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Electrochemical aptamer (EA) sensors based on aptamer-cDNA duplex probes (cDNA: complementary DNA) and target induced strand displacement (TISD) recognition are sensitive, selective and capable of detecting a wide variety of target analytes. While substantial research efforts have focused on engineering of new signaling mechanisms for the improvement of sensor sensitivity, little attention was paid to the enhancement of sensor response rate. Typically, the previous TISD based EA sensors exhibited relatively long response times larger than 30min, which mainly resulted from the suboptimal aptamer-cDNA probe structure in which most of aptamer bases were paired to the cDNA bases. In an effort to improve the response rate of this type of sensors, we report here the rational engineering of a quickly responsive and sensitive aptamer-cDNA probe by employing the conception of bivalent interaction in supramolecular chemistry. We design a bivalent cDNA strand through linking two short monovalent cDNA sequences, and it is simultaneously hybridized to two electrode-immobilized aptamer probes to form a bivalent binding (BB) aptamer-cDNA probe. This class of BB probe possesses the advantages of less aptamer bases paired to the cDNA bases for quick response rate and good structural stability for high sensor sensitivity. By use of the rationally designed BB aptamer-cDNA probe, a TISD based EA sensor against ATP with significantly enhanced response rate (with a displacement equilibrium time of 4min) and high sensitivity was successfully constructed. We believe that our BB probe conception will help guide future designs and applications of TISD based EA sensors.

The Li

We present a theoretical prediction of a highly efficient membrane for hydrogen purification and natural gas upgrading, i.e. laminar MoS

The lithium-sulfur battery, which offers a high energy density and is environmental friendly, is a promising next generation of rechargeable energy storage system. However, despite these attractive attributes, the commercialization of lithium-sulfur battery is primarily hindered by the parasitic reactions between the Li metal anode and dissolved polysulfide species from the cathode during the cycling process. Herein, we synthesize the sulfur-rich carbon polysulfide polymer and demonstrate that it is a promising cathode material for high performance lithium-sulfur battery. The electrochemical studies reveal that the carbon polysulfide polymer exhibits superb reversibility and cycle stability. This is due to that the well-designed structure of the carbon polysulfide polymer has several advantages, especially, the strong chemical interaction between sulfur and the carbon framework (C-S bonds) inhibits the shuttle effect and the π electrons of the carbon polysulfide compound enhance the transfer of electrons and Li+. Furthermore, as-prepared carbon polysulfide polymer-graphene hybrid cathode achieves outstanding cycle stability and relatively high capacity. This work highlights the potential promise of the carbon polysulfide polymer as the cathode material for high performance lithium-sulfur battery.

Background and aims Growing evidence suggests that microRNA plays an essential role in the development and metastasis of many tumors, including gastric cancer (GC). Expression of microRNA-203 (miR-203) has been reported to decrease in GC. In addition, overexpression of miR-203 inhibits grow of GC cells in vitro and in vivo. However, whether miR-203 affects cell migration and invasion of GC remains unclear. This study aimed to reveal the role of miR-203 on migration and invasion of GC, and its potential mechanisms. Methods Synthetic pre-miR-203 (miR-203), anti-miR-203 and scrambled negative control RNAs was transfected into the gastric cancer SGC7901 cells to generate miR-203 or anti-miR-203-transfected stable clones. The roles of miR-203 on cell invasion and motility were then analyzed by Transwell migration assay and Wound healing assay in vitro. Using siRNA to targeting ERK1/2, Slug, and E-cadherin or Slug cDNA transfection (to increase Slug expression) to examine the miR-203 signaling pathway. We also examined the efficacies of miR-203 or anti-miR-203 on peritoneal metastasis of SGC7901 cells in the nude mouse model. Results Overexpression of miR-203 inhibits SGC7901 cell invasion and motility, followed by decreased phospho-ERK1/2 (pERK1/2) and Slug expression, as well as increased E-cadherin expression. Re-expression of Slug in miR-203/SGC7901cells decreased E-cadherin expression and restored the invasive phenotypes. Targeting E-cadherin in miR-203/SGC7901cells also restored the invasive phenotypes. Inhibition of miR-203 promotes SGC7901 cell invasion and motility, followed by increased phospho-ERK1/2 (pERK1/2) and Slug expression, as well as decreased E-cadherin expression. Targeting ERK1/2 or Slug in anti-miR-203/SGC7901cells increased E-cadherin expression and reversed the invasive phenotypes. In addition, targeting ERK1/2 decreased Slug and increased the E-cadherin expression. Significantly, we found that miR-203 could exert marked inhibition of the peritoneal metastasis of SGC7901 in nude mice in vivo. Targeting miR-203 could exert marked promotion of the peritoneal metastasis of SGC7901 in nude mice in vivo. Conclusions miR-203/ERK1/2/Slug/E-cadherin signaling pathway plays an essential role on SGC7901 cell invasion and motility. miR-203 can be novel modalities to prevent peritoneal metastasis of invasive cancers such as gastric cancer.

