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The effect of CaF2–4LiF (1–5 mol.-%) on the phase structure, microstructure and dielectric properties of 0·9BaTiO3–0·1BiScO3 (0·9BT–0·1BS) ceramics has been investigated. The 0·9BT– 0·1BS with CaF2–4LiF dopant ceramics sintered at 1100°C show a pure perovskite structure. Results show that CaF2–4LiF dopant can improve the sintering ability of 0·9BT–0·1BS ceramics when CaF2–4LiF content is below 3 mol.-%. The ceramics with 3 mol.-%(CaF2–4LiF) sintered at 1100°C exhibit a high permittivity, low dielectric loss as well as flat ϵ′ v. temperature curve indicating a favourable temperature stability, which are listed as follows: ϵ′25 °C=1483, tan δ 25 °C=0·00309, Δϵ′/ϵ′25 °C ≤ ± 13% at 100 kHz, in the temperature range from –55 to 150°C. This low sintering temperature allows using relatively inexpensive internal electrodes in the production of future capacitors.

For complex systems that experience Multiple Dependent Competing Failure Processes (MDCFP), the dependency among the failure processes presents challenging issues in reliability modeling. This article, develops reliability models and preventive maintenance policies for systems subject to MDCFP. Specifically, two dependent/correlated failure processes are considered: soft failures caused jointly by continuous smooth degradation and additional abrupt degradation damage due to a shock process and catastrophic failures caused by an abrupt and sudden stress from the same shock process. A general reliability model is developed based on degradation and random shock modeling (i.e., extreme and cumulative shock models), which is then extended to a specific model for a linear degradation path and normally distributed shock load sizes and damage sizes. A preventive maintenance policy using periodic inspection is also developed by minimizing the average long-run maintenance cost rate. The developed reliability and maintenance models are demonstrated for a micro-electro-mechanical systems application example. These models can also be applied directly or customized for other complex systems that experience multiple dependent competing failure processes.

Atherosclerosis is considered as a chronic inflammatory response in arterial blood vessels. The function of osteopontin (OPN), a proinflammatory cytokine, in the Ang II-induced inflammatory activation in vascular smooth muscle cells (VSMCs) remains poorly understood.In the present study, the role of OPN was investigated by knocking down OPN using small interfering RNA (siRNA). VSMCs from human saphenous vein were divided into three groups according to RNAi treatment: OPN siRNA group, sham (un-transfected) treated group, and control siRNA group. RNAi effect was investigated by real time PCR, western blotting analysis and ELISA. Then all groups were stimulated with Ang II. The inflammatory activation was assessed by determining the activation of NFkappaB and activator protein-1 (AP-1), and the release of interleukin-6 (IL-6) and IL-1beta.OPN was knocked down effectively in OPN RNAi group. Inflammatory activations, such as NFkappaB and AP-1 activation and IL-6 accumulation, were induced by Ang II in sham treated group and control siRNA group. However, it was abolished in OPN siRNA group by the downregulation of OPN compared to sham treated group and control siRNA group.This result suggested that OPN plays an important role in Ang II-induced inflammatory activation in VSMCs. The finding further supports OPN as a potential target for atherosclerotic therapy.

Global dimming is currently an active area of research in climate change. Trends of temporal (on the order of decades, years, seasons or even months) and spatial patterns in sunshine hours and associated climatic factors (average air temperature, relative humidity, precipitation and wind speed) over North China are evaluated for the period 1965~1999 based on data from 81 standard meteorological stations. The results show that: (1) North China is experiencing decreasing sunshine hours (–82.855 h/decade); (2) seasonally, decline in sunshine hours is highest in summer and lowest in winter; (3) spatially, decrease in sunshine hours is highest in inland and plain regions and lowest in the northwest mountain and coastland regions; (4) sunshine hours have a high correlation with precipitation, relative humidity and wind speed, with wind speed having the strongest influence on sunshine hours implicit in the close correlation (temporally and spatially) between the two variables; (5) cloud cover could not be any significant driver of sunshine-hour decline because it is more or less stable; (6) spatially and seasonally, wind speed is an important driving factor of decreasing sunshine hours in North China. Furthermore, the interactions between wind speed and aerosol loading may be an enabling factor of wind speed in driving (strongly) the changes in sunshine hours.

