Search

Lead-free (Bi0.5Na0.5)1-xSrxBi4Ti4O15 ceramics (x = 0–0.9) are fabricated by solid state reaction process. XRD analysis shows the symmetry divergence from tetragonal to orthorhombic phase accompanied by morphotropic phase boundary with increasing strontium content. Raman spectra confirm the incorporation of strontium into (Bi2.5Na0.5Ti4O13)2- layers. SEM graphs exhibit the typical plate-like morphology with regular variation of grain size and crystallization as strontium increases. Multistage ferroelectric transition is observed with x = 0.2–0.4. Piezoelectric performance measurements present the well thermal stability at x = 0.4. The dielectric properties display a shifting of Curie temperature towards low temperature with increasing strontium ions. It can be due to the crystal lattice distortion by larger radius of strontium and the increasing tolerance factor. ac conductivity and impedance measurements suggest that electron hopping mainly contributes to the low temperature region. Ionization conductivity by oxygen vacancy migration including first-ionization and double-ionization plays the dominating role in the middle and high temperature region. The controllable properties indicate the potential applications for electric devices of (Bi0.5Na0.5)1-xSrxBi4Ti4O15 ceramic.

Lead-free Bi4Ti3O12/NiFe2O4 nanocomposite films have been prepared via sol-gel spin-coating route. The successful phase formation of orthorhombic Bi4Ti3O12 and cubic NiFe2O4 has been confirmed using x-ray diffraction without any detectable extra phase. The scanning electron microscopy with EDS measurement reveals homogeneous and dense growth of both phases accompanied by clear interface between the two layers. The loop of magnetization versus magnetic field indicates the ferromagnetic properties at room temperature with saturation magnetization of ~257.48 emu/cm3, coercive field of ~121 Oe and remnant magnetization of ~57.03 emu/cm3. Room-temperature ferroelectric behavior is also obtained along with the good fatigue endurance properties and low leakage current density. The frequency dependence of dielectric constant displays the monotonous decreasing tendency with low dielectric loss. Moreover, evident magnetodielectric behavior is achieved in the nanocomposite films at room temperature. The coexistence of ferromagnetic and ferroelectric behavior including the appearance of magnetodielectric effect proves the room-temperature multiferroic properties in Bi4Ti3O12/NiFe2O4 nanocomposite films, which makes the films meaningful as the lead-free multiferroic systems for device applications at room temperature.

Intergrowth ceramic series Bi4Ti3O12/Bi4.5Na0.5Ti4O15 have been prepared through solid state reaction. X-ray diffraction analysis shows the coexistence of Bi4Ti3O12 and Bi4.5Na0.5Ti4O15 phases with slight lattice distortion. Scanning electron micrographs present the growth of grains and grain boundaries with different contents of Bi4.5Na0.5Ti4O15. The relaxation dielectric properties of the ceramics have been observed. The room-temperature dielectric constant at 100 Hz is initially increased and then decreased with the increase of Bi4.5Na0.5Ti4O15. The impedance spectroscopy and the electrical modulus are also measured for explaining the dielectric behavior. The Nyquist plots display different semicircle arcs at 300 and 600 K. The imaginary part of electrical modulus has two peaks in the range of the measuring temperature. They prove the common influence of grains and grain boundaries on the dielectric properties. For further fitting the experimental data by Arrhenius theory, activation energy is obtained for grains and grain boundaries. Finally, the relaxor dielectric properties are attributed to the competition mechanism from the different growth situation of grains and grain boundaries with increasing Bi4.5Na0.5Ti4O15. Therefore, this kind of ceramics ought to be promising candidates for multifunctional device applications.

By using nanoindentation techniques combined with transmission electron microscope, wide-/small-angle X-ray scattering, and three-dimensional atom probe tomography, the sub-nanometer- to nanometer-length-scale structural heterogeneity due to the precipitation of Co(Fe)-rich clusters was observed in [(Co0.7Fe0.3)0.68B0.219Si0.051Nb0.05]100-xCux (x = 0.5) metallic glasses. Such short-range ordered structure promotes energy dissipation during deformation via regulating intrinsic elastic constants and hardness at the mesoscale, which contributes to the improved compressive plasticity of Cu-doped (Fe, Co)-based metallic glasses. Our work provides new evidence on atomic-scale heterogeneity in Cu-doped metallic glasses from the aspects of topological orders and microscopic mechanical responses.

