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Carbon-based material has been regarded as one of the most promising electrode materials for potassium-ion batteries (PIBs). However, the battery performance based on reported porous carbon electrodes is still unsatisfactory, while the in-depth K-ion storage mechanism remains relatively ambiguous. Herein, we propose a facile “in situ self-template bubbling” method for synthesizing interlayer-tuned hierarchically porous carbon with different metallic ions, which delivers superior K-ion storage performance, especially the high reversible capacity (360.6 mAh·g−1@0.05 A·g−1), excellent rate capability (158.6 mAh·g−1@10.0 A·g−1) and ultralong high-rate cycling stability (82.8% capacity retention after 2,000 cycles at 5.0 A·g−1). Theoretical simulation reveals the correlations between interlayer distance and K-ion diffusion kinetics. Experimentally, deliberately designed consecutive cyclic voltammetry (CV) measurements, ex situ Raman tests, galvanostatic intermittent titration technique (GITT) method decipher the origin of the excellent rate performance by disentangling the synergistic effect of interlayer and pore-structure engineering. Considering the facile preparation strategy, superior electrochemical performance and insightful mechanism investigations, this work may deepen the fundamental understandings of carbon-based PIBs and related energy storage devices like sodium-ion batteries, aluminum-ion batteries, electrochemical capacitors, and dual-ion batteries.

Tumor hypoxia has been considered to induce tumor cell resistance to radiotherapy and anticancer chemotherapy, as well as predisposing for increased tumor metastases. Therefore, strategies for the eradication of the hypoxic tumor are highly desirable. Photodynamic therapy (PDT) is a new technique that can be used to treat tumors using laser irradiation to photochemically activate a photosensitizer. Compared to traditional radiotherapy and chemotherapy, photodynamic therapy has many advantages, such as good selectivity, low toxicity, and less trauma and resistance. However, PDT is oxygen-dependent, and the lack of oxygen in hypoxic tumors renders photodynamic therapy ineffective. Cyanobacteria, the earliest photosynthetic oxygen-generating organisms, can utilize water as an electron donor to reduce CO2 into organic carbon compounds along with continuously releasing oxygen under sunlight. Inspired by this, herein, cyanobacteria were used as a living carrier of photosensitizer conjugated upconversion nanoparticles (UCNP) to construct a self-supplying oxygen PDT system. Improvement in the PDT efficiency for hypoxic tumors can be achieved as a result of in situ oxygen production by cyanobacteria under near-infrared (NIR) light using UCNP as a light harvesting antenna. A successful demonstration of this concept would be of great significance and could open the door to a new generation of carrier systems in the field of hypoxia-targeted drug transport platforms.

Medium-chain triacylglycerol (MCT) is widely used in infant formulas (IFs) to provide medium-chain fatty acids (MCFAs) for infants with special fat absorption requirements. However, MCFAs naturally present in human milk are medium-and long-chain triacylglycerols (MLCTs). This study investigated the effect of triacylglycerol containing MCFAs (MLCT vs MCT) on lipolysis by comparison of human milk and IFs containing 0, 20, 30, and 55% of MCT (IF 1 to IF 4) using an in vitro digestion model. Rabbit gastric lipase showed an extent of digestion within the expected range, and was selected as the alternative to human gastric lipase. All IFs showed a lower lipolysis degree compared with human milk. There was no significant difference (p = 0.175) among IFs supplemented with MCT at the end of intestinal digestion. In addition, the digestion of IFs with different MCT contents led to different free fatty acid profiles, which may have health effects on infants.