We have studied the enhancement of radiative emission rate of CdSe/ZnS core-shell quantum dots on semi-continuous gold films which have been prepared by using sputtering technique. The photoluminescence intensity and the decay rate of CdSe/ZnS quantum dots are affected by the semi-continuous gold films. Both the photoluminescence intensity and the decay rate of the quantum dots are greatly enhanced by the semi-continuous gold films near the conductive percolation threshold and that are caused by the enhanced local electric field due to the surface plasmon resonance on the semi-continuous gold films.

In design of conventional bridges the gap between bridge spans is usually only a few centimetres. For such an expansion joint poundings between adjacent bridge girders during strong earthquake shaking are usually unavoidable. Pounding often causes damages to girders. In extreme situations it may push one of the bridge decks off the support. In this work a new design philosophy using a modular expansion joint (MEJ) is introduced. So far MEJs have been used mainly to cope with large thermal expansion and contraction of long bridges. For proper design of bridges to avoid the consequence of poundings under strong earthquakes not only a minimum total gap but also the maximum opening movement of the joint are essential. In this study the simultaneous effect of varying vibration properties of adjacent bridge spans, spatially varying ground excitations and soil-structure interaction on the total closing and opening movements of a MEJ, required to eliminate possible pounding and to ensure the join in perfect working order, is estimated, and the main influence factors are discussed.

Two series of Au–TiO2 composite films with Au percola- tion threshold qC of 0.34 and 0.82 were prepared by using sputtering technique at the pressure of 5.0 × 10–2 and 8.0 × 10–2 Torr, respectively. As qC increases from 0.34 to 0.82, the plasmon resonant absorption of the composite films near qC shifts from about 700 nm to 760 nm, and the maximal second harmonic generation (SHG) intensity increases by 20%, the maximal nonlinear absorption coefficient increases from –3.0 × 104 cm/GW to 1.7 × 105 cm/GW, and the maximal nonlinear refraction index increases from a very small value to –2.6 cm2/GW. The large second- and third-order optical nonlinearity of the Au–TiO2 composite films with high qC is attributed to the high density of Au particle in the nonconductive film and the strong local field enhancement caused by the surface plasmon resonant absorption. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Soil organic matter (SOM), microbial carbon (Cmic), and microbial nitrogen (Nmic) status affected by the application of inorganic fertilizer and organic amendments in subtropical paddy soils were investigated. Soil samples were collected from the plow layer of three long-term (17 years) field experiments at Xinhua, Ningxiang, and Taojiang counties in Hunan Province, China. Results showed that, compared to the control, application of inorganic fertilizer alone showed no significant effect on soil organic C (SOC), total N (Ntot), Cmic and Nmic. The application of inorganic fertilizer along with manure or straw significantly increased SOC and Ntot and soil Cmic and Nmic contents for all three sites, while following an application of inorganic fertilizer along with straw only for two sites. Cmic and Nmic were closely correlated with SOC and Ntot, respectively. In conclusion, application of inorganic fertilizer along with manure or straw is an effective way of enhancing SOM and microbial biomass in subtropical paddy soils.