A rod-like Cu

Based on a polyphenylene network, a series of porous graphene nanotubes (PGNTs) are created and optimised via density functional theory calculations. The calculated band dispersion of the two-dimensional porous graphene can be tuned by rolling it into nanotube form. To explore the energy application of PGNTs, we studied H2 adsorptions on metal (Li, Ca, and Na) decorated structures of PGNTs as well as B-substituted PGNTs. The results indicate that both the curvature effect and B substitution can strengthen the metal binding and prevent the metal atoms from clustering. Particularly for H2 adsorption, modification of the electronic property by the curvature effect is beneficial to provide more accessible space, leading to much higher adsorption energies of H2 on PGNTs than that on planar porous graphene, which is promising for the practical application of hydrogen storage. Copyright © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

High-order harmonic generation from the asymmetric molecular ion HeH2+ exposed to intense laser fields was investigated by quantum wave packet calculations in which the initial wave packet of HeH2+ was prepared in the first excited 2 p σ state. The calculated molecular harmonic plateau at low frequencies was effectively isolated and enhanced by adjusting the carrier-envelope phase (CEP) of the laser field. Furthermore, double-well model, time-dependent electronic density, electronic state population, and time-frequency analyses were presented to explain the underlying mechanism of the efficient isolated molecular plateau. By taking advantage of the CEP effect to control the electronic dynamics, this isolated molecular plateau can be used to generate high-intensity single attosecond pulses.

To find appropriate hydrogen storage materials, Na-decorated H4,4,4-graphyne has been investigated by combing a density functional theory (DFT) and grand canonical Monte Carlo simulations (GCMC). From DFT, we find that the most priority adsorption site for Na atom is the acetylenic ring center of the H4,4,4-graphyne. The Na atoms are adsorbed on two sides of the acetylenic ring named 4Na-decorated H4,4,4-graphyne, with the average binding energy of 2.33 eV. With H2 molecules are introduced into the surface of 4Na-decorated H4,4,4-graphyne continuously, it is found that up to 9 H2 molecules are adsorbed around each Na atom and the adsorbed H2 molecules are split into two layers with the average hydrogen adsorption energy of 0.12 eV/H2, corresponding to a huge gravimetric density of 16.03 wt%. From GCMC simulations, the gravimetric H2 uptake of Na-decorated H4,4,4-graphyne reaches to the maximum value of 16.97 wt% at 77 K and 100 bar which echoes the results attained by DFT. So, our findings suggest that the Na-decorated H4,4,4-graphyne can be a high-capacity hydrogen storage medium.

We investigate a novel 2D carbon allotrope (net-Y) as anode material candidate for Na-ion battery based on density function theory (DFT) calculation. Na-decorated net-Y exhibits good metallic properties with moderate average open circuit voltage of 0.44 V and diffusion barrier of 0.35 eV. Moreover, the calculated maximum Na storage capacity can get to 1787 mAh/g. Furthermore, the first principles molecular dynamics (MD) were performed to demonstrate the thermostability of the Na-ion battery in the near room temperature. Net-Y can be a potential anode material in Na ion battery field with large capacity, low diffusion energy barrier and good thermostability.