The electron transport properties of polycyclic aromatic hydrocarbons (PAHs) with different numbers of benzene rings tethered to narrow zigzag graphene nanoribbon (ZGNR) electrodes have been investigated. Results show that the transport properties of PAHs are dependent on whether the number of benzene rings in the width direction is odd or even. This effect is strong for narrow width PAHs, but its strength decreases as the width of the PAH is increased. PAHs with an odd number of rings exhibit poor transport properties, whereas the ones having an even number of rings show excellent transport properties coupled with a negative differential resistance (NDR) effect. Moreover, the linkage points and the structure of the molecules have a noticeable effect on the transport properties of the PAH, making the odd-even effect weaker or disappear entirely. Although the PAH with three benzene rings displays poor transport capabilities, it shows excellent rectification behavior compared to the other examined molecules. These studies present a feasible avenue for designing molecular devices with enhanced performance by the careful manipulation of the PAH molecular structure.

The chirality-dependent property of CNTs hinders their application in next-generation electronic devices. There is thereby an urgent need to explore new 1D nanotubes with stable and controllable electronic properties. Here, we investigate the charge transport properties of several BAs nanotubes (BAsNTs) with different shapes by using first-principles density functional theory (DFT) and non-equilibrium Green's function (NEGF) methods. It is found that these BAs nanotubes are all semiconductors regardless of chirality and cross section shape, and their band gaps are very close (∼1 eV), which could overcome the chirality-dependent property shortcoming of CNTs and thus make them potential candidates for application in the field of electronic devices. In addition, we demonstrate that the encapsulation of H2O, CO2 and SO2 molecules has different effects on the BAsNTs with different cross section shapes. Particularly, when inserting H2O into the circular BAsNT, the negative differential resistance (NDR) phenomenon and a metal–semiconductor transition are observed. This novel characteristic makes BAsNTs potential candidates for application in gas sensors. The discovery may provide new opportunities for the design of next-generation BAsNT-based electronic devices and gas sensors.

Tumor vaccine has shown outstanding advantages and good therapeutic effects in tumor immunotherapy. However, antigens in tumor vaccines can be easily cleared by the reticuloendothelium system in advance, which leads to poor therapeutic effect of tumor vaccines. Moreover, it was still hard to monitor the fate and distribution of antigens. To address these limitations, we synthesized a traceable nanovaccine based on gold nanocluster-labeled antigens and upconversion nanoparticles (UCNPs) for the treatment of melanoma in this study. PH-sensitive Schiff base bond is introduced between UCNPs and gold nanocluster-labeled ovalbumin antigens for monitoring antigens release. Our studies demonstrated that UCNPs conjugated metallic antigen showed excellent biocompatibility, pH-sensitive and therapeutic effect.

By using DFT method, we stitch monolayer MoS2 nanoflakes with different manners to tune the behaviors. The stability of these structures is identified by molecular dynamics simulations. The effect of chemical modification is also given and assessed by the calculated edge adsorption energy. It is found that the electronic structures can be manipulated from semiconducting to metallic properties by different edge modifications. The prototypes can also be constructed into three-terminal FET which owns smaller value of subthreshold swing S and the considerable transconductance G comparable to that of experiments. More importantly, we utilize the spin-transport properties to achieve a kind of voltage-driven spintronic logic gates. We control the spin transport with the electric field only and find the model can function in all base ‘AND’, ‘OR’, ‘NOT’ logic operations under specific combinations of the gate bias. The advantages of monolayer MoS2 nanoflakes are thus expected.

Recently, new researches on van der Waals (vdW) two-dimensional bilayer heterostructures have been carried out owing to their unique properties different from single-layer materials. Herein, three types of bilayer heterostructures, phosphorene/graphene, phosphorene/silicene and phosphorene/germanene are constructed and their electronic transport properties are calculated based on the first-principle method. The results show that their I-V curves are totally different that the phosphorene/graphene devices have higher electron transmission probability, resulting in higher current values. Furthermore, we calculate their band structures to explore the internal mechanism of current difference. The graphene-like Dirac cones are found in the bilayer phosphorene/graphene heterostructures. However, the positions of their Dirac cones in the Brillouin zone are markedly different from that of graphene. But when the silicene or germanene is combined with the phosphorene together, the Dirac cones of the silicene or germanene disappear, instead, there are band gaps of about 0.2 eV around the Fermi level. Our results suggest that the Dirac cone can be mainly retained by the weak hybridization between monolayer phosphorus and 2D Dirac materials. Due to the existence of the Dirac cone, the overlap between the source and drain electrodes increases, which leads to a larger current value. This discovery of the Dirac cones in the bilayer heterostructures is applicable in designing Dirac materials and understanding their electronic transport properties.