Estradiol (E2) acts through the estrogen receptor (ER) to downregulate many genes, and tamoxifen (Tam) largely reverses this repression but the underlying mechanisms are unclear. Repression of the folate receptor (FR)-alpha P4 core promoter by ER is enhanced by E2 and reversed by Tam. This effect was unaffected by inhibition of new protein synthesis and required the E/F and the DNA-binding domains of ER without direct binding of ER to DNA. The repression by E2/ER was not specific for either Sp1 or TATA elements but was loosely selective for the initiator and flanking sequence. Insertion of a response element or a relatively strong Sp1 cluster to recruit ER upstream of the core promoters caused a switch to activation by E2/ER that was inhibited by Tam. In nuclear extracts, association of ER with a biotinylated core promoter fragment was promoted by E2 but Tam blocked this effect. Repression/de-repression of the P4 promoter and endogenous FR-alpha expression by E2/Tam required SMRT and/or NCoR. ER associated with the chromosomal P4 promoter and SMRT and NCoR associated with it in an ER-dependent manner; these associations were favored by E2 but disrupted by Tam, in the short term, without changes in ER expression. TAFII30 was required for optimal P4 promoter activity and for the repressive association of ER. E2 may thus maintain a low transcriptional status of genes by favoring direct TAFII30-dependent association of ER with the core promoter in a co-repressor complex containing SMRT and/or NCoR; this repression is overridden in target genes containing an upstream element that strongly recruits ER. In addition to suppressing the activation of classical E2 target genes, Tam may upregulate genes by passively dissociating the ER co-repressor complex.

SrTiO3 films are fabricated on DyScO3 substrates by pulse laser deposition. In situ X-ray diffraction (XRD) is used to characterize the thermal expansion coefficient at low temperature. The abnormal behavior in lattice parameter at 80 K may be the hint of a phase transition. High resolution XRD is performed to detect the two kinds of dislocations, i.e. screw and edge. Results show that the density of edge dislocation is a little larger than that of the screw one. The total dislocation density has the order of about 108 cm-2. Edge dislocation density decreases with the increase of the film thickness. We argue that the ratio between these two dislocation densities results in the growth mode of the film.

The frequency tuning can be achieved by integrating SrTiO3 (STO) thin films into high-temperature superconducting YBa2Cu3Oy (YBCO) devices and tuning the dielectric constant of the STO films by an electrical bias. We have fabricated epitaxial STO thin films on superconducting YBCO. By the combination of various surface characterizations such as scanning probe microscope, structural and dielectric measurements, we attempted to understand the fundamental mechanisms of dielectric properties in STO thin films. Substrate surface and structural properties of the heterostructure were studied. We have measured the temperature dependence of dielectric constant and loss tangent of STO thin films. The system exhibits 41% dielectric constant tuning over a bias of 4 V at low temperature.

This study evaluated the feasibility and effectiveness of using the bispectral index (BIS) to monitor anesthetic depth in patients with severe burns receiving intravenous target-controlled infusion (TCI) of remifentanil and propofol. We randomly assigned 80 patients undergoing elective escharectomy (

Cu pumping is a potential reliability issue for through silicon via (TSV) based 2.5D and 3D integration, due to the CTE mismatch between silicon and copper. In this paper, we report the reliability assessment of Cu pumping treated at different annealing conditions. Cu pumping is simulated by finite element method to compare the effect of the overburden layer. The pumping of TSVs having a diameter of 10 μm and a depth of 100 μm has been fabricated and characterized using a white light optical profiler. According to the thermal budget evaluation and TC, HTS and HAST test results, higher annealing temperature is beneficial to control the Cu pumping and improve the TSV reliability.

The ancient silk road of China passed through Xinjiang and facilitated gene exchanges from the East and the West which impacted on the genetic variation and structure of the nomadic Kazakh population residing there. In order to understand the nature of this genetic variation; 151 Xinjiang Kazakh samples were obtained from four main Kazakh groups and were analyzed using mtDNA and Y-chromosome markers. The Xinjiang Kazakh population is heterogeneous, showing the coexistence of matrilineal lineages with different origins. No genetic differentiation of mtDNA is observed among the four different regional Xinjiang Kazakh populations in Xinjiang by AMOVA and Networks. The genetic diversity of Y-STR loci is higher in Xinjiang Kazakhs (0.968 ± 0.014) than the Kazakhs from Kazakhstan (0.629 ± 0.071) and Russia (0.835 ± 0.020). East Eurasians make a more than 50% contribution to the maternal and paternal lineages of Xinjiang Kazakhs. There is more gene flow from West Eurasian into the maternal lineages of Xinjiang Kazakh than to the Kazakhs from Russia and Kazakhstan. Moreover, mtDNA and Y-STR displayed high polymorphism in Xinjiang Kazakhs (the haplotype diversity and power of discrimination were 0.990 ± 0.003, 0.9137 for mtDNA HVS and 0.968 ± 0.014, 0.9489 for Y-STR system, respectively), suggesting they would be very useful and important markers for forensic analysis and population genetic studies.