Exchange bias behaviors up to room temperature have been observed in NiCo2O4/NiO nanoparticle system. The field-cooled magnetic hysteresis loops exhibit shifts both in the field and magnetization axes simultaneously. The variation of exchange bias field and magnetization shift depends strongly on the measuring temperature. In addition, the dependence of exchange bias effect on measuring temperature is not monotonous, which is reflected in the different tendency during the decrease process of magnetization shift and exchange bias field. The exchange bias field is decreased firstly at the range of 10–50 K followed by an increase of 50–200 K and decreased again of 200–320 K. By analyzing various magnetic measurements, the special exchange bias effect in NiCo2O4/NiO can be owing to the spin glass state and the ferrimagnetic/antiferromagnetic coupling during different temperature ranges.

The polycrystalline xBi0.5Na0.5TiO3-(1-x)NiFe2O4 solid solutions with different ratios have been synthesized by sol-gel method. The samples are respectively annealed with nonmagnetic and magnetic field annealing processes. X-ray diffraction patterns present the pure formation with coexistence of Bi0.5Na0.5TiO3 and NiFe2O4 phases. Micrographs measured with scanning electron microscope show the dense surface morphology. Evident enhancement in electric polarization and magnetoelectric coupling coefficient is observed with magnetic field annealing. As the content of Bi0.5Na0.5TiO3 increases, magnetoelectric effect is most prominent at the ratio of x = 0.7 with magnetic field annealing. These results indicate the successful influence on room-temperature magnetoelectric coupling effect by magnetic field annealing.

The 0.7(Bi 0.5 Na 0.5 ) 1- x Ba x TiO 3 -0.3NiFe 2 O 4 samples ( x = 0.02–0.12) have been synthesized through sol-gel method. Structure, micromorphology and the room-temperature multiferroic properties have been investigated, respectively. The characterization of structure and micromorphology reveals the coexistence of two different phases. In addition, lattice deformation and morphology variation can be clearly confirmed with doping Ba ions. Dielectric properties are improved evidently from x = 0.02–0.08 and then weakened from x = 0.08–0.12 with enough low values of dielectric loss for all the samples. The ferroelectric polarization demonstrates that room-temperature ferroelectric properties are monotonously enhanced with increasing content of Ba. The change tendency of magnetic properties is firstly decreasing and then increasing with the special content value of x = 0.08. Room-temperature magnetoelectric coupling effect is verified by the measurement of magnetoelectric coupling coefficient. The variation trend of magnetoelectric coupling coefficient with doping of Ba is similar to that of magnetic properties. The room-temperature multiferroic properties of 0.7(Bi 0.5 Na 0.5 ) 1- x Ba x TiO 3 -0.3NiFe 2 O 4 samples are related to the larger ionic radius of Ba. Furthermore, the special multiferroic behavior with x = 0.08 can be attributed to the morphotropic phase boundary effect with doping Ba.

The Mn0.98CoGe compound can be as alternative refrigerants due to its low cost and large magentocaloric effect near room temperature. However, the narrow work temperature range and the large thermal hysteresis restrict its application. In this work, we investigate the influence of ball milling (BM) time on the thermal hysteresis and magnetocaloric properties of Mn0.98CoGe compound. Results show that the thermal hysteresis of Mn0.98CoGe reduced markedly after BM 5 h, and disappeared completely after BM 12 h. Furthermore, the magnetic entropy change (ΔSM) over a wider temperature span are observed, which leads to the relative cooling power (RCP) of BM-12 h sample as high as those typical refrigerants.

Polycrystalline (1-x)(0.75Bi4Ti3O12-0.25Bi0.5Na0.5TiO3)-xMgFe2O4 lead-free composites were prepared through sol-gel process with different stoichiometric proportions. The influence of proportions on microstructure, morphology, magnetic and dielectric behaviors has been explored detailedly. XRD patterns and Raman measurement reveal the multiphase coexistence with increasing content of MgFe2O4 of all the samples. The surface morphology presents different distributions of grain size for different proportions. The average grain size is confirmed to decrease as the MgFe2O4 concentration increases. Room-temperature magnetic properties are evidently enhanced by increasing addition of MgFe2O4. The giant effective permittivity at room temperature is obtained for all the samples with order of magnitude of 104∼105. The variation of dielectric properties including effective permittivity and dielectric relaxation is strongly dependent on the content of MgFe2O4. Through rigorous analysis, the dielectric behavior should result from the common contributions of different conductivities and morphology variation due to the incorporation of MgFe2O4 to Bi4Ti3O12-Bi0.5Na0.5TiO3.

