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By employing a mixed-ligand strategy, two new coordination polymers with the chemical formulae [Co(4-bptzh)(1,3-BDC)] (1) and [Zn(4-bptzp)(1,3-BDC)]n (2) are hydrothermally synthesized using two flexible bis(pyridyl-tetrazole) ligands (4-bptzh = 1,4-bis(5-(4-pyridyl)tetrazolyl)hexane, 4-bptzp = 1,4-bis(5-(4-pyridyl)tetrazolyl)propane) and 1,3-benzenedicarboxylic acid (1,3-H2BDC). Both complexes are characterized by single crystal X-ray diffraction along with the elemental analysis. Furthermore, the inhibitory effect of compounds 1 and 2 against CNE-1 nasopharyngeal cancer cells are evaluated in vitro. Firstly, the antiproliferation activity of compounds 1 and 2 against cancer cells is assessed by the CCK-8 assay. Then, the cancer cell apoptosis is measured with the Annexin V-FITC/PI apoptosis assay by flow cytometry.

The present study was conducted to determine the effect of exogenous application of brassinolide (BR) on Leymus chinensis grown under shade, i.e., control (100% natural light), mild shade (70% natural light), and moderate shade (50% natural light). Shade substantially enhanced the plant growth, synthesis of photosynthetic pigments, photosynthetic efficiency, and chlorophyll (Chl) fluorescence attributes of L. chinensis as compared with control. The order of increase was mild shade > moderate shade > natural light except Chl content, where the order of increase was moderate shade > mild shade > natural light. Likewise, application of BR resulted in further exacerbation of plant height, plant fresh and dry mass, but less in case of Chl and carotenoids contents, gas-exchange characteristics, and Chl fluorescence attributes. The results conclude that shade significantly enhanced plant growth through alterations in physiological attributes of L. chinensis, while, application of BR may not further improve the plant growth under shade.

This study aimed to develop a new vector system to remove selection genes and to introduce two or more genes of interest into plants in order to express them in a coordinated manner. A multigene expression vector was established based on pCamBIA2300 using a selectable marker gene (SMG)-free system based on the combination of the isocaudamer technique and double T-DNA. The vector DT7 containing seven target genes was constructed and introduced into tobacco using Agrobacterium-mediated transformation. Twenty-one of 27 positive transgenic plants contained both T-DNA regions. The co-transformation frequency was 77.8 %. The frequency of unlinked integration of two intact T-DNAs was 22.22 % (6/27). The frequency of removal of SMG from transgenic T1 plants was 19.10 %. These results suggest that this vector system was functional and effective for multigene expression and SMG-free transgenic plant cultivation. At least seven target genes can be co-expressed using this system. Overall, these findings provide a new and highly effective platform for multigene and marker-free transgenic plant production.

In this report, the band alignment related issues for high-k gate stacks have been discussed and the band engineering has been studied by combinational characterization of in-situ x-ray photoemission spectroscopy (XPS), high resolution transmission electron microscopy (HRTEM) and first-principles calculations based on density functional theory (DFT). The results show that band alignments at metal-gate/high-@k interfaces can be engineered to satisfy the application for CMOS devices through the interface structure-control.

To elucidate the initial growth of metal on oxide surface, we studied adsorption of small nickel clusters, Nin (n = 1–5), on MgO(0 0 1) surface using first-principles method based on density-functional theory. It was found that the preferential adsorption site for an isolated Ni atom is directly above the surface oxygen atom. A strong covalent bond with partial ionic character is formed between the Ni adatom and the surface oxygen atom. Various structures were considered for the Nin isomers and 3D structures were found to be energetically more stable than 2D structures for clusters of more than two atoms. For the 2D clusters, metal–metal bonds prevail over metal-substrate bonds with increasing Ni coverage. The calculated work function and ionization energy were found to vary with Ni coverage which is attributed to the change of the surface dipole moment upon metal adsorption, while the evolution of Schottky barrier height at the initial growth stage is dominated by the adatom-induced gap states.

Fermi level evolution and Schottky barrier height (SBH) for Ni/MgO(0 0 1) interfaces have been studied using X-ray photoelectron technique. It was found that upward band bending occurred at the initial Ni growth stage and Ni bulk properties recovered after 6–8 A thickness. The measured Schottky barrier heights are strongly interface structure-dependent, with the variation in the range of 3.1 eV for perfect interface to 1.6 eV for defect-rich interface. First-principles calculations on the evolution of SBH for the initial growth of Ni on perfect MgO(0 0 1) surface are combined with experimental results to investigate the underlying microscopic mechanism. Adatom-induced states (or interfacial bonding states), MIGS and defects states were used to rationalize the evolution of Fermi level and corresponding SBH for various interface structures. This work shows that SBH can be engineered by interface structure control, and is expected to shed light on the effect of interface structures on the formation mechanism of SBH at metal/oxide interface.