Biomimetic gama-alumina was prepared by using broadleaf Liriope leaf as template. The surface acidity of the sample was measured and the adsorption experiments were carried out. The results indicated that the obtained gama-alumina inherited the morphology and microstructure of leaf template and showed weak surface acidity. Therefore, the as-prepared alumina exhibited good adsorption performance for acid fuchsin, but bad adsorption toward alkaline methyl orange. After acid-modifying, the sample showed strong surface acidity and displayed good adsorption performance toward alkaline methyl orange. These results demonstrated that the surface acidity-alkalinity of alumina determined its adsorption performance and selectivity for organic compounds.

Two 3-O-ethyl-3-O-propyl celluloses of similar ethyl and propyl content prepared under different conditions were analyzed with respect to their substituent distribution in the glucosyl units and along the polymer chain by ESI-MS analysis of labeled oligosaccharides. Both samples showed similar regioselectivity of substitution and random distribution of ethyl and propyl groups over the 3-O-positions. The distribution of all types of glucosyl residues identified by monomer analysis was also random over the cellulose molecules. Comparison of the substitution pattern in the glucosyl units with the pattern expected for the observed regioselectivity showed relative high 2-O-alkylation in spite of protecting group strategy, but no corresponding 2,3-di-O-substitution. This is probably the result of partial silyl migration under the alkaline alkylation conditions.

The quantum mechanics (QM) and quasiclassical trajectory (QCT) calculations have been carried out for the title reaction with the ground minimal allowed rotational state of CH (j = 1) on the 1 1A′ potential energy surface. For the reaction probability at total angular momentum J = 0, a similar trend of the QM and QCT calculations is observed, and the QM results are larger than the latter almost in the whole considered energy range (0.1–1.5 eV). The QCT integral cross sections are larger than the QM results with centrifugal sudden approximation, while smaller than those from QM method including Coriolis coupling for collision energies bigger than 0.25 eV. The quantum wave-packet computations show that the Coriolis coupling effects get more and more pronounced with increasing of J. In addition to the scalar properties, the stereodynamical properties, such as the average rotational alignment factor , the angular distributions P(θr), P(ϕr), P(θr,ϕr), and the polarization-dependent generalized differential cross sections have been explored in detail by QCT approach. © 2013 Wiley Periodicals, Inc.

We theoretically explored the adsorption and diffusion properties of oxygen and several harmful gases penetrating the graphdiyne monolayer. According to our first-principles calculations, the oxidation of the acetylenic bond in graphdiyne needs to surmount an energy barrier of ca. 1.97 eV, implying that graphdiyne remains unaffected under oxygen-rich conditions. In a broad temperature range, graphdiyne with well-defined nanosized pores exhibits a perfect performance for oxygen separation from typical noxious gases, which should be of great potential in medical treatment and industry.

Introduction and Aim: The purpose of this meta-analysis was to evaluate the efficacy of antimuscarinics alone or in combination with alpha-blockers for the treatment of ureteral stent-related symptoms. Methods: The databases MEDLINE, EMBASE, PubMed, the Cochrane Controlled Trial Register of Controlled Trials from 2000 to February 2016 were searched to identify randomized controlled trials that referred to the use of a combination of antimuscarinics and alpha-blockers for the treatment of ureteral stent-related symptoms. A systematic review and meta-analysis was conducted. Results: Seven publications involving 710 patients were included in the meta-analysis. In the analysis, we found significantly improved total International Prostate Symptom Score, quality of life, body pain and work performance score of the Ureteral Stent Symptom Questionnaire (USSQ) in the combination group compared with antimuscarinics alone (p = 0.00001, p = 0.00001, p = 0.00001 and p = 0.004, respectively). Antimuscarinics alone versus the control group showed significant improvement in urinary symptom, body pain and general health score of USSQ (p = 0.002, p = 0.00001 and p = 0.003, respectively). Conclusions: Our meta-analysis shows the beneficial effect of antimuscarinics alone in reducing stent-related symptoms. The combined use of antimuscarinics and alpha-blockers results in additive favorable effects in patients with ureteral stent-related symptoms compared with antimuscarinics monotherapy. The alpha-blockers may enhance the efficacy of the antimuscarinics, which is beneficial for the treatment of ureteral stent-related symptoms.

