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Bipolar magnetic semiconductor and spin Seebeck effects in 2H-NbSe2 monolayers.

The eigenstate distribution of the HOMO and LUMO in the perylene-based device.

The perfect spin filtering effect and high magnetoresistance for the magnetic tunnel junction Au/GdI2/Au are reported.

The spin-dependent transmission path in the VSi2P4/FeCl2 heterostructure.

A practical route to achieve the flexible and effective regulation of magnetic, electronic, and optical properties of 2D multifunctional TM2@g-C4N3 monolayers is established based on the transition metal permutation and strain engineering strategy.

How to effectively tune 2D electronic and magnetic properties is key to developing novel spintronic materials and devices. Although the strain induced metal-to-half-metal electronic phase transition (EPT) has been studied in 2H NbSe

Based on first-principles calculations in combination with the Boltzmann transport theory, we investigate the effects of onsite Coulomb interaction and strain on the lattice thermal conductivity of the KAgSe monolayer, a recently discovered 2D thermoelectric system with a low lattice thermal conductivity when the onsite Coulomb interaction was not considered (X. Zhang, C. Liu, Y. Tao, Y. Li, Y. Guo, Y. Chen, X. C. Zeng and J. Wang

Nanostructured silicon carbide (SiC) materials are expected to have bright prospect in application as high-performance electrode materials with excellent charge–discharge cycling stability. However, the exploration of SiC-based micro-supercapacitors (MSCs) still remains a grand challenge seriously hampered by low areal capacities and complicated multistep production process. Herein, we report that rationally designed SiC/C nanocomposite with hierarchical porous structure and improved electrical conductivity has been realized by a facile and rapid carbothermic reduction using silica sol and sucrose as silicon and carbon source. The amorphous carbon between SiC nanoparticles (NPs) contributes to enlarged surface areas and excellent conductivity, not only ensuring intimate contact between the electrolyte and the electrode but also providing an effective ion highway for electrolyte ions. As a result, MSCs based on SiC/C nanocomposite (Si/C mass ratio of 1:1.5) demonstrate an optimal specific areal capacitance of 11.8 mF cm−2 at 2 mV s−1, outstanding flexibility (104.5% retention of initial capacitance at 180° bending), and superior integration. Most notably, the capacitance remains at 97.3% of the initial value after 50000 charging/discharging cycles, superior to that of most advanced SiC-based MSCs ever reported. This work demonstrates an effective design for hierarchical porous SiC/C nanocomposite for energy storage, which gives significant inspirations on the exploration of high-performance SiC-based MSCs.

Although 2D phosphorene has exhibited promising applications in electronic and optoelectronic devices with high carrier mobility and high on/off ratio, the nonmagnetism in pristine phosphorene hind...

Reconfigurable magnetic tunnel diodes have recently been proposed as a promising approach to decrease the base collector leakage currents. However, conventional bulk interfaces usually suffer from strong Fermi level pinning, making it difficult to miniaturize spintronic devices. Fortunately, 2D van der Waals (vdW) systems with ultra-clean interfaces and without dangling bonds can solve this problem. Inspired by the recently discovered novel electronic states of type-II spin gapless semiconductor in 2D VSi

The transition metal ions are often used to enhance the photoluminescent effciency in many compounds, which are always received as scintillators, optical sensors and memories, laser media, optoelec...

Boron and its compounds have attracted much attention due to their interesting and complex structures. In particular, boron-rich compounds containing icosahedral structures have excellent properties, such as low density, high hardness, high melting point and low wear coefficient., This work was supported by the Fostering Program of Major Research Plan of the National Natural Science Foundation of China (91963115), the National Key R&D Program of China (2018YFA0703400), the National Natural Science Foundation of China (51732010), and the PhD Foundation by Yanshan University (B970). Bergara A acknowledges financial support from the Spanish Ministry of Economy and Competitiveness (FIS2016-76617-P) and the Department of Education, Universities and Research of the Basque Government and the University of the Basque Country (IT756-13).

2D intrinsic ferromagnets with high spin polarization and high Curie temperature are rare and very important for developing novel nanoscale spintronic materials and devices. In this letter, by usin...

Different from two-dimensional (2D) transition-metal dichalcogenides, 2D transition-metal trichalcogenides with a quasi-one-dimensional chain offer additional advantages in electronics and optoelec...