This paper presents results of a parametric study of seismic induced lateral-torsional-pounding responses of an asymmetric and a symmetric one-storey system subjected to bi-directional ground motion. The properties of the symmetric model are fixed, while the vibration frequency and eccentricity of the asymmetric model vary in the numerical computation. 20 sets of bi-directional horizontal earthquake ground motion time histories are numerically simulated for the analysis. All the simulated motions are compatible individually with the Newmark-Hall design response spectrum with 5% damping and normalized to 0.5g. Ensemble mean peak responses of the two systems to the 20 sets ground motions are estimated. Both linear elastic and nonlinear inelastic behaviours are studied. Effects of torsional stiffness, structural vibration frequency, eccentricities, and initial gap between two structures are investigated. Numerical results are presented in dimensionless form and compared with the code torsional provisions. In this paper, the input ground motion time histories at all the structural supports are assumed to be uniform. An accompany paper of this study is devoted to discuss the effect of the spatially varying ground motion on coupled lateral-torsional-pounding responses of the adjacent structures (Hao and Gong 2005).

A mathematical model of the direct chill (DC) casting process for magnesium billets has been developed to predict the temperature in the billet, dummy block, and center pin using the commercial finite-element (FE) package, ABAQUS. Boundary conditions used for primary and secondary cooling and interfacial cooling between the billet and dummy block were defined based on the literature and knowledge of the physical phenomena occurring during the process. Temperatures in the billet, mold, and dummy block, as well as sump depth, were measured for a series of casting conditions during a plant trial conducted at Timminco Metals. The data obtained during the plant trial were used to “fine-tune” and validate the model for a variety of industrial casting conditions.

The catalytic incineration of dimethyl sulfide and dimethyl disulfide in a MnO/Fe(2)O(3) fixed bed catalytic reactor was studied. This paper provides information on the affect of the operating parameters that included: inlet temperature, space velocity, VOC concentration and O(2) concentration. The results show that the conversion of VOCs increases as the inlet temperature increases and the space velocity decreases. The higher the concentration of VOCs, the lower their conversions. The O(2) concentration has no affect on the conversion of VOCs. VOCs have poisoning affects on the MnO/Fe(2)O(3) catalyst, especially at lower temperatures.

In this paper, the displacement boundary value problem of a piezoelectric material plane with an elliptic hole is studied. As the permittivity of the medium in the hole is far less than that of the piezoelectric material, the electric induction of the medium is negligible. An exact solution is obtained. Its application to the inclusion problem has been given. The components of the stress tensor are discussed.

A new type of polyester polyol dispersion with good storage stability was prepared based on a hydrophilic monomer 5-sodium sulfodimethyl isophthalate (5-SIPM), and frequently-used monomers such as neopentyl glycol (NPG), dimethyl terephthalate (DMT), dimethyl phthalate (DMP) and trimethylolpropane (TMP) by the transpolycondensation and polycondensation method. The polyester polyol dispersion was characterized by FTIR and GPC. The proper content of these monomers were determined by the performance of polyester dispersion: the content of TMP was 15wt%, the content of NPG was 7.5wt% and the hydrophilic monomer 5-SIPM content was 5wt%. Two-component waterborne polyurethane (2K-WPU) coatings were prepared by Bayhydur® XP2487/1 and polyester polyol dispersions, which were stored before and after at 40 ° for 6 weeks, the prepared films have no differences in drying time, adhesion, pencil hardness, gloss and chemical resistance, the result also reveals that the polyester polyol dispersion have excellent storage stability resistance.