By numerically solving the time-dependent Schrodinger equation for helium gas in a special two-color laser field, which is synthesized by a long (9 fs) driving pulse and a short (6 fs) controlling pulse, we discuss the influence of the carrier-envelope phase, frequency, and the intensity of the controlling pulse on the generation of harmonic spectra and isolated attosecond pluses. In the cutoff region, two or three plateaus can be controlled by optimizing these laser parameters, and an ultrabroad supercontinuum harmonic spectrum with a bandwidth of 800 eV can be produced, which can support an ultrashort isolated 4.5 as pulse generation by Fourier transformation. Furthermore, using classical ionizing and returning energy maps, time–frequency analyses are presented to explain the underlying physical mechanisms.

The deposition rate of μc-Si films was investigated for four excitation frequencies 30, 40, 60, 70 and 80 MHz with other deposition parameters fixed. Deposition rate increases with the increasing of excitation frequency, while Raman crystallinity behaves more complicated. With the optimization of deposition parameters, p-i-n solar cells at an initial efficiency of 5.41% were fabricated. With the increasing of plasma excitation frequency, the non-uniformity of these thin films increases. To better understand the cause of the non-uniformity of these films, a numerical simulation was carried out. The numerical results generally followed the experimental data. It turned out that the standing waves and the evanescent wave guide modes on the electrode surface played an important role. In order to achieve highly uniform thin films, a triode-electrode was employed together with a pulsed power source. We found that with a proper choice of pulse frequency and DC voltage applied to the mesh, non-uniformity is less than 8% for films deposited on 10×10 cm 2 substrates. Simulations were also applied to analyze the results.

Close formation flight is one of the most complicated problems on multiple Uninhabited Aerial Vehicles (UAVs) coordinated control. This paper proposes a new method to achieve close formation tracking control of multiple UAVs by applying Particle Swarm Optimization (PSO) based Proportional plus Integral (PI) controller. Due to its simple structure and effectiveness, multi-criteria PI control strategy is employed to design the controller for multiple UAVs formation, while PSO is used to optimize the controller parameters on-line. With the inclusion of overshoot, rise time, and system accumulated absolute error in the multi-criteria performance index, the overall performance of multi-criteria PI controller is optimized to be satisfactory. Simulation results show the feasibility and effectiveness of the proposed approach.

Immersion test, electrochemistry test and block-on-cylinder type wear test have been applied to study the corrosion and wear resistance of AZ91D Mg alloy with and without microarc oxidation (MAO) treatment in Hank’s solution. Through MAO, a ceramic coating is directly formed on the surface of AZ91D Mg alloy, by which its corrosion and wear resistances are greatly improved. The immersion test results show the mass loss of untreated AZ91D Mg is 15 times of that of MAO ones after 21 days immersion test. The electrochemical corrosion experiments show that the corrosion potential of Mg alloy is improved from −1.5786 V to −0.43019 V through MAO surface treatment, the corrosion current is reduced from 0.028703 A/cm2 to 2.0456 × 10−7 A/cm2, and the polarization resistance is improved from 1.2753 × 10−5 Ω/cm2 to 0.90886 Ω/cm2. The lubricate sliding wear test results show the mass loss of untreated AZ91D Mg is 1.5 times of that of MAO ones.

Knowledge management is the process of capturing, developing, sharing, and effectively using organizational knowledge. As a business concept, it has been traditionally applied to revenue-producing organizations with the aim of increasing profits and gaining competitive advantages. However, in fact, it can also be applied to non-profit organizations such as libraries. In the knowledge economy era, the traditional management mode of library can no longer satisfy readers’ need and management requirement. A review of related literature in recent years is carried out for demonstrating the need to apply knowledge management to library management, including connotations, targets, contents, patterns and technologies. The article considers that the study of library knowledge management in China have achieved certain results, but still at their early stages. It points out the shortages of the research and presents relevant expectations to show the way in the future of library knowledge management in China. Keywords—Library management; Knowledge management; Library knowledge management; Review