Over 50 million adults in China suffer from angina pectoris, which are often treated with traditional Chinese medicine injections (TCMIs). However, the efficacies of TCMIs and conventional drugs as determined by randomized controlled trials (RCTs) were not rigorously compared with one another by network meta-analysis (NMA). This PRISMA-compliant NMA aimed to compare the efficacy and assess the evidence strengths of 24 TCMIs in treating adults with angina pectoris of RCTs.Following the protocol (PROSPERO registration number CRD42018117720), the RCTs that compared any TCMI with another TCMI or conventional drug on outcome measures including symptomatic and electrocardiography improvements were included. The quality of included RCTs was assessed with the Cochrane's risk of bias 2 tool. Frequentist statistical analyses were performed, including NMA, pairwise meta-analysis (PMA), subgroup analysis, sensitivity analysis, meta-regression, and publication bias analysis. The certainty of evidence was assessed with the GRADE approach.Totally, 556 eligible RCTs with 57015 participants were identified while the quality of all but five included RCTs was poor. The significant efficacy estimates and insignificant heterogeneity assessment from PMA and NMA indicated that nearly all TCMIs were more efficacious than conventional treatments for angina pectoris. Adequate subgroup and sensitivity analyses found the robust and consistent results. However, the evidence strengths of meta-analyses were assessed as very low to low due to the high risk of RCTs. The comprehensive efficacy estimates suggested that 4 TCMIs (HH, Honghua injection; HHH, Honghua Huangsesu injection; GLP, Gualoupi injection; and SM, Shenmai injection) was the best anti-anginal drugs for adults with angina pectoris.TCMIs appear to be efficacious for angina pectoris, although evidence evaluation of high-quality RCTs of TCMIs would be necessary. In particular, randomization and blinding procedures of the RCTs should be explicated to meet the CONSORT requirements.

Ultralow lattice thermal conductivity is crucial for achieving a high thermoelectric figure of merit for thermoelectric applications. In this work, using first-principles calculations and the phonon Boltzmann transport theory, we investigate the phonon thermal transport properties of 2D KCuSe. Our calculations indicate that the strong acoustic-optical coupling, the low-lying acoustic phonon modes and the strong lattice anharmonic effect with a large Grüneisen parameter and phase space volume result in an ultralow lattice thermal conductivity of 0.021 W m

Search for new high-temperature superconductors and insight into their superconducting mechanism are of fundamental importance in condensed matter physics. The discovery of near-room temperature superconductivity at more than a million atmospheres ushers in a new era for superconductors. However, the critical task of identifying materials with comparable superconductivity at near or ambient pressure remains. Carbon materials can always lead to intriguing surprises due to their structural diversity and electronic adjustability. Insulating diamond upon doping or external stimuli has achieved superconducting state. Thus, it still has a great opportunity to find superconducting ones with higher transition temperature (Tc). Here, we report an intrinsic superconducting graphite-diamond hybrid through first-principles calculations, whose atomic-resolution structural characteristics have been experimentally determined recently. The predicted Tc is approximated at 39 K at ambient pressure, and strain energizing can further boost Tc to 42 K. The strong electron-phonon coupling associated with the out-of-plane vibration of carbon atoms at the junction plays a dominant role in the superconducting transition. Our work demonstrates the great potential of such carbon materials as high-Tc superconductors, which will definitely attract extensive research., 11 pages, 3 figures

For anisotropic magneto-resistance (AMR) effect, its value synergistically depends on the magnitudes of magneto-resistance (MR) and magneto-crystalline anisotropy energy (MAE) simultaneously. In a magnetic material, the concurrence of gigantic AMR and MR signals is rather difficult due to weak spin-lattice coupling and small MAE. Here we report the considerable magneto-transport effect in layered A-type antiferromagnetic (AFM) NaCrTe2 by realigning the spin configurations. By applying H, the antiparallel spins of adjacent layers are flipped to ferromagnetic (FM) coupling either Ising-type along c-axis or XY-type within ab-plane. Theoretical calculations reveal that the energy bandgap narrows from 0.39 eV to 0.11 eV, accompanying a transition from semiconductor (high-R state) and half-semiconductor (low-R state), respectively. Thus, gigantic negative MR ratio of -90% is obtained at 10 K. More importantly, the decrement of R along H//c is far quicker than that of H//ab because the MAE of Ising-FM state is 1017 {\mu}eV/Cr3+ lower than that of XY-FM. The distinct trends result in the AMR ratio of 732% at 10 K, which is the record value to our best knowledge. These findings unravel the intrinsic origin of magneto in NaCrTe2 and will stimulate us to exploring the H-sensitive transport property in more AFM materials., Comment: 16 pages, 4 figures

