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In view of the fact, the poor stability and inadequate chemical properties of conductive polymers inhibit their use in gas sensor applications. Aside from this, the elegant two-dimensional (2D) polymeric graphitic carbon nitride (g-C3N4) have attracted numerous attention for the room temperature (RT) gas sensing applications due to its intrinsic porous structure and the lone pair electrons on nitrogen atoms. Herein, we report surface acoustic wave (SAW) NO2 gas sensor using 2D g-C3N4 nanosheets deposited on langasite (LGS). Further, the thickness effect on gas sensing performances were manifested and it was noticed that 220 nm thickness of g-C3N4 coated LGS SAW sensor showed better sensing performances. The g-C3N4/LGS SAW sensor showed a significant negative differential frequency shift (Δf) of ~3.1 kHz at room temperature (RT~27 oC) for 100 ppm of NO2 gas with a quick response/recovery times (42/22 s). Furthermore, our experimental results demonstrated that the effect of temperature remarkably influences the NO2 sensing responses and it was escalated from ~3.1 kHz to ~23.3 kHz in the temperature range of 27 oC to 200 oC for 100 ppm of NO2. Also, the device showed immense sensitivity towards NO2 (100 ppm) under various relative humidity (RH) conditions (20-80%) at RT. Besides, the g-C3N4/LGS SAW sensor showed a low detection limit (~158 ppb), excellent long-term stability, high sensitivity, and selectivity to NO2 gas, which could be ascribed to the enhancement in mass loading effect resulting by the absorption of NO2 gas molecules. Finally, with help of resistive gas sensors, we have deliberately discussed the underlying mechanism associated with the 2D g-C3N4 nanosheets deposited LGS SAW device.

Although excellent milestones of III-nitrides in optoelectronic devices have been achieved, the focus on the optimization of their geometrical structure for multiple applications is very rare. To address this issue, we exclusively designed a prototype device to enhance the photoconversion efficiency and gas interaction capabilities of GaN nanorods (NRs) grown on a V-grooved Si(100) substrate with Si(111) facets for photodetector and gas sensor applications. Photoluminescence studies have demonstrated an increased surface-to-volume ratio and light trapping for GaN NRs grown on V-grooved Si(111). GaN NRs on V-grooved Si(100) with Si(111) facets exhibited high photodetection performance in terms of photoresponsivity (217 mA/cm2), detectivity (3 × 1013 Jones), and external quantum efficiency (2.73 × 105%) compared to GaN NRs grown on plain Si(111). Owing to the robust interconnection between NRs and a high surface-to-volume ratio, the GaN NRs grown on V-grooved Si(100) with Si(111) facets probed for NO2 detection with the assistance of photonic energy. The photo-assisted sensing makes it possible to detect NO2 gas at the ppb level at room temperature, resulting in significant power reduction. The device showed high selectivity to NO2 against other target gases, such as NO, H2S, H2, NH3, and CO. The device showed excellent long-term stability at room temperature; the humidity effect on the device performance was also examined. The excellent device performance was due to the following: (i) benefited from the V-grooved Si structure, GaN NRs significantly trapped the incident light, which promoted high photocurrent conversion efficiency and (ii) GaN NRs grown on V-grooved Si(100) with Si(111) facets increased the surface-to-volume ratio and thus improved the gas interaction with a better diffusion ratio and high light trapping, which resulted in increased response/recovery times. These results represent an important forward step in prototype devices for multiple applications in materials research.

Background: The corrosion of steel bar leads to the deterioration of structural behaviors, high cost maintenance, shortened service life. The bridge deck structures constructed by Fiber Reinforced Polymer (FRP) bars and High-Volume Fly Ash-Self-Compacting Concrete (HVFA-SCC) can achieve low energy consumption, sustainable construction and high durability. However, the structural behaviors of this bridge deck are still unclear. Objective: The aim of this paper is to study the structural behaviors, including ultimate loads, failure mode, cracking behavior, deflection and strain of one-way HVFA-SCC slabs reinforced with Glass- FRP (GFRP). Experimental: Eleven full-scale HVFA-SCC slabs, varying in reinforcement diameter, reinforcement ratio, shear-span ratio, the type of reinforcing materials and concrete matrix materials, were tested by using a four-point bending load. Methods: The test results of tested specimens were compared with existing theoretical models, such as crack load, ultimate bearing capacity, maximum crack width, maximum crack space and deflection predicted model. Results: The GFRP reinforced HVFA-SCC slab exhibits similar structural behaviors to the GFRP reinforced NC slab. The maximum crack width of HVFA-SCC slab is significantly increased by using GFRP bars with a diameter of 19 mm. Conclusion: It is concluded that it is feasible to use HVFA-SCC instead of NC combined with GFRP bars in bridge deck structures. The stress limit of concrete materials (0.45fc) is the main governing factor for the service limit state (SLS) of GFRP reinforced HVFA-SCC slabs. The maximum crack width of GFRP reinforced HVFA-SCC slabs can be predicted by using EHE-08 and GB 50608-2010 models.