We present a theoretical prediction of a highly efficient membrane for hydrogen purification and natural gas upgrading, i.e. laminar MoS2 material with triangular sulfur-edged nanopores. We calculated from first principles the diffusion barriers of H2 and CO2 across monolayer MoS2 to be, respectively, 0.07 eV and 0.17 eV, which are low enough to warrant their great permeability. The permeance values for H2 and CO2 far exceed the industrially accepted standard. Meanwhile, such a porous MoS2 membrane shows excellent selectivity in terms of H2/CO, H2/N2, H2/CH4, and CO2/CH4 separation (>103, > 103, > 106, and > 104, respectively) at room temperature. We expect that the findings in this work will expedite theoretical or experimental exploration on gas separation membranes based on transition metal dichalcogenides.

We present a theoretical investigation of high-order harmonic generation in spatially inhomogeneous two-color laser fields by solving three dimensional time dependent Schrodinger equation. The cutoff in the harmonic spectra can be significantly extended by means of our proposed method (i.e., from helium interacting with the plasmon-enhanced two-color laser fields), and an ultrabroad supercontinuum up to 1.5 keV is generated by selecting proper carrier-envelope phase of the controlling field. Moreover, classical trajectory extraction, time-dependent ionization and recombination rates, and time-frequency analyses are used to explain the generation of this ultrabroadband supercontinuum. As a result, an isolated 8.8 attosecond pulse can be generated directly by the superposition of the supercontinuum harmonics.

We theoretically demonstrate that N-substitutional doping dramatically reduces the diffusion barrier for oxygen passing through the pores of polyphenylene, leading to a massive enhancement in O2 selectivity over various harmful gases with excellent permeance at appropriate temperatures for O2 across an N-doped polyphenylene in a unit cell.

We theoretically investigate harmonic generation driven by intense midinfrared lasers. A valleylike structure is observed at very low-order harmonics because of a low-energy photoelectron suppression effect. Further, at the beginning of a broad supercontinuum, a convex structure appears that is distributed from the tail in a very narrow energy band in time-frequency maps. Surprisingly, our quantum dynamics calculations demonstrate the beneficial wavelength scaling of the harmonic yield to be ${\ensuremath{\lambda}}^{4.6}$ for He and ${\ensuremath{\lambda}}^{5.1}$ for Ne over selected energy windows. The bandwidth of the harmonic plateau with only a single quantum trajectory contribution can be further extended by adding a controlling laser field, and the harmonic efficiency is found to be significantly enhanced after macroscopic propagation. In addition, ultrashort isolated attosecond pulses can be obtained by properly superposing the harmonics in the plateaus of both the He and Ne systems.

The aim of the study was to explore whether lycopene protects against the activation of human umbilical vein endothelial cells (HUVECs) induced by a proinflammatory stimulus. HUVECs were pretreated with different concentrations of lycopene (1 microm or 10 microm), then incubated with 1 microg/ml LPS for 24 h. After an incubation, the mRNA and protein levels of proinflammatory cytokines (MCP-1, IL-6, VCAM-1), the expression KLF2, TLR4, ERK1/2 and NF-kappaB were assayed. The result showed that lycopene treatment significantly suppressed the response of HUVECs to LPS and reduced the levels of proinflammatory cytokines. Also, lycopene increased KLF2 expression, while it inhibited the activation TLR4 and its downstream ERK and the NF-kappaB signaling pathway in HUVECs.