Atomically thin 2D magnetic materials have attracted increasing attention due to their promising applications in spintronic devices. Although more and more 2D intrinsic ferromagnetic materials have been theoretically predicted, few of them have been experimentally synthesized due to the thermal fluctuations at finite temperatures, and unfortunately, they have either low Curie temperatures or low spin polarization, which is not beneficial to spintronic applications. Very recently, the predicted 2D ferromagnetic half-metal of 1T-FeCl2 with 100% spin polarization, high Curie temperature and large magnetic anisotropic energy has been grown by molecular-beam epitaxy. In this work, we propose a vertical 1T-FeCl2-based van der Waals junction of 1T-FeCl2/2H-MoS2/1T-FeCl2 with the electrode of 1T-MoS2, which has the advantage of clean interfaces compared to the lateral 2D heterostructures. Our calculated spin transport properties based on the first-principles and the nonequilibrium Green's function method indicate the excellent spin filtering effect and negative differential resistance effect as well as the high tunnel magnetoresistance ratio (up to 6300%). The physical mechanisms are discussed in terms of the spin-resolved junction density of states and the energy- and momentum-resolved spin-polarized transmission spectra. The standing wave pattern and the quantum-well resonances are observed in the junction. These results suggest the potential 2D spintronic applications for the experimentally synthesized atomically thin 1T-FeCl2, and will stimulate experimental and theoretical studies on van der Waals magnetic tunnel junctions.

Background Pulmonary lymphoepithelioma-like carcinoma (PLELC) is a rare subtype of non-small cell lung cancer associated with Epstein-bar virus (EBV) infection. Epithelioid granuloma (EG) has been more scarcely reported and frequently misdiagnosed. Methods Data were collected from January 2013 to October 2019. Of 227 patients diagnosed as having PLELC, 22 patients had EG. We analyzed their clinical features, pathological characteristics and treatment and a comparison between PLELC patients complicated with or without EG was made. Results Twenty-two patients had complicated with EG (9.6%). The median age was 50 years (38–67 years). There were more females than males (1.4:1). Most patients were at early stage (68.2%) with nonspecific manifestations and lack of Rich-Lewis phenomenon. Compared with the 205 patients complicated without EG, there were no significant difference among age (t=0.938, P=0.349), gender (χ2=0.898, P=0.343), initial symptoms (χ2=2.684, P=0.443), smoking status (χ2=0.210, P=0.647), diameter of tumor(t=0.993, P=0.332) and performance status (H=0.971, P=0.615). EG was often located inside or adjacent to the tumor (71.4%). Specific staining was negative, whereas in situ hybridization staining of EBV-encoded RNA was consistently positive. Most patients complicated with EG received multimodality therapy including surgery, neo-adjuvant/adjuvant chemotherapy or palliative chemotherapy and none of them received anti-TB therapy. Compared with the 205 patients complicated without EG, there were no significant difference among tumor stage, DFS (median, not reached, P=0.914), PFS (median, 12.3 months, P=0.848), OS (median, not reached, P=0.737) and treatment including anti-tumor therapy and anti-TB therapy. During follow-up duration for 14.6 months (range, 2.1–94.7 months), none of the patients had occurrence, progression or relapse of tuberculosis, regardless whether anti-tuberculosis therapy was initiated. Conclusions PLELC complicated with EG was lack of Rich-Lewis phenomenon and specific clinical characteristics compared with those without EG. EG might be caused by immunological hypersensitivity to tumor cells or EBV infection but not pulmonary tuberculosis. PLELC complicated with EG could be treated with chemotherapy and surgery. However, anti-tuberculosis therapy was unnecessary.

Strengths of nanograined (ng) and nanotwinned (nt) metals increase with decreasing grain size and twin thickness, respectively, until reaching a critical value, below which strength decreases. This behavior is known as the reverse Hall–Petch effect (RHPE), which has also been observed in nanograined cubic boron nitride (cBN) and diamond. Surprisingly, however, hardness of nt-cBN and nt-diamond increases continuously with decreasing twin thickness down to several nanometers, suggesting the absence of RHPE in these covalent materials. The mechanism responsible for such a behavior remains controversial. Here we investigate the strengthening mechanisms in ng- and nt-diamond using molecular dynamics and first-principles calculations. For ng-diamond, the competition between shuffle-set dislocation (SSD) and grain boundary atom motions gives rise to RHPE. For nt-diamond, SSDs remain dominant but their slips along twin boundaries energetically show no advantage over those along other slip planes. Twin domains are locked and mechanically stable, resisting SSD propagation and inhibiting RHPE. These findings provide new insights into the hardening mechanism of nanotwinned covalent materials.