To observe the changes of expression of aquaporin-1（AQP-1） and AQP-4 in drowned and postmortem immersed rats' lungs.Thirty healthy male Wistar rats were randomly divided into drowning group, postmortem immersion group and cervical dislocation group. The morphological changes of rats' lungs were observed using HE staining. The mRNA and protein expressions of AQP-1 and AQP-4 in rats' lungs were detected by real-time PCR, immunohistochemistry and Western blotting, respectively.The results of immunohistochemistry and the Western blotting showed that the protein expression of AQP-1 of the drowning group was higher than the postmortem immersion group and the cervical dislocation group （The increase of mRNA and protein expressions of AQP-1 and AQP-4 in lungs of rats with cute lung injury of the drowning group would be useful for differentiating vital drowning from postmortem immersion.

Radiotherapy has the widest application to esophageal squamous cell carcinoma (ESCC) patients. Factors associated with DNA damage repair have been shown to function in cell radiosensitivity. Human positive cofactor 4 (PC4) has a role in nonhomologous end joining (NHEJ) and is involved in DNA damage repair. However, the clinical significance and biological role of PC4 in cancer progression and cancer cellular responses to chemoradiotherapy (CRT) remain largely unknown. The aim of the present study was to investigate the potential roles of PC4 in the radiosensitivity of ESCC. In this study, we showed that knockdown of PC4 substantially increased ESCC cell sensitivity to ionizing radiation (IR) both in vitro and in vivo and enhanced radiation-induced apoptosis and mitotic catastrophe (MC). Importantly, we demonstrated that silencing of PC4 suppressed NHEJ by downregulating the expression of XLF in ESCC cells, whereas reconstituting the expression of XLF protein in the PC4-knockdown ESCC cells restored NHEJ activity and radioresistance. Moreover, high expression of PC4 positively correlated with ESCC resistance to CRT and was an independent predictor for short disease-specific survival of ESCC patients in both of our cohorts. These findings suggest that PC4 protects ESCC cells from IR-induced death by enhancing the NHEJ-promoting activity of XLF and could be used as a novel radiosensitivity predictor and a promising therapeutic target for ESCCs.

Single phase AlN nanowires are fabricated by a sublimation method. They were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), typical selected area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM). The SEM and TEM images show that most of the nanowires have diameters of about 10–60 nm. The crystal structure of AlN nanowires revealed by XRD, SAED and HRTEM shows the AlN nanowires have a wurtzite structure.

Eosinophils have been shown to increase in tissues during many fibrotic conditions and consequently have been suggested to contribute to the development of fibrosis. This study tested the hypothesis that eosinophils are essential in the development of lung fibrosis in mice in response to bleomycin (BLM). Anti-IL-5 antibody was administered intraperitoneally into mice 2 h prior to endotracheal BLM inoculation and thereafter, every other day. Lung eosinophilia was evaluated by measurement of eosinophil peroxidase activity and confirmed by eosinophil counts in histologic sections. Lung fibrosis was evaluated by hydroxyproline content and confirmed by collagen staining in histological sections. Results demonstrated that BLM induced pronounced lung eosinophilia, which was maximal 7 days after BLM treatment and remained elevated through day 14, in C57Bl/6 SCID mice and CBA/J mice. In contrast, eosinophilia was a minor component in the lungs of wildtype C57Bl/6 mice after BLM treatment, although lung fibrosis developed similarly in all three strains of mice. Treatment with anti-IL-5 completely abrogated eosinophilia but failed to block pulmonary fibrosis induced by BLM in all mouse strains, including C57Bl/6 SCID, wildtype C57Bl/6 mice, and CBA/J mice. Analysis of cytokine mRNA by RNase-protection assay in C57Bl/6 SCID mice indicated that BLM treatment caused enhanced expression of the cytokines, TNF-α, and IL-6 at days 3, 7, and 14 post-BLM inoculation, regardless of whether eosinophils were depleted by anti-IL-5. Finally, the importance of eosinophils in lung fibrosis was examined in IL-5 gene knockout mice (IL-5tm1Kopf). BLM treatment induced significant lung fibrosis in IL-5 knockout mice in the absence of eosinophilia. These findings indicate that eosinophils are not an absolute requirement for BLM-induced pulmonary fibrosis in the mouse.