Triacylglycerol (TAG) composition of breast milk plays an important role in improving digestion, absorption, and metabolism when consumed by infants. This study characterized the TAG profile of human colostrum, transitional, and mature milk samples from 103 women. Significant differences in the TAGs composition of breast milk fat from three lactation stages were observed. The TAGs with high molecular weight and unsaturated fatty acid (such as 1,3-olein-2-palmitin (OPO) and 1(3)-olein-2-palmitin-3(1)-linolein (OPL)) were enriched in colostrum, while the TAGs containing medium-chain fatty acids were more abundant in transitional and mature milk than that in colostrum. Of note, OPL was the most common TAG in breast milk of Chinese women while the most common TAG in breast milk of Western women was OPO. This data will promote the development of infant formulas in terms of the TAG composition more suitable for infants.

The electronic structures of the C and O-doped black phosphorene are investigated theoretically by using first-principles density functional theory (DFT). The results show that they are all metallic. And the black phosphorus nanotubes (BPNTs) rolled from the pure, C-doped and O-doped black phosphorene with different radii and chiralities are also studied. C and O atoms substitute for P atoms enable the armchair BPNT to have a metallic feature with several bands cross the Fermi level. Surprisingly, the number of the bands cross the Fermi level just equals the number of dopant atoms. But for the zigzag BPNT, when the O atoms decrease to 4, no band crosses the Fermi level and at which a minimal energy gap appears. Furthermore, the transport properties of two-probe devices fabricated by the pure A24 and Z34 BPNTs together with the C-doped A24 BPNTs are investigated theoretically. These calculated results show that the electronic transport properties of the A24 BPNT can be significant changed by C dopant atom and vary with the number of the doped atoms. The current-voltage curves of these BPNTs with C atoms substitute for P atoms present sinusoidal characteristics under low bias and negative differential resistance (NDR) properties. This study provides an effective route for tuning the electronic structures of black phosphorene and BPNTs and thus the transport properties of their electronic devices. And the unique properties of these black phosphorene and BPNTs also offer an inspiration for their subsequent experiments.

Electron transport properties of optimized typical SimCn/Cn clusters, including Si4C, Si8C5, Si9C6, C6, C12 and C13, connected to zigzag graphene nanoribbon (ZGNR) electrodes are theoretically studied through first-principles density functional theory (DFT). As for Si4C, Si8C5, Si9C6 clusters, the transmission values at the fermi level show a decreasing tendency with the increase in the number of carbon and silicon atoms. Interestingly, Si9C6 cluster with ring structure (C6) has poor electron transport properties in spite of C6 showing good electron transport properties. Although C12 cluster shows smaller transmission values at the fermi level, when adding an atom to it, - C13 shows excellent electron transport properties. The electrode coupling of ZGNR-C12 is the strongest compared with ZGNR-C6 and ZGNR-C13 because it forms sp3 orbital which has stronger bond. Our findings may pave a new path for the exploration of nano electronics.

Chemical decorated heterojunction Pb/Pb-Si nanochain devices and their electron transport properties are systematically investigated. These Pb-Si nanochain heterostructures are found to show semimetal and graphene-like properties on electronic transport. Particularly, some devices show some excellent performance with large on-off ratios, small sub-threshold swing and high peak-to-valley ratio (PVR). A link between heterojunction mode and semiconductor-semimetal-metal transformation characteristic has been built. In addition, multi-peak negative differential resistance (NDR) effect has been observed on this heterostructure. Moreover, the performance of heterojunction Pb/Pb-Si nanochain devices is observed to be effectively modulated by gate potential. These findings are very valuable for potential implications for the design of high-performance new-generation microelectronic devices.