Materials with tunable photoluminescence (PL) are highly desirable. It can lead to important applications such as photodetectors, bio-imaging, and broadband modulators. In this work, nitrogen-doped graphene oxide quantum dots (NGOQDs) were synthesized by hydrothermal method. The microstructures as well as optical properties of NGOQDs were studied. The as-prepared NGOQDs present tunable PL and exhibit a maximal PL blue-shift of ca. 88 nm compared to that of the graphene oxide quantum dots (GOQDs). The observed PL blue-shift of the NGOQDs is attributed to the high content of pyridine-like and pyrrolic-like nitrogen atoms doping in the NGOQDs. Our proposed mechanism for the PL blue-shift of the NGOQDs is supported by density functional theory (DFT) calculations.

NiCr2O4 nanoparticles have been successfully prepared by chemical co-precipitation method. Desired crystallographic phase of NiCr2O4 is confirmed by analyzing x-ray diffractrograms. With increasing annealing temperature, crystal transition from cubic to tetragonal phase is observed. The increasing average particle size from ∼80 to ∼280 nm is studied by SEM and TEM micrographs as annealing temperature increases. Exchange bias behavior is detected at 10 K accompanied by the shift of magnetic hysteresis loops along field axis. This effect is gradually weakening as annealing temperature increases. The magnetization depending on temperature under zero-field-cooled and field-cooled conditions suggests the ferrimagnetic transition at ∼72 K and the spiral magnetic order at ∼25 K. Furthermore, the ferrimagnetic transition point shifts slightly to low temperature with increasing annealing temperature. Based on the measurement results, the appearance and evolution of exchange bias effect in NiCr2O4 nanoparticles with improving annealing temperature should be simultaneously derived from the lattice transition and the surface spin effects.

Single phase NiCr2O4 has been successfully prepared by sol–gel technique. Characterization of crystal and morphology exhibits the tetragonal structure and homogeneous growth with regular crystalline shape. Large dielectric constant of ~2447 is observed at room temperature. The relaxation behavior below room temperature is confirmed through measurements of dielectric constant, dielectric loss, electric modulus and impedance depended on frequency or temperature. The analysis through equivalent circuit simulation demonstrates the influence of grains at low temperature and the common contribution of grains and grain boundaries at high temperature. Moreover, the change in dielectric response indicates the presence of magnetodielectric coupling effect. Two different mechanisms are considered to control the magnetodielectric coupling, yielding the positive and negative coupling coefficient at different temperature ranges. The intrinsic magnetoelectric coupling gives rise to the frequency independent magnetodielectric behavior at low temperature. As temperature increases above 150 K, the large magnetodielectric coupling coefficient depended on frequency is contributed by the Maxwell-Wagner effect. The negative value of magnetodielectric coupling coefficient is attributed to the leakage current. Therefore, both mechanisms of Maxwell-Wagner and leakage are competing as a function of frequency, which results in the coefficient crossover at room temperature. Such features bring NiCr2O4 a step closer to potential applications in areas such as magnetic field sensors, actuators and others.

In this study, the characteristics of intensity and phase for the ring Airy Gaussian vortex (RAiGV) beam propagation in atmospheric turbulence were numerically simulated, based on the Split-Step Fourier Method (SSFM) and Power Spectrum Inversion Method. Also, the propagation characteristics of the RAiGV beam in the free space were studied. The results obtained showed that at the edge of the phase screen, the interference fringes exist, the phase is distorted and the equiphase line turns into an arc due to the influence of the atmospheric turbulence. Also, it is observed that the smaller the distribution factors is, the greater the change in the intensity and phase wave-front will be, but the fringes interference at the edge of the phase screen is weaker. The results will provide theoretical and technical references for atmospheric optical communication using vortex beams.