Heat-induced self-association of regioselectively functionalized 3- O -alkyl celluloses bearing both ethyl- and propyl groups dissolved in water was studied by means of differential scanning calorimetry and oscillatory shear rheology. The measured degrees of substitution were close to 1 but the ratio of ethyl (DS Et ) to propyl groups (DS Pr ) was varied. The aggregation process is intimately coupled with phase separation as shown by the appearance of clouding in the same temperature range. Phase separation is arrested by the incipient gelation; whereby “stronger” gels are produced with high amounts of the propyl substituent than “weaker” phase separating samples as the amount of ethyl groups increases and the amount of propyl groups decreases. The correlation between rheology and thermal analysis clearly demonstrates that aggregation leads to formation of a gel network. It was found that as the ethyl moiety is replaced by propyl group the enthalpies of the thermal transitions increase strongly together with an increase of the elastic modulus ( G ′) and the network is also more coherent with a steady decrease in tan δ ( G ″/ G ′). Reversibility was observed on cooling with a marked hysteresis for samples containing high levels of propyl groups. Hysteresis on cooling was explained in term of additional consolidation of the structure occurring at temperature much higher than the aggregation temperature, possibly involving backbone–backbone interactions. Quantitative analysis of the DSC data, based on the two-state thermodynamic model described by Armstrong et al. (1995) enabled evaluation of the van’t Hoff enthalpy and the aggregation number. On the basis of those thermodynamic parameters, an “intermolecularly bridged clusters” model is proposed for the heat-induced transition of 3- O -ethyl-propyl cellulose ethers. The van’t Hoff enthalpy/calorimetric enthalpy ratio Δ H vH / Δ H cal further indicates on the cooperativity of the process. The number of clusters and indeed the number of molecular chains comprising a cluster are both dependent upon the ratio of the two hydrophobic moieties. An increase in the aggregation number ( n ) (more aggregates coming together) occurs as ethyl is replaced by propyl, consistent with the observation of a “stronger” gel. The effect of the two different moieties on the physico-chemical properties of 3- O -ethyl-propyl cellulose ethers has been explained in term of different size/hydrophobicity of the two moieties and their distribution.

With the rapid expansion of modern multimedia data, accurate and efficient retrieval of audio information has become one of the most important issues that need to be resolved especially in the actual noise environment. As an important part of the multimedia information, audio data provides an indispensable element for the people of auditory perception. However, in the transmission process, it will inevitably be subject to a variety of noise interference. There are generally two kinds of noise, fully distributed type and burst mixed type. In this paper, we mainly focused on noise removal of the latter kind. Combined with commonly used Philips fingerprinting algorithm, noise-removed clean audio clips are used to extract fingerprints and put into the process of retrieval. The results show that our methods can better locate noise, and get a relatively high similarity and matching accuracy.

With the rapid expansion of modern multimedia data, a number of audio fingerprinting algorithms have been proposed. Audio fingerprint is a compact unique content-based digital signature of an audio signal, which can be used to identify unknown audio clips. Due to the interference of different kinds of noise, audio fingerprinting is still a challenging task. In this paper, Nearest Neighbor Estimation (NNE) is used to reduce the interference of the noise. Firstly, audio feature points are extracted from audio clips. Then NNE is used to reduce the impact of noise on the feature points. Experimental results show that NNE reduces the influence of noise effectively in white noise environment.

Close formation flight is one of the most complicated problems on multiple Uninhabited Aerial Vehicles (UAVs) coordinated control. This paper proposes a new method to achieve close formation tracking control of multiple UAVs by applying Particle Swarm Optimization (PSO) based Proportional plus Integral (PI) controller. Due to its simple structure and effectiveness, multi-criteria PI control strategy is employed to design the controller for multiple UAVs formation, while PSO is used to optimize the controller parameters on-line. With the inclusion of overshoot, rise time, and system accumulated absolute error in the multi-criteria performance index, the overall performance of multi-criteria PI controller is optimized to be satisfactory. Simulation results show the feasibility and effectiveness of the proposed approach.

A contusive model of spinal cord injury at spinal segment T8-9 was established in rats. Huantiao (GB30) and Huatuojiaji (Ex-B05) were punctured with needles, and endogenous neural stem cells were labeled with 5-bromo-2'-deoxyuridine (BrdU) and NG2. Double immunofluorescence staining showed that electroacupuncture markedly increased the numbers of BrdU(+)/NG2(+) cells at spinal cord tissue 15 mm away from the injury center in the rostral and caudal directions. The results suggest that electroacupuncture promotes the proliferation of endogenous neural stem cells and oligodendrocytes in rats with spinal cord injury.