Clayey silt reservoirs bearing natural gas hydrates (NGH) are considered to be the hydrate-bearing reservoirs that boast the highest reserves but tend to be the most difficult to exploit. They are proved to be exploitable by the first NGH production test conducted in the South China Sea in 2017. Based on the understanding of the first production test, the China Geological Survey determined the optimal target NGH reservoirs for production test and conducted a detailed assessment, numerical and experimental simulation, and onshore testing of the reservoirs. After that, it conducted the second offshore NGH production test in 1225 m deep Shenhu Area, South China Sea (also referred to as the second production test) from October 2019 to April 2020. During the second production test, a series of technical challenges of drilling horizontal wells in shallow soft strata in deep sea were met, including wellhead stability, directional drilling of a horizontal well, reservoir stimulation and sand control, and accurate depressurization. As a result, 30 days of continuous gas production was achieved, with a cumulative gas production of 86.14 ×104 m3. Thus, the average daily gas production is 2.87 ×104 m3, which is 5.57 times as much as that obtained in the first production test. Therefore, both the cumulative gas production and the daily gas production were highly improved compared to the first production test. As indicated by the monitoring results of the second production test, there was no anomaly in methane content in the seafloor, seawater, and atmosphere throughout the whole production test. This successful production test further indicates that safe and effective NGH exploitation is feasible in clayey silt NGH reservoirs. The industrialization of hydrates consists of five stages in general, namely theoretical research and simulation experiments, exploratory production test, experimental production test, productive production test, and commercial production. The second production test serves as an important step from the exploratory production test to experimental production test.

Although metal nanoparticles (NPs) have been widely reported, Au NPs functionalized reduced graphene oxide (rGO)/GaN nanorods (NRs) for multi-functional applications are rarely discussed. The rGO is a well known transparent electrode and has been considering an alternative electrode to ITO in the current optoelectronic community. In this work, Au NPs functionalized rGO (Au@rGO)/GaN NRs hybrid structure probed for photodetector and CO gas sensing applications. The hybrid structure was characterized by scanning electron microscopy, transmission electron microscope, current-voltage characteristics, photo conductivity, and gas sensor measurements. The Au@rGO/GaN NRs showed higher photoresponsivity (λ = 382 nm, 516 nm) compared to rGO/GaN NRs at room temperature. The rising and falling times of Au@rGO/GaN NRs are faster than that of rGO/GaN NRs. The hybrid structure Au@rGO/GaN NRs exhibited high CO gas response compared to rGO/GaN NRs at room temperature (∼38% to the 20 ppm). Au NPs played an important role in terms of electronic and chemical changes in the hybrid structure for improving both photodetectors the CO gas response. Such a multi-functional hybrid device is an interest of various room temperature applications.

The surface states, poor carrier life, and other native defects in GaN nanorods (NRs) limit their utilization in high-speed and large-gain ultraviolet (UV) photodetection applications. Making a hybrid structure is one of the finest strategies to overcome such impediments. In this work, a polypyrrole (Ppy)-poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/GaN NRs hybrid structure is introduced for self-powered UV photodetection applications. This hybrid structure yields high photodetection performance, while pristine GaN NRs showed negligible photodetection properties. The ability of the photodetector is further boosted by functionalizing the hybrid structure with Ag nanowires (NWs). The Ag NWs-functionalized hybrid structure exhibited a responsivity of 3.1 × 103 (A/W), detectivity of 3.19 × 1014 Jones, and external quantum efficiency of 1.06 × 106 (%) under a UV illumination of λ = 382 nm. This high photoresponse is due to the huge photon absorption rising from the localized surface plasmonic effect of a Ag NWs network. Also, the Ag NWs significantly improved the rising and falling times, which were noted to be 0.20 and 0.21 s, respectively. The model band diagram was proposed with the assistance of X-ray photoelectron spectroscopy to explore the origin of the superior performance of the Ag NWs-decorated Ppy-PEDOT:PSS/GaN NRs photodetector. The proposed hybrid structure seems to be a promising candidate for the development of high-performance UV photodetectors.

Recently, III-nitride semiconductor nanostructures, especially InGaN/GaN quantum well nanorods (NRs), have been established as a promising material of choice for nanoscale optoelectronics and photoelectrochemical (PEC) water-splitting applications. Due to the large number of surface states, III-nitride NRs suffer from low quantum efficiency. Therefore, control of the surface states is necessary to improve device performance in real-time applications. In this work, we investigated the effect of hydrogen plasma treatment on the optical properties of InGaN/GaN single-quantum-well (SQW) NRs. The low-temperature photoluminescence (PL) studies revealed that yellow and green emissions overlapped and the yellow band is more dominant in the pristine InGaN/GaN SQW NRs. However, the emission corresponding to yellow luminescence was strongly suppressed and the green emission is more intensified in hydrogenated InGaN/GaN SQW NRs. Furthermore, the time-resolved PL spectroscopy studies revealed that the carrier lifetimes of hydrogenated InGaN/GaN SQW NRs are relatively short compared to the pristine InGaN/GaN SQW, indicating the effective reduction of non-radiative centers. From the PEC measurement, the photocurrent density of hydrogenated InGaN/GaN SQW NRs in the H2SO4 solution is found to be 5 mA cm-2 at -0.48 V versus reversible hydrogen electrode, which is 3.5-fold larger than that of pristine ones. These findings shed new light on the significance of surface treatment on the optical properties and thus nanostructured photoelectrodes for PEC applications.