Two dimensional (2D) materials consist of one to a few atomic layers, where the intra-layer atoms are chemically bonded and the atomic layers are weakly bonded. The high bonding anisotropicity in 2D materials make their growth on a substrate substantially different from the conventional thin film growth. Here, we proposed a general theoretical framework for the epitaxial growth of a 2D material on an arbitrary substrate. Our extensive density functional theory (DFT) calculations show that the propagating edge of a 2D material tends to align along a high symmetry direction of the substrate and, as a conclusion, the interplay between the symmetries of the 2D material and the substrate plays a critical role in the epitaxial growth of the 2D material. Based on our results, we have outlined that orientational uniformity of 2D material islands on a substrate can be realized only if the symmetry group of the substrate is a subgroup of that of the 2D material. Our predictions are in perfect agreement with most experimental observations on 2D materials’ growth on various substrates known up to now. We believe that this general guideline will lead to the large-scale synthesis of wafer-scale single crystals of various 2D materials in the near future., Advances in our ability to manipulate genetics leads to deeper understanding of biological systems. In this perspective, the authors argue that synthetic genomics facilitates complex modifications that open up new areas of research.

This study aimed to quantify the short-chain fatty acids (SCFAs) and medium-chain fatty acids (MCFAs) in human milk triacylglycerols (TAGs) and investigate their concentrations in human milk consumed during lactation by infants born at different gestational ages. One hundred and eighty milk samples from the mothers of 30 full-term, 10 early-preterm (≤32 weeks), 10 mild-preterm (32–34 weeks), and 10 near-term (34–37 weeks) infants were collected from the colostrum, transitional, and mature milk. The human milk TAGs were transferred into fatty-acid methyl esters via potassium methoxide in methanol and determined using gas chromatography (GC). The total SCFA (4:0) and MCFA concentrations (6:0 and 8:0) were highest in the mature milk (1.47 ± 0.66 mg g−1 fat from full-term infant milk), approximately 42.18% higher than those in transitional milk. Significantly higher SCFA and MCFA concentrations were found in full-term milk than in preterm milk (p = 0.001). The milk TAGs were analyzed using ultra-high-performance supercritical fluid chromatography with quadrupole-time-of-flight mass spectrometry (UHPSFC-Q-TOF-MS), which showed that the SCFAs and MCFAs were mainly esterified with long-chain fatty-acid groups (16:0, 18:1 n-9, and 18:2 n-6) at the glycerol backbone. The infants’ daily SCFA intake from human milk was estimated; this was highest from mature milk for full-term infants (∼14 mg d−1) which was significantly different from that of preterm infants from colostrum and transitional milk (p < 0.001). The correlation between dietary SCFAs and MCFAs in human milk and nutrition in newborns, especially in the gut microbiotas of preterm infants, requires further study.

Molecular dynamics (MD) simulations have been performed to confirm the existence of liquid-liquid phase transition (LLPT) in nanoconfined Si-rich SiO2 liquid with different ratio of oxygen to silicon. The typical feature of the LLPT is layering transition which is induced by the change of slit size (SS) and pressure parallel to wall (P//). Abnormal shoulder peak between the first and second peaks in pair correlation function as a result of the change of SS and P// is another indication of the LLPTs. The structural evolution of the liquid layers during the LLPT is well explained by the change in angular correlation function. Moreover, the density, pressure perpendicular to walls, average potential energy and diffusion coefficient show abrupt change during the LLPT. LLPTs are similar in layering transition in different liquids but their appearances are not synchronous.

