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The responses of material properties to multi-field stimulation are often exploited to construct new types of multi-functional devices. Here, we demonstrate electrical, optical and thermal modulation of the electronic properties of optothermal ferroelectric field-effect transistors (FeFETs) which are fabricated by growing Bi

How to use modern information technology to efficiently and quickly obtain the personalized recommendation information required by students, and to provide high-quality intelligent services for schools, parents and students has become one of the hot issues in college research. This paper uses FP-growth association rule mining algorithm to infer student behavior and then use the collaborative filtering recommendation method to push information according to the inference result, and then push real-time and effective personalized information for students. The experimental results show that an improved FP-growth algorithm is proposed based on the classification of students. The algorithm combines the student behavior inference method of FP-growth algorithm with the collaborative filtering hybrid recommendation method, which not only solves the FP-tree tree branch. Excessive and collaborative filtering recommendation algorithm data sparseness problem, can also analyze different students' behaviors and activities, and accurately push real-time, accurate and effective personalized information for students, to promote smart campus and information intelligence The development provides better service.

Along with the rapid development of Internet technology, GNSS technology and mobile terminals, a large amount of information including geographical location and time attributes has been generated. Faced with large and complex Internet geospatial data, how to quickly and accurately extract valuable reference information becomes an urgent problem to be solved. And the user's demand for personalized information of recommendation information is getting stronger and stronger, and researching efficient and accurate personalized recommendation system has good application value. In this paper, based on the application requirements of personalized recommendation information, the GIS platform and related recommendation algorithms are used to fully exploit the user and location based on geographic space-time big dataIt is divided into user explicit interest and user implicit interest, and then establishes a scientific and efficient user behavior motivation prediction model based on geographic situation. User interest information can be obtained from explicit interest information, implicit interest information and geographic situation interest information. Geographical environment, geographic location and other related context information. By introducing time factors, it is used to update and improve the user real-time interest model to achieve accurate prediction of user behavior motives under geographic spatio-temporal big data. Use Apriori algorithm to calculate the support and determine the current Frequent itemsets of user interest in geographic context, using frequent itemsets to generate strong association rules, and realizing the analysis of user behavior motives based on geography context. For geographic spatio-temporal big data, this paper proposes a personalized hybrid recommendation algorithm, which is based on users. Effective combination of collaborative filtering algorithms and association rules for geographic context-user behavioral interest adaptation.

Starting from the object-oriented idea, this paper analyses the existing event-based models and the logical relationship between behavioral cognition and events, and discusses the continuity of behavioral cognition on the time axis from the perspective of temporal and spatial cognition. A geospatial data model based on behavioral-event is proposed. The physical structure and logical structure of the model are mainly designed, and the four-dimensional model of “time, space, attribute and event” is constructed on the axis. The organic combination of the four models can well describe the internal mechanism and rules of geographical objects. The expression of data model based on behavior-event not only elaborates the basic information of geospatial objects, but also records the changes of related events caused by the changes of geographic Entities' behavior, and expresses the relationship between spatial and temporal objects before and after the changes of behavior cognition. This paper also designs an effective method to organize spatio-temporal data, so as to realize the effective management and analysis of spatio-temporal data and meet the requirements of storage, processing and mining of large spatio-temporal data.

The distribution of urban functional space is an important factor to measure the development of a city. Its reasonable layout plays an important role in the development of urban economy and the optimization of urban spatial pattern. This paper is based on the third ring road of Nanning city Based on POI data, the functional land is divided into five categories: life service, business and finance, public service, leisure and entertainment, and residence. By using kernel density analysis, frequency density analysis and standard deviation ellipse analysis, the urban function and distribution characteristics of the Third Ring Road area in Nanning city are identified and analyzed. The results show that: 1. The overall spatial layout is affected by traffic and urban master plan Under the influence of other factors, the spatial pattern of “circle layer” appears. Taking one ring as the core, it has obvious central agglomeration. 2. The trend of urban development shows an obvious pattern of prosperity in the West and decline in the East.