In this work, reduced graphene oxide (rGO)/GaN nanorods (NRs) hybrid structure based sensors for hydrogen (H2) and hydrogen sulfide (H2S) gases has been demonstrated at room temperature. The morphological, elemental, and structural analyses were carried out by using scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. The electrical characterization of rGO/GaN NRs hybrid structures showed good rectifying behavior compared to pristine GaN NRs. The H2 and H2S gas sensing measurements at different gas concentrations revealed that the rGO/GaN NRs exhibit superior sensing properties compared to pristine GaN NRs. In order to find the gas sensing mechanism of rGO/GaN NRs, hybrid structure sensor is also tested with NOx gas. Our experimental results revealed that the rGO/GaN NRs are good candidates for selective detection of H2S gas. The rGO/GaN NRs showed remarkably improved response under ultra-violet (λ = 365 nm) illumination, the photogenerated carriers could be responsible for increasing response of the gas sensor at 30 °C under UV illumination. In addition, humidity test of the rGO/GaN NRs sensor was also conducted in this work. Our experimental results suggested that decorating GaN NRs with solution-processable rGO is one of the effective ways to enhance the response of GaN nanostructures.

Although the physicochemical properties of graphene oxide-Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (GO-PEDOT:PSS) nanocomposite has widely reported, the urgency of this nanocomposite in the surface acoustic wave (SAW) technology still remains at the infancy stage. In this work, a high response SAW NO2 gas sensor was developed by depositing the GO-PEDOT:PSS nanocomposite on piezoelectric LGS substrate. The pristine LGS SAW sensor has showed a resonant center frequency of 136.10 MHz and it was shifted to 135.78 MHz for the GO-PEDOT:PSS coated LGS SAW sensor. The observed shift in resonance frequency likely due to the mass loading effect of GO-PEDOT:PSS nanocomposite interface. However, under the gas ambient the GO-PEDOT:PSS/LGS SAW sensor exhibited a significant negative differential frequency shift (Δf) of 5.89 kHz to100 ppm of NO2 gas with a good cycling stability, excellent sensitivity and a low detection limit (∼175 ppb) at room temperature (RT), while the pristine GO/LGS and PEDOT:PSS/LGS SAW sensors showed the Δf of about 0.9 kHz and 2.1 kHz, respectively. In addition, under the various relative humidity conditions at RT for 100 ppm of NO2, the GO-PEDOT:PSS/LGS SAW device showed a dominant Δf. Our experimental results divulged that the effect of mass loading is the responsible underlying mechanism for the superior NO2 gas sensing performances. In turn, the predominant mechanism between the chemical interface and NO2 gas molecules on GO-PEDOT:PSS/LGS SAW device has been deliberately discussed in detailed by comparing with chemo-resistive type gas sensing properties These intriguing results indicate that the significance of GO-PEDOT:PSS has a synergetic effect in SAW sensor applications.

Although gallium nitride (GaN) nanostructures are auspicious for photocatalytic activity, geometrical optimization has paid much attention for a significant light trapping in photoelectrochemical applications. To minimize the optical losses, we designed a prototype V-groove textured Si (100) with (111) facets, and GaN nanorods (NRs) were grown over a prototype substrate using plasma-assisted molecular beam epitaxy. The photocurrent density of V-groove textured GaN NRs in the NaOH electrolyte is found to be 801.62 μA/cm2 at 1.14 V vs reversible hydrogen electrode, which was 2.1-fold larger than that of GaN NRs on plain Si (111). Using this prototype V-groove textured Si(100) with (111) facets, a significant light can be trapped and modulated into GaN NRs. Furthermore, the heterostructure between GaN NRs and V-groove textured Si stimulates effective charge separation and transportation. These results represent an important forward step in solar photoelectrolysis.

Understanding the metal/semiconductor interface is very significant for real-time optoelectronic device applications. In particular, the presence of interface states and other defects is detrimental to photodetector applications. In this study, the electrical transport properties of a pristine gallium nitride (GaN) nanorod (NR)-based Schottky diode are demonstrated at different temperatures by current–voltage characteristics in the range of 200–360 K. An enhancement in the Schottky barrier height (0.65 eV for hydrogen-passivated GaN NRs compared to 0.56 eV for pristine ones) is noticed. The effect of deep traps residing within the forbidden gap of GaN NRs is investigated using deep-level transient spectroscopy. Two deep defects are found at E C − 0.19 eV and E C − 0.31 eV in pristine GaN NRs; the E C − 0.31 eV defect peak is attributed to V Ga or nitrogen interstitials. After hydrogenation the peak at E C − 0.31 eV is suppressed and that at E C − 0.19 eV remains unchanged. The hydrogenated GaN NRs show a high photoresponse, which is nearly 2.83 times higher than that of pristine GaN NRs. The hydrogenated GaN NRs exhibit a photoresponsivity of 4.7 × 10−3 A W−1 and detectivity of 1.24 × 1010 Jones under UV illumination of λ = 382 nm. The enhanced performance is attributed to the deep defect passivation by hydrogenation along with the surface-state-free interface between the GaN NRs and metal contacts. The experimental results demonstrate the significance of hydrogen treatment use in the fabrication of GaN-based optoelectronic devices.