The quaternary Cu2ZnSnS4 (CZTS) is a promising material for the thin-film solar cell applications. However, because CZTS is only stabilized in a very small chemical-potential region and the defect formation is much more complicated compared to the ternary systems, it requires careful control of the thin-film solar cell preparation. We have performed a density-functional theory investigation on the intrinsic defects, defect complexes and Na doping in this complicated system. Our calculations show that the disorder and nonstoichiometry in the Cu–Zn plane induces a bandgap shrinkage of the material. From our calculated results for various defects and the doping rules, we rationalize why the experiments obtain high conversion efficiencies for the thin-film solar cells under the Cu-poor and Zn-rich conditions. The most possible defects which fulfill the experimental Cu-poor and Zn-rich conditions are V Cu , rather than Zn Cu . It is necessary to keep the Sn chemical potential moderate during the CZTS thin-film solar cell growth because the Sn-involved defects and defect complexes are generally harmful. We also find that Na doping is expected to increase the conductivity and improves the conversion efficiency of CZTS solar cells. The present study provides valuable insights into the defect physics of the complicated CZTS system and a theoretical basis for exploring its practical applications as thin-film solar cell absorbers.

Based on the experiment, this paper focuses on studying flexural behavior of splicing concrete-filled glass fiber reinforced polymer (GFRP) tubular composite members connected with steel bars. The test results indicated the confinement effects of GFRP tubes on the concrete core in compression zone began to produce, when the load reached about 50%Pu (Pu-ultimate load), but the confinement effects in tensile zone was unobvious. In addition, the failure modes of composite members were influenced by the steel ratio of the joint. For splicing unreinforced composite members, the steel ratio more than 1.96% could satisfy the splicing requirements and the steel ratio 2.94% was ideal comparatively. For splicing reinforced specimen, the bearing capacity of specimen with 3.92% steel ratio was higher 21.4% than specimen with 2.94% steel ratio and the latter was higher 21.2% than the contrast non-splicing specimen, which indicated that the steel ratio more than 2.94% could satisfy the splicing requirements and both splicing ways used in the experiment were feasible. So, the optimal steel ratio 2.94% was suggested economically. The experimental results also indicated that the carrying capacity and ductility of splicing concrete-filled GFRP tubular composite members could be improved by setting internal longitudinal rebars.

Porcine ear size is an important characteristic for distinguishing among pig breeds. In a previous genome-wide association study of porcine ear size, LEM domain-containing 3 (LEMD3), methionine sulfoxide reductase B3 (MSRB3), high mobility group AT-hook 2 (HMGA2), and Wnt inhibitory factor 1 (WIF1) were implicated as important candidate genes for ear size. This study investigated the expression levels of four candidate genes for ear size in Erhualian and Large White pigs. Ten Erhualian pigs with large ears and eight Large White pigs with small ears at 60 days of age were examined. The mRNA expression levels of the four candidate genes were quantified by real-time polymerase chain reaction. WIF1 mRNA expression was significantly higher in Large White than in Erhualian pigs (P < 0.05), whereas the expression levels of the other three genes were not significantly different between the two breeds. The protein expression levels of the four genes were analyzed using western blot. WIF1 protein expression was significantly higher in Large White than in Erhualian pigs (P < 0.01), whereas MSRB3 protein expression was significantly higher in Erhualian than in Large White pigs (P < 0.05). There were no significant differences between the two breeds in residual protein expression. These results suggest that WIF1 is the main causal gene for ear size in pigs.

We investigate the persistent spin and charge currents within an open mesoscopic ring embedded in a textured electric field. The persistent spin and charge currents are obtained analytically, and can be controlled by the electric field. Since the spin-up (down) electron can feel the different transverse spin forces generated by the spin–orbit coupling, the spin-up (down) electron will travel clockwise (anticlockwise) along the ring. As a result, the persistent charge current will change its direction within the ring according to different spin state electron injections, whilst the persistent spin current remains in the same direction. A pure persistent spin current, without any accompanying charge current, can be produced by tuning the strength and/or the angle of the textured electric field.