In this paper, we present an approach to audio clustering, based on EM Algorithm with Gaussian Mixture. The proposed algorithm is simple and practical; it has an advantage in mass data processing. By improving it, the algorithm can be applied in audio MFCC feature clustering. For further exploration and research, firstly, we make a division of the library into speech and music by Zero-crossing Rate. And then, it is key point to further classify the library of music, such as pop music, rock music, and classical music and so on. In this process, we adopt Gaussian Mixture based on EM Algorithm, using 12-dimensional MFCC (Mel Frequency Cesptral Coefficient) as a feature vector set. The experimental results show that the proposed algorithm can demonstrate that the algorithm increases rate of audio classification compared with the unsupervised study and has good clustering ability.

For audio noise reduction, the current research is mainly focused on the non compressed domain. As for the MP3 (MPEGl-layer3) compressed audio, the common noise reduction method is first fully decoding and then for the decoding audio carrying out noise reduction. This method costs a lot of time for decoding and it inevitably reduces the processing efficiency for compressed audio. In this paper, we present an improved spectral subtraction method based on MDCT-entropy activity detection method for noise estimation in compressed domain. The proposed algorithm works directly on MP3 frames. The experimental results show that the proposed algorithm can remove noise directly from noisy MP3 audio and its process efficiency is higher than common method. And the signal-to-noise ratio (SNR) of the compressed audio is improved obviously.

In the time of digital information, audio data has become an important part in many modern computer applications. Automatic classification based on audio content has been considered as an important way to cope with the problem of audio structuration. In this paper, we present an improved algorithm based on FRNNC (Fuzzy-rough nearest neighbour clustering), which derive from FRNN algorithm and have combined clustering algorithm. In our work, we extract audio features from the MDCT domain and form feature vectors by introduce the concept of feature granularity, and then apply the FRNNC algorithm in audio classification. The experimental results show that our classification method not only greatly reduces the processing time of classification, but also improves the classification accuracy.

The isotopic compositions of boron in Da Qaidam Lake, Quinghai, have been determined by using the technique of thermal ionization mass spectrometry of cesium tetraborate. The brines are enriched in 11B, with an average δ11B of +5.49 ± 2.34%., compared with those of lake sediments and boron minerals produced by the lake. The apparent isotopic fractionation factors between brine and lake sediments as well as boron minerals are 0.988 ± 0.001 and 0.986 ± 0.001, respectively. Source water δ11B values range from −11.72 to + 16.69%., depending on their origin.

Using moment invariants algorithm extract the eigenvector for the characteristics of the human ear. The algorithm is not subject to restrict on translation, rotation and the ratio of changes. Canny algorithm used for edge detection of human ear base on moment invariants. Experiment show that Canny algorithm can not miss the real edge and put the non-edge points as the edge point detection. It detects the edge points as possible in the actual center of the edge and Canny algorithm also inhibit the false edge response.

Natural disasters such as forest fires, earthquakes, tsunamis, floods, hurricanes, and cyclones happen unexpectedly and bring out the worst influence on people. Unmanned Aerial Vehicles (UAVs) could be used under these disasters for surveillance, search and rescue. In order to have good performances in mission areas, effective algorithms are required in mission re-tasking and path re-planning to handle unanticipated events or any environmental disturbances. In this paper, a new algorithm is proposed to deal with path re-planning for multi-mission of multi-UAV under environments with unexpected events. A group of UAVs are considered to perform joint missions. Each UAV plans its own initial, optimal or sub-optimal path using Voronoi graph and Dijkstra algorithm. Our algorithm is then employed to assign a distinct task to each UAV and to re-plan its path based on new multi-mission requirement corresponding to some unexpected events. In addition to a theoretical analysis of the algorithm, the paper has also provided relevant simulation results which have shown that the algorithm can be used effectively for multiple cooperating UAVs’ path re-planning under uncertain and dynamic disaster environments.

