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This investigation aimed to study the individual and synergic impacts of SiC and TiN additives on the sinterability and microstructure of TiB2-based ceramics. The hot-pressing method at 2000 °C was implemented to fabricate the samples. All three samples reached their near full densities thanks to the beneficial role of the incorporated phases. In terms of the TiB2–SiC composite, the in-situ SiO2 was produced over the sintering process because of a chemical reaction between TiO2 oxide and SiC reinforcement. On the other hand, the X-ray diffraction (XRD) pattern, along with the microstructural observations, revealed the in-situ formation of hexagonal BN (hBN) in the TiB2–TiN system. Moreover, the dissolution of boron into the TiN additive led to the formation of a solid solution, and consequently, a strong diffusion bonding was achieved. Although no hBN compound was identified in the ternary system of TiB2–SiC–TiN, the results confirmed the generation of TiC and TiC0·3N0.7 ingredients during the hot pressing.

The effects of concentration and an oriented external electric field on the transformations of hydrogen-bonded structures of trimesic acid (TMA) and terephthalic acid (TPA) have been investigated at a liquid–solid interface by scanning tunneling microscopy (STM). The triangular periodic TMA framework can be transformed into a flower-like structure by changing the STM sample bias sign in situ. Networks of TMA and TPA are porous at a negative substrate bias, but typically change to relatively compact forms when the polarity of the applied bias is reversed. This change is reversible if the applied bias is reversed. The effects have potentials to locally control the capture and release of analytes in host-guest systems and the 2D morphology in multicomponent layers.

The purpose of this paper was to investigate the influence of WC as a sintering aid on the sinterability and mechanical characteristics of TiC. For this purpose, two specimens, namely TiC-5 vol% WC and monolithic TiC, were manufactured using the hot-pressing route at 2000 °C for 2 h under 50 MPa. The addition of WC uplifted the sintering behavior of TiC. The XRD and microscopical evaluations revealed the precipitation of graphitized carbon in the TiC matrix. The results also manifested the complete dissolution of WC in the matrix, forming the (Ti,W)C solid solution. The addition of WC improved the Vickers hardness and flexural strength of TiC by ~12% and ~20%, respectively. Grain size, remaining porosity, and composition of the matrix were identified as the essential factors in boosting the mechanical properties of the TiC-WC specimen compared to the monolithic TiC.

Two-dimensional binary hydrogen-bonded organic frameworks constructed from 1,3,5-benzenetricarboxylic acid (TMA) and 4,4'-biphenyldicarboxylic acid (BDA) on highly oriented pyrolytic graphite (HOPG) were investigated by scanning tunneling microscopy (STM) in heptanoic acid and octanoic acid solvents. High-resolution STM observations demonstrated that various assemblies of hydrogen-bonded networks are strongly dependent on the nature of the solvent. Well-ordered porous rectangular flowerlike networks were revealed at the heptanoic acid/HOPG interface, whereas two different coexisting densely packed guest-host BDA/TMA structures were observed at the octanoic acid/HOPG interface. It is suggested that the stabilization of the binary networks is possibly associated with the solvent chain length, and longer-chain solvents favored the formation of porous polymorphic networks.

To evaluate the efficacy of Liangxue Guyuan decoction ( LGD) on radiation-induced intestinal injury in rats, and the possible underlying mechanism of action.A total of 255 male Sprague-Dawley rats were used. 15 rats were assigned to the control group and the remaining 240 rats were exposed to a 60Co source at a dose of 11 Gy. Irradiated rats were randomly divided into model, dexamethasone (DXM), low-dose LGD (LGDl), and high-dose LGD (LGDh) groups and treated for 11 d. The survival rate, weight of body, intestinal pathology and the expression of toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), and nuclear factor-kappa B (NF-κB) were recorded.Radiation reduced the survival rate and weight of rats, destroyed the intestinal structure, induced an inflammatory reaction, and increased both protein and mRNA expression of TLR4, MyD88, and NF-κB in ileum. However, LGDh increased the survival rate, inhibited weight loss, alleviated inflammation and improve the expression of TLR4 pathway.LGD increased the survival rate and inhibit weight loss of irradiated rats, and reduced inflammation and intestinal injury. The underlying mechanism may involve regulation of the TLR4/MyD88/NF-κB pathway.