The signal peptide CUB EGF-like domain-containing protein 3 (SCUBE3) gene is a member of SCUBE gene family and plays important roles in bone cell biology and the determination of limb bone length. In this study, the full-length transcript of porcine SCUBE3 was cloned using reverse transcription-polymerase chain reaction and rapid amplification of cDNA ends. The full-length sequence of porcine SCUBE3 cDNA was 4131 base pairs and included 21 exons. The SCUBE3 gene contained a 2895-base pair open reading frame that encoded a peptide of 965 amino acids. Comparison of the deduced amino acid sequences of porcine SCUBE3 with those of human, mouse, zebrafish, and rat showed 96, 95, 73, and 95% identities, respectively. Porcine SCUBE3 mRNA expression levels were highest in the backfat, bone marrow, and cartilage tissues. Copy number variation was detected in porcine SCUBE3 and validated by real-time quantitative polymerase chain reaction. Different copy number variations were present in randomly selected individuals and may, therefore, be a good marker for identifying phenotypic traits. Our findings provide a basis for further investigation of the functions and regulatory mechanisms of SCUBE3 in pigs.

Mitogen-activated protein kinase kinase kinase 5 (MAP3K5) is essential for apoptosis, proliferation, differentiation, and immune responses, and is a candidate marker for residual feed intake (RFI) in pig. We cloned the full-length cDNA sequence of porcine MAP3K5 by rapid-amplification of cDNA ends. The 5451-bp gene contains a 5'-untranslated region (UTR) (718 bp), a coding region (3738 bp), and a 3'-UTR (995 bp), and encodes a peptide of 1245 amino acids, which shares 97, 99, 97, 93, 91, and 84% sequence identity with cattle, sheep, human, mouse, chicken, and zebrafish MAP3K5, respectively. The deduced MAP3K5 protein sequence contains two conserved domains: a DUF4071 domain and a protein kinase domain. Phylogenetic analysis showed that porcine MAP3K5 forms a separate branch to vicugna and camel MAP3K5. Tissue expression analysis using real-time quantitative polymerase chain reaction (qRT-PCR) revealed that MAP3K5 was expressed in the heart, liver, spleen, lung, kidney, muscle, fat, pancrea, ileum, and stomach tissues. Copy number variation was detected for porcine MAP3K5 and validated by qRT-PCR. Furthermore, a significant increase in average copy number was detected in the low RFI group when compared to the high RFI group in a Duroc pig population. These results provide useful information regarding the influence of MAP3K5 on RFI in pigs.

We investigate the superlensing effect of a two-dimensional (2D) triangular photonic crystal (PC) slab consisting of rectangular air holes in silicon. An analysis of equal-frequency contours (EFCs) shows that geometric parameters of the PC element shape can greatly change the shape of EFCs, thus change the effective phase index of the PC structure. Moreover, an effective negative refractive index n eff = −1 can be obtained at a normalized working frequency of 0.30 × 2 π c / a by adjusting the width of the rectangular air holes. Imaging capacity of this PC slab involving both the power intensity and full width at half-maximum of image is studied by the finite-difference time-domain (FDTD) method. In order to achieve a high-quality image, an appropriate surface termination of the PC slab is chosen. Coupled-mode theory analysis shows that the optimized surface termination can excite two kinds of surface modes which can couple with the Bloch wave in the PC. With the help of these surface modes, both the intensity of image and the super resolution capacity for the PC slab lens can be improved greatly.

In this paper, a two-dimensional Kagome lattice photonic crystal (PC) made of GaAs ( ɛ = 12.96) dielectric rods in air is considered. This Kagome lattice PC has an effective refractive index n eff = −1 at a low normalized frequency ω = 0.187 × 2 πc / a . Imaging quality and the capability of the super-resolution of two point sources are studied for a superlens made of such PC structure. In order to achieve a high quality image and to improve the spatial super-resolution of two sources, a clipping Kagome lattice PC is designed. Results simulated by finite-difference time-domain method show that imaging quality and super-resolution of two sources can be enhanced greatly as the perfect Kagome lattice structure are superseded by the clipping Kagome lattice structure. Coupled-mode theory analysis gives an explanation why the clipping structure is superior to the perfect one for both the imaging quality and the capability of the super-resolution of two sources. This clipping Kagome lattice PC structure would be widely used in optical devices and integrated circuit.

Network manufacturing, with the development of network economy, is advanced manufacturing mode. It’s applied widely. The engine manufacturing process of advanced motor company is studied and analyzed in this paper. The network system of engine manufacturing process is designed, which is based on the platform of .NET and SQL Server database. The network manufacturing of engine is realized. It reduces production cost and improves company’s core competitiveness. Carrying out the system’s parted purview management, it’s safe and credible.