In the upper stream of Yellow River, the status of vegetation cover is not as good as other location in the east of China. Considering the huge economic benefit of building hydroelectric stations, people took a lot of measures to structure hydropower stations, including in the upper stream of Yellow River. The objective of this study was to figure out the temporal variation and spatial rules of the vegetation cover based the time-series Moderate Resolution Imaging Spectroradiometer (MODIS) 250m NDVI datasets and Landsat satellites image data in the upper stream of Yellow River. The exact study region is the area along the Yellow River from Liujiaxia hydropower station to Qingtongxia hydropower station (Liu~Qing section). The research adopted the rules of average in-year NDVI changes extracted from MODIS data to modify the NDVI calculated from Landsat satellite images of different months to obtain the spatial heterogeneity and temporal dynamics in vegetation variation. A series of statistical analysis were applied to the NDVI and weather characteristics to identify the relation between them. Compared to the effect of weather factors, the relations between hydroelectric development and vegetation cover changes were analyzed.

Based on density functional theory and the first principles molecular dynamics simulations, a three-dimensional B-doped graphene-interconnected framework has been constructed that shows good thermal stability even after metal loading. The average binding energy of adsorbed Li atoms on the proposed material (2.64 eV) is considerably larger than the cohesive energy per atom of bulk Li metal (1.60 eV). This value is ideal for atomically dispersed Li doping in experiments. From grand canonical Monte Carlo simulations, high hydrogen storage capacities of 5.9 wt% and 52.6 g/L in the Li-decorated material are attained at 298 K and 100 bars.

Thermodynamic model of wet compression process is established in this paper. The topics of ideal wet compression process, actual wet compression process, water droplet evaporative rate, wet compression work, inlet evaporative cooling, concept of wet compression efficiency, aerodynamic breaking of water droplets etc. are investigated and discussed in this paper.Copyright © 2002 by ASME

Theoretical and experimental study of compressor and gas turbine performance with wet compression has been carried out on S1A-02 industrial gas turbine to reveal its effects on gas turbines, compressors. Experiment results show that wet compression has significantly effects on performances of gas turbines and compressors; under situations of high ambient temperature, wet compression can be used to restore engine power output.

A Moore-Greitzer-typed model is established for a compression system with wet compression in this paper, which can reveal effects of wet compression on transients of this compression system when surge or rotating stall occurs. Simulation results show that wet compression affects compressor stable characteristic greatly, as a result post-stall transients of this system will be changed when wet compression is used and what is more interesting is that under some situations wet compression can be used to eliminate surge and rotating stall.Copyright © 2002 by ASME

High-order harmonic generation from the molecular ion H-2(+) exposed to intense laser fields is investigated by the time-dependent quantum wave packet method. Molecular and atomic plateaus of harmonic spectra are effectively distinguished at large internuclear distances, where the harmonic efficiency of the molecular plateau is several orders of magnitude higher than that of the latter. We report on a physical model of the origin of the molecular supercontinua and reveal that the creation of this plateau directly results from the interference of the intramolecular electronic wave packet localized in two potential wells following the laser field. This is our first effort in utilizing the efficient molecular plateau to generate intense isolated attosecond pulses by controlling the dynamics of the nucleus and electrons with a mid-infrared laser. Further, we show that the harmonic plateau is enhanced at the macroscopic level by solving the Maxwell wave equation coupled with the Schrodinger equation.

The quasi-classical trajectory method has been employed to investigate the initial vibrational and rotational effects of the title reaction on an improved ab initio potential energy surface for the 11A′ state. Meanwhile, isotopic effect has also been studied at collision energy of 19 kcal/mol. The product rotational alignment factor 〈P2(j′ • k)〉, angular distributions of P(ϕr), P(θr) and the generalized polarization dependent differential cross-sections have been calculated. The- results show that the reagent vibrational excitation generally strengthens the product alignment perpendicular to the reagent relative velocity vector k and affects the product scattering preference, and the rotational excitation has the same trend from j = 0 to 2 except for the higher excitation of j = 3. Further, the substitution of atom H with D leads to a stronger product alignment while changes some stereodynamical properties subtly.

This paper introduces a newly developed automatic system for reliability test of silicon pressure sensor. This system performs two functions: the dynamic cycling life test and the static parameter calibration of pressure sensors. This system makes it possible that the reliability test be carried through under the integrated stresses of temperature, electricity and dynamic pressure. And the failure pressure cycling times of each test samples can be determined accurately. All the static parameters of pressure sensors can be measured automatically and precisely by this system. Test results of some pressure sensors were presented.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.