To study the anti-tumor effects of the extracts from Huangqi (Radix Astragali Mongolici) and Ezhu (Rhizoma Curcumae Phaeocaulis) on the growth of Lewis lung carcinoma (LLC) in a xenograft mouse model and to investigate the possible underlying mechanism.LLC tumor-bearing C57BL/6 mice were treated with normal saline, cisplatin (2 mg/kg intraperitoneally every other day), or Huangqi (Radix Astragali Mongolici) and Ezhu (Rhizoma Curcumae Phaeocaulis) (1∶1, 2∶1, or 3∶1 ratio; 5 , 8 , or 11 g/kg crude drug intragastrically every day) for 15 d. Body weights and tumor volumes were measured every other day. Tumors were excised on day 15 and analyzed. Tumor microvessel density (MVD) was assessed by immunohistochemical staining of CD34; and expression of vascular endothelial cell growth factor (VEGF), the mitogen-activated protein kinases p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinases 1 and 2 (ERK1/2), and Jun N-terminal kinase (JNK) and their phosphorylated forms were assessed by Western blotting.Treatment with cisplatin caused a significant loss of body weight compared with controls, whereas Huangqi (Radix Astragali Mongolici) and Ezhu (Rhizoma Curcumae Phaeocaulis) extract combinations had no effect. Extracts from Huangqi (Radix Astragali Mongolici) and Ezhu (Rhizoma Curcumae Phaeocaulis) significantly decreased tumor weight and tumor MVD compared with controls, and at the 3∶1 treatment group had similar efficacy to cisplatin in reducing MVD. Tumors from Huangqi (Radix Astragali Mongolici) and Ezhu (Rhizoma Curcumae Phaeocaulis) treatments also showed decreased p38 MAPK, p-p38 MAPK, ERK1/2, p-ERK1/2, JNK, and p-JNK expression compared with the control group (all P0.01). VEGF protein expression was significantly reduced in the 2∶1 and 3∶1 treatment groups compared with the control group (P0.01).Extracts from Huangqi (Radix Astragali Mongolici) and Ezhu (Rhizoma Curcumae Phaeocaulis) hindered LLC growth in the xenograft mouse model, possibly via inhibition of the MAPK signaling pathway, VEGF production, and tumor angiogenesis.

To investigate the effect of optimal combination (E) of Huangqi (Radix Astragali Mongolici) and Ezhu (Rhizoma Curcumae Phaeocaulis) on proliferation and apoptosis of A549 lung cancer cells and the possible mechanism underpinning the action.A uniform design method was used to optimize the E of Huangqi (Radix Astragali Mongolici) and Ezhu (Rhizoma Curcumae Phaeocaulis) in A549 lung cancer cells. MTS assay was applied to analyze the effect of the component formula of Huangqi (Radix Astragali Mongolici) and Ezhu (Rhizoma Curcumae Phaeocaulis) on A549 cells viability in various uniform design groups. A549 cells with exponential growth in routine culture were exposed to CoCl2 (200 μmol/L) to mimic hypoxic conditions. Group 0 was treated with RPMI-1640, the group CoCl2 was treated with CoCl2 (200 μmol/L), the group DDP + CoCl2 was treated with 4 mg/L Cisplatin injection (DDP) + CoCl2 (200 μmol/L), and the drug group was treated with various dose of E (0.5E, 1E, 2E) + CoCl2 (200 μmol/L). All groups were cultured for 24 h. Cell apoptosis was measured by Annexin V-FITC/propidium iodide double staining and flow cytometry. Western blot assay and quantitative real-time polymerase chain reaction (qRT-PCR) were employed to detect the protein and mRNA expression of B-celllymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax) and cysteinyl aspartate specific proteinase-3 (caspase-3).The E obtained by the uniform design was comprise of 200 mg/L Astragalus polysaccharide (X1) and 32 mg/L Curcumin (X3). Group DDP+CoCl2, group 1E + CoCl2 and group 2E + CoCl2 promoted the apoptosis of A549 cells (P0.05). Group 1E + CoCl2 and group 2E + CoCl2 had no statistically significant differences compared with the group DDP + CoCl2 (P0.05). Compared with group 0, various doses of E + CoCl2 could up-regulate the expression of Bax and caspase-3 and down-regulate the expression of Bcl-2 at protein and mRNA levels (P0.05).Astragalus polysaccharide and Curcumin was the optimal combination of Huangqi (Radix Astragali Mongolici) and Ezhu (Rhizoma Curcumae Phaeocaulis). E promoted the apoptosis of A549 cells. Combination of Astragalus polysaccharide and Curcumin increased the expression of Bax and caspase-3, and decreased the expression of Bcl-2 to initiate apoptosis in A549 cells under chemical-induced hypoxia.