Micro-drills are best suited for small hole machining in view of its low cost and wide applications. The dimensions of micro-drills have a significant influence on the accuracy of the machining results and the life-span of the micro-drills. Hence, micro-drills, be they new or re-sharpened ones, must be inspected prior to use. Because the outer diameter of the micro-drills is small (0.5–0.1 mm), it is not easy for inspection to be done manually. This study employed the Laser Micro Gage (LMG) to measure the outer diameter of micro-drills as well as the degree of run-out and taper. Compared with the results obtained manually, measurements made by this automatic inspection system are faster and more accurate, achieving a precision within 0.1 μm.

We perform full-potential first-principles total energy calculations for several simple and transition metals along three distinct phase transformation paths, i.e. the tetragonal, trigonal and hexagonal paths. Our results show that higher-energy phases, such as the bcc structure for Al, Cu and Ti and the fcc structure for Nb, Mo, Ta and W, are always unstable with respect to one or more of transformation modes. Some local minima along the total energy profiles are found to correspond to the structures not dictated by the symmetry. We discuss the most interesting problem why a higher-energy phase may be stabilized in a pseudomorphic film.

The spin Hall current in a two-dimensional electron system with nonuniform Rashba spin–orbit interaction (SOI) is investigated by means of the lattice Green's function method. Large electric and spin Hall currents are produced by this nonuniform Rashba SOI, while the electric Hall current vanishes in the uniform Rashba SOI system. A nondissipative spin Hall current is also produced, without any longitudinal voltage bias, any external magnetic field and any special class of band insulators.

Nanoparticle magnesium borate with a particle size of about 10 nm was prepared using ethanol supercritical fluid drying technique and was characterized with TEM, XRD and X-ray small angle scattering. Tribological properties of the nanoparticle magnesium borate, using as lubricating oil additive, were evaluated using a four-ball and a block-on-ring tribotester. The wear scar was characterized with SEM and XPS. Results indicate that the wear resistance and load carrying capacity of the 500 SN base oil were improved and the friction coefficient of the oil was decreased by the additive. FeB were formed on sliding surface.

A supercritical carbon dioxide drying technique was developed to prepare nanometer particulate materials. The technique consists of preparation of an aqueous gel, filtering, washing, replacement of the water in the gel with a mixture solvent of n-butanol and ligroin and supercritical carbon dioxide drying. The product was characterized with TEM, XRD and X-ray small-angle scattering. The results indicated that an amorphous aerogel of the beryllium borate was obtained with this technique. The diameter of the product particles was about 7 nm. Isopropyl alcohol supercritical drying was also used to prepare aerogel beryllium borate, where recrystallization took place due to the high critical temperature of isopropanol.

An oil-soluble compound containing ferrous iron and boron–ferrous octoxyborate was synthesized. The antiwear and friction-reducing properties of the compound as a lubricating oil additive were evaluated using a four-ball and a block-on-ring tribotester. Results indicated that both the wear resistance and the load-carrying capacity of a 500 SN base oil were improved and its friction coefficient was decreased by the additive. The wear scar, after being cleaned using an ultrasonic bath in ligroin and in distilled water, was characterized with SEM and XPS. Diboron trioxide, FeB and Fe2B were all found to have been deposited on the wear-scar surface. It was this deposition that provided the oil with excellent antiwear and friction-reducing properties.

The transport property of electron in a quantum ring-stub system is investigated through quantum waveguide theory. The persistent current is produced and controlled by tuning the length of the stub even in the absence of the magnetic field, and it can be observed if one tuning the Fermi energy near the antiresonance or the Fano resonance of the transport current.

The first-principles discrete variational method is employed to study the effect of boron and phosphorus impurities on the electronic structure of the NiΣ11(113)/[110] grain boundary. The calculated results show that boron slightly decreases the bonding between the host Ni atoms but, on the other hand, it forms a strong bonding state with its Ni neighbours. Phosphorus strongly decreases the bonding between the host Ni atoms. The calculated environment-sensitive embedding energies show that boron has a strong site-competition ability and can successfully drive out phosphorus from the grain boundary region.