Combined chemo/chemodynamic therapy is a promising strategy to achieve an improved anticancer effect. However, the hypoxic microenvironment and limited amount of H2O2 in most solid tumors severely restrict the efficacy of this treatment. Herein, the construction of a nanocatalytic medicine, CaO2@DOX@ZIF‐67, via a bottom‐up approach is described. CaO2@DOX@ZIF‐67 simultaneously supplies O2 and H2O2 to achieve improved chemo/chemodynamic therapy. In the weakly acidic environment within tumors, CaO2@DOX@ZIF‐67 is broken down to rapidly release the Fenton‐like catalyst Co2+ and the chemotherapy drug doxorubicin (DOX). The unprotected CaO2 reacts with H2O to generate both O2 and H2O2. The generated O2 relieves the hypoxia in the tumor and further improve the efficacy of DOX. Meanwhile, the generated H2O2 reacts with Co2+ ions to produce highly toxic •OH through a Fenton‐like reaction, resulting in improved chemodynamic therapy., The hypoxic microenvironment and limited amount of H2O2 in most solid tumors severely restrict the efficacy of chemotherapy and chemodynamic therapy, respectively. Herein, a nanocatalytic medicine, CaO2@DOX@ZIF‐67, is synthesized via a bottom‐up approach. By virtue of simultaneously producing O2 and H2O2 under acidic conditions, the fabricated nanocatalytic medicine can eliminate hypoxic tumors via enhanced chemo/chemodynamic therapy.

To detect arsenic geochemistry and evaluate its environmental risk, 30 geothermal water samples were collected from Rehai and Ruidian geothermal fields of Tengchong, China. There were three main water types including SO 4 and Na-Cl-HCO 3 types in Rehai and Na-HCO 3 type in Ruidian. Arsenic concentrations ranged from 22.1 to 1150.3 μg L −1 . Relative high concentrations of arsenic with an average of 495.1 μg L −1 , as well as K, Na, F, Cl, Li and B, were detected in neutral or alkaline geothermal water samples, which suggested that rock leaching in geothermal reservoir was the main resource of arsenic enrichment in geothermal water. Comparatively, those acid geothermal water samples which were formed by vapor rich in H 2 S condensing and oxidizing in the shallow groundwater or surface water had lower arsenic concentrations with an average of 77.1 μg L −1 . The ratios of arsenite to total arsenic widely ranged from 0.01 to 0.97 and were determined by mixing proportions of geothermal water and shallow groundwater or surface water. Furthermore, there was a significantly positive correlation between arsenic with HCO 3 (R = 0.81, P = 0.01). These results implied that shallow groundwater or surface water in Tengchong geothermal area had been probably contaminated by arsenic due to the mixing of geothermal water.

A facultative anaerobic iron reducing bacterium IMCUGIR-ZA was isolated from high arsenic (As) groundwater in Hetao Basin of Inner Mongolia and was identified as Klebsiella oxytoca. Strain IMCUGIR-ZA could reduce more than 96.8% of 2.78 mmol L−1 soluble Fe(III)-citrate in 7 days and 0.42 mmol solid iron from ferrihydrite into aqueous phase in 10 days using glucose as an electron donor under strictly anaerobic conditions. Appropriate concentrations of As could improve microbially-mediated iron reduction and release from ferrihydrite. Nearly threefold iron was reduced and released by strain IMCUGIR-ZA from As(V)-doped ferrihydrite (As 100 μmol L−1). When the strain was incubated with high arsenic sediments from Hetao Basin of Inner Mongolia under anaerobic conditions, 0.894 mmol L−1 Fe(III) and 12.44 μmol L−1 As were released to aqueous phase in 7 days. The results provided evidence of microbially-mediated mobilization of As in high arsenic groundwater aquifer in Hetao Basin of Inner Mongolia, China.