The epitaxial ZrO2 on silicon as alternative gate dielectric, including film growth, interface characterization and electronic structure calculations, have been studied using a combination of characterization tools. The films grown by pulsed laser deposition have high-quality microstructure and electrical properties. The atomic structure and band alignment at the ZrO2/Si interfaces have been determined by high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. Relative stabilities and electronic properties of interface structure have been discussed and compared from the view of experimental and calculated results.

First-principles calculations based on density-functional theory and generalized gradient approximation were performed to study the interface structures of epitaxial ${\mathrm{NiSi}}_{2}$ and ${\mathrm{CoSi}}_{2}$ on a $\mathrm{Si}(001)$ substrate. A sevenfold-$Z$ model with zigzag Si-dimer rows in the interface layer is proposed. The model is energetically comparable to an established sevenfold-$R$ model and they could coexist in both ${\mathrm{CoSi}}_{2}∕\mathrm{Si}$ and ${\mathrm{NiSi}}_{2}∕\mathrm{Si}$ structures, leading possibly to degradation of the interface quality of the silicide/silicon heterostructure.

We report a method for chemical tuning of band alignments for metal gate/high-$\ensuremath{\kappa}$ oxide interfaces. A heterovalent metal interlayer was included between the metal gate electrode and high-$\ensuremath{\kappa}$ oxide. Based on our first-principles calculations for $\mathrm{Ni}∕\mathrm{Zr}{\mathrm{O}}_{2}(001)$ interfaces, a tunability as wide as $2.8\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ can be achieved for the effective work function of metal gate on high-$\ensuremath{\kappa}$ oxide which far exceeds the required tuning range. In addition, we found a simple linear relationship between the effective metal work function and the electronegativity of interlayer metal atom for most of the transition metals considered. The localized interfacial dipole was found to dominate the contribution to the formation of Schottky barrier heights at metal/dielectric oxide interfaces.

First-principles calculations for $\mathrm{Zr}{\mathrm{O}}_{2}∕\mathrm{Si}$ interfaces are presented. Various model interfaces satisfying the general bonding rules were considered. The interface formation energies were evaluated as a function of oxygen potential, which shows the possibility of atomic control of the interface structure by altering the chemical environment. The strain mode and interface structure effects on band offset were investigated. The band offsets were found strongly dependent on the strain modes and interface structures. These results suggest that in epitaxial growth of $\mathrm{Zr}{\mathrm{O}}_{2}$ on Si for gate dielectric applications, the chemical environment should be well controlled to get reproducible band offsets.

Schottky barrier heights (SBHs) at metal gate/LaAlO3 (001) interfaces were studied by using ab initio calculations based on density functional theory. Three kinds of metals, Al, Rh, and Pt, were considered with various interface chemistries on LaAlO3 (001) surface. It was found that the Fermi level of metal gates is not pinned at metal gate/LaAlO3 interfaces. The SBH is largely determined by the interface chemistry. The interface metal up to three layers can ultimately decide the SBH, and the SBH at the metal gate/LaAlO3 interface can be efficiently tuned by including monolayer heterovalent metal at the interface.

The Schottky-barrier heights for the Ni and ZrO2 interfaces have been determined using the x-ray photoemission method. Depending on the surface treatment of ZrO2, the variation of Schottky-barrier heights at Ni∕ZrO2 interfaces was found as large as 0.76±0.10eV. The p-type Schottky-barrier height for the oxygen-rich (oxygen-deficient) interface was measured to be 2.60eV (3.36eV). First-principles calculations provide a microscopic explanation of such variation, which was attributed to the different interface dipole formed by interfacial Ni–O, Ni–Zr bonds, or oxygen vacancies.

The energy-band alignments for the ZrO2∕Si, ZrO2∕Si0.75Ge0.25, and ZrO2∕Ge interfaces have been studied using x-ray photoemission. The valence-band offsets of ZrO2∕Si, ZrO2∕Si0.75Ge0.25, and ZrO2∕Ge interfaces are determined to be 2.95, 3.13, and 3.36eV, respectively, while the conduction-band offsets are found to be the same value of 1.76±0.03eV for three interfaces. The upward shift of valence-band top accounts for the difference in the energy-band alignment at three interfaces.