The first-principles discrete variational method is employed to study the effect of boron and sulphur on the electronic structure of the Ni Σ11(1 1 3 )/[1 1 0] grain boundary (GB). The calculated results show that boron does not strongly influence (only slightly decreases) the bonding between the atoms of the metal. In addition, B forms the strong bonding state with its neighbouring metal atoms. Our study also indicates that S strongly decreases the bonding between the atoms of the metal, and that the bonding tendency between S and the atoms of the metal across the GB plane is very weak. The calculations of environment-sensitive embedding energies show B has the strong site-competition ability and can successfully drive out S from the GB region. We conclude that the influence of impurities segregating on the GBs is closely associated with their effects on: (i) the decrease of the bonding between the atoms of the metal due to the presence of impurities; (ii) the bonding between the impurity atom and the atoms of the metal; and (iii) the site-competition ability of impurity atoms.

The northwestern part of the Jiaodong Peninsula, or the Zhao-Ye Gold Belt, contains the largest lode-gold deposits in China, which are spatially related to several suites of intrusive granitoids. Previous attempts to provide constraints on the timing of gold mineralization and its tectonic setting, through studies of the granitoids, have led to conflicting data, dependant on the isotopic methodology used, and resultant genetic and tectonic models for their setting are equivocal. SHRIMP U–Pb studies of complexly zoned zircons of the Linglong, Luanjiahe and Guojialing granitoid suites suggest that the Jiaodong Peninsula is underlain by Precambrian basement with components up to 3.4 Ga old. Inherited zircons of early Mesozoic age indicate that this basement was reworked at 250–200 Ma, probably during a collisional orogeny involving the North China Craton and South China Craton. The Linglong, Luanjiahe and Guojialing suites were derived from this early Mesozoic basement between 165 and 125 Ma, and were probably emplaced as post-collisional granitoids, the latest intrusions (at 125 Ma) coinciding broadly with superplume activity or a major plume breakout event in the Palaeo-Pacific Plate. Importantly, if lode-gold mineralization is essentially a single event, as indicated by similar hosting structures and deposit characteristics, it can be dated between about 126 Ma, the age of the youngest granitoid cut by gold-bearing quartz veins, and 120 Ma, the age of one of a swarm of post-mineralization feldspar-porphyry dykes. Thus, as in most other metallogenic provinces which host so-called mesothermal lode-gold deposits, gold mineralization was late in the orogenic cycle, probably late- or post-accretion, and closely followed the emplacement of the latest major plutonic phase in the development of a series of anomalously voluminous granitoid batholiths.

C-myb and c-ets-1 have variously been demonstrated to function as protooncogenes. Using a human leukemic cell line, ML-1, we have examined the mechanism by which these genes participate in establishing the sustained proliferation mode that is characteristic of the transformed cell. In the absence of serum, ML-1 cells were found to require IGF-1 and transferrin (TF) for growth and TGF-beta or TNF-alpha plus TF for differentiation. Upon administration of the growth factors, c-myb expression increased within 60 min, whereas after addition of the differentiation factors c-myb expression ceased completely within 3 hr. A correlation was found to exist between the level of c-ets-1 protein in the cells, the extent to which that protein is bound to intron I of the myb gene and the amount of c-myb mRNA that is expressed. Upon administration of growth factors, a sizable increase in the intracellular, and particularly, in the intranuclear level of c-ets-1 protein was observed, whereas a pronounced decrease in the level of this protein occurred after exposure to the differentiation factors. These data demonstrated that the level at which an oncogene-specified transcription factor is expressed can affect the expression of other target oncogenes involved in the regulation of cell proliferation. Stimulated expression of such transcription factor can then lead to the continuous proliferation cycle characteristic of the cancer cell.

Experiments have been designed and performed to determine the effects on the seeding efficiency of injection seed energy and power, alignment, and spatial mode matching between single longitudinal mode seed lasers and a power oscillator. The absorption features of H/sub 2/O have allowed the characterization of the seeding efficiency by selectively absorbing the laser output energy corresponding to the seed wavelength. This enabled the accurate measurement of the residual unseeded laser output energy. Both a pulsed and a continuous wave seed source were used for these experiments. This work compares the results of the experiments with a theory for injection seeding developed in the previous paper. >

Thin films YBa 2 Cu 3 O 7− x (YBCO) were grown epitaxially on MgO(100) and LaAlO 3 (102), respectively, by pulsed KrF excimer laser ablation. The c -axis of YBCO films was found to be perfectly perpendicular to the plane of substrates used. Combined measurements of X-ray pole-figures and Laue diffraction patterns show that two sets of orientation relationships exist between the a − b plane of YBCO films and both substrates. For the MgO(100) substrate, the a -axis of YBCO films is parallel to either the [001] or [011] directions of the substrate. The latter is more preferential, possibly due to less mismatch between YBCO(300) and MgO(220). In the case of the LaAlO 3 (102) substrate, the a -axis of the YBCO films is aligned either in the [010] or in the [221] direction of the substrate. A small lattice mismatch of 0.3% favors the latter case.