Cubic boron nitride (cBN) exhibits superior hardness and strength as compared with other ceramics that are commonly used as abrasives and cutting tools. The recently synthesized polycrystalline cBN bulk material with ultrafine nanotwin substructures possesses a remarkable combination of high hardness, fracture toughness, and thermal stability. The twin substructure has been demonstrated to exert dislocation-blocking effect similar to grain boundary, leading to strengthening of materials. So far, the synthesis of cBN nanoparticles with ultrafine nanotwin substructures has not yet been realized. Herein, we report on the synthesis of cBN nanoparticles from onion-like boron nitride (oBN) under high pressure and high temperature. Multiple characterization methods, including X-ray diffraction, Raman spectroscopy, and high-resolution transmission electron microscopy, revealed that the as-prepared cBN nanoparticles contained high-density nanotwin substructures. The use of the highly wrinkled oBN precursor and well-designed synthetic method were the key to obtain these unique ultrafine nanotwinned cBN nanoparticles.

Based on the first-principle method, the effects of carbon dopants on AlP are studied. Our investigations indicate carbons substituting aluminum (CAl) or phosphorus (CP) cannot induce the AlP to be magnetic system. The AlP with CAl defects shows n-type metallic characteristic. As the carbons forming the interstitial doped configurations (Cint), a few percent of Cint could induce the AlP to be a half-metallic ferromagnet, and the half-metallic gaps could reach 0.45∼0.48 eV. Mean field theory predicts the Curie temperature for Cint doped configurations would be above room temperature. Formation energies indicate that Cint, CAl and CP defects could be realized experimentally. Positive pair binding energies indicate that carbon would form homogenous distribution in AlP host. This research suggests carbon is a promising dopant, and could be utilized to functionalize the AlP's properties for versatile applications.

Inspired by the recent prediction of high carrier mobility and moderate energy gap in the metal-shrouded 2D semiconductor Tl2O [Ma, Y.; et al. J. Am. Chem. Soc. 2017, 139, 11694–11697], we present ...

Background Pulmonary lymphoepithelioma-like carcinoma (PLELC) is a rare subtype of lung cancer that is less reported and not well-understood. Materials and Methods We investigated the clinical features of 85 patients with PLELC to determine the prognostic factors. Results PLELC preferentially affected the young (71.8%) and nonsmokers (72.9%), without a significant difference in gender. Most (50.6%) patients were at the early stage with opportunity for operation, and patients at advanced stages mainly received multimodality treatment. The median follow-up duration was 17 months (range, 1-39 months) for the whole group, and the 3-year overall survival rate for patients in the early stage was 100%, whereas the 1-year and 2-year overall survival rate for patients in the advanced stage were 93% and 77%, respectively. The tumor stages (P = .031), distant lymph node metastasis (P = .035) and performance status (P = .008) were associated with progression-free survival in the univariate analysis, whereas performance status was an independent prognostic factor in the multivariate analysis (P = .016). The median progression-free survival in the paclitaxel plus platinum (12 months) group and gemcitabine plus platinum (10 months) group were significantly longer than that in the pemetrexed plus platinum (5 months) group (P = .001). Conclusion PLELC had a better prognosis compared with other types of non–small-cell lung cancer and was sensitive to radiotherapy and chemotherapy. Gemcitabine plus platinum and paclitaxel plus platinum should be used as first-line treatment of PLELC, whereas the second-line treatment, if necessary, was always decided by the managing oncologist. The tumor stages and performance status were predictive in the prognosis of patients with PLELC.

Boron carbide is an extremely hard material extensively used in the industry. In this study, carbon-coated B4C nanoparticles were synthesized through a one-step synthesis method using high-temperature firing cheap and readily available raw materials, namely, boric acid and sucrose. X-ray diffraction and Raman spectra analysis indicated the formation of B4C, and high-resolution transmission electron spectroscopy revealed that the carbon-coated B4C nanoparticles exhibited regular B4C-C core-hell structure with an average particle diameter of around 100 nm. This method is simple and time-saving, and can be adopted for the large-scale production of the core-shell nanoparticle. Directly using these core-shell structural nanoparticles as precursor, high-performance B4C/C ceramics with hardness reaching 34 GPa, fracture toughness reaching 3.3 MPa m1/2 were synthesized. This study has important implications in developing high-performance B4C ceramics.

The observation of fracture behaviors in perfect and twinned B