Transient electromagnetic method (TEM) is a commonly-used geophysical method of measuring the secondary electromagnetic field induced by transient pulse sources. Because of the inherent mutual-induction between TX and RX coils, the measured field always contains the mutual-induction field, which becomes stronger when TX coil becomes smaller and closer to RX coil. It influences the near-surface TEM systems, which utilize small TX coils to effectively resolve the near surface explorations. The mixture of the mutual-induction field with the secondary field at early period leads to a blind region in the shallow surface in TEM exploration. To solve this problem, we applied two concentric and parallel current coils in the TEM system. They are opposing coils, which means that the two coils are physically same, but the currents in them are of equal value and in reverse directions. The RX coil is equidistant to the two opposing coils. By means of this special arrangement, the mutual-induction field received at the RX coil is zero, which means that the mutual induction effect is efficiently eliminated, and pure secondary field of the conductive underground will be measured. It is proved by theory and model calculation that opposing coils transient electromagnetic method has advantages in lateral resolution. It is quite suitable for small coil TEM system aiming at shallow subsurface detection.

The transient electromagnetic (TEM) method is a commonly used, nonintrusive, geophysical method, but inherent mutual induction between the transmitter (TX) and receiver (RX) coils strongly influences the measurements. We have developed an opposing-coils configuration to greatly reduce this effect. Three coils are used in this system. The upper opposing coil is physically the same as the lower TX coil, and they are concentric and parallel to the middle RX coil. A pair of currents with equal amplitudes but reverse directions is injected into the opposing and TX coils. Theoretical calculations in free space show that the received magnetic field by the RX coil is zero, which indicates that the mutual induction effect could be largely reduced. Physical experiments prove that an almost-pure secondary field could be acquired using this system. We have studied an optimal separation between the TX and opposing coils to guarantee that the primary magnetic field is powerful and the instrument is compacted for field work. Then, the efficient exploration depth of this system for typical geoelectric models was simulated to be approximately 15–50 m. Comparisons of simulated responses over highly conductive thick plates in free space and a field test over a culvert structure between this system and EM-47 showed that the system has enhanced sensitivity and lateral resolution. This system can be used in near-surface investigations, e.g., groundwater, environmental, and engineering investigations.

Coupling of graphene and its derivatives with organic moieties is one of the promising strategies to enhance the gas sensing performance. A novel ternary nanocomposite of p-Phenylenediamine-graphene oxide (PGO)/InGaN nanorods (NRs) probed as chemiresistive gas sensor for carbon monoxide (CO) in ppm concentrations. The InGaN NRs were grown by molecular beam epitaxy, and a drop-casting method was employed to decorate the PGO composite on InGaN NRs. The sensor devices consisting of PGO/InGaN NRs with interdigitated electrodes have been fabricated, and their sensing characteristics for CO were studied. PGO composite provided a significant decrease in the electrical resistance of the ternary nanocomposite of PGO/InGaN at the operating temperature (27 °C – 100 °C). The sensor device based on PGO/InGaN NRs exhibited a higher response than the GO/InGaN NRs. The PGO/InGaN NRs device exhibited a maximum sensing response of ∼131 % at a CO concentration of 100 ppm at an operation temperature of 100 °C, which is 2.7 times higher than the GO/InGaN NRs sensor response. Also, the response (∼93.58%) was remarkably improved under UV illumination at room temperature. The combined effect of active cites in GO and the increased electron density at the nitrogen atom in the amine groups of the PGO are responsible for the excellent performance

The Spot-billed Pelican (Pelecanus philippensis) is a lesser-known pelican species that experienced a significant reduction across its geographic range during the mid-late twentieth century as the result of extirpation of many populations in Asia. Through direct examination of museum skins, we verified the species identification of four nineteenth and twentieth century Spot-billed Pelican specimens from China, including a female specimen that is the northernmost verified distribution record in China (Shanghai) collected during the typical breeding season (24 March 1931), and another individual collected just prior to the breeding season is the most recent historical specimen known from China (20 September 1963). These specimens lend support to the idea that at least some Spot-billed Pelicans were residents (and possible breeders) in China during at least part of the twentieth century. These verified specimens can supply biological material to be used in future multidisciplinary studies about the biology of the extirpated Chinese population, and they may inform future efforts toward the successful reintroduction of this species to China and elsewhere within its former geographic range.