Two kinds of variable binary supramolecular structures constructed by 1,3,5-benzenetricarboxylic acid (TMA) and terephthalic acid (TPA) on a highly oriented pyrolytic graphite (HOPG) were investigated by scanning tunneling microscopy (STM). Two different solvents (heptanoic acid and nonanoic acid) were utilized to affect the self-assembling structures of TMA and TPA at the liquid/HOPG interfaces. High-resolution STM measurement revealed that the functional networks of TMA/TPA are proposed from the hydrogen-bonding under different solvents environment, and the functionalized flower network could recognize three AgNO 3 molecules. These results could be helpful for designing functionalized molecular networks by multi-component self-assembling strategy.

Semiconducting monolayer (ML) blue phosphorene (BlueP) shares similar stability with ML black phosphorene (BP), and it has recently been grown on an Au surface. Potential ML BlueP devices often require direct contact with metal to enable the injection of carriers. Using ab initio electronic structure calculations and quantum transport simulations, for the first time, we perform a systematic study of the interfacial properties of ML BlueP in contact with metals spanning a wide work function range in a field effect transistor (FET) configuration. ML BlueP has undergone metallization owing to strong interaction with five metals. There is a strong Fermi level pinning (FLP) in the ML BlueP FETs due to the metal-induced gap states (MIGS) with a pinning factor of 0.42. ML BlueP forms n-type Schottky contact with Sc, Ag, and Pt electrodes with electron Schottky barrier heights (SBHs) of 0.22, 0.22, and 0.80 eV, respectively, and p-type Schottky contact with Au and Pd electrodes with hole SBHs of 0.61 and 0.79 eV, respectively. The MIGS are eliminated by inserting graphene between ML BlueP and the metal electrode, accompanied by a transition from a strong FLP to a weak FLP. Our study not only provides insight into the ML BlueP–metal interfaces, but also helps in the design of ML BlueP devices.

The heavy ion fusion–evaporation reaction study for the high-spin spectroscopy of 75As has been performed via the reaction channel 70Zn(9Be, 1p3n)75As at a beam energy of 42 MeV. The collective structure especially a dipole band in 75As is established for the first time. The properties of this dipole band are investigated in terms of the self-consistent tilted axis cranking covariant density functional theory. Based on the theoretical description and the examination of the angular momentum components, this dipole band can be interpreted as a novel stapler band, where the valence neutrons in ( 1 g 9 / 2 ) orbital rather than the collective core are responsible for the closing of the stapler of angular momentum.

Astragalus membranaceus and Salvia miltiorrhiza (AM/SM) are well used in Traditional Chinese Medicines (TCM) for nourishing Qi and activating blood circulation method. From TCM theory, the pathogenesis of acute lung injury (ALI) was determined as Qi deficiency and blood stagnation. In this study, we are aiming to investigate the protective and therapeutic effects of AM/SM on a rat model of lipopolysaccharide- (LPS-) induced ALI in rats and to elucidate potential molecular mechanisms. ALI was induced by intratracheal instillation of LPS (5 mg/kg) in Sprague–Dawley rats. SM/AM was given orally before and after LPS administration. Results demonstrated that AM/SM attenuated lung histopathological changes induced by LPS, decreased wet/dry weight ratios and protein concentrations, and inhibited the production of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in BALF. Moreover, AM/SM significantly downregulated protein and mRNA expression of toll-like receptors 4 (TLR-4), interleukin-1 receptor-associated kinase-1 (IRAK-1), and nuclear factor-kappa B (NF-κB/p65). These findings suggest that AM/SM showed protective and therapeutic effects in LPS-induced ALI rat through modulating TLR-4 signaling pathways. Nourishing Qi and activating blood circulation may be a beneficial treatment for ALI.