To investigate the protective effect of recombinant adult serine protease inhibitor fromA total of 18 male BALB/c mice were randomly divided into the sham-operation group, the model group, and theAt 12 h following CLP, there were significant differences in the serum levels of ALT (

This study aims to explore the expression pattern and clinical significance of circ_001680 in gastric carcinoma (GC) process.Circ_001680 levels in 40 pairs of GC and paracancerous ones were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between circ_001680 and GC clinicopathological parameters was analyzed. AGS and SGC-7901 cells were used for constructing circ_001680 knockdown models by shRNA transfection. Proliferative and metastatic abilities in GC cells with circ_001680 knockdown were examined by cell counting kit-8 (CCK-8) and transwell assay, respectively. Dual-Luciferase reporter assay was conducted to clarify the interaction between circ_001680 and MAP2. Their co-regulation on GC process was detected through rescue experiments.Circ_001680 was highly expressed in GC tissues and cell lines. High level of circ_001680 predicted high incidences of lymphatic and distant metastasis, and poor prognosis in GC patients. Knockdown of circ_001680 suppressed proliferative and metastatic abilities in AGS and SGC-7901 cells. MAP2 was the target gene binding circ_001680, which was lowly expressed in GC. In addition, MAP2 was negatively correlated to circ_001680. Knockdown of MAP2 could abolish the suppressed proliferative and metastatic abilities in GC cells with circ_001680 knockdown.Circ_001680 is highly expressed in GC tissues and closely related to metastasis and prognosis in GC patients, which promotes the proliferative and metastatic abilities in GC cells by negatively interacting with MAP2.

The fast-ion transport during neutral beam injection on the Experimental Advanced Superconducting Tokamak (EAST) is studied. Based on the NUBEAM and TRANSP codes, it is found that fast-ion transport is anomalous when the minimum safety factor (qmin) is about 2, while it is neoclassical when qmin is around 1. Neutral beam injection heating efficiency, plasma stored energy, and the total heating power are reduced when the fast ion transport is anomalous. The Alfven continuum spectrum and the mode structures of toroidal Alfven eigenmodes (AEs) are also calculated for comparison between neoclassical fast-ion transport and anomalous fast-ion transport. High-qmin discharge with anomalous fast-ion transport has more AE activity than that of lower qmin discharge with neoclassical fast-ion transport.

Through data on the balance of payments, this article examines the performance of the crawling peg system in China’s foreign exchange markets. We are interested in whether the exchange rates are st...

The study was designed to investigate the JAK2/STAT3 signaling pathway in pancreatitis and its association with inflammation and cell death to provide a potential treatment method for pancreatitis.The rat pancreatic acinar AR42J cells were used for the study, and they were transfected with JAK2 and STAT3 siRNAs to mimic knockdown condition. Cerulein was used to treat AR42J cells. Western blot and ELISA were employed to detect the expression of related proteins. Flow cytometry was done to analysis the necrosis of AR42J cells.In this study, we found that cell death and the secretion of IL-6 and TGF-β1 were significantly increased, and the JAK2/STAT3 signaling pathway was activated in cerulein-induced AP. To determine the role of JAK2 and STAT3, JAK2 siRNA and STAT3 siRNA were used to block JAK2 and STAT3, respectively. The levels of IL-6 and TGF-β1 levels in the medium were lower in JAK2 siRNA and STAT3 siRNA-treated cells compared with controls. Flow cytometry analysis showed that the level of cell death, expression of cleaved caspase-3, and the release of LDH were decreased following JAK2 siRNA and STAT3 siRNA treatment.These findings point to a novel role for the JAK2/STAT3 signaling pathway in the progression of cerulein-induced AP.

In order to study the correlation between the annual dynamic change characteristics of vegetation and climatic factors in Haihe River Basin in recent 14 years. The MODIS / NDVI data from 2003 to 2016 were used to extract the vegetation coverage of the Haihe River Basin. driver of NDVI changes in the Haihe River basin. The one-dimensional linear regression was used to analyze the trend of temporal changes of vegetation in the Haihe River Basin, and the trend analysis and correlation analysis of vegetation climate change were performed by combining the data of precipitation and temperature meteorological data from 2003-2016 in the Haihe River Basin. The study shows that the overall vegetation cover in the Haihe River basin is relatively high, and the cover type is mainly high, and the NDVI increases significantly at the rate of 0.021/10a; the spatial vegetation change trend in the Haihe River basin is mainly improvement, accounting for 94% of the basin area; climatic factor correlation analysis shows that precipitation is the main factor influencing the change of NDVI in the Haihe River basin.

