronic structures in GaS interlayers under the external electric field, which explains the evolution of the absorption preference. Spatial distribution of the partial charge and charge density difference reveal that the strikingly reversed optical anisotropy in GaS ML is closely linked to the additional crystal field originated from the external electric field. These results pave the way for experimental research and provide a new perspective for the application of the monolayer GaS-based two-dimensional electronic and optoelectronic devices.

Combined scanning tunneling microscopy, spectroscopy and local barrier height (LBH) studies show that low-temperature-cleaved optimally-doped Ba(Fe1-xCox)2As2 crystals with x=0.06, with Tc = 22 K, have complicated morphologies. Although the cleavage surface and hence the morphologies are variable, the superconducting gap maps show the same gap widths and nanometer size inhomogeneities irrelevant to the morphology. Based on the spectroscopy and LBH maps, the bright patches and dark stripes in the morphologies are identified as Ba and As dominated surface terminations, respectively. Magnetic impurities, possibly due to cobalt or Fe atoms, are believed to create local in-gap state and in addition suppress the superconducting coherence peaks. This study will clarify the confusion on the cleavage surface terminations of the Fe-based superconductors, and its relation with the electronic structures., Accepted to Nano Letters (5 figures)

Group-IIIA metal-monochalcogenides have attracted increasing interests due to their optoelectronic and spin electronic properties. Achieving the modification of their magnetism is desirable for device applications. In our work, structural, electronic, and magnetic properties of the Fe adsorbed GaSe monolayer are studied systematically using density functional theory (DFT). It is found that there is a strong orbit coupling effect between Fe and the vicinal Ga and Se atoms, resulting in a half-metallicity with a 100% spin polarization. The magnetic moments of the nearest neighbour Ga and Se atoms are −0.004 μB and −0.178 μB, respectively, demonstrating an antiferromagnetic coupling with the adsorbed Fe atom. Meanwhile, the induced majority and minority spin states are inclined to distribute on the Se and Ga atoms separately. The hybridization of Fe-3d, Se-4p, and Ga-4p orbitals is responsible for the induced magnetic moments and spin polarization in the nonmagnetic GaSe monolayer. These investigations shed light on understanding the electronic and magnetic properties of the ferromagnetic/GaSe adsorption system, which offer some references for the design and construction of two-dimensional spin nanostructures.

Inspired by the profound physical connotations and potential application prospects of the valleytronics, we design a two-dimensional (2D) $\mathrm{W}{\mathrm{S}}_{2}/h\ensuremath{-}\mathrm{VN}$ magnetic van der Waals (vdW) heterostructure and study the control of valley degrees of freedom through the first-principles calculations. A considerable spin splitting of 627 meV is obtained at the $K$ valley, accompanied with a strong suppression of that at the ${K}^{\ensuremath{'}}$ valley. An intrinsic large valley splitting of 376 meV is generated in the valence band, which corresponds to an effective Zeeman magnetic field of 2703 T. Besides the valence band, the conduction band of $\mathrm{W}{\mathrm{S}}_{2}$ possesses a remarkable spin splitting also, leading to the possible formation of valley-labeled dark exciton states at the ${K}^{\ensuremath{'}}$ valley. The strengths of spin and valley splitting relying on the interfacial orbital hybridization are further tuned continually by the in-plane strain and interlayer spacing. Maximum spin and valley splitting of 654 and 412 meV are finally achieved, respectively, and the effective Zeeman magnetic field can be enhanced to 2989 T with a \ensuremath{-}3% strain. Time-reversal symmetry breaking and the sizable Berry curvature in the heterostructure lead to a prominent anomalous Hall conductivity at the $K$ and ${K}^{\ensuremath{'}}$ valleys. Based on these finding, a prototype filter device for both the valley and spin is proposed.

Highly repeatable fabrication of compact perovskite films is crucial for large-area perovskite cells (PSCs) in commercial applications. In this work, a vapor-assisted method with the combination of spin-coating and thermal evaporation is employed to fabricate the double-layer PbI2/PbIxBr(2-x) precursor. It is found that surface morphologies of perovskite films could be tailored through tuning the spin-coating speed (the first precursor layer) and chemical compositions (the second precursor layer). The continuous pinhole-free perovskite films are successfully fabricated by double-layer PbI2/PbBr2 precursors. The open-circuit voltages of all the corresponding cells exceed 1.00 V, showing an average value of 1.02 V. The high mean voltage and small variation reveals high repeatability of this method. This work provides a potential method to achieve large-area and high-efficiency PSCs.

This paper proposes a low-carbon location routing problem (LCLRP) model with simultaneous delivery and pick up, time windows, and heterogeneous fleets to reduce the logistics cost and carbon emissions and improve customer satisfaction. The correctness of the model is tested by a simple example of CPLEX (optimization software for mathematical programming). To solve this problem, a hyper-heuristic algorithm is designed based on a secondary exponential smoothing strategy and adaptive receiving mechanism. The algorithm can achieve fast convergence and is highly robust. This case study analyzes the impact of depot distribution and cost, heterogeneous fleets (HF), and customer distribution and time windows on logistics costs, carbon emissions, and customer satisfaction. The experimental results show that the proposed model can reduce logistics costs by 1.72%, carbon emissions by 11.23%, and vehicle travel distance by 9.69%, and show that the proposed model has guiding significance for reducing logistics costs.