The electronic structures of the armchair Fe2Si nanotubes are calculated by using the SGGA+U method. Novel heterostructure devices are prepared composed of single-wall Fe2Si nanotubes (Fe2Si NTs) and carbon nanotubes (CNTs). The results indicate that the (4,4) Fe2Si NT is a ferromagnetic half metal with 100% spin-polarization ratio at the Fermi energy level. These heterojunctions have spin-polarized transport properties but their spin-polarization ratios are relatively low. Interestingly, the (13,0) CNT–(n,n) Fe2Si NT–(13,0) CNT devices are all semiconductors but others are metallic. This study suggests that adding the novel Fe2Si NTs endows the CNTs with spin-polarized property and provides very valuable results for better understanding of the electronic structures of the heterostructure.

The potential application of nanotechnology is based on the integration of microelectronic function with advanced group IV element technology, such as silicon-based field-effect transistors. In this paper we investigate theoretically the electronic transport properties of lead nanowires doped with silicon by employing molecular dynamics simulations and the non-equilibrium green function method with density functional theory frame. We observed the conductance of lead wires with silicon doping shows ballistic feature and high doping concentration wire have more intense oscillation amplitude because of the resonance transmission peak and the transmission channels. Importantly, the initial cause of negative differential resistance (NDR) effect and bonding mechanism in lead-silicon system have also given explanation.

There is a growing awareness that the structures of boron phosphide (BP) nanoribbons have a significant impact on their electronic transport properties, which will further affect their application in many fields, including energy conversion and nanoelectronic devices. By using the first principle density functional theory and non-equilibrium Green's function calculations, we investigate the electronic transport properties of graphene-like hexagonal zigzag BP nanoribbons with edges terminated by hydrogen atoms (–H) or hydroxyl groups (–OH) and the effect of twisting and bending deformations on their transport properties. Our results show that the electronic transport properties of the BP-H nanoribbons become poor after twisting to 45°, while twisting does not reduce the electronic transport properties of BP-OH nanoribbons. When we combine BP-H and BP-OH nanoribbons into a heterosheet, the effect of twist angle is similar to that for the BP-H nanoribbon. Another interesting finding is that for the BP-OH nanoribbons, there is a significant negative differential resistance (NDR) with a giant peak-to-valley ratio (PVR) of up to 90 when it is curled into an arch, which can be applied as an electric switch. Our detailed insights may provide a novel strategy to tune the electronic transport properties of BP nanoribbon-based structures.

Human milk is a natural source of medium-chain fatty acids (MCFAs). It is generally acknowledged that MCFAs exist in medium-chain triacylglycerols (MCTs). However, a previous study revealed that human milk is naturally rich in medium- and long-chain triacylglycerols (MLCTs). Few data are available on the MLCT composition of preterm milk. This study compared the MCFA and MLCT profiles in human milk from mothers after preterm (28–37 weeks) and term (>37 weeks) delivery during three lactational stages. The results showed that almost half of the triacylglycerol species in human milk are MLCT, accounting for approximately 30% of the total TAGs, mainly composed of one MCFA and two long-chain fatty acids, that is, MLL-type MLCT. In addition, MCFAs and MLCTs showed an increase from colostrum to transitional milk, while they were comparable between preterm and full-term milk. This research could help to develop infant formula, which is of great significance for infants.

Significant endeavors have been made to predict the van der Waals (vdW) heterostructures consisted of boron arsenide (BAs) and boron phosphide (BP) sheets, which are indispensable for next-generation nanoelectronic devices. Theoretical results show that the BP intercalation in the BAs/BP sandwiched heterostructures induce a peculiar semiconductor-metal transition, and further results in a dramatic increase in the electronic current, very different from the pure BAs and BP sheets. More strikingly, when a small BP nanotube is inserted into a larger BAs nanotube, because of the rotation between the inner and outer tubes, also leading to the similar semiconductor-metal transition. The semiconductor-metal transition in the sandwiched heterostructures composed of BAs and BP sheets gives a theoretical support for the fundamental science and device technologies and provides a possible approach to design conducting heterostructures by different monolayer semiconductors.