Considering initial axial loads, dynamics and stability of an inner functionally graded cylindrical shell conveying swirling fluid (i.e., water) in the annulus between the flexible inner shell and the identical rigid outer shell are investigated by the traveling wave approach. Shell motions are described by Donnell’s thin shell equations. The fluid forces associated with shell motions are treated in the frame of the potential flow theory. The theoretical analysis is conducted by the zero-level contour method. The critical velocities of losing stability are determined. The influences of angular flow on the critical axial velocity and axial flow on the critical annular velocity are studied. Moreover, effects of the magnitude and the direction of initial axial loads on the critical velocities are fully discussed.

MYC locus rearrangements-often complex combinations of translocations, insertions, deletions and inversions-in multiple myeloma (MM) were thought to be a late progression event, which often did not involve immunoglobulin genes. Yet, germinal center activation of MYC expression has been reported to cause progression to MM in an MGUS (monoclonal gammopathy of undetermined significance)-prone mouse strain. Although previously detected in 16% of MM, we find MYC rearrangements in nearly 50% of MM, including smoldering MM, and they are heterogeneous in some cases. Rearrangements reposition MYC near a limited number of genes associated with conventional enhancers, but mostly with super-enhancers (e.g., IGH, IGL, IGK, NSMCE2, TXNDC5, FAM46C, FOXO3, IGJ, PRDM1). MYC rearrangements are associated with a significant increase of MYC expression that is monoallelic, but MM tumors lacking a rearrangement have biallelic MYC expression at significantly higher levels than in MGUS. We also have shown that germinal center activation of MYC does not cause MM in a mouse strain that rarely develops spontaneous MGUS. It appears that increased MYC expression at the MGUS/MM transition usually is biallelic, but sometimes can be monoallelic if there is an MYC rearrangement. Our data suggest that MYC rearrangements, regardless of when they occur during MM pathogenesis, provide one event that contributes to tumor autonomy.

We report on the crystal growth, structural and spectroscopic investigation of a novel trigonal calcium vanadate crystal, Tm3+:Ca9La(VO4)7. Polarized absorption, stimulatedemission and gain cross-section spectra are determined for this material. The maximum ¿SE corresponding to the 3F4 ¿ 3H6 transition amounts to 1.28 × 10-20 cm2 at 1854 nm for ¿- polarization. The measured lifetime of the Tm3+ ions in the 3F4 state is 1.19 ms. The Judd- Ofelt analysis performed yielded intensity parameters of ¿2 = 4.682, ¿4 = 0.659 and ¿6 = 0.475 [10-20 cm2]. The polarized Raman spectra indicate a strong and broad band centered at 867 cm-1. Owing to the disordered nature of Ca9La(VO4)7, the Tm3+ ions exhibit a broad and smooth gain profile at ~2 ¿m. The spectroscopic properties of Tm3+:Ca9La(VO4)7 are very promising for broadly tunable and ultrashort pulse lasers near 2 ¿m.

Many complex networks exhibit a scale-free, power-law distribution of vertex degrees. This common feature is a consequence of two generic mechanisms relating to the formation of real networks: (i) networks tend to expand over time through the addition of new vertices and (ii) new vertices attach preferentially to those that are already well connected. We show that for many natural or man-made complex networks possessing a scale-free power-law distribution with the exponent γ ≥ 2, the number of degree-1 vertices, when nonzero, is of the same order as the network size N and that the average degree is of order at most log N. Our results expose another necessary characteristic of such networks. Furthermore, our method has the benefit of relying only on conditions that are static and easily verified for arbitrary networks. We use the preceding results to derive a closed-form formula approximating the distance distribution in scale-free networks. Such distributions are applied extensively in the fields of computer communication and software architecture, among other domains.