We have investigated the electronic properties of 1-, 2-, and 3-layer graphene upon surface adsorption of halogen molecules by means of density functional calculations. The most stable adsorption site is parallel to the graphene surface with the diatomic atoms centered over adjacent carbon rings. Bader analysis shows a large charge transfer between F2 and graphene, which significantly extends the fluorine bond length, while only small amounts of charge are transferred to Cl2, Br2, and I2. Adsorbed halogens alter the electronic properties of graphene by pushing the Fermi level down and bringing forth an accessible impurity band that can be utilized to alter the material properties. Moreover, molecule–surface interactions introduce a bandgap at the K-point between 3 and 330 meV, depending upon the particular graphene-halogen system. When adsorbed on 1-layer graphene, halogen molecules typically open a small bandgap; however, they induce a notably larger bandgap on the 2-layer AB-stacked and 3-layer ABC-stac...

We have investigated the effect of uniform plane strain on the electronic properties of monolayer 1T-TiS2 using first-principles calculations. In the absence of strain, we find monolayer TiS2 is a semimetal, with a small overlap of the valence band maximum and the conduction band minimum. The band overlap increases under compression; however under tensile, monolayer 1T-TiS2 experiences a transition from a semimetal to a semiconductor as a band gap emerges. Moreover, the electronic properties change from an indirect to a direct band gap upon application of greater tensile strain. Thus one can modulate the properties of monolayer TiS2 by applying the appropriate strain, thereby providing a route towards control in optoelectronic devices.

We present a theoretical investigation on the electronic properties and formation energetics of pnictogen substitution into a graphene monovacancy. Our work elucidates the fundamental interactions that occur between the dopant and graphene, which ultimately dictate the observed behavior of the material. We find a linear trend for the energy of formation proceeding down group 15 of the periodic table. Further, we observe the formation of a protrusion at the monovacancy site, which is particularly conspicuous for larger pnictogens. This blistering can be attributed to charge transfer between the substituted heteroatom and the bordering carbon atoms of the monovacancy. Reorganization of the defect site of graphene becomes more pronounced for the latter pnictogens antimony and bismuth. An interaction regime emerges among this group, whereby nitrogen and phosphorus chemisorb strongly to the vacancy site, arsenic weakly chemisorbs, while antimony and bismuth physisorb to the surface. These interactions introduc...

It is well known that there is spin-filter efficiency (SFE) of a linear carbon atomic chain. In this article, we examine the quantum transport calculations of a linear carbon atomic chain connected to two half-planar graphene electrodes by using the first-principle method and reveal for the first time that sign of the SFE of such carbon atomic chain is changeable with the bias. This makes the carbon atomic chains attractive to potential application of spintronics.

We present a search for the production of neutral Higgs bosons decaying into τ + τ − pairs in p p ¯ collisions at a center-of-mass energy of 1.96 TeV. The data, corresponding to an integrated luminosity of 5.4 fb−1, were collected by the D0 experiment at the Fermilab Tevatron Collider. We set upper limits at the 95% C.L. on the product of production cross section and branching ratio for a scalar resonance decaying into τ + τ − pairs, and we interpret these limits as limits on the production of Higgs bosons in the minimal supersymmetric standard model (MSSM) and as constraints in the MSSM parameter space.

We present a measurement of the a production cross section sigma((u) over bar) in p (p) over bar collisions at root s = 1.96 TeV using 5.4 fb(-1) of integrated luminosity collected with the D0 detector. We consider final states with at least two jets and two leptons (ee, e mu, mu mu), and events with one jet for the e mu final state as well. The measured cross section is sigma((u) over bar) = 7.36(-0.79)(+0.90)(stat + syst) pb. This result combined with the cross section measurement in the lepton + jets final state yields sigma((u) over bar) = 7.56(-0.56)(+0.63)(stat + syst) pb, which agrees with the standard model expectation. The relative precision of 8% of this measurement is comparable to the precision of the latest theoretical calculations. (C) 2011 Elsevier B.V. All rights reserved.

Sign-changeable spin-filter efficiency is predicted in both the ferromagnetic and antiferromagnetic configurations of a zigzag graphene nanoribbon bridging two half-planar graphene electrodes from ab initio quantum transport calculations. By changing edge spin-polarization configuration, we obtain giant room-temperature magnetoresistance, which is one order of magnitude larger than the maximum experimental results.

We investigate the transport properties of few-nm-long single-walled carbon nanotube (SWCNT) p-n junctions for the first time by using ab initio quantum transport calculations. Unlike the previously reported few-μm-long SWCNT p-n junctions, which rectify positively, all the investigated ultrashort SWCNT p-n junctions show negative rectification effect, accompanied by negative differential resistance.