The atomic arrangements in the crystalline silicon (c-Si) and amorphous silicon (a-Si) are distinctly different, which affects the surface restructuring during oxidation and the resulting Si/oxide interfacial structures. Here, based on reactive molecular dynamics simulations, we elucidate that the amorphous-structure-promoted oxidation of silicon is associated with the structural defects in the a-Si. Randomly distributed structural defects on the surface of the a-Si not only induce a “selective adsorption” of O2 which facilitates the dissociation, but also cause the oxides to nucleate like islands and combine into the oxide film, in comparison to the layer-by-layer oxide growth on the c-Si surface. Moreover, the defects in the a-Si provide an easy pathway for the penetration of oxygen into the a-Si structure, thus resulting in higher oxidation rate and thicker oxide layer than those in the c-Si. The phase separation and thermal crystallization of the amorphous oxide films at high temperatures are also discussed in depth. This study provides a better understanding of the crucial role of atomic structure in determining the oxidation mechanism, the oxide growing kinetics and the resulting oxide structures on silicon, which suggests the key to fabricate ultra-thin oxide films to fulfill the specific requirements of microelectronic and photovoltaic applications.

Classical molecular dynamics simulations have been performed to study the atomic structures and thermal expansion of coordination shells in solid and liquid Invar alloys. Analysis of atomic structures reveals that there is an attraction between Fe-Ni nearest pairs, and that structural order still exists in the liquid Invar alloy. Fe—Ni bonds are found to have the smallest thermal expansion in the solid Invar alloy among three types of bonds, which plays an important role in the Invar effect. We also discover that the thermal expansion coefficient will gradually get close to the macroscopic level as the coordination shell number increases in Invar alloys. It is until the 5th coordination shell in the solid state and the 4th coordination shell in the liquid state that the thermal expansions of the coordination shells can reach the macroscale value. This study further promotes the understanding of the thermal expansions from the atomic scale.

We employ first-principles density functional theory (DFT) calculations to study CH3NH3PbX3 (X = I, Br) and its encapsulation into the silicon carbide nanotube and carbon nanotube (CNT). Our results indicate that these devices show diode behaviors which act on negative bias voltage but do not work under positive voltage. When they are encapsulated into SiC nanotube and CNT, their electronic properties would be changed, especially, electric currents mainly exist at positive bias region. Corresponding transmission spectra and density of states are provided to interpret the transport mechanism of the CH3NH3PbX3 (X = I, Br) as a diode. These findings open a new door to microelectronics and integrated circuit components, providing theoretical foundation for innovation of the new generation of electronic materials.

Magnetism of Fe-Ni system is calculated from the first-principles. Results show that the atomic magnetic moments are determined by their local surrounding atoms. In both FM and AFM cases, the Fe atomic magnetic moment declines with increasing number of Fe atoms in its local surroundings. The relation between atomic volume and atomic magnetic moment indicates that Fe-rich local surroundings would cause relatively small volumes. Our work is of significance to understanding the relation between the local surroundings with anomalous thermal expansion coefficient in the Invar alloy.

Carbon based nanostructures play an important role in the development of new devices in order to sustain Moore's law. In this work, taper, fusiform and hourglass shaped structures sandwiched between two carbon-based electrodes are proposed for the first time to achieve a range of potential applications. The transport properties of these structures were also investigated based on density functional theory (DFT) combined with nonequilibrium Green's function (NEGF) formalism. It was found that the negative differential resistance (NDR) phenomena appeared only in the fusiform shaped device, while I-V curves for the other devices showed that they obeyed Ohm's law. Interestingly, the spin polarization rate of the taper device is almost 100%, which implies that this device could be utilized to filter current according to a particular spin direction. In addition, high rectification ratios and spin diode functionality were also obtained. The microscopic physics responsible for these fascinating properties have also been given explanations through the transmission spectrum, the transmission eigenstates and the density of states.