We investigated single nucleotide polymorphisms (SNP) at 87 sites of the phosphodiesterase 4D (PDE4D) gene in Mongol and Han patients with ischemic stroke in Inner Mongolia. SNPs in 226 patients with ischemic stroke (case group, 110 Mongol patients, 116 Han patients) and 220 patients without neurological disease (control group, 102 Mongol patients, 118 Han patients) were detected by polymerase chain reaction-restriction fragment length polymorphism and gene sequencing. The genotype and allele frequencies of all groups were compared. There were no statistically significant differences in genotypes in the PDE4D gene at 87 sites between the case and control groups (P > 0.05). The C allele frequency in the case group was significantly higher than that in the control group (P < 0.05). The CC genotype and C allele frequencies in the Mongol case subgroup were higher than those in the Mongol control subgroup (P < 0.05). The CC genotype and C allele frequencies in the Han case subgroup were higher than those in the Han control subgroup (P < 0.05). In the case group, there were no significant differences at 87 sites for genotypes and allele frequencies between the Mongol and Han subgroups. In the control group, there were no significant differences at 87 site genotypes and allele frequencies between the Mongol and Han subgroups. The increase in the C allele frequency at 87 SNP sites in PDE4D may increase ischemic stroke risk. We found no differences in the risk between Mongol and Han populations in Inner Mongolia.

A control strategy to harness the torque ripple of a hybrid stepping motor at low speeds for precision profile tracking is proposed. The strategy uses a model-based control design that controls the phase current based on the direct quadrature transformation of the second-order nonlinear dynamics. An identification procedure based on a least-squares algorithm is applied to estimate the model parameters for calculation of the ripple dynamics. The method produces a more appropriate form of linear regression which avoids the problem of reconstructing important signals such as the rotor speed and the derivatives of the driving current, and rejects additional errors created by the quantisation of the measurements. This paves the way for an integrative process to obtain precise trajectory tracking by combining a reference trajectory, traditional PID control, and dynamic feedback linearising control coupled with feedforward compensation over a broad torque-ripple frequency band. Simulations and experiments are performed with a typical hybrid stepping motor to test its profile tracking accuracy. The results may be used to develop a commercial control scheme for tuning computer-controlled drives.

We have prepared a variety of high molecular weight, thermally stable, blue-light-emitting random copolymers of 9,9-di-n-hexylfluorene by nickel(0)-mediated polymerization. The copolymers are readily soluble and easily processable from organic solvents. Both the polymer and electronic properties may be tuned by selection of comonomer structure. The electronic properties also vary with composition and film morphology. A blue-light-emitting device has been prepared using ionic salts for electrochemical doping.

Nickel and silicon powders, of average composition Ni3Si, were mechanical alloyed in a high energy ball mill. The severe plastic deformation produced by mechanical milling induced transformations with increasing milling time as follows: mixture of elemental Ni and Si powder → f.c.c. solid solution → nanocrystalline f.c.c. The structural evolution with milling time was followed by X-ray diffraction, differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). Complete f.c.c. solid solution occurred at a milling time of 4 h and the saturated ΔH (by DSC) peak in the range of estimated enthalpy even after 24 h milling. The similarity of the mechanism of structural development by mechanical alloying of the Ni76Si24 powder mixture, and by mechanical milling of Ni76Si24 compound was also investigated in this study.

Restriction fragment length polymorphism analyses of polymerase chain reaction (PCR) amplified DNA were used to distinguish Diaporthe phaseolorum and Phomopsis longicolla isolates from other soybean fungal pathogens. Primers made to the conserved sequences of nuclear ribosomal DNA amplified the internal transcribed spacer (ITS) regions of D. phaseolorum var. meridionalis and P. longicolla. The PCR products were cloned and then sequenced. Specific-primers, Phom.I and Phom.II, were designed from the polymorphic regions of D. phaseolorum and P. longicolla isolates from soybean to distinguish them from other soybean fungal pathogens. These ITS-derived primers amplified a 337-bp-specific DNA fragment from P. longicolla, D. phaseolorum var. meridionalis, D. phaseolorum var. caulivora, D. phaseolorum var. sojae, and Phomopsis spp. from 20 different hosts. No amplified product was observed using DNA of seven other soybean fungal pathogens or soybean DNA. The detection limit of PCR using primers Phom.I and Phom.II was 2.5 × 10-7 dilution of fungal DNA extracted from samples of 10 pooled seeds and as low as a 1:15 (Phomopsis:soybean) ratio when using 10 ng of DNA per μl from each P. longicolla and soybean. PCR did not produce products using primers Phom.I and Phom.II with DNA extracted from noninfected seeds, but specific bands were observed from samples of 10 pooled seeds and from individually infected seeds. A specific band was observed as well from DNA extracts of tissue samples from symptomless plants inoculated with P. longicolla and D. phaseolorum var. sojae.