We present a new measurement of the WZ -> lvll (l = e, mu) cross section and limits on anomalous triple gauge couplings. Using 4.1 fb(-1) of integrated luminosity of p (p) over bar collisions at root s = 1.96 TeV, we observe 34 WZ candidate events with an estimated background of 6.0 +/- 0.4 events. We measure the WZ production cross section to be 3.89(-0.90)(+1.07) pb, in good agreement with the standard model prediction. We find no evidence for anomalous WWZ couplings and set 95% C.L. limits on the coupling parameters, -0.077 < lambda(z) < 0.093 and -0.029 < Delta kappa(z) < 0.080 in the HISZ parameterization for a Lambda = 2 TeV form factor scale. These are the best limits to date obtained from the direct measurement of the WWZ vertex.

We propose a novel single-molecule organic field effect transistor (FET) fabricated via covalent functionalization of an individual metallic single-walled carbon nanotube (SWCNT). The transfer characteristic of this FET is calculated by using ab initio quantum transport calculations. Because of the significantly reduced screening effect of the quasi-one-dimensional electrode and seamless connection between the electrode and scattering region, the optimized device shows an excellent overall performance over the experimental single-molecule organic field effect transistors. This renders functionalized metallic SWCNTs a promising candidate for a high-performance single-molecule organic field effect transistor.

The high-spin states in 86Sr have been investigated by using in-beam $ \gamma$ -ray spectroscopy with the 82Se(9Be, 5n)86Sr reaction at a beam energy of 53 MeV. The level scheme of 86Sr has been extended considerably, four decay sequences have been established. The observed level schemes are compared with shell-model calculations using the recently developed residual interaction “jun45”, and a good agreement is shown.

The excited states in ${}^{107}$Ag were populated through the heavy-ion fusion evaporation reaction ${}^{100}$Mo (${}^{11}$B, 4$n$) ${}^{107}$Ag at a beam energy of 46 MeV. Lifetimes of high-spin states in ${}^{107}$Ag have been measured through the Doppler shift attenuation method. The deduced $B(M1)$ values, gradually decreasing with increasing spin, clearly demonstrate that both the yrast positive-parity band and the yrast negative-parity band in ${}^{107}$Ag are magnetic rotation bands. Furthermore, experimental deduced $B(M1)$ values for the yrast positive-parity band are compared with the predictions of the particle rotor model. The approximate agreement between theoretical calculations and experimental results further confirms the mechanism of magnetic rotation for the yrast positive-parity band. In addition, a systematic investigation shows the evolution of the magnetic rotation mechanism in the $A\ensuremath{\approx}110$ mass region.

Opening a sizable band gap without degrading its high carrier mobility is as vital for silicene as for graphene to its application as a high-performance field effect transistor (FET). Our density functional theory calculations predict that a band gap is opened in silicene by single-side adsorption of alkali atom as a result of sublattice or bond symmetry breaking. The band gap size is controllable by changing the adsorption coverage, with an impressive maximum band gap up to 0.50 eV. The ab initio quantum transport simulation of a bottom-gated FET based on a sodium-covered silicene reveals a transport gap, which is consistent with the band gap, and the resulting on/off current ratio is up to 10(8). Therefore, a way is paved for silicene as the channel of a high-performance FET.

The high spin states of ${}^{106}$Pd have been investigated with in-beam $\ensuremath{\gamma}$-ray spectroscopic methods using the ${}^{100}$Mo(${}^{11}\text{B},1p4n$)${}^{106}$Pd reaction at a beam energy of 60 MeV. All earlier known bands were extended considerably and additional bands were identified. The configurations of these bands are discussed on the basis of the experimental aligned angular momenta and total Routhian surface calculations. Both two-quasineutron and two-quasiproton structures have been found in ${}^{106}$Pd. The nonyrast low-lying positive-parity band was interpreted as a $\ensuremath{\gamma}$-vibrational band.

High-spin states in 114In were populated using the reaction 110Pd(7Li, 3n)114In at a beam energy of 26MeV. The level scheme of 114In consisting of six bands is established up to excitation energy ∼ 5MeV and spin ∼ 17 ℏ with the addition of 58 new transitions and their configurations are discussed. The intense positive-parity dipole cascade may be interpreted as shears band based on $ \pi$ [(g 9/2)-1] ⊗ $ \nu$ [(g 7/2/d 5/2)(h 11/2)2] configuration. The $ \Delta$ I = 2 bands based on proton excitation have been observed in 114In for the first time.