Abstract: The performance of the gaseous fuel supply and its influence on hydrocarbon (HC) emissions of dual-fuel engines have been investigated. A new design of manifold respirators with mixers is also presented in the paper. The design of the gaseous fuel supply system has a great influence on HC emissions in the dual-fuel engine at light load. The problem of scavenging is discussed and solved by using the manifold respirators in the dual-fuel engine. It performs the function of retarding the gaseous fuel entry timing from the moment of intake valve opening, and its delaying effects have been measured and tested. Experimental results show that the manifold respirator gives the best performance in reducing HC emissions compared with a common pipe mixer and a respirator with no mixer. In addition, the mixing effects are sensitive to the mixer configurations.

Microwave assisted molten salt synthesis (MAMSS) method was employed to synthesised Bi4Ti3O12 (BTO). The MAMSS can produce the anisotropic BTO grains at 600°C for 30 min. The increase in temperature and soaking time can make a plate-like grain of BTO more distinct. There are not obvious changes of the particles size when the salt content continues to increase. The anisotropy of the grain produced by NaCl–KCl chlorate is much more distinctive than that by Na2SO4–K2SO4 sulphate.

Calcitonin gene-related peptide (CGRP) causes vasorelaxation in rat aorta involving endothelium/nitric oxide (NO)-dependent elevations of both cAMP and cGMP levels. When endothelium is removed, preincubation with exogenous NO uncovers and potentiates direct (endothelium-independent) cAMP elevations and vasorelaxations caused by CGRP. This enhancing effect of NO potentially involves elevation of cGMP and inhibition of Type III (cGMPinhibitable) phosphodiesterase, causing accumulation of cAMP. However, NO may have other actions. The aim of the present study was to determine if brain natriuretic peptide (BNP), which elevates cGMP levels independent of NO, could enhance cAMP accumulations and vasorelaxations induced by CGRP in rat aortic rings denuded of endothelium. When added separately, neither CGRP (100 nM) nor BNP (10 nM) altered cAMP levels. When added in combination, CGRP (100 nM) and BNP (10 nM) significantly elevated cAMP levels (from control of 0.95 ± 0.08 to 1.53 ± 0.09 pmol/mg protein) at 2 min. BNP (10 nM) elevated cGMP levels 10-fold at 2 min and this response was not altered by co-administration of CGRP (100 nM). Pretreatment with BNP at concentrations as low as 1 nM in endothelium-denuded aortic rings greatly enhanced the direct vasorelaxant effects of CGRP (100 nM) (from control of 0% to 57.6 ± 6.8% relaxation of phenylephrineprecontractions). Our findings indicate that BNP enhances direct (endothelium-independent) cAMP elevations and vasorelaxations caused by CGRP in rat aorta, thus supporting the concept that cGMP inhibits cAMP metabolism and enhances CGRP-induced responses in aortic smooth muscle cells.

Void shape changes induced by electromigration pose reliability problems in Al-based interconnects. Recent observations have shown that a rounded void sometimes collapses to a transverse slit in an interconnect with bamboo-like grain structure. This article provides a linear stability analysis for a circular void that is only partially conductive in an otherwise infinite conductive medium. The relation between the inner conductivity (i.e., the conductivity of the medium in the void) and the critical remote electric field intensity, Ecr, for the linear stability of the void is established. It is proven that when the inner conductivity becomes zero, Ecr goes to infinity, and we can look upon the inner conductivity of a vacuum void as zero. That is why the vacuum circular void is linearly stable. It is also shown that when the inner conductivity is very small, the stability of a void is sensitive to it. From the computational results, we know that if the inner conductivity is 0.1% of that outside the void, t...