Emergence of novel second-order phase transitions by sums of multifractals was found by Radons and Stoop.1,2 Using the same method as Radons and Stoop but different support, we have found that the second-order phase transitions are suppressed.3 In this paper, we continue to extend the method to three multifractals, with the effect of the sums of the three multifractals being the sums of two identical multifractals and those of two different multifractals combined together. We have found that the resulted phase diagrams are more complicated, with second-order phase transitions either partially or completely suppressed.

In this paper, the phase behavior of a naturally occurring reservoir fluid mixture has been experimentally studied in the near-critical region. The computer-controlled ROP (France) high-pressure PVT system equipped with video camera-monitor-recorder system and an on-line Anton-Paar fluid density meter was used in the experimental work. The measurements involve the compressibility factor of the compressed fluid, the bubble/dew point locus in the near-critical region, the mixture critical point, the liquid volume fraction in the two-phase region, and the density of the liquid/vapor phase. The volume-translated Soave-Redlich-Kwong equation of state proposed by Peneloux and Rauzy (1982) [Peneloux, A. and Rauzy, E., 1982. A consistent correction for Redlich-Kwong-Soave volumes. Fluid Phase Equilibria, 8: 7–23] was selected to test its performance in the near-critical region. The C 7 + -fraction of the reservoir fluid was characterized by the procedure proposed by Pedersen et al. (1984) [Pedersen, K.S., Thomassen, P. and Fredenslund, Aa., 1984. Thermodynamics of petroleum mixtures containing heavy hydrocarbons. 1. Phase envelope calculations using Soave-Redlich-Kwong equation of state. Ind. Eng. Chem., Process. Des. Dev., 23: 163–170].

The interfacial reactions between thin films of cobalt and silicon and (100)-oriented GaAs substrates in two configurations, Co/Si/GaAs and Si/Co/GaAs, were studied using a variety of techniques including Auger electron spectroscopy, x-ray diffraction, and transmission electron microscopy. The annealing conditions were 200, 300, 400, 600-degrees-C for 30 min, and rapid thermal annealing for 15 s. It was found that Si layer in the Co/Si/GaAs system acts as a barrier at the interface between Co and GaAs when annealed up to 600-degrees-C. The interfacial reaction between Co and Si is faster than that between Co and GaAs in the system of Si/Co/GaAs. The sequence of compound formation for the two metallizations studied (Co/Si/GaAs and Si/Co/GaAs) depends strongly on the sample configuration as well as the layer thickness of Si and Co (Co/Si atomic ratio). From our results, it is promising to utilize Co/Si/GaAs multilayer film structure to make a CoSi2/GaAs contact, and this CoSi2 may offer an alternative to the commonly used W silicides as improved gate metallurgies in self-aligned metal-semiconductor field effect transistor (MESFET) technologies.

This chapter reviews the important fungal and nematode diseases of lentil and their management. The important foliar diseases include Ascochyta blight, rust, Botrytis grey mould, anthracnose, Stemphylium blight and powdery mildew, and important soilborne diseases are Fusarium wilt, Sclerotinia stem rot and nematode diseases.

By comparing the quantum efficiencies of light emission in a series of poly[2-methoxy-5(2′ethyl)hexoxy-phenylenevinylene] diodes with calcium cathodes and various anode metals, we show that, in all cases electrons are the majority carrier and recombination is limited by hole injection. These conclusions are confirmed by the examination of a second series of samples in which alkanethiol barrier layers of varying thickness, are deposited on a gold anode. The highest external quantum efficiency was achieved in these experiments using a clean, semitransparent gold anode. We suggest that electron and hole injection rates play the primary role in determining current balance and that mobilities play a minor role.