We demonstrate the evolution of GaN films on novel langasite (LGS) substrate by plasma-assisted molecular beam epitaxy, and assessed the quality of grown GaN film by comparing the experimental results obtained using LGS, sapphire and silicon (Si) substrates. To study the substrate effect, X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy and photoluminescence (PL) spectra were used to characterize the microstructure and stress states in GaN films. Wet etching of GaN films in KOH solution revealed that the films deposited on GaN/LGS, AlN/sapphire and AlN/Si substrates possess Ga-polarity, while the film deposited on GaN/sapphire possess N-polarity. XRD, Raman and PL analysis demonstrated that a compressive stress exist in the films grown on GaN/LGS, AlN/sapphire, and GaN/sapphire substrates, while a tensile stress appears on AlN/Si substrate. Comparative analysis showed the growth of nearly stress-free GaN films on LGS substrate due to the very small lattice mismatch (~3.2%) and thermal expansion coefficient difference (~7.5%). The results presented here will hopefully provide a new framework for the further development of high performance III-nitride-related devices using GaN/LGS heteroepitaxy.

This paper proposes a clustering sleep scheduling mechanism based on sentinel nodes monitoring for WSN. The mechanism combines the network clustering strategy with the node dormancy strategy, and improves the method of selecting the candidate cluster heads randomly in Energy-Efficient Unequal Clustering (EEUC) algorithm. The conception of sentinel node is introduced based on EEUC, and the neighbor node set of sentinel node will be dormant when the sentinel node’s data change rate is lower than the setting threshold. Simulation results show that this mechanism can effectively balance the energy consumption of the entire network, and significantly extend the network lifetime.

Gallium-nitride (GaN) nanorods (NRs) were selectively grown on patterned Ti/Si(111) substrates by using plasma-assisted molecular beam epitaxy. The effects of the growth temperature and the Ga flux on the optical properties of the GaN NRs were investigated. Both the length and the diameter of the GaN NRs decreased with increasing growth temperature whereas the diameter of the GaN NRs remained constant and the length increased with increasing Ga flux. The photoluminescence spectra of GaN NRs grown under different experimental conditions exhibited emission peaks corresponding to neutral-donor-bound excitons (D O X), donor-acceptor pair (DAP), and yellow luminescence (YL) bands at 3.477, 3.26, and 2.25 eV, respectively. Results demonstrate that the variation in the diameters of the GaN NRs has a greater influence on the defect concentration than the lengths of the NRs.

This paper proposes a reversible data hiding scheme for gray-level images. The scheme exploits the similarity among adjacent pixels and uses the side-match predictors to obtain prediction-error histogram. Then secret bits are embedded by using histogram shifting method. To achieve high capacity, nonary Exploiting Modification Direction (EMD) algorithm and multi-layer embedding mechanism are used when embedding the secret bits. Additionally, we improve the method of preventing overflow and underflow problems which enhances the compression ability of location map. In the extraction process, we use the same predictors to generate the error histogram, then we can extract the secret bits and recover the original cover image. Experimental results show that our algorithm can achieve better performance compared with the previous related algorithms.

In this work, torrefaction of the sewage sludge was investigated the characteristics of torrefied products and the value of as energy resource to improve energy density and to maintain consistent quality of SRF. Torrefaction was performed two important torrefaction operational parameter, temperature(150-230 ) and Ai reaction time(10-60min). As raising the torrefaction temperature at long reaction times, the moisture content of torrefied products was decreased, while the heating value was increased. Moreover, increasing of the torrefaction temperature led to a increase of the content of the carbon up to 60% compare to the initial the sample, and a decrease of the content hydrogen and oxygen. Especially, Average heating value was 4,818 kcal/kg regardless of the reaction time when torrefaction was performed over 210 . In addition, the fuel ration Ai and coal band were improved after torrefaction because the O/C and the H/C ratio were decreased.

Deep level transient spectroscopy has been used to characterize the deep level traps in Ga- and N-polarity GaN films grown by plasma assisted molecular beam epitaxy on Si(111) substrate. The two deep level traps at Ec−Et∼0.21 eV (E1) and Ec−Et∼0.48 eV (E2) have been detected in Ga-polarity GaN. The E1 level commonly observed deep trap related to the nitrogen vacancy in GaN. It is found that, the E2 level exhibits logarithmic capture kinetic behavior and substantially increases its capture cross section from 10−15 to 10−12 cm2 by employing different pulse width ranging from 5 ms to 35 ms. Such behavior of E2 trap with filling pulse length attributes that, the trap is originated from threading dislocations. In case of N-polarity GaN, we observed two deep level traps with activation energies of Ec−Et∼0.53 eV (E3) and Ec−Et∼0.89 eV (E4). The estimated capture cross-sections (σS) for these defects were found to be ∼2.51×10−15 cm2 and ∼5.21×10−16 cm2 respectively. The E3 and E4 are nitrogen antisite point defect and extended defect related to dislocation deep levels, results from growth on N-polarity crystal structure.