A large number of artifacts (stone tools) have been discovered in Baise (Bose), Guangxi, China in recent years. They show that ancient man were living in the south of China during very ancient times. During excavation, tektites were discovered in the same layer of deposits as the stone tools. The structure of the layers of deposits in this site was never disturbed, which is the evidence that the stone tools were left behind by the ancient man at the time when the tektites fell on the earth, which were slowly covered over by layers of deposits. Fission track dating has been carried out on tektites. The age of the tektites is 0.732 ± 0.039 Ma, which is also the age of the ancient man in Baise, Guangxi, China. The annealing degree of spontaneous fission tracks in the tektite was investigated by measuring track diameters. A correction of age for track fading has been made by track diameter technique. According to current understanding, tektites were formed by the impact of falling asteroids or comets on the earth's surface. The dating shows that a big impact occurred on the earth 0.732 Ma ago. The coincidence of the age of the tektites with the age of geomagnetic polarity reversal (∼ 0.73 Ma) from the Matuyama Epoch to the Brunhes Epoch proposes a plausible explanation that the possible cause of the geomagnetic polarity reversal is due to the big impact of space objects falling onto the earth. The result of the dating also set up a standard for inferring the ages of the deposits in South China as well as in South-East Asia where laterite (red soil) deposits exist in the entire region.

Bubble damage detectors have been prepared by using polyacrylamide as detector solid and freon as detector liquid. Tests show that the prepared detectors are sensitive to fast neutrons and have proportionality between bubble number and neutron fluence within a certain range of neutron fluence. Therefore, it can be used as a fast neutron detector and a dosimeter. Our experiments also show that the sensitivity of the detector increases with temperature.

We report an anomalous Zn surface diffusion in InP during annealing of ohmic contact structures containing Zn. A Pd/Zn/Pd contact was used to demonstrate this phenomenon. Electrical properties of the contact were monitored to corroborate this anomalous surface diffusion. Cross-sectional scanning electron microscopy was also used to delineate the Zn diffusion front lines. It was found that the Zn surface lateral diffusion can extend ≥50 µm for samples annealed at 500°C or higher temperatures. Close attention should be paid to this anomalous lateral surface diffusion during fabrication of devices using Zn-contained ohmic contacts.

Si/Pd‐based contact schemes based on the solid‐phase regrowth (SPR) process have been developed to form low‐resistance ohmic contacts to n‐Al0.5In0.5P (Eg=2.3 eV) with a minimum contact resistivity of about 6×10−6 Ω cm2. The SPR process responsible for the ohmic contact formation was verified using cross‐sectional transmission electron microscopy. The contact resistivity of the Si/Pd‐based contacts remained in the range of 2–3×10−5 Ω cm2 after aging at 400 °C for 25 h. Furthermore, a lateral modulation disordering phenomenon as a result of the SPR process in the regrown AlInP layer has been observed. These ohmic contacts may be useful in some novel Al0.5In0.5P‐related device fabrication schemes.

An on‐chip aluminum interconnect carries an intense electric current at an elevated temperature, motivating atoms to diffuse in the solid state, and inducing voids that may cause an open failure. Recent observations have shown that a void sometimes collapses to a slit running nearly perpendicular to the electric current direction. Such a slit often lies inside a grain rather than along a grain boundary. An earlier calculation showed that diffusion on the void surface, driven by the electric current, can cause a circular void to translate in an infinite, isotropic interconnect. It was suggested recently that this solution may be unstable, and that two forces compete in determining the void stability: surface tension favors a rounded void, and the electric current favors a slit. A linear perturbation analysis, surprisingly, revealed that the translating circular void is stable against infinitesimal shape perturbation. Consequently, the slit instability must have resulted from finite imperfections. This article reviews the experimental and theoretical findings, and describes a numerical simulation of finite void shape change. We determine the electric field by a conformal mapping of complex variables, and update the void shape for a time step by a variational method. The simulation shows that a finite void shape imperfection or surface tension anisotropy can cause a void to collapse to a slit.