Damage and recovery induced by electron and ion beam irradiation during AES analysis of silicon nitride and oxynitrides are discussed. The results show that after prolonged electron beam irradiation, a damage peak is induced in the Si LVV spectrum. The initial incubation time decreases for higher electron current densities and for higher O/N rations. The electron beam-induced damage is irreversible. The silicon nitride and oxynitrides are very susceptible to damage by energetic ion impact. However, this damage is reversible: the surface can be recovered by irradiation with an electron beam in the ultra-high vacuum system when the electron current density is kept low. The damage recovery is related to the irradiation time, the current density and the beam energy, as well as to the preparation method of the layers. The degree of damage and recovery are characterized by the fraction of ‘covalent’ silicon and silicon nitride obtained from factor analysis of the Si LVV spectrum. The mechanism of the damage and recovery will be discussed.

Quantitative Auger electron spectroscopy analysis for the ternary system InGa1-xAs grown by molecular-beam epitaxy has been studied. The relative sensitivity factors are determined by with an internal reference element. The matrix correction factor for In relative to Ga was shown to be 1.08. No preferential sputtering of As for the ternary compounds was found, and the sputter correction factor, K(s)InGa is 0.75. The results are compared with that measured by the x-ray double-crystal diffraction analysis, electron probe microanalysis, and Auger analysis without matrix and sputter corrections.

An experimental 8mm-wave multi-functional transmission system has been set up for the transmission of color TV, telephony, and data in a bi-directional manner. In this paper, the design and performance of this system is presented with regard to detailed system considerations and description. A series of measurements and experiments have been carried out to measure the practical transmission performance, and to observe the transmission quality. At a given bit error rate, the deterioration of signal-to-noise ratio in a nonlinear band-limited channel have been predicted with a MSK modulation. The link availability of this system at different data rates are given in reference to the rainfall distribution of Hong Kong. The experimental results show that the transmission range > 1km for TV signal under clear-air conditions, transmit-receive isolation > 50dB, low bit error rate at a serial data communication, and high quality of TV programs transmission can be observed.

A numerical approach based on the 3D finite-difference method and the analytical results of the fields in waveguides is developed for the analysis of the characteristics of waveguide three-port junctions. The basic two wave equations described by two transverse field components with respect to the direction of the power propagation are derived from the Maxwell Equations in cylindrical coordinates. For the junctions filled with air, there is only one field component in each equation, and generally solving the equation relative to electric field is enough for the obtain of the property of the junction. Two typical cases were analyzed by the approach and the results agree well with the earlier experimental and theoretical results.

An experimental transmission system at 8mm-wave was built up to perform a multi-channel transmission of audio and video signals in frequency reuse, due to space separation and polarization isolation. The features of such an 8mm-wave communication systems is described in details with respect to system construction and performance. Based on carrier-to- noise ratio and the signal level available, the attenuation margin and link availability are evaluated in terms of path length and specific rainfall distribution at Hong Kong. The quality of the demodulated video and audio signals is used for the analysis of co-channel interference and multipath effects. The experiment results show that the polarization isolation is more than 18.5dB, space isolation is more than 24.1dB, and a good quality in transmission of TV programs is observed in frequency reuse situation under a uncritical condition. Finally, a simplified scheme of the application of this system in wharf container dispatching and management is proposed.

The growing demands in local area networks (LANs) for low cost broad band data communications are providing a major opportunity for further technology developments important to polymer optical materials and devices. Polymer optical fibers (POF) can satisfy requirements for high-bandwidth, quick-connect, fiber optics for short distance (100 m) data transmission in data links, multimedia, and multi-noded bus networks[1-4]. Figure 1 illustrates the variety of application areas together with their required transmission bandwidths.

The G gamma:A gamma ratios of Hb F were determined in 331 newborn babies of the Man ethnic group in Liaoning Province, P.R. China, using polyacrylamide gel electrophoresis; in 27 cases they were also determined by reversed phase high performance liquid chromatography. The results showed that a high G gamma value (80%) was present in four cases (1.21%) and low G gamma values (30-48%) in six cases (1.81%); not a single case with the A gamma T [A gamma 75(E19)Ile-Thr] chain was found. Gene mapping analysis demonstrated that two babies with high G gamma values had the -G gamma-G gamma-/-G gamma-A gamma- (0.60%), and two others the -G gamma-AG gamma-A gamma-/-G gamma-A gamma- (0.60%) arrangements. Two of the four babies with low G gamma values were identified as -A gamma-A gamma-/-G gamma-A gamma- (0.60%) and the other two as -GA gamma-/-G gamma-A gamma- (0.60%). The genotype -A gamma-A gamma- has not been reported before in Chinese.