A modified two-slit structure is provided to investigate surface plasmon (SP) interference. It’s based on a novel structure, implemented by adding a metal film on the input port of the T-shape slit. The affection of metal film for SP interference is investigated by simulation. Results show that the interference phenomenon can be more obvious with the metal film II than without it. With our structure, the added metal film can enhance transmission energy of SPs and improve interference effect. The results will give a theoretical guidance for development of nano-scale photonics devices.

We demonstrated the coupling of localized surface plasmons and surface plasmon polaritons modes in a system composed of a metallic particle chain separated from a thin metallic film. The results showed that: (1) the thickness of the metallic particles buried in the dielectric space, (2) the positions of the particles influence the level of interaction between localized surface plasmons and surface plasmon polaritons modes. Meanwhile, the positions of the particles and the thickness of the metallic particles control the electromagnetic enhancement and influence the electric field distributions in this system. This kind of system has a very promising candidate for biosensing and surface enhanced spectroscopy applications.

Thin metallic nanowires and stripes are highly promising candidates for plasmonic waveguides in photonic and electronic devices. We observed light from one end of a gold stripe, following excitation of plasmons at the other end of the stripe, with almost no light emitted along the direction of the stripe, and compared the propagation capacity of different size of stripes. We measured how the polarization of the incident light affected the emitted light intensity through changing the polarization of the incident light. The stripes were synthesized by lithographic fabrication technology. The results will be important for the development of photonic or electronic devices and systems.

Gallbladder cancer is a rare disease and it is associated with a poor clinical outcome and survival. A standard therapy for it has not been established yet. The aim of this study is to evaluate efficacy and safety of two modified ECF regimens in advanced gallbladder cancer patients. Clinical data of 38 patients with advanced gallbladder cancer treated with modified ECF regimen were reviewed retrospectively. Of them, 21 patients received an epirubicin, cisplatin, and 5-FU/LV combination therapy. Seventeen patients received a chemotherapy of epirubicin, cisplatin, and capecitabine. Partial response was achieved in fourteen (36.84%) patients with a median duration of 5 months (range, 3-13 months), while stable disease was achieved in eight patients (21.05%). The median time to progression was 4.0 months (95% CI, 3.62-4.58 months). And the median overall survival was 9.8 months (95% CI, 7.26-12.34 months). Responders demonstrated better survival than non-responders (median survival time: 16 vs. 6.9 months, P = 0.008). The median survival time for epirubicin-, cisplatin- and capecitabine-treated patients was 9.2 versus 8.9 months for epirubicin-, cisplatin- and 5-FU/LV-treated patients. There was no statistical difference between both treatment groups in terms of survival time (P = 0.769). Regimen-related toxicity resulted in at least one treatment delay or dosage reduction in 63.2 and 34.2% patients, respectively. There were no chemotherapy-related deaths during the study. Modified ECF regimen with epirubicin, cisplatin and 5-FU/LV or substituting capecitabine for 5-FU/LV is still a potentially effective therapeutic chemotherapy for patients with advanced gallbladder cancer, and toxicity was manageable. There was no remarkable difference in efficacy between the two regimens.

The strain-relief and structural properties of GaSb films with thin AlSb islands and thick AlSb buffer layers grown on GaAs (0 0 1) substrate at low temperature (LT) by molecular beam epitaxy are investigated by atomic force microscopy and transmission electron microscopy. The strain arising from depositing the buffer layer onto the GaAs substrate was relieved by a periodic array of the 90° misfit dislocations with the Burgers vector of 1/2a 〈1 1 0〉 for the thin AlSb islands buffer, but by both 60° and 90° misfit dislocations for the thick rough-and-flat AlSb buffer. The 90°-misfit dislocation array of AlSb/GaAs interface had an average spacing of 4.80 nm. The mean roughness of the GaSb film on the thin AlSb islands buffer layer was found to be less than 1 nm. These results clearly demonstrate that the presence of a thin, LT AlSb islands initiation layer is very useful for improving the quality of GaSb crystals grown on GaAs substrates.

// Bingchang Zhang 1 , Fen Wang 1 , Lianzhi Dai 1 , Heguo Cai 2 , Yanyan Zhan 1 , Song Gang 1 , Tianhui Hu 1 , Chun Xia 2 , Bing Zhang 1 1 School of Medicine, Xiamen University, Fujian, 361102, China 2 Zhongshan Hospital, Xiamen University, Fujian, 361004, China Correspondence to: Chun Xia, e-mail: chunxia@xmu.edu.cn Bing Zhang, e-mail: cristal66@xmu.edu.cn Keywords: PLCγ1, ShRNA, tumor growth, tumor metastasis, human gastric adenocarcinoma cells Received: September 09, 2015 Accepted: January 01, 2016 Published: January 22, 2016 ABSTRACT Targeted molecular therapy has gradually been a potential solution in cancer therapy. Other authors’ and our previous studies have demonstrated that phosphoinositide-specific phospholipase γ (PLCγ) is involved in regulating tumor growth and metastasis. However, the molecular mechanism underlying PLCγ-dependent tumor growth and metastasis of gastric adenocarcinoma and whether PLCγ may be a potential target for tumor therapy in human gastric adenocarcinoma are not yet well determined. Here, we investigated the role of PLCγ inhibition in tumor growth and metastasis of human gastric adenocarcinoma using BGC-823 cell line and a nude mouse tumor xenograft model. The results manifested that the depletion of PLCγ1 by the transduction with lentivirus-mediated PLCγ1 gene short-hairpin RNA (shRNA) vector led to the decrease of tumor growth and metastasis of human gastric adenocarcinoma in vitro and in vivo . Furthermore, the Akt/Bad, Akt/S6, and ERK/Bad signal axes were involved in PLCγ1-mediated tumor growth and metastasis of human gastric adenocarcinoma. Therefore, the abrogation of PLCγ1 signaling by shRNA could efficaciously suppress human gastric adenocarcinoma tumor growth and metastasis, with important implication for validating PLCγ1 as a potential target for human gastric adenocarcinoma.