Background All the current treatments of Parkinson’s disease can’t prevent the development of the disease. DBS is effective to improve the symptoms of Parkinson’s disease, but whether it can slow down the disease progression is still unclear. Casepresentation Here we report a case of a Parkinson’s disease with 27 years of disease course. He got the disease when he was 56 years old, and he could not walk in the 15th year after onset. After the DBS treatment, the patient’s symptoms improved, and he could look after himself in daily life. Because of scalp infection, in the 22nd year of the course of disease, DBS was taken out, but the symptoms of the patient are still better than those before DBS implanting for several years. He is alive till now. Conclusion This patient’s survival period is much longer than the general PD patients. DBS treatment may be the main reason for the delayed progression of disease and extended survival period. We speculate it may be associated with long-term DBS implantation which caused neural network remodeling and nerve protection.

We theoretically investigate the quantum Hall effect in a graphene superlattice (GS) system, in which the two valleys of graphene are coupled together. In the presence of a perpendicular magnetic field, an ordinary quantum Hall effect is found with the sequence . At the zeroth Hall platform, a valley-chiral Hall state stemming from the single K or valley is found and it is localized only on one sample boundary contributing to the longitudinal conductance but not to the Hall conductivity. Our findings may shed light on the graphene-based valleytronics applications.

Using the wide multi-band photometry available in the COSMOS field we explore the host galaxy properties of a large sample of Active Galactic Nuclei (AGN) obtained by combining X-ray and optical spectroscopic selections. Based on a careful study of their Spectral Energy Distribution (SED), which has been parametrized using a 2-component (AGN+galaxy) model fit, we derived dust-corrected rest-frame magnitudes, colors, stellar masses and star formation rates (SFRs). We find that AGN hosts span a large range of stellar masses and SFRs. No color-bimodality is seen at any redshift in the AGN hosts, which are found to be mainly massive, red galaxies. Once accounting for the color-mass degeneracy in well defined mass-matched samples, we find a residual marginal enhancement of AGN incidence in redder galaxies with lower specific star formation rates, and we argue that this result might emerge because of our ability to properly account for AGN light contamination and dust extinction. Interestingly, we find that the probability for a galaxy to host a black hole growing at any given "specific accretion rate" (i.e. the ratio of X-ray luminosity to the host stellar mass) is almost independent of the host galaxy mass, while it decreases as a power-law with Lx/M. By analyzing the normalization of such probability distribution, we show how the incidence of AGN increases with redshift as rapidly as (1+z)^4, in close resemblance with the overall evolution of the specific star formation rate of the entire galaxy population. Although AGN activity and star formation in galaxies do appear to have a common triggering mechanism, at least in a statistical sense, within the COSMOS sample we do not find strong evidence of any 'smoking gun' signaling powerful AGN influence on the star-forming properties of their hosts galaxies.

We report the observation of weak magnetism in superlattices of LaAlO3/SrTiO3 using beta-detected nuclear magnetic resonance. The spin lattice relaxation rate of Li-8 in superlattices with a spacer layers of 8 and 6 unit cells of LaAlO3 exhibits a strong peak near similar to 35 K, whereas no such peak is observed in a superlattice with spacer layer thickness of 3 unit cells. We attribute the observed temperature dependence to slowing down of weakly coupled electronic moments at the LaAlO3/SrTiO3 interface. These results show that the magnetism at the interface depends strongly on the thickness of the spacer layer, and that a minimal thickness of similar to 4-6 unit cells is required for the appearance of magnetism. A simple model is used to determine that the observed relaxation is due to small fluctuating moments (similar to 0.002 mu(B)) in the two samples with a larger LaAlO3 spacer thickness. DOI: 10.1103/PhysRevLett.109.257207