Based on first-principles calculations, we investigate the electron transport properties of parallel single-walled carbon nanotube contact. A significant negative differential resistance (NDR) behavior is found due to staggered electron gratings in energy space and standing waves in real space on the two tubes induced by bias. Such a NDR effect is robust against the contact length, the tube diameter, the shape of the end, and the difference in the two electrodes. Because no bridging molecule is used, the structure of this NDR device is simpler compared with ordinary molecular NDR devices. Our findings are expected to promote the discovery of more NDR devices composed of only two electrodes in parallel contact.

Background The extended time window and theoretic reduction in hemorrhage make mechanical strategies an attractive approach for the treatment of patients with ischemic stroke. However, a limited availability of suitable animal models of cerebrovascular thrombosis has hampered the study of novel endovascular interventions. The aim of the present study was to develop a new technique for site-specific placement of a thrombus in a canine model that would allow for the evaluation of mechanical thrombectomy and clot retrieval methods and the visualization of thrombus dislocation or fragmentation during angiographic manipulation. Methods Angiography and embolization with a preformed thrombus were performed in 12 canines. Under fluoroscopic guidance, an embolism protection device (EPD) was anchored to the middle segment of the left vertebral artery (VA) via the left femoral arterial sheath. A preformed radiopaque clot was injected through the guide catheter into the left VA, via the contralateral femoral artery, proximal to the EPD. After 15 min of occlusion, the EPD was removed and persistent occlusion of the VA was documented angiographically. Results Angiography performed during the observation period confirmed the persistence of VA occlusion in each case, and displacement of the radiopaque clots did not occur during the 3-hour observation period. The technique allowed selective embolization of targeted vessels without thrombus fragmentation. Conclusion This study demonstrates, for the first time, a canine model of post-circulation embolism induced by autologous blood clot placement. This model can be rapidly formed and easily operated, and the site of thrombosis can be readily controlled.

High-spin states in 86Sr have been investigated by using in-beam γ ray spectroscopy with the 82Se(9Be, 5n)86Sr reaction at a beam energy of 53 MeV. A new dipole sequence has been observed and the mixed configurations of unpaired valence nucleons and before the alignment and the configuration after the alignment are assigned respectively. Shell-model and self-consistent titled axis cranking relativistic mean-field model calculations are performed to interpret the rotational structure and the characteristic features of magnetic rotation have been presented for the sequence.

A thermostable catalase in engineered bacterium E. coli was purified to electrophoretic homogenenity by heat treatment, ammonium sulfate fractionation precipitation, DEAE-A50 ion exchange chromatography, HiPrep 16/10 Phenyl hydrophobic interaction chromatography and Superdex200 HR 10/30 size exclusion chromatography with 187.2-fold purification and 9.8% recovery. The optimum reaction temperature and pH of this recombinant catalase were 70 degrees C and 7.0 respectively. The catalase is stable below 60 degrees C and at pH range 3-8. The residual activity of the catalase was about 60% after treated at 70 degrees C for 60 minutes and 80 degrees C for 10 minutes. The apprant Km and Vmax value of the catalase were 7.75 mmol/L and 27.8 mmol.min-1.mg-1 respectively. The affects of some metal ions and compounds on this enzyme were shown. Zn2+, Ba2+, Mn2+ of 1 mmol/L could completely inactivate the enzyme, EDTA of 50 mmol/L had no affect on activity.

By using first-principles calculations, we predict that an in-plane homogenous electrical field can induce half-metallicity in hydrogen-terminated zigzag silicene and germanene nanoribbons ( ZSiNRs and ZGeNRs ). A dual-gated finite ZSiNR device reveals a nearly perfect spin-filter efficiency (SFE) of up to 99% while a quadruple-gated finite ZSiNR device serves as an effective spin field effect transistor (FET) with an on/off current ratio of over 100 from ab initio quantum transport simulation. This discovery opens up novel prospect of silicene and germanene in spintronics.

By performing first-principle quantum transport calculations, we predict a giant magnetoresistance in zigzag silicene nanoribbons (ZSiNRs) connecting two semi-infinite silicene electrodes through switch of the edge spin direction of ZSiNRs. Spin-filter efficiency of both the antiferromagnetic and ferromagnetic ZSiNRs is sign-changeable with the bias voltage. Therefore, potential application of silicene in spintronics devices is suggested.