We investigate the width, spacing, and number dependencies of an Al+-implanted field limiting ring (FLR) and the influence of an Al+-implanted internal ring on the breakdown voltage characteristics of a silicon carbide (SiC) Schottky barrier diode (SBD). SiC-SBDs having an Al+-implanted guard ring-assisted FLR surrounding a Schottky contact edge and an internal ring inside a Schottky contact were fabricated via ion implantation, annealing, photolithography, and metal lift-off techniques. The breakdown voltage characteristics of the SiC-SBD are enhanced by incorporation of the guard ring-assisted FLR at the Schottky contact edge and the internal ring at Schottky contact region. The breakdown voltage characteristics of the guard ring-assisted FLR SiC-SBDs with an internal ring are significantly dependent on the width, spacing, and number of FLRs. The breakdown voltage is improved as either the FLR width and FLR number increase or the FLR spacing decreases. 1650 V maximal breakdown voltage, corresponding to 82% ideal breakdown voltage, is observed with seven FLRs having 5 µm width and 1 µm spacing. The results indicate that a greater number of FLRs, as well as increased FLR width and decreased spacing can effectively suppress electric field crowding at the periphery of the Schottky contact edge, resulting in higher breakdown voltage. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The dependence of the size and the strain in the double-stacked InAs/GaAs quantum dot (QD) was investigated by using the reflection high-energy electron diffraction pattern, transmission election microscopy (TEM), high-resolution X-ray diffraction (HRXRD), and photoluminescence (PL) measurements. The results of the TEM images and the reciprocal spacer mapping, obtained from the HRXRD measurements, showed that the microstructures of the InAs QDs were significantly affected by the strain-controlled InAs layer thickness, and the PL spectra showed that the peak intensity and position corresponding to the interband transitions from the ground electronic subband to the ground heavy-hole band of the InAs QDs strongly depended on the thickness of the InAs layer embedded in the GaAs barrier. The present results can help improve the precise control of the size and the density in the InAs/GaAs multiple-stacked QD arrays.

In order to improve GaN-based light-emitting diode (LED) performance, a sapphire-etched vertical-electrode nitride semiconductor (SEVENS) LED is fabricated by a chemical wet etching technique. The light-output power, heat dissipation, and reverse electrostatic discharge (ESD) characteristics of SEVENS-LED are improved compared to those of the conventional NiAu lateral-electrode (LE) GaN-based LED formed on the sapphire substrate. The 20 mA light-output power and reverse ESD pulse amplitude of SEVENS-LED are approximately 4.5 mW and 2000 V, respectively. The improved LED performance is attributed to changing a lateral electrode to a vertical electrode although the sapphire substrate is not transferred to a conducting substrate. The device fabrication method will be useful for providing us high-brightness and high-power GaN-based LEDs for future solid-state general lighting applications. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Reflection high-energy electron diffraction (RHEED) and atomic force microscopy (AFM) measurements were used to investigate the dependences of the formation process and the strain on the As/In ratio and the substrate temperature of InAs quantum dots (QDs) grown on GaAs substrates by using molecular beam epitaxy. The thickness of the InAs wetting layer and the shape and the size of the InAs QDs were significantly affected by the As/In ratio and the substrate temperature. The strains in the InAs layer and the GaAs substrate were studied by using RHEED patterns. The magnitude in strain of the InAs QDs formed at a low substrate temperature was larger than that in InAs QDs grown at high substrate temperature. The present results can help to improve the understanding of the formation process and the strain effect in InAs QDs.

We investigated the Si-doped InAs quantum dots (QDs) grown by molecular beam epitaxy and the annealing effects on the QD size distribution through photoluminescence (PL) spectroscopy. A double-peak feature in PL was observed from as-grown InAs QDs with Si-doping, and excitation intensity dependence of PL indicated that the double-peak feature is related to the ground-state emission from InAs QDs with bimodal size distribution. The PL spectrum from Si-doped InAs QDs subjected to annealing treatment at 800°C in nitrogen ambient showed three additional PL peaks and blue-shift of the double-peak feature observed from as-grown sample. The excitation-intensity-dependent PL and consideration of thermal stability of carriers through temperature-dependent PL measurement demonstrated that three additional peaks come from the InAs QDs with three new branches of QD occurring during annealing process.