In this paper, we consider a variant of the location-routing problem (LRP), namely the the multiobjective regional low-carbon LRP (MORLCLRP). The MORLCLRP seeks to minimize service duration, client waiting time, and total costs, which includes carbon emission costs and total depot, vehicle, and travelling costs with respect to fuel consumption, and considers three practical constraints: simultaneous pickup and delivery, heterogeneous fleet, and hard time windows. We formulated a multiobjective mixed integer programming formulations for the problem under study. Due to the complexity of the proposed problem, a general framework, named the multiobjective hyper-heuristic approach (MOHH), was applied for obtaining Pareto-optimal solutions. Aiming at improving the performance of the proposed approach, four selection strategies and three acceptance criteria were developed as the high-level heuristic (HLH), and three multiobjective evolutionary algorithms (MOEAs) were designed as the low-level heuristics (LLHs). The performance of the proposed approach was tested for a set of different instances and comparative analyses were also conducted against eight domain-tailored MOEAs. The results showed that the proposed algorithm produced a high-quality Pareto set for most instances. Additionally, extensive analyses were also carried out to empirically assess the effects of domain-specific parameters (i.e., fleet composition, client and depot distribution, and zones area) on key performance indicators (i.e., hypervolume, inverted generated distance, and ratio of nondominated individuals). Several management insights are provided by analyzing the Pareto solutions.

Two-dimensional transition-metal dichalcogenides (TMDCs) possess unique electronic and optical properties, which open up a new opportunity for atomically thin optoelectronic devices. Synthesizing large-scale monolayer TMDCs on the SiO

The silicon-based semiconductor industry is approaching its performance limit with the development in the post-Moore era. Along with the introduction of new device configurations, the design of metal quantum structures with semiconductor characteristics provides new alternatives for improving the performance of microelectronic devices. Real-life applications can be realized by opening their bandgaps and achieving gate-controllable semiconducting transport. Therefore, various metal quantum structures have been designed and developed since the end of the previous century. Further, effective control of their transport characteristics has been widely studied. In this paper, we review the research progress of metal quantum structures having different dimensions, including zero-dimensional quantum dots, one-dimensional nanowires/nanotubes, and two-dimensional materials/artificial lattices/superconducting films. Given the above structural systems, we introduce concepts to modify their energy gaps, analyze the realization methods and internal mechanisms of the controllable transport characteristics, and identify the electrical properties and application prospects of materials and structures. Furthermore, based on recent research progress, future research directions are proposed, including the development of the transport and spin correlation characteristics of metal quantum structures and the design of all-metallic channel materials, structures, and devices that can simultaneously transmit charge and spin information with a gate-controllable transport bandgap.

Sustainable development is critical to cold chain logistics, including its economic, environmental, and social effects, especially in road transportation. To simultaneously address these issues, we propose a comprehensive cold-chain-based low-carbon location-routing-problem optimization model to minimize the total logistics costs and client and vehicle waiting time. The first objective comprises the fixed costs of depots to open and vehicles to rent, vehicle renting cost, driver salaries, fuel consumption cost, carbon emission costs, and damage costs of cargos that need to be refrigerated or frozen. The second objective consists of the waiting time of clients and vehicles to improve client satisfaction and the efficiency of the cold chain logistics network. In the proposed problem, we developed a strategy for improving the efficiency of the cold chain logistics network by mixing the types of cargos arranged in one vehicle. Aiming at efficiently solving the proposed model, six well-known multi-objective evolutionary algorithms (MOEAs) were used by combining an efficient framework, and first (FI) and best-improvement (BI) search mechanisms were considered. In the experiments, we examined the effectiveness of six MOEAs inserting the proposed framework and search mechanisms, and the result showed that NSGA-II/FI, SPEA2/FI, and NSGA-II/BI were the top three MOEAs. In the extensive experiments, the results showed that the delivery strategy, depot cost, depot capacity, crowding distance, and traveling speed have significant effects on the Pareto front, fuel consumption, carbon emission, vehicle and client waiting times, traveling distance, and traveling time.

This paper proposed a novel approach for a practical version of the cold chain, namely location-routing problem-based low-carbon cold chain (LRPLCCC). In the proposed bi-objective model, the first objective is the total logistics cost, including the fixed costs of the opened depots and leased vehicles, as well as the cost of fuel consumption and carbon emissions, and the second is to minimize the amount of quality degradation that aims at improving clients’ satisfaction and maintain product freshness. The cargos of clients are classified into three types: general, refrigerated, and frozen cargos. Since the presented problem is NP-hard, a novel multi-objective hyperheuristic (MOHH) was proposed to obtain the Pareto solutions. In this framework, three selection strategies were developed to improve the performance of MOHH, that is, random simple, choice function, and FRR-MAB (fitness rate rank based multi-armed bandit), and three acceptance criteria using the decomposition approaches in MOEA/D were also developed, namely penalty-based boundary intersection, Tchebycheff, and modified Tchebycheff approaches. Extensive experiments were provided to verify the efficiency of the proposed algorithms and assessed the effects of algorithm parameters on the Pareto front. The results showed that the efficiency of the proposed algorithm outperforms several existing well-known multi-objective evolutionary algorithms (MOEA).