A new class of high thermal stability fused-ring guest chromophores intended for incorporation into highly stable host polyimides has been successfully developed. Thermal stabilities far in excess of 300°C have been achieved for both the pure guest and the guest-host polyimide systems. The Microscopic second order nonlinear optical properties of the guest chromophores have been characterized both theoretically and experimentally. The achievement of the new high temperature EO chromorphores and polyimide formulations have directly resulted in the discovery of new EO device designs and architectures.

The local environment of Er3+ in heavily Er-doped (Er, 2.5 at. %) Si nanoclusters embedded in SiO2 films annealed at various temperatures was investigated by using the fluorescence-extended x-ray absorption fine structure spectroscopy. The results show that annealing caused a large effect on the local environment of Er3+ surrounded by O atoms and the 1.54 mu m photoluminescence intensity. The correlation between the local environment around Er3+ and the corresponding 1.54 mu m photoluminescence was discussed. (c) 2006 American Institute of Physics.

Hall, current-voltage, and deep-level transient spectroscopy measurements were used to characterize the electrical properties of metalorganic chemical vapor deposition grown undoped, Er- and Pr-implanted GaN films. Only one deep level located at 0.270 eV below the conduction band was found in the as-grown GaN films. However, four defect levels located at 0.300, 0.188, 0.600, and 0.410 eV below the conduction band were found in the Er-implanted GaN films after annealing at 900 degrees C for 30 min, and four defect levels located at 0.280, 0.190, 0.610, and 0.390 eV below the conduction band were found in the Pr-implanted GaN films after annealing at 1050 degrees C for 30 min. The origins of the deep defect levels are discussed. (C) 2005 American Institute of Physics.

The possibilities for quantitative Auger analysis in the derivative mode of Ti and Co silicide films are examined as a function of the composition. Both matrix and sputter corrections are taken into account. It is shown that the theoretical expressions for both corrections predict a weak composition dependence. However, the quantitative results obtained with this procedure strongly deviate from Rutherford backscattering spectroscopy and X-ray diffraction measurements. It is concluded that the sputter and matrix corrections cannot sucessfully be applied for these materials. Experimental matrix and sputter correction factors are determined.

Quantitative Auger electron spectroscopy analysis is performed for the ternary system AlxGa1 - xAs with different x-values. Thick layers and superstructures are grown by molecular beam epitaxy. The relative sensitivity factors are determined by the method of the internal reference element. Correction for preferential sputtering of Ga is accounted for by a correction factor determined relative to electron probe microanalysis measurements. The matrix corrections are unimportant for this system. The results will be compared with photoluminescence measurements.

The interaction of Ti with Si and SiO2 is studied by means of Auger and X-ray photoelectron spectroscopy. The “peak-to-peak-minus-3-eV-height” method is used for the quantification with AES, while XPS is mainly used to characterize the oxide and nitride states. It will be shown that AES can successfully be applied for quantitative analysis of the resulting TiNx/TiOx/TiSix multilayers in the oxygen lean cases, while a small artifactal nitrogen signal occurs otherwise.

A major extratropical cyclone developed over the East China Sea during the initial phase of the AMTEX'75. Using cross-section analyses the dynamic structure of the cyclone is investigated with an emphasis on obtaining a better understanding of the physical mechanisms controlling the development and maintenance of this intense oceanic system. The dynamic and kinematic variables examined include ageostrophic acceleration, potential and absolute vorticity, and vertical and horizontal motions. During the 24-h period following 1200 UTC 14 February, the surface cyclone moved eastward more than 22° longitude, while the upper-level trough propagated only about 15°. In the same period, the central pressure at the surface dropped more than 20 mb while the areas extent of the closed circulation showed little change. Vertical decoupling of the wave-cyclone system is suggested by this discrepancy in phase speed, and by the temporal evolution of the trough axis and the height fields during the lust 12 h. Laten...