A multi-objective hybrid genetic based optimization algorithm is proposed according to the multi-objective character of inverse planning. It is based on hybrid adaptive genetic algorithm, which combines the simulated annealing, uses adaptive crossover and mutation, and adopts niched tournament selection. The result of the test calculation demonstrates that excellent converge speed can be achieved using this approach. Key words- Inverse Planning Multi-objective optimization Genetic algorithm Hybrid.

We report on the light emitting of InN/InGaN/GaN dot-in-a-nanorods heterostructure grown on Si(111) substrates using plasma-assisted molecular beam epitaxy. Sharp and isolated single exciton emission line in the near infrared spectral range was observed.

In this paper a high efficient dual path power amplifier (PA) for the code division multiple access (CDMA) handset applications is proposed. A dual path PA consists of two different size Pas combined parallel with single input/output matching circuits. The dual path PA is fabricated in the InGaP/GaAs heterojunction bipolar transistor (HBT) monolithic micro-wave integrated circuit (MMIC) in the CDMA cellular, 824–849 MHz and operates at a supply voltage of 3.4 V. The dual path PA exhibits an output power of 31 dBm, a 36 % power added efficiency (PAE) at an output power, and a −46 dBc adjacent channel power ratio (ACPR) at an 885 kHz offset frequency in the high power mode and an output power of 21 dBm, a 14.2 % PAE at a 16 dBm output level, and a −49 dBc ACPR at a 885 kHz offset frequency in the low power mode. This concept is also available for the other CDMA/OFDM specifications.

The Government of China is planning a new economic-development area, located at Meizhou Bay on the Chinese mainland, opposite the island of Taiwan. Aspects of this development plant will be subject to an assessment of the potential environmental effects. Especially important considerations are changes in land use associated with urbanization and industrial developments, and any activities that could degrade air and water quality, with potential risks for human health, aquaculture, agriculture, and wildlife. During 1988 to 1990, we conducted studies related to meteorology, environmental geology and engineering, physical oceanography, and marine chemistry and biology.

The structural and optical properties of height-controlled InAs quantum dots (QDs) have been investigated by transmission electron microscopy (TEM) and photoluminescence (PL). By depositing 1.4 nm In0.15Ga0.85As and a 1 monolayer (ML) InAs layer with different periods on 3 ML InAs QDs, the height of InAs QDs was systematically controlled with similar lateral size. In TEM images, the indication of dislocations due to the large strain, which can be easily seen in large QDs, is not observed even for the QD sample with the highest aspect ratio (height/width). The PL peak position is shifted toward the longer wavelength with an increase in the aspect ratio of QDs. As the aspect ratio is increased, the full width at half maximum in PL measured at 10 K is decreased from 71 to 34 meV indicating that the inhomogeneous broadening caused by the fluctuation in QD size, especially the height, is significantly reduced.

Gamut extension algorithm which maps from the standard gamut to the device gamut is applied in wide-gamut displays to avoid color distortion and exert display advantage. A gamut extension method based on RGB space is proposed. The algorithm first transforms the standard RGB value to device RGB value, and then extends the gamut with saturation ratio of gamut boundaries and a nonlinear function which reduces the over-painted problem. Gamut extension experiments on sampling points and images are carried out, and the average hue difference is 0.053, and the CCI increase is 22.6%.

Nowadays, drastically reduced resources and unreasonable resource utilization has resulted in the intensification of the contradiction between supply and demand. Based on relevant studies, this study investigates the relationship between resource utilization patterns and the livelihood of the rural peasants. This study employs AHP to fix the weight and tries to construct a coupling model of the two. The model is then employed to analyse the example: Wuzhufeng village. The results show that it is on a low degree coupling stage between resource utilization patterns and rural resident livelihood. The trend of same direction of the two is not obvious. According to an analysis of the reasons, four countermeasures have been put forward. The coupling model was used to analyse the coupling relationship in Wuzhufeng village and verified that the model is effective and feasible in the evaluating process. The model provides a good platform for future research.

The previous models or methods almost adopted static measure, and filters need be updated and maintained frequently, so they can not adapt to dynamic spam and lack of self-adaptation. In this paper, An Immunological approach to filtering junk Email has been built. The experiment shows that this model can efficiently raise both the recall ratio and precision ratio, and enhance the ability of self-adaptation and diversity for the junk Email.

International audience; A wide range of applications in computer intelligence and computer graphics require computing geodesics accurately and efficiently. The fast marching method (FMM) is widely used to solve this problem, of which the complexity is OðN logNÞ, where N is the total number of nodes on the manifold. A fast sweeping method (FSM) is proposed and applied on arbitrary triangular manifolds of which the complexity is reduced to OðNÞ. By traversing the undigraph, four orderings are built to produce two groups of interfering waves, which cover all directions of characteristics. The correctness of this method is proved by analyzing the coverage of characteristics. The convergence and error estimation are also presented.