Nowadays, one of the trends in microelectronic packaging is to integrate multi-functional systems into one package, resulting in more applications of highly dissimilar materials in the form of laminated thin films or composite structures. As a consequence, the number of interfaces increases. Often, the interface between these dissimilar materials is where the failure is most likely to occur especially when the packaged devices are subjected to the thermo-mechanical loading. Prediction of interface delamination is typically done using the critical energy release rate. However, the critical value is dependent on mode mixity. This paper describes our efforts on interface characterization as a function of mode mixity. A new test setup is designed for mixed mode bending testing. It allows for measuring the stable crack growth as the function of mode mixity. The crack length, necessary for calculation of the energy release rate is measured by means of an optical microscope. Finite element simulation is used to interpret the experimental results and thus to establish the critical energy release rates and mode mixities.

Interfacial delamination is a common cause of failure in microelectronic packages. Characterization and prediction of interface behavior in manufacturing, testing and application conditions is demanded in order to reduce development times and costs of IC packages. In the design processes of microelectronics, possible interface delamination is evaluated by the critical energy release rate to detach the materials. This critical energy release rate can be obtained experimentally using various approaches. However, its measurement is complicated due to the fact that adhesion strength is not only temperature and moisture dependent but also stress state (mode mixity [1]) dependent. This paper describes our efforts on interface characterization as a function of mode dependency. A new test setup is designed and built. It allows transferring two separated loads on a single specimen. The test methodology that is developed in this paper is also able to evaluate the interfacial fracture toughness as function of temperature and moisture. The crack length, necessary for calculation of the energy release rate is measured by means of an optical microscope. Finite element simulation is used to interpret the experimental results and thus to establish the critical energy release rates and mode mixities.

The acceptable flexibility and stretchability for ultra-thin substrate would be reached by embedding the ultra-thin substrate into the flexible polyimide/silica rubber and patterning the poly-silicon or silicon into square/hexagon segmentations. The segments interconnect by metal wires for the signal communication, different wire shapes are designed to reach more flexible. In this contribution, results of FE optimization on mechanical reliability issues of interconnect in-between segments on ultra-thin polyimide/silica rubber substrates are presented. Generation of cracks within the silicon and dielectric layers is then studied under controlled bending (glass cylinders with diameters of 2 - 10 mm, compressive and tensile stress) using specially for this purpose designed bending tools. Specimen observation is done using an optical microscope with possibility of digital recording and evaluation by pattern recognition software. The results show that the cracks appear first in the dielectric layers in-between the silicon layer segments and only at higher loads propagate or are generated within the silicon itself. The development of first cracks depends significantly on the silicon layer segmentation size which affects both the crack density and the crack width. The crack density increases sharply with the strain for early stage and then increases slightly. The crack width increases steadily. The high flexibility result can be reached that no crack be detected under the bending tests with 2 mm diameters by optimizing segment size and gap. Multilevel FEM simulations are performed in order to increase understanding of the major failure processes and optimizing the interconnect geometry. Results of simulations and experiments compare quite well. Second generation samples are designed with consideration of interconnect in-between segments and avoid of silicon dioxide in-between segments.

Nowadays, one of the trends of microelectronic packaging is to integrate multiple functional systems into one package, resulting in more applications of multi-materials in the form of laminated thin films or stacks. As a consequence, the number of interfaces increases. This causes tremendous mechanical problems, for instance interfacial delamination. Prediction of interface delamination is typically done using the critical energy release rate. However, interface strength is highly dependent on mode mixity. A new test setup is designed for mixed mode bending testing. It allows for measuring the stable crack growth as the function of mode mixity. The crack length, necessary for calculation of the energy release rate is measured by optical microscope and evaluated by pattern recognition software. Comparing finite element result with critical energy release rate, it could be predicted whether and when the crack at the interface will propagate. The mode mixity is determined through combining experimental data with FEM simulation data.